PTH- PTHR1 Axis Control on Anti-Myeloma Effect of Proteasome Inhibitors

Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 5017-5017
Author(s):  
Maurizio Zangari ◽  
Fang Xiao ◽  
Ye Yang ◽  
Hongwei Xu ◽  
Guido J. Tricot ◽  
...  
Keyword(s):  
Multiple Myeloma ◽  
Conflicts Of Interest ◽  
Single Agent ◽  
Proteasome Inhibitors ◽  
In Vitro Study ◽  
Inhibitory Effect ◽  
Tumor Burden ◽  
Control Group

Abstract Abstract 5017 Multiple myeloma (MM) is a plasma cell malignancy with high osteolytic capacity and impaired bone formation. Our recent studies have demonstrated that PTH serum increases are associated with Bortezomib responses in multiple myeloma patients, indicating a possible role of PTH in anti myeloma effect of Bortezomib. We first tested the 5TGM1 cell line for sensitivity to bortezomib, PTH, and [TYR34]bPTH-(7-34) bovine (a specific PTHR1 inhibitor) in various combinations. In an in vitro study, 5TGM1 cells were sensitive to cytotoxicity of bortezomib and PTH in a dose dependent fashion. TYR compound was found to have no effect as single agent on 5TGM1 cell survival, but was able to partially block the inhibitory effect of bortezomib on cell growth (Figure 1). In an in vivo study using the 5TGM1 C 57BL/KaLwRijmice, we tested PTH-PTHR1 axis on bortezomib anti-myeloma activity. As shown in Figure 1, mice survival was positively affected by bortezomib administration (P = 0.04), and the combination of PTH + bortezomib showed a trend to further improve survival (P = 0.09). Interestingly, the concomitant use of [TYR] compound with bortezomib completely abrogated the efficacy of the proteasome inhibitor on survival. Tumor burden assessed by M-protein levels decreased consistently in mice treated with bortezomib alone, PTH alone, or a combination of PTH + bortezomib compared with the control group treated with PBS (P = 0.003, P = 0.05, P = 0.01 respectively). Importantly the tumor burden in the mice treated with bortezomib was significantly lower than in mice treated with bortezomib plus the PTH inhibitor (TYR), again indicating that the PTHR inhibitor abrogates the effect of Bortezomib on tumor growth. Similar results were obtained using the same systems for other commercially available proteasome inhibitors. Thus, we conclude that the PTH- PTHR1 pathway appears essential for proteasome inhibition activity in myeloma. Our observations may lead to novel treatment approaches in myeloma. Disclosures: No relevant conflicts of interest to declare.

Inhibitory Effect of Resveratrol on the Pharmacokinetics of Ticagrelor in Vivo and Vitro

2021 ◽  
Author(s):  
Peng Wang ◽  
Xiao-Xia Hu ◽  
Ying-hui Li ◽  
Nan-Yong Gao ◽  
Guo-quan Chen ◽  
...  
Keyword(s):  
Rat Liver ◽  
Liver Microsomes ◽  
In Vitro Study ◽  
Inhibitory Effect ◽  
Control Group ◽  
Rat Liver Microsomes ◽  
Sprague Dawley ◽  
Group B

This study was to evaluate the effect of resveratrol on the pharmacokinetics of ticagrelor in rats and the metabolism of ticagrelor in human CYP3A4 and liver microsomes. Eighteen Sprague-Dawley rats were randomly divided into three groups: group A (control group), group B (50mg/kg resveratrol), and group C (150mg/kg resveratrol ). After 30 minutes administration of resveratrol, a single dose of ticagrelor (18mg/kg) was administered orally. The vitro experiment was performed to examine the influence of resveratrol on ticagrelor metabolism in CYP3A4*1, human, and rat liver microsomes. Serial biological samples were assayed by validated UHPLC-MS/MS methods. In vivo study, the AUC and Cmax of ticagrelor in group B and C appeared to be significantly higher than the control group, while Vz/F and CLz/F of ticagrelor in group B and C were significantly decreased. In vitro study, resveratrol exhibited an inhibitory effect on CYP3A4*1, human and rat liver microsomes. The IC50 values of resveratrol were 56.75μM，69.07μM and 14.22μM, respectively. Our results indicated that resveratrol had a inhibitory effect on the metabolism of ticagrelor in vitro and vivo. It should be paid more attention to the clinical combination of resveratrol with ticagrelor and ticagrelor plasma concentration should be monitored to avoid the occurrence of adverse reaction.

