Genetic characterization of intramuscular myxomas

Introduction: Intramuscular myxomas are benign tumors that are challenging to diagnose, especially on core needle biopsies. Acquired chromosomal aberrations and pathogenic variants in codon 201 or codon 227 in GNAS complex locus gene (GNAS) have been reported in these tumors. Here we present our genetic findings in a series of 22 intramuscular myxomas. Materials and methods: The tumors were investigated for the presence of acquired chromosomal aberrations using G-banding and karyotyping. Pathogenic variants in codon 201 or codon 227 of GNAS were assessed using direct cycle Sanger sequencing and Ion AmpliSeq Cancer Hotspot Panel v2 methodologies. Results: Eleven tumors carried chromosomal abnormalities. Six tumors had numerical, four had structural, and one had both numerical and structural chromosomal aberrations. Gains of chromosomes 7 and 8 were the most common abnormalities being found in five and four tumors respectively. Pathogenic variants in GNAS were detected in 19 myxomas (86%) with both methodologies. The detected pathogenic variants were p.R201H in nine cases (seven with abnormal and two with normal karyotypes), p.R201C in five cases, all with normal karyotypes, p.R201S in three cases (two with abnormal and one with normal karyotype), p.R201G in one case with a normal karyotype, and p.Q227E in one case with a normal karyotype. Conclusion: Firstly, our data indicate a possible association between chromosomal abnormalities and GNAS pathogenic variants in intramuscular myxomas. Secondly, the presence of the rare pathogenic variants R201S, p.R201G and p.Q227E in 26% (5 out of 19) of myxomas with GNAS pathogenic variants shows that methodologies designed to detect only the common "hotspot" of p.R201C and p.R201H will give false negative results. Finally, a comparison between Ion AmpliSeq Cancer Hotspot Panel v2 and direct cycle Sanger sequencing showed that direct cycle Sanger sequencing provides a quick, reliable, and relatively cheap method to detect GNAS pathogenic variants, matching even the most cutting-edge sequencing methods.

The KrasG12D;Trp53fl/fl murine model of undifferentiated pleomorphic sarcoma is macrophage dense, lymphocyte poor, and resistant to immune checkpoint blockade

Sarcomas are rare, difficult to treat, mesenchymal lineage tumours that affect children and adults. Immunologically-based therapies have improved outcomes for numerous adult cancers, however, these therapeutic strategies have been minimally effective in sarcoma so far. Clinically relevant, immunologically-competent, and transplantable pre-clinical sarcoma models are essential to advance sarcoma immunology research. Herein we show that Cre-mediated activation of Kras^G12D, and deletion of Trp53, in the hindlimb muscles of C57Bl/6 mice results in the highly penetrant, rapid onset undifferentiated pleomorphic sarcomas (UPS), one of the most common human sarcoma subtypes. Cell lines derived from spontaneous UPS tumours can be reproducibly transplanted into the hindlimbs or lungs of naïve, immune competent syngeneic mice. Immunological characterization of both spontaneous and transplanted UPS tumours demonstrates an immunologically-‘quiescent’ microenvironment, characterized by a paucity of lymphocytes, limited spontaneous adaptive immune pathways, and dense macrophage infiltrates. Macrophages are the dominant immune population in both spontaneous and transplanted UPS tumours, although compared to spontaneous tumours, transplanted tumours demonstrate increased spontaneous lymphocytic infiltrates. The growth of transplanted UPS tumours is unaffected by host lymphocyte deficiency, and despite strong expression of PD-1 on tumour infiltrating lymphocytes, tumours are resistant to immunological checkpoint blockade. This spontaneous and transplantable immune competent UPS model will be an important experimental tool in the pre-clinical development and evaluation of novel immunotherapeutic approaches for immunologically cold soft tissue sarcomas.

A comprehensive molecular characterization of the 8q22.2 region reveals the prognostic relevance of OSR2 mRNA in muscle invasive bladder cancer

Technological advances in molecular profiling have enabled the comprehensive identification of common regions of gene amplification on chromosomes (amplicons) in muscle invasive bladder cancer (MIBC). One such region is 8q22.2, which is largely unexplored in MIBC and could harbor genes with potential for outcome prediction or targeted therapy. To investigate the prognostic role of 8q22.2 and to compare different amplicon definitions, an in-silico analysis of 357 patients from The Cancer Genome Atlas, who underwent radical cystectomy for MIBC, was performed. Amplicons were generated using the GISTIC2.0 algorithm for copy number alterations (DNA_Amplicon) and z-score normalization for mRNA gene overexpression (RNA_Amplicon). Kaplan-Meier survival analysis, univariable, and multivariable Cox proportional hazard ratios were used to relate amplicons, genes, and clinical parameters to overall (OS) and disease-free survival (DFS). Analyses of the biological functions of 8q22.2 genes and genomic events in MIBC were performed to identify potential targets. Genes with prognostic significance from the in silico analysis were validated using RT-qPCR of MIBC tumor samples (n = 46). High 8q22.2 mRNA expression (RNA-AMP) was associated with lymph node metastases. Furthermore, 8q22.2 DNA and RNA amplified patients were more likely to show a luminal subtype (DNA_Amplicon_core: p = 0.029; RNA_Amplicon_core: p = 0.01). Overexpression of the 8q22.2 gene OSR2 predicted shortened DFS in univariable (HR [CI] 1.97 [1.2; 3.22]; p = 0.01) and multivariable in silico analysis (HR [CI] 1.91 [1.15; 3.16]; p = 0.01) and decreased OS (HR [CI] 6.25 [1.37; 28.38]; p = 0.0177) in RT-qPCR data analysis. Alterations in different levels of the 8q22.2 region are associated with manifestation of different clinical characteristics in MIBC. An in-depth comprehensive molecular characterization of genomic regions involved in cancer should include multiple genetic levels, such as DNA copy number alterations and mRNA gene expression, and could lead to a better molecular understanding. In this study, OSR2 is identified as a potential biomarker for survival prognosis.

Tumor Infiltrating Neutrophils Are Enriched in Basal-Type Urothelial Bladder Cancer

Background: Urothelial bladder cancers (UBCs) are distinct in two main molecular subtypes, namely basal and luminal type. Subtypes are also diverse in term of immune contexture, providing a rationale for patient selection to immunotherapy. Methods: By digital microscopy analysis of a muscle-invasive BC (MIBC) cohort, we explored the density and clinical significance of CD66b⁺ tumor-associated-neutrophils (TAN) and CD3⁺ T cells. Bioinformatics analysis of UBC datasets and gene expression analysis of UBC cell lines were additionally performed. Results: Basal type BC contained a significantly higher density of CD66b⁺ TAN compared to the luminal type. This finding was validated on TCGA, GSE32894 and GSE124305 datasets by computing a neutrophil signature. Of note, basal-type MIBC display a significantly higher level of chemokines (CKs) attracting neutrophils. Moreover, pro-inflammatory stimuli significantly up-regulate CXCL1, CXCL2 and CXCL8 in 5637 and RT4 UBC cell lines and induce neutrophil chemotaxis. In term of survival, a high density of T cells and TAN was significantly associated to a better outcome, with TAN density showing a more limited statistical power and following a non-linear predicting model. Conclusions: TAN are recruited in basal type MIBC by pro-inflammatory CKs. This finding establishes a groundwork for a better understanding of the UBC immunity and its relevance.

Long non-coding RNAs identify a subset of luminal muscle-invasive bladder cancer patients with favorable prognosis

BACKGROUND

Muscle-invasive bladder cancer (MIBC) is a heterogeneous disease, and gene expression profiling has identified several molecular subtypes with distinct biological and clinicopathological characteristics. While MIBC subtyping has primarily been based on messenger RNA (mRNA), long non-coding RNAs (lncRNAs) may provide additional resolution.

