Biomedical subjects

Hye-Rin Park

Publications and source records attributed to Hye-Rin Park.

3 recordsLinked to original sources

PubMed2004

The E-cadherin -347G->GA promoter polymorphism and its effect on transcriptional regulation.

E-cadherin plays a critical role in epithelial cell-cell adhesion and maintenance of tissue architecture. Loss of E-cadherin expression in humans has been associated with cancer, and a number of cancer-related mutations have been identified. Here, we sought to investigate whether the -347G-->GA single nucleotide polymorphism affects the transcriptional activity of the E-cadherin gene. First, we measured the promoter activity of the -347G-->GA polymorphism using a dual luciferase reporter assay and electrophoretic mobility shift assay (EMSA). The dual luciferase reporter assay showed that the GA allele decreased the transcriptional efficiency by 10-fold (P < 0.001) compared with the G allele. Similarly, EMSA revealed that the GA allele had a weak transcription factor binding strength compared with the G allele. We then examined the frequency of this polymorphism in familial gastric cancer (FGC) patients by denaturing high-performance liquid chromatography. We found that the E-cadherin genotype (-347G/GA heterozygous or GA homozygous) was associated with FGC patients (P < 0.05) compared with the G homozygous genotype. Taken together, these results suggest that the GA allele may cause weak transcription factor binding affinity and low transcriptional activity in E-cadherin expression.

Alleles↗

PubMed2003

Mutational analysis of BRAF and K-ras in gastric cancers: absence of BRAF mutations in gastric cancers.

Recently, BRAF mutations were found in a variety of human cancers. Interestingly, the most common of BRAF mutation (V599E) has not been identified in tumors with K-ras mutations. Whereas the majority of human cancer types has been screened for BRAF mutations, no detailed studies on gastric cancers have been investigated. Thus, we decided to investigate the incidence of BRAF mutations in gastric cancers, and the relationship between BRAF and K-ras mutations in such cancers. Three non-pathogenic BRAF polymorphisms and seven K-ras missense mutations were found in 66 gastric cancers and 16 gastric cancer cell lines. Although only 9% of our gastric cancer panels had K-ras mutations, the incidence of BRAF mutations was not high. Thus, BRAF mutations, which are present in a variety of other human cancers, do not seem to be involved in gastric cancer development.

Base Sequence↗

PubMed2003

Robust microsatellite instability (MSI) analysis by denaturing high-performance liquid chromatography (DHPLC).

Microsatellite instability (MSI) plays an important biological role in various types of cancers, and especially in colorectal cancers. This study aimed to develop a simple, efficient, new method for robust MSI analysis. DNA was extracted from 175 (105 proximal colon and 70 distal colorectal) cancer samples and matched normal tissues, and five Bethesda microsatellite markers (BAT-25, BAT-26, D5S346, D2S123, and D17S250) were examined for MSI by denaturing high-performance liquid chromatography (DHPLC) analysis at a temperature of 50 degrees C and a flow rate of 0.9 ml/min. It took just 9 min per PCR product to determine MSI or microsatellite stability (MSS) using the new protocol. The DHPLC results were confirmed with conventional gel-based electrophoresis and capillary-based sequencing method. Of 175 samples, 45 (26%) showed high microsatellite instability (MSI-H), 12 (7%) showed low microsatellite instability (MSI-L), and 118 (67%) showed MSS. All MSI samples were deletion mutants and all 12 MSI-L cases had MSI in dinucleotide markers (D5S346, D2S123, and D17S250). MSI was significantly associated with proximal colon cancers ( p<0.0001), as previously reported. The MSI-H tumors were also associated with tumor node metastasis (TNM) I/II stages ( p=0.05) and high-grade tumors ( p<0.01). Here, we propose a DHPLC-based method as an alternative for MSI analysis.

Chemistry Techniques, Analytical↗