Prognostic significance of WT1 expression in soft tissue sarcoma

Indian journal of surgical oncology, 2011

Soft tissue sarcomas (STS) constitute a heterogeneous category of soft tissue neoplasia composed mostly of uncommon tumors of diverse histology, different biology and varied outcomes. Substantial developments in immunohistochemistry (IHC), cytogenetics and molecular genetics of STS have caused a significant change in the classification and diagnosis of these tumors with a direct implication for clinical management and prognosis. In this review we discuss newer developments impacting diagnosis and prediction.

Lancet, 2002

Anticancer research

Adult soft tissue sarcomas (STSs) are a rare group of highly heterogeneous neoplasms arising in different tissues. They are locally aggressive and can produce recurrence and distant metastasis. The most common metastatic sites are lung, lymph nodes, liver, bone and soft tissues. Staging for STSs has been based on some prognostic information: grade (low vs. intermediate/high grade), size (small vs. large tumors), depth of infiltration (superficial vs. deep neoplasms) and presence or not of distant metastasis. In the last 10 years, a plethora of new markers (proliferation markers and DNA alteration, P-gp, p53, TLS-CHOP, cyclins, survivin, TERT, PAX3-PAX7/FKHR, SYT-SSX1/2, VEGF, E-cadherin and beta-catenin, nm23, SKP-2, p27, CD40) has been studied with regard to their role in promoting progression (in a laboratory setting) and then determining prognosis and therapy (in a clinical setting). In the present survey, we focused on the role of new biological prognostic factors in STSs and al...

Modern Pathology, 2002

The WT1 gene encodes a transcription factor implicated in normal and neoplastic development. The purpose of this study was to evaluate the diagnostic utility of a commercial WT1 antibody on a variety of pediatric small round blue cell tumors (SRBCT). A mouse monoclonal antibody (clone: 6F-H2, DAKO) raised against the N-terminal amino acids 1-181 of the human WT1 protein was tested. Microscopic sections from 66 specimens were stained using an antigen retrieval protocol with trypsin. The tumors included peripheral neuroectodermal tumors (PNET/Ewing's), neuroblastomas, desmoplastic small round cell tumors (DSRCT), lymphomas, Wilms' tumors, and rhabdomyosarcomas (RMS). One RMS case was investigated by Western blot analysis and RT-PCR to confirm the antibody specificity. A strong cytoplasmic staining was demonstrated in all RMS (11/11). The Western blot analysis confirmed the WT1 protein in the tissue, and the RT-PCR confirmed the presence of WT1 mRNA in the peripheral blood and tissue of one RMS patient. The Wilms' tumors had a variable nuclear and/or cytoplasmic positivity in most (17/24) cases. All PNET/Ewing's were negative. The nuclei of two lymphoblastic lymphomas stained strongly. A weak nuclear or cytoplasmic staining was reported in a few DSRCT (3/5), lymphomas (2/10), and neuroblastomas (2/8). This is a useful antibody in the differentiation of RMS from other SRBCTs. A strong cyto-plasmic staining favors an RMS, and a strong nuclear staining is suggestive of a Wilms' tumor. A role for WT1 in the pathogenesis of rhabdomyosarcomas is raised. The limited sampling precludes any conclusions regarding the value of tissue or peripheral blood analysis for WT1 mRNA in patients with rhabdomyosarcoma.

Sarcoma, 2012

Basic research in sarcoma models has been fundamental in the discovery of scientific milestones leading to a better understanding of the molecular biology of cancer. Yet, clinical research in sarcoma has lagged behind other cancers because of the multiple clinical and pathological entities that characterize sarcomas and their rarity. Sarcomas encompass a very heterogeneous group of tumors with diverse pathological and clinical overlapping characteristics. Molecular testing has been fundamental in the identification and better definition of more specific entities among this vast array of malignancies. A group of sarcomas are distinguished by specific molecular aberrations such as somatic mutations, intergene deletions, gene amplifications, reciprocal translocations, and complex karyotypes. These and other discoveries have led to a better understanding of the growth signals and the molecular pathways involved in the development of these tumors. These findings are leading to treatment strategies currently under intense investigation. Disruption of the growth signals is being targeted with antagonistic antibodies, tyrosine kinase inhibitors, and inhibitors of several downstream molecules in diverse molecular pathways. Preliminary clinical trials, supported by solid basic research and strong preclinical evidence, promises a new era in the clinical management of these broad spectrum of malignant tumors.

