The influence of phenothiazine derivatives on doxorubicin treatment in sensitive and resistant human breast adenocarcinoma cells.

Breast cancer is commonly treated by various combinations of surgery, radiation therapy, chemotherapy and hormone therapy. Most cancers either are increasingly resistant to any initial treatment or acquire resistance to a broad spectrum of anticancer drugs over time. Combination of more than one drug or combination with multidrug resistance (MDR) modifiers will possibly support the efficiency of the applied therapy. Understanding the MDR mechanisms in malignancies is crucial for developing novel strategies for treatment. The main goal of our study was to determine the cytostatic effect of doxorubicin in combination with phenothiazine derivatives (PD; promazine and triflupromazine) in doxorubicin-sensitive (MCF-7/WT) and -resistant (MCF-7/DOX) human breast adenocarcinoma cell lines. We determined cytotoxicity of the investigated compounds (MTT assay) after 24 and 48 h. The effect of phenothiazine derivatives was evaluated and doxorubicin localization was performed using confocal microscopy. The mode of the cell death was examined by the comet assay. We also determined the expression of P-glycoprotein (P-gp), which is a membrane-associated protein responsible for the multidrug resistance.

Comparison of techniques permitting to detect apoptosis in situ.

Several morphological and biochemical techniques are in use for identification of apoptotic and necrotic cells in a studied cell population. It is essential to define not only the type of cell death but also to identify the apoptotic process itself, which represents a multistage, active process, requiring activation of a molecular event cascade. In the present study, we have examined and discussed effectiveness of the selected techniques detecting apoptosis in lymphocytes exposed to incubation at an elevated temperature. The appraisal involved detection of caspase-3 active form, detection of Bcl-2, TUNEL reaction, the comet assay and electrophoresis of DNA.

Intensity of apoptosis as related to the expression of metallothionein (MT), caspase-3 (cas-3) and Ki-67 antigen and the survival time of patients with primary colorectal adenocarcinomas.

The present study aimed at analysing the intensity of apoptosis, as related to the expression of pro- and anti-apoptotic cellular markers (cas-3, MT, Ki-67 antigen), and at evaluating their expression in relation to the survival time of patients with colorectal adenocarcinoma. Material for the studies was obtained from 40 patients with primary colorectal adenocarcinomas (G2, T3N0M0), treated at the Lower Silesia Centre of Oncology in Wroclaw. Tumour samples were fixed in 4% buffered formalin and embedded in paraffin blocks. In obtained paraffin sections, TUNEL reaction (detection of apoptosis) and immunocytochemical reactions were performed (detection of cas-3, MT and Ki-67 antigen expression). The results disclosed a weak correlation between the intensity of apoptosis and the expression of MT, cas-3 and Ki-67 antigen (r = 0.18; r = 0.33; r = 0.15, respectively) in cells of colorectal adenocarcinomas. The survival time of the patients was shorter, when the apoptosis and expression of Ki-67 antigen were highly pronounced. The time periods of the patients' survival showed no correlation with the expression of cas-3 or MT. The obtained results point to the key role of apoptosis and proliferation processes in the clinical course of colorectal adenocarcinomas.