MCCC2 promotes HCC development by supporting leucine oncogenic function.

BACKGROUND: The role of methylcrotonoyl-CoA carboxylase 2 (MCCC2) in the development of tumors is well-established, and the involvement of leucine in the liver is well-known. However, the role of MCCC2 and the correlation between MCCC2 and leucine in the progression of hepatocellular carcinoma (HCC) have not yet been reported. METHODS: In this study, the Gepia database was used to evaluate the prognostic value of MCCC2 in HCC. The expression and localization of MCCC2 in HCC cells were determined by western blot and immunofluorescence assays. Flow cytometry and CCK-8 and transwell assays were carried out to explore the effect of MCCC2 on cell proliferation, migration, and invasion. In addition, mass spectrometry analysis was used to predict the potential cell function of MCCC2 in HCC. RESULTS: We found that the expression of MCCC2 increased in HCC tissues and that high expression of MCCC2 could predict poor outcomes in HCC patients. Knockdown expression of MCCC2 in HCC cells could reduce cell proliferation, migration, and invasion ability in vitro and could inhibit HCC cell proliferation in vivo. Interestingly, we found that HCC cells transfected with MCCC2-sgRNA failed to respond to leucine deprivation. Meanwhile, leucine deprivation inhibited cell proliferation, migration, and invasion in HCC cells where MCCC2 was present rather than in cells where MCCC2 was absent. In addition, knockdown of MCCC2 significantly reduced the glycolysis markers, glucose consumption, lactate secretion, and acetyl-CoA level, which is a product of leucine metabolism. Furthermore, we found that MCCC2 promotes the activation of ERK. Profiling the MCCC2 binding proteins revealed that MCCC2-associated proteins are enriched in biological processes, such as protein metabolism, energy pathway, and metabolism in HCC cells. CONCLUSIONS: Our findings revealed that MCCC2 plays a critical role in the development of HCC, and the leucine metabolism pathway might be a novel target in HCC treatment.

Nucleostemin promotes hepatocellular carcinoma by regulating the function of STAT3.

Hepatocellular carcinoma (HCC) is the most common primary malignant tumor in the liver and the second leading cause of cancer-related death worldwide. The collaborative function between Nucleostemin (NS) and STAT3 has been reported but not well studied in HCC. Here, we found a significant correlation between NS expression and STAT3 phosphorylation, not only in HCC cancers but also in HCC tissues. Patients with high expression of both NS and p-STAT3 show a very poor survival rate. High expression of both NS and p-STAT3 is also associated with tumor size and microvascular invasion. Knocking down the expression of NS greatly reduces the phosphorylation of STAT3. Conversely, overexpression of NS significantly promotes STAT3 phosphorylation. NS and p-STAT3 are located in the nucleus and physiologically interact with each other. Furthermore, NS greatly enhances cell migration and invasion by promoting the epithelial-mesenchymal transition (EMT). NS also supports cell proliferation and colony formation. The importance of NS in HCC was further demonstrated by evaluating tumor formation in vivo. Therefore, we demonstrate a critical collaborative function between NS and STAT3 in HCC, providing an invaluable insight into the mechanism of HCC. The concomitant expression of NS and p-STAT3 might be a potential prognostic indicator and therapeutic target in patients with HCC.

Ubiquitin-specific protease 7 is a drug-able target that promotes hepatocellular carcinoma and chemoresistance.

BACKGROUND: Ubiquitin-specific protease 7 (USP7) is a de-ubiquitin enzyme that plays an essential role in multiple cancers and becomes a target for treatment. However, the role of USP7 and its therapeutic value for HCC remains unclear. METHODS: USP7 expression was examined in HCC tissues by western blot and immunohistochemistry. The correlation of USP7 and HCC prognosis was analyzed by Kaplan-Meier survival method. Mass spectrometry was determined and cell proliferation and tumorigenicity assays were conducted in vitro and in vivo treated by P22077 and sgRNA-USP7. RESULTS: USP7 expression was significantly increased in HCC and associated with its progression. Interestingly, many HCC cells are sensitive to USP7 inhibition by using P22077. P22077 treatment not only induced cell death but also inhibited cell proliferation and migration in Huh7 and SK-Hep1 cells. In a xenograft model, P22077 efficiently inhibited tumor growth. In chemo-resistant HCC cells, P22077 decreased cell sensitivity to chemotherapy. In addition, mass spectrometry reveals 224 of significantly changed proteins upon P22077 treatment. CONCLUSIONS: We demonstrate a critical role of USP7 in HCC devolvement and chemoresistance. Disruption of USP7 function results in dis-regulated several key biological processes and subsequently activates BAX. USP7 might be a novel and drug-able target in HCC.

Coupling function of cyclin-dependent kinase 2 and Septin2 in the promotion of hepatocellular carcinoma.

Hepatocellular carcinoma (HCC) is a common and aggressive malignant tumor with a poorly defined molecular mechanism. Cyclin-dependent kinase 2 (CDK2) and Septin2 (SEPT2) are 2 known oncogenic molecules but the mechanism of functional interactions remains unclear. Here, we interestingly found that CDK2 and SEPT2 show very similar dynamic expression during the cell cycle. Both CDK2 and SEPT2 show the highest protein levels in the G2/M phase, resulting in CDK2 interacting with SEPT2 and stabilizing SEPT2 in HCC. In a panel of 8 pairs of fresh HCC tissues and corresponding adjacent tissues, both western blot and immunohistochemistry (IHC) assays demonstrate that CDK2 expression is highly correlated with SEPT2. HCC with high expression of both CDK2 and SEPT2 are more likely to relapse. This observation is further demonstrated by a large panel of 100 HCC patients. In this large panel, high expression of both CDK2 and SEPT2 significantly correlates with tumor differentiation and microvascular invasion, which is an independent prognostic factor in HCC patients. In summary, our results reveal a cooperative function between CDK2 and SEPT2. HCC with high expression of CDK2 and SEPT2 might be more aggressive and respond poorly to current therapy.

