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Il-Jin Kim

Publications and source records attributed to Il-Jin Kim.

At least 19 recordsLinked to original sources
PubMed2007

Correlation between hypermethylation of the RASSF2A promoter and K-ras/BRAF mutations in microsatellite-stable colorectal cancers.

Recently, RASSF2A was identified as a potential tumor suppressor epigenetically inactivated in human cancers. Here, we evaluated the methylation status of RASSF2A in colorectal cancer (CRC) and analyzed its correlation with K-ras/BRAF mutations, microsatellite instability status and other clinicopathological features. Using methylation-specific PCR and bisulfite sequencing, we analyzed the methylation status in primary CRC, adenomas and corresponding normal tissues and then compared it with the presence of K-ras and BRAF mutations. We also examined the expression and methylation status of RASSF2A in CRC cell lines. We found that aberrant methylation of RASSF2A promoter regions is associated with gene silencing in CRC cell lines. In primary CRC, the frequency of RASSF2A methylation was 72.6%, and it was found in 16 of 16 (100%) adenomas. In addition, there was a positive correlation between K-ras/BRAF mutations and RASSF2A methylation in primary CRC. Furthermore, a significant positive correlation between K-ras/BRAF mutations and RASSF2A methylation was also observed in microsatellite-stable (p = 0.033) and distal CRC (p = 0.025). These results show that RASSF2A methylation is a frequent event in colorectal tumorigenesis and positively correlates with K-ras/BRAF mutation in microsatellite-stable or distal CRC.

Adenoma↗
PubMed2006

Establishment and characterization of cell lines from three human thyroid carcinomas: responses to all-trans-retinoic acid and mutations in the BRAF gene.

We report the characteristics of three cell lines (designated, SNU-80, SNU-373 and SNU-790), which were established from two papillary carcinomas and one anaplastic carcinoma obtained from three Korean thyroid carcinoma patients. All cell lines grow as adherent cells. Electron microscopy characteristically showed cytoplasmic invaginations of nuclei and intranuclear cytoplasmic inclusions. SNU-80 and SNU-790 cells showed a positive reaction to anti-cytokeratin antibody, and SNU-790 cells positivity for CK-19. All lines were free of mycoplasma or bacteria and were proven unique by DNA fingerprinting analysis. The p15 and p16 genes are deleted in the SNU-790 line. Mutations of the p53 gene were found in two lines (SNU-80 and SNU-373), but no mutations in the RET or MEN1 genes were observed. Mutations of the BRAF gene were found in the SNU-80 (G468R) and the SNU-790 (V599E) cell lines, but no mutations in the K-ras gene were present. SNU-80 and SNU-790 cells showed a positive reaction to anti-cytokeratin antibody, and no evidence of the production of thyroglobulin or calcitonin was observed. The cell lines were unable to trap radioactive iodine but did not contain TSH receptor. In addition, we investigated the mRNA expression levels of Tg, TSHR, TTF-1, PAX-8, NIS, IL-6, and LIF, and of the alpha, beta and gamma retinoic acid receptors in these cell lines. IL-6 was down-regulated in all three cell lines by all-trans-retinoic acid treatment. RAR-alpha was expressed but RAR-beta was not expressed in the three cell lines, and RAR-gamma was not expressed in SNU-790. Interestingly, RAR-beta (SNU-80 and SNU-373) and RAR-gamma (SNU-790) was up-regulated by all-trans-retinoic acid treatment. We believe that these well-characterized thyroid carcinoma cell lines may be useful tools for investigations on the biological characteristics of thyroid carcinoma, particularly for investigations related to gene alterations, especially of the BRAF gene. These cell lines may also be useful for redifferentiation therapy studies on thyroid carcinoma using all-trans-retinoic acid.

Antineoplastic Agents↗
PubMed2006

Analysis of microsatellite instability in stool DNA of patients with colorectal cancer using denaturing high performance liquid chromatography.

