Schedule-dependent cytotoxic synergism of pemetrexed and erlotinib in BXPC-3 and PANC-1 human pancreatic cancer cells

Abstract

Abstract. Previous studies have shown that both pemetrexed, a cytotoxic drug, and erlotinib, an epidermal growth factor receptor tyrosine kinase inhibitor (EGFR-TKI), inhibit the cell growth of pancreatic cancer cells. However, whether they exert a synergistic antitumor effect on pancreatic cancer cells remains unknown. The present study aimed to assess the synergistic effect of erlotinib in combination with pemetrexed using different sequential administration schedules on the proliferation of human pancreatic cancer BXPC-3 and PANC-1 cells and to probe its cellular mechanism. The EGFR and K-ras gene mutation status was examined by quantitative PCR high-resolution melting (qPCR-HRM) analysis. BXPC-3 and PANC-1 cells were incubated with pemetrexed and erlotinib using different administration schedules. MTT assay was used to determine cytotoxicity, and cell cycle distribution was determined by flow cytometry. The expression and phosphorylation of EGFR, HER3, AKT and MET were determined using Western blotting. Both pemetrexed and erlotinib inhibited the proliferation of BXPC-3 and PANC-1 cells in a dose-and time-dependent manner in vitro. Synergistic effects on cell proliferation were observed when pemetrexed was used in combination with erlotinib. The degree of the synergistic effects depended on the administration sequence, which was most obvious when erlotinib was sequentially administered at 24-h interval following pemetrexed. Cell cycle studies revealed that pemetrexed induced S arrest and erlotinib induced G 0 /G 1 arrest. The sequential administration of erlotinib following pemetrexed induced S arrest. Western blot analyses showed that pemetrexed increased and erlotinib decreased the phosphorylation of EGFR, HER3 and AKT, respectively. However, both pemetrexed and erlotinib exerted no significant effects on the phosphorylation of c-MET. The phosphorylation of EGFR, HER3 and AKT was significantly suppressed by scheduled incubation with pemetrexed followed by erlotinib, but not by concomitant or sequential incubation with erlotinib followed by pemetrexed. In summary, our results demonstrated that the combined use of erlotinib and pemetrexed exhibited a strong synergism in BXPC-3 and PANC-1 cells. The inhibitory effects were strongest after sequential administration of pemetrexed followed by erlotinib. The synergistic effects may be related to activation of the EGFR/HER3/AKT pathway induced by pemetrexed.

Stromal mesenchymal stem cells facilitate pancreatic cancer progression by regulating specific secretory molecules through mutual cellular interaction

“…Since AREG binds either EGFR homodimer (EGFR/EGFR) or EGFR/ERBB2 heterodimer, EGFR specific inhibitors may be effective for PDACs' treatment if escaping the stroma barrier in vivo . In this subject, Wang L et al 22 demonstrated that Erlotinib, an EGFR specific chemical inhibitor, showed marked anti-cancer functions in BxPC3 cells, which possess no mutation of EGFR. In addition, Larbouret C et al 23 found that targeting approach to EGFR/HER2 heterodimer on PDACs using the combination of Cetuximab (therapeutic anti-EGFR antibody) with Trastuzumab (therapeutic anti-HER2 antibody) produced remarkable tumor suppressing effects.…”

Development of Parvifloron D-Loaded Smart Nanoparticles to Target Pancreatic Cancer

“…Considering some previously published results such as X. Yu et al (IC 50 = 0.2 μM to gemcitabine in BxPC3 cell line) [30], A. Singh et al (IC 50 = 123.9 μM to gemcitabine in PANC-1 cell line) [31], A. Acuna et al (IC 50 = 46.5 μM to PH-427 in BxPC3 cell line) [32], S. Mukai et al (IC 50 = 19.5 μM and 20.4 μM to gefitinib in BxPC3 and PANC-1 cell lines, respectively) [33], L. Wang et al (IC 50 = 39.86 μM and 83.76 μM to Pemetrexed in BxPC3 and PANC-1 cell lines, respectively) [34] or even A. Wright et al (IC 50 = 70.9 μM and 22.8 μM to Aphrocallistin in BxPC3 and PANC-1 cell lines, respectively) [35], we can suggest that Parvifloron D has a higher cytotoxic potential (IC 50 = 0.15 ± 0.05) to these pancreatic tumor cells.…”

EGFR‐rich extracellular vesicles derived from highly metastatic nasopharyngeal carcinoma cells accelerate tumour metastasis through PI3K/AKT pathway‐suppressed ROS

“…EGFR is the cell surface tyrosine kinase receptor, and activated EGFR recruits and phosphorylates cytoplasmic signalling molecules, thus initiating downstream signalling cascades including JAK/STATs, MAPK/ERK, and PI3K/AKT, to promote tumour cell proliferation, invasion and distant metastasis (Hynes & Lane, 2005; Wang et al., 2011a; Wang, Zhu, Zhang, & Zhang, 2011). However, despite the intersection of signalling activation in different tumours, there may be a preference for EGFR‐activated signalling transduction for the metastasis of tumour cells.…”