METHODS

LncRNA expression was quantified from microarray data of a MIBC cohort treated with neoadjuvant chemotherapy (NAC) and radical cystectomy (RC) (n = 223). Unsupervised consensus clustering of highly variant lncRNAs identified a four-cluster solution, which was characterized using a panel of MIBC biomarkers, regulon activity profiles, gene signatures, and survival analysis. The four-cluster solution was confirmed in The Cancer Genome Atlas (TCGA) cohort (n = 405). A single-sample genomic classifier (GC) was trained using ridge-penalized logistic regression and validated in two independent cohorts (n = 255 and n = 94).

RESULTS

NAC and TCGA cohorts both contained an lncRNA cluster (LC3) with favorable prognosis that was enriched with tumors of the luminal-papillary (LP) subtype. In both cohorts, patients with LP tumors in LC3 (LPL-C3) were younger and had organ-confined, node-negative disease. The LPL-C3 tumors had enhanced FGFR3, SHH, and wild-type p53 pathway activity. In the TCGA cohort, LPL-C3 tumors were enriched for FGFR3 mutations and depleted for TP53 and RB1 mutations. A GC trained to identify these LPL-C3 patients showed robust performance in two validation cohorts.

CONCLUSIONS

Using lncRNA expression profiles, we identified a biologically distinct subgroup of luminal-papillary MIBC with a favorable prognosis. These data suggest that lncRNAs provide additional information for higher-resolution subtyping, potentially improving precision patient management.

MicroRNAs in tumor samples and urinary extracellular vesicles as a putative diagnostic tool for muscle-invasive bladder cancer

PURPOSE

The identification of biomarkers characterizing the invasive potential of bladder cancer could enhance the clinical management of individual patients and therefore improve prognosis. The aim of this study was to define a miRNA panel in tumor tissues as well as in urinary extracellular vesicles (EVs) for discriminating muscle-invasive bladder cancer (MIBC) from non-muscle-invasive bladder cancer (NMIBC).

METHODS

miRNA expression was analyzed in 24 formalin-fixed, paraffin-embedded (FFPE) tumor samples by microarray analysis and was further validated by qRT-PCR in 56 FFPE tumor samples as well as in 37 urinary EV samples.

RESULTS

Microarray analysis revealed 63 miRNAs that were significantly differentially expressed (P < 0.05) between tissues from MIBC and NMIBC tumors. Five selected miRNAs (miR-146b-5p, miR-155-5p, miR-138-5p, miR-144-5p, and miR-200a-3p) were validated by qRT-PCR. The expression of all except miR-144-5p was significantly associated with high tumor grade. In urinary EVs, a different expression was verified for miR-146b-5p (P = 0.004) and miR-155-5p (P = 0.036), which exhibited significantly higher expression in urinary EVs from patients with MIBC.

CONCLUSIONS

miRNAs are promising biomarkers for the identification of invasive bladder carcinomas. Tissue samples as well as urinary EVs may serve as sources for miRNA analysis. This method, in addition to histopathology, could provide a new diagnostic tool and facilitate individual therapeutic decisions to select patients for early cystectomy.

Mouse Models of Muscle-invasive Bladder Cancer: Key Considerations for Clinical Translation Based on Molecular Subtypes

CONTEXT

In the past few years, research has suggested that molecular subtypes in muscle-invasive bladder cancer (MIBC) may be exploited to accelerate developments in clinical disease management and novel therapeutics.

OBJECTIVE

To review MIBC mouse models from a molecular subtype perspective, their advantages and limitations, and their applications in translational medicine, based on a PubMed search for publications from January 2000 to February 2018.

EVIDENCE ACQUISITION

Publications relevant to MIBC mouse models and their molecular subtypes were identified in a literature review.

EVIDENCE SYNTHESIS

We classified the models according to the technique used for their establishment. For xenotransplant and allograft models, the inoculated cells and inoculated locations are the major determinants of molecular subtypes. Although the cell lines used in xenotransplant models can cover most of the basal-squamous and luminal subtypes, allograft models offer a more realistic environment in which to reconstruct aspects of the associated stromal and immune features. Autochthonous models, using genetic and/or chemical stimuli to induce disease progression, can also generate models with basal-squamous and luminal subtypes, but further molecular characterisation is needed since other mutational variants may be introduced in these models.

CONCLUSIONS

We identified preclinical MIBC models with different subtype specifications and assessed their promise and current limitations. These models are versatile tools that can reproduce the molecular complexity of MIBC and support novel therapeutic development.

PATIENT SUMMARY

Understanding which models of muscle-invasive bladder cancer most accurately represent the clinical situation is important for the development of novel drugs and disease management strategies. We review the different models currently available and their relevance to different clinical subtypes.

CDKN2A as transcriptomic marker for muscle-invasive bladder cancer risk stratification and therapy decision-making

Deletions of the cell cycle control gene CDKN2A are described as progression markers of non-muscle invasive bladder cancer and to be associated with fibroblast growth factor 3 (FGFR3) mutations. The prognostic role of CDKN2A RNA expression in muscle invasive bladder cancer (MIBC) is under discussion. In 80 MIBC patients (m/f 60/20) who underwent radical cystectomy the expression of CDKN2A and FGFR3 was examined with qRT-PCR (test cohort). The MDA cohort (n = 57) and the TCGA cohort (n = 365) served for validation. The expression of drug target genes and TCGA molecular subtypes was correlated with CDKN2A expression. In the test cohort CDKN2Ahigh patients (n = 8; 10.0%) had a significantly shorter recurrence-free (p = 0.018) and disease-specific (p = 0.006) survival compared to the rest of the cohort. A similar stratification was seen in the validation cohorts (CDKN2Ahigh: n = 7, 12.3%, p = 0.001; n = 46, 12.6%, p = 0.011). In the TCGA cohort these patients had a comparably low expression of drug target genes. The expression of CDKN2A significantly differed among TGCA molecular subtypes. 71.7% of CDKN2Ahigh were TCGA basal squamous tumours but also show divergent molecular features compared to this group. In summary CDKN2A RNA expression-based risk stratification of MIBC allows the identification of a CDKN2Ahigh poor prognosis group with low expression of drug target genes.

Identification of Therapeutic Targets in Rhabdomyosarcoma through Integrated Genomic, Epigenomic, and Proteomic Analyses

Personalized cancer therapy targeting somatic mutations in patient tumors is increasingly being incorporated into practice. Other therapeutic vulnerabilities resulting from changes in gene expression due to tumor specific epigenetic perturbations are progressively being recognized. These genomic and epigenomic changes are ultimately manifest in the tumor proteome and phosphoproteome. We integrated transcriptomic, epigenomic, and proteomic/phosphoproteomic data to elucidate the cellular origins and therapeutic vulnerabilities of rhabdomyosarcoma (RMS). We discovered that alveolar RMS occurs further along the developmental program than embryonal RMS. We also identified deregulation of the RAS/MEK/ERK/CDK4/6, G₂/M, and unfolded protein response pathways through our integrated analysis. Comprehensive preclinical testing revealed that targeting the WEE1 kinase in the G₂/M pathway is the most effective approach in vivo for high-risk RMS.

Melanoma patient response to nivolumab treatment for metastatic lung lesions: Multi-OMICS analysis in Project HOPE

A 70-year-old woman was diagnosed with a malignant melanoma of the occipital skin which was resected; however, multiple lung metastases were detected. Nivolumab therapy was initiated and partial response was obtained. However, the patient was diagnosed with grade 2 interstitial pneumonitis. Prednisolone administration was initiated and the interstitial pneumonitis shadow disappeared. However, then a right rib metastasis was noticed and given radiation therapy. After progressive disease was obtained, the metastatic lesion was resected, and no relapse occurred until skeletal muscle metastasis was found. According to whole-exome sequencing and gene expression profiling, the rib and skeletal muscle metastatic lesions showed an upregulated expression of programmed death-ligand 1 mRNA and a high single-nucleotide variant (SNV) number. The current melanoma case is representative of a patient who responded to nivolumab therapy, and showed typical immunological markers for responders such as high PD-L1 expression and high SNV.

