Squamous Cell Carcinoma Samples Research Articles

Direct specimen collection during routine operation improves nucleic acid quality in genetic analysis samples for head and neck tumors: A retrospective study

The nucleic acid integrity of head and neck squamous cell carcinoma (HNSCC) samples is poor, and the material available for genetic analysis is limited. Therefore, to expand the effectiveness of personalized medicine in patients with HNSCC, a new sampling method is needed. In total, 128 samples from 44 patients with HNSCC were studied: 32 genetic analysis samples (GASs) collected as 5 × 5 × 5 mm tissue fragments from resected large tumors and immediately embedded in a small formalin bottle within 10 min (i.e., the ischemic time), 43 primary tumor components (primary), 14 decalcified tumor (DC) samples, 32 metastatic tumors in lymph nodes (LNs), and 7 parakeratinized components (PKCs). The nucleic acid quality in the GAS, primary, DC, LN, and PKC groups was compared and next-generation sequencing (NGS) was performed. DNA integrity number and percentage of RNA fragments with > 200 nucleotides were significantly higher in the GAS group than those in the other groups. RNA integrity number decreased first in LN, followed by GAS, primary, and DC. No significant differences were observed in DIN, RIN and DV200 among the PKC, primary and LN. Following methyl green-pyronin staining, preserved DNA and RNA were not visualized in DC samples. Most NGS metrics did not differ significantly among primary, LN, and PKC samples. In conclusion, GASs should be collected during routine hospital activities. When the volume of viable materials is limited, PKCs should be considered for genetic analysis.

Autophagy indicators in oral squamous cell carcinoma

Autophagy plays an important role in maintaining cellular homeostasis. Dysregulation of autophagy has been linked to a number of diseases, including cancer. We retrospectively evaluated immunohistochemical expression of the autophagy markers LC3B and p62 and the autophagy regulator mTOR as an indicator of autophagy in 100 surgically resected primary oral squamous cell carcinoma (OSCC) samples and sought associations with various clinicopathological factors. The expression of all three proteins was significantly higher in malignant squamous cells than in benign squamous cells in the free mucosal margin adjacent to the OSCC. Male sex, higher tumour (T) stage, node (N) stage and tumour, node, metastasis (TNM) stage were significantly associated with high marker expression; age and histological grade showed no significant association. LC3B, p62 and mTOR expression were positively correlated with one another in OSCCs, and the correlation was significant for LC3B and mTOR as well as for LC3B and p62. Disease-free survival showed an inverse correlation with high mTOR expression. Our data suggest that autophagy inhibitors and mTOR inhibitors may have a therapeutic role in the treatment of OSCCs.

HPV38 impairs UV-induced transcriptional activation of the IL-18 pro-inflammatory cytokine.

Here, we demonstrate that the direct binding of p53 on the IL-18 promoter region regulates its gene expression. However, the presence of E6 and E7 from human papillomavirus type 38 impairs this mechanism via a new inhibitory complex formed by DNA methyltransferase 1 (DNMT1)/PKR/ΔNp73α, which binds to the region formerly occupied by p53 in primary keratinocytes.

Dedifferentiated Schwann cells promote perineural invasion mediated by the PACAP paracrine signalling in cervical cancer.

Perineural invasion (PNI) has emerged as a key pathological feature and be considered as a poor prognostic factor in cervical cancer. However, the underlying molecular mechanisms are largely unknown. Here, PNI status of 269 cervical squamous cell carcinoma and endocervical adenocarcinoma (CESC) samples were quantified by using whole-slide diagnostic images obtained from The Cancer Genome Atlas. Integrated analyses revealed that PNI was an indicative marker of poorer disease-free survival for CESC patients. Among the differentially expressed genes, ADCYAP1 were identified. Clinical specimens supported that high expression of PACAP (encoded by ADCYAP1) contributed to PNI in CESC. Mechanistically, PACAP, secreted from cervical cancer cells, reversed myelin differentiation of Schwann cells (SCs). Then, dedifferentiated SCs promoted PNI by producing chemokine FGF17 and by degrading extracellular matrix through secretion of Cathepsin S and MMP-12. In conclusion, this study identified PACAP was associated with PNI in cervical cancer and suggested that tumour-derived PACAP reversed myelin differentiation of SCs to aid PNI.

