表皮生长因子对游离细胞核特异基因体外转录的影响

ＥＧＦ作用于ＮＣ３Ｈ１０和ＴＣ３Ｈ１０细胞核，对ＲＮＡ聚合酶Ⅱ有促进作用，但对ＲＮＡ聚合酶Ⅰ和酶Ⅲ没有影响，此外还发现转化细胞核内的ＲＮＡ聚合酶Ⅰ和酶Ⅱ的活性比正常细胞高１倍多。但两种细胞的ＲＮＡ聚合酶Ⅱ差别不大。同时，以非放射性标记的ｃ－ｆｏｓ、ＣＬＮ１、ＣＬＮ３探针进行点杂交，结果发现，ＥＧＦ直接作用于细胞核可使ｃ－ｆｏｓ、ＣＬＮ１基因的转录水平提高；但是，对ＣＬＮ３无影响。

Study on the Nuclear Effects of Epidermal Growth Factor

EGF was used to stimulate purified C3H10 T1/2 Cl 8 and its transformed countpart cell nuclei it was found that EGF could promote the activity of RNA polymerase Ⅱ in NC3H10 and TC3H10 nuclei, but it could not promote the activity of RNA polymerase Ⅲ and polymerase Ⅰ in those two cell nuclei. Furthermore, the levels of RNA polymerase Ⅰ and Ⅲ in TC3H10 cell increased one-fold relative to levels in NC3H10 nuclei. By contrast, the levels of RNA polymerase Ⅱ were invariant. In addition, the expression of c-fos gene and CLN1 gene in NC3H10 nuclei were analysed by nuclear RNA dot blotting using non-radioactive lablled c-fos, CLN1 and CLN3 probes. The results indicated that the expression of c-fos and CLN1 increased after NC3H10 nuclei were stimulated with EGF, but CLN3 did not.