Silencing SATB1 with siRNA inhibits the proliferation and invasion of small cell lung cancer cells

The level of SATB1 was analyzed in SCLC tissues, metastatic lymphoid nodes and adjacent normal lung tissues by immunohistochemistry. Meanwhile, small interfering SATB1-targeting RNA was constructed and transfected into human SCLC cell line NCI-H446 to evaluate the effects of SATB1-siRNA on cell proliferation, invasion and apoptosis.SATB1 protein was overexpressed in SCLC tissues and metastasis lymphoid nodes compared with adjacent normal lung tissues. Compared with control group, SATB1-siRNA inhibits the proliferation and invasion of SCLC cells and induces SCLC cells apoptosis statistically (P<0.05) in vitro.Our results suggest that SATB1 plays an important role in the metastasis of human SCLC cell.Small cell lung cancer (SCLC) is a special kind of lung cancer, which comprises 15%-20% of all lung cancers. Different from other lung cancers, SCLC exhibits aggressive behavior with rapid growth and spread to distant sites early [1]. Although SCLC is exquisite sensitivity to chemotherapy and radiation, it is more prone to relapse and recurrence. Special AT-rich sequence binding protein 1 (SATB1) is a nuclear matrix attachment region binding protein (MBP) which participates in higher-order chromatin organization and tissue-specific gene expression [2,3]. SATB1 play an important role in differentiation, and expresses at high level in thymocyte, its expression is down-regulated in mature T cells [4,5]. SATB1 has been reported to promote a metastatic phenotype and correlate with poor prognosis in breast cancer [6]. Its expression has also been associated with unfavourable clinicopathological characteristics and poor prognosis in gastric, liver and colorectal cancer and glioma [7-12]. RNA-interference-mediated knockdown in aggressive cancer cells have altered the expression of over 1,000 genes, this technique effectively inhibited cell capacity of proliferation, invasion, tumor growth and metastasis [6]. Zheng et al. also found SATB1 expression in aggressive rather than non-a