Mahdavi Mohammad Reza, Pourfarzad Farzin, Kosaryan Mehrnoush, Akbari Mohammad Taghi
Dept. of Medical Genetics, School of Medical Sciences, Tarbiat Modares University, Tehran, Iran.
Iran J Public Health. 2017 Jul;46(7):948-956.
The hematologic response to hydroxyurea (HU) is varied among β-thalassemia (BT) patients. The BCL11A and SOX6 genes are involved in response to HU. This study aimed to investigate the in-vitro responsiveness of HU among BT major patients homozygote for IVSII-1G>A mutation and XmnI single nucleotide polymorphism (SNP) in order to find whether the in-vitro Hb concentration is a predictor of clinical (HU) responsiveness.
In this case-control study, twenty BT patients homozygote for IVSII-1G>A mutation and XmnI SNP from Thalassemia Research Center, Sari, Iran in 2015 were selected and categorized into two groups of 10 Responder (R) and 10 Non-Responder (NR) according to their clinical HU response. Ten healthy individuals as a control group were also selected. Hematopoietic erythroid progenitors were expanded from peripheral blood. Hb concentration was measured using photometry method. The flow cytometry and real-time PCR methods were applied for the analysis of cell surface markers (CD71 and CD235a) and gene expression (BCL11A and SOX6), respectively.
R and NR groups produced higher amount of Basic Hb than C group in cell culture medium at day 14 (<0.05). After HU treatment, in R group, Hb levels was significantly elevated in comparison to NR and C group (<0.05). BCL11A expression was decreased after exposure to HU in all groups while SOX6 expression was only down-regulated in C group, and its expression was increased in R and NR groups after HU treatment.
Since different factors including wide networks of intracellular factors and individual differences between patients can affect response to HU in patients, the increasing Hemoglobin on culture medium alone cannot predict clinical responsiveness to that drug.
β地中海贫血（BT）患者对羟基脲（HU）的血液学反应各不相同。BCL11A和SOX6基因与对HU的反应有关。本研究旨在调查纯合IVSII-1G>A突变和XmnI单核苷酸多态性（SNP）的重型BT患者对HU的体外反应性，以确定体外血红蛋白浓度是否可预测临床（对HU的）反应性。
在这项病例对照研究中，选取了2015年来自伊朗萨里地中海贫血研究中心的20名纯合IVSII-1G>A突变和XmnI SNP的BT患者，并根据他们对HU的临床反应分为两组，每组10名反应者（R）和10名无反应者（NR）。还选取了10名健康个体作为对照组。从外周血中扩增造血红系祖细胞。采用光度法测量血红蛋白浓度。分别应用流式细胞术和实时聚合酶链反应方法分析细胞表面标志物（CD71和CD235a）和基因表达（BCL11A和SOX6）。
在第14天，R组和NR组在细胞培养基中产生的基础血红蛋白量高于C组（<0.05）。HU治疗后，R组的血红蛋白水平与NR组和C组相比显著升高（<0.05）。所有组在暴露于HU后BCL11A表达均降低，而SOX6表达仅在C组中下调，在HU治疗后R组和NR组中其表达增加。
由于包括广泛的细胞内因子网络和患者个体差异在内的不同因素会影响患者对HU的反应，仅培养基中血红蛋白的增加不能预测对该药物的临床反应性。
