Mutsushi Yamasaki

Lower Incidence of Inguinal Hernia: Minilaparotomy Radical Retropubic Prostatectomy Compared with Conventional Technique

Introduction: The purpose of the present study was to compare the incidence of inguinal hernias after conventional and minilaparotomy (minilap) radical retropubic prostatectomy (RRP). Patients and Methods: In this retrospective study, we review our experience with 70 consecutive patients with prostate cancer who underwent prostatectomy from April 1995 through March 2001. Of these, 35 patients had conventional RRP, and 35 patients had minilap RRP. Results: Conventional RRP and minilap RRP groups were similar in body mass index (mean 24.4 and 23.5), operative time (mean 260 and 241 min), previous lower abdominal operation record (mean 37.1 and 25.7%), and post-prostatectomy anastomotic strictures (mean 11.4 and 14.3%). The volume of the estimated blood loss was significantly less for minilap RRP (mean 1,220 ml) than for conventional RRP (mean 1,666 ml; p = 0.0194). The incidence of postoperative inguinal hernias was 17.1% (6 of 35), 2.9% (1 of 35), and 3.2% (1 of 31) in conventional RRP, minilap RRP, and unoperated groups, respectively. The incidence of inguinal hernias after minilap RRP was significantly lower than after conventional RRP (p = 0.0464). Seven patients with postoperative inguinal hernias had a high incidence of postoperative strictures (42.9%), while 63 patients without hernia had a low incidence (9.5%). There was a significant difference in developing postoperative strictures between patients with hernia and those without (p = 0.0124). While postoperative stricture and operative technique were different in the hernia and hernia-free groups on univariate analysis, multivariate logistic analysis revealed that the operative technique was an independent factor for the occurrence of inguinal hernias (p = 0.0419). Conclusion: Minilap RRP compares favorably with conventional RRP in view of the postoperative inguinal hernia development.

Dual targeting of heat shock proteins 90 and 70 promotes cell death and enhances the anticancer effect of chemotherapeutic agents in bladder cancer

Heat shock proteins (HSPs), which are molecular chaperones that stabilize numerous vital proteins, may be attractive targets for cancer therapy. The aim of the present study was to investigate the possible anticancer effect of single or dual targeting of HSP90 and HSP70 and the combination treatment with HSP inhibitors and chemotherapeutic agents in bladder cancer cells. The expression of HSP90 and the anticancer effect of the HSP90 inhibitor 17-N-allylamino-17-demethoxygeldanamycin (17-AAG) coupled with cisplatin, docetaxel, or gemcitabine were examined using immunohistochemistry, quantitative real-time PCR, cell growth, flow cytometry, immunoblots and caspase-3/7 assays. The expression of HSP70 under HSP90 inhibition and the additive effect of HSP70 inhibitor pifithrin-μ (PFT-μ) were examined by the same assays and transmission electron microscopy. HSP90 was highly expressed in bladder cancer tissues and cell lines. 17-AAG enhanced the antiproliferative and apoptotic effects of each chemotherapeutic agent. 17-AAG also suppressed Akt activity but induced the upregulation of HSP70. PFT-μ enhanced the effect of 17-AAG or chemotherapeutic agents; the triple combination of 17-AAG, PFT-μ and a chemotherapeutic agent showed the most significant anticancer effect on the T24 cell line. The combination of 17-AAG and PFT-μ markedly suppressed Akt and Bad activities. With HSP90 suppression, HSP70 overexpression possibly contributes to the avoidance of cell death and HSP70 may be a key molecule for overcoming resistance to the HSP90 inhibitor. The dual targeting of these two chaperones and the combination with conventional anticancer drugs could be a promising therapeutic option for patients with advanced bladder cancer.

Targeting the Vav3 oncogene enhances docetaxel- induced apoptosis through the inhibition of androgen receptor phosphorylation in LNCaP prostate cancer cells under chronic hypoxia

