前列腺癌神经生长因子受体TrkA/p75NTR比值与临床分期、分级的关系

Expression ratio of the nerve growth factor receptor Trk A to p75NTR correlates with the clinical stage and pathological grade of prostate cancer

目的：探讨神经生长因子（NGF）的两种受体（TrkA和p75NTR）在前列腺癌（PCa）发生、发展中的表达规律及作用机制。方法：采用免疫组化法研究62例PCa和35例良性前列腺增生（BPH）组织中TrkA及p75NTR蛋白的表达，并结合临床资料进行统计分析。结果：通过成组t检验，发现自BPH组织至低分化PCa组织（Gleason 8～10分），随着组织分化逐渐降低或临床分期逐渐增高，TrkA受体表达显著增强，p75NTR受体表达显著减低，TrkA／p75NTR比例显著增大。在BPH组织中两者比例为0．32，在Gleason评分6分的PCa组织中为0．52，在7分的组织中为1．65，而在8～10分的组织中为5．75；在pT2期组织中两者比例为0．89，在pT3a期为1．5，在pT3b期为3．75，在有淋巴结转移（pTxN1）的组织中为7．00。结论：TrkA／p75NTR比例的失调性增高，可能是前列腺细胞恶变后的基本特征之一。TrkA／p75NTR比值越高，组织分化程度越低，临床分级、分期越高，患者预后可能越差。

Objective： To investigate the expressions and action mechanisms of nerve growth factor （NGF） receptors TrkA and p75NTR in the oncogenesis and progression of prostate cancer （PCa）. Methods： Using immunohistochemistry, we detected the expressions of TrkA and p75NTR in 62 PCa and 35 benign prostatic hyperplasia （BPH） samples, and conducted statistical analysis on the basis of clinical data. Results： Independent-samples t-test showed that, along with poorer tissue differentiation or higher clinical stage of PCa, the expression of TrkA was significantly up-regulated, that of p75NTR remarkably down-regulated, and the expression ra- tio of TrkA to p75NTR markedly increased. The TrkA/p75NTR ratio was 0.32 in the BPH, 0.52 in the PCa tissue with Gleason score of 6, 1.65 in the PCa tissue with Gleason score of 7, 5.75 in the PCa tissue with Gleason score ≥8, 0.89 in the clinical stage of pT2, 1.5 in pT3a, 3.75 in pT3b, and 7.00 in pTxN1. Conclusion ： The abnormally increased expression ratio of TrkA to p75NTR might be one of the essential features of malignant transformation of prostate cells. A higher TrkA/p75NTR expression ratio may be associated with a lower tissue differentiation, a higher clinical stage or Gleason score, and therefore a poorer prognosis.