Dysregulated molecular networks in head and neck carcinogenesis

HPV-driven oncogenesis-much more than the E6 and E7 oncoproteins

High-risk human papillomaviruses are well-established drivers of several cancer types including cervical, head and neck, penile as well as anal cancers. While the E6 and E7 viral oncoproteins have proven to be critical for malignant transformation, evidence is also beginning to emerge suggesting that both host pathways and additional viral genes may also be pivotal for malignant transformation. Here, we focus on the role of host APOBEC genes, which have an important role in molecular editing including in the response to the viral DNA and their role in HPV-driven carcinogenesis. Further, we also discuss data developed suggesting the existence of HPV-derived miRNAs in HPV + tumors and their potential role in regulating the host transcriptome. Collectively, while recent advances in these two areas have added complexity to the working model of papillomavirus-induced oncogenesis, these discoveries have also shed a light onto new areas of research that will be required to fully understand the process.

Exploration of the role of AIM2/IL-1β in adult laryngeal papilloma

OBJECTIVES

Human papillomavirus (HPV) infection is closely related to upper respiratory mucosal lesions, and the most common disease is adult upper respiratory papilloma, which has a certain probability of cancer transformation.This study conducted in vitro tissue and cell experiments to explore the inflammatory mechanisms associated with HPV + adult laryngeal papilloma.

METHODS

We compared differential expression of AIM2 and IL-1β between HPV (High-risk) negative and positive adult laryngeal papilloma patients. In vitro experiments were conducted to investigate the differences in expression of AIM2, Caspase-1, and IL-1β in HPV- and HPV+ upper respiratory mucosal cells.

RESULTS

The expression level of AIM2 and IL-1β was higher in HPV (High-risk) positive papilloma tissue than HPV (High-risk) negative papilloma tissue. The expression of AIM2, Caspase-1, and IL-1β in HPV+ cells was also significantly higher than in HPV- cells.

CONCLUSIONS

The expression of IL-1β mediated by AIM2 was associated with chronic inflammation of upper respiratory mucosal tissue caused by HPV infection, and it may yet be associated with further pathological changes.

Proteomic Analysis of Biomarkers Predicting Treatment Response in Patients with Head and Neck Cancers

Head and neck cancers (HNCs) are the sixth most commonly diagnosed cancer and the eighth leading cause of cancer-related mortality worldwide, with squamous cell carcinoma being the most prevalent type. The global incidence of HNCs is steadily increasing, projected to rise by approximately 30% per year by 2030, a trend observed in both developed and undeveloped countries. This study involved serum proteomic profiling to identify predictive clinical biomarkers in cancer patients undergoing chemoradiotherapy (CRT). Fifteen HNC patients at Tikur Anbessa Specialized Hospital, Radiotherapy (RT) center in Addis Ababa were enrolled. Serum samples were collected before and after RT, and patients were classified as responders (R) or non-responders (NR). Protein concentrations in the serum were determined using the Bradford assay, followed by nano-HPLC-MS/MS for protein profiling. Progenesis QI for proteomics identified 55 differentially expressed proteins (DEPs) between R and NR, with a significance of p < 0.05 and a fold-change (FC) ≥ 1.5. The top five-up-regulated proteins included MAD1L1, PSMC2, TRIM29, C5, and SERPING1, while the top five-down-regulated proteins were RYR1, HEY2, HIF1A, TF, and CNN3. Notably, about 16.4% of the DEPs were involved in cellular responses to DNA damage from cancer treatments, encompassing proteins related to deoxyribonucleic acid (DNA) damage sensing, checkpoint activation, DNA repair, and apoptosis/cell cycle regulation. The analysis of the relative abundance of ten proteins with high confidence scores identified three DEPs: ADIPOQ, HEY2, and FUT10 as potential predictive biomarkers for treatment response. This study highlighted the identification of three potential predictive biomarkers-ADIPOQ, HEY2, and FUT10-through serum proteomic profiling in HNC patients undergoing RT, emphasizing their significance in predicting treatment response.

The impact of ERP29 on the progression of pharyngeal squamous cell carcinoma

ERP29 gene encodes a chaperone protein critical for protein folding and secretion. Previous study linked ERP29 inhibition to an elevated risk of pharynx squamous cell carcinoma (PSCC) and reduced patients' survival. However, ERP29 role in PSCC progression remains unknown. Here, we investigated ERP29 impact on PSCC progression in cisplatin (CDDP)-sensitive (FaDu and LAU-2063), CDDP-treated (FaDu-CDDP), and CDDP-resistant (FaDu-R) cells. ERP29 silencing decreased necrosis and increased migration in CDDP-sensitive, treated, and resistant cells; and reduced E-cadherin and increased vimentin immunoexpression in CDDP-sensitive 3D-spheroids. During CDDP treatment, ERP29 silencing enhanced proliferation. In CDDP-sensitive cells, ERP29 silencing upregulated genes associated with WNT, MAPK, and PI3K/AKT signaling pathways while downregulating CASP9 expression. During CDDP treatment, ERP29 silencing downregulated MDM2 and CASP9 expression. In CDDP-resistant cells, ERP29 silencing upregulated SOS1, MAPK1, AKT1, ITGAV, and CCNE1, while downregulating KRAS, JUN, MDM2, and CASP9 expression. In addition, inhibition of microRNA miR-4421 increased ERP29 expression and decreased MAPK1, AKT1, and JUN expression in CDDP-sensitive cells, as well as SOS1, MAPK1, AKT1, and ITGAV in CDDP-resistant cells. Lower ERP29 and higher miR-4421 expressions were predictive of poor survival, suggesting a potential therapeutic use for miR-4421 inhibitors. Upon validation, these findings may contribute to targeted therapies for PSCC based on ensuring ERP29 expression.

Deciphering the complex landscape of post-translational modifications on PKM2: Implications in head and neck cancer pathogenesis

In the vast landscape of human health, head and neck cancer (HNC) poses a significant health burden globally, necessitating the exploration of novel diagnostics and therapeutics. Metabolic alterations occurring within tumor microenvironment are crucial to understand the foundational cause of HNC. Post-translational modifications (PTMs) have recently emerged as a silent foe exerting a significantly heightened influence on various aspects of the biological processes associated with the onset and advancement of cancer, particularly in the context of HNC. There are numerous targets involved in HNC but recently, the enzyme pyruvate kinase M2 (PKM2) has come out as a hot target due to its involvement in glycolysis resulting in metabolic reprogramming of cancer cells. Various PTMs have been reported to affect the structure and function of PKM2 by modulating its activity. This review aims to investigate the impact of PTMs on the interaction between PKM2 and several signaling pathways and transcription factors in the context of HNC. These interactions possess significant ramification for cellular proliferation, apoptosis, angiogenesis and metastasis. This review primarily explores the role of PTMs influencing PKM2 and its involvement in tumor development. While acknowledging the significance of PKM2 interactions with other tumor regulators, the emphasis lies on dissecting PTM-related mechanisms rather than solely scrutinizing individual regulators. It lays the framework for the development of more sophisticated diagnostic tools and uncovers exciting possibilities for precision medicine essential for effectively addressing the complexity of this malignancy in a precise and focused manner.

Overcoming Resistance to Standard-of-Care Therapies for Head and Neck Squamous Cell Carcinomas

Although there have been some advances during in recent decades, the treatment of head and neck squamous cell carcinoma (HNSCC) remains challenging. Resistance is a major issue for various treatments that are used, including both the conventional standards of care (radiotherapy and platinum-based chemotherapy) and the newer EGFR and checkpoint inhibitors. In fact, all the non-surgical treatments currently used for HNSCC are associated with intrinsic and/or acquired resistance. Herein, we explore the cellular mechanisms of resistance reported in HNSCC, including those related to epigenetic factors, DNA repair defects, and several signaling pathways. This article discusses these mechanisms and possible approaches that can be used to target different pathways to sensitize HNSCC to the existing treatments, obtain better responses to new agents, and ultimately improve the patient outcomes.

Unraveling the Genetic Web: H-Ras Expression and Mutation in Oral Squamous Cell Carcinoma-A Systematic Review

BACKGROUND

Oral squamous cell carcinoma (OSCC) is a commonly occurring malignancy with complex genetic alterations contributing to its development. The H-Ras, a proto-oncogene, becomes an oncogene when mutated and has been implicated in various cancers. This systematic review aims to research to what extent H-Ras expression and mutation contribute to the development and progression of OSCC, and how does this molecular alteration impacts the clinical characteristics and prognosis in patients with OSCC.

METHODS

A thorough electronic scientific literature search was carried out in PUBMED, SCOPUS, and GOOGLE SCHOLAR databases from 2007 to 2021. The search strategy yielded 120 articles. Following aggregation and filtering all results through our inclusion and exclusion criteria total 9 articles were included in our literature review. It has also been registered with PROSPERO (CRD42023485202).

