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Title: Identification and use
of inhibitors of hair growth
United States Patent: 7,468,246
Issued: December 23, 2008
Inventors: Boehm; Thomas (Vorstetten,
DE), Schlake; Thomas (Gundelfingen, DE)
Assignee: Max-Planck-Gesellschaft
zur Forderung der Wissenschaften e.V. (Berlin, DE)
Appl. No.:
10/469,821
Filed: March 6, 2002
PCT Filed: March 06, 2002
PCT No.: PCT/EP02/02470
371(c)(1),(2),(4) Date: April
26, 2004
PCT Pub. No.: WO02/070743
PCT Pub. Date: September
12, 2002
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Pharm Bus Intell
& Healthcare Studies
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Abstract
The invention relates to a method for the
identification and/or production of an inhibitor of hair production.
Moreover, the invention relates to a method for the inhibition of hair
production. The invention also relates to a method for the production of a
pharmaceutical composition. Furthermore, the invention relates to a
pharmaceutical composition comprising an inhibitor of hair production
identified or obtained according to one of the methods of the invention or
a polynucleotide coding for the inhibitor, optionally in a
pharmaceutically acceptable form of administration. The invention also
relates to a pharmaceutical composition which comprises a polypeptide
comprising the DNA-binding domain but not the transactivator domain of Whn,
LEF-1 or Hoxc13, or a polynucleotide coding for said polypeptide,
optionally in a pharmaceutically acceptable form of administration.
Moreover, the invention relates to the use of a polypeptide comprising the
DNA-binding domain but not the transactivator domain of Whn, LEF-1 or
Hoxc13, or a polynucleotide coding for said polypeptide, of an inhibitor
identified or obtained according to one of the methods of the invention or
of a polynucleotide coding for such an inhibitor for the production of a
pharmaceutical composition for the treatment of hair growth disorders. Not
least, the invention relates to a kit for carrying out the methods of the
invention.
Description of the
Invention
REFERENCE TO SEQUENCE LISTING SUBMITTED
VIA EFS-WEB
The entire content of the following electronic submission of the sequence
listing via the USPTO EFS-WEB server, as authorized and set forth in MPEP
.sctn.1730 II.B.2(a)(C), is incorporated herein by reference in its
entirety for all purposes. The sequence listing is identified on the
electronically filed text file as follows
-- see Original Patent.
The invention relates to a method for the
identification and/or production of an inhibitor of hair production
(growth). Moreover, the invention relates to a method for the inhibition
of hair production. The invention also relates to a method for the
production of a pharmaceutical composition. Furthermore, the invention
relates to a pharmaceutical composition comprising an inhibitor of hair
production identified or obtained according to one of the methods of the
invention or a polynucleotide coding for the inhibitor, optionally in a
pharmaceutically acceptable form of administration. The invention also
relates to a pharmaceutical composition which comprises a polypeptide
comprising the DNA-binding domain but not the transactivator domain of Whn,
LEF-1 or Hoxc13, or a polynucleotide coding for said polypeptide,
optionally in a pharmaceutically acceptable form of administration.
Moreover, the invention relates to the use of a polypeptide comprising the
DNA-binding domain but not the transactivator domain of Whn, LEF-1 or
Hoxc13, or a polynucleotide coding for said polypeptide, of an inhibitor
identified or obtained according to one of the methods of the invention or
of a polynucleotide coding for such an inhibitor for the production of a
pharmaceutical composition for the treatment of hair growth disorders. Not
least, the invention relates to a kit for carrying out the methods of the
invention.
A lot of people, in particular women, suffer from the problem of unwanted
hair growth. This hair growth can be caused by disorders, e.g. as a
consequence of various hormone disorders, as a consequence of the aging
process or due to disposition. The most well-known form of hair removal is
shaving which removes the hair on the skin surface. A further method is
the electrocoagulation of the hair follicles; this method is costly and
often accompanied by the irritating formation of scars. Other methods aim
at a disintegration of the hair structure triggered by specific chemical
substances, e.g. eflornithine as inhibitor of ornithine decarboxylase. So
far, there has been no method for depilation interfering with the
formation of hair per se.
Thus, the technical problem underlying the invention is to provide
preparations and steps for the control of hair production, in particular
for the inhibition thereof.
This technical problem is solved by the embodiments characterised in the
claims. Therefore, the invention relates to a method for the
identification and/or production of an inhibitor of hair production,
wherein the method comprises the steps of (a) contacting a cell comprising
at least one factor stimulating hair production as well as a reporter gene
which is operatively linked with the expression control sequence of a
target gene of the factor, with a presumed inhibitor in a medium suitable
for the detection of the reporter gene; (b) quantitative determination of
the reporter gene activation in the cell; (c) quantitative determination
of the reporter gene activation in a cell as defined in (a), without the
cell having been contacted with a presumed inhibitor; and (d) comparing
the reporter gene activation quantitatively determined from (b) and (c),
wherein a reduction or a lack of detectable reporter gene activation in
(b) in comparison to (c) presents an indication for an inhibitor.