Clinical cancer research : an official journal of the American Association for Cancer Research, 2003

Sarcomas--like leukemias, which are also mesodermal malignancies--carry biological significance disproportionate to their clinical frequency. Identification of mutations and translocations associated with these tumors has illuminated aberrant signaling pathways that cause these diseases, determine their behavior, and are therapeutic targets. Activated receptor-associated tyrosine kinase c-kit, mutated in most gastrointestinal stromal tumors, has proven a clinically effective target for enzyme inhibition. A translocation involving a single gene family, consisting of EWS and related genes, has been identified in five different sarcomas, and its chimeric protein products could prove similarly amenable to inhibitors. Resolution of the histopathological complexity is being aided by data from molecular and chromosomal characterization. Improvements in imaging, definition of prognostic factors, and surgical and radiotherapeutic treatment have resulted in improved local control. Continued p...

2013

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PLoS ONE, 2014

Wilms' tumor gene 1 (WT1) plays complex roles in tumorigenesis, acting as tumor suppressor gene or an oncogene depending on the cellular context. WT1 expression has been variably reported in both benign and malignant peripheral nerve sheath tumors (MPNSTs) by means of immunohistochemistry. The aim of the present study was to characterize its potential pathogenetic role in these relatively uncommon malignant tumors. Firstly, immunohistochemical analyses in MPNST sNF96.2 cell line showed strong WT1 staining in nuclear and perinuclear areas of neoplastic cells. Thus, we investigated the effects of silencing WT1 by RNA interference. Through Western Blot analysis and proliferation assay we found that WT1 knockdown leads to the reduction of cell growth in a time-and dosedependent manner. siWT1 inhibited proliferation of sNF96.2 cell lines likely by influencing cell cycle progression through a decrease in the protein levels of cyclin D1 and inhibition of Akt phosphorylation compared to the control cells. These results indicate that WT1 knockdown attenuates the biological behavior of MPNST cells by decreasing Akt activity, demonstrating that WT1 is involved in the development and progression of MPNSTs. Thus, WT1 is suggested to serve as a potential therapeutic target for MPNSTs.

International journal of clinical and experimental pathology, 2010

Sarcomas are a heterogeneous group of tumors that are traditionally classified according to the morphology and type of tissue that they resemble, such as rhabdomyosarcoma, which resembles skeletal muscle. However, the cell of origin is unclear in numerous sarcomas. Molecular genetics analyses have not only assisted in understanding the molecular mechanism in sarcoma pathogenesis but also demonstrated new relationships within different types of sarcomas leading to a more proper classification of sarcomas. Molecular classification based on the genetic alteration divides sarcomas into two main categories: (i) sarcomas with specific genetic alterations; which can further be subclassified based on a) reciprocal translocations resulting in oncogenic fusion transcripts (e.g. EWSR1-FLI1 in Ewing sarcoma) and b) specific oncogenic mutations (e.g. KIT and PDGFRA mutations in gastrointestinal stromal tumors) and (ii) sarcomas displaying multiple, complex karyotypic abnormalities with no specif...

Human pathology, 2005

In 140 mixed primary soft tissue sarcomas with a median follow-up of 6 years, the prognostic importance of tumor size, tumor depth, grade, necrosis, vascular invasion, and peripheral growth pattern (pushing versus infiltrating) was evaluated on whole-tumor sections. Immunohistochemical expression of Ki-67, p53, cyclin A, bcl-2, beta-catenin, CD44, and P-glycoprotein was determined using tissue microarray from the peripheral growth zone. Local recurrences developed in 17% of the patients and correlated with necrosis, vascular invasion, and cyclin A expression. No local recurrence developed in tumors with a pushing growth pattern, regardless of tumor grade and depth. Metastasis developed in 39% of the patients. Vascular invasion was identified in 36% of the tumors and was the strongest prognostic factor for metastasis with a hazard ratio of 3.5. Growth pattern and tumor necrosis were also strong prognostic factors for metastasis, whereas malignancy grade, tumor size, and tumor depth d...