Fan Meiyun, Pfeffer Susan R, Lynch Henry T, Cassidy Pamela, Leachman Sancy, Pfeffer Lawrence M, Kopelovich Levy
Department of Pathology and Laboratory Medicine, and the Center for Cancer Research, University of Tennessee Health Science Center, Memphis, TN, USA.
Oncotarget. 2013 Jan;4(1):128-41. doi: 10.18632/oncotarget.786.
Familial melanoma (FM) is a dominantly heritable cancer that is associated with mutations in the tumor suppressor CDKN2A/p16. In FM, a single inherited "hit" occurs in every somatic cell, enabling interrogation of cultured normal skin fibroblasts (SFs) from FM gene carriers as surrogates for the cell of tumor origin, namely the melanocyte. We compared the gene expression profile of SFs from FM individuals with two distinct CDKN2A/p16 mutations (V126D-p16 and R87P-p16) with the gene expression profile of SFs from age-matched individuals without p16 mutations and with no family history of melanoma. We show an altered transcriptome signature in normal SFs bearing a single-hit inherited mutation in the CDKN2A/p16 gene, wherein some of these abnormal alterations recapitulate changes observed in the corresponding cancer. Significantly, the extent of the alterations is mutation-site specific with the R87P-p16 mutation being more disruptive than the V126D-p16 mutation. We also examined changes in gene expression after exposure to ultraviolet (UV) radiation to define potential early biomarkers triggered by sun exposure. UV treatment of SFs from FM families induces distinct alterations in genes related to cell cycle regulation and DNA damage responses that are also reported to be dysregulated in melanoma. Importantly, these changes were diametrically opposed to UV-induced changes in SF from normal controls. We posit that changes identified in the transcriptome of SF from FM mutation carriers represent early events critical for melanoma development. As such, they may serve as specific biomarkers of increased risk as well as molecular targets for personalized prevention strategies in high-risk populations.
家族性黑色素瘤(FM)是一种显性遗传性癌症,与肿瘤抑制基因CDKN2A/p16的突变有关。在FM中,每个体细胞都会发生一次遗传性“打击”,这使得对FM基因携带者培养的正常皮肤成纤维细胞(SFs)进行研究成为可能,这些细胞可作为肿瘤起源细胞(即黑素细胞)的替代物。我们比较了携带两种不同CDKN2A/p116突变(V126D-p16和R87P-p16)的FM个体的SFs与年龄匹配的无p16突变且无黑色素瘤家族史个体的SFs的基因表达谱。我们发现,携带CDKN2A/p16基因单打击遗传性突变的正常SFs的转录组特征发生了改变,其中一些异常变化重现了在相应癌症中观察到的变化。值得注意的是,变化程度具有突变位点特异性,R87P-p16突变比V126D-p16突变更具破坏性。我们还研究了紫外线(UV)辐射后基因表达的变化,以确定阳光照射引发的潜在早期生物标志物。对FM家族的SFs进行UV处理会诱导与细胞周期调控和DNA损伤反应相关的基因发生明显变化,这些变化在黑色素瘤中也被报道为失调。重要的是,这些变化与正常对照的SFs中UV诱导的变化截然相反。我们认为,FM突变携带者的SFs转录组中确定的变化代表了黑色素瘤发展的关键早期事件。因此,它们可能作为高风险人群中风险增加的特异性生物标志物以及个性化预防策略的分子靶点。