Confirmation of damaging effect of MSH2 c.2634+1G>C mutation on splicing, its classification and implications for counseling Publication date: November 2019 Source: Cancer Genetics, Volume 239 Author(s): Jelena Rakobradović, Ana Krivokuća, Stevo Jovandić, Vesna Kesić, Mirjana Branković-Magić Abstract Introduction Lynch syndrome (LS) is predisposing mainly to colorectal and endometrial carcinomas, but also to urinary tract cancers. LS association with upper urinary tract carcinomas is known, but its association with bladder cancer is not so clear. Confirmation of pathogenicity of detected mutations in LS-associated genes is required for adequate counseling. Material and Methods Tested young female has family history of two early colorectal and two bladder carcinomas. NGS sequencing revealed MSH2 splice site mutation c.2634+1G>C, which was confirmed by Sanger sequencing. MSH2 cDNA part containing potential splicing change was sequenced. in silico softwares were used to predict the effect of detected mutation on splicing and protein structure. ACMG Guidelines were used for mutation classification. Results in silico softwares predict damaging effect of detected mutation on splicing and loss of protein-binding domains. cDNA sequencing confirmed this mutation causes exon 15 excision. ACMG Guidelines classify this mutation as Pathogenic. Discussion MSH2 c.2634+1G>C mutation was not reported previously as LS associated. We confirmed its damaging effect on splicing. in silico tools predict consequent loss of protein domains implicating disrupted protein function. Our results suggest that this mutation should be classified as Pathogenic, and indicate inclusion of bladder cancer in LS cancer spectrum.

Chronic myelomonocytic leukemia with ETV6-ABL1 rearrangement and SMC1A mutation Publication date: October 2019 Source: Cancer Genetics, Volume 238 Author(s): Melissa H. Cessna, Prabakaran Paulraj, Benjamin Hilton, Kianoush Sadre-Bazzaz, Philippe Szankasi, Alice Cluff, Jay L. Patel, Daanish Hoda, Reha M. Toydemir Abstract Chronic myelomonocytic leukemia (CMML) is a rare malignant neoplasm of the blood-forming cells in bone marrow characterized by persistent monocytosis. Although most patients with CMML show clonal genetic aberrations, there is no known cytogenetic or molecular genetic finding that is specific to CMML. We report a patient who had a clinical and morphological presentation consistent with CMML. The genetic work-up showed an ETV6-ABL1 fusion consequent to a 9;12 translocation, and a missense mutation in SMC1A (c.1757G>A, p.Arg586Gln). The SMC1A mutations are recurrent, albeit rare, in myeloid malignancies, without an established clinical significance in CMML. ETV6-ABL1 fusion is a rare but recurrent genetic aberration found in various hematologic malignancies involving both the lymphoid and myeloid lineage, but to the best of our knowledge, CMML is an exceptionally rare presentation of ETV6-ABL1 rearranged neoplasm. ETV6-ABL1 fusion is often formed through complex rearrangements, and usually cryptic by routine G-banded chromosome analysis. The diseases associated with this rearrangement generally have an aggressive course, hence detecting or excluding this rearrangement during diagnostic work-up is critical for treatment planning.

