Expression Of CST1 Research Articles

Cystatin SN (CST1) Is a Poor Independent Prognostic Biomarker for Gastrointestinal Diffuse Large B-Cell Lymphoma.

BACKGROUND Gastrointestinal diffuse large B-cell lymphoma (GI-DLBCL) is the most common histological subtype of extra-nodal DLBCL, but the risk factors, prognostic biomarkers, histopathological classifications, and treatment strategies have not had significant progress. Emerging evidence shows that cystatin SN (CST1) is involved in tumor progression in several cancer types, but its role in GI-DLBCL has not been revealed. MATERIAL AND METHODS We established a cohort consisting of 84 patients with GI-DLBCL who underwent surgical resection. The expression of CST1 in the cohort was investigated by immunohistochemistry, which divided the patients into subgroups with low or high expression of CST1. Moreover, the CST1 expression in GI-DLBCL tissues or adjacent GI tissues were compared with RT-qPCR. The correlation between CST1 expression and clinicopathological factors was analyzed with the chi-square test. The prognostic significance of CST1 was estimated by univariate and multivariate analysis, and statistical significance was analyzed with the log-rank test. RESULTS CST1 was aberrantly upregulated in GI-DLBCL tissues compared with in non-tumor GI tissues. High expression of CST1 indicated poor prognosis of GI-DLBCL (P=0.012), and CST1 can be regarded as an independent prognostic biomarker of GI-DLBCL (hazard ratio=3.07). In our study, serum lactate dehydrogenase (P=0.002), performance status (P=0.003), Lugano stage (P=0.002), and International Prognostic Index (P=0.001) were also prognostic factors of GI-DLBCL. CONCLUSIONS CST1 is an independent prognostic biomarker of GI-DLBCL, indicating unfavorable prognosis. Our results suggested that CST1 detection can be a promising method to stratify high-risk patients and guide individual treatment.

Clinical implications and mechanism of CST1 in gastric carcinoma based on database screening.

Gastric cancer (GC) remains one of the most common malignant tumours worldwide, with extremely high morbidity and mortality rates. An in-depth understanding of the pathogenesis of GC is key to the future diagnosis and treatment of GC. In this study, we analysed the differentially expressed genes (DEGs) in gastric carcinoma (GC) through GEO database and their clinical implications, with the aim of providing clinical reference and guidance. We selected the GSE118916 dataset for bioinformatics analysis and identified a total of 3231 DEGs. Keywords, including extracellular region, vesicle, protein digestion and absorption, ECM-receptor interaction, etc., of DEGs can be seen by the GO and KEGG enrichment analysis. The online database determined up-regulated CST1 in GC and some other tumors, as well as a close connection between CST1 with patient prognosis. Subsequently, we collected a number of GC clinical cases and examined the expression of CST1, which was seen to be highly expressed in GC, with a favorable diagnostic effect on the occurrence of GC (P<0.05) and a strong correlation with TNM stage, tumor invasion, tumor diameter and differentiation (P<0.05). In other words, CST1 is closely related to the occurrence and development of GC, and has the potential to be a breakthrough in the diagnosis and treatment of GC in the future.

Canonical Wnt signaling pathway (WSP) alterations in metastatic prostate cancer.

