Upregulation of Excision Repair Cross-Complementation Group 6-Like (ERCC6L) Promotes Tumor Growth in Hepatocellular Carcinoma

Cinobufacini Inhibits Survival and Metastasis of Hepatocellular Carcinoma via c-Met Signaling Pathway

OBJECTIVE

To investigate the anti-tumor effects of cinobufacini (CINO) on hepatocellular carcinoma (HCC) induced by des-gamma-carboxy-prothrombin (DCP) and to uncover the underlying mechanisms.

METHODS

The inhibitory effect of CINO on HCC cell proliferation was evaluated using the cell counting kit-8 method, and the apoptosis rate was quantified using flow cytometry. Immunofluorescence and Western blot analyses were used to investigate the differential expression of proteins associated with cell growth, apoptosis, migration, and invasion pathways after CINO treatment. The therapeutic potential of CINO for HCC was confirmed, and the possibility of combining cinobufacini with c-Met inhibitor for the treatment of primary HCC was further validated by in vivo experiments.

RESULTS

Under the induction of DCP, CINO inhibited the activity of HCC cells, induced apoptosis, and inhibited migration and invasion. Upon the induction of DCP, CINO regulated c-Met activation and the activation of the phosphatidylinositol-3 kinase/protein kinase B (PI3K/AKT) and mitogen-activated protein kinase kinase/extracellular signal-regulated kinase (MEK/ERK) pathways. In a mouse model of HCC, CINO exhibited significant antitumor effects by inhibiting the phosphorylation of c-Met and the downstream PI3K/AKT and MEK/ERK pathways in tumor tissues.

CONCLUSIONS

CINO inhibited HCC cell growth, promoted apoptosis, and suppressed HCC cell invasion and migration by targeting c-Met and PI3K/AKT and MEK/ERK signaling pathways under DCP induction.

PICH, A protein that maintains genomic stability, can promote tumor growth

Genomic instability is regardedas a hallmark of cancer cells. It can be presented in many ways, among which chromosome instability has received attention. Ultrafine anaphase bridges are a typeof chromatin bridges, the untimely resolution of which can also lead to chromosome instability. PICH can play a role in maintaining chromosome stability by regulating chromosome morphologyand resolving ultrafine anaphase bridges. Recently, PICH has been found to be overexpressed in various cancers. Overexpression of PICH is related to the proliferation of tumors and poor prognosis. In this article, we consider that PICH can maintain genomic stability by regulating appropriate chromosome structure, ensuring proper chromosome segregation, and facilitating replication fork reversal. We summarize how PICH regulates chromosome stability, how PICH resolves Ultrafine anaphase bridges with other proteins, and how PICH promotes tumor progression.

PICH deficiency limits the progression of MYC-induced B-cell lymphoma

Plk1-interacting checkpoint helicase (PICH) is a DNA translocase involved in resolving ultrafine anaphase DNA bridges and, therefore, is important to safeguard chromosome segregation and stability. PICH is overexpressed in various human cancers, particularly in lymphomas such as Burkitt lymphoma, which is caused by MYC translocations. To investigate the relevance of PICH in cancer development and progression, we have combined novel PICH-deficient mouse models with the Eμ-Myc transgenic mouse model, which recapitulates B-cell lymphoma development. We have observed that PICH deficiency delays the onset of MYC-induced lymphomas in Pich heterozygous females. Moreover, using a Pich conditional knockout mouse model, we have found that Pich deletion in adult mice improves the survival of Eμ-Myc transgenic mice. Notably, we show that Pich deletion in healthy adult mice is well tolerated, supporting PICH as a suitable target for anticancer therapies. Finally, we have corroborated these findings in two human Burkitt lymphoma cell lines and we have found that the death of cancer cells was accompanied by chromosomal instability. Based on these findings, we propose PICH as a potential therapeutic target for Burkitt lymphoma and for other cancers where PICH is overexpressed.

