Flavonoids and Other Polyphenols Act as Epigenetic Modifiers in Breast Cancer.

Breast cancer is a common cancer that occurs due to different epigenetic alterations and genetic mutations. Various epidemiological studies have demonstrated an inverse correlation between breast cancer incidence and flavonoid intake. The anti-cancer action of flavonoids, a class of polyphenolic compounds that are present in plants, as secondary metabolites has been a major topic of research for many years. Our review analysis demonstrates that flavonoids exhibit anti-cancer activity against breast cancer occurring in different ethnic populations. Breast cancer subtype and menopausal status are the key factors in inducing the flavonoid\u27s anti-cancer action in breast cancer. The dose is another key factor, with research showing that approximately 10 mg/day of isoflavones is required to inhibit breast cancer occurrence. In addition, flavonoids also influence the epigenetic machinery in breast cancer, with research demonstrating that epigallocatechin, genistein, and resveratrol all inhibited DNA methyltransferase and altered chromatin modification in breast cancer. These flavonoids can induce the expression of different tumor suppressor genes that may contribute to decreasing breast cancer progression and metastasis. Additional studies are required to confirm the contribution of epigenetic modifications by flavonoids to breast cancer prevention

Novel targeted siRNA-loaded hybrid nanoparticles: preparation, characterization and in vitro evaluation.

BACKGROUND: siRNAs have a high potential for silencing critical molecular pathways that are pathogenic. Nevertheless, their clinical application has been limited by a lack of effective and safe nanotechnology-based delivery system that allows a controlled and safe transfection to cytosol of targeted cells without the associated adverse effects. Our group recently reported a very effective and safe hybrid nanoparticle delivery system composing human IgG and poloxamer-188 for siRNA delivery to cancer cells. However, these nanoparticles need to be optimized in terms of particle size, loading capacity and encapsulation efficiency. In the present study, we explored the effects of certain production parameters on particle size, loading capacity and encapsulation efficiency. Further, to make these nanoparticles more specific in their delivery of siRNA, we conjugated anti-NTSR1-mAb to the surface of these nanoparticles to target NTSR1-overexpressing cancer cells. The mechanism of siRNA release from these antiNTSR1-mAb functionalized nanoparticles was also elucidated. RESULTS: It was demonstrated that the concentration of human IgG in the starting nanoprecipitation medium and the rotation speed of the magnetic stirrer influenced the encapsulation efficiency, loading capacity and the size of the nanoparticles produced. We also successfully transformed these nanoparticles into actively targeted nanoparticles by functionalizing with anti-NTSR1-mAb to specifically target NTSR1-overexpressing cancer cells, hence able to avoid undesired accumulation in normal cells. The mechanism of siRNA release from these nanoparticles was elucidated to be by Fickian diffusion. Using flow cytometry and fluorescence microscopy, we were able to confirm the active involvement of NTSR1 in the uptake of these anti-NTSR1-mAb functionalized hybrid nanoparticles by lung adenocarcinoma cells. CONCLUSIONS: This hybrid nanoparticle delivery system can be used as a platform technology for intracellular delivery of siRNAs to NTSR1-overexpressing tumor cells

NC2213: a novel methionine aminopeptidase 2 inhibitor in human colon cancer HT29 cells

Methionine aminopeptidase 2 (MetAP2) is a bifunctional protein that plays a critical role in the regulation of post-translational processing and protein synthesis. MetAP2 is overexpressed in human colon cancer. In this report we screened various MetAP2 inhibitors and treated HT29 cells with various concentrations of compounds. We evaluated the expression of MetAP2 and pp60c-src expressions in HT29 cells. In addition we also carried out the cell proliferation and cell cycle analysis in the MetAP2 inhibitor-treated HT29 cells. The cell cycle analysis of HT29 treated with 1.0 μM of NC2213 showed an arrest in the G2 phase followed by an induction in the percentage of cells undergoing apoptosis in the sub-G1 phase. Western blot analysis revealed that the MetAP2 expression was dose-dependently decreased when the HT29 cells were treated with the 3,5-bis(benzylidene)-4-piperidone derivative (NC2213). In addition, phosphorylation of Src, a myristoylated oncoprotein was significantly decreased by 1.0 μM of NC2213 as revealed by Western blot analysis. Furthermore, NC2213 also inhibits the expression of pp60c-src in HT29 cells. Interestingly, this compound also inhibits the phosphorylation at Tyr416 of pp60c-src while increasing the phosphorylation at Tyr527 of pp60c-src. NC2213 inhibits the growth of HT29 cells by inducing apoptosis and might be useful for the treatment of human colon cancer

1-Chromonyl-5-Imidazolylpentadienone Demonstrates Anti-Cancer Action against TNBC and Exhibits Synergism with Paclitaxel

