B-Myb Is Up-Regulated and Promotes Cell Growth and Motility in Non-Small Cell Lung Cancer
INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
Authors: Jin, Yuelei; Zhu, Huifang; Cai, Wei; Fan, Xiaoyan; Wang, Yitao; Niu, Yulong; Song, Fangzhou; Bu, Youquan
Abstract
B-Myb is a transcription factor that is overexpressed and plays an oncogenic role in several types of human cancers. However, its potential implication in lung cancer remains elusive. In the present study, we have for the first time investigated the expression profile of B-Myb and its functional impact in lung cancer. Expression analysis by quantificational real-time polymerase chain reaction (qRT-PCR) and immunohistochemistry demonstrated that B-Myb expression is aberrantly overexpressed in non-small cell lung cancer (NSCLC), and positively correlated with pathologic grade and clinical stage of NSCLC. A gain-of-function study revealed that overexpression of B-Myb significantly increases lung cancer cell growth, colony formation, migration, and invasion. Conversely, a loss-of-function study showed that knockdown of B-Myb decreases cell growth, migration, and invasion. B-Myb overexpression also promoted tumor growth in vivo in a NSCLC xenograft nude mouse model. A molecular mechanistic study by RNA-sequencing (RNA-seq) analysis showed that B-Myb overexpression causes up-regulation of various downstream genes (e.g., COL11A1, COL6A1, FN1, MMP2, NID1, FLT4, INSR, and CCNA1) and activation of multiple critical pathways (e.g., extracellular signal-regulated kinases (ERK) and phosphorylated-protein kinase B (Akt) signaling pathways) involved in cell proliferation, tumorigenesis, and metastasis. Collectively, our results indicate a tumor-promoting role for B-Myb in NSCLC and thus imply its potential as a target for the diagnosis and/or treatment of NSCLC.
CEP55 promotes the proliferation and invasion of tumour cells via the AKT signalling pathway in osteosarcoma
CARCINOGENESIS
Authors: Xu, Leilei; Xia, Chao; Sheng, Fei; Sun, Qi; Xiong, Jin; Wang, Shoufeng
Abstract
The molecular mechanisms underlying the development of osteosarcoma (OS) are not fully understood. In this study, we investigated for the first time the clinical significance and biological activity of centrosomal protein 55 (CEP55) in OS. We found that CEP55 was overexpressed in OS, and the CEP55 expression level in OS was correlated with metastasis and poor prognosis. Through in vitro experiments, we confirmed that CEP55 knockdown significantly induced cell cycle arrest at G1 phase and suppressed OS cell proliferation, migration and invasion. In addition, CEP55 knockdown suppressed OS tumour growth in nude mice. Global gene expression profiling of CEP55-silenced MNNG/HOS cells showed that the AKT pathway might be involved in the regulation of OS cell activity. Two downstream factors of AKT signalling, CCND1 and FN1, were found to have significantly higher expression in tumour tissues, and their mRNA expression levels were strongly correlated with CEP55 expression. To conclude, our data suggest that CEP55 can be used as a prognostic marker for OS, highlighting the significance of CEP55 signalling as a putative therapeutic target.Overexpression of CEP55 correlated with osteosarcoma metastasis and poor prognosis. Knockdown of CEP55 significantly suppressed the proliferation, migration and invasion of osteosarcoma cells both in vivo and in vitro, possibly via the AKT pathway.