The term "inhibitor" comprises all the substances or mixtures of
substances capable of inhibiting hair production. Examples of these
substances or mixtures of substances are proteins, nucleic acids coding
for these proteins or chemicals. Particularly important potential
inhibitors of hair production are proteins, regions of proteins, protein
variants or nucleic acids coding therefore, which are further described
below as preferred embodiments. In the context of the invention,
inhibition relates to a significant reduction of the reporter gene
activation in the methods of the invention. In this context, the
significance can take place by statistical methods known in the state of
the art, such as e.g. the student's T-test, the .gamma..sup.2-test or the
U-test according to Mann-Whitney. Application criteria for the statistical
methods for each individual case are known to the person skilled in the
art. Moreover, adjustments of the statistical methods can be carried out
by the person skilled in the art with common input. Preferably, the
contacting of cells with the potential inhibitor at least leads to an
inhibition of the reporter gene activation, as described in the Example
and Table 1.
The term "contacting" comprises all the kinds of physical or chemical
interactions between the inhibitor molecules and the cell or the cellular
components. For the contacting, the inhibitor can be present in a liquid,
e.g. a nutrient medium for the cell, in solution, wherein the nutrient
medium is then contacted with the cell, e.g. by incubation of the cell in
the medium. Instead of a liquid, gels and gel-like liquids comprising the
inhibitor can be used, too. However, the term "contacting" also comprises
the insertion of the inhibitor into the cell so that there the inhibitor
can interact with the intracellular components like the cellular proteins.
The insertion of the inhibitor can be carried out depending on its
biochemical nature by various methods known in the art. In this
connection, it goes without saying that the methods for the insertion of
nucleic acids and the methods for the insertion of proteins or chemicals
can differ. Examples of such methods suitable for the insertion of nucleic
acids are precipitation transfection such as e.g. Ca-phosphate or RbCl
precipitation transfection, transfection by means of liposomes,
transfection by means of macromolecular polymers, e.g. fullerens,
electroporation methods or transfection by retroviruses or recombination
techniques for the integration into the cellular genome. Depending on the
method, it might be necessary to link the nucleic acids with other nucleic
acid molecules. Examples thereof are plasmids containing the nucleic acid
molecules or retroviral genomes in which the nucleic acids have been
integrated. After the insertion into the cell, nucleic acid molecules can
also be integrated into the cellular genome.
Examples of methods for the insertion of proteins also comprise the
insertion by means of liposomes, the insertion by means of macromolecular
polymers such as e.g. fullerens. Some proteins, however, are actively
absorbed by the cell by import. In this context, it is also possible to
link proteins which would not be absorbed normally, with additional
peptide sequences which are capable of mediating the import of said
proteins.
Depending on their chemical or biochemical characteristics, chemicals are
either imported actively by the cell and are thus inserted into the cell
or they get into the cell by diffusion. Furthermore, chemicals can be
inserted into the cell by means of different methods known in the state of
the art. These methods comprise liposomes, macromolecular polymers.
The term "hair production" relates to the whole biological process leading
to the morphological production of hair. The term further comprises
different steps relevant to hair production individually. These include
the formation of precursor cells of the karatinocytes and mesenchymal
cells which play a role during hair production, their differentiation to
mature karatinocytes, their interaction and the morphological formation of
hair itself. The formation of so-called stem cells is also part of the
biological process underlying the production of hair in the context of the
invention. Apart from new production of hair, the term "hair production"
also comprises the growth of existing hair and the underlying
physiological processes thereby.
In the present invention, the term "factor" relates to proteins
participating in the regulation of hair production, i.e. one or more steps
of the biological process mentioned above. Proteins of this kind comprise
proteins regulating the transcription, translation and/or
post-translational modification of proteins or the genes coding therefore,
which directly play a part in the production of hair. Proteins directly
playing a part in the production of hair are proteins such as, for
example, the hair keratins which are responsible for the molecular
structure of the hair or the molecular phenotype of the cells
participating in the production of hair. Examples of proteins regulating
the transcription of the genes for proteins that play a role in the
production of hair, are transcription factors which activate or enhance
the gene expression of hair keratine. The term "factor" also comprises
proteins capable of moldulating the activity or gene expression of the
proteins acting in a regulatory manner. This includes both proteins
activating or enhancing the activity of the regulatory proteins mentioned
earlier and activating or enhancing their gene expression. Since
regulatory proteins also includes proteins inhibiting the proteins
directly playing a role in the production of hair or weakening their
activity, the term "factor" also comprises proteins inhibiting or
weakening the activity of regulatory proteins acting in an inhibiting
manner and, thus, in the end stimulating the production of hair. Proteins
acting in a regulatory manner can be divided into different classes, e.g.
