Preclinical development of small-molecule CRM1 inhibitors as novel therapy for the treatment of colorectal cancer (CRC).

2011 ◽  
Vol 29 (4_suppl) ◽  
pp. 430-430 ◽  
Author(s):  
S. Shacham ◽  
M. Kauffman ◽  
V. Sandanayaka ◽  
G. Draetta ◽  
S. Shechter ◽  
...  
Keyword(s):  
Antitumor Activity ◽  
Cell Lines ◽  
Small Molecule ◽  
Nuclear Export ◽  
Cysteine Proteases ◽  
Preclinical Development ◽  
Normal Cells ◽  
Regulatory Pathways ◽  
Multiple Tumor ◽  
Hct 116

430 Background: CRM1 (XPO1) is a key nuclear export protein which controls the location of multiple tumor suppressor (TSP) and growth regulatory (GRP) proteins including p53, PI3K/AKT, Wnt/ß-catenin and NF-kB. Forced nuclear expression of TSP and GRP by CRM1 inhibition can lead to apoptosis in cancer cells while sparing normal cells. Methods: Novel small-moleculeCRM1 inhibitors were synthesized and nuclear distribution studies were performed in cells transfected with HIV-rev GFP proteins. Cell proliferation studies were performed in 16 CRC cell lines: LS-123, SW-626, Colo-201, Colo-205, Colo-320DM, Colo-320HSR, Lovo, DLD-1, HCT-15, WiDi, LS-174T, LS-180, SW-620, C2BBe1, HCT-8, HCT-116, and in human peripheral leukocytes (PBMC). Cellular distribution and apoptosis assays were performed on HCT-116. Antitumor activity is assessed in human HCT-116 xenografts in scid-mice. Results: The lead CRM1 inhibitor, KPT-0127, blocks CRM1 mediated nuclear export of HIV-Rev-GFP, FOXO, and p53 with an IC50 of ∼300 nM. KPT-0127 is cytotoxic to various CRC cell lines with EC50s of 0.07-1.1 μM; in 9 CRC lines EC50s were < 0.3 mM. In contrast, normal cell lines and PBMCs had EC50 > 5-20 μM. In HCT- 116 cells, KPT-0127 induces cell cycle arrest at both G1/S and G2/M checkpoints and dose dependently increases nuclear p53, followed by an increase in caspase 3. KTP-0127 10μM shows no significant effect on 37 proteins including several cysteine proteases. In mice, KPT-0127 given by SC injection of 30-100 mg/kg leads to serum levels exceeding the effective CRM1 inhibitory concentration for at least 4 hours and is well tolerated. KPT-0127 given SC to mice bearing HCT-116 colon xenografts results in dose-dependent antitumor activity. Conclusions: The novel small- molecule CRM1 inhibitor KTP-0127 kills CRC lines with multiple TSP, GRP, and oncogenic abnormalities, including p53 mutations/deletions and PTEN deficiency/AKT activation, while sparing normal cells. This likely reflects the ability of CRM1 inhibition to affect multiple critical and non-redundant regulatory pathways. These results support the development of CRM1 inhibitors for the treatment of CRC. IND-enabling CMC and toxicology work are in preparation. [Table: see text]

Preclinical Development of Small-Molecule CRM1 Inhibitors as Novel Therapy for the Treatment of Myeloma and Other Hematological Malignancies

Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 3012-3012
Author(s):  
Sharon Shacham ◽  
Joel G Turner ◽  
Raphael Nir ◽  
Giulio Draetta ◽  
Vincent Sandanayaka ◽  
...  
Keyword(s):  
Multiple Myeloma ◽  
Cell Proliferation ◽  
Antitumor Activity ◽  
Cell Lines ◽  
Small Molecule ◽  
Nuclear Localization ◽  
Nuclear Export ◽  
Myeloma Cells ◽  
Hematological Cancers ◽  
Equity Ownership

