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Elimination of cancer stem cells (CSCs) and reinvigoration of antitumor immunity remain unmet challenges for cancer therapy. Tumor-associated macrophages (TAMs) constitute the prominant population of immune cells in tumor tissues, contributing to the formation of CSC niches and a suppressive immune microenvironment. Here, we report that high expression of inhibitor of differentiation 1 (ID1) in TAMs correlates with poor outcome in patients with colorectal cancer (CRC). ID1 expressing macrophages maintain cancer stemness and impede CD8 + T cell infiltration. Mechanistically, ID1 interacts with STAT1 to induce its cytoplasmic distribution and inhibits STAT1-mediated SerpinB2 and CCL4 transcription, two secretory factors responsible for cancer stemness inhibition and CD8 + T cell recruitment. Reducing ID1 expression ameliorates CRC progression and enhances tumor sensitivity to immunotherapy and chemotherapy. Collectively, our study highlights the pivotal role of ID1 in controlling the protumor phenotype of TAMs and paves the way for therapeutic targeting of ID1 in CRC., (© 2023. The Author(s).)

Protein-based cancer therapies are considered an alternative to conventional anticancer regimens, providing multifunctional properties while showing low toxicity. However, its widespread use is limited by absorption and instability issues, resulting in higher dosage requirements and a prolonged onset of bioactivity to elicit the desired response. Here, we developed a non-invasive antitumor treatment using designed ankyrin repeat protein (DARPin)-anticancer protein-conjugate that specifically targets the cancer biomarker, epithelial cell adhesion molecule (EpCAM). The DARPin-anticancer proteins bind to EpCAM-positive cancer cells and improve the in vitro anticancer efficacy by over 100-folds within 24 h, where the DARPin-tagged human lactoferrin fragment (drtHLF4) IC50 value is within the nanomolar range. Orally administered drtHLF4 was readily absorbed into the systemic flow of the HT-29 cancer murine model, exerting its anticancer effect on other tumors in the host body. Orally administered drtHFL4 cleared HT29-colorectal tumors using a single dose, whereas intratumoral injection cleared HT29-subcutaneous tumors within three doses. This approach addresses the limitations of other protein-based anticancer treatments by providing a non-invasive anticancer therapy with improved potency and tumor-specificity., Competing Interests: Conflict of interest statement The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 The Authors. Published by Elsevier Masson SAS.. All rights reserved.)

Background: The increasing number of young colorectal cancer (CRC) survivors has led to ongoing concerns about the risk of secondary primary malignancies (SPMs). Here, we intended to comprehensively explore the pooled standardized incidence rates (SIRs) for total and site-specific SPMs in CRC survivors with different restriction to lag period., Methods: Pubmed, Embase, Cochrane Library, and Web of science databases were searched to identify any studies reporting the SIRs of SPM following CRC until August 2021. Total and site-specific SIRs with different restriction to lag period were pooled using fixed/random effect models., Results: A total of 42 full-text publications with more than 1, 524, 236 CRC survivors and 166, 210 SPM patients were included in the meta-analysis. Pooled data showed an increased SIRs for all SPMs in CRC survivors with different restriction to lag period (no restriction to lag period, SIR = 1.15, 95% CI = [1.08-1.23]; 1-year lag, 1.16 [1.10-1.23]; 5-year lag, 1.18 [1.09-1.28]; 10-year lag, 1.24 [1.11-1.39]). The conclusions were consistent for neoplasms of colorectum, corpus uteri, and small intestine with different restriction to lag period. However, limited evidence was presented for associations between CRC survivors and SPM for prostate, breast (female), ovarian, stomach, urinary bladder, kidney, thyroid, bone and soft tissue., Conclusion: CRC survivors are associated with an increased risk of SPMs, especially neoplasms of colorectum, corpus uteri, and small intestine. Further studies should explore the risks for these neoplasms in CRC survivors, thus providing the reference for future follow-up care.

Background: Noninvasive diagnostic markers that are capable of distinguishing patients with colorectal cancer (CRC) from healthy individuals or patients with other cancer types are lacking. We report the discovery and validation of a panel of methylation-based markers that specifically detect CRC., Methods: This was a large-scale discovery study based on publicly available datasets coupled with a validation study where multiple types of specimens from six cohorts with CRC, other cancer types, and healthy individuals were used to identify and validate the tissue-specific methylation patterns of CRC and assess their diagnostic performance., Results: In the discovery and validation cohort (N = 9307), ten hypermethylated CpG sites located in three genes, C20orf194, LIFR, and ZNF304, were identified as CRC-specific markers. Different analyses have suggested that these CpG sites are CRC-specific hypermethylated and play a role in transcriptional silencing of corresponding genes. A random forest model based on ten markers achieved high accuracy rates between 85.7 and 94.3% and AUCs between 0.941 and 0.970 in predicting CRC in three independent datasets and a low misclassification rate in ten other cancer types. In the in-house validation cohort (N = 354), these markers achieved consistent discriminative capabilities. In the cfDNA pilot cohort (N = 14), hypermethylation of these markers was observed in cfDNA samples from CRC patients. In the cfDNA validation cohort (N = 155), the two-gene panel yielded a sensitivity of 69.5%, specificity of 91.7%, and AUC of 0.806., Conclusions: Hypermethylation of the ten CpG sites is a CRC-specific alteration in tissue and has the potential use as a noninvasive cfDNA marker to diagnose CRC., (© 2022. The Author(s).)

Increasing studies have highlighted the importance of ferroptosis in colorectal cancer (CRC). However, how to use ferroptosis-related genes (FRGs) to predict the prognosis and guide the treatment of CRC remains unknown. To build a prognostic prediction model using the GEO and TCGA databases and explored a therapeutic strategy for CRC patients based on FRGs. A total of 60 FRGs were identified and three of them including ACACA, GSS, and NFS1 were associated with the prognosis of CRC. Using Lasso regression analysis, an FRGs signature was constructed and validated as an independent prognostic predictor. Then we developed a nomogram based on the FRGs signature and clinical prognostic factors to predict the prognosis of CRC patients, which was better than the traditional TNM staging system. Single-sample gene set enrichment analysis (ssGSEA) was further performed for the functional analysis and suggested that JAK-STAT signaling, Ras signaling pathway, MAPK signaling pathway, and PI3K-Akt signaling pathway were significantly enriched in CRC patients with higher FRGs risk score. Interestingly, CRC cells with higher FRGs risk score were more sensitive to RSL3. Knocking down GSS and NFS1 increased the FRGs risk score and the sensitivity of CRC cells to RSL3. For the clinic use, we screened 75 FDA-approved cancer drugs and found that Fludarabine phosphate could decrease the expression of GSS and NFS1 most. Fludarabine phosphate, in combination with RSL3, showed a strong synergistic effect on CRC cells. Together, this study identified a potent prognostic model and provided an alternative individualized treatment for CRC patients.

