Supplementary Figure 1 from Characterization of an Akt Kinase Inhibitor with Potent Pharmacodynamic and Antitumor Activity

Supplementary Figure 2 from Characterization of an Akt Kinase Inhibitor with Potent Pharmacodynamic and Antitumor Activity

Supplementary Methods and Figure Legends 1-2 from Characterization of an Akt Kinase Inhibitor with Potent Pharmacodynamic and Antitumor Activity

2,3,5-Trisubstituted pyridines have been designed as potent AKT inhibitors that are selective against ROCK1 based on the comparison between AKT and ROCK1 structures. Substitution at the 2-position of the core pyridine is the key element to provide selectivity against ROCK1. An X-ray co-crystal structure of 9p in PKA supports the proposed rationale of ROCK1 selectivity.

A novel series of AKT inhibitors containing 2,3,5-trisubstituted pyridines with novel azaindazoles as hinge binding elements are described. Among these, the 4,7-diazaindazole compound 2c has improved drug-like properties and kinase selectivity than those of indazole 1, and displays greater than 80% inhibition of GSK3beta phosphorylation in a BT474 tumor xenograft model in mice.

Overexpression of AKT has an antiapoptotic effect in many cell types, and expression of dominant negative AKT blocks the ability of a variety of growth factors to promote survival. Therefore, inhibitors of AKT kinase activity might be useful as monotherapy for the treatment of tumors with activated AKT. Herein, we describe our lead optimization studies culminating in the discovery of compound 3g (GSK690693). Compound 3g is a novel ATP competitive, pan-AKT kinase inhibitor with IC 50 values of 2, 13, and 9 nM against AKT1, 2, and 3, respectively. An X-ray cocrystal structure was solved with 3g and the kinase domain of AKT2, confirming that 3g bound in the ATP binding pocket. Compound 3g potently inhibits intracellular AKT activity as measured by the inhibition of the phosphorylation levels of GSK3beta. Intraperitoneal administration of 3g in immunocompromised mice results in the inhibition of GSK3beta phosphorylation and tumor growth in human breast carcinoma (BT474) xenografts.

Abstract Akt kinases 1, 2, and 3 are important regulators of cell survival and have been shown to be constitutively active in a variety of human tumors. GSK690693 is a novel ATP-competitive, low-nanomolar pan-Akt kinase inhibitor. It is selective for the Akt isoforms versus the majority of kinases in other families; however, it does inhibit additional members of the AGC kinase family. It causes dose-dependent reductions in the phosphorylation state of multiple proteins downstream of Akt, including GSK3β, PRAS40, and Forkhead. GSK690693 inhibited proliferation and induced apoptosis in a subset of tumor cells with potency consistent with intracellular inhibition of Akt kinase activity. In immune-compromised mice implanted with human BT474 breast carcinoma xenografts, a single i.p. administration of GSK690693 inhibited GSK3β phosphorylation in a dose- and time-dependent manner. After a single dose of GSK690693, >3 μmol/L drug concentration in BT474 tumor xenografts correlated with a sustained decrease in GSK3β phosphorylation. Consistent with the role of Akt in insulin signaling, treatment with GSK690693 resulted in acute and transient increases in blood glucose level. Daily administration of GSK690693 produced significant antitumor activity in mice bearing established human SKOV-3 ovarian, LNCaP prostate, and BT474 and HCC-1954 breast carcinoma xenografts. Immunohistochemical analysis of tumor xenografts after repeat dosing with GSK690693 showed reductions in phosphorylated Akt substrates in vivo. These results support further evaluation of GSK690693 as an anticancer agent. [Cancer Res 2008;68(7):2366–74]

