Antisense inhibition of microRNA-21 and -221 targeting side population abolish tumor growth of gemcitabine resistant pancreatic cancer cells

Introduction: Our preliminary studies identified a small population, named as side population (SP) cells in pancreatic cancer cells with stem-like properties, which were able to induce fast and aggressive tumor formation in nude mice. Furthermore, gene expression analysis showed a significant difference in the expression of more than 1300 genes in SP cells, among which the difference in microRNA expression such as miR-21 and miR-221 between SP and non-SP cells were identified as most interesting candidate for further therapy studies.