Association of differential β-catenin expression with Oct-4 and Nanog in oral squamous cell carcinoma and their correlation with clinicopathological factors and prognosis

GALNT6, GALNT14, and Gal-3 in association with GDF-15 promotes drug resistance and stemness of breast cancer via β-catenin axis

N-acetylgalactosaminyltransferases (GALNTs) are a polypeptide responsible for aberrant glycosylation in breast cancer (BC), but the mechanism is unclear. In this study, expression levels of GALNT6, GALNT14, and Gal-3 were assessed in BC, and their association with GDF-15, β-catenin, stemness (SOX2 and OCT4), and drug resistance marker (ABCC5) was evaluated. Gene expression of GALNT6, GALNT14, Gal-3, GDF-15, OCT4, SOX2, ABCC5, and β-catenin in tumor and adjacent non-tumor tissues (n = 30) was determined. The same was compared with GEO-microarray datasets. A significant increase in the expression of candidate genes was observed in BC tumor compared to adjacent non-tumor tissue; and in pre-therapeutic patients compared to post-therapeutic. GALNT6, GALNT14, Gal-3, and GDF-15 showed positive association with β-catenin, SOX2, OCT4, and ABCC5 and were significantly associated with poor Overall Survival. Our findings were also validated via in silico analysis. Our study suggests that GALNT6, GALNT14, and Gal-3 in association with GDF-15 promote stemness and intrinsic drug resistance in BC, possibly by β-catenin signaling pathway.

Estrogen-Related Receptor Alpha (ERRα) Promotes Cancer Stem Cell-Like Characteristics in Breast Cancer

Cancer stem cells drive tumor initiation, invasion, metastasis and recurrence. In the present study, we have evaluated the role of ERRα in the maintenance of breast cancer stem cells (BCSCs) using breast cancer cell lines. The inhibition of ERRα with the inverse agonist, XCT-790, or the knockdown of ERRα in breast cancer cells significantly reduced the mammosphere formation efficiency and mammosphere size along with a significant reduction in the CD44+/CD24- BCSCs. Treatment with XCT-790 significantly downregulated expression of the transcription factors involved in stem cell maintenance such as Oct4, Klf4, Sox2, Nanog and c-Myc in the mammosphere forming stem cells of MCF7 and MDA-MB-231. In addition, XCT-790 induced cell cycle arrest and apoptosis in the mammosphere-forming cells. The knockdown or inhibition of ERRα downregulated the expression of Notch1 and β-catenin, whereas the overexpression of ERRα in MCF7 cells upregulated the expression of these proteins. Moreover, the inhibition of ERRα synergistically enhanced the efficacy of paclitaxel in inhibiting the BCSCs. These results show that ERRα is crucial for the maintenance of BCSCs and suggest that ERRα could be a potential target for breast cancer treatment.

High NANOG expression correlates with worse patients' survival in esophageal adenocarcinoma

BACKGROUND

Patients diagnosed with esophageal cancer demonstrate a low overall survival even despite the established multimodal therapy as the current standard of care. Therefore, further biomarkers for patients with high-risk and additional therapy options are needed. NANOG is a transcription factor, which can be found in stem cells and is known to support tumorigenesis.

METHODS

Six hundred sixty patients with esophageal adenocarcinoma, who were operated at the University of Cologne with a curative intent, were included. Immunohistochemical stainings for NANOG were performed. The study population was divided into NANOG-positive and -negative subgroups.

RESULTS

Positive NANOG expression correlates significantly with worse overall survival (p = 0.002) and could be confirmed as an independent risk factor for worse patient survival in multivariate analysis (HR = 1.40, 95%CI = 1.09-1.80, p = 0.006). This effect could be detected in the subgroup of primarily operated patients, but not in patients after neoadjuvant therapy.

CONCLUSIONS

We describe a NANOG-positive subgroup of patients with esophageal cancer, who exhibit worse overall survival in a large patient cohort. This discovery suggests the potential use of NANOG as a biomarker for both intensified therapy and stricter follow-up regimes. Additionally, NANOG-positive stem cell-like cancer cells could be used as a new antitumoral treatment target if validated in mechanistic and clinical studies.

Prognostic histological markers in oral tongue squamous cell carcinoma patients treated with (chemo)radiotherapy

Treatment of oral tongue squamous cell carcinoma (OTSCC) frequently includes surgery with postoperative radiotherapy (RT) or chemoradiotherapy (CRT). Resistance to RT or CRT remains a major clinical challenge and highlights the need to identify predictive markers for it. We included 71 OTSCC patients treated with surgery combined with RT or CRT. We evaluated the association between tumor budding, tumor-stroma ratio (TSR), depth of invasion (DOI), tumor-infiltrating lymphocytes (TILs), hypoxia-inducible factor-1alpha (HIF-1alpha) expression, octamer-binding transcription factor 4 (OCT4) expression, high-endothelial venules (HEVs), and disease-free survival (DFS) using uni- and multivariate analyses. No significant association was observed between the different histological and molecular markers (TSR, DOI, TILs, HEV, HIF-1alph, OCT4) and DFS. However, an associative trend between DOI, budding, and DFS was noted. Further studies with larger cohorts are needed to explore the prognostic value of DOI and budding for OTSCC patients treated with postoperative RT or CRT.

