Abstract:

Objective To discuss the potential therapeutic effect of CA3 combined with JSI-124 on lung cancer subcutaneous allografts in the mice and its influence on the lymphocytes， and to clarify its possible mechanism. Methods Four kinds of non-small cell lung cancer （NSCLC） cells （LLC， H460， H292 and LA795） were used. The cell counting kit-8 （CCK-8） method and flow cytometry were used to detect the survival rates and apoptotic rates of the four kinds of NSCLC cells before and after CA3 treatment； the morphology of four kinds of NSCLC cells was detected by trypan blue staining； carboxyfluorescein succinimidyl ester （CFSE） staining was used to detect the expression level of CFSE in splenic lymphocytes； flow cytometry was used to detect the apoptotic rate of splenocytes. The LLC cells at logarithmic growth phase were subcutaneously inoculated into the C57BL/6 mice to establish subcutaneous allograft models. After successful modeling， the mice were were randomly divided into control group， CA3 group， JSI-124 group， and CA3+JSI-124 group， with 4 mice in each group. The mice in control group were intraperitoneally injected with phosphate buffer saline （PBS） containing dimethyl sulfoxide （DMSO）， the mice in CA3 group and JSI-124 group were intraperitoneally injected with CA3 and JSI-124 at a dose of 1 mg·kg^-1， respectively； the mice in CA3+JSI-124 group were intraperitoneally injected with 1 mg·kg^-1 CA3 and 1 mg·kg^-1 JSI-124. At 24 h after the last administration on day 18， the mice were sacrificed by cervical dislocation， and the tumor tissues were removed； the thymus and spleen were taken， and the tumor mass， spleen mass and thymus mass were weighed. Flow cytometry was used to detect the phenotypic changes of lymphocytes in spleen and thymus of the tumor-bearing mice. Results The in vitro experiment results showed that CA3 exhibited time- and dose-dependent inhibitory effects on the four kinds of NSCLC cells and splenic lymphocytes， and the optimal inhibitory effect on proliferation was achieved after treatment with 2 mmol·L^-1 CA3 for 72 h. Compared with control group， the apoptotic rates of four kinds of NSCLC cells in 2 mmol·L^-1 CA3 group were increased at 72 h after treatment （P<0.01）. Compared with control group， the proliferation rate of splenic lymphocytes in 2 mmol·L^-1 CA3 group was decreased （P<0.01）， and the apoptotic rate of splenocytes was increased （P<0.01）.The in vivo experiment results showed that compared with control group， the difference in tumor mass of mice in CA3 group was not statistically significant （P>0.05）， while the tumor mass of the mice in CA3+JSI-124 group was decreased （P<0.01）. Compared with control group， the differences in the percentages of T lymphocytes， B lymphocytes and T lymphocyte subsets in spleen， and T lymphocytes and T lymphocyte subsets in thymus of the mice in CA3+JSI-124 group were not statistically significant （P>0.05）. Conclusion CA3 can inhibit the proliferation of NSCLC cells and induce apoptosis in vitro， but it has inhibitory effect on splenic lymphocytes. The combination of CA3 and JSI-124 can significantly inhibit the growth of lung cancer subcutaneous allografts in the mice， with no significant effects on the mass of thymus and spleen， or the T lymphocytes and B lymphocytes in the thymus and spleen.

Key words: Carcinoma，non-small-cell lung, CA3, JSI-124, Lymphocyte, Thymns, Spleen