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P41 Effectiveness of selected HDAC inhibitors on head and neck squamous cell carcinoma cell lines
Abstracts / Oral Oncology 51 (2015) e27–e55
with locally advanced squamous cell carcinoma of the head and neck (HNC). Method: Blood was collected from 50 patients throughout TISOC-1 a multicenter prospective study (clinicaltrials.gov: NCT01108042) during 2009 and 2013. CTC were analyzed using CellSearch technology at five therapy intervals: Before therapy, after the first cycle of induction therapy, completion of induction, surgery and radiotherapy. Overall CTC was detected in 80% at least ones during therapy. Furthermore, during the course of therapy it was noticed that the amount of CTC declined during neoadjuvant chemotherapy as well as after radiotherapy. However, we did see an escalation of CTC quantity after surgery. doi:10.1016/j.oraloncology.2015.02.087
e55
training allele of the p53 gene is associated with mutation in conserved region. Conclusions: This novel missense mutation in the DNA binding domain indicated that the DNA structure may be damaged by the use of exogenous DNA-damaging agents, including tobacco related carcinogens present in gutka, niswar and manpuri, which may result in the loss of cellular processes and p53 protein function. doi:10.1016/j.oraloncology.2015.02.088
P41 Effectiveness of selected HDAC inhibitors on head and neck squamous cell carcinoma cell lines E. Enzenhofer, L. Kadletz, I. Stanisz, G. Heiduschka, U. Kotowski, R. Seemann, R. Schmid, D. Thurnher Vienna, Austria
P40 Aberrant epigenetic and genetic TP53 novel translational expression of codon 240 (Ser240Thr) – Association with squamous cell carcinoma of head and neck S. Saleem Karachi, Pakistan Introduction: Head and neck cancers usually begin in squamous cells that line the moist, mucosal surfaces inside the mouth, nose, and throat. These squamous cell cancers are often referred to as squamous cell carcinomas of the head and neck. Oral squamous cell carcinoma (OSCC) is the major risk factor of head and neck cancer in developing countries like Pakistan. The main cause OSCC is considered to be the excessive chewing habit of paan, chhaliya, tobacco, niswar, gutka and manpuri these days. Mutagens can damage DNA and generate promutagenic lesions. It has been reported that exon 4–9 were the hot spots of the mutation in the tumor suppressor gene. Material and methods: This study aims to find out the loss of TP53 functions due to mutation/polymorphism caused by genomic alteration and interaction with tobacco and its related ingredients in Pakistan. A total of 260 OSCC patient’s tissues and blood specimens were collected with informed consent from local hospitals of Karachi. Mutations in exons 2–11 of p53 gene were examined by polymerase chain reaction and single stranded conformational polymorphisms (PCR-SSCP) and directly sequenced. Results: The current study revealed a novel mutation in exon 7 of p53 gene. This mutation was observed only in the tumors of the OSCC patients. The ‘‘AGT’’ to ‘‘ACT’’ missense mutation was identified at position 719 at TP53. This change substitutes the amino acid serine with threonine at position 240 of p53 protein, suggesting that the
Introduction: Cancer initiation and progression is determined by various genetic and epigenetic events such as histone modification. It is a complex mechanism that results in a high turnover of alternating acetylation and deacetylation of histones. Histoneacetylases provoke chromatin decondensation whereas deacetylation causes chromatin compaction and suppression of gene transcription. The aim of this research project is to investigate the effect of the new histone deacetylase (HDAC) inhibitors resminostat and entinostat on head and neck squamous cell carcinoma cell lines and therefore maybe find a new treatment option for patients suffering from head and neck squamous cell carcinoma (HNSCC). Material and methods: SCC25, CAL27 and FaDu cells were treated with increasing doses of entinostat (0–25 lM) and resminostat (0– 25 lM) as well as in combination with increasing doses of cisplatin (0–20 lM). The cytotoxicity of entiostat, resminostat and cisplatin was determined using CCK-8 cell proliferation assay. Further, combination index analysis was performed. Cells were irradiated with 2, 4, 6 and 8 Gy. Possible synergistic effects of radiation and treatment with HDAC inhibitors were evaluated by clonogenic assays. Apoptosis was measured using FACS analysis. Results: Treatment with entinostat and resminostat showed a decreased cell proliferation of our HNSCC cell lines. Further, synergistic effects with cisplatin as well as with radiation treatment could be shown. Induction of apoptosis was present in all tested cell lines. Conclusion: Resminostat and entinostat, both new HDAC inhibitors, are promising drugs in HNSCC treatment. doi:10.1016/j.oraloncology.2015.02.089
