β-catenin in oral cancer: an update on current knowledge

Mapping the intricacies of GLI1 in hedgehog signaling: A combined bioinformatics and clinical analysis in Head & Neck cancer in Western India

BACKGROUND

Activation of various cancer stem cell pathways are thought to be responsible for treatment failure and loco-regional recurrence in Head and Neck cancer. Hedgehog signaling, a major cancer stem signaling pathway plays a major role in relapse of disease. GLI1, a transcription activator, plays an important role in canonical/non-canonical activation of Hedgehog signaling.

METHODS

Data for H&N cancer patients were collected from The Cancer Genome Atlas- H&N Cancer (TCGA-HNSC). GLI1 co-expressed genes in TCGA-HNSC were then identified using cBioPortal and subjected to KEGG pathway analysis by DAVID tool. Network Analyzer and GeneMania plugins from CytoScape were used to identify hub genes and predict a probable pathway from the identified hub genes respectively. To confirm the hypothesis, real-time gene expression was carried out in 75 patients of head and neck cancer.

RESULTS

Significantly higher GLI1 expression was observed in tumor tissues of H&N cancer and it also showed worst overall survival. Using cBioPortal tool, 2345 genes were identified that were significantly co-expressed with GLI1. From which, 15 hub genes were identified through the Network Analyzer plugin in CytoScape. A probable pathway prediction based on hub genes showed the interconnected molecular mechanism and its role in non-canonical activation of Hedgehog pathway by altering the GLI1 activity. The expressions of SHH, GLI1 and AKT1 were significant with each other and were found to be significantly associated with Age, Lymph-Node status and Keratin.

CONCLUSION

The study emphasizes the critical role of the Hh pathway's activation modes in H&N cancer, particularly highlighting the non-canonical activation through GLI1 and AKT1. The identification of SHH, GLI1 and AKT1 as potential diagnostic biomarkers and their association with clinic-pathological parameters underscores their relevance in prognostication and treatment planning. Hh pathway activation through GLI1 and its cross-talk with various pathways opens up the possibility of newer treatment strategies and developing a panel of therapeutic targets in H&N cancer patients.

Expression Profile of Circulating Exosomal microRNAs in Leukoplakia, Oral Submucous Fibrosis, and Combined Lesions of Leukoplakia and Oral Submucous Fibrosis

OBJECTIVES

This study aims to elucidate the expression of circulating exosomal miRNAs miRNA 21, miRNA 184, and miRNA 145 in the studied groups, including patients with (i) leukoplakia; (ii) oral submucous fibrosis; (iii) oral submucous fibrosis with leukoplakia; (iv) oral squamous cell carcinoma; and (v) healthy individuals.

STUDY DESIGN

An observational study was conducted among 54 patients who reported to the outpatient department of Saveetha Dental College and Hospitals. The patients were divided into three groups: Group I healthy individuals (n = 18), Group II: case group (leukoplakia, OSMF, and leukoplakia and OSMF) (n = 18), and Group III: OSCC (n = 18). Real-time polymerase chain reaction analysis was carried out to assess the expression profiles of miRNA 21, miRNA 184, and miRNA 145. The statistical analysis was calculated using SPSS software version 23.

RESULTS

All three miRNAs showed a statistically significant difference in the one-way ANOVA test between the case group (leukoplakia, OSMF, and leukoplakia and OSMF), healthy group, and OSCC group (p < 0.005). The case group (leukoplakia, OSMF, leukoplakia and OSMF) showed upregulated expression of miRNA 21 and miRNA 184 with threefold change and fourfold change and downregulated expression of miRNA 145 with 1.5-fold change when compared to apparently healthy individuals.

CONCLUSION

Plasma circulating exosomal miRNAs miRNA 21, miRNA 145, and miRNA 184 expression could be a novel panel of plasma biomarkers to categorise case group (leukoplakia, OSMF, leukoplakia and OSMF) patients with a high risk of malignant transformation.

Cadherin switching in oral squamous cell carcinoma: A clinicopathological study

Background and aim

Oral squamous cell carcinoma (OSCC) is one of the most common malignancies worldwide as it represents the sixth most common cancer. Numerous molecular mechanisms have been explained to regulate OSCC progression, including epithelial-mesenchymal transition (EMT). Cadherin switching is the pivotal process that controls EMT in which E-cadherin reduces while N-cadherin elevates. This work aimed to clarify the role of cadherin switching in OSCC.

Material and methods

Thirty paraffin-embedded tissue blocks of OSCC including six cases with lymph node metastasis were subjected to immunohistochemical staining using antibodies against E&N-cadherins. Cell cultures were performed using OSCC cell lines (SCC-15/SCC-25) from the human tongue. F-12K medium (Kaighn's Modification of Ham's F12 Medium) was added as EMT inducing media. E&N-cadherin mRNA gene expression levels were detected by real time-polymerase chain reaction (RT-PCR).

Results

Cadherin switching through N-cadherin elevation and E-cadherin reduction was evaluated at the histopathologic level in primary and metastatic OSCC as well as at the genetic level within OSCC cell culture. Cadherin switching showed a significant correlation between E&N-cadherins at different histopathological grades of OSCC and in metastatic OSCC. Moreover, the level of mRNA gene expression of E&N-cadherins in human 15 SCC and 25 SCC cell lines with EMT-inducing media exhibited a significant correlation.

Conclusions

Cadherin switching is a crucial event in the EMT process. It may be used as a significant tool in the study of OSCC progression. Cadherin switching plays a significant role in the invasion and metastasis of OSCC.

In vitro and in vivo anti-tumor activity of Coenzyme Q0 against TWIST1-overexpressing HNSCC cells: ROS-mediated inhibition of EMT/metastasis and autophagy/apoptosis induction

HNSCC (Head and Heck Squamous Cell Carcinoma) is a reasonably prevalent cancer with a high mortality rate. In this study, we tried to examine the anti-metastasis and apoptosis/autophagy actions of Coenzyme Q₀ (CoQ₀, 2,3-dimethoxy-5-methyl-1,4-benzoquinone), a derivative of Antrodia camphorata in HNCC TWIST1 overexpressing (FaDu-TWIST1) cells as well as in vivo tumor xenograft mice model. Using fluorescence based cellular assays, western blot and nude mice tumor xenografts, we determined that CoQ₀ effectively reduced cell viability and displayed rapid morphological changes in FaDu-TWIST1 cells compared to FaDu cells. Non/sub-cytotoxic concentrations of CoQ₀ treatment reduces the cell migration by downregulating TWIST1 and upregulating E-cadherin. Apoptosis produced by CoQ₀ was mostly related with caspase-3 activation, PARP cleavage, and VDAC-1 expression. The FaDu-TWIST1 cells treated with CoQ₀ exhibits autophagy-mediated LC3-II accumulation and acidic vesicular organelles (AVOs) formation. Pre-treatment with 3-MA and CoQ effectively prevented CoQ₀-induced cell death and CoQ₀-triggered autophagy in FaDu-TWIST cells as a death mechanism. CoQ₀ induces ROS production in FaDu-TWIST1 cells and NAC pre-treatment significantly reduces anti-metastasis, apoptosis, and autophagy. Likewise, ROS-mediated AKT inhibition regulates CoQ₀-induced apoptosis/autophagy in FaDu-TWIST1 cells. In vivo studies exhibit, CoQ₀ effectively delays and reduces the tumor incidence and burden in FaDu-TWIST1-xenografted nude mice. Current findings display, CoQ₀ exhibits a novel anti-cancer mechanism hence, it might be appropriate for anticancer therapy, and a new potent drug for HNSCC.

