Project description:Eph receptors and their corresponding ephrin ligands have been associated with regulating cell-cell adhesion and motility, and thus have a critical role in various biological processes including tissue morphogenesis and homeostasis, as well as pathogenesis of several diseases. Aberrant regulation of Eph/ephrin signaling pathways is implicated in tumor progression of various human cancers. Here, we show that a Rho family GTPase regulator, Rho guanine nucleotide dissociation inhibitor 1 (RhoGDI1), can interact with ephrinB1, and this interaction is enhanced upon binding the extracellular domain of the cognate EphB2 receptor. Deletion mutagenesis revealed that amino acids 327-334 of the ephrinB1 intracellular domain are critical for the interaction with RhoGDI1. Stimulation with an EphB2 extracellular domain-Fc fusion protein (EphB2-Fc) induces RhoA activation and enhances the motility as well as invasiveness of wild-type ephrinB1-expressing cells. These Eph-Fc-induced effects were markedly diminished in cells expressing the mutant ephrinB1 construct (Δ327-334) that is ineffective at interacting with RhoGDI1. Furthermore, ephrinB1 depletion by siRNA suppresses EphB2-Fc-induced RhoA activation, and reduces motility and invasiveness of the SW480 and Hs578T human cancer cell lines. Our study connects the interaction between RhoGDI1 and ephrinB1 to the promotion of cancer cell behavior associated with tumor progression. This interaction may represent a therapeutic target in cancers that express ephrinB1.
Project description:MicroRNA (miRNA)-25 is a small non-coding RNA that has been implicated in the tumorigenesis of many cancers, but little is known on the role of miR-25 in HCC metastasis. We hereby found that miR-25 was significantly upregulated in clinical HCC tissues compared with normal liver tissues. We also revealed that miR-25 dramatically stimulates HCC cell growth and activates the epithelial-mesenchymal transition (EMT). MiR-25 is activated by the WNT/β-catenin signaling pathway, and exerts its pro-metastatic function by directly inhibiting the Rho GDP dissociation inhibitor alpha (RhoGDI1). Downregulation of RhoGDI1 enhances expression of Snail, thereby promoting EMT. MiR-25 levels are positively correlated with β-catenin expression, whereas negatively correlated with the level of RhoGDI1 in HCC. Our findings provide new insights into the role of miR-25 in HCC metastasis, and implicate the potential application of miR-25 in HCC therapy.
Project description:Colorectal cancer (CRC) is one of the most common types of malignancy worldwide. Distant metastasis is a key cause of CRC‑associated mortality. MEIS2 has been identified to be dysregulated in several types of human cancer. However, the mechanisms underlying the regulatory role of MEIS2 in CRC metastasis remain largely unknown. For the first time, the present study demonstrated that MEIS2 serves a role as a promoter of metastasis in CRC. In vivo and in vitro experiments revealed that knockdown of MEIS2 significantly suppressed CRC migration, invasion and the epithelial‑mesenchymal transition. Furthermore, microarray and bioinformatics analyses were performed to investigate the underlying mechanisms of MEIS2 in the regulation of CRC metastasis. Additionally, it was identified that a high expression of MEIS2 was significantly associated with a shorter overall survival time for patients with CRC. The present study demonstrated that MEIS2 may serve as a novel biomarker for CRC.
Project description:B7-H3 (B7 homologue 3, CD276) is a member of the B7 immunoregulatory family and promotes tumor progression. The present study demonstrated that B7-H3 promotes gastric cancer cell migration and invasion. shRNA-mediated B7-H3 silencing in the N87 gastric cancer cell line suppressed cell migration and invasion in vitro and in vivo; downregulated metastasis-associated CXCR4; and inhibited AKT, ERK, and Jak2/Stat3 phosphorylation. B7-H3-silenced cells injected into the tail veins of 4-week-old female BALB/c nude mice produced fewer metastases than control cells, and resulted in longer survival times. Immunofluorescence analyses confirmed B7-H3/CXCR4 colocalization in N87 cells, and co-immunoprecipitation assays showed a direct interaction between the two proteins. Our analysis of 120 tissue samples from gastric cancer patients showed that increased B7-H3 expression correlated positively with both tumor infiltration depth and CXCR4 expression. These findings suggest that B7-H3 and CXCR4 may be novel targets for anti-gastric cancer therapeutics.