[Cancer stem cells in oral squamous cell carcinoma. Literature review]

Objective

To perform a literature review on oral squamous cell carcinoma, the presence of cancer stem cells; their association with the course of the disease and therapeutic applications.

Methods

: A search was performed in the PubMed database by entering the following algorithm: ((((neoplastic stem cells [MeSH Terms ]) OR (Cancer stem cells [Text Word ])) AND (Squamous Cell Carcinoma of Head and Neck [MeSH Terms])) AND (Oral squamous cell carcinoma [Text Word ]), to find articles in english published between 2012 and 2022. The PRISMA diagram was used to identify and select the articles.

Results

A result of 49 articles was obtained; of which 27 were chosen according to the title and abstract in their association with the topic. In addition, 8 additional articles suggested by their relationship with the information previously searched were included. In total, 35 articles were evaluated. There has been found that tumoral cells in squamous oral carcinoma are heterogeneous since they include cancer stem cells wich possess characteristics of stem and neoplasic cells; which possess characteristics of stem cells as well as neoplastic cells; they have been associated with disease progression, recurrence, and metastasis and have been considered to be a key mechanism of therapy failure.

Conclusions

The expression of stem cell markers in oral squamous cell carcinomas has been demonstrated and has contributed to their identification in oral squamous cell carcinomas and has been implicated in the behavior of cancer cells. New therapeutic measures aimed at eliminating cancer stem cells have been proposed and developed.

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.

Stem Cell Markers CXCR-4 and CD133 Predict Aggressive Phenotype and Their Double Positivity Indicates Poor Prognosis of Oral Squamous Cell Carcinoma

Simple Summary

Oral cancer is one of the most frequent malignancies in the world, with a poor prognosis. The absence of accurate biomarkers for predicting oral cancer progression is the primary cause of treatment failures. Multiple studies have shown that cancer stem cells play a critical role in tumor growth and chemo resistance. We uncovered, for the first time, the importance of combinatorial expression of stem cell related molecules CXCR-4 and CD-133 as possible biomarkers to predict poor prognosis of oral squamous cell carcinoma. The findings will aid in the identification of high-risk cases in order to provide appropriate therapy.

Abstract

The activation of the SDF-1/CXCR-4 pathway is crucial for the invasion and metastasis of oral cancer cells. The CXCR-4 positive cells possess stem cell characteristics and express the cancer stem cell marker, CD133, in tumors of colon and pancreas. Despite several studies, the co-expression of CXCR-4 and CD133 and its significance is still largely unknown in oral cancer. Therefore, we aimed to investigate the impact of CXCR-4 and CD133 double positivity in the prognosis of oral cancer. The significance of PKC-δ, one of the key signaling molecules that regulates CXCR-4, was also analyzed. Immunohistochemistry and double immunofluorescence was used to investigate the co-localization of CXCR-4, PKC-δ and CD133 in the human tissues and cell lines of oral squamous cell carcinoma. The expression of CXCR-4, PKC-δ and CD133 were found to be higher in poorly differentiated and lymph node metastasis-positive cases. Interestingly, CXCR-4 positive cells showed positive staining for PKC-δ and CD133 in oral cancer tissue and cell lines. Moreover, CXCR-4+/CD133+ and CXCR-4+/PKC-δ+ double positive cases have the worst survival. We discovered, for the first time, that patients with expression of both CXCR-4 and CD133 have a lower survival rate, and CXCR-4+/CD133+, as well as CXCR-4+/PKC-δ+ double positivity, can be utilized to predict poor prognosis. CXCR-4, PKC-δ and CD133 might regulate aggressiveness and invasion of oral cancer cells.

Heterogeneity of Cancer Stem Cells in Tumorigenesis, Metastasis, and Resistance to Antineoplastic Treatment of Head and Neck Tumours

The discovery of a small subset of cancer cells with self-renewal properties that can give rise to phenotypically diverse tumour populations has shifted our understanding of cancer biology. Targeting cancer stem cells (CSCs) is becoming a promising therapeutic strategy in various malignancies, including head and neck squamous cell carcinoma (HNSCC). Diverse sub-populations of head and neck cancer stem cells (HNCSCs) have been identified previously using CSC specific markers, the most common being CD44, Aldehyde Dehydrogenase 1 (ALDH1), and CD133, or by side population assays. Interestingly, distinct HNCSC subsets play different roles in the generation and progression of tumours. This article aims to review the evidence for a role of specific CSCs in HNSCC tumorigenesis, invasion, and metastasis, together with resistance to treatment.

Expression of the cancer stem cell marker OCT4 is associated with worse prognosis and survival in cutaneous melanoma

Cutaneous melanoma has an aggressive clinical presentation, showing rapid rate of growth and metastatic dissemination due to the permanence of cancer stem cells. The present study was to evaluate the expression of the self-renewal regulatory factor and the clinical significance of the transcription factor OCT4 in melanoma. Melanoma tissues were stained by immunohistochemistry and the correlation between the expression of this marker was determined through clinical-pathological variables and survival outcomes. Positive expression of nuclear and cytoplasmic OCT4 was observed in 49% and 41.2% of cases, respectively. The positive expression of nuclear OCT4 in melanoma was significantly associated with prognostic factors, such as Breslow depth, Clark's level, ulceration and metastasis. Survival of patients was 56% compared to positive nuclear OCT4 expression and 94.2% when compared to the low expression of the gene. Nuclear OCT4 positive genotype indicated aggressive tumor behavior with a worse clinical outcome, which indicates OCT4 as a useful biomarker in the prognosis of melanoma.

