Inhibited Colorectal Cancer Cell Proliferation Research Articles

Colorectal Cancer Cells Increase the Production of Short Chain Fatty Acids by Propionibacterium freudenreichii Impacting on Cancer Cells Survival.

Propionibacterium freudenreichii is a commercially relevant bacterium with probiotic potential. This bacterium can exert protective effects particularly against colorectal cancer (CRC), via the production of short chain fatty acids (SCFA), namely acetate and propionate. In this work, we aimed to evaluate the performance and adaptation capacity of P. freudenreichii to a simulated digestive stress using different culture media, namely YEL, Basal medium, Mimicking the Content of the Human Colon medium (MCHC) and DMEM. The effect of the fermented culture broth on CRC cells survival and of CRC cells conditioned media on the bacteria performance was also evaluated. Basal medium was found to be the best for P. freudenreichii to produce SCFA. MCHC medium, despite being the medium in which lower amounts of acetate and propionate were produced, showed higher acetate and propionate yields as compared to other media. We also observed that the presence of lactate in CRC cells conditioned growth medium resulting from cell metabolism, leads to an increased production of SCFA by the bacteria. The bacterial fermented broth successfully inhibited CRC cells proliferation and increased cell death. Our results showed for the first time that P. freudenreichii performance might be stimulated by extracellular lactate produced by CRC metabolic switch also known as “Warburg effect,” where cancer cells “ferment” glucose into lactate. Additionally, our results suggest that P. freudenreichii could be potentially used as a probiotic in CRC prevention at early stages of the carcinogenesis process and might help in CRC therapeutic approaches.

The lncRNA ZEB1-AS1 sponges miR-181a-5p to promote colorectal cancer cell proliferation by regulating Wnt/β-catenin signaling

ABSTRACT Long noncoding RNAs (lncRNAs) are important regulators of the biological functions and underlying molecular mechanisms of colorectal cancer (CRC). However, the role of the lncRNA ZEB1-AS1 in CRC is not thoroughly understood. In this study, we found that ZEB1-AS1 was markedly upregulated in CRC. ZEB1-AS1 knockdown significantly suppressed CRC cell proliferation and induced apoptosis, whereas enhanced expression of ZEB1-AS1 had the opposite effect. Bioinformatics analysis identified miR-181a-5p as a candidate target of ZEB1-AS1. Moreover, we found an inverse correlation between ZEB1-AS1 and miR-181a-5p expression in CRC tissue. Inhibition of miR-181a-5p significantly upregulated ZEB1-AS1, whereas overexpression of miR-181a-5p had the opposite effect, suggesting that ZEB1-AS1 is negatively regulated by miR-181a-5p. Using luciferase reporter and RIP assays, we found that miR-181a-5p directly targets ZEB1-AS1. Importantly, ZEB1-AS1 may act as an endogenous ‘sponge’ to regulate miRNA targets by competing for miR-181a-5p binding. In summary, our findings provide the evidence supporting the role of ZEB1-AS1 as an oncogene in CRC. Our study also demonstrates that miR-181a-5p targets not only protein-coding genes but also the lncRNA ZEB1-AS1.

Toll-like receptor 2 stimulation promotes colorectal cancer cell growth via PI3K/Akt and NF-κB signaling pathways

Toll-like receptor (TLR) 2 is a key regulator of innate immune responses and has been shown to play an important role in inflammation-associated cancers. In this study, we aimed to evaluate the role of TLR2 in colorectal cancer (CRC). We demonstrated that TLR2 mRNA and protein expression was significantly upregulated in tumors from CRC patients and indicated poor prognosis. Using the TLR2 agonist Pam3Cys (P3C) to activate TLR2 signaling in human CRC cell lines, we showed that TLR2 drives cellular proliferation, which was dependent upon PI3K/Akt and NF-κB signaling pathways and was associated with the upregulation of anti-apoptotic genes BCL2A1, WISP1 and BIRC3. Likewise, pharmacological blockade of PI3K/Akt and NF-κB pathways mitigated the CRC pro-survival effects of TLR2 stimulation. Furthermore, genetic ablation of TLR2 using CRISPR/Cas9 suppressed CRC cell proliferation, invasion and migration. Taken together, these findings demonstrate that TLR2 plays an important role in colorectal tumorigenesis and may represent a promising therapeutic target in CRC.

