Gokhale Prafulla C, Zhang Chuanbo, Newsome Joseph T, Pei Jin, Ahmad Imran, Rahman Aquilur, Dritschilo Anatoly, Kasid Usha N
Department of Radiation Medicine, Lombardi Cancer Center, Georgetown University Medical Center, Washington, DC 20057, USA.
Clin Cancer Res. 2002 Nov;8(11):3611-21.
Raf-1 protein serine threonine kinase plays an important role in cell survival and proliferation. Antisense inhibition of Raf-1 expression has been shown to enhance the cytotoxic effects of radiation and anticancer drugs. Here we have evaluated the toxicity, pharmacokinetics, and antitumor efficacy of a novel formulation of liposome-entrapped raf antisense oligodeoxyribonucleotide (LErafAON). The LErafAON preparation showed high liposome entrapment efficiency of rafAON (>85%) and stability at room temperature. In CD2F1 mice, administration of LErafAON produced no morbidity/mortality (5-35 mg/kg/dose, i.v., x12). Dose-related elevations in liver enzymes (alanine aminotransferase and aspartate aminotransferase) and histopathological changes in liver were noted in LErafAON and blank liposome groups. No morbidity/mortality and changes in clinical chemistry or histopathology were observed in New Zealand white rabbits (3.75 mg/kg/dose, i.v., x8; 6.5 mg/kg/dose, i.v., x6) or in cynomolgous monkeys (3.75 or 6.25 mg/kg/dose, i.v., x9). Transient decrease in total hemolytic complement activity (approximately 62-74%) and increases in C3a (approximately 3-fold) and Bb levels (approximately 5-12-fold) were observed in LErafAON and blank liposome groups of monkeys. A 30 mg/kg i.v. dose of LErafAON in human prostate tumor (PC-3)-bearing BALB/c athymic mice gave a terminal plasma half-life of 27 h, and intact rafAON could be detected in plasma and in normal and tumor tissues for up to at least 48 h. In monkeys, the terminal plasma half-life of 30.36 +/- 23.87 h was observed at an i.v. dose of 6.25 mg/kg. LErafAON (25 mg/kg/dose, i.v., x10) or ionizing radiation (3.8 Gy/day, x5) treatment of PC-3 tumor-bearing athymic mice led to tumor growth arrest, whereas a combination of LErafAON and ionizing radiation treatments resulted in tumor regression. LErafAON treatment caused inhibition of Raf-1 protein expression in normal and tumor tissues in these mice (>50%, versus controls). These data have formed a basis of the clinical Phase I studies of LErafAON for cancer treatment.
Raf-1蛋白丝氨酸苏氨酸激酶在细胞存活和增殖中起重要作用。Raf-1表达的反义抑制已被证明可增强辐射和抗癌药物的细胞毒性作用。在此，我们评估了一种新型脂质体包裹的raf反义寡脱氧核苷酸（LErafAON）制剂的毒性、药代动力学和抗肿瘤疗效。LErafAON制剂显示rafAON的脂质体包封效率高（>85%）且在室温下稳定。在CD2F1小鼠中，给予LErafAON未产生发病/死亡（5 - 35 mg/kg/剂量，静脉注射，共12次）。在LErafAON组和空白脂质体组中观察到肝酶（丙氨酸氨基转移酶和天冬氨酸氨基转移酶）的剂量相关升高以及肝脏的组织病理学变化。在新西兰白兔（3.75 mg/kg/剂量，静脉注射，共8次；6.5 mg/kg/剂量，静脉注射，共6次）或食蟹猴（3.75或6.25 mg/kg/剂量，静脉注射，共9次）中未观察到发病/死亡以及临床化学或组织病理学的变化。在食蟹猴的LErafAON组和空白脂质体组中观察到总溶血补体活性短暂降低（约62 - 74%）以及C3a水平升高（约3倍）和Bb水平升高（约5 - 12倍）。在携带人前列腺肿瘤（PC - 3）的BALB/c无胸腺小鼠中静脉注射30 mg/kg剂量的LErafAON，其血浆终末半衰期为27小时，并且在血浆以及正常和肿瘤组织中至少48小时内均可检测到完整的rafAON。在食蟹猴中，静脉注射6.25 mg/kg剂量时观察到血浆终末半衰期为30.36±23.87小时。对携带PC - 3肿瘤的无胸腺小鼠进行LErafAON（25 mg/kg/剂量，静脉注射，共10次）或电离辐射（3.8 Gy/天，共5次）治疗导致肿瘤生长停滞，而LErafAON与电离辐射联合治疗导致肿瘤消退。LErafAON治疗导致这些小鼠的正常和肿瘤组织中Raf-1蛋白表达受到抑制（>50%，与对照组相比）。这些数据构成了LErafAON用于癌症治疗的临床I期研究的基础。
