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Moore KM, Cerqueira V, MacLeod KG, Mullen P, Hayward RL, Green S, Harrison DJ, Cameron DA, Langdon SP. Collateral-resistance to estrogen and HER-activated growth is associated with modified AKT, ERα, and cell-cycle signaling in a breast cancer model. EXPLORATION OF TARGETED ANTI-TUMOR THERAPY 2022; 3:97-116. [PMID: 35441158 PMCID: PMC7612628 DOI: 10.37349/etat.2022.00074] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Aim: A model of progressively endocrine-resistant breast cancer was investigated to identify changes that can occur in signaling pathways after endocrine manipulation. Methods: The MCF7 breast cancer model is sensitive to estrogens and anti-estrogens while variant lines previously derived from wild-type MCF7 are either relatively 17β-estradiol (E2
)-insensitive (LCC1) or fully resistant to estrogen and anti-estrogens (LCC9). Results: In LCC1 and LCC9 cell lines, loss of estrogen sensitivity was accompanied by loss of growth response to transforming growth factor alpha (TGFα), heregulin-beta and pertuzumab. LCC1 and LCC9 cells had enhanced AKT phosphorylation relative to MCF7 which was reflected in downstream activation of phospho-mechanistic target of rapamycin (mTOR), phospho-S6, and phospho-estrogen receptor alpha Ser167 [ERα(Ser167)]. Both AKT2 and AKT3 were phosphorylated in the resistant cell lines, but small interfering RNA (siRNA) knockdown suggested that all three AKT isoforms contributed to growth response. ERα(Ser118) phosphorylation was increased by E2 and TGFα in MCF7, by E2 only in LCC1, but by neither in LCC9 cells. Multiple alterations in E2-mediated cell cycle control were identified in the endocrine-resistant cell lines including increased expression of MYC, cyclin A1, cyclin D1, cyclin-dependent kinase 1 (CDK1), CDK2, and hyperphosphorylated retinoblastoma protein (ppRb), whereas p21 and p27 were reduced. Estrogen modulated expression of these regulators in MCF7 and LCC1 cells but not in LCC9 cells. Seliciclib inhibited CDK2 activation in MCF7 cells but not in resistant variants; in all lines, it reduced ppRb, increased p53 associated responses including p21, p53 up-regulated modulator of apoptosis (PUMA), and p53 apoptosis-inducing protein 1 (p53AIP1), inhibited growth, and produced G2/M block and apoptosis. Conclusions: Multiple changes occur with progression of endocrine resistance in this model with AKT activation contributing to E2 insensitivity and loss of ERα(Ser118) phosphorylation being associated with full resistance. Cell cycle regulation is modified in endocrine-resistant breast cancer cells, and seliciclib is effective in both endocrine-sensitive and resistant diseases.
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Affiliation(s)
- Kate M. Moore
- 1Cancer Research UK Edinburgh Centre, Institute of Genetics and Cancer, University of Edinburgh, Crewe Road South, EH4 2XR Edinburgh, UK 2Cancer Research UK Barts Centre, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, Charterhouse Square, EC1M 6BQ London, UK
| | - Vera Cerqueira
- 1Cancer Research UK Edinburgh Centre, Institute of Genetics and Cancer, University of Edinburgh, Crewe Road South, EH4 2XR Edinburgh, UK 3West of Scotland Clinical Genetics Service, Queen Elizabeth University Hospital, G51 4TF Glasgow, UK
| | - Kenneth G. MacLeod
- 1Cancer Research UK Edinburgh Centre, Institute of Genetics and Cancer, University of Edinburgh, Crewe Road South, EH4 2XR Edinburgh, UK
| | - Peter Mullen
- 4School of Medicine, University of St Andrews, North Haugh, KY16 9TF St Andrews, UK
| | - Richard L. Hayward
- 1Cancer Research UK Edinburgh Centre, Institute of Genetics and Cancer, University of Edinburgh, Crewe Road South, EH4 2XR Edinburgh, UK
| | - Simon Green
- 5Cyclacel Ltd, James Lindsay Place, Dundee Technopole, DD1 5JJ Dundee, UK
| | - David J. Harrison
- 4School of Medicine, University of St Andrews, North Haugh, KY16 9TF St Andrews, UK
| | - David A. Cameron
- 1Cancer Research UK Edinburgh Centre, Institute of Genetics and Cancer, University of Edinburgh, Crewe Road South, EH4 2XR Edinburgh, UK
| | - Simon P. Langdon
- 1Cancer Research UK Edinburgh Centre, Institute of Genetics and Cancer, University of Edinburgh, Crewe Road South, EH4 2XR Edinburgh, UK
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Palecková P, Kontrová F, Kofronová O, Bobek J, Benada O, Mikulík K. Effect of protein kinase inhibitors on protein phosphorylation and germination of aerial spores from Streptomyces coelicolor. Folia Microbiol (Praha) 2007; 52:215-22. [PMID: 17702458 DOI: 10.1007/bf02931301] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
In vitro phosphorylation reaction using extracts prepared from cells in the exponential phase of growth and aerial spores of Streptomyces coelicolor displayed the presence of multiply phosphorylated proteins. Effect of protein kinase inhibitors (PKIs) (geldanamycin, wortmannin, apigenin, genistein, roscovitine, methyl 2,5-dihydroxycinnamate, rapamycin, staurosporine) was determined on protein phosphorylation and on germination of spores. The in vitro experiments showed differences in phosphoprotein pattern due to the presence of PKIs. Cultivation of aerial spores with PKIs led to a significant delay in germ tube emergence and filament formation. However, none of the tested PKIs completely blocked the germination process. These results indicate that protein kinases of spores form complex networks sharing common modulating site that plays an important role in proper timing of early developmental events.
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Affiliation(s)
- P Palecková
- Institute of Microbiology, Academy of Sciences of the Czech Republic, 142 20 Prague, Czechia
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