Hospital-based epidemiological and clinical characterisation of the malignant transformation of oral leukoplakia in a Chinese population.

OBJECTIVE: The aim of this review was to analyse, systematically, hospital-based epidemiological information concerning the malignant transformation rate (MTR) of oral leukoplakia (OL) in a Chinese population, as well as the associated risk factors. METHODS: Four electronic databases were searched for studies dealing with OL and related risk factors, including age, gender, type of lesion, site, and smoking and drinking habits. RESULTS: The MTR of OL in the hospital-based Chinese population ranged from 4% to 13%, based on the studies analysed. Regarding risk factors, we found that female patients had a higher MTR than male patients, and that patients older than 50 years of age also had a higher MTR. Patients who smoked had a lower MTR, while alcohol consumption seemed to have no association with MTR. Malignant transformation occurred most commonly on the tongue. Regarding lesion type, non-homogeneous OL had a higher MTR, with the granular type having the highest MTR. Our results regarding the epidemiology of OL showed a similar trend to those reported in western populations and provided preliminary epidemiological information on the Chinese population. CONCLUSIONS: Our findings show that female gender, age >50 years and non-homogeneous OL are risk factors for malignant transformation. It is important to develop clinical strategies to educate, diagnose and treat patients with OL and to minimise the MTR of OL.

miR-29b suppresses proliferation, migration, and invasion of tongue squamous cell carcinoma through PTEN-AKT signaling pathway by targeting Sp1.

OBJECTIVES: miR-29b has been implicated in various cancers. However, the role of miR-29b in tongue squamous cell carcinoma (TSCC) remains unclear. This study aimed to investigate the role of miR-29b in TSCC progression. MATERIALS AND METHODS: The expression of miR-29b was analyzed in TSCC tissues and cells. Functional studies were performed in TSCC cells. Real time-PCR, Western blot, cell proliferation, transwell, and dual luciferase reporter assays were performed according to standard procedures. RESULTS: miR-29b was significantly decreased in TSCC specimens and cell lines compared with corresponding normal counterparts. Overexpression of miR-29b significantly inhibited the proliferation, migration, invasion, and cell-cycle progression of TSCC cells, and promoted apoptosis. Moreover, miR-29b targeted the 3' untranslated region of the Sp1 transcript and resulted in the deregulation of Sp1. The inhibition of Sp1 by miR-29b subsequently resulted in the upregulation of PTEN, leading to a decline of phosphorylated AKT. Knockdown of Sp1 in TSCC cell lines mimicked the effects of miR-29b overexpression. In addition, the expression of miR-29b was inversely correlated with Sp1 and positively correlated with the PTEN in TSCC specimens. CONCLUSION: miR-29b functions as a tumor suppressor in TSCC, and the miR-29b/Sp1/PTEN/AKT axis might represent a potential therapeutic target for TSCC intervention.