Major form of NUP98/HOXC11 fusion in adult AML with t(11;12)(p15;q13) translocation exhibits aberrant trans-regulatory activity

HOXC11 drives lung adenocarcinoma progression through transcriptional regulation of SPHK1

Lung adenocarcinoma (LUAD) is a fatal threat to human health, while the mechanism remains unclear, and the therapy brings limited therapeutic effects. Transcription factor Homeobox C11 (HOXC11) was previously proved to be related to hind limbs and metanephric development during the embryonic phase, and its role in tumors has been gradually recognized. Our study found that HOXC11 overexpressed in LUAD and was associated with worse overall survival. Moreover, its expression in lung cancer was regulated by IκB kinase α (IKKα), a pivotal kinase in NF-κB signaling, which was related to the ubiquitination of HOXC11. We further proved that HOXC11 could enhance the ability of proliferation, migration, invasion, colony formation, and the progression of the cell cycle in LUAD cells. Meanwhile, it also accelerated the formation of subcutaneous and lung metastases tumors. In contrast, loss of HOXC11 in LUAD cells significantly inhibited these malignant phenotypes. At the same time, HOXC11 regulated the expression of sphingosine kinase 1 (SPHK1) by directly binding to its promoter region. Therefore, we conclude that HOXC11 impacts the development of LUAD and facilitates lung cancer progression by promoting the expression of SPHK1.

Inherited heterozygous Fanconi anemia gene mutations in a therapy-related CMML patient with a rare NUP98-HOXC11 fusion: A case report

Fanconi anemia (FA) genes play critical roles in the repair of DNA lesions. Non-FA (or underlying FA) patients harboring heterozygous germline FA gene mutations may also face an increased risk of developing bone marrow failure, primary immunodeficiency disease, and hereditary cancer predisposition syndromes. We report a female patient who suffered from ovarian cancer at 50 years of age. During the initial treatment, six cycles of docetaxel and carboplatin (DC) combination chemotherapy were administered followed by two cycles of docetaxel maintenance therapy. Then, she received a routine follow-up every 3 months for the next 3 years, and all the results of the examination and laboratory tests were normal. Unfortunately, at 54 years of age, she developed a secondary cancer of therapy-related (t-) chronic myelomonocytic leukemia (t-CMML). After two courses of a highly intensive induction chemotherapy regimen with DAC (decitabine) and HAA (homoharringtonine, cytarabine), the patient suffered from severe and persistent bone marrow failure (BMF). Targeted next-generation sequencing (NGS) of a panel of 80 genes was performed on her initial bone marrow aspirate sample and identified PTPN11, NRAS, and DNMT3A somatic mutations. In addition, RNA sequencing (RNA-seq) revealed a rare NUP98-HOXC11 fusion. Whole-exome sequencing (WES) verified RAD51C, BRIP1, PALB2, and FANCG heterozygous germline mutations of the FA pathway, which were further confirmed in buccal swab samples by Sanger sequencing. For this patient, we hypothesized that an altered FA pathway resulted in genomic instability, hypersensitivity to DNA-crosslinking agents or cytotoxic chemotherapeutics, and unsuccessful DNA damage repair. Consequently, she developed ovarian cancer and secondary t-CMML and then suffered from BMF and delayed post-chemotherapy bone marrow recovery after several chemotherapy courses. This case highlights the importance of genetic counseling in patients with hematopoietic neoplasms with high clinical suspicion for carrying cancer susceptibility gene mutations, which require timely diagnosis and personalized management.

HOXC11 positively regulates the long non-coding RNA HOTAIR and is associated with poor prognosis in colon adenocarcinoma

Colorectal cancer ranks third in terms of incidence and second in terms of mortality worldwide. The homeobox transcript antisense intergenic RNA (HOTAIR), which was found to be located on the antisense chain of the homeobox C (HOXC) gene cluster, is a long non-coding RNA involved in multiple types of tumors. The role of HOXC11 in tumors remains unclear. Reverse transcription-quantitative PCR was performed to detect the expression level of HOXC11 in colon adenocarcinoma. Cell proliferation and invasion were assessed. RNase protection assay was used to test the possibility of RNA duplex formation. The increased expression and co-expression trend of HOXC11 and HOTAIR were identified in multiple types of cancer from The Cancer Genome Atlas and the results were validated in 12 colon adenocarcinoma and paired non-tumor tissue samples. The expression of HOXC11 and HOTAIR was found to be associated with poor prognosis in colon adenocarcinoma and kidney renal clear cell carcinoma. Furthermore, HOXC11 was found to positively regulate HOTAIR by RNA duplex formation and promoted the proliferation and invasion of colon adenocarcinoma cells.

