The immunotherapy of prostate and bladder cancer

Detection of functional antigen-specific T cells from urine of non-muscle invasive bladder cancer patients

To gain further insights into the role of T lymphocytes in immune responses against bladder tumors, we developed a method that monitors the presence of functional antigen-specific T cells in the urine of non-muscle invasive bladder cancer patients. As relatively few immune cells can usually be recovered from urine, we examined different isolation/amplification protocols and took advantage of patients treated with weekly intravesical instillations of Bacillus Calmette-Guérin, resulting in large amounts of immune cells into urine. Our findings demonstrate that, upon in vitro amplification, antigen-specific T cells can be detected by an interferon γ (IFNγ)-specific ELISPOT assay.

Prostate Cancer Progression and Surrounding Microenvironment

Bidirectional cellular interactions between prostate cancer and prostate or bone stroma are needed for local tumor growth and distant metastasis. The genetics of cancer cells is affected by the host microenvironment and, reciprocally, permanent gene expression changes occur in the stroma surrounding epithelial cancer cells. The immune-mediated micromilieu also affects the progression of prostate cancer; the role of the immune system in controlling the growth of prostate cancer cells is complex, with immune escape mechanisms prevailing over effective antitumor response. Moreover, tumor stem cell models to explain the origin and progression of prostate cancer require appropriate environmental conditions. On the basis of a review of the literature, this article aims to outline the recent advances in the elucidation of the molecular mechanisms underlying the interactions between prostate cancer and its microenvironment.

Impact of NK Cell Count on Bladder Cancer Recurrence

Purpose

The aim of the present study was to evaluate the prognostic value of the local NK cell count in patients with recurrent non-muscle-invasive bladder cancer.

Methods

The archival paraffin-embedded primary tumor specimens were derived from retrospectively-selected patients, who were treated between 1996 and 2001 for bladder cancer. The study group consisted of 46 patients who developed recurrent disease during their first two post-operative years. The control group consisted of 27 patients who did not develop recurrent disease during their first two post-operative years. Specimens were assessed immunohistochemically with standard “ABC” technique. The frequency of NK cells was expressed as total number, estimated for each tumor by counting the positive NK cells in 10 high-power representative fields. Statistical analysis was done using Kruskal-Wallis test.

Results

Patients with recurrent non-muscle invasive bladder cancer in general have significantly higher values of stromal NK cell count than the control group. Patients with single tumor and smaller tumors show a statistically significant difference in NK cell count between study and control group. There also exists a statistically significant difference in stromal NK cell count in patients with clinical stage Ta tumor.

Conclusions

Our results confirm an association of the bladder wall NK cell count in bladder cancer patients with the natural history of disease. Further well-performed, reproducible, large, prospective investigation stratified by clinical parameters, such as tumor number and diameter, is needed to display the true value of this marker in the clinical work-up of bladder cancer patients.

Pretreatment parameters obtained from peripheral blood sample predicts invasiveness of bladder carcinoma

PURPOSE

To predict the invasiveness of urothelial bladder carcinoma using a logistic regression model on preoperative peripheral blood samples.

PATIENTS AND METHODS

Hospital data of patients operated for urothelial carcinoma were reviewed retrospectively. Preoperative blood samples were collected before the first cystoscopic examination. Any kind of infection or inflammation was an exclusion criterion. Patients were grouped as having a non-muscle-invasive or muscle-invasive urothelial carcinoma. The mean age was 69 years and was determined as the cut-off value. According to receiver operating characteristic curves, threshold points were determined for lymphocytes, neutrophil count, neutrophil-to-lymphocyte ratio (NLR), thrombocytes and mean platelet volume. Demographic specialties, parameters obtained from blood samples, tumor size and multiplicity were evaluated and significant parameters were put into a logistic regression model.

RESULTS

The study group consisted of 80 non-muscle-invasive and 102 muscle-invasive patients. Age (≤69 vs. >69), female gender, NLR (2.57), mean platelet volume (7.9/fl) and platelet count (400,000/µl) were significant parameters and put in a model. Using odds ratios, the probability of tumor invasiveness was calculated by a formula.

CONCLUSION

Age, female gender, NLR and platelet count were found to be the predictors of invasiveness of urothelial carcinoma.

Dysfunction of natural killer cells in patients with transitional cell carcinoma

Previous studies had established that transforming growth factor-beta1 (TGF-beta1) is highly expressed in bladder tumor, facilitating progression and spreading of the cancerous cells. Here, we report that both the number and the cytotoxic function of natural killer (NK) cells are decreased in patients with superficial transitional cell carcinoma (TCC). In consistent with previously reported findings, the plasma TGF-beta1 concentration is also elevated in patients with superficial TCC. In vitro, the cytotoxic function of NK cells was impaired by the presence of TGF-beta1. Hence, our data suggested elevated concentration of serum TGF-beta1 in loss of NK cytotoxicity in superficial TCC patients, implicating altered innate immunity may correlate with the incidence of TCC.

Cell based cancer vaccines: regulatory and commercial development

There is both clinical and regulatory drive to expedite development of safe, efficacious cancer therapies. Stimulation of the patients immune system through vaccination with tumour cells has long been at the vanguard of cancer therapeutic vaccines, and several have been demonstrated to be safe and to have efficacy in early clinical trials for a range of cancers including melanoma, renal cell carcinoma, prostate and colorectal cancers. A number of development-stage vaccines and strategies are currently being tested, utilising either autologous or allogeneic tumour cells, which may also have been ex vivo manipulated (e.g. cytokine transfected cells). It seems likely that clinical trial success, and hence patient benefit, could be improved through better patient identification, possibly by the discovery and use of novel immune response biomarkers. In this review, we aim to summarise the state of tumour cell vaccines in commercial development and to explore not only the difficulties of determining efficacy, but also the production challenges faced when developing a vaccine from proof of principle to pivotal phase III trials.

