👤 André E S Simões

Chronic exposure to second-hand smoke (SHS) contributes to the development of health issues, including cancer and cardiovascular diseases. Molecular mechanisms underlying SHS-related diseases remain poorly understood, highlighting the need for reliable risk assessment biomarkers. Herein, we demonstrate that the plasma proteome of individuals exposed to SHS undergoes significant modulation. Butyrylcholinesterase (BChE) and Vitamin D-binding protein (GC) that are involved in the physiological response to circulating toxic substances, as well as key mediators of systemic inflammation, including Complement C1r subcomponent (C1R), Complement C1q subcomponent subunit C (C1QC), Histidine-rich glycoprotein (HRG), and Vitamin K-dependent protein S (PROS1), were found to be significantly modulated in SHS-exposed individuals. Moreover, strong indicators of a pro-atherothrombotic response such Apolipoprotein A-IV (APOA4) and Alpha-2-antiplasmin (SERPINF2), were also differentially expressed. These findings provide novel insights into the biological pathways linking SHS-exposure to cardiovascular risks, and suggest a panel of candidate proteins with potential utility as SHS-risk assessment biomarkers. Show less

Conventional mitogen-activated protein kinase (MAPK) family members are among the most sought-after oncogenic effectors for the development of novel human cancer treatment strategies. MEK5/ERK5 has been the less-studied MAPK subfamily, despite its increasingly demonstrated relevance in the growth, survival, and differentiation of normal cells. MEK5/ERK5 signalling has already been proposed to have pivotal roles in several cancer hallmarks, and to mediate the effects of a range of oncogenes. Accumulating evidence indicates the contribution of MEK5/ERK5 signalling to therapy resistance and the benefits of using MEK5/ERK5 inhibitory strategies in the treatment of human cancer. Here, we explore the major known contributions of MEK5/ERK5 signalling to the onset and progression of several types of cancer, and highlight the potential clinical relevance of targeting MEK5/ERK5 pathways. Show less

The MEK5/ERK5 signaling pathway is emerging as an important contributor to colon cancer onset, progression and metastasis; however, its relevance to chemotherapy resistance remains unknown. Here, we evaluated the impact of the MEK5/ERK5 cascade in colon cancer cell sensitivity to 5-fluorouracil (5-FU). Increased ERK5 expression was correlated with poor overall survival in colon cancer patients. In colon cancer cells, 5-FU exposure impaired endogenous KRAS/MEK5/ERK5 expression and/or activation. In turn, MEK5 constitutive activation reduced 5-FU-induced cytotoxicity. Using genetic and pharmacological approaches, we showed that ERK5 inhibition increased caspase-3/7 activity and apoptosis following 5-FU exposure. Mechanistically, this was further associated with increased p53 transcriptional activation of p21 and PUMA. In addition, ERK5 inhibition increased the response of HCT116 p53+/+ cells to 5-FU, but failed to sensitize HCT116 p53-/- cells to the cytotoxic effects of this chemotherapeutic agent, suggesting a p53-dependent axis mediating 5-FU sensitization. Finally, ERK5 inhibition using XMD8-92 was shown to increase the antitumor effects of 5-FU in a murine subcutaneous xenograft model, enhancing apoptosis while markedly reducing tumor growth. Collectively, our results suggest that ERK5-targeted inhibition provides a promising therapeutic approach to overcome resistance to 5-FU-based chemotherapy and improve colon cancer treatment. Show less