Comprehensive analysis of PHF5A as a potential prognostic biomarker and therapeutic target across cancers and in hepatocellular carcinoma.

OBJECTIVE: Cancer is a predominant cause of death globally. PHD-finger domain protein 5 A (PHF5A) has been reported to participate in various cancers; however, there has been no pan-cancer analysis of PHF5A. This study aims to present a novel prognostic biomarker and therapeutic target for cancer treatment. METHODS: This study explored PHF5A expression and its impact on prognosis, tumor mutation burden (TMB), microsatellite instability (MSI), functional status and tumor immunity across cancers using various public databases, and validated PHF5A expression and its correlation with survival, immune evasion, angiogenesis, and treatment response in hepatocellular carcinoma (HCC) using bioinformatics tools, qRT-PCR and immunohistochemistry (IHC). RESULTS: PHF5A was differentially expressed between tumor and corresponding normal tissues and was correlated with prognosis in diverse cancers. Its expression was also associated with TMB, MSI, functional status, tumor microenvironment, immune infiltration, immune checkpoint genes and tumor immune dysfunction and exclusion (TIDE) score in diverse malignancies. In HCC, PHF5A was confirmed to be upregulated by qRT-PCR and IHC, and elevated PHF5A expression may promote immune evasion and angiogenesis in HCC. Additionally, multiple canonical pathways were revealed to be involved in the biological activity of PHF5A in HCC. Moreover, immunotherapy and transcatheter arterial chemoembolization (TACE) worked better in the low PHF5A expression group, while sorafenib, chemotherapy and AKT inhibitor were more effective in the high expression group. CONCLUSIONS: This study provides a comprehensive understanding of the biological function of PHF5A in the carcinogenesis and progression of various cancers. PHF5A could serve as a tumor biomarker related to prognosis across cancers, especially HCC, and shed new light on the development of novel therapeutic targets.

Intestinal Epithelial Cell-specific Knockout of METTL3 Aggravates Intestinal Inflammation in CLP Mice by Weakening the Intestinal Barrier.

BACKGROUND: Many studies have demonstrated that the expression of methyltransferase- like 3 (METTL3) is altered in various inflammatory diseases. Its specific mechanistic role in the intestinal inflammatory response during sepsis remains limited and requires further investigation. OBJECTIVES: Explore the potential mechanism of METTL3 in the intestinal inflammatory response during sepsis. MATERIALS AND METHODS: Immunohistochemical analysis was utilized to detect the expression of METTL3 in the necrotic intestine of patients with intestinal necrosis and the small intestine of cecal ligation and puncture (CLP) mice. Mice were subjected to the CLP and Sham surgeries, intestine tissue was harvested and performed HE staining, and ELISA to examine intestinal inflammatory responses, while TUNEL staining was applied to detect intestinal cell apoptosis. Additionally, ELISA was used to detect diamine oxidase (DAO) and intestinal fatty acid binding protein (I-FABP) levels in intestinal tissue. Immunohistochemistry and RT-qPCR were also employed to examine the mRNA and protein expression levels of Zona Occludens 1 (ZO-1) and Claudin-1. Finally, transcriptomic sequencing was performed on the small intestine tissues of METTL3 Knock-out (KO) and Wild-type (WT) mice in response to sepsis. RESULTS: METTL3 exhibited lower expression level in the necrotic intestine of patients and the small intestine of CLP mice. Loss of METTL3 in CLP mice triggered significantly higher expression of TNF-α and IL-18, down-regulated expression of ZO-1 and claudin-1, and decreased expression of DAO and I-FABP in the intestinal tissue. KEGG enrichment analysis showed that the differential genes were significantly enriched in immune-related pathways. CONCLUSION: This study reveals a novel mechanism responsible for exacerbated intestinal inflammation orchestrated by METTL3. Particularly, METTL3 null mice displayed decreased ZO- 1 and Claudin-1 expression, which largely hampered intestinal epithelial barrier function, resulting in bacterial and toxin translocation and intestinal immune activation and inflammation against sepsis.