Biomedical subjects

Je-Ho Lee

Publications and source records attributed to Je-Ho Lee.

At least 19 recordsLinked to original sources

PubMed2007

GADD153 mediates celecoxib-induced apoptosis in cervical cancer cells.

Celecoxib, a selective cyclooxygenase 2 inhibitor, is known to have anti-inflammatory activity and to induce apoptosis in various types of cancer cells. Here, we examined the molecular mechanism of celecoxib-induced apoptosis in cervical cancer cell lines (HeLa, CaSki and C33A). Screening of a microarray cDNA-chip containing 225 different genes revealed that growth arrest and DNA damage inducible gene (GADD153), a transcription factor involved in apoptosis, showed the strongest differential expression following celecoxib treatment in all three cervical cancer cell lines. Notably, siRNA-induced silencing of GADD153 suppressed celecoxib-induced apoptosis in all the three cell lines, and exogenous expression of GADD153 triggered apoptosis in cervical cancer cells in the absence of other apoptotic stimuli. A luciferase reporter gene assay and mRNA stability tests revealed that expression of GADD153 was regulated at both the transcriptional and post-transcriptional levels following celecoxib treatment. The region between -649 and -249, containing an intact C/EBP-ATF binding site, was required for the basal activity and celecoxib-induced stimulation of GADD153 promoter activity. Also, mRNA stability test showed that celecoxib prolonged the half-life of GADD153 mRNA. In terms of signaling pathway, addition of the NF-kappaB inhibitor, N-tosyl-L phenylalanyl-chloromethyl ketone (TPCK), had no effect on GADD153 expression levels. Celecoxib treatment induced Bak expression, whereas cell treated with siGADD153 or TPCK showed lower levels of celecoxib-induced Bak up-regulation. These novel findings collectively suggest that GADD153 may play a key role in celecoxib-induced apoptosis in cervical cancer cells by regulating the expression of proapoptotic proteins such as Bak.

Apoptosis↗

PubMed2006

Phase II study of neoadjuvant chemotherapy with mitomycin-c, vincristine and cisplatin (MVC) in patients with stages IB2-IIB cervical carcinoma.

OBJECTIVE: The efficacy and toxicity of neoadjuvant chemotherapy (NAC) with mitomycin-C, vincristine and cisplatin (MVC) were assessed in bulky cervical carcinoma patients. METHODS: Forty-six patients with stage IB2 to IIB cervical cancer were treated with intravenous combination of mitomycin-C 10 mg/m(2), vincristine 1 mg/m(2) and cisplatin 75 mg/m(2) every 3 weeks. After three cycles of NAC, the patients either underwent surgery or radiation therapy, depending on their suitability for radical hysterectomy. RESULTS: All 46 patients enrolled in this study were suitable for surgery after NAC. Twenty (44%) patients had risk factors after surgery and received postoperative radiation. Toxic nonhematologic reactions consisted primarily of grades 1-2 nausea and vomiting (87%) and the most common hematologic toxicity was anemia (60%). Clinical responses occurred in 83% (38/46) of patients, including 24% (11/46) with a complete response (CR) and 13% (6/46) with a pathologically determined complete response. For a median follow up period of 28 months, the 3-year disease-free and overall survival rates were 74% and 80%, respectively. Pathologically confirmed lymph node metastasis or parametrial involvement and an initial tumor size > or =4 cm were associated with shorter disease-free survival (P=0.040, P=0.000, P=0.025, respectively). CONCLUSION: Intravenous administration of MVC as a NAC seems to be well tolerated and beneficial in patients with stage IB2 to IIB cervical cancer.

Adult↗

PubMed2006

Alternative splicing variants of IRF-1 lacking exons 7, 8, and 9 in cervical cancer.

The two previously identified major splice variants of interferon regulatory factor 1 (IRF-1) do not appear to affect IRF-1-mediated gene activation. We searched for additional splice variants and examined their effect on wild-type IRF-1. RT-PCR experiments using normal and malignant human cervical tissue samples revealed five variants lacking some combination of exons 7, 8, and 9; their expression levels were higher in the malignant samples. These variants had predicted deletions of the functional domain or truncated protein isoforms, had different transcriptional activities, and attenuated transcriptional activity of IRF-1. Unlike the cell cycle-dependent IRF-1 transcript, the splice variant mRNA levels remained consistent throughout the cell cycle. The variant proteins were more stable than the IRF-1 protein, which may explain the strong inhibition of IRF-1 transcription in the presence of relatively small quantities of the alternative transcripts. In conclusion, alternative splicing in exons 7, 8, and 9 is an important mechanism for negatively regulating IRF-1 in cervical cancer.

