Biological evaluation of indolactams for in vitro bryostatin 1-like activity

Small molecule activators of protein kinase C (PKC) have traditionally been classified as either tumor promoters or suppressors. Although bryostatin 1 has well established anti-cancer activity, most natural products that target the PKC regulator domain exhibit tumor promotion properties. In this study, we examine a focused library of indolactam analogues in cell-based assays to establish the structural features of the scaffold that enhance bryostatin 1-like activity. These systematic biological assessments identified specific indole substitution patterns that impart diminished tumor promotion behavior in vitro for indolactam analogues, while still maintaining nanomolar potency for PKC.

Comparing clinical outcomes following 1 year of dual antiplatelet therapy in patients risk stratified by the PRECISE-DAPT and DAPT scores

Background

Dual antiplatelet therapy (DAPT) is the standard of care following PCI. DAPT reduces ischemic events but increases bleeding risk. Duration of DAPT following PCI remains controversial. Current guidelines recommend duration be individualized based on risk of ischemia and bleeding. Although multiple strategies exist to risk stratify patients, including application of the PRECISE-DAPT and DAPT scores, there is currently no standardized risk assessment protocol.

Purpose

To determine if the PRECISE-DAPT and DAPT scores can identify patients at increased risk of ischemia or bleeding in a cohort prescribed 12 months of DAPT following PCI.

Methods

We calculated the PRECISE-DAPT and DAPT scores for 469 consecutive patients at baseline after PCI. Patients were grouped based on score treatment recommendation; PRECISE-DAPT prolonged or shortened (PRECISE DAPT <25 vs. ≥25) and DAPT prolonged or shortened (DAPT ≥2 vs <2). End points included 1-year rates of major adverse cardiovascular events (MACE) and TIMI major or minor bleeding.

Results

Among 469 patients, mean age was 64.4 (SD 12.2); 102 (21.7%) were women. Index presentation consisted of a STEMI in 207 (44.1%), NSTEMI in 99 (21.1%), and UA in 60 (12.8%). At presentation, 174 (37.1%) were current smokers, 115 (24.5%) had a prior MI, 118 (25.2%) had diabetes, 249 (53.1%) had dyslipidemia and 281 (60.0%) were previously diagnosed as hypertensive. Overall, there was an increase in bleeding and no difference in MACE for patients with a PRECISE-DAPT score ≥25 (13.3% vs. 4.1% P<0.001). No difference in bleeding or MACE was present in patients stratified by the DAPT score.

Conclusion

A PRECISE-DAPT score ≥25 was associated with an increased rate of bleeding and no difference in MACE in patients prescribed 12 months of DAPT. This supports the use of the PRECISE-DAPT as a prospective tool in clinical practice.

Funding Acknowledgement

Type of funding source: None

Small Molecule Intervention in a Protein Kinase C-Gli Transcription Factor Axis

Aberrations in the Hedgehog (Hh) signaling pathway are responsible for a broad range of human cancers, yet only a subset rely on the activity of the clinical target, Smoothened (Smo). Emerging cases of cancers that are insensitive to Smo-targeting drugs demand new therapeutic targets and agents for inhibition. As such, we sought to pursue a recently discovered connection between the Hedgehog pathway transcription factors, the glioma-associated oncogene homologues (Glis), and protein kinase C (PKC) isozymes. Here, we report our assessment of a structurally diverse library of PKC effectors for their influence on Gli function. Using cell lines that employ distinct mechanisms of Gli activation up- and downstream of Smo, we identify a PKC effector that acts as a nanomolar Gli antagonist downstream of Smo through a mitogen-activated protein kinase kinase (MEK)-independent mechanism. This agent provides a unique tool to illuminate crosstalk between PKC isozymes and Hh signaling and new opportunities for therapeutic intervention in Hh pathway-dependent cancers.

