Evolution of gene expression signature in mammary gland stem cells from neonatal to old mice.

During the lifetime of females, mammary epithelial cells undergo cyclical expansion and proliferation depending on the cyclical activation of mammary gland stem/progenitor cells (MaSCs) in response to the change of hormone level. The structural shrink of mammary duct tree and the functional loss of mammary gland occur along with inactivation of MaSCs in old females, even leading to breast cancer occasionally. However, the gene expression signature in MaSCs across the lifespan remains unclear. Herein, we tested the tissue regeneration ability of CD24+CD49fhigh MaSCs over six time points from neonatal (4-day-old) to aged mice (360-day-old). Further RNA-seq analyses identified four clusters of gene signatures based on the gene expression patterns. A subset of stemness-related genes was identified, showing the highest level at day 4 of the neonatal age, and the lowest level at the old age. We also identified an aging-related gene signature showing significant change in the old mice, in which an association between aging process and stemness loss was indicated. The aging-related gene signature showed regulation of cancer signaling pathways, as well as aging-related diseases including Huntington disease, Parkinson disease, and Alzheimer disease. Moreover, 425, 1056, 418, and 1107 gene variants were identified at D20, D40, D90, and D180, respectively, which were mostly reported to associated with tumorigenesis and metastasis in cancer. In summary, the current study is the first to demonstrate the gene expression shift in MaSCs from neonatal to aging, which leads to stemness loss, aging, aging-related diseases, and even breast cancer in old mice.

Ginsenoside Rg3 inhibits colorectal tumor growth via down-regulation of C/EBPß/NF-κB signaling.

Colorectal cancer (CRC), the third most frequent occurred cancer, is associated with high mortality and extremely poor prognosis. Ginsenoside Rg3 (Rg3), one of the pharmacologically active components of traditional Chinese herbal medicine Panax ginseng, exerts antitumor effects against several types of cancer growth, including colorectal cancer. However, the detailed molecular mechanisms and particularly the signaling pathways that are decisive in this process are not yet fully elucidated. The present study was carried out to determine the antitumor effects of Rg3 using human colorectal cells in vitro and Xenograft tumor model of human colon cancer in vivo. We found that Rg3 effectively suppressed the proliferation of cancer cells in three human colorectal cancer cell lines (HCT116, HT29, SW480). In addition, intraperitoneal injection of Rg3 for 3 weeks significantly inhibited the growth of xenografts in nude mice. Furthermore, we determined the potential underlying mechanisms for these actions. Treatment with Rg3 significantly inhibited the transactivation of C/EBPß and NF-κB, as well as the association of C/EBPß with p65-NFκB in nucleus. However, when SW-480 cells were co-transfected with C/EBPß, or pretreatment with TNFα, Rg3 failed to inhibit tumor growth. Taken together, our results revealed a robust anti-tumor effect of Rg3, which is mediated by inhibition of C/EBPß/NF-κB signaling.

miR-17/20 sensitization of breast cancer cells to chemotherapy-induced apoptosis requires Akt1.

The serine threonine kinase Akt1 has been implicated in the control of cellular metabolism, survival and growth. Herein, disruption of the ubiquitously expressed member of the Akt family of genes, Akt1, in the mouse, demonstrates a requirement for Akt1 in miRNA-mediated cellular apoptosis. The miR-17/20 cluster is known to inhibit breast cancer cellular proliferation through G1/S cell cycle arrest via binding to the cyclin D1 3'UTR. Here we show that miR-17/20 overexpression sensitizes cells to apoptosis induced by either Doxorubicin or UV irradiation in MCF-7 cells via Akt1. miR-17/20 mediates apoptosis via increased p53 expression which promotes Akt degradation. Akt1⁻/⁻ mammary epithelial cells which express Akt2 and Akt3 demonstrated increased apoptosis to DNA damaging agents. Akt1 deficiency abolished the miR-17/20-mediated apoptosis. These results demonstrated a novel pathway through which miR17/20 regulate p53 and Akt controlling breast cancer cell apoptosis.

Mimic of manganese superoxide dismutase to induce apoptosis of human non-Hodgkin lymphoma Raji cells through mitochondrial pathways.

Increased reactive oxygen species (ROS) such as superoxide have been implicated as causal elements of oncogenesis. A variety of cancers have displayed changes in steady-state levels of key antioxidant enzymes, with the mitochondrial form of superoxide dismutase (MnSOD) being commonly implicated. Increasing MnSOD expression suppresses the malignant phenotype in various cancer cell lines and suppresses tumor formation in xenograft and transgenic mouse models. In this study, we examined the anti-proliferation effect of mimic of manganese superoxide dismutase (MnSODm) on human non-Hodgkin lymphoma Raji cells. The results showed that MnSODm significantly reduced the proliferation of Raji cells in a concentration and a time-dependent manner. By flow cytometric analysis, we found that MnSODm treatment resulted in an increased apoptosis in Raji cells. MnSODm also increased the production of ROS and the expression levels of cleaved caspase-9, caspase-3, poly (ADP-ribose) polymerase (PARP) and Bax in Raji cells. Moreover, the expression of Bcl-2 protein showed down-regulation in the MnSODm treatment group. In addition, MnSODm significantly elevated the level of cytochrome c in cytosol. These findings suggest that the activation of the mitochondrial pathway is involved in MnSODm-induced apoptosis in Raji cells.

