Altered MUC1 and MUC2 glycoprotein expression in laryngeal cancer

Potential ferroptosis-related diagnostic and prognostic biomarkers in laryngeal cancer

PURPOSE

Laryngeal cancer (LC) is a common malignant tumor of the head and neck. However, the relationship between ferroptosis and LC is still unclear. The aim of this study was to identify potential ferroptosis-related biomarkers for diagnosis and prognosis in LC.

METHODS

We screened differentially expressed genes (DEGs) related to ferroptosis in LC from the TCGA and FerrDb database. DEGs were identified and enrichment by GO/KEGG, GSEA, GSVA analysis. PPI analysis was performed using String and Cytoscape, then hub genes were extracted. Furthermore, ROC analysis, pan-cancer analysis, gene mutation analysis, immune infiltration correlation analysis and clinical correlation analysis of hub genes were performed.

RESULTS

A total of 59 DEGs were screened, which were more significantly enriched in biological processes and involved in HIF-1 signaling pathway, serotonergic synapse and ferroptosis. A total of 29 significant gene set pathways of LC data were performed by GSEA analysis. The GSVA analysis obtained 53 significant differential gene set pathways. The top 20 genes were identified by PPI. ROC curves revealed four of the top20 genes had a good performance, which were CA9 (AUC = 0.930), MAPK3 (AUC = 0.915), MUC1 (AUC = 0.945), and NOX4 (AUC = 0.933). Subsequent analysis found that CDKN2A has the highest mutation frequency in the top 20 gene, and IFNG had a significant correlation with age, tumor stage, degree of tumor differentiation and lymphatic clearance surgery.

CONCLUSION

Our study identified key genes closely related to ferroptosis in LC, which still need more studies to explore the mechanisms involved and may become effective clinical diagnostic and prognostic biomarkers.

Mucin 1 regulates the hypoxia response in head and neck cancer cells

Mucin 1 (MUC1) is a transmembrane glycoprotein that contributes to the cellular response in hypoxic conditions in different carcinomas. We investigated the gene expression pattern of MUCs (1, 2, 4, 5AC, 5B, 6, 15, 16, and 19) in isogenic primary (HN4 and HN30) and metastatic (HN12 and HN31) head and neck squamous cell carcinoma (HNSCC) cell lines. MUC1 was significantly up-regulated at the mRNA and protein levels in HN12 and HN31 cells, whereas, other MUCs exhibited diverse expression patterns between HNSCC cell lines. Immunohistochemistry demonstrated that MUC1 was exclusively expressed in cancer cells; however, there was no significant correlation between MUC1 expression and malignancy grading. Inducing hypoxia with CoCl₂ significantly increased cell viability, MUC1, hypoxia-inducible factor alpha (HIF-1α), and vascular endothelial growth factor A (VEGF-A) expression in HN12 cells, but not HN31 cells. Interestingly, in hypoxia, cell viability, HIF-1α and VEGF-A expression were significantly reduced in MUC1-knockdown HN12 cells. The current report is the first to demonstrate that MUC1 is required in the regulation of hypoxia-related genes in HNSCC cells. Thus, our results suggest that MUC1 modulates the hypoxic effects in HNSCC cells through HIF-1α regulation.

MUC1 confers radioresistance in head and neck squamous cell carcinoma (HNSCC) cells

Mucin 1 (MUC1), a transmembrane glycoprotein, has shown to be as the possible prognostic marker to predict the risk of aggressive head and neck squamous cell carcinoma (HNSCC). In the present study, we investigated the effect of MUC1 in HNSCC cells and the response to X-ray irradiation (IR). Here, we examined the impact of MUC1 overexpression or downexpression on clonogenic survival and apoptosis in response to X-ray irradiation (IR). Radioresistance and radiosensitivity were also observed in HNSCC cells that are MUC1 overexpression and MUC1 downexpression. This enhanced resistance to IR in MUC1-overexpressing cells is primarily due to increased the number of radiation-induced γH2AX/53BP1-positive foci and DNA double-strand break (DSB) repair kinetics. MUC1 overexpression repaired more than 90% of DSBs after 2 Gy radiation by 24 h compared to the empty vector overexpressing cells with less than 50% of DSB repair. However, MUC1 downexpression repaired less than 20% of DSBs compared to the empty vector-overexpresing cells. MUC1 overexpression inhibited proapoptotic protein expression, such as caspase-3, caspase-8, and caspase-9, and induced antiapoptotic protein Bcl-2, followed by resistance to IR-induced apoptosis. Our results showed that targeting MUC1 may be as a promising strategy to counteract radiation resistance of HNSCC cells.

