21 October 2016 : Laboratory Research
Long Non-Coding RNA (lncRNA) Urothelial Carcinoma-Associated 1 (UCA1) Enhances Tamoxifen Resistance in Breast Cancer Cells via Inhibiting mTOR Signaling Pathway
Chihua WuABCDEF, Jing LuoABCDEFGDOI: 10.12659/MSM.900689
Med Sci Monit 2016; 22:3860-3867
Abstract
BACKGROUND: Long non-coding RNA (lncRNA) UCA1 is an oncogene in breast cancer. The purpose of this study was to investigate the role of UCA1 in tamoxifen resistance of estrogen receptor positive breast cancer cells.
MATERIAL AND METHODS: Tamoxifen sensitive MCF-7 cells were transfected for UCA1 overexpression, while tamoxifen resistant LCC2 and LCC9 cells were transfected with UCA siRNA for UCA1 knockdown. qRT-PCR was performed to analyze UCA1 expression. CCK-8 assay, immunofluorescence staining of cleaved caspase-9, and flow cytometric analysis of Annexin V/PI staining were used to assess tamoxifen sensitivity. Western blot analysis was performed to detect p-AKT and p-mTOR expression.
RESULTS: LncRNA UCA1 was significantly upregulated in tamoxifen resistant breast cancer cells compared to tamoxifen sensitive cells. LCC2 and LCC9 cells transfected with UCA1 siRNA had significantly higher ratio of apoptosis after tamoxifen treatment. UCA1 siRNA significantly decreased the protein levels of p-AKT and p-mTOR in LCC2 and LCC9 cells. Enforced UCA1 expression substantially reduced tamoxifen induced apoptosis in MCF-7 cells, while rapamycin treatment abrogated the protective effect of UCA1.
CONCLUSIONS: UCA1 upregulation was associated with tamoxifen resistance in breast cancer. Mechanistically, UCA1 confers tamoxifen resistance to breast cancer cells partly via activating the mTOR signaling pathway.
Keywords: tamoxifen, TOR Serine-Threonine Kinases
Editorial
01 April 2024 : Editorial
Editorial: Forty Years of Waiting for Prevention and Cure of HIV Infection – Ongoing Challenges and Hopes for Vaccine Development and Overcoming Antiretroviral Drug ResistanceDOI: 10.12659/MSM.944600
Med Sci Monit 2024; 30:e944600
In Press
15 Apr 2024 : Laboratory Research
The Role of Copper-Induced M2 Macrophage Polarization in Protecting Cartilage Matrix in OsteoarthritisMed Sci Monit In Press; DOI: 10.12659/MSM.943738
07 Mar 2024 : Clinical Research
Knowledge of and Attitudes Toward Clinical Trials: A Questionnaire-Based Study of 179 Male Third- and Fourt...Med Sci Monit In Press; DOI: 10.12659/MSM.943468
08 Mar 2024 : Animal Research
Modification of Experimental Model of Necrotizing Enterocolitis (NEC) in Rat Pups by Single Exposure to Hyp...Med Sci Monit In Press; DOI: 10.12659/MSM.943443
18 Apr 2024 : Clinical Research
Comparative Analysis of Open and Closed Sphincterotomy for the Treatment of Chronic Anal Fissure: Safety an...Med Sci Monit In Press; DOI: 10.12659/MSM.944127
Most Viewed Current Articles
17 Jan 2024 : Review article
Vaccination Guidelines for Pregnant Women: Addressing COVID-19 and the Omicron VariantDOI :10.12659/MSM.942799
Med Sci Monit 2024; 30:e942799
14 Dec 2022 : Clinical Research
Prevalence and Variability of Allergen-Specific Immunoglobulin E in Patients with Elevated Tryptase LevelsDOI :10.12659/MSM.937990
Med Sci Monit 2022; 28:e937990
16 May 2023 : Clinical Research
Electrophysiological Testing for an Auditory Processing Disorder and Reading Performance in 54 School Stude...DOI :10.12659/MSM.940387
Med Sci Monit 2023; 29:e940387
01 Jan 2022 : Editorial
Editorial: Current Status of Oral Antiviral Drug Treatments for SARS-CoV-2 Infection in Non-Hospitalized Pa...DOI :10.12659/MSM.935952
Med Sci Monit 2022; 28:e935952