Immunohistochemical expression of OCT4 and CD44 in major and minor salivary gland neoplasms

The aim of this study was to identify tumor parenchyma cells exhibiting immunohistochemical profile of stem cells by evaluating the immunoreactivity of OCT4 and CD44 in a number of cases of salivary gland neoplasms. The sample consisted of 20 pleomorphic adenomas, 20 mucoepidermoid carcinomas, and 20 adenoid cystic carcinomas located in major and minor salivary glands. The expression of OCT4 and CD44 was evaluated by the percentage of positive cells and the intensity of expression. All studied cases showed positive expression of OCT4 and CD44 and higher values than the control groups. For OCT4, luminal and non-luminal cells were immunostained in the case of pleomorphic adenomas and adenoid cystic carcinomas. Moreover, the immunoreactivity of CD44 was particularly evident in the non-luminal cells of these lesions. In mucoepidermoid carcinomas, there was immunoreactivity for both markers in squamous and intermediate cells and absence of staining in mucous cells. For both markers, a significantly higher immunostaining was verified in neoplasms located in the major salivary glands compared with lesions in minor salivary glands (p<0.001). In the total sample and in minor salivary glands, malignant neoplasms exhibited higher immunoreactivity for OCT4 than pleomorphic adenoma. A significant moderate positive correlation (r = 0.444 and p ≤ 0.001) was found between OCT4 and CD44 immunoexpression in the total sample. The high expression of OCT4 and CD44 may indicate that these proteins play an important role in identifying tumor stem cells.

MicroRNAs and Long Non-Coding RNAs as Regulators of NANOG Expression in the Development of Oral Squamous Cell Carcinoma

NANOG is a stem cell transcription factor that is believed to play an important role in the development of oral squamous cell carcinoma (OSCC), but there is limited data regarding the role of long non-coding RNAs (lncRNAs) and microRNAs (miRNAs) in the regulation of NANOG expression. We therefore analyzed expression of NANOG, NANOG-regulating miRNAs and lncRNAs in OSCC cancerogenesis, using oral biopsy samples from 66 patients including normal mucosa, dysplasia, and OSCC. Expression analysis of NANOG, miR-34a, miR-145, RoR, SNHG1, AB209630, and TP53 was performed using qPCR and immunohistochemistry for NANOG protein detection. NANOG protein showed no staining in normal mucosa, very weak in low-grade dysplasia, and strong staining in high-grade dysplasia and OSCC. NANOG, miR-145, RoR, and SNHG1 showed up-regulation, TP53 and miR-34a showed down-regulation, and AB209630 showed variable expression during cancerogenesis. NANOG mRNA was up-regulated early in cancerogenesis, before strong protein expression can be detected. NANOG was in correlation with miR-145 and RoR. Our results suggest that miRNAs and lncRNAs, particularly miR-145 and RoR, might be important post-transcription regulatory mechanisms of NANOG in OSCC cancerogenesis. Furthermore, NANOG protein detection has a diagnostic potential for oral high-grade dysplasia, distinguishing it from low-grade dysplasia and non-neoplastic reactive lesions.

Diagnostic significance and carcinogenic mechanism of pan-cancer gene POU5F1 in liver hepatocellular carcinoma

BACKGROUND

The prognostic and clinicopathological significance of POU Class 5 Homeobox 1 (POU5F1) among various cancers are disputable heretofore. The diagnostic value and functional mechanism of POU5F1 in liver hepatocellular carcinoma (LIHC) have not been studied thoroughly.

METHODS

An integrative strategy of meta-analysis, bioinformatics, and wet-lab approach was used to explore the diagnostic and prognostic significance of POU5F1 in various types of tumors, especially in LIHC. Meta-analysis was utilized to investigate the impact of POU5F1 on prognosis and clinicopathological parameters in various cancers. The expression level and diagnostic value of POU5F1 were assessed by qPCR in plasma collected from LIHC patients and controls. The correlation between POU5F1 and tumor infiltrating immune cells (TIICs) in LIHC was evaluated by CIBERSORT. Gene set enrichment analysis (GSEA) was performed based on TCGA. Hub genes and related pathways were identified on the basis of co-expression genes of POU5F1.

RESULTS

Elevated POU5F1 was associated with poor OS, DFS, RFS, and DSS in various cancers. POU5F1 was confirmed as an independent risk factor for LIHC and correlated with tumor occurrence, stage, and invasion depth. The combination of POU5F1 and AFP in plasma was with high diagnostic validity (AUC = 0.902, p < .001). Specifically, the level of POU5F1 was correlated with infiltrating levels of B cells, T cells, dendritic cells, and monocytes in LIHC. GSEA indicated that POU5F1 participated in multiple cancer-related pathways and cell proliferation pathways. Moreover, CBX3, CCHCR1, and NFYC were filtered as the central hub genes of POU5F1.

CONCLUSION

Our study identified POU5F1 as a pan-cancer gene that could not only be a prognostic and diagnostic biomarker in various cancers, especially in LIHC, but functionally carcinogenic in LIHC.

