Combined Epigenetic and Immunotherapy For Newly Diagnosed Mantle Cell Lymphoma: Correlative Studies Suggest The Importance Of Enhanced ADCC, Mechanisms of Resistance and Cyclin D1 Nuclear Localization Genotype

Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 3063-3063
Author(s):  
Kamal Sharma ◽  
Violetta V. Leshchenko ◽  
Zainul Hasanali ◽  
August Stuart ◽  
Sara Shimko ◽  
...  
Keyword(s):  
Complete Remission ◽  
Cyclin D1 ◽  
Nuclear Localization ◽  
Cell Lymphoma ◽  
Newly Diagnosed ◽  
Mantle Cell ◽  
Correlative Studies

Abstract Previously, we reported that epigenetic therapy with cladribine, SAHA, and rituximab (SCR) for newly diagnosed mantle cell lymphoma was remarkably effective, with 100% overall response rate, 85-90% CR rate, and durable responses( Hasanali, AACR,2013 LBA140). Over 40 patients now have been enrolled with all patients completing therapy. Final response and CR rates will be reported at the meeting. This abstract will focus on the correlative studies performed as part of this trial. Cladribine, a purine analog with reported epigenetic activity was shown here by HELP assays to inhibit DNA methylation in vivo in 6 patients with leukemic MCL. Similar activity was also observed in two MCL and two CLL patients treated with cladribine without vorinostat off trial, suggesting cladribine is a DNA hypomethylating agent. Due to cladribine's ability to inhibit the enzyme SAH hydrolase and thus inhibit the donation of methyl groups by S-adenosyl methionine (SAM), we assayed the ability of cladibine to inhibit histone methylation in vitro by Western blot analysis and in vitro assays of histone methyltransferase (HMT) activity on H3lys9 and H3lys27. Both assays demonstrated inhibition of methylated histones (Western) and HMT activity using MCL cell cells and nuclear extract at concentrations of cladribine in the 10-20 um range, higher than the in vivo concentration of 10-20 nm. These observations could be due to the lack of sensitivity of these assays, and more sensitive assays are in development. Studies to help elucidate the mechanism of action of synergy of epigenetic drugs with the monoclonal antibody rituximab were performed. Using cells from patients with leukemic MCL treated with SCR, we assayed for characteristic changes of apoptosis using Western blotting and TUNEL assays. None were detected. We were unable to observe complement mediated cytoxicity in vitro using human serum and rituximab with added cladribine or vorinostat. With ADCC being the primary mechanism of presumed combined epigenetic and rituximab synergy, we investigated ADCC further. CD137 transcriptional upregulation was seen in several but not all treated patients, and some patients showed up regulation of perforin and granzyme mRNA by QRTPCR. An NK cell line, NKL, showed transcriptional upregulation of CD137 after treatment with cladribine and vorinostat. A polymorphism at an intron-exon junction effects the nuclear localization of cyclin D1 by removing a nuclear export signal. Although there is published evidence supporting the role of nuclear cyclin D1 in increased oncogenesis, the role of this polymorphism in MCL remains controversial. Samples from peripheral blood of patients on trial were genotyped at the cyclin D1 locus as AA, AG, or GG, with the A allele being the loss of function allele. The presence of the A allele strongly correlated with the blastic phenotype and the lack of complete remission after SCR therapy, with both being statistically significant (table 1). Immunofluorescent studies with cyclin D1 antibodies showed nuclear and cytoplasmic localization as predicted in patients with the AA and GG genotypes (Fig 1). The heterozygotes are under investigation and will be reported. The mechanism of resistance to SCR was studied in a patient with blastic, leukemic MCL. A 63 male achieved complete remission after two cycles of SCR. Subsequently, he developed neurologic symptoms and was found to have CNS disease. At autopsy, CD20+ disease was found in his CNS and CD20- disease was found systemically. A cell line was established from his peripheral blood that showed significantly reduced levels of CD20 mRNA. Treatment of these cells with a variety of epigenetic drugs was unable to upregulate CD20 mRNA. These cells have been in continuous culture for over 1 year and continue to show diminished levels of CD20 mRNA and protein. Epigenetic changes at the promoter are being studied by chromatin immunoprecipation (ChiP) assays. Disclosures: No relevant conflicts of interest to declare.

