The Empirical Study Of The Effect On Lung Adenocarcinoma Cell A549 Of Ectogenesis P53 Gene Introduction Associated With Radiotherapy In Different Time

PrefaceLung cancer was divided into 2 types:small cell lung cancer(SCLC) and non-small cell lung cancer(NSCLC),80% of lung cancer is non-small cell lung cancer,which includes adenocarcinoma(25%), squamous-carcinoma(35%), undifferentiated carcinoma of megacell(15%) and other unusual sub-types.Operation is a preferred therapeutic method, but 70-80% of the patients who are diagnosed as lung cancer exactly, have been in ragional advanced stage or advanced stage, and lost their opportunity of radical operation. So radiotherapy is one of the most important methods for unrecectable carcinoma,and radiosensitivity is a key point for the effect.It's important to enhance the radiosensitivity to combine with various kinds of antineoplastic drugs and biology instruments when using ionizing radiation to treat tuomor.In the recent years,with the development of oncomolecularbiology,clinicians have paid closed attention to utilize the gene drugs for enhancing the radiosensitivity.Now we have found that many genes,such as p53,Rb,ras et al,are concerned with the occurrence and development of oncoma and sensitivity of radiotherapy.Among them,p53 gene is studied and researched abundantly,and it has powerful function against tumor.The p53 gene reside in normal cells,and has relationships with human tumors and radiosensitivity. With full development,it has important roll in enhancing radiosensitivity,and has been already used in clinic.PurposeIn clinical work, we transfer wild type p53 gene carried by adenovirus vector into the tumor cells, associated with radiotherapy, in order to gain the biggest clinical profit. But radiotherapy effect p53 gene expression and lethal effect, it is still unknown that haw to arrange the drug time and the radiotherapy time, and it's urgent to know. This study aim to figure out the effect on p53 protein expression and cell lethal effect after introduction of recombinant human adenovirus p53 associated with radiotherapy in different time in A549 lung adenocarcinoma cell line.MethodInject wild type p53 gene carrid by recombinant human adenovirus vector into human lung adenocarcinoma cell line A549 with p53 gene partially defect, associated with radiation exposure (4Gy) in different time after the introducion, and detecting cell growth suppression through MTT method, detecting cell apoptosis though flow cytometer, and detecting wild type p53 protein expression trough western blot.ResultThe groups that radiation exposure associated at 6h,24h,and 48h after adenovirus p53 introduction turn out to be stronger cell growth suppression than control group with introduction only, instantly radiation exposure with introduction group, and radiation 3h after introduction group, P<0.05.With the internal time prolong, the rate of cell apoptosis increases from 30.1% to 52.0%,in wich the least group is drug and radiotherapy instantly. In the latter three groups,p53 protein express obviously weaker than former three. Although group that radiation exposure at 48h after introduction shows the highest protein expression, it's no statistical signification with groups of 6h and 24 radiation exposure after introduction(P>0.05).ConclusionRadiotherapy associated with adenovirus p53 gene transfer produce the maximum lethal effect if we chose to associate radiotherapy 6h-48h after introduction, but not the introduction instantly. Otherwise, it will reduce the p53 protein expression, which is lead to less tumor cell lethal effect directly and less radiosensitivity indirectly.