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This study investigated the role of miR-214 in modulating proliferation and invasion of human colon cancer SW620 cells. Fifty-five patients with colon cancer who were treated in China-Japan Union Hospital of Jilin University from March 2014 to March 2015 were enrolled into this study. Their cancer and corresponding paracancerous tissues were collected and the expression levels of miR-214 were determined by RT-qPCR. A miR-214 expression vector was constructed. SW620 cells were transfected with the miR-214 expression vector and a blank vector. Cells transfected with the miR-214 expression vector were assigned to the miR-214 positive group and cells transfected with the blank vector were assigned to the miR-214 negative group. Cell proliferation, invasion and apoptosis were assessed by MTT assay, Transwell migration assay and TUNEL apoptosis assay, respectively. The RT-qPCR results showed that the expression level of miR-214 in colon cancer tissue, as well as in miR-214 negative cells, was significantly lower than that in paracancerous tissue (P<0.05 for both). In cell comparison, the expression level of miR-214 in the miR-214 positive group was significantly higher than that in the miR-214 negative group (0.483±0.001 vs. 0.172±0.001; P<0.05). The proliferation level of SW620 cells in the miR-214 positive group was lower than that in the miR-214 negative group (P<0.05). The Transwell migration assay indicated that there were less cells penetrating the membrane in the miR-214 positive group than in the miR-214 negative group (P<0.05). In addition, The apoptosis rate of cells in the miR-214 negative group was significantly lower than that in the miR-214 positive group (P<0.05). Finally, the low expression of miR-214 was found in colon cancer, indicating that miR-214 is a cancer suppressor playing an opposing role in colon cancer onset and progression. Therefore, miR-214 can promote apoptosis of colon cancer cells SW620 by inhibiting their proliferation and invasion. [ABSTRACT FROM AUTHOR]

Colorectal cancer (CRC) is a common digestive system malignancy with high morbidity and mortality. Accumulating studies have shown that miRNAs play a critical role in the progression of CRC. Here, we explored the effect of miR-329 and its target gene on the sensitivity of 5-fluorouracil (5-FU) in the chemotherapy of CRC. RT-qPCR was utilized to determine the expression of miR-329 in cancer tissues, adjacent tissues and cells. CCK-8 and Transwell assays were introduced to detect the role of miR-329 overexpression in cell viability and invasion. Luciferase reporter assay was performed to verify that E2F1 was a direct target of miR-329. Protein expression of E2F1 was accessed by western blot analysis. The expression level of miR-329 was decreased in CRC tissues and tumor tissues at stage III+IV with lymph node metastasis, and the patients' total survival time was positively associated with the expression of miR-329. Overexpression of miR-329 significantly attenuated the viability and invasiveness of tumor cells. The viability of drug-resistant cells was markedly higher than that of non-resistant cells under the same dose of 5-FU treatment. The expression of miR-329 in tumor cells was negatively associated with drug sensitivity. Luciferase reporter assay showed that E2F1 was the direct target of miR-329. Besides, the expression of E2F1 protein in drug-resistant cells was remarkably higher than that in the non-resistant cells, while the overexpression of miR-329 significantly decreased the expression of E2F1 protein. E2F1 overexpression increased cell viability, but overexpression of both E2F1 and miR-329 in turn decreased cell viability. miR-329 expression is reduced in CRC, and overexpression of miR-329 promotes the sensitivity of 5-FU in the chemotherapy of CRC by degrading the target gene E2F1. [ABSTRACT FROM AUTHOR]

Colorectal cancer is a human malignancy ranked the third highest of the global incidence of malignant tumors. Rho GTPase‑activating proteins (RHOGAPs) were identified functional in several processes of tumors. In the present study, through reverse transcription-quantitative PCR (RT-qPCR) and western blot analysis, expression of Rho GTPase‑activating protein 24 (ARHGAP24) and p53 was measured in colorectal cancer tissues, which was lower than that in adjacent normal tissues, revealing that ARHGAP24 may be implicated in the progress of colorectal cancer and in vitro, overexpression of ARHGAP24 in LoVo and HCT116 cells inhibited the cell ability and enhanced cell apoptosis, and accompanied with high protein expression of p53, p21 and Bax. Further, addition of p53 inhibitor PFT-α had an antagonistic effect on cell proliferation and apoptosis of LoVo and HCT116 cells induced by ARHGAP24 overexpression. In addition, the expression of p21 and Bax was positively correlated with p53 expression. All of the above data demonstrated that ARHGAP24 was likely to be a tumor suppressor in colorectal cancer and may function closely related to p53, p21 and Bax. We inferred that ARHGAP24 may be a novel target for in-depth study of colorectal cancer. [ABSTRACT FROM AUTHOR]

Long non‑coding RNA H19 has been identified to be dysregulated in a number of tumor types, and is closely associated with cancer progression. RAS/mitogen‑activated protein kinase (MAPK) is an important intracellular signaling transduction pathway. Activation of the RAS‑MAPK signaling pathway is one of the most frequent carcinogenic events in human cancer. However, the mechanism of H19 in promoting the migration and invasion of colorectal cancer (CRC) cells, and the association between H19 and RAS‑MAPK signaling pathway is not well understood. The aim of the present study was to investigate the function of H19 on CRC metastasis and invasion, and assess the association between H19 and the RAS‑MAPK signaling pathway. The migration and invasion of CRC cells were analyzed using Transwell migration and invasion assays. To elucidate the association between H19 and the RAS‑MAPK signaling pathway and determine the expression level of active RAS in CRC cells, Ras activity assay and Western blotting were performed. It was indicated that the overexpression of H19 was able to increase the migration and invasion of CRC cells and this may be mediated by the regulation of RAS activation. Therefore, H19 may promote metastasis and invasion in colorectal cancer by activating the RAS‑MAPK signaling pathway. [ABSTRACT FROM AUTHOR]

The long non‑coding RNA (lncRNA) differentiation antagonizing non‑protein coding RNA (DANCR) has been reported to be a novel potential biomarker for colon cancer prognosis. However, its functional role in colon cancer remains unknown. In the present study, DANCR expression in colon cancer cell lines was determined by reverse transcription‑quantitative polymerase chain reaction. Cell Counting kit‑8 assay, colony formation assay, flow cytometry, Hoechst 33258 staining and western blotting were utilized to investigate the effect and mechanism of DANCR in the regulation of colon cancer growth. Establishment of a xenograft tumor model followed by terminal deoxynucleotidyl transferase (TdT) dUTP nick‑end labeling assay and immunohistochemical staining were performed to confirm the findings in vitro. DANCR was revealed to be overexpressed in all human colon cancer cell lines. Silencing DANCR by small interfering RNA significantly inhibited cell proliferation and colony formation. Flow cytometry analyses and Hoechst 33258 staining revealed that apoptosis was induced upon DANCR‑knockdown. Silencing DANCR was revealed to efficiently impair colon tumor growth by promoting caspase 3 expression and tumor apoptosis. In summary, the results of the present study demonstrated that DANCR is a potential therapeutic target in colon cancer. [ABSTRACT FROM AUTHOR]

Colorectal cancer (CRC) is the third leading cause of cancer‑associated mortality worldwide. Genipin is a medicinal herb compound derived from the gardenia fruit, which has been reported to exhibit antitumor activity against several types of cancer. The aim of the present study was to investigate the antitumor effect of genipin on colon cancer and the underlying molecular mechanisms. Genipin significantly inhibited the viability of HCT116 and SW480 cells in vitro in a dose‑ and time‑dependent manner. Additionally, genipin was able to significantly inhibit tumor growth in nude mice with xenografts of HCT116 and SW480 cells. The inhibition of tumor growth by genipin treatment was coupled with G0/G1 cell cycle arrest, apoptosis induction, increased reactive oxygen species damage and loss of mitochondrial membrane potential. Further investigation of genipin‑treated HCT116 cells revealed that the expression of p53, Bax and cleaved caspase‑3 in genipin‑treated cells was increased compared with the vehicle control, whereas B‑cell lymphoma‑2 expression appeared to be lower in genipin‑treated cells. Collectively, the findings of the present study indicate that genipin was able to decrease proliferation and promote apoptosis in colon cancer cells by inducing the p53/Bax‑mediated signaling pathway. Therefore, genipin may be used as a novel therapeutic agent in the treatment of CRC. [ABSTRACT FROM AUTHOR]

