Effect of oncogene activating mutations and kinase inhibitors on amino acid metabolism of human isogenic breast cancer cells

2015 ◽  
Vol 11 (12) ◽  
pp. 3378-3386 ◽  
Author(s):  
Eung-Sam Kim ◽  
Animesh Samanta ◽  
Hui Shan Cheng ◽  
Zhaobing Ding ◽  
Weiping Han ◽  
...  

K-Ras/PI3K knock-in mutation and treatment of kinase inhibitors altered the intracellular amino acid metabolism compared to the wild-type breast cell.

2011 ◽  
Vol 255 (1) ◽  
pp. 94-102 ◽  
Author(s):  
Chang Seon Ryu ◽  
Hui Chan Kwak ◽  
Kye Sook Lee ◽  
Keon Wook Kang ◽  
Soo Jin Oh ◽  
...  

Cells ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 1468
Author(s):  
Sumeyye Cavdarli ◽  
Larissa Schröter ◽  
Malena Albers ◽  
Anna-Maria Baumann ◽  
Dorothée Vicogne ◽  
...  

The O-acetylated form of GD2, almost exclusively expressed in cancerous tissues, is considered to be a promising therapeutic target for neuroectoderm-derived tumors, especially for breast cancer. Our recent data have shown that 9-O-acetylated GD2 (9-OAcGD2) is the major O-acetylated ganglioside species in breast cancer cells. In 2015, Baumann et al. proposed that Cas 1 domain containing 1 (CASD1), which is the only known human sialyl-O-acetyltransferase, plays a role in GD3 O-acetylation. However, the mechanisms of ganglioside O-acetylation remain poorly understood. The aim of this study was to determine the involvement of CASD1 in GD2 O-acetylation in breast cancer. The role of CASD1 in OAcGD2 synthesis was first demonstrated using wild type CHO and CHOΔCasd1 cells as cellular models. Overexpression using plasmid transfection and siRNA strategies was used to modulate CASD1 expression in SUM159PT breast cancer cell line. Our results showed that OAcGD2 expression was reduced in SUM159PT that was transiently depleted for CASD1 expression. Additionally, OAcGD2 expression was increased in SUM159PT cells transiently overexpressing CASD1. The modulation of CASD1 expression using transient transfection strategies provided interesting insights into the role of CASD1 in OAcGD2 and OAcGD3 biosynthesis, and it highlights the importance of further studies on O-acetylation mechanisms.


2021 ◽  
Vol 22 (15) ◽  
pp. 8165
Author(s):  
Amanda Chantziou ◽  
Kostas Theodorakis ◽  
Hara Polioudaki ◽  
Eelco de Bree ◽  
Marilena Kampa ◽  
...  

In breast cancer, expression of Cluster of Differentiation 24 (CD24), a small GPI-anchored glycoprotein at the cell periphery, is associated with metastasis and immune escape, while its absence is associated with tumor-initiating capacity. Since the mechanism of CD24 sorting is unknown, we investigated the role of glycosylation in the subcellular localization of CD24. Expression and localization of wild type N36- and/or N52-mutated CD24 were analyzed using immunofluorescence in luminal (MCF-7) and basal B (MDA-MB-231 and Hs578T) breast cancer cells lines, as well as HEK293T cells. Endogenous and exogenously expressed wild type and mutated CD24 were found localized at the plasma membrane and the cytoplasm, but not the nucleoplasm. The cell lines showed different kinetics for the sorting of CD24 through the secretory/endocytic pathway. N-glycosylation, especially at N52, and its processing in the Golgi were critical for the sorting and expression of CD24 at the plasma membrane of HEK293T and basal B type cells, but not of MCF-7 cells. In conclusion, our study highlights the contribution of N-glycosylation for the subcellular localization of CD24. Aberrant N-glycosylation at N52 of CD24 could account for the lack of CD24 expression at the cell surface of basal B breast cancer cells.


2019 ◽  
Author(s):  
Eliza E. Bitter ◽  
Michelle H. Townsend ◽  
Kary Y.F. Tsai ◽  
Carolyn I. Allen ◽  
Rachel I. Erickson ◽  
...  