extracellular proteins, their cellular receptors, intracellular signal
transmitters as well as proteins modifying the activity of the signal
transmitters and transcription factors and their co-factors which regulate
the expression of the proteins directly playing a part in the production
of hair and which are regulated by the proteins mentioned earlier. In many
cases, the members of these classes are connected in so-called signal
transfer cascades in sequence. These signal transfer cascades particularly
serve the purpose of intracellularly interpreting a signal mediated by a
extracellular protein so that the cell can react to it in form of a
changed gene expression. The mediation of such extracellular signals by
means of signal transfer cascades consisting of proteins mentioned earlier
forms the basis of intercellular communication which is of essential
significance during the production of hair.
As to structure, the proteins comprised by the term "factor" have in
common that they have a modular structure. This structure results from the
function of these proteins which have to physically interact with either
different proteins or, in the case of the transcription factors, with
other proteins and the cis-regulatory DNA sequences. A modular structure
means that the factors according to the invention have several domains
which lie either within a single protein or within a protein built from
different subunits. These domains are defined amino acid sequence segments
forming a specific tertiary structure in the area of this domain. These
domains can then be related to a very specific biological function such as
e.g. the recognition of a specific cis-regulatory DNA element or the
specific activation or inhibition of a further protein by physical
interaction. According to the invention, the factors have to comprise
several domains in order to be able to fulfil their biological function.
According to the invention, the factors can be inserted into the cell by
means of different methods described in the art either as nucleic acids or
proteins, as also described for the contacting with the inhibitors.
However, according to the invention, the factors can also be present in
the cell endogenously. In some cases, however, it might nevertheless be
necessary to increase the concentration of the factors or the factor by
exogenous addition. In any case, the factor should be present in the cell
at a concentration and/or conformation which allows the activation of the
reporter gene mediated by the expression control sequence.
The term "reporter gene" comprises genes which, due to their biochemical
or physiochemical properties, can easily be detected directly or by means
of suitable devices or methods. Particularly suitable reporter genes are
described as preferred embodiments of the method of the invention in the
following.
The term "expression control sequence" comprises each of the cis-regulatory
elements necessary for the expression of a gene. Cis-regulatory elements
are DNA sequences with regulatory properties. These include promoter,
enhancer and silencer elements. Promoter elements mediate the basal
expression of a gene, whereas enhancer elements achieve an enhancement of
the expression, silencer elements a reduction or inhibition of the
expression. The promoter, enhancer and silencer elements interact
physically with regulatory proteins, the transcription factors.
Transcription factors can influence the gene expression in different ways.
Some transcription factors, the so-called basal transcription factors bind
to DNA elements such as the TATA box or other so-called "initiator"
elements, e.g. to neighbouring sequence segments. The basal transcription
factors form a complex which, in the end, also recruits the RNA
polymerase, a DNA-dependent enzyme which synthesises RNA and which
mediates the actual transcription. Transcription factors binding to
enhancer elements ensure the fast formation of a stable complex of the
basal transcription factors, for example, by recruiting the basal
transcription factors directly or indirectly via further proteins, the
so-called co-factors, and stabilising the complex initiated in that way.
Transcription factors binding to silencer elements, however, interfere
with the formation of a complex of the basal transcription factors in a
negative manner. A plurality of transcription factors, however, change
only the structure of the DNA and, for that reason, bring closer together
cis-regulatory sequences which normally have a far distance between them
so that transcription factors binding thereto can interact with each other
physically. It is clear that such cis-regulatory elements or the
transcription factors binding thereto can also influence the gene
expression as enhancer or silencer elements. On the one hand, the presence
and the architecture of enhancer and silencer elements in a gene locus, on
the other hand, the tissue-specific expression of the transcription
factors binding to these cis-regulatory elements are responsible for the
tissue-specific expression of a gene.
Within the meaning of the invention, the term "expression control
sequence" relates to a DNA sequence comprising different cis-regulatory
elements described earlier which suffice to mediate the expression of the
reporter gene linked with this expression control sequence and which
normally play a part in vivo in the mediation of the tissue specificity of
the gene expression.
The term "target gene" comprises genes which are regulated by the factors
of the invention in a direct or indirect manner. Factors directly
regulating a target gene according to the invention are the transcription
factors already mentioned earlier, whereas proteins from a regulatory
signal transfer cascade, as described earlier, regulate a target gene in
an indirect manner. The target genes are genes coding for proteins which
either are necessary for the morphological production of hair directly or
are characteristic for the molecular phenotype of a cell type essential
for the production of hair.
