The immunohistochemical expression of cyclin B1 is associated with higher maxSUV in 18F-FDG-PET in non-small cell lung cancer patients. Initial results

An-te-xiao capsule inhibits tumor growth in non-small cell lung cancer by targeting angiogenesis

An-te-xiao capsule consists of total alkaloids from the dried whole plantof Solanum lyratum, and showed antitumor effects in our previous study. However, its inhibitory effect on multiple non-small cell lung cancer (NSCLC) cell lines and the underlying mechanisms have not been elucidated clearly. This study sought to investigate the inhibitory effects of An-te-xiao capsule on three main types of NSCLC cell lines (A549, NCI-H460, and NCI-H520) in vitro and in vivo and the underlying mechanisms of action including its potential anti-angiogenesis effects. An-te-xiao capsule showed no acute oral toxicity in mice, and significantly prolonged survival time in a mouse model of Lewis tumor xenograft. The inhibition of A549, NCI-H460, and NCI-H520 cells by An-te-xiao capsule was reflected in its effects on tumor growth, histopathological changes, tumor microvessel density (MVD), cell cycle regulatory proteins, and cell apoptosis. In vitro, An-te-xiao capsule repressed migration, invasion, and tube formation of tumor-derived vascular endothelial cells (Td-ECs), which were obtained using a co-culture system, in the presence or absence of vascular endothelial growth factor (VEGF) at safe concentrations selected using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Moreover, An-te-xiao capsule inhibited the secretion of VEGF by A549 cells in the co-culture system and suppressed the phosphorylation of VEGF receptor 2 (VEGFR2). Taken together, An-te-xiao capsule has potential for treating NSCLC.

Activity of cyclin B1 in HL-60 cells treated with etoposide

Cyclin B1 triggers G2/M phase transition phosphorylating with its catalytical partner - Cdc2 many of the molecular targets essential for cell cycle progression. Human leukemia cell line HL-60 were treated with increasing doses of etoposide (ETP) (0.5; 0.75; 1μM) to investigate how the drug affects cell morphology, viability, cell cycle distribution and expression of cyclin B1. To achieve this aim we applied light and transmission electron microscopy to observe morphological and ultra structural changes, image-based cytometry for apoptosis evaluation and cell cycle analysis, and then we conducted immunohistochemical and immunofluorescence staining to visualize cyclin localization and expression. Quantitive data about cyclin B1 expression were obtained from flow cytometry. Etoposide caused decrease in cell viability, induced apoptosis and G2/M arrest accompanied by enhanced expression of cyclin B1. Changes in expression and localization of cyclin B1 may constitute a part of the mechanism responsible for resistance of HL-60 cells to etoposide. Our results may reflect involvement of cyclin B1 in opposite processes - apoptosis induction and maintenance of cell viability in leukemia cells. We hypothesized possible roles and pathways by which cyclin B1 takes part in drug treatment response and chemosensitivity.