221 Background: WSP aberrations have been implicated in the progression and treatment resistance of metastatic prostate cancer (mPCa). Sustained exposure of PCa to androgen deprivation has been shown to regulate the canonical WSP, induce beta-catenin expression and stabilization, and promote androgen independence. This study interrogates a large dataset to characterize the molecular and immune landscape of canonical WSP-altered mPCa and associations with survival outcomes. Methods: We examined PCa patients who underwent tissue-based DNA and RNA sequencing through a CLIA-certified commercial assay (Caris Life Sciences). Comprehensive genomic profiling included next-generation sequencing (NGS) of DNA (592-gene panel or whole exome) and RNA (whole transcriptome), on tissue samples from primary prostatic and/or metastatic sites. Tumor samples were categorized as having aberrant canonical Wnt signaling (WSP-act) if they harbored activating mutations in CTNNB, pathogenic RSPO2 fusions, or inactivating mutations in either APC or RNF43. Subset analysis was conducted in mPCa samples with microsatellite stability (MSS), after excluding those with RNF43 (p.G659fs*) mutations which are passenger events in MSI-high cancers. Statistical significance was determined using Fisher's Exact or X2 tests with Benjamini–Hochberg correction. Overall survival (OS) data was obtained from insurance claims and was analyzed using Kaplan-Meier estimation. Results: Of all PCa samples (4,150) (N = 4,150), 17.4% (n = 722) were classified as WSP-act; 299 (41.4%) were from the primary tumor and 423 (58.6%) were from metastatic sites. WSP-act tumors were more prevalent in brain (46%), liver (31%), lung (31%) and bone (25%) metastases compared to primary prostate cancers (10%). The MSS mPCa subgroup (N=1,638) comprised 321 WSP-act and 1,317 WSP-WT tumors. WSP-act mPCa exhibited more SPOP mutations (14.2% vs. 6.3%, p &lt; 0.001) as well as higher mRNA expression of CST1, NKD1, and ODAM (known canonical WSP activators) compared to WSP-WT cases. M2 macrophages predominated the tumor microenvironment, with a higher median fraction in WSP-act tumors compared to WSP-WT (7.2 vs. 6.1%, p &lt; 0.001). ROR1 gene expression was significantly elevated in WSP-act tumors from both primary and metastatic sites. There was no significant difference in OS outcomes between WSP-act and WSP-WT mPCa patients. Conclusions: WSP-act prostate cancer demonstrated a pronounced upregulation of ROR1 gene expression, underscoring its potential involvement in the crosstalk between the canonical and non-canonical Wnt signaling pathways. Additionally, the augmented levels of M2 macrophages in WSP-act tumors, combined with the reported role of ROR1 in tumor immunosuppression, suggests that ROR1 may contribute to immune evasion in WSP-act mPCa. Our findings may provide rationale for developing novel therapeutic strategies targeting Wnt-activated prostate cancers.

Abstract B056: Chronic hypoxia in TNBC breast cancer induces development of a novel population of CD24+/CD49b-high cells characterized by high expression of CST1

Abstract Triple-negative breast cancer (TNBC) is the subtype of breast cancer that has the worst clinical outcome due to the absence of specific targeting agents. TNBC is highly heterogeneous and within the tumor microenvironment, hypoxia emerges as a pivotal factor contributing to its aggressive biology. Solid tumors experience a fluctuating oxygen supply, leading to the formation of zones with prolonged oxygen deprivation. There have been few studies describing the response to chronic hypoxia [7-14 days] and this project investigates how chronic hypoxia contributes to tumour heterogeneity in a temporal manner. We performed scRNA-seq analysis on MDA-MB-231 cells subjected to a 14-day hypoxia treatment at 1% oxygen. We collected samples from both normoxia and hypoxia conditions on Days 1, 2, 7, and 14. A total of 40,000 cells were sequenced. There were 6 hypoxic cell clusters which evolved over the time course. Interestingly, chronic hypoxia induces various transient subpopulations. Cells in hypoxia Day 7 grew more slowly, before recovering growth at Day 14, marking a crucial adaptation point at Day 7 in chronic hypoxia. Our study suggests that chronic hypoxia cells conserve energy through G1 cell cycle arrest and Myc suppression as an adaptive mechanism to cope with chronic hypoxia. We also observed a higher expression of cancer stem cell markers [CD44, CXCR4 and KLF4] in hypoxia subpopulations relative to normoxia subpopulations, especially in the chronic hypoxia subpopulations. Notably, we identified a distinct CD24+/CD49b-high population, comprising the largest proportion of the hypoxic Day 7 samples which disappears by Day 14. This population is characterised by the upregulation of cystatin family genes- CST 1, 4 and 7 and may be pro-metastatic [upregulation of EMP1, ST3GAL6 and KRT19 genes] compared to earlier and later hypoxia phases. Interestingly, KRT19 is more abundant in peripheral blood of breast cancer patients with node metastasis, although its role in stemness of breast cancer is controversial. The heterogeneity we found here may explain this, with the existence of a transient population. Chronic hypoxia could perhaps have a role in reprogramming cancer stem cell-like cells into a pro-metastatic state. In summary, our study provides insights on how hypoxia induces protective translational reprogramming and drives plasticity in cancer cells. Understanding these processes may facilitate the development of targeted treatments to combat therapy resistance in TNBC. Citation Format: May Sin Ke, Badran Elshenawy, Anjali Arora, Helen Sheldon, Adrian Harris, Francesca Buffa. Chronic hypoxia in TNBC breast cancer induces development of a novel population of CD24+/CD49b-high cells characterized by high expression of CST1 [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Advances in Breast Cancer Research; 2023 Oct 19-22; San Diego, California. Philadelphia (PA): AACR; Cancer Res 2024;84(3 Suppl_1):Abstract nr B056.

TFAP2C Activates CST1 Transcription to Facilitate Breast Cancer Progression and Suppress Ferroptosis.

