Wnt/beta-catenin/tcf signaling: a critical pathway in gastrointestinal tumorigenesis

Microcystin-leucine arginine induces the proliferation of cholangiocytes and cholangiocarcinoma cells through the activation of the Wnt/β-catenin signaling pathway

Background

Microcystin-leucine arginine (MC-LR) is a cyanobacterial hepatotoxic toxin found in water sources worldwide, including in northeastern Thailand, where opisthorchiasis-associated cholangiocarcinoma (CCA) is most prevalent. MC-LR is a potential carcinogen; however, its involvement in liver fluke-associated CCA remains ambiguous. Here, we aimed to evaluate the effect of MC-LR on the progression of CCA via the Wnt/β-catenin pathway in vitro.

Methods

Cell division, migration, cell cycle transition, and MC-LR transporter expression were evaluated in vitro through MTT assay, wound healing assay, flow cytometry, and immunofluorescence staining, respectively. Following a 24-h treatment of cultured cells with 1, 10, 100, and 1,000 nM of MC-LR, the proliferative effect of MC-LR on the Wnt/β-catenin signaling pathway was investigated using immunoblotting and qRT-PCR analysis. Immunohistochemistry was used to determine β-catenin expression in CCA tissue compared to adjacent tissue.

Results

Human immortalized cholangiocyte cells (MMNK-1) and a human cell line established from opisthorchiasis-associated CCA (KKU-213B) expressed the MC-LR transporter and internalized MC-LR. Exposure to 10 nM and 100 nM of MC-LR notably enhanced cells division and migration in both cell lines (P < 0.05) and markedly elevated the percentage of S phase cells (P < 0.05). MC-LR elevated PP2A expression by activating the Wnt/β-catenin signaling pathway and suppressing phosphatase activity. Inhibition of the β-catenin destruction complex genes (Axin1 and APC) led to the upregulation of β-catenin and its downstream target genes (Cyclin D1 and c-Jun). Inhibition of Wnt/β-catenin signaling by MSAB confirmed these results. Additionally, β-catenin was significantly expressed in cancerous tissue compared to adjacent areas (P < 0.001).

Conclusions

Our findings suggest that MC-LR promotes cell proliferation and progression of CCA through Wnt/β-catenin pathway. Further evaluation using invivo experiments is needed to confirm this observation. This finding could promote health awareness regarding MC-LR intake and risk of CCA.

miR-939, as an important regulator in various cancers pathogenesis, has diagnostic, prognostic, and therapeutic values: a review

BACKGROUND

MicroRNAs (miRNAs or miRs) are highly conserved non-coding RNAs with a short length (18-24 nucleotides) that directly bind to a complementary sequence within 3'-untranslated regions of their target mRNAs and regulate gene expression, post-transcriptionally. They play crucial roles in diverse biological processes, including cell proliferation, apoptosis, and differentiation. In the context of cancer, miRNAs are key regulators of growth, angiogenesis, metastasis, and drug resistance.

MAIN BODY

This review primarily focuses on miR-939 and its expanding roles and target genes in cancer pathogenesis. It compiles findings from various investigations. MiRNAs, due to their dysregulated expression in tumor environments, hold potential as cancer biomarkers. Several studies have highlighted the dysregulation of miR-939 expression in human cancers.

CONCLUSION

Our study highlights the potential of miR-939 as a valuable target in cancer diagnosis, prognosis, and treatment. The aberrant expression of miR-939, along with other miRNAs, underscores their significance in advancing our understanding of cancer biology and their promise in personalized cancer care.

Targeting beta-catenin signaling for prevention of colorectal cancer - Nutraceutical, drug, and dietary options

Progressive up-regulation of β-catenin signaling is very common in the transformation of colorectal epithelium to colorectal cancer (CRC). Practical measures for opposing such signaling hence have potential for preventing or slowing such transformation. cAMP/PKA activity in colon epithelium, as stimulated by COX-2-generated prostaglandins and β2-adrenergic signaling, boosts β-catenin activity, whereas cGMP/PKG signaling has the opposite effect. Bacterial generation of short-chain fatty acids (as supported by unrefined high-carbohydrate diets, berberine, and probiotics), dietary calcium, daily aspirin, antioxidants opposing cox-2 induction, and nicotine avoidance, can suppress cAMP production in colonic epithelium, whereas cGMP can be boosted via linaclotides, PDE5 inhibitors such as sildenafil or icariin, and likely high-dose biotin. Selective activation of estrogen receptor-β by soy isoflavones, support of adequate vitamin D receptor activity with UV exposure or supplemental vitamin D, and inhibition of CK2 activity with flavanols such as quercetin, can also oppose β-catenin signaling in colorectal epithelium. Secondary bile acids, the colonic production of which can be diminished by low-fat diets and berberine, can up-regulate β-catenin activity by down-regulating farnesoid X receptor expression. Stimulation of PI3K/Akt via insulin, IGF-I, TLR4, and EGFR receptors boosts β-catenin levels via inhibition of glycogen synthase-3β; plant-based diets can down-regulate insulin and IGF-I levels, exercise training and leanness can keep insulin low, anthocyanins and their key metabolite ferulic acid have potential for opposing TLR4 signaling, and silibinin is a direct antagonist for EGFR. Partially hydrolyzed phytate can oppose growth factor-mediated down-regulation of β-catenin by inhibiting Akt activation. Multifactorial strategies for safely opposing β-catenin signaling can be complemented with measures that diminish colonic mutagenesis and DNA hypomethylation - such as avoidance of heme-rich meat and charred or processed meats, consumption of phase II-inductive foods and nutraceuticals (e.g., Crucifera), and assurance of adequate folate status.

Establishment of a large-scale patient-derived high-risk colorectal adenoma organoid biobank for high-throughput and high-content drug screening

BACKGROUND

Colorectal adenoma (CA), especially high-risk CA (HRCA), is a precancerous lesion with high prevalence and recurrence rate and accounts for about 90% incidence of sporadic colorectal cancer cases worldwide. Currently, recurrent CA can only be treated with repeated invasive polypectomies, while safe and promising pharmaceutical invention strategies are still missing due to the lack of reliable in vitro model for CA-related drug screening.

METHODS

We have established a large-scale patient-derived high-risk colorectal adenoma organoid (HRCA-PDO) biobank containing 37 PDO lines derived from 33 patients and then conducted a series of high-throughput and high-content HRCA drug screening.

RESULTS

We established the primary culture system with the non-WNT3a medium which highly improved the purity while maintained the viability of HRCA-PDOs. We also proved that the HRCA-PDOs replicated the histological features, cellular diversity, genetic mutations, and molecular characteristics of the primary adenomas. Especially, we identified the dysregulated stem genes including LGR5, c-Myc, and OLFM4 as the markers of adenoma, which are well preserved in HRCA-PDOs. Based on the HRCA-PDO biobank, a customized 139 compound library was applied for drug screening. Four drugs including metformin, BMS754807, panobinostat and AT9283 were screened out as potential hits with generally consistent inhibitory efficacy on HRCA-PDOs. As a representative, metformin was discovered to hinder HRCA-PDO growth in vitro and in vivo by restricting the stemness maintenance.

CONCLUSIONS

This study established a promising HRCA-PDO biobank and conducted the first high-throughput and high-content HRCA drug screening in order to shed light on the prevention of colorectal cancer.

PNU-74654 Induces Cell Cycle Arrest and Inhibits EMT Progression in Pancreatic Cancer

Background and Objectives: PNU-74654, a Wnt/β-catenin pathway inhibitor, has an antiproliferative effect on many cancer types; however, its therapeutic role in pancreatic cancer (PC) has not yet been demonstrated. Here, the effects of PNU-74654 on proliferation and cell cycle phase distribution were studied in PC cell lines. Materials and Methods: The cancer-related molecular pathways regulated by PNU-74654 were determined by a proteome profiling oncology array and confirmed by western blotting. Results: The cell viability and proliferative ability of PC cells were decreased by PNU-74654 treatment. G1 arrest was observed, as indicated by the downregulation of cyclin E and cyclin-dependent kinase 2 (CDK2) and the upregulation of p27. PNU-74654 inhibited the epithelial-mesenchymal transition (EMT), as determined by an increase in E-cadherin and decreases in N-cadherin, ZEB1, and hypoxia-inducible factor-1 alpha (HIF-1α). PNU-74654 also suppressed cytoplasmic and nuclear β-catenin and impaired the NF-κB pathway. Conclusions: These results demonstrate that PNU-74654 modulates G1/S regulatory proteins and inhibits the EMT, thereby suppressing PC cell proliferation, migration, and invasion. The synergistic effect of PNU-74654 and chemotherapy or the exclusive use of PNU-74654 may be therapeutic options for PC and require further investigation.

Galectin-3 Mediates Tumor Progression in Astrocytoma by Regulating Glycogen Synthase Kinase-3β Activity

Numerous studies have considered galectin-3 or Glycogen synthase kinase 3 beta (GSK3B) as a potential prognosis marker for various cancers. However, the correlation between the protein expression of galectin-3/GSK3B and the clinical parameters of astrocytoma has not been reported. This study aims to validate the correlation between the clinical outcomes and protein expression of galectin-3/GSK3B in astrocytoma. Immunohistochemistry staining was performed to detect galectin-3/GSK3B protein expression in patients with astrocytoma. The Chi-square test, Kaplan-Meier evaluation, and Cox regression analysis were used to determine the correlation between clinical parameters and galectin-3/GSK3B expression. Cell proliferation, invasion, and migration were compared between a non-siRNA group and a galectin-3/GSK3B siRNA group. Protein expression in galectin-3 or GSK3B siRNA-treated cells was evaluated using western blotting. Galectin-3 and GSK3B protein expression were significantly positively correlated with the World Health Organization (WHO) astrocytoma grade and overall survival time. Multivariate analysis revealed that WHO grade, galectin-3 expression, and GSK3B expression were independent prognostic factors for astrocytoma. Galectin-3 or GSK3B downregulation induced apoptosis and decreased cell numbers, migration, and invasion. siRNA-mediated gene silencing of galectin-3 resulted in the downregulation of Ki-67, cyclin D1, VEGF, GSK3B, p-GSK3B Ser9 (p-GSK3B S9), and β-catenin. In contrast, GSK3B knockdown only decreased Ki-67, VEGF, p-GSK3B S9, and β-catenin protein expression but did not affect cyclin D1 and galectin-3 protein expression. The siRNA results indicated that GSK3B is downstream of the galectin-3 gene. These data support that galectin-3 mediated tumor progression by upregulating GSK3B and β-catenin protein expression in glioblastoma. Therefore, galectin-3 and GSK3B are potential prognostic markers, and their genes may be considered to be anticancer targets for astrocytoma therapy.

