Interleukin-2 gene transfer into human transitional cell carcinoma of the urinary bladder

The differential immunological activities of Ganoderma lucidum on human pre-cancerous uroepithelial cells

AIMS OF THE STUDY

Ganoderma lucidum is active to stimulate immunological effector cells, but the effects on uroepithelial cells have never been explored. The present study compared the expression of major cytokines induced by the water (GLw) and ethanol (GLe) extracts of G. lucidum.

MATERIALS AND METHODS

The pre-cancerous human uroepithelial cell (HUC-PC) line was employed. A total of 15 cytokines, including major Th1/Th2 cytokines and chemokines, were measured in the complete media after 24h incubation with GLw and GLe. Additionally, the following assays were performed: cytotoxicity, apoptosis, migration of neutrophils, and nuclear factor-kappaB (NF-κB) DNA binding activity.

RESULTS

GLe inhibited the growth of HUC-PC cells through apoptosis. Interleukins IL-2, IL-6, and IL-8 were significantly up-regulated by GLe in dose-dependent manners, but not by GLw. However, MCP-1 level was significantly increased by GLw but was oppositely reduced by GLe. Furthermore, the elevation of cytokine expression was correlated with the enhancement of p50/p65 NF-κB activity induced by GLe. The elevated IL-8 levels in GLe-treated cells were also correlated with the migration of neutrophils.

CONCLUSIONS

GLe and GLw exhibited different immunological activities on the HUC-PC cells. In particular, the activities of GLe may favor the clearance of high risk urothelial cells, suggesting potent chemopreventive ingredients are extractable by ethanol from G. lucidum.

In Vivo Retroviral Mediated Gene Transfer into Bladder Urothelium Results in Preferential Transduction of Tumoral Cells

OBJECTIVES

Superficial bladder tumours are at high risk for recurrence, relapse after resection, escape to intravesical immunotherapy and they may become invasive. New therapeutics are therefore needed to achieve cure. Thus, gene therapy is an attractive new treatment modality for malignant bladder tumours. The purpose of this study was to evaluate the feasibility and the efficiency of retroviral mediated reporter gene transfer into malignant urothelial cells both in vitro and in vivo.

METHODS

We evaluated the feasibility of the transfection of bladder tumour with direct intravesical instillation of a defective retrovirus. The vector was derived from LXSN. The efficiency of transduction with the Moloney Leukaemia Murine virus-based vector, amphotrophic retroviral vector, was monitored through the expression of two marker genes (nls-LacZ and NeoR). The canine animal was chosen since it can present with spontaneous bladder carcinomas mimicking human pathology. Primary cultures of two normal canine bladder urothelium and two canine primary bladder tumours were first studied. We then investigated in vivo, in two normal and two spontaneous tumour bearing dogs, the transduction of urothelial cells following direct intravesical instillation of 2.10(4) to 3.10(6) of the retroviral vector.

RESULTS

Transduced cells were evidenced in all primary cultures of canine normal urothelium and transitional cell carcinoma. Bladder biopsies from sound dogs instilled with the viral solution showed long lasting transduction up to 60 days long. Bladder cryosections from tumour-bearing dogs displayed transduction of superficial layers of urothelial cancer cells without passing through lamina propria. In vivo transduction was evidenced in 1 to 15% (mean 5%) of the cells in the tumours and preferentially addressed malignant cells. Normal epithelium either originating from sound or tumour-bearing animals was not transduced.

CONCLUSION

These results demonstrate for the first time the feasibility of in vivo retroviral transduction of bladder cancer using a clinically relevant procedure.

