Adenomatous Polyposis Coli Expression Research Articles

Oxidative Stress Assessment in Colorectal Cancer Patients

Colorectal cancer (CRC), a global health challenge, exhibits rising incidence in low-income nations due to lifestyle changes. Oxidative stress, indicated by reactive oxygen species imbalance and Malondialdehyde (MDA), is linked to CRC. This study investigates oxidative stress markers, antioxidant enzymes, genetic markers, cellular regulation markers, and Vitamin E in CRC patients in Erbil. Ninety CRC patients and 30 healthy controls provided blood samples, processed and stored at –20°C. Enzyme-linked immunosorbent assay kits quantified oxidative stress, antioxidant markers, and Vitamin E. Oxidative stress markers showed significant differences, with elevated MDA and 8-hydroxy-2’-deoxyguanosine levels in patients. Nitrotyrosine exhibited lower expression in patients. Antioxidant enzymes glutathione peroxidase and superoxide dismutase were enhanced in patients, while glutathione (GSH), glutathione reductase and catalase levels were significantly lower in patients. The genetic marker KRAS showed a substantial decrease in patients (<0.0001) but both adenomatous polyposis coli (APC) and CRC antigen (CCA) were higher. Serum vitamin E levels were significantly lower in patients (71.78 ± 6.368) compared to controls (142.3 ± 4.828, p < 0.0001). Elevated oxidative stress, altered enzymatic activity, significantly lower expression of KRAS, and higher expression of APC and CCA in the patient group. Furthermore, reduced Vitamin E levels were observed in the patient group, highlighting potential challenges in antioxidant defense.

Identification of a novel CNV at the APC gene in a Chinese family with familial adenomatous polyposis.

Introduction: Familial adenomatous polyposis (FAP) is the second most commonly inherited colorectal cancer (CRC) predisposition caused by germline mutations within the adenomatous polyposis coli (APC) gene. The molecular defects and clinical manifestations of two FAP families were analyzed, and individual prevention strategies suitable for mutation carriers in different families were proposed. Methods and results: The pathogenic gene mutations were identified among the two families using whole-exome sequencing and verified with Sanger sequencing or quantitative polymerase chain reaction (qPCR). One novel (GRCh37:Chr5: 112145676-112174368, del, 28,692bp) and a known (c.C847T:p.R283X) mutation in the APC gene were pathogenic mutations for FAP, according to the sequencing data and tumorigenesis pattern among the family members. The two mutations led to a premature translational stop signal, synthesizing an absent or disrupted protein product. Conclusion: Our findings expand the known germline mutation spectrum of the APC gene among the Chinese population. This reaffirms the importance of genetic testing in FAP. Genetic consultation and regular follow-ups are necessary for the individualized treatment of cancer-afflicted families with APC expression deficiency. Additional work is required to develop safe and effective chemotherapy and immunotherapy for FAP based on the mutation type.

E74‑like ETS transcription factor 5 facilitates cell proliferation through regulating the expression of adenomatous polyposis coli 2 in non‑small cell lung cancer.

E74‑like ETS transcription factor 5 (ELF5) is known to regulate the specification and differentiation of epithelial cells in the embryonic lung. However, the pathological function of ELF5 in lung cancer has yet to be fully elucidated. In the present study, the expression of ELF5 was found to be significantly higher in lung adenocarcinoma compared with that in corresponding adjacent normal tissues. Subsequently, cell and animal experiments were performed to investigate the role of ELF5 in lung adenocarcinoma cells. The results indicated that the overexpression of ELF5 increased the proliferation of lung adenocarcinoma cells, whereas, by contrast, a reduction in the expression of ELF5 led to a decrease in their proliferation. Mechanistically, the hypothesis is advanced that ELF5 can promote lung cancer cell proliferation through inhibiting adenomatous polyposis coli 2 and increasing the expression of cyclin D1, which is a critical downstream target of the Wnt pathway. Taken together, these findings support the notion that ELF5 exerts an essential role in the proliferation of lung adenocarcinoma cells and may be a therapeutic target for the treatment of lung adenocarcinoma.

APC Loss Prevents Doxorubicin-Induced Cell Death by Increasing Drug Efflux and a Chemoresistant Cell Population in Breast Cancer.

