Identification of a TRP channel-related risk model for predicting prognosis and therapeutic effects of patients with hepatocellular carcinoma.

PURPOSE: TRP channels have been implicated in cancer progression. Our study seeks to establish a prognostic model for hepatocellular carcinoma (HCC) by utilizing genes related to TRP channels. METHODS: We used the TCGA and ICGC databases as training and validation cohorts, respectively. We calculated the risk scores using Lasso-Cox regression analysis based on the expression levels of prognostic genes and performed survival analysis to compare overall survival between high- and low-risk groups. Then we compared the clinicopathologic characteristics and conducted biological functional analysis. We also explored immune cell infiltration and compared the drug sensitivity. RESULTS: Using bioinformatics algorithms, we identified 11 TRP-related genes and calculated the risk scores. Patients in the high-risk group demonstrated worse overall survival, as well as more advanced T stage and pathologic stage. The risk score showed a significant association with the cell cycle. The high-risk group had more ICI and RTK targets with elevated expression and showed better therapeutic effect to chemotherapy including 5-fluorouracil, camptothecin, docetaxel, doxorubicin, gemcitabine, and paclitaxel. Overall, an individualized nomogram was constructed by integrating the risk score and requisite clinicopathologic parameters to predict the overall survival of HCC patients. CONCLUSIONS: We successfully established a highly accurate prognostic model for predicting overall survival and therapeutic effects using TRP channel-related genes.

SLC12A5 promotes hepatocellular carcinoma growth and ferroptosis resistance by inducing ER stress and cystine transport changes.

BACKGROUND: Hepatocellular carcinoma (HCC) has a poor prognosis and new effective treatments are needed. SLC12A5 plays important roles in multiple complex pathological states and is overexpressed in a variety of malignancies. However, the effects of SLC12A5 in HCC have not been determined. METHODS: SLC12A5 expression was assessed by immunostaining and western blotting. A cell viability assay was used to detect cell proliferation. Flow cytometry was used to evaluate the intracellular calcium concentration and cell cycle. Ferroptosis was detected by transmission electron microscopy, lipid peroxidation, and glutathione assays. Subcutaneous tumor formation experiments were used to validate the tumorigenic effect of SLC12A5 in vivo. RNA-seq was used to evaluate the molecular mechanisms underlying the effects of SLC12A5. The therapeutic efficacy of targeting SLC12A5 was assessed in a patient-derived xenograft (PDX) model. RESULTS: High SLC12A5 expression was strongly associated with a poor clinical prognosis and promoted HCC growth. Mechanistically, SLC12A5 promoted ER stress to enhance calcium release and upregulated PNCK expression levels. Concomitantly, PNCK was significantly activated by calcium ions released from the ER. PNCK activated and induced the phosphorylation of PI3K/AKT/mTOR pathway components. Furthermore, SLC12A5 inhibited ferroptosis in HCC by upregulating the expression of xCT, a cystine transporter. CONCLUSION: High SLC12A5 levels were correlated with a poor prognosis, promoted tumorigenesis, and inhibited ferroptosis in HCC. These findings suggested that SLC12A5 is a therapeutic target and provide insight into the link between ER stress and ferroptosis in HCC.

TRPM8 promotes hepatocellular carcinoma progression by inducing SNORA55 mediated nuclear-mitochondrial communication.

Transient receptor potential melastatin 8 (TRPM8) play crucial roles in solid tumors such as prostate and breast cancers. But the role of TRPM8 in hepatocellular carcinoma (HCC) and its underlying molecular mechanisms remain largely unknown. In this study, the functional roles of TRPM8 in HCC were systematically investigated for the first time. It was found that the expression level of TRPM8 was significantly upregulated in HCC, which was positively correlated with the worse clinicopathological characteristics. Functional studies revealed that pharmacological inhibition or genetic downregulation of TRPM8 ameliorated hepatocarcinogenesis in vitro and in vivo. Mechanistically, the oncogenic role of TRPM8 in HCC was at least partially achieved by affecting mitochondrial function. TRPM8 could modulate the expression of nucleolar relative molecule-small nucleolar RNA, H/ACA box 55 (SNORA55) by inducing transformation of chromatin structure and histone modification type. These data suggest that as a bridge molecule in TRPM8-triggered HCC, SNORA55 can migrate from nucleus to mitochondria and exert oncogenic role by affecting mitochondria function through targeting ATP5A1 and ATP5B. Herein, we uncovered the potent oncogenic role of TRPM8 in HCC by inducing nuclear and mitochondrial dysfunction in a SNORA55 dependent manner, and provided a potential therapeutic target for HCC.

