Association of TIP30 expression and prognosis of hepatocellular carcinoma in patients with HBV infection

Novel oncogenes and tumor suppressor genes in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is a very deadly disease. HCC initiation and progression involve multiple genetic events, including the activation of proto-oncogenes and disruption of the function of specific tumor suppressor genes. Activation of oncogenes stimulates cell growth and survival, while loss-of-function mutations of tumor suppressor genes result in unrestrained cell growth. In this review, we summarize the new findings that identified novel proto-oncogenes and tumor suppressors in HCC over the past five years. These findings may inspire the development of novel therapeutic strategies to improve the outcome of HCC patients.

Anti-hepatitis B virus activity and hepatoprotective effect of des(rhamnosyl) verbascoside from Lindernia ruellioides in vitro

Although clinically approved hepatitis B virus (HBV) polymerase inhibitors (lamivudine-3TC, entecavir, etc.) serve as effective therapeutics, the virus can easily generate resistance to them. Therefore, the treatment of HBV infection remains a public health problem. Numerous studies have shown that natural products have prospective anti-HBV activity. The purpose of this study was to isolate and extract des(rhamnosyl) verbascoside from Lindernia ruellioides (Colsm.) Pennell and explore its anti-HBV and hepatoprotective effects. Anti-HBV activity was evaluated in HepG2.2.15 cells, a human hepatocellular carcinoma cell line with HBV-stable infection, and its protective effect was evaluated in HL-7702 cells, a normal human liver cell line. HepG2.2.15 cells maintained normal growth morphology within the selected concentration range of des(rhamnosyl) verbascoside. It also inhibited the expression of HBV antigens and HBV DNA in a dose- and time-dependent manner in vitro. Further, western blot experiments showed that it could downregulate HBV X protein (HBx) expression in a dose-dependent manner. In the H₂ O₂ -induced hepatocyte injury model, the cell-survival rate of the HL-7702 cells with the highest drug dose reached 85.25%, which was significantly improved compared with that of the model group. Most of the cells returned to normal morphology, showing polygonal or fusiform structures. Thus, it may be stated that des(rhamnosyl) verbascoside exhibits anti-HBV activity and hepatoprotective effects in vitro and may exert an anti-HBV effect via antigen inhibition, HBV DNA secretion, and HBx protein expression.

Absence of HTATIP2 Expression in A549 Lung Adenocarcinoma Cells Promotes Tumor Plasticity in Response to Hypoxic Stress

HIV-1 Tat Interactive Protein 2 (HTATIP2) is a tumor suppressor, of which reduced or absent expression is associated with increased susceptibility to tumorigenesis and enhanced tumor invasion and metastasis. However, whether the absent expression of HTATIP2 is a tumor-promoting factor that acts through improving tumor adaptation to hypoxia is unclear. Here, we established a stable HTATIP2-knockdown A549 human lung adenocarcinoma cell line (A549shHTATIP2) using lentiviral-delivered HTATIP2-targeting short hairpin RNA (shRNA), employed a double subcutaneous xenograft model and incorporated photoacoustic imaging and metabolomics approaches to elucidate the impact of the absent HTATIP2 expression on tumor response to hypoxic stress. Results from the in vivo study showed that A549shHTATIP2 tumors exhibited accelerated growth but decreased intratumoral oxygenation and angiogenesis and reduced sensitivity to sorafenib treatment as compared with their parental counterparts. Moreover, results of the immunoblot and real-time PCR analyses revealed that the HIF2α protein and mRNA levels in vehicle-treated A549shHTATIP2 tumors were significantly increased (p < 0.01 compared with the parental control tumors). Despite the strong HIF2α-c-Myc protein interaction indicated by our co-immunoprecipitation data, the increase in the c-Myc protein and mRNA levels was not significant in the A549shHTATIP2 tumors. Nonetheless, MCL-1 and β-catenin protein levels in A549shHTATIP2 tumors were significantly increased (p < 0.05 compared with the parental control tumors), suggesting an enhanced β-catenin/c-Myc/MCL-1 pathway in the absence of HTATIP2 expression. The finding of significantly decreased E-cadherin (p < 0.01 compared with vehicle-treated A549shHTATIP2 tumors) and increased vimentin (p < 0.05 compared with sorafenib-treated A549 tumors) protein levels in A549shHTATIP2 tumors implicates that the absence of HTATIP2 expression increases the susceptibility of A549 tumors to sorafenib-activated epithelial-mesenchymal transition (EMT) process. Comparison of the metabolomic profiles between A549 and A549shHTATIP2 tumors demonstrated that the absence of HTATIP2 expression resulted in increased tumor metabolic plasticity that enabled tumor cells to exploit alternative metabolic pathways for survival and proliferation rather than relying on glutamine and fatty acids as a carbon source to replenish TCA cycle intermediates. Our data suggest a mechanism by which the absent HTATIP2 expression modulates tumor adaptation to hypoxia and promotes an aggressive tumor phenotype by enhancing the HIF2α-regulated β-catenin/c-Myc/MCL-1 signaling, increasing the susceptibility of tumors to sorafenib treatment-activated EMT process, and improving tumor metabolic plasticity.

