No clinical significance of the time interval between biopsy and robotic-assisted radical prostatectomy for patients with clinically localized prostate cancer on biochemical recurrence: a propensity score matching analysis.

PURPOSE: To investigate the impact of the time interval (TI) between prostate biopsy and robot-assisted radical prostatectomy (RARP) on the risk of biochemical recurrence (BCR). METHODS: We retrospectively reviewed the medical records of 793 consecutive patients who were treated with RARP at our institution. Patients were divided into three groups, according to TI, to compare BCR-free survival (BCRFS) rates: Group 1 (n = 196), TI < 3 months; Group 2 (n = 513), 3 ≤ TI < 6 months; Group 3 (n = 84), TI ≥ 6 months. Eighty-three patients with TI ≥ 6 months were matched with an equal number of patients with TI < 6 months based on propensity scores by using four preoperative factors: prostate-specific antigen (PSA), primary (pGS) and secondary (sGS) Gleason score and positive prostate biopsy. RESULTS: The 5-year BCRFS rates for TI Groups 1, 2, and 3 were 76%, 80.7% and 82.6% (P = 0.99), respectively. The multivariate analysis revealed that PSA, pGS, sGS and a positive prostate biopsy were independent preoperative risk factors for BCR. The propensity adjusted 5-year BCRFS for patients with TI ≥ 6 months was 84.0%. This was not worse than that of patients with TI < 6 months (71.0%, P = 0.18). CONCLUSIONS: In our cohorts, a delay in the time from biopsy to RARP did not significantly affect recurrence. Therefore, hasty treatment decisions are unnecessary for at least 6 months after diagnosis of early prostate cancer.

Impact of Surgeon and Hospital Volume on the Safety of Robot-Assisted Radical Prostatectomy: A Multi-Institutional Study Based on a National Database.

INTRODUCTION: We aimed to perform a multi-institutional study using a national database led by the Japanese Society of Endourology to investigate the effect of surgeon or hospital volume on the safety of robot-assisted radical prostatectomy (RARP). MATERIALS AND METHODS: Clinical data of 3,214 patients who underwent RARP for the treatment of clinically localized prostate cancer between April 2012 and March 2013 in Japan were evaluated. Surgical outcomes and all intra- and perioperative complications were collected. RESULTS: The intraoperative complication rate was 0.56%. In a total number of 241 patients, 261 perioperative complications were observed. The following percentages of patients presented the Clavien-graded complications: 7.2%, grades 1-2; 0.84%, grade 3; and 0.093%, grade 4a. No cases of multiple organ dysfunction or death (grades 4b and 5) were found. Multivariable logistic regression analysis showed that the hospital volume (OR 3.6; p = 0.010) for intraoperative complications and surgeon volume (OR 0.19; p < 0.0001) and extended lymph node discectomy (OR 3.9; p < 0.0001) for perioperative complications were significant independent risk factors. CONCLUSIONS: Hospital volume for intraoperative complications and surgeon volume and extended lymph node dissection for perioperative complications were significantly associated with increased risk of each complication in RARP.

Reality of nerve sparing and surgical margins in surgeons' early experience with robot-assisted radical prostatectomy in Japan.

OBJECTIVE: To analyze nerve sparing performance at an early stage of robot-assisted radical prostatectomy, and the correlation between the surgeons' experience and the risk of a positive surgical margin in patients treated with robot-assisted radical prostatectomy. METHODS: Patients' records from January 2009 to March 2013 were retrospectively reviewed, and 3469 patients with localized prostate cancer were identified at 45 institutions. Individual surgeon's experience with nerve sparing was recorded as the number of nerve sparing cases among total robot-assisted radical prostatectomies beginning with the first case during which nerve sparing was carried out. Patients were selected by propensity score matching for nerve sparing, and predictive factors of positive surgical margins were analyzed in patients with and without positive surgical margins. RESULTS: A total of 152 surgeons were studied, and the median number of robot-assisted radical prostatectomy cases for all surgeons was 21 (range 1-511). In all, 54 surgeons (35.5%) undertook nerve sparing during their first robot-assisted radical prostatectomy case. For 2388 patients selected with (1194) and without (1194) nerve sparing, predictive factors for positive surgical margin were high initial prostate-specific antigen level (P < 0.0001), high biopsy Gleason score (P = 0.0379), presence of neoadjuvant hormone therapy (P = 0.0002) and surgeon's experience with >100 cases (P = 0.0058). Thus, nerve sparing was not associated with positive surgical margins. CONCLUSION: The surgeon's experience influences the occurrence of positive surgical margins, although a considerable number of surgeons carried out nerve sparing during their early robot-assisted radical prostatectomy cases. Surgeons should consider their own experience and prostate cancer characteristics before carrying out a nerve sparing robot-assisted radical prostatectomy.

