Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0035412 (rhabdomyosarcoma)
 6,156 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We analyzed the expression signatures of 14 tumor biopsies from children affected by alveolar rhabdomyosarcoma (ARMS) to identify genes correlating to biological features of this tumor. Seven of these patients were positive for the PAX3-FKHR fusion gene and 7 were negative. We used a cDNA platform containing a large majority of probes derived from muscle tissues. The comparison of transcription profiles of tumor samples with fetal skeletal muscle identified 171 differentially expressed genes common to all ARMS patients. The functional classification analysis of altered genes led to the identification of a group of transcripts (LGALS1, BIN1) that may be relevant for the tumorigenic processes. The muscle-specific microarray platform was able to distinguish PAX3-FKHR positive and negative ARMS through the expression pattern of a limited number of genes (RAC1, CFL1, CCND1, IGFBP2) that might be biologically relevant for the different clinical behavior and aggressiveness of the 2 ARMS subtypes. Expression levels for selected candidate genes were validated by quantitative real-time reverse-transcription PCR.
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PMID:Gene expression profiling identifies potential relevant genes in alveolar rhabdomyosarcoma pathogenesis and discriminates PAX3-FKHR positive and negative tumors. 1638 Oct 18

Rhabdomyosarcoma (RMS) is the most common childhood sarcoma and is identified as either the embryonal or alveolar (ARMS) subtype. In approximately 75% of cases, ARMSs are characterized by specific chromosomal translocations that involve PAX and FKHR genes. ARMS gene expression signatures vary, depending on the presence or absence of the translocations. Insulin-like growth factor-binding protein 2 (IGFBP2) is strongly overexpressed in translocation-negative RMS. Because IGFBP2 is associated with tumorigenesis, we investigated its functional role in RMS. An analysis of IGFBP2 distribution in RMS cell lines revealed a strong accumulation in the Golgi complex, in which morphological characteristics appeared peculiarly modified. After silencing IGFBP2 expression, our microarray analysis revealed mostly cell cycle and actin cytoskeleton gene modulations. In parallel, IGFBP2-silenced cells showed reduced cell cycle and rates of invasion and decreased seeding in the lungs after tail vein injections in immunodeficient mice. An analysis of IGFBP2 mRNA and protein localization in human tumors showed abnormal protein accumulation in the Golgi complex, mostly in PAX/FKHR-negative RMS. Moreover, an analysis of patients with RMS revealed the presence of conspicuous circulating levels of IGFBP2 proteins in children with highly aggressive RMS tumors. Taken together, our data provide evidence that IGFBP2 contributes to tumor progression and that it could be used as a marker to better classify clinical and biological risks in RMS.
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PMID:High IGFBP2 expression correlates with tumor severity in pediatric rhabdomyosarcoma. 2192 26

Embryonic rhabdomyosarcoma (ERMS) is the most common soft-tissue tumor in children. Here, we report the identification of the minor groove DNA-binding factor high mobility group AT-hook 2 (HMGA2) as a driver of ERMS development. HMGA2 was highly expressed in normal myoblasts and ERMS cells, where its expression was essential to maintain cell proliferation, survival in vitro, and tumor outgrowth in vivo. Mechanistic investigations revealed that upregulation of the insulin-like growth factor (IGF) mRNA-binding protein IGF2BP2 was critical for HMGA2 action. In particular, IGF2BP2 was essential for mRNA and protein stability of NRAS, a frequently mutated gene in ERMS. shRNA-mediated attenuation of NRAS or pharmacologic inhibition of the MAP-ERK kinase (MEK)/extracellular signal-regulated kinase (ERK) effector pathway showed that NRAS and NRAS-mediated signaling was required for tumor maintenance. Taken together, these findings implicate the HMGA2-IGFBP2-NRAS signaling pathway as a critical oncogenic driver in ERMS.
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PMID:Oncogenic NRAS, required for pathogenesis of embryonic rhabdomyosarcoma, relies upon the HMGA2-IGF2BP2 pathway. 2353 53

Agents targeting the insulin-like growth factor-1 receptor (IGF1R) are in clinical development, but, despite some initial success of single agents in sarcoma, response rates are low with brief durations. Thus, it is important to identify markers predictive of response, to understand mechanisms of resistance, and to explore combination therapies. In this study, we found that, although associated with PAX3-FKHR translocation, increased IGF1R level is an independent prognostic marker for worse overall survival, particularly in patients with PAX3-FKHR-positive rhabdomyosarcoma (RMS). IGF1R antibody-resistant RMS cells were generated using an in vivo model. Expression analysis indicated that IGFBP2 is both the most affected gene in the insulin-like growth factor (IGF) signaling pathway and the most significantly downregulated gene in the resistant lines, indicating that there is a strong selection to repress IGFBP2 expression in tumor cells resistant to IGF1R antibody. IGFBP2 is inhibitory to IGF1R phosphorylation and its signaling. Similar to antibodies to IGF1/2 or IGF2, the addition of exogenous IGFBP2 potentiates the activity of IGF1R antibody against the RMS cells, and it reverses the resistance to IGF1R antibody. In contrast to IGF1R, lower expression of IGFBP2 is associated with poorer overall survival, consistent with its inhibitory activity found in this study. Finally, blocking downstream Protein kinase B (AKT) activation with Phosphatidylinositide 3-kinases (PI3K)- or mammalian target of rapamycin (mTOR)-specific inhibitors significantly sensitized the resistant cells to the IGF1R antibody. These findings show that constitutive IGFBP2 downregulation may represent a novel mechanism for acquired resistance to IGF1R therapeutic antibody in vivo and suggest various drug combinations to enhance antibody activity and to overcome resistance.
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PMID:Downregulation of IGFBP2 is associated with resistance to IGF1R therapy in rhabdomyosarcoma. 2429 83

Insulin-like growth factor-binding protein 2 (IGFBP2) is a tumor-associated protein measurable in patients' biopsies and blood samples. Increased IGFBP2 expression correlates with tumor severity in rhabdomyosarcoma (RMS). Thus, we examined the plasmatic IGFBP2 levels in 114 RMS patients and 15 healthy controls by ELISA assay in order to evaluate its value as a plasma biomarker for RMS. Additionally, we looked for the presence of a humoral response against IGBFP2 protein measurable by the production of anti-IGFBP2 autoantibodies. We demonstrated that both circulating IGFBP2 protein and autoantibodies were significantly higher in RMS patients with respect to controls and their combination showed a better discriminative capacity. IGFBP2 protein identified metastatic patients with worse event-free survival, whereas both IGFBP2 and anti-IGFBP2 antibodies negatively correlated with overall survival. Our study suggests that IGFBP2 and anti-IGFBP2 antibodies are useful for diagnostic and prognostic purposes, mainly as independent negative prognostic markers in metastatic patients. This is the first study that reports a specific humoral response in RMS plasma samples and proves the value of blood-based biomarkers in improving risk assessment and outcome of metastatic RMS patients.
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PMID:Prognostic Value of Circulating IGFBP2 and Related Autoantibodies in Children with Metastatic Rhabdomyosarcomas. 3209 4