Human small cell lung cancer cells produce brain natriuretic peptide

Significance of N-terminal pro-B-type natriuretic peptide levels in lung cancer

High blood levels of N-terminal pro-brain natriuretic peptide (NT-proBNP) have been shown in various malignancies. In lung cancer, the importance of NT-proBNP is not clear. In this study, we aimed to investigate the significance of the correlation of NT-proBNP levels in lung cancer with tumor stage, tumor diameter, histopathology, and specific sites of mediastinal metastasis: lymphadenopathy; pericardial, cardiac, major vessel, other mediastinal organ or lymphatic involvement/invasion. A total of 105 lung cancer and 120 control patients (chronic obstructive lung disease, interstitial lung disease, pulmonary thromboembolism, and pneumonia; 30/subgroup) with measured NT-proBNP levels were included retrospectively. Demographics, comorbidities, and echocardiographic findings in all patients, as well as histologic subtype, diameter, stage, and radiologic and/or pathologic mediastinal involvement/invasion of the tumor to the mediastinum in patients with lung cancer, were studied with regards to blood NT-proBNP levels. When lung cancer and control groups were compared globally or as subgroups with comorbidities, NT-proBNP levels did not show meaningful differences. However, NT-proBNP levels were determined to be 249 pg/mL and 88 pg/mL in lung cancer (n=68) and control subgroups (n=58) without comorbidities, respectively (p=0.001). Among lung cancer patients without comorbidities and those with cardiac, pericardial, major vascular, or other mediastinal involvement/invasion (lymphadenopathy, lymphatic, or other organ invasion) (n=27), the NT-proBNP level was 303 pg/mL, whereas it was 166 pg/mL in those without these mediastinal invasions (n=41) (p=0.031). There is a need for much larger, randomized studies to obtain evidence for the potential role of NT-proBNP as a helpful diagnostic biomarker for lung cancer. Clinical suspicion of malignancy may be posed if high NT-proBNP levels cannot be explained by all other risk factors and disorders or diseases. Furthermore, pericardial, cardiac, major vessel, or other mediastinal invasion/involvement should be sought when high NT-proBNP levels are determined in lung cancer patients without any comorbidities or risk factors for high NT-proBNP levels.

Therapy-naïve malignancy causes cardiovascular disease: a state-of-the-art cardio-oncology perspective

Cardiovascular disease (CVD) and cancer are the leading causes of mortality worldwide. Although generally thought of as distinct diseases, the intersectional overlap between CVD and cancer is increasingly evident in both causal and mechanistic relationships. The field of cardio-oncology is largely focused on the cardiotoxic effects of cancer therapies (e.g., chemotherapy, radiation). Furthermore, the cumulative effects of cardiotoxic therapy exposure and the prevalence of CVD risk factors in patients with cancer lead to long-term morbidity and poor quality of life in this patient population, even when patients are cancer-free. Evidence from patients with cancer and animal models demonstrates that the presence of malignancy itself, independent of cardiotoxic therapy exposure or CVD risk factors, negatively impacts cardiac structure and function. As such, the primary focus of this review is the cardiac pathophysiological and molecular features of therapy-naïve cancer. We also summarize the strengths and limitations of preclinical cancer models for cardio-oncology research and discuss therapeutic strategies that have been tested experimentally for the treatment of cancer-induced cardiac atrophy and dysfunction. Finally, we explore an adjacent area of interest, called "reverse cardio-oncology," where the sequelae of heart failure augment cancer progression. Here, we emphasize the cross-disease communication between malignancy and the injured heart and discuss the importance of chronic low-grade inflammation and endocrine factors in the progression of both diseases.

