SOX2 activation predicts prognosis in patients with head and neck squamous cell carcinoma

Prognostic Value of SOX2 and NANOG Expression in Recurrent Oral Squamous Cell Carcinoma

BACKGROUND

Recurrent oral squamous cell carcinoma (re-OSCC) poses a serious therapeutic challenge and is linked to poor survival outcomes. SOX2 and NANOG, key transcription factors in cancer stem cell biology, may drive tumor progression and therapy resistance. However, their prognostic value in re-OSCC and their relationship to adjuvant therapy remain unclear.

METHODS

We retrospectively analyzed a single-center cohort of 94 patients with re-OSCC treated with curative intent via (1) surgery alone, (2) surgery plus adjuvant radiotherapy (RT), or (3) surgery plus adjuvant radiochemotherapy (RCT). Tissue microarrays (TMAs) were constructed from matched primary and recurrent tumors and immunohistochemical (IHC) staining for SOX2, and NANOG was quantified using H-scores. Post-recurrence overall survival (prOS) and post-recurrence disease-free survival (prDFS) were evaluated using Kaplan-Meier analysis and Cox proportional hazards models.

RESULTS

SOX2 expression and survival: Elevated SOX2 expression (H-score > 14) in re-OSCC was significantly associated with improved prOS (p = 0.013) and prDFS (p = 0.026). Notably, patients who had received adjuvant therapy (particularly RCT) showed higher SOX2 levels in recurrent tumors compared to those treated with surgery alone. NANOG expression and therapy: NANOG expression declined markedly from primary to recurrent tumors (median H-score 42.2 vs. 8.7; p < 0.001). This decline was most pronounced in patients treated with surgery alone. Despite this dynamic change, NANOG expression did not correlate significantly with prOS or prDFS. Other prognostic factors include advanced tumor stage (rT2-rT4) and lymph node involvement (rN+/x)m which remained significant predictors of worse survival in the recurrent setting, regardless of adjuvant therapy.

CONCLUSION

SOX2 overexpression in re-OSCC correlates with better survival, suggesting a unique prognostic role distinct from primary disease. Adjuvant therapy, especially RCT, appears to maintain or elevate SOX2 levels, potentially contributing to improved treatment response. In contrast, although NANOG expression decreases in recurrence, particularly in patients who undergo surgery alone, it does not significantly affect survival outcomes. These findings underscore the importance of context-specific biomarker assessments and provide a rationale for incorporating SOX2 status into personalized treatment strategies for re-OSCC.

Expression analysis of SOX2 and SOX9 in patients with oral squamous cell carcinoma

BACKGROUND

Lately SOX2 and SOX9, transcription factors associated with stemness-like phenotypes of cancer cells, have been linked to tumor growth, metastasis, and resistance to therapy.

METHODS

This study aimed on evaluating the expression of SOX2 and SOX9 in a large cohort of patients with OSCC including primary and recurrent tumors and corresponding lymph node metastases. Semiautomatic digital pathology scoring was used to determine protein expression and survival analysis was performed to evaluate its prognostic significance.

RESULTS

We found a significant downregulation of SOX9 from primary disease to lymph node metastases (p < 0.001). SOX9 expression and the subgroup SOX2lowSOX9high were significantly correlated with worse overall survival (p < 0.05). Additionally, SOX2lowSOX9high expression pattern was confirmed as independent prognosticator for overall survival.

CONCLUSIONS

These results indicate the relevant role of SOX2 and SOX9 in patients with OSCC and show the clinical relevance for further investigation on the molecular mechanisms underlying SOX-related gene expression.

The Role of SOX2 and SOX9 in Radioresistance and Tumor Recurrence

Head and neck squamous cell carcinoma (HNSCC) exhibits considerable variability in patient outcome. It has been reported that SOX2 plays a role in proliferation, tumor growth, drug resistance, and metastasis in a variety of cancer types. Additionally, SOX9 has been implicated in immune tolerance and treatment failures. SOX2 and SOX9 induce treatment failure by a molecular mechanism that has not yet been elucidated. This study explores the inverse association of SOX2/SOX9 and their distinct expression in tumors, influencing the tumor microenvironment and radiotherapy responses. Through public RNA sequencing data, human biopsy samples, and knockdown cellular models, we explored the effects of inverted SOX2 and SOX9 expression. We found that patients expressing SOX2LowSOX9High showed decreased survival compared to SOX2HighSOX9Low. A survival analysis of patients stratified by radiotherapy and human papillomavirus brings additional clinical relevance. We identified a gene set signature comprising newly discovered candidate genes resulting from inverted SOX2/SOX9 expression. Moreover, the TGF-β pathway emerges as a significant predicted contributor to the overexpression of these candidate genes. In vitro findings reveal that silencing SOX2 enhances tumor radioresistance, while SOX9 silencing enhances radiosensitivity. These discoveries lay the groundwork for further studies on the therapeutic potential of transcription factors in optimizing HNSCC treatment.

Prognostic biomarkers for the response to the radiosensitizer nimorazole combined with RCTx: a pre-clinical trial in HNSCC xenografts

BACKGROUND

Tumor hypoxia is associated with resistance to radiotherapy and chemotherapy. In head and neck squamous cell carcinoma (HNSCC), nimorazole, an oxygen mimic, combined with radiotherapy (RT) enabled to improve loco-regional control (LRC) in some patients with hypoxic tumors but it is unknown whether this holds also for radiochemotherapy (RCTx). Here, we investigated the impact of nimorazole combined with RCTx in HNSCC xenografts and explored molecular biomarkers for its targeted use.

METHODS

Irradiations were performed with 30 fractions in 6 weeks combined with weekly cisplatin. Nimorazole was applied before each fraction, beginning with the first or after ten fractions. Effect of RCTx with or without addition of nimorazole was quantified as permanent local control after irradiation. For histological evaluation and targeted gene expression analysis, tumors were excised untreated or after ten fractions. Using quantitative image analysis, micromilieu parameters were determined.

RESULTS

Nimorazole combined with RCTx significantly improved permanent local control in two tumor models, and showed a potential improvement in two additional models. In these four models, pimonidazole hypoxic volume (pHV) was significantly reduced after ten fractions of RCTx alone. Our results suggest that nimorazole combined with RCTx might improve TCR compared to RCTx alone if hypoxia is decreased during the course of RCTx but further experiments are warranted to verify this association. Differential gene expression analysis revealed 12 genes as potential for RCTx response. When evaluated in patients with HNSCC who were treated with primary RCTx, these genes were predictive for LRC.

CONCLUSIONS

Nimorazole combined with RCTx improved local tumor control in some but not in all HNSCC xenografts. We identified prognostic biomarkers with the potential for translation to patients with HNSCC.

The Role of Hedgehog Signaling Pathway in Head and Neck Squamous Cell Carcinoma

Head and neck squamous cell carcinoma (HNSCC) is the sixth leading malignancy worldwide, with a poor prognosis and limited treatment options. Molecularly targeted therapies for HNSCC are still lacking. However, recent reports provide novel insights about many molecular alterations in HNSCC that may be useful in future therapies. Therefore, it is necessary to identify new biomarkers that may provide a better prediction of the disease and promising targets for personalized therapy. The poor response of HNSCC to therapy is attributed to a small population of tumor cells called cancer stem cells (CSCs). Growing evidence indicates that the Hedgehog (HH) signaling pathway plays a crucial role in the development and maintenance of head and neck tissues. The HH pathway is normally involved in embryogenesis, stem cell renewal, and tissue regeneration. However, abnormal activation of the HH pathway is also associated with carcinogenesis and CSC regulation. Overactivation of the HH pathway was observed in several tumors, including basal cell carcinoma, that are successfully treated with HH inhibitors. However, clinical studies about HH pathways in HNSCC are still rare. In this review, we summarize the current knowledge and recent advances regarding the HH pathway in HNSCC and discuss its possible implications for prognosis and future therapy.

