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Expression of p16 in Oral Squamous Cell Carcinoma, Potentially Malignant Disorders and Normal Mucosa
OOOO Volume 119, Number 3 Study Design: We submitted 130 formalin-fixed, paraffinembedded OSCC specimens for DNA extraction (30 specimens of OSCC with LNM; 100 specimens of OSCC without LNM). HPV infection was detected by PCR using a HPV type 16-specific primer. Results: Eight(26.7%) of 30 primary tumors(PT) were positive for HPV-16 DNA, 3(10.0%) of 30 PT with LNM were positive, and 43(43.0%) of 100 tumors were positive. Conclusions: The results of the present investigation indicate that HPV-16 infection rate of OSCC with LNM was lower than that for OSCC without LNM. In the case of OSCC with LNM, HPV-16 infection rates of both PT and LNM were lower. It is suggested that OSCC associated with HPV infection has a lower incidence in LNM. Therefore, it appears that HPV infection may be a diagnostic indicator of metastasis. Keywords: HPV, oral squamous cell carcinoma, metastasis, diagnosis
NOVEL CYTOKINES IN THE PATHOGENESIS OF ORAL MUCOSAL LICHEN PLANUS Ramya Javvadi, Venkata Parachuru, Trudy Milne, Gregory Seymour, Alison Rich, Sir John Walsh Research Institute, Faculty of Dentistry, University of Otago, New Zealand Objective: Oral mucosal lichen planus (OMLP) is a complex immunological disorder of skin and oral mucosa, mediated in part by the release of cytokines by activated T-cells. The aim of this study was to identify the presence of novel cytokines such as IL17, IL33 and IL35 in OMLP using immunohistochemistry (IHC). Study Design: IHC staining was performed on 12 OMLP and 7 non-specific inflammatory (NSI) archival tissues using antibodies against IL17, IL33 and IL35. Quantitative and qualitative analysis was performed. Results: Preliminary results showed the presence of IL17+, IL33+ and IL35+ cells in both OMLP and NSI tissues. More IL17+ and IL35+ cells were present in control tissues than in OMLP tissues, while IL33+ cells are relatively more common in OMLP. IL33 staining was observed in the basal layer of the epithelium in both OMLP and in the controls. Conclusions: These results suggest a possible role for these cytokines in the pathogenesis of OMLP. Keywords: Lichen planus, IL33, IL35, IL17
H3K9ME3 BINDING TO THE DNA PROMOTER CAUSES THE INACTIVATION OF EDNRB GENE IN ACC TUMORS Rong Hui Xia, Chun Ye Zhang, Yu Hua Hu, Ting Gu, Li Zhen Wang, Jiang Li, Department of Oral Pathology, 9th People’s Hospital, Shanghai Jiao Tong University, School of Medicine, Shanghai Key Laboratory of Stomatology, Shanghai, P.R. China Objective: To study whether the epigenetic mechanisms cause the silence of EDNRB (endothelin receptor type B) gene, a new candidate tumor suppressor in salivary adenoid cystic carcinoma (ACC). Study Design: Protein expression of EDNRB, DNA methylation and histone H3 lysine 9 trimethylation (H3K9me3) of EDNRB gene were detected in a total of 33 paired ACC tumors and adjacent normal tissues by Western Blot, methylation-specific PCR (MSP) and chromatin immunoprecipitation (ChIP) respectively. Results: 60.61% (20/33) ACC samples showed lower EDNRB expression than that in normal tissues. EDNRB promoter hypermethylation rate in ACC was not significantly higher than
ABSTRACTS Abstracts e183 that in normal tissues (51.52% versus 40.00%, p ¼ 0.721). However, significantly higher frequency of H3K9me3 binding to EDNRB promoter was found in ACC samples than that in normal tissues (96.97% versus 54.55%, p ¼ 0.000). Conclusions: H3K9me3 might play an important role in inactivation of EDNRB gene and cause the tumorigenesis of ACC tumors. Keywords: salivary adenoid cystic carcinoma, methylation, histone H3 lysine 9, trimethylation