Antitumoral Activity of Lenalidomide in In Vitro and In Vivo Models of Mantle Cell Lymphoma Involves the Destabilization of Cyclin D1/p27KIP1 Complexes

2013 ◽  
Vol 20 (2) ◽  
pp. 393-403 ◽  
Author(s):  
Alexandra Moros ◽  
Sophie Bustany ◽  
Julie Cahu ◽  
Ifigènia Saborit-Villarroya ◽  
Antonio Martínez ◽  
...  
Keyword(s):  
Cyclin D1 ◽  
Mantle Cell Lymphoma ◽  
Cell Lymphoma ◽  
Antitumoral Activity ◽  
In Vivo Models ◽  
Mantle Cell

Targeting the Cyclin D - CDK4/6 - Rb Axis in Mantle Cell Lymphoma with the Novel Translation Inhibitor Silvestrol,

Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 3498-3498
Author(s):  
Lapo Alinari ◽  
Ryan B. Edwards ◽  
Courtney J. Prince ◽  
William H. Towns ◽  
Rajeswaran Mani ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Cyclin D1 ◽  
Tumor Cells ◽  
Cell Lymphoma ◽  
S Phase ◽  
Cyclin D ◽  
Mantle Cell ◽  
Phase Entry

Abstract Abstract 3498 During cell cycle progression, D class cyclins activate cyclin dependent kinases (CDK) 4 and 6 to phosphorylate and inactivate Rb, allowing E2F-1 mediated transcription of additional cell cycle genes including cyclin E to drive S phase entry. This critical pathway is nearly universally dysregulated in cancer, providing tumor cells a strong growth advantage and escape from normal mitotic control. Substantial research is being directed toward targeting this pathway in many cancer types, with some preliminary successes being achieved with pharmacologic inhibitors of CDK4/6. However the development of alternative strategies to block this pathway could potentially provide broad therapeutic benefit. A prime example of a tumor with a disrupted cyclin D axis is Mantle Cell Lymphoma (MCL), in which the t(11;14) translocation places CCND1, the gene for cyclin D1, under the control of an immunoglobulin promoter. This results in sustained cyclin D1 expression in tumor cells and concomitant Rb inactivation, S phase entry and cell division. MCL is a relatively uncommon subset of Non-Hodgkin Lymphoma, but accounts for a disproportionate number of deaths. Treatments are limited and relapse is nearly universal; thus, new treatment strategies are essential for this disease. Silvestrol is a structurally unique, plant-derived cyclopenta[b]benzofuran with potent in vitro and in vivo anti-tumor activity in several model systems including B-cell acute lymphoblastic leukemia (ALL) and chronic lymphocytic leukemia (CLL). Silvestrol inhibits the initiation step of translation by preventing assembly of eIF4A and capped mRNA into the eIF4F complex, leading to selective loss of short half-life proteins such as Mcl-1 and cyclin D1. We therefore hypothesized that silvestrol, through the depletion of cyclin D1, would demonstrate efficacy in MCL. Silvestrol showed low nanomolar IC50 values in the JeKo-1 (13 nM), Mino (17 nM) and SP-53 (43 nM) MCL cell lines at 48 hr (MTS assay; cell death confirmed by propidium iodide flow cytometry). This potency was similar in primary MCL tumor cells. Longer exposure times substantially improved the cytotoxicity of silvestrol assessed at 48 hr (approximately 50% effect achieved with a 16 hr exposure vs. 80% effect with a 24 hr exposure), suggesting that the cellular impacts of this agent increase with exposure time. Cyclins D1 and D3 were dramatically reduced in MCL cell lines with just 10 nM silvestrol at 16 hr (cyclin D2 was undetectable in these cells), with subsequent loss of Rb phosphorylation as well as cyclin E mRNA and protein, culminating in G1 cell cycle arrest. Similar to what we previously showed in CLL and ALL cells, silvestrol treatment under these conditions also caused loss of Mcl-1 protein with concurrent mitochondrial depolarization, although the exact mechanism of silvestrol-mediated cytotoxicity in these cells is still under investigation. In an aggressive xenograft mouse model of MCL, silvestrol produced a highly significant improvement in survival [median survival of vehicle vs. silvestrol treated mice (1.5 mg/kg every 48 hr) = 27 vs. 38 days; P<0.0001] without detectable toxicity. Together, these data demonstrate that the translation inhibitor silvestrol has promising in vitro and in vivo activity in MCL preclinical models. Furthermore, as the cyclin D/CDK/Rb axis is disrupted in most tumor types, this strategy may be broadly effective in other cancers as well. Disclosures: No relevant conflicts of interest to declare.