Impact of a preoperatively estimated prostate volume using transrectal ultrasonography on surgical and oncological outcomes in a single surgeon's experience with robot-assisted radical prostatectomy.

BACKGROUND: To assess the impact of preoperatively estimated prostate volume (PV) using transrectal ultrasonography (TRUS) on surgical and oncological outcomes in robot-assisted radical prostatectomy (RARP). METHODS: We analyzed the experience of a single surgeon at our hospital who performed 436 RARPs without neoadjuvant hormone therapy between August 2006 and December 2013. Patients were divided into three groups according to their preoperative PV calculated using TRUS (PV ≤ 20 cm(3): group 1, n = 61; 20 < PV < 50 cm(3): group 2, n = 303; PV ≥ 50 cm(3): group 3, n = 72). RESULTS: Blood loss was significantly higher in group 3 than in group 1 and group 2. In stage pT2 patients, the rate of positive surgical margin (PSM) was significantly lower in group 3 than in group 1. In addition, perioperative complications significantly increased with increasing PV, while the extraprostatic extension (EPE) rate significantly decreased with increasing PV. The preoperative biopsy Gleason score, prostate-specific antigen (PSA) density, and clinical T2 stage were inversely correlated with increasing PV. Biochemical recurrence-free survival after RARP was significantly lower in group 1 than in groups 2 and 3. CONCLUSIONS: A large prostate size was significantly associated with increased blood loss and a higher rate of perioperative complications. A small prostate size was associated with a higher PSM rate, PSA density, Gleason score, EPE rate, and biochemical recurrence rate. These results suggest that RARP was technically challenging in patients with large prostates, whereas small prostates were associated with unfavorable oncological outcomes.

Prediction of renal function after nephroureterectomy in patients with upper tract urothelial carcinoma.

OBJECTIVE: The estimated glomerular filtration rate is significantly decreased after nephroureterectomy. Deteriorating renal function likely affects the eligibility for cisplatin-based chemotherapy in patients with upper tract urothelial carcinoma. The present study was undertaken to identify preoperative factors for the prediction of postoperative renal function and develop a prediction model. METHODS: Between June 1996 and January 2014, 110 patients who underwent radical nephroureterectomy at our institution were analyzed in this study. The estimated glomerular filtration rate was calculated using the Modification of Diet in Renal Disease study equation. Univariate linear regression analyses were performed to investigate the correlation between postoperative estimated glomerular filtration rate and preoperative variables. A stepwise multivariate linear regression analysis was performed to identify independent predictors of postoperative estimated glomerular filtration rate. RESULTS: Comparison of preoperative and postoperative estimated glomerular filtration rate for each patient showed a median difference of 13.1 ml/min/1.73 m(2). The postoperative estimated glomerular filtration rate was significantly lower than the preoperative estimated glomerular filtration rate (P < 0.001). On univariate analysis, age and preoperative estimated glomerular filtration rate were significantly correlated with postoperative estimated glomerular filtration rate. On multivariate analysis, age, preoperative estimated glomerular filtration rate and the presence of hydronephrosis were independent predictive factors of postoperative estimated glomerular filtration rate. The predicted postoperative estimated glomerular filtration rate, which was calculated using these independent factors, showed a significant correlation with the observed postoperative estimated glomerular filtration rate (correlation coefficient = 0.7533). CONCLUSIONS: Age, preoperative estimated glomerular filtration rate and the presence of hydronephrosis were independent predictors of postoperative estimated glomerular filtration rate in patients with upper tract urothelial carcinoma treated with radical nephroureterectomy. The predicted postoperative estimated glomerular filtration rate based on these factors may be useful for choosing alternative management strategies such as neoadjuvant chemotherapy for patients with upper tract urothelial carcinoma.

