Cellular Potassium Ion Deprivation Enhances Apoptosis Induced by Cisplatin

The anticancer drug cisplatin induces cell death by apoptosis. Apoptosis is dependent on cellular loss of potassium ions (K+). We have recently shown that the antifungal drug amphotericin B (enhancing K+ efflux), combined with the Na+, K+, 2Cl(-)-cotransport blocker bumetanide (decreasing K+ influx), augmented cisplatin-induced apoptosis in vitro. We therefore quantified K+ fluxes with the K+ analogue rubidium (86Rb+) in cisplatin-induced apoptosis of mesothelioma cells treated with bumetanide and amphotericin B. Bumetanide combined with amphotericin B enhanced cisplatin-induced apoptosis by a pronounced initial reduction of K+ influx due (in addition to Na+, K+, 2Cl(-)-cotransport inhibition) also to Na+, K+, ATPase pump inhibition. As 86Rb+ efflux was initially preserved, combination of the drugs would lead to net K+ loss. Combinations of K+ flux modulators leading to cellular potassium ion deprivation thus augments cisplatin-induced apoptosis and could therefore possibly be used to enhance the antitumour efficacy of cisplatin treatment.

Expression of vascular endothelial growth factor protein in human renal cell carcinoma

OBJECTIVE

To evaluate the effect of vascular endothelial growth factor (VEGF, one of the most important angiogenetic factors) in renal cell carcinoma (RCC) by analysing many RCCs for the expression of immunohistochemical (IHC) VEGF-staining related to clinicopathological findings and survival.

PATIENTS AND METHODS

VEGF immunostaining was examined with the tissue microarray (TMA) method on tumour samples from 229 patients and validated in 71 by ordinary tissue sections (TS). IHC VEGF expression was quantified by estimating the volume density and staining intensity on a three-grade scale.

RESULTS

In most RCCs there was VEGF staining in the cell cytoplasm and membrane. In cell membranes the VEGF expression declined with storage time. IHC VEGF expression analysed by TMA and TS gave corresponding results. There was no difference in VEGF expression among conventional, papillary and chromophobe RCCs. There were significant correlations between VEGF expression and tumour size and stage. In univariate analysis VEGF expression correlated with survival, especially in conventional RCCs; this prognostic information was lost in multivariate analysis. The VEGF staining intensity correlated only with VEGF expression but not with any clinicopathological factors.

CONCLUSIONS

VEGF protein was present in most RCC cells. There was no difference in VEGF expression among the different RCC types. The correlation between VEGF expression and tumour stage and with prognosis indicates the significance of VEGF within tumour growth and progression in RCC.

Overexpression of c-erbB-2 is related to a higher expression of vascular endothelial growth factor (VEGF) and constitutes an independent prognostic factor in primary node-positive breast cancer after adjuvant systemic treatment

The aim of this study was to investigate possible associations between the expression of c-erbB-2 and the angiogenic factors vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF), p53 status, routine breast cancer prognostic factors and survival. Expression of c-erbB-2, VEGF, bFGF, and p53 protein was determined with an enzyme-linked immunosorbent assay (ELISA) in 656 patients with primary breast cancer (median follow-up time of 83 months). In 60 cases, we also used immunohistochemistry (IHC) for c-erbB-2 evaluation, to be used as a reference for the ELISA. Overexpression of c-erbB-2 was significantly related to a higher expression of VEGF, lower bFGF content, negative steroid receptor status, and a high S-phase fraction. In multivariate analysis, c-erbB-2 was an independent prognostic factor for relapse-free survival (RFS) and overall survival (OS) in all patients, and in node-positive patients, irrespective of the adjuvant systemic therapy. Combined survival analyses regarding c-erbB-2 and VEGF yielded additional prognostic information.

