Daintain/AIF-1 promotes breast cancer proliferation via activation of the NF-kappaB/cyclin D1 pathway and facilitates tumor growth

Anticancer effects and mechanisms of Tanshinone ⅡA sulfonic acid in nude mouse xenograft model bearing MKN-45 gastric cancer cells

AIM: To identify the anticancer effects of Tanshinon ⅡA sulfonic acid (TASA) in vivo by the model of nude mice with MKN-45 gastric cancer cells transplanted subcutaneously.

METHODS: MKN-45 human gastric cancer cells were grown as xenografts in 24 immunodeficient mice, which were randomly divided into 4 groups. The mice in observation groups were injected intraperitoneally with TASA at 1 mg/kg (low dosage), 5 mg/kg (median dosage) or 10 mg/kg (large dosage) once per day respectively for 2 wk while the mice in the fourth group were injected with sodium chloride as controls. All the nude mice were sacrificed 2 wk later and growth inhibition rates of transplanted tumors were measured by weighing the masses. Apoptosis index was tested by TUNEL assay. Microvascular density (MVD) was marked by CD34 staining. The protein expression levels of hypoxia-inducible factor 1alpha (HIF1α), vascular endothelial growth factor (VEGF) and cyclooxygenase-2 (COX-2) were measured by immunohistochemistry.

RESULTS: Compared with that in the control group, the apoptosis index was significantly increased in the three observation groups (36.02% ± 3.41%, 34.78% ± 3.41%, 30.05% ± 3.41% vs 10.83% ± 0.92%, all P < 0.05). Low-dose TASA suppressed MKN-45 cell proliferation, and the growth inhibition rate was 20.69% ± 1.79%. On the contrary, median- and large-dose TASA promoted the growth of MKN-45 cells, and the growth inhibition rate in large-dose group was -(21.4% ± 2.38%). Compared with that in the control group, MVD and VEGF expression were up-regulated in the observed groups, especially in the median- and large-dose group (8.11 ± 1.011, 10.01 ± 0.89 vs 6.56 ± 0.42; 63628 ± 611, 70957 ± 684 vs 51056 ± 410; all P < 0.05). COX-2 expression had no significant difference between the four groups. HIF1α expression was slightly down-regulated in low-dose TASA group, not significantly; however, it was significantly up-regulated in the median- and large-dose groups as compared with that in the contol group (29468 ± 204, 42227 ± 214 vs 15691 ± 106, P < 0.01 or 0.05).

CONCLUSION: The anticancer effects of TASA in vivo is not so significant as that in vitro. The effect of large-dose TASA may be offseted or even reversed by compensatory up-regulation of HIF expressioin.