Toshiyuki Kamoto

Antiandrogen bicalutamide promotes tumor growth in a novel androgen-dependent prostate cancer xenograft model derived from a bicalutamide-treated patient.

Androgen ablation therapies are effective in controlling prostate cancer. Although most cancers relapse and progress despite androgen ablation, some patients experience antiandrogen withdrawal syndrome, in which those treated with antiandrogen show clinical improvement when antiandrogen is discontinued. Although the androgen receptor (AR) is suggested to play an important role in prostate cancer progression even after the androgen ablation, limited tissue availability for molecular studies and small numbers of human prostate cancer cell lines have restricted prostate cancer research. Here, we describe KUCaP, a novel serially transplantable human prostate cancer xenograft model. We established KUCaP from liver metastatic tissue of a patient treated with antiandrogen bicalutamide. KUCaP expressed the AR with a point mutation at amino acid 741 (tryptophan to cysteine; W741C) in the ligand-binding domain. This mutation was also present in cancerous tissue used for generation of KUCaP. Although the growth of KUCaP in male mice was androgen dependent, bicalutamide aberrantly promoted the growth and prostate-specific antigen production of KUCaP. For the first time, we show the agonistic effect of bicalutamide to a xenograft with clinically induced AR mutation. This bicalutamide-responsive mutant AR will serve in the development of new therapies for androgen ablation-resistant prostate cancers.

Increased risk of prostate cancer associated with AA genotype of cyclin D1 gene A870G polymorphism

CCND1 mRNA is alternatively spliced to produce 2 transcripts, and the splicing pattern may be modulated by a frequent A870G single‐nucleotide polymorphism within the conserved splice donor site of exon 4. Several studies have suggested a significant association between the CCND1 genotype and onset or progression of various cancers. To investigate the correlation of the polymorphism with genetic susceptibility to PCa and its disease status, we examined the polymorphism in 214 cases of PCa, 234 cases of BPH and 254 male controls. The CCND1 A allele was more frequently observed in the PCa group (p = 0.015) and the BPH group (p = 0.018) than the control group. Men with the AA genotype had an increased risk of PCa (aOR = 1.93, 95% CI 1.13–3.30, p = 0.016) and BPH (aOR = 1.84, 95% CI 1.09–3.09, p = 0.023) compared to those with the GG genotype. No significant association was observed when men with the AG genotype were compared to those with the GG genotype (PCa: aOR = 1.00, 95% CI 0.65–1.54, BPH: aOR = 0.91, 95% CI 0.60–1.39). The risk of PCa associated with the AA genotype appeared to be stronger in men aged 73 years or younger (aOR = 2.89, 95% CI 1.38–6.01, p = 0.005), whereas no association was found in men older than 73 years (aOR = 1.02, 95% CI 0.44–2.34). No significant difference in genotype frequency was found among patients with low‐, intermediate‐ and high‐grade tumors (p = 0.730) or between patients with localized and metastatic PCa (p = 0.679). However, in patients with high‐grade or metastatic PCa, a significantly increased risk associated with the AA genotype compared to controls was observed, while no significant results were found in those with low/intermediate or localized PCa. The A allele of the CCND1 A870G polymorphism was recessively associated with susceptibility to PCa and BPH in a Japanese population, giving a 2‐fold increased risk of PCa and BPH in men with the AA genotype compared to those with the GG genotype. Although the risk of PCa associated with the AA genotype appeared to contribute especially to men aged 73 years or younger and the A allele may be associated with disease status of PCa, these conjectures require validation in future studies on a larger number of subjects.

