Colon Cancer Proliferation Research Articles

635P - Long noncoding RNA CASC21 promotes cell proliferation and metastasis in colon cancer

BackgroundThere is increasing evidence that long non-coding RNAs (lncRNAs) are involved in tumor biology and development. The chromosome 8q24.21 locus is one of the most frequently amplified genomic regions in colon cancer, and many cancer-associated lncRNAs have been found in this 8q24 region. In this study, CASC21, located at 8q24.21, was selected to further experiments in colon cancer. MethodsFirst, we downloaded RNA-sequencing data from the Cancer Genome Atlas (TCGA) database and analyzed the lncRNA expression profile in colon cancer. Then, CASC21, a lncRNA located at 8q24.21,was selected for further experiments. We performed qRT-PCR to detect the expression of CASC21 in colon cancer tissues and cell lines. Fluorescence in situ hybridization (FISH) assay was used to analyze the location of CASC21 in cells. Loss of function assays were used to test the efficacy of CASC21 on proliferation and invasion in colon cancer. Animal experiments including tumorigenicity studies and in vivo metastasis assays were used to determine the roles of CASC21 in tumor growth and metastasis in vivo. ResultsWe found that CASC21 was significantly upregulated in colon cancer tissues compared with corresponding normal tissues. Up-regulation of CASC21 was associated with the tumor -node -metastasis (TNM) stage in colon cancer. Similarly, CASC21 was upregulated in colon cancer cell lines compared with colon epithelial cell line. FISH testing showed that CASC21 mainly located in the cytoplasm rather than the nucleus. Loss of function assays revealed that CASC21 knockdown significantly inhibited cell growth by inducing cell apoptosis and cell cycle arrest. Additionally, CASC21 knockdown promoted cell metastasis by facilitating epithelial mesenchymal transformation (EMT). Moreover, CASC21 expression was significant positively associated with MYC expression in both TCGA data and our cohort. Western blot assays showed that knockdown of CASC21 markedly reduced the expression levels of WNT targets including c-myc, β-catenin and cyclinD1. Animal studies also demonstrated that CASC21 promoted tumor growth and metastasis in colon cancer. ConclusionsOur results provide the first evidence that CASC21 is a novel oncogenic regulator and a potential therapeutic target in colon cancer. Legal entity responsible for the studyXiaoping Qian. FundingHas not received any funding. DisclosureAll authors have declared no conflicts of interest.

Fibroblast-derived CXCL12 regulates PTEN expression and is associated with the proliferation and invasion of colon cancer cells via PI3k/Akt signaling

BackgroundStromal-derived CXCL12 play an important role which influence the proliferation and invasiveness of colon cancer in microenvironment. The present study aimed to analyze the underlying mechanism by which CXCL12 and tumour suppressor protein phosphatase and tensin homologue deleted on chromosome 10 (PTEN) influences the metastatic potential of colon cancer and internal relation of colon cancer and stromal cells.MethodsRT-PCR and western blot were detected the expression of CXCL12, CXCR4 and PTEN in colon cancer cells and stromal cells. The co-operative effects of CXCL12 and PTEN on proliferation and invasion of colon cancer cells were evaluated by real-time PCR, proliferation and invasion assays using an in vitro system consisting of co-cultured cancer cells and stromal cells. We eventually investigated activation of PI3K/Akt signaling by CXCL12 regulate PTEN and involved in the metastatic process of colon cancer. In addition, we also examine how the knockdown of PTEN influences proliferation and invasion and correlate with CXCL12/CXCR4/PI3K/Akt, determination of PTEN up-down-stream targets that preferentially contribute to tumorigenesis.ResultsBlockage of PTEN phosphorylation led to a stronger enhancement of cell proliferation and invasion upon stimulation with CXCL12 via its activation of the PI3K/Akt signaling pathway. Furthermore, knockdown of PTEN by siRNA transfection was also found to enhance the activation of the PI3K/Akt pathway, thereby promoting cell invasion and proliferation. CXCL12 induced transcriptional down-regulation of activated PTEN and this signaling pathway promotes cell survival. CXCL12/CXCR4/PI3K/Akt cascade may be critical for colon cancer cells to metastasize.ConclusionsBased on our results, we suggest that the modification of CXCR4, PTEN, or PI3K function might be promising new therapeutic approaches to inhibit the aggressive spread of colon cancer.

Overexpression LINC01082 suppresses the proliferation, migration and invasion of colon cancer.