Masked hypodiploidy: Hypodiploid acute lymphoblastic leukemia (ALL) mimicking hyperdiploid ALL in children: A report from the Children's Oncology Group Publication date: October 2019 Source: Cancer Genetics, Volume 238 Author(s): Andrew J. Carroll, Mary Shago, Fady M. Mikhail, Susana C. Raimondi, Betsy A. Hirsch, Mignon L. Loh, Elizabeth A. Raetz, Michael J. Borowitz, Brent L. Wood, Kelly W. Maloney, Leonard A. Mattano, Eric C. Larsen, Julie Gastier-Foster, Eileen Stonerock, Denise Ell, Samir Kahwash, Meenakshi Devidas, Richard C. Harvey, I-Ming L. Chen, Cheryl L. Willman Abstract Hyperdiploidy with greater than 50 chromosomes is usually associated with favorable prognosis in pediatric acute lymphoblastic leukemia (ALL), whereas hypodiploidy with ≤43 chromosomes is associated with extremely poor prognosis. Sometimes, hypodiploidy is “masked” and patients do not have a karyotypically visible clone with ≤43 chromosomes. Instead, their abnormal karyotypes contain 50–78 or more chromosomes from doubling of previously hypodiploid cells. When the hypodiploid and doubled hyperdiploid clones are both present, patients can be identified by traditional test methods [karyotype, DNA Index (DI), fluorescence in situ hybridization (FISH)], but the incidence of masked hypodiploid cases in which only the doubled clone is visible is unknown. We analyzed 7013 patients with B-ALL enrolled in COG AALL03B1 (2003–2011) for whom chromosome studies were available. Of 115 patients with hypodiploidy (25–39 chromosomes), karyotypes of 40 showed only the hypodiploid clone, 47 showed mosaicism with both hypodiploid and hyperdiploid (doubled) karyotypes, and 28 with masked hypodiploidy showed only a hyperdiploid (doubled) clone. Unique karyotypic signatures were identified, and widespread loss of heterozygosity (LOH) was seen in the microsatellite panel for all patients with masked hypodiploidy. An increased awareness of the unusual karyotypic profile associated with a doubled hypodiploid clone and coordinated use of DI, FISH, and LOH studies when indicated can identify patients with masked hypodiploidy and allow appropriate treatment selection.

Telomere length measurement in tumor and non‐tumor cells as a valuable prognostic for tumor progression Publication date: October 2019 Source: Cancer Genetics, Volume 238 Author(s): Fatma Mehrez, Karim Bougatef, Elisa Delle Monache, Ivan Arisi, Luca Proietti-De-Santis, Giorgio Prantera, Lilia Zouiten, Manuela Caputo, Amel Ben Ammar Elgaaied, Silvia Bongiorni Abstract Telomere shortening has been supposed to be implicated in both aging and various human diseases especially carcinogenesis process. This phenomenon can lead to a chromosomal instability, contributing to a cell immortalization and tumor induction. In our study, we analyzed the role of telomere shortening in cancer progression, in Tunisian patients with digestive cancer. We measured the absolute telomere length in tumoral vs healthy adjacent tissues of each patient by using a q-RT PCR method and we investigated the relationship between telomere length and various sociodemographic and clinical parameters such as age, sex, tumor stage. In this pathological situation, we observed that, starting from 60 years of age, the telomere length increases in healthy mucosa and that in both healthy and cancer tissues, patients under 60 years have shorter telomeres, suggesting the telomere lengthening becomes more active with age. Finally, a positive correlation between normal and cancer tissues in both non-metastatic and metastatic stages, indicates telomere length in cancer tissue depends essentially on tumor stages. Our data allow us to suggest that telomere length depends on sex and age in healthy tissue while shortening and lengthening fluctuates considerably according to the tumor stage.

Clinical implications of clonal chromosomal abnormalities in Philadelphia negative cells in CML patients after treated with tyrosine kinase inhibitors Publication date: October 2019 Source: Cancer Genetics, Volume 238 Author(s): Hongyu Ni, Xinlai Sun, Yin Xu, Derek Lyle, Paris Petersen, Xianfeng Zhao, Hong Drum, Bei You, Dongfang Liu, Chen Liu, Jie-Gen Jiang Abstract Emergence of clonal chromosomal abnormalities in Philadelphia chromosome-negative (CCA/Ph-) cells in chronic myeloid leukemia (CML) patients during the treatment with tyrosine kinase inhibitors (TKIs) is an interesting phenomenon. Although previous studies revealed some potential impact of CCA/Ph- on CML patients’ outcome, clinical significance of CCA/Ph- in CML patients remains to be further elucidated. We retrospectively reviewed the patients with CML evaluated at Genoptix Medical Laboratory in Carlsbad, California from 2005 to 2015. Twenty-four CML patients with CCA/Ph- cells were identified. These include 18 patients with single chromosomal abnormality, 4 patients with double chromosomal abnormalities, and two patients with complex cytogenetic abnormalities. In addition to trisomy 8 and monosomy 7, we identified that 20q- was also a common abnormality in CCA/Ph- cells. Most of the patients with CCA/Ph- cells demonstrated no significant dysplasia or increased blasts with two exceptions: one patient with persistent 7q- exhibiting mild dysmegakaryopoiesis, suggestive of an early evolving myelodysplastic syndrome, and another patient with complex cytogenetic abnormalities who developed acute myeloid leukemia after gained MLL amplification. One patient with complex cytogenetic abnormalities showed optimal response to TKI treatment, no overt dysplasia, and no disease progression during almost 4-years of follow-up. More interestingly, FISH tests could identify more cases with double chromosomal abnormalities and these cases showed suboptimal responses to TKI treatments. Our observation indicates that 20q- was also a common abnormality in CCA/Ph- cells, further FISH tests revealed additional CCA/Ph-, and the majority of CML patients with two or more chromosomal abnormalities in Ph- cells showed inferior response to TKI treatments. The results of our study suggest that CML cases with CCA/Ph- may represent a group of patients with heterogeneous genetic alterations.