Prediction of biochemical recurrence after robot-assisted radical prostatectomy: analysis of 784 Japanese patients.

OBJECTIVES: To examine biochemical recurrence after robot-assisted radical prostatectomy in Japanese patients, and to develop a risk stratification model for biochemical recurrence. METHODS: The study cohort consisted of 784 patients with localized prostate cancer who underwent robot-assisted radical prostatectomy without neoadjuvant or adjuvant endocrine therapy. The relationships of biochemical recurrence with perioperative findings were evaluated. The prognostic factors for biochemical recurrence-free survival were evaluated using Cox proportional hazard model analyses. RESULTS: During the follow-up period, 80 patients showed biochemical recurrence. The biochemical recurrence-free survival rates at 1, 3, and 5 years were 92.2%, 85.2% and 80.1%, respectively. In univariate analysis, the prostate-specific antigen level, prostate-specific antigen density, biopsy Gleason score, percent positive core, pathological T stage, pathological Gleason score, lymphovascular invasion, perineural invasion and positive surgical margin were significantly associated with biochemical recurrence. In multivariate analysis, prostate-specific antigen density ≥0.4 (P = 0.0011), pathological T stage ≥3a (P = 0.002), pathological Gleason score ≥8 (P = 0.007) and positive surgical margin (P < 0.0001) were independent predictors of biochemical recurrence. The patients were stratified into three risk groups according to these factors. The 5-year biochemical recurrence-free survival rate was 89.4% in the low-risk group, 65.6% in the intermediate-risk group and 30.3% in the high-risk group. CONCLUSIONS: The prostate-specific antigen density, pathological T stage, pathological Gleason score and positive surgical margin were independent prognostic factors for biochemical recurrence. The risk stratification model developed using these four factors could help clinicians identify patients with a poor prognosis who might be good candidates for clinical trials of alternative management strategies.

Preoperative prognostic factors for biochemical recurrence after robot-assisted radical prostatectomy in Japan.

PURPOSE: We investigated oncological outcomes in Japanese patients who underwent robot-assisted radical prostatectomy (RARP). MATERIALS AND METHODS: This study included 389 patients who underwent RARP at a single institution with a follow-up period of at least 1 year. Preoperative findings were compared with biochemical recurrence (BCR). Predictors of BCR-free survival (BCRFS) were evaluated by univariate and multivariate Cox proportional hazard model analyses, and a risk stratification model based on the relative risks of BCR was established. RESULTS: Fifty incidences of BCR were noted during a median follow-up period of 28.7 months (range, 12.1-80.0 months). The BCRFS rate for the entire cohort at the median follow-up time was 85.9 %; the 1-, 3-, and 5-year estimates were 91.0, 85.1, and 81.1 %, respectively. From univariate analyses, prostate-specific antigen (PSA), PSA density, biopsy Gleason score, and percent positive core were significantly associated with BCR. Multivariate analysis showed that PSA [hazard ratio (HR), 2.75; p = 0.001], percent positive core (HR, 2.22; p = 0.001), and biopsy Gleason score (HR, 2.61; p = 0.007) were independent predictors of BCR. CONCLUSION: This study at a single Japanese center demonstrates that RARP provides a satisfactory BCRFS rate. This report provides a framework with which to estimate oncological outcomes in patients who underwent RARP for localized prostate cancer. Our results support the increased use of RARP for the treatment of localized prostate cancer in Japan.

[Robot-assisted surgery-the current state of radical prostatectomy].

