Gene Expression Profiling in TWIST‐Depleted Gastric Cancer Cells

Abstract

TWIST is an important transcription factor during embryonic development and has recently been found to promote the epithelial-mesenchymal transition (EMT) phenomenon seen during the initial steps of tumor metastasis. To further investigate the potential targets and interacting genes of TWIST in human gastric cancer, we performed microarray analysis to compare the gene expression profiles in HGC-27 cells, with or without small interfering RNA (siRNA)-mediated depletion of TWIST. Our results showed that NF1, RAP1A, SRPX, RBL2, PFDN4, ILK, F2R, ERBB3, and MYB were up-regulated, whereas AKR1C2, FOS, GDF15, NR2F1, ATM, and CTPS were down-regulated after TWIST depletion. Moreover, TWIST-depleted HGC-27 cells showed a reversal of the morphologic and molecular changes associated with EMT. These results provide evidence that TWIST regulates the expression of several genes involved in the differentiation, adhesion, and proliferation of gastric cancer cells. The role of TWIST in the development of certain types of gastric cancer is discussed. Anat Rec, 292:262-270, 2009Rec, 292:262-270, . 2008 Wiley-Liss, Inc.Key words: TWIST; siRNA; epithelial-mesenchymal transition; gastric cancer; microarray Epithelial-mesenchymal transition (EMT) is pivotal for morphogenesis and in the transformation of early stage tumors into invasive malignancies (Kang and Massague, 2004). Cells undergoing EMT-characterized by the loss of cell polarity, cell-basement membrane adhesion, and cell-cell contacts-lose expression of epithelial markers (such as E-cadherin and catenin) and acquire expression of mesenchymal components (such as vimentin, fibronectin, and N-cadherin). Recent studies have shown that TWIST is one of the main regulatory proteins that promote EMT and the metastatic phenotype of cells (Karreth and Tuveson, 2004). Increased levels of TWIST are found in a wide range of cancers and are positively correlated with tumor aggressiveness and poor survival rates (Yang et al., 2004), suggesting a general role for TWIST in cancer development.TWIST is a basic helix-loop-helix (bHLH) transcription regulator that can form homodimers or heterodimers with partners that also contain an HLH domain. Depending on the protein partners in the dimers, these complexes play distinct roles in regulating the expression of downstream genes, acting either as activators or repressors. For example, TWIST homodimers can bind to the E-box of the E-cadherin promoter, repressing its expression, whereas their binding to the E-box of the Akt2 gene enhances its expression (Cheng et al

TWIST expression in hypopharyngeal cancer and the mechanism of TWIST-induced promotion of metastasis

“…After the silent TWIST expression, both c-fos and MMP-9 dramatically decreased, suggesting TWIST has a role in regulating c-fos and MMP-9 expression. The results agreed with the study that the depletion of TWIST results in decreased expression of the c-fos in gastric cancer cells (25). It has been reported that c-fos has oncogenic activity, is frequently overexpressed in tumor cells, and is thought to enhance motility and invasiveness of cancer cells (26).…”

Multiple genes identified as targets for 20q13.12–13.33 gain contributing to unfavorable clinical outcomes in patients with hepatocellular carcinoma

“…PFDN4, a transcriptional factor that regulates cell cycle, is highly expressed in breast cancer cell lines and tumor tissues and has been reported as a candidate tumor-related gene [42,43]. In vitro experiments have shown that PFDN4 plays an important role in tumor cell growth, invasiveness, and metastasis [44,45]. However, the role of PFDN4 in cancer progression is unclear because colorectal cancer patients with high tumor PFDN4 expression have been reported to have a better prognosis [45], whereas in the present study HCC patients with gain of 20q13.12-13.33 where PFDN4 located had a worse prognosis and high PFDN4 expression was associated with tumor vascular invasion.…”

Normal and disease-related biological functions of Twist1 and underlying molecular mechanisms

“…These results suggest that Twist1 may promote gastric cancer cell migration, invasion and metastasis via the Wnt/Tcf-4 signaling pathway. Microarray analyses revealed that depletion of Twist1 in the HGC-27 gastric cancer cells increased the expression of NF1, RAP1A, SRPX, RBL2, PFDN4, ILK (integrin-linked kinase), F2R, ERBB3, and MYB, and decreased the expression of AKR1C2, FOS, GDF15, NR2F1, ATM, and CTPS, supporting that many Twist1-regulated genes are involved in the differentiation, adhesion and proliferation of gastric cancer cells [112]. The same research group also discovered that the MGC-803 and HGC-27 gastric cancer cells with higher Twist1 levels exhibited higher invasive potential than did the BGC-823 and SGC-7901 gastric cancer cells with lower Twist1 levels.…”