Poor Survival In Colorectal Cancer Patients Research Articles

MicroRNA-485-5p reduces O-GlcNAcylation of Bmi-1 and inhibits colorectal cancer proliferation

Emerging evidences showed that miRNAs are involved in the oncogenesis of many cancers. Here, miRNA microarray analysis was performed to screen the significant miRNAs involved in the progression of colorectal cancer (CRC), miR-485-5p was chosen for further study. We found that the expression of miR-485-5p was significantly lower in CRC specimens and cell lines. In addition, low expression level of miR-485-5p is correlated with tumor progression and poor survival in CRC patients. Based on in vitro and in vivo assays, we found that miR-485-5p significantly inhibits CRC proliferation. Moreover, our results showed that miR-485-5p inhibits cell proliferation by reducing Bmi-1 protein expression, which has been reported to control the proliferation of many cancers. Mechanistically, OGT is a direct target of miR-485-5p, and miR-485-5p could inhibit the O-GlcNAcylation level of Bmi-1 by OGT. Overall, these results suggested that as a tumor suppressor, miR-485-5p may regulate CRC cells proliferation, which could regulate the O-GlcNAcylation and the stability of Bmi-1 through targeting OGT. This may give insight into a novel mechanism and therapy of CRC growth.

Dose-Response Relationship between Serum Retinol Levels and Survival in Patients with Colorectal Cancer: Results from the DACHS Study.

Current knowledge on the role of retinol in the prognosis of patients with colorectal cancer (CRC) is very limited. We investigated the association of serum retinol levels with survival outcomes in a large cohort of 2908 CRC patients from Germany. Retinol concentrations were determined in serum collected shortly after diagnosis by mass spectrometry. Associations between serum retinol levels and survival outcomes were assessed using multivariable Cox regression and dose-response analyses. The joint association of serum retinol and serum 25-hydroxyvitamin D3 (25(OH)D3) with survival outcomes was also examined. During a median follow-up of 4.8 years, 787 deaths occurred, 573 of which were due to CRC. Dose-response curves showed an inverse relationship between serum retinol levels and survival endpoints in the range of <2.4 µmol/L, but no associations at higher levels. Low (<1.2 µmol/L) versus high (≥2.4 µmol/L) serum retinol levels were associated with poorer overall survival (Hazard ratio (HR) = 1.46, 95% confidence interval (CI) = 1.19–1.78, P-trend = 0.0003) and CRC-specific survival (HR = 1.69, 95% CI = 1.33–2.15, P-trend < 0.0001). Joint presence of low serum retinol (<1.2 µmol/L) and low 25(OH)D3 (<30 nmol/L) was associated with a particularly strong decrease in overall and CRC-specific survival. Low serum retinol levels were identified as a predictor of poor survival in CRC patients, in particular when co-occurring with low serum concentrations of 25(OH)D3. The clinical implications of these findings require further investigation.

DEAD-box helicase 27 promotes colorectal cancer growth and metastasis and predicts poor survival in CRC patients

Copy number alterations (CNAs) are crucial for colorectal cancer (CRC) development. In this study, DEAD box polypeptide 27 (DDX27) was identified to be highly amplified in both TCGA CRC (474/615) and primary CRC (47/103), which was positively correlated with its mRNA overexpression. High DDX27 mRNA (N = 199) and protein expression (N = 260) predicted poor survival in CRC patients. Ectopic expression of DDX27 increased CRC cells proliferation, migration and invasion, but suppressed apoptosis. Conversely, silencing of DDX27 exerted opposite effects in vitro and significantly inhibited murine xenograft tumor growth and lung metastasis in vivo. Up-regulation of DDX27 enhanced and prolonged TNF-α-mediated NF-κB signaling. Nucleophosmin (NPM1) was identified as a binding partner of DDX27. DDX27 increased nuclear NPM1 and NF-κB-p65 interaction to enhance DNA binding activity of NF-κB. Silencing NPM1 abrogated DDX27-activating NF-κB signaling and its tumor-promoting function. Together, DDX27 is overexpressed and plays a pivotal oncogenic role in CRC.