ERCC6L facilitates the progression of laryngeal squamous cell carcinoma by the binding of FOXM1 and KIF4A

The role of excision repair cross-complementation group 6-like (ERCC6L) has been reported in several cancers, but little is known about its expression and function in laryngeal squamous cell carcinoma (LSCC). In this study, the expression of ERCC6L in LSCC was determined by immunohistochemistry and its correlation with prognostic factors was analyzed. Furthermore, cytological functional validation elucidated the role and underlying mechanisms of ERCC6L dysregulation in LSCC. Our data revealed that ERCC6L expression was elevated in LSCC and it's correlated with TNM stage. In addition, ERCC6L knockdown LSCC cells showed decreased proliferation and migration, increased apoptosis, and reactive oxygen species (ROS). Mechanically, overexpression of ERCC6L promoted nuclear translocation of FOXM1 to facilitate direct binding to the KIF4A promoter and upregulated KIF4A expression. Furthermore, KIF4A knockdown attenuated the role of ERCC6L overexpression in promoting proliferation, migration, and tumorigenesis of LSCC cells. In summary, ERCC6L promoted the binding of FOXM1 and KIF4A in LSCC cells to drive their progression, which may be a promising target for precision therapy in this disease.

A pan-cancer analysis of the oncogenic role of ERCC6L

BACKGROUND

Excision repair cross-complementation group 6 like (ERCC6L), a polo-like kinase 1 (PLK1)-interacting checkpoint helicase, confers a high risk of cancer and enhances the progression of a variety of cancers. The present investigation aimed to elucidate the pan-cancer expression patterns of ERCC6L and to examine the possibility of using this gene for patient diagnosis and prognosis.

METHODS

The expression patterns of ERCC6L in normal and cancer patients at various clinical stages were explored based on TCGA datasets. Subsequently, Bioinformatics techniques were then used to analyze patient's survival probabilities, Cox multivariate clinical parameters, Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) terms related to ERCC6L, the correlation between mRNA expression levels and patient survival, genetic alterations or somatic mutations of ERCC6L, and immune infiltration.

RESULTS

Most cancer types had higher ERCC6L mRNA levels than normal tissue. Higher ERCC6L expression levels were correlated with poor prognosis for cancer patients. Thus, ERCC6L may serve as an effective diagnostic and prognostic marker for multiple cancers. Moreover, ERCC6L expression levels were higher in patients with higher clinical tumor grades and were associated with poor prognoses at these stages. GO and KEGG analyses revealed a correlation between ERCC6L expression levels and chromatin and cell cycle events. We also found that the mRNA expression level of the ERCC6L promoter and a favorable prognosis was negatively correlated with the promoter's methylation but not with copy number variation. A quantitative analysis of immune infiltration suggested a positive correlation between ERCC6L levels and the infiltration of Th2 immune cells in main cancer types. Finally, we examined the ERCC6L somatic mutations, especially single-nucleotide variants, and ERCC6L expression-related drug sensitivity.

CONCLUSIONS

Herein, we reported a comprehensive investigation of the tumor-promoting role of ERCC6L in various cancer types. ERCC6L is a candidate biomarker for diagnosing and unfavorable prognosis of specific cancers.

Overexpression of ERCC6L correlates with poor prognosis and confers malignant phenotypes of lung adenocarcinoma

