Comparative Study Of Inhibition Of Breast Cancer Cells By Bispecific Oncolytic Adenovirus And Chemotherapeutic Drugs

Breast cancer is one of the most concerned female cancer problems in the world.Although the incidence of breast cancer in China is not high,it should not be ignored.Breast cancer has gradually become a malignant tumor disease that jeopardizes the physical and mental health of Chinese people.There are many ways to treat breast cancer,but the most commonly used are chemotherapy and radiotherapy.Although these two methods are effective,the accompanying side effects are also large,so that patients cannot obtain a high quality life guarantee.This study aims to provide a new approach to the treatment of breast cancer through new biotherapeutic approaches.There are two basic types of breast cancer: triple-negative and hormone-dependent,which pass triple negative breast cancer cells(MDA-MB-231),estrogen receptor-positive breast cancer cells(MCF-7)and normal breast epithelial cells(MCF-10A),a comparative study of drugs and bispecific oncolytic adenovirus tumor inhibition experiments.The recombinant adenoviruses(Ad-VT,Ad-T,Ad-VP3 and Mock)constructed by our group use the RAPAd.I packaging system,and Ad-VT(Ad-Apoptin-hTERTp-E1A)is activated by tumor-specific The(hTERTp,human telomerase reverse transcriptase)initiates the E1 A gene(viral replication essential gene)and the cytomegalovirus(CMV)promoter to activate the apoptin gene(Apoptin),so Ad-VT acquires tumor Specific killing ability and specific replication ability of the tumor;The control viruses were Ad-T(Ad-hTERTp-E1A),Ad-VP3(Ad-CMV-Apoptin)and Mock.The two drugs used in this study were doxorubicin(broad-spectrum chemotherapy drugs)and tamoxifen(blocking estrogen receptor drugs).In this experiment,the in vitro inhibitory effects of two drugs and recombinant adenovirus on MCF-7,MDA-MB-231 and MCF-10 A were studied.Screening of MCF-7Luc and MDA-MB-231 Luc cell lines capable of stably expressing luciferase in human breast cancer cells,detecting luciferase activity,in vitro imaging and biological properties,and drugs and recombinant adenovirus in vitro against fluorescein Inhibition of Enzyme-Labeled Human Breast Cancer Cells.The experiment will also establish a BALBC/C nude mouse luciferase-labeled subcutaneous tumor model to study the inhibitory effect of recombinant adenovirus and two anti-MCF-7Luc and MDA-MB-231 Luc cell drugs on traditional tumors and dissolve The inhibitory effect of tumor adenovirus on breast cancer cells was compared.The results showed that recombinant adenovirus had strong inhibitory effects on two breast cancer cells(MCF-7,MDA-MB-231)by WST-1,Hoechst,JC-1 and AnnexinV-FITC/PI flow cytometry.The inhibitory effect was Ad-VT>Ad-T>Ad-VP3>MOCK(P<0.001),which had a high inhibition rate of 80% at 72 hours and less inhibition on normal mammary epithelial cells.It is only 20% at 72 hours.The inhibition of doxorubicin against breast cancer cells and mammary epithelial cells was extremely strong,and the inhibitory effect was 5 μg/mL>0.5 μg/mL>0.05 μg/mL,and the inhibition rate was higher than 80% at 72 hours.When the concentration of tamoxifen was 15 μmol/L,MCF-7 cells and MDA-MB-231 cells were differentiated by inhibition rate.When the concentration is lower than the concentration,the inhibition rate is not significant.At 15 μmol/L,the inhibition rate of MCF-7 cells was 21% at 24 hours and 10% for MDA-MB-231 cells;The inhibition rate for MCF-7 cells was 43% at 48 hours,19% for MDA-MB-231 cells,75% for MCF-7 cells at 72 hours,and 35% for MDA-MB-231 cells.Tamoxifen also has a strong inhibitory effect on mammary epithelial cells at high concentrations.The highest activity was obtained by Clone6 of MCF-7 cells by plasmid transfection and G418 pressure screening and detection of luciferase activity;MDA-MB-231 cells obtained the most active Clone36;in vitro imaging experiments confirmed the linear relationship between the number of Clone6 and Clone36 cells and their luminescence intensity,and the cell growth characteristics were confirmed by the identification of cell biological characteristics.And the cell cycle has no significant effect;The inhibitory effects of three drugs on MCF-7Luc and MDA-MB-231 Luc cells were confirmed by WST-1,Hoechst,JC-1 and AnnexinV-FITC/PI flow cytometry;three drugs were found for MCF-7Luc and MDA.The effect of-MB-231 Luc cells was consistent with the effects of MCF-7 and MDA-MB-231 cells.The subcutaneous tumor-bearing model of nude mice was established by subcutaneous inoculation of MCF-7Luc and MDA-MB-231 Luc cells on the right hind limb of BALB/c nude mice.Ad-VT has a significant anti-tumor effect,which can prolong the average survival rate of mice;doxorubicin can effectively inhibit the size of tumors,but the life cycle is shorter;Tamoxifen has a strong anti-tumor effect on the nude mouse model established by MCF-7Luc cells,but has a poor anti-tumor effect on the nude mouse model established by MDA-MB-231 Luc.