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Secreted gelsolin desensitizes CD3-activated CD4 + T cells and induces the apoptosis of CD8 + T cells in the presence of PCa cells. (A) Following the incubation of CD3 antibody-activated CD4 + and CD8 + T cells with conditioned media from
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Loss of immunosurveillance is a major cause of cancer progression. Here, we demonstrate that gelsolin, a constituent of ejaculate, induces apoptosis of activated lymphocytes in prostate cancer. Gelsolin was highly expressed in prostate cancer cells, and was associated with tumor progression, recurrence, metastasis, and poor prognosis. In vitro, sec...
Contexts in source publication
Context 1
... incubation of CD3 antibody-activated CD4 + and CD8 + T cells with conditioned media from LNCaP cells (containing 474.7 ± 30.6 μg/mL of secreted gelsolin), both types of T cells became positive for gelsolin ( Figure 4A). Interestingly, after being coated with gelsolin for 48 hours, both types of T cells shrank from 11.12 ± 0.08 μm to 6.85 ± 0.35 μm in size (p < 0.007, Figure 4B). ...
Context 2
... incubation of CD3 antibody-activated CD4 + and CD8 + T cells with conditioned media from LNCaP cells (containing 474.7 ± 30.6 μg/mL of secreted gelsolin), both types of T cells became positive for gelsolin ( Figure 4A). Interestingly, after being coated with gelsolin for 48 hours, both types of T cells shrank from 11.12 ± 0.08 μm to 6.85 ± 0.35 μm in size (p < 0.007, Figure 4B). When gelsolin-coated lymphocytes were co-incubated with PCa cells, the number of apoptotic CD8 + T cells increased about 50% ( Figure 4C and 4D). ...
Context 3
... after being coated with gelsolin for 48 hours, both types of T cells shrank from 11.12 ± 0.08 μm to 6.85 ± 0.35 μm in size (p < 0.007, Figure 4B). When gelsolin-coated lymphocytes were co-incubated with PCa cells, the number of apoptotic CD8 + T cells increased about 50% ( Figure 4C and 4D). The cytotoxic effect, however, was less evident in CD4 + T cells. ...
Context 4
... acid sequence analysis with online software (http://web.expasy.org/protscale/) indicated that sortilin contains several hydrophobic regions, which could bind to lipoproteins and cholesterol (Supplementary Figure 4) [20]. Likewise, secreted gelsolin also contains five lipid binding sites [21], suggesting that both proteins might be involved in the cellular uptake of lipids. ...
Context 5
... is worth noting that sortilin contains several hydrophobic stretches (Supplementary Figure 4), which may serve as docking sites where low density lipoprotein can unload essential lipids such as dehydroepiandrosterone, ω-3 and, ω-6 fatty acids and cholesterol onto the lipid rafts of target cells [29,30]. A membrane invagination could then be activated to initiate endocytosis upon the binding of secreted gelsolin to sortilin. ...
Citations
... Recently, pGSN has gained much attention because of its role in OVCA chemoresistance as well as in other malignancies [13,[17][18][19]. pGSN is highly expressed in chemoresistant OVCA cells, secreted via exosomes and activates the α5β1 integrins / FAK (focal adhesion kinase) / Akt / HIF-1α (hypoxia-inducible factor-1) axis resulting in increased pGSN production which confers resistance to otherwise sensitive OVCA cells in a paracrine manner. ...
Background
Ovarian cancer (OVCA) is the most lethal gynecologic cancer and chemoresistance remains a major hurdle to successful therapy and survival of OVCA patients. Plasma gelsolin (pGSN) is highly expressed in chemoresistant OVCA compared with their chemosensitive counterparts, although the mechanism underlying the differential expression is not known. Also, its overexpression significantly correlates with shortened survival of OVCA patients. In this study, we investigated the methylation role of Ten eleven translocation isoform-1 (TET1) in the regulation of differential pGSN expression and chemosensitivity in OVCA cells.
Methods
Chemosensitive and resistant OVCA cell lines of different histological subtypes were used in this study to measure pGSN and TET1 mRNA abundance (qPCR) as well as protein contents (Western blotting). To investigate the role of DNA methylation specifically in pGSN regulation and pGSN-induced chemoresistance, DNMTs and TETs were pharmacologically inhibited in sensitive and resistant OVCA cells using specific inhibitors. DNA methylation was quantified using EpiTYPER MassARRAY system. Gain-and-loss-of-function assays were used to investigate the relationship between TET1 and pGSN in OVCA chemoresponsiveness.
