Objective: To establish a nude mouse model of subcutaneous lung cancer using dual fluorescence reporting genes of luciferase (Luc) and near-infrared fluorescent protein (iRFP). Methods: The Luc and iRFP expressed lentiviral vector was constructed by Gateway method. After verified by sequencing, the lentivirus particle was prepared and infected into lung cancer A549 cells. Successfully infected A549 (mA549) cells were selected by puromycin and amplified. The expression of Luc and iRFP were observed under fluorescence microscope, and the expression of c-Met protein on the cell surface was detected by immunofluorescence. Twelve female nude mice were randomly divided into 2 groups, 6 in each group. A549 and mA549 cells were inoculated subcutaneously into the right forelimb of nude mice. The growth and fluorescence expression of the tumor were observed by in vivo imaging. The tumor formation was evaluated by hematoxylin-eosin (HE) staining and immunohistochemistry. Results: The Luc and iRFP stably expressed mA549 cell line was successfully constructed. The expressions of iRFP and Luc in mA549 cells were observed under fluorescence microscope. The results of immunofluorescence showed that c-Met protein expressed in both A549 cells and mA549 cells. The growth period of mA549 xenograft in nude mice was moderate and the tumorigenesis rate was 100%. The growth trend of mA549 cells in vivo was not significantly different from that of A549 cells (P>0.05). HE staining and immunohistochemistry results showed that the tumor issues displayed typical histopathological features of tumor. Immunohistochemistry results showed that both A549 and mA549 tumors expressed c-Met protein. Conclusion A stable, real-time monitoring model of iRFP-Luc-A549 lung cancer cell xenograft in nude mice was successfully constructed.

OBJECTIVE: To explore the proliferation inhibitory effect of quinones from Blaps rynchopetera defense secretion on colorectal tumor cell lines. METHODS: Human colorectal cancer cell HT-29, human colorectal adenocarcinoma cell Caco-2 and normal human colon epithelial cell CCD841 were chosen for the evaluation of inhibitory activity of the main quinones of B. rynchopetera defense secretion, including methyl p-benzoquinone (MBQ), ethyl p-benzoquinone (EBQ), and methyl hydroquinone (MHQ), through methyl thiazolyl tetrazolium assay. The tumor-related factors, cell cycles, related gene expressions and protein levels were detected by enzyme-linked immunosorbent assy, flow cytometry, RT-polymerase chain reaction and Western blot, respectively. RESULTS: MBQ, EBQ, and MHQ could significantly inhibit the proliferation of Caco-2, with half maximal inhibitory concentration (IC₅₀) values of 7.04 ± 0.88, 10.92 ± 0.32, 9.35 ± 0.83, HT-29, with IC₅₀ values of 14.90 ± 2.71, 20.50 ± 6.37, 13.90 ± 1.30, and CCD841, with IC₅₀ values of 11.40 ± 0.68, 7.02 ± 0.44 and 7.83 ± 0.05 µg/mL, respectively. Tested quinones can reduce the expression of tumor-related factors tumor necrosis factor α, interleukin (IL)-10, and IL-6 in HT-29 cells, selectively promote apoptosis, and regulate the cell cycle which can reduce the proportion of cells in the G₁ phase and increase the proportion of the S phase. Meanwhile, tested quinones could up-regulate mRNA and protein expression of GSK-3β and APC, while down-regulate that of β-catenin, Frizzled1, c-Myc, and CyclinD1 in the Wnt/β-catenin pathway of HT-29 cells. CONCLUSION Quinones from B. rynchopetera defense secretion could inhibit the proliferation of colorectal tumor cells and reduce the expression of related factors, which would be functioned by regulating cell cycle, selectively promoting apoptosis, and affecting Wnt/β-catenin pathway-related mRNA and protein expressions.
Humans ; beta Catenin/metabolism* ; Caco-2 Cells ; Quinones/pharmacology* ; Glycogen Synthase Kinase 3 beta/metabolism* ; Cell Proliferation ; Colorectal Neoplasms/metabolism* ; Cell Line, Tumor ; Apoptosis ; Benzoquinones/pharmacology* ; RNA, Messenger ; Wnt Signaling Pathway