The term "quantitative determination" relates to the determination of the
whole reporter gene activation or a quantitatively significant, detectable
part thereof. The determination of the reporter gene activation can take
place either by quantitative detection of the transcripts of the reporter
gene or by quantitative detection of the protein encoded by the reporter
gene. Suitable methods for the quantitative detection of the transcripts
of the reporter gene are known in the state of the art. These include,
amongst others, affinity chromatography methods, mass spectroscopic
methods, nucleic acid hybridisation methods, such as e.g. Northern
analyses or RNase protection experiments, nuclear run-on experiments, PCR
methods suitable for quantifying, such as e.g. normalised PCR,
light-cycling PCR. Suitable methods for the detection of the protein
encoded by the reporter gene comprise methods known in the state of the
art, e.g. detection methods based on specific antibodies, like Western
analyses, ELISA or RIA tests, but also methods wherein the protein is
detected by the detection of its biochemical properties. Such methods can
be carried out as described in the Examples. In this context, for example,
enzymatic activities or chemoluminescence, bioluminescence or fluorescence
can be detected. For the quantitative determination according to the
invention devices are preferably used which allow the quantitative
analysis of the signal produced during detection, e.g. the emission of
photons with chemoluminescence or bioluminescence. Such devices and their
individual application areas are known in the state of the art.
Depending on the detection method used, prior treatment of the cells can
be necessary. Such treatment could, for example, serve the extraction of
the reporter gene transcripts or the proteins from the cell. Such
treatment methods are also known in the state of the art and described in
detail, for example, in Sambrook et al., Molecular Cloning A Laboratory
Manual, Cold Spring Harbor Laboratory (1989), N.Y.
For the method according to the invention to be carried out efficiently,
it might be necessary that the person skilled in the art has to adjust the
detection and treatment methods described in the state of the art which
were referred to earlier to the conditions of the methods according to the
invention. Such adjustments, however, can be carried out by the person
skilled in the art relevant herein with normal efforts.
The term "comparing" means that a relative measure for the reporter gene
activation is established. For this purpose, the reporter gene activation
which was determined after carrying out the steps (a) and (b) mentioned
above is compared to the reporter gene activation into in a cell which was
not contacted with the presumed inhibitor, as described in step (c). A
reduced or even missing reporter gene activation compared to the cell from
step (c) which was not contacted with the inhibitor is an indication for
the fact that the tested potential inhibitor is an inhibitor of hair
production indeed. Within the meaning of the invention, in this context,
the reduction of the reporter gene activation in an inhibitor has to be
significant, as already described above. Preferably, the analysis of the
reporter gene activation determined quantitatively, which comprises the
comparison, can also be supported by suitable devices for electronic data
processing, such as e.g. computer. Thus, a plurality of presumed
inhibitors can be analysed in sequence or at the same time and the data
sets obtained can be analysed effectively.
By means of the methods according to the invention, it is now possible to
identify suitable agents like the inhibitors described earlier and, thus,
to influence the control of the production of hair. A further advantage of
the methods according to the invention is the fact that thereby depending
on the choice of the target gene, specific steps of the process of the
production of hair could be analysed purposefully and could be manipulated
by the inhibitors found. The knowledge obtained in this way allows for the
development of effective therapies of hair growth disorders and can be
applied in prophylaxis and medicine on a wide scope.
A method according to the invention is preferred, wherein the reporter
gene is selected from the group consisting of: .beta.-galactosidase,
luciferase, Renilla luciferase, green-fluorescent protein (GFP),
blue-fluorescent protein (BFP), yellow-fluorescent protein (YFP),
chloramphenicol transferase.
All the reporter genes mentioned above are very well suited for the
quantitative determination by means of the activity of the proteins
encoded by said reporter genes; however, it is, of course, also possible
to detect the RNA transcripts. In this context, .beta.-galactosidase,
luciferase, Renilla luciferase and chloramphenicol transferase encode
enzymes the activity of which can be determined efficiently by means of
the substrate reacted. This quantitative determination can take place by
means of methods known in the state of the art or as described in the
Examples. The quantitative detection of green-fluorescent protein (GFP),
blue-fluorescent protein (BFP), yellow-fluorescent protein (YFP) can be
carried out based on the bioluminescent properties of these proteins.
Furthermore, a method according to the invention is preferred, wherein the
target gene is selected from the group consisting of:
Keratin, human hair keratin genes: hHa1, hHa2, hHa3-I, hHa3-II, hHa4,
hHa5, hHa6, hHa7, hHa8; hHb1, hHb2, hHb3, hHb4, hHb5, hHb6.
The hair keratin genes mentioned herein are particularly suitable for the
methods according to the invention since they are specifically expressed
during hair production and the proteins encoded by them represent
essential morphological building blocks of the hair. Inhibitors capable of
interfering with the gene expression of these keratins are, thus, also
suitable for inhibiting the production of the essential keratin proteins.
