日前，致力于让脐带血移植治疗白血病和淋巴瘤患者更安全、更有效的科学家们取得了一项新的进展。相关成果发表在Blood杂志上（论文标题：Erythropoietin modulation is associated with improvedhoming and engraftment after umbilical cord blood transplantation），并配以题为“让脐带血呼吸新鲜空气”的评论文章。
通过一个小型的临床试验，科学家们发现了一种叫做红细胞生成素（erythropoietin，EPO）的激素在脐带血移植中的重要性。降低人体EPO水平有助于一个称为归巢（homing）的过程。通过这一过程，新移植的造血干细胞迁移到患者的骨髓中，开始修复机体产生健康血细胞和免疫细胞的能力。
目前，脐带血移植存在的一个挑战是：脐带血需要很长的时间才能归巢到骨髓中，只有较少的细胞能到达它们的“目的地”。研究人员一直在寻找克服这一限制的策略。在这一成果中，科学家们发现，通过阻断EPO-EPO受体信号能够改善脐带血移植。
这一临床试验共包括15名患者。在接受脐带血移植前，研究人员首先通过高压氧气疗法（hyperbaric oxygen therapy）阻断了癌症患者的EPO信号。具体来说，氧气疗法是指让患者进入一个专业的房间，呼吸100%的氧气。
研究表明，这一方法是安全的，患者对其耐受良好；而且还有效降低了EPO水平。与未接受氧气疗法的其他患者相比，参与这一临床试验的志愿者还更早恢复了他们的血细胞计数，且在恢复的过程中更早“摆脱”输血（blood transfusion）。
这一研究克服了脐带血移植的关键障碍，使其有望成为许多患者可行的选择。目前，研究人员正在开展II期临床研究，进一步探索高压氧气在脐带血移植中的使用。
Erythropoietinmodulation is associated with improved homing and engraftment after umbilicalcord blood transplantation
DOI: https://doi.org/10.1182/blood-2016-05-715292
Umbilical cord blood (UCB) engraftmentis in part limited by graft cell dose, generally one log less than that of bonemarrow (BM)/peripheral blood (PB) cell grafts. Strategies toward increasinghematopoietic stem/progenitor cell (HSPC) homing to BM have been assessed toimprove UCB engraftment. Despite recent progress, a complete understanding ofhow HSPC homing and engraftment are regulated is still elusive. We provideevidence that blocking erythropoietin (EPO)-EPO receptor (R) signaling promoteshoming to BM and early engraftment of UCB CD34+ cells. A significant populationof UCB CD34+ HSPC expresses cell surface EPOR. Exposure of UCB CD34+ HSPC toEPO inhibits their migration and enhances erythroid differentiation. Thismigratory inhibitory effect was reversed by depleting EPOR expression on HSPC.Moreover, systemic reduction in EPO levels by hyperbaric oxygen (HBO) used in apreclinical mouse model and in a pilot clinical trial promoted homing oftransplanted UCB CD34+ HSPC to BM. Such a systemic reduction of EPO in the hostenhanced myeloid differentiation and improved BM homing of UCB CD34+ cells, aneffect that was overcome with exogenous EPO administration. Of clinicalrelevance, HBO therapy before human UCB transplantation was well-tolerated andresulted in transient reduction in EPO with encouraging engraftment rates andkinetics. Our studies indicate that systemic reduction of EPO levels in thehost or blocking EPO-EPOR signaling may be an effective strategy to improve BMhoming and engraftment after allogeneic UCB transplantation. This clinicaltrial was registered at www.ClinicalTrials.gov (#NCT02099266).
来源：生物探索
