David Slosky

Bisphosphonates Inhibit Osteosarcoma‐Mediated Osteolysis Via Attenuation of Tumor Expression of MCP‐1 and RANKL

Osteosarcoma is the most common primary malignant tumor of bone and accounts for around 50% of all primary skeletal malignancies. In addition to novel chemotherapies, there is a need for adjuvant therapies designed to inhibit osteosarcoma proliferation and tumor‐induced osteolysis to attenuate tumor expansion and metastasis. As such, studies on the efficacy of bisphosphonates on human osteosarcoma are planned after feasibility studies determined that the bisphosphonate zoledronic acid (ZOL) can be safely combined with conventional chemotherapy. However, the molecular mechanisms responsible for, and means of inhibiting, osteosarcoma‐induced osteolysis are largely unknown. We establish that osteosarcoma growth directly correlates with tumor‐induced osteolysis and activation of osteoclasts in vivo. In vitro, tumor cells were determined to expresses surface, but not soluble, receptor activator of NF‐κB ligand (RANKL) and stimulated osteoclastogenesis in a manner directly proportional to their malignant potential. In addition, an aggressive osteosarcoma cell line was shown to secrete monocyte chemoattractant protein‐1 (MCP‐1), resulting in robust monocyte migration. Because MCP‐1 is a key cytokine for monocyte recruitment and surface‐bound RANKL strongly supports local osteoclastogenesis, we suggest that high levels of these signaling molecules are associated with the aggressive potential of osteosarcoma. Consistent with these findings, abundant expression of RANKL/MCP‐1 was observed in tumor in vivo, and MCP‐1 plasma levels strongly correlated with tumor progression and osteolysis. ZOL administration directly attenuates osteosarcoma production of RANKL/MCP‐1, reducing tumor‐induced bone destruction. In vivo, these findings also correlated with significant reduction in osteosarcoma growth. ZOL attenuates tumor‐induced osteolysis, not only through direct inhibition of osteoclasts, but also through direct actions on tumor expression of osteoclast activators. These data provide insight regarding the effect of ZOL on osteosarcoma essential for designing the planned upcoming prospective randomized trials to determine the efficacy of bisphosphonates on osteosarcoma in humans.

Recognizing and managing left ventricular dysfunction associated with therapeutic inhibition of the vascular endothelial growth factor signaling pathway.

Opinion statementTherapeutic inhibition of the vascular endothelial growth factor (VEGF) signaling pathway (VSP) is increasingly employed in the contemporary treatment of many cancer types. VSP inhibitors include the anti-VEGF monoclonal antibody (bevacizumab), soluble VEGF receptors (VEGF Trap), and small molecule tyrosine kinase inhibitors (TKIs) targeting the intracellular kinase domain of VEGF receptors. These agents are associated with cardiovascular toxicities such as hypertension, thrombosis, myocardial ischemia, and left ventricular (LV) dysfunction. Data on VSP inhibitor-associated LV dysfunction are largely limited to retrospective studies. Prospective studies are needed to establish the clinical significance of VSP inhibitor-associated LV dysfunction in the general population. Pre-clinical models of VSP inhibitor-associated LV dysfunction have identified mechanisms of cardiotoxicity and may improve our understanding of the pathophysiology underlying other cardiomyopathies. This review provides an overview of LV dysfunction that can occur in patients treated with VSP inhibitors. Potential strategies for clinical detection and management of this cardiotoxicity are explored, while acknowledging that currently available data specific to VSP-inhibitor LV dysfunction are limited. Avenues for future research are suggested.

Left Atrial Hypertension After Repeated Catheter Ablations for Atrial Fibrillation

To the Editor: Catheter ablation is an important treatment for recurrent, symptomatic atrial fibrillation (AF). The original procedure targeted focal triggers of AF arising from within the pulmonary veins (PVs). This technique generated minimal left atrial (LA) scar but was complicated by the

Autocrine VEGF/VEGFR1 Signaling in a Subpopulation of Cells Associates with Aggressive Osteosarcoma