Epithelial-to-mesenchymal transition in oral squamous cell carcinoma: Challenges and opportunities

Oral squamous cell carcinoma (OSCC) is the most common malignancy representing 90% of all forms of oral cancer worldwide. Although great efforts have been made in the past decades, the 5-year survival rate of OSCC patients is no more than 60% due to tumor metastasis and subsequent recurrence. The metastasis from the primary site is due to a complex process known as epithelial-to-mesenchymal transition (EMT). During the EMT, epithelial cells gradually acquire the structural and functional characteristics of mesenchymal cells, leading to the upregulation of cell migration and the promotion of tumor cell dissemination. Therefore, EMT attracted broad attention due to its close relationship with cancer invasion and metastasis. Therefore, in the present review, an extensive description of the current research on OSCC and the role of EMT in this cancer type is provided, including diverse EMT markers, regulatory networks and crucial EMT-inducing transcription factors in OSCC. Moreover, a brief summary was made regarding the current application of EMT-correlated indexes in the prognostic analysis of OSCC patients, and the potential therapeutic approaches against OSCC and difficulties in the development of an effective anti-EMT treatment are discussed. Our aim is to provide novel insights to develop new strategies to combat OSCC by targeting EMT.

Signaling pathways and microRNAs, the orchestrators of NANOG activity during cancer induction

Cancer stem cells (CSCs) are a small part of cancer cells inside the tumor that have similar characteristics to normal stem cells. CSCs stimulate tumor initiation and progression in a variety of cancers. Several transcription factors such as NANOG, SOX2, and OCT4 maintain the characteristics of CSCs and their upregulation is seen in many malignancies resulting in increased metastasis, invasion, and recurrence. Among these factors, NANOG plays an important role in regulating the self-renewal and pluripotency of CSCs and the clinical significance of NANOG has been suggested as a marker of CSCs in many cancers. The up and down-regulation of NANOG is associated with several important signaling pathways, including JAK/STAT, Wnt/β-catenin, Notch, TGF-β, Hedgehog, and several microRNAs (miRNAs). In this review, we will investigate the function of NANOG in CSCs and the molecular mechanism of its regulation by signaling pathways and miRNAs. We will also investigate targeting NANOG with different techniques, which is a promising treatment strategy for cancer treatment.

Alternation of β-catenin and CD44s Immunoexpression in Different Histopathological Grades of Oral Squamous Cell Carcinoma

OBJECTIVE

Cell-cell adhesion molecules play an essential role in cell growth and differentiation. β-catenin and CD44s are two adhesion molecules which their expression changes are correlated to loss of differentiation and gain of an invasive epithelial phenotype. Oral squamous cell carcinoma (OSCC) is the most common malignancy of oral cavity. Aim of this study was to compare β-catenin and CD44s expression in different histopathological grades of OSCC.

METHODS

β-catenin and CD44s expression were evaluated in 10 well differentiated OSCC (group A) and 10 moderately/poorly differentiated OSCC (group B) using immunohistochemistry.

RESULTS

β-catenin membranous and nuclear/cytoplasmic expression were significantly different between groups A and B. CD44s membranous expression was insignificant amongst the two groups.

CONCLUSION

Expression of β-catenin and CD44s alter in different histopathological grades of OSCC. It seems that more rate of aberrant cytoplasmic and/nuclear expression and less membranous expression of β-catenin can lead to significantly lower degree of cell differentiation in OSCC. <br />.

The Significance of the Dysregulation of Canonical Wnt Signaling in Head and Neck Squamous Cell Carcinomas

The knowledge about the molecular alterations which are found in head and neck squamous cell carcinomas (HNSCC) has much increased in recent years. However, we are still awaiting the translation of this knowledge to new diagnostic and therapeutic options. Among the many molecular changes that are detected in head and neck cancer, the abnormalities in several signaling pathways, which regulate cell proliferation, cell death and stemness, seem to be especially promising with regard to the development of targeted therapies. Canonical Wnt signaling is a pathway engaged in the formation of head and neck tissues, however it is not active in adult somatic mucosal cells. The aim of this review paper is to bring together significant data related to the current knowledge on the mechanisms and functional significance of the dysregulation of the Wnt/β-catenin pathway in head and neck tumors. Research evidence related to the role of Wnt signaling activation in the stimulation of cell proliferation, migration and inhibition of apoptosis in HNSCC is presented. Moreover, its role in promoting stemness traits in head and neck cancer stem-like cells is described. Evidence corroborating the hypothesis that the Wnt signaling pathway is a very promising target of novel therapeutic interventions in HNSCC is also discussed.

NANOG expression in human development and cancerogenesis

NANOG is an important stem cell transcription factor involved in human development and cancerogenesis. Its expression is complex and regulated on different levels. Moreover, NANOG protein might regulate hundreds of target genes at the same time. NANOG is crucial for preimplantation development phase and progressively decreases during embryonic stem cells differentiation, thus regulating embryonic and fetal development. Postnatally, NANOG is undetectable or expressed in very low amounts in the majority of human tissues. NANOG re-expression can be detected during cancerogenesis, already in precancerous lesions, with increasing levels of NANOG in high grade dysplasia. NANOG is believed to enable cancer cells to obtain stem-cell like properties, which are believed to be the source of expanding growth, tumor maintenance, metastasis formation, and tumor relapse. High NANOG expression in cancer is frequently associated with advanced stage, poor differentiation, worse overall survival, and resistance to treatment, and is therefore a promising prognostic and predictive marker. We summarize the current knowledge on the role of NANOG in cancerogenesis and development, including our own experience. We provide a critical overview of NANOG as a prognostic and diagnostic factor, including problems regarding its regulation and detection.