ND-2 Over-expression of AKT has an anti-apoptotic effect in many cell types and expression of dominant negative AKT blocks the ability of a variety of growth factors to promote survival. In addition, PTEN, a critical negative regulator of AKT, is lost in many cancers, including breast and prostate carcinomas, glioblastomas, and several cancer syndromes including Bannayan-Zonana syndrome, Cowden disease, and Lhermitte-Duclos disease. Therefore inhibitors of AKT kinase activity might be useful as monotherapy for the treatment of tumors with activated AKT. Herein, we will describe our lead optimization studies culminating in the discovery of GSK690693. GSK690693 is a novel ATP competitive, pan-AKT kinase inhibitor with IC 50 s of 2, 13 and 9 nM against AKT-1, 2 and 3, respectively. This compound binds in the ATP binding site as shown by an x-ray co-crystal structure with AKT2. >Treatment of tumor cells with GSK690693 causes dose dependent reductions in the phosphorylation state of multiple proteins downstream of AKT, including GSK3β, PRAS40 and Forkhead (FOXO1/FOXO3a). GSK690693 inhibits proliferation and induces apoptosis in a subset of tumor cells with potency that is consistent with intracellular inhibition of AKT kinase activity. >A single intraperitoneal (IP) administration of GSK690693 inhibits GSK3β phosphorylation in SCID mice bearing BT474 breast tumor xenografts in a dose and time-dependent manner. GSK690693 treatment (once daily for 21 days) produces significant anti-tumor activity in mice bearing established human SK-OV-3 ovarian, LNCaP prostate, and BT474 and HCC-1954 breast carcinoma xenografts. Immunohistochemical analysis of tumor xenografts after repeat dosing with GSK690693 demonstrates reductions in phosphorylated AKT substrates. The pharmacodynamic and antitumor effects of GSK690693 support its evaluation as an anticancer agent. >A summary of the pharmacokinetic properties and the description of a scalable synthetic route to GSK690693 will also be presented.

The shift in apparent IC(50) that attends addition of serum proteins to in vitro cellular, enzymatic, and receptor binding assays can be used to determine the dissociation constant for compound-serum protein complexes. We show here that a simple linear relationship exists between the apparent IC(50) in the presence of serum protein and the inverse of the apparent K(d) for the compound-serum protein complex. Using a series of cell-active kinase inhibitors we demonstrate that the K(d) value derived in this way can be used to predict the extent of protein binding in serum for various compounds. This method should provide a simple means of assessing the relative serum protein binding propensity of compounds early in the compound optimization phase of drug discovery campaigns.

Despite advances in the treatment of many side effects associated with chemotherapy, alopecia remains an issue that is difficult to resolve. Chemotherapy-induced alopecia (CIA) is a condition that can have profound psychosocial and quality-of-life consequences, resulting in anxiety, depression, a negative body image, lowered self-esteem, and a reduced sense of well-being. Patients who fear CIA may sometimes select regimens with less favorable outcomes or may refuse treatment. When supporting patients with CIA, health care providers should use an individualized approach with a focus placed on the actual moment of hair loss. Education, support groups, and self-care strategies are important components of any management approach. No treatment modality for preventing CIA has been clearly shown to be effective. Recent evidence suggests that new scalp hypothermic regimens may be safe and effective. There remains a critical need for effective new approaches to this problem.

We report on the rapid generation of two monoclonal antibodies, ATM A16.35 and ATM D16.11, that bind to the kinase domain of mutated ataxia telangiectasia (ATM). These antibodies were generated against E. coli-expressed recombinant protein using the RIMMS strategy. We show that ATM A16.35 binds ATM by Western blot analysis, and ATM D16.11 forms immune complexes with native ATM in immunoprecipitations without neutralizing kinase activity.

