Down-Regulation of Bax and Bak in Immuno-Chemotherapy Resistant Non-Hodgkin’s Lymphoma Cells.

Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 4758-4758
Author(s):  
Scott H. Olejniczak ◽  
James L. Clements ◽  
Naveen Bangia ◽  
Francisco J. Hernandez-Ilizaliturri ◽  
Myron S. Czuczman
Keyword(s):  
Cell Death ◽  
B Cell ◽  
Apoptotic Cell ◽  
Acquired Resistance ◽  
Resistant Cell ◽  
Chemotherapeutic Agents ◽  
Down Regulation ◽  
Apoptotic Pathway ◽  
B Cell Homeostasis ◽  
Limited Dilution

Abstract The balance between pro-apoptotic (Bax, Bak) and anti-apoptotic (Bcl-2, Bcl-xL, Mcl-1) Bcl-2 family proteins is essential for the maintenance of B-cell homeostasis. Disruption of this critical balance occurs in the majority of B-cell neoplasms. Clinically, high Bcl-2/Bak and Bcl-2/Bax ratios have been associated with decreased median survival (7.3 years and 3.8 years, respectively) in follicular lymphoma patients1. Recent work in mouse embryonic fibroblasts deficient for the multi-domain pro-apoptotic Bcl-2 family proteins Bax and Bak has shown that they are essential for induction of cell death following apoptotic stimuli that act through the mitochondrial (intrinsic) pathway2. The vast majority of clinically available anti-neoplastic agents, including rituximab, are known to induce cell death via this pathway and therefore likely rely on Bax and/or Bak to exert their anti-tumor effects. Alteration in expression of Bax and/or Bak could therefore underlie acquired resistance to rituximab and chemotherapy in NHL patients. To study the phenomenon of rituximab resistance we developed several rituximab-resistant cell lines (RRCL) that we subsequently showed were also resistant to chemotherapy. RRCL were generated by exposing Raji, SU-DHL-4 and RL cells to escalating doses of rituximab +/− human serum and subsequently cloning by limited dilution. In our present work we studied the efficacy of clinically-applicable chemotherapeutic agents against RRCL. Additionally we studied the intrinsic apoptotic pathway in an attempt to explain shared mechanisms of resistance to chemotherapy and rituximab. We found that RRCL have dramatically reduced levels of both Bax and Bak proteins by Western blot while levels of Bcl-2, Bcl-xL and Mcl-1 protein were comparable to parental cells. Transfection of RRCL with Bax or Bak sensitized them to apoptotic cell death. Currently, we are attempting to validate previous studies that have shown that down-regulation of Bax and/or Bak correlates with a poor prognosis in NHL. Additionally, we are exploring the mechanism(s) by which Bax and Bak are down-regulated in RRCL and primary patient samples.

Effect of obinutuzumab (GA101), a type II glycoengineered monoclonal antibody targeting CD20, against rituximab resistant and sensitive cell lines in B-cell non-Hodgkin lymphoma.

2012 ◽  
Vol 30 (15_suppl) ◽  
pp. e21150-e21150
Author(s):  
Aradhana Tiwari ◽  
Janet Ayello ◽  
Carmella Van de ven ◽  
Mitchell S. Cairo
Keyword(s):  
Cell Death ◽  
B Cell ◽  
Cell Lines ◽  
Raji Cell ◽  
Resistant Cell ◽  
Chemotherapeutic Agents ◽  
Cancer Center ◽  
Type Ii ◽  
Sensitive Cell ◽  
Minimal Cell

e21150 Background: : Relapse or insufficient response or resistance to Rituximab (RTX) has evolved as a challenge in therapy of B-cell NHL. RTX in combination with FAB chemotherapy is a safe, well tolerated and associated with > 90% EFS in children with advanced mature B-Cell NHL (Cairo M.S. et al, ASCO 2010). Obinutuzumab (GA101), a novel type II glyco-engineered CD20 antibody of the IgG1 isotype, demonstrates superior cell death induction and its glycoengineered Fc region has shown to cause significantly enhanced ADCC (Mössner et al, Bld 2010; Niederfellner G. et al, Bld 2011). We evaluated the efficacy of GA101 against Raji (Burkitt Lymphoma), a RTX sensitive cell line (RSCL) and RTX resistant cell lines(RRCL), Raji-2R and Raji-4RH, respectively (generously supplied by M. Barth, MD, Roswell Park Cancer Center, Buffalo, NY. Barth M. et al, ASH 2010). Methods: All cell lines were cultured in RPMI with 10% FBS and incubated with escalating doses of GA101 (1-1000 µg/ml) for 24 hrs (n=10), 48 and 72 hrs (n=6). Cell death was evaluated by staining with AnnexinV/7AAD and flow-cytometry. B-Cell Lymphoblastic Lymphoma (BLL) U-698-M cells (CD20+) were used as the positive and Loucy cells (CD20-) (T-ALL) were used as the negative controls. Results: At 48 hrs 100 µg/ml of GA101, Raji and U-698-M demonstrated highest cell death of 33.62±5.7% and 37.8± 3.9%, respectively; while Raji-2R and Raji-4RH cell death was 22.8±1.8% and 10.31±0.81% (p<0.02) and (p<0.001) respectively. At 1000 µg/ml of GA101 at 24 hrs, Raji demonstrated increased cell death 40.27±9.1% compared with Raji2R 14.1±0.07 and Raji4RH 20.3± 3.2 (p<0.001) and (p<0.001) respectively. Conclusions: GA101 represents a promising candidate for treating RTX resistant B-Cell Lymphomas and related CD20+B-Cell malignancies. Further studies should aim to identify novel approaches such as combination with activated NK Cells or chemotherapeutic agents that may enhance or synergize with the efficacy of GA101. Further investigations aim to elucidate the mechanisms responsible for minimal cell death induction on the U698M and Raji cell lines.