The Emerging Role of NANOG as an Early Cancer Risk Biomarker in Patients with Oral Potentially Malignant Disorders

NANOG, a key regulator of pluripotency and self-renewal in embryonic and adult stem cells, is frequently overexpressed in multiple cancers, including oral squamous cell carcinoma (OSCC). It has been frequently associated with poor outcomes in epithelial cancers, and recently implicated in laryngeal tumorigenesis. On this basis, we investigated the role of NANOG protein expression as an early cancer risk biomarker in oral potentially malignant disorders (OPMD), and the impact on prognosis and disease outcomes in OSCC patients. NANOG expression was evaluated by immunohistochemistry in 55 patients with oral epithelial dysplasia, and 125 OSCC patients. Correlations with clinical and follow-up data were assessed. Nuclear NANOG expression was detected in 2 (3.6%) and cytoplasmic NANOG expression in 9 (16.4%) oral dysplasias. NANOG expression increased with the grade of dysplasia. Cytoplasmic NANOG expression and the histopathological grading were significantly correlated with oral cancer risk, although dysplasia grading was the only significant independent predictor of oral cancer development in multivariate analyses. Cytoplasmic NANOG expression was also detected in 39 (31%) OSCC samples. Positive NANOG expression was significantly associated with tobacco and alcohol consumption, and was more frequent in pN0 tumors, early I-II stages. These data unveil the clinical relevance of NANOG in early stages of OSCC tumorigenesis rather than in advanced neoplastic disease. NANOG expression emerges as an early predictor of oral cancer risk in patients with OPMD.

Cancer Stem Cells in Head and Neck Squamous Cell Carcinoma: Identification, Characterization and Clinical Implications

Head and neck squamous cell carcinoma (HNSCC) is the sixth most commonly diagnosed cancer worldwide. Despite advances in the treatment management, locally advanced disease has a poor prognosis, with a 5-year survival rate of approximately 50%. The growth of HNSCC is maintained by a population of cancer stem cells (CSCs) which possess unlimited self-renewal potential and induce tumor regrowth if not completely eliminated by therapy. The population of CSCs is not only a promising target for tumor treatment, but also an important biomarker to identify the patients at risk for therapeutic failure and disease progression. This review aims to provide an overview of the recent pre-clinical and clinical studies on the biology and potential therapeutic implications of HNSCC stem cells.

Role of OCT4 in cancer stem-like cells and chemotherapy resistance

Cancer stem-like cells (CSCs) contribute to the tumorigenicity, progression, and chemoresistance of cancers. It is not known whether CSCs arise from normal stem cells or if they arise from differentiated cancer cells by acquiring self-renewal features. These CSCs share stem cell markers that normal stem cells express. There is a rising interest in octamer-binding transcription factor 4 (OCT4), one of the stem cell factors that are essential in embryogenesis and pluripotency. OCT4 is also overexpressed in CSCs of various cancers. Although the majority of the studies in CSCs reported a positive association between the expression of OCT4 and chemoresistance and an inverse correlation between OCT4 and clinical prognosis, there are studies rebuking these findings, possibly due to the sparsity of stem cells within tumors and the heterogeneity of tumors. In addition, post-translational modification of OCT4 affects its activity and warrants further investigation for its association with chemoresistance and prognosis.

Circulating Tumour Cells (CTC), Head and Neck Cancer and Radiotherapy; Future Perspectives

Head and neck cancer is the seventh most common cancer in Australia and globally. Despite the current improved treatment modalities, there is still up to 50⁻60% local regional recurrence and or distant metastasis. High-resolution medical imaging technologies such as PET/CT and MRI do not currently detect the early spread of tumour cells, thus limiting the potential for effective minimal residual detection and early diagnosis. Circulating tumour cells (CTCs) are a rare subset of cells that escape from the primary tumour and enter into the bloodstream to form metastatic deposits or even re-establish themselves in the primary site of the cancer. These cells are more aggressive and accumulate gene alterations by somatic mutations that are the same or even greater than the primary tumour because of additional features acquired in the circulation. The potential application of CTC in clinical use is to acquire a liquid biopsy, by taking a reliable minimally invasive venous blood sample, for cell genotyping during radiotherapy treatment to monitor the decline in CTC detectability, and mutational changes in response to radiation resistance and radiation sensitivity. Currently, very little has been published on radiation therapy, CTC, and circulating cancer stem cells (CCSCs). The prognostic value of CTC in cancer management and personalised medicine for head and neck cancer radiotherapy patients requires a deeper understanding at the cellular level, along with other advanced technologies. With this goal, this review summarises the current research of head and neck cancer CTC, CCSC and the molecular targets for personalised radiotherapy response.

