Nuclear expression of Lyn, a Src family kinase member, is associated with poor prognosis in renal cancer patients.

BACKGROUND: 8000 cases of renal cancer are diagnosed each year in the UK, with a five-year survival rate of 50%. Treatment options are limited; a potential therapeutic target is the Src family kinases (SFKs). SFKs have roles in multiple oncogenic processes and promote metastases in solid tumours. The aim of this study was to investigate SFKs as potential therapeutic targets for clear cell renal cell carcinoma (ccRCC). METHODS: SFKs expression was assessed in a tissue microarray consisting of 192 ccRCC patients with full clinical follow-up. SFK inhibitors, dasatinib and saracatinib, were assessed in early ccRCC cell lines, 786-O and 769-P and a metastatic ccRCC cell line, ACHN (± Src) for effects on protein expression, apoptosis, proliferation and wound healing. RESULTS: High nuclear expression of Lyn and the downstream marker of activation, paxillin, were associated with decreased patient survival. Conversely, high cytoplasmic expression of other SFK members and downstream marker of activation, focal adhesion kinase (FAK) were associated with increased patient survival. Treatment of non-metastatic 786-O and 769-P cells with dasatinib, dose dependently reduced SFK activation, shown via SFK (Y(419)) and FAK (Y(861)) phosphorylation, with no effect in metastatic ACHN cells. Dasatinib also increased apoptosis, while decreasing proliferation and migration in 786-O and 769-P cell lines, both in the presence and absence of Src protein. CONCLUSIONS: Our data suggests that nuclear Lyn is a potential therapeutic target for ccRCC and dasatinib affects cellular functions associated with cancer progression via a Src kinase independent mechanism.

Real world outcomes of biopsy-proven oncocytic neoplasm of the kidney managed by surveillance.

Objectives: To evaluate outcomes of patients diagnosed with oncocytic renal neoplasms on routine renal mass biopsy and to describe the natural history of these tumours when managed with surveillance as opposed to immediate intervention. To report disease-specific survival. Patients and methods: Patients were identified from a retrospective review of pathology databases from three tertiary referral centres that utilise renal mass biopsy in routine clinical practice. All patients with biopsy-proven oncocytic tumours were included and a retrospective review of online patient records was undertaken. Results: There were 184 biopsy-proven oncocytic renal neoplasms identified in 172 patients. There were two biopsy complications (both pneumothorax, Clavien-Dindo Grade I). Of these lesions, 135 were reported as oncocytomas or oncocytic renal neoplasms that were not further classified and 37 were reported as chromophobe carcinoma (ChRCC). The median age at diagnosis was 70 (33-88). The average tumour diameter at diagnosis was 33 mm. One hundred seven tumours were initially managed with surveillance (including 13 ChRCC) with a minimum follow-up of 6 months and a median of 39 months (6-144) whereas 49 patients underwent immediate treatment. The mean growth rate across all oncocytic renal neoplasms managed by surveillance was 3 mm/year. There was no statistically significant difference in growth rates between oncocytic renal neoplasms and ChRCC. Thirteen patients with oncocytic renal neoplasms initially managed by surveillance moved on to an active management strategy during follow-up. The clinical indication given for a change from surveillance was tumour growth in 12 cases and patient choice in 1 case. Where definitive pathology was available, there was 85% concordance with the biopsy. There were no cases of development of metastatic disease or disease-related morbidity or mortality during the study. Conclusions: This multicentre retrospective cohort study supports the hypothesis that selected biopsy-proven oncocytic renal neoplasms can be safely managed with surveillance in the medium term. Routine renal mass biopsy may reduce surgery for benign or indolent renal tumours and the potential associated morbidity for these patients.

Does surgery have a role in management of chronic intrascrotal pain?

OBJECTIVES: To assess the role of epididymectomy in the treatment of chronic postvasectomy and epididymal pain syndrome and to identify the factors that predict the outcome. METHODS: A total of 38 patients, aged 20 to 70 years (mean 45), who had undergone epididymectomy for intractable intrascrotal pain, were identified retrospectively from the pathology records. The clinical notes were reviewed, and details on patient demographics, previous vasectomy, investigations, and histologic features were collected and analyzed. The outcome was assessed by routine outpatient clinic review and telephone interview. RESULTS: Overall, 32% of patients reported resolution of symptoms after epididymectomy; 17 patients had undergone previous vasectomy, and this group was significantly more likely to have ongoing pain. Abnormal examination and ultrasound findings preoperatively did not correlate with a better outcome from surgery. CONCLUSIONS: The results of our study have shown that epididymectomy has a limited role in the management of chronic intrascrotal pain.