Novel read through agent: ZKN-0013 demonstrates efficacy in APCmin model of familial adenomatous polyposis

Familial adenomatous polyposis (FAP) is a precancerous, colorectal disease characterized by hundreds to thousands of adenomatous polyps caused by mutations in the tumor suppressor gene adenomatous polyposis coli (APC). Approximately 30% of these mutations are premature termination codons (PTC), resulting in the production of a truncated, dysfunctional APC protein. Consequently, the β-catenin degradation complex fails to form in the cytoplasm, leading to elevated nuclear levels of β-catenin and unregulated β-catenin/wnt-pathway signaling. We present in vitro and in vivo data demonstrating that the novel macrolide, ZKN-0013, promotes read through of premature stop codons, leading to functional restoration of full-length APC protein. Human colorectal carcinoma SW403 and SW1417 cells harboring PTC mutations in the APC gene showed reduced levels of nuclear β-catenin and c-myc upon treatment with ZKN-0013, indicating that the macrolide-mediated read through of premature stop codons produced bioactive APC protein and inhibited the β-catenin/wnt-pathway. In a mouse model of adenomatous polyposis coli, treatment of APC^min mice with ZKN-0013 caused a significant decrease in intestinal polyps, adenomas, and associated anemia, resulting in increased survival. Immunohistochemistry revealed decreased nuclear β-catenin staining in the epithelial cells of the polyps in ZKN-0013-treated APC^min mice, confirming the impact on the β-catenin/wnt-pathway. These results indicate that ZKN-0013 may have therapeutic potential for the treatment of FAP caused by nonsense mutations in the APC gene. KEY MESSAGES: • ZKN-0013 inhibited the growth of human colon carcinoma cells with APC nonsense mutations. • ZKN-0013 promoted read through of premature stop codons in the APC gene. • In APC^min mice, ZKN-0013 treatment reduced intestinal polyps and their progression to adenomas. • ZKN-0013 treatment in APC^min mice resulted in reduced anemia and increased survival.

DNA methylation in peripheral blood leukocytes for the association with glucose metabolism and invasive breast cancer

BACKGROUND

Insulin resistance (IR) is a well-established factor for breast cancer (BC) risk in postmenopausal women, but the interrelated molecular pathways on the methylome are not explicitly described. We conducted a population-level epigenome-wide association (EWA) study for DNA methylation (DNAm) probes that are associated with IR and prospectively correlated with BC development, both overall and in BC subtypes among postmenopausal women.

METHODS

We used data from Women's Health Initiative (WHI) ancillary studies for our EWA analyses and evaluated the associations of site-specific DNAm across the genome with IR phenotypes by multiple regressions adjusting for age and leukocyte heterogeneities. For our analysis of the top 20 IR-CpGs with BC risk, we used the WHI and the Cancer Genomic Atlas (TCGA), using multiple Cox proportional hazards and logit regressions, respectively, accounting for age, diabetes, obesity, leukocyte heterogeneities, and tumor purity (for TCGA). We further conducted a Gene Set Enrichment Analysis.

RESULTS

We detected several EWA-CpGs in TXNIP, CPT1A, PHGDH, and ABCG1. In particular, cg19693031 in TXNIP was replicated in all IR phenotypes, measured by fasting levels of glucose, insulin, and homeostatic model assessment-IR. Of those replicated IR-genes, 3 genes (CPT1A, PHGDH, and ABCG1) were further correlated with BC risk; and 1 individual CpG (cg01676795 in POR) was commonly detected across the 2 cohorts.

CONCLUSIONS

Our study contributes to better understanding of the interconnected molecular pathways on the methylome between IR and BC carcinogenesis and suggests potential use of DNAm markers in the peripheral blood cells as preventive targets to detect an at-risk group for IR and BC in postmenopausal women.

Proapoptotic and Antiproliferative Effects of the Desert Truffle Terfezia boudieri on Colon Cancer Cell Lines

Background

Colon cancer is the second leading cause of cancer-related mortality, and ranks third among cancers in terms of prevalence. Despite advances in early detection and treatment with chemotherapy and surgery, colon cancer continues to be associated with high recurrence rates, thereby resulting in a heavy disease burden. Moreover, the effectiveness of currently available treatment modalities is limited by the occurrence of toxic side effects. Hence, there is an urgent need to develop alternative treatments. Extracts from the black desert truffle Terfezia boudieri (T. boudieri) have shown promising anticancer properties. However, the cellular mechanisms underlying this activity remain poorly understood.

Methods

In this study, the colon cancer cell lines HCT-116 and Caco-2 were treated with either water or ethanolic extract of T. boudieri. Cell viability and the half-maximal inhibitory concentration were determined using MTT assays. Then, the activity of the more potent water extract was further verified using crystal violet assays, and its role in inhibiting colony formation and wound healing was investigated. Protein levels of p53, B-cell lymphoma 2 (Bcl-2), Bcl-2-associated X (Bax), cyclin D1 (CCND1), and c-Myc were measured in cells treated with different doses of the water extract.

Results

Treatment with the water extract of T. boudieri reduced the capacity of cells for wound healing and colony formation in a dose-dependent manner. The Bax/Bcl-2 ratio and p53 expression were elevated in both cell lines. In contrast, the levels of cyclin D1 and c-Myc were suppressed.

Conclusion

T. boudieri water extract exerted a cytotoxic effect on colon cancer cells, and blocked colony formation and wound healing potentially through inhibition of proliferation. Mechanistically, these effects are attributed to influence the mitochondrial pathway of apoptosis, proteins involved in cellular proliferation, and the cell cycle.

Nitazoxanide inhibits osteosarcoma cells growth and metastasis by suppressing AKT/mTOR and Wnt/β-catenin signaling pathways

Osteosarcoma (OS) is the most prevalent malignant bone tumor with poor prognosis. Developing new drugs for the chemotherapy of OS has been a focal point and a major obstacle of OS treatment. Nitazoxanide (NTZ), a conventional anti-parasitic agent, has got increasingly noticed because of its favorable antitumor potential. Herein, we investigated the effect of NTZ on human OS cells in vitro and in vivo. The results obtained in vitro showed that NTZ inhibited the proliferation, migration and invasion, arrested cell cycle at G1 phase, while induced apoptosis of OS cells. Mechanistically, NTZ suppressed the activity of AKT/mTOR and Wnt/β-catenin signaling pathways of OS cells. Consistent with the results in vitro, orthotopic implantation model of 143B OS cells further confirmed that NTZ inhibited OS cells growth and lung metastasis in vivo. Notably, NTZ caused no apparent damage to normal cells/tissues. In conclusion, NTZ may inhibit tumor growth and metastasis of human OS cells through suppressing AKT/mTOR and Wnt/β-catenin signaling pathways.

Manpixiao Decoction Halted the Malignant Transformation of Precancerous Lesions of Gastric Cancer: From Network Prediction to In-Vivo Verification

Manpixiao decoction (MPX), a traditional Chinese medicine formula, is mainly used to improve the gastric mucosal pathology and stomach discomfort in patients with gastric precancerous lesions. Precancerous lesion of gastric cancer (PLGC) refers to intestinal metaplasia and/or dysplasia based on gastric mucosal atrophy. Effective prevention and treatment of PLGC is of great significance to reduce the incidence of gastric cancer. Because of the complexity of the etiology and pathogenesis of PLGC, there is no unified and effective treatment plan in western medicine. In recent years, traditional Chinese medicine has shown obvious advantages in the treatment of PLGC and the prevention of its further progression to gastric cancer, relying on its multi-approach and multi-target comprehensive intervention characteristics. This study is designed to examine the protective effect of MPX against PLGC and further to reveal the engaged mechanism via integrating network pharmacology and in vivo experimental evidence. Network pharmacology results demonstrated that inflammation, immune responses, and angiogenesis might be associated with the efficacy of MPX in the treatment of PLGC, in which the PI3K-Akt, cellular senescence, P53 and protein processing in endoplasmic reticulum were involved. Then, we established a rat model of PLGC using a combination of N-methyl-N′-nitro-N-nitrosoguanidine (MNNG), sodium salicylate, irregular fasting, and ranitidine, and observed the effects after MPX treatment. Our result showed that MPX improved the pathological condition of gastric mucosa in PLGC rats and reduced the incidence of gastric cancer. Next, the analysis of serum inflammatory cytokines showed that MPX reduced the inflammation-related cytokines (such as IL-1α, IL-7, CSF-1, and CSF-3) in the serum. Additionally, MPX also had a regulation effect on the “protein/protein phosphorylation-signaling pathway” network in the core region of the PLGC rats. It is showed that MPX can inhibit the phosphorylation of PI3K-AKT, and downregulates the EGFR, β-catenin, and N-cadherin protein levels. These results indicate that MPX halted the PLGC progression through inhibiting EGFR-PI3K-AKT related epithelial-mesenchymal transition process.

