Chemoresistance In Hepatocellular Carcinoma Research Articles

MicroRNA-361-5p induces hepatocellular carcinoma cell apoptosis and enhances drug sensitivity by targeting MAP3K9.

MicroRNAs (miRs) participate in the development of several cancers. miR-361-5p suppresses the proliferation of hepatocellular carcinoma (HCC) cells. However, its function and potential underlying mechanism of action in the chemoresistance of HCC remains unknown. Therefore, cisplatin (DDP)-resistant HCC cells were used to study the role and potential mechanism of action of miR-361-5p in HCC resistance to chemotherapy. TargetScan software and dual-luciferase reporter assays were used to determine whether MAPK kinase kinase 9 (MAP3K9) is a target gene of miR-361-5p. Subsequently, reverse transcription-quantitative PCR and western blot analyses demonstrated that miR-361-5p mimic decreased MAP3K9 expression levels in Huh7 cells and this change was reversed by transfection with the MAP3K9-plasmid. In addition, compared with THLE-2 cells, miR-361-5p was downregulated, while MAP3K9 was upregulated in Huh7 cells. MAP3K9 also reversed the miR-361-5p-induced HCC cell apoptosis. A DDP-resistant cell line, Huh7/DDP, was established and MTT analysis revealed that the IC50 value of DDP treatment in Huh7/DDP cells was higher compared with that in Huh7 cells. miR-361-5p expression was lower in Huh7/DDP cells compared with that in Huh7 cells. Similarly, miR-361-5p downregulated the expression levels of MAP3K9 in Huh7/DDP cells. Furthermore, MAP3K9 reversed miR-361-5p-induced sensitivity of Huh7/DDP cells to DDP and miR-361-5p induced Huh7/DDP cell apoptosis. Therefore, the findings of the present study demonstrated that the miR-361-5p/MAP3K9 axis may serve as a new potential biomarker and therapeutic target for DDP-resistant HCC.

Shc3 promotes hepatocellular carcinoma stemness and drug resistance by interacting with \u03b2-catenin to inhibit its ubiquitin degradation pathway

Hepatocellular carcinoma (HCC) is one of the most common cancers with an insidious onset, strong invasiveness, insensitivity to chemotherapy, and poor prognosis, thus makes clinical treatment challenging. The mechanisms require further elucidation for developing novel therapies and targeting drug resistance. Here, we observed high Shc3 expression in patients with chemoresistant and recurrent HCCs. Shc3 overexpression induced a significant increase in MDR1/P-glycoprotein expression, whereas Shc3 knockdown impaired this expression. Further, Shc3 inhibition significantly restored HCC cell sensitivity to doxorubicin and sorafenib. Mechanistically, Shc3 interacted with β-catenin, inhibited destruction complex stability, promoted β-catenin release, and dampened β-catenin ubiquitination. Shc3 bound β-catenin and facilitated its nuclear translocation, prompting the β-catenin/TCF pathway to elevate MDR1 transcription. β-catenin blockage abolished the discrepancy in drug resistance between Shc3-depleted HCC cells and control cells, which further validating that β-catenin is required for Shc3-mediated liver chemotherapy. We also determined the effect of Shc3 on the sensitivity of HCC to chemotherapy in vivo. Collectively, this study provides a potential strategy to target these pathways concurrently with systemic chemotherapy that can improve the clinical treatment of HCC.

TRIM37 overexpression is associated with chemoresistance in hepatocellular carcinoma via activating the AKT signaling pathway.