Abstract Abstract 3012 Background: CRM1 (XPO1) is a key nuclear export protein which controls multiple tumor suppressor proteins (TSP) and cell proliferation pathways including p53, PI3K/AKT, Wnt/ß-catenin and NF-kB. Further, mislocalization of proteins can abrogate TSP functions and render chemotherapies ineffective. For example, multiple myeloma (MM) cells that are grown at high densities (to mimic the in vivo situation) become resistant to topoisomerase 2 (topo2) inhibitors (e.g., doxorubicin) simply because topo2α is exported from the nucleus. Forcing the nuclear expression of chemotherapy targets, TSP and growth regulatory proteins by CRM1 inhibition can restore drug sensitivity and restore checkpoint control/genome surveying functions. These events lead to apoptosis or autophagy in cancer cells while sparing normal cells. Methods: CRM1 inhibitors were synthesized and nuclear distribution studies were performed in U2OS cells transfected with HIV-rev GFP proteins. Cell proliferation studies were performed in multiple myeloma (MM), leukemia and lymphoma cell lines and in human peripheral blood mononuclear cells (PBMCs). Toxicology studies were performed in several mouse strains. Antitumor activity is assessed in a xenograft model of human MM.1 cells growing in scid-mice. Results: The lead CRM1 inhibitor, KPT-0127, blocks CRM1 mediated nuclear export of HIV-Rev-GFP, FOXO, and p53 with an IC50 of ~300 nM. KPT-0127 is selectively cytotoxic to various hematological cell lines with EC50s in the 0.02–1.0 μM range, and shows limited cytotoxicity in similar studies in normal cell lines (NIH-3T3, MRC5, HUVECs) and PBMCs (EC50 >5-20 μM). KPT-0127 increases the nuclear localization of IkB in HUT-78 leukemia cells and human PBMCs, and inhibits TNF-α secretion in LPS stimulated U937 macrophage derived cells, likely through inhibition of NF-kB signaling. In MM cells grown at high densities which actively export topo2 to the cytoplasm via CRM1, blocking CRM1-dependent transport strongly enhanced topo2 nuclear localization and augmented the apoptotic effects of doxorubicin in <24 hours showing clear synergy between KPT-0127 and the anthracycline. Combination of sublethal concentrations of bortezomib plus KPT-0127 in MM1.S and MM.1R myeloma cells (as well as in Jurkat and HS-Sultan) induced synergistic cytotoxicities. In mice, KPT-0127 given by subcutaneous (SC) injection of 30–100 mg/kg leads to serum levels exceeding the effective CRM1 inhibitory concentration for at least 4 hours. In 5 day repeated dose toxicology studies, SC administration of 100 mg/kg KPT-0127 (QD × 5) was well tolerated in mice with no cutaneous or obvious systemic clinical findings. Modest neutrophilia and mild lymphopenia were seen and no neurologic signs resulted from treatment with KPT-0127. Administration of KPT-0127 SC to mice bearing HCT-116 colon cancer results in dose-dependent antitumor activity. Xenograft studies with MM.1 myeloma cells are underway and will be presented at the meeting. Conclusions: The sensitivity of tumors with multiple TSP and oncogenic abnormalities, including p53 mutations/deletions and PTEN deficiency/AKT activation, to killing with KPT-0127 likely reflects the ability to affect multiple critical and non-redundant regulatory pathways. CRM1 inhibition also forces topo 2 to remain in the nucleus, and increases levels of nuclear IkB antagonizing NF-kB function, thereby reducing the likelihood of resistance development. These results support the development of small molecule, drug-like CRM1 inhibitors for the treatment of MM and other hematological cancers. IND-enabling CMC and toxicology work are expected to begin in early 2011. Disclosures: Shacham: Karyopharm: Employment, Equity Ownership, Patents & Royalties. Nir:Karyopharm: Consultancy. Draetta:Karyopharm: Consultancy. Sandanayaka:Karyopharm: Employment. Shechter:Karyopharm: Employment. Kauffman:Karyopharm: Consultancy, Equity Ownership, Patents & Royalties.

scholarly journals Design, Synthesis, Molecular Modeling and Antitumor Evaluation of Novel Indolyl-Pyrimidine Derivatives with EGFR Inhibitory Activity

