There is accumulating evidence that the subfamily of large-conductance potassium (“big”, “BK”) channels are involved in diverse, and perhaps coordinated, protective or counteractive responses to local or generaliz...There is accumulating evidence that the subfamily of large-conductance potassium (“big”, “BK”) channels are involved in diverse, and perhaps coordinated, protective or counteractive responses to local or generalized ischemia and hypoxia. Although widely distributed, the physiological differences among BK channels which results from posttranslational modification (alternative splicing) and co-assembly with auxiliary modulatory subunits (<em>β</em><sub>1-4</sub> and <em>γ</em><sub>1-4</sub>), bestows localized differences in subunit composition, distribution, 2<sup>nd</sup>-messenger coupling, and pharmacologic properties. Due to the ubiquitous nature of BK channels and the multiplicity of subtypes, they have many potential therapeutic applications in the maintenance of oxygen homeostasis, cerebro- and cardio-protection, and stimulation of respiration in response to drug-induced respiratory depression. BK channels may also offer other potentially broad and underrecognized promising targets for novel pharmaceutical development.展开更多
Objective： Our group has previously observed that in patients with small-cell lung cancers （SCLCs）, the expression of a tumor antigen, glioma big potassium （gBK） ion channel, is higher at the time of death than w...Objective： Our group has previously observed that in patients with small-cell lung cancers （SCLCs）, the expression of a tumor antigen, glioma big potassium （gBK） ion channel, is higher at the time of death than when the cancer is first treated by surgical resection. This study aimed to determine whether this dichotomy was common in other potential lung tumor antigens by examining the same patient samples using our more extensive profile analysis of tumor-antigen precursor protein （TAPP）. We then tested the hypothesis that therapeutic intervention may inadvertently cause this increased gBK production. Methods： SCLC samples （eight surgical resections and three autopsy samples） and three control lungs were examined by quantitative real-time polymerase chain reaction for 42 potential TAPPs that represent potential T-cell-mediated immunological targets. Results： Twenty-two TAPP mRNAs displayed the same profile as gBK, i.e., more mRNAs were expressed at autopsy than in their surgical counterparts. B-cyclin and mouse double minute 2, human homolog of PS3-binding protein were elevated in both autopsy and surgical specimens above the normal-lung controls. When HTB119 cells were incubated with doxorubicin, gBK was strongly induced, as confirmed by intracellular flow cytometry with a gBK-specific antibody. Conclusion： Our findings suggested that more immunological targets became available as the tumor responded to chemotherapy and proceeded toward its terminal stages.展开更多
文摘There is accumulating evidence that the subfamily of large-conductance potassium (“big”, “BK”) channels are involved in diverse, and perhaps coordinated, protective or counteractive responses to local or generalized ischemia and hypoxia. Although widely distributed, the physiological differences among BK channels which results from posttranslational modification (alternative splicing) and co-assembly with auxiliary modulatory subunits (<em>β</em><sub>1-4</sub> and <em>γ</em><sub>1-4</sub>), bestows localized differences in subunit composition, distribution, 2<sup>nd</sup>-messenger coupling, and pharmacologic properties. Due to the ubiquitous nature of BK channels and the multiplicity of subtypes, they have many potential therapeutic applications in the maintenance of oxygen homeostasis, cerebro- and cardio-protection, and stimulation of respiration in response to drug-induced respiratory depression. BK channels may also offer other potentially broad and underrecognized promising targets for novel pharmaceutical development.
文摘Objective： Our group has previously observed that in patients with small-cell lung cancers （SCLCs）, the expression of a tumor antigen, glioma big potassium （gBK） ion channel, is higher at the time of death than when the cancer is first treated by surgical resection. This study aimed to determine whether this dichotomy was common in other potential lung tumor antigens by examining the same patient samples using our more extensive profile analysis of tumor-antigen precursor protein （TAPP）. We then tested the hypothesis that therapeutic intervention may inadvertently cause this increased gBK production. Methods： SCLC samples （eight surgical resections and three autopsy samples） and three control lungs were examined by quantitative real-time polymerase chain reaction for 42 potential TAPPs that represent potential T-cell-mediated immunological targets. Results： Twenty-two TAPP mRNAs displayed the same profile as gBK, i.e., more mRNAs were expressed at autopsy than in their surgical counterparts. B-cyclin and mouse double minute 2, human homolog of PS3-binding protein were elevated in both autopsy and surgical specimens above the normal-lung controls. When HTB119 cells were incubated with doxorubicin, gBK was strongly induced, as confirmed by intracellular flow cytometry with a gBK-specific antibody. Conclusion： Our findings suggested that more immunological targets became available as the tumor responded to chemotherapy and proceeded toward its terminal stages.