HOXC11 Expression Is Associated with the Progression of Colon Adenocarcinoma and Is a Prognostic Biomarker

This study aimed to evaluate the role of HOXC11 in progression and prognosis in colon adenocarcinoma (COAD) patients. The COAD patient data were downloaded from "The Cancer Genome Atlas (TCGA)" database. The Wilcoxon rank-sum test or Kruskal-Wallis test was used to analyze the correlation between HOXC11 expression and clinicopathologic characteristics. The significance of difference in overall survival between different groups was determined by log-rank test. The HOXC11 expression was verified from mRNA and protein level by conducting real-time quantitative PCR, Western blot, and immunohistochemistry analysis. Significantly enriched Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways were screened after gene set enrichment analysis. As a result, high HOXC11 expression was closely related to the occurrence of COAD based on the data in TCGA, which was then successfully validated in cell lines and clinical tissues. Enhanced HOXC11 expression was significantly associated with tumor-node-metastasis (TNM) and M stage. Prognosis of highly expressed HOXC11 COAD patients was significantly worse than those with low HOXC11 expression. GRAFT_VERSUS_HOST_DISEASE and other signaling pathways were significantly activated in high HOXC11 expression COAD patients. In conclusion, high expression of HOXC11 was closely associated with the progression of COAD, and HOXC11 was a promising prognostic biomarker in COAD patients.

Cryptic t(15;17) acute promyelocytic leukemia with a karyotype of add(11)(p15) and t(13,20)- A case report with a literature review

Most acute promyelocytic leukemias (APL) are characterized by reciprocal translocations t(15;17)(q22;21), which results in the fusion of the promyelocytic leukemia protein (PML) gene at 15q22 with retinoic acid receptor a (RARα) gene at 17q21. However, several complex variant translocations also have been reported. Here, we report a 62-year-old man with typical morphology and clinical features of APL with a complex karyotype including add(11)(p15) and t(13;20)(q12;q11.2) without typical t(15;17) assayed by the G-banding analysis. The fluorescence in situ hybridization with a PML/RARα dual-color DNA probe showed an atypical fusion signal, quantitative real-time polymerase chain reaction analysis showed PML/RARα fusion transcripts, and NGS detected FLT3, WT1, and KRAS mutations. The patient achieved complete remission after treatment with conventional chemotherapy combined with all-trans retinoic acid (ATRA) and arsenic trioxide (ATO). Although the mechanism of this kind of cryptic variant remains unknown, we conclude that the cryptic PML/RARα fusion with add(11)(p15) and t(13;20)(q12;q11.2) seems not to alter the effectiveness of chemotherapy combined with ATRA and ATO.

Acute monocytic leukaemia with t(11; 12) (p15; q13) chromosomal changes: A case report and literature review

Acute myeloid leukaemia (AML) is a type of heterogeneous disease derived from haematopoietic stem cells. Cytogenetic characterisation is essential for diagnosis and prognosis stratification. Here, we present the case of a 43-year-old female diagnosed with leukaemia, who demonstrated a rare chromosomal change of t(11; 12) (p15; q13) along with a positive FLT3-ITD mutation. The patient had a white blood cell count of 76.41×10⁹/l. Bone marrow morphology revealed that monoblasts accounted for 25.5% of cells, and premonocytes accounted for 49.0%. This patient strongly responded to idarubicin and Ara-c (cytarabine) chemotherapy, which rapidly eliminated the leukaemia cell clones. However, the proliferation rate of the leukaemia cells was high during the intermission of chemotherapy. Subsequently, following two courses of chemotherapy, full haematological remission could not be attained. AML patients with t(11; 12) (p15; q13) combined with FLT3-ITD mutations are expected to have a short life expectancy; however, early haematopoietic stem cell transplantation therapy may improve the treatment outcome for these patients.

