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Epidemiological analysis of intra-oral rhabdomyosarcoma in a Nigerian population
Cancer CK19 mRNA level (P = 0.003), and great correlation was found between tissue CK19 protein expression and saliva Cyfra 21-1 concentration (P = 0.051). Conclusions: Increased CK19 expression in OSCC tissues plays an important role in the increase of saliva Cyfra 21-1 concentration. Potential clinical value of saliva Cyfra 21-1 detection is suggested for OSCC. doi:10.1016/j.ijom.2007.08.018
O2.4 Antitumour activity of cationic liposome-mediated Bax mRNA transfer for mandibular osteosarcoma: in vitro and in vivo analysis K. Okumura*, M. Nakase, S. Nakamura, M. Inui, T. Tagawa Department of Dentistry and Oral Surgery, National Mie Hospital, 357 Ozato-kubota, Tsu, Mie 514-0125, Japan Objective: Bax is a pro-apoptotic molecule that functions as a tumour suppressor, and Bax gene therapy is investigated for various tumour cells. On the other hand, the transfer efficiency of mRNA is higher than that of plasmid. We examined the antitumour effect of the Bax mRNA gene therapy using a cationic liposome for osteosarcoma. Materials and methods: HOSM-1 is a human mandibular osteosarcoma cell line. In vitro, we evaluated the level of Bax protein expression by Western blotting, the cell growth inhibition by MTT assay and the apoptosis detection by TUNEL assay. In vivo, liposome-Bax mRNA was locally applied to the peripheral HOSM-1 tumour transplanted into nude mice, and then applied once every 2 days for a total of 10 times. Results: In the cells treated with Bax mRNA, enhanced expression of Bax protein was observed, the cell survival rate was 22.6%, and apoptosis index accounted for 43.2%. Tumour growth decreased during the administration period, and the mean tumour volume on the last day of administration was 49.1% of that in the saline control group. Conclusion: These results suggest that Bax mRNA gene therapy using a cationic liposome is an effective strategy for osteosarcoma. doi:10.1016/j.ijom.2007.08.019
O2.5 Study of cGMP-related phosphodiesterase in human oral malignant melanoma cell line
K. Shimizu*, T. Murata, Y. Watanabe, K. Hiramoto, M. Sekida, T. Tagawa Department of Oral and Maxillofacial Surgery, Mie University Graduate School of Medicine, Japan Objective: By catalysing hydrolysis of cGMP and cAMP, phosphodiesterases (PDEs) to regulate intracellular concentrations and effects of these second messengers. Eleven different but structurally related PDE gene families (PDE1– PDE11) have been identified. Although, there is considerable information regarding PDEs in normal cells, little is known of their expression and role in malignant melanoma cells. In this study, we examined the expression and the effect of cGMP related PDE in human oral melanoma HMG cells. Materials and methods: Cell line: Human oral malignant melanoma HMG, which was established from gingival melanoma and maintained in our laboratory was used. PDE5 activity: PDE activity was measured with/without PDE5 inhibitor zaprinest. RTPCR: Total RNA was extracted from the cells, and first-strand cDNA was generated. Using primer pairs specific for PDE5, PCR amplification was carried out. Results: The growth of HMG cells was stimulated by the cGMP analogues. Total PDE activity was inhibited by zaprinest. PDE5A mRNAs were detected by RT-PCR from the cells. Conclusion: These data suggest that cGMP stimulates the growth of HMG cells and PDE5A regulates cGMP concentration in HMG cells. doi:10.1016/j.ijom.2007.08.020
O2.6 High-risk human papillomavirus type 16 E7 oncogene associates with Cdc25A over-expression in oral squamous cell carcinoma U.K. Bhawal*, M. Sugiyama, K. Tsukinoki Department of Diagnostic Science, Division of Pathology & High-Tech Research Center, Kanagawa Dental College, 82 Inaoka cho, Yokosuka 238-8580, Kanagawa, Japan Repression of human papillomavirus (HPV) E7 expression results in the subsequent accumulation of hypophosphorylated retinoblastoma protein and repression of the Cdc25A genes. To confirm Cdc25A protein expression together with HPV, molecular techniques were performed using various histological subtypes of oral carcinomas. Cdc25A protein was localized predominantly in the cell