Background: Colorectal cancer (CRC) represents a common malignancy in gastrointestinal tract. Iodine-125 ( 125 I) seed implantation is an emerging treatment technology for unresectable tumors. This study investigated the mechanism of 125 I seed in the function of CRC cells., Methods: The CRC cells were irradiated with different doses of 125 I seed (0.4, 0.6 and 0.8 mCi). miR-615 expression in CRC tissues and adjacent tissues was detected by RT-qPCR. miR-615 expression was intervened with miR-615 mimic or miR-615 inhibitor, and then the CRC cells were treated with 5-AZA (methylation inhibitor). The CRC cell growth, invasion and apoptosis were measured. The methylation level of miR-615 promoter region was detected. The xenograft tumor model irradiated by 125 I seed was established in nude mice. The methylation of miR-615, Ki67 expression and CRC cell apoptosis were detected., Results: 125 I seed irradiation repressed the growth and facilitated apoptosis of CRC cells in a dose-dependent manner. Compared with adjacent tissues, miR-615 expression in CRC tissues was downregulated and miR-615 was poorly expressed in CRC cells. Overexpression of miR-615 suppressed the growth of CRC cells. 125 I seed-irradiated CRC cells showed increased miR-615 expression, reduced growth rate and enhanced apoptosis. The methylation level of miR-615 promoter region in CRC cells was decreased after 125 I seed treatment. In vivo experiments confirmed that 125 I seed-irradiated xenograft tumors showed reduced methylation of the miR-615 promoter and increased miR-615 expression, as well as decreased Ki67 expression and enhanced apoptosis. The target genes of miR-615 and its regulatory downstream pathway were further predicted by bioinformatics analysis., Conclusions: 125 I seed repressed the growth and facilitated the apoptosis of CRC cells by suppressing the methylation of the miR-615 promoter and thus activating miR-615 expression. The possible mechanism was that miR-615-5p targeted MAPK13, thus affecting the MAPK pathway and the progression of CRC., (© 2022. The Author(s).)

High CD8 + T cell infiltration in colorectal cancer (CRC) should suggest a favorable prognosis and a satisfactory response to immunotherapy; however, the vast majority of patients with CRC do not benefit from immunotherapy due to poor T cell infiltration. Therefore, a better understanding of the mechanisms for T cell exclusion from CRC tumors is needed. Tribbles homolog 3 (TRIB3) has been implicated as an oncoprotein, but its role in regulating antitumor immune responses has not been defined. Here, we demonstrated that TRIB3 inhibits CD8 + T cell infiltration in various CRC mouse models. We showed that TRIB3 was acetylated by acetyltransferase P300, which inhibited ubiquitination and subsequent proteasomal degradation of TRIB3. Ectopically expressed TRIB3 inhibited signal transducer and activator of transcription 1 (STAT1) activation and STAT1-mediated CXCL10 transcription by enhancing the epidermal growth factor receptor signaling pathway, causing a reduction in tumor-infiltrating T cells. Genetic ablation of Trib3 or pharmacological acceleration of TRIB3 degradation with a P300 inhibitor increased T cell recruitment and sensitized CRCs to immune checkpoint blockade therapy. These findings identified TRIB3 as a negative modulator of CD8 + T cell infiltration in CRCs, highlighting a potential therapeutic target for treating immunologically “cold” CRCs.

We aim to identify a panel of differentially methylated regions (DMRs) for predicting survival outcomes for patients with CRC from the TCGA (n = 393). Four DMRs (MUC12, TBX20, CHN2, and B3GNT7) were selected as candidate prognostic markers for CRC. The prediction potential of selected DMRs was validated by the targeted bisulfite sequencing method in an independent cohort with 251 Chinese CRC patients. DMR methylation scores (DMSs) were constructed to evaluate the prognosis of CRC. Results of the validation cohort confirmed that higher DMSs were associated with poor overall survival (OS) of CRC, with hazard ratio (HR) value ranged from 1.445 to 2.698 in multivariable Cox models. Patients in the high prognostic index (high-PI) group showed a markedly unfavorable prognosis compared to the low-PI group in both TCGA discovery cohort (HR = 3.508, 95%CI: 2.196-5.604, P < 0.001) and independent validation cohort (HR = 1.912, 95%CI: 1.258-2.907, P = 0.002)., (Copyright © 2021. Published by Elsevier Inc.)

Diagnostic markers for both colorectal cancer (CRC) and its precursor lesions are lacking. Although aberrant methylation of the secretin receptor (SCTR) gene was observed in CRC, the diagnostic performance has not been evaluated. Therefore, this study aimed to assess and verify the diagnostic value of SCTR methylation of CRC and its precursor lesions through integrating the largest methylation data. The diagnostic performance of SCTR methylation was analyzed in the discovery set from The Cancer Genome Atlas (TCGA) CRC methylation data (N = 440), and verified in a large-scale test set (N = 938) from the Gene Expression Omnibus (GEO). Targeted bisulfite sequencing analysis was developed and applied to detect the methylation status of SCTR in our independent validation set (N = 374). Our findings revealed that the SCTR gene was frequently hypermethylated at its CpG islands in CRC. In the TCGA discovery set, the diagnostic score was constructed using 4 CpG sites (cg01013590, cg20505223, cg07176264, and cg26009192) and achieved high diagnostic performance (area under the ROC curve [AUC] = 0.964). In the GEO test set, the diagnostic score had robust diagnostic ability to distinguish CRC (AUC = 0.948) and its precursor lesions (AUC = 0.954) from normal samples. Moreover, hypermethylation of the SCTR gene was also found in cell-free DNA samples collected from CRC patients, but not in those from healthy controls. In the validation set, consistent results were observed using the targeted bisulfite sequencing array. Our study highlights that hypermethylation at CpG islands of the SCTR gene is a potential diagnostic biomarker in CRCs and its precursor lesions., (© 2020 The Authors. Cancer Science published by John Wiley & Sons Australia, Ltd on behalf of Japanese Cancer Association.)

Homogenous DNA methylation clearly affects clinical outcomes. However, less is known about the effects of heterogeneous methylation. We aimed to investigate the different effects between CASK promoter methylation heterogeneity and homogeneity on colorectal cancer (CRC) patients' prognosis. The methylation status of CASK in 296 tumor tissues and 255 adjacent normal tissues were evaluated using Methylation-sensitive high-resolution melting (MS-HRM). Digital MS-HRM (dMS-HRM) visualized heterogeneous methylation and subsequent sequencing provided exact patterns. Log-rank test and Cox regression model were adopted to assess the association between CASK methylation status and CRC prognosis with propensity score (PS) method to control confounding biases. Heterogeneous methylation was detected in both tumor (52.2%) and non-neoplastic tissue surrounding the tumor (62.4%). It occurred more frequently in lower levels of tumor invasion ( P = 0.002) and male patients ( P < 0.001). Compared with heterogeneous methylation, patients with CASK homogeneous methylation presented poorer overall survival (OS) (HR: 1.919, 95% CI: 1.146-3.212, P = 0.013) and disease-free survival (DFS) (HR: 1.913, 95% CI: 1.146-3.194, P = 0.013). This unfavorable effect still existed among older (≥ 50), Dukes staging C/D, and rectal cancer patients. MS-HRM and dMS-HRM when combined can assess the degree and complexity of heterogeneous methylation with a visible pattern.

Inactivation of Semaphorin 3F (SEMA3F) is involved in colorectal cancer development. However, the mechanism by which SEMA3F is regulated remains elusive. Deregulation of lncRNAs have been implicated in multiple human malignancies, including colorectal cancer (CRC). To date, it is still unclear whether and how lncRNA regulates SEMA3F expression and mediates CRC progression. Here we identify the oncogenic role of lncRNA FAM83C antisense RNA 1 (FAM83C-AS1) in CRC. FAM83C-AS1 is upregulated in tumor tissues and cells of CRC, which is negatively correlated with SEMA3F expression. Reciprocally, knockdown of FAM83C-AS1 exhibits inhibitory effects on the malignant transformation of CRC. Moreover, our data uncover that FAM83C-AS1 enhances methylation of SEMA3F promoter H3K27me3 via upregulating methyltransferase enhancer of zeste 2 polycomb repressive complex 2 subunit (EZH2). Specifically, FAM83C-AS1 stabilizes EZH2 protein through recruiting the zinc finger RANBP2-type containing 1 (ZRANB1). Both in vitro and in vivo rescue assays exhibit that SEMA3F is dispensable for the tumor-promoting effects of FAM83C-AS1 on CRC progression. Our data thus demonstrate that the epigenetic role of FAM83C-AS1 in suppression of SEMA3F expression through stabilization of EZH2 to drive CRC progression, which may be conducive to discovering novel therapeutic targets for the treatment of CRC.

