Kehinde Adekola

Glucose transporters in cancer metabolism.

Purpose of review Transformed cells exhibit a high rate of glucose consumption beyond that necessary for ATP synthesis. Glucose aids in the generation of biomass and regulates cellular signaling critical for oncogenic progression. A key rate-limiting step in glucose utilization is the transport of glucose across the plasma membrane. This review will highlight key glucose transporters (GLUTs) and current therapies targeting this class of proteins. Recent findings GLUTs, enabling the facilitative entry of glucose into a cell, are increasingly found to be deregulated in cancer. Although cancer-specific expression patterns for GLUTs are being identified, comprehensive analyses substantiating a role for individual GLUTs are still required. Studies defining GLUTs as being rate-limiting in specific tumor contexts, the identification of GLUT1 inhibitors via synthetic lethality screens, novel engagement of the insulin-responsive GLUT4 in myeloma and identification of GLUT9 being a urate transporter, are key advances underscoring the need for continued investigation of this large and enigmatic class of proteins. Summary Tumor cells exhibit elevated levels of glucose uptake, a phenomenon that has been capitalized upon for the prognostic and diagnostic imaging of a wide range of cancers using radio-labeled glucose analogs. We have, however, not yet been able to target glucose entry in a tumor cell-specific manner for therapy. GLUTs have been identified as rate-limiting in specific tumor contexts. The identification and targeting of tumor-specific GLUTs provide a promising approach to block glucose-regulated metabolism and signaling more comprehensively.

Increasing use of allogeneic hematopoietic cell transplantation in patients aged 70 years and older in the United States

In this study, we evaluated trends and outcomes of allogeneic hematopoietic cell transplantation (HCT) in adults ≥70 years with hematologic malignancies across the United States. Adults ≥70 years with a hematologic malignancy undergoing first allogeneic HCT in the United States between 2000 and 2013 and reported to the Center for International Blood and Marrow Transplant Research were eligible. Transplant utilization and transplant outcomes, including overall survival (OS), progression-free survival (PFS), and transplant-related mortality (TRM) were studied. One thousand one hundred and six patients ≥70 years underwent HCT across 103 transplant centers. The number and proportion of allografts performed in this population rose markedly over the past decade, accounting for 0.1% of transplants in 2000 to 3.85% (N = 298) in 2013. Acute myeloid leukemia and myelodysplastic syndromes represented the most common disease indications. Two-year OS and PFS significantly improved over time (OS: 26% [95% confidence interval (CI), 21% to 33%] in 2000-2007 to 39% [95% CI, 35% to 42%] in 2008-2013, P < .001; PFS: 22% [16% to 28%] in 2000-2007 to 32% [95% CI, 29% to 36%] in 2008-2013, P = .003). Two-year TRM ranged from 33% to 35% and was unchanged over time (P = .54). Multivariable analysis of OS in the modern era of 2008-2013 revealed higher comorbidity by HCT comorbidity index ≥3 (hazard ratio [HR], 1.27; P = .006), umbilical cord blood graft (HR, 1.97; P = .0002), and myeloablative conditioning (HR, 1.61; P = .0002) as adverse factors. Over the past decade, utilization and survival after allogeneic transplant have increased in patients ≥70 years. Select adults ≥70 years with hematologic malignancies should be considered for transplant.

Targeting the Metabolic Plasticity of Multiple Myeloma with FDA Approved Ritonavir and Metformin

