De novo renal cell carcinoma of native and graft kidneys in renal transplant recipients.

OBJECTIVE: • To access the epidemiological, clinical and survival features of renal transplant patients with de novo renal cell carcinoma of native and graft kidneys. PATIENTS AND METHODS: • We performed a retrospective examination of the data of 2001 consecutive renal transplant recipients at our centre between November 1979 and January 2010. RESULTS: • In the patient cohort examined, 30 renal cell carcinomas were observed in 26 individuals (incidence 1.5%) with 25 tumours in the native and five in allograft kidneys. Mean tumour size in surgical specimens was 44 ± 36 mm. The rate of papillary cancer was 37.5%. • After a mean follow-up of 58.6 ± 62.3 months, 15.4% of the patients died from cancer and 57.7% were in complete remission. • Overall and tumour-specific survival rates at 1, 5 and 10 years were 86.1%, 75.1% and 43.8%, and 90.4%, 83.5% and 66.8%, respectively. CONCLUSIONS: • Due to increasingly improved survival after renal transplantation, de novo malignancies might soon become the main cause of intermediate- or long-term mortality. • Current data support an increased risk of renal cell carcinoma in renal transplant recipients in a particularly aggressive way, but low tendency for metachronous contralateral evolution. • With continuous radiological follow-ups, acceptable oncological outcome can be achieved. Graft tumours may have a favourable prognosis.

Development of urological cancers in renal transplant recipients: 30-year experience at the Frankfurt Transplant Center.

Fatal post-transplant malignancies with a high proportion of genitourinary neoplasms represent a serious long-term challenge. With continuous improvement of the allograft and patient survival, cancer development after renal transplantation may soon turn to the leading morbidity cause. In a retrospective single-center study of 1990 renal transplant recipients between November 1979 and November 2009, records of patients with urological neoplasms including epidemiological, clinical and survival parameters were accessed. Sixty-six de novo urological malignancies in 58 recipients were recorded in the study period, being most common after skin cancers (15.6% of enregistered tumors). From these, 29 were renal cell cancers, including five neoplasms of transplanted kidney, 24 transitional cell carcinomas, 11 prostate carcinomas, and two germ cell carcinomas with incidence rates of 1.5%, 1.2%, 0.9% and 0.2%, respectively. The patient follow up was virtually complete. Tumor-related death was found in 44% of cases. By multivariate analysis, no influence of either duration of dialysis, mode or duration of immunosuppression, gender or age at transplantation on overall patient survival could be demonstrated. This study, documenting a 30-year single center experience, emphasizes the increased risk for urological neoplasms occuring after renal transplantation. Screening strategies for urological cancers should be optimized.

Plasmin-clipped beta(2)-glycoprotein-I inhibits endothelial cell growth by down-regulating cyclin A, B and D1 and up-regulating p21 and p27.

beta(2)-Glycoprotein-I (beta(2)gpI), an abundant plasma glycoprotein, functions as a regulator of thrombosis. Previously, we demonstrated that plasmin-clipped beta(2)gpI (cbeta(2)gpI) exerts an anti-angiogenic effect on human umbilical vein endothelial cells (HUVEC). The present study was focused on the molecular background responsible for this phenomenon. cbeta(2)gpI strongly reduced HUVEC growth and proliferation as evidenced by the MTT and BrdU assay and delayed cell cycle progression arresting HUVEC in the S-and G2/M-phase. Western blot analysis indicated that cbeta(2)gpI inhibited cyclin A, B and D1, and enhanced p21 and p27 expression. Activity of p38 was down-regulated independently from the cbeta(2)gpI incubation time. Phosphorylation of ERK1/2 was not changed early (30 and 60 min) but became enhanced later (90 min, 4h). JNK activity was reduced rapidly after cbeta(2)gpI treatment but compared to controls, increased thereafter. Annexin II blockade prevented growth inhibition and cell cycle delay evoked by cbeta(2)gpI. We assume that cbeta(2)gpI's effects on HUVEC growth is mediated via cyclin A, B and D1 suppression, up-regulation of p21 and p27 and coupled to modifications of the mitogen-activated protein (MAP) kinase signalling pathway. cbeta(2)gpI may represent a potential endogenous angiogenesis-targeted compound, opening the possibility of a novel tool to treat cancer.