Dysregulation of ß-catenin, WISP1 and TCF21 predicts disease-specific survival and primary response against radio(chemo)therapy in patients with locally advanced squamous cell carcinomas of the head and neck

OBJECTIVE

The objective of this study was to determine the prognostic and predictive impact of β-catenin, TCF21 and WISP1 expression in patients with squamous cell carcinomas of the head and neck who underwent primary radiotherapy or concomitant chemoradiotherapy.

STUDY DESIGN

Prospective cohort study.

SETTING

University hospital.

PARTICIPANTS

Protein expression profiles of β-catenin, TCF21, WISP1 and p16 were determined by immunohistochemical analyses in tissue samples of 59 untreated patients. Expression was correlated with different outcome parameters.

MAIN OUTCOME MEASURES

Impact of TNM classification, grading, sex, age, gender, type of therapy, response to therapy and p16 status on disease-specific (DSS) and disease-free survival (DFS).

RESULTS

Patients with high expression of TCF21 were associated with significantly worse disease-specific survival (P = 0.005). In a multivariable analysis, TCF21 was a significant determinant of disease-specific survival. (HR 3.01; P = 0.036). Conversely, low expression of β-catenin (P = 0.025) and WISP1 (P = 0.037) revealed a better response to radiotherapy.

CONCLUSION

Since data show that TCF21 is a prognostic factor for disease-specific survival and WISP1 and ß-catenin are predictive factors for clinical outcome after definitive radiotherapy, further studies are warranted to prove these preliminary but very promising findings.

Molecular pathways of oral cancer that predict prognosis and survival: A systematic review

Several genes and pathways associated with oral squamous cell carcinoma (OSCC) are significant in terms of early detection and prognosis. The objective of this literature review is to evaluate the current research on molecular pathways and genes involved in oral cancer. Articles on the genes involved in oral cancer pathways were evaluated to identify potential biomarkers that can predict survival. In total, 36 articles were retrieved from internet databases, including EBSCO Host, Google Scholar, PubMed, and Science Direct, using the keywords "biomarker of oral cancer," "pathways of oral cancer," "genes involved in oral cancer," and "oral cancer pathways." A total of 36 studies related to OSCC were chosen. Most of the studies used cell lines, while others used archival tissues, few studies followed up the cases. Three major interlinked pathways found were the nuclear factor kappa B (NF-kB), PI3K-AKT, and Wnt pathways. The commonly mutated genes were cyclin D1 (CCND1), Rb, p53, FLJ10540, and TC21. The NF-kB, PI3K-AKT, and Wnt pathways are most frequently involved in the molecular pathogenesis of oral cancer. However, the CCND1, Rb, p53, FLJ10540, and TC21 genes were found to be more accurate in determining patients' overall survival. Polymerase chain reaction, immunohistochemistry, and immunoblotting were the commonly used detection methods.

Cell culture models of oral mucosal barriers: A review with a focus on applications, culture conditions and barrier properties

Understanding the function of oral mucosal epithelial barriers is essential for a plethora of research fields such as tumor biology, inflammation and infection diseases, microbiomics, pharmacology, drug delivery, dental and biomarker research. The barrier properties are comprised by a physical, a transport and a metabolic barrier, and all these barrier components play pivotal roles in the communication between saliva and blood. The sum of all epithelia of the oral cavity and salivary glands is defined as the blood-saliva barrier. The functionality of the barrier is regulated by its microenvironment and often altered during diseases. A huge array of cell culture models have been developed to mimic specific parts of the blood-saliva barrier, but no ultimate standard in vitro models have been established. This review provides a comprehensive overview about developed in vitro models of oral mucosal barriers, their applications, various cultivation protocols and corresponding barrier properties.

Prognostic significance of NANOG expression in solid tumors: a meta-analysis

Purpose

NANOG is a tumor marker and indicates poor prognosis in various neoplasms; however, the evidence is controversial. This meta-analysis investigated the association of NANOG expression and clinicopathological features, and it impact on survival of patients with malignant tumors.

Methods

Studies published through May 31, 2018 were retrieved from PubMed, Web of Science, Embase, and the China National Knowledge Infrastructure. Two researchers independently screened the content and quality of studies and extracted data. Correlations of NANOG expression, clinicopathological variables, and survival were analyzed and the combined odds ratios (ORs) and hazard ratios (HRs) with 95% confidence intervals (95% CIs) were calculated.

Results

Thirty-three articles including 35 data sets of 3,959 patients were analyzed. Overall, elevated NANOG expression was associated with poor overall survival (HR = 2.19; 95% CI: 1.87–2.58, P<0.001) and poor disease-free survival (HR = 2.21, 95% CI: 1.54–3.18, P<0.001). Subgroup analysis found that NANOG expression was associated with worse overall survival in non–small cell lung (HR = 1.87; 95% CI: 1.26–2.76, P = 0.002), head and neck (HR = 2.29; 95% CI: 1.75–3.02, P<0.001), and digestive system (HR = 2.38; 95% CI: 1.95–2.91, P<0.001) cancers. Moreover, we found that high NANOG expression was associated with poor tumor differentiation (OR = 2.63; 95% CI: 1.59–4.55, P = 0.001), lymph node metastasis (OR = 2.59; 95% CI: 1.50–4.47, P = 0.001), advanced TNM stage (OR = 2.22; 95% CI: 1.42–3.45, P<0.001), and T stage (OR = 0.44; 95% CI: 0.20–0.93, P = 0.031).

