Colorectal cancer is one of the common malignant tumors, which seriously threatens human health. Its morbidity and mortality rank the third and the second among all malignant tumors. The progress of colorectal cancer is a complex process involving the accumulation of genetic and epigenetic changes. Epigenetic changes of colorectal cancer mainly include DNA methylation, histone modification, non-coding RNAs (such as microRNAs and lncRNAs), which are of great significance to early diagnosis and prognosis evaluation, and to chemosensitivity assessment for colorectal cancer, providing a new thought for the treatment of colorectal cancer.

OBJECTIVE: To investigate the expression, clinical significance, and biological function of the long non-coding RNA (lncRNA) ADAMTS9-AS2 in colorectal cancer (CRC).
 Methods: Gene microarray analysis was performed to explore the expression of ADAMTS9-AS2 in CRC. Real-time PCR was used to verify its expression in 20-paired CRC tissues and adjacent non-tumor tissues. We further explored the relationship between ADAMTS9-AS2 expression and clinicopathological features, and its prognostic role in relapse-free survival (RFS) among early stage CRC patients using Kaplan-Meier and Cox regression analyses. In vitro assays, cell counting kit-8 assay, colony formation assay, and Transwell assay were used to evaluate the biological function of ADAMTS9-AS2 in CRC.
 Results: ADAMTS9-AS2 was down-regulated in CRC patients according to the gene microarray analysis, which was confirmed in CRC tissues and cells. High expression of ADAMTS9-AS2 was associated with a higher 5-year RFS rate (83.8% vs 73.5%, P=0.041) and it was an independent prognostic factor for RFS [hazard ratio (HR)=0.528; 95% CI 0.299 to 0.932; P=0.028] at the early stage of CRC. ADAMTS9-AS2 overexpression in CRC cells inhibited cell proliferation, migration, and invasion, while suppression of ADAMTS9-AS2 showed opposite effects.
 Conclusion: ADAMTS9-AS2 is a valuable prognostic factor for CRC and may function as a tumor suppressor in CRC via inhibiting cell proliferation and metastasis.

CD133 is currently believed to be one of the best colorectal cancer stem cell markers. This study aimed to evaluate prognostic significance of CD133 expression in colorectal cancer patients.A total of 303 patients with stage I to III colorectal cancer who underwent curative surgical resection from 2003 to 2008 at a single institution were included. CD133 expression was evaluated using immunohistochemical staining, and clinicopathological data were retrospectively reviewed. The patients were dichotomized after scoring CD133 expression (0 to 2+: low CD133 expression vs 3+ to 4+: high CD133 expression) according to the extent of area of CD133 positive tumor cells (<50% vs ≥50%) and pattern of staining (membranous staining of the luminal surface and/or staining of cellular debris in the tumor glands and cytoplasm).The 5-year overall survival (OS) (61.9% vs 80.2%, P = .001) and disease-free survival (64.8% vs 75.8%, P = .026) were poorer in the high CD133 expression group than the low CD133 expression group. In the multivariate analysis for risk factors of OS in the whole population, higher nodal stage (N2 compared to N0: hazard ratio [HR] 3.141; 95% confidence interval [CI] 1.718-5.744, P < .001), perineural invasion (HR 2.262; 95% CI 1.347-3.798, P = .002) and high CD133 expression (HR 1.929; 95% CI 1.221-3.048, P = .005) were independent poor prognostic factors of OS. Subgroup analyses according to each TNM stage revealed that CD133 expression was associated with OS only within the stage II patients (HR 3.167 95% CI 1.221-8.216, P = .018). Furthermore, the stage II patients demonstrating the high CD133 expression showed survival benefit of adjuvant chemotherapy, regardless of high-risk feature positivity (HR 0.201 95% CI 0.054-0.750, P = .017).High CD133 expression is correlated with poor prognosis in colorectal cancer patients after radical resection. The CD133 expression may serve as a more potent and informative biomarker for prognosis than conventional high-risk features in the stage II colorectal cancer patients.