The development of colorectal cancer (CRC) involves genetic and epigenetic modifications, and aberrant DNA methylation within gene promoters is a primary mediator of epigenetic inheritance in CRC. The present study evaluated whether promoter methylation of four CRC candidate genes [protocadherin γ subfamily A12 (PCDH‑γ‑A12), solute carrier family 19 A 1 (SLC19A1), cAMP responsive element binding protein (CREB) and cylindromatosis (CYLD) contributed to the risk and metastasis of CRC by screening a total of 42 CRC and 42 adjacent normal tissue samples. DNA methylation was measured by methylation‑specific polymerase chain reaction (MSP). Polymerase chain reaction (PCR) products were bisulfite converted and validated by sequencing. The χ2 test was employed to assess the association between promoter methylation and a series of clinicopathological characteristics. The promoters of PCDH‑γ‑A12 and SLC19A1 were observed to be more frequently methylated in CRC tissues than normal tissues. In addition, significantly higher methylation of the PCDH‑γ‑A12 and SLC19A1 promoters was also observed in CRC tissues with lymph metastasis compared with those without lymph metastasis. In addition, no association was observed between CREB and CYLD methylation and the occurrence and metastasis of CRC. These results suggest that the hypermethylation of the PCDH‑γ‑A12 and SLC19A1 promoters may contribute to the occurrence and metastasis of CRC in the Han Chinese population. [ABSTRACT FROM AUTHOR]

Germline mutations of DNA mismatch repair gene human MutS homolog 2 (hMSH2) are associated with hereditary nonpolyposis colorectal cancer (HNPCC). A total of one-third of these mutations are missense mutations. Several hMSH2 missense mutations have been identified in patients in East Asia, although their function has not been evaluated. In the present study, the role of ten hMSH2 missense mutations in the pathogenesis of colorectal cancer was examined. The hMSH2/hMSH6 protein interaction system was established using yeast two-hybrid screening. Next, the missense mutations were analyzed for their ability to affect the protein interaction of hMSH2 with its partner hMSH6. Additionally, the Sorting Intolerant from Tolerant tool was applied to predict the effects of different amino acid substitutions. The results demonstrated that certain hMSH2 mutations (L173R and C199R) caused a significant functional change in the human hMutSα complex and were identified to be pathological mutations. The Y408C, D603Y, P696L and S703Y mutations partially affected interaction and partly affected the function of hMSH2. The remaining four variants, T8M, I169V, A370T and Q419K, may be non-functional polymorphisms or could affect protein function through other molecular mechanisms. The present study evaluated the functional consequences of previously unknown missense mutations in hMSH2, and may contribute to improved clinical diagnosis and mutation screening of HNPCC. [ABSTRACT FROM AUTHOR]

Triple-negative breast cancer (TNBC) is extremely aggressive and associated with poor prognosis. There are no known predictive or prognostic markers for TNBC. Inhibition of tumor protein P53 (TP53) has been demonstrated to increase the levels of cluster of differentiation 117 (CD117) in human colorectal cancer cells. However, the function of TP53 in the regulation of CD117 in TNBC has, to the best of our knowledge, not been reported. In the present study, the association between the expression of CD117 protein and TP53 mutations was investigated, and their prognostic value in patients with TNBC was assessed. A total of 58 TNBC and 48 non-TNBC breast cancer tissue samples were assessed for the expression of CD117, p53 and TP53 mutations. The marker of proliferation Ki-67 (MKI67) proliferation index and vascular invasion index (obtained by measuring D2-40 and CD34) was investigated via immunohistochemistry, and mutations in exons 4-8 of TP53 were measured using direct sequencing. Associations between CD117 and p53 levels or TP53 mutations and clinical parameters were statistically evaluated. The rates of CD117 or MKI67 positivity, CD117+/TP53 missense mutation+, TP53 missense mutations or recurrence were significantly higher in patients with TNBC than in patients with non-TNBC. In TNBC tissues, the presence of CD117 was associated with TP53 missense mutations (P=0.031), vascular invasion, recurrence and MKI67. CD117+/TP53 missense mutation+ also associated with vascular invasion, recurrence and MKI67. Under univariate analysis, MKI67, vascular invasion, CD117, CD117+/TP53 missense mutation+ and TP53 missense mutations were associated with the overall survival of patients with TNBC. Multivariate analysis revealed that vascular invasion and CD117+/TP53 missense mutation+ in primary tumors were independent prognostic factors in patients with TNBC. In conclusion, CD117+/TP53 missense mutation+ was associated with MKI67, vascular invasion and tumor recurrence in TNBC. The presence of CD117 and TP53 missense mutations together in the primary tumors was an independent prognostic factor for survival of patients with TNBC. [ABSTRACT FROM AUTHOR]

Metastasis is the primary cause of mortality in colorectal cancer (CRC), the mechanism of which remains unclear. In the present study, by detecting mRNA expression using a reverse transcription-quantitative polymerase chain reaction (qPCR), it was revealed that sterol regulatory element-binding protein 1 (SREBP1) is highly expressed in CRC. Using a cell wound healing assay and a cell invasion assay, a novel metastasis-promoting role for SREBP1 in CRC was identified. Furthermore, snail family transcriptional repressor 1 (SNAIL) was identified as a key downstream effector of SREBP1 in CRC by the use of small interfering RNA against SNAIL. Additionally, using co-immunoprecipitation and chromatin immunoprecipitation-qPCR assays, it was demonstrated that SREBP1 interacts with c-MYC to enhance the binding of c-MYC to the promoter of the mesenchymal gene, SNAIL, thereby increasing SNAIL expression and accelerating epithelial-mesenchymal transition. These results indicated a novel role for SREBP1 and provide insight into the regulatory mechanisms of the c-Myc oncogene in CRC, which may function as a potential therapeutic target for CRC treatment. [ABSTRACT FROM AUTHOR]

Colorectal cancer is one of the most common malignancies. Aberrant expressed microRNAs (miRNAs) have been demonstrated to have strong associations with colorectal cancer by repressing their targets. Therefore, miRNAs are thought to have significant promise in the diagnosis and prognosis of colorectal cancer. Previous studies indicated that miR-155 and collagen triple helix repeat containing 1 (CTHRC1) were both involved in pathogenesis of colorectal cancer, but the underlying mechanisms of miR-155 and CTHRC1 are still unknown. The present study aimed to investigate the biological functions of miR-155 and CTHRC1 in colorectal cancer. Reverse transcription-quantitative polymerase chain reaction was used to examine miR-155 and CTHRC1 expression levels. A dual-luciferase reporter assay was applied to verify the target interaction between miR-155 and CTHRC1. Proliferation, cell cycle, apoptosis, cell migration and invasion were measured using the MTT assay, flow cytometry and Transwell assays, respectively. Results showed that miR-155 expression was decreased, but CTHRC1 expression was increased in colorectal cancer tissue and cell lines. Furthermore, it was demonstrated that miR-155 negatively regulated CTHRC1. Additionally, miR-155 overexpression suppressed cell proliferation, induced cell cycle arrest and promoted cell apoptosis, while an inhibitor of miR-155 facilitated cell proliferation and cell cycle and repressed apoptosis. Transwell experiments indicated that miR-155 inhibited the cell migratory and invasive abilities of HT-29 cells, but miR-155 inhibitor enhanced these abilities of HT-29 cells. These results suggested that miR-155 prevented colorectal cancer progression and metastasis via silencing CTHRC1 in vitro, which provides evidence for miR-155 and CTHRC1 as a novel anti-onco molecular target for the treatment of colorectal cancer in the future. [ABSTRACT FROM AUTHOR]

Silent information regulator 6 (SIRT6) is broadly considered as a tumor suppressor due to its function in the suppression of oncogene expression. However, the role of SIRT6 in colorectal cancer stem cells (CSCs) remains uncharacterized. In the present study, it was demonstrated that SIRT6 expression was reduced in colorectal CSCs. Overexpression of SIRT6 in colorectal CSCs did not induce cell apoptosis. However, SIRT6 significantly inhibited cell proliferation, colony formation and induced G0/G1 phase arrest in colorectal CSCs. In addition, SIRT6 repressed the expression of cell division cycle 25A (CDC25A), an oncogenic phosphatase. Chromatin immunoprecipitation experiments indicated that SIRT6 directly bound to the CDC25A promoter and decreased the acetylation level of histone H3 lysine 9. Altogether, these data indicated that SIRT6 inhibits colorectal cancer stem cell proliferation by targeting CDC25A. [ABSTRACT FROM AUTHOR]