RESULTS

It was found that mutations in the Ras gene commonly reported in hotspots at codons 12, 13, and 61 resulting in the activation of downstream signaling pathways causing abnormal and uncontrolled cell growth. This systematic review has shown an increased prevalence of H-Ras mutation in well-differentiated OSCC and also the prevalence of H-Ras mutation in individuals engaging in multiple risk behaviors, particularly chewing tobacco, demonstrated a significant association with a higher prevalence of H-Ras positivity.

CONCLUSION

This review sheds light on the prevalence of H-Ras mutations, their association with clinical characteristics, and their potential implications for OSCC prognosis. It also enhances our comprehension of the molecular mechanisms that underlie OSCC and paves the way for further research into targeted treatments based on H-Ras alterations.

Ex vivo radiation sensitivity assessment for individual head and neck cancer patients using deep learning-based automated nuclei and DNA damage foci detection

Introduction

Tumor biopsy tissue response to ex vivo irradiation is potentially an interesting biomarker for in vivo tumor response, therefore, for treatment personalization. Tumor response ex vivo can be characterized by DNA damage response, expressed by the large-scale presence of DNA damage foci in tumor nuclei. Currently, characterizing tumor nuclei and DNA damage foci is a manual process that takes hours per patient and is subjective to inter-observer variability, which is not feasible in for clinical decision making. Therefore, our goal was to develop a method to automatically segment nuclei and DNA damage foci in tumor tissue samples treated with radiation ex vivo to characterize the DNA damage response, as potential biomarker for in vivo radio-sensitivity.

Methods

Oral cavity tumor tissue of 21 patients was irradiated ex vivo (5 or 0 Gy), fixated 2 h post-radiation, and used to develop our method for automated nuclei and 53BP1 foci segmentation. The segmentation model used both deep learning and conventional image-analysis techniques. The training (22 %), validation (22 %), and test set (56 %) consisted of thousands of manually segmented nuclei and foci. The segmentations and number of foci per nucleus in the test set were compared to their ground truths.

Results

The automatic nuclei and foci segmentations were highly accurate (Dice = 0.901 and Dice = 0.749, respectively). An excellent correlation (R2 = 0.802) was observed for the foci per nucleus that outperformed reported inter-observation variation. The analysis took ∼ 8 s per image.

Conclusion

This model can replace manual foci analysis for ex vivo irradiation of head-and-neck squamous cell carcinoma tissue, reduces the image-analysis time from hours to minutes, avoids the problem of inter-observer variability, enables assessment of multiple images or conditions, and provides additional information about the foci size. Thereby, it allows for reliable and rapid ex vivo radio-sensitivity assessment, as potential biomarker for response in vivo and treatment personalization.

Expression of PD-L1 and p-RPS6 in epithelial dysplasia and squamous cell carcinoma of the oral cavity

Introduction

Oral squamous cell carcinoma (OSCC) is often preceded by oral epithelial dysplasia (OED). The role of ribosomal protein S6 (RPS6) and programmed cell death ligand-1 (PD-L1) in the progression of OED to OSCC remains unclear. This study aimed to investigate the expression of phosphorylated RPS6 (p-RPS6) and PD-L1 in OSCC and OED and to examine its relationship with clinicopathological features.

Methods

Fifty-two OSCC and 48 OED cases were recruited for immunohistochemical analysis of p-RPS6 and PD-L1 expression. The expression of markers was correlated with clinicopathological features of OSCC and OED.

Results

We found p-RPS6 expression in all cases of OSCC and OED, whereas PD-L1 was expressed in 42/48 (87%) OED and in 28/52 (53%) OSCC. The patients with mild OED presented higher expression level of PD-L1 and p-RPS6 significantly, when compared to moderate-differentiated OSCC patients (p < 0.05). Moreover, we found a significant positive correlation between PD-L1 and p-RPS6 expression in OED and OSCC patients (p < 0.01). The PD-L1 expression was significantly related to more than 2 cm tumor size in OSCC patients (p = 0.007).

Discussion

Our findings suggest the upregulation of PD-L1 may be related with activation of the mTOR pathway in the early events of tumor progression and the pathogenesis of OSCC.

Unveiling the anti-cancer mechanisms of calotropin: Insights into cell growth inhibition, cell cycle arrest, and metabolic regulation in human oral squamous carcinoma cells (HSC-3)

Background

Calotropin, a cardiac glycoside obtained from the plant Calotropis gigantea, has demonstrated promising potential as an anti-tumorigenesis compound.

Objective

The main objective of this study was to investigate the potential anti-cancer properties of calotropin against HSC-3 oral squamous cancer cells and to elucidate the underlying mechanisms involved in its action.

Material and method

Calotropin were treated in HSC-3 to evaluate cell viability by MTT assay. Flow cytometry analysis divulged that calotropin G0/G1 phase cell cycle arrest and apoptosis in HSC-3 cells. Calotropin displayed inhibitory properties against aerobic glycolysis, a metabolic alteration using glucose uptaken, lactose production and LDHA activity assays. Furthermore, migration and invasion assays help that calotropin has ability to reduce the migratory and invasive of HSC-3 cells, using transwell and Matrigel assay. Validation of mRNA expression through RT-PCR. Molecular docking was implemented to validate the binding association of calotropin with apoptosis and metastatic regulating targets.

Result

The results exemplify that increasing doses of calotropin effectively hold back the HSC-3 cell progression. Migration and invasion assays help that calotropin has ability to reduce the migratory and invasive of HSC-3 cells, indicating its potential to inhibit cancer metastasis. These results imply that calotropin may influence genes linked to metastasis and apoptosis in order to achieve its beneficial effects on cancer. Docking results provided further support, showing a high binding energy between calotropin and metastasis-mediated pathways.

Conclusion

Overall, our findings shed an experimental evidence on how calotropin inhibits the HSC-3 oral squamous cancer cell growth, highlighting the drug's potential as a treatment for oral cancer. Further, investigation on in-vivo experiment is warranted to explore its potential mechanism of action and to develop a novel drug towards clinical trial.

Inducible TgfbR1 and Pten deletion in a model of tongue carcinogenesis and chemoprevention

Head and neck squamous cell carcinoma (HNSCC) is a significant public health problem, with a need for novel approaches to chemoprevention and treatment. Preclinical models that recapitulate molecular alterations that occur in clinical HNSCC patients are needed to better understand molecular and immune mechanisms of HNSCC carcinogenesis, chemoprevention, and efficacy of treatment. We optimized a mouse model of tongue carcinogenesis with discrete quantifiable tumors via conditional deletion of Tgfβr1 and Pten by intralingual injection of tamoxifen. We characterized the localized immune tumor microenvironment, metastasis, systemic immune responses, associated with tongue tumor development. We further determined the efficacy of tongue cancer chemoprevention using dietary administration of black raspberries (BRB). Three Intralingual injections of 500 µg tamoxifen to transgenic K14 Cre, floxed Tgfbr1, Pten (2cKO) knockout mice resulted in tongue tumors with histological and molecular profiles, and lymph node metastasis similar to clinical HNSCC tumors. Bcl2, Bcl-xl, Egfr, Ki-67, and Mmp9, were significantly upregulated in tongue tumors compared to surrounding epithelial tissue. CD4+ and CD8 + T cells in tumor-draining lymph nodes and tumors displayed increased surface CTLA-4 expression, suggestive of impaired T-cell activation and enhanced regulatory T-cell activity. BRB administration resulted in reduced tumor growth, enhanced T-cell infiltration to the tongue tumor microenvironment and robust antitumoral CD8+ cytotoxic T-cell activity characterized by greater granzyme B and perforin expression. Our results demonstrate that intralingual injection of tamoxifen in Tgfβr1/Pten 2cKO mice results in discrete quantifiable tumors suitable for chemoprevention and therapy of experimental HNSCC.

Single-cell and spatial dissection of precancerous lesions underlying the initiation process of oral squamous cell carcinoma

Precancerous lesions of the oral mucosa, especially those accompanied by moderate to severe dysplasia, contribute to the initiation of oral squamous cell carcinoma (OSCC). However, the cellular compositions and spatial organization of the precancerous stage and how these factors promote human OSCC initiation remain unclear. Here, we built a single-cell transcriptome atlas and a spatial transcriptome map after obtaining data from pairwise human oral mucosal biopsies of 9 individuals consisting of very early-stage OSCC, adjacent precancerous lesions with moderate to severe dysplasia, as well as a matched normal region. An altered epithelial gene-expression profile was identified which favored OSCC initiation. This observation was coupled with distinct fibroblast, monocytic, and regulatory T-cell subclusters involved in reshaping the microenvironment. In particular, a unique immune-inhibitory monocyte subtype and spatial-switching regulation of VEGF signaling were observed surrounding precancerous lesions, concertedly strengthening activities in promoting cancer initiation. Collectively, our work elucidated the cellular landscapes and roles of precancerous lesions underlying OSCC initiation, which is essential for understanding the entire OSCC initiation process and helps inform therapeutic strategies for cancer intervention.

