Intercellular adhesion molecule-1 expression by bladder cancer cells: functional effects

Impacts of ICAM-1 gene polymorphisms on urothelial cell carcinoma susceptibility and clinicopathologic characteristics in Taiwan

Intercellular adhesion molecule (ICAM)-1, a cell adhesion molecule, is reportedly overexpressed in several cancers and may contribute to tumorgenesis and metastasis. The current study explored the effect of ICAM-1 gene polymorphisms on the susceptibility of developing urothelial cell carcinoma (UCC) and the clinicopathological status. A total of 558 participants, including 279 healthy people and 279 patients with UCC, were recruited for this study. Four single-nucleotide polymorphisms of the ICAM-1 gene were assessed by a real-time polymerase chain reaction with the TaqMan assay. After adjusting for other covariants, the individuals carrying at least one G allele at ICAM-1 rs5498 had a 1.603-fold risk of developing UCC than did wild-type (AA) carriers. Furthermore, UCC patients who carried at least one G allele at rs5498 had a higher invasive stage risk (p < 0.05) than did patients carrying the wild-type allele. In conclusion, the rs5498 polymorphic genotypes of ICAM-1 might contribute to the prediction of susceptibility to and pathological development of UCC. This is the first study to provide insight into risk factors associated with ICAM-1 variants in carcinogenesis of UCC in Taiwan.

Potential immunologic effects of statins in cancer following transplantation

3-hydroxy-3-methyglutaryl CoA reductase inhibitors (statins) are frequently used following organ transplantation and have well reported pleiotropic effects, including immunomodulation, which may be of benefit in preventing graft rejection. However, the immunomodulatory effects of statins on cell transformation and malignancy, combined with the immunologic processes and administration of immunosuppression are almost completely unknown. The administration of immunosuppression is well recognised as the main cause of cancer following transplantation, so the addition of an immunomodulatory agent should be associated with an increased incidence of cancer, as immune surveillance and response may be suppressed, allowing cellular transformation and proliferation combined with lack of recognition to occur. This hypothetical review attempts to delineate the mode of action of statins in terms of pro/anti-carcinogenic mechanisms, while considering graft rejection and the presence of immunosuppression.

Correlation between the Serum Values of Soluble Intercellular Adhesion Molecule-1 and Total Sialic Acid Levels in Patients with Breast Cancer

BACKGROUND

In this study, we aimed to investigate serum total sialic acid (TSA) and soluble intracellular adhesion molecule-1 (sICAM-1) levels in breast cancer patients to find a correlation with the cancer stage.

METHODS

The parameters from sera of 61 patients with breast cancer were measured. The concentrations of serum sICAM-1 and TSA were measured in serum samples from 61 patients with breast cancer and 25 healthy control subjects using enzyme-linked immunoassay and thiobarbituric acid method.

RESULTS

Mean serum sICAM-1 and TSA levels were significantly higher in the total patient group than in the control group (p < 0.001). Thus, the correlation between TSA and sICAM-1 became more significant in metastatic breast cancer. There were significant positive correlations between TSA and sICAM-1 in stage I+II (r = 0.59, p < 0.05), stage III (r = 0.47, p < 0.05), and stage IV (r = 0.89, p < 0.01), and total patient group (r = 0.56, p < 0.001).

CONCLUSION

SerumsICAM-1 and TSA levels were higher in patients with breast cancer, than that of the control group, and also in the metastatic breast cancer group. Significant correlations between serum sICAM-1 and TSA may reflect the similar function of these molecules as adhesion molecules, and their roles in the carcinogenesis of breast cancer as well as metastasis.

The relationship between the serum intercellular adhesion molecule-1 level and the prognosis of the disease in lung cancer

BACKGROUND

Adhesion molecules are related to cell-to-cell interaction and inflammatory interaction. In addition, adhesive interactions between tumor cells and adjacent cells and/or extracellular matrix play important roles in the complex process of tumor growth and development. Among these adhesion molecules, expression of intercellular adhesion molecule-1 (ICAM-1) has been identified in colon cancer, bladder cancer, lung cancer, melanoma, pancreatic cancer and hepatocellular carcinoma. In the current study, we analyzed serum ICAM-1 concentrations to investigate the relationship between the serum ICAM-1 level and prognosis in patients with lung cancer.