Osteosarcoma is the most common primary bone malignancy and accounts for more than half of primary skeletal malignancies in children and young adults. Although vascular endothelial growth factor (VEGF) expression in osteosarcoma has been associated with poor outcome, its role in the pathogenesis of osteosarcoma remains controversial. Here, VEGF and VEGFR1 expression in both human and murine osteosarcoma cells associated with increasing malignant potential. Autocrine VEGF/VEGFR1 signaling resulted in constitutive activation of VEGFR1 in highly aggressive osteosarcoma cells. In addition, survival and proliferation of highly aggressive osteosarcoma cells was dependent on autocrine VEGF/R1 signaling in vitro. The effect of VEGFR1 expression on in vivo tumor growth and angiogenesis was evaluated by immunoselecting subpopulations of osteosarcoma cells that express high or low levels of VEGFR1. Cell enriched for high VEGFR1 expression showed increased VEGF production, tumor growth, tumor angiogenesis, and osteolysis in vivo. In addition, it was demonstrated that VEGF and VEGFR1 are coexpressed by a subset of tumor cells in human osteosarcoma, similar to what was observed in the murine osteosarcoma cells. These results suggest that autocrine VEGF/VEGFR1 signaling in a subpopulation of tumor cells plays a pivotal role in osteosarcoma progression. Implications: Aggressive osteosarcoma phenotypes are mediated by autocrine VEGF/VEGFR1 signaling and improved stratification measures and novel anti-angiogenic strategies may benefit this specific tumor type. Mol Cancer Res; 12(8); 1100–11. ©2014 AACR.

Pleiotropic effects of bisphosphonates on osteosarcoma

Osteosarcoma is the most common primary malignant tumor of bone and accounts for half of all primary skeletal malignancies in children and teenagers. The prognosis for patients who fail or progress on first-line chemotherapy protocols is poor, therefore, additional adjuvant therapeutic strategies are needed. A recent feasibility study has demonstrated that the nitrogen-containing bisphosphonate zoledronic acid (ZOL) can be combined safely with conventional chemotherapy. However, the pharmacodynamics of bisphosphonate therapy is not well characterized. Osteosarcoma is a highly angiogenic tumor. Recent reports of the anti-angiogenic effects of bisphosphonates prompted us to determine whether nitrogen-containing bisphosphonate (ZOL and alendronate) treatment attenuates osteosarcoma growth by inhibition of osteoclast activity, tumor-mediated angiogenesis, or direct inhibitory effects on osteosarcoma. Here, we demonstrate that bisphosphonates directly inhibit VEGFR2 expression in endothelial cells, as well as endothelial cell proliferation and migration. Additionally, bisphosphonates also decrease VEGF-A expression in osteosarcoma (K7M3) cells, resulting in reduced stimulation of endothelial cell migration in co-culture assays. ZOL also decreases VEGFR1 expression in aggressive osteosarcoma cell lines (K7M3, 143B) and induces apoptosis of these cells, but has negligible effects on less aggressive osteosarcoma cell lines (K12 and TE85). In vivo ZOL treatment results in significant reduction in osteosarcoma-initiated angiogenesis and tumor growth in a murine model of osteosarcoma. In conclusion, bisphosphonates have diverse growth inhibitory effects on osteosarcoma through: (1) activation of apoptosis and inhibition of cell proliferation, (2) inhibition of VEGF-A and VEGFR1 expression by tumor cells, (3) inhibition of tumor-induced angiogenesis, and (4) direct inhibitory actions on endothelial cells.

Cardiovascular Complications of Novel Multiple Myeloma Treatments.

Case presentation: A 75-year-old woman was referred to cardiology for optimization of cardiovascular risk factors before starting a new cancer treatment. She was diagnosed with IgG-κ multiple myeloma (MM) 2 years previously that progressed after her previous treatments. Her medical history also included type 2 diabetes mellitus, hypertension, and a remote history of deep vein thrombosis treated with a “blood thinner” for 6 months. Her hematologist has determined that a combination of carfilzomib, lenalidomide, and dexamethasone is the best treatment option for this patient but is concerned about the risk of cardiovascular complications from the new treatment and wants the patient to undergo evaluation by a cardiologist. MM is a plasma cell malignancy characterized by clonal proliferation of malignant plasma cells in the bone marrow microenvironment, monoclonal protein in the blood or urine, and associated organ dysfunction.1 MM accounts for 1% of all cancers and ≈13% of all hematologic malignancies. Approximately 86 000 new cases of MM occur annually worldwide and affect primarily older individuals with a median age of diagnosis of ≈70 years.2 Over the past few decades, overall survival has improved from an age-adjusted 5-year relative survival of 35.6% in 1998 to 2001 to 44% in 2006 to 2009.3 This improvement is due largely to increased use of autologous stem cell transplantation and the introduction of novel agents, including immunomodulatory drugs (IMiDs; ie, thalidomide [Thalomid], lenalinomide [Revlimid], and pomalidomide [Pomalyst]) and proteasome inhibitors (PIs; ie, bortezomib [Velcade] and carfilzomib [Kyprolis]). Figure 1 shows the milestones in MM treatment. Figure 1. Milestones in multiple myeloma (MM) treatment. The treatment paradigm of multiple myeloma treatment shifted with the introduction of 2 categories of novel treatment, immunomodulatory drugs (IMiDs) and proteasome inhibitors (PIs), which significantly improved survival in patients with MM. Cancer is associated with increased risk of venous thromboembolic …