Purpose: We have previously demonstrated that ritonavir targeting of glycolysis is growth inhibitory and cytotoxic in a subset of multiple myeloma cells. In this study, our objective was to investigate the metabolic basis of resistance to ritonavir and to determine the utility of cotreatment with the mitochondrial complex I inhibitor metformin to target compensatory metabolism. Experimental Design: We determined combination indices for ritonavir and metformin, impact on myeloma cell lines, patient samples, and myeloma xenograft growth. Additional evaluation in breast, melanoma, and ovarian cancer cell lines was also performed. Signaling connected to suppression of the prosurvival BCL-2 family member MCL-1 was evaluated in multiple myeloma cell lines and tumor lysates. Reliance on oxidative metabolism was determined by evaluation of oxygen consumption, and dependence on glutamine was assessed by estimation of viability upon metabolite withdrawal in the context of specific metabolic perturbations. Results: Ritonavir-treated multiple myeloma cells exhibited increased reliance on glutamine metabolism. Ritonavir sensitized multiple myeloma cells to metformin, effectively eliciting cytotoxicity both in vitro and in an in vivo xenograft model of multiple myeloma and in breast, ovarian, and melanoma cancer cell lines. Ritonavir and metformin effectively suppressed AKT and mTORC1 phosphorylation and prosurvival BCL-2 family member MCL-1 expression in multiple myeloma cell lines in vitro and in vivo. Conclusions: FDA-approved ritonavir and metformin effectively target multiple myeloma cell metabolism to elicit cytotoxicity in multiple myeloma. Our studies warrant further investigation into repurposing ritonavir and metformin to target the metabolic plasticity of myeloma to more broadly target myeloma heterogeneity and prevent the reemergence of chemoresistant aggressive multiple myeloma. Clin Cancer Res; 21(5); 1161–71. ©2014 AACR.

Can a female donor for a male recipient decrease the relapse rate for patients with acute myeloid leukemia treated with allogeneic hematopoietic stem cell transplantation

The mismatched minor histocompatibility antigens present on Y chromosome (H-Y) in male recipients receiving stem cells from female donors may contribute to the graft-versus-leukemia effect and results in a reduced relapse rate, especially in patients with high-risk disease. We retrospectively compared the outcomes of male patients with acute myeloid leukemia who received an allogeneic hematopoietic stem cell transplant (HSCT) from female donors (F-M) (174 patients) versus other gender combinations (667 patients). Median age was 50 years (range, 18 to 74 years). For the whole group, the 1-year cumulative incidence of relapse was significantly lower in F-M group (34.1% versus 41.3%, P = .044), whereas nonrelapse mortality (NRM) was higher (23.2% versus 15.7%, P = .004). For patients younger than 50 years beyond first complete remission, the F-M group was associated with lower relapse rate (42.5% versus 55.2%, P = .045) whereas NRM was not significantly different (35.8% versus 25.5%, P = .141). Although survival was not significantly improved, transplantation from a female donor for male recipient was associated with a lower relapse rate. When relapse is the most common concern for treatment failure, especially for younger patients, a female donor for a male recipient might be beneficial to decrease relapse rate after transplantation. Future studies are needed to explore how the H-Y mismatch may improve survival after transplantation.

Investigating and targeting chronic lymphocytic leukemia metabolism with the human immunodeficiency virus protease inhibitor ritonavir and metformin

Abstract Chronic lymphocytic leukemia (CLL) remains fatal due to the development of resistance to existing therapies. Targeting abnormal glucose metabolism sensitizes various cancer cells to chemotherapy and/or elicits toxicity. Examination of glucose dependency in CLL demonstrated variable sensitivity to glucose deprivation. Further evaluation of metabolic dependencies of CLL cells resistant to glucose deprivation revealed increased engagement of fatty acid oxidation upon glucose withdrawal. Investigation of glucose transporter expression in CLL reveals up-regulation of glucose transporter GLUT4. Treatment of CLL cells with human immunodeficiency (HIV) protease inhibitor ritonavir, which inhibits GLUT4, elicits toxicity similar to that elicited upon glucose deprivation. CLL cells resistant to ritonavir are sensitized by co-treatment with metformin, potentially targeting compensatory mitochondrial complex 1 activity. Ritonavir and metformin have been administered in humans for the treatment of diabetes in patients with HIV, demonstrating the tolerance to this combination in humans. Our studies strongly substantiate further investigation of Food and Drug Administration approved ritonavir and metformin for CLL.

An update on allogeneic hematopoietic progenitor cell transplantation for myeloproliferative neoplasms in the era of tyrosine kinase inhibitors.

Myeloproliferative neoplasms are a category of diseases that have been traditionally amenable to allogeneic hematopoietic progenitor cell transplantation. Current developments in drug therapy have delayed transplantation for more advanced phases of the disease, especially for patients with CML, whereas transplantation remains a mainstream treatment modality for patients with advanced myelofibrosis and chronic myelomonocytic leukemia. Reduced-intensity conditioning has decreased the treatment-related mortality, and advances in the use of alternative donors for transplantation could extend the use of this procedure to an increasing number of patients with improved safety and efficacy. Here we review the current knowledge about allogeneic transplantation for myeloproliferative neoplasms and discuss the most important aspects to be considered when contemplating transplantation for patients with these diseases. Janus kinase 2 inhibitors offer the promise to improve spleen size and performance of patients with myelofibrosis and extend transplantation for patients with more advanced disease.

