Background Mounting evidence has demonstrated the vital importance of tumor-associated macrophages (TAMs) and exosomes in the formation of the premetastatic niche. However, the molecular mechanisms by which tumor-derived exosomal miRNAs interact with TAMs underlying premetastatic niche formation and colorectal cancer liver metastasis (CRLM) remain largely unknown. Methods Transmission electron microscopy and differential ultracentrifugation were used to verify the existence of exosomes. In vivo and in vitro assays were used to identify roles of exosomal miR-934. RNA pull-down assay, dual-luciferase reporter assay, etc. were applied to clarify the mechanism of exosomal miR-934 regulated the crosstalk between CRC cells and M2 macrophages. Results In the present study, we first demonstrated the aberrant overexpression of miR-934 in colorectal cancer (CRC), especially in CRLM, and its correlation with the poor prognosis of CRC patients. Then, we verified that CRC cell-derived exosomal miR-934 induced M2 macrophage polarization by downregulating PTEN expression and activating the PI3K/AKT signaling pathway. Moreover, we revealed that hnRNPA2B1 mediated miR-934 packaging into exosomes of CRC cells and then transferred exosomal miR-934 into macrophages. Interestingly, polarized M2 macrophages could induce premetastatic niche formation and promote CRLM by secreting CXCL13, which activated a CXCL13/CXCR5/NFκB/p65/miR-934 positive feedback loop in CRC cells. Conclusions These findings indicate that tumor-derived exosomal miR-934 can promote CRLM by regulating the crosstalk between CRC cells and TAMs. These findings reveal a tumor and TAM interaction in the metastatic microenvironment mediated by tumor-derived exosomes that affects CRLM. The present study also provides a theoretical basis for secondary liver cancer.

BackgroundColorectal cancer (CRC) is 3rd most commonly diagnosed cancer in males and the second in females. PD-1/PD-L1 axis, as an immune checkpoint, is up-regulated in many tumors and their microenvironment. However, the prognostic value of PD-1/PD-L1 in CRC remains unclear.MethodsThe Cancer Genome Atlas (TCGA) database (N = 356) and Fudan University Shanghai Cancer Center (FUSCC) cohort of patients (N = 276) were adopted to analyze the prognostic value of PD-L1 in colorectal tumor cells (TCs) and of PD-1 in tumor infiltrating cells (TILs) for CRC. Subgroup analyses were conducted in FUSCC cohort according to patients’ status of mismatch repair.ResultsIn TCGA cohort, the cut-off values of PD-1 and PD-L1 expression were determined by X-tile program, which were 4.40 and 2.92, respectively. Kaplan-Meier analysis indicated that higher PD-1 and PD-L1 expressions correlated with better OS (P = 0.032 and P = 0.002, respectively). In FUSCC cohort, expressions of PD-1 on TILs and PD-L1 on TCs were analyzed separately by immunohistochemistry (IHC) staining based on a TMA sample (N = 276) and revealed that both TILs-PD-1 and TCs-PD-L1 were associated with OS (P = 0.006 and P = 0.002, respectively) and DFS (P = 0.025 and P = 0.004, respectively) of CRC patients. Multivariate Cox regression analysis indicated TILs-PD-1 was an independent prognostic factor both for OS and DFS of CRC patients (P < 0.05). Subgroup analyses showed that TILs-PD-1 was an independent prognostic factor for both OS and DFS in CRC patients in MSS-proficient subgroup (P < 0.05), while neither of them correlated with OS or DFS in MSS-deficient subgroup (P > 0.05).ConclusionsHigher expressions of PD-1 and PD-L1 correlates with better prognosis of CRC patients. TILs-PD-1 is an independent prognostic factor for OS and DFS of CRC patients, especially for MMR-proficient subgroup.Electronic supplementary materialThe online version of this article (doi:10.1186/s12943-016-0539-x) contains supplementary material, which is available to authorized users.

Rationale : Colorectal cancer (CRC) is a malignant tumor with the third highest morbidity rate among all cancers. Driven by the host's genetic makeup and environmental exposures, the gut microbiome and its metabolites have been implicated as the causes and regulators of CRC pathogenesis. We assessed human fecal samples as noninvasive and unbiased surrogates to catalog the gut microbiota and metabolome in patients with CRC. Methods : Fecal samples collected from CRC patients (CRC group, n = 50) and healthy volunteers (H group, n = 50) were subjected to microbiome (16S rRNA gene sequencing) and metabolome (gas chromatography-mass spectrometry, GC-MS) analyses. The datasets were analyzed individually and integrated for combined analysis using various bioinformatics approaches. Results : Fecal metabolomic analysis led to the identification of 164 metabolites spread across 40 metabolic pathways in both groups. In addition, there were 42 and 17 metabolites specific to the H and CRC groups, respectively. Sequencing of microbial diversity revealed 1084 operational taxonomic units (OTUs) across the two groups, and there was less species diversity in the CRC group than in the H group. Seventy-six discriminatory OTUs were identified for the microbiota of H volunteers and CRC patients. Integrated analysis correlated CRC-associated microbes with metabolites, such as polyamines (cadaverine and putrescine). Conclusions : Our results provide substantial evidence of a novel interplay between the gut microbiome and metabolome (i.e., polyamines), which is drastically perturbed in CRC. Microbe-associated metabolites can be used as diagnostic biomarkers in therapeutic explorations.

