두경부 편평상피세포암에서 종양억제유전자들의 변이

송시연(Si Youn Song),박강식(Kang Shik Park),배창훈(Chang Hoon Bai) 대한두경부종양학회 2004 대한두경부 종양학회지 Vol.20 No.2

Objectives: Head and neck squamous cell carcinoma (HNSCC) is the most common head and neck malignant tumor. The molecular genetic changes involving both oncogenes and tumor suppressor genes are known to be involved in head and neck squamous cell carcinogenesis, but the roles of the known tumor suppressor genes in carcinogenesis are not fully elucidated. The objectives of this study are to demonstrate the genetic alterations including the loss of heterozygosity (LOH) , amplification, and microsatellite instability of known tumor suppressor genes in HNSCC and to evaluate the relationship between genetic alterations of tumor suppressor genes and clinicopathologic features. Materials and Methods: Genetic alterations of 10 micro satellite markers of the 6 known tumor suppressor genes (APC, EXT1, DPC4, p16, FHIT, and PTEN) were analysed by DNA-PCR in paraffin-embedded histologically confirmed HNSCC specimens. Results: The genetic alterations of tumor suppressor genes were found frequently. Among the genetic alterations, LOH was most frequently found one. LOH was found frequently in APC (45.4%), EXT1 (36.4%), DPC4 (54.5%), and p16 (50%), but not found in FHIT. Also, the author found that abnormalities of APC gene was related to cervical lymph node metastasis and recurrence and that abnormalities of EXT1 gene were coexisted with those of APC gene or DPC4 gene. But these coexistences had no correlation with clinical features. Conclusion: These results suggested that APC, EXT1, p16, and DPC4 genes might play important roles and multiple tumor suppressor genes may participate dependently or independently in the carcinogenesis of HNSCC. These results also suggested that APC gene might relate to prognosis.

Quantification of Tumor Suppressor mRNA Expression by Poly-competitive RT-PCR Using a TS-IS that Contained Multiple Internal Competitors

Hee-Jung Jung,Ji Hyung Chae,김호근,JeonHan Park,Jong Soo Lee,Woong Hwan Choi,김철근 한국분자세포생물학회 2002 Molecules and cells Vol.13 No.3

Despite the recent introduction of real-time PCR methods and cDNA microarrays, competitive PCR techniques continue to play an important role in nucleic acid quantification because of the significantly lower cost of equipment and consumables. In this study, we developed a construct, termed tumor suppressor- internal standard (TS-IS) that produced polycompetitive RNA templates as an internal standard to quantify cellular RNA concentration of tumor suppressor genes. This construct is composed of not only sets of primers for detecting the expression of several tumor suppressor genes (such as pRB, p16INK4A, p15INK4B, p14ARF, p53, and p21WAF1), but also HPRT as an endogenous marker. Using an internal standard RNA that was synthesized from the TS-IS construct, we were able to establish optimized conditions for the quantification of tumor suppressor genes with minimal amounts (50 ng) of cellular RNA. In addition, the usefulness of this method was confirmed by analyzing the expression levels of tumor suppressor genes in fourteen hepatoma cell lines as a model. The TS-IS assay that we used was inexpensive and a widely applicable method that permitted the reliable and accurate quantification of tumor suppressor genes.

유방의 침윤성 관암에서 주요 종양 억제유전자의 이형접합 소실

박찬흔 한국유방암학회 2007 Journal of breast cancer Vol.10 No.1

Purpose: Breast cancer is one of the most frequent malignant tumors in Korea. The major tumor suppressor genes (TSGs) such as p16, Rb, E-cadherin and p53 may play important roles in cell cycle regulation, apoptosis and the regulation of the expression of other genes as well as tumor suppression. Microsatellite alteration such as loss of heterozygosity (LOH) have been reported to be a novel mechanism of carcinogenesis and a useful prognostic factor for many malignant tumors. Also, LOH is also known to be related with allelic loss of various TSGs. This study evaluated LOH of 4 TSGs in invasive ductal carcinomas (IDCs) and we correlated these results with the clinicopathological factors. Methods: LOH analysis was carried out using a polymerase chain reaction with 12 polymorphic microsatellite markers of 4 TSGs in 50 surgically resected tumors and their non-tumorous counterparts. Results: There was no detectable LOH in the normal tissue. LOH was detected in 86% of the 50 cases of IDCs. LOH was detected on al chromosomes and this showed a statistical difference between benign tumor and malignant tumor. LOH of p16, Rb, E-cadherin and p53 TSGs was detected in 36%, 26%, 54% and 60% of the tumors, respectively. LOH of the p16 and Rb genes was inversely correlated with tumor grade 1. The low rate of detecting LOH on the E-cadherin gene was noted in T1 tumor and stage I disease. LOH of the p53 gene correlated well with the tumor size and stage. The LOH-High results correlate well with the tumor size and stage and the LOH-High results are similar to those of the p53 gene LOH. Conclusion: These results suggest that LOH of the 4 major TSGs may contribute to the development and invasion of IDCs. Also, the combined use of various LOH markers may help in deciding the prognosis of IDCs.

