ABSTRACT
BACKGROUND: Small cell lung cancer (SCLC) is a neuroendocrine tumor with poor prognosis. Neuroendocrine tumors possess characteristics of both nerve cells and hormone-secreting cells; therefore, targeting the neuronal properties of these tumors may lead to the development of new therapeutic options. Among the endogenous signaling pathways in the nervous system, targeting the glutamate pathway may be a useful strategy for glioblastoma treatment. Perampanel, an antagonist of the synaptic glutamate α-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid receptor (AMPAR), has been reported to be effective in patients with glioblastoma. In this study, we aimed to investigate the antitumor effects of AMPAR antagonists in human SCLC cell lines. METHODS: We performed to examine the expression of AMPAR using Western blot and immunohistochemical analysis. The antitumor effects of AMPAR antagonists on human SCLC cell lines were investigated in vitro and in vivo. We also analyzed the signaling pathway of AMPAR antagonists in SCLC cell lines. Statistical analysis was performed by the GraphPad Prism 6 software. RESULTS: We first examined the expression of endogenous AMPAR in six human SCLC cell lines, detecting AMPAR proteins in all of them. Next, we tested the anti-proliferative effect of two AMPAR antagonists, talampanel and cyanquixaline, using SCLC cells in vitro and in vivo. Both AMPAR antagonists inhibited cell proliferation and mitogen-activated protein kinase (MAPK) phosphorylation in SCLC cells in vitro. Further, we observed reduced proliferation of implanted cell lines in an in vivo setting, assessed by Ki-67 immunohistochemistry. Additionally, using immunohistochemical analysis we confirmed AMPAR protein expression in human SCLC samples. CONCLUSION: AMPAR may be a potential therapeutic target for SCLC.
ABSTRACT
OBJECTIVES: The aim of this study was to evaluate whether low skeletal muscle mass before initial treatment is an independent prognostic factor defining overall survival (OS) and progression-free survival (PFS) in patients diagnosed with stage III cervical cancer. METHODS: Body composition and clinicopathologic data were collected retrospectively. Information was extracted and analyzed from the medical records of 92 patients with stage III cervical cancer and undergoing concurrent chemoradiotherapy. Skeletal muscle mass in the L3 region was measured using cross-sectional computed tomography images and corrected for body surface area to calculate the skeletal muscle index (SMI). The primary outcome was OS, and the secondary outcome was PFS. Statistical analyses were performed using the Mann-Whitney U test. The Kaplan-Meier method was used to determine OS and PFS. Univariate and multivariate analyses were performed with Cox proportional hazard ratios. RESULTS: The optimal cutoff value for predicting 5-y survival was 35.6 cm2/m2, defined based on data derived from 24 patients with a low SMI and 68 patients without a low SMI. A low SMI was significantly associated with shorter OS (hazard ratio [HR], 2.470; 95% confidence interval [CI], 1.208-5.053; P = 0.013), with no significant difference in PFS (HR, 1.651; 95% CI, 0.876-3.110; P = 0.121). Multivariate analysis also identified a low SMI as an independent OS-defining prognostic factor (HR, 2.473; 95% CI, 1.151-5.314; P = 0.020). CONCLUSION: A low pretreatment SMI is an independent prognostic factor for OS in patients diagnosed with stage III cervical cancer and treated with concurrent chemoradiotherapy.