Heart failure pharmacotherapy and cancer: pathways and pre-clinical/clinical evidence

Heart failure (HF) patients have a significantly higher risk of new-onset cancer and cancer-associated mortality, compared to subjects free of HF. While both the prevention and treatment of new-onset HF in patients with cancer have been investigated extensively, less is known about the prevention and treatment of new-onset cancer in patients with HF, and whether and how guideline-directed medical therapy (GDMT) for HF should be modified when cancer is diagnosed in HF patients. The purpose of this review is to elaborate and discuss the effects of pillar HF pharmacotherapies, as well as digoxin and diuretics on cancer, and to identify areas for further research and novel therapeutic strategies. To this end, in this review, (i) proposed effects and mechanisms of action of guideline-directed HF drugs on cancer derived from pre-clinical data will be described, (ii) the evidence from both observational studies and randomized controlled trials on the effects of guideline-directed medical therapy on cancer incidence and cancer-related outcomes, as synthetized by meta-analyses will be reviewed, and (iii) considerations for future pre-clinical and clinical investigations will be provided.

Cardiovascular Biomarkers in Cardio-Oncology: Antineoplastic Drug Cardiotoxicity and Beyond

Serum biomarkers represent a reproducible, sensitive, minimally invasive and inexpensive method to explore possible adverse cardiovascular effects of antineoplastic treatments. They are useful tools in risk stratification, the early detection of cardiotoxicity and the follow-up and prognostic assessment of cancer patients. In this literature review, we aim at describing the current state of knowledge on the meaning and the usefulness of cardiovascular biomarkers in patients with cancer; analyzing the intricate relationship between cancer and cardiovascular disease (especially HF) and how this affects cardiovascular and tumor biomarkers; exploring the role of cardiovascular biomarkers in the risk stratification and in the identification of chemotherapy-induced cardiotoxicity; and providing a summary of the novel potential biomarkers in this clinical setting.

Pleural Fluid-to-Blood BNP Ratio May Contribute to Prognosis in Malignant Pleural Mesothelioma

BACKGROUND

Brain natriuretic peptide (BNP) seems to be produced from malignant mesothelial cells other than cardiomyocytes. We aimed to evaluate whether an increased pleural fluid-to-blood BNP ratio in patients with malignant pleural mesothelioma (MPM) could facilitate prognosis beyond diagnosis.

MATERIALS AND METHODS

Patients with MPM were included (observational study). One- and two-year survival and factors affecting it were tested. To evaluate the prognostic significance of the natriuretic peptide precursor B (NPPB) gene expression in MPM, we constructed a survival curve from data derived from The Cancer Genome Atlas.

RESULTS

Nineteen consecutive patients with MPM were included (age: 67 (61, 80), male 78.9%). One- and two-year survival were 52.6% and 31.6%, respectively. Age, performance status, and the other variables tested did not differ between survivors and non-survivors. Non-survivors presented higher pleural fluid BNP in two years (699 (210, 5000) vs. 379.5 (5, 567), p = 0.036) and BNP ratios than survivors (1-year: 28.75 (4.05, 150.24) vs. 3.49 (0.3, 26) p = 0.001, 2-years: 22.8 (2.42, 150.24) vs. 3.49 (0.3, 7.76), p = 0.001). One- and two-year survival rates in patients with BNP ratios above/equal to the median value (8.82) were 20% and 0%, and 88.9% and 66.7%, respectively, in patients with BNP ratios below 8.82 (p = 0.006 and p = 0.002, respectively). MPM patients with low NPPB expression presented significantly higher survival rates compared to patients with higher expressions (p = 0.032).

CONCLUSION

A high pleural fluid/blood BNP ratio, an easily performed in everyday practice, costless biomarker seems to predict poorer survival better than the commonly reported prognostic factors in MPM.

