Biomedical subjects

Kyong Sik Lee

Publications and source records attributed to Kyong Sik Lee.

7 recordsLinked to original sources

PubMed2006

The changes of estrogen receptor-beta variants expression in breast carcinogenesis: Decrease of estrogen receptor-beta2 expression is the key event in breast cancer development.

BACKGROUND AND OBJECTIVES: Although more than five variant forms of estrogen receptor-beta (ERbeta) have been identified, their role has not been identified. This study was carried out to investigate the changes of ERbeta variants in breast cancer development. METHODS: Using reverse transcription polymerase chain reaction (RT-PCR) and triple primer PCR (TP-PCR), the expression levels of ERbeta variants mRNA were measured in 66 paired normal and cancer tissues. The relative expression level of ERbeta variants were compared between normal and cancer tissues, and also compared according to various clinicopathological parameters. RESULTS: Among ERbeta variants, ERbeta2 and ERbeta5 consist of the major proportion of ERbeta expression both in normal and cancer tissues. The ERbeta and ERbeta2 expression levels decreased significantly in the cancers compared with corresponding normal tissues, particularly in ERalpha-expressing cancers. However, ERbeta5 expression level increased significantly in the cancers, especially in those of postmenopausal patients. The relative increase of ERbeta5 expression in cancer tissues was associated with favorable differentiation. CONCLUSIONS: Decrease of ERbeta2 is thought to be the key reason for the decrease in ERbeta expression in cancer tissues, and it is particularly associated with the development of ERalpha-expressing breast cancer.

Breast↗

PubMed2006

Comparison of stage-specific outcome of breast cancer based on 5th and 6th AJCC staging system.

BACKGROUND AND OBJECTIVES: To investigate the appropriateness of the new staging system (AJCC 6th edition) for breast carcinoma. METHODS: We reviewed the clinicopathologic data of 1,768 breast cancer patients, and their disease stages were re-categorized by the new system. The overall survival (OS) and distant relapse free survival (DRFS) rates were compared between those patients whose stages by the old system (AJCC 5th edition) remained the same (the remainders) and those patients whose stages moved up (the upstaged cases) as well as between the subgroups in the new system. RESULTS: The 10-year DRFS rates of the upstaged cases in each stage were poorer than those of the remainders, and statistical significance was demonstrated for stage IIB and stage IIIA. The 10-year OS rates were also poorer in the upstaged cases, and statistical significance was demonstrated for stage IIIA. Subgroup analysis within the new system between the node-negative versus node-positive subgroups in stages IIA and IIB showed a significant OS difference. The DRFS difference was also shown between the subgroups in stage IIA. CONCLUSIONS: The new staging system seems to more accurately reflect disease outcome, however, a re-evaluation might be required to reflect the impact of nodal involvement upon the new staging system.

Breast Neoplasms↗

PubMed2003

Expression of estrogen receptor-beta in normal mammary and tumor tissues: is it protective in breast carcinogenesis?

Using messenger RNA (mRNA) in situ hybridization, we investigated estrogen receptor-beta (ERbeta) mRNA levels in normal mammary, benign breast tumor (BBT), breast cancer (BC), and metastatic lymph node tissues to verify the role of ERbeta in BC development and progression. ERbeta expression was significantly decreased in BC and metastatic lymph node tissues compared with normal mammary and BBT tissues (p < 0.01). The intensity and extent of ERbeta mRNA signals were also significantly lower in BC and metastatic lymph node tissues than in the normal mammary and BBT tissues (p < 0.01). An inverse relationship was found between ERbeta mRNA level and both histologic grade (p = 0.091) and progesterone receptor expression (p = 0.052) with marginal significance, but no significant association was noted between ERbeta expression in cancer tissues and the other clinico-pathologic data. The 3-year distant relapse-free survival probability was found to be independent of ERbeta expression. Collectively, ERbeta mRNA decreases in the process of BC development, but seems to be associated with poor differentiation.

Biomarkers, Tumor↗

PubMed2003

Overexpression of cyclooxygenase-2 is associated with breast carcinoma and its poor prognostic factors.

Cyclooxygenase is the rate-limiting enzyme that catalyzes the conversion of arachidonic acid to prostaglandins. The inducible form, cyclooxygenase-2, is known to be overexpressed in various human cancers including the colon, stomach, and urinary bladder. In this study, we evaluated the overexpression of cyclooxygenase-2 in 64 cases of breast cancer and correlated the results with clinicopathologic parameters. Immunohistochemical staining for cyclooxygenase-2 demonstrated positivity of the tumor cells in 46 of 64 cases (72%). Cyclooxygenase-2 overexpression was significantly correlated with larger tumor size and advanced clinical stage. Cyclooxygenase-2 overexpression tended to be more frequently observed in cases with presence of lymph node metastasis and in cases without expression of estrogen and progesterone; however, there was no significant correlation statistically. Nuclear and histologic grade were not well correlated with cyclooxygenase-2 overexpression. When ductal carcinoma in situ was considered separately, 32 of 42 cases (76%) were positive for cyclooxygenase-2. We conclude that cyclooxygenase-2 is up-regulated in a high proportion of breast cancers. The overexpression of cyclooxygenase-2 was associated with larger tumor size and advanced clinical stage, although lymph node status, estrogen and progesterone expression, and nuclear and histologic grade were not significantly correlated. Therefore, cyclooxygenase-2 overexpression may be a feature of the aggressive phenotype and may be useful as a prognostic indicator in breast cancer.

