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Oncogene protein co-expression in oral cancer and its possible association with tumor progression
P21-6 Tumor biology 6. A Study on Mutations of p53 Tumor Suppressor Gene in Oral Tumors
Joo, S. C., Nam, L W.., Choung, R H., Kim, 3/1. s Department of Oral and Maxillofacial Surgery, College of Dentistry, Seoul National University, Seoul, Korea In this study we analyzed 20 specimens of oral tumors (14 cases of squamous cell carcinoma, 3 cases of ameloblastoma, 2 cases of adenocystic carcinoma, 1 case of malignant Schwannoma) using polymerase chain reaction and direct sequencing and an automated D N A sequencer and software for detection of mutations. Polymerase chain reactions were performed with 4 sets of primers encompassing exon 5, 6, 7, 8, and a direct sequencing method was employed. The results were as follows: 1. Ten point mutations out of 20 specimens (50%) were detected. 2. The genetic alterations included 7 missense mutations resulting in single amino acid subtitutions, 2 silent mutations, 1 nonsense mutation encoding a stop codon. 3. Mutations were mostly in exon 7 (7 out of 10 mutations) and involved codons 225, 234, 235, 236, 238, 247. 4. Therse were 4 cases of T---)vA transversion of C--*vA transversion, A---~vG transition, 1 case of C--~vG and T--+vG transversion respectively. 5. Point mutations were more conveniently found using PCR Automated Direct Sequencing method.
7. Cell Proliferation and Apoptosis in the Rabbit VX2 Tongue Cancer Model
Matsuda, A), Takeda, S.. 1, Fujisawa, K), Nakayama, A. 1, Izumisawa, M. 1, Satoh, M. 2, Kudo, If. 1 1First Department of Oral and Maxillofacial Surgery and 2Department of Oral Pathology School of Dentistry, Iwate Medical University, Iwate, Japan Introduction The balance between proliferation and apoptosis of cancer cells is important in the development of cancer. In this study, we transplanted VX2 cancer into the tongue and examined the proliferation of cancer cells in the tongue and the metastasized cancer of deep cervical lymph nodes. Then we studied the relation between these results and the occurrence of apoptosis. Methods Animals were sacrificed on the 7th, 14th, 21st and 28th day after the transplantation of VX2 cancer cells into the tongue. The tongue and deep cervical lymph nodes were removed and embedded in paraffin. Then 3 gm consecutive sections were prepared and stained with HE and AgNORs. The number of AgNORs in the nuclei of 100 cancer cells was calculated, and the mean number per nucleus was determined.
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The presence of apoptosis was examined by the TdT-mediated dUTP-biotin nick end labeling (TUNEL) method. Results (1) The mean number of AgNORs per cancer cell in the invading border of the tongue cancer nodule increased up to 14 days after transplantation and then slightly decreased. On the other hand, the mean number of AgNORs in the center of the cancer nodule tended to decrease with time. (2) The mean number of AgNORs of the metastasized nodules in the lymph nodes was slightly higher than that in the tongue. (3) In the metastasized nodules of lymph nodes, the mean number of AgNORs on the capsule side were slightly higher than those at the invading edge. We will also report the relation between the number of AgNORs with the occurrence of apoptosis.
8. Oncogene Protein Co-Expression in Oral Cancer and its Possible Association with Tumor Progression
Shiraki, g . 1, Odajima, T.1, Tanaka, N. l, Nagai, L 1, Yamashita, T.2, Kohama, (7,.1 1Department of Oral Surgery, 2Department of Molecular Biology, Sapporo Medical University School of Medicine, Sapporo, Japan Expression of p53 protein, bcl-2 protein, cyclin D1 protein and epidermal growth factor receptor (EGFR) was assessed by immunohistochemical staining of tumor tissue sections from 103 oral cancers. The correlation between aberrant expression of each protein, clinicopathological variables and survival of the patients was analyzed. Overexpression of p53 protein was correlated well with lymph node metastasis and clinical stage. Although no significant correlation was found between clinicopathological variables and expression of cyclin D1 protein and E G F R , these protein expressions were correlated significantly with tumor recurrence. The prognoses of the patients with overexpression of p53 protein, cyclin D1 protein and E G F R were significantly worse than of those without overexpression of these oncogene proteins. In contrast, overexpression of bcl-2 protein showed no relation to patient outcome, despite a correlation with lymph node metastasis. However, increasing co-oncogene protein expression correlated with the most significant reduction in overall survival. Co-expression of these oncogene proteins may possibly be associated with oral cancer progression.
