An Integrative Review of Micro-Credentials and Digital Badges for Pharmacy Educators

Micro-credentials (MCs) and digital badges (DBs) have gained popularity in recent years as a means to supplement traditional degrees and certifications. MCs and DBs can play a significant role in supporting student-centered learning by offering personalized and flexible learning pathways, emphasizing real-world relevance and practical skills, and fostering a culture of continuous learning and growth. However, barriers currently exist within health professions education, including pharmacy education, that could limit the full adoption and implementation of MCs and DBs. Research on the use of MCs and DBs in Doctor of Pharmacy degree programs is sparse. In this integrative review, literature on the use of MCs and DBs in health professions education is reviewed, and perspectives on the benefits, issues, and potential future uses within Doctor of Pharmacy degree programs are presented.

Abstract 2973: Rac inhibitors for cancer therapy

Among all cancers worldwide, breast cancer is the first cause of death in women. One of the most aggressive subtypes of breast cancer is the triple negative form, which account for the 10-15% of breast cancer cases. Due to its complex heterogeneity triple negative breast cancer available treatments are limited, being chemotherapy in the first line of use. Despite advances in the search for new treatments, there is still a lack of effective therapies, being the metastatic disease the principal cause of breast cancer mortality. Therefore, it is critical to develop a new and effective strategies to inhibit metastasis. The Rho GTPase Rac has been identified as a promising target for anti-metastatic cancer therapy as it has been shown to play key roles in metastatic cancer cells dynamics as: cellular adhesion, migration, proliferation, survival and invasion. To this extent, in an effort to find a compound with increased Rac inhibitory capacity our group developed Ehop-016 derivatives HV-107 and HV-118. Previously we have reported HV-107 and HV-118 to affect cell viability promoting a G2-M cell cycle arrest with a sub-G1 population indicative of cell death in MDA-MB-231. Also, an increase of caspases activity validating apoptosis as a mechanism of cell death was shown. In addition, a decrease in tumor growth and metastasis by ~35 to 40% in an in vivo study using HV-118 at 1 mg/kg body weightwas also reported. Currently, through pulldown assays we have showed HV-107 and HV-118 to inhibit Rac activity at~500-2000 nM and 10 nM respectively in MDA-MB-231 and MDA-MB-468 breast cancer cells. Using trypan blue excision assay HV-107(>500 nM) and HV-118(>50 nM) were shown to affect cell viability promoting a G2-M cell cycle arrest in MDA-MB-468. We also demonstrated HV-107 and HV-118 to inhibit the direct downstream effector of Rac, PAK at >500 nM(HV-107) and >50 nM(HV-118) in MDA-MB-231 cells. In addition, HV-107 was also shown to increase Rho activity at concentrations significantly higher than the effective for Rac inhibition. Rho activity up-regulation has been reported to negatively affect migration of cancerous cells. Finally, we tested HV-107 in a mouse model of metastatic breast cancer. A decrease of ~ 40% in liver metastasis was shown for mice treated with 5 mg/kg BW HV-107. Taken together, our results indicate HV-107 and HV-118 are approximately 4-100 times more efficient than the parent compound Ehop-016 and have potential as anti-breast cancer metastasis therapeutics.

This study is supported by NIH Grant 1SC1GM122691, and PRINBRE P20GM103475 from NIGMS of the NIH to GVC

Citation Format: Grace Enid Velez Crespo, Eliud Hernandez, Suranganie Dharmawardhane, Cornelis Vlaar, Linnette Castillo, Lilia Kucheryavykh. Rac inhibitors for cancer therapy [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 2973.

POS0596 SERUM CHOLESTEROL LOADING CAPACITY ON MACROPHAGES IS LINKED TO OXIDIZED LOW-DENSITY LIPOPROTEIN AND REGULATED BY SEROPOSITIVITY AND C-REACTIVE PROTEIN IN PATIENTS WITH RHEUMATOID ARTHRITIS

Background

Excessive cholesterol accumulation in macrophages underlies foam cell formation, initiation and progression of atherosclerosis. LDL oxidation and unregulated uptake of oxidized LDL by macrophages are critical in foam cell development. Cholesterol loading capacity (CLC) is the ability of serum to deliver cholesterol to cells and is related to foam cell formation. Rheumatoid arthritis (RA) serum increased cholesterol content in macrophages and promoted foam cell formation significantly more than control serum1. Although inflammation, LDL oxidation and antibodies to oxidized LDL (anti-oxLDL) may be higher in RA, their relationships and their individual and synergistic contributions to CLC in RA are unknown.

Objectives

To explore determinants and moderators of serum CLC in patients with RA. We also investigated whether oxidized LDL influences CLC directly or indirectly through anti-oxLDL IgG and proprotein convertase subtilisin/Kexin type-9 (PCSK9), independently or conditionally on RA-related autoantibodies such as rheumatoid factor (RF) and anti-citrullinated protein antibodies (ACPA) or level of inflammation.

Methods

In an observational study of 104 patients, CLC was measured fluorimetrically as intracellular cholesterol content in human THP-1-derived macrophages after incubation with patient serum. Oxidized LDL was measured as oxidized phospholipids on apoB100 particles (oxPL-apoB100). Anti-oxLDL, PCSK9 and C-reactive protein (CRP) were also quantified. Associations of oxPL-apoB100, anti-oxLDL IgG and PCSK9 with CLC were examined with multivariable linear regression. A two-stage dual moderated mediation model explored whether an indirect association of oxPL-apoB100 with CLC through parallel mediators anti-oxLDL IgG and PCSK9 varied as a function of moderators CRP and RF/ACPA positivity.

Results

OxPL-apoB100, anti-oxLDL IgG and PCSK9 positively associated with CLC (all adjusted p<0.020). In the final dual moderated mediation model oxPL-apoB100 was directly linked to CLC only in dual seropositive patients (unstandardized b [95% bootstrap confidence interval]=2.08 [0.38-3.79], Figure 1). An indirect effect of oxPL-apoB100 on CLC through anti-oxLDL IgG was present and increased along with level of CRP (index of moderated mediation=0.55 [0.05-1.17]). CRP also moderated the other indirect effect of oxPL-apoB100 on CLC through PCSK9, but only in dual seropositive patients (conditional indirect effect=0.64 [0.13-1.30]).

Conclusion

Oxidized LDL can directly influence CLC in dual seropositive RA patients, regardless of CRP. This suggests that targeting LDL oxidation in addition to inflammation may enable a more comprehensive reduction of atherosclerotic risk in these patients. Depending on CRP level, oxidized LDL also affected CLC indirectly via anti-oxLDL IgG and via PCSK9 in dual seropositive patients. If externally validated, our findings may have clinical implications for cardiovascular risk stratification and prevention.

References

[1]Voloshyna I et al. Plasma from rheumatoid arthritis patients promotes pro-atherogenic cholesterol transport gene expression in THP-1 human macrophages. Exp Biol Med (Maywood) 2013;238:1192–7.

Disclosure of Interests

George Karpouzas Speakers bureau: Sanofi-Genzyme-Regeneron, Janssen, Bristol-Meyer-Squibb, Consultant of: Sanofi-Genzyme-Regeneron, Janssen, Bristol-Meyer-Squibb, Grant/research support from: Pfizer, Bianca Papotti: None declared, Sarah Ormseth: None declared, Marcella Palumbo: None declared, Elizabeth Hernandez: None declared, Cinzia Marchi: None declared, Francesca Zimetti: None declared, Matthew Budoff Consultant of: Pfizer, Nicoletta Ronda: None declared

OP0136 SERUM CHOLESTEROL LOADING CAPACITY ON MACROPHAGES AND INTERACTIONS WITH TREATMENTS ON CORONARY ATHEROSCLEROSIS BURDEN AND EVENT RISK IN RHEUMATOID ARTHRITIS

Background

Cholesterol loading capacity (CLC) describes the ability of serum to deliver cholesterol to cells. It is linked to foam cell formation, a pivotal step in atherosclerotic plaque development. Rheumatoid arthritis (RA) serum promoted foam cell formation significantly more than control serum. Likewise, RA patients display greater plaque burden and higher-risk features than non-RA controls. bDMARDs and statins lower cardiovascular risk by reducing new coronary plaque formation, promoting regression, altering the composition and stabilizing prevalent atherosclerotic lesions.

Objectives

To evaluate the associations between CLC, coronary plaque burden and cardiovascular event risk in patients with RA. We further explored the conditioning effects of RA treatments on these relationships.

Methods

140 patients underwent coronary CT angiography for atherosclerosis evaluation and were prospectively followed for cardiovascular events over 6.0±2.4 years. Coronary artery calcium score (CAC), number of segments with plaque (segment involvement score [SIS]) and plaque composition were assessed. CLC was the macrophage cholesterol content, measured by fluorometric assay, after a 24-hour incubation with whole serum. Robust linear regression examined the effects of CLC and the interaction between CLC and bDMARD use on SIS and CAC. Negative binomial regression evaluated CLC and CLC × bDMARD interaction effects on number of high-risk (low-attenuation) plaques. With data discretized into 1-month intervals, weighted pooled logistic regression models with robust variance estimation evaluated CLC and time-varying bDMARD use as predictors of event risk, and the effect of CLC × time-varying bDMARD use on risk. Stabilized inverse probability of treatment and censoring weights were estimated as a function of ASCVD risk, SIS, RA duration, and baseline and time-varying CRP and statin use.