Endothelin-1 overexpression: a potential biomarker of unfavorable prognosis in non-metastatic muscle-invasive bladder cancer

Endothelin-1 (ET-1) is a multifunctional peptide exerting its effects via receptors A and B. ET-1 and its receptors, endothelin axis (ET axis), play a promoting role in cancer biology. Alterations of proteins of ET axis have been detected in non-metastatic muscle-invasive bladder cancer (NMMIBC). The objective of this study is to investigate the potential role of ET-1 tumor expression as a biomarker of prognosis, compared to other prognostic parameters (epidemiologic and pathologic), in NMMIBC. We prospectively included 40 consecutive, primary, high-grade NMMIBC patients. Tumor specimens after initial transurethral resection were stained immunohistochemically for ET-1. The ET-1 evaluation of expression was based on staining intensity (SI) of ET-1. SI was classified according to an arbitrary four-tiered scale (negative = 0, mild = 1, moderate = 2, strong = 3). Epidemiologic and pathologic parameters were analyzed, using univariate and multivariate statistics, for disease progression, progression-free survival (PFS), and overall survival (OS). ET-1 overexpression (SI = 3) was the unique parameter which associated significantly, both in univariate (log-rank test, p = 0.033) and multivariate (Cox regression analysis, p = 0.045, HR = 4.849, 95 % CI: 1.039-22.624) analysis, with an increased hazard ratio of progression. ET-1 overexpression (SI = 3) was also the unique parameter which associated, marginally significantly in univariate analysis (log-rank test, p = 0.056) and highly significantly in multivariate analysis (Cox regression analysis, p = 0.005, HR = 7.001, 95 % CI: 1.782-27.501), with an increased hazard ratio of death. Overexpression of ET-1 may be a potential biomarker of unfavorable prognosis in NMMIBC patients.

Rhabdomyosarcoma: current challenges and their implications for developing therapies

Rhabdomyosarcoma (RMS) represents a rare, heterogeneous group of mesodermal malignancies with skeletal muscle differentiation. One major subgroup of RMS tumors (so-called "fusion-positive" tumors) carries exclusive chromosomal translocations that join the DNA-binding domain of the PAX3 or PAX7 gene to the transactivation domain of the FOXO1 (previously known as FKHR) gene. Fusion-negative RMS represents a heterogeneous spectrum of tumors with frequent RAS pathway activation. Overtly metastatic disease at diagnosis is more frequently found in individuals with fusion-positive than in those with fusion-negative tumors. RMS is the most common pediatric soft-tissue sarcoma, and approximately 60% of all children and adolescents diagnosed with RMS are cured by currently available multimodal therapies. However, a curative outcome is achieved in <30% of high-risk individuals with RMS, including all those diagnosed as adults, those diagnosed with fusion-positive tumors during childhood (including metastatic and nonmetastatic tumors), and those diagnosed with metastatic disease during childhood (including fusion-positive and fusion-negative tumors). This white paper outlines current challenges in RMS research and their implications for developing more effective therapies. Urgent clinical problems include local control, systemic disease, need for improved risk stratification, and characterization of differences in disease course in children and adults. Biological challenges include definition of the cellular functions of PAX-FOXO1 fusion proteins, clarification of disease heterogeneity, elucidation of the cellular origins of RMS, delineation of the tumor microenvironment, and identification of means for rational selection and testing of new combination therapies. To streamline future therapeutic developments, it will be critical to improve access to fresh tumor tissue for research purposes, consider alternative trial designs to optimize early clinical testing of candidate drugs, coalesce advocacy efforts to garner public and industry support, and facilitate collaborative efforts between academia and industry.

Pattern of somatostatin receptors expression in normal and bladder cancer tissue samples

BACKGROUND/AIM

Known risks factors for bladder cancer progression and recurrence are limited regarding their prognostic ability. Therefore identification of molecular determinants of disease progression could provide with more specific prognostic information and could be translated into new approaches for biomarker development. In the present study we evaluated, the expression patterns of somatostatin receptors 1-5 (SSTRs) in normal and tumor bladder tissues.

MATERIALS AND METHODS

The expression of SSTR1-5 was characterized in 45 normal and bladder cancer tissue samples using reverse transcriptase-polymerase chain reaction (RT-PCR).

RESULTS

SSTR1 was expressed in 24 samples, SSTR2 in 15, SSTR3 in 23, SSTR4 in 16 and SSTR5 in all but one sample. Bladder cancer tissue samples expressed lower levels of SSTR3. Co-expression of SSTRs was associated with superficial disease.

CONCLUSION

Our results demonstrate, for the first time, that there is expression of SSTR in normal and bladder cancer urothelium. Further studies are required to evaluate the prognostic and therapeutic significance of these findings.

Detection of micrometastases of squamous cell carcinoma tumor cells in muscle tissue

The aim of this study was to evaluate microarray technology in the detection of micrometastases of head and neck squamous cell carcinoma (HNSCC) in muscle tissue. Three hundred SCCVII tumor cells were injected intramuscularly into the right flank of ten C3H/Km mice. One week later, the animals were euthanized and the muscle tissue was taken out. Histology (H&E staining), microarray and reverse transcriptase polymerase chain reaction analysis (RT-PCR) of the tissue was performed. Histology showed a few tumor cells between the muscle fibers. Microarray technology showed the different gene expression pattern of the muscle tissue with micrometastases in comparison to normal muscle tissue. Only genes with a fold change difference of 10 or greater were considered. Gene expression analysis revealed changes in the expression levels of 91 genes of micrometastases in muscle tissue. RT-PCR confirmed gene up-regulation. Significant differences in gene expression between micrometastases in muscle tissue and pure muscle tissue were found. The genes found to be up-regulated could be used to detect micrometastases in muscle tissue.

Structural and functional studies of FKHR-PAX3, a reciprocal fusion gene of the t(2;13) chromosomal translocation in alveolar rhabdomyosarcoma

Alveolar rhabdomyosarcoma (ARMS) is an aggressive pediatric cancer of skeletal muscle. More than 70% of ARMS tumors carry balanced t(2;13) chromosomal translocation that leads to the production of two novel fusion genes, PAX3-FKHR and FKHR-PAX3. While the PAX3-FKHR gene has been intensely studied, the reciprocal FKHR-PAX3 gene has rarely been described. We report here the cloning and functional characterization of the FKHR-PAX3 gene as the first step towards a better understanding of its potential impact on ARMS biology. From RH30 ARMS cells, we detected and isolated three versions of FKHR-PAX3 cDNAs whose C-terminal sequences corresponded to PAX3c, PAX3d, and PAX3e isoforms. Unlike the nuclear-specific localization of PAX3-FKHR, the reciprocal FKHR-PAX3 proteins stayed predominantly in the cytoplasm. FKHR-PAX3 potently inhibited myogenesis in both non-transformed myoblast cells and ARMS cells. We showed that FKHR-PAX3 was not a classic oncogene but could act as a facilitator in oncogenic pathways by stabilizing PAX3-FKHR expression, enhancing cell proliferation, clonogenicity, anchorage-independent growth, and matrix adhesion in vitro, and accelerating the onset of tumor formation in xenograft mouse model in vivo. In addition to these pro-oncogenic behaviors, FKHR-PAX3 also negatively affected cell migration and invasion in vitro and lung metastasis in vivo. Taken together, these functional characteristics suggested that FKHR-PAX3 might have a critical role in the early stage of ARMS development.

Isolation and characterization of endothelial cells from intramuscular hemangioma

BACKGROUND

Intramuscular hemangiomas (IMHs) are benign vascular tumors of deep soft tissue characterized by endothelial cell (EC) proliferation. The purpose of this study was to isolate ECs from IMH, characterize their angiogenic phenotype and functional characteristics, and search for a possible signaling pathway related to IMH development.

