beta-Catenin-mediated signaling: a novel molecular target for chemoprevention with anti-inflammatory substances

Chemotherapeutic potential of betanin/capecitabine combination targeting colon cancer: experimental and bioinformatic studies exploring NFκB and cyclin D1 interplay

Introduction: Betanin (C₂₄H₂₆N₂O₁₃) is safe to use as food additives approved by the FDA with anti-inflammatory and anticancer effects in many types of cancer cell lines. The current experiment was designed to test the chemotherapeutic effect of the combination of betanin with the standard chemotherapeutic agent, capecitabine, against chemically induced colon cancer in mice. Methods: Bioinformatic approach was designed to get information about the possible mechanisms through which the drugs may control cancer development. Five groups of mice were assigned as, (i) saline, (ii) colon cancer, (iii) betanin, (iv) capecitabine and (v) betanin/capecitabine. Drugs were given orally for a period of six weeks. Colon tissues were separated and used for biological assays and histopathology. Results: In addition, the mRNA expression of TNF-α (4.58-fold), NFκB (5.33-fold), IL-1β (4.99-fold), cyclin D1 (4.07-fold), and IL-6 (3.55-fold) and protein levels showed several folds increases versus the saline group. Tumor histopathology scores in the colon cancer group (including cryptic distortion and hyperplasia) and immunostaining for NFκB (2.94-fold) were high while periodic-acid Schiff staining demonstrated poor mucin content (33% of the saline group). These pathologic manifestations were reduced remarkably in betanin/capecitabine group. Conclusion: Collectively, our findings demonstrated the usefulness of betanin/capecitabine combination in targeting colon cancer and highlighted that betanin is a promising adjuvant therapy to capecitabine in treating colon cancer patients.

Molecular Pathogenesis of Sporadic Desmoid Tumours and Its Implications for Novel Therapies: A Systematised Narrative Review

Sporadic desmoid-type fibromatosis is a rare, fibroblastic soft-tissue neoplasm with local aggressiveness but no metastatic potential. Aberrant Wnt/β-catenin signalling has been extensively linked to desmoid pathogenesis, although little is known about other molecular drivers and no established treatment approach exists. We aimed to summarise the current literature regarding the molecular pathogenesis of sporadic desmoid-type fibromatosis and to discuss the effects of both current and emerging novel therapies targeting these mechanisms. A literature search was conducted of MEDLINE^® ALL and EMBASE databases for published studies (2000–August 2021) using keywords related to ‘fibromatosis aggressive’, ‘immunohistochemistry’, ‘polymerase chain reaction’ and ‘mutation’. Articles were included if they examined the role of proteins in sporadic or extra-abdominal human desmoid-type fibromatosis pathogenesis. Searching identified 1684 articles. Following duplicate removal and eligibility screening, 36 were identified. After a full-text screen, 22 were included in the final review. At least 47% of desmoid-type fibromatosis cases displayed aberrant β-catenin immunoreactivity amongst ten studies. Cyclin D1 overexpression occurred in at least 40% of cases across five studies. Six studies reported oestrogen receptor-β expression with a range of 7.4–90%. Three studies implicated matrix metalloproteinases, with one study demonstrating vascular endothelial growth factor overexpression. One study explored the positive relationship between cyclooxygenase-2 and platelet-derived growth factor receptor-β. Aberrant Wnt/β-catenin signalling is a well-established pathogenic driver that may be targeted via downstream modulation. Growth factor signalling is best appreciated through the clinical trial effects of multi-targeted tyrosine kinase inhibitors, whilst oestrogen receptor expression data may only offer a superficial insight into oestrogen signalling. Finally, the tumour microenvironment presents multiple potential novel therapeutic targets.

Sporadic desmoid tumours are rare soft-tissue neoplasms that arise from connective tissues in the chest wall, head, neck and limbs. Whilst lacking metastatic potential, uncertainty surrounding their locally aggressive growth and unpredictable recurrence complicates treatment approaches. At the molecular level, alterations in the Wnt/β-catenin signalling pathway, a fundamental coordinator of cell growth and development, have been strongly linked to desmoid tumour development. Beyond this, however, little is known about other molecular drivers. In the case of progressive or life-threatening disease, complex treatment decisions are made regarding the use of surgery, radiotherapy or systemic treatment modalities. Of the targeted systemic therapies, a lack of comparative clinical studies further complicates medical treatment decision making as no definitive treatment approach exists. Therefore, this review aimed to summarise the literature regarding the molecular drivers of desmoid tumour pathogenesis and to discuss the current and emerging novel therapies targeting such mechanisms. Utilising findings from human desmoid tissue samples, we present the rationale for targeting downstream mediators of the central Wnt/β-catenin pathway and outline potential treatment targets in the tumour microenvironment. We also highlight the knowledge gained from clinical drug trials targeting desmoid growth factor signalling and present the potentially superficial insight provided by oestrogen receptor expression profiles on the role of oestrogen signalling in desmoid pathogenesis. In doing so, this work may assist in the eventual development of an evidence-based treatment approach for sporadic desmoid tumours.