Methyltransferase-like 3-induced N6-methyladenosine upregulation promotes oral squamous cell carcinoma by through p38

BACKGROUND

Oral squamous cell carcinoma (OSCC), a main type of squamous cell cancer, is associated with considerable morbidity and mortality. Recent reports suggested methyltransferase-like 3 (METTL3)-mediated N6-methyladenosine (m6A) modification to be an essential regulator in the fate determination of stem cells. However, the functional significance of METTL3 in OSCC remains largely unknown.

METHODS

METTL3 expression was examined in OSCC patient samples, followed by correlation analysis against clinical tumor features. Functional assays, such as assessment of surface marker expression, colony forming, BrdU incorporation, tumor xenograft assay, and m6A dot blot, were conducted to study the impact of METTL3 knockdown (KD) in OSCC cells.

RESULTS

High METTL3 expression was positively correlated with more severe clinical features of OSCC tumors. METTL3 KD caused impairment of stem-like capacities in OSCC cells, such as tumorigenicity in vivo and colony-forming ability in vitro. Furthermore, METTL3-KD and cycloleucine, a methylation inhibitor, decreased m6A levels and down-regulated p38 expression in OSCC cells. On the contrary, the impaired cell proliferation capacity of OSCC cells after METTL3-KD was restored by exogenous expression of p38.

CONCLUSION

Our findings identified m6A methyltransferase METTL3 as a key element in the regulation of tumorigenesis in OSCC.

APOBEC3B Is Co-Expressed with PKCα/NF-κB in Oral and Oropharyngeal Squamous Cell Carcinomas

The enzymatic activity of APOBEC3B (A3B) has been implicated as a prime source of mutagenesis in head and neck squamous cell carcinoma (HNSCC). The expression of Protein Kinase C α (PKCα) and Nuclear Factor-κΒ p65 (NF-κΒ p65) has been linked to the activation of the classical and the non-canonical NF-κB signaling pathways, respectively, both of which have been shown to lead to the upregulation of A3B. Accordingly, the aim of the present study was to evaluate the expression of PKCα, NF-κΒ p65 and A3B in non-HPV related oral and oropharyngeal squamous cell carcinomas (SCC), by means of immunohistochemistry and in silico methods. PKCα was expressed in 29/36 (80%) cases of oral and oropharyngeal SCCs, with 25 (69%) cases showing a PKCα+/A3B+ phenotype and only 6/36 (17%) cases showing a PKCα-/A3B+ phenotype. Εxpression of NF-κB p65 was seen in 33/35 (94%) cases of oral and oropharyngeal SCCs, with 30/35 (86%) cases showing an NF-κB p65+/A3B+ phenotype and only 2/35 (6%) cases showing an NF-κB p65-/A3B+ phenotype. In addition, mRNA expression analysis, using the UALCAN database, revealed strong expression of all three genes. These findings indicate that the expression of A3B is associated with PKCα/NF-κB p65 expression and suggest a potential role for the PKC/NF-κB signaling pathway in the development of oral and oropharyngeal cancer.

Ex Vivo Functional Assay for Evaluating Treatment Response in Tumor Tissue of Head and Neck Squamous Cell Carcinoma

BACKGROUND

Head and neck squamous cell carcinoma (HNSCC) displays a large heterogeneity in treatment response, and consequently in patient prognosis. Despite extensive efforts, no clinically validated model is available to predict tumor response. Here we describe a functional test for predicting tumor response to radiation and chemotherapy on the level of the individual patient.

METHODS

Resection material of 17 primary HNSCC patients was cultured ex vivo, irradiated or cisplatin-treated, after which the effect on tumor cell vitality was analyzed several days after treatment.

RESULTS

Ionizing radiation (IR) affected tumor cell growth and viability with a clear dose-response relationship, and marked heterogeneity between tumors was observed. After a single dose of 5Gy, proliferation in IR-sensitive tumors dropped below 30% of the untreated level, while IR-resistant tumors maintained at least 60% of proliferation. IR-sensitive tumors showed on average a twofold increase in apoptosis, as well as an increased number and size of DNA damage foci after treatment. No differences in the homologous recombination (HR) proficiency between IR-sensitive and -resistant tumors were detected. Cisplatin caused a decrease in proliferation, as well as induction of apoptosis, again with marked variation between the samples.

CONCLUSIONS

Our functional ex vivo assay discriminated between IR-sensitive and IR-resistant HNSCC tumors, and may also be suitable for predicting response to cisplatin. Its predictive value is currently under investigation in a prospective clinical study.

BTK Isoforms p80 and p65 Are Expressed in Head and Neck Squamous Cell Carcinoma (HNSCC) and Involved in Tumor Progression

Here, we describe the expression of Bruton's Tyrosine Kinase (BTK) in head and neck squamous cell carcinoma (HNSCC) cell lines as well as in primary HNSCC samples. BTK is a kinase initially thought to be expressed exclusively in cells of hematopoietic origin. Apart from the 77 kDa BTK isoform expressed in immune cells, particularly in B cells, we identified the 80 kDa and 65 kDa BTK isoforms in HNSCC, recently described as oncogenic. Importantly, we revealed that both isoforms are products of the same mRNA. By investigating the mechanism regulating oncogenic BTK-p80/p65 expression in HNSSC versus healthy or benign tissues, our data suggests that the epigenetic process of methylation might be responsible for the initiation of BTK-p80/p65 expression in HNSCC. Our findings demonstrate that chemical or genetic abrogation of BTK activity leads to inhibition of tumor progression in terms of proliferation and vascularization in vitro and in vivo. These observations were associated with cell cycle arrest and increased apoptosis and autophagy. Together, these data indicate BTK-p80 and BTK-p65 as novel HNSCC-associated oncogenes. Owing to the fact that abundant BTK expression is a characteristic feature of primary and metastatic HNSCC, targeting BTK activity appears as a promising therapeutic option for HNSCC patients.

Deoxypodophyllotoxin Induces ROS-Mediated Apoptosis by Modulating the PI3K/AKT and p38 MAPK-Dependent Signaling in Oral Squamous Cell Carcinoma

Deoxypodophyllotoxin (DPT), a naturally occurring flavonolignan, possesses several pharmacological properties, including anticancer property. However, the mechanisms underlying DPT mode of action in oral squamous cell carcinoma (OSCC) remain unknown. This study aimed to investigate the anticancer effects of DPT on OSCC and the underlying mechanisms. Results of the MTT assay revealed that DPT significantly reduced the cell viability in a time- and dose-dependent manner. Flow cytometry analysis revealed that DPT induces apoptosis in OSCC cells in a dose-dependent manner. Moreover, DPT enhanced the production of mitochondrial reactive oxygen species (ROS) in OSCC cells. Mechanistically, DPT induced apoptosis in OSCC cells by suppressing the PI3K/AKT signaling pathway while activating the p38 MAPK signaling to regulate the expression of apoptotic proteins. Treatment with SC79, an AKT activator, reversed the effects of DPT on AKT signaling in OSCC cells. Taken together, these results provide the basis for the use of DPT in combination with conventional chemotherapy for the treatment of oral cancer.

Significance of the Wnt canonical pathway in radiotoxicity via oxidative stress of electron beam radiation and its molecular control in mice

PURPOSE

Radiation triggers cell death events through signaling proteins, but the combined mechanism of these events is unexplored The Wnt canonical pathway, on the other hand, is essential for cell regeneration and cell fate determination.

AIM

The relationship between the Wnt pathway's response to radiation and its role in radiotoxicity is overlooked, even though it is a critical molecular control of the cell. The Wnt pathway has been predicted to have radioprotective properties in some reports, but the overall mechanism is unknown. We intend to investigate how this combined cascade works throughout the radiation process and its significance over radiotoxicity.

MATERIALS AND METHODS

Thirty adult mice were irradiated with electron beam radiation, and 5 served as controls. Mice were sacrificed after 24 h and 30 days of irradiation. We assessed DNA damage studies, oxidative stress parameters, mRNA profiles, protein level (liver, kidney, spleen, and germ cells), sperm viability, and motility.

OBSERVATION

The mRNA profile helps to understand how the combined cascade of the Wnt pathway and NHEJ work together during radiation to combat oxidative response and cell survival. The quantitative examination of mRNA uncovers unique critical changes in all mRNA levels in all cases, particularly in germ cells. Recuperation was likewise seen in post-30 day's radiation in the liver, spleen, and kidney followed by oxidative stress parameters, however not in germ cells. It proposes that reproductive physiology is exceptionally sensitive to radiation, even at the molecular level. It also suggests the suppression of Lef1/Axin2 could be the main reason for the permanent failure of the sperm function process. Post-irradiation likewise influences the morphology of sperm. The decrease in mRNA levels of Lef1, Axin2, Survivin, Ku70, and XRCC6 levels suggests radiation inhibits the Wnt canonical pathway and failure in DNA repair mechanisms in a coupled manner. An increase in Bax, Bcl2, and caspase3 suggests apoptosis activation followed by the decreased expression of enzymatic antioxidants.