Capn4 promotes colorectal cancer cell proliferation by increasing MAPK7 through activation of the Wnt/β-Catenin pathway

Increasing evidence has suggested that Capn4 is upregulated and functions as a potential tumor promoter in several human cancer types. However, the potential biological roles and regulatory mechanisms of Capn4 in colorectal cancer (CRC) remains unclear. Here, we found that Capn4 expression was elevated in CRC tissues than adjacent noncancerous tissues. Additionally, we also found that overexpression of Capn4 is significantly correlated with tumor progression and poor survival in CRC patients. Furthermore, our experimental data revealed that increased expression of Capn4 was observed in CRC cell lines and ectopic expression of Capn4 significantly enhanced in vitro cell proliferation, whereas knockdown of Capn4 suppressed CRC cells growth in vitro and in vivo. Moreover, our results indicate that Capn4 promotes cell proliferation by increasing MAPK7 expression, which has been reported to control the proliferation of many cancers. Mechanistically, Capn4 upregulates MAPK7 expression through activation of the Wnt/β-Catenin pathway in CRC cells. Therefore, we identified a tumorigenic role of Capn4 in CRC and suggested a potential therapeutic target for CRC patients.

NFYB-induced high expression of E2F1 contributes to oxaliplatin resistance in colorectal cancer via the enhancement of CHK1 signaling

As a third-generation platinum drug, oxaliplatin has been widely applied in colorectal cancer (CRC); however, acquired resistance to oxaliplatin has become a major obstacle. In the present study, we found that the nuclear transcription factor Y subunit beta (NFYB) and E2F transcription factor 1 (E2F1) expression levels were significantly higher in oxaliplatin-resistant DLD1 and RKO CRC (OR-CRC) cells than in non-resistant cells. Additionally, highly expressed NFYB transactivated the E2F1 gene, which is important to maintain oxaliplatin resistance in OR-CRC cells. And Sirt1-dependent deacetylation suppresses the proapoptotic activity of E2F1 in OR-CRC cells. Through profiling the transcriptome of OR-CRC cells following E2F1 knockdown, CHK1 was identified as a target of E2F1. Deprivation of CHK1 sensitized OR-CRC cells to oxaliplatin. In vitro and in vivo phenotype experiments confirmed that an intact NFYB-E2F1-CHK1 axis was required to suppress oxaliplatin-induced apoptosis and maintain the tumorigenicity in OR-CRC cells. Knockdown of E2F1 in OR-CRC cells also decreased the expression of Pol κ, which was essential for CHK1 activation. Consistently, a high level of NFYB, E2F1, or CHK1 predicted poor survival in CRC patients, especially with oxaliplatin treatment. Collectively, the NFYB-E2F1 pathway displays a crucial role in the chemoresistance of OR-CRC by inducing the expression and activation of CHK1, providing a possible therapeutic target for oxaliplatin resistance in CRC.

UBR5 Contributes to Colorectal Cancer Progression by Destabilizing the Tumor Suppressor ECRG4.

The E3 ligase UBR5 is aberrantly expressed in diverse types of cancer. However, its expression pattern and biological function in colorectal cancer (CRC) remain unclear. We used RT-PCR, Western blot, and immunohistochemistry to measure UBR5 expression in CRC tissues and corresponding non-tumor tissues. The expression pattern of UBR5 in CRC tissues was determined by scoring system of immunohistochemical analysis and mRNA level by RT-PCR. The statistical analyses were applied to evaluate the associations of UBR5 expression with survival rate of patients. The UBR5 gene was overexpressed or silenced with lentiviral vectors in CRC cells. And, cell proliferation and apoptosis were measured using CCK8 assay and flow cytometry. We found that UBR5 is abundantly overexpressed in CRC tissues than adjacent non-cancerous tissues. We also found that high UBR5 level is positively correlated with progression and poor survival in CRC patients. In addition, further multivariate analysis indicated that UBR5 and TNM stage were independent prognostic factors for overall survival in patients with CRC. Furthermore, we demonstrated that the expression of UBR5 was significantly elevated in CRC cell lines. Overexpression of UBR5 enhanced in vitro cell proliferation and promoted in vivo tumor growth, whereas silencing UBR5 suppressed growth of CRC cells. Moreover, our findings show that UBR5 promotes CRC cell proliferation by inducing cell cycle progression and suppressing cell apoptosis. Finally, we found that UBR5 directly binds to the tumor suppressor esophageal cancer-related gene 4 (ECRG4) and increased its ubiquitination to reduce the protein stability of ECRG4. We identified a tumorigenic role of UBR5 in CRC and provided a novel therapeutic target for CRC patients.