Prognostic Correlation of Basic Fibroblast Growth Factor and Vascular Endothelial Growth Factor in 1307 Primary Breast Cancers

This study was designed to investigate the possible relationship between the protein expression of basic fibroblast growth factor (bFGF) and vascular endothelial growth factor (VEGF) with p53 status, breast cancer prognostic factors, metastatic site, and survival after adjuvant therapy. Basic fibroblast growth factor and VEGF expression were determined by enzyme-linked immunosorbent assays in cytosol specimens obtained from 1307 patients with T1-3 primary breast cancer (789 node-negative, 518 node-positive) diagnosed between 1990 and 1997. The median follow-up time was 70 months. Increased bFGF expression was more frequently found in tumors with low VEGF expression (r = -0.286; P = 0.095). Increased bFGF was associated with smaller tumors (P < 0.001), absence of axillary metastasis (P = 0.003), low S-phase fraction (P < 0.001), and longer recurrence-free survival (RFS; P = 0.0038) and overall survival (OS; P = 0.0316). Vascular endothelial growth factor was a prognostic factor for RFS (P < 0.0001) and OS (P < 0.0001) in univariate and multivariate analyses (RFS: 95% CI, 1.1-1.7; P = 0.036; OS: 95% CI, 1.2-2.2; P = 0.002), whereas bFGF expression was not correlated with RFS or OS. Increased VEGF content was correlated with shorter survival after adjuvant endocrine therapy (RFS, P = 0.0004; OS, P = 0.0009). Patients with estrogen receptor-negative disease were excluded from the analysis. Basic fibroblast growth factor was not a prognostic factor after adjuvant systemic therapy, nor was it related to metastatic site. Expression of VEGF is an independent prognostic factor for patients with primary breast cancer. High bFGF expression was related to good prognostic features and longer survival times, but did not add prognostic information in multivariate analysis. The results might implicate that different angiogenic pathways exist in human breast cancer.

Tumour vascular endothelial growth factor (VEGF) mRNA in relation to serum VEGF protein levels and tumour progression in human renal cell carcinoma

Angiogenesis is gaining interest because of its importance in tumour growth and metastasis. Renal cell carcinoma (RCC) is known to be a well-vascularized tumour. The aim of this study was to evaluate the expression of VEGF mRNA and receptor flt-1 mRNA (VEGF R1) in a clinical material of RCCs compared with clinicopathological variables and serum VEGF levels. Total RNA was extracted from snap-frozen tumour tissue obtained from 61 patients. Expression of mRNA for VEGF121, VEGF165 and flt-1 were analysed using quantitative RT-PCR. Relative VEGF mRNA levels, corrected for corresponding cyclophilin value, were related to stage, grade, RCC type and survival time. Serum VEGF165 protein was analysed using a quantitative ELISA. Papillary RCC had significantly lower VEGF121 and flt-1 mRNA levels compared with conventional RCC (p=0.001). VEGF121 mRNA levels were significantly lower in locally advanced tumours in relation to tumours limited to the kidney and those with metastatic disease (p=0.047 and p=0.036). This statistical difference disappeared when only conventional RCCs were evaluated. No association was found between VEGF mRNA levels and nuclear grade. Patients with lower VEGF121 mRNA levels had significantly longer survival time compared with those with higher levels (when adjusted to stage, p=0.0097, log rank test). There was an inverse relation between VEGF165 mRNA and serum VEGF165 levels. The trend to lower VEGF121 mRNA levels in locally advanced RCC indicate that angiogenic activity and degradation might be up-regulated in tumours with a high ability to invade. The association with tumour progression shows that VEGF is a promising angiogenic factor especially important in conventional RCCs. VEGF expression might possibly be of help to identify RCCs susceptible for anti-angiogenic therapies.

Ondansetron but not granisetron affect cell volume regulation and potassium ion transport of glioma cells treated with estramustine phosphate

PURPOSE

Highly 5-HT(3)-receptor-specific antiemetic agents may have different effects on ion transport of tumour cells during treatment with cytotoxic drugs. Cell volume regulation, which is dependent on potassium ion (K(+)) flux, is involved the control of cell growth, proliferation, and apoptosis. K(+)-flux response mechanisms to the antiemetics ondansetron and granisetron were therefore correlated to malignant glioma cell (Mg251) volume response to estramustine phosphate (EMP) in vitro.

METHODS

We quantified the influx and efflux of potassium ions (using the K(+) analogue (86)Rb(+)) as well as cell volume changes (with image analysis) of glioma cells incubated with the 5-HT(3)-receptor antagonists ondansetron and granisetron (0.1 micro mol/l) combined with 40 mg/l EMP.

