Curcumin Induces Apoptosis by Inhibiting the Expression of IAPs in Human Precursor B-Acute Lymphoblastic Leukemic (PreB-ALL) Cells.

Abstract Acute lymphoblastic leukemia (ALL) is the most common cancer of childhood resulting from the clonal proliferation of lymphoid precursors with arrested maturation. Chemotherapy can induce complete remission in more than 95% of cases of childhood ALL and achieve long-term survival in 70–80% of cases. However, ALL with the t(9:22) BCR-ABL translocation or Philadelphia chromosome (Ph1) are still highly resistant to chemotherapy from the onset. Thus, new therapeutic approaches are required to improve their prognosis. Characterization of the growth requirement of ALL cells suggest that these cancers are dependent on various cytokines via paracrine and/or autocrine mechanism in which the JAK family of proteins are closely implicated. Accordingly, tyrosine kinase inhibitors against JAKs are expected to become a new class of anti-tumor agents against these cancers. Curcumin has been shown to inhibit JAK-STAT pathway in a variety of hematological malignancies including multiple myeloma and primary effusion lymphomas. We therefore sought to determine whether curcumin suppresses the growth of acute lymphoblastic leukemia. We tested a panel of preB-ALL cell lines with various translocations after treatment with different doses of curcumin. The cell lines included REH (t12:21), RS4:11 (t4:11), 697 (t1:19) and SupB15(t9:22). Cell viability decreased in a concentration-dependent manner in 697, REH and RS4:11 with curcumin (0–40mM) whereas only minimal changes in viability was detected in SupB15. Curcumin induced apoptosis in all preB-ALL cell lines except SupB15 that was found to be refractory to curcumin treatment. Curcumin induced apoptosis via truncation of BID, loss of mitochondrial potential as determined by JC1 staining with subsequent release of cytochrome c from the mitochondria, and activation of caspase 3 and PARP. Curcumin treatment also caused the down-regulation of the IAPs, cIAP1 and XIAP. All these events occured in the sensitive cell lines 697, REH and RS4:11, however, in SupB15, curcumin failed to inhibit the expression of cIAP1 and XIAP and remained refractory to treatment. These results suggest that the IAPs may play an important role in curcumin induced apoptosis in preB-ALL cells. Altogether, our findings suggests a novel function for curcumin, acting as a growth suppressor of most preB-ALL cells and inducing apoptosis via down-regulation of IAPs. Therefore, curcumin may have a future therapeutic role in preB-ALL and possibly other malignancies.

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Alantolactone inhibits cell autophagy and promotes apoptosis via AP2M1 in acute lymphoblastic leukemia

Cancer Cell International ◽

10.1186/s12935-020-01537-9 ◽

2020 ◽

Vol 20 (1) ◽

Author(s):

Ce Shi ◽

Wenjia Lan ◽

Zhenkun Wang ◽

Dongguang Yang ◽

Jia Wei ◽

...

Keyword(s):

Acute Lymphoblastic Leukemia ◽

Tumor Growth ◽

Cell Lines ◽

Lymphoblastic Leukemia ◽

Dependent Manner ◽

Nude Mouse Model ◽

Hematopoietic Malignancy ◽

Induced Apoptosis ◽

Anti Tumor Activity

Abstract Background Acute lymphoblastic leukemia (ALL) is an aggressive hematopoietic malignancy that is most commonly observed in children. Alantolactone (ALT) has been reported to exhibit anti-tumor activity in different types of cancer. The aim of the present study was to investigate the anti-tumor activity and molecular mechanism of ALT in ALL. Methods ALL cell lines were treated with 1, 5 and 10 μM ALT, and cell viability was assessed using an MTT assay and RNA sequencing. Flow cytometry, JC-1 staining and immunofluorescence staining assays were used to measure cell apoptosis and autophagy. Additionally, western blot analysis was used to detect expression of apoptosis and autophagy related proteins. Finally, the effects of ALT on tumor growth were assessed in a BV173 xenograft nude mouse model. Results ALT inhibited the proliferation of ALL cells in a dose-dependent manner. Additionally, it was demonstrated that ALT inhibited cell proliferation, colony formation, autophagy, induced apoptosis and reduced tumor growth in vivo through upregulating the expression of adaptor related protein complex 2 subunit mu 1 (AP2M1). Moreover, the autophagy activator rapamycin, attenuated the pro-apoptotic effects of ALT on BV173 and NALM6 cell lines. Overexpression of AP2M1 decreased the expression of Beclin1 and the LC3-II/LC3-1 ratio, and increased p62 expression. Knockdown of Beclin1 increased the levels of bax, cleaved caspase 3 and cytochrome C, and decreased bcl-2 expression. Conclusions The present study demonstrated that ALT exerts anti-tumor activity through inducing apoptosis and inhibiting autophagy by upregulating AP2M1 in ALL, highlighting a potential therapeutic strategy for treatment of ALL.