Pre-45s rRNA promotes colon cancer and is associated with poor survival of CRC patients

One characteristic of cancer cells is the abnormally high rate of cell metabolism to sustain their enhanced proliferation. However, the behind mechanism of this phenomenon is still elusive. Here we find that enhanced precursor 45s ribosomal RNA (pre-45s rRNA) is one of the core mechanisms in promoting the pathogenesis of colorectal cancer (CRC). Pre-45s rRNA expression is significantly higher in primary CRC tumor tissues samples and cancer cell lines compared with the non-tumorous colon tissues, and is associated with tumor sizes. Knockdown of pre-45s rRNA inhibits G1/S cell-cycle transition by stabilizing p53 through inducing murine double minute 2 (MDM2) and ribosomal protein L11 (RpL11) interaction. In addition, we revealed that high rate of cancer cell metabolism triggers the passive release of calcium ion from endoplasmic reticulum to the cytoplasm. The elevated calcium ion in the cytoplasm activates the signaling cascade of calcium/calmodulin-dependent protein kinase II, ribosomal S6 kinase (S6K) and ribosomal S6K (CaMKII-S6K-UBF). The activated UBF promotes the transcription of rDNA, which therefore increases pre-45s rRNA. Disruption of CaMKII-S6K-UBF axis by either RNAi or pharmaceutical approaches leads to reduction of pre-45s rRNA expression, which subsequently suppresses cell proliferation in colon cancer cells by causing cell-cycle arrest. Knockdown of APC activates CaMKII-S6K-UBF cascade and thus enhances pre-45s rRNA expression. Moreover, the high expression level of pre-45s rRNA is associated with poor survival of CRC patients in two independent cohorts. Our study identifies a novel mechanism in CRC pathogenesis mediated by pre-45s rRNA and a prognostic factor of pre-45s rRNA in CRC patients.

Synergistic interaction between galectin-3 and carcinoembryonic antigen promotes colorectal cancer metastasis.

In this study, we investigated the role of galectin-3 and carcinoembryonic antigen (CEA) in metastasis and survival of colorectal cancer (CRC) patients. CEA interacted with galectin-3 at the cell surface and cytoplasm of Caco2 and DLD1 CRC cells. Knocking down galectin-3 did not affect CEA expression in CRC cells. However, there was a dose-dependent increase in CRC cell migration upon addition of small amounts of exogenous CEA (≤1ng/ml). Galectin-3 knockdown blocked induction of CRC cell migration by CEA, suggesting interaction between galectin-3 and CEA was necessary for CRC cell migration. Exogenous CEA and galectin-3 synergistically promoted migration of galectin-3 knockdown DLD1 cells. Immunohistochemical analysis showed that CEA co-localized with galectin-3 in CRC patient tissues. In additon, advanced stage CRC patients had higher serum galectin-3 and CEA levels than early stage CRC patients. High serum CEA and galectin-3 levels correlated with advanced N stage and poor survival in CRC patients. These findings suggest interaction between galectin-3 and CEA promotes CRC migration and metastasis, and correlates with poor survival of CRC patients. Thus combinatorial therapy targeting galectin-3 and CEA may improve outcomes for advanced stage CRC patients.

RSPO2 suppresses colorectal cancer metastasis by counteracting the Wnt5a/Fzd7-driven noncanonical Wnt pathway

