TRIM66 promotes malignant progression of hepatocellular carcinoma by inhibiting E-cadherin expression through the EMT pathway

Recent progress in molecular mechanisms of postoperative recurrence and metastasis of hepatocellular carcinoma

Hepatectomy is currently considered the most effective option for treating patients with early and intermediate hepatocellular carcinoma (HCC). Unfortunately, the postoperative prognosis of patients with HCC remains unsatisfactory, predominantly because of high postoperative metastasis and recurrence rates. Therefore, research on the molecular mechanisms of postoperative HCC metastasis and recurrence will help develop effective intervention measures to prevent or delay HCC metastasis and recurrence and to improve the long-term survival of HCC patients. Herein, we review the latest research progress on the molecular mechanisms underlying postoperative HCC metastasis and recurrence to lay a foundation for improving the understanding of HCC metastasis and recurrence and for developing more precise prevention and intervention strategies.

TRIM proteins in hepatocellular carcinoma

The tripartite motif (TRIM) protein family is a highly conserved group of E3 ligases with 77 members known in the human, most of which consist of a RING-finger domain, one or two B-box domains, and a coiled-coil domain. Generally, TRIM proteins function as E3 ligases to facilitate specific proteasomal degradation of target proteins. In addition, E3 ligase independent functions of TRIM protein were also reported. In hepatocellular carcinoma, expressions of TRIM proteins are both regulated by genetic and epigenetic mechanisms. TRIM proteins regulate multiple biological activities and signaling cascades. And TRIM proteins influence hallmarks of HCC. This review systematically demonstrates the versatile roles of TRIM proteins in HCC and helps us better understand the molecular mechanism of the development and progression of HCC.

A Ferroptosis-Related LncRNA Signature Associated with Prognosis, Tumor Immune Environment, and Genome Instability in Hepatocellular Carcinoma

Background

Ferroptosis is an iron-dependent form of cell death. In this study, we identified ferroptosis-related long noncoding RNAs (FRlncRNAs) to investigate their association with hepatocellular carcinoma (HCC) in prognosis, tumor immune environment, and genome instability.

Methods

Transcriptome profile data of HCC were retrieved from a public database. FRlncRNAs were identified by co-expression analysis. Patients were randomly divided into training and test cohorts. Univariate Cox analysis and Least Absolute Shrinkage and Selection Operator (LASSO) Cox regression were performed to construct a risk model. Patients were divided into high- and low-risk groups based on the risk model. AUC and C index were used to assess the risk model. Survival analysis, immune status, and genome instability were compared between the two groups.

Results

Sixteen FRlncRNAs were identified and used to construct an FRlncRNA signature for the risk model. The Kaplan-Meier analysis revealed that patients in the high-risk group had poorer overall survival than patients in the low-risk group. The area under curve of the risk model was 0.879, 0.809, and 0.757 in the training cohort and 0.635, 0.688, and 0.739 in the test cohort at 1, 2, and 3 years, respectively. The risk model was an independent prognostic predictor and showed excellent prediction of prognosis compared with clinicopathological features. For the differentially expressed ferroptosis-related genes, many enriched metabolic pathways were identified in the functional enrichment analysis. Immune cells such as CD8+ T cells, macrophages M1, natural killer cells, and B cells, which may be associated with antitumor immune responses, differed between the high- and low-risk groups. Genome instability based on the risk model was also explored. A total of 61 genes were differently mutated between the two risk groups, and among them, TP53, HECW2, TRIM66, MCTP2, and KIAA1551 had the most significant mutation frequency differences.

Conclusion

The FRlncRNA signature is closely related with overall survival, tumor immune environment, and genome instability in HCC.