Exome sequencing reveals the genetic landscape and frequent inactivation of PCDHB3 in Chinese rectal cancers.

Colorectal cancer (CRC) is the third most common cancer worldwide, with more than 1.3 million new cases and 690 000 deaths each year. In China, the incidence of CRC has increased dramatically due to dietary and lifestyle changes, to become the fifth leading cause of cancer-related death. Here, we performed whole-exome sequencing in 50 rectal cancer cases among the Chinese population as part of the International Cancer Genome Consortium research project. Frequently mutated genes and enriched pathways were identified. Moreover, a previously unreported gene, PCDHB3, was found frequently mutated in 5.19% cases. Additionally, PCDHB3 expression was found decreased in 81.6% of CRC tissues and all eight CRC cell lines tested. Low expression and cytoplasmic localization of PCDHB3 predict poor prognosis in advanced CRC. Copy number decrease and/or CpG island hypermethylation contributes to the pervasive decreased expression of PCDHB3. PCDHB3 inhibits CRC cell proliferation, migration, and epithelial-mesenchymal transition. The tumor-suppressive effects of PCDHB3 are partially due to inhibition of NF-κB transcriptional activity through K63 deubiquitination of p50 at lysine 244/252, which increases the binding affinity of inactive p50 homodimer to κB DNA, resulting in competitive inhibition of the transcription of NF-κB target genes by p65 dimers. Our study identified PCDHB3 as a novel tumor suppressor in CRC via inhibition of the NF-κB pathway, and its expression and localization may serve as prognostic markers for advanced CRC. Copyright © 2018 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

MiR-760 suppresses human colorectal cancer growth by targeting BATF3/AP-1/cyclinD1 signaling

BackgroundRecent studies have reported that microRNAs (miRNAs) often function as negative post-transcriptional regulators with altered expression levels found in colorectal cancer (CRC). There have been few studies on miRNAs that regulate the oncogenic alterations in CRC. Here, we aim to explore the anti-cancer miRNA and the potential mechanisms by which miRNAs modulate CRC progression.MethodsWe performed an integrated analysis of CRC miRNA expression datasets in The Cancer Genome Atlas (TCGA). The miRNA with the lowest expression, miR-760, was validated in an independent validation sample cohort of 76 CRC tissues. Functional assays, such as CCK-8 assay, colony formation assay, and CFSE staining, were used to determine the oncogenic role of miR-760 in human CRC progression. Furthermore, western blotting and dual-luciferase reporter assay were used to determine the mechanism by which miR-760 promotes proliferation of CRC cells. Xenograft nude mouse models were used to determine the role of miR-760 in CRC tumorigenicity in vivo. Immunohistochemical assays were conducted to study the relationship between miR-760 expression and basic leucine zipper transcriptional factor ATF-like 3 (BATF3) expression in human CRC samples.ResultsmiR-760 was markedly downregulated in CRC tissues, and low miR-760 expression was associated with poor prognosis among CRC patients. Upregulation of miR-760 suppressed CRC cell proliferation, whereas downregulation of miR-760 promoted CRC proliferation in vitro. Additionally, we identified BATF3 as a direct target of miR-760, and that the essential biological function of miR-760 during CRC progression both in vitro and in vivo is to suppress the expression of BATF3 and downstream cyclinD1 via AP-1 transcription factor. Finally, we showed a significant correlation between miR-760 and BATF3 expression in CRC tissues.ConclusionsmiR-760 inhibited CRC growth by downregulating BATF3/AP-1/ cyclinD1 signaling.