Long non-coding RNAs (lncRNAs) are emerging as pivotal regulators in human cancer. LINC01082 was expressed as decreased in colon cancer by previous lncRNA-seq result and TCGA database, however, the role and function of LINC0182 is not clear in colon cancer. Here, we aimed to explore the roleof LINC01082 in colon cancer for exploring the etiopathogenesis of colon cancer. RT-qPCR for LINC01082 expression in tissues (colon cancer vs. their matched adjacent non-cancerous tissues, ANT, n = 39) and cells (colon cancer cells vs. normal colon cells, n = 4) were performed. CCK-8 assay for proliferation of colon cancer, Transwell assay for migration and invasion were carried out in sw480 and sw620 cells. The results revealed that LINC01082 was significantly decreased in tissues and cell lines of colon cancer. Overexpressed LINC01082 significantly suppressed the proliferation ability of colon cancer cells. The migration and invasion of colon cancer cells were also suppressed after LINC01082 overexpression. These findings demonstrated that LINC01082 may act in suppressing the incidence and development of colon cancer via suppressing cell proliferation, migration and invasion, indicating that LINC01082 may act as a new tumor suppressor and may be a promising therapy target for colon cancer.

Small interfering RNA targeting paul-like kinase 1 gene silencing inhibits colon cancer invasion and proliferation in clinical, cellular and mouse studies

Objective To investigate the clinical, cellular and mouse studies of small interfering RNA (siRNA) targeting silencing of paul-like kinase 1 (PLK1) on colon cancer invasion and proliferation. Methods Sixty-eight patients with colon cancer admitted to the Second Affiliated Hospital of Hainan Medical College from July 2013 to September 2018 were enrolled, including 40 males and 28 females. The average age was (47.5±6.2) years. Western blotting and real-time quantitative PCR (RT-qPCR) were used to detect PLK1 protein and mRNA levels, respectively. In vitro invasion assay (Transwell) and cell proliferation and toxicity (CCK-8) assays detect cell invasion and proliferation. A subcutaneous xenograft nude mouse colon cancer model was constructed for animal experiments. The F-test was used to compare the measurement data among groups, and the t-test was used for the comparison between the two groups. The rate was compared using the χ2 test. Correlation analysis was performed using the Spearman method. Results Compared with adjacent tissues (8.72±2.19), the mRNA level of PLK1 in colon cancer tissues (15.34±3.86) was significantly increased (t=12.593, P<0.05). The level of PLK1 was positively correlated with tumor invasion depth (r=0.368, P<0.05) and TNM stage (r=0.403, P<0.05). Compared with the siRNA negative control [invasion: (37.20±4.50)], the invasive ability of SW480 cells was significantly decreased after PLK1-siRNA-1 [invasion: (15.00±3.75)] and PLK1-siRNA-2 [invasion: (14.60±3.40)] treatments (t=5.073, t=4.985, P<0.05). At 24 h, 48 h, and 72 h, compared to the siRNA negative control [absorbance (A) values: 0.53±0.12, 0.73±0.16, 0.86±0.18], the proliferation of PLK1-siRNA-1 (0.32±0.10, 0.40±0.08, 0.53±0.10) and PLK1-siRNA-2 (0.34±0.08, 0.41±0.09, 0.54±0.11) decreased significantly (t=4.167, t=4.990, t=4.833, t=4.001, t=4.708, t=4.665, P<0.05). Compared with the siRNA negative control [tumor volume: (849.12±65.37) mm3; number of nodules: (9.35±2.15)], the mean tumor volume and the number of tumor nodules in nude mice treated with PLK1-siRNA-1 [tumor volume: (135.06±9.11) mm3; number of nodules: 1.46±0.20] and PLK1-siRNA-2 [tumor volume: (127.45±8.86) mm3; number of nodules: (1.30±0.15)] were significantly lower (t=19.168, t=7.004, t=20.365, t=7.659, P<0.05). Conclusion Targeted silencing of PLK1 can inhibit the invasion and proliferation of colon cancer, and provide a theoretical basis for the targeted prevention and treatment of colon cancer. Key words: Colon cancer; Paul-like kinase 1; Invasion; Proliferation

CRISPR-Cas9 mediated CD133 knockout inhibits colon cancer invasion through reduced epithelial-mesenchymal transition.

