Jin Li,Zi-Hui Wang,Ya-Min Dang,Dan-Ni Li,Zhen Liu,Da-Peng Dai,Jian-Ping Cai
MTH1 protein can sanitize the damaged (d)NTP pool and MTH1 inhibitors have been developed to impede the growth of rapidly proliferating tumor cells; however, the effect of MTH1 inhibition on breast cancer stemness has not been reported yet. Here, we constructed breast cancer cell lines with the stable depletion of MTH1. MTH1 suppression clearly increased the ratio of CD44 + CD24 −/low subpopulations and promoted the formation of tumorspheres in MCF7 and T47D cells. RNA expression profiling, RT–qPCR and Western blotting showed the upregulation of master stem cell transcription factors Sox2 , Oct4 and Nanog in MTH1 knockdown cells. GSEA suggested and Western blotting verified that MTH1 knockdown increased the expression of phosphorylated STAT3 (Tyr705). Furthermore, we indirectly demonstrated that the increased concentration of 8-oxo-dGTP and 8-oxo-GTP in MTH1 -knockdown cells and exogenous 8-oxoGTP, rather than 8-oxo-dGTP, could significantly increase the phosphorylation of STAT3. In conclusion, this work indicates that MTH1 inhibition increased the proportion of breast cancer stem cells (BCSCs) and promoted stemness properties in MCF7 cells.
Xinxin Ren,Qingqing Zhang,Lingxia Qin,Kaiyue Hu,Zhiyong Guo,Sui Wang,Yufang Hu
In this study, a checkerboard arranged G4 nanostructure-supported electrochemical platform is developed well for the application to unique bio-enzymes examination. Herein, we focus on the two bio-enzymes involving histone acetyltransferase (HAT) and terminal deoxynucleotidyl transferase (TdT); the former leads to the acetyl transfer of acetyl coenzyme A to the lysine residue of the substrate peptide and the latter achieves the polymeric extension of DNA without template under a unique pool of dATP and dGTP (4: 6). A complex of antibody and short DNA is introduced onto the electrode surface based on the affinity interaction between acetyl in acetylated peptide and its antibody. and used for initiating reaction. Then, TdT-yielded rich-G sequence is formed to act as the backbone of checkerboard, and subsequently free G-DNAs can be stacked continually on the backbone under Mg 2+ . An excellent electrocatalytic signal to H 2 O 2 emerges noticeably, which is related with the activity of HAT p300 and TdT with a low detection limit of 2.3 pM and 0.38 mU/mL, respectively. Finally, this strategy is also used successfully for the inhibitor screening and complex sample analysis, which has important implications for the advancement of HAT- and TdT-related electrochemical bioassay and drug discovery.
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