PMN inhibits colorectal cancer cells through inducing mitotic arrest and p53-dependent apoptosis via the inhibition of tubulin polymerization

Colorectal cancer (CRC) is the third most prevalent malignancy worldwide. New understandings about this disease are urgently required to guide clinical therapies. In this study, we focused on the effects of the small molecule PMN on CRC cells. PMN dose-dependently inhibited CRC cell proliferation through inducing mitotic arrest and apoptosis. PMN induced mitotic arrest via the disruption of spindle apparatus by inhibiting microtubule polymerization. PMN-induced mitotic arrest resulted in apoptosis and p53 upregulation. Furthermore, p53 upregulation sensitized PMN-induced mitotic cells to apoptosis. This study deepens the understanding of the effects of p53 on the response of CRC cells to PMN, providing the basis for the potential development of PMN as a lead compound of microtubule-destabilizers for p53-positive CRC treatment.

NUSAP1 gene silencing inhibits cell proliferation, migration and invasion through inhibiting DNMT1 gene expression in human colorectal cancer

Colorectal cancer (CRC) is one of the most common cause of cancer-related death in both female and male patients, with a high capacity for tumor migration and invasion. Recently, aberrant nucleolar and spindle-associated protein 1 (NUSAP1) expression has been reported in several cancers. However, the biological function and molecular mechanism of NUSAP1 in CRC have not been reported. Here, we demonstrated that NUSAP1 gene expression was notably upregulated in CRC tissues and cell lines (Caco2, LS174T, SW480, and LoVo). Subsequently, SW480 and LoVo cells were transfected with NUSAP1 siRNA, respectively, and the biological function of NUSAP1 was investigated. Results indicated that NUSAP1 silencing by siRNA inhibited CRC cell proliferation, and induces cell apoptosis. Moreover, NUSAP1 knockdown suppressed cell migration, cell invasion, and epithelial-to-mesenchymal transition (EMT). Furthermore, NUSAP1 silencing notably inhibited the mRNA and protein expression level of DNA methyltransferase 1 (DNMT1). DNMT1 overexpression partly rescued the effect of NUSAP1 silencing on colorectal cancer biological function. Taken together, NUSAP1 gene silencing induced cell apoptosis, and inhibited cell proliferation, cell migration, cell invasion, and EMT in colorectal cancer through inhibiting DNMT1 gene expression. These findings indicat that NUSAP1 is a promising molecular target for CRC treatment.

Nuclear receptor binding protein 1 correlates with better prognosis and induces caspase-dependent intrinsic apoptosis through the JNK signalling pathway in colorectal cancer

Nuclear receptor binding protein 1 (NRBP1) is a ubiquitously expressed and highly conserved pseudokinase that has important roles in cellular homoeostasis. Despite recent advances in understanding the biology of NRBP1, the role of NRBP1 and its underlying mechanism in colorectal cancer (CRC) have not been fully elucidated. In the present study, we observed that NRBP1 expression levels were significantly reduced in CRC tissues compared with corresponding adjacent normal tissues, and high NRBP1 expression correlated with better prognosis in CRC. Overexpression of NRBP1 inhibited CRC cell proliferation and promoted apoptosis in vitro and in vivo. In contrast, knockdown of NRBP1 expression increased cell proliferation and decreased the percentage of apoptotic cells. Moreover, overexpression of NRBP1 activated caspase-dependent intrinsic apoptosis. In addition, we further discovered that NRBP1 regulated the apoptotic pathway through interaction with JNK. Finally, NRBP1 overexpression led to attenuated CRC growth in a xenograft mouse model. Our study illustrates the suppressor role of NRBP1 in CRC and provides a potential therapeutic target.

RETRACTED ARTICLE: CircHIPK3 promotes colorectal cancer growth and metastasis by sponging miR-7