Molecular docking analysis of aspirin analogues with β-catenin

Canonical Wnt signaling pathway plays a crucial role in cancer cell proliferation, which links by the growth of β-catenin in cell due to inactivation of glycogen synthetase kinase-3. Therefore, it is of interest to design novel candidates to bind with β-catenin. Hence, we document the molecular docking analysis data of aspirin analogues with β-catenin for further consideration.

β-Catenin in desmoid-type fibromatosis: deep insights into the role of T41A and S45F mutations on protein structure and gene expression

Desmoid‐type fibromatosis (DF) is a rare mesenchymal lesion with high risk of local recurrence. Specific β‐catenin mutations (S45F) appeared to be related to this higher risk compared to T41A‐mutated or wild‐type (WT). We explored the influence of both mutations and WT on structure stability and affinity of β‐catenin for α‐catenin and the pattern of gene expression that may influence DF behavior. Using 33 surgically resected primary DFs harboring T41A (n = 14), S45F (n = 10), or WT (n = 9), we performed a comparative molecular analysis by protein/protein interaction modeling, gene expression by DASL microarrays, human inflammation gene panel, and assessment of immune system‐based biomarkers by immunohistochemistry. Mutated proteins were more stable than WT and formed a weaker complex with α‐catenin. Consensus unsupervised gene clustering revealed the presence of two DF group‐mutated (T41A + S45F) and WT (P = 0.0047). The gene sets ‘Inflammatory‐Defense‐Humoral Immune Response’ and ‘Antigen Binding’ were significantly enriched in T41A. The deregulation of 16 inflammation‐related genes was confirmed. Low numbers of T cells and tumor‐associated macrophages (TAM) infiltrating the tumors and low/absent PD‐1/PD‐L1 expression were also identified. We demonstrated that mutated DFs (T41A or S45F) and WT are two distinct molecular subgroups with regard to β‐catenin stability, α‐catenin affinity, and gene expression profiling. A different inflammation signature characterized the two mutated groups, suggesting mediation either by T41A or by S45F. Finally, all mutated cases showed a low number of TIL and TAM cells and a low or absent expression of PD‐1 and PD‐L1 consistent with β‐catenin activation insensitive to checkpoint blockade.

The Role of Phytochemicals in the Inflammatory Phase of Wound Healing

Historically, plant-based products have been the basis of medicine since before the advent of modern Western medicine. Wound dressings made of honey, curcumin and other phytochemical-rich compounds have been traditionally used. Recently, the mechanisms behind many of these traditional therapies have come to light. In this review, we show that in the context of wound healing, there is a global theme of anti-inflammatory and antioxidant phytochemicals in traditional medicine. Although promising, we discuss the limitations of using some of these phytochemicals in order to warrant more research, ideally in randomized clinical trial settings.

Sulforaphane improves the bronchoprotective response in asthmatics through Nrf2-mediated gene pathways

Background

It is widely recognized that deep inspiration (DI), either before methacholine (MCh) challenge (Bronchoprotection, BP) or after MCh challenge (Bronchodilation, BD) protects against this challenge in healthy individuals, but not in asthmatics. Sulforaphane, a dietary antioxidant and antiinflammatory phytochemical derived from broccoli, may affect the pulmonary bronchoconstrictor responses to MCh and the responses to DI in asthmatic patients.

Methods

Forty-five moderate asthmatics were administered sulforaphane (100 μmol daily for 14 days), BP, BD, lung volumes by body-plethsmography, and airway morphology by computed tomography (CT) were measured pre- and post sulforaphane consumption.

Results

Sulforaphane ameliorated the bronchoconstrictor effects of MCh on FEV₁ significantly (on average by 21 %; p = 0.01) in 60 % of these asthmatics. Interestingly, in 20 % of the asthmatics, sulforaphane aggravated the bronchoconstrictor effects of MCh and in a similar number was without effect, documenting the great heterogeneity of the responsiveness of these individuals to sulforaphane. Moreover, in individuals in whom the FEV₁ response to MCh challenge decreased after sulforaphane administration, i.e., sulforaphane was protective, the activities of Nrf2-regulated antioxidant and anti-inflammatory genes decreased. In contrast, individuals in whom sulforaphane treatment enhanced the FEV₁ response to MCh, had increased expression of the activities of these genes. High resolution CT scans disclosed that in asthmatics sulforaphane treatment resulted in a significant reduction in specific airway resistance and also increased small airway luminal area and airway trapping modestly but significantly.

