Change of the expression of human telomerase reverse transcriptase mRNA and human telomerase RNA after cisplatin and 5-fluorouracil exposure in head and neck squamous cell carcinoma cell lines

Potential Maneuvers for Providing Optimal Tidal Volume Using the One-Handed EC Technique

Bag-valve-mask is a device that manually provides positive oxygen pressure. The grip technique of the character E and C shape is recommended to carry out this effectively. However, when applying this method, the hand in which the direction of the EC technique should be performed and the degree of adhesion pressure while performing the technique are unknown. This study aims to identify the factors influencing tidal volume and to determine the ideal sealing method between mask and face in the one-handed EC technique to optimize the Vt. A simulation study was conducted using a mechanical lung model in a scenario that resembled respiratory arrest. Multiple regression analyses identified high peak pressure, high left spot adhesion strength of the mask, and low right spot and bottom spot adhesion strength of the mask as significant factors. To provide an optimal Vt, it may be necessary to apply more strength to the left area of the mask when forming the “C” shape with the thumb and index finger of left hand using the one-handed EC technique.

Stilbene Compounds Inhibit Tumor Growth by the Induction of Cellular Senescence and the Inhibition of Telomerase Activity

Cellular senescence is a state of cell cycle arrest characterized by a distinct morphology, gene expression pattern, and secretory phenotype. It can be triggered by multiple mechanisms, including those involved in telomere shortening, the accumulation of DNA damage, epigenetic pathways, and the senescence-associated secretory phenotype (SASP), and so on. In current cancer therapy, cellular senescence has emerged as a potent tumor suppression mechanism that restrains proliferation in cells at risk for malignant transformation. Therefore, compounds that stimulate the growth inhibition effects of senescence while limiting its detrimental effects are believed to have great clinical potential. In this review article, we first review the current knowledge of the pro- and antitumorigeneic functions of senescence and summarize the key roles of telomerase in the regulation of senescence in tumors. Second, we review the current literature regarding the anticancer effects of stilbene compounds that are mediated by the targeting of telomerase and cell senescence. Finally, we provide future perspectives on the clinical utilization of stilbene compounds, especially resveratrol and pterostilbene, as novel cancer therapeutic remedies. We conclude and propose that stilbene compounds may induce senescence and may potentially be used as the therapeutic or adjuvant agents for cancers with high telomerase activity.

Growth Inhibitory Effect of Palatine Tonsil-derived Mesenchymal Stem Cells on Head and Neck Squamous Cell Carcinoma Cells

Objectives

Mesenchymal stem cells (MSCs) play an important role in the development and growth of tumor cells. However, the effect of human MSCs on the growth of human tumors is not well understood. The purpose of this study is to confirm the growth effect of palatine tonsil-derived MSCs (TD-MSCs) on head and neck squamous cell carcinoma (HNSCC) cell lines and to elucidate the mechanism of their action.

Methods

TD-MSCs were isolated from patient with chronic tonsillitis and tonsillar hypertrophy. Two human HNSCC cell lines (PNUH-12 and SNU-899) were studied and cocultured with isolated palatine tonsil-derived MSC. The growth inhibitory effect of MSCs on HNSCC cell lines was tested through methylthiazolyldiphenyl-tetrazolium (MTT) assay. The apoptosis induction effect of MSCs on cell lines was assessed with flow cytometry and reverse transcriptase (RT)-PCR.

Results

Palatine tonsil-derived MSCs exhibited a growth inhibitory effect on both cell lines. Cell cycle analysis showed an accumulation of tumor cells predominantly in G0/G1 phase with an increase in concentration of TD-MSCs, which was confirmed by increased mRNA expression of cell cycle negative regulator p21. Apoptosis of tumor cells increased significantly as concentration of cocultured TD-MSCs increased. Additionally, mRNA expression of caspase 3 was upregulated with increased concentration of TD-MSCs.

Conclusion

TD-MSCs have a potential growth inhibitory effect on HNSCC cell lines in vitro by inducing apoptotic cell death and G1 phase arrest of cell lines.