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Immortalization of epithelial cells in oral carcinogenesis as revealed by genome-wide array comparative genomic hybridization: A meta-analysis

Vincent-Chong VK, Salahshourifar I, Razali R, Anwar A, Zain RB

Head Neck, 2016 04;38 Suppl 1:E783-97.
PMID: 25914319 DOI: 10.1002/hed.24102

BACKGROUND: This purpose of this meta-analysis study was to identify the most frequent and potentially significant copy number alteration (CNA) in oral carcinogenesis.
METHODS: Seven oral squamous cell carcinoma (OSCC)-related publications, corresponding to 312 samples, were identified for this meta-analysis. The data were analyzed in a 4-step process that included the genome assembly coordination of multiple platforms, assignment of chromosomal position anchors, calling gains and losses, and functional annotation analysis.
RESULTS: Gains were more frequent than losses in the entire dataset. High-frequency gains were identified in chromosomes 5p, 14q, 11q, 7p, 17q, 20q, 8q, and 3q, whereas high-frequency losses were identified in chromosomes 3p, 8p, 6p, 18q, and 4q. Ingenuity pathway analysis showed that the top biological function was associated with immortalization of the epithelial cells (p = 1.93E-04).
CONCLUSION: This study has identified multiple recurrent CNAs that are involved in various biological annotations associated with oral carcinogenesis. © 2015 Wiley Periodicals, Inc. Head Neck 38: E783-E797, 2016.

Matched MeSH terms: Chromosome Aberrations
Fulltext Somatic copy-neutral loss of heterozygosity and copy number abnormalities in Malaysian sporadic colorectal carcinoma patients

Yam YY, Hoh BP, Othman NH, Hassan S, Yahya MM, Zakaria Z, et al.

Genet. Mol. Res., 2013;12(1):319-27.
PMID: 23420356 DOI: 10.4238/2013.February.7.1

Colorectal cancer is one of the most common cancers in many countries, including Malaysia. The accumulation of genomic alterations is an important feature of colorectal carcinogenesis. A better understanding of the molecular events underlying the stages of colorectal carcinogenesis might be helpful in the detection and management of the disease. We used a commercially available single-nucleotide polymorphism genotyping array to detect both copy number abnormalities (CNAs) and copy-neutral loss of heterozygosity (LOH) in sporadic colorectal carcinomas. Matched tumor and normal tissues of 13 colorectal carcinomas (Dukes' stages A-D) were analyzed using a 250K single nucleotide polymorphism array. An additional assay was performed to determine the microsatellite instability status by using the National Cancer Institute-recommended BAT-26 panel. In general, copy number gain (92.3%) was most common, followed by copy number loss (53.8%) and copy-neutral LOH (46.2%). Frequent CNAs of gains and losses were observed on chromosomes 7p, 8, 13q, 17p, 18q, and 20q, and copy-neutral LOH was observed on chromosomes 2, 6, 12, 13q, 14q, 17, 20p, 19q, and 22q. Even though genomic alterations are associated with colorectal cancer progression, our results showed that DNA CNAs and copy-neutral LOH do not reflect disease progression in at least 50% tumors. Copy-neutral LOH was observed in both early and advanced tumors, which favors the involvement of these genomic alterations in the early stages of tumor development.

Matched MeSH terms: Chromosome Aberrations*
Fulltext Genetic alterations of chromosome 8 genes in oral cancer

Yong ZW, Zaini ZM, Kallarakkal TG, Karen-Ng LP, Rahman ZA, Ismail SM, et al.

Sci Rep, 2014;4:6073.
PMID: 25123227 DOI: 10.1038/srep06073

The clinical relevance of DNA copy number alterations in chromosome 8 were investigated in oral cancers. The copy numbers of 30 selected genes in 33 OSCC patients were detected using the multiplex ligation-dependent probe amplification (MLPA) technique. Amplifications of the EIF3E gene were found in 27.3% of the patients, MYC in 18.2%, RECQL4 in 15.2% and MYBL1 in 12.1% of patients. The most frequent gene losses found were the GATA4 gene (24.2%), FGFR1 gene (24.2%), MSRA (21.2) and CSGALNACT1 (12.1%). The co-amplification of EIF3E and RECQL4 was found in 9% of patients and showed significant association with alcohol drinkers. There was a significant association between the amplification of EIF3E gene with non-betel quid chewers and the negative lymph node status. EIF3E amplifications did not show prognostic significance on survival. Our results suggest that EIF3E may have a role in the carcinogenesis of OSCC in non-betel quid chewers.

Matched MeSH terms: Chromosome Aberrations
Supernumerary chromosomes in the black rat (Rattus rattus) and their distribution in three geographic variants

Yosida TH

Cytogenet. Cell Genet., 1977;18(3):149-59.
PMID: 862437

Supernumerary chromosomes have been examined in 352 black rats, covering three geographic variants, by use of conventional and C-band staining techniques. Metacentric supernumerary chromosomes, one to three in number, were found in Malayan black rats (Rattus rattus diardii), with 2n=42, in Indian black rats (R. rattus rufescens), with 2n=38, and in Ceylonese black rats (R. rattus kandianus), with 2n=40. The supernumeraries had similar morphology and stained heavily along their entire length by C-band staining. These findings suggested that the supernumeraries had originally developed in the Asian-type black rats and then were sequentially transmitted to the Ceylonese and Oceanian-type black rats, probably in southwestern Asia. A subtelocentric supernumerary chromosome found in one Japanese black rat seemed to have developed independently from the above metacentric supernumeraries.

