Pessino A, Passalacqua M, Sparatore B, Patrone M, Melloni E, Pontremoli S
Institute of Biological Chemistry, University of Genova, Italy.
Biochem J. 1995 Dec 1;312 ( Pt 2)(Pt 2):549-54. doi: 10.1042/bj3120549.
The potential regulatory role of delta protein kinase C (delta PKC) in murine erythroleukaemia cell differentiation was studied by using antisense oligodeoxynucleotides targeting the translation initiation region of mouse delta PKC mRNA. Cell treatment with antisense oligonucleotides, at a concentration of 20 microM, followed by hexamethylenebisacetamide induction, produced a specific 2-fold increase in the differentiation rate of both slowly and rapidly differentiating murine erythroleukaemia cell clones. Cell permeabilization by a cationic lipid resulted in a decrease of one order of magnitude in the amounts of antisense oligonucleotides necessary to elicit the maximal response, and accelerated the kinetics of the stimulatory effect. These changes in murine erythroleukaemia cell differentiation rates, observed in both cell clones, were associated with 60% and 50% decreases, respectively, in delta PKC immunoreactive protein in slowly and rapidly differentiating cells. The present results indicate strongly that basal levels of delta PKC in murine erythroleukaemia cells are essential in regulating the initial differentiation rate of these cells in response to chemical induction, and provide further evidence that this PKC isoform plays a fundamental role in maintaining the undifferentiated phenotype of murine erythroleukaemia cells.
通过使用针对小鼠δ蛋白激酶C（δPKC）mRNA翻译起始区域的反义寡脱氧核苷酸，研究了δ蛋白激酶C在小鼠红白血病细胞分化中的潜在调节作用。用浓度为20μM的反义寡核苷酸处理细胞，随后进行六亚甲基双乙酰胺诱导，使缓慢和快速分化的小鼠红白血病细胞克隆的分化率均特异性增加了2倍。阳离子脂质介导的细胞透化作用使引发最大反应所需的反义寡核苷酸量减少了一个数量级，并加快了刺激作用的动力学。在两个细胞克隆中观察到的小鼠红白血病细胞分化率的这些变化，分别与缓慢和快速分化细胞中δPKC免疫反应性蛋白减少60%和50%相关。目前的结果有力地表明，小鼠红白血病细胞中δPKC的基础水平对于调节这些细胞对化学诱导的初始分化率至关重要，并进一步证明这种PKC同工型在维持小鼠红白血病细胞的未分化表型中起重要作用。