Results

Mean (SD) CLC was 12.67 (2.83) μg/mg protein. In analyses adjusting for ASCVD score, HDL, prednisone and statin use, CLC (per 1-SD unit) was not related to SIS (β -0.05 [95%CI -1.19,0.09]), number of high-risk plaques (rate ratio [RR] 1.20 [95%CI 0.80-1.80]) or ln-transformed CAC (β 0.017 [95%CI -0.133,0.147]). However, in analyses stratified by baseline bDMARD use, CLC (per 1-SD unit) was positively related to number of high-risk plaques (RR 2.14 [95%CI 1.04-4.40]) and ln-transformed CAC (β 0.21 [95%CI 0.01-0.41]) among bDMARD-naïve individuals (Figure 1). In addition, CLC inversely associated with SIS (per SD increment; β -0.16 [95%CI -0.32, -0.01]) only in bDMARD-treated patients. Baseline statin use did not significantly modify the effect of CLC on coronary plaque (not shown). CLC associated with cardiovascular event risk (per SD increment; adjusted odds ratio 2.02 [95%CI 1.27-3.50], p=0.011) covarying for ASCVD score and time-varying bDMARD use. The CLC × time-varying bDMARD use interaction also predicted event risk (p =0.010); current bDMARD use associated with lower event risk at higher (1 SD above the mean) CLC levels (p=0.037) but not average or lower (1 SD below the mean) CLC levels (p=0.064 and 0.756, respectively).

Conclusion

CLC associated with greater CAC score and high-risk plaque burden in bDMARD-naïve RA patients and lower total plaque burden in bDMARD-treated patients at baseline. CLC also predicted long-term cardiovascular risk and its effect was mitigated by bDMARD use.

Disclosure of Interests

George Karpouzas Speakers bureau: Sanofi-Genzyme-Regeneron, Janssen, Bristol-Meyer-Squibb, Consultant of: Sanofi-Genzyme-Regeneron, Janssen, Bristol-Meyer-Squibb, Grant/research support from: Pfizer, Bianca Papotti: None declared, Sarah Ormseth: None declared, Marcella Palumbo: None declared, Elizabeth Hernandez: None declared, Cinzia Marchi: None declared, Francesca Zimetti: None declared, Matthew Budoff Consultant of: Pfizer, Nicoletta Ronda: None declared

OP0137 ABDOMINAL OBESITY MAY CONFOUND THE ACCURACY OF CARDIOVASCULAR RISK PREDICTION IN RHEUMATOID ARTHRITIS; CAN CORONARY ATHEROSCLEROSIS IMAGING AND BIOMARKERS HELP?

Background

Accurate cardiovascular risk stratification is essential in rheumatoid arthritis (RA) care. RA patients who are underweight incur greater total and cardiovascular mortality compared to those who are overweight or obese.

Objectives

We explored whether abdominal obesity impaired the accuracy of risk prediction estimates in RA patients without known cardiovascular disease (CVD). We further interrogated the potential utility of coronary atherosclerosis assessment and serum levels of related cardiac damage biomarkers to optimize risk prediction in obese RA patients.

Methods

In a single center observational study, 150 participants with coronary CT angiography for atherosclerosis evaluation and prospective follow-up for cardiovascular events over 6.0±2.4 years were assessed. Framingham cardiovascular risk score was computed at baseline. Obesity was defined as waist circumference >88 cm in females and >102 cm in males. Segment involvement score (SIS) described the number of coronary segments with plaque. Serum highly-sensitive cardiac troponin I (hscTnI)-related both to coronary plaque burden and event risk in RA- was measured with Erenna immunoassay. Serum leptin, which is closely related to obesity, was measured with radioimmunoassay. CVD risk estimates were contrasted in non-obese vs. obese patients and those with low vs. high leptin correspondingly using area under the curve (AUC) comparisons. Improvements in risk estimate accuracy in obese patients were explored by sequentially adding hscTnI information and coronary plaque burden estimates to a baseline model of Framingham score and evaluating sequential change in AUC, net reclassification index (NRI) and integrated discrimination improvement (IDI).

Results

A significant interaction between Framingham cardiovascular risk score and obesity was observed (p=0.032). Lower estimates were seen in obese [AUC 0.660, 95%CI 0.487-0.832] vs. non-obese RA patients [AUC 0.952, 95%CI 0.897-1.007, p=0.002, Figure 1A]. Likewise, risk estimates were lower in patients with higher (>22.1 ng/ml) vs. lower (<22.1 ng/ml) leptin [AUC 0.618, 95%CI 0.393-0.842 vs. 0.874, 95%CI 0.772-0.976 respectively, p=0.042, Figure 1B]. In obese patients, sequential addition of the highest hscTnI tertile values and extensive atherosclerotic plaque presence (SIS>5) to a base model including Framingham risk score, significantly improved risk prediction estimates based on changes in NRI [1.093 95%CI 0.517-1.574], IDI [0.188, 95%CI 0.060-0.526], as well as AUC [0.179, 95%CI 0.058-0.378, p=0.02]. The final, combined model accurately predicted 83.9% of incident cardiovascular events (Figure 1C).

Figure 1.

A and B. Obesity attenuates accuracy of clinical cardiovascular risk estimates in RA. C. Addition of information from hs-cTnI measurements and coronary atherosclerosis assessment significantly improve risk prediction

Conclusion

Obesity significantly reduced cardiovascular risk estimate accuracy in patients with RA. The optimization of cardiac risk stratification with the help of non-invasive assessment of coronary atherosclerosis burden and related cardiac damage biomarkers in the serum may warrant further study.

Disclosure of Interests

George Karpouzas Speakers bureau: Sanofi-Genzyme-Regeneron, Janssen, Bristol-Meyer-Squibb, Consultant of: Sanofi-Genzyme-Regeneron, Janssen, Bristol-Meyer-Squibb, Grant/research support from: Pfizer, Sarah Ormseth: None declared, Elizabeth Hernandez: None declared, Matthew Budoff Consultant of: Pfizer

Abstract P5-08-09: Characterization of the Rac/Cdc42 inhibitor MBQ-168 as an anti-cancer compound

Metastasis continues to be the primary cause of cancer-related death in women with breast cancer, needing targeted therapies to inhibit this process. Therefore, we developed inhibitors targeting the homologous Rho GTPases Rac1 and Cdc42, which direct the actin cytoskeletal changes required for cell migration/invasion; and thus, metastasis. We characterized the potent inhibitor, MBQ-167 that blocks both Rac1 and Cdc42 at IC50s 103 nM and 78 nM, respectively, in human HER2 (+) and triple-negative breast cancer (TNBC) cells. Consequently, MBQ-167 inhibits tumor growth and metastasis by ~90% in pre-clinical mouse models of breast cancer (Humphries-Bickley, et al., 2017). To improve the activity and solubility of MBQ-167, we synthesized a panel of derivatives, maintaining the 9-ethyl-3-(1H-1,2,3-triazol-1-yl)-9H-carbazole as the core for each derivative. Of the derivatives tested, MBQ-168 demonstrated improved solubility and comparable efficacy. Similar to MBQ-167, MBQ-168 induced actin cytoskeletal disintegration, cell rounding, and detachment to ultimately undergo anoikis. In 120hrs, MBQ-168 significantly inhibited the viability of MDA-MB-231 at a GI50 of 228nM and HER2+ MDA-MB-435 cells with a GI50 of 137 nM, without affecting the viability of Human Mammary Epithelial Cells (HMEC). In apoptosis assays, MBQ-168 treatment, at 500nM for 48 hrs, demonstrated a similar response to MBQ-167 by &gt;4-fold increase in Caspase 3/7 activity in HER2 (+), and MDA-MB-231 and MDA-MB-468 TNBC cells. In wound healing assays, MBQ-168 also responded similar to MBQ-167 by a ~80% inhibition of breast cancer cell migration at 250nM and 500nM for 24hrs. Moreover, as quantified from Rac1.GTP pulldown assays, following 250nM treatment for 24hrs, MBQ-168 inhibited Rac1 activation in the attached cell population by ~70%, and in the detached cell population by ~100%, demonstrating a potent inhibition of Rac1 activation. In a preliminary study for relative efficacy in mice, MBQ-168 significantly reduced HER2+ MDA-MB-435 mammary tumor growth (~90%) at 5mg/kg BW via IP administration. In conclusion, MBQ-168 is an effective Rac inhibitor that reduces breast cancer cell viability, induces apoptosis, and inhibits breast cancer cell migration, actin cytoskeletal extensions, and Rac1 activation to result in a drastic reduction in mammary tumor growth in mice. We predict that the increased solubility of MBQ-168 will make it more bioavailable than MBQ-167. Thus, we have demonstrated that small structural modifications of MBQ-167 can affect the cytotoxic activity of carbazole derivatives with potential as anti-cancer drugs, and as tools to block Rac/Cdc42 activities in biological systems.

Citation Format: Julia Medina, Tatiana Matos, Luis Velazquez, Michael Rivera, Ailed Cruz-Collazo, Eliud Hernandez, Cornelis Vlaar, Suranganie Dharmawardhane. Characterization of the Rac/Cdc42 inhibitor MBQ-168 as an anti-cancer compound [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr P5-08-09.

Influence of the speed of deflation of the stent delivery system in the myocardial blush and ST-segment resolution in primary angioplasty: a randomized study

Introduction

Distal embolization may compromise the results of primary angioplasty. Our aim is to analyze the influence of the speed of deflation of the stent delivery system on the myocardial blush ≥2 and on the ST-Segment resolution ≥70%.

Methods

From December 2016 to February 2019, all consecutive patients with ST-elevation myocardial infarction who underwent urgent coronary angiography at our institution who were susceptible of thrombectomy, IIB-IIIA inhibitors and direct stenting were randomized 1:1 to fast deflation of the stent delivery system (group 1, n=103) or to slow deflation at 1 atm/second (group 2, n=107). Pre- and postdilatation was not allowed per protocol. The primary outcomes were the myocardial blush ≥2 and the ST-Segment resolution ≥70% while the size of myocardial damage, ejection fraction at discharge and at 12 months and total and cardiovascular mortality at 12 months were the secondary outcomes. A multivariate analysis was performed to analyze the influence of the speed of deflation of the stent delivery system in both primary end-points in case of possible imbalances among groups despite the randomization.

