Late stage assay provider results from the probe development effort to identify MCL1-BIM inhibitors: Fluorescence polarization-based biochemical dose response assay for inhibitors of myeloid cell leukemia sequence 1 (MCL1) interactions with BIM-BH3 peptide
Name: Late stage assay provider results from the probe development effort to identify MCL1-BIM inhibitors: Fluorescence polarization-based biochemical dose response assay for inhibitors of myeloid cell leukemia sequence 1 (MCL1) interactions with BIM-BH3 peptide. ..more
BioActive Compounds: 6
Source (MLPCN Center Name): The Scripps Research Institute Molecular Screening Center
Affiliation: The Scripps Research Institute, TSRI
Assay Provider: Michael Cardone, Eutropics
Network: Molecular Library Probe Production Centers Network (MLPCN)
Grant Proposal Number: 1 R43 CA135915-01 Fast Track
Grant Proposal PI: Michael Cardone, Eutropics
External Assay ID: MCL1BIM_INH_FP_96_3XIC50 MDRUN assay provider Round 0
Name: Late stage assay provider results from the probe development effort to identify MCL1-BIM inhibitors: Fluorescence polarization-based biochemical dose response assay for inhibitors of myeloid cell leukemia sequence 1 (MCL1) interactions with BIM-BH3 peptide.
Cancer initialization and survival depends upon evasion of the programmed cell death (apoptosis) machinery that normally kills an unneeded or rogue cell (1). Although an effective mechanism for anti-cancer chemotherapeutics is apoptosis induction, cancer cells develop resistance to the pro-apoptotic proteins activated by these drugs (2). Multiple myeloma (MM) and chronic lymphoblastic leukemia (CLL) are two well-characterized lymphoid cancers (3). BCL-2 is an oncoprotein activated in these lymphomas, and serves to inhibit apoptosis induced by many cytotoxic compounds. Members of the BCL-2 protein family are regulated by protein-protein interactions, forming homo- and heterodimers (4, 5). One of these proteins, MCL1, is essential for survival of human MM cells (6). MCL1 and other BCL-2 proteins such as BCL-XL share BCL-2's ability to oppose apoptosis, as well as sequence homology in 4 a-helical BCL-2 homology (BH) regions, BH1-BH4 (3). As a result, these proteins are promising targets for studies on tumor initiation, progression and apoptosis resistance. Research showing that MCL1 opposes cell death (7), is highly expressed in hematopoetic stem cells and is regulated by growth factors (8), and that inhibiting BCL-2 protein-protein interactions via the crucial BH3 domain is a valid approach to cancer drug development (2, 9, 10), suggest that targeted therapies for MCL1 are needed. The identification of selective inhibitors of MCL1 will provide useful tools for the study of lymphoid tumorigenesis, and elucidate mechanisms for apoptosis induction in resistant cancers.
1. McConkey, DJ and Zhu, K, Mechanisms of proteasome inhibitor action and resistance in cancer. Drug Resist Updat, 2008. 11(4-5): p. 164-79.
2. Reed, JC, Drug insight: cancer therapy strategies based on restoration of endogenous cell death mechanisms. Nat Clin Pract Oncol, 2006. 3(7): p. 388-98.
3. Cory, S and Adams, JM, Killing cancer cells by flipping the Bcl-2/Bax switch. Cancer Cell, 2005. 8(1): p. 5-6.
4. Petros, AM, Olejniczak, ET and Fesik, SW, Structural biology of the Bcl-2 family of proteins. Biochim Biophys Acta, 2004. 1644(2-3): p. 83-94.
5. Redzepovic, J, Weinmann, G, Ott, I and Gust, R, Current trends in multiple myeloma management. J Int Med Res, 2008. 36(3): p. 371-86.
6. Derenne, S, Monia, B, Dean, NM, Taylor, JK, Rapp, MJ, Harousseau, JL, Bataille, R and Amiot, M, Antisense strategy shows that MCL1 rather than Bcl-2 or Bcl-x(L) is an essential survival protein of human myeloma cells. Blood, 2002. 100(1): p. 194-9.
7. Kozopas, KM, Yang, T, Buchan, HL, Zhou, P and Craig, RW, MCL1, a gene expressed in programmed myeloid cell differentiation, has sequence similarity to BCL2. Proc Natl Acad Sci U S A, 1993. 90(8): p. 3516-20.
8. Opferman, JT, Iwasaki, H, Ong, CC, Suh, H, Mizuno, S, Akashi, K and Korsmeyer, SJ, Obligate role of anti-apoptotic MCL-1 in the survival of hematopoietic stem cells. Science, 2005. 307(5712): p. 1101-4.
9. Letai, A, Pharmacological manipulation of Bcl-2 family members to control cell death. J Clin Invest, 2005. 115(10): p. 2648-55.