As a consequence, the morphological production of hair is inhibited
efficiently. The expression control sequences mediating the tissue
specificity and the efficiency of the transcription have been
characterised in different hair keratin genes already so that these cis-regulatory
elements are known in the state of the art and can be obtained (Schlake,
Fokhead/Winged-Helix Transcription Factor Whn Regulates Hair Keratin Gene
Expression: Molecular Analysis of the Nude Skin Phenotype", Developmental
Dynamics 217 (2000), 368-376; Dunn et al. Regulation of a hair follicle
keratin intermediate filament gene promoter. J. Cell Sci. 111, 3487-3496
(1998)). Like the relevant cis-regulatory elements of the keratin genes,
transcription factors binding thereto are known in the state of the art.
An example of such a regulatory transcription factor is Whn. Preferably,
Whn binds to a DNA sequence comprising 10 nucleotides and the tretra-nucleotide
5'-ACGC-3'. More preferably, Whn binds to a sequence comprising the
nucleotides 5'agtaagACG'cata-3' (SEQ ID NO: 1). The outstanding role this
transcription factor plays for the production of hair can also be seen
from the loss of its function in mice exhibiting the nude phenotype, the
so-called nude mice. One characteristic of these nude mice is that they do
not develop any body hair, i.e. the process of the production of hair is
efficiently inhibited.
A method of the invention, wherein the reporter gene is inserted into the
cell is also preferred.
The term "inserted" relates to the fact that the expression control
sequence operatively linked with a reporter gene, as also discussed for
the contacting above, is or was introduced into the cell as nucleic acids
by different methods known in the state of the art. In this context, the
reporter gene operatively linked with the expression control sequence can
also be integrated into the genome of the cell stably. Moreover, the
reporter gene can be linked with the endogenous expression control
sequence of a target gene by means of recombination techniques. In this
way, such a reporter gene would be integrated into the locus of the target
gene so that the cis-regulatory elements of the target gene are still
capable of regulating the gene expression, but instead of the actual
target gene transcribe the reporter gene. The advantage of such a cell
with stably integrated reporter gene under the control of a suitable
expression control sequence would be that the step of introducing the
reporter gene linked with the expression control sequence, which would
otherwise be necessary when carrying out the method, could be left out.
The leaving out of this step would make normalisation methods which are
connected therewith and which might be necessary to guarantee the
efficiency of the introduction superfluous. Nevertheless, the methods
according to the invention can also be carried out by introduction of a
reporter gene linked with the expression control sequence carried out
individually in each process cycle. In this context, as already mentioned,
it could be necessary to carry out methods for the normalisation which are
suitable and which are known in the state of the art to make a meaningful
comparison of two cell populations treated differently.
Furthermore, the invention relates to a method for the inhibition of hair
production, wherein the method comprises the contacting of an inhibitor of
hair production with a cell, wherein the cell comprises a factor
stimulating the production of hair which can interact with the inhibitor.
The definitions of the terms of the methods according to the invention
described above are applied mutatis mutandis to the methods described in
the following.
The term "inhibition of production of hair" comprises the inhibition of
individual steps of the biological process of hair production described
above and the whole process. As a consequence of this inhibition, there
can be a total loss of the de novo hair production or an inhibition or
deceleration of the production of hair.
The term "interact" relates to the fact that the inhibitor of the factor
stimulating the production of hair physically interacts therewith. As a
result, the factor is inhibited in its activity and the inhibition of the
production of hair is achieved.
The method according to the invention described herein can be carried out
in suitable in vitro models, such as, for example, cell or organ cultures
of the skin, or, however, in vivo in animal models. With methods according
to the invention carried out in organ cultures of the skin or in vivo in
animal models, a phenotype comparable to the phenotype of nude mice is a
preferred result of the inhibition of the production of hair. The method
can also be used in the therapy for hair growth disorders, as described in
the embodiments regarding applications.
Preferably, the cell used in the methods according to the invention is
selected from the group consisting of:
HeLa, COS-1, COS-7, CHO, epithelial cell lines, primary keratinocytes or
cell lines derived from keratinocytes.
These cells or cell lines are particularly suitable for carrying out the
methods of the invention, since these cells already comprise endogenous
factors stimulating the production of hair or are particularly suitable
for the introduction of exogenous factors, e.g. by transfection. It is
known that these cells can be transfected efficiently, so that in each
case a majority of the cells gets the desired characteristics.
Also, a method according to the invention is preferred, wherein the factor
is encoded by a polynucleotide introduced into the cell.
The term "introduced" was described in detail above already. As described
earlier, it might be necessary to introduce the factor into the cell
exogenously. For this purpose, the introduction of a polynucleotide coding
for the factor is particularly suitable, which, preferably, is introduced
into the cell in the form of an expression construct. Apart from the
polynucleotide, this expression construct comprises expression control
sequences allowing the expression of the factor in the cell. According to
the invention, the terms "polynucleotide" and "nucleic acid" relate to one
and the same subject matters and can, therefore, be exchanged.