Triple Combinations of the HDAC Inhibitor Panobinostat (LBH589) + Dexamethasone with Either Lenalidomide or Bortezomib Are Highly Effective in a Multiple Myeloma Mouse Model.

Blood ◽  
2007 ◽  
Vol 110 (11) ◽  
pp. 1514-1514
Author(s):  
Enrique M. Ocio ◽  
David Vilanova ◽  
Laura San-Segundo ◽  
Patricia Maiso ◽  
Mercedes Garayoa ◽  
...  
Keyword(s):  
Multiple Myeloma ◽  
Median Survival ◽  
Hdac Inhibitor ◽  
Single Agent ◽  
Body Weight Loss ◽  
Control Group ◽  
Synergistic Activity ◽  
Median Volume

Abstract Introduction Panobinostat (LBH589) is a novel histone deacetylase (HDAC) inhibitor being evaluated in clinical trials in hematological and solid malignancies. In multiple myeloma (MM), investigators have demonstrated its in vitro antimyeloma effect in cell lines and patients cells. Cancer treatment is typically based on the concept of combining agents with different mechanisms of action to overcome drug resistance. This was the rationale of the present study in which the in vitro and in vivo benefit of combinations of pabinostat with conventional antimyeloma agents has been explored. Material and Methods The potential in vitro synergism of pabinostat with 6 antimyeloma agents (melphalan, doxorubicin, dexamethasone, thalidomide, lenalidomide, bortezomib) was analyzed in MM1S cell line. The two most favorable combinations were tested in 120 NOD/SCID mice implanted with a human subcutaneous plasmocytoma. Mice were randomized into 12 treatment groups. Drugs were given ip, 5 days/week × 7 weeks. Doses were: pabinostat: 10 mg/Kg × 3 weeks and 5 mg/Kg afterwards; dexamethasone (D): 1 mg/Kg; bortezomib (B): 0.1 mg/Kg; and lenalidomide (L): 15 mg/Kg. Tumor volumes clinical features and weight were monitored three times a week. Mice were sacrificed when their tumors reached 2 cm. Immunohistochemistry was performed in selected tumors. Results Three agents potentiated the effect of pabinostat in vitro: bortezomib, dexamethasone and, to a lesser extent, lenalidomide. Moreover, the triple combination of pabinostat+L+D and pabinostat+B+D resulted in high synergistic activity. These studies provided the rationale for testing these combinations in vivo: Single agent pabinostat at a dose of 10 mg/Kg completely abrogated the growth of plasmocytomas without significant toxicity. In fact, after three weeks of treatment, the median volume of tumors in the pabinostat group was 163±75 mm3 as compared to 1891±1182 mm3 in the control group (p=0.001). Immunohistochemistry of pabinostat treated tumors revealed a decrease in BrdU uptake, an increase in histone acetylation and phosphorylation of H2AX suggesting DNA damage. This antiproliferative action was associated with survival advantage: median survival 70±1.8 vs 30±2.1 days (p<0.001) for the pabinostat and vehicle treated groups respectively. Subsequently the dose of pabinostat was decreased by 50% in order to gain further insights into the potential advantage of the combinations. Interestingly, the addition of D and suboptimal doses of either B or L significantly improved the antimyeloma effect of pabinostat. In this sense, median survival increased up to 86±2.6 days in pabinostat+D+B (p<0.001) and 88±1.2 days for pabinostat+D+L (p<0.001). The efficacy of these triple combinations was significantly higher than any of the respective double combinations (pabinostat+D; pabinostat+B; pabinostat+L; B+D; L+D). Some of these combinations (including or not pabinostat) initially induced a slight toxicity (5%–15% body weight loss) which spontaneously recovered after the third week of treatment. Conclusion Combinations of pabinostat + dexamethasone with either bortezomib or lenalidomide are safe and display promising antimyeloma efficacy. This study provides the rationale for the clinical development of triple combinations of these drugs to improve the outcome of MM patients.