10. Oltersdorf, T, Elmore, SW, Shoemaker, AR, Armstrong, RC, Augeri, DJ, Belli, BA, Bruncko, M, Deckwerth, TL, Dinges, J, Hajduk, PJ, Joseph, MK, Kitada, S, Korsmeyer, SJ, Kunzer, AR, Letai, A, Li, C, Mitten, MJ, Nettesheim, DG, Ng, S, Nimmer, PM, O'Connor, JM, Oleksijew, A, Petros, AM, Reed, JC, Shen, W, Tahir, SK, Thompson, CB, Tomaselli, KJ, Wang, B, Wendt, MD, Zhang, H, Fesik, SW and Rosenberg, SH, An inhibitor of Bcl-2 family proteins induces regression of solid tumours. Nature, 2005. 435(7042): p. 677-81.
late stage, assay provider, powders, purchased, SAR, myeloma cell leukemia sequence 1, MCL, MCL1, MCL-1, Mcl1, cancer, anti-apoptotic protein, chronic lymphocytic leukemia, multiple myeloma, lymphoma, inhibitor, inhibition, dose response, low throughput, Scripps Florida, The Scripps Research Institute Molecular Screening Center, SRIMSC, Molecular Libraries Probe Production Centers Network, MLPCN.
The purpose of this assay is to determine dose response curves for powder samples of compounds identified as possible MCL1 inhibitor probe candidates. This biochemical assay monitors binding of the BH3 domain of the BCL-2 family member, Bim, to the binding pocket of human MCL1. In this fluorescence polarization (FP)-based assay, GST-MCL1 fusion protein is incubated with FITC-BH3-Bim peptides, in the presence of test compounds. Binding of peptide to MCL1 target protein increases the effective molecular mass of the peptide, slowing its rotation and increasing millipolarization (mP) units in the well. As designed, compounds that inhibit MCL1 will prevent binding of Bim peptide to MCL1, and increase the proportion of free to bound peptides, thereby reducing mP in the well. Compounds are tested by the assay provider in triplicate in a dilution series.
Contact the assay provider for specific details regarding how the assay was performed in their laboratory. The assay description from the HTS campaign is provided here: Prior to the start of the assay, 2.5 uL of Assay Buffer (Dulbecco's PBS pH 7.2, Brij 35 0.001%) containing 9.2 nM GST-MCL1 were dispensed into a 1536 microtiter plate. Next, 55 nL of test compound in DMSO, unlabeled Bim-BH3 control peptide (0.770 uM final concentration), or DMSO alone (0.45% final concentration) were added to the appropriate wells.
The assay was started by dispensing 2.5 uL of 8.0 nM FITC-BH3-Bim peptide in assay buffer (Dulbecco's PBS pH 7.2, Brij 35 0.001%) into all wells. Plates were centrifuged and after 20 minutes of incubation at 25 C, fluorescence polarization was read on a Viewlux microplate reader (PerkinElmer, Turku, Finland) using a FITC FP filter set and a FITC dichroic mirror (excitation = 525 nm, emission = 595 nm). Fluorescence polarization was read for 30 seconds for each polarization plane (parallel and perpendicular). The well fluorescence polarization value (mP) was obtained via the PerkinElmer Viewlux software.
The percent inhibition for each compound was calculated as follows:
Percent inhibition = ( Test_Compound_mP - median_Negative_Control_mP ) / ( median_ Positive_Control_mP - median_ Negative_Control_mP ) * 100
Test_Compound is defined as wells containing test compound.
Negative_Control is defined as wells containing DMSO.
Positive_Control is defined as wells containing unlabeled Bim-BH3 peptide.
For each test compound, percent inhibition was plotted against compound concentration. Contact the assay provider for details.
PubChem Activity Outcome and Score:
Compounds with an IC50 greater than 10 uM were considered inactive. Compounds with an IC50 equal to or less than 10 uM were considered active.
Activity score was then ranked by the potency, with the most potent compounds assigned the highest activity scores.
The PubChem Activity Score range for active compounds is 100-96, and for inactive compounds 95-0.
List of Reagents:
GST-MCL-1 enzyme (supplied by Assay Provider)
FITC-BH3-Bim peptide (supplied by Assay Provider)
Unlabeled BH3-Bim peptide (supplied by Assay Provider)
Dulbecco's PBS (Sigma-Aldrich, part D8537)
Brij 35 (Sigma-Aldrich, part B4184)
This assay was performed by the assay provider. Replicate values and raw data were not provided. This assay may have been run as two or more separate campaigns, each campaign testing a unique set of compounds. Possible artifacts of this assay can include, but are not limited to: dust or lint and compounds that modulate fluorescence. All test compound concentrations reported above and below are nominal; the specific test concentration(s) for a particular compound may vary based upon the actual sample provided.
* Activity Concentration.
Data Table (Concise)