Insulin-like growth factor 1 (IGF1) is implicated in normal cell growth. It has been reported that IGF1 has a mitogenic and anti-apoptotic effect on colorectal cancer cells. However, results of studies on the association between cytosine-adenine (CA) repeat polymorphism in IGF1 gene promoter and colorectal cancer (CRC) risk are inconsistent. We aimed to evaluate the association between CA repeat polymorphism and CRC risk, as well as the relationship with the clinicopathological characteristics of CRC and circulating IGF1 level in a native Chinese population. There were 734 participants who were native Chinese in this case-control study, including 367 CRC cases and 367 age- and sex-matched controls. CA repeat polymorphism was genotyped by PCR and fragment analysis. Odds ratios (ORs) and 95% confidence intervals (CIs) were evaluated by unconditional logistic regression analysis. Circulating level of IGF1 in cases was significantly higher than that in controls (P = 0.002), particularly in males. Less than 38 CA repeats were associated with decreased CRC risk after adjusting for age and sex (37 versus 38 CA repeats: OR = 0.45; 95%CI = 0.26-0.78), especially in males. (CA)18/19 genotype showed approximately half reduced CRC risk comparing to (CA)19/19 genotype (OR = 0.46; 95%CI = 0.25-0.85). There was a significant association between the sum of CA repeats and degree of differentiation of CRC (P = 0.044). We observed a trend that circulating level of IGF1 in individuals with CA ≤ 38 repeats was lower than that in individuals with CA > 38 repeats with a borderline statistically significance in overall and males. In conclusion, our findings support the possible role of CA repeat polymorphism in CRC risk.

Lynch syndrome (LS), which is the most common hereditary colorectal cancer, accounts for about 3% of all colorectal cancers. However, due to its various clinical manifestations, it is difficult to be diagnosed. The diagnosis of LS requires comprehensive application of various screening criteria (such as the Amsterdam criteria, Bethesda criteria), predictive models, risk factors, immunohistochemistry test of mismatch repair (MMR) protein, microsatellite instability (MSI) detection, MLH1 methylation detection, BRAF gene mutation detection, germline gene mutation detection, and so on. LS can be diagnosed only after the identification of pathogenic germline mutation of MMR gene. The first-degree and second-degree relatives of LS patients are recommended to be tested for the identified mutant gene. For LS patients and gene mutation carriers, LS associated cancer can be detected early or even prevented by monitoring and preventive surgery. Reproductive techniques can be used to prevent this disease from being passed down to the next generation.

In this study we investigated the role of lncRNA MIR503HG in colorectal cancer (CRC). We found that MIR503HG was downregulated and TGF-β2 was upregulated in CRC included in this study. Low levels of MIR503HG were associated with poor survival of CRC patients within 5 years after admission. MIR503HG and TGF-β2 were inversely correlated in CRC tissues, and in CRC cells, MIR503HG overexpression was accompanied by TGF-β2 downregulation, while TGF-β2 overexpression did not affect MIR503HG. TGF-β2 overexpression mediated the increased migration and invasion rates of CRC cells. MIR503HG overexpression mediated the decreased migration and invasion rates of CRC cells. Moreover, TGF-β2 overexpression reduced the effects of MIR503HG overexpression. Therefore, MIR503HG overexpression inhibits CRC cell migration and invasion mediated by TGF-β2.

Aberrant expression of SRY-box 8 (SOX8) is closely correlated with the development and progression of many types of cancers in human. Limited studies report the relationship between SOX8 expression and overall survival in colorectal cancer (CRC). This study aimed to collect the pathological tissues and clinical data in order to analyze the relationship between SOX8 expression and clinicopathological parameters and prognosis of CRC patients. Tissue microarrays were constructed from 424 primary CRC patients with clinicopathological information and follow-up data. Immunohistochemistry (IHC) was performed on tissue microarrays to explore the relationship between SOX8 expression and clinicopathological information and patient's prognosis. The expression of SOX8 was higher in CRC tissues than that in non-tumor adjacent tissues (NATs, P <.001). High expression of SOX8 was associated with tumor stage (P = .04) and shorter overall survival (OS) after operation of patients (P = .004). Subsequently, univariate COX analysis identified that high expression of SOX8 (P = .004), differentiation (P = .006), distant metastasis (P <.001), tumor stage (P = .003), and higher rate of lymph node metastasis (P <.001), all significantly predicted decrease in OS. Multivariate analysis demonstrated that distant metastasis (P <.001), high SOX8 expression, (P = .013) and lymph node metastasis (P <.001) were independent poor prognostic factors in CRC patients. This study showed that SOX8 is over-expressed in patients with high T stage, which affects the outcome of prognosis in CRC patients. High expression of SOX8 usually has a poor independent prognostic factor for CRC.

