• Journal of Yeungnam Medical Science
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• v.22 no.2
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• pp.166-182
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• 2005

Background: Cyclin-dependent kinase (CDK) inhibitors are family of molecules that regulate the cell cycle. The CDKN2, a CDK4 inhibitor, also called p16, has been implicated in human tumorigenesis. The CDKN2 inhibits the cyclin/CDK complexes which regulate the transition from G1 to S phase of cell cycle. There is a previous report that homozygous deletion of CDKN2 region on chromosome 9p21 was detected frequently in astrocytoma, glioma and osteosarcoma, less frequently in lung cancer, leukemia and ovarian cancer, but not detected in colon cancer and neuroblastoma. However, little is known about the relationship between CDKN2 and laryngeal cancer. Therefore this study was initiated to investigate the role of CDKN2 in human laryngeal squamous cell carcinoma development.1) Materials and methods: We used 5 human laryngeal carcinoma cell lines whether they have deletions or losses of CDKN2 gene expression by DNA-PCR or RT-PCR, respectively. We examined 8 fresh frozen human laryngeal cancer tissues to detect the loss of heterozygosity (LOH) of CDKN2. PCR was performed by using microsatellite markers of short arm of human chromosome 9 (D9S126, D9S144, D9S156, D9S161, D9S162, D9S166, D9S171, D9S200 and D9SIFNA). For informative cases, allelic loss was scored if the signal of one allele was significantly decreased in tumor DNA when compared to the same allele in normal DNA. Results: The CDKN2 DNA deletion was observed in 3 cell lines. The CDKN2 mRNA expression was observed in only one cell line, which was very weak. LOH was detected in 7 cases (87.5%). Conclusion: These results suggest that CDKN2 plays a role in the carcinogenesis of human laryngeal squamous cell carcinoma.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.6
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• pp.2629-2633
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• 2012

Background: Raw betel nut (RBN) chewing is an important contributing factor for esophageal squamous cell carcinoma (ESCC), although associated genomic changes remain unclear. One difficulty in assessing the effects of exclusively RBN induced genetic alterations has been that earlier studies were performed with samples of patients commonly using tobacco and alcohol, in addition to betel-quid. Both CDKN2A (at 9p21) and Rb1 gene (at 13q14.2) are regarded as tumor suppressors involved in the development of ESCC. Therefore, the present study aimed to verify the RBN's ability to induce ESCC and assess the involvement of CDKN2A and Rb1 genes. Methods: A panel of dinucelotide polymorphic markers were chosen for loss of heterozygosity studies in 93 samples of which 34 were collected from patients with only RBN-chewing habit. Promoter hypermethylation was also investigated. Results: Loss in microsatellite markers D9S1748 and D9S1749, located close to exon $1{\beta}$ of CDKN2A/ARF gene at 9p21, was noted in 40% ESCC samples with the habit of RBN-chewing alone. Involvement of a novel site in the 9p23 region was also observed. Promoter hypermethylation of CDKN2A gene in the samples with the habit of only RBN-chewing alone was significantly higher (p=0.01) than Rb1 gene, also from the samples having the habit of use both RBN and tobacco (p=0.047). Conclusions: The data indicate that the disruption of 9p21 where CDKN2A gene resides, is the most frequent critical genetic event in RBN-associated carcinogenesis. The involvement of 9p23 as well as 13q14.2 could be required in later stages in RBN-mediated carcinogenesis.

• Laboraroty Animal Research
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• v.34 no.4
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• pp.264-269
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• 2018