Expression profile of MUC1 protein in Pigeon allergens positive asthmatic

BACKGROUND

Certain urban areas could contain many pigeon's allergens, which may play an imperative role in the exacerbation of asthma in pigeon allergen sensitive asthma patients. The circulating form of MUC1 in human serum has been considered as a biomarker for some allergic diseases. The study aimed to investigate the role of MUC1 in pigeon allergens positive asthma patients.

METHODS

We were enrolled 200 asthma patients including 81 males and 119 females. After positive pigeon exposure history, 108 patients underwent SPT testing against pigeon allergens (dropping and feather). A total of 17 patients, who had exposure history with SPT positive were undergone detail clinical examination. Serum MUC1expression analysis was done by western blotting method.

RESULTS

Out of 200 asthmatic patients, 108 (54%) patients had a history of exposure to pigeons. Skin prick test against pigeon (feather & dropping) allergens was positive in 17 (15.7%) patients among exposure asthmatics. The mean age of the study population was 28.8 ± 10.4 years with 9 males and 8 females. Baseline airway obstruction was seen in 58.8% cases. Out of 17 pigeons expose and sensitive asthmatic the MUC1 expression was up-regulated in 15 (88.2%) and down-regulated in 2 (11.8%). The mean value MUC1 fold change of 15 patients with up-regulation was 4.63 ± 3.00 fold.

CONCLUSION

MUC1 expression was up-regulated in 88.2% of patients, who were exposed and sensitive to pigeon allergen (dropping and feather). MUC1 may consider as a biomarker in pigeon sensitive asthma patients.

The Effect of Antioxidant Agents on Cisplatin-Induced Laryngeal Histological Alterations in Rats

The larynx-related adverse effects that depend on cisplatin decrease patient comfort and many antioxidants have been used to eliminate these side effects. We aimed to identify the laryngeal mucosal changes imposed by cisplatin and investigated whether antioxidants, and their healing effects on these changes, may help reduce laryngeal complications in patients resulting from adverse effects in the larynx. A rat model was designed to evaluate the effects of cisplatin on the larynx and the protective role of antioxidants. Single-dose cisplatin was given both intraperitoneally alone and additionally administered with p-coumaric acid, melatonin, resveratrol, vitamin D, and oleic acid over 5 days. Whole larynges were dissected and evaluated histologically, histochemically, and immunohistochemically. Varying degrees of mucosal changes cisplatin group, but neither erosion nor an ulcer was observed. Numerous variable histological effects of antioxidants were observed on cisplatin exposed laryngeal mucosa. The most obvious effects of cisplatin were edema. The results of the study showed that resveratrol was the most preventive antioxidant agent against cisplatin-dependent mucosal changes. The highest increase in the Ki67 index was in the oleic acid group. Vitamin D increased stromal cyclooxygenase-2 expression that may have an effect on increasing mucosal damage.

Gel-forming mucin interactome drives mucus viscoelasticity

Mucus is a hydrogel that constitutes the first innate defense in all mammals. The main organic component of mucus, gel-forming mucins, forms a complex network through both reversible and irreversible interactions that drive mucus gel formation. Significant advances in the understanding of irreversible gel-forming mucins assembly have been made using recombinant protein approaches. However, little is known about the reversible interactions that may finely modulate mucus viscoelasticity, which can be characterized using rheology. This approach can be used to investigate both the nature of gel-forming mucins interactions and factors that influence hydrogel formation. This knowledge is directly relevant to the development of new drugs to modulate mucus viscoelasticity and to restore normal mucus functions in diseases such as in cystic fibrosis. The aim of the present review is to summarize the current knowledge about the relationship between the mucus protein matrix and its functions, with emphasis on mucus viscoelasticity.

