Biomedical subjects

Ching-Yu Yen

Publications and source records attributed to Ching-Yu Yen.

8 recordsLinked to original sources

PubMed2006

Radiolocalized sentinel lymph node biopsy in squamous cell carcinoma of the oral cavity and analysis of various parameters.

BACKGROUND: Sentinel lymph node (SLN) biopsy seems to be a method that solves the problem of neck management with oral squamous cell carcinoma. Using blue dye methods for detection of neck SLNs from the surface of the operative field seems difficult; therefore, we used radiolocalization alone to detect and extract sentinel nodes. Aside from the various histological and clinical parameters examined in this procedure, we also determined whether they had any clinical significance in relation to the detection of SLNs during the operation. METHODS: Enrolled subjects had preoperative clinical N0 stage squamous cell carcinoma of the oral cavity and had received an unfiltered (99m)Tc sulfur colloid peritumoral injection. Localization of the SLNs was performed by using lymphoscintigraphy and a handheld gamma probe. RESULTS: In total, 28 oral squamous cell carcinoma patients were included in this prospective study. Sixty-four SLNs in 27 patients were identified by this method. The identification rate was 96.4%. No false-negative predictions of SLN were noted among any of the patients studied. The numbers of the SLNs found during the operation were larger in patients with positive findings than those with negative findings (P < .05 by the Mann-Whitney U-test). CONCLUSIONS: SLN radiolocalization provided an acceptable identification rate. The cases of positive findings for metastasis seemed to statistically have more SLNs than did those with negative findings, but more evidence is needed to prove this point. Therefore, SLN biopsies for extracting all possible high-risk nodes may be conducive for oral squamous cell carcinoma surgery.

Adult↗

PubMed2006

Outcome of treatment with total main tumor resection and supraomohyoid neck dissection in oral squamous cell carcinoma.

BACKGROUND/PURPOSE: Supraomohyoid neck dissection (SOHND) is commonly used to treat oral squamous cell carcinoma (OSCC) patients with clinical N0 or selected N1 status. The purpose of this study was to evaluate the clinical outcome of OSCC patients treated with SOHND. METHODS: This retrospective study reviewed the clinical outcome of 257 patients (247 men, 10 women) with N0, N1 and N2a OSCC treated with wide excision of the main tumor and SOHND between 1992 and 1999. All patients were followed up for at least 5 years. Survival distributions were analyzed using Kaplan-Meier curves. N status was compared using chi2 and log rank tests. RESULTS: The neck failure rate was 20% for clinically false negative cases, 6.1% for clinically true negative cases, 21.8% for clinically false positive cases, and 40% for clinically true positive cases. The 3- and 5-year overall neck disease-free survival rates were 79.8% and 77.6%, respectively. The 3- and 5-year neck disease-free survival rates were 86.7% and 84.2% for pathologic N0 cases, 56.9% and 56.9% for pathologic N1 cases, and 27.5% and 27.5% for pathologic N2 cases, respectively. Log rank test showed that the p value for difference in survival at 3-5 years was 0.064 for pathologic N0 vs. N1 cases, < 0.0001 for pathologic N0 vs. N2 cases, and 0.008 for pathologic N1 vs. N2 cases. CONCLUSION: This study showed that SOHND is effective for pathologic N0 OSCC, relatively effective for pathologic N1, and less effective for pathologic N2a. These findings also support that when SOHND is used to treat N2a OSCC, postoperative radiotherapy or radical neck dissection may be needed to improve the neck disease-free survival rate.

Adult↗

PubMed2005

Detection of Epstein-Barr virus infection and gene expression in human tumors by microarray analysis.