Alpha Lipoic Acid (ALA) Inhibits the Anti-Myeloma Effects of Bortezomib.

Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 3832-3832 ◽  
Author(s):  
Jeffrey A Steinberg ◽  
Jing Shen ◽  
Eric Sanchez ◽  
Haiming Chen ◽  
Zhi-Wei Li ◽  
...  
Keyword(s):  
Cell Viability ◽  
Cell Lines ◽  
Vascular Dysfunction ◽  
Single Agent ◽  
Inhibitory Effect ◽  
Control Group ◽  
Treatment Schedule ◽  
20 Nm

Abstract Abstract 3832 Poster Board III-768 Introduction ALA is an antioxidant often used in the management of peripheral neuropathy (PN) for patients with multiple myeloma (MM). A clinical trial evaluating ALA in diabetic neuropathy showed this drug to be effective for patients with both somatic and autonomic neuropathies. It also normalized the endoneural blood flow, reduced oxidative stress and improved vascular dysfunction. Bortezomib (Velcade®), the first-in-class proteasome inhibitor (PI), which is approved for the treatment of patients with MM, may cause PN. As a result, patients are often treated empirically with ALA. In this study, we investigated whether ALA has any impact on the anti-MM effects of bortezomib. Methods First, cells from the MM cell lines RPMI8226 and MM1S (1×105 cells per 100μl) were treated with ALA alone to determine whether ALA had any effects on their growth as determined with an MTS assay. MM cells were plated in a 96-well plate using serum-free media. The cells were treated with either media alone or ALA at concentrations ranging from 1 to 1000 μM for 48 hours. The acidity of ALA at these doses was determined and if the pH was less than 7, we neutralized it using NaOH. Second, we measured the proliferation of cells exposed to bortezomib alone and combinations of a fixed concentration of bortezomib and escalating concentrations of ALA. Results The exposure of cells to ALA alone had a stimulatory effect on the growth of both MM cell lines in vitro. ALA alone at 1000 μM resulted in an increase in cell viability of MM1S cells by approximately 10% when compared to the control group. ALA alone also stimulated the growth of RPMI8226 cells but at much lower concentrations than observed for MM1S. Compared to untreated cells, there was an increase in cell viability with ALA at concentrations as low as 1 μM and a concentration dependent increase at concentrations of 1, 10, 100, and 1000 μM in RPMI8226 cells. At the highest concentration (1000 μM) of ALA, cell viability increased 150% when compared to RPMI8226 cells incubated with media alone. Next, we evaluated the effect of ALA on bortezomib's anti-MM activity. As a single agent, bortezomib reduced MM1S (20 nM) and RPMI8226 (5 nM) cell viability by 93% and 70% respectively. When ALA was added at a clinically achievable concentration (100 μM) to bortezomib (RPMI8226, 5 nM; MM1S, 20 nM), a reduction in the anti-MM effects of bortezomib on these cell lines was observed when compared to bortezomib treatment alone. Compared to bortezomib alone, the combination of ALA plus bortezomib doubled cell viability (increased RPMI8226 and MM1S cell viability from 32.5% to 65% and 7.5% to 15%, respectively). These negative effects of ALA on bortezomib's anti-MM activity were consistently observed in multiple experiments involving both of these cell lines evaluating concentrations of ALA ranging from 100 to 1000 μM and bortezomib ranging from 5 to 20 nM. Conclusions Our data suggest that ALA has the potential to antagonize the anti-MM effects of bortezomib based on our in vitro results using MM cell lines. Thus, it is possible that ALA could negatively impact the therapeutic benefit of bortezomib for MM patients and this requires further study especially if ALA is accepted as an intervention in bortezomib-related neuropathy. We are currently completing studies evaluating primary MM patients' tumor cells in vitro and our human MM xenograft models in vivo to further validate this impact of ALA on bortezomib's anti-MM activity and whether changes in treatment schedule of these drugs may prevent this inhibitory effect from occurring. In addition, because part of bortezomib's anti-tumor effects are related to reactive oxygen species (ROS) levels, we are evaluating whether the inhibitory effects of ALA on this PI may be overcome by increasing intracellular ROS levels. Disclosures: Hilger: Millennium Pharmaceutcals: Employment. Berenson:Millennium Pharmaceuticals, Inc.: Consultancy, Honoraria, Research Funding, Speakers Bureau.