Hsa-miR-26a-5p improves OSCC sensitivity to ferroptosis by inhibiting SLC7A11

ObjectiveSLC7A11 plays a crucial role in ferroptosis and is upregulated in oral squamous cell carcinoma (OSCC) samples. This study mainly aimed to elucidate the association of SLC7A11 with ferroptosis in OSCC and analyze its upstream regulatory mechanism. DesignThe expression of SLC7A11 in OSCC and paracancerous tissues was detected. After administration of different concentrations of erastin to OSCC cells, cell viability was examined by MTT, and changes in GSH, MDA and Fe2+ concentrations were determined. Then, mitochondrial changes were examined by transmission electron microscopy. Bioinformatics analysis was performed to predict the upstream regulatory miRNA of SLC7A11, and the interaction between miR-26a and SLC7A11 was confirmed by a dual luciferase reporter gene. The effect of miR-26a mimics on ferroptosis resistance was also examined. ResultsSLC7A11 expression was upregulated in both OSCC patients and cells, with high SLC7A11 expression levels in SCC-9 cells with an IC50 = 69.75 μM for erastin and low SLC7A11 expression levels in SCC-4 cells with an IC50 = 8.463 μM for erastin. SCC-9 exhibited a higher level of ferroptosis resistance than SCC-4. miR-26a-5p expression was downregulated in both OSCC patients and cells. A dual luciferase reporter assay confirmed that miR-26a-5p targets binding to the SLC7A11 3′UTR. Transfection of the miR-26a mimic significantly inhibited the viability of OSCC cells and promoted erastin-induced cellular ferroptosis. Transfection of miR-26a inhibitor gave the opposite result. Overexpression of SLC7A11 significantly reversed miR-26a mimic ferroptosis induction. ConclusionmiR-26a-5p can exert OSCC inhibitory effects by regulating SLC7A11 and promote ferroptosis in OSCC cells by inhibiting SLC7A11.

Application of Protein-Protein Interaction Network Analysis in Order to Identify Cervical Cancer miRNA and mRNA Biomarkers.

Cervical cancer (CC) is one of the world's most common and severe cancers. This cancer includes two histological types: squamous cell carcinoma (SCC) and adenocarcinoma (ADC). The current study aims at identifying novel potential candidate mRNA and miRNA biomarkers for SCC based on a protein-protein interaction (PPI) and miRNA-mRNA network analysis. The current project utilized a transcriptome profile for normal and SCC samples. First, the PPI network was constructed for the 1335 DEGs, and then, a significant gene module was extracted from the PPI network. Next, a list of miRNAs targeting module's genes was collected from the experimentally validated databases, and a miRNA-mRNA regulatory network was formed. After network analysis, four driver genes were selected from the module's genes including MCM2, MCM10, POLA1, and TONSL and introduced as potential candidate biomarkers for SCC. In addition, two hub miRNAs, including miR-193b-3p and miR-615-3p, were selected from the miRNA-mRNA regulatory network and reported as possible candidate biomarkers. In summary, six potential candidate RNA-based biomarkers consist of four genes containing MCM2, MCM10, POLA1, and TONSL, and two miRNAs containing miR-193b-3p and miR-615-3p are opposed as potential candidate biomarkers for CC.

The Study of Expression of Hypoxia-Inducible Factor-1 Alpha (HIF-1 Alpha) and Hypoxia-Inducible Factor-2 Alpha (HIF-2 Alpha) in Oral Squamous Cell Carcinoma: An Immunohistochemical Study.

Oral cancer is the major cause of mortality and morbidity worldwide. There are many factors that influence the tumor microenvironment that promotes tumorigenesis. Hypoxia is one of the factors that affects the process of angiogenesis by inducing proangiogenic factors to maintain the blood supply which in turn enhances the aggressiveness of the tumor and prognosis of solid tumors such as oral squamous cell carcinoma. The aim of the study was to compare the expression of hypoxia-inducible factor 1α (HIF-1α) and hypoxia-inducible factor 2α (HIF-2α) in various histological grades of oral squamous cell carcinoma immunohistochemically. Immunohistochemical evaluation of HIF-1α and HIF-2α was done in 90 samples of oral squamous cell carcinoma which were graded histologically into 30 samples each of well, moderately and poorly differentiated squamous cell carcinoma. Statistical evaluation: Statistical analysis was doneto study the prognostic significance of the biomarkers. All the cases showed positivity for expression of HIF-1α and HIF-2α. The number of positive staining in both markers reduced as the tumor severity increased from well to poorly differentiated. The expression of MIL of HIF-2αwas higher than HIF 1α and HIF 2α expression was mostly seen in cytoplasmic in well-differentiated and nuclear in both moderately and poorly differentiated OSCC suggestive that HIF-2α is a more specific marker to hypoxia. Hypoxia is an essential factor that triggers other angiogenic switch and inflammatory factors which facilitates the process of tumorigenesis. This is also important for predicting the treatment outcome and prognosis of the patients. HIF-2α is a more sensitive marker that appears to be correlated and could perhaps serve as a good surrogate marker of hypoxia.