Hepatocellular carcinoma (HCC) is the most common primary liver cancer in the worldwide. Sorafenib is approved for first-line therapy against advanced HCC, but chemo-resistance is still a leading cause of tumor relapse and treatment failure in HCC. Thus, there is a significant clinical need to identify effective strategies to overcome drug resistance on the disease. The protein and mRNA expression of TRIM37 in HCC cell lines and patient tissues were determined using Real-time PCR and Western blot, respectively. HCC tissue samples were analyzed by IHC to investigate the association between TRIM37expression and the clinicopathological characteristics of HCC patients. Functional assays, such as MTT, FACS, and Tunel assay, are used to determine the oncogenic role of TRIM37 in human HCC progression. Furthermore, western blotting and luciferase assay were used to determine the mechanism of TRIM37promotes chemoresistance in HCC. We found that both the mRNA and protein expression of TRIM37 was markedly upregulated in HCC cell lines and tissues, especially in Sorafenib-resistance HCC tissues. Moreover, high TRIM37 expression was associated with poor prognosis with HCC patients. TRIM37 overexpression confers Sorafenib resistance on HCC cells; however, inhibition of TRIM37 sensitized HCC cell lines to Sorafenib cytotoxicity. Additionally, TRIM37 upregulated the levels of AKT activity and phosphorylated AKT, thereby activating canonical AKT signaling. Our findings suggest that targeting TRIM37 signaling may represent a promising strategy to enhance Sorafenib response in HCC patients with chemoresistant.

Paraspeckle Promotes Hepatocellular Carcinoma Immune Escape by Sequestering IFNGR1 mRNA.

Background & AimsHepatocellular carcinoma (HCC) is the most common type of hepatic malignancies, with poor prognosis and low survival rate. Paraspeckles, which are unique subnuclear structures, are recently found to be involved in the development of various tumors, including HCC, and are related to induction in chemoresistance of HCC. This study aimed to investigate the possibility of paraspeckle in HCC cells participating in immune escape and its underlying mechanism in vitro and in vivo.MethodsExpression of NEAT1_2, the framework of paraspeckle, in HCC cells and tissues was detected by qRT-PCR and RNA-FISH. mRNAs interacted with NEAT1_2 were pull-downed and sequenced in C-terminal S1-aptamer-tagged NEAT1_2 endogenously expressed HCC cells constructed using CRISPR-CAS9 knock-in technology. The effects of paraspeckle on HCC sensitivity to T-cell-mediated cytolysis were detected by T-cell mediated tumor cell killing assay. The roles of NEAT1_2 or NONO on IFNGR1 expression and IFN-γ signaling by applying gene function loss analysis in HCC cells were detected by qRT-PCR, RNA immunoprecipitation, Western blotting, and ELISA. The role of paraspeckle during adoptive T-cell transfer therapy for HCC in vivo was performed with a subcutaneous xenograft mouse.ResultsParaspeckle in HCC cells is negatively related to T-cell-mediated cytolysis. Destruction of paraspeckle in HCC cells by knockdown of NEAT1_2 or NONO significantly improved the sensibility of resistant HCC cells to T-cell killing effects. Furthermore, IFNGR1 mRNA, which is sequestered by NEAT1_2 and NONO, is abundant in paraspeckle of T-cell killing-resistant HCC cells. Incapable IFN-γ-IFNGR1 signaling accounts for paraspeckle mediated-adoptive T-cell therapy resistance. Moreover, NEAT1_2 expression negatively correlates with IFNGR1 expression in clinical HCC tissues.ConclusionsParaspeckle in HCC cells helps tumor cells escape from immunosurveillance through sequestering IFNGR1 mRNA to inhibiting IFN-γ-IFNGR1 signaling, thereby avoiding T-cell killing effects. Collectively, our results hint that NEAT1_2 highly expressed HCC patient is more resistant to T-cell therapy in clinic, and NEAT1_2 may be potential target for HCC immunotherapy.

Rutin attenuates Sorafenib-induced Chemoresistance and Autophagy in Hepatocellular Carcinoma by regulating BANCR/miRNA-590-5P/OLR1 Axis.