Alternative Splicing↗

PubMed2006

A novel cervical cancer suppressor 3 (CCS-3) interacts with the BTB domain of PLZF and inhibits the cell growth by inducing apoptosis.

Promyelocytic leukemia zinc finger protein (PLZF) is a sequence-specific, DNA binding, transcriptional repressor differentially expressed during embryogenesis and in adult tissues. PLZF is known to be a negative regulator of cell cycle progression. We used PLZF as bait in a yeast two-hybrid screen with a cDNA library from the human ovary tissue. A novel cervical cancer suppressor 3 (CCS-3) was identified as a PLZF interacting partner. Further characterization revealed the BTB domain as an interacting domain of PLZF. Interaction of CCS-3 with PLZF in mammalian cells was also confirmed by co-immunoprecipitation and in vitro binding assays. It was found that, although CCS-3 shares similar homology with eEF1A, the study determined CCS-3 to be an isoform. CCS-3 was observed to be downregulated in human cervical cell lines as well as in cervical tumors when compared to those from normal tissues. Overexpression of CCS-3 in human cervical cell lines inhibits cell growth by inducing apoptosis and suppressing human cyclin A2 promoter activity. These combined results suggest that the potential tumor suppressor activity of CCS-3 may be mediated by its interaction with PLZF.

Apoptosis↗

PubMed2006

Squamous cell carcinoma with sarcomatoid features of the vulva: a case report and review of literature.

BACKGROUND: A squamous cell carcinoma with sarcomatoid features of the vulva is an extremely rare malignancy of the female genital tract. This type of tumor is known to grow rapidly and associated with poorer clinical outcomes than those of squamous cell carcinoma of the vulva. CASES: A 43-year-old woman presented to our institute with a 4-month history of an aggravated vulvar mass. A radical local excision, bilateral inguinal lymph node dissection and laparoscopic assisted vaginal hysterectomy were performed. The FIGO stage of the vulvar cancer was stage II (T(2)N(0)M(0)) and the pathologic finding was consistent with a poorly differentiated squamous cell carcinoma with extensive sarcomatoid features. No further treatment was given and there was no clinical evidence of recurrence during the 2 years of follow-up. CONCLUSION: A squamous cell carcinoma with sarcomatoid features of the vulva is a tumor with aggressive biological behavior. To date, there have been only 15 cases of this disease reported in the literature. So, a collection and close study of these cases would be extremely useful in singling out and identifying the best treatment possible for this type of tumor.

Adult↗

PubMed2006

High expression of tissue inhibitor of metalloproteinase-2 in serous ovarian carcinomas and the role of this expression in ovarian tumorigenesis.

Tissue inhibitors of metalloproteinases (TIMPs) play key roles in maintaining homeostasis of the extracellular matrix by controlling matrix metalloproteinases (MMPs). In addition to their role in regulating MMPs, TIMPs have also been shown to have pluripotential effects on cell growth, apoptosis, and differentiation. The aim of this study was to evaluate TIMP-2 level in serous ovarian tumor tissues and to understand further the role of TIMP-2 protein in ovarian tumorigenesis. The expression of TIMP-2 was assessed by immunohistochemistry in a total of 57 ovarian specimens, including 5 normal ovaries, 12 benign serous cystadenomas, 20 serous borderline tumors, and 20 serous carcinomas. In addition, we transfected a TIMP-2 plasmid into the gynecologic cancer cell lines SKOV-3, 2774, and HeLa and then assayed cell growth, apoptosis, and MMP-2 activation. We found that TIMP-2 immunostaining was significantly more frequent in serous carcinomas, mainly in tumor epithelium, compared with cells of the other tissues studied. Tissue inhibitor of metalloproteinase-2 overexpression in ovarian cancer cells did not mediate proapoptosis, inhibited cisplatin-induced apoptosis, and induced MMP-2 expression. These findings suggest that TIMP-2 may function to favor tumor growth in serous ovarian tumorigenesis. Additional research is now needed to elucidate further the role of TIMP-2 in the biologic behavior of ovarian serous tumors.