Advances in Adjuvant Therapy of Gastrointestinal Stromal Tumors

The Gastrointestinal Stromal Tumor (GIST) is the most common sarcoma of the gastrointestinal tract. Major prognostic indices in the evaluation and management of GIST include the size, location and tumor mitotic rate. The discovery of the mutation in the tyrosine kinase receptor c-KIT (CD117) revolutionized the treatment of GIST in the early twenty-first century. Since the first case report of the success of the tyrosine kinase inhibitor (TKI) imatinib, in the treatment of a female patient with metastatic GIST, the paradigm of treatment of this tumor has evolved tremendously. The initial use in metastatic GISTs has progressed to use of the TKI in both the adjuvant and neoadjuvant settings. It is now standard of care for patients with complete resection of primary localized GIST, with high risk of recurrence, to have at least one year of adjuvant imatinib. Recent SSGVXIII study shows that patients benefit from extended duration of therapy.

Donor type, in addition to transplantation in chronic phase and myeloablative conditioning, influence transplant survival for patients with advanced chronic myeloid leukemia in the era of tyrosine kinase inhibitors

Donor type, in addition to transplantation in chronic phase and myeloablative conditioning, influence transplant survival for patients with advanced chronic myeloid leukemia in the era of tyrosine kinase inhibitors

Allogeneic Hematopoietic Cell Transplantation for Adult T Cell Acute Lymphoblastic Leukemia

Allogeneic hematopoietic cell transplantation (HCT) is recommended for patients with T cell acute lymphoblastic leukemia (T-ALL) in second or later complete remission (CR) and high-risk patients in first CR. Given its relative rarity, data on outcomes of HCT for T-ALL are limited. We conducted a multicenter retrospective cohort study using data from 208 adult patients who underwent HCT between 2000 and 2014 to describe outcomes of allogeneic HCT for T-ALL in the contemporary era. The median age at HCT was 37 years, and the majority of patients underwent HCT in CR, using total body irradiation (TBI)-based myeloablative conditioning regimens. One-quarter of the patients underwent alternative donor HCT using a mismatched, umbilical cord blood, or haploidentical donor. With a median follow up of 38 months, overall survival at 5 years was 34%. The corresponding cumulative incidence of non-relapse mortality and relapse was 26% and 41%, respectively. In multivariable analysis, factors significantly associated with overall survival were the use of TBI (HR, 0.57; P = .021), age >35 years (HR, 1.55; P = .025), and disease status at HCT (HR, 1.98; P = .005 for relapsed/refractory disease compared with CR). Relapse was the most common cause of death (58% of patients). Allogeneic HCT remains a potentially curative option in selected patients with adult T-ALL, although relapse is a major cause of treatment failure.

Neurocognitive dysfunction in hematopoietic cell transplant recipients: expert review from the late effects and Quality of Life Working Committee of the CIBMTR and complications and Quality of Life Working Party of the EBMT

Hematopoietic cell transplantation (HCT) is a potentially curative treatment for children and adults with malignant and non-malignant diseases. Despite increasing survival rates, long-term morbidity following HCT is substantial. Neurocognitive dysfunction is a serious cause of morbidity, yet little is known about neurocognitive dysfunction following HCT. To address this gap, collaborative efforts of the Center for International Blood and Marrow Transplant Research and the European Society for Blood and Marrow Transplantation undertook an expert review of neurocognitive dysfunction following HCT. In this review, we define what constitutes neurocognitive dysfunction, characterize its risk factors and sequelae, describe tools and methods to assess neurocognitive function in HCT recipients, and discuss possible interventions for HCT patients with this condition. This review aims to help clinicians understand the scope of this health-related problem, highlight its impact on well-being of survivors, and to help determine factors that may improve identification of patients at risk for declines in cognitive functioning after HCT. In particular, we review strategies for preventing and treating neurocognitive dysfunction in HCT patients. Lastly, we highlight the need for well-designed studies to develop and test interventions aimed at preventing and improving neurocognitive dysfunction and its sequelae following HCT.