Molecules ◽  
2021 ◽  
Vol 26 (7) ◽  
pp. 1838
Author(s):  
Naglaa M. Ahmed ◽  
Mahmoud M. Youns ◽  
Moustafa K. Soltan ◽  
Ahmed M. Said
Keyword(s):  
Molecular Modeling ◽  
Antitumor Activity ◽  
Cell Lines ◽  
Cancer Cell ◽  
Antiproliferative Activity ◽  
Antitumor Agents ◽  
Cancer Cell Lines ◽  
Normal Cells

Scaffolds hybridization is a well-known drug design strategy for antitumor agents. Herein, series of novel indolyl-pyrimidine hybrids were synthesized and evaluated in vitro and in vivo for their antitumor activity. The in vitro antiproliferative activity of all compounds was obtained against MCF-7, HepG2, and HCT-116 cancer cell lines, as well as against WI38 normal cells using the resazurin assay. Compounds 1–4 showed broad spectrum cytotoxic activity against all these cancer cell lines compared to normal cells. Compound 4g showed potent antiproliferative activity against these cell lines (IC50 = 5.1, 5.02, and 6.6 μM, respectively) comparable to the standard treatment (5-FU and erlotinib). In addition, the most promising group of compounds was further evaluated for their in vivo antitumor efficacy against EAC tumor bearing mice. Notably, compound 4g showed the most potent in vivo antitumor activity. The most active compounds were evaluated for their EGFR inhibitory (range 53–79 %) activity. Compound 4g was found to be the most active compound against EGFR (IC50 = 0.25 µM) showing equipotency as the reference treatment (erlotinib). Molecular modeling study was performed on compound 4g revealed a proper binding of this compound inside the EGFR active site comparable to erlotinib. The data suggest that compound 4g could be used as a potential anticancer agent.

Novel small-molecule CRM-1 inhibitor for GI cancer therapy.

2012 ◽  
Vol 30 (4_suppl) ◽  
pp. 245-245 ◽  
Author(s):  
Asfar S. Azmi ◽  
Michael Kauffman ◽  
Dilara McCauley ◽  
Sharon Shacham ◽  
Ramzi M Mohammad
Keyword(s):  
Cancer Cells ◽  
Cell Lines ◽  
Small Molecule ◽  
Nuclear Localization ◽  
Therapeutic Target ◽  
Nuclear Export ◽  
Single Agent ◽  
Nuclear Export Signal ◽  
Pharmacokinetic Parameters ◽  
Structure Based Drug Design

245 Background: Pancreatic (PC) and Colon (CC) cancer remain deadly diseases despite the advent of novel targeted and cytotoxic therapies. Therefore, identification of new targets and development of novel agents against these targets are urgently needed. CRM-1 is a nuclear export protein encoded by the XPO1 (exportin 1) gene that mediates leucine-rich nuclear export signal ( NES )-dependent protein export. Elevated CRM-1 expression has been correlated with poor prognosis in PC and CC making it an attractive therapeutic target. Methods: Using structure based drug design, we have identified novel, irreversible small molecule inhibitors of CRM-1 that lock target proteins, including TSP, in the nucleus. Normal cells undergo cell cycle arrest, but most cancer cells initiate apoptosis. Thus, the drugs selectively kill cancer cells with minimal toxicity to normal tissue and possess clinically acceptable pharmacokinetic parameters. In this report, using multiple molecular biological techniques, we have evaluated the role of CRM-1 inhibition on nuclear localization and apoptosis by PAR-4. Results: The most potent small molecule CRM-1 inhibitor (KPT-185) induced growth inhibition and apoptosis in a panel of PC and CC cell lines with IC50’s <150 nM. Western blot and confocal microscopy analyses demonstrated that KPT-185 treatment resulted in TSP and PAR-4 nuclear localization (a pre-requisite for PAR-4 mediated apoptosis). Most significantly, siRNA knockdown of PAR-4 abrogated the apoptotic potential of KPT-185 in BxPC-3 and Colo-357 (PC) and HCT-116 and HT-29 (CC) cell lines, confirming that this was indeed a PAR-4 dependent apoptotic mechanism. KPT-185 showed synergistically enhanced apoptosis when combined with oxaliplatin in all the tested cell lines. Human genomic expression microarray profiling using HT-12 arrays are underway. Additionally, animal xenograft studies involving single agent KPT-185 and combination with oxaliplatin are currently ongoing. Conclusions: This is the first report demonstrating CRM-1 as a potential therapeutic target in both PC and CC, perhaps by enhancing PAR-4 function. The drugs KPT-185 and related CRM1-inhibitors warrant further clinical investigations for this deadly malignancy.