Cancer-derived exosomal miRNAs play an important role in the development of metastasis, but the effects and underlying mechanisms remain unclear. In the present study, we investigated the miRNA expression profiles of 5 paired serum exosomal samples from metastatic colorectal cancer (mCRC) and non-mCRC patients via RNA sequencing. After we evaluated the differentially expressed miRNAs in 80 CRC patients, miR-106b-3p was selected as a metastasis-associated miRNA of CRC. We showed that the expression level of serum exosomal miR-106b-3p was significantly higher in CRC patients with metastasis than those without metastasis. Additionally, high serum exosomal miR-106b-3p expression in patients was correlated with a poor prognosis. Coculture of low-metastatic CRC cells with high-metastatic CRC cell-derived exosomes promoted cell migration, invasion, and epithelial-to-mesenchymal transition (EMT), which was caused by the transport and transduction of miR-106b-3p in vitro. Moreover, exosomal miR-106b-3p promoted lung metastasis of CRC cells in vivo. In addition, we demonstrated that miR-106b-3p regulated metastasis by targeting deleted in liver cancer-1 (DLC-1). A negative correlation was also identified between miR-106b-3p and DLC-1 expression in human CRC tumour tissues and in mouse lung metastatic lesions. Collectively, our study indicated that metastasis-associated miR-106b-3p from serum exosomes could be used as a potential prognostic biomarker and therapeutic target for CRC patients., (© 2020 The Author(s).)

Colorectal cancer (CRC) is a prevalent malignant tumour that causes considerable cancer-related deaths globally. The sphingolipid transporter 2 (SPNS2), a sphingosine-1-phosphate (S1P) transporter, modulates multiple biological events including malignancy of cancer cells. In this study, the effects of SPNS2 on CRC progression were studied. We found that SPNS2 expression was significantly upregulated in CRC tissues compared to that in adjacent non-tumour tissues. To assess the role of SPNS2 in CRC cells, we performed loss- and gain-of-function experiments in SW480 and HCT116 cells, respectively. The results demonstrated that SPNS2 promoted proliferation, migration and invasion, and inhibited apoptosis in CRC cells. Additionally, SPNS2 enhanced the release of intracellular S1P, and increased S1P receptor 1 (S1PR1) and S1PR3 expression. Moreover, SPNS2 activated the Akt and ERK pathways, and the biological behaviours of SPNS2 were attenuated by Akt or ERK inhibitor in HCT116 cells. In conclusion, our results demonstrated that SPNS2 promoted proliferation, migration and invasion, and inhibited apoptosis by regulating S1P/S1PR1/3 axis and activating Akt and ERK pathway in CRC cells., (© 2019 John Wiley & Sons Australia, Ltd.)

The metabolic profiling of biofluids using untargeted metabolomics provides a promising choice to discover metabolite biomarkers for clinical cancer diagnosis. However, metabolite biomarkers discovered in biofluids may not necessarily reflect the pathological status of tumor tissue, which makes these biomarkers difficult to reproduce. In this study, we developed a new analysis strategy by integrating the univariate and multivariate correlation analysis approach to discover tumor tissue derived (TTD) metabolites in plasma samples. Specifically, untargeted metabolomics was first used to profile a set of paired tissue and plasma samples from 34 colorectal cancer (CRC) patients. Next, univariate correlation analysis was used to select correlative metabolite pairs between tissue and plasma, and a random forest regression model was utilized to define 243 TTD metabolites in plasma samples. The TTD metabolites in CRC plasma were demonstrated to accurately reflect the pathological status of tumor tissue and have great potential for metabolite biomarker discovery. Accordingly, we conducted a clinical study using a set of 146 plasma samples from CRC patients and gender-matched polyp controls to discover metabolite biomarkers from TTD metabolites. As a result, eight metabolites were selected as potential biomarkers for CRC diagnosis with high sensitivity and specificity. For CRC patients after surgery, the survival risk score defined by metabolite biomarkers also performed well in predicting overall survival time ( p = 0.022) and progression-free survival time ( p = 0.002). In conclusion, we developed a new analysis strategy which effectively discovers tumor tissue related metabolite biomarkers in plasma for cancer diagnosis and prognosis.

Background & Aims: Activation of Wnt signaling to β-catenin contributes to the development of colorectal cancer (CRC). Expression of tribbles pseudo-kinase 3 (TRIB3) is increased in some colorectal tumors and associated with poor outcome. We investigated whether increased TRIB3 expression promotes stem cell features of CRC cells and tumor progression by interacting with the Wnt signaling pathway., Methods: We performed studies with C57BL/6J-Apc Min /J mice injected with an adeno-associated virus vector that expresses a small hairpin RNA against Trib3 mRNA (Apc Min /J-Trib3 KD ) or a control vector (Apc Min /J-Ctrl). We created BALB/c mice that overexpress TRIB3 from an adeno-associated virus vector and mice with small hairpin RNA-mediated knockdown of β-catenin. The mice were given azoxymethane followed by dextran sodium sulfate to induce colitis-associated cancer. Intestinal tissues were collected and analyzed by histology, gene expression profiling, immunohistochemistry, and immunofluorescence. Leucine-rich repeat-containing G-protein-coupled receptor 5 (LGR5)-positive (LGR5 Pos ) and LGR5-negative (LGR5 Neg ) HCT-8 CRC cells, with or without knockdown or transgenic expression of TRIB3, were sorted and analyzed in sphere-formation assays. We derived organoids from human and mouse colorectal tumors to analyze the function of TRIB3 and test the effect of a peptide inhibitor. Wnt signaling to β-catenin was analyzed in dual luciferase reporter, chromatin precipitation, immunofluorescence, and immunoblot assays. Proteins that interact with TRIB3 were identified by immunoprecipitation. CRC cell lines were grown in nude mice as xenograft tumors., Results: At 10 weeks of age, more than half the Apc Min /J-Ctrl mice developed intestinal high-grade epithelial neoplasia, whereas Apc Min /J-Trib3 KD mice had no intestinal polyps and normal histology. Colon tissues from Apc Min /J-Trib3 KD mice expressed lower levels of genes regulated by β-catenin and genes associated with cancer stem cells. Mice with overexpression of Trib3 developed more tumors after administration of azoxymethane and dextran sodium sulfate than BALB/c mice. Mice with knockdown of β-catenin had a lower tumor burden after administration of azoxymethane and dextran sodium sulfate, regardless of Trib3 overexpression. Intestinal tissues from mice with overexpression of Trib3 and knockdown of β-catenin did not have activation of Wnt signaling or expression of genes regulated by β-catenin. LGR5 Pos cells sorted from HCT-8 cells expressed higher levels of TRIB3 than LGR5 Neg cells. CRC cells that overexpressed TRIB3 had higher levels of transcription by β-catenin and formed larger spheroids than control CRC cells; knockdown of β-catenin prevented the larger organoid size caused by TRIB3 overexpression. TRIB3 interacted physically with β-catenin and transcription factor 4 (TCF4). TRIB3 overexpression increased, and TRIB3 knockdown decreased, recruitment of TCF4 and β-catenin to the promoter region of genes regulated by Wnt. Activated β-catenin increased expression of TRIB3, indicating a positive-feedback loop. A peptide (P2-T3A6) that bound β-catenin disrupted its interaction with TRIB3 and TCF4. In primary CRC cells and HCT-8 cells, P2-T3A6 decreased expression of genes regulated by β-catenin and genes associated with cancer stem cells and decreased cell viability and migration. Injection of C57BL/6J-Apc Min /J mice with P2-T3A6 decreased the number and size of tumor nodules and colon expression of genes regulated by β-catenin. P2-T3A6 increased 5-fluorouracil-induced death of CRC cells and survival times of mice with xenograft tumors., Conclusion: TRIB3 interacts with β-catenin and TCF4 in intestine cells to increase expression of genes associated with cancer stem cells. Knockdown of TRIB3 decreases colon neoplasia in mice, migration of CRC cells, and their growth as xenograft tumors in mice. Strategies to block TRIB3 activity might be developed for treatment of CRC., (Copyright © 2019 AGA Institute. Published by Elsevier Inc. All rights reserved.)

