Inhibiting Effect And Mechanism Of Lewis Lung Cancer Treated With Docetaxel And Low-dose Radiation In Vivo

[Abstract] Objective:To invesgated the efficacy of docetaxel-based concurrent low-dose radiaochemotherapy in inhibiting the growth of lewis lung cancer in vivo. And explore the maybe corrdination mechanism between docetaxel and low-dose radiation in order to provide a theoretical basis for the clinicl application of docetaxel-based concurrent low-dose radiaochemotherapy.Methods:Treatment was initiated on the10th day after50lewis lung cancer model is established.Every8mice bearing6mm (5.8-6.2mm) xenograft tumor were assigned randomly into cohorts A、B、C、D and E.Group A received0.2ml Saline water intraperitoneally on day1、7、14、21.GROUP B received0.2ml docetaxel(10mg/kg) intraperitoneally on day1、7、14、21. GROUP C delivered radiation on day1、3、7、9、14、16、21、23(50cGy/f bid,DT=8Gy).GROUP D was given induction chemotherapy just the same as Group B and concurrent radiation just like Group C. GROUP E was given induction chemotherapy just the same as Group B,but delivered radiation on day1、7、14、21(2Gy/f,DT=8Gy).The tumor volume was measured before the mice were sacrified on the24th day and draw the mice tumor growth curve.Observe the tumor growth delay and calcaulate the enhancement factors.The characters of apoptosis、cell cyle、erpression of CD44were detected by Flowcytometry.Result:The xenograpy volume of Group D was significantly smaller than other groups.The AGD(absolute growth delay) and normalized growth delay of GroupD was (7.3±1.4)d and (3.4±0.8)d,the enhanctment factor was1.21.The tumor weight of Group B、C、D、E was siginificantly lower than Group A,but there was no significant meaning between Group D and E.The apoptotic rate of Group C、D and E were siginificantely higher than Group A and B, and Group C and D were higher than Group E.The phenomena of G2/M cell cycle arrest was found in all treated Groups,but there was no significant meaning.The CD44expression in Group D was significant than oher groups.Conclusions:docetaxel-based concurrent low-dose radiaochemotherapy can enhance inhibiting growth of lewis lung cancer in vivo.The mechanism may be correlated with inducing cell apoptosis and depressing the activity of cancer sterm cells.