Fulzele Suniket V, Chatterjee Abhijit, Shaik Madhu Sudhan, Jackson Tanise, Ichite Nkechi, Singh Mandip
College of Pharmacy and Pharmaceutical Sciences, Florida A&M University, Tallahassee FL 32307, USA.
Anticancer Drugs. 2007 Jan;18(1):65-78. doi: 10.1097/CAD.0b013e3280101006.
15-Deoxy-Delta-prostaglandin J2 is a naturally occurring endogenous ligand for peroxisome proliferator-activated receptor-gamma. The current study was aimed to determine the mechanism of anti-proliferative effect of 15-deoxy-Delta-prostaglandin J2+docetaxel against A549 and H460 non-small-cell lung cancer cell lines and xenograft tumors. In-vitro cytotoxicity of 15-deoxy-Delta-prostaglandin J2 alone and in combination with docetaxel was studied against A549 and H460 cell lines. For in-vivo studies, female athymic nu/nu mice were xenografted with A549 and H460 tumors and treated with 15-deoxy-Delta-prostaglandin J2 (1 mg/kg/day; intraperitoneal), docetaxel (10 mg/kg; intravenous on days 14, 18 and 22) and 15-deoxy-Delta-prostaglandin J2+docetaxel. Apoptosis was measured in A549 cells and tumor tissues, following various treatments. Peroxisome proliferator-activated receptor-gamma, caspases, Bcl2 and p53 family proteins or their mRNA expressions were measured by Western blotting, reverse transcription-polymerase chain reaction and real-time polymerase chain reaction in A549 tumors. A possible role of a peroxisome proliferator-activated receptor-gamma-independent mechanism was studied in A549 cells treated with peroxisome proliferator-activated receptor-gamma antagonist, GW9662. Isobolographic analysis demonstrated synergistic interaction (combination index <1.0) between 15-deoxy-Delta-prostaglandin J2 and docetaxel against A549 and H460 cells in vitro. 15-Deoxy-Delta-prostaglandin J2+docetaxel significantly reduced the tumor volume compared with control (P<0.05), 15-deoxy-Delta-prostaglandin J2 (P<0.05) and docetaxel (P<0.05, P<0.01) in both A549 and H460 tumors. 15-Deoxy-Delta-prostaglandin J2+docetaxel showed a significant increase in apoptosis associated with inhibition of the Bcl2 and cyclin D1 expression and overexpression of caspase and p53 pathway genes. Further, enhanced expression of caspase 3 and inhibition of cyclin D1 by 15-deoxy-Delta-prostaglandin J2+docetaxel was not reversed by GW9662, thus suggesting a possible peroxisome proliferator-activated receptor-gamma-independent mechanism. In conclusion, 15-deoxy-Delta-prostaglandin J2 enhanced the anti-tumor action of docetaxel by peroxisome proliferator-activated receptor-gamma-dependent and -independent mechanisms mediated by induction of apoptosis.
15-脱氧-Δ-前列腺素J2是过氧化物酶体增殖物激活受体γ的一种天然存在的内源性配体。本研究旨在确定15-脱氧-Δ-前列腺素J2联合多西他赛对A549和H460非小细胞肺癌细胞系及异种移植肿瘤的抗增殖作用机制。研究了15-脱氧-Δ-前列腺素J2单独及与多西他赛联合对A549和H460细胞系的体外细胞毒性。对于体内研究，将雌性无胸腺裸鼠接种A549和H460肿瘤，并分别用15-脱氧-Δ-前列腺素J2（1mg/kg/天；腹腔注射）、多西他赛（10mg/kg；于第14、18和22天静脉注射）以及15-脱氧-Δ-前列腺素J2联合多西他赛进行治疗。在各种处理后，检测A549细胞和肿瘤组织中的细胞凋亡情况。通过蛋白质免疫印迹法、逆转录-聚合酶链反应和实时聚合酶链反应检测A549肿瘤中过氧化物酶体增殖物激活受体γ、半胱天冬酶、Bcl2和p53家族蛋白或其mRNA表达。在用过氧化物酶体增殖物激活受体γ拮抗剂GW9662处理的A549细胞中，研究了过氧化物酶体增殖物激活受体γ非依赖性机制的可能作用。等效线图分析表明，15-脱氧-Δ-前列腺素J2与多西他赛在体外对A549和H460细胞具有协同相互作用（联合指数<1.0）。与对照组相比，15-脱氧-Δ-前列腺素J2联合多西他赛显著降低了A549和H460肿瘤的体积（P<0.05），单独使用15-脱氧-Δ-前列腺素J2（P<0.05）和多西他赛（P<0.05，P<0.01）时也有此效果。15-脱氧-Δ-前列腺素J2联合多西他赛显示细胞凋亡显著增加，这与Bcl2和细胞周期蛋白D1表达的抑制以及半胱天冬酶和p53通路基因的过表达有关。此外，GW9662并未逆转15-脱氧-Δ-前列腺素J2联合多西他赛对caspase 3的增强表达及对细胞周期蛋白D1的抑制作用，因此提示可能存在过氧化物酶体增殖物激活受体γ非依赖性机制。总之，15-脱氧-Δ-前列腺素J2通过诱导细胞凋亡介导的过氧化物酶体增殖物激活受体γ依赖性和非依赖性机制增强了多西他赛的抗肿瘤作用。
