A Lactate-Induced Response to Hypoxia
CELL
Authors: Lee, Dong Chul; Sohn, Hyun Ahm; Park, Zee-Yong; Oh, Sangho; Kang, Yun Kyung; Lee, Kyoung-min; Kang, Minho; Jang, Ye Jin; Yang, Suk-Jin; Hong, Young Ki; Noh, Hanmi; Kim, Jung-Ae; Kim, Dong Joon; Bae, Kwang-Hee; Kim, Dong Min; Chung, Sang J.; Yoo, Hyang Sook; Yu, Dae-Yeul; Park, Kyung Chan; Yeom, Young Il
Abstract
Organisms must be able to respond to low oxygen in a number of homeostatic and pathological contexts. Regulation of hypoxic responses via the hypoxia-inducible factor (HIF) is well established, but evidence indicates that other, HIF-independent mechanisms are also involved. Here, we report a hypoxic response that depends on the accumulation of lactate, a metabolite whose production increases in hypoxic conditions. We find that the NDRG3 protein is degraded in a PHD2/VHL-dependent manner in normoxia but is protected from destruction by binding to lactate that accumulates under hypoxia. The stabilized NDRG3 protein binds c-Raf to mediate hypoxia-induced activation of Raf-ERK pathway, promoting angiogenesis and cell growth. Inhibiting cellular lactate production abolishes the NDRG3-mediated hypoxia responses. Our study, therefore, elucidates the molecular basis for lactate-induced hypoxia signaling, which can be exploited for the development of therapies targeting hypoxia-induced diseases.
CXCL5, the upregulated chemokine in patients with uterine cervix cancer, in vivo and in vitro contributes to oncogenic potential of Hela uterine cervix cancer cells
BIOMEDICINE & PHARMACOTHERAPY
Authors: Feng, Xiaona; Zhang, Danfeng; Li, Xinyi; Ma, Shuxia; Zhang, Chunbin; Wang, Jingtao; Li, Yue; Liang, Lichun; Zhang, Pengxia; Qu, Yikun; Zhang, Zeyu; Yang, Zhe; Xiang, Yu; Zhang, Weili; Wang, Shuqiu; Shao, Wenwu; Wang, Weiqun
Abstract
CXCL5 is showed a surprisingly elevated profile and implicated in tumorigenesis in several tumors. However, the expression and function of CXCL5 in uterine cervix cancer (UCC) remain largely unknown. The current study aimed to elucidate the expression pattern of CXCL5 in human UCC tissues and Hela cervix cancer cell, as well as its functions in Hela cells. Our data showed that CXCL5 and its receptor CXCR2 were expressed by Hela uterine cervix cancer cells. CXCL5 was upregulated in UCC tissues, and its overexpression was positively correlated with age, but did not correlate with clinical stages and tumor infiltration. Exogenous administration of CXCL5 and CXCL5 overexpression contributed to proliferation and migration activities of Hela cells in vitro, consistent with this, CXCL5 overexpression also promoted growth of Hela cells in a nude mouse xenograft model. At the gene level, CXCL5 overexpression regulated the expression of tumor-related genes including ERK, p-ERK, AKT, p-AKT, DIABOL, NUMB, NDRG3 and CXCR2. Taken together, CXCL5 may contribute to a dominant role in UCC progression and sever as a potential molecular therapeutic target for UCC.