Immunohistochemical Expression of Melatonin Receptor MT1 and Glucose Transporter GLUT1 in Human Breast Cancer

Background:

Breast cancer is a heterogeneous disease and is the leading cause of cancer-related deaths among women. Even after diagnosis, the prognosis cannot be concluded since patients can develop resistance to therapy, which favors tumor growth, invasion and metastasis. In recent years, research has focused on identifying significant markers that can be used to determine the prognosis. Melatonin can act through G protein– coupled MT1 receptor, which controls selected protein kinases, influences the levels of transcription factor phosphorylation, specific genes expression, proliferation, angiogenesis, cell differentiation, migration, and indirectly controls the transport of glucose in cancer cells. It is known that glucose enters the cells by glucose transporters, such as GLUT1 which shows wide tissue distribution and appears to be altered in human breast carcinoma. High GLUT1 expression is associated with increased malignant potential, invasiveness and poor prognosis in some cancers including breast cancer.

Objective:

The aim of this study was to evaluate the expression of MT1 receptor and GLUT1 in breast tumors and correlate with molecular subtypes and prognostic characteristics.

Method:

Protein expression was performed by an immunohistochemical procedure with specific antibodies and positive and negative controls.

Results:

We found that MT1 high expression was associated with good prognosis subtype (Luminal A), while GLUT1 high expression was related to poor prognosis subtype (triple-negative). In addition, we found high expression of MT1 in ER+ and the inverse in GLUT1 expression. GLUT1 is also highly expressed in tumor ≥20mm.

Conclusion:

These results indicate MT1 and GLUT1 as potential targets for breast cancer subtypes and prognosis.

Desenvolvimento e Avaliação de um Novo Adesivo Odontológico para Remineralização Biomimética de Interfaces Adesivas

O objetivo foi avaliar os efeitos de adesivos autocondicionantes experimentais (AAE) com partículas bioativas e com um novo análogo biomimético EDTF (etilenodiamino tetrametileno-fosfonato) na degradação da interface e remineralização de dentina hígida e afetada por cárie. Os AAEs foram preparados com mistura prévia com fosfato de cálcio mono-hidratado e þ-TCP no bond, e primers contendo os análogos biomiméticos divididos em 6 grupos: sistema sem análogos e sem partículas (controle negativo, CN), primer com trimetafosfato (TMP) e ácido poliacrílico (APA) (controle positivo, CP), EDTF/TMP, EDTF/APA, EDTF sozinho e grupo com fosfatos no bond e sem análogos no primer. Eles foram aplicados em dentina afetada por cárie (DAC) e em dentina hígida de molares humanos extraídos. Após períodos de 24h/6 meses de armazenamento em água, foram avaliados por teste de microtração (µTBS), nanoinfiltração e espectroscopia Micro-Raman (EMR). Os dados foram analisados por ANOVA dois fatores e Teste de Tukey (a5%). Houve aumento (p<0,05) na µTBS em dentina hígida após 6 meses com EDTF/TMP e declínio com EDTF/ APA. Em DAC, houve queda nos grupos CN, EDTF/TMP e EDTF/APA (p<0,05). A nanoinfiltração em DAC de CN e EDTF/APA revelou fendas, degradação de dentina e adesivo. Na EMR observou-se mineralização nos grupos CP, EDTF, EDTF/TMP e somente partículas, sem mineralização em CN e EDTF/APA. Conclui-se que adesão e remineralização da dentina foram obtidas com o uso dos análogos tradicionais (TMP/APA) ou com EDTF sozinho, demonstrando sua efetividade como novo análogo biomimético.Palavras-chave: Materiais Biomiméticos. Sistemas Adesivos. Fosfatos de Cálcio.

Abstract 2408: Melatonin action in xenograft model of breast cancer, comparing radiopharmaceuticals in the detection of intratumor heterogeneity by PET/CT confirmed by immunohistochemical markers

Breast cancer is the most common cancer among women and has a high mortality rate. The rapid tumor growth makes difficult the perfusion of O2 mainly in the tumor center, and this hypoxia in tumor microenvironment can exerts selective pressure on the tumor cells, selecting subpopulations with advantage for survival in adverse conditions, characterizing the intratumor heterogeneity. In this context, melatonin, a hormone naturally produced by the pineal gland, has shown antitumor activity, as immunomodulatory, antioxidant, pro-apoptotic, anti-proliferative, antimetastatic, antiangiogenic and with potencial effects in intratumor heterogeneity. The aims of this study was to evaluate the effectiveness of melatonin in a xenograft model of breast cancer, focusing on intratumor heterogeneity verified by PET/CT and by immunohistochemical markers of hypoxia. The tumors were developed by the implantation of 5 million triple-negative breast cancer cells (MDA-MB-231) into the flank of female Balb/c nude mice (n = 14). Treatment with melatonin (n = 7) or vehicle (n = 7) was initiated 10 days after tumor implantation and continued for 14 days. At the end, micro-PET/CT scanning was performed with 18F-FDG, which is an analogue of glucose, and with 18F-FAZA, a specific radiopharmaceutical for hypoxia detection. The radiopharmaceuticals were injected by retro-orbital via and the images were acquired using Albira PET/SPECT/CT Carestream Molecular Imaging. Then, markers of hypoxia were evaluated by immunohistochemistry in mammary tumors. The results showed that tumor growth in animals treated with melatonin was lower than those treated with vehicle (p&lt;0.05). There was tumor regression in one animal treated with melatonin, showing 18.72 mm3 at start of treatment and no longer being detected after seven days of treatment. 18F-FDG can be used as hypoxia marker, however, studies show that can occurs overlapping areas of aerobic and anaerobic glycolysis in the tumor, difficulting the identification of hypoxic areas. 18F-FAZA has a hypoxia-specific uptake mechanism and a better spread by the tumor. Results of PET/CT showed that 18F-FDG had homogeneous uptake in breast tumors. In some tumors with high volume, there was no uptake in the tumor center, corresponding to areas of necrosis. In addition, there was an intratumor 18F-FAZA uptake heterogeneity, indicating possible hypoxic areas. Also, PET/CT results showed that there was less hypoxic areas in animals treated with melatonin, which was confirmed by immunohistochemical markers. Taken together, our results showed an important action of melatonin, in control of mammary tumor growth, decreasing hypoxia areas and controlling cancer progression. Financial support: Fundação de Amparo à Pesquisa do Estado de São Paulo