Chemoresistance is a major health concern affecting cancer patients. Resistance is multifactorial, with one mechanism being the increased expression of ABC transporters (such as MDR1 and MRP1), which are drug efflux transporters capable of preventing intracellular accumulation of drugs and cell death. Our lab showed that the loss of Adenomatous Polyposis Coli (APC) caused an intrinsic resistance to doxorubicin (DOX), potentially through an enhanced tumor-initiating cell (TIC) population and the increased activation of STAT3 mediating the expression of MDR1 in the absence of WNT being activated. Here, in primary mouse mammary tumor cells, the loss of APC decreased the accumulation of DOX while increasing the protein levels of MDR1 and MRP1. We demonstrated decreased APC mRNA and protein levels in breast cancer patients compared with normal tissue. Using patient samples and a panel of human breast cancer cell lines, we found no significant trend between APC and either MDR1 or MRP1. Since the protein expression patterns did not show a correlation between the ABC transporters and the expression of APC, we evaluated the drug transporter activity. In mouse mammary tumor cells, the pharmacological inhibition or genetic silencing of MDR1 or MRP1, respectively, decreased the TIC population and increased DOX-induced apoptosis, supporting the use of ABC transporter inhibitors as therapeutic targets in APC-deficient tumors.

DNA methylation analysis of normal colon organoids from familial adenomatous polyposis patients reveals novel insight into colon cancer development

BackgroundFamilial adenomatous polyposis (FAP) is an inherited colorectal cancer (CRC) syndrome resulting from germ line mutations in the adenomatous polyposis coli (APC) gene. While FAP accounts for less than 1% of all CRC cases, loss of APC expression is seen in > 80% of non-hereditary CRCs. To better understand molecular mechanisms underlying APC-driven CRC, we performed an epigenome-wide analysis of colon organoids derived from normal-appearing colons of FAP patients versus healthy subjects to identify differentially methylated regions (DMRs) that may precede the onset of CRC.ResultsWe identified 358 DMRs when comparing colon organoids of FAP patients to those of healthy subjects (FDR < 0.05, |mean beta difference| = 5%). Of these, nearly 50% of DMRs were also differentially methylated in at least one of three CRC tumor and normal adjacent tissue (NAT) cohorts (TCGA-COAD, GSE193535 and ColoCare). Moreover, 27 of the DMRs mapped to CRC genome-wide association study (GWAS) loci. We provide evidence suggesting that some of these DMRs led to significant differences in gene expression of adjacent genes using quantitative PCR. For example, we identified significantly greater expression of five genes: Kazal-type serine peptidase inhibitor domain 1 (KAZALD1, P = 0.032), F-Box and leucine-rich repeat protein 8 (FBXL8, P = 0.036), TRIM31 antisense RNA 1 (TRIM31-AS1, P = 0.036), Fas apoptotic inhibitory molecule 2 (FAIM2, P = 0.049) and (Collagen beta (1–0)galactosyltransferase 2 (COLGALT2, P = 0.049). Importantly, both FBXL8 and TRIM31-AS1 were also significantly differentially expressed in TCGA-COAD tumor versus matched NAT, supporting a role for these genes in CRC tumor development.ConclusionsWe performed the first DNA methylome-wide analysis of normal colon organoids derived from FAP patients compared to those of healthy subjects. Our results reveal that normal colon organoids from FAP patients exhibit extensive epigenetic differences compared to those of healthy subjects that appear similar to those exhibited in CRC tumor. Our analyses therefore identify DMRs and candidate target genes that are potentially important in CRC tumor development in FAP, with potential implications for non-hereditary CRC.

Acalypha wilkesiana java white restored carbon tetrachloride (CCl4)-induced reno-hepatic tissue dysfunction in female albino rats

