Clinical roles of autophagy-related proteins Beclin-1 and mTOR in smoking and non-smoking patients with oral leukoplakia.

BACKGROUND

To study the expressions of autophagy-related proteins Beclin-1 and mammalian target of rapamycin (mTOR) in smoking and non-smoking patients with oral leukoplakia (OLK).

METHODS

A total of 240 patients diagnosed as OLK from January 2017 to December 2017 were enrolled. Beclin-1 and mTOR expressions were detected by immunohistochemistry. Their clinical data were collected. The correlations of smoking with Beclin-1 and mTOR expressions as well as clinical factors were explored by Spearman's analysis.

RESULTS

There were significant differences in gender ratio, age, lesion location, severity and malignancy between smoking and non-smoking OLK patients (P<0.05). The positive expression rate of Beclin-1 in OLK patients with simple hyperplasia and abnormal hyperplasia in the smoking group was significantly lower than that of the non-smoking group (P<0.05). In the abnormal hyperplasia group, the number of cigarettes daily was significantly positively correlated with mTOR expression (=0.843, P=0.042). After the simple hyperplasia group was included, there was a positive correlation between smoking age and positive expression rate of mTOR (=0.942, P=0.012). For number of cigarettes and smoking age, the positive expression rates of Beclin-1 and mTOR showed significant negative correlations (=-0.952, P=0.003, =-0.953, P=0.002).

CONCLUSION

Autophagy-related proteins Beclin-1 and mTOR may be involved in the smoking-induced pathogenesis of OLK.