Association of intravesical tumor location with metastases to the pelvic lymph nodes in transitional cell cancer of the bladder.

INTRODUCTION: In this study, we aimed to determine those clinical and pathologic features that are associated with pelvic lymph node metastasis in patients with transitional cell cancer of the bladder. Unlike previous studies, we particularly focused on intravesical tumor location. METHODS: We included 173 patients who underwent radical cystectomy and bilateral pelvic lymphadenectomy for muscle-invasive or high-risk superficial bladder cancer. Fifty patients (28.9%) presented with lymph node metastases. Tumor-related and personal characteristics were analyzed. RESULTS: Lymph node positive disease occurred in association with an increasing pathologic tumor stage (P < 10(-6)) and with a decreasing differentiation status (P = 0.008). The rate of pelvic lymph node metastasis differed in primary tumors growing on different intravesical locations. Cancers located exclusively on the lateral bladder walls (P < 10(-5)) and tumors involving the lateral walls (P = 0.042) were highly correlated with lymph node positive disease. Posterior wall tumors were least associated with lymph node metastases compared with other tumor locations (P = 0.015). Focal tumor growths located on the lateral bladder wall and an increasing pathologic tumor stage and decreasing differentiation-status were identified as independent risk factors for the pelvic lymph node status. CONCLUSIONS: For the first time we present the association of intravesical tumor location and the rate of lymph node metastasis in transitional cell cancer of the bladder. Our findings may ultimately contribute to a more individualized patient management.

Maspin modulates adhesion of bladder carcinoma cells to vascular endothelium.

PURPOSE: Maspin belongs to the serpin family and has been shown to suppress tumor growth and metastasis in several tumor types. The role of maspin in bladder carcinoma has not been fully elucidated, and the object of this study was to investigate whether maspin contributes to bladder tumor adhesion to vascular endothelial cells (HUVEC). METHODS: Expression of maspin-coding mRNA was evaluated in a panel of bladder carcinoma cell lines. Maspin distribution in maspin mRNA(high) versus maspin mRNA(low) cells was further analyzed by flow cytometry and confocal microscopy. Adhesion to HUVEC was measured in a coculture model and correlated with the surface-bound maspin. RESULTS: Maspin(high) (RT-4, RT-112) cell lines strongly attached to HUVEC, whereas maspin(low) (UMUC-3, MGH-U1) cell lines poorly adhered to HUVEC. Distinct cytoplasmic maspin accumulation and moderate surface-bound maspin was found in RT-4 cells. Blocking maspin surface receptors prevented tumor cell attachment to HUVEC, indicating that surface-bound maspin is responsible for triggering cell adhesion. PMA-triggered elevation of surface-bound maspin was accompanied by an enhanced adhesion capacity of RT-4 cells, compared to controls. Finally, exposing the bladder carcinoma cells to the differentiation-inducing agent valproic acid led to a surface-bound (but not cytoplasmic) maspin decrease, paralleled by a significant reduction in tumor cell binding to HUVEC. CONCLUSION: Surface-bound maspin directly controls bladder carcinoma cell adhesion to the vascular wall. Blocking this process may prevent transendothelial migration and tumor cell dissemination. Therefore, therapeutic down-regulation of surface-bound maspin might become an option to prevent tumor spread into distant organs.

Effects of combined valproic acid and the epidermal growth factor/vascular endothelial growth factor receptor tyrosine kinase inhibitor AEE788 on renal cell carcinoma cell lines in vitro.