Results

Both groups represented 47% of the 447 procedures of primary angioplasty performed in that period. Baseline characteristics of the whole cohort: female gender 46 (21.9%), age 59.5±10.6 years, diabetes 35 (16.7%), Killip class IV 5 (2.4%), total ischemic time 177.5 (124–275) minutes and door to balloon time 84 (66–120.5) minutes. There were not differences in clinical or angiographic characteristics between both groups, although there was a non-significant trend towards larger reference vessel diameter in the slow deflation group (2.74±0.42 vs. 2.86±0.47, p=0.07). The study was prematurely stopped with 50% of the calculated sample size due to futility. The primary endpoint of myocardial blush ≥2 occurred in 77 (74.7%) vs. 79 (75.2%), p=0.93 and ST-Segment resolution ≥70% in 54 (53.9%) vs. 59 (55.5%), p=0.75 in group 1 and 2, respectively, without differences in any of the secondary endpoints. The speed of deflation of the stent delivery system did not show any influence on the MB or ST-Segment resolution ≥70% in the multivariate analysis. Predictors of myocardial blush ≥2 were systolic blood pressure at admission, creatinine clearance &lt;60 ml/min and maximal diameter postprocedure. Diabetes, previous infarction, left anterior descending, TIMI ≥2 before intervention, TIMI 3 after intervention and collateral supply grade ≥2 were predictors of ST segment resolution≥70% with an area under the curve of 0.71 (0.63–0.80) and 0.75 (0.68–0.82), respectively.

Conclusions

In our series, the speed of deflation of the stent delivery system in primary angioplasty did not modified the myocardial blush ≥2 or ST-Segment resolution ≥70% and neither showed any influence in clinical outcomes, size of myocardial infarction by biomarkers and ejection fraction.

Funding Acknowledgement

Type of funding sources: Private grant(s) and/or Sponsorship. Main funding source(s): Abbott Laboratories

POS0215 DIRECT AND CONDITIONAL EFFECTS OF EPICARDIAL ADIPOSE TISSUE VOLUME ON CORONARY PLAQUE PROGRESSION IN RHEUMATOID ARTHRITIS

Background:

Epicardial adipose tissue volume (EATv) predicts coronary atherosclerosis presence, progression and cardiovascular event risk in general patients1,2. Our group recently reported that EATv associated with greater subclinical coronary plaque burden, non-calcified plaque presence and vulnerable plaque characteristics in patients with rheumatoid arthritis (RA). The relationship was stronger in RA patients with lower disease duration, no traditional cardiac risk factors, and who were not obese.

Objectives:

To evaluate the predictive value of EATv on long-term coronary atherosclerosis development, and moderators of the association between EATv and plaque formation.

Methods:

This single-center observational cohort study included 100 patients without symptoms or diagnosis of cardiovascular disease who underwent computed tomography angiography for evaluation of EATv and coronary atherosclerosis at baseline and repeat assessments 6.9±0.3 years later to evaluate plaque progression. New plaque formation in segments without plaque at baseline was the main outcome. Robust multivariable logistic regression evaluated the effect of high versus low EATv (based on median) on likelihood of new plaque formation, accounting for clustering of segments within patients. Potential moderator effects of prespecified predictors were also assessed.

Results:

High EATv (>107 cm3) predicted new plaque formation in segments without baseline plaque (OR 2.77 [95% CI 1.43-5.37], p= 0.003); however, significance was lost in the multivariable model. Importantly, high EATv associated with formation of higher-risk non- and partially calcified plaque after adjusting for Framingham D’Agostino risk score, obesity, segment location, time-averaged CRP, duration of bDMARD and statin treatment and cumulative prednisone dose (adjusted OR 2.57 [95% CI 1.02-6.48], p= 0.045). RA duration (<10 versus >10 years), cardiac risk factor burden (≤1 versus >1), presence of mixed/calcified plaque in other coronary segments at baseline, and statin exposure (≤1 versus >1 year, based on median) moderated the effect of EATv on all new plaque formation (all p for interaction ≤ 0.021). Specifically, high EATv predicted new plaque formation in patients with RA duration <10 years (adjusted OR 5.75 [95% CI 1.77-18.67]), those with ≤1 cardiac risk factors (adjusted OR 3.40 [95% CI 1.46-7.90]), those without calcification at baseline (adjusted OR 2.65 [95% CI 1.11-6.31]) and those with statin treatment <1 year (adjusted OR 3.33 [95% CI 1.13-9.77]). This was not the case for patients with RA >10 years, ≥ 2 cardiac risk factors, calcification at baseline and statin treatment >1 year (figure 1).

Conclusion:

High baseline EATv independently predicted future higher-risk non-calcified and mixed coronary plaque in RA. Moreover, it conditionally promoted new plaque formation overall in patients with earlier disease, low cardiac risk factor burden, who had little or no atherosclerosis at baseline and who had limited exposure to statin therapy. These findings indicate the need for a larger prospective evaluation of the role of EATv as a biomarker of coronary atherosclerosis development in RA.

References:

[1]Hwang I-C et al. J Atheroscler Thromb 2017;24:262–74. 2. Ding J et al. Am J Clin Nutr 2009;90:499–504.

Figure 1.

Moderators of influence of EATv on new coronary plaque formation

Disclosure of Interests:

George Karpouzas Speakers bureau: Sanofi/ Genzyme/ Regeneron, Consultant of: Sanofi/ Genzyme/ Regeneron, Grant/research support from: Pfizer, Sarah Ormseth: None declared, Elizabeth Hernandez: None declared, Matthew Budoff Consultant of: Pfizer

OP0104 DIFFERENCES IN LOW-DENSITY LIPOPROTEIN (LDL) PARTICLE COMPOSITION AND OXIDATION MAY UNDERLIE THE PARADOXICAL ASSOCIATION OF LOW LDL WITH HIGHER CORONARY ATHEROSCLEROSIS BURDEN IN RHEUMATOID ARTHRITIS

Background:

The association between cholesterol and cardiovascular disease (CVD) risk is attenuated in Rheumatoid arthritis (RA). In fact, RA patients in the lowest low-density lipoprotein (LDL) group (<70mg/dl) may experience unexpectedly high CVD risk.

Objectives:

We here explored whether patients with LDL<70mg/dl (Group 1) had higher coronary atherosclerosis burden compared to other LDL groups (Group 2: 70≤LDL≤130 and Group 3: LDL>130), as a reason for this risk. We further evaluated whether low LDL in group 1 associated with differences in inflammation, LDL particle composition or oxidation.

Methods:

One hundred fifty RA patients without symptoms or history of CVD underwent coronary atherosclerosis evaluation with computed tomography angiography. Coronary artery calcium (CAC), number of segments with plaque (segment involvement score), stenotic severity (segment stenosis score), and extensive (>4 segments with plaque) or obstructive disease (>50% stenosis) were assessed. Lipoprotein classes and subclasses were directly measured. Oxidized LDL (oxLDL) was measured with monoclonal antibody E06. Chemiluminescence Elisa quantified IgG and IgM antibodies to oxLDL (anti-oxLDL) and apoB100 immune complexes (IC). Proinflammatory cytokines were measured with Erenna Immunoassay. Robust linear and logistic regression models- adjusted for Framingham D’Agostino score, obesity, disease activity, bDMARD and statin treatment- evaluated associations between LDL groups and plaque outcomes. Similar models evaluated adjusted differences in LDL subclasses, oxLDL, anti-oxLDL, anti-ApoB100 IC, and cytokines across LDL groups.

Results:

Group 1 patients had higher coronary plaque burden (Figure 1A) and 2.8 times greater risk of extensive or obstructive disease (adjusted OR 2.82 [95% CI 1.12-7.17], P = 0.031) compared to LDL>70 groups. Among statin naïve patients, those with LDL<70 also had higher oxLDL (log-transformed adjusted mean 2.55 [95% CI 2.34-2.77] versus 2.27 [95% CI 2.19-2.36], P = 0.018 for LDL>70). Notably, Group 1 patients also had higher anti-oxLDL IgG and anti-ApoB100 IgG IC levels compared to other groups (Figure 1B). LDL subclass relative content in the LDL particle differed across groups (Figure 1C). Lp(a) was higher in LDL particles in Group 1 (adjusted mean 16.04% [95% CI 11.75-20.33], versus 10.48% [95% CI 8.20-12.75] in Group 2, P = 0.026 and 7.41% [95% CI 0.77-14.04] in Group 3, P = 0.033). Notably, Lp(a) content strongly associated with oxLDL overall (r = 0.83, P < 0.0001). This association was stronger for Group 1 compared to others (P < 0.005, Figure 1D). No differences in RA activity, CRP, TNF-α, IL-17A, or IL-17F were seen across groups. However, Group 1 had higher IL-6 (log-transformed adjusted mean 1.98 [95% CI 1.64- 2.32] versus 1.57 [95% CI 1.45-1.70], P = 0.028 in Group 2 and 1.32 [95% CI 0.84-1.80], P = 0.031 in Group 3). IL-6 associated with both IgG anti-oxLDL (P = 0.015) and anti-apoB100 IC (P = 0.016). Log-transformed IL-6 further associated with higher log-transformed CAC (adjusted B 0.41 [95% CI 0.01-0.81], P = 0.049).

Conclusion:

RA patients with LDL<70 mg/dl had higher coronary atherosclerosis burden. Low circulating LDL in that group may reflect higher oxidation; this was mostly linked to the larger Lp(a) relative content of LDL and its significantly higher oxidation potential in that group. OxLDL immune recognition was linked to higher IgG anti-oxLDL Ab and anti-ApoB100 IC levels in the LDL<70 group, which further associated with higher IL-6 elaboration and atherosclerosis burden.

Disclosure of Interests:

George Karpouzas Speakers bureau: Sanofi/ Genzyme/ Regeneron, Consultant of: Sanofi/ Genzyme/ Regeneron, Grant/research support from: Pfizer, Sarah Ormseth: None declared, Elizabeth Hernandez: None declared, Matthew Budoff Consultant of: Pfizer

POS0216 GREATER HIGH-DENSITY LIPOPROTEIN LEVELS OVER TIME ARE LINKED TO DECREASED CORONARY PLAQUE FORMATION AND REGRESSION AND STABILIZATION OF HIGH-RISK LESIONS IN RHEUMATOID ARTHRITIS

Background:

The relationship between serum lipoproteins and cardiovascular disease risk in rheumatoid arthritis (RA) is complex1. Their levels and function may vary based on disease activity and medication use. Beneficial effects on high-density lipoprotein (HDL-C) levels, structure and behavior, in response to treatment have been described. However, the impact of HDL-C levels over time on coronary atherosclerosis progression in RA is unknown.