Single-cell and bulk transcriptome sequencing identifies two epithelial tumor cell states and refines the consensus molecular classification of colorectal cancer

The consensus molecular subtype (CMS) classification of colorectal cancer is based on bulk transcriptomics. The underlying epithelial cell diversity remains unclear. We analyzed 373,058 single-cell transcriptomes from 63 patients, focusing on 49,155 epithelial cells. We identified a pervasive genetic and transcriptomic dichotomy of malignant cells, based on distinct gene expression, DNA copy number and gene regulatory network. We recapitulated these subtypes in bulk transcriptomes from 3,614 patients. The two intrinsic subtypes, iCMS2 and iCMS3, refine CMS. iCMS3 comprises microsatellite unstable (MSI-H) cancers and one-third of microsatellite-stable (MSS) tumors. iCMS3 MSS cancers are transcriptomically more similar to MSI-H cancers than to other MSS cancers. CMS4 cancers had either iCMS2 or iCMS3 epithelium; the latter had the worst prognosis. We defined the intrinsic epithelial axis of colorectal cancer and propose a refined ‘IMF’ classification with five subtypes, combining intrinsic epithelial subtype (I), microsatellite instability status (M) and fibrosis (F).

A single-cell transcriptomic analysis of 63 patients with colorectal cancer classifies tumor cells into two epithelial subtypes. An improved tumor classification based on epithelial subtype, microsatellite stability and fibrosis reveals differences in pathway activation and metastasis.

Restraint of FAM60A has a cancer-inhibiting role in pancreatic carcinoma via the effects on the Akt/GSK-3β/β-catenin signaling pathway

Family with sequence similarity 60A (FAM60A) has been reported as a new cancer-related protein that affects the malignant progression of some cancers. However, whether FAM60A plays a part in pancreatic carcinoma is undetermined. This work was designed to examine the impact of FAM60A in pancreatic carcinoma. Abundant expression of FAM60A was observed in the primary tumor tissue of pancreatic carcinoma. Moreover, a high FAM60A level was related to a poor overall survival in pancreatic carcinoma patients. Malignant behaviors of pancreatic carcinoma cells, such as proliferation and invasiveness, were markedly affected by FAM60A depletion. In addition, FAM60A depletion enhanced the drug sensitivity of pancreatic carcinoma cells to gemcitabine. Further study revealed that FAM60A depletion impaired the activities of Akt and β-catenin. Inhibiting the activity of Akt abolished FAM60A-mediated β-catenin activation. Re-expression of β-catenin partially diminished the FAM60A-depletion-mediated cancer suppressive effect in pancreatic carcinoma cells. In vivo experiments demonstrated that FAM60A depletion prohibited the xenograft formation of pancreatic carcinoma cells, with concurrent reductions of Akt and β-catenin activities. Collectively, our findings indicate that FAM60A exerts a cancer-promoting role in pancreatic carcinoma through affection of the Akt/β-catenin pathway. This work indicates that FAM60A acts as a tumor promoter in pancreatic carcinoma and can be utilized as a potential target for anti-pancreatic carcinoma therapy development.

Calcium-binding protein S100P is a new target gene of MACC1, drives colorectal cancer metastasis and serves as a prognostic biomarker

Background

The metastasis inducing gene MACC1 is a prognostic and predictive biomarker for metastasis in several cancers. Its mechanism of inducing metastasis includes the transcriptional control of other cancer-related target genes. Here, we investigate the interplay with the metastasis driver S100P in CRC progression.

Methods

MACC1-dependent S100P expression was analysed by qRT-PCR. The binding of MACC1 to the S100P promoter was determined by ChIP. Alterations in cell proliferation and motility were determined by functional in vitro assays. In vivo metastasis after intrasplenic transplantation was assessed by bioluminescence imaging and evaluation of tumour growth and liver metastasis. The prognostic value of S100P was determined in CRC patients by ROC-based Kaplan–Meier analyses.

Results

Expression of S100P and MACC1 correlated positively in CRC cells and colorectal tumours. MACC1 was found binding to the S100P promoter and induces its expression. The overexpression of S100P increased proliferation, migration and invasion in vitro and significantly induced liver metastasis in vivo. S100P expression was significantly elevated in metachronously metastasising CRC and was associated with shorter metastasis-free survival.

Conclusions

We identified S100P as a transcriptional target gene of MACC1. Expression of S100P increases the metastatic potential of CRC cells in vitro and in vivo, and serves as a prognostic biomarker for metastasis-free survival of CRC patients, emphasising novel therapeutic interventions targeting S100P.

Correlation of Immunological and Molecular Profiles with Response to Crizotinib in Alveolar Soft Part Sarcoma: An Exploratory Study Related to the EORTC 90101 "CREATE" Trial

Alveolar soft part sarcoma (ASPS) is a rare subtype of soft tissue sarcoma characterized by an unbalanced translocation, resulting in ASPSCR1-TFE3 fusion that transcriptionally upregulates MET expression. The European Organization for Research and Treatment of Cancer (EORTC) 90101 “CREATE” phase II trial evaluated the MET inhibitor crizotinib in ASPS patients, achieving only limited antitumor activity. We performed a comprehensive molecular analysis of ASPS tissue samples collected in this trial to identify potential biomarkers correlating with treatment outcome. A tissue microarray containing 47 ASPS cases was used for the characterization of the tumor microenvironment using multiplex immunofluorescence. DNA isolated from 34 available tumor samples was analyzed to detect recurrent gene copy number alterations (CNAs) and mutations by low-coverage whole-genome sequencing and whole-exome sequencing. Pathway enrichment analysis was used to identify diseased-associated pathways in ASPS sarcomagenesis. Kaplan–Meier estimates, Cox regression, and the Fisher’s exact test were used to correlate histopathological and molecular findings with clinical data related to crizotinib treatment, aiming to identify potential factors associated with patient outcome. Tumor microenvironment characterization showed the presence of PD-L1 and CTLA-4 in 10 and 2 tumors, respectively, and the absence of PD-1 in all specimens. Apart from CD68, other immunological markers were rarely expressed, suggesting a low level of tumor-infiltrating lymphocytes in ASPS. By CNA analysis, we detected a number of broad and focal alterations. The most common alteration was the loss of chromosomal region 1p36.32 in 44% of cases. The loss of chromosomal regions 1p36.32, 1p33, 1p22.2, and 8p was associated with shorter progression-free survival. Using whole-exome sequencing, 13 cancer-associated genes were found to be mutated in at least three cases. Pathway enrichment analysis identified genetic alterations in NOTCH signaling, chromatin organization, and SUMOylation pathways. NOTCH4 intracellular domain dysregulation was associated with poor outcome, while inactivation of the beta-catenin/TCF complex correlated with improved outcome in patients receiving crizotinib. ASPS is characterized by molecular heterogeneity. We identify genetic aberrations potentially predictive of treatment outcome during crizotinib therapy and provide additional insights into the biology of ASPS, paving the way to improve treatment approaches for this extremely rare malignancy.

Kolon adenokarsinomlarında ve adenomatöz poliplerinde Beta-Catenin ve Sox2 ekspresyonu ve klinikopatolojik parametreler ile ilişkileri

Objective: Our aim was to investigate the immunohistochemical expression of β-catenin and Sox-2 in adenomatous polyps and adenocarcinoma of colon and also to evaluate the effects of these markers in adenoma-carcinoma sequence and their association with clinicopathological parameters. Methods: Fifty-six tubular adenomas with low grade dysplasia (TALGD), 53 tubular adenomas with high grade dysplasia (TAHGD), 44 tubulovillous adenomas (TVA), 29 villous adenomas (VA) and 60 adenocarcinomas were included in the study. The nuclear staining of Sox2 was evaluated as well as both nuclear and cytoplasmic stainings of β-catenin. A semiquantitative scoring was performed. The results were compared between the groups and the relationship of the results with clinicopathological parameters was evaluated. Results: Nuclear and cytoplasmic β-catenin expressions of the adenocarcinomas were higher than polyps. The expressions in the VA and TVA polyp groups were higher than the expressions in TAHGD and TALGD, respectively. Membranous β-catenin expression in the adenocarcinoma was higher than the polyps except VA. The evaluation between polyp groups with respect to membranous β-catenin staining revealed a statistically significantly difference in favor of VA compared with TVA, TAHGD and TALGD; in favor of TAHGD compared with TVA, in favor of TVA compared with TALGD while it was found statistically significantly higher in TAHGD than TALGD. Conclusion: The results regarding β-catenin expression of the polyp groups were consistent with the literature. There was a positive correlation between β-catenin expression (nuclear and cytoplasmic) and malignancy. High Sox2 expressions were found correlated with malignancy potential. Large sampling size investigations to be supported by further molecular studies are needed to clarify the effect of Sox2 expression in the sequence of adenoma-carcinoma comprehensively.

Nek2 Kinase Signaling in Malaria, Bone, Immune and Kidney Disorders to Metastatic Cancers and Drug Resistance: Progress on Nek2 Inhibitor Development

Cell cycle kinases represent an important component of the cell machinery that controls signal transduction involved in cell proliferation, growth, and differentiation. Nek2 is a mitotic Ser/Thr kinase that localizes predominantly to centrosomes and kinetochores and orchestrates centrosome disjunction and faithful chromosomal segregation. Its activity is tightly regulated during the cell cycle with the help of other kinases and phosphatases and via proteasomal degradation. Increased levels of Nek2 kinase can promote centrosome amplification (CA), mitotic defects, chromosome instability (CIN), tumor growth, and cancer metastasis. While it remains a highly attractive target for the development of anti-cancer therapeutics, several new roles of the Nek2 enzyme have recently emerged: these include drug resistance, bone, ciliopathies, immune and kidney diseases, and parasitic diseases such as malaria. Therefore, Nek2 is at the interface of multiple cellular processes and can influence numerous cellular signaling networks. Herein, we provide a critical overview of Nek2 kinase biology and discuss the signaling roles it plays in both normal and diseased human physiology. While the majority of research efforts over the last two decades have focused on the roles of Nek2 kinase in tumor development and cancer metastasis, the signaling mechanisms involving the key players associated with several other notable human diseases are highlighted here. We summarize the efforts made so far to develop Nek2 inhibitory small molecules, illustrate their action modalities, and provide our opinion on the future of Nek2-targeted therapeutics. It is anticipated that the functional inhibition of Nek2 kinase will be a key strategy going forward in drug development, with applications across multiple human diseases.

