scholarly journals CyclinG1 Amplification Enhances Aurora Kinase Inhibitor-Induced Polyploid Resistance and Inhibition of Bcl-2 Pathway Reverses the Resistance

2017 ◽  
Vol 43 (1) ◽  
pp. 94-107 ◽  
Author(s):  
Wenfeng Zhang ◽  
Jie Xu ◽  
Dexiang Ji ◽  
Zhangyun Li ◽  
Wenxing He ◽  
...  

Background/Aims: CyclinG1 (CycG1) is frequently overexpressed in solid tumors and overexpression of CycG1 promotes cell survival upon paclitaxel exposure by inducing polyploidy. Whether and how CycG1 regulates polyploidization caused by small molecular targeted inhibitors remains unclear. Methods: Immunohistochemistry and immunoblotting were utilized to examine protein expression. Cell proliferation was measured by ATPlite assay, and cell cycle distribution and apoptosis were measured by flow cytometry and/or DNA fragmentation assays. Results: Overexpression of CycG1 in breast cancer cells caused apoptosis-resistant polyploidy upon treatment with Aurora kinase inhibitor, ZM447439 (ZM). Addition of ABT-263, a small-molecule BH3 mimetic, to ZM, produced a synergistic loss of cell viability with greater sustained tumor growth inhibition in breast cancer cell lines. Decrease of Mcl-1 and increase of NOXA caused by ZM treatment, were responsible for the synergy. Furthermore, CycG1 was highly expressed in Triple-Negative-Breast-Cancer patients treated with paclitaxel and was paralleled by decreased cell survival. Conclusion: CycG1 is a crucial factor in ZM-induced polyploidy resistance, and ABT-263/ZM combination hold therapeutic utility in the CycG1-amplified subset of breast cancer and CycG1, thus, is a promising target in breast cancer.

Author(s):  
Tuğçe Balcı Okcanoğlu ◽  
Çağla Kayabaşı ◽  
Cumhur Gündüz

Long non-coding RNAs (lncRNAs) are involved in a range of biological processes, such as cellular differentiation, migration, apoptosis, invasion, proliferation, and transcriptional regulation. The aberrant expression of lncRNAs plays a significant role in several cancer types. Aurora kinases are increasingly expressed in various malignancies; accordingly, the inhibition of these enzymes may represent a novel approach for the treatment of various cancers. CCT137690, an Aurora kinase inhibitor, displays an anti-proliferative activity in human cancer cell lines. The aim of the present study was to investigate the anti-proliferative and cytotoxic effects of CCT137690 on estrogen receptor (ER)-positive human breast cancer cell line (MCF-7) and ER-negative human breast cancer cell line (MDA-MB-231). In addition, this study was targeted toward determining the changes induced in lncRNA expression levels following the initiation of Aurora kinase inhibitor treatment. The cytotoxic effects of CCT137690 were determined by means of the xCELLigence system. Furthermore, the anti-proliferative role of CCT137690 in breast cancer was investigated by checking the changes in lncRNA expression profiles using quantitative reverse-transcription polymerase chain reaction (qRT-PCR). The half-maximal inhibitory concentrations (IC50) of CCT137690 were determined as 4.5 μM (MCF-7) and 7.27 μM (MDA-MB-231). Several oncogenic lncRNAs (e.g., PRINS, HOXA1AS, and NCRMS) were downregulated in both ER-negative and ER-positive cell lines. On the other hand, tumor suppressor lncRNAs (e.g., DGCR5 and IGF2AS) were upregulated in the ER-positive cell line. After CCT137690 treatment, HOXA11AS and PCAT-14 lncRNAs were downregulated in the ER-positive cell lines. In addition, MER11C, SCA8, BC200, HOTAIR, PCAT-1, UCA1, SOX2OT, and HULC lncRNAs were downregulated in the ER-negative cell lines. The results of the present study indicated that Aurora kinase inhibitor CCT137690 could be a potential anti-cancer agent for breast cancer treatment.


