Fibroblast growth factor 21 (FGF21) in children and adolescents with chronic kidney disease.

Fibroblast growth factor 21 (FGF21) is one of the members of endocrine arm of FGF family. Its actions as a glucose and lipids metabolism regulator are widely known. Although the mechanism of FGF21 action in kidneys is still under investigation, FGF21 was considered as a marker of early kidney function decline. While many researchers focused on adult subjects in this matter, there are no data regarding children. Therefore, we have investigated the relationship between plasma or urine FGF21 levels and kidney function in a group of 42 pediatric patients with chronic kidney disease (CKD). Anthropometrical parameters and blood pressure were taken, routine biochemical tests were performed. The concentration of FGF21 in serum and urine was determined by enzyme immunoassay. The results revealed significantly higher serum FGF21 concentration among children from CKD group. However, serum FGF21 level was not related to gender, proteinuria, eGFR or renal replacement therapy. Urine FGF21 concentration correlated negatively with albuminuria and positively with eGFR. Documented negative correlation of FGF21 fractional excretion and eGFR is not enough to support the role of FGF21 as a biomarker for predicting kidney disease progression in children and adolescents. Other mechanisms including local kidney FGF21 production or enhanced excretion due to higher extrarenal production may result in higher urine FGF21 concentrations.

Early renal dysfunction and fibroblast growth factor-23 in patients with small vessel disease-related stroke.

Interactions between cerebral small vessel disease (CSVD) and renal dysfunction (RD) have been reported, but previous studies were mostly retrospective and limited to measurements of estimated glomerular filtration rate (eGFR). In this prospective, longitudinal study of patients with CSVD-related recent small subcortical infarcts (RSSI), we aimed at a comprehensive exploration of markers of early RD and their association with microvascular brain damage. We investigated 101 stroke patients (mean age: 60.2 ± 10.7 years) with an MRI-confirmed RSSI who underwent follow-up brain MRI 15 months post-stroke. Besides serum creatinine and eGFR, we assessed urinary Albumin-Creatinine Ratio and fibroblast growth factor-23 (FGF-23). RD was classified according to recent Kidney Disease: Improving Global Outcomes criteria. We identified 24 patients with RD, only six patients revealed an eGFR <60 mL/min/1.73 m². RSSI patients with RD more often had severe white matter hyperintensities (WMH, 58% vs. 36%, p = 0.04). CSVD progression was not dependent on RD. However, patients in the highest FGF-23 quartile more frequently had new microangiopathic lesions on follow-up MRI (50% vs. 21%, p = 0.03). Early RD was found in a quarter of RSSI patients and associated with WMH severity, but not CSVD progression. High FGF-23 indicates an increased risk for ongoing microvascular brain damage, warranting further studies.

Fibroblast Growth Factor-23 and Matrix Extracellular Phosphoglycoprotein Levels in Healthy Children and, Pregnant and Puerperal Women.

INTRODUCTION AND OBJECTIVE: Fibroblast growth factor (FGF-23) and matrix extracellular phosphoglycoprotein (MEPE) are bone-related factors and their role in physiologic conditions and in different life stages are unknown. We aimed to evaluate age- and pregnancy-related changes in MEPE and FGF-23 levels and their correlations with calcium (Ca)-phosphate (PO4) metabolism. METHODS: The study population included 96 healthy children (50 females) and 31 women (11 healthy, 10 pregnant, and 10 lactating). Intact FGF-23 (iFGF-23), MEPE, ferritin, parathyroid hormone (PTH), 25-OH vitamin D, alkaline phosphatase (ALP), IGF-I, IGFBP-3 and, Ca, PO4 and creatine (Cre) in serum (S) and urine (U) samples were determined. The renal phosphate threshold (TmPO4/GFR) and z-scores for the parameters that show age-related changes were calculated. RESULTS: Serum iFGF-23 concentrations showed nonsignificant changes with age; however, MEPE decreased with age, reaching the lowest levels after 7 years. Additionally, higher serum MEPE concentrations were observed during pregnancy. Other than ALP, all other examined parameters demonstrated age-related changes. ALP, BUN, S-Cre, and U-Ca/Cre showed puerperal and pregnancy related changes together with MEPE. iFGF-23 was positively correlated with S-PO4 and TmPO4/GFR. MEPE was positively correlated with S-Ca, S-PO4 and TmPO4/GFR and negatively correlated with PTH, IGF-1, and IGFBP-3. CONCLUSION: Not iFGF-23 but MEPE showed age-dependent changes and was affected by pregnancy. Although, MEPE and iFGF-23 did not correlate with each other, they seem to affect serum and urinary phosphate in the same direction. Additionally, we found evidence that ferritin and growth factors might have a role in serum calcium and phosphate regulation.