Sodium salicylate and 5-aminosalicylic acid synergistically inhibit the growth of human colon cancer cells and mouse intestinal polyp-derived cells

As colon cancer is one of the most common cancers in the world, practical prevention strategies for colon cancer are needed. Recently, treatment with aspirin and/or 5-aminosalicylic acid-related agents was reported to reduce the number of intestinal polyps in patients with familial adenomatous polyposis. To evaluate the mechanism of aspirin and 5-aminosalicylic acid for suppressing the colon polyp growth, single and combined effects of 5-aminosalicylic acid and sodium salicylate (metabolite of aspirin) were tested in the two human colon cancer cells with different cyclooxygenase-2 expression levels and intestinal polyp-derived cells from familial adenomatous polyposis model mouse. The combination induced cell-cycle arrest at the G1 phase along with inhibition of cell growth and colony-forming ability in these cells. The combination reduced cyclin D1 via proteasomal degradation and activated retinoblastoma protein. The combination inhibited the colony-forming ability of mouse colonic mucosa cells by about 50% and the colony-forming ability of mouse intestinal polyp-derived cells by about 90%. The expression level of cyclin D1 in colon mucosa cells was lower than that in intestinal polyp-derived cells. These results suggest that this combination may be more effective in inhibiting cell growth of intestinal polyps through cyclin D1 down-regulation.

Cytotoxic Evaluation and Molecular Docking studies of Aminopyridine derivatives as Potential Anticancer Agents

BACKGROUND

The development of resistance to available anticancer drugs is increasingly becoming a major challenge and new chemical entities could be unveiled to compensate for this therapeutic failure.

OBJECTIVES

The current study demonstrated whether N-protected and deprotected amino acid derivatives of 2-aminopyridine could attenuate tumor development using colorectal cancer cell lines.

METHODS

Biological assays were performed to investigate the anticancer potential of synthesized compounds. The in silico ADME profiling and docking studies were also performed by docking the designed compounds against the active binding site of beta-catenin (CTNNB1) to analyze the binding mode of these compounds. Four derivatives 4a, 4b, 4c, and 4d were selected for investigation of in vitro anticancer potential using colorectal cancer cell line HCT 116. The anti-tumor activities of synthesized compounds were further validated by evaluating the inhibitory effects of these compounds on the target protein beta-catenin through in vitro enzyme inhibitory assay.

RESULTS

The docking analysis revealed favorable binding energies and interactions with the target proteins. The in vitro MTT assay on colorectal cancer cell line HCT 116 and HT29 revealed potential anti-tumor activities with an IC50 range of 3.7-8.1µM and 3.27-7.7 µM, respectively. The inhibitory properties of these compounds on the concentration of beta-catenin by ELISA revealed significant percent inhibition of target protein at 100 µg/ml.

CONCLUSION

In conclusion, the synthesized compounds showed significant anti-tumor activities both in silico and in vitro, having potential for further investigating its role in colorectal cancer.

Tumor Endothelial Marker 8 Promotes Proliferation and Metastasis via the Wnt/β-Catenin Signaling Pathway in Lung Adenocarcinoma

Tumor endothelial marker 8 (TEM8), also known as ANTXR1, was highly expressed in cancers, and was identified as a biomarker for early diagnosis and prognosis in some cancers. However, the clinical role and molecular mechanisms of TEM8 in lung adenocarcinoma (LUAD) are still unclear. The present study aimed to explore its clinical value and the molecular mechanisms of TEM8 underlying the progression of LUAD. Our study found the elevation of TEM8 in LUAD cell lines and tissues. What’s more, we observed that the TEM8 expression level was associated with tumor size, primary tumor, and AJCC stage, and LUAD patients with high TEM8 expression usually have a poor prognosis. Then, we conducted a series of experiments by the strategy of loss-of-function and gain-of-function, and our results suggested that the knockdown of TEM8 suppressed proliferation, migration, and invasion and induced apoptosis in LUAD whereas overexpression of TEM8 had the opposite effect. Molecular mechanistic investigation showed that TEM8 exerted its promoting effects mainly through activating the Wnt/β-catenin signaling pathway. In short, our findings suggested that TEM8 played a crucial role in the progression of LUAD by activating the Wnt/β-catenin signaling pathway and could serve as a potential therapeutic target for LUAD.

Clinical Importance of Wnt5a in the Pathogenesis of Colorectal Cancer

Wnt5a is one of the potent signaling molecules that initiates responses involved in cancer through activation of both canonical and noncanonical signaling cascades. Wnt5a both directly and indirectly triggers cancer-associated signaling pathways based on the cancer type. In colorectal cancer (CRC), altering Wnt5a expression can influence several cellular processes of tumor cells, including proliferation, differentiation, migration, invasion, and metastasis. This review summarizes the molecular mechanisms and clinical importance of Wnt5a in the pathogenesis of CRC for better understanding the pathogenesis and its potential role as a prognostic marker and as an appropriate therapeutic target in the treatment of this disease in the future.

Gαs-Protein Kinase A (PKA) Pathway Signalopathies: The Emerging Genetic Landscape and Therapeutic Potential of Human Diseases Driven by Aberrant Gαs-PKA Signaling

Many of the fundamental concepts of signal transduction and kinase activity are attributed to the discovery and crystallization of cAMP-dependent protein kinase, or protein kinase A. PKA is one of the best-studied kinases in human biology, with emphasis in biochemistry and biophysics, all the way to metabolism, hormone action, and gene expression regulation. It is surprising, however, that our understanding of PKA's role in disease is largely underappreciated. Although genetic mutations in the PKA holoenzyme are known to cause diseases such as Carney complex, Cushing syndrome, and acrodysostosis, the story largely stops there. With the recent explosion of genomic medicine, we can finally appreciate the broader role of the Gαs-PKA pathway in disease, with contributions from aberrant functioning G proteins and G protein-coupled receptors, as well as multiple alterations in other pathway components and negative regulators. Together, these represent a broad family of diseases we term the Gαs-PKA pathway signalopathies. The Gαs-PKA pathway signalopathies encompass diseases caused by germline, postzygotic, and somatic mutations in the Gαs-PKA pathway, with largely endocrine and neoplastic phenotypes. Here, we present a signaling-centric review of Gαs-PKA-driven pathophysiology and integrate computational and structural analysis to identify mutational themes commonly exploited by the Gαs-PKA pathway signalopathies. Major mutational themes include hotspot activating mutations in Gαs, encoded by GNAS, and mutations that destabilize the PKA holoenzyme. With this review, we hope to incite further study and ultimately the development of new therapeutic strategies in the treatment of a wide range of human diseases. SIGNIFICANCE STATEMENT: Little recognition is given to the causative role of Gαs-PKA pathway dysregulation in disease, with effects ranging from infectious disease, endocrine syndromes, and many cancers, yet these disparate diseases can all be understood by common genetic themes and biochemical signaling connections. By highlighting these common pathogenic mechanisms and bridging multiple disciplines, important progress can be made toward therapeutic advances in treating Gαs-PKA pathway-driven disease.

Suppression of Colon Tumorigenesis in Mutant Apc Mice by a Novel PDE10 Inhibitor that Reduces Oncogenic β-Catenin

Previous studies have reported that phosphodiesterase 10A (PDE10) is overexpressed in colon epithelium during early stages of colon tumorigenesis and essential for colon cancer cell growth. Here we describe a novel non-COX inhibitory derivative of the anti-inflammatory drug, sulindac, with selective PDE10 inhibitory activity, ADT 061. ADT 061 potently inhibited the growth of colon cancer cells expressing high levels of PDE10, but not normal colonocytes that do not express PDE10. The concentration range by which ADT 061 inhibited colon cancer cell growth was identical to concentrations that inhibit recombinant PDE10. ADT 061 inhibited PDE10 by a competitive mechanism and did not affect the activity of other PDE isozymes at concentrations that inhibit colon cancer cell growth. Treatment of colon cancer cells with ADT 061 activated cGMP/PKG signaling, induced phosphorylation of oncogenic β-catenin, inhibited Wnt-induced nuclear translocation of β-catenin, and suppressed TCF/LEF transcription at concentrations that inhibit cancer cell growth. Oral administration of ADT 061 resulted in high concentrations in the colon mucosa and significantly suppressed the formation of colon adenomas in the Apc^+/min-FCCC mouse model of colorectal cancer without discernable toxicity. These results support the development of ADT 061 for the treatment or prevention of adenomas in individuals at risk of developing colorectal cancer. PREVENTION RELEVANCE: PDE10 is overexpressed in colon tumors whereby inhibition activates cGMP/PKG signaling and suppresses Wnt/β-catenin transcription to selectively induce apoptosis of colon cancer cells. ADT 061 is a novel PDE10 inhibitor that shows promising cancer chemopreventive activity and tolerance in a mouse model of colon cancer.

LncRNA TP73-AS1 promotes the development of Epstein-Barr virus associated gastric cancer by recruiting PRC2 complex to regulate WIF1 methylation

BACKGROUND

Epstein-Barr virus associated gastric cancer (EBVaGC) become a growing health problem. TP73-AS1 showed high expression in EBVaGC cells. However, the function role and underlying mechanism of TP73-AS1 need further exploration.