RUNX1 deletion/amplification in therapy-related acute myeloid leukemia: A case report and review of the literature Publication date: October 2019 Source: Cancer Genetics, Volume 238 Author(s): David Nguyen, Yuwen Li, Hana Safah, Theresa C. Brown Abstract Intrachromosomal amplification of chromosome 21 (iAMP21) is a rare occurrence in acute myeloid leukemia (AML). We describe here a case of AML with apparent amplification of RUNX1 by cytogenetics and FISH. A 39-year-old female in remission from stage IIIa breast cancer was diagnosed with therapy-related AML (t-AML). The patient's bone marrow was hypocellular for her age (30–40%) with 25% blasts. Cytogenetic analyses revealed a complex karyotype, characterized by rearrangements in chromosomes 1, 5, 17, 20, an additional unidentified marker chromosome, and apparent amplification of chromosome 21. Fluorescence in situ hybridization detected deletions of CKS1B, EGR1, TP53, and apparent amplification of RUNX1 (6–8 signals). Array comparative genomic hybridization (array-CGH) detected amplification of the 5’ non-coding region of RUNX1 and deletion of the 3’ coding region of RUNX1. These results show that this is not a true case of iAMP21 and suggest that RUNX1 is not the primary target of amplification.

Cytogenomic characterization of double minute heterogeneity in therapy related acute myeloid leukemia Publication date: October 2019 Source: Cancer Genetics, Volume 238 Author(s): Prasad Koduru, Weina Chen, Barbara Haley, Kevin Ho, Dwight Oliver, Kathleen Wilson Abstract Breast cancer patients treated with adjuvant chemotherapy regimens containing alkylating agents and anthracyclines are at an increased risk for secondary myeloid malignancies, either acute myeloid leukemia (AML) or myelodysplastic syndrome (MDS). Complex genomic changes (karyotypes and/or gene amplification) accompany the development of the secondary neoplasms. Here we present a unique case of a breast cancer patient who developed secondary AML within 18 months of treatment with trastuzumab, pertuzumab, docetaxel, carboplatin (TCHP) and radiation. Leukemia cells had catastrophic alterations in chromosomes 8, 11, and 17. Genetic abnormalities in the leukemia cells included amplification of MYC and KMT2A as double minutes, and deletion and mutational inactivation of TP53 Concurrent amplification of different genes at different levels and on different double minutes, we have named “double minute heterogeneity.” Clinically, this case highlights the need to identify genes amplified in secondary myeloid malignancies by cytogenomic microarray (CMA) analysis since these may have therapeutic implications.

Variants in COL6A3 gene influence susceptibility to esophageal cancer in the Chinese population Publication date: October 2019 Source: Cancer Genetics, Volume 238 Author(s): Yang Li, Yao Sun, Qinshuai Yang, Jiamin Wu, Zichao Xiong, Shanqu Li, Tianbo Jin Abstract Esophageal cancer (EC) is a frequent malignant tumor in our world, and has a highly morbidity and mortality. It was reported that genetic factors play vital roles in its pathogenesis. Here, we performed a case - control study to evaluate the COL6A3 genetic variants and EC risk in a Chinese Han cohort. All subjects were genotyped with the Agena MassARRAY platform. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated by logistic regression after adjusting age and gender. We found that rs6720283 (G > A) allele had significantly enhanced EC risk (OR = 1.32, 95% CI = 1.11 alculate p = 0.002). Stratified analysis was performed by gender, age, alcohol drinking, BMI, TNM stage and lymph node metastasis, the results showed that rs7436, rs115510139 and rs6720283 were significantly associated with the risk of EC in different groups (all p < 0.05). Besides, no statistical significant was found between the COL6A3 gene polymorphisms and clinicopathological parameters such as TNM stage and lymph node metastasis among EC patients (p > 0.05). In conclusions, our study found that COL6A3 variants were associated with risk of EC in the Chinese population.