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Anti-Leukemic Property of Sulphoraphane In Precursor B Cell Acute Lymphoblastic Leukemia

Blood ◽

10.1182/blood.v116.21.3974.3974 ◽

2010 ◽

Vol 116 (21) ◽

pp. 3974-3974

Author(s):

Koramit Suppipat ◽

Xiao Zhu ◽

Chun Shik Park ◽

H. Daniel Lacorazza

Keyword(s):

Acute Lymphoblastic Leukemia ◽

B Cells ◽

B Cell ◽

Cell Line ◽

Cell Lines ◽

Lymphoblastic Leukemia ◽

Annexin V ◽

Dependent Manner ◽

Carcinogenic Activity ◽

Childhood All

Abstract Abstract 3974 Acute lymphoblastic leukemia (ALL) is the most common form of hematologic malignancy in children. In spite of significant advances achieved in the treatment of childhood ALL, one fifth of these patients still relapse after the standard treatment. Moreover, relapse ALL is the second most common cause of cancer-related deaths in children. The development of novel therapies is prevented by a limited understanding of the exact pathobiology. There are emerging evidences that the transcription factor KLF4 has a tumor suppressor property in ALL. Recently, a gene expression classifier study in pediatric precursor B-cell ALL (pre-B ALL) showed that KLF4 expression was significantly reduced in high risk ALL patients with positive MRD after induction. This finding suggests a possible role of this cell cycle inhibitor on the development, expansion and drug-resistant of leukemic cells. Several studies demonstrate that overexpression of KLF4 in normal B cells and BCR transformed B cells show increased apoptosis and reduced proliferation. Furthermore, we recently described that KLF4 inhibits proliferation of naïve lymphocytes by activating p21 (Yamada, et al, 2009). Sulphoraphane (SF; 4-methylsulfonylbutyl isothiocyanate) is a dietary compound derived from Cruciferae vegetables with anti-carcinogenic activity in colon cancer by upregulating KLF4 and p21 among other genes. Thus, we hypothesized that SF could also exhibit anti-leukemic activity in human-derived acute lymphoblastic leukemia cells via the activation of KLF4. The pre-B ALL cell lines (Nalm6, REH, RS-4, SUP-B15) and an EBV transformed B cell line were treated with different concentrations of SF (0-40 μM) for 24–48 hours. Then, cell number was estimated using an ATP-based viability method. Flow cytometric analysis of ANNEXIN-V/7-AAD binding as well as CFSE dilution was used to measure apoptosis and proliferation respectively. We found that SF induced cytotoxicity in Nalm-6, REH and RS-4 cell lines in a dose and time dependent manner. This cytotoxic effect was less pronounced in EBV-transformed B cell line. SF treatment led to increased ANNEXIN-V and 7-AAD positive cells (82% apoptotic cells in SF-treated versus 9% in DMSO control). Further, SF-treated cells displayed significantly less proliferation in comparison to DMSO controls thus suggesting that SF inhibits cellular proliferation. Preliminary data also suggest that SF-mediated apoptosis is caused by upregulation of KLF4. In conclusion, Sulphoraphane exhibits an anti-leukemic property by inducing apoptosis and abrogating proliferation in pre-B ALL cell lines. Thus, sulphoraphane could potentially be used as an adjunctive therapy in a subgroup of pre-B ALL patients who have decreased expression of KLF4. Disclosures: No relevant conflicts of interest to declare.

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Childhood Acute Lymphoblastic Leukemia: Progress Through Collaboration

Journal of Clinical Oncology ◽

10.1200/jco.2014.59.1636 ◽

2015 ◽

Vol 33 (27) ◽

pp. 2938-2948 ◽

Cited By ~ 371

Author(s):

Ching-Hon Pui ◽

Jun J. Yang ◽

Stephen P. Hunger ◽

Rob Pieters ◽

Martin Schrappe ◽

...