METHODS

The expressions of TP73-AS1, WIF1, EZH2, β-catenin and epithelial-mesenchymal transition (EMT)-related proteins were detected using qRT-PCR and Western blotting. Cell proliferation, apoptosis, migration and invasion were measured by CCK-8, colony formation, flow cytometry, wound healing and transwell assays, respectively. WIF1 promoter methylation was analyzed by MS-PCR (MSP). RNA immunoprecipitation assay (RIP) and Chromatin immunoprecipitation assay (ChIP) measured the interactions of TP73-AS1/EZH2 and EZH2/WIF1. Subcutaneous tumor growth was monitored in nude mice and immunohistochemistry (IHC) detected proliferation marker Ki-67 expression.

RESULTS

TP73-AS1 was increased while WIF1 was decreased in EBVaGC cells. Silencing of TP73-AS1 or overexpression of WIF1 repressed the growth and migration while promoted apoptosis of EBVaGC cells. Knockdown of WIF1 reversed the anticancer effect of TP73-AS1 silencing. TP73-AS1 promoted the binding of EZH2 to the WIF1 promoter by directly binding to EZH2, and thus inhibiting the expression of WIF1 by enhancing H3K27me3 level of WIF1 promoter. Moreover, TP73-AS1 activated Wnt/β-catenin signaling pathway and promoted EMT by down-regulating WIF1. TP73-AS1 silencing inhibited the progression of EBVaGC in nude mice by epigenetically regulating WIF1.

CONCLUSION

TP73-AS1 regulated the promoter methylation of WIF1 by recruiting PRC2 complex to WIF1 promoter region, thereby promoting the progression of EBVaGC. These observations provided a novel theoretical basis to investigate more effective therapies of EBVaGC.

Downregulating circRNA_0044516 Inhibits Cell Proliferation in Gastric Cancer Through miR-149/Wnt1/β-catenin Pathway

BACKGROUND

Circular RNAs (circRNAs) play important roles in the progression of gastric cancer (GC). The Wnt1/β-catenin pathway can promote the proliferation of GC cells. This study aimed to explore whether circRNA_0044516 can regulate the proliferation of GC cells by modulating the Wnt1/β-catenin pathway.

METHODS

The expression of circRNA_0044516, miR-149, Wnt1, and β-catenin in GC tissues or cells was detected by qRT-PCR and western blot. Cell viability and apoptosis were measured by CCK-8 and flow cytometry assays, respectively. The interaction between circRNA_0044516 and miR-149 was determined by luciferase reporter and RNA pull-down assays.

RESULTS

Upregulated circRNA_0044516 was found in GC tissues and cell lines. Downregulating circRNA_0044516 inhibited the viability and promoted apoptosis of GC cells. CircRNA_0044516 targeted miR-149, and its downregulation elevated miR-149 level in GC cells. Mechanistically, silencing circRNA_0044516 reduced the protein level of Wnt1 and β-catenin through miR-149, and finally suppressed viability and contributed to apoptosis of GC cells. Moreover, circRNA_0044516 knockdown inhibited the tumor growth of HGC-27 cells in nude mice.

CONCLUSIONS

Our results indicated an important role of circRNA_0044516 in GC and elucidated that downregulation of circRNA_0044516 inhibits the proliferation of GC cells through miR-149/Wnt1/β-catenin.

Dihydrocapsaicin Inhibits Cell Proliferation and Metastasis in Melanoma via Down-regulating β-Catenin Pathway

Dihydrocapsaicin (DHC) is one of the main components of capsaicinoids in Capsicum. It has been reported that DHC exerts anti-cancer effects on diverse malignant tumors, such as colorectal cancer, breast cancer, and glioma. However, studies focused on the effect of DHC upon melanoma have rarely been done. In the present study, melanoma A375 and MV3 cell lines were treated with DHC and the cell proliferation, migration, and invasion were significantly suppressed. Furthermore, DHC effectively inhibited xenograft tumor growth and pulmonary metastasis of melanoma cells in NOD/SCID mice model. It was identified that β-catenin, which plays significant roles in cell proliferation and epithelial-mesenchymal transition, was down-regulated after DHC treatment. In addition, cyclin D1, c-Myc, MMP2, and MMP7, which are critical in diverse cellular process regulation as downstream proteins of β-catenin, were all decreased. Mechanistically, DHC accelerates ubiquitination of β-catenin and up-regulates the beta-transducin repeat containing E3 ubiquitin protein ligase (BTRC) in melanoma cells. The DHC induced suppression of cell proliferation, migration, and invasion were partly rescued by exogenous β-catenin overexpression, both in vitro and in vivo. Taken together, DHC may serve as a candidate natural compound for human melanoma treatment through β-catenin pathway.

Colon Cancer Risk of a Westernized Diet Is Reduced in Mice by Feeding Cruciferous or Apiaceous Vegetables at a Lower Dose of Carcinogen but Not a Higher Dose

Western-style diets (WD) are associated with greater risk of colon cancer. Exposure to 2-amino-1-methyl-6-phenylimidazo(4,5-b)pyridine (PhIP), a food-borne carcinogen, is linked to increased colon cancer risk. In contrast, intake of apiaceous and cruciferous vegetables (APIs and CRUs) is associated with reduced risk. Here we evaluated effects of a WD alone or a WD containing API or CRU, relative to a purified diet (basal), on colon cancer risk in mice. All diets were fed at one of two concentrations of PhIP (100 or 400 ppm). The activity of the hepatic PhIP-activating enzyme, cytochrome P450 (CYP) 1A2, was examined at week 4 and colonic precancerous lesions (aberrant crypt foci, ACF) were enumerated at week 12. In low PhIP-fed groups, CYP1A2 activity was greater for CRU than all other groups, which did not differ from one another. WD had a significantly greater effect on the formation of ACF than the basal diet. In groups fed API or CRU, the ACF number was reduced to the level observed in the basal diet-fed group. In high PhIP-fed groups, all WD-based diets had greater CYP1A2 activity than the basal diet-fed group. Surprisingly, the basal diet group had more ACF than the WD group, and API and CRU groups did not differ from the WD alone group. Thus, at the lower dose of PhIP, the WD increased colon cancer risk in mice, compared to a purified diet, and APIs and CRUs reduced the risk of the WD. However, at the higher dose of PhIP, the enhancement of colon cancer risk by the WD was not evident, nor was the chemopreventive effect of these vegetables.

Nuclear β-catenin expression is positively regulated by JAB1 in human colorectal cancer cells

Wnt/β-catenin signaling is important for development and progression of colorectal cancer (CRC). The degradation complex for β-catenin is functionally impaired in CRC cells, thereby resulting in the accumulation of β-catenin and its translocation into the nucleus. Nuclear β-catenin interacts with and co-activates T cell factor4 (TCF4), resulting in β-catenin/TCF4-dependent transcription. Therefore, nuclear β-catenin has been categorized as the main driving force in the tumorigenesis of CRC. Recent studies reveal that Jun activation domain-binding protein 1 (JAB1) enhances the degradation of seven in absentia homolog-1 (SIAH-1), a putative E3 ubiquitin ligase of β-catenin, and positively regulates the expression of total β-catenin in human CRC cells. An another recent study also shows that nuclear β-catenin is ubiquitinated and degraded by an E3 ubiquitin ligase, tripartite motif-containing protein 33 (TRIM33). However, the regulatory mechanism for the expression of nuclear β-catenin remains to be fully understood. In this study, we have demonstrated that JAB1 positively regulates the expression of nuclear β-catenin, c-MYC as a β-catenin/TCF4 target, and cell cycle regulators, such as Ki-67 and topoisomerase IIα, in human CRC cells. Taken together, these results suggest that JAB1 is considered as a promising target for novel CRC therapy.

Oncogenic roles of lncRNA BLACAT1 and its related mechanisms in human cancers

Long non-coding RNAs (lncRNAs) play indispensable roles in mediating regulation of epigenetics, and their dysregulation is strongly associated with the initiation and progression of human cancers. Recently, lncRNA bladder cancer-associated transcript 1 (BLACAT1) has been observed to exert oncogenic effects on cancers, including glioma, breast cancer, lung cancer, hepatocellular carcinoma, gastric cancer, colorectal cancer, ovarian cancer, cervical cancer and osteosarcoma. Additional mechanical analyses have uncovered that lncRNA BLACAT1 is positively correlated with tumor stage, lymph node metastasis and distant metastasis of primary tumors via involvement with various cellular activities, thus leading to poor overall survival and progression-free survival (PFS). In this review, we generalize the oncogenic roles of BLACAT1 in multiple human cancers through correlation with clinical implications and cellular activities. Moreover, we forecast its potential clinical application as a novel biomarker and a promising therapeutic target for cancers.

The Ubiquitin Gene Expression Pattern and Sensitivity to UBB and UBC Knockdown Differentiate Primary 23132/87 and Metastatic MKN45 Gastric Cancer Cells

Gastric cancer (GC) is one of the most common and lethal cancers. Alterations in the ubiquitin (Ub) system play key roles in the carcinogenetic process and in metastasis development. Overexpression of transcription factors YY1, HSF1 and SP1, known to regulate Ub gene expression, is a predictor of poor prognosis and shorter survival in several cancers. In this study, we compared a primary (23132/87) and a metastatic (MKN45) GC cell line. We found a statistically significant higher expression of three out of four Ub coding genes, UBC, UBB and RPS27A, in MKN45 compared to 23132/87. However, while the total Ub protein content and the distribution of Ub between the conjugated and free pools were similar in these two GC cell lines, the proteasome activity was higher in MKN45. Ub gene expression was not affected upon YY1, HSF1 or SP1 small interfering RNA (siRNA) transfection, in both 23132/87 and MKN45 cell lines. Interestingly, the simultaneous knockdown of UBB and UBC mRNAs reduced the Ub content in both cell lines, but was more critical in the primary GC cell line 23132/87, causing a reduction in cell viability due to apoptosis induction and a decrease in the oncoprotein and metastatization marker β-catenin levels. Our results identify UBB and UBC as pro-survival genes in primary gastric adenocarcinoma 23132/87 cells.