MYOCARDITIS AND RHABDOMYOLYSIS INCIDENCE WITH IMMUNE CHECKPOINT INHIBITORS

Background: Immune checkpoint inhibitors have expanded treatment options for a number of cancer types by enhancing anti-tumor immune responses. Specifically, ipilimumab, an anti-cytotoxic T-lymphocyte associated antigen 4 (CTLA-4) antibody, and nivolumab, an anti-programmed death 1 (PD-1) antibody,

Outcomes from Autologous Hematopoietic Cell Transplantation versus Chemotherapy Alone for the Management of Light Chain Amyloidosis

Light chain amyloidosis (AL) results in tissue deposition of misfolded proteins, causing organ dysfunction. In an era of modern therapies, such as bortezomib, reassessment of the benefit of autologous hematopoietic cell transplantation (AHCT) should be considered. In this study, we compared outcomes between patients with AL receiving chemotherapy alone (CT) and those undergoing AHCT. Seventy-four patients with AL were analyzed retrospectively. Two cohorts of patients were studied, those receiving CT (n = 31) and those undergoing AHCT (n = 43). Of the 43 patients in the AHCT cohort, 29 received induction chemotherapy before AHCT, whereas 14 proceeded straight to AHCT without induction therapy. Compared with the CT cohort, patients in the AHCT cohort were younger and had higher ejection fractions, lower brain natriuretic peptide levels, and more severe proteinuria. The majority (87%) of patients in the CT cohort received bortezomib-based treatment. Transplantation-related mortality (TRM) was 7%. Patients receiving AHCT were more likely to achieve complete or very good partial response (P = .048). The median progression-free survival (PFS) and overall survival (OS) were superior in the AHCT cohort (not reached versus 9 months; P < .01 and 74 months versus 8 months; P = .03, respectively). Multivariable analysis demonstrated that improved PFS (hazard ratio, 3.86; 95% confidence interval [CI] 1.3 to 11.5; P = .02) and OS (hazard ratio, 5.6; 95% CI, 1.9 to 16; P < .001) were associated with use of AHCT compared with CT. Patients in the AHCT cohort had deeper and longer durations of response, with superior PFS and OS, compared with those in the CT cohort. Despite the limitations of this study, AHCT should be considered for eligible patients with AL at experienced transplantation centers that can offer this therapy with a low risk of TRM.

Novel pathologic scoring tools predict end-stage kidney disease in light chain (AL) amyloidosis

Abstract Background and objectives: Light chain (AL) amyloidosis frequently involves the kidney, causing significant morbidity and mortality. A pathologic scoring system with prognostic utility has not been developed. We hypothesized that the extent of amyloid deposition and degree of scarring injury on kidney biopsy, could provide prognostic value, and aimed to develop pathologic scoring tools based on these features. Methods: This is a case-control study of 39 patients treated for AL amyloidosis with biopsy-proven kidney involvement at a large academic medical center. Our novel scoring tools, composite scarring injury score (CSIS) and amyloid score (AS) were applied to each kidney biopsy. The primary outcome was progression to dialysis-dependent end-stage kidney disease (ESKD) using a 12-month landmark analysis. Results: At 12 months, nine patients had progressed to ESKD. Patients with an AS ≥7.5 had a significantly higher cumulative incidence of ESKD than those with AS <7.5 (p = .04, 95% CI 0.13–0.64). Conclusions: Using a 12-month landmark analysis, AS correlated with progression to ESKD. These data suggest that a kidney biopsy, in addition to providing diagnostic information, can be the basis for a pathologic scoring system with prognostic significance.

ISOLATED MYOCARDIAL RECURRENCE OF ACUTE MYELOGENOUS LEUKEMIA DIAGNOSED BY PERCUTANEOUS ENDOMYOCARDIAL BIOPSY

While primary malignancies of the heart are rare, secondary cardiac involvement in patients with cancer is relatively common and should be considered when these patients develop cardiovascular symptoms. A 63-year-old man presented with dyspnea on exertion. He had a history of myelodysplastic