Recombinant human NT-proBNP antigen (Immunogen grade,>95%) [His]

Objective: To investigate the role of volume-activated chloride channels (VACC) in invasion and migration of human endometrial cancer cell. Materials and Methods: Expression of voltage-gated chloride channel-3 (CLC-3) was detected by employing reverse transcriptase-polymerase chain reaction (RT-PCR) in human endometrial cancer Ishikawa cell line. Cell invasion and cell migration were determined by using the Transwell invasion and migration assay, respectively. NPPB, a Cl- channel blocker, was treated to observe the effects of volume-activated Cl- channel on invasion and migration of endometrial cancer cell. Results: CLC-3 RNA expression was observed in Ishikawa cell line. The authors showed that blockade of Cl- channels specifically inhibited invasion and migration of endometrial cancer Ishikawa cell line in a dose-dependent manner. VACC activation and subsequent regulatory volume decrease (RVD) were markedly suppressed by NPPB. Anion replacement studies indicate that permeation of Cl- ions through endometrial cancer Cl- channel is obligatory for regulatory volume decrease (RVD) induced by VACC. Moreover, [Ca2+](i) measurements indicated that VACC-mediated increase in [Ca2+](i) was one of the mechanisms of cancer cell invasion and migration. Conclusions: These data intensely suggest that VACC in endometrial cancer may facilitate tumor invasion and migration, presumably through inducing RVD and mediating [Ca2+](i) increase.

To study the properties of ion channels of the tapeworm Taenia crassiceps, mRNA was isolated from cysticerci and injected into mature oocytes of the frog Xenopus laevis and ion currents were recorded four days after injection with the two-electrode voltage clamp technique. Oocytes injected with mRNA of T. crassiceps expressed outward currents (I(TC)) that activated instantly after onset of the test pulse, followed by a slow inactivation at potentials over +40 mV, with a reversal potential of -23.2 +/- 5 mV. They were not affected by changes on monovalent cationic composition of external media, but replacement of external chloride by gluconate shifted significantly the reversal potential, suggesting that I(TC) are anion currents, with a permeability sequence of NO(3)(-) > Cl(-) > l(-) >> Gluconate. These currents were sensitive to changes of external pH but not to hypotonic challenges. They were significantly inhibited by DIDS, NPPB and Niflumic acid, but not by 9-anthracene. These results suggest that I(TC) are the result of expression of anion channels from the tapeworm T crassiceps. (C) 2008 Elsevier Inc. All rights reserved.