The role of adjuvant transcatheter arterial chemoembolization following repeated curative resection/ablation for hepatocellular carcinoma with early recurrence: a propensity score matching analysis.

BACKGROUND: The role of adjuvant transcatheter arterial chemoembolization (TACE) following repeated resection/ablation for recurrent hepatocellular carcinoma (HCC) remains uncertain. The aim of this study was to assess the effectiveness of adjuvant TACE following repeated resection or ablation in patients with early recurrent HCC. METHODS: Information for patients who underwent repeated surgery or radiofrequency ablation (RFA) for early recurrent HCCs (< 2 years) at our institution from January 2017 to December 2020 were collected. Patients were divided into adjuvant TACE and observation groups according to whether they received adjuvant TACE or not. The recurrence-free survival (RFS) and overall survival (OS) were compared between the two groups before and after propensity score matching (PSM). RESULTS: Of the 225 patients enrolled, the median time of HCC recurrence was 11 months (IQR, 6-16 months). After repeated surgery or radiofrequency ablation (RFA) for recurrent tumors, 45 patients (20%) received adjuvant TACE while the remaining 180 (80%) didn't. There were no significant differences in RFS (P = 0.325) and OS (P = 0.072) between adjuvant TACE and observation groups before PSM. There were also no significant differences in RFS (P = 0.897) and OS (P = 0.090) between the two groups after PSM. Multivariable analysis suggested that multiple tumors, liver cirrhosis, and RFA were independent risk factors for the re-recurrence of HCC. CONCLUSION: Adjuvant TACE after repeated resection or ablation for early recurrent HCCs was not associated with a long-term survival benefit in this single-center cohort.

lncRNA-POIR promotes epithelial-mesenchymal transition and suppresses sorafenib sensitivity simultaneously in hepatocellular carcinoma by sponging miR-182-5p.

Sorafenib (SOR) resistance remains a major obstacle in the effective treatment of hepatocellular carcinoma (HCC). A number of long noncoding RNAs (lncRNAs) are responsible for this chemoresistance. This study aimed to reveal the essential function of a recently defined lncRNA, lncRNA-POIR, in the epithelial-mesenchymal transition (EMT) and SOR sensitivity of HCC cells. SOR-induced cytotoxicity was analyzed via cell counting kit-8 and ethynyl-2'-deoxyuridine incorporation assays, whereas immunoblotting and confocal immunofluorescence were used to determine the expression levels of EMT markers. Furthermore, loss- or gain-of-function approaches were used to demonstrate the role of lncRNA-POIR/miR-182-5p on EMT and SOR sensitivity in HCC. The direct interaction between lncRNA-POIR and miR-182-5p was verified using a luciferase reporter assay. We found that knockdown of lncRNA-POIR sensitized HCC cells to SOR and simultaneously reversed EMT. As expected, miR-182-5p was confirmed as the downstream target of lncRNA-POIR. Moreover, miR-182-5p overexpression clearly reversed EMT and promoted SOR-induced cytotoxicity in representative HCC cells, whereas miR-182-5p downregulation played a contrasting role; miR-182-5p knockdown abolished the modulatory effects of lncRNA-POIR siRNA on EMT and SOR sensitivity. Together, these pieces of data suggest that lncRNA-POIR promotes EMT progression and suppresses SOR sensitivity simultaneously by sponging miR-182-5p. Thus, we proposed a compelling rationale for the use of lncRNA-POIR as a promising predictor of SOR response and as a potential therapeutic target for HCC treatment in the future.

Carcinosarcoma of the pancreas: comprehensive clinicopathological and molecular characterization.

BACKGROUND: Carcinosarcoma of pancreas is a rare subtype of pancreatic cancer. The aim of this study was to comprehensively elaborate the clinicopathological and molecular features of this rare malignancy. METHODS: Patients who were diagnosed with carcinosarcoma of the pancreas were retrospectively identified from pathology database of a single institution between 2012 and 2018. RESULTS: A total of nine patients were identified. Pathological examination of tumor tissues from included patients showed coexisting carcinomatous and sarcomatous components. These two components were distinguished by mutually exclusive expression of cytokeratin and vimentin. The sarcomatous tissue exhibited more extensive proliferation, as revealed by Ki67 staining, and necrosis compared with the carcinomatous counterpart. Genomic analysis of tumor tissues for two patients demonstrated hotspot mutation at KRAS and TP53. Carcinomatous and sarcomatous components were separately obtained via laser captured microdissection in one patient, and mutations of driving genes were highly concordant between them. Besides, immunostaining of frequently-altered tumor suppressor genes for these two components suggested consistent expression patterns. The median overall survival for six patients with adequate follow-up was 14 months. CONCLUSION: Carcinosarcoma of the pancreas represent a rare malignancy with distinct histological characteristics. Genomic and molecular analysis suggested monoclonal origin of carcinomatous and sarcomatous components.

