Marks P A, Murate T, Kaneda T, Ravetch J, Rifkind R A
Symp Fundam Cancer Res. 1984;37:327-40.
MELC are virus-transformed cells capable of indefinite proliferation that are blocked in differentiation at an early erythroid precursor stage, probably corresponding to CFU-e. A variety of agents, among them HMBA and Me2SO, induce MELC to terminal differentiation and expression of characteristics similar to that associated with normal erythropoiesis. During inducer-mediated terminal differentiation, modulation of expression of a number of genes occurs. Studies to date have characterized inducer-mediated alterations in chromatin structure associated with activation of alpha and beta maj globin genes. Inducer-mediated MELC terminal cell division is also associated with a decrease in the synthesis of the nuclear protein p53, a protein that has been implicated as a requirement for the progression from G1 to S in the cell cycle. HMBA-mediated commitment to terminal cell division is suppressed by steroid. HMBA induces accumulation of mRNAs that may be required for commitment to terminal cell division and whose translation is suppressed by dexamethasone. At least two inducer-activated genes have been identified that may play a role in the transition of terminal cell division.
MELC是病毒转化的细胞，能够无限增殖，在早期红系前体细胞阶段分化受阻，可能对应于CFU-e。多种试剂，其中包括HMBA和Me2SO，可诱导MELC进行终末分化并表达与正常红细胞生成相关的特征。在诱导剂介导的终末分化过程中，许多基因的表达会发生调节。迄今为止的研究已经对与α和β珠蛋白基因激活相关的诱导剂介导的染色质结构改变进行了表征。诱导剂介导的MELC终末细胞分裂也与核蛋白p53的合成减少有关，p53蛋白被认为是细胞周期从G1期进入S期所必需的。HMBA介导的终末细胞分裂承诺受到类固醇的抑制。HMBA诱导可能是终末细胞分裂承诺所需的mRNA积累，其翻译受到地塞米松的抑制。已经鉴定出至少两个诱导剂激活的基因，它们可能在终末细胞分裂的转变中起作用。