From the explanations given above, it also becomes clear that a method
according to the invention is preferred, wherein the inhibitor is encoded
by a polynucleotide introduced into the cell.
Also, a method according to the invention is preferred, wherein the factor
stimulating the production of hair is a transcription factor.
From the explanations given above, it becomes clear that transcription
factors stimulating the production of hair are particularly suitable for
carrying out the methods according to the invention, since they directly
control the expression of the genes relevant for the morphological
production of hair, such as e.g. the hair keratins. Furthermore, it has
already been explained that the factors according to the invention are
proteins structured modularly. Transcription factors comprise at least a
DNA-binding domain and a domain mediating protein interaction and, thus,
have a modular structure.
In this context, a method according to the invention is particularly
preferred, wherein the transcription factor is selected from the group
consisting of Whn, Hairless, LEF-1 and Hoxc13. For these transcription
factors it could be shown already that they play a role in the production
of hair as transcription factors stimulating hair production. Moreover,
the transcription factors mentioned herein exhibit a modular structure
consisting of at least one DNA-binding domain and a domain mediating the
interaction with further factors of the transcription complex.
Furthermore, it is known for LEF-1 that, in addition, it can interact with
cytoplasmic regulator proteins and/or co-factors.
The amino acid sequence for the transcription factors mentioned above is
deposited with the GenBank Accession Numbers Whn: Human Y11739, Lef 1:
Human AF288571, Hoxc13: Human XM006804.
Also, a method according to the invention is preferred, wherein the
inhibitor comprises a domain of the transcription factor, as defined
above.
A protein comprising only one domain of the transcription factor, only has
the biological properties mediated by this domain. Such protein lacks
properties that are mediated by the other domains of the transcription
factor structured modularly and that, on the whole, are essential for its
biological function. With transcription factors structured modularly,
there is at least one domain mediating interactions with other proteins
and one domain mediating the interaction with the cis-regulatory DNA
elements. A protein comprising one domain only can, therefore, interact
either with the further proteins or with the cis-regulatory element, not,
however with the two. Thus, such a protein competes with the transcription
factor for the interaction with either DNA or other proteins. Other
proteins or cis-regulatory elements having bound the protein comprising
the domain can, however, no longer interact with the transcription factor.
Since the protein comprising the individual domain, however, does not have
the biological activity of the whole transcription factor, the molecular
interaction during gene regulation is interrupted by this protein. Thus,
the described protein can act as inhibitor by competition and blocking of
binding sites on either other proteins or cis-regulatory DNA elements.
From the explanations given above, it is clear that in a particularly
preferred embodiment of the method according to the invention, the domain
mediates a protein-DNA or protein-protein interaction.
In a preferred embodiment, a DNA-binding domain comprises the amino acids
254 to 372 of the Whn protein, whereas a domain mediating a
protein-protein interaction, represents the transactivator domain of Whn
comprising the amino acid 474 to 648. Further suitable deletion variants
of Whn comprising one domain only are known in the state of the art and
discussed by Schorpp, "Genetically Separable Determinants of Hair Keratin
Gene Expression", Developmental Dynamics 218 (2000), 537-543. In this
publication, suitable methods are also described which allow the person
skilled in the art to determine the amino acids comprised by a DNA-binding
domain or a transactivator domain. This determination of the domain can
also be carried out by other methods known in the state of the art, such
as e.g. by the "yeast one-hybrid" method or related methods.
Moreover, a method according to the invention is preferred, wherein the
inhibitor exhibits at least an amino acid exchange, an amino acid deletion
or an amino acid insertion compared to the transcription factor defined
above.
Like proteins comprising only a functional domain of a transcription
factor, molecular variants, too, that differ from the transcription factor
by amino acid exchange, amino acid deletion or an amino acid insertion,
can act as competitive inhibitors. In such molecular variants, the
respective amino acid modification in one of the domains of the
transcription factor structured modularly leads to the loss of the
biological properties of this domain so that the molecular variant, like
the protein described above, that comprises one domain of the
transcription factor only, can no longer fulfil the biological function of
the transcription factor; it is, however, still capable of blocking the
molecular interaction during gene regulation by interaction with either
other proteins or cis-regulatory DNA elements.
In the method according to the invention, the amino acid sequence of the
inhibitor, however, is, despite the presence of at least one of the amino
acid modifications explained earlier, at least 70%, preferably 80%, more
preferably 90% or most preferably 95% identical to the amino acid sequence
of the transcription factor defined above.
Therefore, a method according to the invention is particularly preferred,
wherein the amino acid exchange, the amino acid deletion or the amino acid
insertion leads to the loss of the function of at least one domain of the
transcription factor.