Secreted CXCL1 Is a Potential Mediator and Marker of the Tumor Invasion of Bladder Cancer

Purpose: The purpose of this study was to identify proteins that are potentially involved in the tumor invasion of bladder cancer. Experimental Design: We searched for the candidate proteins by comparing the profiles of secreted proteins among the poorly invasive human bladder carcinoma cell line RT112 and the highly invasive cell line T24. The proteins isolated from cell culture supernatants were identified by shotgun proteomics. We found that CXCL1 is related to the tumor invasion of bladder cancer cells. We also evaluated whether the amount of the chemokine CXCL1 in the urine would be a potential marker for predicting the existence of invasive bladder tumors. Results: Higher amount of CXCL1 was secreted from highly invasive bladder carcinoma cell lines and this chemokine modulated the invasive ability of those cells in vitro. It was revealed that CXCL1 regulated the expression of matrix metalloproteinase-13 in vitro and higher expression of CXCL1 was associated with higher pathologic stages in bladder cancer in vivo. We also showed that urinary CXCL1 levels were significantly higher in patients with invasive bladder cancer (pT1-4) than those with noninvasive pTa tumors (P = 0.0028) and normal control (P < 0.0001). Finally, it was shown that CXCL1 was an independent factor for predicting the bladder cancer with invasive phenotype. Conclusions: Our results suggest that CXCL1 modulates the invasive abilities of bladder cancer cells and this chemokine may be a potential candidate of urinary biomarker for invasive bladder cancer and a possible therapeutic target for preventing tumor invasion.

Impact of IGF-I and CYP19 Gene Polymorphisms on the Survival of Patients With Metastatic Prostate Cancer

PURPOSE The prognosis of metastatic prostate cancer significantly differs among individuals. While various clinical and biochemical prognostic factors for survival have been suggested, the progression and response to treatment of those patients may also be defined by host genetic factors. In this study, we evaluated genetic polymorphisms as prognostic predictors of metastatic prostate cancer. PATIENTS AND METHODS One hundred eleven prostate cancer patients with bone metastasis at the diagnosis were enrolled in this study. Thirteen genetic polymorphisms were genotyped using polymerase chain reaction-restriction fragment length polymorphism or an automated sequencer with a genotyping software. RESULTS Among the polymorphisms, the long allele (over 18 [CA] repeats) of insulin-like growth factor-I (IGF-I) and the long allele (over seven [TTTA] repeats) of cytochrome P450 (CYP) 19 were significantly associated with a worse cancer-specific survival (P = .016 and .025 by logrank test, respectively). The presence of the long allele of either the IGF-I or CYP19 polymorphisms was an independent risk factor for death (P = .019 or .026, respectively). Furthermore, the presence of the long allele of both the IGF-I and CYP19 polymorphisms was a stronger predictor for survival (P = .001). CONCLUSION The prognosis of metastatic prostate cancer patients is suggested to be influenced by intrinsic genetic factors. The IGF-I (CA) repeat and CYP19 (TTTA) repeat polymorphisms may be novel predictors in prostate cancer patients with bone metastasis at the diagnosis.

Development of Japanese version of the UCLA Prostate Cancer Index: a pilot validation study

Abstract.Methods: The Japanese version (version 1.2) of the UCLA PCI was developed through a process of translation, back-translation, and refinement after interviewing patients. Reliability and validity were examined for 125 Japanese patients with localized prostate cancer. The patients simultaneously responded to the Japanese version of the RAND 36-Item Health Survey (SF-36) and five representative questions from the International Index of Erectile Function (IIEF). Results: Internal consistency reliability was very high for both urinary and sexual function scales, and lower for bowel function. The test-retest reliability of the urinary and sexual function scales and the urinary bother scales was stable, while that of the bowel function and bother scales was relatively unstable. Sexual function scores did not correlate highly with sexual bother scores. Furthermore, poor sexual function and bother had little association with the SF-36 scores. Missing data as to urinary and bowel function/bother scales were minimal (0.8%–2.4%), while those for sexual function and bother were relatively high (4.8%–11.2%). Conclusions: The results of this pilot study, together with the previous American study, suggest ethnic or cultural difference in how impaired sexual function is integrated into overall QOL. A future cross-cultural comparative study using the UCLA PCI and SF-36 will provide useful information about the influence of cultural or ethnic differences on health-related QOL in prostate cancer patients.