Subcongenic analysis of a quantitative trait locus affecting body weight and glucose metabolism in zinc transporter 7 (znt7)-knockout mice

Background

A genome-wide mapping study using male F₂zinc transporter 7-knockout mice (znt7-KO) and their wild type littermates in a mixed 129P1/ReJ (129P1) and C57BL/6J (B6) background identified a quantitative trait locus (QTL) on chromosome 7, which had a synergistic effect on body weight gain and fat deposit with the znt7-null mutation.

Results

The genetic segment for body weight on mouse chromosome 7 was investigated by newly created subcongenic znt7-KO mouse strains carrying different lengths of genomic segments of chromosome 7 from the 129P1 donor strain in the B6 background. We mapped the sub-QTL for body weight in the proximal region of the previously mapped QTL, ranging from 47.4 to 64.4 megabases (Mb) on chromosome 7. The 129P1 donor allele conferred lower body weight gain and better glucose handling during intraperitoneal glucose challenge than the B6 allele control. We identified four candidate genes, including Htatip2, E030018B13Rik, Nipa1, and Atp10a, in this sub-QTL using quantitative RT-PCR and cSNP detection (single nucleotide polymorphisms in the protein coding region).

Conclusions

This study dissected the genetic determinates of body weight and glucose metabolism in znt7-KO mice. The study demonstrated that a 17-Mb long 129P1 genomic region on mouse chromosome 7 conferred weight reduction and improved glucose tolerance in znt7-KO male mice. Among the four candidate genes identified, Htatip2 is the most likely candidate gene involved in the control of body weight based on its function in regulation of lipid metabolism. The candidate genes discovered in this study lay a foundation for future studies of their roles in development of metabolic diseases, such as obesity and type 2 diabetes.

Electronic supplementary material

The online version of this article (10.1186/s12863-019-0715-2) contains supplementary material, which is available to authorized users.

Expression of the Wnt ligands gene family and its relationship to prognosis in hepatocellular carcinoma

Background

The Wnt gene family members are known to participate regulating various normal and pathological processes including tumorigenesis. However, the association between Wnt ligands gene family and prognosis in hepatocellular carcinoma has not been systematically studied. Therefore, we evaluated the role of Wnt ligands gene family in hepatocellular carcinoma using publicly available data from The Cancer Genome Atlas (TCGA).

Methods

Clinical information and RNA-Seq mRNA expression data were derived from TCGA hepatocellular carcinoma cohort. Differences in overall survival (OS) and disease-free survival (DFS) between increased and decreased expression groups (defined by X-tile analyses) of Wnt ligands gene family were compared using Kaplan-Meier method and Cox regression model, with p-values calculated via log-rank test. Gene Set Enrichment Analysis (GSEA) was performed.

Results

Multivariate analysis adjusted for patient age, sex, BMI, tumor grade, and TMN stage revealed that Wnt1, Wnt3 and Wnt5B expressions were independent prognostic factors for OS and DFS (OS: HR = 0.58, P = 0.006; HR = 0.65, P = 0.03; HR = 0.56, P = 0.023, respectively; DFS: HR = 0.52, P < 0.001; HR = 1.93, P = 0.003; HR = 0.59, P = 0.011, respectively). Furthermore, expression of Wnt1 and Wnt5B was significantly associated with TMN stage (P = 0.02 and P = 0.03 for OS; P = 0.02 and P = 0.02 for DFS). GSEA showed that nucleotide excision repair was differentially enriched in Wnt1 low expression phenotype and aminoacyl trna biosynthesis and basal transcription factors were differentially enriched in Wnt5B low expression phenotype.

Conclusions

Our results identified associations of several Wnt ligands with prognosis of HCC patients, indicating that these genes could serve as prognostic biomarkers of HCC.

Low expression of VSIG4 is associated with poor prognosis in hepatocellular carcinoma patients with hepatitis B infection

Background

V-set and immunoglobulin domain containing protein 4 (VSIG4) was reported to play an important role in tumorigenesis. However, the expression and clinical relevance in hepatocellular carcinoma (HCC) remain unknown.

