H4-methylation regulators mediated epitranscriptome patterns and tumor microenvironment infiltration characterization in hepatocellular carcinoma.

Epigenetic modifications are involved in the remodeling of the tumor microenvironment (TME) and the regulation of immune response. Nonetheless, the role of histone H4 methylation (H4M) modification in the TME and immune regulation of hepatocellular carcinoma (HCC) is unknown. As a result, the purpose of this research is to discover H4M-mediated modification patterns and their effects on TME and immunologic characteristics in HCC. A total of 2305 samples were enrolled from 13 different cohorts. With the help of consensus clustering analysis, three distinct H4M modification patterns were identified. The cell-infiltrating characteristics of TME under these three patterns were highly consistent with their enriched biological processes and clinical outcome. The H4Mscore was then created using principal component analysis algorithm to quantify the H4M modification pattern of each individual tumor and was systematically correlated with representative tumor characteristics. We found that analyzing H4M modification patterns within individual tumors could predict TME infiltration, homologous recombination deficiency (HRD), intratumor heterogeneity, proliferation activity, mRNA stemness index, and prognosis. The group with a low H4Mscore had an inflamed TME phenotype and a better immunotherapy response, as well as a better survival outcome. The prognostic value of H4Mscore was validated in three internal cohorts and five external cohorts, respectively. In external immunotherapy cohorts, the low H4Mscore was also linked to an enhanced response to anti-PD-1/L1 and anti-CTLA4 immunotherapy and a better prognosis. This study revealed that H4M modification played an important role in forming TME diversity and complexity. Evaluating the H4M modification pattern of individual tumors could help us learn more about TME and develop more effective immunotherapy strategies.

Multiomics analyses and machine learning of nuclear receptor coactivator 6 reveal its essential role in hepatocellular carcinoma.

Nuclear receptor coactivator 6 (NCOA6), a coactivator of numerous nuclear receptors and transcription factors, regulates multiple critical cellular functions. Nuclear receptor coactivator 6 is dysregulated in various cancers, including hepatocellular carcinoma (HCC); however, its role remains largely unknown. Here we reported that NCOA6 was highly expressed in HCC compared to the adjacent liver tissue, and NCOA6 overexpression was significantly correlated with poor HCC prognosis. Experiments revealed that the knockdown of NCOA6 damaged the proliferation, migration, and invasion of HCC cells. Multiomics and immune infiltration analyses showed a close relationship between NCOA6 expression, multiple cancer-related malignant pathways, and the immunosuppressive microenvironment. Finally, we established an effective NCOA6-related microRNA (miRNA) signature to distinguish HCC from hepatitis\liver cirrhosis patients. To the best of our knowledge, this study is the first to provide a comprehensive analysis of NCOA6 expression in HCC. We found that NCOA6 plays an important role in HCC development and has a potential mechanism of action. Establishing an NCOA6-related miRNA signature will help develop novel diagnostic strategies for HCC patients.

TGF-ß1 induced deficiency of linc00261 promotes epithelial-mesenchymal-transition and stemness of hepatocellular carcinoma via modulating SMAD3.

Emerging evidence suggests that long non-coding RNAs (lncRNAs) play important roles in the metastasis and recurrence of hepatocellular carcinoma (HCC). A kinds of lncRNAs were found to be involved in regulating epithelial-mesenchymal transition (EMT) or stem-like traits in human cancers, however, the molecular mechanism and signaling pathways targeting EMT and stemness remains largely unknown. Previously, we found that linc00261 was down-regulated in HCC and associated with multiple worse clinical pathological parameters and poor prognosis. Here, we show that linc00261 was down-regulated in TGF-ß1 stimulated cells, and forced expression of linc00261 attenuated EMT and stem-like traits in HCC. Linc00261 also inhibited the tumor sphere forming in vitro and decreased the tumorigenicity in vivo. Furthermore, we revealed that linc00261 suppressed the expression and phosphorylation of SMAD3 (p-SMAD3), which could be core transcriptional modulator in TGF-ß1 signaling mediated EMT and the acquisition of stemness traits. A negative correlation between linc00261 and p-SMAD3 was determined in HCC samples. Conclusion: Our study revealed that linc00261 suppressed EMT and stem-like traits in HCC cells by inhibiting TGF-ß1/SMAD3 signaling.

