Ras/ERK and PI3K/AKT signaling differentially regulate oncogenic ERG mediated transcription in prostate cells.

The TMPRSS2/ERG gene rearrangement occurs in 50% of prostate tumors and results in expression of the transcription factor ERG, which is normally silent in prostate cells. ERG expression promotes prostate tumor formation and luminal epithelial cell fates when combined with PI3K/AKT pathway activation, however the mechanism of synergy is not known. In contrast to luminal fates, expression of ERG alone in immortalized normal prostate epithelial cells promotes cell migration and epithelial to mesenchymal transition (EMT). Migration requires ERG serine 96 phosphorylation via endogenous Ras/ERK signaling. We found that a phosphomimetic mutant, S96E ERG, drove tumor formation and clonogenic survival without activated AKT. S96 was only phosphorylated on nuclear ERG, and differential recruitment of ERK to a subset of ERG-bound chromatin associated with ERG-activated, but not ERG-repressed genes. S96E did not alter ERG genomic binding, but caused a loss of ERG-mediated repression, EZH2 binding and H3K27 methylation. In contrast, AKT activation altered the ERG cistrome and promoted expression of luminal cell fate genes. These data suggest that, depending on AKT status, ERG can promote either luminal or EMT transcription programs, but ERG can promote tumorigenesis independent of these cell fates and tumorigenesis requires only the transcriptional activation function.

Toll-like receptor 4 signaling activates ERG function in prostate cancer and provides a therapeutic target.

The TMPRSS2-ERG gene fusion and subsequent overexpression of the ERG transcription factor occurs in ∼50% of prostate tumors, making it the most common abnormality of the prostate cancer genome. While ERG has been shown to drive tumor progression and cancer-related phenotypes, as a transcription factor it is difficult to target therapeutically. Using a genetic screen, we identified the toll-like receptor 4 (TLR4) signaling pathway as important for ERG function in prostate cells. Our data confirm previous reports that ERG can transcriptionally activate TLR4 gene expression; however, using a constitutively active ERG mutant, we demonstrate that the critical function of TLR4 signaling is upstream, promoting ERG phosphorylation at serine 96 and ERG transcriptional activation. The TLR4 inhibitor, TAK-242, attenuated ERG-mediated migration, clonogenic survival, target gene activation and tumor growth. Together these data indicate a mechanistic basis for inhibition of TLR4 signaling as a treatment for ERG-positive prostate cancer.

Antitumor Activity and Mechanistic Characterization of APE1/Ref-1 Inhibitors in Bladder Cancer.

Bladder cancer is the ninth most common cause of cancer-related deaths worldwide. Although cisplatin is used routinely in treating bladder cancer, refractory disease remains lethal for many patients. The recent addition of immunotherapy has improved patient outcomes; however, a large cohort of patients does not respond to these treatments. Therefore, identification of innovative molecular targets for bladder cancer is crucial. Apurinic/apyrimidinic endonuclease 1/redox factor-1 (APE1/Ref-1) is a multifunctional protein involved in both DNA repair and activation of transcription factors through reduction-oxidation (redox) regulation. High APE1/Ref-1 expression is associated with shorter patient survival time in many cancer types. In this study, we found high APE1/Ref-1 expression in human bladder cancer tissue relative to benign urothelium. Inhibition of APE1/Ref-1 redox signaling using APE1/Ref-1-specific inhibitors attenuates bladder cancer cell proliferation in monolayer, in three-dimensional cultures, and in vivo. This inhibition corresponds with an increase in apoptosis and decreased transcriptional activity of NF-κB and STAT3, transcription factors known to be regulated by APE1/Ref-1, resulting in decreased expression of downstream effectors survivin and Cyclin D1 in vitro and in vivo. We also demonstrate that in vitro treatment of bladder cancer cells with APE1/Ref-1 redox inhibitors in combination with standard-of-care chemotherapy cisplatin is more effective than cisplatin alone at inhibiting cell proliferation. Collectively, our data demonstrate that APE1/Ref-1 is a viable drug target for the treatment of bladder cancer, provide a mechanism of APE1/Ref-1 action in bladder cancer cells, and support the use of novel redox-selective APE1/Ref-1 inhibitors in clinical studies. SIGNIFICANCE: This work identifies a critical mechanism for APE1/Ref-1 in bladder cancer growth and provides compelling preclinical data using selective redox activity inhibitors of APE1/Ref-1 in vitro and in vivo.

