Mutation of K-ras Oncogene in Thyroid Tumor Tissue

Lee, Jai Hak,Lee, Jong Seo,Kim, Seung Nam,Chang, Suk Kyun,Yoo, Seung Jin,Song, Young Tack,Cho, Won Il,Choo, Sang Yong CATHOLIC MEDICAL CENTER 1993 Bulletin of the Clinical Research Institute Vol.21 No.1

Point mutation of oncogene, one of the genetic alteration in cancer development, has been found in many malignant tumor tissues, Among those malignant tumors, the incidence of point mutation of K-ras oncogene was reported over 90% in pancreatic cancers, 40-50% in colotectal cancer, 25-30% in lung cancers and less than 10% in urogenital, breast or cervical cancers. Several investigators have reported the incidence of point mutation of ras oncogene was 30-50% in benign thyroid tumors and 50-80% in malignant thyroid tumors with some difference by tumor cell differentiation. Also some reports suggested ras mutation may constitute early steps in thyroid tumorigenesis. But there if few report about relation between point mutation and characteristics of mutation. In order to find out the incidence of k-ras oncogene point mutation and relation with characteristics of mutation in thyroid tumors, authors isolated DNA from each 10 normal tissue and benign and malignant tumor tissues. And then, point mutations of K-ras oncogene (four characteristics of codon 12 and one characteristic of codon 13) were detected by paired PCR with mutation-specific primer and agarose gel electrophoresis methods. The resets are as follows; 1. Any mutation was not detected in normal thyroid tissues. While point mutations were detected 7/10 cases (70%) of benign thyroid tumor tissues and in 9/10 cases (90%) of malignant tumor tissues. 2. The incidence of GGT-AGT mutation was highest in benign thyroid tumors (60%) and lowest in malignant thyroid tumors (30%). The incidences of GGT-GAT, TGT-GTT and GGC-GAC mutations were high in malignant tumors (60%). 3. There were 8/9 cases (89%) in malignant tumors and 5/7 cases (71%) in benign tumors of positive mutations over two Hinds of mutation. And also 5/9 cases (56%) of malignant tumors and 4/7 case (51%) of benign tumors expressed positive mutations over 3 kinds. Moreover two cases of each benign and malignant turners expressed all of five mutations. With above result, authors proposed that high incidence of point mutation of k-ras oncogene was detected in benign (70%) and malignant (90%) thyroid turners, and especially high incidence of GGT-AGT mutation (60%,) in benign tumors while high incidence of GGT-GAT, TGT, GTT and GGC-GAC mutations(60%) in malignant turners were noted. Also authors suggested that the point mutation may constitute early steps of thyroid tumorigenesis.

Types of 23S Ribosomal RNA Point Mutations and Therapeutic Outcomes for Helicobacter pylori

( Sang Yoon Kim ),( Jae Myung Park ),( Chul-hyun Lim ),( Hye Ah Lee ),( Ga-yeong Shin ),( Younghee Choe ),( Yu Kyung Cho ),( Myung-gyu Choi ) 대한소화기기능성질환·운동학회(구 대한소화관운동학회) 2021 Gut and Liver Vol.15 No.4

Background/Aims: Point mutations in the 23S ribosomal RNA gene have been associated with Helicobacter pylori clarithromycin resistance. This study aimed to detect the prevalence of these point mutations and to investigate the role of different point mutations in the success of eradication therapy. Methods: We retrospectively investigated a total of 464 consecutive patients who underwent an endoscopic examination and dual-priming oligonucleotide-based multiplex polymerase chain reaction for H. pylori between June 2014 and October 2019. For 289 patients with negative point mutations, standard triple therapy was used in 287 patients, and the bismuth-quadruple regimen was used in two patients. For 175 patients with positive point mutations (A2142G, A2143G, and both mutations), standard triple and bismuth-quadruple therapies were used in 37 patients and 138 patients, respectively. Results: The eradication rates of standard triple and bismuth-quadruple therapies showed no significant difference in mutation-negative patients or those with the A2142G point mutation. However, the eradication rate with bismuth-quadruple therapy was significantly higher than that with standard triple therapy in the group with the A2143G mutation or with the double mutation. The eradication rates for standard triple and bismuth-quadruple therapies, respectively, were 25.8% and 92.1% in the per-protocol group (p<0.001) and 24.2% and 85.2% in the intention-totreat analysis (p<0.001). Conclusions: The A2143G point mutation is the most prevalent cause of clarithromycin resistance. Bismuth-quadruple therapy is superior to standard triple therapy in patients with the A2143G or double point mutation. (Gut Liver 2021;15:528-536)