Minimally invasive surgeries such as laparoscopic surgery and robot-assisted surgery have become validated treatment modalities and hold a prominent position in clinical practice. Robot-assisted radical prostatectomy(RARP)is a relatively new procedure. Because this technique does not require the urologist to overcome a steep and long learning curve, a dramatic increase in the number of RARP surgeries was observed in recent years and RARP has rapidly gained acceptance in the Japanese urological community after its introduction in Japan in 2006. Robot-assisted surgery that combines optical magnification, three-dimensional vision, and instruments with 7 degrees of freedom allows surgeons to perform meticulous, precise, and accurate movements. In summary, for the previously mentioned reasons, RARP is considered to be an effective procedure for improving intraoperative blood loss, the transfusion and complication rates, as well as the recovery of urinary continence and potency rates. In this article, we briefly describe the evolution of this minimally invasive technique. In addition, we present the current state of RARP and a critical evaluation of the learning curves associated with performing RARP as well as published oncological, continence, and potency outcomes.

Clinical Anatomy of the Superficial Preprostatic Vein and Accessory Pudendal Artery in Robot-Assisted Radical Prostatectomy.

Purpose: We herein describe the superficial preprostatic vein (SPV) anatomy and determine its relationship with the accessory pudendal artery (APA). Materials and Methods: We reviewed 500 patients with localized prostate cancer who underwent conventional robot-assisted radical prostatectomy between April 2019 and March 2023 at our institution. SPV was defined as "any vein coming from the space between the puboprostatic ligaments and running within the retropubic adipose tissue anterior to the prostate toward the vesical venous plexus or pelvic side wall." While APA was defined as "any artery located in the periprostatic region running parallel to the dorsal vascular complex and extending caudal toward the anterior perineum." The intraoperative anatomy of each SPV and APA was described. Results: SPVs had a prevalence rate of 88%. They were preserved in 252 men (58%) and classified as I-, reversed-Y (rY)-, Y-, or H-shaped (64%, 22%, 12%, and 2%, respectively) based on their intraoperative appearance. Overall, 214 APAs were found in 142 of the 252 men with preserved SPV (56%; 165 lateral and 50 apical APAs in 111 and 41 men, respectively). SPVs were pulsatile in 39% men perhaps due to an accompanying tiny artery functioning as a median APA. Pulsations seemed to be initially absent in most SPVs but become apparent late during surgery possibly due to increased arterial and venous blood flow after prostate removal. Pulsations were common in men with ≥1 APA. Conclusions: This study, which described the anatomical variations in arteries and veins around the prostrate and their preservation techniques, revealed that preserving this vasculature may help preserve postprostatectomy erection. ClinicalTrials: The Clinical Research Registration Number is 230523D.

Inguinal hernia leads to worse immediate urinary continence after robot-assisted radical prostatectomy.

OBJECTIVES: Patients with inguinal hernia (IH) may have voiding dysfunction and weak urethra-stabilizing periurethral fascial tissues, contributing to urinary incontinence. This study aimed to review the association between IH and urinary continence after robotic-assisted radical prostatectomy (RARP). METHODS: This single-institution retrospective study included 251 consecutive cases of RARP between April 2019 and June 2022. Patients with concurrent IH or a history of adult IH repair were examined. The urine loss rate (ULR), defined as 24-h urine loss volume divided by the total urine volume immediately after urinary catheter removal (i.e., 6 or 7 postoperative days), was compared between the groups with (n = 33) and without IH (n = 214). Possible contributing factors for ULR were assessed, including age, body mass index (BMI), after benign prostatic hyperplasia surgery, prostate weight, and nerve-sparing. ULR was compared intergroup after propensity score matching countering selection biases. RESULTS: Patients with IH were older (71.3 versus. 66.8 years, p < 0.01), had lower BMI (22.8 versus. 24.3, p < 0.01), and had higher ULR (14.5% versus. 5.1%, p < 0.01). In a multiple linear regression analysis (adjusted R2 = 0.084), IH (p < 0.01) was an independent contributing factor for ULR besides advancing age (p < 0.03). After propensity score matching adjusted for patient's age and nerve-sparing, patients with IH had higher ULR (14.1% versus. 5.7%, p < 0.03) as well. CONCLUSIONS: This study first reported that IH may be one of the risk factors of urinary incontinence after RARP.

