Stability of infliximab in polyvinyl chloride bags.

PURPOSE: The stability of prepared infusions of the tumor necrosis factor (TNF)-α agent infliximab after storage for up to two weeks was investigated. METHODS: To determine the feasibility of liberalized expiration dating of infliximab (current recommendations call for the infusion of prepared doses within three hours), the stability of diluted infliximab stored in polyvinyl chloride (PVC) bags at 4 °C for up to 14 days was evaluated. A known quantity of TNF-α was combined with infliximab test samples in PVC bags for one hour; immediately after the reaction period and after 7 and 14 days of storage, the residual amount of TNF-α (an indirect measure of the drug's biological activity) was analyzed via a validated enzyme-linked immunosorbent assay (ELISA). RESULTS: The mean ± S.D. amount of TNF-α consumed by infliximab was calculated to be 24.5 ± 5.6 pg/mL at baseline, 29.0 ± 4.4 pg/mL at 7 days, and 24.8 ± 17.3 pg/mL at 14 days. At all evaluated time points, ELISA results indicated that 19-24% of the original TNF-α had been consumed by infliximab (mean ± S.D. consumption: 19.6% ± 4.5% at baseline, 23.2% ± 3.5% at 7 days, and 19.8% ± 13.8% at 14 days). CONCLUSION: Infliximab, when prepared at a concentration of 400 µg/mL in 0.9% sodium chloride injection, incurred no loss of biological activity when stored for up to 14 days at 4 °C in PVC bags. Changing infliximab preparation practices may improve clinic efficiency by reducing patient dissatisfaction with long wait times for infusions and avoiding costly waste.

Isolation and characterization of erlotinib-resistant human non-small cell lung cancer A549 cells.

Erlotinib, an epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor, is an effective therapy for non-small cell lung cancer (NSCLC). However, resistance to erlotinib reduces its efficacy. To investigate the basis of erlotinib resistance, we isolated erlotinib-resistant human NSCLC A549 cells, termed A549/ER cells. The A549/ER cells were found to be resistant to erlotinib, as well as paclitaxel and gemcitabine. We then performed a PCR array to investigate the resistance to erlotinib in A549/ER cells. EGFR expression in A549/ER cells was decreased compared to A549 cells. The expression of fibroblast growth factor 2 (FGF2) and p21 in A549/ER was increased when compared to A549 cells. Our results suggest that the down-regulation of EGFR and up-regulation of FGF2 is related to resistance to erlotinib in A549/ER cells.

Isolation and characterization of gemcitabine-resistant human non-small cell lung cancer A549 cells.

Gemcitabine is an effective chemotherapy against non-small cell lung cancer (NSCLC). However, resistance to gemcitabine reduces its efficacy. We have isolated gemcitabine-resistant human non-small cell lung cancer A549 cells, termed A549/GR cells. A549/GR cells were resistant to gemcitabine as well as paclitaxel and docetaxel but not carboplatin and irinotecan. The expression level of multidrug resistance protein 7 (MRP7) in A549/GR cells was higher than that in A549 cells, and the inhibitor of MRP7 by cepharanthine increased the sensitivity to gemcitabine in A549/GR cells. These findings indicate that cepharanthine reversed gemcitabine resistance. To determine predictive molecular markers of gemcitabine resistance for more effective treatment of these tumors, we performed PCR array. We identified that CDKN1A/p21, CYP3A5, microsomal epoxide hyrolase 1 (EPHX1) and ABCC6 (MRP6) were up-regulated >5-fold in A549/GR cells. Gemcitabine also induced the expression of p21 and CYP3A5 in A549 cells. A better understanding of the characterization and mechanism of the resistance to gemcitabine in A549/GR cells may help identify agents that reverse clinical gemcitabine resistance in NSCLC.

Establishment and characterization of irinotecan-resistant human non-small cell lung cancer A549 cells.

Irinotecan (CTP-11) is a topoisomerase I inhibitor used in the treatment of colorectal cancer and non-small cell lung cancer (NSCLC). Despite an initial response to therapy, resistance to irinotecan reduces its efficacy. We isolated irinotecan-resistant human NSCLC A549 cells, termed A549/CTP-11R cells. A549/CTP-11R cells were resistant to irinotecan, as well as paclitaxel, gemcitabine and carboplatin. Curcumin, a nuclear factor-κB (NF-κB) inhibitor, increased the sensitivity to irinotecan of A549/CTP-11R cells. The expression level of Bcl-XL and X-linked inhibitor of apoptosis protein, target genes of NF-κB, in A549/CTP-11R cells was higher than that in A549 cells. Our result suggests that the addition of curcumin to irinotecan reverses irinotecan resistance in NSCLC.

Gemcitabine and paclitaxel suppress the production of vascular endothelial growth factor induced by deferoxamine in human non-small cell lung cancer A549 cells.

Vascular endothelial growth factor (VEGF) plays an important role in the process of angiogenesis in many types of cancer, including non-small cell lung cancer (NSCLC), and angiogenesis inhibitors and standard chemotherapy exhibit synergy though an unknown mechanism. We therefore hypothesized that cytotoxic chemotherapy influences VEGF production and analyzed VEGF production in an NSCLC A549 cell line after treatment with standard chemotherapy. Paclitaxel inhibited the production of VEGF in A549 cells, while cisplatin and erlotinib did not. Paclitaxel and gemcitabine inhibited deferoxamine (DFX) (known to mimic hypoxia)-induced VEGF production in A549 cells. Erlotinib also inhibited DFX-induced VEGF production in A549 cells slightly, while cisplatin did not. We subsequently examined the effect of the interaction between paclitaxel or gemcitabine and VEGF protein. Paclitaxel and gemcitabine did not directly affect the binding of VEGF. Since VEGF is known as one of the HIF-1 target genes, we examined the effect of paclitaxel and gemcitabine on HIF-1α levels induced by DFX in A549 cells. Paclitaxel and gemcitabine inhibited DFX-induced HIF-1α in A549 cells. These findings may be useful for future treatment schedules, including anti-cancer agents in NSCLC.