A new small-molecule Aurora B inhibitor shows antitumor activity in human cancer cell lines

2014 ◽  
Vol 42 (2) ◽  
pp. 517-524 ◽  
Author(s):  
Yuanyuan Wu ◽  
Jie Li ◽  
Chenxiao Jiang ◽  
Xianmei Yang ◽  
Lihuan Cao ◽  
...  
Keyword(s):  
Antitumor Activity ◽  
Cell Lines ◽  
Cancer Cell ◽  
Small Molecule ◽  
Human Cancer ◽  
Cancer Cell Lines ◽  
Aurora B ◽  
Human Cancer Cell ◽  
Human Cancer Cell Lines

ASN003, a highly selective BRAF and PI3K inhibitor: Preclinical and phase 1 clinical data in patients with advanced solid tumors.

2017 ◽  
Vol 35 (15_suppl) ◽  
pp. e14102-e14102
Author(s):  
Drew W. Rasco ◽  
Ryan J. Sullivan ◽  
Nehal J. Lakhani ◽  
Sanjeeva Reddy ◽  
Niranjan Sathyanarayana Rao ◽  
...  
Keyword(s):  
Antitumor Activity ◽  
Solid Tumors ◽  
Cell Lines ◽  
Small Molecule ◽  
Antiproliferative Activity ◽  
Phase 1 ◽  
Advanced Solid Tumors ◽  
Pdx Model ◽  
Xenograft Models ◽  
Strong Antitumor Activity

e14102 Background: RAS-RAF-MEK and PI3K-AKT-mTOR are two major signaling pathways involved in tumorigenesis. Components of these two pathways are frequently mutated in a broad range of tumors. ASN003 is a novel and highly selective small-molecule inhibitor of the RAS-RAF-MEK and PI3K pathways. Methods: The activity of ASN003 was determined using PI3K and BRAF enzymes, and efficacy was studied in human tumor xenograft models in mice. ASN003 is currently being investigated in patients with solid tumors in a Phase 1 trial using an accelerated dose titration design. In Part A, safety and tolerability of ASN003 is being studied in patients with advanced solid tumors. In Part B, safety, tolerability and preliminary efficacy of ASN003 will be evaluated in melanoma, CRC and NSCLC patients with a BRAF, PIK3CA or PTEN mutation. Pharmacokinetic (PK) profile and the pharmacodynamic (PD) effects of ASN003 on biomarkers such as pERK and pS6 are investigated in both parts of the study. Results: ASN003 showed potent and highly selective inhibition of BRAF and PI3K-α and -δ, and low affinity for PI3K-ß. ASN003 showed strong antiproliferative activity in cell lines and caused significant tumor growth inhibition in xenograft models harboring BRAF and PIK3CA or PTEN mutations. ASN003 showed antiproliferative activity in B-RAF and MEK inhibitor resistant cell lines. ASN003 had a strong antitumor activity in a BRAFV600mutant melanoma PDX model resistant to BRAF inhibitors, vemurafenib and dabrafenib. In humans, to date, ASN003 was well tolerated at 10 and 20 mg QD. Adverse events were mild and peak plasma level of 120 nM at 10 mg QD was achieved with a half-life of > 12 h. Dose escalation is ongoing. Conclusions: ASN003 is a unique small molecule, with highly selective and potent inhibition of BRAF, PI3-α and -δ kinases. ASN003 has strong antitumor activity in various xenograft tumor models harboring both BRAF and PIK3CA/PTEN mutations, and in a BRAF inhibitor resistant melanoma PDX model. To date, ASN003 was well tolerated and achieved good systemic exposure. Updated and detailed clinical, PK and PD results will be presented. Clinical trial information: NCT02961283.

Prelinical evaluation of selective inhibitors of nuclear export (SINE) CRM1 (XPO1) inhibitors in prostate cancer (PrCa).