Epigenetically silenced linc00261 contributes to the metastasis of hepatocellular carcinoma via inducing the deficiency of FOXA2 transcription.

Hepatocellular carcinoma (HCC) is one of the most common malignancies worldwide. In recent decades, long non-coding RNAs (lncRNAs) have attracted increasing attention and have been reported to play important roles in human cancers, making them ideal candidates for precise disease assessment and treatment. Our previous study found that the loss of linc00261 was significantly correlated with the malignant biological behaviors of HCC, particularly MVI, and serves as an excellent independent prognostic factor for recurrence-free survival. In this study, our in-depth research demonstrated that linc00261 inhibits epithelial-mesenchymal transition (EMT) in liver cancer cells, thereby suppressing migration, invasion, and the formation of lung metastatic lesions. Moreover, linc00261 and its neighbor gene FOXA2 were positively correlated in HCC, the gain- and loss-of-function analyses indicated that linc00261 transcriptionally promotes the expression of FOXA2. Additionally, bioinformatic analysis and rescue assays confirmed that linc00261 partially suppresses migration, invasion, and EMT by upregulating FOXA2 expression. Molecular mechanism studies showed that linc00261 transcriptionally upregulates FOXA2 in cis by recruiting SMAD3. Finally, we identified EZH2 is responsible for linc00261 transcription repression via modulating trimethylation of H3K27 at Lys27 (H3K27Me3), both EZH2 and H3K27Me3 were negatively correlated with linc00261 expression in HCC. In conclusion, these findings demonstrated a crucial role of linc00261 in HCC metastasis, and that EZH2/linc00261/FOXA2 axis might reveal potential prognostic factors and be applied as therapeutic targets for HCC metastasis.

Frizzled 2-induced epithelial-mesenchymal transition correlates with vasculogenic mimicry, stemness, and Hippo signaling in hepatocellular carcinoma.

Prior observation has indicated that Frizzled 2 (FZD2)-induced epithelial-mesenchymal transition (EMT) could be a key step in metastasis and early recurrence of hepatocellular carcinoma (HCC). However, the mechanism underlying tumor development and progression due to aberrant FZD2 expression is poorly defined. Here, we provide evidence that FZD2 is a driver for EMT, cancer stem cell properties, and vasculogenic mimicry (VM) in HCC. We found that FZD2 was highly expressed in two cohorts of Chinese hepatitis B virus-related HCC patients, and that high FZD2 expression was associated with poor prognosis. Concerning the mechanism, gain- and loss-of-function experiments showed the oncogenic action of FZD2 in HCC cell proliferation, apoptosis, migration, and invasion. Further investigations in vitro and in vivo suggested that FZD2 promotes the EMT process, enhances stem-like properties, and confers VM capacity to HCC cells. Notably, integrative RNA sequencing analysis of FZD2-knockdown cells indicated the enrichment of Hippo signaling pathway. Taken together, our data suggest for the first time that FZD2 could promote clinically relevant EMT, CD44+ stem-like properties, and the VM phenotype in HCC involving a potential Hippo signaling pathway-dependent mechanism, and should be considered as a promising therapeutic target for the treatment of HCC.

[Expression of long noncoding RNA linc00261 in hepatocellular carcinoma and its association with postoperative outcomes].