OBJECTIVE: To evaluate adhesion and growth inhibiting effects of the multiple receptor tyrosine kinase inhibitor AEE788 and the histone deacetylase (HDAC) inhibitor valproic acid (VPA) on renal cell carcinoma (RCC) cells. MATERIALS AND METHODS: Caki-1 cells were treated with AEE788 and VPA, either alone or in combination, to investigate RCC cell adhesion to vascular endothelial cells or to immobilized extracellular matrix proteins. Tumour cell proliferation was examined by MTT dye reduction assay. Effects of drug treatment on cell signalling pathways were determined by Western blotting. The expression levels of integrin alpha and beta subtypes were evaluated by flow cytometry (surface expression) and Western blotting (intracellular protein expression). RESULTS: RCC cell treatment with AEE788 and VPA in combination resulted in a stronger inhibition of tumour cell proliferation than that caused by either drug alone. There were also additive effects of the combined treatment on tumour cell adhesion to endothelial cells and to immobilized laminin (but not to immobilized fibronectin and collagen). AEE788 alone or combined with VPA reduced Akt expression and histone H3 acetylation. Both compounds altered integrin alpha and beta subtype expression, in particular alpha1, alpha3 and beta4, and blocked integrin-dependent integrin-linked kinase and focal-adhesion kinase (total and phosphorylated) signalling. CONCLUSIONS: Both AEE788 and VPA profoundly block the interaction of RCC cells with endothelium and extracellular matrix and reduce tumour growth in vitro. Therefore, this combined regimen warrants further preclinical and possible clinical study for treating advanced RCC.

Tumor-endothelium cross talk blocks recruitment of neutrophils to endothelial cells: a novel mechanism of endothelial cell anergy.

Tumor cells have evolved effective strategies to escape the host immune response. The objective of this study was to determine whether tumor cells can condition endothelial cells in a specific manner to prevent subsequent adhesion of polymorphonuclear neutrophils (PMNs) and/or peripheral blood lymphocytes (PBLs). Human umbilical vein endothelial cells (HUVECs) and UKF-NB-4 neuroblastoma tumor cells were established in coculture on opposite sides of porous transwell filters. After 24 hours with and without HUVEC conditioning, PMNs or PBLs were added to the HUVEC monolayer. Adhesion to conditioned HUVEC versus adhesion to nonconditioned HUVEC was compared. Effects on endothelial CD44v4, CD44v5, CD44v7, intercellular adhesion molecule 1 (ICAM-1), E-selectin, and vascular cell adhesion molecule 1 (VCAM-1) adhesion receptor expression were analyzed by flow cytometry, intracellular signaling proteins of the mitogen-activated protein kinase pathway and protein kinase C (PKC) subtypes quantified by Western blot analysis. Endothelial conditioning led to a distinct reduction in PMN but not in PBL adhesion to HUVEC. CD44 was significantly reduced, whereas ICAM-1, E-selectin, and VCAM-1 were not altered during HUVEC conditioning. Antibody blockade against CD44v4, CD44v5, and CD44v7 inhibited PMN but not PBL binding. The observed effects were caused by direct tumor cell-HUVEC contact because addition of isolated tumor cell membrane fragments but not of soluble cell culture supernatant to HUVEC induced the CD44 receptor loss. PKCalpha activity was strongly enhanced in conditioned HUVEC. Blocking PKC prevented the reduction in PMN binding, indicating that this protein is involved in PMN adhesion regulation. A novel tumor escape strategy is presented here. Cell contact-dependent adhesion of tumor cells to the vascular wall promotes down-regulation of endothelial CD44 receptor expression, impairing an effective neutrophil attack.

Combining the receptor tyrosine kinase inhibitor AEE788 and the mammalian target of rapamycin (mTOR) inhibitor RAD001 strongly inhibits adhesion and growth of renal cell carcinoma cells.

