ORCID Profile
0000-0001-8757-1583
Current Organisation
Garvan Institute of Medical Research
Does something not look right? The information on this page has been harvested from data sources that may not be up to date. We continue to work with information providers to improve coverage and quality. To report an issue, use the Feedback Form.
Publisher: American Society of Hematology
Date: 13-11-2019
DOI: 10.1182/BLOOD-2019-132160
Abstract: Introduction Despite recent advances in the treatment of chronic lymphocytic leukemia (CLL), a significant proportion of patients still relapse with drug-resistant disease. Patients with deletions and/or mutations in TP53 remain a poor prognostic sub-group. There remains a need for on-going research on identifying novel treatment strategies. We have investigated the therapeutic potential of TR57 (Madera Therapeutics, USA), as a single agent and in combination with the Bcl-2 inhibitor venetoclax in CLL. TR57 is an inhibitor of the integrated stress response (ISR) and has shown efficacy in pre-clinical studies of breast cancer. Methods TR57 and venetoclax, as single agents or in combination, were studied against primary CLL cells co-cultured with CD40L-expressing fibroblasts to mimic the tumour microenvironment (TME). The effects of the drugs were also assessed against an OSU-CLL TP53 knock-out cell line generated using CRISPr Cas-9. Cell viability was assessed using the mitochondrial membrane potential dye DiIC1(5), propidium iodide (PI) and flow cytometry. Cytotoxic synergy between TR57 and venetoclax was determined by calculating combination indices (CI) using the CompuSyn software, with CI values of indicative of synergy. Primary CLL cells were stimulated into cycle primary using Dsp30 in combination with IL-2. Cell cycle distribution and proliferation were analysed by flow cytometry using PI and CFSE, respectively. The migratory and adhesive capacities of primary CLL cells was assessed using stroma-derived factor 1a and by assessing expression of CXCR4 and CD49d. The mechanisms of the synergy between TR57 and venetoclax were studied by immunoblotting. Statistical analyses were performed using the students t-test with P-values of 0.05 considered significant. Results TR57 was cytotoxic towards primary CLL cells in a nanomolar range, with IC50 values of 38 ± 1.38 nM and 287 ± 50.45 nM against cells in medium and stromal cell co-culture, respectively. No significant difference was observed in the sensitivity of s les with ATM or TP53 aberrations (n=12). Synergy between TR57 and venetoclax against CLL cells in stromal cell co-culture was consistent with a significant (P 0.001) decrease in the IC50 for both drugs (Figure 1A). A CI value of 0.13 was calculated at a fractional effect of 0.5. TR57 was cytotoxic towards OSU-CLL and OSU-CLLTP53ko cells, with IC50 values of 3.98 ± 1.03 nM and 90.7 ± 3.51 nM, respectively. Synergy between TR57 and venetoclax was evident in both lines with a CI = 0.1 at Fa 0.5. Dose-response analyses in the OSU-CLLTP53ko line are shown in Figure 1B. Following stimulation of primary CLL cells with Dsp30/IL-2 we observed a significant (P 0.01) increase in the proportion of cells in S, G2 and M phases, which was consistent with an increase in cell proliferation. TR57 and venetoclax in combination had a greater effect than in idual drug treatments, significantly reduced the proportion of cells in these cell cycle phases and the proliferative fraction of cells. TR57 and venetoclax in combination also had a significantly greater effect on the migratory capacity (P 0.05) of CLL cells and on the expression of CXCR4 and CD49d (P 0.001) than either drug as a single agent. Immunoblotting of primary CLL and OSU-CLL cells showed that treatment with TR57 decreased expression of Grp78, which supports the notion that this drug may function through inhibition of the ISR. We also observed that TR57, alone and in combination with venetoclax, down-regulated the expression of the pro-survival Mcl-1 and Bcl-2 proteins, up-regulated expression of the pro-apoptotic Noxa and Bax proteins and inhibited the phosphorylation of AKT and ERK1/2-MAPK. Conclusions The data presented demonstrate that TR57 is cytotoxic towards CLL cells under in vitro conditions that mimic the TME and cells with lesions of the TP53 pathway. The synergy observed between TR57 and venetoclax suggests that the drug combination may be highly effective at limiting the survival and proliferation of CLL cells as well as their ability to migrate to, and be retained within, the TME. The mechanisms of this synergy include a shift towards a pro-apoptotic balance in Bcl-2 family proteins and inhibition of signalling via the AKT and ERK1/2-MAPK pathways. Collectively, these data suggest that TR57 alone and in combination with venetoclax may be a highly effective treatment strategy for high risk CLL. Iwanowicz: Madera Therapeutics, LLC: Other: President Ownership.
Publisher: OAE Publishing Inc.
