RESUMO
This study was purposed to explore the anti-leukemia effect of bacillus calmette-guerin vaccine (BCG) on the human myeloid leukemia cell xenograft models. An animal model was established by inoculating the human myeloid leukemia HL-60 cells into the BALB/c (8 - 10 weeks of age) nude mice. The mice were randomly divided into two groups: control group and experimental group. Nude mice in control group were injected with physiological saline, while those of experimental group were given BCG and inactivated BCG respectively. The tumor growth was assayed by using caliper. The survival time of nude mice was determined. Necrotic extent and morphological changes of tumor were observed and examined by HE staining and immunohistochemical method. The results indicated that on 5th-7th days after tumor inoculated, 2 - 3 mm tumor mass could be observed. The tumor volume increased over the time. HE staining of tumor tissues showed that there were different degrees of tumor necrosis in BCG group and inactivated BCG group. Immunohistochemistry results demonstrated that CD20 positive cells were obviously observed in the necrotic area of BCG group, compared with the control group and inactivated BCG group. It is concluded that human myeloid leukemia HL-60 cells have been successfully transplanted in nude mice, and the systemic metastasis occurs along with the prolongation of time. BCG inoculation can delay the tumor growth and prolong the survival time of nude mice with leukemia, suggesting that BCG has an antitumor effect.