Evaluation of Narrow-Band Imaging as a Complementary Method for the Detection of Bladder Cancer

PURPOSE We evaluated the use of narrow-band imaging (NBI) cystoscopy for the detection of bladder cancer and analyzed its diagnostic efficacy in cases of carcinoma in situ (CIS) and in cases with known urine cytology results. PATIENTS AND METHODS A prospective controlled study of NBI was conducted in 104 consecutive patients with definite or suspected bladder cancer. Transurethral targeted biopsies were performed after white light imaging (WLI) and NBI cystoscopy, and the histologic outcomes were compared. RESULTS A total of 313 biopsies were taken, including 161 from sites identified as potentially abnormal by NBI and/or WLI cystoscopy, and 152 from apparently normal sites. The percentage of malignancies in the sites identified only by NBI was 55.7% (39/70 places). In 26.9% of patients (28/104), bladder tumors were detected only by NBI. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and likelihood ratio of a negative test (NLR) for the detection of bladder tumors using NBI in all patients were 92.7%, 70.9%, 63.4%, 94.7%, and 0.10, respectively. The sensitivity, specificity, PPV, NPV, and NLR for the detection of CIS using NBI were 89.7%, 74.5%, 78.8%, 87.2%, and 0.14, respectively. The sensitivity, specificity, PPV, NPV, and NLR for the detection of bladder tumors using NBI in patients with positive vs negative urine cytology were 85.4% vs 98.4%, 75.7% vs 66.3%, 61.2% vs 64.5%, 92.0% vs 98.5%, and 0.19 vs 0.02, respectively. CONCLUSIONS NBI is a simple and effective method for identifying bladder tumors including CIS without the need for dyes because of its high sensitivity, high NPV, and low NLR.

Identification of EP4 as a Potential Target for the Treatment of Castration-Resistant Prostate Cancer Using a Novel Xenograft Model

More effective therapeutic approaches for castration-resistant prostate cancer (CRPC) are urgently needed, thus reinforcing the need to understand how prostate tumors progress to castration resistance. We have established a novel mouse xenograft model of prostate cancer, KUCaP-2, which expresses the wild-type androgen receptor (AR) and which produces the prostate-specific antigen (PSA). In this model, tumors regress soon after castration, but then reproducibly restore their ability to proliferate after 1 to 2 months without AR mutation, mimicking the clinical behavior of CRPC. In the present study, we used this model to identify novel therapeutic targets for CRPC. Evaluating tumor tissues at various stages by gene expression profiling, we discovered that the prostaglandin E receptor EP4 subtype (EP4) was significantly upregulated during progression to castration resistance. Immunohistochemical results of human prostate cancer tissues confirmed that EP4 expression was higher in CRPC compared with hormone-naïve prostate cancer. Ectopic overexpression of EP4 in LNCaP cells (LNCaP-EP4 cells) drove proliferation and PSA production in the absence of androgen supplementation in vitro and in vivo. Androgen-independent proliferation of LNCaP-EP4 cells was suppressed when AR expression was attenuated by RNA interference. Treatment of LNCaP-EP4 cells with a specific EP4 antagonist, ONO-AE3-208, decreased intracellular cyclic AMP levels, suppressed PSA production in vitro, and inhibited castration-resistant growth of LNCaP-EP4 or KUCaP-2 tumors in vivo. Our findings reveal that EP4 overexpression, via AR activation, supports an important mechanism for castration-resistant progression of prostate cancer. Furthermore, they prompt further evaluation of EP4 antagonists as a novel therapeutic modality to treat CRPC.

Microarray-based identification of CUB-domain containing protein 1 as a potential prognostic marker in conventional renal cell carcinoma.

