The gingival epithelium is becoming known as a regulator of the oral innate immune responses to a variety of insults such as bacteria and chemicals, including those chemicals found in cigarette smoke. We investigated the effects of whole cigarette smoke on cell-surface-expressed Toll-like receptors (TLR)-2, −4 and −6, human β-defensin (HBD) and proinflammatory cytokine expression and production in primary human gingival epithelial cells. Whole cigarette smoke was shown to increase TLR2, TLR4 and TLR6 expression. Cigarette smoke led to ERK1/2, p38 and JNK phosphorylation in conjunction with nuclear factor-κB (NFκB) translocation into the nucleus. TLR expression following cigarette smoke exposure was down regulated by the use of ERK1/2, p38, JNK MAP kinases, and NFκB inhibitors, suggesting the involvement of these signaling pathways in the cellular response against cigarette smoke. Cigarette smoke also promoted HBD2, HBD3, IL-1β, and IL-6 expression through the ERK1/2 and NFκB pathways. Interestingly, the modulation of TLR, HBD, and cytokine expression was maintained long after the gingival epithelial cells were exposed to smoke. By promoting TLR, HBDs, and proinflammatory cytokine expression and production, cigarette smoke may contribute to innate immunity dysregulation, which may have a negative effect on human health.
Vascular endothelial growth factor receptor-2 (VEGFR-2) plays a critical role in cancer angiogenesis. Inhibition of VEGFR-2 activity proved effective suppression of tumour propagation. Accordingly, two series of new 3-methylquinoxaline derivatives have been designed and synthesised as VEGFR-2 inhibitors. The synthesised derivatives were evaluated
in vitro
for their cytotoxic activities against MCF-7and HepG2 cell lines. In addition, the VEGFR-2 inhibitory activities of the target compounds were estimated to indicate the potential mechanism of their cytotoxicity. To a great extent, the results of VEGFR-2 inhibition were highly correlated with that of cytotoxicity. Compound
27a
was the most potent VEGFR-2 inhibitor with IC
50
of 3.2 nM very close to positive control sorafenib (IC
50
= 3.12 nM). Such compound exhibited a strong cytotoxic effect against MCF-7 and HepG2, respectively with IC
50
of 7.7 and 4.5 µM in comparison to sorafenib (IC
50
= 3.51 and 2.17 µM). In addition, compounds
28
,
30f
,
30i
, and
31b
exhibited excellent VEGFR-2 inhibition activities (IC
50
range from 4.2 to 6.1 nM) with promising cytotoxic activity. Cell cycle progression and apoptosis induction were investigated for the most active member
27a
. Also, the effect of
27a
on the level of caspase-3, caspase-9, and BAX/Bcl-2 ratio was determined. Molecular docking studies were implemented to interpret the binding mode of the target compounds with the VEGFR-2 pocket. Furthermore, toxicity and ADMET calculations were performed for the synthesised compounds to study their pharmacokinetic profiles
A new series of 5,5-diphenylhydantoin derivatives containing benzylidene or isatin (4–19) was synthesized. Their anticancer activity against HeLa, a cervical cancer cell line, A549, a lung cancer cell line, and MDA-MB-231, a breast cancer cell line, was evaluated. Compounds 13, 16, 17 and 18 exhibited potent anticancer activity with average IC50 values against the tested cell lines of 109, 59, 81 and 113 μM, respectively. Compound 16 showed potent EGFR and VEGFR2 inhibitory activity with IC50 values of 6.17 and 0.09 μM, respectively. In addition, compound 16 induced caspase-dependent apoptosis and reactive oxygen species (ROS) production at 5 and 10 μM. Moreover, a molecular docking simulation was performed for compound 16 and sunitinib to predict the protein-ligand interactions with the active site of VEGFR2.
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