Methods: An in vitro cell model for tamoxifen-resistant HER2 overexpressed UACC732 cells was created using the pulse method. Cells were exposed to oxidized LDL (oxLDL) and very low density lipoprotein (VLDL) separately. Effects on cell morphology was studied using phase contrast microscopic changes. Percentage of cell viability was measured using proliferation assay kit. Development of tamoxifen resistance was determined based on P-gp expression with flow cytometry. Further analysis includedcell death measurement with flow cytometry method.
Results: UACC732 cells exposed to VLDL exhibited fibroblast-like morphology. This was further supported by proliferation assay, where the percentage of cell viability achieved more than 100% with 100 μg/ml of VLDL exposure, indicating cell proliferation. Findings also showed that VLDL caused reduction in expression of Pgp in resistant cells compared to resistant cells alone (p = 0.02).
Conclusion: Results of this study suggest that VLDL may play a role in growth of drug-resistant HER2-overexpressing cells. Lower expression of P-gp in presence of VLDL need to be investigated further.
MATERIALS & METHODS: This is a case-control study consisting of 47 MDD patients and 47 healthy controls. MDD patients were treated with antidepressant drugs according to their physician's choice. The severity of MDD was assessed using Beck Depression Inventory (BDI) and Montgomery-Asberg Depression Rating Scale (MADRS) at the time of recruitment. Healthy controls completed the Depression Anxiety Scoring System (DASS21) questionnaire to ensure they were in good mental health without history of MDD. The percentage and absolute count of CD4+ CD25+ Tregs and CD4+ CD25+ FOXP3+ Tregs were identified by multiparameter flow cytometry.
RESULTS: The percentage and absolute count of CD4+ CD25+ Treg cells were significantly higher in MDD patients than in healthy controls (P<0.001, in both cases). Likewise, the percentage and absolute count of CD4+ CD25+ FOXP3+ Treg cells were also significantly higher in MDD patients compared to healthy controls (P=0.003 and P=0.002, respectively). However, there was no significant correlation between the percentage and absolute count of CD4+ CD25+ Treg and CD4+ CD25+ FOXP3+ Treg cells with BDI or MADRS score.
CONCLUSIONS: Our results suggest that antidepressant treatments contributed to an upregulation of Tregs in MDD patients.