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

(目的)肿瘤干细胞(CSC)具有多药耐药的特点，被认为是造成肿瘤细胞异质性的暴发源。本研究的目的是阐明CSC的维持机制，并建立CSC的调控方法。(材料和方法)以乳腺癌和结直肠癌细胞株为研究对象，检测了不同形态信号和抗癌药物不同激活状态下CSC的数量。根据Hoechst 33342染色(侧群)或CD24-/低CD44表达强度纯化CSCs。我们分析了CSC中形态原信号的活性。我们还检验了形态信号在CSC生长中的意义。接下来，我们研究了DAPT，假设的结直肠CSC因子Notch信号的抑制者，对抗癌药敏感性的影响。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。结果成功地检测和纯化了乳腺癌细胞株的SP组分和CD24-/Low CD44组分。这两个CSC组分，SP组分和CD24-/低CD44组分具有相同的主要种群，并具有耐药能力。Hedgehog(HH)信号通路的反式激活因子Gli1在两个CSC组分中都上调。HH信号活性的下调降低了CSC部分在全部细胞计数中的比例。同时，乳腺细胞分化的标志物ER激活了HH信号通路，推测为CSC因子。HH信号通路在肿瘤干细胞和分化癌细胞中的这种复杂作用的意义还有待进一步研究。作为Y-分泌酶抑制剂和Notch信号的抑制剂，DAPT增加了结直肠癌细胞对抗癌药的敏感性。进一步研究发现，DAPT的这种抗癌作用与Notch无关，可能与APC状态有关。(结论)HH信号通路可能是维持乳腺CSC所必需的。DAPT抑制结直肠癌的耐药能力，其靶点可能为阐明结直肠癌CSC的维持系统提供线索。较少

(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