NIN/RPN12 binding protein 1 (NOB1p) encoded by NOB1 has been found to be an essential factor in 26S proteasome biogenesis which participates in protein degradation. However, the functions of NOB1 in non-small cell lung cancer cells are largely unknown. In the present study, lentivirus-mediated NOB1 shRNA transfection in two non-small cell lung cancer cell lines (A549 and H1299) was accomplished, as determined by fluorescence imaging. Downregulation of NOB1 expression was confirmed by real-time PCR and western blotting. NOB1 silencing resulted in a significant decline in the proliferation and colony formation capability of non-small cell lung cancer cells. Moreover, flow cytometry showed that A549 cells were arrested in the G0/G1 phase of the cell cycle after NOB1 suppression. Furthermore, depletion of NOB1 resulted in a significant decrease in CDK4 and cyclin D1 expression. These results suggest that NOB1 may act as an important regulator in non-small cell lung cancer growth and could be a therapeutic target of non‑small cell lung cancer.