Rutin, the main component of Potentilla discolor Bunge, was proven to exhibit anti-tumor properties. Sorafenib (SO) is conventionally used in chemotherapy against hepatocellular carcinoma (HCC), but acquired resistance developed during long-term therapy limits its benefits. This study aimed to explore the molecular mechanism of rutin in SO-induced autophagy and chemoresistance in HCC. Sixty-eight paired HCC patients who received the same chemotherapy treatment were obtained. We also established two SO resistance cell lines and then utilized high-throughput RNA sequencing to explore their long non-coding RNA (lncRNA) expression profiles. The target microRNA (miRNA) and downstream mRNA were also explored. Our results indicated that rutin treatment attenuates autophagy and BANCR expression in SO resistance cells. Transmission electron microscopy clearly showed a significantly decreased number of autophagosomes after rutin-treated HepG2/SO and HCCLM3/SO cells. BANCR knockdown promotes the sensitivity of SO resistance cells to SO. Further study found that BANCR acts as a molecular sponge of miR-590-5P to sequester miR-590-5P away from oxidized low-density lipoprotein receptor 1 (OLR1) in HCC cells. Furthermore, in vivo study demonstrated that rutin could inhibit autophagy through the BANCR/miRNA-590-5P/OLR1 axis. Our findings suggest that rutin could regulate autophagy by regulating BANCR/miRNA-590-5P/OLR1 axis.

The Emerging Roles of Exosomes in the Chemoresistance of Hepatocellular Carcinoma

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MiR-361-3p Regulates Liver Tumor-initiating Cells Expansion and Chemo-resistance.

Increasing evidence shows that liver tumor-initiating cells (T-ICs) closely associated with the progression, metastasis, recurrence and chemo-resistance of hepatocellular carcinoma (HCC). However, the underlying mechanism for the propagation of liver T-ICs remains unclear. Here we show that miR-361-3p is upregulated in liver T-ICs. Knockdown of miR-361-3p impairs the self-renewal and tumorigenicity liver T-ICs. Conversely, forced miR-361-3p expression enhances the self-renewal and tumorigenicity liver T-ICs. Mechanistically, miR-361-3p directly targets SOX1 via binding its 3'-UTR in liver T-ICs. Moreover, miR-361-3p knockdown hepatoma cells are more sensitive to cisplatin or sorafenib treatment. Clinical cohort analysis demonstrates that miR-361-3p low HCC patients are benefited from TACE (transcatheter arterial chemoembolization) or sorafenib treatment. In conclusion, our findings revealed the crucial role of the miR-361-3p in liver T-IC expansion and TACE or sorafenib response, rendering miR-361-3p an optimal target for the prevention and intervention in HCC.

Circ_0031242 Silencing Mitigates the Progression and Drug Resistance in DDP-Resistant Hepatoma Cells by the miR-924/POU3F2 Axis.

BackgroundCircular RNAs (circRNAs) have been implicated in the progression and chemoresistance development of hepatocellular carcinoma (HCC). However, the precise parts of circ_0031242 in HCC chemoresistance are still not fully understood.MethodsThe levels of circ_0031242, miR-924 and POU class 3 homeobox 2 (POU3F2) were detected by quantitative real-time polymerase chain reaction (qRT-PCR) assay or Western blot analysis. IC50 value for cisplatin (DDP) and cell viability were measured by the cell counting kit-8 (CCK-8) assay. Cell migration, invasion and apoptosis were assessed by transwell assay and flow cytometry, respectively. Targeted correlations among circ_0031242, miR-924 and POU3F2 were verified by the dual-luciferase reporter and RNA immunoprecipitation (RIP) assays.ResultsOur data revealed that circ_0031242 was associated with HCC resistance to DDP. The silencing of circ_0031242 diminished DDP resistance, suppressed cell viability, migration, invasion and promoted apoptosis of DDP-resistant HCC cells (Huh7-R and SNU-387-R) in vitro, as well as enhanced DDP sensitivity in vivo. Mechanistically, circ_0031242 directly interacted with miR-924 by binding to miR-924. Moreover, miR-924 was a downstream effector of circ_0031242 function. POU3F2 was a direct target of miR-924, and miR-924 overexpression regulated DDP-resistant HCC cell progression and DDP resistance by down-regulating POU3F2. Furthermore, circ_0031242 modulated POU3F2 expression through sponging miR-924.ConclusionOur findings identified that circ_0031242 functioned as an important regulator in DDP-resistant HCC cell progression and DDP resistance through the miR-924/POU3F2 axis, illuminating circ_0031242 as a potential therapeutic target for the chemoresistant HCC.

