Integrated analysis revealing genome-wide chromosomal copy number variation in supraglottic laryngeal squamous cell carcinoma

Multi-Omics Analysis of the Effects of Smoking on Human Tumors

Comprehensive studies on cancer patients with different smoking histories, including non-smokers, former smokers, and current smokers, remain elusive. Therefore, we conducted a multi-omics analysis to explore the effect of smoking history on cancer patients. Patients with smoking history were screened from The Cancer Genome Atlas database, and their multi-omics data and clinical information were downloaded. A total of 2,317 patients were included in this study, whereby current smokers presented the worst prognosis, followed by former smokers, while non-smokers showed the best prognosis. More importantly, smoking history was an independent prognosis factor. Patients with different smoking histories exhibited different immune content, and former smokers had the highest immune cells and tumor immune microenvironment. Smokers are under a higher incidence of genomic instability that can be reversed following smoking cessation in some changes. We also noted that smoking reduced the sensitivity of patients to chemotherapeutic drugs, whereas smoking cessation can reverse the situation. Competing endogenous RNA network revealed that mir-193b-3p, mir-301b, mir-205-5p, mir-132-3p, mir-212-3p, mir-1271-5p, and mir-137 may contribute significantly in tobacco-mediated tumor formation. We identified 11 methylation driver genes (including EIF5A2, GBP6, HGD, HS6ST1, ITGA5, NR2F2, PLS1, PPP1R18, PTHLH, SLC6A15, and YEATS2), and methylation modifications of some of these genes have not been reported to be associated with tumors. We constructed a 46-gene model that predicted overall survival with good predictive power. We next drew nomograms of each cancer type. Interestingly, calibration diagrams and concordance indexes are verified that the nomograms were highly accurate for the prognosis of patients. Meanwhile, we found that the 46-gene model has good applicability to the overall survival as well as to disease-specific survival and progression-free intervals. The results of this research provide new and valuable insights for the diagnosis, treatment, and follow-up of cancer patients with different smoking histories.

Long Noncoding RNA CCDC26 Promotes Thyroid Cancer Malignant Progression via miR-422a/EZH2/Sirt6 Axis

Purpose

Long noncoding RNAs are crucial regulators in thyroid cancer progression. However, the role of lncRNA CCDC26 in thyroid cancer remains unclear. Here, we aimed to explore the effect of CCDC26 on thyroid cancer progression and the underlying mechanism.

Materials and Methods

A total of 50 clinical thyroid cancer samples were studied in patients' samples, cultured cells, and nude mice before and after treatment using quantitative reverse transcription-PCR, CCK-8 assays, BrdU incorporation assays, Transwell assays, cell apoptosis analysis, luciferase reporter gene assay, RNA immunoprecipitation, Western blot analysis, and tumorigenicity analysis.

Results

CCDC26 expression was elevated in patients' thyroid cancer tissues and thyroid cancer cell lines. CCDC26 depletion remarkably reduced proliferation, invasion, and migration but induced apoptosis of thyroid cancer cells. Mechanically, miR-422a mimic remarkably reduced the luciferase activity of CCDC26 transfected cells but failed to affect cells transfected with CCDC26 containing the mutated miR-422a-binding site. RNA immunoprecipitation (RIP) assays showed that CCDC26 and miR-422a preferentially interacted with Ago2, but not IgG, in the micro-ribonucleoprotein complexes (miRNPs). CCDC26 depletion enhanced miR-422a expression and MiR-422a inhibitor reversed CCDC26 knockdown-induced inhibition of thyroid cancer progression in vitro. CCDC26 upregulated EZH2 and Sirt6 expression by sponging miR-422a in thyroid cancer cells. Tumorigenicity analysis in nude mice revealed that CCDC26 contributed to thyroid tumor growth via miR-422a/EZH2/Sirt6 axis in vivo.

Conclusion

CCDC26 promotes thyroid cancer malignant progression via miR-422a/EZH2/Sirt6 axis. This finding provides new insights into the mechanism by which CCDC26 promotes malignant thyroid cancer development, advances our understanding of lncRNAs' association with thyroid cancer, and indicates that CCDC26 and miR-422a may serve as potential targets for thyroid cancer.