GNA13 has been found overexpressed in various types of cancer, which is related to tumor metastasis and progression. However, the biological functions of GNA13 in colorectal cancer (CRC) progression remain unclear. This study aimed to explore the role of GNA13 in CRC and investigate the mechanism of how GNA13 promotes tumor growth. Interestingly, our findings showed that GNA13 is commonly upregulated in CRC, where these events are associated with a worse histologic grade and poor survival. Increased expression levels of GNA13 promoted cell growth, migration, invasion, and epithelial-mesenchymal transition, whereas GNA13 silencing abrogated these malignant phenotypes. In addition, overexpressing GNA13 in cancer cells increased the levels of the chemokines CXCL1, CXCL2, and CXCL4, which contributed to CRC proliferation and colony formation. Moreover, our mechanistic investigations suggest that the NF-κB/p65 signaling pathway was activated by the increase in GNA13 levels. Inhibiting the NF-κB/p65 pathway with an inhibitor decreased GNA13-induced migration, invasion and CXCL chemokine level increases, indicating the critical role of NF-κB/p65 signaling in mediating the effects of GNA13 in CRC. Together, these results demonstrate a key role of GNA13 overexpression in CRC that contributes to malignant behavior in cancer cells, at least in part through stimulating angiogenesis and increasing the levels of the NF-κB-dependent chemokines CXCL1, CXCL2, and CXCL4., (© 2018 The Authors. Cancer Medicine published by John Wiley & Sons Ltd.)

CYP24A1 and CYP27B1 are critical genes determining 1α,25(OH) 2 D 3 concentration and impacting on carcinogenesis. A case-control study including 528 colorectal cancer (CRC) patients and 605 cancer-free controls and a follow-up study with 317 cases were conducted in northeast China. Genotypes were tested by TaqMan Genotyping Assays. Individuals carrying the GG genotype of CYP27B1 G > T (rs10877012) exhibited decreased CRC risk compared with those with the TT genotype (OR adjusted (OR adj ) = 0.57, 95% Confidence Interval (CI) = 0.38-0.84). Compared with the TT genotype, a significant association between the CC genotype of CYP27B1 C > T (rs4646536) and a reduced risk of CRC was observed (OR adj  = 0.59, 95% CI = 0.40-0.88). We also observed significant combined effects of the two polymorphisms in CYP27B1 with dietary factors, including the intake of cereals, overnight meal, allium vegetables, pork, canned fruit, and braised fish, on CRC risk. These associations remained significant after Bonferroni correction for multiple comparisons. The Hazard Ration (HR) of patients with the AA genotype (CYP24A1 A > G, rs4809957) was 2.38 (95% CI = 1.30-4.37) when compared with the GG genotype. Thus, our findings suggested that two polymorphisms in CYP27B1 are associated with CRC susceptibility. CYP24A1 A > G (rs4809957) polymorphism may lead to a worse prognosis of CRC.

The four-transmembrane protein MAL2 and tumor protein D52 (TPD52) have been shown to be involved in tumorigenesis of various cancers. However, their roles in colorectal cancer (CRC) remain unclear. In this study, we explored the expressions of MAL2 and TPD52 in tumor specimens resected from 123 CRC patients and the prognostic values of the two proteins in CRC. Immunohistochemical analyses showed that MAL2 (P<0.001) and TPD52 (P<0.001) were significantly highly expressed in primary carcinoma tissues compared with adjacent non-cancerous mucosa tissues. And TPD52 exhibited frequent overexpression in liver metastasis tissues relative to primary carcinoma tissues (P = 0.042), while MAL2 in lymphnode and liver metastasis tissues showed no significant elevation. Real-time quantitative PCR (RT-qPCR) showed the identical results. Correlation analyses by Pearson's chi-square test demonstrated that MAL2 in tumors was positively correlated with tumor status (pathological assessment of regional lymph nodes (pN, P = 0.024)), and clinic stage (P = 0.017). Additionally, the expression of TPD52 was detected under the same condition and was shown to be positively correlated withtumor status (pathological assessment of the primary tumor (pT, P = 0.035), distant metastasis (pM, P = 0.001)) and CRC clinicopathology(P = 0.024). Kaplan-Meier survival curves indicated that positive MAL2 (P<0.001) and TPD52 (P<0.001) expressions were associated with poor overall survival (OS) in CRC patients. Multivariate analysis showed that MAL2 and TPD52 expression was an independent prognostic factor for reduced OS of CRC patients. Moreover, overexpression of TPD52 in CRC SW480 cells showed an increased cell migration (P = 0.023) and invasion (P = 0.012) through inducing occurrence of epithelial-mesenchymal transition (EMT) and activating focal adhesion kinase (FAK)-mediated integrin signalling and PI3K⁄Akt signalling.Whereas TPD52-depleted cells showed the reverse effect. These data suggested that MAL2 and TPD52 might be potential biomarkers for clinical prognosis and might be a promising therapeutic target for CRC.

Ubiquitin specific peptidase 22 (USP22), a putative cancer stem cell marker, is overexpressed in liver metastases of colorectal cancer (CRC). However, the mechanism by which USP22 promotes CRC metastasis remains largely unknown. Here, we report that USP22 and AP4 are simultaneously overexpressed during TGF-β1-induced CRC cell epithelial-mesenchymal transition (EMT). USP22 up-regulation enhances CRC cell migration and invasion and EMT-related marker and AP4 expression, but these effects are partly blocked by AP4 knockdown. In addition, USP22 binds to the promoter region of AP4 to activate its transcription. In vivo, elevated USP22 expression promotes CRC cell metastasis to the lungs in nude mice, as evidenced by the fact that CRC metastatic nodules stain deeply positive for USP22 and AP4. In human CRC tissues, the genes encoding USP22 and AP4 are overexpressed in metastatic liver lesions compared with primary cancer tissues, and their overexpression is significantly associated with poor CRC patient survival. These findings indicate that USP22 and AP4 may serve as prognostic markers for predicting the risk of developing distant metastases in CRC.

Colorectal cancer, the third most common cancer in both men and women, has gradually increased in recent years. MYSM1has been investigated as a regulator of hematopoiesis and lymphocyte development in human. It has been reported that some tumor-related genes were modulated by MYSM1. However, its exact role in cancer development remains unclear. Herein, we aimed to examine the expression level of MYSM1 in tumor tissues and its correlation with clinicopathology and survivals of patients with colorectal cancer (CRC).MYSM1expressions in tumor specimens resected from 123 CRC patients were detected by immunochemistry and Western blot analysis. The results showed that MYSM1 was significantly highly expressed in carcinoma tissues compared with adjacent normal mucosa tissues (P<0.05). Correlation analyses by Pearson's chi-square test demonstrated that MYSM1 in tumors was positively correlated with tumor status (pathological assessment of the primary tumor (pT, P<0.001), regional lymph nodes (pN, P = 0.013), distant metastasis (pM, P<0.001)) and clinic stage (P<0.001); Whereas, MYSM1 was not associated with tumor size of CRC patients and was positively associated with tumor differentiation grade (P = 0.015). Patients with positiveMYSM1expression showed poor survival compared with the MYSM1 negative group (P<0.001).Simultaneously, multivariate Cox regression analysis indicated thatMYSM1 expression in tumor cells was an independent factor for reduced overall survival in CRC patients (P<0.001).Additionally,MYSM1 in CRC SW480 cells was silenced by small interference RNA (siRNA) technology. Scratch assay and Transwell assay showed that MYSM1 silencing decreased migration and invasion abilities of SW480 cells. These data suggested that expression of MYSM1 was associated with the progression of CRC and might be a potential biomarker for clinical prognosis.

