Currently there is no curative therapy for Chronic Myelogenous Leukemia (CML), and patients must remain on the current prescribed treatment, tyrosine kinase inhibitors (TKI), indefinitely. Although many patients can survive in the chronic phase of the disease under TKI treatment, some patients do progress to the terminal blast crisis phase of the disease. Patients in this terminal phase do not respond to TKI treatment. We evaluated the therapeutic benefit of targeting the oncogene c-MYC in CML, using the CML cell line K562. This was achieved by inhibiting the enzyme O-linked β-N-acetylglucosamine Transferase (OGT), using two indirect inhibitors 2-deoxyglucose and Azaserine, and the direct inhibitor ST078925. Treatment with these inhibitors resulted in decreased half-life of c-MYC protein in K562, reduced c-MYC protein in K562 cells, and reduced K562 cell growth. Together these results suggest that targeting c-MYC through OGT may be a potential therapeutic option for patients with CML.

Class of 2004 Abstract / Objective: To develop and populate a decision-analytic model comparing the cost and efficacy of imatinib versus allogenic bone marrow transplantation (BMT) with a matched unrelated donor in the treatment of newly-diagnosed, Philadelphia positive (Ph (+)), chronic phase, chronic myelogenous leukemia (CML). Design: Markov cohort analysis and Monte Carlo microsimulation. Measurements and Main Results: Direct medical costs were measured from the perspective of a third-party payer. Efficacy data and probabilities were obtained from survivability findings emanating primarily from randomized controlled trials (RCTs). A two-year time horizon was employed with three month treatment cycles. BMT was established as the baseline comparator and the base case was defined as a 35 year old, Ph(+) male patient with newly-diagnosed CML. Results from the Monte Carlo trial found that the incremental cost-efficacy ratio was −$5,000 for imatinib (95th % Confidence Interval: −$70,000, $84,000). Analysis of the cost-efficacy plane indicated that imatinib dominated BMT in 84.69 percent of cases, while BMT was dominant in 0.76 percent of cases. Sensitivity analyses of costs and discount rates found results to be robust. Conclusion: Imatinib was observed in a majority of cases to be both less costly and more efficacious relative to BMT in the treatment of CML, suggesting that this pharmaceutical agent is a dominant therapeutic strategy. When available, the incorporation of long-term clinical data are required to assess cost-efficacy beyond the two-year time horizon of this study.

BCR-ABL is known as the most common translocation in the myeloproliferative (MPD) disorder chronic myelogenous leukemia (CML); it is the first leukemia to be described and associated with a consistent cytogenetic abnormality, termed the Philadelphia chromosome (Ph1). Ph1 is a shortened chromosome 22 that is the consequence of a reciprocal translocation between chromosomes 9 and 22, t(9;22)(q34;q11). BCR-ABL is known to display constitutively active tyrosine kinase activity that leads to the recruitment of downstream effectors of cell proliferation and survival, via several adapter proteins (e.g., GRB2, GAB2, CRKL.) and signaling pathways (e.g., RAS, PI3K, JAK STAT, PDk2-NFkB), all thought to contribute to the pathogenesis of CML. CML, essentially consists of 3 different phases based on disease severity; namely Chronic Phase (CP-AML), Accelerated Phase (AP-CML) and blast crisis (BC-CML). Imatinib, a small molecule ABL kinase inhibitor has been highly effective in treating chronic phase (CP) CML patients. However, a substantial number of patients undergo relapse due to development of resistance to imatinib therapy that leads to BC-CML, which is invariably fatal within weeks to months. Additional genetic aberrations assist in progression and identification of key players that are responsible for transformation is of utmost importance from a therapeutic point of view. Growth arrest DNA damage 45a (Gadd45a) gene, a member in the gadd45 family of genes including Gadd45b & Gadd45g, was identified as a myeloid differentiation primary response gene. There is evidence consistent with it's involvement in G2/M cell cycle arrest and apoptosis in response to multiple stressors, including genotoxic and oncogenic stress. Gadd45a has been shown to participate in cell cycle arrest, DNA