Project description:Total mRNA seq was perfomed on human fetal gut tissue at CS22 on 3 samples having different RET haplotype which progressively reduce expression of RET. R haplotypes are resistant and S haplotypes are susceptible to Hirschsprung disease
Project description:To obtain a PTC cell model, primary human thyrocytes have been infected with a retrovirus expressing RET/PTC1 oncogene, using parental thyrocytes as control. The obtained RET/PTC-dependent differential miRNA expression profile, representing the effects of RET/PTC1 oncogene present in about one third of papillary thyroid carcinoma (PTC), models the early event of thyrocytes transformation ending to PTC. miRNA expression profiles of thyrocytes expressing RET/PTC1 oncogene and parental thyrocytes were compared. Biological replicates could not be generated.
Project description:To obtain a PTC cell model, primary human thyrocytes have been infected with a retrovirus expressing RET/PTC1 oncogene, using parental thyrocytes as control. The obtained RET/PTC-dependent differential miRNA expression profile, representing the effects of RET/PTC1 oncogene present in about one third of papillary thyroid carcinoma (PTC), models the early event of thyrocytes transformation ending to PTC.
Project description:Myeloproliferative neoplasms are frequently associated with aberrant constitutive tyrosine kinase (TK) activity resulting from point mutations or chimaeric fusion genes, such as BCR ABL1 or JAK2 V617F. We report here for the first time in hematological malignancies, two novel fusion genes involving the TK RET, BCR-RET and FGFR1OP-RET, in chronic myelo monocytic leukemia (CMML) cases. The two RET fusion genes lead to the aberrant activation of RET, are able to transform hematopoietic cells and skew the hematopoietic differentiation program towards the monocytic/macrophage lineage. We also report that the BCR-RET fusion protein is insensitive to Imatinib but sensitive to Sorafenib in vivo. CMML is an hematopoietic malignancy associated with the frequent activation of the RAS pathway. The RET fusion genes seems to constitutively mimic the same signaling pathway than RAS mutations. Overall, the RET fusion genes behaviors in the monocytic lineage underlie the role of the normal RET TK activity during the physiological monocytic differentiation. We analysed BAF/3 cells infected by BCR-RET, FGFR1OP-RET or BCR-ABL1P210 fusion genes retroviruses and sorted out using EGFP fluorescence, with Affymetrix GeneChip MouseGene 1.0 ST platform.
Project description:Myeloproliferative neoplasms are frequently associated with aberrant constitutive tyrosine kinase (TK) activity resulting from point mutations or chimaeric fusion genes, such as BCR ABL1 or JAK2 V617F. We report here for the first time in hematological malignancies, two novel fusion genes involving the TK RET, BCR-RET and FGFR1OP-RET, in chronic myelo monocytic leukemia (CMML) cases. The two RET fusion genes lead to the aberrant activation of RET, are able to transform hematopoietic cells and skew the hematopoietic differentiation program towards the monocytic/macrophage lineage. We also report that the BCR-RET fusion protein is insensitive to Imatinib but sensitive to Sorafenib in vivo. CMML is an hematopoietic malignancy associated with the frequent activation of the RAS pathway. The RET fusion genes seems to constitutively mimic the same signaling pathway than RAS mutations. Overall, the RET fusion genes behaviors in the monocytic lineage underlie the role of the normal RET TK activity during the physiological monocytic differentiation.
