Autophagy activity in cholangiocarcinoma is associated with anatomical localization of the tumor

Preclinical evidence for preventive and curative effects of resveratrol on xenograft cholangiocarcinogenesis

Cholangiocarcinoma (CCA), the malignant tumor of bile duct epithelial cells, is a relatively rare yet highly lethal cancer. In this work, we tested the ability of Resveratrol (RV) to prevent and cure CCA xenograft in nude mice and investigated molecular mechanisms underpinning such anticancer effect. Human CCA cells were xenografted in mice that were or not treated prior to or after to transplantation with RV. Tumor growth was monitored and analyzed for the markers of cell proliferation, apoptosis, and autophagy. TCGA was interrogated for the molecules possibly targeted by RV. RV could inhibit the growth of human CCA xenograft when administered after implantation and could reduce the growth or even impair the implantation of the tumors when administered prior the transplantation. RV inhibited CCA cell proliferation, induced apoptosis with autophagy, and strongly reduced the presence of CAFs and production of IL-6. Interrogation of CCA dataset in TCGA database revealed that the expression of IL-6 Receptor (IL-6R) inversely correlated with that of MAP-LC3 and BECLIN-1, and that low expression of IL-6R and of MIK67, two pathways downregulated by RV, associated with better survival of CCA patients. Our data demonstrate that RV elicits a strong preventive and curative anticancer effect in CCA by limiting the formation of CAFs and their release of IL-6, and this results in up-regulation of autophagy and apoptosis in the cancer cells. These findings support the clinical use of RV as a primary line of prevention in patients exposed at risk and as an adjuvant therapeutics in CCA patients.

Autophagy impairment in human bile duct carcinoma cells

Bile duct epithelial cells, named cholangiocytes, may undergo a neoplastic transformation leading to cholangiocarcinoma. The role autophagy plays in cancer is still debated and few information are available in cholangiocarcinoma. We report in vitro data, at least in part validated in vivo,i ndicating that autophagy is impaired in intrahepatic cholangiocarcinoma cells, as compared to healthy cholangiocytes, evaluated through LC3II and p62 Western blot analyses. Autophagy impairment was found to be associated with low expression of TFEB protein and high expression of three proteins i.e., c-FLIP, caspase-10 and cleaved BCLAF-1, as compared to healthy cholangiocytes. We highlight biological effects of autophagy impairment in cholangiocarcinoma showing that autophagy induction, via rapamycin, as well as caspase inhibition, via Q-VD-OPh, are able to reduce proliferation marker PCNA level, colony size and protein content of cultured cholangiocarcinoma cells. The increased protein expression of p62, c-FLIP, caspase-10 observed in vitro in cholangiocarcinoma cells was paralleled by significant increase at gene expression levels in vivo; in fact, significant increase of transcript levels of p62, c-FLIP and caspase-10 was observed in 34 biopsies from human cholangiocarcinoma patients compared to 9 biopsies from 9 healthy controls, as reported in the GEPIA2 public database. The significant increase of p62 level in cholangiocarcinoma was found as a relatively uncommon finding in solid cancers, since it was also found in only 7 cancer types out of 31 cancer types investigated, including melanoma and hepatocarcinoma. In conclusion, we present data suggesting a molecular machinery controlling autophagy in cholangiocytes and autophagy impairment in cholangiocarcinoma.

COTE1 Facilitates Intrahepatic Cholangiocarcinoma Progression via Beclin1-Dependent Autophagy Inhibition

COTE1 was recently described as an oncogene in hepatocellular carcinoma and gastric cancer. However, the roles of COTE1 in intrahepatic cholangiocarcinoma (ICC) are little known. Our study is aimed at clarifying novel functions of COTE1 in ICC progression, including proliferation, invasion, and autophagy. By using quantitative real-time PCR, immunohistochemistry staining, and western blotting, we found that COTE1 expression was frequently upregulated in ICC tissues, compared to paracarcinoma tissues. High COTE1 expression was significantly correlated with aggressive clinical features and predicted poor prognosis of ICC patients. Functional experiments revealed that ectopic COTE1 expression promoted ICC cell proliferation, colony formation, cellular invasion, migration, and in vivo tumorigenicity; in contrast, COTE1 knockdown resulted in the opposite effects. At molecular mechanism in vitro and vivo, our study revealed that COTE1 overexpression suppressed autophagy via Beclin1 transcription inhibition; conversely, COTE1 silencing facilitated autophagy through promoting Beclin1 expression. Furthermore, the suppression of COTE1 knockdown on cellular growth and invasion was rescued/aggravated by Beclin1 inhibition/accumulation. Our data, for the first time, illustrate that COTE1 is an oncogene in ICC pathogenesis, and the ectopic COTE1 expression promotes ICC proliferation and invasion via Beclin1-dependent autophagy inhibition.