METHODS

Serum ICAM-1 was measured in 84 patients with lung cancer according to the pathologic type and clinical stage using the ICAM-1 ELISA kit. The Kaplan-Meier method was used to analyse survival time.

RESULTS

There was no difference in serum ICAM-1 concentration among the different stages of lung cancer. Furthermore, there was no difference observed between histologic tumor type with regard to serum ICAM-1 concentration. Although the difference was not significant, the overall survival times of patients with a low serum ICAM-1 concentration (< 306 ng/mL) was longer than that of patients with a high concentration (> or = 306 ng/mL) in non-small cell lung cancer patients.

CONCLUSION

These results suggest that high levels of serum ICAM-1 reflect poor prognosis for patients with non-small cell lung cancer.

Adhesion molecules in human pancreatic cancer

BACKGROUND AND OBJECTIVES

Adhesion molecules are cell surface glycoproteins that are important in cell-to-cell and cell-to-extracellular matrix interactions. In the present study, we analyzed the adhesion molecules ICAM-1 (intercellular adhesion molecule-1), VCAM-1 (vascular cell adhesion molecule-1), and ELAM-1 (endothelial leukocyte adhesion molecule-1) in human pancreatic cancer.

METHODS

ICAM-1, VCAM-1, and ELAM-1 were analyzed in 20 pancreatic cancer specimens and 20 normal pancreatic tissues. mRNA expression encoding ICAM-, VCAM-1, and ELAM-1 was assessed with Northern blot analysis. The distribution and localization of ICAM-1, VCAM-1, and ELAM-1 was determined in the pancreatic specimens by immunohistochemistry.

RESULTS

Northern blot analysis revealed a 5.4-fold increase of ICAM-1 (P<0.01) and a 3.7-fold increase in VCAM-1 (P<0.01) mRNA expression in cancer samples in comparison with normal controls. In contrast, ELAM-1 mRNA levels did not show significant differences between the cancer and the normal tissues. Immunohistochemical analysis of cancer tissues showed strong immunostaining for ICAM-1 and VCAM-1, and faint immunostaining for ELAM-1 in the pancreatic cancer cells. Fibrotic or noncancerous pancreatic tissue adjacent to the cancer mass was devoid of any immunoreactivity for ICAM-1, ELAM-1, and VCAM-1. In contrast, the normal pancreas exhibited no immunoreactivity of ICAM-1, ELAM-1, and VCAM-1.

CONCLUSIONS

Enhanced expression of ICAM-1 and VCAM-1 in human pancreatic cancers suggests a role in tumor pathogenesis. The increase of these adhesion molecules might influence the detachment of cancer cells in the primary tumor, might contribute to cancer cell migration and the spread of cancer cells to distant organs, or both.

Surface antigen expression on bladder tumor cells induced by bacillus Calmette-Guérin (BCG): A role of BCG internalization into tumor cells

BACKGROUND

The antitumor mechanisms of bacillus Calmette-Guérin (BCG) against bladder cancer is still unclear. We previously reported that BCG was internalized by and survived within murine bladder tumor cells (MBT-2) for at least 40 days. In the present study, we investigated the effect of BCG on the surface antigen expression of bladder tumor cells and the characteristics of these cells as antigen-presenting cells in vitro.

METHODS

Surface antigen (major histocompatibility complex (MHC) Class II, CD1, CD80 and intercellular adhesion molecule-1 (ICAM-1)) expression on BCG-treated murine (MBT-2) and human (T-24, J82) bladder tumor cells were analyzed using flow cytometry. The production of interleukin-2 (IL-2) and interferon-gamma (IFN-gamma) from murine lymphocytes sensitized with BCG or BCG-treated tumor cells were also investigated.

