MicroRNAs (miRNAs) regulate tumor progression and invasion via direct interaction with target messenger RNAs (mRNAs). We defined miRNAs involved in cancer metastasis (metastamirs) using an established in vitro colorectal cancer (CRC) model of minimally metastatic cells (SW480 line) from a colon adenocarcinoma primary lesion and highly metastatic cells (SW620 line) from a metastatic lymph node from the same patient 1 year later. We used microarray analysis to identify miRNAs differentially expressed in SW480 and SW620 cells, focusing on miR-499-5p as a novel candidate prometastatic miRNA whose functions in cancer had not been studied. We confirmed increased miR-499-5p levels in highly invasive CRC cell lines and lymph node-positive CRC specimens. Furthermore, enhancing the expression of miR-499-5p promoted CRC cell migration and invasion in vitro and lung and liver metastasis in vivo, while silencing its expression resulted in reduced migration and invasion. Additionally, we identified FOXO4 and PDCD4 as direct and functional targets of miR-499-5p. Collectively, these findings suggested that miR-499-5p promoted metastasis of CRC cells and may be useful as a new potential therapeutic target for CRC.

BackgroundFOXO4, a member of the FOXO family of transcription factors, is currently the focus of intense study. Its role and function in gastric cancer have not been fully elucidated. The present study was aimed to investigate the expression profile of FOXO4 in gastric cancer and the effect of FOXO4 on cancer cell growth and metastasis.MethodsImmunohistochemistry, Western blotting and qRT-PCR were performed to detect the FOXO4 expression in gastric cancer cells and tissues. Cell biological assays, subcutaneous tumorigenicity and tail vein metastatic assay in combination with lentivirus construction were performed to detect the impact of FOXO4 to gastric cancer in proliferation and metastasis in vitro and in vivo. Confocal and qRT-PCR were performed to explore the mechanisms.ResultsWe found that the expression of FOXO4 was decreased significantly in most gastric cancer tissues and in various human gastric cancer cell lines. Up-regulating FOXO4 inhibited the growth and metastasis of gastric cancer cell lines in vitro and led to dramatic attenuation of tumor growth, and liver and lung metastasis in vivo, whereas down-regulating FOXO4 with specific siRNAs promoted the growth and metastasis of gastric cancer cell lines. Furthermore, we found that up-regulating FOXO4 could induce significant G1 arrest and S phase reduction and down-regulation of the expression of vimentin.ConclusionOur data suggest that loss of FOXO4 expression contributes to gastric cancer growth and metastasis, and it may serve as a potential therapeutic target for gastric cancer.

No abstract

BackgroundPhosphatase and tensin homolog (PTEN) is an important tumor suppressor gene, and its encoded protein has activities of both a protein phosphatase and a lipid phosphatase. However, the substitution effect of protein phosphatase activity remains unclear. PI3K/Akt is the most common pathway negatively regulated by PTEN. The Hippo and PI3K/Akt pathways have a joint effect in regulating cell proliferation and apoptosis. Therefore, how PTEN lipid phosphatase inactivation contributes to the occurrence and development of gastric cancer and the potential role of the Hippo and PI3K/Akt pathways in PTEN lipid phosphatase inactivation mediated gastric tumorigenesis remain to be explored.MethodsImmunohistochemical staining was performed to detect the expression of p-PTEN and YAP in a gastric cancer tissue microarray. Stable cell lines expressing a wild-type or dominant-negative mutant PTEN were established. The proliferation and migration of stable cells were detected by MTT, BrdU, and colony-formation, transwell assay and high content analysis in vitro, and tumor growth differences were observed in xenograft nude mice. Changes in the expression of key molecules in the Hippo and Akt signaling pathways were detected by western blot. Nuclear-cytoplasm separation, immunofluorescence and coimmunoprecipitation analyses were conducted to explore the dysregulation of Hippo in the stable cell lines.ResultsPTEN lipid phosphatase inactivation strongly promoted the proliferation and migration of gastric cancer cells in vitro and tumor growth in vivo. A immunohistochemical analysis of gastric cancer tissues revealed a significant correlation between phosphorylated PTEN and nuclear YAP expression, and both were determined to be independent prognostic factors for gastric cancer. Mechanistically, PTEN lipid phosphatase inactivation abolished the MOB1-LATS1/2 interaction, decreased YAP phosphorylation and finally promoted YAP nuclear translocation, which enhanced the synergistic effect of YAP-TEAD, thus inducing cell proliferation and migration. Moreover, PTEN lipid phosphatase inactivation promoted the PI3K/Akt pathway, and disruption of YAP-TEAD-driven transcription decreased the activation of Akt in a dose-dependent manner.ConclusionsTaken together, our findings indicate that PTEN lipid phosphatase inactivation links the Hippo and PI3K/Akt pathways to promote gastric tumorigenesis and cancer development.Electronic supplementary materialThe online version of this article (10.1186/s13046-018-0795-2) contains supplementary material, which is available to authorized users.

