Hamilto Yamamoto

CXCL12/CXCR4 Transactivates HER2 in Lipid Rafts of Prostate Cancer Cells and Promotes Growth of Metastatic Deposits in Bone

Chemokines and their receptors function in migration and homing of cells to target tissues. Recent evidence suggests that cancer cells use a chemokine receptor axis for metastasis formation at secondary sites. Previously, we showed that binding of the chemokine CXCL12 to its receptor CXCR4 mediated signaling events resulting in matrix metalloproteinase-9 expression in prostate cancer bone metastasis. A variety of methods, including lipid raft isolation, stable overexpression of CXCR4, cellular adhesion, invasion assays, and the severe combined immunodeficient–human bone tumor growth model were used. We found that (a) CXCR4 and HER2 coexist in lipid rafts of prostate cancer cells; (b) the CXCL12/CXCR4 axis results in transactivation of the HER2 receptor in lipid rafts of prostate cancer cells; (c) Src kinase mediates CXCL12/CXCR4 transactivation of HER2 in prostate cancer cells; (d) a pan-HER inhibitor desensitizes CXCR4-induced transactivation and subsequent matrix metalloproteinase-9 secretion and invasion; (e) lipid raft–disrupting agents inhibited raft-associated CXCL12/CXCR4 transactivation of the HER2 and cellular invasion; (f) overexpression of CXCR4 in prostate cancer cells leads to increased HER2 phosphorylation and migratory properties of prostate cancer cells; and (g) CXCR4 overexpression enhances bone tumor growth and osteolysis. These data suggest that lipid rafts on the cell membrane are the key site for CXCL12/CXCR4–induced HER2 receptor transactivation. This transactivation contributes to enhanced invasive signals and metastatic growth in the bone microenvironment. (Mol Cancer Res 2008;6(3):446–57)

Inhibition of human prostate cancer growth, osteolysis and angiogenesis in a bone metastasis model by a novel mechanism-based selective gelatinase inhibitor

Metastasis to the bone is a major clinical complication in patients with prostate cancer (PC). However, therapeutic options for treatment of PC bone metastasis are limited. Gelatinases are members of the matrix metalloproteinase (MMP) family and have been shown to play a key role in PC metastasis. Herein, we investigated the effect of SB‐3CT, a covalent mechanism‐based MMP inhibitor with high selectivity for gelatinases, in an experimental model of PC bone metastases. Intraperitoneal (i.p.) treatment with SB‐3CT (50 mg/kg) inhibited intraosseous growth of human PC3 cells within the marrow of human fetal femur fragments previously implanted in SCID mice, as demonstrated by histomorphometry and Ki‐67 immunohistochemistry. The anti‐osteolytic effect of SB‐3CT was confirmed by radiographic images. Treatment with SB‐3CT also reduced intratumoral vascular density and bone degradation in the PC3 bone tumors. A direct inhibition of bone marrow endothelial cell invasion and tubule formation in Matrigel by SB‐3CT in vitro was also demonstrated. The use of the highly selective gelatinase inhibitors holds the promise of effective intervention of metastases of PC to the bone.

Bone marrow stromal cells enhance prostate cancer cell invasion through type I collagen in an MMP‐12 dependent manner

At the cellular level, the process of bone metastasis involves many steps. Circulating cancer cells enter the marrow, proliferate, induce neovascularization, and ultimately expand into a clinically detectable, often symptomatic, metastatic deposit. Although the initial establishment and later expansion of the metastatic deposit in bone require tumor cells to possess invasive capability, the exact proteases responsible for this phenotype are not well known. The objective of our study was to take an unbiased approach to determine which proteases were expressed and functional during the initial interactions between prostate cancer cells and bone marrow stromal (BMS) cells. We found that the combination of human prostate cancer PC3 and BMS cells stimulates the invasive ability of cancer cells through type I collagen. The use of inhibitors for each of the major protease families indicated that 1 or more MMPs was/were responsible for the BMS‐induced invasion. Gene profiling and semiquantitative RT‐PCR analysis revealed an increased expression of several MMP genes because of PC3/BMS cell interaction. However, only MMP‐12 showed an increase in protein expression. Downregulation of MMP‐12 expression in PC3 cells by siRNA inhibited the enhanced invasion induced by PC3/BMS cell interaction. In vivo, MMP‐12 was found to be primarily expressed by prostate cancer cells growing in bone. Our data suggest that BMS cells induce MMP‐12 expression in prostate cancer cells, which results in invasive cells capable of degradation of type I collagen.

