Analysis of stromal cell factors influencing the growth of prostatic cancer and benign prostatic hyperplasia

人前列腺癌雄激素非依赖性细胞系PC 93可移植到裸鼠体内。当与前列腺或骨髓来源的成纤维细胞同时移植时，PC 93的体内生长加速。正常前列腺源性成纤维细胞的培养上清液显示对PC 93的生长促进作用。在已知的生长因子中，aFGF、bFGF、EGF和TGF α具有促生长作用。使用RT-PCR对各种已知的生长因子，在成纤维细胞中仅检测到bFGF mRNA。将中和抗体添加到生长因子如bFGF、EGF及其组合中并不能完全抑制促生长作用。这些结果表明存在尚未鉴定的生长因子。我们试图纯化这种生长因子的基础上，在体外接触非依赖性的生长促进作用的PC 93。用肝素柱层析进行分级显示，未吸附的级分、0.5M和1.0M NaCl洗脱的级分具有这种活性。0.5M NaCl洗脱的组分具有最高的比活性。凝胶色谱进行0.5M NaCl洗脱馏分鉴定约。32 KDa蛋白，这是从以前已知的前列腺癌生长因子不同。然而，这三种组分中哪一种对于体内生长促进是重要的，还有待确定。

PC93, an androgen-independent cell line derived from human prostatic cancer, is transplantable to nude mouse. In vivo growth of PC93 is accelerated when transplamted simultaneously with prostate-or bone marrow-derived fibroblasts. Culture supernatant of normal prostate-derived fibroblasts showed the growth-promoting effect on PC93. Among the known growth factors, aFGF,bFGF,EGF and TGFalpha possessed the growth-promoting effect. Only bFGF mRNA was detected in fibroblasts using RT-PCR for various known growth factors. The growth-promoting effect was not completely inhibited by addition of the neutralizing autibodies to the growth factors such as bFGF,EGF and their combination. These results suggested the presence of the growth factor (s) not yet identified. We attempted attempted to purify this growth factor on the basis of in vitro contact-independent growth-promoting effect on PC93. Fractionation using heparin column chromatography showed that the unadsorbed fraction, the 0.5M and 1.0M NaCl-eluted fractions had such activity. The 0.5M NaCl-eluted fraction had highest specific acitivity. Gel chromatography performed on the 0.5M NaCl-eluted fraction identified ca.32KDa protein, which was different from previously known growth factors for prostatic cancer. It remains to be determined, however, which of the three fractions is important for in vivo growth promotion.