Biomedical subjects

Nicholas P Munro

Publications and source records attributed to Nicholas P Munro.

3 recordsLinked to original sources

PubMed2006

Urinary biomarker profiling in transitional cell carcinoma.

Urinary biomarkers or profiles that allow noninvasive detection of recurrent transitional cell carcinoma (TCC) of the bladder are urgently needed. We obtained duplicate proteomic (SELDI) profiles from 227 subjects (118 TCC, 77 healthy controls and 32 controls with benign urological conditions) and used linear mixed effects models to identify peaks that are differentially expressed between TCC and controls and within TCC subgroups. A Random Forest classifier was trained on 130 profiles to develop an algorithm to predict the presence of TCC in a randomly selected initial test set (n = 54) and an independent validation set (n = 43) several months later. Twenty two peaks were differentially expressed between all TCC and controls (p < 10(-7)). However potential confounding effects of age, sex and analytical run were identified. In an age-matched sub-set, 23 peaks were differentially expressed between TCC and combined benign and healthy controls at the 0.005 significance level. Using the Random Forest classifier, TCC was predicted with 71.7% sensitivity and 62.5% specificity in the initial set and with 78.3% sensitivity and 65.0% specificity in the validation set after 6 months, compared with controls. Several peaks of importance were also identified in the linear mixed effects model. We conclude that SELDI profiling of urine samples can identify patients with TCC with comparable sensitivities and specificities to current tumor marker tests. This is the first time that reproducibility has been demonstrated on an independent test set analyzed several months later. Identification of the relevant peaks may facilitate multiplex marker assay development for detection of recurrent disease.

Adult↗

PubMed2003

Proteomic profiling of urinary proteins in renal cancer by surface enhanced laser desorption ionization and neural-network analysis: identification of key issues affecting potential clinical utility.

Recent advances in proteomic profiling technologies, such as surface enhanced laser desorption ionization mass spectrometry, have allowed preliminary profiling and identification of tumor markers in biological fluids in several cancer types and establishment of clinically useful diagnostic computational models. There are currently no routinely used circulating tumor markers for renal cancer, which is often detected incidentally and is frequently advanced at the time of presentation with over half of patients having local or distant tumor spread. We have investigated the clinical utility of surface enhanced laser desorption ionization profiling of urine samples in conjunction with neural-network analysis to either detect renal cancer or to identify proteins of potential use as markers, using samples from a total of 218 individuals, and examined critical technical factors affecting the potential utility of this approach. Samples from patients before undergoing nephrectomy for clear cell renal cell carcinoma (RCC; n = 48), normal volunteers (n = 38), and outpatients attending with benign diseases of the urogenital tract (n = 20) were used to successfully train neural-network models based on either presence/absence of peaks or peak intensity values, resulting in sensitivity and specificity values of 98.3-100%. Using an initial "blind" group of samples from 12 patients with RCC, 11 healthy controls, and 9 patients with benign diseases to test the models, sensitivities and specificities of 81.8-83.3% were achieved. The robustness of the approach was subsequently evaluated with a group of 80 samples analyzed "blind" 10 months later, (36 patients with RCC, 31 healthy volunteers, and 13 patients with benign urological conditions). However, sensitivities and specificities declined markedly, ranging from 41.0% to 76.6%. Possible contributing factors including sample stability, changing laser performance, and chip variability were examined, which may be important for the long-term robustness of such approaches, and this study highlights the need for rigorous evaluation of such factors in future studies.

Adult↗

PubMed2003

Fibroblast growth factors and their receptors in transitional cell carcinoma.

PURPOSE: The recent identification in transitional cell carcinoma of mutations in a fibroblast growth factor (FGF) receptor, namely FGF receptor-3, has provoked great interest in the potential usefulness of FGF receptors and their ligands as molecular markers and as targets for bladder cancer therapy. We examined these possibilities in light of the published literature. MATERIALS AND METHODS: We reviewed the world literature on FGFs and their receptors from 1966 to January 2002 using PubMed. RESULTS: The recent identification in transitional cell carcinoma of a high frequency of mutations in FGF receptor-3 predicted to activate kinase activity of the receptor indicate a likely role as an oncogene in the urothelium. The finding of FGF receptor-3 mutations only rarely in other tumor types to date indicates surprising urothelial specificity that requires tissue specific approaches for evaluation and exploitation. In contrast, FGF receptor-2 expression is down-regulated in bladder tumors, suggesting a possible tumor suppressor role. Information is available on the expression of FGF receptors-1 and 2 in normal bladder and urine, and in bladder tumors. These angiogenic factors represent potential urine markers of bladder neoplasia, although as single markers they lack sufficient sensitivity and specificity. Some interesting insights into the potential role of these factors have come from studies using in vitro model systems. However, there is little information on the numerous other members of this family of growth factors in the bladder and, therefore, much scope for future studies. CONCLUSIONS: It is clear that the FGFs and their receptors have important roles in the development of transitional cell carcinoma. Undoubtedly it will be a focus for much future research. It can be anticipated that members of these protein families would represent useful clinical markers and potential targets for bladder cancer therapy.

Animals↗