Cystatin SN (CST1) appears to have pro-tumor effects in breast cancer (BC) and is involved in ferroptosis; however, there is no report on the regulation of ferroptosis by CST1 for BC development. The purpose of this study is to investigate the functions and mechanisms operated by CST1 in BC development and ferroptosis. Transcription Factor Activator Protein 2γ (TFAP2C) and CST1 levels in BC tissues and estrogen receptor (ER)+ cells were quantified by RT-qPCR and western blotting. After knocking down TFAP2C and CST1 expression in MCF7 and T47D cells, the proliferation, colony formation ability, apoptosis, and cell cycle were assessed. Ferroptosis was verified by detecting glutathione peroxidase 4 (GPX4) and 4-hydroxy-2-nonenal (4HNE) levels. The kits were used to test Fe2+, reactive oxygen species, malondialdehyde, and glutathione levels, and ultrastructure of mitochondria was observed through transmission electron microscope. Dual-luciferase reporter assay and chromatin immunoprecipitation test were carried out to investigate the interaction of TFAP2C and CST1. A transplanted tumor model was established to explore the function of TFAP2C in tumorigenesis by quantifying TFAP2C, CST1, Ki67, and GPX4 levels through western blotting and immunochemistry after silencing TFAP2C. TFAP2C and CST1 were predominantly expressed in BC cells. Silencing of TFAP2C or CST1 expression suppressed ER+ BC cell proliferation, promoted apoptosis and ferroptosis, and blocked cell cycle transition from G1 phase to S phase. TFAP2C knockdown in transplanted tumors inhibited tumor growth and GPX4 level. Upregulating CST1 nullified the anti-tumor effects of TFAP2C knockdown and TFAP2C promoted CST1 expression through transcription activation. TFAP2C activates CST1 transcription to facilitate BC development and block ferroptosis.

SPI1-Mediated Upregulation of the CST1 Gene as an Independent Poor Prognostic Factor Accelerates Metastasis in Esophageal Squamous Cell Carcinoma (ESCC) by Interacting with MMP2.

Esophageal squamous cell carcinoma (ESCC) is a highly lethal tumor type, but studies on the ESCC tumor microenvironment are limited. We found that cystatin SN (CST1) plays an important role in the ESCC tumor microenvironment. CST1 has been reported to act as an oncogene in multiple human cancers, but its clinical significance and underlying mechanism in ESCC remain elusive. We performed ESCC gene expression profiling with data from RNA-sequencing and public databases and found CST1 upregulation in ESCC. Then, we assessed CST1 expression in ESCC by RT‒qPCR and Western blot analysis. In addition, immunohistochemistry (IHC) and enzyme-linked immunosorbent assay (ELISA) were used to estimate the expression of CST1 in ESCC tissue and serum. Moreover, further functional experiments were conducted to verify that the gain and loss of CST1 in ESCC cell lines significantly influenced the proliferation and metastasis of ESCC. Mass spectrometry, coimmunoprecipitation, and gelatin zymography experiments were used to validate the interaction between CST1 and matrix metalloproteinase 2 (MMP2) and the mechanism of CST1 influence on metastasis in ESCC. Here, we found that CST1 expression was significantly elevated in ESCC tissues and serum. Moreover, compared with patients with low CST1 expression, patients with high CST1 expression had a worse prognosis. Overall survival (OS) and disease-free survival (DFS) were significantly unfavorable in the high CST1 expression subgroup. Likewise, the CST1 level was significantly increased in ESCC serum compared with healthy control serum, indicating that CST1 may be a potential serum biomarker for diagnosis, with an area under the curve (AUC) = 0.9702 and p < 0.0001 by receiver operating curve (ROC) analysis. Furthermore, upregulated CST1 can promote the motility and metastatic capacity of ESCC in vitro and in vivo by influencing epithelial mesenchymal transition (EMT) and interacting with MMP2 in the tumor microenvironment (TME). Collectively, the results of this study indicated that high CST1 expression mediated by SPI1 in ESCC may serve as a potentially prognostic and diagnostic predictor and as an oncogene to promote motility and metastatic capacity of ESCC by influencing EMT and interacting with MMP2 in the TME.

Cystatin SN (CST1) as a Novel Salivary Biomarker of Periodontitis.