Postoperative monitoring for patients with colorectal cancer (CRC) requires sensitive biomarkers that are associated with medical response and adjuvant therapy following surgery. Conventional tumor biomarkers [including carcinoembryonic antigen (CEA), CA19-9 and CA125] are widely used, but none of the markers provide high sensitivity or specificity. Previous studies indicated that circulating tumor DNA (ctDNA) is useful for postoperative monitoring of patients with cancer. However, the majority of previous studies involved patients with lung cancer, and therefore further studies are required which investigate patients with CRC. The present study enrolled 11 patients with CRC. All patients underwent surgery, and a number of patients were treated with postoperative chemotherapy. Tumor tissues and serial blood samples were collected from each patient, and somatic mutations of each sample were obtained using next-generation sequencing. The mutation landscape and dynamic changes in mutations for each patient were analyzed, and these results were compared with the changes of CEA levels. A number of driver genes were selected, including tumor protein P53 (TP53), APC and KRAS, to monitor the postoperative outcome of the 11 patients with CRC. Driver mutations were detected in preoperative plasma in 7 patients, with markedly decreased mutation rates detected in postoperative plasma compared with preoperative plasma. Driver mutations were not detected in 4 patients in the preoperative or postoperative plasma. In 1 patient with metastatic rectal cancer, the rate of TP53 mutation increased from 8.95 (preoperative) to 71.4% (postoperative), and a new phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit α mutation emerged. This patient succumbed to mortality six months following surgery, however there were no marked changes in CEA levels during periodic detection of CEA levels. In summary, ctDNA has a high sensitivity and specificity in prediction of the prognosis of patients with CRC. [ABSTRACT FROM AUTHOR]

The Wnt signaling pathway is aberrantly activated in the majority of human colorectal tumors. β‑catenin, a key component of the Wnt signaling pathway, interacts with the T‑cell factor/lymphoid enhancer‑binding factor family of transcription factors and activates transcription of Wnt target genes. Sp5 is one of the Wnt target genes, and its expression is commonly upregulated in colon cancer cells. The present study demonstrates that the expression of Sp5 is not upregulated in the colon cancer cell line HCT116, in which Wnt signaling is constitutively activated. Furthermore, the results demonstrate that Sp5 has the potential to inhibit cell proliferation through upregulation of the cell cycle inhibitor p27. These findings suggest that HCT116 cells downregulate Sp5 to avoid p27‑mediated growth arrest. [ABSTRACT FROM AUTHOR]

The present study investigated the expression and clinical significance of flavin‑containing monooxygenase 5 (FMO5) in colorectal cancer (CRC). The expression of FMO5 was detected by immunohistochemistry in 208 colon cancer tissues and 8 normal colon tissues. Then, the correlations of FMO5 expression with several clinicopathological features were evaluated. FMO5 mRNA expression from The Cancer Genome Atlas dataset was assessed for further validation. In addition, the association of the expression of FMO5 with prognosis was further evaluated by Kaplan‑Meier survival curves and Cox proportional hazards model. The FMO5 protein level in colon cancer tissues was significantly higher than that in normal colon tissues (P<0.001). Overexpression of FMO5 was associated with an advanced clinical stage of cancer (P=0.018) and lymph node metastasis (P=0.03). The TCGA dataset also demonstrated that FMO5 was upregulated in CRC with advanced clinical stage (P=0.047), lymph node metastasis (P=0.045) and distant metastasis (P=0.030). The Kaplan‑Meier survival curves showed that higher FMO5 mRNA indicated a shorter overall survival in patients with CRC compared with a low expression of FMO5 (P=0.029). Cox proportional hazards regression revealed that a high FMO5 mRNA level served as an independent prognostic factor for patients with CRC (hazard ratio, 2.865; 95% confidence interval, 1.116‑7.355; P=0.029). A high expression of FMO5 may serve roles in colorectal carcinogenesis and distant metastasis. FMO5 may be an independent predictive factor for the prognosis of CRC. [ABSTRACT FROM AUTHOR]

Hypoxia is a common characteristic of solid tumors. Previous studies have reported that the tumor invasion‑associated factor, AMPK‑related protein kinase 5 (ARK5), is associated with a poor prognosis in colon cancer. However, whether or not ARK5 is involved in hypoxia is unclear. The aim of present study was to investigate the association between the expression of ARK5 and that of hypoxia‑inducible factor 1‑α (HIF1‑α). Samples from 60 patients with colon cancer were collected and immunohistochemistry was used to detect the expression of ARK5 and HIF1‑α within them. Western blot analysis and reverse transcription polymerase chain reaction were used to detect the expression of ARK5 in an SW480 cell line under hypoxic conditions. Cell Counting kit‑8 and Transwell assays were used to study the function of ARK5 under hypoxic conditions. According to the immunohistochemistry results, ARK5 and HIF1‑α staining was significantly associated with Tumor‑Node‑Metastasis stage, tumor grade, lymph node metastasis and liver metastasis. Spearman's correlation analysis revealed a correlation between the expression of ARK5 and that of HIF1‑α. This finding was also verified under hypoxic conditions in the SW480 cell line, in which the expression of ARK5 increased over time. Further cellular function experiments revealed that suppression of ARK5 inhibited cell viability and migration under hypoxic conditions. The present study has suggested that ARK5 expression in colon cancer cells is upregulated by HIF1‑α under hypoxic conditions and that ARK5 serves an important role in cell proliferation and migration under hypoxic stress. [ABSTRACT FROM AUTHOR]

It remains unknown whether blockade of B‑Raf proto‑oncogene, serine/threonine kinase (BRAF)V600E signaling and MET proto‑oncogene, receptor tyrosine kinase (c‑Met) signaling is effective in suppressing the growth of human colorectal cancer (CRC) cells. The present study investigated the effects of the vemurafenib alone and in combination with c‑Met inhibitor PHA‑665752 on the growth of human CRC cells in vitro and in mouse xenografts. HT‑29 and RKO CRC cell lines with BRAFV600E mutations and mice bearing HT‑29 xenografts were treated with vemurafenib in the absence or presence of PHA‑665752. Cell viability and cycle phase were respectively examined by using the MTT and flow cytometry assay. Immunohistochemistry was conducted to detect the protein expression levels of hepatocyte growth factor (HGF), phosphorylated (p)‑c‑Met, p‑AKT serine/threonine kinase (AKT) and p‑extracellular signal‑regulated kinase (p-ERK). The MTT assay demonstrated that the growth of RKO and HT‑29 cells was inhibited by PHA‑665752 in a time‑ and dose‑dependent manner (P<0.05), however no significant suppressive effects were observed with vemurafenib. Relative to the PHA‑665752 or vemurafenib stand‑alone treatment groups, the combination of PHA‑665752 and vemurafenib had a significant inhibitory effect on the proliferation of CRC cell lines (P<0.05). The mean tumor volume in mice treated with vemurafenib in combination with PHA‑665752 was significantly smaller compared with those treated with only vemurafenib or PHA‑665752 (P<0.05). Flow cytometry assay revealed that the G0/G1 phase frequency was significantly increased in the combination group compared with any other treatment groups (P<0.05). Immunohistochemistry demonstrated that vemurafenib in combination with PHA‑665752 effectively induced the expression of p‑c‑Met, p‑AKT and p‑ERK, however had no effect on HGF. [ABSTRACT FROM AUTHOR]

T1 colorectal carcinomas (CRCs) are an initial site of metastatic spread. Various risk factors for lymph node metastasis have been investigated in T1 CRCs. However, the major step in the entire process of metastasis remains unclear. In terms of carcinoma invasion and metastasis, matrix metalloproteinases (MMPs) have recently gained increasing attention. Notably, MMP‑7 is frequently overexpressed in CRCs, but its implication has not been determined in T1 CRCs yet. The present study aimed to clarify the associations between the pathological risk factors of T1 CRCs and MMP‑7. In the current study, 211 lesions of T1 CRC that were resected endoscopically or surgically at Showa University Northern Yokohama Hospital (Yokohama, Japan) between April 2008 and December 2009 were retrospectively analyzed. MMP‑7 was immunostained and evaluated by its frequency of expression. Pathological factors of T1 CRCs were analyzed in association with MMP‑7 expression. Furthermore, the ultrastructural alterations of carcinoma invasion were examined using low vacuum‑scanning electron microscopy (LV‑SEM). MMP‑7 expression was associated with venous invasion (P=0.005), and LV‑SEM revealed the disappearance of the normal structure of collagen and elastic fibers of veins invaded by tumor cells expressing MMP‑7. At the invasive front, MMP‑7 has a vital role in carcinoma invasion, correlating with venous invasion of T1 CRCs. [ABSTRACT FROM AUTHOR]

Tumor‑infiltrating immune cells are heterogeneous and consist of characteristic compartments, including T helper (Th)1 and regulatory T (Treg) cells that exhibit distinctive biological functions. The present study investigated the profile of infiltrating immune cells from surgically removed tumor tissues from patients with colorectal cancer. The characteristic transcription factors of Th1 and Th2 cells, Treg cells, Th17 cells and T follicular helper (Tfh) cells were analyzed. The results demonstrated that a marked increased number of Treg cells presented in tumor infiltrates when compared with non‑tumor adjacent tissues. An increased number of Th1 and Tfh cells existed in tumor infiltrates compared with non‑tumorous adjacent tissues, while the infiltration of Th17 and Th2 cells was similar between tumor and non‑tumor adjacent tissues. Furthermore, there were an increased number of Treg cells in tumors with low infiltration compared with those with high infiltration. The expression of CXC motif chemokine (CXC) receptor 3, CXC ligand (CXCL)L9 and CXCL10 was significantly increased on infiltrating T cells in tumors with high infiltration as compared with those with low infiltration. Macrophages exhibited a dominant M2 phenotype in tumor infiltrates of colorectal cancer, whereas a balanced M1 and M2 phenotype presented in macrophages from the peripheral blood. In vitro stimulation of macrophages isolated from tumor tissue of colorectal cancer with granulocyte macrophage colony‑stimulating factor and lipopolysaccharide did not drive to an inflammatory phenotype. The results provide insights into the pattern of immune cell infiltration in Chinese patients with colorectal cancer. It may be beneficial that patients with colorectal cancer are screened for the defined profile along with the expression of CXCL9 and CXCL10 in order to achieve better efficacy in clinical applications of immune‑based therapy, including anti‑programmed cell death protein 1 therapy. [ABSTRACT FROM AUTHOR]