Date: 2020
Publisher: American Society of Hematology
Date: 13-11-2019
DOI: 10.1182/BLOOD-2019-130082
Abstract: Background The PI3-kinase signaling pathway and the Bcl-2-family of proteins play crucial roles in regulating the survival and proliferation of chronic lymphocytic leukemia (CLL) cells in the bone marrow and lymph nodes. Trials of ibrutinib, idelalisib and venetoclax illustrate the potential of targeting the B-cell receptor (BCR) signaling pathway and Bcl-2, however disease relapse is still common. Several pre-clinical studies and on-going clinical trials [Rogers et al., 2018, Jain et al., 2019] suggest that combinations of BCR inhibitors with venetoclax may be an effective treatment strategy for CLL patients with high risk disease. We sought to investigate the effects of combining idelalisib or the AKT inhibitor MK2206 with venetoclax against CLL cells under in vitro conditions that mimic the tumor microenvironment. Methods Primary CLL cells were co-cultured with CD40L-expressing mouse L-fibroblasts. Cell viability was assessed using the mitochondrial membrane potential dye DilC1(5), propidium iodide and flow cytometry (n = 6). Synergy between idelalisib or MK2206 and venetoclax was evaluated by calculating combination indices (CI) using the Compusyn software. The mechanisms of action of the drugs and synergies between the drugs were investigated by immunoblotting (n = 6). Results Venetoclax was highly synergistic in combination with idelalisib or MK2206 against CLL cells co-cultured with CD40L-fibroblasts, with CI values of 0.2 and 0.5 at a fractional effect of 0.9, respectively (Figure 1). This synergy was consistent with a significant (P 0.05) reduction in the IC50 for venetoclax, idelalisib and MK2206. Immunoblotting suggests that MK2206, as a single agent or in combination with venetoclax, was more effective than idelalisib in inhibiting the phosphorylation of AKT and NF-κB. Both MK2206 and idelalisib as single agents and in combination with venetoclax significantly reduced expression of Mcl-1 and Bfl-1, two pro-survival members of the Bcl-2 family of proteins in primary CLL cells co-cultured with CD40L-fibroblasts. Conclusions The synergy observed, which was associated with a significant decrease in the IC50s for idelalisib and MK2206, may mitigate some of the toxicities associated with PI3-kinase pathway inhibitors. Comparison of the two PI3-kinase-pathway inhibitors suggests that MK2206 may be more effective than idelalisib at blocking BCR-mediated signaling as a single agent and in combination with venetoclax. The mechanisms underlying the synergy include down-regulation of expression of Bcl-2 family proteins that are not targeted by venetoclax as a single agent. The data presented support the rationale for on-going and future clinical trials of combination therapies incorporating a PI3-kinase inhibitor with venetoclax for the treatment of high risk CLL. Figure 1 No relevant conflicts of interest to declare.
Publisher: Informa UK Limited
Date: 16-01-2019
DOI: 10.1080/10428194.2018.1542148
Abstract: Several key pathways mediate signaling via the B-cell receptor, including the mitogen-activated protein kinase-ERK1/2 pathway. However, inhibition of MEK1/2, a key component of the MAPK-ERK1/2 signaling cascade, results in paradoxical activation of AKT in chronic lymphocytic leukemia (CLL) cells. In the current study we demonstrate synergy between the MEK1/2 inhibitor binimetinib and the AKT inhibitor MK2206, which combined induce apoptosis of primary CLL cells and restrict the cell cycle progression and proliferation of the OSU-CLL cell line. The mechanisms of action of the drug combination involve dual inhibition of MAPK-ERK1/2 and AKT signaling and down-regulation of Mcl-1 expression. Collectively, these data suggest that dual inhibition of MEK1/2 and AKT may represent a therapeutic option for CLL, capable of overcoming the pro-survival effects of the lymph node and bone marrow microenvironments.