APE1/Ref-1 redox-specific inhibition decreases survivin protein levels and induces cell cycle arrest in prostate cancer cells.

A key feature of prostate cancer progression is the induction and activation of survival proteins, including the Inhibitor of Apoptosis (IAP) family member survivin. Apurinic/apyrimidinic endonuclease 1/redox effector factor 1 (APE1/Ref-1) is a multifunctional protein that is essential in activating oncogenic transcription factors. Because APE1/Ref-1 is expressed and elevated in prostate cancer, we sought to characterize APE1/Ref-1 expression and activity in human prostate cancer cell lines and determine the effect of selective reduction-oxidation (redox) function inhibition on prostate cancer cells in vitro and in vivo. Due to the role of oncogenic transcriptional activators NFĸB and STAT3 in survivin protein expression, and APE1/Ref-1 redox activity regulating their transcriptional activity, we assessed selective inhibition of APE1/Ref-1's redox function as a novel method to halt prostate cancer cell growth and survival. Our study demonstrates that survivin and APE1/Ref-1 are significantly higher in human prostate cancer specimens compared to noncancerous controls and that APE1/Ref-1 redox-specific inhibition with small molecule inhibitor, APX3330 and a second-generation inhibitor, APX2009, decreases prostate cancer cell proliferation and induces cell cycle arrest. Inhibition of APE1/Ref-1 redox function significantly reduced NFĸB transcriptional activity, survivin mRNA and survivin protein levels. These data indicate that APE1/Ref-1 is a key regulator of survivin and a potentially viable target in prostate cancer.

The common parasite Toxoplasma gondii induces prostatic inflammation and microglandular hyperplasia in a mouse model.

BACKGROUND: Inflammation is the most prevalent and widespread histological finding in the human prostate, and associates with the development and progression of benign prostatic hyperplasia and prostate cancer. Several factors have been hypothesized to cause inflammation, yet the role each may play in the etiology of prostatic inflammation remains unclear. This study examined the possibility that the common protozoan parasite Toxoplasma gondii induces prostatic inflammation and reactive hyperplasia in a mouse model. METHODS: Male mice were infected systemically with T. gondii parasites and prostatic inflammation was scored based on severity and focality of infiltrating leukocytes and epithelial hyperplasia. We characterized inflammatory cells with flow cytometry and the resulting epithelial proliferation with bromodeoxyuridine (BrdU) incorporation. RESULTS: We found that T. gondii infects the mouse prostate within the first 14 days of infection and can establish parasite cysts that persist for at least 60 days. T. gondii infection induces a substantial and chronic inflammatory reaction in the mouse prostate characterized by monocytic and lymphocytic inflammatory infiltrate. T. gondii-induced inflammation results in reactive hyperplasia, involving basal and luminal epithelial proliferation, and the exhibition of proliferative inflammatory microglandular hyperplasia in inflamed mouse prostates. CONCLUSIONS: This study identifies the common parasite T. gondii as a new trigger of prostatic inflammation, which we used to develop a novel mouse model of prostatic inflammation. This is the first report that T. gondii chronically encysts and induces chronic inflammation within the prostate of any species. Furthermore, T. gondii-induced prostatic inflammation persists and progresses without genetic manipulation in mice, offering a powerful new mouse model for the study of chronic prostatic inflammation and microglandular hyperplasia.

An Interaction with Ewing's Sarcoma Breakpoint Protein EWS Defines a Specific Oncogenic Mechanism of ETS Factors Rearranged in Prostate Cancer.

