The Progressive Mutagenic Effects of Acidic Bile Refluxate in Hypopharyngeal Squamous Cell Carcinogenesis: New Insights

Novel non-invasive molecular signatures for oral cavity cancer, by whole transcriptome and small non-coding RNA sequencing analyses: Predicted association with PI3K/AKT/mTOR pathway

INTRODUCTION

Identification of molecular biomarkers in the saliva and serum of oral cavity cancer patients represents a first step in the development of essential and efficient clinical tools for early detection and post-treatment monitoring. We hypothesized that molecular analyses of paired saliva and serum samples from an individual would likely yield better results than analyses of either serum or saliva alone.

MATERIALS AND METHODS

We performed whole-transcriptome and small non-coding RNA sequencing analyses on 32 samples of saliva and serum collected from the same patients with oral squamous cell carcinoma (OSCC) and healthy controls (HC).

RESULTS

We identified 12 novel saliva and serum miRNAs and a panel of unique miRNA and mRNA signatures, significantly differentially expressed in OSCC patients relative to HC (log2 fold change: 2.6-26.8; DE: 0.02-0.000001). We utilized a combined panel of the 10 top-deregulated miRNAs and mRNAs and evaluated their putative diagnostic potential (>87% sensitivity; 100% specificity), recommending seven of them for further validation. We also identified unique saliva and serum miRNAs associated with OSCC and smoking history (OSCC smokers vs. never-smokers or HC: log2 fold change: 22-23; DE: 0.00003-0.000000001). Functional and pathway analyses indicated interactions between the discovered OSCC-related non-invasive miRNAs and mRNAs and their targets, through PI3K/AKT/mTOR signaling.

CONCLUSION

Our data support our hypothesis that using paired saliva and serum from the same individuals and deep sequencing analyses can provide unique combined mRNA and miRNA signatures associated with canonical pathways that may have a diagnostic advantage relative to saliva or serum alone and may be useful for clinical testing. We believe this data will contribute to effective preventive care by post-treatment monitoring of patients, as well as suggesting potential targets for therapeutic approaches.

A Novel Saliva and Serum miRNA Panel as a Potential Useful Index for Oral Cancer and the Association of miR-21 with Smoking History: a Pilot Study

Tobacco use is implicated in the carcinogenesis of oral squamous cell carcinoma (OSCC), which is associated with poor survival if not diagnosed early. Identification of novel noninvasive, highly sensitive, and cost-effective diagnostic and risk assessment methods for OSCC would improve early detection. Here, we report a pilot study assessing salivary and serum miRNAs associated with OSCC and stratified by smoking status. Saliva and paired serum samples were collected from 23 patients with OSCC and 21 healthy volunteers, with an equal number of smokers and nonsmokers in each group. Twenty head and neck cancer-related miRNAs were quantified by qPCR (dual-labeled LNA probes) and analyzed by Welch t test (95% confidence interval). Four saliva miRNAs, miR-21, miR-136, miR-3928, and miR-29B, showed statistically significant overexpression in OSCC versus healthy controls (P < 0.05). miR-21 was statistically significantly overexpressed in OSCC smokers versus nonsmokers (P = 0.006). Salivary miR-21, miR-136, and miR-3928, and serum miR-21 and miR-136, showed statistically significant differential expression in early-stage tumors versus controls (P < 0.05), particularly miR-21 in smokers (P < 0.005). This pilot study provides a novel panel of saliva and serum miRNAs associated with oral cancer. Further validation as a potential useful index of oral cancer, particularly miR-21 in smokers and early-stage OSCC is warranted.

PREVENTION RELEVANCE

Saliva and serum miR-21, miR-136, miR-3928, and miR-29B, are potentially associated with oral cancer even at an early stage, especially miR-21 in individuals with a smoking history, a further validation in a larger cohort of subjects with premalignant and early malignant lesions need to confirm.