The Relevance of Transcription Factors in Gastric and Colorectal Cancer Stem Cells Identification and Eradication

Gastric and colorectal cancers have a high incidence and mortality worldwide. The presence of cancer stem cells (CSCs) within the tumor mass has been indicated as the main reason for tumor relapse, metastasis and therapy resistance, leading to poor overall survival. Thus, the elimination of CSCs became a crucial goal for cancer treatment. The identification of these cells has been performed by using cell-surface markers, a reliable approach, however it lacks specificity and usually differs among tumor type and in some cases even within the same type. In theory, the ideal CSC markers are those that are required to maintain their stemness features. The knowledge that CSCs exhibit characteristics comparable to normal stem cells that could be associated with the expression of similar transcription factors (TFs) including SOX2, OCT4, NANOG, KLF4 and c-Myc, and signaling pathways such as the Wnt/β-catenin, Hedgehog (Hh), Notch and PI3K/AKT/mTOR directed the attention to the use of these similarities to identify and target CSCs in different tumor types. Several studies have demonstrated that the abnormal expression of some TFs and the dysregulation of signaling pathways are associated with tumorigenesis and CSC phenotype. The disclosure of common and appropriate biomarkers for CSCs will provide an incredible tool for cancer prognosis and treatment. Therefore, this review aims to gather the new insights in gastric and colorectal CSC identification specially by using TFs as biomarkers and divulge promising drugs that have been found and tested for targeting these cells.

Upregulation of ARHGAP30 attenuates pancreatic cancer progression by inactivating the β-catenin pathway

Background

Pancreatic cancer is a highly malignant gastrointestinal cancer that can widely metastasize during the early stage of disease, and it is associated with one of the worst prognoses among cancers. In this study, we aimed to investigate the function of Rho GTPase-activating protein 30 (ARHGAP30) in pancreatic cancer cells and thus propose a novel therapy for pancreatic cancer.

Methods

ARHGAP30 expression in tumor tissues from patients with pancreatic cancer as well as cell lines was detected using immunohistochemistry (IHC), real-time polymerase chain reaction, and western blotting. Cell proliferation, transwell, and apoptosis assays were performed and the levels of related proteins were determined after ARHGAP30 knockdown or overexpression. Additionally, in vivo experiments were performed on nude mice.

Results

ARHGAP30 expression was found to be significantly increased in tumor tissues from patients with pancreatic cancer as well as in pancreatic cancer cell lines. IHC and prognostic analyses indicated that patients with high ARHGAP30 expression had a good prognosis. ARHGAP30 overexpression significantly decreased pancreatic cancer cell proliferation and metastasis; promoted apoptosis; reduced β-catenin, B-cell lymphoma 2 (Bcl-2), matrix metalloproteinase-2 (MMP2), and MMP9 expression; and increased Bcl-2-associated X protein (Bax) and cleaved caspase-3 expression. ARHGAP30 knockdown elicited the opposite effects. The effects of ARHGAP30 knockdown were potently attenuated by the β-catenin inhibitor XAV939. ARHGAP30 knockdown-induced RHOA activity was potently attenuated by the RHOA inhibitor CCG1423. In vivo, ARHGAP30 overexpression significantly inhibited lung metastasis in nude mice and increased the survival of mice with lung metastases.

Conclusions

Our findings indicate that ARHGAP30 may function as a tumor suppressor in pancreatic cancer progression by regulating the expression of related genes and the β-catenin pathway.

Pharmacogenomics of 5-fluorouracil in colorectal cancer: review and update

BACKGROUND

Colorectal cancer (CRC) is a disease with high morbidity and mortality rates. 5-fluorouracil (5-FU) is the first-line recommended drug for chemotherapy in patients with CRC, and it has a good effect on a variety of other solid tumors as well. Unfortunately, however, due to the emergence of drug resistance the effectiveness of treatment may be greatly reduced. In the past decade, major progress has been made in the field of 5-FU drug resistance in terms of molecular mechanisms, pre-clinical (animal) models and clinical trials.

CONCLUSIONS

In this article we systematically review and update current knowledge on 5-FU pharmacogenomics related to drug uptake and activation, the expression and activity of target enzymes (DPD, TS and MTHFR) and key signaling pathways in CRC. Furthermore, a summary of drug combination strategies aimed at targeting specific genes and/or pathways to reverse 5-FU resistance is provided. Based on this, we suggest that causal relationships between genes, pathways and drug sensitivity should be systematically considered from a multidimensional perspective. In the design of research methods, emerging technologies such as CRISPR-Cas, TALENS and patient-derived xenograft models should be applied as far as possible to improve the accuracy of clinically relevant results.

Study of Dickkopf-1 (DKK-1) in patients with chronic viral hepatitis C-related liver cirrhosis with and without hepatocellular carcinoma

Aim of the study

Dickkopf-1 (DKK-1) is a secreted protein which acts as an inhibitor of Wnt/β-catenin signaling. DKK-1 was found to be a helpful biomarker for many cancers including hepatocellular carcinoma (HCC). HCC is multifactorial in origin and its main etiology in Egypt is attributed to chronic hepatitis C virus (HCV) infection. Objectives: To assess the serum level and diagnostic performance of DKK-1 and α-fetoprotein (AFP) in Egyptian patients with chronic HCV-related liver cirrhosis with and without HCC.

Material and methods

80 subjects were divided into: a control group (group I, 20 healthy volunteers) and two patient groups: group II (HCV with liver cirrhosis, 30 patients), and group III, (HCV-related liver cirrhosis with HCC, 30 patients). Thorough physical examination, triphasic computed tomography, calculation of Child-Pugh score, laboratory investigations (complete blood picture, liver profile, hepatitis B surface antigen, anti-HCV antibodies, AFP (chemiluminometry) and DKK-1 (ELISA) were performed.

Results

There was a significant decrease in DKK-1 level in HCV patients with liver cirrhosis (group II) and HCV patients with HCC (group III) compared to the control group (group I) (p < 0.001). However, there was a significant increase in DKK-1 level in HCV patients with HCC (group III) compared to HCV patients with liver cirrhosis (group II) (p < 0.033). The ROC curve showed that DKK-1 has less sensitivity but higher specificity in HCV patients with HCC (group III) compared with HCV patients with liver cirrhosis (group II).

Conclusions

The combination of DKK-1 and AFP could further improve the diagnostic accuracy of HCV-related cirrhosis with or without HCC.

Galectin-3 diminishes Wnt signaling in the postnatal subventricular zone

Postnatal subventricular zone (pSVZ) stem and progenitor cell proliferation is regulated by several developmental signaling pathways such as Wnt/β-catenin. However, the molecular regulation of Wnt function in the pSVZ is poorly understood. We previously showed that Wnt signaling is upregulated in an SVZ gliomagenesis in vivo model. As well, the pro-inflammatory molecule Galectin-3 (Gal-3) increases Wnt signaling in cancer cells and is expressed in the SVZ. Therefore, we asked if Gal-3 has a similar function on Wnt signaling in the pSVZ. We interrogated Wnt signaling using a signaling reporter as well as immunohistochemistry and showed that Wnt signaling predominates upstream in the pSVZ lineage but is downregulated in migrating neuroblasts. Biochemical analysis of SVZ cells, in vivo and in neurosphere stem/progenitor cells, showed that Gal-3 physically interacts with multiple forms of β-catenin, which is a major downstream regulator of Wnt signaling. Functional analyses demonstrated, in vitro and in vivo, that Gal-3 knockdown increases Wnt signaling and conversely that Gal-3 OE inhibits Wnt/β-catenin signaling in the pSVZ. This latter result suggested that Gal-3, which is consistently increased in brain injury, may decrease pSVZ proliferation. We showed that Gal-3 OE decreased proliferation without altering cell cycle re-entry and that it increased p27Kip1, a molecule which induces cell cycle exit. Our data uncover a novel regulator of Wnt signaling in the SVZ, Gal-3, which does so in a manner opposite to cancer.

Effects of Environmental pH on the Growth of Gastric Cancer Cells

Background

Proton pump inhibitor (PPI) and other acid-suppressing drugs are widely used in the treatment of gastrointestinal ulcer, upper gastrointestinal bleeding, gastritis, and gastric cancer (GC). About 80% of GC patients receive acid suppression treatment. PPI suppresses the production of gastric acid by inhibiting the function of H⁺/K⁺-ATPase in gastric parietal cells and raises the pH value to achieve therapeutic purposes. Some studies have found that PPI had a certain antitumor effect in the proliferation and apoptosis of tumor cells. But the effects of environmental pH on the growth of GC cells and its mechanism are unknown. Therefore, we hoped to find the effects of culture medium pH on the biological behavior of GC cells by in vitro experiments and provide guidance for the use of acid-suppressing drugs in GC patients.

Aims

We aimed to observe the effects of pH changes in GC cell culture medium on the cell biological behavior of cancer cells and to analyze the potential mechanisms. We hoped to find out the effect of acid suppression on the growth of GC cells.

Methods

The GC cell lines (SGC-7901 and MKN45) were used as the research object. We adjusted the pH value in the cell culture medium to observe the changes in cell viability (MTT), apoptosis (flow cytometry), and invasion (Transwell) at pH 6, pH 7, and pH 8. qRT-PCR and western blot (WB) assays were used to determine the expression changes of genes and proteins (mTOR, AKT, Wnt, Glut, and HIF-1α) at pH 6, pH 7, and pH 8.

