Lingling Zu

MiR-132 suppresses the migration and invasion of lung cancer cells via targeting the EMT regulator ZEB2.

MicroRNAs (miRNAs) are small, non-coding RNAs which can function as oncogenes or tumor suppressor genes in human cancers. Emerging evidence reveals that deregulation of miRNAs contributes to the human non-small cell lung cancer (NSCLC). In the present study, we demonstrated that the expression levels of miR-132 were dramatically decreased in examined NSCLC cell lines and clinical NSCLC tissue samples. Then, we found that introduction of miR-132 significantly suppressed the migration and invasion of lung cancer cells in vitro, suggesting that miR-132 may be a novel tumor suppressor. Further studies indicated that the EMT-related transcription factor ZEB2 was one direct target genes of miR-132, evidenced by the direct binding of miR-132 with the 3′ untranslated region (3′ UTR) of ZEB2. Further, miR-132 could decrease the expression of ZEB2 at the levels of mRNA and protein. Notably, the EMT marker E-cadherin or vimentin, a downstream of ZEB2, was also down-regulated or up-regulated upon miR-132 treatment. Additionally, over-expressing or silencing ZEB2 was able to elevate or inhibit the migration and invasion of lung cancer cells, parallel to the effect of miR-132 on the lung cancer cells. Meanwhile, knockdown of ZEB2 reversed the enhanced migration and invasion mediated by anti-miR-132. These results indicate that miR-132 suppresses the migration and invasion of NSCLC cells through targeting ZEB2 involving the EMT process. Thus, our finding provides new insight into the mechanism of NSCLC progression. Therapeutically, miR-132 may serve as a potential target in the treatment of human lung cancer.

MicroRNA-449a inhibits cell growth in lung cancer and regulates long noncoding RNA nuclear enriched abundant transcript 1

OBJECTIVE Lung cancer has become the primary cause of cancer-related death now. New therapies targeting the molecular regulatory machinery were required imperatively. MicroRNAs and long noncoding RNAs can respectively or cooperatively function as oncogenes or tumor suppressor genes in human cancers. The present study identified that miR-449a was down-regulated in tissue of human lung cancer. In this study, we aimed to investigate the function of miR-449a in NL9980 and L9981 lung carcinoma cells lines and the relationship with lncRNA nuclear enriched abundant transcript 1 (NEAT1). MATERIALS AND METHODS miR-449a was profiled in several lung carcinoma cell lines by quantitative reverse transcription-polymerase chain reaction RT-PCR. We analyzed the effects of miR-449a overexpression on proliferation, apoptosis and cell cycle in L9981 cells. The regulatory relationship between miR-449a and NEAT1 was predicted in silico and further studied by miR-449a inhibitor and mimics assay. RESULTS miR-449a was expressed in four cell lines, which we selected, however miR-449a was in high level in NL9980 and in low level in L9981 (P < 0.05). When the miR-449a was the overexpression in L9981 cells, the cell growth was suppressed, and the apoptosis cells were promoted compared with the control group (P < 0.05). The G1/G0 became longer and S, G2/M became shorter (P < 0.05) by miR-449a overexpression. Further study of the interaction between miR-449a and NEAT1 show that NEAT1 was up-regulated when cells were transfected with miR-449a inhibitor, and NEAT1 was down-regulated when cells transfected with miR-449a mimics. CONCLUSIONS Our data indicate that miR-449a may function as a suppressor of lung cancer, and affects the expression of NEAT1 in lung cancer cells.

Noncoding RNA small nucleolar RNA host gene 1 promote cell proliferation in nonsmall cell lung cancer

BACKGROUND Nonsmall cell lung cancer (NSCLC) is the major cause of cancer death worldwide. Increasing evidence shows that noncoding RNAs (ncRNAs) are widely involved in the development and progression of NSCLC. ncRNA small nucleolar RNA host gene 1 (SNHG1) has not been studied in cancer, especially its role in lung cancer remains unknown. Our studies were designed to investigate the expression and biological significance of SNHG1 in lung cancer. SNHG1 may be a novel ncRNA in early diagnosis in lung cancer. METHODS Noncoding RNA SNHG1 expression in 7 lung cancer cell lines was measured by quantitative real-time polymerase chain reaction. RNA interference approaches were used to find the biological functions of SNHG1. The effect of SNHG1 on proliferation was evaluated by cell count and crystal violet stains. RESULTS Noncoding RNA SNHG1 expression was significantly upregulated in lung cancer cells when compared with normal bronchial epithelial cells. In addition, in vitro assays our results indicated that knockdown of SNHG1 inhibited cell proliferation. CONCLUSIONS Our data indicated that ncRNA SNHG1 is significantly upregulated in NSCLC cell lines and may represent a new biomarker and a potential therapeutic target for NSCLC intervention.

miR-132 inhibits lung cancer cell migration and invasion by targeting SOX4.