repair, cell survival and apoptosis in response to environmental and physiological stress, via protein-protein interactions with key regulators such as PCNA, histones, cdk1, p21, MEKK4, MKK7 and p38. To investigate the effect of Gadd45a in the development of CML, we performed adaptive bone marrow transplantation experiments with either wild type or Gadd45a null myeloid progenitors expressing 210-kD BCR-ABL fusion oncoprotein. We showed that that loss of Gadd45a accelerated BCR-ABL driven CML and correlated with enlarged liver and spleen pointing to more aggressive leukemia. Additionally, we demonstrated that Gadd45a expression in presence of BCR-ABL was independent/distinct from well-known tumor suppressor p53, which suggests that Gadd45a could be considered as a prime and novel candidate for intervention in CML therapy. We also showed that transformed Gadd45a deficient progenitors in the presence of BCR-ABL, exhibited increased proliferation, increased survival and decreased apoptosis when compared to WT/BCR-ABL counterparts. Additionally, we demonstrate that recipients transplanted with Gadd45ako/BCR-ABL bone marrow exhibit increased number of Leukemic stem cells (LSC) harboring BCR-ABL which correlated with accelerated disease development in Gadd45a deficient background. Furthermore, we show that Gadd45ako/BCR-ABL progenitors exhibit increased self-renewal capabilities compared to WT/BCR-ABL progenitors through serial replating assays. Remarkably, we demonstrate that Gadd45ako/BCR-ABL bone marrow cells could be established as a factor independent cell-line and that this cell- line exhibited progenitor like properties; thereby confirming the status of Gadd45a as potent tumor suppressor factor. To shed more light into the mechanism of disease development, we demonstrate that the Gadd45ako/BCR-ABL bone marrow cells exhibit enhanced PI3K-AKT-4E-BP1 signaling and upregulated oncogenic p30C/EBPα expression along with hyperactivation of p38 and Stat5. Finally, to validate our observations in human CML population, we demonstrate that Gadd45a expression correlated with disease progression. We show that Gadd45a expression is upregulated in more indolent CP-CML samples and downregulated in aggressive AP-CML and BC-CML patient samples. Future studies to identify expression of downstream partners of Gadd45a in CML patients, gain of function experiments along with inhibitor studies to highlight mechanistic insights would shed more light into the tumor suppressor function of Gadd45a. Additionally, questions such as; do elevated levels of Gadd45a impede disease progression, does higher expression of Gadd45a indicate better response to Imatinib, still need to be answered in order to understand if Gadd45a agnostic and or combinatorial therapy in CML can be considered as a valid treatment option. The most common mutations of Ras are found in N-RAS (~30%), less frequently in K-RAS (~15%), and most rare in H-RAS in leukemia. Given the role of Gadd45a in modulating the response of hematopoietic cells to stress as well as its function in mediating oncogenic H-Ras carcinogenesis, we wanted to assess if and how Gadd45a loss modulates Nras driven leukemogenesis. By utilizing adaptive bone marrow strategy we show that loss of Gadd45a impeded activated Nras driven leukemia. This correlated with higher incidence of extramedullary hematopoiesis in the liver and spleen sections of WT/NrasD12 recipient mice compared to Gadd45ako/NrasD12 counterparts. Future studies to investigate the biological effects and shed more light on mechanistic insights in recipient mice is still underway. Taken together my work implies that also in the context of hematopoietic malignancies Gadd45a may function as suppressor or promoter of the leukemic phenotype dependent on the oncogenic stress. / Biochemistry