Identification of biomarkers could help in assessing periodontal health status and monitoring treatment outcomes. Therefore, the aim of this cross-sectional study was to identify potential innovative salivary biomarkers for the diagnosis of periodontitis using an untargeted proteomic approach. Forty-five healthy non-smoker participants diagnosed as having periodontally healthy conditions (H), severe periodontitis (P), and healthy but reduced periodontium after active periodontal treatment (T) were consecutively enrolled (15 per each group) in the study. A higher number of spots were identified in the proteome of unstimulated whole saliva collected from H and T subjects compared with P group, mainly within the range of 8-40 kDa. Protein spots of interest were analysed by MALDI-TOF-MS, allowing the identification of cystatin SN (CST1) isoform, as confirmed by Western blot. CST1 was markedly expressed in the H group, while it was absent in most P samples (p < 0.001). Interestingly, a distinct CST1 expression was observed in saliva from T patients. CST1 was negatively correlated with the percentage of pathological sites (p < 0.001) and was effective in discriminating active periodontitis from healthy periodontal status (whether H or T). Therefore, salivary CST1 may be a promising non-invasive biomarker for periodontal disease diagnosis and monitoring.

Abstract P3-11-02: CST1 Interaction with RAB1B Modulates Tamoxifen resistance of Breast Cancer by Regulating Autophagy

Abstract Background: Breast cancer is a prominent cause of cancer-related death among women worldwide. Approximately,70% of breast cancers (BC) are estrogen and progestogen receptor-positive (HR+) at diagnosis. Adjuvant endocrine therapy is a pivotal component of treatment for this type of patient. Tamoxifen (TAM), a widely recommended drug in endocrine therapy, is confronted with a high risk of recurrence after 5 years of treatment among breast cancer patients, which shows big clinical demands. Therefore, it is urgent to find new targets for tamoxifen resistance therapy. Recently, our team found that enhanced expression of Cystain SN (CST1) was detected in tissues that had undergone tamoxifen treatment appearing to recurrence and metastasis in ER-positive breast cancer patients. However, the molecular mechanisms of modulating tamoxifen resistance remain unknown. Therefore, our team suspected that there might be a correlation between the abnormal expression of CST1 and tamoxifen resistance. To investigate whether CST1 is involved in tamoxifen resistance and its molecular mechanism, we conducted further research. It is critical to elucidate the molecular mechanisms of tamoxifen resistance and to explore a novel effective therapeutic target. Method: Enhanced expression of CST1 was confirmed by immunohistochemistry in breast cancer tissue samples and by quantitative real-time PCR in Tamoxifen-resistant cancer cell lines MCF-7R/T47DR. To further investigate the molecular function of CST1, we knockdown its expression in MCF-7R/T47DR cells by transfecting with the lentiviral particles of shCST1 and corresponding negative control (Shanghai Genechem Co., Ltd.) and overexpressed CST1 in MCF-7/T47D cells using ove-GST-CST1, ove-HA-RAB1B plasmids. The effects of CST1 on cell viability and proliferation in breast cancer cells were detected by cell counting kit-8 and colony formation assays, respectively. The interaction between CST1 and RAB1B was validated by Co-immunoprecipitation and Western blot. Autophagosomes were found using transmission electron microscopy (TEM) along with Western blotting to detect the transformation of LC3-I to LC3-II protein (i.e., the LC3-II/LC3-I ratio) and P62 protein levels. Results: We found that aberrant expression of Cystatin SN (CST1) was identified in ER-positive breast cancer (BC) cells (Figure 1) and which is crucial in contributing to Tamoxifen resistance (Figure 2). The direct promotion of autophagy by RAPA can faciliate cells to endocrine resistance. And knockdown of CST1 not only suppressed autophagy in Tamoxifen-resistant cells but also attenuated the resistance, which determined the correlation of CST1 with autophagy in BC (Figure 3). Rab1b (Ras-related protein Rab-1B), a membrane protein essential for autophagosome formation, was verified to have interaction with CST1 through Coimmunoprecipitation (CO-IP) experiments (Figure 4). Meanwhile, RAB1B expression was also reduced by CST1 knockdown in the resistant cells. The interaction between CST1 and RAB1B induces autophagy which decreases Tamoxifen’s therapeutic efficacy. Furthermore, rescue experiments suggested that CST1 knockdown–induced sensitization in the efficacy of TAM Therapy and decreased autophagy could be restored via RAB1B overexpression.Conclusions: These results indicate that CST1 interacts with RAB1B to facilitate BC resistant to TAM through regulation of autophagy and CST1 might be a potential therapeutic target to overcome endocrine therapy resistance. Figure 1. Enhanced expression of CST1 in Tamoxifen-resistance breast cancer Figure 1. Enhanced expression of CST1 in Tamoxifen-resistance breast cancer Figure 2. CST1 expression is positively correlated with autophagy in ER-positive breast cancer Figure 2. CST1 expression is positively correlated with autophagy in ER-positive breast cancer Figure 3. CST1 promotes cells resistant to tamoxifen therapy by activating auophagy Figure 3. CST1 promotes cells resistant to tamoxifen therapy by activating auophagy Figure 4. CST1 interacts with RAB1B in cell autophagy Figure 4. CST1 interacts with RAB1B in cell autophagy Citation Format: li liu. CST1 Interaction with RAB1B Modulates Tamoxifen resistance of Breast Cancer by Regulating Autophagy [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr P3-11-02.

