美国国家卫生研究所的研究人员3月29日为一种“致癌”基因“平反”。他们指出，这种名为MMP-8基因的实际作用是抑制黑素瘤等皮肤癌的发展。
研究人员在英国《自然—遗传学》杂志上报告说，他们找到的这种基因是基质金属蛋白酶（MMP）基因中的一种，以前人们曾认为MMP-8是致癌基因，但新研究表明，它实际上是一种肿瘤抑制基因。
基质金属蛋白酶可以帮助人体降解某些蛋白质，在修复皮肤晒伤和切伤等过程中发挥关键作用。不过长期以来，科学家一直认为所有基质金属蛋白酶基因都是致癌基因，会增加罹患乳腺癌、结肠癌和黑素瘤等多种癌症的风险。
进一步的动物实验也证实，如果给实验鼠注射含正常MMP-8基因的细胞，它们没有出现罹患黑素瘤的症状。而如果给实验鼠注射含变异MMP-8基因的细胞，它们就比较容易出现上述症状，且肿瘤会发生肺部转移。
研究人员指出：“这项研究表明，对治疗皮肤癌而言，更好的途径是开发那些能恢复或增强正常MMP-8基因功能的药物，或者开发那些只抑制真正致癌的MMP基因的药物。”
黑素瘤是一种危险性很大、很难治疗的皮肤癌，日晒过度是引发黑素瘤的主要原因之一。（生物谷Bioon.com）
生物谷推荐原始出处：
Nature Genetics 29 March 2009 | doi:10.1038/ng.340
Analysis of the matrix metalloproteinase family reveals that MMP8 is often mutated in melanoma
Lavanya H Palavalli1, Todd D Prickett1, John R Wunderlich2, Xiaomu Wei1, Allison S Burrell1, Patricia Porter-Gill1, Sean Davis2, Chenwei Wang1, Julia C Cronin1, Neena S Agrawal1, Jimmy C Lin3, Wendy Westbroek1, Shelley Hoogstraten-Miller1, Alfredo A Molinolo4, Patricia Fetsch2, Armando C Filie2, Michael P O'Connell5, Carolyn E Banister6, Jason D Howard7, Phillip Buckhaults6, Ashani T Weeraratna5, Lawrence C Brody1, Steven A Rosenberg2 & Yardena Samuels1
A mutational analysis of the matrix metalloproteinase (MMP) gene family in human melanoma identified somatic mutations in 23% of melanomas. Five mutations in one of the most commonly mutated genes, MMP8, reduced MMP enzyme activity. Expression of wild-type but not mutant MMP8 in human melanoma cells inhibited growth on soft agar in vitro and tumor formation in vivo, suggesting that wild-type MMP-8 has the ability to inhibit melanoma progression.
1 National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland, USA.
2 National Cancer Institute, National Institutes of Health, Bethesda, Maryland, USA.
3 The Ludwig Center for Cancer Genetics and Therapeutics, the Johns Hopkins Kimmel Cancer Center, Baltimore, Maryland, USA.
4 Oral and Pharyngeal Cancer Branch, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, Maryland, USA.
5 Laboratory of Immunology, National Institute on Aging, National Institutes of Health, Baltimore, Maryland, USA.
6 University of South Carolina School of Medicine, Columbia, South Carolina, USA.
7 The Sidney Kimmel Comprehensive Cancer Center at Johns Hopkins, Baltimore, Maryland, USA.
