Altered expression of cytochrome P450 mRNA during chemical-induced hepatocarcinogenesis and following partial hepatectomy.
Altered expression of cytochrome P450 mRNA during chemical-induced hepatocarcinogenesis and following partial hepatectomy.
复制标题
在化学诱导的肝癌发生期间和部分肝切除术后细胞色素 P450 mRNA 的表达发生改变。
DOI：
10.1006/taap.1994.1017
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发表时间：
1994
影响因子：
3.8
通讯作者：
Gurtoo,HL
中科院分区：
文献类型：
--
作者：
Habib,SL;Srikanth,NS;Scappaticci,FA;Faletto,MB;Maccubbin,A;Farber,E;Ghoshal,AK;Gurtoo,HL
据报道，在化学诱导的肝细胞结节和部分肝切除术（PH）后，各种细胞色素P450蛋白的水平不同程度地降低。从未处理的雄性Fischer 344大鼠中分离出部分纯化的细胞色素P450，用抗该蛋白的抗体筛选大鼠肝λZAP cDNA表达文库，我们分离到一个1.1kb的cDNA。对该cDNA进行了5′端139个碱基的序列测定，并与Gene Man DNA数据库中的序列进行比较，结果表明该序列与雄性大鼠特异性细胞色素P450（M-1，CYP 11 IC 11）的同源性为95%。用~（32）P标记的cDNA作为探针，与PH后大鼠肝、黄曲霉毒素B_1（AFB_1）诱导的大鼠肝肿瘤和二乙基亚硝胺/乙酰氨基芴/PH（DEN/AFF/PH）联合诱导的大鼠肝结节的总RNA进行RNA印迹（北方印迹）。在PH后36和72小时，mRNA水平下降> 93%。相对于相应的对照肝脏，肝结节中的mRNA水平也降低了97%，AFB 1诱导的肝肿瘤中的mRNA水平降低了57%。用识别其他细胞色素P450（P450 Ⅰ B 1/P450 Ⅱ B 2）的cDNA探针（R17）对来自肝结节和AFB 1诱导的肝肿瘤的RNA印迹进行了探测。对应于PTIB 1/PTIB 11 B2的mRNA在结节中也被抑制92%，在肿瘤中被抑制65%。这些结果清楚地表明，在肝结节和肿瘤中抑制AIIC 11和IIB 1/IIB 2与抑制转录和/或增强mRNA降解有关。
Levels of various cytochrome P450 proteins have been reported to be decreased to varying degrees in chemically induced hepatocyte nodules and following partial hepatectomy (PH). By screening a rat liver λZAP cDNA expression library with antibodies raised against a partially purified preparation of cytochrome P450 isolated from untreated male Fischer 344 rats, we have isolated a 1.1-kb cDNA. This cDNA was sequenced for 139 bases from the 5′ end of the sense strand and comparison of the resulting sequence with the sequences in Gene Man DNA data bank revealed 95% homology of the sequenced portion with male-specific rat cytochrome P450(M-1, CYP IIC11). The32P-labeled cDNA was used as a hybridization probe on RNA blots (Northern blots) prepared with total RNA from rat livers obtained post PH, from aflatoxin B1(AFB1)-induced rat liver tumors and from rat liver nodules induced with a combination of diethylnitrosamine/acetylaminofluorene/PH (DEN/AFF/PH). At 36 and 72 hr post PH, the mRNA level was decreased by >93%. Relative to the corresponding control livers, the mRNA level was also decreased by 97% in the liver nodules and by 57% in AFB1-induced liver tumors. The RNA blots derived from the liver nodules and AFB1-induced liver tumors were also probed with a cDNA probe (R17) that recognizes other cytochromes P450 (CYP IIB1/CYP 11B2). The mRNA corresponding to CYP TIB1/CYP 11B2 was also depressed 92% in the nodules and 65% in the tumors. These results clearly indicate that the depression of both CYP IIC11 and IIB1/IIB2 in the hepatic nodules and the tumors is related to the inhibition of transcription and/or enhanced degradation of the mRNA.