Combining bioinformatics techniques to explore the molecular mechanisms involved in pancreatic cancer metastasis and prognosis.

This article aims to explore the underlying molecular mechanisms and prognosis-related genes in pancreatic cancer metastasis. Pancreatic cancer metastasis-related gene chip data were downloaded from GENE EXPRESSION OMNIBUS(GEO)database. Differentially expressed genes were screened after R-package pre-treatment. Functional annotations and related signalling pathways were analysed using DAVID software. GEPIA (Gene Expression Profiling Interactive Analysis) was used to perform prognostic analysis, and differential genes associated with prognosis were screened and validated using data from GEO. We screened 40 healthy patients, 40 primary pancreatic cancer and 40 metastatic pancreatic cancer patients, collected serum, designed primers and used qPCR to test the expression of prognosis-related genes in each group. 109 differentially expressed genes related with pancreatic cancer metastasis were screened, of which 49 were up-regulated and 60 were down-regulated. Functional annotation and pathway analysis revealed differentially expressed genes were mainly concentrated in protein activation cascade, extracellular matrix construction, decomposition, etc In the biological process, it is mainly involved in signalling pathways such as PPAR, PI3K-Akt and ECM receptor interaction. Prognostic analysis showed the expression levels of four genes were significantly correlated with the overall survival time of patients with pancreatic cancer, namely SCG5, CRYBA2, CPE and CHGB. qPCR experiments showed the expression of these four genes was decreased in both the primary pancreatic cancer group and the metastatic pancreatic cancer group, and the latter was more significantly reduced. Pancreatic cancer metastasis is closely related to the activation of PPAR pathway, PI3K-Akt pathway and ECM receptor interaction. SCG5, CRYBA2, CPE and CHGB genes are associated with the prognosis of pancreatic cancer, and their low expression suggests a poor prognosis.

K562 cell-derived exosomes suppress the adhesive function of bone marrow mesenchymal stem cells via delivery of miR-711.

A failure of bone marrow mesenchymal stem cells (BM-MSCs) to adhere to hematopoietic cells is an essential cause of the progression of chronic myelogenous leukemia and is also a cause of failure of bone marrow (BM) transplantation, but the exact mechanisms of this have not been fully elucidated. Recent studies have indicated that microRNAs (miRNAs) are contained in leukemia-derived exosomes and are involved in modulating the BM microenvironment. In this study, we found that K562 cell-derived exosomes transfer miR-711 to BM-MSCs and suppress the adhesive function of BM-MSCs. Using qRT-PCR, we also confirmed a significantly higher level of miR-711 in exosomes derived from K562 cells than in exosomes derived from parental cells. The BM-MSCs co-cultured with exosomes derived from K562 cells showed a lower adhesion rate than did controls. We further demonstrated that exosomal transfer of miR-711 induced decreased adhesive abilities by inhibiting expression of adhesion molecule CD44 in BM-MSCs. In conclusion, our study reveals that K562 cell-derived exosomal miR-711 can be transferred to BM-MSCs and weaken adhesive abilities by silencing the expression of the adhesion molecule CD44.