Protein-Protein Interaction Network Analysis of Salivary Proteomic Data in Oral Cancer Cases

Improving the Stability of Protein-Protein Interaction Assay FlimPIA Using a Thermostabilized Firefly Luciferase

The protein–protein interaction assay is a key technology in various fields, being applicable in drug screening as well as in diagnosis and inspection, wherein the stability of assays is important. In a previous study, we developed a unique protein–protein interaction assay “FlimPIA” based on the functional complementation of mutant firefly luciferases (Fluc). The catalytic step of Fluc was divided into two half steps: D-luciferin was adenylated in the first step, while adenylated luciferin was oxidized in the second step. We constructed two mutants of Fluc from Photinus pyralis (Ppy); one mutant named Donor is defective in the second half reaction, while the other mutant named Acceptor exhibited low activity in the first half reaction. To date, Ppy has been used in the system; however, its thermostability is low. In this study, to improve the stability of the system, we applied Fluc from thermostabilized Luciola lateralis to FlimPIA. We screened suitable mutants as probes for FlimPIA and obtained Acceptor and Donor candidates. We detected the interaction of FKBP12-FRB with FlimPIA using these candidates. Furthermore, after the incubation of the probes at 37°C for 1 h, the luminescence signal of the new system was 2.4-fold higher than that of the previous system, showing significant improvement in the stability of the assay.

Salivary melatonin in oral squamous cell carcinoma patients

Melatonin’s role in circadian rhythm is well documented, as are its’ anti-oxidant, oncostatic and anti-inflammatory properties. Poor sleep quality has been associated as a potential risk factor for several malignancies, including head and neck cancers. The purpose of this study is to determine salivary melatonin (MLT) levels in oral squamous cell carcinoma (OSCC) patients, compare the salivary MLT levels with those in healthy individuals and compare the salivary and serum levels in OSCC patients. Furthermore, the aim is to investigate the potential relationship between sleep quality and salivary MLT levels in OSCC patients. Unstimulated (UWS) and stimulated (SWS) whole saliva was sampled from patients with T1N0M0 and T2N0M0 OSCC (N = 34) and 33 sex and age matched healthy subjects. Serum samples were taken from 11 OSCC patients. Sleep quality was measured using Pittsburgh Sleep Quality Index (PSQI) questionnaire. Melatonin levels in UWS and SWS were significantly higher in the OSCC group. Sleep quality was significantly lower in patients with OSCC (P = 0.0001). ROC analysis was found to be significant (P < 0.001) in evaluating MLT concentration limit in diagnosing OSCC. The expected relationship between sleep quality and salivary MLT levels in OSCC patients was not observed. Our results suggest salivary MLT as a potential biomarker that might facilitate non-invasive detection of early stage OSCC.

Preoperative C-reactive protein to albumin ratio and oral health in oral squamous cell carcinoma patients

Background

The C-reactive protein to albumin (CRP/alb) ratio can predict early survival of a hospitalized patient. We evaluated factors that influence the preoperative CRP/alb ratio in oral squamous cell carcinoma (OSCC) patients and in particular clarified the role of oral health to this ratio.

Materials and methods

Data from surgically treated OSCC patients were collected retrospectively. The outcome variables were preoperative CRP/alb ratio, CRP level, and alb level. The studied predictors were total number of teeth, periodontal stability, marginal bone loss, tumour stage, T-class, lymph node status, and site. The statistical significance of age, sex, comorbidity combination of age and disease history (Charlson Comorbidity Index [CCI]), smoking, and alcohol history for outcome variables were evaluated. Patient 3-month mortality and occurrence of postoperative infections were recorded.

Results

A total of 159 patients were included in the study. The early mortality was 3.8%. CRP/alb was higher in these patients than in those who survived. The only independent variables for CRP/alb changes were CCI and heavy alcohol use. The CRP/alb ratio was significantly lower in non-heavy alcohol users (odds ratio [OR] 0.114, 95% confidence interval [CI] 0.024–0.541; adjusted p = 0.006) than in other patients. Patients with CCI 0–1 were more likely to have a lower CRP/alb ratio than patients with CCI ≥ 5 (OR 0.033, 95% CI 0.004–0.284; adjusted p = 0.002). In addition, high CRP/alb ratio associated with postoperative infections (p = 0.026).