Serum and urine FGF23 and IGFBP-7 for the prediction of acute kidney injury in critically ill children.

BACKGROUND: Fibroblast growth factor 23 (FGF23) and insulin-like growth factor binding protein 7 (IGFBP-7) are suggested to be biomarkers for predicting acute kidney injury (AKI). We compared them with proposed AKI biomarker of cystatin C (CysC), and aimed (1) to examine whether concentrations of these biomarkers vary with age, body weight, illness severity assessed by pediatric risk of mortality III score, and kidney function assessed by estimated glomerular filtration rate (eGFR), (2) to determine the association between these biomarkers and AKI, and (3) to evaluate whether these biomarkers could serve as early independent predictors of AKI in critically ill children. METHODS: This prospective single center study included 144 critically ill patients admitted to the pediatric intensive care unit (PICU) regardless of diagnosis. Serum and spot urine samples were collected during the first 24 h after PICU admission. AKI was diagnosed based on the AKI network (AKIN) criteria. RESULTS: Twenty-one patients developed AKI within 120 h of sample collection, including 11 with severe AKI defined as AKIN stages 2 and 3. Serum FGF23 levels were independently associated with eGFR after adjustment in a multivariate linear analysis (P < 0.001). Urinary IGFBP-7 (Adjusted OR = 2.94 per 1000 ng/mg increase, P = 0.035), serum CysC (Adjusted OR = 5.28, P = 0.005), and urinary CysC (Adjusted OR = 1.13 per 1000 ng/mg increase, P = 0.022) remained significantly associated with severe AKI after adjustment for body weight and illness severity, respectively. Urinary IGFBP-7 level was predictive of severe AKI and achieved the AUC of 0.79 (P = 0.001), but was not better than serum (AUC = 0.89, P < 0.001) and urinary (AUC = 0.88, P < 0.001) CysC in predicting severe AKI. CONCLUSIONS: Serum FGF23 levels were inversely related to measures of eGFR. In contrast to serum and urinary FGF23 which are not associated with AKI in a general and heterogeneous PICU population, an increased urinary IGFBP-7 level was independently associated with the increased risk of severe AKI diagnosed within the next 5 days after sampling, but not superior to serum or urinary CysC in predicting severe AKI in critically ill children.

Associations of Fibroblast Growth Factor 23 with Markers of Inflammation and Leukocyte Transmigration in Chronic Kidney Disease.

BACKGROUND: Patients with chronic kidney disease (CKD) show elevated levels of inflammatory markers and have an increased risk of infections as well as cardiovascular morbidity. Recent studies have implied effects of fibroblast growth factor 23 (FGF23) on inflammation in CKD. We analyzed potential correlations between levels of FGF23 with pro-inflammatory chemokines and markers of leukocyte transmigration in CKD patients. METHODS: One hundred three patients with CKD 2-5ND and 54 healthy controls, had biochemical markers in blood and urine analyzed according to routine protocol. Pro-inflammatory cytokines were analyzed by Milliplex technique and leukocyte CD11b adhesion molecule expression was measured by flow cytometry. FGF23 levels were measured with ELISA technique. Treatment of leukocytes from healthy blood donors with FGF23 was performed in vitro and effects analyzed by flow cytometry. RESULTS: Tumor necrosis factor-alpha, RANTES and interleukin (IL)-12 levels were significantly higher (p = 0.001, p < 0.001, and p < 0.001) in patients with CKD. Elevated FGF23 levels in the CKD group correlated to glomerular filtration rate, parathyroid hormone, urinary albumin excretion and phosphate as well as to IL-12 and RANTES. CD11b expression on resting granulocytes and monocytes, and on activated monocytes, was associated with FGF23. In vitro treatment of leukocytes with FGF23 reduced CD11b expression in resting as well as in formyl-methyinoyl-leucyl-phenylalanine-stimulated granulocytes (p = 0.03). CONCLUSION: FGF23 levels are associated with various inflammatory markers such as pro-inflammatory cytokines and adhesion molecules on innate immune cells. However, further studies are warranted to define the direct role of FGF23 in modulation of the innate immune system in CKD.