<h2>Summary</h2><h3>Background</h3> Many researchers now focus on discovering and exploring potentially protective medicinal plants against tissue toxicity. This study investigated the restorative effects of the ethanol extract of <i>Acalypha wilkesiana</i> java white (EEAW) on CCl₄-induced reno-hepatic tissue damage in rats. <h3>Case presentation</h3> Six groups of female albino rats containing six rats in each group were used. Groups A and B received 1 ml kg⁻¹body weight (bwt) of distilled water, while groups C and D received 200 mg kg⁻¹ bwt of vitamin C and EEAW, respectively. Groups E and F received 400 mg kg⁻¹bwt of the EEAW for seven days. All the oral administrations were done after induction of tissue damage by intraperitoneal injection of 1 ml kg⁻¹ bwt CCl₄ (50% v/v) to groups B, C, D and E. The EEAW ameliorated CCl₄ reno-hepatic tissue dysfunctions induction by significantly (<i>P</i> < 0.05), lowering the increased levels of alanine transaminase, aspartate transaminase, alkaline phosphatase, gamma-glutamyltransferase, lactate dehydrogenase, urea and creatinine in the serum. Molecular docking analysis showed the highest binding affinity of 2,6,10-trimethyldodecane, 2-Bromododecane, and 3-Methyltridecane to adenomatous polyposis coli (APC) protein. Also, immunohistochemical examination showed a reduced expression of APC after treatment with EEAW in both liver and kidney tissues. In addition, the histopathological evaluation showed regeneration of the liver and kidney cells. <h3>Conclusion</h3> This study concluded that <i>Acalypha wilkesiana</i> java white ethanol extract (EEAW) has restorative effects against CCl₄-induced reno-hepatic tissue dysfunctions.

Abstract 3246: APC loss prevents doxorubicin-induced cell death by effluxing drug and increasing a chemoresistant cell population

Abstract Chemoresistance is a leading cause of breast cancer related deaths. Therefore, understanding the molecular basis for chemoresistance is essential for novel therapeutic advancement and improving patient outcome. The Adenomatous Polyposis Coli (APC) tumor suppressor is lost in up to 70% of sporadic breast cancer; however, little is known about how APC loss contributes to chemoresistance. Using mammary tumor cells isolated from the ApcMin/+ mouse crossed to the Polyoma middle T antigen (PyMT) transgenic model, we made the novel observation that APC loss decreased doxorubicin (DOX) induced apoptosis. Therefore, we examined the mechanisms contributing to DOX resistance with APC loss to identify combination therapy options. We previously showed that APC loss in MMTV-PyMT;ApcMin/+ cells activated signal transducer and activator of transcription 3 (STAT3) thereby increasing the expression of the drug efflux pump, multidrug resistance protein 1 (MDR1). ATP-binding cassette (ABC) transporters, such as MDR1, are well established to contribute to drug resistance through exporting drugs from the cell. Furthermore, tumor initiating cells (TICs) have increased expression of ABC transporters and are known to be chemoresistant. We showed that MMTV-PyMT;ApcMin/+ cells have an increased TIC population. In addition, decreased intracellular DOX accumulation was observed in APC-deficient cells suggesting enhanced drug efflux. To investigate this decreased intracellular DOX accumulation, we measured the expression and activity of the drug export pumps, MDR1 and multidrug resistance protein 1 (MRP1). Using a small molecule inhibitor (Valspodar), we found that MDR1 inhibition restored the DOX-induced cleaved caspase 3 expression, demonstrating that MDR1 contributes to DOX resistance. MDR1 inhibition also increased the intracellular DOX accumulation in the APC-deficient cells and reduced the TICs. Genetic manipulation to silence MRP1 also increased DOX-induced apoptosis, increased DOX accumulation, and decreased the TICs in MMTV-PyMT;ApcMin/+ cells. To target both MDR1 and MRP1, a small molecule inhibitor (Reversan) was used to see if affecting both would offer more benefit. We again found that Reversan restored DOX sensitivity in MMTV-PyMT;ApcMin/+ cells through increasing DOX accumulation and decreasing TICs. Future studies include using a panel of human breast cancer cell lines to determine correlation of APC expression and DOX sensitivity. In addition, we will also evaluate patient tumor protein lysates for APC, MDR1, and MRP1 expression, followed by correlation studies to determine whether expression of APC inversely correlates with MDR1 or MRP1. Taken together, APC loss mediates DOX resistance via increasing DOX export and the TIC population demonstrating the potential use of combination therapy to overcome chemoresistance. Citation Format: Casey D. Stefanski, Janna Kotsen, Amy Bernard, Jenifer Prosperi. APC loss prevents doxorubicin-induced cell death by effluxing drug and increasing a chemoresistant cell population [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 3246.

