Efficacy of estriol in inhibiting epithelial proliferation in mammary fibroadenoma: randomized clinical trial

CONTEXT AND OBJECTIVE: Mammary fibroadenoma is a disease that affects a large number of women of reproductive age. The aim of this study was to evaluate the proliferative activity of mammary fibroadenoma through expression of Ki-67 and c-myc antigens, following administration of oral contraceptive with or without estriol. DESIGN AND SETTING: Placebo-controlled double-blind randomized clinical trial in the Mastology Sector of the Department of Gynecology, Universidade Federal de São Paulo. METHODS: Thirty-three fibroadenoma patients were studied. Ten women (group 1) took an oral contraceptive constituted by levonorgestrel and ethinyl estradiol together with placebo manufactured in the same capsule for four consecutive cycles with a seven-day interval between them. The other 23 patients (group 2) took the same oral contraceptive together with estriol, which was put into the same capsule and used in the same way as among the group 1 patients. After four cycles, the nodules were surgically removed and sent for immunohistochemical analysis of Ki-67 and c-myc expression. RESULTS: The Ki-67 and c-myc analysis did not reveal any significant differences between the study groups. The values were 9.16 and 10.54 for group 1 and 10.86 and 17.03 for group 2, respectively. There was a tendency towards higher expression of antigens in group 2. CONCLUSION: Our results showed that there was no significant statistical difference in Ki-67 and c-myc expression between our study groups, but only a tendency towards higher expression among users of oral contraceptives containing estriol.

CONTEXTO E OBJETIVO: O fibroadenoma mamário é uma doença que atinge um grande número de mulheres na idade reprodutiva. O objetivo foi avaliar a atividade proliferativa do fibroadenoma mamário, através da expressão do Ki-67 e do c-myc, após a administração de anticoncepcional oral, associado ou não ao estriol. TIPO DE ESTUDO E LOCAL: Ensaio clínico randomizado, duplo-cego, placebo controlado, realizado na Universidade Federal de São Paulo a nível terciário. MÉTODOS: Foram estudadas 33 pacientes portadoras de fibroadenoma, atendidas no setor de Mastologia da Disciplina de Ginecologia da Universidade Federal de São Paulo - Escola Paulista de Medicina (Unifesp-EPM), sendo que 10 mulheres constituíram o grupo 1, e utilizaram anticoncepcional oral composto de levonorgestrel e etinilestradiol, associados a placebo na mesma cápsula por quatro ciclos consecutivos, com intervalo de sete dias entre cada um. As restantes 23 pacientes alocaram-se no grupo 2 e ingeriram, além do anticoncepcional oral descrito acima, um comprimido de estriol, que foi manufaturado na mesma cápsula e foi utilizado da mesma forma que nas pacientes do grupo 1. Ao final dos quatro ciclos, praticou-se a exérese cirúrgica dos nódulos, com posterior envio para análise imunoistoquímica de Ki-67 e c-myc. RESULTADOS: A análise com Ki-67 e c-myc não revelou diferença significante entre os grupos estudados, que foi de 9,16 e 10,54 no grupo 1 e de 10,86 e 17,03 no grupo 2, respectivamente, apesar de ter havido tendência a maior expressão dos marcadores entre as pacientes do grupo 2. CONCLUSÃO: Nossos resultados demonstram não haver diferença estatisticamente significante na expressão de Ki-67 e de c-myc entre os grupos em estudo, apenas uma tendência a sua maior expressão entre as usuárias de anticoncepcional e estriol.

Effect on Cell Growth, c-myc mRNA Expression and Telomerase Activity by Transforming Growth Factor-beta1 in Malignant Lymphoma and Leukemia Cell Line

BACKGROUND: Transforming growth factor-beta1 (TGF-beta1) is known to be a potent growth inhibitor of many cell types, including most epithelial cells. However, the mechanism of TGF-beta1 action on cell growth in lymphomas and leukemia still remains to be elucidated. c-myc is a central regulator of cell proliferation and apoptosis, and telomerase is believed to play an important role in carcinogenesis. The aim of the study was to determine the effects of cell growth, c-myc gene expression and telomerase activity due to TGF-beta1 and examine its mechanism of action in lymphomas and leukemia. METHODS: The cell growths of Jiyoye (Burkitt lymphoma), H9 (T cell lymphoma), and CCRF-CEM (acute lymphocytic leukemia, T cell) cell lines due to TGF-beta1 were measured using the MTT assay. RT-PCR was also performed to monitor the expression of the c-myc gene in these cells with the telomerase activity measured using a TRAP assay. RESULTS: There was significant inhibition of cell growth in TGF-beta1 (5ng/mL) treated Jiyoye cells. When treated with TGF-beta1, the Jiyoye cells exhibited marked decreases in the levels of c-myc RNA and telomerase activity. However, TGF-beta1 treated H9 and CCRF-CEM cells showed no cell growth inhibition or reductions in the levels of c-myc mRNA and telomerase activity. The effect of TGF-beta1 on cell growth was noted to closely correlate with c-myc mRNA expression and telomerase activity. CONCLUSION: These results suggest that TGF-beta1 may inhibit cell growth in Jiyoye cells by a mechanism involving down-regulation of the c-myc gene, which in turn, reduces the telomerase activity.