Cell cycle dysfunction can cause severe diseases, including neurodegenerative disease and cancer. Mutations in cyclin-dependent kinase inhibitors controlling the G1 phase of the cell cycle are prevalent in various cancers. Mice lacking the tumor suppressors $p16^{Ink4a}$ (Cdkn2a, cyclin-dependent kinase inhibitor 2a), $p19^{Arf}$ (an alternative reading frame product of Cdkn2a,), and $p27^{Kip1}$ (Cdkn1b, cyclin-dependent kinase inhibitor 1b) result in malignant progression of epithelial cancers, sarcomas, and melanomas, respectively. Here, we generated knockout mouse models for each of these three cyclin-dependent kinase inhibitors using engineered nucleases. The $p16^{Ink4a}$ and $p19^{Arf}$ knockout mice were generated via transcription activator-like effector nucleases (TALENs), and $p27^{Kip1}$ knockout mice via clustered regularly interspaced short palindromic repeats/CRISPR-associated nuclease 9 (CRISPR/Cas9). These gene editing technologies were targeted to the first exon of each gene, to induce frameshifts producing premature termination codons. Unlike preexisting embryonic stem cell-based knockout mice, our mouse models are free from selectable markers or other external gene insertions, permitting more precise study of cell cycle-related diseases without confounding influences of foreign DNA.

• Genomics & Informatics
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• v.18 no.3
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• pp.27.1-27.12
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• 2020

The prevalence of early-onset type 2 diabetes (EOT2D) is increasing in Asian countries. Genome-wide association studies performed in European and various other populations have identified associations of numerous variants with type 2 diabetes in adults. However, the genetic component of EOT2D which is still unexplored could have similarities with late-onset type 2 diabetes. Here in the present study we aim to identify the association of variants with EOT2D in South Indian population. Twenty-five variants from 18 gene loci were genotyped in 1,188 EOT2D and 1,183 normal glucose tolerant subjects using the MassARRAY technology. We confirm the association of the HHEX variant rs1111875 with EOT2D in this South Indian population and also the association of CDKN2A/2B (rs7020996) and TCF7L2 (rs4506565) with EOT2D. Logistic regression analyses of the TCF7L2 variant rs4506565(A/T), showed that the heterozygous and homozygous carriers for allele 'T' have odds ratios of 1.47 (95% confidence interval [CI], 1.17 to 1.83; p = 0.001) and 1.65 (95% CI, 1.18 to 2.28; p = 0.006) respectively, relative to AA homozygote. For the HHEX variant rs1111875 (T/C), heterozygous and homozygous carriers for allele 'C' have odds ratios of 1.13 (95% CI, 0.91 to 1.42; p = 0.27) and 1.58 (95% CI, 1.17 to 2.12; p = 0.003) respectively, relative to the TT homozygote. For CDKN2A/2B variant rs7020996, the heterozygous and homozygous carriers of allele 'C' were protective with odds ratios of 0.65 (95% CI, 0.51 to 0.83; p = 0.0004) and 0.62 (95% CI, 0.27 to 1.39; p = 0.24) respectively, relative to TT homozygote. This is the first study to report on the association of HHEX variant rs1111875 with EOT2D in this population.

• Molecular & Cellular Toxicology
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• v.2 no.3
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• pp.159-165
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• 2006

To determine the anticancer effect of D-amygdalin (D-mandelinitrole-${\beta}$-D-gentiobioside) in human chronic myeloid leukemia cells K562, we profiled the gene expression between amygdalin treatment and control groups. Through 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assay, the cytotoxicity of D-amygdalin was $57.79{\pm}1.83%$ at the concentration of 5 mg/mL for 24 h. We performed cDNA microarray analysis and compared the gene expression profiles between D-amygdalin (5 mg/mL, 24 h) treatment and control groups. Among the genes changed by D-amygdalin, we paid attention to cell cycle-related genes, and particularly cell cycle regulator genes; because arrest of cell cycle processing was ideal tactic in remedy for cancer. In our data, expressions of cyclin-dependent kinase inhibitor 1B (p27, Kip1) (CDKN1B), ataxia telangiectasia mutated (includes complementation groups A, C, and D) (ATM), cyclin-dependent kinase inhibitor 1C (p57, Kip2) (CDKN1C), and CHK1 checkpoint homolog (CHEK1, formally known as CHK1) were increased, while expressions of cyclin-dependent kinase 2 (CDK2), cell division cycle 25A (CDC25A), and cyclin E1 (CCNE1) were decreased. The pattern of these gene expressions were confirmed through RT-PCR. Our results showed that D-amygdalin might control cell cycle regulator genes and arrest S phase of cell cycle in K562 cells as the useful anticancer drug.

