|Application:||Gene expression microarray analysis|
|Number of samples:||94|
|Release date:||Jun 10 2010|
|Last update date:||Mar 22 2012|
|Diseases:||Carcinoma, Squamous Cell, Neoplasms|
|Dataset link||Gene expression profile of recurrent and non-recurrent HNSCC|
Samples were obtained during surgery and neck dissection of 47 patients with primary untreated HNSCC at the Head and Neck Surgery Department from the Hospital AC Camargo (São Paulo, Brazil) between 1998 and 2003. Diagnosis of HNSCC was determined by biopsy. All patients signed a pre-informed consent and the study was approved by our institutional review board. After surgery, all patients were treated with adjuvant radiotherapy. Recurrence were diagnosed by imaging or biopsy. Tumor samples were snap-frozen in liquid nitrogen. Before RNA extraction, diagnosis was confirmed by hematoxylin-eosin staining. Frozen samples were hand dissected for removal of normal cells, necrosis, and infiltrating inflammatory cells. Total RNA was extracted using TRIzol. RNA quality was accessed by spectrophotometry and gel electrophoresis. To be considered as high-quality, the RNA had to have a 260/280 ratio higher than 1.7 and a 18S/28S rRNA ratio ~2. Amplifictaion of the mRNA was done using a T7-based protocol and cDNA was indirectly labeled with Alexa Dye 555 or 647. Samples and a common RNA reference were hybridized overnight at 42oC in dye-swap to a 4,800-element in-house printed microarray, enriched with cancer-related ESTs derived from the Human Cancer Genome Project. After washing, slides were scanned on a confocal laser scanner and data were extracted.