Reduction of breast cancer cell migration via up-regulation of TASK-3 two-pore domain K+ channel.

AIM: Many kinds of K(+) channels are expressed in a variety of cells, including cancer cells. However, only a small amount of research has explored the relationship between voltage-independent K(+) channels and breast cancer. This study was performed to investigate whether changes in two-pore domain K(+) (K(2P) ) channel expression levels are related to the migration of human breast cancer cells. METHODS: K(2P) channel gene/protein expression levels were compared between MCF-7 (a non-invasive cell) and MDA-MB-231 (an invasive cell) using reverse transcriptase (RT)-polymerase chain reaction (PCR), real-time PCR, Western blotting and immunocytochemistry. The relationship between K(2P) channel expression level and cell migration was analysed using gene overexpression and knock-down techniques. Functional expression of TASK-3 in MCF-7 and MDA-MB-231 cells was recorded using patch-clamp technique. RESULTS: Of K(2P) channels, TASK-3 mRNA and protein were highly expressed in MCF-7 cells compared with those in MDA-MB-231 cells. Overexpression of TASK-3 in breast cancer cells reduced migration and invasion, whereas silencing of TASK-3 increased the migration and invasion. The TASK-3 expression level was decreased by phorbol myristate acetate (PMA), a PKC activator. PMA also enhanced the cell migration in MDA-MB-231 cells. CONCLUSION: These results show that an increase in TASK-3 expression levels, which could be modulated by PKC activation, reduces cell migration/invasion in breast cancer cells and suggest that modulation of TASK-3 expression may regulate metastasis of breast cancer cells.

Effects of the aqueous extract of epimedii herba on the antibody responses in mice.

Antibodies and cytokines in serum were detected in male ICR mice treated with the aqueous extract of Epimedii Herba (AEEH) at doses of 40, 120 and 360 mg/kg orally for 2 weeks. Effects of AEEH on antibody forming responses were assessed by enzyme linked immunosorbent assay (ELISA) of immunoglobulin (Ig) levels in serum collected 7 days after priming with ovalbumin (OVA) in complete Freund's adjuvant (CFA) or immediately without priming at week 2. The relative spleen weight was significantly increased by AEEH, compared with controls, especially at a dose of 120 mg/kg of it after priming with OVA and 40 mg/kg without priming, respectively. However, body weight gain was slightly decreased in AEEH-fed mice. The enhancement of total serum IgG and IgG1 levels in unprimed mice was statistically significant in mice fed 40 mg/kg AEEH. Total serum IgG2a levels and Il-4 secretion were also statistically augmented by all groups of AEEH treatment. A tendency to marked increase of total serum IgM level and IFN-gamma secretion was also observed in mice fed 40 and 120 mg/kg AEEH but not those fed 360 mg/kg AEEH. When mice were immunized with OVA, furthermore, a marked stimulation of antibody formation and cytokines secretion was observed in all groups of AEEH-fed mice compared with controls. These findings indicate that AEEH at therapeutic concentrations enhances the production of antibodies and cytokines in mice, and the enhancing effects are more marked when the mice were immunized with OVA. Thus, these results suggest that AEEH is effective on Th cell functions, and protective effects on host against immune diseases.

Induction of oral tolerance to Japanese cedar pollen.

Oral tolerance is thought to play a role in preventing allergic responses and immune-mediated diseases. An improved mouse model of the oral tolerance to Japanese cedar pollen (JCP) as antigen was developed in order to detect induction of the tolerance, and the immunological characteristics of this model were also elucidated. Oral tolerance was induced by C3H/ HeN mice given an oral administration of 10 mg JCP 7 days before immunization with an i.p. injection of 0.1 mg JCP in complete Freunds adjuvant (CFA). The effects of oral JCP on systemic immunity were assessed by enzyme-linked immunosorbent assay (ELISA) of immunoglobulin (Ig) levels in serum collected on day 7 or 14 after immunization. Oral tolerance to JCP was adequately induced on day 7 after immunization and was more effective in C3H/HeN mice than in BALB/c mice. The tolerance was primarily concerned with the decreased serum levels of antigen-specific IgG. In these mice, oral administration of JCP also suppressed various immune responses to the antigen including delayed-type hypersensitivity (DTH), total IgE level and anti-JCP IgG1 level. The suppression of these immune responses by the oral antigen was associated with a significant reduction in interleukin-4 (IL-4) production. These findings therefore indicate that this C3H/HeN mice model has potential use in detecting the induction of oral tolerance by JCP, and suggest that this tolerance model may be effective in the treatment and prevention of allergic responses caused by the antigen.

Effect of biphenyl dimethyl dicarboxylate on the humoral immunosuppression by ethanol.

The present study was undertaken to investigate the effect of biphenyl dimethyl dicarboxylate (PMC) on the humoral immunosuppression by ethanol (EtOH) in ICR mice. PMC at a dose of 6 mg/kg was orally administered to mice daily for 28 consecutive days, and the control mice were given vehicle. Mice treated with EtOH were given freely with 20% EtOH instead of water. The results of this study are summarized as follows; a gain of body weight and the relative weights of spleen and liver were significantly increased by combination of PMC and EtOH, as compared with those in mice treated with EtOH alone. Splenic plaque forming cells (PFC) and hemagglutination (HA) titers to sheep red blood cells (SRBC), and the secondary IgG antibody response to bovine serum albumin (BSA) were decreased by the treatment of EtOH alone, then restored to normal level by PMC treatment. The elevations of serum glutamic-pyruvic transaminase (S-GPT) and total protein levels caused by EtOH were reduced to normal level by the combination of PMC and EtOH. In addition, lower serum albumin and A/G ratio were also increased to normal level. These findings indicate that PMC has a protective effect against EtOH-induced humoral immunosuppression.