RESULTS

The expressions of MHC Class II, CD1, CD80 and ICAM-1 were augmented in all of the bladder tumor cell lines used; however, they were augmented to varying degrees among the cell lines that were treated with live BCG. Heat-killed BCG had little or no effect. When murine lymph node cells sensitized with BCG or BCG-treated MBT-2 cells were cocultured with BCG-treated MBT-2 cells, significant amounts of IL-2 and IFN-gamma were produced in the culture medium.

CONCLUSIONS

BCG induced the augmented expression of surface antigens, such as MHC Class II, CD1, CD80 and ICAM-1, of bladder tumor cells. Furthermore, BCG-treated MBT-2 cells could stimulate BCG-sensitized lymphocytes to produce IL-2 and IFN-gamma. These results strongly suggest that bladder tumor cells gained the characteristics and functions of antigen-presenting cells (APC).

Molecular aspects of bladder cancer III. Prognostic markers of bladder cancer

The current pathological and clinical parameters provide important prognostic information, yet still have limited ability to predict the true malignant potential of most bladder tumors. In the last years, investigation of the basic mechanisms involved in carcinogenesis and tumor progression by molecular biology has provided a host of markers which are of potential diagnostic or prognostic value for bladder carcinoma. These markers may serve as tools for early and accurate prediction of tumor recurrence, progression and development of metastases and for prediction of response to therapy. The precise prediction of tumor biological behavior would facilitate treatment selection for patients who may benefit from radical surgical treatment or adjuvant therapy. We provide a current, comprehensive review of the literature on bladder tumor markers with a special emphasis on their prognostic potential. The literature suggests that currently no single marker is able to accurately predict the clinical course of bladder tumors and thus would serve as a reliable prognosticator. A combination of prognostic markers could predict which superficial tumors need an aggressive form of therapy and which invasive tumors require adjuvant therapy. Altogether, the most promising markers are, at this point, Ki-67 and p53 expression as well as matrixmetalloproteinase complex and angiogenesis.

Evaluation of cellular tumour rejection mechanisms in the peritumoral bladder wall after bacillus Calmette-Guérin treatment

OBJECTIVE

To compare the immunological status of normal and peritumoral bladder walls, and to characterize immunocompetent cells before and during intravesical instillations of bacillus Calmette-Guérin (BCG).

PATIENTS AND METHODS

Twenty-three patients with superficial urothelial bladder carcinoma (stages pTa to pT1, grades 1-3) were treated with six weekly instillations of 150 mg of BCG (Pasteur strain). Biopsies of cystoscopically normal bladder wall were taken before, 3 weeks and 3 months after BCG instillation. The controls comprised bladder biopsy specimens from 13 brain-dead ventilated kidney donors. Local infiltrating cell types, i.e. lymphocyte infiltrates (CD4, CD8, CD20, CD3, interleukin-2-receptor-positive, natural killer, gammadelta), macrophages and dendritic cells, adhesion and costimulatory molecules (ICAM-1 and B7-BB1) and major histocompatibility complex (MHC) class I and class II antigens were assessed using semi-quantitative immunohistochemical analysis.

RESULTS

Before BCG the peritumoral bladder wall had fewer macrophages than control bladder wall. BCG treatment restored normal numbers of macrophages and enhanced T helper lymphocytes, B lymphocytes, natural killer cells, activated lymphocytes, dendritic cells, normal MHC class I, adhesion (ICAM-1) and costimulatory (B7-BB1) expression. The enhancement of these immunological variables was transient, with a return to baseline 3 months after BCG instillation.

CONCLUSIONS

These results support the concept that there is a host-immune escape associated with bladder cancer. BCG therapy may temporarily restore impaired tumour rejection mechanisms in the peritumoral bladder wall, suggesting a need for maintenance therapy after the first course of BCG.