RESULTS

The EMP-induced cell volume increase was fully inhibited by ondansetron but not affected by granisetron. Ondansetron retained high cellular K(+)-efflux and reduced Na(+), K(+), 2Cl(-)-cotransport activity, whereas granisetron (0.1 micro mol/l) reduced K(+)-efflux and retained an augmented Na(+), K(+), 2Cl(-)-cotransport activity in the presence of 40 mg/l EMP.

CONCLUSIONS

Ondansetron affects K(+) transport with ensuing effects on cell volume of tumour cells treated with EMP, whereas granisetron does not. Since ondansetron and other 5-HT(3)-receptor antagonists are used routinely to prevent nausea during anticancer treatment, an increased awareness of possible interactions with the antitumour efficacy of anticancer drugs seems warranted.

Prognostic importance of serum vascular endothelial growth factor in relation to platelet and leukocyte counts in human renal cell carcinoma

It has been shown that both serum vascular endothelial growth factor (VEGF) and also platelet counts are associated with survival in renal cell carcinoma (RCC). It is not known, however, whether VEGF in serum relates to the angiogenic activity of the tumour or is derived from circulating blood components. Therefore, the interrelation between serum VEGF, platelet and leukocyte counts compared with health history, clinicopathological findings and outcome was evaluated in patients with RCC. Blood samples were collected before nephrectomy in 161 patients. Serum VEGF165 was assessed by a quantitative ELISA method. Platelet and leukocyte counts were analysed routinely and obtained from medical records. The variables were compared using univariate and multivariate analysis. There were significant correlations between VEGF levels, and platelet (P < 0.001) and leukocyte counts (P < 0.001). Serum VEGF levels, platelet counts, as well as leukocyte counts correlated significantly to stage and grade. Platelet counts were significantly lower in men with medication (P = 0.042), and decreased with age particularly in women (P = 0.001). Age or medication did not affect VEGF levels or leukocyte counts. Both VEGF and platelets gave significant prognostic information in univariate analysis. Using Cox multivariate analysis, VEGF was the last variable to be excluded. Only stage and grade remained as independent prognostic factors. Both VEGF levels and platelet counts gave prognostic information but VEGF was more reliable as predictor of survival in patients with RCC.

Rapid induction of long-lasting drug efflux activity in brain vascular endothelial cells but not malignant glioma following irradiation

The influence of radiotherapy on malignant glioma multidrug resistance to chemotherapy was evaluated because patients with glioma often are treated with a combination of radiotherapy and chemotherapy. Multidrug resistance gene (MDR1, mdr1a, and mdr1b) transcripts were found in human and rat glioma cell lines. P-Glycoprotein (Pgp) was immunohistochemically detected in glioma cell lines and in the rat brain vascular endothelial cell line (RBE4). A multidrug resistance pump efflux activity assay demonstrated increased calcein efflux of RBE4 endothelial cells, but not glioma cells, 2 h after irradiation and still increased 14 d after irradiation. The increased efflux was equally inhibited by verapamil with or without irradiation. In the rat intracranial glioma model (BT4C), Pgp was demonstrated in capillary endothelial cells of the tumor tissue and surrounding normal brain, but not in tumor cells. The expression of gene transcripts or Pgp was not affected by irradiation. The results indicate that long-lasting verapamil-resistant drug efflux mechanisms are activated in brain endothelial cells after irradiation. The results might explain the poor efficacy of chemotherapy following radiotherapy and contribute to consideration of new treatment strategies in the management of malignant glioma.

Bumetanide annihilation of amphotericin B-induced apoptosis and cytotoxicity is due to its effect on cellular K+ flux