PAX9 EXPRESSION IN POTENTIALLY MALIGNANT DISORDERS AND EARLY STAGE SQUAMOUS CELL CARCINOMA OF THE ORAL CAVITY Timothy John Bates, Renna Mahsoub, Peter Thomson, Philip Sloan, Max Robinson, Ralf Kist, Centre for Oral Health Research, Newcastle University, Newcastle, UK Objective: PAX9 is a transcription factor that regulates epithelial differentiation. PAX9 is progressively lost during oesophageal carcinogenesis and is thought to act as a tumoursuppressor. The role of PAX9 in the formation of oral squamous cell carcinoma (OSCC) and its precursors, oral potentially malignant disorders (OPMD), is unknown. Study Design: PAX9 expression was determined by immunohistochemistry in 199 oral mucosal biopsies, including normal oral mucosa, OPMD and OSCC. Staining was quantified by image analysis. Data were correlated with patient and clinicopathological parameters. Results: PAX9 expression was down-regulated in OPMD and OSCC compared to normal epithelium (p<0.05). However, OPMD with high levels of PAX9 expression were more likely to undergo malignant transformation to OSSC. Conclusions: PAX9 down-regulation in OPMD/OSSC is consistent with its role as a tumour-suppressor. In OPMD, elevated PAX9 expression was associated with transformation to cancer. Deregulated PAX9 appears to have a pivotal in oral carcinogenesis and may be stage dependent. Keywords: PAX9, oral cancer, oral potentially malignant disorders, oral carcinogenesis, oral squamous cell carcinoma
EXPRESSION OF P16 IN ORAL SQUAMOUS CELL CARCINOMA, POTENTIALLY MALIGNANT DISORDERS AND NORMAL MUCOSA Manohari Muniswamy, Rajasekaran Sudharsan, Uma Devi K. Rao, Elizabeth Joshua, Kannan Ranganathan, Department of Oral and Maxillofacial Pathology, Ragas dental college and hospital, Chennai, India Objective: To study the expression of p16 in normal mucosa (Group I), oral submucous fibrosis (OSF, Group II), epithelial dysplasia (Group III) and oral squamous cell carcinoma (OSCC, Group IV), by immunohistochemistry. Study Design: Study comprised of 10 cases in Group I and 20 cases each in the remaining groups. Positive control used was squamous cell carcinoma of uterine cervix. Results: p16 expression positivity was seen in 50%, 35%, 5% and 15% of group I, II, III and IV, respectively. p16 tissue localisation in basal and suprabasal layers showed a significant difference between the groups. Of 7 OSF cases that showed p16 expression, 4 cases showed suprabasal staining and 5 cases showed nuclear and cytoplasmic staining. Conclusions: p16 suprabasal staining in OSF, suggests that p16 could be used as an early marker of malignant transformation
ORAL AND MAXILLOFACIAL PATHOLOGY e184 Abstracts and based on the staining pattern we postulate that it could indicate HPV infection. Keywords: p16, OSF, OSCC, Epithelial Dysplasia
INTRAORAL CARCINOMA CUNICULATUM. CHALLENGING DIAGNOSIS OF TWO CASES Fabian Ocampo Acosta1, Beatriz Catalina Aldape Barrios2, Alejandro Seamanduras Pacheco1, Edgar Ramiro Méndez Sanchez1, Paris Astrid Mier Maldonado1, 1Department of Oral Pathology, Faculty of Dentistry, Autonomous University of Baja California, Tijuana, Mexico; 2Department of Oral Pathology, Faculty of Dentistry, National Autonomous University of Mexico, Mexico DF Carcinoma cuniculatum (CC) is a distinct variant of oral squamous cell carcinoma (OSCC). The tumor was first described by Arid in 1954 and has been reported in skin, penis, esophagus, abdomen, sole and palm. Oral CC was first described by Flieger and is now considered as a new malignant neoplasm of epithelial origin variant characterized by cuniculatum architecture, which is similar in appearance to rabbit burrows, and formed by keratinfilled branching crypts and keratin cores. Despite the lack of cellular atypia, oral CC shows an aggressive local behavior; some other entities like verrucous carcinoma, orthokeratinized odontogenic cyst and keratocystic odontogenic tumor could be mistaken either clinically or histopathologically. Two cases involving anterior maxilla and mandible of intraoral CC are presented. A reliable medical record, oral examination, imagenology, surgical findings, histopathology and immunohistochemistry panel are of help to achieve correct diagnosis and avoid any delay of treatment. Keywords: Carcinoma cuniculatum, verrucous carcinoma, odontogenic cysts, odontogenic tumors, oral cavity, jaws
