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Current therapeutic options for intrahepatic cholangiocarcinoma (ICC) are very limited, which is largely attributed to poor understanding of molecular pathogenesis of ICC. Breast cancer type 1 susceptibility protein-associated protein-1 (BAP1) has been reported to be a broad-spectrum tumor suppressor in many tumor types, yet its role in ICC remains unknown. The aim of this study was to investigate the clinical implications and biological function of BAP1 in ICC. Our results showed that the messenger RNA and protein levels of BAP1 were significantly downregulated in ICC versus paired non-tumor tissues. Overexpression of wild-type but not mutant BAP1 significantly suppressed ICC cell proliferation, cell cycle progression, and invasion in vitro, as well as tumor progression in vivo. Conversely, knockdown of BAP1 yielded opposing effects. Mechanistically, BAP1 functioned as a tumor suppressor in ICC by inhibiting the extracellular signal-regulated kinase 1/2 and c-Jun N-terminal kinase/c-Jun pathways, and this function was abolished by inactivating mutations. Clinically, low BAP1 expression was positively correlated with aggressive tumor characteristics, such as larger tumor size, presence of lymphatic metastasis, and advanced tumor node metastasis stage. Survival analysis revealed that low BAP1 expression was significantly and independently associated with poor overall survival and relapse-free survival after curative surgery. In conclusion, BAP1 is a putative tumor suppressor of ICC, and may serve as a valuable prognostic biomarker as well as potential therapeutic target for ICC.

Background and aimStudies suggest that antiviral therapy performed after curative resection improves the postoperative prognosis of hepatitis B virus (HBV)-related hepatocellular carcinoma (HCC), but the evidence has been contradictory. The aim of this meta-analysis was to assess the effect of antiviral therapy with nucleoside analogs (NAs) after curative resection on the long-term postoperative survival of patients with HBV-related HCC.Materials and methodsMEDLINE, PubMed, Embase, and Cochrane Library were systematically searched up to August 2017 with no limits. Outcome measures were the primary parameter of overall survival (OS) after radical resection of HBV-related HCC and the secondary parameter of postoperative recurrence-free survival (RFS).ResultsA total of 9,009 patients (2,546 of whom received antiviral therapy and 6,463 received no treatment) were included. The pooled analysis revealed that antiviral therapy was associated with significantly improved OS (hazard ratio [HR]: 0.58; 95% confidence interval [CI]: 0.51–0.67; P<0.00001) and RFS (HR: 0.68; 95% CI: 0.63–0.74; P<0.00001). Moderate heterogeneity among studies for both OS and RFS was observed, which disappeared or decreased after pooling studies using one type of NA as antiviral drug. In the subgroup analysis, anti-viral therapy significantly prolonged both OS (HR: 0.69; 95% CI: 0.52–0.92; P=0.01) and RFS (HR: 0.58; 95% CI: 0.49–0.70; P<0.00001) in patients with high baseline HBV DNA level (≥20,000 IU/mL) with no heterogeneity, but not in patients with low baseline HBV DNA level (<20,000 IU/mL).ConclusionAntiviral therapy with NAs confers significant survival benefits in patients with HBV-related HCC after curative resection, especially in patients with high baseline HBV DNA level (≥20,000 IU/mL).

Accumulating evidence shows HOOK1 disordered in human malignancies. However, the clinicopathological and biological significance of HOOK1 in renal cell carcinoma (RCC) remains rarely studied. In this study, the authors demonstrate that HOOK1 is downregulated in RCC samples with predicted poorer clinical prognosis. Mechanistically, HOOK1 inhibits tumor growth and metastasis via canonical TGF-𝜷/ALK5/p-Smad3 and non-canonical TGF-𝜷/MEK/ERK/c-Myc pathway. At the same time, HOOK1 inhibits RCC angiogenesis and sunitinib resistance by promoting degradation of TNFSF13B through the ubiquitin-proteasome pathway. In addition, HOOK1 is transcriptionally regulated by nuclear factor E2F3 in VHL dependent manner. Notably, an agonist of HOOK1, meletin, is screened and it shows antitumor activity more effectively when combined with sunitinib or nivolumab than it is used alone. The findings reveal a pivotal role of HOOK1 in anti-cancer treatment, and identify a novel therapeutic strategy for renal cell carcinoma.