Caudal type homeobox 2 (CDX2) has been well‑established as a diagnostic marker for colorectal cancer (CRC); however, less is known about its regulation, particularly its potential interactions with the DNA repair proteins, adenomatous polyposis coli (APC) and β‑catenin, in a non‑transcriptional manner. In the present study, the protein expression of CDX2 was analyzed, depending on the expression of the DNA repair proteins, mismatch repair (MMR), O6‑methylguanine DNA methyltransferase (MGMT) and excision repair cross‑complementing 1 (ERCC1), and its importance in Wnt signaling was also determined. A total of 101 liver metastases were punched into tissue microarray (TMA) blocks and serial sections were cut for immunohistochemistry. For each protein, an immunoreactive score was generated according to literature data and the scores were fitted to TMA. Subsequently, statistical analysis was performed to compare the levels of expression with each other and with clinical data. CDX2 loss of expression was observed in 38.5% of the CRC liver metastasis cases. A statistically significant association between CDX2 and each of the investigated MMRs was observed: MutL Homolog 1 (P<0.01), MutS protein Homolog (MSH) 2 (P<0.01), MSH6 (P<0.01), and postmeiotic segregation increased 2 (P=0.040). Furthermore, loss of MGMT and ERCC1 was also associated with CDX2 loss (P=0.039 and P<0.01, respectively). In addition, CDX2 and ERCC1 were inversely associated with metastatic tumor size (P=0.038 and P=0.027, respectively). Sustained CDX2 expression was associated with a higher expression of cytoplasmic/membranous β‑catenin and with nuclear APC expression (P=0.042 and P<0.01, respectively). In conclusion, CDX2 loss of expression was not a rare event in liver metastasis of CRC and the results suggested that CDX2 may be involved in mechanisms resulting in the loss of DNA repair protein expression, and in turn methylation; however, its exact function in this context remains to be elucidated. [ABSTRACT FROM AUTHOR]

High levels of tumor‑associated calcium signal transduction protein (TROP)‑2 have been demonstrated to be strongly associated with tumor necrosis factor (TNF)‑α levels in colon cancer. In the present study, the effect of TNF‑α on the regulation of TROP‑2 expression and its effect in colon cancer cell migration and invasion were investigated in vitro. TROP‑2 protein levels were evaluated in HCT‑116 human colon cancer cells cultured with various concentrations of TNF‑α using western blot analysis. Changes in the migratory and invasive potential of the cells were evaluated using a wound healing and transwell assay, respectively. Then, TROP‑2 expression was downregulated in cells by use of siRNA, and TROP‑2 knockdown was confirmed at the mRNA and protein level by reverse transcription‑quantitative polymerase chain reaction and western blotting, respectively. The migration and invasion potential of cells transfected with TROP‑2 siRNA was also evaluated. Levels of several mitogen‑activated protein kinase proteins, namely p38, c‑Jun N‑terminal kinase (JNK) and extracellular signal‑regulated kinase (ERK), were detected in cells treated with TNF‑α using western blot analysis. The results demonstrated that TROP‑2 protein levels increased in cells treated with lower concentrations of TNF‑α, but decreased in cells treated with higher concentrations of TNF‑α, compared with untreated control. Maximum TROP‑2 levels were observed in cells treated with 20 μg/l TNF‑α. Migration and invasion were enhanced in cells treated with 20 μg/l TNF‑α. When TROP‑2 was silenced in colon cancer cells by siRNA, migration and invasion were significantly decreased compared with control cells. TNF‑α stimulation activated the ERK1/2 pathway, but did not significantly affect p38 and JNK phosphorylation levels. Treatment with a specific ERK1/2 inhibitor suppressed the TNF‑α‑induced upregulation of TROP‑2 and the TNF‑α‑induced colon cancer cell migration and invasion. In conclusion, the present results demonstrated that low concentrations of TNF‑α significantly enhanced colon cancer cell migration and invasion by upregulating TROP‑2 via the ERK1/2 signaling pathway. [ABSTRACT FROM AUTHOR]

Lymphatic and hematogenous spread are the most common ways for tumors to metastasize. Angiogenesis is essential for tumor growth and metastasis. Vascular endothelial growth factor (VEGF) particularly VEGF‑A is important in the process of angiogenesis. The current research has indicated that thalidomide (THD) may be able to inhibit angiogenesis, stimulate the activity of the immune system and inhibit the adherence of cancer cells to stromal cells. These changes may lead to suppression of tumor occurrence and development. To date, to the best of our knowledge, the effects of THD on colon cancer SW480 cells have not been reported. In the present study, the effects of THD and a combination of THD and oxaliplatin (L‑OHP) on the proliferation of SW480 cells have been investigated. Furthermore, the expression of VEGF‑A and hypoxia‑inducible factor 1 (HIF‑1) was analyzed using MTT assay, quantitative polymerase chain reaction and western blot analysis. The results indicated that THD was able to inhibit SW480 cells in dose‑and‑time dependent manner and inhibit the expression of VEGF‑A and HIF‑1α. Furthermore, treatment with THD and L‑OHP had synergistic inhibitory effect, which may provide a novel treatment strategy for advanced colorectal cancer. [ABSTRACT FROM AUTHOR]

KRAS mutations serve a function in tumorigenesis of colorectal cancer (CRC) and guide the use of targeted drugs. However, the prognostic value of KRAS mutations and their subtypes remain controversial. The present study aimed to investigate the correlations between KRAS mutations and clinicopathological characteristics, and their prognostic significance in Chinese patients with metastatic CRC (mCRC). A total of 135 patients with mCRC were analyzed for KRAS mutations. Mutations in codon 12 and 13 were identified in 45 (33.3%) patients. Only 3 patients harbored a mutation of V600E. Compared with male patients, KRAS codon 12 mutations were more common in female patients (P<0.05). KRAS codon 13 mutations tended to arise in right‑sided compared with left‑sided colon cancer (P<0.05). Survival analysis was performed in 101 patients receiving primary tumor resection. Compared with KRAS codon 12 wild‑type, codon 12 mutations were markedly correlated with a poorer survival (log‑rank P=0.002). No prognostic significance was revealed in codon 13 mutations. In univariate analysis, mortality risk was significantly increased by subtypes of G12D and G12V [hazard ratio (HR) =2.313, 95% confidence interval (CI) =1.069‑5.004, P=0.03; HR=2.621, 95% CI=1.057‑6.497, P=0.04, respectively]. The results of the present study suggested that codon 12 mutations, in particular G12D and G12V, predicted a negative prognosis in Chinese patients with mCRC. These findings require further confirmation via prospective studies with larger samples. [ABSTRACT FROM AUTHOR]

The role of long non‑coding RNAs (lncRNAs) in the carcinogenesis and progression of tumors has been receiving increasing attention. Colon cancer‑associated transcript 2 (CCAT2), a type of oncogenic lncRNA, is regarded as a novel biomarker of poor prognosis and metastasis in various types of cancer. However, the molecular contributions of CCAT2 to gastric cancer (GC) progression remain largely unclear. The aim of the present study was to demonstrate the effect of silencing CCAT2 on the biological behavior of GC BGC‑823 cells and illustrate the potential underlying molecular mechanisms. A short hairpin RNA interference plasmid pRNAT‑U6.1‑CCAT2 targeting CCAT2 was successfully constructed. At 48 h after transfection with the interference plasmid, the survival rate of BGC‑823 cells was significantly decreased, as determined by the MTT assay. In addition, RT‑qPCR results revealed that CCAT2 gene expression was effectively suppressed by the transfection, while POU domain class 5 transcription factor 1B (POU5F1B) gene expression was significantly decreased. Terminal deoxynucleotidyl transferase dUTP nick end labeling assay further revealed that the apoptotic index was significantly higher in the interference group. Western blot analysis also demonstrated that the expression of beclin‑1 protein was significantly increased, whereas the expression levels of phosphoinositide 3‑kinase (PI3K) and mammalian target of rapamycin (mTOR) proteins were downregulated in the interference group. In conclusion, CCAT2 was able to positively regulate the expression of POU5F1B gene. Furthermore, silencing of CCAT2 gene inhibited the proliferation of BGC‑823 cells, as well as induced apoptosis and autophagy in BGC‑823 cells, by suppression of the PI3K/mTOR signaling pathways. [ABSTRACT FROM AUTHOR]