2012 ◽  
Vol 30 (15_suppl) ◽  
pp. e15200-e15200 ◽  
Author(s):  
Sharon Shacham ◽  
Giovanni Luca Gravina ◽  
Enrico Ricevuto ◽  
Andrea Mancini ◽  
Lynda Chin ◽  
...  
Keyword(s):  
Cell Lines ◽  
Nuclear Export ◽  
Single Agent ◽  
Genetic Alterations ◽  
Nuclear Accumulation ◽  
Nuclear Pore ◽  
Mrna Levels ◽  
Multiple Tumor ◽  
Selective Blockade ◽  
Androgen Independent

e15200 Background: CRM1 (XPO1) is the sole exportin mediating transport of multiple tumor suppressor proteins (TSP) including p53, pRB, FOXO, APC and NPM1 out of the nucleus, abrograting their function. Many tumor types show overexpression of CRM1, thus extinguishing TSP function. CRM1 inhibition forces nuclear accumulation of TSPs inducing apoptosis in cancer cells. Methods: MSKCC PrCa gene database was used for mRNA analyses. Inhibition of CRM1 mediated NE was determined by IHC. MTT assays were used to determine cytotoxicity across divergent PrCa lines: LAPC-4 (p53wt, AR+, low Akt/mTOR); LnCaP (p53wt, AR+, high Akt/mTOR); LnCaP-C81 and LnCaP-C4-2B (p53wt, AR+, androgen independent, high Akt/mTOR); 22rv1 (p53wt, AR+, androgen independent, low Akt/mTOR); PC3 (p53-del, AR–, high Akt/mTOR), DU145 (p53mut, AR–, low Akt/mTOR). BPH1 and prostatic epithelial line EPN were used as non-neoplastic controls. 22rv1 xenografts were initiated in the flanks of SCID mice and treatment begun when tumors reached ~150mm3. Results: Analyses of nuclear pore complex (NPC)-related mRNA levels shows coordinate regulation of transcripts and allow PrCa to be segregated into high and low NPC expression. Low NPC expressing tumors tended to have reduced AR expression; APC, NPM1, and RB1 mRNA levels were also low (p<10e-12) and p16INK4A levels were elevated. As NE is dysregulated in PrCa, we assessed the effects of SINE, irreversible CRM1 inhibitors, across PrCa cell lines. SINE block CRM1 mediated nuclear export of TSPs with IC50 values <100 nM in all tested cell lines. SINE are selectively cytotoxic for neoplastic (EC50 10-1000nM) versus non-neoplastic lines (EC 50 >5-20µM). SINE cytotoxic effects are independent all tested genetic alterations. In the aggressive, androgen independent 22rv1 xenograft, oral SINE KPT-251 showed dose-dependent inhibition of tumor growth and synergy with cisplatin. Conclusions: These data show that PrCa shows coordinate NPC regulation, and that selective blockade of CRM1 dependent NE represents a completely novel, neoplasia-selective and well-tolerated target for use as single agent or in combination with chemotherapy for PrCa.

Effects of SM08502, a novel, oral small-molecule inhibitor of Wnt pathway signaling, on gene expression and antitumor activity in colorectal cancer (CRC) models.

2019 ◽  
Vol 37 (15_suppl) ◽  
pp. e15185-e15185 ◽  
Author(s):  
Carine Bossard ◽  
Kevin Chiu ◽  
Heekyung Chung ◽  
John Duc Nguyen ◽  
Emily Creger ◽  
...  
Keyword(s):  
Gene Expression ◽  
Cell Proliferation ◽  
Antitumor Activity ◽  
Wnt Signaling ◽  
Cell Lines ◽  
Wnt Pathway ◽  
Pathway Gene ◽  
Hct 116