Adult↗

PubMed2006

GADD153 mediates celecoxib-induced apoptosis in cervical cancer cells.

Celecoxib, a selective cyclooxygenase-2 inhibitor, is known to possess anti-inflammatory activity and also induces apoptosis in various types of cancer cells. Here, we examined the molecular mechanism of celecoxib-induced apoptosis in cervical cancer cell lines (HeLa, CaSki and C33A). Screening of a cDNA microarray chip containing 225 different genes revealed that GADD153 (growth arrest and DNA damage inducible gene), a transcription factor involved in apoptosis, showed the strongest differential expression following celecoxib treatment in all three cervical cancer cell lines. Notably, siRNA-induced silencing of GADD153 suppressed celecoxib-induced apoptosis in all three cell lines, and exogenous expression of GADD153 triggered apoptosis in cervical cancer cells in the absence of other apoptotic stimuli. A luciferase reporter gene assay and mRNA stability tests revealed that the expression of GADD153 was regulated at both the transcriptional and post-transcriptional levels following celecoxib treatment. The region between -649 and -249, containing an intact C/EBP-ATF binding site, is required for celecoxib-induced stimulation of GADD153 promoter activity. In terms of signaling pathway, addition of the NF-kappaB inhibitor, N-tosyl-L-phenylalanyl-chloromethyl ketone, had no effect on GADD153 expression levels. Celecoxib treatment induced Bak expression, whereas cell transfected with siGADD153 showed lower levels of celecoxib-induced Bak upregulation. These novel findings collectively suggest that GADD153 may play a key role in celecoxib-induced apoptosis in cervical cancer cells by regulating the expression of proapoptotic proteins such as Bak.

Apoptosis↗

PubMed2006

Expression of CD44 adhesion molecules on human placentae.

OBJECTIVE: This study was performed to characterize CD44 expression in human placentae. STUDY DESIGN: We conducted reverse transcriptase polymerase chain reaction (RT-PCR) analyses of CD44H (hematopoietic form, also called CD44s) and CD44R1 (epithelial form) in 14 normal term placentae, and immunohistochemical analysis of CD44H and CD44v6 in 31 placentae (25 term and 6 first-trimester). RESULTS: All 14 term placentae expressed CD44H (double bands) suggesting expression of alternative isoforms on the placentae. CD44R1 was expressed on 3 of 14 (21.4%) term placentae. Immunohistochemical analysis revealed expression of CD44H in all the placentae examined. However, positive staining for CD44v6 was observed in 3 of 6 (50%) first-trimester and only 6 of 25 (24%) term placentae showing decreased expression on term placentae. Positive staining for CD44v6 was observed on the trophoblast surface of immature villi especially in the sub-chorionic area where hypoxic conditions prevail. CONCLUSION: These results suggest that CD44 splicing variants might play a role in the invasion of trophoblast into maternal tissue in early pregnancy.

Alternative Splicing↗

PubMed2006

Preliminary results of neoadjuvant chemotherapy with paclitaxel and cisplatin in patients with advanced epithelial ovarian cancer who are inadequate for optimum primary surgery.

AIM: This study was performed to evaluate the efficacy of neoadjuvant chemotherapy (NAC) with paclitaxel and cisplatin in patients with advanced epithelial ovarian cancer who were inadequate for primary optimal surgery. METHODS: Patients with histologically confirmed epithelial ovarian cancer at International Federation of Gynecology and Obstetrics stages IIIc/IV that was unresectable according to computed tomography findings were eligible for this study. Three cycles of paclitaxel plus cisplatin NAC were administered and the response was evaluated. Patients were then selected for interval debulking surgery or three cycles of additional chemotherapy with the same regimen according to the resectability and response. Interval debulking surgery followed by second-line chemotherapy was applied to patients with no response to NAC. During the same period, patients who did not agree to the protocol were treated by the conventional method of tumor debulking surgery followed by adjuvant chemotherapy, and served as the control group. A comparison of both groups of patients was carried out. RESULTS: A total of 40 patients were involved in the study. All patients were evaluable. Eighteen patients underwent NAC and 22 patients were treated by conventional therapy. Optimal debulking was possible in 14 patients (77.8%) in the NAC group and in 10 patients (45.5%) in the conventional therapy group (P = 0.04). The mean estimated blood loss was 620 cc (range: 300-1500 cc) in the NAC group and 1061 cc (range: 300-3500 cc) in the conventional therapy group (P = 0.04). However, no significant differences were found in the disease-free and overall survival rates between the two groups (P = 0.48 and P = 0.61, respectively). CONCLUSION: NAC provided a higher rate of optimum cytoreduction and equivalent survival with less invasive surgery and reduced morbidity compared with conventional therapy in patients with advanced epithelial ovarian cancer inadequate for primary optimum surgery. Therefore, NAC may be a valuable alternative treatment for these patients.