Objectives:

We here evaluated the influence of HDL-C levels over time on long-term coronary plaque formation and progression in patients with RA.

Methods:

One hundred one RA patients without symptoms or history of cardiovascular disease who participated in a computed tomography angiography study of coronary atherosclerosis had repeat assessments after 6.9±0.3 years to evaluate plaque progression. Clinical, laboratory and medication data were recorded at baseline and regular outpatient follow-up visits thereafter. Time-averaged HDL-C was calculated for each patient using available consecutive HDL measurements between baseline and follow-up. Robust logistic regression assessed the association between time-averaged HDL-C and likelihood of new plaque formation in segments without plaque at baseline, and transition of prevalent mixed plaque to calcified plaque. Robust multinomial logistic regression evaluated the effect of time-averaged HDL-C on likelihood of new non-calcified, mixed or calcified plaque formation in segments without plaque (compared to remaining without plaque), and non-calcified plaque regression or transition to mixed or calcified plaque at follow-up (compared to remaining non-calcified). All models accounted for clustering of coronary segments within patients and adjusted for Framingham D’Agostino risk score, proximal segment location, time-averaged CRP, cumulative prednisone dose, bDMARD duration, statin duration, waist-to-height ratio, and time-averaged triglycerides.

Results:

Participants were mostly female (n=87, 86.1%), with a mean ± standard deviation (SD) age of 51.5±10.3 years and time-averaged HDL-C of 51.7±13.9. Ninety-seven new plaques formed in segments without plaque at baseline; 20 were noncalcified, 21 were mixed, and 56 were calcified. Time-averaged HDL-C had no effect on new total plaque formation (adjusted odds ratio-OR 0.88 [95% CI 0.64-1.21]). However, each 1-SD increase in time-averaged HDL-C associated with a 44% reduced likelihood of new non-calcified plaque formation at follow-up (adjusted OR 0.56 [95% CI 0.35-0.92], Figure 1). In contrast, there was no effect of time-averaged HDL-C on new mixed or calcified plaque formation. Of 98 non-calcified plaques at baseline, 42 did not change at follow-up, 32 regressed (disappeared), 16 transitioned to mixed and 8 to calcified plaques. Each SD increase in time-averaged HDL-C yielded a 2.2-fold greater likelihood of non-calcified plaque regression (adjusted OR 2.21 [95% CI 1.02-4.83]). Sixteen of 52 mixed plaques present at baseline transitioned to more stable calcified lesions, and time-averaged HDL-C (per 1-SD increment) predicted a 3.5-fold increased likelihood of transition of mixed to fully calcified plaque (adjusted OR 3.56 [95% CI 1.25-10.17]).

Conclusion:

Higher HDL-C over time predicted regression of existing and decreased formation of new higher-risk non-calcified plaque. It also associated with transition of vulnerable mixed plaque to more stable fully calcified plaque. These effects were independent of RA treatment duration, prednisone dose and statin exposure.

References:

[1]Toms TE et al. Curr Vasc Pharmacol. 2010;8:301–326.

Figure 1.

Impact of HDL-C over time on coronary plaque progression in RA

Disclosure of Interests:

George Karpouzas Speakers bureau: Sanofi/Genzyme/Regeneron, Consultant of: Sanofi/Genzyme/Regeneron, Grant/research support from: Pfizer, Sarah Ormseth: None declared, Elizabeth Hernandez: None declared, Matthew Budoff: None declared

POS0571 NON-OBESE RHEUMATOID ARTHRITIS PATIENTS WITH LOW LOW-DENSITY LIPOPROTEIN HAVE GREATER CORONARY ATHEROSCLEROSIS BURDEN, PLAQUE PROGRESSION AND CARDIOVASCULAR EVENT RISK

Background:

Rheumatoid arthritis (RA) patients with low body weight incur higher mortality than obese patients. Paradoxically, RA patients in the lowest low-density lipoprotein group (LDL <70 mg/dl) may also experience higher cardiovascular disease (CVD) risk.

Objectives:

We here explored whether abdominal obesity (waist-to-height ratio >0.58 in females and >0.63 in males) might moderate the effect of low LDL (<70mg/dl) on coronary atherosclerosis burden, progression and long-term CVD risk in RA.

Methods:

One hundred fifty patients without symptoms or diagnosis of CVD underwent coronary computed tomography angiography. Plaque progression was evaluated 6.9±0.3 years later in 101 patients. Coronary artery calcium, number of segments with plaque (segment involvement score), and extensive (>4 segments with plaque) or obstructive disease (>50% stenosis) were assessed. CVD events were prospectively recorded, including cardiac death, myocardial infarction, unstable angina, revascularization, stroke, claudication, and heart failure hospitalization over 6.0±2.4 years of follow-up. Lipoprotein classes were directly measured. Oxidized LDL (oxLDL) was assessed with monoclonal antibody E06. Adjusted robust linear regression evaluated interactions between abdominal obesity and LDL groups on plaque outcomes. Per segment, adjusted robust logistic regression models explored obesity x LDL group interactions on new plaque formation and stenotic progression of prevalent plaques. Robust Cox regression models stratified by abdominal obesity evaluated the effect of LDL group (<70 vs. >70 mg/dl) on CVD events.

Results:

Non-obese patients with low LDL had the highest plaque burden (Figure 1A, all p < 0.02). Obesity moderated the effect of LDL on likelihood of extensive/obstructive disease (P for interaction = 0.061); specifically, LDL<70 associated with an increased likelihood of extensive/obstructive plaque in non-obese (adjusted OR 4.75 [95% CI 1.18-19.07], P = 0.028) but not obese patients (adjusted OR 1.55 [95% CI 0.39-6.08], P = 0.532). No differences in disease activity or inflammatory markers were seen across groups. Compared to LDL>70 mg/dl, low LDL predicted an increased likelihood of high oxLDL (>median) in non-obese patients (adjusted OR 5.10 [95% CI 1.46-17.75], P = 0.011) but not obese patients (adjusted OR 0.50 [95% CI 0.11-2.21], P = 0.36, Figure 1B). Obesity further moderated the effect of LDL on likelihood of future development of plaque (P for interaction = 0.002) and increased stenotic severity of existing plaques (P for interaction = 0.040); in non-obese patients, low LDL associated with a greater likelihood of new plaque forming in segments without baseline plaque (adjusted OR 4.68 [95% CI 2.26-9.66]) and worsening stenotic severity in segments with prevalent plaque (OR 5.35 [95% CI 1.62-17.67]). This was not observed in obese patients (Figure 1C). Notably, in non-obese patients, low LDL associated with higher CVD event risk compared to those with LDL>70 mg/dl (HR 7.94 [95% CI 1.52-41.36], P = 0.015). This was not the case in obese patients (HR 0.32 [95% CI 0.04-2.40], P = 0.27, Figure 1D).

Conclusion:

In non-obese RA patients, LDL<70 mg/dl may reflect higher LDL oxidation and was associated with higher baseline coronary atherosclerosis burden, new plaque formation, stenotic plaque progression and greater CVD risk than LDL>70 mg/dl.

Disclosure of Interests:

George Karpouzas Speakers bureau: Sanofi/ Genzyme/ Regeneron, Consultant of: Sanofi/ Genzyme/ Regeneron, Grant/research support from: Pfizer, Sarah Ormseth: None declared, Elizabeth Hernandez: None declared, Matthew Budoff Consultant of: Pfizer

Persistent Barriers to Smoking Cessation Among Urban, Underserved Women: A Feasibility Study of Tailored Barriers Text Messages

OBJECTIVES

Despite health risks for themselves and their children, urban underserved women smoke at high rates postpartum. The postpartum period is a stressful transition time that presents unique barriers to sustained cessation. There is limited extant evidence of efficacious psychosocial programs to maintain postpartum smoking cessation.

METHODS

Guided by the Cognitive-Social Health Information Processing model, we explored the feasibility of TxT2Commit, a text-messaging intervention designed to prevent postpartum smoking relapse. Participants (n = 43) received supportive cessation-focused text messages for one month postpartum. Using a convergent mixed method design, surveys and interviews assessed changes in psychosocial factors and smoking status through a three month follow-up.

RESULTS

Participants reported satisfaction with TxT2Commit, rating text messages as helpful, understandable, supportive, and not bothersome. However, a majority of women (n = 28, 65.1%) relapsed by three months. Participants who stayed smoke free (i.e., non-relapsers) reported significantly less temptation to smoke at one and three months postpartum compared to relapsers (ps < .01). While relapsers had significantly less temptation at one month compared to baseline, temptation increased by three months (p < .01). Consistent with the quantitative results, qualitative interviews identified informational and coping needs, with continued temptation throughout the three months. Non-relapsers were able to manage temptation and reported greater support.

CONCLUSIONS FOR PRACTICE

TxT2Commit demonstrates preliminary feasibility and acceptability among urban, underserved postpartum women. However, most participants relapsed by three months postpartum. Additional research is needed to identify targeted messaging to best help women avoid temptation and bolster support to stay smoke free in this uniquely stressful period.

