Accuracy of microRNAs as markers for the detection of neck lymph node metastases in patients with head and neck squamous cell carcinoma

Background: the presence of metastatic disease in cervical lymph nodes of head and neck squamous cell carcinoma (HNSCC) patients is a very important determinant in therapy choice and prognosis, with great impact in overall survival. Frequently, routine lymph node staging cannot detect occult metastases and the post-surgical histologic evaluation of resected lymph nodes is not sensitive in detecting small metastatic deposits. Molecular markers based on tissue-specific microRNA expression are alternative accurate diagnostic markers. Herein, we evaluated the feasibility of using the expression of microRNAs to detect metastatic cells in formalin-fixed paraffin-embedded (FFPE) lymph nodes and in fine-needle aspiration (FNA) biopsies of HNSCC patients.Methods: An initial screening compared the expression of 667 microRNAs in a discovery set comprised by metastatic and non-metastatic lymph nodes from HNSCC patients. the most differentially expressed microRNAs were validated by qRT-PCR in two independent cohorts: i) 48 FFPE lymph node samples, and ii) 113 FNA lymph node biopsies. the accuracy of the markers in identifying metastatic samples was assessed through the analysis of sensitivity, specificity, accuracy, negative predictive value, positive predictive value, and area under the curve values.Results: Seven microRNAs highly expressed in metastatic lymph nodes from the discovery set were validated in FFPE lymph node samples. MiR-203 and miR-205 identified all metastatic samples, regardless of the size of the metastatic deposit. Additionally, these markers also showed high accuracy when FNA samples were examined.Conclusions: the high accuracy of miR-203 and miR-205 warrant these microRNAs as diagnostic markers of neck metastases in HNSCC. These can be evaluated in entire lymph nodes and in FNA biopsies collected at different time-points such as pre-treatment samples, intraoperative sentinel node biopsy, and during patient follow-up. These markers can be useful in a clinical setting in the management of HNSCC patients from initial disease staging and therapy planning to patient surveillance.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Universidade Federal de São Paulo, Dept Biol Sci, Lab Canc Mol Biol, BR-04039032 São Paulo, SP, BrazilBarretos Canc Hosp, Mol Oncol Res Ctr, BR-14784400 Barretos, SP, BrazilBarretos Canc Hosp, Dept Pathol, BR-14784400 Barretos, SP, BrazilBarretos Canc Hosp, Dept Head & Neck Surg, BR-14784400 Barretos, SP, BrazilDuke NUS Grad Med Sch, Canc Stem Cell Biol Program, Singapore 169857, SingaporeUniversidade Federal de São Paulo, Dept Biol Sci, Lab Canc Mol Biol, BR-04039032 São Paulo, SP, BrazilFAPESP: 2012/14837-7Web of Scienc

Phospholipase gene expression during Paracoccidioides brasiliensis morphological transition and infection

Phospholipase is an important virulence factor for pathogenic fungi. In this study, we demonstrate the following: (i) the Paracoccidioides brasiliensis pld gene is preferentially expressed in mycelium cells, (ii) the plb1 gene is mostly up-regulated by infection after 6 h of co-infection of MH-S cells or during BALB/c mice lung infection, (iii) during lung infection, plb1, plc and pld gene expression are significantly increased 6-48 h post-infection compared to 56 days after infection, strongly suggesting that phospholipases play a role in the early events of infection, but not during the chronic stages of pulmonary infection by P. brasiliensis

Gene Expression Profiles Stratified according to Type 1 Diabetes Mellitus Susceptibility Regions

The MHC region (6p21) aggregates the major genes that contribute to susceptibility to type 1 diabetes (T1D). Three additional relevant susceptibility regions mapped on chromosomes 1p13 (PTPN22), 2q33 (CTLA-4), and 11p15 (insulin) have also been described by linkage studies. To evaluate the contribution of these susceptibility regions and the chromosomes that house these regions, we performed a large-scale differential gene expression on lymphomononuclear cells of recently diagnosed T1D patients, pinpointing relevant modulated genes clustered in these regions and their respective chromosomes. A total of 4608 cDNAs from the IMAGE library were spotted onto glass slides using robotic technology. Statistical analysis was carried out using the SAM program, and data regarding gene location and biological function were obtained at the SOURCE, NCBI, and FATIGO programs. Three induced genes were observed spanning around the MHC region (6p21-6p23), and seven modulated genes (5 repressed and 2 repressed) were seen spanning around the 6q21-24 region. Additional modulated genes were observed in and around the 1p13, 2q33, and 11p15 regions. Overall, modulated genes in these regions were primarily associated with cellular metabolism, transcription factors and signaling transduction. The differential gene expression characterization may identify new genes potentially involved with diabetes pathogenesis.Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq