Size and oxidative susceptibility of low-density lipoprotein particles in breast cancer patients with tamoxifen-induced fatty liver

The effect of oxidized low-density lipoprotein combined with adriamycin on the proliferation of Eca-109 cell line

Background

The purpose of this study was to identify the affect on the proliferation Eca-109 cells treated with oxidized low-density lipoprotein (ox-LDL) combined with adriamycin (ADM).

Methods

Eca-109 cell were cultured in the presence of oxLDL/ADM, and cell proliferation tested by MTT and cell apoptosis was monitored by the proportion of apoptosis and cell cycle by flow cytomester. We simultaneously evaluated the level of associated- apoptosis Bcl-2, Bax, and Caspase-3 gene mRNA and protein.

Results

OxLDL were cytotoxic and activate apoptosis. OxLDL combined with ADM significant enhanced the proportion rate of apoptosis on a time and dose dependency. The expressions of the inhibiting apoptosis Bcl-2 gene mRNA and protein were down regulated, whereas, the expressions of the promoting apoptosis Bax, and Caspase-3 genes mRNA and protein were up regulation.

Conclusion

These results suggested that oxLDL have cytotoxicity and activate apoptosis on the Eca-109 cells. OxLDL combined with ADM have a synergistic effect on the apoptosis induced Eca-109 cells. Furthermore, oxLDL may contribute to the improvement of clinical chemotherapy of cancer need to make further investigation.

Assessment of vascular effects of tamoxifen and its metabolites on the rat perfused hindquarter vascular bed

Tamoxifen has been suggested to produce beneficial cardiovascular effects, although the mechanisms for these effects are not fully known. Moreover, although tamoxifen metabolites may exhibit 30-100 times higher potency than the parent drug, no previous study has compared the effects produced by tamoxifen and its metabolites on vascular function. Here, we assessed the vascular responses to acetylcholine and sodium nitroprusside on perfused hindquarter vascular bed of rats treated with tamoxifen or its main metabolites (N-desmethyl-tamoxifen, 4-hydroxy-tamoxifen, and endoxifen) for 2 weeks. Plasma and whole-blood thiobarbituric acid reactive substances (TBARS) concentrations were determined using a fluorometric method. Plasma nitrite and NOx (nitrite + nitrate) concentrations were determined using an ozone-based chemiluminescence assay and Griess reaction, respectively. Treatment with tamoxifen reduced the responses to acetylcholine (pD(2) = 2.2 +/- 0.06 and 1.9 +/- 0.05 after vehicle and tamoxifen, respectively; P < 0.05), while its metabolites improved these responses (pD(2) = 2.5 +/- 0.04 after N-desmethyl-tamoxifen, 2.5 +/- 0.03 after 4-hydroxy-tamoxifen, and 2.6 +/- 0.08 after endoxifen; P < 0.01). Tamoxifen and its metabolites showed no effect on endothelial-independent responses to sodium nitroprusside (P > 0.05). While tamoxifen treatment resulted in significantly higher plasma and whole blood lipid peroxide levels (37% and 62%, respectively; both P < 0.05), its metabolites significantly decreased lipid peroxide levels (by approximately 50%; P < 0.05). While treatment with tamoxifen decreased the concentrations of markers of nitric oxide formation by approximately 50% (P < 0.05), tamoxifen metabolites had no effect on these parameters (P > 0.05). These results suggest that while tamoxifen produces detrimental effects, its metabolites produce counteracting beneficial effects on the vascular system and on nitric oxide/reactive oxygen species formation.