R-spondins play critical roles in development, stem cell survival, and tumorigenicity by modulating Wnt/β-catenin signaling; however, the role of R-spondins in noncanonical Wnt signaling regulation remains largely unknown. We demonstrate here that R-spondin 2 (RSPO2) has an inhibitory effect on colorectal cancer (CRC) cell migration, invasion, and metastasis. Reduced RSPO2 expression was associated with tumor metastasis and poor survival in CRC patients. The metastasis-suppressive activity of RSPO2 was independent of the Wnt/β-catenin signaling pathway but dependent on the Fzd7-mediated noncanonical Wnt signaling pathway. The physical interaction of RSPO2 and Fzd7 increased the degradation of cell surface Fzd7 via ZNRF3-mediated ubiquitination, which led to the suppression of the downstream PKC/ERK signaling cascade. In late-stage metastatic cancer, Wnt5a promoted CRC cell migration by preventing degradation of Fzd7, and RSPO2 antagonized Wnt5a-driven noncanonical Wnt signaling activation and tumor cell migration by blocking the binding of Wnt5a to the Fzd7 receptor. Our study reveals a novel RSPO2/Wnt5a-competing noncanonical Wnt signaling mechanism that regulates cellular migration and invasion, and our data suggest that secreted RSPO2 protein could serve as a potential therapy for Wnt5a/Fzd7-driven aggressive CRC tumors.

Stromal-derived IGF2 promotes colon cancer progression via paracrine and autocrine mechanisms.

The insulin-like growth factor (IGF)2/IGF1 receptor (IGF1R) signaling axis has an important role in intestinal carcinogenesis and overexpression of IGF2 is an accepted risk factor for colorectal cancer (CRC) development. Genetic amplifications and loss of imprinting contribute to the upregulation of IGF2, but insufficiently explain the extent of IGF2 expression in a subset of patients. Here, we show that IGF2 was specifically induced in the tumor stroma of CRC and identified cancer-associated fibroblasts (CAFs) as the major source. Further, we provide functional evidence that stromal IGF2, via the paracrine IGF1R/insulin receptor axis, activated pro-survival AKT signaling in CRC cell lines. In addition to its effects on malignant cells, autocrine IGF2/IGF1R signaling in CAFs induced myofibroblast differentiation in terms of alpha-smooth muscle actin expression and contractility in floating collagen gels. This was further augmented in concert with transforming growth factor-β (TGFβ) signaling suggesting a cooperative mechanism. However, we demonstrated that IGF2 neither induced TGFβ/smooth muscle actin/mothers against decapentaplegic (SMAD) signaling nor synergized with TGFβ to hyperactivate this pathway in two dimensional and three dimensional cultures. IGF2-mediated physical matrix remodeling by CAFs, but not changes in extracellular matrix-modifying proteases or other secreted factors acting in a paracrine manner on/in cancer cells, facilitated subsequent tumor cell invasion in organotypic co-cultures. Consistently, colon cancer cells co-inoculated with CAFs expressing endogenous IGF2 in mouse xenograft models exhibited elevated invasiveness and dissemination capacity, as well as increased local tumor regrowth after primary tumor resection compared with conditions with IGF2-deficient CAFs. In line, expression of IGF2 correlated with elevated relapse rates and poor survival in CRC patients. In agreement with our results, high-level coexpression of IGF2 and TGFβ was predicting adverse outcome with higher accuracy than increased expression of the individual genes alone. Taken together, we demonstrate that stroma-induced IGF2 promotes colon cancer progression in a paracrine and autocrine manner and propose IGF2 as potential target for tumor stroma cotargeting strategies.

RGC32 induces epithelial-mesenchymal transition by activating the Smad/Sip1 signaling pathway in CRC

Response gene to complement 32 (RGC32) is a transcription factor that regulates the expression of multiple genes involved in cell growth, viability and tissue-specific differentiation. However, the role of RGC32 in tumorigenesis and tumor progression in colorectal cancer (CRC) has not been fully elucidated. Here, we showed that the expression of RGC32 was significantly up-regulated in human CRC tissues versus adjacent normal tissues. RGC32 expression was significantly correlated with invasive and aggressive characteristics of tumor cells, as well as poor survival of CRC patients. We also demonstrated that RGC32 overexpression promoted proliferation, migration and tumorigenic growth of human CRC cells in vitro and in vivo. Functionally, RGC32 facilitated epithelial-mesenchymal transition (EMT) in CRC via the Smad/Sip1 signaling pathway, as shown by decreasing E-cadherin expression and increasing vimentin expression. In conclusion, our findings suggested that overexpression of RGC32 facilitates EMT of CRC cells by activating Smad/Sip1 signaling.

