Effects of red clover extracts on breast cancer cell migration and invasion.

Postmenopausal hormone therapy is associated with increased incidence of breast cancer. For this reason alternative therapeutic options to treat menopausal symptoms have been developed. Red clover extracts (RCE) are rich in isoflavones, particularly genistein and daidzein and they have been proved to be effective in reducing vasomotor symptoms in a number of studies. Due to their partial selectivity of action on estrogen receptors (ERs) these compounds have been claimed to be safer on the breast. In this article, we explored the action of RCE on motility and invasion of ER positive breast cancer cells and we partially characterized the signaling mechanisms. The principal isoflavones contained in RCE acted as weak estrogenic compounds when administered alone. However, when provided in association with physiological amounts of estradiol, RCE acted as estrogen antagonist on remodeling of actin cytoskeleton that are requested to enact cell movement and with related modifications of the activity of actin-binding proteins, such as moesin. These results offer novel information on the molecular actions of isoflavones contained in red clover on breast cancer cells, supporting a possible action of these molecules as natural selective estrogen receptor modulators in the presence of physiological amounts of estrogens.

Progesterone receptor enhances breast cancer cell motility and invasion via extranuclear activation of focal adhesion kinase.

While progesterone plays multiple roles in the process of breast development and differentiation, its role in breast cancer is less understood. We have shown previously that progestins stimulate breast cancer cell migration and invasion because of the activation of rapid signaling cascades leading to modifications in the actin cytoskeleton and cell membrane that are required for cell movement. In this study, we have investigated the effects of progesterone on the formation of focal adhesion (FA) complexes, which provide anchoring sites for cell attachment to the extracellular matrix during cell movement and invasion. In T47-D breast cancer cells, progesterone rapidly enhances FA kinase (FAK) phosphorylation at Tyr(397) in a time- and concentration-dependent manner. As a result, exposure to progesterone leads to increased formation of FA complexes within specialized cell membrane protrusions. The cascade of events required for this phenomenon involves progesterone receptor interaction with the tyrosine kinase c-Src, which activates the phosphatidylinositol-3-kinase/Akt pathway and the small GTPase RhoA/Rho-associated kinase complex. In the presence of progesterone, T47-D breast cancer cells display enhanced horizontal migration and invasion of three-dimensional matrices, which is reversed by small interfering RNAs abrogating FAK. In conclusion, progesterone promotes breast cancer cell movement and invasion by facilitating the formation of FA complexes via the rapid regulation of FAK. These results provide novel mechanistic views on the effects of progesterone on breast cancer progression, and may in the future be helpful to develop new strategies for the treatment of endocrine-sensitive breast cancers.

Effects of raloxifene on breast cancer cell migration and invasion through the actin cytoskeleton.

Raloxifene (RAL) is a selective oestrogen receptor modulator (SERM) approved for the prevention and treatment of osteoporosis and for the prevention of breast cancer in postmenopausal women. However, little is known on the effects of this SERM on breast cancer cell metastasis, which is the main cause of morbidity and death. Cell movement is critical for local progression and distant metastasis of cancer cells. These processes rely on the dynamic control of the actin cytoskeleton and of cell membrane morphology. The aim of the present study was to characterize the effects of RAL or of 17beta-estradiol (E2) plus RAL on oestrogen receptor (ER) positive T47-D breast cancer cell cytoskeletal remodelling, migration and invasion. Our findings show that, when given alone, RAL induces a weak actin cytoskeleton remodelling in breast cancer cells, with the formation of specialized cell membrane structures implicated in cell motility. However, in the presence of physiological amounts of estradiol, which potently drives breast cancer cell cytoskeletal remodelling and motility, RAL displays a powerful inhibitory effect on oestrogen-promoted cell migration and invasion. These actions are plaid through an interference of RAL with an extra-nuclear signalling cascade involving G proteins and the RhoA-associated kinase, ROCK-2, linked to the recruitment of the cytoskeletal controller, moesin. Hence, in the presence of estradiol, RAL acts as an ER antagonist. These results highlight a novel mechanism of action of the SERM raloxifene that might be important for the interference of breast cancer progression or metastasis induced by oestrogens in postmenopausal women.

Pustulosis subcórnea de Sneddo-Wilkinson / Subcorneal pustulosis of Sneddon-Wilkinson

Presentamos dos pacientes con pustulosis subcórnea de Sneddon Wilkinson diagnosticados en el Servicio de Dermatología del Hospital de Pediatría “Prof. Dr. Juan P. Garrahan”. Al examen físico se observaban múltiples pústulas fláccidas que asentaban sobre una piel eritematosa; en uno de los casos la distribución era generalizada a predominio de pliegues y parte proximal de los miembros, mientras que en el otro las lesiones se encontraban localizadas en la cula subcórnea con infiltrado a predominio neutrofílico en el interior, con inmunofluorescencia directa (IFD) negativa. El tratamiento inicial instaurado fue dapsona. Uno de ellos también requirió tratamiento con corticoides locales con múltiples recidivas de sus lesiones. Destacamos la escasa frecuencia de esta entidad en la niñez, las diferentes respuestas al tratamiento instaurado y la importancia del seguimiento de estos pacientes.