1.Inhibition of DNA Topoisomerase Type IIα (TOP2A) by Mitoxantrone and Its Halogenated Derivatives: A Combined Density Functional and Molecular Docking Study.
Abu Saleh M1, Solayman M1, Hoque MM2, Khan MA3, Sarwar MG4, Halim MA5. Biomed Res Int. 2016;2016:6817502. doi: 10.1155/2016/6817502. Epub 2016 Feb 15.
In this study, mitoxantrone and its halogenated derivatives have been designed by density functional theory (DFT) to explore their structural and thermodynamical properties. The performance of these drugs was also evaluated to inhibit DNA topoisomerase type IIα (TOP2A) by molecular docking calculation. Noncovalent interactions play significant role in improving the performance of halogenated drugs. The combined quantum and molecular mechanics calculations revealed that CF3 containing drug shows better preference in inhibiting the TOP2A compared to other modified drugs.
2.The phytoestrogen genistein enhances multidrug resistance in breast cancer cell lines by translational regulation of ABC transporters.
Rigalli JP1, Tocchetti GN2, Arana MR2, Villanueva SS2, Catania VA2, Theile D3, Ruiz ML2, Weiss J4. Cancer Lett. 2016 Mar 23. pii: S0304-3835(16)30200-2. doi: 10.1016/j.canlet.2016.03.040. [Epub ahead of print]
Breast cancer is the most frequent malignancy in women. Multidrug resistance due to overexpression of ABC drug transporters is a common cause of chemotherapy failure and disease recurrence. Genistein (GNT) is a phytoestrogen present in soybeans and hormone supplements. We investigated the effect of GNT on the expression and function of ABC transporters in MCF-7 and MDA-MB-231 breast cancer cell lines. Results demonstrated an induction at the protein level of ABCC1 and ABCG2 and of ABCC1 in MCF-7 and MDA-MB-231, respectively. MCF-7 cells showed a concomitant increase in doxorubicin and mitoxantrone efflux and resistance, dependent on ABCG2 activity. ABCC1 induction by GNT in MDA-MB-231 cells modified neither drug efflux nor chemoresistance due to simultaneous acute inhibition of the transporter activity by GNT. All inductions took place at the translational level, as no increment in mRNA was observed and protein increase was prevented by cycloheximide.
3.Induction of multixenobiotic defense mechanisms in resistant Daphnia magna clones as a general cellular response to stress.
Jordão R1, Campos B2, Lemos MF3, Soares AM4, Tauler R2, Barata C5. Aquat Toxicol. 2016 Mar 16;175:132-143. doi: 10.1016/j.aquatox.2016.03.015. [Epub ahead of print]
Multixenobiotic resistance mechanisms (MXR) were recently identified in Daphnia magna. Previous results characterized gene transcripts of genes encoding and efflux activities of four putative ABCB1 and ABCC transporters that were chemically induced but showed low specificity against model transporter substrates and inhibitors, thus preventing us from distinguishing between activities of different efflux transporter types. In this study we report on the specificity of induction of ABC transporters and of the stress protein hsp70 in clones selected to be genetically resistant to ABCB1 chemical substrates. Clones resistant to mitoxantrone, ivermectin and pentachlorophenol showed distinctive transcriptional responses of transporter protein coding genes and of putative transporter dye activities. Expression of hsp70 proteins also varied across resistant clones. Clones resistant to mitoxantrone and pentachlorophenol showed high constitutive levels of hsp70.
4.Three-dimensional culture and interaction of cancer cells and dendritic cells in an electrospun nano-submicron hybrid fibrous scaffold.
Kim TE1, Kim CG1, Kim JS2, Jin S2, Yoon S3, Bae HR4, Kim JH5, Jeong YH5, Kwak JY1. Int J Nanomedicine. 2016 Mar 2;11:823-35. doi: 10.2147/IJN.S101846. eCollection 2016.
An artificial three-dimensional (3D) culture system that mimics the tumor microenvironment in vitro is an essential tool for investigating the cross-talk between immune and cancer cells in tumors. In this study, we developed a 3D culture system using an electrospun poly(ε-caprolactone) (PCL) nanofibrous scaffold (NFS). A hybrid NFS containing an uninterrupted network of nano- and submicron-scale fibers (400 nm to 2 µm) was generated by deposition onto a stainless steel mesh instead of an aluminum plate. The hybrid NFS contained multiplanar pores in a 3D structure. Surface-seeded mouse CT26 colon cancer cells and bone marrow-derived dendritic cells (BM-DCs) were able to infiltrate the hybrid NFS within several hours. BM-DCs cultured on PCL nanofibers showed a baseline inactive form, and lipopolysaccharide (LPS)-activated BM-DCs showed increased expression of CD86 and major histocompatibility complex Class II. Actin and phosphorylated FAK were enriched where unstimulated and LPS-stimulated BM-DCs contacted the fibers in the 3D hybrid NFS.