lithium-chloride and Head-and-Neck-Neoplasms

Several signaling pathways are aberrantly activated in head and neck squamous cell carcinoma (HNSCC), including the Hedgehog-Gli (HH-GLI), WNT, EGFR, and NOTCH pathways. The HH-GLI pathway has mostly been investigated in the context of canonical signal transduction and the inhibition of the membrane components of the pathway. In this work we investigated the role of downstream inhibitors GANT61 and lithium chloride (LiCl) on cell viability, wound closure, and colony forming ability of HNSCC cell lines. Five HNSCC cell lines were treated with HH-GLI pathway inhibitors affecting different levels of signal transduction. GANT61 and LiCl reduce the proliferation and colony formation capabilities of HNSCC cell lines, and LiCl has an additional effect on wound closure. The major effector of the HH-GLI signaling pathway in HNSCC is the GLI3 protein, which is expressed in its full-length form and is functionally regulated by GSK3β. LiCl treatment increases the inhibitory Ser9 phosphorylation of the GSK3β protein, leading to increased processing of GLI3 from full-length to repressor form, thus inhibiting HH-GLI pathway activity. Therefore, downstream inhibition of HH-GLI signaling may be a promising therapeutic strategy for HNSCC.

Topics: Antimanic Agents; Apoptosis; Biomarkers, Tumor; Cell Proliferation; Gene Expression Regulation, Neoplastic; Glycogen Synthase Kinase 3 beta; Head and Neck Neoplasms; Humans; Lithium Chloride; Nerve Tissue Proteins; Pyridines; Pyrimidines; Tumor Cells, Cultured; Zinc Finger Protein Gli3

The preparation of single-cell suspensions from 25 human head and neck tumors is described. Dispersal was performed overnight at 4 degrees C under slight agitation of the tissue suspensions using various combinations of enzymes and additives. The cell suspensions were examined for number of cells released, viability, amount of debris, and DNA distribution by means of flow cytometry (FCM). It was shown that both trypsin/dithioerythritol (TD) and collagenase/D Nase (CDse) were of value in dispersing single cells from tumor tissue. In contrast to CDse, incubation with TD appeared to be cytolytic to normal lymphocytes. In a number of cases, DNA-FCM revealed ploidy abnormalities in a TD-suspension, which were not discernible in the concurrent CDse-suspension. Cell culture of primary cell suspensions corroborated the reliability of the DNA-FCM measurements. Pretreatment with CDse improved tumor disaggregation by TD and indicated a different dispersal capacity. Addition of Ca2+ and Mg2+ ions to the dispersal mixtures and preincubation of tumor slices in complete medium for 1 day before initiation of cell dispersion influenced favorably the quality of the cell suspension.

Topics: Adult; Aged; Cell Separation; Chlorides; Deoxyribonuclease I; Dithioerythritol; DNA, Neoplasm; Female; Flow Cytometry; Head and Neck Neoplasms; Humans; Hyaluronoglucosaminidase; Lithium; Lithium Chloride; Male; Microbial Collagenase; Middle Aged; Pepsin A; Ribonuclease, Pancreatic; Trypsin