Project description:Tyrosine kinase inhibitors (TKIs) targeting the BCR-ABL1 fusion tyrosine kinase have revolutionized the treatment of chronic myeloid leukemia (CML). However, the development of TKI resistance and the subsequent transition from the chronic phase (CP) to blast crisis (BC) threaten CML patients. Accumulating evidence suggests that translational control is crucial for cancer development and progression. Here, we performed high throughput CRISPR/Cas9 screening and identified poly(A) binding protein cytoplasmic 1 (PABPC1) as a driver for CML-BC progression. PABPC1 preferentially improved the translation efficiency of multiple leukemogenic mRNAs with long and highly structured 5' untranslated regions, including BCR-ABL1 and its TKI-resistant mutants, through forming biomolecular condensates. Inhibiting PABPC1 significantly suppressed CML cell proliferation and attenuated disease progression, but did not affect normal hematopoiesis seriously. More importantly, we identified two novel PABPC1 inhibitors, 1,10-Phen and ML324, which inhibited BC progression and overcame TKI resistance in murine and human CML. Overall, our work identified PABPC1 as a selective translation enhancing factor in CML-BC, the genetic or pharmacological inhibition of which overcame TKI resistance and suppressed BC progression in CML.
Project description:Tyrosine kinase inhibitors (TKIs) targeting the BCR-ABL1 fusion tyrosine kinase have revolutionized the treatment of chronic myeloid leukemia (CML). However, the development of TKI resistance and the subsequent transition from the chronic phase (CP) to blast crisis (BC) threaten CML patients. Accumulating evidence suggests that translational control is crucial for cancer development and progression. Here, we performed high throughput CRISPR/Cas9 screening and identified poly(A) binding protein cytoplasmic 1 (PABPC1) as a driver for CML-BC progression. PABPC1 preferentially improved the translation efficiency of multiple leukemogenic mRNAs with long and highly structured 5' untranslated regions, including BCR-ABL1 and its TKI-resistant mutants, through forming biomolecular condensates. Inhibiting PABPC1 significantly suppressed CML cell proliferation and attenuated disease progression, but did not affect normal hematopoiesis seriously. More importantly, we identified two novel PABPC1 inhibitors, 1,10-Phen and ML324, which inhibited BC progression and overcame TKI resistance in murine and human CML. Overall, our work identified PABPC1 as a selective translation enhancing factor in CML-BC, the genetic or pharmacological inhibition of which overcame TKI resistance and suppressed BC progression in CML.
Project description:Tyrosine kinase inhibitors (TKIs) targeting the BCR-ABL1 fusion tyrosine kinase have revolutionized the treatment of chronic myeloid leukemia (CML). However, the development of TKI resistance and the subsequent transition from the chronic phase (CP) to blast crisis (BC) threaten CML patients. Accumulating evidence suggests that translational control is crucial for cancer development and progression. Here, we performed high throughput CRISPR/Cas9 screening and identified poly(A) binding protein cytoplasmic 1 (PABPC1) as a driver for CML-BC progression. PABPC1 preferentially improved the translation efficiency of multiple leukemogenic mRNAs with long and highly structured 5' untranslated regions, including BCR-ABL1 and its TKI-resistant mutants, through forming biomolecular condensates. Inhibiting PABPC1 significantly suppressed CML cell proliferation and attenuated disease progression, but did not affect normal hematopoiesis seriously. More importantly, we identified two novel PABPC1 inhibitors, 1,10-Phen and ML324, which inhibited BC progression and overcame TKI resistance in murine and human CML. Overall, our work identified PABPC1 as a selective translation enhancing factor in CML-BC, the genetic or pharmacological inhibition of which overcame TKI resistance and suppressed BC progression in CML.
Project description:Tyrosine kinase inhibitors (TKIs) targeting the BCR-ABL1 fusion tyrosine kinase have revolutionized the treatment of chronic myeloid leukemia (CML). However, the development of TKI resistance and the subsequent transition from the chronic phase (CP) to blast crisis (BC) threaten CML patients. Accumulating evidence suggests that translational control is crucial for cancer development and progression. Here, we performed high throughput CRISPR/Cas9 screening and identified poly(A) binding protein cytoplasmic 1 (PABPC1) as a driver for CML-BC progression. PABPC1 preferentially improved the translation efficiency of multiple leukemogenic mRNAs with long and highly structured 5' untranslated regions, including BCR-ABL1 and its TKI-resistant mutants, through forming biomolecular condensates. Inhibiting PABPC1 significantly suppressed CML cell proliferation and attenuated disease progression, but did not affect normal hematopoiesis seriously. More importantly, we identified two novel PABPC1 inhibitors, 1,10-Phen and ML324, which inhibited BC progression and overcame TKI resistance in murine and human CML. Overall, our work identified PABPC1 as a selective translation enhancing factor in CML-BC, the genetic or pharmacological inhibition of which overcame TKI resistance and suppressed BC progression in CML.
Project description:Ablation of the gustatory G-protein, GNAT3, in damage and KRAS G12D induced pancreatic transformation enhanced CXCL1 and CXCL2 expression, altered the immunoregulatory gene expression of CXCR2 expressing myeloid-derived suppressor cells, and increased gMDSC presence to promote the progression of metastatic pancreatic ductal adenocarcinoma.
Project description:Spinocerebellar ataxia type 2 (SCA2) is a neurodegenerative disorder, which is caused by an unstable CAG-repeat expansion in the SCA2 gene, that encodes a polyglutamine tract (polyQ-tract) expansion in ataxin-2 protein (ATXN2). The RNA-binding protein ATXN2 interacts with the poly(A)-binding protein PABPC1, localizing to ribosomes at the rough endoplasmic reticulum or to polysomes. Under cell stress ATXN2 and PABPC1 show redistribution to stress granules where mRNAs are kept away from translation and from degradation. It is unknown whether ATXN2 associates preferentially with specific mRNAs or how it modulates their processing. Here, we investigated Atxn2 knock-out (Atxn2-/-) mouse liver, cerebellum and midbrain regarding their RNA profile, employing oligonucleotide microarrays for screening and RNA deep sequencing for validation. Modest ~1.4-fold upregulations were observed for the level of many mRNAs encoding ribosomal proteins and other translation pathway factors. Quantitative reverse transcriptase PCR and immunoblots in liver tissue confirmed these effects and demonstrated an inverse correlation also with PABPC1 mRNA and protein. ATXN2 deficiency also enhanced phosphorylation of the ribosomal protein S6, while impairing the global protein synthesis rate, suggesting a block between the enhanced translation drive and the impaired execution. Furthermore, ATXN2 overexpression and deficiency retarded cell cycle progression. ATXN2 mRNA levels showed a delayed phasic twofold increase under amino acid and serum starvation, similar to ATXN3, but different from motor neuron disease genes MAPT and SQSTM1. ATXN2 mRNA levels depended particularly on mTOR signalling. Altogether the data implicate ATXN2 in the adaptation of mRNA translation and cell growth to nutrient availability and stress. Factorial design comparing ataxin-2 knock-out mice with wild type littermates in three different tissues (midbrain, cerebellum, liver) and 3 different ages.
Project description:USP10 is an important factor in the progression of colorectal cancer, as inhibition or silencing of USP10 attenuates the aggressive phenotype. USP10 regulates sensitivity to the two widely used EGFR inhibitors gefitinib and osimertinib. Mechanistically, we show that USP10 mediates its effects via the phosphatase INPP4B, which regulates the downstream PI3K/AKT/mTOR signaling pathway. Thus, our study demonstrates for the first time a novel link between USP10 and response to EGFR-targeted therapy.