PRIMARY MALIGNANT MELANOMA OF THE NASAL CAVITY Tulay Basak1, Ozben Yalcin1, Deniz Tuncel1, Rabia Yakar1, Berna Uslu Coskun2, Fevziye Kabukcuoglu1, 1 Department of Pathology, Sisli Hamidiye Etfal Education and Research Hospital, Istanbul, Turkey; 2Department of Head and Neck Surgery, Sisli Hamidiye Etfal Education and Research Hospital, Istanbul, Turkey Primary malignant melanoma of the nasal cavity is a rare entity which occurs in less than 1% among all melanomas. We present a 62 year-old-male with a polypoid mass in both sides of the nasal cavity. Histological examination revealed a lesion with large areas of ulcerations in the squamous epithelium. It was composed of diffusely scattered large atypical cells with round, spindle-shaped and irregular nuclei and scanty fibrous connective tissue with myxoid alterations in the background. Immunohistochemical study demonstrated positive staining for Melan-A, HMB-45, S-100 and negative for Cytokeratin. Ki-67 proliferation index was 85%. According to the morphological and immunohistochemical staining, it was diagnosed as malignant melanoma. No other foci have been found in the clinical evaluation. The tumor was considered as the primary malignant melanoma of the nasal cavity. Keywords: malignant, melanoma, nasal, cavity
RADICAL SURGICAL APPROACH TO A RECURRENT PERIFERAL GIANT CELL GRANULOMA: A CASE REPORT Mehmet Kemal Tumer1, Nihat Akbulut1, Emine Sebnem Kursun2, Akgül Arıcı3, Alper Sindel4, 1Department of Oral and Maxillofacial Surgery, Faculty of Dentistry,
OOOO March 2015 Gaziosmanpasa Univeristy, Tokat, Turkey; 2Department of Oral and Maxillofacial Radiology, Faculty of Dentistry, Ankara University, Ankara, Turkey; 3Department of Pathology, Faculty of Medicine, Gaziosmanpasa Univeristy, Tokat, Turkey; 4Department of Oral and Maxillofacial Surgery, Faculty of Dentistry, Akdeniz University, Antalya, Turkey Introduction: Peripheral giant cell granuloma (PGCG) is a relatively frequent benign and also the most common giant cell lesion of the oral cavity. In terms of the treatment the most important problem of these lesion is recurrence phenomena. Case: A-32- year-old female patient was referred to our surgery clinic with upper right jaw pain and also with history of several surgical giant cell lesion operations. She had no systemically any illness. We operated the patient with partial maxillectomy. We also used the frozen section procedure during the surgery. We completed the operation after taking notice from the pathologist that the surgical margins were clean. Conclusion: One of the challenging problem for surgeons is struggling with the recurrence of PGCG lesion. In our case reported above that she was operated with using several curettage methods. So, sometimes it requires radical surgical approaches that we used in this case. Keywords: benign tumor, giant cell granuloma, maxillectomy
MAXILLARY PAROSTEAL OSTEOSARCOMA: REPORT OF A CASE WITH UNUSUAL RADIOGRAPHIC APPEARANCE AND LONG-TERM FOLLOW-UP Sara Mehrabi1, Pouria Motahhary2, 1Department of Oral Pathology, Dental School, Zanjan University of Medical Sciences, Zanjan, Iran; 2Department of Oral Pathology, Dental School, Tehran University of Medical Sciences, Tehran, Iran Parosteal osteosarcoma is an uncommon malignancy of the bone that rarely affects the jaws. A 26-year-old woman presented with 6 months history of painless swelling on the left side of the maxilla in lateral incisor/canine area. Panoramic radiograph revealed no evidence of any distinct lesion of maxillary bone and teeth in that region. The lesion was treated by local excision as a peripheral tumor. Excisional biopsy microscopic examination showed a neoplastic tissue representing chondroblastic osteosarcoma, surrounded by thick capsule. After 4 months the patient returned with enlarging swelling on the same region of previous surgery. Computerized tomography revealed a soft tissue mass causing erosion of the alveolar process and anterior wall of the maxillary sinus. Segmental resection of the maxilla and adjuvant chemotherapy with reconstruction treatment was performed. The patient was under close follow-up and at present, after 2 years is free of recurrence and in a good health status. Keywords: Osteosarcoma, Bone tumor, Jaw lesion
