u-0126 and Squamous-Cell-Carcinoma-of-Head-and-Neck

To explore the role of RN181 in the pathogenesis of oral squamous cell carcinoma (OSCC) cells via mediating ERK/MAPK signaling.. The expression of RN181 was detected in OSCC tissues and cells. CAL27 and SCC-15 cells were divided into Control, Empty, RN181, si-RN181, U0126 (an inhibitor of ERK/MAPK pathway) and si-RN181 + U0126 groups. MTT was used to determine cell proliferation, flow cytometry to determine cell cycle and apoptosis, Transwell assay and wound healing test to determine cell invasion and migration, respectively. Western blotting was used to measure the protein expression. Furthermore, a xenograft tumor model was established to observe the effect of RN181 on the in vivo growth of OSCC cells.. RN181 was down-regulated in OSCC tissues and cells. As compared to the Control group, CAL27 and SCC-15 cells in the RN181 group and U0126 group presented with decreases in the proliferation, invasion and migration, but increases in the cell ratio at the G0/G1 phase and apoptosis, while the p-ERK 1/2/ERK 1/2 was down-regulated. Cells in the si-RN181 group manifested the opposite changes. U0126 could reverse the positive effect of si-RN181 on the growth of OSCC cells. In vivo experiment demonstrated that the tumor growth and weight were reduced in the RN181 group, with decreased Ki67 positive expression and elevated TUNEL positive cells.. RN181 was down-regulated in OSCC, and it could inhibit the proliferation, invasion and migration, cause the G0/G1 arrest, while promote the apoptosis of OSCC cells via inhibiting ERK/MAPK pathway.

Topics: Adult; Aged; Animals; Apoptosis; Butadienes; Cell Cycle; Cell Line, Tumor; Cell Movement; Cell Proliferation; Extracellular Signal-Regulated MAP Kinases; Female; Gene Expression Profiling; Humans; Ki-67 Antigen; Male; MAP Kinase Signaling System; Mice; Mice, Nude; Middle Aged; Mouth Neoplasms; Neoplasm Transplantation; Nitriles; Signal Transduction; Squamous Cell Carcinoma of Head and Neck; Ubiquitin-Protein Ligases; Wound Healing

Galanin and its receptors, GALR1 and GALR2, are tumor suppressors and represent therapeutic targets in head and neck squamous cell carcinoma (HNSCC). In the present study, it was demonstrated that the re‑expression of GALR1 in GALR1 and GALR2‑negative HNSCC cells suppresses tumor cell proliferation. This is mediated via extracellular‑regulated protein kinase‑1/2 (ERK1/2)‑dependent effects on the cyclin‑dependent kinase inhibitors (CKI) and cyclin D1. In combination with galanin, GALR2 also suppressed proliferation by increasing CKI and decreasing cyclin D1 levels. In contrast to GALR1, overexpression of GALR2 also induced caspase‑3‑dependent apoptosis. It was identified that in GALR2‑transfected cells, galanin induced activation of ERK1/2 and suppressed cell proliferation. Galanin stimulation also decreased the expression of cyclin D1 and induced apoptotic DNA ladder formation in GALR2‑transfected cells. Pretreatment with the ERK1/2‑specific inhibitor U0126 and pertussis toxin prevented the suppression of cyclin D1 expression, however did not affect DNA ladder formation. In conclusion, GALR2 expression in the presence of galanin exerts antitumor effects via cell cycle arrest and apoptotic pathways, and reactivation of these pathways may have therapeutic benefits in HNSCC.

Topics: Antineoplastic Agents; Apoptosis; Butadienes; Carcinoma, Squamous Cell; Caspase 3; Cell Cycle Checkpoints; Cell Line, Tumor; Cell Proliferation; Cyclin D1; Galanin; Gene Expression Regulation; Head and Neck Neoplasms; Humans; MAP Kinase Signaling System; Nitriles; Receptor, Galanin, Type 2; Signal Transduction; Squamous Cell Carcinoma of Head and Neck