Project description:Total RNA (100 μg) were denatured at 70 °C for 5 min and separated by a 15% TBE-Urea gel with 20/100 or 10/60 oligo length standard ladder (Integrated DNA Technologies, Coralville, IA). After visualized by SYBR Gold (Ref. S11494 from Life Technologies), tRFs (15~50 nt) in gels were cut according to sizes and recovered by small RNA PAGE recovery kit (Zymo Research, Irvine, CA, USA). The recovered tRFs was used to establish the library by NEB small RNA library preparation kit (E7330S).
Project description:Total RNA (100 μg) were denatured at 70 °C for 5 min and separated by a 15% TBE-Urea gel with 20/100 or 10/60 oligo length standard ladder (Integrated DNA Technologies, Coralville, IA). After visualized by SYBR Gold (Ref. S11494 from Life Technologies), tRFs (15~50 nt) in gels were cut according to sizes and recovered by small RNA PAGE recovery kit (Zymo Research, Irvine, CA, USA). The recovered tRFs was used to establish the library by NEB small RNA library preparation kit (E7330S).
Project description:Background: The oxidative DNA demethylase ALKBH3 targets single-stranded DNA (ssDNA) in order to perform DNA alkylation damage repair. ALKBH3 becomes up-regulated during tumorigenesis and is necessary for proliferation. However, the underlying molecular mechanism remains to be understood. Methods: To further elucidate the function of ALKBH3 in cancer, we performed ChIP-seq to investigate the genomic binding pattern of endogenous ALKBH3 in PC3 prostate cancer cells coupled with microarray experiments to examine the expression effects of ALKBH3 depletion. Results: We demonstrate that ALKBH3 binds to transcription associated locations, such as places of promoter-proximal paused RNA polymerase II and enhancers. Strikingly, ALKBH3 strongly binds to the transcription initiation sites of a small number of highly active gene promoters. These promoters are characterized by high levels of transcriptional regulators, including transcription factors, the Mediator complex, cohesin, histone modifiers and active histone marks. Gene expression analysis showed that ALKBH3 does not directly influence the transcription of its target genes, but its depletion induces an up-regulation of ALKBH3 non-bound inflammatory genes. Conclusions: The genomic binding pattern of ALKBH3 revealed a putative novel hyperactive promoter type. Further, we propose that ALKBH3 is an intrinsic DNA repair protein that suppresses transcription associated DNA damage at highly expressed genes and thereby plays a role to maintain genomic integrity in ALKBH3-overexpressing cancer cells. These results raise the possibility that ALKBH3 may be a potential target for inhibiting cancer progression. PC3 cells were infected with ALKBH3 shRNA or Control shRNA for 48 hours and selected with puromycine. Cells were collected after 48h or 96h past selection.
Project description:In order to identify the effects of TFEB overexpression on the hela cells transcriptome, we performed Affymetrix Gene-Chip hybridization experiments for the hela TFEB stable clones Transcriptome analysis of hela stable clones overexpressing TFEB-3xFLAG
Project description:In order to identify the effects of TFEB overexpression on the hela cells transcriptome, we performed Affymetrix Gene-Chip hybridization experiments for the hela TFEB stable clones Transcriptome analysis of hela stable clones overexpressing TFEB-GFP
Project description:The CLIP procedures were conducted using HeLa cells according to the previous study (Liu et al., 2016) with slight modifications. Briefly, 4 plates of HeLa cells in 15 cm dishes were transfected with pPB/ALKBH3 plasmid for 48 h to reach about 90% cell confluency. After washing twice with ice-cold PBS, cells were irradiated twice with 400 mJ/cm2 at 254 nm by Stratalinker on ice. Cells were lysed in high salt lysis buffer (300 mM NaCl, 0.2% NP-40, 20 mM Tris-HCl PH 7.6, 0.5 mM DTT, protease inhibitor cocktail (1 tablet/50 ml), and RNase inhibitor (1:200)) at 4°C for 30 min. Supernatant was collected after centrifuged at 17,000 g at 4°C for 15 min and further treated with 1 U RNase T1 for 15 min at 24 °C. After centrifugation and filtration through 0.22 µM filter, 10% supernatant was collected as input for further sequencing analysis. Anti-Flag M2 beads (Sigma-Aldrich, St. Louis, MO, 80 μl) were washed three times with lysis buffer and incubated with the filtered supernatant at 4°C for 4 hrs. After removing the flow through by magnetic rack, beads and input were further incubated with 10 U RNase T1 exactly for 8 min. Samples were treated with 95 µL commercial PNK buffer and 0.5 U PNK for 15 min at 37 °C. After treatments, final concentration of 100 µM ATP and 1 U PNK were added and incubated at 37 °C for another 30 min. The RNA/protein complexes were eluted by NuPAGE 1 × loading buffer and fractionated by neutral NuPAGE 4–12% bis-tris gel. After cutting the gel, RNAs were recovered by proteinase K digestion in proteinase K buffer, followed by phenol/chloroform extraction using glycogen as carrier. The RNA fragments were ligated to adapter and established library by NEB small RNA library preparation kit (E7330S).
Project description:Background: The oxidative DNA demethylase ALKBH3 targets single-stranded DNA (ssDNA) in order to perform DNA alkylation damage repair. ALKBH3 becomes up-regulated during tumorigenesis and is necessary for proliferation. However, the underlying molecular mechanism remains to be understood. Methods: To further elucidate the function of ALKBH3 in cancer, we performed ChIP-seq to investigate the genomic binding pattern of endogenous ALKBH3 in PC3 prostate cancer cells coupled with microarray experiments to examine the expression effects of ALKBH3 depletion. Results: We demonstrate that ALKBH3 binds to transcription associated locations, such as places of promoter-proximal paused RNA polymerase II and enhancers. Strikingly, ALKBH3 strongly binds to the transcription initiation sites of a small number of highly active gene promoters. These promoters are characterized by high levels of transcriptional regulators, including transcription factors, the Mediator complex, cohesin, histone modifiers and active histone marks. Gene expression analysis showed that ALKBH3 does not directly influence the transcription of its target genes, but its depletion induces an up-regulation of ALKBH3 non-bound inflammatory genes. Conclusions: The genomic binding pattern of ALKBH3 revealed a putative novel hyperactive promoter type. Further, we propose that ALKBH3 is an intrinsic DNA repair protein that suppresses transcription associated DNA damage at highly expressed genes and thereby plays a role to maintain genomic integrity in ALKBH3-overexpressing cancer cells. These results raise the possibility that ALKBH3 may be a potential target for inhibiting cancer progression.