MUC1: The First Respiratory Mucin with an Anti-Inflammatory Function

MUC1 is a membrane-bound mucin expressed on the apical surfaces of most mucosal epithelial cells. In normal lung epithelia, MUC1 is a binding site for Pseudomonas aeruginosa, an opportunistic human pathogen of great clinical importance. It has now been established that MUC1 also serves an anti-inflammatory role in the airways that is initiated late in the course of a bacterial infection and is mediated through inhibition of Toll-like receptor (TLR) signaling. MUC1 expression was initially shown to interfere with TLR5 signaling in response to P. aeruginosa flagellin, but has since been extended to other TLRs. These new findings point to an immunomodulatory role for MUC1 during P. aeruginosa lung infection, particularly during the resolution phase of inflammation. This review briefly summarizes the recent characterization of MUC1’s anti-inflammatory properties in both the respiratory tract and extrapulmonary tissues.

Expression Of Mucin Gene Products in Laryngeal Squamous Cancer

OBJECTIVE: Mucins are high-molecular-weight glycoproteins present at the outer surface of mammalian cells. The objective of this study was to examine the expression of mucin (MUC) genes 3, 4, 5AC, 5B, 6, and 7 in early and late laryngeal squamous cancer using the in situ hybridization technique.

STUDY DESIGN: Retrospective analysis of pathological archive specimens.

RESULTS: While MUC 3 and 7 are expressed in a small proportion of early cancers, MUC 5AC, 5B, and 6 are not expressed in laryngeal squamous cancer. MUC 4 was expressed in 13 of the 30 patients. Ten patients and 3 patients with stage 1 and stage 4 disease respectively expressed MUC 4 gene (Fisher's exact, P = 0.02). MUC 4-positive patients had a definite trend towards better survival (log rank test, P = 0.05). In the presence of tumor stage and comorbidity grade, Cox's proportional hazards model failed to statistically confirm the survival advantage provided by MUC 4 gene expression.

CONCLUSION: There is a survival advantage for patients with advanced-stage nonmetastatic cancer when the MUC 4 gene is expressed.AIMS: To study the expression of mucin (MUC) genes 3, 4, 5AC, 5B, 6, and 7 in early and advanced squamous cell cancer of the larynx; to attempt to correlate changes in gene expression with tumor stage by studying stage I and stage IV (AJCC, 1988) tumors.

Biomarkers and laryngopharyngeal reflux

Laryngopharyngeal reflux is a controversial but increasingly made diagnosis used in patients with a collection of often non-specific laryngeal symptoms. It is a clinical diagnosis, and its pathophysiology is currently poorly understood. Previous reflux research has focused on injurious agents, acid, pepsin and biomarker expression. Failure of intrinsic defences in the larynx may cause changes in laryngeal epithelia, particularly alterations in carbonic anhydrases and E-cadherin. Carbonic anhydrase III levels vary in the larynx in response to laryngopharyngeal reflux, depending on location. Expression of E-cadherin, a known tumour suppressor, is reduced in the presence of reflux. Mucin expression also varies according to the severity of reflux. Further research is required to define the clinical entity of laryngopharyngeal reflux, and to identify a definitive mechanism for mucosal injury. Understanding this mechanism should allow the development of a comprehensive model, which would enable future diagnostic and therapeutic interventions to be developed.

Mucin Gene Expression in Human Laryngeal Epithelia: Effect of Laryngopharyngeal Reflux

Objectives:

We sought to document the mucin gene profile in normal human laryngeal epithelium and compare it with that in patients with reflux-attributed laryngeal injury or disease. We also investigated the effect of low pH with or without pepsin on mucin messenger RNA levels in vitro.

