Department of Neural and Behavioral Sciences, College of Medicine, The Pennsylvania State University, 500 University Drive, Hershey, PA 17033-0850, USA.
Exp Biol Med (Maywood). 2012 Feb;237(2):167-77. doi: 10.1258/ebm.2011.011321. Epub 2012 Feb 10.
The opioid growth factor (OGF) and its receptor, OGFr, serve as a tonically active inhibitory axis regulating the proliferation of human ovarian cancer cells. In the present study, we have investigated the repercussion on the progression of this deadly neoplasia when cells are engineered to molecularly under-express OGFr. shRNA constructs were used to knockdown OGFr in SKOV-3 cells; two clonal cell lines were examined. OGFr protein expression was decreased up to 73% in clones compared with wild-type (WT) and empty vector (EV) controls. OGFr-binding assays of clones revealed 50-55% decreases in binding capacity compared with control cells; binding affinity was comparable in all groups. Cell number in clones was increased 33-132%, and doubling times decreased 29-35%, compared with WT and EV cultures. Addition of exogenous OGF or naltrexone did not affect cell number in cultures with silenced OGFr. DNA synthesis of clonal cell lines was increased 136-146% from the WT and EV groups; no changes were noted in cell survival. Nude mice injected subcutaneously with cells under-expressing OGFr had an increased tumor incidence, decreased latency to tumor formation, increased tumor volume and decreased OGFr expression in tumors compared with WT and EV controls. OGF treatment in mice with WT or EV tumors, but not OGFr under-expressing tumors, inhibited tumor volume and weight. Collectively, these data demonstrate the critical nature of the OGF-OGFr axis as a determinant of the progression of human ovarian cancer, and suggest that attenuation of this system has an important bearing on the survival of these patients.
阿片样物质生长因子 (OGF) 及其受体 OGFr 作为一个持续活跃的抑制轴，调节人卵巢癌细胞的增殖。在本研究中，我们研究了当细胞被设计为分子低表达 OGFr 时，对这种致命肿瘤进展的影响。shRNA 构建体用于敲低 SKOV-3 细胞中的 OGFr；检查了两个克隆细胞系。与野生型 (WT) 和空载体 (EV) 对照相比，克隆中 OGFr 蛋白表达降低了高达 73%。克隆的 OGFr 结合测定显示与对照细胞相比，结合能力降低了 50-55%；所有组的结合亲和力相当。与 WT 和 EV 培养物相比，克隆中的细胞数量增加了 33-132%，倍增时间减少了 29-35%。在沉默 OGFr 的培养物中添加外源性 OGF 或纳曲酮不会影响细胞数量。克隆细胞系的 DNA 合成增加了 WT 和 EV 组的 136-146%；细胞存活率没有变化。与 WT 和 EV 对照相比，皮下注射低表达 OGFr 的细胞的裸鼠肿瘤发生率增加，肿瘤形成潜伏期缩短，肿瘤体积增加，肿瘤中 OGFr 表达降低。在 WT 或 EV 肿瘤小鼠中给予 OGF 治疗，但在低表达 OGFr 的肿瘤小鼠中没有，可抑制肿瘤体积和重量。总的来说，这些数据表明 OGF-OGFr 轴作为人卵巢癌进展的决定因素具有重要意义，并表明该系统的衰减对这些患者的生存有重要影响。