Abstract 4018: Interaction site elucidation of the Rac1/Cdc42 inhibitor, MBQ-167

Metastasis continues to be the primary cause of cancer-related death. Therefore, we focus on designing small molecules inhibitors to block metastasis. The Rho GTPase family members Rac1, and Cdc42 are critical regulators of cancer cell migration and invasion, and thus, metastasis. Rac1 is activated by Guanine Nucleotide Exchange Factors (GEFs), which promote the exchange of GDP to GTP. In most cancers, the homologous Rac1 and Cdc42 are hyperactivated due to the overexpression of GEFs. Therefore, we designed inhibitors to block the activation and interaction of Rac1 and Cdc42 with their GEFs. Our lead compound MBQ-167, is a dual inhibitor of Rac1 and Cdc42 with IC50s of 103 nM and 78 nM, respectively. MBQ-167 inhibited the viability and migration of metastatic cancer cells without affecting non-metastatic or non-cancer cells. Moreover, MBQ-167 reduced mammary tumor growth and metastasis of HER2 positive and triple-negative breast cancer cells in immunocompromised mice by ~ 90%. To further elucidate the mechanism of action of MBQ-167, we tested the hypothesis that MBQ-167 blocks the interaction of specific Rac1/Cdc42 GEFs by interaction with particular amino acid residues in the switch I and II homologous regions of Rac1 and Cdc42 proteins. Therefore, to achieve the objective of elucidating the interaction site of MBQ-167 on Rac1 and Cdc42, we used in silico analysis and Nuclear Magnetic Resonance (NMR) of MBQ-167 with Rac1 in a GDP bound state. These results were biochemically validated by pulldown assays using a G15A nucleotide-free mutant predicted to interact tightly with Rac1/Cdc42 GEFs. In silico, using Autodock Tools, MBQ-167 was docked to the GEF binding domain of Rac1 and Cdc42 with low binding energy, indicating a tight interaction. For the NMR structural analyses, Rac1 was isotopically labeled with 15N and titrated with several concentrations of MBQ-167, at ratios of 1:1, 1:2, 1:3, and 1:4. We were able to detect chemical shift perturbations in key residues in the switch I and II regions that interact with Rac1/Cdc42 GEFs and regulate the activity. Moreover, these perturbations were more intense with increasing amounts of MBQ-167, confirming the specificity of the interaction. Therefore, our data signify the direct interaction of MBQ-167 with Rac1, thus validating the role of MBQ-167 as a specific Rac1/Cdc42 inhibitor.

Citation Format: Julia I. Medina, Marvin Bayro, Eliud Hernandez, Cornelis Vlaar, Ricardo Gonzalez, Suranganie Dharmawardhane. Interaction site elucidation of the Rac1/Cdc42 inhibitor, MBQ-167 [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 4018.

High-resolution adaptive interferometer with dynamic population grating recorded at 1064 nm in ytterbium-doped fiber

An adaptive optical fiber sensor/demodulator of an optical phase modulation with a Sagnac interferometer configuration is reported. The dynamic population grating recorded in ytterbium-doped fiber (YDF) at a wavelength of 1064 nm enables adaptive properties of this configuration with a high-pass transfer function and with the cut-off frequency of about 260 Hz at ∼10mW cw recording power. A linear response with nearly 100% modulation depth is ensured by effective formation of the nonshifted phase dynamic grating with the amplitude one order of magnitude greater than can be expected from the saturation of the YDF absorption at the recording wavelength. This is associated with the photoinduced changes in the UV optical absorption of the YDF and enables minimal detected amplitude of the phase modulation ≈0.7∗10^-7Hz in our experimental configuration. We believe that, in general, this mechanism of the phase grating formation can ensure the sensor resolution limited by the photonic noise of the utilized light power only.

THU0530 HIGHLY-SENSITIVE CARDIAC TROPONIN I AND BETA-2-GLYCOPROTEIN-I IGA ANTIBODIES INFORM THE UTILITY OF SCREENING AND FOLLOW-UP NON-INVASIVE CORONARY ATHEROSCLEROSIS EVALUATION AND OPTIMIZE CARDIOVASCULAR RISK ASSESSMENT IN RHEUMATOID ARTHRITIS

Background:

Occult coronary atherosclerosis burden predicts mid-term cardiovascular disease (CVD) events in rheumatoid arthritis (RA) above and beyond Framingham D’Agostino cardiac risk score (FRS-DA). Highly-sensitive cardiac troponin I (hs-cTnI) levels in blood associate with coronary plaque burden and event risk in RA. Moreover, IgA antibodies against beta2-glycoprotein-1 (a-b2GPI-IgA)- an atherosclerotic plaque antigen- in RA promote coronary plaque progression and moderate the effect of inflammation on CVD events. It is currently unclear when to recommend a screening, non-invasive coronary atherosclerosis evaluation in asymptomatic RA patients and whether such an assessment should be repeated.

Objectives:

To explore whether either biomarker alone or their combination improved prediction of plaque presence on an initial coronary CT angiogram (CCTA) beyond FRS-DA score; to evaluate whether either biomarker predicted progression to extensive or obstructive plaque on a follow-up evaluation.

Methods:

One hundred fifty RA patients underwent a baseline CCTA; 101 had repeat evaluation within 6.9±0.3 years. Hs-cTnI and a-b2GPI-IgA were assessed at baseline; the latter were confirmed 12 weeks later, if positive. Lesions rendering greater than 50% luminal stenosis were considered obstructive. Extensive plaque was defined as >5 coronary segments with plaque, or stenosis score>5, or coronary artery calcium score (CAC)>100. The diagnostic accuracy of FRS-DA alone vs. with hs-cTnI or a-b2GPI-IgA individually or combined for plaque or CAC at baseline was evaluated as area under the curve (AUC). Improvement in prediction accuracy between constructs was further assessed as integrated discrimination improvement (IDI). Similar AUC and IDI constructs evaluated the transition to obstructive or extensive atherosclerosis at follow-up in patients with baseline non-extensive or non-obstructive disease.

Results:

High hs-cTnI (>1.5pg/ml) added to FRS-DA increased AUC from 0.717 to 0.731 (Figure 1A) and improved prediction accuracy for baseline plaque [IDI=0.041 (SE)=0.017, p=0.015]. In contrast, a-b2GPI-IgA did not [IDI=0.005 (0.006), p=0.47] and the combination offered no added benefit to the hs-cTnI model alone. Similar observations were made for CAC. Presence of a-b2GPI-IgA independently associated with coronary plaque progression (IRR=1.67 [95%CI 1.04-2.67]), whereas hs-cTnI did not. Likewise, a-b2GPI-IgA associated with transition to extensive or obstructive disease independently of FRS-DA (OR=13.48 [95%CI 2.09-86.99]). Notably, 71.4% of a-b2GPI-IgA positive patients with high hs-cTnI progressed to extensive or obstructive disease compared to 7.7% of a-b2GPI-IgA negative subjects with high hs-cTnI (p=0.008). Addition of a-b2GPI-IgA to FRS-DA in patients with prevalent non-extensive non-obstructive plaque increased AUC from 0.785 to 0.900 (Figure 1B) and significantly improved the prediction for development of obstructive or extensive atherosclerosis at follow-up [0.387, (0.13), p=0.003].

Figure 1.

(A) Diagnostic accuracy for prediction of occult coronary atherosclerosis at baseline. FRS-DA alone is the base model followed by addition of hs-cTnI or a-b2GPI-IgA individually or combined.(B) Diagnostic accuracy for progression from non-obstructive and non-extensive plaque at baseline to obstructive or extensive atherosclerosis at follow-up.

Conclusion:

High hs-cTnI improved the risk of baseline plaque presence beyond clinical risk score and may trigger an initial non-invasive coronary atherosclerosis evaluation. A-b2GPI-IgA presence may justify a follow-up evaluation in patients with non-extensive, non-obstructive plaque at baseline.

Disclosure of Interests:

George Karpouzas Grant/research support from: Pfizer, Consultant of: Sanofi-Genzyme-Regeneron, Janssen, Speakers bureau: Sanofi-Genzyme-Regeneron, BMS, Sarah Ormseth: None declared, Elizabeth Hernandez: None declared, Matthew Budoff: None declared

OP0120 BIOLOGICS MAY PREVENT CARDIOVASCULAR EVENTS IN RHEUMATOID ARTHRITIS BY INHIBITING CORONARY PLAQUE FORMATION AND STABILIZING HIGH-RISK LESIONS

Background:

Biologic disease-modifying antirheumatic drugs (bDMARDs) effectively control inflammation and may improve cardiovascular outcomes in Rheumatoid arthritis.

Objectives:

To evaluate if bDMARDs decrease long-term cardiovascular disease (CVD) risk in rheumatoid arthritis and whether potential benefits might be rendered by impacting coronary plaque formation or progression.

Methods:

In this single-center observational cohort study, 150 patients underwent computed tomography angiography for evaluation of coronary atherosclerosis (total, non-calcified, mixed/calcified and low-attenuation or high-risk plaque); 101 had repeat assessments within 6.9±0.3 years to evaluate plaque progression. All CVD events were prospectively recorded, including cardiac death, myocardial infarction, unstable angina, revascularization, stroke, claudication, and heart failure hospitalization. The Framingham-D’Agostino score assessed clinical risk. Segment stenosis score (cumulative stenosis) measured plaque burden. The effect of bDMARD treatment on CVD events was assessed using marginal structural models. The inverse probability of treatment and censoring weights were used in a weighted pooled logistic regression with current bDMARD use and time since study entry included in the model to approximate a Cox proportional hazards model allowing for time-varying weights. Robust logistic regression evaluated the effect of bDMARD exposure (>50 percent of follow-up period) on likelihood of new plaque formation or change in plaque composition in per-segment models adjusted for Framingham-D’Agostino score, time between scans, statin duration, cumulative prednisone dose and time-averaged CRP.

Results:

Sixteen patients incurred 19 CVD events. Current bDMARD use associated with lower CVD risk (OR=0.20 [95%CI=0.05-0.75], p=0.018, Figure 1). However, the effect of bDMARDs was no longer significant when a 6-month exposure extension was applied (OR=0.42 [95% CI 0.13-1.38], p=0.15). The effect of bDMARD use on CVD risk was moderated by non-calcified plaque and low-attenuation plaque presence (Figure 1); specifically, bDMARDs were associated with lower CVD risk only in patients with non-calcified plaque (p=.048) or low-attenuation plaque (p=0.036) at baseline. Per-segment plaque progression analyses showed no main effect of bDMARD exposure on likelihood of new plaque formation (Figure 2). However, bDMARD exposure predicted lower likelihood of new plaque forming in segments without plaque among patients without mixed/calcified plaque in other coronary segments (OR=0.40 [95%CI=0.17-0.93]), but not among those with mixed/calcified plaque elsewhere in their arteries (OR=1.60 [95%CI=0.71-3.62]). Moreover, transition of non-calcified to mixed/calcified plaque associated with bDMARD exposure (OR=4.00 [95%CI=1.05-15.32]). bDMARD use also predicted low-attenuation plaque loss (p=0.042).