CONCLUSION

Controlled several interlinked such as the Wnt canonical pathway, NHEJ pathway, and intrinsic apoptotic pathway execute when the whole body is exposed to radiation. These pathways decide the cell fate whether it will survive or will go to apoptosis which may further be used in a study to counterpart and better comprehend medication focus on radiation treatment.

Proteases and HPV-Induced Carcinogenesis

Simple Summary

Human papillomavirus (HPV) infection is a sexually transmitted disease with high prevalence worldwide. Although most HPV infections do not lead to cancer, some HPV types are correlated with the majority of cervical cancers, and with some anogenital and oropharyngeal cancers. Moreover, enzymes known as proteases play an essential role in the pathogenic process in HPV-induced carcinogenesis. This review highlights the role of proteases and recent epidemiological data regarding HPV-dependent carcinogenesis.

Abstract

Persistent infection with Human papillomavirus (HPV) is the main etiologic factor for pre-malignant and malignant cervical lesions. Moreover, HPV is also associated with oropharynx and other anogenital carcinomas. Cancer-causing HPV viruses classified as group 1 carcinogens include 12 HPV types, with HPV 16 and 18 being the most prevalent. High-risk HPVs express two oncoproteins, E6 and E7, the products of which are responsible for the inhibition of p53 and pRB proteins, respectively, in human keratinocytes and cellular immortalization. p53 and pRB are pleiotropic proteins that regulate the activity of several signaling pathways and gene expression. Among the important factors that are augmented in HPV-mediated carcinogenesis, proteases not only control processes involved in cellular carcinogenesis but also control the microenvironment. For instance, genetic polymorphisms of matrix metalloproteinase 1 (MMP-1) are associated with carcinoma invasiveness. Similarly, the serine protease inhibitors hepatocyte growth factor activator inhibitor-1 (HAI-1) and -2 (HAI-2) have been identified as prognostic markers for HPV-dependent cervical carcinomas. This review highlights the most crucial mechanisms involved in HPV-dependent carcinogenesis, and includes a section on the proteolytic cascades that are important for the progression of this disease and their impact on patient health, treatment, and survival.

Noxious Combination of Tobacco Smoke Nitrosamines with Bile, Deoxycholic Acid, Promotes Hypopharyngeal Squamous Cell Carcinoma, via NFκB, In Vivo

Tobacco smoking is the most known risk factor for hypopharyngeal cancer. Bile reflux has recently been documented as an independent risk factor for NFκB-mediated hypopharyngeal squamous cell carcinoma. However, the carcinogenic effect of tobacco smoke on the hypopharynx and its combination with bile has not yet been proven by direct evidence. We investigated whether in vivo chronic exposure (12-14 weeks) of murine (C57Bl/6J) hypopharyngeal epithelium to tobacco smoke components (TSC) [N-nitrosamines; 4-(N-Methyl-N-Nitrosamino)-1-(3-pyridyl)-1-butanone (0.2 mmol/L), N-nitrosodiethylamine (0.004 mmol/L)], as the sole drinking fluid 5 days per week, along with topically applied (two times/day) bile [deoxycholic acid (0.28 mmol/L)], can accelerate a possible TSC-induced neoplastic process, by enhancing NFκB activation and the associated oncogenic profile, using histologic, IHC, and qPCR analyses. We provide direct evidence of TSC-induced premalignant lesions, which can be exacerbated by the presence of bile, causing invasive carcinoma. The combined chronic exposure of the hypopharynx to TSC with bile causes advanced NFκB activation and profound overexpression of Il6, Tnf, Stat3, Egfr, Wnt5a, composing an aggressive phenotype. We document for the first time the noxious combination of bile with a known risk factor, such as tobacco smoke nitrosamines, in the development and progression of hypopharyngeal cancer, via NFκB, in vivo. The data presented here encourage further investigation into the incidence of upper aerodigestive tract cancers in smokers with bile reflux and the early identification of high-risk individuals in clinical practice. This in vivo model is also suitable for large-scale studies to reveal the nature of inflammatory-associated aerodigestive tract carcinogenesis and its targeted therapy.

PREVENTION RELEVANCE

Early assessment of bile components in refluxate of tobacco users can prevent the chronic silent progression of upper aerodigestive tract carcinogenesis. This in vivo model indicates that bile reflux might have an additive effect on the tobacco-smoke N-nitrosamines effect and could be suitable for large-scale studies of diagnostic and therapeutic interventions.

Chorioallantoic membrane tumor models highlight the effects of cisplatin compounds in oral carcinoma treatment

The European Society for Medical Oncology (ESMO) suggests the use of chemotherapy as neoadjuvant, adjuvant, and concomitant to surgery and radiotherapy for the treatment of oral carcinoma by depending on the cancer stage. The usual drug of choice belongs to the platinum compounds. In this context, the evaluation of the cancer behavior associated with the administration of standard or emerging cisplatin compounds supports the establishment of optimal cancer management. Here, we have assessed and compared the performance of cisplatin alone and contained in biodegradable nanocapsules on standardized chorioallantoic membrane (CAM) tumor models. The vascularized environment and optimized grafting procedure allowed the establishment of solid tumors. The treatments showed antitumor and anti-angiogenic activities together with deregulation of pivotal genes responsible of treatment resistance and tumor aggressiveness. This study further supports the significance of CAM tumor models in oncological research for the comprehension of the molecular mechanisms involved in tumor treatment response.

Blimp-1 Upregulation by Multiple Ligands via EGFR Transactivation Inhibits Cell Migration in Keratinocytes and Squamous Cell Carcinoma

B lymphocyte-induced maturation protein-1 (Blimp-1) is a transcriptional repressor and plays a crucial role in the regulation of development and functions of various immune cells. Currently, there is limited understanding about the regulation of Blimp-1 expression and cellular functions in keratinocytes and cancer cells. Previously we demonstrated that EGF can upregulate Blimp-1 gene expression in keratinocytes, playing a negative role in regulation of cell migration and inflammation. Because it remains unclear if Blimp-1 can be regulated by other stimuli beyond EGF, here we further investigated multiple stimuli for their regulation of Blimp-1 expression in keratinocytes and squamous cell carcinoma (SCC). We found that PMA, TNF-α, LPS, polyIC, H₂O₂ and UVB can upregulate the protein and/or mRNA levels of Blimp-1 in HaCaT and SCC cells. Concomitant EGFR activation was observed by these stimuli, and EGFR inhibitor gefitinib and Syk inhibitor can block Blimp-1 gene expression caused by PMA. Reporter assay of Blimp-1 promoter activity further indicated the involvement of AP-1 in PMA-, TNF-α-, LPS- and EGF-elicited Blimp-1 mRNA expression. Confocal microscopic data indicated the nuclear loclization of Blimp-1, and such localization was not changed by stimuli. Moreover, Blimp-1 silencing enhanced SCC cell migration. Taken together, Blimp-1 can be transcriptionally upregulated by several stimuli in keratinocytes and SCC via EGFR transactivation and AP-1 pathway. These include growth factor PMA, cytokine TNF-α, TLR ligands (LPS and polyIC), and ROS insults (H₂O₂ and UVB). The function of Blimp-1 as a negative regulator of cell migration in SCC can provide a new therapeutic target in SCC.

Assessing Long Non-coding RNAs in Tobacco-associated Oral Cancer

Cancer is one of the compelling and pegged diseases battled by clinicians and researchers worldwide. Among different types of cancer, oral cancer holds the sixth position globally. With an escalating prevalence in Asian countries, India, China, and Pakistan constitute a large proportion of total incidents of oral cancer patients in terms of new cases or deaths. This mounting prevalence is ascribed to poor oral hygiene and rampant use of substances earmarked as potential risk factors for the disease. Risk factors (dietary/lifestyle habits/occupational/environmental) trigger the activation of oncogenes, dysregulation of lncRNA and miRNA, and silence the tumor suppressor genes, which robustly contributes to the onset and progression of tumorigenesis in oral squamous cell carcinoma. Evidence suggests that specific carcinogens identified in tobacco and related products alter many cellular pathways predisposing to advanced stages of oral cancer. Long non-coding RNAs represent a broad group of heterogenous transcripts longer than 200 nucleotides which do not translate to form functional proteins. They regulate various cellular pathways by specifically interacting with other RNAs, DNA, and proteins. Their role in the pathogenesis of OSCC and other cancer is still being debated. In this review, we discuss the molecular insights of significant lncRNAs involved in some crucial deregulated pathways of tobacco-associated OSCC. The implications and challenges to harnessing the potential of lncRNAs as biomarkers in early diagnosis and targeted treatment have also been analyzed.