OSTEOBLAST-DERIVED OSTEOPONTIN INCREASES THE PROLIFERATIVE RATE OF ORAL SQUAMOUS CELL CARCINOMA CELLS IN VITRO Lucas Novaes Teixeira1, Larissa Moreira Spinola De Castro Raucci2, Roger Rodrigo Fernandes3, Ricardo Della Coletta1, Adalberto Luiz Rosa3, Paulo Tambasco De Oliveira2, 1Department of Oral Diagnosis, School of Dentistry, State University of Campinas, Piracicaba, Brazil; 2Department of Morphology, Physiology and Basic Pathology, School of Dentistry of Ribeirao Preto, University of Sao Paulo, Ribeirao Preto, Brazil; 3Department
NOVEL CYTOKINES IN THE PATHOGENESIS OF ORAL MUCOSAL LICHEN PLANUS Ramya Javvadi, Venkata Parachuru, Trudy Milne, Gregory Seymour, Alison Rich, Sir John Walsh Research Institute, Faculty of Dentistry, University of Otago, New Zealand Objective: Oral mucosal lichen planus (OMLP) is a complex immunological disorder of skin and oral mucosa, mediated in part by the release of cytokines by activated T-cells. The aim of this study was to identify the presence of novel cytokines such as IL17, IL33 and IL35 in OMLP using immunohistochemistry (IHC). Study Design: IHC staining was performed on 12 OMLP and 7 non-specific inflammatory (NSI) archival tissues using antibodies against IL17, IL33 and IL35. Quantitative and qualitative analysis was performed. Results: Preliminary results showed the presence of IL17+, IL33+ and IL35+ cells in both OMLP and NSI tissues. More IL17+ and IL35+ cells were present in control tissues than in OMLP tissues, while IL33+ cells are relatively more common in OMLP. IL33 staining was observed in the basal layer of the epithelium in both OMLP and in the controls. Conclusions: These results suggest a possible role for these cytokines in the pathogenesis of OMLP. Keywords: Lichen planus, IL33, IL35, IL17
H3K9ME3 BINDING TO THE DNA PROMOTER CAUSES THE INACTIVATION OF EDNRB GENE IN ACC TUMORS Rong Hui Xia, Chun Ye Zhang, Yu Hua Hu, Ting Gu, Li Zhen Wang, Jiang Li, Department of Oral Pathology, 9th People’s Hospital, Shanghai Jiao Tong University, School of Medicine, Shanghai Key Laboratory of Stomatology, Shanghai, P.R. China Objective: To study whether the epigenetic mechanisms cause the silence of EDNRB (endothelin receptor type B) gene, a new candidate tumor suppressor in salivary adenoid cystic carcinoma (ACC). Study Design: Protein expression of EDNRB, DNA methylation and histone H3 lysine 9 trimethylation (H3K9me3) of EDNRB gene were detected in a total of 33 paired ACC tumors and adjacent normal tissues by Western Blot, methylation-specific PCR (MSP) and chromatin immunoprecipitation (ChIP) respectively. Results: 60.61% (20/33) ACC samples showed lower EDNRB expression than that in normal tissues. EDNRB promoter hypermethylation rate in ACC was not significantly higher than
ABSTRACTS Abstracts e183 that in normal tissues (51.52% versus 40.00%, p ¼ 0.721). However, significantly higher frequency of H3K9me3 binding to EDNRB promoter was found in ACC samples than that in normal tissues (96.97% versus 54.55%, p ¼ 0.000). Conclusions: H3K9me3 might play an important role in inactivation of EDNRB gene and cause the tumorigenesis of ACC tumors. Keywords: salivary adenoid cystic carcinoma, methylation, histone H3 lysine 9, trimethylation
PAX9 EXPRESSION IN POTENTIALLY MALIGNANT DISORDERS AND EARLY STAGE SQUAMOUS CELL CARCINOMA OF THE ORAL CAVITY Timothy John Bates, Renna Mahsoub, Peter Thomson, Philip Sloan, Max Robinson, Ralf Kist, Centre for Oral Health Research, Newcastle University, Newcastle, UK Objective: PAX9 is a transcription factor that regulates epithelial differentiation. PAX9 is progressively lost during oesophageal carcinogenesis and is thought to act as a tumoursuppressor. The role of PAX9 in the formation of oral squamous cell carcinoma (OSCC) and its precursors, oral potentially malignant disorders (OPMD), is unknown. Study Design: PAX9 expression was determined by immunohistochemistry in 199 oral mucosal biopsies, including normal oral mucosa, OPMD and OSCC. Staining was quantified by image analysis. Data were correlated with patient and clinicopathological parameters. Results: PAX9 expression was down-regulated in OPMD and OSCC compared to normal epithelium (p<0.05). However, OPMD with high levels of PAX9 expression were more likely to undergo malignant transformation to OSSC. Conclusions: PAX9 down-regulation in OPMD/OSSC is consistent with its role as a tumour-suppressor. In OPMD, elevated PAX9 expression was associated with transformation to cancer. Deregulated PAX9 appears to have a pivotal in oral carcinogenesis and may be stage dependent. Keywords: PAX9, oral cancer, oral potentially malignant disorders, oral carcinogenesis, oral squamous cell carcinoma
