Inventors: Angela M. Christiano
Publication date: 2007-06-29
Abstract:
The present invention provides for methods of inhibiting hair growth, comprising decreasing the level of TRPS1 mRNA and/or protein in hair follicle cells of a subject. The present invention also provides for methods of promoting hair growth, comprising increasing the level of TRPS1 mRNA and/or protein in hair follicle cells of a subject. The level of TRPS1 may be decreased or increased either directly, for example by introducing, into a hair follicle cell, a TRPS1 mRNA or protein. Alternatively, the level of TRPS1 may be decreased or increased indirectly, by providing an agent that results in decreased or increased expression of an endogenous TRPS1 gene. The invention also provides for transgenic animals with aberrancies in TRPS1 expression, and for assay systems (including transgenic animals and cell-based systems) that may be used to identify agents that decrease or increase TRPS1 expression.
First Claim:
A method of promoting hair growth in a subject comprising increasing the level and/or activity of TRPS1 mRNA and/or protein in a cell of the subject
Background:
TRPS1 is a nuclear protein of the GATA family, and has nine predicted zinc finger domains, including a single carboxyl-terminal GATA-type zinc finger (Malik et al., 2002, Mol. Cell Biol. 22(24):8592-8600; Malik et al., 2001, EMBO J. 20:1715-1725; Momeni et al., 2000, Nat. Genet. 24:71-74). Members of the GATA family are transcription factors that play important roles in development. Besides the GATA motif, homology between TRPS1 and other proteins is limited to two C-terminal zinc fingers which are closely related to a domain found in the Ikaros family of lymphoid transcription factors (Malik et al., 2002, supra). In contrast to other vertebrate GATA proteins, TRPS1 behaves as a potent, sequence-specific transcriptional repressor in vitro and in vivo, and the repression function maps to the Ikaros domain (Malik et al., 2002, supra; Malik et al., 2001, supra).
Clinically in humans, TRPS1 protein expression is down-regulated by androgens in human prostate cancer (TRPS1 is also known in the art as "GC79"), and analysis of TRPS1 mRNA expression levels in several human tissues showed that the highest levels were observed in normal and tumor breast tissue (Chang et al., 2004, Endocrine-Related Cancer 11:815-822; Chang et al., 2000, J. Natl. Cancer Inst. 92(17):1414-1421). Monoallelic mutations in TRPS1 are associated with the tricho-rhino-phalangeal syndromes (hence, "TRPS"), dominantly inherited conditions characterized by developmental defects in the face, selected bones, and hair, which tends to be sparse and slow growing (Momeni et al., 2000, supra). Deletion of the GATA domain of TRPS1 has been linked to the absence of facial hair (Malik et al., 2002, supra). These clinical observations, as well as the phenotypes of mice carrying TRPS1 mutations, have lead Malik et al. (2002, supra) to suggest that TRPS1 may play a role in hair follicle morphogenesis (see also Kunath et al., 2002, Gene Expr. Patterns 2(1-2):119-122).
TRPS1 resides on human chromosome 8. In addition to tricho-rhino-phalangeal syndrome, several other clinical conditions have been associated with mutations in the region of chromosome 8 occupied by TRPS1. Ambras syndrome, a congenital condition characterized by marked hair overgrowth (hypertrichosis), has been associated with a balanced pericentric inversion in chromosome 8, at or near the location of the TRPS1 gene (Tadin-Strapps et al., 2004, Cytogenet. Genome Res. 107(1-2):68-76; Tadin et al., 2001, Am. J. Med. Genet. 102(1):100-104). In addition, a patient manifesting exostoses, mental retardation and hypertrichosis was found to have a submicroscopic interstitial deletion at chromosome locus 8q24 (Wuyts et al., 2002, Am. J. Med. Genet. 113:326-332).
Prior to the present invention, the fact that certain genetic mutations in the region of TRPS1 result in sparse hair (e.g., tricho-rhino-phalangeal syndrome) while others result in hair overgrowth, or "hypertrichosis" (e.g., Ambras syndrome and the patient described in Wuyts et al., supra), made the role of TRPS1 in hair growth uncertain.
Summary:
The present invention provides for methods and compositions for inhibiting hair growth by decreasing the level and/or activity of TRPS1 mRNA and/or protein. The present invention further provides for methods and compositions for promoting hair growth by increasing the level and/or activity of TRPS1 mRNA and/or protein.