Targeting the extrinsic apoptotic pathway in endometrial carcinoma cell lines and tumor cell explants

2009 ◽  
Vol 27 (15_suppl) ◽  
pp. e16555-e16555
Author(s):  
X. Matias-guiu ◽  
X. Dolcet ◽  
D. Llobet ◽  
A. Poveda ◽  
J. Pallares ◽  
...  
Keyword(s):  
Cell Death ◽  
Tumor Cell ◽  
Endometrial Carcinoma ◽  
Cell Lines ◽  
Apoptotic Cell ◽  
Apoptosis Resistance ◽  
Down Regulation ◽  
Apoptotic Pathway ◽  
Extrinsic Apoptotic Pathway ◽  
Induced Apoptosis

e16555 Background: Endometrial carcinoma (EC) frequently shows deregulation of the extrinsic apoptotic pathway. One of the critical regulators of apoptosis resistance in EC is FLIP, under the control of NFkB and a cellular complex composed of CK2, KSR1, and BRAF. Methods: Four different EC cell lines, which are known to exhibit resistance to TRAIL/FAS-induced apoptosis (Ishikawa, KLE, HEC1A, and RL-95) were exposed to various pharmacologic substances that target proteins involved in the regulation of the extrinsic apoptotic pathway and receptor tyrosine kinases including bortezomib, sorafenib, sunitinib, DRB, apigenin, MG-132, epoxomicin, and ALLN. Moreover, EC cell lines were subjected to down-regulation of several of these genes (FLIP, CK2, KSR1, and BRAF) by shRNA. Cell viability and apoptotic morphology was determined. Results were validated in tumor cell explants. Results: Bortezomib induced cell death on EC cells and primary explants to a 70% extent. However, 100% of treated explants and cell lines activated NF-kB instead of blocking its transcriptional potential. Combination of sunitinib plus bortezomib induced 75% fold reduction in NFkB activity and induced a 5% of synergistic increse of apoptotic cell death in Ishikawa cells. Treatment of the four cell lines with TRAIL failed to induce cell death. However, FLIP knock-down sensitized the cells to TRAIL-induced apoptosis (80%). Moreover, down-regulation of CK2, KSR1, and BRAF by pharmacological inhibition, or shRNA, reduced FLIP cellular levels, and induced TRAIL-dependent apoptosis in 70%-100% of EC cell lines tested. Sorafenib induced a dose-dependent cell death in all four cell lines, to a 70%-100% extent at 48 hours. Conclusions: In vitro pharmacologic targeting of the apoptotic pathway effectively induces cell death in EC cell lines. These findings justify clinical trials with these agents in EC. [Table: see text]

Activation of the intrinsic-apoptotic pathway in LNCaP prostate cancer cells by genistein- topotecan combination treatments

2013 ◽  
Vol 3 (3) ◽  
pp. 66 ◽  
Author(s):  
Vanessa Hörmann ◽  
Sivanesan Dhandayuthapani ◽  
James Kumi-Diaka ◽  
Appu Rathinavelu
Keyword(s):  
Prostate Cancer ◽  
Cell Death ◽  
Cancer Cells ◽  
Apoptotic Cell ◽  
Treatment Options ◽  
Attractive Alternative ◽  
Intrinsic Apoptotic Pathway ◽  
Prostate Cancer Cells ◽  
Apoptotic Pathway ◽  
Combination Treatments

