Publications by authors named "Nikiana Simigdala"

Deep sequencing of human tumours has uncovered a previously unappreciated role for epigenetic regulators in tumorigenesis. H3K4 methyltransferase KMT2C/MLL3 is mutated in several solid malignancies, including more than 10% of breast tumours. To study the tumour suppressor role of KMT2C in breast cancer, we generated mouse models of Erbb2/Neu, Myc or PIK3CA-driven tumorigenesis, in which the Kmt2c locus is knocked out specifically in the luminal lineage of mouse mammary glands using the Cre recombinase.

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Article Synopsis
  • Fulvestrant, a selective estrogen receptor degrader (SERD), is limited in breast cancer treatment due to low oral bioavailability, while the investigational SERD elacestrant is more effective and can be taken orally.
  • Both drugs are shown to negatively affect tumor growth in ER+ patient-derived models, but elacestrant remains effective even after resistance develops against fulvestrant.
  • When used in conjunction with CDK4/6 inhibitors, elacestrant enhances anti-cancer effects and demonstrates potential against drug-resistant cells, signifying the need for further clinical testing.
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Laser-based techniques for printing cells onto different substrates with high precision and resolution present unique opportunities for contributing to a wide range of biomedical applications, including tissue engineering. In this study, laser-induced forward transfer (LIFT) printing was employed to rapidly and accurately deposit patterns of cancer cells in a non-contact manner, using two different wavelengths, 532 and 355 nm. To evaluate the effect of LIFT on the printed cells, their growth and DNA damage profiles were assessed and evaluated quantitatively over several days.

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Elucidating signaling driven by lemur tyrosine kinase 3 (LMTK3) could help drug development. Here, we solve the crystal structure of LMTK3 kinase domain to 2.1Å resolution, determine its consensus motif and phosphoproteome, unveiling in vitro and in vivo LMTK3 substrates.

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A significant proportion of patients with oestrogen receptor (ER) positive breast cancers (BC) develop resistance to endocrine treatments (ET) and relapse with metastatic disease. Here we perform whole exome sequencing and gene expression analysis of matched primary breast tumours and bone metastasis-derived patient-derived xenografts (PDX). Transcriptomic analyses reveal enrichment of the G2/M checkpoint and up-regulation of Polo-like kinase 1 (PLK1) in PDX.

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Combination of CDK4/6 inhibitors and endocrine therapy improves clinical outcome in advanced oestrogen receptor (ER)-positive breast cancer, however relapse is inevitable. Here, we show in model systems that other than loss of RB1 few gene-copy number (CN) alterations are associated with irreversible-resistance to endocrine therapy and subsequent secondary resistance to palbociclib. Resistance to palbociclib occurred as a result of tumour cell re-wiring leading to increased expression of EGFR, MAPK, CDK4, CDK2, CDK7, CCNE1 and CCNE2.

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After publication of the original article [1], we were notified that an author's surname has been erroneously spelled. Elisabetta Maragoni's family name should be replaced with Marangoni.

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Background: Endocrine therapies are still the main strategy for the treatment of oestrogen receptor-positive (ER+) breast cancers (BC), but resistance remains problematic. Cross-talk between ER and PI3K/AKT/mTORC has been associated with ligand-independent transcription of ER. We have previously reported the anti-proliferative effects of the combination of everolimus (an mTORC1 inhibitor) with endocrine therapy in resistance models, but potential routes of escape via AKT signalling can lead to resistance; therefore, the use of dual mTORC1/2 inhibitors has met with significant interest.

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Background: Resistance to endocrine therapy remains a major clinical problem in the treatment of oestrogen-receptor positive (ER+) breast cancer. Studies show androgen-receptor (AR) remains present in 80-90% of metastatic breast cancers providing support for blockade of AR-signalling. However, clinical studies with abiraterone, which blocks cytochrome P450 17A1 (CYP17A1) showed limited benefit.

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Background: Endocrine therapies are the mainstay of treatment for oestrogen receptor (ER)-positive (ER) breast cancer (BC). However, resistance remains problematic largely due to enhanced cross-talk between ER and growth factor pathways, circumventing the need for steroid hormones. Previously, we reported the anti-proliferative effect of everolimus (RAD001-mTORC1 inhibitor) with endocrine therapy in resistance models; however, potential routes of escape from treatment via ERBB2/3 signalling were observed.

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Article Synopsis
  • Genome-wide association studies (GWAS) have pinpointed around 100 locations in the genome linked to breast cancer risk, but understanding the specific genes or non-coding RNAs involved is key to grasping the disease mechanisms.
  • Using a technique called Capture Hi-C (CHi-C), researchers annotated 63 of these risk loci and identified 110 potential target genes at 33 loci.
  • They found that 22 of the target genes are linked to gene expression, 32 are connected to disease-specific survival rates, and 14 are mutated in breast cancer or other cancers, paving the way for better insights into breast cancer risk and prognosis.
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Resistance to endocrine therapy remains a major clinical problem in breast cancer. Genetic studies highlight the potential role of estrogen receptor-α (ESR1) mutations, which show increased prevalence in the metastatic, endocrine-resistant setting. No naturally occurring ESR1 mutations have been reported in in vitro models of BC either before or after the acquisition of endocrine resistance making functional consequences difficult to study.

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Despite the effectiveness of endocrine therapies in estrogen receptor positive (ER+) breast cancer, approximately 40% of patients relapse. Previously, we identified the Focal-adhesion kinase canonical pathway as a major contributor of resistance to estrogen deprivation and cellular-sarcoma kinase (c-src) as a dominant gene in this pathway. Dasatinib, a pan-src inhibitor, has recently been used in clinical trials to treat ER+ patients but has shown mixed success.

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Background: Therapies targeting estrogenic stimulation in estrogen receptor-positive (ER+) breast cancer (BC) reduce mortality, but resistance remains a major clinical problem. Molecular studies have shown few high-frequency mutations to be associated with endocrine resistance. In contrast, expression profiling of primary ER+ BC samples has identified several promising signatures/networks for targeting.

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Article Synopsis
  • PI3K/AKT/mTOR signaling is crucial in breast cancer, particularly in the context of estrogen receptor (ER) signaling and acquired endocrine resistance, making treatment challenging.
  • Targeting mTOR along with endocrine therapy has clinical benefits, but a negative feedback mechanism complicates outcomes, suggesting that directly inhibiting AKT may enhance treatment efficacy.
  • AZD5363, a new AKT inhibitor, demonstrates promising results in resensitizing tamoxifen-resistant breast cancer cells and shows potential in combination with fulvestrant, indicating its value for future clinical trials.
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Imaginal discs, especially the wing imaginal disc, are powerful model systems to study organ development. The traditional methods to analyze wing imaginal discs depend on the laborious and time-consuming dissection of larvae. "Omics"-based approaches, such as RNA-seq, ChIP-seq, proteomics and lipidomics, offer new opportunities for the systems-level investigation of organ development.

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The co-operation of specialized organ systems in complex multicellular organisms depends on effective chemical communication. Thus, body fluids (like blood, lymph or intraspinal fluid) contain myriads of signaling mediators apart from metabolites. Moreover, these fluids are also of crucial importance for immune and wound responses.

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