In a first set of embodiments, the present invention provides for methods for identifying agents that may be used to inhibit hair growth, comprising exposing an appropriate test cell or organism to a test agent, and then determining whether expression of TRPS1 is decreased relative to the level of TRPS1 in a control cell or organism not exposed to the test agent. The ability of an agent to decrease TRPS1 indicates that it may be used to inhibit hair growth.
In a second set of embodiments, the present invention provides for methods for identifying agents that may be used to promote hair growth, comprising exposing an appropriate test cell or organism to a test agent, and then determining whether expression of TRPS1 is increased relative to the level of TRPS1 in a control cell or organism not exposed to the test agent. The ability of the agent to increase the level of TRPS1 indicates that the agent may be used to promote hair growth.
In a third set of embodiments, the present invention provides for methods of promoting hair growth comprising increasing the level and/or activity of TRPS1 mRNA and/or protein in cells, preferably hair follicle cells, and more preferably dermal papilla cells, of a subject. The level of TRPS1 may be increased either directly, for example by introducing, into a hair follicle cell, TRPS1 mRNA or protein, or it may be increased indirectly, by providing an agent that results in increased expression of an endogenous TRPS1 gene, increased functional activity of TRPS1 protein, or increased expression of a target of TRPS1.
In a fourth set of embodiments, the present invention provides for methods of inhibiting hair growth in a subject comprising decreasing the level and/or activity of TRPS1 mRNA and/or protein in a cell of the subject. In a particular embodiment, the level and/or activity of TRPS1 is decreased by providing an agent that results in decreased expression of an endogenous TRPS1 gene, decreased functional activity of a TRPS1 protein, or decreased expression and/or activity of a target of a TRPS1 protein. In a particular embodiment, the agent is a catalytic nucleic acid, an antisense oligonucleotide or a siRNA directed to the endogenous TRPS1 gene. In an alternate embodiment, the agent is a catalytic nucleic acid, a siRNA or an antisense oligonucleotide directed to a target of TRPS1, such as Prdm1, Sox 18 or Dkk4, as nonlimiting examples.
In a fifth set of embodiments, the present invention provides for a transgenic non-human animal containing a transgene which interrupts or otherwise disrupts expression of at least one TRPS1 gene, including (i) so-called "knock-out" animals as well as (ii) animals in which the transgene encodes an antisense TRPS1 nucleic acid operably linked to a promoter element, wherein the promoter element may be constitutively active or inducible in hair follicle cells of the animal. Such transgenic animals may be used to study the relationship between TRPS1 expression and hair growth, and may be used in screening methods to identify agents that modulate TRPS1 expression.
In a sixth set of embodiments, the present invention provides for a transgenic non-human animal containing a transgene comprising a TRPS1 gene, operably linked to a promoter element, wherein the promoter element may be constitutively active or inducible in hair follicle cells of the animal. Such transgenic animals may be used to study the relationship between TRPS1 expression and hair growth, and may be used in screening methods to identify agents that increase TRPS1 expression.
In a seventh set of embodiments, the present invention provides for compositions that may be used to inhibit hair growth, which may comprise TRPS1-directed antisense, siRNA, and/or catalytic nucleic acids and/or agents that indirectly inhibit TRPS1 expression.
In an eighth set of embodiments, the present invention provides for compositions that may be used to promote hair growth, which may comprise TRPS1 nucleic acid and/or protein, agents that indirectly modulate TRPS1 expression, and/or hair follicle cells in which TRPS1 expression is increased or which have been administered TRPS1 protein.
In a ninth set of embodiments, the present invention provides for methods of inhibiting hair growth comprising decreasing levels of targets of TRPS1 mRNA and/or protein in cells, preferably hair follicle cells, of a subject. In specific, nonlimiting embodiments, levels of expression of TRPS1 targets, for example, Prdm1, Sox18, and Dkk4, may be decreased by administering, to hair follicle cells, RNAi, antisense oligonucleotide, or catalytic nucleic acids that comprise regions that are complementary to Prdm1, Sox18 or Dkk4 mRNA.
In an tenth set of embodiments, the present invention provides for a method of treating alopecia in a subject comprising administering to cells, preferably hair follicle cells, of the subject, an agent that increases the level of TRPS1 mRNA and/or protein in at least a proportion of cells to which it is administered. In nonlimiting specific embodiments, the alopecia being treated is male pattern baldness in a human. |
|
|
|
