IntroductionIn contrast to its role in breast cancer (BCa) initiation, estrogen signaling has a protective effect in later stages, where estrogen receptor (ER)α loss associates with aggressive metastatic disease. We asked whether the beneficial effect of estrogen signaling in late-stage BCa is attributable to the recently reported estrogen-mediated antagonism of the pro-metastatic transcription factor Runx2.MethodsMCF7/Rx2dox breast cancer cells were engineered with a lentivirus expressing Runx2 in response to doxycycline (dox). Cells treated with dox and/or estradiol (E2) were subjected to genome-wide expression profiling, RT-qPCR analysis of specific genes, and Matrigel™ invasion assays. Knockdown of genes of interest was performed using lentiviruses expressing appropriate shRNAs, either constitutively or in response to dox. Gene expression in BCa tumors was investigated using a cohort of 557 patients compiled from publicly available datasets. Association of gene expression with clinical metastasis was assessed by dichotomizing patients into those expressing genes of interest at either high or low levels, and comparing the respective Kaplan-Meier curves of metastasis-free survival.ResultsRunx2 induced epithelial-mesenchymal transition (EMT) evidenced by acquisition of a fibroblastic morphology, decreased expression of E-cadherin, increased expression of vimentin and invasiveness. Runx2 stimulated SNAI2 expression in a WNT- and transforming growth factor (TGF)β-dependent manner, and knockdown of SNAI2 abrogated the pro-metastatic activities of Runx2. E2 antagonized the pro-metastatic activities of Runx2, including SNAI2 upregulation. In primary BCa tumors, Runx2 activity, SNAI2 expression, and metastasis were positively correlated, and SNAI2 expression was negatively correlated with ERα. However, the negative correlation between SNAI2 and ERα in bone-seeking BCa cells was weaker than the respective negative correlation in tumors seeking lung. Furthermore, the absence of ERα in primary tumors was associated with lung- and brain- but not with bone metastasis, and tumor biopsies from bone metastatic sites displayed the unusual combination of high Runx2/SNAI2 and high ERα expression.ConclusionsE2 antagonizes Runx2-induced EMT and invasiveness of BCa cells, partly through attenuating expression of SNAI2, a Runx2 target required for mediating its pro-metastatic property. That ERα loss promotes non-osseous metastasis by unleashing Runx2/SNAI2 is supported by the negative correlation observed in corresponding tumors. Unknown mechanisms in bone-seeking BCa allow high Runx2/SNAI2 expression despite high ERα level

these results are the first to indicate that the KRAS 3'UTR polymorphism may predict for cetuximab responsiveness in KRASwt mCRC patients, which warrants validation in other clinical trials.

Inherited and somatic mutations in the APC gene, a human tumor-suppressor, occur in a large percentage of colon cancers, leading to elevated levels of nuclear beta-Catenin, and to activation of TCF/beta-Catenin-responsive genes including cyclin D1 and c-myc. To identify small molecule antagonists of this pathway, we screened transformed colorectal cells with a secondary structure-templated chemical library, in search of compounds that attenuated a TCF/beta-Catenin-responsive reporter gene. From this library we selected ICG-001 (IC50=3 microM) as a lead compound. Design and synthesis of the chemical library and some preliminary biological evaluation is described.

Some 1,857 highly cited reviews, namely those cited at least 1,000 times since publication to 2011, were identified using the data hosted on the Science Citation Index Expanded ™ database (Thomson Reuters, New York, NY) between 1899 and 2011. The data are disaggregated by publication date, citation counts, journals, Web of Science ® (Thomson Reuters) subject areas, citation life cycles, and publications by Nobel Prize winners. Six indicators, total publications, independent publications, collaborative publications, first-author publications, corresponding-author publications, and single-author publications were applied to evaluate publication of institutions and countries. Among the highly cited reviews, 33% were single-author, 61% were singleinstitution, and 83% were single-country reviews. The United States ranked top for all 6 indicators. The G7 (United ) countries were the site of almost all the highly cited reviews. The top 12 most productive institutions were all located in the United States with Harvard University (Cambridge, MA) the leader. The top 3 most productive journals were Chemical Reviews, Nature, and the Annual Review of Biochemistry. In addition, the impact of the reviews was analyzed by total citations from publication to 2011, citations in 2011, and citation in publication year.

2501 Background: PRI-724 is a first-in-class modulator of Wnt signaling that inhibits the CREB binding protein and β-catenin interaction. In pre-clinical models, PRI-724 (active metabolite C82) increases p300/β-catenin binding and promotes stem cell differentiation thereby eliminating tumor initiating cells and increasing sensitivity to cytotoxic or targeted drugs. Methods: PRI-724 was given as a continuous infusion X 7 days q 2 wks. There was an initial accelerated dose escalation with one pt per dose level and a plan to revert to a 3+3 escalation after 640 mg/m2 unless a dose limiting toxicity (DLT) or 2 moderate toxicities occurred earlier. Eligibility criteria: adequate bone marrow function, AST/ALT <5XULN, total bilirubin<1.5 mg/dL. Survivin/BIRC5 expression was measured by immunomagnetic RT-PCR on circulating tumor cells (CTC). Results: 18 pts treated; median age: 53 years (38-71); 12 (67%) males; median number of prior therapies: 3 (1-5). There was one DLT of grade 3 hyperbilirubinemia. Grade 3 AEs were limited to hyperbilirubinemia in 2 pts, one of which did not meet DLT criteria. Grade 2 AEs were: diarrhea (2pts; 11%), bilirubin elevation (2 pts; 11%), hypophosphatemia (2pts; 11%), nausea (1pt; 6%), fatigue (1pt; 6%), anorexia (1pt; 6%), thrombocytopenia (1 pt; 6%) and alkaline phosphatase elevation (1pt; 6%). There was no MTD at the doses tested. The recommended phase 2 dose was 905 mg/m2 based on the incidence of AEs at 1280 mg/m2 and the plateau in pK parameters. The median Cmax and AUC 0-t for C-82 at 905 mg/m2/day were 887 ng/mL and 262787 h*ng/mL. Median elimination T ½ was 7.35 h. 3 pts with colon cancer had stable disease for 8, 10 and 12 weeks. Survivin expression in CTCs decreased in 72% of pts on C1D8 and 61% on C2D8. There was an inverse relationship between C82 plasma concentration and survivin expression on C1D8 (Spearman correlation coefficient r = -0.72; p=0.001). Conclusions: PRI-724 had an acceptable toxicity profile. Downregulation of survivin expression in CTCs may serve as a pharmacodynamic marker of drug-on-target effect. Studies combining PRI-724 with chemotherapy are ongoing. Clinical trial information: NCT01302405. [Table: see text]