miRNAs as potential game-changers in head and neck cancer: Future clinical and medicinal uses

Head and neck cancers (HNCs) are a group of heterogeneous tumors formed most frequently from epithelial cells of the larynx, lips, oropharynx, nasopharynx, and mouth. Numerous epigenetic components, including miRNAs, have been demonstrated to have an impact on HNCs characteristics like progression, angiogenesis, initiation, and resistance to therapeutic interventions. The miRNAs may control the production of numerous genes linked to HNCs pathogenesis. The roles that miRNAs play in angiogenesis, invasion, metastasis, cell cycle, proliferation, and apoptosis are responsible for this impact. The miRNAs also have an impact on crucial HNCs-related mechanistic networks like the WNT/β-catenin signaling, PTEN/Akt/mTOR pathway, TGFβ, and KRAS mutations. miRNAs may affect how the HNCs respond to treatments like radiation and chemotherapy in addition to pathophysiology. This review aims to demonstrate the relationship between miRNAs and HNCs with a particular emphasis on how miRNAs impact HNCs signaling networks.

Prognostic and Clinicopathological Significance of Telomerase Reverse Transcriptase Upregulation in Oral Cancer: A Systematic Review and Meta-Analysis

The aim of this systematic review and meta-analysis was to evaluate the current evidence on the prognostic and clinicopathological significance value of telomerase reverse transcriptase (TERT) upregulation in patients with oral squamous cell carcinoma (OSCC). PubMed, Embase, Web of Science, and Scopus were searched for studies published before April 2022, not restricted by date or publication language. The methodological quality of primary-level studies was critically assessed using the Quality in Prognosis Studies (QUIPS) tool. We carried out meta-analyses, explored heterogeneity and its sources, and performed subgroup, meta-regression, sensitivity, and small-study effects analyses. Twenty-one studies (1698 patients) met inclusion criteria. TERT protein overexpression was significantly associated with worse overall survival (hazard ratio [HR] = 3.01, 95% CI = 1.70−5.35, p < 0.001), disease-free survival (HR = 4.03, 95% CI = 1.80−9.05, p = 0.001), and higher histological grade OSCC (odds ratio [OR] = 3.20, 95% CI = 1.83−5.62, p < 0.001). These large effect sizes were consistently obtained by homogeneous subgroups (p > 0.10, I2 = 0.0, respectively), which reflects a high quality of evidence. On the other hand, TERT gene mutations obtained constantly nonsignificant null effect sizes for all outcomes investigated, evidencing no prognostic or clinicopathological value. In conclusion, our findings indicate that TERT upregulation is a prognostic indicator of poor survival in oral cancer. Our findings support the immunohistochemical assessment of TERT overexpression, which could probably be incorporated into the prognostic evaluation of OSCC.

Knockdown of nuclear receptor binding SET domain-containing protein 1 (NSD1) inhibits proliferation and facilitates apoptosis in paclitaxel-resistant breast cancer cells via inactivating the Wnt/β-catenin signaling pathway

The burden of breast cancer (BC) has exacerbated over decades. Paclitaxel resistance is responsible for increasing BC treatment burden. Nuclear receptor binding SET domain-containing protein 1 (NSD1) is positively correlated with a poor prognosis in patients with BC. This study investigates the function of NSD1 in paclitaxel-resistant (PR) BC cells. The high levels of NSD1 and Wnt10b in PR BC cell lines (MCF-7/PR) or MCF-7 parental cells were determined by RT-qPCR. Western blotting was conducted to measure the levels of NSD1 protein, apoptosis-associated proteins, Wnt10b protein, H3K36me2 protein, H3K27me3 protein, and signal pathway-associated proteins in MCF-7/PR cells or MCF-7 cells or in vivo subcutaneous xenografted tumor model, and the results demonstrated that NSD1 inhibited cell apoptosis and promoted cell proliferation and tumor growth via activating Wnt/β-catenin pathway. Cell apoptosis and viability were estimated using cell counting kit-8 assays and flow cytometry. Positive correlation between NSD1 and Wnt10b was identified by chromatin immunoprecipitation assay. The distribution of β-catenin was determined by immunofluorescence assays. We conclude that NSD1 knockdown inhibits the viability and promotes the apoptosis of paclitaxel-resistant BC cells by inactivating the NSD1/H3K27me3/Wnt10b/β-catenin signaling pathway.

Prognostic and Clinicopathological Significance of the Aberrant Expression of β-Catenin in Oral Squamous Cell Carcinoma: A Systematic Review and Meta-Analysis

Simple Summary

β-catenin is a multifunctional protein whose physiological functions are mainly related to the maintenance of cell-cell adhesion by forming complexes with the adhesion molecule E-cadherin, both responsible for the preservation of squamous epithelia homeostasis. The loss of β-catenin expression in the cell membrane, the failure of cytoplasmic degradation mechanisms—essentially related to the activation of Wnt canonical oncogenic pathway—and/or its translocation to the nucleus—developing actions as a transcription factor of oncogenes—are aberrant mechanisms with oncogenic implications in oral carcinogenesis. In this systematic review and meta-analysis on 41 studies and 2746 oral squamous cell carcinoma (OSCC) patients we demonstrate that the aberrant expression of β-catenin—mainly the immunohistochemical analysis of its loss in the cell membrane—behaves as a prognostic biomarker, significantly associated with poor survival, essentially linked to the increased risk for the development of lymph node metastases, higher tumour size and clinical stage in these patients.

Abstract

This systematic review and meta-analysis aims to evaluate the prognostic and clinicopathological significance of the aberrant expression of β-catenin (assessed through the immunohistochemical loss of membrane expression, cytoplasmic and nuclear expression) in oral squamous cell carcinoma (OSCC). We searched for primary-level studies published before October-2021 through PubMed, Embase, Web of Science, Scopus, and Google Scholar, with no limitation in regard to their publication date or language. We evaluated the methodological quality and risk of bias of the studies included using the QUIPS tool, carried out meta-analyses, explored heterogeneity and their sources across subgroups and meta-regression, and conducted sensitivity and small-study effects analyses. Forty-one studies (2746 patients) met inclusion criteria. The aberrant immunohistochemical expression of β-catenin was statistically associated with poor overall survival (HR = 1.77, 95% CI = 1.20–2.60, p = 0.004), disease-free survival (HR = 2.44, 95% CI = 1.10–5.50, p = 0.03), N+ status (OR = 2.39, 95% CI = 1.68–3.40, p < 0.001), higher clinical stage (OR = 2.40, 95% CI = 1.58–3.63, p < 0.001), higher tumour size (OR = 1.76, 95% CI = 1.23–2.53, p = 0.004), and moderately-poorly differentiated OSCC (OR = 1.57, 95% CI = 1.09–2.25, p = 0.02). The loss of β-catenin in the cell membrane showed the largest effect size in most of meta-analyses (singularly for poor overall survival [HR = 2.37, 95% CI = 1.55–3.62, p < 0.001], N+ status [OR = 3.44, 95% CI = 2.40–4.93, p < 0.001] and higher clinical stage [OR = 2.51, 95% CI = 1.17–5.35, p = 0.02]). In conclusion, our findings indicate that immunohistochemical assessment of the aberrant expression of β-catenin could be incorporated as an additional and complementary routine prognostic biomarker for the assessment of patients with OSCC.

