Nanoparticle-based approaches for doxorubicin delivery in hepatocellular carcinoma: Current strategies and emerging innovations.

BackgroundThe involvement of circular RNAs (circRNAs) in chemoresistance of tumors has been identified. Herein, this study aims to investigate the role and the underlying mechanism of circ_0003998 in doxorubicin (DOX) resistance in hepatocellular carcinoma (HCC).MethodsThe expression of circ_0003998 and microRNA (miR)-218-5p and eukaryotic translation initiation factor 5A-2 (EIF5A2) mRNA was detected using quantitative real-time polymerase chain reaction. Cell viability, migration and invasion were analyzed using cell counting kit-8, colony formation and transwell assay, respectively. The levels of matrix metallopeptidase 9 (MMP-9), E-cadherin, Vimentin, N-cadherin and EIF5A2 protein were detected using western blot. The interaction between miR-218-5p and circ_0003998 or EIF5A2 was confirmed by dual-luciferase reporter assay. In vivo experiments were performed using murine xenograft models.ResultsCirc_0003998 was elevated in HCC tissues, DOX-resistant tissues and cells, and circ_0003998 knockdown promoted DOX-sensitivity in HCC by inhibiting resistant cell viability, migration, invasion and EMT in vitro and enhanced DOX cytotoxicity in vivo. Bioinformatics analysis revealed circ_0003998 inhibited miR-218-5p expression, which was clarified to be a target of circ_0003998, and circ_0003998 knockdown sensitized HCC cell to DOX by sponging miR-218-5p. EIF5A2 was a target of miR-218-5p, and miR-218-5p mitigated DOX resistance in HCC cells through modulating EIF5A2 expression. Additionally, circ_0003998 served as a competing endogenous RNA for miR-218-5p to regulate EIF5A2 expression.ConclusionCirc_0003998 knockdown sensitized HCC cell to DOX by regulating miR-218-5p/EIF5A2 axis, indicating new markers of poor response to DOX and potential therapeutic strategies for the chemotherapy of HCC.

Chemoresistance is a major obstacle to hepatocellular carcinoma (HCC) chemotherapy. Our previous study found that long noncoding RNA lncARSR (lncRNA Activated in RCC with Sunitinib Resistance) activated Akt signaling via repressing phosphatase and tensin homolog (PTEN) during doxorubicin resistance in HCC. The purpose of this study is to further explore lncARSR-mediated mechanisms and roles during doxorubicin resistance in HCC. The expression of lncARSR was detected by real-time quantitative polymerase chain reaction (qPCR). Nuclear factor-kappa B (NF-κB) activity was detected by NF-κB luciferase reporter assays, western blot, and NF-κB transcription factor assays. The effects of NF-κB on lncARSR were detected by chromatin immunoprecipitation assay, promoter luciferase reporter assay, and real-time qPCR. The effects of lncARSR/Akt/NF-κB on doxorubicin resistance were detected by Cell Counting Kit-8 assay, capsase-3 activity assay, and terminal deoxynucleotidyl transferase-mediated dUTP nick end labelingassay. lncARSR activated NF-κB signaling through activation of Akt. NF-κB transactivated lncARSR through directly binding lncARSR promoter and increasing lncARSR promoter activity. Akt transactivated lncARSR via activating NF-κB signaling. Thus, lncARSR, Akt, and NF-κB formed a positive feedback regulatory loop in HCC. Through this feedback loop, lncARSR auto-regulated its transcription. Drug sensitivity assays showed that the lncARSR/Akt/NF-κB feedback regulatory loop promoted doxorubicin resistance in HCC. These findings identified the lncARSR/Akt/NF-κB feedback regulatory loop in HCC, which represent potential therapeutic targets for improving doxorubicin sensitivity in HCC.

Doxorubicin (DOX) is one of the most commonly used anticancer drugs in the treatment of hepatoma. However, acquired drug resistance is one of the major challenges for the chemotherapy. In this study, a down-regulation of miR-122 was observed in doxorubicin-resistant Huh7 (Huh7/R) cells compared with its parental Huh7 cells, suggesting miR-122 is associated with the chemoresistance. Meanwhile, luciferase reporter assay proved that the PKM2 is the target of miR-122, and we reported that the glucose metabolism is significantly up-regulated in Huh7/R cells. Importantly, overexpression of miR-122 in Huh7/R cells reversed the doxorubicin-resistance through the inhibition of PKM2, inducing the apoptosis in doxorubicin-resistant cancer cells. Thus, this study revealed that the dysregulated glucose metabolism contributes to doxorubicin resistance, and the inhibition of glycolysis induced by miR-122 might be a promising therapeutic strategy to overcome doxorubicin resistance in hepatocellular carcinoma.

