Sorafenib resistance is one of the main obstacles to the treatment of advanced/recurrent hepatocellular carcinoma (HCC). Here, sorafenib-resistant HCC cells and xenografts in nude mice were used as experimental models. A cohort of patients with advanced recurrent HCC who were receiving sorafenib therapy was used to assess the clinical significance of this therapy. Our data showed that 14-3-3η maintained sorafenib resistance in HCC. An analysis of the underlying molecular mechanisms revealed that 14-3-3η stabilizes hypoxia-inducible factor 1α (HIF-1α) through the inhibition of ubiquitin-dependent proteasome protein degradation, which leads to the maintenance of cancer stem cell (CSC) properties. We further found that microRNA-16 (miR-16) is a competent miRNA that reverses sorafenib resistance by targeting the 3′-UTR of 14-3-3η and thereby inhibits 14-3-3η/HIF-1α/CSC properties. In HCC patients, significant negative correlations were found between the expression of miR-16 and 14-3-3η, HIF-1α, or CSC properties. Further analysis showed that low miR-16 expression but high 14-3-3η expression can prognosticate sorafenib resistance and poor survival. Collectively, our present study indicated that miR-16/14-3-3η is involved in sorafenib resistance in HCC and that these two factors could be potential therapeutic targets and biomarkers for predicting the response to sorafenib treatment.

BackgroundMulti-drug resistance (MDR) is one of the main obstacles for treatment of advanced/recurrent hepatocellular carcinoma (HCC). We have previously identified arsenic trioxide (ATO) as an effective metastasis/angiogenesis inhibitor in HCC. Here, we further found that MDR-HCC cells were more sensitive to ATO.MethodsThe MDR-HCC cells were used as experimental models. Biological functions were investigated using cell transfection, polymerase chain reaction, western blot, southwestern blot, immunostaining, immunoprecipitation plus atomic fluorescence spectrometry, and so on.ResultsThe MDR-HCC cells underwent high oxidative stress condition, and employed adaptive mechanisms for them to survive; while ATO abolished such mechanisms via targeting the 14–3-3η/nuclear factor kappa B (NF-κB) feedback Loop. Briefly, in MDR cells, the increase of ROS activated NF-κB signaling, which transcriptionally activated 14–3-3η. Meanwhile, the activation of NF-κB can be constitutively maintained by 14–3-3η. As a NF-κB inhibitor, ATO transcriptionally inhibited the 14–3-3η mRNA level. Meanwhile, ATO was also validated to directly bind to 14–3-3η, enhancing the degradation of 14–3-3η protein in an ubiquitination-dependent manner. Knockdown of 14–3-3η reduced the ATO-induced reversal extents of drug resistance in MDR cells.Conclusion14–3-3η/NF-κB feedback loop plays an important role in maintaining the MDR phenotype in HCC. Moreover, via targeting such feedback loop, ATO could be considered as a potential molecular targeted agent for the treatment of HCC.Electronic supplementary materialThe online version of this article (10.1186/s13046-018-1005-y) contains supplementary material, which is available to authorized users.

BackgroundA variety of miRNAs have been recently reported to be abnormally expressed in colorectal cancer (CRC). A growing number of studies have demonstrated that aberrantly expressed miRNAs are closely related to the development and progression of CRC. It has been found that miR-140-3p plays a vital role in several cancers. However, its expression, roles and mechanisms in CRC are remain unknown.Materials and methodsReverse transcription-quantitative polymerase chain reaction (RT-qPCR) were used to determine miR-140-3p expression in CRC tissues and cell lines. CCK8, migration, invasion and flow cytometric assays were used to determine the influence of miR-140-3p upregulation on cell proliferation, migration, invasion and apoptosis of CRC cells. Luciferase reporter assays and Western blots were utilized to identify the target genes of miR-140-3p. In addition, the potential mechanism of miR-140-3p action in CRC cells was elucidated.ResultsIn our study, miR-140-3p expression was significantly decreased in CRC tissues and cell lines. Overexpression of miR-140-3p attenuated proliferation, migration, and invasion and induced the apoptosis of CRC cells. Bioinformatics analyse and luciferase reporter analysis identified PD-L1 as a putative target gene of miR-140-3p. PD-L1 was overexpressed in CRC tissues and inversely correlated with miR-140-3p expression. Suppression of PD-L1 expression in CRC cells generated biological behaviours in CRC cells that were similar to those observed after treated with miR-140-3p mimics. Restoration of PD-L1 expression partially attenuated the inhibitory effect of miR-140-3p on CRC cells. Western blot were used to verify the effect of PD-L1 expression on PI3K/AKT pathway. In addition, overexpression of miR-140-3p could inhibit CRC tumor growth in vivo.ConclusionIn general, these data demonstrate that miR-140-3p acts as a tumour suppressor in CRC by directly targeting PD-L1 and inactivating PI3K/AKT pathway, suggesting that miR-140-3p might be a novel target for CRC diagnosis and treatment.

T cells expressing chimeric antigen receptors, especially CD19 CAR-T cells have exhibited effective antitumor activities in B cell malignancies, but due to several factors such as antigen escape effects and tumor microenvironment, their curative potential in hepatocellular carcinoma has not been encouraging. To reduce the antigen escape risk of hepatocellular carcinoma, this study was to design and construct a bispecific CAR targeting c-Met and PD-L1. c-Met/PD-L1 CAR-T cells were obtained by lentiviral transfection, and the transfection efficiency was monitored by flow cytometry analysis. LDH release assays were used to elucidate the efficacy of c-Met/PD-L1 CAR-T cells on hepatocellular carcinoma cells. In addition, xenograft models bearing human hepatocellular carcinoma were constructed to detect the antitumor effect of c-Met/PD-L1 CAR-T cells in vivo. The results shown that this bispecific CAR was manufactured successfully, T cells modified with this bispecific CAR demonstrated improved antitumor activities against c-Met and PD-L1 positive hepatocellular carcinoma cells when compared with those of monovalent c-Met CAR-T cells or PD-L1 CAR-T cells but shown no distinct cytotoxicity on hepatocytes in vitro. In vivo experiments shown that c-Met/PD-L1 CAR-T cells significantly inhibited tumor growth and improve survival persistence compared with other groups. These results suggested that the design of single-chain, bi-specific c-Met/PD-L1 CAR-T is more effective than that of monovalent c-Met CAR-T for the treatment of hepatocellular carcinoma., and this bi-specific c-Met/PD-L1 CAR is rational and implementable with current T-cell engineering technology.