Cigarette smoke (CS) is a risk factor for inflammatory diseases, such as atherosclerosis. CS condensate (CSC) contains lipophilic components that may represent a systemic cardiac risk factor. To better understand CSC effects, we incubated mouse and human aortic smooth muscle cells (SMCs) with CSC. We evaluated specific markers for contractile [i.e., actin, aortic smooth muscle (ACTA2), calponin-1 (CNN1), the Kruppel-like factor 4 (KLF4), and myocardin (MYOCD) genes] and inflammatory [i.e., IL-1β, and IL-6, IL-8, and galectin-3 (LGALS-3) genes] phenotypes. CSC increased the expression of inflammatory markers and reduced the contractile ones in both cell types, with KLF4 modulating the SMC phenotypic switch. Next, we performed a mass spectrometry-based differential proteomic approach on human SMCs and could show 11 proteins were significantly affected by exposition to CSC (FC ≥ 2.7, p ≤ 0.05). These proteins are active in signaling pathways related to expression of pro-inflammatory cytokines and IFN, inflammasome assembly and activation, cytoskeleton regulation and SMC contraction, mitochondrial integrity and cellular response to oxidative stress, proteostasis control via ubiquitination, and cell proliferation and epithelial-to-mesenchymal transition. Through specific bioinformatics resources, we showed their tight functional correlation in a close interaction niche mainly orchestrated by the interferon-induced double-stranded RNA-activated protein kinase (alternative name: protein kinase RNA-activated; PKR) (EIF2AK2/PKR). Finally, by combining gene expression and protein abundance data we obtained a hybrid network showing reciprocal integration of the CSC-deregulated factors and indicating KLF4 and PKR as the most relevant factors.

A promising approach for the development of high-affinity tumor targeting ADCs is the use of engineered protein drugs, such as affibody molecules, which represent a valuable alternative to monoclonal antibodies (mAbs) in cancer-targeted therapy. We developed a method for a more efficient purification of the Z_HER2:2891DCS affibody conjugated with the cytotoxic antimitotic agent auristatin E (MMAE), and its efficacy was tested in vitro on cell viability, proliferation, migration, and apoptosis. The effects of Z_HER2:2891DCS-MMAE were compared with the clinically approved monoclonal antibody trastuzumab (Herceptin^®). To demonstrate that Z_HER2:2891DCS-MMAE can selectively target HER2 overexpressing tumor cells, we used three different cell lines: the human adenocarcinoma cell lines SK-BR-3 and ZR-75-1, both overexpressing HER2, and the triple-negative breast cancer cell line MDA-MB-231. MTT assay showed that Z_HER2:2891DCS-MMAE induces a significant time-dependent toxic effect in SK-BR-3 cells. A 30% reduction of cell viability was already found after 10 min exposure at a concentration of 7 nM (IC₅₀ of 80.2 nM). On the contrary, MDA-MB-231 cells, which express basal levels of HER2, were not affected by the conjugate. The cytotoxic effect of the Z_HER2:2891DCS-MMAE was confirmed by measuring apoptosis by flow cytometry. In SK-BR-3 cells, increasing concentrations of conjugated affibody induced cell death starting from 10 min of treatment, with the strongest effect observed after 48 h. Overall, these results demonstrate that the ADC, formed by the anti-HER2 affibody conjugated to monomethyl auristatin E, efficiently interacts with high affinity with HER2 positive cancer cells in vitro, allowing the selective and specific delivery of the cytotoxic payload.

Vascular smooth muscle cell (SMC) phenotypic switching, from a contractile to a synthetic state, impacts on atherosclerotic plaque development. While traditional cigarette (TC) smoke is a known driver of cardiovascular disease, the effects of alternative nicotine delivery systems, i.e. electronic cigarettes (E-cigs) and tobacco heating products (THPs), on SMC behavior remains poorly understood. We evaluated the effects of water-soluble components collected in aqueous extracts (AEs) from TC, E-cig, and THP smoke, on human aortic SMC (HASMC) phenotypic switch. HASMCs were treated for 48 h with the three AEs. Gene expression and protein abundance profiles were assessed to evaluate cell phenotypic modulation, proliferation, migration, extracellular matrix remodeling, and inflammatory responses. Label-free MS/MS proteomic analysis and wound healing assays were also used to further characterize cellular responses. Different AEs induced distinct gene expression and protein patterns, but all seemed to induce a hybrid contractile-synthetic phenotype. TC and THP extracts increased MMP3 expression, whereas E-cig AE downregulated MMPs. E-cig extracts, although reducing inflammatory cytokines, enhanced HASMC proliferation and migration, bona fide by upregulating PCNA, RAC1, and ROCK2, thus suggesting an increased vascular remodeling. Proteomic analysis indicated mitochondrial dysfunction and redox imbalances further advising about distinct, harmful effects of AEs on vascular health and atherosclerotic lesion progression. Our findings revealed complex differential molecular effects of TC, E-cig, and THP AEs on HASMC biology, emphasizing the necessity for further research to assess their actual long-term cardiovascular implications.

Antibody-drug conjugates (ADCs) are used in anticancer therapy with some limitations due to their molecular properties. An alternative to monoclonal antibodies is the affibody, composed of 58 amino acids, with lower binding affinities, small size, and rapid blood clearance and tissue distribution. We investigate the in vitro efficacy of a novel anti-HER2 ZHER2:2891 affibody conjugated to a cytotoxic drug auristatin E (MMAE) in HER2-positive human cancer cells. An adenocarcinoma cell line SK-BR-3, expressing high levels of HER2, and mammary gland adenocarcinoma MDA-MB-231, expressing basal levels of HER2, were treated with ZHER2:2891DCS-MMAE and trastuzumab (as a reference compound). ZHER2:2891DCS-MMAE induced a significant time-dependent toxic effect in SK-BR-3 cells. A 30% reduction in cell viability was found after 10 min exposure at 7 nM with an IC50 of 80.2 nM. On the contrary, MDA-MB-231 cells were not affected by the affibody complex. The HER2-specific cytotoxic effect of the ZHER2:2891DCS-MMAE has also been confirmed by measuring apoptosis by flow cytometry. In SK-BR-3 cells, the increasing concentrations of the conjugated affibody induced cell death after 10 min of treatment with the strongest effect observed after 48 h. Moreover, treatment with ZHER2:2891DCS-MMAE reduced (up to 50%) HER2 expression at both mRNA and protein levels in SK-BR-3 cells after 24 h of treatment. In conclusion, the cytotoxic conjugate based on the anti-HER2 affibody and MMAE efficiently interacts with HER2 over-expressing cancer cells, allowing the selective and specific delivery of the cytotoxic payload. The basal HER2 expressing cells are not the most affected probably due to a lower uptake of the drug conjugate. This confirms that affibodies may be used to target HER2 overexpressing cells while sparing normal cells.