Immunomodulatory response of layered small intestinal submucosa in a rat bladder regeneration model.

Based on the hypothesis that bioscaffold permeability is a major factor in determining the outcome of histologically complete and functional bladder regeneration, we evaluated regeneration processes of four-layer porcine small intestinal submucosa (SIS) construct; and compared results between rat bladders augmented with single-layer SIS bioscaffolds. Sprague-Dawley female rats were subjected to hemi-cystectomy followed by anastomosis of a patch of either single- or four-layer porcine SIS. Permeability was analyzed in situ using magnetic resonance imaging (MRI) at post-operative days 7 and 14. Bladder sections excised at days 7, 14, 28, and 56 post-operation Samples were assessed by H&E and Masson's trichrome stains. Urothelial differentiation was analyzed using cytokeratin AE1/AE3, and uroplakin III (UPIII). In addition, quantitative and qualitative evaluations of neutrophils, mast cells, eosinophils, and macrophages were performed using anti-myeloperoxidase, Alcian blue, Giemsa stain, and anti-CD68 staining methods, respectively. Four-layer SIS was consistently impermeable as evidenced by the absence of intravesical administered gadolinium with diethylenetriaminepentacetate (Gd-DTPA) contrast signal in peripheral regions of augmented bladders compared with single-layer SIS bioscaffold. Elevated and sustained eosinophil and neutrophil infiltrations were prominent in four-layered SIS-augmented bladders compared with single-layer SIS with comparable impermeability. Delayed but consistent urothelial regeneration and differentiation were observed in four-layer SIS-augmented bladders; and urothelial differentiation was observed at day 56 post-augmentation. In conclusion, four-layer SIS enacts an elevated inflammatory response along with extended urothelial regeneration. Four-layer SIS may activate a different but yet to be identified mechanism for inflammatory responses. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 107B: 1960-1969, 2019.

Who, where, and why are patients lost to follow-up? A 20-year study of bladder exstrophy patients at a single institution.

INTRODUCTION: Individuals with bladder and cloacal exstrophy are at increased risk for kidney disease, renal failure, and bladder complications. Given the social implications and sensitive nature of the disease, these patients are also at risk for psychosocial problems. Lack of regular medical follow-up visits may pose serious risks to their long-term health status. The aim of this study is determine what factors place an affected individual at risk for limited long term follow up. MATERIALS AND METHODS: We identified all patients with bladder or cloacal exstrophy seen by the pediatric urology department at the Oklahoma University Health Sciences Center (OUHSC) between January 1996 and August 2016. Patient data included demographics, insurance coverage, distance from patient's home to the clinic, medical and surgical history, and the date of their last clinic visit. Two groups for comparison were (1) those that had been seen within the last 2 years, and (2) those that were counted as failing to maintain follow-up because 2 or more years had passed since their last clinic visit. These groups were compared using the Student t-test, the chi-square test, or the Fisher exact test and p < 0.05 was treated as significant for the purposes of discussion. RESULTS AND DISCUSSION: Ninety-one patients with bladder or cloacal exstrophy were seen by the pediatric urology department between January 1996 and August 2016. Of the 91 patients, 24 left the clinic for known reasons thus leaving 67 patients that were considered for analyses: 51 had been seen within the last 2 years while 16 were counted as lost to follow-up. These two groups (active and lost to follow-up) did not differ significantly for age at last clinic visit, distance between family's home and clinic, history of bladder reconstruction, sex, or insurance status. There was a significant difference between the two groups in the medical complexity of their condition. The group active in urological care had more patients with cloacal exstrophy and additional anomalies than the group lost to follow-up. CONCLUSIONS: Patients with bladder exstrophy and cloacal exstrophy are less likely to maintain annual follow-up visits with their urologist if they have a simpler diagnosis requiring fewer surgical interventions. For patients with exstrophy, regular clinic visits prioritizing education and psychosocial support may prevent hospitalizations, emergency interventions, and poor overall health outcomes. To maintain contact with the medical team and promote optimal health outcomes, a social worker or care coordinator/educator may play an integral part in addressing the unique needs of this population.

Reduced urothelial regeneration in rat bladders augmented with permeable porcine small intestinal submucosa assessed by magnetic resonance imaging.