AIM: To evaluate the usefulness of denaturing high performance liquid chromatography (DHPLC) for analyzing microsatellite instability (MSI) status in stool DNA of patients with colorectal cancer. METHODS: A total of 80 cancer tissues from patients with primary sporadic colorectal tumor (proximal cancer: 27, distal cancer: 53) and matched stool (which were employed for comparison with the tissues) were analyzed for MSI status in BAT 26. DNA samples extracted from stool were evaluated by nested polymerase chain reaction (PCR) and DHPLC for MSI analysis. RESULTS: Six cases (7.5%) of MSI were identified in BAT 26 from 80 cancer tissues. All the stool DNA samples from patients whose cancer tissue showed MSI also displayed MSI in BAT 26. CONCLUSION: As MSI is one of the established fecal DNA markers to screen colorectal cancer, we propose to use DHPLC for the MSI analysis in fecal DNA.

Biomarkers, Tumor↗
PubMed2006

Promoter hypomethylation and reactivation of MAGE-A1 and MAGE-A3 genes in colorectal cancer cell lines and cancer tissues.

AIM: To verify the expression and methylation status of the MAGE-A1 and MAGE-A3 genes in colorectal cancer tissues and cancer cell lines. METHODS: We evaluated promoter demethylation status of the MAGE-A1 and MAGE-A3 genes by RT-PCR analysis and methylation-specific PCR (MS-PCR), as well as sequencing analysis, after sodium bisulfite modification in 32 colorectal cancer cell lines and 87 cancer tissues. RESULTS: Of the 32 cell lines, MAGE-A1 and MAGE-A3 expressions were observed in 59% and 66%, respectively. Subsequent to sodium bisulfite modification and MS-PCR analysis, the promoter hypomethylation of MAGE-A1 and MAGE-A3 was confirmed in both at 81% each. Promoter hypomethylation of MAGE-A1 and MAGE-A3 in colorectal cancer tissues was observed in 43% and 77%, respectively. Hypomethylation of MAGE-A1 and MAGE-A3 genes in corresponding normal tissues were observed in 2% and 6%, respectively. CONCLUSION: The promoter hypomethylation of MAGE genes up-regulates its expression in colorectal carcinomas as well as in gastric cancers and might play a significant role in the development and progression of human colorectal carcinomas.

Antigens, Neoplasm↗
PubMed2006

Genetic alterations of the TGF-beta signaling pathway in colorectal cancer cell lines: a novel mutation in Smad3 associated with the inactivation of TGF-beta-induced transcriptional activation.

To investigate genetic alterations involved in the TGF-beta signaling pathway in colorectal cancer, we assayed DNA synthesis rates after treating TGF-beta and checked for genetic alterations in TGF-betaRII, TGF-betaRI, Smad2, Smad3, and Smad4 in 12 colorectal cancer cell lines. Eleven lines, except SNU-61, show no significant change in DNA synthesis rate after TGF-beta treatment. In these 11 lines, several mutations were found in genes involved in the TGF-beta signaling pathway: (i) frameshift deletions in the poly(A)(10) tract of the TGF-betaRII gene in SNU-407, SNU-769A, SNU-769B, and SNU-1047 cell lines, (ii) a missense mutation of Smad2 (R321Q) in SNU-81, (iii) two missense mutations in TGF-betaRI (R487W in SNU-175 and A202V in SNU-1040), and (iv) a monoallelic loss at the Smad4 locus in three cell lines. Interestingly, a missense mutation (R373H) in Smad3 gene was found in SNU-769A. To our knowledge, this is the first report of Smad3 mutation in human malignancy. This mutation was found to result in the inhibition of translocation of Smad3 protein to the nucleus and a reduction in the activity of Smad3 during TGF-beta-induced transcriptional activation. These results indicate that the majority of cell lines, which are insensitive to TGF-beta, have alterations in genes involved in the TGF-beta signaling pathway in colorectal cancer cell lines.

Base Sequence↗
PubMed2006

Novel polymorphisms in the SUV39H2 histone methyltransferase and the risk of lung cancer.