BACKGROUND: Treatment options for metastatic renal cell carcinoma (RCC) are limited due to resistance to chemo- and radiotherapy. The development of small-molecule multikinase inhibitors has now opened novel treatment options. We evaluated the influence of the receptor tyrosine kinase inhibitor AEE788, applied alone or combined with the mammalian target of rapamycin (mTOR) inhibitor RAD001, on RCC cell adhesion and proliferation in vitro. METHODS: RCC cell lines Caki-1, KTC-26 or A498 were treated with various concentrations of RAD001 or AEE788 and tumor cell proliferation, tumor cell adhesion to vascular endothelial cells or to immobilized extracellular matrix proteins (laminin, collagen, fibronectin) evaluated. The anti-tumoral potential of RAD001 combined with AEE788 was also investigated. Both, asynchronous and synchronized cell cultures were used to subsequently analyze drug induced cell cycle manipulation. Analysis of cell cycle regulating proteins was done by western blotting. RESULTS: RAD001 or AEE788 reduced adhesion of RCC cell lines to vascular endothelium and diminished RCC cell binding to immobilized laminin or collagen. Both drugs blocked RCC cell growth, impaired cell cycle progression and altered the expression level of the cell cycle regulating proteins cdk2, cdk4, cyclin D1, cyclin E and p27. The combination of AEE788 and RAD001 resulted in more pronounced RCC growth inhibition, greater rates of G0/G1 cells and lower rates of S-phase cells than either agent alone. Cell cycle proteins were much more strongly altered when both drugs were used in combination than with single drug application. The synergistic effects were observed in an asynchronous cell culture model, but were more pronounced in synchronous RCC cell cultures. CONCLUSION: Potent anti-tumoral activitites of the multikinase inhibitors AEE788 or RAD001 have been demonstrated. Most importantly, the simultaneous use of both AEE788 and RAD001 offered a distinct combinatorial benefit and thus may provide a therapeutic advantage over either agent employed as a monotherapy for RCC treatment.

Expression of angiogenesis inhibitors in human bladder cancer may explain rapid metastatic progression after radical cystectomy.

Angiogenesis is essential for tumor growth and progression. It has been demonstrated that the expression of angiogenesis stimulators (e.g. basic fibroblast growth factor and vascular endothelial growth factor) correlates to tumor progression in various human tumor types. Furthermore, endogenous angiogenesis inhibitors (e.g. angiostatin and endostatin) have been isolated from human tumor models and have been successfully used to treat tumors in mice and humans. In the present study, the expression of angiostatin, endostatin and thrombospondin-1 in four different human bladder cancer cell lines with different tumorigenic potential (MGH-U4, RT-4, RT-112 and UMUC-3) were investigated. A subset of bladder carcinoma patients demonstrates rapid metastatic progression after removal of the primary tumor, although no evidence of metastasis is diagnosed before the surgical procedure. A potential mechanism to explain this phenomenon is suggested. Angiostatin, endostatin and thrombospondin-1 was detected in the conditioned media of four human bladder cancer cell lines using Western blotting. Angiostatin was purified and amino acid sequenced via mass spectrometry. The biological activity of angiostatin was determined by proliferation assays using endothelial cells, smooth muscle cells and fibroblasts. Tumor characteristics of the four human bladder carcinoma models were investigated in vitro and in vivo. All the bladder carcinoma cell lines employed in this study produced two biologically active variants of the angiostatin molecule (38 and 49 kDa). Endostatin and thrombospondin-1 were only produced by the low malignancy MGH-U4 and RT-4 bladder carcinoma models. This study identified the expression of different antiangiogenic molecules in human bladder carcinoma. The expression of antiangiogenic molecules seems to be a characteristic of low malignancy bladder carcinomas. The sudden lack of expression of antiangiogenic molecules as a consequence of surgical removal of highly malignant bladder carcinomas may explain the rapid metastatic progression of a subset of bladder carcinomas.

The histone deacetylase inhibitor valproic acid alters growth properties of renal cell carcinoma in vitro and in vivo.

Histone deacetylase (HDAC) inhibitors represent a promising class of antineoplastic agents which affect tumour growth, differentiation and invasion. The effects of the HDAC inhibitor valproic acid (VPA) were tested in vitro and in vivo on pre-clinical renal cell carcinoma (RCC) models. Caki-1, KTC-26 or A498 cells were treated with various concentrations of VPA during in vitro cell proliferation 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assays and to evaluate cell cycle manipulation. In vivo tumour growth was conducted in subcutaneous xenograft mouse models. The anti-tumoural potential of VPA combined with low-dosed interferon-alpha (IFN-alpha) was also investigated. VPA significantly and dose-dependently up-regulated histones H3 and H4 acetylation and caused growth arrest in RCC cells. VPA altered cell cycle regulating proteins, in particular CDK2, cyclin B, cyclin D3, p21 and Rb. In vivo, VPA significantly inhibited the growth of Caki-1 in subcutaneous xenografts, accompanied by a strong accumulation of p21 and bax in tissue specimens of VPA-treated animals. VPA-IFN-alpha combination markedly enhanced the effects of VPA monotherapy on RCC proliferation in vitro, but did not further enhance the anti-tumoural potential of VPA in vivo. VPA was found to have profound effects on RCC cell growth, lending support to the initiation of clinical testing of VPA for treating advanced RCC.