The product of the c- mos proto-oncogene is a protein kinase that is normally expressed in germ cells and functions during oocyte maturation. It has been shown, however, that inappropriate expression of either the viral or cellular mos gene can induce neoplastic progression in somatic cells. Furthermore, v- mos -transformed NIH3T3 cells will undergo arrest of proliferation in early G1 upon serum withdrawal but are unable to appropriately down-regulate cell cycle regulatory proteins, such as cyclin and cdc2 proteins, that normally are down-regulated in quiescent, untransformed NIH3T3 cells. Since the levels of these proteins are partially transcriptionally controlled, we investigated whether there were alterations in the expression of E2F and AP-1 transcription factor complexes. Indeed, the putative G0/G1-specific p130-E2F complex that is normally observed during low serum-induced cell cycle arrest in NIH3T3 cells is not present in serum starved v- mos -transformed cells. Instead, G1-phase arrested v- mos -transformed cells stably express two E2F protein complexes that are normally observed only during S-phase in untransformed cells. The elevation of these complexes in arrested v- mos -transformed cells may be the cause of the transcriptional activation of the E2F-regulated genes cdc2 , DHFR , cyclin A , and E2F1 seen in serum starved v- mos -transformed cells. In addition, there are high levels of AP-1 DNA binding activity in serum starved v- mos -transformed cells compared to very low amounts in non-transformed cells. This altered regulation of transcription factor complexes and cell cycle control proteins upon serum withdrawal may provide a mechanism for the uncontrolled cell growth associated with neoplastic transformation induced by certain proto-oncogenes.

Serum deprived v-mos-transformed NIH3T3 cells are unable to enter a true quiescent state, but instead, arrest in the early G1 phase of the cell cycle. We have analysed several cell cycle regulatory proteins in these G1 arrested cells and show altered regulation in the expression and activity of certain cyclins and cyclin-dependent kinases. In particular, p34cdc2, cyclin A, cyclin D and cyclin E are not appropriately down-regulated in serum starved, G1 arrested, v-mos-transformed cells as compared with quiescent NIH3T3 cells. Furthermore, serum starved v-mos-transformed cells have elevated histone H1 kinase activity associated with cyclin A, cyclin E, p33cdk2, and p34cdc2. Using a metallothionein-inducible c-mosmu expression system, we show that c-mosmu induction in quiescent NIH3T3 cells causes elevated expression of p34cdc2. However, this induction of c-mosmu and subsequent expression of p34cdc2 was not sufficient to promote significant entry of cells into S phase. Analysis of extracts from serum starved v-H-ras, v-src, and tpr-met transformed NIH3T3 cells demonstrates that these oncogene-transformed cells also contain elevated levels of p34cdc2. We propose that the altered regulation of these critical cell cycle regulatory molecules, and specifically the inability to fully downregulate their activity, contributes significantly to neoplastic transformation and subsequent unregulated growth of tumor cells.

The early events in the G2 checkpoint response to ionizing radiation (IR) were analyzed in diploid normal human fibroblasts (NHFs) and fibroblasts from patients with two heritable cancer syndromes. Exposure to gamma-radiation of asynchronously growing NHFs resulted in a rapid reduction in the number of cells in mitosis (G2 delay) and was accompanied by a quantitatively similar reduction in the p34CDC2/cyclin B in vitro histone H1 kinase activity as compared with sham-treated controls. This G2 delay was strong by 1 h following exposure to IR, maximal by 2 h, and was accompanied by an accumulation of tyrosine-phosphorylated p34CDC2 molecules. In contrast, fibroblasts from individuals with ataxia telangiectasia displayed significantly less reduction of the mitotic index or histone H1 kinase activity after IR. Low passage fibroblasts from individuals with Li-Fraumeni syndrome having one wild-type and one mutated p53 allele were similar to NHFs in their immediate G2 checkpoint response to IR, as were NHFs expressing the human papilloma virus type 16 E6 gene product (functionally inactivating p53) and low passage cells from p53-deficient mouse embryos. However, the p53-deficient fibroblasts were genomically unstable and became defective in their early G2 checkpoint response to IR. Furthermore, immortal Li-Fraumeni syndrome fibroblasts lacking wild-type p53 displayed an attenuated G2 checkpoint response. These results link the early events in G2 checkpoint response to IR in NHFs with a rapid inhibition of p34CDC2/cyclin B protein kinase activity and demonstrate that while not required for this immediate G2 delay, lack of p53 can lead to subsequent genetic alterations that result in defective G2 checkpoint function.

