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- Delforoush, Maryam, 1980-, et al.
(författare)
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Expression of possible targets for new proteasome inhibitors in diffuse large B-cell lymphoma
- 2017
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Ingår i: European Journal of Haematology. - : Wiley. - 0902-4441 .- 1600-0609. ; 98:1, s. 52-56
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Tidskriftsartikel (refereegranskat)abstract
- Objectives: Investigating expression of possible targets for proteasome inhibitors in patients with diffuse large B-cell lymphoma (DLBCL) and correlating the findings to clinical parameters and outcome.Methods: Tumour material from 92 patients with DLBCL treated with either R-CHOP like (n = 69) or CHOP like (n = 23) regimens were stained for possible targets of proteasome inhibitors.Results: The primary target molecule of bortezomib, proteasome subunit beta, type 5 (PSMB5), was not detected in the tumour cells in any of the cases but showed an abundant expression in cells in the microenvironment. However, the deubiquitinases (DUBs) of the proteasome, the ubiquitin carboxyl-terminal hydrolase L5 (UCHL5) and the ubiquitin specific peptidase 14 (USP14), were detected in the cytoplasm of the tumour cells in 77% and 74% of the cases, respectively. The adhesion regulating molecule 1 (ADRM1) was detected in 98% of the cases. There was no correlation between the expression of any of the studied markers and clinical outcome or GC/non-GC phenotype.Conclusions: We suggest that UCHL5 and/or USP14 should be further evaluated as new targets for proteasome inhibitors in DLBCL. The lack of expression of PSMB5 on the tumour cells might provide an explanation of the relatively poor results of bortezomib in DLBCL.
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| 3. |
- Delforoush, Maryam, 1980-, et al.
(författare)
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In vitro and in vivo activity of melflufen (J1) in lymphoma
- 2016
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Ingår i: BMC Cancer. - : Springer Science and Business Media LLC. - 1471-2407 .- 1471-2407. ; 16
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Tidskriftsartikel (refereegranskat)abstract
- Background: Melphalan has been used in the treatment of various hematologic malignancies for almost 60 years. Today it is part of standard therapy for multiple myeloma and also as part of myeloablative regimens in association with autologous allogenic stem cell transplantation. Melflufen (melphalan flufenamide ethyl ester, previously called J1) is an optimized derivative of melphalan providing targeted delivery of active metabolites to cells expressing aminopeptidases. The activity of melflufen has compared favorably with that of melphalan in a series of in vitro and in vivo experiments performed preferentially on different solid tumor models and multiple myeloma. Melflufen is currently being evaluated in a clinical phase I/II trial in relapsed or relapsed and refractory multiple myeloma.Methods: Cytotoxicity of melflufen was assayed in lymphoma cell lines and in primary tumor cells with the Fluorometric Microculture Cytotoxicity Assay and cell cycle analyses was performed in two of the cell lines. Melflufen was also investigated in a xenograft model with subcutaneous lymphoma cells inoculated in mice.Results: Melflufen showed activity with cytotoxic IC50-values in the submicromolar range (0.011-0.92 μM) in the cell lines, corresponding to a mean of 49-fold superiority (p < 0.001) in potency vs. melphalan. In the primary cultures melflufen yielded slightly lower IC50-values (2.7 nM to 0.55 μM) and an increased ratio vs. melphalan (range 13–455, average 108, p < 0.001). Treated cell lines exhibited a clear accumulation in the G2/M-phase of the cell cycle. Melflufen also showed significant activity and no, or minimal side effects in the xenografted animals.Conclusion: This study confirms previous reports of a targeting related potency superiority of melflufen compared to that of melphalan. Melflufen was active in cell lines and primary cultures of lymphoma cells, as well as in a xenograft model in mice and appears to be a candidate for further evaluation in the treatment of this group of malignant diseases.
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| 4. |
- Delforoush, Maryam, 1980-, et al.
(författare)
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Inhibition of the 19 S proteasome by bAP-15 in lymphoma cell lines
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Inhibition of activity of proteasome by bortezomib has been shown to selectively kill cancer cells. Bortezomib is approved for the treatment of multiple myeloma and mantle cell lymphoma and the proteolytic 20S core particle of the proteasome, has also been clinically validated as a therapeutic target in oncology. However, despite its acceptable therapeutic index, patients treated with bortezomib show toxic side effects and eventually acquire resistance to the drug. A lot of efforts are currently been made to develop new proteasome inhibitors that perform through mechanisms different from that of bortezomib.We have studied the effects of b-AP15, a novel inhibitor of the deubiquitinase activity in the 19S regulatory subunit of the proteasome, on a panel of nine cell-lines from diffuse large B-cell lymphomas (DLBCL) and three from Hodgkin lymphoma (HL). All cell lines showed a dose dependent reduction of viability. The inhibition of the 19S subunit by b-AP15 resulted, as expected, in accumulation of ubiquitinylated proteins at concentrations close to cytotoxic IC50. Increases in polyubiquitinated proteins were paralleled by increases in the inducible form of heat shock protein 70 (Hsp70B´), and a strong association between Hsp70B´ induction and cleavage of PARP and caspase-3 was observed. These data suggest that proteotoxic stress mediates the sensitivity of lymphoma cells to the deubiquitinase inhibitor b-AP15.The findings in this study suggest that b-AP15 should further evaluated as a drug in lymphoma treatment.