Knockdown of Long Noncoding RNA Urothelial Carcinoma-Associated 1 Represses Gallbladder Cancer Advancement by Regulating SPOCK1 Expression Through Sponging miR-613.

Background: Gallbladder cancer (GBC) is the most common biliary tract malignancy. Long noncoding RNA urothelial carcinoma-associated 1 (UCA1) and MicroRNA-613 (miR-613) have been reported to be involved in the progression of various cancers. However, the regulatory mechanism between UCA1 and miR-613 in GBC is unclear. Materials and Methods: The expression levels of UCA1, miR-613, and secreted protein/osteonectin, cwcv, and kazal-like domains proteoglycan 1 (SPOCK1) mRNA were detected using quantitative real-time polymerase chain reaction. Cell proliferation, migration, invasion, and apoptosis were determined with MTT, transwell, or flow cytometry assays. The levels of SPOCK1 protein, Bax, cleaved-casp-3, and Bcl-2 were determined by Western blot analysis. The relationship between miR-613 and UCA1 or SPOCK1 was verified through dual-luciferase reporter and/or RNA immunoprecipitation assays. Xenograft assay was performed to verify the role of UCA1 in vivo. Results: UCA1 and SPOCK1 were upregulated, whereas miR-613 was downregulated in GBC tissues and cells. UCA1 silencing decreased tumor growth in vivo and impeded proliferation, migration, invasion, and induced apoptosis of GBC cells in vitro. Notably, UCA1 acted as a sponge for miR-613, which targeted SPOCK1 in GBC cells. Moreover, UCA1 enhancement reversed the repressive impact of miR-613 mimic on the malignancy of GBC cells. UCA1 regulated SPOCK1 expression through adsorbing miR-613. Furthermore, SPOCK1 elevation overturned UCA1 silencing mediated the malignant behaviors of GBC cells. Conclusion: UCA1 knockdown suppressed GBC progression through downregulating SPOCK1 via sponging miR-613, providing an evidence for UCA1 as a target for GBC treatment.

TRPM8 contributes to liver regeneration via mitochondrial energy metabolism mediated by PGC1α.

Impairment of liver regeneration leads to severe morbidity in acute and chronic severe liver disease. Transient receptor potential melastain 8 (TRPM8) is involved in a variety of processes, including temperature sensing, ion homeostasis, and cell proliferation. However, whether TRPM8 contributes to liver regeneration is still unclear. We assessed the effect and mechanism of TRPM8 in liver regeneration and hepatocyte proliferation in vivo and in vitro. In this study, we found that TRPM8 deficiency impairs liver regeneration in mice. Mechanistically, the results revealed that mitochondrial energy metabolism was attenuated in livers from TRPM8 knockout (KO) mice. Furthermore, we found that TRPM8 contributes to the proliferation of hepatocytes via PGC1α. Taken together, this study shows that TRPM8 contributes to liver regeneration in mice after hepatectomy. Genetic approaches and pharmacological approaches to regulate TRPM8 activity may be beneficial to the promotion of liver regeneration.

Comprehensive multiomics analysis of cuproptosis-related gene characteristics in hepatocellular carcinoma.

Background: The mechanism of copper-induced cell death, which is called cuproptosis, has recently been clarified. However, the integrated role of cuproptosis-related genes in hepatocellular carcinoma (HCC) and its relationship with immune characteristics are still completely unknown. Methods: In this study, the expression, genetic, and transcriptional regulation states of 16 cuproptosis-related genes in HCC were systematically investigated. An unsupervised clustering method was used to identify distinct expression patterns in 370 HCC patients from the TCGA-HCC cohort. Differences in functional characteristics among different expression clusters were clarified by gene set variation analysis (GSVA). The abundances of immune cells in each HCC sample were calculated by the CIBERSORT algorithm. Next, a cuproptosis-related risk score was established based on the significant differentially expressed genes (DEGs) among different expression clusters. Results: A specific cluster of HCC patients with poor prognosis, an inhibitory immune microenvironment, and high expression levels of immune checkpoint molecules was identified based on the expression of the 16 cuproptosis-related genes. This cluster of patients could be well-identified by a cuproptosis-related risk score system. The prognostic value of this risk score was validated in the training and two validation cohorts (TCGA-HCC, China-HCC, and Japan-HCC cohorts). Moreover, the overall expression status of the cuproptosis-related genes and the genes used to establish the cuproptosis-related risk score in specific cell types of the tumor microenvironment were preliminarily clarified by single-cell RNA (scRNA) sequencing data. Conclusion: These results indicated that cuproptosis-related genes play an important role in HCC, and targeting these genes may ameliorate the inhibitory immune microenvironment to improve the efficacy of immunotherapy with immune checkpoint inhibitors (ICIs).

