Systematic analysis identifies XRCC4 as a potential immunological and prognostic biomarker associated with pan-cancer

Crosstalk between BER and NHEJ in XRCC4-Deficient Cells Depending on hTERT Overexpression

Targeting DNA repair pathways is an important strategy in anticancer therapy. However, the unrevealed interactions between different DNA repair systems may interfere with the desired therapeutic effect. Among DNA repair systems, BER and NHEJ protect genome integrity through the entire cell cycle. BER is involved in the repair of DNA base lesions and DNA single-strand breaks (SSBs), while NHEJ is responsible for the repair of DNA double-strand breaks (DSBs). Previously, we showed that BER deficiency leads to downregulation of NHEJ gene expression. Here, we studied BER's response to NHEJ deficiency induced by knockdown of NHEJ scaffold protein XRCC4 and compared the knockdown effects in normal (TIG-1) and hTERT-modified cells (NBE1). We investigated the expression of the XRCC1, LIG3, and APE1 genes of BER and LIG4; the Ku70/Ku80 genes of NHEJ at the mRNA and protein levels; as well as p53, Sp1 and PARP1. We found that, in both cell lines, XRCC4 knockdown leads to a decrease in the mRNA levels of both BER and NHEJ genes, though the effect on protein level is not uniform. XRCC4 knockdown caused an increase in p53 and Sp1 proteins, but caused G1/S delay only in normal cells. Despite the increased p53 protein, p21 did not significantly increase in NBE1 cells with overexpressed hTERT, and this correlated with the absence of G1/S delay in these cells. The data highlight the regulatory function of the XRCC4 scaffold protein and imply its connection to a transcriptional regulatory network or mRNA metabolism.

Decoding the neurotoxic effects of propofol: insights into the RARα-Snhg1-Bdnf regulatory cascade

The potential neurotoxic effects of propofol, an extensively utilized anesthetic, underline the urgency to comprehend its influence on neuronal health. Insights into the role of the retinoic acid receptor-α, small nucleolar RNA host gene 1, and brain-derived neurotrophic factor (RARα-Snhg1-Bdnf) network can offer significant advancements in minimizing these effects. The study targets the exploration of the RARα and Snhg1 regulatory network's influence on Bdnf expression in the realm of propofol-induced neurotoxicity. Harnessing the Gene Expression Omnibus (GEO) database and utilizing JASPAR and RNA-Protein Interaction Prediction (RPISeq) database for projections, the study embarks on an in-depth analysis employing both in vitro and in vivo models. The findings draw a clear link between propofol-induced neurotoxicity and the amplification of RAR signaling pathways, impacting hippocampal development and apoptosis and leading to increased RARα and Snhg1 and decreased Bdnf. Propofol is inferred to accentuate neurotoxicity by heightening RARα and Snhg1 interactions, culminating in Bdnf suppression.NEW & NOTEWORTHY This study aimed to decode propofol's neurotoxic effects on the regulatory cascade, provide insights into the RARα-Snhg1-Bdnf interaction, apply extensive validation techniques, provide a detailed analysis and exploration of propofol's neurotoxicity, and offer a comprehensive approach to understanding molecular interactions.

In silico analyses of pan-squamous cell carcinoma unveiled the immunological implications of MRPL13, which had previously been under-recognized