FOXM1: A small fox that makes more tracks for cancer progression and metastasis

Transcription factors (TFs) are indispensable for the modulation of various signaling pathways associated with normal cell homeostasis and disease conditions. Among cancer-related TFs, FOXM1 is a critical molecule that regulates multiple aspects of cancer cells, including growth, metastasis, recurrence, and stem cell features. FOXM1 also impact the outcomes of targeted therapies, chemotherapies, and immune checkpoint inhibitors (ICIs) in various cancer types. Recent advances in cancer research strengthen the cancer-specific role of FOXM1, providing a rationale to target FOXM1 for developing targeted therapies. This review compiles the recent studies describing the pivotal role of FOXM1 in promoting metastasis of various cancer types. It also implicates the contribution of FOXM1 in the modulation of chemotherapeutic resistance, antitumor immune response/immunotherapies, and the potential of small molecule inhibitors of FOXM1.

GSK3β-driven SOX2 overexpression is a targetable vulnerability in esophageal squamous cell carcinoma

Esophageal squamous cell carcinoma (ESCC) is one of the deadliest forms of human malignancy that currently lacks approved targeted therapeutics. Accumulating evidence suggests that SOX2 overexpression is a key driving factor for ESCC and various squamous cell carcinoma. Here, through screening a small-molecule kinase inhibitor library, we identified GSK3β as a kinase that is critically required for robust SOX2 expression in ESCC cells. GSK3β did not promote SOX2 transcriptionally but was required for SOX2 protein stability. We demonstrated that GSK3β interacts with and phosphorylates SOX2 at residue S251, which blocks SOX2 from ubiquitination and proteasome-dependent degradation instigated by ubiquitin E3 ligase CUL4ADET1-COP1. Pharmacological inhibition or knockdown of GSK3β by RNA interference selectively impaired SOX2-positive ESCC cell proliferation, cancer stemness, and tumor growth in mouse xenograft model, suggesting that GSK3β promotes ESCC tumorigenesis primarily by driving SOX2 overexpression. GSK3β was found to be frequently overexpressed in clinical esophageal tumors, and there was a positive correlation between GSK3β and SOX2 protein levels. Notably, we found that SOX2 enhanced GSK3β expression transcriptionally, suggesting the existence of a vicious cycle that drives a coordinated GSK3β and SOX2 overexpression in ESCC cells. Finally, we demonstrated in tumor xenograft model that GSK3β inhibitor AR-A014418 was effective in suppressing SOX2-positive ESCC tumor progression and inhibited tumor progression cooperatively with chemotherapeutic agent carboplatin. In conclusion, we uncovered a novel role for GSK3β in driving SOX2 overexpression and tumorigenesis and provided evidence that targeting GSK3β may hold promise for the treatment of recalcitrant ESCCs.

Human papillomavirus integration transforms chromatin to drive oncogenesis

BACKGROUND

Human papillomavirus (HPV) drives almost all cervical cancers and up to 70% of head and neck cancers. Frequent integration into the host genome occurs predominantly in tumorigenic types of HPV. We hypothesize that changes in chromatin state at the location of integration can result in changes in gene expression that contribute to the tumorigenicity of HPV.

RESULTS

We find that viral integration events often occur along with changes in chromatin state and expression of genes near the integration site. We investigate whether introduction of new transcription factor binding sites due to HPV integration could invoke these changes. Some regions within the HPV genome, particularly the position of a conserved CTCF binding site, show enriched chromatin accessibility signal. ChIP-seq reveals that the conserved CTCF binding site within the HPV genome binds CTCF in 4 HPV^+ cancer cell lines. Significant changes in CTCF binding pattern and increases in chromatin accessibility occur exclusively within 100 kbp of HPV integration sites. The chromatin changes co-occur with out-sized changes in transcription and alternative splicing of local genes. Analysis of The Cancer Genome Atlas (TCGA) HPV⁺ tumors indicates that HPV integration upregulates genes which have significantly higher essentiality scores compared to randomly selected upregulated genes from the same tumors.

CONCLUSIONS

Our results suggest that introduction of a new CTCF binding site due to HPV integration reorganizes chromatin state and upregulates genes essential for tumor viability in some HPV⁺ tumors. These findings emphasize a newly recognized role of HPV integration in oncogenesis.

The Immune Response Generated against HPV Infection in Men and Its Implications in the Diagnosis of Cancer

Human papillomavirus (HPV) infection is associated with precancerous lesions and cancer of the genital tract both in women and men. The high incidence of cervical cancer worldwide focused the research on this infection mainly in women and to a lesser extent in men. In this review, we summarized epidemiological, immunological, and diagnostic data associated with HPV and cancer in men. We presented an overview of the main characteristics of HPV and infection in men that are associated with different types of cancer but also associated with male infertility. Men are considered important vectors of HPV transmission to women; therefore, identifying the sexual and social behavioral risk factors associated with HPV infection in men is critical to understand the etiology of the disease. It is also essential to describe how the immune response develops in men during HPV infection or when vaccinated, since this knowledge could help to control the viral transmission to women, decreasing the incidence of cervical cancer, but also could reduce other HPV-associated cancers among men who have sex with men (MSM). Finally, we summarized the methods used over time to detect and genotype HPV genomes, as well as some diagnostic tests that use cellular and viral biomarkers that were identified in HPV-related cancers.

SOX2-associated signaling pathways regulate biological phenotypes of cancers

SOX2 is a transcription factor involved in multiple stages of embryonic development. In related reports, SOX2 was found to be abnormally expressed in tumor tissues and correlated with clinical features such as TNM staging, tumor grade, and prognosis in patients with various cancer types. In most cancer types, SOX2 is a tumor-promoting factor that regulates tumor progression and metastasis primarily by maintaining the stemness of cancer cells. In addition, SOX2 also regulates the proliferation, apoptosis, invasion, migration, ferroptosis and drug resistance of cancer cells. However, SOX2 acts as a tumor suppressor in some cases in certain cancer types, such as gastric and lung cancer. These key regulatory functions of SOX2 involve complex regulatory networks, including protein-protein and protein-nucleic acid interactions through signaling pathways and noncoding RNA interactions, modulating SOX2 expression may be a potential therapeutic strategy for clinical cancer patients. Therefore, we sorted out the phenotypes related to SOX2 in cancer, hoping to provide a basis for further clinical translation.

CXCR3 isoform A promotes head and neck cancer progression by enhancing stem-like property and chemoresistance

The chemokine network orchestrates the cancer stem-like property and consequently participates in cancer progression. CXCR3 contributes cancer progressive property and immunomodulation in the tumor microenvironment. The two major isoforms of CXCR3 are scrutinized and the divergence is showed that CXCR3A promotes cancer cell growth and motility while CXCR3B functions contrarily in many studies. However, rare studies illustrate the role of CXCR3 isoforms in cancer stem-like property and chemoresistance, especially in head and neck cancer (HNC). First, we used immunohistochemistry staining to evaluate expression levels of CXCR3, CXCR3B, and Sox2 cancer stem cell (CSC) marker and association with tumor progression in HNC tissues. Results showed that high levels of CXCR3 were significantly associated with advanced stage (p <0.01), regional lymph node metastasis (p <0.05), and poor differentiation (p <0.005) and further correlated with worse survival rate in oral cancer patients (p = 0.036). Higher levels of CXCR3B were found in regional lymphatic invasion of HNC and progressive stage of squamous cell carcinoma. Elevated Sox2 expression was significantly associated with the advanced stage of HNC in the oral cavity, and demonstrated a co-expression pattern with CXCR3B. Furthermore, lentivirus-mediated overexpression of CXCR3A and CXCR3B in SAS human oral cancer cells promoted cell mobility. CXCR3A overexpression enhanced sphere-forming ability and chemoresistance of CSCs by upregulating stemness-related genes. This study first provides a novel insight of CXCR3 isoform A in HNC cancer progression via regulating cancer stem-like properties and chemoresistance, suggesting that CXCR3A may be a prognostic marker and novel target for HNC therapy.