BackgroundThe Vav family of Rho/Rac guanosine nucleotide exchange factors comprises three members in mammalian cells. Vav3 enhances androgen receptor (AR) activity during progression to androgen independence in prostate cancer. We examined Vav3 small interfering RNA (siRNA) effects on cell proliferation and apoptosis in docetaxel-treated LNCaP cells under chronic hypoxia (LNCaPH).MethodsWe examined individual and combined effects of Vav3 siRNA (si-Vav3) and docetaxel on cell growth and apoptosis under chronic hypoxia by cell proliferation, flow cytometric, DNA fragmentation, and immunoblot analyses. To clarify the molecular basis of si-Vav3- and docetaxel-induced apoptosis, we analyzed alterations in phosphatidylinositol 3-kinase (PI3K)/Akt, extracellular signal-regulate kinase (ERK), c-jun N-terminal kinase (JNK), and AR pathways using kinase inhibitors in LNCaPH cells. The effects of si-Vav3/atelocollagen complex alone or in combination with docetaxel were assessed on xenografts in nude mice by tumor growth delay.ResultsVav3 overexpression was observed in LNCaPH compared with the expression under normoxia. Interrupting Vav3 signaling using siRNA enhanced docetaxel-induced cell growth suppression compared with that induced by docetaxel alone by inhibition of Akt and ERK phosphorylation, resulting in AR phosphorylation inhibition. In addition to increased B-cell lymphoma 2 (Bcl-2) phosphorylation through JNK signaling in response to docetaxel, si-Vav3 enhanced docetaxel-induced apoptosis, as characterized by the accumulation of sub-G1 phase cells and DNA fragmentation, through Bcl-xL/Bcl-2-associated death promoter (Bad) dephosphorylation, resulting in increased caspase-9, caspase-3, and cleaved poly(ADP-ribose) polymerase activation. Xenograft tumor growth was slightly inhibited by si-Vav3/atelocollagen complex injection and combined use of si-Vav3/atelocollagen complex and docetaxel produced a greater effect than docetaxel alone.ConclusionsInterrupting Vav3 signaling enhances docetaxel-induced apoptosis in LNCaP cells under chronic hypoxia by inhibiting the PI3K/Akt, ERK, and AR signaling pathways. Therapy targeting Vav3 in combination with docetaxel may have practical implications for managing castration-resistant prostate cancer.

Angiopoietin-like protein 2 induces androgen-independent and malignant behavior in human prostate cancer cells

Angiopoietin-like proteins (ANGPTLs), which comprise 7 members (ANGPTL1-ANGPTL7), structurally resemble angiopoietins. We investigated the roles of ANGPTLs in the acquisition of androgen independence and the malignant behavior of human prostate cancer cells. Expression of ANGPTL messenger RNA (mRNA) and proteins were ascertained using RT-qPCR and western blot analysis in human prostate cancer cell lines. Androgen-dependent LNCaP and androgen-independent LNCaP/AI cells, respectively, were cultured in fetal bovine and charcoal-stripped medium. Cell proliferation, androgen dependence, migration and invasion, respectively, were examined under the overexpression and knockdown of ANGPTL2 by transfection of ANGPTL2 cDNA and its small-interfering RNA (siRNA). The effects of exogenous ANGPTL2 and blocking of its receptor, integrin α5β1, were also investigated. Human prostate cancer cell lines predominantly expressed ANGPTL2 among the members. Interrupting ANGPTL2 expression with siRNA suppressed the proliferation, migration and invasion of LNCaP cells. LNCaP/AI cells showed a higher ANGPTL2 expression than that of LNCaP cells. Furthermore, siRNA led to apoptosis of LNCaP/AI cells. The ANGPTL2-overexpressing LNCaP cells markedly increased proliferation, epithelial-to-mesenchymal transition (EMT) and malignant behavior in androgen-deprived medium. The migration rates were increased depending on the concentration of ANGPTL2 recombinant protein and were inhibited by anti-integrin α5β1 antibodies. To the best of our knowledge, this is the first study to elucidate the expression of ANGPTL2 in human prostate cancer cells. ANGPTL2 may be important in the acquisition of androgen independency and tumor progression of prostate cancer in an autocrine and/or paracrine manner via the integrin α5β1 receptor. Targeting ANGPTL2 may therefore be an efficacious therapeutic modality for prostate cancer.

Chronic hypoxia induces androgen-independent and invasive behavior in LNCaP human prostate cancer cells

PURPOSE Tumor hypoxia is a common feature of any cancer, including prostate cancer (CaP), and associated with tumor cell aggressiveness. Although some reports are available on acute hypoxia-response in CaP cells aggressiveness, little is known about chronic hypoxia-response. We investigated the effects of chronic hypoxia on human CaP cells. MATERIALS AND METHODS The human androgen-dependent CaP cell line LNCaP was cultured under normoxia (21% O2), acute hypoxia (1% O2), or chronic hypoxia (1% O2 for over 6 months). The cell growth, cell cycle and cell behavior of these cells were analyzed by cell count, flow cytometric analysis and in vitro cell migration and invasion assay, respectively. The expression of matrix metalloproteinases and intracellular signaling pathways were tested by real time reverse transcriptase-polymerase chain reaction and Western blotting. RESULTS Chronic hypoxia-conditioned LNCaP cells grew in an androgen-independent manner with acceleration of G1 to S phase cell cycle progression. Chronic hypoxia, but not acute hypoxia, accelerated cell migration and invasion. The expressions of matrix metalloproteinase-7, -9, -14, and -15 were significantly up-regulated in LNCaP cells under chronic hypoxia, but not under acute hypoxia. In addition, PI3K/Akt, JAK/STAT, and HIF-1 pathways were activated in chronic hypoxia-conditioned LNCaP cells. CONCLUSIONS These results suggested that chronic hypoxia plays an important role in enhancement of malignant potential during androgen-independent CaP progression.

