Integrin β1-mediated acquired gefitinib resistance in non-small cell lung cancer cells occurs via the phosphoinositide 3-kinase-dependent pathway.

The present study aimed to explore the role of integrin β1 and the relevant signaling pathways in acquired gefitinib resistance in non-small cell lung cancer (NSCLC). The inhibitory effects of gefitinib, with or without LY294002, on cellular proliferation were evaluated by 3-(4,5-dimethylthiazol-2-yl) 2,5-diphenyltetrazolium bromide assay. Cell cycle progression and apoptosis were analyzed by flow cytometry, while western blotting was used to evaluate the expression of EGFR, phosphorylated (phospho)-EGFR, protein kinase B (Akt), phospho-Akt, extracellular signal-regulated kinase (Erk) and phospho-Erk.

[Construction of RGD10-NGR9 dual-targeting superparamagnetic iron oxide and its magnetic resonance imaging features in nude mice].

Objective: To construct angiogenesis-specific RGD10-NGR9 dual-targeting superparamagnetic iron oxide nanoparticles, and to evaluate its magnetic resonamce imaging (MRI) features in nude mice and potential diagnostic value in tumor MRI.

Methods: Dual-targeting peptides RGD10-NGR9 were designed and synthesized. Ultrasmall superparamagnetic iron oxide (USPIO) nanoparticles were synthesized by chemical co-precipitation method and the surface was modified to be hydrophilic by coating with dextran.

[Effect of Wnt signaling suppression on gefitinib in non small cell lung cancer cell lines].

Objective: To explore the effect of Wnt signaling suppression on proliferation of non small cell lung cancer to gefitinib, and its related mechanisms.

Methods: PC9 and PC9/AB2 cells of both gefitinib sensitive and resistant were treated with different concentrations of gefitinib, and the proliferation index was measured using CCK8 kit. The members of Wnt signaling pathway were detected by Western blot.

Atypical chemokine receptor D6 inhibits human non-small cell lung cancer growth by sequestration of chemokines.

Chemokines and their receptors have been shown to play a vital role in lung cancer progression. D6 is an atypical chemokine receptor which is able to internalize and degrade chemokines. To investigate the potential role of D6 in lung cancer, we established D6-overexpressing A549 lung cancer cell lines by the transfection of human D6 cDNA.

[Small molecule inhibitor SB203580 enhances the antitumor effect of gefitinib in PC-9 and A549 lung cancer cell lines].

Objective: To detect the inhibitory effect of a p38MAPK inhibitor SB203580 in combination with gefitinib on lung adenocarcinoma cell line PC-9 cells and A549 cells, and its cellular and molecular mechanisms of action.

Methods: MTT test was used to detect the growth inhibition of PC-9 and A549 cells by SB203580 alone and in combination with gefitinib. Cell apoptosis and cell cycles were determined by flow cytometry.

[Drug resistance mechanism of non small cell lung cancer PC9/AB2 cell line with acquired drug resistance to gefitinib].

Objective: To study the drug resistance mechanism of non-small cell lung cancer (NSCLC) cell line PC9/AB2 with acquired drug resistance to gefitinib.

Methods: The human lung adenocarcinoma cell line PC9 was cultured in vitro, and was induced by MNNG to obtain the cell line PC9/AB2 with acquired drug resistance to gefitinib. The sensitivity of the cell line PC9 and PC9/AB2 to gefitinib was determined by MTT assay.

[Sensitivity of two cell lines with acquired resistance to gefitinib to several chemotherapeutic drugs].

Objective: To explore the sensitivity of tumor cell lines with acquired resistance to gefitinib to several chemotherapeutic drugs and provide preclinical basis of available chemotherapy regimens after failure of molecular targeted therapy.

Methods: Human lung adenocarcinoma cell lines PC9 and PC9/G with acquired resistance to gefitinib were cultured in vitro. The sensitivity to chemotherapeutic drugs and inhibition rate of cell proliferation was determined by MTT assay.

[Mutations in exon 19 of EGFR gene in non-small cell lung cancer from Chinese patients].

Objective: To investigate the mutations in exon 19 of epidermal growth factor receptor (EGFR) gene in non-small cell lung cancer from Chinese patients.

Methods: Genomic DNA was extracted from 72 lung cancer tissues. Then the exon 19 of EGFR gene was amplified by nested PCR and sequenced.