RESUMEN
Multidrug resistant genes are highly expressed in hepatocellular carcinoma that seriousty affects the effect of chemotherapy. Screening of resistant genes from HCC cells and studying its mechanism of drug resistance will be helpful to improve the effecacy of chemotherapy for hepatocellular carcinoma. Here we described an alternative method called cyclical packaging rescue (CPR). First we constructed a retrovirus cDNA library of hepatoma cells and used it to infect fibroblasts. Then we added drugs to screen survival cells. The survival cells, stably integrated helper-free retroviral libraries, were recovered rapidly after transfection with plasmids expressing retroviral gag-pol and env genes. Through this method, retroviral RNAs were directly repackaged into new infectious virions. Recovered retroviral supernatant was then used to reinfect fresh target cells. When performed in concert with selection using functional assays, cDNAs regulating functional responses could be identified by enrichment through multiple rounds of retroviral library recovery and retransmission. Using CPR, we obtained several cDNAs. After a preliminary detection, we found Ribosomal protein S11 (RPS11), Ribosomal protein L6 (RPL6), Ribosomal protein L11 (RPL11), Ribosomal protein L24 (RPL24) possibly had drug resistant function.