The involvement of the mitochondrial ribosomal protein 13 (MRPL13) gene in the development of adenocarcinoma has been previously reported. However, the clinicopathological significance of MRPL13 in squamous cell carcinoma (SCC) remains poorly understood. To gain insight into the clinicopathological and immunological implications of MRPL13 expression in SCC, we conducted a bioinformatic analysis utilizing various available databases, including TIMER 2.0, Xiantao academic tool and TISIDB, attempting to evaluate the abnormal expression, prognosis and immunological correlation of MRPL13 in the pan-SCC setting. Subsequently, we conducted experimental verification using an esophageal squamous cell carcinoma (ESCC) tissue array subjected to multiplexed immunofluorescent (mIF) staining. The ESCC tissue array we used consists of 93 dots of ESCC and 86 dots of matched adjacent normal tissues (ANT). Data from in silico analyses showed that MRPL13 mRNA is significantly up-regulated and correlated with infiltration of CD8+ T cells in pan-SCC. However, in silico analyses did not support the prognostic role of MRPL13 in SCC. Consistently, data from the ESCC tissue array showed that MRPL13 was remarkably elevated in ESCC tissues relative to ANT in stroma, which was controlled by pan-cytokeratin (pan-CK) staining. In the epithelia, no significant difference was identified between ESCC and ANT. Furthermore, MRPL13 expression markedly correlated with the infiltration of CD8+ T cells in the stromal region but not in the epithelial region. Prognostically, no significant association was observed between MRPL13 expression and overall survival, regardless of epithelial or stromal section. Through these pan-SCC analyses, we have expanded the understanding of MRPL13 previously reported, in particular, underscoring the immunological involvement of MRPL13 in the tumor microenvironment of SCC that has been under-recognized before, suggesting that MRPL13 may regulate the infiltration of CD8+ T cells into the SCC microenvironment.

Comprehensive analysis of ZNF692 as a potential biomarker associated with immune infiltration in a pan cancer analysis and validation in hepatocellular carcinoma

Currently, the roles of ZNF692 have been documented exclusively in lung, colon, and cervical cancers. However, its involvement in pan cancer remains unknown. In this study, we employed bioinformatics analysis and experimental validation to investigate the role of ZNF692 in pan cancer. Our findings revealed aberrant expression of ZNF692 across various types of cancer. High expression of ZNF692 was associated with poor overall survival (OS) in ACC, COAD, KIRC, LAML, and LIHC. ZNF692 exhibited promising diagnostic potential in certain tumor types. A significant correlation was observed between high ZNF692 expression and advanced stages of ACC, BLCA, KICH, KIRC, LIHC, and OV. The expression of ZNF692 exhibited a significant association with microsatellite instability (MSI) in eight types of cancer and tumor mutational burden (TMB) in ten types of cancer. A noteworthy correlation was observed between ZNF692 expression and immune infiltration as well as immune checkpoints. Amplification of ZNF692 emerged as the most frequent alteration in pan cancer. ZNF692 was implicated in various biological processes, cellular components, and molecular functions within the context of pan cancer. It is plausible that ZNF692 may contribute to chemotherapy and potentially be linked to chemoresistance. We constructed a competing endogenous RNA (ceRNA) network involving AC009403.11/miR-126-3p/ZNF692 in hepatocellular carcinoma (HCC). The expression of ZNF692 exhibited a notable upregulation in HCC cell lines. Aberrant expression of ZNF692 was observed across various types of cancer. ZNF692 holds potential as a valuable diagnostic, prognostic, and therapeutic target in the context of pan cancer.

Integrated single-cell and bulk sequencing analyses with experimental validation identify the prognostic and immunological implications of CD226 in pan-cancer

PURPOSE

CD226 (DNAM-1) is an activating receptor mainly expressed in CD8 + and NK cells. CD226 deficiency and blockade have been shown to impair tumor suppression, while enhanced CD226 expression positively correlated with the increased efficacy of immune checkpoint blockade (ICB) therapies. However, the detailed function and role of CD226 in pan-cancer are largely unknown and require further in-depth investigation. Therefore, this study aims to investigate the biological functions of CD226, its role in tumor immunity, and its potential to predict prognosis and immunotherapy response in pan-cancer.

METHODS

By taking advantage of single-cell and bulk sequencing analyses, we analyzed the expression profile of CD226, its correlation with patient prognosis, immune infiltration level, immune-related genes, tumor heterogeneity, and stemness in pan-cancer. We also investigated the biological functions of CD226 using gene set enrichment analysis (GSEA) and evaluated its predictive value in response to immunotherapy and small-molecule targeted drugs. In addition, we validated the expression of CD226 in tumor-infiltrating CD8 + and NK cells and studied its association with their functions using a murine B16F10 melanoma model.