Transient Receptor Potential Vanilloid-1 (TRPV1) Alleviates Hepatic Fibrosis via TGF-ß Signaling.

Hepatic fibrosis is a major global health problem and considered a leading cause of liver-related morbidity and mortality worldwide. Although previous studies have suggested that transient receptor potential vanilloid-1 (TRPV1) is protective against cardiac and renal fibrosis, its functional role in hepatic fibrosis has remained elusive. Herein, we characterize the effects of TRPV1 on carbon tetrachloride- (CCl4-) induced mice, in vitro transforming growth factor-ß- (TGF-ß-) treated hepatic stellate cells (HSCs), and human fibrosis specimens. Finally, our results demonstrated the significant TRPV1 downregulation in human liver fibrosis tissues. Knocking out TRPV1 significantly increased the expression of various hepatic fibrosis markers, while the expression of these biomarkers declined markedly in capsaicin-activated mice. Moreover, our study revealed that knocking down TRPV1 would enhance the promotive effect of TGF-ß on HSC proliferation, cell cycle, cell apoptosis, and ECM expression. Also, such promotive effect can be partially reversible by capsaicin, an exogenous activator of TRPV1. Collectively, the obtained data suggest that TRPV1 may alleviate CCl4-induced hepatic fibrosis and attenuate the effect of TGF-ß on HSC activation, proliferation, and apoptosis, which overall implies that targeting TRPV1 channel activity may be an effective therapeutic strategy for treating hepatic fibrosis.

TGFß-Associated Signature Predicts Prognosis and Tumor Microenvironment Infiltration Characterization in Gastric Carcinoma.

Background: Gastric carcinoma (GC) is a carcinoma with a high incidence rate, and it is a deadly carcinoma globally. An effective tool, that is, able to predict different survival outcomes for GC patients receiving individualized treatments is deeply needed. Methods: In total, data from 975 GC patients were collected from TCGA-STAD, GSE15459, and GSE84437. Then, we performed a comprehensive unsupervised clustering analysis based on 54 TGFß-pathway-related genes and correlated these patterns with tumor microenvironment (TME) cell-infiltrating characteristics. WGCNA was then applied to find the module that had the closest relation with these patterns. The least absolute shrinkage and selection operator (LASSO) algorithm was combined with cross validation to narrow down variables and random survival forest (RSF) was used to create a risk score. Results: We identified two different TGFß regulation patterns and named them as TGFß Cluster 1 and Cluster 2. TGFß Cluster 1 was linked to significantly poorer survival outcomes and represented an inflamed TME subtype of GC. Using WGCNA, a module (magenta) with the closest association with the TGFß clusters was identified. After narrowing down the gene list by univariate Cox regression analysis, the LASSO algorithm and cross validation, four of the 243 genes in the magenta module were applied to build a risk score. The group with a higher risk score exhibited a considerably poorer survival outcome with high predictive accuracy. The risk score remained an independent risk factor in multivariate Cox analysis. Moreover, we validated this risk score using GSE15459 and GSE84437. Furthermore, we found that the group with a higher risk score represented an inflamed TME according to the evidence that the risk score was remarkably correlated with several steps of cancer immunity cycles and a majority of the infiltrating immune cells. Consistently, the risk score was significantly related to immune checkpoint genes and T cell-inflamed gene expression profiles (GEPs), indicating the value of predicting immunotherapy. Conclusions: We have developed and validated a TGFß-associated signature, that is, capable of predicting the survival outcome as well as depicting the TME immune characteristics of GC. In summary, this signature may contribute to precision medicine for GC.

