endothelin-1 and Multiple-Myeloma

Skeletal-related complications occur commonly in many solid tumors including breast, prostate and lung cancer as well as multiple myeloma. In addition, malignancies and their associated treatment may result in bone loss or osteoporosis. This review will focus solely on recent data associated with metastatic bone disease with a focus on breast cancer, prostate cancer and multiple myeloma. Bone loss or osteoporosis associated with cancer will be covered in a separate article in this issue.. Recent progress in understanding the pathophysiology of bone metastases has pointed to several novel pathways: transforming growth factor beta; receptor activator of nuclear factor beta ligand and osteoprotegerin; and Wnt signaling pathways and associated factors such as dickkopf-1 and endothelin-1.. The identification of new pathways is important in metastatic bone disease from cancer and has allowed for the development of novel therapeutics aimed at preventing the devastating complications of bone metastases. Bisphosphonates remain the predominant therapy in use for the treatment and prevention of skeletal-related adverse effects from cancer.

Topics: Bone Density Conservation Agents; Bone Neoplasms; Breast Neoplasms; Diphosphonates; Endothelin-1; Female; Humans; Intercellular Signaling Peptides and Proteins; Male; Multiple Myeloma; Osteoprotegerin; Prostatic Neoplasms; RANK Ligand; Receptor Activator of Nuclear Factor-kappa B; Signal Transduction; Transforming Growth Factor beta; Wnt Proteins

High-dose cyclophosphamide is a well-known mobilization regimen in patients with multiple myeloma undergoing autologous hematopoietic stem cell transplantation. Highly differing rates of cardiac complications associated with high-dose cyclophosphamide have been reported. To date, no systematic clinical study has investigated high-dose cyclophosphamide mobilization regimens in multiple myeloma patients and evaluated its cardiotoxicity. We administered high-dose cyclophosphamide (4 g/m2) to 23 consecutive multiple myeloma patients and followed the patients for 15 days by serially measuring the cardiotoxicity biomarkers troponin I (TnI), brain natriuretic peptide (BNP), and endothelin 1 (ET-1). Systolic and diastolic left ventricular function was assessed by complete echocardiography before and at 6 to 8 weeks after the therapy. Patients younger than 55 years showed significant differences between basal TnI levels and TnI concentrations determined at 15 days after high-dose cyclophosphamide treatment (P = .028). Significant differences between basal BNP concentrations and BNP levels measured at 8 hours after high-dose cyclophosphamide treatment were found in the entire group of patients as well as in 2 subgroups, patients younger than 55 years and those older than 55 years (P <.0001, P <.001, and P = .001, respectively). ET-1 results for the entire group of patients showed a significant difference between baseline ET-1 values and ET-1 values determined 8 hours after high-dose cyclophosphamide administration (P = .004). Echocardiographic measurements revealed a barely nonsignificant decrease in cardiac output after high-dose cyclophosphamide infusion compared with pretreatment values (P = .06), a result in accord with echocardiographically detected increases in mild functional mitral regurgitation (P = .025). TnI levels at 15 days after the completion of treatment correlated with left ventricular diastolic dysfunction, as indicated by the s/d index (r = 0.61; P = .04). In conclusion, the significant neurohumoral activation of heart failure occurring after high-dose cyclophosphamide treatment is manifested by an increase in BNP and ET-1 levels, yet without concomitant cardiomyocyte necrosis. BNP levels and to a lesser extent ET-1 levels are much more sensitive indicators of myocardial injury than functional tests, such as echocardiography, whereas diastolic functional parameters are more sensitive predictors of early cyclophosphamide-induced cardiotoxicity. Mi

Topics: Adult; Aged; Biomarkers; Cyclophosphamide; Diastole; Echocardiography; Endothelin-1; Female; Graft Rejection; Heart Failure; Hematopoietic Stem Cell Transplantation; Humans; Immunosuppressive Agents; Male; Middle Aged; Multiple Myeloma; Natriuretic Peptide, Brain; Transplantation, Autologous; Troponin I

Topics: Bortezomib; Bosentan; Endothelin-1; Humans; Multiple Myeloma; Receptor, Endothelin A

Topics: Endothelin-1; Humans; Multiple Myeloma; Pyrimidines; Receptor, Endothelin A; Sulfonamides