More than 50% of prostate tumors have a chromosomal rearrangement resulting in aberrant expression of an oncogenic ETS family transcription factor. However, mechanisms that differentiate the function of oncogenic ETS factors expressed in prostate tumors from non-oncogenic ETS factors expressed in normal prostate are unknown. Here, we find that four oncogenic ETS (ERG, ETV1, ETV4, and ETV5), and no other ETS, interact with the Ewing's sarcoma breakpoint protein, EWS. This EWS interaction was necessary and sufficient for oncogenic ETS functions including gene activation, cell migration, clonogenic survival, and transformation. Significantly, the EWS interacting region of ERG has no homology with that of ETV1, ETV4, and ETV5. Therefore, this finding may explain how divergent ETS factors have a common oncogenic function. Strikingly, EWS is fused to various ETS factors by the chromosome translocations that cause Ewing's sarcoma. Therefore, these findings link oncogenic ETS function in both prostate cancer and Ewing's sarcoma.

Coordinated induction of cell survival signaling in the inflamed microenvironment of the prostate.

PURPOSE: Both prostate cancer and benign prostatic hyperplasia are associated with inflammatory microenvironments. Inflammation is damaging to tissues, but it is unclear how the inflammatory microenvironment protects specialized epithelial cells that function to proliferate and repair the tissue. The objective of this study is to characterize the cell death and cell survival response of the prostatic epithelium in response to inflammation. METHODS: We assessed induction of cell death (TNF, TRAIL, TWEAK, FasL) and cell survival factors (IGFs, hedgehogs, IL-6, FGFs, and TGFs) in inflamed and control mouse prostates by ELISA. Cell death mechanisms were determined by immunoblotting and immunofluorescence for cleavage of caspases and TUNEL. Survival pathway activation was assessed by immunoblotting and immunofluorescence for Mcl-1, Bcl-2, Bcl-XL, and survivin. Autophagy was determined by immunoblotting and immunofluorescence for free and membrane associated light chain 3 (LC-3). RESULTS: Cleavage of all four caspases was significantly increased during the first 2 days of inflammation, and survival protein expression was substantially increased subsequently, maximizing at 3 days. By 5 days of inflammation, 50% of prostatic epithelial cells expressed survivin. Autophagy was also evident during the recovery phase (3 days). Finally, immunofluorescent staining of human specimens indicates strong activation of survival proteins juxtaposed to inflammation in inflamed prostate specimens. CONCLUSIONS: The prostate responds to deleterious inflammation with induction of cell survival mechanisms, most notably survivin and autophagy, demonstrating a coordinated induction of survival factors that protects and expands a specialized set of prostatic epithelial cells as part of the repair and recovery process during inflammation.

Phosphatase and Tensin Homologue: Novel Regulation by Developmental Signaling.

Phosphatase and tensin homologue (PTEN) is a critical cell endogenous inhibitor of phosphoinositide signaling in mammalian cells. PTEN dephosphorylates phosphoinositide trisphosphate (PIP3), and by so doing PTEN has the function of negative regulation of Akt, thereby inhibiting this key intracellular signal transduction pathway. In numerous cell types, PTEN loss-of-function mutations result in unopposed Akt signaling, producing numerous effects on cells. Numerous reports exist regarding mutations in PTEN leading to unregulated Akt and human disease, most notably cancer. However, less is commonly known about nonmutational regulation of PTEN. This review focuses on an emerging literature on the regulation of PTEN at the transcriptional, posttranscriptional, translational, and posttranslational levels. Specifically, a focus is placed on the role developmental signaling pathways play in PTEN regulation; this includes insulin-like growth factor, NOTCH, transforming growth factor, bone morphogenetic protein, wnt, and hedgehog signaling. The regulation of PTEN by developmental mediators affects critical biological processes including neuronal and organ development, stem cell maintenance, cell cycle regulation, inflammation, response to hypoxia, repair and recovery, and cell death and survival. Perturbations of PTEN regulation consequently lead to human diseases such as cancer, chronic inflammatory syndromes, developmental abnormalities, diabetes, and neurodegeneration.

