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Abstract. Acute lymphoblastic leukemia (ALL) accounts for 30% of all pediatric cancers. Currently available treatments exhibit toxicity and certain patients may develop resistance. Thus, less toxic and chemoresistance-reversal agents are required. In the present study, the potential effect of curcumin, a component of Curcuma longa, as a pharmacological co-adjuvant of several chemotherapeutic agents against ALL, including prednisone, 6-mercaptopurine, dexamethasone, cyclophosphamide, l-asparaginase, vincristine, daunorubicin, doxorubicin, methotrexate and cytarabine, was investigated in the REH ALL cell line cultures treated in combination with chemotherapeutic agents and curcumin. The results of cell viability, gene expression and activation of NF-κB and caspase 3 indicated that curcumin potentiates the anticancer effects of the aforementioned chemotherapeutic agents in the REH ALL cell line. Following treatment with the above chemotherapeutic agents, curcumin enhanced caspase-3 activation and downregulated nuclear factor-kappa B (NF-κB) activation. Curcumin also downregulated the oxidative stress induced by certain chemotherapies. Notably, curcumin did not affect the gene expression of cell survival proteins such as B-cell lymphoma (Bcl)-2, Bcl-extra large, survivin, c-Myc and cyclin D1, which are regulated by the NF-κB transcription factor. In conclusion, curcumin has the potential to improve the effect of chemotherapeutic agents against ALL.

Transient abnormal myelopoiesis (TAM) raises the risk for acute myeloid leukemia of Down syndrome (DS) (ML‐DS), and both are related to GATA1 pathogenic variants. Here, we analyzed which findings on complete blood count (CBC) are associated with TAM in a cohort of neonates with DS screened for GATA1 pathogenic variants. The CBCs were compared among 70 newborns with DS, including 16 patients (22.9%) with TAM (cases), and 54 patients (77.1%) without TAM (controls). TAM was defined as peripheral circulating blasts (PCBs) ≥ 1%. PCR and direct sequencing were used to screen DNA samples from peripheral blood for GATA1 exon 2 mutations. Multivariate logistic regression analyses determined that the mean count of lymphocytes was significantly higher in DS infants with TAM (p = .035) and that lymphocytosis confers a risk for TAM (adjusted odds ratio = 7.23, 95% confidence intervals: 2.02–25.92). Pathogenic variants of GATA1 were identified in 2 of 70 analyzed DS neonates (2.9%), of which one had ML‐DS and another had an asymptomatic TAM. Among those DS infants with TAM, the GATA1 pathogenic variant detection was 12.5%. Our results indicated that lymphocytosis is associated with TAM in neonates with DS. However, since not all infants with an abnormal CBC had TAM, and not all infants with TAM had GATA1 pathogenic variants, we emphasize that only the search for GATA1 pathogenic variants allows the proper identification of the subgroup of DS infants with a real increasing in risk for ML‐DS.

Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph + ALL), is characterized by the t(9;22)(q34q11) that generates the BCR-ABL protein with uncontrolled tyrosine kinase activity. Recently, a connection between BCR-ABL signaling with NF-κB activation mediated by CK2 has been hypothesized. Approximately 95% of patients with Ph + ALL have the BCR-ABLp190 isoform, which causes aggressive leukemia with a high rate of chemotherapy resistance. Therefore, the use of compounds that could improve the efficacy of chemotherapy drugs is of particular interest. Curcumin is an active chemical in turmeric with antineoplastic potential; it regulates protein-kinases by modulating downstream molecular pathways. The present study evaluated the effect of curcumin in combination with the chemotherapeutic drugs vincristine, imatinib and daunorubicin in the human OP-1 cell line. Several doses of the chemotherapy drugs were examined, and the effects were evaluated following 12, 24 and 48 h of exposure. The interaction between the chemotherapy drugs and curcumin was determined by the dose-effect curve, which generated a combination index (CI); these data were represented in isobolograms. In addition, the individual effect of each drug was compared with its effect in combination with curcumin on cell viability, apoptosis degree, NF-κB activation and gene expression changes. The present study observed that curcumin potentiates the efficacy of vincristine and imatinib, generating an additive/synergistic effect in a dose-and time-dependent manner. These combinations significantly increased the apoptosis degree, decreased the activation of NF-κB and the expression of its regulated genes. Conversely treatment with daunorubicin + curcumin combination produced an antagonistic/additive effect in a dose-dependent manner, and this combination significantly increased the apoptosis degree. However, this effect seems not to be associated with NF-κB activity, as no significant changes were observed in its activation or in the expression of the genes that it regulates. The results of the present study demonstrate that curcumin may be used as an adjuvant agent for chemotherapy in patients with Ph + ALL.