Project description:Achaete scute-like 2 (Ascl2), a basic helix-loop-helix (bHLH) transcription factor, controls the fate of intestinal stem cells. However, the role of Ascl2 in colon cancer progenitor cells remains unknown. The cell lines HT-29 (47.5-95% of CD133+ population) and LS174T (0.45% of CD133+ population) were chosen for functional evaluation of Ascl2 in colon cancer progenitor cells after gene knockdown by RNA interference. The microRNA (miRNA) microarrays identified 26 two-fold up-regulated miRNAs and 58 two-fold down-regulated miRNAs in shRNA-Ascl2/HT-29 cells and 178 two-fold up-regulated miRNAs and 172 two-fold down-regulated miRNAs in shRNA-Ascl2/LS174T cells. Two-condition experiment: shRNA-Ascl2/HT-29 cells vs. shRNA-Ctr/HT-29 cells, and shRNA-Ascl2/LS174T cells vs. shRNA-Ctr/LS174T cells. Biological replicates: 1 HT-29 cells stably transfected with shRNA-Ascl2/EGFP, 1 LS174T cells stably transfected with shRNA-Ascl2/EGFP, 1 HT-29 cells stably transfected with shRNA-Control/EGFP, and 1 LS174T cells stably transfected with shRNA-Control/EGFP, independently grown and harvested. One replicate per array.
Project description:Achaete scute-like 2 (Ascl2), a basic helix-loop-helix (bHLH) transcription factor, controls the fate of intestinal stem cells. However, the role of Ascl2 in colon cancer progenitor cells remains unknown. The cell lines HT-29 (47.5-95% of CD133+ population) and LS174T (0.45% of CD133+ population) were chosen for functional evaluation of Ascl2 in colon cancer progenitor cells after gene knockdown by RNA interference. The microRNA (miRNA) microarrays identified 26 two-fold up-regulated miRNAs and 58 two-fold down-regulated miRNAs in shRNA-Ascl2/HT-29 cells and 178 two-fold up-regulated miRNAs and 172 two-fold down-regulated miRNAs in shRNA-Ascl2/LS174T cells.
Project description:Metastasis and drug-resistance are major problems in cancer chemotherapy. The purpose of this work was to analyze the molecular mechanisms underlying the invasive potential of drug-resistant colon carcinoma cells. Cellular models included the parental HT-29 cell line and its drug-resistant derivatives selected after chronic treatment with either 5-fluorouracil (5-FU), methotrexate (MTX), doxorubicin (DOX) or oxaliplatin (OXA). Drug-resistant invasive cells were compared to non invasive cells using cDNA microarray, qRT-PCR, flow cytometry, immunoblots and ELISA. Functional and cellular signaling analyses were undertaken using pharmacological inhibitors, function-blocking antibodies, and silencing by retrovirus-mediated RNA interference. 5-FU- and MTX-resistant HT-29 cells expressing an invasive phenotype in collagen type I and a metastatic behaviour in immunodeficient mice exhibited high expression of the chemokine receptor CXCR4. Macrophage migration inhibitory factor (MIF) was identified as the critical autocrine CXCR4 ligand promoting invasion in drug-resistant colon carcinoma HT-29 cells. Silencing of CXCR4 and impairing the MIF-CXCR4 signaling pathways by ISO-1, pAb FL-115, AMD-3100, mAb 12G5, and BIM-46187 abolished this aggressive phenotype. Induction of CXCR4 is associated with up-regulation of two genes encoding transcription factors previously shown to control CXCR4 expression (HIF-2a and ASCL2) and maintenance of intestinal stem cells (ASCL2). Enhanced CXCR4 expression was detected in liver metastases resected from colon cancer patients treated by the standard FOLFOX regimen. Combination therapies targeting the CXCR4-MIF axis can potentially counteract the emergence of the invasive metastatic behaviour in clonal derivatives of drug-resistant colon cancer cells. Samples: HT-29 cell clones were obtained by limiting dilution from HT-29 subpopulations resistant to methothrexate (HT-29 5M21 cell clone) and or to 5-Fluoro-uracil (HT-29 5F7 and HT-29 5F31). Samples were provided by Dr. T Lesuffleur. Xenografts: HT-29 5M21, HT-29 5F7, and HT-29 5F31 xenografts were obtained by a first subcutaneous inoculation of cells in Nude mice and then fragments of subcutaneous tumors were reimplantated in SCID mice. First experiment of microarrays: HT-29 5M21 and HT-29 5F7 cells (that are invasive in in vitro assays on type I collagen) were compared to HT-29 5F31 cells (that are not invasive in vitro on type I collagen). Samples were co-hybridized on Agilent Human 44K GEP arrays (respectively 5F31 vs 5M21, 5F31 vs 5F7, 5M21 vs 5F31 and 5F7 vs 5F31). Second experiment of microarrays: HT-29 5M21 and HT-29 5F7 xenografts (that develop metastases in immuno-deficient mice lungs) were compared to HT-29 5F31 xenografts (that do not develop metastases in immuno-deficient mice lungs). Samples were consequently co-hybridized on human and mouse 4x44K GEP arrays (respectively AG41_5F31-5M21-138869, AG39_5F31-5F7-138867, AG42_5M21-5F31-138870 and AG40_5F7-5F31-138868 for human microarrays; 5M21_5F31_27033_4, 5F31_5M21_27033_3, 5F7_5F31_27033_2 and 5F31_5F7_27033_1_1 for mouse microarrays).