Identification Prognostic Value and Correlation with Tumor-Infiltrating Immune Cells of Tripartite-Motif Family Genes in Hepatocellular Carcinoma

Background

Hepatocellular carcinoma (HCC) is one of the most common and mortality types of malignant tumors in the world. The Tripartite-Motif (TRIM) protein family consists of more than 80 proteins with E3 ubiquitin ligase activity. Increasing studies have found that TRIM family proteins play an extremely important role in the occurrence and development of tumors. However, the expression and prognostic values of TRIMs in HCC have not been clarified.

Methods

We used bioinformatic methods to explore the potential function of TRIM family genes in the HCC. Web servers ONCOMINE, UALCAN, GEPIA, cBioPortal, STRING, DAVID 6.8 and TIMER were used in this research.

Results

We screened TRIM1-76 and found the expressions of TRIM6, TRIM11, TRIM16, TRIM18(MID1), TRIM24, TRIM28, TRIM31, TRIM37, TRIM45, TRIM52, TRIM59, TRIM66 were significantly changed in HCC. Among them, TRIM24, TRIM28, TRIM37, TRIM45 and TRIM59 had significant effects on pathological stages, overall survival and disease free survival. Functions of these genes are primarily related to transcriptional misregulation in cancer, p53 signaling pathway, alcoholism and viral carcinogenesis, FoxO signal pathway, PI3K-AKT pathway, cell cycle, microRNAs in cancer. Our results showed the significant correlation between TRIMs expression and infiltration of innate immune cells (macrophages, neutrophils, and dendritic cells).

Conclusion

Our result provides novel insights into the function of TRIM family genes, which may be used as potential references for drug targets and accurate survival predictions in patients with HCC.

TRIM66 promotes malignant progression of prostate carcinoma through the JAK/STAT pathway

Prostate cancer is the fifth leading cause of cancer‐related deaths in males globally. Tripartite Motif Containing 66 (TRIM66) functions as transcriptional repressor and exerts its effect at least partially through promotion of deacetylase. TRIM66 has been previously reported to play an oncogenic role in a number of human cancers. Here, we investigated the potential oncogenic properties of TRIM66 in prostate cancer. We report that shRNA‐mediated knockdown of TRIM66 significantly suppressed viability and proliferation of both PC‐3 and DU145 prostate cancer cell lines. Furthermore, TRIM66 deficiency inhibited migration and invasion of prostate cancer cells. Mechanistically, TRIM66 positively regulated signal transducer and activator of transcription 2 (STAT2) and interleukin‐2 (IL‐2) expression. The predominance of STAT2–IL‐2 in mediating the oncogenic properties of TRIM66 was determined using a rescue assay, wherein overexpression of either STAT2 or IL‐2 almost completely abolished the inhibitory effects on cell proliferation, migration and invasion elicited by TRIM66 deficiency in prostate cancer cells. Our study highlights the importance of the TRIM66–STAT2–IL‐2 signaling axis in the tumor biology of prostate cancer.

FAM172A inhibits EMT in pancreatic cancer via ERK-MAPK signaling

FAM172A, as a newly discovered gene, is little known in cancer development, especially in pancreatic cancer (PC). We investigated the potential role and molecular mechanism of FAM172A in epithelial to mesenchymal transition (EMT) in both human clinical samples and PC cells. FAM172A was downregulated in human PC tissues compared with that in non-cancerous pancreas cells by immunohistochemistry and qRT-PCR. FAM172A expression was negatively associated with tumor size (P=0.015), T stage (P=0.006), lymph node metastasis (P=0.028) and the worst prognosis of PC patients (P=0.004). Meanwhile, a positive relationship between FAM172A and E-cadherin (E-cad) (r=0.381, P=0.002) was observed in clinical samples, which contributed to the better prognosis of PC patients (P=0.014). FAM172A silencing induced EMT in both AsPC-1 and BxPC-3 cells, including inducing the increase of Vimentin, MMP9 and pERK and the decrease of E-cad and β-catenin expression, stimulating EMT-like cell morphology and enhancing cell invasion and migration in PC cells. However, MEK1 inhibitor PD98059 reversed FAM172A silencing-enhanced EMT in PC cells. We conclude that FAM172A inhibits EMT of PC cells via ERK-MAPK signaling.