• Tuberculosis and Respiratory Diseases
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• v.64 no.4
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• pp.285-292
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• 2008

Background: A diagnosis of malignant pleural effusion is clinically important, as the prognosis of lung cancer patients with malignant pleural effusion is poor. The diagnosis will be difficult if a cytological test is negative. This study was performed to investigate whether the detection of hypermethylation of the p16 (CDKN2A) and retinoic acid receptor b2 (RARB2) genes in pleural fluid is useful for a diagnosis of malignant pleural effusion. Methods: Pleural effusion was collected from 43 patients and was investigated for the aberrant promoter methylation of the RARB2 and CDKN2A genes by use of methylation-specific PCR. Results were compared with findings from a pleural biopsy and from pleural fluid cytology. Results: Of 43 cases, 17 cases of pleural effusion were due to benign diseases, and 26 cases were from lung cancer patients with malignant pleural effusion. Hypermethylation of the RARB2 and CDKN2A genes was not detected in the case of benign diseases, independent of whether or not the patients had ever smoked. In 26 cases of malignant pleural effusion, hypermethylation of RARB2, CDKN2A or either of these genes was detected in 14, 5 and 15 cases, respectively. The sensitivities of a pleural biopsy, pleural fluid cytology, hypermethylation of RARB2, hypermethylation of CDKN2A, or hypermethylation of either of the genes were 73.1%, 53.8%, 53.8%, 19.2%, and 57.7%, respectively; negative predictive values were 70.8%, 58.6%, 58.6%, 44.7%, and 60.7%, respectively. If both genes are considered together, the sensitivity and negative predictive value was lower than that for a pleural biopsy, but higher than that for pleural fluid cytology. The sensitivity of hypermethylation of the RARB2 gene for malignant pleural effusion was lower in small cell lung cancers than in non-small cell lung cancers. Conclusion: These results demonstrate that detection of hypermethylation of the RARB2 and CDKN2A genes showed a high specificity, and sensitivity was higher than for pleural fluid cytology. With a better understanding of the pathogenesis of lung cancer according to histological types at the molecular level, and if appropriate genes are selected for hypermethylation testing, more precise results may be obtained.

• Journal of Genetic Medicine
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• v.18 no.1
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• pp.24-30
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• 2021

Epigenetics deals with modifications in gene expression, without altering the underlying DNA sequence. Genomic imprinting is a complex epigenetic phenomenon that refers to parent-of-origin-specific gene expression. Beckwith-Wiedemann syndrome (BWS) and Silver-Russell syndrome (SRS) are congenital imprinting disorders with mirror opposite alterations at the genomic loci in 11p15.5 and opposite phenotypes. BWS and SRS are important imprinting disorders with the increase of knowledge of genetic and epigenetic mechanisms. Altered expression of the imprinted genes in 11p15.5, especially IGF2 and CDKN1C, affects fetal and postnatal growth. A wide range of imprinting defects at multiple loci, instead of a restricted locus, has been shown in some patients with either BWS or SRS. The development of new high-throughput assays will make it possible to allow accurate diagnosis, personalized therapy, and informative genetic counseling.

• The Journal of Korean Medicine
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• v.20 no.2
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• pp.88-97
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• 1999

To characterize the effects of Gilgyung-Tang(GGT) on cellular proliferation and viability of normal lung fibroblast cells, we examined the cell cycle progression and cell cycle-related gene expression in T3891 using a flow cytometry and a quantitative RT-PCR analysis. 1. The significant surpression effect of cellular proliferations of GGT was observed in proportion to a certain concentration and time. 2. GGT was identified to induce apoptotic death of damaged cells by treatment with a DNA-damage agent and etoposide, while it stimulated the recovery of cellular viability of normal cells. 3 The significant reductions of mRNA expression of PCAN, c-Fos treated by GGT were observed. 4. The significant inductions of mRNA expression of p53, CDKN1. Gadd45 treated by GGT were observed. 5. The apoptosis caused by the reduction of Bcl-2 genes was significant and the Bax genes were increased. but the amount of Fas genes were not changed. These results strongly suggest that GGT triggers arrest of the cell cycle at G1 phase, and thus causes an inhibition of cellular proliferation of human normal lung cells through the transcriptional up-regulation of cell cycle inhibitory genes and down-regulation of induction of cell cycle stimulating genes respectably.