Colorectal cancer is a common malignant tumor of the digestive tract with high morbidity and mortality rates. The aim of the present study was to examine the expression level of KiSS-1 in tumor tissues of patients with colorectal cancer, and to explore the relationship with the clinicopathology and prognosis of patients with colorectal cancer. Frozen tumor tissue and corresponding cancer-adjacent normal tissue specimens were selected from 56 patients with colorectal cancer who were treated in the Department of Surgery of our hospital from May 2009 to December 2011. The expression levels of KiSS-1 messenger ribonucleic acid (mRNA) in tumor tissues and cancer-adjacent normal tissues were detected by reverse transcriptase‑quantitative polymerase chain reaction (RT-qPCR). The expression levels of KiSS-1 proteins in colorectal cancer tissues and cancer-adjacent normal tissues were further detected by immunohistochemistry. In addition, the association of the expression level of KiSS-1 proteins in tissues of colorectal cancer patients with pathological parameters and the prognosis of patients with colorectal cancer was analyzed combined with clinical data. The RT-qPCR results showed that the expression of KiSS-1 mRNA in colorectal cancer tissues was significantly lower than that in cancer-adjacent normal tissues (P<0.05). Immunohistochemistry results indicated that the positive expression rate of KiSS-1 proteins in colorectal cancer tissues (26.79%) was significantly lower than that in cancer-adjacent normal tissues (80.36%). The low expression of KiSS-1 in colorectal cancer tissues was associated with the degree of differentiation, invasion and metastasis, as well as clinical staging. The 5-year overall survival rate of patients with colorectal cancer was 55.36% (31/56). The univariate survival analysis showed that patients with lowly expressed KiSS-1 had worse prognosis. The low expression of KiSS-1 is closely associated with the occurrence and development of colorectal cancer, especially to the degree of differentiation, invasion and metastasis, as well as clinical staging. Thus, the expression of KiSS-1 in colorectal cancer tissues can be used as a reference for the prognosis of colorectal cancer, and KiSS-1 is a potential new target for the treatment of colorectal cancer. [ABSTRACT FROM AUTHOR]

Enhancer of zeste homolog 2 (EZH2), the critical component of polycomb group protein family, has been demonstrated to be overexpressed in various types of human cancer, including hepatocellular carcinoma, breast, bladder and lung cancer. The mechanism of how EZH2 promotes oncogenesis has also been well studied. However, little is known about the role of EZH2 in colorectal cancer (CRC). The main purpose of the present study was to analyze the association between EZH2 expression and the clinicopathological features of CRC. Therefore, the mRNA and protein expression levels were analyzed in tumor tissues and adjacent non‑cancerous tissues by reverse transcription‑quantitative polymerase chain reaction (RT‑qPCR) and western blot analysis. The expression of EZH2 was demonstrated to be significantly increased in tumor tissues compared with adjacent noncancerous tissues, according to the results of western blot analysis and RT‑qPCR in the majority of cases. Patients with low EZH2 expression had a longer overall survival rate compared with those with high EZH2 expression. An analysis of the association between clinicopathological features and EZH2 expression indicated that high EZH2 expression was significantly associated with tumor stage, tumor size, histological differentiation and lymph node metastasis. Multivariate analysis demonstrated that high EZH2 expression was an independent predictor of overall survival. In conclusion, to the best of our knowledge, the data presented in the present study is the first to indicate that EZH2 is upregulated in CRC and may serve as a predictor of poor outcome for patients with CRC. [ABSTRACT FROM AUTHOR]

Homeobox A (HOXA) cluster genes, members of the HOX family, perform an important role in normal organ development. It has previously been reported that HOXA gene expression in various types of cancer is associated with poor patient outcomes. However, the role of HOXA genes, as well as their expression, in colorectal cancers (CRC) remains unknown. Therefore, the present study investigated HOXA gene expression in patients with CRC and revealed that HOXA9 expression was significantly increased in tumor tissues compared with non‑tumor tissues. Additionally, the functional role of HOXA9 was assessed by knocking down the HOXA9 gene in CRC cells and by evaluating cell growth. Regarding gene expression, cases with positive HOXA9 expression (as detected by immunohistochemical staining) were significantly associated with higher TNM stage and positive lymph node metastasis, although no association was observed between increased HOXA9 levels and the rate of overall survival in the present cohort. Regarding the functional role, HOXA9 expression was demonstrated to be upregulated in patients with CRC and was associated with lymph node metastasis. [ABSTRACT FROM AUTHOR]

Actin‑related protein 2/3 complex subunit 4 (ARPC4) acts as an actin nucleator in actin cytoskeleton branching and contributes to cell migration. ARPC4 has previously been demonstrated to be abnormally expressed in various colorectal carcinoma cell lines, particularly SW620 cells. The present study explored the biological action and the possible mechanisms underlying the function of ARPC4 in the progression of carcinoma. The proliferation and migration of SW620 cells transfected with ARPC4‑specific short interfering (si)RNAs were assessed using western blot, cell counting, flow cytometry and transwell assays. SW620 cells exhibited the highest ARPC4 expression of the cell lines investigated, and siRNA538 was the most effective of the siRNAs considered. The results of the present study demonstrated that ARPC4‑silencing exhibited a significant effect on the capacity of cells for migration, but did not affect their proliferative ability. ARPC4‑silencing inhibited human SW620 cell migration, but not proliferation, in vitro, suggesting that ARPC4 may be a putative therapeutic target for colorectal carcinoma. [ABSTRACT FROM AUTHOR]

Increasing evidence demonstrates that microRNAs (miRNAs/miRs), a type of non-coding small RNA, can regulate tumor cell migration, invasion and metastasis, and may therefore serve a major function in the occurrence and development of tumors. The present study investigated the effect of miR-383 on the proliferation, migration and invasion of colon cancer HT-29 and LoVo cell lines. The expression of miR-383 in colon cancer and adjacent non-tumor tissues was examined by reverse transcription-quantitative polymerase chain reaction. MiR-383 upregulation was stimulated by transfection with a miR-383 mimic. Cell proliferation was measured with MTT and colony formation assays, and cell migration and invasion potential were examined by Transwell chamber assays. A proliferating-inducing ligand (APRIL), myeloid cell leukemia-1 and cyclooxygenase-2 protein expression was analyzed by western blotting. The expression of miR-383 was decreased in colon cancer tissues compared with adjacent non-tumor tissues (P<0.05). Transfection with a miR-383 mimic suppressed proliferation and inhibited cell migration and invasion in HT-29 and LoVo colon cancer cell lines. Overexpression of miR-383 in HT-29 and LoVo cells resulted in the suppression of APRIL protein expression. In conclusion, miR-383 was downregulated in colon cancer. The upregulation of miR-383 inhibited proliferation, migration and invasion of colon cancer cells, potentially through the regulation of target gene APRIL. [ABSTRACT FROM AUTHOR]

The CDw75 epitope is an α(2,6) sialylated antigen overexpressed in colorectal cancer (CRC), where its expression correlates with the progression of the disease. The CDw75 epitope is located mainly in N-glycoproteins, whose identity remains unknown. The aim of the present study was to identify proteins with the CDw75 epitope as a strategy to deepen the understanding of molecular pathogenesis of CRC and to identify novel biomarkers for this disease. For this purpose, a two-dimensional electrophoresis approach was employed. Protein spots in the gels were matched to the corresponding CDw75 positive spots in the immunoblotted polyvinylidene difluoride membranes, and further identification of the protein species was performed by mass spectrometry. Additionally, one-dimensional western blotting experiments were performed to verify the expression of these candidate proteins in the colorectal tissue and their coincidence in molecular mass with the CDw75-positive bands. The findings of the present study indicate that haptoglobin and the keratins 8 (K8) and 18 (K18) are proteins with the CDw75 epitope in the colorectal tissue from CRC patients and also suggest novel functions and cellular locations for these proteins in the colorectal tissue and in relation to CRC. [ABSTRACT FROM AUTHOR]

