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Supplementary Data from In Vivo Monitoring of Polycythemia Vera Development Reveals Carbonic Anhydrase 1 as a Potent Therapeutic Target

Current murine models of myeloproliferative neoplasms (MPNs) cannot examine how MPNs progress from a single bone marrow source to the entire hematopoietic system. Thus, using transplantation of knock-in JAK2V617F hematopoietic cells into a single irradiated leg, we show development of polycythemia vera (PV) from a single anatomic site in immunocompetent mice. Barcode experiments reveal that grafted JAK2V617F stem/progenitor cells migrate from the irradiated leg to nonirradiated organs such as the contralateral leg and spleen, which is strictly required for development of PV. Mutant cells colonizing the nonirradiated leg efficiently induce PV in nonconditioned recipient mice and contain JAK2V617F hematopoietic stem/progenitor cells that express high levels of carbonic anhydrase 1 (CA1), a peculiar feature also found in CD34+ cells from patients with PV. Finally, genetic and pharmacologic inhibition of CA1 efficiently suppresses PV development and progression in mice and decreases PV patients’ erythroid progenitors, strengthening CA1 as a potent therapeutic target for PV.Significance:Follow-up of hematopoietic malignancies from their initiating anatomic site is crucial for understanding their development and discovering new therapeutic avenues. We developed such an approach, used it to characterize PV progression, and identified CA1 as a promising therapeutic target of PV.This article is highlighted in the In This Issue feature, p. 265

Supplementary Table from In Vivo Monitoring of Polycythemia Vera Development Reveals Carbonic Anhydrase 1 as a Potent Therapeutic Target

Apart from well-known genetic abnormalities, several studies have reported variations in protein expression in Philadelphia-negative myeloproliferative neoplasm (MPN) patients that could contribute toward their clinical phenotype. In this context, a quantitative mass spectrometry proteomics protocol was used to identify differences in the granulocyte proteome with the goal to characterize the pathogenic role of aberrant protein expression in MPNs. LC/MS-MS (LTQ Orbitrap) coupled to iTRAQ labeling showed significant and quantitative differences in protein content among various MPN subtypes [polycythemia vera (PV), essential thrombocythemia (ET), and primary myelofibrosis (PMF)], and according to the genetic status of JAK2 (JAK2V617F presence and JAK2V617F allele burden). A number of differentially expressed proteins were identified, with the most frequent being members of the RAS GTPase family and oxidative stress regulatory proteins. Subsequent analysis found that calreticulin (CALR), known to be involved in calcium homeostasis and apoptotic signaling, was overexpressed in JAK2V617F granulocytes compared with JAK2 wild type and independently of the JAK2V617F allele burden. Finally, it was demonstrated, in a Ba/F3 cell model, that increased calreticulin expression was directly linked to JAK2V617F and could be regulated by JAK2 kinase inhibitors.Implications: In conclusion, these results reveal proteome alterations in MPN granulocytes depending on the phenotype and genotype of patients, highlighting new oncogenic mechanisms associated with JAK2 mutations and overexpression of calreticulin. Mol Cancer Res; 15(7); 852–61. ©2017 AACR.

Table S1. Deregulated proteins between JAK2(+) PV and JAK2(-) ET/PMF. Table S2. Deregulated proteins between JAK2(+) ET and JAK2(-) ET/PMF. Table S3. Deregulated proteins between JAK2(+) PMF and JAK2(-) ET/PMF. Table S4. Deregulated proteins between JAK2(+) PV and JAK2(+) PMF. Table S5. Deregulated proteins between JAK2(+) ET and JAK2(+) PMF. Table S6. Deregulated proteins between JAK2(+) PV and JAK2(+) ET. Table S7. Deregulated pathways between JAK2(+) PV and JAK2(-) ET/PMF. Table S8. Deregulated pathways between JAK2(+) ET and JAK2(-) ET/PMF. Table S9. Deregulated pathways between JAK2(+) PMF and JAK2(-) ET/PMF. Table S10. Deregulated pathways between JAK2(+) PV and JAK2(+) PMF. Table S11. Deregulated pathways between JAK2(+) ET and JAK2(+) PMF. Table S12. Deregulated pathways between JAK2(+) PV and JAK2(+) ET.

Supplementary Figure 1 from AKT1 Inhibits Homologous Recombination by Inducing Cytoplasmic Retention of BRCA1 and RAD51

PDF file - 32K

Supplementary Figure 5 from AKT1 Inhibits Homologous Recombination by Inducing Cytoplasmic Retention of BRCA1 and RAD51

Supplementary Figure 6 from AKT1 Inhibits Homologous Recombination by Inducing Cytoplasmic Retention of BRCA1 and RAD51

Supplementary Figure 4 from AKT1 Inhibits Homologous Recombination by Inducing Cytoplasmic Retention of BRCA1 and RAD51

PDF file - 34K, Includes lentiviral constructs and transduction, immunoblots and antibodies, RNA extraction data, and supplementary references.

