ACS Medicinal Chemistry Letters
Letter
growth of colorectal cancer cell lines SW480 and HCT116 that
have hyperactivated Wnt signaling. Compound 11 inhibited
growth of Wnt-activated cancer cells with the IC50 values of 22
REFERENCES
■
(1) Clevers, H.; Loh, K. M.; Nusse, R. Stem cell signaling. An integral
program for tissue renewal and regeneration: Wnt signaling and stem
cell control. Science 2014, 346, 1248012.
4.0 and 26
6.6 μM for SW480 and HCT116 cells,
respectively (Figure 4C). Compounds 11 and 13 exhibited
>10-fold selectivity for Wnt signaling-activated cancer cells over
Wnt signaling-latent cancer cells, such as lung adenocarcinoma
A549 cells. These two compounds also exhibited 3−4-fold
selectivity for Wnt signaling-activated cancer cells over HEK293
cells.
(2) Zeng, X.; Huang, H.; Tamai, K.; Zhang, X.; Harada, Y.; Yokota,
C.; Almeida, K.; Wang, J.; Doble, B.; Woodgett, J.; Wynshaw-Boris, A.;
Hsieh, J.-C.; He, X. Initiation of Wnt signaling: control of Wnt
coreceptor Lrp6 phosphorylation/activation via frizzled, dishevelled
and axin functions. Development 2008, 135, 367−375.
(3) Mosimann, C.; Hausmann, G.; Basler, K. β-Catenin hits
chromatin: regulation of Wnt target gene activation. Nat. Rev. Mol.
Cell Biol. 2009, 10, 276−286.
The β-catenin/BCL9 PPI, a key downstream effector of
canonical Wnt signaling, represents an appealing therapeutic
target for treatment of cancer and fibrosis and eradication of
cancer stem cells. In this study, the critical binding elements at
the BCL9 binding site for hydrophobic, H-bond, and charge−
charge interactions were extracted from the crystal structure of
the β-catenin/BCL9 PPI (PDB ids, 2GL727 and 3SL930). A
small-molecule inhibitor with a novel scaffold was designed to
match the proposed critical binding elements. A further
structural optimization resulted in 11 and 13. Compound 11
exhibited a Ki value of 5.2 0.74 μM for disruption of the β-
catenin/BCL9 PPI and 98-fold selectivity for β-catenin/BCL9
over β-catenin/cadherin PPIs. The SARs and site-directed
mutagenesis results are in agreement with the proposed binding
mode of this series of inhibitors. The cell-based studies
demonstrated that 11 and 13 can suppress transactivation of
canonical Wnt signaling and inhibit growth of cancer cells with
hyperactivated Wnt signaling. Compound 11 is similar to 1
from our previous study34 in that both are designed to form salt
bridges with E155 and D145 of β-catenin, and both have
hydrophobic moieties intended to interact with the hydro-
phobic pockets of β-catenin near L156 and L159 (Figure 1A).
However, compared to 1, compound 11 is more hydrophilic
giving it better drug-like properties. In addition, the piperazine
moiety in the middle of the molecule can be functionalized,
allowing future optimizations to access more chemical space.
(4) Clevers, H.; Nusse, R. Wnt/β-catenin signaling and disease. Cell
2012, 149, 1192−1205.
(5) Anastas, J. N.; Moon, R. T. WNT signalling pathways as
therapeutic targets in cancer. Nat. Rev. Cancer 2013, 13, 11−26.
(6) Singh, S. K.; Hawkins, C.; Clarke, I. D.; Squire, J. A.; Bayani, J.;
Hide, T.; Henkelman, R. M.; Cusimano, M. D.; Dirks, P. B.
Identification of human brain tumour initiating cells. Nature 2004,
432, 396−401.
(7) O’Brien, C. A.; Pollett, A.; Gallinger, S.; Dick, J. E. A human
colon cancer cell capable of initiating tumour growth in
immunodeficient mice. Nature 2007, 445, 106−110.
(8) Ricci-Vitiani, L.; Lombardi, D. G.; Pilozzi, E.; Biffoni, M.; Todaro,
M.; Peschle, C.; De Maria, R. Identification and expansion of human
colon-cancer-initiating cells. Nature 2007, 445, 111−115.
(9) Malanchi, I.; Peinado, H.; Kassen, D.; Hussenet, T.; Metzger, D.;
Chambon, P.; Huber, M.; Hohl, D.; Cano, A.; Birchmeier, W.;
Huelsken, J. Cutaneous cancer stem cell maintenance is dependent on
β-catenin signalling. Nature 2008, 452, 650−653.