Role of IL-12 in the Induction and Potentiation of IFN-γ in Response to Bacillus Calmette-Guérin

Although Mycobacterium bovis bacillus Calmette-Guérin (BCG) has been accepted as the most effective agent in clinical use against superficial bladder cancer, its mechanism of action remains incompletely understood. A kinetic analysis in assessing the potential role of cytokines from BCG-stimulated murine splenocytes showed that IL-12 expression preceded that of other cytokines. Experiments subtracting endogenous BCG-driven IL-12 using neutralizing Ab or augmenting its activity with supplemental rIL-12 revealed not only that IL-12 plays a dominant role in IFN-γ induction but also that it is normally dose limiting. A striking increase in IFN-γ production could be generated in both mouse and human immunocompetent cell culture by the addition of even a small amount of rIL-12. Moreover, this same synergistic effect could be replicated during in vivo administration of BCG plus rIL-12 into the mouse bladder and was observed in a patient receiving intravesical combination therapy. In costimulation cultures, this synergy appeared to partially rely on IL-18 and IL-2 and could be down-regulated by IL-10. This suggests that a dynamic interplay between Th1 and Th2 cytokines is responsible for net IFN-γ production. The ability of supplemental exogenous IL-12 to strongly shift this balance toward Th1 provides an immunological basis for using it in conjunction with intravesical BCG for bladder cancer immunotherapy.

Involvement of LFA-1 in hepatic NK cell (pit cell)-mediated cytolysis and apoptosis of colon carcinoma cells

BACKGROUND/AIMS

Previous studies have shown that hepatic natural killer (NK) cells, also called pit cells, have a higher cytotoxicity against certain tumor cells and have a higher expression of the cell adhesion molecule CD11a as compared with blood NK cells. We further investigated the involvement of the adhesion molecules, reported to be involved in target cell killing by blood NK cells, in pit cell-mediated colon carcinoma cell killing.

METHODS

51Cr-release and DNA fragmentation were used to quantify target cell lysis and apoptosis, respectively. Adhesion of pit cells to CC531s monolayers was quantitated.

RESULTS

Flow cytometric analysis showed that pit cells expressed CD2, CD11a, CD18 and CD54. CC531s cells expressed only CD54. Treatment of freshly isolated pit cells with monoclonal antibodies (mAbs) to CD11a and CD18 inhibited not only the pit cell-mediated CC531s cytolysis but also the pit cell-induced apoptosis of CC531s cells. The combination of mAbs to CD11a, CD18 and CD54 further increased the inhibition of pit cell-mediated CC531s cytolysis and apoptosis. Anti-CD2 mAb did not affect these processes. The binding of pit cells to CC531s cells was also inhibited by anti-CD11a, and CD18 mAbs, but not by anti-CD2 mAb. Anti-CD54 mAb reduced the target cell killing and the binding only slightly.

CONCLUSIONS

These results indicate that CD11a/CD18 (LFA-1) present on pit cells plays an important role in pit cell-mediated target cell adhesion, lysis and apoptosis. This finding might explain why pit cells, which have a higher expression of LFA-1 as compared to blood NK cells, are more cytotoxic against tumor cells as compared to blood NK cells.

Role of adhesion molecules in bladder cancer: an important part of the jigsaw

There is a growing body of evidence suggesting that alterations in the adhesion properties of neoplastic cells may play a pivotal role in the development and progression of bladder cancer. Loss of intercellular adhesion and the desquamation of cells from the underlying lamina propria allows malignant cells to escape from their site of origin, degrade the extracellular matrix, acquire a more motile and invasive phenotype, and finally invade and metastasize. In addition to participating in tumor invasiveness and metastasis, adhesion molecules regulate or significantly contribute to a variety of functions, including signal transduction, cell growth, differentiation, site-specific gene expression, morphogenesis, immunologic function, cell motility, wound healing, and inflammation. To date, a diverse system of transmembrane glycoproteins have been identified that mediate the cell-cell and the cell-extracellular matrix adhesion. The main families of adhesion molecules are the cadherins, integrins, members of the immunoglobulin superfamily, and selectins. We review the recent data regarding the role of selected adhesion molecules in the pathogenesis of bladder cancer and their clinical exploitation as biomarkers of this malignant disease.

