Neuronal Calcium Sensor 1 is up‐regulated in response to stress to promote cell survival and motility in cancer cells

Abstract

Changes in intracellular calcium (Ca 2+ ) signaling can modulate cellular machinery required for cancer progression. Neuronal calcium sensor 1 (NCS1) is a ubiquitously expressed Ca 2+ -binding protein that promotes tumor aggressiveness by enhancing cell survival and metastasis. However, the underlying mechanism by which NCS1 contributes to increased tumor aggressiveness has yet to be identified. In this study, we aimed to determine (a) whether NCS1 expression changes in response to external stimuli, (b) the importance of NCS1 for cell survival and migration, and (c) the cellular mechanism(s) through which NSC1 modulates these outcomes. We found that NCS1 abundance increases under conditions of stress, most prominently after stimulation with the pro-inflammatory cytokine tumor necrosis factor a, in a manner dependent on nuclear factor kappa-light-chain-enhancer of activated B cells (NFjB). We found that NFjB signaling is activated in human breast cancer tissue, which was accompanied by an increase in NCS1 mRNA expression. Further exploration into the relevance of NCS1 in breast cancer progression showed that knockout of NCS1 (NCS1 KO) caused decreased cell survival and motility, increased baseline intracellular Ca 2+ levels, and decreased inositol 1,4,5-trisphosphate-mediated Ca 2+ responses. Protein kinase B (Akt) activity was decreased in NCS1 KO cells, which could be rescued by buffering intracellular Ca 2+ . Conversely, Akt activity was increased in cells overexpressing NCS1 (NCS1 OE). We therefore conclude that NCS1 acts as cellular stress response protein up-regulated by stress-induced NFjB signaling and that NCS1 influences cell survival and motility through effects on Ca 2+ signaling and Akt pathway activation. AbbreviationsAkt, protein kinase B; Ca 2+ , calcium; ER, endoplasmic reticulum; InsP3, inositol 1,4,5-trisphosphate; InsP3R, inositol 1,4,5-trisphosphate receptor; IjBa, nuclear factor of kappa-light polypeptide gene enhancer in B-cell inhibition, alpha; NCS1, neuronal calcium sensor 1; NFjB, nuclear factor kappa-light-chain-enhancer of activated B cells; p-Akt, phosphorylated Akt; PI3K, phosphoinositide-3-kinase; PP2Ac, catalytic subunit of protein phosphatase 2A; tBHP, tert-butylhydroperoxide; TG, thapsigargin; TNF-a, tumor necrosis factor alpha.

Disulfide Dimerization of Neuronal Calcium Sensor-1: Implications for Zinc and Redox Signaling

“…Previous studies using cellular and animal models have shown that in neurons and cardiomyocytes, NCS-1 exhibits protective activity against various types of stress [35,36,75]. Similar activity on the part of this protein has been demonstrated in breast cancer cells [76]. These observations generally agree with our data obtained using the Y79 model, in that NCS-1 is involved in signaling pathways regulating cell death/survival decisions.…”

Neuronal calcium sensor 1 (NCS1) dependent modulation of neuronal morphology and development

“…Systems biology analysis indicated that NCS1 affects genes related to a broad range of signaling pathways, particularly related to cell morphology and neurodevelopment, which may explain the results we obtained from Golgi‐Cox experiments and stimulated further analysis of developmental databases. A subtle but broad regulatory effect of NCS1 on gene expression was expected—and filtering criteria for the differential gene expression analysis were set accordingly—because NCS1 is not a direct transcription factor but can affect gene expression indirectly through its role in regulating cytosolic and nuclear Ca 2+ signals 9–11,50 . For example, previous studies suggest that NCS1 is involved in the cytosolic activation of Ca 2+ /CaM‐dependent protein kinase CaMKII, which is a major regulator of transcription factors like cAMP response element‐binding protein CREB 21,51,52 .…”

“…A subtle but broad regulatory effect of NCS1 on gene expression was expected-and filtering criteria for the differential gene expression analysis were set accordingly-because NCS1 is not a direct transcription factor but can affect gene expression indirectly through its role in regulating cytosolic and nuclear Ca 2+ signals. [9][10][11]50 For example, previous studies suggest that NCS1 is involved in the cytosolic activation of Ca 2+ / CaM-dependent protein kinase CaMKII, which is a major regulator of transcription factors like cAMP response element-binding protein CREB. 21,51,52 Similarly, it has been reported that hippocalcin, another member of the neuronal Ca 2+ sensor family, regulates CREB.…”

“…55,56 A role for NCS1 in regulating neuronal morphology is supported by previous studies describing that NCS1 enhances neurite outgrowth [16][17][18] and synaptic transmission, specifically neurotransmitter release, LTP, and LTD. [12][13][14][15] Similarly, NCS1 regulates exocytosis in adrenal chromaffin cells, 57 morphology of cardiomyocytes, 52 and motility of cancer cells. 50,58 The gross morphology of the brain has been reported to be unaltered in Ncs1 −/− mice. 21 Reduced dendritic morphology in Ncs1 −/− mice may be due to several, not mutually exclusive mechanisms.…”

The function of apolipoproteins L (APOLs): relevance for kidney disease, neurotransmission disorders, cancer and viral infection

“…The phenotype of APOL1Δ and APOL3KO podocytes exhibits striking similarities to that resulting from cancer metastasis, with strong reduction of cellular adherence and increase in cell motility, together with important reduction of the capacity for apoptosis [8]. Accordingly, the APOL3‐controlled NCS‐1 is known to promote motility, metastatic spread and survival of cancer cells [106,107], and the NCS‐1 antagonist CALN‐1 also exhibits relationship with metastatic cell migration [108]. Since in human breast cancer, Golgi PI(4)P is known to regulate cellular adhesion and invasive cell migration [109], the observed reduction of PI(4)P in APOL1Δ and APOL3KO podocytes could be responsible for this metastasis‐like phenotype.…”