Prognostic and predictive roles of cancer stem cell markers in head and neck squamous cell carcinoma patients receiving chemoradiotherapy with or without nimotuzumab

BACKGROUND

Anti-EGFR-based therapies have limited success in HNSCC patients. Predictive biomarkers are needed to identify the patients most likely to benefit from these therapies. Here, we present predictive and prognostic associations of different cancer stem cell markers in HPV-negative locally advanced (LA) HNSCC patients.

METHODS

Pretreatment tumour tissues of 404 HPV-negative LA-HNSCCs patients, a subset of-phase 3-randomised study comparing cisplatin-radiation(CRT) and nimotuzumab plus cisplatin-radiation(NCRT) were examined. The expression levels of CD44, CD44v6, CD98hc, ALDH1A1, SOX2 and OCT4A were evaluated using immunohistochemistry. Progression-free survival(PFS), loco-regional control(LRC),- and overall survival(OS) were estimated by Kaplan-Meier method. Hazard ratios were estimated by Cox proportional hazard models.

RESULTS

NCRT showed significantly improved OS with low membrane expression of CD44 compared to CRT [HR (95% CI) = 0.63 (0.46-0.88)]. Patients with low CD44v6 also showed better outcomes with NCRT [LRC: HR (95% CI) = 0.25 (0.10-0.62); OS: HR (95% CI) = 0.38 (0.19-0.74)]. No similar benefit with NCRT observed in patients with high CD44 or CD44v6 expression. Bootstrap resampling confirmed the predictive effect of CD44 (Interaction P = 0.015) and CD44v6 (Interaction P = 0.041) for OS. Multivariable Cox analysis revealed an independent negative prognostic role of CD98hc membrane expression for LRC [HR (95% CI) = 0.63(0.39-1.0)] and OS[HR (95% CI) = 0.62 (0.40-0.95)].

CONCLUSIONS

CD44 and CD44v6 are potential predictive biomarkers for NCRT response. CD98hc emerged as an independent negative prognostic biomarker.

CLINICAL TRIAL REGISTRATION

Registered with the Clinical Trial Registry of India (Trial registration identifier-CTRI/2014/09/004980).

Lack of CD44 and Sox-2 Overexpression as Two Independent Favourable Prognostic Factors in HPV Positive Patients with Oropharyngeal Cancers

INTRODUCTION

In our earlier publications, in the group of 63 patients with oropharyngeal cancer, we have found HPV16 infection (assessed by qPCR) in 25 tumours (39.7%), immunohistochemical overexpression of CD44, CD98, ALDH1/2 and Nanog in, respectively: 43 (68.2%), 30 (47.6%), 33 (52.4%), and 53 (84.1%) cancers. Analysing CD44, CD98, ALDH1/2, we have also shown that lack of CD44 overexpression indicates excellent prognosis in patients with HPV16 positivity. The aim of the present study was to compare prognostic potential of Nanog, Oct3/4, Sox-2 expression in relation to CD44, CD98, ALDH1/2 immunoreactivity (assessed by us earlier) and clinicopathological features in the subgroups of patients: with HPV16 positivity and HPV16 negativity.

METHODS

Status of Oct3/4 and Sox-2 expression was assessed for 63 patients with oropharyngeal cancers based on immunohistochemistry. In survival analysis, two endpoints were applied: overall survival (OS) and disease-free survival (DFS).

RESULTS

Overexpression of Oct3/4 and Sox-2 was found in 0 (0.0%) and 27 (42.9%) of patients. In the subgroup with HPV16 positivity, the DFS for patients with lack of Sox-2 overexpression was significantly (p = 0.003) higher than for patients with Sox-2 overexpression. In the subgroup with HPV16 negativity, Nanog and Sox-2 immunoexpression did not significantly influence OS and DFS. In multivariate analysis performed for the subgroup with HPV16 positivity, lack of CD44 overexpression (p = 0.012) and lack of Sox-2 overexpression (p = 0.027) were positive independent prognostic factors.

CONCLUSION

Based on CD44 and Sox-2 immunoreactivity, it is possible to differentiate the prognosis of HPV16-positive patients with oropharyngeal cancers.

Clinical Significance and Prognostic Value of SOX2 Protein Expression in Patients With Oral Squamous Cell Carcinoma

OBJECTIVES

Cancer stem cells are a small group of highly tumorigenic cells with the trend of self-renewal, tumor progression, metastasis, recurrence, and therapeutic resistance. SOX2 is an important cancer stem cell marker that is involved in tumorigenesis and correlated with aggressive features in various types of malignancies. The present study was aimed to investigate the expression of this biomarker in neoplastic tissues of oral squamous cell carcinoma (OSCC) to determine whether it has the potential to predict the outcomes and survival of the affected patients.

MATERIALS AND METHODS

The medical records of 73 patients diagnosed with OSCC were retrospectively studied. Clinical and pathologic features included age, sex, tumor size, histologic grade, lymph node involvement, recurrence, metastasis, and follow up. Immunohistochemical analysis for SOX2 protein expression was performed, and its correlations with clinicopathologic features were evaluated.

RESULTS

SOX2 was significantly associated with tumor size, lymph node metastasis, and patients' survival. We found no apparent correlation between SOX2 and tumor recurrence, distant metastasis, or differentiation. The multivariate analysis identifies patients' age, sex, and SOX2 expression as independent prognostic factors for overall survival.

CONCLUSION

SOX2 may worsen the prognosis and be a progressive malignant factor, which can help clinicians investigate OSCC patients' survival and plan the appropriate treatment accordingly.

SOX2 and Bcl-2 as a Novel Prognostic Value in Hepatocellular Carcinoma Progression

Sex-determining region Y-box 2 (SOX2) is a stem cell transcription factor and a major regulator of self-renewal and pluripotency of cancer stem cells (CSCs). In many types of cancer, SOX2 is dysregulated due to overexpression associated with tumor progression and low survival rate. Many HCC cases encounter recurrence and metastasis which might be due to CSCs and also apoptosis. Since little is known about the expression pattern of SOX2 and apoptotic genes in HCC, we aimed to determine the prognostic significance of SOX2, Bax, and Bcl-2 in clinicopathological features, tumor progression, and survival rate of the HCC patients. The expression of SOX2, Bax, and Bcl-2 were evaluated using qRT-PCR in 53 formalin-fixed, paraffin-embedded tissues (FFPE) of patients and 44 controls. Correlation of these genes was analyzed with clinicopathological features and tumor progression. The correlationship between SOX2 expression and ALBI grade as prognostic indicators were calculated. Survival rates were determined by Kaplan–Meier survival curves. SOX2 and Bcl-2 were remarkably overexpressed in HCC patients compared to controls (p = 0.04 and p = 0.003, respectively). A significant association was found for both SOX2 and Bcl-2 overexpression with TNM staging (p = 0.02, p = 0.04) and tumor grading (p = 0.01, p = 0.003), respectively. A significant correlation was observed: patients with SOX2 overexpression had a lower 5-year overall survival rate (p = 0.04); however, there was no significant association between Bcl-2 and survival (p = 0.5). Collectively, overexpression of SOX2 and Bcl-2, alone or combined, may be a potential marker to evaluate prognosis and response to HCC treatment.

