Antagonizing miR-128 abrogates chemoresistance-associated metastasis and is therapeutic in non-small cell lung cancer [miRNA]

This experiment is designed to screen miRNAs that are deregulated during chemoresistance-associated metastasis of lung cancer cells. Chemoresistant metastatic in vivo tumor model of A549-luc-Vector cells was established after four rounds of cisplatin (CDDP) treatments compared to corresponding control solvent treatments. Upon examining profiles of miRNA expression differential between tumor-derived cultured cells from the Ctrl-4th and CDDP-4th treatments, most markedly upregulated and downregulated miRNAs in chemoresistant, metastatic A549-luc-CDDP-4th cells were identified. In order to establish a chemoresistant in vivo tumor model, after inoculation of A549-luc-Vector cells, cisplatin (CDDP) or control solvent was intraperitoneally (i.p.) injected six rounds in a two-week period and cells were isolated from corresponding resultant tumors, cultured and re-transplanted into syngeneic mice to receive the next round of treatment. In our experimental model, human lung cancer xenografts developed chemoresistance in the third round of CDDP treatment (CDDP-3rd) and chemoresistance-associated metastases following the fourth round of treatment. Tumor-derived cultured cells from Ctrl-4th and CDDP (cisplatin)-4th treatment were subjected to miRNA array (Agilent-031181 human miRNA (8*60k) V16.0) analysis, with two biological replications for each treatment.