Background: Prostate cancer is the second most common cancer in American men. The development of alternative preventative and/or treatment options utilizing a combination of phytochemicals and chemotherapeutic drugs could be an attractive alternative compared to conventional carcinoma treatments. Genistein isoflavone is the primary dietary phytochemical found in soy and has demonstrated anti-tumor activities in LNCaP prostate cancer cells. Topotecan Hydrochloride (Hycamtin) is an FDA-approved chemotherapy for secondary treatment of lung, ovarian and cervical cancers. The purpose of this study was to detail the potential activation of the intrinsic apoptotic pathway in LNCaP prostate cancer cells through genistein-topotecan combination treatments. Methods: LNCaP cells were cultured in complete RPMI medium in a monolayer (70-80% confluency) at 37ºC and 5% CO2. Treatment consisted of single and combination groups of genistein and topotecan for 24 hours. The treated cells were assayed for i) growth inhibition through trypan blue exclusion assay and microphotography, ii) classification of cellular death through acridine/ ethidium bromide fluorescent staining, and iii) activation of the intrinsic apoptotic pathway through Jc-1: mitochondrial membrane potential assay, cytochrome c release and Bcl-2 protein expression.Results: The overall data indicated that genistein-topotecan combination was significantly more efficacious in reducing the prostate carcinoma’s viability compared to the single treatment options. In all treatment groups, cell death occurred primarily through the activation of the intrinsic apoptotic pathway.Conclusion: The combination of topotecan and genistein has the potential to lead to treatment options with equal therapeutic efficiency as traditional chemo- and radiation therapies, but lower cell cytotoxicity and fewer side effects in patients. Key words: topotecan; genistein; intrinsic apoptotic cell death

scholarly journals BCR-ABL maintains resistance of chronic myelogenous leukemia cells to apoptotic cell death [published erratum appears in Blood 1994 Jun 15;83(12):3835]

Blood ◽  
1994 ◽  
Vol 83 (5) ◽  
pp. 1179-1187 ◽  
Author(s):  
A McGahon ◽  
R Bissonnette ◽  
M Schmitt ◽  
KM Cotter ◽  
DR Green ◽  
...  
Keyword(s):  
Cell Death ◽  
Chronic Myelogenous Leukemia ◽  
Apoptotic Cell ◽  
Chimeric Protein ◽  
Chemotherapeutic Agents ◽  
Myelogenous Leukemia ◽  
Temperature Sensitive ◽  
Permissive Temperature ◽  
Expression Of Genes ◽  
Induction Of Apoptosis

Abstract Apoptosis is the major form of cell death associated with the action of chemotherapeutic agents on tumor cells, and therefore the expression of genes that interfere with apoptosis can have important consequences for the efficacy of therapeutic approaches. Here we show that K562, a chronic myelogenous leukemia (CML) cell line expressing the BCR-ABL fusion protein, are resistant to the induction of apoptosis by a number of agents and conditions. Antisense oligodeoxynucleotides corresponding to the translation start of bcr downregulate bcr-abl protein in these cells and render them susceptible to induction of apoptosis by chemotherapeutic agents or serum deprivation. Expression of a temperature sensitive v-Abl protein reverses the effects of the antisense oligonucleotides, such that the cells remain resistant to apoptosis at the permissive temperature. These data indicate that bcr- abl acts as an anti-apoptosis gene in CML cells and suggests that the effect is dependent on the abl kinase activity in this chimeric protein. Inhibition of bcr-abl to render CML cells susceptible to apoptosis can be combined with therapeutic drugs and/or treatment capable of inducing apoptosis to provide an effective strategy for elimination of these cells.

The anti-apoptotic response of the Gq/11-coupled muscarinic receptor family

2003 ◽  
Vol 31 (6) ◽  
pp. 1182-1185 ◽  
Author(s):  
A.B. Tobin ◽  
D.C. Budd
Keyword(s):  
Cell Death ◽  
Muscarinic Receptor ◽  
Apoptotic Cell ◽  
Mitogen Activated Protein Kinase ◽  
Receptor Subtype ◽  
Receptor Subtypes ◽  
Muscarinic Receptor Subtypes ◽  
Structural Element ◽  
Apoptotic Pathway ◽  
Receptor Family

It is now clear that G-protein-coupled receptors can regulate programmed cell death (apoptosis) through a variety of mechanisms that are dependent on cell type and receptor subtype. Here we present evidence that the Gq/11-coupled subtypes of the muscarinic receptor family (namely M1, M3 and M5-muscarinic receptor subtypes) are able to protect against apoptotic cell death. In particular we demonstrate that the C-terminal tail of the M3-muscarinic receptor is an essential structural element for signalling to the anti-apoptotic pathway. Removal of the distal portion of the C-terminal tail results in a receptor that is coupled normally to the Gq/11/phospholipase C pathway and the mitogen-activated protein kinase pathway, but is unable to couple to the anti-apoptotic pathway. Furthermore, a poly-basic region conserved within the C-terminal tail of the Gq/11-coupled muscarinic receptor subtypes appears to be the structural determinant of coupling to the anti-apoptotic pathway.