Isoorientin inhibits epithelial-to-mesenchymal properties and cancer stem-cell-like features in oral squamous cell carcinoma by blocking Wnt/β-catenin/STAT3 axis

Oral squamous cell carcinoma (OSCC) is among the most prevalent cancers of the head and neck. This study revealed that isoorientin attenuates OSCC cell stemness and epithelial-mesenchymal transition potential through the inhibition of JAK/signal transducer and activator of transcription 3 (STAT3) and Wnt/β-catenin signaling in cell lines. Our findings indicated that isoorientin is a potential inhibitor of β-catenin/STAT3 in vitro and in vivo. We analyzed possible synergism between isoorientin and cisplatin in OSCC. A sulforhodamine B assay, colony formation assay, tumorsphere-formation assay, and Wnt reporter activity assay were used for determining cell invasion, cell migration, drug cytotoxicity, and cell viability with potential molecular mechanisms in vitro. Isoorientin reduced the expression of p-STAT3, β-catenin, and p-GSK3 as well as downstream effectors TCF1/TCF7 and LEF1 and significantly reduced β-catenin colocalization in the nucleus. Isoorientin markedly strengthened the cytotoxic effects of cisplatin against SAS and SCC-25. Therefore, combining isoorientin and cisplatin treatments can potentially improve the anticancer effect of cisplatin. Isoorientin inhibited the tumorigenicity and growth of OSCC through the abrogation of Wnt/β-catenin/STAT3 signaling in vivo. Thus, isoorientin disrupted the β-catenin signaling pathway through the inactivation of STAT3 signaling. In conclusion, targeting OSCC-SC-mediated stemness with isoorientin to eradicate OSCC-SCs may be an effective strategy for preventing relapse and metastasis of OSCC and providing long-term survival benefits.

Roles of the Wnt Signaling Pathway in Head and Neck Squamous Cell Carcinoma

Head and neck squamous cell carcinoma (HNSCC) is the most common type of head and neck tumor. It is a high incidence malignant tumor associated with a low survival rate and limited treatment options. Accumulating conclusions indicate that the Wnt signaling pathway plays a vital role in the pathobiological process of HNSCC. The canonical Wnt/β-catenin signaling pathway affects a variety of cellular progression, enabling tumor cells to maintain and further promote the immature stem-like phenotype, proliferate, prolong survival, and gain invasiveness. Genomic studies of head and neck tumors have shown that although β-catenin is not frequently mutated in HNSCC, its activity is not inhibited by mutations in upstream gene encoding β-catenin, NOTCH1, FAT1, and AJUBA. Genetic defects affect the components of the Wnt pathway in oral squamous cell carcinoma (OSCC) and the epigenetic mechanisms that regulate inhibitors of the Wnt pathway. This paper aims to summarize the groundbreaking discoveries and recent advances involving the Wnt signaling pathway and highlight the relevance of this pathway in head and neck squamous cell cancer, which will help provide new insights into improving the treatment of human HNSCC by interfering with the transcriptional signaling of Wnt.

Evidence for AJUBA-catenin-CDH4-linked differentiation resistance of mesenchymal stem cells implies tumorigenesis and progression of head and neck squamous cell carcinoma: a single-cell transcriptome approach

An increasing number of reports indicate that mesenchymal stem cells (MSCs) play an essential role in promoting tumorigenesis and progression of head and neck squamous cell carcinoma (HNSCC). However, the molecular mechanisms underlying this process remain unclear. Using the MSC model system, this study analyzes the molecular pathway by which differentiation resistant MSCs promote HNSCC. MSCs were cultured in osteogenic differentiation media and harvested on days 12 and 19. Cells were stained for cell differentiation analysis using Alizarin Red. The osteogenesis-resistant MSCs (OR-MSCs) and MSC-differentiation-derived osteoblasts (D-OSTBs) were identified and subjected to the single-cell transcriptome analysis. Gene-specific analyses of these two sub-populations were performed for the patterns of differential expression. A total of 1 780 differentially expressed genes were determined to distinguish OR-MSCs significantly from D-OSTB. Notably, AJUBA, β-catenin, and CDH4 expression levels were upregulated considerably within the OR-MSCs compared to D-OSTBs. To confirm their clinical relevance, a survey of a clinical cohort revealed a high correlation among the expression levels of AJUBA, β-catenin and CDH4. The results shed new light that OR-MSCs participate in the development of HNSCC via a pathway mediated by AJUBA, β-catenin, CDH4, and CTNNB1, thereby implying that MSC-based therapy is a promising therapeutic approach in the management of HNSCC.

Involvement of the ERK/HIF-1α/EMT Pathway in XCL1-Induced Migration of MDA-MB-231 and SK-BR-3 Breast Cancer Cells

Chemokine–receptor interactions play multiple roles in cancer progression. It was reported that the overexpression of X-C motif chemokine receptor 1 (XCR1), a specific receptor for chemokine X-C motif chemokine ligand 1 (XCL1), stimulates the migration of MDA-MB-231 triple-negative breast cancer cells. However, the exact mechanisms of this process remain to be elucidated. Our study found that XCL1 treatment markedly enhanced MDA-MB-231 cell migration. Additionally, XCL1 treatment enhanced epithelial–mesenchymal transition (EMT) of MDA-MB-231 cells via E-cadherin downregulation and upregulation of N-cadherin and vimentin as well as increases in β-catenin nucleus translocation. Furthermore, XCL1 enhanced the expression of hypoxia-inducible factor-1α (HIF-1α) and phosphorylation of extracellular signal-regulated kinase (ERK) 1/2. Notably, the effects of XCL1 on cell migration and intracellular signaling were negated by knockdown of XCR1 using siRNA, confirming XCR1-mediated actions. Treating MDA-MB-231 cells with U0126, a specific mitogen-activated protein kinase kinase (MEK) 1/2 inhibitor, blocked XCL1-induced HIF-1α accumulation and cell migration. The effect of XCL1 on cell migration was also evaluated in ER^-/HER2⁺ SK-BR-3 cells. XCL1 also promoted cell migration, EMT induction, HIF-1α accumulation, and ERK phosphorylation in SK-BR-3 cells. While XCL1 did not exhibit any significant impact on the matrix metalloproteinase (MMP)-2 and -9 expressions in MDA-MB-231 cells, it increased the expression of these enzymes in SK-BR-3 cells. Collectively, our results demonstrate that activation of the ERK/HIF-1α/EMT pathway is involved in the XCL1-induced migration of both MDA-MB-231 and SK-BR-3 breast cancer cells. Based on our findings, the XCL1–XCR1 interaction and its associated signaling molecules may serve as specific targets for the prevention of breast cancer cell migration and metastasis.

Curcumin Affects Gastric Cancer Cell Migration, Invasion and Cytoskeletal Remodeling Through Gli1-β-Catenin

Purpose

The function of curcumin on the gastric cancer cell line, SGC-7901 is unknown. The present study aimed to observe the effects of curcumin on gastric cancer cells through the Shh and Wnt signaling pathways.

Methods

SGC-7901 cells were transfected with si-Gli1 and si-β-catenin siRNA, then cells were stimulated with curcumin and its effects on cell migration, invasion, cytoskeleton remodeling, EMT, apoptosis and cell cycle were investigated by transwell assays, immunofluorescence and flow cytometry assays. The interaction between Gli1 and β-catenin was observed by co-immunoprecipitation.