Gastric cancer after Bariatric Bypass Surgery. Do they relate? (A Systematic Review)

Bariatric bypass surgery has been an effective treatment for morbid obesity. However, there is an increasing number of reported cases of gastric cancer after bypass surgery. Our systematic review showed an increasing trend of gastric cancer cases after bariatric bypass surgery in the last decade, mostly located in the excluded stomach (77%) and diagnosed in an advanced stage. In addition to known risk factors such as tobacco smoking (17%), H. pylori infection (6%), and family history of gastric cancer (3%), bile reflux, a recently proposed cancer-promoting factor, was also estimated in 18% of the cases. Our data suggest that gastric cancer risk assessment should be considered before gastric bypass surgery, and further investigations are needed to determine the value of post-operative gastric cancer surveillance.

The Effect of Tobacco Smoke N-Nitrosamines, NNK and NDEA, and Nicotine, on DNA Mismatch Repair Mechanism and miRNA Markers, in Hypopharyngeal Squamous Cell Carcinoma: An In Vivo Model and Clinical Evidence

Deregulation of the DNA mismatch repair (MMR) mechanism has been linked to poor prognosis of upper aerodigestive tract cancers. Our recent in vitro data have provided evidence of crosstalk between deregulated miRNAs and MMR genes, caused by tobacco smoke (TS) N-Nitrosamines, 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK), in hypopharyngeal cells. Here, we explored whether chronic exposure to TS components can affect MMR mechanism and miRNA profiles in hypopharyngeal mucosa. Using a mouse model (C57Bl/6J wild type) of in vivo 14-week exposure to NNK (0.2 mmol/L) and N-Nitrosodiethylamine (NDEA; 0.004 mmol/L), with or without nicotine (0.02 μmol/L), we provide direct evidence that TS components can promote dysplasia, significant downregulation of Msh2 and Mlh1 genes and deregulation of miR-21, miR-155, miR-34a, and miR-451a. By analyzing eight human specimens from tobacco smokers and eight controls, we provide clinical evidence of a significant reduction in hMSH2 and hMLH1 mRNAs in hypopharyngeal squamous cell carcinoma (HSCC). In summary, deregulation of the MMR mechanism and miRNAs is caused by chronic exposure to TS-related N-Nitrosamines, with or without nicotine, in the early stages of upper aerodigestive tract carcinogenesis, and can also be detected in human HSCC. Thus, we encourage future studies to further elucidate a possible in vivo dose-dependent effect of individual or combined N-Nitrosamines, NNK and/or NDEA, and nicotine, on the MMR mechanism and their clinical testing to elaborate prognosis and risk assessment.

The Role of PARP ‐1 and NF‐κB in Bile‐Induced DNA Damage and Oncogenic Profile in Hypopharyngeal Cells

OBJECTIVES/HYPOTHESIS

We recently documented that acidic bile, a gastroesophageal reflux content, can cause invasive hypopharyngeal squamous cell carcinoma, by inducing widespread DNA damage and promoting nuclear factor kappa B (NF-κB)-related oncogenic molecular events. Poly or adenosine diphosphate (ADP)-ribose polymerase-1 (PARP-1), a sensitive sensor of DNA damage, may interact with NF-κB. We hypothesized that PARP-1 is activated in hypopharyngeal cells (HCs) with marked DNA damage caused by acidic bile, hence there is an association between PARP-1 and NF-κB activation or its related oncogenic profile, in this process.

STUDY DESIGN

In vitro study.

METHODS

We targeted PARP-1 and NF-κB(p65), using pharmacologic inhibitors, 1.0 μM Rucaparib (AG014699) and 10 μM BAY 11-7082 {3-[4=methylphenyl)sulfonyl]-(2E)-propenenitrile}, respectively, or silencing their gene expression (siRNAs) and used immunofluorescence, luciferase, cell viability, direct enzyme-linked immunosorbent assays, and qPCR analysis to detect the effect of targeting PARP-1 or NF-κB in acidic bile-induced DNA damage, PARP-1, p-NF-κB, and B-cell lymphoma 2 (Bcl-2) expression, as well as NF-κB transcriptional activity, cell survival, and mRNA oncogenic phenotype in HCs.

