Ferrucci L, Mezzanotte R, Vanni R, Stuppia R, Guanciali-Franchi P, Calabrese G, Palka G, Bianchi U, Sumner A T
Dipartimento di Biologia, Facoltà di Science M.F.N., II Università di Roma, Italy.
Cancer Genet Cytogenet. 1988 Sep;34(2):251-6. doi: 10.1016/0165-4608(88)90268-3.
The restriction endonucleases HpaII and MspI both cleave the nucleotide sequence CCGG, but the action of HpaII is inhibited if the internal cytosine is methylated. HpaII and MspI were used on fixed chromosomes from bone marrow cells of individuals suffering from chronic myelogenous leukemia and healthy individuals. We found that MspI acts with the same efficiency on all chromosome samples, whereas HpaII extracts more DNA from the chromosomes of leukemic individuals than from the chromosomes of nonleukemic individuals. We postulate that demethylation of cytosine in the CpG dinucleotide of leukemic cell DNA accounts for our findings.
限制性内切酶HpaII和MspI都能切割核苷酸序列CCGG，但如果内部的胞嘧啶发生甲基化，HpaII的作用就会受到抑制。HpaII和MspI被用于处理慢性粒细胞白血病患者和健康个体骨髓细胞的固定染色体。我们发现，MspI对所有染色体样本的作用效率相同，而HpaII从白血病个体的染色体中提取的DNA比从非白血病个体的染色体中提取的更多。我们推测，白血病细胞DNA中CpG二核苷酸内胞嘧啶的去甲基化可以解释我们的发现。