Cancer Stem Cells in Oropharyngeal Cancer

Oropharyngeal cancer (OPC), which is a common type of head and neck squamous cell carcinoma (HNSCC), is associated with tobacco and alcohol use, and human papillomavirus (HPV) infection. Underlying mechanisms and as a result prognosis of the HPV-positive and HPV-negative OPC patients are different. Like stem cells, the ability of self-renewal and differentiate, cancer stem cells (CSCs) have roles in tumor invasion, metastasis, drug resistance, and recurrence after therapy. Research revealed their roles to some extent in all of these processes but there are still many unresolved points to connect to CSC-targeted therapy. In this review, we will focus on what we currently know about CSCs of OPC and limitations of our current knowledge. We will present perspectives that will broaden our understanding and recent literature which may connect to therapy.

Establishment of a Plasticity-Associated Risk Model Based on a SOX2- and SOX9-Related Gene Set in Head and Neck Squamous Cell Carcinoma

Recent studies highlighted SOX2 and SOX9 as key determinants for cancer-cell plasticity and demonstrated that cisplatin-induced adaptation in oral squamous cell carcinoma (SCC) is acquired by an inverse regulation of both transcription factors. However, the association between SOX2/SOX9-related genetic programs with risk factors and genetic or epigenetic alterations in primary head and neck SCC (HNSCC), and their prognostic value is largely unknown.Here, we identified differentially-expressed genes (DEG) related to SOX2 and SOX9 transcription in The Cancer Genome Atlas (TCGA)-HNSC, which enable clustering of patients into groups with distinct clinical features and survival. A prognostic risk model was established by LASSO Cox regression based on expression patterns of DEGs in TCGA-HNSC (training cohort), and was confirmed in independent HNSCC validation cohorts as well as other cancer cohorts from TCGA. Differences in the mutational landscape among risk groups of TCGA-HNSC demonstrated an enrichment of truncating NSD1 mutations for the low-risk group and elucidated DNA methylation as modulator of SOX2 expression. Gene set variation analysis (GSVA) revealed differences in several oncogenic pathways among risk groups, including upregulation of gene sets related to oncogenic KRAS signaling for the high-risk group. Finally, in silico drug screen analysis revealed numerous compounds targeting EGFR signaling with significantly lower efficacy for cancer cell lines with a higher risk phenotype, but also indicated potential vulnerabilities. IMPLICATIONS: The established risk model identifies patients with primary HNSCC, but also other cancers at a higher risk for treatment failure, who might benefit from a therapy targeting SOX2/SOX9-related gene regulatory and signaling networks.

Heparanase 2 (Hpa2) attenuates tumor growth by inducing Sox2 expression

The pro-tumorigenic properties of heparanase are well documented, and heparanase inhibitors are being evaluated clinically as anti-cancer therapeutics. In contrast, the role of heparanase 2 (Hpa2), a close homolog of heparanase, in cancer is largely unknown. Previously, we have reported that in head and neck cancer, high levels of Hpa2 are associated with prolonged patient survival and decreased tumor cell dissemination to regional lymph nodes, suggesting that Hpa2 functions to restrain tumorigenesis. Also, patients with high levels of Hpa2 were diagnosed as low grade and exhibited increased expression of cytokeratins, an indication that Hpa2 promotes or maintains epithelial cell differentiation and identity. To reveal the molecular mechanism underlying the tumor suppressor properties of Hpa2, and its ability to induce the expression of cytokeratin, we employed overexpression as well as gene editing (Crispr) approaches, combined with gene array and RNAseq methodologies. At the top of the list of many genes found to be affected by Hpa2 was Sox2. Here we provide evidence that silencing of Sox2 resulted in bigger tumors endowed with reduced cytokeratin levels, whereas smaller tumors were developed by cells overexpressing Sox2, suggesting that in head and neck carcinoma, Sox2 functions to inhibit tumor growth. Notably, Hpa2-null cells engineered by Crispr/Cas 9, produced bigger tumors vs control cells, and rescue of Hpa2 attenuated tumor growth. These results strongly imply that Hpa2 functions as a tumor suppressor in head and neck cancer, involving Sox2 upregulation mediated, in part, by the high-affinity interaction of Hpa2 with heparan sulfate.

STINGing Viral Tumors: What We Know from Head and Neck Cancers

It has now become increasingly clear that viruses, which may not be directly oncogenic, can affect the biology of tumors as well as immune behavior against tumors. This has led to a fundamental question: Should tumors associated with viral infection be considered distinct from those without? Typically, viruses activate the host innate immune responses by stimulating pathogen recognition receptors and DNA-sensing pathways, including the stimulator of interferon genes (STING) pathway. However, regulation of the STING pathway in a virus-associated tumor microenvironment is poorly understood. Human papillomavirus (HPV) infection within a subset of head and neck squamous cell carcinomas (HNSCC) promotes a unique etiology and clinical outcome. For reasons currently not well understood, patients with HPV⁺ tumors have a better outcome in terms of both overall survival and reduced risk of recurrence compared with HPV^- HNSCC. This observation may reflect a greater intrinsic immunogenicity associated with HPV infection, pertaining to innate immune system pathways activated following recognition of viral nucleotides. Here we discuss how HNSCC provides a unique model to study the STING pathway in the context of viral-induced tumor type as well as recent advances in our understanding of this pathway in HSNCC.

SOX2 amplification and chromosome 3 gain significantly impact prognosis in esophageal squamous cell carcinoma

Background

We aimed to investigate the prevalence and prognostic role of Sex determining region Y-box 2 (SOX2) amplification and expression in surgically resected esophageal squamous cell carcinoma (ESCC).

Methods

We evaluated 450 ESCC samples using fluorescence in-situ hybridization and immunohistochemistry for SOX2 gene amplification and protein expression, respectively. The relationships of gene status with various clinicopathological characteristics and patient survival were statistically analyzed.

Results

SOX2 amplifications and chromosome 3 gain were observed in 4.4% and 12.9% of patients with ESCC. SOX2 amplification was associated with later clinical stage, and chromosome 3 gain was associated with earlier clinical stage (P=0.025). Low and high SOX2 expression were found in 28.9% and 24.7% of cases, respectively. SOX2 expression was significantly associated with gene copy number variation (P=0.007). SOX2 amplification was associated with a significantly shorter disease-free survival (DFS) or overall survival (OS). However, chromosome 3 gain was associated with a significantly longer DFS or OS (P<0.001). Multivariate analysis using the Cox proportional hazard model indicated that SOX2 amplification was an independently poorer prognostic factor (DFS, P<0.001, HR 2.638, 95% CI, 1.581–4.403; OS, P<0.001, HR 2.608, 95% CI, 1.562–4.355), along with pathology tumor-node-metastasis (pTNM) stage, whereas chromosome 3 gain was an independently better prognostic factor (DFS, P=0.003, HR 0.486, 95% CI, 0.300–0.789; OS, P=0.003, HR 0.474, 95% CI, 0.289–0.779) for ESCC.

Conclusions

This is the first study wherein SOX2 amplification and chromosome 3 gain in a large cohort of ESCC were evaluated. SOX2 amplification is an independently poorer prognostic factor, whereas chromosome 3 gain is an independently favorable prognostic factor. Our results suggest that SOX2 amplification and chromosome 3 gain are potential biomarkers related to tumor progression and risk stratification in ESCC.

Two novel cell culture models of buccal mucosal oral cancer from patients with no risk-habits of tobacco smoking or chewing

OBJECTIVE

Tobacco consumption is one of the major etiological factors for oral cancer, but it also develops in non-tobacco users, with unknown etiologies. Cellular models for tobacco associated oral cancer are available, however; reports of cellular models for studying non-tobacco associated oral cancer are limiting. We report here the establishment and characterization of two novel buccal mucosal cancer cell lines 'GBC02' and 'GBC035' derived from non-tobacco users.