Characterization of autoimmune inflammation induced prostate stem cell expansion.

BACKGROUND: The presence of inflammation in prostate cancer (PCa) and benign prostate hyperplasia (BPH) has been well described but the cellular mechanisms by which inflammation modulates the prostate are currently unclear. Prostate stem cells (PSC) not only maintain prostate homeostasis but also are considered to be the cell of origin of PCa and an important contributor to BPH. However, the impact of inflammation on PSC is not well understood. Therefore, we initiated studies to evaluate the effect of inflammation on PSC. METHOD: Ovalbumin specific CD8(+) T cells were intravenously delivered to intact and castrated prostate ovalbumin expressing transgenic-3 (POET-3) mice to induce inflammation. Lin (CD45/CD31)(-) Sca1(+) CD49f(+) cells (LSC) and progenitor cells within LSC were determined by flow cytometry. Sorted LSC were subjected to a prostate sphere forming assay to evaluate PSC clonal propagation, proliferation, immediate differentiation, and self-renewal ability. Density of individual spheres was measured by a cantilever-based resonator weighing system. Morphology and characterization of prostate spheres was determined by hematoxylin and eosin (H&E) staining and immunohistochemistry (IHC). Finally, immediate PSC differentiation in sphere formation was determined by immunofluorescence for epithelial cytokeratin markers cytokeratin (CK) 5 and CK8. RESULT: Data presented here demonstrate a significant expansion of the proliferative (BrdU(+) ) LSC population, including CK5(+) , p63(+) , CK18(+) cells, as well as intermediate cells (CK5(+) /CK8(+) ) in inflamed prostates. Histological images reveal that PSC from inflamed prostates produce significantly larger spheres, indicating that the enhanced proliferation observed in LSC is sustained in vitro in the absence of inflammatory mediators. In addition, cultures from inflamed PSC yielded increased number of tubule-like spheres. These tube-like spheres grown from PSCs isolated from inflamed mice exhibited stratification of a CK8(+) luminal-like layer and a CK5(+) basal-like layer. Notably, the numbers of spheres formed by inflamed and non-inflamed PSC were equal, suggesting that even though proliferation is enhanced by inflammation, the homeostatic level of PSC is maintained. CONCLUSION: Induction of inflammation promotes PSC expansion and immediate differentiation through highly proliferative progenitor cells while the homeostasis of PSC is maintained.

Expansion of prostate epithelial progenitor cells after inflammation of the mouse prostate.

Prostatic inflammation is a nearly ubiquitous pathological feature observed in specimens from benign prostate hyperplasia and prostate cancer patients. The microenvironment of the inflamed prostate is highly reactive, and epithelial hyperplasia is a hallmark feature of inflamed prostates. How inflammation orchestrates epithelial proliferation as part of its repair and recovery action is not well understood. Here, we report that a novel epithelial progenitor cell population is induced to expand during inflammation. We used sphere culture assays, immunofluorescence, and flow cytometry to show that this population is increased in bacterially induced inflamed mouse prostates relative to naïve control prostates. We confirmed from previous reports that this population exclusively possesses the ability to regrow entire prostatic structures from single cell culture using renal grafts. In addition, putative progenitor cells harvested from inflamed animals have greater aggregation capacity than those isolated from naïve control prostates. Expansion of this critical cell population requires IL-1 signaling, as IL-1 receptor 1-null mice exhibit inflammation similar to wild-type inflamed animals but exhibit significantly reduced progenitor cell proliferation and hyperplasia. These data demonstrate that inflammation promotes hyperplasia in the mouse prostatic epithelium by inducing the expansion of a selected epithelial progenitor cell population in an IL-1 receptor-dependent manner. These findings may have significant impact on our understanding of how inflammation promotes proliferative diseases such as benign prostatic hyperplasia and prostate cancer, both of which depend on expansion of cells that exhibit a progenitor-like nature.