Conclusion

The evidence supports NANOG as a tumor biomarker to guide clinical management and indicate prognosis. Additional studies are needed to further validate these results.

Prognostic implications of CD44, NANOG, OCT4, and BMI1 expression in tongue squamous cell carcinoma

BACKGROUND

Tongue squamous cell carcinoma (SCC) contains a cell subpopulation referred to as cancer stem cells (CSCs), which are responsible for tumor growth, metastasis, and resistance to chemotherapy and radiotherapy. The CSC markers have been used to isolate these cells and as biomarkers to predict overall survival.

METHODS

The CSC markers CD44, NANOG, OCT4, and BMI1 were investigated using reverse transcriptase-quantitative polymerase chain reaction (RT-qPCR) and immunohistochemistry and correlated with clinicopathological parameters.

RESULTS

The CD44 overexpression was associated with disease-related death (P = 0.02) and worst prognosis. NANOG was upregulated in nontumoral margins and associated with T1/T2 classification, lymph node metastasis, and worst prognosis. OCT4 was associated with lymph node metastasis and worst overall survival. BMI1 and CD44v3 were overexpressed in tongue SCC. Coexpression of CD44⁺⁺ /NANOG⁺⁺ was associated with worst overall survival when compared with patients with CD44^-/+ /NANOG^-/+ .

CONCLUSION

The CSC markers might play an important role not only in CSC trait acquisition but also in tongue SCC development and progression.

Midkine and NANOG Have Similar Immunohistochemical Expression Patterns and Contribute Equally to an Adverse Prognosis of Oral Squamous Cell Carcinoma

To increase the overall survival rate and obtain a better prognosis for oral squamous cell carcinoma (OSCC) patients, the detection of more effective and reliable tumor prognostic markers is needed. This study is focused on the analysis of correlation between the clinicopathological features of OSCCs and the immunohistochemical (IHC) expression patterns of MIDKINE (MK) and NANOG. Sixty-two primary OSCC patients were selected and their pretreatment biopsy specimens were immunohistochemically analyzed for the MK and NANOG proteins. The IHC expression patterns, clinicopathological features, and overall survival rates were assessed to identify any correlations. MK and NANOG showed significantly similar IHC expression patterns: both demonstrated enhanced expression in histologically high-grade and clinically late-stage OSCCs. Weak or negative expression of MK and NANOG was correlated with negative neck node metastasis. Clinicopathologically, late tumor stage, neck node metastasis, high-grade tumor, and palliative treatment groups showed significantly lower overall survival rates. The enhanced expression of MK and NANOG was associated with lower overall survival rates. In particular, enhanced co-detection of MK and NANOG showed significant correlation with poor prognosis. In conclusion, enhanced IHC expression patterns of MK and NANOG in OSCC patients was significantly associated with lower overall survival rates and unfavorable clinicopathological features. These results demonstrate that analysis of IHC expression patterns of MK and NANOG in pretreatment biopsy specimens during the work-up period can provide a more definitive prognosis prediction for each OSCC patient that can help clinicians to develop a more precise individual treatment modality.

Prognostic implication of NOTCH1 in early stage oral squamous cell cancer with occult metastases

OBJECTIVE

The objective of this study was to explore the prognostic value of cancer stem cell markers, namely CD133, NANOG, and NOTCH1, in early stage oral squamous cell carcinoma (OSCC).

MATERIALS AND METHODS

One hundred forty-four patients with early stage (cT1T2N0) OSCC were identified from a pre-existing database of patients with oral cancer. We examined the impact of the immunohistochemical expression of CD133, NANOG, and NOTCH1 in OSCC. Overall survival (OS) curves were calculated using the Kaplan-Meier method. Predictors of outcome were identified using multivariate analysis.

RESULTS

We found that CD133, NANOG, and NOTCH1 were significantly associated with lymph node metastasis, and NOTCH1 was also significantly associated with depth of invasion and locoregional recurrence.

CONCLUSIONS

NOTCH1 was identified as an independent prognostic factor for OS.

CLINICAL RELEVANCE

NOTCH1 might prove to be a useful indicator for high-risk patients with occult metastases from early stage OSCC.

Prognostic Value of Cancer Stem Cell Markers in Head and Neck Squamous Cell Carcinoma: a Meta-analysis

Bmi-1, CD133, Nanog and Oct-4 have been reported as cancer stem cell (CSC) markers in head and neck squamous cell carcinoma (HNSCC). However, the prognostic value of them in HNSCC remains controversial. Hence, this meta-analysis was conducted to access the association between the four CSC markers and survival outcome of HNSCC patients. A total of 22 articles with 27 studies met the inclusion criteria and the combined hazard ratio (HR) and 95% confidence intervals (95% CI) were calculated. Data analysis showed that high expression of CSC markers was associated with poor overall survival (OS) (HR = 1.93; 95% CI: 1.46–2.55, P < 0.001) and disease free survival (DFS) (HR = 4.78; 95% CI: 2.95–7.75, P < 0.001) but not disease specific survival (DSS) (HR = 1.17; 95% CI: 0.74–1.84, P = 0.50) of HNSCC patients. Subgroup analysis indicted that high expression of CD133 (HR = 2.33, 95%CI: 1.42–3.83, P < 0.001), Oct-4(HR = 2.10, 95%CI: 1.36–3.22, P = 0.007) and Nanog (HR = 2.49, 95%CI: 1.66–3.72, P < 0.001) could predict poor OS in HNSCC patients respectively whereas overexpression of Bmi-1 was not related to the reduced OS in HNSCC patients (HR = 1.32, 95%CI: 0.66–2.65, P = 0.43). Therefore, we concluded that CSC markers, especially CD133, Nanog and Oct-4, might be predictive factors in HNSCC patients.