BACKGROUND Multiple MicroRNAs (miRNAs) have been identified in the development and progression of lung cancer. However, the expression and roles of miR-132 in non-small cell lung cancer (NSCLC) remain largely undefined. The aim of this study is to investigate the biological functions and its molecular mechanisms of miR-132 in human lung cancer cells. METHODS miR-132 expression was measured in human lung cancer cell lines by quantitative real-time PCR (qRT-PCR). The cells migration and invasion ability were measured by wound healing assay and transwell assay. The influence of miR-132 on tumor progression in vivo was monitored using NSCLC xenografts in nude mice. The target gene of miR-132 was determined by luciferase assay and western blot. RESULTS The expression level of miR-132 was dramatically decreased in examined lung cancer cell lines. Then, we found that introduction of miR-132 significantly suppressed the migration and invasion of lung cancer cells in vitro. Besides, miR-132 overexpression could also inhibit tumor growth in the nude mice. Further studies indicated that the sex determining region Y-box 4 (SOX4) is a target gene of miR-132. SOX4 re-introduction could reverse the anti-invasion role of miR-132. CONCLUSIONS Our finding provides new insight into the mechanism of NSCLC progression. Therapeutically, miR-132 may serve as a potential target in the treatment of human lung cancer.

Anti‐apoptotic brain and reproductive organ‐expressed proteins enhance cisplatin resistance in lung cancer cells via the protein kinase B signaling pathway

Cisplatin‐based chemotherapy is the standard first‐line treatment for non‐small‐cell lung cancers (NSCLCs); however, the long‐term therapeutic effect is reduced by chemoresistance. Brain and reproductive organ‐expressed (BRE) proteins are overexpressed in several cancers and have an anti‐apoptotic function. However, their biological role in the development of the chemoresistant phenotype of human NSCLC remains unknown. We investigate the differential expression of the BRE gene in human lung adenocarcinoma cell lines A549 and the cisplatin‐resistant variant A549/cisplatin (DDP), and the mechanisms of cisplatin‐resistance induced by the BRE gene.

Nm23-H1 was involved in regulation of KAI1 expression in high-metastatic lung cancer cells L9981

BACKGROUND The tetraspanin KAI1/CD82 was identified as a tumor metastasis suppressor that down-regulated in malignant progression of lung cancer. However, the underlying mechanism of anti-metastasis role of KAI1 in lung cancer is hardly known. In this paper, we sought to study the function and regulatory mechanism of KAI1 in high metastasis lung cancer cell line. METHODS KAI1 expression was detected in high/low metastatic large lung cancer cell line L9981/NL9980 by quantitative real-time polymerase chain reaction (qRT-PCR). The tumor suppressor function of KAI1 was determined by wound healing assay after over-expression or knockdown of KAI1 in L9981 or NL9980 cells. Invasion assay was performed to detect the invasion ability of L9981 by transfection of KAI1. The effect of tumor suppressor p53 on KAI1 expression was measured by western blot and luciferase assay. Then the regulation of KAI1 due to over-expression of metastasis suppressor nm23-H1 was monitored by qRT-PCR, western blot and reporter gene assay. The progression of L9981 cells after p53 and nm23-H1 expression was detected by invasion assay. Also, methylation status of KAI1 promoter in NL9980 and L9981 cells were examined by bisulfite sequencing and methylation-specific PCR. RESULTS We found that KAI1 is down-regulated in high metastatic L9981 cells compare with NL9980 cells. The migration and invasion of L9981 cells were remarkably suppressed in vitro by KAI1 transfection. The migration ability of NL9980 was enhanced by inhibition of KAI1. Furthermore, KAI1 expression was induced after over-expression of p53 or nm23-H1, while cell invasion was inhibited in L9981 cells. The results of reporter analysis indicated that KAI1 promoter region between -922 to -846 could response to nm23-H1. In addition, we discovered only slight methylation of KAI1 promoter, which showed that loss expression of KAI1 in L9981 cells may not due to promoter methylation. CONCLUSIONS The results suggested that nm23-H1 was involved in the KAI1-regulated inhibition of metastasis in lung cancer cells. More insights into the relationship between KAI1 and other metastasis suppressors will pave the way for the elucidation of anti-metastasis mechanism in lung cancer.

Activating transcription factor 3 promotes malignance of lung cancer cells in vitro

Lung cancer remains the most common cause of cancer‐related death, with high rates of recurrence and poor outcomes. An abnormally high expression of activating transcription factor 3 (ATF3) in various cancers suggests an oncogenic role; however, its function in lung cancer is largely unknown.

WW45, a Gli1 binding protein, negatively regulated Hedgehog signaling in lung cancer

Over-expression of Gli1 is very common in lung cancer. However, the underlying molecular mechanism remains largely unknown. Here, using mass spectrum, we have identified WW45 as a binding partner of Gli1. WW45 interacted with Gli1, promoted its ubiquitination and inhibited the expression of its target genes. In the functional studies, WW45 inhibited the growth and migration of lung cancer cells. Knocking down the expression of WW45 promoted the growth and migration of lung cancer cells, which was rescued by down-regulation of Gli1. Moreover, over-expression of WW45 inhibited the tumorigenesis in a de novo lung cancer tumorigenesis mouse model (LKB-Ras) as well as the expression of Gli1. Also over-expression of WW45 improved the survival of these mice. In addition, the expression of WW45 was down-regulated in the clinical lung cancer samples, which was inversely correlated with the expression of Gli1. Taken together, this study demonstrated the suppressive roles of WW45 in lung cancer by inhibiting the Hedgehog/Gli1 signaling.