METHODS

EC Isolation from IMH was performed by digestion, filtration, washing, incubation, and purification in sequence. Tie2 expression was compared between ECs from IMH and controls using reverse transcriptase polymerase chain reaction (RT-PCR). Cell invasion and proliferation assays were used to analyze functional responses of ECs to angiopoietin 1 (Ang1) and vascular endothelial growth factor (VEGF). Expression of downstream targets was analyzed using Western blot analysis.

RESULTS

Isolated ECs showed typical cobblestone appearance under light microscopy and formed capillary-like tubular structures using Matrigel tube-forming assay. RT-PCR of isolated ECs from six patients showed increased expression of Tie2 and VEGF receptor 1 (VEGFR1) compared with control ECs. Tie2 activation by Ang1 compared with VEGFR1 by VEGF resulted in increased EC migration and proliferation. Western blot analysis showed increased Tie2 expression in hemangioma samples compared with normal ECs. Phosphorylated Akt and phosphorylated forkhead box O1 (FOXO1) expression was observed in hemangioma samples only.

CONCLUSION

EC isolation from IMH could be a useful tool for further research. These results suggest that increased Tie2 expression, via Akt-FOXO1 pathway activation, may play an important role in IMH pathogenesis.

Bioinformatic analysis of patient-derived ASPS gene expressions and ASPL-TFE3 fusion transcript levels identify potential therapeutic targets

Gene expression data, collected from ASPS tumors of seven different patients and from one immortalized ASPS cell line (ASPS-1), was analyzed jointly with patient ASPL-TFE3 (t(X;17)(p11;q25)) fusion transcript data to identify disease-specific pathways and their component genes. Data analysis of the pooled patient and ASPS-1 gene expression data, using conventional clustering methods, revealed a relatively small set of pathways and genes characterizing the biology of ASPS. These results could be largely recapitulated using only the gene expression data collected from patient tumor samples. The concordance between expression measures derived from ASPS-1 and both pooled and individual patient tumor data provided a rationale for extending the analysis to include patient ASPL-TFE3 fusion transcript data. A novel linear model was exploited to link gene expressions to fusion transcript data and used to identify a small set of ASPS-specific pathways and their gene expression. Cellular pathways that appear aberrantly regulated in response to the t(X;17)(p11;q25) translocation include the cell cycle and cell adhesion. The identification of pathways and gene subsets characteristic of ASPS support current therapeutic strategies that target the FLT1 and MET, while also proposing additional targeting of genes found in pathways involved in the cell cycle (CHK1), cell adhesion (ARHGD1A), cell division (CDC6), control of meiosis (RAD51L3) and mitosis (BIRC5), and chemokine-related protein tyrosine kinase activity (CCL4).

Association of hOGG1 and XPD polymorphisms with urothelial carcinoma in Taiwan

The aim of this study was to investigate the association of human oxoguanine glycosylase (hOGG1) and xeroderma pigmentosum group D (XPD) polymorphisms with urothelial carcinoma (UC) in Taiwan.

PATIENTS AND METHODS

This hospital-based case-control study included 460 UC cases and 540 cancer-free controls, who had been frequency matched by age and gender, between August 2006 and October 2009. The joint effects of cigarette smoking, alcohol consumption and risk genotypes of the hOGG1 and XPD genes on UC risk was estimated using an unconditional logistic regression.

RESULTS

Individuals carrying both the hOGG1 (C/G or G/G) and XPD (A/C or C/C) risk genotypes had a significantly higher UC risk (OR=1.8, 95% CI=1.01-3.0) than the hOGG1 (C/C) and XPD (A/A) reference group. Those who had a history of cigarette smoking and alcohol consumption carrying both the hOGG1 and XPD risk genotypes had the highest UC risk (OR=9.9, 95% CI= 4.5-21.8). The UC cases carrying both the hOGG1 and XPD risk genotypes had a significantly increased risk (OR=5.2, 95% CI=1.2-22.3) of high grade tumor.

CONCLUSION

A significant joint effect of cigarette smoking, alcohol consumption and both hOGG1 and XPD risk genotypes increases UC risk and UC cases carrying both hOGG1 and XPD risk genotypes have a significantly greater risk of high grade tumor.

TRAF6 regulates proliferation and differentiation of skeletal myoblasts

We could recently demonstrate an important role of receptor interacting protein-2 (RIP2), an activator of nuclear factor kappa B (NF-κB) and a target of activated receptors of the tumor necrosis factor receptor (TNFR) type, in myogenic differentiation and regeneration. Here, we analyze a potential role of TNFR associated factor 6 (TRAF6), which also associates with the cytoplasmic domain of TNFR type, but also IL-1-R and TLR type receptors, and activates NF-κB, in these processes. Specifically, we show that during myogenic differentiation in vitro, traf6 gene expression is downregulated in normal myoblasts, but not in rhabdomyosarcoma cells, suggesting a role of the TRAF6 protein in this process. Inhibition of traf6 expression using specific siRNAs led to an inhibition of both myoblast proliferation and differentiation, whereas inhibition of the TRAF6 effector NF-κB alone in our system only blocked proliferation. Finally, we demonstrate that the traf6 gene is downregulated in skeletal muscle tissue of the dystrophic mdx mouse. Taken together, these data argue for a role of TRAF6 in the regulation of skeletal muscle differentiation and regeneration.

Prognostic significance of fluorescent in situ hybridisation in the follow-up of non-muscle-invasive bladder cancer

AIM

To evaluate the potential contribution of a fluorescent in situ hybridization (FISH) as prognostic indicator of the risk of recurrence or progression in patients undergoing follow-up for non-muscle-invasive bladder cancer (NMIBC).

PATIENTS AND METHODS

A total of 126 consecutive patients with a history of NMIBC being followed-up with urinary cytology and cystoscopy at a referral centre were studied. Patients with carcinoma in situ, or tumour stage higher than pT1 were excluded. A UroVysion FISH kit was used to detect four chromosomal abnormalities, specifically, locus 9p21, Ch 3, 7, and 17. Three FISH patterns were defined: negative; low-risk positive, i.e. positive staining for 9p21 and/or Ch3 abnormalities; and high-risk positive, i.e. positive staining for Ch7 and/or 17.

RESULTS

Overall 73 out of 126 patients (57.9%) had a positive urinary FISH test. After a median time of 14 months, 46 FISH-positive patients underwent recurrence (36.5%) and in 15 patients there was progression of disease (11.9%). Among positive patients, the low-risk category was found in 34, and the high-risk in 39. Low-risk FISH-positive patients had a higher rate of recurrence as compared to FISH-negative patients, with a hazard ratio (HR) of 1.6. The recurrence rate was even greater in patients with a high-risk positive test, with an HR of 1.9. The limitation of the study was that the impact of intravesical treatment was not assessed.

CONCLUSION

The urinary FISH test can be used as an aid in predicting the risk of recurrence during follow-up of patients with history of NMIBC.

[Morpho-functional iterative surgery in a patient with von Recklinghausen disease]

Neurofibromatosis 1 is an autosomal dominant disease with an estimated incidence 1:2500 to 1:3000 live newborns. The disease presents with multiple cutaneous and non cutaneous lesions. NF1 occurs with equal frequency in males and females and has been identified in all ethnic group. The morbidity and the mortality caused by NF1 are the result of complications that may involve any of the body systems. This disease has been linked with mutations of the NF1 gene which encodes tumor suppressor neurofibromin. At least half of patients with NF1 will have only cutaneous involvement that is not considered to be a major medical problem, even though it can be a source of psychologic burden as a result of cosmetic disfigurement. The cardinal features of the disorder are cafè-au-lait spots, axillary freckling, cutaneous neurofibromas and Lisch nodules, but there are a lot of wide variety of complications affecting almost every system of the body, including the eyes (optic glioma), the nervous system (intracranial tumors), the skeleton (short stature, scoliosis), the endocrine and cardiovascular system (hypertension). Manifestations of NF1 vary at different times in an individual's life. Substantial variability exists among affected members of a single family. This variability confounds clinical management and the severity of the disease cannot be predicted. We present a case in young woman 24 years-old treated by reiterative plastic surgery.

