Background It has been well established that circular RNAs (circRNAs) play an important regulatory role during tumor progression. Recent studies have indicated that even though circRNAs generally regulate gene expression through miRNA sponges, they may encode small peptides in tumor pathogenesis. However, it remains largely unexplored whether circRNAs are involved in the tumorigenesis of colon cancer (CC). Methods The expression profiles of circRNAs in CC tissues were assessed by circRNA microarray. Quantitative real-time PCR, RNase R digestion assay and tissue microarray were used to confirm the existence and expression pattern of circPPP1R12A. The subcellular distribution of circPPP1R12A was analyzed by nuclear mass separation assay and fluorescence in situ hybridization (FISH). SDS-PAGE and LC/MS were employed to evaluate the protein-coding ability of circPPP1R12A. CC cells were stably transfected with lentivirus approach, and cell proliferation, migration and invasion, as well as tumorigenesis and metastasis in nude mice were assessed to clarify the functional roles of circPPP1R12A and its encoded protein circPPP1R12A-73aa. RNA-sequencing and Western blotting analysis were furthered employed to identify the critical signaling pathway regulated by circPPP1R12A-73aa. Results We firstly screened the expression profiles of human circRNAs in CC tissues and found that the expression of hsa_circ_0000423 (termed as circPPP1R12A) was significantly increased in CC tissues. We also found that circPPP1R12A was mostly localized in the cytoplasm of CC cells. Kaplan–Meier analysis showed that patients with higher levels of circPPP1R12A had a significantly shorter overall survival. By gain- and loss-of-function approaches, the results suggested that circPPP1R12A played a critical role in proliferation, migration and invasion of CC cells. Furthermore, we showed that circPPP1R12A carried an open reading frame (ORF), which encoded a functional protein (termed as circPPP1R12A-73aa). Next, we found that PPP1R12A-C, not circPPP1R12A, promoted the proliferation, migration and invasion abilities of CC in vitro and in vivo. Finally, we identified that circPPP1R12A-73aa promoted the growth and metastasis of CC via activating Hippo-YAP signaling pathway. In addition, the YAP specific inhibitor Peptide 17 dramatically alleviated the promotive effect of circPPP1R12A-73aa on CC cells. Conclusions In the present study, we illustrated the coding-potential of circRNA circPPP1R12A in the progression of CC. Moreover, we identified that circPPP1R12A-73aa promoted the tumor pathogenesis and metastasis of CC via activating Hippo-YAP signaling pathway. Our findings might provide valuable insights into the development of novel potential therapeutic targets for CC. Electronic supplementary material The online version of this article (10.1186/s12943-019-1010-6) contains supplementary material, which is available to auth...

background. Immunotherapy with immune checkpoint inhibitors has emerged as promising treatment modality for cancer based on the success of anti-CTLA-4 and -PD-1/PD-L1 antibodies. LAG-3 and TIM-3 are two new immune checkpoints. The aim of this work is to review the role and application of LAG-3 and TIM-3 for cancer immunotherapy. Material and methods. Literatures were searched and collected in Medline/PubMed. results. LAG-3 is presented as a CD4 homolog type I transmembrane protein which binds MHC class II molecules. LAG-3 negatively regulates T cell proliferation, homeostasis and function. IMP321 is formed of an extracellular portion of human LAG-3 fused to the Fc fraction of human IgG1 and has shown increased T cell responses and tolerability in phase I studies on advanced renal cell cancer. When combined with paclitaxel, IMP321 has exerted immune enhancement and tumor inhibition with no significant IMP321-related adverse events. TIM-3 belongs to the TIM family and mainly negatively regulates Th1 immunity. The TIM-3/galectin-9 pathway contributes to the suppressive tumor microenvironment. TIM-3 overexpression is associated with poor prognosis in a variety of cancers. Both LAG-3 and TIM-3 are coexpressed with other immune checkpoints. The application of LAG-3 or TIM-3 does play an important role in anti-tumor responses, and maybe better when combing with anti-CTLA-4 and anti-PD-1/L1 antibodies. conclusions. These two immune checkpoints play crucial roles in cancer development and may be used in future clinical practice of cancer therapy.