Nucleoporin Gene Fusions and Hematopoietic Malignancies

Nuclear pore complexes (NPCs) are the sole gateways between the nucleus and the cytoplasm of eukaryotic cells and they mediate all macromolecular trafficking between these cellular compartments. Nucleocytoplasmic transport is highly selective and precisely regulated and as such an important aspect of normal cellular function. Defects in this process or in its machinery have been linked to various human diseases, including cancer. Nucleoporins, which are about 30 proteins that built up NPCs, are critical players in nucleocytoplasmic transport and have also been shown to be key players in numerous other cellular processes, such as cell cycle control and gene expression regulation. This review will focus on the three nucleoporins Nup98, Nup214, and Nup358. Common to them is their significance in nucleocytoplasmic transport, their multiple other functions, and being targets for chromosomal translocations that lead to haematopoietic malignancies, in particular acute myeloid leukaemia. The underlying molecular mechanisms of nucleoporin-associated leukaemias are only poorly understood but share some characteristics and are distinguished by their poor prognosis and therapy outcome.

A novel NUP98/RARG gene fusion in acute myeloid leukemia resembling acute promyelocytic leukemia

Chromosomal translocations in hematological malignancies often result in novel fusion chimeric genes. We report a case of acute myeloid leukemia with a clonal translocation t(11;12)(p15;q13) displaying morphologic and immunophenotypic features resembling the classical hypergranular subtype of acute promyelocytic leukemia. The gene fused to NUP98 (nucleoporin 98) was detected by comparative genomic hybridization array as the retinoid acid receptor gamma gene (RARG). The involvement of RARG in a chimeric fusion transcript has not been reported previously in human leukemia.

A novel t(5;11)(q31;p15) involving the NUP98 gene on 11p15 is associated with a loss of the EGR1 gene on 5q31 in a patient with acute myeloid leukemia

To date, at least 25 translocations involving the NUP98 gene and different partner genes have been reported in the literature. Here, we describe a novel reciprocal t(5;11)(q31;p15) involving NUP98, as revealed by conventional karyotypic analysis using R-banding technique and fluorescence in situ hybridization (FISH) using a BAC RP11-120E20 probe and whole chromosome paint probes for chromosomes 5 and 11 in a 77-year-old woman who was diagnosed as having de novo acute myeloid leukemia. The patient received two courses of intensive combined chemotherapy but did not reach complete remission. She eventually died from the progressive disease, surviving for only 1 month after diagnosis. FISH analysis using WCP5 together with BAC RP11-878F9 or RP11-155N22 demonstrated that the breakpoint of chromosome 5 is located on 5q31. In addition, the EGR1 gene was unexpectedly found to be lost in the FISH study using EGR1 (red)/D5S23, D5S721 (green) dual-color probe. We supposed that the fusion gene created by t(5;11)(q31;p15) consisting of the NUP98 and its partner gene, as well as the loss of the EGR1 gene, may play a cooperative role in leukemogenesis. The partner gene of NUP98 in t(5;11)(q31;p15) is unclear at this time. Further molecular study is required to identify this partner gene in our patient.

A NUP98-positive acute myeloid leukemia with a t(11;12)(p15;q13) without HOXC cluster gene involvement

We report a case of adult acute myeloid leukemia with a new t(11;12)(p15;q13) underlying a NUP98 rearrangement without HOXC cluster gene involvement. We designed a specific double-color double-fusion FISH assay to discriminate between this t(11;12)(p15;q13) and those producing NUP98-HOXC11 or NUP98-HOXC13. Our fluorescence in situ hybridization (FISH) showed that putative candidate partners mapping 600 kilobases centromeric to HOXC were RARG (retinoic acid receptor gamma), MFSD5 (major facilitator superfamily domain containing 5), and ESPL1 (extra spindle pole bodies homolog 1). It is noteworthy that so far only ESPL1 has been implicated in human cancers. This FISH assay is useful for diagnostic screening of NUP98-positive leukemias.