RESULTS

CD226 exhibited differential expression across most tumor types, and its elevated expression was associated with improved clinical outcomes in multiple cancer types. CD226 is closely correlated with numerous tumor-infiltrating immune cells, tumor stemness, and heterogeneity in most cancers. Furthermore, based on single-cell sequencing analysis, CD226 expression was found to be higher on effector CD4 + T cells than naïve CD4 + T cells, and its expression level was decreased in exhausted CD8 + T cells relative to effector CD8 + T cells in multiple cancer types. Additionally, flow cytometric analysis demonstrated that CD226 was highly correlated with the function of tumor-infiltrating NK and CD8 + T cells in murine B16F10 melanoma. Moreover, GSEA analysis revealed that CD226 was closely associated with T cell activation, natural killer cell mediated immunity, natural killer cell-mediated cytotoxicity, and T cell receptor signaling pathway. Finally, CD226 showed promising predictive potential for responsiveness to both ICB therapies and various small-molecule targeted drugs.

CONCLUSION

CD226 has shown great potential as an innovative biomarker for predicting patient prognosis, immune infiltration levels, and the function of tumor-infiltrating CD8 + T cells, as well as immunotherapy response. Additionally, our findings suggest that the optimal modification of CD226 expression and function, combined with current ICBs, could be a promising strategy for tumor immunotherapy.

PHF5A is a potential diagnostic, prognostic, and immunological biomarker in pan-cancer

Studying the molecular mechanisms and regulatory functions of genes is crucial for exploring new approaches and tactics in cancer therapy. Studies have shown that the aberrant expression of PHF5A in tumors is linked to the origin and advancement of multiple cancers. However, its role in diagnosis, prognosis, and immunological prediction has not been comprehensively investigated in a pan-cancer analysis. Using several bioinformatic tools, we conducted a systematic examination of the potential carcinogenesis of PHF5A in various tumors from multiple aspects. Our analysis indicated that PHF5A expression varied between normal and tumor tissues and was linked to clinical diagnosis and prognosis in various cancers. The results confirmed a notable variation in the levels of PHF5A promoter methylation among several types of primary tumor and normal tissues and methylation of the PHF5A promoter played a guiding role in prognosis in some cancers. According to our findings, PHF5A played a critical role in tumor immunity and it might be an excellent target for anticancer immunotherapy. To sum up, PHF5A can be used in pan-cancer diagnostics, prognostics, and immunotherapy.

N-glycosylation by N-acetylglucosaminyltransferase IVa enhances the interaction of integrin β1 with vimentin and promotes hepatocellular carcinoma cell motility

N-glycosylation has been revealed to be tightly associated with cancer metastasis. As a key transferase that catalyzes the formation of β1,4 N-acetylglucosamine (β1,4GlcNAc) branches on the mannose core of N-glycans, N-acetylglucosaminyltransferase IVa (GnT-IVa) has been reported to be involved in hepatocellular carcinoma (HCC) metastasis by forming N-glycans; however, the underlying mechanisms are largely unknown. In the current study, we found that GnT-IVa was upregulated in HCC tissues and positively correlated with worse outcomes in HCC patients. We found that GnT-IVa could promote tumor growth in mice; notably, this effect was attenuated after mutating the enzymatic site (D445A) of GnT-IVa, suggesting that GnT-IVa regulated HCC progression by forming β1,4GlcNAc branches. To mechanistically investigate the role of GnT-IVa in HCC, we conducted GSEA and GO functional analysis as well as in vitro experiments. The results showed that GnT-IVa could enhance HCC cell migration, invasion and adhesion ability and increase β1,4GlcNAc branch glycans on integrin β1 (ITGB1), a tumor-associated glycoprotein that is closely involved in cell motility by interacting with vimentin. Interruption of β1,4GlcNAc branch glycan modification on ITGB1 could suppress the interaction of ITGB1 with vimentin and inhibit cell motility. These results revealed that GnT-IVa could promote HCC cell motility by affecting the biological functions of ITGB1 through N-glycosylation. In summary, our results revealed that GnT-IVa is highly expressed in HCC and can form β1,4GlcNAc branches on ITGB1, which are essential for interactions with vimentin to promote HCC cell motility. These findings not only proposed a novel mechanism for GnT-IVa in HCC progression but also revealed the significance of N-glycosylation on ITGB1 during the process, which may provide a novel target for future HCC therapy.