with locally advanced squamous cell carcinoma of the head and neck (HNC). Method: Blood was collected from 50 patients throughout TISOC-1 a multicenter prospective study (clinicaltrials.gov: NCT01108042) during 2009 and 2013. CTC were analyzed using CellSearch technology at five therapy intervals: Before therapy, after the first cycle of induction therapy, completion of induction, surgery and radiotherapy. Overall CTC was detected in 80% at least ones during therapy. Furthermore, during the course of therapy it was noticed that the amount of CTC declined during neoadjuvant chemotherapy as well as after radiotherapy. However, we did see an escalation of CTC quantity after surgery. doi:10.1016/j.oraloncology.2015.02.087
e55
training allele of the p53 gene is associated with mutation in conserved region. Conclusions: This novel missense mutation in the DNA binding domain indicated that the DNA structure may be damaged by the use of exogenous DNA-damaging agents, including tobacco related carcinogens present in gutka, niswar and manpuri, which may result in the loss of cellular processes and p53 protein function. doi:10.1016/j.oraloncology.2015.02.088
P41 Effectiveness of selected HDAC inhibitors on head and neck squamous cell carcinoma cell lines E. Enzenhofer, L. Kadletz, I. Stanisz, G. Heiduschka, U. Kotowski, R. Seemann, R. Schmid, D. Thurnher Vienna, Austria
P40 Aberrant epigenetic and genetic TP53 novel translational expression of codon 240 (Ser240Thr) – Association with squamous cell carcinoma of head and neck S. Saleem Karachi, Pakistan Introduction: Head and neck cancers usually begin in squamous cells that line the moist, mucosal surfaces inside the mouth, nose, and throat. These squamous cell cancers are often referred to as squamous cell carcinomas of the head and neck. Oral squamous cell carcinoma (OSCC) is the major risk factor of head and neck cancer in developing countries like Pakistan. The main cause OSCC is considered to be the excessive chewing habit of paan, chhaliya, tobacco, niswar, gutka and manpuri these days. Mutagens can damage DNA and generate promutagenic lesions. It has been reported that exon 4–9 were the hot spots of the mutation in the tumor suppressor gene. Material and methods: This study aims to find out the loss of TP53 functions due to mutation/polymorphism caused by genomic alteration and interaction with tobacco and its related ingredients in Pakistan. A total of 260 OSCC patient’s tissues and blood specimens were collected with informed consent from local hospitals of Karachi. Mutations in exons 2–11 of p53 gene were examined by polymerase chain reaction and single stranded conformational polymorphisms (PCR-SSCP) and directly sequenced. Results: The current study revealed a novel mutation in exon 7 of p53 gene. This mutation was observed only in the tumors of the OSCC patients. The ‘‘AGT’’ to ‘‘ACT’’ missense mutation was identified at position 719 at TP53. This change substitutes the amino acid serine with threonine at position 240 of p53 protein, suggesting that the
Introduction: Cancer initiation and progression is determined by various genetic and epigenetic events such as histone modification. It is a complex mechanism that results in a high turnover of alternating acetylation and deacetylation of histones. Histoneacetylases provoke chromatin decondensation whereas deacetylation causes chromatin compaction and suppression of gene transcription. The aim of this research project is to investigate the effect of the new histone deacetylase (HDAC) inhibitors resminostat and entinostat on head and neck squamous cell carcinoma cell lines and therefore maybe find a new treatment option for patients suffering from head and neck squamous cell carcinoma (HNSCC). Material and methods: SCC25, CAL27 and FaDu cells were treated with increasing doses of entinostat (0–25 lM) and resminostat (0– 25 lM) as well as in combination with increasing doses of cisplatin (0–20 lM). The cytotoxicity of entiostat, resminostat and cisplatin was determined using CCK-8 cell proliferation assay. Further, combination index analysis was performed. Cells were irradiated with 2, 4, 6 and 8 Gy. Possible synergistic effects of radiation and treatment with HDAC inhibitors were evaluated by clonogenic assays. Apoptosis was measured using FACS analysis. Results: Treatment with entinostat and resminostat showed a decreased cell proliferation of our HNSCC cell lines. Further, synergistic effects with cisplatin as well as with radiation treatment could be shown. Induction of apoptosis was present in all tested cell lines. Conclusion: Resminostat and entinostat, both new HDAC inhibitors, are promising drugs in HNSCC treatment. doi:10.1016/j.oraloncology.2015.02.089