ASPM facilitates colorectal cancer cells migration and invasion by enhancing ß-catenin expression and nuclear translocation.

Increased abnormal spindle-like microcephaly (ASPM) expression has been linked to clinical stage and poor prognosis in cancers, but the molecular mechanisms by which ASPM promotes cell metastasis in colorectal cancer (CRC) has not been identified. This study showed that the abilities of cell migration, invasion, and epithelial-mesenchymal transition (EMT) were attenuated in ASPM-deficient CRC cell lines. Furthermore, we reported that attenuation of ASPM expression inhibited CRC cell metastasis in vivo. Additionally, the expression of ASPM was positively correlated with ß-catenin level in CRC tissues. Mechanistically, ASPM can upregulate ß-catenin transcription by stimulating the ß-catenin promoter and enhancing the nuclear translocation of ß-catenin in CRC cells, which leads to the activation of the Wnt/ß-catenin pathway. Finally, we showed that ASPM effectively induced CRC cell migration and invasion in a ß-catenin-dependent manner.

Organic two-photon nanoparticles modulate reactive oxygen species, intracellular calcium concentration, and mitochondrial membrane potential during apoptosis of human gastric carcinoma SGC-7901 cells.

OBJECTIVES: To investigate the biocompatibility of human gastric carcinoma cells (SGC-7901) with organic two-photon nanoparticles (NPs). RESULTS: Different concentrations of NPs were incubated with SGC-7901 cells for different times. The levels of cell apoptosis, reactive oxygen species (ROS), intracellular calcium, and mitochondrial membrane potential (MMP) were measured by staining the SGC-7901 cells with Annexin V-FITC/PI, 2',7'-dichlorofluorescin diacetate, Fluo-3 AM, and Rhodamine 123, followed by the flow cytometry assay. NPs at <4 µg/ml, did not have any significant effect on apoptosis, necrosis, generation of ROS, increase of intracellular Ca(2+) concentration or decrease of MMP in SGC-7901 cells, but >4 µg/ml had a major effects on all the above mentioned parameters. CONCLUSION: 2,5,2',5'-Tetra(4-N,N-diphenylamine styryl) biphenyl NPs can be used at an appropriate concentration as a safe drug carrier or imaging marker and may serve as an effective tool for developing a photodynamic cancer therapy.