Identification of α1,2-fucosylated signaling and adhesion molecules in head and neck squamous cell carcinoma

Head and neck cancer is the seventh most common cancer in the world, and most cases manifest as head and neck squamous cell carcinoma. Despite the prominent role of fucosylated carbohydrate antigens in tumor cell adhesion and metastasis, little is known about the functional role of fucose-modified glycoproteins in head and neck cancer pathobiology. Inactivating polymorphisms of the fut2 gene, encoding for the α1,2-fucosyltransferase FUT2, are associated with an increased incidence of head and neck cancer among tobacco users. Moreover, the presence of the α1,2-fucosylated Lewis Y epitope, with both α1,2- and α1,3-linked fucose, has been observed in head and neck cancer tumors while invasive regions lose expression, suggesting a potential role for α1,2-fucosylation in the regulation of aggressive tumor cell characteristics. Here, we report an association between fut2 expression and head and neck cancer survival, document differential surface expression of α1,2-fucosylated epitopes in a panel of normal, dysplastic, and head and neck cancer cell lines, identify a set of potentially α1,2-fucosylated signaling and adhesion molecules including the epidermal growth factor receptor (EGFR), CD44 and integrins via tandem mass spectrometry, and finally, present evidence that EGFR is among the α1,2-fucosylated and LeY-displaying proteins in head and neck cancer. This knowledge will serve as the foundation for future studies to interrogate the role of LeY-modified and α1,2-fucosylated glycoproteins in head and neck cancer pathogenesis. Data are available via ProteomeXchange with identifier PXD029420.

Overview of Candida albicans and Human Papillomavirus (HPV) Infection Agents and their Biomolecular Mechanisms in Promoting Oral Cancer in Pediatric Patients

Oral carcinoma represents one of the most common malignancies worldwide. Oral squamous cell carcinomas (OSCCs) account over 90% of all oral malignant tumors and are characterized by high mortality in the advanced stages. Early diagnosis is often a challenge for its ambiguous appearance in early stages. Mucosal infection by the human papillomavirus (HPV) is responsible for a growing number of malignancies, particularly cervical cancer and oropharyngeal carcinomas. In addition, Candida albicans (C. albicans), which is the principal fungi involved in the oral cancer development, may induce carcinogenesis through several mechanisms, mainly promoting inflammation. Medical knowledge and research on adolescent/pediatric patients' management and prevention are in continuous evolution. Besides, microbiota can play an important role in maintaining oral health and therefore all human health. The aim of this review is to evaluate epidemiological and pathophysiological characteristics of the several biochemical pathways involved during HPV and C. albicans infections in pediatric dentistry.

The role of proteomics in the multiplexed analysis of gene alterations in human cancer

INTRODUCTION

Proteomics has played a pivotal role in identifying proteins perturbed in disease conditions when compared with healthy samples. Study of dysregulated proteins aids in identifying diagnostic markers and potential therapeutic targets. Cancer is an outcome of interplay of several such disarrayed proteins and molecular pathways which perturb cellular homeostasis, resulting in transformation. In this review, we discuss various facets of proteomic approaches, including tools and technological advancements, aiding in understanding differentially expressed molecules and signaling mechanisms.

AREAS COVERED

In this review, we have taken the approach of documenting the different methods of proteomic studies, ranging from labeling techniques, data analysis methods, and the nature of molecule detected. We summarize each technique and provide a glimpse of cancer research carried out using them, highlighting the advantages and drawbacks in comparison with others. Literature search using online resources, such as PubMed and Google Scholar were carried out for this approach.

EXPERT OPINION

Technological advancements in proteomics studies have come a long way from the study of two-dimensional mapping of proteins separated on gels in the early 1970s. Higher precision in molecular identification and quantification (high throughput), and greater number of samples analyzed have been the focus of researchers.

A protein network map of head and neck cancer reveals PIK3CA mutant drug sensitivity

[Figure: see text].

Bile reflux and hypopharyngeal cancer (Review)

Laryngopharyngeal reflux, a variant of gastroesophageal reflux disease, has been considered a risk factor in the development of hypopharyngeal cancer. Bile acids are frequently present in the gastroesophageal refluxate and their effect has been associated with inflammatory and neoplastic changes in the upper aerodigestive tract. Recent in vitro and in vivo studies have provided direct evidence of the role of acidic bile refluxate in hypopharyngeal carcinogenesis and documented the crucial role of NF-κB as a key mediator of early oncogenic molecular events in this process and also suggested a contribution of STAT3. Acidic bile can cause premalignant changes and invasive squamous cell cancer in the affected hypopharynx accompanied by DNA damage, elevated p53 expression and oncogenic mRNA and microRNA alterations, previously linked to head and neck cancer. Weakly acidic bile can also increase the risk for hypopharyngeal carcinogenesis by inducing DNA damage, exerting anti-apoptotic effects and causing precancerous lesions. The most important findings that strongly support bile reflux as an independent risk factor for hypopharyngeal cancer are presented in the current review and the underlying mechanisms are provided.

Understanding the complex pathogenesis of oral cancer: A comprehensive review

The pathogenesis of oral cancer is a complex and multifactorial process that requires a deep understanding of the underlying mechanisms involved in the development and progress of malignancy. The ever-improving comprehension of the diverse molecular characteristics of cancer, the genetic and epigenetic alterations of tumor cells, and the complex signaling pathways that are activated and frequently cross talk open up promising horizons for the discovery and application of diagnostic molecular markers and set the basis for an era of individualized management of the molecular defects underlying and governing oral premalignancy and cancer. The purpose of this article is to review the key molecular concepts that are implicated in oral carcinogenesis, especially focusing on oral squamous cell carcinoma, and to review selected biomarkers that play a substantial role in controlling the so-called "hallmarks of cancer," with special reference to recent advances that shed light on their deregulation during the different steps of oral cancer development and progression.

Kallikrein 5 Inhibition by the Lympho-Epithelial Kazal-Type Related Inhibitor Hinders Matriptase-Dependent Carcinogenesis

Head and neck squamous cell carcinoma remains challenging to treat with no improvement in survival rates over the past 50 years. Thus, there is an urgent need to discover more reliable therapeutic targets and biomarkers for HNSCC. Matriptase, a type-II transmembrane serine protease, induces malignant transformation in epithelial stem cells through proteolytic activation of pro-HGF and PAR-2, triggering PI3K-AKT-mTOR and NFKB signaling. The serine protease inhibitor lympho-epithelial Kazal-type-related inhibitor (LEKTI) inhibits the matriptase-driven proteolytic pathway, directly blocking kallikreins in epithelial differentiation. Hence, we hypothesized LEKTI could inhibit matriptase-dependent squamous cell carcinogenesis, thus implicating kallikreins in this process. Double-transgenic mice with simultaneous expression of matriptase and LEKTI under the keratin-5 promoter showed a prominent rescue of K5-Matriptase^+/0 premalignant phenotype. Notably, in DMBA-induced SCC, heterotopic co-expression of LEKTI and matriptase delayed matriptase-driven tumor incidence and progression. Co-expression of LEKTI reverted altered Kallikrein-5 expression observed in the skin of K5-Matriptase^+/0 mice, indicating that matriptase-dependent proteolytic pathway inhibition by LEKTI occurs through kallikreins. Moreover, we showed that Kallikrein-5 is necessary for PAR-2-mediated IL-8 release, YAP1-TAZ/TEAD activation, and matriptase-mediated oral squamous cell carcinoma migration. Collectively, our data identify a third signaling pathway for matriptase-dependent carcinogenesis in vivo. These findings are critical for the identification of more reliable biomarkers and effective therapeutic targets in Head and Neck cancer.

Oral epithelial dysplasia: Recognition, grading and clinical significance

Histopathological grading of epithelial dysplasia remains the principal laboratory method for assessing the risk of malignant transformation in oral potentially malignant disorders (OPMDs). Current views on the molecular pathogenesis and histological interpretation of the features of epithelial dysplasia are described, and the use of grading systems for epithelial dysplasia is discussed. Changes to the current 2017 WHO criteria for diagnosis are proposed with emphasis on the architectural features of epithelial dysplasia. The predictive values of three-grade and binary systems are summarised, and categories of epithelial dysplasia are reviewed, including lichenoid and verrucous lesions, keratosis of unknown significance, HPV-associated dysplasia, differentiated and basaloid epithelial dysplasia. The implications of finding epithelial dysplasia in an oral biopsy for clinical management are discussed from the pathologists' viewpoint.

Effect of tyrosine kinase inhibitors on cell migration and epithelial-to-mesenchymal transition in Asian head and neck cancer cell lines

BACKGROUND

We investigated the role of epidermal growth factor (EGF) and transforming growth factor α (TGFα) on Asian head and neck cancer patient cell lines; in terms of epithelial-to-mesenchymal transition (EMT) and cell migration to determine whether these changes could be reversed using tyrosine kinase inhibitors (Gefitinib and Erlotinib).

METHODS

Cell migration, protrusion and EMT were assessed using both Scatter assay and Scratch assay. Protein expression and localisation were evaluated using immunofluorescence, SDS-PAGE and Western blotting techniques to identify the involvement of phosphorylated MAPK (Thr202/Tyr204), phosphorylated EGFR (Y1068) and phosphorylated AKT (Ser473) protein expression.