Conclusions

The CRP/alb ratio was high in OSCC patients with combined comorbities of age and disease history and in patients with heavy alcohol use. Oral health or tumour-related variables did not independently affect the CRP/alb ratio. The CRP/alb ratio appears suitable for prediction of OSCC patient early survival.

The Challenges of OSCC Diagnosis: Salivary Cytokines as Potential Biomarkers

Fast, economic, and noninvasive, molecular analysis of saliva has the potential to become a diagnostic tool of reference for several local and systemic diseases, oral cancer included. The diagnosis of Oral Squamous Cell Carcinoma (OSCC) can be performed using high specificity and sensibility biomarkers that can be encountered in the biological fluids. Recent advances in salivary proteomics have underlined the potential use of salivary biomarkers as early diagnosis screening tools for oral neoplasia. In this respect, over 100 salivary molecules have been described and proposed as oral cancer biomarkers, out of which cytokines are among the most promising. Besides being directly involved in inflammation and immune response, the role of salivary cytokines in tumor growth and progression linked them to the incidence of oral malignant lesions. This review summarizes the existing studies based on the use of salivary cytokines as potential oral cancer biomarkers, their involvement in the malignant process based on their type, and ther influence upon prognostic and metastatic rates.

Integrated Bioinformatics Analysis of mRNAs and miRNAs Identified Potential Biomarkers of Oral Squamous Cell Carcinoma

Background: Oral cancer is a frequently encountered neoplasm of the head and neck region, being the eighth most common type of human malignancy worldwide. Despite improvement in its control, morbidity and mortality, rates have improved little in the past decades. The present investigations about gene interaction and pathways still could not clear the appearance and development of oral squamous cell carcinoma (OSCC), completely. The aim of this study is to investigate the key genes and microRNAs interaction in OSCC. Materials and Methods: The microarray datasets GSE13601 and GSE98463, including mRNA and miRNA profiles, were extracted from the GEO database and were analyzed using GEO2R. Functional and pathway enrichment analyses were performed by using the DAVID database. The protein-protein interaction (PPI) network was constructed and analyzed using STRING database and Cytoscape software, respectively. Finally, miRDB was applied to predict the targets of the differentially expressed miRNAs (DEMs). Results: Totally, 97 differentially expressed genes (DEGs) were found in OSCC, including 66 up-regulated and 31 down-regulated genes. The gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses showed that up-regulated genes were significantly enriched in movement of cell or subcellular component, cell adhesion, biological adhesion, cellular localization, apoptotic signaling pathway, while the downregulated genes were enriched in muscle system process and oxidation-reduction process. From the PPI network, the top 10 nodes with the highest degree were detected as hub genes. In addition, 18 DEMs were screened, which included 7 up-regulated and 11 down-regulated miRNAs. STAT1 was potentially targeted by three miRNAs, including has-miR- 6825-5P, has-miR-4495, and has-miR-5580-3P. Conclusion: The roles of DEMs such as hsa-mir-5580-3p in OSCC through interactions with DEGs CD44, ACLY, ACTR3, STAT1, LAMC2 and YWHAZ may offer a suitable candidate biomarker pattern for diagnosis, prognosis and treatment processes in OSCC.

Identification of the Key Genes of Autism Spectrum Disorder Through Protein-Protein Interaction Network

Background:

Currently, the prevalence of autism spectrum disorder (ASD) is increasing, which widely spurs the interest in the molecular investigation. Thereby, a better understanding of the given disorder mechanisms is likely to be achieved. Bioinformatics suiting protein-protein interactions analysis via the application of high-throughput studies, such as protein array, is one of these achievements.

Materials and Methods:

The gene expression data from Gene Expression Omnibus (GEO) database were downloaded, and the expression profile of patients with developmental delay and autistic features were analyzed via Cytoscape and its relevant plug-ins.

Results:

Our findings indicated that EGFR, ACTB, RHOA, CALM1, MAPK1, and JUN genes as the hub-bottlenecks and their related terms could be important in ASD risk. In other words, any expression modification in these genes could trigger dysfunctions in the corresponding biological processes.

Conclusion:

We suggest that differentially expressed genes could be used as suitable targets for ASD after being validated.