Cell adhesion and urothelial bladder cancer: the role of cadherin switching and related phenomena

Cadherins are mediators of cell-cell adhesion in epithelial tissues. E-cadherin is a known tumour suppressor and plays a central role in suppressing the invasive phenotype of cancer cells. However, the abnormal expression of N- and P-cadherin ('cadherin switching', CS) has been shown to promote a more invasive and m̀alignant phenotype of cancer, with P-cadherin possibly acting as a key mediator of invasion and metastasis in bladder cancer. Cadherins are also implicated in numerous signalling events related to embryonic development, tissue morphogenesis and homeostasis. It is these wide ranging effects and the serious implications of CS that make the cadherin cell adhesion molecules and their related pathways strong candidate targets for the inhibition of cancer progression, including bladder cancer. This review focuses on CS in the context of bladder cancer and in particular the switch to P-cadherin expression, and discusses other related molecules and phenomena, including EpCAM and the development of the cancer stem cell phenotype.

Positive expression of NANOG, mutant p53, and CD44 is directly associated with clinicopathological features and poor prognosis of oral squamous cell carcinoma

Background

In order to predict long-term prognosis and define individual treatment modalities for patients with oral squamous cell carcinoma (OSCC), more reliable tumor biomarkers are needed during the pretreatment workup period. The present study aimed to identify more reliable immunohistochemical tumor prognostic markers in the pretreatment biopsy specimens of patients with OSCC.

Methods

We selected 57 patients who were diagnosed with primary OSCC through histopathological analysis. Pretreatment biopsy specimens were immunohistochemically analyzed for the transcription factor NANOG, cancer stem cell marker CD44, and mutant tumor protein 53 (mutant p53). The immunostaining patterns were assessed for their association with the clinicopathological features of OSCC and overall survival rates.

Results

Late tumor stage, positive neck node metastasis, and high-grade differentiation were associated with significantly poorer survival rates. Enhanced expression of NANOG and mutant p53 positivity were significantly associated with clinically late-stage tumors, positive neck node metastasis, histologically high-grade tumors, and poor overall survival rates. OSCCs with strong co-detection of NANOG and mutant p53 were linked to significantly lower survival rates than those with both weak NANOG expression and p53 negativity. Increased expression of CD44 had a limited correlation with unfavorable clinicopathological features.

Conclusion

High expression of NANOG and positive expression of mutant p53 in the pretreatment biopsy specimens of patients with OSCC were associated with poor survival rates and unfavorable clinicopathological features. These results demonstrate that NANOG, mutant p53, and CD44 could be used as immunohistochemical markers in the pretreatment specimens of OSCC. In particular, analysis for co-expression of NANOG and mutant p53 should be made highly available as a tool for prognosis and selecting individual treatment modalities.

Kallikrein-related peptidase 6 regulates epithelial-to-mesenchymal transition and serves as prognostic biomarker for head and neck squamous cell carcinoma patients

Background

Dysregulated expression of Kallikrein-related peptidase 6 (KLK6) is a common feature for many human malignancies and numerous studies evaluated KLK6 as a promising biomarker for early diagnosis or unfavorable prognosis. However, the expression of KLK6 in carcinomas derived from mucosal epithelia, including head and neck squamous cell carcinoma (HNSCC), and its mode of action has not been addressed so far.

Methods

Stable clones of human mucosal tumor cell lines were generated with shRNA-mediated silencing or ectopic overexpression to characterize the impact of KLK6 on tumor relevant processes in vitro. Tissue microarrays with primary HNSCC samples from a retrospective patient cohort (n = 162) were stained by immunohistochemistry and the correlation between KLK6 staining and survival was addressed by univariate Kaplan-Meier and multivariate Cox proportional hazard model analysis.

Results

KLK6 expression was detected in head and neck tumor cell lines (FaDu, Cal27 and SCC25), but not in HeLa cervix carcinoma cells. Silencing in FaDu cells and ectopic expression in HeLa cells unraveled an inhibitory function of KLK6 on tumor cell proliferation and mobility. FaDu clones with silenced KLK6 expression displayed molecular features resembling epithelial-to-mesenchymal transition, nuclear β-catenin accumulation and higher resistance against irradiation. Low KLK6 protein expression in primary tumors from oropharyngeal and laryngeal SCC patients was significantly correlated with poor progression-free (p = 0.001) and overall survival (p < 0.0005), and served as an independent risk factor for unfavorable clinical outcome.

Conclusions

In summary, detection of low KLK6 expression in primary tumors represents a promising tool to stratify HNSCC patients with high risk for treatment failure. These patients might benefit from restoration of KLK6 expression or pharmacological targeting of signaling pathways implicated in EMT.

Electronic supplementary material

The online version of this article (doi:10.1186/s12943-015-0381-6) contains supplementary material, which is available to authorized users.