Predictors for positive surgical margins after robot-assisted radical prostatectomy: a single surgeon's series in Japan.

OBJECTIVE: Positive surgical margin after radical prostatectomy has been shown to be an independent predictive factor for biochemical and local recurrence in patients with prostate cancer. The present study was undertaken to identify predictive factors for positive surgical margin after robot-assisted radical prostatectomy in Japanese patients. METHODS: Between August 2006 and September 2011, a cohort of 244 men underwent robot-assisted radical prostatectomy carried out by a single surgeon. Univariate and multivariate logistic regression analyses were carried out to identify clinical covariates significantly associated with an increased positive surgical margin. The preoperative variables included age, body mass index, prostate-specific antigen level, prostate-specific antigen density, clinical T stage, prostate volume, surgeon volume, number of positive cores and percentage of positive cores. RESULTS: In the univariate analyses, serum prostate-specific antigen level, prostate-specific antigen density and surgeon volume were significantly associated with positive surgical margin. In the multivariate analysis, prostate-specific antigen density (hazard ratio 3.13, 95% confidence interval 1.57-6.24; P = 0.001) and surgeon volume (hazard ratio 2.15, 95% confidence interval 1.06-4.35; P = 0.034) were independent predictive factors for positive surgical margin. Using these two independent factors, we divided the patients into four groups and calculated the predictive probability of positive surgical margin. The predictive probability for positive surgical margin in each group was well correlated with the rates at 10.8% and 10.2%, 19.8% and 20.0%, 26.4% and 26.4%, an 43.5% and 43.3%, respectively. CONCLUSION: Prostate-specific antigen density and surgeon volume are independent predictors of positive surgical margin after robot-assisted radical prostatectomy. A combination of these two factors can provide useful information about positive surgical margins.

Robotic versus open radical cystectomy: prospective comparison of perioperative and pathologic outcomes in Japan.

OBJECTIVE: In Japan, no study has compared the perioperative outcomes observed between robot-assisted radical cystectomy (RARC) and open radical cystectomy (ORC). This study aimed at a prospective comparison of the perioperative outcomes between RARC and ORC performed by a single surgeon. METHODS: Between 2008 and 2011, 26 bladder cancer patients underwent radical cystectomy by one surgeon, 11 robotically and 15 by open procedure. We prospectively collected perioperative and pathological data for these 26 patients, and retrospectively compared these two different surgical procedures. RESULTS: The RARC cohort had a significant decrease in both estimated blood loss (656.9 vs. 1788.7 ml, P=0.0015) and allogeneic transfusion requirement (0 vs. 40%, P=0.0237). The total operative time was almost the same (P=0.2306) but increased duration of bladder removal and lymphadenectomy was observed in the RARC cohort (P=0.0049). Surgery-related complication rates within 30 days were not significantly different (P=0.4185). Positive surgical margin was observed in three patients in the ORC cohort and in one patient in the RARC cohort (P=0.4664). The RARC cohort had a larger number of removed lymph nodes than the ORC cohort, and the difference was statistically significant (20.7 vs. 13.8, P=0.0421). CONCLUSIONS: We confirmed that RARC is safe and yields acceptable outcomes in comparison with ORC for the treatment of bladder cancer if it is performed by a surgeon who has experience of over 60 cases of robot-assisted radical prostatectomy. It is hoped that RARC will gain acceptance in Japan as a minimally invasive surgery for muscle-invasive bladder cancer.

Risk stratification of survival by lymphovascular invasion, pathological stage, and surgical margin in patients with bladder cancer treated with radical cystectomy.

