ABSTRACT
Background and purpose: Gemcitabine (GEM) is a first-line chemotherapy drug for pancreatic cancer. With the emergence of clinical drug resistance, the efficacy of chemotherapy has been greatly reduced, while the expression of secretory clusterin (sCLU) was closely related to chemotherapy resistance in multiple tumors. This study aimed to explore the effects of secretory clusterin on oxidative damage in MIA PaCa-2 cells treated by GEM and preliminary mechanism of resistance to GEM. Methods: MIA PaCa-2 was exposed to GEM and sCLU intervened groups with different concentrations (0, 0.63, 1.25, 2.50, 5.00 and 10.0 μg/mL) for 24 hours. The intervened concentration of GEM was 5.4 μmol/L. The inhibition rates of cell proliferation were determined by CCK-8. Cell reactive oxygen species (ROS) was measured by dichloro-dihydro-fluorescein diacetate (DCFH-DA) method. Superoxide dismutase (SOD) activity and catalase (CAT) activity were measured by their corresponding assay kits respectively. Results: Compared with the negative control group (0 μg/mL), the inhibition rates of the GEM groups and sCLU intervened groups were significantly increased (P＜0.05) in a distinct dose-effect manner. At a low concentration of 0.63 μg/mL, the inhibition rates of the GEM groups were higher than those of the sCLU intervened groups, while the trend was reversed in high concentration range. Compared with the negative control group (0 μg/mL), the intracellular ROS levels, SOD and CAT activity of the GEM and sCLU intervened groups significantly increased (P＜0.05). ROS levels presented a distinct dose-effect relationship while the SOD and CAT activities increased first and then decreased along with the increase of GEM concentrations. The ROS levels of the GEM group were lower than those of the sCLU intervened group at the same dose (P＜0.05). The SOD activities of the GEM group were higher than those of the sCLU intervened group, while the CAT activities were opposite at the concentrations of 5.00 and 10.00 μg/mL (P＜0.05). Conclusion: GEM exposure can inhibit the growth of MIA PaCa-2 cells. After GEM exposure, the ROS levels, SOD and CAT activity of MIA PaCa-2 cells can be changed by sCLU intervention. GEM resistance could be regulated by sCLU through oxidative damage effect.
ABSTRACT
Aim To investigate the expression pattern of secretory clusterin ( sCLU) in lung tissues and plas-ma of rats with pulmonary arterial hypertension ( PAH) induced by monocrotaline ( MCT ) . Methods Thirty male SD rats were randomly divided into control group ( n=6 ) and MCT group ( n=24 ) , and were intraper-itoneally injected 60 mg·kg-1 MCT for MCT group or equal volume normal saline for control group. Real time PCR and Western blot were performed to investi-gate the expression pattern of sCLU mRNA and protein in rat lungs 1 ( n=6 ) , 2 ( n=6 ) , 3 ( n=6 ) and 4 (n=6) weeks after MCT injection, respectively. Im-munohitochemistry was performed to determine the lo-calization of sCLU in rat lungs. Enzyme linked immu-nosorbent assay was performed to detect the concentra-tion of sCLU in rat plasma. Results Expression of sCLU mRNA and protein elevated significantly in time-dependent manners in rat lungs of MCT group, and sCLU mainly localized in the cytoplasma and extracel-lular matrix of cells in pulmonary arterioles. Further-more, sCLU plasma levels were significantly elevated with the progression of PAH and had positive correla-tions with pulmonary hemodynamic indices and right ventricular hypertrophic index. Conclusion sCLU was significantly elevated in MCT induced PAH rat lungs and plasma, and it may participate in the pulmo-nary vascular remodeling process. Moreover, plasma sCLU may be a potential biomarker for PAH.
ABSTRACT
Background and purpose: Primary study showed that clusterin was associated with tumorigenicity. The goal of the study is to investigate the role of secretory clusterin in non-small cell lung cancer cell A549/H460. Methods: The lung cancer cell A549/H460 was treated with purified secretory clusterin, the Boyden Chamber migration assay was used to detected the migration of the lung cancer cell;the CCK8 assay was used to detected the growth of the cells;microRNA expression spectrum in H460 treated with secretory clusterin was analyzed, after that, we used the real-time florescence quantification detected the expression of microRNA in H460, and the biological function of microRNA molecular mechanisms of secretory clusterin was analyzed. Results: Secretory clusterin promoted the migration in A549/H460 (P<0.000 1);Secretory clusterin inhibited the growth in H460/A549 (P<0.000 1);MicroRNA-302b-3p, microRNA-23a-5p and microRNA-101-5p was overexpressed in H460 when treated with secretory clusterin. Conclusion:Secretory clusterin could promote the migration and inhibit the growth of lung cancer cell;It could change the microRNA expression spectrum as well. Our studies revealed that secretory clusterin could be used as a tool for further study, and it is a potential target in the treatment of lung cancer.