Effect of testosterone on growth of P388 leukemia cell line in vivo and in vitro. Distribution of peripheral blood T lymphocytes and cell cycle progression

In transplanted mice, the P388 tumor grew better in castrated than in non castrated (NC) mice. The proportion of CD8+ in the blood was more numerous in NC mice. The T cell subsets (CD4+ and CD8+) were also high in the mice with small tumor tissue (<10 mg). The correlation observed between the tumor weight and T cell subset in PBL and in the mice with small tumors could confirm the important intervention of CD4+ and CD8+ cells to inhibit growth of tumor. Depo-testosterone (DT) injection reduced strongly weight and tumor growth in mice. On top of that, DT administration induced a significant increase in the percentage of blood CD8+ cells in grafted mice. The effect of DT was studied on the cell cycle progression, in tumor tissue of P388 tumor bearing BDF1 mice and in P388 murine leukemia cell line in culture. The cell cycle analysis in tumor tissue showed that DT decreased both the cells in S phase and the proliferating leukemic cells, with accumulation of cells in G0/G1 phase. The testosterone can inhibit the proliferation of leukemic cells with a pharmacological dose (10(-7) M). This growth inhibition, dose and time dependent, was associated with cell cycle arrest; P388 cells accumulates in G0/G1 phase. We also observed a correlation between tumor weight and the percentage of cells in G0/G1 and the relative number of cells in proliferative state (S + G2/M). To conclude, our experiments reported that testosterone prevents the growth of tumor: indirectly by modulation of subsets T cells distribution and directly by the alteration of the cell cycle.

Effect of testosterone on growth of P388 leukemia cell line in vivo and in vitro. Distribution of peripheral blood T lymphocytes and cell cycle progression

In transplanted mice, the P388 tumor grew better in castrated than in non castrated (NC) mice. The proportion of CD8+ in the blood was more numerous in NC mice. The T cell subsets (CD4+ and CD8+) were also high in the mice with small tumor tissue (<10 mg). The correlation observed between the tumor weight and T cell subset in PBL and in the mice with small tumors could confirm the important intervention of CD4+ and CD8+ cells to inhibit growth of tumor. Depo-testosterone (DT) injection reduced strongly weight and tumor growth in mice and DT administration induced a significant increase in the percentage of blood CD8+ cells in grafted mice. The effect of DT was studied on the cell cycle progression, in the tumor tissue of P388 tumor bearing BDF1 mice and in the P388 murine leukemia cell line in culture. The cell cycle analysis showed that DT decreased both the cells in S phase and the proliferating leukemic cells, with accumulation of the cells in G0/G1 phase. The testosterone can inhibit the proliferation of leukemic cells with a pharmacological dose (10-7 M). This growth inhibition dose and time dependent was associated with cell cycle arrest; P388 cells accumulates in G0/G1 phase. We also observed a correlation between tumor weight and the percentage of cells in G0/G1 and the relative number of cells in proliferative state (S + G2/M). Our experiments showed that testosterone prevents the growth of tumor: indirectly by modulation of subsets T cells distribution and directly by alteration of the cell cycle.

Effects of castration, Depo-testosterone and cyproterone acetate on lymphocyte T subsets in mouse thymus and spleen

The effects of testosterone on the relative proportion of Thy 1.2, CD4 (L3T4) and CD8 (Lyt-2) cells in thymus and spleen were studied after castration and administration of Depo-testosterone (DT) separately or together with cyproterone acetate (CA) (an antiandrogen) in BDF1 mice. Injection of 0.5 mg/100 g body weight of DT during 2 weeks decreased significantly the number and proportion of double positive (DP) (CD4+ CD8+) and increased the percentage of single positive (SP) CD4+ (CD4+ CD8-), whereas there was a slight decrease in the Thy 1.2+ cells in the thymus. In parallel, we observed an increase in CD8+ (CD4- CD8+) cells in the spleen. The androgen deprivation after 3 weeks of castration induced a decrease in the percentage of CD4+ cells in thymus and both CD4+ and CD8+ cells in spleen. Injection of CA (0.5 mg/100 g body weight) had the same qualitative effects as DT on the proportion of lymphocyte T subsets in castrated mice. However, the combined activities of DT and CA were greater than either alone. These data indicate the main role of testosterone in the distribution of CD4+ and CD8+ cells in male mice. The similar effects of CA and DT in the lymphoid organs may suggest a difference between androgen receptors of sexual and lymphoid organs.