Tumor suppressor gene alterations of spontaneously malignant transformed cells from human embryonic muscle in vitro

Recent research has shown that mesenchymal stem cells (MSCs) which were cultured for long time could transform malignantly, the transformation mechanism is not clear yet, it might be associated with the activation of oncogenes and inactivation of tumor suppressor genes. In our initial investigation, we found that the cells arising from human embryonic muscle could spontaneously transform into malignancy in vitro and we obtained 6 immortalized cell lines. In this study, polymerase chain reaction (PCR) was used to assay several tumor suppressor genes of these cell lines, and homozygous deletions within chromosomal band 9p2l including MTAP (methylthioadenosine phosphorylase), p16 and p15 were detected. PCR products of p53 exons 7 and 8 of these novel tumor cell lines were assayed by sequencing, and the results showed high prevalence of mutations in these regions, the mutation rate reached as high as 8% in exon 7 and 14% in exon 8, and all of them were point mutations, the intron 7 changed more significantly, including piece deletion, insertion, frameshift and point mutation, it showed almost no similarity to that of the wt p53 sequence, that was totally different from other p53 mutation data published. All the mutation sequences were identical in 6 cell lines, this suggest that there may be a common mutation mechanism and strong selective advantage in these novel tumor cell lines over long-term culture. In conclusion, our research shows that the inactivation of tumor suppressor genes may play an important role in the process of malignant transformation of embryonic muscle cells in vitro.

[Etiological hypothesis on five cases of elastofibroma dorsi]

Elastofibroma dorsi is a rare benign lesion of the soft tissue of the thoracic wall, usually located in the subscapular region. It occurs mostly in elderly women patients. This lesion usually arises in right region but it can also be bilateral. Even if the pathogenesis is still unknown, it is considered that "rubbing" of the scapula against the thorax wall could determine growth of the elastofibroma. The differential diagnosis from sarcoma is required but the typical localization and the MRI suggest the diagnosis which should be confirm with the histological exam. The Authors present their experience on five patients, with a median age of 64, affected by elastofibroma dorsi. In two cases, a builder and an obstetrician, the lesion was bilateral; in the other three cases, two teachers and a notary, the lesion are right-sided. A thorax computed tomography (CT) revealed a lesion with heterogeneous density, and the magnetic resonance imaging (MRI) , shows intralesional areas of medium and high intensity signals in the tissue with low intensity in both T12 and T2-sequences. The patient underwent surgery and diagnosis was confirmed by the histological exam. Prevalence of the right localization reported in literature, the correlation between the job of the patients and the lesion localization, more evident in the women, confirmed, according to the other Authors, the etiological hypothesis which considers the lesion as a proliferative response of the connective tissue to the repeated mechanical stress which excessive elastic fibrollogenesis probably due to genetic predisposition.

Dystrophin-deficient mdx mice display a reduced life span and are susceptible to spontaneous rhabdomyosarcoma

Duchenne muscular dystrophy (DMD) is the most common, lethal genetic disorder of children. A number of animal models of muscular dystrophy exist, but the most effective model for characterizing the structural and functional properties of dystrophin and therapeutic interventions has been the mdx mouse. Despite the approximately 20 years of investigations of the mdx mouse, the impact of the disease on the life span of mdx mice and the cause of death remain unresolved. Consequently, a life span study of the mdx mouse was designed that included cohorts of male and female mdx and wild-type C57BL/10 mice housed under specific pathogen-free conditions with deaths restricted to natural causes and with examination of the carcasses for pathology. Compared with wild-type mice, both mdx male and female mice had reduced life spans and displayed a progressively dystrophic muscle histopathology. Surprisingly, old mdx mice were prone to develop muscle tumors that resembled the human form of alveolar rhabdomyosarcoma, a cancer associated with poor prognosis. Rhabdomyosarcomas have not been observed previously in nontransgenic mice. The results substantiate the mdx mouse as an important model system for studies of the pathogenesis of and potential remedies for DMD.

Recognition of Li Fraumeni syndrome at diagnosis of a locally advanced extremity rhabdomyosarcoma

A contemporaneous presentation of a second breast cancer in a mother and an extremity rhabdomyosarcoma (RMS) in her daughter led to the diagnosis of the Li Fraumeni syndrome (LFS). Although the association between LFS and RMS in young patients is well recognised 1 there are no guidelines as to how this knowledge should influence the optimal management of these patients. After reviewing the literature about the natural history of the LFS 2, the incidence of second malignancy (SMN) in RMS survivors 3-6 and the management of extremity RMS 7-9, we are concerned that contemporary RMS treatment, combining non-mutilating surgery with chemoradiotherapy, may be associated with an excessive SMN risk in LFS patients with advanced RMS. We question whether treatment should be individualised and, where possible and acceptable to the family, measures such as amputation should be the considered to attain local control for LFS patients with RMS as this will avoid the need for local radiotherapy without compromising long-term function and quality of life 10.

Regularly methylated novel pro-apoptotic genes associated with recurrence in transitional cell carcinoma of the bladder

Epigenetic silencing of tumor suppressor genes by promoter hypermethylation has been shown for a variety of genes in bladder cancer. Various p53 target genes have been investigated, but only few demonstrated promoter hypermethylation when semiquantitative detection methods were applied. To address to the question whether promoter methylation of novel p53 effector genes is a common event in transitional cell carcinoma of the bladder, we selected the p53 target genes apoptotic protein-activating factor (APAF-1), Caspase 8 (CASP-8), death-associated protein kinase, (DAPK-1) and insulin-like growth-factor-binding protein-3 (IGFBP-3), performing quantitative methylation-specific real-time PCR. The individual level of methylation (normalized index of methylation) was correlated with clinicopathological features as well as the biological behavior of the superficial and muscleinvasive tumors. Tissue was obtained from 110 tumor patients and 20 patients without urological malignancy. The median follow-up of the tumor patients was 52 months. Hypermethylation of the promoter region in tumor specimens was common for APAF-1 (100%), DAPK-1 (74%) and IGFBP-3 (66%), but not for CASP-8 (3.6%). It was seen less frequently and with undetectable or low methylation levels in the normal urothelium group. The APAF-1 methylation levels significantly correlated with tumor stage and tumor grade. The APAF-1 and IGFBP-3 methylation levels were able to separate tumors with higher recurrence risk from low-risk tumors in nonmuscleinvasive and muscleinvasive tumors. In multivariate analysis, APAF-1 and IGFBP-3 methylation levels were independent prognostic markers for recurrence in superficial bladder tumors. This study provides new insights into the role of promoter methylation of selected p53 target genes. The extent of promoter methylation of specific genes offers additional prognostical information and is associated with the outcome in patients with nonmuscleinvasive and muscleinvasive bladder cancer.

Down-regulation of c-Myc following MEK/ERK inhibition halts the expression of malignant phenotype in rhabdomyosarcoma and in non muscle-derived human tumors

Background

Expression of c-myc proto-oncogene is inappropriate in a wide range of human tumors, and is a downstream target of Ras/Raf/ERK pathway, which promotes c-Myc stability by enhancing c-Myc expression and activity.

The aim of this study was to investigate whether the oncogenic phenotype in the human muscle-derived Rhabdomyosarcoma (RD) cell line and in non muscle-derived human tumor cell lines (SW403, IGR39 and PC3) can be blocked by disrupting the c-Myc pathway either by means of pharmacological MEK/ERK inhibition or by direct inactivation of the c-Myc protein.