Mounting evidences indicate that circular RNAs (circRNAs) have a vital role in human diseases, especially cancers. More recently, circHIPK3, a particularly abundant circRNA, was proposed to be involved in tumorigenesis. However, its role in colorectal cancer (CRC) has not been explored. In this study, we found circHIPK3 was significantly upregulated in CRC tissues and cell lines, at least in part, due to c-Myb overexpression and positively correlated with metastasis and advanced clinical stage. Moreover, Cox multivariate survival analysis showed that high-level expression of circHIPK3 was an independent prognostic factor of poor overall survival (OS) in CRC (hazard ratio [HR] = 2.75, 95% confidence interval [CI] 1.74–6.51, p = 0.009). Functionally, knockdown of circHIPK3 markedly inhibited CRC cells proliferation, migration, invasion, and induced apoptosis in vitro and suppressed CRC growth and metastasis in vivo. Mechanistically, by using biotinylated-circHIPK3 probe to perform RNA pull-down assay in CRC cells, we identified miR-7 was the only one microRNA that was abundantly pulled down by circHIPK3 in both HCT116 and HT29 cells and these interactions were also confirmed by biotinylated miR-7 pull-down and dual-luciferase reporter assays. Overexpression of miR-7 mimicked the effect of circHIPK3 knockdown on CRC cells proliferation, migration, invasion, and apoptosis. Furthermore, ectopic expression of circHIPK3 effectively reversed miR-7-induced attenuation of malignant phenotypes of CRC cells by increasing the expression levels of miR-7 targeting proto-oncogenes (FAK, IGF1R, EGFR, YY1). Remarkably, the combination of circHIPK3 silencing and miR-7 overexpression gave a better effect on tumor suppression both in vitro and in vivo than did circHIPK3 knockdown or miR-7 overexpression alone. Taken together, our data indicate that circHIPK3 may have considerable potential as a prognostic biomarker in CRC, and support the notion that therapeutic targeting of the c-Myb/circHIPK3/miR-7 axis may be a promising treatment approach for CRC patients.

Platelet‑derived growth factor receptor‑β gene expression relates to recurrence in colorectal cancer.

Platelet‑derived growth factor receptor‑β (PDGFR‑β) in epithelial tumors is mainly expressed by stromal cells. High expression of PDGFR‑β has been related to poor prognosis in several cancers, however its significance in colorectal cancer (CRC) remains unknown. The present study aimed to clarify the prognostic impact of PDGFR‑β in CRC patients. The study included 194 patients who underwent surgery for CRC. PDGFR‑β expression was examined by real‑time reverse transcription‑polymerase chain reaction and immunohistochemistry and the expression levels were correlated with various clinical parameters. The biological significance was evaluated by knockdown experiments in CRC cell lines and the specific PDGFR inhibitor, crenolanib. PDGFR‑β mRNA and protein expression levels were positively correlated with each other. Low PDGFR‑β expression was associated with significantly better disease‑free survival after curative surgical resection, than high PDGFR‑β expression, according to univariate and multivariate analyses. The assessment of PDGFR‑β knockdown in two cell lines revealed that small interfering RNA (siRNA) inhibition resulted in statistically significant reductions in cell growth and invasion. PDGFR inhibitor suppressed CRC cell proliferation in vitro in a dose‑dependent manner. In conclusion, PDGFR‑β expression was a risk factor for recurrence in patients with CRC and PDGFR inhibitor may be a useful therapeutic agent for CRC.

NF-κB-induced WIP1 expression promotes colorectal cancer cell proliferation through mTOR signaling

Colorectal cancer (CRC) is one of the major causes of cancer deaths worldwide. Wild-type p53-induced protein 1 (WIP1) is overexpressed in multiple human cancers and acted as an oncogene. This study was aimed to investigate the effect of WIP1 in colorectal cancer growth and analyzed underlying mechanisms. Herein, we determined WIP1 expression in CRC tissues and cell lines, as well as evaluated its detailed function in CRC cell proliferation. Several factors have been reported to mediate WIP1 effects; herein, we examined the involvement of mTOR and p21 in WIP1 regulation of CRC cell proliferation. Moreover, NF-κB has been regarded as a positive transcriptional regulator of WIP1 to activate its expression. NF-κB knockdown suppressed CRC cell proliferation, which could be reversed by WIP1 overexpression, through p21 and mTOR. Further, we examined the binding of NF-κB to the promoter region of WIP1. In CRC tissues, NF-κB expression was significantly up-regulated, and positively correlated with WIP1 expression, suggesting that inhibiting NF-κB expression to attenuate its activating effect on WIP1 expression presented a promising strategy of controlling excess proliferation of CRC cell. In summary, WIP1 promotes CRC proliferation through p21 and mTOR, both downstream targets of p53; NF-κB served as a positive transcriptional regulator of WIP1 to activate its expression and affect its function in CRC cells. Our finding provided a novel strategy for treatment for CRC.

