SAG-dihydrochloride enhanced the expression of germ cell markers in the human bone marrow- mesenchymal stem cells (BM-MSCs) through the activation of GLI-independent hedgehog signaling pathway.

Different studies indicated that the enhancing the expression of germ cell markers improved the efficiency of stem cells in the generation of germ line cells. The aim of the present study was to investigate the effect of SAG-dihydrochloride on the expression of germ cell markers in the human bone marrow-mesenchymal stem cells (BM-MSCs). For this purpose, the human BM-MSCs were cultured in the medium containing different concentrations of SAG-dihydrochloride (10, 20 and 30 µM). After RNA extraction and cDNA synthesis, the expression level of PTCH1, GLI1, PLZF, DDX4 and STRA8 genes were determined by using SYBR Green Real time PCR. The analysis of the results obtained from PTCH1 and GLI1 expression indicated that SAG-dihydrochloride had the ability to enhance the expression of germ cell markers in a Gli-independent manner. Furthermore, the significant increased expression of STRA8 was observed in the BM-MSCs treated by 10 µM SAG-dihydrochloride for 4 and 6 days (p < 0.05). There was also the up-regulation of DDX4 in the BM-MSCs following treatment with 20 µM SAG-dihydrochloride for 4 and 6 days. The obtained results suggested that treatment with SAG-dihydrochloride increased the expression of germ cell markers in the human BM-MSCs through the activation of non-canonical sonic hedgehog signaling pathway.

Assessment of anti-cancer effects of koenimbine on colon cancer cells.

BACKGROUND: Recent studies have highlighted the role of natural elements in reduction of cancer cell growth and apoptosis. Koenimbine, a natural product isolated from Murraya koenigii (L) Spreng is a substance with cytotoxic effects on cancer cells. AIM: The effects of koenimbine on HT-29 and SW48 colon cancer cells were evaluated by MTT and Annexin V assays. Expression levels of Wnt/ß-catenin pathway genes were quantified by real time PCR. RESULTS: The IC50 values of koenimbine in HT-29 and SW48 was calculated to be 50 µg/ml based on the results of MTT assay. This value was 75 µg/ml in IEC-18 cells which were used as normal control. Annexin V assays revealed induction of cell apoptosis and necrosis in HT-29 and SW48 cells but not IEG18 cells by koenimbine. Koenimbin treatment resulted in significant down-regulation of CYCLD1 expression in SW48 cell line, but up-regulation of this gene in HT29 cell line. Expression of TBLR1, DKK1, GSK3B and ß-catenin was significantly decreased after koenimbin treatment in HT-19 cell line. Moreover, expression of DKK1 and GSK3B was significantly decreased after koenimbin treatment in SW-40 cell line. TCF4 expression was not detected in any of cell lines either before or after treatment with koenimbin. CONCLUSION: The current in vitro study showed the cytotoxic effects of koenimbin on two colon cancer cell lines and the effects of this substance on expression of selected genes from Wnt-ß catenin pathway. Future in vivo studies are needed before suggestion of this substance as an anti-cancer drug.

A spectroscopic investigation of the interaction between c-MYC DNA and tetrapyridinoporphyrazinatozinc(II).

The c-MYC gene plays an important role in the regulation of cell proliferation and growth and it is overexpressed in a wide variety of human cancers. Around 90% of c-MYC transcription is controlled by the nuclease-hypersensitive element III1 (NHE III1), whose 27-nt purine-rich strand has the ability to form a G-quadruplex structure under physiological conditions. Therefore, c-MYC DNA is an attractive target for drug design, especially for cancer chemotherapy. Here, the interaction of water-soluble tetrapyridinoporphyrazinatozinc(II) with 27-nt G-rich strand (G/c-MYC), its equimolar mixture with the complementary sequence (GC/c-MYC) and related C-rich oligonucleotide (C/c-MYC) is investigated. Circular dichroism (CD) measurements of the G-rich 27-mer oligonucleotide in 150 mM KCl, pH 7 demonstrate a spectral signature consistent with parallel G-quadruplex DNA. Furthermore, the CD spectrum of the GC rich oligonucleotide shows characteristics of both duplex and quadruplex structures. Absorption spectroscopy implies that the complex binding of G/c-MYC and GC/c-MYC is a two-step process; in the first step, a very small red shift and hypochromicity and in the second step, a large red shift and hyperchromicity are observed in the Q band. Emission spectra of zinc porphyrazine are quenched upon addition of three types of DNA. According to the results of spectroscopy, it can be concluded the dominant binding mode is probably, outside binding and end stacking.