Histone H3 lysine 9 (H3-K9) methylation and DNA methylation are important features of mammalian heterochromatin. Suppressor of variegation 3-9 homolog 2 (SUV39H2) is the histone methyltransferase that is required to methylate H3-K9, leading to transcriptional repression or silencing of target genes. In this study, we investigated the association of SUV39H2 polymorphisms and the risk of lung cancer. From the results of PCR direct sequencing, eight single nucleotide polymorphisms (SNPs) of SUV39H2 were identified in Korean population. In a hospital-based study of 346 lung cancer patients and 423 healthy controls, a novel SNP in the 3'-UTR of SUV39H2 (1624 G-->C) was associated with a statistically significant increase in lung cancer risk. Compared to the G/G genotype, genotypes with 1624C allele (G/C + C/C) significantly increased the susceptibility to lung cancer with adjusted odds ratio (AOR) of 2.63 (95% confidence interval (CI)= 1.10-6.29) for ever-smokers, especially in the older age group (age >or=55 years). Specifically, the variant genotype of 1624SNP was significantly associated with an increased risk of squamous cell carcinoma (AOR, 3.52; 95% CI = 1.13-9.45) in the older age group, while no significant association was found in patients with other histology. This study provided the first evidence that a novel SUV39H2 polymorphism may be an important predictive marker for lung cancer susceptibility for the smokers.

3' Untranslated Regions↗
PubMed2006

Germ line mutations of mismatch repair genes in hereditary nonpolyposis colorectal cancer patients with small bowel cancer: International Society for Gastrointestinal Hereditary Tumours Collaborative Study.

PURPOSE: The aim of study was to determine the clinical characteristics and mutational profiles of the mismatch repair genes in hereditary nonpolyposis colorectal cancer (HNPCC) patients with small bowel cancer (SBC). EXPERIMENTAL DESIGN: A questionnaire was mailed to 55 members of the International Society for Gastrointestinal Hereditary Tumours, requesting information regarding patients with HNPCC-associated SBC and germ line mismatch repair gene mutations. RESULTS: The study population consisted of 85 HNPCC patients with identified mismatch repair gene mutations and SBCs. SBC was the first HNPCC-associated malignancy in 14 of 41 (34.1%) patients for whom a personal history of HNPCC-associated cancers was available. The study population harbored 69 different germ line mismatch repair gene mutations, including 31 mutations in MLH1, 34 in MSH2, 3 in MSH6, and 1 in PMS2. We compared the distribution of the mismatch repair mutations in our study population with that in a control group, including all pathogenic mismatch repair mutations of the International Society for Gastrointestinal Hereditary Tumours database (excluding those in our study population). In patients with MSH2 mutations, patients with HNPCC-associated SBCs had fewer mutations in the MutL homologue interaction domain (2.9% versus 19.9%, P = 0.019) but an increased frequency of mutations in codons 626 to 733, a domain that has not previously been associated with a known function, versus the control group (26.5% versus 2.8%, P < 0.001). CONCLUSIONS: In HNPCC patients, SBC can be the first and only cancer and may develop as soon as the early teens. The distribution of MSH2 mutations found in patients with HNPCC-associated SBCs significantly differed from that found in the control group (P < 0.001).

Adaptor Proteins, Signal Transducing↗
PubMed2006

Regulation of MDK expression in human cancer cells modulates sensitivities to various anticancer drugs: MDK overexpression confers to a multi-drug resistance.

MDK is a heparin-binding growth factor associated with cancer development. Here, we sought to examine the association of MDK expression with resistance and sensitivity to different chemotherapeutic agents. We established stable HeLa cell transfectants (HeLa-MDK) and tested for decreased sensitivity to chemotherapeutic agents (5-FU, doxorubicin, and cisplatin). In addition, we used siRNA to block MDK expression in SNU-638 human gastric cancer cells and examined the chemosensitizing effect. HeLa-MDK cells treated with 5-FU, doxorubicin, and cisplatin showed a fold increase in the average IC(50) and an increased cell survival. siRNA-based knockdown of MDK expression in SNU-638 cells decreased the average IC(50) by 18-44% in cells treated with three drugs. Further investigations on the molecular mechanism should be clarified, but these results indicate that MDK up- and down-regulation appears to be capable of changing the chemosensitivities of cancer cells and MDK may have possible importance as a candidate therapeutic molecule.

