Background: Colorectal cancer (CRC) is one of the leading causes of cancer-related death in China. Dysregulation of microRNAs (miRNAs) is involved in cancer development and progression. Our previous study showed an inverse relationship between miR-193a-3p expression and the prognosis of CRC. However, the exact biological functions of miR-193a-3p in CRC are still poorly understood. This study aimed to explore the role and mechanism of miR-193a-3p in CRC. Methods: Real-time PCR and Western blotting were used to examine the expression levels of RNA and protein, respectively. A dual luciferase assay was performed to validate predicted targets of miR-193a-3p. Loss and gain-of-function studies were carried out to reveal the effects and potential mechanism of the miR-193a-3p in the proliferation, metastasis and angiogenesis of CRC cells. Results: The expression levels of miR-193a-3p in human CRC cell lines were significantly decreased compared with that in normal colonic epithelium cell line. Furthermore, plasminogen activator urokinase (PLAU) was validated as a direct target gene of miR-193a-3p. Over-expression of miR-193a-3p inhibited proliferation, migration and angiogenesis of HT-29 cell, whereas forced expression of PLAU could rescue the inhibitory effects. Conclusion: miR-193a-3p might inhibit CRC cell growth, migration and angiogenesis partly through targeting PLAU. MiR-193a-3p/PLAU axis might provide a potent therapeutic opportunity for aggressive CRC.

Hepatocellular carcinoma (HCC) is characterized by frequent intrahepatic and distant metastases, resulting in a poor prognosis for patients. Epithelial–mesenchymal transition (EMT) plays a pivotal role in this process. However, the expression of NOP2/Sun RNA methyltransferase 5 (NSUN5) in HCC and its role in mediating EMT remain poorly understood. In this study, clinicopathological analyses are conducted across multiple independent HCC cohorts and induced tumor formation in Nsun5‐knockout mice. The findings reveal an upregulation of NSUN5 expression in tumor tissues; conversely, the absence of Nsun5 hinders the malignant progression of HCC, indicating that NSUN5 may serve as a significant oncogene in HCC. Furthermore, elevated levels of NSUN5 enhance EMT processes within HCC cells. NSUN5‐knockout cells exhibit reduced invasion and migration capabilities under both in vivo and in vitro conditions, while overexpression of NSUN5 yields opposing effects. Mechanistically, high levels of NSUN5 promote the enrichment of trimethylated histone H3 at lysine 4 (H3K4me3) at the promoter region of SMAD3 through recruitment of the WDR5, thereby facilitating HCC metastasis via SMAD3‐mediated EMT pathways. Collectively, this study identifies NSUN5 as a novel driver of metastasis in HCC and provides a theoretical foundation for potential therapeutic strategies against this malignancy.

Purpose: One of the most catastrophic malignant tumors is triple negative breast cancer (TNBC). It is characterized by rapid progression in the clinic. CircRNAs are abnormally expressed in almost all cancers and play important roles in tumor immune evasion. Nevertheless, the biological roles of the circular fibroblast growth factor receptor 4 RNA (circFGFR4) in TNBC remain unclear. Methods: The expression of circFGFR4 in TNBC tissues and paired nontumor tissues was detected using quantitative real-time polymerase chain reaction (qRT-PCR). The role of circFGFR4 in TNBC immune evasion was estimated by analyzing clinical tissues. In vivo circRNA precipitation, RNA immunoprecipitation, and luciferase reporter assays were performed to explore interaction between circFGFR4 and miR-185-5p. Results: Our results indicated that circFGFR4 was significantly overexpressed in TNBC tissues. Upregulated circFGFR4 expression was correlated with decreased CD8⁺ T cell infiltration in tumor tissues and resistance to anti-programmed cell death 1 (PD-1) immunotherapy in TNBC patients and mice bearing TNBC tumors. Forced circFGFR4 expression inhibited CD8⁺ T cell infiltration in tissue sections from TNCB tumor bearing mice. Mechanistically, circFGFR4 competitively sponged miR-185-5p and prevented miR-185-5p from decreasing the levels of C-X-C motif chemokine receptor 4 (CXCR4). Conclusion: Ultimately, our results indicated that circFGFR4 plays an important role in immune evasion and anti-PD-1 immunotherapy resistance via regulates miR-185-5p/CXCR4 axis in TNBC, thus suggesting that circFGFR4 has significant potential as a biomarker for predicting sensitivity to anti-PD-1 immunotherapy and as an immunotherapeutic target for TNBC.

Background: It is of great concern to identify prognostic signatures for the prediction and prediction of esophageal squamous cell carcinoma (ESCC), which is the lethal pathological type of malignancy. Method: Bulk RNA sequencing and scRNA-seq data were retrieved from GSE53624, GSE53622, and GSE188900. Disulfidptosis-related differentially expressed genes (DEGs) were identified between disulfidptosis-high score and disulfidptosis-low score groups. Functional annotation of DEGs were analyzed by Gene Ontology (GO). Consistent clustering and co-expression modules were analyzed, and then constructed a risk score model via multivariate Cox regression analysis. Immune infiltration and immunotherapy response analyses were conducted based on risk score. qRT-PCR, colony formation assay, and flow cytometry analysis were conducted in KYSE-150 and TE-1 cell lines. Results: Seven genes (CD96, CXCL13, IL2RG, LY96, TPK1, ACAP1, and SOX17) were selected as marker genes. CD96 and SOX17 are independent prognostic signatures for ESCC patients, with a significant correlation with infiltrated immune cells. ESCC patients had worse response to nivolumab in the high-risk group. Through cellular experiments, we found that CD96 expression was associated with apoptosis and cell cycle ESCC cells. Conclusion: In a word, the risk score based on disulfidptosis is associated with prognosis and the immune microenvironment, which may direct immunotherapy of ESCC. The key gene of risk score, namely CD96, plays a role in proliferation and apoptosis in ESCC. We offer an insight into the exploration of the genomic etiology of ESCC for its clinical management.