miRNA sequencing of exosomes derived from highly invasive pancreatic cancer cell PC-1.0 and weakly invasive pancreatic cancer cell PC-1

In order to elucidate the molecular mechanism of metastasis and invasion of pancreatic cancer, in previous studies we established a pancreatic adenocarcinoma animal model using Nnitrosobis(2-oxopropyl)amine (BOP) induced Syrian hamsters, which resembles human pancreatic cancer in morphologic, biologic, and immunologic characteristics. We then established a pair of pancreatic cancer cells PC-1 and PC-1.0 using this model. PC-1.0 was obtain through intrapancreatic transplant of PC-1, the weakly invasive pancreatic cancer cells, forms island-like colonies in vitro and produce well differentiated pancreatic adenocarcinoma in vivo, while PC-1.0, the highly invasive one, forms dispersed colonies and produce poorly differentiated tumors in vivo. Condition medium prepared from PC-1.0 cells inhibits PC-1 cells and several other human weakly invasive pancreatic cells (CD11, CD18, HPAF) to form island-like colonies and enhances their invasive properties. While the PC-1 cells do not have the same property. Highly invasive pancreatic cancer cells PC-1.0 may enhance invasive ability of poorly invasive pancreatic cancer cells PC-1 at least partially through transferring of exosomes and that the exosomal miRNAs highly expressed in exosomes of PC-1.0 cells include potential oncomiRs promoting the invasion and metastasis of pancreatic cancer. To test this, PC-1 cells were co-cultured with purified exosomes of PC-1.0 cells to confirm the invasion-promoting effect. Total RNA was extracted from purified PC-1.0 and PC-1 exosomes. Differentially expressed exosomal miRNAs were identified using high-throughput sequencing technology.