Assessment of risk factors and molecular biomarkers in children with supernumerary teeth: a single-center study

BackgroundSupernumerary teeth are considered one of the commonly observed dental anomalies in children. Several theories have been proposed to explain the presence of supernumerary teeth, including environmental and genetic factors. This study aimed to identify the different risk factors and molecular biomarkers in patients presented with supernumerary teeth.MethodsThis case–control study included 240 children, 6 to 12-year-old. They were divided into a test group (n = 120 children presented with supernumerary teeth) and a control group (n = 120 children with no supernumerary teeth). Questionnaires were distributed to assess demographics and exposure to several environmental factors. Ten extracted supernumerary teeth from the test group were processed for histopathological analysis.ResultsMale gender, dental history of severe oral infection or medical history of chemotherapy treatment, previous history of taking medication or illness during pregnancy, family history of neoplastic disorders, use of electronic devices, and living beside agricultural fields or industrial areas were found to be statistically significant associated with the risk of supernumerary teeth development. Immunohistochemistry panel revealed that supernumerary teeth showed enhanced expression of wingless (Wnt) and sonic hedgehog (SHH) proteins as well as a reduced expression of adenomatous polyposis coli (APC) protein, denoting molecular derangement in a group of pathways classically believed to be involved in its pathogenesis.ConclusionsMales were more frequently affected by supernumerary teeth than females. Several risk factors were notably correlated with the existence of supernumerary teeth. Additionally, molecular biomarkers assessment demonstrated a high expression level of pro-tumorigenic proteins such as Wnt and SHH in patients with supernumerary teeth.

A pan-cancer analysis on the carcinogenic effect of human adenomatous polyposis coli.

Adenomatous polyposis coli (APC) is the most commonly mutated gene in colon cancer and can cause familial adenomatous polyposis (FAP). Hypermethylation of the APC promoter can also promote the development of breast cancer, indicating that APC is not limited to association with colorectal neoplasms. However, no pan-cancer analysis has been conducted. We studied the location and structure of APC and the expression and potential role of APC in a variety of tumors by using The Cancer Genome Atlas and Gene Expression Omnibus databases and online bioinformatics analysis tools. The APC is located at 5q22.2, and its protein structure is conserved among H. sapiens, M. musculus with C. elaphus hippelaphus. The APC identity similarity between homo sapiens and mus musculus reaches 90.1%. Moreover, APC is highly specifically expressed in brain tissues and bipolar cells but has low expression in most cancers. APC is mainly expressed on the cell membrane and is not detected in plasma by mass spectrometry. APC is low expressed in most tumor tissues, and there is a significant correlation between the expressed level of APC and the main pathological stages as well as the survival and prognosis of tumor patients. In most tumors, APC gene has mutation and methylation and an enhanced phosphorylation level of some phosphorylation sites, such as T1438 and S2260. The expressed level of APC is also involved in the level of CD8+ T-cell infiltration, Tregs infiltration, and cancer-associated fibroblast infiltration. We conducted a gene correlation study, but the findings seemed to contradict the previous analysis results of the low expression of the APC gene in most cancers. Our research provides a comparative wholesale understanding of the carcinogenic effects of APC in various cancers, which will help anti-cancer research.

Pleckstrin 2 is a potential drug target for colorectal carcinoma with activation of APC/β‑catenin.

The tumor suppressor gene adenomatous polyposis coli (APC) is frequently inactivated or absent in colorectal carcinoma (CRC). Loss-of-function of APC promotes the expression of β-catenin, which is critical for CRC development. Since β-catenin acts as an important transcription factor, blockage of β-catenin may have side effects, including impairment of tissue homeostasis and regeneration, thus limiting the application of β-catenin inhibitors for the treatment of patients with CRC. Therefore, identifying a novel substrate of APC/β-catenin may provide essential clues to develop effective drugs. Small interfering RNA technology and lentivirus-mediated overexpression were performed for knockdown and overexpression of pleckstrin 2 (PLEK2) in CRC cells. Cell Counting Kit-8 and colony formation assays, and cell cycle analysis and cell apoptosis detection were used to detect the capacity of cell proliferation, cell cycle distribution and apoptosis. The present study demonstrated that the APC/β-catenin signaling cascade transcriptionally activated PLEK2 in CRC cells. PLEK2 expression was markedly increased in CRC tissues. There was an inverse correlation between APC and PLEK2 expression in patients with CRC. In vitro, overexpression of PLEK2 increased the proliferation of CRC cells. Opposite results were observed in the cells with knockdown of PLEK2. Furthermore, PLEK2 promoted cell cycle progression and suppressed apoptosis. In summary, upregulation of PLEK2 contributed to CRC proliferation and colony formation activated by the APC/β-catenin signal pathway. Targeting PLEK2 may be important for the treatment of patients with CRC with activation of the APC/β-catenin signaling pathway.