(10) Yeung, J.; Esposito, M. T.; Gandillet, A.; Zeisig, B. B.;
Griessinger, E.; Bonnet, D.; So, C. W. E. β-Catenin mediates the
establishment and drug resistance of MLL leukemic stem cells. Cancer
Cell 2010, 18, 606−618.
(11) Chen, B.; Dodge, M. E.; Tang, W.; Lu, J.; Ma, Z.; Fan, C.-W.;
Wei, S.; Hao, W.; Kilgore, J.; Williams, N. S.; Roth, M. G.; Amatruda, J.
F.; Chen, C.; Lum, L. Small molecule-mediated disruption of Wnt-
dependent signaling in tissue regeneration and cancer. Nat. Chem. Biol.
2009, 5, 100−107.
(12) Wang, X.; Moon, J.; Dodge, M. E.; Pan, X.; Zhang, L.; Hanson,
J. M.; Tuladhar, R.; Ma, Z.; Shi, H.; Williams, N. S.; Amatruda, J. F.;
Carroll, T. J.; Lum, L.; Chen, C. The development of highly potent
inhibitors for porcupine. J. Med. Chem. 2013, 56, 2700−2704.
(13) Liu, J.; Pan, S.; Hsieh, M. H.; Ng, N.; Sun, F.; Wang, T.;
Kasibhatla, S.; Schuller, A. G.; Li, A. G.; Cheng, D.; Li, J.; Tompkins,
C.; Pferdekamper, A.; Steffy, A.; Cheng, J.; Kowal, C.; Phung, V.; Guo,
G.; Wang, Y.; Graham, M. P.; Flynn, S.; Brenner, J. C.; Li, C.;
Villarroel, M. C.; Schultz, P. G.; Wu, X.; McNamara, P.; Sellers, W. R.;
Petruzzelli, L.; Boral, A. L.; Seidel, H. M.; McLaughlin, M. E.; Che, J.;
Carey, T. E.; Vanasse, G.; Harris, J. L. Targeting Wnt-driven cancer
through the inhibition of Porcupine by LGK974. Proc. Natl. Acad. Sci.
U. S. A. 2013, 110, 20224−20229.
(14) Huang, S.-M.; Mishina, Y. M.; Liu, S.; Cheung, A.; Stegmeier, F.;
Michaud, G. A.; Charlat, O.; Wiellette, E.; Zhang, Y.; Wiessner, S.;
Hild, M.; Shi, X.; Wilson, C. J.; Mickanin, C.; Myer, V.; Fazal, A.;
Tomlinson, R.; Serluca, F.; Shao, W.; Cheng, H.; Shultz, M.; Rau, C.;
Schirle, M.; Schlegl, J.; Ghidelli, S.; Fawell, S.; Lu, C.; Curtis, D.;
Kirschner, M. W.; Lengauer, C.; Finan, P. M.; Tallarico, J. A.;
Bouwmeester, T.; Porter, J. A.; Bauer, A.; Cong, F. Tankyrase
inhibition stabilizes axin and antagonizes Wnt signalling. Nature 2009,
461, 614−620.
ASSOCIATED CONTENT
■
S
* Supporting Information
The Supporting Information is available free of charge on the
Figures S1−S8, Schemes S1−S5, experimental details,
HPLC conditions, HPLC tracers, and NMR spectra for
AUTHOR INFORMATION
■
Corresponding Author
*Phone: (801) 581-6747. Fax: (801) 581-8433. E-mail:
Funding
This work was supported by the Department of Defense
CDMRP BCRP breakthrough award W81XWH-14-1-0083 (to
H.J).
Notes
(15) Dancey, J. E.; Bedard, P. L.; Onetto, N.; Hudson, T. J. The
genetic basis for cancer treatment decisions. Cell 2012, 148, 409−420.
(16) Emami, K. H.; Nguyen, C.; Ma, H.; Kim, D. H.; Jeong, K. W.;
Eguchi, M.; Moon, R. T.; Teo, J.-L.; Kim, H. Y.; Moon, S. H.; Ha, J. R.;
Kahn, M. A small molecule inhibitor of β-catenin/CREB-binding
protein transcription. Proc. Natl. Acad. Sci. U. S. A. 2004, 101, 12682−
12687.
The authors declare no competing financial interest.
ACKNOWLEDGMENTS
■
We thank the Center for High-Performance Computing at the
University of Utah for computer time.
E
ACS Med. Chem. Lett. XXXX, XXX, XXX−XXX