Interleukin-driven insulin-like growth factor promotes prostatic inflammatory hyperplasia.

Prostatic inflammation is of considerable importance to urologic research because of its association with benign prostatic hyperplasia and prostate cancer. However, the mechanisms by which inflammation leads to proliferation and growth remain obscure. Here, we show that insulin-like growth factors (IGFs), previously known as critical developmental growth factors during prostate organogenesis, are induced by inflammation as part of the proliferative recovery to inflammation. Using genetic models and in vivo IGF receptor blockade, we demonstrate that the hyperplastic response to inflammation depends on interleukin-1-driven IGF signaling. We show that human prostatic hyperplasia is associated with IGF pathway activation specifically localized to foci of inflammation. This demonstrates that mechanisms of inflammation-induced epithelial proliferation and hyperplasia involve the induction of developmental growth factors, further establishing a link between inflammatory and developmental signals and providing a mechanistic basis for the management of proliferative diseases by IGF pathway modulation.

Prostate cancer ETS rearrangements switch a cell migration gene expression program from RAS/ERK to PI3K/AKT regulation.

BACKGROUND: The RAS/ERK and PI3K/AKT pathways induce oncogenic gene expression programs and are commonly activated together in cancer cells. Often, RAS/ERK signaling is activated by mutation of the RAS or RAF oncogenes, and PI3K/AKT is activated by loss of the tumor suppressor PTEN. In prostate cancer, PTEN deletions are common, but, unlike other carcinomas, RAS and RAF mutations are rare. We have previously shown that over-expression of "oncogenic" ETS transcription factors, which occurs in about one-half of prostate tumors due to chromosome rearrangement, can bypass the need for RAS/ERK signaling in the activation of a cell migration gene expression program. In this study we test the role of RAS/ERK and PI3K/AKT signaling in the function of oncogenic ETS proteins. RESULTS: We find that oncogenic ETS expression negatively correlates with RAS and RAF mutations in prostate tumors. Furthermore, the oncogenic ETS transcription factors only increased cell migration in the absence of RAS/ERK activation. In contrast to RAS/ERK, it has been reported that oncogenic ETS expression positively correlates with PI3K/AKT activation. We identified a mechanistic explanation for this finding by showing that oncogenic ETS proteins required AKT signaling to activate a cell migration gene expression program through ETS/AP-1 binding sequences. Levels of pAKT correlated with the ability of oncogenic ETS proteins to increase cell migration, but this process did not require mTORC1. CONCLUSIONS: Our findings indicate that oncogenic ETS rearrangements cause a cell migration gene expression program to switch from RAS/ERK control to PI3K/AKT control and provide a possible explanation for the high frequency of PTEN, but not RAS/RAF mutations in prostate cancer.

Acute bacterial inflammation of the mouse prostate.

BACKGROUND: Prostatic inflammation is gaining increasing attention as a potential etiologic factor in prostate cancer, benign prostatic hyperplasia, lower urinary tract symptoms, and CPPS. This study was performed to address the need for a well characterized model of acute prostatic inflammation that may be used to study the effect of acute inflammation on epithelial and stromal cell proliferation, voiding behavior, and neurovascular physiology. METHODS: Uropathogenic E. coli 1677 was instilled transurethrally into adult C57BL/6J male mice. Prostates were analyzed at 1, 2, 3, 5, 7, or 14 days post-instillation and compared to saline-instilled and naïve controls. Time course and severity of inflammation were characterized by the quantity and type of inflammatory infiltrate present, hemorrhage, proliferation, and reactive hyperplasia. RT-PCR was performed to characterize inflammatory mediators including IL-1α, IL-1ß, IL-1RA, IL-18, IL-6, IL-10, IL-8, TNFα, and COX-2. RESULTS: Inflammation was evident in all lobes of the prostate with the DLP most severely affected. Infection consistently led to a significant increase in neutrophils and macrophages in the early stages of prostate infection, followed by lymphocytic inflammation at the later time points. Inflammation was accompanied by induction of several inflammatory genes, including IL-1 family members, IL-6, and COX-2, and induced a significant increase in epithelial proliferation and reactive hyperplasia in all three prostate lobes. CONCLUSIONS: Transurethral inoculation of uropathogenic E. coli 1677 reliably infects the mouse prostate, produces a significant inflammatory response, and induces quantifiable epithelial proliferation and reactive hyperplasia.