Results

The results of MTT showed that the viability of SGC-7901 and MKN45 in the pH 8.0 group was significantly weaker than that in the pH 6.0 or pH 7.0 group (P < 0.001). Flow cytometry results showed that the apoptosis of SGC-7901 and MKN45 in the pH 8.0 group was more obvious than that in the pH 6.0 or pH 7.0 group (P < 0.001). Flow cytometry results showed that the apoptosis of SGC-7901 and MKN45 in the pH 8.0 group was more obvious than that in the pH 6.0 or pH 7.0 group (P < 0.001). Flow cytometry results showed that the apoptosis of SGC-7901 and MKN45 in the pH 8.0 group was more obvious than that in the pH 6.0 or pH 7.0 group (α) at pH 6, pH 7, and pH 8. P < 0.001). Flow cytometry results showed that the apoptosis of SGC-7901 and MKN45 in the pH 8.0 group was more obvious than that in the pH 6.0 or pH 7.0 group (

Conclusions

Compared with the microacid environment, the microalkaline environment inhibited the viability, invasion, and expression of genes and proteins (mTOR, AKT, Wnt, Glut, and HIF-1α) but promoted the apoptosis of GC cells and thus inhibited the growth of GC.α) at pH 6, pH 7, and pH 8.

Cas9 Mediated Correction of β-catenin Mutation and Restoring the Expression of Protein Phosphorylation in Colon Cancer HCT-116 Cells Decrease Cell Proliferation in vitro and Hamper Tumor Growth in Mice in vivo

Purpose

Colorectal cancer (CRC) is one of the major contributors to cancer mortality and morbidity. Finding strategies to fight against CRC is urgently required. Mutations in driver genes of  APC or β-catenin play an important role in the occurrence and progression of CRC. In the present study, we jointly apply CRISPR/Cas9-sgRNA system and Single-stranded oligodeoxynucleotide (ssODN) as templates to correct a heterozygous ΔTCT deletion mutation of β-catenin present in a colon cancer cell line HCT-116. This method provides a potential strategy in gene therapy for cancer.

Methods

A Cas9/β-catenin-sgRNA-eGFP co-expression vector was constructed and co-transfected with ssODN into HCT-116 cells. Mutation-corrected single-cell clones were sorted by FACS and judged by TA cloning and DNA sequencing. Effects of CRISPR/Cas9-mediated correction were tested by real-time quantitative PCR, Western blotting, CCK8, EDU dyeing and cell-plated clones. Moreover, the growth of cell clones derived tumors was analyzed at nude mice xenografts.

Results

CRISPR/Cas9-mediated β-catenin mutation correction resulted in the presence of TCT sequence and the re-expression of phosphorylation β-catenin at Ser45, which restored the normal function of phosphorylation β-catenin including reduction of the transportation of nuclear β-catenin and the expression of downstream c-myc, survivin. Significantly reduced cell growth was observed in β-catenin mutation-corrected cells. Mice xenografted with mutation-corrected HCT-116 cells showed significantly smaller tumor size than uncorrected xenografts.

Conclusion

The data of this study documented that correction of the driven mutation by the combination of CRISPR/Cas9 and ssODN could greatly remedy the biological behavior of the cancer cell line, suggesting a potential application of this strategy in gene therapy of cancer.

Honokiol: A Review of Its Anticancer Potential and Mechanisms

Cancer is characterised by uncontrolled cell division and abnormal cell growth, which is largely caused by a variety of gene mutations. There are continuous efforts being made to develop effective cancer treatments as resistance to current anticancer drugs has been on the rise. Natural products represent a promising source in the search for anticancer treatments as they possess unique chemical structures and combinations of compounds that may be effective against cancer with a minimal toxicity profile or few side effects compared to standard anticancer therapy. Extensive research on natural products has shown that bioactive natural compounds target multiple cellular processes and pathways involved in cancer progression. In this review, we discuss honokiol, a plant bioactive compound that originates mainly from the Magnolia species. Various studies have proven that honokiol exerts broad-range anticancer activity in vitro and in vivo by regulating numerous signalling pathways. These include induction of G0/G1 and G2/M cell cycle arrest (via the regulation of cyclin-dependent kinase (CDK) and cyclin proteins), epithelial-mesenchymal transition inhibition via the downregulation of mesenchymal markers and upregulation of epithelial markers. Additionally, honokiol possesses the capability to supress cell migration and invasion via the downregulation of several matrix-metalloproteinases (activation of 5' AMP-activated protein kinase (AMPK) and KISS1/KISS1R signalling), inhibiting cell migration, invasion, and metastasis, as well as inducing anti-angiogenesis activity (via the down-regulation of vascular endothelial growth factor (VEGFR) and vascular endothelial growth factor (VEGF)). Combining these studies provides significant insights for the potential of honokiol to be a promising candidate natural compound for chemoprevention and treatment.

XRCC4, which is inhibited by PFDA, regulates DNA damage repair and cell chemosensitivity

The mechanism of environmental pollution promoting gastric cancer incidence and difficulty of treatment is not fully understood. In the present article, perfluorodecanoic acid (PFDA), a common persistent environmental pollutant, was used to treat the gastric cell lines and mice to test its genotoxicity. The γ-H2AX immunoblot and plasmid fragment PCR results showed that PFDA had a promotion effect on the DNA double-strand breaks (DSBs) in human and mouse cells. Subsequent results showed that PFDA significantly altered the sensitivity of cells to chemotherapy. Microarray data showed that the expressions of some important DNA repair genes were changed. Further investigation discovered that PFDA inhibition of DNA repair was mediated by X-ray repair cross complementing 4 (XRCC4). The cells deficient in XRCC4 generally exhibited reduced proliferation and premature aging in culture; however, our results indicated that PFDA induced p53 inhibition rescued cells from the apoptosis that was triggered by nonhomologous end-joining (NHEJ) inactivation, and overexpression of p53 expression in PFDA-treated cells enhanced their apoptosis. Finally, T-cell specific factor 4 was suggested by the results as an upstream regulator of XRCC4. This article revealed for the first time that perfluorinated chemicals affect chemotherapeutic sensitivity and the NHEJ pathway, and p53 reduction rescues cells from death.

Breast cancer risk in neurofibromatosis type 1 is a function of the type of NF1 gene mutation: a new genotype-phenotype correlation

Background

Neurofibromatosis type 1 (NF1) predisposes to breast cancer (BC), but no genotype-phenotype correlations have been described.

Methods

Constitutional NF1 mutations in 78 patients with NF1 with BC (NF1-BC) were compared with the NF1 Leiden Open Variation Database (n=3432).

Results

No cases were observed with whole or partial gene deletions (HR 0.10; 95% CI 0.006 to 1.63; p=0.014, Fisher’s exact test). There were no gross relationships with mutation position. Forty-five (64.3%; HR 6.4–83) of the 70 different mutations were more frequent than expected (p<0.05), while 52 (74.3%; HR 5.3–83) were significant when adjusted for multiple comparisons (adjusted p≤0.125; Benjamini-Hochberg). Higher proportions of both nonsense and missense mutations were also observed (adjusted p=0.254; Benjamini-Hochberg). Ten of the 11 missense cases with known age of BC occurred at <50 years (p=0.041). Eighteen cases had BRCA1/2 testing, revealing one BRCA2 mutation.

Discussion

These data strongly support the hypothesis that certain constitutional mutation types, and indeed certain specific variants in NF1 confer different risks of BC. The lack of large deletions and excess of nonsenses and missenses is consistent with gain of function mutations conferring risk of BC, and also that neurofibromin may function as a dimer. The observation that somatic NF1 amplification can occur independently of ERBB2 amplification in sporadic BC supports this concept. A prospective clinical-molecular study of NF1-BC needs to be established to confirm and build on these findings, but regardless of NF1 mutation status patients with NF1-BC warrant testing of other BC-predisposing genes.

Overexpressed PLAGL2 transcriptionally activates Wnt6 and promotes cancer development in colorectal cancer

Researchers hold the view that PLAGL2 is overexpressed in many malignancies and that it can promote tumor proliferation, migration, invasion and self-renewal; however, there is no evidence revealing a relationship between PLAGL2 and colorectal cancer (CRC). In the present study, genes that are overexpressed in CRC were screened using the COSMIC database and GEPIA database and the expression of PLAGL2 in carcinoma tissues and pericarcinomatous tissues was detected by RT-qPCR and western blot assays. A Cell Counting Kit-8 assay, a cell cycle analysis experiment and a xenograft model were used to explore the influence of PLAGL2 on CRC after knocking down PLAGL2 expression in HCT116 and SW480 cells. Using ChIP assays and Dual-Luciferase Reporter assays, the promoter regions to which PLAGL2 binds were discovered. It was observed that PLAGL2 was overexpressed in colorectal cancer and that it influenced the colorectal cancer cell cycle and promoted colorectal cancer proliferation in vivo and in vitro. The expression of some genes in the Wnt/β-catenin pathway, were downregulated after knocking down the expression of PLAGL2; Wnt6 was altered the most. PLAGL2 could bind to the promoter region of Wnt6 and promote its expression. These results indicated that PLAGL2 was overexpressed in CRC as a proto-oncogene and that it could active the Wnt/β-catenin pathway as a transcription factor by binding with the promoter region of Wnt6. PALGL2 was revealed to play an important role in colorectal cancer and may be a new therapeutic target for targeted medicine.

Overexpression of FOXS1 in gastric cancer cell lines inhibits proliferation, metastasis, and epithelial-mesenchymal transition of tumor through downregulating wnt/β-catenin pathway

BACKGROUND

Expression of forkhead box (FOX) superfamily members has been shown to be decreased in cancer, which was linked to poor prognosis of patients. The aim of this study was to investigate the expression of a new FOX superfamily member, FOXS1, in gastric cancer, and the influence of FOXS1 overexpression on the tumorigenesis of gastric cancer cells. The underlying molecular mechanism was also investigated.

MATERIALS AND METHODS

FOXS1 expression levels were firstly measured in 15 paired gastric cancer and peritumor tissue using quantitative polymerase chain reaction or immunohistochemistry. Secondly, FOXS1 overexpression models were established in two gastric cancer cell lines (SNU-216 and AGS) and FOXS1 knockdown model was established in SNU-638 gastric cancer cell line. Markers for cell proliferation, metastasis, cell cycle status, and wnt/β-catenin pathway were evaluated. Influence of FOXS1 overexpression on tumorigenesis was further evaluated in xenograft model.