e15185 Background: Aberrant activation of Wnt signaling contributing to tumorigenesis is most commonly associated with CRC (90% harbor Wnt pathway mutations). SM08502, a novel, oral Wnt signaling pathway inhibitor, was evaluated in preclinical CRC models. Methods: In vitro Wnt signaling: assessed using TOPflash β-catenin/TCF reporter assay in SW480 human CRC cells. In vitro Wnt pathway gene expression: measured by qRT-PCR in SW480 and Wnt3a-stimulated cells (HEK-293T, IEC-6), and with the Nanostring Wnt pathway array (180 genes) across a panel of 16 CRC cell lines. In vitro cell proliferation: 17 CRC cell lines were used to test cell viability following treatment. In vivo antitumor activity: Oral SM08502 was tested in CRC mouse xenografts (SW480, HCT 116) and a PDX model over 20-21 days (QD, QOD). 24-hr pharmacodynamic (PD) analysis of Wnt pathway gene expression was done in SW480 tumor explants from mice following one 25 mg/kg dose. Results: SM08502 inhibited Wnt pathway signaling (EC50 = 46 nM) in SW480 cells. Wnt pathway gene expression was inhibited by SM08502 (0.3-3 µM) in Wnt3a-stimulated cells ( AXIN2, LEF1) and SW480 ( AXIN2, CTNNB1, LEF1, MYC, TCF7, TCF7L2) at 24 hrs ( P < .05 vs. vehicle) . Corresponding effects on protein expression were confirmed for all genes except CTNNB1, suggesting SM08502 acted independently of β-catenin. Nanostring array screening identified inhibition of LRP5, DVL2, BTRC, and ERBB2 by SM08502. Cell proliferation was inhibited in all 17 lines (avg. EC50 = 177 nM). In vivo, SM08502 was well tolerated and induced dose-dependent antitumor effects in xenografts and PDX models. Tumor growth inhibition for 25 mg/kg QD (max dose) was 83%, 56%, and 70% in SW480, HCT 116, and PDX, respectively. PD analysis showed significant inhibition ( P< .05 vs. vehicle) of TCF7, MYC, LRP5, DVL2, and BTRC expression 8 hrs post treatment. Conclusions: In preclinical CRC models, SM08502 was a potent inhibitor of Wnt pathway signaling and gene expression. It showed strong antitumor activity in human tumor models with activating Wnt pathway mutations. The safety, tolerability, and PK of SM08502 are being evaluated in an ongoing phase 1 study (NCT03355066).

scholarly journals Selinexor versus doxorubicin in dedifferentiated liposarcoma PDXs: evidence of greater activity and apoptotic response dependent on p53 nuclear accumulation and survivin down‐regulation

2021 ◽  
Vol 40 (1) ◽  
Author(s):  
Valentina Zuco ◽  
Sandro Pasquali ◽  
Monica Tortoreto ◽  
Silvia Brich ◽  
Stefano Percio ◽  
...  
Keyword(s):  
Antitumor Activity ◽  
Cell Lines ◽  
Nuclear Export ◽  
Treatment Strategies ◽  
Survivin Expression ◽  
Dedifferentiated Liposarcoma ◽  
Nuclear Accumulation ◽  
Apoptotic Response ◽  
Primary Cell Lines ◽  
Poor Outcomes

Abstract Background Dedifferentiated liposarcoma (DDLPS), a tumor that lacks effective treatment strategies and is associated with poor outcomes, expresses amplified MDM2 in the presence of wild-type p53. MDM2 ubiquitination of p53 facilitates its XPO1-mediated nuclear export, thus limiting p53 tumor suppressor functions. Consequently, nuclear export is a rational target in DDLPS. We directly compared the antitumor activity of the first-in class XPO1 inhibitor selinexor and doxorubicin, the standard front-line therapy in sarcomas, in DDLPS patient-derived xenografts (PDXs) and primary cell lines. Methods Drug activity was assessed in three PDXs (and two corresponding cell lines) established from the dedifferentiated component of primary untreated retroperitoneal DDLPS with myogenic (N = 2) and rhabdomyoblastic (N = 1) differentiation from patients who underwent surgery. These models were marked by amplification of MDM2, CDK4 and HMGA2 genes. Results Selinexor was moderately active in the three PDXs but achieved greater tumor response compared to doxorubicin (maximum tumor volume inhibition: 46–80 % vs. 37–60 %). The PDX harboring rhabdomyoblastic dedifferentiation showed the highest sensitivity to both agents. PDX response to selinexor and doxorubicin was not associated with the extent of MDM2 and CDK4 gene amplification. Interestingly, the most chemosensitive PDX model showed the lowest extent of HMGA2 amplification. Selinexor was also more efficient than doxorubicinin in inducing an apoptotic response in PDXs and cell lines. Consistently, an increased nuclear accumulation of p53 was seen in all selinexor-treated models. In addition, a time-dependent decrease of survivin expression, with an almost complete abrogation of the cytoplasmic anti-apoptotic pool of this protein, was observed as a consequence of the decreased acetylation/activation of STAT3 and the increased ubiquitination of nuclear survivin. Conclusions Selinexor showed a moderate antitumor activity in three DDLPS PDXs, which was, however, consistently higher than doxorubicin across all different models regardless the extent of MDM2 amplification and the histological differentiation. The depletion of survivin protein seems to significantly contribute to the induction of apoptosis through which selinexor exerts its antitumor activity.