한국인 비증후군성 감각신경성 난청 환자에서 미토콘드리아 유전자 점 돌연변이의 빈도

정한신,임문정,장선오,김종선,오승하 대한이비인후과학회 2004 대한이비인후과학회지 두경부외과학 Vol.47 No.3

Background and Objectives:Mitochondrial point mutations have been shown to be responsible for syndromic and non-syndromic hearing impairment. Among these mitochondrial point mutations, 1555 A→G, 3243 A→G, and 7445 A→G mutations are detected more frequently in sensorineural hearing loss (SNHL)of these thre mitochondrial mutations among the non-syndromic SNHL population in Korea. Subjects and Method:To determine the frequency of thre mitochondrial point mutation 1555 A→G, 3243 A→G, and 7445 A→G, we examined 129 unrelated SNHL outpatients using restriction fragment length polymorphism. And to confirm these point mutations, we analyzed mitochondrial DNA with point mutations by direct sequence analysis. Results:The frequency of mitochondrial gene mutation in the unrelated sensorineural hearing impaired patients in the Korean population was 1555 A→G:2.3% (3/129), 3243 A→G:0.7% (1/129), 7445 A→G:0% (0/129). Conclusion:These results regarding Koreans are similar to those of Japanese. Each member in a family with 1555 A→G mitochondrial point mutation had variable hearing levels (different phenotype) in spite of the same mitochondrial point mutation. The pathogenesis of these mitochondrial point mutations in hearing should be further of these point mutations.

제2A형 다발성 내분비 선종에 대한 RET 유전자의 점돌연변이 분석

김성원,이강대,김주연,문효성,김영록,박요한,이길수 대한이비인후과학회 2007 대한이비인후과학회지 두경부외과학 Vol.50 No.6

Background and Objectives:Multiple Endocrine Neoplasia type 2A (MEN 2A) is a syndrome that encompases medulary thyroid carcinoma, pheochromocytoma, and hyperparathyroidism. Since MEN 2A is inherited as autosomal dominant, early de-tection and treatment is crucial. A genetic analysis of RET proto-oncogene of the family members of an index patient diagnosed as MEN 2A is reported. Subjects and Method:A patient diagnosed as MEN 2A and his 13 family members acros two gener-ood leukocyte of family members and PCR amplification of exons 10, 11, 13, 14, 15, and 16 was performed, folowed by investigation of point mutation on the RET proto-oncogene using a DNA sequence analyzer. Cervical ultrasonography was caried out in the 3 nephews who were revealed to have RET proto-oncogene point mutation. Results:Point mutations of TGC (cys) to TG (Trp) at codon 634 of exon 11 at RET proto-oncogene was detected by using automatic DNA sequence analyzing method in the index patient. The same point mutation was point mutations of RET proto-oncogene. Conclusion:With the genetic analysis of RET proto-oncogene, limitations of the con-ventional calcitonin stimulation test may be overcome, and a more complete approach can be achieved through early diagnosis by carrying out this screening test for point mutations in family members of the patient with MEN 2A. (Korean J Otolaryngol 2007 ;50 :529-36)

Rapid Detection of H-RAS Point Mutation Using Two-Step Polymerase Chain Reaction-Restriction Fragment Length Polymorphism

Park, Young-Suk,Lee, Kyung-Ok,Chai, Young-Gyu Korean Society for Biochemistry and Molecular Biol 1996 Journal of biochemistry and molecular biology Vol.29 No.5