OBJECTIVE: To investigate the expression of long noncoding RNA linc00261 in hepatocellular carcinoma (HCC) and its correlation with the clinicopathological features and postoperative outcomes of the patients. METHODS: Real-time fluorescence quantitative PCR (qRT-PCR) was used to detect the expression of linc00261 in surgical specimens of HCC and adjacent tissues from 74 patients. The correlation of the expression level of linc00261 in HCC with the clinicopathological parameters of the patients was analyzed using Chi-square test. The Cox's proportional hazards regression model was used to assess the value of linc00261 in predicting the prognosis of HCC patients after operation. The expression of linc00261 was also examined in 5 HCC cell lines using qRT-PCR. The HCC cell lines MHCC-LM3 and SNU-449 were transfected with small interfering RNAs targeting linc00261 for linc00261 knockdown, and the changes in the cell proliferation, migration and invasion abilities were observed using CCK-8 assay and Transwell assay. RESULTS: The expression level of linc00261 in HCC was significantly correlated with AFP (P=0.032), tumor size (P=0.007), microscopic vascular invasion (MVI; P=0.01), and TNM stage (P=002). The patients with lowered expressions of linc00261 in HCC tissues had a significantly shortened tumor-free survival time (P < 0.05), and a lowered expression of linc00261 was identified as an independent risk factor affecting postoperative recurrence-free survival time of the patients (P < 0.05). In HCC cell lines MHCC-LM3 and SNU-449 cells, linc00261 knockdown obviously promoted the cell migration and invasion (P < 0.01) but did not significantly affect cell proliferation (P > 0.05). CONCLUSIONS: Linc00261 may serve as a new prognostic biomarker for predicting the postoperative outcomes of the patients with HCC.

Circulating Tumor Cell Phenotype Indicates Poor Survival and Recurrence After Surgery for Hepatocellular Carcinoma.

BACKGROUND: Circulating tumors cells (CTCs) may be a promising prognostic marker for patients with malignant tumors. However, there are few reports regarding its value for hepatocellular carcinoma (HCC) patients. AIMS: To investigate CTCs with epithelial and mesenchymal phenotypes as a potential prognostic biomarker for HCC patients. METHODS: Peripheral blood samples were obtained from 165 HCC patients before radical surgery. CTCs were isolated via the CanPatrol CTC enrichment technique and classified using epithelial-mesenchymal transition (EMT) markers. The relationship of CTC phenotype with clinicopathological factors and HCC recurrence in patients was analyzed. RESULTS: CTC-positive status (count ≥ 2/5 mL) was found in 70.9% of the 165 HCC patients. Increased CTC number was more common in patients with higher AFP levels, multiple tumors, advanced TNM and BCLC staging, and presence of embolus or microembolus (P < 0.05). CTCs heterogeneity was noted using EMT markers. Mesenchymal CTCs were significantly correlated with high AFP levels, multiple tumors, advanced TNM and BCLC stage, presence of embolus or microembolus, and earlier recurrence (P < 0.05). The presence of mesenchymal CTCs predicted the shortest relapse-free survival, followed by mixed phenotypic CTCs, and then epithelial CTCs (P < 0.001). CONCLUSION: CTC phenotype may serve as a prognostic indicator for HCC patients. CTCs assessment should include phenotypic identification tailored to characterize cells based on epithelial and mesenchymal markers.

[Expression of Wnt5b in patients with HBV-related hepatocellular carcinoma and its clinical significance].

OBJECTIVE: To investigate the expression of Wnt5b in hepatitis B virus (HBV)-related hepatocellular carcinoma (HCC) tissues and its correlation with the clinicopathological parameters. METHODS: Quantitative real-time polymerase chain reaction (qRT-PCR) and immunohistochemical staining were employed to measure Wnt5b mRNA and protein expressions in two groups of HBV-related HCC patients (100 cases in each) selected from a cohort of 289 cases with HBV-related HCC using simple random sampling method. The correlation of Wnt5b expression with the clinicopathological parameters and the prognosis of HCC patients was analyzed. RESULTS: Wnt5b mRNA expression was significantly higher in HCC tissues than that of adjacent noncancerous tissues in 65.0% (65/100) of the cases, and the positivity rate of Wnt5b protein was significantly higher in HCC tissues than that of adjacent noncancerous tissues (58.0% vs 22.0%, P<0.05). Wnt5b expression was significantly correlated with the tumor size (P<0.05), tumor number (P<0.01, only at the protein level), tumor differentiation (P<0.01, only at the protein level), TNM stage (P<0.05), BCLC stage (P<0.05), metastasis (P<0.05) and recurrence (P<0.01). The patients with up-regulated Wnt5b mRNA and protein had a shorter relapse-free survival (P<0.01). CONCLUSION: s Up-regulated Wnt5b might contribute to the progression of HBV-related HCC and predicts a poor prognosis.