Decreased Tumorigenic Potential Of EphA2 Over-expression In Mouse Model Of Breast Cancer Following Treatment With RAd-T Express EphrinA1-Caspase3

Background:Investigations and studies have been found by humans for centuries,and are now recognized as very complex diseases.The breast cancer is one of the most common tumor types.It often occurs in women,mainly,but it may be occurred sporadically in men.The disease is caused by losses of the control mechanisms that control cell division,which in turn leads to unlimited cell growth in the body.The breast cancer is growing at a relatively fast rate in China.It has surpassed ovarian cancer that the malignant tumor with the highest morbidity and fatality rate in women.What is more,the onset age is gradually becoming younger.At present,the clinical treatment of breast cancer also adopt to use the traditional single surgery,combined with various treatment methods,such as radiotherapy and chemotherapy that according to the condition,so as to achieve the therapeutic effect and improve the life span.As the treatment of the traditional mode can not solve the problem of the resistance of drug and metastasis and also recurrence of cancer effectively.Considering the study of targeted cancer therapy of strategy,therefore,researchers is trying to develop new patterns that associated with the concept of biological treatment of experimental research approach,and the view have has also been used for the treatment of breast cancer range and by positive research.The new research direction（i.e.,molecular target therapy）in specific side effects or adverse reactions to the obvious advantages,through considered potential targets associated with malignant cell proliferation and then cancer,specifically targeted stem cells malignant proliferation.Obviously,this be reversed the malignant biological behavior is operating at the molecular level.Tyrosine kinases,as signaling molecules,play an indispensable role in signaling in a variety of biological,especially mammalian,physiological processes,such as cell migration,the cell-cell adhesion and blood vessel formation.Eph,the ligand of ephrin,is the largest subgroup of tyrosine kinase receptor family that has been studied,and plays an vital role in the mechanism and evolution of cancer through receptor ligand interaction mediated signaling.Ephrin-A1is one of the ligands with high affinity for EphA2.And Ephrin-A1 is one of the ligands with high affinity for EphA2,and also the Ephrin-A1 is one of the ligands with high affinity for EphA2.As a key factor affecting breast cancer,its signal transduction has also been found in the next way of breast cancer.Existing research results have confirmed that receptor tyrosine kinase-EphA2 is normally expressed in normal tissues and specifically highly expressed in breast cancer tissues,indicating that it has the potential to become a fresh and noteworthy target for breast cancer treatment.In the come into existence mode of biological therapy,cytotoxic drugs inducing apoptosis of cancer cells are used as anticancer chemotherapy drugs,and the targeted of breast cancer of treatment by cytotoxic T cells（Lymphocytes）provides a new thinking way and tendency for the current predicament.Objective:To investigate the inhibitory effect of r Ad-EphrinA1-Caspase3-T lymphocyte on tumorigenic of EphA2 related breast cancer that be constructed by nude mice in situ.Method:BALB/c nude mice（n=35）were inoculated with the obtained mixture of the EphA2 over expressed breast cancer single cells.It through into the mammary fat pads of six week old female mice to establish in situ nude mouse model of breast cancer.Two weeks later,after the tumor volume reached about 0.3cm³,30 mice with tumor tissues of average size were choose and divided into PBS group,T cells group,and T cells infected with adenovirus group,randomly.Tumor dimensions were measured by digital caliper at a given time point on every alternate day,and volume was calculated using the following formula:volume=length×width²×0.52.By the end of the experiment,the live little mice to death in each group（broken neck）.T lymphocytes（expressing green fluorescent protein）were observed by frozen sections of exfoliated tumors,and fluorescence microscopy was used to detect the expression of tumor markers in collected tumor tissues.After the above orthotopic transplantation,another 3 groups of mice of breast cancer model were selected and subcutaneous tumor tissue homogenates of nude little mice were obtained every 2 or 3 days.EphrinA1-Caspase3 content was detected by Enzyme linked Immunosorbent Assay.Result:1)In vivo analysis demonstrated that One week after the breast cancer cells were inoculated in model of nude little mice,the subcutaneous tumor could be felt by hand,which proved the model of breast cancer in nude mice with over expression of EphA2was successfully constructed.Then at 5th day after the treatment,the groups differed,tumor volume to dramatical,on On day 6th,r Ad-T treatment group compared with PBS group/pure T cells group significant difference,statistically significant（Р<0.05）.And simple T cells against PBS group found that the tumor growth slower volume slightly smaller,but the difference was not statistically significant（Р>0.05）.2)On the 2^nd day,The secretion of ephrin A1-Caspase3 protein in T cells infected with adenovirus group was detected in the tissue homogenate test.And the secretion reached the peak on the 8^thday,and then weakend with time.EphrinA1-Caspase3protein was not detected at any time point in the simple PBS group and the pure T cells group.3)Sprinkled green fluorescent protein could be observed in the tumor tissue sections of the treatment group,which proved the presence of EphrinAl-caspase3 secreting labeled T lymphocytes,while no T lymphocytes labeled green fluorescent protein were detected in the PBS group and the simple T lymphocyte group.4)Compared with the PBS group/T cells group,the protein expression of apoptosis marker-Caspase3 was increased and the protein expression of proliferation marker-Ki67 was decreased in the adenovirus transfected tumor tissues.Conclusion:EphrinA1-Caspase3-T lymphocyte is potent and it specifically activates Caspase3 related cell apoptosis,which forms the basis for further development of clinically application of EphA2-targeted cytotoxic effect.