MicroRNAs (miRNAs), as key negative regulators of gene expression, are closely related to tumor occurrence and progression. miR-194-5p (miR-194-1) has been shown to play a regulatory role in various cancers however, its biological function and mechanism of action in breast cancer have not yet been well explored. In this study, we use the UALCAN and LinkedOmics databases to analyze transcription expression in The Cancer Genome Atlas Breast Invasive Carcinoma (TCGA-BRCA). The epithelial-mesenchymal transition status of breast cancer cells was evaluated by wound-healing assay, trans-well assays, and gelatin zymography, while protein expression was assessed by Western blotting. miR-194-5p expression was found to be up-regulated in breast cancer clinical specimens but down-regulated in the triple-negative breast cancer (TNBC) cell line MDA-MB-231 and breast cancer clinical specimens in The Cancer Genome Atlas (TCGA). miR-194-5p significantly inhibited the expression of the epithelial marker ZO-1 and increased the expression of mesenchymal markers, including ZEB-1 and vimentin, in MDA-MB-231 cells. miR-194-5p significantly reduced the gelatin-degrading activity of matrix metalloproteinase-2 (MMP-2) and MMP-9 in zymography assays. In MDA-MB-231 cells and TCGA patient samples, ZEB-1 expression was significantly inversely correlated with miR-194-5p expression. High levels of miR-194-5p were associated with good overall survival. miR-194-5p regulates epithelial–mesenchymal transition (EMT) in TNBC. Our findings suggest that miR-194-5p functions as a tumor biomarker in breast cancer, providing new insights for the study of breast cancer development and metastasis.

Although oncolytic viruses are currently being evaluated for cancer treatment in clinical trials, systemic administration is hindered by many factors that prevent them from reaching the tumor cells. When administered systemically, mesenchymal stem cells (MSCs) target tumors, and therefore constitute good cell carriers for oncolytic viruses. MSCs were primed with trichostatin A under hypoxia, which upregulated the expression of CXCR4, a chemokine receptor involved in tumor tropism, and coxsackievirus and adenovirus receptor that plays an important role in adenoviral infection. After priming, MSCs were loaded with conditionally replicative adenovirus that exhibits limited proliferation in cells with a functional p53 pathway and encodes Escherichia coli nitroreductase (NTR) enzymes (CRAdNTR) for targeting tumor cells. Primed MSCs increased tumor tropism and susceptibility to adenoviral infection, and successfully protected CRAdNTR from neutralization by anti-adenovirus antibodies both in vitro and in vivo, and specifically targeted p53-deficient colorectal tumors when infused intravenously. Analyses of deproteinized tissues by UPLC-MS/QTOF revealed that these MSCs converted the co-administered prodrug CB1954 into cytotoxic metabolites, such as 4-hydroxylamine and 2-amine, inducing oncolysis and tumor growth inhibition without being toxic for the host vital organs. This study shows that the combination of oncolytic viruses delivered by MSCs with the activation of prodrugs is a new cancer treatment strategy that provides a new approach for the development of oncolytic viral therapy for various cancers.

Hepatocellular carcinoma (HCC) exhibits profound glycolytic reprogramming that drives tumor growth, impairs apoptosis, and suppresses immune responses, leading to resistance against conventional therapies. To overcome this challenge, we developed a stimuli-responsive nanozyme composed of a pH-sensitive lipid-gelatin-protamine (LGP) nanogel encapsulating glucose oxidase (GOx). This tumor-selective nanozyme depletes intratumoral glucose under acidic conditions, inducing oxidative and endoplasmic reticulum stress, upregulating death receptors, and sensitizing HCC cells to TRAIL- and doxorubicin (DOX)-induced apoptosis. Co-delivery of GOx and DOX within the nanozyme reprograms tumor immunometabolism, enhancing immunogenic cell death and promoting the release of damage-associated molecular patterns (DAMPs). These changes stimulate dendritic cell maturation and cytotoxic CD8⁺ T-cell activation. Transcriptomic profiling confirms that this nanozyme remodels the immunosuppressive microenvironment by suppressing metabolic pathways while activating immune-related gene programs. When combined with an anti-PD-1 checkpoint blockade, the nanozyme elicits potent tumor regression and abrogates metastasis without systemic toxicity in orthotopic HCC models. Overall, this work introduces a multifunctional tumor-responsive nanozyme that integrates metabolic intervention, apoptotic priming, and immune activation to overcome therapeutic resistance in the HCC.

Colorectal cancer (CRC) remains a major cause of cancer-related mortality worldwide. While immune checkpoint blockade (ICB) has transformed cancer therapy, its clinical benefit in CRC is often limited by an immune-excluded tumor microenvironment (TME). MicroRNA-21-5p (miR-21-5p) is a well-established oncomiR in CRC; however, its role in immune resistance remains incompletely elucidated. In this study, we explored the potential immunoregulatory role of miR-21-5p in CRC by integrating transcriptomic profiling of TCGA-COAD and TCGA-READ cohorts with experimental validation of its target PTEN in CRC cell models. MiR-21-5p was markedly upregulated in tumors compared with adjacent normal tissues and was associated with reduced infiltration of CD8⁺ T cells and dendritic cells. Functional assays confirmed that miR-21-5p directly targets PTEN; transcriptomic correlations further suggested potential links to PI3K/AKT activation and alterations in JAK–STAT and Th17-associated signaling. Elevated miR-21-5p was associated with transcriptomic signatures indicative of altered Th1/Th2 balance, reduced IgA-related immune responses, and features of an immune-excluded TME. Therapeutically, the inhibition of miR-21-5p has been reported in previous studies to restore PTEN and modulate signaling pathways. However, our study did not evaluate immune reactivation or checkpoint-blockade efficacy; thus, such therapeutic implications remain hypothetical. Collectively, these findings suggest that the miR-21–PTEN–PI3K/AKT axis may contribute to shaping immune-related features in CRC. These findings provide a rationale for future studies investigating whether targeting miR-21-5p could enhance antitumor immunity or improve immunotherapy response in CRC.

In most cancers, cellular origin and the contribution of intrinsic and extrinsic factors toward transformation remain elusive. Cell specific carcinogenesis models are currently unavailable. To investigate cellular origin in carcinogenesis, we developed a tumorigenesis model based on a combination of carcinogenesis and genetically engineered mouse models. We show in organoids that treatment of any of three carcinogens, DMBA, MNU, or PhIP, with protein phosphatase 2A (PP2A) knockout induced tumorigenesis in Lgr5⁺ intestinal lineage, but not in differentiated cells. These transformed cells increased in stem cell signature, were upregulated in EMT markers, and acquired tumorigenecity. A mechanistic approach demonstrated that tumorigenesis was dependent on Wnt, PI3K, and RAS-MAPK activation. In vivo combination with carcinogen and PP2A depletion also led to tumor formation. Using whole-exome sequencing, we demonstrate that these intestinal tumors display mutation landscape and core driver pathways resembling human intestinal tumor in The Cancer Genome Atlas (TCGA). These data provide a basis for understanding the interplay between extrinsic carcinogen and intrinsic genetic modification and suggest that PP2A functions as a tumor suppressor in intestine carcinogenesis.