New effective treatments are needed to improve outcomes for multiple myeloma (MM) patients. Receptors with restricted expression on plasma cells (PCs) represent attractive new therapeutic targets. The endothelin-1 (EDN1) axis, consisting of EDN1 acting through EDN-receptor A (EDNRA) and B (EDNRB), was previously shown to be overexpressed in several tumours, including MM. However, there is incomplete understanding of how EDN1 axis regulates MM growth and response to therapy. Besides EDNRA, the majority of MM cell lines and primary malignant PCs express high levels of EDNRB and release EDN1. Similarly, bone-marrow microenvironment cells also secrete EDN1. Investigating the extent of epigenetic dysregulation of EDNRB gene in MM, we found that hypermethylation of EDNRB promoter and subsequent down-regulation of EDNRB gene was observed in PCs or B lymphocytes from healthy donors compared to EDNRB-expressing malignant PCs. Pharmacological blockade with the dual EDN1 receptor antagonist bosentan decreased cell viability and MAPK activation of U266 and RPMI-8226 cells. Interestingly, the combination of bosentan and the proteasome inhibitor bortezomib, currently approved for MM treatment, resulted in synergistic cytotoxic effects. Overall, our data has uncovered EDN1-mediated autocrine and paracrine mechanisms that regulate malignant PCs growth and drug response, and support EDN1 receptors as new therapeutic targets in MM.

Topics: Adult; Aged; Aged, 80 and over; Autocrine Communication; Bortezomib; Bosentan; Cell Proliferation; Cell Survival; DNA Methylation; DNA, Neoplasm; Drug Synergism; Endothelin A Receptor Antagonists; Endothelin-1; Female; Gene Expression Regulation, Neoplastic; Humans; Male; Middle Aged; Molecular Targeted Therapy; Multiple Myeloma; Plasma Cells; Promoter Regions, Genetic; Receptor, Endothelin A; Sulfonamides; Tumor Cells, Cultured

Bortezomib (BTZ) is used for the treatment of multiple myeloma (MM). However, a significant proportion of patients may be refractory to the drug. This study aimed to investigate whether the endothelin (ET-1) axis may act as an escape mechanism to treatment with bortezomib in MM cells.. NCI-H929 and RPMI-8226 (human MM cell lines) were cultured with or without ET-1, BTZ, and inhibitors of the endothelin receptors. ET-1 levels were determined by ELISA, while the protein levels of its receptors and of the PI3K and MAPK pathways' components by western blot. Effects of ET-1 on cell proliferation were studied by MTT and on the ubiquitin proteasome pathway by assessing the chymotryptic activity of the 20S proteasome in cell lysates.. Endothelin receptors A and B (ETAR and ETBR, respectively) were found to be expressed in both cell lines, with the RPMI-8226 cells that are considered resistant to BTZ, expressing higher levels of ETBR and in addition secreting ET-1. Treatment of the NCI-H929 cells with ET-1 increased proliferation, while co-incubation of these cells with ET-1 and BTZ decreased BTZ efficacy with concomitant upregulation of 20S proteasomal activity. Si-RNA silencing or chemical blockade of ETBR abrogated the protective effects of ET-1. Finally, data suggest that the predominant signaling pathway involved in ET-1/ETBR-induced BTZ resistance in MM cells may be the MAPK pathway.. Our data suggest a possible role of the ET-1/ETBR axis in regulating the sensitivity of MM cells to BTZ. Thus, combining bortezomib with strategies to target the ET-1 axis could prove to be a novel promising therapeutic approach in MM.

Topics: Bortezomib; Cell Line, Tumor; Drug Resistance, Neoplasm; Endothelin A Receptor Antagonists; Endothelin-1; Humans; MAP Kinase Signaling System; Multiple Myeloma; Peptides, Cyclic; Phosphatidylinositol 3-Kinases; Proteasome Endopeptidase Complex; Receptor, Endothelin A; Receptor, Endothelin B; Ubiquitin