Adenomatous Polyposis Coli loss controls cell cycle regulators and response to paclitaxel in MDA-MB-157 metaplastic breast cancer cells.

Adenomatous Polyposis Coli (APC) is lost in approximately 70% of sporadic breast cancers, with an inclination towards triple negative breast cancer (TNBC). TNBC is treated with traditional chemotherapy, such as paclitaxel (PTX); however, tumors often develop drug resistance. We previously created APC knockdown cells (APC shRNA1) using the human TNBC cells, MDA-MB-157, and showed that APC loss induces PTX resistance. To understand the mechanisms behind APC-mediated PTX response, we performed cell cycle analysis and analyzed cell cycle related proteins. Cell cycle analysis indicated increased G2/M population in both PTX-treated APC shRNA1 and parental cells, suggesting that APC expression does not alter PTX-induced G2/M arrest. We further studied the subcellular localization of the G2/M transition proteins, cyclin B1 and CDK1. The APC shRNA1 cells had increased CDK1, which was preferentially localized to the cytoplasm, and increased baseline CDK6. RNA-sequencing was performed to gain a global understanding of changes downstream of APC loss and identified a broad mis-regulation of cell cycle-related genes in APC shRNA1 cells. Our studies are the first to show an interaction between APC and taxane response in breast cancer. The implications include designing combination therapy to re-sensitize APC-mutant breast cancers to taxanes using the specific cell cycle alterations.

Abstract 1404: Loss of adenomatous polyposis coli induces DOX resistance through upregulation of ABC transporters

Abstract Chemoresistance is a leading cause of breast cancer related deaths. Therefore, understanding the molecular basis for chemoresistance is essential for novel therapeutic advancement improving patient outcome. The Adenomatous Polyposis Coli (APC) tumor suppressor is lost in up to 70% of sporadic breast cancer; however, little is known about how APC loss contributes to chemoresistance. Using mammary tumor cells isolated from the ApcMin/+ mouse crossed to the Polyoma middle T antigen (PyMT) transgenic model, we were the first to show that APC loss decreased doxorubicin (DOX) induced apoptosis. Therefore, we examined the mechanisms contributing to DOX resistance with APC loss to identify combination therapy options. We previously made the novel observation that APC loss in MMTV-PyMT;ApcMin/+ cells activated signal transducer and activator of transcription 3 (STAT3) thereby increasing the expression of the drug efflux pump, multidrug resistance protein 1 (MDR1). ATP-binding cassette (ABC) transporters, such as MDR1, are one of the most well-known contributors to drug resistance. These ABC transporters are capable of exporting drugs from the cell preventing apoptosis. Decreased intracellular DOX accumulation was observed in APC-deficient cells suggesting enhanced drug efflux. To investigate this decreased intracellular DOX accumulation, we measured the expression and activity of the drug export pumps, MDR1 and multidrug resistance protein 1 (MRP1). APC-deficient cells also have increased expression of MRP1. We used a calcein incorporation assay and demonstrated that APC loss increased MDR1 activity, which was restored by an MDR1 inhibitor. In addition, MDR1 inhibition sensitized the MMTV-PyMT;ApcMin/+ cells to DOX-mediated apoptosis. MRP1 inhibition through genetic manipulation will be used to assess MRP1 activity using the calcein AM assay and its contribution to DOX resistance. MDR1 and MRP1 inhibition will also be used to restore intracellular DOX accumulation. Future studies including evaluating human tumor protein lysates will for APC, MDR1, and MRP1 expression. Correlation studies will be used to determine whether loss of APC correlates with either high expression of MDR1 or MRP1. Taken together, APC loss mediates DOX resistance via exporting DOX demonstrating the potential use of combination therapy to overcome chemoresistance. Citation Format: Casey D. Stefanski, Jenifer R. Prosperi, Lauren Milac. Loss of adenomatous polyposis coli induces DOX resistance through upregulation of ABC transporters [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 1404.