Keyword(s):

Acute Lymphoblastic Leukemia ◽

Children And Adolescents ◽

English Literature ◽

Lymphoblastic Leukemia ◽

Philadelphia Chromosome ◽

Study Groups ◽

Term Survival ◽

Childhood All ◽

Collaborative Studies ◽

The Impact

Purpose To review the impact of collaborative studies on advances in the biology and treatment of acute lymphoblastic leukemia (ALL) in children and adolescents. Methods A review of English literature on childhood ALL focusing on collaborative studies was performed. The resulting article was reviewed and revised by the committee chairs of the major ALL study groups. Results With long-term survival rates for ALL approaching 90% and the advent of high-resolution genome-wide analyses, several international study groups or consortia were established to conduct collaborative research to further improve outcome. As a result, treatment strategies have been improved for several subtypes of ALL, such as infant, MLL-rearranged, Philadelphia chromosome–positive, and Philadelphia chromosome–like ALL. Many recurrent genetic abnormalities that respond to tyrosine kinase inhibitors and multiple genetic determinants of drug resistance and toxicities have been identified to help develop targeted therapy. Several genetic polymorphisms have been recognized that show susceptibility to developing ALL and that help explain the racial/ethnic differences in the incidence of ALL. Conclusion The information gained from collaborative studies has helped decipher the heterogeneity of ALL to help improve personalized treatment, which will further advance the current high cure rate and the quality of life for children and adolescents with ALL.

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Alantolactone inhibits cell autophagy and promotes apoptosis via AP2M1 in acute lymphoblastic leukemia

10.21203/rs.3.rs-21650/v3 ◽

2020 ◽

Author(s):

Ce Shi ◽

Wenjia Lan ◽

Zhenkun Wang ◽

Dongguang Yang ◽

Jia Wei ◽

...

Keyword(s):

Acute Lymphoblastic Leukemia ◽

Tumor Growth ◽

Cell Lines ◽

Lymphoblastic Leukemia ◽

Dependent Manner ◽

Nude Mouse Model ◽

Hematopoietic Malignancy ◽

Induced Apoptosis ◽

Anti Tumor Activity

Abstract Background: Acute lymphoblastic leukemia (ALL) is an aggressive hematopoietic malignancy that is most commonly observed in children. Alantolactone (ALT) has been reported to exhibit anti-tumor activity in different types of cancer. The aim of the present study was to investigate the anti-tumor activity and molecular mechanism of ALT in ALL. Methods: ALL cell lines were treated with 1, 5 and 10 μM ALT, and cell viability was assessed using an MTT assay and RNA sequencing. Flow cytometry, JC-1 staining and immunofluorescence staining assays were used to measure cell apoptosis and autophagy. Additionally, western blot analysis was used to detect expression of apoptosis and autophagy related proteins. Finally, the effects of ALT on tumor growth were assessed in a BV173 xenograft nude mouse model. Results: ALT inhibited the proliferation of ALL cells in a dose-dependent manner. Additionally, it was demonstrated that ALT inhibited cell proliferation, colony formation, autophagy, induced apoptosis and reduced tumor growth in vivo through upregulating the expression of adaptor related protein complex 2 subunit mu 1 (AP2M1). Moreover, the autophagy activator rapamycin, attenuated the pro-apoptotic effects of ALT on BV173 and NALM6 cell lines. Overexpression of AP2M1 decreased the expression of Beclin1 and the LC3-II/LC3-1 ratio, and increased p62 expression. Knockdown of Beclin1 increased the levels of bax, cleaved caspase 3 and cytochrome C, and decreased bcl-2 expression. Conclusions: The present study demonstrated that ALT exerts anti-tumor activity through inducing apoptosis and inhibiting autophagy by upregulating AP2M1 in ALL, highlighting a potential therapeutic strategy for treatment of ALL.

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TEL-AML1 Fusion Transcript in Relapsed Childhood Acute Lymphoblastic Leukemia

Blood ◽

10.1182/blood.v91.5.1716 ◽

1998 ◽

Vol 91 (5) ◽

pp. 1716-1722 ◽

Cited By ~ 13

Author(s):

Karlheinz Seeger ◽

Hans-Peter Adams ◽

Dirk Buchwald ◽

Birgit Beyermann ◽

Bernhard Kremens ◽

...

