Low expression of NQO1 predicts pathological complete response to neoadjuvant chemotherapy in breast cancer patients treated with TAC regimen.

The aim of this study was to evaluate preoperative tumour expression of NAD(P)H:quinone oxidoreductase 1 (NQO1) along with other biological markers as potential predictors of pathological complete response (pCR) to neoadjuvant docetaxel, doxorubicin, and cyclophosphamide-containing (TAC) chemotherapy in patients with primary breast cancer. Sixty-one patients who received neoadjuvant chemotherapy (NCT) with TAC regimen were enrolled in this prospective study. The pre- and post- NCT expression of oestrogen receptor (ER), progesterone receptor (PR), epidermal growth factor receptor 1 and 2 (EGFR and HER2), NQO1, Ki-67 proliferation index, multidrug resistance protein 1 (MDR1), p53 and BCL2 were evaluated by immunohistochemistry. The pCR was reached in 14 patients (23 % of the study group). Multivariate analysis demonstrated that patients with ER-, PR-, NQO1- negative, and Ki-67-positive tumours had a significantly higher chance to achieve pCR. Within the biological subtypes, the highest pCR rate (50 %) was seen in triple-negative (i.e. ER-, PR-, HER2-) tumours. Post-operative evaluation showed that in comparison to pre-operative tissue samples, NQO1 expression was significantly increased, while Ki-67 and HER2 decreased, in the residual tissue after NCT. In conclusion, the present data suggests that NQO1 expression may be a novel diagnostic biomarker for the prediction of positive response to NCT in patients with breast cancer.

Role of transplanted bone marrow cells in response to skeletal muscle injury.

The recently discovered capacity of bone marrow cells (BMCs) to contribute to injury-induced skeletal muscle regeneration has brought new possibilities in the treatment of skeletal muscle diseases. However, a suitable method of BMC transplantation usable for such therapy has to be established. In this work, recipient mice were intramuscularly injected with cardiotoxin, then whole-body lethally irradiated to eradicate satellite cells in their injured tibialis anterior (TA) muscles and to suppress haematopoiesis, and subsequently intravenously transplanted with lacZ+ BMCs with the aim to investigate the role of exogenous BMCs in response to skeletal muscle injury. Seven to 33 days after grafting, recipient TA muscles were examined to detect donor-derived X-gal+ cells and analysed by quantitative PCR. In injured recipients' muscles, X-gal positivity was identified 14 and 33 days after grafting in some infiltrating neutrophils and macrophages, infrequently in fibroblasts of endomysium, and in many large multinucleated cells (devoid of myogenic markers desmin and nestin) resembling foreign body giant cells situated in the vicinity of necrotic muscle fibres. qPCR confirmed the presence of transplanted lacZ+ BMCs in injured recipients' muscles. Our results proved the ability of intravenously transplanted adult BMCs to settle in injured muscles and generate blood cells that infiltrated endomysium and took part in the cleaning reaction. After inhibition of endogenous myogenesis, BMCs were not able to participate in formation of new muscle fibres due to persisting necrosis of degenerated muscle fibres. Instead, BMCs attempted to resorb necrotic structures, which confirmed the indispensable role of bone marrow-derived macrophages in skeletal muscle regeneration.

Endoglin co-expression with eNOS, SMAD2 and phosphorylated SMAD2/3 in normocholesterolemic and hypercholesterolemic mice: an immunohistochemical study.

Endoglin, a homodimeric transmembrane glycoprotein, is a part of the transforming growth factor-beta (TGF-beta) receptor cascade. It has been demonstrated that endoglin can affect TGF-beta signaling and eNOS expression by affecting SMAD proteins in vitro. We planned to go one step forward and evaluate whether endoglin is co-expressed with SMAD2, phosphorylated SMAD2/3 protein and eNOS in endothelium of normocholesterolemic C57BL/6J mice, and in advanced atherosclerotic lesions in hypercholesterolemic apoE/LDLr-deficient mice by means of fluorescence immunohistochemistry. Female C57BL/6J mice were fed with a chow diet (standard laboratory diet) for 12 weeks after weaning (at the age of 4 weeks). Two-month-old female apoE/LDLr-deficient mice were fed the western type diet (atherogenic diet) containing 21% fat (11% saturated fat) and 0.15% cholesterol for 2 months. Immunohistochemical analysis of endoglin, SMAD2, phosphorylated SMAD2/3 and eNOS expression was performed in mice aortic sinus. Immunohistochemical analysis showed the expression of endoglin in intact endothelium in both C57BL/6J and apoE/LDLr-deficient mice and in endothelium covering the atherosclerotic lesion in apoE/LDLr-deficient mice. Fluorescence immunohistochemistry revealed co-expression of endoglin with SMAD2, phosphorylated SMAD2/3 and eNOS in intact aortic endothelium in C57BL/6J mice. Moreover, strong co-localization of endoglin, SMAD2, phosphorylated SMAD2/3 and eNOS was also detected in endothelium covering atherosclerotic lesions in apoE/LDLr-deficient mice. In conclusion, we suggest that endoglin, SMAD2, phosphorylated SMAD2/3 and eNOS may be important in vessel endothelium homeostasis underlying their role in atherogenesis.

Diurnal variation of 6beta-hydroxycortisol in cardiac patients.

The 24-hour urinary excretion of 6-beta-hydroxycortisol (6beta-OHC) and the urinary ratio of 6beta- hydroxycortisol/cortisol (6beta-OHC/UFC) have been proposed as noninvasive probes for human cytochrome P450 3A4 isoform (CYP3A4). In this study, we evaluated within- and between-day variability of 6beta-OHC excretion and 6beta-OHC/UFC ratio in nine Caucasian men with cardiac disease. Each study participant was asked to collect 24-hour urine specimens during four consecutive days in five standardized time intervals. Concentrations of UFC and 6beta-OHC were determined by immunoassay and the high-performance liquid chromatographic (HPLC) method, respectively. The HPLC method was accurate and precise, as indicated by the recovery rate of 96.5-103.3 % and less than 5.2 % and 6.3 % of the coefficient of variation for within-run and between-run assay, respectively. In patients, diurnal variations in UFC and 6beta-OHC excretion were parallel. Consequently, 6beta-OHC/UFC ratio remained stable during the day. Both, 6beta-OHC excretion and 6beta-OHC/UFC ratio showed significant relationship between 24-hour value and values measured in corresponding collection periods with best correlations obtained from night interval (22.00-06.00, r = 0.86-0.91). These results indicated that urinary 6beta-OHC excretion and 6beta-OHC/UFC ratio measured in overnight/morning urine could precisely reflect 24-hour values even in severely ill patients. In addition, a simple and sensitive HPLC method was described for determination of 6beta-OHC in urine.