Preferably, a variant Whn protein can exhibit an amino acid exchange of an
arginine at position 320 in a cysteine. Such exchange would lead to the
loss of the biological properties of the DNA-binding domain and, thus, to
a Whn protein variant no longer capable of binding DNA, however, capable
of interacting with other proteins by means of the transactivator domain.
The variant of Whn mentioned above is known in the state of the art and
described, for example, in Schlake (2000) loc. cit.
Furthermore, a method according to the invention is preferred, wherein the
factor stimulating the production of hair is a cytoplasmic protein.
Apart from transcription factors, cytoplasmic proteins represent a further
big class of regulators structured modularly. The cytoplasmic proteins
according to the invention are characterised by at least two domains
mediating the interaction with different further proteins. Such proteins
can transfer signals, for example, by being activated themselves by a
first protein via the first domain and then, in activated condition, by
binding or activating a second protein via a second domain. In the end, a
signal mediated by said cytoplasmic proteins regulates the gene expression
of the target genes described above via transcription factors, which are
at the end of the signal transfer cascade consisting of the cytoplasmic
proteins. An example of such cytoplasmic proteins is the .beta.-catenin
participating in the regulation of LEF-1.
As a consequence, a method according to the invention is also preferred,
wherein the inhibitor comprises a domain of the cytoplasmic protein, as
defined above.
In contrast to the transcription factor, in this context, the domains
mediate protein-protein interactions; each domain, however, with a
different protein. Thus, in the case of the cytoplasmic proteins described
herein, too, competitive inhibition is possible. Protein-binding domains
can be determined by different methods known in the state of the art.
These include e.g. "yeast two-hybrid" method, immune precipitation
techniques and direct interaction measurements in vitro by affinity
chromatography and the so-called surface plasmon resonance.
Therefore, a method according to the invention is particularly preferred,
wherein the domain mediates a protein-protein interaction.
Furthermore, a method according to the invention is preferred, wherein the
inhibitor exhibits at least an amino acid exchange, an amino acid deletion
or an amino acid insertion compared to the cytoplasmic protein defined
above.
As described for the transcription factors, the competitive inhibition can
also be mediated by a molecular variant of the cytoplasmic protein, the
biological function of which is impaired by the amino acid modification
mentioned above.
However, in spite of the presence of at least one of the aforementioned
amino acid modifications, the amino acid sequence of the inhibitor is, in
the method of the invention, at least 70%, preferably 80%, more preferably
90% and most preferably 95% identical with the amino acid sequence of the
cytoplasmic protein defined above.
Thus, a method of the invention is particularly preferred, wherein the
amino acid exchange, the amino acid deletion or the amino acid insertion
results in the loss of the function of at least one domain of the
cytoplasmic protein.
Furthermore, a method of the invention is preferred, wherein the factor
stimulating the production of hair is a receptor.
Receptors are also proteins with a modular structure which have at least
two domains that mediate protein-protein interactions. These are, on the
one hand, be the extra-cellular domain that mediates the interaction with
an extra-cellular protein, the ligand, and the intracellular domain that
mediates the interaction with cytoplasmic proteins. As receptors are
so-called transmembrane proteins, they have an additional domain, the
transmembrane domain. This transmembrane domain, however, does not mediate
any protein-protein interaction but anchors the receptor to the
lipid-containing plasma membrane. Like cytoplasmic proteins or
transcription factors, receptors can produce or send signals and can
therefore, in the end, also modulate gene expression of the aforementioned
target genes by means of the signals which they sent.
Moreover, a method according to the invention is preferred wherein the
inhibitor comprises a domain of the receptor as defined before.
As already described for cytoplasmic proteins, individual domains of
proteins with a modular structure, such as receptors, which, by means of
different domains, interact with different proteins are suitable as
competitive inhibitors as they block the molecular interplay.
The protein-binding domains of the receptors can be determined with
various methods described in the state of the art. These include, e.g. the
yeast two-hybrid method, immunoprecipitation methods and direct
interaction measurements in vitro by affinity chromatography and the
so-called surface plasmon resonance.
As a consequence, a method of the invention is particularly preferred in
which the domain mediates a protein-protein interaction.
In addition, a method of the invention wherein the inhibitor has at least
one amino acid exchange, one amino acid deletion or one amino acid
insertion compared to the receptor defined above is preferred.
As described for the transcription factors and cytoplasmic proteins, the
competitive inhibition can also be mediated by a molecular variant of a
receptor, the biological function of which is impaired due to the
aforementioned amino acid modification. However, in the method of the
invention, in spite of the presence of at least one of the explained above
amino acid modifications, the amino acid sequence of the inhibitor is at
least 70%, preferably 80%, more preferably 90% or most preferably 95%
identical with the amino acid sequence of the receptor defined above.
In this case, a method of the invention is particularly preferred in which
the amino acid exchange, the amino acid deletion or the amino acid
insertion leads to the loss of the function of at least one domain of the
receptor.