Augmentation enterocystoplasty remains the gold standard surgical bladder reconstruction procedure to increase the capacity and compliance of dysfunctional bladders. Since the use of the patient's intestine has severe risks of complications, alternative biodegradable matrices have been explored. Porcine small intestinal submucosa (SIS) has gained immense interests in bladder reconstruction due to its favorable properties. However, trials have shown inconsistent regeneration with SIS, attributed to the heterogeneity in microstructures and mechanical properties. We hypothesize that uneven SIS permeability to urine is a factor responsible for the inconsistency. We measured permeability to urine in situ using a contrast enhanced-magnetic resonance imaging (MRI), and evaluated urothelium regeneration using immunohistochemical staining of urothelial cell markers in SIS-augmented rat bladders. Results showed significant differences in permeability among SIS-augmented rat bladders. Commercial SIS scaffolds were then categorized into nonleaky and leaky groups based on MRI results. Hematoxylin and eosin staining showed higher numbers of inflammatory cells in leaky SIS on day 14 relative to nonleaky SIS. In addition, trichrome staining showed major changes in the distribution of collagen on day 28 between SIS-augmented bladder groups. Furthermore, expressions of urothelium-associated markers (cytokeratins AE1/AE3, claudin 4, and uroplakin III) were completed in bladders augmented with nonleaky SIS, whereas limited urothelial differentiation was noticed in leaky SIS-augmented bladders at post-augmentative day 14. These results show that scaffold permeability to urine may be responsible for variations in regenerative capacity of porcine SIS. Applications of MRI technique will be helpful to understand a relationship between biomaterial property and regenerative capacity. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 1778-1787, 2018.

Analysis of Factors Associated with Patient or Caregiver Regret following Surgery for Fecal Incontinence.

PURPOSE: Malone antegrade continence enema has been a successful and widely used procedure for achieving fecal continence in children. We present data on the previously uninvestigated issue of patient and caregiver regret following surgery for intractable constipation and fecal incontinence. MATERIALS AND METHODS: We reviewed all patients undergoing antegrade continence enema or cecostomy creation at a single institution between 2006 and 2016. Patients and caregivers were assessed for decisional regret using the Decisional Regret Scale. Results were correlated with demographics, surgical outcomes and complications. RESULTS: A total of 81 responses (49 caregivers and 32 patients) were obtained. Mean followup was 49 months. Decisional regret was noted in 43 subjects (53%), including mild regret in 38 (47%) and moderate to severe regret in 5 (6%). No statistical difference in regret was noted based on gender, complications or performance of concomitant procedures. On regression analysis incontinence was strongly associated with decisional regret (OR 4.4, 95% CI 1.1-18.1, p <0.001) and regret increased as age at surgery increased, particularly when patients were operated on at age 13 to 15 years (OR 2.6, 95% CI 1.0-6.4 for age 13 years; OR 2.9, 95% CI 1.1-7.8 for age 14 years; OR 3.1, 95% CI 1.1-8.8 for age 15 years). CONCLUSIONS: This is the first known study describing decisional regret following surgery for fecal incontinence. Surgical factors aimed at achieving continence may be effective in decreasing postoperative regret. The finding of increased regret in teenage patients compared to younger children should be shared with families since it may impact the age at which surgery is pursued.

"Watering Can" Ureterocele Puncture Technique Leads to Decreased Rates of De Novo Vesicoureteral Reflux and Subsequent Surgery With Durable Results.

OBJECTIVE: To assess the outcomes of "watering can" ureterocele puncture (WCP), a technique previously associated with decreased incidence of de novo vesicoureteral reflux (VUR), as a durable option for management of ureteroceles and to determine the need for subsequent surgery for VUR following watering can puncture. MATERIALS AND METHODS: We retrospectively reviewed records of 55 consecutive endoscopic ureterocele procedures performed at our institution from 1999 to 2015. The WCP was performed using a holmium laser fiber to make 10-20 puncture holes through the ureterocele. Follow-up data were collected on infection, de novo VUR in the affected renal moiety and the need for further treatment and surgery. RESULTS: Of 55 patients who underwent endoscopic ureterocele management, 34 underwent WCP and 21 patients underwent either incision or puncture. Median follow-up was 3.4 and 2.8 years in the incision and puncture groups, respectively. Both groups had similar rates of ureterocele decompression (88% vs 90%; P >.05) and improvement in hydronephrosis (82% vs 81%; P >.05). The WCP group had a significantly decreased rate of de novo VUR (32% vs 67%; P <.05) and of subsequent surgery due to de novo VUR (38% vs 71%; P <.05). The average grade of de novo VUR was lower in the WCP group (1.4 vs 2.8; P <.05). CONCLUSION: Our study shows that the endoscopic WCP successfully decompresses the obstructing ureterocele and results in a decreased incidence of de novo VUR and ultimately in fewer invasive procedures for the patient. This update demonstrates the durable outcomes of this novel technique.

