Abstract 1185: Regulation of neutral amino acid transporters gene expression profile in non-small cell lung cancer

Abstract

Abstract INTRODUCTION: In a recent study, we showed that SLC1A5, a key glutamine (Gln) transporter, regulates tumor growth and survival in NSCLC. Here we sought to characterize the expression of other Gln transporters in lung cancer and to test whether the inhibition of SLC1A5 activity induced a change in expression of other amino acid transporters in NSCLC. METHODS: Neutral amino acid transporters reported in the cancer literature were evaluated in publically available lung cancer gene expression datasets. Among those, SLC38A1, SLC1A4, SLC1A5, SLC7A5, SLC7A11, SLC7A8 were selected for the in vitro validation. The expression of these genes was evaluated in two lung squamous carcinoma cell lines (HCC15, H226) and one adenocarcinoma cell line (A549) by RT-PCR and then quantified by qPCR, using SYBR® Green Supermix protocol. The expression of the same genes was assessed in response to transient SLC1A5 knockdown in HCC15 and A549 cell lines by qPCR. RESULTS: Amino acid transporters SLC38A1, SLC1A5, SLC7A5 and SLC7A11 are expressed in NSCLCs, a finding that was confirmed in the three cell lines studied. SLC1A4 was found to have the lowest expression and SLC7A8 no expression in any of cell lines. In response to SLC1A5 transient knockdown in A549, SLC38A1, SLC1A4 and SLC7A5 were significantly up-regulated (p<0.02); in contrast, in HCC15, SLC38A1, SLC1A4 and SLC7A5 were significantly down-regulated (p<0.02) and SLC7A11 was up-regulated (p<0.13). CONCLUSION: Our results show that SLC38A1, SLC1A5, SLC7A5 and SLC7A11 have the highest level of gene expression in NSCLC. We identified a possible compensatory mechanism to satisfy Gln transport and cellular function upon SLC1A5 silencing involving different transporters in a cell-specific manner. Compensatory mechanisms in response to SLC1A5 knockdown deserve further investigation as it may have implications in strategies aiming at inhibiting its activity. Further expression, localization and functional studies will follow to better understand changes occurring in lung cancer progression. Key words: Non-small cell lung cancer, SLC1A5, expression, amino acid, transporters Citation Format: Pierre P. Massion, Maria Senosain, Mohamed Hassanein, Xiangming Ji, Jun Qian, Megan hoeksema. Regulation of neutral amino acid transporters gene expression profile in non-small cell lung cancer. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 1185. doi:10.1158/1538-7445.AM2015-1185