Enhancing the immunotherapeutic potential of mycobacteria by transfection with tumour necrosis factor-alpha

In an attempt to enhance the anti-tumour properties of mycobacteria we have developed recombinant forms of Mycobacterium smegmatis which express and secrete biologically active human tumour necrosis factor-alpha (TNF-alpha). This was achieved by transfecting M. smegmatis using shuttle plasmids incorporating the cDNA sequence for the human TNF-alpha mature peptide. In vitro experiments on a panel of human bladder tumour cell lines (EJ18, MGH-U1, RT4, RT112) indicate that our genetically modified mycobacteria are more effective than wild-type at inducing or up-regulating the expression of intracellular adhesion molecule-1 and the secretion of an array of proinflammatory cytokines [interleukin-1 (IL-1), IL-6, IL-8, granulocyte-macrophage colony-stimulating factor]. We have also demonstrated increased adhesion molecule and cytokine expression in response to mycobacteria transfected with vector containing no gene insert. However, this was not as pronounced as that observed following tumour cell stimulation by the TNF-alpha-transfected strain. In contrast, in three out of four tumour cell lines all M. smegmatis strains were found to down-regulate the secretion of the anti-inflammatory cytokine transforming growth factor-beta1. Our studies have also confirmed that M. smegmatis is a powerful inhibitor of bladder tumour cell growth and revealed that its antiproliferative potency is enhanced by transfecting with human TNF-alpha and, to a lesser extent, with vector alone. All M. smegmatis strains were effective in the activation of peripheral blood leucocyte cultures. However, no differences were observed in the ability of the TNF-alpha-transfected, mock-transfected and wild-type mycobacteria to induce tumour cell killing activity. These results suggest that the immunomodulatory effects of M. smegmatis can be enhanced by transfection with vectors which allow the secretion of human TNF-alpha, thus increasing mycobacterial immunotherapeutic potential.

Potential value of urinary intercellular adhesion molecule-1 determination in patients with bladder cancer

OBJECTIVE

Intercellular adhesion molecule-1 (ICAM-1) is known to play a role in immunity against bladder cancer and can be detected in the supernatants of cultured bladder cancer cells that constitutively express ICAM-1. This study was performed to examine the relevance of the ICAM-1 urine test in patients with bladder cancer.

METHODS

A total of 53 patients with bladder carcinoma, 35 with history of bladder cancer, and 30 normal control subjects were included in this analysis. Urinary ICAM-1 (ulCAM-1) levels were measured by immunoassay and corrected for hydration status.

RESULTS

Levels of ulCAM-1 were significantly elevated in patients with bladder cancer or those at tumor-free status compared with normal control subjects (P=0.001). However, there was no apparent difference between the two groups of urothelial disorders (P >0.1). ulCAM-1 did not correlate with clinicopathologic variables of bladder cancer or patient outcome (P >0.1). Six patients at tumor-free status had multiple ulCAM-1 determinations during the study period. Three of these 6 patients had elevated ulCAM-1 levels and proved to have recurrent tumors; 3 of the 6 had stable ulCAM-1 levels and were still free of disease.

CONCLUSIONS

Our results suggest that urinary excretion of ICAM-1 is elevated in the early stage of bladder carcinogenesis, but is independent of biologic properties of bladder cancer. Serial monitoring of ulCAM-1 may be helpful in selecting patients who are at risk of tumor recurrence.

Detection and quantification of soluble intercellular adhesion molecule-1 (sICAM-1) in the serum and urine of patients with bladder cancer

BACKGROUND

A possible role for intercellular adhesion molecules in tumor progression and metastasis has been strongly suggested. To investigate the effect of soluble intercellular adhesion molecule-1 (sICAM-1) on bladder cancer, sICAM-1 serum and urinary concentrations were measured in patients with superficial or invasive bladder cancer and in patients with prostatic hypertrophy.

