Andrea T. Deyrup

Characterization of the distinct orthotopic bone-forming activity of 14 BMPs using recombinant adenovirus-mediated gene delivery.

Efficacious bone regeneration could revolutionize the clinical management of bone and musculoskeletal disorders. Although several bone morphogenetic proteins (BMPs) (mostly BMP-2 and BMP-7) have been shown to induce bone formation, it is unclear whether the currently used BMPs represent the most osteogenic ones. Until recently, comprehensive analysis of osteogenic activity of all BMPs has been hampered by the fact that recombinant proteins are either not biologically active or not available for all BMPs. In this study, we used recombinant adenoviruses expressing the 14 types of BMPs (AdBMPs), and demonstrated that, in addition to currently used BMP-2 and BMP-7, BMP-6 and BMP-9 effectively induced orthotopic ossification when either AdBMP-transduced osteoblast progenitors or the viral vectors were injected into the quadriceps of athymic mice. Radiographic and histological evaluation demonstrated that BMP-6 and BMP-9 induced the most robust and mature ossification at multiple time points. BMP-3, a negative regulator of bone formation, was shown to effectively inhibit orthotopic ossification induced by BMP-2, BMP-6, and BMP-7. However, BMP-3 exerted no inhibitory effect on BMP-9-induced bone formation, suggesting that BMP-9 may transduce osteogenic signaling differently. Our findings suggest that BMP-6 and BMP-9 may represent more effective osteogenic factors for bone regeneration.

Cytoplasmic and/or nuclear accumulation of the β‐catenin protein is a frequent event in human osteosarcoma

The molecular events that precede the development of osteosarcoma, the most common primary malignancy of bone, are unclear, and concurrent molecular and genetic alterations associated with its pathogenesis have yet to be identified. Recent studies suggest that activation of β‐catenin signaling may play an important role in human tumorigenesis. To investigate the potential role of β‐catenin deregulation in human osteosarcoma, we analyzed a panel of 47 osteosarcoma samples for β‐catenin accumulation using immunohistochemistry. Potential activating mutations were investigated by sequencing exon 3 of the β‐catenin gene in genomic DNA isolated from tumor samples. Our findings revealed cytoplasmic and/or nuclear accumulation of β‐catenin in 33 of 47 samples (70.2%); however, mutation analysis failed to detect any genetic alterations within exon 3, suggesting that other regulatory mechanisms may play an important role in activating β‐catenin signaling in osteosarcoma. In our survival analysis, β‐catenin deregulation conferred a hazard ratio of 1.05, indicating that β‐catenin accumulation does not appear to be of prognostic value for osteosarcoma patients. When analyzed against other clinicopathologic parameters, β‐catenin accumulation correlated only with younger age at presentation (26.4 vs. 39.8 years). Nevertheless, our results demonstrate that the deregulation of β‐catenin signaling is a common occurrence in osteosarcoma that is implicated in the pathogenesis of osteosarcoma.

Alveolar soft-part sarcoma: a review and update

Alveolar soft-part sarcoma (ASPS) is a rare, distinctive sarcoma, typically occurring in young patients. Although it displays a relatively indolent clinical course, the ultimate prognosis is poor and is often characterised by late metastases. Recently, our understanding of the genetic events underlying the pathogenesis of ASPS has greatly increased. The historical, histopathological, ultrastructural, immunohistochemical and genetic aspects of ASPS are reviewed in this article.

Epstein-Barr virus-associated smooth muscle tumors are distinctive mesenchymal tumors reflecting multiple infection events: a clinicopathologic and molecular analysis of 29 tumors from 19 patients.

