PRMT9 promotes hepatocellular carcinoma invasion and metastasis via activating PI3K/Akt/GSK-3β/Snail signaling.

Protein arginine methyltransferases (PRMT) catalyze protein arginine methylation and play an important role in many biological processes. Aberrant PRMT expression in tumor cells has been documented in several common cancer types; however, its precise contribution to hepatocellular carcinoma (HCC) cell invasion and metastasis is not fully understood. In this study, we identified a new oncogene, PRMT9, whose overexpression strongly promotes HCC invasion and metastasis. PRMT9 expression was detected more frequently in HCC tissues than in adjacent noncancerous tissues. PRMT9 overexpression was significantly correlated with hepatitis B virus antigen (HBsAg) status, vascular invasion, poor tumor differentiation and advanced TNM stage. Patients with higher PRMT9 expression had a shorter survival time and higher recurrence rate. PRMT9 expression was an independent and significant risk factor for survival after curative resection. Functional studies demonstrated that PRMT9 increased HCC cell invasion and lung metastasis. Knocking down PRMT9 with short hairpin RNA (shRNA) inhibited HCC cell invasion. Further investigations found that PRMT9 increased cell migration and invasion through epithelial-mesenchymal transition (EMT) by regulating Snail expression via activation of the PI3K/Akt/GSK-3β/Snail signaling pathway. In clinical HCC samples, PRMT9 expression was positively associated with Snail expression and was negatively associated with E-cadherin expression. In conclusion, our study demonstrated that PRMT9 is an oncogene that plays an important role in HCC invasion and metastasis through EMT by regulating Snail expression via activation of the PI3K/Akt/GSK-3β/Snail signaling pathway. Thus, PRMT9 may serve as a candidate prognostic biomarker and a potential therapeutic target.

Jiang H ，Zhou Z ，Jin S ，Xu K ，Zhang H ，Xu J ，Sun Q ，Wang J ，Xu J ... -  《-》

HTR1D regulates the PI3K/Akt signaling pathway to impact hepatocellular carcinoma development and resistance to sorafenib.

Hepatocellular carcinoma (HCC) has a poor prognosis, partly due to resistance to treatments like sorafenib. The 5-hydroxytryptamine receptor 1D (HTR1D) is involved in cancer progression through the PI3K/Akt pathway, but its role in HCC is not well understood. This study investigates HTR1D's expression, function, and potential as a prognostic marker in HCC. First, the correlation between HTR1D and hepatocellular carcinoma was analyzed using the TCGA database, and the expression level of HTR1D in clinical samples was detected by qPCR. Then the siRNA was transfected into Huh-7 and Hep3B cells, and the cell proliferation ability, colony formation ability, migration and invasion ability were detected with or without sorafenib. And the expression of the PI3K/Akt pathway was detected by Western Blot. Finally, the potential of HTR1D as a predictive marker for patient prognosis was evaluated by immunohistochemistry. Analysis of TCGA data showed that methylation of the HTR1D gene was associated with cancer status. Clinical samples confirmed significant differences in HTR1D expression between HCC and adjacent tissues, with higher expression correlating with poorer patient prognosis. Interference with HTR1D gene expression demonstrated its role in promoting HCC proliferation, migration, and drug resistance through the PI3K/Akt pathway. These findings were validated in a mouse model. Immunohistochemical analysis of clinicopathological samples suggested that HTR1D could be a valuable prognostic marker for HCC. HTR1D is highly expressed in hepatocellular carcinoma tissues, and it can influence hepatocellular carcinoma development and resistance to sorafenib by regulating the PI3K/Akt signaling pathway. In addition, HTR1D has potential as a prognostic indicator.

Zhang Y ，Zhang Y ，Zhou S ，Rehman MU ，Lin F ，Zhang J ，Zhou H ... -  《BMC CANCER》

Britannin inhibits hepatocellular carcinoma development and metastasis through the GSK-3β/β-catenin signaling pathway.