METHODS

Serum and urine samples were obtained from 26 patients with transitional cell carcinoma of the bladder (mean age, 66.8 years) and 14 patients with benign prostatic hypertrophy (BPH; mean age, 70.5 years). Fifteen healthy volunteers served as control patients. Samples were collected before surgery and 5 days after surgery. The serum and urinary slCAM-1 levels were measured by an ELISA.

RESULTS

The preoperative serum concentration of sICAM-1 was significantly higher in patients with invasive bladder cancer (351.8+/-158.0 ng/mL) than in the healthy controls (233.1+/-96.1 ng/mL; P< 0.05) or BPH patients (224.7+/-80.5 ng/mL; P< 0.05). In addition, serum sICAM-1 levels were significantly higher in patients with tumors greater than 3 cm in size (412.7+/-147.6 ng/mL) than in patients with smaller tumors (246.6+/-101.2 ng/mL; P<0.05). Urinary sICAM-1 levels in patients with invasive bladder cancer were also significantly higher than in the patients with superficial cancer prior to surgery.

CONCLUSION

Our results suggested that sICAM-1 may play an important role in the progression of bladder cancer, and that elevated serum sICAM-1 levels may be related to tumor size.

Retroviral transduction of intercellular adhesion molecule-1 enhances endothelial attachment of bladder cancer

An intercellular adhesion molecule-1 (ICAM-1)-negative RT4 transitional cell carcinoma (TCC) cell line was transduced with full-length ICAM-1 cDNA via a retroviral vector. Flow cytometry showed that a sense-oriented clone (S20) highly expressed ICAM-1 while an anti-sense clone (AS6) did not. Both S20 and AS6 bound with equal frequency (30 +/- 8.7% vs 30 +/- 9.4%) to unstimulated human umbilical vein endothelial cells (HUVECs) in cell attachment assays. However, when phorbol myristate acetate (PMA)-activated T lymphocytes, which express lymphocyte function-associated antigen-1 (LFA-1), were cocultured with tumor cells, attachment of S20 increased twofold (60 +/- 11.9%) but AS6 showed no change (32 +/- 11%). Blocking studies with anti-LFA-1 and anti-ICAM-1 monoclonal antibodies caused an inhibition of the attachment to baseline levels, demonstrating that the enhancement of S20 attachment was dependent upon the LFA-1/ICAM-1 interaction. Enhanced attachment of S20 was not inhibited by the addition of isotypic immunoglobulin G. These results suggest that LFA-1-expressing leukocytes may act as a bridge between the endothelium and tumor cells which express ICAM-1 and, thereby, enhance the potential for hematogenous metastasis.

Immunohistochemical analysis of intercellular adhesion molecule-1 expression in human gastric adenoma and adenocarcinoma

In this study, we examined the distribution of intercellular adhesion molecule-1 (ICAM-1) in gastric adenomas and carcinomas immunohistochemically at the light and electron microscopic levels. ICAM-1 was expressed on tumour cells in 12 of 28 gastric carcinomas and in 3 of 11 adenomas but not on most normal gastric epithelial cells. ICAM-1 was localized on luminal sites of neoplastic glands in adenomas and in intestinal-type carcinomas, and rarely on the surface of tumour cells of diffuse carcinomas. Expression of ICAM-1 on the tumour cells was more frequent in intestinal-type than diffuse carcinomas (P < 0.005). At the ultrastructural level, ICAM-1 was present prominently on the apical membrane and weakly on the lateral surface of the tumour cells of the intestinal-type carcinoma and also localized on the perinuclear membrane and the membrane of the endoplasmic reticulum of cancer cells. There was no significant association between ICAM-1 expression and HLA antigen expression or the number of infiltrating lymphocyte subsets. These results may implicate the synthesis of ICAM-1 by gastric cancer cells, but the expression is infrequent and may not be sufficient for host immune surveillance of the tumour cell.