RESULTS

We showed that (i) PARP-1 is overexpressed by acidic bile, (ii) targeting NF-κB adequately prevents the acidic bile-induced DNA double-strand breaks (DSBs) by gamma H2A histone family member X (γH2AX), oxidative DNA/RNA damage, PARP-1 overexpression, anti-apoptotic mRNA phenotype, and cell survival, whereas (iii) targeting PARP-1 preserves elevated DNA damage, NF-κB activation, and anti-apoptotic phenotype.

CONCLUSION

We document for the first time that the activation of PARP-1 is an early event during bile reflux-related head and neck carcinogenesis and that NF-κB can mediate DNA damage and PARP-1 activation. Our data encourage further investigation into how acidic bile-induced activated NF-κB mediates DNA damage in hypopharyngeal carcinogenesis.

LEVEL OF EVIDENCE

NA Laryngoscope, 133:1146-1155, 2023.

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.

Effects of acids, pepsin, bile acids, and trypsin on laryngopharyngeal reflux diseases: physiopathology and therapeutic targets

PURPOSE

Laryngopharyngeal reflux disease (LPRD) is a general term for the reflux of gastroduodenal contents into the laryngopharynx, oropharynx and even the nasopharynx, causing a series of symptoms and signs. Currently, little is known regarding the physiopathology of LPRD, and proton pump inhibitors (PPIs) are the drugs of choice for treatment. Although acid reflux plays a critical role in LPRD, PPIs fail to relieve symptoms in up to 40% of patients with LPRD. The influence of other reflux substances on LPRD, including pepsin, bile acid, and trypsin, has received increasing attention. Clarification of the substances involved in LPRD is the basis for LPRD treatment.

METHODS

A review of the effects of acids, pepsin, bile acids, and trypsin on laryngopharyngeal reflux diseases was conducted in PubMed.

RESULTS

Different reflux substances have different effects on LPRD, which will cause various symptoms, inflammatory diseases and neoplastic diseases of the laryngopharynx. For LPRD caused by different reflux substances, 24-h multichannel intraluminal impedance combined with pH-metry (MII-pH), salivary pepsin, bile acid and other tests should be established so that different drugs and treatment courses can be used to provide patients with more personalized treatment plans.

CONCLUSION

This article summarizes the research progress of different reflux substances on the pathogenesis, detection index and treatment of LPRD and lays a theoretical foundation to develop target drugs and clinical diagnosis and treatment.

Targeting STAT3 prevents bile reflux-induced oncogenic molecular events linked to hypopharyngeal carcinogenesis

The signal transducer and activator of transcription 3 (STAT3) oncogene is a transcription factor with a central role in head and neck cancer. Hypopharyngeal cells (HCs) exposed to acidic bile present aberrant activation of STAT3, possibly contributing to its oncogenic effect. We hypothesized that STAT3 contributes substantially to the bile reflux‐induced molecular oncogenic profile, which can be suppressed by STAT3 silencing or pharmacological inhibition. To explore our hypothesis, we targeted the STAT3 pathway, by knocking down STAT3 (STAT3 siRNA), and inhibiting STAT3 phosphorylation (Nifuroxazide) or dimerization (SI3‐201; STA‐21), in acidic bile (pH 4.0)‐exposed human HCs. Immunofluorescence, luciferase assay, Western blot, enzyme‐linked immunosorbent assay and qPCR analyses revealed that STAT3 knockdown or pharmacologic inhibition significantly suppressed acidic bile‐induced STAT3 activation and its transcriptional activity, Bcl‐2 overexpression, transcriptional activation of IL6, TNF‐α, BCL2, EGFR, STAT3, RELA(p65), REL and WNT5A, and cell survival. Our novel findings document the important role of STAT3 in bile reflux‐related molecular oncogenic events, which can be dramatically prevented by STAT3 silencing. STA‐21, SI3‐201 or Nifuroxazide effectively inhibited STAT3 and cancer‐related inflammatory phenotype, encouraging their single or combined application in preventive or therapeutic strategies of bile reflux‐related hypopharyngeal carcinogenesis.

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.

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.

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.

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.