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| Author(s): |
Tialfi Bergamin de Castro
Total Authors: 1
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| Document type: | Doctoral Thesis |
| Press: | São José do Rio Preto. 2017-12-04. |
| Institution: | Universidade Estadual Paulista (Unesp). Instituto de Biociências Letras e Ciências Exatas. São José do Rio Preto |
| Defense date: | 2017-10-31 |
| Advisor: | Debora Aparecida Pires de Campos Zuccari; Eduardo Alves Almeida |
| Abstract | |
Breast cancer is the Jeading cause of cancer-related deaths in women and researches has been focused on identify and validate biomarkers that can be used to confirm the diagnosis and determine the prognosis. Changes in circadian rhythm may contribute to the development of cancer and thus melatonin, a hormone synthesized by the pineal gland at night, in the absence of light and its metabolites AFMK and AMK are suggested as potential biomarkers. Melatonin can act through the MT1 receptor by regulating kinases and the expression of specific genes related to proliferation, angiogenesis, ce/1 differentiation and glucose transport. High GLUT1 (Glucose Transporter-1) expression is associated with poor prognosis in cancer. The objectives of this study were to compare the leveis of melatonin, AFMK and AMK in women newly diagnosed with breast cancer, women on adjuvant chemotherapy, health nurses which work at night compared to healthy women and normal habits and the expression of MT1 receptor and GLUT1 in breast tumors and correlated with molecular subtypes, pathological features and prognosis. Blood from 53 women with breast cancer was colletcted, 47 of them without treatment and 6 in adjuvant chemotherapy, 19 healthy women, 1 O of them night shift nurses and 9 women of normal habits. Compounds were quantified by mass spectrometry. For the expression of MT1 and GLUT1, immunohistochemistry was performed in 42 breast tumors. The results showed that women with breast cancer had lower leveis of melatonin compared to normal women (p <0.01), even Jower leveis in nurses working at night and in adjuvant chemotherapy (p <0.01). There was no significant difference in AFMK and AMK leveis between groups (p> 0.05). ln addition, patients with metastasis had high leveis of melatonin and AFMK (p = 0.02 and p = 0.01, respectively) and high leveis of AFMK were present when lymph nades were affected (p = 0.04), patients with tumors larger than 20mm and who sleep with light at night (p = 0.02 and p = 0.007, respectively). ln the immunohistochemical analysis, high MT1 expression was associated with the Luminal A subtype, with a better prognosis (p <O.OS) and in ER + tumors (p = 0.002), whereas high GLUT1 expression was associated with tripie negative, worse prognosis (p<0.05), tumors greaterthan 20mm (p= 0.004) and low in ER + tumors (p = 0.003). ln conclusion, our results show Jower leveis of melatonin in breast cancer patients and point to the benefit of melatonin supplementation as protection for women who work at night which could reduce the risk of developing breast cancer. The results of immunohistochemistry indicate that MT1 and GLUT1 can be used as prognostic markers and are potential targets for the treatment of breast cancer. According to the results it can be concluded that the breakdown of the circadian cyc/e and, therefore, changes in melatonin leveis and the expression of MT1 and GLUT1 may be related to the risk of development and prognosis of breast cancer (AU) | |
| FAPESP's process: | 15/02935-2 - Melatonin and its metabolites as prognostic markers in human breast neoplasms |
| Grantee: | Tialfi Bergamin de Castro |
| Support Opportunities: | Scholarships in Brazil - Doctorate |