Hepatocellular carcinoma (HCC) stands out as a significant contributor to cancer-related death. Traditional Chinese Medicine (TCM) offers several advantages in the treatment of HCC. Britannin, a pivotal compound in Inulae Flos, has demonstrated pharmacological effects against various cancers, yet research on its specific anti-HCC effects remains limited. This study aims to explore the anti-HCC effects of britannin and its underlying mechanism. MTT assay, clone formation assay and flow cytometry were utilized to detect the cell activity, proliferation ability and apoptosis of britannin against HCC cell lines. Cell migration and invasion abilities of HCC cell lines treated with britannin were evaluated by wound-healing assay and transwell migration and invasion assay. H22 xenografted tumor mouse model was constructed and britannin treatment was performed to observe the effect of britannin on HCC tumors. The expression levels of liver cancer biomarkers AFP, AFP-L3, APT and TGF-β were detected by Elisa, and the histopathology was observed by HE staining. Network pharmacology and molecular docking were used to predict the possible signaling pathway of anti-HCC effect of britannin. The surface plasmon resonance (SPR) experiment was used to verify the interaction between britannin and proteins. The cell kinase activity function experiment was employed to detect the effect of britannin on enzyme activity. RT-qPCR and Western-Blot were used to verify the effect of britannin on the mRNA expressions of key genes and protein levels related to GSK-3β/β-catenin pathway in HCC cells and tumor tissues in mice. In vitro experiments showed that britannin could inhibit the activity, proliferation, migration and invasion abilities of HCC cells, while promoting their apoptosis. In vivo experiments revealed that britannin exerted inhibitory effects on the growth of transplanted liver cancer tumors, reducing the inflammatory infiltration and the expression levels of AFP, AFP-L3, APT and TGF-β of liver cancer markers in transplanted mice. Network pharmacology and molecular docking predicted that cell adhesion factors and GSK-3β/β-catenin pathway might be the related signaling pathway and had potential docking activity with key proteins. The SPR experiments elucidated the molecular interaction between britannin and GSK-3β. Enzyme activity assays indicated that britannin could modulate the functional activity of GSK-3β kinase. RT-qPCR suggested britannin could regulate the mRNA expressions of β-catenin, GSK-3β, E-cadherin and NCadherin. Western-Blot further verified that britannin could significantly up-regulate the expression of GSK-3β and down-regulate the expression of p-GSK-3β and β-catenin. At the same time, the expression of E-cadherin increased and NCadherin decreased, thereby reducing the occurrence of EMT and inhibiting the metastasis of HCC. In conclusion, britannin could inhibit the growth, development and metastasis of HCC, and its mechanism may be related to the regulation of GSK-3β/β-catenin signaling pathway to inhibit epithelial-mesenchymal transition of HCC.

Lu Q ，Zhu J ，Teng L ，Chen C ，Bi L ，Chen W ... -  《-》

RNA-binding protein Trx regulates alternative splicing and promotes metastasis of HCC via interacting with LINC00152.

Epithelial-mesenchymal transition (EMT) is central to HCC metastasis, in which RNA-binding proteins (RBPs) play a key role. To explore the role of RBPs in metastasis of hepatocellular carcinoma (HCC), whole transcriptome sequencing was conducted to identify differential RBPs between HCC with metastasis and HCC without metastasis. The influence of RBPs on metastasis of HCC was verified by in vitro and in vivo experiments. The interaction of RBPs with non-coding RNAs was evaluated by RNA immunoprecipitation and pull-down assays. RNA sequencing, whole-genome sequencing, and alternative splicing analysis were further performed to clarify post-transcriptional regulation mechanisms. Whole transcriptome sequencing results showed that expression of thioredoxin (Trx) was significantly upregulated in HCC patients with metastasis. Trx was also found to be associated with poor prognosis in HCC patients. Overexpression of Trx could promote migration and invasion of HCC cells in vitro and increase the rate of lung metastasis of HCC cells in vivo. Moreover, binding assays showed that Trx could bind to LINC00152. As a result, LINC00152 was verified to determine the pro-metastasis function of Trx by knockdown assay. Furthermore, we revealed that Trx could regulate metastasis-associated alternative splicing program. Specifically, angiopoietin 1 (ANGPT1) was the splicing target; the splicing isoform switching of ANGPT1 could activate the PI3K-Akt pathway, upregulate EMT-associated proteins, and promote migration and invasion of HCC cells. We found that Trx could interact with LINC00152 and promote HCC metastasis via regulating alternative splicing, indicating that Trx may serve as a novel therapeutic target for HCC treatment.