Results

We show that curcumin suppressed the expression of Shh, Gli1 and Foxm1 in the Shh signaling pathway, and the expression of β-catenin in the Wnt signaling pathway in SGC-7901 cells, both in mRNA and protein. As a result, cellular migration, invasion and cytoskeletal remodeling ability decreased. Our results revealed that when stimulated with curcumin, cells showed decreased cellular migration and invasion, while enhanced apoptosis. In addition, curcumin induced cytoskeletal remodeling and S phase cell cycle arrest. The inhibition of Shh and Wnt signaling pathway and the addition of curcumin also inhibited the epithelial–mesenchymal transition process. Furthermore, a physical interaction was observed between Gli1 of the Shh signaling and β-catenin of the Wnt signaling in these cells, but curcumin inhibited the interaction of these two proteins.

Conclusion

The present study indicated that curcumin plays an anti-tumor role through Gli1-β-catenin pathway in gastric cancer SGC-7901 cells.

The Role of Carcinogenesis-Related Biomarkers in the Wnt Pathway and Their Effects on Epithelial-Mesenchymal Transition (EMT) in Oral Squamous Cell Carcinoma

As oral squamous cell carcinoma (OSCC) can develop from potentially malignant disorders (PMDs), it is critical to develop methods for early detection to improve the prognosis of patients. Epithelial-mesenchymal transition (EMT) plays an important role during tumor progression and metastasis. The Wnt signaling pathway is an intercellular pathway in animals that also plays a fundamental role in cell proliferation and regeneration, and in the function of many cell or tissue types. Specific components of master regulators such as epithelial cadherin (E-cadherin), Vimentin, adenomatous polyposis coli (APC), Snail, and neural cadherin (N-cadherin), which are known to control the EMT process, have also been implicated in the Wnt cascade. Here, we review recent findings on the Wnt signaling pathway and the expression mechanism. These regulators are known to play roles in EMT and tumor progression, especially in OSCC. Characterizing the mechanisms through which both EMT and the Wnt pathway play a role in these cellular pathways could increase our understanding of the tumor genesis process and may allow for the development of improved therapeutics for OSCC.

WNT7A Promotes EGF-Induced Migration of Oral Squamous Cell Carcinoma Cells by Activating β-Catenin/MMP9-Mediated Signaling

Aims and hypothesis

Epidermal growth factor (EGF) has been shown to induce the migration of various cancer cells. However, the underlying signaling mechanisms for EGF-induced migration of oral squamous cell carcinoma (OSCC) remain to be elucidated. WNT7A, a member of the family of 19 Wnt secreted glycoproteins, is commonly associated with tumor development. It is mostly unknown whether and, if so, how EGF modulates WNT7A in OSCC cells. The role of WNT7A in OSCC was thus investigated to explore the underlying signaling mechanisms for EGF-induced migration of OSCC.

Methods

Cell migration was measured by Wound healing assay and Transwell assay. Western blotting was carried out to detect the expression of WNT7A, MMP9, β-catenin, p-AKT, and p-ERK. The cells were transfected with plasmids or siRNA to upregulate or downregulate the expression of WNT7A. The location of β-catenin was displayed by immunofluorescence microscopy. Immunohistochemistry was carried out to confirm the relation between WNT7A expression and OSCC progression.

Results

The present study showed that the levels of WNT7A mRNA and protein were increased by EGF stimulation in OSCC cells. Besides, it was proved that p-AKT, but not p-ERK, mediated the expression of WNT7A protein induced by EGF. Furthermore, the inhibition of AKT activation prevented the EGF-induced increase of WNT7A and matrix metallopeptidase 9 (MMP9) expression and translocation of β-catenin from the cytoplasm to the nucleus. Moreover, histological analysis of OSCC specimens revealed an association between WNT7A expression and poor clinical prognosis of the disease.

Conclusions

The data in this paper indicated that WNT7A could be a potential oncogene in OSCC and identified a novel PI3K/AKT/WNT7A/β-catenin/MMP9 signaling for EGF-induced migration of OSCC cells.

Molecular biology of oral cavity squamous cell carcinoma

Oral cavity squamous cell carcinoma (OCSCC) is a heterogeneous and complex disease that arises due to dysfunction of multiple molecular signaling pathways. Recent advances in high-throughput genetic sequencing technologies coupled with innovative analytical techniques have begun to characterize the molecular determinants driving OCSCC. An understanding of the key molecular signaling networks underlying the initiation and progression of is essential for informing treatment of the disease. In this chapter, we discuss recent findings of key genes altered in OCSCC and potential treatments targeting these genes.

Prognostic Role of Epithelial-Mesenchymal Transition Markers "E-Cadherin, β-Catenin, ZEB1, ZEB2 and p63" in Bladder Carcinoma

Background

This study aimed to investigate the expression of epithelial-mesenchymal markers’ E-cadherin, β-catenin, zinc-finger E-box-binding homeobox 1 (ZEB1), zinc-finger E-box-binding homeobox 2 (ZEB2) and p63 in transitional cell carcinoma (TCC) and squamous cell carcinoma (SCC) variants of bladder carcinoma (BC) and their correlation with clinicopathological parameters of prognostic importance.

Methods

In this retrospective study, 91 patients were enrolled (66 with TCC and 25 with SCC). All patients had full clinical and follow-up data and available paraffin blocks. Immunohistochemical analysis was performed and correlated with clinicopathological factors.

Results

In TCC cases, reduced E-cadherin, β-catenin positivity and p63 expression rate were evident in the sitting of increased expression of ZEB1 and ZEB2. Patients with ZEB2 positive tumors were more likely to die compared to those with negative ZEB2 (P = 0.024). Moreover, in patients with muscle-invasive BCs, an intense p63 expression was associated with poor overall survival (OS) (P < 0.001). For patients with SCC, there was a reduction in E-cadherin and β-catenin positivity with elevated p63 expression and concomitant increased ZEB1 and ZEB2 expression. Poor prognosis was evident in association with reduced E-cadherin, positive nuclear β-catenin/reduced membranous β-catenin, ZEB1 and ZEB2 positive cases as well patients with elevated p63 expression (P < 0.001). TCC and SCC cases showed similar poor prognosis in association with elevated p63 expression (P < 0.001).

Conclusions

In both TCC and SCC variants, epithelial-mesenchymal transition (EMT) process is evident; however, its molecular mechanism shows some variations, specifically this notably different p63 expression pattern among two carcinoma variants with the similar impact of elevated p63 expression pattern on prognosis.

Expression of β-catenin and MMP-8 in gingival crevicular fluid and gingival tissue indicates the disease severity of patients with chronic periodontitis

The aim of the present study was to investigate the interaction among β-catenin, matrix metalloproteinase-8 (MMP-8) and severity in patients with chronic periodontitis. Both gingival crevicular fluid (GCF) and gingival tissue was collected from 21 healthy control individuals, 21 patients with moderate chronic periodontitis (mCP) and 23 patients with severe chronic periodontitis (sCP). The concentration of MMP-8 in GCF was detected via ELISA and the mRNA levels of β-catenin and MMP-8 in GCF and gingival tissue was detected via reverse transcription-quantitative PCR. The protein levels of β-catenin and MMP-8 in gingival tissue was detected using western blotting and the interaction between β-catenin and MMP-8 in gingival tissue was detected by co-immunoprecipitation. The expression of β-catenin and MMP-8 was significantly higher in the GCF and gingival tissue of patients with chronic periodontitis (mCP and sCP) compared with the control patients. Furthermore, the expression of β-catenin and MMP-8 in GCF and gingival tissue was positively correlated with the clinical attachment level. In addition, a positive interaction was identified between β-catenin and MMP-8, and the expression of β-catenin was positively correlated with the expression of MMP-8 in GCF and gingival tissue. The CGF and gingival tissue expression of β-catenin and MMP-8 may indicate disease severity in patients with chronic periodontitis.