Antineoplastic Agents↗
PubMed2005

Oligonucleotide microarray analysis of distinct gene expression patterns in colorectal cancer tissues harboring BRAF and K-ras mutations.

Various types of human cancers harbor BRAF somatic mutations, leading researchers to seek molecular targets for BRAF inhibitors. A mutually exclusive relationship has been observed between the BRAF-V600E mutation and K-ras mutations, suggesting that the BRAF-V600E mutation may differ from the other BRAF mutant types. Here, we used microarray analysis to examine differences between the BRAF and K-ras mutant colorectal samples and within the BRAF group (V600E versus non-V600E), in the hope that the identified gene sets could form the basis for new target development. Eleven colorectal cancers (CRCs) with BRAF mutations and nine with K-ras mutations were examined by high-density microarray analysis. We also tested whether other significant genetic or clinical status involved in CRC development, such as APC and TP53 mutations, MSI and TNM-Duke's staging, were related with the observed BRAF- or K-ras associated expression profiles. Unsupervised two-way hierarchical clustering and multidimensional scaling revealed that the differentially expressed genes clustered according to the mutation status of BRAF and K-ras, and that samples with the BRAF-V600E and non-V600E mutants could be distinguished from each other by gene profiling. Examination of TNM-Duke's staging, MSI and mutations in APC and TP53 revealed that these significant mutations could not account for the hierarchical clustering results observed in our study. We herein identified distinct gene expression patterns and gene sets that may form the basis for identification of BRAF-targeting molecules or provide researchers with a better understanding of the molecular pathogenesis underlying RAS-RAF signaling.

Colorectal Neoplasms↗
PubMed2005

Mutation spectrum of the APC gene in 83 Korean FAP families.

Familial adenomatous polyposis (FAP) is a clinically well-defined hereditary disease caused by germline mutations in the adenomatous polyposis coli (APC) gene. FAP is characterized by polyposis in the large bowel and variable extracolonic manifestations. With an increase of reported APC germline mutations, many reports have investigated genotype-phenotype correlations in FAP patients. Here, we analyzed the APC gene for germline mutations in 83 unrelated Korean FAP patients and investigated genotype-phenotype correlations. We identified germline APC mutations in 59 (71%) of the cases, including 34 frameshift mutations, 19 nonsense mutations, and six splice site mutations. Among 59 patients with the identified germline mutation of the APC gene, 37 had been reported previously and were included in the genotype-phenotype analysis. In the other 22 patients, we identified seven novel mutations: c.1438C>T, c.2232_2233dupCT, c.3426delT, c.3739_3769del31, c.3931_3935delATTGG, c.4332dupA, and c.4722_4725delACTA. Desmoid tumors were identified in six of the examined FAP patients, five of whom had APC germline mutations; these mutations involved codons 849, 864, 1309, 1444 and 1464, respectively (c.2547_2548delTA, c.2592_2593insCT, c.3927_3931delAAAGA, c.4332dupA and c.4391-4394delAGAG). Four of the included FAP patients had papillary thyroid cancers; all were female and had germline APC mutations (c.1863_1865delTTAincCT, c.2805C>A, c.3183_3187delACAAA and c.3927_3931delAAAGA).

Adenomatous Polyposis Coli↗
PubMed2005

Bax, a predictive marker for therapeutic response to preoperative chemoradiotherapy in patients with rectal carcinoma.

In an attempt to improve local control and survival in patients with advanced rectal carcinoma, neoadjuvant chemoradiation therapy (CRT) has been increasingly used in patient management. However, a significant proportion of patients shows poor response to adjuvant CRT. Thus, the ability to predict CRT responsiveness in patients with rectal cancer would benefit effective management. Several molecular markers related to regulation of cell cycle, apoptosis, or DNA repair have been proposed as candidate predictors of therapeutic response to CRT, but, to date, none has been definitively proven to be predictive of CRT response. To evaluate the use of various molecular markers as predictors of the response to CRT in rectal carcinoma, we investigated immunohistochemical expressions of p53, p21 WAF1/CIP1 , Bcl-2, Bax, Ki-67, Ku-70, and 2 new candidate markers (histone deacetylase 1 and metabotropic glutamate receptor 4) in pretreatment biopsy samples of 130 rectal carcinomas. We further compared the expressions of these molecular markers with the pathological responses of the tumors after therapy. We found that Bax expression, among the markers studied, was exclusively related to tumor regression. Its expression was significantly higher in the complete response group as compared with the partial response group (54% versus 29%, P = .017). This result confirms that apoptosis plays an important role in tumor response to CRT and provides evidence that Bax may serve as a predictable molecular marker for chemoradiosensitivity in rectal carcinoma.

