Background. A role of an estrogen-regulated, autocrine motogenic factor was assumed to be a major biological role of trefoil factor 1 (TFF1) in breast cancer. TFF1 is regarded as a predictive factor for positive response to endocrine therapy in breast cancer patients. The aim of our study was to examine TFF1 level distribution in breast carcinomas in order to distinguish estrogen-independent from estrogen-dependent TFF1 expression and to evaluate clinical usefulness of TFF1 status in early breast cancer during the first 3 years of follow-up.

Aim: The aim of this study was to evaluate clinical usefulness of cathepsin D status in early breast cancer during the first 3 years of follow-up. Patients & methods: The study included 226 patients with histologically verified, primary operable invasive early breast carcinomas. Concentrations of estrogen receptor (ER) and progesterone receptor (PR) in breast tumor cytosols were measured by use of the classical biochemical method. The concentration of three cathepsin D forms (52-, 48- and 34-kDa proteins) was determined by a radioimmunoassay Results: On the basis of differences in cathepsin D levels either within an ER-/PR- phenotype or between this and either ER+/PR+ or ER+/PR- phenotypes, a concentration of 39 pmol/mg was determined as the cutoff value for distinguishing estrogen-regulated cathepsin D expression. Estrogen-regulated cathepsin D expression was recognized as a high-risk biomarker for low-risk (histological grade I) breast cancer patients and as a low-risk biomarker for high-risk patients (pN(+) pT2,3). Conclusion: Determination of cathepsin D status in breast cancer might identify patients at different risk for relapse and might facilitate the selection of more or less aggressive adjuvant therapy for early breast cancer patients during the first 3 years of follow-up.

Herein, a screen–printed diamond electrode (SPDE) coupled with a “point-of-care” platform (30 µL-drop concepts, single-drop-detection approach) was successfully applied for the electrochemical determination of pterostilbene (PTS). Cyclic voltammetry identified irreversible oxidation of PTS, where oxidation peak was shown to be strongly dependent on the pH of the working environmental. Although the proposition of the detailed electrochemical oxidation mechanism of PTS goes out of the scope of the present research, we have determined the most probable reactive site of our analyte, by utilizing DFT-based reactivity descriptors (Fukui functions). For electrochemical quantification of PTS, oxidation peak at 0.32 V (vs. Ag/AgCl) was followed in presence of 0.5 mol L⁻¹ of Briton–Robinson buffer solution (pH = 9). Coupled with the optimized parameters of differential pulse voltammetry (DPV), SPDE detected PTS in two linear ranges (first range was from 0.011 to 0.912 µmol L⁻¹; second range was from 0.912 to 4.420 µmol L⁻¹), providing the LOD and LOQ on a nanomolar level (3.1 nmol L⁻¹ and 10.0 nmol L⁻¹, respectively). The selectivity of the optimized DPV method was found to be excellent, with the current changes of less than 7%, in the presence of ten times higher concentrations of the certain interferences. The practical applicability of the SPDE and single-drop-detection approach in dietary supplements (with a declared PTS content of 50 mg/tablet), with the recovery values ranging from 95 to 102%, shows that the developed method has high potential for precise and accurate PTS detection, as well as exceptional miniaturization possibilities of relevant equipment for on-site sensing.

To better understand the mechanism of action of the compounds in the ethanolic extracts of J. nigra leaves and green husks, their binding to CT-DNA was investigated. This study was conducted to elucidate the in vitro protective effect of extracts against chromosomal damage in mitogen-induced human lymphocytes and investigate the possible application of selec+ted extracts as a natural source of polyphenolic compounds. Using HPLC-MS analysis, 103 different compounds were identified as having a higher number of active species, which is consistent with their activity. The frequency of micronuclei (MN) was scored in binucleated cells, and the nuclear proliferation index was calculated. Cyclic voltammetry experiments demonstrate that the nature of the interaction between extracts and CT-DNA is a synergy of electrostatic and intercalative modes, where leaves extracts showed a higher ability to bind to DNA. Extracts showed excellent antioxidant activity. At a concentration of only 4 µg/mL, extract of J. nigra leaves and the green husks reduced the incidence of MN by 58.2% and 64.5%, respectively, compared to control cell cultures.

In addition to classical prognostic/predictive factors, significant biological markers have been identified to provide potentially relevant information regarding natural or clinical course of breast cancer. Steroid receptor status of the primary breast cancer have been proven to be a predictor of response to endocrine therapy since up to 80 % of patients with steroid receptor-positive tumors respond to endocrine treatment. In order to improve the predictive value of steroid receptor status, attention has been paid to estrogen-regulated proteins, including pS2 and cathepsin D among others that may be indicators of a functional signal transduction pathway through which tumor cells respond to estrogen stimulation. It has been shown that pS2 protein may be constitutive product as well as estrogen-regulated product in breast carcinoma. pS2 appears to be positively correlated with ER, associated with a good prognosis and a predictor of response to endocrine treatment of primary and metastatic breast cancer. The expression cathepsin D may be both constitutive and overexpressed as a result of estrogen-induced transcription. It was believed that the main role of cathepsin D was to degrade protein, but many other biological functions of cathepsin D were recognized. Cathepsin D level in primary breast cancer has been demonstrated as an independent marker of poor prognosis associated with increased risk for metastasis and shorter survival times. Our recent results show direct correlation of cathepsin D positivity with pS2 expression. Additionally, we found that cathepsin D is statistically significantly associated with pS2 both in node-negative and node-positive patients bearing tumors smaller than 2 cm. .