Results
We observed differential protein and mRNA expressions of pGSN and TET1 between sensitive and resistant OVCA cells and cisplatin reduced their expression in sensitive but not in resistant cells. We observed hypomethylation at pGSN promoter upstream region in resistant cells compared to sensitive cells. Pharmacological inhibition of DNMTs increased pGSN protein levels in sensitive OVCA cells and decreased their responsiveness to cisplatin, however we did not observe any difference in methylation level at pGSN promoter region. TETs inhibition resulted in hypermethylation at multiple CpG sites and decreased pGSN protein level in resistant OVCA cells which was also associated with enhanced response to cisplatin, findings that suggested the methylation role of TETs in the regulation of pGSN expression in OVCA cells. Further, we found that TET1 is inversely related to pGSN but positively related to chemoresponsiveness of OVCA cells.
Conclusion
Our findings broaden our knowledge about the epigenetic regulation of pGSN in OVCA chemoresistance and reveal a novel potential target to re-sensitize resistant OVCA cells. This may provide a future therapeutic strategy to improve the overall OVCA patient survival.
... Recently, pGSN has gained much attention because of its role in OVCA chemoresistance as well as in other malignancies [13], [17]- [19]. pGSN is highly expressed in chemoresistant OVCA cells, secreted via exosomes and activates the α5β1 integrins / FAK (focal adhesion kinase) / Akt / HIF-1α (hypoxiainducible factor-1) axis resulting in increased pGSN production which confers resistance to otherwise sensitive OVCA cells in a paracrine manner. ...
Background: Ovarian cancer (OVCA) is the most lethal gynecologic cancer and chemoresistance remains a major hurdle to successful therapy and survival of OVCA patients. Plasma gelsolin (pGSN) is highly expressed in chemoresistant OVCA compared with their chemosensitive counterparts, although the mechanism underlying the differential expression is not known. Also, its overexpression significantly correlates with shortened survival of OVCA patients. In this study, we investigated the methylation role of Ten eleven translocation isoform-1 (TET1) in the regulation of differential pGSN expression and chemosensitivity in OVCA cells.
Methods: Chemosensitive and resistant OVCA cell lines of different histological subtypes were used in this study to measure pGSN and TET1 mRNA abundance (qPCR) as well as protein contents (Western blotting). To investigate the role of DNA methylation specifically in pGSN regulation and pGSN-induced chemoresistance, DNMTs and TETs were pharmacologically inhibited in sensitive and resistant OVCA cells using specific inhibitors. DNA methylation was quantified using EpiTYPER MassARRAY system. Gain-and-loss-of-function assays were used to investigate the relationship between TET1 and pGSN in OVCA chemoresponsiveness.
Results: We observed differential protein and mRNA expressions of pGSN and TET1 between sensitive and resistant OVCA cells and cisplatin reduced their expression in sensitive but not in resistant cells. We observed hypomethylation at pGSN promoter upstream region in resistant cells compared to sensitive cells. Pharmacological inhibition of DNMTs increased pGSN protein levels in sensitive OVCA cells and decreased their responsiveness to cisplatin, however we did not observe any difference in methylation level at pGSN promoter region. TETs inhibition resulted in hypermethylation at multiple CpG sites and decreased pGSN protein level in resistant OVCA cells which was also associated with enhanced response to cisplatin, findings that suggested the methylation role of TETs in the regulation of pGSN expression in OVCA cells. Further, we found that TET1 is inversely related to pGSN but positively related to chemoresponsiveness of OVCA cells.
Conclusion: Our findings broaden our knowledge about the epigenetic regulation of pGSN in OVCA chemoresistance and reveal a novel potential target to re-sensitize resistant OVCA cells. This may provide a future therapeutic strategy to improve the overall OVCA patient survival.
... Furthermore, SORT1 may be a druggable target for other diseases with a lysosomal component, such as Parkinson's disease or even aging. Since the efficacious doses for lysosomal benefits are orders of magnitude lower than those used to modulate other SORT1-dependent functions, 69,[90][91][92] it is likely that beneficial responses could be activated without interrupting normal homeostatic functions. ...