The antifungal antibiotic amphotericin B causes considerable toxic effects during clinical therapy. We have shown previously that amphotericin B-induced cytotoxicity and apoptosis were eradicated by the Na+, K+, 2Cl- cotransport inhibitor bumetanide. To elucidate the role of K+ flux and the activity of Na+, K+ ATPase and Na+, K+, 2Cl- cotransport in apoptosis and cytotoxicity induced by amphotericin B alone and combined with bumetanide, we quantified the influx and efflux of K+ of mesothelioma cells (P31) using the K+ analogue 86Rb+ with ouabain (100 micromol/L) as the K+ influx probe. To determine the susceptibility of Candida albicans to amphotericin B when combined with bumetanide we used a plate diffusion method. Amphotericin B or bumetanide alone significantly stimulated 86Rb+ efflux during the first 15 min. However, when added simultaneously, the cellular 86Rb+ efflux was markedly decreased. Amphotericin B (3 mg/L) had no effect on immediate (15 min) total 86Rb+ influx. When bumetanide (100 micromol/L) was added, the total 86Rb+ influx was markedly reduced due to inhibition of augmented Na+, K+, 2Cl- cotransport and low Na+, K+ ATPase activity. Bumetanide did not affect the susceptibility of C. albicans to amphotericin B, which suggests that bumetanide or related drugs could be used in antifungal therapy to increase amphotericin B effectiveness without increasing its adverse effects. We suggest that bumetanide hampering of amphotericin B-induced cytotoxicity and apoptosis could be due to an immediate reduction of cellular K+ efflux as well as disordered K+ influx.

Impact of serum basic fibroblast growth factor on prognosis in human renal cell carcinoma

Renal cell carcinoma is often characterised by extensive vascularity and angiogenic factors may be of importance for disease progression. Using a sandwich enzyme immunoassay, basic fibroblast growth factor (bFGF) was analysed in the sera from 206 patients with renal cell carcinoma before the initiation of therapy. The median bFGF level was 3.0 pg/ml (range <1.0-70.9 pg/ml). The serum levels were significantly correlated to tumour stage and nuclear grade. Patients with tumour thrombus to the renal or the inferior caval vein had significantly higher serum bFGF levels compared with those with non-invading tumours (P=0.007). Patients with serum bFGF levels above 3.0 pg/ml had a worse prognosis, compared with those with lower levels (P=0.001). Furthermore, patients with tumours with vein invasion had a worse prognosis compared with those without invasion. After multivariate analysis, only tumour stage and grade remained as independent prognostic factors.

Cisplatin-induced apoptosis of mesothelioma cells is affected by potassium ion flux modulator amphotericin B and bumetanide

Chemotherapeutic anti-cancer drugs induce cell death by the process of apoptosis. Efflux of potassium ions (K(+)) is necessary for cell volume reduction during apoptosis and increased inward pumping of K(+) thus counteracts apoptosis. Potassium flux modulation could therefore interact with apoptosis and affect the efficiency of cancer chemotherapeutics. We explored if the K(+) efflux stimulator amphotericin B, with or without the Na(+), K(+), 2Cl(-)-cotransport (K(+) influx) blocker bumetanide, could affect cisplatin- and carboplatin-induced apoptosis and cytotoxicity in the pulmonary mesothelioma cell line (P31). Apoptosis was determined by quantifying free nucleosomes and caspase-3 activity, and cytotoxicity was determined by clone formation and a fluorometric assay. The pan-caspase enzyme inhibitor Boc-D-FMK was used to further determine the role of caspase activity in K(+)-flux-modulated cisplatin-/carboplatin-induced apoptosis and cytotoxicity. Amphotericin B (3.2 micromol/L) combined with bumetanide (100 micromol/L) potentiated cisplatin-induced free nucleosome and caspase-3 activity. The combination of the K(+) modulators did not, however, increase cisplatin cytotoxicity. The caspase inhibitor Boc-D-FMK, but unexpectedly also bumetanide, markedly reduced cisplatin cytotoxicity and annihilated the augmented cytotoxicity of cisplatin in the presence of amphotericin B. Carboplatin cytotoxicity was reduced by bumetanide, but not affected by amphotericin B. Carboplatin and carboplatin/bumetanide cytotoxicity was further reduced by Boc-D-FMK. We conclude that the ability of cisplatin, and to a lesser extent carboplatin, to induce apoptosis is indeed influenced by cellular potassium flux modulators. We suggest that K(+) ionophores such as amphotericin B, and K(+) influx blockers such as bumetanide, alone or in combination, should be further evaluated for their potential clinical usefulness in influencing tumor cell apoptosis induced by cisplatin and other cancer chemotherapeutics.