Fibroblast Growth Factor 23 Levels Associate with AKI and Death in Critical Illness.

Elevated plasma levels of the osteocyte-derived hormone fibroblast growth factor 23 (FGF23) have emerged as a powerful biomarker of cardiovascular disease and death in patients with CKD. Whether elevated urinary or plasma FGF23 levels are prospectively associated with AKI and death in critically ill patients is unknown. We therefore conducted a prospective cohort study of 350 critically ill patients admitted to intensive care units at an academic medical center to investigate whether higher urinary FGF23 levels associate with the composite end point of AKI or in-hospital mortality (AKI/death). We measured urinary FGF23 levels within 24 hours of admission to the intensive care unit. In a subcohort (n=131) we also measured plasma levels of FGF23, calcium, phosphate, parathyroid hormone, and vitamin D metabolites. Urinary and plasma FGF23 levels, but not other mineral metabolites, significantly associated with AKI/death. In multivariate analyses, patients in the highest compared with the lowest quartile of urinary FGF23 had a 3.9 greater odds (95% confidence interval, 1.6 to 9.5) of AKI/death. Higher urinary FGF23 levels also independently associated with greater hospital, 90-day, and 1-year mortality; longer length of stay; and several other important adverse outcomes. In conclusion, elevated FGF23 levels measured in the urine or plasma may be a promising novel biomarker of AKI, death, and other adverse outcomes in critically ill patients.

Urine fibroblast growth factor 23 levels in hypertensive children and adolescents.

AIM: To determine the correlation of urinary fibroblast growth factor 23 (FGF23) excretion with blood pressure and calcium-phosphorus metabolism. METHODS: The study included 42 hypertensive (17 girls) and 46 healthy children and adolescents (17 girls) aged 6-18 years admitted to the Department of Pediatrics and Nephrology, Medical University of Bialystok between January 2013 and December 2013. FGF23 in urine was measured using Human Intact FGF-23 ELISA Kit. RESULTS: Hypertensive participants had significantly higher urine FGF23/creatinine values than the reference group (8.65 vs 5.59 RU/mg creatinine, P=0.007). Urine FGF23/creatinine positively correlated with systolic blood pressure in all participants. In hypertensive patients, urine FGF23/creatinine positively correlated with serum calcium and negatively with serum 25(OH)D, urinary calcium, phosphorus, and magnesium. CONCLUSION: This study found that FGF23 may play an important role in the pathogenesis of hypertension in children and adolescents, but our results should be confirmed by further studies.

Biomarkers of renal function, which and when?

PURPOSE OF THE REVIEW: Acute kidney injury (AKI) and chronic kidney disease (CKD) are conditions that substantially increase morbidity and mortality. Although novel biomarkers are being used in practice, the diagnosis of AKI and CKD is still made with surrogate markers of GFR, such as serum creatinine (SCr), urine output and creatinine based estimating equations. SCr is limited as a marker of kidney dysfunction in both settings and may be inaccurate in several situations, such as in patients with low muscle mass or with fluid overload. New biomarkers have the potential to identify earlier patients with AKI and CKD and in the future potentially intervene to modify outcomes. RECENT FINDINGS: In particular KIM-1 and NGAL are considered excellent biomarkers in urine and plasma for the early prediction of AKI; however cycle arrest biomarkers have emerged as novel markers for risk stratification of AKI. Urine TIMP-2 and IGFBP7 performed better than any other biomarkers reported to date for predicting the development of moderate or severe AKI. Biomarker combinations are required to increase diagnostic accuracy in an acute setting. NGAL, cystatin C, and FGF-23 are promising and accurate biomarkers for CKD detection. Equations combining cystatin C and SCr perform better than the equations using either cystatin C or SCr alone, especially in situations where CKD needs to be confirmed. Combining creatinine, cystatin C and urine albumin to creatinine ratio improves risk stratification for kidney disease progression and mortality. SUMMARY: Recent advances in molecular biology have resulted in promising biomarkers for AKI and CKD diagnoses; however more research is necessary to implement them successfully into clinical practice in order to facilitate early diagnosis, guide interventions and monitor disease progression. The following review describes the most important biomarkers studied in kidney disease and will discuss the use and the value of these biomarkers in different clinical settings.

