Project description:To identify potential miRNA effectors responsible for anti-tumorigenesis by targeting PLD1, we performed miRNA microarray in Wnt-relevant colon cancer cells and analyzed miRNAs that were differently expressed by inhibition of PLD1
Project description:Mitogen-activated protein kinases (MEK 1/2) are central components of the RAS signaling pathway and attractive targets for cancer therapy. However, PIK3CA mutation, which commonly co-occurs with KRAS mutation, offered resistance to MEK inhibitor through activation of PI3K-AKT signaling. We identified a gene that cooperates with MEK inhibitors to forcefully treat PIK3CA mutant colon cancer cells. -catenin, a key molecule of the WNT pathway, emerged as a candidate by protein/Ab Chip array. MEK inhibitor treatment led to a decrease in -catenin in PIK3CA wild-type colon cancer cells but not in PIK3CA mutant colon cancer cells. Tumor regression was promoted by a combination of MEK inhibitor and NVP-TNS656, which targets the WNT pathway. Furthermore, combined inhibition of MEK and -catenin by NVP-TNS656 promoted tumor regression in colon cancer patient-derived xenograft (PDX) models expressing mutant PIK3CA. Taken together, we propose that inhibition of the WNT pathway, particularly -catenin, may bypass resistance to MEK inhibitor in human PIK3CA mutant colon cancer. Additionally, -catenin is a potential PD marker of MEK inhibitor resistance. In the study, we identified and evaluated biomarker for response to MEK inhibitor on colon cancer cells.
Project description:We have compared the genome-wide effects on the transcriptome after treatment with ICG-001 (the specific CBP inhibitor) versus C646, a compound that competes with acetyl-coA for the Lys-coA binding pocket of both CBP and p300. We found that both drugs cause large-scale changes in the transcriptome of HCT116 colon cancer cells and PANC1 pancreatic cancer cells, and reverse some tumor-specific changes in gene expression. Interestingly, although the epigenetic inhibitors affect cell cycle pathways in both the colon and pancreatic cancer cell lines, the WNT signaling pathway was affected only in the colon cancer cells. Notably, WNT target genes were similarly down-regulated after treatment of HCT116 with C646 as with ICG-001. To identify genes affected by direct targeting of a component of the transcriptional complex implicated in WNT regulation, we used siRNAs to knockdown TCF7L2 in PANC1 cells. Cells were treated with control siRNAs or siRNAs specific for TCF7L2 and RNA was analyzed by RNA-seq.
Project description:Wnt/b-catenin pathway is a key modulator of intestinal homeostasis by regulating stem cell biology during gut organogenesis and in adult life. DICKKOPF (DKK)-1 is a secreted inhibitor of Wnt/b-catenin signaling from plasma membrane receptors. We found that in human intestine, DKK-1 locates within the nucleus of differentiated enterocytes and enteroendocrine cells but not of proliferating and stem cells at the bottom of the crypts. DKK-1 is also nuclear in colon cancer cells locating at sites of active gene transcription. ChIP-seq and transcriptomic analysis both confirmed that DKK-1 binds chromatin and regulates gene expression. Thus, we demonstrate that DKK-1 is a multifunctional protein that inhibits Wnt/b-catenin signaling at plasma membrane and controls specific genes in the nucleus, suggesting that these functions are relevant for intestinal homeostasis. Analysis of DKK-1 location and associated roles in human colon cancer cells and crypts of small and large bowel.
Project description:Mitogen-activated protein kinases (MEK 1/2) are central components of the RAS signaling pathway and attractive targets for cancer therapy. However, PIK3CA mutation, which commonly co-occurs with KRAS mutation, offered resistance to MEK inhibitor through activation of PI3K-AKT signaling. We identified a gene that cooperates with MEK inhibitors to forcefully treat PIK3CA mutant colon cancer cells. -catenin, a key molecule of the WNT pathway, emerged as a candidate by protein/Ab Chip array. MEK inhibitor treatment led to a decrease in -catenin in PIK3CA wild-type colon cancer cells but not in PIK3CA mutant colon cancer cells. Tumor regression was promoted by a combination of MEK inhibitor and NVP-TNS656, which targets the WNT pathway. Furthermore, combined inhibition of MEK and -catenin by NVP-TNS656 promoted tumor regression in colon cancer patient-derived xenograft (PDX) models expressing mutant PIK3CA. Taken together, we propose that inhibition of the WNT pathway, particularly -catenin, may bypass resistance to MEK inhibitor in human PIK3CA mutant colon cancer. Additionally, -catenin is a potential PD marker of MEK inhibitor resistance.
Project description:Colon cancers typically contain tumor cell populations with differential WNT signaling activity. Colon cancer cells with high WNT-activity have been attributed increase tumorigenic potential and stem cell characteristics. We extracted tumor cells with differential WNT activity using fluorescent reporters from xenografted human colon cancer cell line tumors and primary human colon cancer xenografts and analysed their gene expression profiles.
Project description:We have compared the genome-wide effects on the transcriptome after treatment with ICG-001 (the specific CBP inhibitor) versus C646, a compound that competes with acetyl-coA for the Lys-coA binding pocket of both CBP and p300. We found that both drugs cause large-scale changes in the transcriptome of HCT116 colon cancer cells and PANC1 pancreatic cancer cells, and reverse some tumor-specific changes in gene expression. Interestingly, although the epigenetic inhibitors affect cell cycle pathways in both the colon and pancreatic cancer cell lines, the WNT signaling pathway was affected only in the colon cancer cells. Notably, WNT target genes were similarly down-regulated after treatment of HCT116 with C646 as with ICG-001.
Project description:We have compared the genome-wide effects on the transcriptome after treatment with ICG-001 (the specific CBP inhibitor) versus C646, a compound that competes with acetyl-coA for the Lys-coA binding pocket of both CBP and p300. We found that both drugs cause large-scale changes in the transcriptome of HCT116 colon cancer cells and PANC1 pancreatic cancer cells, and reverse some tumor-specific changes in gene expression. Interestingly, although the epigenetic inhibitors affect cell cycle pathways in both the colon and pancreatic cancer cell lines, the WNT signaling pathway was affected only in the colon cancer cells. Notably, WNT target genes were similarly down-regulated after treatment of HCT116 with C646 as with ICG-001.
Project description:We have compared the genome-wide effects on the transcriptome after treatment with ICG-001 (the specific CBP inhibitor) versus C646, a compound that competes with acetyl-coA for the Lys-coA binding pocket of both CBP and p300. We found that both drugs cause large-scale changes in the transcriptome of HCT116 colon cancer cells and PANC1 pancreatic cancer cells, and reverse some tumor-specific changes in gene expression. Interestingly, although the epigenetic inhibitors affect cell cycle pathways in both the colon and pancreatic cancer cell lines, the WNT signaling pathway was affected only in the colon cancer cells. Notably, WNT target genes were similarly down-regulated after treatment of HCT116 with C646 as with ICG-001. Total RNA obtained from isolated HCT116 or PANC1 cell lines were treated with 10uM ICG-001, 10uM C646, or 0.05% DMSO and collected after 12 or 96 hours.