Supplementary Figure 2 from AKT1 Inhibits Homologous Recombination by Inducing Cytoplasmic Retention of BRCA1 and RAD51

Supplementary Figure 3 from AKT1 Inhibits Homologous Recombination by Inducing Cytoplasmic Retention of BRCA1 and RAD51

Supplementary Movie from AKT1 Inhibits Homologous Recombination by Inducing Cytoplasmic Retention of BRCA1 and RAD51

PDF file - 589K, shS5A, shS5B and shS5A/B differentially affect STAT5 expression in CML and normal stem/progenitor cells (S1); Characteristics of CML cells following addition of the indicated shRNA encoding lentiviral particles (S2); shS5A enhances ROS which depends on NADPH oxidase activity in CML cells (S3); Characteristics of IM-sensitive and -resistant CML cells (S4); Expression of STAT5A and STAT5B mRNA in normal and CML CD34+ stem/progenitor cells (S5).

Apart from well-known genetic abnormalities, several studies have reported variations in protein expression in Philadelphia-negative myeloproliferative neoplasm (MPN) patients that could contribute toward their clinical phenotype. In this context, a quantitative mass spectrometry proteomics protocol was used to identify differences in the granulocyte proteome with the goal to characterize the pathogenic role of aberrant protein expression in MPNs. LC/MS-MS (LTQ Orbitrap) coupled to iTRAQ labeling showed significant and quantitative differences in protein content among various MPN subtypes [polycythemia vera (PV), essential thrombocythemia (ET), and primary myelofibrosis (PMF)], and according to the genetic status of JAK2 (JAK2V617F presence and JAK2V617F allele burden). A number of differentially expressed proteins were identified, with the most frequent being members of the RAS GTPase family and oxidative stress regulatory proteins. Subsequent analysis found that calreticulin (CALR), known to be involved in calcium homeostasis and apoptotic signaling, was overexpressed in JAK2V617F granulocytes compared with JAK2 wild type and independently of the JAK2V617F allele burden. Finally, it was demonstrated, in a Ba/F3 cell model, that increased calreticulin expression was directly linked to JAK2V617F and could be regulated by JAK2 kinase inhibitors. Implications: In conclusion, these results reveal proteome alterations in MPN granulocytes depending on the phenotype and genotype of patients, highlighting new oncogenic mechanisms associated with JAK2 mutations and overexpression of calreticulin. Mol Cancer Res; 15(7); 852–61. ©2017 AACR.

AKT1 is frequently up-regulated in sporadic breast cancer, whereas BRCA1 is frequently mutated in familial breast cancer. Because BRCA1 is involved in homologous recombination (HR), we addressed whether AKT1 also has an effect on this process. We showed that AKT1 repressed HR through cytoplasmic retention of BRCA1 and RAD51 proteins, resulting in a BRCA1-deficient–like phenotype. This process does not require direct BRCA1 phosphorylation by AKT1. The cytoplasmic retention of BRCA1 and RAD51 correlated with activated AKT1 in tumor cell lines and in biopsies from sporadic breast cancers. Under nonpathologic conditions, fibroblast growth factor, which activates AKT1 and stimulates proliferation in fibroblasts, impaired excessive HR without fully inhibiting it, promoting genome stability. Our study reveals that the regulation of BRCA1 and RAD51 is altered in a high frequency of sporadic breast cancers and highlights the role of extracellular AKT signaling-dependent regulation of HR and genome stability. [Cancer Res 2008;68(22):9404–12]

S78454 (also called PCI-24781) is an orally bioavailable, hydroxamate-based pan-HDACi currently being tested in clinical trials in the US and EU. Like many other HDACi, this drug induces a reversible thrombocytopenia. This thrombocytopenia, which was associated with a decrease in either GATA1 transcriptional activity or the expression of proteins of the Rho GTPase family (RhoA, Cdc42 or Rac), remains poorly understood. Given that the S78454 plasma level is above 100nM in treated patients, we performed a dose-response analysis (from 10 to 100 nM) of the drug effects on CFU-MK growth and cell proliferation. CFU-MKs were generated by ex vivo culture of CD34-positive cells and their differentiation was dose-dependently decreased after either a 24-hour treatment or a continuous exposure to S78454. This effect was associated with a dose-dependent decrease in MK proliferation. When added at day 8 of the culture, at a time-point when MK have nearly finished their endomitotic process and are entering in the cytoplasmic maturation step, S78454 induced a dose-dependent decrease (ten- to- two fold at 100nM and 20nM, respectively) in proplatelet formation, even when secondarily removed from the culture medium. The decreased proliferation was associated with an increased apoptosis, as demonstrated by the presence of a sub-G1 peak after propidium iodide staining, Annexin V binding, and caspase-3 proteolysis. We did not observed any blockade in the TPO/MPL/JAK2 signaling since ERK, Stat3 and Stat5 phosphorylation remained unaffected. Interestingly, MK exposed to S78454 displayed an increase in γH2AX foci formation and a decrease in Rad51 expression, a major mediator of homologous recombination, indicating a defective repair of DNA double-strand breaks. Consequently, P53 became phosphorylated in MKs, and the expression of its target genes BAX and P21 was increased. Altogether, these results suggest that S78454-induced thrombocytopenia may be mediated by induction of apoptosis in MK due to DNA-double-strand breaks and p53 activation. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 2022. doi:1538-7445.AM2012-2022