Stuart L. Cramer

Gorham-Stout Disease Successfully Treated With Sirolimus and Zoledronic Acid Therapy.

Gorham-Stout disease is a life-threatening disorder often manifested by lymphatic malformation and osteolysis. Unfortunately, available therapies are not uniformly effective and often carry substantial morbidity. We report an 18-year-old male with Gorham-Stout disease manifested by lytic rib lesions and an intractable pleural effusion that responded dramatically to the combination of the mammalian target of rapamycin (mTOR) inhibitor sirolimus and the aminobisphosphonate zoledronic acid after failing interferon therapy. This tolerable therapeutic combination has demonstrated synergism in preclinical cancer models and merits further study in vascular anomalies.

Successful Treatment of Recurrent Primitive Myxoid Mesenchymal Tumor of Infancy With BCOR Internal Tandem Duplication

Primitive myxoid mesenchymal tumor of infancy (PMMTI) is a rare tumor with <20 cases reported to date. Recently PMMTI tumors have been found to harbor BCOR internal tandem duplication (ITD), the same genetic alteration detected in clear cell sarcoma of the kidney (CCSK). Complete surgical resection of PMMTI is often curative, but no standard of care has been established for unresectable tumors. We describe a female patient who presented at 13 months of age with a paraspinal mass and spinal cord compression. Histology was consistent with PMMTI, and the tumor was found to harbor BCOR ITD. The patient experienced disease recurrences after multiple surgical resections. After failing to respond to vincristine and actinomycin therapy, the patient demonstrated a nearly complete response to a doxorubicin-containing chemotherapy regimen. The patients therapy was consolidated with proton beam radiotherapy, and she has remained in remission for >12 months after the conclusion of therapy. This case confirms BCOR ITD as a key finding in PMMTI. The therapeutic approach described here is similar to that used for CCSK and provides a model for the treatment of PMMTI not amenable to complete surgical resection.

Whole exome sequencing identified sixty-five coding mutations in four neuroblastoma tumors

Neuroblastoma is a pediatric tumor characterized by histologic heterogeneity, and accounts for ~15% of childhood deaths from cancer. The five-year survival for patients with high-risk stage 4 disease has not improved in two decades. We used whole exome sequencing (WES) to identify mutations present in three independent high-risk stage 4 neuroblastoma tumors (COA/UAB-3, COA/UAB -6 and COA/UAB -8) and a stage 3 tumor (COA/UAB-14). Among the four tumors WES analysis identified forty-three mutations that had not been reported previously, one of which was present in two of the four tumors. WES analysis also corroborated twenty-two mutations that were reported previously. No single mutation occurred in all four tumors or in all stage 4 tumors. Three of the four tumors harbored genes with CADD scoresu2009≥20, indicative of mutations associated with human pathologies. The average depth of coverage ranged from 39.68 to 90.27, withu2009>99% sequences mapping to the genome. In summary, WES identified sixty-five coding mutations including forty-three mutations not reported previously in primary neuroblastoma tumors. The three stage 4 tumors contained mutations in genes encoding protein products that regulate immune function or cell adhesion and tumor cell metastasis.

ICAM-2 confers a non-metastatic phenotype in neuroblastoma cells by interaction with α-actinin