BACKGROUND/AIM: Trifluridine (FTD) is a key component of the novel oral antitumor drug trifluridine/tipiracil that has been approved for the treatment of metastatic colorectal cancer. In this study, a comprehensive analysis of DNA replication profile in FTD-treated colon cancer cells was performed.
MATERIALS AND METHODS: HCT-116 cells were exposed to BrdU or FTD and subjected to DNA immunoprecipitation. Immunoprecipitated DNA was sequenced; the density of aligned reads along the genome was calculated. Peak finding, gene ontology, and motif analysis were performed using MACS, GREAT, and MEME, respectively.
RESULTS: We identified 6,043 and 5,080 high-confidence FTD and BrdU peaks in HCT-116 cells, respectively. Of 6,043 FTD peaks, 2,911 peaks were uncommon to BrdU. We observed that FTD was preferentially incorporated into genomic regions containing simple repeats, CpG islands, and gene bodies. Conserved motifs in FTD peaks contained dinucleotide repeats such as (GT)n.
CONCLUSION: Global FTD incorporation patterns delineated FTD, preferentially incorporating loci in cancer cells.

The cell-surface glycoprotein, mesothelin, is normally present on mesothelial cells. Overexpression of mesothelin has been reported in many tumors and is correlated with poor outcome. We investigated the clinicopathologic significance of mesothelin expression in colorectal adenocarcinoma with microsatellites instability (MSI) status.Mesothelin expression was evaluated immunohistochemically in tissue microarray blocks from 390 colorectal adenocarcinoma samples. Mesothelin expression was interpreted according to the intensity and extent. A score of 2 was considered high expression. We analyzed the correlation between mesothelin expression and clinicopathologic characteristics.High mesothelin expression was observed in 177 (45.4%) out of 390 colorectal adenocarcinoma samples and was significantly associated with high histologic grade (P = .037), lymphatic invasion (P = .028), lymph node metastasis (P = .028), and high AJCC stage (P = .026). Kaplan-Meier survival curves revealed no significant difference between patients with high mesothelin expression and patients with low mesothelin expression in both recurrence-free survival (RFS) and cancer-specific survival (P = .609 and P = .167, respectively). In subgroup survival analyses, high mesothelin expression was associated with poor RFS in the MSI-High group of colorectal adenocarcinoma (P = .004).High mesothelin expression was significantly associated with aggressive phenotypes and poor patient outcome in MSI-High colorectal adenocarcinoma.

BACKGROUND: The FOS gene is located on human chromosome 14q21-31 and encodes the nuclear oncoprotein c-Fos. This study analyzed the correlation between the FOS noncoding region rs7101 and rs1063169 polymorphisms and colorectal cancer susceptibility and prognosis.
METHODS: We analyzed the FOS genotypes in 432 colorectal cancer patients and 315 healthy subjects by PCR/Sanger sequencing. Survival was analyzed by Kaplan-Meier and Cox regression analysis. Western blot was used to detect the expression of c-Fos protein in cancer tissues and adjacent tissues in colorectal cancer patients with different genotypes.
RESULTS: The presence of a T allele at rs7101 and a T allele at rs1063169 in FOS carried a higher risk of colorectal cancer [adjusted odds ratio (OR) = 1.237, 95% confidence interval (95% CI) = 1.131-1.346, P ≤ .001 and adjusted OR = 1.218, 95% CI = 1.111-1.327, P ≤ .001, respectively]. c-Fos protein levels were significantly higher in variant cancer tissues than in normal mucosa tissues (P < .05), and c-Fos proteins levels were also higher in homozygous variant cancer tissues than in heterozygous variant cancer tissues. The 3-year survival rate of patients with wild-type FOS was higher than that of patients with variant FOS (P < .05).
CONCLUSION: The rs7101 and rs1063169 polymorphisms in the noncoding region of FOS are associated with the risk of developing colorectal cancer and the progression of colorectal cancer, which may be because the mutation enhances the expression of c-Fos protein to promote the incidence and development of colorectal cancer.

