Human SIRT1 is an enzyme that deacetylates the p53 tumor suppressor protein.It has been suggested to modulate p53-dependent functions including DNA damage-induced cell death.Sirtuins are nicotinamide adenine dinucleotide dependent class III histone deacetylase proteins that play a crucial role in several cellular processes, including DNA repair, apoptosis, and lifespan.In this study, we investigated the relationship between sirtinols and apoptosis mechanism at leukemic cells.For this, we applied sirtinol to K-562 (chronic myeloid leukemia) and Jurkat (acute T-cell leukemia) cell lines at different dilutions in cell culture conditions.And Cdna isolated patient RNA samples, after that Caspase3, Bax, Bcl2 expression performed with used qRT-PCR technique and cells were stained by Annexin V method.According to the results of research, we identified that Sirtinol dilutions were increased in both K-562 and Jurkat, while the number of living cells was decreasing, the number of dead cells increased at 50 μM dilution.Sirtinol, an HDAC inhibitor in the direction of these results, has been observed to be a drug that can be effective in the treatment of CML as well as T-ALL.

Glucocorticoids have been used in chemotherapy regimens of leukemia for their lymphocytic effect. Glucocorticoid resistances (GC) remain as an important problem and the exact mechanism has not been elucidated. Many studies have been reported describing the relation between response and Glucocorticoid Receptors α/β (GR α/β) expression in childhood leukemia. In present study aimed to determine expression levels of glucocorticoid receptors and to evaluate the relationship with clinical parameters and development of glucocorticoid resistance in children with acute leukemia. To test this hypothesis, GRα/β messenger-RiboNucleic Acid (m-RNA) expression levels were determined in 13 children wtih acute leukemia patients. This study ‘results reported that GRβ expression levels were high at leukemia. The results in this article seem to be the first screening results of the GRα/β m-RNA expression levels studied by quantitative Real Time Polymerase Chain Reaction (qRTPCR) in Turkish acute leukemia patients. The cause of GC resistance in childhood leukemia is largely unknown. The clinical glucocorticoid resistance positivity and the GRα/β ratio may be effective in leading leukemia in glucocorticoid resistance.

Copyright: © 2016 Akin DF, et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. *Corresponding author: Dilara Fatma Akin, Cancer Research and Genetics Laboratory, Losante Children’s and Adult Hospital, Ankara, Turkey, Tel: +905363026816; E-mail: dilarafatmaakin@gmail.com

Retinoids have been implicated as pharmacological agents for the prevention and treatment of various types of cancers, including breast cancers. We analyzed 27 newly synthesized retinoids for their bioactivity on breast, liver, and colon cancer cells. Majority of the retinoids demonstrated selective bioactivity on breast cancer cells. Retinoid 17 had a significant inhibitory activity (IC50 3.5 μM) only on breast cancer cells while no growth inhibition observed with liver and colon cancer cells. The breast cancer selective growth inhibitory action by retinoid 17 was defined as p21-dependent cell death, reminiscent of senescence, which is an indicator of targeted receptor mediated bioactivity. A comparative analysis of retinoid receptor gene expression levels in different breast cancer cells and IC50 values of 17 indicated the involvement of Retinoid X receptors in the cytotoxic bioactivity of retinoid 17 in the senescence associated cell death. Furthermore, siRNA knockdown studies with RXRγ induced decrease in cell proliferation. Therefore, we suggest that retinoid derivatives that target RXRγ, can be considered for breast cancer therapies.

BACKGROUND:CD22 is expressed on the surface of B-cell lineage cells from the early progenitor stage of pro-B cell until terminal differentiation to mature B cells. It plays a role in signal transduction and as a regulator of B-cell receptor signaling in B-cell development.OBJECTIVES:We aimed to screen exons 9-14 of the CD22 gene, which is a mutational hot spot region in B-precursor acute lymphoblastic leukemia (pre-B ALL) patients, to find possible genetic variants that could play role in the pathogenesis of pre-B ALL in Turkish children.METHODS:This study included 109 Turkish children with pre-B ALL who were diagnosed at Losante Hospital for Children with Leukemia. Genomic DNA was extracted from both peripheral blood and bone marrow leukocytes. Gene amplification was performed with PCR, and all samples were screened for the variants by single strand conformation polymorphism. Samples showing band shifts were sequenced on an automated sequencer.RESULTS:In our patient group a total of 9 variants were identified in the CD22 gene by sequencing: a novel variant in intron 10 (T2199G); a missense variant in exon 12; 5 intronic variants between exon 12 and intron 13; a novel intronic variant (C2424T); and a synonymous in exon 13. Thirteen of 109 children (11.9%) carried the T2199G novel intronic variant located in intron 10, and 17 of 109 children (15.6%) carried the C2424T novel intronic variant.CONCLUSION:Novel variants in the CD22 gene in children with pre-B ALL in Turkey that are not present, in the Human Gene Mutation Database or NCBI SNP database, were found.