Epstein-Barr virus (EBV) genome-chips are employed to determine the EBV infection rate and to reveal the gene expression patterns of EBV in tumor biopsies. These chips are produced with 71 consecutive PCR-amplified EBV DNA fragments of 1-3 kbp covering the entire EBV genome. The specificity of the EBV-chips is determined by hybridizing the DNA on the chips with biotin-labeled cDNA probes reverse transcribed from the mRNA of P3HR1 cells, which were B-cell infected latently by EBV. Hybridization results revealed only the expression of EBNA1, EBNA2, EBER1 and EBER2 in these cells. On the other hand, EBV lytic genes are expressed after the cells are treated with 12-O-tetradecanoylphorbol-13-acetate and sodium butyrate to induce the EBV lytic cycle. Fourty-four tumor biopsies from different organs are assayed with these chips, which showed many defined and interesting EBV gene expression patterns. This study demonstrates that the EBV-chip is useful for screening infection with EBV in tumors, which may lead to insights into tumorigenesis associated with this virus.

B-Lymphocytes↗

PubMed2005

Areca quid chewing enhances the expression of salivary matrix metalloproteinase-9.

BACKGROUND AND PURPOSE: The effects of areca quid (AQ) consumption on salivary matrix metalloproteinases (MMPs) which may participate in tumor invasion and metastasis remains unclear. This study assessed the change in salivary MMP-9 protein levels 2 hours after 5-minute AQ chewing stimulation (AQCS) in non-AQ users and the expression profile of this proteinase in saliva and tumor specimens of oral squamous cell carcinoma (OSCC) patients with a history of AQ use. METHODS: MMP-9 transcript was analyzed by reverse transcription-polymerase chain reaction. MMP-9 protein level was measured by both Western blot and gelatin zymography. RESULTS: The protein level of salivary MMP-9 was 3.1- to 8.9-fold enhanced 2 h after AQCS in 3 healthy volunteers as revealed by Western blot and zymography. As a control, gum chewing did not significantly change salivary MMP-9 protein level. Expression of MMP-9 transcript was found in 25 of 28 OSCC specimens and significantly correlated with cervical lymph node metastasis (p = 0.037). All of the 8 tested OSCC tissue homogenate samples available and all 12 saliva samples from 12 oral tumor outpatients were positive for MMP-9 protein. CONCLUSIONS: Elevation of MMP-9 may be one of the net effects of AQCS in vivo, which may play a role in the pathogenesis of oral mucosal lesions. Furthermore, the association of MMP-9 expression with neck-lymph-node metastasis may imply a significant role of MMP-9 in the progression of OSCC among patients with a history of AQ use in Taiwan.

Areca↗

PubMed2005

Increased expression of matrix metalloproteinase-2 in oral cells after short-term stimulation and long-term usage of areca quid.

BACKGROUND AND PURPOSE: Arecoline, an areca quid (AQ) component, has been shown to inhibit the secretion and activity of matrix metalloproteinase-2 (MMP-2) in fibroblast cultures. This study assessed whether MMP-2 expression was inhibited in the saliva samples and tumor specimens of oral tumor patients with a long-term history of AQ consumption. The net effect of crude AQ extract (AQE) on MMP-2 expression by oral cells was also investigated. METHODS: Western blot analysis, zymography, and reverse transcriptase-polymerase chain reaction were used to detect MMP-2 protein and mRNA in saliva and tumor samples, as well as in the conditioned media (CM) of oral cell cultures. RESULTS: The level of MMP-2 protein was significantly higher in the saliva samples of 12 oral tumor patients who had a minimum 10-year AQ-consuming history than in those of 12 non-AQ-using healthy controls (p < 0.05). MMP-2 mRNA was expressed in 26 of 28 oral squamous cell carcinoma (OSCC) specimens. MMP-2 protein was also detectable in the tested OSCC homogenates. Short-term stimulation with 10% AQE increased the secretion of MMP-2 protein in the CM of oral epidermoid carcinoma cell Meng-1 (an OSCC cell line) and oral fibroblasts. CONCLUSIONS: MMP-2 expression is elevated rather than inhibited in most oral tumor patients with long-term AQ usage. Short-term AQE stimulation also increases the secretion of MMP-2 by oral epithelial cells and fibroblasts. Our results suggest that AQ consumption may promote oral tumor progression through the induction of MMP-2 secretion.