Impact of socioeconomic and cardiovascular risk factors on the effect of genetic variants associated with NT-proBNP

N-terminal prohormone of brain natriuretic peptide (NT-proBNP) is an established biomarker for diagnosis of heart failure. The study aims to explore whether known cardiovascular risk factors, including education and income as indicators of socioeconomic position (SEP), may interact with the genetic effect of NT-proBNP-related single nucleotide polymorphisms (SNP) to influence plasma levels of NT-proBNP in a population-based study sample. Information on effect alleles of three SNPs previously reported to be related to NT-proBNP was combined individually for 4,520 participants of the Heinz Nixdorf Recall Study to calculate a genetic risk allele sum score (GRS_NT-proBNP). Linear Regression models were used to examine the association of cardiovascular risk factors and GRS_NT-proBNP with log-transformed NT-proBNP levels, as well as cardiovascular risk factor by GRS_NT-proBNP interactions. The GRS_NT-proBNP was associated with NT-proBNP showing 1.13-fold (95% CI 1.10–1.16) higher plasma levels per additional effect allele. Interaction terms included in the regression models gave some indication for interaction of the GRS_NT-proBNP with the SEP indicator income as well as with C-reactive protein. In regression models stratified by income quartiles the strongest genetic effect was observed in the third income quartile showing 1.18-fold (95% CI 1.12–1.25) higher average NT-proBNP levels per additional allele compared to the lowest income quartile with 1.08-fold (95% CI 1.01–1.15) higher NT-proBNP levels. The results of the present study indicate that genetic effects of NT-proBNP increasing alleles are stronger in higher SEP groups. This may be due to a stronger influence of non-genetic cardiovascular risk on NT-proBNP in low SEP groups.

Bidirectional Relationship Between Cancer and Heart Failure: Insights on Circulating Biomarkers

Cancer and heart failure are the two leading causes of death in developed countries. These two apparently distinct clinical entities share similar risk factors, symptoms, and pathophysiological mechanisms (inflammation, metabolic disturbances, neuro-hormonal and immune system activation, and endothelial dysfunction). Beyond the well-known cardiotoxic effects of oncological therapies, cancer and heart failure are thought to be tied by a bidirectional relationship, where one disease favors the other and vice versa. In this context, biomarkers represent a simple, reproducible, sensitive and cost-effective method to explore such relationship. In this review, we recapitulate the evidence on cardiovascular and oncological biomarkers in the field of cardioncology, focusing on their role in treatment-naïve cancer patients. Cardioncological biomarkers are useful tools in risk stratification, early detection of cardiotoxicity, follow-up, and prognostic assessment. Intriguingly, these biomarkers might contribute to better understand the common pathophysiology of cancer and heart failure, thus allowing the implementation of preventive and treatment strategies in cardioncological patients

N-Terminal Pro-Brain Natriuretic Peptide Plasma Levels Are Associated with Intermediate-Term Follow-Up Cancer in Coronary Patients

N-terminal pro-brain natriuretic peptide (NT-proBNP) plasma levels are increased in patients with cancer. In this paper, we test whether NT-proBNP may identify patients who are going to receive a future cancer diagnosis (CD) in the intermediate-term follow-up. We studied 962 patients with stable coronary artery disease and free of cancer and heart failure at baseline. This sample represents a re-analysis of a previous work expanding the sample size and the follow-up. NT-proBNP, galectin-3, monocyte chemoattractant protein-1, high-sensitivity C-reactive protein, high-sensitivity cardiac troponin I (hsTnI), and calcidiol (vitamin D) plasma levels were assessed. The primary outcome was new CD. After 5.40 (2.81–6.94) years of follow-up, 59 patients received a CD. NT-proBNP [HR 1.036 CI (1.015–1.056) per increase in 100 pg/mL; p = 0.001], previous atrial fibrillation (HR 3.140 CI (1.196–8.243); p = 0.020), and absence of previous heart failure (HR 0.067 CI (0.006–0.802); p = 0.033) were independent predictors of receiving a CD in the first three years of follow-up. None of the variables analyzed predicted a CD beyond this time. The number of patients developing heart failure during follow-up was 0 (0.0%) in patients receiving CD in the first three years of follow-up, 2 (6.9%) in those receiving a CD diagnosis beyond this time, and 40 (4.4%) in patients not developing cancer (p = 0.216). These numbers suggest that future heart failure was not a confounding factor. In patients with coronary artery disease, NT-proBNP was an independent predictor of CD in the first three years of follow-up but not later, suggesting that it could be detecting subclinical undiagnosed cancers.