Valproic acid blocks adhesion of renal cell carcinoma cells to endothelium and extracellular matrix.

Treatment strategies for metastatic renal cell carcinoma (RCC) have been limited due to chemotherapy and radiotherapy resistance. The development of targeted drugs has now opened novel therapeutic options. In the present study, anti-tumoral properties of the histone deacetylase inhibitor valproic acid (VPA) were tested in vitro and in vivo on pre-clinical RCC models. RCC cell lines Caki-1, KTC-26 or A498 were treated with various concentrations of VPA to evaluate tumour cell adhesion to vascular endothelial cells or to immobilized extracellular matrix proteins. In vivo tumour growth was conducted in subcutaneous xenograft mouse models. VPA was also combined with low dosed interferon-alpha (IFN-alpha) and the efficacy of the combination therapy, as opposed to VPA monotherapy, was compared. VPA significantly and dose-dependently prevented tumour cell attachment to endothelium or matrix proteins, accompanied by elevated histones H3 and H4 acetylation. VPA altered integrin-alpha and -beta subtype expression, in particular alpha(3), alpha(5) and beta(3), and blocked integrin-dependent signalling. In vivo, VPA significantly inhibited the growth of Caki-1 in subcutaneous xenografts with the 200 mg/kg being superior to the 400 mg/kg dosing schedule. VPA-IFN-alpha combination markedly enhanced the effects of VPA on RCC adhesion, and in vivo tumour growth was further reduced by the 400 mg/kg but not by the 200 mg/kg VPA dosing schedule. VPA profoundly blocked the interaction of RCC cells with endothelium and extracellular matrix and reduced tumour growth in vivo. Therefore, VPA should be considered an attractive candidate for clinical trials.

Modulation of adhesion and growth of colon and pancreatic cancer cells by the histone deacetylase inhibitor valproic acid.

Histone deacetylase (HDAC) inhibitors belong to a promising class of antineoplastic agents which affect tumor growth, differentiation and invasion. The effects of the HDAC inhibitor valproic acid (VPA) were tested in vitro on preclinical colon and pancreatic cancer models. Human colon adenocarcinoma HT-29 and pancreatic carcinoma DanG cells were treated with 1 mM VPA for different time periods during cell proliferation MTT assays, and to evaluate the tumor cell adhesion to endothelial cell monolayers. Alterations of beta1 integrin subunits alpha1-6) were analyzed by flow cytometry and RT-PCR. VPA significantly caused growth arrest in tumor cells and prevented tumor cell attachment to the endothelium. HT-29 cell adhesion was blocked to a higher extent than the adhesion of DanG cells. VPA modified membranous integrin beta1 expression, quantity and quality (up- or down-regulation) which depended on the tumor type investigated. Furthermore, VPA diminished integrin coding mRNA in HT-29 but not in DanG cells. We conclude that VPA shifts the integrin beta1 subunit balance from a 'pathological' towards a 'physiological' expression pattern leading to reduced tumor growth and invasion. Further study is required to elucidate the molecular background of the post-transcriptional modifications of VPA in order to exploit the potential of this agent in the treatment of colon and pancreatic cancer.

Autocrine stimulation of human hepatocytes triggers late DNA synthesis and stabilizes long-term differentiation in vitro.

