Pancreatic cancer cells-derived exosomal long non-coding RNA CCAT1/microRNA-138-5p/HMGA1 axis promotes tumor angiogenesis

Life Sci. 2021 Aug 1;278:119495. doi: 10.1016/j.lfs.2021.119495. Epub 2021 Apr 16.

Abstract

Objective: Pancreatic cancer (PC) cells-derived exosomes could mediate angiogenesis of human microvascular endothelial cells (HUVECs) in PC. Considering that, this research was implemented to figure out the concrete role of PC cells-derived exosomal long non-coding RNA colon cancer-associated transcript-1 (CCAT1) in PC with its regulation on microRNA-138-5p/high mobility group A1 (miR-138-5p/HMGA1) axis.

Methods: PC tissues and normal tissues were resected. PC cells (PANC-1) were interfered with plasmids to change CCAT1 and/or miR-138-5p expression. Exosomes were isolated from PANC-1 cells and co-cultured with HUVECs. The proliferation and apoptosis of PANC-1 and HUVECs were examined. The angiogenic ability of HUVECs was tested in vivo in xenografted tumors and in vitro. CCAT1, miR-138-5p and HMGA1 expression were determined, as well as their interactions.

Results: CCAT1 and HMGA1 expression were raised while miR-138-5p expression was reduced in PC. Silencing CCAT1 disrupted cell proliferation and stimulated apoptosis of PANC-1 cells. Knocked down CCAT1 from PANC-1 cells-derived exosomes promoted apoptosis and repressed proliferation of HUVECs. Down-regulated/up-regulated CCAT1 from PANC-1 cells-derived exosomes destroyed/enhanced the angiogenic ability of HUVECs in vivo and in vitro. CCAT1 mediated HMGA1 through competitively binding to miR-138-5p. Overexpression of miR-138-5p antagonized the effects of up-regulated CCAT1 on angiogenesis of HUVECs in vitro.

Conclusion: It is informative that PANC-1 cells-derived exosomal CCAT1 strengthens angiogenesis of HUVECs through binding to miR-138-5p to elevate HMGA1 expression.

Keywords: Angiogenesis; Exosomes; High mobility group A1; Human microvascular endothelial cells; Long non-coding RNA colon cancer-associated transcript-1; MicroRNA-138-5p; Pancreatic cancer.