Exosomal transfer of miR-15b-3p enhances tumorigenesis and malignant transformation through the DYNLT1/Caspase-3/Caspase-9 signaling pathway in gastric cancer

Abstract

Background: Exosomes are essential for tumor growth, metastasis, and are used as novel signaling molecules in targeted therapies. Therefore, exosomal miRNAs can be used in new diagnostic and therapeutic approaches due to their involvement in the development of cancers. However, the detailed biological function, potential molecular mechanism and clinical application of exo-miR-15b-3p in gastric cancer (GC) remains unclear.Methods: miR-15b-3p mRNA levels in tissues, serum, cells and exosomes were analyzed using qRT-PCR assays. qRT-PCR, immunohistochemical and western blotting analyses were utilized for the determination of DYNLT1 expression. The interrelationship connecting miR-15b-3p with DYNLT1 was verified using Dual-luciferase report, western blotting and qRT-PCR assays. Fluorescent PKH-26 or GFP-Lv-CD63 labeled exosomes, as well as Cy3-miR-15b-3p, were utilized to determine the efficacy of the transfer of exo-miR-15b-3p between BGC-823 and recipient cells. Several in vitro assays and xenograft tumor models were conducted to determine exo-miR-15b-3p impact on GC progression.Results: This is the first study to confirm high miR-15b-3p expression in GC cell lines, tissues and serum. Exosomes obtained from 108 GC patient serum samples and GC cell-conditioned medium were found to show upregulation of exo-miR-15b-3p, with the area under the ROC curve (AUC) being 0.820 [0.763-0.876], which is superior to the AUC of tissues and serum miR-15b-3p (0.674 [0.600-0.748] and 0.642 [0.499-0.786], respectively). In addition, high exo-miR-15b-3p expression in serum was found to accurately predict worse overall survival. SGC-7901 and GES-1 cells are capable of internalizing BGC-823 cell-derived exosomes, allowing the transfer of miR-15b-3p. Migration, invasion, proliferation and inhibition of apoptosis in vitro and in vivo were enhanced by exo-miR-15b-3p, by restraining DYNLT1, Cleaved Caspase-9 and Caspase-3 expression.Conclusions: This study identified a previously unknown regulatory pathway, exo-miR-15b-3p/DYNLT1/Caspase-3/ Caspase-9, which promotes GC development and GES-1 cell malignant transformation. Therefore, serum exo-miR-15b-3p may be a potential GC diagnosis and prognosis biomarker, which can be used in precise targeted GC therapy.

<p>Hsa_circ_0000069 Knockdown Inhibits Tumorigenesis and Exosomes with Downregulated hsa_circ_0000069 Suppress Malignant Transformation via Inhibition of STIL in Pancreatic Cancer</p>

“…43 Wei et al indicated that gastric cancer cell-derived exosomal miR-15b-3p led to the malignant transformation of gastric mucosa epithelium cells, promoting cell proliferation and migration. 28 In this study, we found that exosomal hsa_circ_0000069 is secreted by SW1990 cells that can be internalized by HPDE cells. In addition, functional experiments demonstrated that SW1990 cell-derived exosomes promoted the proliferation, migration and cell cycle progression of HPDE cells; however, these changes were reversed by exosomes with downregulated hsa_circ_0000069.…”

“…Wei et al found that exosomal miR-15b-3p was found to be secreted by gastric cancer cells, promoting malignant transformation of gastric mucosa epithelium cells. 28 We then focused on whether exosomal hsa_circ_0000069 involved in the communication between SW1990 cells and HPDE cells. To determine whether SW1990 cellderived exosomes were internalized by HPDE cells, the exosomes were labeled with PKH26 and incubated with HPDE cells.…”

Paeoniflorin Sensitizes Breast Cancer Cells to Tamoxifen by Downregulating microRNA-15b via the FOXO1/CCND1/β-Catenin Axis

“…The overexpression of miR-15b has been confirmed in ovarian cancer 24 and gastric cancer. 25 Moreover, upregulation of miR-15b has been established to promote the resistance of renal cell carcinoma cells to sunitinib. 26 While in tissues collected from patients with highly aggressive BC, the overexpression of miR-15b was also observed.…”

MicroRNA-Related Prognosis Biomarkers from High-Throughput Sequencing Data of Colorectal Cancer

“…Our results indicated that the three miRNAs have potential to be prognostic biomarkers in COAD as well. It is reported that other four miRNAs, miR-29c-5p, miR-15b-3p, miR-130a-3p, and miR-500a-3p, were associated with various cancers but not recommended as prognostic markers [ 30 – 33 ]. Our results suggest that those DEMs (miR-144-5p, miR-145-5p, miR-486-5p, miR-29c-5p, miR-15b-3p, miR-130a-3p, and miR-500a-3p) may serve as potential biomarkers, but their feasibility remains to be investigated.…”