2009 ◽  
Vol 27 (15_suppl) ◽  
pp. e14605-e14605
Author(s):  
D. Tryfonopoulos ◽  
N. O'Donovan ◽  
B. Corkery ◽  
M. Clynes ◽  
J. Crown

e14605 Background: Triple-negative breast cancers (TNBC) lack expression of oestrogen, progesterone, and are HER-2 normal. TNBC cell lines have displayed greater sensitivity to growth inhibition by the multi-target kinase inhibitor, dasatinib, than luminal or HER- 2 positive breast cancer cell lines. The aim of this study was to assess the direct anti-tumor effects of dasatinib in combination with chemotherapy in TNBC. Methods: Four TNBC cell lines (MDA-MB-231, HCC-1143, HCC-1937, MDA-MB-468) were treated with dasatinib in combination with docetaxel, cisplatin or 5'-5' DFUR. IC50 values were calculated for each drug alone by determining response in a 5-day proliferation (acid phosphatase) assay. Combination index (CI) values were determined, using CalcuSyn, to assess the interaction between drugs. Results: Three of the cell lines (MDA-MB-231, HCC- 1143, HCC-1937) were sensitive to dasatinib (IC50 < 1 μM) whereas MDA-MB-468 was resistant (IC50 > 1 μM) (Table). In MDA-MB-231 and HCC-1143 cells, combined treatment with dasatinib and 5'-5'-DFUR displayed synergy (CI<1.0), whereas the combination was additive in HCC-1937 cells (CI=0.98). Combined treatment with dasatinib and cisplatin was synergistic in the three dasatinib sensitive cell lines (CI<1.0). Dasatinib in combination with docetaxel displayed moderate synergy in MDA-MB-231 and HCC-1937 cells (CI<1.0), but was antagonistic in HCC-1143 cells (CI>1.0). Conclusions: Our findings show that the combination of dasatinib with either 5'-5'-DFUR or cisplatin is synergistic in TNBC cell lines, and suggest that combinations of dasatinib with chemotherapy may improve response in triple negative breast cancer patients. [Table: see text] No significant financial relationships to disclose.


2021 ◽  
Vol 22 (10) ◽  
pp. 5382
Author(s):  
Pei-Yi Chu ◽  
Hsing-Ju Wu ◽  
Shin-Mae Wang ◽  
Po-Ming Chen ◽  
Feng-Yao Tang ◽  
...  

(1) Background: methionine cycle is not only essential for cancer cell proliferation but is also critical for metabolic reprogramming, a cancer hallmark. Hepatic and extrahepatic tissues methionine adenosyltransferases (MATs) are products of two genes, MAT1A and MAT2A that catalyze the formation of S-adenosylmethionine (SAM), the principal biological methyl donor. Glycine N-methyltransferase (GNMT) further utilizes SAM for sarcosine formation, thus it regulates the ratio of SAM:S-adenosylhomocysteine (SAH). (2) Methods: by analyzing the TCGA/GTEx datasets available within GEPIA2, we discovered that breast cancer patients with higher MAT2A had worse survival rate (p = 0.0057). Protein expression pattern of MAT1AA, MAT2A and GNMT were investigated in the tissue microarray in our own cohort (n = 252) by immunohistochemistry. MAT2A C/N expression ratio and cell invasion activity were further investigated in a panel of breast cancer cell lines. (3) Results: GNMT and MAT1A were detected in the cytoplasm, whereas MAT2A showed both cytoplasmic and nuclear immunoreactivity. Neither GNMT nor MAT1A protein expression was associated with patient survival rate in our cohort. Kaplan–Meier survival curves showed that a higher cytoplasmic/nuclear (C/N) MAT2A protein expression ratio correlated with poor overall survival (5 year survival rate: 93.7% vs. 83.3%, C/N ratio ≥ 1.0 vs. C/N ratio < 1.0, log-rank p = 0.004). Accordingly, a MAT2A C/N expression ratio ≥ 1.0 was determined as an independent risk factor by Cox regression analysis (hazard ratio = 2.771, p = 0.018, n = 252). In vitro studies found that breast cancer cell lines with a higher MAT2A C/N ratio were more invasive. (4) Conclusions: the subcellular localization of MAT2A may affect its functions, and elevated MAT2A C/N ratio in breast cancer cells is associated with increased invasiveness. MAT2A C/N expression ratio determined by IHC staining could serve as a novel independent prognostic marker for breast cancer.


Sign in / Sign up

Export Citation Format

Share Document