Hsa_circ_0014717 is downregulated in colorectal cancer and inhibits tumor growth by promoting p16 expression

Circular RNAs (circRNAs) represent a novel class of non-coding RNAs that may regulate gene expression in eukaryotes. Nevertheless, their potential functions in human malignancies are still largely unknown. The aim of this study was to explore the expression of hsa_circ_0014717 in colorectal cancer (CRC) and its role involving in tumor growth. We found that hsa_circ_0014717 was downregulated in CRC tissues and cell lines, and was significantly correlated with TNM stage, distal metastasis and poor overall survival of CRC patients as well. Moreover, our gain-of-function analysis further showed that hsa_circ_0014717 overexpression could significantly suppress CRC cell proliferation and colony formation, as well as induce cell cycle G0/G1 phase arrest in vitro and inhibit xenograft tumor growth in vivo. In addition, hsa_circ_0014717 could upregulate the expression of cell cycle inhibitory protein p16. Besides, p16 knockdown could reverse hsa_circ_0014717 mediated growth inhibition of CRC cells. Taken together, hsa_circ_0014717 acts as a potential tumor suppressor that inhibits CRC growth, partly at least, through upregulating p16 expression. Furthermore, our present study may provide a promising therapeutic target for CRC patients.

Rubus sanctus Schreb. root extract alters the MicroRNA expression and inhibits tumor activities of colorectal cancer cell lines

Background: Colorectal cancer (CRC) is one of the most common cancers in the world. Although surgical and screening techniques have vastly improved in the last 30 years, chemotherapeutics have not advanced sufficiently for successful treatment. Objective: The aim of this study is to investigate the microRNA (miRNA) expression changes and anticancer agent potential of Rubus Sanctus Schreb. root extract (RRE) on LoVo and HT-29 colorectal adenocarcinoma cell lines. Materials and Methods: LoVo and HT-29 CRC cell lines treated with different concentrations of RRE to find growth inhibitory effect with WST-1 assay. Fifty percent growth inhibition and 25% growth inhibition concentrations further evaluated with annexin V, total caspase, cell cycle, and migration assays. Real-time polymerase chain reaction was used to investigate the expression differences in miRNA after extract treatment. Results: Cell proliferation was reduced 77.98% in HT-29 cells after RRE treatment ( P P P P P Conclusion: Our data show for the first time that RRE has the capability to inhibit CRC cell proliferation and invasion and alter epigenetic mechanisms. Although further studies should be conducted on this topic, RRE is thought to be a potential candidate for the future studies regarding new therapy options. Abbreviation used: RRE: Rubus Sanctus Schreb. root extract; CRC: Colorectal cancer; GI 50 , GI 25: 50% and 25% growth inhibition; miRNA: MicroRNA; MGMT: O-6-Methylguanine-DNA methyltransferase; UTR: Untranslated region; Akt: Protein kinase B; PI3K: Phosphoinositide 3-kinase; NF-κB: Nuclear factor kappaB; iNOS: Inducible nitric oxide synthase; COX-2: cyclooxygenase 2; TNFα: tumor necrosis factor alpha; IL-6: Interleukin 6; DMEM: Dulbecco's Modified Eagle's medium; RPMI-1640: Roswell Park Memorial Institute 1640 medium; HPLC: High-performance liquid chromatography; UV-Vis: Ultraviolet-visible; FBS: Fetal bovine serum; OD: Optical density; RFU: Relative fluorescence unit; PE: Phycoerythrin; 7-AAD: 7-Aminoactinomycin D; PBS: Phosphate-buffered saline; EGFR: Epidermal growth factor receptor; 5-FU: Fluorouracil; MSI: Microsatellite instability; NSCLC: Nonsmall cell lung cancer; TGF-β: Transforming growth factor beta; EMT: Epithelial–mesenchymal transition