Molecular regulation of intercellular adhesion molecule 1 (ICAM-1) expression in renal cell carcinoma

Intercellular adhesion molecule-1 (ICAM-1) mediates two important functional aspects of tumor biology, namely enhancement of tumor metastasis and mediation of host defense mechanisms such as lymphocyte-mediated tumor cytotoxicity. Since ICAM-1 is expressed by most renal cell carcinomas (RCC), the regulation of ICAM-1 expression is important in understanding the biological behavior of RCC. We report an investigation on ICAM-1 expression and molecular regulation by cytokines and protein kinase C activator on RCC cell lines. Of the various cytokines, tumor necrosis factor alpha (TNF alpha), interferon-gamma (IFN gamma), and phorbol myristate acetate (PMA) strongly upregulated ICAM-1 protein expression on RCC. The kinetics of ICAM-1 message induction was studied by Northern analysis of total RNA extracted from RCC and normal kidney proximal tubular (NKPT) cells. Time course studies showed that ICAM-1 mRNA was upregulated by INF gamma, TNF alpha, and PMA, plateaued after 2 h, and remained increased for up to 24 h. Although ICAM-1 mRNA in NKPT cells was upregulated by these cytokines, their messages returned to basal levels after 24 h. ICAM-1 mRNA stability assays showed that both unstimulated and stimulated RCC cells had very stable ICAM-1 mRNA up to 24 h. In order to investigate whether increased gene transcription contributes to ICAM-1 upregulation, RCC cells were treated with TNF alpha, IFN gamma, or PMA with or without simultaneous addition of actinomycin D. ICAM-1 message induction-blocking studies suggested that primary upregulation of ICAM-1 mRNA may be caused by transcriptional upregulation. These results suggest that long-lasting ICAM-1 message upregulation in response to cytokines or PMA may be due to transcriptional upregulation in the early phase and stabilization of ICAM-1 message in the later phase (after 4 h). These observations suggest that RCC may lack the normal downregulatory mechanisms which control ICAM-1 expression and may explain the high frequency of ICAM-1 expression observed on primary human RCC.

Effect of cell density on the expression of adhesion molecules and modulation by cytokines

Little is known about the regulation of integrin expression. Using flow cytometry, we have characterized the expression of integrin subunits and other adhesion molecules in bladder and colonic cell lines and studied their modulation by the cytokines tumor necrosis factor-alpha (TNF-alpha) and interferon-gamma (IFN-gamma). We show that although TNF-alpha and IFN-gamma may modulate integrin expression, these effects are, in the case of some integrin subunits, secondary to cytokine-induced changes in cell density. Cell density-dependent changes in the expression of alpha 2-, alpha 3-, alpha 6-, beta 1-, and beta 4-integrin subunits were seen. IFN-gamma produced density-independent decreases in expression of alpha 2- and beta 1-integrins and increases in expression of intercellular adhesion molecule-1 (ICAM-1), alpha 3-, alpha 6-, and beta 4-integrins. TNF-alpha produced increases in beta 1-integrin and ICAM-1 expression which were also density-independent. The expression of some integrin subunits is clearly density-dependent and the alterations seen are dependent on the cell line studied. This study illustrates the importance of including appropriate density-related controls in all investigations examining adhesion molecule expression.

Changes in urinary cytokines and soluble intercellular adhesion molecule-1 (ICAM-1) in bladder cancer patients after bacillus Calmette-Guérin (BCG) immunotherapy

