1.
Active notch protects MAPK activated melanoma cell lines from MEK inhibitor cobimetinib.
Porcelli, L, Mazzotta, A, Garofoli, M, Di Fonte, R, Guida, G, Guida, M, Tommasi, S, Azzariti, A
Biomedicine & pharmacotherapy = Biomedecine & pharmacotherapie. 2021;:111006
Abstract
The crosstalk between Notch and MAPK pathway plays a role in MEK inhibitor resistance in BRAFV600E metastatic melanoma (MM) and promotes migration in GNAQQ209L uveal melanoma (UM) cells. We determined the cytotoxicity of combinatorial inhibition of MEK and Notch by cobimetinib and γ-secretase inhibitor (GSI) nirogacestat, in BRAFV600E and BRAF wt MM and GNAQQ209L UM cells displaying different Erk1/2 and Notch activation status, with the aim to elucidate the impact of Notch signaling in the response to MEK inhibitor. Overall the combination was synergic in BRAFV600E MM and GNAQQ209L UM cells and antagonistic in BRAF wt one. Focusing on UM cells, we found that cobimetinib resulted in G0/G1 phase arrest and apoptosis induction, whereas the combination with GSI increased treatment efficacy by inducing a senescent-like state of cells and by blocking migration towards liver cancer cells. Mechanistically, this was reflected in a strong reduction of cyclin D1, in the inactivation of retinoblastoma protein and in the increase of p27KIP1 expression levels. Of note, each drug alone prevented Notch signaling activation resulting in inhibition of c-jun(Ser63) and Hes-1 expression. The combination achieved the strongest inhibition on Notch signaling and on both c-jun(Ser63) and Erk1/2 activation level. In conclusion we unveiled a coordinate action of MAPK and Notch signaling in promoting proliferation of BRAFV600E MM and GNAQQ209L UM cells. Remarkably, the simultaneous inhibition of MEK and Notch signaling highlighted a role for the second pathway in protecting cells against senescence in GNAQQ209L UM cells treated with the MEK inhibitor.
2.
Siponimod (BAF312) Activates Nrf2 While Hampering NFκB in Human Astrocytes, and Protects From Astrocyte-Induced Neurodegeneration.
Colombo, E, Bassani, C, De Angelis, A, Ruffini, F, Ottoboni, L, Comi, G, Martino, G, Farina, C
Frontiers in immunology. 2020;:635
Abstract
Multiple sclerosis (MS) is an inflammatory neurodegenerative disease of the central nervous system (CNS) with heterogeneous pathophysiology. In its progressive course oligodendrocyte and neuroaxonal damage is sustained by compartmentalized inflammation due to glial dysregulation. Siponimod (BAF312), a modulator of two sphingosine-1-phosphate (S1P) receptors (S1P1 and S1P5) is the first oral treatment specifically approved for active secondary progressive MS. To address potential direct effects of BAF312 on glial function and glia-neuron interaction, we set up a series of in vitro functional assays with astrocytes generated from human fibroblasts. These cells displayed the typical morphology and markers of astroglia, and were susceptible to the action of inflammatory mediators and BAF312, because expressing receptors for IL1, IL17, and S1P (namely S1P1 and S1P3). Targeting of S1P signaling by BAF312 inhibited NFκB translocation evoked by inflammatory cytokines, indicating a direct anti-inflammatory activity of the drug on the human astrocyte. Further, while glia cells exposed to IL1 or IL17 downregulated protein expression of glutamate transporters, BAF312-treated astrocytes maintained high levels of GLAST and GLT1 regardless of the presence of inflammatory mediators. Interestingly, despite potential glial susceptibility to S1P signaling via S1P3, which is not targeted by BAF312, NFκB translocation and downregulation of glutamate transporters in response to S1P were inhibited at similar levels by BAF312 and FTY720, another S1P signaling modulator targeting also S1P3. Accordingly, specific inhibition of S1P1 via NIBR-0213 blocked S1P-evoked NFκB translocation, demonstrating that modulation of S1P1 is sufficient to dampen signaling via other S1P receptors. Considering that NFκB-dependent responses are regulated by Nrf2, we measured activation of this critical transcription factor for anti-oxidant reactions, and observed that BAF312 rapidly induced nuclear translocation of Nrf2, but this effect was attenuated in the presence of an inflammatory milieu. Finally, in vitro experiments with spinal neurons exposed to astrocyte-conditioned media showed that modulation of S1P or cytokine signaling in astrocytes via BAF312 prevented neurons from astrocyte-induced degeneration. Overall, these experiments on human astrocytes suggest that during neuroinflammation targeting of S1P1 via BAF312 may modulate key astrocyte functions and thereby attain neuroprotection indirectly.
3.
Comparative efficacy and safety of tofacitinib, baricitinib, upadacitinib, filgotinib and peficitinib as monotherapy for active rheumatoid arthritis.
Ho Lee, Y, Gyu Song, G
Journal of clinical pharmacy and therapeutics. 2020;(4):674-681
Abstract
WHAT IS KNOWN AND OBJECTIVE Several clinical trials have attempted to evaluate the efficacy and safety of tofacitinib, baricitinib, upadacitinib, filgotinib and peficitinib as monotherapy in patients with active rheumatoid arthritis (RA), but their relative efficacy and safety as monotherapy remain unclear due to the lack of data from head-to-head comparison trials. The relative efficacy and safety of tofacitinib, baricitinib, upadacitinib, filgotinib and peficitinib as monotherapy for rheumatoid arthritis (RA) were assessed. METHODS We performed a Bayesian network meta-analysis to combine direct and indirect evidence from randomized controlled trials (RCTs) and examine the efficacy and safety of tofacitinib, baricitinib, upadacitinib, filgotinib and peficitinib as monotherapy relative to placebo in patients with RA. RESULTS AND DISCUSSION Five RCTs comprising 1547 patients met the inclusion criteria. Compared with placebo, tofacitinib, baricitinib, upadacitinib, filgotinib and peficitinib as monotherapy showed a significantly higher American College of Rheumatology 20% (ACR20) response rate. Peficitinib 150 mg monotherapy showed the highest ACR20 response rate (odds ratio, 17.24.39; 95% credible interval, 6.57-51.80). The ranking probability based on the surface under the cumulative ranking curve indicated that peficitinib 150 mg had the highest probability of being the best treatment for achieving the ACR20 response rate, followed by peficitinib 100 mg, filgotinib 200 mg, filgotinib 100 mg, tofacitinib 5 mg, upadacitinib 15 mg, baricitinib 4 mg and placebo. However, the number of patients who experienced serious adverse events did not differ significantly between the JAK inhibitors, except for tofacitinib 5 mg, and placebo. WHAT IS NEW AND CONCLUSION All five JAK inhibitors-tofacitinib, baricitinib, upadacitinib, filgotinib and peficitinib-were efficacious monotherapy interventions for active RA, and differences were noted in their efficacy and safety in monotherapy.