METTL3 promotes tumour development by decreasing APC expression mediated by APC mRNA N6-methyladenosine-dependent YTHDF binding

The adenomatous polyposis coli (APC) is a frequently mutated tumour suppressor gene in cancers. However, whether APC is regulated at the epitranscriptomic level remains elusive. In this study, we analysed TCGA data and separated 200 paired oesophageal squamous cell carcinoma (ESCC) specimens and their adjacent normal tissues and demonstrated that methyltransferase-like 3 (METTL3) is highly expressed in tumour tissues. m6A-RNA immunoprecipitation sequencing revealed that METTL3 upregulates the m6A modification of APC, which recruits YTHDF for APC mRNA degradation. Reduced APC expression increases the expression of β-catenin and β-catenin-mediated cyclin D1, c-Myc, and PKM2 expression, thereby leading to enhanced aerobic glycolysis, ESCC cell proliferation, and tumour formation in mice. In addition, downregulated APC expression correlates with upregulated METTL3 expression in human ESCC specimens and poor prognosis in ESCC patients. Our findings reveal a mechanism by which the Wnt/β-catenin pathway is upregulated in ESCC via METTL3/YTHDF-coupled epitranscriptomal downregulation of APC.

TP53-Activated lncRNA GHRLOS Regulates Cell Proliferation, Invasion, and Apoptosis of Non-Small Cell Lung Cancer by Modulating the miR-346/APC Axis.

Non-small cell lung cancer (NSCLC) is the main type of lung cancer with high mortality worldwide. To improve NSCLC therapy, the exploration of molecular mechanisms involved in NSCLC progression and identification of their potential therapy targeting is important. Long noncoding RNAs (lncRNAs) have shown important roles in regulating various tumors progression, including NSCLC. We found lncRNA GHRLOS was decreased in NSCLC cell lines and tissues which correlated with poor prognosis of NSCLC patients. However, the role and underlying mechanisms of lncRNA GHRLOS in NSCLC progression remains elusive. The expression of lncRNA GHRLOS was examined in NSCLC cell lines and biopsy specimens of patients with NSCLC by quantitative real time polymerase chain reaction (qRT-PCR). The effects of GHRLOS on proliferation, invasion and apoptosis of NSCLC cells were determined by both in vitro and in vivo experiments. The interaction between GHRLOS and TP53 was determined by dual-luciferase reporter assay and chromatin immunoprecipitation (ChIP) combined with qRT-PCR analysis. RNA immunoprecipitation (RIP) was conducted to validate the binding between GHRLOS and microRNA-346 (miR-346). Dual-luciferase reporter assays were also carried out to reveal the interaction between miR-346 and the 3’ untranslated region (3’UTR) of adenomatous polyposis coli (APC) mRNA.Our data demonstrated that overexpression of lncRNA GHRLOS suppressed cancer cell proliferation and invasion as well as promoted cell apoptosis by regulating the expression of CDK2, PCNA, E-cadherin, N-cadherin, Bax, and Bcl-2 in NSCLC cells. Moreover, lncRNA GHRLOS was upregulated by the binding of TP53 to the GHRLOS promoter. The binding target of lncRNA GHRLOS was identified to be miR-346. Impressively, overexpression of miR-346 promoted cell proliferation and invasion, as well as inhibited cell apoptosis, however, these effects can be blocked by overexpression of lncRNA GHRLOS both in vitro and in vivo. In summary, this study reveals lncRNA GHRLOS, upregulated by TP53, acts as a molecule sponge of miR-346 to cooperatively modulates expression of APC, a miR-346 target, and potentially inhibits NSCLC progression via TP53/lncRNA GHRLOS/miR-346/APC axis, which represents a novel pathway that could be useful in targeted therapy against NSCLC.