Figure 1.

Effect of bDMARD use on cardiovascular disease risk stratified by coronary plaque presence

Figure 2.

Effect of bDMARD exposure on plaque formation and transition from baseline to follow-up

Conclusion:

In rheumatoid arthritis, bDMARD use associated with reduced long-term CVD risk, lower likelihood of new plaque formation in patients with early atherosclerosis, stabilization of high-risk plaque and protective calcification of non-calcified lesions.

Disclosure of Interests:

George Karpouzas Grant/research support from: Pfizer, Consultant of: Sanofi-Genzyme-Regeneron, Janssen, Speakers bureau: Sanofi-Genzyme-Regeneron, BMS, Sarah Ormseth: None declared, Elizabeth Hernandez: None declared, Matthew Budoff: None declared

FRI0066 SUBCLINICAL CORONARY CALCIFICATION ASSOCIATED WITH LONG-TERM CARDIOVASCULAR OUTCOMES IN RHEUMATOID ARTHRITIS

Background:

Large, multicenter studies established the strong prognostic value of coronary artery calcium (CAC) scoring in asymptomatic individuals. Increasing CAC score is an independent predictor of worsening cardiovascular disease event risk in general patients. The prognostic significance of higher CAC score strata in the long-term cardiovascular risk in rheumatoid arthritis (RA) is unknown.

Objectives:

To evaluate the long-term cardiovascular event risk across CAC strata in a prospective, single center cohort of established RA patients without symptoms or prior diagnosis of cardiovascular disease.

Methods:

One hundred-fifty patients underwent computed tomography angiography for coronary atherosclerosis evaluation. CAC score was measured according to Agatston. CVD events were prospectively recorded, including cardiac death, myocardial infarction, unstable angina, revascularization, stroke, claudication, and heart failure hospitalization over 6.0±2.4 years of follow-up. Unadjusted, robust Cox proportional hazards regression models evaluated CVD event risk across higher CAC strata (CAC=1-99, CAC=100-399 and CAC≥400) compared to CAC=0. Additional multivariable robust Cox regression models with time-varying covariates evaluated the impact of log transformed CAC or different CAC thresholds (CAC>0 vs. CAC=0, CAC≥100 vs. CAC<100 and CAC≥400 vs. CAC<400) on future CVD events. Models were controlled for Framingham-D’Agostino clinical risk score, time-varying current bDMARD use and time-varying CRP.

Results:

Sixteen patients incurred 19 events, for a total of 2.1 (95% CI 1.3-3.3) events/100 patient-years. Increasing HR for cardiovascular events was observed for ascending CAC strata; 3.87 (1.03-14.48), 6.31 (1.38-28.91) and 16.98 (4.50-64.10) for CAC=1-99, CAC=100-399 and CAC≥400 respectively compared to CAC=0 (figure 1). In fully adjusted models, CAC score associated with future event risk independently of Framingham D’Agostino score, time-varying bDMARD use and time-varying CRP (HR=1.31 [95%CI 1.04-1.66]). CAC thresholds ≥100 (vs. <100) and CAC≥400 (vs. <400) in fully adjusted models similarly constituted independent predictors of long-term cardiovascular events (Figure 2).

Figure 1.

Increasing CAC scores associated with higher cardiovascular event risk in RA

Figure 2.

Impact of different CAC thresholds on cardiovascular event risk in RA

Conclusion:

Increasing CAC scores are strong, independent predictors of long-term cardiovascular events in RA patients without symptoms or prior diagnosis of cardiovascular disease.

Disclosure of Interests:

George Karpouzas Grant/research support from: Pfizer, Consultant of: Sanofi-Genzyme-Regeneron, Janssen, Speakers bureau: Sanofi-Genzyme-Regeneron, BMS, Sarah Ormseth: None declared, Elizabeth Hernandez: None declared, Matthew Budoff: None declared

THU0139 STATINS MODERATE THE EFFECT OF INFLAMMATION ON CORONARY PLAQUE PROGRESSION AND CARDIOVASCULAR DISEASE RISK IN RHEUMATOID ARTHRITIS

Background:

Cumulative inflammation correlates with coronary plaque increase and cardiovascular disease (CVD) events in rheumatoid arthritis (RA). Coronary plaque progression predicts CVD risk beyond baseline burden in general patients. Statins inhibit plaque progression and are effective for CVD prevention in general patients. Nevertheless, their impact on coronary plaque trajectory and CVD risk in RA are less clear.

Objectives:

To explore if statin treatment may reduce CVD event risk, inhibit new plaque formation or promote the regression or protective calcification of prevalent atherosclerotic lesions in RA. We also evaluated whether statins moderate the effects of inflammation (CRP) on CVD risk and on coronary plaque progression.

Methods:

One hundred-fifty patients underwent computed tomography angiography for coronary atherosclerosis evaluation (total, non-calcified, mixed/calcified plaque); 101 had repeat assessments within 6.9±0.3 years to evaluate plaque progression. CVD events were prospectively recorded, including cardiac death, myocardial infarction, unstable angina, revascularization, stroke, claudication, and heart failure hospitalization. Framingham-D’Agostino score assessed clinical risk. Plaque burden was measured as segment stenosis score (cumulative stenosis). Robust cox proportional hazards regression models evaluated the effects of time-varying statin use, log-transformed time-varying CRP (mg/dL) and their interaction on CVD risk controlling for Framingham-D’Agostino score, plaque burden and time-varying bDMARD use. Per-segment robust logistic regression assessed the effect of statin duration (years), log-transformed time-averaged CRP, and their interaction on likelihood of plaque formation in segments without plaque, and plaque regression or calcification in segments with non-calcified lesions. Models accounted for clustering of coronary segments within patients and controlled for Framingham-D’Agostino score, total prednisone dose, bDMARD duration, and time between scans.

Results:

Sixteen patients incurred 19 CVD events. There was no main effect of current statin use on CVD risk (adjusted HR 1.10, 95% CI 0.33-3.67). However, there was an interaction between current statin use and time-varying CRP (p-interaction=0.030); higher time-varying CRP predicted greater CVD risk in patients not receiving statins (adjusted HR 2.78, 95% CI 1.01-7.65), but not current statin users (Figure 1A). Likewise, current statin use associated with lower CVD risk when patients had higher time-varying CRP (>0.5 mg/dL) but not when CRP was lower (<0.5 mg/dL, Figure 1B). Statin duration had no main effect on new plaque formation in segments without plaque at baseline (adjusted OR 1.13, 95% CI 0.95-1.05); however, statin use moderated the effect of time-averaged CRP on new plaque formation (p-interaction=0.030, Figure 2A). Time-averaged CRP associated with a higher likelihood of new plaque in patients receiving statins less than one year (adjusted OR 1.75, 95% CI 1.38-2.20) but not those treated for longer (adjusted OR 1.26, 95% CI 0.78-2.02). In segments with non-calcified plaque, longer statin duration predicted protective calcification (adjusted OR 1.28, 95% CI 1.07-1.53, Figure 2B).

Conclusion:

In RA, statins moderated the effect of CRP on CVD event risk and new plaque formation in coronary segments without plaque. Longer statin duration was also associated with an increased likelihood of protective calcification of non-calcified plaque.

Disclosure of Interests:

George Karpouzas Grant/research support from: Pfizer, Consultant of: Sanofi-Genzyme-Regeneron, Janssen, Speakers bureau: Sanofi-Genzyme-Regeneron, BMS, Sarah Ormseth: None declared, Elizabeth Hernandez: None declared, Matthew Budoff: None declared

Dermoscopy comparative approach for early diagnosis in familial melanoma: influence of MC1R genotype

BACKGROUND

MC1R polymorphisms interact with CDKN2A mutations modulating melanoma risk and contribute to a less suspicious clinical and dermoscopic appearance of melanomas. Different strategies, including dermoscopic comparative approach and digital monitoring, are used for the melanoma diagnosis in this context.

OBJECTIVE

To analyse the diagnostic accuracy of the morphologic approach and comparative approach in dermoscopy, and to detect melanoma in familial melanoma (FamMM) patients according to different genetic backgrounds.

METHODS

Two independent readers evaluated 415 lesions belonging to 25 FamMM: 26 melanomas (62% in situ, 36% early invasive) and 389 naevi, blinded for dermoscopic and histopathologic diagnosis, following two different steps. First step-Randomized: all lesions were randomly located in one single folder. Second step-Comparative approach: the lesions were clustered by patient. Sensitivity, specificity and number needed to excise (NNE) for melanoma diagnosis were calculated for both diagnostic strategies. Sensitivity and specificity were also assessed regarding the genetic background.

RESULTS

The comparative approach showed lower sensitivity compared to the morphologic approach (69.2 and 73.1 vs. 76.9 both readers) but better specificity (95.9 and 95.1 vs. 84.3 and 90.2, respectively). NNE was better in the comparative approach. The readers had more difficulties diagnosing lesions from CDKN2A mutation carriers with red hair colour (RHC) MC1R variants.

CONCLUSION

The comparative approach can be useful in high-risk patients to decrease the NNE. Early melanomas in CDKN2A carriers with RHC polymorphisms are more difficult to diagnose even with the comparative approach and benefit from the detection of changes during digital dermoscopy monitoring for early diagnosis.