Tankyrases/β-catenin Signaling Pathway as an Anti-proliferation and Anti-metastatic Target in Hepatocarcinoma Cell Lines

Objective: The Wnt/β-catenin pathway is involved in the development of hepatocellular carcinoma (HCC) and malignant events such as the epithelial-mesenchymal transition (EMT), metastasis, and invasion. Studies have illustrated that the inhibition of tankyrases (TNKS) antagonizes Wnt/β-catenin signaling in many cancer cells. Methods: The expression levels of proteins related to the Wnt/β-catenin pathway and EMT were analyzed by immunohistochemistry in HCC tissue and paired adjacent normal tissue (n = 10), and in an analysis of The Cancer Genome Atlas (TCGA) data. Additionally, after treatment of HCC cell lines with TNKS1/2 small interfering RNA (siRNA) and a novel TNKS inhibitor (NVP-TNKS656), cell viability, cell clone formation, wound-healing, and cell invasion assays were performed. Results: Higher expression of β-catenin, TNKS, vimentin, and N-cadherin was observed in HCC tissue compared to adjacent normal tissue, but lower expression of E-cadherin was found in HCC tissue. These findings were also observed in the TCGA analysis. In addition, TNKS inhibition (using TNKS1/2 siRNA and NVP-TNKS656) not only abrogated the proliferation of the HCC cell lines but also suppressed metastasis, invasion, and EMT phenotypic features. Moreover, the mechanisms related to TNKS inhibition in HCC probably involved the stabilization of AXIN levels and the downregulation of β-catenin, which mediates EMT marker expression. Conclusion: The TNKS/β-catenin signaling pathway is a potential anti-proliferation and anti-metastatic target in HCC.

NELFE promoted pancreatic cancer metastasis and the epithelial‑to‑mesenchymal transition by decreasing the stabilization of NDRG2 mRNA

Negative elongation factor E (NELFE) has been demonstrated to promote cancer progression as an RNA‑binding protein (RBP). However, the expression patterns, biological role and molecular mechanism of NELFE in pancreatic cancer (PC) remain largely unknown. The expression levels of NELFE in 120 pairs of PC tissues and adjacent non‑tumor clinical samples collected from patients with PC were examined via reverse transcription‑quantitative (RT‑q) PCR and immunohistochemistry. The mRNA expression levels of NELFE, N‑Myc downstream‑regulated gene 2 (NDRG2), c‑Myc, survivin and cyclin D1 were detected via RT‑qPCR. The protein expression levels of NELFE, NDRG2, total β‑catenin, nuclear β‑catenin, cytosolic β‑catenin, E‑cadherin, N‑cadherin and Vimentin were measured by western blotting. NELFE and NDRG2 were then knocked‑down by short hairpin (sh)RNA. PC cell proliferation was detected by MTT and colony formation assays. Invasion and migration were detected by transwell assays. The interaction between NELFE and NDRG2 was detected by luciferase reporter assays, mRNA decay assays and RNA immunoprecipitation. NELFE expression was increased in PC tissues compared with the paired non‑cancerous tissues. NELFE expression was upregulated in PC cells when compared with normal pancreatic cells (HPDE6‑C7). The present study revealed that knockdown of NELFE inhibited the proliferation, invasion and migration of PC cells. In addition, transfection of the sh‑NELFE vector inhibited the epithelial‑to‑mesenchymal transition in PC cells by suppressing the expression and nuclear accumulation of β‑catenin. Further mechanistic studies revealed that NELFE activates the Wnt/β‑catenin signaling pathway by decreasing the stabilization of NDRG2 mRNA in PC. To the best of our knowledge, these results revealed the promotional function of NELFE on PC tumorigenesis and metastasis for the first time, helping to provide a promising strategy for the treatment of patients with PC.