MiR-942-5p inhibits tumor migration and invasion through targeting CST1 in esophageal squamous cell carcinoma.

Cysteine Protease Inhibitor 1 (CST1), a cystatin superfamily protein with the effect on the inhibition of cysteine protease activity, is reported to be involved in the development of many malignancies. MiR-942-5p has been demonstrated its regulatory effects on some malignancies. However, the roles of CST1 and miR-942-5p on esophageal squamous cell carcinoma (ESCC) are still unknown up to now. The expression of CST1 in ESCC tissues was analyzed by TCGA database, immunohistochemistry, and RT-qPCR, respectively. Matrigel-uncoated or-coated transwell assay was used to determine the effect of CST1 on migration and invasion of ESCC cells. Regulatory effect of miR-942-5p on CST1 was detected by dual luciferase assay. CST1 was ectopically highly expressed in ESCC tissues, and had the effect on promoting the migration and invasion of ESCC cells by upregulating phosphorylated levels of key effectors including MEK1/2, ERK1/2, and CREB in MEK/ERK/CREB pathway. Dual-luciferase assay results showed that miR-942-5p had a regulatory effect on targeting CST1. CST1 plays a carcinogenic role on ESCC, and miR-942-5p can regulate the migration and invasion of ESCC cells by targeting CST1 to downregulate MEK/ERK/CREB signaling pathway, suggesting that miR-942-5p/CST1 axis might be a promising target for diagnosis and treatment of ESCC.

Circ_0001821 Potentiates Cell Growth, Metastasis, and Stemness in Colorectal Cancer by Regulating miR-339-3p/CST1.

Dysregulation of circRNAs is associated with human cancer progression, but its expression pattern and function in cancer are not fully understood. The aim of our study is to investigate the effects of circ_0001821 on colorectal cancer (CRC) proliferation, migration, invasion, and stemness. The expression level of circ_0001821 in CRC tissues and cells was detected by quantitative real-time PCR. The effects of circ_0001821 silencing on the proliferation, migration, invasion, and stemness of CRC cells were examined by cell counting kit-8, 5-Ethynyl-2'-deoxyuridine, transwell, sphere formation, and western blot assays. Bioinformatics and dual-luciferase reporter gene assay were used to verify the relationship between circ_0001821 and miR-339-3p, miR-339-3p and CST1 in CRC cells. Circ_0001821 was highly expressed in CRC tissues and cells. Circ_0001821 silencing inhibited the proliferation, migration, invasion, and stemness of CRC cells, and transfection of miR-339-3p inhibitor partly attenuated this effect. In addition, circ_0001821 can bind miR-339-3p to regulate CST1 expression. Circ_0001821 silencing also curbed tumor growth in vivo. Circ_0001821 promoted CRC cell proliferation, migration, invasion, and stemness by regulating the miR-339-3p/CST1 axis.

CST1 inhibits ferroptosis and promotes gastric cancer metastasis by regulating GPX4 protein stability via OTUB1

Metastasis is an important factor contributing to poor prognosis in patients with gastric cancer; yet, the molecular mechanism leading to this cell behavior is still not well understood. In this study, we explored the role of cysteine protease inhibitor SN (Cystatin SN, CST1) in promoting gastric cancer metastasis. We hypothesized that CST1 could regulate gastric cancer progression by regulating GPX4 and ferroptosis. Whole transcriptome sequencing suggested that the expression of CST1 was significantly increased in metastatic cancer, and high CST1 expression was correlated with a worse prognosis. Our data further confirmed that the overexpression of CST1 may significantly promote the migration and invasion of gastric cancer cells in vitro and enhance liver, lung, and peritoneal metastasis of gastric cancer in nude mice. Meanwhile, high expression of CST1 promoted the epithelial-mesenchymal transition (EMT) of gastric cancer cells. Mechanistically, a co-immunoprecipitation experiment combined with mass spectrometry analysis confirmed that CST1 could interact with GPX4, a key protein regulating ferroptosis. CST1 relieves GPX4 ubiquitination modification by recruiting OTUB1, improving GPX4 protein stability and reducing intracellular reactive oxygen species (ROS), thereby inhibiting ferroptosis and, in turn, promoting gastric cancer metastasis. Moreover, clinical data suggested that CST1 is significantly increased in peripheral blood and ascites of gastric cancer patients with metastasis; multivariate Cox regression model analysis showed that CST1 was an independent risk factor for the prognosis of gastric cancer patients. Overall, our results elucidated a critical pathway through which high CST1 expression protects gastric cancer cells from undergoing ferroptosis, thus promoting its progression and metastasis. CST1 may be used as a new oncological marker and potential therapeutic target for gastric cancer metastasis.

