EPAC1 inhibition protects the heart from doxorubicin-induced toxicity

Anthracyclines, such as doxorubicin (Dox), are widely used chemotherapeutic agents for the treatment of solid tumors and hematologic malignancies. However, they frequently induce cardiotoxicity leading to dilated cardiomyopathy and heart failure. This study sought to investigate the role of the exchange protein directly activated by cAMP (EPAC) in Dox-induced cardiotoxicity and the potential cardioprotective effects of EPAC inhibition. We show that Dox induces DNA damage and cardiomyocyte cell death with apoptotic features. Dox also led to an increase in both cAMP concentration and EPAC1 activity. The pharmacological inhibition of EPAC1 (with CE3F4) but not EPAC2 alleviated the whole Dox-induced pattern of alterations. When administered in vivo, Dox-treated WT mice developed a dilated cardiomyopathy which was totally prevented in EPAC1 knock-out (KO) mice. Moreover, EPAC1 inhibition potentiated Dox-induced cell death in several human cancer cell lines. Thus, EPAC1 inhibition appears as a potential therapeutic strategy to limit Dox-induced cardiomyopathy without interfering with its antitumoral activity.

Prevalence of Hereditary Thrombophilia in Patients Older Than 75 Years With Venous Thromboembolism Referred for Thrombophilia Screening

BACKGROUND

Few studies focused on genetic risk factors for venous thromboembolism (VTE) in the very elderly people. In patients aged 75 years and older with VTE referred for laboratory screening tests for thrombophilia, we aimed: (i) to estimate the F5G1691A and F2G20210A mutation prevalence; (ii) to compare prevalence rates with those of a control group; and (iii) to compare the prevalence rates between patient subgroups, defined as with one or multiple VTE episodes and with provoked/unprovoked VTE.

METHODS

Data were extracted from two prospective thrombophilia registries according to the following inclusion criteria: Caucasian patients aged 75 years and older presenting with at least one confirmed VTE episode. Associated VTE risk factors had been recorded using a standardized questionnaire. Laboratory tests included plasma antithrombin, protein C, and protein S activity measurements and F5G1691A and F2G20210A genotyping.

RESULTS

Of the 312 patients (mean age: 84 ± 6 years; 245 women and 67 men), 47.1% had two or more VTE episodes and 63.5% patients had unprovoked VTE. None had deficiencies in antithrombin, protein C, or protein S. The F5G1691A and F2G20210A mutations were found in 29 (9.3%, 95% confidence interval [CI]: 6.3-13.1) and 18 (5.8%, 95% CI: 3.5-9.0) patients, respectively, versus 3.4% (95% CI: 1.9-4.9) and 3.1% (95% CI: 2.6-3.5) in control subjects (p = .0002 and p = .0082, respectively). Overall, 45 (14.4%) patients carried at least one mutated allele. No associations were found between F5G1691A/F2G20210A, unprovoked VTE or recurrence (p > .05).

CONCLUSIONS

Our study provides new data on genetic risk factors for VTE in the very elderly people. Whether identification of hereditary thrombophilia in elderly patients may influence patient's management in this age group remains unanswered.