Boucek R J, Miracle A, Anderson M, Engelman R, Atkinson J, Dodd D A
Division of Pediatric Cardiology, Department of Pediatrics, Tampa, FL, USA.
J Mol Cell Cardiol. 1999 Aug;31(8):1435-46. doi: 10.1006/jmcc.1999.0972.
During administration of the anthracycline antitumour agents, their cardiotoxicity can progress from cardiac dysfunction to heart failure. Cardiomyopathy can also develop years after receiving anthracyclines. To determine if persistent and/or progressive anthracycline effect(s) are referable to anthracycline effects on cardiac gene expression, steady-state mRNA levels were determined 4 days (n=8), 4 weeks (n=7) and 10 weeks (n=7) after doxorubicin (DOX; 2 mg/kg IV) in a well-characterized rabbit model. Levels of mRNA for alpha -actin, beta -myosin heavy chain and the calcium pump of the sarcoplasmic reticulum (SERCA2a) in the left ventricle (LV) were determined by Northern blot hybridization and expressed relative to an 18S constitutive marker. The mRNA levels for the high molecular weight subunit (cardiac isoform) of the ryanodine receptor (RyR2), sarcolemmal calcium channel (dihydropyridine receptor; DHPR), angiotensin-converting enzyme (ACE), angiotensin II receptor (ATR) and atrial naturetic peptide prohormone (ANP) were determined by reverse transcription-polymerase chain reaction (RT-PCR) and Southern blot analysis, and expressed relative to GAPDH, a constitutive marker. Histopathologic evidence for anthracycline-induced myocardial cell injury was absent (score <1) in all hearts examined except one (score=1.1; 4 weeks post-DOX), which was considered separately. Relative mRNA levels for beta -myosin heavy chain 4 days after DOX increased 1.9-fold compared to the vehicle-treated group, but by 4 weeks levels had returned to baseline. Relative mRNA levels for DHPR were increased 1.2-fold 4 days after DOX and were persistently increased 1.9- and 2.2-fold 4 and 10 weeks after DOX, respectively. The mRNA levels for ANP were first decreased (4.5-fold) 4 days after DOX. Four weeks after DOX, ANP message levels approached Control in seven out of eight rabbits. The one rabbit with early LV histopathology 4 weeks post-DOX had increased mRNA for DHPR (2.7-fold) and ANP (80-fold). Between 4 and 10 weeks after DOX, mRNA levels for ANP increased C 16-fold: evidence for late progression. In situ hybridization with specific riboprobes localized the persistent increase in DHPR and the progressive increase in ANP to myocytes. Thus, DOX alters steady-state mRNA levels in LV that are referable to both persistent and progressive anthracycline effects on myocellular gene expression.
在蒽环类抗肿瘤药物给药期间，其心脏毒性可从心脏功能障碍发展为心力衰竭。心肌病也可在接受蒽环类药物数年之后发生。为了确定蒽环类药物的持续性和/或进行性效应是否归因于其对心脏基因表达的影响，在一个特征明确的兔模型中，于阿霉素（DOX；2mg/kg静脉注射）给药后4天（n = 8）、4周（n = 7）和10周（n = 7）测定了稳态mRNA水平。通过Northern印迹杂交法测定左心室（LV）中α-肌动蛋白、β-肌球蛋白重链和肌浆网钙泵（SERCA2a）的mRNA水平，并相对于18S组成型标记物进行表达。通过逆转录-聚合酶链反应（RT-PCR）和Southern印迹分析测定了雷诺丁受体（RyR2）的高分子量亚基（心脏异构体）、肌膜钙通道（二氢吡啶受体；DHPR）、血管紧张素转换酶（ACE）、血管紧张素II受体（ATR）和心房利钠肽原激素（ANP）的mRNA水平，并相对于组成型标记物甘油醛-3-磷酸脱氢酶（GAPDH）进行表达。除了一只心脏（评分 = 1.1；DOX给药后4周）外，在所有检查的心脏中均未发现蒽环类药物诱导的心肌细胞损伤的组织病理学证据（评分<1），该心脏单独进行了分析。DOX给药后4天，β-肌球蛋白重链的相对mRNA水平相比载体处理组增加了1.9倍，但到4周时水平已恢复至基线。DOX给药后4天，DHPR的相对mRNA水平增加了1.2倍，在DOX给药后4周和10周分别持续增加了1.9倍和2.2倍。DOX给药后4天，ANP的mRNA水平首先下降（4.5倍）。DOX给药后4周，8只兔子中有7只的ANP信息水平接近对照组。DOX给药后4周出现早期左心室组织病理学改变的那只兔子，其DHPR（2.7倍）和ANP（80倍）的mRNA增加。在DOX给药后4至10周之间，ANP的mRNA水平增加了16倍：这是晚期进展的证据。用特异性核糖探针进行原位杂交将DHPR的持续增加和ANP的进行性增加定位到心肌细胞。因此，DOX改变了左心室中的稳态mRNA水平，这归因于蒽环类药物对心肌细胞基因表达的持续性和进行性效应。