ELEVATED ADENOMATOUS POLYPOSIS COLI IN GOBLET CELLS IS ASSOCIATED WITH INFLAMMATION IN MOUSE AND HUMAN COLON

Adenomatous Polyposis Coli (APC) functions as an essential colon tumor suppressor. Roles for APC in other disease states such as Inflammatory Bowel Disease (IBD) remain less defined. In the process of characterizing Apc protein in gastrointestinal tissues from human patients with active IBD, we found a subset of goblet cells with elevated Apc staining intensity. While normal colon tissue was only sparsely populated with these “APChigh” goblet cells, tissue from patients with Ulcerative Colitis and Crohn’s Disease contained entire regions where almost every goblet cell was APChigh. In the descending colon, the APChigh goblet cells were prominent in patients with active Ulcerative Colitis but were mostly lacking in normal samples. In mice, APChigh cells were observed only in the small intestines and proximal/medial colons. Upon induction of colitis with Dextran Sodium Sulfate (DSS), the APChigh goblet cells remained in the proximal and medial colon, but also appeared in the distal colon. To better understand the link between APC expression, goblet cells, and inflammation, cultured human colon cells derived from normal tissue were depleted of APC and RNAseq analysis was performed. APC depletion resulted in reduced expression of mRNAs encoding IL1 signaling pathway components IL1b and IL1R, known regulators of Muc2 expression. Muc2 is the main constituent of goblet cell mucus, which is secreted to form a protective barrier for the epithelial cells lining the large intestine. We found that treating cancer cells lacking wild-type APC with IL1b resulted in increased IL1R and MUC2 expression. Induction of full-length APC in these cells led to a similar phenotype. Combining IL1β treatment with APC induction led to an increase of MUC2 expression greater than expected for additive affects, suggesting that APC sensitized these cells to IL1 signaling. These results illuminate a novel role for APC in goblet cells under conditions of inflammation. We postulate that the higher amount of APC in a subset of goblet cells might sensitize them to IL-1 signaling. During times of inflammation, such as active Ulcerative Colitis, goblet cells with higher APC levels would be more sensitive to IL-1-induced MUC2 expression than other goblet cells, perhaps protecting the intestinal lining from further barrier breaches.

Quercetin ameliorates reactive oxygen species generation, inflammation, mucus depletion, goblet disintegration, and tumor multiplicity in colon cancer: Probable role of adenomatous polyposis coli, β-catenin.

1,2 Dimethyl hydrazine (DMH), a cogent environmental toxicant, targets the colon. Previous reports suggest that DMH-mediated dysregulation of the Wnt/β-catenin pathway plays a vital role in the initial events of colon carcinogenesis. Our study was designed to investigate the effect of quercetin on DMH-mediated colon cancer by targeting adenomatous polyposis coli (APC) and β-catenin in Wistar rats. Animals were pretreated orally with quercetin at doses of either 25 or 50 mg/kg bodyweight (bw) and DMH at a dose of 20 mg/kg bw subcutaneously up to the 15th week and sacrificed after the 30th week. DMH administration leads to reactive oxygen species generation, resulting in an imbalance in redox homeostasis and causing membrane lipid peroxidation, which is also partly due to the decrease in the level of tissue antioxidant machinery. Increased inflammatory and proliferative proteins were observed in DMH-induced colon cancerous rats. DMH treatment also led to dysregulation in the apoptotic pathway with decreased Bax:Bcl-2 ratio. Quercetin pretreatment ameliorates DMH-induced proliferation, activities of detoxifying enzymes, and putative early markers (mucin depletion and goblet cell disintegration) in colonic tissue. It also significantly regulates APC and β-catenin expression and inhibits tumor incidence and multiplicity. Histological results further confirm the beneficial role of quercetin in averting DMH-induced pathological alterations.

Risk Assessment in Hereditary Colorectal Cancer Family by Using APC and MSH2 mRNA Gene Expression and Bayesian Analysis

BACKGROUND: Some of colorectal cancers (CRCs) are familial, however, heterozygote relatives have approximately 80% lifetime risk of cancer. Risk assessment of CRC’s family could be calculated by direct measurement of mRNA gene expression and Bayesian theorem which is modifying initial background of pedigree risk with additional conditional information. This application has not been reported.METHODS: The cross-sectional translational sequential studies were performed: (1) adenomatous polyposis coli (APC) and MutS homolog (MSH)2 mRNA quantitative RT PCR gene expressions in tissue and whole blood CRC patients; (2) gene expression was determined in matched controls; and (3) pedigree and Bayesian analysis was calculated in the patient’s family of Proband.RESULTS: Fourty CRC and 31 control subjects were enrolled. The mean blood APC level control’s group was 13,261±670 fold-change (fc) and blood MSH2 level was 12,219±756 fc. The cut-off points for hereditary APC was 12,195 fc and MSH2 was 11,059 fc. The mean APC blood level in CRC subject was 11,578±2,638 fc and MSH2 blood level was 11,411±2,912 fc. There were significant differences APC and MSH level between tissue and blood level in CRC. Eight of 40 CRC subjects had a history of familial CRC. Four patients and 10 Probands were available for recurrence risk evaluation of pedigree analysis, RNA PCR quantitative and Bayesian calculation.CONCLUSION: There was determined a cut-off point of hereditary mRNA quantitative expression. The APC and MSH2 levels in CRC subjects were significantly lower than controls. Bayesian analysis allowed for the calculation of relative risk in CRC family members and considered in clinical practice.KEYWORDS: hereditary CRC, APC gene, MSH gene, Bayesian analysis

APC Promoter Hypermethylation as a Prognostic Marker in Breast Cancer Patients.