Results

We demonstrate that, in all the tumor cell lines used, the MEK/ERK inhibitor U0126 rapidly induces c-Myc de-phosphorylation, which is followed by a marked reduction in its expression level, by inhibition of proliferation and by reversion of anchorage-independent growth. These data suggest that the targeting of pathways controlling c-Myc expression or stability reverses deregulated growth of different tumor-derived cell lines. Indeed, in RD cells, we found a marked down-regulation of cyclins E2, A and B and CDK2, all of which are known to be targets of c-Myc. Moreover, ectopic MadMyc chimera, a c-Myc function antagonist, causes dramatic growth arrest, CDK and cyclin modulation as well as inhibition of anchorage-independent growth in RD cells, as occurs in U0126-treated cells. In particular, we found that the mere inhibition of c-Myc by MadMyc chimera rescues the myogenic program, MHC expression and the acquisition of the myogenic-like phenotype in RD cells.

Conclusion

Our data provide evidence of the key role played by the MEK/ERK pathway in the growth arrest and transformation phenotype of Rhabdomyosarcoma and of non muscle-derived tumor cell lines. In fact, MEK/ERK inhibitor, U0126, induces growth arrest, anchorage-dependent growth of these cell lines. In addition, the results of this study demonstrate that the direct inactivation of c-Myc by Mad/Myc chimera rescues myogenic program and leads to the reversal of the Rhabdomyosarcoma phenotype. In conclusion these data strongly suggest that the targeting of c-Myc by means of the MEK inhibitor can be tested as a promising strategy in anti-cancer therapy.

Activating Gs a mutation rarely occurs in musculoskeletal tumors other than fibrous dysplasia

BACKGROUND

Activating Gs a mutations have been identified in most instances of fibrous dysplasia (FD). This mutation leads to consistently elevated intracellular cyclic adenosine monophosphate (cAMP) levels, with various biological consequences. The development of secondary sarcoma in FD is a rare but well-established phenomenon. This finding raised the possibility that a common gene mutation exists in these tumors.

MATERIALS AND METHODS

The expression of the Gs a mutation was examined in 16 cell lines and 173 musculoskeletal tumor tissues, including 13 cases of FD, via RT-PCR and sequence analysis.

RESULTS

No expression of a Gs a mutation was detected in any cell line or clinical tissue sample, excluding FD tissues. Direct sequence analysis demonstrated results identical to those of RT-PCR.

CONCLUSION

Activating Gs a mutation rarely occurs in musculoskeletal tumors other than FD. The occurrence of most sarcomas displays no correlation with Gs a mutations.

Rhabdomyosarcoma: molecular diagnostics of patients classified by morphology and immunohistochemistry with emphasis on bone marrow and purged peripheral blood progenitor cells involvement

Two histologically distinct subtypes of rhabdomyosarcomas (RMS), embryonal and alveolar, are different in many aspects, such as age distribution, primary site, and clinical outcome. We analyzed a group of 30 patients with RMS. The aim was to broaden the spectrum of diagnostic tools in evaluating the primary tumors, their recurrences and/or metastases, and to extend the diagnostic boundary to bone marrow and purged peripheral progenitor blood cell samples. We have performed the RT-PCR assay to analyze RMS for the presence of expression of MyoD1 gene and for the presence of chimeric transcripts PAX3/FKHR or PAX7/FKHR. MyoD1 gene expression was found in all 30 patients in samples from primary tumors. The chimeric transcripts PAX/FKHR were identified in 13 of 15 patients with alveolar RMS. Furthermore, the fusion transcript PAX7/FKHR was identified in 2 of 15 patients with RMS classified as embryonal by histology. Bone marrow samples (12) and peripheral blood progenitor cell specimens (13) in ten patients were examined by RT-PCR. We were able to identify 7 patients with bone marrow involvement and/or with contamination of peripheral blood progenitor cells by the tumor cells. We demonstrate that employing molecular diagnostics has an impact on staging, therapy monitoring and recognition of malignant cells at the tumor resection margins.

Molecular cytogenetic characterization of tenosynovial giant cell tumors

Tenosynovial giant cell tumor (TSGCT) is a disease of disputed etiology and pathogenesis. Some investigations indicate a neoplastic origin of the tumors; others indicate that they are polyclonal and inflammatory. The cytogenetic and molecular genetic features of TSGCTs are largely unknown, as only some 20 localized and 30 diffuse tumors with cytogenetic aberrations have been reported. The most common karyotypic aberrations have been trisomy for chromosomes 5 and 7 and translocations involving chromosomal area 1p11-13. We decided to screen the genomes of TSGCTs by comparative genomic hybridization (CGH) to perform interphase fluorescence in situ hybridization (IP-FISH), looking for numerical aberrations of chromosomes 1, 5, and 7, and to analyze the tumors for microsatellite instability. Except for two diffuse TSGCTs that came fresh to us, and which, by karyotyping, exhibited t(1;22)(p13;q12) and a t(1;1)(q21;p11) and +7, respectively, all studies had to be performed on formalin-fixed, paraffin-embedded material. DNA was extracted from 51 localized and nine diffuse TSGCTs. CGH was successful for 24 tumors, but none of them showed copy number changes. The IP-FISH studies showed trisomy 7 in 56% of the tumors (15/27), whereas chromosomes 1 and 5 seemed to be disomic in all TSGCTs. All informative tumors were wild-type by microsatellite instability analysis.

A reciprocal t(4;9)(q31;p22) in a solitary neurofibroma

Cytogenetic reports of solitary neurofibromas are rare and, to our knowledge, no clonal reciprocal translocations have been reported in these tumors. Reciprocal chromosome translocations have been identified in a number of solid tumors and can have both diagnostic and prognostic significance. We report the first case of a solitary circumscribed neurofibroma with a (4;9)(q31;p22) balanced reciprocal translocation as the sole cytogenetic abnormality.

Giant cell tumours of the tendon sheath: lack of correlation between nm23-H1 expression and recurrence

Some authors attribute recurrences of giant cell tumours to biological factors which are only expressed in some tumours. Grover et al. (1998) suggested that the risk for recurrence is associated with the down-regulation of the nm23-H1 gene. We reviewed the charts of the 154 patients operated on for giant cell tumours of the tendon sheath and selected a group of patients with recurrence (ten cases) and a group of patients who did not have a recurrence after a minimum follow-up of 3 years (13 cases). Immunohistochemical detection of nm23-H1 was performed blindly of the clinical outcome on the paraffin-embedded specimens of these patients and no correlation was found between nm23-H1 expression and the risk for recurrence.

CGH analysis shows genetic similarities and differences in atypical fibroxanthoma and undifferentiated high grade pleomorphic sarcoma

BACKGROUND

Atypical fibroxanthoma (AFX) and undifferentiated high grade pleomorphic sarcoma (UpS) are histologically very similar, if not identical. However, they differ significantly in clinical outcome.

MATERIALS AND METHODS

We used comparative genomic hybridization (CGH) to screen 24 AFX and 12 UpS for genomic alterations.

RESULTS

DNA copy number changes were observed in 20/24 AFX and in all UpS. The most frequent alterations occurring with comparable frequency in both tumors were deletions on chromosomes 9p and 13q. We also detected statistically significant differences of genetic alterations between the two tumors concerning deletions on 1q, 3p, 5q, 11p, 11q, gains on 7q, 12q and high level gains on 5p and 11q.

CONCLUSION

Despite their very similar histology, AFX and UpS show clear differences in their genetic alterations. This might contribute to the different biological behavior of the two tumors. On the other hand the similarities in genetic alterations on chromosomes 9p and 13q might suggest a common pathogenetic pathway.