The invention also relates to a method for the production of a
pharmaceutical composition comprising the steps of the aforementioned
method according to the invention as well as the additional step of
formulating the inhibitor which has been identified and/or obtained in a
pharmaceutically acceptable form of administration. According to the
invention, the term "pharmaceutical composition" defines substances and
preparations of substances which are to heal, alleviate, prevent or
recognise diseases, conditions, damage to the body or pathological
discomforts by administration at or in the human body. During the method
of production according to the invention, medical and/or pharmaceutical
technical adjuvants can be added to the compounds identified with the
methods of the invention. According to the invention, medical adjuvants
are substances which are used for the production (as active ingredients)
of pharmaceutical compositions in a method of the invention.
Pharmaceutical technical adjuvants merely serve the suitable formulation
of the pharmaceutical composition and can, if only required during the
method, even be removed afterwards or form part of the pharmaceutical
composition as pharmaceutically acceptable carriers. Examples of
pharmaceutically acceptable carriers are listed below.
The invention furthermore relates to a pharmaceutical composition
comprising, optionally in a pharmaceutically acceptable form of
administration, an inhibitor of hair production which has been identified
or obtained according to a method of the invention or a polynucleotide
which encodes the inhibitor.
The essential terms of this embodiment have already been explained and
defined above. The pharmaceutical composition is optionally formulated in
combination with a pharmaceutically acceptable carrier and/or diluent.
The person skilled in the art knows examples of pharmaceutically
acceptable carriers. They comprise phosphate-buffered saline, water,
emulsions such as e.g. oil/water emulsions, various kinds of detergents,
sterile solutions, etc. Pharmaceutical compositions comprising such
carriers can be formulated with known conventional methods. These
pharmaceutical compositions can be administered to an individual in a
suitable dosage, e.g. in a range of 1 .mu.g to 100 mg per day and patient.
The administration can be carried out in various ways, e.g. directly on
the skin, intravenously, intraperitoneally, subcutaneously,
intramuscularly, locally or intradermally. Nucleic acids can also be
administered in form of gene therapy. The attending doctor determines the
kind of dosage depending on the clinical factors. The person skilled in
the art knows that the kind of dosage depends on various factors such as
e.g. the size, the surface of the body, the age, the sex or the general
health of the patient, but also on the special agent that is administered,
the duration and kind of the administration and on other medicaments which
are possibly administered in parallel.
The invention also relates to a pharmaceutical composition comprising a
polypeptide that comprises the DNA binding domain but not the
transactivator domain of Whn, LEF-1 or Hoxc13 or a polynucleotide encoding
said polypeptide optionally in a pharmaceutically acceptable carrier.
The invention moreover relates to the use of a polypeptide comprising the
DNA binding domain but not the transactivator domain of Whn, LEF-1 or
Hoxc13 or a polynucleotide encoding said polypeptide, the use of an
inhibitor which has been identified and/or obtained according to a method
of the invention, or of a polynucleotide encoding such an inhibitor for
the production of a pharmaceutical composition for the treatment of hair
growth disorders.
Symptoms of hair growth disorders are known in the state of the art and
have been described in detail in medicinal standard works such as, e.g.
Pschyrembel.
The further preferred or particularly preferred embodiments described for
the methods of the invention apply mutatis mutandis also for the uses
according to the invention.
In this case, a use according to the invention is preferred in which the
hair growth disorder is increased hair growth.
Last but not least, the invention relates to a kit for carrying out the
methods of the invention wherein the kit comprises a cell which comprises
at least one factor stimulating the growth of hair, a reporter gene,
wherein the reporter gene is operatively linked to the expression control
sequence of a target gene of the factor and/or a medium that is suitable
for the detection of the reporter gene.
In this case, the components of the kit according to the invention can be
packaged in containers such as, e.g. vials and tubes, optionally in
buffers and/or other solvents. Under certain circumstances, one or more
components can be packaged in the same container.
Claim 1 of 12 Claims
1. A method for the identification and/or
production of an inhibitor of hair production, which method comprises the
steps of: (a) contacting a cell comprising at least one factor stimulating
hair production as well as a reporter gene which is operatively linked
with the expression control sequence of a target gene of the factor, with
a presumed inhibitor in a medium suitable for the detection of the
reporter gene, wherein said factor stimulating hair production is a
transcription factor selected from the group consisting of Whn, Hairless,
LEF-1 and Hoxc13; (b) quantitative determination of the reporter gene
activation in the cell; (c) quantitative determination of the reporter
gene activation in a cell as defined in (a), without the cell having been
contacted with a presumed inhibitor; and (d) comparing the reporter gene
activation quantitatively determined from (b) and (c), wherein a reduction
or a lack of detectable reporter gene activation in (b) in comparison to
(c) presents an indication for an inhibitor. ____________________________________________
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