Isolated human hepatocytes are of great value in investigating cell transplantation, liver physiology, pathology, and drug metabolism. Though hepatocytes possess a tremendous proliferative capacity in vivo, their ability to grow in culture is severely limited. We postulated that repeated medium change, common to most in vitro systems, may prevent long-term maintenance of hepato-specific functions and growth capacity. To verify our hypotheses we compared the DNA synthesis and differentiation status of isolated human hepatocytes, cultured in medium which was renewed every day or was not changed for 3 weeks ('autocrine' setting). Daily medium change led to rapid hepatocellular de-differentiation without any signs of DNA replication. In contrast, the autocrine setting allowed hepatocytes to become highly differentiated, demonstrated by an elevated ASGPr expression level, and increased albumin and fibrinogen synthesis and release. Cytokeratin 18 filaments were stably expressed, whereas cytokeratin 19 remained undetectable. Hepatocytes growing in an autocrine fashion were activated in the presence of hepatocyte growth factor (HGF), evidenced by c-Met phosphorylation. However, HGF response was not achieved when the culture medium was renewed daily. Furthermore, the autocrine setting evoked a late but strong interleukin 6 release into the culture supernatant, reaching maximum values after a 10-day cultivation period, and intense BrdU incorporation after a further 5-day period. Our data suggest that preservation of the same medium creates environmental conditions which allow hepatocytes to control their differentiation status and DNA synthesis in an autocrine fashion. Further studies are necessary to identify the key mediators involved in autocrine communication and to design the optimal culture configuration for clinical application.

Effect of procurement-related organ lesions on renal transplant outcome.

BACKGROUND: The purpose of our study was to examine the nature and incidence of renal injuries during organ procurement, to identify risk factors and to analyse the effects of organ lesions on the following transplantation. METHODS: All cadaveric kidney transplantations performed at our centre from 1996 to 2006 with an organ donated within the Eurotransplant (ET) region were retrospectively analysed. RESULTS: Five hundred and sixty-three renal grafts procured in 62 centres throughout the ET region were transplanted in the analysed period. One hundred and twenty (21.3%) kidneys were inadequately procured with 143 errors in total. The frequency of procurement errors did not differ significantly between kidneys procured by urologists and general surgeons (19.2% vs. 24.6%) nor when kidneys were procured alone or together with pancreas and/or liver (19.3% vs. 22.0%). Inadequate procurement lead to a discard rate of 0.2% and ultimately resulted in a surgical complication rate of 3.4%. Primary graft function (75.8% vs. 78.6%), three-yr graft survival (76.6% vs. 82.4%) and cumulated long-term graft survival were not significantly influenced by procurement errors. CONCLUSION: Additional measures to improve procurement quality are necessary. Nevertheless, adequate repair of organ lesions is possible and most organs can be successfully transplanted with very good short- and long-term results.

Renal transplantation in the elderly: surgical complications and outcome with special emphasis on the Eurotransplant Senior Programme.

BACKGROUND: The purpose of this retrospective study was to evaluate the results of the Eurotransplant Senior Programme (ESP) within our centre compared to elderly recipients >or=60 years from the regular Eurotransplant Kidney Allocation System (ETKAS), specifically focusing on surgical aspects. METHODS: Data from 73 ESP patients (average donor/recipient age: 71.1/67.1) were compared with those from 51 patients (49.7/63.6) treated within the framework of the ETKAS program between the years 1999 and 2006. The mean follow-up was 39.5 months. RESULTS: Cold ischaemic time (ESP versus ETKAS: 10.3 versus 15.0 h), duration of renal replacement therapy (42.2 versus 76.8 months), donor glomerular filtration rate (81.7 versus 109.9 ml/min/1.73 m(2)) and HLA mismatches (4.1 versus 2.4) were significantly different between the two groups (all P < 0.001). Primary graft function was seen in 74% ESP versus 69% of ETKAS patients (P > 0.05). The rate of surgical complications in the ESP versus ETKAS group was 47% versus 28% (P = 0.031) and the revision rate, 33% versus 24% (P = 0.259). Three-year patient and censored graft survival was 84% versus 92% and 85% versus 88% in the ESP and ETKAS group, respectively (all P > 0.05). Ninety-five percent of all deceased patients died with a functioning graft. CONCLUSIONS: The donor and recipient pool has been markedly expanded through ESP with similar patient and graft survival compared to elderly recipients grafted according to ETKAS criteria. However, patients and their physicians should be aware of the high surgical complication rate in elderly recipients, particularly when receiving elderly donor kidneys. This might seriously influence postoperative patient management but ultimately does not compromise the transplant outcome.

CXC chemokine mRNA expression as a potential diagnostic tool in prostate cancer.