Role of interleukins, IGF and stem cells in BPH.

The condition known as benign prostatic hyperplasia may be defined as a benign enlargement of the prostate gland resulting from a proliferation of both benign epithelial and stromal elements. It might also be defined clinically as a constellation of lower urinary tract symptoms (LUTSs) in aging men. The purpose of this review is to consider the ways in which inflammatory cytokines belonging to the interleukin family, members of the IFG family, and stem cells may contribute to the development and progression of BPH-LUTS. This might occur in three mechanisms: One, interleukin signaling, IFG signaling and stem cells may contribute to reactivation of developmental growth mechanisms in the adult prostate leading to tissue growth. Two, given that epidemiologic studies indicate an increased incidence of BPH-LUTS in association with obesity and diabetes, IFG signaling may provide the mechanistic basis for the effect of diabetes and obesity on prostate growth. Three, expression of interleukins in association with inflammation in the prostate may induce sensitization of afferent fibers innervating the prostate and result in increased sensitivity to pain and noxious sensations in the prostate and bladder and heightened sensitivity to bladder filling.

Regulation of phosphatase homologue of tensin protein expression by bone morphogenetic proteins in prostate epithelial cells.

BACKGROUND: Phosphatase homologue of tensin (PTEN) is the most commonly mutated gene in prostate cancer. Bone morphogenetic proteins (BMPs) are known to promote differentiation and inhibit proliferation. Previously published reports from other organ systems led us to investigate a mechanistic relationship between PTEN and BMP signaling in prostate epithelial cells. METHODS: We analyzed growth rate and PTEN expression in E6, BPH-1, and C4-2B prostate epithelial cells treated with BMP-4. We also treated doxacyclin-inducible PTEN-C4-2B cells with BMP-4 and doxacyclin to determine the effect of BMP on growth and PTEN expression in conditions of increasing PTEN expression. We determined the dependency of BMP-mediated growth inhibition via siRNA knockdown of PTEN expression and BMP treatment. We determined PTEN protein stability by determining the effect of BMP-4 on PTEN protein at time points after treatment with cyclohexamide, a translation inhibitor. RESULTS: We found that BMP-4 induces PTEN in E6 and BPH-1 cells and reduces proliferation. Knockdown of PTEN attenuated the growth-inhibiting effects of BMP-4 in these cells. BMP-4 had no effect in PTEN-negative C4-2B cells, but doxacyclin-driven PTEN C4-2B cells responded to BMP-4 with enhanced PTEN and growth inhibition. BMP-4 also increased PTEN protein stability. CONCLUSIONS: BMP signaling induces PTEN expression and sustains PTEN protein expression resulting in inhibition of prostate epithelial cell growth. These data are the first to identify a mechanistic linkage between BMP signaling and PTEN in the prostate, both of which are independently identified as tumor suppressors and suggest possible coordinate dysregulation in prostate cancer.

IL-1 induces IGF-dependent epithelial proliferation in prostate development and reactive hyperplasia.

Chronic inflammation and reactivation of developmental signaling pathways are both hallmarks of adenocarcinomas. However, developmental and inflammatory processes are generally thought of as distinct and are believed to represent separate paths to carcinogenesis. Here, we show that the inflammatory cytokine interleukin-1alpha (IL-1alpha) plays a critical role in prostate development by activating insulin-like growth factor (IGF) signaling; this process is reiterated during inflammatory reactive hyperplasia to elicit epithelial proliferation. The appearance of developmental signals during hyperplasia supports the hypothesis that reactivation of developmental signaling plays a role in the hyperplasic reaction to inflammation and suggests that there may be a conserved link between inflammatory signaling and canonical developmental pathways.

