Oral squamous cell carcinoma, the most frequently occurring malignant head and neck tumour, generally exhibits poor prognosis and metastases are the main cause of death. The discovery of reliable prognostic indicators of tumour progression could greatly improve clinical practice. MicroRNAs are involved in the regulation of basic cellular processes such as cell proliferation, differentiation, and apoptosis. Since miRNAs have been shown to be abnormally expressed in different tumours their importance as potential cancer prognostic indicators is increasing. To define the role of miRNA in OSCC tumours we investigated the expression profile of 15 OSCC (8 without metastasis and 7 with lymph node metastasis) using microarray analysis. Thirteen miRNA were significantly overexpressed (miR-489, miR-129, miR-23a, miR-214, miR-23b, miR-92, miR-25, miR-210, miR-212, miR-515, miR-146b, miR-21, miR-338) and 6 miRNA were underexpressed (miR-520h, miR-197, miR-378, miR-135b, miR-224, miR-34a) in oral tumours. Underexpression of mir-155, let-7i, mir-146a was found to characterize progression to metastastatic tumours. Further investigations will elucidate whether differentially expressed miRNAs will help to better classify OSCCs, thus improving diagnoses and patient care.

Nonsyndromic cleft of the lip and/or palate (CLP or orofacial cleft) derives from an embryopathy with consequent failure of the nasal process and/or palatal shelves fusion. This severe birth defect is one of the most common malformations among live births. Nonsyndromic CLP is composed of two separate entities: cleft lip and palate (CL±P) and cleft palate only (CPO). Both have a genetic background, and environmental factors probably disclose these malformations. In CL±P, several loci have been identified, and, in one case, a specific gene has also been found. In CPO, one gene has been identified, but many more are probably involved. Because of the complexity of the genetics of nonsyndromic CLP as a result of the difference between CL±P and CPO, heterogeneity of each group caused by the number of involved genes, type of inheritance, and interaction with environmental factors, we discuss the more sound results obtained with different approaches: epidemiological studies, animal models, human genetic studies, and in vitro studies.