Do patients with cN0 oral squamous cell carcinoma benefit from elective neck dissection? A large-scale population-based study.

BACKGROUND: The neck management of clinical-nodal negative (cN0) oral squamous cell carcinoma (OSCC) remains controversial. Elective neck dissection (END) and observation are the main strategies, but it is still not clear who could benefit the most from END. The purpose of this study was to clarify the potential clinical factors that affect the therapeutic value of END and to explore the actual characteristics associated with benefit from END. METHODS: Patients with cN0 OSCC were identified in the SEER database from 2000 to 2019. 5-year Overall survival (OS) and disease-specific survival (DSS) were analyzed using the Kaplan‒Meier method, and the hazard ratios (HRs) for survival were estimated using the Cox regression model. Multiple subgroup analyses of DSS and OS among different factors, comparing END and No END, were performed. RESULTS: A total of 17,019 patients with cN0 OSCC were included. The basic survival analysis and Cox regression model showed that END increased the probability of 5-year DSS and OS and was an independent prognostic factor. However, among patients who underwent only primary tumor surgery, no significant differences were found between the END and No END groups in 5-year DSS (P = 0. 585) and OS (P = 0.465). Further subgroup analysis showed that primary sites and T stage, but not other factors, might influence the benefit of END. Significant differences were found for T1 (P < 0.001 for OS) and T2 (P = 0.001 for DSS and < 0.001 for OS) tongue squamous cell carcinoma (TSCC) but not for other primary tumor sites. CONCLUSION: This large-scale retrospective population-based cohort study suggests that not all patients with cN0 OSCC could benefit from END. Patients with cN0 TSCC are recommended to undergo END, especially with early-stage tumors.

Metabolic Patterns of High-Invasive and Low-Invasive Oral Squamous Cell Carcinoma Cells Using Quantitative Metabolomics and 13C-Glucose Tracing.

Most current metabolomics studies of oral squamous cell carcinoma (OSCC) are mainly focused on identifying potential biomarkers for early screening and diagnosis, while few studies have investigated the metabolic profiles promoting metastasis. In this study, we aimed to explore the altered metabolic pathways associated with metastasis of OSCC. Here, we identified four OSCC cell models (CAL27, HN6, HSC-3, SAS) that possess different invasive heterogeneity via the transwell invasion assay and divided them into high-invasive (HN6, SAS) and low-invasive (CAL27, HSC-3) cells. Quantitative analysis and stable isotope tracing using [U-13C6] glucose were performed to detect the altered metabolites in high-invasive OSCC cells, low-invasive OSCC cells and normal human oral keratinocytes (HOK). The metabolic changes in the high-invasive and low-invasive cells included elevated glycolysis, increased fatty acid metabolism and an impaired TCA cycle compared with HOK. Moreover, pathway analysis demonstrated significant differences in fatty acid biosynthesis; arachidonic acid (AA) metabolism; and glycine, serine and threonine metabolism between the high-invasive and low-invasive cells. Furthermore, the high-invasive cells displayed a significant increase in the percentages of 13C-glycine, 13C-palmitate, 13C-stearic acid, 13C-oleic acid, 13C-AA and estimated FADS1/2 activities compared with the low-invasive cells. Overall, this exploratory study suggested that the metabolic differences related to the metastatic phenotypes of OSCC cells were concentrated in glycine metabolism, de novo fatty acid synthesis and polyunsaturated fatty acid (PUFA) metabolism, providing a comprehensive understanding of the metabolic alterations and a basis for studying related molecular mechanisms in metastatic OSCC cells.

Validation of a High-Throughput Multiplex Genetic Detection System for Helicobacter pylori Identification, Quantification, Virulence, and Resistance Analysis.