The utility of mRNA and protein determinations of G protein-coupled receptor 35, that is, GPR35a (GPR35 V1) and GPR35b (GPR35 V2/3), as indicators of outcome for colon cancer patients after curative surgery was investigated. Expression levels of V1 and V2/3 GPR35, carcinoembryonic antigen and CXCL17 mRNAs were assessed in primary tumours and regional lymph nodes of 121 colon cancer patients (stage I-IV), colon cancer cell lines and control colon epithelial cells using real-time quantitative reverse transcriptase-polymerase chain reaction. Expression of G protein-coupled receptor 35 was investigated by two-colour immunohistochemistry and immunomorphometry. GPR35 V2/3 mRNA, but not V1 mRNA, was expressed in colon cancer cell lines, primary colon tumours and control colon epithelial cells. Haematoxylin and eosin positive (H&E(+)), but not H&E(-), lymph nodes expressed high levels of GPR35 V2/3 mRNA (

BACKGROUND: Predicting meaningful miRNA-disease associations (MDAs) is costly. Therefore, an increasing number of researchers are beginning to focus on methods to predict potential MDAs. Thus, prediction methods with improved accuracy are under development. An efficient computational method is proposed to be crucial for predicting novel MDAs. For improved experimental productivity, large biological datasets are used by researchers. Although there are many effective and feasible methods to predict potential MDAs, the possibility remains that these methods are flawed.
RESULTS: A simple and effective method, known as Nearest Profile-based Collaborative Matrix Factorization (NPCMF), is proposed to identify novel MDAs. The nearest profile is introduced to our method to achieve the highest AUC value compared with other advanced methods. For some miRNAs and diseases without any association, we use the nearest neighbour information to complete the prediction.
CONCLUSIONS: To evaluate the performance of our method, five-fold cross-validation is used to calculate the AUC value. At the same time, three disease cases, gastric neoplasms, rectal neoplasms and colonic neoplasms, are used to predict novel MDAs on a gold-standard dataset. We predict the vast majority of known MDAs and some novel MDAs. Finally, the prediction accuracy of our method is determined to be better than that of other existing methods. Thus, the proposed prediction model can obtain reliable experimental results.

5-fluorouracil in combination with the folate leucovorin is the cornerstone in treatment of colorectal cancer. Transport of leucovorin into cells, and subsequent metabolic action, require expression of several genes. The aim was to analyze if tumoral expression of genes putatively involved in leucovorin transport, polyglutamation, or metabolism was associated with outcome of patients with stage III colorectal cancer treated with adjuvant chemotherapy. A total of 363 stage III colorectal cancer patients who received adjuvant bolus 5-fluorouracil + leucovorin alone, or in combination with oxaliplatin according to Nordic bolus regimes were included. Expression of 11 folate pathway genes was determined in tumors using quantitative real-time polymerase chain reaction and related to disease-free survival. The median follow-up time was 5 years. During follow-up, 114 (31%) patients suffered from recurrent disease. A high tumoral expression of the genes