Ephrin Type-A Receptor 3 (EphA3) belongs to the ephrin receptor subfamily of the protein tyrosine kinase family, and plays an important role in embryogenesis and neurogenesis. This study aimed to investigate the role of EphA3 in promoting malignant transformation of colorectal epithelial cells, and explore underlying molecular mechanisms. Colorectal cancer tissue specimens from 68 patients were analyzed for EphA3 expression. EphA3 expression levels were manipulated in rat colon epithelial cell lines. We found that EphA3 expression level in tumor tissues was associated with patient age (P = 0.015), tumor differentiation (P = 0.001), and lymph node metastasis (P = 0.039). Overexpression of EphA3 and its constitutively active mutants promoted colony formation, migration and invasion, and tumorigenicity of colon epithelial cells in nude mice. The cDNA and lncRNA microarray profiling data revealed that differentially expressed genes and lncRNAs in EphA3 or mutant-transfected cells were associated with cell proliferation, invasion and angiogenesis. Our findings reveal the mechanisms underlying the oncogenic activities of EphA3 in colorectal cells, which could provide novel targets for the prevention, early diagnosis, and treatment of colorectal cancer., (Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.)

The relationship between the DNA methylation status of the CpG islands of multiple genes in blood leukocytes in CRC susceptibility and prognosis, as well as possible interactions with dietary factors on CRC risk are unclear. We carried out a case-control study including 421 CRC patients and 506 controls to examine the associations between six genes (AOX-1, RARB2, RERG, ADAMTS9, IRF4, and FOXE-1), multiple CpG site methylation (MCSM) and susceptibility to CRC. High-level MCSM (MCSM-H) was defined as methylation of greater than or equal to 2 of 5 candidate genes (except for RARB2); low-level MCSM (MCSM-L) was when 1 candidate gene was methylated; non-MCSM was when none of the candidate genes were methylated. Blood cell-derived DNA methylation status was detected using methylation-sensitive high-resolution melting analysis. The hypermethylation status of each individual gene was statistically significantly associated with CRC. MCSM status was also associated with CRC (OR = 1.54, 95% CI: 1.15-2.05, P = 0.004). We observed interactions between a high level of dietary intake of cereals, pungent food, and stewed fish with brown sauce, age (older than 60 yrs), smoking and hypermethylation on risk of CRC. MCSM in peripheral blood DNA may be an important biomarker for susceptibility to CRC.

The erythropoietin-producing hepatocyte (Eph) family tyrosine kinases play important roles in tumorigenesis and cancer aggression. In this study, we investigated the role of EphB6 in oncogenic transformation of colorectal epithelial cells in vitro and in vivo. EphB6 is upregulated in human colorectal cancer (CRC) tissues as compared to normal tissues, and its overexpression promotes proliferation, migration and invasion by IMCE colorectal adenoma cells, in which one Apc allele is mutated. EphB6 overexpression together with Apc mutation leads to the development of colorectal tumors in vivo. Expression microarrays using mRNAs and lncRNAs isolated from EphB6-overexpresssing IMCE and control cells revealed a large number of dysregulated genes involved in cancer-related functions and pathways. The present study is the first to demonstrate that EphB6 overexpression together with Apc gene mutations may enhance proliferation, invasion and metastasis by colorectal epithelial cells. Microarray data and pathway analysis of differentially expressed genes provided insight into possible EphB6-regulated mechanisms promoting tumorigenesis and cancer progression. EphB6 overexpression may represent a novel, effective biomarker predictive of cell proliferation, invasion and metastasis patterns in CRC tumors., Competing Interests: The authors declare that they have no conflicts of interest.

Purpose: T lymphocyte immune responses are controlled by both co-stimulatory and co-inhibitory signaling through T cell co-receptors. Cytotoxic T lymphocyte antigen-4 (CTLA-4), programmed death 1 (PD-1) and B and T lymphocyte attenuator (BTLA) are all co-inhibitory molecules that negatively regulate the activation of T cells. In this study, we investigated the relationship between ten tagging SNPs in three co-inhibitory molecule genes and colorectal cancer (CRC)., Methods: We conducted a hospital-based case-control study consisting of 601 cases with CRC and 627 CRC-free individuals from the Heilongjiang Province of China., Results: The rs7421861 CT genotype was significantly associated with the risk of colorectal cancer compared to the wild-type TT genotype (adjusted OR 1.314, 95% CI 1.012-1.706, P = 0.041). The rs2705535 TT genotype was associated with the risk of rectal cancer [OR 1.819 (1.093-3.027), P = 0.021]. There was statistical interaction between the PD-1/rs2227982 (CT + TT) genotypes and high seafood intake (>once/week), as well as the CTLA-4/rs231777 variant and high pungent food intake (>3 times/week). The AG + AA genotypes of CTLA-4/rs3087243 statistically and antagonistically interacted with soybeans, pork and alcohol intake and were associated with CRC risk. Analogously, BTLA/rs1844089 interacted with pork intake, PD-1/rs7421861 with beef and lamb consumption and PD-1/rs6710479 with barbecue consumption. Haplotype G-C-G-A-T-T-A was significantly associated with CRC risk (OR 1.221 P = 0.034)., Conclusions: These data indicate potential associations between BTLA and PD-1 polymorphisms and CRC susceptibility. Additionally, the three co-inhibitory molecule gene SNPs have environmental interactions associated with CRC risk.

Purpose: Given that mismatch repair (MMR) system plays an important role in recognizing and removing insertion/deletion mutations which occur during DNA replication, common variants associated with impaired MMR system may thus increase risk of colorectal cancer (CRC). Therefore, we aimed to demonstrate the associations between common variants in two MMR genes (hMLH1 and hMSH2) and CRC risk., Methods: We genotyped 10 intronic/promoter single-nucleotide polymorphisms (SNPs) of hMLH1 and hMSH2 in 451 CRC patients and 630 controls. Associations between genotypes and CRC risk were estimated using odds ratios and 95 % confidence intervals. Gene-gene interactions, as well as gene-environment interactions on CRC risk were also investigated., Results: We found that IVS15-214T>C and IVS11 + 107A>G of hMSH2 were significantly associated with CRC risk. In dominant model, variant carriers of the two SNPs could decrease risk of CRC by 31 % (ORadj = 0.69, 95 % CI 0.53-0.91, p < 0.01) and 33 % (ORadj = 0.67, 95 % CI 0.47-0.95, p = 0.02), respectively. In addition, IVS7-212T>A, IVS11+183A>G and IVS8+719T>C of hMSH2 were associated with the susceptibility to colon cancer rather than rectal cancer. ATTTGGGT and TCTTAGAC haplotypes were associated with 44 and 45 % decreased risk of CRC, respectively, while ATTTGAGT and TTTCAGAC haplotypes were associated with 1.37-fold and 2.49-fold increased risk of CRC, respectively. There was a significant three-way gene-gene interaction among hMSH2 IVS11+107A>G, IVS11+183A>G and IVS8+719T>C (p < 0.01). Significant gene-environment interactions were observed between hMSH2 IVS15-214T>C and IVS11+107A>G and cereals consumption (both with p < 0.01)., Conclusions: Our findings suggested that intronic SNPs, gene-gene and gene-environment interactions in hMSH2 might be associated with susceptibility to CRC.