Adult↗
PubMed2005

[Hereditary colorectal cancer].

Hereditary syndromes cause approximately 5 to 15% of overall colorectal cancer (CRC) cases. Hereditary CRC is conventionally divided into two major categories: hereditary non-polyposis colorectal cancer (HNPCC) and those related to polyposis syndromes including familial adenomatous polyposis (FAP), Peutz-Jegher syndrome (PJS), and juvenile polyposis (JP). The screening for the cancer and methods of treatment applied to patients with hereditary CRC are quite different from those applied to the general population. The genes responsible for these syndromes has recently identified, as a result, genetic testing has become the most important determining factor in clinical decisions. Germ-line mutation of the APC gene induces FAP, an autosomal dominant disorder, characterized by the development of hundreds to thousands of colonic adenomas. CRC appears in almost all affected individuals by the time they are 50 years of age. An affected individual should undergo colectomy by his/her late teens. Furthermore, according to the findings of genetic testing, at-risk family members also need endoscopic surveillance and surgery. Recently, a mutation on the MYH gene is increasingly being investigated in patients with multiple polyps, and autosomal recessive MYH polyposis is considered to be a new category of polyposis. More common than FAP, HNPCC is caused by germ-line mutations in DNA mismatch repair genes, mainly MLH1 and MSH2. Although there is no polyposis, polyps seem to be more villous and dysplastic and appear to grow rapidly into CRCs. The aggregate lifetime risk of CRC is about 80% for mutation carriers. The risk for other types of cancer, such as endometrial, ovarian, small bowel, and transitional cell cancer, is also increased. The Amsterdam criteria and Bethesda guidelines are the best-known tools for diagnosis and genetic testing, and colectomy followed by endoscopic follow-up is the standard treatment. PJS and JP are reported to be characterized by hamartomatous polyps throughout the GI tract and germ-line mutations in the STK11 gene (PJS) and the DPC4/BMPR1A gene (JP).

Adenomatous Polyposis Coli↗
PubMed2005

Three novel VHL germline mutations in Korean patients with von Hippel-Lindau disease and pheochromocytomas.

Von Hippel-Lindau (VHL) disease is an autosomal dominant inherited tumor syndrome associated with germline mutations in the VHL gene. VHL disease, as well as several other cancer syndromes, has been associated with an increased risk of pheochromocytomas, which are catecholamine-secreting tumors of the adrenal gland. VHL disease genotype-phenotype correlations have been well established based on the type of mutations in the VHL gene. However, although many groups have reported VHL germline mutations in different countries, no previous report has described VHL gene mutations in VHL disease and/or pheochromocytoma patients in Korea. In this study, we used direct sequencing to investigate VHL germline mutations in Korean patients with VHL disease or pheochromocytomas (11 VHL patients and 3 additional members from 7 families, 2 patients from 1 family with familial pheochromocytoma, and 2 cases of isolated pheochromocytoma). We found a total of 7 VHL germline mutations (6 missense and 1 frameshift), 3 of which were novel (323_324delGC, 355T>C and 361G>A). No VHL germline mutation was found in the 2 patients with isolated pheochromocytomas and paragangliomas. This study provides informative data for VHL germline mutations and VHL-related phenotypes in Korea.

Adrenal Gland Neoplasms↗
PubMed2004

A Novel IVS2-1G>A mutation causes aberrant splicing of the HRPT2 gene in a family with hyperparathyroidism-jaw tumor syndrome.