The Prognostic Significance of KIAA1522 Expression in Non-Small-Cell Lung Cancer Patients.

The majority of lung cancers belong to the non-small-cell lung cancer (NSCLC) category, which is linked to a high mortality rate despite significant progress in diagnosis and treatment. Therefore, there is a need for novel prognostic NSCLC biomarkers to improve prognosis which currently remains poor. Recent studies and analyses of gene expression data of NSCLC revealed that high expression of KIAA1522 was significantly associated with poor prognosis and decreased overall survival. We identified 98 patients who underwent radical curative surgical resections or metastasectomy for pulmonary adenocarcinoma and squamous cell carcinoma at our institution or the pathological diagnosis confirmed by our pathologists. Following the latest data, we utilized immunohistochemistry to assess the expression of KIAA1522 and investigated its association with various clinic-demographic parameters, pathological stages, recurrence rates, overall survival, and disease-free survival in patients who achieved complete remission. Notably, there were no significant differences in the expression profiles of KIAA1522 between adenocarcinoma and squamous cell carcinoma samples (p=0.6). Survival analysis was conducted using log-rank tests and a multivariate Cox proportional hazard model. Of the 98 samples, 54 (55.1%) exhibited high expression of KIAA1522, and patients with high KIAA1522 expression had a significantly shorter overall survival than the low-expression group (p=0.01). Multivariate Cox proportional hazard models in which metastatic patients were included revealed that along with older age, higher TNM stage (tumor, node, metastasis system), and Eastern Cooperative Oncology Group (ECOG) performance status, high expression of KIAA1522 served as an independent prognostic factor. A high expression profile was not significantly associated with relapses in those whose complete remission had been achieved. Still, those patients with high expression of KIAA1522 tended to exhibit a shorter disease-free survival rate. In conclusion, our findings suggest that KIAA1522 expression is an independent factor for predicting overall survival and may serve as a valuable prognostic indicator for relapse and disease-free survival in NSCLC patients.

Identification of salivary metabolic biomarker signatures for oral tongue squamous cell carcinoma

ObjectiveTo identify the salivary metabolites associated with squamous cell carcinoma of the tongue to develop easy and non-invasive potential biomarkers for disease diagnosis. DesignInitially, the study utilized untargeted metabolomics to analyze 20 samples of tongue squamous cell carcinoma and 10 control samples. The objective was to determine the salivary metabolites that exhibited differential expression in tongue squamous cell carcinoma. Then the selected metabolites were validated using targeted metabolomics in saliva samples of 100 patients diagnosed with squamous cell carcinoma of the tongue, as well as 30 healthy control individuals. ResultsFrom the analysis of untargeted metabolomics, 10 metabolites were selected as potential biomarkers. In the subsequent targeted metabolomics study on these selected metabolites, it was observed that N-Acetyl-D-glucosamine, L-Pipecolic acid, L-Carnitine, Phosphorylcholine, and Deoxyguanosine exhibited significant differences. The receiver operating characteristic curve analysis indicates a combination of three important metabolites such as N-Acetyl-D-glucosamine, L-Pipecolic acid and L-Carnitine provided the best prediction with an area under the curve of 0.901. ConclusionsThe present result reveals that the N-Acetyl-D-glucosamine, L-Pipecolic acid and L-Carnitine are the signature diagnostic biomarkers for oral tongue squamous cell carcinoma. These findings can be used to develop a rapid and non-invasive method for disease monitoring and prognosis in oral tongue cancer.

Immunosuppressive effect of small extracellular vesicle PD-L1 is restricted by co-expression of CD80.

