PDCD4 and neoplasm: Injecting the mice transplanted with CR HT-29 cells after tumour formation with a complex of polyethylenimines (PEI)/miRNA-145 increased the miRNA-145 by 50%, suppressed tumour growth and increased the PDCD4 concentration significantly by 10%, demonstrating that miRNA-145 could partially abrogate the effects of chemo resistance in these cells.