Biomedical subjects

Seong-Doo Hong

Publications and source records attributed to Seong-Doo Hong.

4 recordsLinked to original sources

PubMed2006

Oligonucleotide microarray analysis of ameloblastoma compared with dentigerous cyst.

BACKGROUND: Ameloblastoma is a benign, but locally invasive tumor known for its high rate of recurrence. However, few comprehensive genetic studies have been conducted about its tumorigenesis. Our aim was to identify possible genes involved in the development and progression of ameloblastoma, using microarray analysis with dentigerous cyst as a control. METHODS: Total RNA was extracted from two fresh dentigerous cysts and ameloblastoma specimens. Following microarray analysis, semiquantitative reverse transcription-polymerase chain reaction (RT-PCR) and immunohistochemistry were performed on selected genes. RESULTS: Seventy-three genes were overexpressed and 49 were underexpressed. These genes were divided into categories according to function. The microarray results for 13 selected genes were verified with semiquantitative RT-PCR. CONCLUSIONS: We identified important genes related to the development and progression of ameloblastoma through a large-scale gene expression analysis. This study will stimulate further investigations on genes significant for early diagnosis and prognosis of ameloblastoma.

Adolescent↗

PubMed2005

Electrospinning of collagen nanofibers: effects on the behavior of normal human keratinocytes and early-stage wound healing.

Electrospinning of type I collagen in 1,1,1,3,3,3-hexafluoro-2-propanol (HFIP) to fabricate a biomimetic nanofibrous extracellular matrix for tissue engineering was investigated. The average diameter of collagen nanofibers electrospun from 8% collagen solution in HFIP was 460 nm (range of 100-1200 nm). The as-spun collagen nanofibrous matrix was chemically cross-linked by glutaraldehyde vapor with a saturated aqueous solution and then treated with aqueous 0.1m glycine to block unreacted aldehyde groups. With vapor phase cross-linking for 12h, porosity of the collagen matrix decreased from 89% to 71%. The collagen nanofibrous matrix showed good tensile strength, even in aqueous solution. Effects on cytocompatibility, cell behavior, cell and collagen nanofiber interactions, and open wound healing in rats were examined. Relatively low cell adhesion was observed on uncoated collagen nanofibers, whereas collagen nanofibrous matrices treated with type I collagen or laminin were functionally active in responses in normal human keratinocytes. Collagen nanofibrous matrices were very effective as wound-healing accelerators in early-stage wound healing. Our results indicate that cross-linked collagen nanofibers coated with ECM proteins, particularly type I collagen, may be a good candidate for biomedical applications, such as wound dressing and scaffolds for tissue engineering.

Adult↗

PubMed2004

Inactivation patterns of p16/INK4A in oral squamous cell carcinomas.

The p16/INK4A is one of the major target genes in carcinogenesis and its inactivation has frequently been reported in other types of tumors. The purpose of this study is to evaluate inactivation patterns of p16/INK4A in oral squamous cell carcinoma. Six different oral cancer cell lines, SCC-4, SCC-9, SCC-15, SCC-25, KB, and SNUDH- 379 were examined for inactivation of p16/INK4A genes. In the analysis of p16/INK4A gene inactivation, PCR amplification, direct sequencing, and methylation-specific PCR methods were adopted for evaluation of homozygous deletion, point mutation, and promoter hypermethylation, respectively. Homozygous deletion was detected in SCC-25 and SCC-9. SCC-15 showed hypermethylated promoter region within p16/INK4A gene. It is suggestive in the present study that inactivation patterns of p16/INK4A were mainly homozygous deletion, promoter methylation rather than point mutation in oral squamous cancer cell lines, so treatment modalities of oral squamous cell carcinoma should be focused on these types of inactivation.

Carcinoma, Squamous Cell↗

PubMed2002

Expression of membrane type I-matrix metalloproteinase in oral squamous cell carcinoma.

A local invasion and lymph node metastasis (LNM) of an oral squamous cell carcinoma (OSCC) has a poor prognosis, and involves the degradation of the extracellular matrix mediated by multiple proteolytic enzymes including membrane type I-matrix metalloproteinase (MT1-MMP). This study aimed to determine the role of MT1-MMP in OSCC, to evaluate the immunohistochemical expression of MT1-MMP with regard to the invasiveness and LNM of the OSCC, and to evaluate the major source of MT1-MMP mRNA and its protein using immunohistochemistry and in situ hybridization. MT1-MMP expression was examined in 46 OSCCs via immunohistochemistry and non-radioisotope in situ hybridization. The relationship between MT1-MMP expression and LNM, as well as the histological invasiveness, was statistically analyzed. The results showed that whereas 12 out of the 18 OSCCs (66.7%) with LNM showed moderate to strong MT1-MMP expression, only nine of the 28 OSCCs (32.1%) without LNM expressed MT1-MMP strongly. MT1-MMP expression was significantly higher with regard to LNM (P=0.022). As the invasion grade became stronger (from grade a to grade d), MT1-MMP was significantly more strongly expressed (P=0.033). These results suggest that MT1-MMP is primarily secreted in the OSCC cells and is involved in the invasiveness of the OSCC and LNM. Moreover, MT1-MMP combined with other markers may be used to predict the metastatic potential of an OSCC.

Adult↗