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BACKGROUND Androgen‐independent growth leads to progressive prostate cancer after androgen‐ablation therapy. This may be caused by altered specificity of the androgen receptor (AR), by ligand‐independent stimulation of the AR, or by paracrine growth modulation by neuropeptides secreted by neuroendocrine (NE) cells. METHODS We established and characterized the androgen‐independent FGC‐DCC from the androgen‐dependent LNCaP fast growing colony (FGC) cell line. The androgen‐independent DU‐145, FGC‐DCC, and PC‐3, and the androgen‐dependent LNCaP and PC‐346C cell lines were used to study growth modulation of gastrin‐releasing peptide (GRP), calcitonin (CT), serotonin (5‐HT), and vasoactive intestinal peptide (VIP) by 3H‐thymidine incorporation. Specificity of the growth‐modulating effects was tested with the anti‐GRP monoclonal antibody 2A11 and induction of cAMP by neuropeptides. RESULTS Androgen‐independent growth stimulation by neuropeptides was shown in DU‐145 and PC‐346C. 2A11 inhibited GRP‐induced 3H‐thymidine incorporation in DU‐145 and PC‐346C and inhibited proliferation of the FGC‐DCC and PC‐3 cell lines. With some exceptions, cAMP induction paralleled growth stimulation. Dideoxyadenosine (DDA) inhibited the GRP‐induced growth effect in DU‐145 and PC‐346C, whereas oxadiazoloquinoxaline‐1‐one (ODQ) had no effect on 3H‐thymidine incorporation. None of the neuropeptides stimulated growth of LNCaP, FGC‐DCC, or PC‐3. CONCLUSIONS GRP‐induced growth of DU‐145 and PC‐346C was specific and cAMP‐mediated. Androgen‐independent growth of FGC‐DCC cells was mainly due to an induction of Bcl‐2 expression and possibly through the activation of an autocrine and NE‐like pathway, as has been shown also for the PC‐3 cell line. Growth induction of non‐NE cells by neuropeptides could be a possible role for NE cells in clinical prostate cancer. Prostate 42:34–44, 2000. © 2000 Wiley‐Liss, Inc.

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About 5000 frozen tissue samples are collected each year by the Erasmus Medical Center tissue bank. Two percent of these samples are randomly selected annually for RNA isolation and RNA Integrity Number (RIN) measurement. A similar quality assessment was conducted during centralization of a 20-year-old tissue collection from the cancer institute, a 15-year-old liver sample archive (-80°C), and a 13-year-old clinical pathology frozen biopsy archive (Liquid Nitrogen). Samples were divided into either high-quality (RIN ≥6.5) or low-quality overall categories, or into four "fit-for-purpose" quality groups: RIN <5: not reliable for demanding downstream analysis; 5 ≤RIN <6: suitable for RT-qPCR; 6 ≤RIN <8: suitable for gene array analysis; and RIN ≥8: suitable for all downstream techniques. In general, low RIN values were correlated with fatty, fibrous, pancreatic, or necrotic tissue. When the percentage of samples with RIN ≥6.5 is higher than 90%, the tissue bank performance is adequate. The annual 2011 quality control assessment showed that 90.3% (n=93) of all samples had acceptable RIN values; 97.4% (n=39) of the cancer institute collection had RIN values above 6.5; and 88.6% (n=123) of samples from the liver sample archive collection had RIN values higher than 6.5. As the clinical pathology biopsy collection contained only 58.8% (n=24) acceptable samples, the procurement protocols used for these samples needed immediate evaluation. When the distribution of RIN values of the different collections were compared, no significant differences were found, despite differences in average storage time and temperature. According to the principle of "fit-for-purpose" distribution, the vast majority of samples are considered good enough for most downstream techniques. In conclusion, an annual tissue bank quality control procedure provides useful information on tissue sample quality and sheds light on where and if improvements need to be made.