Circadian (De)regulation in Head and Neck Squamous Cell Carcinoma

Abstract

Head and neck cancer encompass different malignancies that develop in and around the throat, larynx, nose, sinuses and mouth. Most head and neck cancers are squamous cell carcinomas (HNSCC) that arise in the flat squamous cells that makeup the thin layer of tissue on the surface of anatomical structures in the head and neck. Each year, HNSCC is diagnosed in more than 600,000 people worldwide, with about 50,000 new cases. HNSCC is considered extremely curable if detected early. But the problem remains in treatment of inoperable cases, residues or late stages. Circadian rhythm regulation has a big role in developing various carcinomas, and head and neck tumors are no exception. A number of studies have reported that alteration in clock gene expression is associated with several cancers, including HNSCC. Analyses on circadian clock genes and their association with HNSCC have shown that expression of PER1, PER2, PER3, CRY1, CRY2, CKIε, TIM, and BMAL1 are deregulated in HNSCC tissues. This review paper comprehensively presents data on deregulation of circadian genes in HNSCC and critically evaluates their potential diagnostics and prognostics role in this type of pathology.

Advances in DNA Repair—Emerging Players in the Arena of Eukaryotic DNA Repair

“…Moreover, CLOCK-BMAL1 complexes control expression of other genes containing E-boxes, collectively known as clock-controlled genes (CCGs) ( Figure 3) [146]. It has been estimated that expression of 2%-10% of mammalian genes is controlled by clock genes [147]. The central molecular clock, a pacemaker, is located in the anterior part of the hypothalamus called the suprachiasmatic nucleus (SCN).…”

“…Blue light is the strongest stimulus that entrains the central clock. Peripheral clocks, on the other hand, react to other stimuli [146][147][148]. The circadian clock has been reported to be involved in direct reversal of DNA damage through regulation of O6-methylguanine-DNA methyl transferase and alkylguanine DNA glycosylase.…”

Diagnostic value of exosomal circMYC in radioresistant nasopharyngeal carcinoma

“…37 The expression of CRY2 is deregulated in head and neck cancers, squamous cell carcinomas tissues, lung cancer, and breast cancer and is involved with epithelial-mesenchymal transition, Akt signaling and p53 signaling. [38][39][40] These signaling pathways have a very important role in the proliferation and apoptosis of NPC cells, suggesting that circMYC regulates these signaling pathways directly or indirectly, and ultimately affects the progress of NPC. The specific regulatory molecular mechanism still needs more experimental proof.…”

Silencing of NAMPT leads to up-regulation of insulin receptor substrate 1 gene expression in U87 glioma cells

“…The proteins encoding by PER2, GADD45A, and TPD52 genes are also involved in the cancer cell proliferation and tumor growth and are dysregulated in cancer cells (Wang et al 2016;Xiang et al 2018;Xiong et al 2018;Zhang et al 2018;Hu et al 2019;Rahman et al 2019). At the same time, the expression of these genes was resistant to the silencing of adipokine NAMPT in the glioma cells.…”