Torin2 overcomes sorafenib resistance via suppressing mTORC2-AKT-BAD pathway in hepatocellular carcinoma cells.

BACKGROUND: Sorafenib is an oral multi-kinase inhibitor that was approved by the US Food and Drug Administration for the treatment of patients with advanced hepatocellular carcinoma (HCC). However, resistance to sorafenib is an urgent problem to be resolved to improve the therapeutic efficacy of sorafenib. As the activation of AKT/mTOR played a pivotal role in sorafenib resistance, we evaluated the effect of a dual mTOR complex 1/2 inhibitor Torin2 on overcoming the sorafenib resistance in HCC cells. METHODS: The sorafenib-resistant Huh7 and Hep3B cell lines were established from their parental cell lines. The synergistic effect of sorafenib and Torin2 on these cells was measured by cell viability assay and quantified using the Chou-Talalay method. Apoptosis induced by the combination of sorafenib and Torin2 and the alteration in the specific signaling pathways of interest were detected by Western blotting. RESULTS: Sorafenib treatment inversely inhibited AKT in parental but activated AKT in sorafenib-resistant Huh7 and Hep3B HCC cells, which underscores the significance of AKT activation. Torin2 and sorafenib synergistically suppressed the viability of sorafenib-resistant cells via apoptosis induction. Torin2 successfully suppressed the sorafenib-activated mTORC2-AKT axis, leading to the dephosphorylation of Ser136 in BAD protein, and increased the expression of total BAD, which contributed to the apoptosis in sorafenib-resistant HCC cells. CONCLUSIONS: In this study, Torin2 and sorafenib showed synergistic cytostatic capacity in sorafenib-resistant HCC cells, via the suppression of mTORC2-AKT-BAD pathway. Our results suggest a novel strategy of drug combination for overcoming sorafenib resistance in HCC.

Impact of treatment modalities on patients with recurrent hepatocellular carcinoma after liver transplantation: Preliminary experience.

BACKGROUND: Post-liver transplantation (LT) hepatocellular carcinoma (HCC) recurrence still occurs in approximately 20% of patients and drastically affects their survival. This study aimed to evaluate the efficacy of various treatments for recurrent HCC after LT in a Chinese population. METHODS: A total of 64 HCC patients with tumor recurrence after LT were enrolled in this study. Univariate and multivariate analyses were performed to identify factors affecting post-recurrence survival. RESULTS: Of the 64 patients with recurrent HCC after LT, those who received radical resection followed by nonsurgical therapy had a median overall survival (OS) of 20.9 months after HCC recurrence, significantly superior to patients who received only nonsurgical therapy (9.4 months) or best supportive care (2.4 months). The one- and two-year OS following recurrence was favorable for patients receiving radical resection followed by nonsurgical therapy (93.8%, 52.6%), poor for patients receiving only nonsurgical therapy (30.8%, 10.8%), and dismal for patients receiving best supportive care (0%, 0%; overall P < 0.001). Median OS in sorafenib-tolerant patients treated with lenvatinib was 19.5 months, far surpassing the patients that discontinued sorafenib or were treated with regorafenib after sorafenib failure (12 months, P < 0.001). Compared with tacrolimus-based immunosuppressive therapy, OS was significantly increased with sirolimus-based therapy at one and two years after HCC recurrence (P = 0.035). Multivariate analysis showed radical resection combined with nonsurgical therapy for recurrent HCC and sorafenib-lenvatinib sequential therapy were independent favorable factors for post-recurrence survival. CONCLUSIONS: Aggressive surgical intervention in well-selected patients significantly improves OS after recurrence. A multidisciplinary treatment approach is required to slow down disease progression for patients with unresectable recurrent HCC.

Multidisciplinary Treatment of Advanced Hepatocellular Carcinoma.

Current strategy for treatment of hepatocellular carcinoma (HCC) based on Barcelona-Clinic Liver Cancer (BCLC) criteria dictates that patients with advanced-stage HCC are to only receive treatment with tyrosine kinase inhibitors. However, they prolong overall survival just by slightly more than 6 months. In this article, we present a patient with HCC diagnosed at an advanced stage who received multidisciplinary treatment consisting of transarterial chemoembolization, hepatic resection, pulmonary resection, radiofrequency ablation, tyrosine kinase inhibitors, and radiotherapy, and has survived for more than 2 years since diagnosis and counting.

Th17 promotes acute rejection following liver transplantation in rats.

T help cell 17 (Th17), recently identified as a new subset of CD4(+) T cells, has been implicated in autoimmune diseases, tumor immunity, and transplant rejection. To investigate the role of Th17 in acute hepatic rejection, a rat model of allogeneic liver transplantation (Dark Agouti (DA) to Brown Norway (BN)) was established and isogeneic liver transplantation (BN to BN) was used as controls in the study. The expression of Th17-related cytokines in the liver and peripheral blood was determined by immunohistochemistry, flow cytometry, enzyme-linked immunosorbent assay (ELISA), or real-time quantitative reverse transcription polymerase chain reaction (RT-qPCR). Strong expression of interleukin-17A (IL-17A), IL-6, transforming growth factor-ß (TGF-ß), IL-8, and myeloperoxidase (MPO) was observed in liver allografts. The ratios of Th17 to CD4(+) lymphocytes in the liver and peripheral blood were dramatically increased in the allograft group compared with the control (P<0.01). Secreted IL-17 and IL-6 in liver homogenate and serum were significantly elevated in the allograft group, while secreted TGF-ß was increased in liver homogenate and decreased in serum compared with the control (P<0.01). The messenger RNA (mRNA) levels of IL-17, IL-21, and IL-23 were enhanced in the allografts compared with the control (P<0.01). Correlation analysis showed significant correlations between IL-17 and IL-6 and TGF-ß and between IL-17 and IL-21 and IL-23. The present study demonstrates that Th17 plays a role in promoting rat liver allograft rejection.

The impact of miR-34a on protein output in hepatocellular carcinoma HepG2 cells.

MicroRNAs are small non-coding RNA molecules that play essential roles in biological processes ranging from cell cycle to cell migration and invasion. Accumulating evidence suggests that miR-34a, as a key mediator of p53 tumor suppression, is aberrantly expressed in human cancers. In the present study, we aimed to explore the precise biological role of miR-34a and the global protein changes in HCC cell line HepG2 cells transiently transfected with miR-34a. Transfection of miR-34a into HepG2 cells caused suppression of cell proliferation, inhibition of cell migration and invasion. It also induced an accumulation of HepG2 cells in G1 phase. Among 116 protein spots with differential expression separated by 2-DE method, 34 proteins were successfully identified by MALDI-TOF/TOF analysis. Of these, 15 downregulated proteins may be downstream targets of miR-34a. Bioinformatics analysis produced a protein-protein interaction network, which revealed that the p53 signaling pathway and cell cycle pathway were two major hubs containing most of the proteins regulated by miR-34a. Cytoskeletal proteins such as LMNA, GFAP, MACF1, ALDH2, and LOC100129335 are potential targets of miR-34a. In conclusion, abrogation of miR-34a function could cause downstream molecules to switch on or off, leading to HCC development.