Anti-EMT properties of CoQ0 attributed to PI3K/AKT/NFKB/MMP-9 signaling pathway through ROS-mediated apoptosis

Background

Breast cancer is the most prevalent cancer among women. In triple-negative breast cancer (TNBC) cells, a novel quinone derivative, coenzyme Q₀ (CoQ₀), promotes apoptosis and cell-cycle arrest. This study explored the anti-epithelial–mesenchymal transition (EMT) and antimetastatic attributes of CoQ₀ in TNBC (MDA-MB-231).

Methods

Invasion, as well as MTT assays were conducted. Lipofectamine RNAiMAX was used to transfect cells with β-catenin siRNA. Through Western blotting and RT-PCR, the major signaling pathways’ protein expressions were examined, and the biopsied tumor tissues underwent immunohistochemical and hematoxylin and eosin staining as well as Western blotting.

Results

CoQ₀ (0.5–2 μM) hindered tumor migration, invasion, and progression. Additionally, it caused MMP-2/− 9, uPA, uPAR, and VEGF downregulation. Furthermore, in highly metastatic MDA-MB-231 cells, TIMP-1/2 expression was subsequently upregulated and MMP-9 expression was downregulated. In addition, CoQ₀ inhibited metastasis and EMT in TGF-β/TNF-α-stimulated non-tumorigenic MCF-10A cells. Bioluminescence imaging of MDA-MB-231 luciferase–injected live mice demonstrated that CoQ₀ significantly inhibited metastasis of the breast cancer to the lungs and inhibited the development of tumors in MDA-MB-231 xenografted nude mice. Silencing of β-catenin with siRNA stimulated CoQ₀-inhibited EMT. Western blotting as well as histological analysis established that CoQ0 reduced xenografted tumor development because apoptosis induction, cell-cycle inhibition, E-cadherin upregulation, β-catenin downregulation, and metastasis and EMT regulatory protein modulation were observed.

Conclusions

CoQ₀ inhibited the progression of metastasis as well as EMT (in vitro and in vivo). The described approach has potential in treating human breast cancer metastasis.

Electronic supplementary material

The online version of this article (10.1186/s13046-019-1196-x) contains supplementary material, which is available to authorized users.

Regulation of Wnt/β-catenin pathway may be related to Regγ in benign epithelial odontogenic lesions

OBJECTIVES

The aim of this study was to analyze and compare the immunoexpressions of Regγ, Wnt-1, and β-catenin in ameloblastomas, adenomatoid odontogenic tumors (AOTs), and odontogenic keratocysts (OKCs).

STUDY DESIGN

Thirty solid ameloblastomas, 20 AOTs, and 30 OKCs were selected for analysis of the immunoexpression of Regγ, Wnt-1, and β-catenin. Each case was semiquantitatively evaluated in the epithelial component and in their different cellular compartments (membrane, cytoplasm, and nucleus).

RESULTS

Ameloblastomas displayed higher cytoplasmic and nuclear Regγ expression compared with AOTs and OKCs, as well as higher membrane and cytoplasmic Wnt-1 expression (P < .05). β-catenin membrane expression was higher in OKCs compared with ameloblastomas and AOTs (P < .05). Nuclear β-catenin expression was higher in ameloblastomas and AOTs than in OKCs (P < .05). Cytoplasmic and nuclear Regγ expression in AOTs were positively correlated with nuclear β-catenin expression (P < .05).

CONCLUSIONS

The marked expressions of Regγ, Wnt-1, and β-catenin suggest the participation of these proteins in the pathogenesis of the studied lesions. The greater expressions of Regγ, Wnt-1, and nuclear β-catenin in ameloblastomas may be related to their more aggressive behavior. Pro-tumor effects of nuclear β-catenin may be counterbalanced by inhibitory pathways in AOTs, justifying their low aggressiveness.

Antrodia salmonea suppresses invasion and metastasis in triple-negative breast cancer cells by reversing EMT through the NF-κB and Wnt/β-catenin signaling pathway

Antrodia salonea (AS), a fungus that is indigenous to Taiwan has been well known for its anti-cancer properties. We investigated the anti-metastatic and anti-epithelial-mesenchymal transition (EMT) properties of AS in TNBC cells. To determine their EMT and metastasis levels, in vitro wound healing, wound invasion, Western blotting, RT-PCR, luciferase activity and immunofluorescence assays were performed, while the in vivo anti-metastatic efficacy of AS was evaluated in BALB/c-nu mice through bioluminescence imaging, HE staining, and immunohistochemical staining. MDA-MB-231 cells, when treated with AS concentrations (25-100 μg/mL) resulted in significant reduction of invasion and migration as well as the downregulation of VEGF, uPAR, uPA and MMP-9 (inhibition of PI3K/AKT/NFκB pathways). AS treatment prevented morphological changes and reversed EMT through the upregulation of E-cadherin and the downregulation of N-cadherin, Slug, Twist, and Vimentin. Inhibition of Smad3 signaling pathway, downregulation of β-catenin pathway and upregulation of GSK3β expression were also observed while, suppression of metastasis and EMT in TGF-β1-stimulated non-tumorigenic MCF-10A cells was observed when treated with AS. Histological analysis confirmed that AS reduced tumor metastasis and upregulated E-cadherin expression in biopsied lung tissues. Our results indicated that AS exhibits anti-EMT and anti-metastatic activity, that could contribute to develop anticancer drugs against TNBC.

Biglycan Regulates MG63 Osteosarcoma Cell Growth Through a LPR6/β-Catenin/IGFR-IR Signaling Axis

Biglycan, a small leucine rich proteoglycan (SLRP), is an important participant in bone homeostasis and development as well as in bone pathology. In the present study biglycan was identified as a positive regulator of MG63 osteosarcoma cell growth (p ≤ 0.001). IGF-I was shown to increase biglycan expression (p ≤ 0.01), whereas biglycan-deficiency attenuated significantly both basal and IGF-I induced cell proliferation of MG63 cells (p ≤ 0.001; p ≤ 0.01, respectively). These effects were executed through the IGF-IR receptor whose activation was strongly attenuated (p ≤ 0.01) in biglycan-deficient MG63 cells. Biglycan, previously shown to regulate Wnt/β-catenin pathway, was demonstrated to induce a significant increase in β-catenin protein expression evident at cytoplasmic (p ≤ 0.01), membrane (p ≤ 0.01), and nucleus fractions in MG63 cells (p ≤ 0.05). As demonstrated by immunofluorescence, increase in β-catenin expression is attributed to co-localization of biglycan with the Wnt co-receptor low-density lipoprotein receptor-related protein 6 (LRP6) resulting in attenuated β-catenin degradation. Furthermore, applying anti-β-catenin and anti-pIGF-IR antibodies to MG-63 cells demonstrated a cytoplasmic and to the membrane interaction between these molecules that increased upon exogenous biglycan treatment. In parallel, the downregulation of biglycan significantly inhibited both basal and IGF-I-dependent ERK1/2 activation, (p ≤ 0.001). In summary, we report a novel mechanism where biglycan through a LRP6/β-catenin/IGF-IR signaling axis enhances osteosarcoma cell growth.