The PD-L1 on tumor cell-derived small extracellular vesicles (sEVs) can suppress the proliferation and cytokine production of T cells. However, PD-L1 can also be expressed by non-tumor cells. The present study is designed to test whether immunocytes release immunosuppressive PD-L1-positive sEVs. sEVs were isolated from different clinical samples of head and neck squamous cell carcinoma (HNSCC) patients, the level and cellular origins of PD-L1-positive sEVs were assessed. Co-expression of CD80 on PD-L1-positive sEVs was examined to evaluate the immunosuppressive and tumor-promotive effects. PD-L1-positive sEVs in HNSCC patients had various cellular origins, including tumor cell, T cell, B cell, dendritic cell and monocyte/macrophage. However, PD-L1-positive sEVs derived from immune cells did not exert immunosuppressive functions due to the co-expression of CD80. It was verified that co-expression of CD80 disrupted the binding of sEV PD-L1 to its receptor PD-1 on T cells and attenuated the immunosuppression mediated by sEV PD-L1 both in vitro and in vivo. The study suggests that PD-L1-positive sEVs have the cellular origin and functional heterogeneity. Co-expression of CD80 could restrict the immunosuppressive effect of sEV PD-L1. A greater understanding of PD-L1-positive sEV subsets is required to further improve their clinical application.

Small patient datasets reveal genetic drivers of non-small cell lung cancer subtypes using machine learning for hypothesis generation

Aim: Many small datasets of significant value exist in the medical space that are being underutilized. Due to the heterogeneity of complex disorders found in oncology, systems capable of discovering patient subpopulations while elucidating etiologies are of great value as they can indicate leads for innovative drug discovery and development. Methods: Two small non-small cell lung cancer (NSCLC) datasets (GSE18842 and GSE10245) consisting of 58 samples of adenocarcinoma (ADC) and 45 samples of squamous cell carcinoma (SCC) were used in a machine intelligence framework to identify genetic biomarkers differentiating these two subtypes. Utilizing a set of standard machine learning (ML) methods, subpopulations of ADC and SCC were uncovered while simultaneously extracting which genes, in combination, were significantly involved in defining the subpopulations. A previously described interactive hypothesis-generating method designed to work with ML methods was employed to provide an alternative way of extracting the most important combination of variables to construct a new data set. Results: Several genes were uncovered that were previously implicated by other methods. This framework accurately discovered known subpopulations, such as genetic drivers associated with differing levels of aggressiveness within the SCC and ADC subtypes. Furthermore, phyosphatidylinositol glycan anchor biosynthesis, class X (PIGX) was a novel gene implicated in this study that warrants further investigation due to its role in breast cancer proliferation. Conclusions: The ability to learn from small datasets was highlighted and revealed well-established properties of NSCLC. This showcases the utility of ML techniques to reveal potential genes of interest, even from small datasets, shedding light on novel driving factors behind subpopulations of patients.

Effectiveness of deep learning classifiers in histopathological diagnosis of oral squamous cell carcinoma by pathologists

The study aims to identify histological classifiers from histopathological images of oral squamous cell carcinoma using convolutional neural network (CNN) deep learning models and shows how the results can improve diagnosis. Histopathological samples of oral squamous cell carcinoma were prepared by oral pathologists. Images were divided into tiles on a virtual slide, and labels (squamous cell carcinoma, normal, and others) were applied. VGG16 and ResNet50 with the optimizers stochastic gradient descent with momentum and spectral angle mapper (SAM) were used, with and without a learning rate scheduler. The conditions for achieving good CNN performances were identified by examining performance metrics. We used ROCAUC to statistically evaluate diagnostic performance improvement of six oral pathologists using the results from the selected CNN model for assisted diagnosis. VGG16 with SAM showed the best performance, with accuracy = 0.8622 and AUC = 0.9602. The diagnostic performances of the oral pathologists statistically significantly improved when the diagnostic results of the deep learning model were used as supplementary diagnoses (p-value = 0.031). By considering the learning results of deep learning model classifiers, the diagnostic accuracy of pathologists can be improved. This study contributes to the application of highly reliable deep learning models for oral pathological diagnosis.

MicroRNA Expression Profile Separates Squamous Cell Carcinoma by Mode of Differentiation.