Increasing evidence indicates that inflammation plays a vital role in tumorigenesis and progression. However, the prognostic value of inflammatory biomarkers in colorectal cancer (CRC) has not been established. In this study, a retrospective analysis was conducted in patients with CRC in Fudan University Shanghai Cancer Center (FUSCC) between April 1, 2007 and April 30, 2014, and 5,336 patients were identified eligible. Neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), lymphocyte-to-monocyte ratio (LMR), and albumin/globulin ratio (AGR) were analyzed. Kaplan-Meier analysis was used to calculate the 5-year overall survival (OS) and disease-free survival (DFS). Cox regression analysis was performed to assess the prognostic factors. Nomograms were established to predict OS and DFS, and Harrell's concordance index (c-index) was adopted to evaluate prediction accuracy. As results, the 5-year OS was 79.2% and the 5-year DFS was 56.0% in the cohort. Patients were stratified into 2 groups by NLR (2.72 and >2.72), PLR (219.00 and >219.00), LMR (2.83 and >2.83) and AGR (<1.50 and 1.50). Patients with NLR > 2.72, PLR > 219.00, LMR 2.83 and AGR < 1.50 were significantly associated with decreased OS and DFS (p < 0.001). Multivariate analysis indicated that NLR, LMR and AGR were independent factors of OS (p 5 0.047, p 5 0.008 and p < 0.001, respectively) and DFS (p 5 0.009, p < 0.001 and p 5 0.008, respectively). In addition, nomograms on OS and DFS were established according to all significant factors, and c-indexes were 0.765 (95% CI: 0.744-0.785) and 0.735 (95% CI: 0.721-0.749), respectively. Nomograms based on OS and DFS can be recommended as practical models to evaluate prognosis for CRC patients.Colorectal cancer (CRC) is the third most commonly diagnosed cancer in males and the second in females.1 The estimated global 5-year prevalence rate of CRC was 68.2/100,000, and cancer death rate caused by CRC was about 8.5%. 2 Compared with developed countries, the 5-year prevalence rate of CRC is significantly lower in China (52.7/100,000), but the mortality-to-prevalence ratio (MPR) of CRC in China (14%) is a lot higher, 2 which indicates that the overall survival outcome of CRC is apparently worse in China. Surgical resection remains the only curative treatment option for colorectal cancer. However, a considerable proportion of CRC patients develop recurrence or metastasis within 5 years after surgical treatment. Thus, a better model to predict the prognosis of CRC patients after radical resection is urgently needed.

BackgroundWe have previously demonstrated an aberrant overexpression of the microtubule-associated protein TPX2 in colon cancer using a genome-wide gene expression profiling analysis. Here, we aim to investigate its expression pattern, clinical significance, and biological function in colon cancer.MethodsTPX2 expression was analyzed in human colon cancer cell lines and tumor samples. The effect of TPX2 on cell proliferation, tumorigenesis, and metastasis was examined in vitro and in vivo.ResultsTPX2 was overexpressed in 129 of the 203 (60.8%) colon cancer metastatic lesions, with the expression being significantly higher than that in primary cancerous tissue and normal colon mucosa. Overexpression of TPX2 was significantly associated with clinical staging, vessel invasion, and metastasis. In survival analyses, patients with TPX2 overexpression had worse overall survival and metastasis free survival, suggesting that deregulation of TPX2 may contribute to the metastasis of colon cancer. Consistent with this, suppression of TPX2 expression inhibited proliferation and tumorigenicity of colon cancer cells both in vitro and in vivo. Strikingly, we found that TPX2 knockdown significantly attenuated the migration and invasion ability of colon cancer cells, which was further shown to be mechanistically associated with AKT-mediated MMP2 activity.ConclusionsThese findings suggest that TPX2 plays an important role in promoting tumorigenesis and metastasis of human colon cancer, and may represent a novel prognostic biomarker and therapeutic target for the disease.

