Vaccinations with Dendritic Cells Can Elicit Preventive Immunity in a Squamous Cell Carcinoma Animal Model / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: Dendritic cells (DC) can effectively mediate the prevention and regression of a variety of solid malignancies when they are properly primed with tumor antigens. However, little has been determined about the efficacy of DCbased vaccine for the prevention of squamous cell carcinoma (SCC). SUBJECTS AND METHOD: Bone marrow derived DC of C3H mouse were pulsed with ultraviolet B-irradiated apoptotic SCCVII cells, which are known as a poorly immunogenic SCC cell line. After vaccinations with those DC, a tumorigenic dosage of healthy SCCVII cells were challenged into the flank of animals and the tumor growth was assessed in a blinded and coded fashion. RESULTS: DC pulsed with apoptotic SCCVII cells effectively prevented the formation of solid tumor in 81% of vaccinated animals and mediated significant retardation of tumor growth (p=0.0029) in 19% of vaccinated animals when compared to control groups. SCCVII cell-specific T-cell response (IFN-gamma production) was observed in the immunized mice. CONCLUSION: Adoptive transfer of DC primed with apoptotic SCCVII cells can serve as an effective preventive vaccine in the poorly immunogenic SCC animal model.

A Study of Microvessel Density, P53, Ki67, and DNA Flowcytometry in Cervical Lymph Node Metastasis of Squamous Cell Cancer in Head and Neck / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: Lymph node metastasis is believed to be the single most important prognostic factor in the head and neck squamous cell cancer. To identify potential biological parameters for predicting cervical lymph node metastasis, we evaluated the relationship between cervical nodal status and several parameters, such as microvessel density, p53, Ki67, and DNA ploidy, and compared it with the conventional clinical parameters including histologic grade of the tumors. MATERIALS AND METHOD: This study group included 26 specimens from the primary sites of patients who were diagnosed with squamous cell cancers of the head and neck. Immunohistochemstry and DNA flowcytometry were performed at almost the same sections of the primary sites. To quantify angiogenesis, the microvessel density was determined by counting the number of the vascular endothelial cells positively stained with CD-31 under the magnification filed power of 200 by two investigators; the cell number was determined by taking the average of the highest values of three counts made by each investigator. Immunohistochemical staining with Ki67 and p53 were also done to evaluate the cellular proliferation of tumors and the overexpression of mutated tumor suppressor gene. DNA flowcytometry was performed to evaluate the ploidy and proliferation index. These results were compared and analyzed with clinical parameters. RESULTS: All of the parameters failed to show a significant relationship to nodal status in this study. However, the microvessel density of the laryngeal cancers showed a statistically significant relationship with the cervical nodal metastasis (p=0.045). CONCLUSION: The microvessel density may have a correlation to the lymph nodal metastasis in the head and neck squamous cell cancer and may be regarded as an additional prognostic factor for planning treatment.

The Patterns of Expression of p53, bcl-2 and Bax after Irradiation in Cell Lines of Squamous Cell Carcinoma of Head and Neck / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: Squamous cell carcinoma of head and neck (HNSCC) undergoes a generally poor hospital course, and response of radiotherapy remains in questionable status. For this carcinoma, the clinical courses, biological behaviors and responses to radiotherapy are variable among cases and difficult to predict accurately. MATERIALS AND METHODS: As a trial to elucidate the prognostic factors of HNSCC after radiotherapy, several responses following irradiation of HNSCC cell lines and the expressions of apoptosis-related markers, such as p53, bcl-2, and Bax, were evaluated in this study. RESULTS: Among the eight HNSCC cell lines, the AMC-HN 1 was considered to be radioresistant, the PCI-1 was radiosensitive, and the AMC-HN 8 showed intermediate response. In immunohistochemistry of p53, AMC-HN 1 was negative, PCI-1 was strongly positive, and AMC-HN 8 was weakly positive. However, the analysis of mRNA using RT-PCR implied different expressions of p53 in the mRNA level. All 3 cell lines showed the p53 mRNA expressions. After irradiation of 2 Gy (137Cs), changes in the expressions of apoptosis-related protein (p53, bcl-2, Bax) were analyzed with the Western blot assay. The p53 and bcl-2 did not show any difference in the expressions between the irradiation group and the non-irradiation group. However, there was a significant difference in the Bax expression in the radiosensitive cell line (PCI-1) after irradiation. CONCLUSION: Those results might imply some roles of Bax in apoptotic responses following radiotherapy. Therefore, further studies should look into finding other possible factors and markers of HNSCC after radiotherapy and the precise role of Bax.

p53 Mutation of Head and Neck Squamous Cell Carcinoma Cell Lines / 대한암학회지

PURPOSE: Structural alterations of p53 and overexpression of the p53 protein are the most common genetic abnormalities in various kinds of human cancers. In this study, we examined the mutational status and the frequency of p53 mutations in head and neck squamous cell carcimona (HNSCC) cell lines. MATERIALS AND METHODS: 7 human head and neck squamous cell carcinoma cell lines were included in this analysis. Using polymerase chain reaction(PCR), single strand confonmation polymorphism(SSCP) and PCR-DNA sequencing analysis, we tested the mutational status of 7 cell lines. Exon 4~9 of the p53 gene was amplified for the direct DNA sequencing analysis. RESULTS: Our results showed 100% nuclear p53 immunostaining and 3 electrophoretic abnomalities by PCR-SSCP in three cancer cell lines and mutations of the p53 gene including 2 base substitutions and 1 base deletion were detected in 3 cancer cell lines using PCR directed DNA sequencing analysis. CONCLUSION: 7 HNSCC cell lines examined in this study provide excellent systems for study of gene therapy using p53 gene.