Characterization and impact of canonical Wnt Signaling Pathway (WSP) alterations on outcomes of metastatic prostate cancer.

5053 Background: Recurrent alterations in the WSP have been identified in patients with advanced prostate cancer. Aberrant Wnt signaling has been implicated in disease progression and hormonal resistance in prostate cancer. We utilized a multi-institutional real-world dataset to characterize molecular alterations in the canonical WSP in men with prostate cancer, and correlate that with overall survival (OS). Methods: Prostate cancer patients who underwent tissue-based DNA and RNA sequencing utilizing a commercially available CLIA-certified assay (Caris Life Sciences) were investigated. Next generation sequencing (NGS)/ whole exome (WES) and transcriptome sequencing (WTS) was performed on prostate cancer tissue derived from prostatic and/or metastatic sites. Patients with somatic activating mutations in CTNNB, pathogenic fusions in RSPO2, or inactivating mutations in APC or RNF43 were characterized as having aberrant canonical Wnt signaling (WSP-MT). A subset analysis was conducted in metastatic prostate cancer (mPCa) samples with microsatellite stable (MSS) tumors excluding RNF43 (G569fs*) mutations. Comparative analyses were done using Fisher-Exact or X2 tests, and significance was determined by adjusted p value using Benjamini-Hochberg correction (q &lt; 0.05). OS was obtained from insurance claims data and calculated using Kaplan-Meier estimates. Enriched mRNA transcripts were identified as those with an adjusted p value &lt; 0.001, logFC &gt; 1.5, and (-)log10 FDR &gt; 20. Results: Overall, 21.8% (n = 715/3283) of samples were classified as WSP-MT, of which 297 (41.5%) were from primary tumor samples and 418 (58.5%) were from metastatic sites. WSP-MT were highest in metastases to CNS (54.5%, n = 12/22), liver (43.8%, n = 91/208) and lung (42.3%, n = 91/208). Compared to WSP wild-type, WSP-MT tumors had a greater frequency of dMMR/MSI-H status (18% vs. 2%, q &lt; 0.001). In the subset of mPCa, MSS tumors (WSP-MT excluding RNF43 (G569fs*) mutations, n = 318; WSP wild-type n = 951), WSP-MT were enriched for mutations in SPOP (14.3% vs. 6.9%, q = 0.004). In these tumors, WSP-MT samples were most enriched for mRNA expression of CST1, NKD1, AXIN2, and ZNRF3 (all known canonical WSP activators). OS was inferior in mPCa WSP-MT patients compared to WSP wild-type (HR 0.49, 95% CI 0.37-0.64, p &lt; 0.0001). Relative to WSP wild-type cases, OS was shorter from time of enzalutamide/abiraterone/apalutamide start (HR 0.25, 95% CI 0.15-0.43, p = 0.0001), and from first-line taxane chemotherapy (HR 0.47, 95% CI 0.21-1.02, p = 0.052) in pts with WSP-MT. Conclusions: Canonical WSP alterations are enriched in metastatic tumors, with highest prevalence in visceral (CNS, liver, lung) metastases. Clinical outcomes in WSP-mutant cancers are inferior with both hormonal and chemotherapies, heralding an urgent need to develop novel therapeutic strategies for such patients.

Cystatin SN promotes epithelial-mesenchymal transition and serves as a prognostic biomarker in lung adenocarcinoma

BackgroundCystatins are a class of proteins that can inhibit cysteine protease and are widely distributed in human bodily fluids and secretions. Cystatin SN (CST1), a member of the CST superfamily, is abnormally expressed in a variety of tumors. However, its effect on the occurrence and development of lung adenocarcinoma (LUAD) remains unclear.MethodsWe obtained transcriptome analysis data of CST1 from The Cancer Genome Atlas (TCGA) and GSE31210 databases. The association of CST1 expression with prognosis, gene mutations and tumor immune microenvironment was analyzed using public databases. Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG), and Gene Set Enrichment Analysis (GSEA) were performed to investigate the potential mechanisms of CST1.ResultsIn this study, we found that CST1 was highly expressed in lung adenocarcinoma and was associated with prognosis and tumor immune microenvironment. Genetic mutations of CST1 were shown to be related to disease-free survival (DFS) by using the c-BioPortal tool. Potential proteins binding to CST1 were identified by constructing a protein-protein interaction (PPI) network. Gene set enrichment analysis (GSEA) of CST1 revealed that CST1 was notably enriched in epithelial-mesenchymal transition (EMT). Cell experiments confirmed that overexpression of CST1 promoted lung adenocarcinoma cells migration and invasion, while knockdown of CST1 significantly inhibited lung adenocarcinoma cells migration and invasion.ConclusionsOur comprehensive bioinformatics analyses revealed that CST1 may be a novel prognostic biomarker in LUAD. Experiments confirmed that CST1 promotes epithelial-mesenchymal transition in LUAD cells. These findings will help to better understand the distinct role of CST1 in LUAD.

