School of Life Sciences and Biotechnology, Korea University, Seoul, Korea.
Autophagy. 2012 Nov;8(11):1684-5. doi: 10.4161/auto.21487. Epub 2012 Aug 9.
Although elevated expression of CAV1/caveolin 1 is associated with the malignant progression of various human cancers, the molecular mechanism underlying its oncogenic functions is largely unknown. We found that CAV1 is frequently overexpressed in advanced colorectal tumors due to aberrant promoter CpG site hypomethylation, and its elevation is implicated in enhanced aerobic glycolysis of tumor cells. Depletion of elevated CAV1 downregulates glucose uptake, intracellular ATP level and lactate accumulation, and triggers autophagy through activation of AMPK-TP53/p53 signaling. CAV1 elevation increases glucose uptake and ATP production by stimulating transcription of the glucose transporter SLC2A3/GLUT3 via an HMGA1-binding site within the promoter. Collectively, our study suggests that elevated CAV1 expression may contribute to colorectal tumor progression by providing tumor cells growth and survival advantages under nutritional stress conditions.
虽然 CAV1/窖蛋白 1 的表达升高与各种人类癌症的恶性进展相关,但它的致癌功能的分子机制在很大程度上仍是未知的。我们发现 CAV1 在晚期结直肠肿瘤中经常过表达,这是由于启动子 CpG 位点异常低甲基化,其升高与肿瘤细胞有氧糖酵解增强有关。敲低升高的 CAV1 会下调葡萄糖摄取、细胞内 ATP 水平和乳酸积累,并通过激活 AMPK-TP53/p53 信号通路引发自噬。CAV1 的升高通过刺激葡萄糖转运蛋白 SLC2A3/GLUT3 的转录,从而增加葡萄糖摄取和 ATP 生成,该转录通过启动子内的 HMGA1 结合位点进行。总的来说,我们的研究表明,升高的 CAV1 表达可能通过在营养应激条件下为肿瘤细胞的生长和存活提供优势,从而促进结直肠肿瘤的进展。