The expression and localisation of beta-nerve growth factor (beta-NGF) in benign and malignant human prostate tissue: relationship to neuroendocrine differentiation.

beta-NGF is a determinant of sympathetic innervation and a neural differentiation factor. In the present study, we have examined 15 benign prostatic hyperplastic and 15 prostate cancer patients for the expression and localisation of beta-NGF by reverse transcription-polymerase chain reaction (RT-PCR), Western blotting, immunohistochemistry and ELISA. We have correlated the beta-NGF concentrations to prostate morphometry and neuroendocrine differentiation. The presence of beta NGF mRNA transcripts was confirmed by RT-PCR where a 542 bp product was found with specific primers for the human beta-NGF cDNA sequence. The presence of the peptide was also confirmed by Western blot analysis which showed a protein co-migrating with recombinant human beta-NGF. Our results demonstrate that beta-NGF is localised to prostate epithelium, and the concentrations of the peptide were not significantly different in malignant (mean +/- s.d.; 3100 +/- 1502 pg g-1 wet weight of tissue) than in benign tissues (1992 +/- 684 pg g-1, P = 0.512). We were, however, unable to correlate the concentrations of beta-NGF to neuroendocrine differentiation in malignant tissues. Clearly, the present study demonstrates that beta-NGF is a product of the prostate and may be involved in the control of the sympathetic innervation of the human prostate.