Biomedical subjects

Young Mi Kwon

Publications and source records attributed to Young Mi Kwon.

5 recordsLinked to original sources

PubMed2025

Cis-regulatory evolution of Wnt-family genes contributes to a morphological difference between silkworm species.

Closely related species often exhibit distinct morphologies that can contribute to species-specific adaptations and reproductive isolation. One example are Lepidopteran caterpillar appendages, such as the "caudal horn" of Bombycoidea moths, which have evolved substantial morphological diversity among species in this group. Using interspecific crosses, we identify the genetic basis of the caudal horn size difference between Bombyx mori and its closest relative B. mandarina. The three largest of eight QTL account for one third the mean horn length difference between the species. The largest of these, on chromosome 4, encompasses a conserved Wnt-family gene cluster, key upstream regulators that are well-known for their roles in morphological diversification in animals. Using allele-specific expression analysis and CRISPR/Cas9 knockouts, we show that tissue-specific cis-regulatory changes to Wnt1 and Wnt6 contribute to the species difference in caudal horn size. This kind of modularity enables highly pleiotropic genes, including key upstream growth regulators, to contribute to the evolution of morphological traits without causing widespread deleterious effects.

Journal Article↗

PubMed2006

Elevated mRNA levels of DNA methyltransferase-1 as an independent prognostic factor in primary nonsmall cell lung cancer.

BACKGROUND: Despite many reports about the involvement of DNA methyltransferases (DNMTs) in human cancers, including nonsmall cell lung cancer (NSCLC), the clinicopathologic significance of DNMTs in primary NSCLC remains to be elucidated. METHODS: The relation between the mRNA levels of DNMTs (1 and 3b) and the promoter methylation of the p16, RARbeta2, H-cadherin, GSTP1, RIZ, and FHIT genes and the clinicopathologic features in 102 fresh-frozen tissues and paraffin blocks were retrospectively studied. The mRNA levels of the DNMTs were assessed via semiquantitative reverse-transcription polymerase chain reaction (RT-PCR), and the methylation status of the CpG islands were determined by methylation-specific PCR. RESULTS: The mRNA levels of DNMT1 and DNMT3b were elevated in 53% and 58% of 102 NSCLCs, respectively. Hypermethylation of p16, RARbeta2, H-cadherin, GSTP1, RIZ, and FHIT occurred in 37%, 38%, 34%, 18%, 9%, and 31% of patients, respectively. Univariate analysis showed that elevated DNMT mRNA levels were not significantly associated with the hypermethylation of 6 genes. However, the elevated mRNA levels of DNMT1 were determined to be significantly associated with the hypermethylation of the p16 promoter (odds ratio [OR] = 2.70, 95% confidence interval [95% CI], 1.02-7.15; P = .02), after controlling for age, gender, pack-years smoked, histology, and pathologic stage. The hazard of failure in cases with elevated mRNA levels of DNMT1 was 3.51 (95% CI, 1.18-12.76; P = .02) times higher than that in those without. The elevated mRNA levels of DNMT3b were not ultimately associated with patient prognosis. CONCLUSIONS: Elevated mRNA expression of DNMT1 may be an independent prognostic factor in NSCLC and CpG island hypermethylation in NSCLC may be maintained by a complex interaction of several factors rather than by a simple transcriptional up-regulation of DNMT1.

Aged↗

PubMed2004

Tumor-specific methylation in bronchial lavage for the early detection of non-small-cell lung cancer.

PURPOSE: The aim of this study was to identify tumor-specific methylation in bronchial lavage for the early detection of non-small-cell lung cancer (NSCLC) by differentiating the age-related methylation from the tumor-specific methylation in NSCLC. PATIENTS AND METHODS: Eighty-five NSCLC patients and 127 cancer-free subjects participated in this study. Aberrant methylation at the promoters of the p16, Ras association domain family 1A (RASSF1A), fragile histidine triad (FHIT), H-cadherin, and retinoic acid receptor beta (RARbeta) genes were evaluated in the resected tumor tissues and bronchial lavage samples of NSCLC patients and in the bronchial lavage samples of cancer-free subjects by methylation-specific polymerase chain reaction. RESULTS: Of the 127 cancer-free samples, methylation was detected in 6% for p16, 13% for RARbeta, 3% for H-cadherin, 4% for RASSF1A, and 28% for FHIT. Hypermethylation of the p16, RARbeta, H-cadherin, and RASSF1A genes was not associated with patient age and smoking, whereas hypermethylation of the FHIT promoter occurred more frequently in older patients (P =.02) and was associated with exposure to tobacco smoke (P =.001). A strong correlation between age and smoking was found in patients with hypermethylation of the FHIT gene (r = 0.36; P =.03). A total of 68% of the bronchial lavage samples from the 85 NSCLC patients showed methylation of at least one of p16, RARbeta, H-cadherin, and RASSF1A genes. CONCLUSION: Our study suggests that tumor-specific methylation of the p16, RASSF1A, H-cadherin, and RARbeta genes may be a valuable biomarker for the early detection of NSCLC in bronchial lavage, and that the age-related methylation of FHIT gene in the normal bronchial epithelium is related to the exposure to tobacco smoke.

Acid Anhydride Hydrolases↗

PubMed2003

Relationship of Ras association domain family 1 methylation and K-ras mutation in primary non-small cell lung cancer.

Recently, several groups have reported that Ras association domain family 1 (RASSF1A) interacts with Ras and mediates Ras-dependent apoptosis. However, the mechanism by which RASSF1A plays a role as a tumor suppressor in human cancer is unclear. In this study, we investigated the relationship between the RASSF1A methylation and K-ras mutation and their effects on patient's survival in 242 primary non-small cell lung cancers (NSCLCs) to understand the role of RASSF1A in Ras-mediated oncogenic transformation. RASSF1A methylation was not found to be associated with the K-ras mutation in NSCLCs (P = 0.37). For patients with stage I adenocarcinoma, those with RASSF1A methylation and K-ras mutation had a poorer prognosis than those with either RASSF1A methylation or K-ras mutation (P = 0.001). In stage II-III adenocarcinoma patients, the median survival of those with RASSF1A methylation and K-ras mutation was 9 months, and this was poorer than that of those with either RASSF1A methylation or K-ras mutation (P = 0.001). The hazard of failure for those with RASSF1A methylation and K-ras mutation was approximately 2.94 times higher compared with that of those with neither K-ras mutation nor RASSF1A methylation (95% confidence interval = 1.67-9.42; P = 0.01). Our results suggest that RASSF1A methylation and K-ras mutation are not mutually exclusive in NSCLC. In addition, RASSF1A methylation, in combination with K-ras mutation, may have an adverse synergistic effect on patient's survival in NSCLCs.

Aged↗

PubMed2003

Mesenteric Buerger's disease.

A young male patient with a history of heavy smoking and low-extremity Buerger's disease was operated on because of small bowel infarction. The postoperative histopathological diagnosis was mesenteric involvement of Buerger's disease. Mesenteric Buerger's disease is extremely rare, the early diagnosis is difficult, and the prognosis is poor. Considering the difficulty in diagnosis and the poor prognosis, patients with Buerger's disease presenting with gastrointestinal manifestations should be carefully evaluated, and early surgical intervention is recommended.

Humans↗