2013年4月11日訊 /生物谷BIOON/--由於今沒有有效的治療黑色素瘤的方法，黑色素瘤成為皮膚癌中一類致死率很高的癌症。棉纖維素（gossypin）是水果蔬菜中的一種天然產物，科學家首次發現了棉纖維素能夠治療黑色素瘤。相關報答發表在3月29日的Molecular Cancer Therapeutics雜誌上。
德州生物醫學中心的Hareesh Nair博士稱，在黑色素瘤病人中，主要是兩種蛋白突變分別是BRAFV600E kinase和CDK4，而我們的結果顯示棉纖維素能夠抑制這兩種突變蛋白功能，棉纖維素有望開發成為治療黑色素瘤藥物。
Nair博士和他的研究團隊在體外實驗中發現棉纖維素能夠抑制人類黑色素瘤細胞繁殖。棉纖維素可能通過直接結合作用，抑制突變BRAFV600E kinase和CDK4蛋白功能。在體實驗中，研究人員對黑色素瘤模型小鼠應用棉纖維素治療，發現治療十天後腫瘤體積明顯變小，小鼠生存率也同時提高。
Nair博士計劃進一步研究機體吸收棉纖維素機制，並進一步在黑色素瘤病人中檢測棉纖維素的治療效果。（生物谷Bioon.com）
Gossypin as a Novel Selective Dual Inhibitor of v-raf Murine Sarcoma Viral Oncogene Homolog B1 and Cyclin-Dependent Kinase 4 for Melanoma.
S. Bhaskaran, K. V. Dileep, S. S. Deepa, C. Sadasivan, M. Klausner, N. K. Krishnegowda, R. R. Tekmal, J. L. VandeBerg, H. B. Nair
Mutation in the BRAF gene (BRAFV600E) exists in nearly 70% of human melanomas. Targeted therapy against BRAFV600E kinase using a recently identified RAF-selective inhibitor, PLX4032, has been successful in early clinical trials. However, in patients with the normal BRAF allele (wild-type), PLX4032 is protumorigenic. This conundrum identifies the unmet need for novel therapeutic agents to target BRAFV600E kinase that are not counterproductive. We have identified gossypin, a pentahydroxy flavone, as a potent antimelanoma agent. Gossypin inhibited human melanoma cell proliferation, in vitro, in melanoma cell lines that harbor both BRAFV600E kinase and cyclin-dependent kinase 4 (CDK4) as well as in cells with BRAF wild-type allele. Gossypin inhibited kinase activities of BRAFV600E and CDK4, in vitro, possibly through direct binding of gossypin with these kinases, as confirmed by molecular docking studies. For cells harboring the BRAFV600E, gossypin inhibited cell proliferation through abrogation of the MEK–ERK–cyclin D1 pathway and in cells with BRAF wild-type allele, through attenuation of the retinoblastoma–cyclin D1 pathway. Furthermore, gossypin significantly inhibited melanoma growth in an organotypic three-dimensional skin culture mimicking human skin. Gossypin (10 and 100 mg/kg) treatment for 10 days in human melanoma (A375) cell xenograft tumors harboring BRAFV600E significantly reduced tumor volume through induction of apoptosis and increased survival rate in mice, and the effect was significantly superior to that of PLX4032 (10 mg/kg) or roscovitine 10 mg/kg. In summary, this study identified gossypin as a novel agent with dual inhibitory effects for BRAFV600E kinase and CDK4 for treatment of melanoma