Abnormal glucose metabolism is critical in colorectal cancer (CRC) development. Expression of the pyruvate kinase (PK) M2 isoform, rather than the PKM1 isoform, serves important functions in reprogramming the glucose metabolism of cancer cells. Preferential expression of PKM2 is primarily driven by alternative splicing, which is coordinated by a group of splicing factors including heterogeneous nuclear ribonucleoprotein (hnRNP)A1, hnRNPA2 and RNA binding motif containing. However, the underlying molecular mechanisms associated with cancer cell expression of PKM2, instead of PKM1, remain unknown. The mRNA levels of PKM isoform and glucose metabolism were analyzed in CRC cells. The results of the present study indicated that S6 kinase 2 (S6K2) promotes glycolysis and growth of CRC cells by regulating alternative splicing of the PKM gene. In addition, chromatin immunoprecipitation assay indicated that S6K2 phosphorylation of Ser6 of hnRNPA1 facilitated hnRNPA1 binding to the splicing site of the PKM gene. As a result, cancer cells preferentially expressed the PKM2 isoform, instead of the PKM1 isoform. Furthermore, Cox regression analysis demonstrated that the phosphorylation of Ser6 of hnRNPA1 was a predictor of poor prognosis for patients with CRC. Therefore, the results of the present study revealed that the phosphorylation of Ser6 in hnRNPA1 by S6K2 was a novel mechanism underlying glucose metabolic reprogramming, and suggested that S6K2 is a potential therapeutic target for CRC treatment. [ABSTRACT FROM AUTHOR]

The aim of the present study was to explore the clinicopathological and prognostic significance of long non‑coding RNA (lncRNA) colon cancer‑associated transcript 2 (CCAT2) expression in human colorectal cancer (CRC). Expression levels of lncRNA CCAT2 in CRC, adjacent non‑tumor and healthy colon mucosa tissues were detected by quantitative polymerase chain reaction. The disease‑free survival and overall survival rates were evaluated using the Kaplan‑Meier method, and multivariate analysis was performed using Cox proportional hazard analysis. The expression level of lncRNA CCAT2 in CRC tissues was increased significantly compared with adjacent normal tissues or non‑cancerous tissues. CCAT2 expression was observed to be progressively increased between tumor‑node‑metastasis (TNM) stages I and IV. A high level of CCAT2 expression was revealed to be associated with poor cell differentiation, deeper tumor infiltration, lymph node metastasis, distance metastasis, vascular invasion and advanced TNM stage. Compared with patients with low levels of CCAT2 expression, patients with high levels of CCAT2 expression had shorter disease‑free survival and overall survival times. Multivariate analyses indicated that high CCAT2 expression was an independent poor prognostic factor. Therefore, increased lncRNA CCAT2 expression maybe a potential diagnostic biomarker for CRC, and an independent predictor of prognosis in patients with CRC. [ABSTRACT FROM AUTHOR]

Colorectal cancer (CRC) is one of the most frequently occurring malignancies worldwide. The outcomes of patients with similar clinical symptoms or at similar pathological stages remain unpredictable. This inherent clinical diversity is most likely due to the genetic heterogeneity. The present study aimed to create a predicting tool to evaluate patient survival based on genetic profile. Firstly, three Gene Expression Omnibus (GEO) datasets (GSE9348, GSE44076 and GSE44861) were utilized to identify and validate differentially expressed genes (DEGs) in CRC. The GSE14333 dataset containing survival information was then introduced in order to screen and verify prognosis‑associated genes. Of the 66 DEGs, the present study screened out 46 biomarkers closely associated to patient overall survival. By Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway analysis, it was demonstrated that these genes participated in multiple biological processes which were highly associated with cancer proliferation, drug‑resistance and metastasis, thus further affecting patient survival. The five most important genes, MET proto‑oncogene, receptor tyrosine kinase, carboxypeptidase M, serine hydroxymethyltransferase 2, guanylate cyclase activator 2B and sodium voltage‑gated channel a subunit 9 were selected by a random survival forests algorithm, and were further made up to a linear risk score formula by multivariable cox regression. Finally, the present study tested and verified this risk score within three independent GEO datasets (GSE14333, GSE17536 and GSE29621), and observed that patients with a high risk score had a lower overall survival (P<0.05). Furthermore, this risk score was the most significant compared with other predicting factors including age and American Joint Committee on Cancer stage, in the model, and was able to predict patient survival independently and directly. The findings suggest that this survival associated DEGs‑based risk score is a powerful and accurate prognostic tool and is promisingly implemented in a clinical setting. [ABSTRACT FROM AUTHOR]

Catalpol is an effective active ingredient that functions as a diuretic and laxative, and exhibits blood sugar-lowering, liver protective, anti-aging and anticancer effects. In traditional Chinese medicine, catalpol is believed to be Yin nourishing. The anticancer effect of catalpol on human HCT116 colorectal cancer cells were investigated and the mechanism of action was evaluated. Cellular viability was detected using an MTT assay. Caspase-3 and caspase-9 activity, cellular apoptosis and nucleic morphology were analyzed using caspase-3 and caspase-9 activity assay kits, flow cytometric assays and DAPI staining assay, respectively. Western blot analysis was used to measure the protein expressions of phosphatidylinositol 3-kinase (PI3K), phosphorylated-protein kinase B (p-Akt) and Akt. Expression of microRNA-200 was detected using the reverse transcription-quantitative polymerase chain reaction. HCT116 cells were incubated with PI3K inhibitors in order to analyze the effect of catalpol on cell proliferation. Catalpol was able to inhibit HCT116 cell proliferation. Furthermore, catalpol induced apoptosis in HCT116 cells, which depended on the increased activities of caspase-3 and -9. In addition, catalpol reduced the expression of PI3K, p-Akt and Akt in HCT116 cells. However, downregulation of PI3K/Akt decreased the viability of HCT116 cells following treatment with catalpol and enhanced microRNA-200 expression. Catalpol promoted cellular apoptosis in human HCT116 colorectal cancer cells through upregulation of microRNA-200 expression, which depended on a downregulation of the phosphatase and tensin homolog/PI3K-Akt signaling pathway. [ABSTRACT FROM AUTHOR]

C-mannosylation is a unique type of protein glycosylation with a mannose attached to the tryptophan residue via the C-C linkage. Our previous study revealed that dpy-19 like 3 (DPY19L3) acts as a C-mannosyltransferase in human cells. The present study hypothesized that RPE-spondin (RPESP) may be a substrate protein of DPY19L3-mediated C-mannosylation. RPESP has unknown biological functions and has two putative C-mannosylation sites at the W80 and W83 residues; however, to the best of our knowledge, C-mannosylation of RPESP has not previously been investigated. The present study suggested that RPESP is C-mannosylated at W80 and W83 in human cells, whereas gain-of-function experiments using S2 cells revealed that human DPY19L3 catalyzed the C-mannosylation of RPESP at W83 but not W80, which suggested substrate specificity. In addition, the present study detected mRNA expression levels of RPESP in various types of cancer cell lines and high expression levels of RPESP were revealed in certain colorectal cancer cell lines, suggesting that RPESP may have an association with the malignancy of colorectal cancers. [ABSTRACT FROM AUTHOR]

Human telomerase reverse transcriptase (hTERT) expression level may not always correlate with telomerase activity. The present study analyzed hTERT splicing patterns with respect to hTERT and telomerase activity in colorectal cancer. Telomerase activity was determined by telomeric repeat amplification protocol assay, and spliced variants of hTERT were identified by reverse transcription-polymerase chain reaction in 40 colorectal cancer tissue samples. In the lower range of telomerase activity (0-100 units), the percentage of the β variant decreased with the increment in telomerase activity, whereas in the higher range of telomerase activity (>100 units), total hTERT expression level revealed a trend toward increment. There was a positive correlation between the full-length variant level and β variant level. Conversely, there was a negative correlation between the percentage of the full-length variant and β variant. Tumor-node-metastasis stage was the strongest prognostic factor in multivariate analysis and the percentage of the full-length variant was an independent prognostic factor for survival. Telomerase activity was primarily altered with changes in alternative splicing of the full-length and β variants of hTERT in colorectal cancer. [ABSTRACT FROM AUTHOR]

The present study examined differential expression levels of DNA damage repair genes in COLO 205 colorectal cancer cells, with the aim of identifying novel biomarkers for the molecular diagnosis and treatment of colorectal cancer. COLO 205-derived cell spheres were cultured in serum-free medium supplemented with cell factors, and CD133+/CD133- cells were subsequently sorted using an indirect CD133 microbead kit. In vitro differentiation and tumorigenicity assays in BABA/c nude mice were performed to determine whether the CD133+ cells also possessed stem cell characteristics, in addition to the COLO 205 and CD133- cells. RNA sequencing was employed for the analysis of differential gene expression levels at the mRNA level, which was determined using reverse transcription-quantitative polymerase chain reaction. The mRNA expression levels of 43 genes varied in all three types of colon cancer cells (false discovery rate ≤0.05; fold change ≥2). Of these 43 genes, 30 were differentially expressed (8 upregulated and 22 downregulated) in the COLO 205 cells, as compared with the CD133- cells, and 6 genes (all downregulated) were differentially expressed in the COLO 205 cells, as compared with CD133+ cells. A total of 18 genes (10 upregulated and 8 downregulated) were differentially expressed in the CD133- cells, as compared with the CD133+ cells. By contrast, 6 genes were downregulated and none were upregulated in the CD133+ cells compared with the COLO 205 cells. These findings suggest that CD133+ cells may possess the same DNA repair capacity as COLO 205 cells. Heterogeneity in the expression profile of DNA damage repair genes was observed in COLO 205 cells, and COLO 205-derived CD133- cells and CD133+ cells may therefore provide a reference for molecular diagnosis, therapeutic target selection and determination of the treatment and prognosis for colorectal cancer. [ABSTRACT FROM AUTHOR]