975
nuclei in carcinomas, and high expression was found in 54% of primary tumours. HPV-16 E7 was observed in 8 (36%) of 22 oral carcinomas. We found a significant correlation between Cdc25A overexpression and HPV-16 E7 positive carcinomas. There was a strong positive correlation between Cdc25A overexpression and tumour size, TNM stage. This study suggests that Cdc25A is likely to be an important mediator in the progression of oral tumours, and HPV-16 E7 may be a sensitive indicator of the involvement of viral oncogenes in oral carcinogenesis. doi:10.1016/j.ijom.2007.08.021
O2.7 Epidemiological analysis of intra-oral rhabdomyosarcoma in a Nigerian population O.A. Fatusi*, S.O. Ajike, S.O. Olateju, E. Adebayo, O.O. Gbolahan, S.A. Ogunmuyiwa Obafemi Awolowo University Teaching Hospitals Complex, Ile-Ife, Nigeria Rhabdomyosarcoma is a comparatively rare lesion for the maxillofacial surgeon. Although documented to be the most common soft tissue sarcoma in children under 15 years of age, there is, however, a paucity of reports on the pattern of its intra-oral involvement in Nigeria. To study the epidemiology of rhabdomyosarcoma involving the oral cavity and highlight its management challenges. We reviewed 21 cases of rhabdomyosarcoma involving the oral cavity from two maxillofacial centres in Nigeria over 10 years. Data regarding age, sex, sites involved, signs and symptoms were collected on a standardized form. Data analysis was carried out using SPSS version 11.0 and significance level set at P < 0.05. There were 15 males and 6 females. Ages ranged from 24 days to 42 years (median of 11 years). Thirteen cases were below 15 years of age. The maxilla:mandible ratio was 2:1. Histopathologically, 11 cases were of embryonal type, 5 cases were of alveolar type and 5 cases were unspecified. Two patients died before they could benefit from surgery, one was adjudged inoperable and three absconded before treatment commenced. Advanced disease and poor prognosis were characteristic of the study population. There is need to address the high poverty level of this population. doi:10.1016/j.ijom.2007.08.022
O2.4 Antitumour activity of cationic liposome-mediated Bax mRNA transfer for mandibular osteosarcoma: in vitro and in vivo analysis K. Okumura*, M. Nakase, S. Nakamura, M. Inui, T. Tagawa Department of Dentistry and Oral Surgery, National Mie Hospital, 357 Ozato-kubota, Tsu, Mie 514-0125, Japan Objective: Bax is a pro-apoptotic molecule that functions as a tumour suppressor, and Bax gene therapy is investigated for various tumour cells. On the other hand, the transfer efficiency of mRNA is higher than that of plasmid. We examined the antitumour effect of the Bax mRNA gene therapy using a cationic liposome for osteosarcoma. Materials and methods: HOSM-1 is a human mandibular osteosarcoma cell line. In vitro, we evaluated the level of Bax protein expression by Western blotting, the cell growth inhibition by MTT assay and the apoptosis detection by TUNEL assay. In vivo, liposome-Bax mRNA was locally applied to the peripheral HOSM-1 tumour transplanted into nude mice, and then applied once every 2 days for a total of 10 times. Results: In the cells treated with Bax mRNA, enhanced expression of Bax protein was observed, the cell survival rate was 22.6%, and apoptosis index accounted for 43.2%. Tumour growth decreased during the administration period, and the mean tumour volume on the last day of administration was 49.1% of that in the saline control group. Conclusion: These results suggest that Bax mRNA gene therapy using a cationic liposome is an effective strategy for osteosarcoma. doi:10.1016/j.ijom.2007.08.019
O2.5 Study of cGMP-related phosphodiesterase in human oral malignant melanoma cell line