Adult↗

PubMed2006

Germline mutations of BRCA1 in two Korean hereditary breast/ovarian cancer families.

Testing for cancer susceptibility gene, in particular mutations in the BRCA1 gene in association with hereditary breast/ovarian cancer has been extensively studied. We investigated germline mutations in the BRCA1 gene from two Korean hereditary breast/ovarian cancer families using direct DNA sequencing. Blood samples of the thirteen family members were studied. We found three missense mutations; 3232 Aright curved arrow G, 2731 Cright curved arrow T, 3667 Aright curved arrow G. These mutations were involved in the altered coding of amino acids. According to the BIC database, clinical significance of these mutations is regarded as favor polymorphisms. Therefore, these genetic variations are not believed to be involved in the development of the disease, but may be associated with breast/ovarian cancers in another yet undefined way. For further clinical significance of these variations, additional study such as a case-controlled haplotyping study is needed.

BRCA1 Protein↗

PubMed2005

Decreased galectin-3 expression during the progression of cervical neoplasia.

PURPOSE: Galectin-3 is expressed widely in epithelial and immune cells and the level of expression varies in many cancer cells relative to the normal tissues from which they arise. We investigated whether the expression of galectin-3 is associated with the progression of cervical neoplasia. METHODS: Galectin-3 expression was evaluated in fresh frozen tissues of cervical carcinoma using real-time quantitative RT-PCR. In addition, galectin-3 expression was evaluated at the protein level by immunohistochemistry in 90 formalin-fixed paraffin-embedded cervical tissues, 10 normal cervical specimens, 20 low-grade squamous intraepithelial lesions (LSILs), 20 high-grade squamous intraepithelial lesions (HSILs), and 40 invasive squamous cell carcinomas (ISCCs). RESULTS: Real-time quantitative RT-PCR revealed that galectin-3 expressions in tumor cells were significantly downregulated compared with corresponding normal tissue (P=0.005). Moreover, immunohistochemistry showed that galectin-3 expression was strong in all normal cervical squamous epithelia and gradually decreased in accordance with the histopathologic grades in order LSIL>HSIL>ISCC (P<0.001). CONCLUSIONS: These data constitute the first observation that the expression of galectin-3 is downregulated in cervical cancer tissues and suggest that the decreased expression of this galactoside-binding lectin is associated with the progression of cervical neoplasia.

Disease Progression↗

PubMed2005

eIF-4E expression is associated with histopathologic grades in cervical neoplasia.

Translation initiation factor eIF-4E (eukaryotic initiation factor 4E) is a 25 kd messenger RNA cap-binding phosphoprotein and is involved in the initiation of protein synthesis. The expression is known to be elevated in several carcinomas as compared with normal tissues and benign lesions. In the present study, we undertook to determine whether eIF-4E expression is associated with progression in cervical neoplasia. eIF-4E expression was evaluated by immunohistochemistry in 88 formalin-fixed, paraffin-embedded cervical tissues; 10 normal cervical specimens; 19 low-grade cervical intraepithelial neoplasias (CINs); 19 high-grade CINs; and 40 invasive squamous cell carcinomas (ISCCs). In addition, eIF-4E expression was evaluated at the RNA level in fresh frozen cervical carcinoma tissues by real-time quantitative reverse transcriptase polymerase chain reaction. Immunohistochemical staining showed that eIF-4E expression was undetectable in most normal cervical squamous epithelial tissues (90%), but variable staining was observed in the basal layer of all normal endocervical glands. eIF-4E expression, which was mainly observed as cytoplasmic staining, gradually increased in accordance with histopathologic grade in the order low-grade CIN < high-grade CIN < ISCC (P < .001) and, in particular, was strongly detected in all ISCC cases. Furthermore, real-time quantitative reverse transcriptase polymerase chain reaction revealed that eIF-4E expression in tumor was significantly enhanced versus normal cervical tissues (P = .037). These results suggest that eIF-4E may play a significant role in tumor progression of cervical neoplasia and may represent useful markers for malignant transformation of cervical squamous cells.