Conclusion

These findings suggest the potential value of blocking the bronchoconstrictor hyperresponsiveness in some types of asthmatics by phytochemicals such as sulforaphane.

TCF4 Is a Molecular Target of Resveratrol in the Prevention of Colorectal Cancer

The Wnt/β-catenin pathway plays an essential role in the tumorigenesis of colorectal cancer. T-cell factor-4 (TCF4) is a member of the TCF/LEF (lymphoid enhancer factor) family of transcription factors, and dysregulation of β-catenin is decisive for the initiation and progression of colorectal cancer. However, the role of TCF4 in the transcriptional regulation of its target gene remained poorly understood. Resveratrol is a dietary phytoalexin and present in many plants, including grape skin, nuts and fruits. Although resveratrol has been widely implicated in anti-tumorigenic and pro-apoptotic properties in several cancer models, the underlying cellular mechanisms are only partially understood. The current study was performed to elucidate the molecular mechanism of the anti-cancer activity of resveratrol in human colorectal cancer cells. The treatment of resveratrol and other phytochemicals decreased the expression of TCF4. Resveratrol decreases cellular accumulation of exogenously-introduced TCF4 protein, but did not change the TCF4 transcription. The inhibition of proteasomal degradation using MG132 (carbobenzoxy-Leu-Leu-leucinal) and lactacystin ameliorates resveratrol-stimulated down-regulation of TCF4. The half-life of TCF4 was decreased in the cells exposed to resveratrol. Resveratrol increased phosphorylation of TCF4 at serine/threonine residues through ERK (extracellular signal-regulated kinases) and p38-dependent pathways. The TCF4 knockdown decreased TCF/β-catenin-mediated transcriptional activity and sensitized resveratrol-induced apoptosis. The current study provides a new mechanistic link between resveratrol and TCF4 down-regulation and significant benefits for further preclinical and clinical practice.

Family-wide investigation of PDZ domain-mediated protein-protein interactions implicates β-catenin in maintaining the integrity of tight junctions

β-catenin is a multifunctional protein that plays a critical role in cell-cell contacts and signal transduction. β-catenin has previously been shown to interact with PDZ-domain-containing proteins through its C terminus. Using protein microarrays comprising 206 mouse PDZ domains, we identified 26 PDZ-domain-mediated interactions with β-catenin and confirmed them biochemically and in cellular lysates. Many of the previously unreported interactions involved proteins with annotated roles in tight junctions. We found that four tight-junction-associated PDZ proteins-Scrib, Magi-1, Pard3, and ZO-3-colocalize with β-catenin at the plasma membrane. Disrupting these interactions by RNA interference, overexpression of PDZ domains, or overexpression of the β-catenin C terminus altered localization of the full-length proteins, weakened tight junctions, and decreased cellular adhesion. These results suggest that β-catenin serves as a scaffold to establish the location and function of tight-junction-associated proteins.

Inhibitory effects of eupatilin on tumor invasion of human gastric cancer MKN-1 cells

Extracts of the whole herb of Artemisia asiatica Nakai (Asteraceae) are used in traditional oriental medicine to treat inflammation. Eupatilin (5,7-dihydroxy-3',4',6-trimethoxyflavone) is one of the pharmacologically active components found in A. asiatica, and has been shown to possess anti-tumoral effects in some malignancies, including gastric cancer. However, its anti-metastatic effect in gastric cancer is hardly known. In this study, anti-metastatic effect of eupatilin was investigated in the human gastric cancer cell line, MKN-1. Eupatilin inhibited MKN-1 growth in a dose- and a time-dependent manner, and induced apoptosis with a concomitant increase of caspase-3 activity. ELISA demonstrated that release of pro-inflammatory cytokines (IL-1β, TNF-α, IL-6, and IL-8) was significantly reduced by eupatilin. And p-AKT and p-ERK (p44/42) was reduced. Expression level of β-catenin and integrin was reduced and p-GSKβ was increased. In transcription reporter system, the activity of the transcriptional factor, NF-κB, was reduced by eupatilin and the expression of p65 was down-regulated when MKN-1 cells were treated with eupatilin. Moreover, a zymography study revealed that this reduction in invasive potential resulted from a reduction in type IV collagenolytic (gelatinolytic) activity. The expressions of metalloproteinases (MMP-2 and MMP-9) were also reduced in MKN-1 cells treated with eupatilin. In vitro invasion assay, eupatilin inhibited MKN-1 penetrating reconstituted basement membrane barriers. These results suggest that eupatilin inhibits the MKN-1 gastric cancer cell proliferation via activation of caspase-3 and the metastatic potential of gastric cancer cells via down-regulation of NF-κB activity followed by reduction of pro-inflammatory cytokine-mediated MMPs expressions.

