The Sub-cellular Distribution And Function Of GB1e In Breast Cancer Cells

Gamma-aminobutyric acid (GABA),as one of mammals main neurotransmitter in thebrain, works through the ionic GABAAreceptors、GABACand metabolic type receptorGABA_B. GABA_Breceptors, which belong to heterodimeric G-protein coupled receptors,regulate cell function via the activation G protein and their downstream effects molecules.GABA_Breceptors widely distribute in the brain and it is related to all kinds of neurologicaland psychiatric diseases, Including epilepsy, schizophrenia, drug abuse and so on.Therefore, GABA_Breceptor has become a key targets among the diseases of the nervoussystem. At present, people found that GABA_Breceptors can regulate a wide variety oftumor cells proliferation and migration, but the mechanism is still not very clear. GABA_Breceptor composed of GB1and GB2subunits. GB1has many subtypes and the mRNA ofGB1e excluding transmembrane area and intracellular area are widely present in theperipheral organization and tumor cell lines. Literature shows that GB1e express in thenormal peripheral organization. However, there is no report about GB1e in tumor cells.This paper test the cell distribution of exogenous GB1e in human breast cancer cellsMDA-MB-231and MCF-7. First, we constructed various GB1e plasmid with differentlabels, Including pEGFP-N1-GB1e-GFP, pEGFP-N1-HA-GB1e andpEGFP-N1-GB1e-3×Flag; Secondly, we constructed GB1e stable expression human breastcancer cell lines: MDA-MB-231/HA-GB1e�'�MCF-7/HA-GB1e. The results of ELISAsuggest that GB1e could not express on the cell membrane surface of MDA-MB-231andMCF-7. Confocal images show that GB1e distributed in the cytoplasm. IP could detectGB1e can be secreted into the cell medium. In addition, GB1e secreted into medium canenter into cytoplasm by phagocytosis. Baclofen can enhance the Akt phosphorylation levelin HA-GB1e stable expression cell lines, but it have no impact on cell proliferation.Ourpresent work provides the foundation for the subsequent research, which contributes toclarify the biological function of GB1e in tumor cells.