A Systems Analysis of Mitotic Apparatus Inhibitors Defines a Response Network for Breast Cancer

Deregulation of aspects of the mitotic apparatus leads to increased genome instability, carcinogenesis and aggressive tumor behavior in human and rodent model systems1. This knowledge has stimulated development of inhibitors of elements of the mitotic apparatus as anticancer agents including PLK1, CENPE, and AURKB and several are now being tested for efficacy clincially2-6. These trials and eventual clinical use will benefit from molecular markers that predict response. In order to identify such markers, we assessed quantitative responses to the agents GSK461364, GSK923295 and GSK1070916 that target PLK1, CENPE and AURKB; respectively, in a panel of 50 breast cancer cell lines. This analysis showed that basal subtype cell lines were preferentially sensitive to all three agents and that responses among the lines to the three agents were strongly correlated. This may be explained by our discovery that components of the mitotic apparatus including PLK1, CENPE and AURKB form a transcriptionally co-regulated network comprised of more than 50 genes that is preferentially active in basal subtype of breast cell lines and primary tumors. Remarkably, this network also is activate in subsets of cancers of the lung, ovarian, prostate and brain, Wilms tumor, human blood malignancies and selected normal tissues. We then defined a mitotic apparatus network index (MANI) and showed that high MANI was associated with poor outcome clinically and with preferential responsive to GSK461364, GSK923295 and GSK1070916 in preclinical models. This suggests that measures of the MANI will identify poor outcome tumors that will likely respond well to mitotic apparatus network gene inhibitors as well as potential dose limiting normal tissues.Reference1. Quigley, D.A. et al. Nature 458, 505-8 (2009).2. Strebhardt, K. & Ullrich, A. Nat. Rev. Cancer 6, 321-330 (2006).3. Toyoshima-Morimoto, F., Taniguchi, E., Shinya, N., Iwamatsu, A. & Nishida, E. Nature 410, 215-20 (2001).4. Barr, F.A., Sillje, H.H. & Nigg, E.A. Nat. Rev. Mol. Cell. Biol. 5, 429–440 (2004).5. McInnes, C. et al. Nat. Chem. Biol. 2, 608–617 (2006).6. Yamada, S. et al. Oncogene 23, 5901-5911(2004).

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 2020.

Pegylated interferon alpha-2B (PEG-Intron) for metastatic renal cell cancer (mRCC): Results of a phase II clinical trial and biologic correlates of response

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Background: PEG-Intron (PEG-I) is a pegylated derivative of interferon alpha-2b (IFN), recombinant, with a single molecule of mono methoxy polyethylene glycol which increases serum half-life. Methods: A single arm, one-stage phase II trial was conducted between 6/02 and 6/04 in 32 previously untreated patients (pts) with mRCC to assess time to progression and biologic correlates (primary and secondary endpoints). Eligibility included measurable disease and fresh tumor procured at surgery for genetic and immunohistochemical (vascular endothelial growth factor [VEGF] and carbonic anhydrase IX [CAIX]) studies. PEG-I was given SC at a weekly dose of 4.5 μg/kg until progression or intolerability. Quality of life (QOL) was assessed using the FACT-BRM. Results: All 32 were evaluable, 91% had prior nephrectomy, and MSKCC risk group (JCO 20:289–96, 2002) was: 41% good, 53% intermediate, 6% poor. 10 pts (31%; 95% CI: 16%-50%) achieved a partial response (PR). Median time to progression was 5.0 mos (95% C.I. [3, 7]); median survival was 31 mos (95% C.I. [18, not reached]). There were no grade IV toxicities; primary grade III toxicities were hematologic (6/32 pts; 19%) and fatigue (4/32 pts; 13%). FACT-BRM scores showed an initial decrease in QOL at 2 weeks followed by partial recovery. Genomic profiling of tumor samples identified four novel genes that correlated with IFN resistance: ABCD3, Hs.76704, Hs.11325, and Hs.94122. Change in serum VEGF levels did not correlate with response. Tumor tissue samples are being immunohistochemically stained for CAIX. Conclusions: PEG-I treatment results in a 31% response rate and similar median time to progression as standard IFN (JCO 18:2972–80, 2000) in this population with predominantly good and intermediate risk pts. Once weekly dosing was generally well tolerated. Future investigation of PEG-I in combination with novel targeted agents in mRCC is warranted. Further study of the four identified genes may provide insight into IFN resistance. Supported by Schering-Plough, Inc.

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