Biomarkers, Tumor↗

PubMed2005

Adenoid cystic carcinoma of the Bartholin's gland: report of two cases and review of the literature.

BACKGROUND: Adenoid cystic carcinoma (ACC) of the Bartholin's gland is a rare malignancy of the female genital tract and there have been 62 cases of ACC of the Bartholin's gland in the literature. CASES: Two cases of ACC of the Bartholin's gland are reported. CONCLUSION: There is no consensus on optimal treatment of ACC of the Bartholin's gland. Most commonly, wide local excision and radical vulvectomy with or without lymph node dissection, are performed. More long-term follow up is recommended to evaluate optimal primary treatment and roles of radiotherapy and chemotherapy because ACC of the Bartholin's gland recurs and metastasizes long after primary treatment.

Adult↗

PubMed2005

The identification of apoptosis-related residues in human thymosin beta-10 by mutational analysis and computational modeling.

Thymosin beta-10 (TB10) is an actin monomer-sequestering peptide that consists of 43 amino acid residues and that tends to form alpha-helical structures. Previously, we showed that the overexpression of TB10 dramatically increases the frequency of apoptosis in human ovarian cancer cells. To identify the critical residues responsible for TB10-mediated apoptosis, we used a series of computational methods. First, a three-dimensional structure of human TB10 was constructed using the homology modeling method with the calf thymosin beta-9 NMR structure as a template. Although the sequences of both of these structures are almost identical, 200-ps molecular dynamics simulation results showed that their secondary structures differ. Analyses of molecular dynamics snapshot structures suggested that the TB10 structure is conformationally more complicated than the TB9 structure. The conserved 17LKKTET(22 motif region of TB10 was tested by Ala and Ser scanning mutagenesis using computational and biochemical methods, and 12 mutants were transfected into cancer cell lines and tested for their effects on growth arrest. Of the 12 mutants examined, only the Thr20 to Ser20 mutation showed reduced growth arrest. These results strongly suggest that Thr20 is specifically required for actin sequestration by TB10 in ovarian cancer cells. These results may provide useful information for the development of a new ovarian cancer therapy.

Actins↗

PubMed2005

Bcl-2 promotes invasion and lung metastasis by inducing matrix metalloproteinase-2.

Bcl-2 is involved in the progression of human malignancies, but the precise role and mechanism of Bcl-2 for tumor invasion and metastasis remains unclear. In this study, we have investigated the role and mechanism of Bcl-2 on tumor cell invasion and metastasis by using Bcl-2 overexpressing non-small cell lung cancer cells. Matrix metalloproteinases (MMPs) are important proteins involved in the processes of tumor invasion and metastasis. In vitro Matrigel invasion assays showed that Bcl-2 overexpression increased tumor cell invasion by 15-fold. Moreover, Bcl-2 overexpression enhanced in vivo lung metastasis by 4-fold. Consistent with its effect on invasion and metastasis, Bcl-2 overexpression induced not only MMP-2 mRNA and its protein expression, but this also activated the pro-MMP-2 protein to its active form. To explore the induction mechanism of MMP-2 by Bcl-2, we investigated the effects of Bcl-2 overexpression on MMP-2 transcriptional regulation. Nuclear run-on assays showed a 6-fold increase in the transcription rate of MMP-2 mRNA in the Bcl-2 transfectants (H157/Bcl-2) compared with that of the H157/vector control cells (H157/C). Overexpression of Bcl-2 induced the nuclear transcription factor activator protein 1 family, including the c-Jun, JunD, c-Fos, FosB, and Fra-1 proteins. Reporter assays combined with deletion mutagenesis analysis and gel shift assays showed the involvement of activator protein 1 in the activation of MMP-2 promoter activity by Bcl-2. Taken together, we have shown that Bcl-2 promotes tumor invasion and lung metastasis by inducing MMP-2 gene expression through the combined action of transcriptional and posttranslational mechanisms.