K. Shimizu*, T. Murata, Y. Watanabe, K. Hiramoto, M. Sekida, T. Tagawa Department of Oral and Maxillofacial Surgery, Mie University Graduate School of Medicine, Japan Objective: By catalysing hydrolysis of cGMP and cAMP, phosphodiesterases (PDEs) to regulate intracellular concentrations and effects of these second messengers. Eleven different but structurally related PDE gene families (PDE1– PDE11) have been identified. Although, there is considerable information regarding PDEs in normal cells, little is known of their expression and role in malignant melanoma cells. In this study, we examined the expression and the effect of cGMP related PDE in human oral melanoma HMG cells. Materials and methods: Cell line: Human oral malignant melanoma HMG, which was established from gingival melanoma and maintained in our laboratory was used. PDE5 activity: PDE activity was measured with/without PDE5 inhibitor zaprinest. RTPCR: Total RNA was extracted from the cells, and first-strand cDNA was generated. Using primer pairs specific for PDE5, PCR amplification was carried out. Results: The growth of HMG cells was stimulated by the cGMP analogues. Total PDE activity was inhibited by zaprinest. PDE5A mRNAs were detected by RT-PCR from the cells. Conclusion: These data suggest that cGMP stimulates the growth of HMG cells and PDE5A regulates cGMP concentration in HMG cells. doi:10.1016/j.ijom.2007.08.020
O2.6 High-risk human papillomavirus type 16 E7 oncogene associates with Cdc25A over-expression in oral squamous cell carcinoma U.K. Bhawal*, M. Sugiyama, K. Tsukinoki Department of Diagnostic Science, Division of Pathology & High-Tech Research Center, Kanagawa Dental College, 82 Inaoka cho, Yokosuka 238-8580, Kanagawa, Japan Repression of human papillomavirus (HPV) E7 expression results in the subsequent accumulation of hypophosphorylated retinoblastoma protein and repression of the Cdc25A genes. To confirm Cdc25A protein expression together with HPV, molecular techniques were performed using various histological subtypes of oral carcinomas. Cdc25A protein was localized predominantly in the cell
975
nuclei in carcinomas, and high expression was found in 54% of primary tumours. HPV-16 E7 was observed in 8 (36%) of 22 oral carcinomas. We found a significant correlation between Cdc25A overexpression and HPV-16 E7 positive carcinomas. There was a strong positive correlation between Cdc25A overexpression and tumour size, TNM stage. This study suggests that Cdc25A is likely to be an important mediator in the progression of oral tumours, and HPV-16 E7 may be a sensitive indicator of the involvement of viral oncogenes in oral carcinogenesis. doi:10.1016/j.ijom.2007.08.021
O2.7 Epidemiological analysis of intra-oral rhabdomyosarcoma in a Nigerian population O.A. Fatusi*, S.O. Ajike, S.O. Olateju, E. Adebayo, O.O. Gbolahan, S.A. Ogunmuyiwa Obafemi Awolowo University Teaching Hospitals Complex, Ile-Ife, Nigeria Rhabdomyosarcoma is a comparatively rare lesion for the maxillofacial surgeon. Although documented to be the most common soft tissue sarcoma in children under 15 years of age, there is, however, a paucity of reports on the pattern of its intra-oral involvement in Nigeria. To study the epidemiology of rhabdomyosarcoma involving the oral cavity and highlight its management challenges. We reviewed 21 cases of rhabdomyosarcoma involving the oral cavity from two maxillofacial centres in Nigeria over 10 years. Data regarding age, sex, sites involved, signs and symptoms were collected on a standardized form. Data analysis was carried out using SPSS version 11.0 and significance level set at P < 0.05. There were 15 males and 6 females. Ages ranged from 24 days to 42 years (median of 11 years). Thirteen cases were below 15 years of age. The maxilla:mandible ratio was 2:1. Histopathologically, 11 cases were of embryonal type, 5 cases were of alveolar type and 5 cases were unspecified. Two patients died before they could benefit from surgery, one was adjudged inoperable and three absconded before treatment commenced. Advanced disease and poor prognosis were characteristic of the study population. There is need to address the high poverty level of this population. doi:10.1016/j.ijom.2007.08.022