An update of knowledge on cortactin as a metastatic driver and potential therapeutic target in oral squamous cell carcinoma

Cortactin is a protein encoded by the CTTN gene, localized on chromosome band 11q13. As a result of the amplification of this band, an important event in oral carcinogenesis, CTTN is also usually amplified, promoting the frequent overexpression of cortactin. Cortactin enhances cell migration in oral cancer, playing a key role in the regulation of filamentous actin and of protrusive structures (invadopodia and lamellipodia) on the cell membrane that are necessary for the acquisition of a migratory phenotype. We also analyze a series of emerging functions that cortactin may exert in oral cancer (cell proliferation, angiogenesis, regulation of exosomes, and interactions with the tumor microenvironment). We review its molecular structure, its most important interactions (with Src, Arp2/3 complex, and SH3-binding partners), the regulation of its functions, and its specific oncogenic role in oral cancer. We explore the mechanisms of its overexpression in cancer, mainly related to genetic amplification. We analyze the prognostic implications of the oncogenic activation of cortactin in potentially malignant disorders and in head and neck cancer, where it appears to be relevant in the development of lymph node metastasis. Finally, we discuss its usefulness as a therapeutic target and suggest future research lines.

Prognostic and clinicopathological significance of cyclin D1 expression in oral squamous cell carcinoma: A systematic review and meta-analysis

OBJECTIVES

To evaluate the prognostic significance of cyclin D1 (CD1) overexpression in OSCC.

MATERIAL AND METHODS

We searched studies published before August 2017 (Pubmed, Embase, Web of Science, Scopus). We evaluated the quality of the studies included (Quality in Prognosis Studies [QUIPS] tool). The impact of CD1 overexpression on overall survival and disease-free survival, T status, N status, stage, and histological degree was meta-analyzed. We analyzed heterogeneity among studies, conducted sensitivity analyses, analyzed small-study effects, and conducted subgroup analyses.

RESULTS

31 studies (2942 patients) met inclusion criteria. Qualitative evaluation demonstrated that not all studies were performed with the same rigor, finding the greatest risk of bias in the study confounding domain. Quantitative evaluation showed that CD1 overexpression had a strong statistical association with worse overall survival (HR = 2.00, 95% CI = 1.59-2.51, p < 0.001), worse disease-free survival (HR = 1.46, 95% CI = 1.13-1.87, p = 0.003), higher T status (OR = 1.51, 95% CI = 1.07-2.13, p = 0.02), N+ status (OR = 2.16, 95% CI = 1.60-2.92, p < 0.001), advanced stage (OR = 1.44, 95% CI = 1.15-1.81, p = 0.002), and high histological grade (OR = 1.60, 95% CI = 1.12-2.29, p = 0.010). We observed heterogeneity in all parameters except for disease-free survival and clinical stage. We found effect of small studies on T and N status. The tonguel SCC subgroup showed the strongest association between CD1 overexpression and worse development. In addition, application of a cutoff point ≥10% tumor cells with nuclear CD1 expression maintained most of the significant associations reported.

CONCLUSIONS

These findings indicate that immunohistochemical assessment of CD1 overexpression may be useful as a prognostic biomarker for OSCC.

Emerging Insights into Wnt/β-catenin Signaling in Head and Neck Cancer

Head and neck cancer presents primarily as head and neck squamous cell carcinoma (HNSCC), a debilitating malignancy fraught with high morbidity, poor survival rates, and limited treatment options. Mounting evidence indicates that the Wnt/β-catenin signaling pathway plays important roles in the pathobiology of HNSCC. Wnt/β-catenin signaling affects multiple cellular processes that endow cancer cells with the ability to maintain and expand immature stem-like phenotypes, proliferate, extend survival, and acquire aggressive characteristics by adopting mesenchymal traits. A central component of canonical Wnt signaling is β-catenin, which balances its role as a structural component of E-cadherin junctions with its function as a transcriptional coactivator of numerous target genes. Recent genomic characterization of head and neck cancer revealed that while β-catenin is not frequently mutated in HNSCC, its activity is unchecked by more common mutations in genes encoding upstream regulators of β-catenin, NOTCH1, FAT1, and AJUBA. Wnt/β-catenin signaling affects a wide range epigenetic and transcriptional activities, mediated by the interaction of β-catenin with different transcription factors and transcriptional coactivators and corepressors. Furthermore, Wnt/β-catenin functions in a network with many signaling and metabolic pathways that modulate its activity. In addition to its effects on tumor epithelia, β-catenin activity regulates the tumor microenvironment by regulating extracellular matrix remodeling, fibrotic processes, and immune response. These multifunctional oncogenic effects of β-catenin make it an attractive bona fide target for HNSCC therapy.

Antrodia camphorata inhibits metastasis and epithelial-to-mesenchymal transition via the modulation of claudin-1 and Wnt/β-catenin signaling pathways in human colon cancer cells

ETHNOPHARMACOLOGICAL RELEVANCE

Antrodia camphorata (AC) is a well known traditional Chinese medicinal mushroom in Taiwan, has been used to treat various diseases including cancer.

MATERIALS AND METHODS

In this study, we investigated the anti-metastatic and anti-EMT properties of a fermented culture broth of AC in human colon SW480^claudin-1- and metastatic SW620^claudin-1+ cancer cells in vitro.

RESULTS

AC down-regulates claudin-1 and inhibits the proliferation and colony-formation abilities of both SW620^claudin-1+ and SW480^claudin-1- cells. In highly metastatic SW620^claudin-1+ cells, non-cytotoxic concentrations of AC significantly inhibited migration/invasion, accompanied by the down-regulation of MMP-2 and MMP-9 proteins. AC decreased nuclear translocation of Wnt/β-catenin through a GSK3β-dependent pathway. AC consistently inhibited EMT by up-regulating the epithelial and downregulating the mesenchymal marker proteins. In SW480^claudin-1- cells, AC suppressed migration/invasion potentially through the inhibition of the PI3K/AKT/NFκB signaling pathways without altering the expression levels of β-catenin and GSK3β proteins.

CONCLUSION

Altogether, this study demonstrates the anti-metastatic and anti-EMT activities of AC, which may contribute to the development of a chemopreventive agent for colon cancer.

Higher expression of WNT5A protein in oral squamous cell carcinoma compared with dysplasia and oral mucosa with a normal appearance

WNT5A is a secreted signaling protein that promotes migration and invasion of oral squamous cell carcinoma (OSCC) cells through activation of non‐canonical WNT signaling. Here, we examined expression of WNT5A, β‐catenin, and E‐cadherin by immunohistochemistry in 21 human diagnostic incision biopsies that each had regions of oral mucosa with a normal appearance adjacent to the affected tissue, dysplasia, and OSCC. We also investigated the effect of recombinant WNT5A (rWNT5A) on expression of the cell‐adhesion proteins E‐cadherin and β‐catenin by western blot analysis. No expression of WNT5A protein was present in oral mucosa with a normal appearance or in mild grade dysplasia. However, expression of WNT5A increased along with increasing grade of dysplasia, and the highest expression was detected in OSCCs. Expression of membranous β‐catenin and of E‐cadherin was lower, whereas expression of cytoplasmic β‐catenin was higher, in OSCCs than in non‐cancerous regions. However, there was no correlation between expression of WNT5A and expression of either β‐catenin or E‐cadherin. Furthermore, treatment of OSCC cells with rWNT5A had no effect on the expression of β‐catenin or E‐cadherin. Taken together with previous results, we conclude that WNT5A influences the progression of OSCC without affecting the canonical WNT/β‐catenin pathway and without down‐regulating E‐cadherin. WNT5A may have potential as a biological marker for malignant transformation of dysplasia to OSCC.