Long Non-Coding RNA SH3PXD2A-AS1 Promotes Cell Progression Partly Through Epigenetic Silencing P57 and KLF2 in Colorectal Cancer

Background/Aims: Colorectal cancer (CRC) is one of the most commonly diagnosed malignancies worldwide. Current evidence has revealed the key roles of long non-coding RNAs (IncRNAs) in multiple cancers, including CRC. In this study we identified the lncRNA SH3PXD2A-AS1 as a novel molecule associated with CRC progression by analyzing the publicly available data from The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) datasets. Methods: Quantitative real-time polymerase chain reaction (qRT-PCR) assays were performed to examine the expression levels of SH3PXD2A-AS1 in CRC tissue samples and CRC cell lines. Cell viability examination, colony-formation experiments, ethynyl deoxyuridine (Edu) assays and flow cytometry were performed to investigate the roles of SH3PXD2A-AS1 in CRC proliferation, cell cycle regulation, and apoptosis. Transwell assays were used to explore the effects of SH3PXD2A-AS1 on CRC cells migration and invasion. A nude mice model was used to assess the effects of SH3PXD2A-AS1 on tumorigenesis in vivo. Subcellular fractionation, RNA immunoprecipitation (RIP), and chromatin immunoprecipitation (ChIP) assays were conducted to detect the molecular mechanisms of SH3PXD2A-ASl-mediated gene expression. Rescue assays were used to determine whether P57 and Kruppel-like factor 2 (KLF2) were involved in SH3PXD2A-ASl-dependent CRC proliferation. Results: We firstly found that SH3PXD2A-AS1 was significantly upregulated in CRC tissues and cell lines, and overexpression of SH3PXD2A-AS1 was correlated with tumor size, TNM stage, and lymph node metastasis in patients with CRC. Furthermore, SH3PXD2A-AS1 knockdown inhibited CRC cells proliferation, migration and invasion in vitro, and suppressed tumorigenesis in vivo. Mechanistic studies indicated that SH3PXD2A-AS1 could epiqenetically repress P57 and KLF2 expression through interaction with EZH2. Rescue experiments suggested that SH3PXD2A-ASl-mediated oncogenesis was impaired by overexpression of P57 or KLF2. Interestingly, the expression of SH3PXD2A-AS1 was inversely correlated with the expression of P57 and KLF2 in CRC tissue samples. Conclusion: Our research presents the first evidence that SH3PXD2A-AS1 acts as an oncogene in CRC, and may be a promising diagnostic or therapeutic target in patients with CRC.

Knockdown of GRHL3 inhibits activities and induces cell cycle arrest and apoptosis of human colorectal cancer cells.

The Grainyhead-like 3 (GRHL3) is involved in epidermal barrier formation, neural tube closure and wound repair. Previous studies have suggested that GRHL3 has been linked to many different types of cancers. However, to date, its effects on human colorectal cancer (CRC) has not been clarified yet. Our microarray analysis has indicated predominant GRHL3 expression in CRC. The purpose of this study was to investigate the expression and significance of GRHL3 in CRC tumorigenesis using CRC tissues and paired paracancerous tissues, as well as using distinct CRC cell lines (HT29 and DLD1). We observed increased GRHL3 expression at both mRNA and protein levels in CRC tissues and CRC cell lines using quantitative real-time polymerase chain reaction (qRT-PCR) and Western blotting. Moreover, silencing GRHL3 with siRNA could suppress CRC cell proliferation, viability and migration in vitro. We also found that knockdown of GRHL3 could promote cell cycle arrest at G0/G1 phase in HT29 cells and DLD1 cells, and induce cell apoptosis in HT29 cells. Together, our study revealed the down-regulation of GRHL3 in vitro could inhibit CRC cell activity and trigger cell cycle arrest at G0/G1 phase and apoptosis.