We previously reported that CD133, as a putative cancer stem cell marker, plays an important role in cell proliferation and invasion in colon cancer. To understand the role of CD133 expression in colon cancer, we evaluated the inhibitory effect of CD133 in colon cancer cells. In this study, we generated CD133knockout colon cancer cells (LoVo) using the CRISPR-Cas9 gene editing system. CD133+ colon cancer cells (LoVo) were infected with the lentiviral vector carrying CD133 gRNA and purified cell by culturing single cell colonies. CD133knockout cells was validated by western blot and flow cytometry analysis. In functional study, we observed a significant reduction in cell proliferation and colony formation in CRISPR-Cas9 mediated CD133 knockout cells in compare with control (P < 0.001). We also found the anticancer effect of stattic was dependent on CD133 expression in colon cancer cells. Although CD133knockout cells could not completely block the tumorigenic property, they showed remarkable inhibitory effects on the ability of cell migration and invasion (P < 0.001). In addition, we examined the epithelial mesenchymal transition (EMT)-related protein expression by western blot. The result clearly showed a loss of vimentin expression in CD133knockout cells. Therefore, CRISPR-Cas9 mediated CD133knockout can be an effective treatment modality for CD133+ colon cancer through reducing the characteristics of cancer stem cells.

Increased glucocorticoid receptor activity and proliferation in metastatic colon cancer

Metastasis is regarded as the fatal hallmark for colon cancer, but molecular mechanisms responsible for it have remained poorly defined. Glucocorticoid receptor (GR) within the tumor microenvironment mediates the effects of stress hormones which are used in clinics for their inflammation-modulatory and immunosuppressive properties. Further, epigenetic activation of GR promotes tumor heterogeneity and metastasis. Here, we sought to investigate the correlation between GR activation and proliferation and invasion in metastatic colon cancer microenvironment. We used proliferation/invasion assays, western blot, RT-qPCR, immunofluorescence staining and quantitative methylation to study glucocorticoid-GR signaling, including the involvement of CDK1, in human colon adenocarcinoma cell lines HT29 and T84 (a representative metastatic cell line). Nuclear expression levels of GR were significantly upregulated in metastatic T84 cells, and glucocorticoid derivative, dexamethasone (DEX) treatment caused increased proliferation and invasion in T84 cell, compared to HT29 cell. DEX treatment induced CDK1 expression which was accompanied by reduced CDK1 methylation, indicating epigenetic regulation. Depletion of GR suppressed proliferation of metastatic colon carcinoma cells and depletion of CDK1 had similar suppressing effects on proliferation as well as invasion of metastatic cells. Our study suggests that glucocorticoid-GR-CDK1 signaling induces proliferation and invasion of colon cancer cells and therapies involving the use of glucocorticoids need to exercise caution and re-evaluation.

Downregulated miR-585-3p promotes cell growth and proliferation in colon cancer by upregulating PSME3.

BackgroundUpregulation of PSME3 and its oncogenic roles have been reported in colon cancer recently. However, the underlying mechanism of PSME3 upregulation remains unknown. Here, we explored the expression of PSME3 and subsequently uncovered its mechanism in colon cancer.Materials and methodsThe expression of PSME3 was analyzed by using online databases, Oncomine and UALCAN. qPCR was carried out to detect the expression of PSME3 in collected colon cancer tissues and cell lines. Moreover, the promoter methylation and the hnRNA level of PSME3 were also analyzed by online database and qPCR, respectively. The candidate miRNAs targeting PSME3 were predicted by Starbase 3.0 and validated by luciferase reporter system. CCK-8, plate colon formation, and Edu incorporation were applied to study the functions of miRNA in colon cancer. The expression of miRNA and its correlation with PSME3 were detected in colon cancer tissues.ResultsOncomine and UALCAN data indicate PSME3 is obviously upregulated in colon cancer tissue samples which is further confirmed in collected colon cancer tissues and cells by qPCR. No significant difference in methylation status promoter of PSME3 was observed between colon and colon cancer tissues. The hnRNA level of PSME3 was comparable between colon epithelial cell and colon cancer cells. miR-585-3p is predicted to directly target PSME3 and is validated by luciferase reporter assay. Then, miR-585-3p downregulation is confirmed and miR-585-3p restoration can suppress cell growth and proliferation by inhibiting PSME3 in colon cancer indicating by CCK-8, plate colon formation, and Edu incorporation. Moreover, negative correlation in expression between miR-585-3p and PSME3 was observed in our collected tissues samples.ConclusionWe reveal for the first time that miR-585-3p downregulation accounts for the overexpression of PSME3 in colon cancer. Moreover, miR-585-3p, serving as a tumor suppressor, can inhibit cell growth and proliferation in colon cancer by targeting PSME3.

Overexpression of miR-671-5p indicates a poor prognosis in colon cancer and accelerates proliferation, migration, and invasion of colon cancer cells.