In Vitro and In Vivo Efficacy of a Novel Orally Bioavailable Beta-Catenin Inhibitor-BC2059- As Monotherapy or in Combination with Proteasome Inhibitors in Multiple Myeloma

Blood ◽  
2015 ◽  
Vol 126 (23) ◽  
pp. 1816-1816
Author(s):  
Ioanna Savvidou ◽  
Tiffany T. Khong ◽  
Stephen K. Horrigan ◽  
Andrew Spencer
Keyword(s):  
Multiple Myeloma ◽  
Cell Death ◽  
Single Agent ◽  
Proteasome Inhibitors ◽  
Canonical Pathway ◽  
Beta Catenin ◽  
Dependent Manner ◽  
Canonical Wnt

Abstract Background: The currently available treatment options are unlikely to be curative for the majority of Multiple Myeloma (MM) patients, emphasizing a continuing role for the introduction of investigational agents that overcome drug resistance. The canonical Wnt/β-catenin signalling pathway has been found to be dysregulated in MM, and its activation is associated with advanced stage MM, providing a rationale to evaluate the novel β-catenin inhibitor BC2059 in mono- and combination therapy with proteasome inhibitors in vitro and in vivo. Methods and Results: We evaluated the activation status of the canonical Wnt pathway in 12 genetically heterogeneous Human Myeloma Cell Lines (HMCL) by assessing the expression of β-catenin protein in the nuclear compartment (active form). This showed that nuclear β-catenin was present in all HMCL tested and absent in plasma cells derived from a healthy donor. Moreover, additional stimulation of the canonical pathway with rhWnt3a was shown to be pro-proliferative, in contrast, no proliferation was seen with activation of the non canonical pathway following treatment with rhWnt5a. BC2059 (50nM to 500nM) induced apoptosis of all 12 HMCL and was able to inhibit the proliferation of all HMCL tested in a dose and time dependent manner assessed by MTS assay and viable enumeration with trypan blue (IC50: 53nM to 247nM). Mimicking the bone marrow (BM) microenvironment by co-culturing HMCL with the immortalised human stromal cell line HS-5, BC2059 was able to overcome the protective effect of HS-5 (for example KMS18 at IC90=220nM had no stromal pro-survival effect). Similarly, BC2059 was able to abolish the pro-proliferative effect of rh-Wnt3a or conditioned media derived from MM patients' BM when used at doses >100nM or 50nM, respectively. BC2059 facilitated the degradation of β-catenin protein in the nuclear cellular compartment ( >50% decrease of nuclear β-catenin in KMS18 treated with 1.5xIC50 when compared with untreated cells), furthermore, using a reporter assay we showed that BC2059 inhibited TCF/LEF transcriptional activity in a dose-dependent manner and decreased the transcription of axin2, a down-stream target gene of β-catenin - 78% reduction in KMS18 cells treated with 1.5x IC50 when compared to untreated controls. BC2059-induced HMCL cell death was associated with activation of both the intrinsic and extrinsic caspase-dependent apoptotic pathways, as shown by the accumulation of the activated forms of caspases 8, 9 and 3 following BC2059 treatment. However, inhibition of the caspase-pathway by the addition of caspase inhibitors (pan-caspase inhibitor Z-VAD, and caspase-3 inhibitor Z-DEVD) could not abolish the pro-necrotic effect of BC2059 or BC2059 plus bortezomib, suggesting a possible role for autophagy-induced cell death. As β-catenin undergoes proteasome-mediated destruction and has been found to increase following bortezomib treatment, we evaluated the effect of combining BC2059 with Bortezomib. The combination was synergistic for 6/8 HMCL tested (e.g. for LP1 CI:0.64-0.55, where CI<1.1=synergism). We also evaluated the effect of the combination of BC2059 with next generation proteasome inhibitors (carfilzomib and marizomib) where it was shown to have synergistic and/or additive effects (e.g. for carfilzomib LP1 CI:0.33-0.99). Single agent BC2059 effectively killed primary MM tumour cells from relapsed/refractory MM patients (n=13) and the combination with bortezomib was synergistic (n=2) with no effect on healthy peripheral blood mononuclear cells (n=4). Finally, BC2059 (10mg/kg) prolonged survival of xenografted NSG mice compared to untreated controls with no major side effects in Wnt/β-catenin dependent tissues (GI track and haematopoiesis). Conclusion: We have demonstrated that BC2059 at nano-molar concentrations has a strong anti-MM effect both in vitro and in vivo and synergises with proteasome inhibitors. These data strongly support the clinical evaluation of BC2059 for the treatment of MM. Disclosures Horrigan: BetaCat Pharmaceuticals: Employment.