Mutations in codon 12, 13 and 61 of one of the three ras genes, H-ras, K-ras and N-ras, convert these genes into active oncogenes. The presence of H-ras gene mutations have important prognostic implications in various cancers. In this study, the H-ras gene mutations were investigated by two-step PCRRFLP in patients with bladder and stomach cancer. For the control experiments, T24 and SK2 cell lines were used. In a total of 36 bladder cancer patient cases, five (13.9%) mutations were found by this method. Of these, point 12 mutations were two (5.6%) cases and point 61 mutations were three (8.3%) cases. On the other hand, H-ras mutation was not found in 29 cases of stomach cancer. The results of the mutated H-ras gene confirmed by direct sequencing analysis were correlated well with PCR analysis. From the sensitivity test, the H-ras mutation was found to have about 0.2% of mutated DNA mingled in normal DNA. In conclusion, the H-ras mutation has a higher clinical Significance in bladder cancer than stomach cancer. Moreover the two-step PCR-RFLP method is sensitive, rapid and relatively simple for clinical work in detecting H-ras point mutations.

Identification of novel alleles induced by EMS-mutagenesis in key genes of kernel hardness and starch biosynthesis in wheat by TILLING

Wenjie Li,Huijun Guo,Yongbin Wang,Yongdun Xie,Linshu Zhao,Jiayu Gu,Shirong Zhao,Baocun Zhao,Guangjin Wang,Luxiang Liu 한국유전학회 2017 Genes & Genomics Vol.39 No.4

To identify novel allelic variations in key genes of wheat quality, the present study used the targeting induced local lesions in genomes platform to detect point mutations in target genes. The wheat variety Longfumai 17 was treated by the mutagen ethyl methanesulfonate to produce a bulk M2 generation, and the population included 1122 plants. A total length of 3906.80 kb nucleotides was analyzed, and the average mutation density was 1/244.17 kb. The identified mutations included G>A substitutions (43.75%), C>T substitutions (31.25%), A insertions (12.50%), T insertions (6.25%), and deletions (6.25%). These point mutations led to changes in amino acids and thus the encoded protein sequences, ultimately producing 18.75% of missense mutations, 12.50% of frame shift mutations, 6.25% of nonsense mutations, 25.00% of silent mutations and 37.50% of non-coding region mutations. In the kernel hardness gene Pinb and 3 starch synthesis genes waxy, Agp2 and SSIIa-A, we detected 16 different point mutations in 25 mutant lines. The Pinb gene harbored two missense mutations and a nonsense mutation; the C>T missense mutation resulted in a novel allele, this novel allele and the nonsense mutation alerted protein 3D structure; the waxy gene presented missense and frame shift mutations; the Agp2 gene carried a missense mutation; the SSIIa-A incurred a missense mutation and a frame shift mutation that resulted in premature protein termination. All the frame shift mutations, nonsense mutations and the Pinb novel allele resulted in allelic variation of their corresponding genes, which in turn affected their gene functions. The identified mutant lines can be used as intermediate materials in wheat quality improvement schemes.

제주 지역에서 23S rRNA 점 돌연변이와 관련된 Clarithromycin 내성 Helicobacter pylori

김태윤 ( Taeyun Kim,),송현주 ( Hyun Joo Song ),신선영 ( Sun Young Shin ),김조헌 ( Jo Heon Kim ),나수영 ( Soo Young Na ),부선진 ( Sun Jin Boo ),최은광 ( Eun Kwang Choi ),조유경 ( Yoo Kyung Cho ),김흥업 ( Heung Up Kim ),송병철 ( Byu 대한소화기학회 2013 대한소화기학회지 Vol.61 No.5