Intervening in β-catenin signaling by sulindac inhibits S100A4-dependent colon cancer metastasis

Colon cancer metastasis is often associated with activation of the Wnt/β-catenin signaling pathway and high expression of the metastasis mediator S100A4. We previously demonstrated the transcriptional regulation of S100A4 by β-catenin and the importance of the interconnection of these cellular programs for metastasis. Here we probe the hypothesis that the nonsteroidal anti-inflammatory drug sulindac sulfide can inhibit colon cancer metastasis by intervening in β-catenin signaling and thereby interdicting S100A4. We treated colon cancer cell lines heterozygous for gain-of-function and wild-type β-catenin with sulindac. We analyzed sulindac's effects on β-catenin expression and subcellular localization, β-catenin binding to the T-cell factor (TCF)/S100A4 promoter complex, S100A4 promoter activity, S100A4 expression, cell motility, and proliferation. Mice intrasplenically transplanted with S100A4-overexpressing colon cancer cells were treated with sulindac. Tumor growth and metastasis, and their β-catenin and S100A4 expressions, were determined. We report the expression knockdown of β-catenin by sulindac, leading to its reduced nuclear accumulation. The binding of β-catenin to TCF was clearly lowered, resulting in reduced S100A4 promoter activity and expression. This correlated well with the inhibition of cell migration and invasion, which could be rescued by ectopic S100A4 expression. In mice, sulindac treatment resulted in reduced tumor growth in the spleen (P = .014) and decreased liver metastasis in a human colon cancer xenograft model (P = .025). Splenic tumors and liver metastases of sulindac-treated mice showed lowered β-catenin and S100A4 levels. These results suggest that modulators of β-catenin signaling such as sulindac offer potential as antimetastatic agents by interdicting S100A4 expression.

RET/PTC1-driven neoplastic transformation and proinvasive phenotype of human thyrocytes involve Met induction and beta-catenin nuclear translocation

Activation of the RET gene by chromosomal rearrangements generating RET/PTC oncogenes is a frequent, early, and causative event in papillary thyroid carcinoma (PTC). We have previously shown that, in human primary thyrocytes, RET/PTC1 induces a transcriptional program including the MET proto-oncogene. In PTCs, beta-catenin is frequently mislocated to the cytoplasm nucleus. We investigated the interplay between Ret/ptc1 signaling and Met in regulating the proinvasive phenotype and beta-catenin localization in cellular models of human PTC. Here, we show that Met protein is expressed and is constitutively active in human thyrocytes exogenously expressing RET/PTC1 as well as a mutant (Y451F) devoid of the main Ret/ptc1 multidocking site. Both in transformed thyrocytes and in the human PTC cell line TPC-1, Ret/ptc1-Y451-dependent signaling and Met cooperated to promote a proinvasive phenotype. Accordingly, gene/functional silencing of either RET/PTC1 or MET abrogated early branching morphogenesis in TPC-1 cells. The same effect was obtained by blocking the common downstream effector Akt. Y451 of Ret/ptc1 was required to promote proliferation and nuclear translocation of beta-catenin, suggesting that these oncogene-driven effects are Met-independent. Pharmacologic inhibition of Ret/ptc1 and Met tyrosine kinases by the multitarget small molecule RPI-1 blocked cell proliferation and invasive ability and dislocated beta-catenin from the nucleus. Altogether, these results support that Ret/ptc1 cross talks with Met at transcriptional and signaling levels and promotes beta-catenin transcriptional activity to drive thyrocyte neoplastic transformation. Such molecular network, promoting disease initiation and acquisition of a proinvasive phenotype, highlights new options to design multitarget therapeutic strategies for PTCs.