PurposeColon cancer is one of the common malignancies worldwide, and many genes, including microRNAs (miRNAs), have been demonstrated that associated with progression of various diseases, including cancers. The aim of this study is to investigate the potential role of miR-671-5p in colon cancer.Patients and methodsReverse transcription-quantitative polymerase chain reaction (qRT-PCR) was performed to detect the expression levels of miR-671-5p in 115 paired colon cancer tissues and adjacent normal tissues, as well as in colon cancer cells. Kaplan-Meier curve and Cox regression analyses were used to estimate the prognostic significance of miR-671-5p in colon cancer. CCK-8 assay, colony-formation assay, Transwell migration and invasion assays were used to evaluate the effects of miR-671-5p on cell proliferation, migration, and invasion in colon cancer.ResultsWe found that miR-671-5p expression was increased in colon cancer tissues and cell lines. Overexpression of miR-671-5p was found associated with lymph node metastasis, TNM stage, and poor overall survival of patients with colon cancer. By exploiting miR-671-5p mimics and inhibitors, miR-671-5p overexpression significantly increased cell proliferation, migration, and invasion, while downregulation of miR-671-5p inhibited proliferation, migration, and invasion of colon cancer cells.ConclusionTaken together, miR-671-5p may act as an oncogene in colon cancer and promote proliferation, migration, and invasion of colon cancer cells by targeting TRIM67. And it may be a promising prognostic biomarker and therapeutic application for colon cancer treatment.

Epithelial-mesenchymal transition induced by MyoD inhibits growth of high metastatic colorectal cancer

ObjectivesThe study aimed to investigate the tumor-suppressing factor myogenicity differentiation factor (MyoD) against high metastatic colorectal cancer through its powerful transformation by which the tumor cells were converted into muscle cells or other cells to inhibit the malignant proliferation of tumor cells. MethodsThe roles of MyoD in colon cancer proliferation, invasion and migration were analyzed by CCK-8 assay and Transwell, and EMT by real-time PCR and Western blot. The secretion of TGFβ1 was assayed by ELISA and activation of p-Smad2/3 were assayed by western blot. The effects of MyoD on intestinal cancer growth and EMT in vivo were also analyzed. ResultsWe found MyoD inhibited the proliferation, invasion and migration of colon cancer cell. Moreover, MyoD inhibited the expression of E-cadherin and promoted the expression of vimentin and α-SMA. The secretion of TGFβ1 increased and p-Smad2/3 was activated after MyoD expression. MyoD also inhibits intestinal cancer growth and promoted EMT in vivo. ConclusionOur findings indicate that MyoD inhibited cancer progression and metastasis by promoting EMT through TGF-β1/Smad2/3 activation, which provide new support for MyoD maybe as a novel anti-cancer method for the treatment of colon cancer in the future.