Celecoxib inhibits ureteral contractility and prostanoid release.

OBJECTIVES: To evaluate the efficacy and potency of clinically available celecoxib for inhibition of ureteral contractility and prostanoid release. We have previously reported that the selective cyclooxygenase (COX)-2 inhibitor NS-398 inhibits ureteral contractility. METHODS: We evaluated the release of prostaglandin (PG) E2, F2alpha, D2, thromboxane B2 (a thromboxane2 metabolite), and 6-keto-PGF1alpha (a prostacyclin metabolite) by gas chromatography-mass spectrometry from porcine ureters in the presence and absence of tumor necrosis factor-alpha (TNF-alpha), a putative cyclooxygenase (COX)-2 inducer. PGE2 and PGF2alpha were the prostanoids released in greatest quantity in response to TNF-alpha. We subsequently measured spontaneous contractility and prostanoid release in porcine ureters treated with 0.1, 1.0, or 10 microM concentrations of indomethacin (nonselective COX inhibitor), NS-398, celecoxib, or 0.1% dimethyl sulfoxide (vehicle) for 2 hours. Ureteral contractility and prostanoid release were measured every 15 minutes after the addition of the various compounds. We also treated ureters with 10 ng/mL TNF-alpha and all three COX inhibitors or dimethyl sulfoxide for 2 and 4 hours and measured the PGE2 and PGF2alpha release. RESULTS: Celecoxib, indomethacin, and NS-398 inhibited ureteral contractility and prostanoid release with similar efficacy and potency. All three compounds also reduced TNF-alpha-induced prostanoid release to control levels at concentrations as low as 0.1 microM. CONCLUSIONS: Our data have indicated that celecoxib and indomethacin inhibit PG release by the ureter to a similar degree, even in the presence of COX-2 induction. Animal experiments and clinical trials evaluating the safety and efficacy of celecoxib for the treatment of symptomatic ureteral obstruction are warranted.

Comparison of cryotherapy and nephrectomy in treating implanted VX-2 carcinoma in rabbit kidneys.

OBJECTIVE: To compare the efficacy of cryoablation and radical nephrectomy for treating implanted VX-2 carcinoma in rabbit kidneys. MATERIALS AND METHODS: A pilot study was conducted using 27 New Zealand white rabbits to assess the natural history of VX-2 carcinoma in the kidney. VX-2 tumour segments (1 mm(3)) were excised from subcutaneous tumours in carrier rabbits and implanted in the left kidney of study rabbits. The tumours were allowed to grow for 6, 7, 8, 9, 10, 14, 18, 21 and 28 days after implantation. Tumour progression was analysed in the kidney and surrounding serosa, and metastatic tumour presence in the lung, liver, spleen and bladder determined. After this, 80 rabbits were implanted with VX-2 in the lower pole and randomized into one of three groups: group 1, 35 rabbits treated 7 days after VX-2 implantation with cryoablation using a 15-min double-freeze technique and a 5-mm tumour margin target temperature of - 20 degrees C; group 2, 35 rabbits treated with open radical nephrectomy; or group 3, 10 untreated controls. Rabbits were maintained for 22 days and then killed; the kidneys, lungs, liver, spleen, urinary bladder and ureter were removed, and examined grossly and histologically for tumour presence. RESULTS: In the pilot study there was a consistent 50-100 mm(3) tumour after 7 days of growth, with no evidence of metastatic disease. By day 10 the mean kidney tumour was 230 mm(3) and two of three rabbits had metastases in the lung. By day 18 the mean primary tumour was 5504 mm(3) and all rabbits had metastatic disease. In the comparison study, cryotherapy cured 66% of implanted rabbits while nephrectomy cured 64%. All untreated controls had significant local and metastatic tumours. Findings in animals killed at 15 days after treatment showed significant differences between both treatment groups and untreated controls (P < 0.002). There was no difference in disease-free survival between the cryotherapy and open nephrectomy groups (P = 0.78) CONCLUSION: Both cryoablation and radical nephrectomy were effective in treating implanted VX-2 renal tumours compared with untreated controls. There was no statistically significant difference between cryoablation and nephrectomy.