A low fractional excretion of Phosphate/Fgf23 ratio is associated with severe abdominal Aortic calcification in stage 3 and 4 kidney disease patients.

BACKGROUND: Vascular calcification (VC) contributes to high mortality rates in chronic kidney disease (CKD). High serum phosphate and FGF23 levels and impaired phosphaturic response to FGF23 may affect VC. Therefore, their relative contribution to abdominal aortic calcification (AAC) was examined in patients CKD stages 3-4. METHODS: Potential risk factors for AAC, measured by the Kauppila Index (KI), were studied in 178 patients. RESULTS: In multivariate linear analysis, AAC associated positively with age, male gender, CKD-stage, presence of carotid plaques (CP) and also with FGF23, but negatively with fractional excretion of phosphate (FEP). Intriguingly, FEP increased with similar slopes with elevations in PTH, with reductions in GFR, and also with elevations in FGF23 but the latter only in patients with none (KI = 0) or mild (KI = 1-5) AAC. Lack of a FEP-FGF23 correlation in patients with severe AAC (KI > 5) suggested a role for an impaired phosphaturic response to FGF23 but not to PTH in AAC. Logistic and zero-inflated analysis confirmed the independent association of age, CKD stage, male gender and CP with AAC, and also identified a threshold FEP/FGF23 ratio of 1/3.9, below which the chances for a patient of presenting severe AAC increased by 3-fold. Accordingly, KI remained unchanged as FEP/FGF23 ratios decreased from 1/1 to 1/3.9 but markedly increased in parallel with further reductions in FEP/FGF23 < 1/3.9. CONCLUSIONS: In CKD 3-4, an impaired phosphaturic response to FGF23 with FEP/FGF23 < 1/3.9 associates with severe AAC independently of age, gender or CP.

FGF23 and mineral metabolism in the early post-renal transplantation period.

BACKGROUND: The relationship between fibroblast growth factor 23 (FGF23) and vitamin D production and catabolism post-renal transplantation has not been characterized. METHODS: Circulating creatinine, calcium, phosphorus, albumin, parathyroid hormone, FGF23, and 1,25(OH)2 vitamin D (calcitriol) values were obtained pre-transplantation, daily post-operatively for 5 days, and at 6 months post-transplantation in 44 patients aged 16.4 ± 0.4 years undergoing renal transplantation at UCLA from 1 August 2005 through to 30 April 2007. 25(OH) Vitamin D and 24,25(OH)2 vitamin D concentrations were obtained at baseline and on post-operative days 5 and 180, and urinary concentrations of creatinine, phosphorus, and FGF23 were measured on post-operative days 1, 3, 5, and 180. RESULTS: Circulating phosphate concentrations declined more rapidly and the fractional excretion of phosphorus was higher in the first week post-transplantation in subjects with higher FGF23 values. Fractional excretion of FGF23 was low at all time-points. Circulating 1,25(OH)2 vitamin D levels rose more rapidly and were consistently higher in patients with lower FGF23 values; however, 25(OH) vitamin D and 24,25(OH)2 vitamin D values were unrelated to FGF23 concentrations. CONCLUSIONS: Inhibition of renal 1α-hydroxylase, rather than stimulation of 24-hydroxylase, may primarily contribute to the relationship between FGF23 values and calcitriol. The rapid decline in FGF23 levels post-transplantation in our patient cohort was not mediated solely by the filtration of intact FGF23 by the new kidney.