Diffuse Large B Cell Lymphoma Shows Distinct MethylationProfiles of the Tumor Suppressor Genes among theNon-Hodgkin’s Lymphomas

윤선옥,김영아,전윤경,김지은,강경훈,김철우 대한병리학회 2008 Journal of Pathology and Translational Medicine Vol.42 No.1

Aberrant methylation of CpG islands in promoter regions is one of the major mechanisms for silencing of tumor suppressor genes in various types of human cancers including non-Hodgkin’s lymphomas (NHL). In this study, we investigated the aberrant promoter methylation status of known or suspected tumor suppressor genes in NHLs and compared the methylation profiles between B-cell and T/NK-cell NHLs. Methods : 54 cases of B-cell NHLs and 16 cases of T/NK-cell NHLs were examined for the methylation status of eight genes using methylation specific PCR. Results : CpG islands methylation was variously found in eight genes as follows; DAPK (71%), MT1G (70%), p16 (53%), CDH1 (53%), THBS1 (56%), MGMT (27.1%), COX2 (13%), and RUNX3 (11.4%). In six cases (8 %), methylation was not observed in any of these genes. Overall methylation index of B-cell NHLs (0.48) was significantly higher than that of T/NK-cell NHLs (0.32). Of eight genes tested, THBS1 and CDH1 methylations were much more prominent in diffuse large B-cell lymphomas than in T/NK-cell NHLs or other B-cell NHLs. Conclusion : This study suggests that aberrant CpG island methylation is a frequent event in NHLs, and diffuse large B-cell lymphomas show overlapping but distinct methylation profiles. Aberrant methylation of CpG islands in promoter regions is one of the major mechanisms for silencing of tumor suppressor genes in various types of human cancers including non-Hodgkin’s lymphomas (NHL). In this study, we investigated the aberrant promoter methylation status of known or suspected tumor suppressor genes in NHLs and compared the methylation profiles between B-cell and T/NK-cell NHLs. Methods : 54 cases of B-cell NHLs and 16 cases of T/NK-cell NHLs were examined for the methylation status of eight genes using methylation specific PCR. Results : CpG islands methylation was variously found in eight genes as follows; DAPK (71%), MT1G (70%), p16 (53%), CDH1 (53%), THBS1 (56%), MGMT (27.1%), COX2 (13%), and RUNX3 (11.4%). In six cases (8 %), methylation was not observed in any of these genes. Overall methylation index of B-cell NHLs (0.48) was significantly higher than that of T/NK-cell NHLs (0.32). Of eight genes tested, THBS1 and CDH1 methylations were much more prominent in diffuse large B-cell lymphomas than in T/NK-cell NHLs or other B-cell NHLs. Conclusion : This study suggests that aberrant CpG island methylation is a frequent event in NHLs, and diffuse large B-cell lymphomas show overlapping but distinct methylation profiles.

Loss of Heterozygosities in Five Tumor Suppressor Genes (FHIT Gene, p16, pRb, E-Cadherin and p53) in Thyroid Tumors

김진환,최규영,이동진,노영수,조성진 대한이비인후과학회 2014 Clinical and Experimental Otorhinolaryngology Vol.7 No.1

