• Asian Pacific Journal of Cancer Prevention
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• v.16 no.4
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• pp.1599-1603
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• 2015

Background: Epigenetic silencing of tumor suppressor genes due to promoter hypermethylation is one of the frequent mechanisms observed in cancers. Hypermethylation of several tumor suppressor genes involved in cell cycle regulation has been reported in many types of tumors including oral squamous cell carcinomas. LATS1 (Large Tumor Suppressor, isoform 1) is a novel tumor suppressor gene that regulates cell cycle progression by forming complexes with the cyclin dependent kinase, CDK1. Promoter hypermethylation of the LATS1 gene has been observed in several carcinomas and also has been linked with prognosis. However, the methylation status of LATS1 in oral squamous cell carcinomas is not known. As oral cancer is one of the most prevalent forms of cancer in India, the present study was designed to investigate the methylation status of LATS1 promoter and associate it with histopathological findings in order to determine any associations of the genetic status with stage of differentiation. Materials and Methods: Tumor chromosomal DNA isolated from biopsy tissues of thirteen oral squamous cell carcinoma biopsy tissues were subjected to digestion with methylation sensitive HpaII enzyme followed by amplification with primers flanking CCGG motifs in promoter region of LATS1 gene. The PCR amplicons were subsequently subjected to agarose gel electrophoresis along with undigested amplification control. Results: HpaII enzyme based methylation sensitive PCR identified LATS1 promoter hypermethylation in seven out of thirteen oral squamous cell carcinoma samples. Conclusions: The identification of LATS1 promoter hypermethylation in seven oral squamous cell carcinoma samples (54%), which included one sample with epithelial dysplasia, two early invasive and one moderately differentiated lesions indicates that the hypermethylation of this gene may be one of the early event during carcinogenesis. To the best of our knowledge, this is the first study to have explored and identified positive association between LATS1 promoter hypermethylation with histopathological features in oral squamous cell carcinomas.

• Asian Pacific Journal of Cancer Prevention
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• v.17 no.12
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• pp.5243-5245
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• 2016

Background and Objective : Bone morphogenic protein-2 (BMP-2) plays an essential role in mesenchymal cell differentiation into osteoblasts، through many intracellular pathways which may also be active in tumors. Invasive oral squamous cell carcinomas account for more than 90% of head and neck malignancies in many cancer registries. They are classified into three types according to epithelial cell differentiation. The present study aimed to identify any relation between BMP-2 expression and tumor histology. Materials and methods: BMP-2 expression was compared immunohistochemically among 30 cases (19 male and 11 female, mean age 48 years) of oral squamous cell carcinoma, Division was into 3 groups (each containing 10 cases) according to the histological grade. Results: No significant correlation between BMP-2 expression and histological grade was observed. Changes in localization and cytoplasmic staining were also not apparent. Conclusion: From the results of this study BMP-2 does not appear to have any application as a prognostic marker for oral squamous cell carcinomas.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.4
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• pp.1615-1619
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• 2015

Background: Promoter hypermethylation mediated gene silencing of tumor suppressor genes is considered as most frequent mechanism than genetic aberrations such as mutations in the development of cancers. BRD7 is a single bromodomain containing protein that functions as a subunit of SWI/SNF chromatin-remodeling complex to regulate transcription. It also interacts with the well know tumor suppressor protein p53 to trans-activate genes involved in cell cycle arrest. Loss of expression of BRD7 has been observed in breast cancers and nasopharyngeal carcinomas due to promoter hypermethylation. However, the genetic status of BRD7 in oral squamous cell carcinomas (OSCCs) is not known, although OSCC is one of the most common among all reported cancers in the Indian population. Hence, in the present study we investigated OSCC samples to determine the occurrence of hypermethylation in the promoter region of BRD7 and understand its prevalence. Materials and Methods: Genomic DNA extracted from biopsy tissues of twenty three oral squamous cell carcinomas were digested with methylation sensitive HpaII type2 restriction enzyme that recognizes and cuts unmethylated CCGG motifs. The digested DNA samples were amplified with primers flanking the CCGG motifs in promoter region of BRD7 gene. The PCR amplified products were analyzed by agarose gel electrophoresis along with undigested amplification control. Results: Methylation sensitive enzyme technique identified methylation of BRD7 promoter region seventeen out of twenty three (74%) well differentiated oral squamous cell carcinoma samples. Conclusions: The identification of BRD7 promoter hypermethylation in 74% of well differentiated oral squamous cell carcinomas indicates that the methylation dependent silencing of BRD7 gene is a frequent event in carcinogenesis. To the best of our knowledge, the present study is the first to report the occurrence of BRD7and its high prevalence in oral squamous cell carcinomas.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.2
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• pp.1147-1150
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• 2013

