Breast carcinogenesis is a multistep process involving both genetic and epigenetic changes. Since epigenetic changes like histone modifications are potentially reversible processes, much effort has been directed toward understanding this mechanism with the goal of finding novel therapies as well as more refined diagnostic and prognostic tools in breast cancer. Lysine-specific demethylase 1 (LSD1) plays a key role in the regulation of gene expression by removing the methyl groups from methylated lysine 4 of histone H3 and lysine 9 of histone H3. LSD1 is essential for mammalian development and involved in many biological processes. Considering recent evidence that LSD1 is involved in carcinogenesis, we investigated the role of LSD1 in breast cancer. Therefore, we developed an enzyme-linked immunosorbent assay to determine LSD1 protein levels in tissue specimens of breast cancer and measured very high LSD1 levels in estrogen receptor (ER)-negative tumors. Pharmacological LSD1 inhibition resulted in growth inhibition of breast cancer cells. Knockdown of LSD1 using small interfering RNA approach induced regulation of several proliferation-associated genes like p21, ERBB2 and CCNA2. Additionally, we found that LSD1 is recruited to the promoters of these genes. In summary, our data indicate that LSD1 may provide a predictive marker for aggressive biology and a novel attractive therapeutic target for treatment of ER-negative breast cancers.

Aberrant epigenetic changes in DNA methylation and histone acetylation are hallmarks of most cancers, whereas histone methylation was previously considered to be irreversible and less versatile. Recently, several histone demethylases were identified catalyzing the removal of methyl groups from histone H3 lysine residues and thereby influencing gene expression. Neuroblastomas continue to remain a clinical challenge despite advances in multimodal therapy. Here, we address the functional significance of the chromatin-modifying enzyme lysine-specific demethylase 1 (LSD1) in neuroblastoma. LSD1 expression correlated with adverse outcome and was inversely correlated with differentiation in neuroblastic tumors. Differentiation of neuroblastoma cells resulted in down-regulation of LSD1. Small interfering RNA-mediated knockdown of LSD1 decreased cellular growth, induced expression of differentiation-associated genes, and increased target gene-specific H3K4 methylation. Moreover, LSD1 inhibition using monoamine oxidase inhibitors resulted in an increase of global H3K4 methylation and growth inhibition of neuroblastoma cells in vitro. Finally, targeting LSD1 reduced neuroblastoma xenograft growth in vivo. Here, we provide the first evidence that a histone demethylase, LSD1, is involved in maintaining the undifferentiated, malignant phenotype of neuroblastoma cells. We show that inhibition of LSD1 reprograms the transcriptome of neuroblastoma cells and inhibits neuroblastoma xenograft growth. Our results suggest that targeting histone demethylases may provide a novel option for cancer therapy.

11Purple-fleshed sweet potato P40 has been shown to prevent colorectal cancer in a murine 12 model. This study is to identify anthocyanins by using HPLC/MS-MS and assess the stability 13 during various cooking conditions. P40 possesses a high content of anthocyanins up to 14 mg/g 14 dry matter. Total 12 acylated anthocyanins are identified. Top three anthocyanins, e.g., cyanidin 15 3-caffeoyl-p-hydroxybenzoyl sophoroside-5-glucoside, peonidin 3-caffeoyl sophoroside-5-16 glucoside, and cyanidin 3-(6'' -caffeoyl-6''-feruloylsophoroside)-5-glucoside, account for half 17 of the anthocyanin contents. Over 80% of anthocyanins measured by acid hydrolysis were 18 cyanidin derivatives, indicating P40 is unique when compared with other purple-fleshed sweet 19 potatoes that usually contain more peonidin than cyanidin. Steaming, pressure cooking, 20 microwaving, and frying but not baking significantly reduced 8-16% of total anthocyanin 21 contents. Mono-acylated anthocyanins showed a higher resistance against heat than di-and non-22 acylated. Among of which, cyanidin 3-p-hydroxybenzoylsophoroside-5-glucoside exhibited the 23 best thermal stability. The stable acylated and cyanidin-predominated anthocyanins in P40 may 24 provide extra benefits for cancer prevention. 25Keywords: Anthocyanins / purple-fleshed sweet potato / cancer prevention / stability / cooking 26 conditions 27

