https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0169925
Annexin/S100A Protein Family Regulation through p14ARF-p53 Activation: A Role in Cell Survival and Predicting Treatment Outcomes in Breast Cancer
Discussion
Approximately two-thirds of all breast cancers harbor the wild type p53 protein. Contrary to a long-held belief that favorable chemotherapy outcome is dependent upon p53-mediated apoptosis [50], some reports suggest a less favorable outcome for p53wt breast cancers [4, 15]. Our previous studies have demonstrated that p53 induces a viable, metabolically active senescence-like cellular phenotype which supports the paradigm that p53 may be protective against apoptosis in breast cancer cells [16, 17]. This has been partly explained by the concept that p53 interacts with ER to protect cells against apoptosis, yet how p53 activity hinders chemotherapy response is not clear. In order to accurately predict clinical response, we need to understand the cellular changes occurring in response to activation of the p53 pathway. Regulating calcium signaling is essential for mammary gland function and deregulation of calcium homeostasis is associated with cancer pathophysiology. It has been difficult to determine how these calcium-dependent multi-faceted annexin proteins are regulated due to the sequence similarity of the annexin family of proteins and their compensatory functions within the cell. However, using SILAC LC-MS/MS methodology, we could identify unique peptides within the N-terminal region of the individual annexin proteins and show how p53 regulates the expression of members of this protein family. Our bioinformatic analysis of p53-induced upregulation of protein expression showed a strong association between ANXAs/S100A and either TP53 (p53) or CDKN1A (p21). This aligns with previous findings showing that p53 transcriptional regulation of p21 is a link to its pro-survival function and is opposed to the A5 induced cell death, reviewed in Clarke et al, 2015 [51]. These findings support a renewed study of p53 as a central regulator of normal cellular function and pathophysiology. This report is the first to demonstrate p14ARF-p53 as a key central orchestrator of the annexin/S100A family of calcium regulators in favor of pro-survival functions in the breast cancer cell, in contrast to the activation of the canonical annexin A5 pro-apoptotic response usually associated with this tumor suppressor function. In the two cell lines studied, the annexin A5 pro-apoptotic pathway was not activated by p14ARF-p53.
The
annexins A1, A2, A4, A6 and A9, and annexin binding proteins S100A10,
S100A11 and S100A13 were in the top 50 proteins upregulated by
p14ARF/p53, as evidenced by SILAC-based analysis. Although the
function(s) of each annexin is not clearly defined, annexin-Ca2+
regulation is unquestionably important in a wide range of both intra-
and extracellular functions that require interaction with the acidic
phospholipids of the intracellular compartment of all membranes and Ca2+ signaling [19]. (Loogista eikö olekin!?)
Annexins in normal physiology and breast cancer
The annexin A2/S100A10 complex, the abundance of which is increased by p53 activation, plays a role in membrane organization, membrane trafficking, in promoting ion conductance across membranes [19], and in calcium redistribution from bone to breast [52–54]. Annexin A4 has recently been shown to be involved in plasma membrane remodeling, through regulation of the actin cytoskeleton, and in cellular cholesterol homeostasis [55]. The role of annexin A6 as a membrane organizer is further supported by a recent study [56]. These observations are consistent with the changes we have observed in the architectural reorganization of the cytoskeleton of MCF-7 cells post p14ARF/p53/p21 activation [17], suggesting annexin regulation via this pathway may be a normal cellular process in breast physiology.
Aberrant calcium signaling is often linked to each of the hallmarks of cancer cells [57]. In this report we highlight how differential changes in annexin and S100A expression may impact on signaling pathways and potentially lead to the activation or inhibition of downstream and/or compensatory cellular mechanisms, dependent upon the direction of expression change. Annexin and S100A deregulation has been associated with tumor invasion and metastasis, angiogenesis and drug resistance [20, 30, 31]. Loss of annexin A1 has been associated with malignant transformation in ER+ breast cancer [22], and, conversely, recent reports associate high annexin A1 expression with cellular invasion in ER- [27]. Increases in annexin A2 and S100A11 are associated with cell viability and increased invasiveness through their ability to maintain plasma membrane integrity [58] and promote epithelial-mesenchymal transition [29]. Dysregulation of individual annexin expression is associated with cancer development and treatment outcomes and it has been suggested that considering the expression of individual annexins may provide useful diagnostic and prognostic biomarkers [20]. Furthermore, modulation of calcium signaling has been demonstrated to change sensitivity of chemotherapeutic agents to apoptotic signals. This led to our further investigation of the impact of the differential regulation of annexin expression by p53 on patient treatment outcomes.
The ER-p53-annexin expression profile and treatment outcomes
To address how increases in the expression of individual annexins (A1, A2, A4, A6 and A9) and S100A binding partners (S100A10, S100A11 and S100A13), and combinations of thereof, could influence treatment outcomes, we performed a meta-analysis (biomarker assessment) based on 4142 breast cancer samples using the Kaplan-Meier plot database for breast cancer (available online) [38]. This is the first biomarker analysis directly comparing patient treatment outcomes using expression data of each individual annexin and then combining the expression date of all annexins and S100A binding proteins (i.e. an annexin expression profile) in a specific sub-set of breast cancer patients (ER+p53+) within a larger cohort. Overall, ER+ patient prognosis was more favorable when p53wt was present and was associated with increased RFS, DMSF and OS. The exception to this was upregulation of annexin A9 and S100A13, which were associated with poor RFS and RFS/OS respectively, and, interestingly, this was only in patients who had undergone endocrine treatments. The most favorable prognosis and survival odds were observed when all the upregulated annexins and S100A proteins were taken into account together as an expression profile or signature, and a comparison was made between ER+p53- patient tumors and ER+p53wt+ tumors. In general, all tumors responded more positively when p53wt was expressed independent of treatment regime. The most striking observation was that of ER+p53+ tumors with the expression profile of upregulated annexin A1, A2, A4, A6, A9 and S100A, A11 and A13, which showed great benefit from tamoxifen intervention alone, and, it was further shown, that additional treatment with chemotherapy would have no added beneficial effect. In conclusion, this study ascribes to p53wt the functions of a key organizer of calcium metabolism in breast cancer cells through the differential regulation of expression of the annexins, which are important calcium regulators. We have shown that p53 mediates pro-survival signalling in breast cancer cells and does not induce the canonical annexin A5 apoptotic pathway as previously thought. Although we, and others, have shown that reactivation of the canonical p14ARF-p53 pathway does not induce apoptosis in our studies, this does not necessarily relate to resistance to either chemotherapy or endocrine therapies. In our retrospective studies using a freely available breast cancer database, induction of p53 and overexpression of annexins associated with pro-survival functions is not associated with resistance to endocrine therapy. However, p53 induced overexpression of annexins, with consequent cellular phenotypic alterations appears to influence treatment outcomes in breast cancer. Importantly, prognosis/treatment outcome prediction is modified by whether one considers single genes individually or combines the gene expression profiles of various genes. Combining expression data of many genes is therefore the way forward to getting best /most accurate prognostic/treatment outcome information.
Löytyipä anti VEGF vaikutuksen puolelta artikkelia annexiineista!
https://www.biostock.se/2023/09/annexins-vd-var-overlagset-storsta-framgang-pa-lange/
Annexin-1, mitotic spindle.
https://www.biorxiv.org/content/10.1101/2021.07.28.454117v1
Annexin-2 depletion
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