MATERIALS AND METHODS

Short tandem repeats (STR) profiling, Next-generation sequencing for whole-genome, exome and copy number alterations, immunofluorescence, flow-cytometry, proliferation, live-cell chemotaxis, 3D-spheroid formation, chemotherapy response, gene-expression microarray, gene-set enrichment analysis and xenograft development were performed.

RESULTS

Sources of the established cultures were matched to their donors through STR profiling. Genome sequence analysis revealed somatic mutations in TP53, CASP8, CDKN2A for GBC02 with deletions and amplifications encompassing CDKN2A, FAT1 and CCND1, PIK3CA, SOX2, EGFR, MYC genes, respectively. GBC035 harbored mutations in FAT1, NOTCH1, HRAS, CDKN2A, HLA-B, HLA-A genes. While GBC035 cells showed higher E-Cadherin positive cell-cell junctions and collective cell migration in chemotaxis; GBC02 cells were vimentin-positive and demonstrated individual cell migration. Further, exhibiting their relevance to preclinical research, GBC02 3D-spheroids demonstrated enrichment of development-related gene-signatures in microarray transcriptome analysis and were resistant to Cisplatin, but showed sensitivity to cancer stem cells-targeting drug, Salinomycin. Additionally, tumorigenic ability of GBC02 was demonstrated.

CONCLUSIONS

Altogether, we present here comprehensively characterized unique cell lines established from non-tobacco associated tumors, which may serve as models for preclinical investigations of oral cancers caused independent of tobacco usage.

SOX2 and squamous cancers

SOX2 is a pleiotropic nuclear transcription factor with major roles in stem cell biology and in development. Over the last 10 years SOX2 has also been implicated as a lineage-specific oncogene, notably in squamous carcinomas but also neurological tumours, particularly glioblastoma. Squamous carcinomas (SQCs) comprise a common group of malignancies for which there are no targeted therapeutic interventions. In this article we review the molecular epidemiological and laboratory evidence linking SOX2 with squamous carcinogenesis, explore in detail the multifaceted impact of SOX2 in SQC, describe areas of uncertainty and highlight areas for potential future research.

Effects of Maackia amurensis seed lectin (MASL) on oral squamous cell carcinoma (OSCC) gene expression and transcriptional signaling pathways

PURPOSE

Oral cancer causes over 120,000 deaths annually and affects the quality of life for survivors. Over 90% of oral cancers are derived from oral squamous cell carcinoma cells (OSCCs) which are generally resistant to standard cytotoxic chemotherapy agents. OSCC cells often exhibit increased TGFβ and PDPN receptor activity compared to nontransformed oral epithelial cells. Maackia amurensis seed lectin (MASL) can target the PDPN receptor and has been identified as a novel agent that can be used to treat oral cancer. However, mechanisms by which MASL inhibits OSCC progression are not yet clearly defined.

METHODS

Here, we performed cell migration and cytotoxicity assays to assess the effects of MASL on OSCC motility and viability at physiologically relevant concentrations. We then performed comprehensive transcriptome analysis combined with transcription factor reporter assays to investigate the how MASL affects OSCC gene expression at these concentration. Key data were then confirmed by western blotting to evaluate the effects of MASL on gene expression and kinase signaling activity at the protein level.

RESULTS

MASL significantly affected the expression of about 27% of approximately 15,000 genes found to be expressed by HSC-2 cells used to model OSCC cells in this study. These genes affected by MASL include members of the TGFβ-SMAD, JAK-STAT, and Wnt-βCTN signaling pathways. In particular, MASL decreased expression of PDPN, SOX2, and SMAD5 at the RNA and protein levels. MASL also inhibited SMAD and MAPK activity, and exhibited potential for combination therapy with doxorubicin and 5-fluorouracil.

CONCLUSIONS

Taken together, results from this study indicate that MASL decreases activity of JAK-STAT, TGFβ-SMAD, and Wnt-βCTN signaling pathways to inhibit OSCC growth and motility. These data suggest that further studies should be undertaken to determine how MASL may also be used alone and in combination with other agents to treat oral cancer.

Prognostic Implication of SOX2 Expression Associated with p16 in Oropharyngeal Cancer: A Study of Consecutive Tissue Microarrays and TCGA

Simple Summary

The role of human papillomavirus (HPV) in oropharyngeal cancer (OPSCC) as a cause agent has been reported in much of the literature. As a surrogate marker, p16 immunohistochemical staining is used as the standard for classifying OPSCC, and the prognosis of p16+ OPSCC has been reported to be better than p16− OPSCC. However, it was necessary to study what is the next biomarker that could predict the prognosis after classification by p16. We assumed that SOX2 may be a potential biomarker. For each p16+ and p16− OPSCC, SOX2 was used to analyze whether the degree of expression level differed in survival and recurrence rates. The results showed that both immunohistochemical staining and mRNA expression level of SOX2 significantly affected the survival and recurrence rates of p16+ OPSCC patients in two different datasets which were constructed in differently ways. Our study presented the clinical applicability of SOX2 as a biomarker.

Abstract

For oropharyngeal squamous cell carcinoma (OPSCC), there are not enough additional robust biomarkers for subgrouping after the distinct classification using p16. As SOX2 is an emerging biomarker for cancer treatment, its clinical implication in OPSCC was evaluated using a consecutive tissue microarray (TMA) cohort consisting of 111 patients who underwent surgery as an initial treatment from May 2002 to December 2016 and 79 patients in The Cancer Genome Atlas (TCGA) dataset. In both datasets, p16+/SOX2^High (HPV+/SOX2^High in TCGA) showed the best prognosis among the four groups classified by SOX2 and p16 for 5-year overall survival (OS) and recurrence (all p < 0.05), but SOX2 did not make a significant difference in the prognosis of the p16− group. In the TMA cohort, SOX2^High was significantly correlated with response to radiotherapy and lower pathologic T classification in the p16+ group (p = 0.001). In TCGA, correlations between SOX2 and tumor stage classification or radiotherapy were not observed; however, HPV+/SOX2^High had a significantly low tumor mutation burden among the four groups (all p < 0.05). In summary, SOX2 was proven to be a potential marker to predict overall survival and recurrence in p16+ OPSCC. However, the role of SOX2 has not yet been confirmed in p16− OPSCC patients.

Review of emerging biomarkers in head and neck squamous cell carcinoma in the era of immunotherapy and targeted therapy

BACKGROUND

Biomarkers in head and neck squamous cell carcinoma (HNSCC) emerge rapidly in recent years, especially for new targeted therapies and immunotherapies.

METHODS

Recent, relevant peer-reviewed evidence were critically reviewed and summarized.

RESULTS

This review article briefly introduces essential biomarker concepts, including purposes and classifications (predictive, prognostic, and diagnostic markers), and the phases of biomarker development. We summarize current biomarkers in order of clinical utility; p16 and human papillomavirus status remain the most important and validated biomarkers in HNSCC. The rationale for biomarker study design continues to evolve with technological advances, especially whole-exome or whole-genomic sequencing. Noninvasive body fluid and liquid biopsy biomarkers appear to hold strong potential for development as tools for early cancer detection, cancer diagnosis, monitoring of disease recurrence, and outcome prediction. In light of discrepancies among different technologies, standardized approaches are needed.

CONCLUSION

Biomarkers from cancer tissue or blood in HNSCC could direct new anticancer therapies.