A Feasibility Study to Determine Whether Clinical Contrast Enhanced Magnetic Resonance Imaging can Detect Increased Bladder Permeability in Patients with Interstitial Cystitis.

PURPOSE: Interstitial cystitis/bladder pain syndrome is a bladder pain disorder associated with voiding symptomatology and other systemic chronic pain disorders. Currently diagnosing interstitial cystitis/bladder pain syndrome is complicated as patients present with a wide range of symptoms, physical examination findings and clinical test responses. One hypothesis is that interstitial cystitis symptoms arise from increased bladder permeability to urine solutes. This study establishes the feasibility of using contrast enhanced magnetic resonance imaging to quantify bladder permeability in patients with interstitial cystitis. MATERIALS AND METHODS: Permeability alterations in bladder urothelium were assessed by intravesical administration of the magnetic resonance imaging contrast agent Gd-DTPA (Gd-diethylenetriaminepentaacetic acid) in a small cohort of patients. Magnetic resonance imaging signal intensity in patient and control bladders was compared regionally and for entire bladders. RESULTS: Quantitative assessment of magnetic resonance imaging signal intensity indicated a significant increase in signal intensity in anterior bladder regions compared to posterior regions in patients with interstitial cystitis (p <0.01) and significant increases in signal intensity in anterior bladder regions (p <0.001). Kurtosis (shape of probability distribution) and skewness (measure of probability distribution asymmetry) were associated with contrast enhancement in total bladders in patients with interstitial cystitis vs controls (p <0.05). Regarding symptomatology interstitial cystitis cases differed significantly from controls on the SF-36®, PUF (Pelvic Pain and Urgency/Frequency) and ICPI (Interstitial Cystitis Problem Index) questionnaires with no overlap in the score range in each group. ICSI (Interstitial Cystitis Symptom Index) differed significantly but with a slight overlap in the range of scores. CONCLUSIONS: Data suggest that contrast enhanced magnetic resonance imaging provides an objective, quantifiable measurement of bladder permeability that could be used to stratify bladder pain patients and monitor therapy.

Bladder Function After Fetal Surgery for Myelomeningocele.

BACKGROUND: A substudy of the Management of Myelomeningocele Study evaluating urological outcomes was conducted. METHODS: Pregnant women diagnosed with fetal myelomeningocele were randomly assigned to either prenatal or standard postnatal surgical repair. The substudy included patients randomly assigned after April 18, 2005. The primary outcome was defined in their children as death or the need for clean intermittent catheterization (CIC) by 30 months of age characterized by prespecified criteria. Secondary outcomes included bladder and kidney abnormalities observed by urodynamics and renal/bladder ultrasound at 12 and 30 months, which were analyzed as repeated measures. RESULTS: Of the 115 women enrolled in the substudy, the primary outcome occurred in 52% of children in the prenatal surgery group and 66% in the postnatal surgery group (relative risk [RR]: 0.78; 95% confidence interval [CI]: 0.57-1.07). Actual rates of CIC use were 38% and 51% in the prenatal and postnatal surgery groups, respectively (RR: 0.74; 95% CI: 0.48-1.12). Prenatal surgery resulted in less trabeculation (RR: 0.39; 95% CI: 0.19-0.79) and fewer cases of open bladder neck on urodynamics (RR: 0.61; 95% CI: 0.40-0.92) after adjustment by child's gender and lesion level. The difference in trabeculation was confirmed by ultrasound. CONCLUSIONS: Prenatal surgery did not significantly reduce the need for CIC by 30 months of age but was associated with less bladder trabeculation and open bladder neck. The implications of these findings are unclear now, but support the need for long-term urologic follow-up of patients with myelomeningocele regardless of type of surgical repair.

Reliance of preoperative scrotal examination versus final operative findings in the evaluation of non-palpable testes.