Squamous cell carcinoma (SCC) is a non-melanoma skin cancer with several risk factors including age and sun exposure. The degree of histological differentiation is considered an independent predictor of recurrence, metastasis, and survival. MicroRNAs (miRNAs) are small non-coding RNAs that play an important role in regulating gene expression, culminating in the initiation and progression of multiple tumors. The aim of this study was to determine changes in miRNA expression as a result of the mode of differentiation in SCC. We analyzed 29 SCC samples that were separated by mode of differentiation into well (n=4), moderate (n=20) and poor (n=5). Of the 29 samples, five had matched normal tissues, which were used as controls. Total RNA was extracted using the RNeasy FFPE kit, and miRNAs were quantified using Qiagen MiRCURY LNA miRNA PCR Assays. Ten miRNAs (hsa-miR-21, hsa-miR-146b-3p, hsa-miR-155-5p, hsa-miR-451a, hsa-miR-196-5p, hsa-miR-221-5p, hsa-miR-375, hsa-miR-205-5p, hsa-let-7d-5p and hsa-miR-491-5p) that have been previously differentiated in cancer, were quantified. A fold regulation above 1 indicated upregulation and below 1, downregulation. Hierarchical clustering showed that the miRNA expression profile in the moderately differentiated group was similar to the well-differentiated group. The miRNA with the greatest upregulation in the moderate group was hsa-miR-375, while in the well group, hsa-miR-491-5p showed the greatest downregulation. In conclusion, this study observed that the well and moderate groups had similar microRNA expression patterns compared to the poorly differentiated group. MicroRNA expression profiling may be used to better understand the factors underpinning mode of differentiation in SCC.

Programmed death-ligand 1 (PD-L1) expression in cervical intraepithelial neoplasia and cervical squamous cell carcinoma of HIV-infected and non-infected patients

Programmed death-ligand 1 (PD-L1) is overexpressed in cervical carcinoma, hindering tumor destruction. The aim of this study was to assess PD-L1 expression by immunohistochemistry in cervical squamous cell carcinoma (SCC) and squamous intraepithelial lesions (SILs) from human immunodeficiency virus–positive (HIV+) and human immunodeficiency virus-negative (HIV-) patients. A total of 166 SCC and SIL samples of HIV+ and HIV- patients were included and analyzed for PD-L1 expression through tumor proportion score (TPS), and results were stratified in five TPS groups using SP263 antibody and, combined positive score (CPS) using 22C3 antibody. In cohort 1 (SP263 clone), all HIV+ patients were negative for intraepithelial lesion or malignancy (NILM), and low-grade squamous intraepithelial lesions (LSILs) scored < 1; and 87.5% of high-grade squamous intraepithelial lesions (HSILs) adjacent to SCC, 19% of HSILs non-adjacent to SCC, and 69% of SCCs scored ≥ 1 (15.4% scored 5). In HIV- patients, all NILM, LSILs, HSILs adjacent to SCC, and two HSILs non-adjacent to SCC scored < 1. SCC: 88.2% scored ≥ 1 and 5.9% scored 5. In cohort 2 (SP263 and 22C3 clones), 16.7% of HIV+ patients with SCC were positive with both clones, CPS ≥ 1 (22C3) or score 5 (≥ 50%) (SP263), showing no significant differences in positivity between both clones. These results indicate that a relatively low percentage of SCCs (16.7%; both in HIV+ and in HIV- patients) express PD-L1 (TPS ≥ 50% and CPS > 1), which may be due to some samples being archival material, sample characteristics, or use of different methodologies, highlighting the need for standardization of PD-L1 assessment in SCC of the cervix. The fact that PD-L1 is overexpressed in SILs of HIV+ patients suggests potential additional applications for immunotherapy in this disease.

Downregulation of ITGA5 inhibits lymphangiogenesis and cell migration and invasion in male laryngeal squamous cell carcinoma.