scholarly journals Lycorine Downregulates HMGB1 to Inhibit Autophagy and Enhances Bortezomib Activity in Multiple Myeloma

Blood ◽  
2016 ◽  
Vol 128 (22) ◽  
pp. 3265-3265
Author(s):  
Mridul Roy ◽  
Long Liang ◽  
Xiaojuan Xiao ◽  
Yuanliang Peng ◽  
Yuhao Luo ◽  
...  
Keyword(s):  
Multiple Myeloma ◽  
Bone Marrow ◽  
Conflicts Of Interest ◽  
Single Agent ◽  
Xenograft Model ◽  
Hmgb1 Expression ◽  
Resistant Cells

Abstract Multiple myeloma (MM) is the second most prevalent hematologic malignancy, characterized by the infiltration of malignant plasma cells into bone marrow. In spite of current efficient therapeutic regimens, which have significantly increased patients overall survival, the major features inevitably present in MM are the intrinsic and acquired resistance with nearly universal relapse. In addition, the diverse heterogeneous characteristics of this largely incurable disease emphasize the importance of innovative therapies and identification of more effective drugs. Autophagy removes defective cellular organelles, protein aggregates, and intracellular microbes and is associated with cell survival and tumor maintenance. Inhibition of autophagy enhances sensitivity of a number of anticancer agents and induces cell death in MM. High-mobility group box-1 (HMGB1) protein plays an important subcellular localization-dependent role during autophagy. The importance of HMGB1 for induction of autophagy and tumor development has made this protein as a novel target for cancer therapy. Lycorine is a natural alkaloid with significant anti-cancer activity. While previous studies mainly showed lycorine as a potential apoptosis inducer, recent studies stated that apoptosis is not the primary underlying anti-proliferative mechanism of this compound. This led the interest to investigate the role of lycorine on other cell maintenance systems, such as autophagy. In addition single-agent efficacy of lycorine or in combination with other anti-MM agents has not been evaluated in vivo. Herein we investigated the anti-MM effect of lycorine and the role of this natural agent on regulation of autophagy in vitro and in vivo. We found that lycorine inhibits proliferation and induces apoptosis in MM cells with less sensitivity to the normal B-cell at the same concentrations. We also found that lycorine promisingly inhibits autophagy, the mechanism that MM cells use to survive and defeat treatment. We identified HMGB1, an important regulator of autophagy, as the most aberrantly expressed protein after lycorine treatment. Furthermore, we characterized HMGB1 as a critical mediator of lycorine activity against MM. Gene expression profiling (GEP) analysis showed that higher expression of HMGB1 is linked with the poor prognosis of MM. We further confirmed this correlation in human bone marrow CD138+ primary myeloma cells and MM cell lines. Mechanistically, by activating the proteasomal degradation of HMGB1, lycorine induces a rapid turnover of HMGB1. This led to decreased Bcl-2 phosphorylation by MEK-ERK pathway and increased association of Bcl-2 with Beclin-1 resulting in autophagy inhibition and growth attenuation. In addition, we observed higher HMGB1 expression in bortezomib resistant cells. The combination of bortezomib plus lycorine was highly efficient against MM cells and MM cells grown in bone marrow micro-environment. Lycorine showed the capability of inhibiting bortezomib induced autophagy as well as re-sensitizing resistant cells to bortezomib. In agreement with our in vitro observations, in vivo study using human MM xenograft model showed that lycorine is well tolerated, inhibits HMGB1 expression and thereby autophagy and induces enhanced bortezomib activity. These observations indicated lycorine as an effective autophagy inhibitor and revealed that lycorine alone or in combination with bortezomib is a potential therapeutic strategy. Our study supports the feasibility of lycorine in anti-MM treatment and provides a preclinical framework for combining lycorine with bortezomib in clinical setting. Disclosures No relevant conflicts of interest to declare.