Curcumin has been well studied for its anti-oxidant, anti-inflammatory, and anti-cancer action. Its potential as a therapy is limited due to its low bioavailability and rapid metabolism. To overcome these challenges, investigators are developing curcumin analogs, nanoparticle formulations, and combining curcumin with other compounds or dietary components. In the present study, we used a 1-chromonyl-5-imidazolylpentadienone named KY-20-22 that contains both the pharmacophore of curcumin and 1,4 benzopyrone (chromone) moiety typical for flavonoids, and also included specific moieties to enhance the bioavailability. When we tested the in vitro effect of KY-20-22 in triple-negative breast cancer (TNBC) cell lines, we found that it decreased the cell survival and colony formation of MDA-MB-231 and MDA-MB-468 cells. An increase in mitochondrial reactive oxygen species was also observed in TNBC cells exposed to KY-20-22. Furthermore, KY-20-22 decreased epithelial-mesenchymal formation (EMT) as evidenced by the modulation of the EMT markers E-cadherin and N-cadherin. Based on the fact that KY-20-22 regulates interleukin-6, a cytokine involved in chemotherapy resistance, we combined it with paclitaxel and found that it synergistically induced anti-proliferative action in TNBC cells. The results from this study suggested that 1-chromonyl-5-imidazolylpentadienone KY-20-22 exhibited anti-cancer action in MDA-MB-231 and MDA-MB-468 cells. Future studies are required to evaluate the anti-cancer ability and bioavailability of KY-20-22 in the TNBC animal model

RIZ1 is potential CML tumor suppressor that is down-regulated during disease progression

BACKGROUND: RIZ1 expression and activity are reduced in many cancers. In AML cell lines and patient material, RIZ1 expression is reduced relative to normal bone marrow. In chronic myelogenous leukemia (CML), blastic transformation is associated with loss of heterozygosity in the region where RIZ1 is located. RIZ1 is a PR domain methyltransferase that methylates histone H3 lysine 9, a modification important for transcriptional repression. In CML blast crisis cell lines RIZ1 represses insulin-like growth factor-1 expression and autocrine signaling. Together these observations suggest that RIZ1 may have a role in the chronic phase to blast crisis transition in CML. RESULTS: In CML patient material, we observed that RIZ1 expression was decreased during progression from chronic phase to blast crisis. RIZ1 was expressed in mature myeloid and CD34(+ )cells demonstrating that decreased RIZ1 expression in blast crisis is not due to an increased immature cell population. Expression of RIZ1 CML blast crisis cell lines decreased proliferation, increased apoptosis, and enhanced differentiation. CONCLUSION: RIZ1 is a candidate tumor suppressor gene whose expression is decreased in blast crisis. Loss of RIZ1 activity results in decreased apoptosis and differentiation and enhanced proliferation. Together these results suggest that loss of RIZ1 expression will lead to an increase in myeloid blast cell population resulting in CML progression

Biochemical Characterization of Bovine Brain Myristoyl-CoA:Protein N-Myristoyltransferase Type 2

Protein N-myristoylation is a lipidic modification which refers to the covalent attachment of myristate, a 14-carbon saturated fatty acid, to the N-terminal glycine residue of a number of mammalian, viral, and fungal proteins. In this paper, we have cloned the gene coding for myristoyl-CoA:protein N-myristoyltransferase (NMT) from Bos tarus brain. The open reading frame codes for a 410-amino-acid protein and overexpressed in Escherichia coli. Kinetic studies suggested that bovine brain NMT2 and human NMT1 show significant differences in their peptide substrate specificities. The metal ion Ca2+ had stimulatory effects on NMT2 activity while Mn2+ and Zn2+ inhibited the enzyme activity. In addition, NMT2 activity was inhibited by various organic solvents and other detergents while NMT1 had a stimulatory effect. Biochemical characterization suggested that both forms of NMT have unique characteristics. Further analysis towards functional role NMT2 will lead the development of therapeutic target for the progression of various diseases such as cancer, cardiovascular diseases, and neurodegenerative diseases

A Second-Generation Integrated Map of the Silkworm Reveals Synteny and Conserved Gene Order Between Lepidopteran Insects

A second-generation linkage map was constructed for the silkworm, Bombyx mori, focusing on mapping Bombyx sequences appearing in public nucleotide databases and bacterial artificial chromosome (BAC) contigs. A total of 874 BAC contigs containing 5067 clones (22% of the library) were constructed by PCR-based screening with sequence-tagged sites (STSs) derived from whole-genome shotgun (WGS) sequences. A total of 523 BAC contigs, including 342 independent genes registered in public databases and 85 expressed sequence tags (ESTs), were placed onto the linkage map. We found significant synteny and conserved gene order between B. mori and a nymphalid butterfly, Heliconius melpomene, in four linkage groups (LGs), strongly suggesting that using B. mori as a reference for comparative genomics in Lepidotera is highly feasible