Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0027960 (mole)
 21,279 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Melanocyte-stimulating hormone (MSH) has been reported to enhance the experimental metastatic behaviour of melanoma cells in the mouse model. alpha-MSH production and MSH receptor (melanocortin 1 receptor gene) expression have been detected in cultured normal human melanocytes and metastasized melanomas. The exact role of MSH in the metastatic behaviour of human melanoma cells is, however, not yet known. To clarify a possible role of proopiomelanocortin (POMC)-derived peptides, including alpha-MSH, in melanoma development and progression, we analysed immunohistochemically the localization of alpha-MSH adrenocorticotrophic hormone (ACTH) and beta-endorphin in various kinds of benign pigmented naevocytic lesions and malignant melanomas. Three of 21 samples of common and dysplastic naevi showed detectable alpha-MSH staining in naevus cells, and five and six of 15 samples were weakly positive for ACTH and beta-endorphin staining, respectively. In melanoma samples, 24 of 45, 23 of 39 and 30 of 42 samples showed positive staining with alpha-MSH, ACTH and beta-endorphin antibodies, respectively. Furthermore, staining for all three antibodies was noted to be more intense and diffuse in samples of nodular melanoma, vertically growing acral lentiginous melanoma and superficial spreading melanoma as well as metastatic lesions compared with those of naevi. Although it is yet to be determined whether or not this strong staining for POMC-derived peptides in advanced melanoma cells indicates a role of autocrine or paracrine regulation, our results suggest a possible involvement of POMC gene products in melanoma progression.
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PMID:Immunoreactivity of alpha-melanocyte-stimulating hormone, adrenocorticotrophic hormone and beta-endorphin in cutaneous malignant melanoma and benign melanocytic naevi. 974 58

Alpha melanocyte-stimulating hormone (MSH) and related proopiomelanocortin-derived (POMC) peptides bind to the melanocortin 1 receptor (MC1-R) of mammalian melanocytes and stimulate proliferation and melanogenesis. POMC transcripts and alpha-MSH-like immunoreactivity have been found in melanoma cells and a possible autocrine loop involving MC1-R and POMC-derived products has been proposed. Therefore, the alpha-MSH/MC1-R system plays a major role in the biology of melanocytes, and provides targets for melanoma diagnosis and therapy. However, the relative levels of MC1-R expression in normal melanocytes (NM) and melanoma cells are unknown, and it is still debated whether or not all human melanomas express the MC1-R. We describe a semiquantitative RT-PCR assay for MC1-R expression, using a competition vector generated by deleting 164 bp of the native gene. The competitor was employed to analyse a panel of human melanoma cells, tumour samples, giant congenital nevus cells (CNM) and normal melanocytes (NM). All samples were positive for MC1-R expression, but expression of the receptor gene did not correlate with that of tyrosinase. Expression levels were about 10 and 20 times higher for surgical specimens and cultured melanoma cells, respectively, than for NM, but comparable for CNM and NM. Thus, high MC1-R expression is a frequent event in malignant melanocytes, and might lead to a higher activity of the alpha-MSH/MC1-R system in melanoma cells as compared to normal melanocytes, for equal local concentrations of the hormone or related melanocortins.
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PMID:Expression of the MC1 receptor gene in normal and malignant human melanocytes. A semiquantitative RT-PCR study. 1064 13

Systemic stresses induce corticotropin-releasing hormone (CRH) expression in hypothalamus. CRH is released to the pituitary gland, where it stimulates proopiomelanocortin (POMC) production acting via the CRH receptor (CRH-R). CRH and POMC peptides are also detected in sites outside of the central nervous system (CNS), such as the skin. However, it has not been elucidated whether these peptides detected in the skin are derived from CNS or are produced locally. Using immunohistochemical and in situ reverse-transcription (RT)-PCR techniques, we demonstrated coexpression of CRH and POMC mRNAs in the epidermis and pilosebaceous units of the human skin. This coexpression was confirmed by the combination of laser-capture microdissection (LCM) with RT-PCR, analyzing mRNA expressions in captured sebaceous cells. Immunoreactivities and expressions of CRH and POMC mRNAs were strong in inflammatory lesions, melanocytic nevus, seborrheic keratosis, and also in the periphery of the benign tumor. These findings suggest that CRH and POMC peptides are produced locally in the skin and are regulated by inflammatory cells as well as by autocrine mechanisms. The skin may have "a local stress response system," whose activity is mediated by CRH and POMC peptides, in an equivalent to hypothalamus-pituitary adrenal axis.
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PMID:In situ expression of corticotropin-releasing hormone (CRH) and proopiomelanocortin (POMC) genes in human skin. 1151 29