Excision repair cross‑complementation group 6 like (ERCC6L) has been reported to be upregulated in a variety of malignant tumors and plays a critical oncogenic role. However, the role and molecular mechanism of ERCC6L in lung adenocarcinoma (LUAD) remain unclear, and were therefore investigated in the present study. Clinical data of patients with LUAD were obtained and bioinformatics analysis was performed to investigate the expression characteristics, prognostic value, and biological function of ERCC6L. In addition, cell function experiments were performed to detect the effect of ERCC6L silencing on the biological behavior of LUAD cells. The results revealed that ERCC6L expression was significantly higher in LUAD tissues vs. normal lung tissues and closely associated with nodal invasion, advanced clinical stage and survival in LUAD. Overexpression of ERCC6L was an independent prognostic biomarker of overall survival, progression‑free interval, and disease‑specific survival in patients with LUAD. DNA amplification and low methylation levels of ERCC6L suggested regulation at both the genetic and epigenetic levels. The most significant positive genes co‑expressed with ERCC6L were mainly enriched in the cell cycle signaling pathway. The major functions of ERCC6L in LUAD cells were positively correlated with the cell cycle, DNA damage, DNA repair, proliferation, invasion and epithelial‑mesenchymal transition (EMT). Knockdown of ERCC6L inhibited the proliferative, migratory and invasive abilities of A549 and PC9 cells. It also promoted cell apoptosis, and led to cell cycle arrest in the S phase. ERCC6L may regulate the EMT process through the Wnt/β‑catenin and Wnt/Notch 3 signaling pathways, thus regulating the tumorigenesis and progression of LUAD. The overexpression of ERCC6L may be a biological indicator for the diagnosis and prognosis of LUAD. ERCC6L may be a novel molecular target for the treatment of lung cancer.

Regulation of mitotic chromosome architecture and resolution of ultrafine anaphase bridges by PICH

To ensure genome stability, chromosomes need to undergo proper condensation into two linked sister chromatids from prophase to prometaphase, followed by equal segregation at anaphase. Emerging evidence has shown that persistent DNA entanglements connecting the sister chromatids lead to the formation of ultrafine anaphase bridges (UFBs). If UFBs are not resolved soon after anaphase, they can induce chromosome missegregation. PICH (PLK1-interacting checkpoint helicase) is a DNA translocase that localizes on chromosome arms, centromeres and UFBs. It plays multiple essential roles in mitotic chromosome organization and segregation. PICH also recruits other associated proteins to UFBs, and together they mediate UFB resolution. Here, the proposed mechanism behind PICH's functions in chromosome organization and UFB resolution will be discussed. We summarize the regulation of PICH action at chromosome arms and centromeres, how PICH recognizes UFBs and recruits other UFB-associated factors, and finally how PICH promotes UFB resolution together with other DNA processing enzymes.

Upregulation of ERCC6L is associated with tumor progression and unfavorable prognosis in hepatocellular carcinoma

Background

The oncogenic role of excision repair cross-complementation group 6-like (ERCC6L) has been revealed in several cancers recently, but little is known about its expression and function in hepatocellular carcinoma (HCC).

Methods

Utilizing public data from Human Protein Atlas (HPA) and The Cancer Genome Atlas (TCGA) databases, ERCC6L dysregulation in HCC and its clinical significance were determined by t-test and Chi-square test. Comprehensive survival analyses (such as nomogram, Cox regression model and Kaplan-Meier analysis) were performed to assess prognostic value of ERCC6L for HCC patients. Integrated bioinformatics analyses [including copy number alterations (CNA), DNA methylation, miRNA prediction and gene set enrichment analysis (GSEA)] were conducted to explore the mechanisms and biological roles underlying ERCC6L dysregulation in HCC.

Results

ERCC6L upregulation was identified in HCC tissues compared to normal controls (P<0.05). In addition, overexpression of ERCC6L not only correlated with elevated alpha fetoprotein (AFP), vascular invasion (VI), and advanced histologic grade and TNM stage, but also had an independent prognostic value for the poorer overall survival (OS) and recurrence-free survival (RFS) of HCC patients (all P<0.05). Besides, nomogram integrating ERCC6L expression and TNM stage showed superior prognostic ability than that of TNM stage (P<0.05). Moreover, ERCC6L promoter hypomethylation and miR-5589 downregulation in HCC might result in ERCC6L overexpression (all P<0.05). Furthermore, eight biological pathways (including the DNA replication, cell cycle and p53 pathways) related to ERCC6L upregulation in HCC were found to be enriched by GSEA, and ERCC6L upregulation was positively correlated with PLK1 (polo-like kinase 1) expression and TP53 mutation in HCC, which preliminarily shed light on the roles of ERCC6L in HCC.

Conclusions

ERCC6L may serve as a promising prognostic indicator and therapeutic target for HCC patients.