Resistance to chemotherapy drugs remains a significant problem for the treatment of many types of cancer. Fascin-1 (FSCN-1) is an actin-bundling protein involved in the invasion and metastasis of a variety of tumors. However, its involvement in drug resistance in hepatocellular carcinoma (HCC) remains unclear. The present study aimed to investigate the function of FSCN-1 in HCC resistance to doxorubicin (DOX). FSCN-1 expression was increased in DOX-resistant HCC cell lines (SNU449 and SNU387) compared with DOX-sensitive cell lines (Huh7 and Hep3B). The resistance of HCC cells to DOX was decreased following FSCN-1 knockdown with small interfering RNA. FSCN-1 knockdown also significantly altered the expression of key markers of epithelial-mesenchymal transition (EMT). Notably, vimentin expression was reduced and epithelial-cadherin expression was increased. Furthermore, when EMT was suppressed through knockdown of Twist, an essential pathway of DOX-induced EMT, the viability of HCC cells following treatment with DOX was not affected by FSCN-1 expression. Furthermore, FSCN-1 knockdown eliminated hypoxia-induced doxorubicin resistance and EMT. The results of the present study indicated that FSCN-1 expression increased DOX resistance in HCC cells via the promotion of EMT, and this phenomenon was maintained in a hypoxic environment. FSCN-1 potentially represents a novel target to overcome resistance to DOX in HCC.

Connexin 32 affects doxorubicin resistance in hepatocellular carcinoma cells mediated by Src/FAK signaling pathway

This study aimed to investigate the impact of ginger extract (GE) loaded into chitosan nanoparticles (CNPs) in enhancing cytotoxicity and reducing cardiotoxicity of doxorubicin (DXN) in hepatocellular carcinoma (HCC) induced mice. DXN and GE were loaded into CNPs and cytotoxicity of loaded and unloaded drugs against HepG2 cells was evaluated. HCC was induced in male albino mice by injection of diethylnitrosamine (DINA). Mice were divided into eight groups (n = 15): (1) normal control, (2) DINA, (3) CNPs, (4) free DXN, (5) CNPs DXN, (6) free GE, (7) CNPs GE, and (8) CNPs DXN + CNPs GE. Both GE and DXN loaded into CNPs showed a greater decline in cell viability of HepG2 cells than the unloaded forms. GE CNPs displayed pronounced anticancer activity In Vivo through apoptosis, greater down-regulation of multidrug resistance 1, enhancement of anti-oxidant activity and depletion of vascular endothelial growth factor content in liver tissues. GE CNPs in combination with DXN CNPs showed nearly normal hepatic lobule architecture and the greatest increase in apoptotic cell count. Co-treatment group had decreased cardiac malondialdehyde, tumor necrosis factor-α and serum activity of creatine kinase and lactate dehydrogenase. Combination of GE CNPs and DXN CNPs might be a potentially effective therapeutic approach for HCC.

Hepatocellular carcinoma (HCC) is an invasive malignant neoplasm with a poor prognosis. The development of chemoresistance severely obstructs the chemotherapeutic efficiency of HCC treatment. Therefore, understanding the mechanisms of chemoresistance is important for improving the outcomes of patients with HCC. Eukaryotic translation initiation factor 5A2 (eIF5A2), which is considered to be an oncogene, has been reported to mediate chemoresistance in various types of cancer; however, its precise role in HCC remains unclear. Accumulating evidence has suggested that autophagy serves a dual role in cancer chemotherapy. The present study aimed to investigate the role of autophagy in eIF5A2-mediated doxorubicin resistance in HCC. High expression levels of eIF5A2 in human HCC tissues were observed by immunohistochemistry using a tissue microarray, which was consistent with the results of reverse transcription-quantitative PCR analysis in paired HCC and adjacent healthy tissues. HCC patient-derived tumor xenograft mouse model was used for the in vivo study, and knockdown of eIF5A2 effectively enhanced the efficacy of doxorubicin chemotherapy compared with that in the control group. Notably, eIF5A2 served as a repressor in regulating autophagy under chemotherapy. Silencing of eIF5A2 induced doxorubicin sensitivity in HCC cells by triggering lethal autophagy. In addition, 5-ethynyl-2′-deoxyuridine, lactate dehydrogenase release assay and calcein-AM/PI staining were used to determine the enhanced autophagic cell death induced by the silencing of eIF5A2 under doxorubicin treatment. Suppression of autophagy attenuated the sensitivity of HCC cells to doxorubicin induced by eIF5A2 silencing. The results also demonstrated that knockdown of the Beclin 1 gene, which is an autophagy regulator, reversed the enhanced autophagic cell death and doxorubicin sensitivity induced by eIF5A2 silencing. Taken together, these results suggested eIF5A2 may mediate the chemoresistance of HCC cells by suppressing autophagic cell death under chemotherapy through a Beclin 1-dependent pathway, and that eIF5A2 may be a novel potential therapeutic target for HCC treatment.