Limited studies about the effects of TLR 4 and IL17 polymorphisms (SNPs) on the risk of colorectal cancer (CRC) have yielded inconsistent results. Totally, 601 CRC patients and 627 controls were enrolled. Unconditional logistic regression was used to estimate the association between tagSNPs and susceptibility of CRC and the interactions effects of gene and environment on the risk of CRC. IL17 rs6973569 AG and AG/AA genotypes significantly decreased the risk of CRC compared with GG genotype (ORadjusted=0.72, 95% CI 0.55-0.94 and ORadjusted=0.74, 95 % CI 0.57-0.97). The haplotype G-T-G-C-A-G accounting for the largest proportion haplotypes increased the risk of CRC (OR=1.27, 95 % CI 1.06-1.53). However, G-C-C-T-A-G and G-C-G-C-A-G haplotypes decreased the susceptibility of CRC. Synergistic interactions between TLR 4 rs1927911 CT/TT and higher pungent food intake as well as IL17 rs6973569 AG/AA genotypes and higher intake of sausage food (ORi=1.72, 95% CI 1.04-2.84 and ORi=3.38, 95% CI 1.28-8.91) on the risk of CRC were observed. IL17 rs6973569 SNP might be an independent factor of susceptibility to CRC. TLR 4 haplotype of G-T-G-C-A-G may increase risk of CRC. Higher intake of pungent and sausage food synergistically interacted with TLR 4 and IL17 SNPs on the risk of CRC.

Foxp3+ regulatory T cells (Tregs) and natural killer group 2, member D (NKG2D)-positive natural killer (NK) cells are considered to be important in the immune escape of colorectal cancer (CRC). However, the association between these two variables remains obscure. Therefore, in the present study, the levels of peripheral Tregs and NKG2D expression in NK cells and the associations in CRC patients were investigated. A total of 35 CRC patients and 16 healthy controls were enrolled in this study. Flow cytometry was performed to assay Treg numbers and NKG2D expression levels in NK cells in peripheral blood samples. Serum carcino-embryonic antigen (CEA) protein was assayed by electrochemiluminescence. Peripheral Treg numbers were significantly increased (P<0.05), while NKG2D expression levels in NK cells were significantly reduced (P<0.01) in CRC patients compared with healthy controls. However, no significant differences were identified in Treg numbers between CRC patients with and without lymph node metastases and between CRC patients with different clinical stages of CRC. Similarly, no significant differences were detected in NKG2D expression levels in NK cells between the different patient groups. Statistical analysis revealed that increased Treg numbers were not correlated with reduced NKG2D expression levels in NK cells from CRC patients. In addition, no statistical correlation was observed between Treg numbers and serum CEA protein in CRC patients. In conclusion, the upregulation of Tregs was not significantly correlated with the downregulation of NKG2D expression in NK cells in peripheral blood from CRC patients.

No study in China has focused on the relationships between germline and somatic hMLH1/hMSH2 gene mutations, hMLH1 promoter methylation, and the prognosis of colorectal cancer (CRC), especially in sporadic CRC. Therefore, we carried out this study with 433 primary sporadic CRC patients to investigate the associations between germline and somatic hMLH1/hMSH2 gene mutations, hMLH1 promoter methylation, and the overall survival (OS) of CRC; to evaluate the effect of interaction between gene mutation and methylation on the risk of CRC prognosis. As a result, the 3-, 5-, and 7-year survival of the sporadic CRC patients was 67, 57, and 50.0 %, respectively. There were no significant associations observed between germline and somatic hMLH1/hMSH2 gene mutations after adjusted (HR = 1.37, 95 % CI 0.70-2.67, p = 0.35; HR = 1.31, 95 % CI 0.69-2.47, p = 0.42, respectively). When the analyses were stratified based on tumor stage, tumor location, and chemotherapy, no significant survival advantage of hMLH1/hMSH2 gene mutation was illustrated. In addition, no significant association between germline and somatic hMLH1 promoter methylation and OS of CRC was observed (HR = 1.46, 95 % CI 0.57-3.74, p = 0.43; HR = 0.70, 95 % CI 0.32-1.53, p = 0.37, respectively). In conclusion, the research did not find the significant association between germline and somatic hMLH1/hMSH2 gene mutations, hMLH1 promoter methylation, and sporadic CRC prognosis.

We aimed to investigate the associations between single-nucleotide polymorphisms (SNPs) in two mismatch repair genes (hMLH1 and hMSH2) and colorectal cancer (CRC) prognosis in Northeast China. We genotyped 387 patients for 10 SNPs in hMLH1 and hMSH2, using polymerase chain reaction restriction fragment length polymorphism approach. Associations between genotypes and overall survival (OS) were estimated using hazard ratios (HRs) and 95 % confidence intervals (CIs). Two SNPs of hMLH1 (hMLH1 -93G>A and IVS3-1403A>T) were significantly associated with OS of CRC in dominant model and recessive model, respectively. For hMLH1 -93G>A, the adjusted HR equaled 0.66 (95 % CI 0.45-0.99, p = 0.04). As for hMLH1 IVS3-1403A>T, the adjusted HR equaled 1.90 (95 % CI 1.14-3.17, p = 0.01). When stratified by tumor location, hMLH1 -93G>A and IVS3-1403A>T were associated with colon cancer survival (for hMLH1 -93G>A, AA+AG vs. GG, HRadj = 0.34, 95 % CI 0.17-0.68, p < 0.01; for hMLH1 IVS3-1403A>T, AT vs. AA, HR(adj) = 2.20, 95 % CI 1.11-4.36, p = 0.02), rather than rectal cancer. None of SNPs located at hMSH2 were significantly associated with prognosis of CRC. Our findings suggested that common variants in hMLH1 may serve as a predictor of CRC survival.

Cyclooxygenase-2 (COX-2), 12-lipoxygenase (12-LOX) and phospholipaseA2 (PLA2) played important roles in the modulation of apoptosis, angiogenesis, carcinogenesis and invasion of colorectal cancer (CRC). The polymorphisms in COX-2, 12-LOX and PLA2 may affect their roles. Therefore, we investigated if COX-2 -1195G > A, 12-LOX 261Arg > Gln and PLA2 c.349 + 191A > G polymorphisms were associated with risk and prognosis of CRC as well as possible interactions with the environmental factors on the risk of CRC in Northeast of China. A case-control study with 451 cases and 631 controls were carried out, a cohort with 386 patients were followed up. Genotypes were determined by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). Compared with the 261Arg/Arg genotype, 12-LOX 261Arg/Gln genotype and 261Arg/Gln + Gln/Gln genotypes reduced the risk of rectal cancer by 33% (adjusted OR = 0.67, 95% CI 0.47-0.97, p = 0.03) and 32% (adjusted OR = 0.68, 95% CI 0.49-0.96, p = 0.03), respectively. The adjusted HR for the association between 12-LOX 261Gln/Gln genotype and overall survival in patients with CRC was 1.68 (95% CI 1.06-2.68, p = 0.03). There was also evidence of an interaction between the PLA2 c.349 + 191 A > G genotypes and the overnight food consumption (adjusted ORi = 1.92, 95% CI 1.14-3.25, P(interaction) = 0.01). These observations indicate that 12-LOX 261Arg > Gln polymorphism may affect risk of rectal cancer, and it may be a potential predictive marker for prognosis of CRC.

Objective: The current study is to evaluate the effect of thymidylate synthase (TYMS) on lymph node metastasis (LNM) in Chinese colorectal cancer (CRC) patients, and develop potential LNM-associated biomarkers for CRC., Design and Methods: Differences in TYMS gene expression between primary CRC with LNM (LNM CRC) and without LNM (non-LNM CRC) were assessed using quantitative real-time PCR analysis in 100 Chinese colorectal cancer patients. The relationship between clinicopathological parameters and prognosis of candidate biomarkers was also examined in the experiment., Results: TYMS was significantly upregulated in LNM CRC compared with non-LNM CRC, which was confirmed by real-time quantitative polymerase chain reaction. Overexpression of TYMS was significantly associated with LNM (P<0.001), advanced TNM stage (P<0.001), increased 5-year recurrence rate (P<0.001) and decreased 5-year overall survival rate (P<0.001). Univariate and multivariate analyses indicated that TYMS expression was an independent prognostic factor for recurrence and survival of CRC patients (P<0.05)., Conclusions: TYMS effect on lymph node metastasis in CRC might serve as a potential biomarker for LNM and a prognostic factor in CRC. Over-expression of TYMS is a predicting factor to the poor outcome in clinical colorectal cancer patients., (© 2013. Published by Elsevier Inc. All rights reserved.)