Background: B7-H3 exhibits altered expression in various cancers. However, the correlation between B7-H3 expression and prognosis of cancer patients remains controversial. Therefore, we elicit a meta-analysis to investigate the potential value of B7-H3 in the prognostic prediction in human cancers. Materials and Methods: We searched PubMed (last update by June 15th, 2016) to identify studies assessing the effect of B7-H3 on survival of cancer patients. Hazard ratios (HRs) for overall survival (OS), recurrence free survival (RFS) and progression-free survival (PFS) from individual studies were calculated and pooled by using a random-effect or fix-effect model, and heterogeneity and publication bias analyses were also performed. Results: Data from 24 observational studies consisting of 4141 patients were summarized. An elevated baseline B7-H3 was significantly correlated with poor OS (pooled HR = 2.09; 95% CI =1.60-2.74; P < 0.001). Differences across subgroups of tumor type (P = 0.324), year of publication (P = 0.431), ethnicity (P = 0.940), source of HR (P = 0.145), analysis type (P = 0.178) and sample size (P = 0.909) were not significant. Furthermore, high B7-H3 expression also predicted a significantly poor RFS (pooled HR = 1.39; 95% CI = 1.11-1.75; P = 0.004) but not PFS. Conclusions: This meta-analysis clarifies that elevated B7-H3 expression is significantly associated with poor survival in cancer patients.

The microRNA expression profile of plasma exosomes in osteosarcoma needs to be further explored. The present study intends to investigate the practicality of plasma exosomal miRNAs as novel biomarkers of osteosarcoma. In the study, exosome-like vesicles were purified from the plasma of patients with osteosarcoma and healthy control. Differential centrifugation was used. The purified vesicles which ranged from 50 to 100 nm in size were identified as exosomes by transmission electron microscopy and western blot. Validating assays in vitro and in vivo were performed via CCK8, reverse transcription-quantitative PCR, flow cytometry, transwell and wound healing assays and xenograft model. High-throughput sequencing identified that 57 miRNAs, 20 of which were upregulated and 37 downregulated, were differentially expressed in patients with osteosarcoma and healthy control (p<0.01; fold change ≥3). In comparison to the controls, the expression levels of miR-92a-3p, miR-130a-3p, miR-195–3 p, miR-335–5 p, let-7i-3p were upregulated in the exosomes from patients with osteosarcoma with statistical significance. Studies in vitro and in vivo have proved that osteosarcoma-secreted exosomes from miR-195–3 p upregulated 143B osteosarcoma cells promote cell proliferation and invasion. Overall, the present study identified exosomal miRNAs with dysregulated expression in patients with osteosarcoma, and they may have potential as targets for the treatment of patients with osteosarcoma.

Objective The microRNA expression profile of plasma exosomes in prostate cancer (PCa) is of critical importance in the disease exploration. This study aimed to explore the clinical application of exosomal miRNAs as biomarkers for PCa. Methods Exosome-like vesicles of PCa patients and healthy controls were purified by differential centrifugation. The purified vesicles within the ranges of 50 and 100 nm were classified as exosomes according to the results of transmission electron microscopy and Western blot. Both, in vitro and in vivo, validations were performed by small RNA sequencing, CCK8, RT-qPCR, flow cytometry, Western blot, transwell and immunofluorescent staining assays. Results High-throughput sequencing identified that 94 miRNAs were differentially expressed in PCa patients in comparison with healthy controls ( P <0.01; fold change ≥2). Among them, 64 miRNAs were upregulated, and 30 miRNAs were downregulated. In comparison to the healthy controls, the expression levels of miR-217 were significantly upregulated, while miR-23b-3p were significantly downregulated in the exosomes and serum collected from PCa patients. Both, in vitro and in vivo, studies revealed that exosomes secreted by PCa cells with up-regulated miR-217 levels promoted cell proliferation and invasion; meanwhile, the exosomes with up-regulated miR-23b-3p levels inhibited cell proliferation and invasion. The epithelial–mesenchymal transition process may have been involved in the above-mentioned regulation. Conclusion This study identified the dysregulated expression of exosomal miRNAs in PCa patients, including miR-217 and miR-23b-3p, by validating their function on proliferation and invasion in PCa cells. This regulation may have been affected by the epithelial–mesenchymal transition process, suggesting that they can be used as potential targets in the diagnosis and treatment of PCa.