Objectives. To evaluate the loss of heterozygosities (LOH) of chromosomes 3p14 (FHIT gene), 9p21 (p16), 13q21 (pRb), 6q22 (E-cadherin) and 17p13 (p53) in various thyroid tumors. Methods. Eighty thyroid tumor cases (20 follicular adenomas, 10 follicular carcinomas, and 50 papillary carcinomas) have been analyzed for the presence of LOH in chromosomes 3p14, 9p21, 13q21, 6q22, and 17p13 allelic loss, using mic- rosatellite markers and DNA obtained from formalin-fixed paraffin-embedded archival tissues. Results. LOH on 3p14 was found in 10.5%, 33.3%, and 30.4% of follicular adenomas, follicular carcinomas, and papillary carcinomas, respectively. LOH on 9p21 was detected in 6%, 44.4%, and 47.8%, respectively. LOH on pRb gene was found in 5.3%, 20.0%, and 35.4%, respectively. LOH on E-cadherin gene was found in 5.3%, 22.2%, and 43.8%, respectively. LOH on 17p13 was detected in 0%, 40%, and 45.8%, respectively. LOH in FHIT gene, p16, pRb, E- cadherin, and p53 genes were more frequently identified in follicular carcinoma and papillary carcinoma than in fol- licular adenoma. Conclusion. LOH results of the five tumor suppressor genes (FHIT gene, p16, pRb, E-cadherin, and p53) showed statistical differences between benign tumor and malignant tumor. Among papillary carcinoma, LOH in p16, E-cadherin and p53 genes well correlated with poorly differentiated grade, and LOH of E-cadherin was associated with lymph node metastasis.

Integrative epigenomic and genomic analysis of malignant pheochromocytoma

Sandgren, Johanna,Andersson, Robin,Rada-Iglesias, Alvaro,Enroth, Stefan,Akerstrom, Goran,Dumanski, Jan P.,Komorowski, Jan,Westin, Gunnar,Wadelius, Claes Korean Society for Biochemistry and Molecular Bion 2010 Experimental and molecular medicine Vol.42 No.7

Epigenomic and genomic changes affect gene expression and contribute to tumor development. The histone modifications trimethylated histone H3 lysine 4 (H3K4me3) and lysine 27 (H3K27me3) are epigenetic regulators associated to active and silenced genes, respectively and alterations of these modifications have been observed in cancer. Furthermore, genomic aberrations such as DNA copy number changes are common events in tumors. Pheochromocytoma is a rare endocrine tumor of the adrenal gland that mostly occurs sporadic with unknown epigenetic/genetic cause. The majority of cases are benign. Here we aimed to combine the genome-wide profiling of H3K4me3 and H3K27me3, obtained by the ChIP-chip methodology, and DNA copy number data with global gene expression examination in a malignant pheochromocytoma sample. The integrated analysis of the tumor expression levels, in relation to normal adrenal medulla, indicated that either histone modifications or chromosomal alterations, or both, have great impact on the expression of a substantial fraction of the genes in the investigated sample. Candidate tumor suppressor genes identified with decreased expression, a H3K27me3 mark and/or in regions of deletion were for instance TGIF1, DSC3, TNFRSF10B, RASSF2, HOXA9, PTPRE and CDH11. More genes were found with increased expression, a H3K4me3 mark, and/or in regions of gain. Potential oncogenes detected among those were GNAS, INSM1, DOK5, ETV1, RET, NTRK1, IGF2, and the H3K27 trimethylase gene EZH2. Our approach to associate histone methylations and DNA copy number changes to gene expression revealed apparent impact on global gene transcription, and enabled the identification of candidate tumor genes for further exploration.

Integrative epigenomic and genomic analysis of malignant pheochromocytoma

Johanna Sandgren,Robin Andersson,Alvaro Rada-Iglesias,Stefan Enroth,Jan Komorowski,Claes Wadelius,Göran Åkerström,Jan P. Dumanski,Gunnar Westin 생화학분자생물학회 2010 Experimental and molecular medicine Vol.42 No.7

Epigenomic and genomic changes affect gene expression and contribute to tumor development. The histone modifications trimethylated histone H3 lysine 4 (H3K4me3) and lysine 27 (H3K27me3) are epigenetic regulators associated to active and silenced genes, respectively and alterations of these modifications have been observed in cancer. Furthermore, genomic aberrations such as DNA copy number changes are common events in tumors. Pheochromocytoma is a rare endocrine tumor of the adrenal gland that mostly occurs sporadic with unknown epigenetic/genetic cause. The majority of cases are benign. Here we aimed to combine the genome-wide profiling of H3K4me3 and H3K27me3, obtained by the ChIP-chip methodology,and DNA copy number data with global gene expression examination in a malignant pheochromocytoma sample. The integrated analysis of the tumor expression levels, in relation to normal adrenal medulla,indicated that either histone modifications or chromosomal alterations, or both, have great impact on the expression of a substantial fraction of the genes in the investigated sample. Candidate tumor suppressor genes identified with decreased expression, a H3K27me3 mark and/or in regions of deletion were for instance TGIF1, DSC3, TNFRSF10B, RASSF2, HOXA9,PTPRE and CDH11. More genes were found with increased expression, a H3K4me3 mark, and/or in regions of gain. Potential oncogenes detected among those were GNAS, INSM1, DOK5, ETV1, RET, NTRK1,IGF2, and the H3K27 trimethylase gene EZH2. Our approach to associate histone methylations and DNA copy number changes to gene expression revealed apparent impact on global gene transcription, and enabled the identification of candidate tumor genes for further exploration.