scholarly journals Pharmacodynamic, pharmacokinetic, and phase 1a study of bisthianostat, a novel histone deacetylase inhibitor, for the treatment of relapsed or refractory multiple myeloma

2021 ◽  
Author(s):  
Yu-bo Zhou ◽  
Yang-ming Zhang ◽  
Hong-hui Huang ◽  
Li-jing Shen ◽  
Xiao-feng Han ◽  
...  
Keyword(s):  
Multiple Myeloma ◽  
Drug Targets ◽  
Single Agent ◽  
Hdac Inhibitors ◽  
Preclinical Study ◽  
Parp Cleavage ◽  
Rpmi 8226 ◽  
Ongoing Phase

AbstractHDAC inhibitors (HDACis) have been intensively studied for their roles and potential as drug targets in T-cell lymphomas and other hematologic malignancies. Bisthianostat is a novel bisthiazole-based pan-HDACi evolved from natural HDACi largazole. Here, we report the preclinical study of bisthianostat alone and in combination with bortezomib in the treatment of multiple myeloma (MM), as well as preliminary first-in-human findings from an ongoing phase 1a study. Bisthianostat dose dependently induced acetylation of tubulin and H3 and increased PARP cleavage and apoptosis in RPMI-8226 cells. In RPMI-8226 and MM.1S cell xenograft mouse models, oral administration of bisthianostat (50, 75, 100 mg·kg-1·d-1, bid) for 18 days dose dependently inhibited tumor growth. Furthermore, bisthianostat in combination with bortezomib displayed synergistic antitumor effect against RPMI-8226 and MM.1S cell in vitro and in vivo. Preclinical pharmacokinetic study showed bisthianostat was quickly absorbed with moderate oral bioavailability (F% = 16.9%–35.5%). Bisthianostat tended to distribute in blood with Vss value of 0.31 L/kg. This distribution parameter might be beneficial to treat hematologic neoplasms such as MM with few side effects. In an ongoing phase 1a study, bisthianostat treatment was well tolerated and no grade 3/4 nonhematological adverse events (AEs) had occurred together with good pharmacokinetics profiles in eight patients with relapsed or refractory MM (R/R MM). The overall single-agent efficacy was modest, stable disease (SD) was identified in four (50%) patients at the end of first dosing cycle (day 28). These preliminary in-patient results suggest that bisthianostat is a promising HDACi drug with a comparable safety window in R/R MM, supporting for its further phase 1b clinical trial in combination with traditional MM therapies.