Decreased expression of H19/miR-675 ameliorates hypoxia-induced oxaliplatin resistance in colorectal cancer.

Hypoxic microenvironment, a hallmark of solid tumors, contributes to chemoresistance, and long noncoding (lnc) RNAs are involved in hypoxia-induced drug resistance. However, the role of lncRNAs in hypoxic tumor chemotherapy resistance remains unclear. Here, we aimed to elucidate the effects of lncRNAs in hypoxia-mediated resistance in colorectal cancer (CRC), as well as the underlying mechanisms. The results indicated that the expression of lncRNA H19 was enhanced in hypoxia- or oxaliplatin-treated CRC cells; moreover, H19 contributed to drug resistance in CRC cells both in vitro and in vivo. Mechanistically, H19 was noted to act as a competitive endogenous RNA of miR-675-3p to regulate epithelial-mesenchymal transition (EMT). Notably, an miR-675-3p mimic could attenuate the effects of H19 deficiency in CRC cells with hypoxia-induced chemoresistance. In conclusion, H19 downregulation may counteract hypoxia-induced chemoresistance by sponging miR-675-3p to regulate EMT; as such, the H19/miR-675-3p axis might be a promising therapeutic target for drug resistance in CRC.

G protein-coupled estrogen receptor deficiency accelerates liver tumorigenesis by enhancing inflammation and fibrosis.

G protein-coupled estrogen receptor (GPER) is a novel estrogen-binding receptor involved in many pathological conditions, including cancer. In this study, we investigated the effect of GPER on hepatocellular carcinoma (HCC). Our data show GPER knockout in a diethylnitrosamine (DEN)-induced mouse tumor model significantly accelerated liver tumorigenesis, accompanied by enhanced immune cell infiltration, fibrosis, and the production of inflammatory factors, such as interleukin-6 (IL-6). We further delineated the function of GPER in macrophages and hepatic stellate cells (HSCs). Treatment with the selective GPER agonist, G-1, decreased the expression of IL-6 in bone marrow-derived macrophages, which was abrogated upon deficiency of GPER. In a HSC line (LX2), G-1 treatment downregulated the expression of α-smooth muscle actin. In addition, both GPER mRNA and protein levels were significantly lower in HCC compared with matched non-tumor tissues. However, modulating GPER expression did not affect the viability and proliferation of hepatoma cells in vitro. Together our results indicate that GPER protects against HCC tumorigenesis through regulating inflammatory responses rather than directly acting on tumor cells. Therefore, GPER activation may be a potential strategy for prevention and treatment of HCC.

ARK5 promotes doxorubicin resistance in hepatocellular carcinoma via epithelial-mesenchymal transition.

AMP-activated protein kinase family member 5 (ARK5) overexpression has been reported in many human cancers, and ARK5 is associated with poor prognosis in hepatocellular carcinoma (HCC). However, whether ARK5 is involved in HCC chemoresistance is unclear. The present study aimed to investigate the role of ARK5 in HCC chemoresistance and the underlying mechanism. In this study, we found that SNU387 and SNU449 HCC cell lines overexpressing ARK5 displayed low doxorubicin sensitivity compared to Huh7 and Hep3B HCC cell lines with ARK5 low-expression. And knockdown of ARK5 increased the doxorubicin sensitivity in all HCC cell lines in the manner of inhibiting cell proliferation. Western blotting and immunofluorescence both showed that ARK5 knockdown upregulated E-cadherin and downregulated vimentin, which was consistent with the knockdown of TWIST, indicating ARK5 was involved in epithelial-mesenchymal transition (EMT). Moreover, suppressing ARK5 by siRNA restored E-cadherin and vimentin expression induced by doxorubicin treatment or hypoxia culture. Our results indicated ARK5 confers doxorubicin resistance in HCC via inducing EMT.