Paediatric reference values for the C-terminal fragment of fibroblast-growth factor-23, sclerostin, bone-specific alkaline phosphatase and isoform 5b of tartrate-resistant acid phosphatase.

BACKGROUND: Paediatric reference values for novel markers of phosphate homeostasis, bone formation and resorption and their putative relationship to growth are lacking. METHODS: A total of 424 healthy children, adolescents and young adults (221 males) aged 0.1-21 y, were enrolled in this cross-sectional study. Height, weight and height velocity were assessed. Plasma/serum samples for determination of C-terminal fragment of fibroblast growth factor-23 (cFGF-23), sclerostin, bone alkaline phosphatase (BAP) and tartrate-resistant acid phosphatase 5b (TRAP5b) were available from 222, 264, 352 and 338 individuals, respectively. Calculation of cross-sectional centiles and z-scores was based on median (M), standard coefficient of variation (S) and the Box-Cox power (L) of transformation (LMS method) per age cohort. Correlations between variables as well as with growth were assessed. RESULTS: cFGF-23, BAP and TRAP5b were significantly correlated with age (each P < 0.01), with highest values during infancy and adolescence. Serum levels of BAP and TRAP5b were significantly higher in adolescent boys compared with girls (each P < 0.01). In contrast, sclerostin levels were independent of age and gender. BAP and TRAP5b were strongly correlated and both were significantly associated with cFGF-23 and sclerostin as well (each P < 0.01). cFGF-23 was positively correlated with serum phosphate and renal phosphate threshold concentration (each P < 0.01). Height, weight, body mass index and height velocity were weakly correlated with BAP and TRAP5b (each P < 0.05). CONCLUSIONS: This study provides age- and gender-related centile charts and z-scores for cFGF-23, BAP, TRAP5b and sclerostin and highlights the link between phosphate homeostasis and markers of bone metabolism during growth.

Fibroblast growth factor 23 in patients undergoing peritoneal dialysis.

BACKGROUND AND OBJECTIVES: Fibroblast growth factor 23 (FGF23) is an independent risk factor for mortality in patients with ESRD. Before FGF23 testing can be integrated into clinical practice of ESRD, further understanding of its determinants is needed. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: In a study of 67 adults undergoing peritoneal dialysis, we tested the hypothesis that longer dialysis vintage and lower residual renal function and renal phosphate clearance are associated with higher FGF23. We also compared the monthly variability of FGF23 versus parathyroid hormone (PTH) and serum phosphate. RESULTS: In unadjusted analyses, FGF23 correlated with serum phosphate (r = 0.66, P < 0.001), residual renal function (r = -0.37, P = 0.002), dialysis vintage (r = 0.31, P = 0.01), and renal phosphate clearance (r = -0.38, P = 0.008). In adjusted analyses, absence of residual renal function and greater dialysis vintage associated with higher FGF23, independent of demographics, laboratory values, peritoneal dialysis modality and adequacy, and treatment with vitamin D analogs and phosphate binders. Urinary and dialysate FGF23 clearances were minimal. In three serial monthly measurements, within-subject variability accounted for only 10% of total FGF23 variability compared with 50% for PTH and 60% for serum phosphate. CONCLUSIONS: Increased serum phosphate, loss of residual renal function, longer dialysis vintage, and lower renal phosphate clearance are associated with elevated FGF23 levels in ESRD patients undergoing peritoneal dialysis. FGF23 may be a more stable marker of phosphate metabolism in ESRD than PTH or serum phosphate.

Effects of dietary phosphate and calcium intake on fibroblast growth factor-23.