Increased serum cortisol levels are associated with high tumour grade in patients with renal cell carcinoma

Cortisol and dehydroepiandrosterone (DHEA) and its sulphate (DHEAS) are the major steroid hormones produced by the human adrenal cortex. The serum levels of cortisol and DHEAS were analysed in 211 consecutive patients with renal cell carcinoma before initiation of therapy. Serum cortisol was significantly higher in patients with renal cell carcinoma compared with that in patients with benign cysts (p < 0.0001). Serum cortisol was independent of disease stage, but positively correlated to tumour diameter and grade. The serum levels of DHEAS were higher in men than in women, and decreased with age, but did not correlate with disease stage, tumour diameter or grade. The prognosis of patients with elevated serum cortisol tended to be poorer (p = 0.06) than the prognosis of those with lower levels. In a multivariate analysis, disease stage and tumour grade were independent predictors of prognosis. Age, gender and serum levels of cortisol and DHEAS were of limited value for prognosis.

Diverging effects of 5-HT3 receptor antagonists ondansetron and granisetron on estramustine-inhibited cellular potassium transport

We used 86Rb+ (K+ analogue) to study potassium influx during the interaction of highly specific 5-HT3-receptor antagonists, ondansetron and granisetron, with the effects of the anticancer drug, estramustine phosphate, on P31 mesothelioma cells. Estramustine phosphate (80 mg/l, 142 micromol/l) for 120 min. reduced 86Rb+ influx by 18.7%. The reduction was inhibited by ondansetron (0.1 micromol/l), but augmented by granisetron (0.1 micromol/l). Serotonin (1.0 micromol/l) antagonized ondansetron inhibition and restored granisetron-augmented reduction of estramustine phosphate-induced 86Rb+ influx to the level of the drug itself. Estramustine phosphate inhibited cellular Na+, K+, 2Cl- -cotransport activity whereas Na+, K+, ATPase activity was unaffected. Ondansetron blockade of estramustine phosphate-induced reduction of 86Rb+ influx was due to increased Na+, K+, ATPase and Na+, K+, 2Cl- -cotransport whereas augmentation of estramustine phosphate-induced reduction of 86Rb+ influx by granisetron, or combination of 5-HT3 receptor antagonists with serotonin was due mainly to inhibition of cellular Na+, K+, ATPase activity Thus, ondansetron possesses a distinct ability to reverse K+ influx of tumour cells exposed to estramustine phosphate whereas granisetron does not, due to different effect on cellular Na+, K+, ATPase and Na+, K+, 2Cl- -cotransport activity. Highly 5-HT3 receptor-specific antiemetic agents may have different effects on ion transport of tumour cells during treatment with cytotoxic drugs.

Amphotericin B-induced apoptosis and cytotoxicity is prevented by the Na+, K+, 2Cl(-)-cotransport blocker bumetanide

Amphotericin B is the most commonly used antifungal drug although it exhibits poor effectiveness and considerable toxicity during treatment. It acts as a ionophore inducing cellular potassium efflux. The efflux of potassium, which is necessary for cell shrinkage during apoptosis, is counteracted by increased inward pumping of potassium ions. Modulation of potassium pump activity could therefore interact with programmed cell death depending on the nature of the disruption of cellular potassium homeostasis and subsequently affect the cytotoxicity of various drugs. We explored the role of apoptosis in amphotericin B-induced cytotoxicity in a mesothelioma cell line (P31) and investigated the role of K+ influx inhibitors of Na+, K+, ATPase and Na+, K+, 2Cl(-)-cotransport in these processes. Clone formation was used to determine the cytotoxicity of amphotericin B, ouabain (Na+, K+, ATPase blocker), and bumetanide (Na+, K+, 2Cl(-)-cotransport blocker), alone or in combination. Apoptosis was estimated by quantifying free nucleosomes. Amphotericin B (3.2 micromol/L, 3 mg/L) per se reduced the percentage of surviving clones to 64% and increased the number of nucleosomes by 31% compared to untreated control. When ouabain (100 micromol/L) was added to amphotericin B a less than additive effect on clone formation was seen but no reduction of nucleosomes was noted. Bumetanide (100 micromol/L) per se was not cytotoxic but increased cellular nucleosome expression. Bumetanide eradicated amphotericin B-induced reduction of formed clones and generated nucleosomes. In conclusion, the induction of apoptosis seems to be of significant importance in amphotericin B-induced cytotoxicity. Amphotericin B-induced cytotoxicity and apoptosis was eradicated by the Na+, K+, 2Cl(-)-cotransport inhibitor bumetanide. The changes of cellular K+ fluxes induced by bumetanide combined with amphotericin B needs further elucidation. Bumetanide could possibly be used in antifungal therapy to increase amphotericin B effectiveness doses without increasing its adverse effects.