Subclinical cardiac damage in cancer patients before chemotherapy

Cancer and cardiovascular diseases, including heart failure (HF), are the main causes of death in Western countries. Several anticancer drugs and radiotherapy have adverse effects on the cardiovascular system, promoting left ventricular dysfunction and ultimately HF. Nonetheless, the relationship between cancer and HF is likely not unidirectional. Indeed, cancer and HF share common risk factors, and both have a bidirectional relationship with systemic inflammation, metabolic disturbances, and neurohormonal and immune activation. Few studies have assessed the impact of untreated cancer on the heart. The presence of an active cancer has been associated with elevated cardiac biomarkers, an initial impairment of left ventricular structure and function, autonomic dysfunction, and reduced exercise tolerance. In turn, these conditions might increase the risk of cardiac damage from chemotherapy and radiotherapy. HF drugs such as beta-blockers or inhibitors of the renin–angiotensin–aldosterone system might exert a protective effect on the heart even before the start of cancer therapies. In this review, we recapitulate the evidence of cardiac involvement in cancer patients naïve from chemotherapy and radiotherapy and no history of cardiac disease. We also focus on the perspectives for an early diagnosis and treatment to prevent the progression to cardiac dysfunction and clinical HF, and the potential benefits of cardioactive drugs on cancer progression.

Interventions in the B-type natriuretic peptide signalling pathway as a means of controlling chronic itch

Chronic itch poses major health care and economic burdens worldwide. In 2013, B-type natriuretic peptide (BNP) was identified as an itch-selective neuropeptide and shown to be both necessary and sufficient to produce itch behaviour in mice. Since then, mechanistic studies of itch have increased, not only at central levels of the spinal relay of itch signalling but also in the periphery and skin. In this review, we have critically analysed recent findings from complementary pharmacological and physiological approaches, combined with genetic strategies to examine the role of BNP in itch transduction and modulation of other pruritic proteins. Additionally, potential targets and possible strategies against BNP signalling are discussed for developing novel therapeutics in itch. Overall, we aim to provide insights into drug development by altering BNP signalling to modulate disease symptoms in chronic itch, including conditions for which no approved treatment exists.

Expression patterns of natriuretic peptides in pre-hibernating and hibernating anatolian ground squirrel (Spermophilus xanthoprymnus) lung

Anatolian ground squirrel (Spermophilus xanthoprymnus) is a true hibernator. This animal transiently reduces pulmonary function during hibernation. Continuance of pulmonary function is very important to survive ground squirrels during the hibernation. Natriuretic peptides may be key players in the modulation of pulmonary hemostasis. However, NPs' role in pulmonary function during hibernation remains unclear. We aimed to investigate the localization and distribution of atrial natriuretic peptide (ANP), brain natriuretic peptide (BNP) and C-type natriuretic peptide (CNP) in squirrel lungs during pre-hibernation and hibernation periods using immunohistochemistry. Our immunohistochemical data indicate that ANP, BNP, and CNP were produced by the mucosal epithelium of terminal and respiratory bronchioles, smooth muscle cells in the lamina propria of terminal bronchioles and vascular smooth muscle cells, alveolar type II cells, and macrophages. ANP immunoreactivity was weaker than BNP and CNP immunoreactivities in these cells. The results also demonstrate that the number of ANP, BNP and CNP positive alveolar type II cells tended to increase, although statistically non-significant, during the hibernation period, but the expression of NPs in other pulmonary cells is unaffected by hibernation. This study firstly investigates ANP, BNP and CNP distribution in the Anatolian ground squirrel lung. However, further studies are required to dissect their functional roles during the hibernation.

