Mach R H, Smith C R, al-Nabulsi I, Whirrett B R, Childers S R, Wheeler K T
Department of Radiology, Bowman Gray School of Medicine, Winston-Salem, North Carolina 27157, USA.
Cancer Res. 1997 Jan 1;57(1):156-61.
sigma 1 and sigma 2 receptors have been shown to exist in a number of rodent and human tumor cell lines. Although their expression is heterogeneous and their function is unknown, sigma receptors have been proposed as potential targets for diagnostic tumor-imaging agents. In this study, the density of sigma 2 receptors in proliferative (P) and quiescent (Q) cells of the mouse mammary adenocarcinoma, line 66, was examined. Scatchard analyses of sigma 2 receptors were performed on membrane preparations of 66 P cells from 3-day cultures and 66 Q cells from 7-, 10-, and 12-day cultures. The Scatchard studies revealed that 66 P cells had approximately 10 times more sigma 2 receptors/cell than the 66 Q cells from 10-day cultures. Although > 97% of the cells were quiescent after 7 days in culture, the maximum differential in the sigma 2 expression between 66 P and 66 Q cells was not attained until these cells had been in culture for 10 days. These data suggest that ligands labeled with positron-emitting or single photon-emitting radionuclides, which selectively bind sigma 2 receptors, have the potential to noninvasively assess the proliferative status of human breast tumors.
已证明σ1和σ2受体存在于多种啮齿动物和人类肿瘤细胞系中。尽管它们的表达具有异质性且功能未知，但σ受体已被提议作为诊断性肿瘤成像剂的潜在靶点。在本研究中，检测了小鼠乳腺腺癌66系增殖（P）细胞和静止（Q）细胞中σ2受体的密度。对来自3天培养物的66个P细胞和来自7天、10天和12天培养物的66个Q细胞的膜制剂进行了σ2受体的Scatchard分析。Scatchard研究表明，66个P细胞的σ2受体/细胞数量比来自10天培养物的66个Q细胞多约10倍。尽管培养7天后>97%的细胞处于静止状态，但66个P细胞和66个Q细胞之间σ2表达的最大差异直到这些细胞培养10天后才达到。这些数据表明，用发射正电子或单光子的放射性核素标记的、选择性结合σ2受体的配体，有可能非侵入性地评估人类乳腺肿瘤的增殖状态。