PurposeRenal cell carcinoma (RCC) is characterized by a variable and unpredictable clinical course. Thus, accurate prediction of the prognosis is important in clinical settings. We conducted microarray-based study to identify a novel prognostic marker in conventional RCC.Patients and methodsThe present study included the patients surgically treated at Kyoto University Hospital. Gene expression profiling of 39 samples was carried out to select candidate prognostic markers. Quantitative real-time PCR of 65 samples confirmed the microarray experiment results. Finally, we evaluated the significance of potential markers at their protein expression level by immunohistochemically analyzing 230 conventional RCC patients.ResultsUsing expression profiling analysis, we identified 14 candidate genes whose expression levels predicted unfavorable disease-specific survival. Next, we examined the expression levels of nine candidate genes by quantitative real-time PCR and selected CUB-domain containing protein 1 (CDCP1) for further immunohistochemical analysis. Positive staining for CDCP1 inversely correlated with disease-specific and recurrence-free survivals. In multivariate analysis including clinical/pathological factors, CDCP1 staining was a significant predictor of disease-specific and recurrence-free survivals.ConclusionsWe identified CDCP1 as a potential prognostic marker for conventional RCC. Further studies might be required to confirm the prognostic value of CDCP1 and to understand its function in RCC progression.

Opioid Rotation from Oral Morphine to Oral Oxycodone in Cancer Patients with Intolerable Adverse Effects: An Open-Label Trial

OBJECTIVE We prospectively investigated the efficacy of opioid rotation from oral morphine to oral oxycodone in cancer patients who had difficulty in continuing oral morphine treatment because of inadequate analgesia and/or intolerable side effects. METHODS Twenty-seven patients were enrolled and 25 were evaluated. The rate of patients who achieved adequate pain control, which provided an indication of treatment success, was evaluated as primary endpoint. The acceptability and pharmacokinetics of oxycodone were evaluated in addition to the assessment of analgesic efficacy and safety during the study period. RESULTS In spite of intense pain, the morphine daily dose could not be increased in most patients before the study because of intolerable side effects. However, switching to oral oxycodone allowed approximately 1.7-fold increase as morphine equivalent dose. Consequently, 84.0% (21/25) of patients achieved adequate pain control. By the end of the study, all patients except one had tolerated the morphine-induced intolerable side effects (i.e. nausea, vomiting, constipation, drowsiness). Common side effects (>10%) that occurred during the study were typically known for strong opioid analgesics, and most were mild to moderate in severity. A significant negative correlation between creatinine clearance (CCr) value and the trough concentrations of the morphine metabolites was observed. On the other hand, no significant correlation was found between CCr value and the pharmacokinetic parameters of oxycodone or its metabolites. CONCLUSIONS For patients who had difficulty in continuing oral morphine treatment, regardless of renal function, opioid rotation to oral oxycodone may be an effective approach to alleviate intolerable side effects and pain.

Outline of JUA clinical guidelines for benign prostatic hyperplasia

The Japanese Urological Association has developed Clinical Guidelines for Benign Prostatic Hyperplasia (BPH) for men with suspected BPH, which have been abridged and translated into English. This article is a shortened version of the English translation. The Guidelines were formulated on the basis of evidence retrieved from the PubMed database between 1995 and 2009, as well as other relevant sources. The target patients of these Guidelines are men with suspected BPH, and the target users are urologists. A mandatory assessment should include a medical history, a physical examination, the completion of symptom and quality of life questionnaires, urinalysis, prostate ultrasonography, measurement of serum prostate specific antigen and postvoid residual urine, and an uroflowmetry. Optional tests include a bladder diary, the measurement of serum creatinine, and upper urinary tract ultrasonography. Care should be taken to not overlook coexisting diseases such as an infection or malignancy that may obscure the diagnosis. Treatment should consist of conservative therapy or the use of medications such as α1‐adrenoceptor antagonists, or both. The use of 5α‐reductase inhibitors or anticholinergic agents should be considered in patients with an enlarged prostate (>30 mL) or overactive bladder symptoms (overactive bladder symptom score ≥6), respectively. Surgical intervention is indicated when non‐surgical treatments fail to provide sufficient symptomatic relief and bladder outlet obstruction is highly suspected.