In vitro models have suggested that chemokines of the CXC family may regulate prostate cancer cell proliferation and dissemination. In this study, we evaluated the expression of CXC receptors (CXCRs) and CXC ligands (CXCLs) in prostate cancer tissue. CXCL1-16 and CXCR1-6 mRNA were identified by RT-PCR in prostate tumors and adjacent normal tissue specimens. Samples were obtained from 49 patients undergoing radical prostatectomy. mRNA expression was semiquantitatively scored and correlated with pretreatment prostate-specific antigen (PSA), the Gleason score, early patient follow-up and Kattan postoperative prediction. CXCL12 mRNA expression level was significantly enhanced, whereas CXCL13 was reduced in prostate tumor compared to adjacent 'normal' tissue. No differences were observed in the CXCR4 mRNA level; however, both CXCR3 and CXCR5 were reduced significantly in the tumor tissue. The difference in CXCL12 and CXCL13 (CXCLΔ) correlated significantly with PSA levels and the Gleason score. Furthermore, CXCLΔ correlated significantly with the Kattan postoperative nomogram. Tumor progression was observed in patients with high CXCLΔ values, but not in those with low values, in early follow-up. The development and progression of prostate cancer was accompanied by alterations of CXC chemokine expression, in particular CXCL12, CXCL13, CXCR3 and CXCR5. Novel treatment options could therefore be targeted at one or several of these proteins. The practicability of CXC chemokines as potential prognostic markers requires further study.

Transient down-regulation of beta1 integrin subtypes on kidney carcinoma cells is induced by mechanical contact with endothelial cell membranes.

Adhesion molecules of the integrin beta1 family are thought to be involved in the malignant progression renal cell carcinoma (RCC). Still, it is not clear how they contribute to this process. Since the hematogenous phase of tumour dissemination is the rate-limiting step in the metastatic process, we explored beta1 integrin alterations on several RCC cell lines (A498, Caki1, KTC26) before and after contacting vascular endothelium in a tumour-endothelium (HUVEC) co-culture assay. Notably, alpha2, alpha3 and alpha5 integrins became down-regulated immediately after the tumour cells attached to HUVEC, followed by re-expression shortly thereafter. Integrin down-regulation on RCC cells was caused by direct contact with endothelial cells, since the isolated endothelial membrane fragments but not the cell culture supernatant contributed to the observed effects. Integrin loss was accompanied by a reduced focal adhesion kinase (FAK) expression, FAK activity and diminished binding of tumour cells to matrix proteins. Furthermore, intracellular signalling proteins RCC cells were altered in the presence of HUVEC membrane fragments, in particular 14-3-3 epsilon, ERK2, PKCdelta, PKCepsilon and RACK1, which are involved in regulating tumour cell motility. We, therefore, speculate that contact of RCC cells with the vascular endothelium converts integrin-dependent adhesion to integrin-independent cell movement. The process of dynamic integrin regulation may be an important part in tumour cell migration strategy, switching the cells from being adhesive to becoming motile and invasive.

CXCR4 chemokine receptor engagement modifies integrin dependent adhesion of renal carcinoma cells.

The mechanisms leading to renal cell carcinoma (RCC) metastasis are incompletely understood. Although evidence shows that the chemokine receptor CXCR4 and its ligand CXCL12 may regulate tumor dissemination, their role in RCC is not clearly defined. We examined CXCR4 expression and functionality on RCC cell lines, and explored CXCL12-triggered tumor adhesion to human endothelium (HUVEC) or extracellular matrix proteins. Functional CXCR4 was expressed on A498 tumor cells, enabling them to migrate towards a CXCL12 gradient. CXCR4 engagement by CXCL12 induced elevated cell adhesion to HUVEC, to immobilized fibronectin, laminin or collagen. Anti-CXCR4 antibodies or CXCR4 knock down by siRNA applied prior to CXCL12 stimulation impaired CXCL12-triggered tumor adhesion. However, blocking CXCR4 subsequent to CXCL12 stimulation did not. This pointed to an indirect control of tumor cell adhesion by CXCR4. In fact, CXCR4 engagement by CXCL12 also induced alterations of receptors of the integrin family, notably alpha3, alpha5, beta1 and beta3 subunits, and blocking beta1 integrins with a function-blocking antibody prevented CXCL12-induced A498 adhesion. Focal adhesion kinase (total and activated) and integrin-linked kinase significantly increased in CXCL12-treated A498 cells, accompanied by a distinct up-regulation of ERK1/2, JNK and p38 phosphorylation. Therefore, CXCR4 may be crucial in controlling adhesion of A498 cells via cross talking with integrin receptors. These data show that CXCR4 receptors contribute to RCC dissemination and may provide a novel link between CXCR4 chemokine receptor expression and integrin triggered RCC adhesion to the vascular wall and subendothelial matrix components.