Novel Treatment for Therapy-Resistant Mantle Cell Lymphoma Targeting NF-κB and mTOR Signaling Pathways in Vitro and in Vivo

Blood ◽  
2012 ◽  
Vol 120 (21) ◽  
pp. 63-63
Author(s):  
Nagendra K Chaturvedi ◽  
Rajkumar Rajule ◽  
Shukla Ashima ◽  
Prakash Radhakrishnan ◽  
Amarnath Natarajan ◽  
...  
Keyword(s):  
Cyclin D1 ◽  
Mantle Cell Lymphoma ◽  
Therapeutic Efficacy ◽  
Cellular Proliferation ◽  
Conflicts Of Interest ◽  
Cell Lymphoma ◽  
Thymidine Uptake ◽  
Mantle Cell

Abstract Abstract 63 Background: Mantle cell lymphoma (MCL) is one of the most aggressive B-cell non-Hodgkin lymphomas (NHL) with a median survival of less than five years. Currently, there is no curative therapy available for refractory MCL because of relapse from therapy-resistant tumor cells. It has been well documented that the NF-κB and mTOR pathways are constitutively active in MCL leading to increased survival, proliferation and decreased apoptosis. Therefore, in an effort to improve therapy for refractory MCL, we investigated the antilymphoma activity in vitro and in vivo and associated molecular mechanism of action of 13–197, a quinoxaline analog that specifically perturbs IκB kinase (IKK) β, an upstream kinase of the NF-κB and mTOR pathways. Methods: Established therapy-resistant from Granta 519 (Ahrens and Chaturvedi et al, Leukemia and Lymphoma doi:10.3109/10428194.2012.691481), other MCL cell lines Mino and Rec-1 and primary MCL cells from patients were used in this study. These MCL cells were treated in vitro with varying concentrations of 13–197 for the different time points. Cellular proliferation/viability, cytomorphology, frequency of cells undergoing apoptosis in treated and control cells were evaluated using 3[H]-thymidine uptake, MTT assay, cytomorphology and Annexin-V staining methods respectively. The status of key molecules in the NF-κB and mTOR pathways were examined in therapy-resistant and parental MCL cells following treatment with 13–197 using western blot analyses. The results of these analyses were compared to untreated control cells as appropriate and statistical significance of the results were determined using student‘t’ test. In addition, in vivo therapeutic efficacy of 13–197 was investigated using NOD-SCID mouse bearing therapy-resistant MCL. Results: Our results showed that 13–197 significantly decreased the proliferation and induced a ∼four-fold (P<0.005) increase in apoptosis in parental and therapy-resistant MCL cells compared to control cells. At the molecular level, we observed down-regulation of IκBα phosphorylation and inhibition of NF-κB nuclear translocation by the 13–197 in MCL cells. In addition, NF-κB regulated genes such as cyclin D1, Bcl-XL and Mcl-1 were down-regulated in 13–197-treated cells. 13–197 also inhibited the phosphorylation of S6K and 4E-BP1, the downstream molecules of mTOR pathway that are also activated in refractory MCL. Further, to investigate the therapeutic efficacy of 13–197 against therapy-resistant MCL in vivo, we treated NOD-SCID mice bearing therapy-resistant MCL with 13–197; there was significantly reduced tumor burden in the kidney (p>0.05), liver (p>0.01), and lungs (p>0.03) of 13–197 treated mice compared to vehicle treated mice. Indeed, 13–197 treatment significantly increased the survival (p>0.001) of MCL transplanted mice. Taken together, our results suggest that 13–197 targets IKKβ which leads to both the transcriptional (NF-κB) and translational (mTOR) downregulation of gene products (cyclin D1, Bcl-XL and Mcl-1) misregulated in therapy-resistant MCL. Summary/Conclusions: Overall, results suggest that 13–197 perturbs the NF-κB and mTOR pathways leading significant antilymphoma effects in vitro and in vivo thus demonstrates its potentials to be a therapeutic agent for refractory MCL. (This work was supported by the Lymphoma Research Foundation New York, NY) Disclosures: No relevant conflicts of interest to declare.