Background: Cancer diagnostic biomarkers have a wide range of applications that include early detection of oral precancerous lesions and oral squamous cell carcinomas, and assessing the metastatic status of lesions. The interferon stimulated ISG15 gene encodes an ubiquitin-like protein, which conjugates to stabilize activation status of associated proteins. Hence a deregulated expression of ISG15 may promote carcinogenesis. Indeed overexpression of ISG15 has been observed in several cancers and hence it has been proposed as a strong candidate cancer diagnostic biomarker. Given the emerging relationship between malignant transformation and ISG15, we sought to examine the expression pattern of this gene in tumor biopsies of oral squamous cell carcinoma (OSCC) tissues collected from Indian patients. Materials and Methods: Total RNA isolated from thirty oral squamous cell carcinoma tissue biopsy samples were subjected to semi-quantitative RT-PCR with ISG15 specific primers to elucidate the expression level. Results: Of the thirty oral squamous cell carcinomas that were analyzed, ISG15 expression was found in twenty four samples (80%). Twelve samples expressed low level of ISG15, six of them expressed moderately, while the rest of them expressed very high level of ISG15. Conclusions: To the best of our knowledge, the results show for the first time an overexpression of ISG15 in up to 80% of oral squamous cell carcinoma tissues collected from Indian patients. Hence ISG15 may be explored for the possibility of use as a high confidence diagnostic biomarker in oral cancers.

• International Journal of Oral Biology
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• v.31 no.2
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• pp.27-32
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• 2006

Expression of invasion/metastasis suppressor, E-cadherin, is reduced in many types of human carcinomas. Although somatic and germline mutations in the CDH1, which encodes the human E-cadherin, have frequently been reported in cases with diffuse gastric and lobular breast cancers, irreversible genetic inactivations are rare in other human carcinomas. Recently, it has been well documented that some genes in human cancers may be inactivated by altered CpG methylation. Herein, we determined the expression and methylation status of E-cadherin in oral squamous cell carcinoma(SCC) by immunohistochemistry and methylation-specific PCR. The expression of E-cadherin was significantly higher in the well-differentiated oral SCCs than the moderately or poorly differentiated ones. None of eight tested benign epithelial hyperplasias showed aberrant methylation, whereas five of 12 oral squamous cell carcinomas showed aberrant methylation. When we compared E-cadherin expression with methylation status, oral SCCs with normal methylation showed a higher expression of E-cadherin than those with methylation. These findings suggest that aberrant CpG methylation of CDH1 promoter region is closely associated with transcriptional inactivation and might be involved in tumor progression of the oral mucosa.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.26 no.2
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• pp.154-163
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• 2000

Growth factors and the receptors play an important role in the regulation of the growth and development of mammalian cells. In particular, epidermal growth factor is a polypeptide with potent mitogenic activity that stimulates proliferation of various normal and neoplastic cells through the interaction with its specific receptor(EGFR). EGFR has been described as a parameter of poor prognosis in many human neoplasms such as breast, bladder, and vulvar cancers. The objectives of this study are the evaluation of the expression of EGFR and cell cycle analysis in the head and neck squamous cell carcinomas(SCC), and the evaluation of the correlation between clinico-patholgic features and expression of EGFR and S-phase fraction. 37 head and neck squamous cell carcinoma specimens were evaluated for expression of EGFR by Western blot analysis and S-phase fraction by cell cycle analysis using the flow cytometry. The obtained results were as follows : 1. The expressions of EGFR were observed in 20 specimens(54%) among 37 head and neck SCC specimens. In case of oral SCC, 15 specimens(56%) out of 27 specimens were observed, and in case of nasopharyngeal SCC 5 specimens(50%) out of 10 specimens. 2. There was no correlation between clinical features(location, stage) of head and neck SCC and expression of EGFR (p>0.05). 3. There was a significant correlation between histo-pathological differentiation of head and neck SCC and expression of EGFR (p<0.02). 4. There was a significant correlation between expression of EGFR and S-phase fraction of cell cycle in the head and neck SCC (p<0.05). The above results suggest that expression of EGFR and S-phase fraction of cell cycle are adjunctive prognostic marker in the head and neck squamous cell carcinomas.

• Korean Journal of Head & Neck Oncology
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• v.32 no.2
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• pp.73-77
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• 2016

Simultaneous second primary tumors are not uncommon in patients with oral cavity squamous cell carcinoma. Many studies have previously shown that oral cavity squamous cell carcinoma patients with simultaneous second primary tumor generally have a poor prognosis. Additionally, the choice of the optimal therapeutic modality for oral cavity squamous cell carcinoma patients who present with simultaneous second primary tumor remains problematic. We reported a case of simultaneous squamous cell carcinomas in mouth floor and esophagus, that multidisciplinary team performed resection and reconstruction simultaneously.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.29 no.5
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• pp.394-404
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• 2007

