High Expression of HIF-1α, BNIP3 and PI3KC3: Hypoxia-Induced Autophagy Predicts Cholangiocarcinoma Survival and Metastasis

Abstract

Hypoxia and autophagy are known to facilitate tumor progression. We here aimed to investigate the role of hypoxia-associated autophagy in cholangiocarcinoma (CCA) survival and metastasis. Immunostaining of hypoxicresponsive proteins (HIF-1α and BNIP3) and a key regulator of autophagy (PI3KC3) were examined in CCA tissues and their expression levels were compared with clinicopathological parameters. A hypoxia mimicking condition (CoCl 2 treatment) was also tested regarding CCA cell functions. Our results showed that HIF-1α (66%), BNIP3 (44%) and PI3KC3 (46%) showed strong staining in human CCA tissues. Positive expression of HIF-1α (p=0.033), BNIP3 (p=0.040) and PI3KC3 (p=0.037) was significantly correlated with lymph node metastasis. HIF-1α was well associated with BNIP3 (r=0.3, p<0.01) and PI3KC3 (r=0.2, p<0.01). The survival rates of patients who were positive with HIF-1α (p=0.047) or co-expressed HIF-1α and BNIP3 (p=0.032) or HIF-1α and PI3KC3 (p=0.043) were significantly greater than in the negative groups. CCA cells treated with CoCl 2 showed an increase in HIF-1α, BNIP3, PI3KC3 and LC3-II, with increased cell migration and pFAK levels. These data suggest that hypoxia associated autophagy enhances CCA metastasis, resulting in a poor prognosis of CCA.

Chloroquine Exerts Anti-metastatic Activities Under Hypoxic Conditions in Cholangiocarcinoma Cells

“…This experimental study points to a fundamental effect of CQ on CCA cell metastasis under hypoxiamimicking condition. We created an in vitro hypoxia-like state by treatment of two CCA cell lines with 100 μM of CoCl 2 (Liu et al, 1999;Law et al, 2012;Thongchot et al, 2014). We demonstrated that CoCl 2 -induced hypoxia significantly increased metastases in both CCA cell lines, using a transwell migration assay.…”

“…Recent studies have demonstrated that the behavior of CCA cell lines is significantly affected by hypoxia (Seubwai et al, 2012;Thongchot et al, 2014). We applied 100 μM CoCl 2 to provide the hypoxic-mimic conditions for CCA cell culture, and trans-migrating cells were evaluated.…”

“…It has been showed that 100 μM of CoCl 2 treatments to human prostate cancer cell lines resulted in elevated VEGF mRNA and protein secretion, and drove cells to be highly invasive metastatic phenotype (Liu et al, 1999). In addition, a recent study has demonstrated that CCA cells treated with 100 μM of CoCl 2 increased HIF-1α expression that contributed to the progression by metastatic potential (Thongchot et al, 2014). The hypoxic microenvironment is very important in regulating tumor processes such as epithelial-mesenchymal transition (EMT) that is believed to be a major mechanism by which cancer cells become metastatic and invasive (Zhang et al, 2013).…”

Association of CYP39A1, RUNX2 and Oxidized Alpha-1 Antitrypsin Expression in Relation to Cholangiocarcinoma Progression

“…A major mechanism linking between inflammation and CCA is related to the generation of free radicals such as superoxide anion (O2¯•), nitric oxide (NO) and other reactive oxygen (ROS) * and nitrogen species (RNS) which cause DNA damage and the alteration of gene expressions in both a hamster animal model and humans (Jaiswal et al, 2000;Pinlaor et al, 2003;Thanan et al, 2008;Yongvanit et al, 2012b). Regarding to the molecular mechanism underlining CCA progression, there are some studies have demonstrated aberrant expression of potential genes involving in CCA (Kunlabut et al, 2012;Namwat et al, 2012;Thongchot et al, 2014). In addition, several studies show that oxidative DNA damage plays a role in not only DNA mutation but also genetic instability and epigenetic changes which could be involved in all steps of inflammation-related carcinogenesis (Murata et al, 2012).…”

Inhibitory Effects of Dunning Rat Prostate Tumor Fluid on Proliferation of the Metastatic MAT-LyLu Cell Line

“…The clinical importance of this situation is the fact that the intercellular fluid causes a decrease in the effectiveness of the treatment without being given at the targeted therapeutic dose into the tumor tissue of the applied antitumoral agents, besides the possibility of that fluid movement to facilitate the lymphatic invasion and metastasis. In the meantime, the hypoxic microenvironment caused by the insufficient circulation has a negative influence on the effectiveness of the radiation therapy (Milosevic et al, 2001;Salnikov et al, 2003;Heldin et al, 2004;Thongchot et al, 2014).…”