Platycodin D reverses histone deacetylase inhibitor resistance in hepatocellular carcinoma cells by repressing ERK1/2-mediated cofilin-1 phosphorylation

BackgroundChemoresistance remains the main obstacle in hepatocellular carcinoma (HCC) therapy. Despite significant advances in HCC therapy, HCC still has a poor prognosis. Thus, there is an urgent need to identify a treatment target to reverse HCC chemotherapy resistance. Platycodon grandiflorus (PG) is a perennial herb that has been used as food and traditional Chinese medicine for thousands of years in Northeast Asia. Platycodin D (PD), a main active triterpenoid saponin found in the root of PG, has been reported to possess anticancer properties in several cancer cell lines, including HCC; however, the reversal effect of this molecule on HCC chemoresistance remains largely unknown. PurposeThis study aimed to investigate the role and the mechanism of PD-mediated reversal of the histone deacetylase inhibitor (HDACi) resistance in HCC cells. MethodsHuman HCC cells (HA22T) and HDACi-resistant (HDACi-R) cells were used. Cell viability was measured using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. Combination index was used to calculate the synergism potential. Expression of ERK1/2 (total/phospho), cofilin-1 (total/phospho) and apoptosis-related protein was determined using western blotting. Mitochondrial membrane potential was assessed using the JC-1 (5,5′,6,6′-tetrachloro-1,1′,3,3′-tetraethylbenzimidazolocarbocyanine iodide) probe. Apoptosis was detected using the terminal deoxynucleotidyl transferase dUTP nick end labeling assay. Mitochondrial reactive oxygen species generation was measured using the MitoSOX Red fluorescent probe. ResultsWe found that PD treatment inhibited cell viability both in HA22T HCC and HDACi-R cells. Inhibition of ERK1/2 by PD98059 could reverse drug resistance in HDACi-R cells treated with PD98059 and PD. Nevertheless, pre-treatment with U46619, an ERK1/2 activator, rescued PD-induced apoptosis by decreasing levels of apoptosis-related proteins in HCC cells. The combined treatment of PD with apicidin a powerful HDACi, dramatically enhanced the apoptotic effect in HDACi-R cells. ConclusionFor the first time, we showed that PD reversed HDACi resistance in HCC by repressing ERK1/2-mediated cofilin-1 phosphorylation. Thus, PD can potentially be a treatment target to reverse HCC chemotherapy resistance in future therapeutic trials.

Hepatocellular Carcinoma: A Difficult Cancer to Treat.

Hepatocellular carcinoma (HCC) is a very peculiar cancer because it presents several molecular alterations linked to the activation of survival and antiapoptotic signal pathways that are protein in form and not easily targetable by even the newest targeted therapies. In addition, it is almost always a consequence of liver cirrhosis, a serious disease condition in which several drugs are often not tolerated. This is why the study of HCC was such a challenge for Professor Natale D'Alessandro, to whom this work is dedicated, during the latter years of his career. The aim of this review is to summarize studies on different molecules involved in the development, progression, and chemoresistance of HCC, topics on which we have focused our research over the last decade. In particular, we have analyzed the role of inflammatory mediators, such as the cyclooxygenase (COX) enzymes, nuclear factor κB (NF-κB), interleukin 6 (IL-6), as well as other important factors, such as Yin Yang 1 (YY1), in HCC. Moreover, we have reviewed some more recent literature on research aimed at identifying druggable targets in HCC as well as candidate agents for its prevention and treatment.

A zinc finger family protein, ZNF263, promotes hepatocellular carcinoma resistance to apoptosis via activation of ER stress-dependent autophagy.

Hepatocellular carcinoma (HCC) is one of the leading causes of cancer death worldwide. Endoplasmic reticulum stress (ERS) is generally activated in HCC and is important for the sensitivity of HCC to anticancer drugs. ERS-dependent autophagy is a crucial mechanism affecting the sensitivity of HCC to anticancer drugs, but the mechanism by which ERS regulates autophagy is not well understood. Zinc finger protein 263 (ZNF263) is a transcription factor member of the zinc finger family. However, its functional role in HCC remains to be studied. In the current study, we investigated the role of ZNF263 in regulating ERS-induced chemoresistance in HCC and its possible mechanism. We found that ZNF263 was the most significant ERS-specific super-enhancer bounding transcriptional factor and was up-regulated in HCC patients and cell lines. Further, ZNF263 expression correlated with ERS, clinical stage and shorter survival in HCC patients. ZNF263 knockdown by RNA interference results in decreased proliferation, apoptosis resistance, and chemoresistance. Further study showed that ZNF263 increased chemoresistance by activating ERS-related autophagy. In conclusion, our study highlights ZNF263 as a functional ERS-related tumor activator and indicates it as a potential target for HCC therapy.