Helicobacter pylori (H. pylori) infection is closely related to various gastroduodenal diseases. Virulence factors and bacterial load of H. pylori are associated with clinical outcomes, and drug-resistance severely impacts the clinical efficacy of eradication treatment. Existing detection methods are low-throughput, time-consuming and labor intensive. Therefore, a rapid and high-throughput method is needed for clinical diagnosis, treatment, and monitoring for H. pylori. High-throughput Multiplex Genetic Detection System (HMGS) assay was established to simultaneously detect and analyze a set of genes for H. pylori identification, quantification, virulence, and drug resistance by optimizing the singlet-PCR and multiple primers assay. Twenty-one pairs of chimeric primers consisted of conserved and specific gene sequences of H. pylori tagged with universal sequence at the 5' end were designed. Singlet-PCR assay and multiple primers assay were developed to optimize the HMGS. The specificity of HMGS assay was evaluated using standard H. pylori strains and bacterial controls. Six clinical isolates with known genetic background of target genes were detected to assess the accuracy of HMGS assay. Artificial mixed pathogen DNA templates were used to evaluate the ability to distinguish mixed infections using HMGS assay. Furthermore, gastric biopsy specimens with corresponding isolated strains were used to assess the capability of HMGS assay in detecting biopsy specimens directly. HMGS assay was specific for H. pylori identification. HMGS assay for H. pylori target genes detection were completely consistent with the corresponding genetic background. Mixed infection with different drug-resistant isolates of H. pylori could be distinguished by HMGS assay. HMGS assay could efficiently diagnose H. pylori infection in gastric biopsy specimens directly. HMGS assay is a rapid and high throughput method for the simultaneous identification and quantification of H. pylori, analysis of virulence and drug resistance in both isolated strains and biopsy specimens. It could also be used to distinguish the mixed infection with different resistant genotype strains. Furthermore, HMGS could detect H. pylori infection in gastric biopsy specimens directly.

Direct detection of Helicobacter pylori in biopsy specimens using a high-throughput multiple genetic detection system.

AIM: We evaluated the direct high-throughput multiple genetic detection system (dHMGS) for Helicobacter pylori in gastric biopsies. MATERIALS & METHODS: One hundred and thirty-three specimens were concurrently analyzed by dHMGS, rapid urease test, culture and sequencing. RESULTS: dHMGS was highly sensitive and specific for H. pylori identification compared with culture and rapid urease test. The correlation coefficient of the quantitative standard curve was R2 = 0.983. A significant difference in the relative H. pylori DNA abundance was found in different gastroduodenal diseases. Concordance rates between dHMGS and sequencing for resistance mutations were 97.1, 100.0, 85.3 and 97.1%, respectively. Finally, dHMGS could efficiently distinguish mixed infection in biopsy specimens. CONCLUSION: The dHMGS could efficiently diagnose and quantify H. pylori burden in biopsies, simultaneously screening for virulence, antibiotic resistance and presence of the multistrain infections.

In vitro selected Con1 subgenomic replicons resistant to 2'-C-methyl-cytidine or to R1479 show lack of cross resistance.

The HCV polymerase is an attractive target for the development of new and specific anti-HCV drugs. Herein, the characterization of the inhibitory effect of 2'-C-Methyl-Cytidine shows that it is a potent inhibitor of both genotype 1b and 1a HCV replicon replication, both of laboratory-optimized as well as of NS5B clinical isolates-chimera replicons. The corresponding 5'-triphosphate derivative is a potent inhibitor of native HCV replicase isolated from replicon cells and of the recombinant genotype 1b and 1a HCV polymerase-mediated RNA synthesis. Resistance to 2'-C-Methyl-Cytidine was mapped to amino acid substitution S282T in the NS5B coding region. Cross-resistance was observed to 2'-C-Methyl-Adenosine but not to interferon alpha-2a, to non-nucleoside HCV polymerase inhibitors or to R1479, a new and potent nucleoside inhibitor of NS5B polymerase. In vitro studies mapped resistance to R1479 to amino acid substitutions S96T and S96T/N142T of the NS5B polymerase. These mutations did not confer resistance to 2-C-Methyl-Cytidine, thus confirming the lack of cross-resistance between these two HCV inhibitors. These data will allow the optimization of new polymerase inhibitors and their use in combination therapy.