Homogeneously staining region (hsr) on chromosome 11 is highly specific for KMT2A amplification in acute myeloid leukemia (AML) and myelodysplastic syndrome (MDS) Publication date: October 2019 Source: Cancer Genetics, Volume 238 Author(s): Ali Sakhdari, Zhenya Tang, Chi Young Ok, Carlos E. Bueso-Ramos, L. Jeffrey Medeiros, Yang O. Huh Abstract AML and MDS are most common myeloid neoplasms that affect mainly older patients. Overexpression of certain proto-oncogenes plays an indispensable role in tumorigenesis and overexpression can be a consequence of gene rearrangement, amplification and/or mutation. Rearrangement and amplification of KMT2A located at chromosome band 11q23 is a well-characterized genetic driver in a subset of AML/MDS cases and is associated with a poor prognosis. The presence of homogeneously staining regions (hsr) also has been correlated with amplification of specific proto-oncogenes. In this study, we correlated hsr(11)(q23) with KMT2A in a large cohort of AML/MDS (n = 54) patients. We identified 37 patients with hsr(11)(q23) in the setting of AML (n = 27) and MDS (n = 10). All patients showed a complex karyotype including 12 cases with monosomy 17. KMT2A FISH analysis was available for 35 patients which showed KMT2A amplification in all patients. Among control cases with hsr involving chromosomes other than 11q [non-11q hsr, n = 17], FISH analysis for KMT2A was available in 10 cases and none of these cases showed KMT2A amplification (p = 0.0001, Fisher's exact test, two-tailed). Mutational analysis was performed in 32 patients with hsr(11)(q23). The most common mutated gene was TP53 (n = 29), followed by DNMT3A (n = 4), NF1 (n = 4), and TET2 (n = 3). Thirty (83%) patients died over a median follow-up of 7.6 months (range, 0.4–33.4). In summary, hsr(11)(q23) in AML/MDS cases is associated with a complex karyotype, monosomy 17, KMT2A amplification, and TP53 mutation.

ANKRD26-RET - A novel gene fusion involving RET in papillary thyroid carcinoma Publication date: October 2019 Source: Cancer Genetics, Volume 238 Author(s): Julia Isabelle Staubitz, Thomas Johannes Musholt, Arno Schad, Erik Springer, Hauke Lang, Krishnaraj Rajalingam, Wilfried Roth, Nils Hartmann Abstract Background Rearrangements of RET are drivers of oncogenesis, traceable in different cancer types as papillary thyroid carcinoma (PTC), non-small cell lung cancer, colorectal or breast cancer. Anchored multiplex PCR based next-generation sequencing (NGS) can detect RET rearrangements involving previously unknown partner genes. Methods A sample of PTC underwent NGS, following detection of RET rearrangement by fluorescence in situ hybridization. Expression analysis of ANKRD26 and RET was performed for the tumor harboring ANKRD26-RET, for corresponding normal thyroid tissue and PTC tumors with representative genetic alterations (BRAFV600E, CCDC6-RET), complemented by a comparative search in the “UniProt” database. Results NGS analysis resulted in the discovery of the fusion ANKRD26-RET. ANKRD26 mRNA was expressed in all PTC tumors (ANKRD26-RET, BRAFV600E, CCDC6-RET) and in normal thyroid tissue, whereas RET mRNA was detected only in the tumors with RETrearrangement. On protein level, ANKRD26-RET combines the RET tyrosine kinase to ankyrin repeat and coiled-coil domains. Conclusions ANKRD26-RET is a novel rearrangement of the RET gene, associated with RET expression in thyroid tissue. The result is a fusion of the RET tyrosine kinase to prominent protein-protein interaction motifs. Further studies are required to investigate the influence of different RET rearrangements on metastasis and disease-free survival in PTC.