Background:Adenomatous polyposis coli (APC) promoter hypermethylation implicated in breast cancer development through Wnt signaling pathway, hypermethylation may result in inactivation of APC expression. This study aimed to investigated whether hypermethylation of APC promoter, the aggressive behavior of breast cancer cells, and correlated them with clinicopathological parameters and survival. Methods:Sixty-one fresh tissues of breast tumor were evaluated for APC promoter hypermethylation with methylation-specific PCR techniques (MS-PCR) and APC mRNA expression level analysis by quantitative real-time reverse transcription-PCR. Results:Our results show aberrant APC hypermethylation status was founded in 27 of 61 cases (44%), and significantly associated with chemotherapy treatment (OR= 6.9, 95%CI=1.5-31.01, P = 0.01), distant metastasis (OR = 5.52, 95%CI = 1.27-24.08, P = 0.04) as well as APC methylated status also associated with shorter overall survival than those without (8.4 and 11.0 years respectively, P = 0.02). Conclusion:The findings indicated hypermethylation of APC promoter may be used as a useful prognostic biomarker in breast cancer patients.

APC regulation of ESRP1 and p120-catenin isoforms in colorectal cancer cells.

The adenomatous polyposis coli (APC) tumor suppressor protein is associated with the regulation of Wnt signaling; however, APC also controls other cellular processes including the regulation of cell adhesion and migration. The expression of full-length APC in SW480 colorectal cancer cells (SW480+APC) not only reduces Wnt signaling, but increases membrane E-cadherin and restores cell–cell adhesion. This report describes the effects of full-length, wild-type APC (fl-APC) on cell–cell adhesion genes and p120-catenin isoform switching in SW480 colon cancer cells: fl-APC increased the expression of genes implicated in cell–cell adhesion, whereas the expression of negative regulators of E-cadherin was decreased. Analysis of cell–cell adhesion-related proteins in SW480+APC cells revealed an increase in p120-catenin isoform 3A; similarly, depletion of APC altered the p120-catenin protein isoform profile. Expression of ESRP1 (epithelial splice regulatory protein 1) is increased in SW480+APC cells, and its depletion results in reversion to the p120-catenin isoform 1A phenotype and reduced cell–cell adhesion. The ESRP1 transcript is reduced in primary colorectal cancer, and its expression correlates with the level of APC. Pyrvinium pamoate, which inhibits Wnt signaling, promotes ESRP1 expression. We conclude that re-expression of APC restores the cell–cell adhesion gene and posttranscriptional regulatory programs leading to p120-catenin isoform switching and associated changes in cell–cell adhesion.

Circular RNA circFGD4 suppresses gastric cancer progression via modulating miR-532-3p/APC/β-catenin signalling pathway.

Mounting evidence has displayed critical roles of circular RNAs (circRNAs) in multiple cancers. The underlying mechanisms by which circFGD4 contributed to gastric cancer (GC) are still unclear. The levels and clinical values of circFGD4 in GC patients were detected and analysed by quantitative real-time PCR. The biological roles of circFGD4 in GC were assessed in vitro and in vivo experiments. Dual-luciferase reporter, fluorescence in situ hybridization, RNA immunoprecipitation, biotin-coupled RNA pull-down, and TOP/Flash and FOP/Flash reporter gene assays were employed to evaluate the effects of circFGD4 on miR-532-3p-mediated adenomatous polyposis coli (APC)/β-catenin signalling in GC cells. circFGD4 expression was down-regulated the most in human GC tissues and cell lines. Low expression of circFGD4 was correlated with poor tumour differentiation, lymphatic metastasis, and poor prognosis of GC patients. circFGD4 suppressed GC cell viability, colony formation, migration, induced epithelial-mesenchymal transition (EMT), and tumorigenesis and metastasis in vivo. Next, we validated that circFGD4 acted as a sponge of miR-532-3p to relieve the tumour-promoting effects of miR-532-3p on its target APC. The mechanistic analysis demonstrated that the circFGD4 suppressed GC cell viability, migration, and EMT by modulating the miR-532-3p/APC axis to inactivate the β-catenin signalling. circFGD4 suppressed GC progression through sponging miR-532-3p and enhancing APC expression to inactivate the β-catenin signalling. Thus circFGD4 provides a novel potential biomarker and valuable therapeutic strategy for GC.