CD73 expression correlates closely with HIF-1α expression in gastric carcinoma. CD73 could be an independent prognostic indicator for gastric carcinoma.

Background/Aims: The aim of this study is to investigate the clinicopathological and prognostic values of miR-149 expression and its roles in colorectal cancer (CRC) progression. Methods: qRT-PCR was performed to detect miR-149 expression in CRC cell lines or tissues. Also, the clinical significance of miR-149 expression was investigated. The study further explored whether miR-149 inhibits migration and invasion of CRC cells by targeting the mammalian Forkhead Box M1 (FOXM1). Results: miR-149 was significantly downregulated in CRC tissues, and low miR-149 expression was observed to be significantly correlated with lymph node or distant metastasis and advanced TNM stage of CRC patients. Patients with low miR-149 expression showed poorer prognosis than those with high miR-149 expression, and multivariate analyses indicated that status of miR-149 expression might be an independent prognostic factor. Gain- and loss - of - function assays indicated that miR-149 significantly inhibited growth, migration and invasion of CRC cells by targeting FOXM1. Furthermore, FOXM1 was significantly uiregulated in CRC tissues and inversely correlated with miR-149 expression. Conclusions: mR-149 was an independent prognostic factor and could inhibit migration and invasion of CRC cells, at least partially by targeting FOXM1.

5-Fluorouracil (5-FU) is the most commonly used chemotherapeutic agent for colorectal cancer (CRC). However, frequently occurred 5-FU resistance poses a great challenge in the clinic. Elucidating the underlying mechanisms and developing effective strategies against 5-FU resistance are highly desired. Here we identified the upregulation of FOXM1 in 5-FU nonresponsive CRC patients by gene expression profile analysis and 5-FU-resistant CRC cells by qRT-PCR assay. Silencing of FOXM1 promoted the sensitivity of CRC cells to 5-FU by enhancing cell apoptosis, while overexpression of FOXM1 conferred CRC cells with 5-FU resistance both in vitro and in vivo. Furthermore, we showed that genetic and pharmacological inhibition of FOXM1 resensitized resistant CRC cells to 5-FU treatment. Mechanistically, FOXM1 promoted the transcription of ABCC10 by directly binding to its promoter region. Notably, treatment with ABCC10 inhibitor reversed FOXM1-induced resistance to 5-FU in vivo. Clinical investigation revealed that the levels of FOXM1 and ABCC10 were positively correlated in CRC tissues. Therefore, FOXM1 promotes 5-FU resistance by upregulating ABCC10, suggesting that FOXM1/ABCC10 axis may serve as a potential therapeutic target for 5-FU resistance in CRC patients.

The whole outcome for patients with gastric carcinoma (GC) is very poor because most of them remain metastatic disease during survival even at diagnosis or after surgery. Despite many improvements in multiple strategies of chemotherapy, immunotherapy, and targeted therapy, exploration of novel alternative therapeutic targets is still warranted. Chemokine receptor 4 (CXCR4) and its chemokine ligand 12 (CXCL12) have been identified with significantly elevated levels in various malignancies including GC, which correlates with the survival, proliferation, angiogenesis, and metastasis of tumor cells. Increasing experimental evidence suggests an implication of inhibition of CXCL12/CXCR4 axis as a promising targeted therapy, although there are rare trials focused on the therapeutic efficacy of CXCR4 inhibitors in GC until recently. Therefore, it is reasonable to infer that specific antagonists or antibodies targeting CXCL12/CXCR4 axis alone or combined with chemotherapy will be effective and worthy of further translational studies as a potential treatment strategy in advanced GC.

Background/Aims: Previously, we have shown that microRNA (miR)-149 suppresses the migration and invasion of colorectal cancer (CRC) cells by targeting forkhead box transcription factor (FOXM1). However, the roles of miR-149 in the chemoresistance of CRC cells to 5-Fluorouracil (5-FU) is unclear. The aim of this study is to investigate whether miR-149 targets FOXM1 to regulate the 5-FU resistance of CRC. Methods: The qRT-PCR assay was performed to detect the expression of miR-149 in 5-FU-resistant CRC cells (HCT-8/5-FU and LoVo/5-FU) and their parental CRC cells (HCT-8 and LoVo). Also, the effects of miR-149 expression on the sensitivity of CRC cells to 5-FU were determined by gain- and loss-of-function assays. Finally, whether miR-149 regulates the 5-FU resistance of CRC cells by targeting the mammalian Forkhead Box M1 (FOXM1) was investigated. Results: The expression of miR-149 was significantly downregulated in 5-FU-resistant CRC cells in comparison with their parental CRC cells. Re-expression of miR-149 could enhance the 5-FU sensitivity of 5-FU-resistant CRC cells by increasing 5-FU-inducing apoptosis, while downregulation of miR-149 could decrease the 5-FU sensitivity of parental CRC cells by decreasing 5-FU-inducing apoptosis. In addition, the luciferase assay indicated that miR-149 could bind to the 3'-UTR sequence of FOXM1 mRNA. The silencing of FOXM1 could mimic the effect of miR-149 upregulation on the 5-FU resistance of 5-FU-resistant CRC cells. Furthermore, the expression of miR-149 in the 5-FU-responding CRC tissues was significantly higher than that in the non-responding tissues and inversely correlated with FOXM1 mRNA level. Conclusions: MiR-149 reverses the resistance of CRC cells to 5-FU by directly targeting FOXM1. Thus, targeting miR-149/FOXM1 signaling will be a potential strategy in the treatment of 5-FU-chemoresistant CRC.