Animals↗

PubMed2005

Arsenic trioxide represses constitutive activation of NF-kappaB and COX-2 expression in human acute myeloid leukemia, HL-60.

It has been proposed that eukaryotic nuclear factor nuclear factor kappa-B (NF-kappaB) and cyclooxygenase-2 (COX-2) are implicated in the pathogenesis of many human diseases including cancer. Arsenic has been widely used in medicine in Oriental countries. Recent studies have shown that arsenic trioxide (As(2)O(3)) could induce in vitro growth inhibition and apoptosis of malignant lymphocytes, and myeloma cells. However, the molecular mechanisms by which As(2)O(3) initiates cellular signaling toward cell death are still unclear. In the present study, the effects of As(2)O(3) on NF-kappaB and COX-2 expression in HL-60 cells were investigated. As(2)O(3) suppressed DNA-binding activity of NF-kappaB composed of p65/p50 heterodimer through preventing the degradation of IkappaB-alpha and the nuclear translocation of p65 subsequently as well as interrupting the binding of NF-kappaB with their consensus sequences. Inhibitory effect of As(2)O(3) on NF-kappaB DNA activity was dependent upon intracellular glutathione (GSH) and H(2)O(2) level, but not superoxide anion. Futhermore, we found that As(2)O(3) also downregulated the expression of COX-2, which has NF-kappaB binding site on its promoter through repressing the NF-kappaB DNA-binding activity.

Apoptosis↗

PubMed2005

Insulin-like growth factor binding protein 2 promotes ovarian cancer cell invasion.

BACKGROUND: Insulin-like growth factor binding protein 2 (IGFBP2) is overexpressed in ovarian malignant tissues and in the serum and cystic fluid of ovarian cancer patients, suggesting an important role of IGFBP2 in the biology of ovarian cancer. The purpose of this study was to assess the role of increased IGFBP2 in ovarian cancer cells. RESULTS: Using western blotting and tissue microarray analyses, we showed that IGFBP2 was frequently overexpressed in ovarian carcinomas compared with normal ovarian tissues. Furthermore, IGFBP2 was significantly overexpressed in invasive serous ovarian carcinomas compared with borderline serous ovarian tumors. To test whether increased IGFBP2 contributes to the highly invasive nature of ovarian cancer cells, we generated IGFBP2-overexpressing cells from an SKOV3 ovarian cancer cell line, which has a very low level of endogenous IGFBP2. A Matrigel invasion assay showed that these IGFBP2-overexpressing cells were more invasive than the control cells. We then designed small interference RNA (siRNA) molecules that attenuated IGFBP2 expression in PA-1 ovarian cancer cells, which have a high level of endogenous IGFBP2. The Matrigel invasion assay showed that the attenuation of IGFBP2 expression indeed decreased the invasiveness of PA-1 cells. CONCLUSIONS: We therefore showed that IGFBP2 enhances the invasion capacity of ovarian cancer cells. Blockage of IGFBP2 may thus constitute a viable strategy for targeted cancer therapy.

Cell Line, Tumor↗

PubMed2005

Homeobox Msx1 interacts with p53 tumor suppressor and inhibits tumor growth by inducing apoptosis.

The stability of wild-type p53 is critical for its apoptotic function. In some cancers, wild-type p53 is inactivated by interaction with viral and cellular proteins, and restoration of its activity has therapeutic potential. Here, we identify homeobox Msx1 as a p53-interacting protein and show its novel function as a p53 regulator. Overexpression of homeobox Msx1 induced apoptosis of cancer cells harboring nonfunctional wild-type p53 and suppressed growth of human tumor xenografts in nude mice. The homeodomain of Msx1 functions as a protein-protein interacting motif rather than a DNA-binding domain and is essential for stabilization, nuclear accumulation, and apoptotic function of wild-type p53. The identification of a novel function of Msx1 as a p53 regulator may open new avenues for developing improved molecular therapies for tumors with a nonmutational p53 inactivation mechanism.

Animals↗