Acute myeloid leukemia with NUP98-HOXC13 fusion and FLT3 internal tandem duplication mutation: case report and literature review

The NUP98 gene at chromosome band 11p15 is known to be fused to a number of different partners in various hematological malignancies. The most frequently observed fusion partners of NUP98 are the homeobox family of transcriptional factors (HOX genes). We report a case of de novo AML M4 subtype, with a t(11;12)(p15;q13) translocation, generating a NUP98-HOXC13 chimeric transcript. Molecular analysis showed that the exon 16 of NUP98 was fused in frame with exon 2 of HOXC13. The patient was also positive for FLT3 internal tandem duplication (ITD), another molecular marker for the disease. Comparative study of data on the fusion of HOXC cluster and NUP98 gene revealed that it is a rare event, found exclusively in AML patients. To our knowledge, this is the first case of t(11;12)(p15;q13) in de novo AML-M4 in association with FLT3 ITD mutation. Coexistence of NUP98-HOXC13 fusion and FLT3 ITD mutation is likely relevant in the process of leukemogenesis.

Nuclear pore proteins and cancer

Nucleocytoplasmic trafficking of macromolecules, a highly specific and tightly regulated process, occurs exclusively through the nuclear pore complex. This immense structure is assembled from approximately 30 proteins, termed nucleoporins. Here we discuss the four nucleoporins that have been linked to cancers, either through elevated expression in tumors (Nup88) or through involvement in chromosomal translocations that encode chimeric fusion proteins (Tpr, Nup98, Nup214). In each case we consider the normal function of the nucleoporin and its translocation partners, as well as what is known about their mechanistic contributions to carcinogenesis, particularly in leukemias. Studies of nucleoporin-linked cancers have revealed novel mechanisms of oncogenesis and in the future, should continue to expand our understanding of cancer biology.

A new fusion gene NUP98-IQCG identified in an acute T-lymphoid/myeloid leukemia with a t(3;11)(q29q13;p15)del(3)(q29) translocation

NUP98 has been involved in multiple recurrent chromosome rearrangements in leukemia. We identified a novel fusion between NUP98 and IQ motif containing G (IQCG) gene from a de novo acute T-lymphoid/myeloid leukemia harboring t(3;11)(q29q13;p15)del(3)(q29). IQCG has two putative coiled-coil domains and one IQ domain. The FG repeat from NUP98 and the coiled-coil domain from IQCG were retained in the fusion protein. We demonstrated that NUP98-IQCG could form homodimer, heterodimerize with NUP98 or IQCG, bind co-activators and/or co-repressors, and show transcriptional activity in vitro. Expression of NUP98-IQCG inhibited 32Dcl3 cell apoptosis induced by Ara-C, and partially blocked granulocyte differentiation induced by G-CSF. Colony-forming assay and serial replating assays indicated that NUP98-IQCG was able to stimulate proliferation, partially block differentiation of hematopoietic stem/progenitor cells but was unable to confer transformation alone. Taken together, our data indicate that newly identified NUP98-IQCG fusion protein may play an essential role in leukemogenesis, but by itself may not be sufficient to induce leukemia.

Rare t(1;11)(q23;p15) in therapy-related myelodysplastic syndrome evolving into acute myelomonocytic leukemia: a case report and review of the literature

Balanced chromosome rearrangements are the hallmark of therapy-related leukemia that develops in patients treated with topoisomerase II inhibitors. Many of these rearrangements involve recurrent chromosomal sites and associated genes (11q23/MLL, 21q22.3/AML1, and 11p15/NUP98), which can interact with a variety of partner genes. One such rearrangement is the rare t(1;11)(q23;p15), which involves juxtaposition of the homeobox gene PMX1 (PRRX1) and NUP98. We report on an additional patient with t(1;11) who presented with myelodysplastic syndrome (MDS) subsequent to treatment for a pleomorphic liposarcoma. With time, the patient's disorder progressed to acute myelomonocytic leukemia with cytogenetic evidence of clonal evolution. To our knowledge, this is the first report of a patient presenting with a myelodysplastic syndrome with isolated t(1;11) (q23;p15), which evolved into therapy-related acute myeloid leukemia (t-AML). This patient is the third reported with this cytogenetic rearrangement and t-AML, and is compared with the other two reports of t(1;11)(q23;p15).