scholarly journals FTY720 Shows Promising In vitro and In vivo Preclinical Activity by Downmodulating Cyclin D1 and Phospho-Akt in Mantle Cell Lymphoma

2010 ◽  
Vol 16 (12) ◽  
pp. 3182-3192 ◽  
Author(s):  
Qing Liu ◽  
Lapo Alinari ◽  
Ching-Shih Chen ◽  
Fengting Yan ◽  
James T. Dalton ◽  
...  
Keyword(s):  
Cyclin D1 ◽  
Mantle Cell Lymphoma ◽  
Cell Lymphoma ◽  
Mantle Cell

A Novel Pro-Survival Function of Cyclin-D1 Underlies Its Oncogenic Role and Potential as a Therapeutic Target In Mantle Cell Lymphoma

Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 769-769
Author(s):  
Elena Beltran ◽  
Vicente Fresquet ◽  
Javier Martinez-Useros ◽  
Jose A. Richter-Larrea ◽  
Ainara Sagardoy ◽  
...  
Keyword(s):  
Cyclin D1 ◽  
Mantle Cell Lymphoma ◽  
Cell Lymphoma ◽  
Survival Function ◽  
Chromosomal Translocation ◽  
Molecular Features ◽  
Oncogenic Pathways ◽  
Mantle Cell

Abstract Abstract 769 Despite the many and diverse therapeutic approaches used to treat patients with mantle cell lymphoma (MCL), it remains an incurable disease. Recently, attention has turned into novel therapies targeting MCL-specific oncogenic pathways important for the growth and maintenance of the transformed phenotype. The chromosomal translocation t(11;14)(q13;q32) leading to cyclin-D1 over-expression is the hallmark of MCL. Constitute cyclin-D1 activation in B-lymphocytes maintains retinoblastoma protein in a phosphorylated state and promotes cell cycling, thus initiating the tumorigenesis process. Cyclin-D1 has been postulated as a putative target for therapeutic intervention, however its evaluation has been hampered by the incomplete understanding of the mechanism underlying this cyclin oncogenic function and by the lack of valid MCL models. To investigate these issues, we developed a combined cellular-genomics screening whereby responses to known cytotoxic compounds targeting cancer-related molecular pathways were correlated with genomic, gene expression and proteomic profiles of human MCL cells. Results showed that cyclin-D1 silencing had minimal antitumoral effects but significantly increased the therapeutic efficacy of several compounds, especially the BH3 mimetics that inhibited anti-apoptotic protein BCL-2. To further evaluate this finding we generated a MCL mouse model by transducing a tetracycline-regulatable cyclin-D1-expressing vector in murine pro-B cells, which allowed modulating cyclin-D1 expression levels. These mice generated lymphomas recapitulating most of the cellular, histopathological and molecular features of human MCL. Similar to the previous in vitro findings, cyclin-D1 inhibition in this model did not induce lymphoma regression, but sensitized cells to apoptosis. Analysis of the mechanisms underlying this therapeutic synergy identified a novel role for cyclin-D1 as a pro-survival molecule. Specifically, cyclin-D1 sequestrated the pro-apoptotic effector protein BAX in MCL cells, thereby favoring BCL2 anti-apoptotic function. Accordingly, therapeutic cyclin-D1 inactivation released BAX, thus sensitizing cells to apoptosis and inducing lymphoma regression. Interestingly, pharmacological blockade in vivo of cyclin-D1 with Roscovitine synergistically cooperated with the BH3 mimetic ABT-737 to effectively inhibit MCL tumor growth. In summary, our study reveals a novel role for cyclin-D1 in deregulating apoptosis in MCL cells and highlights the potential benefit of cyclin-D1 targeting, thus providing the rationale for the clinical evaluation of drugs targeting cell proliferation and survival pathways in MCL. Disclosures: Siebert: Abbott: Honoraria.