P1933Comparing treatment recommendations for the DAPT and PRECISE-DAPT scores after percutaneous coronary intervention

Background

Dual antiplatelet therapy (DAPT), with aspirin and a P2Y12 inhibitor, is the standard therapy for patients following PCI. Duration of treatment with DAPT has been controversial despite large studies. Current guidelines recommend treatment duration be individualized based on risk of ischemia and bleeding. To facilitate treatment decisions, risk assessment tools, including the DAPT and PRECISE-DAPT scores, have been developed.

Purpose

As components of these scores differ, the variability of recommendation remains unknown. We set to evaluate inter-tool concordance in treatment recommendation in a cohort of patients after PCI.

Methods

Using data from our local PCI registry, we calculated the PRECISE-DAPT at baseline following PCI and the DAPT after 1 year of treatment for 311 consecutive patients with complete data for both scores to be calculated. Based on their DAPT and PRECISE-DAPT scores, patients were grouped into concordant for long-term treatment (DAPT ≥2 and PRECISE-DAPT <25) or concordant for shortened treatment (DAPT <2 and PRECISE- DAPT ≥25). All other patients were considered discordant. We then performed a concordance analysis using Cohen's kappa to measure degree of agreement.

Results

Among the 311 patients, mean age was 63.4 (SD 11.6); 245 (79%) were men, 93 (29.9%) had history of a prior MI, 130 (41.8%) were current smokers, 32 (10.3%) had a history of CHF or LVEF <30%, 82 (26.3%) had diabetes and 196 (63.0%) were previously diagnosed with hypertension. Index event consisted of a STEMI in 101 (32.4%), NSTEMI in 93 (29.9%), unstable angina in 27 (8.7%), stable angina in 67 (21.5%) and the remaining 23 (7.4%) had other indications for PCI. Mean DAPT score was 1.52 (SD 1.37). Mean PRECISE-DAPT was 17.65 (SD 12.73). The DAPT recommended long-term treatment for 162 (52.1%) and shortened treatment for 149 (47.9%). The PRECISE-DAPT recommended long-term treatment for 245 (78.9%) and shortened treatment for 66 (21.2%). The overall proportion of agreement between the two risk scores was 56.6% with a Cohen's kappa index of 0.110 (95% CI, 0.017 to 0.204). See Table.

Concordance Analysis PRECISE-DAPT Score Recommendation Long Term (N=245) Shortened (N=66) DAPT Score Recommendation Long Term (N=162) 136 (43.7%) 26 (8.4%) Concordant for Long Term Treatment Shortened (N=149) 109 (35%) 40 (12.8%) Concordant for Shortened Treatment

Conclusion

Comparison of the DAPT score and the PRECISE-DAPT score showed concordance in treatment recommendation in only 56.6% of patients. Given the poor agreement between these tools, prospective concurrent evaluations and correlation to outcomes will be required in future studies.

Implementation of an integrated cancer care network

e17564

Background: In 1998, the province of Quebec adopted its cancer control program (CP). Its goal was to establish a hierarchical and integrated cancer network of interdisciplinary teams. In 2004, a team evaluation process was initiated by the Direction de la lutte contre le cancer (ministry of health) to help implement this program. Methods: The evaluation consisted of completion of a matrix by the requesting team, a visit by a multidisciplinary group of experts and a report card. Three levels of expertise were assessed: core (all), regional (regional hospitals), and supraregional (tumor specific/complex situations). The matrix was based on the fundamental orientations of the CP, thus setting the framework for patient centered care. The conformity indicators were mainly structural and process oriented. In order to be evaluated for the subsequent mandates, teams had to conform to the core mandate. Those who did not succeed had one year to reapply. Mandates are for 4 years. Results: Teams were able to comply with most of the elements of the evaluation matrix. Sessions for clarification and coaching about this new interdisciplinary approach were necessary and helpful. A total of 153 visits were done:70 for core, 8 for regional and 75 for supraregional mandates respectively. Major health institutions such as university hospitals applied for multiple supraregional team designation. In all, 130 teams had their designation confirmed. This process highlighted some common weaknesses such as the lack of use of data for quality control. Conclusions: Acceptance of this hierarchical cancer care model was facilitated by the fact that it was in line with the integrated health care network of Quebec. The evaluation process has had an impact on the way cancer care is delivered in Quebec. This initial phase has helped implement an interdisciplinary patient centered model of care in line with the CP. Participation of different experts has also helped foster knowledge transfer and appropriation of the process. Impact on patient care and satisfaction remains to be assessed. An initial patient's questionnaire has been completed in 2008 and will serve as a control to future surveys.