Keyword(s):

Bone Marrow ◽

Acute Lymphoblastic Leukemia ◽

Lymphoblastic Leukemia ◽

Prognostic Significance ◽

Philadelphia Chromosome ◽

Fusion Transcript ◽

Childhood Acute Lymphoblastic Leukemia ◽

Long Term Results ◽

Childhood All ◽

Cryptic Translocation

Abstract The cryptic translocation t(12;21)(p13;q22) has been recently recognized as the most common genetic rearrangement in B-lineage childhood acute lymphoblastic leukemia (ALL). The resulting fusion transcript, termed TEL-AML1, has been associated with an excellent prognosis at initial ALL diagnosis. Hence, we postulated that the incidence of TEL-AML1 fusion should be lower in patients with ALL relapse. To address this assumption and to investigate the prognostic significance of TEL-AML1 expression in relapsed childhood ALL, bone marrow samples of 146 children were analyzed by reverse-transcriptase (RT)-polymerase chain reaction (PCR). All children were treated according to Berlin-Frankfurt-Münster (BFM) ALL relapse trial protocols (ALL-REZ BFM 90-96). Their clinical features and outcome were compared with those of 262 patients who could not be tested due to lack of bone marrow samples. Thirty-two of 146 children with relapsed ALL were TEL-AML1–positive. Four of the negative patients had T-lineage and nine Philadelphia chromosome (Ph1)-positive leukemia. Thus, the incidence ofTEL-AML1 in relapsed Ph1-negative, B-cell precursor ALL is 32 of 133 (24%). The 32 TEL-AML1–positive and 101 negative patients differed significantly with respect to duration of last remission (42.5 v 27 months; P = .0001) and age at initial diagnosis (53.5 v 74 months;P = .0269). At a median follow-up time of 21.5 months, children positive for TEL-AML1 had a significantly (P = .0011) higher probability of event-free survival (EFS; 0.79 v 0.33). The predominant majority of patients had been treated for initial ALL according to German multicenter BFM (108 of 133) or Cooperative ALL study group (CoALL) (19 of 133) frontline protocols. The comparison of tested and not-tested (N = 262) patients showed no significant difference.TEL-AML1 positivity predicted a favorable short-term outcome; long-term results are unknown. Screening for TEL-AML1 should become routine at relapse diagnosis and might be used for therapy stratification in future trials.

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Treatment Selection for Philadelphia Chromosome-Positive Acute Lymphoblastic Leukemia in the Era of Tyrosine Kinase Inhibitors

Chemotherapy ◽

10.1159/000501061 ◽

2019 ◽

Vol 64 (2) ◽

pp. 81-93 ◽

Cited By ~ 2

Author(s):

Yingying Ma ◽

Quanchao Zhang ◽

Peiyan Kong ◽

Jingkang Xiong ◽

Xi Zhang ◽

...

Keyword(s):

Acute Lymphoblastic Leukemia ◽

Tyrosine Kinase ◽

Tyrosine Kinase Inhibitors ◽

Kinase Inhibitors ◽

Lymphoblastic Leukemia ◽

Philadelphia Chromosome ◽

Molecular Response ◽

Term Survival ◽

Hematopoietic Stem ◽

Philadelphia Chromosome Positive

With the advent of tyrosine kinase inhibitors (TKIs), the treatment of Philadelphia chromosome-positive (Ph+) acute lymphoblastic leukemia (ALL) has entered a new era. The efficacy of TKIs compared with other ALL treatment options is emphasized by a rapid increase in the number of TKI clinical trials. Subsequently, the use of traditional approaches, such as combined chemotherapy and even allogeneic hematopoietic stem cell transplantation (allo-HSCT), for the treatment of ALL is being challenged in the clinic. In light of the increased use of TKIs in the clinic, several questions have been raised. First, is it necessary to use intensive chemotherapy during the induction course of therapy to achieve a minimal residual disease (MRD)-negative status? Must a patient reach a complete molecular response/major molecular response before receiving allo-HSCT? Does MRD status affect long-term survival after allo-HSCT? Is auto-HSCT an appropriate alternative for allo-HSCT in those Ph+ ALL patients who lack suitable donors? Here, we review the recent literature in an attempt to summarize the current status of TKI usage in the clinic, including several new therapeutic approaches, provide answers for the above questions, and speculate on the future direction of TKI utilization for the treatment of Ph+ ALL patients.