Abstract 1. Background: The salvage pathway enzyme thymidine kinase 1 (TK1) is elevated in the serum of several different cancer types and higher expression is associated with more aggressive tumor grade. As a result, it has potential as a biomarker for diagnosis and prognosis. Recent studies indicate that TK1 may be involved in cancer pathogenesis; however, its direct involvement has not been identified. We propose to evaluate the effects of TK1 on cancer progression in vitro through measuring cellular invasion and survival of breast cancer cells.2.Methods: Breast cancer cells MDA-MB-231, HCC 1806, and MCF7 were cultured according to standard techniques. We employed the use of TK1 target siRNA and a CRISPR-Cas9 TK1 knockout plasmid to compare transfected cell lines to wild type cell lines. Protein factors in survival and invasive pathways were also tested for correlations to TK1 in BRCA RNA-seq patient data (n=1095) using the TIMER program. Cellular invasion was quantified in cell index (factor of impedance) over a 24-hour period. Cell survival was measured by apoptosis under metabolic and DNA stress using flow cytometry. All results were statistically assessed using an ANOVA or t-test in GraphPad PRISM®.3.Results: Cellular invasion assays assessing wild type and TK1 knockdown/knockout (TK1-/-) cell types showed TK1-/- cell lines had increased invasion potential (p= 0.0001). Bioinformatically, we saw a strong overall negative correlation between apoptotic factors and TK1 (p ≤ 0.05). When testing TK1 effects on cell survival we saw a protective affect under DNA stress (p ≤ 0.05), but not under metabolic stress (p= 0.0001).4.Conclusion From cell cycle analysis, we observed a shift towards S phase in TK1-/- cells. This shift to S phase would promote growth and account for the increased cellular invasion and decrease in metabolic induced stress in TK1-/- cells. We propose that cancer cells still may elicit a cancer progressive phenotype based on effects of TK1, but that a system which isolates TK1 is not effective to understand the effects. Instead, identifying protein networks inclusive of TK1 will help to elucidate its effects on cancer progression.


Cancers ◽  
2019 ◽  
Vol 11 (2) ◽  
pp. 197 ◽  
Author(s):  
Martina S.J. McDermott ◽  
Neil Conlon ◽  
Brigid C. Browne ◽  
Adam Szabo ◽  
Naoise C. Synnott ◽  
...  

Prolonged treatment of HER2 positive breast cancer cells with tyrosine kinase inhibitors (TKIs) leads to the emergence of acquired resistance. However, the effects of continuous TKI exposure on cell fate, and the steps leading to the acquisition of a resistant phenotype are poorly understood. To explore this, we exposed five HER2 positive cells lines to HER2 targeted therapies for periods of up to 4 weeks and examined senescence associated β-galactosidase (SA-β-gal) activity together with additional markers of senescence. We found that lapatinib treatment resulted in phenotypic alterations consistent with a senescent phenotype and strong SA-β-gal activity in HER2-positive cell lines. Lapatinib-induced senescence was associated with elevated levels of p15 and p27 but was not dependent on the expression of p16 or p21. Restoring wild type p53 activity either by transfection or by treatment with APR-246, a molecule which reactivates mutant p53, blocked lapatinib-induced senescence and caused increased cell death. In contrast to lapatinib, SA-β-gal activity was not induced by exposing the cells to trastuzumab as a single agent but co-administration of lapatinib and trastuzumab induced senescence, as did treatment of the cells with the irreversible HER2 TKIs neratinib and afatinib. Neratinib- and afatinib-induced senescence was not reversed by removing the drug whereas lapatinib-induced senescence was reversible. In summary, therapy-induced senescence represents a novel mechanism of action of HER2 targeting agents and may be a potential pathway for the emergence of resistance.


2007 ◽  
Vol 109 (3) ◽  
pp. 471-479 ◽  
Author(s):  
Teresa Puig ◽  
Alejandro Vázquez-Martín ◽  
Joana Relat ◽  
Jordi Pétriz ◽  
Javier A. Menéndez ◽  
...  

2010 ◽  
Author(s):  
Caroline Bruenner-Kubath ◽  
Waheed Shabbir ◽  
Victoria Saferding ◽  
Renate Wagner ◽  
Christian F. Singer ◽  
...  

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