Newer-Generation HSP90 Inhibitors Have Potent Activity Against Human Mantle Cell Lymphoma in Vitro and in Vivo

Blood ◽  
2012 ◽  
Vol 120 (21) ◽  
pp. 1651-1651
Author(s):  
Oliver Weigert ◽  
Diederik van Bodegom ◽  
Liat Bird ◽  
Amy Saur ◽  
Trevor Tivey ◽  
...  
Keyword(s):  
Cell Death ◽  
Cyclin D1 ◽  
Mantle Cell Lymphoma ◽  
Cell Lines ◽  
Cell Lymphoma ◽  
Cell Killing ◽  
Hsp90 Inhibitors ◽  
Mantle Cell

Abstract Abstract 1651 Mantle cell lymphoma (MCL) is associated with particularly poor outcome, with long-term survival achieved in less than 40% of patients. In addition to the characteristic t(11;14) that results in overexpression of cyclin D1, a variety of other molecular pathways are dysregulated in MCL. Cyclin D1 is a known client of heat shock protein 90 (HSP90), suggesting that inhibitors of HSP90 may destabilize cyclin D1 and have activity in this disease. Yet, first-generation HSP90 inhibitors such as 17-AAG generally lack potency in MCL cell lines. We assessed the pre-clinical activity of second- (NVP-AUY922, PU-H71) and third-generation (NVP-HSP990) HSP90 inhibitors, which have greater potency and superior in vivo pharmacokinetics, in the MCL cell lines Granta519, JeKo1, MAVER1, Rec1, and Z-138. To define the genetics of these lines, we utilized an exon-capture followed by next-generation sequencing approach to identify single nucleotide variants and insertions/deletions across the entire coding sequence of 197 genes known to be recurrently altered in lymphoid malignancies. Sequencing to a median depth of coverage∼400 recovered alterations previously described in MCL (e.g. in ATM, RB1, TP53, NOTCH1) as well as variants in genes that have not previously been associated with MCL (e.g. in MLL2, KDM6A, FLT3, IKZF3, JAK3, RFXAP). Dose response curves of these cell lines treated with structurally diverse HSP90 inhibitors showed 10–100-fold greater potency for NVP-AUY922 (IC50, 3–11 nM), NVP-HSP990 (IC50, 5–24 nM) and PU-H71 (IC50, 40–287 nM), compared with 17-AAG (IC50, 29–1503 nM). In vitro exposure of all lines to 50 nM AUY922 resulted in G0/G1 cell cycle arrest within 6–8 hrs followed by apoptosis within 24–72 hours. Immunoblotting after exposure to AUY922 demonstrated rapid reductions in HSP90 client proteins, including cyclin D1, CDK4 and AKT, in all lines as well as accumulation of HSP70 in all lines except REC1, which harbors an HSP70 locus deletion. Cell killing by AUY922 (based on Annexin V/PI flow cytometry, caspase 3/7 activation and PARP cleavage) varied between cell lines, with Granta519 being the most sensitive (>50% cell death after 24 hr exposure) and Rec1 being the least sensitive (<15% cell death under the same conditions). Co-culture of Granta519, JeKo1, and Z-138 cells with bone marrow stroma had no effect on killing by AUY922, suggesting that HSP90 inhibition may overcome cell non-autonomous pathways that support resistance to other antineoplastic agents. To build on these findings in vivo, we xenografted luciferized MAVER1 (harbors TP53 D281E and JAK3 V722I mutations) and Z-138 (TP53 and JAK3 wild-type) cells into SCID beige mice (10 million cells per mouse). Upon evidence of measurable engraftment, mice (10 per arm) were randomized to receive either AUY922 (50 mg/kg by tail vein injection thrice weekly) or vehicle. Tumors were analyzed from sentinel mice that were sacrificed after 5 days of treatment. Tumors from mice receiving AUY922 had complete loss of cyclin D1 and Ki67 staining by immunohistochemistry. 18F-FLT PET scanning performed on mice xenografted with Z-138 cells demonstrated ∼75% reduction in activity after 5 days of AUY922 treatment. Consistent with these findings, tumor growth was significantly slowed among AUY922-treated animals for both lines, which translated into a survival advantage (p<0.01 for MAVER1 and p=0.03 for Z-138). Finally, in an effort to enhance cell killing, we combined AUY922 with compounds in clinical use for MCL. In JeKo1, MAVER1, Rec1 and Z-138 cells, combinations with AUY922 were either antagonistic (with cytarabine or doxorubicin) or lacked synergistic effects (with bortezomib). AUY922 also failed to block the accumulation of MCL1 induced by exposure to bortezomib. Thus, appropriate drug combination partners for AUY922 in MCL remain to be determined. In conclusion, newer-generation HSP90 inhibitors such as AUY922 have significant single-agent activity across a genetically diverse spectrum of MCLs, can target cyclin D1, CDK4, AKT and other drivers of malignant phenotype, and warrant evaluation in clinical trials. Disclosures: Weinstock: Novartis: Consultancy, Research Funding.