TAZ-regulated expression of IL-8 is involved in chemoresistance of hepatocellular carcinoma cells

Chemotherapy resistance is one of the major challenges for the treatment of hepatocellular carcinoma (HCC). In order to investigate the mechanisms involved in chemoresistance of HCC, we established cisplatin (CDDP) and doxorubicin (Dox) resistant HCC cells. The expression of transcriptional coactivator with PDZ-binding motif (TAZ), one of the major downstream effectors of Hippo pathway, was upregulated in chemoresistant HCC cells. Targeted inhibition of TAZ via its siRNAs can restore CDDP and Dox sensitivity of chemoresistant HCC cells. The upregulation of TAZ increased the expression of IL-8 in HCC/CDDP and HCC/Dox cells. Recombinant IL-8 (rIL-8) antagonized the increased chemosensitivity mediated by TAZ knockdown. Mechanistically, TAZ can directly bind with the promoter of IL-8 to activate its transcription in chemoresistant HCC cells. Collectively, our data showed that TAZ-regulated expression of IL-8 was involved in chemoresistance of HCC cells. It indicated that targeted inhibition of TAZ/IL-8 axis might be helpful to improve chemotherapy efficiency for HCC.

CircRNA circARNT2 Suppressed the Sensitivity of Hepatocellular Carcinoma Cells to Cisplatin by Targeting the miR-155-5p/PDK1 Axis

Circular RNA (circRNA) is a novel subclass of noncoding-RNA molecules that participate in development and progression of a variety of human diseases via sponging microRNAs (miRNAs). Until now, the contributions of circRNAs in chemoresistance of hepatocellular carcinoma (HCC) remain largely unknown. In the present study, we aimed to investigate the role of circRNA in cisplatin resistance of HCC. We investigated the expression of circRNAs in 5 paired cisplatin-sensitive and cisplatin-resistant HCC tissues by microarray analysis. The qRT-PCR analysis was to investigate the expression pattern of circARNT2 in HCC patient tissues and cell lines. Then, the effects of circARNT2 on cisplatin resistance, cell proliferation, and apoptosis were assessed in HCC in vitro and in vivo. circARNT2 was significantly upregulated in HCC tissues and cell lines. Overexpression of circARNT2 in HCC was significantly correlated with aggressive characteristics and served as an independent risk factor for overall survival in patients with HCC. In vitro experiments showed that knockdown of circARNT2 inhibited cell proliferation and enhances the cisplatin sensitivity of HCC cells. Furthermore, circARNT2 facilitates HCC progression in vivo. We demonstrated that circARNT2 acts as a sponge for miR-155-5p and verified that PDK1 is a novel target of miR-155-5p. In summary, our study demonstrated that circARNT2 modulates cisplatin resistance through miR-155-5p/PDK1 pathway. Our findings indicated that circARNT2 may serve as a promising therapeutic target for overcoming cisplatin resistance for HCC.

Abstract 6336: Non-canonical activation of Gli-2 by TGF-β/Smad3 signaling pathway in modulation of chemoresistance of hepatocellular carcinoma