Breast Neoplasms↗

PubMed2003

Anti-HER2/neu peptide producing vector system for biologic therapy - is it possible to mass-produce the peptide?

A humanized monoclonal antibody against HER2 has been using in a clinical setting and has been shown to possess therapeutic properties. A mimetic peptide against HER2 was also reported to bind to the HER2 receptor with some therapeutic potential. Based on a previous report and the sequence of Herceptin, we designed oligonucleotides of anti-HER2 mimetic peptides, named V2 and V3 peptides, in order to develop a peptide- producing vector system for biologic therapy against HER2- overexpressing cancers. We also adopted the sequence of a previously reported mimetic peptide, V1 (Park BW et al. Nat. Biotechnol, 2000, 18:194-198), as a reference peptide. We examined the effects of the V2 and V3 peptides against the HER2-overexpressing cell lines, SK-BR-3 and T6-17. Transient transfection of the construct expressing V1 and V2 inhibited cell proliferation in HER2-overexpressing cell lines by 20 - 30%, but had no effect on the HER2-negative NIH3T3 cells. The proliferation inhibition shown by V2 was slightly better than that shown by V1. Recombinant peptides V2 and V3 were produced on a large scale in an E. coli system, and the V2 peptide showed anti-HER2-specific tumor cell proliferation inhibition of 10% to 30%. Current results suggest that anti-HER2 mimetic peptides, overexpressed by a constitutive promoter or produced in an E. coli system, could specifically inhibit the proliferation of HER2-expressing cancer cells. Further efforts to augment the biologic specificity and efficacy and to develop new technologies for the purification of the peptide from the E coli system are needed.

Amino Acid Sequence↗

PubMed2002

Impact of patient age on the outcome of primary breast carcinoma.

BACKGROUND AND OBJECTIVES: The poorer outcome amongst younger breast cancer patients continues to be an issue of debate. In order to clarify the prognostic value of patient age, we retrospectively analyzed the data of 1098 breast cancer patients. METHODS: Patients were divided into two groups based on the age 35 (Group I, women aged 35 or younger, and Group II, women aged over 35). Clinico-pathological parameters, 10-year loco-regional recurrence-free (10LRRFS), distant relapse-free (10DRFS), and overall (10OS) survival estimates were determined. RESULTS: Among the 1098 patients, approximately 16.7% (183) were allocated to Group I and the other 83.3% (915) to Group II. There were no significant differences between the two groups in terms of histopathologic features or mean follow-up. Group I had a poorer 10LRRFS of 86.8% (P = 0.036), 10DRFS of 57.7% (P < 0.0001), and 10OS of 68.3% (P = 0.0001), compared with 93.9, 76.2, and 81.4% for Group II, respectively. Group I also showed a poorer 10DRFS when matched for stage and lymph node status as well. With lymph node status and tumor size, a patient age of younger than 35 was determined to be an independent prognostic factor by multivariate analysis. CONCLUSIONS: These results indicate that patient age (younger than 35) shows an independent prognostic value and that survival differences by age may reflect differences in the tumor biology.

Adult↗

PubMedDate not supplied

The role of sonography in patients with breast cancer presenting as an axillary mass.

OBJECTIVE: To compare sonography and mammography in terms of their diagnostic value in breast cancer cases which initially presented as an axillary mass without a palpable mass or other clinical symptoms. MATERIALS AND METHODS: Seven patients with enlarged axillary lymph nodes who first presented with no evidence of palpable breast lesions and who underwent both mammography and sonography were enrolled in this study. In six of the seven, the presence of metastatic adenocarcinoma was confirmed preoperatively by axillary needle aspiration biopsy; in four, subsequent sonographically-guided breast core biopsy performed after careful examination of the primary site indicated that primary breast cancer was present. In each case, the radiologic findings were evaluated by both breast sonography and mammography. RESULTS: Breast lesions were detected mammographically in four of seven cases (57%); in three of the four, the lesion presented as a mass, and in one as microcalcification. In three of these four detected cases, fatty or scattered fibroglandular breast parenchyma was present; in one, the parenchyma was dense. In the three cases in which lesions were not detected, mammography revealed the presence of heterogeneously dense parenchyma. Breast sonography showed that lesions were present in six of seven cases (86%); in the remaining patient, malignant microcalcification was detected at mammography. Final pathologic examination indicated that all breast lesions except one, which was a ductal carcinoma in situ, with microinvasion, were infiltrating ductal carcinomas whose size ranged from microscopic to greater than 3 cm. At the time of this study, all seven patients were alive and well, having been disease free for up to 61 months after surgery. CONCLUSION: In women with a palpable axillary mass confirmed as metastatic adenocarcinoma, breast sonography may be a valuable adjunct to mammography.

Adenocarcinoma↗