Amphiregulin Mediates Estrogen, Progesterone, and EGFR Signaling in the Normal Rat Mammary Gland and in Hormone-Dependent Rat Mammary Cancers

Both estrogen (E) and progesterone (P) are implicated in the etiology of human breast cancer. Defining their mechanisms of action, particularly in vivo, is relevant to the prevention and therapy of breast cancer. We investigated the molecular and cellular mechanisms of E and/or P-induced in vivo proliferation, in the normal rat mammary gland and in hormone-dependent rat mammary cancers which share many characteristics with the normal human breast and hormone-dependent breast cancers. We show that E+P treatment induced significantly greater proliferation in both the normal gland and mammary cancers compared to E alone. In both the normal gland and tumors, E+P-induced proliferation was mediated through the increased production of amphiregulin (Areg), an epidermal growth factor receptor (EGFR) ligand, and the activation of intracellular signaling pathways (Erk, Akt, JNK) downstream of EGFR that regulate proliferation. In vitro experiments using rat primary mammary organoids or T47D breast cancer cells confirmed that Areg and the synthetic progestin, R5020, synergize to promote cell proliferation through EGFR signaling. Iressa, an EGFR inhibitor, effectively blocked this proliferation. These results indicate that mediators of cross talk between E, P, and EGFR pathways may be considered as relevant molecular targets for the therapy of hormone-dependent breast cancers, especially in premenopausal women

Partial Inhibition of Estrogen-Induced Mammary Carcinogenesis in Rats by Tamoxifen: Balance between Oxidant Stress and Estrogen Responsiveness

Epidemiological and experimental evidences strongly support the role of estrogens in breast tumor development. Both estrogen receptor (ER)-dependent and ER-independent mechanisms are implicated in estrogen-induced breast carcinogenesis. Tamoxifen, a selective estrogen receptor modulator is widely used as chemoprotectant in human breast cancer. It binds to ERs and interferes with normal binding of estrogen to ERs. In the present study, we examined the effect of long-term tamoxifen treatment in the prevention of estrogen-induced breast cancer. Female ACI rats were treated with 17β-estradiol (E2), tamoxifen or with a combination of E2 and tamoxifen for eight months. Tissue levels of oxidative stress markers 8-iso-Prostane F2α (8-isoPGF2α), superoxide dismutase (SOD), glutathione peroxidase (GPx), catalase, and oxidative DNA damage marker 8-hydroxydeoxyguanosine (8-OHdG) were quantified in the mammary tissues of all the treatment groups and compared with age-matched controls. Levels of tamoxifen metabolizing enzymes cytochrome P450s as well as estrogen responsive genes were also quantified. At necropsy, breast tumors were detected in 44% of rats co-treated with tamoxifen+E2. No tumors were detected in the sham or tamoxifen only treatment groups whereas in the E2 only treatment group, the tumor incidence was 82%. Co-treatment with tamoxifen decreased GPx and catalase levels; did not completely inhibit E2-mediated oxidative DNA damage and estrogen-responsive genes monoamine oxygenase B1 (MaoB1) and cell death inducing DFF45 like effector C (Cidec) but differentially affected the levels of tamoxifen metabolizing enzymes. In summary, our studies suggest that although tamoxifen treatment inhibits estrogen-induced breast tumor development and increases the latency of tumor development, it does not completely abrogate breast tumor development in a rat model of estrogen-induced breast cancer. The inability of tamoxifen to completely inhibit E2-induced breast carcinogenesis may be because of increased estrogen-mediated oxidant burden

Эпидемиология и результаты терапии первой линии ВИЧ-ассоциированной лимфомы Ходжкина

Introduction. The risk of developing Hodgkin lymphoma (HL) with HIV infection is higher than in the general population, and the course of the disease itself is more aggressive. Currently, there is no unified approach to the treatment of HIV-related HL, and data on its epidemiology in the Russian Federation are limited.The objective was to study epidemiological characteristics, the used therapeutic tactics and the results of treatment for HIV-related HL.Methods and materials. The multicenter retrospective study included 46 patients with HIV- related HL treated in 9 centers of the Russian Federation. Descriptive statistics methods were used, the analysis of overall survival (OS) and progression-free survival (PFS) was performed using the Kaplan–Meier method.Results. HIV-related HL is more often represented by an advanced stage, B-symptoms, and extranodal lesions. The ABVD regimen was used as the first-line therapy in 60 % for HIV-related HL. The overall response to therapy was 81.6 %, and the 2-year OS and PFS were 85 % and 49 %, respectively. Factors that worsened OS were CD4+˂266 cells/mcL and general somatic status ECOG≥2. Введение. Вероятность развития лимфомы Ходжкина (ЛХ) на фоне ВИЧ-инфекции выше, чем в общей популяции, а течение заболевания имеет более агрессивный характер. В настоящий момент отсутствует единый подход к терапии ЛХ на фоне ВИЧ, а данные об ее эпидемиологии в Российской Федерации ограничены.Цель – изучить эпидемиологическую характеристику, применяемую терапевтическую тактику и результаты лечения лимфомы Ходжкина на фоне ВИЧ-инфекции.Методы и материалы. В многоцентровое ретроспективное исследование были включены 46 пациентов с диагнозом «ЛХ» на фоне ВИЧ, получавших лечение в девяти центрах Российской Федерации. Применяли методы описательной статистки, анализ общей выживаемости (ОВ) и беспрогрессивной выживаемости (БПВ) выполняли с использованием метода Каплана – Мейера.Результаты. ЛХ на фоне ВИЧ чаще представлена распространенной стадией, В-симптомами и экстранодальным поражением. В качестве терапии первой линии ЛХ на фоне ВИЧ в 60 % случаев использовалась схема ABVD. Общий ответ на терапию составил 81,6 %, а 2-летняя ОВ и БПВ составили 85 и 49 % соответственно. Факторами, снижающими ОВ, являлись уровень CD4+<266 кл/мкл и общесоматический статус ECOG≥2. Ключевые слова: лимфома Ходжкина, ВИЧ, CD4+, ECOG, многоцентровое исследование, терапия первой линии>˂ 266 кл/мкл и общесоматический статус ECOG≥2.

Lenalidomide for relapsed or refractory multiple myeloma

We report the activity of lenalidomide (revlimide – R), lenalidomide plus dexamethasone (Rd), lenalidomide plus bortezomib plus dexamethasone (RVd) in 34 patients with relapsed and refractory myeloma. For patients who received lenalidomide the overall response rate was 70.5 %. 38 % patients achieved very good partial response (VGPR) + complete response (CR). Median overall survival (OS) was 48 months. Lenalidomide may overcome the poor prognostic impact of various factors, particularly elevated beta (2)-microglobulin. Lenalidomide is highly active in elderly patients (&gt; 65 years). Significantly increased OS with a lenalidomide-based induction and lenalidomide maintenance therapy was revealed. The median duration of the overall response without lenalidomide maintenance therapy was 10 months. The median duration of the overall response with lenalidomide maintenance therapy was 20 months (р &lt; 0,05). Median OS with lenalidomide maintenance therapy was not reached. Median OS without lenalidomide maintenance therapy was 36 months (р &lt; 0.05). Side effects were predictable and manageable. The most common adverse events reported were neutropenia (38.3 %) and thrombocytopenia (23.7 %). Serious adverse events were rare.</p