Hepatocellular carcinoma (HCC) is generally resistant to chemotherapy due to intrinsic or acquired drug resistances. Many molecules and signaling pathways are involved in chemo-resistance of HCC cells. However, the contribution of long noncoding RNA (lncRNA) to chemo-resistance of HCC cells is still largely unknown. In this study, we revealed the critical roles of long noncoding RNA lncARSR in chemo-resistance of HCC cells. lncARSR is upregulated in HCC, associated with large tumor size and advanced BCLC stage, and indicts poor prognosis. Functional assays showed that overexpression of lncARSR enhances doxorubicin resistance of HCC cells in vitro and in vivo. And while knockdown of lncARSR increases sensitivity of HCC cells to doxorubicin in vitro and in vivo. Mechanistically, we found that lncARSR physically associates with PTEN mRNA, promotes PTEN mRNA degradation, decreases PTEN expression, and activates PI3K/Akt pathway. PTEN is downregulated in HCC, and the expression of PTEN is negatively correlated with lncARSR in HCC tissues. Furthermore, the effects of lncARSR overexpression on doxorubicin resistance could be reversed by PI3K/Akt pathway inhibitor, and lncARSR knockdown-induced doxorubicin sensitivity could be reversed by PTEN depletion. Taken together, our results showed that upregulated lncARSR promotes doxorubicin resistance in HCC via modulating PTEN-PI3K/Akt pathway, and implied that lncARSR may serve as a promising prognostic biomarker and therapeutic target for HCC chemo-resistance. J. Cell. Biochem. 118: 4498-4507, 2017. © 2017 Wiley Periodicals, Inc.

The devastating prognosis of hepatocellular carcinoma (HCC) is partially attributed to chemotherapy resistance. Accumulating evidence suggests that the epithelial-mesenchymal transition (EMT) is a key driving force of carcinoma metastasis and chemoresistance in solid tumors. Leucine-rich repeat-containing G protein-coupled receptor 5 (Lgr5), as an EMT inducer, is involved in the potentiation of Wnt signaling in HCC. This study proposes uncovering the roles of Lgr5 in Doxorubicin (Dox) resistance of HCC to improve treatment efficacy for HCC.Methods: We investigated the expression and significance of Lgr5 in HCC tissue and different cell lines. The effect of Lgr5 in EMT and Dox resistance was analyzed in HCC cells and implanted HCC tumor models. A two-hybrid analysis, using the Lgr5 gene as the bait and a HCC cDNA library, was used to screen targeted proteins that interact with Lgr5. The positive clones were identified by coimmunoprecipitation (Co-IP) and Glutathione-S-transferase (GST) pull-down. The impact of the interaction on Dox resistance was investigated by a series of assays in vitro and in vivo .Result: We found that Lgr5 was upregulated and positively correlated with poor prognosis in HCC. Additionally, it functioned as a tumor promoter to increase cell migration and induce EMT in HCC cells and increase the resistance to Dox. We identified programmed cell death protein 5 (PDCD5) as a target gene of Lgr5 and we found that PDCD5 was responsible for Lgr5-mediated Dox resistance. Further analysis with Co-IP and GST pull-down assays showed that the N-terminal extracellular domain of Lgr5 could directly bind to PDCD5. Lgr5 induced p53 degradation by blocking the nuclear translocation of PDCD5 and leading to the loss of p53 stabilization. Lgr5 showed a protection against the inhibition of Dox on the growth of tumor subcutaneously injected. Moreover, Lgr5 suppressed Dox-induced apoptosis via the p53 pathway and attenuated the cytotoxicity of Dox to HCC.Conclusion: Lgr5 induces the EMT and inhibits apoptosis, thus promoting chemoresistance by regulating the PDCD5/p53 signaling axis. Furthermore, Lgr5 may be a potential target gene for overcoming Dox resistance.