Suppression of the Growth and Invasion of Human Head and Neck Squamous Cell Carcinomas via Regulating STAT3 Signaling and the miR-21/β-catenin Axis with HJC0152

Signal transducer and activator of transcription 3 (STAT3) is involved in the tumor growth and metastasis of human head and neck squamous cell carcinoma (HNSCC) and is therefore a target with therapeutic potential. In this study, we show that HJC0152, a recently developed anticancer agent and a STAT3 signaling inhibitor, exhibits promising antitumor effects against HNSCC both in vitro and in vivo via inactivating STAT3 and downstream miR-21/β-catenin axis. HJC0152 treatment efficiently suppressed HNSCC cell proliferation, arrested the cell cycle at the G₀-G₁ phase, induced apoptosis, and reduced cell invasion in both SCC25 and CAL27 cell lines. Moreover, HJC0152 inhibited nuclear translocation of phosphorylated STAT3 at Tyr705 and decreased VHL/β-catenin signaling activity via regulation of miR-21. Loss of function of VHL remarkably compromised the antitumor effect of HJC0152 in both cell lines. In our SCC25-derived orthotopic mouse models, HJC0152 treatment significantly abrogated STAT3/β-catenin expression in vivo, leading to a global decrease of tumor growth and invasion. With its favorable aqueous solubility and oral bioavailability, HJC0152 holds the potential to be translated into the clinic as a promising therapeutic strategy for patients with HNSCC. Mol Cancer Ther; 16(4); 578-90. ©2017 AACR.

Identification of a combined biomarker for malignant transformation in oral submucous fibrosis

Background

Oral submucous fibrosis (OSF) is a chronic progressive disease of the oral cavity that is considered a common potentially malignant disorder in South Asia. Areca nut chewing is the main etiological factor, but its carcinogenic mechanism has yet to be proven. The purpose of this study was to identify the useful biomarkers in predicting high‐risk patients with OSF.

Methods

Thirty‐six cases of OSF and six cases of normal oral mucosa (NOM) were used for this study. Immunohistochemical staining was performed for Ki67, cyclin D1, p16, p53, β‐catenin, c‐Jun, c‐Met, and insulin‐like growth factor II mRNA‐binding protein 3 (IMP3). The expression patterns of NOM served as guidelines for the scoring system.

Results

The expression of Ki67, cyclin D1, c‐Met, IMP3, and β‐catenin showed a significant difference between OSF and NOM samples. The combined biomarkers of Ki67 and p16 showed significantly different expression between the transformation and non‐transformation groups. With discriminant analysis, we proposed a noble formula and cutoff value for predicting high‐risk patients with OSF.

Conclusion

The notable biomarkers in our present study were Ki67 and p16 showing significantly different expression levels between the transformation and non‐transformation groups. With the identification of high‐risk patients with OSF, we can expect to develop more intensive treatment modalities, leading to the reduction in cancer transformation rate from OSF.

Immunoexpression of Epithelial Mesenchymal Transition Proteins E-Cadherin, β-Catenin, and N-Cadherin in Oral Squamous Cell Carcinoma

Aims Epithelial mesenchymal transition (EMT) is a crucial process for acquisition of malignant phenotype, aggressiveness, and metastatic capacity in neoplasms. It is characterized by loss of epithelial markers and gain of mesenchymal markers. Studies on EMT and its potential association with the histological grading are sparse in oral squamous cell carcinoma (OSCC). This study aims to evaluate the expression of EMT-associated proteins-E-cadherin, β-catenin, and N-cadherin-in different grades of OSCC. Methodology In all, 60 cases of OSCC further subdivided into 20 cases each of well-, moderately, and poorly differentiated OSCCs were stained immunohistochemically with E-cadherin, β-catenin, and N-cadherin antibodies. The differences in the expression were evaluated using χ² and Fisher exact tests, whereas Spearman's correlation was used to analyze the correlation between the markers. Results A reduced E-cadherin expression noted in 40% of the OSCCs was associated with reduced β-catenin expression in 66.6% of the cases and increase in the expression of mesenchymal N-cadherin seen in 80% of cases. This expression pattern demonstrated a significant association with histological grades. A membrane to cytoplasmic shift of E-cadherin (73.3%) and β-catenin (78.3%) increased with histological grade. A negative correlation was observed with the E-cadherin and N-cadherin localization, though it did not reach statistical significance. Conclusion OSCC tissues had high levels of EMT phenotype as compared with the normal oral mucosa. This phenotype was characterized by reduced E-cadherin and β-catenin expression and overexpression of N-cadherin. Aberrant localization of the studied proteins was a hallmark for depicting EMT.

Nimbolide, a neem limonoid inhibits Phosphatidyl Inositol-3 Kinase to activate Glycogen Synthase Kinase-3β in a hamster model of oral oncogenesis

Glycogen synthase kinase-3β (GSK-3β), a serine/threonine kinase is frequently inactivated by the oncogenic signalling kinases PI3K/Akt and MAPK/ERK in diverse malignancies. The present study was designed to investigate GSK-3β signalling circuits in the 7,12-dimethylbenz[a]anthracene (DMBA)-induced hamster buccal pouch (HBP) carcinogenesis model and the therapeutic potential of the neem limonoid nimbolide. Inactivation of GSK-3β by phosphorylation at serine 9 and activation of PI3K/Akt, MAPK/ERK and β-catenin was associated with increased cell proliferation and apoptosis evasion during stepwise evolution of HBP carcinomas. Administration of nimbolide inhibited PI3K/Akt signalling with consequent activation of GSK-3β thereby inducing trafficking of β-catenin away from the nucleus and enhancing the expression of miR-126 and let-7. Molecular docking studies confirmed interaction of nimbolide with PI3K, Akt, ERK and GSK-3β. Furthermore, nimbolide attenuated cell proliferation and induced apoptosis as evidenced by increased p-cyclin D1^Thr286 and pro-apoptotic proteins. The present study has unravelled aberrant phosphorylation as a key determinant for oncogenic signalling and acquisition of cancer hallmarks in the HBP model. The study has also provided mechanistic insights into the chemotherapeutic potential of nimbolide that may be a useful addition to the armamentarium of natural compounds targeting PI3K for oral cancer treatment.

The potential role of CacyBP/SIP in tumorigenesis

Calcyclin-binding protein/Siah-1-interacting protein (CacyBP/SIP) was initially described as a binding partner of S100A6 in the Ehrlich ascites tumor cells and later as a Siah-1-interacting protein. This 30 kDa protein includes three domains and is involved in cell proliferation, differentiation, cytoskeletal rearrangement, and transcriptional regulation via binding to various proteins. Studies have also shown that the CacyBP/SIP is a critical protein in tumorigenesis. But, its promotion or suppression of cancer progression may depend on the cell type. In this review, the biological characteristics and target proteins of CacyBP/SIP have been described. Moreover, the exact role of CacyBP/SIP in various cancers is discussed.

Mouth Cancer for Clinicians Part 6: Potentially Malignant Disorders

A MEDLINE search early in 2015 revealed more than 250,000 papers on head and neck cancer; over 100,000 on oral cancer; and over 60,000 on mouth cancer. Not all publications contain robust evidence. We endeavour to encapsulate the most important of the latest information and advances now employed in practice, in a form comprehensible to healthcare workers, patients and their carers. This series offers the primary care dental team, in particular, an overview of the aetiopathogenesis, prevention, diagnosis and multidisciplinary care of mouth cancer, the functional and psychosocial implications, and minimization of the impact on the quality of life of patient and family.