Mevalonate pathway inhibitors in the treatment of B-cell chronic lymphocytic leukemia.

2012 ◽  
Vol 30 (15_suppl) ◽  
pp. 6561-6561
Author(s):  
Ravi Kiran Bobba ◽  
Indira Benakanakere ◽  
Smitha Bearelly ◽  
Monica Arya ◽  
Richard Sleigtholm ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Cell Death ◽  
Chronic Lymphocytic Leukemia ◽  
Cell Viability ◽  
B Cell ◽  
Combination Treatment ◽  
Mevalonate Pathway ◽  
Chemotherapeutic Agents ◽  
Lymphocytic Leukemia ◽  
Cell Chronic Lymphocytic Leukemia

6561 Background: B-cell chronic lymphocytic leukemia (CLL) cells are arrested in G0/G1 phase of the cell cycle and are resistant to programmed cell death, hypothesized to contribute to the resistance of CLL cells to standard chemotherapy with curative intent. Methods: Mec-2 cells and Wac-3 cells are CLL cells that have been shown to be resistant to fludarabine and rituximab. We tested a novel enzyme inhibitor’s ability to render CLL cells sensitive to fludarabine and rituximab. Results: BIBB515, a lanosterol synthase inhibitor, at a concentration of 10μM, was able to reduce the cell viability from 82% in controls to 65% after 72 hours. Fludarabine 10μM alone did not reduce the cell viability, 82 % in controls compared to 80%. BIBB515+ fludarabine treatment for 72 hours, at the dose of 10μM each decreased the cell viability to 37%. Cell proliferation by MTT assay was 0.66±0.010 in control compared to 0.37±0.01 in BIBB515+fludarbine and 0.21±0.01 in BIBB515+ fludarabine+ rituximab. There is a 68% down-regulation of cell proliferation using this treatment. There was a two fold induction of CD 20 with combination treatment, and BIBB515 treatment. The mechanism of cell death in the combination treatment of BIBB515 and fludarabine may be due to the up regulation of cell surface marker CD-20. WAC-3 is another CLL cell line that is sensitive to fludarabine, and resistant to rituximab. BIBB515 sensitizes WAC-3 cells to CD 20 antibody rituximab. There is a 68.7% decrease in cell proliferation with combination treatment of BIBB515 and rituximab. Proliferation of Mec-2 cells were inhibited by 60µM and 30µM terbinafine. Ro-48-8071, showed dose-dependent activity, alone or in combination to fludarabine was seen to induce cell death in Mec-2 cells. Fludarabine alone did not have any effect on these cells. Conclusions: Inhibitors of the mevalonate pathway make resistant CLL cells sensitive to current chemotherapeutic agents. Exploiting this mechanism could alter the current treatment regimens, leading to control of the disease in advanced stages by either inducing the leukemic cells to be static or to regress. This strategy may also limit the toxicities involved with chemotherapy.

scholarly journals TAK1 is required for the survival of hematopoietic cells and hepatocytes in mice

2008 ◽  
Vol 205 (7) ◽  
pp. 1611-1619 ◽  
Author(s):  
Minghui Tang ◽  
Xudong Wei ◽  
Yinshi Guo ◽  
Peter Breslin ◽  
Shubin Zhang ◽  
...  
Keyword(s):  
Cell Death ◽  
B Cell ◽  
Cell Activation ◽  
Transforming Growth Factor ◽  
Apoptotic Cell ◽  
Hematopoietic Cells ◽  
Transforming Growth Factor Β ◽  
Nuclear Factor Κb ◽  
Regulation Of Expression ◽  
Hematopoietic Stem

Transforming growth factor β–activated kinase 1 (TAK1), a member of the MAPKKK family, is a key mediator of proinflammatory and stress signals. Activation of TAK1 by proinflammatory cytokines and T and B cell receptors induces the nuclear localization of nuclear factor κB (NF-κB) and the activation of c-Jun N-terminal kinase (JNK)/AP1 and P38, which play important roles in mediating inflammation, immune responses, T and B cell activation, and epithelial cell survival. Here, we report that TAK1 is critical for the survival of both hematopoietic cells and hepatocytes. Deletion of TAK1 results in bone marrow (BM) and liver failure in mice due to the massive apoptotic death of hematopoietic cells and hepatocytes. Hematopoietic stem cells and progenitors were among those hematopoietic cells affected by TAK1 deletion–induced cell death. This apoptotic cell death is autonomous, as demonstrated by reciprocal BM transplantation. Deletion of TAK1 resulted in the inactivation of both JNK and NF-κB signaling, as well as the down-regulation of expression of prosurvival genes.

Sign in / Sign up

Export Citation Format

Share Document