<div>Abstract<p>Targeting the ataxia telangiectasia and RAD3-related (ATR) enzyme represents a promising anticancer strategy for tumors with DNA damage response (DDR) defects and replication stress, including inactivation of ataxia telangiectasia mutated (ATM) signaling. We report the dose-escalation portion of the phase I first-in-human trial of oral ATR inhibitor BAY 1895344 intermittently dosed 5 to 80 mg twice daily in 21 patients with advanced solid tumors. The MTD was 40 mg twice daily 3 days on/4 days off. Most common adverse events were manageable and reversible hematologic toxicities. Partial responses were achieved in 4 patients and stable disease in 8 patients. Median duration of response was 315.5 days. Responders had ATM protein loss and/or deleterious <i>ATM</i> mutations and received doses ≥40 mg twice daily. Overall, BAY 1895344 is well tolerated, with antitumor activity against cancers with certain DDR defects, including ATM loss. An expansion phase continues in patients with DDR deficiency.</p>Significance:<p>Oral BAY 1895344 was tolerable, with antitumor activity in heavily pretreated patients with various advanced solid tumors, particularly those with <i>ATM</i> deleterious mutations and/or loss of ATM protein; pharmacodynamic results supported a mechanism of action of increased DNA damage. Further study is warranted in this patient population.</p><p><i>See related commentary by Italiano, p. 14</i>.</p><p><i>This article is highlighted in the In This Issue feature, p. 1</i></p></div>
SUMMARY This study describes the identification and target deconvolution of novel small molecule inhibitors of oncogenic YAP1/TAZ activity with potent anti-tumor activity in vivo. A high-throughput screen (HTS) of 3.8 million compounds was conducted using a cellular YAP1/TAZ reporter assay. Target deconvolution studies identified the geranylgeranyltransferase-I (GGTase-I) complex, as the direct target of YAP1/TAZ pathway inhibitors. The novel small molecule inhibitors block the activation of Rho-GTPases, leading to subsequent inactivation of YAP1/TAZ and inhibition of cancer cell proliferation in vitro. Multi-parameter optimization resulted in BAY-593, an in vivo probe with favorable PK properties, which demonstrated anti-tumor activity and blockade of YAP1/TAZ signaling in vivo . SIGNIFICANCE YAP1/TAZ have been shown to be aberrantly activated oncogenes in several human solid tumors, resulting in enhanced cell proliferation, metastasis and provision of a pro-tumorigenic microenvironment, making YAP1/TAZ targets for novel cancer therapies. Yet, the development of effective inhibitors of these potent oncogenes has been challenging. In this work, we break new ground in this direction through the identification of novel inhibitors of YAP1/TAZ activity. Graphical abstract HIGHLIGHTS Novel YAP1/TAZ pathway inhibitors identified by phenotypic high-throughput screen Target deconvolution identifies GGTase-I as the direct target of the novel YAP1/TAZ pathway inhibitors GGTase-I inhibitors block Rho-GTPase signaling and downstream YAP1/TAZ GGTase-I inhibitor BAY-593 demonstrates potent anti-tumor activity in vivo
<div>Abstract<p>The DNA damage response (DDR) secures the integrity of the genome of eukaryotic cells. DDR deficiencies can promote tumorigenesis but concurrently may increase dependence on alternative repair pathways. The ataxia telangiectasia and Rad3-related (ATR) kinase plays a central role in the DDR by activating essential signaling pathways of DNA damage repair. Here, we studied the effect of the novel selective ATR kinase inhibitor BAY 1895344 on tumor cell growth and viability. Potent antiproliferative activity was demonstrated in a broad spectrum of human tumor cell lines. BAY 1895344 exhibited strong monotherapy efficacy in cancer xenograft models that carry DNA damage repair deficiencies. The combination of BAY 1895344 with DNA damage–inducing chemotherapy or external beam radiotherapy (EBRT) showed synergistic antitumor activity. Combination treatment with BAY 1895344 and DDR inhibitors achieved strong synergistic antiproliferative activity <i>in vitro</i>, and combined inhibition of ATR and PARP signaling using olaparib demonstrated synergistic antitumor activity <i>in vivo</i>. Furthermore, the combination of BAY 1895344 with the novel, nonsteroidal androgen receptor antagonist darolutamide resulted in significantly improved antitumor efficacy compared with respective single-agent treatments in hormone-dependent prostate cancer, and addition of EBRT resulted in even further enhanced antitumor efficacy. Thus, the ATR inhibitor BAY 1895344 may provide new therapeutic options for the treatment of cancers with certain DDR deficiencies in monotherapy and in combination with DNA damage–inducing or DNA repair–compromising cancer therapies by improving their efficacy.</p></div>
Abstract Global miRNA profiles are particularly informative regarding cell lineage and the differentiation state of tumours. Recent studies also indicate specific miRNAs are upregulated in following drug treatment and in poor prognosis or metastatic disease. The aims of this study were to determine if miRNA profiles could be used to segment a 50 colorectal cell line panel into clinically relevant sub-types and to determine if the miRNA data enhanced prediction of pharmacological response. The global miRNA profile was examined using unsupervised two dimensional hierarchical clustering which revealed a small group of miRNAs which displayed reciprocal expression between the cell line clusters. A subset of 9 miRNAs, miR192 cluster (3 miRs), miR125b (3miRs) cluster and a miR200 negative cluster (3miRs) defined three cell sub-types. These miRs have been associated with intestinal differentiation, poor prognosis/metastasis in CRC and mesenchymal transition respectively. Importantly, the cell sub-types defined by miRNAs directly relate to sub-types defined by iterative clustering of mRNA data in clinical CRC tissue. Analysis of differentially expressed genes between the cell sub-types revealed the expected differences in EMT genes between the miR200 negative cluster and