scholarly journals Role of the microenvironment in mantle cell lymphoma: IL-6 is an important survival factor for the tumor cells

Blood ◽  
2012 ◽  
Vol 120 (18) ◽  
pp. 3783-3792 ◽  
Author(s):  
Liang Zhang ◽  
Jing Yang ◽  
Jianfei Qian ◽  
Haiyan Li ◽  
Jorge E. Romaguera ◽  
...  
Keyword(s):  
Mantle Cell Lymphoma ◽  
Cell Lymphoma ◽  
Drug Induced ◽  
Growth And Survival ◽  
Chemotherapy Drugs ◽  
Non Hodgkin Lymphoma ◽  
Mantle Cell

Abstract Mantle cell lymphoma (MCL) is an aggressive B-cell non-Hodgkin lymphoma frequently involved in the lymph nodes, bone marrow, spleen, and gastrointestinal tract. We examined the role of IL-6 in MCL. Human MCL cells expressed the membrane gp130 and soluble gp80, and some of them also secreted IL-6. Neutralizing autocrine IL-6 and/or blocking IL-6 receptors in IL-6+/gp80+ MCL cells inhibited cell growth, enhanced the rate of spontaneous apoptosis, and increased sensitivity to chemotherapy drugs. For IL-6− or gp80low MCL cells, paracrine or exogenous IL-6 or gp80 protected the cells from stress-induced death. Knockdown of gp80 in gp80high MCL cells rendered the cells more sensitive to chemotherapy drugs, even in the presence of exogenous IL-6. In contrast, overexpression of gp80 in gp80low/IL-6+ MCL cells protected the cells from chemotherapy drug-induced apoptosis in vitro and compromised the therapeutic effect of chemotherapy in vivo. IL-6 activated the Jak2/STAT3 and PI3K/Akt pathways in MCL, and the inhibition of these pathways completely or partially abrogated IL-6–mediated protection of MCL cells. Hence, our study identifies IL-6 as a key cytokine for MCL growth and survival and suggests that targeting the IL-6 pathway may be a novel way to improve the efficacy of chemotherapy in MCL patients.

scholarly journals The Synthetic Compound Norcantharidin Induced Apoptosis in Mantle Cell Lymphoma In Vivo and In Vitro through the PI3K-Akt-NF-κB Signaling Pathway

2013 ◽  
Vol 2013 ◽  
pp. 1-11 ◽  
Author(s):  
Hongyan Lv ◽  
Yan Li ◽  
Hengfei Du ◽  
Jie Fang ◽  
Xiaoning Song ◽  
...  
Keyword(s):  
Cyclin D1 ◽  
Mantle Cell Lymphoma ◽  
Signaling Pathway ◽  
Cell Lymphoma ◽  
Pi3k Inhibitor ◽  
Pi3k Inhibitor Ly294002 ◽  
Mantle Cell ◽  
Induced Apoptosis

