| The morbidity and mortality of the lung cancer has become the fastest-growing in a variety of cancers, which seriously harm to human's health and life. China's mortality rate of lung cancer in the city now ranks first in cancer mortality. Non-small cell lung cancer (NSCLC) accounts for 85% of lung cancer patients, associated with poor prognosis and high death rate.The majority of patients belonged to the later period of caancer process when diagnosed. At different stages of development of the disease should be taken to a different treatment strategies.Surgical treatment aimed at early-stage of focal disease, while palliative treatment targeted of metastatic lung cancer. Drug therapy is one of the pillars of its treatment. The key point in enhancing the effect of treatment may be how to choose a relatively sensitive drug to avoid drug resistance.Tumor resistance and drug toxicity remains a problem in clinical cancer chemotherapy. Resolution of this problem will certainly improve the treatment of cancer patients and extend the life of patients.Small molecular compounds are usually formed by several or dozens of atoms, whose molecular weight are in the dozens to hundreds (general molecular weight below 500). In accordance with the role of anti-NSCLC principle and source categories, small molecular compounds may include alkylating agents, anti-metabolism drugs, natural source of anti-tumor small molecules, anti-tumor metal complexes, as well as small molecular tyrosine kinase inhibitors and so on.The research and development of most synthetic chemical anti-NSCLC drugs are based on natural active ingredients as the leading compound. Based on natural active anti-cancer ingredients, large-scale, rapid screening of leading compounds and using computer simulation and bionic design to carry out structural modification of the transformation of natural products will be a hotspot of antitumor drugs during the current and future period of time. Anti-NSCLC chemotherapy herbal and complementary medicine which are commonly used in the current clinical treatment include podophyllotoxin, paclitaxel, camptothecin, vincristine, resveratrol, polyphenols and so on.Small molecular tyrosine kinase inhibitors which used in targeted therapy are developed from the molecular mechanism. Therefore, compared with traditional drugs, they have better selectivity and fewer side effects.Using structure-based targeted design strategy to design compounds will increase the hit rate of active compounds and reduce the cost of the synthesis and screening of a large number of compounds。Opposed to the traditional drug discovery methods based on natural leading compounds, emerging combinatorial chemistry efficiently resolved the problem of the origins of the samples. Designing dioxane quinazoline compound libraries as a new EGFR tyrosine kinase inhibitor libraries, using combinatorial chemistry and anti-NSCLC pharmacological screening, will comply rapid and efficient discovery of active anti-NSCLC compounds.In this paper, anticancer activity and mechanism of several small molecules (from plants and target-designed combinatorial chemistry libraries) on non-small cell lung cancer A549 was studied, hoping to find more potential and specific small molecules.1 Anti-tumor effects of bakuchiol and mechanism on human lung adenocarcinoma A549 cell lineResveratrol (3,5,4-trihydroxy-trans-stilbene), a phytoalexin found in grapes, berries, and peanuts, is one of the most promising agents for cancer prevention.In view of the anti-NSCLC potential of resveratrol,it is expected to discover novel chemotherapeutic agents with resveratrol-like structure. Both of bakuchiol and resveratrol have a "4-hydroxystyryl moiety", which suggests that bakuchiol may also play an anti-tumor activity.Therefore, the antitumor activity of bakuchiol, an analogue of resveratrol, was explored on human lung adenocarcinoma cells.MTT assay revealed that IC50 of bakuchiol at 72 h was 9.58±1.12μmol/1,much lower than that of resveratrol (33.02±2.35μmol/1). Bakuchiol but not resveratrol elevated intracellular reactive oxygen species (ROS). Bakuchiol reduced mitochondrial membrane potential (Δψm) of cells in a concentration-and time-dependent manner, showing more potent effect than that of resveratrol.More apoptotic cells were induced by bakuchiol, compared with resveratrol. Subsequently, S-phase arrest, caspase 9/3 activaton, p53 and Bax up-regulation, as well as Bcl-2 down-regulation were observed in bakuchiol-treated A549 cells. The results point toward that S phase-related cell cycle regulation, more importantly ROS-related apoptosis might contribute to the anticancer properties of bakuchiol, which will strongly support the further development of bakuchiol against NSCLC.These results suggested that bakuchiol has