Background: Acute myeloid leukemia (AML) is a heterogeneous clonal disorder in terms of cytogenetic and molecular aberrations. Ten-Eleven-Translocation 2 (TET2), Kirsten rat sarcoma viral oncogene homolog (KRAS), and Casitas B-cell lymphoma (CBL) have an important role pathogenesis of acute myeloid leukemia (AML) and their activated mutations confer proliferative and survival signals. Aim: In this study, we aimed to find possible genetic markers for molecular analysis in childhood AML by screening hot-spot exons of TET2, KRAS, and CBL using Next Generation Sequencing (NGS) analysis. In addition, association between found variants and mutations of Januse Kinase-2 (JAK2) and Fms-Related Tyrosine Kinase (FLT3) were analyzed which are important prognostic risk factors for AML. Methods: Eight patients who were diagnosed with pediatric AML at Losante Pediatric Hematology–Oncology Hospital were included to the study. Hot-spot exons of TET2, KRAS and CBL genes were screened using the NGS method. Furthermore, FLT3-Internal Tandem Duplicate (FLT3-ITD) and JAK2-V617F were analyzed by Real Time Polymerase chain Reaction (Real Time-PCR). Results: In total, we identified 20 variants in studied genes by NGS. In our patient group, 16 variants in the TET2 (seven novel, seven missense and two silent), two variants in the KRAS (one missense and one intronic) and two variants in the CBL (two novel) were found. All of AML patients were found negative for JAK V617 F. Three of the eight patients (37.5%) showed mutations of both FLT3-ITD and TET2, KRAS, CBL. Conclusion: We found novel mutations for TET2, KRAS, and CBL. The detected variants in this article seem to be the first screening results of genes studied by NGS in childhood AML patients. Our results also showed some degree of association between FLT3-ITD and TET2, KRAS, CBL mutations.

Background: Ankaferd Blood Stopper (ABS) is a preparation of plant extracts originally used as a hemostatic agent. It has pleiotropic effects in many cellular processes such as cell cycle regulation, apoptosis, angiogenesis, signal transduction, inflammation, immunologic processes and metabolic pathways as well as hemostatic activity. This unique preparation has been widely investigated for its properties. However there are no studies investigating its action on leukemic cells. Aim: Aim of the study was to examine the ABS action on PAR1 and EPCR in leukemia cells. However, during the experiments, we observed the apoptotic effect of ABS on leukemic cells, particularly Jurkat cells. As a result the mechanism of apoptosis induced by ABS treatment was also explored in the study. Material and method: Two leukemia cell lines, K-562 and Jurkat, were utilized for the study. Expression analyses of PAR1, EPCR and p21 upon ABS treatment were performed by quantitative real time PCR. Annexin V method was used for apoptosis detection. Results: Our results demonstrated that ABS alters PAR1 and EPCR expression in K-562 and Jurkat cells in a time and dose dependent manner. Additionally it was found that ABS treatment induces apoptosis in leukemia cells. Possible involvement of PAR1 and p21 in this apoptotic process was observed in Jurkat cells. Conclusion: This study concludes that depending on the concentration and duration of the application, ABS causes apoptosis by regulating PAR1 and p53-independent p21 involvement in apoptosis stimulation in leukemia cells. The composition of ABS plant extracts might be responsible from the apoptotic effect that was observed. We think that our results could contribute to the development of new treatment for leukemia therapy.

In this study, novel (E)-3-(5-substituted-1H-indol-3-yl)-1-(5,5,8,8-tetramethyl-5,6,7,8-tetrahydronaphthalen-2-yl)prop-2-en-1-one (5(a-e)) derivatives were synthesized and their anticancer effects were determined in vitro. Novel indole retinoid compounds except Se have anti-proliferative capacity in liver, breast and colon cancer cell lines. This anti-proliferative effect was further analyzed in breast cancer cell line panel by using the most potent compound Sa. It was determined that 5a can inhibit proliferation at very low IC50 concentrations in all of the breast cancer cell lines. Here, we present some evidence on apoptotic termination of cancer cell proliferation which may be primarily driven by the inhibition of RXR alpha and, to a lesser extent, RXR gamma. (C) 2012 Elsevier Masson SAS. All rights reserved.