OSI-027 inhibits pancreatic ductal adenocarcinoma cell proliferation and enhances the therapeutic effect of gemcitabine both in vitro and in vivo.

Despite its relative rarity, pancreatic ductal adenocarcinoma (PDAC) accounts for a large percentage of cancer deaths. In this study, we investigated the in vitro efficacy of OSI-027, a selective inhibitor of mammalian target of rapamycin complex 1 (mTORC1) and mTORC2, to treat PDAC cell lines alone, and in combination with gemcitabine (GEM). Similarly, we tested the efficacy of these two compounds in a xenograft mouse model of PDAC. OSI-027 significantly arrested cell cycle in G0/G1 phase, inhibited the proliferation of Panc-1, BxPC-3, and CFPAC-1 cells, and downregulated mTORC1, mTORC2, phospho-Akt, phospho-p70S6K, phospho-4E-BP1, cyclin D1, and cyclin-dependent kinase 4 (CDK4) in these cells. Moreover, OSI-027 also downregulated multidrug resistance (MDR)-1, which has been implicated in chemotherapy resistance in PDAC cells and enhanced apoptosis induced by GEM in the three PDAC cell lines. When combined, OSI-027 with GEM showed synergistic cytotoxic effects both in vitro and in vivo. This is the first evidence of the efficacy of OSI-027 in PDAC and may provide the groundwork for a new clinical PDAC therapy.

WP1130 increases doxorubicin sensitivity in hepatocellular carcinoma cells through usp9x-dependent p53 degradation.

Resistance to chemotherapeutic drugs is a major obstacle in hepatocellular carcinoma (HCC) therapy. However, the underlying mechanisms are not well understood. Recent evidence suggests that deubiquitinases (DUB) are key regulators in the mechanisms of cell proliferation, apoptosis and chemoresistance. The present study aimed to investigate whether WP1130, which inhibits activity of deubiquitinases, exerts synergistic cytotoxicity with doxorubicin in HCC and the underlying mechanisms. In the study, we found that Huh7, HepG2, and SNU387 HCC cells with p53 expression displayed enhanced response to the combination therapy compared with p53-deficient HCC cells (Hep3B) in the manner of inhibiting cell proliferation. Downregulation of p53 abolished the synergistic cytotoxicity of doxorubicin and WP1130 on HCC cells. Mechanistically, we found that combined treatment with WP1130 suppressed doxorubicin-mediated upregulation of p53 via promoting its ubiquitin-proteasome dependent degradation, whereas knockdown of DUB usp9x abolished this effect. Taken together, these results demonstrate that combined treatment with WP1130 sensitized HCC cells to doxorubicin via usp9x-depedent p53 degradation.

Inhibition of mTORC2 Induces Cell-Cycle Arrest and Enhances the Cytotoxicity of Doxorubicin by Suppressing MDR1 Expression in HCC Cells.

mTOR is aberrantly activated in hepatocellular carcinoma (HCC) and plays pivotal roles in tumorigenesis and chemoresistance. Rapamycin has been reported to exert antitumor activity in HCC and sensitizes HCC cells to cytotoxic agents. However, due to feedback activation of AKT after mTOR complex 1 (mTORC1) inhibition, simultaneous targeting of mTORC1/2 may be more effective. In this study, we examined the interaction between the dual mTORC1/2 inhibitor OSI-027 and doxorubicin in vitro and in vivo. OSI-027 was found to reduce phosphorylation of both mTORC1 and mTORC2 substrates, including 4E-BP1, p70S6K, and AKT (Ser473), and inhibit HCC cell proliferation. Similar to OSI-027 treatment, knockdown of mTORC2 induced G0-G1 phase cell-cycle arrest. In contrast, rapamycin or knockdown of mTORC1 increased phosphorylation of AKT (Ser473), yet had little antiproliferative effect. Notably, OSI-027 synergized with doxorubicin for the antiproliferative efficacy in a manner dependent of MDR1 expression in HCC cells. The synergistic antitumor effect of OSI-027 and doxorubicin was also observed in a HCC xenograft mouse model. Moreover, AKT was required for OSI-027-induced cell-cycle arrest and downregulation of MDR1. Our findings provide a rationale for dual mTORC1/mTORC2 inhibitors, such as OSI-027, as monotherapy or in combination with cytotoxic agents to treat HCC. Mol Cancer Ther; 14(8); 1805-15. ©2015 AACR.