G-Protein-coupled Estrogen Receptor 1 Agonist G-1 Perturbs Sunitinib Resistance-related Phosphoproteomic Signatures in Renal Cell Carcinoma

Abstract

Background: Metastatic renal cell carcinoma (RCC) often develops resistance to first-line targeted therapy such as sunitinib. G-Protein-coupled estrogen receptor 1 (GPER1) agonist G-1 was recently reported to regulate RCC physiology but the role of G-1 in RCC tumorigenesis and sunitinib resistance remains largely unknown. Materials and Methods: Parental and sunitinib-resistant 786-O cells were treated with GPER1 agonist G-1, and quantitative phosphoproteomics was performed. Bioinformatic analyses and validations, including immunoblotting, cell migration, and cell cycle distribution, were performed. Results: G-1 repressed cell proliferation and migration in both parental and sunitinib-resistant 786-O cells. Phosphoproteomic signatures, including phosphoinositide 3-kinase and protein kinase B (PI3K-AKT) as well as other pathways, were upregulated in sunitinib-resistant cells but application of G-1 reversed this effect. Among phosphoprotein candidates, activating transcription factor 2 (ATF2) Thr69/71 phosphorylation was antagonistically regulated by sunitinib resistance and G-1. Conclusion: Our results open up the possibility for managing RCC and sunitinib resistance by GPER1 agonist G-1 and its regulated pathways.Renal cell carcinoma (RCC) is the leading cause of kidney malignancy, contributing to an estimated 4-5% of new cases in 2020 (1). In addition to radical or partial nephrectomy, sunitinib is the first-line standard therapy for low-risk recurrent or metastatic RCC (2, 3). Primary or secondary resistance, however, usually develops after sunitinib administration (4). Although the combination of other target therapeutics, such as immune checkpoint inhibitors, seems to be a promising treatment option (5), there is still a need to investigate alternative strategies for managing RCC, especially in cases of sunitinib resistance.The incidence of RCC has a male-to-female ratio of 2:1 in young patients but becomes approximately 1:1 in patients over 70 years old (6), implying the inhibitory role of estrogen in RCC carcinogenesis. Estrogen can repress RCC growth by non-genomic signaling pathways via classical, nuclear estrogen receptors (7-9). In addition to nuclear estrogen receptors, G-protein-coupled estrogen receptor 1 (GPER1) was identified as a non-classical estrogen receptor, and its expression correlated with tumorigenesis and poor prognosis in several cancer types, including breast and prostate cancer (10). Treatment of in vitro cancer cell lines by the GPER1 agonist, G-1, led to variable results. For example, G-1 inhibited cell growth in prostate cancer (11) but promoted cell survival and migration in RCC cell lines (12). Recently, we demonstrated that estrogen inhibited RCC cell growth and alleviated sunitinib resistance in vitro through estrogen-triggered modulation of phosphorylation (9, 13). However, it remains unclear whether G-1 regulates phosphorylation dynamics in RCC tumorigenesis as well as and sunitinib resistance.Quantitative phosphoproteomics has been used to study phosphorylation signaling in ca...

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“…Oestrogen has been shown to have a negative effect on osteoclastogenesis 16‐20 and is widely accepted as an autophagic activator 25‐32 . An intriguing viewpoint is that autophagy facilitates osteoclastogenesis.…”

“…Oestrogen has been shown to have a negative effect on osteoclastogenesis [16][17][18][19][20] and is widely accepted as an autophagic activator. [25][26][27][28][29][30][31][32] An intriguing viewpoint is that autophagy facilitates osteoclastogenesis. Thus, there might exist a counteracting mechanism between Streicher and Liang et al 54,55 showed that oestrogen suppressed osteoclastogenesis by reducing the expression of RANKL.…”

“…Autophagy, as a protective mechanism at the cellular level, can enhance osteoclast formation and bone resorption activity. [21][22][23][24] Interestingly, numerous studies have suggested that oestrogen functions as an autophagic activator, [25][26][27][28][29][30][31][32] which might counteract the anti-osteoclastogenic effect of this agent. Although the regulatory role of autophagy in bone loss caused by oestrogen withdrawal has been reported in many studies, 23,24,[33][34][35][36][37] the role of oestrogen-mediated autophagy in osteoclastogenesis is still unknown.…”

Knockdown of G Protein-coupled Estrogen Receptor 1 (GPER1) Enhances Tumor-supportive Properties in Cervical Carcinoma Cells

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Lead Decreases Bone Morphogenetic Protein-7 (BMP-7) Expression and Increases Renal Cell Carcinoma Growth in a Sex-Divergent Manner

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