FAP positive fibroblasts induce immune checkpoint blockade resistance in colorectal cancer via promoting immunosuppression

Immune checkpoint blockades that significantly prolonged survival of melanoma patients have been less effective on colorectal cancer (CRC) patients. Growing evidence suggested that fibroblast activation protein-alpha (FAP) on cancer associate fibroblasts (CAFs) has critical roles in regulating antitumor immune response by inducing tumor-promoting inflammation. In this study, we explored the roles of FAP in regulating the tumor immunity and immune checkpoint blockades resistance in CRC experimental systems. We found that CAFs with high FAP expression could induce immune checkpoint blockade resistance in CRC mouse model. Mechanistically, CAFs with high FAP expression promoted immunosuppression in the CRC tumor immune microenvironment by up-regulating CCL2 secretion, recruiting myeloid cells, and decreasing T-cell activity. In human CRC samples, FAP expression was proportional to myeloid cells number, but inversely related to T-cell number. High FAP expression also predicted poor survival of CRC patients. Taken together, our study suggested that high FAP expression in CAFs is one reason leading to immune checkpoint blockades resistance in CRC patients and FAP is an optional target for reversing immune checkpoint blockades resistance.

Annexin A13 promotes tumor cell invasion in vitro and is associated with metastasis in human colorectal cancer.

PurposeAberrantly upregulated expression of selected members of annexin, a group of calcium- and membrane-binding proteins, have been found to be associated with metastasis, poor prognosis, and other clinical characteristics in colorectal cancer (CRC), the third most diagnosed cancer. However, ANXA13 (encoding protein annexin A13), the original founder gene of the annexin A family, has not been studied carefully as a potential prognostic biomarker in CRC.MethodsThe protein level of annexin A13 was determined by western blot in a panel of CRC cell lines. Tumor cell invasion was determined by a Matrigel in vitro invasion assay in selected CRC cells with either upregulated (via plasmid transfection) or downregulated (via siRNA treatment) expression of ANXA13. The clinicopathological features and prognostic values associated with ANXA13 expression were also evaluated in a group of 125 CRC patients.ResultsANXA13 was expressed at a high level in HCT116 and HT29 cells but undetected or at a lower level in SW620, SW48, and Rko cells. CRC cell invasion was promoted by ANXA13 overexpression in SW620 or Rko cells and was reduced by ANXA13 downregulation in HCT116 or HT29 cells. In CRC patients, ANXA13 expression levels correlated with lymph node metastasis and were associated with poor overall survival.ConclusionsANXA13 is associated with CRC cell invasion in vitro, and with lymph node metastasis and poor survival in CRC patients. Our results indicate that ANXA13 can be exploited as a biomarker for its diagnostic and prognostic values.

Prognostic factors and survival of colorectal cancer in Kurdistan province, Iran: A population-based study (2009-2014).

Colorectal cancer (CRC) survival varies at individual and geographically level. This population-based study aimed to evaluating various factors affecting the survival rate of CRC patients in Kurdistan province.In a retrospective cohort study, patients diagnosed as CRC were collected through a population-based study from March 1, 2009 to 2014. The data were collected from Kurdistan's Cancer Registry database. Additional information and missing data were collected reference to patients' homes, medical records, and pathology reports. The CRC survival was calculated from the date of diagnosis to the date of cancer-specific death or the end of follow-up (cutoff date: October 2015). Kaplan-Meier method and log-rank test were used for the univariate analysis of survival in various subgroups. The proportional-hazard model Cox was also used in order to consider the effects of different factors on survival including age at diagnosis, place of residence, marital status, occupation, level of education, smoking, economic status, comorbidity, tumor stage, and tumor grade.A total number of 335 patients affected by CRC were assessed and the results showed that 1- and 5-year survival rate were 87% and 33%, respectively. According to the results of Cox's multivariate analysis, the following factors were significantly related to CRC survival: age at diagnosis (≥65 years old) (HR 2.08, 95% CI: 1.17-3.71), single patients (HR 1.62, 95% CI: 1.10-2.40), job (worker) (HR 2.09, 95% CI: 1.22-3.58), educational level: diploma or below (HR 0.61, 95% CI: 0.39-0.92), wealthy economic status (HR 0.51, 95% CI: 0.31-0.82), tumor grade in poorly differentiated (HR 2.25, 95% CI: 1.37-3.69), and undifferentiated/anaplastic grade (HR 2.90, 95% CI: 1.67-4.98).We found that factors such as low education, inappropriate socioeconomic status, and high tumor grade at the time of disease diagnosis were effective in the poor survival of CRC patients in Kurdistan province; this, which need more attention.

