Serpin peptidase inhibitor, clade A member 3 (SERPINA3), is overexpressed in glioma and associated with poor prognosis in glioma patients

Tumor-infiltrating CD8+ sub-populations in primary and recurrent glioblastoma: An in-silico study

Background

Glioblastoma multiforme (GBM) remains an incurable primary brain tumor. CD8+ tumor-infiltrating lymphocytes (TILs) can target malignant cells; however, their anti-tumoral immune responses mostly do not lead to GBM rejection in GBM patients. We profiled the sub-populations of tumor-infiltrating CD8+ T-cells, i.e., naïve, cytotoxic, and exhausted cells, in primary and recurrent GBM tissues and provided a blueprint for future precision-based GBM immunotherapy.

Method

We re-analyzed the raw data of single-cell RNA sequencing on the cells residing in the GBM microenvironment and leveraged tumor bulk RNA analyses to study the significance of CD8+ TILs sub-populations in primary and recurrent GBM. We investigated cell-cell interaction between exhausted CD8+ TILs and other immune cells residing in the primary and recurrent GBM microenvironments and profiled the expression changes following CD8+ TILs' transition from primary GBM to recurrent GBM.

Results

Exhausted CD8+ TILs are the majority of CD8+ TILs sub-populations in primary and recurrent GBM, and cytotoxic CD8+ TILs display decreased expression of inhibitory immune checkpoint (IC) molecules in the primary and recurrent GBM. In the primary and recurrent GBM microenvironment, exhausted CD8+ TILs interact most with tumor-infiltrating dendritic cells.

Conclusion

This study demonstrates the profiles of CD8+ TILs sub-populations in primary and recurrent GBM and provides a proof-of-concept for future precision-based GBM immunotherapy.

CTSC promoted the migration and invasion of glioma cells via activation of STAT3/SERPINA3 axis

Cathepsin C (CTSC) has been reported to be upregulated in several cancers, however, there are still many missing links about the role of CTSC in glioma. To address this knowledge gap, the present study employed bioinformatics analysis, Transwell assay, RT-qPCR and Western blot assays to investigate the expression level of CTSC in glioma tissues, its relationship with survival period, and its effect on the migration and invasion ability of glioma cells. The findings revealed that CTSC was upregulated in glioma and was associated with poor prognosis. Moreover, CTSC was found to promote cell migration and invasion abilities as well as epithelial-mesenchymal transition (EMT). A further study found that CTSC induced SERPINA3 and STAT3 expression in glioma cells. Additionally, we demonstrated that STAT3 signaling mediated upregulation of SERPINA3 expression by CTSC. In sum, our findings suggest that CTSC activates the STAT3/SERPINA3 axis to promote migration and invasion of glioma cells, which may lead to new potential therapeutic approaches for humans with cancer.

Molecular characteristics of incidental lower-grade glioma for treatment decision-making

OBJECTIVE

Several limitations are associated with the early diagnosis and treatment of incidental lower-grade glioma (iLGG), and due to its unknown molecular features, its management is categorized as either the "wait-and-see" strategy or immediate treatment. Therefore, in this study the authors explored iLGG's clinical and molecular landscape to improve its management.

METHODS

The authors retrospectively assessed the differences between the molecular and clinical characteristics of iLGG and symptomatic lower-grade glioma (sLGG) samples filtered based on symptom data corresponding to The Cancer Genome Atlas cohort with mutations. Thereafter, genomic and transcriptomic analysis was performed.

RESULTS

There was no significant difference between iLGG and sLGG with respect to mutation status; however, there was an increase in the interaction between major mutations in sLGG, depending on the histological subtype and the IDH1 mutation status. Furthermore, the IDH1 mutation characteristics corresponding to wild-type glioma were much more obvious in sLGG than in iLGG. Additionally, in sLGG, genes associated with malignancy, including cell proliferation-related, cell migration-related, epithelial-to-mesenchymal transition-related, and negative regulation of cell death-related genes, were significantly upregulated, and groups showing higher expression levels of these genes were associated with worse prognosis. Also, 8 of the 75 identified upregulated genes showed positive correlation with resistance to the drugs that are normally used for glioma treatment, including procarbazine, carmustine, vincristine, and temozolomide.

CONCLUSIONS

The new insights regarding the different molecular features of iLGG and sLGG indicated that the immediate management of iLGG could result in better prognosis than the wait-and-see strategy.

SERPINA3: Stimulator or Inhibitor of Pathological Changes

SERPINA3, also called α-1-antichymotrypsin (AACT, ACT), is one of the inhibitors of serine proteases, one of which is cathepsin G. As an acute-phase protein secreted into the plasma by liver cells, it plays an important role in the anti-inflammatory response and antiviral response. Elevated levels of SERPINA3 have been observed in heart failure and neurological diseases such as Alzheimer's disease or Creutzfeldt-Jakob disease. Many studies have shown increased expression levels of the SERPINA3 gene in various types of cancer, such as glioblastoma, colorectal cancer, endometrial cancer, breast cancer, or melanoma. In this case, the SERPINA3 protein is associated with an antiapoptotic function implemented by adjusting the PI3K/AKT or MAPK/ERK 1/2 signal pathways. However, the functions of the SERPINA3 protein are still only partially understood, mainly in the context of cancerogenesis, so it seems necessary to summarize the available information and describe its mechanism of action. In particular, we sought to amass the existing body of research focusing on the description of the underlying mechanisms of various diseases not related to cancer. Our goal was to present an overview of the correct function of SERPINA3 as part of the defense system, which unfortunately easily becomes the "Fifth Column" and begins to support processes of destruction.