Epstein-Barr virus-associated smooth muscle tumors (EBV-SMT) are rare lesions that occur in immunocompromised patients. Because they have not been fully characterized pathologically or at the molecular level, we have studied 29 tumors from 19 patients, the largest series to date. Cases coded as EBV-SMT were identified in 19 patients from consultation files and from the renal transplant database at Singapore General Hospital. EBV-SMT occurred in adults (mean age 39 years; range, 21-57 years) and predominantly affected males (12 male, 7 female). Causes of immunocompromise were renal transplantation (10), AIDS (8), and steroid therapy (1). Tumors were located in soft tissue (5), lung (5), liver (4), and miscellaneous sites (15). In 13 patients (68%), the tumors were multiple. Infection with EBV was confirmed in all cases by in situ hybridization for EBV early RNAs (EBER). EBV-SMT were typically well-differentiated smooth muscle tumors with little atypia and usually a low level of mitotic activity. Unlike classic leiomyosarcomas, they lacked significant pleomorphism but frequently displayed primitive round cell areas and prominent intratumoral T lymphocytes. No consistent relationship between histologic features and clinical outcome was noted. All expressed actin (29 of 29) and less frequently desmin (14 of 26). Multiple tumors in a given patient were clonally distinct as assessed by the long terminal repeat region of the virus, supporting the view that multifocal tumors arise from multiple infection events rather than from metastasis. Strain typing by analysis of the EBNA-3C gene confirmed the presence of EBV type 2. Two of four tumors assessed were positive for a 30-bp deletion in the LMP1 gene. EBV copy number per cell ranged greatly between patients and between tumors from the same patient. Follow-up information was available in 18 of 19 patients (mean, 25 months; range, 1-105 months). Fifteen patients were alive: 11 with disease and 4 without. Three patients died, 1 due to disease. We conclude that EBV-SMT are histologically distinct from classic soft tissue smooth muscle tumors, are not readily evaluated by means of conventional histologic criteria, and in the case of multifocal tumors are the result of multiple infection events rather than metastasis. EBV-2 can transform smooth muscle cells, independent of the presence of the LMP1 deletion associated with greater virulence.

Grading of soft tissue sarcomas: the challenge of providing precise information in an imprecise world

By identifying patients at greatest risk for distant metastasis and, hence, most likely to benefit from adjuvant therapy, the grading of sarcomas has been one of the most important contributions pathologists have made to the treatment of sarcomas. Over the years, many grading schemes have been proposed and validated as efficacious. The three‐tier system proposed by the French Federation of Cancer Centres is precisely defined, easy to use, and is the most widely employed. However, no system performs perfectly on all sarcomas. Sarcomas that do not lend themselves well to grading include (i) those in which grade provides no incremental information over histological subtypes (e.g. well‐differentiated liposarcoma/atypical lipomatous neoplasm, Ewings sarcoma); (ii) tumours traditionally considered ‘ungradable’ (e.g. epithelioid sarcoma, clear cell sarcoma, angiosarcoma); and (iii) sarcomas that customarily have been graded but in which grade has recently been shown not to correlate well with outcome (e.g. malignant peripheral nerve sheath tumour). Consequently, several sarcoma‐specific risk stratification schemes have been proposed. The future may well witness a synthesis of these two approaches. Nomograms, which incorporate clinical, histological and demographic findings, have proved accurate in predicting disease‐specific survival in sarcomas. Diagnosis and grading are increasingly based on tissue obtained by core needle biopsy, which poses new challenges for pathologists, particularly if neoadjuvant therapy is to be given. Grading on needle biopsies may require a two‐tier grading system (i.e. low versus high grade) and a close dialogue with clinicians to resolve ambiguities.

Estrogen receptor-β expression in extraabdominal fibromatoses : An analysis of 40 cases

Early experiments using ligand‐binding assays demonstrated the presence of estrogen receptor (ER) in fibromatoses. These findings were not confirmed by later studies using immunohistochemical analysis.

Epstein-Barr virus–associated epithelial and mesenchymal neoplasms

Epstein-Barr virus (EBV) is a ubiquitous human pathogen that usually maintains a harmonious relationship with its host. Rarely, this host-virus balance is perturbed, causing a diverse group of malignancies in both immunocompetent and immunosuppressed patients. In addition to its role in hematologic malignancies (Burkitt lymphoma, subsets of Hodgkin and T-cell lymphomas, posttransplant lymphomas), EBV has been implicated in both epithelial (undifferentiated nasopharyngeal carcinoma, a subset of gastric adenocarcinomas) and mesenchymal (EBV-associated smooth muscle tumor, inflammatory pseudotumor-like follicular dendritic cell tumor) neoplasms. This review will focus on EBV-associated epithelial and mesenchymal neoplasms.

Sporadic cutaneous angiosarcomas: a proposal for risk stratification based on 69 cases.