Project description:This study is to identify downstream targets of homeobox gene CDX1. The study assayed the expression of 2 pairs of stably transfected colorectal cancer cell lines: The CDX1 nonexpressing CRC cell line HCT116 was stably transfected with either CDX1 cDNA in the pRC/CMV expression vector (HCT116-CDX1) or with vector control (HCT116-Vec). The CDX1-expressing CRC cell line LS174T was similarly transfected with either a pSilencer vector containing a short sequence of CDX1 siRNA (LS174T-siRNA) , or a pSilencer vector containing a scrambled siRNA sequence as a control (LS174T-Vec).
Project description:Transcriptional profiling of HT-29 human colon cancer cells transfected with non-targeting control (NTC) siRNA and two different siRNA sequences against CDK8 (siCDK8-1 and siCDK8-2).
Project description:Metastasis and drug-resistance are major problems in cancer chemotherapy. The purpose of this work was to analyze the molecular mechanisms underlying the invasive potential of drug-resistant colon carcinoma cells. Cellular models included the parental HT-29 cell line and its drug-resistant derivatives selected after chronic treatment with either 5-fluorouracil (5-FU), methotrexate (MTX), doxorubicin (DOX) or oxaliplatin (OXA). Drug-resistant invasive cells were compared to non invasive cells using cDNA microarray, qRT-PCR, flow cytometry, immunoblots and ELISA. Functional and cellular signaling analyses were undertaken using pharmacological inhibitors, function-blocking antibodies, and silencing by retrovirus-mediated RNA interference. 5-FU- and MTX-resistant HT-29 cells expressing an invasive phenotype in collagen type I and a metastatic behaviour in immunodeficient mice exhibited high expression of the chemokine receptor CXCR4. Macrophage migration inhibitory factor (MIF) was identified as the critical autocrine CXCR4 ligand promoting invasion in drug-resistant colon carcinoma HT-29 cells. Silencing of CXCR4 and impairing the MIF-CXCR4 signaling pathways by ISO-1, pAb FL-115, AMD-3100, mAb 12G5, and BIM-46187 abolished this aggressive phenotype. Induction of CXCR4 is associated with up-regulation of two genes encoding transcription factors previously shown to control CXCR4 expression (HIF-2a and ASCL2) and maintenance of intestinal stem cells (ASCL2). Enhanced CXCR4 expression was detected in liver metastases resected from colon cancer patients treated by the standard FOLFOX regimen. Combination therapies targeting the CXCR4-MIF axis can potentially counteract the emergence of the invasive metastatic behaviour in clonal derivatives of drug-resistant colon cancer cells.