the miR125b and miR192 clusters. Interestingly, the miR192 positive sub-type was discriminated from the miR125b positive cluster by higher expression of several genes specifically associated with intestinal differentiation including CDX1 (71-fold), HNF1a (TCF1) (3-fold), HNF4a (TCF14) (10-fold), HNF4G (5-fold) ISX (12-fold), and IHH (24-fold). Significantly, there were also differences in mRNA expression of genes related to drug sensitivity e.g. ERBB3 (3.6-fold), AREG (3-fold). In contrast, the miR125b subtype had high expression of IRX3 (12-fold) a homeobox gene associated with neural differentiation and increased expression of the oncogene Axl (6-fold). Protein data revealed the miR192 positive sub-type also had higher expression of ERBB2 and B-catenin and lower levels of phosphorylation of AKT substrate, p70S6K and S6 when compared to the miR200 negative and miR125b clusters. The miR192 sub-type also exhibited greater sensitivity to ERB and MEK targeted agents compared to the miR200 and miR125b sub-types. Taken together, the miR data enables segregation by differentiation status, this data enhances prediction of drug activity compared to mutation data alone and is of significance because both miR expression and differentiation status are modulated by prior chemotherapy regimes. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr LB-455. doi:1538-7445.AM2012-LB-455
<div>Abstract<p>The DNA damage response (DDR) secures the integrity of the genome of eukaryotic cells. DDR deficiencies can promote tumorigenesis but concurrently may increase dependence on alternative repair pathways. The ataxia telangiectasia and Rad3-related (ATR) kinase plays a central role in the DDR by activating essential signaling pathways of DNA damage repair. Here, we studied the effect of the novel selective ATR kinase inhibitor BAY 1895344 on tumor cell growth and viability. Potent antiproliferative activity was demonstrated in a broad spectrum of human tumor cell lines. BAY 1895344 exhibited strong monotherapy efficacy in cancer xenograft models that carry DNA damage repair deficiencies. The combination of BAY 1895344 with DNA damage–inducing chemotherapy or external beam radiotherapy (EBRT) showed synergistic antitumor activity. Combination treatment with BAY 1895344 and DDR inhibitors achieved strong synergistic antiproliferative activity <i>in vitro</i>, and combined inhibition of ATR and PARP signaling using olaparib demonstrated synergistic antitumor activity <i>in vivo</i>. Furthermore, the combination of BAY 1895344 with the novel, nonsteroidal androgen receptor antagonist darolutamide resulted in significantly improved antitumor efficacy compared with respective single-agent treatments in hormone-dependent prostate cancer, and addition of EBRT resulted in even further enhanced antitumor efficacy. Thus, the ATR inhibitor BAY 1895344 may provide new therapeutic options for the treatment of cancers with certain DDR deficiencies in monotherapy and in combination with DNA damage–inducing or DNA repair–compromising cancer therapies by improving their efficacy.</p></div>
Abstract The aims of this study were to determine if miRNA profiles could enhance prediction of pharmacological response compared to mutation alone. miRNAs are readily detectable in serum and plasma thus could be used in combination with mutations in liquid biopsies to support patient selection. Unsupervised hierarchical clustering of a 50 cell line panel global miRNA profile revealed a subset of miRNAs with a striking reciprocal expression pattern. Expression of miR-192+ve (3 miRs), miR-125b+ve (3miRs) and miR-200-ve (3miRs) defined 3 main cell sub-types which were further divided into 5 subtypes by expression of miR31+ve. Significantly, the miRNA sub-types are closely related to the five mRNA subtypes we had previously identified using iNMF (Schlicker et al, 2012) and to the subtypes identified in clinical CRC samples by Sadanandam et al 2013, Loboda et al, 2012 and Oh et al 2012. The miR192+ve subtype is an epithelial sub-type (iNMF sub-type 2 / Oh A-type) which has a gene expression pattern found in cells with transit amplifying phenotype, whereas the miR200 negative sub-type relates to the mesenchymal iNMF sub-type 1.1 and has a gene expression pattern similar to that found in CRC stem-like cells. Expression of miR125b is found in the stem-like subtype but also in mesenchymal sub-types with gene expression related to an inflammatory phenotype (iNMF sub-type 1.2, Oh B). Analysis of differentially expressed genes between the sub-types revealed the miR-192+ve positive sub-type was discriminated from the miR-125b+ve by higher expression of several genes specifically associated with intestinal differentiation including HNF1a (TCF1) (3-fold) and HNF4a (TCF14) (13-fold) which drive expression of miR192 and CDX1 (71-fold), HNF4G (6-fold) ISX (12-fold), and IHH (24-fold). TCGA clinical samples were also classified by the four mRNA methods and miRNAs differentially expressed between the sub-types analysed; all of the miRNAs identified in cell lines were statistically significantly differentially expressed in TCGA sub-types, however, there were additional miRNAs which clearly correlate with sub-types in clinical samples that have very low expression in cells. Importantly, the miR-192+ve sub-type exhibited significantly greater sensitivity to EGFR TKIs, cetuximab and MEK targeted agents compared to the miR-200-ve and miR-125b+ve sub-types. Taken together, the miR data enables segregation by differentiation status, this data enhances prediction of drug activity compared to mutation data alone and is of significance because miR expression and differentiation status are modulated by prior chemotherapy regimes. Citation Format: Christine M. Chresta, Andreas Schlicker, Garry Beran, Georgia Cerillo, Lodewyk F. A. Wessels, George Orphanides. Reciprocal expression of miR-125b and miR-192/miR-200 families define clinically relevant sub-types of colorectal cancer with differential sensitivity to EGFR and MEK targeted agents. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 5559. doi:10.1158/1538-7445.AM2014-5559