Multi-drug resistance (MDR) remains a great obstacle to effective chemotherapy for gastric cancer. A number of secreted glycoproteins have been reported to be involved in the development of MDR in gastric cancer. However, whether glycosylation of secreted glycoproteins changes during MDR of gastric cancer is unclear. Our present work manifested that N-glycosites and site-specific glycoforms of secreted proteins in drug-resistant cell lines were distinctly different from those in the parental cell line for the first time. Further characterization highlighted the significance of some aberrantly glycosylated secretory proteins in MDR, suggesting that manipulating the glycosylation of specific glycoproteins could be a potential target for overcoming multi-drug resistance in gastric cancer.

No abstract

No abstract

Context.-The expression of membrane-bound complement regulatory proteins (mCRPs) that inhibit the complement system in normal tissues is essential for selfprotection against an autologous immune reaction. However, the expression patterns of mCRPs, including CD46, CD55, and CD59, are inconsistent in different types of cancer cells.Objectives.-To determine whether CD46, CD55, and CD59 are differentially expressed in neoplastic and adjacent normal colon tissues and to assess their clinical significance.Design.-Immunohistochemistry was performed on tissue microarrays of cancerous and adjacent normal colon tissues.Results.-The expression levels of CD46, CD55, and CD59 were significantly higher in colon cancer tissues compared with the normal adjacent colon tissues. We found that the expression levels of CD55 and CD59 correlated with the grade of differentiation in colon cancers. In addition, the expression of CD55 and CD59 was greater in stage III and stage IV colon cancers than in stage I and stage II cancers according to staging by the TNM classification.Conclusions.-CD46, CD55, and CD59 are up-regulated in colon cancer. Specifically, CD55 and CD59 are of clinical relevance to differentiation and TNM staging of colon cancer. These data suggest that CD46, CD55, and CD59 have the potential to be used for molecular staging diagnoses and for colon cancer therapies.(Arch Pathol Lab Med. 2014;138:910-919; doi: 10.5858/ arpa.2013-0064-OA) I mmunotherapies using monoclonal antibodies (mAbs) have attracted great attention from oncologists because these mAbs can be used to directly or indirectly damage tumor cells, while sparing normal, healthy cells. In addition, complement activation by mAbs can mediate direct tumor cell lysis or antibody-dependent cell-mediated cytotoxicity. Specifically, complement activation results in the formation of C3-convertase and C5-convertase, and the cleavage of C3 leads to the generation of C3b, which attaches to the cell surface and causes amplification of the complement cascade. Cleavage of C5 by C5-convertase results in fragmentation of C5 into C5a and C5b, C5b could form a complex with C6 and C7 at the membrane surface (C5b-7 complex), and C5b-7 complex binds C8abc to form the C5b-8 complex, which ultimately binds sequentially to multiple copies of C9 to form the mature membrane attack complex. The membrane attack complex then leads to direct complement-dependent cytotoxicity (CDC) through the formation of membranepenetrating pores.1 Because the targeting of cells by CDC is destructive and irreversible, complement activation is tightly regulated by complement regulatory proteins (CRPs) to avoid uncontrolled activation and an autologous immune reaction. Complement regulatory proteins exist as soluble proteins or as membrane-bound CRPs (mCRPs). The mCRPs include mainly CD46, CD55, and CD59. Also called membrane cofactor protein (MCP), CD46 is the cofactor for factor I-mediated degradation of C3b and C4b, which prevents the continuous formation of convertases. Decayaccelerating factor, also k...