TY - JOUR
AR - RCO-2021-1-101
TI - Effects of Low Dose Fractional Radiation on Chemosensitivity of Gemcitabine-Resistant Human Pancreatic Cancer SW1900/GZ Cell
AU - Yanda , LU
AU - Fengxiang , Han
AU - Chunxiang , Luo
AU - Fen , Huang
AU - Donghua , Xie
AU - Huamao , Sun
AU - Weisi , Chen
AU - Danni , XU
JO - Radiotherapy and Clinical Oncology
PY - 2021
DA - Thu 11, Mar 2021
SN - 2674-2497
DO - http://dx.doi.org/10.31487/j.RCO.2021.01.01
UR - https://www.sciencerepository.org/effects-of-low-dose-fractional-radiation-on-chemosensitivity_RCO-2021-1-101 
KW - Pancreatic cancer, drug resistance, gemcitabine, low dose fractionated radiation (LDFRT)
AB - Objective: To investigate whether low-dose fractionated radiation (LDFRT) could enhance gemcitabine sensitivity in drug-resistant human pancreatic cancer SW1900/GZ cell, and to further explore the underlying mechanism.
Methods: Gemcitabine-resistant human pancreatic cancer SW1900 cell line (SW1900/GZ) was induced by high concentration gemcitabine intermittent shock in vitro. The cell counting kit 8 (CCK8) was used to determine SW1900/GZ cell lines. SW1900/GZ cells were divided into six groups as follows: control, LDFRT, high dose radiation (HDRT), gemcitabine (GEM), low dose fractional radiation plus gemcitabine (LDFRT+ GEM) and high dose radiation plus gemcitabine (HDRT+ GEM) groups. The rate of apoptosis was determined by flow cytometry (FCM). Protein levels of multidrug resistance gene (MDR) and multidrug resistance-related protein gene (MRP) were examined by Western blotting.
Results: The results of CCK8 test showed that the half-maximal inhibitory concentration (IC50) of non-drug-resistant cell line SW1900 and drug-resistant cell line SW1990/GZ were 230.4ng/ml and 856.6ug/ml respectively. The IC50 of SW1990/GZ was 3700 times more than the former. LDFRT significantly promoted apoptosis in SW1900 cells. Moreover, in the LDFRT group, protein levels of MDR and MRP were markedly decreased.
Conclusion: This study established an effective gemcitabine-resistant cell line SW1900 of human pancreatic cancer (SW1900/GZ cell line). LDFRT sensitizes resistant SW1900/GZ pancreatic cancer cell to gemcitabine through down-regulation the expression of MDR and MPR proteins.