MiRNA-495 suppresses proliferation and migration of colorectal cancer cells by targeting FAM83D

microRNAs (miRNAs) have been reported to play crucial roles in malignant tumor progression, including cell development, proliferation, and progression. Increasing evidence suggests that miR-495 functions as either an oncogene or tumor suppressor in several tumor types. However, its biological role in the development of colorectal cancer (CRC) still remains unclear. In this study, we found that miR-495 expression level was remarkably down-regulated in CRC tissues samples and cell lines when compared to adjacent normal tissues and cell line by using qRT-PCR detection. Ectopic expression of miR-495 by mimic transfection significantly suppressed CRC cell proliferation and colony formation, inhibited migration and invasion, and induced apoptosis according to CCK-8, colony formation, transwell, and flow cytometry assays. Furthermore, bioinformatics and luciferase reporter assays verified that family with sequence similarity 83, member D (FAM83D) was a direct target of miR-495 in CRC cells, and FAM83D was confirmed to be upregulated in human CRC tissues and reversely correlated with miR-495 expression. In addition, rescue experiments revealed that restoration of FAM84D could partially abrogate the inhibitory effect of miR-495 overexpression on CRC cell proliferation and metastasis. Further mechanic investigations also verified that the PTEN/P13K/AKT/mTOR pathway was involved in the miR-495/FAM83D-mediated CRC cell progression. Our findings identified that miR-495 acted as a critical tumor suppressor by directly targeting FAM83D during CRC development and therefore represented as a potential biomarker for CRC therapy.

SHP2 associates with nuclear localization of STAT3: significance in progression and prognosis of colorectal cancer

Tyrosine phosphatase SHP2, encoded by PTPN11, has been implicated in many physiologic and pathologic processes in neoplastic progression. However, controversies are emerging from many studies, indicating SHP2 has a dual role in different types of tumors. We aimed to explore the role of SHP2 in progression and prognosis of colorectal cancer (CRC). SHP2 inhibited CRC cell proliferation and migration, and the phosphorylation of STAT3 was negatively regulated by SHP2 in CRC. SHP2 and nuclear STAT3 were examined in 270 CRC tissues. SHP2 was significantly correlated with nuclear STAT3 (Spearman’s rho = −0.408, P ≤ 0.001). Based on Cox regression analysis, patients with high levels of SHP2 and low levels of nuclear STAT3 had longer disease-specific survival (DSS) (HR, 0.362; 95% CI, 0.165–0.794) and disease-free survival (DFS) (HR, 0.447; 95% CI, 0.227–0.877). Further, low levels of SHP2 and high levels of nuclear STAT3 were independently associated with adverse outcomes in the whole cohort (DFS; HR, 2.353; 95% CI, 1.199–4.619). These results suggest that combination of SHP2 and nuclear STAT3 is a strong prognostic predictor in CRC.

Long Noncoding RNA HEIH Promotes Colorectal Cancer Tumorigenesis via Counteracting miR-939‒Mediated Transcriptional Repression of Bcl-xL.

PurposeStudies have found that long noncoding RNA HEIH (lncRNA-HEIH) is upregulated and facilitates hepatocellular carcinoma tumor growth. However, its clinical significances, roles, and action mechanism in colorectal cancer (CRC) remains unidentified.Materials and MethodslncRNA-HEIH expression in CRC tissues and cell lines was measured by quantitative real-time polymerase chain reaction. Cell CountingKit-8, ethynyl deoxyuridine incorporation assay, terminal deoxynucleotidyl transferase dUTP nick end labeling staining, and nude mice xenografts assays were performed to investigate the roles of lncRNA-HEIH. RNA pull-down, RNA immunoprecipitation, chromatin immunoprecipitation, and luciferase reporter assays were performed to investigate the action mechanisms of lncRNA-HEIH.ResultsIn this study, we found that lncRNA-HEIH is significantly increased in CRC tissues and cell lines. lncRNA-HEIH expression is positively associated with tumor size, invasion depth, and poor prognosis of CRC patients. Enhanced expression of lncRNA-HEIH promotes CRC cell proliferation and decreases apoptosis in vitro, and promotes CRC tumor growth in vivo. Whereas knockdown of lncRNA-HEIH inhibits CRC cell proliferation and induces apoptosis in vitro, and suppresses CRC tumor growth in vivo. Mechanistically, lncRNA-HEIH physically binds to miR-939. The interaction between lncRNA-HEIH and miR-939 damages the binding between miR-939 and nuclear factor κB (NF-κB), increases the binding of NF-κB to Bcl-xL promoter, and promotes the transcription and expression of Bcl-xL. Moreover, Bcl-xL expression is positively associatedwith lncRNA-HEIH in CRC tissues. Blocking the interaction between lncRNA-HEIH and miR-939 abolishes the effects of lncRNA-HEIH on CRC tumorigenesis.ConclusionThis study demonstrated that lncRNA-HEIH promotes CRC tumorigenesis through counteracting miR-939‒mediated transcriptional repression of Bcl-xL, and suggested that lncRNA-HEIH may serve as a prognostic biomarker and therapeutic target for CRC.

