OBJECTIVE To study the effects of caspase recruitment domain membrane-associated guanylate kinase protein 1 (CARMA1) knock-down using RNAi technology on cell proliferation, colony forming, invasion and metastasis of the K562 cells. METHODS K562 cells with stably-silenced CARMA1 gene was constructed by lentivirus-mediated RNAi technology. CARMA1 mRNA and protein levels were respectively detected by reverse transcription PCR (RT-PCR) and Western blotting. Cell proliferation was analyzed by trypan blue exclusion; colony forming was detected by colony forming assay; invasion and metastasis in vitro were determined with Transwell® assay with or without matrigel. Signaling pathway molecules were detected by RT-PCR and Western blotting. RESULTS Six cell lines with knocked-down gene were successfully constructed. Of them, one was negative control (K562/sh-eGFP), and the other five were CARMA1-silenced cells. K562/shCARMA 1-93 showed the greatest inhibition of CARMA 1 gene and protein expressions. Trypan blue exclusion and colony forming assay showed that the ability of cell proliferation and colony forming were significantly suppressed in K562/shCARMA 1-93 (P<0.01). Compared with blank control K562 and negative control K562/sh-eGFP, the growth inhibition rates were respectively 29.3% and 28.6%; the colony forming inhibition rates were respectively 37.6% and 34.1%; Transwell® assay with or without matrigel showed that the number of K562/shCARMA1-93 which passed through the membrane was obviously lower than that of the control group (P<0.01). The expressions of nucleic transcription factor-κB (NF-κB) and early growth response 1 (EGR1) were reduced following the inhibition of CARMA1. CONCLUSION CARMA1 gene knock-down had an impact on cell proliferation, colony forming, invasion and metastasis of K562 cells, which is possibly related to the inhibition of NF-κB and JNK/EGR-1 signaling pathways.