Chemical-specific alterations in ras, p53, and beta-catenin genes in hemangiosarcomas from B6C3F1 mice exposed to o-nitrotoluene or riddelliine for 2 years

The most prominent neoplastic lesions in mice in the 2-year studies of o-nitrotoluene and riddelliine were hemangiosarcomas. Fifteen o-nitrotoluene-induced hemangiosarcomas of the skeletal muscle, subcutaneous tissue, and mesentery; 12 riddelliine-induced hemangiosarcomas of the liver; and 15 spontaneous subcutaneous hemangiosarcomas were examined for genetic alterations in ras, p53, and beta-catenin genes. Mutations in at least one of these genes were identified in 13 of 15 (87%) of the o-nitrotoluene-induced hemangiosarcomas with missense mutations in p53 exons 5-8 detected in 11 of 15 (73%) of these neoplasms. Seven of 15 (47%) hemangiosarcomas from mice exposed to o-nitrotoluene had deletions at exon 2 splice sites or smaller deletions in the beta-catenin gene. K-ras mutation was detected in only 1 of the 15 (7%) o-nitrotoluene-induced hemangiosarcomas. In contrast to the o-nitrotoluene study, 7/12 (58%) riddelliine-induced hemangiosarcomas had K-ras codon 12 GTT mutations and, when screened by immunohistochemistry, 9/12 (75%) had strong staining for the p53 protein in malignant endothelial cells, the cells of origin of hemangiosarcomas. Riddelliine-induced hemangiosarcomas were negative for the beta-catenin protein. Spontaneous hemangiosarcomas from control mice lacked both p53 and beta-catenin protein expression and ras mutations. Our data indicated that p53 and beta-catenin mutations in the o-nitrotoluene-induced hemangiosarcomas and K-ras mutations and p53 protein expression in riddelliine-induced hemangiosarcomas most likely occurred as a result of the genotoxic effects of these chemicals. It also suggests that these mutations play a role in the pathogenesis of the respective hemangiosarcomas in B6C3F1(1) mice.

11q13 alterations in two cases of hibernoma: large heterozygous deletions and rearrangement breakpoints near GARP in 11q13.5

Hibernomas are rare, benign tumors with a histological appearance resembling that of brown adipose tissue. The diagnosis of hibernomas may be difficult because some of them contain only a small number of the characteristic multivacuolated fat cells and can be mistakenly classified as well-differentiated liposarcomas. Cytogenetic information has been reported for 10 cases, showing that these tumors are characterized by structural rearrangements involving 11q13. Previous fluorescence in situ hybridization (FISH) studies revealed consistent and sometimes cryptic losses of the MEN1 region in 11q13.1. Here, we describe the molecular cytogenetic analysis of two new hibernoma cases. Both tumors showed complex rearrangements, simultaneously including translocations, inversions, and deletions affecting the pair of chromosomes 11. The translocation partners were chromosome 5 in one case and chromosomes 16 and 22 in the other case. The 11q13 region was concomitantly rearranged on both chromosomes 11. FISH studies revealed large heterozygous deletions within the 11q13 band, from 11q13.1 to 11q13.5. Genes such as PYGM, MEN1, CCND1, FGF3, ARIX, and GARP were deleted, showing that the size of the 11q13 altered region was larger than previously reported. Furthermore, both tumors had breakpoints in 11q13.5, one of them in the immediate proximity of the GARP gene. Our results suggest that rearrangements of GARP or a neighboring gene may be important for the pathogenesis of hibernomas.

[Neurectodermal differentiation of extraskeletal myxoid chondrosarcoma: a classical feature?]

Extraskeletal myxoid chondrosarcoma (EMC) is a phenotypically and genotypically distinct entity with a protracted course. A documented case of an extraskeletal myxoid chondrosarcoma characterized by a t(9; 17) (q22; q11) translocation with a neuroendocrine and neural differentiation is reported.

Development of rhabdomyosarcoma in HER-2/neu transgenic p53 mutant mice

Rhabdomyosarcomas derive from the skeletal muscle lineage and harbor a variety of genetic and molecular lesions. However, it is not clear which molecular alterations have a pathogenetic role. We show that activation of the HER-2/neu oncogene coupled with inactivation of the oncosuppressor gene p53 causes rhabdomyosarcoma in mice. At the age of 11-21 weeks, all male mice carrying both genetic lesions developed embryonal rhabdomyosarcomas expressing desmin, myosin, and insulin-like growth factor-II, in the genitourinary tract. Our findings led to the hypothesis that the interaction between HER family genes and the p53 pathway might be involved in the origin of human rhabdomyosarcoma.

Late relapse of adrenocortical carcinoma in Beckwith-Wiedemann syndrome. Clinical, endocrinological and genetic aspects

We report on a girl with an unusual Beckwith-Wiedemann syndrome (BWS) and hemihypertrophy, who developed an adrenocortical carcinoma with atypical clinical behaviour. At 4 y of age the girls was admitted to hospital with cushingoid features, virilization, increased excretion of steroids and low serum ACTH. A right-sided adrenocortical carcinoma was removed. At age 12.5 y the cushingoid features reappeared together with a tumour in the left thigh. A CT scan of the thorax and abdomen revealed pulmonary metastasis only. Corticosteroid excretion was increased and serum ACTH level suppressed. The femoral and the pulmonary metastases were removed and histology showed adrenocortical carcinoma. Excretion of corticosteroids subsequently normalized. Meningeal and pulmonary metastases with similar histologies appeared one year later with normal hormone values. Twenty-two months after the recurrence the girl died of an intracranial metastasis. Southern blot analysis of the LITI transcript in the KvLQT1 gene in the BWS region on chromosome 11p15 revealed hypomethylation of the maternal allele.

CONCLUSION

Adrenocortical carcinoma in childhood may recur years after onset and at rare sites and hormonal levels may be an insufficient indicator of small metastases.

Infiltrating intramuscular lipoma of the temporal muscle. A case report with molecular cytogenetic analysis

Intramuscular lipomas are uncommon benign mesenchymal tumors which infiltrate skeletal muscle and are exceedingly rare in the head and neck region. Because of the infiltrating nature of the lesion and a high propensity for recurrence, they are sometimes difficult to distinguish from well-differentiated liposarcomas (WDLS). We report, the first case of an infiltrating lipoma of the temporal muscle in a 62-year-old white man who presented with a slow growing mass in the left temporal region. The histopathological examination showed diffuse infiltration of the striated muscle fibers by mature adipocytes. There were no lipoblasts or cells with atypical nuclei as described in WDLS. We performed interphase fluorescence in situ hybridization (FISH) analyses using painting probes for chromosome 12 and a specific probe for the MDM2 gene and comparative genomic hybridization. The results did not identify MDM2 or 12q amplification and therefore confirmed the benign nature of the lesion.

Studies on the molecular pathogenesis of extraskeletal myxoid chondrosarcoma-cytogenetic, molecular genetic, and cDNA microarray analyses

Extraskeletal myxoid chondrosarcomas (EMCs) are characterized by recurrent chromosome translocations resulting in fusions of the nuclear receptor TEC to various NH(2)-terminal partners. Here we describe the phenotypic, cytogenetic, and molecular genetic characteristics of a series of 10 EMCs. Using spectral karyotyping and fluorescence in situ hybridization, clonal chromosome abnormalities were detected in all but one tumor. A t(9;22)(q22;q12) translocation was found in three cases; a del(22)(q12-13)in one case; and variant translocations, including t(9;17)(q22;q11-12), t(7;9;17)(q32;q22;q11), and t(9;15)(q22;q21), were detected in one case each. Recurrent, secondary abnormalities, including trisomy 1q, 7, 8, 12, and 19, were found in seven tumors. All tumors contained translocation-generated or cryptic gene fusions, including EWS-TEC (five cases, of which one was a novel fusion), TAF2N-TEC (four cases), and TCF12-TEC (one case). cDNA microarray analysis of the gene expression patterns of two EMCs and a myxoid liposarcoma reference tumor revealed a remarkably distinct and uniform expression profile in both EMCs despite the fact that they had different histologies and expressed different fusion transcripts. The most differentially expressed gene in both tumors was CHI3L1, which encodes a secreted glycoprotein (YKL-40) previously implicated in various pathological conditions of extracellular matrix degradation as well as in cancer. Our findings suggests that EMC exhibits a tumor-specific gene expression profile, including overexpression of several cancer-related genes as well as genes implicated in chondrogenesis and neural-neuroendocrine differentiation, thus distinguishing it from other soft tissue sarcomas.