Joo, S. C., Nam, L W.., Choung, R H., Kim, 3/1. s Department of Oral and Maxillofacial Surgery, College of Dentistry, Seoul National University, Seoul, Korea In this study we analyzed 20 specimens of oral tumors (14 cases of squamous cell carcinoma, 3 cases of ameloblastoma, 2 cases of adenocystic carcinoma, 1 case of malignant Schwannoma) using polymerase chain reaction and direct sequencing and an automated D N A sequencer and software for detection of mutations. Polymerase chain reactions were performed with 4 sets of primers encompassing exon 5, 6, 7, 8, and a direct sequencing method was employed. The results were as follows: 1. Ten point mutations out of 20 specimens (50%) were detected. 2. The genetic alterations included 7 missense mutations resulting in single amino acid subtitutions, 2 silent mutations, 1 nonsense mutation encoding a stop codon. 3. Mutations were mostly in exon 7 (7 out of 10 mutations) and involved codons 225, 234, 235, 236, 238, 247. 4. Therse were 4 cases of T---)vA transversion of C--*vA transversion, A---~vG transition, 1 case of C--~vG and T--+vG transversion respectively. 5. Point mutations were more conveniently found using PCR Automated Direct Sequencing method.
7. Cell Proliferation and Apoptosis in the Rabbit VX2 Tongue Cancer Model
Matsuda, A), Takeda, S.. 1, Fujisawa, K), Nakayama, A. 1, Izumisawa, M. 1, Satoh, M. 2, Kudo, If. 1 1First Department of Oral and Maxillofacial Surgery and 2Department of Oral Pathology School of Dentistry, Iwate Medical University, Iwate, Japan Introduction The balance between proliferation and apoptosis of cancer cells is important in the development of cancer. In this study, we transplanted VX2 cancer into the tongue and examined the proliferation of cancer cells in the tongue and the metastasized cancer of deep cervical lymph nodes. Then we studied the relation between these results and the occurrence of apoptosis. Methods Animals were sacrificed on the 7th, 14th, 21st and 28th day after the transplantation of VX2 cancer cells into the tongue. The tongue and deep cervical lymph nodes were removed and embedded in paraffin. Then 3 gm consecutive sections were prepared and stained with HE and AgNORs. The number of AgNORs in the nuclei of 100 cancer cells was calculated, and the mean number per nucleus was determined.
177
The presence of apoptosis was examined by the TdT-mediated dUTP-biotin nick end labeling (TUNEL) method. Results (1) The mean number of AgNORs per cancer cell in the invading border of the tongue cancer nodule increased up to 14 days after transplantation and then slightly decreased. On the other hand, the mean number of AgNORs in the center of the cancer nodule tended to decrease with time. (2) The mean number of AgNORs of the metastasized nodules in the lymph nodes was slightly higher than that in the tongue. (3) In the metastasized nodules of lymph nodes, the mean number of AgNORs on the capsule side were slightly higher than those at the invading edge. We will also report the relation between the number of AgNORs with the occurrence of apoptosis.
8. Oncogene Protein Co-Expression in Oral Cancer and its Possible Association with Tumor Progression
Shiraki, g . 1, Odajima, T.1, Tanaka, N. l, Nagai, L 1, Yamashita, T.2, Kohama, (7,.1 1Department of Oral Surgery, 2Department of Molecular Biology, Sapporo Medical University School of Medicine, Sapporo, Japan Expression of p53 protein, bcl-2 protein, cyclin D1 protein and epidermal growth factor receptor (EGFR) was assessed by immunohistochemical staining of tumor tissue sections from 103 oral cancers. The correlation between aberrant expression of each protein, clinicopathological variables and survival of the patients was analyzed. Overexpression of p53 protein was correlated well with lymph node metastasis and clinical stage. Although no significant correlation was found between clinicopathological variables and expression of cyclin D1 protein and E G F R , these protein expressions were correlated significantly with tumor recurrence. The prognoses of the patients with overexpression of p53 protein, cyclin D1 protein and E G F R were significantly worse than of those without overexpression of these oncogene proteins. In contrast, overexpression of bcl-2 protein showed no relation to patient outcome, despite a correlation with lymph node metastasis. However, increasing co-oncogene protein expression correlated with the most significant reduction in overall survival. Co-expression of these oncogene proteins may possibly be associated with oral cancer progression.