Prognostic Significance of the Pluripotency Factors NANOG, SOX2, and OCT4 in Head and Neck Squamous Cell Carcinomas

Cancer stem cells (CSCs) play major roles in tumor initiation, progression, and resistance to cancer therapy. Several CSC markers have been studied in head and neck squamous cell carcinomas (HNSCC), including the pluripotency factors NANOG, SOX2, and OCT4; however, their clinical significance is still unclear. NANOG, SOX2, and OCT4 expression was evaluated by immunochemistry in 348 surgically-treated HNSCC, and correlated with clinicopathological parameters and patient outcomes. mRNA expression was further analyzed in 530 The Cancer Genome Atlas (TCGA) HNSCC. NANOG protein expression was detected in 250 (72%) cases, more frequently in patients with lymph node metastasis (p = 0.003), and was an independent predictor of better survival in multivariate analysis. While OCT4 expression was undetectable, SOX2 expression was observed in 105 (30%) cases, and strongly correlated with NANOG expression. Combined expression of both proteins showed the highest survival rates, and double-negative cases the worst survival. Strikingly, the impact of NANOG and SOX2 on outcome varied depending on tumor site and lymph node infiltration, specifically showing prognostic significance in pharyngeal tumors. Correlation between NANOG and SOX2 at mRNA and protein was specifically observed in node positive (N+) patients, and consistently correlated with better survival rates. According to our findings, NANOG protein expression is frequent in HNSCC, thereby emerging as an independent predictor of better prognosis in pharyngeal tumors. Moreover, this study uncovers a differential impact of NANOG and SOX2 expression on HNSCC prognosis, depending on tumor site and lymph node infiltration, which could facilitate high-risk patient stratification.

An Integrated Genomic Strategy to Identify CHRNB4 as a Diagnostic/Prognostic Biomarker for Targeted Therapy in Head and Neck Cancer

Although many studies have shown the association between smoking and the increased incidence and adverse prognosis of head and neck squamous cell carcinoma (HNSCC), the mechanisms and pharmaceutical targets involved remain unclear. Here, we integrated gene expression signatures, genetic alterations, and survival analyses to identify prognostic indicators and therapeutic targets for smoking HNSCC patients, and we discovered that the FDA-approved drug varenicline inhibits the target for cancer cell migration/invasion. We first identified 18 smoking-related and prognostic genes for HNSCC by using RNA-Seq and clinical follow-up data. One of these genes, CHRNB4 (neuronal acetylcholine receptor subunit beta-4), increased the risk of death by approximately threefold in CHRNB4-high expression smokers compared to CHRNB4-low expression smokers (log rank, p = 0.00042; hazard ratio, 2.82; 95% CI, 1.55–5.14), former smokers, and non-smokers. Furthermore, we examined the functional enrichment of co-regulated genes of CHRNB4 and its 246 frequently occurring copy number alterations (CNAs). We found that these genes were involved in promoting angiogenesis, resisting cell death, and sustaining proliferation, and contributed to much worse outcomes for CHRNB4-high patients. Finally, we performed CHRNB4 gene editing and drug inhibition assays, and the results validate these observations. In summary, our study suggests that CHRNB4 is a prognostic indicator for smoking HNSCC patients and provides a potential new therapeutic drug to prevent recurrence or distant metastasis.

The current markers of cancer stem cell in oral cancers

Head and neck cancer (HNC) constitute 5% of all reported cancers. Among all, the oral cavity cancer is the most frequent type of HNC which accounts for over half of HNC cases. Mouth cancer ranks the sixth leading cause of cancer-related mortality. Generally, conventional chemotherapy has shown success at decreasing relapse and metastasis rates and improves the overall prognosis. Recently, target therapy and targeted drug delivery systems have been introduced as promising treatments. The elimination of efficiency of current therapeutic strategies due to the spared cancer stem cells that cause chemotherapy resistance, relapse and metastasis. Inefficiency methodologies in the elimination of all cancer cells in the body are a major problem that remained to be resolved before to confront the new cancer therapies. Many studies imply to cancer stem cell markers as important agents for targeted anti-cancer as well as improving chemotherapy efficiencies. The potentials of targeted cancer therapy led us to search for novel markers in the mouth cancer stem cells especially in rare cancers. The aimed of this research was, first a comprehensive critical review of the previous studies on the markers of cancer stem cells in oral cancers including oral squamous cell carcinoma, salivary gland cancers, and to highlight the most common cancer stem cell markers which have potential to be exploited as indicators for the preneoplastic lesion malignancy, oral cancer progression, and/or treatment prognosis.

The role of SOX2 overexpression in prognosis of patients with solid tumors: A meta-analysis and system review

BACKGROUND

Many studies have been done to reported the value of SRY-related HMG-box Gene 2 (SOX2) in prognosis of solid tumors. But results were not particularly consistent among these studies because of the limitations of the small sample data.

METHODS

We searched relevant studies published before November 2018 by PubMed, Web of Science and EMBASE. In this meta-analysis, hazard ratio (HR) values for overall survival (OS) were cumulatively pooled and quantitatively analyzed.

RESULTS

A meta-analysis based on 12 studies with 3318 patients was conducted to assess the potential correlation between SOX2 overexpression and OS in human solid tumors. A total of 12 studies (n = 3318) were assessed in the meta-analysis. It suggested that the high expression of SOX2 obviously indicates poor survival and prognosis in both univariate and multivariate analysis. In the univariate analysis, the combined HR for OS was 1.66 (95% confidence interval [CI]: 1.46-1.89, P < .001). The pooled HR of multivariate analysis for OS was 1.51 (95% confidence interval [CI]: 1.32-1.71, P < .001).

CONCLUSIONS

This meta-analysis indicated that the high expression level of SOX2 is significantly associated with a decline in survival of human with solid tumors. On the basis of the expression level in solid tumors, SOX2 is expected to be a meaningful prognostic biomarker and effective therapeutic target.

SOX2 for Stem Cell Therapy and Medical Use: Pros or Cons?

Stem cell transplantation is a fast-developing technique, which includes stem cell isolation, purification, and storage, and it is in high demand in the industry. In addition, advanced applications of stem cell transplantation, including differentiation, gene delivery, and reprogramming, are presently being studied in clinical trials. In contrast to somatic cells, stem cells are self-renewing and have the ability to differentiate; however, the molecular mechanisms remain unclear. SOX2 (sex-determining region Y [SRY]-box 2) is one of the well-known reprogramming factors, and it has been recognized as an oncogene associated with cancer induction. The exclusion of SOX2 in reprogramming methodologies has been used as an alternative cancer treatment approach. However, the manner by which SOX2 induces oncogenic effects remains unclear, with most studies demonstrating its regulation of the cell cycle and no insight into the maintenance of cellular stemness. For controlling certain critical pathways, including Shh and Wnt pathways, SOX2 is considered irreplaceable and is required for the normal functioning of stem cells, particularly neural stem cells. In this report, we discussed the functions of SOX2 in both stem and cancer cells, as well as how this powerful regulator can be used to control cell fate.

The expression and prognostic value of SOX2, β-catenin and survivin in esophageal squamous cell carcinoma

Aim: We mainly explored the effect of SOX2, β-catenin and survivin on prognosis in esophageal squamous cell carcinoma. Materials & methods: Immunohistochemistry was used to examine the expression of SOX2, β-catenin and survivin. χ² test was used to analyze the relationship between proteins and clinicopathological parameters. Survival analysis was used to investigate the effect of three proteins on prognosis. Results: SOX2 was related to lymph node metastasis (p = 0.004) and vascular invasion (p = 0.041). β-catenin was associated with depth of invasion (p = 0.014), lymph node metastasis (p = 0.032) and postoperative chemoradiotherapy (p < 0.001). Survivin was related to gender (p = 0.022) and nerve invasion (p = 0.014). There was a positive correlation between SOX2 and β-catenin. Patients with SOX2 and β-catenin overexpression had poor prognosis. Survivin-positive patients who received postoperative chemoradiotherapy had a short time. Conclusion: SOX2, β-catenin and survivin can be used as prognostic markers of esophageal squamous cell carcinoma.