Tandem autologous hematopoetic stem cell transplantation (HSCT) is an effective treatment in patients with multiple myeloma (MM). Patients receive high-dose cyclophosphamide (CY) followed by two myeloablative dosages of melphalan (MEL). Cardiotoxicity treatment related data are scanty. In 30 patients with MM chemotherapy was followed by high-dose CY (cycle CY), and two autologous tandem HSCT treatments with MEL (cycles MEL I and MEL II). During each 15-day treatment troponin I (TnI), brain natriuretic peptide (BNP) and endothelin-1 (ET-1) were controlled at six time points. All patients underwent conventional and tissue Doppler echocardiography prior to CY therapy (Eho 0), before cycle MEL I (Eho 1), before cycle MEL II (Eho 2), and 3 months after the completion of therapy (Eho 3). None of the patients developed clinical signs of heart failure. The peak TnI concentrations were noted at days 8, 11, and 15 during all three chemotherapy cycles. During all three cycles there was a significant increase in baseline BNP concentrations and BNP levels measured at day 1 after treatment with CY and MEL (CY: P = 0.0001, MEL I: P = 0.001, MEL II: P = 0.001). The highest BNP concentration occurred during CY treatment (0.517 +/- 0.391 microg/L). During cycles MEL I and MEL II we noted the peak BNP concentrations at day 4 following chemotherapy (MEL I 0.376 +/- 0.418 microg/L; MEL II 0.363 +/- 0.379 microg/L). During all three cycles the highest ET-1 levels occurred at day 1 after chemotherapy (CY 1.146 +/- 1.313 ng/L; MEL I 1.054 +/- 2.242 ng/L; MEL II 0.618 +/- 0.539 ng/L). A significant increase in ET-1 concentrations relative to the basal values occurred only in cycle MEL II (P = 0.003). The duration of wave a in the Doppler pulmonary vein flow increased significantly (Eho 0/Eho 1: P = 0.008, Eho 0/Eho 3: P = 0.026). There was a significant decrease in the A/a ratio in flow velocities during chemotherapy (Eho 0/Eho 1: P = 0.002, Eho 0/Eho 3: P < 0.0001). Early diastolic tissue Doppler velocities (Em) decreased significantly during individual cycles of chemotherapy (P = 0.006). A significant post-treatment increase in the incidence of mitral regurgitation was observed (Eho 0/Eho 3: P = 0.003). Treatment of MM patients with tandem autologous HSCT is cardiotoxic. Our patients did not develop clinically overt heart failure or myocardial necrosis. Increased plasma levels of BNP and ET-1 were compatible with transient neurohormonal activation of heart failure. Doppler echo

Topics: Adult; Aged; Antineoplastic Agents, Alkylating; Antineoplastic Combined Chemotherapy Protocols; Biomarkers; Combined Modality Therapy; Cyclophosphamide; Echocardiography; Endothelin-1; Female; Heart Diseases; Hematopoietic Stem Cell Transplantation; Humans; Male; Melphalan; Middle Aged; Multiple Myeloma; Natriuretic Peptide, Brain; Troponin I

Vascular endothelial damage may play an important role in the pathophysiology of disseminated intravascular coagulation (DIC), a frequent complication of malignant neoplasms. It may mediate a variety of triggering events to initiate DIC and platelet aggregation, which in turn leads to additional endothelial destruction. If so, endothelin-1 (ET-1), the most potent vasoconstrictor of naturally occurring pressor substances known, may leak from injured endothelial cells and aggravate the disease process.. The study included 36 patients with various malignant neoplasms in whom DIC developed. The authors measured plasma levels of ET-1 and big ET-1, a precursor peptide of ET-1, in these patients and compared them with other laboratory abnormalities during the course of DIC.. Plasma ET-1 and big ET-1 levels were elevated in most patients with DIC. When compared with the results of other diagnostic tests, elevated plasma big ET-1 was the most frequently found abnormality associated with DIC. Elevation of plasma ET-1 and big ET-1 levels was closely related to the initiation and progression of DIC and provided a higher degree of sensitivity and specificity than did other indicators in assessing patients with cancer and DIC.. Vascular endothelial damage with the resultant increases in plasma ET-1 and big ET-1 levels is universally associated with DIC caused by malignancy. Excessive secretion or leakage of ET-1 and big ET-1 from injured endothelial cells may cause vasospasm and aggravate the DIC process by facilitating the formation of intravascular microthrombi, ultimately leading to ischemic end-organ dysfunction. Plasma ET-1 and big ET-1 are sensitive and specific markers for vascular endothelial injury in DIC.

Topics: Adult; Aged; Aged, 80 and over; Antithrombin III; Disseminated Intravascular Coagulation; Endothelin-1; Endothelins; Female; Fibrin Fibrinogen Degradation Products; Fibrinogen; Humans; Lymphoma; Male; Middle Aged; Multiple Myeloma; Neoplasm Metastasis; Neoplasms; Platelet Count; Protein Precursors; Prothrombin Time