BACKGROUND/AIM: The aim of this study was to examine the role of caspase-8 rs3834129 polymorphism on colorectal cancer (CRC) risk in Taiwanese CRC patients and healthy controls.
MATERIALS AND METHODS: The caspase-8 rs3834129 (-652 6N insertion/deletion) polymorphic genotypes were analyzed in 362 patients with CRC and the same number of age- and gender-matched healthy subjects. The interaction of caspase-8 rs3834129 genotypes with personal behaviors and clinicopathological features were also examined.
RESULTS: The percentage of variants ID and DD for caspase-8 rs3834129 genotype were 37.6 and 5.8% in CRC group and 39.0 and 6.6% in the control group, respectively (p for trend=0.7987). The allelic frequency distribution analysis showed that caspase-8 rs3834129 D allele conferred a non-significant lower susceptibility for CRC compared with I allele (OR=0.92, 95%CI=0.74-1.20, p=0.5063). There was no obvious link between caspase-8 rs3834129 genotype and CRC risk among ever-smokers, non-smokers, non-alcohol drinkers or alcohol drinkers. No statistically significant correlation was observed between caspase-8 rs3834129 genotypic distribution and age, gender, tumor size, location or metastasis status.
CONCLUSION: Overall, caspase-8 rs3834129 genotypes may not serve as predictors for CRC risk or prognosis.

Drug resistance makes treatment difficult in cancers. The present study identifies and analyzes drug resistance-related miRNA in colorectal cancer. We established 4 types of 5-fluorouracil (5-FU)-resistant colon cancer cell lines in vitro and in vivo. We then analyzed the miRNA expression profile by miRNA array in these 4 cell lines, and identified the drug resistance-related miRNAs. We examined the expression levels of the identified miRNA in 112 colorectal tumor samples from the patients. We identified 12 possible miRNAs involved in 5-FU resistance by miRNA arrays. We then examined the relationship between miR-31, which was the most promising among them, and drug resistance. The ectopic expression of mimic miR-31 showed significant 5-FU resistance in the parental DLD-1 cells, while anti-miR-31 caused significant growth inhibition in DLD/F cells; that is, 5-FU-resistant colon cancer cell line DLD-1 under exposure to 5-FU. When we exposed high doses of 5-FU to parent or 5-FU-resistant cells, the expression levels of miR-31 were raised higher than those of controls. Notably, the expression levels of miR-31 were positively correlated with the grade of clinical stages of colorectal tumors. The protein expression levels of factors inhibiting hypoxia-inducible factor 1 were downregulated by transfection of mimic miR-31 into DLD-1 cells. This study provides evidence supporting the association of miR-31 with 5-FU drug resistance and clinical stages of colorectal tumors.

In this issue of

The tumor microenvironment offers favorable conditions for tumor progression, and activated fibroblasts, known as cancer-associated fibroblasts, play a pivotal role. TP53-deficient cancer cells are known to induce strong fibroblast activation. We aimed to elucidate the oncogenic role of exosomes derived from TP53-deficient colon cancer cells in fibroblast proliferation and tumor growth. Cancer cell-derived exosomes (CDEs) were isolated from the conditioned media of cancer cells using a sequential ultracentrifugation method. The effects of exosomes on tumor growth were evaluated using human cell lines (TP53-WT colon cancer, HCT116; TP53-mutant colon cancer, HT29; and fibroblasts, CCD-18Co and WI-38) and an immune-deficient nude mouse xenograft model. HCT116 (HCT116

AIM: The present study was conducted to analyze the relationship between c-reactive protein (CRP) gene +1444C/T, 3407T/C (rs2808630) polymorphisms and colorectal cancer susceptibility.
METHODS: A total of 142 colorectal cancer patients and 127 healthy controls were recruited into this case-control study. The genotypes of CRP gene +1444C/T, rs2808630 polymorphisms were tested by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and the genotypes distributions of polymorphisms in controls was assessed whether conformed to Hardy-Weinberg equilibrium (HWE). The calculation of odds ratio (OR) with its 95% confidence interval (95% CI) is used for evaluating the association strength of gene polymorphism and disease.
RESULTS: Through the testing of χ
CONCLUSION: CRP rs2808630 polymorphism was related to the decreased risk of colorectal cancer, but not +1444C/T polymorphism.

