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Biomedical subjects

Y E Park

Publications and source records attributed to Y E Park.

13 recordsLinked to original sources
PubMed2003

Association of maspin expression with the high histological grade and lymphocyte-rich stroma in early-stage breast cancer.

AIMS: Maspin is a recently described member of the serpin family or protease inhibitors that is known to be a tumour suppressor gene product. Loss of maspin expression has been found in most breast cancer cases and is correlated with cell motility and tumour invasiveness. However, its precise role in human breast cancer remains to be discovered. We aimed to evaluate the role of maspin in early-stage breast cancer. METHODS AND RESULTS: We analysed the expression of maspin in 192 stage I and II primary breast cancers by immunohistochemistry. Of these cases, 34.4% showed maspin expression. Maspin expression was more frequently found in invasive ductal carcinoma (36.4%) than in invasive lobular carcinoma (7.1%). High maspin expression was demonstrated in breast cancers showing high histological grade or lymphocyte-rich stroma (P < 0.05). Maspin expression was not associated with overall and disease-free survival rate of breast cancer. CONCLUSIONS: The results indicate that different biological mechanisms may be responsible for maspin expression in histologically distinct types of breast cancer. Our survey suggests that maspin expression in breast cancer might have a compensatory role rather than prognostic one.

Adenocarcinoma↗
PubMed2003

Expression of HMGI(Y) associated with malignant phenotype of human gastric tissue.

AIMS: We evaluated the association between HMGI(Y) expression and the detection of malignant cells by simple reverse transcriptase-polymerase chain reaction (RT-PCR) and correlated the level of HMGI(Y) expression and the clinicopathological data in gastric cancer. METHODS AND RESULTS: We analysed HMGI(Y) expression in 62 gastric cancer tissues and 28 normal gastric tissues by RT-PCR and immunohistochemical study. HMGI(Y) expression evidenced by RT-PCR was observed in 42 (67.7%) of 62 gastric cancer samples, whereas eight (28.6%) of 28 normal gastric tissues were positive (P = 0.001). In immunohistochemical staining for HMGI(Y), 48 (77.4%) of 62 gastric cancers were positive for HMGI(Y), whereas four (6.5%) of 62 normal gastric mucosae around the tumour were weakly positive, particularly in cells of some hyperplastic glands (P < 0.001). There was no significant correlation between the levels of HMGI(Y) expression and stage, tumour size, histological grade, invasion depth, or lymph node metastasis. CONCLUSIONS: Our results suggest that HMGI(Y) expression could be associated with malignant phenotype in human gastric tissue, and that HMGI(Y) may contribute to gastric tumorigenesis.

Adenocarcinoma↗
PubMed2000

Mutation and expression of the p27KIP1 and p57KIP2 genes in human gastric cancer.

Cyclin-dependent kinase inhibitors (CDKI) are negative regulators of cell cycle progression by binding the cyclin-CDK complex and inhibiting the CDK activity. Genetic alteration in the CDKI genes has been implicated for carcinogenesis. To test the genetic alteration in the p27 and p57 genes, KIP family CDKI genes, 30 gastric tumor-normal pairs and 8 gastric cancer cell lines were analyzed for mutations by polymerase chain reaction-single strand conformational polymorphism (PCR-SSCP). No mutation was detected in these genes although length polymorphisms in the proline-alanine repeat of the p57 gene were detected. When the p27 and p57 mRNAs were analyzed in gastric cancer cell lines by RT-PCR, the p27 mRNA was expressed considerably high in tumor cells but expression of the p57 mRNA was much low in gastric cancer cell lines compared to that of normal cells. The result suggests that inactivation of gene expression rather than mutations in the p57 gene accounts possibly for the involvement of this gene in tumorigenesis of gastric cancer. However, expression of the p27 gene seems to be essential for cell survival.

Cell Cycle Proteins↗
PubMed2000

Reduced expression of the cell-cycle inhibitor p27Kip1 is associated with progression and lymph node metastasis of gastric carcinoma.

AIMS: p27Kip1 (p27), a cyclin-dependent kinase inhibitor, plays an important role as inhibiting the progression of the cell cycle. Decreased expression of p27 is associated with high histological grade and aggressiveness of several human tumours. We aimed to evaluate the role of p27 in the progression and metastasis of gastric carcinoma. METHODS AND RESULTS: We analysed the expression of p27 in 67 primary gastric carcinomas and 31 lymph node metastases by immunohistochemistry. Reduced expression of p27 was found more frequently in advanced gastric cancer (40.9%) than in early gastric cancer (15.6%) (P < 0.001). Decreased p27 expression correlated with large tumour size, high histological grade, lymphatic invasion, advanced stage, deep invasion, lymph node metastasis and recurrence. The expression of p27 showed an inverse correlation with the Ki67 labelling index. There was a significant reduction of p27 expression in metastatic tumour cells in lymph nodes (mean positive cells: 3. 7%) when compared to the corresponding primary gastric carcinomas (mean positive cells: 8.1%) (P = 0.008). CONCLUSIONS: Alterations of p27 expression may play an important role in the progression and metastasis to lymph node of tumour cells in human gastric carcinoma.