This study aimed to elucidate the antitumor activity of norcantharidin (NCTD) against human mantle cell lymphoma (MCL). Cell proliferation and apoptosis were examined by MTS and flow cytometry. Caspase-3, -8, and -9 activities were detected with a colorimetric caspase protease assay. Apoptotic proteins—including PARP, cyclin D1, Bcl-2 family proteins, XIAP, and cIAP I—were studied by western blot. The phosphoinositide 3 kinase (PI3K) inhibitor LY294002 was used to investigate the involvement of the PI3K/Akt signaling pathway. In vivo studies were performed using Z138 cell xenografts in nude mice. NCTD inhibited proliferation and induced apoptosis of Z138 and Mino cells, both in vitro and in vivo. PI3Kp110αand p-Akt expressions were downregulated by NCTD treatment. NCTD downregulated NF-κB activity by preventing NF-κB phosphorylation and nuclear translocation. This effect was correlated with the suppression of NF-κB-regulated gene products, such as cyclin D1, BAX, survivin, Bcl-2, XIAP, and cIAP. This phenomenon was blocked by the PI3K inhibitor LY294002. Our results demonstrated that NCTD can induce growth arrest and apoptosis in MCL cells and that the mechanism may involve the PI3K/Akt/NF-κB signaling pathway. NCTD may have therapeutic and/or adjuvant therapeutic applications in the treatment of MCL.

scholarly journals Antiproliferative Effect of Androgen Receptor Inhibition in Mesenchymal Stem-Like Triple-Negative Breast Cancer

2016 ◽  
Vol 38 (3) ◽  
pp. 1003-1014 ◽  
Author(s):  
Aiyu Zhu ◽  
Yan Li ◽  
Wei Song ◽  
Yumei Xu ◽  
Fang Yang ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Androgen Receptor ◽  
Cyclin D1 ◽  
Cancer Cells ◽  
Triple Negative Breast Cancer ◽  
Breast Cancer Cells ◽  
Triple Negative

Background/Aims: Androgen receptor (AR), a steroid hormone receptor, has recently emerged as prognostic and treatment-predictive marker in breast cancer. Previous studies have shown that AR is widely expressed in up to one-third of triple-negative breast cancer (TNBC). However, the role of AR in TNBC is still not fully understood, especially in mesenchymal stem-like (MSL) TNBC cells. Methods: MSL TNBC MDA-MB-231 and Hs578T breast cancer cells were exposed to various concentration of agonist 5-α-dihydrotestosterone (DHT) or nonsteroidal antagonist bicalutamide or untreated. The effects of AR on cell viability and apoptosis were determined by MTT assay, cell counting, flow cytometry analysis and protein expression of p53, p73, p21 and Cyclin D1 were analyzed by western blotting. The bindings of AR to p73 and p21 promoter were detected by ChIP assay. MDA-MB-231 cells were transplanted into nude mice and the tumor growth curves were determined and expression of AR, p73 and p21 were detected by Immunohistochemistry (IHC) staining after treatment of DHT or bicalutamide. Results: We demonstrate that AR agonist DHT induces MSL TNBC breast cancer cells proliferation and inhibits apoptosis in vitro. Similarly, activated AR significantly increases viability of MDA-MB-231 xenografts in vivo. On the contrary, AR antagonist, bicalutamide, causes apoptosis and exerts inhibitory effects on the growth of breast cancer. Moreover, DHT-dependent activation of AR involves regulation in the cell cycle related genes, including p73, p21 and Cyclin D1. Further investigations indicate the modulation of AR on p73 and p21 mediated by direct binding of AR to their promoters, and DHT could make these binding more effectively. Conclusions: Our study demonstrates the tumorigenesis role of AR and the inhibitory effect of bicalutamide in AR-positive MSL TNBC both in vitro and in vivo, suggesting that AR inhibition could be a potential therapeutic approach for AR-positive TNBC patients.

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