Publisher: American Society of Hematology
Date: 02-12-2016
DOI: 10.1182/BLOOD.V128.22.4059.4059
Abstract: The functional or genetic inactivation of p53 h ers human tumor treatment. Therefore, novel therapeutic strategies are needed. ONC201 is a p53-independent inducer of apoptosis that is the founding member of the imipridone class of novel anti-cancer compounds, which possess a unique pharmacophore. We discovered that ONC201 exerts anti-tumor effects via ATF4 induction through activation of an atypical integrated stress response (ISR) (Ishizawa et al. and Kline et al, Sci Signal, 2016). Several clinical trials of ONC201 are ongoing in advanced cancers, showing a promising safety profiling and signs of clinical activity in both solid tumors and hematopoietic malignancies. In this study, we investigated the effects of ONC212, which has emerged as a highly potent member of the imipridone family, in preclinical models of hematological malignancies. ONC212 exerted potent and prominent apoptogenic effects on acute myeloid leukemia (AML) and mantle cell lymphoma (MCL) cell lines (e.g., ED50s of 141.0 nM in p53 wild-type OCI-AML3 cells, 105.7 nM in MOLM13 cells, and 265.2 nM in p53-null JeKo-1 cell lines). Time course analysis of apoptosis in OCI-AML3 cells showed that ONC212 takes more than 36 hours to start to induce apoptosis, which is similar to observations with ONC201. Next, we further examined similarities between ONC212 and ONC201 by evaluating the in vitro efficacy of ONC212 in ONC201-resistant (ONC201-R) cell lines that we have generated by chronic exposure of MCL and AML cell lines to ONC201, of which ED50s for ONC201 treatment at 72 hrs were all 5 μM. Interestingly, the ONC201-R cell lines were more resistant to ONC212 than the isogenic ONC201-naïve cells (Figure 1), indicating that these cell lines are cross-resistant to ONC212. We previously proved that increased protein translation of the transcription factor ATF4 is one of the major molecular events involved in ONC201-induced apoptosis (Ishizawa et al., Sci Signal, 2016). Similarly, ATF4 protein abundance was increased by 24-hour treatment with ONC212. DDIT3 (CHOP) gene, a target of ATF4, was transcriptionally upregulated in parallel with its target genes GADD34, DR5 and TRIB3 in ONC212-treated JeKo-1 and OCI-AML3 cells by 24 hrs after treatment (Figure 2). Of note, ONC201 was reported to transcriptionally induce TRAIL in a p53-independent manner in solid tumors (Allen et al., Sci Transl Med, 2013), but it was not operational in hematological cell lines (Ishizawa et al., Sci Sig 2016). Consistently, we also confirmed that ONC212 does not increase TRAIL mRNA in MCL (JeKo-1) and AML (OCI-AML3) cells. BCL-2 is a protective factor for cells under endoplasmic reticulum stress, which is one way to activate ISR. Therefore, we investigated whether the BCL-2 inhibitor ABT-199 sensitizes hematopoietic malignant cells to ONC212. Apoptosis was significantly higher in the combination than either drug alone in MCL and AML cell lines even in THP-1 and OCI-AML3 cells that are relatively resistant to ONC201/212 and/or ABT-199 (Figure 3), suggesting that this combination could overcome the resistance to either of agents. Indeed, the combination was also synergistic in the OCI-AML3 ONC201-R cell line (Figure 3). Taken together, our preclinical studies suggest that ONC212 is a promising and potent new member of the impridone class of anti-cancer compounds that warrants further development in hematological malignancies. The combination of ONC212 with ABT-199 is attractive, considering that acquired resistance after a short-term response remains a clinical challenge with ABT-199. Konopleva: AbbVie: Research Funding Genentech: Research Funding. Allen:Oncoceutics Inc.: Employment. Stogniew:Oncoceutics Inc.: Employment, Equity Ownership. Andreeff:Oncoceutics Inc.: Membership on an entity's Board of Directors or advisory committees.
Publisher: Wiley
Date: 14-01-2021
DOI: 10.1002/JHA2.160
Abstract: Despite advances in therapy, a significant proportion of patients with chronic lymphocytic leukemia (CLL) relapse with drug resistant disease. Novel treatment approaches are required, particularly for high risk disease. The imipridones represent a new class of cancer therapy that has been investigated in pre‐clinical and clinical trials against a range of different cancers. We investigated the effects of the imipridone, ONC‐212, against CLL cells cultured under conditions that mimic aspects of the tumour microenvironment and a TP53 ko CLL cell line (OSU‐CLL‐ TP53 ko). ONC‐212 induced dose‐dependent apoptosis, cell cycle arrest and reduced the migration of CLL cells in vitro, including cells from patients with TP53 lesions and OSU‐CLL‐ TP53 ko cells. The effects of ONC‐212 were associated with protein changes consistent with activation of the mitochondrial protease, CIpP, and the integrated stress response. We also observed inhibition of pathways downstream of the B‐cell receptor (BCR) (AKT and MAPK‐ERK1/2) and a pro‐apoptotic shift in the balance of proteins of the BCL2 family of proteins (BCL2, MCL1, BCLxL, BAX and NOXA). In conclusion, the study suggests ONC‐212 may represent an effective treatment for high risk CLL disease by inhibiting multiple facets of the BCR signaling pathway and the pro‐survival effects of the BCL2‐family proteins.