A novel DNA methylation-driver gene signature for long-term survival prediction of hepatitis-positive hepatocellular carcinoma patients.

BACKGROUND: Abnormal DNA methylation is one of the most general epigenetic modifications in hepatocellular carcinoma (HCC). Recent research showed that DNA methylation was a prognostic indicator of all-cause HCC and nonviral HCC. However, whether DNA methylation-driver genes could be used for predicting survival, the probability of hepatitis-positive HCC remains unclear. METHODS: In this study, DNA methylation-driver genes (MDGs) were screened by a joint analysis of methylome and transcriptome data of 142 hepatitis-positive HCC patients. Subsequently, a prognostic risk score and nomogram were constructed. Finally, correlation analyses between the risk score and signaling pathways and immunity were conducted by GSVA and CIBERSORT. RESULTS: Through random forest screening and Cox progression analysis, 10 prognostic methylation-driver genes (AC008271.1, C11orf53, CASP8, F2RL2, GBP5, LUCAT1, RP11-114B7.6, RP11-149I23.3, RP11-383 J24.1, and SLC35G2) were screened out. As a result, a prognostic risk score signature was constructed. The independent value of the risk score for prognosis prediction were addressed in the TCGA-HCC and the China-HCC cohorts. Next, clinicopathological features were analyzed and HBV status and histological grade were screened to construct a nomogram together with the risk score. The prognostic efficiency of the nomogram was validated by the calibration curves and the concordance index (C index: 0.829, 95% confidence interval: 0.794-0.864), while its clinical application ability was confirmed by decision curve analysis (DCA). At last, the relationship between the risk score and signaling pathways, as well as the correlations between immune cells were elucidated preliminary. CONCLUSIONS: Taken together, our study explored a novel DNA methylation-driver gene risk score signature and an efficient nomogram for long-term survival prediction of hepatitis-positive HCC patients.

TRPM8 deficiency attenuates liver fibrosis through S100A9-HNF4α signaling.

BACKGROUND: Liver fibrosis represent a major global health care burden. Data emerging from recent advances suggest TRPM8, a member of the transient receptor potential (TRP) family of ion channels, plays an essential role in various chronic inflammatory diseases. However, its role in liver fibrosis remains unknown. Herein, we assessed the potential effect of TRPM8 in liver fibrosis. METHODS: The effect of TRPM8 was evaluated using specimens obtained from classic murine models of liver fibrosis, namely wild-type (WT) and TRPM8-/- (KO) fibrotic mice after carbon tetrachloride (CCl4) or bile duct ligation (BDL) treatment. The role of TRPM8 was systematically evaluated using specimens obtained from the aforementioned animal models after various in vivo and in vitro experiments. RESULTS: Clinicopathological analysis showed that TRPM8 expression was upregulated in tissue samples from cirrhosis patients and fibrotic mice. TRPM8 deficiency not only attenuated inflammation and fibrosis progression in mice but also helped to alleviate symptoms of cholangiopathies. Moreover, reduction in S100A9 and increase in HNF4α expressions were observed in liver of CCl4- and BDL- treated TRPM8-/- mice. A strong regulatory linkage between S100A9 and HNF4α was also noticed in L02 cells that underwent siRNA-mediated S100A9 knockdown and S100A9 overexpressing plasmid transfection. Lastly, the alleviative effect of a selective TRPM8 antagonist was confirmed in vivo. CONCLUSIONS: These findings suggest TRPM8 deficiency may exert protective effects against inflammation, cholangiopathies, and fibrosis through S100A9-HNF4α signaling. M8-B might be a promising therapeutic candidate for liver fibrosis.

Identification of two immune-related risk score signatures through integrated analysis of multi-omics data in hepatocellular carcinoma.

