Knockdown of Mgat5 inhibits CD133+ human pulmonary adenocarcinoma cell growth in vitro and in vivo.

ABSTRACT

PURPOSE: In spite of many therapeutic advances, the prognosis of lung cancer remains poor. Therefore, understanding the molecular mechanisms underlying cancer progression, invasion and metastasis is needed. Accumulating evidence indicate that N-acetylglucosaminyltransferase V (Mgat5 or GnT-V) is involved in cancer development. The purpose of this study was to characterize the expression and function of Mgat5 in CD133+ pulmonary adenocarcinoma cells. METHODS: CD133+ pulmonary adenocarcinoma cells were separated by magnetic activated cell sorting (MACS) from excised pulmonary adenocarcinoma specimens from 10 patients. Expression of Mgat5 in CD133+ cells was detected by fluorescent quantitative RT-PCR (FQRT-PCR) and Western blot. Subsequently, CD133+ cells were transfected with specific siRNA of Mgat5 to evaluate the effects of Mgat5 inhibition on cancer cell growth in vivo and in vitro. RESULTS: Expression of Mgat5 was 1.2-fold and 1.4-fold higher in CD133+cells than in CD133- cells detected by FQRT-PCR and Western Blot, respectively (p < 0.05). The L-PHA binding assay also showed higher reactivity in CD133+ cells than in CD133- cells. In addition, Mgat5-specific siRNA efficiently knocked down the expression of Mgat5 in CD133+ cells. Interestingly, downregulation of Mgat5 resulted in significant inhibition of cancer cell growth in vitro and in vivo. CONCLUSION: Mgat5 is expressed at a relatively high level in CD133+ lung adenocarcinoma cells, and knockdown of Mgat5 in CD133+ cells inhibits cancer cell growth both in vitro and in vivo. These findings suggest Mgat5 may play an important role during oncogenesis, identifying a potential therapeutic target for pulmonary adenocarcinoma.