Publisher: Public Library of Science (PLoS)
Date: 24-02-2017
Publisher: Frontiers Media SA
Date: 20-12-2017
Publisher: Elsevier BV
Date: 11-2021
DOI: 10.1016/J.JEP.2021.114409
Abstract: The edible plant Opuntia dillenii (Ker Gawl.) Haw. commonly known as Nagphana, belongs to the Cactaceae family. It is traditionally used to treat various ailments including inflammation, gastric ulcers, diabetes, hepatitis, asthma, whooping cough and intestinal spasm. Despite its traditional use in various countries, detailed toxicological studies of O. dillenii cladode are few. Thus in the current study, toxicity of O. dillenii cladode derived methanol extract, fractions and its α-pyrones: opuntiol and opuntioside have been addressed. The test agents were assessed using both in vitro and in vivo toxicity assays. MTT on human embryonic kidney cell line (HEK-293), tryphan blue exclusion in rat neutrophils, Cytokinesis-B block micronucleus (CBMN) in human lymphocytes and genomic DNA fragmentation using agarose gel electrophoresis were performed. In acute toxicity test, mice orally received extract (5 g/kg) for 7 days followed by measurements of relative organ weight, biochemical (blood profile, liver and kidney function test) and histological studies (liver and kidney) were carried out. Rat bone marrow micronucleus genotoxicity assay was also conducted. O. dillenii derived test agents were non-cytotoxic and had no effect on the integrity of DNA. Methanol extract (5 g/kg) orally administered in mice did not cause any significant change in relative organ weights, biochemical parameters and liver and kidney histology as compared to vehicle control. In parallel, extract did not stimulate micronuclei formation in rat bone marrow polychromatic erythrocytes. These results led to conclude that edible O. dillenii extract is non-toxic via the oral route and appears to be non-cyto-, hepato-, nephro- or genotoxic, thereby supporting its safe traditional use against various ailments. Therefore, opuntiol and opuntioside may serve as lead compounds in designing new drug(s) derived from edible plants.
Publisher: American Society of Hematology
Date: 21-10-2020
DOI: 10.1182/BLOODADVANCES.2019001369
Abstract: The B-cell receptor signaling pathway and dysregulation of the Bcl-2 family of proteins play crucial roles in the pathogenesis of chronic lymphocytic leukemia (CLL). Despite significant advances in the treatment of the disease, relapse and drug resistance are not uncommon. In the current study, we investigated the dual PI3/PIM kinase inhibitor IBL-202 in combination with venetoclax as a treatment option for CLL using both primary CLL cells and TP53-deficient OSU-CLL cells generated using the CRISPR-Cas9 system. IBL-202 and venetoclax were highly synergistic against primary CLL cells cocultured with CD40L fibroblasts (combination index [CI], 0.4, at a fractional effect of 0.9) and TP53-knockout (KO) OSU-CLL cells (CI, 0.5, at a fractional effect of 0.9). Synergy between the drugs was consistent, with a significant (P & .05) reduction in the 50% inhibitory concentration for both drugs. IBL-202 and venetoclax in combination induced cell-cycle arrest and slowed the proliferation of both wild-type and TP53-KO cell lines. The drug combination inhibited AKT phosphorylation, reduced expression of Bcl-xL and NF-κB, and increased the Noxa/Mcl-1 ratio. Downregulation of CXCR4 was consistent with inhibition of the SDF-1α–induced migratory capacity of CLL cells. Synergy between IBL-202 and venetoclax against primary CLL cells cultured under conditions that mimic the tumor microenvironment suggests this drug combination may be effective against CLL cells within the lymph nodes and bone marrow. Furthermore, the efficacy of the combination against the TP53-KO OSU-CLL cell line suggests the combination may be a highly effective treatment strategy for high-risk CLL.
Publisher: Informa UK Limited
Date: 05-11-2021
Publisher: Cold Spring Harbor Laboratory
Date: 07-03-2022
DOI: 10.1101/2022.03.07.483345
Abstract: Despite advances in treatment, a significant proportion of patients with chronic lymphocytic leukaemia (CLL) will relapse with drug-resistant disease. Recent studies demonstrate that the imipridones ONC-201 and ONC-212 and the more potent TR-compounds are effective against a range of different cancers, including acute myeloid leukaemia and tumours of the brain, breast, and prostate. These drugs induce cell death through inhibition of mitochondrial function and activation of the mitochondrial protease, caseinolytic protease (CIpP), and the unfolded protein response (UPR). Here we demonstrate that a drug in this class, TR-57, has efficacy as a single agent and is synergistic with venetoclax against CLL cells cultured under in vitro conditions that mimic the tumour microenvironment. The inhibitory effects of TR-57 on cell survival, proliferation and migration were irrespective of poor-risk features, including aberrations of TP53. Changes in protein expression suggest the mechanisms of action of TR-57 and its synergy with venetoclax involve activation of the UPR, inhibition of the AKT and ERK1/2 pathways and a pro-apoptotic shift in expression of proteins of the BCL-2 family. The study suggests TR-57, as a single agent and in combination with venetoclax, may represent an effective treatment option for CLL, including for patients with poor-risk disease.
Location: Pakistan
No related grants have been discovered for NARJIS FATIMA RIZWAN.