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

Abstract

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. 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. 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. 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.