BACKGROUND AND OBJECTIVES: Little is known about the influence of dietary phosphate intake on fibroblast growth factor-23 (FGF23) and its subsequent effects on vitamin D levels. This study addresses changes in intact FGF23 (iFGF23) and C-terminal FGF23 (cFGF23), phosphaturia, and levels of vitamin D on high and low phosphate and calcium intake. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: Ten healthy subjects adhered to a diet low or high in phosphate and calcium content for 36 hours each with a 1-week interval during which subjects adhered to their usual diet. Serum phosphate, calcium, vitamin D metabolites, parathyroid hormone (PTH), and FGF23 levels (cFGF23 and iFGF23) were measured several times a day. Phosphate, calcium, and creatinine excretion was measured in 24-hour urine on all study days. RESULTS: Serum phosphate levels and urinary phosphate increased during high dietary phosphate intake (from 1.11 to 1.32 mmol/L, P<0.0001 and 21.6 to 28.8 mmol/d, P=0.0005, respectively). FGF23 serum levels increased during high dietary phosphate/calcium intake (cFGF23 from 60 to 72 RU/ml, P<0.001; iFGF23 from 33 to 37 ng/L, P=0.003), whereas PTH declined. 1,25-dihydroxyvitamin D (1,25D) showed an inverse relation with FGF23. CONCLUSIONS: Variation in dietary phosphate and calcium intake induces changes in FGF23 (on top of a circadian rhythm) and 1,25D blood levels as well as in urinary phosphate excretion. These changes are detectable the day after the change in the phosphate content of meals. Higher FGF23 levels are associated with phosphaturia and a decline in 1,25D levels.

A phase I, pharmacokinetic and pharmacodynamic dose escalation trial of weekly paclitaxel with interferon-alpha2b in patients with solid tumors.

PURPOSE: Paclitaxel and interferon have demonstrated anti-angiogenic activity in vitro and in vivo. The toxicity, pharmacokinetics, and pharmacodynamics of paclitaxel with interferon-alpha2b (IFN-alpha2b) were assessed in patients with solid tumors to assess the feasibility of this novel anti-angiogenic regimen. METHODS: IFN-alpha2b (1 million units) was administered twice daily by subcutaneous injection. Paclitaxel was given weekly over 1 h starting at 30 mg/m2 and increased to 50 mg/m2. Cycles were repeated every 4 weeks. RESULTS: Nineteen patients with a variety of solid tumors were enrolled. Dose-limiting toxicity in cycle 1 was observed at 50 mg/m2. Eleven patients were treated at 40 mg/m2 with no undue toxicity. Pharmacokinetic parameter comparison studies were completed in 11 patients who received days 1 and 29 paclitaxel. Mean paclitaxel clearance and area under the curve (0-infinity) were not statistically different from days 1 to 29. There was a 50% increase in the average Cmax from days 1 to 29. There was also a 73% decrease of matrix metalloproteinase-9 (MMP-9) levels in these 11 patients from days 1 to 29 (p < 0.0005). All three patients with cutaneous angiosarcomas experienced clinically meaningful remissions. In addition, minor responses were observed in one patient with heavily pretreated ovarian cancer and another with adrenocortical carcinoma. CONCLUSION: This trial details the inability to dose escalate to the maximum tolerated dose of weekly paclitaxel when combined with low-dose interferon. However, this low-dose regimen caused a significant decrease in MMP-9 and demonstrated anti-cancer activity in cutaneous angiosarcomas.

The role of fibroblast growth factor 23 for hypophosphatemia and abnormal regulation of vitamin D metabolism in patients with McCune-Albright syndrome.

McCune-Albright syndrome (MAS) is sometimes complicated by hypophosphatemia and abnormally low levels of 1,25(OH)(2)D in the presence of hypophosphatemia. Recently, fibroblast growth factor 23 (FGF-23) was reported as a phosphaturic and a causal factor of abnormal vitamin D metabolism. This abnormal phosphate and vitamin D metabolism is well known to be found in oncogenic and X-linked hypophosphatemia. We furthermore reported increased circulating plasma FGF-23 levels in patients with oncogenic and X-linked hypophosphatemia. To determine whether FGF-23 may be involved in the pathogenesis of MAS, we measured plasma FGF-23 levels in six MAS patients. As a control for hypophosphatemia, we also investigated the plasma FGF-23 levels in two patients with hereditary hypophosphatemic rickets with hypercalciuria (HHRH). We also investigated the correlation of plasma FGF-23 levels with serum phosphate and 1,25(OH)(2)D levels after short-term pamidronate therapy in three MAS patients. Plasma FGF-23 levels were significantly increased in patients with MAS compared to normal controls, whereas they were not increased in HHRH patients. Serum phosphate levels of the MAS patients were significantly lower than those observed in normal controls. Plasma FGF-23 levels showed significant negative correlation with serum phosphate concentrations. In three MAS patients, pamidronate therapy decreased plasma FGF-23 levels, which showed significant negative correlation with serum 1,25(OH)(2)D concentrations. These data suggested that FGF-23 is a possible causal factor for hypophosphatemia and abnormal vitamin D metabolism in MAS.

