Background:Functional microRNAs (miRNAs) in exosomes have been recognised as potential stable biomarkers in cancers. The aim of this study is to identify specific miRNAs in exosome as serum biomarkers for the early detection of recurrence in human colorectal cancer (CRC).Methods:Serum samples were sequentially obtained from six patients with and without recurrent CRC. The miRNAs were purified from exosomes, and miRNA microarray analysis was performed. The miRNA expression profiles and copy number aberrations were explored using microarray and array CGH analyses in 124 CRC tissues. Then, we validated exosomal miRNAs in 2 serum sample sets (90 and 209 CRC patients) by quantitative real-time RT–PCR.Results:Exosomal miR-17-92a cluster expression level in serum was correlated with the recurrence of CRC. Exosomal miR-19a expression levels in serum were significantly increased in patients with CRC as compared with healthy individuals with gene amplification. The CRC patients with high exosomal miR-19a expression showed poorer prognoses than the low expression group (P<0.001).Conclusions:Abundant expression of exosomal miR-19a in serum was identified as a prognostic biomarker for recurrence in CRC patients.

Background:We previously conducted gene expression microarray analyses to identify novel indicators for colorectal cancer (CRC) metastasis and prognosis from which we identified PVT-1 as a candidate gene. PVT-1, which encodes a long noncoding RNA, mapped to chromosome 8q24 whose copy-number amplification is one of the most frequent events in a wide variety of malignant diseases. However, PVT-1 molecular mechanism of action remains unclear.Methods:We conducted cell proliferation and invasion assays using colorectal cancer cell lines transfected with PVT-1siRNA or negative control siRNA. Gene expression microarray analyses on these cell lines were also carried out to investigate the molecular function of PVT-1. Further, we investigated the impact of PVT-1 expression on the prognosis of 164 colorectal cancer patients by qRT–PCR.Results:CRC cells transfected with PVT-1 siRNA exhibited significant loss of their proliferation and invasion capabilities. In these cells, the TGF-β signalling pathway and apoptotic signals were significantly activated. In addition, univariate and multivariate analysis revealed that PVT-1 expression level was an independent risk factor for overall survival of colorectal cancer patients.Conclusion:PVT-1, which maps to 8q24, generates antiapoptotic activity in CRC, and abnormal expression of PVT-1 was a prognostic indicator for CRC patients.

A primary tumor can create a premetastatic niche in distant organs to facilitate the development of metastasis. The mechanism by which tumor cells communicate with host cells to develop premetastatic niches is unclear. We focused on the role of microRNA (miR) signaling in promoting metastasis. Here, we identified miR-203 as a signaling molecule between tumors and monocytes in metastatic colorectal cancer (CRC) patients. Notably, high expression of serum exosomal miR-203, a major form in circulation, was associated with distant metastasis and an independent poor prognostic factor, whereas low expression in tumor tissues was a poor prognostic factor in CRC patients. We also found that exosomes carrying miR-203 from CRC cells were incorporated into monocytes and miR-203 could promote the expression of M2 markers in vitro, suggesting miR-203 promoted the differentiation of monocytes to M2-tumor-associated macrophages (TAMs). In a xenograft mouse model, miR-203-transfected CRC cells developed more liver metastasis compared to control cells. In conclusion, serum exosomal miR-203 expression is a novel biomarker for predicting metastasis, possibly via promoting the differentiation of monocytes to M2-TAMs in CRC. Furthermore, we propose the concept of site-dependent functions for miR-203 in tumor progression.

We previously developed γ-glutamyl hydroxymethyl rhodamine green (gGlu-HMRG) as a tool to detect viable cancer cells, based on the fact that the enzyme γ-glutamyltranspeptidase (GGT) is overexpressed on membranes of various cancer cells, but is not expressed in normal tissue. Cleavage of the probe by GGT generates green fluorescence. Here, we examined the feasibility of clinical application of gGlu-HMRG during breast-conserving surgery. We found that fluorescence derived from cleavage of gGlu-HMRG allowed easy discrimination of breast tumors, even those smaller than 1 mm in size, from normal mammary gland tissues, with 92% sensitivity and 94% specificity, within only 5 min after application. We believe this rapid, low-cost method represents a breakthrough in intraoperative margin assessment during breast-conserving surgery.

LncRNA-ATB plays an important role in EMT to promote invasion and metastasis through the TGF-β/miR-200s/ZEB axis, resulting in a poor prognosis in GC. LncRNA-ATB is a novel biomarker of lncRNA, indicative of a poor prognosis in GC patients.