2012-08-012024-05-14https://scholars.lib.ntu.edu.tw/handle/123456789/660561摘要：急性骨髓性白血病是大人常見的血液腫瘤疾病之一，除了用all trans retinoic acid治療acute promyelocytic leukemia (APL, AML M3)外，其他的病患仍採用傳統標準化療方式作治療。然而這種治療方式只有70%會達到緩解，這當中有80%之後會復發，平均存活時間只有18個月，非常不理想。最近許多研究報告指出，復發的主要原因之一是所謂骨髓微環境提供血癌細胞一個得以抗拒化療傷害的場所。骨髓微環境中的endosteal niche主要由osteoblasts與旁邊的stromal cells所組成，一般是正常幹細胞居留的場所。相對於大氣壓力(21%氧濃度)，骨髓微環境中氧氣的濃度是偏低的，其中endosteal niche約1%左右；而在血管附近的vascular niche則約5-6%。我們假設血癌幹細胞在骨髓微環境中有一套生存方式得以躲過化學治療的藥效。因此，我們用Agilent SurePrint G3 Human GE 8x60K進行microarray實驗配合rank consistant lowess統計程式分析，比較OCI/AML3血癌細胞分別在正常氧濃度(21%O2)與低氧濃度(1%O2)培養8小時後基因表現差異的圖譜。其中差異性最高的是adrenomedullin (ADM)，其在低氧濃度環境中上升了9.062倍。進一步以Q-RT-PCR確認多種血癌細胞株都有類似的現象(8-200x)。文獻報告指出，ADM在許多固態腫瘤中具有臨床意義，但是在血液腫瘤中還沒有報告。我們同時也發現這些細胞都會表現ADM receptor- ADMR，而只有K562會同時表現另一ADM receptor- CRLR。另外，Q-RT-PCR也確認另一個分子STC2 (stanniocalcin 2)在低氧濃度環境中也有上升(6-500x)的現象。文獻也報告STC2在許多固態腫瘤中也具有重要臨床意義，但是在血液腫瘤中也沒有報告。過去我們實驗室主要利用AML病患的基因與染色體的變異作為評估病患預後的情形，甚至於可以作為診斷與病情追蹤的生物指標。另一方面，我們也針對骨髓微環境中的因子作一些分析，如：VEGF/PlGF、VEGF-C、Ang-1、Tie-2、MMP-2、MMP-9、osteopontin都是對病患預後有影響的因子。因此，在此三年計劃中，我們將對於與低氧濃度相關因子ADM與STC2在AML的調控機制上做一個完整性的探討。另一方面，我們也將同時以immunohistochemical stain了解ADM及其受體與STC2在各類AML病患骨髓切片上的分佈情形，還有骨髓微環境內ADM與STC2的血漿濃度變化；藉以釐清ADM與STC2在AML疾病上擔任生物指標的可能性。<br> Abstract: Acute myeloid leukemia is one of the most important hematological malignancies. Only acute promyelocytic leukemia (APL, AML M3) patients could have good response after receiving combined all-trans retinoic acid (ATRA) and chemotherapy. Other AML patients often suffered from relapse after conventional induction chemotherapy. The bone marrow (BM) microenvironment is one of the reasons to protect leukemia cells from those treatments and consequently contribute to eventual disease relapse. Two stem cell “niches” was described in the BM microenvironment: one is the endosteal niche and the other is vascular niche. The endosteal niche composed of osteoblasts and stromal cells maintains stem cell reserve; whereas the vascular niche maintains a boundary between immature cells and peripheral blood circulation. It has been verified that the O2 concentration gradient is from under 1% (endosteal niche) to 6% (vascular inche) within the human BM. In order to figure out the significance of hypoxia niche in leukemia, we compare the gene expression spectrum of OCI/AML3 leukemia cells incubated in hypoxia (1%) and in normoxia (21%) with Agilent SurePrint G3 Human GE 8x60K microarray coupled with rank consistant lowess. Adrenomedullin (ADM, Accession number; NM_001124) and stanniocalcin 2 (STC2, NM_003714) were two of the molecules significantly up-regulated in OCI/AML3 at hypoxia incubation. Further Q-RT-PCR confirmed this up-regulation of ADM and STC2 with 8-200 and 6-500 folds increase, respectively, in various leukemia cell lines under hypoxia condition. ADM and STC2 have been reported to be regulated by hypoxia-inducible factor (HIF-1) and function as cell growth-promoting factor on several solid tumors, such as glioblastoma, colorectal cancer, esophageal squamous cell carcinoma, ovarian cancer, pancreatic cancer, and clear-cell renal carcinoma. However, the biological mechanism of ADM and STC2 in leukemogenesis and the clinical implication of ADM and STC2 on AML patients remain unclear.In this three-year project, we will elucidate the significance of ADM and STC2 in AML from several aspects: 1). to figure out the molecular mechanism of ADM and STC2 in leukemogenesis and leukemia progression; 2). to evaluate if ADM and STC2 could be biomarker for prognosis prediction; 3). to figure out the significance of epigenetic regulation of ADM and STC2 in leukemia. A better understanding of these subjects may provide additional approaches for clinical application in the near future.腎上腺髓質素低氧急性骨髓性白血病adrenomedullin (AM)hypoxiaacute myeloid leukemia (AML)