ABSTRACT
Objective@#To investigate the influences of bone marrow stromal cells, components of extracellular matrix and cytokine secreted by stromal cells on the chemotherapeutic sensitivity of acute lymphoblastic leukemia cells to cytosine arabinoside (Ara-C).@*Methods@#The co-culture model of acute lymphoblastic leukemia cell Sup-B15 and bone marrow stromal cell OP9 was constructed. Sup-B15 cells were cultured alone or co-cultured with OP9 cells, inactivated OP9 cells, the conditional medium (CM) of co-cultured OP9 cells and Sup-B15 cells, the CM of OP9 cells alone or Sup-B15 cells alone, respectively. The effects of different concentrations of Ara-C on the proliferation of each Sup-B1 cell group mentioned above were detected by cell counting kit-8 (CCK-8) method. The effects of different concentrations of Ara-C on the apoptosis of each group were detected by flow cytometry (FCM). The expressions of Bcl-2 protein in each group were detected by western blot.@*Results@#The results of CCK-8 test showed that the inhibitory efficiency of Ara-C was in a dose-dependent manner. With different concentrations of Ara-C treatment for 48 hours, the half maximal inhibitory concentrations (IC50) of Sup-B15 and OP9 co-cultured group, Sup-B15 and inactivated OP9 co-cultured group were 0.510 and 0.339 μg/ml, respectively, significantly higher than 0.091 μg/ml of Sup-B15 cultured alone group (P<0.05). The IC50 of CM of Sup-B15 and OP9 co-cultured group was 0.204 μg/ml, significantly higher than 0.087 μg/ml of the CM of OP9 cultured alone group (P<0.05) and 0.097 μg/ml of the CM of Sup-B15 cultured alone group (P<0.05). The results of flow cytometry showed that with 0.10 μg/ml Ara-C treatment for 24 hours, the early apoptotic cell percentages of Sup-B15 and OP9 co-cultured group, Sup-B15 and inactivated OP9 co-cultured group and Sup-B15 cultured alone group were (6.67±2.19) %, (8.95±3.04) % and (20.46±2.63) %, respectively. The early apoptotic cell percentages of Sup-B15 and OP9 co-cultured group, Sup-B15 and inactivated OP9 co-cultured group were significantly lower than that of Sup-B15 cultured alone group (P<0.05). The early apoptotic cell percentages of the CM of Sup-B15 and OP9 co-cultured group, the CM of OP9 cultured alone group and the CM of Sup-B15 cultured alone group were (11.16±2.97)%, (22.08±2.71)% and (19.25±1.57)%, respectively, the former two of which were significantly lower than the last one (P<0.05). The results of western blot showed that the relative expression levels of Bcl-2 protein of Sup-B15 cultured alone group, Sup-B15 and OP9 co-cultured group, Sup-B15 and inactivated OP9 co-cultured group, the CM of Sup-B15 and OP9 co-cultured group, the CM of OP9 cultured alone group and the CM of Sup-B15 cultured alone group were 1.00±0.00, 1.53±0.03, 1.38±0.01, 1.26±0.05, 1.03±0.01 and 0.98±0.02, respectively. The expression levels of bcl-2 protein of three combined groups were significantly higher than that of Sup-B15 cultured alone group (P<0.05). while no statistically significant difference was observed between the CM of OP9 cultured alone group and the CM of Sup-B15 cultured alone group (P>0.05).@*Conclusion@#Bone marrow stromal cell OP9, the components of bone marrow extracellular matrix and cytokine secreted by stromal cells are involved in the induction of the chemotherapeutic resistance of Sup-B15 cells to Ara-C.
ABSTRACT
Objective:To study the expression of Ets-1 and VEGF in breast invasive ductal carcinoma (IDC) tissues,and to analyze its correlation with clinicopathologic characteristics of IDC. Methods:Forty breast IDC tissues and their adjacent normal tissue samples were obtained from clinical diagnosed breast IDC patients after surgery. Expression of Ets-1 and VEGF protein and mRNA was examined by immunohistochemistry and RT-PCR. Results:(1)Expression of Ets-1 and VEGF protein in breast IDC tissues was significantly higher than that in adjacent normal tissues (P