G protein-coupled receptor 87 (GPR87) is a newly deorphanized member of the cell surface molecule G protein-coupled receptor family. GPR signaling was shown to play a role in promotion of cell growth and survival, metastasis, and drug resistance. The overexpression of GPR87 has also been reported in many malignant tumors including bladder cancer. The aim of the present study is to examine the effect of silencing GPR87 expression with a replication-deficient recombinant adenoviral vector expressing short hairpin RNA targeting GPR87 (Ad-shGPR87) and to explore the underlying molecular mechanisms in bladder cancer cells. Six GPR87-expressing human bladder cancer cells, HT1197, HT1376, J82, RT112, TCCSUP and UMUC3, were used. Infection with Ad-shGPR87 effectively downregulated the GPR87 expression, and significantly reduced the percentage of viable cells in 4 of 6 cell lines as detected by an MTT assay. Significant inhibition on cell proliferation with Ad-shGPR87 was observed in the wild-type p53 bladder cancer cell lines (HT1197, RT112, TCCSUP and UMUC3), but not in the mutant p53 cells (HT1376 and J82). As represented by a wild-type p53 RT112 cell, Ad-shGPR87 infection significantly enhanced p53 and p21 expression and caused caspase-dependent apoptosis. Furthermore, the treatment with Ad-shGPR87 exerted a significant antitumor effect against the GPR87-expressing RT112 xenografts. GPR87 appeared to be a promising target for gene therapy, and Ad-shGPR87 had strong antitumor effects, specifically anti-proliferative and pro-apoptotic effects, against GPR87-expressing human bladder cancer cells.

RRM1—an important DNA replication/repair enzyme—is the primary molecular gemcitabine (GEM) target. High RRM1-expression associates with gemcitabine-resistance in various cancers and RRM1 inhibition may provide novel cancer treatment approaches. Our study elucidates how RRM1 inhibition affects cancer cell proliferation and influences gemcitabine-resistant bladder cancer cells. Of nine bladder cancer cell lines investigated, two RRM1 highly expressed cells, 253J and RT112, were selected for further experimentation. An RRM1-targeting shRNA was cloned into adenoviral vector, Ad-shRRM1. Gene and protein expression were investigated using real-time PCR and western blotting. Cell proliferation rate and chemotherapeutic sensitivity to GEM were assessed by MTT assay. A human tumor xenograft model was prepared by implanting RRM1 highly expressed tumors, derived from RT112 cells, in nude mice. Infection with Ad-shRRM1 effectively downregulated RRM1 expression, significantly inhibiting cell growth in both RRM1 highly expressed tumor cells. In vivo, Ad-shRRM1 treatment had pronounced antitumor effects against RRM1 highly expressed tumor xenografts (p < 0.05). Moreover, combination of Ad-shRRM1 and GEM inhibited cell proliferation in both cell lines significantly more than either treatment individually. Cancer gene therapy using anti-RRM1 shRNA has pronounced antitumor effects against RRM1 highly expressed tumors, and RRM1 inhibition specifically increases bladder cancer cell GEM-sensitivity. Ad-shRRM1/GEM combination therapy may offer new treatment options for patients with GEM-resistant bladder tumors.

The orphan GPR87 has recently been matched with its ligand LPA, which is a lipid mediator with multiple physiological functions, including cancer cell proliferation. This study aimed to clarify the role of GPR87 in urothelial carcinoma of the bladder. GPR87 expression was assessed in seven human bladder cancer cell lines. A replication-deficient recombinant adenoviral vector expressing shRNA targeting GPR87 (Ad-shGPR87), was constructed. Gene silencing was carried out using Ad-shGPR87. Immunohistochemical analysis was performed for transurethral resection of bladder tumor samples from 71 patients with non-muscle-invasive bladder cancer. We observed GPR87 expression in five of the seven cell lines, and silencing GPR87 gene expression significantly reduced cell viability. GPR87 expression was positive in 38 (54%) of 71 tumors. Ki-67 index was associated with positive GPR87 staining status (p < 0.0001). Patients with GPR87-positive tumors had shorter intravesical recurrence-free survival than those with GPR87-negative tumors (p = 0.010). Multivariate analysis revealed that GPR87 staining status was an independent prognostic parameter for intravesical recurrence (p = 0.041). Progression from non-muscle-invasive to muscle-invasive tumor was more frequently observed in patients with GPR87-positive tumors, although this trend did not reach statistical significance (p = 0.056). These results warrant further prospective studies to clarify the role of GPR87 expression in intravesical recurrence and progression in bladder cancer.

Background: Chronic inflammation is thought to be a major causative factor for the development of benign prostatic hyperplasia (BPH) and lower urinary tract symptoms (LUTS). Tadalafil, a phosphodiesterase type 5 inhibitor (PDE5-I), which has been used for the treatment of BPH-LUTS in daily practice, is known to act at several urinary organs. In this study, focused on the prostate, we examined the effect of tadalafil on the pathological changes and inflammatory factors in a rat nonbacterial prostatitis (NBP) model. Methods: Forty ten-month-old male Wistar rats were divided into nonbacterial prostatitis (NBP), NBP with tadalafil treatment (NBP-tadalafil), control, and control treated with tadalafil (control-tadalafil) groups (n = 10 per group). The NBP and NBP-tadalafil groups were castrated and then received daily subcutaneous 17β-estradiol for 30 days. The control-tadalafil and NBP-tadalafil groups were administered daily oral tadalafil for 30 days. All rats were then sacrificed and pathological changes and inflammatory factors were assessed in the prostatic tissues. Results: In the NBP group, the stroma-to-epithelium (S/E) ratio in the ventral prostate was significantly higher than in the control group (P < 0.001). In the NBP-tadalafil group, the S/E ratio was significantly lower than in the NBP group (P < 0.001). The macrophage levels and the extent of T-cell infiltration in the NBP-tadalafil group were significantly lower than in the NBP group (P < 0.005; P < 0.001, respectively). Compared with the NBP group, tissue concentrations of inflammatory cytokines, such as tumor necrosis factor-α, interleukin-8, and interleukin-1β, were significantly downregulated in the NBP-tadalafil group (P < 0.01; P < 0.05; P < 0.005, respectively). Conclusions: Tadalafil suppressed stromal predominance and showed anti-inflammatory effects in a rat NBP model in association with downregulation of inflammatory cytokines.