Shathasivam Premalatha, Kollara Alexandra, Spybey Thomasina, Park Soyeon, Clarke Blaise, Ringuette Maurice J, Brown Theodore J
Lunenfeld-Tanenbaum Research Institute at Mount Sinai Hospital, 60 Murray Street, Toronto, M5T 3L9 ON, Canada.
Department of Obstetrics and Gynecology, University of Toronto, 123 Edward Street, Toronto, M5G 1E2 ON, Canada.
Br J Cancer. 2017 Apr 11;116(8):1065-1076. doi: 10.1038/bjc.2017.51. Epub 2017 Mar 16.
VEPH1 is amplified in several cancers including ovarian but its impact on tumour progression is unknown. Previous work has shown that VEPH1 inhibits TGFβ signalling while its Drosophila ortholog increases tissue growth, raising the possibility that VEPH1 could impact tumour growth or progression.
A CRISPR approach was used to disrupt VEPH1 expression in ovarian cancer ES-2 cells, while VEPH1-negative SKOV3 cells were stably transfected with VEPH1 cDNA. The impact of altered VEPH1 expression was assessed using in vitro and in vivo assays and mechanistic studies were performed in vitro.
VEPH1 expression in SKOV3 cells resulted in a reduced tumour growth rate associated with increased necrotic area, and decreased microvessel density and VEGF-A levels relative to tumours formed by mock-transfected cells. VEPH1 expression also decreased VEGFA and IL8 expression in SKOV3 cells and was associated with decreased activated AKT levels. These effects were not observed in ES-2 cells, which bear a BRAF activating mutation that leads to constitutively increased IL8 and VEGFA expression.
VEPH1 expression in SKOV3 ovarian cancer cells inhibits AKT activation to decrease VEGFA and IL8 expression, which leads to decreased tumour vascularisation and progression.
VEPH1在包括卵巢癌在内的多种癌症中存在扩增，但其对肿瘤进展的影响尚不清楚。先前的研究表明，VEPH1可抑制TGFβ信号传导，而其果蝇同源物可促进组织生长，这增加了VEPH1可能影响肿瘤生长或进展的可能性。
采用CRISPR方法破坏卵巢癌ES-2细胞中VEPH1的表达，同时用VEPH1 cDNA稳定转染VEPH1阴性的SKOV3细胞。通过体外和体内实验评估VEPH1表达改变的影响，并在体外进行机制研究。
与mock转染细胞形成的肿瘤相比，SKOV3细胞中VEPH1的表达导致肿瘤生长速率降低，坏死面积增加，微血管密度降低以及VEGF-A水平降低。VEPH1的表达还降低了SKOV3细胞中VEGFA和IL8的表达，并与活化的AKT水平降低有关。在ES-2细胞中未观察到这些效应，ES-2细胞携带BRAF激活突变，导致IL8和VEGFA表达持续增加。
SKOV3卵巢癌细胞中VEPH1的表达抑制AKT激活，从而降低VEGFA和IL8的表达，导致肿瘤血管生成和进展减少。