Project description:To investigate the role of TGF-M-NM-21-regulated miRNAs in the progression of colorectal cancer,we performed comprehensive miRMA microarray analysis on RNA derived from typical human colorectal cancer cell lines and TGF-M-NM-21 knock-down human colorectal cancer cell lines. We identified a novel set of TGF-M-NM-21-related miRNAs. Total RNA was isolated from TGF-M-NM-21-knock down colorecatl cancer cell lines and controls.Three-condition experiment: shRNA-TGF-M-NM-21/Lovo cells vs. shRNA-Control/Lovo cells, shRNA-TGF-M-NM-21/SW620 cells vs. shRNA-Control/ SW620 cells, and shRNA-TGF-M-NM-21/HT29 cells vs. shRNA-Control/HT29 cells. Biological replicates: 1 Lovo cells stably transfected with shRNA-TGF-M-NM-21- pSUPER gfp-neo, 1SW620 cells stably transfected with shRNA-TGF-M-NM-21- pSUPER gfp-neo, 1HT29 cells stably transfected with shRNA-TGF-M-NM-21- pSUPER gfp-neo, 1Love cells stably transfected with shRNA-Control- pSUPER gfp-neo, 1SW620 cells stably transfected with shRNA-Control- pSUPER gfp-neo, and 1HT29 cells stably transfected with shRNA-Control- pSUPER gfp-neo, independently grown and harvested. One replicate per array.
Project description:To investigate the role of TGF-M-NM-21-regulated miRNAs in the progression of RMS,we performed comprehensive miRMA microarray analysis on RNA derived from typical RMS cell lines and TGF-M-NM-21 knock-down cell lines. We identified a novel set of TGF-M-NM-21-related miRNAs. Total RNA was isolated from TGF-M-NM-21-knock down rhabdmyosarcoma cell lines and controls. Three-condition experiment: shRNA-TGF-M-NM-21/RD cells vs. shRNA-Control/RD cells, shRNA-TGF-M-NM-21/SMS-CTR cells vs. shRNA-Control/ SMS-CTR cells, and shRNA-TGF-M-NM-21/RH28 cells vs. shRNA-Control/RH28 cells. Biological replicates: 1 RD cells stably transfected with shRNA-TGF-M-NM-21- pSUPER gfp-neo, 1SMS-CTR cells stably transfected with shRNA-TGF-M-NM-21- pSUPER gfp-neo, 1RH28 cells stably transfected with shRNA-TGF-M-NM-21- pSUPER gfp-neo, 1RD cells stably transfected with shRNA-Control- pSUPER gfp-neo, 1SMS-CTR cells stably transfected with shRNA-Control- pSUPER gfp-neo, and 1RH28 cells stably transfected with shRNA-Control- pSUPER gfp-neo, independently grown and harvested. One replicate per array.
Project description:Wnt signaling plays a pivotal role in colorectal cancer. Intrinsic activation of Wnt by mutational events, such as mutations in the tumor suppressor gene APC, represents the most frequent initiating event in this disease background. Long truncated versions of APC retain partial functionality, which leads to a sub-maximal, “just right” activation state of Wnt signaling supposed to be beneficial for disease initiation. In order to study the transcriptomic alterations of an over-stimulated Wnt signaling pathway, conditional shRNA-mediated silencing of APC was performed in chromosomal instable HT-29 CRC cells which express a 1555 amino acid variant of APC protein able to bind and partially inactivate β-catenin. To achieve this, cells were stably transduced with lentiviral particles encoding for a doxycyline-inducible shRNA directed against APC, or, as a control, a non-silencing shRNA (pTRIPZ inducible shRNA vectors, RHS4740-EG324, Horizon Dharmacon, CO, USA). 72 hours after APC silencing, total RNA was isolated and quality controlled for subsequent RNA-Seq Analysis (DKFZ Heidelberg, Genomic and Proteomic Core Facility) on a HiSeq 2000 instrument (Illumina). Overall, we observed bona-fide Wnt target genes, such as NKD1, AXIN2, PTK7, ASCL2, and SMOC2, and additional putative direct or indirect targets of Wnt signaling up-regulated upon shRNA-mediated APC silencing.
Project description:This study is to identify downstream targets of homeobox gene CDX1. The study assayed the expression of 2 pairs of stably transfected colorectal cancer cell lines: The CDX1 nonexpressing CRC cell line HCT116 was stably transfected with either CDX1 cDNA in the pRC/CMV expression vector (HCT116-CDX1) or with vector control (HCT116-Vec). The CDX1-expressing CRC cell line LS174T was similarly transfected with either a pSilencer vector containing a short sequence of CDX1 siRNA (LS174T-siRNA) , or a pSilencer vector containing a scrambled siRNA sequence as a control (LS174T-Vec). Experiment Overall Design: 2 pairs of colorectal cancer cell lines were used for comparison