Epigenetic mechanisms play a key role in non-targeted effects of radiation. The purpose of this study was to investigate global hypomethylation and promoter hypermethylation of particular genes induced by low dose radiation (LDR). Thirty male BALB/c mice were divided into 3 groups: control, acutely exposed (0.5Gy X-rays), and chronic exposure for 10 days (0.05Gy/d×10d). High-performance liquid chromatography (HPLC) and MeDIP-quantitative polymerase chain reaction (qPCR) were used to study methylation profiles. DNMT1 and MBD2 expression was determined by qPCR and western blot assays. Methylation and expression of Rad23b and Ddit3 were determined by bisulfate sequencing primers (BSP) and qPCR, respectively. The results show that LDR induced genomic hypomethylation in blood 2 h postirraditaion, but was not retained at 1-month. DNMT1 and MBD2 were downregulated in a tissue-specific manner but did not persist. Specific hypermethylation was observed for 811 regions in the group receiving chronic exposure, which covered almost all key biological processes as indicated by GO and KEGG pathway analysis. Eight hypermethylated genes (Rad23b, Tdg, Ccnd1, Ddit3, Llgl1, Rasl11a, Tbx2, Scl6a15) were verified by MeDIP-qPCR. Among them, Rad23b and Ddit3 gene displayed tissue-specific methylation and downregulation, which persisted for 1-month postirradiation. Thus, LDR induced global hypomethylation and tissue-specific promoter hypermethylation of particular genes. Promoter hypermethylation, rather than global hypomethylation, was relatively stable. Dysregulation of methylation might be correlated with down-regulation of DNMT1 and MBD2, but much better understanding the molecular mechanisms involved in this process will require further study.

BackgroundTranscription factor forkhead box M1 (FOXM1) is a crucial regulator in colorectal cancer (CRC) progression. However, the regulatory mechanisms causing dysregulation of FOXM1 in CRC remain unclear.MethodsDual-luciferase reporter assay was conducted to determine FOXM1 as miR-6868-5p target. The function of miR-6868-5p and FOXM1 in CRC angiogenesis was verified in vitro. Intratumoral injection model was constructed to explore the effect of miR-6868-5p on angiogenesis in vivo. Chromatin immunoprecipitation assays were used to assess direct binding of H3K27me3 to the miR-6868 promoter.ResultsThrough integrated analysis, we identified miR-6868-5p as the potent regulator of FOXM1. Overexpression of miR-6868-5p in CRC cells inhibited the angiogenic properties of co-cultured endothelial cells, whereas silencing of miR-6868-5p had opposite effects. In vivo delivery of miR-6868-5p blocked tumor angiogenesis in nude mice, resulting in tumor growth inhibition. Rescue of FOXM1 reversed the effect of miR-6868-5p on tumor angiogenesis. Further mechanistic study revealed that FOXM1 promoted the production of IL-8, which was responsible for the miR-6868-5p/FOXM1 axis-regulated angiogenesis. Reciprocally, FOXM1 inhibited miR-6868-5p expression through EZH2-mediated H3K27me3 on miR-6868-5p promoter, thus forming a feedback circuit. Clinically, the level of miR-6868-5p was downregulated in CRC tissues and inversely correlated with microvessel density as well as levels of FOXM1 and IL-8 in tumor specimens.ConclusionsTogether, these data identify miR-6868-5p as a novel determinant of FOXM1 expression and establish a miR-6868-5p/FOXM1 regulatory circuit for CRC angiogenesis, providing potential target for CRC treatment.Electronic supplementary materialThe online version of this article (10.1186/s13046-018-0970-5) contains supplementary material, which is available to authorized users.

Most of gastric carcinoma (GC) is attributed to infection by Helicobacter pylori (H. pylori) but there is increasing evidence that the positive H. pylori status correlates with better prognosis in GC. The H. pyloriinduced cellular immune response may suppress cancer and in this work, recombinant pcDNA3 plasmids encoding various fragments of H. pylori virulence genes of cagA, vacA and babA are constructed and combined into groups to immunize BALB/c mice. The activated splenic CD3 + T cells are purified and the anticancer effects are investigated in vitro and in vivo. The H. pylori DNA vaccines induce a shift in the response from Th1 to Th2 that mimicks the immune status in patients of GC with chronic H. pylori infection. The stimulated CD3 + T cells inhibit the growth of human GC cells in vitro and adoptive transfusions of the CD3 + T cells suppress the growth of GC xenograft in vivo. The effects may be caused by the larger ratios of infiltrated CD8 + /CD4 + T cells, reduced infiltration of regulatory FOXP3 + T cells, and enhanced apoptosis induced by upregulation of Caspase-9/Caspase-3 and downregulation of Survivin. Our results reveal the potential immunotherapeutic value of H. pylori vaccine-activated CD3 + T cells in those with advanced GC.