Kenichiro Okada

Fdg Pet for evaluating the change of glucose metabolism in prostate cancer after androgen ablation

In the clinical study of prostate cancer, the effect of androgen ablation on glucose metabolism in cancer tissue has not been elucidated. The purpose of this study was to investigate the change in glucose utilization due to endocrine therapy for prostate adenocarcinoma. Ten patients with histologically proven prostate cancer were prospectively investigated with 18F-fluorodeoxyglucose and positron emission tomography (FDG PET) prior to and after the initiation of endocrine therapy. FDG uptake was calculated to measure glucose utilization in cancer tissue. The change in FDG accumulation was compared with changes in serum prostate specific antigen (PSA) level and prostate size. FDG accumulation in the prostate decreased in all patients 1-5 months after the initiation of hormone therapy. The serum PSA level and prostate size measured on computerized tomography (CT) also decreased in these periods. A decrease in FDG accumulation was also demonstrated in metastatic sites. In this study, there appeared to be a decrease in FDG uptake in prostate cancer after endocrine therapy not only in primary prostate cancer lesions but also at metastatic sites, suggesting that the glucose utilization by tumours was suppressed by androgen ablation.

Prognostic value of 2-deoxy-2-[F-18]fluoro-D-glucose positron emission tomography imaging for patients with prostate cancer.

PURPOSE The purpose of this study was to investigate the prognostic value of measuring glucose metabolism of primary prostate cancer lesions, using 2-Deoxy-2-[F-18]Fluoro-D-Glucose positron emission tomography (FDG-PET). PROCEDURES Forty-two patients with prostate cancer were investigated with FDG-PET, and standardized uptake value (SUV) of the prostate was calculated. After PET study, radical prostatectomy was performed in 17 patients (RPT group), and endocrine therapy in 25 patients (ET group). Relapse-free survival curves were created by the Kaplan-Meier method. RESULTS In the RPT group, the patients with high SUV had a poorer prognosis compared to those with low SUV (P = 0.033). In the ET group, the patients with high SUV were likely to have a poorer prognosis with low significance at a level of P = 0.087. CONCLUSIONS FDG-PET appeared to have a defined prognostic value for patients with prostate cancer undergoing radical prostatectomy, and more patients need to be studied for patients undergoing endocrine therapy.

TISSUE SELECTIVITY OF KMD-3213, AN α1-ADRENOCEPTOR ANTAGONIST, IN HUMAN PROSTATE AND VASCULATURE

Purpose: We evaluated the binding and functional affinity of KMD-3213 and other α1-adrenoceptor (AR) antagonists such as prazosin or tamsulosin, to compare the tissue selectivity of these antagonists between human prostate and vasculature.Materials and Methods: In the binding experiments, saturation experiments using [3H]-KMD and [3H]-prazosin (PZ) were performed, and competition of [3H]-PZ binding by antagonists was also examined in human prostatic and aortic membranes. In the functional study, contractile responses to noradrenaline were evaluated in human prostate and mesenteric artery.Results: [3H]-PZ bound to human prostatic and aortic membranes with subnanomolar affinity. [3H]-KMD also bound to human prostate, with higher affinity than [3H]-PZ; whereas it did not bind sufficiently to human aorta. Competition of [3H]-PZ binding revealed that KMD-3213 had more than 200-fold higher affinity for human prostate than for aorta. Binding profiles of antagonists revealed that human prostate predominantly expr...

Id2 haploinsufficiency in mice leads to congenital hydronephrosis resembling that in humans

Congenital hydronephrosis is one of the most common anomalies found in humans and may cause renal failure in childhood. Half of the cases are due to obstruction at the ureteropelvic junction (UPJ). Here we report that mice lacking Id2, an inhibitor of basic helix‐loop‐helix (bHLH) transcription factors, exhibit hydronephrosis mimicking the characteristics of human cases such as unilaterality and male preponderance. Hydronephrosis was found even in Id2+/– mice. The penetrance was 67.2% in Id2−/– males, 48.8% in Id2+/– males, 28.0% in Id2−/– females and 20.0% in Id2+/– females. Distortion or high insertion of the ureter at the UPJ was frequently observed and these morphological changes were evident in late embryogenesis. Histologically, the muscle layer, where Id2 is normally expressed, was hypertrophic and/or irregular at the UPJ. Furthermore, gene expression analysis suggested that BMP4 (bone morphogenetic protein 4), which is known to be involved in the development of hydronephrosis, appears to function as an upstream factor of Id2. Our results thus raise the possibility that Id2 is a gene responsible for the pathogenesis of hydronephrosis in man.