Matched MeSH terms: Chromosome Aberrations*
Fulltext Genotoxicity of Euphorbia hirta: an Allium cepa assay

Yuet Ping K, Darah I, Yusuf UK, Yeng C, Sasidharan S

Molecules, 2012 Jun 26;17(7):7782-91.
PMID: 22735780 DOI: 10.3390/molecules17077782

The potential genotoxic effects of methanolic extracts of Euphorbia hirta which is commonly used in traditional medicine to treat a variety of diseased conditions including asthma, coughs, diarrhea and dysentery was investigated using Allium cepa assay. The extracts of 125, 250, 500 and 1,000 µg/mL were tested on root meristems of A. cepa. Ethylmethanesulfonate was used as positive control and distilled water was used as negative control. The result showed that mitotic index decreased as the concentrations of E. hirta extract increased. A dose-dependent increase of chromosome aberrations was also observed. Abnormalities scored were stickiness, c-mitosis, bridges and vagrant chromosomes. Micronucleated cells were also observed at interphase. Result of this study confirmed that the methanol extracts of E. hirta exerted significant genotoxic and mitodepressive effects at 1,000 µg/mL.

Matched MeSH terms: Chromosome Aberrations
Loss of heterozygosity on chromosomes 10q, 9p, 17p and 13q in malays with malignant glioma

Zainuddin N, Jaafart H, Isa MN, Abdullah JM

Neurol Res, 2004 Jan;26(1):88-92.
PMID: 14977064

Recent advances in neuro-oncology have revealed different pathways of molecular oncogenesis in malignant gliomas including loss of heterozygosity on chromosomal regions harboring tumor suppressor genes. In the present study, we performed polymerase chain reaction-loss of heterozygosity (PCR-LOH) analysis using microsatellite markers to identify loss of heterozygosity on chromosomes 10q, 9p, 17p and 13q in the Malays with malignant gliomas. Of 12 cases with allelic losses, seven (58.3%) cases showed LOH on chromosome 10q, three (25.0%) cases showed LOH on chromosome 9p, four (33.3%) cases showed LOH on chromosome 17p and two (16.7%) cases showed LOH on chromosome 13q. The cases include five (41.7%) cases of glioblastoma multiforme, three (25.0%) cases of anaplastic astrocytoma, three (25.0%) cases of anaplastic oligodendroglioma and one (8.3%) case of anaplastic ependymoma. Four cases showed loss of heterozygosity on more than one locus. Our findings showed that loss of heterozygosity on specific chromosomal regions contributes to the molecular pathway of glioma progression in Malay population. In addition, these data provide useful evidence of molecular genetic alterations of malignant glioma in South East Asian patients, particularly in the East Coast of Malaysia.

Matched MeSH terms: Chromosome Aberrations*
Whole-Exome Sequencing of ETV6/RUNX1 in Four Childhood Acute Lymphoblastic Leukaemia Cases

Zakaria Z, Othman N, Ismail A, Kamaluddin NR, Esa E, Abdul Rahman EJ, et al.

Asian Pac J Cancer Prev, 2017 04 01;18(4):1169-1175.
PMID: 28548470

Background: ETV6/RUNX1 gene fusion is the most frequently seen chromosomal abnormality in childhood acute
lymphobastic leukamia (ALL). However, additional genetic changes are known to be required for the development of
this type of leukaemia. Therefore, we here aimed to assess the somatic mutational profile of four ALL cases carrying the
ETV6/RUNX1 fusion gene using whole-exome sequencing. Methods: DNA was isolated from bone marrow samples
using a QIAmp DNA Blood Mini kit and subsequently sequenced using the Illumina MiSeq system. Results: We
identified 12,960 to17,601 mutations in each sample, with a total of 16,466 somatic mutations in total. Some 15,533
variants were single nucleotide polymorphisms (SNPs), 129 were substitutions, 415 were insertions and 389 were
deletions. When taking into account the coding region and protein impact, 1,875 variants were synonymous and 1,956
were non-synonymous SNPs. Among non-synonymous SNPs, 1,862 were missense, 13 nonsense, 35 frameshifts, 11
nonstop, 3 misstart, 15 splices disrupt and 17 in-frame indels. A total of 86 variants were located in leukaemia-related
genes of which 32 variants were located in the coding regions of GLI2, SP140, GATA2, SMAD5, KMT2C, CDH17,
CDX2, FLT3, PML and MOV10L1. Conclusions: Detection and identification of secondary genetic alterations are
important in identifying new therapeutic targets and developing rationally designed treatment regimens with less
toxicity in ALL patients.

Matched MeSH terms: Chromosome Aberrations