BACKGROUND: A survival paradox of stage IIB/IIC and IIIA colon cancer has been consistently observed throughout revisions of the TNM system. This study aimed to understand this paradox with clinicopathological and molecular differences.
METHODS: Clinicopathological characteristics of patients with pathologically confirmed stage IIB/IIC or IIIA colon cancer were retrospectively reviewed from a database. Publicly available molecular data were retrieved, and intrinsic subtypes were identified and subjected to gene sets enrichment analysis (GSEA).
RESULTS: Among the 159 patients included in the clinicopathological analysis, those at stage IIB/IIC had worse 3-year disease-free and overall survival than those at stage IIIA (59.3% vs 91.7%, P < 0.001 and 82.7% vs 98.5%, P < 0.001, respectively), even after adjusting for confounding factors. Data of 95 patients were retrieved from public databases, demonstrating a higher frequency of the microsatellite instable subtype in stage IIB/IIC. The consensus molecular subtype distribution pattern differed between the groups. The GSEA further suggested the protumor inflammatory reaction might be more prominent in stage IIB/IIC.
CONCLUSIONS: The survival paradox in colon cancer was confirmed and appears to be a multifactorial phenomenon not attributed to a single clinicopathologic factor. However, the greater molecular heterogeneity in stage IIB/IIC could contribute to the poor prognosis.

Background: While microRNAs (miRNAs) are known to play a critical role in the progression of colorectal cancer, the role of miR-107 remains unknown. We evaluated its role and explored the underlying mechanism.
Materials & methods: MTT, wound-healing, transwell migration and transwell invasion assays were performed to evaluate the role of miR-107 in SW629 cell proliferation, migration and invasion. Real time-PCR and dual-luciferase reporter gene, TFR1 overexpression and western blotting assays were used to explore the underlying mechanism.
Results: MiR-107 is downregulated in colorectal cancer tissues and several human colorectal cancer cell lines. Low miR-107 expression often indicates a poor survival rate for colorectal cancer patients. MiR-107 suppresses the proliferation, migration and invasion of SW620 cells by negatively regulating transferrin receptor 1 (TFR1).
Conclusion: MiR-107 suppresses the metastasis of colorectal cancer and could be a potential therapy target in colorectal cancer patients.

Effective early screening and primary prevention is one of the major initiatives to decrease the morbidity and mortality of colorectal cancer in China. As a new non-invasive screening method for colorectal cancer in recent years, fecal DNA test detects colorectal cancer by analyzing gene mutations from intestinal tumor cells in the feces. The most widely used method among fecal DNA test is multi-target stoolDNA test (MT-sDNA). Many studies abroad on this emerging technique have been carried out to verify its high sensitivity, and it is gradually used in the clinic with continuous improvement and development of technology. Meanwhile, domestic MT-sDNA is still in the prototype stage, and more researches from Chinese population are needed. Compared with traditional screening methods, MT-sDNA technology has the advantages of non-invasiveness, painlessness and convenience. But its defects exist, such as high cost and low specificity. MT-sDNAis in accordance with precision medicine, and can largely make up for the shortcomings of traditional screening methods for colorectal cancer. It also holds a great promise for promoting the screening for colorectal cancer. This paper is aimed to discuss the application value of fecal DNA test by introducing its related researches at home and abroad,and summarizing its merits and demerits.

PURPOSE: The relationships of genetic variation in the vitamin D pathway with circulating 25-hydroxyvitamin D
METHODS: Among 535 patients participating in a randomized trial of chemotherapy for mCRC, we prospectively measured baseline plasma 25(OH)D and examined 124 tagging single-nucleotide polymorphisms (SNPs) within seven genes in the vitamin D pathway, including five SNPs associated with circulating 25(OH)D levels in previous genome-wide association studies (GWAS). We evaluated whether these SNPs were associated with plasma 25(OH)D levels and patient outcome (overall survival, time to progression, and tumor response), using linear, logistic, and Cox proportional hazards regression.
RESULTS: We observed a significant association between 25(OH)D levels and an additive genetic risk score determined by the five GWAS-identified SNPs (p = 0.0009). We did not observe any direct association between 25(OH)D-associated SNPs, individually or as a genetic risk score, and patient outcome. However, we found a significant interaction between 25(OH)D levels and rs12785878 genotype in DHCR7 on overall survival (p
CONCLUSION: Germline genetic variation in the vitamin D pathway informs baseline 25(OH)D levels among patients with mCRC. The association between 25(OH)D levels and overall survival may vary by DHCR7 genotype. ClinicalTrials.gov Identifier: NCT00003594 ( https://clinicaltrials.gov/ct2/show/NCT00003594 ).