Reagents that bind proteins are applicable in biology for detection of molecules, perturbation of signaling pathways and development of small-molecule pharmaceuticals. Protein ligands interact with proteins, inhibiting or altering their function. They are isolated from combinatorial libraries to interact with a specific target, using selection techniques such as phage display or yeast-two-hybrid assay. For the latter, one inconvenience is the detection of false positives, which can be solved by screening pools containing the samples to be tested, instead of individual samples. Samples are distributed in the pools following a pooling design. The PI-deconvolution pooling design was developed to screen cDNA libraries using the yeast-two-hybrid assay, which are smaller in size than protein ligand combinatorial libraries. Modifications to the PI-deconvolution screening technique were developed to adapt it to the screening of protein ligand combinatorial libraries using the yeast-two-hybrid assay. Every spot of the array containing the combinatorial library was randomly pooled. However, the yeast-two-hybrid assay loses sensitivity when strains are pooled. As PI-deconvolution requires detecting every interaction, we determined the optimal amount of library members that can be pooled in a spot, and the optimal number of replicates to ensure the detection of an interaction.<p> The yeast-two-hybrid assay was used to perform a screening of a combinatorial library with seven domains of BCR-ABL, which were pooled according to PI-deconvolution. BCR-ABL is a chimeric protein with unregulated kinase activity that is responsible for chronic myelogenous leukemia. The scaffold used in the combinatorial library was an engineered intein that forms lariat peptides. After a screening of this library was performed, positive interactions were detected in 775 spots of the arrays that contained 1432 positive hits. Only 53 spots were deconvoluted. The coding sequences of the lariat peptides were determined for 23 lariat peptides interacted with the GEF domain of BCR, and for ABL, two with the FABD domain, one with the SH1 domain, and one with the SH3 domain. Finally, a &beta;-galactosidase assay was performed to assess the affinity of the lariat peptides for their target.<p> The isolated lariat peptides are potential inhibitors of BCR-ABL that can have therapeutic potential. This study will improve other screenings of combinatorial libraries with the yeast-two-hybrid assay.

Reagents that bind proteins are applicable in biology for detection of molecules, perturbation of signaling pathways and development of small-molecule pharmaceuticals. Protein ligands interact with proteins, inhibiting or altering their function. They are isolated from combinatorial libraries to interact with a specific target, using selection techniques such as phage display or yeast-two-hybrid assay. For the latter, one inconvenience is the detection of false positives, which can be solved by screening pools containing the samples to be tested, instead of individual samples. Samples are distributed in the pools following a pooling design. The PI-deconvolution pooling design was developed to screen cDNA libraries using the yeast-two-hybrid assay, which are smaller in size than protein ligand combinatorial libraries. Modifications to the PI-deconvolution screening technique were developed to adapt it to the screening of protein ligand combinatorial libraries using the yeast-two-hybrid assay. Every spot of the array containing the combinatorial library was randomly pooled. However, the yeast-two-hybrid assay loses sensitivity when strains are pooled. As PI-deconvolution requires detecting every interaction, we determined the optimal amount of library members that can be pooled in a spot, and the optimal number of replicates to ensure the detection of an interaction.<p> The yeast-two-hybrid assay was used to perform a screening of a combinatorial library with seven domains of BCR-ABL, which were pooled according to PI-deconvolution. BCR-ABL is a chimeric protein with unregulated kinase activity that is responsible for chronic myelogenous leukemia. The scaffold used in the combinatorial library was an engineered intein that forms lariat peptides. After a screening of this library was performed, positive interactions were detected in 775 spots of the arrays that contained 1432 positive hits. Only 53 spots were deconvoluted. The coding sequences of the lariat peptides were determined for 23 lariat peptides interacted with the GEF domain of BCR, and for ABL, two with the FABD domain, one with the SH1 domain, and one with the SH3 domain. Finally, a &beta;-galactosidase assay was performed to assess the affinity of the lariat peptides for their target.<p> The isolated lariat peptides are potential inhibitors of BCR-ABL that can have therapeutic potential. This study will improve other screenings of combinatorial libraries with the yeast-two-hybrid assay.

