The Function Research Of Glutamine Transporter SLC1A5 In The Non-small Cell Lung Cancer With Mutant And Wild Types Of EGFR

Objectives: Lung cancer is the highest mortality and morbidity of cancer in the worldwide,and non-small cell lung cancer(NSCLC)is the most frequently seen type of lung cancer,accounting for approximately 85% of all cases,causing a great threat to the human health.SLC1A5 is a kind of glutamine transporters located on the cell membrane as a transmembrane protein,its function is to transport extracellular glutamine into the cell,providing the substrates for cell's metabolism.It is highly expressed in many cancer,including non-small cell lung cancer.Cancer cells are deeply dependent on glutamine,in order to maintain the growth and proliferation of cancer cells.It also reported previously that SLC1A5 can affect the growth and survival of non-small cell lung cancer.The further clinical studies also shown that the expression of SLC1A5 is an important indicator of the prognosis of lung adenocarcinoma.In the patients without EGFR mutations,the higher the expression level of SLC1A5,the worse the prognostic effect.It reported that there are interactions between the SLC1A5 and the EGFR,but the mechanism and downstream signaling pathway are still not clear.In this study,we will further study the function of SLC1A5 in the non-small cell lung cancer with mutant and wild-type EGFR,and explore the relationship between SLC1A5 and EGFR in non-small cell lung cancer,the correlation between the function of SLC1A5 and EGFR's mutations,and the molecular mechanism.Methods:(1)HCC827,HCC827 ER,PC-9,NCI-H1975,A549 and H358 cell lines were selected for the research.HCC827,HCC827 ER,PC-9 and NCI-H1975 cells are cancer cells carrying EGFR's mutations,A549 and H358 are cancer cells with wild-type EGFR;(2)Western blotting was used to detect the protein levels of SLC1A5 under the different pretreated conditions;(3)Analyze the growth condition of non-small cell lung cancer after treated with the inhibitor of SLC1A5,and detect the protein levels in the EGFR/mTOR pathways;(4)Analyze the growth condition of non-small cell lung cancer after knockdown the gene of SLC1A5,and detect the protein levels in the EGFR/mTOR pathways.Conclusion:(1)The protein level of SLC1A5 was upregulated in the resistant cells;(2)GPNA reversed the resistance of HCC827 ER cells and its effect beyond 968;(3)The dependence of NCI-1975 cells on SLC1A5 was significantly less than that of HCC827 ER cells;(4)The protein expression level of SLC1A5 in wild-type EGFR cells was significantly higher than that of in mutant type;(5)There was no effect on the growth of wild-type cell lines after knockdown the gene of SLC1A5 by SiRNA,but still significantly inhibited the growth of HCC827 ER resistant cells;(6)SLC1A5may have interaction with mutant-type EGFR,but no interaction with wild-type EGFR.