Hepatocellular carcinoma (HCC) is one of the leading causes of cancer-related death worldwide. Immunotherapy has become a major treatment for advanced HCC, but the therapeutic effects remain unsatisfactory. In this study, we constructed an immune cell risk score (ICS) and an immune cell-related gene risk score (ICRGS) for the prognosis prediction of HCC through integrated analysis of bulk and single-cell RNA (scRNA) sequencing data. These two risk score signatures both showed good predictive values in the training and validation cohorts. The potential interactions among these prognostic immune cell types were elucidated by cell-cell communication analysis. The results of enrichment analysis and gene set enrichment analysis (GSEA) of the prognostic genes showed that metabolic-related processes were involved in the immune response of HCC. Furthermore, the results of correlation analyses further confirmed the hub genes that were strongly correlated with immune cells. Finally, potential therapeutic drugs targeting these hub genes were screened by CellMiner based on NCI-60 cell line set. Taken together, two useful models for the prognosis prediction of HCC patients were constructed in this study. The functional differences between the two groups of HCC patients separated by ICS or ICRGS provide fundamental knowledge for finding synergistic therapeutic targets for HCC immunotherapy.

Inhibition of the transient receptor potential vanilloid 3 channel attenuates carbon tetrachloride-induced hepatic fibrosis.

Transient receptor potential vanilloid 3 (TRPV3) is a member of the TRP superfamily. Previous studies have demonstrated that TRPV3 is associated with myocardial fibrosis. However, the role of TRPV3 in hepatic fibrosis and its underlying mechanisms are still unclear. This study aimed to elucidate the underlying effects of TRPV3 on hepatic fibrosis at multiple biological levels. First, immunohistochemical staining was performed to examine TRPV3 expression in human hepatic cirrhosis tissues. Then, we established a CCl4-induced hepatic fibrosis mouse model. The TRPV3 selective agonist drofenine and its inhibitor, forsythoside B, were intraperitoneally injected to investigate the relationship between TRPV3 and liver fibrosis progression. Finally, in vitro studies were performed using hepatic stellate cells (HSCs) to discover the potential molecular biological mechanisms. Immunohistochemistry revealed TRPV3 overexpression in liver cirrhosis. In the liver fibrosis groups, TRPV3 inhibitor treatment significantly reduced liver fibrosis, while TRPV3 agonist exacerbated its progression. In HSCs, knocking down TRPV3 with siRNA impaired DNA synthesis and cell proliferation and increased cell apoptosis. Furthermore, we found that knockdown of TRPV3 could reduce the lectin like oxidized lowdensity lipoprotein receptor-1 (LOX-1) protein levels. Our research suggests that lower expression or functional levels of TRPV3 can ameliorate the inflammatory response and fibrotic tissue proliferation.

Identification of the hub gene BUB1B in hepatocellular carcinoma via bioinformatic analysis and in vitro experiments.

BACKGROUND: Hepatocellular carcinoma (HCC) is one of the most commonly diagnosed cancers and the fourth leading cause of cancer-related deaths in the world. Although the treatment of HCC has made great progress in recent years, the therapeutic effects on HCC are still unsatisfactory due to difficulty in early diagnosis, chemoresistance and high recurrence rate post-surgery. METHODS: In this study, we identified differentially expressed genes (DEGs) based on four Gene Expression Omnibus (GEO) datasets (GSE45267, GSE98383, GSE101685 and GSE112790) between HCC and normal hepatic tissues. A protein-protein interaction (PPI) network was established to identify the central nodes associated with HCC. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis of the central nodes were conducted to find the hub genes. The expression levels of the hub genes were validated based on the ONCOMINE and Gene Expression Profiling Interactive Analysis (GEPIA) databases. Additionally, the genetic alterations of the hub genes were evaluated by cBioPortal. The role of the hub genes on the overall survival (OS) and relapse survival (RFS) of HCC patients was evaluated by Kaplan-Meier plotter. At last, the mechanistic role of the hub genes was illustrated by in vitro experiments. RESULTS: We found the following seven hub genes: BUB1B, CCNB1, CCNB2, CDC20, CDK1, MAD2L1 and RRM2 using integrated bioinformatics analysis. All of the hub genes were significantly upregulated in HCC tissues. And the seven hub genes were associated with the OS and RFS of HCC patients. Finally, in vitro experiments indicated that BUB1B played roles in HCC cell proliferation, migration, invasion, apoptosis and cell cycle by partially affecting mitochondrial functions. CONCLUSIONS: In summary, we identified seven hub genes that were associated with the expression and prognosis of HCC. The mechanistic oncogenic role of BUB1B in HCC was first illustrated. BUB1B might play an important role in HCC and could be potential therapeutic targets for HCC.