Chemoresistance induces enhanced adhesion and transendothelial penetration of neuroblastoma cells by down-regulating NCAM surface expression.

BACKGROUND: Drug resistance to chemotherapy is often associated with increased malignancy in neuroblastoma (NB). One explanation for the link between resistance and malignancy might be that resistance facilitates cancer progression and invasion. To investigate this hypothesis, adhesion, transendothelial penetration and NCAM (CD56) adhesion receptor expression of drug-resistant versus drug-sensitive NB tumor cells were evaluated. METHODS: Acquired drug resistance was mimicked by exposing parental UKF-NB-2, UKF-NB-3 or IMR-32 tumor cells to increasing concentrations of vincristine- (VCR) or doxorubicin (DOX) to establish the resistant tumor cell sublines UKF-NB-2VCR, UKF-NB-2DOX, UKF-NB-3VCR, UKF-NB-3DOX, IMR-32VCR and IMR-32DOX. Additionally, the malignant behaviour of UKF-NB-4, which already possessed the intrinsic multidrug resistance (MDR) phenotype, was analyzed. UKF-NB-4 exposed to VCR or DOX were designated UKF-NB-4VCR or UKF-NB-4DOX. Combined phase contrast - reflection interference contrast microscopy was used to separately evaluate NB cell adhesion and penetration. NCAM was analyzed by flow cytometry, western blot and RT-PCR. RESULTS: VCR and DOX resistant tumor sublines showed enhanced adhesion and penetration capacity, compared to their drug naïve controls. Strongest effects were seen with UKF-NB-2VCR, UKF-NB-3VCR and IMR-32DOX. DOX or VCR treatment also evoked increased invasive behaviour of UKF-NB-4. The process of accelerated tumor invasion was accompanied by decreased NCAM surface and protein expression, and down-regulation of NCAM coding mRNA. Transfection of UKF-NB-4VCR cells with NCAM cDNA led to a significant receptor up-regulation, paralleled by diminished adhesion to an endothelial cell monolayer. CONCLUSION: It is concluded that NB cells resistant to anticancer drugs acquire increased invasive capacity relative to non-resistant parental cells, and that enhanced invasion is caused by strong down-regulation of NCAM adhesion receptors.

Human cytomegalovirus infection alters PC3 prostate carcinoma cell adhesion to endothelial cells and extracellular matrix.

The genome and antigens of human cytomegalovirus (HCMV) are frequently found in prostatic carcinoma. However, whether this infection is causative or is an epiphenomenon is not clear. We therefore investigated the ability of HCMV to promote metastatic processes, defined by tumor cell adhesion to the endothelium and extracellular matrix proteins. Experiments were based on the human prostate tumor cell line PC3, either infected with the HCMV strain Hi (HCMV(Hi)) or transfected with cDNA encoding the HCMV-specific immediate early protein IEA1 (UL123) or IEA2 (UL122). HCMV(Hi) upregulated PC3 adhesion to the endothelium and to the extracellular matrix proteins collagen, laminin, and fibronectin. The process was accompanied by enhancement of beta(1)-integrin surface expression, elevated levels of integrin-linked kinase, and phosphorylation of focal adhesion kinase. IEA1 or IEA2 did not modulate PC3 adhesion or beta(1)-integrin expression. Based on this in vitro model, we postulate a direct association between HCMV infection and prostate tumor transmigration, which is not dependent on IEA proteins. Integrin overexpression, combined with the modulation of integrin-dependent signalling, seems to be, at least in part, responsible for a more invasive PC3(Hi) tumor cell phenotype. Elevated levels of c-myc found in IEA1-transfected or IEA2-transfected PC3 cell populations might promote further carcinogenic processes through accelerated cell proliferation.