ITGA5, a fibronectin receptor was highly expressed in laryngeal squamous cell carcinoma (LSCC) samples and was related to poor survival. However, the potential mechanism remains unclear. To elucidate the regulatory role of ITGA5 in LSCC progression, we investigated the effect of ITGA5 expression on lymphangiogenesis, migration, and invasion of LSCC cells in vitro and in vivo using immunohistochemistry, siRNA transfection, qRT-PCR, western blotting, enzyme-linked immunosorbent assay, flow cytometry, transwell co-culture, tube formation, cell migration, and invasion assays, and a subcutaneous graft tumor model. The expression of ITGA5 was higher in the LSCC tissues and linked to lymph node metastasis and T staging. Moreover, ITGA5 expression was significantly positively correlated with VEGF-C expression, and the lymphatic vessel density of patients with high ITGA5 expression was noticeably higher than that of patients with low ITGA5 expression. Additionally, it was found in vitro that downregulation of ITGA5 expression not only inhibited the expression and secretion of VEGF-C, but also suppressed the tube-forming ability of human lymphatic endothelial cells (HLECs) and the migration and invasion ability of LSCC cells, while exogenous VEGF-C supplementation reversed these phenomena. Furthermore, a tumor xenograft assay showed that si-ITGA5 restrained the growth and metastasis of TU212-derived tumors in vivo. Our findings suggested that ITGA5 induces lymphangiogenesis and LSCC cell migration and invasion by enhancing VEGF-C expression and secretion.

Expression of Epsin3 and its interaction with Notch signalling in oral epithelial dysplasia and oral squamous cell carcinoma.

Most oral squamous cell carcinoma patients present with late-stage disease. Early detection of the disease is considered to be the most effective way of improving patient outcomes. Several biomarkers have been identified as indicators of oral cancer development and progression; however, none have been translated into clinical practice. In this study, we have investigated the role of Epsin3, an endocytic adaptor protein, and Notch1, a transmembrane signalling protein, in oral carcinogenesis with a view to explore their potential as biomarkers. Oral cancer cell lines and a normal oral keratinocyte cell line were used together with tissue samples of normal oral mucosa (n = 21), oral epithelial dysplasia (n = 74) and early stage (Stages I and II) oral squamous cell carcinoma (n = 31). Immunocytochemical staining, immunoblotting and real-time quantitative polymerase chain reaction (PCR) were performed to assess protein as well as gene expression levels. The expression levels of Epsin3 and Notch1 mRNA and protein are variable across different oral squamous cell carcinoma derived cell lines. Epsin3 was upregulated in oral epithelial dysplasia and oral squamous cell carcinoma tissues compared with normal epithelium. Overexpression of Epsin3 resulted in a significant reduction of Notch1 expression in oral squamous cell carcinoma. Notch1 was generally downregulated in the dysplasia and oral squamous cell carcinoma samples. Epsin3 is upregulated in oral epithelial dysplasia and oral squamous cell carcinoma and has the potential to be used as a biomarker for oral epithelial dysplasia. Notch signalling is downregulated in oral squamous cell carcinoma, possibly through an Epsin3-induced de-activation pathway.

Exosomes derived from oral squamous cell carcinoma tissue accelerate diabetic wound healing.

It is a widespread and difficult problem that refractory diabetic wounds have a poor local environment and prolonged inflammatory irritation. Tumor cell-derived exosomes play an important role in the development of tumors, as they can promote tumor cell proliferation, migration, and invasion and enhance tumor cell activity. However, tumor tissue-derived exosomes have been less studied, and it is unclear how they affect wound healing. In this study, we extracted tissue-derived exosomes from human oral squamous carcinoma and paracancerous tissue by ultracentrifugation, size exclusion chromatography and ultrafiltration and performed exosome characterization. In vitro, the oral squamous cell carcinoma tissue-derived exosomes (OSCC Ti-Exos) promoted the proliferation and migration of endothelial cells, keratinocytes, and fibroblasts. In addition, in vivo experiments showed that the OSCC Ti-Exos accelerated the healing of diabetic wounds and were safe in mice. In contrast, there was no promoting effect of paracancerous tissue-derived exosomes either in vivo or in vitro. In conclusion, OSCC Ti-Exos promoted the healing of diabetic wounds, demonstrated preliminary biosafety in mice and have promise as therapeutic applications.

Variations in protein expression associated with oral cancer.