Methods:

Laryngeal biopsy specimens were obtained from 3 patients with clinically diagnosed laryngopharyngeal reflux and from 2 control subjects who had no signs or symptoms of reflux. Signs and symptoms were assessed by the Reflux Finding Score and the Reflux Symptom Index, respectively. Reverse transcription–polymerase chain reaction (RT-PCR) was performed to establish the mucin gene profile. Human hypopharyngeal epithelial cells were exposed to pH 7, 5, 4, and 2 with and without pepsin (0.1 mg/mL) for 20 minutes at 37°C, and expression of selected mucins was analyzed via real-time RT-PCR.

Results:

Mucin 1–5, 7, 9, 13, 15, 16, and 18–20 transcripts were detected in normal laryngeal epithelium, whereas mucin 6, 8, and 17 transcripts were not. Mucins 2, 3, and 5 were expressed at reduced levels in patients with reflux-attributed laryngeal injury or disease. These mucin genes were up-regulated after exposure to low pH in vitro (p < 0.005). Pepsin inhibited this up-regulation (p < 0.001).

Conclusions:

Reflux laryngitis is associated with down-regulation of mucin gene expression.

Distribution of mucins and antimicrobial substances lysozyme and lactoferrin in the laryngeal subglottic region

The subglottic region of the larynx is of high clinical relevance with regard to infections and malignancies. Little is known about the distribution of mucins and antimicrobial substances in this area. In this study, we have investigated the mucin distribution in the normal subglottis of the larynx. Moreover, we analysed the expression of lysozyme and lactoferrin in this area. Therefore, the subglottic region of 34 larynges was investigated immunohistochemically with different antibodies to mucins and antimicrobial substances. The epithelium reacted positive with antibodies to mucins MUC1 (34/34), 5AC (26/34), 5B (10/34), 7 (8/34), 8 (10/34) and 16 (19/34); submucosal glands were positive to mucins MUC1 (34/34), 5B (10/34), 7 (8/34), and 16 (19/34); high columnar epithelial cells and serous parts of subepithelial seromucous glands were also positive for lysozyme (34/34) and lactoferrin (34/34). The results show that human subglottic epithelium and subepithelial submucosal glands produce a broad spectrum of mucins that is almost comparable with that in other areas of the respiratory tract. We hypothesize that the mucin diversity of the subglottis has an impact on positive functional consequences during vocal production and antimicrobial defence. This antimicrobial defence is supported by synthesis and secretion of antimicrobial substances such as lysozyme and lactoferrin. Moreover, knowledge of the observed distribution pattern of mucins in the subglottis can be a useful tool for a classification of subglottic laryngeal carcinomas.

Influence of sialic acid removal on MUC1 antigenic reactivity in head and neck carcinoma

To investigate the influence of sialic acid removal on MUC1 peptidic and carbohydrate epitope reactivity in head and neck squamous cell carcinoma (HNSCC), tumor samples belonging to 24 HNSCC patients were studied by standard immunohistochemistry (IHC) with and without desialylation with 0.1 U/ml neuraminidase. From each tumor sample, subcellular fractions were obtained and analyzed by SDS-PAGE and Western blotting (WB). Three monoclonal antibodies (MAbs) were used: C595 MAb directed to MUC1 protein core, an anti-Tn hapten MAb, and an anti-sTn hapten MAb; a comparative analysis between desialylated and sialylated samples was performed. By IHC without neuraminidase treatment, 19 of 24 samples reacted with anti-MUC1 peptidic epitope, while Tn hapten was not detected and sTn was found in 1 of 24 cases. Desialylation increased either the number of reacting cells or the intensity of the reaction with C595 and anti-Tn MAbs, and some negative samples became positive. On the other hand, sTn expression decreased with desialylation. By WB, several bands from >200 to 25 kDa were found; desialylation increased high-molecular-weight bands, diminishing the detection of low-molecular-weight ones. The use of desialylation is a suitable treatment that contributes to the exposure of MUC1-associated epitopes, which may be related to the spreading of HNSCC.

