Journal of Molecular Medicine / The FAK inhibitor BI 853520 inhibits spheroid formation and orthotopic tumor growth in malignant pleural mesothelioma

No tyrosine kinase inhibitors are approved for malignant pleural mesothelioma (MPM). Preclinical studies identified focal adhesion kinase (FAK) as a target in MPM. Accordingly, we assessed the novel, highly selective FAK inhibitor (BI 853520) in 2D and 3D cultures and in vivo. IC50 values were measured by adherent cell viability assay. Cell migration and 3D growth were quantified by video microscopy and spheroid formation, respectively. Phosphorylation of FAK, Akt, S6, and Erk was measured by immunoblot. The mRNA expression of the putative tumor stem cell markers SOX2, Nanog, CD44, ALDH1, c-myc, and Oct4 was analyzed by qPCR. Cell proliferation, apoptosis, and tumor tissue microvessel density (MVD) were investigated in orthotopic MPM xenografts. In all 12 MPM cell lines, IC50 exceeded 5 M and loss of NF2 did not correlate with sensitivity. No synergism was found with cisplatin in adherent cells. BI 853520 decreased migration in 3 out of 4 cell lines. FAK phosphorylation was reduced upon treatment but activation of Erk, Akt, or S6 remained unaffected. Nevertheless, BI 853520 inhibited spheroid growth and significantly reduced tumor weight, cell proliferation, and MVD in vivo. BI 853520 has limited effect in adherent cultures but demonstrates potent activity in spheroids and in orthotopic tumors in vivo. Based on our findings, further studies are warranted to explore the clinical utility of BI 853520 in human MPM.(VLID)365713

Circulating activin A is a novel prognostic biomarker in malignant pleural mesothelioma - A multi-institutional study

INTRODUCTION: The deregulation of activin expression is often observed in various malignancies. Previous studies indicate that activin A plays a protumourigenic role in malignant pleural mesothelioma (MPM). The aim of the study was to evaluate circulating activin A level as a biomarker in MPM. METHODS: Plasma samples were collected from 129 MPM patients in four institutions at the time of diagnosis or before surgical resection. Samples from 45 healthy individuals and from 16 patients with non-malignant pleural diseases served as controls. Circulating activin A was measured by enzyme-linked immunosorbent assay and correlated to clinicopathological variables. RESULTS: Plasma activin A level was significantly elevated in MPM patients (862 +/- 83 pg/ml) when compared to healthy controls (391 +/- 21 pg/ml; P < 0.0001). Patients with pleuritis or fibrosis only showed a modest increase (versus controls; 625 +/- 95 pg/ml; P = 0.0067). Sarcomatoid (n = 10, 1629 +/- 202 pg/ml, P = 0.0019) and biphasic (n = 23, 1164 +/- 233 pg/ml, P = 0.0188) morphology were associated with high activin A levels when compared to epithelioid histology (n = 94, 712 +/- 75 pg/ml). The tumour volume showed a positive correlation with increased circulating activin A levels. MPM patients with below median activin A levels had a significantly longer overall survival when compared to those with high activin A levels (median survival 735 versus 365 d, P < 0.0001). Importantly, circulating activin A levels were exclusively prognostic in epithelioid MPM. CONCLUSIONS: Our findings suggest that the measurement of circulating activin A may support the histological classification of MPM and at the same time help to identify epithelioid MPM patients with poor prognosis

Impact of safety-related dose reductions or discontinuations on sustained virologic response in HCV-infected patients: Results from the GUARD-C Cohort

Background: Despite the introduction of direct-acting antiviral agents for chronic hepatitis C virus (HCV) infection, peginterferon alfa/ribavirin remains relevant in many resource-constrained settings. The non-randomized GUARD-C cohort investigated baseline predictors of safety-related dose reductions or discontinuations (sr-RD) and their impact on sustained virologic response (SVR) in patients receiving peginterferon alfa/ribavirin in routine practice. Methods: A total of 3181 HCV-mono-infected treatment-naive patients were assigned to 24 or 48 weeks of peginterferon alfa/ribavirin by their physician. Patients were categorized by time-to-first sr-RD (Week 4/12). Detailed analyses of the impact of sr-RD on SVR24 (HCV RNA <50 IU/mL) were conducted in 951 Caucasian, noncirrhotic genotype (G)1 patients assigned to peginterferon alfa-2a/ribavirin for 48 weeks. The probability of SVR24 was identified by a baseline scoring system (range: 0-9 points) on which scores of 5 to 9 and <5 represent high and low probability of SVR24, respectively. Results: SVR24 rates were 46.1 % (754/1634), 77.1% (279/362), 68.0% (514/756), and 51.3% (203/396), respectively, in G1,2, 3, and 4 patients. Overall, 16.9% and 21.8% patients experienced ≥1 sr-RD for peginterferon alfa and ribavirin, respectively. Among Caucasian noncirrhotic G1 patients: female sex, lower body mass index, pre-existing cardiovascular/pulmonary disease, and low hematological indices were prognostic factors of sr-RD; SVR24 was lower in patients with ≥1 vs. no sr-RD by Week 4 (37.9% vs. 54.4%; P = 0.0046) and Week 12 (41.7% vs. 55.3%; P = 0.0016); sr-RD by Week 4/12 significantly reduced SVR24 in patients with scores <5 but not ≥5. Conclusions: In conclusion, sr-RD to peginterferon alfa-2a/ribavirin significantly impacts on SVR24 rates in treatment-naive G1 noncirrhotic Caucasian patients. Baseline characteristics can help select patients with a high probability of SVR24 and a low probability of sr-RD with peginter-feron alfa-2a/ribavirin