CIC-DUX4 gene fusion, resulting from either a t(4;19) or t(10;19) translocation, is the most common genetic abnormality detected in EWSR1-negative small blue round cell tumors (SBRCTs). Following their discovery it was debated if these tumors should be classified as variants of Ewing sarcoma (i.e. atypical Ewing sarcoma) or as a stand-alone pathologic entity. As such the WHO classification temporarily grouped the CIC-rearranged tumors under undifferentiated sarcomas with round cell phenotype, until further clinical evidence was available. However, most studies reported so far include small series with limited follow-up information which preclude a more definitive assessment. The present work investigates the clinicopathologic features of a large cohort of sarcomas with CIC gene rearrangement, in order to define their clinical presentation, morphologic spectrum, and outcome. Our study further examines the overall survival of the CIC-positive cohort compared to a control group of EWSR1-rearranged Ewing sarcoma matched for age and stage. The study cohort included 115 patients, with a mean age of 32 years and a slight male predominance. Most tumors occurred in the soft tissue (86%), predominantly deep-seated and equally divided among trunk and extremity, followed by visceral locations (12%) and rarely in the bone (3%). Microscopically, most tumors showed round to ovoid cytomorphology but half of the cases showed also focal areas of spindling and epithelioid/rhabdoid phenotype, with frequent myxoid stromal changes. Variable CD99 reactivity was seen in 84% cases, with a diffuse pattern only in 23% of cases, while nuclear WT1 was seen in 92%. A CIC-DUX4 fusion was detected in 57% of cases, with either DUX4 on 4q35 (35%) or on 10q26 in 25 (22%) cases. No FOXO4 gene rearrangements were present in 39 cases tested. Clinical follow-up was available in 57 patients, with a 5-year survival of 43%, which was significantly lower than the 77% 5-year survival in the control Ewing sarcoma group (p=0.002). Our findings show that CIC-DUX4 sarcomas occur most commonly in young adults within the somatic soft tissues, having a wide spectrum of morphology including round, epithelioid and spindle cells, and associated with an aggressive clinical course, with an inferior overall survival compared to Ewing sarcoma. The results support the classification of CIC-rearranged tumors as an independent molecular and clinical subset of SBRCTs distinct from Ewing sarcoma.

Background/Aims-The success of sorafenib in the treatment of advanced hepatocellular carcinoma (HCC) has focused interest on the role of Ras signaling in this malignancy. We investigated the molecular alterations of the Ras pathway in HCC and the antineoplastic effects of sorafenib in combination with rapamycin, an inhibitor of mTOR pathway, in experimental models.Methods-Gene expression (qRT-PCR, oligonucleotide microarray), DNA copy number changes (SNP-array), methylation of tumor suppressor genes (methylation-specific PCR) and protein activation (immunohistochemistry) were analysed in 351 samples. Anti-tumoral effects of combined therapy targeting the Ras and mTOR pathways were evaluated in cell lines and HCC xenografts.Results-Different mechanisms accounted for Ras pathway activation in HCC. H-ras was upregulated during different steps of hepatocarcinogenesis. B-raf was overexpressed in advanced tumors and its expression was associated with genomic amplification. Partial methylation of RASSF1A and NORE1A was detected in 89% and 44% of tumors respectively, and complete methylation was found in 11 and 4% of HCCs. Activation of the pathway (pERK immunostaining) was identified in 10.3% of HCC. Blockade of Ras and mTOR pathways with sorafenib and rapamycin Conclusions-Ras activation results from several molecular alterations, such as methylation of tumor suppressors and amplification of oncogenes (B-raf). Sorafenib blocks signaling and synergizes with rapamycin in vivo, preventing tumor progression. These data provide the rationale for testing this combination in clinical studies.

The genetics of Ewing sarcoma (ES) are characterized by a canonical fusion involving EWSR1 gene and a member of the ETS family of transcription factors, such as FLI1 and ERG. In fact, ERG gene rearrangements represent the second most common molecular alteration, with EWSR1-ERG being identified in 5–10% of cases, while only a handful of reports document a FUS-ERG fusion. In this study, we focus on ES with ERG gene abnormalities, specifically to investigate the prevalence and clinicopathologic features of FUS-ERG fusions in a large cohort of small blue round cell tumors (SBRCTs) and compare to the eight reported FUS-positive ES. Among the 85 SBRCTs tested, seven (8.2%) cases harbored FUS gene rearrangements; six fused to ERG and one with FEV. During this investigation we came across a number of ERG-rearranged ES lacking both EWSR1 and FUS abnormalities by FISH. In one case, RNA sequencing identified an EWSR1-ERG transcript despite the negative EWSR1 rearrangements by FISH. Additional 3-color FISH fusion assay demonstrated the fusion of EWSR1 and ERG signals in all four cases negative for break-apart EWSR1 FISH. These results emphasize a potential pitfall of relying on EWSR1 FISH assay alone for diagnosis of ES. In cases with classic morphology and/or strong CD99 and ERG immunoreactivity, additional molecular testing should be applied, such as ERG FISH or RT-PCR/next generation sequencing, for a more definitive diagnosis. Although our study group is small, there were no differences noted between the clinical, morphologic features and immunoprofile of the different subsets of ERG-rearranged SBRCTs.

The CP-induced changes in histopathologic findings of kidneys were partially reversed by treatment with royal jelly. The results provide further insight into the mechanisms of CP-induced nephrotoxicity and confirm the antioxidant potential of royal jelly.

No abstract