Host matrix metalloproteinase-9 contributes to tumor vascularization without affecting tumor growth in a model of prostate cancer bone metastasis

Matrix metalloproteinases (MMPs) have been associated with initiation, progression and vascularization of a number of tumors. However, clinical trials using MMP inhibitors failed to meet expectations. Previously, we demonstrated the potential importance of MMP-9 activity in experimental prostate cancer bone tumor tissue. However, the particular roles of host- and tumor-derived MMP-9 remains to be defined. Herein, we examined the role of host MMP-9 in subcutaneous and intraosseous growth of the human androgen independent prostate cancer cell line PC3 in MMP-9 deficient mice. In the subcutaneous model, the tumor incidence in the control (RAG-1ko/ko) and experimental (RAG-1ko/ko /MMP-9ko/ko) group was 100%, with similar tumor growth kinetics and microvascular densities. In the intraosseous tumor model, the tumor incidence was higher in RAG-1ko/ko /MMP-9ko/ko mice than in RAG-1ko/ko mice (67% and 39%, respectively), though no statistical differences were found. The intraosseous tumor areas were similar in both groups, and the number of tumor-associated osteoclasts did not differ significantly. However, the microvascular density of intraosseous tumors was higher in RAG-1ko/ko than in RAG-1ko/ko/MMP-9ko/ko mice, though no changes in tumor growth could be detected. In an in vitro assay, we found that bone marrow (BM) cells increased the invasiveness of PC3 cells, and that this enhancement was independent of MMP-9 expression by marrow cells. Our results with the RAG-1 model suggest that host-derived MMP-9 is neither necessary nor sufficient for subcutaneous or intraosseous PC3 tumor growth, osteoclastic response, or in vitro invasiveness of tumor cells.

Laparoscopic management of iatrogenic lesions

PURPOSE To present our series of patients who underwent laparoscopic correction of iatrogenic lesions and a review of the literature. PATIENTS AND METHODS We evaluated 23 patients who underwent laparoscopic correction of iatrogenic lesions. Thirteen patients had open surgery, 6 had an endoscopic procedure, and 4 had a laparoscopic approach as the first surgical procedure. Vesicovaginal fistulas (VVF) developed in seven patients after open abdominal hysterectomies, and 1 patient presented with a VVF after ureterolithotripsy. A urethral cutaneous fistula developed in one patient after a laparoscopic resection of endometriosis nodules, and 1 patient presented with a ureterovaginal fistula after a perineoplasty. Three patients presented with encrusted ureteral stents after ureterolithotripsy. Ureteral stenosis developed in seven patients: three after open abdominal surgery, three after ureteroscopy, and one after pyeloplasty. One patient had a ureteral injury during laparoscopic partial nephrectomy, and two patients had bowel injuries after a tension-free vaginal tape procedure and a laparoscopic radical prostatectomy. RESULTS All patients underwent laparoscopic correction of the iatrogenic injuries. One patient had an early recurrence of a VVF, and one patient had a recurrence of a ureteral stenosis. There was one conversion to open surgery because of technical difficulties and one major bleeding event that necessitated blood transfusion. A lower limb compartmental syndrome developed in one patient. CONCLUSION Despite the small number of patients and different types of surgeries performed, laparoscopic management of iatrogenic lesions seems to be feasible and safe in experienced hands. Its precise role in the management of this stressful condition still needs to be determined.

Cold Renal Ischemia: Comparison of Efficacy Between Two Techniques of Cooling, in a Swine Model

OBJECTIVES In a swine model of renal ischemia, we compared the effectiveness of the transurethral retrograde cold saline perfusion technique to the traditional method of renal cooling with ice slush, in achieving adequate parenchymal temperatures for functional preservation of the organ. Physiological and histological effects were also assessed. METHODS Twenty-four domestic male pigs were sampled into four groups to be submitted to a 60-minute ischemia of the left kidney without cooling, with either one of the two cooling techniques (cold saline retrograde perfusion or ice slush), or sham surgery. All of them had also a concomitant right nephrectomy. Renal cortical and medullary temperatures were recorded throughout the experiment. Urinary output was measured, and serum renal function tests were carried on, pre- and postoperatively. After 5 days, the animals were euthanized and their kidneys were submitted to histological analysis. RESULTS Mean renal temperature fell in both groups submitted to kidney cooling. With ice slush, a faster drop was observed and a lower minimum temperature was achieved (5.0 degrees C in the cortex and 6.3 degrees C in the medulla, vs. 25.4 degrees C and 24.9 degrees C with retrograde cooling). In the other groups, temperature was unchanged. Urinary output and serum creatinine worsened after the experiment, but without significant differences among groups. The histological analysis showed no differences among the four groups, for the studied ischemia time. CONCLUSIONS Ice slush and retrograde perfusion of cold saline are both effective for cooling the kidney during ischemia. Ice slush is faster in doing so, and it allows much lower temperatures to be achieved in the renal parenchyma. With ischemia time of 60 minutes, no significant differences on the occurrence of functional and histological alterations were detected, even for the group without a cooling procedure.