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| 6. |
- Delforoush, Maryam, 1980-
(författare)
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Potential New Drugs in Lymphoma
- 2016
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Lymphomas are malignant tumours arising from cells in the lymphatic system. They are classified as B-cell lymphomas, T-cell lymphomas and Hodgkin lymphoma (HL). Of the B-cell lymphomas, one of the most common is diffuse large B-cell lymphoma (DLBCL). Many patients with lymphomas can be successfully treated however patients who relapse or are refractory have a poor prognosis, warranting further investigations to identify potential targets and develop novel drugs.Picropodophyllin (PPP), a potent and selective inhibitor of IGF-1R, inhibits malignant cell growth with low or no toxicity on normal cells in preclinical models. In paper I, we investigated the potential benefits of using PPP against DLBCL and found that the anti-tumor effects of PPP might possibly be explained by IGF-1R-unrelated mechanism(s). However, the inhibitory effects of PPP on lymphoma cells together with its low toxicity in vivo makes it a promising drug candidate for treatment. Melflufen, a derivative of melphalan, is currently being evaluated in a clinical phase I/II trial in relapsed or refractory multiple myeloma. In paper II, we confirmed previous reports of superior potency of melflufen over melphalan. Being active in cell lines and primary cultures of lymphoma cells as well as in a xenograft model in mice, melflufen considered being a candidate for further evaluation in treatment. bAP-15, a novel inhibitor of proteasome activity, inhibits ubiquitin specific peptidase 14 (USP14) and ubiquitin carboxyl-terminal hydrolase L5 (UCHL5). In paper III, we investigated the activity of b-AP15 in DLBCL and HL cell lines and compared the results to standard drugs used in treatment. Results showed inhibition of the proteasome and growth inhibition/cytotoxicity with IC50-values in the micromolar range. Treatment failure and lack of clinical benefit of proteasome inhibitors like bortezomib in DLBCL patients inspired us investigating for possible new targets, with major focus on proteasome inhibitors in DLBCL. In paper IV, we suggested that UCHL5 and/or USP14, as new targets for proteasome inhibitors in DLBCL, be further evaluated.The findings in this thesis suggest that PPP, Melflufen and b-AP15 are potential candidates for clinical drug development and UCHL5 and/or USP14 are new potential targets for proteasome inhibitors in DLBCL.
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| 7. |
- Strömberg, Thomas, et al.
(författare)
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Picropodophyllin inhibits proliferation and survival of diffuse large B-cell lymphoma cells
- 2015
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Ingår i: Medical Oncology. - : Springer Science and Business Media LLC. - 1357-0560 .- 1559-131X. ; 32:7
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Tidskriftsartikel (refereegranskat)abstract
- Diffuse large B-cell lymphoma (DLBCL) is the most common lymphoma in adults. Although chemotherapy in combination with anti-CD20 antibodies results in a cure rate of 60-70 %, novel treatment approaches are warranted for the remaining patients. The insulin-like growth factor-1 receptor (IGF-1R) and its principal ligands IGF-1 and IGF-2 have been suggested to play pivotal roles in different cancers. However, in DLBCL the importance of this system is less well understood. To assess whether interference with IGF-1R-mediated signaling may represent a therapeutic option for this malignancy, we used a panel of eight DLBCL cell lines together with primary tumor cells derived from lymph nodes in four DLBCL patients. The cells were treated with the cyclolignan picropodophyllin (PPP), a small molecule compound initially described to selectively inhibit the IGF-1R. PPP dose-dependently inhibited proliferation/survival in all cell lines and primary cell preparations. In parallel experiments, the IGF-1R inhibitor NVP-AEW541 and the microtubule-destabilizing compounds podophyllotoxin (PPT) and colchicine were demonstrated to also inhibit growth of the cell lines. Linear regression analysis showed that the responses of the cell lines to PPP correlated with their responses to the microtubule inhibitors PPT and colchicine, but not with the response to NVP-AEW541 or the expression level of surface IGF-1R. Analysis of cell cycle phase distribution revealed that treatment with PPP for only 1 h induced a clear accumulation of cells in the G2/M-phase with a corresponding depletion of the G0/G1-phase. Interestingly, these cell cycle effects could be closely mimicked by using PPT or colchicine. Treatment with PPP led to increased apoptotic cell death in the SU-DHL-6 and U-2932 cell lines, whereas the DB and U-2940 did not undergo apoptosis. However, the DB cells were still killed by PPP, suggesting another mode of cell death for this cell line. The U-2940 cells responded to PPP mainly by inhibition of proliferation. Pretreatment of U-2932 or U-2940 cell lines with PPP at biologically active concentrations did not prevent ligand-induced phosphorylation of IGF-1R at Tyr1131/1136 or its downstream targets AKT and ERK1/2. In contrast, the IGF-1R inhibitor NVP-AEW541 clearly inhibited phosphorylation of IGF-1R and AKT, while ERK1/2 phosphorylation was less affected. Taken together, the inhibitory effects of PPP in DLBCL cells together with its low toxicity in vivo makes it a promising drug candidate in the treatment of this disease. However, we suggest that the primary target of PPP in these cells is not related to inhibition of IGF-1R phosphorylation.
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