Human bladder carcinoma is dominated by T-regulatory cells and Th1 inhibitory cytokines

PURPOSE

Immunotherapy has faced limited success, although many solutions have been proposed. Recently regulatory T cells have made a comeback in the immunological arena and the role of these cells in patients with cancer is in focus. It is under evaluation whether the immunological status of patients with cancer may affect their sensitivity to immunotherapy. We are developing immunostimulating gene therapy for treating bladder cancer. In this study we constructed an immunological profile of patients with bladder carcinoma to understand which obstacles must be circumvented.

MATERIALS AND METHODS

Biopsies and blood were used to identify immune cell populations by FACS(R), histochemistry and proliferation assays, and cytokine production by polymerase chain reaction.

RESULTS

Results indicate that bladder carcinoma is a Tr1 dominated tumor, as shown by the infiltration of T-regulatory cells expressing FOXP3, and the presence of tumor necrosis factor-beta and interleukin-10 mRNA copies. We further noted that circulating patient T cells were unresponsive to polyclonal T-cell activation compared to healthy donor cells. Moreover, CD4+CD25+ T cells were increased in patient blood and could suppress the expansion of allogeneic T cells from healthy donors.

CONCLUSIONS

Patients with bladder carcinoma show an immunosuppressive regulatory profile, including nonresponsive T cells. Clinical protocols able to effectively counteract these mechanisms are warranted.

Management of the Spectrum of Hormone Refractory Prostate Cancer

INTRODUCTION

In its advanced stages, hormone refractory prostate cancer (HRPC) is an incurable condition which consists of a spectrum of disease. This requires an integrated multidisciplinary approach by an uro-oncologic team supported by radiologists, skeletal surgeons and palliative care. Aim of this review was to critically evaluate the current and potential approaches to patients affected by HRPC.

MATERIALS AND METHODS

A comprehensive evaluation of available published data included analysis of published full-length papers that were identified with Medline and Cancerlit from January 1981 to January 2006. Official proceedings of internationally known scientific societies held in the same time period were also assessed.

RESULTS

Most men with hormone refractory prostate cancer will die of their disease in the absence of intercurrent illness, and the various conditions arising as a consequence of local and distal cancer progression commonly lead to a spectrum of morbidity requiring treatment. Recent data regarding docetaxel-based chemotherapy have shown small but significant improvements in survival and improvement in quality of life in men receiving treatment. However, this therapy may not be suitable for all patients. New agents used alone or in combination with docetaxel currently are under trial in an attempt to provide much needed improvements in outcome. Bone-targeted treatments, particularly late-generation bisphosphonates, have added to the range of options, reducing the incidence of skeletal complications in some men. Further work is needed to target their use more effectively, to explore their efficacy in combination with existing proven therapies and to develop new approaches to treat bone metastases. Complications arising as a consequence of upper and lower tract dysfunction, haematologic, neurologic and psychologic disorders are common. These complications often are amenable to effective treatment, but interventions may engender difficult clinical and ethical decisions.

CONCLUSIONS

Although HRPC is incurable, it is not untreatable, and that the clinical management embraces not just chemotherapy, but many interventional and supportive therapies. A holistic and supportive approach to patient care is vital for optimal management, and is best provided by a coordinated, multidisciplinary team including urologists and oncologists.

Cancer vaccines as a therapeutic modality: The long trek

The development of cancer vaccines has been one of the several false dawns in which initial promising Phase I and Phase II clinical data have not been followed up with conclusive Phase III trials. In this review, we describe some of the successes and failures, and review the most likely reasons for Phase III failure, such as protocol changes, which are common between Phase II and III, and poorly defined patient groups. Nevertheless, significant survival results have been reported with autologous vaccines for colorectal, renal and, more recently, prostate cancer. In addition, it is becoming evident that immunotherapy is potentially synergistic with other treatment modalities, such as chemotherapy, which can reduce T-regulatory activity that inhibits the immune response to cancer vaccines. This potential for synergy should allow cancer vaccines to become part of the standard treatment regimen for many common tumours.

Very long chain fatty acid beta-oxidation by rat liver mitochondria and peroxisomes

Crude mitochondrial fractions were isolated by differential centrifugation of rat liver homogenates. Subfractionation of these fractions on self-generating continuous Percoll gradients resulted in clearcut separation of peroxisomes from mitochondria. Hexacosanoic acid beta-oxidation was present mainly in peroxisomal fractions whereas hexacosanoyl CoA oxidation was present in the mitochondrial as well as in the peroxisomal fractions. The presence of much greater hexacosanoyl CoA synthetase activity in the purified preparations of microsomes and peroxisomes compared to mitochondria, suggests that the synthesis of coenzyme A derivatives of very long chain fatty acids (VLCFA) is limited in mitochondria. We postulate that a specific VLCFA CoA synthetase may be required to effectively convert VLCFA to VLCFA CoA in the cell. This specific synthetase activity is absent from the mitochondrial membrane, but present in the peroxisomal and the microsomal membranes. We postulate that substrate specificity and the subcellular localization of the specific VLCFA CoA synthetase directs and regulates VLCFA oxidation in the cell.