The Effect Of Low Expression Of GPSM2 On The Growth And Chemotherapy Sensitivity Of Pancreatic Cancer

Objective:This experiment established a pancreatic cancer cell line with low expression of G protein signaling modulator 2(GPSM2),and identified successful establishment of cell lines.Then we constructed a nude mouse model of pancreatic cancer with low expression and natural expression of GPSM2.The gemcitabine,a first-line chemotherapy drug for pancreatic cancer,was used as an intervention factor to investigate the effect of low expression of GPSM2 on pancreatic cancer growth and chemotherapy sensitivity.To improve the therapeutic effect of pancreatic cancer and determine the prognosis,find effective indicators and provide new research ideas.Method:Using the GPSM2 low expression lentiviral vector(GPSM2-homo-1211)constructed by Jiangsu Qishi Biotechnology Co.,Ltd.to transfected human pancreatic cancer MIA-PaCa-2 cell line,the obtain GPSM2 low expression pancreatic cancer cell line(shRNA GPSM2)was used as an experimental group cell,negative-sequence recombinant vector(shNC)transfected cell line(shRNA NC)as negative control,human pancreatic cancer MIA-PaCa-2 cell line as blank control group.Using RT-PCR,Western Blot to detect the GPSM2 mRNA and GPSM2 protein expression level about experimental group,control group and negative control group,thereby identifying pancreatic cancer cell lines with low expression GPSM2 successfully constructed.16nude mice were randomly divided into 2 groups(8 in each group),One group of nude mice was inoculated in the right axillary subcutaneously with a 0.2 mL concentration of5×10~6/mL cell suspension of the experimental group to obtain a GPSM2 low expression pancreatic cancer nude mouse model(1 x 10~6cells per nude mouse);the other group of nude mice was inoculated in the right axillary subcutaneously with a 0.2 mL concentration of 5×10~6/mL cell suspension of the blank control group to obtain a GPSM2 natural expression pancreatic cancer nude mouse model(1 x 10~6cells per nude mouse).Two weeks after the nude mouse model was constructed,the GPSM2 low expression group and the GPSM2 natural expression group nude mice were each divided into two groups.One group received intraperitoneal injection of gemcitabine at a dose of 100 mg/KG,three injections per week(Inject once every Monday,Wednesday and Friday)and continuous injection for 4 weeks.The other group received intraperitoneal injection of normal saline at a dose of 100 mg/KG,three injections per week(Inject once every Monday,Wednesday and Friday)and continuous injection for 4weeks.After each injection,observe the growth condition of each group of nude mice and whether there is any unwell reaction,measure and record the long and short diameter of the tumor in each group of nude mice before the first injection of the per week and after 24 h each injection.Kill the nude mice on the third day after the last injection,take out the tumor and measure the long and short diameter(A total of 16measurements).Calculate the tumor volume by the formula of volume V=a~2×b/2(a represents the short diameter of the tumor and b represents the long diameter of the tumor).The tumor growth curve was plotted based on the average volume of nude mice.Result:1.We successfully constructed GPSM2 low expression pancreatic cancer cells and nude mouse models.2.The growth rate of tumor volume and the size of tumor volume in nude mice were GPSM2 natural expression+saline group>GPSM2 natural expression+gemcitabine group>GPSM2 low expression+saline group>GPSM2 low expression+gemcitabine group.The tumor volume of GPSM2 natural expression+gemcitabine group was significantly lower than that of GPSM2 natural expression+saline group(P<0.01).The tumor volume in the GPSM2 low expression+saline group was significantly lower than that in the GPSM2 natural expression+saline group,GPSM2 natural expression+gemcitabine group(all P<0.01).The tumor volume of GPSM2 low expression+gemcitabine group was significantly lower than that of GPSM2 natural expression+gemcitabine group,GPSM2 low expression+saline group(all P<0.01).3.The factorial design analysis of variance analysis of the main effects and interaction effects of each factor showed that:(1)The main effect of injection of gemcitabine on tumor growth inhibition in nude mice was significant(F=52.985,P<0.01).(2)The main effect of low expression of GPSM2 on tumor growth inhibition in nude mice was significant(F=284.253,P<0.01).(3)The interaction between gemcitabine injection and inhibition of GPSM2 expression in suppressing tumor growth in nude mice has not been statistically significant(F=3.871,P>0.05).Conclusions:1.The low expression of GPSM2 had an inhibitory effect on the growth of pancreatic cancer.2.The low expression of GPSM2 had no obvious effect on enhancing the chemotherapy sensitivity of pancreatic cancer.3.Inhibition of GPSM2 expression combined with chemotherapy at the same time is more effective than inhibiting GPSM2 expression or chemotherapy alone.It also played an important role in increasing the efficacy for pancreatic cancer.May be inhibition of GPSM2 expression combined with chemotherapeutic agents had superimposed effect on inhibiting the growth of pancreatic cancer.