Transplanting a horseshoe kidney: A case report and review of surgical strategies

Currently, most countries face a shortage of kidney, while a progressive increase in transplant waiting lists occurs. Measures such as the use of expanded criteria donors or continuous machine perfusion for organs aim to reduce the wastage of potentially usable kidneys. In such a scenario, transplanting a donated horseshoe kidney (HSK), although infrequent and technically challenging, could save more patients. The use of HSKs in transplantation has been hindered mostly by the complex anatomical features. HSKs commonly have multiple vessels, along with duplicated or anomalous collecting system, atop an isthmus (that may or not be vascularized) connecting both lower poles. A HSK may be implanted en bloc or split in two, which could be transplanted into two recipients. Either way, some kind of vascular or urinary reconstruction is likely. Few publications report the transplant of HSKs. In this paper we describe a transplant of a HSK and review technical strategies.

Pelvic floor muscle training and electrical stimulation as rehabilitation after radical prostatectomy: a randomized controlled trial

[Purpose] To investigate the effect of electrical stimulation and pelvic floor muscle training on muscle strength, urinary incontinence and erectile function in men with prostate cancer treated by radical prostatectomy. [Subjects and Methods] One hundred twenty-three males were randomized into 3 groups 1 month after RP: (G1, n=40) control; (G2, n=41) guideline: patients were instructed to perform three types of home exercises to strengthen the pelvic floor and (G3, n=42) electrical stimulation: patients in this group were also instructed to perform exercises as group G2, and also received anal electro-stimulation therapy, twice a week for 7 weeks. The primary outcome assessment was based on the measurement of the recovery of pelvic floor muscle strength between groups. Secondary outcomes were: 1 hour Pad Test, ICIQ-SF, IIEF-5 and IPSS. Data were obtained preoperatively and at 1, 3 and 6 months after surgery. [Results] There was no significant difference in the demographic data among groups. Greater urinary leakage and pelvic floor muscle weakness in the first month compared to pre treatment improved after 3 and 6 months postoperative, without difference among groups. [Conclusion] The muscle strength recovery occurs independently of the therapy employed. Pelvic floor exercises or electrical stimulation also did not have an impact on the recovery of urinary continence and erectile function in our study.

Impact of vulvovaginal atrophy on pelvic floor muscle strength in healthy continent women

To assess the correlation between hormonal status and pelvic floor muscle strength.

433 HETEROGENEOUS ACTIVATION OF MMP-9 DUE TO PROSTATE CANCER-BONE INTERACTION

OBJECTIVES To determine whether matrix metalloproteinase (MMP)-9 activation resulting from prostate cancer cell-bone interaction is dependent on the tumor cell type and/or the nature of the bone microenvironment. METHODS In vitro co-cultures of human prostate cancer cells (PC3 and C4-2B) and mouse, human fetal, or human adult tissues were performed. In vivo the tumor cells were intratibially injected in SCID mice or intraosseously inoculated into fetal or adult bone xenografts in SCID mice. MMP-2 and MMP-9 expression and activation were determined by gelatin zymography in conditioned media obtained in vitro and in lysates derived from the in vivo studies at different time points. RESULTS Activation of MMP-9 occurred when PC3 cells interacted with human adult or fetal bone, either in vitro or in vivo at early time points. With C4-2B cells, activation of MMP-9 only happened in the human adult bone microenvironment at early time points after intraosseous inoculation of tumor cells. No activation of MMP-9 occurred when PC3 or C4-2B cells interacted with mouse bone, either in vitro or in vivo. CONCLUSIONS The results of our study have shown that the activation of MMP-9 when human prostate cancer cells interact with bone depends on the particular identity of the tumor cells and the type of bone tissue used. These findings have broad implications for experimental models attempting to define tumor-microenvironmental interactions in bone metastasis.