Biomarkers, Tumor↗
PubMed2000

Caspase-3/CPP32 immunoreactivity and its correlation with frequency of apoptotic bodies in human prostatic carcinomas and benign nodular hyperplasias.

AIMS: Apoptosis is mediated by apoptosis-specific genes, certain oncogenes and tumour suppressor genes. Caspase-3, a group of cystein proteases, is involved in the induction of apoptosis and has been considered to correlate with apoptosis. The aim of this study was to determine whether caspase-3 is expressed in prostatic carcinoma and benign prostatic hyperplasia, and correlated with the apoptosis. METHODS AND RESULTS: We studied the apoptotic index and caspase-3 immunoreactivity in 40 cases of benign nodular hyperplasia (BPH) and 40 cases of prostate carcinoma (PCA) by in-situ labelling and immunohistochemistry. The mean number of apoptotic bodies in cases with BPH was not significantly different from cases with PCA I (Gleason score 2-4), but samples from patients with PCA II (Gleason score 5-7) and PCA III (Gleason score 8-10) showed a significantly higher apoptotic number than cases with BPH. Positive staining for caspase-3 was seen in 42.5% (17/40) of the BPH, and 27.5% (11/40) of the PCA: PCA I was 41.7% (5/12), PCA II 14.3% (2/14) and PCA III was 28.6% (4/14). CONCLUSIONS: Based on our results, the number of apoptotic bodies was not correlated with the caspase-3 expression and there was no relationship between caspase-3 expression and Gleason score. However, the number of apoptotic bodies was significantly higher in cases with intermediate (Gleason score 5-7) and high-grade (Gleason score 8-10) PCAs than cases with BPH and low-grade PCAs (Gleason score 2-4).

Adenocarcinoma↗
PubMed1999

Expression of the HMGI(Y) gene in human colorectal cancer.

Expression of HMGI(Y), a nucleoprotein that binds to A/T rich sequences in the minor groove of the DNA helix, is observable in neoplastically transformed cells but not in normal cells. We have analyzed HMGI(Y) expression in colorectal cancer and evaluated its clinicopathologic significance. HMGI(Y) mRNA was measured by CRT-PCR (competitive reverse transcription-polymerase chain reaction). Immunohistochemical staining for HMGI(Y), p53 and Ki-67 was performed in the same colon cancer tissues, and the results in colorectal tissues were similar to those of RT-PCR. HMGI(Y) expression evidenced by RT-PCR was observed in 63 of 64 (98.4%) colorectal cancer samples, and 2 of 5 (40%) adenomatous polyps, whereas 21 normal colon samples were negative (p<0.001). High HMGI(Y) expression using CRT-PCR was found in colon cancers with a high Ki-67 labeling index (p<0.001). There was no significant correlation between the levels of HMGI(Y) expression and stage, tumor size, lymph node metastasis, histologic grade and immunohistochemical status of p53. Our results indicate that the HMGI(Y) expression may occur at an early stage of carcinogenesis and correlate with cell proliferation. Int. J. Cancer (Pred. Oncol.), 84:376-380, 1999.

Adenomatous Polyposis Coli↗
PubMed1999

Apoptosis induced by propolis in human hepatocellular carcinoma cell line.

Propolis has been reported to exhibit a wide spectrum of activities including antibiotic, antiviral, anti-inflammatory, immunostimulatory and tumor carcinostatic properties. We showed propolis induced apoptosis in a human hepatoma cell line (SNU449) by FITC-Annexin V/PI staining. We also compared the apoptosis inducing effect between Korean and Commercial (Sigma # p-1010) propolis. There was no difference on apoptosis between them.

Annexin A5↗
PubMed1998

p21 expression and mutation in gastric carcinoma: analysis by immunohistochemistry and PCR-SSCP.

p21 protein has been reported to be a critical downstream effector of p53 and a potent inhibitor of cyclin-dependent kinases. Thus, the p21 gene is thought to play a central role in tumor suppression. In this study we investigated p21 protein expression and mutation in gastric adenocarcinoma. A total of 76 primary gastric carcinoma specimens were immunohistochemically stained for p21 protein expression and evaluated the correlations between p21 expression and clinicopathologic features. In a proportion of them (20 cases), we also analyzed the possible presence of p21 gene mutations using PCR-SSCP method. Fourty seven out of 76 cases (61.8%) were p21-negative, and the remaining twenty nine cases (38.2%) were p21 -positive on immunostains. There was a correlation between the expression of p21, and the depth of tumor invasion and lymph node metastasis (p<0.05). No mutation of the p21 gene was detected in all of 20 tumor tissues. These results suggest that the status of p21 expression may have prognostic value in gastric adenocarcinoma.

