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Richard J Cote

Publications and source records attributed to Richard J Cote.

8 recordsLinked to original sources
PubMed2003

Therapeutic approaches to bladder cancer: identifying targets and mechanisms.

Transitional cell carcinoma is the second most common genitourinary malignancy in US and third most common cause of death among genitourinary tumors. Treatment options for bladder cancer include surgery, often combined with chemotherapy, radiation, and/or immunotherapy. The MVAC adjuvant chemotherapy regimen has been most widely used in locally invasive as well as metastatic disease. Only a proportion of patients at risk will respond to therapy. There is thus need to identify good responder patients for adjuvant therapy and to identify new targets to treat a greater range of patients. Based upon patient-specific aberrations in pathways or known markers, both existing and new therapies can be tailored to benefit patients based on the risk of progression and molecular alterations specific to a patient's tumor. Targeted therapy, therefore, is defined as therapy that targets mechanism and risk. Utilizing the available knowledge of the molecular biology of cell-cycle regulation, signal transduction, apoptosis, and angiogenesis in bladder cancer, we review the potential therapeutic targets for rational drug development. Finally, using bladder cancer as a model for translational research, requirements for a desired clinical trial are presented.

Animals↗
PubMed2002

Thrombospondin-1 expression in patients with pathologic stage T3 prostate cancer undergoing radical prostatectomy: association with p53 alterations, tumor angiogenesis, and tumor progression.

OBJECTIVES: To investigate thrombospondin-1 (TSP) expression in patients with prostate cancer undergoing radical prostatectomy. TSP is a p53-dependent inhibitor of tumor angiogenesis. Previous studies have demonstrated that TSP expression is significantly associated with the microvessel density (MVD) count, p53 expression, and disease-specific and overall survival in patients with invasive bladder cancer undergoing radical cystectomy. METHODS: Radical prostatectomy specimens from 85 patients with pathologic Stage T3 disease were analyzed for TSP expression, p53 nuclear reactivity, and MVD using antigen-retrieval immunohistochemistry. The median follow-up after surgery was 10.6 years (range 1.8 to 15.4). Disease recurrence was defined as a prostate-specific antigen level of 0.2 ng/mL or greater on two consecutive occasions after surgery. TSP expression was graded as present or absent on the basis of the immunoreactivity in the extracellular matrix by persons unaware of the clinical outcome. Specimens were considered p53 positive (altered) if more than 10% of the tumor cells demonstrated nuclear reactivity. The chi-square test was used to determine whether the associations were significant between the pathologic tumor characteristics and the immunohistochemical findings. The log-rank test was used to determine the associations between the immunohistochemical findings and disease recurrence. RESULTS: TSP and p53 were graded as positive in 21 (26%) and 16 (19%) tumors, respectively. The median MVD count was 111.5. No significant associations were found among p53 status, TSP expression, and MVD. Seminal vesicle invasion and Gleason pattern 4 or 5 disease were significant predictors of disease recurrence. A trend was noted toward a higher rate of disease recurrence for patients with altered p53 expression (p53 positive) or increased MVD. TSP expression was not associated with disease recurrence. CONCLUSIONS: We found no significant association between TSP expression and p53 status, MVD count, or outcome after radical prostatectomy for patients with pathologic Stage T3 prostate cancer. Our data suggest that p53 and MVD may be associated with outcome in these patients. Additional studies are needed to identify reliable molecular markers of outcome for patients with this disease.

Adenocarcinoma↗
PubMed2002

A modified reduced-temperature antigen retrieval protocol effective for use with a polyclonal antibody to cyclooxygenase-2 (PG 27).