Chronic myelogenous leukemia (CML) is a clonal hematopoetic stem cell disorder characterized by proliferation of cells expressing BCR-ABL fusion protein. In the BCR-ABL+ leukemia murine model, 12B1, we explored the therapeutic applicability of chaperone-rich cell lysate (CRCL) in the context of syngeneic hematopoietic cell transplantation (HCT) to treat pre-existing leukemia. Our results demonstrate that tumor growth is significantly delayed in mice receiving syngeneic HCT from 12B1 tumor CRCL immunized donors compared to animals receiving HCT from non-immunized donors. CRCL immunization post-immune HCT further hindered tumor growth when compared to immune HCT without post-transplant vaccination. The magnitude of the immune response was consistent with the anti-tumor effects observed in vivo. We also demonstrated that cured mice had developed long-term tumor specific immunity against 12B1 tumor cells. In addition, we documented that both T cells and NK cells contributed to the anti-tumor effect of CRCL vaccination as depletion of either subset hampered tumor growth delay. Thus, our results suggest that CRCL represents a promising vaccine capable of generating specific immune responses. This anti-tumor immunity can be effectively transferred to a host via HCT and further enhanced post-HCT with additional tumor CRCL immunizations.CD4+CD25+ regulatory T cells (Treg) play a central role in the prevention of autoimmunity and in the control of immune responses by down-regulating the function of effector CD4+ or CD8+ T cells. The role of Treg in Mycobacterium tuberculosis infection and persistence is inadequately documented. Therefore, the current study was designed to determine whether CD4+CD25+ FoxP3+ regulatory T cells may modulate immunity against human tuberculosis (TB). Ourresults indicate that the number of CD4+CD25+FoxP3+ Treg increases in the blood or at the site of infection in active TB patients. The frequency of CD4+CD25+FoxP3+ Treg in pleural fluid inversely correlates with local MTB-specific immunity(p<0.002). These CD4+CD25+FoxP3+ T lymphocytes isolated from the blood and pleural fluid are capable of suppressing MTB-specific IFN-γ and IL-10 production in TB patients. Therefore, CD4+CD25+FoxP3+ Treg expanded in TB patients suppress Mycobacterium tuberculosis immunity and may therefore contribute to the pathogenesis of human TB.

No description available.

Cancer remains the second leading cause of death in the United States and the world, despite years of research and the development of different treatments. One reason for this is cancer cells are able to survive through adaptation to their environment and aberrantly activated growth signaling. As such, developing new therapies that overcome these hurdles are necessary to combat cancer. Previous work in our laboratory using RNA interference screening identified genes that regulate the survival of glioblastoma (GBM) or autophagy in chronic myelogenous leukemia (CML) cancer cells. One screen identified Phosphatidylinositol-4,5-bisophosphate 3-kinase catalytic subunit beta (PIK3CB) in the family of Phosphatidylinositol 3-kinases (PI3K) as a survival kinase gene in GBM. Work contained in this dissertation set out to study PIK3CB mediated GBM cell survival. We report that only PIK3CB, in its family of other PI3K genes, is a biomarker for GBM recurrence and is selectively important for GBM cell survival. Another screen identified the long non-coding RNA, Linc00467, as a gene that regulates autophagy in CML. Autophagy is a dynamic survival process used by all cells, benign and cancerous, where cellular components are broken down and re-assimilated to sustain survival. Work contained in this dissertation set out to characterize the role that Linc00467 serves in regulating autophagy in a myriad of cancers. Collectively our data have showed Linc00467 to actively repress levels of autophagy in cancer cells. Further, our data revealed an important role for Linc00467 in regulating the stability of the autophagy regulating protein serine-threonine kinase 11 (STK11). Because of the unique role that Linc00467 serves in regulating autophagy we renamed it as, autophagy regulating long intergenic noncoding RNA or ARLINC. Taken together the work in this dissertation unveils the inner-workings of two important cancer cell survival pathways and shows their potential for development into therapeutic targets to treat cancer. / Ph. D. / Cancer remains the second leading cause of death in the United States and the world, despite years of research and the