MiR-422a inhibits cell proliferation in colorectal cancer by targeting AKT1 and MAPK1

BackgroundmiRNAs are regarded as molecular biomarkers and therapeutic targets for colorectal cancer (CRC), a series of miRNAs have been proven to involve into CRC carcinogenesis, invasion and metastasis. Aberrant miR-422a expression and its roles have been reported in some cancers. However, the function and underlying mechanism of miR-422a in the progression of CRC remain largely unknown.MethodsReal-time PCR were used to quantify miR-422a expression in CRC tissues. Both vivo and vitro functional assays showed miR-422a inhibits CRC cell proliferation. Target prediction program (miRBase) and luciferase reporter assays were conducted to confirm the target genes AKT1 and MAPK1 of miR-422a. Specimens from 50 patients with CRC were analyzed for the correlation between the expression of miR-422a and the expression of the target genes AKT1 and MAPK1 by real-time PCR.ResultsMiR-422a was down‑regulated in CRC tissues and cell lines. Ectopic expression of miR-422a inhibited cell proliferation and tumor growth ability; inhibition of endogenous miR-422a, by contrast, promoted cell proliferation and tumor growth ability of CRC cells. MiR-422a directly targets 3′-UTR of the AKT1 and MAPK1, down-regulation of miR-422a led to the activation of Raf/MEK/ERK and PI3K/AKT signaling pathways to promote cell proliferation in CRC. In addition, miR-422a expression was negatively correlated with the expressions of AKT1 and MAPK1 in CRC tissues.ConclusionmiR-422a inhibits cell proliferation in colorectal cancer by targeting AKT1 and MAPK1.

MicroRNA‑760 inhibits cell proliferation and invasion of colorectal cancer by targeting the SP1‑mediated PTEN/AKT signalling pathway.

Colorectal cancer (CRC), one of the most commonly diagnosed types of cancer worldwide, is the third most prevalent and fourth most frequent cause of cancer‑related mortality. Dysregulated microRNAs (miRNAs) have potential regulatory roles in the development and progression of various cancer types. Therefore, the investigation of the miRNAs involved in CRC formation and progression may lead to the development of highly effective therapeutic strategies for CRC. In the present study, miRNA‑760 (miR‑760) was frequently downregulated in CRC tissues and cell lines. The low levels of miR‑760 expression were significantly correlated with the tumor size, lymph node metastasis and TNM stage of CRC. Functional assays revealed that restoring miR‑760 expression inhibited CRC cell proliferation and invasion invitro. The results of bioinformatics analysis, luciferase reporter assay, reverse transcription‑quantitative polymerase chain reaction and western blot analysis suggested that specificity protein1 (SP1) is a direct target of miR‑760 in CRC. The high expression of SP1 in CRC tissues was inversely correlated with the expression of miR‑760. Rescue experiments demonstrated that enforced SP1 expression rescued the tumor‑suppressing effects of miR‑760 on CRC cell proliferation and invasion. In addition, miR‑760 overexpression is involved in the regulation of the PTEN/AKT signalling pathway. Collectively, the present data demonstrated that miR‑760 directly targets SP1 to inactivate the PTEN/AKT signalling pathway, thus implicating miR‑760 in the regulation of CRC cell proliferation and invasion. Therefore, miR‑760 may be a novel biomarker and therapeutic target for CRC.