BACKGROUND: The aim of this study was to investigate prognostic factors and develop a prognostic factor-based risk stratification model for disease-specific survival (DSS) in a radical cystectomy (RC) series. METHODS: The patient cohort comprised 194 consecutive patients with bladder cancer treated with RC. Univariate and multivariate Cox proportional hazard model analyses were performed to identify significant prognostic factors for DSS. A risk stratification model was developed based on the relative risks (RRs) of DSS. RESULTS: Median follow-up period was 26.8 months. The 1-, 3-, and 5-year DSS were 88.0, 74.0, and 64.9%, respectively. In the univariate analysis, pathological T (pT) (≥ pT2), lymphovascular invasion (LVI), non-urothelial carcinoma component, surgical margin (SM), and lymph node metastases (pN) were significantly associated with poor prognosis. In the multivariate analysis, pT (≥ pT2), LVI, and SM were independent factors for predicting poor prognosis. Based on these results, patients were stratified into three risk groups: low (RR = 1.00-3.626), intermediate (5.860-9.826), and high (21.24). The 1-, 3-, and 5-year survival rates were 96.9, 85.1, and 85.1% in the low-risk group, 83.0, 63.4, and 43.8% in the intermediate group, and 51.0, 19.4, and 19.4% in the high-risk group, respectively. The differences among these groups were significant. CONCLUSIONS: In our RC series, pT (≥ pT2), LVI, and SM were independent prognostic factors. This information may be useful to identify patients with poor prognosis, who might be good candidates for innovative treatment.

[Robot-assisted radical prostatectomy].

Robot-assisted radical prostatectomy(RARP)has emerged in the last decade. It has greatly improved clinical management of localized prostate cancer. Its use has been justified by its satisfactory oncological and functional outcomes and its fewer perioperative complications. RARP has the advantages of both conventional open radical retropubic prostatectomy and laparoscopic radical prostatectomy. However, its increased cost and the lack of tactile sensation it induces still remain problems.

Radical retropubic prostatectomy with running vesicourethral anastomosis and early catheter removal: our experience.

OBJECTIVES: To assess the outcomes of patients undergoing radical retropubic prostatectomy (RRP) with a running vesicourethral anastomosis and catheter removal on postoperative day 3 or 5. METHODS: From February 2006 through December 2007, 55 patients underwent RRP at our institution. All procedures were performed by a single surgeon using a running suture for the vesicourethral anastomosis. A cystogram was carried out before catheter removal in all patients. The initial 23 of 55 patients (Group 1; n = 23) had the cystogram on postoperative day 5, the other 32 patients (Group 2; n = 32) had the cystogram on postoperative day 3. Removal of the catheter was only carried out if there was no anastomotic extravasation. RESULTS: The success rate of catheter removal in group 1 and 2 was 100% and 96.9%, respectively. Overall continence rates were 83.3%, 87% and 90.7% at 24, 48 and 72 h after removal of the catheter, respectively. There was no significant difference in terms of continence rate between groups 1 and 2. None of the patients had acute urinary retention and/or anastomotic stricture after catheter removal. CONCLUSIONS: These findings suggest that an advanced running vesicourethral anastomosis during RRP is technically feasible, allowing safe early catheter removal in most patients.

[Case of renal cell carcinoma metastasized to iliopsoas muscle].

Skeletal muscle metastasis is a rare event in renal cell carcinoma (RCC). Only thirty-two cases have been reported until now. A 69-year-old female had a nephrectomy for right RCC (clear cell carcinoma, grade 2, pT1) in 1994. She has been followed up every three months after nephrectomy. After twelve years from nephrectomy, computed tomography (CT) showed a 3 cm mass in the right iliopsoas muscle. CT guided needle biopsy revealed tumor cells suspicious of renal cell carcinoma metastasis. The tumor was surgically removed and histologically diagnosed as renal cell carcinoma metastasized to the iliopsoas muscle.

Prognostic significance of tenascin-C expression in clear cell renal cell carcinoma.