• Genomics & Informatics
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• v.19 no.4
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• pp.42.1-42.17
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• 2021

Salivary gland carcinoma (SGC) is rare cancer, constituting 6% of neoplasms in the head and neck area. The most responsible genes and pathways involved in the pathology of this disorder have not been fully understood. We aimed to identify differentially expressed genes (DEGs), the most critical hub genes, transcription factors, signaling pathways, and biological processes (BPs) associated with the pathogenesis of primary SGC. The mRNA dataset GSE153283 in the Gene Expression Omnibus database was re-analyzed for determining DEGs in cancer tissue of patients with primary SGC compared to the adjacent normal tissue (adjusted p-value < 0.001; |Log2 fold change| > 1). A protein interaction map (PIM) was built, and the main modules within the network were identified and focused on the different pathways and BP analyses. The hub genes of PIM were discovered, and their associated gene regulatory network was built to determine the master regulators involved in the pathogenesis of primary SGC. A total of 137 genes were found to be differentially expressed in primary SGC. The most significant pathways and BPs that were deregulated in the primary disease condition were associated with the cell cycle and fibroblast proliferation procedures. TP53, EGF, FN1, NOTCH1, EZH2, COL1A1, SPP1, CDKN2A, WNT5A, PDGFRB, CCNB1, and H2AFX were demonstrated to be the most critical genes linked with the primary SGC. SPIB, FOXM1, and POLR2A significantly regulate all the hub genes. This study illustrated several hub genes and their master regulators that might be appropriate targets for the therapeutic aims of primary SGC.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.36 no.6
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• pp.453-459
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• 2010

Introduction: Ameloblastic carcinoma is a rare malignant lesion, and may arise from either carcinoma ex-ameloblastoma or de novo carcinoma. Aberrant promoter hypermethylation of the tumor-associated genes leading to their inactivation is a common event in many cancer types. The p16/CDKN2/INK4A gene and p16 5 protein are involved directly in regulating the cell cycles. Cadherins are cell adhesion molecules that modulate the epithelial phenotype and regulate tumor invasion. The aim of this study was to evaluate the roles of p16 and E-cadherin methylation and loss of p16 and E-cadherin expression in the malignant transformation of an ameloblastoma. Materials and Methods: Eight cases of ameloblastoma, including 4 benign ameloblastomas without recurrence, 2 benign ameloblastomas with recurrence and 2 carcinoma ex-ameloblastomas, were examined. The promoter hypermethylation profile of the p16 and E-cadherin genes was studied using methylation-specific polymerase chain reaction (MSP) and immunohistochemical staining for p16 and E-cadherin expression. Results: 1) Aberrant CpG island methylation of the p16 gene was detected in 3 of the 4 benign ameloblastomas without recurrence and 1 of the 2 benign ameloblastomas with recurrence. 2) Aberrant CpG island methylation of the E-cadherin gene was found in 1 of the 4 benign ameloblastomas without recurrence. 3) A loss of p16 expression was noted in 1 of 4 benign ameloblastomas without recurrence and 1 of 2 carcinoma ex-ameloblastomas. 4) A loss of E-cadherin expression was noted in 2 of the 4 benign ameloblastomas without recurrence, 1 of the 2 benign ameloblastomas with recurrence and 2 of the 2 carcinoma ex-ameloblastomas. 5) A loss of p16 expression was observed in 1 of the 4 cases showing aberrant methylation of the p16 gene. 6) A loss of E-cadherin expression was observed in 3 benign ameloblastoma case showing aberrant methylation of the E-cadherin gene. Conclusion: These results suggest that loss of E-cadherin expression related to the other genetic pathway (not methylation) might be an adjuvant indicator predicting the malignant transformation of an ameloblastoma. However, the number of samples in this study was too small and the relationship between the treatment methods and clinical course were not defined. Therefore, further study will be needed.