Aurora Kinases As AntiCancer Targets

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Aurora Kinases As Anti-Cancer Targets

• Kian-Huat Lim
• 10/09/2009

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Aurora kinases

• serine/threonine kinases that regulate mitosis
• Auroras-A and B
• expressed in many different cell type
• conserved from C. elegans to mammals
• essential in mitotic progression
• overexpressed in many cancers
• Aurora-C
• found in mammals only
• restricted to testicular tissue, required for
  late spermiogenesis
• KO mice viable, infertile
• role in cancer is unclear

Glover et al. Cell. 1995 Apr 781(1)95-105 Keen
et al. Nat Rev Cancer. 2004 Dec4(12)927-36 Marum
oto et al. Nat Rev Cancer. 2005 Jan5(1)42-50
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Structure of Aurora Kinases
Marumoto et al. Nat Rev Cancer. 2005
Jan5(1)42-50
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Mitosis
Kops et al. Nat Rev Cancer. 2005 Oct5(10)773-85
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Localization and Function of Aurora-A (red)
Centrosome maturation separation Mitotic entry
Bipolar spindle assembly
Degraded by APC
Abnormal spindle assembly
Chromosome misalignment
Tetraploid cells Apoptosis
Incorrect centriole Separation G2/M arrest
Keen et al. Nat Rev Cancer. 2004
Dec4(12)927-36 Sasai et al. Oncogene. 2008 Jul
327(29)4122-7 Lu et al. J Biol Chem. 2008 Nov
14283(46)31785-90 Cowley et al Mol Cell Biol.
2009 Feb29(4)1059-71
KO mice embryonically lethal
at blastocyst stage
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Localization and Function of Aurora-B (green)
Chromosome condensation Centromere maturation
Proper orientation of chromosomes attachment to
the mitotic spindle If messed up, initiates
spindle checkpoint
Cytokinesis
Defective chromosome-spindle formation Loss of
spindle checkpoint
Polyploidy/aneuploidy Apoptosis
KO mice not reported yet
Keen et al. Nat Rev Cancer. 2004 Dec4(12)927-36
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Substrates of Aurora-A and B
Gautschi et al. Clin Cancer Res. 2008 Mar
1514(6)1639-48
Gautschi O et al. Clin Cancer Res
2008141639-1648
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Aurora-A and Cancers

• Aurora-A is frequently overexpressed in various
  cancers
• By gene amplification (chromosome 20q13),
  polymorphisms, transcriptional or translational
  upregulation, protein stabilization
• colon (50), pancreatic (58), breast (BTAK),
  HCC, bladder, ovarian, gastric, head and neck
• associated with higher grade histology and poorer
  prognosis
• Aurora-A overexpression confers chemoresistance
  to taxanes/vinca alkaloids by overriding spindle
  checkpoint

Kops et al. Nat Rev Cancer. 2005
Oct5(10)773-85 Ying et al. Oncogene (2003) 22,
82938301
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Oncogenic mechanisms of Aurora-A

• Chromosomal instability
• Overexpression overrides spindle checkpoint,
  leads to cytokinesis failure and
  aneuploidy/polyploidy
• Requires loss of p53 or gain of Bcl-xL/Bcl-2 for
  cellular transformation
• Oncogene ?
• Directly transforms rat fibroblasts and NIH 3T3
  cells
• Potentiates Ras-induced transformation of murine
  fibroblasts
• Mechanism and substrate unclear

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Aurora-B and Cancers

• Aurora-B is frequently overexpressed in various
  cancers
• Transcriptional or translational upregulation,
  polymorphism
• NSCLC (78), GBM (32), oral SCC, prostate,
  endometrial, thyroid
• associated with poor differentiation, lymph node
  involvement, metastatic potential and a shortened
  survival

NSCLC
Boss et al. Oncologist. 2009 Aug14(8)780-93 Smit
h et al. BJC (2005) 93(6), 719 729
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Oncogenic mechanism of Aurora-B

• Chromosomal instability
• Overexpression leads to multinuclearity and
  aneuploidy
• Not transforming

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Aurora kinase inhibitors
Boss et al. Oncologist. 2009 Aug14(8)780-93
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Boss et al. Oncologist. 2009 Aug14(8)780-93
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Xenograft in nude mice
Colony forming
HL-60 (AML)
HCT-116
AML
Harrington et al. Nat Med. 2004 Mar10(3)262-7
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VX-680 (Tozasertib, Merck)