Tenascin-C is an extracellular matrix protein that plays an important role in cell proliferation, migration and tumor invasion in various types of cancer. However, few reports exist on tenascin-C expression in renal cell carcinoma (RCC). This study aimed to assess the prognostic significance of tenascin-C in clear cell RCC. Using immunohistochemistry, 137 formalin-fixed, paraffin-embedded tissue sections obtained from patients with clear cell RCC were examined for tenascin-C expression. Tenascin-C expression was observed in 55 (40.1%) of the 137 clear cell RCC sections. Tumor cells displayed membranous and/or cytoplasmic staining for tenascin-C. Tenascin-C expression was more prominent near the pseudocapsule of the tumor and around the tumor vessels. Tenascin-C expression was significantly associated with a higher stage (P=0.0065) and higher nuclear grade (P=0.0001). However, there was no correlation between the tenascin-C expression and venous involvement. The cancer-specific survival rate in patients with a tenascin-C-positive primary tumor was significantly lower than that in those with a tenascin-C-negative primary tumor in univariate analysis (P=0.0017). However, tenascin-C expression did not exhibit a significant value for cancer-related death in the Cox regression analysis. In patients with stage 1-3 disease, the 5-year metastasis-free rate in patients with the tenascin-C-positive primary tumor was significantly lower than that in those with the tenascin-C-negative primary tumor (67.8 vs. 88.5%, respectively; P=0.0038). The Cox regression analysis showed that tenascin-C expression is a significant predictor of metastasis (P=0.0345). The tenascin-C expression was strongly related to the stage, nuclear grade and 5-year metastasis-free rate. Therefore, tenascin-C expression may be a possible marker for the metastatic potential of clear cell RCC.

Characterization and gene expression analysis of novel matched primary and metastatic renal cell carcinoma cell lines.

Despite recent advances in molecular biology that have clarified the mechanisms involved in the metastasis of several types of cancer, the molecular mechanism underlying the metastasis of renal cell carcinoma (RCC) remains unclear. Two RCC cell lines were successfully established from the surgical specimens of a matched primary tumor and adrenal metastasis from the same RCC patient, and were designated as TMK-1P and TMK-1M, respectively. Extensive characterization was accomplished using various methods, including the Matrigel invasion assay, DNA microarray analysis and real-time reverse transcriptase (RT)-polymerase chain reaction (PCR). While TMK-1P grew faster than TMK-1M, the invasive ability of TMK-1M was higher than that of TMK-1P. DNA microarray analysis showed a large differential expression of genes related to cell adhesion and the extracellular matrix molecules of which hexabrachion (tenascin-C), epidermal growth factor receptor, cadherin-6, and beta1-catenin were down-regulated, and the 67 kDa laminin receptor 1 and transforming growth factor-beta-induced 68 kDa protein (betaig-h3) were up-regulated in TMK-1M. Real-time RT-PCR analysis confirmed this differential gene expression between the two cell lines. The RCC cell lines may be useful in studying tumor invasion and screening markers for metastasis.

Effects of a KiSS-1 peptide, a metastasis suppressor gene, on the invasive ability of renal cell carcinoma cells through a modulation of a matrix metalloproteinase 2 expression.

Although effects of a metastasis suppressor gene, KiSS-1, have been postulated to be mediated by its receptor, hOT7T175, the mechanism of such effects remains unknown. This study was designed to evaluate the mechanism of how KiSS-1 works and to assess effects of a synthesized truncated KiSS-1 protein on the invasive ability of renal cell carcinoma (RCC) cells. Four RCC cell lines, Caki-1, KU19-20, RSP and RSM, were investigated to determine mRNA expressions of KiSS-1, its receptor, hOT7T175, matrix metalloproteinases (MMPs) and MMP inhibitors. While all cell lines demonstrated hOT7T175 mRNA expressions, only Caki-1 had KiSS-1 transcripts. A synthesized truncated KiSS-1 peptide, metastin (45-54), produced a marked suppression of the invasive ability in KU19-20 cells, which were deficient for KiSS-1 transcripts, but not in Caki-1 cells. Metastin (45-54) also increased the ability of KU19-20 cells to attach to collagen 4. Both MMP-2 mRNA levels and protein production were significantly decreased only in KU19-20 cells by metastin (45-54). In conclusion, metastin (45-54) may have potential therapeutic use by suppressing the motility and invasive ability of RCC cells which possess hOT7T175 with either a negative expression or very low expression level of KiSS-1 through, at least in part, the down-regulation of MMP-2.