Differential protein expression of the oral microbiome is related to human diseases, including cancer. In order to reveal the potential relationship between oral bacterial protein expression in oral squamous cell carcinoma (OSCC), we designed this study. We obtained samples of the same patient from cancer lesion and anatomically matched normal site. Then, we used the label free quantitative technique based on liquid chromatography tandem mass spectrometry (LC-MS/MS) to analyze the bacteria in the samples of oral squamous cell carcinoma at the protein level, so as to detect the functional proteins. Protein diversity in the cancer samples was significantly greater than in the normal samples. We identified a substantially higher number of the taxa than those detected in previous studies, demonstrating the presence of a remarkable number of proteins in the groups. In particular, proteins involved in energy production and conversion, proton transport, hydrogen transport and hydrogen ion transmembrane transport, ATP-binding cassette (ABC) transporter, PTS system, and L-serine dehydratase were enriched significantly in the experimental group. Moreover, some proteins associated with Actinomyces and Fusobacterium were highly associated with OSCC and provided a good diagnostic outcome. The present study revealed considerable changes in the expression of bacterial proteins in OSCC and enrich our understanding in this point.

Expression of heat shock protein 70 in oral epithelial dysplasia and squamous cell carcinoma.

Heat shock proteins (HSPs) are overexpressed in a variety of human malignancies. They are involved in tumor cell proliferation, differentiation, invasion, metastasis, death, and immune system detection. HSP 70 has been shown to resist cytotoxicity in cancer cells and even enhance tumor development through an immune escape mechanism, suggesting that HSP70 may play a role in carcinogenesis. The aim of our study was to evaluate the role of HSP70 as a predictive marker for malignant transformation in oral epithelial dysplasia. Thirty samples of epithelial dysplasia (10 mild dysplasia, 10 moderate dysplasia, and 10 severe dysplasia/carcinoma-in-situ cases), 10 samples of well-differentiated oral squamous cell carcinoma (OSCC), and 10 samples of normal oral mucosa were routinely processed, formalin-fixed, paraffin-embedded, and immunohistochemically examined for HSP70 expressions. To determine the statistical difference between two groups, a one-way analysis of variance (ANOVA) and the Mann-Whitney test were used. HSP70 expression was high but not homogenous in normal mucosa. Dysplasia showed an initial drop, and the expression increased with increasing degrees of dysplasia. There was no statistically significant difference across various types of epithelial dysplasia. From dysplasias to well-differentiated carcinoma, HSP70 exhibited a considerable rise. Overexpression of HSP70 in clinically suspicious and histologically established epithelial dysplasia may suggest a likelihood of transformation to well-differentiated OSCC and may have a prognostic value. However, more studies with a bigger sample size are needed to prove HSP70's role as a predictor.

Altered oral microbiome in Sudanese Toombak smokeless tobacco users carries a newly emerging risk of squamous cell carcinoma development and progression

There are an estimated 6–10 million smokeless tobacco (Toombak) users in Sudan, the majority being males. Toombak is known to be a carcinogenic product that is likely to modify the oral microbiome spatiality into a high-risk potential for the development and progression of oral cancer, but previous studies are lacking in this field. Here, we endeavour for the first time the exploration of the oral microbiome in key mucosal areas of the oral cavity and assess the microbiome variations in premalignant and oral squamous cell carcinoma (OSCC) samples from both users and non-users of Toombak. 16S rRNA sequencing was performed on DNA obtained from pooled saliva, oral mucosa and supragingival plaque from 78 Sudanese users and non-users of Toombak, aged between 20 and 70 years. In 32 of the pooled saliva samples, the mycobiome (fungal) environment was analysed through ITS sequencing. Then, 46 formalin-fixed paraffin-embedded samples of premalignant and OSCC samples were collected, and their associated microbiomes sequenced. The oral Sudanese microbiome was found to be enriched in Streptococcaceae, but Staphylococcaceae were significantly more abundant amongst Toombak users. Genera enriched in the oral cavity of Toombak users included Corynebacterium_1 and Cardiobacterium while in non-users, Prevotella, Lactobacillus and Bifidobacterium were prominent. Aspergillus was the most abundant fungus in the mouths of Toombak users with a marked loss of Candida. The genus Corynebacterium_1 was abundant in the buccal, floor of the mouth and saliva microbiomes as well as in oral cancer samples from Toombak users indicating a possible role for this genus in the early stages of oral cancer development. An oral cancer microbiome that favours poor survival and metastasis in those who use Toombak also emerged that includes the genera Stenotrophomonas and Schlegelella. Those utilising Toombak carry an altered oral microbiome that may be an additional risk factor for this products carcinogenicity to the oral structures. These significant microbiome modulations are a newly emerging key driving factor in oral cancer development and progression in Toombak users while it is also shown that Toombak users carry an oral cancer microbiome that may increase the potential for a poorer prognosis.