Abstract 1997: The Rac inhibitors HV-107 and HV-118 as potential therapeutics for metastatic breast cancer

Breast cancer is the first cause of death in women globally. Metastatic breast cancer is stimated to affect more than a quarter of million of women in the US. Due to the lack of effective treatment, metastasis remains the main cause of breast cancer mortality. Therefore, it is imperative to develop novel effective strategies against metastasis. A promising target for anti-metastatic therapy is the Rho GTPase Rac because it plays a key role in metastatic cancer progression by regulating cellular processes such as adhesion, migration, proliferation and survival. Our group developed Ehop-016, a small molecule that inhibits Rac in metastatic breast cancer cells with an IC50=1µM and significantly reduces tumor growth, angiogenesis, and metastasis in a mouse model of metastatic breast cancer. However, its relative bioavailability is moderate and should be improved. Therefore, to find a compound with increased potency and bioavailability, we tested several Ehop-016 derivatives. Using Rac pulldown assays we show that HV-107 and HV-118 inhibit Rac activation by 60% in MDA-MB-231 and MDA-MB-435 metastatic breast cancer cells at 100 and 250nM, respectively. MTT assays show HV-107 (at ≥500nM) and HV-118 (at ≥50nM) significantly inhibit metastatic breast cancer cell viability, while showing minimal toxicity towards non-cancerous cells. Cell cycle analysis by flow cytometry demonstrates a G2-M arrest and a prominent sub-G1 population, indicative of cell death, in metastatic breast cancer cells treated with HV-107 (1000 nM) and HV-118 (100 nM). To evaluate apoptosis as a potential cell death mechanism, we measured caspase 3 activity. Our results show HV-107 and HV-118 significantly induce caspase 3 activity by approximately 1.6-fold at 1000 and 100nM, respectively in metastatic breast cancer cells. Therefore, these Rac inhibitors affect cell viability by inhibiting cell cycle progression and inducing apoptosis. Finally, we tested HV-118 (at 1mg/kg BW) in a mouse model of metastatic breast cancer and found a 30% reduction in tumor growth and a 90% inhibition in metastasis. Taken together, our results indicate HV-107 and HV-118 have potential as anti-breast cancer metastasis therapeutics. This study was supported by awards from the Susan Komen for the Cure, NIH/NIMHHD U54MD008149, and the Puerto Rico Science and Technology Trust to SD; NIH/NCRR R25GM061838 to UPR MSC; NIH/NIMHHD RCMI 8G12MD007583RCMI, Title V PPOHA 031M10505 and Title V Cooperative P031S130068 from U.S. Department of Education to UCC; and and PRINBRE (NIH/NIGMS P20GM103475-13) Sub-Award to LCP.

Citation Format: Grace E. Velez, Cornelis Vlaar, Eliud Hernandez, Anibal Valentin, Linette Castillo-Pichardo, Suranganie Dharmawardhane. The Rac inhibitors HV-107 and HV-118 as potential therapeutics for metastatic breast cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 1997.

Massive recurrent post-tonsillectomy bleedings revealing a transient factor XIII deficiency in a 10-year-old boy. A case report

A previously healthy 10-year-old boy was hospitalized for a left cervical abscess associated with massive tonsillar hypertrophy. He underwent abscess drainage and bilateral tonsillectomy. At H36 post-surgery, he presented with tonsillar hemorrhage requiring surgical revision. Hemorrhage relapsed 2 days later, with a total of 7 episodes, 5 of which required surgical revisions. Laboratory investigations were normal except for a markedly low factor XIII (FXIII) activity at 7%. After administration of a single dose of 40 IU/kg plasma-derived FXIII (Fibrogammin^®) I.V., the bleeding stopped with no further recurrence. FXIII activity gradually normalized (75%) at 6 weeks, confirming the transient character of factor XIII deficiency. Severe congenital FXIII deficiency (FXIIID) (<1%) is very rare (1:2,000,000 births), whereas partial congenital deficiency and/or acquired deficiency may be more frequent but likely underreported. Acquired FXIIID may result from impaired synthesis (liver failure) or increased consumption (surgery, sepsis, leukemia, Henoch-Schönlein, inflammatory bowel disease, stroke, disseminated intravascular coagulation). FXIII replacement in form of fresh frozen plasma (FFP) or plasma-derived FXIII may be necessary for the presence of bleeding.

Abstract B094: The dual Rac/Cdc42 inhibitor MBQ-167 and derivatives as anticancer compounds

Metastatic disease lacks effective treatments, and remains the primary cause of mortality from epithelial cancers. The Rho family GTPases Rac and Cdc42 and their downstream effector p21-activated kinase (PAK) are pivotal regulators of metastatic cancer cell migration and invasion; thus, overexpression of Rac/Cdc42/PAK has been correlated with reduced patient survival in breast, gastric, and lung cancer. Our studies on the efficacy and pharmacokinetics of the Rac inhibitor EHop-016 (US patents # 8,884,006 B2; 9,278,956B1) validated the development of Rac and Cdc42 inhibitors as anti-metastatic cancer therapeutics. To improve the pharmacologic utility of EHop-016, structural derivatives were screened for enhanced efficacy and bioavailability. We recently identified a dual Rac and Cdc42 inhibitor, MetaBloq(MBQ)-167, which inhibits Rac and Cdc42 activation with IC50s of 103 nM for Rac inhibition and 78 nM for Cdc42 inhibition. Moreover, MBQ-167 is specific to cancer cells that have undergone epithelial-to-mesenchymal transition (EMT), but not epithelial cancer cells or noncancer cells. In metastatic cancer cells, MBQ-167 induces a unique phenotype of loss in cell polarity, cell surface actin extensions, and cell-substrate attachments to undergo anoikis (apoptosis due to inadequate cell-matrix interactions). In vivo, MBQ-167 inhibits HER2 type mammary tumor growth and metastasis in immunocompromised mice by ~90-100% (Humphries-Bickley et al., Mol Cancer Ther 2017; patent applications US 15/499532, PCT/US17/29921). In this study, we have further tested the pharmacokinetics and utility of MBQ-167 in additional models of cancer and screened MBQ-167 derivatives for their utility as Rac/Cdc42 inhibitors. Similar to the results with HER2 type breast cancer, in severe combined immunodeficiency (SCID) mice with mammary fat pad tumors from the triple-negative MDA-MB-231 human breast cancer cell line, the effect of MBQ-167 saturated at 1 mg/kg BW with a 80% reduction in tumor growth and a 100% reduction in metastasis. In gastric cancer, MBQ-167 reduced the viability of metastatic NCI-N87 gastric cancer cells, induced anoikis without affecting the AGS nonmetastatic gastric cancer cells, and inhibited tumor growth in SCID mice. We have screened a range of MBQ-167 derivatives for cell viability and the “anoikis” phenotype and isolated 4 compounds that reduced breast cancer cell viability with GI50s in the nM range. From this screen, MBQ-14 acts similar to MBQ-167, and thus is considered to be a viable inhibitor for further investigation. We have developed a quantitative method for identifying MBQ-167 and MBQ-14 from mouse plasma using ultra-performance convergence chromatography (UPC2)/MS/MS, and find that MBQ-167 is bioavailable in mouse plasma with a half-life of ~4h following oral or intraperitoneal administration. Overall our data demonstrate the utility of further developing MBQ-167 and derivatives as anti-metastatic cancer therapeutics.

Citation Format: Linette Castillo-PIchardo, Maria Del Mar Maldonado, Jean Ruiz-Calderon, Jose F. Rodriguez-Orengo, Eliud Hernandez, Cornelis Vlaar, Surangani F. Dharmawardhane Flanagan. The dual Rac/Cdc42 inhibitor MBQ-167 and derivatives as anticancer compounds [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2017 Oct 26-30; Philadelphia, PA. Philadelphia (PA): AACR; Mol Cancer Ther 2018;17(1 Suppl):Abstract nr B094.

Pelagic and benthic communities of the Antarctic ecosystem of Potter Cove: Genomics and ecological implications

Molecular technologies are more frequently applied in Antarctic ecosystem research and the growing amount of sequence-based information available in databases adds a new dimension to understanding the response of Antarctic organisms and communities to environmental change. We apply molecular techniques, including fingerprinting, and amplicon and metagenome sequencing, to understand biodiversity and phylogeography to resolve adaptive processes in an Antarctic coastal ecosystem from microbial to macrobenthic organisms and communities. Interpretation of the molecular data is not only achieved by their combination with classical methods (pigment analyses or microscopy), but furthermore by combining molecular with environmental data (e.g., sediment characteristics, biogeochemistry or oceanography) in space and over time. The studies form part of a long-term ecosystem investigation in Potter Cove on King-George Island, Antarctica, in which we follow the effects of rapid retreat of the local glacier on the cove ecosystem. We formulate and encourage new approaches to integrate molecular tools into Antarctic ecosystem research, environmental conservation actions, and polar ocean observatories.

Abstract 3076: Characterization of an improved derivative of the Rac/PAK inhibitor EHop-016 in breast cancer

The expression and activities of the Rho GTPases Rac and Cdc42, and their downstream effector P21-activated kinase (PAK), have been correlated with metastatic cancer. Our published studies with the Rac/PAK inhibitor EHop-016 demonstrate the validity of using Rac inhibitors as anti metastatic cancer therapeutics. However, the relatively high effective concentrations (Rac activity IC50 1μM, tumor inhibition at 25 mg/kg body weight (BW)), and the moderate bioavailability (∼30%, t1/2 4.5h) of EHop-016 need improvement. Therefore, we developed EHop-016 derivatives and identified EHop-167 as a Rac inhibitor at nM concentrations. Unlike EHop-016, which does not substantially change breast cancer cell shape, but only reduces cell surface actin based invadopodia, EHop-167 induced a marked decrease in breast cancer cell polarity, cell surface extensions, and cell-extracellular matrix (ECM) attachments (focal adhesions). This phenotype of cell rounding and detachment in response to EHop-167 was demonstrated only by breast cancer cell lines that have undergone epithelial to mesenchymal transition, but not by epithelial breast cancer cells, or MCF-10A mammary epithelial cells. As assessed by pulldown assays and western blotting, Rac and PAK activities were reduced by 80-90% in response to 250 nM EHop-167, in the detached cells. As demonstrated by caspase assays, the cell rounding and detachment from the ECM ultimately resulted in anoikis (cell death due to loss of focal adhesions). Accordingly, Transwell assays of mesenchymal breast cancer cells following 250 nM Ehop-167 showed a ∼90% reduction in cell migration in the detached breast cancer cells, and a ∼60% inhibition in the attached cells. EHop-167 also reduced the mammosphere formation efficiency of metastatic cancer cells by 50%, indicating an inhibitory effect on cancer stem cells. To determine the in vivo efficacy of EHop-167, athymic nude mice, bearing mammary fatpad tumors of MDA-MB-435 metastatic cancer cells, were treated 3X a week with 0, 1, or 10 mg/kg BW EHop-167 for 50 days. Treatment with 1.0 mg/kg BW EHop-167 resulted in a 50% reduction in tumor growth, while 10.0 mg/kg BW EHop-167 induced an ∼95% reduction in tumor growth, compared to controls. Additionally, these mice did not show gross signs of toxicity or significant weight loss. Since the parental compound EHop-016 has no anticancer effects at similar concentrations, we conclude that EHop-167 is an improved Rac/PAK inhibitor that holds promise as an anti metastatic breast cancer therapeutic.

