Browsing Over 138 Presentations
22P - Therapeutic potential of connective tissue growth factor (CTGF) in triple-negative breast cancer (ID 104)
- H. Kim
- H. Kim
- S. Son
Abstract
Background
Matricellular proteins are a subset of extracellular matrix (ECM) proteins which are dynamically expressed and serve many regulatory roles. Among matricellular proteins, the CCN family, a group of secreted proteins are known to regulate cell adhesion, migration, proliferation, differentiation, apoptosis, survival, senescence, and gene expression. Connective tissue growth factor (CTGF), also known as CCN2, is a member of the CCN family. CTGF is known to have many roles in biological processes such as cell proliferation, migration, adhesion, and angiogenesis.
Methods
To investigate the function of CTGF in triple-negative breast cancer cells (TNBC), we silenced CTGF in TNBC cell lines using short hairpin RNA. Knockdown of CTGF was verified by western blot, qPCR, and immunostaining. The effect of CTGF knockdown on TNBCs was examined by cell proliferation assay, adhesion assay, migration assays, metabolism assays, and cell cycle analysis.
Results
Knockdown of CTGF decreased cell proliferation, adhesion, migration, glucose uptake, ATP production and lactate production. Since CTGF is a secreted protein, we gave recombinant human CTGF (rhCTGF) to the cells and found that rhCTGF induced activation of the Src/FAK/MAPK pathway and led to expression of proteins related to cell cycle progression. Also, when CTGF-specific antibodies were given to the cells, they expressed cytotoxicity by neutralizing the extracellular CTGF and decreasing CTGF-mediated signalling.
Conclusions
We suggest that the secreted CTGF mediates tumor cell progression via modulation of cell proliferation, adhesion, migration and metabolism and could possess a potential for being a therapeutic target.
Legal entity responsible for the study
Hanyang University.
Funding
National Research Foundation of Korea.
Disclosure
All authors have declared no conflicts of interest.
Session DOI (ID 228)
Single circulating tumour cell genomics as a biomarker for early drug development (ID 8)
- N. Stoecklein
- N. Stoecklein
Discussion (ID 40)
NTRK gene fusions: mechanisms and testing (ID 113)
- C. Marchiò
- C. Marchiò
17P - microRNA-16-5p enhances radiosensitivity through modulating cyclin D1/E1–pRb–E2F1 pathway in prostate cancer cells (ID 169)
- L. Gan
- F. Wang
Abstract
Background
Prostate cancer (CaP) was the second most common cancer in men worldwide in 2012, and radiation therapy is one of the most common definitive treatment options for localized CaP. However, radioresistance is a major challenge for current radiotherapy, accumulating evidence suggests microRNAs (miRNAs), as an important regulator in cellular ionizing radiation (IR) responses, are closely correlated with radiosensitivity in many cancers.
Methods
We performed human miRNA probe hybridization chip analysis to identify the expression profile of miRNAs in CaP cells exposed to IR, and then we analysed the cell proliferation, cell viability, and cell cycle after transfection of miR‐16‐5p into the CaP cells. Analysis of the cyclin D1/E1–pRb–E2F1 pathway related proteins were performed by western blotting.
Results
microRNA- 16-5p (miR-16-5p) is significantly upregulated in CaP LNCaP cells following IR and can enhance radiosensitivity through modulating the cyclin D1/E1–pRb–E2F1 pathway. Overexpression of miR-16-5p suppressed cell proliferation, reduced cell viability, and induced cell cycle arrest at G0/G1 phase, resulting in enhanced radiosensitivity in LNCaP cells. Additionally, miR-16-5p specifically targeted the cyclin D1/E1-3′-UTR in LNCaP cells and affected the expression of cyclin D1/E1 at both mRNA and protein levels.
Conclusions
miR-16-5p enhanced radiosensitivity of CaP cells, the mechanism may be through modulating the cyclin D1/cyclin E1/pRb/E2F1 pathway to cause cell cycle arrest at G0/G1 phase. These findings provided new insight into the correlation between miR‐16‐5p, cell cycle arrest, and radiosensitivity in CaP, revealed a previously unrecognized function of miR‐16‐5p–cyclin D1/E1–pRb–E2F1 regulation in response to IR and may offer an alternative therapy to improve the efficiency of conventional radiotherapy.
Legal entity responsible for the study
Institute of Modern Physics, Chinese Academy of Sciences.
Funding
Has not received any funding.
Disclosure
All authors have declared no conflicts of interest.
Session DOI (ID 223)
Welcome address – TAT 2019 Scientific Committee (ID 2)
- A. Adjei
- A. Adjei
Biomarkers & endpoints (ID 35)
- A. Marabelle
- A. Marabelle
Drug development: Lessons from success (ID 100)
- G. Schwartz
- G. Schwartz
12P - Targeting HIF1α/AP1 in hypoxia by novel 7-amino-6-halogeno-3-phenylquinoxaline-2-carbonitrile 1,4-dioxides (ID 140)
- A. Scherbakov
- A. Scherbakov
- G. Buravchenko
- L. Dezhenkova
- A. Shchekotikhin
Abstract
Background
HIF-1α and AP1 play important roles in hypoxia and activate anti-apoptotic pathways in tumor cells. No dual HIF-1α/AP1 inhibitors currently exist, so targeting these transcriptional factors is promising way to modulate hypoxia signaling in cancer cells. Aim of the study was obtaining and biological evaluation of hypoxia-selective 7-amino-6-halogen-substituted derivatives starting from 6,7-dihalogeno-3-phenylquinoxaline-2-carbonitrile 1,4-dioxides.
Methods
A series of 7-amino-6-halogeno-3-phenylquinoxaline-2-carbonitrile 1,4-dioxides was synthesized. Cancer cell lines were purchased from ATCC. The cytotoxic activity of compounds was evaluated in normoxia (21%O2) and hypoxia (1%O2). The cytotoxicity was assessed by MTT test (72 h growth with compounds). HIF-1α and AP1 activity was assessed by reporter analysis.
Results
Synthesis of 7-amino-6-halogen- substituted derivatives starting from 6,7-dihalogeno-3-phenylquinoxaline-2-carbonitrile 1,4-dioxides was carried out. A series was characterized by good solubility in water. Antiproliferative activity was evaluated in vitro on a panel of cancer cell lines including multidrug resistance variants. Novel synthesized compounds demonstrated higher hypoxia selectivity and cytotoxicity compared with tirapazamine. Some of the 7-amino-6-halogeno derivatives were 10-20-fold more potent than the reference drug. Selected 7-amino-6-halogeno derivatives LCTA-2425 and LCTA-2711 inhibited breast cancer cells growth in hypoxia at concentrations lower than 0.6 µM. Compounds LCTA-2711 and LCTA-2425 showed inhibitory effects on HIF-1α- and AP1-dependent luciferase activity, when tirapazamine revealed no potency to block these factors in MCF-7 breast cancer cells under hypoxic conditions.
Conclusions
A series of 7-amino-6-halogeno-3-phenylquinoxaline-2-carbonitrile 1,4-dioxides were more potent than reference drug tirapazamine in all tested cell lines and demonstrated high selectivity in hypoxia. Selected 7-amino-6-halogeno derivatives showed dual inhibitory activity against HIF-1α and AP1 factors, regulating anti-apoptotic pathways in hypoxia. RFBR grants 18-53-34005 (chemistry), 18-015-00422 (biology).
Legal entity responsible for the study
Alexander M. Scherbakov.
Funding
Russian Foundation for Basic Research, Grants 18-53-34005 (Chemistry) and 18-015-00422 (Biology).
Disclosure
All authors have declared no conflicts of interest.