PKCalpha-mediated ERK, JNK and p38 activation regulates the myogenic program in human rhabdomyosarcoma cells

We have previously suggested that PKCalpha has a role in 12-O-Tetradecanoylphorbol-13-acetate (TPA)-mediated growth arrest and myogenic differentiation in human embryonal rhabdomyosarcoma cells (RD). Here, by monitoring the signalling pathways triggered by TPA, we demonstrate that PKCalpha mediates these effects by inducing transient activation of c-Jun N-terminal protein kinases (JNKs) and sustained activation of both p38 kinase and extracellular signal-regulated kinases (ERKs) (all referred to as MAPKs). Activation of MAPKs following ectopic expression of constitutively active PKCalpha, but not its dominant-negative form, is also demonstrated. We investigated the selective contribution of MAPKs to growth arrest and myogenic differentiation by monitoring the activation of MAPK pathways, as well as by dissecting MAPK pathways using MEK1/2 inhibitor (UO126), p38 inhibitor (SB203580) and JNK and p38 agonist (anisomycin) treatments. Growth-arresting signals are triggered either by transient and sustained JNK activation (by TPA and anisomycin, respectively) or by preventing both ERK and JNK activation (UO126) and are maintained, rather than induced, by p38. We therefore suggest a key role for JNK in controlling ERK-mediated mitogenic activity. Notably, sarcomeric myosin expression is induced by both TPA and UO126 but is abrogated by the p38 inhibitor. This finding indicates a pivotal role for p38 in controlling the myogenic program. Anisomycin persistently activates p38 and JNKs but prevents myosin expression induced by TPA. In accordance with this negative role, reactivation of JNKs by anisomycin, in UO126-pre-treated cells, also prevents myosin expression. This indicates that, unlike the transient JNK activation that occurs in the TPA-mediated myogenic process, long-lasting JNK activation supports the growth-arrest state but antagonises p38-mediated myosin expression. Lastly, our results with the MEK inhibitor suggest a key role of the ERK pathway in regulating myogenic-related morphology in differentiated RD cells.

A preclinical model of minimal residual cancer in the muscle highlights challenges associated with adenovirus-mediated p53 gene transfer

PURPOSE

Clinical studies have revealed that tumors may recur at the operative site if radioresistant p53 mutation-positive residual disease remains in the body after treatment. Destruction of these remaining malignant cells, which can be present in both mucosal and deep muscle margins, may be achieved using p53-mediated gene transfer techniques. Most preclinical studies designed to assess the feasibility of harnessing this approach have used s.c. tumor models in nude mice, but it is anticipated that transduction of tumor cells in the muscle in immune-competent hosts may be more difficult.

EXPERIMENTAL DESIGN

To address this point a new rodent model of residual cancer was established implanting PDVC57B tumor cells to create multiple tumor tracts in the muscle of syngeneic immune-competent C57Bl/6 mice. s.c. tumors and a s.c. model of residual disease were used as comparators.

RESULTS

In the s.c. model of residual disease a single administration of 5 x 10(10) viral particles of Ad5CMV-p53 suppressed the growth of encapsulated tumor at the treatment site in six of six animals, but two of these animals had viable nests of tumor outside of the encapsulated zone. However, Ad5CMV-p53 had no apparent effect on tumor cell progression in the model of residual cancer in the muscle. Creating the muscle model of residual cancer with a lower number of cells in the initial inoculum showed that immune-mediated effects, as well as those attributable to the transgene, are important in preventing tumor outgrowth. The frequency of transduction of tumor cells in the muscle, as determined after administration of Ad-beta-galactosidase, was typically <3% and markedly different from the 20% transduction observed for the s.c. tumor model.

CONCLUSIONS

These studies highlight the need to devise strategies to improve delivery of adenovirus-mediated gene transfer to nests of tumor in muscle before this modality is used to treat residual cancer at this site. These may involve approaches such as intravascular delivery, strategies to improve vector diffusion, or combination with chemotherapy or radiotherapy to enhance gene delivery at these less accessible sites of disease.

Translocation of the HMGI-C ( HMGA2) gene in a benign mesenchymoma (chondrolipoangioma)

Mesenchymomas are neoplasms in which there are at least two types of differentiated cells of mesenchymal derivation other than fibrous tissue. Chondrolipoangioma is a rare type of mesenchymoma composed predominantly of cartilage and adipose tissue with vascular elements and myxoid tissue present in lesser proportions. Cytogenetic analysis was performed on a case of chondrolipoangioma and revealed a t(12;15) (q13;q26) as the sole chromosome abnormality in 40 metaphases analyzed. However, using fluorescence in situ hybridization (FISH) analysis, a complex rearrangement was found involving chromosomes 2, 12, and 15, with a cryptic rearrangement of the gene ( HMGI-C; HMGA2) coding for high-mobility group I protein. This finding suggests a role for the HMGI-C gene also in the pathogenesis of this uncommon benign tumor type, in addition to its well-established role in the pathogenesis of common benign tumors such as lipomas, uterine leiomyomas, pulmonary chondroid hamartomas, and endometrial polyps.

Tumor specific gene expression profiles in human leiomyosarcoma: an evaluation of intratumor heterogeneity

Leiomyosarcomas are malignant smooth muscle tumors characterized by a spectrum of histopathologic features and clinical behavior. Gene expression profiling of leiomyosarcomas may identify differential gene signatures that may allow for the clinical stratification of the tumors. Typically, surgical specimens from these tumors are large and manifest a variegated macroscopic appearance. Because of their large size at the time of diagnosis, sufficient tissue is available for regional and clonal heterogeneity assessment. However, if the gene expression profiles of samples taken from different locations in the tumors are drastically different, biologic classification on the basis of random sample analysis may not be adequate. Therefore, to assess intertumor and intratumor heterogeneity, the authors performed a gene expression study using leiomyosarcoma specimens from three excised sarcomas from an equal number of different patients. Comparisons between tumor and normal samples from the three patients as well as between carefully mapped peripheral and core specimens from the same tumor (excised from one of the patients), were performed. Analysis of the expression profiles demonstrated minimal intratumor variations compared with intertissue variations, indicating homogeneous tumor specific gene expression profiles. The authors also identified genes that are expressed differentially in tumor and normal tissue.

Loss of heterozygosity of chromosome 16q in gallbladder carcinoma

BACKGROUND

The present study was planned to investigate cumulative genetic changes during development and progression of gallbladder carcinoma (GBC) in clinical patients.

MATERIALS AND METHODS

We examined GBC DNA from resected tissue isolated from 56 cases of GBC for loss of heterozygosity (LOH) at six loci on five chromosomal arms (1p36, 9p21, 13q14, 16q24, 17p13), using highly polymorphic microsatellite markers.

RESULTS

High incidences of LOH at 1p36 (19/36: 53%), 9p21 (12/32: 38%), 13q14 (20/36: 56%), 16q24 (31/54: 61%), and 17p13 (15/36: 42%) were detected. When comparing genetic features with clinicopathological stages of these tumors, it appeared that only LOH at 16q24 had a high incidence (5/6: 83%) at an early stage (T1a: tumor invades lamina propria) of the disease, although large numbers of LOH were found on all chromosomal arms in tumors of more advanced stages (T1b, T2, T3, and T4).

CONCLUSION

These results suggested that the putative tumor suppressor gene on 16q24 may be strongly related to an early step of carcinogenesis in GBC and that GBC acquires a high malignant potential when the tumor invades the muscle layer.