PB2194 DE‐REGULATION OF MIRNAS DURING TREATMENT OF PATIENTS AFFECTED BY MYELOFIBROSIS WITH RUXOLITINIB

Background:MicroRNAs (miRNAs) are a family of small non coding RNAsthathave been associated with control of cell cycle, signal transduction, and many other cell functions in several hematological diseases. In myelofibrosis (MF), it has been reported that 48 miRNAs were expressed in a different way in respect of healthy donors, with particular relevance attributed to miR‐127, miR‐140 and miR‐345 [Liu Y, 2017]. Moreover, hyper‐expression of miR‐494, silencing SOCS6, might contribute to the megakaryocyte hyperplasia commonly observed in MF, thus sustaining a pathogenetic role for these small RNAs [Rontauroli S, 2017]. Nevertheless, it is not yet clear what kind of modulation of miRNAs can occur during treatment with ruxolitinib.Aims:The aim of the present study was to identify eventual changes of miRNAs expression during ruxolitinib therapy in order to try to better understand the action mechanism of this JAK2 inhibitor.MethodsmiRNAs were extracted from bone marrow and peripheral blood samples harvested in 4 patients with MF before starting ruxolitinib and after 3 months of therapy. As controls, 15 peripheral blood samples from healthy subjects and one sample from a bone marrow donor were employed. The expression of 675 miRNAs was assessed by the TaqMan®Low Density Arrays kit (ThermoFisher) and miRGator software was used to identify the respective target genes.Results:No differences in terms of miRNAs expression levels were observed between bone marrow and peripheral blood of MF cases, nor between patients and controls. After 3 months of ruxolitinib, 9 miRNAs resulted significantly up‐regulated: miR‐25, miR‐145, miR‐186, miR‐142‐3b, let‐7b, miR‐30d, miR‐188, miR‐942, and miR‐378. Interestingly, among targets genes of these miRNAs, there are JAK2, MPL, TET2, ASXL1, CBL, IDH1, IDH2, IKZF1, EZH2, genes that are either responsible for MF pathogenesis or prognostic in terms of long‐term outcome. Interestingly, miRNA‐145 has been previously reported to be up‐regulated in PV, and let‐7b is inversely correlated with JAK2V617F mutation in MPN [Bruchova H, 2008]. In our series of 20 patients treated by ruxolitinib we did not observe a significant modulation of JAK2 mutational load, but the interaction between let‐7b and JAK2 could be an interesting issue. Moreover, miR‐188 has been reported to suppress macrophage oxidation and plasma expression of pro‐inflammatory factors [Zhang XF, 2018], that could explain the anti‐inflammatory action of ruxolitinib observed in vivo, with a significant improvement of quality of life of MF patients during treatment. This anti‐inflammatory effect could be also sustained by the miR‐186, that has been reported to inhibit HIF‐1alpha factor, involved in the inflammatory processes [Gardner PJ, 2017], and by the up‐regulation of miR‐145, that seems to inhibit TGFBR2 and reduce sepsis in a murine model [Ma F, 2019]. Moreover, the over‐expression of miR‐30d has been associated with a reduced proliferation in colon cancer [Muhammad S, 2019], and miR‐142 high levels play an anti‐oncogenic activity in breast cancer [Mansoori B, 2019]. If it would be true also in MF, we could argue that ruxolitinib could also exert an anti‐proliferative effect.Summary/Conclusion:Even if only preliminary and on a very small number of cases, this study supports the possible role of miRNAs in the modulating the expression of genes involved in pathogenesis and progression of MF during treatment with ruxolitinib. This could help to better understand the action mechanisms of this important drug.

Naringenin-loaded nano-structured lipid carrier fortifies oxaliplatin-dependent apoptosis in HT-29 cell line

Abstract In the present study, we inspected the role of naringenin-loaded nanostructured lipid carriers (NLCs) in the induction of apoptosis in (HT-29) colon cancer cell in co-administration with oxaliplatin. The cytotoxicity behavior of nanoparticles was investigated by MTT assay and DAPI staining. To understand the molecular mechanism of formulation in induction program cell death, flow cytometric and Real-Time RT-PCR assays were applied. New formulation revealed a mean particle size of 98 ± 3 nm with homogenous dispersity, which was confirmed by SEM graphs. Naringenin and Oxaliplatin-induced cell death in HT-29 colon cancer by IC50 value of 150 ± 11.04 μM and 20 ± 2.25 μM, respectively. Loading Naringenin into new formulation declined the proportion of cell proliferation of HT-29 colon cancer from 47 ± 9.1% to 27 ± 5.3% (p

Inhibitory effects of petasin on human colon carcinoma cells mediated by inactivation of Akt/mTOR pathway.

Background:Colorectal cancer is the third most common cancer worldwide and still lack of effective therapy so far. Petasin, a natural product found in plants of the genus Petasites, has been reported to possess anticancer activity. The present study aimed to investigate the anticolon cancer activity of petasin both in vitro and in vivo. The molecular mechanism of petasin was also further explored.Methods:Caco-2, LoVo, SW-620, and HT-29 cell lines were used to detect the inhibitory effect of petasin on colon cancer proliferation. Cell viability was determined using the MTT (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide) assay. Cell apoptosis was analyzed by flow cytometry. Hoechst 33258 staining was used to visualize morphological changes. Cell migration was assessed using a wound-healing migration assay, and cell invasion was investigated using Transwell chambers. Western blotting assays were employed to evaluate the expression levels of proteins in the protein kinase B/mammalian target of rapamycin (Akt/mTOR) signaling pathway. Finally, in vivo activity of petasin was evaluated using the SW-620 subcutaneous tumor model established in Balb/c nude mice. Twelve rats were randomly divided into control group and 10 mg/kg petasin group. The tumor volume was calculated every 7 days for 28 days. Terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) assay was performed to assess the apoptotic effect of petasin. Differences between two groups were assessed by analysis of independent-sample t tests.Results:Petasin significantly inhibited the proliferation of human colon carcinoma cell lines, induced apoptosis, and suppressed migration and invasion in SW-620 cells. Western blotting results showed that petasin decreased the phosphorylation of Akt (1.01 ± 0.16 vs. 0.74 ± 0.06, P = 0.042), mTOR (0.71 ± 0.12 vs. 0.32 ± 0.11, P = 0.013), and P70S6K (1.23 ± 0.21 vs. 0.85 ± 0.14, P = 0.008), elevated the expression of caspase-3 (0.41 ± 0.09 vs. 0.74 ± 0.12, P = 0.018) and caspase-9 (1.10 ± 0.27 vs. 1.98 ± 0.22, P = 0.009), decreased the Bcl-2 protein (2.75 ± 0.47 vs. 1.51 ± 0.36, P = 0.008), downregulated the expression of matrix metalloproteinase (MMP)-3 (1.51 ± 0.31 vs. 0.82 ± 0.11, P = 0.021) and MMP-9 (1.56 ± 0.32 vs. 0.94 ± 0.15, P = 0.039) in SW-620 cell. In vivo, 10 mg/kg petasin inhibited tumor growth in Balb/c nude mice (924.18 ± 101.23 vs. 577.67 ± 75.12 mm3 at day 28, P = 0.001) and induced apoptosis (3.6 ± 0.7% vs. 36.0 ± 4.9%, P = 0.001) in tumor tissues.Conclusions:Petasin inhibits the proliferation of colon cancer SW-620 cells via inactivating the Akt/mTOR pathway. Our findings suggest petasin as a potential candidate for colon cancer therapy.