Exploration of Key Genes Combining with Immune Infiltration Level and Tumor Mutational Burden in Hepatocellular Carcinoma.

BACKGROUND: Hepatocellular carcinoma (HCC) is a lethal malignancy due to its heterogeneity and aggressive behavior. Recently, somatic mutations and tumor cell interactions with the surrounding tumor immune microenvironment (TIME) have been reported to participate in HCC carcinogenesis and predict HCC progression. In this study, we aimed to investigate the association between tumor mutational burden (TMB) and TIME in HCC. Additionally, we sought to identify differentially expressed genes (DEGs) associated with HCC prognosis and progression. METHODS: The expression, clinical, and mutational data were downloaded from the cancer genome atlas (TCGA) database. The immune infiltration levels and TMB levels of the HCC samples were estimated and the samples were divided into immune cluster (ICR)-1 and 2 based on immune infiltration score and high and low TMB groups based on TMB score. Thereafter, differential gene expression analysis was conducted to identify the DEGs in the ICR1/2 and high/low TMB groups, and the intersecting DEGs were selected. Thereafter, Cox regression analysis was performed on 89 significant DEGs, among which 19 were associated with prognosis. These 19 DEGs were then used to construct a prognostic model based on their expression levels and regression coefficients. Thereafter, we analyzed the DEGs in mutant and wildtype TP53 HCC samples and identified high BCL10 and TRAF3 expression in the mutant TP53 samples. BCL10 and TRAF3 expression was detected by real-time quantitative reverse transcription PCR and immunohistochemistry, and their clinical correlation, biological function, and immune infiltration levels were analyzed by chi-square analyses, Gene Set Enrichment Analysis (GSEA), and "ssGSEA", respectively. RESULTS: The results of our study revealed that immune infiltration level was correlated with TMB and that they synergistically predicted poor prognosis of HCC patients. DEGs enriched in immune-related pathways could serve as indicators of immunotherapy response in HCC. Among these DEGs, BCL10 and TRAF3 were highly expressed in HCC tissues, especially in the mutant TP53 group, and they co-operatively exhibited immunological function, thereby affecting HCC progression and prognosis. CONCLUSION: In this study, we identified BCL10 and TRAF3 as potential prognostic indicators in HCC patients. Additionally, we found that BCL10 and TRAF3 influence TMB and TIME in HCC patients and can be used for the development of immune-based therapies for improving the long-term survival of HCC patients.

High expression of Anxa2 and Stat3 promote progression of hepatocellular carcinoma and predict poor prognosis.

AIM: To elucidate whether the interaction between Anxa2 and Stat3 could promote the progression of hepatocellular carcinoma (HCC) and that high co-expression of Anxa2 and Stat3 could predict poor prognosis in HCC patients. METHODS: We investigated Anxa2 and Stat3 expression using Western blot analysis in 4 HCC and adjacent nontumor tissues and using immunohistochemistry in 100 patients' paraffin sections. Then we assessed the expression of Stat3, Anxa2 and co-expression of Stat3 and Anxa2 with relevant clinical pathological parameters and their prognostic value in HCC patients. The recurrence and overall survival rates were estimated using the Kaplan-Meier method and compared with the log-rank test. The prognostic analysis was carried out with univariate and multivariate Cox regressions models. RESULTS: The incidence of high Stat3 expression in HCC tissues (35%) was significantly higher than that in non-HCC tissues (8%) (P < 0.001). The same result was observed in Anxa2 (P < 0.001). Also, the overexpression of Stat3 or Anxa2 showed a significant relationship with the recurrence of the 100 HCC patients (P = 0.012; P = 0.003). Additionally, tumor size >3 cm in diameter, multiple tumor number, and the presence of microvascular tumor thrombus were also significantly associated with recurrence in 100 patients. Then, all enrolled patients were divided into four groups according to IHC score of Stat3 and Anxa2, and the results indicated a significant difference in recurrence time between the subgroups (P < 0.001). What's more, co-highexpression of Stat3 and Anxa2 was related to the presence of microvascular tumor thrombus (P = 0.003) and poor tumor differentiation (P < 0.001), but not relevant with other clinical features (All P > 0.05). CONCLUSION: The expression of Stat3, Anxa2, or co-high-expression of the two proteins was associated with HCC recurrence and survival.

ARP3 promotes tumor metastasis and predicts a poor prognosis in hepatocellular carcinoma.

Hepatocellular carcinoma (HCC) is the second leading cause of cancer-related death worldwide. Therefore, the study of the precise molecular mechanism underlying hepatocarcinogenesis has profound significance. In this study, we found that the expression of ARP3 was significantly up-regulated in HCC tissues and cell lines. Studies in liver cancer specimens showed that the expression of ARP3 is closely related to the pathological grade, distant metastasis and vascular invasion of HCC. According to the results of multivariate analysis, ARP3 is an independent prognostic factor for HCC patients. In vitro, knockdown of ARP3 expression significantly inhibited the invasion and migration of HCC cells and altered the expression of EMT markers. Based on the above conclusions, we conclude that ARP3 may be a potential prognostic indicator and therapeutic target for HCC patients.