Exercise Training Impacts Cardiac Mitochondrial Proteome Remodeling in Murine Urothelial Carcinoma

Cardiac dysfunction secondary to cancer may exert a negative impact in patients’ tolerance to therapeutics, quality of life, and survival. The aim of this study was to evaluate the potential therapeutic effect of exercise training on the heart in the setting of cancer, after diagnosis. Thus, the molecular pathways harbored in heart mitochondria from a murine model of chemically-induced urothelial carcinoma submitted to 8-weeks of high intensity treadmill exercise were characterized using mass spectrometry-based proteomics. Data highlight the protective effects of high intensity exercise training in preventing left ventricle diastolic dysfunction, fibrosis, and structural derangement observed in tumor-bearing mice. At the mitochondrial level, exercise training counteracted the lower ability to produce ATP observed in the heart of animals with urothelial carcinoma and induced the up-regulation of fatty acid oxidation and down-regulation of the biological process “cardiac morphogenesis”. Taken together, our data support the prescription of exercise training after cancer diagnosis for the management of disease-related cardiac dysfunction.

Elevated serum levels of cardiovascular biomarkers are associated with progression of renal cancer

Objective

Renal cell carcinoma (RCC) is a hypervascular tumour due to high constitutive production of vascular endothelial growth factor (VEGF), which is activated by hypoxia-inducible factor (HIF). Elevated levels of cardiovascular peptides, including brain natriuretic peptide (BNP), have been reported in patients with cancer, regardless of whether they have overt cardiovascular disease. Furthermore, it has been demonstrated that hypoxia stimulates BNP production by an HIF-dependent manner. However, the clinical implications of such cardiovascular peptides in patients with RCC have not been assessed.

Methods

In patients with clear cell RCC who underwent nephrectomy, we investigated the relationship between the serum level of BNP or N-terminal pro-BNP (NT-proBNP) and various clinicopathological characteristics, including serum VEGF and expression of BNP and HIF-2 alpha in the primary tumour.

Results

Elevated preoperative serum levels of BNP, NT-proBNP and VEGF, as well as increased tumour expression of HIF-2 alpha, were associated with a worse performance status, local invasion, distant metastasis and shorter overall survival. HIF-2 alpha expression showed a positive correlation with the preoperative serum VEGF level, while there was no relation between the serum levels of BNP/NT-proBNP and VEGF or tumour expression of HIF-2 alpha. BNP expression was very low in both tumour tissues and normal kidney tissues. Serum levels of BNP, NT-proBNP and VEGF all decreased significantly after nephrectomy.

Conclusions

Our findings suggested that the preoperative serum levels of BNP and NT-proBNP are markers of tumour progression, as well as indicators of subclinical functional and structural myocardial damage in patients with advanced RCC.

N-Terminal Pro-Brain Natriuretic Peptide Is Associated with a Future Diagnosis of Cancer in Patients with Coronary Artery Disease

Objective

Several papers have reported elevated plasma levels of natriuretic peptides in patients with a previous diagnosis of cancer. We have explored whether N-terminal pro-brain natriuretic peptide (NT-proBNP) plasma levels predict a future diagnosis of cancer in patients with coronary artery disease (CAD).

Methods

We studied 699 patients with CAD free of cancer. At baseline, NT-proBNP, galectin-3, monocyte chemoattractant protein-1, soluble tumor necrosis factor-like weak inducer of apoptosis, high-sensitivity C-reactive protein, and high-sensitivity cardiac troponin I plasma levels were assessed. The primary outcome was new cancer diagnosis. The secondary outcome was cancer diagnosis, heart failure requiring hospitalization, or death.

Results

After 2.15±0.98 years of follow-up, 24 patients developed cancer. They were older (68.5 [61.5, 75.8] vs 60.0 [52.0, 72.0] years; p=0.011), had higher NT-proBNP (302.0 [134.8, 919.8] vs 165.5 [87.4, 407.5] pg/ml; p=0.040) and high-sensitivity C-reactive protein (3.27 [1.33, 5.94] vs 1.92 [0.83, 4.00] mg/L; p=0.030), and lower triglyceride (92.5 [70.5, 132.8] vs 112.0 [82.0, 157.0] mg/dl; p=0.044) plasma levels than those without cancer. NT-proBNP (Hazard Ratio [HR]=1.030; 95% Confidence Interval [CI]=1.008-1.053; p=0.007) and triglyceride levels (HR=0.987; 95%CI=0.975-0.998; p=0.024) were independent predictors of a new cancer diagnosis (multivariate Cox regression analysis). When patients in whom the suspicion of cancer appeared in the first one-hundred days after blood extraction were excluded, NT-proBNP was the only predictor of cancer (HR=1.061; 95%CI=1.034-1.088; p<0.001). NT-proBNP was an independent predictor of cancer, heart failure, or death (HR=1.038; 95%CI=1.023-1.052; p<0.001) along with age, and use of insulin and acenocumarol.