Research ArticleOpen AccessMolecular mechanisms of environmental carcinogenesis. N Rhodes, R S Paules, and J D Roberts N Rhodes Laboratory of Environmental Carcinogenesis and Mutagenesis, National Institute of Environmental Health Sciences, Research Triangle Park, NC 27709, USA. , R S Paules Laboratory of Environmental Carcinogenesis and Mutagenesis, National Institute of Environmental Health Sciences, Research Triangle Park, NC 27709, USA. , and J D Roberts Laboratory of Environmental Carcinogenesis and Mutagenesis, National Institute of Environmental Health Sciences, Research Triangle Park, NC 27709, USA. Published:1 May 1995https://doi.org/10.1289/ehp.95103504Cited by:1AboutSectionsPDF ToolsDownload CitationsTrack Citations ShareShare onFacebookTwitterLinked InReddit FiguresReferencesRelatedDetailsCited by Indulski J and Lutz W Molecular Epidemiology: Cancer Risk Assessment Using Biomarkers for Detecting Early Health Effects in Individuals Exposed to Occupational and Environmental Carcinogens, Reviews on Environmental Health, 10.1515/REVEH.1997.12.3.179, 12:3 Vol. 103, No. 5 May 1995Metrics About Article Metrics Publication History Originally published1 May 1995Published in print1 May 1995 Financial disclosuresPDF download License information EHP is an open-access journal published with support from the National Institute of Environmental Health Sciences, National Institutes of Health. All content is public domain unless otherwise noted. Note to readers with disabilities EHP strives to ensure that all journal content is accessible to all readers. However, some figures and Supplemental Material published in EHP articles may not conform to 508 standards due to the complexity of the information being presented. If you need assistance accessing journal content, please contact [email protected]. Our staff will work with you to assess and meet your accessibility needs within 3 working days.

The product of the mos protooncogene normally functions in the induction of meiosis and regulation of cell-cycle progression in oocytes. Here we have investigated the cell-cycle progression of NIH3T3 cells transformed by the v-mos gene. Flow cytometric analysis showed that logarithmically growing v-mos-transformed cells do not differ from their nontransformed counterparts in the distribution of cells in the G1, S, and G2/M phases. Likewise, after serum withdrawal for 48 h, both normal and v-mos-transformed NIH3T3 cells have essentially ceased proliferation, as analyzed by flow cytometry, [3H]thymidine and BrdU incorporation into newly synthesized DNA, and mitotic indexes. However, while the normal NIH3T3 cells are arrested in a quiescent state, the v-mos-transformed cells are arrested in early to mid G1, prior to the point where cells require certain amino acids for proliferation (V point). In agreement with these different arrest points, the v-mos-transformed cells enter S phase following serum stimulation within about 8 h, without the additional 4- to 6-h lag period characteristically displayed by the parental NIH3T3 cells. In addition, we show a lack of expression of a growth arrest-specific gene product, gas1, in the serum-arrested v-mos-transformed cells. These data demonstrated that v-mos-transformed cells display growth characteristics that differ fundamentally from those of normal cells or cells transformed by overexpression of myc [1]. Our results suggest that the v-mos oncoprotein transforms cells, at least in part, by preventing exit from the cell cycle into quiescence.

The STE11 gene of Saccharomyces cerevisiae is one of several genes required for mating between two haploid cell types of this yeast. Its product is required for response to a signal that causes arrest of the mitotic cell cycle in the G1 phase and induction of mating-type-specific genes. The nucleotide sequence of the STE11 gene was determined. The predicted amino acid sequence shows homology to the protein kinase family. We demonstrate that the STE11 product has kinase catalytic activity and that this activity is required for its in vivo functions.