Reciprocal expression of bcl-2 and p53 oncoproteins in urothelial dysplasia and carcinoma of the urinary bladder

Abstract In order to investigate if and when the bcl-2 oncoprotein is activated in bladder tumorigenesis and its relationship with p53 overexpression and patient survival, we studied bcl-2 and p53 expression immunohistochemically in matched normal urothelium, dysplasia and cancer specimens selected by step-sectioning from 54 radically resected bladders for non-metastatic transitional cell carcinoma (TCC). In normal urothelium and mild dysplasia, bcl-2 was restricted to the basal cell compartment, while in moderate and severe dysplasia its expression was detectable also in the upper regions. Excess bcl-2 immunoreactivity was found in 27 (50%) of carcinomas, and a larger proportion of high-grade TCCs showed bcl-2 expression compared with that of low-grade TCCs (P < 0.05). Overexpression of p53 protein showed a increasing trend toward the progression of bladder tumorigenesis (P < 0.01) and a significant reciprocal correlation was found between bcl-2 and p53 expression in either various dysplasias (P < 0.01) or carcinoma (P < 0.05). With the evolution from mild dysplasia to carcinoma in individual cases, loss of bcl-2 expression was more frequently observed in superficial (P < 0.02) or low-grade carcinoma (P < 0.05) than in muscle-invasive or high-grade carcinoma. Furthermore, patients with negative immunostaining for both bcl-2 and p53 in cancer lesions had a significantly more favorable prognosis compared with those with positive immunostaining for the oncoproteins (P < 0.05), although bcl-2 by itself did not predict patient survival. We suggest that aberrant activated bcl-2, which is seen earlier than p53, appears to facilitate bladder tumorigenesis and to enhance tumor aggression in some extent.

Differentiation of prostate cancer from benign prostate hypertrophy using dual-echo dynamic contrast MR imaging

OBJECTIVE To investigate the usefulness of dynamic contrast magnetic resonance (MR) imaging in the differentiation of prostate cancer (PC) from benign prostate hypertrophy (BPH). MATERIALS AND METHODS Eleven PC patients and 13 BPH patients were entered into the analysis. The mean gradient (MG) was calculated from the T2* term-eliminated time-signal intensity curve obtained from dynamic contrast MR data, and the MG of PC and that of BPH were compared. RESULTS The MG of PC was significantly higher than that of BPH. When the threshold value was set to 1.88% per s for discriminating PC from BPH, the sensitivity, specificity, and accuracy were 100, 85, and 92%, respectively. CONCLUSION The MG, which is derived from the T2* term-eliminated time-signal intensity curve, may be a useful index for differentiating PC from BPH.

Bladder Dysfunction in Patients with Benign Prostatic Hyperplasia: Relevance of Cystometry as Prognostic Indicator of the Outcome after Prostatectomy

Background: We correlated cystometric findings to the clinical features of benign prostatic hyperplasia (BPH) and compared them in terms of outcome after prostatectomy.

Prognostic value of nuclear morphometry on needle biopsy from patients with prostate cancer: is volume-Weighted mean nuclear volume superior to other morphometric parameters?

OBJECTIVES To compare the prognostic value of stereologically estimated volume-weighted mean nuclear volume (MNV) with other nuclear morphometric parameters using pretreatment needle-biopsy specimens of prostate cancer. METHODS The MNV, mean nuclear area, form factor, and coefficients of variation for nuclear area (VNA) and form factor were measured on pretreatment needle biopsy specimens from 66 patients with prostate cancer (clinical Stage B, n = 9; Stage C, n = 14; and Stage D, n = 43), all of whom underwent androgen deprivation therapy. The prognostic value of those morphometric parameters, as well as Gleason score and clinical stage, was examined in terms of cause-specific patient survival using univariate and multivariate analysis (Cox proportional hazard model). RESULTS Univariate analysis of the nuclear morphometric parameters revealed that MNV, mean nuclear area, VNA, coefficient of variation for form factor, and clinical stage were significant prognostic factors for cause-specific patient survival. However, when the patients with Stage D disease were selectively analyzed for survival, only the VNA was a significant prognostic parameter. Furthermore, the multivariate analysis, including the morphometric parameters, clinical stage, and Gleason score revealed that only VNA and clinical stage were independent variables. CONCLUSIONS The present comparative study could not demonstrate any prognostic superiority of MNV over other nuclear morphometric parameters in patients with prostate cancer.

Immunohistochemical expression of p53 and bcl-2 proteins is not associated with sarcomatoid change in renal cell carcinoma

Abstract An immunhistochemical study was conducted to examine the expression of p53 and bcl-2 proteins in RCC (renal cell carcinoma) with sarcomatoid change in order to determine whether abnormalities in those proteins are associated with an enhanced malignant potential of RCC. Paraffin-embedded tissues from 11 patients with RCC, in which sarcomatoid change was prominent, were stained using anti-p53, bcl-2 and Ki-67 antibodies. Immunoreactivities for these antibodies were compared between the sarcomatoid components and corresponding basic histologic (clear or papillary) components in individual cases. Measurement of the mean nuclear areas of each component was also performed using an image analyzer system. There was no substantial increase in immunoreactivity for p53 or bcl-2 proteins in sarcomatoid components as compared with basic components. In contrast, the percentage of Ki-67-positive cells and the mean nuclear area were signficantly larger in sarcomatous components than in basic components. The expression of p53 and bcl-2 proteins was not likely to play a major role in the sarcomatoid change of RCC.

Analysis of Histological Heterogeneity in Renal Cell Carcinoma: Tumor Size‐Related Histological Change and its Prognostic Significance

Background: It is well recognized that the histology of renal cell carcinoma (RCC) is often heterogenous. It is also believed that the prognosis of patients with large tumors is generally poorer than those with small tumors. However, there has been no detailed study on changes in histological features of RCCs associated with tumor growth. This study was conducted to investigate whether there are any specific histological changes related to tumor size and to study the prognostic value of histological parameters in RCCs.