GRM4正向别构调节剂抑制乳腺癌细胞的增殖并促进细胞凋亡

GRM4 positive allosteric modulators inhibit breast cancer cell proliferation and promote cell apoptosis

背景与目的:代谢型谷氨酸受体4(glutamate metabotropic receptor 4,GRM4)在多种恶性肿瘤中高表达并与肿瘤患者的预后相关,但GRM4在乳腺癌中的生物学作用仍不清楚。本研究拟探讨GRM4的两种正向别构调节剂VU0364439及VU0364770对乳腺癌细胞的增殖及凋亡的影响,进而为乳腺癌的靶向治疗提供思路。方法:在体外培养的乳腺癌细胞系MDA-MB-231、MCF-7和SK-BR-3中分别单独加入VU0364439、VU0364770以及联合使用两种试剂,利用Cell Titer-Glo?发光细胞活力测定法定量检测各组乳腺癌细胞系的增殖活性;利用AnnexinⅤ-PI双染法检测各组乳腺癌细胞系的凋亡水平;通过实时荧光定量聚合酶链反应(realtime fluorescent quantitative polymerase chain reaction,RTFQ-PCR)技术测定GRM4基因在6种乳腺癌细胞系中的表达情况,在GRM4表达水平最高的细胞中单独加入或联合使用VU0364439及VU0364770,用RTFQ-PCR检测GRM4基因表达的改变。结果:与对照组相比,单独使用及联合使用VU0364439及VU0364770显著抑制乳腺癌细胞MCF-7、MDA-MB-231和SK-BR-3的增殖水平,并促进MCF-7细胞凋亡现象的发生;联合使用与单独使用VU0364439及VU0364770对乳腺癌细胞增殖及凋亡的作用差异无统计学意义(P>0.05);RTFQ-PCR实验表明GRM4在MCF-7细胞中的表达水平最高;在MCF-7细胞中分别单独使用或联合使用VU0364439及VU0364770均能激活GRM4的表达。结论:GRM4的正向别构调节剂能够抑制乳腺癌细胞增殖并促进细胞凋亡,其作用可能是通过激活GRM4基因的表达引起的,本研究为探索GRM4在乳腺癌中的作用机制以及开发新的乳腺癌靶向治疗方法奠定了基础。

Background and purpose:Glutamate metabotropic receptor 4(GRM4)is highly expressed in many tumors,and its expression is associated with the prognosis of patients.However,the function of GRM4 in breast cancer is still not clear.This study aimed to investigate the effects of positive allosteric modulators VU0364439 and VU0364770 on the proliferation and apoptosis of breast cancer cells,and then provide novel strategies for breast cancer targeted therapy.Methods:VU0364439 and VU0364770 were added solely or in combination into breast cancer cell lines MDA-MB-231,MCF-7 and SK-BR-3.The proliferation activities of these cells were detected using CellTiter-Glo luminescent cell viability assay.AnnexinⅤ-PI double staining was used to detect the apoptosis of breast cancer cells.The expressions of GRM4 gene in six breast cancer cell lines were detected using real-time fluorescent quantitative polymerase chain reaction(RTFQ-PCR).After VU0364439 and VU0364770 were uesd solely or in combination,the expression of GRM4 gene was detected in the cell line with the highest GRM4 expression.Results:Compared with the control group,the proliferations of breast cancer cells MCF-7,MDA-MB-231 and SK-BR-3 were significantly inhibited after VU0364439 and VU0364770 were added solely or in combination.VU0364439 and VU0364770 also promoted the cell apoptosis of these breast cancer cell lines.The inhibitory effect of VU0364439 and VU0364770 on the proliferation of breast cancer cells was not significantly different when they were used in combination(P>0.05).RTFQ-PCR assay showed that the expression of GRM4 was higher in MCF-7 cells.The GRM4 expression could be activated when VU0364439 and VU0364770 were used solely or in combination.Conclusion:GRM4 positive allosteric modulators could inhibit breast cancer cell proliferation and promote cell apoptosis.This biological effect might function by activating GRM4 expression.This study lays the foundation for exploring the effect of GRM4 in breast cancer and developing novel strategies for breast cancer targeted therapy.