Camellia oil (Camellia oleifera Abel.) attenuates CCl4-induced liver fibrosis via suppressing hepatocyte apoptosis in mice.

Liver fibrosis is a common part of the pathological development of many chronic liver diseases. As liver fibrosis progresses, it may lead to cirrhosis, portal hypertension, liver decompensation, liver tumours, and death. Camellia oil (Camellia oleifera Abel.) is widely used as an edible oil in China. It has a wide range of biological activities and is used as a traditional medicine to treat conditions such as burns and stomach pains. However, whether camellia oil can ameliorate liver fibrosis remains unclear. We constructed a liver fibrosis model induced by carbon tetrachloride (CCl4) and then confirmed the role of camellia oil in liver fibrosis by biochemical examination, histopathological morphology, immunohistochemistry, and western blot analysis. We found that camellia oil ameliorated histopathological lesions, improved liver function and antioxidant capacity, decreased the expression of TGF-ß1 and α-SMA proteins, and downregulated the expression of the pro-apoptotic proteins in CCl4-induced liver fibrosis. Therefore, these results suggest that camellia oil attenuates CCl4-induced liver fibrosis in mice, and its mechanism may function via reduction of hepatocyte apoptosis to inhibit hepatic stellate cell (HSC) activation. Camellia oil may provide a potential new treatment for liver fibrosis as an auxiliary treatment by addition of the edible oil to the daily diet.

Pharmacological Inhibition of Transient Receptor Potential Vanilloid 4 (TRPV4) Channel Alleviates Carbon Tetrachloride-Induced Liver Fibrosis in Mice.

BACKGROUND: Transient receptor potential vanilloid 4 (TRPV4) is a member of the TRP channel family and is involved in diverse physiological and pathological processes. Accumulating evidence from in vitro studies indicates that TRPV4 has a potential role in liver fibrosis, but its precise role in the pathophysiological development of this condition is unclear. Exogenous interventions and endogenous reactions should be considered. METHODS: This study used a mouse model of carbon tetrachloride (CCl4)-induced liver fibrosis to investigate the effects of intraperitoneal injection of the novel TRPV4 channel selective agonist GSK1016790A (GSK) and antagonist HC-067047 (HC). RESULTS: As compared with the CCl4 group, collagen fiber deposition and alpha-smooth muscle actin (α-SMA) levels were markedly higher and hepatic lobule disorganization was worse in the CCl4+GSK group, while collagen fiber deposition was significantly lower and hepatic lobule disorganization was less severe in the CCl4+HC group. CONCLUSIONS: The present findings suggest that activation of TRPV4 channels worsens liver fibrosis and that inhibition of TRPV4 channels may alleviate liver fibrosis in vivo.

Targeting TRPV1 on cellular plasticity regulated by Ovol 2 and Zeb 1 in hepatocellular carcinoma.

The landscape of cellular plasticity and sources with relevant niche signals in hepatocellular carcinoma is still obscure. Transient receptor potential vanilloid 1 (TRPV1), a non-selective cation channel, is involved in a variety of malignancies and overexpressed in hepatocellular carcinoma (HCC). We have investigated the role of TRPV1 in HCC from different angles by various experimental techniques, such as in vivo and in vitro experiments, and by bioinformatics analysis of data from genetic models induced by diethylnitrosamine (DEN), mice samples and human HCC samples. We find that TRPV1 knockout promotes to hepatocarcinogenesis and deconstructs the portal triad adjacent to tumor border that is contributed by originations of tumor initiating cells and biliary cells. Epithelial to mesenchymal transition (EMT) is involved and transcription factors Ovol2 and Zeb1 coordinated with Sox 10 drive gene expression in the event which is also confirmed by the expression of these proteins in human HCC samples. Treatment with TRPV1 agonist Capsaicin inhibits the growth of HCC cells in xenograft models. Our findings demonstrate that TRPV1 is a potential therapeutic target in human HCC and exerts effects on cellular plasticity with modulation of Ovol2, Zeb1 and Sox10.

Transient receptor potential vanilloid-type 2 targeting on stemness in liver cancer.