development of different treatments. One reason for this is cancer cells are able to survive through adaptation to their environment and aberrantly activated growth signaling. As such, developing new therapies that overcome these hurdles are necessary to combat cancer. Previous work in our laboratory using high throughput genetic screens identified genes that regulate the survival of cancer cells from a deadly type of brain cancer called glioblastoma (GBM). Another screen revealed genes that regulate a process called autophagy in cancer cells from a type of leukemia called chronic myelogenous leukemia (CML). Autophagy is a process that cancer cells can use to survive through chemotherapy. One screen identified the gene Phosphatidylinositol-4,5-bisophosphate 3-kinase catalytic subunit β (PIK3CB) in the family of Phosphatidylinositol 3-kinases (PI3K) as a survival gene in GBM. Work contained in this dissertation set out to study PIK3CB mediated GBM cell survival. We report that only PIK3CB, in its family of other PI3K genes, is a biomarker for GBM recurrence and is selectively important for GBM cell survival. Another screen identified the long non-coding RNA, Linc00467, as a gene that regulates autophagy in CML. Autophagy is a dynamic survival process used by all cells, normal and cancerous, where cellular components are broken down and reassimilated to sustain survival. Work contained in this dissertation set out to characterize the role that Linc00467 serves in regulating autophagy in different types of cancer. Collectively our data have showed Linc00467 to actively repress levels of autophagy in cancer cells. Further, our data revealed an important role for Linc00467 in regulating the stability of the autophagy regulating protein serine-threonine kinase 11 (STK11). Because of the unique role that Linc00467 serves in regulating autophagy we renamed it as, autophagy regulating long intergenic noncoding RNA or ARLINC. Taken together the work in this dissertation unveils the inner-workings of two important cancer cell survival pathways and shows their potential for development into therapeutic targets to treat cancer.

Orientador: Carmen Silvia Passos Lima / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Ciências Médicas / Made available in DSpace on 2018-08-21T21:59:05Z (GMT). No. of bitstreams: 1 Numa_IramaiaAngelicaNeri_M.pdf: 4547636 bytes, checksum: 22548046dff40a3bb4e586230e3f13b7 (MD5) Previous issue date: 2012 / Resumo: O mesilato de imatinibe (MI) é o tratamento de escolha para pacientes com leucemia mielóide crônica (LMC) em fase crônica, mas a resposta ao medicamento é variável em indivíduos distintos. A CYP3A4 é a principal enzima responsável pelo metabolismo hepático do MI. O alelo variante G do polimorfismo CYP3A4 A-290G codifica menor quantidade de enzima do que o alelo selvagem A, mas o papel do referido polimorfismo em pacientes com LMC tratados com MI é desconhecido. Os objetivos deste trabalho foram os de avaliar a eficácia, a toxicidade a sobrevida livre de progressão (SLP) e global (SG) de pacientes com LMC durante a administração de MI e verificar se estes parâmetros são alterados pela variabilidade interindividual no metabolismo do fármaco, relacionada ao polimorfismo CYP3A4 A-290G. Foram avaliados 100 pacientes com LMC em FC precoce atendidos no Centro de Hematologia e Hemoterapia da UNICAMP. O diagnóstico da LMC, o exame hematológico, o cariótipo, a pesquisa do gene BCR-ABL e os genótipos do polimorfismo CYP3A4 A-290G foram realizados por métodos convencionais. Os pacientes receberam o MI na dose de 400mg e a resposta ao tratamento foi avaliada segundo os critérios do European Leukemia Net. Identificamos respostas hematológicas, citogenética e molecular similares às previamente descritas. A taxa de resposta hematológica foi de 95% ao longo do estudo. Aos doze meses, as respostas citogenética completa ou parcial foram de 72% e 11% respectivamente. Já as taxas de respostas moleculares completas e maiores aos 22 meses foram de 28% e 26%, respectivamente. A sobrevida global foi de 94% aos 92 meses bem como a sobrevida livre de progressão para as fases avançadas da doença. Observamos que pacientes com resposta citogenética completa ou parcial e molecular xiv completa ou maior apresentaram maior SLP e SG do que os demais. Cerca de 13% dos pacientes era portadores do genótipo AG do polimorfismo CYP3A4 A-290G, o qual esteve associado à obtenção de resposta molecular completa tardia e tendência à menor SLP e SG. Apesar da hipótese do alelo variante (G) exibir um fenótipo