MiRNA-203 suppresses cell proliferation, migration and invasion in colorectal cancer via targeting of EIF5A2.

While it is known that miR-203 is frequently downregulated in many types of human cancer, little is known regarding its expression and functional role in colorectal cancer (CRC). In this study, we aimed to investigate the expression and the potential mechanisms of miR-203 in colorectal cancer. MiR-203 was significantly downregulated in CRC tissues compared with matched normal adjacent tissues. Our clinical data show that decreased miR-203 was associated with an advanced clinical tumor-node-metastasis stage, lymph node metastasis, and poor survival in CRC patients. Furthermore, externally induced expression of miR-203 significantly inhibited CRC cell proliferation and invasion in vitro and in vivo. Mechanistically, we identified EIF5A2 as a direct and functional target of miR-203. The levels of miR-203 were inversely correlated with levels of the EIF5A2 in the CRC tissues. Restoration of EIF5A2 in the miR-203-overexpressing CRC cells reversed the suppressive effects of miR-203. Our results demonstrate that miR-203 serves as a tumor suppressor gene and may be useful as a new potential therapeutic target in CRC.

A genomic screen for long noncoding RNA genes epigenetically silenced by aberrant DNA methylation in colorectal cancer.

Long noncoding RNAs (lncRNAs) have emerged as key components in multiple cellular processes, although their physiological and pathological functions are not fully understood. To identify cancer-related lncRNAs, we screened for those that are epigenetically silenced in colorectal cancer (CRC). Through a genome-wide analysis of histone modifications in CRC cells, we found that the transcription start sites (TSSs) of 1,027 lncRNA genes acquired trimethylation of histone H3 lysine 4 (H3K4me3) after DNA demethylation. Integrative analysis of chromatin signatures and the DNA methylome revealed that the promoter CpG islands (CGIs) of 66 lncRNA genes contained cancer-specific methylation. By validating the expression and methylation of lncRNA genes in CRC cells, we ultimately identified 20 lncRNAs, including ZNF582-AS1, as targets of epigenetic silencing in CRC. ZNF582-AS1 is frequently methylated in CRC cell lines (87.5%), primary CRCs (77.2%), colorectal adenomas (44.7%) and advanced adenomas (87.8%), suggesting that this methylation is an early event during colorectal tumorigenesis. Methylation of ZNF582-AS1 is associated with poor survival of CRC patients, and ectopic expression of ZNF582-AS1 suppressed colony formation by CRC cells. Our findings offer insight into the association between epigenetic alterations and lncRNA dysregulation in cancer and suggest that ZNF582-AS1 may be a novel tumor-suppressive lncRNA.

Plasma miR-183 predicts recurrence and prognosis in patients with colorectal cancer

Colorectal cancer (CRC) is one of the most common malignancies worldwide. The prognosis for this cancer is poor, and the development of novel biomarkers, particularly non-invasive surrogate biomarkers, is urgently needed. Recent studies have demonstrated that microRNAs (miRNAs) are stably detectable in the blood and can serve as useful biomarkers for various types of cancer. In this study, the miR-183 expression levels were found to be significantly overexpressed in plasma samples from CRC patients compared with controls, and the postoperative plasma miR-183 levels were significantly reduced compared with the preoperative levels. The value of the area under the receiver operating characteristic (ROC) curve obtained for miR-183 was 0.829, which was higher than those for carcinoembryonic antigen (CEA) and carbohydrate antigen 19-9 (CA19-9). High plasma miR-183 expression was significantly associated with lymph node metastasis, distant metastasis, higher pTNM stage (III-IV), and tumor recurrence. CRC patients with elevated miR-183 expression in plasma displayed shorter disease-free survival (DFS) and lower overall survival (OS). More importantly, plasma miR-183 was independently correlated with tumor recurrence and a lower OS. Collectively, our results suggested that the elevated miR-183 in the plasma could be a promising biomarker for predicting the risk of tumor recurrence and poor survival in CRC patients.

Preoperative serum microRNA-203 as a novel prognostic and metastasis-predictive biomarker in patients with colorectal cancer.