Intravesical immunotherapy for carcinoma in situ of the bladder is arguably the most effective form of tumour immunotherapy described to date. Following repeated instillations of BCG organisms into the bladder, large quantities of cytokines are detected in patients' urine. This study concerns the production of IL-1 beta, IL-2, IL-4, IL-6, IL-8, IL-10, tumour necrosis factor-alpha (TNF-alpha), interferon-gamma (IFN-gamma) and soluble ICAM-1 (sICAM-1) throughout the six weekly instillations which comprise a therapeutic course. Sequential instillations of BCG induced secretion of IL-1 beta, IL-2, IL-6, IL-8, IL-10, TNF-alpha, IFN-gamma and sICAM-1 into urine. The responses were heterogeneous between patients and cytokines, but some general trends were evident. Although cytokine levels were initially low, their concentration increased with repeated instillation of BCG. Certain cytokines (e.g. IL-6, IL-8 and IL-10) could be detected after the first instillation, whilst others (e.g. IL-2 and IFN-gamma) were not detected until after the third or fourth instillation. Interestingly, IL-4 was not detected, perhaps suggesting a differential effect on Th2-like responses. Some patients produced particularly elevated or non-detectable levels of cytokines, and a positive correlation was found between the production of various cytokines. The production of a particular cytokine did not correspond with lack of production of another species. Whether monitoring the production of cytokines following therapy may be of prognostic value will be determined in a larger series of patients. However, as these potent immunomodulators are thought to be important for the 75% complete clinical response observed with BCG therapy, there remains the possibility that detection of the products of an activated immune system may correlate with eventual clinical outcome. This study is a necessary forerunner to full prognostic evaluation of such immunological data.

Production of urinary tumour necrosis factors and soluble tumour necrosis factor receptors in bladder cancer patients after bacillus Calmette-Guérin immunotherapy

Intravesical immunotherapy for bladder cancer is the most effective form of tumour immunotherapy. Following repeated instillations of bacillus Calmette-Guérin (BCG) organisms into the bladder large quantities of several cytokines are detected in the urine. These cytokines include interleukins IL-1 beta, IL-2, IL-4, IL-6, IL-8, IL-10, tumour necrosis factor alpha (TNF alpha), interferon gamma (IFN gamma) and also soluble intercellular adhesion molecule ICAM-1. In the work reported here we simultaneously quantified urinary levels of TNF alpha, TNF beta, TNF receptor I and TNF receptor II by enzyme-linked immunosorbent assay (ELISA) techniques and compared this with bioactive levels of TNF. This was undertaken with a limited number of patients throughout a course of six instillations of immunotherapy. Sequential instillations of BCG induced secretion of TNF alpha and TNF beta into urine. These cytokines were not always secreted simultaneously, perhaps suggesting differential regulation of their synthesis. Maximal concentrations of TNF alpha were 675 pg/ml and TNF beta 47 pg/ml. High levels of both species of soluble TNF receptor were readily identified in urine. Maximal levels of sTNF-RI were 6200 pg/ml (range from 0) and for sTNF-RII 7800 pg/ml (range from 0). Contrasting with earlier published observations concerning cytokine levels, the concentration of soluble receptor did not increase with repeated instillation. In apparent contrast with the ELISA data, very low levels of bioactive TNF were identified by the L929 bioassay (maximum concentration 1 U/ml) despite the elevated concentration of immunoreactive TNF. The large concentrations of soluble TNF receptor in patients' urine samples could account for the apparently low bioactivity as determined by the L929 cytotoxicity assay. The precise nature of the role of TNF in BCG immunotherapy remains undetermined; however, it is thought that proinflammatory cytokines are in part responsible for the clinical efficacy of this therapeutic approach. Whether other cytokines are antogonised by soluble binding proteins remains to be determined. Furthermore, whether TNF is bioactive in the bladder wall and only neutralised in the urine also requires investigation.

Reinforced cytotoxicity of lymphokine-activated killer cells toward glioma cells by transfection of the killer cells with the gamma-interferon gene

Lymphokine-activated killer (LAK) cells generated from peripheral blood lymphocytes incubated with recombinant interleukin-2 were transfected with the human gamma-interferon (HuIFN-gamma) gene by means of liposomes having a positive charge on their surface. The cells secreted significant amounts of HuIFN-gamma (reaching more than 5 U/ml) into the culture medium. The HuIFN-gamma produced by the cells induced intercellular adhesion molecule-1 (ICAM-1) and enhanced the expression of Fas antigen on the surface of human glioma cells. Also, LAK cells transfected with HuIFN-gamma gene exhibited reinforcement of cytotoxicity toward human glioma cell lines (U251-MG and SK-MG-1). Furthermore, the reinforcement was significantly quenched by anti-ICAM-1 and/or anti-TNF-alpha monoclonal antibody.