Feno differentiates epithelial gene expression clusters: Exploratory analysis from the MESOS randomized controlled trial

Understanding how asthma biomarkers relate to gene expression signatures could help identify drivers of pathogenesis. This post hoc exploratory analysis of the phase II tralokinumab trial MESOS (ClinicalTrials.gov identifier NCT02449473) aimed to profile baseline airway inflammation in patients with moderate-to-severe asthma. The T2 and T17 gene expression signatures, 3-gene mean and 5-gene mean, were calculated through transcriptomic analysis of baseline bronchial brushing samples. Clustering analysis using these signatures identified 3 distinct inflammatory subgroups: T2LOW/T17HIGH (n= 33), T2HIGH/T17LOW (n= 10), and T2LOW/T17LOW (n= 27). Fractional exhaled nitric oxide (Feno) levels were highest for T2HIGH/T17LOW and lowest for T2LOW/T17HIGH (median= 52.0 [range 42.5-116.3] and median= 18.8 [range 6.6-128.6] ppb, respectively; P= .003). High Feno levels were strongly correlated with high T2 gene expression (Spearman ρ= 0.5537; P< .001). Individual genes differentially expressed in patients with elevated levels of Feno, blood and bronchial submucosal eosinophil counts, and IgE level were explored, with cystatin SN (CST1) being the most upregulated gene in all subgroups (4.49- to 34.42-fold upregulation across clinically defined subgroups with high biomarker expression). Feno level may be useful to differentiate patients with T2 or T17 gene expression. Elevated Feno levels are associated with high CST1 expression.

Role of the Long Intergenic Non-Protein-Coding RNA 1278/miR-185-5p/Cystatin SN Axis in Laryngeal Cancer Cells.

Laryngeal cancer accounts for 25%–30% of tumors in the head and neck. Cystatin SN (CST1) was revealed to show upregulated expression in this cancer, while its functions and upstream pathway remain unknown and need investigation. The current study was designed to solve this problem. We designed short hairpin RNAs targeting CST1 for the loss-of-function assays to probe the influences of CST1 in laryngeal cancer cell proliferation and motility. The upstream competitive endogenous RNA pattern of CST1 was searched using bioinformatics analysis and confirmed by luciferase reporter assays. The experimental results demonstrated that CST1 is a tumor facilitator in laryngeal cancer by stimulating cellular proliferative, migrative, and invasive abilities. CST1 is regulated by the long intergenic non-protein-coding RNA 1278 (LINC01278)/miR-185-5p axis. LINC01278 knockdown and miR-185-5p overexpression exert the same functions as CST1 knockdown to repress cancer cell proliferation, migration, and invasion. In conclusion, LINC01278 plays an oncogenic role in laryngeal cancer by suppressing miR-185-5p to enhance CST1 expression, which enriches the molecular mechanism for the carcinogenesis of laryngeal cancer.

Psoralen inhibits the inflammatory response and mucus production in allergic rhinitis by inhibiting the activator protein1 pathway and the downstream expression of cystatin‑SN.

Psoralen (PSO) exerts anti-inflammatory pharmacological effects and plays an important role in a variety of inflammatory diseases. However, the effects of PSO with allergic rhinitis (AR) are yet to be reported. In the present study, an in vitro AR model was generated by inducing JME/CF15 human nasal epithelial cells with IL-13, after which MTT was used to assess the cytotoxicity of PSO. The expression levels of inflammatory cytokines (granulocyte-macrophage colony-stimulating factor and Eotaxin) were determined by ELISA. Furthermore, the expression of inflammatory IL-6 and −8, as well as mucin 5AC, was assessed by reverse transcription-quantitative PCR and western blotting, and cellular reactive oxygen species were detected using a 2′,7′-dichlorodihydrofluorescein diacetate fluorescent probe. Western blotting was also used to detect the expression and phosphorylation of c-Fos and c-Jun in the activator protein 1 (AP-1) pathway, as well as the expression of cystatin-SN (CST1). PSO inhibited the inflammatory response and mucus production in IL-13-induced JME/CF15 cells. Furthermore, the levels of c-Fos and c-Jun phosphorylation in the AP-1 pathway were decreased in IL-13-induced JME/CF15 cells following PSO treatment. The expression of pathway proteins was activated by the addition of PMA, an AP-1 pathway activator, which concurrently reversed the inhibitory effects of PSO on the inflammatory response and mucus formation. The addition of an AP-1 inhibitor (SP600125) further inhibited pathway activity, and IL-13-induced inflammation and mucus formation was restored. In conclusion, PSO regulates the expression of CST1 by inhibiting the AP-1 pathway, thus suppressing the IL-13-induced inflammatory response and mucus production in nasal mucosal epithelial cells.