scholarly journals Reovirus-induced cell-mediated immunity for the treatment of multiple myeloma within the resistant bone marrow niche

2021 ◽  
Vol 9 (3) ◽  
pp. e001803
Author(s):  
Louise M E Müller ◽  
Gemma Migneco ◽  
Gina B Scott ◽  
Jenny Down ◽  
Sancha King ◽  
...  
Keyword(s):  
Multiple Myeloma ◽  
T Cells ◽  
Immune Responses ◽  
Stromal Cells ◽  
Tumor Burden ◽  
Effector Memory ◽  
In Vivo Model ◽  
Bm Niche

BackgroundMultiple myeloma (MM) remains an incurable disease and oncolytic viruses offer a well-tolerated addition to the therapeutic arsenal. Oncolytic reovirus has progressed to phase I clinical trials and its direct lytic potential has been extensively studied. However, to date, the role for reovirus-induced immunotherapy against MM, and the impact of the bone marrow (BM) niche, have not been reported.MethodsThis study used human peripheral blood mononuclear cells from healthy donors and in vitro co-culture of MM cells and BM stromal cells to recapitulate the resistant BM niche. Additionally, the 5TGM1-Kalw/RijHSD immunocompetent in vivo model was used to examine reovirus efficacy and characterize reovirus-induced immune responses in the BM and spleen following intravenous administration. Collectively, these in vitro and in vivo models were used to characterize the development of innate and adaptive antimyeloma immunity following reovirus treatment.ResultsUsing the 5TGM1-Kalw/RijHSD immunocompetent in vivo model we have demonstrated that reovirus reduces both MM tumor burden and myeloma-induced bone disease. Furthermore, detailed immune characterization revealed that reovirus: (i) increased natural killer (NK) cell and CD8+ T cell numbers; (ii) activated NK cells and CD8+ T cells and (iii) upregulated effector-memory CD8+ T cells. Moreover, increased effector-memory CD8+ T cells correlated with decreased tumor burden. Next, we explored the potential for reovirus-induced immunotherapy using human co-culture models to mimic the myeloma-supportive BM niche. MM cells co-cultured with BM stromal cells displayed resistance to reovirus-induced oncolysis and bystander cytokine-killing but remained susceptible to killing by reovirus-activated NK cells and MM-specific cytotoxic T lymphocytes.ConclusionThese data highlight the importance of reovirus-induced immunotherapy for targeting MM cells within the BM niche and suggest that combination with agents which boost antitumor immune responses should be a priority.

scholarly journals Shortened platelet half-life in multiple myeloma

Blood ◽  
1986 ◽  
Vol 68 (2) ◽  
pp. 514-520
Author(s):  
E Fritz ◽  
H Ludwig ◽  
W Scheithauer ◽  
H Sinzinger
Keyword(s):  
Multiple Myeloma ◽  
Half Life ◽  
Serum Levels ◽  
Statistical Correlation ◽  
Control Group ◽  
Healthy Controls ◽  
Platelet Factor ◽  
Healthy Control

Various defects in platelet function have been reported as being associated with multiple myeloma. In 30 myeloma patients and 15 healthy controls, we investigated platelet survival using in vitro labeling of autologous platelets with 111indium-oxine and measuring the in vivo kinetics of the radioisotope. Significantly shortened platelet half- life in patients averaged 73 hours, while platelet half-life in the healthy controls averaged 107 hours. In myeloma patients, serum levels of thromboxane B2, beta-thromboglobulin, and platelet factor 4 were significantly elevated; aggregation indices were within the pathological range; platelet counts and spleen-liver indices, however, were comparable to those of the healthy control group. No statistical correlation was found between platelet half-life and paraprotein concentrations. Our findings suggest an initial--so far unexplained-- intravascular process of platelet activation and consumption that finally manifests in shortened platelet half-life. It seems that overt thrombocytopenia develops only when the compensatory capacity of the bone marrow finally becomes exhausted. Further studies should be able to elucidate the pathophysiologic processes involved.