MutYH-associated polyposis is the only polyposis syndrome with an autosomal recessive type of inheritance, often phenotypically similar to a weakened form of familial adenomatous polyposis. For the development of the disease mutations in both alleles of the gene are required, but an increased risk of developing colorectal cancer in carriers of monoallelic mutations is noted. The diagnosis of MutYH-associated polyposis should be suspected in a patient with colorectal cancer over 45 years old on the background of polyps in the colon. The review presents modern algorithms for diagnostic and treatment of the disease.

OBJECTIVE: Long non-coding RNAs (lncRNAs) and microRNAs (miRNAs) play essential roles in the tumour progression. LncRNAs mostly act as competing endogenous RNAs (ceRNAs) by sponging miRNAs. This study aimed to study the association of a novel lncRNA MFI2-AS1 with miR-574-5p/MYCBP axis in the development of colorectal cancer (CRC).
METHODS: Ninety-four CRC tissues and paired adjacent non-tumour tissues were included in our study. The relative expression level of MFI2-AS1 was detected, and its relationship with clinico-pathological factors was analysed. Then, the CRC cells lines (LoVo and RKO) were transfected with MFI2-AS1 siRNA, miR-574-5p mimics and inhibitors. Cell proliferation, migration, invasion, cell cycle distribution and DNA damage in response to different transfection conditions were examined. Dual-luciferase reporter assay was performed to identify the target interactions between MFI2-AS1 and miR-574-5p, miR-574-5p and MYCBP.
RESULTS: LncRNA MFI2-AS1 and MYCBP were up-regulated in CRC tissues when compared with adjacent non-tumour tissues. The expression levels of MFI2-AS1 were significantly associated with tumour histological grade, lymph and distant metastasis, TNM stage and vascular invasion. Both MFI2-AS1 siRNA and miR-574-5p mimics inhibited proliferation, migration and invasion in LoVo and RKO cells. The transfection of miR-574-5p inhibitor showed MFI2-AS1 siRNA-induced changes in CRC cells. Dual-luciferase reporter assay revealed target interactions between MFI2-AS1 and miR-574-5p, miR-574-5p and MYCBP.
CONCLUSIONS: These findings suggested that lncRNA MFI2-AS1 and MYCBP have promoting effects in CRC tissues. LncRNA MFI2-AS1 promoted CRC cell proliferation, migration and invasion through activating MYCBP and by sponging miR-574-5p.

Colorectal cancer (CRC) is a leading cause of cancer-related death worldwide, and has a strong heritable basis. We report a genome-wide association analysis of 34,627 CRC cases and 71,379 controls of European ancestry that identifies SNPs at 31 new CRC risk loci. We also identify eight independent risk SNPs at the new and previously reported European CRC loci, and a further nine CRC SNPs at loci previously only identified in Asian populations. We use in situ promoter capture Hi-C (CHi-C), gene expression, and in silico annotation methods to identify likely target genes of CRC SNPs. Whilst these new SNP associations implicate target genes that are enriched for known CRC pathways such as Wnt and BMP, they also highlight novel pathways with no prior links to colorectal tumourigenesis. These findings provide further insight into CRC susceptibility and enhance the prospects of applying genetic risk scores to personalised screening and prevention.