Citation Format: Linette Castillo-Pichardo, Tessa Humphries-Bickley, Ingrid Forrestier-Roman, Luis Borrero-Garcia, Fabiola Pagan Melendez, Eliud Hernandez, Cornelis Vlaar, Luis A. Cubano, Surangani Dharmawardhane. Characterization of an improved derivative of the Rac/PAK inhibitor EHop-016 in breast cancer. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 3076.

Site selective activation of lateral hypothalamic mGluR1 and R5 receptors elicits feeding in rats

Recent findings from our lab indicate that metabotropic glutamate receptor (mGluR) activation elicits eating, and the goal of the current study was to specify whether the lateral hypothalamus (LH) is the actual brain site mediating this effect. To examine this issue we injected the selective mGluR group I agonist (S)-3,5-dihydroxyphenylglycine (DHPG) unilaterally into the LH and surrounding regions (n=5-8 subjects/brain site) of satiated adult male Sprague-Dawley rats and measured elicited feeding. We determined that 1.0 nmol elicited food intake only within the LH. Increasing the dose to 10 or 25 nmol produced a more sustained effect in the LH, and also elicited eating in several other brain sites. These results, demonstrating that the LH mediates the eating elicited by low doses of DHPG, suggest that the LH may contain mGluR whose activation can produce eating behavior.

The Rac Inhibitor EHop-016 Inhibits Mammary Tumor Growth and Metastasis in a Nude Mouse Model

Metastatic disease still lacks effective treatments, and remains the primary cause of cancer mortality. Therefore, there is a critical need to develop better strategies to inhibit metastatic cancer. The Rho family GTPase Rac is an ideal target for anti-metastatic cancer therapy, because Rac is a key molecular switch that is activated by a myriad of cell surface receptors to promote cancer cell migration/invasion and survival. Previously, we reported the design and development of EHop-016, a small molecule compound, which inhibits Rac activity of metastatic cancer cells with an IC₅₀ of 1 μM. EHop-016 also inhibits the activity of the Rac downstream effector p21-activated kinase (PAK), lamellipodia extension, and cell migration in metastatic cancer cells. Herein, we tested the efficacy of EHop-016 in a nude mouse model of experimental metastasis, where EHop-016 administration at 25 mg/kg body weight (BW) significantly reduced mammary fat pad tumor growth, metastasis, and angiogenesis. As quantified by UPLC MS/MS, EHop-016 was detectable in the plasma of nude mice at 17 to 23 ng/ml levels at 12 h following intraperitoneal (i.p.) administration of 10 to 25 mg/kg BW EHop-016. The EHop-016 mediated inhibition of angiogenesis In Vivo was confirmed by immunohistochemistry of excised tumors and by In Vitro tube formation assays of endothelial cells. Moreover, EHop-016 affected cell viability by down-regulating Akt and Jun kinase activities and c-Myc and Cyclin D expression, as well as increasing caspase 3/7 activities in metastatic cancer cells. In conclusion, EHop-016 has potential as an anticancer compound to block cancer progression via multiple Rac-directed mechanisms.

Abstract A155: The Rac and PAK inhibitor EHop-016 inhibits mammary tumor growth and metastasis in a nude mouse model

The Rho GTPase Rac is a central regulator of cancer cell migration/invasion that has been implicated with cancer metastasis. Therefore, we designed and developed small molecule compounds that specifically target Rac in metastatic cancer cells. We recently reported the characterization of EHop-016 as a Rac inhibitor in metastatic cancer cells, where EHop-016 was shown to inhibit Rac activity with an IC50 of 1 μM. At higher concentrations (&gt;10 μM) EHop-016 reduced cell viability and inhibited the related Rho GTPase Cdc42, but not Rho. EHop-016 decreased the activation of Rac by the oncogenic guanine nucleotide exchange factor Vav, the activity of the Rac effector p21-activated kinase (PAK), and the extension of actin cytoskeletal structures and migration of metastatic cancer cells. Next, we determined the efficacy of EHop-016 in vivo, using a mouse model of experimental metastasis. Green fluorescent protein (GFP) tagged MDA-MB-435 human metastatic cancer cells were inoculated at the mammary fat pad of nude mice and treated with 0, 5, 10, 25, or 40 mg/kg body weight (BW) EHop-016 3X a week for ∼8 weeks. Mammary tumor growth and metastases in lungs, spleens, kidneys, livers, hearts, and femurs were quantified by fluorescence image analysis. At concentrations &gt;10 mg/kg BW, EHop-016 significantly inhibited mammary tumor growth and metastasis to distant organs. EHop-016 had no effect on mouse weight or their gross phenotype, indicating that EHop-016 did not exert toxic effects in athymic nude mice. This data demonstrate that EHop-016 and derivatives hold promise for further development as targeted anti-cancer therapeutics.

Citation Information: Mol Cancer Ther 2013;12(11 Suppl):A155.

Citation Format: Linette Castillo-Pichardo, Tessa Humphries-Bickley, Eliud Hernandez, Columba de la Parra, Luis Cubano, Cornelis Vlaar, Surangani F. Dharmawardhane Flanagan. The Rac and PAK inhibitor EHop-016 inhibits mammary tumor growth and metastasis in a nude mouse model. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2013 Oct 19-23; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2013;12(11 Suppl):Abstract nr A155.

Development of EHop-016: a small molecule inhibitor of Rac

The Rac inhibitor EHop-016 was developed as a compound with the potential to inhibit cancer metastasis. Inhibition of the first step of metastasis, migration, is an important strategy for metastasis prevention. The small GTPase Rac acts as a pivotal binary switch that is turned "on" by guanine nucleotide exchange factors (GEFs) via a myriad of cell surface receptors, to regulate cancer cell migration, survival, and proliferation. Unlike the related GTPase Ras, Racs are not usually mutated, but overexpressed or overactivated in cancer. Therefore, a rational Rac inhibitor should block the activation of Rac by its upstream effectors, GEFs, and the Rac inhibitor NSC23766 was developed using this rationale. However, this compound is ineffective at inhibiting the elevated Rac activity of metastatic breast cancer cells. Therefore, a panel of small molecule compounds were derived from NSC23766 and screened for Rac activity inhibition in metastatic cancer cells. EHop-016 was identified as a compound that blocks the interaction of Rac with the GEF Vav in metastatic human breast cancer cells with an IC50 of ~1μM. At higher concentrations (10μM), EHop-016 inhibits the related Rho GTPase Cdc42, but not Rho, and also reduces cell viability. Moreover, EHop-016 inhibits the activation of the Rac downstream effector p21-activated kinase, extension of motile actin-based structures, and cell migration. Future goals are to develop EHop-016 as a therapeutic to inhibit cancer metastasis, either individually or in combination with current anticancer compounds. The next generation of EHop-016-based Rac inhibitors is also being developed.

Concurrent chemoradiation (CChRT) with bi-weekly docetaxel and cisplatin and thoracic radiotherapy for stage III non-small cell lung cancer (NSCLC): A phase II study from the Galician Lung Cancer Group

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Background: CChRT is recommended as the evidence-based approach for the management of patients (p) with locally advanced stage III NSCLC and a good performance status, although a clearly superior regimen has not been identified. The aim of our study was to evaluate the effectiveness and toxicities of CChRT with bi-weekly docetaxel (D) and cisplatin (C) and thoracic radiotherapy. Methods: 50 p with histologically confirmed inoperable locally advanced NSCLC, stage IIIAN2/IIIB (no pleural T4), PS 0-1 and adequate lung function (FEV1 > 1.1, V20 < 25%) were included: one cycle of D 75 mg/m2 on day 1 and C 40 mg/m2 days 1-2 followed at 21 days by CChRT with bi-weekly D 40 mg/m2 and C 40 mg/m2 for four courses, during conformal thoracic radiotherapy (66 Gys, 180 cGy/day). The primary objective was overall survival (OS); secondary objectives were progression free survival (PFS), response rate (RR) and toxicity. Median follow-up: 14,5 months. Results: The p characteristics were: mean age 59,1 years (34-75); male/female 44/6; squamous/adeno/large cell carcinoma: 52%/34%/14%; stage IIIAN2 14 p (28%) and stage IIIB 36 p (72%). All p were evaluable for response and toxicity. RR: 4 CR, 36 PR (RR 80%; 95% CI:69-91), 4 SD (8%) and 6 PD (12%). The median PFS was 13 months (95% CI:8-18) and median OS was 19 months (95% CI:14-24). The PFS and OS at 1/2 years were 52%/30% and 79%/40% respectively. A total of 50 cycles of D-C induction chemotherapy were given; main toxicities (NCI-CTC 3.0) per p Grade (g) 1-2/3-4 (%) were as follows: neutropenia 2/16; anemia 12/0; nausea/vomiting 28/2; diarrhea 22/4; there were two episodes of febrile neutropenia. Main toxicities per p in CChRT (D-C doses: 192, 3.8 per p; mean doses RT: 64,6 Gys) were g1-2/3 (%): neutropenia 28/6; anemia 60/0; esophagitis 52/4 and pneumonitis 34/0; there were four episodes of hospitalization: febrile neutropenia, 2 p and g3 esophagitis, 2 p. Conclusions: CChRT with bi-weekly docetaxel and cisplatin and thoracic radiotherapy is a feasible treatment option for inoperable locally advanced stage III NSCLC, showing good clinical efficacy and tolerability with acceptable long-term survival.