Conclusions

NT-proBNP is an independent predictor of malignancies in patients with CAD. New studies in large populations are needed to confirm these findings.

What is causing extremely elevated amino terminal brain natriuretic peptide in cancer patients?

High levels of B-type natriuretic peptide in cancer patients are poorly studied. Previously published data suggest that they are not related to fluid overload and are encountered mostly in solid cancers. The authors investigated the distribution of amino terminal pro-brain natriuretic peptide (NT-proBNP) between hematologic and solid organ malignancies and the relationship of NT-proBNP with volume status in oncologic patients. A total of 145 consecutive patients with at least one occurrence of NT-proBNP exceeding the upper normal range 10-fold were identified. The authors retrospectively reviewed their records including clinical, laboratory, and radiological data and echocardiograms. More than 70% of patients had hematologic malignancies. Patients with NT-proBNP >50,000 pg/mL had only hematologic malignancies, primarily multiple myeloma. There was no association between M-spike proteins and NT-proBNP. About 80% of patients had signs of fluid overload. The magnitude of NT-proBNP elevation was similar between those with and without heart failure or volume overload, as well as with solid cancers vs hematologic malignancies. Contrary to prior reports, it was found that very high NT-proBNP in cancer patients is usually encountered in the context of fluid overload and most often in hematologic malignancies.

Preparation and Characterization of Molecularly Imprinted Polymeric Nanoparticles for Atrial Natriuretic Peptide (ANP)

Natriuretic peptide receptor A (NPRA), the receptor for the cardiac hormone atrial natriuretic peptide (ANP), is expressed abundantly on cancer cells and disruption of ANP-NPRA signaling inhibits tumor burden and metastasis. Since antagonists of NPRA signaling have not provided reproducible results, we reasoned that a synthetic neutralizing antibody to ANP, which has high selectivity and affinity for ANP, could be used to regulate ANP levels and attenuate NPRA signaling. In this study, we prepared molecularly imprinted polymer nanoparticles (MIPNPs) for ANP using a short peptide of ANP as the template and determined their binding affinity and selectivity. The MIPNPs were prepared by precipitation polymerization using NH2-SLRRSS-CONH2, which is a short peptide from ANP as template, methacrylic acid (MAA) and N-isopropylacrylamide (NIPAm) as functional monomers, bis-acrylamide (BIS) as crosslinker. The average diameter of MIPNPs and non-imprinted nanoparticles (NIPNPs) in water is 215.8 ±4.6 nm and 197.7±3.1 nm respectively. The binding isotherm analysis showed that MIPNPs have a much higher binding affinity for template peptide and ANP than NIPNPs. Scatchard analysis gave an equilibrium dissociation constant, Kd of 7.3 μM with a binding capacity 106.7 μmol/g for template peptide and Kd of 7.9 μM with a binding capacity of 36.0 μmol/g for ANP. Measurements of binding kinetics revealed that MIPNPs reach protein adsorption equilibrium in 30 min. MIPNPs found to have high specificity for ANP with little affinity for BSA or scrambled ANP peptide. MIPNPs also recognized and adsorbed ANP in cell culture media spiked with ANP and human plasma. Taken together, these results indicate that MIPNPs have high affinity and selectivity for ANP and can be used as a synthetic antibody for modulating ANP-NPRA signaling in cancers.