The universal dynamics of tumor growth

Scaling techniques were used to analyze the fractal nature of colonies of 15 cell lines growing in vitro as well as of 16 types of tumor developing in vivo. All cell colonies were found to exhibit exactly the same growth dynamics-which correspond to the molecular beam epitaxy (MBE) universality class. MBE dynamics are characterized by 1), a linear growth rate, 2), the constraint of cell proliferation to the colony/tumor border, and 3), surface diffusion of cells at the growing edge. These characteristics were experimentally verified in the studied colonies. That these should show MBE dynamics is in strong contrast with the currently established concept of tumor growth: the kinetics of this type of proliferation rules out exponential or Gompertzian growth. Rather, a clear linear growth regime is followed. The importance of new cell movements-cell diffusion at the tumor border-lies in the fact that tumor growth must be conceived as a competition for space between the tumor and the host, and not for nutrients or other factors. Strong experimental evidence is presented for 16 types of tumor, the growth of which cell surface diffusion may be the main mechanism responsible in vivo. These results explain most of the clinical and biological features of colonies and tumors, offer new theoretical frameworks, and challenge the wisdom of some current clinical strategies.

Adenovirus mediated gelsolin gene therapy for orthotopic human bladder cancer in nude mice

PURPOSE

Gelsolin is an actin regulatory protein that is undetectable or reduced in human bladder tumors compared with normal epithelial cells. Whether the over expression of gelsolin could inhibit tumor growth was investigated in an orthotopic bladder cancer nude mouse model using recombinant adenovirus encoding wild-type gelsolin (Ad-GSN).

MATERIALS AND METHODS

The 2 human bladder cancer cell lines KU-7 and UMUC-2 were transduced with Ad-GSN in vitro. Flow cytometric analysis was done to examine the cell cycle after transducing the adenovirus. Cell growth was compared with control groups of these cells transduced with adenovirus containing the Escherichia coli beta-galactosidase gene Ad-betagal. In vivo KU-7 cells were introduced into the bladder of nude mice (day 0), followed by 3 injections into the urethra (days 2 to 4) with Ad-GSN or Ad-betagal (1 x 10 pfu). At 8 days after initial adenovirus exposure (day 10) each bladder was sectioned and stained, and the mass of the tumor was digitally determined.

RESULTS

Bladder cancer cell growth (KU-7 and UMUC-2) was inhibited after these cells were transduced with Ad-GSN in vitro. Based on flow cytometric analysis over expression of gelsolin may cause these cells to arrest or delay at the G2/M phase of the cell cycle. In the orthotopic bladder cancer model the mass of the tumor was approximately 90% less in Ad-GSN treated animals than in controls.

CONCLUSIONS

Ad-GSN provides a significant tumor suppressive effect on human bladder cancer cells in this orthotopic nude mouse model. Adenovirus mediated over expression of gelsolin may be useful therapy for human bladder cancer.

Immunotherapy of urologic tumors: principles and progress

Immunotherapy is receiving interest as an alternative or adjuvant approach to the treatment of many malignancies. The potential for immune modulation as a treatment of solid tumors is the focus of cancer researchers throughout the world. Though not a novel idea, increasing technological sophistication and continued advancement in the understanding of the immune system have increased the number of novel therapeutic approaches. In urology, BCG is an excellent example of how modulation of the immune system can be used to treat malignancy, and we are only now beginning to understand its immune mechanisms. Numerous other immunotherapeutic approaches have been and are being developed and evaluated. We provide a brief overview of immunology and its relation to tumor development and growth, and focus on some of the immunotherapeutic approaches to renal cell carcinoma, prostate adenocarcinoma, and transitional cell carcinoma of the bladder.

Immune gene therapy in urology

Effective treatments are needed urgently for metastatic disease in bladder, prostate, and renal cell cancer. In the past few years, several new approaches for treating these conditions have been proposed, including gene therapy. A number of different strategies have been developed to accomplish urologic cancer gene therapy. Genetic immunomodulation strategies attempt to activate immune defense mechanisms against tumor cells by transfer of tumor antigens, cytokine genes, or strongly immunogenic cell surface molecules. In this review, we illustrate the recent developments in immune gene therapy.