CD200 Induces Epithelial-to-Mesenchymal Transition in Head and Neck Squamous Cell Carcinoma via β-Catenin-Mediated Nuclear Translocation

The membrane glycoprotein CD200 binds to its receptor CD200R1 and induces tolerance, mainly in cells of the myeloid lineage; however, information regarding its role in solid tumors is limited. Here, we investigated whether CD200 expression, which is enriched mainly in high-grade head and neck squamous cell carcinoma (HNSCC), correlates with cancer progression, particularly the epithelial-to-mesenchymal transition (EMT). The forced overexpression of CD200 in the HNSCC cell line, UMSCC84, not only increased the expression of EMT-related genes, but also enhanced invasiveness. The cleaved cytoplasmic domain of CD200 interacted with β-catenin in the cytosol, was translocated to the nucleus, and eventually enhanced EMT-related gene expression. CD200 increased the invasiveness of mouse tonsillar epithelium immortalized with E6, E7, and Ras (MEER), a model of tonsillar squamous cell carcinoma. siRNA inhibition of CD200 or extracellular domain of CD200R1 down-regulated the expression of EMT-related genes and decreased invasiveness. Consistently, compared to CD200-null MEER tumors, subcutaneous CD200-expressing MEER tumors showed significantly increased metastatic migration into draining lymph nodes. Our study demonstrates a novel and unique role of CD200 in inducing EMT, suggesting the potential therapeutic target for blocking solid cancer progression.

Leading edge or tumor core: Intratumor cancer stem cell niches in oral cavity squamous cell carcinoma and their association with stem cell function

OBJECTIVES

To describe differences in cancer stem cell (CSC) presence and behavior associated with their intratumor compartment of origin using a patient-derived xenograft (PDX) model of oral cavity squamous cell carcinoma (OCSCC).

MATERIALS AND METHODS

Four HPV-negative OCSCC PDX cases were selected (CUHN004, CUHN013, CUHN096, CUHN111) and the percentage of CSCs (ALDH⁺CD44^high) was measured in the tumor Leading Edge (LE) and Core compartments of each PDX tumor case via fluorescence activated cell sorting (FACS). The fraction of cells in the proliferative phase was measured by Ki-67 labelling index of paraffin embedded tissue. The proliferation and invasion of LE versus Core CSCs were compared using sphere and Matrigel invasion assays, respectively.

RESULTS

Both CUHN111 and CUHN004 demonstrate CSC enrichment in their LE compartments while CUHN013 and CUHN096 show no intratumor difference. Cases with LE CSC enrichment demonstrate greater Ki-67 labelling at the LE. CSC proliferative potential, assessed by sphere formation, reveals greater sphere formation in CUHN111 LE CSCs, but no difference between CUHN013 LE and Core CSCs. CUHN111 CSCs do not demonstrate an intratumor difference in invasiveness while CUHN013 LE CSCs are more invasive than Core CSCs.

CONCLUSION

A discrete intratumor CSC niche is present in a subset of OCSCC PDX tumors. The CSC functional phenotype with regard to proliferation and invasion is associated with the intratumor compartment of origin of the CSC: LE or Core. These individual functional characteristics appear to be modulated independently of one another and independently of the presence of an intratumor CSC niche.

Differential expression of claudin‑4, occludin, SOX2 and proliferating cell nuclear antigen between basaloid squamous cell carcinoma and squamous cell carcinoma

Basaloid squamous cell carcinomas (BSCCs) in oral lesions are extremely rare, and the histology is not well understood. Histologically, they are often similar to conventional squamous cell carcinoma (SCC). The present study was designed with an aim to distinguish BSCC from SCC using claudin‑4, occludin, SRY‑box 2 (SOX2) and proliferating cell nuclear antigen (PCNA) immunoreactivities and staining patterns. Three BSCCs (with abundant, with moderate, and without squamous components) specimens and 20 SCC specimens were selected for comparison of their immunoreactivity. These specimens were stained with claudin‑4, occludin, SOX2 and PCNA. In addition to histological analysis, the expression of claudin‑4, occludin and PCNA was determined in oral cancer HSC2 and HSC3 cells with or without SOX2 overexpression, and cell proliferation was determined by XTT assay. Claudin‑4 had strong and occludin had weak immunoreactivity as detected in the membrane of squamous components of BSCC but not in cancer cells. No obvious detection of squamous components and cancer cells were observed in SCC. SOX2 and PCNA immunoreactivities in SCC had dot‑like staining patterns in the nuclei of partial and marginal cancer cells. In contrast, in BSCCs, SOX2 and PCNA had diffuse staining patterns in almost all cancer cells. SOX2 overexpression had little effect on the expression levels of claudin‑4, occludin and PCNA. It also had little effect on the cell proliferation of HSC2 and HSC3 cells. Differences in immunoreactivity and staining pattern may be valuable to distinguish between BSCC and SCC in diagnosis.

A subtype of oral, laryngeal, esophageal, and lung, squamous cell carcinoma with high levels of TrkB-T1 neurotrophin receptor mRNA

Background

The NTRK2 genetic locus encodes neurotrophin membrane receptors that play an important role in normal neural tissue plasticity, growth, and survival. One NTRK2-encoded protein is TrkB-FL, which can regulate multiple pathways relevant to cancer. A second NTRK2 gene mRNA isoform encodes TrkB-T1, a receptor that has a different cytoplasmic domain encoded in a mRNA with a unique 3′ terminal exon.

Method

Tumors from The Cancer Genome Atlas (TCGA) and other studies were classified according to the expression of a single form of NTRK2 mRNA, TrkB-T1, identified by its unique 3′ terminal exon. Analysis of differentially expressed genes in TrkB-T1 high expressers was done to determine if tumors enriched for TrkB-T1 mRNA were a uniform group independent of anatomic site.

Results

The mRNA for TrkB-T1 is the most abundant NTRK2 gene mRNA in all squamous cell carcinomas (SCCs) in the TCGA database. Comparison of larynx SCC high TrkB-T1 RNA expressers to low expressers (n = 96) revealed gene expression differences consistent with the high TrkB-T1 tumors being more neural-like. The upregulated genes in the TrkB-T1 RNA high expressers also showed enrichment of pathways involved in retinol metabolism, hedgehog signaling, and the Nfe2l2 response, among other pathways. An examination of oral, esophagus, and lung SCCs (n = 284, 97, 501) showed induction of the same pathways among tumors that expressed high levels of TrkB-T1 mRNA. Proteins associated with regulation of the sonic hedgehog pathway, and the Nfe2l2 response, Tp63, and Keap1 and p62/SQSTM1 proteins, showed differential expression in larynx, oral and lung high TrkB1-T1 expresser SCCs. Unexpectantly, the relationship of high level TrkB-T1 expression to patient outcomes was SCC anatomic site specific. High TrkB-T1 mRNA levels in laryngeal SCC correlated with poor survival, but the opposite was true for lung SCC. This may be because pathways enriched in the TrkB high expressers, like those involving oncogenes NFE2L2, PIK3CA, and SOX2, are known to have SCC anatomic site-specific effects on progression.

Conclusions

High level TrkB-T1 mRNA is a marker of a distinct SCC subtype enriched for at least 3 pathways relevant to tumor progression: Nfe2l2 response, retinol metabolism, and hedgehog signaling.

Electronic supplementary material

The online version of this article (10.1186/s12885-019-5789-8) contains supplementary material, which is available to authorized users.

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.

