Role of cyclophilin B in tumorigenesis and cisplatin resistance in hepatocellular carcinoma in humans

• DOI: 10.1002/hep.24539
• Publication Date: 2011-07-11T17:32:51Z
• Authors: Yeonghwan Kim; Miran Jang; Sangbin Lim; Hyeran Won; Kyung-Sik Yoon; Jae-Hoon Park; Hyo Jong Kim; Byung-Ho Kim; Won-Sang Park; Joohun Ha; Sung-Soo Kim
• Keywords: Male; 0301 basic medicine; Mice, Inbred BALB C; Carcinoma, Hepatocellular; Neovascularization, Pathologic; Liver Neoplasms; Mice, Nude; Antineoplastic Agents; Apoptosis; Hep G2 Cells; Hydrogen Peroxide; Hypoxia-Inducible Factor 1, alpha Subunit; 3. Good health; Cyclophilins; Mice; 03 medical and health sciences; Drug Resistance, Neoplasm; Colonic Neoplasms; Animals; Humans; Female; Cisplatin; Hypoxia

Cyclophilin B (CypB) performs diverse roles in living cells, but its role in hepatocellular carcinoma (HCC) is largely unclear. To reveal its role in HCC, we investigated the induction of CypB under hypoxia and its functions in tumor cells in vitro and in vivo. Here, we demonstrated that hypoxia-inducible factor 1α (HIF-1α) induces CypB under hypoxia. Interestingly, CypB protected tumor cells, even p53-defective HCC cells, against hypoxia- and cisplatin-induced apoptosis. Furthermore, it regulated the effects of HIF-1α, including those in angiogenesis and glucose metabolism, via a positive feedback loop with HIF-1α. The tumorigenic and chemoresistant effects of CypB were confirmed in vivo using a xenograft model. Finally, we showed that CypB is overexpressed in 78% and 91% of the human HCC and colon cancer tissues, respectively, and its overexpression in these cancers reduced patient survival. Conclusions: These results indicate that CypB induced by hypoxia stimulates the survival of HCC via a positive feedback loop with HIF-1α, indicating that CypB is a novel candidate target for developing chemotherapeutic agents against HCC and colon cancer. (Hepatology 2011;).