KPT-SINE, a Potent, Small Molecule Inhibitor of CRM1-Dependent Nuclear-Cytoplasmic Shuttling, with Potent Activity Against T-ALL and AML

Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 2622-2622 ◽  
Author(s):  
Julia Etchin ◽  
Alex Kentsis ◽  
Takaomi Sanda ◽  
Andrew L. Kung ◽  
Richard M. Stone ◽  
...  
Keyword(s):  
Progenitor Cells ◽  
Cell Lines ◽  
Small Molecule ◽  
Nuclear Export ◽  
Cellular Proliferation ◽  
Covalent Modification ◽  
Binding Interface ◽  
Equity Ownership ◽  
Cargo Binding

Abstract Abstract 2622 Background: CRM1 (XPO1) is the major nuclear exporter that mediates transport of a variety of cargos, including proteins involved in tumor suppressor and cellular proliferation pathways (e.g. p53, PI3K/AKT, and NF-kB). CRM1 is upregulated in a range of solid and hematologic malignancies and its overexpression is correlated with poor prognosis, and with resistance to chemotherapy. Recently, the crystal structure of CRM1, in complex with its export cargo, Snurportin 1, has been resolved. The structure elucidates the key contact residues required for the formation of the CRM1-cargo export complex. The molecular understanding of the CRM1-cargo binding interface has led to the development of novel small molecule inhibitors of CRM1-cargo interaction, termed KPT-Selective Inhibitors of Nuclear Export (SINE). KPT-SINE are potent, drug-like CRM1 inhibitors that irreversibly inactivate the CRM1-directed protein export by covalent modification of the essential CRM1-cargo binding residue Cys528. The inhibition of the CRM1 nuclear export has been shown to lead to selective apoptosis in cancer cells when compared to normal cells. Here, we assess the efficacy of the KPT-SINE in human T-ALL, AML, and normal hematopoietic cells. Methods: The viability of a panel of human T-ALL and AML cell lines and normal CD34+ progenitor cells upon treatment by the KPT-SINE was assessed. Dose-response measurements were done using serial dilutions of KPT-SINE from 1 μM to 0.3 nM and luminescent cell viability assay. Apoptosis was measured using Annexin V staining and TUNEL assays. Results: KPT-SINE induces rapid apoptosis in 12 of 15 T-ALL and 10 of 14 AML cell lines with 50% inhibitory concentrations (IC50s) of 15–100 nM. In the KPT-SINE-sensitive cell lines, BCL2 overexpression suppresses KPT-SINE-induced apoptosis, indicating its intrinsic pathway mediation. Importantly, KPT-SINE exhibits selective cytotoxicity against tumor cells when compared to peripheral blood mononuclear cells (PBMCs) and CD34+ progenitor cells in vitro. KPT-SINE at 57 and 150 mg/kg induced 100% inhibition of tumor growth in vivo in a MOLT-4 T-ALL xenograft study. Other xenograft studies to address the potency of the KPT-SINE on selected AML lines in vivo are ongoing. These studies emphasize the clinical promise of the KPT-SINE as a novel and selective drug candidate for the treatment of T-ALL and AML. Disclosures: McCauley: Karyopharm Therapeutics: Employment. Kauffman:Karyopharm: Equity Ownership. Shacham:Karyopharm: Equity Ownership.

Sign in / Sign up

Export Citation Format

Share Document