The Vav3 oncogene enhances the malignant potential of prostate cancer cells under chronic hypoxia

OBJECTIVES We had previously reported that chronic hypoxia induces androgen-independent growth in the human prostate cancer cell line LNCaP. In this study, we have identified a key molecule, the Vav3 oncogene, and investigated the effects of Vav3 overexpression on cancer cell growth and malignant behavior and the possible apoptosis-inducing effect of Vav3 expression knockdown by small interfering ribonucleic acid (siRNA) in LNCaP cells under chronic hypoxia (LNCaP/CH). METHODS AND MATERIALS Hypoxia-inducible oncogenes were identified by complementary deoxyribonucleic acid (cDNA) microarray and Ingenuity Pathway Analysis in order to investigate gene ontology and functional pathways and networks. siRNA was used to knockdown the Vav3 target gene and analyze the effects on proliferation, invasion, migration, and apoptosis of LNCaP/CH cells. Vav3 cDNA was transfected into LNCaP cells under normoxia (LNCaP/N) to establish Vav3-overexpressing clonal cell lines, whose proliferation, invasion, and migration was then examined. Immunoblot analysis was used to investigate the activation of Akt, a Vav3 downstream target molecule. RESULTS cDNA microarray analysis and Ingenuity Pathway Analysis identified Vav3 as a hypoxia-inducible oncogene that was highly associated with malignant behavior. Vav3 messenger RNA and protein expression in LNCaP/CH cells were higher than in LNCaP/N and LNCaP cells cultured under acute hypoxia (LNCaP/AH). The growth rate of LNCaP/CH cells was lower than that of LNCaP/N cells but higher than that of LNCaP/AH cells. LNCaP/CH cells showed higher invasion and migration than LNCaP/N and LNCaP/AH cells. Interrupting Vav3 expression strongly suppressed the proliferation, invasion, and migration of LNCaP/CH cells. Furthermore, siRNA led to apoptosis with increased caspase-3 and cleaved poly (adenosine diphosphate-ribose) polymerase activation in LNCaP/CH cells. Stable Vav3 overexpression in LNCaP cells promoted cell proliferation, invasion, and migration with Akt activation. CONCLUSIONS Our results demonstrate that Vav3 plays a crucial role in prostate cancer growth and malignant behavior, thus revealing a novel potential therapeutic target.

A Case of Large Solitary Fibrous Tumor in the Retroperitoneum

Solitary fibrous tumor (SFT) is a rare spindle cell neoplasm mainly originated in the pleural cavity. We report here an unusual case of a large SFT in the retroperitoneum. A 27-year-old female complaining of a palpable mass in the right flank with dull pain was admitted to our hospital with the diagnosis of right retroperitoneal tumor. Computed tomography (CT) and magnetic resonance imaging (MRI) showed a large retroperitoneal tumor arising from latissimus dorsi muscle. Surgical findings revealed a partly encapsulated tumor and complete resection of tumor concomitantly with right kidney, 11th and 12th ribs, and diaphragm was performed. Pathological examination demonstrated the tumor to be composed of increased mitotic activity and cellularity of spindle cells with a collagenous matrix. Immunohistochemical staining was positive for CD34, vimentin, and basic fibroblast growth factor (bFGF) and negative for CD31, cytokeratin, desmin, S-100p, smooth muscle actin, Bc1-2, and insulin-like growth factor (IGF) with Ki-67 labeling index of 0.1%. Based on pathological features, diagnosis of SFT in the retroperitoneum was confirmed. To our knowledge, this is the first report of an SFT arising from latissimus dorsi muscle and it is important to include SFT in the differential diagnosis of retroperitoneal tumors that caused considerable diagnostic problems due to its unusual site of origin.

Intestinal perforation after cadaveric renal transplantation

Abstract We performed cadaveric renal transplantation on a 46‐year‐old man on long‐term hemodialysis. Methicillin‐resistant Staphylococcus aureus (MRSA) enterocolitis occurred on the fifth postoperative day and severe intestinal ulceration and perforation followed. Subtotal abdominal colectomy and the simultaneous removal of the transplant were performed. Postoperatively, disseminated intravascular coagulopathy with pancytopenia and cerebral hemorrhagic infarction developed and the patient died 40 days later.

Repair of ileal conduit parastomal hernia by translocation of the stoma

Abstract  We repaired a recurrent ileal conduit parastomal hernia, according to Kaufmans technique, by translocating the stoma to the opposite side of the abdominal wall without laparotomy. This procedure is a simple and less invasive treatment for large parastomal hernia.

Recto-peritoneal fistula following transperineal prostate biopsy

Abstract  A recto‐peritoneal fistula is an extremely rare complication after prostate biopsy. We report herein on a peritonitis arising from a recto‐peritoneal fistula 5 days after undergoing prostate biopsy. To our knowledge, this is the first case of recto‐peritoneal fistula following transperineal needle biopsy of the prostate in the published literature.