Background: The identification of novel targets for recovering sorafenib resistance is pivotal for Hepatocellular carcinoma (HCC) patients. Mitophagy is the programmed degradation of mitochondria, and is likely involved in drug resistance of cancer cells. Here, we identified hyperactivated mitophagy is essential for sorafenib resistance, and the mitophagy core regulator gene ATAD3A (ATPase family AAA domain containing 3A) was down regulated in hypoxia induced resistant HCC cells. Blocking mitophagy may restore the sorafenib sensitivity of these cells and provide a new treatment strategy for HCC patients.Methods: Hypoxia induced sorafenib resistant cancer cells were established by culturing under 1% O₂with increasing drug treatment. RNA sequencing was conducted in transfecting LM3 cells with sh-ATAD3A lentivirus. Subsequent mechanistic studies were performed in HCC cell lines by manipulating ATAD3A expression isogenically where we evaluated drug sensitivity, molecular signaling events. In vivo study, we investigated the combined treatment effect of sorafenib and miR-210-5P antagomir.Results: We found a hyperactivated mitophagy regulating by ATAD3A-PINK1/PARKIN axis in hypoxia induced sorafenib resistant HCC cells. Gain- and loss- of ATAD3A were related to hypoxia-induced mitophagy and sorafenib resistance. In addition, ATAD3A is a functional target of miR-210-5p and its oncogenic functions are likely mediated by increased miR-210-5P expression. miR-210-5P was upregulated under hypoxia and participated in regulating sorafenib resistance. In vivo xenograft assay showed that miR-210-5P antagomir combined with sorafenib abrogated the tumorigenic effect of ATAD3A down-regulation in mice.Conclusions: Loss of ATAD3A hyperactivates mitophagy which is a core event in hypoxia induced sorafenib resistance in HCC cells. Targeting miR-210-5P-ATAD3A axis is a novel therapeutic target for sorafenib-resistant HCC.

In our previous studies, the Illumine Soledad massively parallel signature sequencing of miRNomes in non‑tumor and hepatocellular carcinoma (HCC) tissues revealed that microRNA (miR)-144-3p was significantly downregulated in HCC, but its role in HCC development, especially angiogenesis, remains unclear. In this investigation, we found recovering miR‑144‑3p expression can significantly suppress the growth, migration and induced angiogenic capacity of HCC cells through both in vivo and in vitro experiments. Moreover, clinical correlation analysis showed that low expression of miR‑144‑3p was positively correlated to poor disease-free survival (DFS) of HCC patients. Mechanistically, serum and glucocorticoid kinase 3 (SGK3), the putative targets of miR‑144‑3p, was predicted by Target Scan database and identified to be suppressed by miR‑144‑3p so that inhibiting the activation of mTOR-VEGF downstream signals was activated by the phosphoinositide 3-kinase (PI3K)-independent pathway. Hence, we concluded that miR‑144‑3p, which is frequently downregulated in HCC, can inhibit proliferation, migration and repress angiogenesis by regulating SGK3 activation with PI3K independent signal pathway, and acts as a prognostic factor for HCC patients.

Hepatocellular carcinoma (HCC) is a huge threat for human health worldwide. As a complicated tumor, the molecular basis for HCC development especially metastasis requires exploration. Although RNA binding motif (RBM) proteins are closely related to various cancers, the clinical importance and underlying mechanisms of RBM8A in HCC remain elusive. In this study, we found that RBM8A was highly expressed in HCC tumor tissues compared to normal liver tissues. Overexpression of RBM8A was associated with HbsAg and Edmondson pathological grading. Moreover, Kaplan-Meier survival analysis showed that high expression of RBM8A was related to the poor overall survival and progression-free survival of patients with HCC. Gain- and loss-of-function experiments further demonstrated that RBM8A promoted tumor cell migration and invasion in HCC via activation of epithelial-mesenchymal transition signaling pathway. It is also noteworthy that RBM8A is required for tumor cell proliferation and anti-apoptosis in HCC. Altogether, our results revealed a close relationship between RBM8A and HCC prognosis as well as a critical tumor-promoting function of RBM8A in HCC progression, suggesting that RBM8A might be a potential bio-marker and drug target in HCC therapy.

The anti-angiogenic drugs represented by sorafenib over the years have always been the first-line treatment of hepatocellular carcinoma (HCC), but the drug resistance has always been a "bottleneck" in curative effect. Recently, aberrant expression of circular RNA (circRNA) is considered to play a crucial role in many types of cancers. However, the genome-wide expression pattern of circRNAs in sorafenib-resistant HCC cells remains unknown. Herein, we identified 1717 differentially expressed circRNAs with 559 up-regulated and 1158 down-regulated (fold change > 2, P < 0.05) in sorafenib-resistant (HUH7-S) HCC cells along with 582 differentially expressed circRNAs with 272 up-regulated and 310 down-regulated (fold change > 2, P < 0.05) in sorafenib-resistant (HepG2-S) HCC cells, compared to parental sorafenib-sensitive (HUH7, HepG2) HCC cells by high-throughput sequencing. In addition, GO (Gene Ontology) term enrichment analysis results revealed an enrichment for binding and catalytic activity and for biological regulation of metabolic processes in both the Huh7-S and HepG2-S cell lines compared to parental cell lines. Moreover, KEGG (Kyoto Encyclopedia of Genes and Genomes) Pathway analysis of the differentially expressed genes were significantly related to pathways in cancer. Among them, hsa_circ_0006294 and hsa_circ_0035944 expression were consistently down-regulated in resistant HCC cells. Taken together, our data demonstrate, using a global transcriptomic network, that the circRNA expression profile is significantly altered in sorafenib-resistant HCC cells and that the differentially expressed circRNAs may play important functions in HCC sorafenib resistance and HCC progression.

Objective: Pancreatic cancer (PC) is an extremely malignant tumor with similar morbidity and mortality and lack of an effective treatment. This study explored the prognostic value and molecular mechanisms of proteasome 26S subunit, non-ATPase (PSMD) family genes in pancreatic ductal adenocarcinoma (PDAC). Methods: Survival analyses were performed to elucidate the relationship between prognosis and the level of PSMD expression. ROC curves and nomograms were constructed to predict the prognosis. A bioinformatics analysis was used to explore the co-expression and complex interaction networks of PSMDs. The potential mechanisms were further explored via gene set enrichment analysis (GSEA). Results: We find high levels of PSMD6, PSMD9, PSMD11, and PSMD14 expression were significantly associated with a poorer OS. High PSMD6 and PSMD11 expression was associated with a poorer relapse-free survival (RFS). A risk score model was constructed based on prognosis-related genes. The area under ROC curves (AUC) was 53.3%, 59.3%, and 62.9% for 1-, 2-, 3 years, respectively. Conclusion: GSEA revealed that PSMD6 and PSMD11 play a role in PDAC through various biological processes and signaling pathways, including TP53, CDKN2A, MYC pathway, DNA repair, KRAS, cell cycle checkpoint, NIK, NF-κB signaling pathway, and proteasomes. This study demonstrated that PSMD6 and PSMD11 could serve as a potential prognostic and diagnostic biomarkers for patients with early-stage PDAC after pancreaticoduodenectomy.