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Activation of the JNK Pathway Mediates Chemoresistance in T-Cell Acute Lymphoblastic Leukemia by Phosphorylation and Proteosomal Degradation of BimEL.

Blood ◽

10.1182/blood.v110.11.2372.2372 ◽

2007 ◽

Vol 110 (11) ◽

pp. 2372-2372

Author(s):

Kam Tong Leung ◽

Karen Kwai Har Li ◽

Samuel Sai Ming Sun ◽

Paul Kay Sheung Chan ◽

Yum Shing Wong ◽

...

Keyword(s):

Acute Lymphoblastic Leukemia ◽

T Cell ◽

Cytochrome C ◽

Cell Lines ◽

Caspase 3 ◽

Lymphoblastic Leukemia ◽

Chemotherapeutic Agents ◽

Jnk Pathway ◽

Cell Acute Lymphoblastic Leukemia ◽

Induced Apoptosis

Abstract Despite progress in the development of effective treatments against T-cell acute lymphoblastic leukemia (T-ALL), about 20% of patients still exhibit poor response to the current chemotherapeutic regimens and the cause of treatment failure in these patients remains largely unknown. In this study, we aimed at finding mechanisms that drive T-ALL cells resistant to chemotherapeutic agents. By screening etoposide sensitivity of a panel of T-ALL cell lines using DNA content and PARP cleavage as apoptosis markers, we identified an apoptosis-resistant cell line, Sup-T1. Western blot analysis and caspase activity assay showed that Sup-T1 cells were deficient in etoposide-induced activation of caspase-3 and caspase-9. In addition, mitochondrial cytochrome c release was not evident in etoposide-treated Sup-T1 cells. However, addition of exogenous cytochrome c in cell-free apoptosis reactions induced prominent caspase-3 activation, indicating that the chemoresistance observed in Sup-T1 cells was due to its insusceptibility to the drug-induced mitochondrial alterations. Analysis of the basal expression of the Bcl-2 family proteins revealed that the levels of Bcl-2 was higher in Sup-T1 cells, while Bax and BimEL levels were lower, when compared to etoposide-sensitive T-ALL cell lines. Gene silencing using antisense oligonucleotide to Bcl-2 and overexpression of Bax did not resensitize cells to etoposide-induced apoptosis. On the contrary, transient transfection of BimEL into Sup-T1 cells significantly restored etoposide sensitivity. Further experiments revealed that the lack of BimEL expression in Sup-T1 cells was due to the rapid degradation of newly-synthesized BimEL by the proteosomal pathway, as treatment of Sup-T1 cells with a proteosome inhibitor significantly restored the protein level of BimEL. Moreover, treatment with proteosome inhibitor resulted in mobility shift of BimEL, which was sensitive to phosphatase digestion. Furthermore, treatment of Sup-T1 cells with JNK inhibitor resulted in accumulation of BimEL, and pretreatment with JNK inhibitor restored sensitivity of Sup-T1 cells to etoposide-induced apoptosis, indicating that constitutive activation of the JNK pathway in Sup-T1 cells was responsible for promoting BimEL phosphorylation, and this may serve as a signal targeting BimEL to the proteosome for degradation. Altogether, our findings provide the first evidence that JNK activation correlates inversely with BimEL level by promoting its phosphorylation and degradation. This, in turn, reduces the sensitivity of T-ALL cells to chemotherapeutic agents.

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Janus Kinase (JAK)-2 Does Not Play a Role in Bcr-Abl Signaling in Philadelphia Chromosome (Ph)-Positive (p190) Acute Lymphoblastic Leukemia (ALL) Cells.

Blood ◽

10.1182/blood.v110.11.4241.4241 ◽

2007 ◽

Vol 110 (11) ◽

pp. 4241-4241

Author(s):

Stefan H. Faderl ◽

Quin Van ◽

Patricia E. Koch ◽

David M. Harris ◽

Inbal Hallevi ◽

...

