Expression of Nrf2 and NF-κB transcription factors in breast cancer and breast fibroadenoma: Insights for a new therapeutic approach.

Background: Cancer and fibroadenoma are the most common breast tumors in women of reproductive age. Nuclear factor erythroid 2-related factor 2 (Nrf2) and the nuclear factor kappaB (NF-κB) transcription factor play an important role in the inflammatory process and in cell proliferation. However, few studies have analyzed these markers in breast cancer and fibroadenoma in women of reproductive age. Results: Light microscopy showed a higher concentration of anti-Nrf2 and anti-NF-κB-stained nuclei in breast cancer than in fibroadenoma. The mean percentage of stained nuclei for Nrf2 was 7.12 ± 5.2 and 43.21 ± 19.83 in the control and study groups, respectively (p < 0.0001). The mean percentage of anti-NF-κB was 10.75 ± 7.09 and 56.14 ± 21.19 (mean ± standard deviation) in the control and study groups, respectively (p < 0.0001). Histological grade 3 tumors showed a significantly higher expression of Nrf2 and NF-κB than grade 1 tumors (p < 0.05). Material and methods: This study was approved by the Institutional Review Board of Federal University of Piaui and all patients assigned an inform consent term prior to the study initiation. Nrf2 and NF-κB expression was evaluated by immunohistochemistry in 66 patients, divided into two groups, control (fibroadenoma, n = 36) and study (cancer, n = 30). The data were analyzed using ANOVA test and the statistical significance was established at p < 0.05. Conclusion: Nrf2 and NF-κB expression was significantly higher in breast cancer than in fibroadenoma, in addition to having a greater association with more aggressive tumors.

Bcl-2 antigen expression in luminal A and triple-negative breast cancer.

Biomarkers for the prognosis of breast cancer have been routinely used in clinical practice, including the expression of hormone receptors, Ki-67 and HER-2. More recently, Bcl-2 has been recognized as an important prognostic factor in breast cancer, although controversies persist with respect to the significance of its expression. The aim of the present study was to evaluate Bcl-2 antigen expression in luminal A and triple-negative breast cancer. Sixty women with invasive ductal carcinoma were included in the study and divided into two groups: Group A (luminal A) and Group B (triple-negative), with 30 cases in each group. Immunohistochemistry was performed on tissue sections to evaluate Bcl-2 antigen expression. Fisher's exact test was used to compare the proportions of cases with cells expressing Bcl-2 between the two subtype cancer groups, with statistical significance being established at p < 0.05. The number of cases with cells expressing Bcl-2 in Groups A and B was 26 (86.7%) and 12 (40.0%), respectively (p < 0.0003). In the present study, the expression of the anti-apoptotic protein Bcl-2 was greater in luminal A breast cancer tissue samples compared to triple-negative breast cancer.

RELATIONSHIP BETWEEN ZINCEMIA, SUPEROXIDE DISMUTASE ACTIVITY AND MARKER OF OXIDATIVE STRESS IN WOMEN WITH BREAST CANCER.

INTRODUCTION: studies show changes in zinc metabolism in women with breast cancer. This mineral has antioxidant action, and disorders in its biochemical parameters are related to poor prognosis of the disease and increase in the carcinogenic process. OBJECTIVE: this study evaluated the activity of enzyme superoxide dismutase and biochemical parameters related to zinc, and investigated the existence of correlation between these variables and the marker of oxidative stress in these patients. METHODS: this was a case-control study with 66 women aged between 20 and 50 years old, distributed into: case group (women with breast cancer, n = 34) and control group (healthy women, n = 32). Zinc intake was analyzed by three-day food diary, using Nutwin software, version 1.5. Plasma and erythrocyte zinc concentrations were determined by flame atomic absorption spectrophotometry method (λ = 213.9). Superoxide dismutase activity was assessed by Griess colorimetric method, and plasma thiobarbituric acid reactive substances (TBARS) were analyzed. RESULTS AND DISCUSSION: mean levels of zinc intake, superoxide dismutase and TBARS were higher than recommended for the study participants with statistical difference for enzyme superoxide dismutase (p < 0.05). Mean plasma and erythrocyte concentrations of zinc were reduced in both groups (p > 0.05). CONCLUSIONS: therefore, it can be assumed that zinc intake in women with breast cancer does not impact plasma and erythrocyte concentrations of this mineral. High superoxide dismutase activity in women with breast cancer may be due to a compensatory mechanism of regulation via oxidative stress found in this disease.

Introducción: diversos estudios muestran alteraciones en el metabolismo del zinc en mujeres con cáncer de mama. Este mineral posee acción antioxidante, y los disturbios en sus parámetros bioquímicos están relacionados con peor pronóstico de la enfermedad y agravamiento del proceso carcinogénico. Objetivos: este estudio evaluó la actividad de la enzima superóxido dismutasa y los parámetros bioquímicos relativos al zinc e investigó la existencia de correlación entre esas variables y el marcador del estrés oxidativo en estas pacientes. Métodos: este fue un estudio caso-control con 66 mujeres, con edad ente 20 y 50 años, distribuidas en: grupo caso (mujeres con cáncer de mama, n = 34) y grupo control (mujeres saludables, n = 32). La ingestión del zinc fue realizada por medio del registro alimentario de tres días, utilizando el programa Nutwin versión 1.5. Las concentraciones de zinc plasmático y eritrocitario fueron determinadas según el método de espectrofotometría de absorción atómica de llama (λ = 213,9). La actividad de la superóxido dismutasa fue evaluada por el método colorimétrico de Griess y fueron analizadas sustancias reactivas al ácido tiobarbitúrico (TBARS). Resultados y discusión: los valores medios de la ingestión de zinc, superóxido dismutasa y TARBS eran superiores a los recomendados para las participantes del estudio, con una diferencia estadística para la enzima superóxido dismutasa (p > 0,05). La media de las concentraciones plasmática y eritrocitaria de zinc fueron reducidos en ambos grupos (p > 0.05). Conclusiones: por lo tanto, se puede suponer que la ingesta de zinc en mujeres con cáncer de mama no influye en las concentraciones plasmáticas y eritrocitarias de ese mineral. La elevada actividad de la superóxido dismutasa en las mujeres con cáncer de mama puede ser debida a un mecanismo de regulación compensatorio mediante el estrés oxidativo presente en esa enfermedad.