Background/Aims: The point mutations in 23S rRNA gene accounts for the majority of the clarithromycin resistance of Helicobacterpylori. This study aimed to investigate the association between the clarithromycin-resistance of H. pylori and the failure of primary H. pylori eradication therapy in Jeju Island. Methods: Between April 2011 and October 2012, 6,937 patients underwent endoscopy, and H. pylori infection was evaluated in 2,287 patients (33.0%). Total of 110 patients with H. pylori infection were treated with proton pump inhibitor (PPI)-based triple therapy. The result of eradication was evaluated with urea breath test, histology and PCR which were conducted 4 weeks from the last dose of medicine. Results: The patients who had point mutations were 33 (26.0%). A2142G and A2143G mutations were observed in 10 patients (7.9%) and 23 patients (18.1%). Among 110 patients treated with PPI-based triple therapy, the success rate of the eradication therapy was 52.7% (58/110) and 70.7% (58/82) by intention-to-treat and per-protocol analysis, respectively. Fifteen of the 24 patients who failed the eradication therapy showed point mutations; 1 patient (4.2%) showed A2142G mutation and 14 patients (58.3%) showed A2143G mutation. Patients with A2143G mutation H. pylori showed higher failure rate of 87.5%. Patients with A2142G mutation H. pylori showed similar failure rate compared to those of the patients with wild type H. pylori. Conclusions: In Jeju Island, the frequency of 23S rRNA point mutations is similar (26.0%) with other regions of Korea (15.8-31.3%). A2143G mutation is associated with the failure of H. pylori eradication.

Osteosarcoma cybrids에서 미토콘드리아 tRNA^(Leu(UUR)) A3243G 점돌연변이에 의한 인슐린 저항성의 발생

지미홍,이완 동국대학교 의학연구소 2009 東國醫學 Vol.16 No.1

미토콘드리아의 산화적 인산화 능력과 ATP 합성 능력은 말초 조직에서 인슐린 감수성과 밀접한 관계가 있으며, 미토콘드리아 DNA (mitochondrial DNA, mtDNA) 변이는 당뇨병 발병의 중요한 요인으로 알려져 있다. 이와 더불어 MELAS 증후군 환자와 미토콘드리아성 당뇨병 환자에게서 mtDNA tRNA^(Leu(UUR))유전자의 뉴클레오티드 3243부분이 adenine (A)에서 guanine (G)으로 치환된 A3243G 점돌연변이가 관찰된다. 본 연구팀은 mtDNA A3243G 점돌연변이와 인슐린 저항성의 상관성을 밝히기 위해, mtDNA A3243G 점돌연변이 osteosarcoma cybrids에서 인슐린 유도에 의한 인슐린 신호전달 분자들의 발현과 인산화를 살펴보았다. mtDNA A3243G 점돌연변이가 있는 mutant cybrid는 단백질 합성이 감소한다는 보고가 있으나,적어도 인슐린 신호전달 분자들인 insulin receptor (IR), insulin receptor substrate-1 (IRS- I) , phosphatidylinositide 3 kinase (PI3K) , phosphatidylinositide dependent protein kinase-1 (PDK- I) 그리고 Akt의 발현에는 영향을 미치지 않았다. 흥미롭게도, 인슐린에 의해 유도되는 IRS-1과 Akt의 인산화는 A3243G 점돌연변이가 있는 mutant cybrid에서 유의하게 감소하므로, 인슐린 저항성의 발생과 관련이 있다는 것을 증명할 수 있었다. 따라서 본 연구결과 mtDNA A3243G 점돌연변이가 인슐린에 의해 유도되는 IRS-1의 인산화를 감소시켜 인슐린 저항성을 유발한다고 사료된다. Mitochondrial oxidative phosphorylation and the ATP production are closely correlated with the insulin sensitivity in peripheral tissues, and the mutations of mitochondrial DNA (mtDNA) are regarded as factors in the pathogenesis of diabetes. An adenine (A) to guanine (G) mutation in the tRNA^(Leu(UUR)) gene at nucleotide position 3243 (A3243G) of mitochondrial DNA (mtDNA) has been observed in patients with MELAS syndrome and mitochondrial diabetes. To elucidate the association of the mtDNA A3243G point mutation and insulin resistance, we investigated the expression and insulin-sensitive phosphorylation of insulin signaling intermediates in A3243G osteosarcoma cybrids. Although A3243G mutant cybrid reduced in protein synthesis rate, the expressions of insulin signaling intermediates such as insulin receptor (IR), insulin receptor substrate-1 (IRS-1), phosphatidylinositide 3 kinase (PI3K), phosphatidylinositide dependent protein kinase (PDK-1) and Akt were not affected by A3243G mutation. Interestingly, insulin-stimulated phosphorylations of IRS-1 and Akt were significantly reduced in A3243G mutant cybrid, clearly demonstrating that mtDNA A3243G mutation developed insulin resistance. We thus suggest that point mutation in mtDNA A3243G point mutation causes insulin resistance by reducing the insulin-stimulated tyrosine phosphorylation of IRS-1 in osteosarcoma cybrids.