Zoledronic acid induces apoptosis and inhibits adhesion to mineralized matrix in prostate cancer cells via inhibition of protein prenylation.

OBJECTIVE: To investigate effects of zoledronic acid on apoptosis and adhesion to mineralized matrix in prostate cancer cells, to quantify these actions, and to elucidate some of the underlying molecular mechanisms, in terms of dependence on caspase activation and involvement of protein prenylation. MATERIALS AND METHODS: DU145 and PC-3 prostate cancer cell lines were used; cells were treated with zoledronic acid, with or without several other reagents, to investigate its mechanism of action. Apoptosis was detected using a cell-death detection enzyme-linked immunosorbent assay. Adhesion was measured by seeding cells onto mineralized dentine inserts for 24 h, and counting cells after washing. RESULTS: Apoptosis depended on time and dose; there was significant apoptosis with higher concentrations of zoledronic acid (100 micromol/L) after 24 h of exposure, and in DU145 cells with concentrations as low as 1 micromol/L after 72 h of exposure. The apoptotic effect was diminished by co-treating with a broad-spectrum caspase inhibitor, Z-VAD-FMK. Zoledronic acid at 1 micromol/L also significantly inhibited cell adhesion to the mineralized matrix. The lipid isoprenoid analogue geranylgeraniol reduced the apoptotic and anti-adhesive effects of zoledronic acid to a greater degree than farnesol. There was also apoptosis and inhibition of adhesion with direct inhibitors of prenylation, e.g. manumycin A and GGTI-298. C3 exoenzyme, an inhibitor of RhoA, inhibited adhesion but did not cause apoptosis. CONCLUSION: Zoledronic acid induces apoptosis in prostate cancer cells via a caspase-dependent mechanism, and at concentrations as low as 1 micromol/L it also inhibits adhesion of cells to mineralized matrix. These effects appear to be exerted via inhibiting G-protein prenylation and in particular geranylgeranylation.

Nitrogen containing bisphosphonates induce apoptosis and inhibit the mevalonate pathway, impairing Ras membrane localization in prostate cancer cells.

PURPOSE: Metastasis to bone is an important cause of morbidity in advanced prostate cancer. Despite the typically sclerotic nature of prostatic bone metastases osteolysis has a significant role in the pathogenesis of this disease. The nitrogen containing bisphosphonates (N-BPs), such as pamidronate and zoledronic acid, have greatly enhanced potency for inhibiting bone resorption and inducing apoptosis in osteoclasts. We investigated the effects of N-BPs on prostate cancer cells. MATERIALS AND METHODS: Cell viability was determined with an MTS (3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymeyhoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium) dye reduction assay. Cell cycle analysis, DNA fragmentation and caspase 3 activity were assessed using flow cytometry. Ras, Bcl-2 and Bax were quantified by Western blotting. RESULTS: Pamidronate and zoledronic acid decreased cell viability in the 3 human cell lines DU145, PC3 and LNCaP. These effects were associated with changes in cell cycle distribution, induction of DNA fragmentation and a decrease in the Bcl-2-to-Bax ratio, which are features of apoptotic cell death. Pre-incubation with caspase inhibitors attenuated the effects of zoledronic acid and caspase 3 activity was demonstrated in treated DU145 cells. Zoledronic acid induced loss of cell viability in DU145 cells was prevented by co-treatment with farnesol, suggesting that N-BPs cause inhibition of the mevalonate pathway and Ras prenylation. A decrease in active, membrane bound Ras in zoledronic acid treated DU145 cells was shown by Western blot analysis. CONCLUSIONS: N-BPs induce apoptosis in prostate cancer via a caspase dependent mechanism. They have effects on protein prenylation via inhibition of the mevalonate pathway and impair membrane localization of Ras in prostate cancer cells.