Citation Format: André L. Mota, Bruna V. Jardim-Perassi, Thaiz F. Borin, Nathália M. Sonehara, Lorena Pozzo, Emerson S. Bernardes, Bruno Cogliati, Debora APC Zuccari. Melatonin action in xenograft model of breast cancer, comparing radiopharmaceuticals in the detection of intratumor heterogeneity by PET/CT confirmed by immunohistochemical markers. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 2408.

Time course of the hemodynamic responses to aortic depressor nerve stimulation in conscious spontaneously hypertensive rats

The time to reach the maximum response of arterial pressure, heart rate and vascular resistance (hindquarter and mesenteric) was measured in conscious male spontaneously hypertensive (SHR) and normotensive control rats (NCR; Wistar; 18-22 weeks) subjected to electrical stimulation of the aortic depressor nerve (ADN). The parameters of stimulation were 1 mA intensity and 2 ms pulse length applied for 5 s, using frequencies of 10, 30, and 90 Hz. The time to reach the hemodynamic responses at different frequencies of ADN stimulation was similar for SHR (N = 15) and NCR (N = 14); hypotension = NCR (4194 ± 336 to 3695 ± 463 ms) vs SHR (3475 ± 354 to 4494 ± 300 ms); bradycardia = NCR (1618 ± 152 to 1358 ± 185 ms) vs SHR (1911 ± 323 to 1852 ± 431 ms), and the fall in hindquarter vascular resistance = NCR (6054 ± 486 to 6550 ± 847 ms) vs SHR (4849 ± 918 to 4926 ± 646 ms); mesenteric = NCR (5574 ± 790 to 5752 ± 539 ms) vs SHR (5638 ± 648 to 6777 ± 624 ms). In addition, ADN stimulation produced baroreflex responses characterized by a faster cardiac effect followed by a vascular effect, which together contributed to the decrease in arterial pressure. Therefore, the results indicate that there is no alteration in the conduction of the electrical impulse after the site of baroreceptor mechanical transduction in the baroreflex pathway (central and/or efferent) in conscious SHR compared to NCR.

Endothelin-1 contributes to the sexual differences in renal damage in DOCA-salt rats

We investigated whether gender differences in renal damage in DOCA-salt hypertension are associated with effects of ovarian hormones and/or endothelin-1 (ET-1). Renal injuries and renal pre-pro-ET-1 mRNA expression were enhanced in male and female ovariectomized (OVX) DOCA rats versus female DOCA rats. Treatment with estrogen plus progesterone or progesterone, but not estrogen alone, attenuated renal damage and pre-pro-ET-1 mRNA expression in OVX DOCA rats. The ETA antagonist BMS182874 greatly ameliorated renal damage in male and OVX DOCA rats. In conclusion, the ovarian hormones have a protective role on the renal structural alterations in female DOCA rats by modulating effects of ET-1, via ETA receptors.

Field theoretical approach to electrochemical deposition

In this work we present an application of the lambdaphi(4) field theoretical model to the adsorption of atoms and molecules on metallic surfaces-the electrochemical deposition. The usual approach to this system consists in the computational simulation using Monte Carlo techniques of an effective lattice-gas Hamiltonian. We construct an effective model towards a comparison between the lattice-gas Hamiltonian and the discrete version of the lambdaphi(4) Hamiltonian, obtaining the relationships between the model parameters and electrochemical quantities. The lambdaphi(4) model is studied in the mean field approximation, and the results are fitted and compared to numerical simulated and experimental data.

Light and electron microscopic analysis of controlled injury to follicular unit grafts

BACKGROUND

Careful manipulation of hair units is essential for a good yield of transplanted hair.

OBJECTIVE

To analyze the morphology of dissected follicular units submitted to crushing, stretching, bending, and drying.

METHODS

Follicular units were either crushed, bent, stretched with forceps, or left drying on surgical gloves for 3 minutes. The specimens were fixed and prepared for observation with light microscopy or transmission and scanning electron microscopy.

RESULTS

No alterations were detected in follicular units that had been crushed, bent, or stretched. Major damage occurred in samples that were left to dry on gloves.

CONCLUSION

Letting the follicular unit dry appears to be the worst mishandling to which the follicular units may be subjected during routine hair transplantation.