High mRNA Expression of CENPL and Its Significance in Prognosis of Hepatocellular Carcinoma Patients

Evolutionary analysis reveals the role of a non-catalytic domain of peptidyl arginine deiminase 2 in transcriptional regulation

Peptidyl arginine deiminases (PADIs) catalyze protein citrullination, a post-translational conversion of arginine to citrulline. The most widely expressed member of this family, PADI2, regulates cellular processes that impact several diseases. We hypothesized that we could gain new insights into PADI2 function through a systematic evolutionary and structural analysis. Here, we identify 20 positively selected PADI2 residues, 16 of which are structurally exposed and maintain PADI2 interactions with cognate proteins. Many of these selected residues reside in non-catalytic regions of PADI2. We validate the importance of a prominent loop in the middle domain that encompasses PADI2 L162, a residue under positive selection. This site is essential for interaction with the transcription elongation factor (P-TEFb) and mediates the active transcription of the oncogenes c-MYC, and CCNB1, as well as impacting cellular proliferation. These insights could be key to understanding and addressing the role of the PADI2 c-MYC axis in cancer progression.

Genetic variation is a key determinant of chromatin accessibility and drives differences in the regulatory landscape of C57BL/6J and 129S1/SvImJ mice

Most common genetic variants associated with disease are located in non-coding regions of the genome. One mechanism by which they function is through altering transcription factor (TF) binding. In this study, we explore how genetic variation is connected to differences in the regulatory landscape of livers from C57BL/6J and 129S1/SvImJ mice fed either chow or a high-fat diet. To identify sites where regulatory variation affects TF binding and nearby gene expression, we employed an integrative analysis of H3K27ac ChIP-seq (active enhancers), ATAC-seq (chromatin accessibility) and RNA-seq (gene expression). We show that, across all these assays, the genetically driven (i.e. strain-specific) differences in the regulatory landscape are more pronounced than those modified by diet. Most notably, our analysis revealed that differentially accessible regions (DARs, N = 29635, FDR < 0.01 and fold change > 50%) are almost always strain-specific and enriched with genetic variation. Moreover, proximal DARs are highly correlated with differentially expressed genes. We also show that TF binding is affected by genetic variation, which we validate experimentally using ChIP-seq for TCF7L2 and CTCF. This study provides detailed insights into how non-coding genetic variation alters the gene regulatory landscape, and demonstrates how this can be used to study the regulatory variation influencing TF binding.

Identification of the hub genes linked to zearalenone-induced hepatotoxicity in broiler chickens

Zearalenone (ZEN) is a mycotoxin found in food and feed that impairs the function of multiple organs, especially the liver. However, the specific mechanisms through which ZEN induces liver damage in broiler chickens are not well understood. Therefore, this study aimed to identify the key genes linked to the hepatotoxicity induced by ZEN exposure in broiler chickens. Gene expression data from ZEN-treated and control chicken embryo primary hepatocytes (CEPHs) were used to implement differential expression analysis. Totally, 436 differentially expressed genes (DEGs) were detected, in which 223 and 213 genes were up- and down-regulated in ZEN-treated CEPHs, respectively. Gene ontology analysis suggested that these DEGs were involved in various biological processes, including chromosome segregation, mitotic cytokinesis, mitotic cell cycle, cell division, and mitotic spindle organization. Pathway analysis showed that the DEGs were associated with p53, FoxO, ubiquitin-mediated proteolysis, cell cycle, and mismatch repair signaling pathways. Furthermore, the hub genes, including BRCA1, CDC45, CDCA3, CDKN3, CENPE, CENPF, CENPI, CENPM, CENPU, and CEP55, potentially contributed to ZEN-induced hepatotoxicity. In conclusion, our study provides the valuable insight into the mechanism underlying ZEN-induced hepatotoxicity in broiler chickens.

Functional enrichment analysis reveals the involvement of DARS2 in multiple biological pathways and its potential as a therapeutic target in esophageal carcinoma

OBJECTIVE

The enzyme Aspartyl tRNA synthetase 2 (DARS2) is a crucial enzyme in the mitochondrial tRNA synthesis pathway, playing a critical role in maintaining normal mitochondrial function and protein synthesis. However, the role of DARS2 in ESCA is unclear.

MATERIALS AND METHODS

Transcriptional data of pan-cancer and ESCA were downloaded from UCSC XENA, TCGA, and GEO databases to analyze the differential expression of DARS2 between tumor samples and normal samples, and its correlation with clinicopathological features of ESCA patients. R was used for GO, KEGG, and GSEA functional enrichment analysis of DARS2 co-expression and to analyze the connection of DARS2 with glycolysis and m6A-related genes. In vitro experiments were performed to assess the effects of interfering with DARS2 expression on ESCA cells. TarBase v.8, mirDIP, miRTarBase, ENCORI, and miRNet databases were used to analyze and construct a ceRNA network containing DARS2.

RESULTS

DARS2 was overexpressed in various types of tumors. In vitro experiments confirmed that interfering with DARS2 expression significantly affected the proliferation, migration, apoptosis, cell cycle, and glycolysis of ESCA cells. DARS2 may be involved in multiple biological pathways related to tumor development. Furthermore, correlation and differential analysis revealed that DARS2 may regulate ESCA m6A modification through its interaction with METTL3 and YTHDF1. A ceRNA network containing DARS2, DLEU2/has-miR-30a-5p/DARS2, was successfully predicted and constructed.