Lysosomal storage disorders (LSDs) are a genetically and clinically diverse group of diseases characterized by lysosomal dysfunction. Batten disease is a family of severe LSDs primarily impacting the central nervous system. Here we show that AF38469, a small molecule inhibitor of sortilin, improves lysosomal and glial pathology across multiple LSD models. Live-cell imaging and comparative transcriptomics demonstrates that the transcription factor EB (TFEB), an upstream regulator of lysosomal biogenesis, is activated upon treatment with AF38469. Utilizing CLN2 and CLN3 Batten disease mouse models, we performed a short-term efficacy study and show that treatment with AF38469 prevents the accumulation of lysosomal storage material and the development of neuroinflammation, key disease associated pathologies. Tremor phenotypes, an early behavioral phenotype in the CLN2 disease model, were also completely rescued. These findings reveal sortilin inhibition as a novel and highly efficacious therapeutic modality for the treatment of multiple forms of Batten disease.
... Plasma gelsolin (pGSN; also known as secreted GSN) is a multi-functional actin-binding protein and the secreted isoform of the GSN gene [7][8][9]. pGSN is implicated in the progression, chemoresistance, and metastasis of a plethora of cancer types including OVCA [10][11][12][13][14][15][16][17][18]. We have previously demonstrated that pGSN is highly expressed in chemoresistant OVCA tumors and transported via small extracellular vesicles (sEVs) [10,15,16]. ...
Background:
Ovarian cancer (OVCA) is the most fatal gynecological cancer with late diagnosis and plasma gelsolin (pGSN)-mediated chemoresistance representing the main obstacles to treatment success. Since there is no reliable approach to diagnosing patients at an early stage as well as predicting chemoresponsiveness, there is an urgent need to develop a diagnostic platform for such purposes. Small extracellular vesicles (sEVs) are attractive biomarkers given their potential accuracy for targeting tumor sites.
Methods:
We have developed a novel biosensor which utilizes cysteine-functionalized gold nanoparticles that simultaneously bind to cisplatin (CDDP) and plasma/cell-derived EVs, affording us the advantage of predicting OVCA chemoresponsiveness, and early diagnosis using surface-enhanced Raman spectroscopy.
Results:
We found that pGSN regulates cortactin (CTTN) content resulting in the formation of nuclear- and cytoplasmic-dense granules facilitating the secretion of sEVs carrying CDDP; a strategy used by resistant cells to survive CDDP action. The clinical utility of the biosensor was tested and subsequently revealed that the sEV/CA125 ratio outperformed CA125 and sEV individually in predicting early stage, chemoresistance, residual disease, tumor recurrence, and patient survival.
Conclusion:
These findings highlight pGSN as a potential therapeutic target and provide a potential diagnostic platform to detect OVCA earlier and predict chemoresistance; an intervention that will positively impact patient-survival outcomes.
... cGSN is universally expressed, but cells expressing pGSN are less common [38]. Skeletal, cardiac, and smooth muscles are identified as the main sources of GSN in blood [50]; however, malignant tumor cells also produce higher levels of pGSN [51,52]. Detection of only cGSN expression in tumor tissues is challenging given the antibodies and strategies used target the c-terminal regions which is similar in both pGSN and cGSN. ...
Ovarian Cancer (OVCA) is the most fatal gynecologic cancer and has a 5-year survival rate less than 45%. This is mainly due to late diagnosis and drug resistance. Overexpression of plasma gelsolin (pGSN) is key contributing factor to OVCA chemoresistance and immunosuppression. Gelsolin (GSN) is a multifunctional protein that regulates the activity of actin filaments by cleavage, capping, and nucleation. Generally, it plays an important role in cytoskeletal remodeling. GSN has three isoforms: cytosolic GSN, plasma GSN (pGSN), and gelsolin-3. Exosomes containing pGSN are released and contribute to the progression of OVCA. This review describes how pGSN overexpression inhibits chemotherapy-induced apoptosis and triggers positive feedback loops of pGSN expression. It also describes the mechanisms by which exosomal pGSN promotes apoptosis and dysfunction in tumor-killing immune cells. A discussion on the potential of pGSN as a prognostic, diagnostic, and therapeutic marker is also presented herein.