Aberrant methylation of the 16q23.1 tumor suppressor gene ADAMTS18 promotes tumorigenesis and progression of clear cell renal cell carcinoma

Ben Xu,Yi‑ji Peng,Bing‑lei Ma,Si‑da Cheng 한국유전학회 2021 Genes & Genomics Vol.43 No.2

Background The 16q23.1 tumor suppressor gene (TSG) of ADAMTS18 has been identifed to be aberrant methylated in clear cell renal cell carcinoma (ccRCC), and there still exists an unclear situation between its methylation and the progression of ccRCC. Objective To analyze the biological function and mechanism of ADAMTS18 gene in the tumorigenesis and progression of ccRCC. Methods We examined ADAMTS18 gene methylation using methylation- specifc polymerase chain reaction (MSP) in 92 ccRCC primary tumors from September 2017 to May 2018. Using reverse transcriptase PCR (RT-PCR) and immunohistochemical (IHC) assay, the relative expression level of ADAMTS18 was measured in the representative tumor samples with their adjacent normal tissues. Meanwhile, colony formation, cell viability, wound healing, transwell chamber, fow cytometry, and PI staining were performed to confrm the tumor-suppressive function and mechanism of ADAMTS18 gene. Results Aberrant methylation was further detected in 47 of the 92 (51.1%) primary tumors and in 8 of the 92 (8.7%) adjacent normal tissues (p<0.05). Due to the phenomenon of aberrant methylation, ectopic low-level expression of ADAMTS18 gene could result in the promotion of tumorigenesis and progression in ccRCC. Conclusion The aberrantly methylated ADAMTS18 gene may be involved in the tumorigenesis and progression of ccRCC.

위암종에서 대장 선종성 용종증 유전자의 돌연변이

박원상,유문간,이석철,정연준,김금룡,김주성 대한병리학회 1993 Journal of Pathology and Translational Medicine Vol.27 No.1

Gene Mutations in Animal Models: Do Tumor Suppressor Genes, brca1 and brca2, Play a Role in Ovarian Carcinogenesis?

Bo-Rim Yi,Kyung-A Hwang,Kyung-Chul Choi 한국실험동물학회 2010 Laboratory Animal Research Vol.26 No.4

Ovarian cancer is the most lethal cause of death from gynecological malignancies in the Western world. Over 90% of human ovarian cancers arise in the ovarian surface epithelium (OSE). The OSE surrounding the ovary is simple mesothelium and squamous to flat-cubobidal mesothelial cells. This cell type of ovary has both epithelial and mesenchymal potential. Also OSE cells are regulated by many factors such as cytokines, growth factors, and multiple hormones. Nevertheless OSE function is poorly understood. In particular, ovarian cancers are closely related with hereditary predisposition. Hereditary ovarian tumors are commonly associated with mutations in tumor suppressor genes such as brca1 and brca2 genes. These genes play a role in maintenance of genome integrity, DNA repair, cell cycle control and apoptosis. Mutations in brca1 and/or brca2 may lead to carcinogenesis through distinct molecular pathways like estrogen-mediated proliferation, the presence of a p53 mutation, and the modulation of the activity of NF-kB. Especially the dysfunction of brca1 triggers the inactivation of p53 and a higher proportion of a p53 mutation is commonly linked to brca-linked ovarian tumorigenesis. The dysfunction of brca1 and/or brca2 can arise from multiple mechanisms in the regulation of both JNK and ERK1/2 signaling. For more effective diagnosis and therapy of ovarian cancer, the role of brca1 and/or brca2 in ovarian cancer has to be distinctively elucidated by the animal models in which the gene functions are deleted in mouse OSE cells and by the mechanisms by which these genes affect ovarian carcinogenesis.