CONCLUSIONS

Our findings reveal the upregulation of DARS2 in ESCA and its association with clinical features, glycolysis pathway, m6A modification, and ceRNA network. These discoveries provide valuable insights into the molecular mechanisms underlying ESCA.

Overexpression of CENPL mRNA potentially regulated by miR-340-3p predicts the prognosis of pancreatic cancer patients

BACKGROUND

In our previous study it was found that CENPL was overexpressed in hepatocellular carcinoma and significantly predicted patient's prognosis. However, the expression and prognostic value of CENPL in other gastrointestinal tumors remain unknown. Therefore, we investigated the expression and prognostic value of CENPL in esophageal carcinoma (ESCA), stomach adenocarcinoma (STAD), pancreatic adenocarcinoma (PAAD), colon adenocarcinoma (COAD) and rectum adenocarcinoma (READ).

METHODS

In this study, Oncomine, GEPIA, OncoLnc, TIMER, cBioPortal, miRWalk and ENCORI databases were used to analyze the level of CENPL mRNA, prognostic value and potential regulatory mechanism of CENPL mRNA in tumors. The CENPL expression and clinicopathological data regarding PAAD were from the UCSC Xena database and univariate and multivariate Cox regression analyses were performed using R (Version 3.6.3). Immunohistochemical staining was used to verify the expression of CENPL protein in clinical specimens. Cytoscape (Version: 3.7.2) was used to visualize microRNA (miRNA) that potentially regulates CENPL.

RESULTS

Gene differential expression analysis showed that CENPL mRNA was significantly overexpressed in ESCA, STAD, PAAD, COAD and READ (p < 0.01). The overexpression of CENPL mRNA was significantly correlated with the poor prognosis of PAAD patients (p < 0.05). However, there was no significant correlation between the level of CENPL mRNA and the prognosis of ESCA, STAD, COAD and READ patients (p > 0.05). Univariate and multivariate Cox regression analyses suggested that CENPL was a prognostic risk factor for PAAD. The mutation rate of CENPL in PAAD was 2.2% (17/850). There was no significant correlation between the CENPL expression and the infiltration levels of immune cells in PAAD (|Cor|< 0.5). Immunohistochemical staining showed that CENPL was overexpressed in 42% (11/26) of PAAD specimens, which was significantly higher compared with that in the normal tissues. The expression of miR-340-3p and miR-484 in PAAD were significantly lower than in the normal tissues (p < 0.05) and PAAD patients with lower expression of miR-340-3p had poorer prognosis (p < 0.05).

CONCLUSION

CENPL potentially regulated by miR-340-3p, is overexpressed in PAAD and predicts patient's prognosis, suggestive of a diagnostic and prognostic value in PAAD patients.

A positive feedback loop of CENPU/E2F6/E2F1 facilitates proliferation and metastasis via ubiquitination of E2F6 in hepatocellular carcinoma

Centromere protein U (CENPU), a centromere-binding protein required for cellular mitosis, has been reported to be closely associated with carcinogenesis in multiple malignancies; however, the role of CENPU in hepatocellular carcinoma (HCC) is still unclear. Herein, we investigated its biological role and molecular mechanism in the development of HCC. High CENPU expression in HCC tissue was observed and correlated positively with a poor prognosis in HCC patients. CENPU knockdown inhibited the proliferation, metastasis, and G1/S transition of HCC cells in vivo and in vitro, while ectopic expression of CENPU exerted the opposite effects. Mechanistically, CENPU physically interacted with E2F6 and promoted its ubiquitin-mediated degradation, thus affecting the transcription level of E2F1 and further accelerating the G1/S transition to promote HCC cell proliferation. E2F1 directly binds to the CENPU promoter and increases the transcription of CENPU, thereby forming a positive regulatory loop. Collectively, our findings indicate a crucial role for CENPU in E2F1-mediated signalling for cell cycle progression and reveal a role for CENPU as a predictive biomarker and therapeutic target for HCC patients.

Abnormal Expression of Centromere Protein U Is Associated with Hepatocellular Cancer Progression

Background

Hepatocellular carcinoma (HCC) is one of the most common malignancies globally, but its molecular mechanism is unclear. Abnormal expression of centromere protein U (CENPU) is closely related to diverse human cancers. The purpose of this article was to evaluate the function and potential mechanisms of CENPU in HCC development.

Methods

We performed bioinformatics analysis of The Cancer Genome Atlas (TCGA), Gene Expression Omnibus (GEO), Gene Expression Profiling Interactive Analysis (GEPIA), and Kaplan-Meier plotter databases to investigate the clinical significance and prognostic value of CENPU in HCC. Western blotting and immunohistochemical staining were used to measure protein expression, while reverse transcription-quantitative polymerase chain reaction (qRT-PCR) was used to determine mRNA expression. Cell Counting Kit8 (CCK-8) and colony formation assays were conducted to examine cell proliferation. Transwell and wound healing assays were used to assess cell migration and invasion. Gene set enrichment analysis (GSEA) was used to explore the potential signaling pathways of CENPU involved in HCC.

Results

High expression of CENPU in HCC was predicted by public database analysis and indicated a poor prognosis. CENPU expression was significantly higher in HCC tissues and cells than in normal tissues and cell. In vitro, CENPU promoted the proliferation, migration, and invasion of HCC cells. GSEA results indicated that CENPU was linked to the Notch signaling pathway, and our research supported this prediction.

Conclusion

CENPU promotes the malignant biological process of HCC and may be a promising target for HCC treatment.