Response in shape and size of individual p31 cancer cells to cisplatin and ouabain: a computerized image analysis of cell halo characteristics during continuous perfusion

BACKGROUND

Volume regulation is essential for cellular functions, including cell death, such as apoptosis. Flow cytometry is standard for nonadherent cells, such as blood cells. Our aim was to explore image analysis methods to study adherent cancer cells of a solid tumor.

METHODS

P31 mesothelioma cells were perifused (40 min) and studied by phase-contrast microscopy. A noise reduction of the cell contour was tested to more accurately yield the cell shape factor (SF). The optical halo around the cell was analyzed for information about membrane blebbing.

RESULTS

The projected cell area (PCA) slowly increased under control perfusion, the halo outside more than the halo inside. Cisplatin (apoptosis) caused an immediate increase in the PCA-halo outside (5.9 +/- 1.2 %, P < 0.01, 1-5 min) and the SF indicated decreased roundness (P < 0.05). The SF-halo inside became more irregular than the outside, which was different from the control cells. The morphology reflected instant blebbing, and the cell bodies showed fragmentation after about 20 min. Ouabain resulted in only small changes in PCA and SF, significantly different from both control and cisplatin conditions.

CONCLUSIONS

Image analysis (PCA and SF) on perifused adherent cancer cells may serve as a tool to follow the sensitivity of cancer chemotherapy and to study cell death patterns.

Physical symptoms in premenstrual syndrome are related to plasma progesterone and desoxycorticosterone

Somatic symptoms in the premenstrual syndrome (PMS) may have an etiology separate from that of the mental symptoms. A disturbance in mineralocorticoid action has been discussed, as mineralocorticoids regulate water balance. Desoxycorticosterone (DOC) is interesting, as it has mineralocorticoid effects and is a precursor to the neurosteroid 5 alpha-pregnan-3 alpha,21-diol-20-one (THDOC). THDOC is a steroid with direct benzodiazepine-like effects on the GABA-A receptor in the brain that is metabolized from DOC within the brain and in the periphery. Ten women with PMS having swelling as a major symptom and eight controls were recruited. They marked, on a validated visual-analog scale, three physical symptoms every evening during one menstrual cycle in conjunction with giving blood samples for progesterone and DOC measurements. DOC showed menstrual cycle-linked variation correlating with progesterone. There was no difference in plasma DOC concentrations between patients and controls. The symptoms reached a maximum 1-3 days before the onset of menstruation, with a delay of 3-6 days after the hormone peak. DOC was less strongly correlated with the symptoms than progesterone. These results do not support the hypothesis that DOC is involved in the etiology of physical symptoms in PMS or that physical and mental symptoms have separate etiologies.

Correlation of vascular endothelial growth factor content with recurrences, survival, and first relapse site in primary node-positive breast carcinoma after adjuvant treatment

PURPOSE

To determine the predictive value of vascular endothelial growth factor (VEGF) for relapse-free survival (RFS) and overall survival (OS) in primary node-positive breast cancer (NPBC) after adjuvant endocrine treatment or adjuvant chemotherapy.

MATERIALS AND METHODS

VEGF was quantitatively measured in tumor cytosols from 362 consecutive patients with primary NPBC using an enzyme immunoassay for human VEGF(165). Adjuvant treatment was given to all patients, either as endocrine therapy (n = 250) or chemotherapy (n = 112). The median follow-up time was 56 months.