Active Autophagy Is Associated with Favorable Outcome in Patients with Surgically Resected Cholangiocarcinoma

Data on the impact of autophagy in primary cholangiocarcinoma (CCA) remain scarce. Here, we therefore investigated the role of active autophagy and its impact on survival in CCA patients. All CCA patients who underwent surgical resection with curative intent between 08/2005 and 12/2021 at University Hospital Frankfurt were evaluated. Autophagic key proteins were studied by immunohistochemistry. iCCA processed for gene expression profiling of immune-exhaustion gene sets was used for an autophagy approach in silico. Active autophagy was present in 23.3% of the 172 CCA patients. Kaplan-Meier curves revealed median OS of 68.4 months (95% CI = 46.9-89.9 months) and 32.7 months (95% CI = 23.6-41.8 months) for active and non-active autophagy, respectively (p ≤ 0.001). In multivariate analysis, absence of active autophagy (HR = 2, 95% CI = 1.1-3.5, p = 0.015) was an independent risk factor for OS. Differential-expression profiling revealed significantly upregulated histone deacetylases (HDAC) mRNA in patients showing non-active autophagy. In line with this, pan-acetylated lysine was significantly more prominent in CCA patients with ongoing autophagy (p = 0.005). Our findings strengthen the role of active autophagy as a prognostically relevant marker and a potential therapeutic target.

Histone Deacetylase Inhibition and Autophagy Modulation Induces a Synergistic Antiproliferative Effect and Cell Death in Cholangiocarcinoma Cells

Cholangiocarcinoma, also known as biliary tract cancer, is an aggressive adenocarcinoma arising from epithelial cells lining the intra- and extrahepatic biliary system. The effects of autophagy modulators and histone deacetylase (HDAC) inhibitors in cholangiocarcinoma are not fully known. It is essential to understand the molecular mechanisms and the effects of HDAC inhibitors in the context of cholangiocarcinoma. The antiproliferative effect of different HDAC inhibitors and autophagy modulation was investigated by the MTT cell viability assay in TFK-1 and EGI-1 cholangiocarcinoma cell lines. Combination indexes were calculated using CompuSyn software. Consequently, apoptosis was detected by Annexin V/PI staining. The effect of the drugs on the cell cycle was measured by the propidium iodide staining. The HDAC inhibition was confirmed via acetylated histone protein levels by western blotting. HDAC inhibitors, MS-275 and romidepsin, showed a better synergistic effect with the nocodazole combination. The combination treatment exerted its growth inhibitory effect by cell cycle arrest and induction of apoptosis. The cell cycle analysis of the combination treatment showed that the S phase and G2/M phase were achieved. Moreover, the necrotic and apoptotic cell population increased after single HDAC inhibitors and combination treatment. The anti-cancer effect of HDAC inhibitors is revealed by acetylation levels of histones. While acetylation levels were increased in response to HDAC inhibitors and autophagy modulator combinations, the HDAC expression decreased. This study highlights the importance of the combination of HDAC inhibition and autophagy modulators and demonstrates a synergistic effect, which could be a promising therapy and novel treatment approach for cholangiocarcinoma.

Hydroxychloroquine Induces Apoptosis in Cholangiocarcinoma via Reactive Oxygen Species Accumulation Induced by Autophagy Inhibition

Purpose: Despite considerable efforts to improve treatment modalities for cholangiocarcinoma, a common form of malignant tumor, its long-term survival rate remains poor. Hydroxychloroquine (HCQ) is a 4-aminoquinoline derivative antimalarial drug that has antimalarial and autophagy inhibition effects and exhibits comprehensive therapeutic effects on various cancers. In this study, we aimed to explore the anticancer potential and the underlying molecular mechanism of HCQ in cholangiocarcinoma treatment in vitro and in vivo. Methods: Autophagy-related genes (ARGs) were obtained from the Human Autophagy Database and Molecular Signatures Database, and the expression profiles of ARGs were downloaded from the database of The Cancer Genome Atlas. Different expression gene sets were performed using R software. The Gene Ontology and KEGG enrichment analyses were performed to reveal significantly enriched signaling pathways and to identify differentially expressed genes in cholangiocarcinoma tissues. HuCCT-1 and CCLP-1 cells were exposed to different concentrations of HCQ. Cell proliferation was detected by Cell Counting Kit-8 (CCK-8), colony formation, and 5-ethynyl-2'-deoxyuridine (EdU) assays. Cell apoptosis and cycle arrest were detected by the Live/Dead cell assay and flow cytometry (FCM). The inhibition of autophagy was observed using fluorescence microscopy. The reactive oxygen species levels were assessed by fluorescence microscopy and flow cytometry. The protein levels were determined by western blot. A cholangiocarcinoma cell line xenograft model was used to evaluate the antitumor activity of HCQ in vivo. Results: Compared with normal tissues, there were 141 ARGs with an aberrant expression in cholangiocarcinoma tissues which were mainly enriched in autophagy-related processes. Inhibition of autophagy by HCQ effectively suppressed cholangiocarcinoma in vitro and in vivo. HCQ inhibited cell proliferation and induced apoptosis and cycle arrest in vitro by increasing ROS accumulation, which was involved in autophagy inhibition. The ROS scavenger reduced l-glutathione distinctly weakened HCQ-induced cell apoptosis and viability inhibition in cholangiocarcinoma cells. In addition, HCQ inhibited growth of cholangiocarcinoma cell line xenograft tumors. Conclusion: HCQ could inhibit cell proliferation and induce apoptosis in cholangiocarcinoma by triggering ROS accumulation via autophagy inhibition, which makes HCQ a potential antitumor drug candidate for cholangiocarcinoma treatment.