OBJECTIVE: The current study evaluates whether the preoperative scrotal examination in children with non-palpable testes is sufficient in all cases or if laparoscopy is necessary to confirm the examination findings. Are the findings different amongst physicians depending on their level of experience? MATERIALS AND METHODS: This retrospective study was done between October 2009 and May 2013. Children with non-palpable testes underwent an examination under anesthesia prior to surgery to feel for a testis or nubbin, followed by a diagnostic laparoscopy to validate the scrotal examination. The test was considered correct if the laparoscopic findings supported the scrotal examination. It was considered incorrect if laparoscopy revealed a different finding. RESULTS: A total of 74 testes were evaluated. All patients underwent examination under anesthesia by the surgeon and senior resident. The findings were recorded separately. Despite careful examination by experienced surgeons under anesthesia, the scrotal examination was incorrect in 14 patients. Four viable testes would have been missed if laparoscopy had not been performed. CONCLUSION: Laparoscopy should be considered in case of palpable scrotal nubbins to ensure no testis is left within the abdominal cavity.

Mental health and parenting characteristics of caregivers of children with spina bifida.

INTRODUCTION: Within the chronic medical illness literature, associations exist between caring for an affected child and parent mental health. The few studies examining both mothers and fathers provide mixed results. The purpose of this study is to examine associations between caregiver anxiety, depression, and parenting variables in caregivers of youth with SB as these relate to marital status, age, education, household income, work status, and child's severity of SB. OBJECTIVE: The aim of this study is to examine associations between anxiety, depression, and parenting variables in caregivers of youth with spina bifida and how they relate to demographic and disease variables. Exploratory analyses examined the relationship between participation in support activities and depressive and anxious symptomatology and parenting characteristics. STUDY DESIGN: Eighty-four primary caregivers (49 mothers) of 51 youth with spina bifida completed measures of depressive and anxious symptomology, parenting stress, parent overprotection, and perceived child vulnerability. RESULTS: There were differences between mothers and fathers on several parenting characteristics; however, these were related more to marital status and employment than to gender of the caretaker per se. In the 33 married/remarried couples for whom both spouses participated, stress for the mothers was correlated with stress for the fathers. This correlation was strongest in the 12 married couples in which the mother works. Higher perceived vulnerability scores were reported in parents of SB patients in the younger age group, especially preschoolers (0-4 years). Parents of children with shunts reported more anxiety, depression and perceived child vulnerability. Both male and female caregivers of younger children reported significantly higher protectiveness scores. Involvement in recreational activities with other families affected by SB was associated with more positive parenting characteristics for mothers. DISCUSSION: Stress and protectiveness were found to be positively correlated (r > 0.6); depression, anxiety, and perceived vulnerability were not (0.3 < r < -0.3). Overall, mothers reported more stress and anxiety than fathers. Higher perceived vulnerability scores were reported in parents of SB patients in the younger age group, especially preschoolers (0-4 years). Parents of children with shunts reported more anxiety, depression and perceived child vulnerability. Both male and female caregivers of younger children reported significantly higher protectiveness scores compared to caregivers of older children. Involvement in recreational activities with other families affected by SB was associated with more positive parenting characteristics for mothers. There were differences between mothers and fathers on several parenting characteristics; however, these were related more to marital status and employment than to gender of the caretaker per se. Limitations to the current study qualify our results and conclusions. Associations do not prove causation. Our measure of parent protection had a lower Cronbach's alpha score for male caregivers (0.68) than female caregivers (0.83), consistent with an examination of the factor structure of the PPS that found the measure to have a poor factor structure and limited reliability in samples with a chronic medical condition. CONCLUSION: Anxiety, depression, and parenting characteristics were differentially impacted by variables such as caregiver and child age, shunt status, and employment status/income for parents of youth with SB. Interventions to improve parenting skills and mental health of these caregivers can be designed to target specific needs of parents. Groups such as the Greater Oklahoma Disabled Sports Association (GODSA) offer real-world support to improve the lives of caregivers of SB children, and should be studied further to optimize outcomes for children.

Temporal expression of hyaluronic acid and hyaluronic acid receptors in a porcine small intestinal submucosa-augmented rat bladder regeneration model.

