RANBP2 and CLTC are involved in ALK rearrangements in inflammatory myofibroblastic tumors
ABSTRACT Inflammatory myofibroblastic tumors (IMTs) are rare soft tissue tumors occurring primarily in children and young adults. ALK gene rearrangements have been identified in this neoplasm, with fusion of the ALK gene at 2p23 to a number of different partner genes. Metaphase cytogenetic analyses of these tumors have been relatively few, however, and may help to identify additional variant partners. We report on an IMT from a 2-year-old boy with a karyotype of 45,XY,der(2)inv(2)(p23q12)del(2)(p11.1p11.2),-22. FISH showed ALK-RANBP2 fusion in this tumor. The breakpoint was cloned and the fusion was confirmed, making this the third reported case of IMT with ALK-RANBP2 fusion. In addition, we identified the ALK fusion partner in a previously reported IMT with t(2;17)(p23;q23) as CLTC, a gene reported to be involved in four other IMTs, and showed that the breakpoint involved a novel ALK-CLTC fusion. FISH evaluation of nine other IMTs identified CLTC as the fusion partner in one additional case, but RANBP2 was not involved in the remaining eight IMTs, suggesting that the variant partners involved in ALK rearrangements in IMTs are diverse.
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ABSTRACT: Anaplastic lymphoma kinase 1 (ALK-1) is a member of the insulin receptor tyrosine kinase family. ALK-1 was initially found in anaplastic large cell lymphoma (ALCL). ALK mutations have also been implicated in the pathogenesis of non-small cell lung cancer (NSCLC) and other solid tumors. Multiple small molecule inhibitors with activity against ALK and related oncoproteins are under clinical development. Two of them, crizotinib and ceritinib, have been approved by FDA for treatment of locally advanced and metastatic NSCLC. More agents (alectinib, ASP3026, X396) with improved safety, selectivity, and potency are in the pipeline. Dual inhibitors targeting ALK and EGFRm (AP26113), TRK (TSR011), FAK (CEP-37440), or ROS1 (RXDX-101, PF-06463922) are under active clinical development.Journal of Hematology & Oncology 02/2015; 8(1). DOI:10.1186/s13045-015-0122-8 · 4.93 Impact Factor
Article: Cancer and the nuclear pore complex.[Show abstract] [Hide abstract]
ABSTRACT: The nuclear pore complex (NPC) mediates trafficking between the cytoplasm and nucleoplasm. It also plays key roles in other nuclear processes such as chromatin silencing, transcriptional regulation, and DNA damage repair. Nucleoporins, the structural components of the NPC, have been linked to a multitude of cancers through chromosomal translocations generating fusion proteins, changes in protein expression levels, and single point mutations. Only a small number of nucleoporins have been linked to tumorigenesis thus far, and these proteins-Nup62, Nup88, Nup98, Nup214, Nup358/RanBP2, and Tpr-line the trafficking pathway and are particularly associated with mRNA export. Overexpression of several associated nuclear export factors, most also involved in various stages of mRNA export, has been linked to cancers as well. Some oncogenic nucleoporin mutants are mislocalized to either the cytoplasm or nucleoplasm while others are incorporated into the NPC, and in all these cases they are thought to misregulate signaling pathways and transcription through either altered or diminished nucleoporin functionality. Intriguingly, many viruses target the same cancer-linked nucleoporins, often causing their degradation or mislocalization, implying that these viruses exploit some of the same weaknesses as the oncogenic defects.Advances in Experimental Medicine and Biology 01/2014; 773:285-307. DOI:10.1007/978-1-4899-8032-8_13 · 2.01 Impact Factor