564 Background: Distant metastasis is the major causes of death in colorectal cancer (CRC) patients. Epithelial-mesenchymal transition (EMT) is a key process that converts polarized immotile epithelial cells into motile, invasive mesenchymal cells, enabling cancer cells to gain stem cell characteristics and an aggressive malignant phenotype such as metastasis. Mir-203 has been shown to directly suppress EMT activators such as ZEB2 and SNAI1/2. However, in spite of the key functional role of miR-203 in cancer metastasis, no previous studies have investigated the clinical significance of miR-203 in patients with CRC. Methods: To examine whether CRCs secret miR-203 in vitro and vivo,we first determined extracellular miR-203 levels in CRC cell culture media. Then, we quantified miR-203 levels in serum from mice with or without metastasis. Next, we investigated miR-203 expression in 58 pairs of primary CRC (pCRC) and corresponding matching liver metastasis (LM), as well as 186 serum and 154 matched tissue specimens from CRC patients. Results: HT-29 cells released miR-203 into culture media, which was dependent on cell number and duration of culture. In addition, high serum miR-203 levels were observed in mice with liver metastasis compared to control animals (p=0.0181). Mir-203 expression was significantly upregulated in LM compared to matching pCRC tissues (p=0.0002). Serum miR-203 was significantly upregulated in a tumor stage-dependent manner (p=0.0070), and high miR-203 expression was associated with poor survival in CRC patients (p&lt;0.0001). In contrast to serum, no significant association between miR-203 expression in CRC tissues and clinicopathological findings was recognized. High serum miR-203 expression was an independent risk factor for poor prognosis (HR=2.1) as well as metastasis to lymph nodes (OR=2.5), liver (OR=6.2), peritoneum (OR=7.2), and distant organs (OR=4.4), respectively. Conclusions: High levels of serum miR-203, which may be derived from several metastatic sites, are associated with poor survival and metastasis, suggesting it is a promising non-invasive prognostic and metastasis-predictive biomarker in patients with CRC.

ArhGAP30 promotes p53 acetylation and function in colorectal cancer.

Covalent modification adding acetyl groups to the C terminus of the p53 protein has been suggested to be required for its functional activation as a tumour suppressor. However, it remains largely unknown how p53 acetylation is deregulated in colorectal cancer (CRC), which is the third most commonly diagnosed cancer worldwide. Here we show that ArhGAP30, a Rho GTPase-activating protein, is a pivotal regulator for p53 acetylation and functional activation in CRC. ArhGAP30 binds to p53 C-terminal domain and P300, facilitating P300-mediated acetylation of p53 at lysine 382. ArhGAP30 expression is required for p53 activation upon DNA damage stress, and the level of ArhGAP30 correlates with p53 acetylation and functional activation in CRC tissues. Moreover, low level of ArhGAP30 expression associates with poor survival of CRC patients. In summary, ArhGAP30 is required for p53 acetylation and functional activation in CRC, and the expression of ArhGAP30 is a potential prognostic marker for CRC.

CCR6 Is a Prognostic Marker for Overall Survival in Patients with Colorectal Cancer, and Its Overexpression Enhances Metastasis In Vivo

The chemokine receptor CCR6 has been recently shown to be associated with colorectal cancer (CRC) progression. However, the direct evidence for whether CCR6 in tumors is a prognostic marker for the survival of patients with CRC and whether it plays a critical role in CRC metastasis in vivo is lacking. Here we show that the levels of CCR6 were upregulated in CRC cell lines and primary CRC clinical samples. CCR6 upregulation was closely correlated with disease stages and the survival time of CRC patients. Knockdown of CCR6 inhibited the migration of CRC cells in vitro. Overexpression of CCR6 in CRC cells increased their proliferation, migration, and colony formation in vitro and promoted their metastatic potential in vivo. CCR6 activated Akt signaling, upregulated metastasis genes and downregulated metastasis suppressor genes. Selective targeting of CCR6 in tumors dramatically inhibited the growth of CRC in mice. Thus, the tumor expression of CCR6 plays a critical role in CRC metastasis, upregulated CCR6 predicts poor survival in CRC patients, and targeting CCR6 expression in tumors may be a potential therapeutic strategy for CRC.