Project description:Genomic rearrangements leading to intragenic gene fusion are mainly found in some types of haematopoietic malignancies and sarcomas. Recently they have been described also in carcinomas such as the papillary thyroid histotype (60%-70%) and the Hürthle thyroid tumours (58%). The presence of junction oncogene constitutes an area of exciting research for emerging therapy as targeting the RET-PTC1 fusion oncogene by using small interfering RNA (siRNA) strategies since it is present only in the tumour cells and not in the surrounding normal cells. Therefore, we developed a siRNA against RET-PTC1 junction and assess its efficiency on the human papillary thyroid carcinoma cell line TPC-1 which spontaneously harbours the RET-PTC1 oncogene. The targeted genes are assessed by microarray analysis by comparing the regulated genes by the siRNA_RET-PTC1 vs a siRNA_RET developed on the RET part of the mRNA minus the siRNA_control that contain four mutation within the RET-PTC1 sequence. To test the targeted genes in the TPC-1 cell line that spontaneously harbours RET-PTC1 junction of two siRNAs developed: Within the RET-PTC1 junction, and in the mRNA RET part. A non-specific siRNA harbouring 4 mutations within the RET-PTC1 sequence was used as negative control (siRNA_control). By real-time PCR (Q-RT-PCR) we demonstrated that both siRNAs (siRNA_RET-PTC1 and siRNA_RET) significantly reduce RET mRNA levels of about 85 % in TPC-1 cells. The negative control did not show an effect of RET mRNA levels. Three independent transfections were performed on TPC-1 cells using 5 µl of Lipofectamine 2000 transfection reagent (Invitrogen, Cergy-Pontoise, France) and 50nM of i) siRNA_RET-PTC1 or ii) siRNA_RET or iii) siRNA_control that harbour 4 mutations within its sequence. Total RNAs of untreated cells and transfected cells were purified using the RNA cleanup and concentration kit (QIAGEN, Hilden, Germany) and gathered in 4 pools : 1) TPC-1 harbouring RET-PTC1 ; 2) TPC-1 silenced for RET-PTC1 with siRNA RET-PTC1 ; 3) TPC-1 silenced for siRNA RET ; 4) TPC-1 treated with the siRNA control.
Project description:Aberrant activation of Anaplastic Lymphoma Kinase (ALK) drives neuroblastoma (NB). Previous work has identified the RET receptor tyrosine kinase (RTK) as a downstream target of ALK activity in NB models. We show here that ALK activation in response to ALKAL2 ligand results in the rapid phosphorylation of RET in NB cells, providing additional insight into the contribution of RET to the ALK driven gene signature in NB. To further address the role of RET in NB, RET knock-out (KO) SK-N-AS cells were generated by CRISPR/Cas9 genome engineering. Gene expression analysis of RET KO NB cells identified a reprogramming of NB cells to a mesenchymal (MES) phenotype that was characterized by increased migration and upregulation of the AXL and MET RTKs as well as integrins and extracellular matrix components. Strikingly, the upregulation of AXL in the absence of RET reflects the development timeline observed in the neural crest as progenitor cells undergo differentiation during embryonic development. Together, these findings suggest that a MES phenotype is promoted in mesenchymal NB cells in the absence of RET, reflective of a less differentiated developmental status.
Project description:Increased treatment of metastatic castration resistant prostate cancer (mCRPC) with second-generation anti-androgen therapies (ADT) has coincided with a greater incidence of lethal, aggressive variant prostate cancer (AVPC) tumors that have lost androgen receptor (AR) signaling. AVPC tumors may also express neuroendocrine markers, termed neuroendocrine prostate cancer (NEPC). Recent evidence suggests kinase signaling may be an important driver of NEPC. To identify targetable kinases in NEPC, we performed global phosphoproteomics comparing AR-negative to AR-positive prostate cancer cell lines and identified multiple altered signaling pathways, including enrichment of RET kinase activity in the AR-negative cell lines. Clinical NEPC and NEPC patient derived xenografts displayed upregulated RET transcript and RET pathway activity. Pharmacologically inhibiting RET kinase in NEPC models dramatically reduced tumor growth and cell viability in mouse and human NEPC models. Our results suggest that targeting RET in NEPC tumors with high RET expression may be a novel treatment option.
Project description:Increased treatment of metastatic castration resistant prostate cancer (mCRPC) with second-generation anti-androgen therapies (ADT) has coincided with a greater incidence of lethal, aggressive variant prostate cancer (AVPC) tumors that have lost androgen receptor (AR) signaling. AVPC tumors may also express neuroendocrine markers, termed neuroendocrine prostate cancer (NEPC). Recent evidence suggests kinase signaling may be an important driver of NEPC. To identify targetable kinases in NEPC, we performed global phosphoproteomics comparing AR-negative to AR-positive prostate cancer cell lines and identified multiple altered signaling pathways, including enrichment of RET kinase activity in the AR-negative cell lines. Clinical NEPC and NEPC patient derived xenografts displayed upregulated RET transcript and RET pathway activity. Pharmacologically inhibiting RET kinase in NEPC models dramatically reduced tumor growth and cell viability in mouse and human NEPC models. Our results suggest that targeting RET in NEPC tumors with high RET expression may be a novel treatment option.