MiR-150-5p represses TP53 tumor suppressor gene to promote proliferation of colon adenocarcinoma

MicroRNAs (miRNAs) play a critical role in regulation of numerous biological processes and pathogenesis of a variety of diseases. In addition, miRNAs contribute to carcinogenesis by acting as oncogenic or tumor suppressive. Circulating miRNAs including miR-150-5p are associated with colorectal cancer progression, and the putative targets of miR-150-5p include tumor suppressor gene, TP53. Here we sought to investigate the role of miR-150-5p-TP53 signaling pathway in proliferation of colon cancer and to determine expression levels of miR-miR-150-5p and TP53 in colon adenocarcinoma and adjacent non-cancerous tissue samples, or in human colon adenocarcinoma cell lines. MTT assay was used to determine proliferation and apoptosis in cell lines. Furthermore, we used Western blot to determine levels of cell cycle regulators with anti-miR-150-5p or apoptosis with overexpression of TP53. Our results show that expression levels of miR-150-5p were significantly elevated in clinical specimens from cancer patients. We further showed that inhibition of miR-150-5p increased TP53, and in turn, suppression of proliferation of colon adenocarcinoma. Moreover, inhibition of miR-150-5p or overexpression of TP53 caused cell arrest or apoptosis in colon adenocarcinoma. Our results support that miR-150-5p-TP53 pathway plays an important role in regulation of proliferation, cell arrest, and apoptosis in colon cancer, and could be an attractive target for therapy.

Effects of As2O3 and Resveratrol on the Proliferation and Apoptosis of Colon Cancer Cells and the hERG-mediated Potential Mechanisms.

: Background:As2O3 and resveratrol have been widely considered to be effective in anti-cancer therapies and the underlying mechanisms have been reported extensively. However, the combined treatment effect and potential target of As2O3 and resveratrol in the treatment of tumors remains elusive. The purpose of this study was to investigate the benefits and efficacy of As2O3 in combination with resveratrol in the treatment of colon cancer, as well as looking for new targets that could provide alternative explanation of the efficacy of drugs.Methods:The proliferation of cancer cells was measured by the MTT and EdU staining assay, while the apoptosis of cancer cells was determined by the flow cytometry. Western blot and immunoprecipitation were performed to measure the expression levels of proteins and the interaction between hERG and integrin β1, respectively.Results:In this study, we found that both As2O3 and resveratrol can effectively inhibit cell proliferation and promote cell apoptosis in colon cancer, and the combined effect of the two drugs on colon cancer cells is more preeminent. The combination of As2O3 with resveratrol, on the one hand reduced the expression of hERG channels on the membrane, and on the other hand weaken the binding between hERG and integrin β 1, which may be the main cause of downstream signaling pathways alterations, including the activation of the apoptotic pathway.Conclusion:Taken together, hERG, as a subunit of potassium ion channel on the cell membrane, is highly likely to be involved in the As2O3 and resveratrol induced intracellular signaling cascade disorder, and this novel signaling pathway that sustains the progression of colon cancer may be a promising therapeutic target for human colon cancer treatment in the future.