INTRODUCTION: Hyaluronic acid (HA), a non-sulfated glycosaminoglycan, is an essential component of the extracellular matrix (ECM). Since HA is involved in many phases of wound healing and may play a key role in tissue repair and regeneration, this study was intended to understand temporal and spatial expression of HA and HA receptors (HARs) during the course of bladder regeneration in rats. MATERIALS AND METHODS: Sprague-Dawley rats were subjected to partial cystectomy followed by augmentation with porcine small intestinal submucosal (SIS) prepared from distal sections of the small intestine. SIS-augmented bladders were harvested between postoperative days 2 and 56. RESULTS: Bladder regeneration proceeded without complications. All augmented bladders had complete urothelial lining and smooth muscle bundles by day 56 post-augmentation. Temporal and spatial distributions of HA and HARs were studied by immunohistochemistry in regenerating bladders. The strongest HA immunoreactivity was observed in the ECM on postoperative days 28 and 56. Cluster of differentiation 44 (CD44) immunoreactivity was detected in the cytoplasm of urothelial cells on day 56; and LYVE-1 immunoreactivity was exclusively limited to lymphatic vessels on days 28 and 56. CONCLUSIONS: We demonstrated that HA was synthesized throughout the course of bladder wound healing and regeneration; and HA deposition coincided with urothelial differentiation. Expression of CD44 and LYVE-1 followed the same temporal pattern as HA deposition. Therapeutic modalities through local delivery of exogenous HA to improve the outcome of SIS-mediated bladder regeneration might need to be coordinated with HAR expression in order to achieve maximal regenerative responses as opposed to fibrosis.

Increased bladder permeability in interstitial cystitis/painful bladder syndrome.

The definition of interstitial cystitis (IC) has evolved over the years from being a well-defined entity characterized by diagnostic lesion (Hunner's ulcer) in the urothelium to a clinical diagnosis by exclusion (painful bladder syndrome (PBS). Although the etiology is unknown, a central theme has been an association with increased permeability of the bladder. This article reviews the evidence for increased permeability being important to the symptoms of IC/PBS and in treating the disorder. Recent work showing cross-communication among visceral organs is also reviewed to provide a basis for understanding IC/PBS as a systemic disorder of a complex, interconnected system consisting of the bladder, bowel and other organs, nerves, cytokine-responding cells and the nervous system.

Biomatrices for bladder reconstruction.

There is a demand for tissue engineering of the bladder needed by patients who experience a neurogenic bladder or idiopathic detrusor overactivity. To avoid complications from augmentation cystoplasty, the field of tissue engineering seeks optimal scaffolds for bladder reconstruction. Naturally derived biomaterials as well as synthetic and natural polymers have been explored as bladder substitutes. To improve regenerative properties, these biomaterials have been conjugated with functional molecules, combined with nanotechology, or seeded with exogenous cells. Although most studies reported complete and functional bladder regeneration in small-animal models, results from large-animal models and human clinical trials varied. For functional bladder regeneration, procedures for biomaterial fabrication, incorporation of biologically active agents, introduction of nanotechnology, and application of stem-cell technology need to be standardized. Advanced molecular and medical technologies such as next generation sequencing and magnetic resonance imaging can be introduced for mechanistic understanding and non-invasive monitoring of regeneration processes, respectively.

Antimicrobial prophylaxis for children with vesicoureteral reflux.

BACKGROUND: Children with febrile urinary tract infection commonly have vesicoureteral reflux. Because trial results have been limited and inconsistent, the use of antimicrobial prophylaxis to prevent recurrences in children with reflux remains controversial. METHODS: In this 2-year, multisite, randomized, placebo-controlled trial involving 607 children with vesicoureteral reflux that was diagnosed after a first or second febrile or symptomatic urinary tract infection, we evaluated the efficacy of trimethoprim-sulfamethoxazole prophylaxis in preventing recurrences (primary outcome). Secondary outcomes were renal scarring, treatment failure (a composite of recurrences and scarring), and antimicrobial resistance. RESULTS: Recurrent urinary tract infection developed in 39 of 302 children who received prophylaxis as compared with 72 of 305 children who received placebo (relative risk, 0.55; 95% confidence interval [CI], 0.38 to 0.78). Prophylaxis reduced the risk of recurrences by 50% (hazard ratio, 0.50; 95% CI, 0.34 to 0.74) and was particularly effective in children whose index infection was febrile (hazard ratio, 0.41; 95% CI, 0.26 to 0.64) and in those with baseline bladder and bowel dysfunction (hazard ratio, 0.21; 95% CI, 0.08 to 0.58). The occurrence of renal scarring did not differ significantly between the prophylaxis and placebo groups (11.9% and 10.2%, respectively). Among 87 children with a first recurrence caused by Escherichia coli, the proportion of isolates that were resistant to trimethoprim-sulfamethoxazole was 63% in the prophylaxis group and 19% in the placebo group. CONCLUSIONS: Among children with vesicoureteral reflux after urinary tract infection, antimicrobial prophylaxis was associated with a substantially reduced risk of recurrence but not of renal scarring. (Funded by the National Institute of Diabetes and Digestive and Kidney Diseases and others; RIVUR ClinicalTrials.gov number, NCT00405704.).

