Is there a role for voltage-gated Na+ channels in the aggressiveness of breast cancer?

Breast cancer is the most common cancer among women and its metastatic potential is responsible for numerous deaths. Thus, the need to find new targets for improving treatment, and even finding the cure, becomes increasingly greater. Ion channels are known to participate in several physiological functions, such as muscle contraction, cell volume regulation, immune response and cell proliferation. In breast cancer, different types of ion channels have been associated with tumorigenesis. Recently, voltage-gated Na+ channels (VGSC) have been implicated in the processes that lead to increased tumor aggressiveness. To explain this relationship, different theories, associated with pH changes, gene expression and intracellular Ca2+, have been proposed in an attempt to better understand the role of these ion channels in breast cancer. However, these theories are having difficulty being accepted because most of the findings are contrary to the present scientific knowledge. Several studies have shown that VGSC are related to different types of cancer, making them a promising pharmacological target against this debilitating disease. Molecular biology and cell electrophysiology have been used to look for new forms of treatment aiming to reduce aggressiveness and the disease progress.

Degradabilidade in situ da matéria seca de forrageiras tropicais obtidas em diferentes épocas de corte / In situ dry matter degradation of tropical forages harvested at different ages

Estimou-se a degradabilidade in situ de 10 forrageiras tropicais em três idades ao corte (21, 42 e 63 dias) e em três tempos de incubação (6, 24 e 96h). As forrageiras utilizadas foram: Andropogon gayanus cv. Planaltina, Brachiaria brizantha (acessos 3401, 3413 e 3451 CPAC), Cenchrus ciliaris (acessos 79119, 79146, 79148, 80199 e 81302 CPATSA) e Panicum maximum (3616 CPAC). Os acessos de B. brizantha, P. maximum e A. gayanus apresentaram os maiores valores de degradabilidade da matéria seca e os de C. ciliaris os valores mais baixos. Todas as forrageiras apresentaram queda no desaparecimento da matéria seca com o avanço da idade. Os acessos de Brachiaria brizantha 3413 e 3451 apresentaram as maiores degradabilidades efetivas.