Abstract BACKGROUND: It has been demonstrated in our previous study that poorly-differentiated hepatoma cells with low α-feto-protein (AFP) expression and a CD133-/EpCAM- surface profile exhibited aberrant hedgehog signaling (Hh) activity, epithelial-mesenchymal transition and chemoresistance. However, expression of canonical Hh molecules (Sonic ligand and SMO) was not increased in poorly-differentiated hepatoma cells in contrast to well-differentiated hepatoma cells, indicating that Hh transcription factors Gli-1/2 may be activated through a non-classic pathway. The present study aims to investigate whether the TGF-β/Smad3 pathway is responsible for Gli-2 activation through a non-canonical pathway. METHODS: Expression of Sonic Hh (Shh) and Smad3 was assessed in both hepatoma cells and HCC specimens. Gli-2 and Smad3 expression was suppressed by lentiviral vector-mediated RNA interference in poorly-differentiated hepatoma Huh-7-DN and HLE cells. Chemosensitivity was evaluated in hepatoma cells with a Gli-2 or Smad3 inhibitor. RESULTS: Significantly increased Gli-1 and Gli-2 protein levels were observed in 78% (11 out of 14) and 50% (7 out of 14) HCC specimens. In 7 HCC patients with a normal serum AFP value (<20 μg/L), Gli-1/2 protein levels were obviously higher than their pericancerous tissue. Moreover, increased Gli-2 and ABCC1 protein levels were accompanied with increased TGF-β1 and p-Smad3 protein levels in 5 out 7 HCC specimens; whereas Shh protein levels were similar to paired pericancerous tissue. Consistent with the findings from HCC specimens, significantly higher Gli-2 and p-Smad3 nuclear protein levels were associated with increased ABCC1 protein levels in poorly-differentiated hepatoma cells (Huh-7-trans, Huh-7-DN, HLE and HLF); whereas Shh and SMO protein levels were not significantly different from well-differentiated hepatoma Huh-7 and Hep3B cells. Suppressing Gli-2 expression by specific shRNA caused marked decreased expression of Gli-2 and ABCC1 in Huh-7-DN, Huh-7-trans and HLE cells. In addition, expression of Smad3, Gli-2 and ABCC1 was significantly down-regulated in HLE cells after infected with a lentiviral vector harboring shSmad3, indicating that Gli-2 is a downstream target of Smad3. Sorafenib IC50 was significantly reduced from 35.76 to 17.45 μM or 14.04 μM in HLE cells when treated with a GLI inhibitor (GANT-61) or a Smad3 inhibitor (SIS3) at 5 μM. A potential GLI-binding site in the ABCC1 promoter was identified. ABCC1-Gli-luciferase reporter activity was increased up to 39-fold in HLE cells when transfected with constructs containing the potential GLI-binding site, compared to the construct that lacked a GLI-binding site. CONCLUSION: TGF-β/Smad3 activated Gli-2 and its direct transcriptional target ABCC1 in poorly-differentiated and chemoresistant hepatoma cells. Suppressing TGF-β/Smad3/Gli-2 signaling activity confers a potential molecular target in partially alleviating Sorafenib resistance for the treatment of refractory hepatoma. Citation Format: Jia Ding, Hui-yan Li, Li Zhang, Xiao-tian Zhou, Jian Wu. Non-canonical activation of Gli-2 by TGF-β/Smad3 signaling pathway in modulation of chemoresistance of hepatocellular carcinoma [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 6336.

Long noncoding RNA LEF1‐AS1 acts as a microRNA‐10a‐5p regulator to enhance MSI1 expression and promote chemoresistance in hepatocellular carcinoma cells through activating AKT signaling pathway

Long noncoding RNAs (lncRNAs) contribute to the development of hepatocellular carcinoma (HCC), which could regulate various HCC biological characteristics. Here, the study seeks to investigate the role of lncRNA LEF1-AS1 in HCC cell chemoresistance by regulating microRNA (miR)-10a-5p and Musashi1 (MSI1). The microarray-based analysis was employed to identify the HCC-related lncRNA-miRNA-gene regulatory network. Expression patterns of LEF1-AS1, miR-10a-5p, and MSI1 in the HCC cell lines, tissues were accessed by means of reverse transcription-quantitative polymerase chain reaction. Next, the interaction among LEF1-AS1, miR-10a-5p, and MSI1 in HCC was accessed by bioinformatics and dual-luciferase reporter gene assay. Then, the cell line resistant to cisplatin was established, which was then treated with sh/oe-lncRNA LEF1-AS1, miR-10a-5p-mimic, and oe/sh-MSI1 vectors alone or in combination. Afterward, the effect of LEF1-AS1, miR-10a-5p, and MSI1 on HCC cell chemoresistance, proliferation, and apoptosis was assessed. At last, in vivo experiments confirmed the role of MSI1 in tumor growth and chemoresistance in HCC. LEF1-AS1 might potentially affect the growth and chemoresistance of HCC cells by regulating miR-10a-5p and MSI1. LEF1-AS1 and MSI1 expression patterns were elevated, while miR-10a-5p was repressed in HCC tissues and cell lines. LEF1-AS1 combined to miR-10a-5p and regulated MSI1, thereby activating the protein kinase B (AKT) signaling pathway. Knockdown of LEF1-AS1 and MSI1 or elevation of miR-10a-5p compromised the proliferation of Huh7 cell line resistant to DDP and promoted its chemosensitivity and apoptosis. At last, these in vitro findings were also confirmed in vivo. Our results unraveled LEF1-AS1 acts as a miR-10a-5p modulator to promote chemoresistance of HCC cells by stimulating MSI1 and activating the AKT signaling pathway, which might provide a novel therapeutic target for HCC.