구강암 세포주의 c-Ki-ras 2 유전자 발현 및 점돌연변이에 관한 연구

이의웅(Eui Wung Lee) 대한구강악안면외과학회 1994 대한구강악안면외과학회지 Vol.20 No.3

Five oral cancer cell lines, FaDu, HEp-2 SCC-4, 1483, OEC-M1, and one epidermoid carcinoma cell line, A-431, were examined for their expression level of c-Ki-ras 2 gene and the presence of activating mutations. Northern blot analysis revealed that the expression level of c-Ki-ras 2 mRNA of FaDu cells was 4 times that of primary cultured normal human oral keratinocytes (NHOK). OEC-M1 cells expressed mRNA of a little smaller size than normal and the expression level was much higher than in NHOK. Other cells expressed c-Ki-ras 2 mRNA at comparable levels to NHOK. DNA sequencing of c-Ki-ras 2 gene exon 1 and exon 2 was performed using polymerase chain reactionamplified DNA fragments. OEC-M1 cells had three point mutations in their c-Ki-ras 2 gene exon 1 and exon 2 resulting in amino acid substitutions, asparagine to aspartic acid, phenylalanine to leucine, and glycine to arginine at 24the, 28th and 53rd residues respectively. However, other cells had no mutation in their c-Ki-ras 2 gene exon 1 and exon 2. This result shows that abberant expression of c-ki-ras 2 gene and the point mutations are quite often associated with oral cancer.

HBV : PE-026 ; Effect of mutational complex genotype on HBsAg, HBeAg, and HBV DNA levels in chronic HBV carriers

( Jeong Won Jang ),( Min Ju Kim ),( Jung Hyun Kwon ),( Ji Yong Chun ),( Soo Kyung Shin ),( Sung Hong Yoo ),( Soo Ok Kim ),( Sun Pyo Hong ),( Young Min Park ) 대한간학회 2012 춘·추계 학술대회 (KASL) Vol.2012 No.-

Background: Mutational complex genotype (MCG) consisting of the number and pattern of mutations in the X/precore region of the hepatitis B virus (HBV) genome has been associated with advancement of liver disease. This study evaluated the effect of MCG on the levels of serum HBsAg, HBeAg, and HBV DNA in chronic HBV infection. Methods: Using sequencing and multiplex restriction fragment mass polymorphism analysis, eight hot-spot mutations (G1613A/C1653T/T1753V/A1762T/G1764A/A1846T/G1896A/G1899A) were evaluated in the sera from antiviral-naive 312 chronic carriers. Serum HBsAg and HBeAg were quantified as standardized units (ARCHITECT/Paul-Ehrlich-Institute standard, respectively). Results: Whereas almost all of the mutations had some association with decreased levels of HBsAg and HBeAg, the significance of these individual mutations was negligible when analyzed with all clinico-virological variables. The total number of mutations was the strongest independent factor affecting both antigen levels. Despite their good correlation in the HBeAgpositive stage, the association of mutation number with HBsAg was only modest in the HBeAg-negative stage, in which G1899A was the only HBsAg-associated mutation. Overall, there was a strong negative correlation between the number of mutations and HBeAg, in which a significant linear reduction in HBeAg levels was associated with mutation numbers ≥4. The effect of mutation number on their levels was more significant for HBsAg and HBeAg, but weak for HBV DNA. Of the mutations, G1896A and T1753V were independent factors for HBeAg negativity. Pattern analysis of the mutations revealed disparities in distribution among the top seven and ten highfrequency mutation combination patterns, which accounted for 40.8% and 4.8% of the low- and high-level HBsAg groups and 53.1% and 5.7% of the low- and high-level HBeAg groups, respectively. Conclusions: MCG in the X/precore region influences expression of serum HBsAg and HBeAg in the natural history of HBV infection and might be involved in the immunopathogenesis of chronic hepatitis B.