Combined class I histone deacetylase and mTORC1/C2 inhibition suppresses the initiation and recurrence of oral squamous cell carcinomas by repressing SOX2

Treatment of oral squamous cell carcinoma (OSCC) remains a challenge because of the lack of effective early treatment strategies and high incidence of relapse. Here, we showed that combined 4SC-202 (a novel selective class I HDAC inhibitor) and INK128 (a selective mTORC1/C2 inhibitor) treatment exhibited synergistic effects on inhibiting cell growth, sphere-forming ability, subcutaneous tumor formation and ALDH1⁺ cancer stem cells (CSCs) in OSCC. The initiation of OSCC was significantly inhibited by combined treatment in 4NQO-induced rat model. In addition, upregulated SOX2 was associated with advanced and metastatic tumors in OSCC patients and was responsible for the drug-resistance property of OSCC cells. The inhibitory effect of combined treatment on cell viability and ALDH1⁺ CSCs were attenuated by SOX2 verexpression. Furthermore, combined treatment can effectively overcome chemoresistance and inhibit the growth of recurrent OSCC in vitro and in vivo. Mechanistically, 4SC-202 and INK128 repressed SOX2 expression through miR-429/miR-1181-mediated mRNA degradation and preventing cap-dependent mRNA translation, respectively. These results suggest that combined class I histone deacetylase and mTORC1/C2 inhibition suppresses the carcinogenesis and recurrence of OSCC by repressing SOX2.

Histologic pattern of invasion and epithelial-mesenchymal phenotype predict prognosis in squamous carcinoma of the head and neck

INTRODUCTION

Disruption of E-cadherin function and increased expression of vimentin and the transcriptional oncogene, SOX2, are thought to characterize epithelial to mesenchymal transition (EMT) in HNSCC that contributes to invasive and metastatic behavior. To determine if such changes relate to prognosis or host immune response, expression of these markers and correlations with clinical characteristics, histologic worst pattern of invasion (WPOI) and tumor infiltrating lymphocytes (TIL) and survival were assessed.

METHODS

Immunohistologic expression of markers was determined in tissue microarrays from 274 previously untreated HNSCC patients. Expression was correlated with levels of TILs in microcores and WPOI in biopsy specimens. Correlations were assessed by Kruskal-Wallis testing and Spearman correlation coefficients where appropriate. Overall and relapse-free survival were analyzed with Cox proportional hazards models. Median follow up was 60.0 months.

RESULTS

Loss of E-cadherin expression was significantly associated with low or absent SOX2 expression (R = 0.433, p < 0.0001). SOX2 expression and low grade WPOI were significantly associated with favorable overall (OS) and relapse free (RFS) survival in multivariable analysis. E-cadherin expression did not correlate with TILs, however WPOI score correlated indirectly with CD4, CD8, and FoxP3 levels. When grouped by primary treatment, lower grades (1, 2) of WPOI predicted improved RFS and OS in patients treated with primary surgery but not for patients treated with chemoradiation.

CONCLUSION

The findings suggest that SOX2 expression and WPOI are significant prognostic factors and that WPOI correlates with decreased T cell infiltration. The combination of markers and TILs might be useful in selecting patients for primary surgery.

High Expression of EpCAM and Sox2 is a Positive Prognosticator of Clinical Outcome for Head and Neck Carcinoma

Locally advanced head and neck squamous cell carcinomas (HNSCC) have limited prognosis due to frequent treatment failure. Currently, TNM-classification and human papillomavirus (HPV) infection are the sole clinical prognosticators of outcome. Tumor heterogeneity and stemness based on epithelial-mesenchymal-transition reportedly associate with therapy resistance. The capacity of epithelial marker EpCAM (EpEX), stemness regulator Sox2 and mesenchymal marker vimentin to predict clinical outcome of HSNCC patients was assessed upon immunohistochemistry staining in two cohorts of HNSCC patients treated with surgery and adjuvant radio (chemo) therapy (n = 94) and primary radio (chemo) therapy (n = 94), respectively. Prognostic values with respect to overall, disease-free and disease-specific survival were assessed in uni- and multivariate cox proportional hazard models to generate integrated risk scores. EpEX, Sox2 and vimentin displayed substantial inter- and intratumoral heterogeneity. EpEX^high and Sox2^high predicted improved clinical outcome in the discovery cohort and in the HPV-negative sub-cohort. EpEX^high and Sox2^high were confirmed as prognosticators of clinical outcome in the validation cohort treated with definitive radio(chemo)therapy. Importantly, EpEX^high identified patients with improved survival within the HPV-negative subgroup of the validation cohort. Hence, Sox2^high and particularly EpEX^high have potential as tools to predict clinical performance of HNSCC patients, foremost HPV-negative cases, in the frame of molecular-guided treatment decision-making.

The expression and biological information analysis of miR-375-3p in head and neck squamous cell carcinoma based on 1825 samples from GEO, TCGA, and peer-reviewed publications

BACKGROUND

The specific expression level and clinical significance of miR-375-3p in HNSCC had not been fully stated, as well as the overall biological function and molecular mechanisms. Therefore, we purpose to carry out a comprehensive meta-analysis to further explore the clinical significance and potential function mechanism of miR-375-3p in HNSCC.

METHODS

HNSCC-related data was gained from Gene Expression Omnibus (GEO), The Cancer Genome Atlas (TCGA), and peer-reviewed journals. A meta-analysis was carried out to comprehensively explore the relationship between miR-375-3p expression level and clinicopathological features of HNSCC. And summary receiver operating characteristic (SROC) curve analysis was applied for evaluating disease diagnosis value of miR-375-3p. In addition, a biological pathway analysis was also performed to assess the possible molecular mechanism of miR-375-3p in HNSCC.

RESULTS

A total of 24 available records and references were added into analysis. The overall pooled meta-analysis outcome revealed a relatively lower expression level of miR-375-3p in HNSCC specimens than that in non-cancerous controls (P < 0.001). And SROC curve analysis showed that the pooled area under the SROC curve (AUC) was 0.90 (95%CI: 0.88-0.93). In addition, biological pathway analysis indicated that LAMC1, EDIL3, FN1, VEGFA, IGF2BP2, and IGF2BP3 maybe the latent target genes of miR-375-3p, which were greatly enriched in the pathways of beta3 integrin cell surface interactions and the binding of RNA via the insulin-like growth factor-2 mRNA-binding protein (IGF2BPs/IMPs/VICKZs).

CONCLUSION

MiR-375-3p expression clearly decreased in HNSCC samples compared with non-cancerous controls. Meanwhile, miR-375-3p may serve as a tumor suppressor via regulating tumor-related genes LAMC1, EDIL3, FN1, VEGFA, IGF2BP2, and IGF2BP3 in HNSCC.

SOX2 Promotes Cell Proliferation and Metastasis in Triple Negative Breast Cancer

This study explored the expression, biological function and prognostic role of SOX2 in triple negative breast cancer (TNBC). Quantitative real-time PCR and immunohistochemistry were used to detect the expression of SOX2 in TNBC cell lines and clinical tissues. MTT assay, Transwell assay, flow cytometry and xenograft mouse model were used to assess the biological functions of SOX2. It was found that SOX2 was up-regulated in both TNBC cell lines and clinical tissues. High expression of SOX2 was associated with shorter overall survival and disease free survival. Moreover, inhibition of SOX2 suppressed cell proliferation and invasion, induced cell apoptosis in vitro, and suppressed tumorigenesis and metastasis in vivo. In addition, analysis of TNM stage and lymph nodes infiltration among the 237 TNBC patients by paired χ² test showed that SOX2 was inversely correlated with tumor status, our findings provided evidence that SOX2 acts as a tumor promoter in TNBC and inhibition of SOX2 could be a potential therapeutic strategy for TNBC.