Lung cancer may be a result of complex factors. Small
mineral particle is the well-known inducer of
lung cancer. Previous study revealed the high morbidity of
lung cancer in Xuan Wei in China, and the main cause of
lung cancer is the use of smoky
coal there. And it is generally accepted that chronic
inflammation induced by small
mineral particle may be a cause of
lung cancer. But the relationship between chronic
lung inflammation and
lung cancer is largely unknown. In the present study, we found that
silica particle was able to induce the secretion of interleukin-1β from a Xuan Wei
lung cancer cell line, XWLC-05. At the same time, microRNA-101 (mir-101) was found to be downregulated by the treatment of
silica particle. Interestingly, the
interleukin 1 receptor antagonist and interleukin-1β antibody can reduce
silica particle-induced downregulation of mir-101. Twenty-four Xuan Wei lung
tumor tissues were collected to detect the expression level of mir-101 and
enhancer of zeste homolog 2 (EZH2), which is the potential target of mir-101. The results showed that mir-101 was down-regulated and EZH2 were upregulated. Subsequently, the roles of mir-101 and EZH2 in
tumor growth and progression in vitro were tested. Overexpression of mir-101 mimics was able to suppress the expression of EZH2 in XWLC-05 cells. And this resulted in the inhibited
tumor cell growth and attenuated cell migration. The results in the present study showed that particle can induce the secretion of interleukin-1β. Interleukin-1β subsequently induces the downregulation of mir-101, which may result in the upregulated level of EZH2, and occurrence of
lung cancer. We for the first time proposed the role interleukin-1β-mir-101-EZH2 axes in the particle-induced
lung cancer. Further study may be needed to decipher the detailed mechanism involved.