RESULTS

EGF and TGFα induced an EMT-like phenotypical change, cellular protrusion and cell migration while Gefitinib and Erlotinib blocked these morphological changes and cell migration. We also examined the effect of EGF/TGF α± tyrosine kinase inhibitors on phosphorylation sites Y1068 of epidermal growth factor receptor (EGFR). Y1068 was phosphorylated in all test conditions, and all tested concentrations of inhibitors did not inhibit Y1068 phosphorylation. EGF and TGFα increased phosphorylation of MAPK (Thr202/Tyr204) residues compared with serum-free control while a one-hour pre-treatment with tyrosine kinase inhibitor(s) before addition of growth factors completely blocked this phosphorylation. Phosphorylation of Akt Ser 473 was also induced by EGF and TGFα, and a one-hour pre-treatment with the tyrosine kinas inhibitor(s) reduced this phosphorylation.

CONCLUSION

These data suggest that Gefitinib and Erlotinib prevent activation of downstream signalling proteins MAPK (Thr202/Tyr204) and Akt (Ser473) thereby blocking phenotypic change and cell migration. This study supports the potential therapeutic value of Gefitinib and Erlotinib in targeting head and neck cancer.

Persistent activation of the mammalian target of rapamycin signalling pathway in cutaneous squamous cell carcinomas in cats

BACKGROUND

Cutaneous squamous cell carcinoma (CSCC) represents the most common malignant tumour of the feline skin. Emerging evidence suggests that the phosphatidylinositol 3-kinase/Akt/mammalian target of rapamycin (PI3K/Akt/mTOR) signalling pathway may represent a potential target for pharmacological intervention in human and canine CSCC.

HYPOTHESIS/OBJECTIVES

The present study aimed to explore the expression pattern and status of activation of relevant signalling proteins of the PI3K/Akt/mTOR signalling pathway in feline CSCC.

METHODS AND MATERIALS

The expression of pEGFR^Tyr1068 , pAkt^Ser473 , pS6^Ser235/236 combined with Ki-67, and the tumour suppressor protein PTEN was evaluated by immunohistochemical analysis in 45 samples of feline CSCC, using a tissue microarray.

RESULTS

The immunodetection using phosphospecific antibodies to detect the activated forms of signalling proteins showed that the PI3K/Akt/mTOR signalling pathway is frequently activated in feline CSCCs, and may be independent of the activation of EGFR. The results also showed that PTEN expression is not significantly altered in feline CSCCs.

CONCLUSIONS AND CLINICAL IMPORTANCE

Our study shows that the persistent activation of the PI3K/Akt/mTOR signalling pathway represents a key event in feline CSCC, pointing to this signalling pathway being a potential therapeutic target in feline patients with CSCC.

Pepsin Promotes Activation of Epidermal Growth Factor Receptor and Downstream Oncogenic Pathways, at Slightly Acidic and Neutral pH, in Exposed Hypopharyngeal Cells

Pepsin refluxate is considered a risk factor for laryngopharyngeal carcinogenesis. Non-acidic pepsin was previously linked to an inflammatory and tumorigenic effect on laryngopharyngeal cells in vitro. Yet there is no clear evidence of the pepsin-effect on a specific oncogenic pathway and the importance of pH in this process. We hypothesized that less acidic pepsin triggers the activation of a specific oncogenic factor and related-signalling pathway. To explore the pepsin-effect in vitro, we performed intermittent exposure of 15 min, once per day, for a 5-day period, of human hypopharyngeal primary cells (HCs) to pepsin (1 mg/mL), at a weakly acidic pH of 5.0, a slightly acidic pH of 6.0, and a neutral pH of 7.0. We have documented that the extracellular environment at pH 6.0, and particularly pH 7.0, vs. pH 5.0, promotes the pepsin-effect on HCs, causing increased internalized pepsin and cell viability, a pronounced activation of EGFR accompanied by NF-κB and STAT3 activation, and a significant upregulation of EGFR, AKT1, mTOR, IL1β, TNF-α, RELA(p65), BCL-2, IL6 and STAT3. We herein provide new evidence of the pepsin-effect on oncogenic EGFR activation and its related-signaling pathway at neutral and slightly acidic pH in HCs, opening a window to further explore the prevention and therapeutic approach of laryngopharyngeal reflux disease.

Weakly Acidic Bile Is a Risk Factor for Hypopharyngeal Carcinogenesis Evidenced by DNA Damage, Antiapoptotic Function, and Premalignant Dysplastic Lesions In Vivo

Simple Summary

The etiologic role of biliary reflux in hypopharyngeal cancer is supported by clinical data. Although, reflux episodes often occur at pH 4.0, they can also occur at weakly acidic pH (5.5–6.0). The carcinogenic effect of bile at strongly acidic pH (pH 3.0) was recently documented in vivo. Here, we provide novel in vivo evidence that a weakly acidic pH of 5.5, similarly to a strongly acidic pH of 3.0, increases the risk of bile-related hypopharyngeal neoplasia. We document that chronic exposure of hypopharyngeal mucosa to bile at pH 5.5 promotes premalignant lesions with DNA damage, NF-κB activation, and deregulated mRNA and miRNA phenotypes, including Bcl-2 and miR-451a. The oncogenic effects of bile over a wider pH range suggests that antacid therapy may be insufficient to fully modify the effects of a bile induced oncogenic effect.

Abstract

Background: There is recent in vivo discovery documenting the carcinogenic effect of bile at strongly acidic pH 3.0 in hypopharynx, while in vitro data demonstrate that weakly acidic bile (pH 5.5) has a similar oncogenic effect. Because esophageal refluxate often occurs at pH > 4.0, here we aim to determine whether weakly acidic bile is also carcinogenic in vivo. Methods: Using 32 wild-type mice C57B16J, we performed topical application of conjugated primary bile acids with or without unconjugated secondary bile acid, deoxycholic acid (DCA), at pH 5.5 and controls, to hypopharyngeal mucosa (HM) twice per day, for 15 weeks. Results: Chronic exposure of HM to weakly acidic bile, promotes premalignant lesions with microinvasion, preceded by significant DNA/RNA oxidative damage, γH2AX (double strand breaks), NF-κB and p53 expression, overexpression of Bcl-2, and elevated Tnf and Il6 mRNAs, compared to controls. Weakly acidic bile, without DCA, upregulates the “oncomirs”, miR-21 and miR-155. The presence of DCA promotes Egfr, Wnt5a, and Rela overexpression, and a significant downregulation of “tumor suppressor” miR-451a. Conclusion: Weakly acidic pH increases the risk of bile-related hypopharyngeal neoplasia. The oncogenic properties of biliary esophageal reflux on the epithelium of the upper aerodigestive tract may not be fully modified when antacid therapy is applied. We believe that due to bile content, alternative therapeutic strategies using specific inhibitors of relevant molecular pathways or receptors may be considered in patients with refractory GERD.

Yap1 Mediates Trametinib Resistance in Head and Neck Squamous Cell Carcinomas

PURPOSE

In a head and neck squamous cell carcinoma (HNSCC) "window of opportunity" clinical trial, we reported that trametinib reduced MEK-Erk1/2 activation and resulted in tumor responses in a subset of patients. Here, we investigated resistance to trametinib and molecular correlates in HNSCC cell lines and patient samples.

EXPERIMENTAL DESIGN

HNSCC cell lines were treated with trametinib to generate resistant lines. Candidate bypass pathways were assessed using immunoblotting, CRISPR knockout, and survival assays. Effectiveness of combined trametinib and verteporfin targeting was evaluated. Patient-derived xenografts (PDXs) from responder patients were treated with trametinib and resistant tumors were analyzed. Window trial clinical samples were subjected to whole-exome and RNA sequencing.

RESULTS

HNSCC cell lines developed resistance (CAL27-TR and HSC3-TR) after prolonged trametinib exposure. Downstream effectors of the Hippo pathway were activated in CAL27-TR and HSC3-TR, and combined trametinib and verteporfin treatment resulted in synergistic treatment response. We defined the Hippo pathway effector Yap1 as an induced survival pathway promoting resistance to trametinib in HSC3-TR. Yap1 was necessary for HSC3-TR trametinib resistance, and constitutively active Yap1 was sufficient to confer resistance in parental HSC3. Analysis of trametinib neoadjuvant trial patient tumors indicated canonical MEK-Erk1/2 pathway activating mutations were infrequent, and Yap1 activity increased following trametinib treatment. Trametinib treatment of a PDX from a responder patient resulted in evolution of resistance with increased Yap1 expression and activity.

CONCLUSIONS

These studies identify a Yap1-dependent resistance to trametinib therapy in HNSCCs. Combined Yap1 and MEK targeting may represent a strategy to enhance HNSCC response.

