Effect of Nanog overexpression on the metastatic potential of a mouse melanoma cell line B16-BL6

Nanog, a marker and regulator of the undifferentiated state in embryonic stem cells were anticipated to be an effective enhancer of cancer metastasis. We have developed a Nanog overexpressing mouse melanoma cell line B16-BL6 (BL6). BL6 was well recognized as a cell line with a high metastatic potential. In vitro tests revealed the enhancement of cell proliferation, wound healing activity, and matrix metalloproteinase 9 (MMP9) activity. Nanog-induced up- or down-regulated genes were comprehensively analyzed by transcriptome sequencing using Nanog+BL6 and wild-type BL6. Principally, up-regulated genes were involved in vesicle-aided glucose transport and oxidative phosphorylation, while down-regulated genes were associated with immunosuppression and apoptosis. A marked finding was that TGF-β1 was down-regulated, because TGF-β1 has been well discussed about its suppressive/progressive dual role in cancer. In vivo test showed that the number and volume of metastatic colonies of BL6 to lung were as high as 115 colonies/lung and 5.6 mm3/lung. Under this condition, Nanog overexpression caused a progressive effect (150 colonies/lung, p = 0.25; 9.2 mm3/lung, p = 0.13) rather than a suppressive effect on the metastasis. In this study, the effectiveness of Nanog overexpression in enhancing the metastatic potential of melanoma cell lines has been demonstrated for the first time.

Teraphtal decreased the sensitivity tumor cells to doxorubicine in vitro but does not affect its antitumor effect in vivo .

Introduction . Anthracycline antibiotic doxorubicin (DOX) is widely used in clinical oncology. It is known that hemin, endogenious compound, has the ability to modulate DOX cytotoxicity. We found that DOX toxicity against mammalian cancer cells can be decreased in vitro in the presence of teraftal (ТF), the component anticancer binaric catalytic system (TF + ascorbic acid).Purpose . To study the influence of TF on anticancer effect of DOX.Materials and methods . The mouse melanoma cell line B16 / F10 and mouse transplanted tumor B16 were used. The TF ability to protect from DOX-induced cell death were measured by MTT-assay, flow сytometry, light microscopy, cytochemical determination of ß-galactosidase expression, radiometric assay and tumor growth inhibition assay in vivo.Results. The sensitivity of mouse melanoma cell line B16 / F10 to DOX decreased in the presence TF (10–20 mkM) in the mean by 4–6 fold. The same mechanism takes part into the decrease of DOX cytotoxicity at the presence of TF / hemin khown which connects with the cell ability to accumulate of drug. TF protect the mouse melanoma cells B16 / F10 from apoptosis, induced by DOX throwing switching on cell premature senescence programme. The antitumor effect of DOX against mouse transplanted melanoma B16 at presence of TF was the same as DOX alone.Conclusions. The TF potency to decrease the sensitivity of cancer cells to DOX in vitro does not correlate with its ability to modulate аnthracycline antibiotics anticancer effect in vivo.

A New Tetrahydrofuran Lignan from Premna serratifolia Wood

Phytochemical investigation of the CHCl3 extract of Premna serratifolia (syn: P. integrifolia) wood collected in Myanmar led to the isolation of a new tetrahydrofuran type lignan, 7,9-dihydroxydolichanthin B (1), together with two known triterpenoids, oleanonic acid (2) and (2a, 3α)-dihydroxyolean-12-en-28-oic acid (3). The structure of the new compound was determined using various spectroscopic techniques, mainly 1D- and 2D-NMR, HRESIMS, IR, and optical rotation, and by comparisons with the reported literatures. Compounds 1-3 had anti-melanin deposition activities against IBMX and α-MSH induced B16-F10 mouse melanoma cell line with IC50 values of 18.4, 17.7 and 11.2 μM, respectively. However, 2 exhibited cytotoxicity at concentrations above 50 μM.