metabolizador lento associado a uma menor taxa de biotransformação do MI e portando maior risco de reações tóxicas, não observamos diferenças entre as toxicidades hematológicas e não hematológica (P= 0,28). Assim, concluímos que nossos pacientes respondem de forma similar ao MI do que os demais e que o polimorfismo CYP3A4 A-290G pode vir a funcionar como biomarcador de resposta ao fármaco / Abstract: Imatinib (IM) is widely recognized as the standard of care in the first-line treatment of CML but the response to the drug is variable in different subjects. CYP3A4 is the main enzyme responsible for the hepatic metabolism of Imatinib. The G variant allele of the polymorphism A-290G encoding least amount of enzyme than the wild-type allele, but the role of this polymorphism in CML patients treated with Imatinib is unknown. The aims of this study were to assess the efficacy, toxicity, progression-free survival (PFS) and overall survival (OS) of patients with CML during the administration of Imatinib and check if these parameters are affected y interindividual variability in drug metabolism, the polymorphism related to CYP3A4 A-290G. We evaluated 100 patients with CML newly diagnosed at Center of Hematology and Hemoterapy of UNICAMP. The diagnosis of CML, hematology, karyotyping, research the BCR-ABL gene polymorphism and CYP3A4 genotypes A-290G were performed by conventional methods. Patients received a dose of 400mg IM and treatment response was assessed according to the criteria of the European Leukemia Net responses identified hematologic, cytogenetic and molecular similar to those previously described. The hematologic response rate was 95% throughout the study. At 22 months the complete or partial cytogenetic responses were 72% and 11% respectively. The complete molecular response rates at 22 months were 28% and 26%, respectively. Overall survival (OS) was 94% at 92 months and the progression-free survival (PFS) for advanced stages of the disease. We observed that patients with partial or complete cytogenetic response and major molecular and complete PFS and OS showed higher than other. We observed that patients with partial or complete cytogenetic response and major molecular xvi and complete PFS and OS showed higher than others. About 13% of patients were of AG genotype polymorphism of the CYP3A4 -290A>G, which was associated with achieving complete molecular response and late tendency to lower PFS and OS. Despite the possibility of variant allele (G) display a slow metabolizer phenotype associated with a lower rate of biotransformation of IM and carrying greater risk of toxic reactions, no significant differences between hematological and non hematological toxicities (P= 0,28). Thus, we conclude that our patients respond similary to IM than others and that the polymorphism CYP3A4 -290A>G might function as a biomarker of response to the drug / Mestrado / Ciencias Basicas / Mestra em Clínica Médica

Class of 2016 Abstract / Objectives: Patient medication adherence is a basic requirement for treating chronic myelogenous leukemia (CML) with oral tyrosine kinase inhibitors (TKIs). When imatinib adherence rates are less than 80 or 90 percent, major and complete molecular responses, respectively, do not happen. The purpose of this study was to determine the effect of a real-time medication monitoring (RTMM) reminder system adherence program on the medication possession ratio (MPR). Methods: This analytic study was a retrospective cohort study and used data extracted from chart reviews for patients who received services from 2011 to 2015. It was approved by the Institutional Review Board. The study consisted of an intervention group and a control group (50 patients each). MPRs, demographic, descriptive, and categorical variables were summarized using means, standard deviations (SD), and frequencies/percentages. Results: The study population consisted of adult patients (mean age=62.2, SD=2.7, 50% male) treated by Avella Specialty Pharmacy who received imatinib or nilotinib as treatment for CML, gastrointestinal stromal tumors (GIST), or a similar positive Philadelphia chromosome cancer. Only 4% of patients in the intervention group had an < 85% MPR, compared to 46% in the control group (p < 0.001). Conclusions: In those patients who had an MPR of ≥ 85%, the difference between the groups was statistically significant. As past studies have shown, adherence rates greater than 90% have a higher likelihood of a major or complete molecular response and a greatly reduced risk of disease progression.