Post-translational modifications of histones by chromatin modifying enzymes regulate chromatin structure and gene expression. As deregulation of histone modifications contributes to cancer progression, inhibition of chromatin modifying enzymes such as histone demethylases is an attractive therapeutic strategy to impair cancer growth. Lysine-specific demethylase 1 (LSD1) removes mono-and dimethyl marks from lysine 4 or 9 of histone H3. LSD1 in association with the androgen receptor (AR) controls androgen-dependent gene expression and prostate tumor cell proliferation, thus highlighting LSD1 as a drug target. By combining protein structure similarity clustering and in vitro screening, we identified Namoline, a cpyrone, as a novel, selective and reversible LSD1 inhibitor. Namoline blocks LSD1 demethylase activity in vitro and in vivo. Inhibition of LSD1 by Namoline leads to silencing of AR-regulated gene expression and severely impairs androgen-dependent proliferation in vitro and in vivo. Thus, Namoline is a novel promising starting compound for the development of therapeutics to treat androgen-dependent prostate cancer.Prostate cancer is the second leading cause of cancer deaths in Western countries. As long as tumors are prostate confined, they can be efficiently treated by surgery and/or radiation therapy in a curative intent. In cases, however, where the tumor has already disseminated an androgen ablation therapy has to be applied. 1 Patients initially respond to androgen ablation, but tumors become androgen resistant within a period of 12-18 months, 2 after which no curative treatment exists. Thus, the urgent need to identify novel therapeutic targets for the treatment of androgen-resistant prostate cancer is evident.We recently identified lysine-specific demethylase 1 (LSD1), an amine oxidase, as a novel target for prostate cancer therapy. 3 Expression of LSD1 positively correlates with the malignancy of prostate tumors. 3,4 LSD1 functions as a histone demethylase that removes mono-and dimethyl, but not trimethyl marks from either lysine 4 or lysine 9 of histone H3 (H3K4 and H3K9, respectively). 3,5 As a component of corepressor complexes, LSD1 demethylates active methyl marks at H3K4. 5,6 In comparison, when associated with the androgen receptor (AR), the enzyme removes repressive methyl marks from H3K9, thereby enhancing AR-dependent gene expression and prostate tumor cell proliferation. 3 Thus, we hypothesized that selective LSD1 inhibitors are useful precursors for the development of novel drugs for prostate cancer therapy.Previous studies showed that inhibitors of other members of the amine oxidase family also impair the activity of LSD1. 7-13 However, these amine oxidase inhibitors including clorgyline, pargyline, tranylcypromine, polyamines and derivatives thereof, many of them do not selectively target LSD1 and therefore, limits their use as therapeutics owing to potential side effects. In this study, we found a novel and selective LSD1 inhibitor called Namoline by combining protein structure similar...

Inflammation is a significant component of chronic neurodegenerative diseases. Cyclooxygenase-2 (COX-2) is expressed in activated microglial cells and appears to be an important source of prostaglandins during inflammatory conditions. To investigate the effect of curcumin on COX-2 gene expression in microglial cells, we treated lipopolysaccharide (LPS)-challenged BV2 microglial cells with various concentrations of curcumin. Curcumin significantly inhibited LPS-mediated induction of COX-2 expression in both mRNA and protein levels in a concentration-dependent manner. COX-2 enzyme activity was also inhibited in accordance with mRNA and protein levels. Furthermore, curcumin markedly inhibited LPS-induced nuclear factor kB (NF-kB) and activator protein 1 (AP-1) DNA bindings. These data suggest that curcumin suppresses LPS-induced COX-2 gene expression by inhibiting NF-k B and AP-1 DNA bindings in BV2 microglial cells.

Scope Anthocyanins, the natural pigments in plant foods, have been associated with cancer prevention. However, the content of anthocyanins in staple foods is typically low and the mechanisms by which they exert anti-cancer activity is not yet fully defined. Methods and results We selected an anthocyanin-enriched purple-fleshed sweet potato clone, P40, and investigated its potential anti-cancer effect in both in vitro cell culture and in vivo animal model. In addition to a high level of total phenolics and antioxidant capacity, P40 possesses a high content of anthocyanins at 7.5 mg/g dry matter. Treatment of human colonic SW480 cancer cells with P40 anthocyanin extracts at 0–40 μM of peonidin-3-glucoside equivalent resulted in a dose-dependent decrease in cell number due to cytostatic arrest of cell cycle at G1 phase but not cytotoxicity. Furthermore, dietary P40 at 10–30% significantly suppressed azoxymethane-induced formation of aberrant crypt foci in the colons of CF-1 mice in conjunction with, at least in part, a lesser proliferative PCNA and a greater apoptotic caspase-3 expression in the colon mucosal epithelial cells. Conclusion These observations, coupled with both in vitro and in vivo studies reported here, suggest anthocyanin-enriched sweet potato P40 may protect against colorectal cancer by inducing cell cycle arrest, anti-proliferative and apoptotic mechanisms.

These data show that caspase-8 and -9 are involved in the apoptotic effect of celecoxib in cervical cancer cells. This requires the FADD-dependent pathway in a cell type-specific manner. In addition, NF-kappaB may play a key role in celecoxib-induced apoptosis.

Tumor cells at the tumor margin lose epithelial properties and acquire features of mesenchymal cells, a process called epithelial-to-mesenchymal transition (EMT). Recently, features of EMT were shown to be linked to cells with tumor-founding capability, so-called cancer stem cells (CSCs). Inducers of the EMT include several transcription factors, such as Snail (SNAI1) and Slug (SNAI2), as well as the secreted transforming growth factor (TGFß). In the present study, we found that EMT induction in MCF10A cells by stably expressing SNAI1 contributed to drug resistance and acquisition of stem/progenitor-like character as shown by increased cell population for surface marker CD44+/CD24− and mammosphere forming capacity. Using a microarray approach, we demonstrate that SNAI1 overexpression results in a dramatic change in signaling pathways involved in the regulation of cell death and stem cell maintenance. We showed that NF-κB/MAPK signaling pathways are highly activated in MCF10A-SNAI1 cells by IL1ß stimulation, leading to the robust induction in IL6 and IL8. Furthermore, MCF10A-SNAI1 cells showed enhanced TCF/ß-catenin activity responding to the exogenous Wnt3a treatment. However, EMT-induced stem/progenitor cell activation process is tightly regulated in non-transformed MCF10A cells, as WNT5A and TGFB2 are strongly upregulated in MCF10A-SNAI1 cells antagonizing canonical Wnt pathway. In summary, our data provide new molecular findings how EMT contributes to the enhanced chemoresistance and the acquisition of stem/progenitor-like character by regulating signaling pathways.