Different expression patterns of pAkt, NF-κB and cyclin D1 proteins during the invasion process of head and neck squamous cell carcinoma: an in vitro approach.

BACKGROUND: Several signaling pathways are involved in the progression of squamous cell carcinoma. Among them, activated PI3K/Akt may result in NF-κB nuclear translocation, thus leading to the transcription of genes enrolled in cellular invasion and proliferation, such as cyclin D1. This study sought to evaluate the expression of pAkt, NF-κB and cyclin D1 proteins in head and neck squamous cell carcinoma cell lines and their respective in vitro-obtained invasive clones. METHODS: Squamous cell carcinoma cell lines originating from the tongue, pharynx and the metastatic lymph node were submitted to an in vitro invasion assay to select invasive clones. All experimental groups were submitted to immunofluorescence and Western blot assays. Statistical analysis was performed through a Student's t-test with a significance level of 5%. RESULTS: The pAkt and NF-κB expression differed from cytoplasm and nucleus depending on the studied cell line. The invasive clone from the tongue presented a network-like structure of pAkt's cytoplasmic expression. This lineage as well as the invasive clone from pharynx also showed pAkt and NF-κB nuclear transportation. Significant pAkt and NF-κB increases were observed in the tongue and pharynx invasive clones. Cyclin D1 was detected in the nucleus of all studied cells and was significantly enhanced in the invasive clones from tongue and pharynx. CONCLUSION: This study suggests the participation of pAkt, NF-κB and cyclin D1 in the invasion process of head and neck squamous cell carcinoma. Moreover, cytoplasmic pAkt network-like structure was probably related to cytoskeleton changes presented during invasion.

Expression of cancer testis antigens in head and neck squamous cell carcinomas.

BACKGROUND: There is considerable interest in the expression of cancer testis (CT) antigens in human cancers, because they may serve as the basis for diagnostic tests or an immunologic approach to therapy, or as prognostic markers. METHODS: On this basis, we evaluated by semiquantitative reverse-transcriptase polymerase chain reaction (RT-PCR) the expression of genes that code for tumor antigens (melanoma antigen-1 [MAGE-1], MAGE-4, MAGE-10, MAGE-12, B melanoma antigen, CTL-recognized antigen melanoma antigen (CT antigen 2) [LAGE], New York esophageal squamous cell carcinoma antigen (CT antigen 1) [NYESO-1], and preferentially expressed antigen of melanoma [PRAME]) in surgical samples of the tumors, margins, and lymph nodes (when present) from patients with a diagnosis of head and neck carcinoma. The study was conducted on 33 patients (31 men and two women), aged 31 to 94 years (mean, 56 years), with squamous cell carcinomas located in the mouth (15 cases), larynx (14 cases), and pharynx (four cases). RESULTS: The findings were compared with the clinical course and laboratory data. Expression of at least one antigen was observed in 66.6% of cases, with different rates of expression according to tumor staging (100% of T4, 57% of T3, 50% of T1 and T2) and smoking habit. There was a significantly higher expression of multiple genes (two or more) in tumors in advanced stages. CONCLUSIONS: We conclude that the tumor-specific antigen genes are expressed in variable frequencies and intensities in the primary lesions of head and neck squamous cell carcinomas and in their metastases, with expression of the PRAME gene being always present in the metastastatic lymph nodes. In primary lesions, gene expression correlated with smoking habit and with advanced tumors with a higher malignant potential, with the frequent expression of two or more of these genes.