Project description:The expression status of ZKSCAN3, a zinc-finger transcription factor containing KRAB and SCAN domains, as well as its biological significance, in human bladder cancer remains largely unknown. In the current study, we aimed to determine the functional role of ZKSCAN3 in bladder cancer progression. Immunohistochemistry in tissue specimens detected ZKSCAN3 signals in 138 (93.2%) of 148 urothelial neoplasms, which was significantly higher than in non-neoplastic urothelial tissues [76 (84.4%) of 90; P=0.044]. Correspondingly, the levels of ZKSCAN3 gene were significantly elevated in bladder tumors, compared with those in adjacent normal-appearing bladder mucosae (P=0.008). In a validation set of tissue microarray, significantly higher ZKSCAN3 expression was observed in high-grade and/or muscle-invasive urothelial carcinomas than in low-grade and/or non-muscle-invasive tumors. Two bladder cancer cell lines, UMUC3 and 647V, were found to strongly express ZKSCAN3 protein/mRNA, whereas its expression in 5637 bladder cancer and SVHUC normal urothelium cell lines was very weak. ZKSCAN3 silencing via its short hairpin RNA (shRNA) in UMUC3 and 647V resulted in significant decreases in cell viability/colony formation, cell migration/invasion, and the expression of matrix metalloproteinase (MMP)-2/MMP-9 and oncogenes c-myc/FGFR3, as well as significant increases in apoptosis and the expression of tumor suppressor genes p53/PTEN. ZKSCAN3 overexpression in 5637 also induced cell growth and migration. In addition, ZKSCAN3-shRNA expression considerably retarded tumor formation as well as its subsequent growth in xenograft-bearing mice. These results suggest that ZKSCAN3 plays an important role in bladder cancer outgrowth. Thus, ZKSCAN3 inhibition has the potential of being a therapeutic approach for bladder cancer.
Project description:Small nucleolar RNAs (snoRNAs) play a crucial role during colorectal cancer (CRC) development. The study of SNORA71A is few, and its role in CRC is unknown. This study focused on screening abnormal snoRNAs in CRC and exploring the role of key snoRNA in CRC. The expression pattern of snoRNAs in 3 CRC and 3 normal colon tissues was detected via small RNA sequencing. The six candidate snoRNAs were identified by quantitative PCR (qPCR). Subsequently, the expression level of SNORA71A was further verified through the Cancer Genome Atlas (TCGA) data analysis and qPCR. The CCK8 and transwell assays were used to detect the functional role of SNORA71A in CRC cells. The integrated analysis of snoRNA expression profile indicated that a total 107 snoRNAs were significantly differentially expressed (DE) in CRC tissues compared with normal tissues, including 45 upregulated and 62 downregulated snoRNAs. Bioinformatics analysis revealed that the DE snoRNAs were mainly implicated in "detection of chemical stimulus involved in sensory perception of smell" and "sensory perception of smell" in the biological process. The DE snoRNAs were preferentially enriched in "olfactory transduction" and "glycosphingolipid biosynthesis-ganglio series pathway." The expression of SNORA71A was upregulated in CRC tissues and cells. SNORA71A expression showed statistically significant correlations with TNM stage (P = 0.0196) and lymph node metastasis (P = 0.0189) and can serve as biomarkers for CRC. Importantly, SNORA71A significantly facilitated the CRC cell proliferation, migration, and invasion. Our findings indicate that SNORA71A screened by sequencing acted as an oncogene and promoted proliferation, migration, and invasion ability of CRC cells.
