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

PC93是一种来源于人前列腺癌的雄激素非依赖性细胞系，可移植到裸鼠体内。在体内，当PC93与前列腺或骨髓来源的成纤维细胞同时移植时，生长速度会加快。正常前列腺成纤维细胞培养上清对PC93有促生长作用。在已知的生长因子中，aFGF4、bFGF3、EGF和TGFα具有促生长作用。RT-PCR检测到多种已知生长因子在成纤维细胞中仅检测到bFGFm RNA。在生长因子bFGF、EGF及其组合中加入中和抗体不能完全抑制其促生长作用。这些结果表明，生长因子(S)的存在尚未确定。我们试图在PC93的体外非接触性促生长作用的基础上纯化这种生长因子。肝素柱层析分离表明，未吸附部分、0.5M和1.0M氯化钠洗脱部分具有这种活性。0.5M氯化钠洗脱部分比活性最高。对0.5M的氯化钠洗脱部分进行凝胶层析，鉴定出约32 KDa的蛋白质，这与先前已知的前列腺癌生长因子不同。然而，这三个组分中的哪一个对于促进体内生长是重要的，这还有待确定。

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.