BACKGROUND: UGT2B7 was recently acknowledged as a new critical enzyme involved in biotransformation of a variety of carcinogens, whose function was reported to be significantly associated with its encoding gene (UGT2B7) polymorphisms. However, results regarding the associations between single nucleotide polymorphisms (SNPs) of UGT2B7 and cancer risk still remained controversial. Therefore, a meta-analysis was conducted to further elucidate the role of UGT2B7 SNPs on cancer susceptibilities.
METHODS: PubMed, EMBASE, Cochrane library, Chinese National Knowledge Infrastructure (CNKI), Technology of Chongqing (VIP) and Wan Fang Database were searched for eligible studies until March 2019. All analysis was carried out using the Review Manager 5.3 software. Subgroup analyses were performed by cancer types, ethnicity or source of controls.
RESULTS: 13 studies with a total of 7688 cancer cases and 11,281 controls were included in this meta-analysis. The results showed that UGT2B7 rs7439366 increased the colorectal cancer risk in dominant model (OR = 0.76, 95% CI = 0.61-0.95, P = 0.02). However, as for the rs7435335 and rs12233719, we did not find their associations with cancer risk in all genetic models. In addition, the rs7441774 was found to be associated with breast cancer risk and significantly reduced papillary thyroid cancer risk in rs3924194 was also observed. Nevertheless, these findings remained to be further proven in future studies since these 2 SNPs were only respectively involved in 1 study.
CONCLUSION: This meta-analysis confirmed the association of UGT2B7 rs7439366 with colorectal cancer risk, which may be a potential promising biomarker for prediction of colorectal cancer risk.

AIMS: MicroRNAs (miRNAs) are small noncoding RNAs that negatively control gene expression at the translational level. There are compelling evidences indicating that the expression of let-7e is downregulated in various cancers, however, the role of let-7e in colorectal cancer (CRC) and its mechanism has been remained unknown. Here, we investigated the potential role of let-7e in regulating CRC cells phenotypes.
MAIN METHODS: Let-7e and DCLK1 siRNA were transfected in HCT-116 cells. Colony formation assay, scratch test, Annexin V/PI flow cytometry, and sphere formation assay were performed to examine the cell proliferation, migration, apoptosis, and stemness, respectively. The expression of let-7e, epithelial-mesenchymal transition (EMT)-related genes, Doublecortin like kinase protein 1 (DCLK1), and cancer stem cells (CSCs) were assessed using RT-qPCR while the protein level of DCLK1 was determined by western blotting.
KEY FINDINGS: Overexpression of let-7e effectively inhibited cell proliferation, suppressed migration, reduced sphere formation, and precluded EMT process as well as stemness factors. Furthermore, let-7e suppressed DCLK1 expression. Additionally, we found that the expression of let-7e was negatively correlated with DCLK1 expression in CRC cells.
SIGNIFICANCE: Let-7e plays an important role as tumor suppressor miRNA in CRC probably through inhibition of DCLK1 expression.

INTRODUCTION: Recent advances in technology and research are rapidly changing the diagnostic approach to hereditary gastrointestinal cancer (HGIC) syndromes. Although the practice of clinical genetics is currently transitioning from targeted criteria-based testing to multigene panels, important challenges remain to be addressed. The aim of this study was to develop and technically validate the performance of a multigene panel for HGIC.
METHODS: CGT-colon-G14 is an amplicon-based panel designed to detect single nucleotide variants and small insertions/deletions in 14 well-established or presumed high-penetrance genes involved in HGIC. The assay parameters tested were sensitivity, specificity, accuracy, and inter-run and intra-run reproducibility. Performance and clinical impact were determined using 48 samples of patients with suspected HGIC/polyposis previously tested with the targeted approach.
RESULTS: The CGT-colon-G14 panel showed 99.99% accuracy and 100% inter- and intra-run reproducibility. Moreover, panel testing detected 1 actionable pathogenic variant and 16 variants with uncertain clinical impact that were missed by the conventional approach because they were located in genes not previously analyzed.
CONCLUSION: Introduction of the CGT-colon-G14 panel into the clinic could provide a higher diagnostic yield than a step-wise approach; however, results may not always be straightforward without the implementation of new genetic counseling models.