Base excision repair (BER) pathway plays critical role in maintaining genome integrity. Polymorphisms in BER genes which modulate the DNA repair capacity may affect the susceptibility and prognosis of cancer. We conducted a case-control study and followed up the cases to explore the associations between BER genes polymorphisms and the risk and prognosis of colorectal cancer (CRC). This study included 451 CRC patients and 631 controls. Four single-nucleotide polymorphisms (SNPs) in genes of apurinic/apyrimidinic endonuclease-1 (APE1), ADP-ribosyltransferase (ADPRT, also known as PARP1), and X-ray repair cross-complementing groups 1 (XRCC1) were tested by PCR-RFLP. Odds ratio (OR), hazard ratio (HR), and their 95 % confidence intervals (CIs) were calculated by unconditional logistic regression and Cox proportional hazard model. PARP1 762 recessive model (OR = 1.57, 95 % CI 1.12-2.20) and XRCC1 194 dominant model (OR = 1.45, 95 % CI 1.12-1.88) were associated with increased CRC risk. A significant increasing trend for the risk of CRC was detected with the increasing number of putative risk genotypes (P (trend) = 0.00). However, no association was found between these four SNPs and the prognosis of CRC. In conclusion, APE1 (Asp148Glu), PARP1 (Ala762Val), and XRCC1 (Arg399Gln, Arg194Trp) were associated with the susceptibility to CRC, but were not associated with the prognosis of CRC.

A follow-up study has been carried out to assess the association between MTHFR polymorphisms (SNPs) and overall survival (OS) of colorectal cancer (CRC) patients. Data on 411 CRC patients after surgery were tested for the MTHFR 677C > T and 1298A > C polymorphisms. For MTHFR C677T, patients with CT genotype (HR = 1.17; 95 % CI 0.77-1.80) and those with TT genotype (HR = 1.09; 95 % CI 0.67-1.75) had no statistically significant greater risk of dying than those with wild-type genotype. For MTHFR A1298C, the HRs of AC and CC genotype were 1.09 (95 % CI 0.75-1.59) and 0.79 (95 % CI 0.48-1.29) comparing with AA genotype. In the subgroup, 183 patients received chemotherapy treatment, and the HRs of patients with CT and TT genotype were 0.93 (95 % CI 0.50-1.72) and 0.86 (95 % CI 0.44-1.68) for MTHFR C677T. For A1298C polymorphism, AC genotype (HR = 1.39; 95 % CI 0.81-2.39) and CC genotype (HR = 1.22; 95 % CI 0.75-2.00) did not show significant differences. In conclusions, no significant association was observed between the 677C > T and 1298A > C polymorphisms of MTHFR and the prognosis of colorectal cancer patients with curative resection, including all the subjects and the subgroup of chemotherapy.

Caspase (CASP) 3, 8, 9 are important caspases in the apoptosis pathway and play important roles in development and progression of cancer. A case-control study with 451 colorectal cancer (CRC) patients and 631 cancer-free controls were carried out, and CRC patients followed up, to investigate the associations between three main polymorphisms and colorectal cancer risk and prognosis, and their potential interactions with environmental factors on CRC risk among Chinese people. Genotypes were determined by polymerase chain reaction-restriction fragment length polymorphism and polymerase chain reaction-single strand conformation polymorphism sequencing. Odds ratio (OR), hazard ratio (HR) and their 95 % confidence intervals (CIs) were estimated with unconditional logistic-regression and Cox proportion hazard model. Individuals harboring the CASP8 -652 6N ins/del plus del/del genotype had a slightly lower risk for CRC compared those with ins/ins genotype (adjusted OR = 0.77, 95 % CI 0.59-0.99, P = 0.04). Significant associations between CASP3 -928 GG genotype and CASP9 -1263 GG genotype and reduced risk of rectal cancer were observed (adjusted OR = 0.56, 95 % CI 0.34-0.92, P = 0.02; adjusted OR = 0.59, 95 % CI 0.36-0.95, P = 0.03, respectively). There was a marginal significant association between CASP8 -652 6N ins/del polymorphism and CRC prognosis (ins/del versus ins/ins, adjusted HR = 0.69, 95 % CI 0.48-0.99, P = 0.04). These findings suggested these polymorphisms and their combinations with dietary factors may be associated with the development of CRC. CASP8 -652 6N ins/del polymorphism may be an independent survival predictor for CRC.

The prevalence of pathological germline mutations in colorectal cancer has been widely studied, as germline mutations in the DNA mismatch repair genes hMLH1 and hMSH2 confer a high risk of colorectal cancer. However, because the sample size and population of previous studies are very different from each other, the conclusions still remain controversial. In this paper, Databases such as PubMed were applied to search for related papers. The data were imported into Comprehensive Meta-Analysis V2, which was used to estimate the weighted prevalence of hMLH1 and hMSH2 pathological mutations and compare the differences of prevalence among different family histories, ethnicities and related factors. This study collected and utilized data from 102 papers. In the Amsterdam-criteria positive group, the prevalence of pathological germline mutations of the hMLH1 and hMSH2 genes was 28.55% (95%CI 26.04%-31.19%) and 19.41% (95%CI 15.88%-23.51%), respectively, and the prevalence of germline mutations in hMLH1/hMSH2 was 15.44%/10.02%, 20.43%/13.26% and 15.43%/11.70% in Asian, American multiethnic and European/Australian populations, respectively. Substitution mutations accounted for the largest proportion of germline mutations (hMLH1: 52.34%, hMSH2: 43.25%). The total prevalence of mutations of hMLH1 and hMSH2 in Amsterdam-criteria positive, Amsterdam-criteria negative and sporadic colorectal cancers was around 45%, 25% and 15%, respectively, and there were no obvious differences in the prevalence of germline mutations among different ethnicities.

Research on hMLH1 and hMSH2 mutations tend to focus on Lynch syndrome (LS) and LS-like colorectal cancer (CRC). No studies to date have assessed the role of hMLH1 and hMSH2 genes in mass sporadic CRC (without preselection by MSI or early age of onset). We aimed to identify novel hMLH1 and hMSH2 DNA variants, to determine the mutation frequencies and sites in both sporadic and LS CRC and their relationships with clinicopathological characteristics of CRC in Northeast of China. 452 sporadic and 21 LS CRC patients were screened for germline and somatic mutations in hMLH1 and hMSH2 genes with PCR-SSCP sequencing. We identified 11 hMLH1 and seven hMSH2 DNA variants in our study cohort. Six of them were novel: four in hMLH1 gene (IVS8-16 A>T, c.644 GAT>GTT, c.1529 CAG>CGG and c.1831 ATT>TTT) and two in hMSH2 gene (-39 C>T, insertion AACAACA at c.1127 and deletion AAG at c.1129). In sporadic CRC, germline and somatic mutation frequencies of hMLH1/hMSH2 gene were 15.59% and 17.54%, respectively (p = 0.52). Germline mutations present in hMLH1 and hMSH2 genes were 5.28% and 10.78%, respectively (p<0.01). Somatic mutations in hMLH1 and hMSH2 genes were 6.73% and 11.70%, respectively (p = 0.02). In LS CRC, both germline and somatic mutation frequencies of hMLH1/hMSH2 gene were 28.57%. The most prevalent germline mutation site in hMSH2 gene was c.1168 CTT>TTT (3.90%), a polymorphism. Somatic mutation frequency of hMLH1/hMSH2 gene was significantly different in proximal, distal colon and rectal cancer (p = 0.03). Our findings elucidate the mutation spectrum and frequency of hMLH1 and hMSH2 genes in sporadic and LS CRC, and their relationships with clinicopathological characteristics of CRC.