RESULTS

Univariate analysis showed VEGF to be a significant predictor of RFS (P =.0289) and OS (P =.0004) in the total patient population and in patients who received adjuvant endocrine treatment (RFS, P =.0238; OS, P =.0121). In the group of patients who received adjuvant chemotherapy, no significant difference was seen in RFS, but a difference was seen in OS (P =.0235). Patients with bone recurrences tended to have lower VEGF expression (median, 2.17 pg/microg DNA) than patients with visceral metastasis (4.41 pg/microg), brain metastasis (8.29 pg/microg), or soft tissue recurrences (3.16 pg/microg). Multivariate analysis showed nodal status (P =.0004), estrogen receptor (ER) status (P <.0001), and tumor size (P =.0085) to be independent predictors of RFS. VEGF was found to be an independent predictor of OS (P =.0170; relative risk [RR] = 1.82), as were ER (P <.0001; RR = 5.19) and nodal status (P =.0002; RR = 2.58). For patients receiving adjuvant endocrine treatment, multivariate analysis showed VEGF content to be an independent predictor of OS (P =.0420; RR = 1.90) but not of RFS.

CONCLUSION

The results suggest that VEGF(165) content in tumor cytosols is a predictor of RFS and OS in primary NPBC. VEGF content might also predict outcome after adjuvant endocrine treatment, but further studies in a prospective setting with homologous treatments are required.

p53 and vascular-endothelial-growth-factor (VEGF) expression predicts outcome in 833 patients with primary breast carcinoma

The angiogenic factor vascular endothelial growth factor (VEGF) predicts outcome in primary breast carcinoma. Alteration of the p53 gene causes down-regulation of the expression of thrombospondin-1, a natural inhibitor of angiogenesis. This study was conducted to investigate the association between mutant p53 protein and VEGF expression, and the prognostic value of these factors. VEGF165 and p53 protein were measured in tumour cytosols by enzyme immunoassays. Recurrence-free survival (RFS) and overall survival (OS) were estimated in 833 consecutive patients, 485 node-negative (NNBC) and 348 node-positive (NPBC) with primary invasive breast cancer. A significant association was found between mutant p53 protein and VEGF expression. Univariate analysis showed both p53 and VEGF to be significant predictors of survival. Similar correlation was seen when p53 was combined with VEGF. Univariate analysis of NNBC showed significant prognostic value of p53 for OS, also when combined with VEGF expression; for NPBC, significant reductions in RFS and OS were seen for p53-positive patients, and these findings were enhanced when combined with VEGF, also in the sub-group receiving adjuvant endocrine treatment. Multivariate analysis showed both p53 and VEGF as independent predictors of OS in all groups. When the 2 factors were combined, an increased relative risk of 2.7 was seen for OS in the group with both p53 positivity and high VEGF content, as compared with 1.7 in the group with one risk factor. The results suggest an association between loss of wt-p53 and increased VEGF expression, indicating that angiogenic activity may depend, at least partly, on altered p53-protein function. Combination of these 2 biological markers appears to give additional predictive information of survival. A high-risk group of patients was associated with p53 positivity and higher VEGF content.

Vascular endothelial growth factor as prognostic factor in renal cell carcinoma

PURPOSE

Vascular endothelial growth factor (VEGF) has been recognized as an important constituent of vascularization and growth of solid tumors. Serum VEGF levels were evaluated and correlated to clinicopathologic findings and clinical outcome in patients with renal cell carcinoma (RCC).

MATERIALS AND METHODS

Serum samples were collected before surgery in 164 patients with RCC. Levels of VEGF165 protein in sera were measured using a quantitative ELISA. Univariate and multivariate analyses were performed.

RESULTS

The VEGF165 level in serum was significantly increased (p = 0.0001) in patients with RCC (median 343.4 pg./ml.) compared with the control patients (median 103.8 pg./ml.). The level of VEGF165 in serum correlated to clinical stage and histopathological grade. Patients with VEGF165 levels below median value had significantly longer survival time than patients with higher levels (p = 0.0001). This was also shown when VEGF165 was analyzed in univariate Cox regression (p = 0.0001). The impact of VEGF165 on survival was especially shown in patients having tumors with vein invasion (pT3b-c N0 M0) and in patients with clinical stages I - III (p = 0.0240 and p = 0.0023, respectively). When using multivariate analysis, only tumor stage and grade remained as independent prognostic variables.

CONCLUSIONS

In RCC, serum VEGF165 level was significantly correlated to tumor stage and grade. Increased levels were correlated to adverse survival. Although, VEGF did not remain as an independent prognostic factor in multivariate analysis the levels of VEGF165 in serum was found useful for the identification of patients with potentially progressive disease especially for those with vein invasion.