Analysis of phenotype-genotype connection: the story of dissecting disease pathogenesis in genomic era in China, and beyond

DNA is the ultimate depository of biological complexity. Thus, in order to understand life and gain insights into disease pathogenesis, genetic information embedded in the sequence of DNA base pairs comprising chromosomes should be deciphered. The stories of investigating the association between phenotype and genotype in China and other countries further demonstrate that genomics can serve as a probe for disease biology. We now know that in Mendelian disorders, one gene is not only a dictator of one phenotype but also a dictator of two or more distinct disorders. Dissecting genetic abnormalities of complex diseases, including diabetes, hypertension, mental diseases, coronary heart disease and cancer, may unravel the complicated networks and crosstalks, and help to simplify the complexity of the disease. The transcriptome and proteomic analysis for medicine not only deepen our understanding of disease pathogenesis, but also provide novel diagnostic and therapeutic strategies. Taken together, genomic research offers a new opportunity for determining how diseases occur, by taking advantage of experiments of nature and a growing array of sophisticated research tools to identify the molecular abnormalities underlying disease processes. We should be ready for the advent of genomic medicine, and put the genome into the doctors' bag, so that we can help patients to conquer diseases.

NUP98 rearrangements in hematopoietic malignancies: a study of the Groupe Francophone de Cytogénétique Hématologique

The NUP98 gene is fused with 19 different partner genes in various human hematopoietic malignancies. In order to gain additional clinico-hematological data and to identify new partners of NUP98, the Groupe Francophone de Cytogénétique Hématologique (GFCH) collected cases of hematological malignancies where a 11p15 rearrangement was detected. Fluorescence in situ hybridization (FISH) analysis showed that 35% of these patients (23/66) carried a rearrangement of the NUP98 locus. Genes of the HOXA cluster and the nuclear-receptor set domain (NSD) genes were frequently fused to NUP98, mainly in de novo myeloid malignancies whereas the DDX10 and TOP1 genes were equally rearranged in de novo and in therapy-related myeloid proliferations. Involvement of ADD3 and C6ORF80 genes were detected, respectively, in myeloid disorders and in T-cell acute lymphoblastic leukemia (T-ALL), whereas the RAP1GDS1 gene was fused to NUP98 in T-ALL. Three new chromosomal breakpoints: 3q22.1, 7p15 (in a localization distinct from the HOXA locus) and Xq28 were detected in rearrangements with the NUP98 gene locus. The present study as well as a review of the 73 cases previously reported in the literature allowed us to delineate some chromosomal, clinical and molecular features of patients carrying a NUP98 gene rearrangements.

Trans-Repressive Effect of NUP98-PMX1 on PMX1-Regulated c-FOSGene through Recruitment of Histone Deacetylase 1 by FG Repeats

The formation of fusion genes between NUP98 and members of the HOX family represents a critical factor for the genesis of acute leukemia or acute transformation of chronic myeloid leukemia (CML). To gain insights into the molecular mechanisms underlying the leukemogenesis of NUP98-HOX fusion products, we cloned NUP98-PMX1 from a CML-blast crisis patient with t(1;11) as a secondary chromosomal translocation, and functionally studied the fusion products in detail through various molecular and protein biochemical assays. In addition to many interesting features, we have found that the NUP98-PMX1 fusion protein exerts a repressive effect on PMX1 or serum response factor-mediated c-FOS activation, probably through the recruitment of a common corepressor histone deacetylase 1 by FG domains of the NUP98-PMX1 fusion protein. Moreover, we have provided evidence that the FG domains of NUP98-PMX1 and two other NUP98-containing fusion proteins, i.e., NUP98-HOXA9 and NUP98-HOXC11, all exhibit dual binding ability to both CREB binding protein, a coactivator, and histone deacetylase 1, a corepressor. Accordingly, we have hypothesized that this dual binding activity is shared by most, if not all, NUP98-HOX-involved fusion proteins, enabling these fusion proteins to act as both trans-activators and trans-repressors, and contributing to the genesis of acute leukemia or acute transformation of CML.