EXPRESSION OF P16 IN ORAL SQUAMOUS CELL CARCINOMA, POTENTIALLY MALIGNANT DISORDERS AND NORMAL MUCOSA Manohari Muniswamy, Rajasekaran Sudharsan, Uma Devi K. Rao, Elizabeth Joshua, Kannan Ranganathan, Department of Oral and Maxillofacial Pathology, Ragas dental college and hospital, Chennai, India Objective: To study the expression of p16 in normal mucosa (Group I), oral submucous fibrosis (OSF, Group II), epithelial dysplasia (Group III) and oral squamous cell carcinoma (OSCC, Group IV), by immunohistochemistry. Study Design: Study comprised of 10 cases in Group I and 20 cases each in the remaining groups. Positive control used was squamous cell carcinoma of uterine cervix. Results: p16 expression positivity was seen in 50%, 35%, 5% and 15% of group I, II, III and IV, respectively. p16 tissue localisation in basal and suprabasal layers showed a significant difference between the groups. Of 7 OSF cases that showed p16 expression, 4 cases showed suprabasal staining and 5 cases showed nuclear and cytoplasmic staining. Conclusions: p16 suprabasal staining in OSF, suggests that p16 could be used as an early marker of malignant transformation
ORAL AND MAXILLOFACIAL PATHOLOGY e184 Abstracts and based on the staining pattern we postulate that it could indicate HPV infection. Keywords: p16, OSF, OSCC, Epithelial Dysplasia
INTRAORAL CARCINOMA CUNICULATUM. CHALLENGING DIAGNOSIS OF TWO CASES Fabian Ocampo Acosta1, Beatriz Catalina Aldape Barrios2, Alejandro Seamanduras Pacheco1, Edgar Ramiro Méndez Sanchez1, Paris Astrid Mier Maldonado1, 1Department of Oral Pathology, Faculty of Dentistry, Autonomous University of Baja California, Tijuana, Mexico; 2Department of Oral Pathology, Faculty of Dentistry, National Autonomous University of Mexico, Mexico DF Carcinoma cuniculatum (CC) is a distinct variant of oral squamous cell carcinoma (OSCC). The tumor was first described by Arid in 1954 and has been reported in skin, penis, esophagus, abdomen, sole and palm. Oral CC was first described by Flieger and is now considered as a new malignant neoplasm of epithelial origin variant characterized by cuniculatum architecture, which is similar in appearance to rabbit burrows, and formed by keratinfilled branching crypts and keratin cores. Despite the lack of cellular atypia, oral CC shows an aggressive local behavior; some other entities like verrucous carcinoma, orthokeratinized odontogenic cyst and keratocystic odontogenic tumor could be mistaken either clinically or histopathologically. Two cases involving anterior maxilla and mandible of intraoral CC are presented. A reliable medical record, oral examination, imagenology, surgical findings, histopathology and immunohistochemistry panel are of help to achieve correct diagnosis and avoid any delay of treatment. Keywords: Carcinoma cuniculatum, verrucous carcinoma, odontogenic cysts, odontogenic tumors, oral cavity, jaws
PRIMARY MALIGNANT MELANOMA OF THE NASAL CAVITY Tulay Basak1, Ozben Yalcin1, Deniz Tuncel1, Rabia Yakar1, Berna Uslu Coskun2, Fevziye Kabukcuoglu1, 1 Department of Pathology, Sisli Hamidiye Etfal Education and Research Hospital, Istanbul, Turkey; 2Department of Head and Neck Surgery, Sisli Hamidiye Etfal Education and Research Hospital, Istanbul, Turkey Primary malignant melanoma of the nasal cavity is a rare entity which occurs in less than 1% among all melanomas. We present a 62 year-old-male with a polypoid mass in both sides of the nasal cavity. Histological examination revealed a lesion with large areas of ulcerations in the squamous epithelium. It was composed of diffusely scattered large atypical cells with round, spindle-shaped and irregular nuclei and scanty fibrous connective tissue with myxoid alterations in the background. Immunohistochemical study demonstrated positive staining for Melan-A, HMB-45, S-100 and negative for Cytokeratin. Ki-67 proliferation index was 85%. According to the morphological and immunohistochemical staining, it was diagnosed as malignant melanoma. No other foci have been found in the clinical evaluation. The tumor was considered as the primary malignant melanoma of the nasal cavity. Keywords: malignant, melanoma, nasal, cavity