Project description:Long non-coding RNAs (lncRNAs) serve crucial roles in carcinogenesis. Myocardial infarction-associated transcript (MIAT), originally isolated as a candidate gene for myocardial infarction, has been revealed to serve as an oncogene in chronic lymphocytic leukaemias and neuroendocrine prostate cancer. However, little is known about its expression pattern, biological function and underlying mechanism in esophageal cancer. Cell lines of esophageal cancer were used in the current study. The results of the present study revealed that MIAT knockdown decreased cell viability, migration, invasion and cell cycle arrest in the G1 phase. Mechanistic assessment revealed that MIAT interacts with histone methyltransferase mixed-lineage leukemia (MLL). The relative proteins expressions were measured by western blotting assay. MIAT knockdown suppressed cell invasion and migration by regulation MMP-2/9 protein expressions. The results of the current study indicated that MIAT expression was associated with esophageal cancer and may serve as a critical target in the progression and metastasis in esophageal cancer.
Project description:The sodium-dependent vitamin C transporter 2 (SVCT2) surface glycoprotein regulates ascorbate accumulation in the plasma, often resulting in the induction of cancer cell death. Therefore, high expression of this gene associates with increased overall survival in several cancers. However, in colorectal cancer (CRC), high (likely mutated) SVCT2 expression relates to poor overall survival, and its functional significance has not been studied. Thus, we hypothesize that mutant SVCT2 expression could affect CRC patient survival. According to biological databases, SVCT2 has been found to be mutated frequently, and SVCT2 E264K has a particularly high pathogenic score (0.98), compared to other SVCT2 mutant sites, in CRC patients. Interestingly, our results reveal expression of SVCT2 E264K in many CRC tissues and cells. Also, we found wild-type SVCT2 expression to be largely localized to the cytoplasm and membrane, while SVCT2 E264K was restricted to the cytoplasm. We further found that SVCT2 E264K overexpression increases cell growth. By contrast, SVCT2 E264K knockdown significantly reduced cell proliferation and promoted cell apoptosis, resulting in inhibition of cell invasion and migration. Taken together, SVCT2 E264K plays a critical role in proliferation in CRC. Our results suggest that SVCT2 E264K could be a promising novel therapeutic target in CRC.
Project description:The pRb-E2F pathway is a critical point of regulation in the cell cycle and loss of control of the pathway is a hallmark of cancer. E2F1 is the major target through which pRb exerts its effects and arginine methylation by PRMT5 plays a key role in dictating E2F1 activity. Here we have explored the functional role of the PRMT5-E2F1 axis and highlight its influence on different aspects of cancer cell biology including viability, migration, invasion and adherence. Through a genome-wide expression analysis, we identified a distinct set of genes under the control of PRMT5 and E2F1, including some highly regulated genes, which influence cell migration, invasio and adherence through a PRMT5-dependent mechanism. Most significantly, a coincidence was apparent between the expression of PRMT5 and E2F1 in human tumours, and elevated levels of PRMT5 and E2F1 correlated with poor prognosis disease. Our results suggest a causal relationship between PRMT5 and E2F1 in driving the malignant phenotype and thereby highlight an important pathway for therapeutic intervention.
Project description:Circular RNAs (circRNAs) participate in gene regulation and malignant tumor progression, including uterine cervical cancer (CC). In this study, the expression profile of circRNAs in CC was detected using circRNA microarrays. Then, we selected hsa_circ_0000745 for further examination from the significantly dysregulated circRNAs. Proliferation assays, Transwell assays, quantitative reverse transcription polymerase chain reaction, western blot analysis and tumorigenesis tests in vivo were used to validate the role of hsa_circ_0000745 in CC. hsa_circ_0000745 was upregulated in CC, and its level positively correlated with the level of its linear messenger RNA isoform. Patients with poorly differentiated tumors or vascular/lymphatic invasion presented higher expression of hsa_circ_0000745. The role of hsa_circ_0000745 was illuminated by knocking down hsa_circ_0000745 in CC cells, and the results revealed that reducing hsa_circ_0000745 inhibited cell proliferation, migration, and invasion in CC by upregulating E-cadherin (E-cad) expression. In summary, as a tumor promoter in CC, hsa_circ_0000745 enhances the cell's ability to proliferate, migrate, and invade by reducing the expression of E-cad. hsa_circ_0000745 is a candidate target for the treatment of CC in the clinic.