Glycochenodeoxycholic acid induces stemness and chemoresistance via the STAT3 signaling pathway in hepatocellular carcinoma cells.

The poor prognosis of hepatocellular carcinoma (HCC) is primarily attributed to its high frequency of recurrence and resistance to chemotherapy. Epithelial-to-mesenchymal transition (EMT) and the acquisition of cancer stem cells (CSCs) are the fundamental drivers of chemoresistance in HCC. Glycochenodeoxycholic acid (GCDC), a component of bile acid (BA), has been reported to induce necrosis in primary human hepatocytes. In the present work, we investigated the function of GCDC in HCC chemoresistance. We found that GCDC promoted chemoresistance in HCC cells by down-regulating and up-regulating the expression of apoptotic and anti-apoptotic genes, respectively. Furthermore, GCDC induced the EMT phenotype and stemness in HCC cells and activated the STAT3 signaling pathway. These findings reveal that GCDC promotes chemoresistance in HCC by inducing stemness via the STAT3 pathway and could be a potential target in HCC chemotherapy.

LncRNA CRNDE facilitates epigenetic suppression of CELF2 and LATS2 to promote proliferation, migration and chemoresistance in hepatocellular carcinoma

Our study aimed to investigate the expression, functional significance, and related mechanism of long noncoding RNA CRNDE (colorectal neoplasia differentially expressed) in hepatocellular carcinoma (HCC) pathogenesis. The resulted revealed that CRNDE was significantly overexpressed in HCC tissues and cell lines, and was statistically correlated with poor clinical outcome. CRNDE knockdown markedly decreased HCC cell proliferation, migration, and chemoresistance. In addition, in vivo experiments confirmed the suppressive effect of CRNDE knockdown on HCC progression. Mechanically, CRNDE directly bound to EZH2 (enhancer of zeste homolog), SUZ12 (suppressor of zeste 12), SUV39H1, and mediated their inhibition of tumor suppressor genes, including CUGBP Elav-like family member 2 (CELF2) and large tumor suppressor 2 (LATS2). CELF2 exerted tumor suppressive effect in HCC and was involved in CRNDE-mediated oncogenic effect. In addition, the oncogenic effects of CRNDE on HCC proliferation, migration and tumorigenesis, as well as its inhibition of Hippo pathway were abolished by LATS2 overexpression. Together, our work demonstrated the importance of CRNDE in HCC progression and elucidated the underlying molecular mechanisms. These findings provided new insights into HCC pathogenesis and chemoresistance mediated by CRNDE.

Anti-tumour effects of PIM kinase inhibition on progression and chemoresistance of hepatocellular carcinoma.