Natural-killer group 2 (NKG2), a natural killer (NK) cell receptor, plays a critical role in regulating NK cytotoxicity. In this study, we investigated the expression levels of natural killer group 2 member A (NKG2A) and natural killer group 2 member D (NKG2D) in NK cells as well as the regulatory function of NKG2D in patients with colorectal cancer (CRC). Sixty-two CRC patients and 32 healthy controls were enrolled in this study. The expression levels of NKG2A and NKG2D mRNA in peripheral blood mononuclear cells (PBMCs) were investigated using real-time PCR. Flow cytometry was performed to assay the levels of NKG2A and NKG2D proteins in NK cells. The levels of NKG2D mRNA in PBMCs in the patients were significantly lower than those in the controls [mean ± SD, 1.11 ± 0.60 (CRC patients) vs. 1.65 ± 0.71 (healthy controls); p < 0.01], whereas the 2 groups showed no apparent difference in the levels of NKG2A mRNA (p>0.05). In addition, the patients showed significantly lower NKG2D levels in NK cells than the controls did (71.23% ± 8.31% [CRC patients] vs. 79.39% ± 5.58% [healthy controls]; p < 0.01). However, we observed no distinct difference in the NKG2A expression levels in NK cells between the 2 groups (p> 0.05). Notably, blockage of NKG2D signaling with anti-NKG2D antibodies ex vivo resulted in decreased cytotoxicity and CD107a degranulation. Our data revealed that the decrease in NKG2D expression levels may have been associated with suppression of NK cell activity in CRC patients.

Objective: To detect the expression of fibroblast activation protein(FAP) in colorectal cancer tissue, and to investigate the association between expression of FAP with pathological parameters., Methods: Fifty-five cancer tissues and 50 normal colorectal samples were examined using immunohistochemistry with anti-FAP polyclonal antibody. The distribution of positive cells in different tissues, and associations of positive cell number with tumor staging, lymph node metastasis and tumor invasion were investigated to evaluate the effects of FAP on pathological progress in colorectal cancer., Results: No FAP expression was observed in 50 normal colorectal tissue samples. FAP positive cells were seen in carcinoma associated fibroblasts(CAFs), and in few colorectal cancer cells. The numbers of FAP positive cells in tissue samples of TNM III(-IIII((40.1±15.9) was significantly greater than that of TNMI(-II( (18.3±7.7)(P<0.01). Furthermore, the number of FAP positive cells in tissue samples with lymph node metastasis (44.4±13.3) was also significantly higher than those without lymph node metastasis (18.5±8.1)(P<0.01). Significant positive correlations were found between the number of FAP-positive cells with the tumor TNM staging and lymph node metastasis(r=0.544 and r=0.793, respectively)(P<0.01). The number of FAP-positive cells was 25.2±8.9 in T2, 32.41±19.30 in T3, and 29.2±16.5 in T4. The association between number of positive cells and depth of invasion was not statistically significant(P>0.05)., Conclusions: The FAP mainly expresses in CAFs locating in colorectal cancer tissues. The number of FAP positive cells is positively correlated with TNM staging of colorectal cancer and lymph node metastasis.

Background: The human double minute 2 (hdm2) oncogene is a negative regulator of the p53 gene. Expression and alternative splicing of the hdm2 gene may contribute to colorectal cancer development or progression. This study aimed to determine the presence and identification of aberrant mRNA transcripts of hdm2 in colorectal cancer tissues and cell lines, and determine the nature of their association with clinicopathological characteristics and survival of patients., Methods: A total of 69 colorectal cancer and corresponding normal tissue specimens and 10 colon cancer cell lines were recruited for polymerase chain reaction and DNA sequencing analyses of hdm2 mRNA. Genomic DNA from these tissues and cells was also extracted for p53 gene mutation analysis. The association of hdm2 fragmented transcripts and p53 gene mutation with clinicopathological data was then statistically analyzed., Results: In 62 cases (89.9%; 62 of 69) of colorectal cancer tissues the full-length hdm2 was amplified, whereas 7 cases had no hdm2 transcripts. Thirty-two of 62 cases (51.6%) and 6 of 10 cell lines (60%) showed at least 1 hdm2 spliced variant. A total of 4 hdm2 splicing variants were found in colorectal cancer tissues and cells, that is, lack of nucleotides between 157 and 292 bp in hdm2/1338, 81 to 901 bp in hdm2/707, 157 to 292, 407 to 505, and 668 to 901 bp in hdm2/1007, and 610 to 883 in hdm2/1200. Of these, hdm2/1338 is a novel hdm2 variant in colorectal cancer. Mutation in p53 was detected in 21 cases (33.8%; 21 of 62). Although there was no association found between expression of hdm2 splicing variants and p53 gene mutations, expression of hdm2 splicing variants was associated with advanced tumor stage (P = .022) and distant metastasis (P = .004) in wild-type p53 cases, and with poor survival of patients (P = .039)., Conclusions: The data from the current study provide the first evidence that hdm2 mRNA is frequently mutated by alternative splicing in colorectal cancer, and may play a role in colorectal tumorigenesis or cancer progression., (Copyright © 2011 American Cancer Society.)

The phosphatidylinositol 3-kinase/AKT (PI3K/AKT) pathway plays a critical role in human cancer. We determined the expression patterns of class I PI3K catalytic subunits and evaluated their importance in the development or progression of colorectal cancer (CRC). For this purpose, expression of class I PI3K isoforms was evaluated in 82 primary CRC and paired non-cancerous mucosa samples by qRT-PCR. P-AKT-Ser473 and P-AKT-Thr308 expression were measured by western blot. We found that, compared with paired non-cancerous mucosa samples, mRNA expression of p110α and p110β in CRCs was significantly increased to 2.02-fold (95% confidence interval [CI] 1.25-3.28 fold) and 1.76-fold (95% CI 1.19-2.60 fold), respectively; while slight differences were found regarding the expression of p110δ (0.57-fold; 95% CI 0.31-1.07 fold) and p110γ (0.97-fold; 95% CI 0.50-1.88 fold). Increased p110α and p110β expression correlated with primary tumor size, regional lymph node metastases, and AJCC stage. Increased p110β expression also correlated with distant metastasis. P-AKT-Thr308 and P-AKT-Ser473 expression showed significant direct correlations with p110α and p110β mRNA expression. Besides, CRC patients with p110β mRNA overexpression had a worse disease-free survival after radical surgery compared with those with normal or decreased levels (P = 0.043). It was, therefore, concluded that the altered p110α and p110β expression might contribute to the CRC development or progression.

Objective: To evaluate the value of positron emission tomography (PET) in diagnosing liver metastases from colorectal cancer., Methods: Eighteen patients suspected with liver metastases after resection of colorectal cancer and three patients suspected with other diseases were diagnosed by PET and CT before operation. The result of both diagnostic approaches was compared with the result of exploratory operation., Results: Seventeen of 18 patients were confirmed as liver metastases after resection of colorectal cancer, in whom 14 patients had other synchronous metastases outside liver metastasis including lung metastasis (n= 2), abdominal wall metastasis (n= 2 ), bone metastasis (n= 1), peritoneal cavity lymph nodes metastasis (n= 6), mediastinal lymph nodes (n= 2), virchow lymph node metastasis (n= 1). One patient with negative PET diagnosis was still alive with cancer- free after 1 year followed- up. Three patients suspected with other diseases were also diagnosed as liver metastases from colorectal cancer by PET., Conclusion: PET has higher sensitivity in diagnosing liver metastases or other synchronous metastases after resection of colorectal cancer, which suggests that PET can guide the determination of second operative surgery for liver metastases after resection of colorectal cancer.