Cancer and Stress: Does It Make a Difference to the Patient When These Two Challenges Collide?

Simple Summary

Head and neck cancers are the sixth most common cancer in the world. The burden of the disease has remained challenging over recent years despite the advances in treatments of other malignancies. The very use of the word malignancy brings about a stress response in almost all adult patients. Being told you have a tumour is not a word anyone wants to hear. We have embarked on a study which will investigate the effect of stress pathways on head and neck cancer patients and which signalling pathways may be involved. In the future, this will allow clinicians to better manage patients with head and neck cancer and reduce the patients’ stress so that this does not add to their tumour burden.

Abstract

A single head and neck Cancer (HNC) is a globally growing challenge associated with significant morbidity and mortality. The diagnosis itself can affect the patients profoundly let alone the complex and disfiguring treatment. The highly important functions of structures of the head and neck such as mastication, speech, aesthetics, identity and social interactions make a cancer diagnosis in this region even more psychologically traumatic. The emotional distress engendered as a result of functional and social disruption is certain to negatively affect health-related quality of life (HRQoL). The key biological responses to stressful events are moderated through the combined action of two systems, the hypothalamus–pituitary–adrenal axis (HPA) which releases glucocorticoids and the sympathetic nervous system (SNS) which releases catecholamines. In acute stress, these hormones help the body to regain homeostasis; however, in chronic stress their increased levels and activation of their receptors may aid in the progression of cancer. Despite ample evidence on the existence of stress in patients diagnosed with HNC, studies looking at the effect of stress on the progression of disease are scarce, compared to other cancers. This review summarises the challenges associated with HNC that make it stressful and describes how stress signalling aids in the progression of cancer. Growing evidence on the relationship between stress and HNC makes it paramount to focus future research towards a better understanding of stress and its effect on head and neck cancer.

Prognostic Correlation of an Autophagy-Related Gene Signature in Patients with Head and Neck Squamous Cell Carcinoma

Considerable evidence indicates that autophagy plays a vital role in the biological processes of various cancers. The aim of this study is to evaluate the prognostic value of autophagy-related genes in patients with head and neck squamous cell carcinoma (HNSCC). Transcriptome expression profiles and clinical data acquired from The Cancer Genome Atlas (TCGA) database were analyzed by Cox proportional hazards model and Kaplan–Meier survival analysis to screen autophagy-related prognostic genes that were significantly correlated with HNSCC patients' overall survival. Functional enrichment analyses were performed to explore biological functions of differentially expressed autophagy-related genes (ARGs) identified in HNSCC patients. Six ARGs (EGFR, HSPB8, PRKN, CDKN2A, FADD, and ITGA3) identified with significantly prognostic values for HNSCC were used to construct a risk signature that could stratify patients into the high-risk and low-risk groups. This signature demonstrated great value in predicting prognosis for HNSCC patients and was indicated as an independent prognostic factor in terms of clinicopathological characteristics (sex, age, clinical stage, histological grade, anatomic subdivision, alcohol history, smoking status, HPV status, and mutational status of the samples). The prognostic signature was also validated by data from the Gene Expression Omnibus (GEO) database and International Cancer Genome Consortium (ICGC). In conclusion, this study provides a novel autophagy-related gene signature for predicting prognosis of HNSCC patients and gives molecular insights of autophagy in HNSCC.

Epithelial Distribution of E-Cadherin, p63, and Mitotic Figures in ApoTome Images to Determine the Oncogenic Potentiality of Oral Submucous Fibrosis

The exact process of the malignant conversion of oral submucous fibrosis (OSF) to oral cancer is not fully understood. This study aimed to detect and analyze E-cadherin expression, p63 expression, and number of mitotic figures, all correlated to cancer development, in ApoTome images of oral tissues to determine the oncogenic potentiality of OSF. ApoTome images of the study groups (6 normal, 16 OSF with dysplasia, and 10 OSF without dysplasia) were recorded. Cytoplasmic and membranous E-cadherin expression, breakages of the cell membrane, and p63 expression were detected in MATLAB 2016b. The number of mitotic figures detected by MATLAB was correlated with the number of chromosomes detected by ImageJ. A Mann–Whitney U test was done to determine a significant difference between the study groups for cytoplasmic and membranous E-cadherin distribution points. Statistical significant differences were found for cytoplasmic E-cadherin distribution between normal and OSF (with dysplasia) (p = 0.0278). There was an increase in mitotic figures, p63 expression, and cytoplasmic E-cadherin expression and a decrease in membranous E-cadherin expression from normal to diseased condition. Hence, automated detection and quantification of E-cadherin, p63, and mitotic figures in ApoTome images of oral biopsies can help in determining the oncogenic potentiality of OSF.

Antitumor Activity of the Cardiac Glycoside αlDiginoside by Modulating Mcl-1 in Human Oral Squamous Cell Carcinoma Cells

We recently isolated a cardiac glycoside (CG), αldiginoside, from an indigenous plant in Taiwan, which exhibits potent tumor-suppressive efficacy in oral squamous cell carcinoma (OSCC) cell lines (SCC2095 and SCC4, IC₅₀ < 0.2 µM; 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assays). Here, we report that αldiginoside caused Sphase arrest and apoptosis, through the inhibition of a series of signaling pathways, including those mediated by cyclin E, phospho-CDC25C (p-CDC25C), and janus kinase/signal transducer and activator of transcription (JAK/STAT)3. αldiginoside induced apoptosis, as indicated by caspase activation and poly (ADP-ribose) polymerase (PARP) cleavage. Equally important, αldiginoside reduced Mcl-1 expression through protein degradation, and overexpression of Mcl-1 partially protected SCC2095 cells from αldiginoside’s cytotoxicity. Taken together, these data suggest the translational potential of αldiginoside to foster new therapeutic strategies for OSCC treatment.

Evaluating the expression of GLUT-1 in oral leukoplakia

Aim:

The aim of the present study is to analyze the role of GLUT-1 in detection of early alterations occurring in oral leukoplakia. This study was to evaluate the expression of GLUT-1 in normal oral epithelium, the expression of GLUT-1 levels in the tissue samples of oral leukoplakia and to statistically compare the expression of GLUT-1 in normal epithelium and oral leukoplakia.

Materials and Methods:

The study sample comprised formalin-fixed and paraffin-embedded tissue specimens from 23 cases of histopathologically diagnosed oral leukoplakia and formalin-fixed paraffin-embedded tissue specimens from 10 cases of normal oral mucosa. Sections were mounted on glass slide coated with Aminopropyltriethoxysilane (APES; Sigma chemical co., USA) and processed for subsequent immunohistochemical study to demonstrate GLUT-1.

Results:

GLUT-1 expression in normal oral mucosa revealed weak positivity in all 10 cases (100%). The oral leukoplakia cases showed immunopositivity in all 23 cases (100%) of which 10 cases (39.14%) demonstrated focal positivity and 13 cases (60.86%) of diffuse positivity. The results were compared statistically using ANOVA test was significant at P = 0.002.

Conclusion:

The present study shows expression of GLUT-1 in leukoplakia may be used as a reliable marker to identify the high risk group for malignant transformation.

The temporal effects of topical NF-κB inhibition, in the in vivo prevention of bile-related oncogenic mRNA and miRNA phenotypes in murine hypopharyngeal mucosa: a preclinical model

Supraesophageal bile reflux at strongly acidic pH can cause hypopharyngeal squamous cell cancer, through activation of the oncogenic NF-κB-related pathway. We hypothesize that topical pre- or post-application of pharmacologic NF-κB inhibitor, BAY 11-7082 (0.25 μmol), on murine (C57BL/6J) HM (twice a day for 10 days) can effectively inhibit acidic bile (10 mmol/l; pH 3.0) induced oncogenic molecular events, similar to prior in vitro findings. We demonstrate that the administration of BAY 11-7082, either before or after acidic bile, eliminates NF-κB activation, prevents overexpression of Bcl2, Rela, Stat3, Egfr, Tnf, Wnt5a, and deregulations of miR-192, miR-504, linked to bile reflux-related hypopharyngeal cancer. Pre- but not post-application of NF-κB inhibitor, significantly blocks overexpression of Il6 and prostaglandin H synthases 2 (Ptgs2), and reverses miR-21, miR-155, miR-99a phenotypes, supporting its early bile-induced pro-inflammatory effect. We thus provide novel evidence that topical administration of a pharmacological NF-κB inhibitor, either before or after acidic bile exposure can successfully prevent its oncogenic mRNA and miRNA phenotypes in HM, supporting the observation that co-administration of NF-κB inhibitor may not be essential in preventing early bile-related oncogenic events and encouraging a capacity for further translational exploration.