Hepatocellular carcinoma (HCC) is a biologically aggressive cancer. Targeted therapy is in need to tackle challenges in the treatment perspective. A growing body of evidence suggests a promising role of pharmacological inhibition of PIM (proviral integration site for Moloney murine leukaemia virus) kinase in some human haematological and solid cancers. Yet to date, the potential application of PIM inhibitors in HCC is still largely unexplored. In the present study we investigated the pre-clinical efficacy of PIM inhibition as a therapeutic approach in HCC. Effects of PIM inhibitors on cell proliferation, migration, invasion, chemosensitivity, and self-renewal were examined in vitro. The effects of PIM inhibitors on tumour growth and chemoresistance in vivo were studied using xenograft mouse models. Potential downstream molecular mechanisms were elucidated by RNA sequencing (RNA-seq) of tumour tissues harvested from animal models. Our findings demonstrate that PIM inhibitors SGI-1776 and PIM447 reduced HCC proliferation, metastatic potential, and self-renewal in vitro. Results from in vivo experiments supported the role of PIM inhibition in suppressing of tumour growth and increasing chemosensitivity of HCC toward cisplatin and doxorubicin, the two commonly used chemotherapeutic agents in trans-arterial chemoembolisation (TACE) for HCC. RNA-seq analysis revealed downregulation of the MAPK/ERK pathway upon PIM inhibition in HCC cells. In addition, LOXL2 and ICAM1 were identified as potential downstream effectors. Taken together, PIM inhibitors demonstrated remarkable anti-tumourigenic effects in HCC in vitro and in vivo. PIM kinase inhibition is a potential approach to be exploited in formulating adjuvant therapy for HCC patients of different disease stages. © 2020 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Clinical significance and functional role of transmembrane protein 47 (TMEM47) in chemoresistance of hepatocellular carcinoma.

Chemoresistance is the main cause of chemotherapy failure in patients with hepatocellular carcinoma (HCC). The gene encoding transmembrane protein 47 (TMEM47) was previously identified to be significantly upregulated in HCC cell lines with acquired chemoresistance. The aim of the present study was to characterize the clinical significance and function of TMEM47 in HCC chemoresistance. The results demonstrated that the TMEM47 expression levels in the tumors of patients not responding to cisplatin-based transarterial chemoembolization (TACE) treatment was significantly higher compared with those in patients who responded to TACE treatment. Moreover, analyses from clinical samples and HCC cell lines indicated that TMEM47 expression may be upregulated in HCC in response to cisplatin treatment. Furthermore, the TMEM47 mRNA expression levels were positively correlated with the degree of cisplatin resistance of HCC cells. Overexpression of TMEM47 in HCC cells significantly promoted cisplatin resistance. The present study also demonstrated that targeted inhibition of TMEM47 could significantly reduce cisplatin resistance of cisplatin-resistant HCC cells via enhancing caspase-mediated apoptosis. In addition, targeted inhibition of TMEM47 enhanced the sensitivity of cisplatin-resistant cells to cisplatin via suppressing cisplatin-induced activation of the genes involved in drug efflux and metabolism. The present study also validated that TMEM47 expression was significantly correlated with multi-drug resistance-associated protein 1 in patients with HCC who received TACE treatment. In conclusion, the findings of the present study demonstrated that TMEM47 may be a useful biomarker for predicting the response to chemotherapy and a potential therapeutic target for overcoming HCC chemoresistance.

Secretory Clusterin: A Promising Target for Chemoresistance of Hepatocellular Carcinoma.

Hepatocellular carcinoma (HCC) is a leading cause of cancer-related deaths worldwide. Chemoresistance remains the major factor for limited efficacy of the HCC treatment. Thus, exploring the mechanisms underlying drug resistance is of great importance. Secretory clusterin (sCLU), a stressactivated and ATP-independent molecular chaperone, is up-regulated in numerous tumors and correlated with malignant phenotypes. For HCC, the implication of sCLU was previously addressed in tumor growth, metastasis, as well as early diagnosis and poor prognosis. Notably, accumulating studies have emphasized its vital role in drug resistance of HCC. Depletion of sCLU synergistically could enhance the sensitivity of HCC cells to a variety of chemotherapy agents. Herein, we summarized the potential mechanisms accounting for the sCLU-induced chemoresistance, including promoting apoptosis evasion, facilitating epithelial-mesenchymal transition (EMT), maintaining the viability of cancer stem cell (CSC), enhancing drug efflux capacity, and regulating autophagic activities. The current evidence suggest that targeting sCLU might be a promising approach in overcoming chemoresistance of HCC.