BACKGROUND & AIMS: Genome-wide association studies (GWASs) have associated approximately 50 loci with risk of colorectal cancer (CRC)-nearly one third of these loci were initially associated with CRC in studies conducted in East Asian populations. We conducted a GWAS of East Asians to identify CRC risk loci and evaluate the generalizability of findings from GWASs of European populations to Asian populations. METHODS: We analyzed genetic data from 22,775 patients with CRC (cases) and 47,731 individuals without cancer (controls) from 14 studies in the Asia Colorectal Cancer Consortium. First, we performed a meta-analysis of 7 GWASs (10,625 cases and 34,595 controls) and identified 46,554 promising risk variants for replication by adding them to the Multi-Ethnic Global Array (MEGA) for genotype analysis in 6445 cases and 7175 controls. These data were analyzed, along with data from an additional 5705 cases and 5961 controls genotyped using the OncoArray. We also obtained data from 57,976 cases and 67,242 controls of European descent. Variants at identified risk loci were functionally annotated and evaluated in correlation with gene expression levels. RESULTS: A meta-analyses of all Gastroenterology 2019;156:1455-1466 BASIC AND TRANSLATIONAL AT samples from people of Asian descent identified 13 loci and 1 new variant at a known locus (10q24.2) associated with risk of CRC at the genome-wide significance level of P < 5 Â 10-8. We did not perform experiments to replicate these associations in additional individuals of Asian ancestry. However, the lead risk variant in 6 of these loci was also significantly associated with risk of CRC in European descendants. A strong association (44%-75% increase in risk per allele) was found for 2 lowfrequency variants: rs201395236 at 1q44 (minor allele frequency, 1.34%) and rs77969132 at 12p11.21 (minor allele frequency, 1.53%). For 8 of the 13 associated loci, the variants with the highest levels of significant association were located inside or near the protein-coding genes L1TD1, EFCAB2, PPP1R21, SLCO2A1, HLA-G, NOTCH4, DENND5B, and GNAS. For other intergenic loci, we provided evidence for the possible involvement of the genes ALDH7A1, PRICKLE1, KLF5, WWOX, and GLP2R. We replicated findings for 41 of 52 previously reported risk loci. CONCLUSIONS: We showed that most of the risk loci previously associated with CRC risk in individuals of European descent were also associated with CRC risk in East Asians. Furthermore, we identified 13 loci significantly associated with risk for CRC in Asians. Many of these loci contained genes that regulate the immune response, Wnt signaling to bcatenin, prostaglandin E2 catabolism, and cell pluripotency and proliferation. Further analyses of these genes and their variants is warranted, particularly for the 8 loci for which the lead CRC risk variants were not replicated in persons of European descent.

Marital status was found to be an independent prognostic factor for survival in various cancer types, but it hasn’t been fully studied in colorectal cancer (CRC). The Surveillance, Epidemiology and End Results database was used to compare survival outcomes with marital status in each stage. In total, 112, 776 eligible patients were identified. Patients in the widowed group were more frequently elderly women, more common of colon cancer, and more stage I/II in tumor stage (P < 0.001), but the surgery rate was comparable to that for the married group (94.72% VS 94.10%). Married CRC patients had better 5year cause-specific survival (CSS) than those unmarried (P < 0.05). Further analysis showed that widowed patients always presented the lowest CSS compared with that of other’ group. Widowed patients had 5% reduction 5-year CSS compared with married patients at stage I (94.8% vs 89.8%, P < 0.001), 9.4% reduction at stage II (85.9% vs 76.5%, P < 0.001), 16.7% reduction at stage III (70.6% vs 53.9%, P < 0.001) and 6.2% reduction at stage IV(14.4% VS 8.2%, P < 0.001). These results showed that unmarried patients were at greater risk of cancer specific mortality. Despite favorable clinicpathological characteristics, widowed patients were at highest risk of death compared with other groups.

The incidence of sporadic young-onset colorectal cancer (yCRC) is increasing. A significant knowledge gap exists in the gut microbiota and its diagnostic value for yCRC patients. Through 16S rRNA gene sequencing, 728 samples are collected to identify microbial markers, and an independent cohort of 310 samples is used to validate the results. Furthermore, species-level and functional analysis are performed by metagenome sequencing using 200 samples. Gut microbial diversity is increased in yCRC. Flavonifractor plautii is an important bacterial species in yCRC, while genus Streptococcus contains the key phylotype in the old-onset colorectal cancer. Functional analysis reveals that yCRC has unique characteristics of bacterial metabolism characterized by the dominance of DNA binding and RNA-dependent DNA biosynthetic process. The random forest classifier model achieves a powerful classification potential. This study highlights the potential of the gut microbiota biomarkers as a promising non-invasive tool for the accurate detection and distinction of individuals with yCRC.