Teng X ，Shang J ，Du L ，Huang W ，Wang Y ，Liu M ，Ma Y ，Wang M ，Tang H ，Bai L ... -  《-》

Upregulated SAE1 Drives Tumorigenesis and Is Associated with Poor Clinical Outcomes in Breast Cancer.

The purpose of this study was to analyze SUMO activating enzyme subunit 1 (SAE1) expression in breast cancer (BC). Through bioinformatics analysis and in vitro experiments, the biological function and possibly associated signal pathways of SAE1 in BC were further analyzed. Bioinformatics analysis was applied to analyze SAE1 expression in BC and normal breast tissues, its relationship with clinicopathologic characteristics and prognosis in BC patients, and data from the Cancer Genome Atlas database and Gene Expression Omnibus dataset. We performed immunohistochemistry to analyze SAE1 expression in BC tissues and para-cancer tissues in 79 breast cancer patients. BC cell proliferation was detected with the Cell Counting Kit-8 and by the colony formation assay. Cell cycle progression was analyzed by flow cytometry, and the expression of cell cycle-related proteins (E2F1, cyclin D3, and cyclin-dependent kinase 2) was determined by western blots in SAE1 small interfering RNA (siRNA) transfected cells. The GSE1456 dataset was used to analyze possible signal pathways associated with SAE1 by gene set enrichment analysis (GSEA), and the expression of PI3K/AKT/mTOR pathway-related proteins (such as p-PI3K, p-AKT, and mTOR) in SAE1-siRNA cells was detected by western blots. The bioinformatics and immunohistochemical results showed that SAE1 mRNA and protein expression in BC tissues were significantly higher than those in normal tissues. The SAE1 overexpression was significantly associated with the tumor size, tumor-node-metastasis stage, estrogen receptor, progesterone receptor, human epidermal growth factor receptor 2, and whether or not it was a triple-negative BC. Patients with SAE1 overexpression had a worse overall survival (OS), recurrence-free survival (RFS), and distant metastasis-free survival compared with lower expression patients. Multivariate Cox regression analysis showed that SAE1 may be an independent prognostic factor for OS of BC patients. The proliferation and cell cycle process of BC cells were inhibited by SAE1-siRNA in vitro. The result of GSEA showed that SAE1 was significantly associated with 12 gene sets, including unfolded protein reaction, DNA repair, oxidative phosphorylation, and cell cycle, among others. Additionally, two signal pathways, mTORC1 and PI3K/Akt/mTOR, were significantly correlated with SAE1 overexpression. Western blots confirmed that the expression of PI3K/Akt/mTOR pathway-related proteins (p-PI3K, p-AKT, and mTOR) in BC cells was decreased after knocking down SAE1. SAE1 was highly expressed in BC. Its overexpression was associated with poor BC prognosis. Additionally, it was an independent prognostic factor for BC patients. We demonstrated that in vitro SAE1 knockdown effectively inhibited BC proliferation and its cell cycle process. Furthermore, the biological function of SAE1 may be associated with the PI3K/Akt/mTOR pathway. SAE1 will be a potential target for BC treatment.

Liu H ，Wang J ，Li Y ，Luo F ，Xing L ... -  《-》