ABSTRACT
Objective: To investigate the regulatory role of extracellular vesicles (EVs) carrying ATP binding cassette transporter G2 (ABCG2) on the drug resistance of lung adenocarcinoma cells and the relevant molecular mechanisms. Methods: A549 cells, human lung adenocarcinoma cells, were used to form cisplatin (or cis-Diaminedichloroplatinum, CDDP)-resistant lung adenocarcinoma cells, i.e., A549/CDDP cells. EVs from A549 and A549/CDDP cells were extracted by gradient centrifugation method and were hence named EVs 1 and EVs 2, respectively. The A549 cells were treated with EVs 1 and EVs 2 for 48 hours, and the cells were named A549-EVs 1 and A549-EVs 2 cells, respectively. A549/ ABCG2 cells were established by transfecting A549 cells with pCDNA3.1- ABCG2 recombinant plasmids. On the other hand, A549 cells transfected with empty vectors were named A549/pCDNA3.1 cells. MTT assay was conducted to calculate the 24-hour cell drug resistance index for CDDP. The ABCG2 gene expression in cells and EVs were assessed with real-time PCR. A549 and A549-EVs 2 cells were transplanted subcutaneously into nude mice, which were labeled the control group and the experimental group accordingly. After tumor formation, 3 mg/kg CDDP was intraperitoneally injected once a week for two times. The ABCG2 gene expression of subcutaneous transplanted tumor cells was examined by real-time PCR. The cell apoptosis rate of subcutaneous transplanted tumor cells was examined by flow cytometry. Results: Using the parental A549 cells as reference, the 24-h CDDP-resistance indexes of 549/CDDP, A549/ ABCG 2, A549/pCDNA3.1, A549-EVs 1, A549-EVs 2 cells were 7.17, 10.06, 1.02, 1.19 and 5.40, respectively. When comparing the ABCG2 gene expression levels in all cells and EVs, the findings were higher in A549/CDDP cells than those inA549 cells, higher in A549/ ABCG2 cells than those in A549/pCDNA3.1 or A549 cells, higher in EVs 2 than those in EVs 1, and higher in A549-EVs 2 than those in A549-EVs 1 cells ( P<0.01) . The volume of transplanted tumor and the ABCG2 gene expression level in the experimental group were higher than those in the control group, while the apoptosis rate was lower than that in the control group ( P<0.01). Conclusion: EVs carrying ABCG2 gene can regulate the drug resistance of lung adenocarcinoma cells.
Subject(s)
Adenocarcinoma of Lung , Adenocarcinoma , Extracellular Vesicles , Lung Neoplasms , Adenocarcinoma/genetics , Adenocarcinoma/pathology , Adenocarcinoma of Lung/genetics , Animals , Cell Line, Tumor , Cisplatin/pharmacology , Drug Resistance, Neoplasm/genetics , Extracellular Vesicles/metabolism , Extracellular Vesicles/pathology , Lung Neoplasms/pathology , Mice , Mice, NudeABSTRACT
BACKGROUND AND AIM: Assessing the average survival rate of patients with hepatocellular carcinoma (HCC) after hepatectomy is important for making critical decisions in everyday clinical practice. The present study aims to develop and validate a nomogram for assessing the overall survival probability for such patients. METHODS: The putative prognostic indicators for constructing the nomogram were identified using multivariable Cox regression and model selection based on the Akaike information criterion. The nomogram was subjected to internal and external validation. The nomogram endpoints were death within 1, 3, and 5 years. RESULTS: A consecutive sample of 522 HCC patients who underwent potentially curative hepatectomy was retrospectively analyzed. Age, Barcelona clinic liver cancer (BCLC) stage, tumor size, alanine transaminase, alpha fetal protein, and serum prealbumin were included in the final model. The nomogram's discriminative ability was good in the training set (C-index was 0.74 for 1 year, 0.73 for 3 years, 0.70 for 5 years) and was validated using both an internal bootstrap method (C-index was 0.73 for 1 year, 0.72 for 3 years, 0.69 for 5 years) and an external validating set (C-index was 0.72 for 1 year, 0.72 for 3 years, 0.69 for 5 years). The calibration plots for the endpoints showed optimal agreement between the nomogram's assessment and actual observations. CONCLUSIONS: The nomogram (an Excel-based tool) can be useful for assessing the probability of survival at 1, 3, and 5 years in patients with HCC after hepatectomy.
