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Abstract P6-05-04: NEAT1 enhances drug sensitivity by inhibiting cancer stem-like cells in triple-negative breast cancer. Cancer Res 2019. [DOI: 10.1158/1538-7445.sabcs18-p6-05-04] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
Background: Accumulating evidence showed that long non-coding RNAs (lncRNAs) dysregulation is the hallmark of cancer. Nuclear paraspeckle assembly transcript 1 (NEAT1) has been reported to overexpress in many cancers, and promote cell growth and disease progression. However, the role of NEAT1 on drug sensitivity and stem-cell like property in triple-negative breast cancer is largely unknown.
Methods: LncRNA expression profile were compared between breast cancer patients and healthy individuals using lncRNA array. Large scale validation of NEAT1 expression in blood samples were performed by real-time PCR. Triple-negative breast cancer (TNBC) cells, MDA-MB-231 and its cisplatin resistance subline (MDA-MB-231/cis) were used. Stable transfection of cells with NEAT1 knockdown by shRNA, and evaluated single cell clonogenic assay, aldehyde dehydrogenase (ALDH) activity, CD44+/CD24- and other cancer stem cell (CSC) markers. Drug sensitivity assay, flow cytometry analysis, immunofluorescence staining and xenograft model were used to assess the functional role of NEAT1.
Results: Array data showed that NEAT1 was the top upregulated lncRNAs in the plasma of breast cancer patients. Consistent with the array data, validation of larger cohort of patients and healthy individuals (n=369) also demonstrated a higher expression of NEAT1 in breast cancer patients, in particular TNBC subtype. Knockdown of NEAT1 by shRNA sensitized breast cancer cells to cisplatin and taxol treatment. Cell proliferation and colony formation abilities were reduced with S-phase cell cycle arrest in shNEAT1 cells. Flow cytometry analysis revealed an induction of apoptosis with increased cleaved caspase-3. Cells expressing shNEAT1 abrogated ALDH activity, CD44+/CD24- subpopulation and expression of CSC markers (SOX2, NANOG and OCT4). More importantly, shNEAT1 cells retarded tumor growth in xenograft mice model and reduced CSC markers.
Conclusion: Taken together, NEAT1 expression is differentially expressed in breast cancer patients, and particularly higher in patients with TNBC. These findings suggest a potent therapeutic target to improve drug sensitivity in patients with TNBC.
Citation Format: Kwong A, Chen J, Siu J, Chuek I, Shin V. NEAT1 enhances drug sensitivity by inhibiting cancer stem-like cells in triple-negative breast cancer [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P6-05-04.
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Abstract P4-01-24: S100A11 is a diagnostic marker and promotes cancer progression for luminal breast cancer. Cancer Res 2019. [DOI: 10.1158/1538-7445.sabcs18-p4-01-24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
Background: S100A11, also known as calgizzarin, is a member of S100 calcium-binding protein family and is upregulated in various cancers including lung cancer, renal cell cancer, ovarian cancer and pancreatic cancer. Many studies have shown that S100A11 is related to cancer progression. However, the function of S100A11 in breast cancer remains largely unknown. In the present study, we aim to investigate the underlying mechanism(s) of S100A11 in cancer cell proliferation, invasion, migration, and evaluate the clinical association with breast cancer.
Methods: The mRNA expression level of S100A11 in plasma samples from breast cancer patients and normal control individuals was detected with quantitative real-time PCR. Knockdown of S100A11 using small interfering RNA (siRNA) in luminal breast cancer cells (MCF-7 and T-47D) were used to study the biological function of S100A11 for the progression of breast cancer. Cell proliferation ability was analysed with MTT assay and colony formation assay. Cell invasion ability was analysed with transwell invasion assay. Cell migration ability was detected by wound healing assay. Cell cycle distribution and apoptosis were determined by flow cytometry.
Results: The mRNA expression level of S100A11 was significantly increased in the plasma samples obtained from 182 breast cancer patients compared with 115 normal control individuals, and the area under curve was 0.83. In particular, higher expression was associated with luminal breast cancer subtype as well as respective cell lines. S100A11 siRNA effectively inhibited the proliferation, invasion, and migration abilities of MCF-7 and T-47D cells. Knockdown of S100A11 caused cell cycle G1 arrest and induced apoptosis. Silencing of S100A11 decreased the mRNA and protein expression levels of cyclin D1 and NF-κB p50 whereas increased the expression level of E-cadherin in MCF-7 and T-47D cells.
Conclusion: These results suggest that S100A11 is upregulated in breast cancer and promoted cell proliferation, invasion and migration in MCF-7 and T-47D cells through the upregulation of NF-κB p50 and cyclin D1. Thus, S100A11 may be a potential diagnostic marker for luminal breast cancer subtype and also a therapeutic target for breast cancer.
Citation Format: Kwong A, Wang J, Chen J, Siu MT, Chuek I, Shin V. S100A11 is a diagnostic marker and promotes cancer progression for luminal breast cancer [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P4-01-24.
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