scholarly journals Combination of proteasome inhibitors bortezomib and NPI-0052 trigger in vivo synergistic cytotoxicity in multiple myeloma

Blood ◽  
2008 ◽  
Vol 111 (3) ◽  
pp. 1654-1664 ◽  
Author(s):  
Dharminder Chauhan ◽  
Ajita Singh ◽  
Mohan Brahmandam ◽  
Klaus Podar ◽  
Teru Hideshima ◽  
...  
Keyword(s):  
Multiple Myeloma ◽  
Proteasome Inhibitors ◽  
Xenograft Model ◽  
Er Stress Response ◽  
Synergistic Cytotoxicity ◽  
Proteolytic Activities ◽  
Dose Combination ◽  
Inhibition Of Tumor Growth

AbstractOur recent study demonstrated that a novel proteasome inhibitor NPI-0052 triggers apoptosis in multiple myeloma (MM) cells, and importantly, that is distinct from bortezomib (Velcade) in its chemical structure, effects on proteasome activities, and mechanisms of action. Here, we demonstrate that combining NPI-0052 and bortezomb induces synergistic anti-MM activity both in vitro using MM cell lines or patient CD138+ MM cells and in vivo in a human plasmacytoma xenograft mouse model. NPI-0052 plus bortezomib–induced synergistic apoptosis is associated with: (1) activation of caspase-8, caspase-9, caspase-3, and PARP; (2) induction of endoplasmic reticulum (ER) stress response and JNK; (3) inhibition of migration of MM cells and angiogenesis; (4) suppression of chymotrypsin-like (CT-L), caspase-like (C-L), and trypsin-like (T-L) proteolytic activities; and (5) blockade of NF-κB signaling. Studies in a xenograft model show that low dose combination of NPI-0052 and bortezomib is well tolerated and triggers synergistic inhibition of tumor growth and CT-L, C-L, and T-L proteasome activities in tumor cells. Immununostaining of MM tumors from NPI-0052 plus bortezomib–treated mice showed growth inhibition, apoptosis, and a decrease in associated angiogenesis. Taken together, our study provides the preclinical rationale for clinical protocols evaluating bortezomib together with NPI-0052 to improve patient outcome in MM.

scholarly journals Nano-encapsulated tryptanthrin derivative for combined anticancer therapy via inhibiting indoleamine 2,3-dioxygenase and inducing immunogenic cell death

Nanomedicine ◽  
2019 ◽  
Vol 14 (18) ◽  
pp. 2423-2440 ◽  
Author(s):  
Canyu Yang ◽  
Bing He ◽  
Qiang Zheng ◽  
Dakuan Wang ◽  
Mengmeng Qin ◽  
...  
Keyword(s):  
Cell Death ◽  
Single Agent ◽  
Tumor Burden ◽  
Antitumor Efficacy ◽  
In Vivo Studies ◽  
Immunogenic Cell Death ◽  
Indoleamine 2,3 Dioxygenase ◽  
Tumor Tissues

Aim: We developed a polycaprolactone-based nanoparticle (NP) to encapsulate tryptanthrin derivative CY-1-4 and evaluated its antitumor efficacy. Materials & methods: CY-1-4 NPs were prepared and evaluated for their cytotoxicity and associated mechanisms, indoleamine 2,3-dioxygenase (IDO)-inhibitory ability, immunogenic cell death (ICD)-inducing ability and antitumor efficacy. Results: CY-1-4 NPs were 123 nm in size. In vitro experiments indicated that they could both induce ICD and inhibit IDO. In vivo studies indicated that a medium dose reduced 58% of the tumor burden in a B16-F10-bearing mouse model, decreased IDO expression in tumor tissues and regulated lymphocytes subsets in spleen and tumors. Conclusion: CY-1-4 is a potential antitumor candidate that could act as a single agent with combined functions of IDO inhibition and ICD induction.

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