HRPT2, the gene associated with hyperparathyroidism-jaw tumor (HPT-JT) syndrome, was previously mapped to 1q24-q32. It was recently cloned, and several germline mutations were found to predispose to HPT-JT syndrome. We sequenced the complete HRPT2 coding sequence and splice-junctional regions in a Korean family with HPT-JT syndrome and identified a novel germline mutation, IVS2-1G>A in intron 2, that caused the autosomal dominant trait of HPT-JT syndrome in this family. RT-PCR and sequencing of the transcripts revealed that this splicing mutation generated alternative splicing errors leading to the formation of two different transcripts, one with exon 3 deleted, the other lacking the first 23 bp of exon 3 due to the use of an internal splice acceptor in exon 3. Translation of both transcripts results in premature termination. In addition, we detected two novel somatic mutations of HRPT2 in malignant parathyroid tumors from the affected individuals. One, 85delG, causes premature termination; the other, an 18 bp in-frame deletion of 13_30delCTTAGCGTCCTGCGACAG, suggests that this region may be important in the development of the parathyroid carcinomas in HPT-JT syndrome. These findings provide further evidence that mutation of HRPT2 is associated with the formation of parathyroid tumors in HPT-JT syndrome.

Adult↗
PubMed2004

A TP53-truncating germline mutation (E287X) in a family with characteristics of both hereditary diffuse gastric cancer and Li-Fraumeni syndrome.

Mutations in CDH1, which encodes E-cadherin, have been associated with hereditary diffuse gastric cancer (HDGC) in Western populations but have not been shown to play a major role in Asians. Recently, a patient with familial gastric cancer (FGC) was shown to harbor a germline mutation in the TP53 gene, which encodes p53 and has been previously associated with Li-Fraumeni Syndrome (LFS). To determine whether mutations in TP53 are associated with FGC in Asians, we screened the entire coding region of TP53 in probands from 23 Korean FGC families. We identified a nonsense (E287X) TP53 germline mutation in a family whose history is compatible with both HDGC and LFS. Two members of this family (SNU-G2) were afflicted with brain tumors, seven with gastric cancers, two with sarcomas, and one with both gastric cancer and a sarcoma. The E287X TP53 mutation segregated with the cancer phenotype in the family members from whom DNA samples were available. To our knowledge, this is the first report of a large family with both HDGC and LFS. Our results suggest that TP53 mutational screening in FGC families should be interpreted with caution because additional TP53 mutation-carrying HDGC families may also show LFS-related phenotypes.

Base Sequence↗
PubMed2004

Promoter hypermethylation downregulates RUNX3 gene expression in colorectal cancer cell lines.

It was recently reported that RUNX3 gene expression is significantly downregulated in human gastric cancer cells due to hypermethylation of its promoter region or hemizygous deletion (Cell, 109, 2002). To verify the genetic alterations and methylation status of the RUNX3 gene in colorectal carcinogenesis, we analysed for mutations, loss of heterozygosity (LOH), and RUNX3 gene promoter hypermethylation, in 32 colorectal cancer cell lines. RT-PCR analysis showed undetectable or low RUNX3 expression in 16 cell lines, and no mutations were found in the RUNX3 gene by PCR-SSCP analysis. Of these 16 cell lines, hypermethylation of the RUNX3 promoter was confirmed in 12. The following observations were made: (i) RUNX3 was re-expressed after 5-aza-2'-deoxycytidine treatment, (ii) the RUNX3 promoter was found to be methylated by MS-PCR, and (iii) hypermethylation of the RUNX3 promoter was confirmed by direct sequencing analysis after sodium bisulfite modification in the above 12 cell lines. RUNX3 was neither methylated nor expressed in four cell lines. Of these four, microsatellite instability (MSI) at the RUNX3 locus was found in three, SNU-61 (D1S246), SNU-769A, and SNU-769B (D1S199). This study suggests that transcriptional repression of RUNX3 is caused by promoter hypermethylation of the RUNX3 CpG island in colorectal cancer cell lines, and the results of these experiments may contribute to an understanding of the role of RUNX3 inactivation in the pathogenesis of colorectal cancers.

Base Sequence↗