Upregulation of secreted phosphoprotein 1 affects malignant progression, prognosis, and resistance to cetuximab via the KRAS/MEK pathway in head and neck cancer

Acquired resistance is a barrier to cetuximab efficacy in patients with head and neck squamous cell carcinoma (HNSCC). Secreted phosphoprotein 1 (SPP1) is involved in various biological processes, including immune responses, cancer progression, and prognosis in many cancers, while little is known in HNSCC. Bioinformatics methods were used to identify candidate genes and further in vivo and in vitro experiments were performed to examine and validate the function of SPP1. We found that SPP1 was upregulated and has been found to have an oncogenic role in HNSCC. We further confirmed that overexpression of SPP1 affected proliferation, migration, invasion, and survival, and inhibited apoptosis, whereas silencing of SPP1 yielded opposite results to those of SPP1 overexpression. In addition, activation of the KRAS/MEK pathway contributed to the SPP1-induced malignant progression of HNSCC and resistance to cetuximab. Furthermore, SPP1 knockdown or an MEK inhibitor overcame this cetuximab-resistance pattern. Taken together, our findings for the first time identify the role of SPP1 in tumor promotion, prognostic prediction, and potential therapeutic targeting, as well as resistance to cetuximab in HNSCC.

circRNAome Profiling in Oral Carcinoma Unveils a Novel circFLNB that Mediates Tumour Growth-Regulating Transcriptional Response

Deep sequencing technologies have revealed the once uncharted non-coding transcriptome of circular RNAs (circRNAs). Despite the lack of protein-coding potential, these unorthodox yet highly stable RNA species are known to act as critical gene regulatory hubs, particularly in malignancies. However, their mechanistic implications in tumor outcome and translational potential have not been fully resolved. Using RNA-seq data, we profiled the circRNAomes of tumor specimens derived from oral squamous cell carcinoma (OSCC), which is a prevalently diagnosed cancer with a persistently low survival rate. We further catalogued dysregulated circRNAs in connection with tumorigenic progression. Using comprehensive bioinformatics analyses focused on co-expression maps and miRNA-interaction networks, we delineated the regulatory networks that are centered on circRNAs. Interestingly, we identified a tumor-associated, pro-tumorigenic circRNA, named circFLNB, that was implicated in maintaining several tumor-associated phenotypes in vitro and in vivo. Correspondingly, transcriptome profiling of circFLNB-knockdown cells showed alterations in tumor-related genes. Integrated in silico analyses further deciphered the circFLNB-targeted gene network. Together, our current study demarcates the OSCC-associated circRNAome, and unveils a novel circRNA circuit with functional implication in OSCC progression. These systems-based findings broaden mechanistic understanding of oral malignancies and raise new prospects for translational medicine.

The in vivo preventive and therapeutic properties of curcumin in bile reflux-related oncogenesis of the hypopharynx

Bile at strongly acidic pH exerts a carcinogenic effect on the hypopharynx, based upon recent pre‐clinical studies that support its role as an independent risk factor. We recently demonstrated in vitro that curcumin can prevent oncogenic profile of bile in human hypopharyngeal cells, by inhibiting NF‐κB. We hypothesize that topically applied curcumin to the hypopharynx can similarly block early oncogenic molecular events of bile, by inhibiting NF‐κB and consequently altering the expression of genes with oncogenic function. Using Mus musculus (C57Bl/6J), we topically applied curcumin (250 μmol/L; three times per day; 10 days) to the hypopharynx, 15 minutes before, 15 minutes after or in combination with bile acids (pH 3.0). Immunohistochemical analysis and qPCR revealed that topically applied curcumin either before, after or in combination with acidic bile exposure significantly suppressed its induced NF‐κB activation in regenerating epithelial cells, and overexpression of Rela, Bcl2, Egfr, Stat3, Wnt5a, Tnf, Il6, Ptgs2. Akt1 was particularly inhibited by curcumin when applied simultaneously with bile. We provide novel evidence into the preventive and therapeutic properties of topically applied curcumin in acidic bile‐induced early oncogenic molecular events in hypopharyngeal mucosa, by inhibiting NF‐κB, and shaping future translational development of effective targeted therapies using topical non‐pharmacologic inhibitors of NF‐κB.

Loss of PTEN sensitizes head and neck squamous cell carcinoma to 5-AZA-2'-deoxycytidine

OBJECTIVE

Head and neck squamous cell carcinoma (HNSCC) is an aggressive cancer associated with poor survival. Phosphatase and tensin homolog (PTEN) is a tumor suppressor gene involved in the maintenance of stem cells. DNA methylation is a known epigenetic modification involved in tumor progression. In this study, we investigated the effect of the DNA demethylation agent 5-AZA-2'-deoxycytidine (5-AZA) over HNSCC and its population of cancer stem cells (CSCs) presenting dysfunctional PTEN.

STUDY DESIGN

The effects of 5-AZA on HNSCC were evaluated by using WSU-HN13 cells. CSC was assessed by sphere-forming assays, along with the endogenous levels of aldehyde dehydrogenase. The clonogenic potential of tumors was evaluated, along with the protein expression of mTOR signaling and the identification of nuclear factor-κB (NF-κB) and epithelial-mesenchymal transition (EMT)-associated genes, using real-time polymerase chain reaction (PCR).

RESULTS

We observed that loss of PTEN enhances tumor biologic behavior, including colony- and tumor sphere-forming abilities. We also found that 5-AZA has an inhibitory effect over the CSCs and molecular markers associated with the NF-κB and EMT pathways.

CONCLUSIONS

Our findings suggest that the stratification of treatment of HNSCC based on PTEN status may identify a subset of patients who can benefit from the coadministration of 5-AZA.

JunB can enhance the transcription of IL-8 in oral squamous cell carcinoma

Proteasome inhibitor MG132 was shown to enhance the secretion of interleukin 8 (IL-8) by various cells. The enhancement is regulated by the transcription factor activator protein-1 (AP-1) at the transcriptional level. AP-1 is a dimer formed by AP-1 family proteins. The purpose of the present study was to explore the combinations of the AP-1 family proteins that contribute to MG132-driven IL-8 secretion. Oral squamous cell carcinoma-derived cell lines, Ca9-22 and HSC3, were used to demonstrate their response to MG132. IL-8 secretion was augmented by MG132 in both cell lines. c-Jun expression was detected in both the cell lines, whereas c-Fos expression was detected only in the HSC3. The influence of MG132 stimulation on c-Jun and c-Fos expression was further examined by western blot analysis. c-Jun expression was increased by MG132 stimulation, whereas c-Fos expression was not detected even after MG132 stimulation. As JunB is reported to inhibit the transcriptional activity of the AP-1 complex, we speculated that the c-Jun homodimer should contribute to IL-8 enhancement. Expression vectors encoding wild type and c-Jun mutants, M17 and M22-23, respectively, were constructed and transfected into the Ca9-22 cells. In contrast to our expectations, MG132-induced IL-8 secretion was significantly reduced in all the transfectants suggesting that other c-Jun members might form homodimers with c-Jun and contribute to IL-8 enhancement. Transfection of the cells with c-Jun or JunB small hairpin RNA (shRNA) reduced IL-8 secretion up to 50% and 65% of the control shRNA transfectant. Furthermore, cotransfection of both shRNA almost completely inhibited the IL-8 secretion. These results indicate that JunB not only inhibits but also enhances the transcription of c-Jun targets in combination with c-Jun.

β-Catenin/CBP inhibition alters epidermal growth factor receptor fucosylation status in oral squamous cell carcinoma

Epidermal growth factor receptor (EGFR) is a major driver of head and neck cancer, a devastating malignancy with a major sub-site in the oral cavity manifesting as oral squamous cell carcinoma (OSCC). EGFR is a glycoprotein receptor tyrosine kinase (RTK) whose activity is upregulated in >80% OSCC. Current anti-EGFR therapy relies on the use of cetuximab, a monoclonal antibody against EGFR, although it has had only a limited response in patients. Here, we uncover a novel mechanism regulating EGFR activity, identifying a role of the nuclear branch of the Wnt/β-catenin signaling pathway, the β-catenin/CBP axis, in control of post-translational modification of N-glycans on the EGFR. Genomic and structural analyses reveal that β-catenin/CBP signaling represses fucosylation on the antennae of N-linked glycans on EGFR. By employing nUPLC-MS/MS, we determined that malignant human OSCC cells harbor EGFR with a paucity of N-glycan antennary fucosylation, while indolent cells display higher levels of fucosylation at sites N420 and N579. Additionally, treatment with either ICG-001 or E7386, which are both small molecule inhibitors of β-catenin/CBP signaling, leads to increased transcriptional expression of fucosyltransferases FUT2 and FUT3, with a concomitant increase in EGFR N-glycan antennary fucosylation. In order to discover which fucosylated glycan epitopes are involved in the observed effect, we performed in-depth characterization of multiply-fucosylated N-glycans via tandem mass spectrometry analysis of the EGFR tryptic glycopeptides. Data are available via ProteomeXchange with identifier PXD017060. We propose that β-catenin/CBP signaling promotes EGFR oncogenic activity in OSCC by inhibiting its N-glycan antennary fucosylation through transcriptional repression of FUT2 and FUT3.