Brain natriuretic peptide measurement in pulmonary medicine

Serum levels of natriuretic peptides are well established as important biomarkers in patients with cardiac disease. Less attention has been placed on the role of natriuretic peptides in patients with pulmonary conditions. In several well-defined groups of patients with pulmonary disease natriuretic peptides provide the clinician with clinically valuable information. A limitation of the interpretation of natriuretic peptides in pulmonary disease is the confounding effect of concurrent conditions such as heart failure, hypoxia, sepsis and renal failure. The present paper reviews the role of natriuretic peptides for diagnosis, risk stratification and prognosis of several pulmonary disorders.

Natriuretic peptide receptor a as a novel anticancer target

The receptor for atrial natriuretic peptide (ANP), natriuretic peptide receptor A (NPRA), is expressed in cancer cells, and natriuretic peptides have been implicated in cancers. However, the direct role of NPRA signaling in tumorigenesis remains elusive. Here, we report that NPRA expression and signaling is important for tumor growth. NPRA-deficient mice showed significantly reduced antigen-induced pulmonary inflammation. NPRA deficiency also substantially protected C57BL/6 mice from lung, skin, and ovarian cancers. Furthermore, a nanoparticle-formulated interfering RNA for NPRA attenuated B16 melanoma tumors in mice. Ectopic expression of a plasmid encoding NP73-102, the NH(2)-terminal peptide of the ANP prohormone, which down-regulates NPRA expression, also suppressed lung metastasis of A549 cells in nude mice and tumorigenesis of Line 1 cells in immunocompetent BALB/c mice. The antitumor activity of NP73-102 was in part attributed to apoptosis of tumor cells. Western blot and immunohistochemistry staining indicated that the transcription factor, nuclear factor-kappaB, was inactivated, whereas the level of tumor suppressor retinoblastoma protein was up-regulated in the lungs of NPRA-deficient mice. Furthermore, expression of vascular endothelial growth factor was down-regulated in the lungs of NPRA-deficient mice compared with that in wild-type mice. These results suggest that NPRA is involved in tumor angiogenesis and represents a new target for cancer therapy.

Cancer Patients With Markedly Elevated B-Type Natriuretic Peptide May Not Have Volume Overload

OBJECTIVES

Elevated B-type natriuretic peptide (BNP) levels are established as a marker for volume overload and left ventricular (LV) dysfunction in patients with predominately cardiac diseases. Little is known about markedly elevated BNP values in patients with multiple comorbidities.

METHODS

A total of 99 patients, admitted to M. D. Anderson Cancer Center, were identified as having a BNP value >1000 pg/mL during the year 2003. Clinical characteristics, including the presence of volume overload and sepsis, as well as echocardiographic parameters were measured. Principal outcome was defined as 30-day mortality.

RESULTS

The median BNP (pg/mL) of the group was 2270 (range, 1010-5000), and there was no association between elevation of the BNP level and the presence of volume overload or LV dysfunction (P = not significant). The large majority of patients (n = 71, 72%) had no volume overload and normal or nearly normal LV function (n = 60, 61%). A majority were also identified as having sepsis (n = 52, 53%). There was no echocardiographic parameter that consistently correlated with BNP levels or volume overload. There was a highly significant association with sepsis and mortality in patients with markedly elevated BNP values, and this conferred a 2.71-fold increased risk of mortality.

CONCLUSIONS

In patients admitted with multiple comorbidities and markedly elevated BNP values, there is no significant association with clinical evidence of volume overload or LV dysfunction. An elevated BNP level in patients with sepsis was significantly associated with mortality.