... Indeed, a previous study showed that the pGSN-induced apoptosis in CD8 T cells can be attributed to the binding of pGSN to sortilin, which is essential for forming lipid rafts to consolidate interactions of receptors and serves as a link between prostate cancer cells and CD8 T cells, thereby promoting the Fas/FasL interactions for cell death signaling transduction in CD8 T cells. 55 Furthermore, a recent study demonstrated that pGSN can decrease dendritic cell (DC)-mediated cross-presentation of dead cellderived antigens. 56 It was also discovered that pGSN suppresses the cross-presentation of DCs via reducing the binding of actin filaments to dendritic cell NK lectin group receptor-1 (DNGR-1). ...
The protein expression of gelsolin, an actin scavenger controlling cytoskeletal remodeling, cell morphology, differentiation, movement, and apoptosis, has been found to be significantly decreased in several pathological conditions including neurodegenerative diseases, inflammatory disorders, and cancers. Its extracellular isoform, called plasma gelsolin (pGSN), is one of the most abundant plasma proteins in the circulation, and has emerged as a novel diagnostic biomarker for early disease detection. Current evidence reveals that gelsolin can function as either an oncoprotein or a tumor suppressor depending on the carcinoma type. Interestingly, recent studies have shown that pGSN is also involved in immunomodulation, revealing the multifunctional roles of pGSN in tumor progression. In this review, we discuss the current knowledge focusing on the roles of gelsolin in inflammation and wound healing, cancers, and tumor microenvironment. Future prospects of pGSN related studies and clinical application are also addressed.
... OVCA patients whose tumor tissues show lower expression of pGSN mRNA have prolonged progression-free survival compared with those with higher pGSN mRNA expression [9]. In addition to OVCA, pGSN has been implicated in other types of cancer such as breast, prostate and colon [9,15,[23][24][25][26][27]. Recently, we have also demonstrated that aside from the tumor expression of pGSN, circulating pGSN is a novel candidate for the early detection of OVCA, as well as the prediction of residual disease [28]. ...
... These findings are consistent with our previous studies, where increased pGSN mRNA levels were associated with poor prognosis regardless of treatment regimen or the OVCA histological subtype [9]. This also supports the findings from other studies in which pGSN levels were implicated in head-and-neck, ovarian and prostate cancers [9,23,24,26,27]. Thus, targeting pGSN by way of monoclonal antibodies or small-molecule inhibitors could provide therapeutic advantages to patients with OVCA regardless of their ethnic background. ...
... These responses were the opposite when pGSN was over-expressed in chemosensitive cells. These observations support our hypothesis and are also consistent with other studies where exosomal pGSN suppresses the anti-tumor functions of immune cells such as CD8+ T cells and natural killer T cells [24,51]. Our findings are also consistent with other studies where recombinant human pGSN reduced inflammatory cytokines such as iNOS, TNFα and IL-6 in LPS-stimulated human keratinocytes [52], RAW264.7 [53], peritoneal macrophages [53] and THP-1 cells [53] as well as carrageenan-induced paw edema in mice [54]. ...
Simple Summary
Ovarian cancer is one of the deadliest female cancers with very poor survival, primarily due to late diagnosis, recurrence and chemoresistance. Although the over-expression of plasma gelsolin (pGSN) protects ovarian cancer cells from chemotherapy-induced death, its immunological role in the tumor microenvironment is less explored. Here, we demonstrate that pGSN over-expression downregulates the anti-tumor functions of M1 macrophages, an effect that contributes to chemoresistance and poor patient survival. This study demonstrates the novel inhibitory role of pGSN on tumor-infiltrated M1 macrophages and also offers new insights in maximizing the effectiveness of immunotherapy for ovarian cancer patients.
