AhmadRezaRezaeian¹, Fatemeh Khatami², Mohammad Vaseei³, Mohammad Reza Akbari⁴, Akram Mirzaei², Keykavos Gholami², Seyed Mohammad Kazem Aghamir^2*

¹ Shahid Beheshti University of Medical Sciences, Tehran, Iran

² Urology Research Center, Tehran University of Medical Sciences, Tehran, Iran

³ Pathology Department, Shariati Hospital, Tehran University of Medical Sciences, Tehran, Iran.

⁴Women’s College Research Institute, Women’s College Hospital, University of Toronto, Canada; Institute of Medical Science, Faculty of Medicine, University of Toronto, Canada

Abstract

Background:

Exosomes are nanoscale vesicles generated by cells for intercellular communication. We aimed to elucidate the role of mesenchymal stem cells (MSC-exosomes) on epithelial-to-mesenchymal transition (EMT), angiogenesis, and apoptosis genes expressions.

Material and Methods:

Four different cell lines were employed including ACHN, 5637, LNCaP, and PC3 as the well-known representatives for renal, bladder, hormone-sensitive, and hormone-refractory prostate cancers, respectively. The cell lines were treated with different concentrations of mesenchymal stem cells-derived exosomes to find effective doses and IC50 values. Percentages of apoptotic cells were evaluated by Annexin/P.I. staining. Micro Culture Tetrazolium Test (MTT) assessed the proliferative inhibitory effect; and mRNA levels of prostate biomarker (KLK2), EMT (E-cadherin and Snail), angiogenesis genes (VEGF-A and VEGF-C), apoptosis genes (BAX, BCL2, and P53) and Osteopontin variants (OPNa, b, and c) were investigated by the real-time PCR method.

Results:

All 5637, LNCaP, and PC3 following treatment with exosomes illustrated specific responses with changes in the expression of different genes. The increased TP53 and decreased BCL2 expressions were seen in 5637, LNCaP, and PC3. In PC3, OPNb and OPNc have increased more than P53, and in LNCap, the increase was in VEGF-c.   In 5637 cells, more than TP53 and BCL2 changes, two other genes, VEGFa and BAX, have decreased, suggesting the anti-apoptotic and anti-angiogenic effects of exosomes. In the kidney tumor cell line, no significant gene expression change of ten targeted genes was seen.

Conclusions:

MSC-exosomes therapyhas augmented some interesting anti-tumor effects on prostate, bladder, and kidney cancer cell lines. This effect which probably originates from exosomes’ potency to induce apoptosis and inhibit the proliferation of cancer cells simultaneously, was more substantial in bladder cancer, moderate in prostate cancer, and mild in renal cancer.

Keywords:

Exosome; Cancer cells; Apoptosis; Angiogenesis; EMT.