%0 Journal Article %T Clinical Significance of MicroRNA Expression Profiles and Polymorphisms in Lung Cancer Development and Management %A Francesca Megiorni %A Antonio Pizzuti %A Luigi Frati %J Pathology Research International %D 2011 %I Hindawi Publishing Corporation %R 10.4061/2011/780652 %X Lung cancers account for a huge percentage of death in industrialized countries, and hence there is an increasing call for the development of novel treatments. These malignancies are caused by a combination of environmental factors, principally cigarette smoking and genetic alterations. MicroRNAs (miRNAs) are a recently discovered class of regulatory noncoding small RNAs with a significance in numerous biological processes. Strong evidence links miRNA impaired expression profiles and pathways to the etiology of several diseases, including neoplasia. This paper focuses on the emerging role of miRNA function in lung cancer development with particular highlighting on the use of miRNA profiles and polymorphisms for the molecular and biological characterization of tumor pulmonary growth and progression. Furthermore, we underline the potential utility of lung cancer-associated miRNAs as clinical biomarkers with a diagnostic, prognostic, and therapeutic significance and give emphasis to the promising novel miRNA-based curative strategies. 1. Introduction Lung cancer is one of the commonest neoplasia and the first cause of death worldwide, in both women and men, with an increasing incidence rate. Less than 10% of people with the disease live longer than five years after diagnosis [1, 2]. Lung tumor is characterized by a preponderance of carcinoma derived from changes and abnormally growth of epithelial lung cells. Small cell lung carcinoma (SCLC) and non-small cell lung carcinoma (NSCLC) are two main distinct types of this neoplasia that have considerable differences in pathogenetic mechanisms, cellular origin, molecular changes and histopathological and clinical features [1]. Furthermore, they show a different response to therapeutic treatments such as surgical resection, radiation, and chemotherapy. NSCLC comprises approximately 80% of all lung cancers and can be classified into adenocarcinoma (AC), squamous cell carcinoma (SqCC), and large cell carcinoma, whereas SCLC tends to spread more quickly than NSCLC and can be divided into small cell carcinoma (SCC), mixed small cell/large cell carcinoma, and combined small cell carcinoma. Symptoms can be absent or very moderate, mainly in the early stages of tumor transformation, so that a large percentage of patients is diagnosed only in advanced stage of tumor extension with a consequent poor treatment outcome. Although surgery provides a potential curative strategy, patients often develop recurrence with a survival rate that remains very low especially in subjects with metastatic disease. Therefore, looking for %U http://www.hindawi.com/journals/pri/2011/780652/