• Pan-aurora kinase inhibitor
• Phase I, Rubin et al (J Clin Oncol
  200624Abstract 3009)
• 16 patients with advanced solid malignancies
• 8 mg/m2/hour, cont. 5-day IV infusion, q28 days
• 3/16 treated patients achieved stable disease (2
  completed 6 cycles)
• Phase I, Papayannidis et al (J Clin Oncol
  200927Abstract 7080)
• 3 patients w/ Phil ALL or CML, failed imatinib
• achieved hematologic CR tozasertib
• Report (Giles et al, Blood. 2007 Jan
  15109(2)500-2)
• 3 patients with T315I BCR-ABL (2CML, 1ALL)
• All achieved CR

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• PHA-739358 (Danusertib,Neviano)
• Pan-aurora kinase inhibitor
• 50 patients with advanced solid malignancy
• DLT neutropenia, diarrhea
• 330mg/m2 infused over 6 hours on days 1, 8, and
  15 in a 28-day cycle
• No PR or CR, 20 achieved SD at 6 months

Steeghs et al J Clin Oncol. 2009 Sep 21
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PHA-739358 (Danusertib, Nerviano)
Pt demographics
Toxicities
Steeghs et al J Clin Oncol. 2009 Sep 21
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MLN 8237, Millennium

• Aurora-A inhibitor, oral form
• Phase I, Infante et al (European Journal of
  Cancer Supplements 20086(12) Abstract 280)
• 23 patients w/ advanced solid tumors
• Up to 150mg/day once daily, D1-D7 q21 days
• 6 patients at highest dose, 3/6 patients
  developed neutropenia,grade 3 mucositis, and
  grade 3 somnolence
• 1 ovarian cancer with PR, 4 SD
• Phase I, Cervantes-Ruiperez et al (J Clin Oncol
  200927 Abstract 2565)
• 27 patients w/ advanced solid tumors
• QD or BID for 7 days, off 14 days
• DLT stomatitis and neutropenia
• 1 patient with liposarcoma with PR

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Trials at BJH MLN8237
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AZD1152 (AstraZeneca)

• Aurora-B inhibitor
• Preclinical studies colon, NSCLC, AML and MM
• Phase 1, Schellens et al (J Clin Oncol 200624(18
  suppl) Abstract 3008)
• 13 patients, advanced solid malignancies
  (melanoma, CRC)
• Up to 300mg infusion over 2hours,qweek
• DLT neutropenia
• 5/13 patients achieved SD over 12 wks

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Theoretical concerns

• Too late
• If aneuplody and polyploidy are the main
  oncogenic mechanisms, inhibiting aurora kinases
  should not work
• Cytostatic in most studies
• Cross-inhibition of other kinases
• Potentially carcinogenic??
• Aurora-A heterozygosity results in a
  significantly increased tumor incidence in mice

Lu et al. J Biol Chem. 2008 Nov
14283(46)31785-90
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Synergism with other agents in preclinical studies

• Aurora-A
• docetaxel in ovarian cancer (Lin et al. Clin
  Cancer Res. 2008 Sep 114(17)5437-46)
• paclitaxel and docetaxel in pancreatic cancer
  (Hata el al. Cancer Res 2005652899 2905)
• vincristine in colon cancer (Lentini et al. Oncol
  Res. 200817(3)115-25. )
• rituximab in B-cell NHL (Zhang et al. J Clin
  Oncol 200927Abstract 8553)
• Aurora-B
• irinotecan, docetaxel, vinorelbine, gemcitabine,
  oxaliplatin, 5-FU vincristine and etopiside (Nair
  et al. J Clin Oncol 200422Abstract 9568 Yang
  et al. Blood 20071102034 2040)
• radiotherapy (Tao et al. Oncogene 2008273244
  3255)

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Summary

• Aurora-A and B are frequently overexpressed in
  human cancers, and are associated with poor
  prognosis
• Overexpression of aurora-A may confer resistance
  to anti-microtubule agents
• Inhibition of aurora kinases lead to mitotic
  arrest and apoptosis
• Aurora kinase inhibitors are mostly cytostatic
• Combined use with other agents is likely to be
  more effective
• DLTs are hematologic and GI
• Long-term side effect is unclear (secondary
  malignancy?)

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Thank you
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Aurora-A is overexpressed in KRas-mutated
pancreatic cancer cells
RalA is the key Ras effectorin pancreatic cancer
Lim et al MCB accepted Lim et al. Cancer Cell.
2005 Jun7(6)533-45
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Aurora-A potentiates Ras-induced transformation
of human epithelial cells
Increased malignant growth occurred within
days All cells are diploid
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Aurora-A phosphorylates, activates
andrelocalizes Ras effector, RalA
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Phosphorylation of RalA at S194 by Aurora-A is
required for malignant phenotype
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Synergistic Effect of Ras and Aurora-A converges
on RalA
RasG12V
RalA
P
active
RalA
Cancer!
RalA
GTP
inactive
active
GTP
GDP
GTP
Aurora-A