Ginsenoside Rd attenuates the inflammatory response via modulating p38 and JNK signaling pathways in rats with TNBS-induced relapsing colitis.

In this study, we investigated the effects and the protective mechanism of ginsenoside Rd (GRd) which has been identified as one of the effective compounds from ginseng on relapsing colitis model induced by 2,4,6-trinitrobenzenesulfonic acid (TNBS) in rats. After inducing relapsing colitis in experimental rats on two occasions by intracolonic injection of TNBS, GRd (10, 20 and 40 mg/kg) was administered to experimental colitis rats for 7 days. The inflammatory degree was assessed by macroscopic score, histology and myeloperoxidase (MPO) activity. The levels of proinflammatory cytokines, such as TNF-α, IL-1ß, and IL-6 were determined by ELISA. Mitogen-activated protein kinase (MAPK) phosphorylation was analyzed by western blotting method. The results showed that GRd markedly attenuates the inflammatory response to TNBS-induced relapsing colitis, as evidenced by improved signs, increased body weight, decreased colonic weight/length ratio, reduced colonic macroscopic and microscopic damage scores, inhibited the activity of MPO, lowered proinflammatory cytokine levels and suppressed phosphorylation of p38 and JNK. The possible mechanism of protection on experimental colitis after GRd administration was that it could reduce the accumulation of leukocytes and down-regulate multiple proinflammatory cytokines through modulation of JNK and p38 activation.

Proanthocyanidins from grape seeds modulates the nuclear factor-kappa B signal transduction pathways in rats with TNBS-induced recurrent ulcerative colitis.

The aim of this study was to elucidate the molecular mechanisms involved in the therapeutic effects of proanthocyanidins from grape seeds (GSPE) on recurrent ulcerative colitis (UC) in rats. GSPE in doses of 100, 200, and 400mg/kg were intragastrically administered per day for 7 days after recurrent colitis was twice-induced by TNBS. The levels of GSH, as well as the activity of GSH-Px and SOD in colon tissues were measured by biochemical methods. The expression levels of tumor necrosis factor-α (TNF-α) and the nuclear translocation levels of nuclear factor-kappa B (NF-κB) in the colon tissues were measured by enzyme-linked immunosorbent assay methods. Western blotting analysis was used to determine the protein expression levels of inhibitory kappa B-alpha (IκBα), inhibitor kappa B kinase (IKKα/ß), phosphorylated IκBα and phosphorylated IKKα/ß. GSPE treatment was associated with a remarkable increased the activity of GSH-Px and SOD with GSH levels in TNBS-induced recurrent colitis rats as compared to the model group. GSPE also significantly reduced the expression levels of TNF-α, p-IKKα/ß, p-IκBα and the translocation of NF-κB in the colon mucosa. GSPE exerted a protective effect on recurrent colitis in rats by modifying the inflammatory response and promoting damaged tissue repair to improve colonic oxidative stress. Moreover, GSPE inhibited the TNBS-induced inflammatory of recurrent colitis though blocking NF-κB signaling pathways.

Effects of proanthocyanidins from grape seed on treatment of recurrent ulcerative colitis in rats.

The aim of the present study was to investigate the therapeutic effect and mechanism of proanthocyanidins from grape seed (GSPE) in the treatment of recurrent ulcerative colitis (UC) in rats. To induce recurrent colitis, rats were instilled with 2,4,6-trinitrobenzenesulfonic acid (TNBS) (80 mg/kg) into the colon through the cannula in the first induced phase, and then the rats were instilled a second time with TNBS (30 mg/kg) into the colon on the sixteenth day after the first induction UC. Rats were intragastrically administered GSPE (200 mg/kg) per day for 7 days after twice-induced colitis by TNBS. Sulfasalazine at 500 mg/kg was used as a positive control drug. Rats were killed 7 days after GSPE treatment. The colonic injury and inflammation were assessed by macroscopic and macroscopic damage scores, colon weight/length ratio (mg/cm), and myeloperoxidase activity. Then, superoxide dismutase, glutathione peroxidase, inducible nitric oxide synthase (iNOS) activities, and the levels of malonyldialdehyde, glutathione, and nitric oxide in serum and colonic tissues were measured. Compared with the recurrent UC group, GSPE treatment facilitated recovery of pathologic changes in the colon after induction of recurrent colitis, as demonstrated by reduced colonic weight/length ratio and macroscopic and microscopic damage scores. The myeloperoxidase and iNOS activities with malonyldialdehyde and nitric oxide levels in serum and colon tissues of colitis rats were significantly decreased in the GSPE group compared with those in the recurrent UC group. In addition, GSPE treatment was associated with notably increased superoxide dismutase, glutathione peroxidase activities, and glutathione levels of colon tissues and serum of rats. GSPE exerted a protective effect on recurrent colitis in rats by modifying the inflammatory response, inhibiting inflammatory cell infiltration and antioxidation damage, promoting damaged tissue repair to improve colonic oxidative stress, and inhibiting colonic iNOS activity to reduce the production of nitric oxide.