The malignant phenotype of the cells resulting from human liver cancer is driven by liver cancer stem-like cells (LCSLCs). Transient Receptor Potential Vanilloid-type 2 channel (TRPV2) contributes to the progression of different tumor types, including liver cancer. In the current study, the TRPV2 expression levels give rise to the effect on stemness in liver cancer cell lines. TRPV2 knockdown in HepG2 cells enhanced spheroid and colony formation, and expression levels of CD133, CD44 and ALDH1 whereas the opposite effects were observed in TRPV2 enforced expression in SMMC-7721 cells. Furthermore, TRPV2 overexpression restored inhibition of spheroid and colony formation, and stem cell markers expression in HepG2 cells with TRPV2 silencing. The addition of the TRPV2 agonist probenecid and the TRPV2 antagonist tranilast suppressed and/or increased in vitro spheroid and colony formation, and stem cell marker expression of LCSLCs and/or liver cancer cell lines, respectively. Notably, probenecid and tranilast significantly inhibited or promoted tumor growth of HepG2 xenografts in the severe combined immunodeficiency (SCID) mouse model, respectively. TRPV2 expression at protein levels revealed converse correlation with those of CD133 and CD44 in human hepatocellular carcinoma (HCC) tissue. Collectively, the data demonstrate that TRPV2 exert effects on stemness of liver cancer and is a potential target in the treatment of human liver cancer patients.

Pharmacological inhibition of TRPV4 channel suppresses malignant biological behavior of hepatocellular carcinoma via modulation of ERK signaling pathway.

TRPV4 (transient receptor potential vanilloid 4), a member of the TRP superfamily, has been reported to correlate with several different forms of cancers. However, the role of TRPV4 in human hepatocellular carcinoma (HCC) remains unclear. The present study demonstrated that elevated expression of TRPV4 was shown in HCC tumor tissues when compared with paired non-tumoral livers both in protein and mRNA levels. Furthermore, the enhanced expression of TRPV4 was highly associated with histological grade (P = 0.036) and the number of tumors (P = 0.045). Pharmacological inhibition of TRPV4 channels in HCC cells with the specific antagonist HC-067047 suppressed cell proliferation, induced apoptosis and decreased the migration capability by attenuating the epithelial-mesenchymal transition (EMT) process in vitro. The p-ERK expression was apparently repressed after treatment with the TRPV4 antagonist, further blockade of the ERK pathway with U0126 could significantly aggravate HCC cells apoptosis. In NOD-SCID mouse xenograft models, intraperitoneal injection of HC-067047 could obviously suppress tumor growth and induce apoptosis in vivo. Together, our studies showed that the antitumor effects caused by TRPV4 channel inhibition in HCC cell lines might be attributed to the suppression of EMT process and inactivation of p-ERK which induced subsequent cell apoptosis. Thus, pharmacological inhibition of TRPV4 channel may be an option for HCC treatment.

Splenectomy after partial hepatectomy accelerates liver regeneration in mice by promoting tight junction formation via polarity protein Par 3-aPKC.

AIMS: Several experimental studies have demonstrated that removal of the spleen accelerates liver regeneration after partial hepatectomy. While the mechanism of splenectomy promotes liver regeneration by the improvement of the formation of tight junction and the establishment of hepatocyte polarity is still unknown. MAIN METHODS: We analyzed the cytokines, genes and proteins expression between 70% partial hepatectomy mice (PHx) and simultaneous 70% partial hepatectomy and splenectomy mice (PHs) at predetermined timed points. KEY FINDINGS: Compared with the PHx group mice, splenectomy accelerated hepatocyte proliferation in PHs group. The expression of Zonula occludens-1 (ZO-1) indicated that splenectomy promotes the formation of tight junction during liver regeneration. TNF-α, IL-6, HGF, TSP-1 and TGF-ß1 were essential factors for the formation of tight junction and the establishment of hepatocytes polarity in liver regeneration. After splenectomy, Partitioning defective 3 homolog (Par 3) and atypical protein kinase C (aPKC) regulate hepatocyte localization and junctional structures in regeneration liver. SIGNIFICANCE: Our data suggest that the time course expression of TNF-α, IL-6, HGF, TSP-1, and TGF-ß1 and the change of platelets take part in liver regeneration. Combination with splenectomy accelerates liver regeneration by improvement of the tight junction formation which may help to establish hepatocyte polarity via Par 3-aPKC. This may provide a clue for us that splenectomy could accelerate liver regeneration after partial hepatectomy of hepatocellular carcinoma and living donor liver transplantation.