A novel protein encoded by a circular RNA circPPP1R12A promotes tumor pathogenesis and metastasis of colon cancer via Hippo-YAP signaling

BackgroundIt has been well established that circular RNAs (circRNAs) play an important regulatory role during tumor progression. Recent studies have indicated that even though circRNAs generally regulate gene expression through miRNA sponges, they may encode small peptides in tumor pathogenesis. However, it remains largely unexplored whether circRNAs are involved in the tumorigenesis of colon cancer (CC).MethodsThe expression profiles of circRNAs in CC tissues were assessed by circRNA microarray. Quantitative real-time PCR, RNase R digestion assay and tissue microarray were used to confirm the existence and expression pattern of circPPP1R12A. The subcellular distribution of circPPP1R12A was analyzed by nuclear mass separation assay and fluorescence in situ hybridization (FISH). SDS-PAGE and LC/MS were employed to evaluate the protein-coding ability of circPPP1R12A. CC cells were stably transfected with lentivirus approach, and cell proliferation, migration and invasion, as well as tumorigenesis and metastasis in nude mice were assessed to clarify the functional roles of circPPP1R12A and its encoded protein circPPP1R12A-73aa. RNA-sequencing and Western blotting analysis were furthered employed to identify the critical signaling pathway regulated by circPPP1R12A-73aa.ResultsWe firstly screened the expression profiles of human circRNAs in CC tissues and found that the expression of hsa_circ_0000423 (termed as circPPP1R12A) was significantly increased in CC tissues. We also found that circPPP1R12A was mostly localized in the cytoplasm of CC cells. Kaplan–Meier analysis showed that patients with higher levels of circPPP1R12A had a significantly shorter overall survival. By gain- and loss-of-function approaches, the results suggested that circPPP1R12A played a critical role in proliferation, migration and invasion of CC cells. Furthermore, we showed that circPPP1R12A carried an open reading frame (ORF), which encoded a functional protein (termed as circPPP1R12A-73aa). Next, we found that PPP1R12A-C, not circPPP1R12A, promoted the proliferation, migration and invasion abilities of CC in vitro and in vivo. Finally, we identified that circPPP1R12A-73aa promoted the growth and metastasis of CC via activating Hippo-YAP signaling pathway. In addition, the YAP specific inhibitor Peptide 17 dramatically alleviated the promotive effect of circPPP1R12A-73aa on CC cells.ConclusionsIn the present study, we illustrated the coding-potential of circRNA circPPP1R12A in the progression of CC. Moreover, we identified that circPPP1R12A-73aa promoted the tumor pathogenesis and metastasis of CC via activating Hippo-YAP signaling pathway. Our findings might provide valuable insights into the development of novel potential therapeutic targets for CC.

MicroRNA-193b acts as a tumor suppressor in colon cancer progression via targeting RAB22A.

To explore microRNA (miR)-193b expression and its potential role in colon cancer, reverse transcription-quantitative polymerase chain reaction was performed to detect the miR-193b expression levels in 62 colon cancer tissues and normal adjacent tissues. The miR-193b-overexpressed cell line SW620 was used to study the role of miR-193b in colon cancer. Subsequently, a Transwell assay and cell cycle assay were performed to observe the functional cell changes in the in vitro expression levels of miR-193b. Results indicated that miR-193b expression levels were significantly decreased in colon cancer tissues compared with adjacent normal tissue (P<0.001) and the expression of miR-193b was significantly correlated with TNM staging (P=0.03) and lymph node invasion (P=0.007). Furthermore, overexpression of miR-193b significantly decreased colon cancer cell cycle progression and its migration ability. In addition, the present findings suggested that the increased expression of miR-193b by RAB22A, inhibited downstream proteins involved in the Ras signaling pathway, including the Ras and extracellular signal-related kinase which may inhibit cancer proliferation and migration. In conclusion, the aim was to clarify the association of miR-193b expression with colon cancer, and to explore the mechanism of miR-193b in colon cancer proliferation and cell migration. The preliminary findings revealed that miR-193b may have an important role in the process in colon cancer cell cycle and migration by the RAB22A-Ras signaling pathway, thus providing a theoretical basis for miR-193b as a potential molecular target for colon cancer treatment.

Alkaloids from nux vomica suppresses colon cancer cell growth through Wnt/β-catenin signaling pathway.