Antigen retrieval is now a standard procedure in immunohistochemical studies of tissues for diagnosis and research. While the most commonly used protocol (20 minutes at 100 degrees C in citrate buffer pH 6.0) is effective for many antibody/antigen combinations, experience has shown that in some instances, this standard approach fails. Under these circumstances, a successful antigen retrieval protocol may still be established by varying key conditions in the antigen retrieval process. The authors previously have advocated a test battery approach to determine the optimal conditions for antigen retrieval, illustrated here with respect to a polyclonal antibody to cyclooxygenase-2 (PG-27) that failed to give a positive staining result after orthodox antigen retrieval. The key feature of this modified antigen retrieval protocol is heating the deparaffinized tissue sections at a reduced temperature (90 degrees C as opposed to 100 degrees C). For this particular antibody, a boiling condition yields a negative result, a principal reason why previous investigators have used a tyramide signal amplification system to achieve satisfactory immunohistochemical results with this antibody. The optimal antigen retrieval protocol established in the authors' laboratory for this polyclonal antibody to cyclooxygenase-2 (PG-27) was evaluated in a study of formalin-fixed, paraffin-embedded cell lines and 31 bladder cancer tissue blocks using the tissue microarray technique, with side-by-side comparison between the results obtained by a tyramide signal amplification method (without antigen retrieval) and a standard immunohistochemical method with the optimized antigen retrieval protocol. The reduced temperature antigen retrieval protocol yielded a comparable or superior immunostaining for cyclooxygenase-2 both in cell lines and tissue blocks. In conclusion, use of the test battery approach allowed development of a modified antigen retrieval technique that provides a more reliable, much simpler approach for the demonstration of cyclooxygenase-2 in archival tissues.

Antibodies↗
PubMed2002

DNA extraction from archival formalin-fixed, paraffin-embedded tissue sections based on the antigen retrieval principle: heating under the influence of pH.

During the course of diagnostic surgical pathology, pathologists have established a large collection of formalin-fixed, paraffin-embedded tissues that form invaluable resources for translational studies of cancer and a variety of other diseases. Accessibility of macromolecules in the fixed tissue specimens is a critical issue as exemplified by heat-induced antigen retrieval (AR) immunohistochemical (IHC) staining. On the basis of observations that heating may also enhance in situ hybridization (ISH) and the similarity of formalin-induced chemical modifications that occur in protein and in DNA, we designed a study to examine the efficiency of DNA extraction from archival formalin-fixed, paraffin-embedded tissues using an adaptation of the basic principles of the AR technique, i.e., heating the tissue under the influence of different pH values. Archival paraffin blocks of lymph nodes, tonsil, and colon were randomly selected. Each paraffin block was prepared in 34 microtubes. For each paraffin block, one tube was used as a control sample, using a non-heating DNA extraction protocol. The other 33 tubes were tested using a heating protocol under 11 variable pH values (pH 2 to 12) under three different heating conditions (80, 100, and 120C). Evaluation of the results of DNA extraction was carried out by measuring yields by photometry and PCR amplification, as well as kinetic thermocycling (KTC)-PCR methods. In general, lower pH (acid) solutions gave inferior results to solutions at higher pH (alkaline). Heating tissues at a higher temperature and at pH 6-9 gave higher yields of DNA. There appeared to be a peak in terms of highest efficiency of extracted DNA at around pH 9. The average ratios 260:280 of extracted DNA also showed better values for samples heated at 120C. PCR products of three primers showed satisfactory results for DNA extracted from archival paraffin-embedded tissues by heating protocols at pH 6-12, with results that were comparable to the control sample subjected to the standard non-heating, enzymatic DNA extraction method. This study is the first to document the use of heating at an alkaline pH for DNA extraction from archival formalin-fixed, paraffin-embedded tissues, a recommendation based on the principles of AR for protein IHC. These findings may lead to a more effective protocol for DNA extraction from archival paraffin-embedded tissues and may also provide enhanced understanding of changes that occur during formalin-induced modification of nucleic acids.

Antigens↗
PubMed2002

Role of genetic and expression profiling in pharmacogenomics: the changing face of patient management.

As the determination of gene sequences and their function gains speed at the dawn of the third millennium, biomedical research efforts are oriented towards definition of the genetic and molecular expression patterns that may drive different disease. A major part of these efforts is addressed to the definition of inter-individual variations that are expected to become integral for treatment planning, in terms of efficacy and adverse effects of drugs. It is this thrust on genome-based 'rational therapeutics' that is hoped to progressively lead to the era of 'personalized medicine'. This approach uses the technological expertise from genomics and functional genomics to define, predict and monitor the nature of the response of an individual to drugs, and to rationally design newer drugs. In the present review we will conduct our readers through an understanding of the fundamentals of pharmacogenomics and of the technologies currently available that are advancing this relatively new science. Conversely, there are issues raised that concern how medical practice is preparing itself to implement new alternatives for therapeutical interventions and finally, how to respect patient confidentiality and rights.

Antimetabolites, Antineoplastic↗