Areca↗

PubMed2004

Overexpression of Rac-1 small GTPase binding protein in oral squamous cell carcinoma.

PURPOSE: Oral squamous cell carcinoma (OSCC) is a fairly common malignancy in Taiwan and most countries of South Asia due to the popularity of areca quid use. In vitro studies have indicated that Rac proteins, a member of ras-related small GTPase protein family, can regulate cytoskeletal structures and activate signaling cascade and have the potential to transform cultured cells. However, Rac alteration during oral carcinogenesis in vivo has yet to be shown. The present study was conducted to investigate the importance of Rac-1 in oral tumorigenesis in vivo. PATIENTS AND METHODS: Expression level of Rac-1 protein and mRNA in OSCC together with noncancerous match tissue (NCMT) was explored using immunohistochemistry and reverse transcription-polymerase chain reaction analysis. RESULTS: The immunoreactivity of Rac-1 was shown in a significantly higher fraction of OSCC (74%) relative to the 48% in NCMT (P =.03). Eight of 14 (57%) available tissue pairs also showed overexpression of Rac-1 mRNA in OSCC than that in NCMT. The Rac-1 immunoreactivity did not differ significantly in accord with clinicopathologic parameters including areca quid use. However, 3 of 4 recurrent OSCC studied lacked the Rac-1 immunoreactivity. CONCLUSIONS: Our results presented novel findings: Rac-1 overexpression is a frequent occurrence in OSCC, highlighting the involvement of GTPase elements in the neoplastic growth of OSCC.

Carcinoma, Squamous Cell↗

PubMed2003

Areca nut extract treatment elicits the fibroblastoid morphological changes, actin re-organization and signaling activation in oral keratinocytes.

BACKGROUND: Areca (named as betel) is an important etiological factor linked with the high prevalence of oral squamous cell carcinoma (OSCC) in South-Asian countries. This in vitro study investigated the cellular changes and signaling activation in oral keratinocytes in response to areca nut extract (ANE) treatment. METHODS: Normal human oral keratinocyte (NHOK) and oral epidermoid carcinoma cell, Meng-1 (OECM-1) OSCC cell line were treated with variable dosages of ripen ANE. The morphological and cytoskeletal changes, as well as the activation of GTPase proteins and signaling kinases, were analyzed. RESULTS: Most NHOK cells in culture were polygonal, with only <5% cells exhibiting fibroblastoid morphology. However, 10 microg/ml ANE elicited fibroblastoid morphological change, genesis of lamellipodia, loss of subcortical actin, and stress-fiber formation in approximately 25% cultivated NHOK cells. Similar morphological changes were observed in nearly all OECM-1 cells following the ANE treatment. The activation of Rac and Rho GTPase, together with the prominent phosphorylation of a stress-activated kinases, particularly JNK1, was identified in treated OECM-1 cells. CONCLUSION: The novel evidences from the study that ANE impairs the actin organization and activates the signals in oral keratinocytes might bestow further insight into the impacts of ANE in oral pathogenesis.

Actins↗

PubMed2002

Genotype analysis using human hair shaft.

Analysis of genotypes for genetic predisposition of diseases has profound and widespread clinical application and has become a fundamental tool in the study of molecular epidemiology. In this study, we report a convenient and completely noninvasive approach to perform genotyping using terminal cephalic hair shaft. The average and median DNA amounts purified from the hair shaft are 112 +/- 180 (1 SD) pg/mg and 66 pg/mg of hair shaft, respectively. Using hybridization with molecular beacons that can reliably distinguish single nucleotide polymorphisms at different alleles, we are able to analyze the genotypes of APO-E and G-protein beta3 (GNB3) subunit C825T loci in DNA samples obtained from hair shaft in a high throughput format. The amount of DNA obtained from 20 mg of hair shaft is sufficient for multiple independent genotyping assays. These findings demonstrate that terminal hair shaft provides a convenient and reliable genomic DNA source for an analysis of genotypes.

DNA↗