Dysregulation of microRNA (miRNA/miR) expression is causally associated with cancer initiation and progression. However, the precise mechanisms by which dysregulated miRNAs induce colorectal tumorigenesis remain unknown. In the present study, downregulation of miR-34a was identified in colorectal cancer cell lines and clinical specimens. Clinical studies revealed that miR-34a expression was negatively associated with distant metastasis, and positively associated with differentiation and survival of human colorectal cancer specimens. In vitro miRNA functional assays demonstrated that miR-34a bound to the putative 3'-untranslated regions of Notch1 and Jagged1 in SW480 cells, and thereby attenuated the migration and invasion of the colon cancer cells. It was additionally identified that miR-34a downregulated the expression of vimentin and fibronectin via Notch1 and Jagged1. Overall, these data indicate that miR-34a serves a key role in suppressing colorectal cancer metastasis by targeting and regulating Notch signaling. [ABSTRACT FROM AUTHOR]

The present study was planned to explore the correlation between the methylation of APC (adenomatous polyposis coli) and colon carcinogenesis. Colon cancer tissues and tumor-adjacent normal tissues of 60 colon cancer patients (who received surgical operation in our hospital from January 2012 to December 2014) were collected. SW1116 cells in human colon cancer tissues were selected for culturing. 5-aza-2c-deoxycytidine (5-aza-dC) was utilized as an inhibitor of the methylation for APC gene. Methylation specific PCR (MSP) was utilized for detection of APC methylation in SW1116 cells. The MTT and Transwell assays were performed to detect the effect of the methylation of APC gene on the proliferation and invasive abilities of SW1116 cells. The correlation between the methylation of APC gene and pathological parameters of colon cancer patients was analyzed. MSP results revealed that 41 cases (68.33%) showed methylation of APC gene in colon cancer tissues. No methylation of APC gene was found in tumor-adjacent normal tissues. 5-aza-dC was able to inhibit the methylation of APC gene in SW1116 cells. APC gene methylation was correlated with tumor size, differentiation degree, lymph node metastasis and Dukes staging. In conclusion, the levels of the methylation of APC in colon cancer tissues and SW1116 cells are relatively high. The methylation of APC promoted the proliferation and invasion abilities of SW1116 cells. Furthermore, methylation is correlated with a variety of clinicopathological features of colon cancer patients. [ABSTRACT FROM AUTHOR]

α-taxilin is a binding partner of syntaxins, which are the central coordinators of membrane traffic. Expression of α-taxilin has been implicated in the development of human glioblastoma, hepatocellular carcinoma and renal cell carcinoma. In the present study, the clinical significance of α-taxilin expression in colorectal cancer (CRC) was investigated. A total of 20 cases of colorectal intramucosal adenocarcinoma (IMA) with adenoma were analyzed using immunohistochemical analysis. The results demonstrated that α-taxilin expression was significantly associated with Ki-67 indices in adenoma and IMA. The patients expressed equally high levels of α-taxilin in the upper third of the intramucosal glands. These results suggest that α-taxilin expression is significantly associated with the proliferative activity of CRC, but that its overexpression alone is not a biomarker of malignancy. Next, α-taxilin expression was investigated in 57 advanced CRCs and its association with prognosis was determined. Well-differentiated and/or moderately differentiated adenocarcinomas in the left-sided colon with anatomic stage II and/or III were analyzed. α-taxilin expression levels were high on the surface of nearly all tumors, but variable at the deep advancing edge. α-taxilin levels at the advancing edge were not significantly associated with local invasiveness or prognosis. In conclusion, α-taxilin is a cell proliferation marker in colorectal epithelial neoplasms but cannot be a marker of malignancy or prognosis of CRCs. [ABSTRACT FROM AUTHOR]

The present study aimed to examine the association of p53 expression levels with clinicopathological features and prognosis of patients with colon cancer following surgery. The present study included 484 patients with colon cancer that underwent colon resection between December 2003 and December 2011. All follow-ups were censored in December 2013 with a median follow-up time of 43 months. Kaplan-Meier survival curves and Cox regression analysis were used to determine predictors for overall survival rate. p53 expression status (positive or negative) was significantly different between patient groups when categorized by age distribution, disease course, tumor location, maximum tumor diameter, depth of tumor invasion, Dukes' stage, distant metastasis and lymph node (LN) metastasis (P<0.05). Cox regression analysis revealed that age, surgery type, histological subtypes, tumor size, tumor location, LN metastasis, distant metastases, Dukes' stage and p53 expression status are independent factors influencing the survival rate of patients with colon cancer following surgery (P<0.05). Therefore, the present study revealed that the loss of p53 expression levels in tumors was associated with aggressive clinicopathological characteristics in patients with colon cancer. [ABSTRACT FROM AUTHOR]

Although Japanese traditional herbal medicine (Kampo) has been widely applied to the treatment of various diseases, including cancer, their mechanisms of action have not yet been elucidated in detail, particularly regarding their role in tumor immunology. The present study investigated the antitumor effects of the Japanese Kampo medicine, ninjin'yoeito (NYT; Ren-Shen-Yang-Rong-Tang in Chinese), which was orally administered with or without an irradiated tumor cell vaccine to a subcutaneous CT26 colon carcinoma tumor model. The irradiated tumor cell vaccine in a prophylactic setting significantly delayed tumor growth in mice fed a control diet, whereas a diet containing NYT alone did not exert any antitumor effects in vivo. However, the inhibition of tumor growth was significantly greater in vaccinated mice fed the NYT diet compared with in vaccinated mice given the control diet. These results suggest that NYT synergistically enhances the effects of the antitumor vaccine. The depletion of cluster of differentiation (CD)8+ T cells abrogated these effects, indicating that antitumor activity required CD8+ T cells. Furthermore, reductions in CD4+ CD25+ and forkhead box protein 3+ T regulatory cell numbers were more apparent between vaccinated mice fed the NYT diet and non-vaccinated mice fed the control diet than between vaccinated mice and non-vaccinated mice fed the control diet, suggesting that the weaker impact of T regulatory cells contributes to the augmentation of antitumor immunity by CD8+ T cells in vaccinated mice fed with NYT. Overall, these results indicate that NYT synergistically enhances the effects of the prophylactic tumor vaccine mediated by CD8+ T cells and that this Japanese Kampo medicine has potential as a useful adjuvant agent for cancer immunotherapy. [ABSTRACT FROM AUTHOR]

Although there is evidence that galectin-9 is a critical factor in health and disease, the upstream regulatory microRNA (miRNA or miR) of the protein remains poorly defined. miR-455-5p is characterized as a tumor-associated miRNA in cancer research. However, the actual role of miR-455-5p with respect to inhibiting or promoting tumorigenesis in colon cancer is unclear. The present study aimed to investigate the expression, role and target regulation association of galectin-9 and miR-455-5p in colon cancer. Western blot analysis and reverse transcription-quantitative polymerase chain reaction were used for the detection of the expression levels of galectin-9 and miRNAs. Cell Counting kit-8 test was used for the evaluation of cell proliferation, while flow cytometry was used for cell apoptosis analysis. A potential interaction between galectin-9 and miR-455-5p was predicted by target prediction programs and confirmed by luciferase assay and transfection with miRNA mimics. The present study revealed that elevated expression of galectin-9 and miR-455-5p in colon cancer was associated with HT29 cell proliferation and apoptosis. Furthermore, the present study demonstrated that miR-455-5p reduced galectin-9 expression by directly targeting its 3'-untranslated region. These data suggest that miR-455-5p functions as a potential oncogene in colon cancer by targeting galectin-9. [ABSTRACT FROM AUTHOR]

Mutations of the tumor protein p53 gene, a tumor suppressor, are one of the most frequent genetic alterations observed in cancer. It has been reported that mutations in p53 result in the loss of wild-type p53 activity, and the gain of novel oncogenic properties that promote tumor growth and progression. Recent studies have demonstrated that a number of microRNAs (miRs) are involved in the post-transcriptional regulation of p53. The present study demonstrates that miR-600 is a direct negative regulator of p53 through binding a site in the 3' untranslated region of p53 mRNA in human colorectal cancer (CRC) cells. Overexpression of miR-600 by lentiviral-mediated transduction decreased endogenous levels of p53 protein and inhibited cell proliferation, migration and invasion in mutant p53-expressing human CRC cell lines (SW480, SW620 and DLD-1) in vitro. In addition, silencing of p53 with small interfering RNA led to a similar phenotype. Furthermore, overexpression of miR-600 or p53 knockdown suppressed the expression of matrix metalloproteinase 9, and promoted the expression of E-cadherin and β-catenin. The results of the current study demonstrate that miR-600 is an important negative regulator of p53, and suggest that targeting mutant p53 using lentiviral-mediated miR-600 overexpression is a promising therapeutic strategy for the treatment of CRCs with p53 mutations. [ABSTRACT FROM AUTHOR]