Keyword(s):

Cell Lines ◽

Lymphoblastic Leukemia ◽

Philadelphia Chromosome ◽

Janus Kinase ◽

Myelogenous Leukemia ◽

Dependent Manner ◽

Western Immunoblotting ◽

Gm Csf ◽

Dose Dependent

Abstract Novel immunochemotherapy regimens combined with imatinib mesylate (IA) have significantly improved treatment outcome of Ph+ ALL. Nevertheless, most adult patients with Ph+ ALL relapse and succumb to their disease. Recent reports suggested that Jak-2 is engaged in the signaling of Bcr-Abl in chronic myelogenous leukemia (CML) cells. Because Jak-2 inhibitory agents are currently investigated in clinical trials, we sought to explore the role of Jak-2 in the signaling of Bcr-Abl in Ph+ ALL assuming that inhibition of Jak-2 might be beneficial in the treatment of Ph+ ALL. To do this, we used our Ph+ (p190) ALL cell lines Z-119 and Z-181 (Estrov et al. J Cell Physiol166: 618, 1996). We chose these cells because in both lines Jak-2 can be activated. Both Z-119 and Z-181 cells express granulocyte-macrophage colony-stimulating factor (GM-CSF) receptors and GM-CSF activates Jak-2 and stimulates the proliferation of both cell lines. Using a clonogenic assay, we found that IA inhibited the proliferation of these cells at concentrations ranging from 50 to 500 nM. Because Bcr-Abl was found to activate the signal transducer and activator of transcription (STAT)-5 in CML cells, we used Western immunoblotting and found that IA inhibited the phosphorylation (p) of STAT5 in a dose-dependent manner in Ph+ ALL cells. To test whether JAk-2 plays a role in Bcr-Abl (p190) signaling we incubated Z-181 cells for 4 hours with or without 50, 100, 250, and 500 nM IA, extracted cellular protein and immunoprecipitated total STAT5 protein. Then, using Western immunoblotting we detected the Bcr-Abl p190 protein in all STAT5 immunoprecipitates and by using specific pSTAT5 antibodies, we demonstrated that IA induced a dose-dependent reduction in the levels of pSTAT5, but not of p190 protein, suggesting that the p190 Bcr-Abl kinase binds to and activates STAT5. Remarkably, neither Jak-2 nor pJak-2 was detected in either immunoprecipitate. To further delineate the role of Jak-2 in Bcr-Abl signaling we extracted protein from Z-181 cells and immunoprecipitated Jak-2. Neither Bcr-Abl nor STAT5 was detected in these immunoprecipitates, confirming that Jak-2 does not bind Bcr-Abl p190 protein and does not participate in the activation of STAT5. Taken together, our data suggest that Bcr-Abl (p190) binds and phosphorylates STAT5 whereas, Jak-2 is not engaged in Bcr-Abl (p190) signaling in Ph+ ALL cells.

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Induction of Apoptosis In Imatinib-Resistant BCR-ABL1-Positive Leukemia Cell Lines by Bortezomib

Blood ◽

10.1182/blood.v116.21.4469.4469 ◽

2010 ◽

Vol 116 (21) ◽

pp. 4469-4469

Author(s):

Hilmar Quentmeier ◽

Sonja Eberth ◽

Julia Romani ◽

Margarete Zaborski ◽

Hans G. Drexler

Keyword(s):

Cell Lines ◽

Kinase Inhibitor ◽

Conflicts Of Interest ◽

Lymphoblastic Leukemia ◽

Philadelphia Chromosome ◽

Leukemia Cell ◽

Resistant Cell ◽

Imatinib Resistance ◽

Imatinib Resistant ◽

Induced Apoptosis

Abstract Abstract 4469 The BCR-ABL1 translocation occurs in chronic myeloid leukemia (CML) and in 25% of cases with acute lymphoblastic leukemia (ALL). We screened a panel of BCR-ABL1 positive cell lines to find models for imatinib-resistance studies. Five of 19 BCR-ABL1 positive cell lines were resistant to imatinib-induced apoptosis (KCL-22, MHH-TALL1, NALM-1, SD-1, SUP-B15). None of the five resistant cell lines carried mutations in the kinase domain of BCR-ABL1 and – consequently – all also showed resistance to the second generation kinase inhibitors, nilotinib or dasatinib. All Philadelphia chromosome (Ph)-positive cell lines demonstrated constitutive phosphorylation of STAT5 and S6. Imatinib induced dephosphorylation of both BCR-ABL1 downstream effectors in responsive cell lines, but - remarkably – induced dephosphorylation of STAT5 in resistant cell lines as well. By administering well-described signalling pathway inhibitors we were able to show that activation of mTOR complex 1 was responsible for the constitutive S6 phosphorylation of imatinib-resistant cells. Neither BCR-ABL1 nor Src kinases or Ras/Rac-GTPases underlie tyrosine kinase inhibitor resistance in these cell lines. In conclusion, none of the five TKI-resistant cell lines showed aberrant activation of previously-described oncogenic pathways which would explain their resistance. These findings raise the question whether these cell lines might help to find a novel – alternative – explanation for TKI resistance. Interestingly, the proteasome inhibitor bortezomib induced apoptosis in TKI-resistant and –sensitive Ph+ cell lines. Bortezomib is being used for the treatment of multiple myeloma. Our findings support the notion that bortezomib might also be useful for the treatment of imatinib-resistant CML. Disclosures: No relevant conflicts of interest to declare.