Brucine and Strychnine are alkaloids isolated from the seeds of Strychnos nux vomica L., which have long been used as a traditional medicine for the treatment of tumor. However, the effect of Brucine and Strychnine on colorectal cancer (CRC) and the underlying molecular mechanism remain unclear. In the present study, Brucine and Strychnine displayed profound inhibitory effects on the growth of human colon cancer cells. The results of flow cytometric analysis demonstrated that the two alkaloids induced cellular apoptosis. Moreover, the growth of DLD1 xenografted tumors in nude mice was significantly suppressed in the Brucine or Strychnine treated group. Mechanistically, the Wnt/β-catenin is involved in this phenomenon, which is characterized by significantly increased expression of DKK1 and APC, whereas decreased expression of β-catenin, c-Myc, and p-LRP6 in CRC cells as well as tumor tissues. Collectively, Brucine and Strychnine have targeted inhibition for colon cancer proliferation both in vitro and in vivo, and it is valuable for future exploitation and utilization as an antitumor agent of CRC.

RETRACTED ARTICLE: Long non-coding XIAP-AS1 regulates cell proliferation, invasion and cell cycle in colon cancer

We, the Editors and Publisher of the journal Artificial Cells, Nanomedicine, and Biotechnology, have retracted the following article: Xiaohong Lu, Yuanjie Yu & Shiyun Tan (2019) Long non-coding XIAP-AS1 regulates cell proliferation, invasion and cell cycle in colon cancer. Artificial Cells, Nanomedicine, and Biotechnology, 47:1, 767–775, DOI: https://doi.org/10.1080/21691401.2019.1577880 It has come to our attention that the full authorship list and affiliations for this manuscript were changed after the article was submitted. We have contacted the author for an explanation, but we have not received a satisfactory explanation. As determining authorship is core to the integrity of published work, we are therefore retracting the article. The authors listed in this publication have been informed and do not agree with the retraction. We have been informed in our decision-making by our policy on publishing ethics and integrity and the COPE guidelines on retractions. The retracted article will remain online to maintain the scholarly record, but it will be digitally watermarked on each page as ‘Retracted’.

TET1 suppresses colon cancer proliferation by impairing β-catenin signal pathway.

The function of ten-eleven translocation methylcytosine dioxygenase 1 (TET1) in cancer is background dependent and may be involved in the initial step of active DNA demethylation, while there is little research to decipher the role of TET1 in DNA methylation-sensitive colon cancer. Downregulated TET1 expression assayed by quantitative real-time PCR (qRT-PCR) was observed in both colon cancer samples and cancer cell lines of HT29, HCT116, and SW48. Such downregulation could promote colon cancer cells proliferation as indicated by the fact that shTET1 could increase the viability of HT29 and HCT116 cells determined by the 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide and cell count assay accompanied with upregulation of β-catenin (CTNNB1) and WNT luciferase activity, which was further confirmed as shTET1 could increase the tumor volume and tumor weight, and decrease the body weight in HT29 cells inoculated BALB/C nude mice. The CTNNB1 transfection could rescue the cell growth diminished by normal expression of TET1. shTET1 could promote axis inhibition protein1 (AXIN1) expression and the cell proliferation effect induced by TET1 short hairpin RNA was attenuated by co-inhibition of AXIN1. All of these indicate that TET1 can suppress colon cancer proliferation and the inhibition of the β-catenin pathway is AXIN1 dependent.

Estradiol and progesterone regulate proliferation and apoptosis in colon cancer.

Epidemiological studies describe estrogens as protectors in the development of colon cancer in postmenopausal women treated with hormone replacement therapy. However, the role of progesterone in colon cancer has been minimally studied and the results are controversial. For the above, the objective of this work was to determine the hormonal regulation exerted by natural ovarian steroids on proliferation and apoptosis in an experimental model of colon cancer in ovariectomized rats treated with 17-beta estradiol and progesterone. Sprague–Dawley rats were exposed to the carcinogen 1,2-dimethylhydrazine to induce colon tumors. Thirty days later, the rats were ovariectomized and treated with estradiol (60 μg/kg), progesterone (10 mg/kg), estradiol plus progesterone (60 μg/kg and 10 mg/kg) or vehicle. We observed no significant differences in colon cancer incidence and tumor multiplicity between the groups. Nevertheless, we observed a decrease in PCNA expression and a greater number of apoptotic index, higher expression of caspase 3, cleaved PARP and cleaved caspase 8 in tumors, confirming the activation of the extrinsic pathway of apoptosis by the combined treatment. In addition, we observed a higher expression of estrogen receptor beta in these tumors. We conclude that the action of both hormones, estradiol and progesterone, is necessary to reduce proliferation and increase apoptosis in colon tumors, probably through estrogen receptor beta activation.