α-Enolase Lies Downstream of mTOR/HIF1α and Promotes Thyroid Carcinoma Progression by Regulating CST1.

Novel therapy strategies are crucial for thyroid carcinoma treatment. It is increasingly important to clarify the mechanism of thyroid carcinoma progression. Several studies demonstrate that α-Enolase (ENO1) participates in cancer development; nevertheless, the role of ENO1 in thyroid carcinoma progression remains unclear. In the present study, we found that the expression of ENO1 was upregulated in thyroid carcinoma samples. Proliferation and migration of thyroid carcinoma cells were suppressed by depletion of ENO1; conversely, ENO1 overexpression promoted thyroid carcinoma cell growth and invasion. To elucidate the mechanisms, we found that the hypoxia-related mTOR/HIF1 pathway regulated ENO1 expression. ENO1 regulated the expression of CST1; knockdown of CST1 reversed the tumorigenicity enhanced by ENO1 overexpression. Taken together, our findings provide a theoretical foundation for thyroid carcinoma treatment.

Nasal upregulation of CST1 in dog-sensitised children with severe allergic airway disease.

The clinical presentation of children sensitised to dog dander varies from asymptomatic to severe allergic airway disease, but the genetic mechanisms underlying these differences are not clear. The objective of the present study was to investigate nasal transcriptomic profiles associated with dog dander sensitisation in school children and to reveal clinical symptoms related with these profiles. RNA was extracted from nasal epithelial cell brushings of children sensitised to dog dander and healthy controls. Blood sample analyses included IgE against dog dander, dog allergen molecules, other airborne and food allergens, basophil activation and white blood cell counts. Clinical history of asthma and rhinitis was recorded, and lung function was assessed (spirometry, methacholine provocation and exhaled nitric oxide fraction). The most overexpressed gene in children sensitised to dog dander compared to healthy controls was CST1, coding for Cystatin 1. A cluster of these children with enhanced CST1 expression showed lower forced expiratory volume in 1 s, increased bronchial hyperreactivity, pronounced eosinophilia and higher basophil allergen threshold sensitivity compared with other children sensitised to dog dander. In addition, multi-sensitisation to lipocalins was more common in this group. Overexpression of CST1 is associated with more severe allergic airway disease in children sensitised to dog dander. CST1 is thus a possible biomarker of the severity of allergic airway disease and a possible therapeutic target for the future treatment of airborne allergy.

CST1 Promoted Gastric Cancer Migration and Invasion Through Activating Wnt Pathway.

IntroductionGastric cancer is one of the main reasons of cancer-induced death, exploring the molecular mechanisms of gastric cancer progression is critical for gastric cancer therapy. Here, we studied the role of cysteine protease inhibitor CST1 in gastric cancer progression.MethodsMatrigel-coated or -uncoated transwell assay was used to determine the effect of CST1 on gastric cancer invasion and migration, luciferase reporter system was used to determine the effect of CST1 on Wnt pathway activity.ResultsCST1 had high expression levels in gastric cancer tissues and cells, patients who had high CST1 expression had poor outcome. Overexpression of CST1 increased gastric cancer migration and invasion, while knockdown of CST1 suppressed gastric cancer migration invasion. Mechanism analysis showed CST1 promoted WNT signaling pathway activity, promoted the nuclear translocation of β-catenin and the expression of Wnt signaling targets. Inhibition of Wnt pathway in CST1 overexpression cells inhibited migration and invasion, suggesting CST1 promoted gastric cancer cell migration and invasion through activating the Wnt pathway.ConclusionIn summary, we found CST1 promoted gastric cancer migration and invasion through activating Wnt signaling, providing a novel target for gastric cancer therapy.

Correction to: Elevated expression of CST1 promotes breast cancer progression and predicts a poor prognosis

In Figure 7f the panel for c-myc of MDA-MB-468 was erroneously duplicated. The corrected version of the figure is shown in this paper. This correction does not influence the conclusion of the study and we sincerely apologize for this oversight.