Materials and methods

First, the mRNA profiles of HCC were screened from The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus databases. VSIG4, a differentially expressed gene that has not been reported in HCC, was distinguished. Second, the correlation between VSIG4 expression and the prognosis of HCC patients from TCGA was analyzed. Third, VSIG4 mRNA level was detected in 36 pairs of HCC tissues and 4 HCC cell lines by PCR assay. And finally, prognosis analysis was assessed for 36 HCC patients with different expression levels of VSIG4.

Results

Bioinformatics analysis showed that VSIG4 expression was downregulated in HCC tissues, and the expression level of VSIG4 was negatively correlated with serum alpha fetal protein (AFP) level and tumor distant metastasis. Survival analysis of all HCC patients in TCGA indicated that the overall survival and disease-free survival were not significantly associated with VSIG4 expression. However, subgroup analysis showed that in the patients with hepatitis B virus-related HCC, both overall survival and disease-free survival were shorter in the low VSIG4 expression group. Our PCR results further showed that VSIG4 expression was significantly decreased in HCC tissues and HCC cell lines, and the disease-free survival in hepatitis B virus-related HCC patients with low VSIG4 expression was shorter than in those with high VSIG4 expression, which was consistent with the bioinformatics analysis results.

Conclusion

Our study suggests that VSIG4 is downregulated in HCC, and low expression of VSIG4 is associated with poor prognosis in hepatitis B virus-related HCC patients.

The prognostic value of CYP2C subfamily genes in hepatocellular carcinoma

Cytochrome P2C (CYP2C) subfamily members (CYP2C8, CYP2C9, CYP2C18, and CYP2C19) are known to participate in clinical drug metabolism. However, the association between CYP2C subfamily members and hepatocellular carcinoma (HCC) remains unclear. This study investigated the prognostic value of CYP2C subfamily gene expression levels with HCC prognosis. Data of 360 HCC patients in The Cancer Genome Atlas database and 231 in the Gene Expression Omnibus database were analyzed. Kaplan-Meier analysis and a Cox regression model were used to ascertain overall survival and recurrence-free survival, and to calculate median survival time using hazard ratios (HR) and 95% confidence intervals (CI). In TCGA database, low expression of CYP2C8, CYP2C9, and CYP2C19 in tumor tissue was associated with a short median survival time (all crude P = 0.001, adjusted P = 0.004, P = 0.047, and P = 0.020, respectively). In TCGA database, joint effects analysis of the combinations of CYP2C8 and CYP2C9, CYP2C8 and CYP2C19, and CYP2C9 and CYP2C19 revealed that high expression of two genes (group 4; group IV, group d) was associated with a reduced risk of death as compared to low expression (group 1, group I, and group a) (adjusted P = 0.005, P = 0.013, and P = 0.016, respectively). In TCGA database, joint effects analysis of CYP2C8, CYP2C9, and CYP2C19 showed that the risk of death from HCC was lower for groups C and D than for group A (adjusted P = 0.012 and P = 0.008, respectively). CYP2C8, CYP2C9, and CYP2C19 gene expression levels are potential prognostic markers of HCC following hepatectomy.

Association of TIP30 expression and prognosis of hepatocellular carcinoma in patients with HBV infection

Altered expression of TIP30, a tumor suppressor, has been observed in many cancers. In this study, we have evaluated the expression of TIP30 in the tissues of 209 hepatocellular carcinomas (HCC) and their adjacent tissues by using a high‐density tissue microarray, and analyzed its correlation with the clinical pathological parameters of the patients. The results revealed negative or weak expression of TIP30 in 43.5% (91/209) of the HCC tissues, and in only 27% (56/209) of the adjacent tissues. The expression level of TIP30 in HCC was inversely correlated with serum alpha‐fetoprotein (AFP) levels, HBV infection, and tumor differentiation. Multivariate analysis for survival indicated that serum HBV infection was the most significant predictor of poor prognosis in HCC (P = 0.0023), and TIP30 expression and tumor differentiation were also independent indicators in this respect (P = 0.0364 and P = 0.0397, respectively). Patients with medium or high expression levels of TIP30 (TIP30^++/+++) had a better 5‐year overall survival rate than those with low/negative (TIP30^+/−) expression (P < 0.001). TIP30^+/−/HBV⁺ patients had the worst 5‐year overall survival rate, whereas TIP30^++/+++/HBV⁻ patients had the best. To further explore the correlation between TIP30 and HBV infection in HCC, HBV⁺ hepatoblastoma cell‐line HepG2 2.2.15 and HCC cell‐line Hep3B were used. Upon silencing of HBV, we observed an upregulation of TIP30 and decreased cell proliferation. In the in vivo studies, we found that the mice inoculated with HepG2 2.2.15 cells with HBV silencing had a prolonged tumor latency and a longer life span, as compared to the control mice inoculated with untreated control cells. In conclusion, the results suggest that downregulation of TIP30 may result from HBV infection, and subsequently promotes the progression of HCC.