Oral squamous cell carcinoma is the most prevalent oral cancer, which is characterized by its high metastasis and recurrent rates and poor prognosis. Taxol is an anticancer agent which is microbial products extracted from jew tree. It combines with the tubulin and induces apoptosis by inhibiting mitosis of cell with microtubule stabilization. Recently, it was reported to be effective in various solid tumors, but only very slight effect has been seen in oral squamous cell carcinomas due to its cell-specific potencies. Cyclosporin A is used as immune suppressant and is being applied in anticancer therapy as its mechanism of induction of change of apoptotic process in various cells have been known. In this study, oral squamous cell carcinoma HN22 cell line was used for in vitro experiment and as for the experimental group taxol and cyclosporin A were applied alone and to observe the synergistic effect of apoptosis, Taxol and cyclosporin A were coadministered with different concentration of taxol for comparison. The results were obtained as follow: 1. There was no difference in Bcl-2, Bax, caspase 3, 8, 9 mRNA expression when cyclosprin A or taxol was applied alone to HN 22 cell line. 2. Caspase 3, 9 mRNA expression was prominently increased when cyclosprin A and taxol were applied together to cancer cell. 3. No significant difference was observed when cyclosporin A and taxol($1{\mu}g/ml$ and $3{\mu}g/ml$) were applied together to cancer cell line. 4. No significant difference was seen in Bcl-2, Bax, and caspase 8 mRNA expression in all the groups of in vitro experiments. 5. When cyclosporin A was applied alone in vivo study on the nude mice, histopathologi cal findings was similar to those of the control group. Oral squamous cell carcinoma induced by inoculation of HN 22 cell line was not reduced after treatment of cyclosporin A. 6. When taxol was applied alone, the islands of squamous cell carcinoma still remained, which meant insignificant healing effect. There was a lesser volume increase compared with the cyclosporin A alone. 7. When taxol and cyclosporin A were applied together, the connective tissue and calcification were seen in the histopathologic findings. Oral squamous cell carcinoma was decreased and cancer cell was disappeared. In observing the tumor mass change with time, there was a gradual decreased size and healing features. As the results of the in vitro experiment, it could conclud that only when the two agents are applied together, mitochondria-mediated apoptosis occurred by considerable increase of caspase 3, 9 mRNA expression, irrespectable of the concentration of taxol. In vivo experiment, there was a discrete synergistic effect when the two agents were applied together. But single use of cyclosporin A was not effective in this study. Based on the results of this experiment, if further clinical studies are done, taxol and cyclosporin A could be effectively used in treatment of oral squamous cell carcinomas.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.3
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• pp.975-978
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• 2012

P63 is a gene product required in cell cycle regulation which plays vital roles in tumor differentiation. Aims of the present study were to assess the frequency, pattern, sensitivity and specificity of two p63 protein clones P63 4A4 and P63 4A4+Y4A3 in squamous cell carcinomas (SCCs). Thirty cases of head and neck region SCC diagnosed on the basis of H&E staining were examined along with 60 cases of head and neck region biopsies other than squamous cell carcinoma, negative on H&E staining, were taken as control. Immunostaining was performed on slides according to the Thermo Scientific UltraVision LP detection System. P63 4A4+Y4A3 clone is more sensitive 96.6% in comparison to 86% in P63 4A4 with having greater NPV of 98.3%. The results signify the importance of P63 4A4+Y4A3 marker over the old markers and may be used as a confirmatory marker of squamous cell carcinoma.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.7
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• pp.4279-4282
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• 2013

Background: The activation and inactivation of receptor tyrosine kinases are tightly regulated to ensure faithful replication of cells. After having transduced extracellular growth activating signals, activated EGFR is subjected to downregulation either by clathrin mediated endocytosis or c-Cbl mediated proteasome degradation depending on the ligand concentration. c-Cbl is an ubiquitin ligase which requires a phosphorylated tyrosine residue at position 1045 in the cytoplasmic domain of EGFR to interact and add ubiquitin molecules. While activating mutations in exons 19 and 21 have been associated with the development of several cancers, the status of mutations at tyrosine 1045 coding exon 27 of EGFR remain to be investigated. Consistently, defective phosphorylation at 1045 has been associated with sustained phosphorylation of EGFR in non-small lung carcinomas. Hence in the present study we investigated the genetic status of the tyrosine 1045 coding site within exon 27 of EGFR gene to explore for possible occurrence of mutations in this region, especially since no studies have addressed this issue so far. Materials and Methods: Tumor chromosomal DNA isolated from thirty five surgically excised oral squamous cell carcinoma tissues was subjected to PCR amplification with intronic primers flanking the tyrosine 1045 coding exon 27 of EGFR gene. The PCR amplicons were subsequently subjected to direct sequencing to elucidate the mutation status. Results: Sequence analysis identified no mutations in the tyrosine 1045 codon of EGFR in any of the thirty five samples that were analyzed. Conclusions: The lack of identification of mutation in the tyrosine 1045 codon of EGFR suggests that mutations in this region may be relatively rare in oral squamous cell carcinomas. To the best of our knowledge, this study is the first to have explored the genetic status of exon 27 of EGFR in oral squamous cell carcinoma tissue samples.