Adenocarcinoma↗
PubMed1997

Transforming growth factor beta 1 expression in gastric carcinoma.

Many types of human malignant tumor have been reported to amplify transforming growth factor-beta 1 (TGF-beta 1) gene and overexpress its protein. However, little work has been done about the content of TGF-beta 1 protein in tissue and blood of patients with malignant tumors. TGF-beta 1 protein of tissue (n = 29) and serum TGF-beta 1 levels in patients with gastric carcinoma (n = 62) were compared with those in normal subjects (n = 10) using a TGF-beta 1 enzyme-linked immunosorbent assay. Also, expression of TGF-beta 1 mRNA (n = 20) and immunohistochemical distribution of the protein (n = 70) in gastric carcinoma tissues were studied. The immunohistochemical expression of TGF-beta 1 protein was significantly correlated with the tissue TGF-beta 1 content (r = 0.45 : p < 0.05). The content of TGF-beta 1 was 311 +/- 212 ng/g wet carcinoma tissue. TGF-beta 1 mRNA was expressed in gastric carcinoma cells. However, unexpectedly serum TGF-beta 1 levels in patients with gastric carcinoma were lower (97.1 +/- 29.4 ng/ml) than those in normal subjects (140.3 +/- 85.7 ng/ml, P < 0.05). Our results support that the tumor cells directly produce TGF-beta 1 and that semiquantitative immunohistochemical staining method for TGF-beta 1 protein is a validative method for TGF-beta 1 protein quantitation.

Adult↗
PubMed1997

Relationship of transforming growth factor beta 1 to angiogenesis in gastric carcinoma.

Transforming growth factor-beta (TGF-beta) comprises a group of multifunctional regulatory proteins, whose effects include angiogenesis. The expression of TGF-beta 1 in gastric carcinomas (70 cases) has been determined and related to pathological features and microvessel count by immunohistochemical staining for TGF-beta 1 and Factor VIII related antigen. Prominent reactivity for TGF-beta 1 was associated with the depth of invasion (r = 0.2; p < 0.05) and increased microvessel count (r = 0.5; p < 0.05). Also, the microvessel count had a significant correlation with invasiveness (r = 0.34; p < 0.05) and lymph node metastasis (r = 0.28; p < 0.05). These findings indicate that TGF-beta 1 may have a role in tumor invasion and angiogenesis.

Adult↗
PubMed1996

Expression of bFGF and VEGF in brain astrocytoma.

Neovascularization is an important factor in the prognosis of brain tumor and many angiogenetic factors have been evaluated for prognostic significance. Among them, basic fibroblast growth factor (bFGF) and vascular endothelial growth factor (VEGF) are known as potent angiogentic factors and mitogens. We evaluated seven cases of grade II brain astrocytoma. Four, group A, was diagnosed as anaplastic progression at their second operation, and three, group B, did not. Using monoclonal antibodies to bFGF and VEGF in paraffin embedded tissue from first operation, their immunoreactivity and differences between two groups were examined. The growth fractions of these tumor were also measured by Ki-67 monoclonal antibodies (MIB1). Immunostaining for bFGF in tumor cells were observed in both nuclei and cytoplasm, and for VEGF, mainly observed in the cytoplasm. Mean cell count number +/- standard deviation per high power field in each were as follows: 1) for bFGF, 20.08 +/- 6.38 in group A and 0.87 +/- 0.90 in group B (P < 0.01), 2) for VEGF, 43.75 +/- 17.09 in group A, and 0.8 +/- 1.06 in group B (P < 0.05) and 3) for the proliferation index with Ki-67 antibodies, 3.20 +/- 0.81 in group A and 0.77 +/- 1.03 in group B (P < 0.05). This data supports the assertion that angiogenetic factor such as bFGF and VEGF may contribute to progressive change of astrocytoma by tumor angiogenesis.

Adolescent↗
PubMed1991

A case of retroperitoneal teratoma with nephroblastoma.

We present a case of retroperitoneal teratoma in a 4-year-old girl in which a Wilms' tumor-like element was predominant, unlike the usual pattern of the immature or malignant teratoma. Mature elements were composed of adipose tissue, neural plexus and ganglia, cartilage, smooth and skeletal muscles, and glandular epithelium of the respiratory and gastrointestinal types. Three months after complete excision of the mass, a recurrent tumor developed. It consisted of only nephroblastomatous elements without teratomatous components. Theories for the histogenesis of this rare tumor are discussed.

Child, Preschool↗