RADICAL SURGICAL APPROACH TO A RECURRENT PERIFERAL GIANT CELL GRANULOMA: A CASE REPORT Mehmet Kemal Tumer1, Nihat Akbulut1, Emine Sebnem Kursun2, Akgül Arıcı3, Alper Sindel4, 1Department of Oral and Maxillofacial Surgery, Faculty of Dentistry,
OOOO March 2015 Gaziosmanpasa Univeristy, Tokat, Turkey; 2Department of Oral and Maxillofacial Radiology, Faculty of Dentistry, Ankara University, Ankara, Turkey; 3Department of Pathology, Faculty of Medicine, Gaziosmanpasa Univeristy, Tokat, Turkey; 4Department of Oral and Maxillofacial Surgery, Faculty of Dentistry, Akdeniz University, Antalya, Turkey Introduction: Peripheral giant cell granuloma (PGCG) is a relatively frequent benign and also the most common giant cell lesion of the oral cavity. In terms of the treatment the most important problem of these lesion is recurrence phenomena. Case: A-32- year-old female patient was referred to our surgery clinic with upper right jaw pain and also with history of several surgical giant cell lesion operations. She had no systemically any illness. We operated the patient with partial maxillectomy. We also used the frozen section procedure during the surgery. We completed the operation after taking notice from the pathologist that the surgical margins were clean. Conclusion: One of the challenging problem for surgeons is struggling with the recurrence of PGCG lesion. In our case reported above that she was operated with using several curettage methods. So, sometimes it requires radical surgical approaches that we used in this case. Keywords: benign tumor, giant cell granuloma, maxillectomy
MAXILLARY PAROSTEAL OSTEOSARCOMA: REPORT OF A CASE WITH UNUSUAL RADIOGRAPHIC APPEARANCE AND LONG-TERM FOLLOW-UP Sara Mehrabi1, Pouria Motahhary2, 1Department of Oral Pathology, Dental School, Zanjan University of Medical Sciences, Zanjan, Iran; 2Department of Oral Pathology, Dental School, Tehran University of Medical Sciences, Tehran, Iran Parosteal osteosarcoma is an uncommon malignancy of the bone that rarely affects the jaws. A 26-year-old woman presented with 6 months history of painless swelling on the left side of the maxilla in lateral incisor/canine area. Panoramic radiograph revealed no evidence of any distinct lesion of maxillary bone and teeth in that region. The lesion was treated by local excision as a peripheral tumor. Excisional biopsy microscopic examination showed a neoplastic tissue representing chondroblastic osteosarcoma, surrounded by thick capsule. After 4 months the patient returned with enlarging swelling on the same region of previous surgery. Computerized tomography revealed a soft tissue mass causing erosion of the alveolar process and anterior wall of the maxillary sinus. Segmental resection of the maxilla and adjuvant chemotherapy with reconstruction treatment was performed. The patient was under close follow-up and at present, after 2 years is free of recurrence and in a good health status. Keywords: Osteosarcoma, Bone tumor, Jaw lesion
OSTEOBLAST-DERIVED OSTEOPONTIN INCREASES THE PROLIFERATIVE RATE OF ORAL SQUAMOUS CELL CARCINOMA CELLS IN VITRO Lucas Novaes Teixeira1, Larissa Moreira Spinola De Castro Raucci2, Roger Rodrigo Fernandes3, Ricardo Della Coletta1, Adalberto Luiz Rosa3, Paulo Tambasco De Oliveira2, 1Department of Oral Diagnosis, School of Dentistry, State University of Campinas, Piracicaba, Brazil; 2Department of Morphology, Physiology and Basic Pathology, School of Dentistry of Ribeirao Preto, University of Sao Paulo, Ribeirao Preto, Brazil; 3Department