Telomerase expression in oral cancers

Telomerase expression in oral cancers

268 P23-8Laser surgery & Diagnosis of neoplasm laser. PDT induced central necrosis of the tumor, while viable tumor cells were found in the peripher...

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268

P23-8Laser surgery & Diagnosis of neoplasm

laser. PDT induced central necrosis of the tumor, while viable tumor cells were found in the periphery. BrdU immunohistochemistry revealed abundant positive cells in the peripheral area.

5. The Combined Treatment of External Radiation Therapy and LASER Vaporization on Oral Cancer

Watanabe, T., Okabe, S., Matsuki, K., Matsuki, S., Izumo, T., Ida, J.

were analyzed using the T R A P assay to determine the level of activity of telomerase in these tissue samples in relation to clinicopathological features. The telomerase activity was positive for 28 of 32 cancers (87.5%), negative for 4 cancers (12.5%), 3 of which were early stage cancers, and negative for all the normal tissues. Moreover, telomerase activity correlated significantly with the clinical stage and pathological grade. Most of the cancers with high telomerase activity were large in size, positive for metastasis, of an advanced stage, highly-invasive and of short survival time. Telomerase may serve as an important tumor marker in human oral cancer.

Saitama Cancer Center, Departments of Oral Surgery and Clinical Pathology, Saitama, Japan 7. Synergistic Anti-Tumor Effect of Fibronectin Against Mnrine Squamous Cell Carcinoma We have been utilizing the combined treatment of external Radiation therapy and LASER vaporization on oral cancer and obtaining satisfactory results. We have been treating oral cancer with 20 Gy of external radiation. Then, CO2 LASER vaporization therapy on primary tumors is carried out. Another 20 G y of external radiation therapy is then added. We beleive that the tumor size can be reduced by LASER vaporization during irradiation, thus raising the effects of radiation. As a result, we think that the side effects of the irradiation are reduced considerably. In recent years, methods of curative treatment for oral cancer are mainly brachytherapy and surgery, including the command operation. But either of them is a heavy burden on patients. Considering the fact that aged and compromised patients with oral cancer are increasing in number, we must not only pursue cure but also adequately consider the quality of life. The curative treatment of oral cancer, aiming at preserving as much as possible the oral-maxillofacial shape and function, is required. From this point of view, this combined treatment is quite effective in patients with oral cancer. This combined treatment is frequently given to patients who have carcinoma in the buccal mucosa. We would like to discuss some cases treated with the above mentioned therapy.

6. Telomerase Expression in Oral Cancers

Odajima, T), Yamashita, T.2, Kohama, G) 1Departments oJ Oral Surgery, and 2Molecular Biology, Sapporo Medical University School of Medicine, Sapporo, Japan Ribonucleoprotein telomerase plays an important role in maintaining stabilization of telomere length at the end of the chromosome, allowing unlimited cellular proliferation. The expression of telomerase activity is concomitant with the attainment of immortality in tumors. Recent studies suggest the possibility of telomerase as a ubiquitous tumor marker in many human tumors. Telomerase activity, however, has not yet been analyzed in oral squalnous cancer in detail. In our preliminary study, frozen tumor tissue specimens from 32 patients with oral squamous cancer and 5 normal tissues

Satomi, T., Chiba, H., Watanabe, H., Ueno, H., Watanabe, M., Kaneko, T. Department of Oral and Maxillofacial Surgery, Tokyo Medical College, Tokyo, Japan We investigated the relation between the localization of fibronectin and the expression of IL-2 m R N A in biopsy specimens of oral cancer by using immunohistochemical staining and in situ hybridization. Results indicated that FNpositive cases showed higher intensity of IL-2 m R N A signals than FN-negative cases. Therefore, the effect of the combined use of Lentinan (biological response modifiers) and fibronectin was examined by using cancer-bearing mice which were transplanted with murine squamous cell carcinoma (Gsq-1). 2• 105 carcinoma cells were transplanted into the regio-femoral~s muscle of C3H/He mice. The experiment compared the three following groups: group 1 (control), group 2 (Lentinan administration), group 3 (Lentinan and fibronectin administration). Lentinan was administered for seven days after the 10th day after the carcinoma cells had been transplanted. Moreover, fibronectin was administered to the tumor surroundings three times. The volume of the tumor in each group was measured at the time of death. The tumor growth rate between each group was compared. Group 3 showed an evident anti-tumor effect as compared with group 2. The results suggest that the anti-tumor effect of Lentinan is enhanced by fibronectin.