The expression levels of cyclooxygenase (COX)-2 and the prostaglandin E2 (PGE2) content have been associated with poor prognosis in patients with colorectal cancer (CRC). There is a strong correlation between COX-2 expression and PGE2 production in tissues from CRC patients, suggesting an important role for COX-2 on the regulation of PGE2 production. Previous studies by the present authors, where CRC patients were divided into high- or low-COX-2 expressing tumors, displayed important differences in the expression levels of several transcription factors involved in carcinogenesis. Among them, FBJ murine osteosarcoma viral oncogene homolog B (FosB), which is a member of the activator protein-1 complex, was the highest upregulated transcription factor in patients with high expression levels of COX-2. The present study aimed to investigate the role of FosB on the COX-2/PGE2 axis in CRC cells with high COX-2 expression levels. Interference RNA technology was used to knockdown FosB expression in HCA-7 cells, and 72 h later the messenger (m)RNA expression levels of COX-1 and COX-2, as well as the PGE2 content, were measured. The results indicated that FosB knockdown decreased the expression levels of COX-2 but did not affect the PGE2 content or the mRNA expression levels of COX-1. The present findings suggest an important role for FosB on the regulation of COX-2 expression, but no effect on the regulation of the PGE2 levels. In addition, the present results imply independent regulatory mechanisms for COX-2 expression and PGE2 content. [ABSTRACT FROM AUTHOR]

The endoplasmic reticulum stress inositol‑requiring enzyme (IRE) 1α/X-box binding protein (XBP) 1 signaling pathway is involved in the tumorigenesis of breast and prostate cancer. Mucin 2 (MUC2) protects colon tissues from the formation of tumors. In human colorectal cancer (CRC) the role of IRE1α, and its analogue, IRE1β, has yet to be elucidated. In the present study, the expression levels of IRE1α, IRE1β, un-spliced XBP1u, spliced XBP1s and MUC2 in surgically resected cancerous and adjacent non-cancerous tissues from patients with CRC were investigated. The IRE1α, IRE1β, XBP1u, XBP1s and MUC2 mRNA expression levels were determined using reverse transcription-quantitative polymerase chain reaction, and the protein expression levels were detected using immunohistochemistry and western blotting. The association between the expression levels of IRE1α, IRE1β and MUC2 and the clinicopathological features of patients with CRC was subsequently analyzed. The mRNA expression levels of IRE1β and MUC2 were decreased by ~2.1 and ~4.5-fold in CRC tissues, respectively, as compared with the adjacent normal tissues. The protein expression levels of IRE1β and MUC2 were decreased by ~8.0 and ~2.0-fold in the CRC tissues, respectively. IRE1β mRNA expression levels were positively correlated with MUC2 mRNA expression levels. IRE1β expression levels were revealed to be significantly associated with lymph node metastasis, tumor stage and histological differentiation. However, IRE1α, XBP1u and XBP1s mRNA and IRE1α protein expression levels were not observed to significantly differ between cancerous tissues and the adjacent normal tissues. The results indicated that the expression of IRE1β, but not IRE1α, may protect colon tissue from developing CRC by inducing MUC2 expression. Therefore, decreased IRE1β expression levels may be associated with the development of CRC through the inhibition of MUC2 expression. [ABSTRACT FROM AUTHOR]

Epigenetics encompasses changes in DNA methylation, histone and chromatin structure, and non-coding RNAs, specifically microRNA (miRNA) expression. Recent advances in the rapidly evolving field of colorectal cancer (CRC) epigenetics have revealed a complicated network of reciprocal interconnections between miRNAs and other epigenetic machinery. On the one hand, miRNA expression may be regulated by epigenetic mechanisms including DNA methylation and histone modifications. However, miRNAs may affect the epigenetic machinery by directly targeting its enzymatic components. In this study, we focus on the colorectal miRNA expression profile and further illustrate the reciprocal regulation in CRC, with the aim of offering new insights into the strategies of combatting the disease. [ABSTRACT FROM AUTHOR]

Although the Notch pathway has been reported to be activated in colorectal cancer (CRC), limited information is available regarding the expression and role of its ligand, Jagged 2 (JAG2), in CRC. Using immunohistochemistry, the present study demonstrated that JAG2 protein expression may be detected in up to 95% of CRC cases and is 3-fold upregulated in tumor cells compared to surrounding normal tissues. This finding suggests that JAG2 may have a role in the tumorigenicity of CRC. To further investigate the cellular functions of JAG2 expression in CRC, two different small interfering RNAs (siRNAs) were used to downregulate JAG2 expression in CRC cell lines (HCT116, DLD-1 and HT-29). The results indicated that JAG2 knockdown inhibits the motility and invasiveness of CRC cell lines without significantly affecting cell proliferation. These findings implicate JAG2 in promoting aggressiveness of CRC, and lay the foundation for its future development as a therapeutic target for the treatment of CRC. [ABSTRACT FROM AUTHOR]

Colorectal cancer (CRC) is one of the most common malignancies, and the third leading cause of cancer mortality worldwide. Timely detection of CRC in patients with earlier stages provides the highest rate of survival. Epigenetic alterations are important in the occurrence and progression of CRC, and represent the primary modifications of cancer cells. Therefore, detection of these alterations in CRC cases are thought to hold great promise as diagnostic biomarkers. It has been shown that the SEPT9 and NTRK3 genes are aberrantly methylated and their detection can be used as biomarkers for early diagnosis of CRC. The present study analyzed promoter methylation status of these genes in CRC patients. Genomic DNA was extracted from 45 CRC and paired adjacent healthy tissues and undergone bisulfite conversion, and the methylation status of NTRK3 and SEPT9 were defined using the MS-HRM assay. Our results showed that there are statistically significant differences in methylation status of NTRK3 and specially SEPT9 between CRC and adjacent normal tissues (P<0.001). High sensitivity and specificity for a specific location in SEPT9 gene promoter as a diagnostic biomarker was observed. SEPT9 promoter hypermethylation may serve as a promising biomarker for the detection of CRC development. However, to validate the biomarker potential of NTRK3 there is a requirement for further investigation. [ABSTRACT FROM AUTHOR]

The aim of the present study was to identify potential therapeutic targets for colorectal cancer (CRC). The gene expression profile GSE32323, containing 34 samples, including 17 specimens of CRC tissues and 17 of paired normal tissues from CRC patients, was downloaded from the Gene Expression Omnibus database. Following data preprocessing using the Affy and preprocessCore packages, the differentially-expressed genes (DEGs) between the two types of samples were identified with the Linear Models for Microarray Analysis package. Next, functional and pathway enrichment analysis of the DEGs was performed using the Database for Annotation Visualization and Integrated Discovery. The protein-protein interaction (PPI) network was established using the Search Tool for the Retrieval of Interacting Genes database. Utilizing WebGestalt, the potential microRNAs (miRNAs/miRs) of the DEGs were screened and the integrated miRNA-target network was built. A cohort of 1,347 DEGs was identified, the majority of which were mainly enriched in cell cycle-related biological processes and pathways. Cyclin-dependent kinase 1 (CDK1), cyclin B1 (CCNB1), MAD2 mitotic arrest deficient-like 1 (MAD2L1) and BUB1 mitotic checkpoint serine/threonine kinase B (BUB1B) were prominent in the PPI network, while the over-represented genes in the integrated miRNA-target network were SRY (sex determining region Y)-box 4 (SOX4; targeted by hsa-mir-129), v-myc avian myelocytomatosis viral oncogene homolog (MYC; targeted by hsa-let-7c and hsa-mir-145) and cyclin D1 (CCND1; targeted by hsa-let-7b). CDK1, CCNB1 and CCND1 were also associated with the p53 signaling pathway. Overall, several genes associated with the cell cycle and p53 pathway were identified as biomarkers for CRC. CDK1, CCNB1, MAD2L1, BUB1B, SOX4, collagen type I a2 chain and MYC may play significant roles in CRC progression by affecting the cell cycle-related pathways, while CDK1, CCNB1 and CCND1 may serve as crucial regulators in the p53 signaling pathway. Furthermore, SOX4, MYC and CCND1 may be targets of miR-129, hsa-mir-145 and hsa-let-7c, respectively. However, further validation of these data is required. [ABSTRACT FROM AUTHOR]