Abstract
Ovarian cancer (OVCA) is the most lethal gynaecological cancer with a 5-year survival rate less than 50%. Despite new therapeutic strategies, such as immune checkpoint blockers (ICBs), tumor recurrence and drug resistance remain key obstacles in achieving long-term therapeutic success. Therefore, there is an urgent need to understand the cellular mechanisms of immune dysregulation in chemoresistant OVCA in order to harness the host’s immune system to improve survival. The over-expression of plasma gelsolin (pGSN) mRNA is associated with a poorer prognosis in OVCA patients; however, its immuno-modulatory role has not been elucidated. In this study, for the first time, we report pGSN as an inhibitor of M1 macrophage anti-tumor functions in OVCA chemoresistance. Increased epithelial pGSN expression was associated with the loss of chemoresponsiveness and poor survival. While patients with increased M1 macrophage infiltration exhibited better survival due to nitric-oxide-induced ROS accumulation in OVCA cells, cohorts with poor survival had a higher infiltration of M2 macrophages. Interestingly, increased epithelial pGSN expression was significantly associated with the reduced survival benefits of infiltrated M1 macrophages, through apoptosis via increased caspase-3 activation and reduced production of iNOS and TNFα. Additionally, epithelial pGSN expression was an independent prognostic marker in predicting progression-free survival. These findings support our hypothesis that pGSN is a modulator of inflammation and confers chemoresistance in OVCA, in part by resetting the relative abundance and function of macrophage subtypes in the ovarian tumor microenvironment. Our findings raise the possibility that pGSN may be a potential therapeutic target for immune-mediated chemoresistance in OVCA.
... 5,6 GSN can play a complex role in apoptosis as the full-length GSN and its C-terminal half are mostly anti-apoptotic, 7,8 whereas the caspase 3-generated N-terminal half is proapoptotic. 9 In pressure overload-mediated cardiomyopathy, PI3Kα/PIP3 was identified as the negative regulator of GSN activity such that loss of PI3Kα increased GSN activity, and amplified degradation of actin filaments and cytoskeletal remodeling in cardiomyocytes in heart failure. 6 Recent studies have proposed involvement of GSN in fibrosis in patients with idiopathic pulmonary fibrosis. ...
... 33 Therefore, it is plausible that the Ang IImediated rise in GSN is upstream of TGFβ1 activation in the myocardium, although the details of this process will require further investigation. Moreover, while different functions for the C-terminal and N-terminal half of GSN have been reported, 7,8 and N-terminal half of GSN, 9 our data indicate that the pro-fibrotic function of GSN is mediated by the full-length protein and not the shorter peptide (C-or N-terminal). ...
Myocardial fibrosis is a characteristic of various cardiomyopathies, and myocardial fibroblasts play a central role in this process. Gelsolin (GSN) is an actin severing and capping protein that regulates actin assembly and may be involved in fibroblast activation. While the role of GSN in mechanical stress‐mediated cardiac fibrosis has been explored, its role in myocardial fibrosis in the absence of mechanical stress is not defined. In this study, we investigated the role of GSN in myocardial fibrosis induced by Angiotensin II (Ang II), a profibrotic hormone that is elevated in cardiovascular disease. We utilized mice lacking GSN (Gsn–/–) and cultured primary adult cardiac fibroblasts (cFB). In vivo, Ang II infusion in mice resulted in significantly less severe myocardial fibrosis in Gsn–/– compared with Gsn+/+ mice, along with diminished activation of the TGFβ1‐Smad2/3 pathway, and reduced expression of cardiac extracellular matrix proteins (collagen, fibronectin, periostin). Moreover, Gsn‐deficient hearts exhibited suppressed activity of the AMPK pathway and its downstream effectors, mTOR and P70S6Kinase, which could contribute to the suppressed TGFβ1 activity. In vitro, the Ang II‐induced activation of cFBs was reduced in Gsn‐deficient fibroblasts evident from decreased expression of αSMA and periostin, diminished actin filament turnover; which also exhibited reduced activity of the AMPK‐mTOR pathway, and P70S6K phosphorylation. AMPK inhibition compensated for the loss of GSN, restored the levels of G‐actin in Gsn–/– cFBs and promoted activation to myofibroblasts by increasing αSMA and periostin levels. This study reveals a novel role for GSN in mediating myocardial fibrosis by regulating the AMPK‐mTOR‐P70S6K pathway in cFB activation independent from mechanical stress‐induced factors.
