Development the new cancer treatment targeting the regulation system of cancer stem cells

（目的）癌症干细胞（Cancer stem cell， CSC）具有多药耐药能力，被认为是造成癌细胞异质性的爆发源。本研究的目的是阐明CSC的维持机制，建立CSC的控制方法。（材料和方法）以乳腺癌和结直肠癌细胞株为研究对象，在不同的形态素信号和抗癌药物的激活状态下，检测菌株中CSCs的数量。根据Hoechst 33342染色强度（SP（侧群））或CD24-/lowCD44+表达纯化CSCs。我们分析了CSC中形态因子信号的活性。我们还检查了形态因子信号对CSC生长的意义。接下来，我们检测了假定的结直肠CSC因子Notch信号抑制因子DAPT对抗癌药物敏感性的影响。此外，我们还检测了针对Hedgehog信号通路受体Patched1的抗体对CSC生长的影响。（结果）我们成功地检测和纯化了乳腺癌细胞株的SP部分和CD24-/低CD44+部分。这两个CSC部分，SP部分和CD24-/低CD44+部分，共享主要人群，具有耐药能力。Hedgehog （Hh）信号通路的转录激活因子Gli1在两组CSC中均上调。Hh信号活性的下调降低了CSC部分占所有细胞总数的比例。同时，被认为是CSC因子的Hh信号通路被ER激活，这是乳腺细胞分化的一个里程碑。Hh信号通路在癌症干细胞和分化癌细胞中的复杂作用意义有待进一步研究。DAPT是y分泌酶抑制剂和Notch信号的抑制因子，可增加结直肠癌细胞对抗癌药物的敏感性。进一步研究发现，DAPT的这种抗癌能力与Notch无关，可能与APC状态有关。（结论）Hh信号通路可能对乳腺CSC的维持至关重要。DAPT抑制结直肠癌的抗阻能力，DAPT的靶点可能为阐明结直肠癌CSC的维持系统提供线索。少

(Purpose) Cancer stem cell (CSC), characterized by the ability of multi-drug resistance, assumed as outbreak source to create heterogeneity of cancer cells. The purpose of this research is to elucidate the mechanism of maintaining CSC and to establish control method for CSC.(Materials and a methods) With breast cancer and colo-rectal cancer cell strains, we examined the number of CSCs in the strains under the different activation state of the various morphogen signals and anticancer agents. CSCs were purified based on the intensity of Hoechst 33342 staining (SP (side population)) or CD24-/lowCD44+ expression. We analyzed activity of the morphogen signals in CSC. We also checked the significance of morphogen signals on CSC growth. Next we examined influence of DAPT, suppressor of assumed colo-rectal CSC factor Notch signal, on sensitivity of anti-cancer agent. Furthermore, we inspected the effect of antibodies raised against Patched1, receptor of Hedgehog signaling pathway, on CSC growt … More h.(Results) We succeeded in the detection and purification of SP fraction and CD24-/low CD44+ fraction of breast cancer cell strain. These two CSC fractions, SP fraction and CD24-/low CD44+ fraction, shared major population and had the drug resistant ability. Gli1, trancactivator of the Hedgehog (Hh) signaling pathway, was up-regulated in both CSC fractions. Down-regulation of the Hh signaling activity reduced the ratio of the CSC fractions of the whole all cell counts. Meanwhile, Hh signaling pathway, supposed CSC factor, was activated by ER, a landmark of the breast cell differentiation. The significance of this complicated role of Hh signaling pathway in both cancer stem cells and differentiated cancer cells has to be further examined. DAPT, the suppressor of Y-secretase inhibitor and the Notch signal, increased the sensitivity of colo-rectal cancer cells to the anti-cancer agent. Further examination revealed that this anti-cancer ability of DAPT is unrelated to Notch, and may be involved in APC status.(Conclusion) Hh signaling pathway may be essential for the maintenance of breast CSC. DAPT suppressed the drag resistance ability of colorectal cancer and the target of DAPT may give clues to elucidate the maintenance system of colorectal CSC. Less