Comparison of radiofrequency ablation, cryoablation, and nephrectomy in treating implanted VX-2 carcinoma in rabbit kidneys.

PURPOSE: To compare the efficacy of radiofrequency (RF) ablation, cryoablation, and radical nephrectomy in the treatment of implanted VX-2 carcinoma in rabbit kidneys. MATERIALS AND METHODS: Sixty-eight New Zealand White rabbits were implanted with 1-mm3 segments of VX-2 carcinoma in the left kidney. Seven days after implantation, the tumors were treated with one of the following: (1) RF ablation using a 12-gauge electrode (RITA Medical Systems, Mountain View, CA) at 90 degrees C for 8 minutes with a 5-mm tumor margin target temperature of 60 degrees C (N = 20); (2) cryoablation using a 15 minute double-freeze technique with 2.4-mm cryoprobes and the Cryocare system (Endocare Inc., Irvine, CA) with a 5-mm tumor margin target temperature of -20 degrees C (N = 20); (3) open radical nephrectomy (N = 20); or (4) no treatment (controls; N = 8). Rabbits were allowed to survive for a total of 22 days and sacrificed; and the kidneys, lungs, liver, spleen, urinary bladder, and ureter were removed and examined grossly and histologically for tumor. RESULTS: Findings in animals sacrificed at 15 days post-treatment showed significant differences between all treatment groups and untreated controls (P < 0.002) Using a 3 x 2 chi-square comparison, no differences in disease-free survival were observed between the RF ablation group, the cryoablation group, and the open nephrectomy group (P = 0.72) CONCLUSION: Radiofrequency ablation, cryoablation, and radical nephrectomy were all efficacious in the treatment of implanted VX-2 renal tumors compared with untreated controls (P = 0.002). No statistically significant difference was found between any of the three treatments.

Laparoscopic mid sagittal hemicystectomy and bladder reconstruction with small intestinal submucosa and reimplantation of ureter into small intestinal submucosa: 1-year followup.

PURPOSE: We evaluated the long-term results of laparoscopic hemicystectomy and bladder replacement with small intestinal submucosa (SIS) with ureteral reimplantation into the SIS material. MATERIALS AND METHODS: A total of 12 minipigs underwent laparoscopic hemicystectomy. Six pigs underwent bladder reconstruction with SIS and ipsilateral ureteral reimplantation. The remaining 6 control pigs underwent hemicystectomy and primary bladder closure with ipsilateral nephroureterectomy. Preoperative and followup evaluations included blood chemistry, radiography and urodynamic evaluations. The 6, 3, 6 and 9-week, and 12-month followup evaluations included biopsies. At 1 year the animals were sacrificed. Histopathological and contractility studies, and reverse transcriptase-polymerase chain reaction for growth factors and basement membrane components were performed. RESULTS: Bladder capacity and bladder compliance were similar in the 2 groups at all time points. One pig per group died, that is a control at the 9-month evaluation due to an anesthetic complication and an SIS pig 7 months after bladder reconstruction due to spontaneous bladder rupture at the anastomotic site. In the SIS group 4 of 5 surviving pigs had unobstructed reimplanted ureters without evidence of hydroureteronephrosis, while 1 had high grade obstruction at the reimplantation site. Histopathology study after 1 year revealed muscle at the graft periphery and center but it consisted of small fused bundles with significant fibrosis. Nerves were present at the graft periphery and center but they were decreased in number. CONCLUSIONS: Laparoscopic SIS bladder reconstruction and ureteral reimplantation into the SIS after hemicystectomy are technically feasible. However, compared to primary bladder closure no advantage in bladder capacity or compliance was documented.