Progressive metastatic disease is a major cause of mortality for patients diagnosed with multiple types of solid tumors. One of the long-term goals of our laboratory is to identifyxa0 molecular interactions that regulate metastasis, as a basis for developing agents that inhibit this process. Toward this goal, we recently demonstrated that intercellular adhesion molecule-2 (ICAM-2) converted neuroblastoma (NB) cells from a metastatic to a non-metastatic phenotype, a previously unknown function for ICAM-2. Interestingly, ICAM-2 suppressed metastatic but not tumorigenic potential in preclinical models, supporting a novel mechanism of regulating metastasis. We hypothesized that the effects of ICAM-2 on NB cell phenotype depend on the interaction of ICAM-2 with the cytoskeletal linker protein α-actinin. The goal of the study presented here was to evaluate the impact of α-actinin binding to ICAM-2 on the phenotype ofxa0NB tumor cells. We used in silico approaches to examine the likelihood that the cytoplasmic domain of ICAM-2 binds directly to α-actinin. We then expressed variants of ICAM-2 with mutated α-actinin-binding domains, and compared the impact of ICAM-2 and each variant on NB cell adhesion, migration, anchorage-independent growth, co-precipitation with α-actinin and production of localized and disseminated tumors in vivo. The in vitro and in vivo characteristics of cells expressing ICAM-2 variants with modified α-actinin-binding domains differed from cells expressing ICAM-2 wild type (WT) and also from cells that expressed no detectable ICAM-2. Like the WT protein, ICAM-2 variants inhibited cell adhesion, migration and colony growth in vitro. However, unlike the WT protein, ICAM-2 variants did not completely suppress development of disseminated NB tumors in vivo. The data suggest the presence of α-actinin-dependent and α-actinin-independent mechanisms, and indicate that the interaction of ICAM-2 with α-actinin is critical to conferring an ICAM-2-mediated non-metastatic phenotype in NB cells.

Abstract 118: The cytoplasmic domain of ICAM-2 interacts with α-actinin to confer a non-metastatic phenotype in neuroblastoma cells

Proceedings: AACR Annual Meeting 2014; April 5-9, 2014; San Diego, CAnnNeuroblastoma (NB) is the most common extracranial solid tumor in childhood, accounting for 15% of all childhood cancer deaths. Despite recent improvements in outcome for children with early stage disease, the majority of children with high-risk neuroblastoma survive less than 5 years. Nearly all newly diagnosed patients achieve apparent remission, but patients with high-risk disease relapse and die from metastatic progression within 2-5 years. Our long-range goal is to develop therapies that prevent metastatic relapse.nnWe recently made the novel observation that intercellular adhesion molecule-2 (ICAM-2) prevents development of disseminated tumors in a murine model of metastatic neuroblastoma. Interestingly, ICAM-2 suppressed metastatic but not tumorigenic potential in preclinical models, supporting a novel mechanism of regulating metastatic disease. Aside from this observation, little is known about the function of ICAM-2 in tumor cells. Importantly, and consistent with data generated using neuroblastoma cell lines, we also showed that primary human neuroblastoma cells expressing ICAM-2 are those recognized clinically to have limited metastatic potential.nnBecause the actin cytoskeletal network is a primary regulator of cell motility and metastatic potential, we hypothesized that ICAM-2 affected the phenotype of neuroblastoma cells by interacting with the actin cytoskeletal linker protein α-actinin. We used in silico modeling to examine the likelihood that the cytoplasmic domain of ICAM-2 binds directly to α-actinin. We then used site-directed mutagenesis to express variants of ICAM-2 with mutated α-actinin binding domains, and compared the impact of ICAM-2 wild type (WT) and each variant on neuroblastoma cell motility. We used dual immunofluorescence and co-immunoprecipitation approaches to demonstrate co-localization of ICAM-2 WT and α-actinin in situ; and we evaluated ICAM-2 WT and variants for their ability to produce disseminated tumors in in vivo models. In vitro and in vivo characteristics of cells expressing ICAM-2 variants with modified α-actinin binding domains differed from cells expressing ICAM-2 WT and also from cells that express no detectable ICAM-2. Unlike the WT protein, ICAM-2 variants did not completely suppress development of disseminated neuroblastoma tumors in vivo. We concluded that the interaction of ICAM-2 with α-actinin was critical to conferring the ICAM-2-mediated non-metastatic phenotype in NB cells.nnThis work was supported by the University of Alabama at Birmingham-Comprehensive Cancer Center-New Faculty Development Award (P30 CA013148).nnCitation Format: Joseph M. Feduska, Stephen G. Aller, Stuart Cramer, Robert C.A.M. van Waardenburg, Karina J. Yoon. The cytoplasmic domain of ICAM-2 interacts with α-actinin to confer a non-metastatic phenotype in neuroblastoma cells. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 118. doi:10.1158/1538-7445.AM2014-118