... Out of the 1,506 identified proteins regulated during neuroendocrine differentiation, the lipid-binding actin-regulatory protein GSN was chosen for further investigation. GSN is widely expressed intracellularly, including in the cytoplasm and mitochondria, and its expression is altered in several tumour types, including of the bladder, colon, breast, and prostate (22,23). GSN inhibits apoptosis by stabilising mitochondria and has been shown to act as a co-regulator for nuclear receptors, including STAT3 and AR (13,14,24). ...
Background/aim:
Interleukin 6 (IL6) is increased in patients with progressive prostate cancer and induces its transdifferentiation to neuroendocrine prostate cancer. Neuroendocrine prostate cancer has become one of the greatest challenges in treating castration-resistant disease and is linked to poor prognosis. It is necessary to understand better the cellular events associated with IL6-mediated neuroendocrine differentiation to prevent it and identify potential new therapeutic targets.
Materials and methods:
In the present study, an IL6-inducible neuroendocrine differentiation model established specifically for this purpose was applied using LNCaP cells. Proteomics and western blot analyses were used to identify proteins involved in neuroendocrine differentiation. Subsequently, the role of gelsolin (GSN) in the neuroendocrine differentiation model was characterized (knock-down analyses, microscopic co-localization analyses, apoptosis assay) and GSN expression levels in patient material were investigated.
Results:
This study revealed that GSN is a crucial factor in the neuroendocrine differentiation process.
Conclusion:
It was shown that siRNA-mediated knock-down of GSN can inhibit neuroendocrine differentiation, making it a valid target for preventing IL6-mediated neuroendocrine differentiation.
... Cells can additionally produce and secrete sGSN (Kwiatkowski et al., 1988b) by making use of an alternatively spliced exon in the GSN gene that encodes a signal peptide (Kwiatkowski et al., 1988a(Kwiatkowski et al., , 1986. It is reported that human cancer cells can secrete large amounts of sGSN, leading to extracellular concentrations in the TME of up to 400 mg/mL (Asare-Werehene et al., 2020;Chen et al., 2017;Tsai et al., 2012), higher than the normal circulating levels in plasma of 150-300 mg/mL (Smith et al., 1987). Cancer cell secretion of sGSN is associated with immune escape through a poorly defined mechanism (Asare-Werehene et al., 2020;Chen et al., 2017). ...
... It is reported that human cancer cells can secrete large amounts of sGSN, leading to extracellular concentrations in the TME of up to 400 mg/mL (Asare-Werehene et al., 2020;Chen et al., 2017;Tsai et al., 2012), higher than the normal circulating levels in plasma of 150-300 mg/mL (Smith et al., 1987). Cancer cell secretion of sGSN is associated with immune escape through a poorly defined mechanism (Asare-Werehene et al., 2020;Chen et al., 2017). ...
... Many cells can synthesize sGSN in addition to cytoplasmic gelsolin (cGSN), and sGSN can account for more than half of total gelsolin transcript expression in some tissues ( Figures S3F-S3H). In line with this, several human cancers have been reported to secrete sGSN (Asare-Werehene et al., 2020;Chen et al., 2017;Tsai et al., 2012), unlike the murine cancer cell lines used in this study (Figure S3I). We therefore overexpressed sGSN in MCA-205 LA-OVA-mCherry cells ( Figure S3J) and challenged WT and sGsn À/À mice. ...
Cross-presentation of antigens from dead tumor cells by type 1 conventional dendritic cells (cDC1s) is thought to underlie priming of anti-cancer CD8+ T cells. cDC1 express high levels of DNGR-1 (a.k.a. CLEC9A), a receptor that binds to F-actin exposed by dead cell debris and promotes cross-presentation of associated antigens. Here, we show that secreted gelsolin (sGSN), an extracellular protein, decreases DNGR-1 binding to F-actin and cross-presentation of dead cell-associated antigens by cDC1s. Mice deficient in sGsn display increased DNGR-1-dependent resistance to transplantable tumors, especially ones expressing neoantigens associated with the actin cytoskeleton, and exhibit greater responsiveness to cancer immunotherapy. In human cancers, lower levels of intratumoral sGSN transcripts, as well as presence of mutations in proteins associated with the actin cytoskeleton, are associated with signatures of anti-cancer immunity and increased patient survival. Our results reveal a natural barrier to cross-presentation of cancer antigens that dampens anti-tumor CD8+ T cell responses.