Understanding roles of porcine small intestinal submucosa in urinary bladder regeneration: identification of variable regenerative characteristics of small intestinal submucosa.

Neuropathic bladders are the result from damages to the central or peripheral nervous system, and ultimately may require surgical reconstruction to increase bladder volumes and to reduce the risk of damages to the kidneys. Surgical reconstruction through bladder augmentation has traditionally been practiced using a segment of the ileum, colon, or stomach from the patient through enterocystoplasty. However, the use of gastrointestinal segments can lead to serious adverse consequences. Porcine small intestinal submucosa (SIS), a xenogeneic, acellular, biocompatable, biodegradable, and collagen-based bioscaffold is best known to encourage bladder regeneration without ex vivo cell seeding before implantation in various experimental and preclinical animal models. Although it has been demonstrated that SIS supports bladder cell growth in vitro, and SIS-regenerated bladders are histologically and functionally indistinguishable from normal functional tissues, clinical utilization of SIS for bladder augmentation has been hampered by inconsistent preclinical results. Several variables in SIS, such as the age of pigs, the region of the small intestine, and method of sterilization, can have different physical properties, biochemical characteristics, inflammatory cell infiltration, and regenerative capacity due to cellular responses in vitro and in vivo. These parameters are particularly important for bladder regeneration due to its specific biological function in urine storage. Clinical application of SIS for surgical bladder reconstruction may require graft materials to be prepared from a specific region of the small intestine, or to be further formulated or processed to provide uniform physical and biochemical properties for consistent, complete, and functional bladder regeneration.

Linking γ-aminobutyric acid A receptor to epidermal growth factor receptor pathways activation in human prostate cancer.

Neuroendocrine (NE) differentiation has been attributed to the progression of castration-resistant prostate cancer (CRPC). Growth factor pathways including the epidermal growth factor receptor (EGFR) signaling have been implicated in the development of NE features and progression to a castration-resistant phenotype. However, upstream molecules that regulate the growth factor pathway remain largely unknown. Using androgen-insensitive bone metastasis PC-3 cells and androgen-sensitive lymph node metastasis LNCaP cells derived from human prostate cancer (PCa) patients, we demonstrated that γ-aminobutyric acid A receptor (GABA(A)R) ligand (GABA) and agonist (isoguvacine) stimulate cell proliferation, enhance EGF family members expression, and activate EGFR and a downstream signaling molecule, Src, in both PC-3 and LNCaP cells. Inclusion of a GABA(A)R antagonist, picrotoxin, or an EGFR tyrosine kinase inhibitor, Gefitinib (ZD1839 or Iressa), blocked isoguvacine and GABA-stimulated cell growth, trans-phospohorylation of EGFR, and tyrosyl phosphorylation of Src in both PCa cell lines. Spatial distributions of GABAAR α1 and phosphorylated Src (Tyr416) were studied in human prostate tissues by immunohistochemistry. In contrast to extremely low or absence of GABA(A)R α1-positive immunoreactivity in normal prostate epithelium, elevated GABA(A)R α1 immunoreactivity was detected in prostate carcinomatous glands. Similarly, immunoreactivity of phospho-Src (Tyr416) was specifically localized and limited to the nucleoli of all invasive prostate carcinoma cells, but negative in normal tissues. Strong GABAAR α1 immunoreactivity was spatially adjacent to the neoplastic glands where strong phospho-Src (Tyr416)-positive immunoreactivity was demonstrated, but not in adjacent to normal glands. These results suggest that the GABA signaling is linked to the EGFR pathway and may work through autocrine or paracine mechanism to promote CRPC progression.