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.

Phase I trial of the angiogenesis inhibitor TNP-470 for progressive androgen-independent prostate cancer.

Clinical and laboratory observations support the view that angiogenesis is necessary for prostate cancer progression. The angiogenesis inhibitor TNP-470 has demonstrated in vivo antitumor activity in a series of clinical models. To evaluate a possible therapeutic clinical value, we conducted a Phase I dose escalation trial of alternate-day i.v. TNP-470 in 33 patients with metastatic and androgen-independent prostate cancer. The patients were evaluated during therapy for evidence of neurological toxic effects. An assay of endothelial and vascular proliferation "markers" and a sequential assay of serum prostate-specific antigen concentration were performed. The effects of TNP-470 could be evaluated in 32 of the 33 patients. The maximum tolerated dose was 70.88 mg/m(2) of body surface area. The dose-limiting toxic effect was a characteristic neuropsychiatric symptom complex (anesthesia, gait disturbance, and agitation) that resolved upon cessation of therapy. The times to clinical recovery of neurological side effects were 6, 8, and 14 weeks. No definite antitumor activity of TNP-470 was observed; however, transient stimulation of the serum prostate-specific antigen concentration occurred in some of the patients treated. Additional studies of TNP-470 should be conducted using an alternate-day i.v. injection of 47.25 mg/m(2) body surface area and should focus on understanding and overcoming the neurological toxic effects. In addition, valid intermediate end points that reflect the status of tumor-associated neovascularity are needed to facilitate effective development of treatment strategies.

Angiogenic factors as tumor markers.

The process of angiogenesis plays a critical role in tumor growth and metastasis. Recently, there has been much interest in the possible use of angiogenic growth factors as tumor markers. This paper will review the results thus far of attempts at measuring various angiogenic factors in bodily fluids. In the future, angiogenic factors will most likely be useful as a monitor of therapy and/or a predictor of outcome after cancer has been diagnosed.

Pharmacokinetic and autoradiographic studies of basic fibroblast growth factor on de-epithelialized and intact rabbit eye.

In a previous work, we showed and compared the wound healing properties of aFGF and bFGF topically administered on totally de-epithelialized rabbit corneas. Pharmacokinetic and autoradiographic studies were then performed to investigate the sites of accumulation of bFGF in ocular structures, both on de-epithelialized and intact rabbit eyes. After one single instillation of 125I-bFGF, all the ocular structures were dissected and the measurement of the radioactivity allowed to establish kinetic curves. The results showed a very important and early fixation of bFGF on denuded cornea (10 minutes) and a posterior distribution of the drug between 10 and 30 minutes. A second accumulation of bFGF in the anterior segment appeared 8 hours after application and then decreased till the 48th hour. These findings were confirmed by the macroautoradiographies and the microautoradiographies pointed out the fixation of bFGF not only at the location of the Bowman membrane, but also on the corneal endothelium. These experiments also demonstrated the systemic diffusion of bFGF into the untreated controlateral eye. The integrity of bFGF in the cornea and other structures was then confirmed by SDS PAGE followed by autoradiography. In the intact eye, bFGF was shown to penetrate in extremely low amounts, illustrating the major role of the corneal barrier. For a therapeutic use bFGF may be recommended as an efficient wound healing agent for epithelial but also endothelial defects. Its eventual unwanted side effects must be kept in mind to perfect an efficient low dose and short term clinical treatment.