CLINICAL RELEVANCE

This article offers the dental team an overview of oral potentially malignant disorders.

The Role of Wnt Signaling in Squamous Cell Carcinoma

Aberrant Wnt signaling pathway is a common feature of tumors and also plays important roles in tumor progression and metastasis of many cancer types. Various lines of evidence suggest that genetic defects affect Wnt pathway components, as well as epigenetic mechanisms that modulate the suppressors of Wnt pathway in oral squamous cell carcinoma. Recently, the newly discovered microRNAs are important molecular regulators in gene expression through transcription and translation repression. They play fundamental roles in a wide spectrum of biological functions, including cancer. In this review, we aim to accumulate recent research findings on the roles of Wnt/β-catenin signaling and discuss how microRNAs affect Wnt/β-catenin signaling in oral squamous cell carcinoma tumorigenesis. Apparently, investigations into the role of microRNAs with regard to the Wnt pathway in oral squamous cell carcinoma may help in the development of better strategies for tumor treatment.

Deregulation of secreted frizzled-related proteins is associated with aberrant β-catenin activation in the carcinogenesis of oral submucous fibrosis

Secreted frizzled-related proteins (SFRPs), the first identified Wnt antagonists, have been well recognized as tumor suppressors in multiple human cancers through suppressing the Wnt/β-catenin pathway. To better elucidate the mechanisms of SFRPs involved in the carcinogenesis of oral submucous fibrosis (OSF), one of the precancerous lesions of oral squamous cell carcinoma (OSCC), we investigated expression and localization of SFRP1, SFRP5, and β-catenin in normal oral epithelium, OSF, and OSCC tissues. We found that SFRP1 and SFRP5 were readily expressed in normal oral mucous tissues but gradually decreased in OSF early, moderately advanced, and advanced tissues and rarely expressed in OSCC tissues. We found the changes of SFRP1 localization and SFRP5 localization from nucleus to cytoplasm in the carcinogenesis of OSF. There is a significant association among reduced SFRP1, SFRP5, and cytoplasmic/nuclear β-catenin expression, which is correlated with higher tumor grade and stage of OSCC. We further found that SFRP1 and SFRP5 were frequently methylated in OSCC cases with betel quid chewing habit but not in normal oral mucous and different stages of OSF tissues, suggesting that methylation of SFRP1 and SFRP5 is tumor specific in the carcinogenesis of OSF. Taken together, our data demonstrated that reduced SFRP1 and SFRP5 by promoter methylation could lead to cytoplasmic/nuclear accumulation of β-catenin and tumor progression. The changes of SFRPs and β-catenin localization, as well as SFRPs' methylation, could be useful predictors or biomarkers of OSF malignant progression and prognosis.

Novel robust biomarkers for human bladder cancer based on activation of intracellular signaling pathways

We recently proposed a new bioinformatic algorithm called OncoFinder for quantifying the activation of intracellular signaling pathways. It was proved advantageous for minimizing errors of high-throughput gene expression analyses and showed strong potential for identifying new biomarkers. Here, for the first time, we applied OncoFinder for normal and cancerous tissues of the human bladder to identify biomarkers of bladder cancer. Using Illumina HT12v4 microarrays, we profiled gene expression in 17 cancer and seven non-cancerous bladder tissue samples. These experiments were done in two independent laboratories located in Russia and Canada. We calculated pathway activation strength values for the investigated transcriptomes and identified signaling pathways that were regulated differently in bladder cancer (BC) tissues compared with normal controls. We found, for both experimental datasets, 44 signaling pathways that serve as excellent new biomarkers of BC, supported by high area under the curve (AUC) values. We conclude that the OncoFinder approach is highly efficient in finding new biomarkers for cancer. These markers are mathematical functions involving multiple gene products, which distinguishes them from “traditional” expression biomarkers that only assess concentrations of single genes.

Anticancer activity of pyrithione zinc in oral cancer cells identified in small molecule screens and xenograft model: Implications for oral cancer therapy

Oral squamous cell carcinoma (OSCC) patients diagnosed in late stages have limited chemotherapeutic options, underscoring the great need for development of new anticancer agents for more effective disease management. We aimed to identify novel anticancer agents for OSCC using quantitative high throughput assays for screening six chemical libraries consisting of 5170 small molecule inhibitors. In depth characterization resulted in identification of pyrithione zinc (PYZ) as the most effective cytotoxic agent inhibiting cell proliferation and inducing apoptosis in OSCC cells in vitro. Further, treatment with PYZ reduced colony forming, migration and invasion potential of oral cancer cells in a dose-dependent manner. PYZ treatment also led to altered expression of several key components of the major signaling pathways including PI3K/AKT/mTOR and WNT/β-catenin in OSCC cells. In addition, treatment with PYZ also reduced expression of 14-3-3ζ, 14-3-3σ, cyclin D1, c-Myc and pyruvate kinase M2 (PKM2), proteins identified in our earlier studies to be involved in development and progression of OSCCs. Importantly, PYZ treatment significantly reduced tumor xenograft volume in immunocompromised NOD/SCID/Crl mice without causing apparent toxicity to normal tissues. Taken together, we demonstrate in vitro and in vivo efficacy of PYZ in OSCC. In conclusion, we identified PYZ in HTS assays and demonstrated in vitro and in vivo pre-clinical efficacy of PYZ as a novel anticancer therapeutic candidate in OSCC.

Salivary microRNAs in oral cancer

OBJECTIVE

This study investigated the use of three salivary microRNAs (miRNA-21, miRNA-184, and miRNA-145) as possible markers for malignant transformation in oral mucosal lesions.

MATERIALS AND METHODS

Salivary whole unstimulated samples were collected from a study group of 100 subjects, consisting of 20 clinically healthy controls, 40 patients with oral potentially malignant disorders (PMDs) [20 with dysplastic lesions and 20 without dysplasia], 20 with biopsy-confirmed oral squamous cell carcinoma (OSCC), and 20 with recurrent aphthous stomatitis (RAS) as disease controls. Total RNA was isolated and purified from saliva samples using the microRNA Isolation Kit (Qiagen, UL). miRNA expression analysis was performed using qRT-PCR (Applied Biosystems).

RESULTS

There was a highly significant increase in salivary miRNA-21 and miRNA-184 in OSCC and PMD (with and without dysplasia) when compared to healthy and disease controls (P < 0.001). Conversely, miRNA-145 levels showed a highly significant decrease in OSCC and PMD overall (P < 0.001). RAS cases showed no significant difference from normal controls in any measured miRNA (P > 0.05). The only microRNA to discriminate between OSCC and PMD with dysplasia was miRNA-184. When receiver operating characteristic curves were designed for the three miRNAs, cutoff points delineating the occurrence of malignant change were a fourfold increase in miRNA-21 with specificity 65% and sensitivity 65%, a 0.6 decrease in miRNA-145, with specificity 70% and sensitivity 60%, and a threefold increase of miRNA-184, with specificity 75% and sensitivity 80%. Calculating the area under the curve revealed that miRNA-184 was the only one among the studied miRNAs that provided good diagnostic value.

CONCLUSION

Salivary determination of the miRNAs tested might furnish a noninvasive, rapid adjunctive aid for revealing malignant transformation in oral mucosal lesions, particularly miRNA-184.