RESULTS

Expression of FOXS1 was significantly decreased in gastric cancer tissue in both messenger RNA and protein levels, compared with peritumor tissue. Our results showed that compared to cell lines transfected with negative control, gastric cancer cell lines with FOXS1 overexpression showed suppressed cell proliferation, metastasis, and increased ratio of G0/G1 phase. Xenograft model also showed suppressed tumor growth in FOXS1 overexpression group. Epithelial-mesenchymal transition was also inhibited when FOXS1 was overexpressed, which was indicated by an increase of E-cadherin expression and decrease in vimentin expression. Further investigation showed that expression of β-catenin was decreased, together with decreased expression in downstream signaling factors, c-Myc and cyclin-D1 in FOXS1 overexpression cell lines. On the other hand, knockdown of FOXS1 showed opposite trends in the changes of those markers for cell proliferation, metastasis, cell cycle status, and wnt/β-catenin pathway, compared with FOXS1 overexpression.

CONCLUSION

In conclusion, the present study showed that FOXS1 expression is downregulated in most GC cases in our cohort, and this loss of expression may promote cell proliferation and metastasis through upregulation of wnt/β-catenin pathway.

Lupeol inhibits growth and migration in two human colorectal cancer cell lines by suppression of Wnt-β-catenin pathway

Background

Lupeol, a triterpene isolated from various herbal plants, possesses an anti-inflammatory function and has been proposed as a candidate for anticancer agents. The purpose of this research was to investigate the effect of lupeol on the viability, apoptosis, cell-cycle distribution, and migration of colorectal cancer cell lines and its molecular mechanism.

Methods

Lupeol was assessed for its anticancer effect using two human colorectal cancer cell lines: SW480 and HCT116. These cells were treated with lupeol, and their viability, apoptosis, migration, and cycle distribution were detected by CCK8, flow cytometry, and the transwell method. Quantitative PCR, Western blot, and immunofluorescence were applied to detect the expressions of CTNNB1, TCF4, cMYC, CCND1, CLDN1, and CCNA2.

Results

Lupeol suppressed cell viability and migration and induced cellular apoptosis of both cell lines, with increased p53 and decreased Bcl2 protein levels (P<0.05). Cell cycles of both lupeol-treated cell lines were arrested in the S phase (P<0.05). Quantitative PCR and Western blot analyses showed significantly reduced expressions of CTNNB1, TCF4, and downstream genes of the Wnt–β-catenin pathway, including the cell-cycle-regulated genes of cMYC and CCND1 of both cell lines upon lupeol treatment (P<0.05). mRNA and protein levels of CLDN1 decreased in HCT116 cells, plus the expression of CCNA2 mRNA and protein decreased in SW480 cells (P<0.05). Immunofluorescence analysis confirmed decreased expression of Wnt–β-catenin signaling.

Conclusion

Our findings indicate that lupeol effectively inhibits proliferation and migration and induces apoptosis and cell-cycle arrest of two colorectal cell lines by inactivation of the Wnt–β-catenin signaling pathway and downregulation of cMYC, CCND1, CCNA2, and CLDN1, thereby making it a promising anticancer candidate.

PMA treated THP-1-derived-IL-6 promotes EMT of SW48 through STAT3/ERK-dependent activation of Wnt/β-catenin signaling pathway

Colon cancer is one of the most common digestive malignant tumors that leads to high mortality worldwide, and metastasis is the primary cause of cancer-related death. It is well accepted that the epithelial-mesenchymal transition (EMT) plays a key role in the process of metastasis. As a cytokine that macrophage secretes, IL-6 is involved in the progression of tumors, including the invasion and metastasis via kinds of signaling pathways. However, the mechanism of interactions between IL-6, macrophage, EMT and colon cancer is not fully understood. Increased CD68⁺ macrophages and IL-6 level were found in colon tumor as compared to normal colon tissue. Metastatic lymph node showed even more CD68⁺ macrophages and higher IL-6 level than the primary tumor. These results suggested that macrophages and IL-6 play an important role in EMT of colon cancer. In order to investigate the effect of macrophage and IL-6 on EMT of colon cancer, we cultured human colon carcinoma cell line SW48 with conditioned medium (CM) from PMA-stimulated monocyte THP-1 cells and tested for IL-6 dependent EMT pathways. Wound healing assay and Transwell assay were used to analyze cell migration and invasion. Results showed that CM-treated SW48 cells increased IL-6 production and displayed elevated capacity of migration and invasion compared to untreated cells. Increased expressions of EMT markers (N-cadherin, Vimentin and β-catenin) and decreased expression of EMT marker(E-cadherin) were found in CM-treated SW48 cells by Western Blot. The addition of an anti-IL-6 antibody significantly inhibited the increase of EMT markers (Vimentin and β-catenin) as well as cell migration and invasion, suggesting that IL-6 played a critical role in promoting EMT of CM-treated SW48 cells. In addition, we found that the levels of p-STAT3 and p-ERK increased in CM-treated SW48 compared to untreated cells, which can be reversed by AG490, an inhibitor of JAK. In the meantime, the suppression of JAK-associated signaling pathways caused a decrease of β-catenin. In summary, our study suggested that macrophage-induced IL-6 promotes migration and invasion of colon cancer cell via Wnt/β-catenin pathway in STAT3/ERK-dependent way.

G2Vec: Distributed gene representations for identification of cancer prognostic genes

Identification of cancer prognostic genes is important in that it can lead to accurate outcome prediction and better therapeutic trials for cancer patients. Many computational approaches have been proposed to achieve this goal; however, there is room for improvement. Recent developments in deep learning techniques can aid in the identification of better prognostic genes and more accurate outcome prediction, but one of the main problems in the adoption of deep learning for this purpose is that data from cancer patients have too many dimensions, while the number of samples is relatively small. In this study, we propose a novel network-based deep learning method to identify prognostic gene signatures via distributed gene representations generated by G2Vec, which is a modified Word2Vec model originally used for natural language processing. We applied the proposed method to five cancer types including liver cancer and showed that G2Vec outperformed extant feature selection methods, especially for small number of samples. Moreover, biomarkers identified by G2Vec was useful to find significant prognostic gene modules associated with hepatocellular carcinoma.

MASTL induces Colon Cancer progression and Chemoresistance by promoting Wnt/β-catenin signaling

BACKGROUND

Chemotherapeutic agents that modulate cell cycle checkpoints and/or tumor-specific pathways have shown immense promise in preclinical and clinical studies aimed at anti-cancer therapy. MASTL (Greatwall in Xenopus and Drosophila), a serine/threonine kinase controls the final G2/M checkpoint and prevents premature entry of cells into mitosis. Recent studies suggest that MASTL expression is highly upregulated in cancer and confers resistance against chemotherapy. However, the role and mechanism/s of MASTL mediated regulation of tumorigenesis remains poorly understood.

METHODS

We utilized a large patient cohort and mouse models of colon cancer as well as colon cancer cells to determine the role of Mastl and associated mechanism in colon cancer.

RESULTS

Here, we show that MASTL expression increases in colon cancer across all cancer stages compared with normal colon tissue (P < 0.001). Also, increased levels of MASTL associated with high-risk of the disease and poor prognosis. Further, the shRNA silencing of MASTL expression in colon cancer cells induced cell cycle arrest and apoptosis in vitro and inhibited xenograft-tumor growth in vivo. Mechanistic analysis revealed that MASTL expression facilitates colon cancer progression by promoting the β-catenin/Wnt signaling, the key signaling pathway implicated in colon carcinogenesis, and up-regulating anti-apoptotic proteins, Bcl-xL and Survivin. Further studies where colorectal cancer (CRC) cells were subjected to 5-fluorouracil (5FU) treatment revealed a sharp increase in MASTL expression upon chemotherapy, along with increases in Bcl-xL and Survivin expression. Most notably, inhibition of MASTL in these cells induced chemosensitivity to 5FU with downregulation of Survivin and Bcl-xL expression.

CONCLUSION

Overall, our data shed light on the heretofore-undescribed mechanistic role of MASTL in key oncogenic signaling pathway/s to regulate colon cancer progression and chemo-resistance that would tremendously help to overcome drug resistance in colon cancer treatment.

Histopathologic Features of Colorectal Adenoma and Adenocarcinoma Developing Within Inflammatory Polyps in Miniature Dachshunds

Biopsy samples of colorectal polyps were collected and examined from 67 Miniature Dachshund dogs (including 35 cases with an additional biopsy). Histopathologic diagnoses of the initial biopsy samples were "inflammatory polyp" in 52 cases (78%), "adenoma" in 10 cases (15%), and "adenocarcinoma" in 5 cases (8%). Eight of 10 cases (80%) diagnosed as adenoma also had inflammatory polyp lesions in the same specimen. A second biopsy was performed in 25 cases (48%) initially diagnosed with inflammatory polyp. Pathologic diagnoses for the second biopsy were inflammatory polyp in 11 cases (44%), adenoma in 9 cases (36%), and adenocarcinoma in 5 cases (20%). The number of beta-catenin-positive nuclei in epithelial cells was significantly higher in adenoma (46%) and adenocarcinoma (75%) as compared with inflammatory polyp (6%). Normal epithelial cells and hyperplastic goblet cells in inflammatory polyps showed homogeneous positive cytoplasmic immunoreactivity for adenomatous polyposis coli (APC) antigen. However, APC expression was decreased in areas of intense nuclear beta-catenin expression in adenoma and adenocarcinoma lesions. Foci of cytokeratin 5/6-positive squamous cell-like neoplastic cells showed intense beta-catenin nuclear expression that was similar to squamous morules described in human colorectal tumors. The results of the present study suggest that the inflammatory polyp in Miniature Dachshunds is a progressive disease that may develop into adenoma and/or adenocarcinoma. In addition, immunohistochemical findings suggest that aberrations of APC and beta-catenin expression may be involved in tumor development within the inflammatory polyp lesions.