BackgroundThis study aimed to explore the regulatory mechanism of hsa-miR-143-3p and lncRNA RP11-363N22.3–functioning upstream of KRAS–in exosomes derived from human mesenchymal stem cells (hMSCs) in pancreatic cancer.MethodsWestern blotting and quantitative PCR were used to determine gene expression. In vitro, cell proliferation, apoptosis, and cell cycle and invasion were evaluated using CCK-8 assay, flow cytometry, and transwell assays, respectively. In vivo, the effect of hsa-miR143-3p was investigated using a tumorigenesis test in nude mice. The association between hsa-miR-143-3p and lncRNA RP11-363N22.3 was investigated using the dual-luciferase assay.Resultshsa-miR-143-3p expression significantly increased in hMSC exosomes than in those in human pancreatic cancer cell line (CFPAC-1) exosomes. In vitro, compared to the MOCK (CFPAC-1 only) group, cell proliferation and invasion were inhibited and apoptosis was induced in the inhibitor NC (CFPAC-1 + MSC-hsa-miR-3p inhibitor NC) group, while these changes were reversed in the inhibitor (CFPAC-1 + MSC-hsa-miR-3p inhibitor) group. The expression of lncRNA RP11-363N22.3 and genes related to miR-143 significantly decreased in the inhibitor NC group compared to the MOCK group, and increased in the inhibitor group compared to inhibitor NC group. A targeted combinatorial effect was observed between lncRNA RP11-363N22.3 and hsa-miR-143-3p. In vivo, the tumor volume of the mimics (CFPAC-1 + MSC-hsa-miR-143-3p mimics) group was smaller than that of the mimics NC (CFPAC-1 + MSC-hsa-miR-143-3p mimics NC) and MOCK groups. H&E staining showed that there were no obvious pathological changes in MOCK and mimic NC groups, while cell necrosis was seen in some regions in mimic groups.Conclusionhsa-miR-143-3p may promote apoptosis and suppress cell growth and invasion in pancreatic cancer.

Background CD8+ tumor-infiltrating T lymphocytes (T-TILs) in the tumor microenvironment (TME) play an important role in tumor development, and miRNAs regulate tumor cell interactions with the microenvironment. T-TIL-based tumor immunotherapy provides a promising treatment strategy in diffuse large B-cell lymphoma (DLBCL). MiRNAs tend to be attractive targets for novel antitumor interventions. Methods Weighted gene coexpression network analysis (WGCNA), CIBERSORT analysis and Cox regression analysis were used to identify CD8+ T-TIL-related miRNAs. RT-PCR, western blotting, immunohistochemistry (IHC), in situ hybridization (ISH), luciferase reporter assay, coimmunoprecipitation and ubiquitination analyses were used to detect miRNA, mRNA and protein expression and their combination. The viability and function of CD8+ T cells after stimulation were evaluated by enzyme-linked immunosorbent assay (ELISA), cytotoxicity assay, functional avidity assessment, flow cytometry and Cell Counting Kit-8 (CCK-8) assay. DLBCL cell lines, primary cells and a murine xenograft model established with A20 cell injection were used as in vitro and in vivo experimental models. Results MiR-340-5p was positively correlated with CD8+ T-TILs in DLBCL patients, and KMT5A was a direct target gene of miR-340-5p. CD8+ T-cell function was significantly enhanced by miR-340-5p mimics both in vitro and in vivo, which was reversed by KMT5A overexpression. We demonstrated that COP1/CD73 was involved in the downstream mechanism of the miR-340-5p/KMT5A axis involving ubiquitination. In vivo, we validated an improved CD8+ T-TIL infiltration rate and tumor suppression with miR-340-5p treatment. Furthermore, miR-340-5p directly regulated the biological activity of DLBCL cells without CD8+ T-cell participation. Conclusions MiR-340-5p promoted CD8+ T-TIL infiltration and antitumor function by regulating KMT5A and COP1 and further activating CD73 ubiquitination. MiR-340-5p is potentially a novel target for DLBCL immunotherapy.