Chemotherapy regiments have been widely used in the treatment of a variety of human malignancies including hepatocellular carcinoma (HCC). A major cause of failure in chemotherapy is drug resistance of cancer cells. Resistance to doxorubicin (DOX) is a common and representative obstacle to treat cancer effectively. Individual microRNA (miRNA) has been introduced in the evolution of DOX resistance in HCC in recent studies. However, a global and systematic assessment of the miRNA expression profiles contributing to DOX resistance is still lacking. In the present study, we applied high-throughput Illumina sequencing to comprehensively characterize miRNA expression profiles in both human HCC cell line (HepG2) and its DOX-resistant counterpart (HepG2/DOX). A total of 269 known miRNAs were significantly differentially expressed, of which 23 were up-regulated and 246 were down-regulated in HepG2/DOX cells, indicating that part of them might be involved in the development of DOX resistance. In addition, we have identified 9 and 13 novel miRNAs up- and down-expressed significantly in HepG2/DOX cells, respectively. miRNA profiling was then validated by quantitative real-time PCR for selected miRNAs, including 22 known miRNAs and 6 novel miRNAs. Furthermore, we predicted the putative target genes for the deregulated miRNAs in the samples. Function annotation implied that these selected miRNAs affected many target genes mainly involved in MAPK signaling pathway. This study provides us a general description of miRNA expression profiling, which is helpful to find potential miRNAs for adjunct treatment to overcome DOX resistance in future HCC chemotherapy.

Chronic hepatitis B virus (HBV) infection is the primary risk factor for the malignant progression of hepatocellular carcinoma (HCC). It has been reported that HBV X protein (HBx) possesses oncogenic properties, promoting hepatocarcinogenesis and chemoresistance. However, the detailed molecular mechanisms are not fully understood. Here, we aim to investigate the effects of miR-128-3p/SPG21 axis on HBx-induced hepatocarcinogenesis and chemoresistance. The expression of SPG21 in HCC was determined using bioinformatics analysis, quantitative real-time PCR (qRT-PCR), western blotting, and immunohistochemistry (IHC). The roles of SPG21 in HCC were elucidated through a series of in vitro and in vivo experiments, including real-time cellular analysis (RTCA), matrigel invasion assay, and xenograft mouse model. Pharmacologic treatment and flow cytometry were performed to demonstrate the potential mechanism of SPG21 in HCC. SPG21 expression was elevated in HCC tissues compared to adjacent non-tumor tissues (NTs). Moreover, higher SPG21 expression correlated with poor overall survival. Functional assays revealed that SPG21 fostered HCC tumorigenesis and invasion. MiR-128-3p, which targeted SPG21, was downregulated in HCC tissues. Subsequent analyses showed that HBx amplified TRPM7-mediated calcium influx via miR-128-3p/SPG21, thereby activating the c-Jun N-terminal kinase (JNK) pathway. Furthermore, HBx inhibited doxorubicin-induced apoptosis by engaging the JNK pathway through miR-128-3p/SPG21. The study suggested that SPG21, targeted by miR-128-3p, might be involved in enhancing HBx-induced carcinogenesis and doxorubicin resistance in HCC via the TRPM7/Ca2+/JNK signaling pathway. This insight suggested that SPG21 could be recognized as a potential oncogene, offering a novel perspective on its role as a prognostic factor and a therapeutic target in the context of HCC.

METTL3-mediated TUG1 regulation of miR-9 in doxorubicin resistance in HCC.

Hepatocellular carcinoma (HCC) is one of the most aggressive malignancies worldwide and is highly resistant to chemotherapy. Yes-associated protein (YAP) is the downstream effector of the Hippo signaling pathway, which is frequently overexpressed in many types of cancers. Amplification of the YAP gene and overexpression of YAP in HCC have previously been reported to contribute to hepatocyte malignant transformation and tumor progression. In this study, we aimed to investigate the potential role of YAP in HCC chemoresistance. Overexpression of YAP resulted in resistance against doxorubicin-induced apoptosis in HCC cell lines, whereas suppression of the endogenous YAP expression by RNA interference demonstrated the reverse effect. Western blotting revealed that, following exposure to doxorubicin, YAP-overexpressing cells exhibited decreased cleaved PARP, increased phosphorylation of Akt and ERK1/2, and elevated Bcl-xL expression in comparison to the vector control. Inhibition of YAP expression sensitized HCC cells to doxorubicin, by exhibiting increased cleaved PARP, decreased levels of phosphorylated Akt, phosphorylated ERK1/2 and Bcl-xL expression. In addition, pretreatment with the MEK1/2 inhibitor U0126 but not the PI3-K inhibitor LY294002 significantly enhanced doxorubicin-induced apoptosis and decreased Bcl-xL expression in YAP-overexpressing HCC cells. Our data provide evidence that overexpression of YAP plays an important role in conferring doxorubicin resistance to HCC, which is at least partially mediated by YAP-induced activation of the MAP kinase pathway. Targeting YAP may be a promising adjunct for overcoming doxorubicin resistance in HCC.

How should patients with hepatocellular carcinoma recurrence after liver transplantation be treated?

Piercing the armor of hepatobiliary cancer: Bcl-2 homology domain 3 (BH3) mimetics and cell death