Molecular analysis of the effects of Piroxicam and Cisplatin on mesothelioma cells growth and viability

Nonsteroidal anti-inflammatory drugs (NSAIDs) have been proposed for prevention and treatment of a variety of human cancers. Piroxicam, in particular, has been recently shown to exert significant anti-tumoral activity in combination with cisplatin (CDDP) on mesothelioma cells. However, the mechanisms through which NSAIDs regulate the cell cycle as well as the signal pathways involved in the growth inhibition, remain unclear. In the present study, using two mesothelioma cell lines, MSTO-211H and NCI-H2452, we have investigated the influence of piroxicam alone and in association with CDDP on proliferation, cell cycle regulation and apoptosis. In both cell lines a significant effect on cell growth inhibition, respect to the control, was observed with all the drugs tested. Moreover, treatment with piroxicam or CDDP alone altered the cell cycle phase distribution as well as the expression of some cell cycle regulatory proteins in both cell lines. These effects were increased, even if in a not completely overlapping manner, after treatment with the association of piroxicam and CDDP. In particular, the two drugs in NCI cell line had a synergistic effect on apoptosis, probably through activation of caspase 8 and caspase 9, while the most evident targets among the cell cycle regulators were cyclin D1 and p21waf1. These results suggest that the association of piroxicam and CDDP specifically triggers cell cycle regulation and apoptosis in different mesothelioma cell lines and may hold promise in the treatment of mesothelioma.

Chemoprevention by white currant is mediated by the reduction of nuclear beta-catenin and NF-kappaB levels in Min mice adenomas

BACKGROUND

Berries are a good natural source of phenolic compounds and many berries or their compounds have been shown to be chemopreventive. White currant is an interesting berry, as it contains low levels of dominant berry phenolics such as ellagic acid, anthocyanins and other flavonoids.

AIMS OF THE STUDY

To study if white currant is chemopreventive in an experimental model for intestinal tumorigenesis and further study the effects on beta-catenin and NF-kappaB signaling pathways.

METHODS

Multiple intestinal neoplasia (Min) mice were fed an AIN-93G based control diet or a diet containing 10% freeze dried white currant (Ribes x pallidum) for 10 weeks. Cell signaling parameters were analysed from intestinal adenomas and surrounding mucosa by Western blotting and immunohistochemistry.

RESULTS

The white currant diet reduced the number of adenomas from 81 (min-max 47-114) to 51 (36-84) in the total small intestine of Min mice (P<0.02). Most of the adenomas develop in the distal part of the small intestine, and in this area white currant reduced the number from 49 to 29.5 (P<0.01) and also the size of the adenomas from 0.88 mm to 0.70 mm (P<0.02). In the colon white currant increased the number of adenomas (0.3+/-0.6 vs. 0.8+/-0.6, mean +/- SD, P<0.05), but did not affect the size. White currant reduced nuclear beta-catenin and NF-kappaB protein levels in the adenomas (P<0.05 and P<0.02, respectively). They were correlated with the size of adenomas (P<0.01).

CONCLUSIONS

This study shows that white currant is effective in preventing cancer initiation and progression in the Min mouse. Whether the positive effects are due to its special phenolic composition needs to be studied in more detail.

Cyclooxygenase-2 and platelet-derived growth factor receptors as potential targets in treating aggressive fibromatosis

PURPOSE

To explore the molecular bases of potential new pharmacologic targets in aggressive fibromatosis (desmoid tumor).

EXPERIMENTAL DESIGN

Tumor specimens from 14 patients surgically treated for aggressive fibromatosis (6 familial adenomatous polyposis and 8 sporadic cases), analyzed for adenomatous polyposis coli (APC) and CTNNB1 (beta-catenin) mutations, were further investigated for beta-catenin, cyclooxygenase-2 (COX-2), platelet-derived growth factor (PDGF) receptor alpha (PDGFRA)/PDGF receptor beta (PDGFRB), their cognate ligands (PDGFA and PDGFB), and KIT using a comprehensive immunohistochemical, biochemical, molecular, and cytogenetic approach.

RESULTS

No CTNNB1 (beta-catenin) mutations were found in the familial adenomatous polyposis patients, but previously reported activating mutations were found in six of the eight sporadic patients. All of the cases carrying an altered WNT pathway showed nuclear and cytoplasmic immunoreactivity for beta-catenin, whereas beta-catenin expression was restricted to the cytoplasm in the sporadic patients lacking CTNNB1 mutations. COX-2 protein and mRNA overexpression was detected in all 14 cases, together with the expression and phosphorylation of PDGFRA and PDGFRB, which in turn paralleled the presence of their cognate ligands. No PDGFRB mutations were found. The results are consistent with PDGFRA and PDGFRB activation sustained by an autocrine/paracrine loop.

CONCLUSIONS

Aggressive fibromatosis is characterized by WNT/oncogene pathway alterations triggering COX-2-mediated constitutive coactivation of PDGFRA and PDGFRB, and may therefore benefit from combined nonsteroidal anti-inflammatory drug + tyrosine kinase inhibitor treatment.