Background: Breast cancer is a remarkably heterogeneous disease. Luminal, basal-like, "normal-like", and ERBB2+ subgroups were identified and were shown to have different prognoses. The mechanisms underlying this heterogeneity are poorly understood. In our study, we explored the role of cellular differentiation and senescence as a potential cause of heterogeneity.Methodology/Principal Findings: A panel of breast cancer cell lines, isogenic clones, and breast tumors were used. Based on their ability to generate senescent progeny under low-density clonogenic conditions, we classified breast cancer cell lines as senescent cell progenitor (SCP) and immortal cell progenitor (ICP) subtypes. All SCP cell lines expressed estrogen receptor (ER). Loss of ER expression combined with the accumulation of p21(Cip1) correlated with senescence in these cell lines. p21(Cip1) knockdown, estrogen-mediated ER activation or ectopic ER overexpression protected cells against senescence. In contrast, tamoxifen triggered a robust senescence response. As ER expression has been linked to luminal differentiation, we compared the differentiation status of SCP and ICP cell lines using stem/progenitor, luminal, and myoepithelial markers. The SCP cells produced CD24+ or ER+ luminal-like and ASMA+ myoepithelial-like progeny, in addition to CD44+ stem/progenitor-like cells. In contrast, ICP cell lines acted as differentiation-defective stem/progenitor cells. Some ICP cell lines generated only CD44+/CD24-/ER-/ASMA-progenitor/stem-like cells, and others also produced CD24+/ER-luminal-like, but not ASMA+ myoepithelial-like cells. Furthermore, gene expression profiles clustered SCP cell lines with luminal A and "normal-like" tumors, and ICP cell lines with luminal B and basal-like tumors. The ICP cells displayed higher tumorigenicity in immunodeficient mice.Conclusions/Significance: Luminal A and "normal-like" breast cancer cell lines were able to generate luminal-like and myoepithelial-like progeny undergoing senescence arrest. In contrast, luminal B/basal-like cell lines acted as stem/progenitor cells with defective differentiation capacities. Our findings suggest that the malignancy of breast tumors is directly correlated with stem/progenitor phenotypes and poor differentiation potential.

Senescence induction could be used as an effective treatment for hepatocellular carcinoma (HCC). However, major senescence inducers (p53 and p16(Ink4a)) are frequently inactivated in these cancers. We tested whether transforming growth factor-beta (TGF-beta) could serve as a potential senescence inducer in HCC. First, we screened for HCC cell lines with intact TGF-beta signaling that leads to small mothers against decapentaplegic (Smad)-targeted gene activation. Five cell lines met this condition, and all of them displayed a strong senescence response to TGF-beta 1 (1-5 ng/mL) treatment. Upon treatment, c-myc was down-regulated, p21(Cip1) and p15(Ink4b) were up-regulated, and cells were arrested at G(1). The expression of p16(Ink4a) was not induced, and the senescence response was independent of p53 status. A short exposure of less than 1 minute was sufficient for a robust senescence response. Forced expression of p21(Cip1) and p15(Ink4b) recapitulated TGF-beta 1 effects. Senescence response was associated with reduced nicotinamide adenine dinucleotide phosphate oxidase 4 (Nox4) induction and intracellular reactive oxygen species (ROS) accumulation. The treatment of cells with the ROS scavenger N-acetyl-L-cysteine, or silencing of the NOX4 gene, rescued p21(Cip1) and p15(Ink4b) accumulation as well as the growth arrest in response to TGF-beta. Human HCC tumors raised in immunodeficient mice also displayed TGF-beta 1 induced senescence. More importantly, peritumoral injection of TGF-beta 1 (2 ng) at 4-day intervals reduced tumor growth by more than 75%. In contrast, the deletion of TGF-beta receptor 2 abolished in vitro senescence response and greatly accelerated in vivo tumor growth. Conclusion: TGF-beta induces p53-independent and p16(Ink4a)-independent, but Nox4-dependent, p21(Cip1)-dependent, p15(Ink4b)-dependent, and ROS-dependent senescence arrest in well-differentiated HCC cells. Moreover, TGF-beta induced senescence in vivo is associated with a strong antitumor response against HCC. (HEPATOLOGY 2010;52:966-974)