Angiosarcomas have traditionally been considered high-grade lesions for which histologic features and grading have played no role in prognostication and, consequently, they have been excluded from the American Joint Committee on Cancer staging system. We have, therefore, analyzed 69 cutaneous angiosarcomas seen in consultation and not associated with lymphedema or prior radiation therapy to determine if a combination of histologic and clinical parameters could be used to differentiate indolent from aggressive tumors. The clinical features analyzed included patient age, location, size, depth, and focality of the lesion; the histologic features studied included pattern of growth (vasoformative vs. solid), nuclear grade (high vs. low), necrosis (present/absent), cell type (epithelioid or spindled), extent of inflammatory infiltrate (minimal vs. marked), and mitotic rate. Lesions occurred on the head/neck (49), extremities (15), and trunk (5) of adults (21 to 94 y) and predominated in males (41 males; 28 females). Tumors ranged in size from 0.3 to 15 cm (average 3.1 cm) and involved the papillary (n=9), reticular (n=16), or deep dermis/ subcutis (n=30). They could be predominantly vasoformative (n=28) to solid (greater than 50% solid, n=41). Most lesions were of high (n=65) as opposed to low (n=4) nuclear grade, were mitotically active (0 to 99/10 high power fields), and occasionally displayed necrosis (n=14) and epithelioid features (n=21). Inflammatory infiltrates were minimal in most cases. Follow-up information was obtained for all patients. Recurrences developed in 18 patients (26%) and metastasis in 15 (22%) to the following sites: lung (6), lymph node (7), liver (2), bone (2), and parotid gland (1). Forty-seven patients died (30 of disease) and 22 were alive at last known follow-up (range, 16 to 158 mo; mean, 65; median, 36). Five-year disease-specific survival was 48%. By univariate analysis only older age, anatomic site, necrosis, and epithelioid features correlated with increased mortality. Tumors were stratified into low (n=41) or high (n=28) risk groups based on necrosis and/or epithelioid features. By multivariable analysis, high-risk group (hazard ratio 4.07, P=0.0004) and age >70 (hazard ratio 2.79, P=0.012) were associated with increased mortality, and tumor depth (P=0.048) correlated with the risk of local recurrence. The high-risk group had a significantly worse prognosis than the low-risk group with 3-year survival of 24% and 77%, respectively. No patients with high-risk features survived 5 years. In conclusion, we report that a combination of clinical and histologic features allows stratification of angiosarcoma patients into 2 risk groups that are strongly associated with marked differences in clinical course. These features seem to diminish in importance with increased tumor size and are probably most useful in tumors less than 5 cm in maximum dimension.

Beta4 integrin promotes osteosarcoma metastasis and interacts with ezrin

The development of pulmonary metastasis is the major cause of death in osteosarcoma, and its molecular basis is poorly understood. In this study, we show that β4 integrin is highly expressed in human osteosarcoma cell lines and tumor samples. Furthermore, highly metastatic MNNG-HOS cells have increased levels of β4 integrin. Suppression of β4 integrin expression by shRNA and disruption of β4 integrin function by transfection of dominant-negative β4 integrin was sufficient to revert this highly metastatic phenotype in the MNNG-HOS model without significantly affecting primary tumor growth. These findings suggest a role for β4 integrin expression in the metastatic phenotype in human osteosarcoma cells. In addition, we identified a previously uncharacterized interaction between β4 integrin and ezrin, a membrane-cytoskeletal linker protein that is implicated in the metastatic behavior of osteosarcoma. The β4 integrin–ezrin interaction appears to be critical for maintenance of β4 integrin expression. These data begin to integrate ezrin and β4 integrin expression into a model of action for the mechanism of osteosarcoma metastases.

Sarcomas Arising in Paget Disease of Bone: A Clinicopathologic Analysis of 70 Cases

CONTEXT Sarcomatous transformation is a rare complication of Paget disease of bone. Prognosis in patients with other types of sarcomas arising in bone has improved in the last several decades because of therapeutic advances. However, because of the rarity of Paget sarcoma, outcome studies in these patients are limited. OBJECTIVE To determine whether prognosis for Paget sarcoma has improved. DESIGN Seventy cases of sarcomas arising in the setting of Paget disease were collected, and the histologic and clinical findings were reviewed. Clinical follow-up was obtained in 67 cases. RESULTS Sarcoma arising in Paget disease tended to arise in older men (46 men, 24 women; age range, 31-88 years; mean age, 66 years) and predominated in the axial skeleton (n = 37), especially in the pelvis. Thirty-three patients had a clinical history of Paget disease ranging in duration from 16 months to 30 years (mean, 15 years). No significant difference in incidence between monostotic (n = 33) and polyostotic (n = 36) disease was noted. Most tumors were osteosarcomas (88%). All tumors were high grade. Follow-up information was obtained in 67 of 70 cases (range of follow-up, 1-252 months). Survival ranged from 1 month to 20 years, with a 5-year survival rate of 10%. CONCLUSIONS Prognosis remains poor in patients with Paget sarcoma. There is no significant correlation between the number of bones involved with Paget disease or the duration of disease and development of Paget sarcoma. Poor prognosis in Paget sarcoma is unrelated to site or stage at presentation.