280P - The Study of Drug Resistant in Bladder Cancer and its Modulation by Phytochemicals

Date 17 December 2016
Event ESMO Asia 2016 Congress
Session Poster lunch
Topics Cytotoxic agents
Cancer biology
Urothelial Cancers
Presenter Jun Zhuo
Authors J.R. Zhuo
  • Pathyolog, National Defense Medical Center, 11490 - Taipei/TW

Abstract

Background

Bladder cancer is one of the top ten cancers and over 50% patients usually experience tumor recurrence. Drug resistance (DR) is the most common cause treatment failure and obstacle of gemcitabine (GCB) clinically. Phytochemicals are considered as therapeutic agents in downregulated the DR in cancer. Hence, we suppose that phytochemicals could overcome and prevent the DR of urothelial cell carcinoma (UCC).

Methods

GCB-DR UCC cells will be obtained by long-term culture of UCC cells, T24 under low concentration of GCB. The drug tolerability of GCB-DR cells will be confirmed by MTT assay. The DR-related (ABC families) and apoptotic pathways (caspase-3, bcl-2, and cleaved PARP) will be elucidated by Q-PCR, western blot, and flow cytometric methods individually. Subsequently, the effect of various phytochemicals to the GCB-DR cells will be elucidated by MTT assay first and related signal pathway changes will be clarified using Q-PCR, western blot, and flow cytometric methods.

Results

We successfully cultured GCB resistant UCC cell line, T24-GCB and verified drug sensitivity of GCB by the MTT assay which the half maximal inhibitory concentration (IC50) was higher than parental T24 cells (157.1 ± 25.2 vs 0.4 ± 0.4 nM, p < 0.01).We found mRNAs performance of ABCC2 was increased (1.88 ±0.49 fold, p = 0.065) but ABCB1 (0.01 ± 0.01 fold, p < 0.01) was conversely significant decreased in T24-GCB cells by Q-PCR method. We found drug resistance protein expressions were similar to mRNA expressions, ABCC2 was significant increased (1.12 ± 0.03 fold, p < 0.05) but ABCB1 (0.20 ± 0.09 fold, p < 0.01) was conversely significant decreased in T24-GCB by WB method. The GCB IC50 was steady in variant passage (p1, 157.1 ± 25.2; p42, 168.3 ± 1.0 nM, p = 0.48) of GCB exposed T24-GCB cells. The cytotoxicity of T24-GCB cells was enhanced in quercetin 10 μM (25.4% ± 4.0% vs 20.7% ± 3.5%, p < 0.01) and 30 μM (20.7% ± 3.4% vs 8.0% ± 1.0%, p < 0.01) treatment when compared to T24 cells.

Conclusions

GCB-DR was caused by upregulating of ABCC2 and quercetin could enhance the cytotoxicity in T24-GCB cells. But the underlying mechanisms of cytotoxicity enhanced by quercetin, downregulated of ABCB1 mRNA and protein, and combination efficacy of GCB with quercetin in T24-GCB cells need to evaluate in further study.

Clinical trial indentification

Non