selective cytotoxic activity on human lung adenocarcinoma A549 cell line but has hardly any cytotoxicity in other nontumorous cell lines. Bakuchiol showed more potent anti-tumor effect on A549 cells than that of resveratrol. S phase-related cell cycle regulation, more importantly ROS-related apoptosis might contribute to the anticancer properties of bakuchiol.2 Anti-tumor effects and mechanism of 2,3-disubstituted 8-arylamino-3H-imidazo [4,5-g] quinazoline derivative B-2 on human lung adenocarcinoma A549 cell line in vitro and in vivoQuinazoline heterocyclic compounds is a very important medicine core structure. Quinazoline derivatives have important biological activities. Chemists targeting designed 2,3-disubstituted 8-arylamino-3H-imidazo [4,5-g] quinazolines compound libraries as a new EGFR tyrosine kinase inhibitor libraries and constructed small molecule combinatorial chemistry library. Previously we screened the anti-cancer activity of these compounds on different cancer cell lines. Among them, B-2 (2-Isopropyl-3-butyl-8-(4-fluorophenylamino)-3H-imidazo [4,5-g] quinazoline possessed high anti-NSCLC activity.In this part, the antitumor effect of B-2 (compared with Iressa) against human lung adenocarcinoma A549 cell line in vitro and in vivo were investigated.Cytotoxicity assays revealed that B-2 was a potential antitumor compound with IC50 value of (4.30±0.30)μmol/L at 48 h in human lung adenocarcinoma A549 cell line. The MTT assay and morphological analysis revealed a remarkable difference between B-2-treated A549 and nontumorous cells.In hollow fiber, containing two different tumor cell lines, B-2 selectively inhibited A549 cells and was demonstrated strong antitumor activity with a dose-dependent effect in vivo. The cell inhibition rates against A549 cells in hollow fiber were (38.45±2.94)%, (60.43±1.86)% and (65.83±2.46)% respectively, at the doses of B-225,50 and 100 mg/kg; while cell inhibition rate of 100 mg/kg Iressa was (47.05±1.15)%.In the study with A549 xenograft models, B-2 was administrated orally once a day for five 5 days/wk for 3 weeks. The inhibition rates were 48.69%,85.50% and 86.45%, respectively, at the doses of B-2 50,100 and 150 mg/kg. The treatment effect of B-2 is better than Iressa at the same dose (100 mg/kg). No significant effect on body weight of nude mice was observed after B-2 treatment.However, B-2 exhibited weaker epithelial growth factor receptor (EGFR) ligand-binding affinity compared with its parent compound Iressa according to the docking results and EGFR PTK assay. Administration of B-2 for 24 h caused a concentration dependent increase in the proportion of cells in the G1 phase in comparison with control cultures. B-2 increased the protein levels of p53, p27K1P1 and pRb while decreased the expression of cyclin-dependent kinase 4 (CDK4) and cyclin Dl.After 6 h treatment,1～25μmol/L B-2 lowered mitochondrial transmembrane potential presented as green fluorescence in a dose-dependent manner, indicating a dose-dependent decrease of the mitochondrial transmembrane, proved that B-2-induced early stage depolarization of the mitochondrial transmembrane followed apoptosis. After incubation with B-2 for 36 h, demonstration of apoptosis was shown by annexin V and propidium Iodide staining for apoptosis. The apoptotic rates were (6.79±1.11)%, (14.58±3.53)% and (50.25±11.34)%, respectively, at the concentrations of B-2 1,5 and 25μmol/L. Then after 48 h treatment of B-2, AO-EB staining showed a number of cells exhibited a flattened polygonal morphology, and partial cells showed morphological features of apoptosis.In addition, B-2-induced death of A549 cells were identified by characteristics of apoptosis including Cytochrome C release and huge increase of Bax/Bcl-2 ratio. These events were accompanied by activation of caspase-3 and-9.These results suggested that B-2 demonstrated strong antitumor activity with a dose-dependent effect in vitro and in vivo on human lung adenocarcinoma A549 cell line. Inhibition of cell cycle progression and induction of apoptotic cell death contributed to the anti-NSCLC effects of B-2.Summary1. Bakuchiol has selective cytotoxic activity on human lung adenocarcinoma A549 cell line but has hardly any cytotoxicity in other nontumorous cell lines. Bakuchiol showed more potent anti-tumor effect on A549 cells than that of resveratrol. S phase-related cell cycle regulation, more importantly ROS-related apoptosis might contribute to the anticancer properties of bakuchiol.2. B-2 demonstrated strong antitumor activity with a dose-dependent effect in vitro and in vivo on human lung adenocarcinoma A549 cell line. Inhibition of cell cycle progression and induction of apoptotic cell death contributed to the anti-NSCLC effects of B-2. |
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