Identification ofNUP98 abnormalities in acute leukemia:JARID1A (12p13) as a new partner gene

Chromosome rearrangements are found in many acute leukemias. As a result, genes at the breakpoints can be disrupted, forming fusion genes. One of the genes involved in several chromosome aberrations in hematological malignancies is NUP98 (11p15). As NUP98 is close to the 11p telomere, small translocations might easily be missed. Using a NUP98-specific split-signal fluorescence in situ hybridization (FISH) probe combination, we analyzed 84 patients with acute myeloid leukemia (AML), acute lymphoblastic leukemia, or myelodysplastic syndrome with either normal karyotypes or 11p abnormalities to investigate whether there are unidentified 11p15 rearrangements. Neither NUP98 translocations nor deletions were identified in cases with normal karyotypes, indicating these aberrations may be very rare in this group. However, NUP98 deletions were observed in four cases with unbalanced 11p aberrations, indicating that the breakpoint is centromeric of NUP98. Rearrangements of NUP98 were identified in two patients, both showing 11p abnormalities in the diagnostic karyotype: a t(4;11)(q1?3;p15) with expression of the NUP98-RAP1GDS1 fusion product detected in a 60-year-old woman with AML-M0, and an add(11)(p15) with a der(21)t(11;21)(p15;p13) observed cytogenetically in a 1-year-old boy with AML-M7. JARID1A was identified as the fusion partner of NUP98 using 3' RACE, RT-PCR, and FISH. JARID1A, at 12p13, codes for retinoblastoma binding protein 2, a protein implicated in transcriptional regulation. This is the first report of JARID1A as a partner gene in leukemia.

Leukemia fusion proteins and co-repressor complexes: changing paradigms

Many cases of acute myelogenous leukemia (AML) are characterized by non-random chromosomal translocations that fuse a DNA-binding protein with a transcriptional regulator, which in turn may aberrantly recruit a co-repressor complex. The similarities in this pattern between different AML chimeric fusions have led to a paradigm that stresses the importance of the co-repressor complex in altering the pattern of expression of genes targeted by the DNA-binding moiety of the fusion. Such findings beg the question of whether the fusion proteins merely serve as anchors to recruit the co-repressor complex or whether they play other significant roles in leukemogenesis. The answers to this question may have therapeutic importance since we now have the ability to target various components of the co-repressor complex, such as the histone deacetylase (HDAC) enzymes. In this Prospect, we wish to highlight some of the complexities and difficulties with the existing molecular paradigm of this challenging group of disorders.

Human genome research in China

Significant progress in human genome research has been made in China since 1994. This review aims to give a brief and incomplete introduction to the major research institutions and their achievements in human genome sequencing and functional genomics in medicine, with emphasis on the "1% Sequencing Project", the generation of single nucleotide polymorphism and haplotype maps of the human genome, disease gene identification, and the molecular characterization of leukemia and other diseases. Chinese efforts towards the sequencing of pathogenic microbial genomes and of the rice (Oryza sativa ssp. Indica) genome are also described.

Analysis of translocations that involve theNUP98 gene in patients with 11p15 chromosomal rearrangements

The NUP98 gene has been reported to be fused with at least 15 partner genes in leukemias with 11p15 translocations. We report the results of screening of cases with cytogenetically documented rearrangements of 11p15 and the subsequent identification of involvement of NUP98 and its partner genes. We identified 49 samples from 46 hematology patients with 11p15 (including a few with 11p14) abnormalities, and using fluorescence in situ hybridization (FISH), we found that NUP98 was disrupted in 7 cases. With the use of gene-specific FISH probes, in 6 cases, we identified the partner genes, which were PRRX1 (PMX1; in 2 cases), HOXD13, RAP1GDS1, HOXC13, and TOP1. In the 3 cases for which RNA was available, RT-PCR was performed, which confirmed the FISH results and identified the location of the breakpoints in patient cDNA. Our data confirm the previous findings that NUP98 is a recurrent target in various types of leukemia.