Significance: Oral squamous cell carcinoma (OSCC) accounts for 90% of oral cancers, and earlier detection efficiently increases the survival rate. Here, we used a comprehensive literature review to select candidates and used LC-multiple reaction monitoring-MS to qualitatively and quantitatively measure target proteins in saliva samples from individuals of the at-risk population in Taiwan. Statistical analysis of the results establishes a four-protein panel sufficient to detect 88.6% of early-stage patients and 91.6% of all patients with 80.4% specificity. This panel can also be used to evaluate the risk of malignant progression from high-risk oral potential malignant disorder. Our study offers a practical foundation for clinical trials examining the ability of this panel to enable early detection of OSCC, risk assessment for cancer development, and treatment monitoring.

During neoplastic development, a multitude of changes in genome-encoded information are progressively selected to confer growth and survival advantages to tumor cells. microRNAs-mRNAs regulatory networks, given their role as a critical layer of robust gene expression control, are frequently altered in neoplasm. However, whether and how these gene perturbations impact metabolic homeostasis remains largely unresolved.

Oral squamous cell carcinoma is a prominent cancer worldwide, particularly in Taiwan. By integrating omics analyses in 50 matched samples, we uncover in Taiwanese patients a predominant mutation signature associated with cytidine deaminase APOBEC, which correlates with the upregulation of APOBEC3A expression in the APOBEC3 gene cluster at 22q13. APOBEC3A expression is significantly higher in tumors carrying APOBEC3B-deletion allele(s). High-level APOBEC3A expression is associated with better overall survival, especially among patients carrying APOBEC3B-deletion alleles, as examined in a second cohort (n = 188; p = 0.004). The frequency of APOBEC3B-deletion alleles is ~50% in 143 genotyped oral squamous cell carcinoma -Taiwan samples (27A3B^−/−:89A3B^+/−:27A3B^+/+), compared to the 5.8% found in 314 OSCC-TCGA samples. We thus report a frequent APOBEC mutational profile, which relates to a APOBEC3B-deletion germline polymorphism in Taiwanese oral squamous cell carcinoma that impacts expression of APOBEC3A, and is shown to be of clinical prognostic relevance. Our finding might be recapitulated by genomic studies in other cancer types.

Background: Pathogenic protozoans use extracellular vesicles (EVs) for intercellular communication and host manipulation.Acanthamoeba castellaniiis a free-living protozoan that may cause severe keratitis and fatal granulomatous encephalitis. Although several secreted molecules have been shown to play crucial roles in the pathogenesis ofAcanthamoeba, the functions and components of parasite-derived EVs are far from understood.Methods: Purified EVs fromA. castellaniiwere confirmed by electron microscopy and nanoparticle tracking analysis. The functional roles of parasite-derived EVs in the cytotoxicity to and immune response of host cells were examined. The protein composition in EVs fromA. castellaniiwas identified and quantified by LC-MS/MS analysis.Results: EVs fromA. castellaniifused with rat glioma C6 cells. The parasite-derived EVs induced an immune response from human THP-1 cells and a cytotoxic effect in C6 cells. Quantitative proteomic analysis identified a total of 130 proteins in EVs. Among the identified proteins, hydrolases (50.2%) and oxidoreductases (31.7%) were the largest protein families in EVs. Furthermore, aminopeptidase activities were confirmed in EVs fromA. castellanii.Conclusions: The proteomic profiling and functional characterization of EVs fromA. castellaniiprovide an in-depth understanding of the molecules packaged into EVs and their potential mechanisms mediating the pathogenesis of this parasite.

Oral squamous cell carcinoma (OSCC) accounts for >90% of cases of oral cancer, including cancer at the lip and oral cavity and cancer at the oropharynx. Most OSCCs develop from oral potentially malignant disorders (OPMDs), which consist of heterogeneous lesions with different malignant transformation potentials that make early detection of OSCC a challenge. Using a targeted mass spectrometry-based assay to compare multiple candidate proteins, we previously identified matrix metalloproteinase-1 (MMP-1) as one of the most promising salivary OSCC biomarkers. To explore the clinical utility of MMP-1 in OSCC detection, we developed an in-house, sensitive enzyme-linked immunosorbent assay (ELISA) for measuring MMP-1 content, and tested it on saliva samples from 1160 subjects (313 healthy controls, and 578 OPMD and 269 OSCC patients) collected at two medical centers. Salivary MMP-1 levels measured by our in-house ELISA significantly discriminated OSCC patients from non-cancerous groups. A receiver operating characteristic curve analysis showed that MMP-1 was effective in separating non-cancer groups from patients with OSCCs at the oral cavity. Additionally, salivary MMP-1 levels in oral cavity cancer patients were highly correlated with tumor progression (tumor size, lymph node metastasis, and overall stage). Collectively, our results indicate that salivary MMP-1 is an effective biomarker for OSCC that can be sensitively detected using our newly developed ELISA. The newly developed MMP-1 ELISA may be used as a new adjunctive tool to aid in detecting and monitoring OSCC.