B-type natriuretic peptide concentrations and myocardial dysfunction in critical illness

B-type natriuretic peptide (BNP) is the first biomarker of proven value in screening for left ventricular dysfunction. The availability of point-of-care testing has escalated clinical interest and the resultant research is defining a role for BNP in the investigation and treatment of critically ill patients. This review was undertaken with the aim of collecting and assimilating current evidence regarding the use of BNP assay in the evaluation of myocardial dysfunction in critically ill humans. The information is presented in a format based upon organ system and disease category. BNP assay has been studied in a spectrum of clinical conditions ranging from acute dyspnoea to subarachnoid haemorrhage. Its role in diagnosis, assessment of disease severity, risk stratification and prognostic evaluation of cardiac dysfunction appears promising, but requires further elaboration. The heterogeneity of the critically ill population appears to warrant a range of cut-off values. Research addressing progressive changes in BNP concentration is hindered by infrequent assay and appears unlikely to reflect the critically ill patient's rapidly changing haemodynamics. Multi-marker strategies may prove valuable in prognostication and evaluation of therapy in a greater variety of illnesses. Scant data exist regarding the use of BNP assay to alter therapy or outcome. It appears that BNP assay offers complementary information to conventional approaches for the evaluation of cardiac dysfunction. Continued research should augment the validity of BNP assay in the evaluation of myocardial function in patients with life-threatening illness.

B-type natriuretic peptide: Issues for the intensivist and pulmonologist

OBJECTIVE

B-type natriuretic peptide (BNP) and N-terminal pro-BNP (NT-proBNP), although promising as biomarkers for heart failure, are affected by multiple confounders. The purpose of this article is to review the literature on the utility of BNP and NT-proBNP as biomarkers, with a focus on their role in critical illness and pulmonary diseases.

DATA SOURCE

Published articles on BNP and NT-proBNP.

DATA ANALYSIS

Multiple disorders in the intensive care unit cause elevated BNP and NT-proBNP levels, including cardiac diseases, shock, pulmonary hypertension, acute respiratory distress syndrome, acute pulmonary embolism, chronic obstructive pulmonary disease, renal failure, and other conditions.

CONCLUSIONS

Intensivists and pulmonologists should understand that BNP and NT-proBNP levels might be raised to different degrees not only in heart failure but also in critical illness and various pulmonary diseases; in these situations, BNP and NT-proBNP may also serve as markers of severity and prognosis.

Overexpression of a set of genes, including WISP-1, common to pulmonary metastases of both mouse D122 Lewis lung carcinoma and B16-F10.9 melanoma cell lines

Despite advances in the management of solid tumours, the development of metastases continues to be the most significant problem and cause of death for cancer patients. To define genetic determinants of pulmonary metastases, we have applied oligonucleotide microarrays to established murine models of highly metastatic D122 Lewis lung carcinoma and B16-F10.9 melanoma cell lines. These models are characterised by primary subcutaneous growth in C57BL/6J mice, a period of minimal residual disease and spontaneous pulmonary metastases. Microarray analysis defined seven genes, namely - arginase, brain natriuretic peptide (BNP), interleukin-1 alpha (IL-1 alpha), plasminogen activator inhibitor-2 (PAI-2), surfactant protein C (SP-C), uteroglobin (UG) and wnt-1-induced secreted protein-1 (WISP-1), which were consistently elevated in pulmonary metastases compared to the primary tumour of both D122 and B16-F10.9 models. Previous studies demonstrated that two of these seven genes, IL-1 alpha and PAI-2, are involved in the metastatic process. The results obtained by the microarrays were confirmed by real-time quantitative PCR, for three chosen genes - PAI-2, WISP-1 and UG. Our approach aimed to identify genes essential for the metastatic process in general and for pulmonary metastases specifically. Further research should address the precise role of these genes in the metastasising process to the lungs and test if they could be used as targets for future therapies.

Human bone marrow endothelial cells: a new identified source of B-type natriuretic peptide

B-type natriuretic peptide (BNP) is a hormone mainly secreted by cardiac ventricle myocytes and which is increased in cardiac diseases. Moreover, BNP expression has been shown in various cell/tissue types. Six different human endothelial cell (EC) culture models arising from macro and microcirculation either primary cultures or cell lines were cultured and screened for BNP presence and secretion. All cell types expressed BNP mRNA while only the ECs arising from bone marrow stromal compartment secreted high amounts of BNP protein. This report is the first to identify ECs as a new source of BNP. However, BNP secretion is limited to a particular EC type.