No significant financial relationships to disclose.

Identification and expression of the mammalian homologue of Bicaudal-C

Translational activation and repression play an important role in the spatial-temporal regulation of gene expression in embryonic development. Bicaudal-C is an RNA-binding molecule believed to function at this post-transcriptional level. Loss-of-function mutants in Drosophila affect anterior-posterior patterning because of ectopic and premature translation of the posterior determinant oskar. The Xenopus homologue of Bicaudal-C is one of the few molecules that, when microinjected ectopically, results in endoderm formation in the absence of mesoderm induction. Here we report the sequence and expression pattern of the murine and human homologues of Bicaudal-C. The human gene is located on chromosome 10q21.2. Expression analysis in mouse using in situ hybridization detects expression of Bicaudal-C not only in domains detected in Xenopus, but also in previously unreported regions. As in Xenopus, mouse Bicaudal-C mRNA is found in the growing oocyte, Hensen's node, and the developing kidney. Additionally, at later stages it is strongly expressed in the developing gut endoderm, in areas of cartilage formation, in pleuro-peritoneal membrane derivatives, in lung mesenchyme, and in the stroma of the ovary. We conclude that mouse Bicaudal-C is a maternally provided gene product that is tightly regulated during mammalian cell differentiation.

Neuralin-1 is a novel Chordin-related molecule expressed in the mouse neural plate

Cysteine-rich repeats (CRs) of the type described in Chordin constitute conserved domains present in an expanding family of secreted molecules. These motifs were shown to mediate directly the antagonism of BMP signaling by Chordin and play a major role during development. Here we report the cloning and expression pattern of neuralin-1, a new member of the chordin family. The mouse cDNA was cloned by homology with a human genomic sequence encoding putative CRs. In the human genome, neuralin-1 transcripts are encoded by 8 exons that span a region of at least 80 kilobases located on chromosome Xq22.1-23. Neuralin-1 is a 333 amino acid protein containing three CRs, two of them highly similar to the Chordin CRs that bind BMP. Like chordin, neuralin-1 is able to induce secondary axes after mRNA injection in Xenopus embryos. Interestingly, during late gastrulation, neuralin-1 and chordin present distinct and complementary expression patterns in the mouse: neuralin-1 expression starts in the neural plate at mid-gastrulation, whereas chordin expression at that stage is restricted to the node and midline mesendoderm. Later on, neuralin-1 expression becomes restricted to discrete regions of the central nervous system and to derivatives of the neural crest cells. During organogenesis, neuralin-1 presents a broad expression pattern in many tissues such as dorsal root ganglia, gut, condensing cartilages of the skeleton and developing hair follicles.

Interaction of goosecoid and brachyury in Xenopus mesoderm patterning

Detailed in situ analyses reveal overlapping expression of gsc and Xbra in the early Spemann's organizer. Coexpression is lost during gastrulation suggesting an interaction between these genes. Ectopic expression of gsc ventrally suppresses endogenous Xbra expression and transcription from Xbra promoter reporter gene constructs. Suppression is mediated, at least partially, by a gsc-binding site within the first 349 bp of the promoter. Xbra reporter gene transcription is also suppressed in the region of endogenous gsc expression, whereas high-level ectopic Xbra expression has no effect on endogenous gsc expression. We suggest that early patterning of the vertebrate mesoderm, like early patterning of the Drosophila embryo, occurs by first establishing broad domains of gene expression which are subsequently refined by intergenic interactions to further delimit tissue boundaries.