RESUMO
OBJECTIVE: PI3K/Akt signalling pathway is frequently activated in several types of cancer. However, activator molecules have not been analysed systematically in HNSCC. The aim of this study was to investigate upstream activators and inhibitors of this pathway. DESIGN: Prospective study. SETTING: University hospital. PARTICIPANTS: 108 patients with HNC who were operated at the Istanbul University, Cerrahpasa Medical Faculty, Department of Otorhinolaryngology. METHODS: Mutations in the coding exons and the flanking intronic sequences of the PIK3CA, PIK3R1 and AKT1 genes were analysed by direct sequencing. Expression levels in the tumours and non-cancerous tissue samples were analysed by quantitative RT-PCR, and Western blotting was performed to determine the phosphorylation levels of the Akt1 protein. RESULTS: Two synonymous alterations in exon 20 of the PIK3CA gene, a 6-bp duplication in the coding region of the PIK3R1 and two different alterations in the non-coding regions of the AKT1 and PIK3R1 genes were observed. Significant downregulation of LKB1 and PTEN mRNA expression levels were detected in tumour tissues compared to non-cancerous tissues. However, we did not observe any difference between the PIK3CA and AKT1 mRNA expression levels in the tumours and non-cancerous tissue samples. Akt1 phosphorylation was increased in 53.57% of the patients. CONCLUSIONS: Our results indicate that the PI3K pathway has an important function in HNSCC progression with the contribution of more than one gene of this pathway. Our data suggest that in a high number of HNSCC tumours, PI3K/Akt signalling is activated by different molecules or by the combination of these molecules.
Assuntos
Carcinoma de Células Escamosas/genética , Regulação Neoplásica da Expressão Gênica , Neoplasias de Cabeça e Pescoço/genética , PTEN Fosfo-Hidrolase/genética , Fosfatidilinositol 3-Quinases/genética , Proteínas Serina-Treonina Quinases/genética , Proteínas Proto-Oncogênicas c-akt/genética , RNA Neoplásico/genética , Quinases Proteína-Quinases Ativadas por AMP , Adulto , Idoso , Western Blotting , Carcinoma de Células Escamosas/metabolismo , Carcinoma de Células Escamosas/patologia , Classe I de Fosfatidilinositol 3-Quinases , Feminino , Neoplasias de Cabeça e Pescoço/metabolismo , Neoplasias de Cabeça e Pescoço/patologia , Humanos , Masculino , Pessoa de Meia-Idade , PTEN Fosfo-Hidrolase/biossíntese , Fosfatidilinositol 3-Quinases/biossíntese , Estudos Prospectivos , Proteínas Serina-Treonina Quinases/biossíntese , Proteínas Proto-Oncogênicas c-akt/biossíntese , Reação em Cadeia da Polimerase em Tempo Real , Transdução de Sinais , Carcinoma de Células Escamosas de Cabeça e PescoçoRESUMO
In this study, different ultrasound power intensities (0.1-0.5 W mL(-1)) were applied at a frequency of 30 kHz and for durations of 5-60 min to mixed microalgal cultures, one cultivated in BG11 medium, and the other in secondary effluent wastewater. The ultrasonic effect on cell disruption was revealed by increased concentrations of protein and carbohydrate released into the solution, and a decreased concentration of total suspended solids in cell suspension. The highest intercellular material release was achieved at an ultrasonic energy intensity of 0.4 kWh L(-1), while the effect of ultrasound on cell disruption was reduced at higher energy intensities. Additionally, the ultrasonic effect on lipid extraction efficiency was studied in the presence of two different solvents, n-hexane and chloroform/methanol mixture. The application of ultrasound at 0.4 kWh L(-1), provided 1.5-2.0-fold increase in lipid extraction yields in the presence of the solvents.