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Design of the Hallmarq Trial, a Phase 3 Study of Vincristine Sulfate Liposome Injection (VSLI, Marqibo®) in Adults with Newly Diagnosed, Philadelphia Chromosome Negative Acute Lymphoblastic Leukemia

Blood ◽

10.1182/blood.v120.21.4300.4300 ◽

2012 ◽

Vol 120 (21) ◽

pp. 4300-4300

Author(s):

Steven R. Deitcher ◽

Jeffrey A. Silverman

Keyword(s):

Acute Lymphoblastic Leukemia ◽

Lymphoblastic Leukemia ◽

Philadelphia Chromosome ◽

Pharmacokinetic Parameters ◽

Multiple Time ◽

Phase 2 ◽

Newly Diagnosed ◽

Phase 3 ◽

Childhood All ◽

Free Survival

Abstract Abstract 4300 Background: Adult acute lymphoblastic leukemia (ALL) is a lethal and fulminant disease and one distinct from childhood ALL. There are approximately 2400 new cases per year in the US; approximately 80% of these will be Philadelphia chromosome (Ph) negative. Despite remarkable success in treatment of childhood and adolescent ALL, adult ALL patients are underserved by existing treatment options as reflected by the poor survival rates and extremely poor outcomes in the relapsed setting. Complete response (CR) rates in the front-line setting range from 90% in patients <30 years old to 57% in patients >60 years old and 3-year disease free survival ranges from 47% to 12% respectively. The unmet medical need in adult ALL is most pronounced in those age 60 and older. VSLI was recently granted accelerated FDA approval as a single-agent for the treatment of adults with advanced, relapsed and refractory Ph-negative ALL and has successfully completed a Phase 2 trial as a component of multi-agent therapy. Trial Design: HALLMARQ (NCT01439347) is a Phase 3, multi-national, randomized study to evaluate the substitution of VSLI for standard vincristine (VCR) in the induction, consolidation, and maintenance phases of combination chemotherapy in the treatment of patients ≥ 60 years old with newly diagnosed Ph-negative ALL. The chemotherapy “backbone” utilized in this trial is modified from the Cancer and Leukemia Group B 8811 protocol. Asparaginase product usage is optional. The total duration of protocol-specified therapy is up to 24 months. VCR is dosed at 1.4 mg/m2 with a per dose cap at 2 mg. VSLI is dosed at 2.25 mg/m2without a dose cap. A protocol-specified dose reduction algorithm applicable to both VSLI and VCR will be used to minimize Grade 3 neurotoxicity while also facilitating continued dosing. Growth factors (e.g., granulocyte colony-stimulating factor) and bowel regimens (e.g., daily stool softener) are recommended and will be prescribed according to investigator preference and institutional guidelines. The primary endpoint is overall survival (OS) and the study is powered for superiority. Secondary endpoints include remission rate, overall response rate, event-free survival, and safety and tolerability. Minimal residual disease (MRD) at multiple time points and pharmacokinetic parameters are being assessed. Conclusion: The HALLMARQ Trial will provide new insights into the frontline treatment of ALL in adults ≥60 years old as well as confirm the clinical benefit of VSLI monotherapy demonstrated in the Phase 2 RALLY Study that supported the initial product approval. HALLMARQ is based on a Special Protocol Assessment with the FDA and is currently enrolling. *On behalf of the HALLMARQ investigators. Disclosures: Deitcher: Talon Therapeutics: Employment, Equity Ownership. Silverman:Talon Therapeutics: Employment.

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