Biodegradable nanoparticle mediated antigen delivery to human cord blood derived dendritic cells for induction of primary T cell responses

Dendritic cells (DCs) in the peripheral tissues act as sentinels of the immune system. They detect and capture pathogens entering the body and present their antigens to T cells to trigger responses directed towards elimination of the pathogen. The induction of peripheral tolerance against self and certain foreign antigens is also believed to be mediated through DCs. The outcome of any immune response is largely controlled by the microenvironment of antigen capture, processing and presentation by DCs. The "context" of antigen delivery to DCs will directly influence the microenvironment of antigen presentation and hence the regulation of immune responses. We report here preliminary investigations describing the formulation of a pharmaceutically acceptable, biodegradable, and strategic nanoparticulate delivery system, and its application for efficient antigen loading of DCs to achieve antigen specific T cell activation. "Pathogen-mimicking" nanoparticles capable of interacting with DCs were fabricated by incorporating monophosphoryl lipid A (MPLA; toll-like receptor (TLR) 4 ligand) or CpG ODN (seq #2006; TLR9 ligand) in biodegradable copolymer, poly(D,L,-lactic-co-glycolic acid) (PLGA). The uptake of PLGA nanoparticles by human umbilical cord blood derived DCs (DCs propagated from CD34 progenitors) was conclusively demonstrated by scanning electron microscopy (SEM), fluorescence activated cell sorting (FACS) and confocal laser scanning microscopy (CLSM). Cell phenotype at day 12 of cultures was determined as immature DC using specific cell surface markers, i.e. CD11c (approximately 90%), MHC-II (approximately 70%), CD86 (approximately 20%), CD83 (approximately 5%), CD80 (approximately 40%), CD40 (approximately 40%), and CCR7 (approximately 5%). Tetanus toxoid (TT), a model antigen, was encapsulated in nanoparticles along with an immunomodulator, i.e. either MPLA or CpG ODN. DCs pulsed with various antigen formulations were co-cultured with autologous naïve T cells at various cell ratios (DC: T cells were 1:5-20). The DCs pulsed with TT and MPLA together in nanoparticles induced significantly higher T cell proliferation (P<0.05) as compared to when DCs pulsed with TT and MPLA in solution were employed. A similar trend was observed when CpG ODN was used instead of MPLA in the TT nanoparticles. This strategy of antigen delivery to DCs was then tested with a cancer vaccine candidate, a MUC1 lipopeptide. The T cell proliferation observed in the presence of nanoparticulate MUC1 and MPLA pulsed-DCs was much higher than DCs pulsed with soluble antigen (P<0.0005). These results indicate that PLGA nanoparticles mimicking certain features of pathogens are efficient delivery systems for targeting vaccine antigens to DCs and activation of potent T cell responses.

MUC1 mucin and carbohydrate associated antigens as tumor markers in head and neck squamous cell carcinoma

An immunological analysis to study MUC1 mucin core protein and carbohydrate associated antigens as tissue tumor markers in head and neck carcinoma was performed. Twenty nine patients with the following tumor localizations were included: tongue (n=10), larynx (n=8), oral cavity (n=4), maxillary sinus (n=3), tonsillar ring (n=3) and pharynx (n=1); seven samples of epithelium obtained from normal organs at the same localizations were studied as controls. Immunohistochemical analysis was performed following standard procedures and reaction was graded according to staining intensity and distribution. From each tissue section, membrane, cytoplasmic and nuclear moieties were obtained by differential centrifugation with subsequent fractionation by density gradient centrifugation (6M guanidium chloride-CsCl); subcellular moieties and CsCl derived fractions were analyzed by immunoblotting. Monoclonal antibodies (MAbs) reacting with the core protein of MUCI (C595) and associated carbohydrate antigens were: Tn, 83D4 MAb; Lewis y antigen (Le y), C14 MAb; Lewis x antigen (Le x), KM380 MAb and sialyl Lewis x (sLe x), KM93 MAb. Statistical analysis was undertaken by Spearman rank correlation. In tumor samples, the immunohistochemical identification of MUCl core protein and associated antigens was extended; differences were found in the pattern and intensity of expression; results were corroborated by immunoblotting although in a few samples there was not coincidence between both methods. Localization, tumor mass or node involvement did not show significant differences for any of the antigens studied.

CONCLUSIONS

1) head and neck carcinoma expressed MUCI and associated carbohydrate antigens in high levels; 2) no relationship between antigenic expression and tumor status was found.