Pro Apoptotic Activity of Caveolin1

Caveolin-1 can also acts as a pro-apoptotic protein. This was originally observed in Rat-1 fibroblasts, where overexpression of caveolin 1 sensitizes the cells to both g-irradiation and ceramide-induced cell death [78]. Elevated sensitivity to apoptotic stimuli was also reported in caveolin-1-transfected OVCAR-3 ovarian carcinoma cells [65] and T24 bladder cancer cells [79], and in mouse embryo fibroblasts that transgenically overexpress caveolin-1 [80]. Activation of caspase-3 was reported to occur in three OVCA ovarian cancer cell lines upon expression of caveolin-1 [70]. Supporting these data, caveolin-1 antisense-suppressed NIH-3T3 cells were reported to be more resistant to staurosporine-induced apoptosis [79]. Similarly, ret-roviral disruption of the caveolin-1 gene in L929 murine fibrosarcoma cells caused resistance to tumor necrosis factor-a (TNF-a)-, hydrogen peroxide- and staurospor-ine-induced apoptosis, whereas forced caveolin-1 expression sensitized HepG2 human hepatocellular carcinoma cells to TNF-a [81]. Caveolin-1 expression also sensitizes HeLa human cervical carcinoma cells to sodium arsenite and hydrogen peroxide toxicity [82]. In addition, adenoviral overexpression of caveolin-1 was found to inhibit platelet-derived growth factor (PDGF)-induced proliferation of primary vascular smooth muscle cells (VSMCs), leading to apoptosis [83]. Collectively, the results of these studies indicate that the growth-inhibitory actions of caveolin-1 may sometimes be accompanied by a pro-apoptotic activity.

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Essentials of Human Physiology

Essentials of Human Physiology

This ebook provides an introductory explanation of the workings of the human body, with an effort to draw connections between the body systems and explain their interdependencies. A framework for the book is homeostasis and how the body maintains balance within each system. This is intended as a first introduction to physiology for a college-level course.

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