Differences in the Expression Patterns of TGFβ Isoforms and Associated Genes in Astrocytic Brain Tumors

Genes associated with the TGFβ isoforms are involved in a number of different cancers, and their effect on the progression of brain tumors is also being discussed. Using an oligonucleotide microarray method, we assessed differences in expression patterns of genes in astrocytic brain tumor sections from 43 patients at different stages of disease. Quantitative mRNA assessment of the three TGFβ isoforms was also performed by real-time RT-qPCR. Oligonucleotide microarray data were analyzed using the PL-Grid Infrastructure. The microarray analysis showed a statistically significant (p < 0.05) increase in TGFβ1 and TGFβ2 expression in G3/G4 stage relative to G2, whereas real-time RT-qPCR validation confirmed this change only for the TGFβ2 isoform (p < 0.05). The oligonucleotide microarray method allowed the identification of 16 differential genes associated with TGFβ isoforms. Analysis of the STRING database showed that the proteins encoded by the analyzed genes form a strong interaction network (p < 0.001), and a significant number of proteins are involved in carcinogenesis. Differences in expression patterns of transcripts associated with TGFβ isoforms confirm that they play a role in astrocytic brain tumor transformation. Quantitative assessment of TGFβ2 mRNA may be a valuable method to complement the diagnostic process in the future.

HOXA-AS2 enhances GBM cell malignancy by suppressing miR-2116-3p thereby upregulating SERPINA3

Background

Glioblastoma (GBM) is malignant, demanding more attention to the improvement of the diagnosis and therapy. LncRNAs have been implicated in the malignancy of GBM cells.

Methods

HOXA-AS2, miR-2116-3p and SERPINA3 expression levels in GBM tissues and cell lines were detected by qRT-PCR. Western blotting was performed to detect the protein levels of Bax and Bcl-2. Dual-luciferase reporter assay was for detection of relationship among these factors, together with RIP and RNA pull-down. CCK-8, EdU, wound healing and transwell assays were for detection of the role of HOXA-AS2, miR-2116-3p and SERPINA3 in cell viability, proliferation, migration and invasion in GBM, respectively.

Results

HOXA-AS2 and SERPINA3 showed higher level in GBM tissues and cell lines. Low level of HOXA-AS2 attenuated GBM cell growth in vitro. Moreover, the anti-tumor impact of silenced HOXA-AS2 was restored by miR-2116-3p inhibitor, but its tumor-promotional effect could be reversed by silenced SERPINA3.

Conclusion

HOXA-AS2 enhanced GBM cell malignancy through sponging miR-2116-3p and releasing SERPINA3, which might shed light on the diagnosis and therapy for GBM in the future.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-022-09462-y.

Transient response of serpinA3 during cellular stress

We demonstrated that serpinA3c/k relocates from the cytoplasm to the apical tubular membrane (ATM) in chronic kidney disease (CKD), suggesting its secretion in luminal space in pathophysiological contexts. Here, we studied serpinA3c/k expression and secretion under different stressful conditions in vitro and in vivo. HEK-293 cells were transfected with a FLAG-tagged serpinA3c/k clone and exposed to H₂ O₂ or starvation. Both stressors induced serpinA3c/k secretion but with a higher molecular weight. Glycanase treatment established that serpinA3c/k is glycosylated. Site-directed mutagenesis for each of the four glycosylation sites was performed. During cellular stress, serpinA3c/k secretion increased with each mutant except in the quadruple mutant. In rats and patients suffering acute kidney injury (AKI), an atypical urinary serpinA3c/k excretion (uSerpinA3c/k) was observed. In rats with AKI, the greater the induced kidney damage, the greater the uSerpinA3 c/k, together with relocation toward ATM. Our findings show that: (1) serpinA3c/k is glycosylated and secreted, (2) serpinA3c/k secretion increases during cellular stress, (3) its appearance in urine reveals a pathophysiological state, and (4) urinary serpinA3 excretion could become a potential biomarker for AKI.

Prognostic Value of Tumor Mutational Burden Related to Immune Infiltration in Cervical Squamous Cell Carcinoma

Cervical squamous cell carcinoma is one of the most common causes of female cancer deaths worldwide. At present, immunotherapy using immune checkpoint blockade (ICB) has improved the prognosis of many cancer patients, and neoantigens generated by mutations may serve as potential biomarkers for predicting the outcome of ICB therapy. In this study, we identified missense mutations as the most frequent in landscapes of gene mutation in cervical squamous cell carcinoma (CESC) samples. Patients with higher tumor mutation burden (TMB) presented higher overall survival (OS). In addition, there was a significant correlation between the high TMB group and fractions of most immune cells. Univariate and multivariate Cox regression analyses identified five hub genes (IFNG, SERPINA3, CCL4L2, TNFSF15, and IL1R1) that were used to build a prognostic model. In the prognostic model, the low-risk group achieved better OS. Mutations in the five hub genes mainly affected the infiltration level of CD8+ T cells and dendritic cells. In conclusion, our study is valuable for exploring the role of TMB and its relationship with immune infiltration in CESC. Moreover, the prognosis model may help predict the sensitivity of patients to immunotherapy and provide underlying biomarkers for personalized immunotherapy.

Circulating SERPINA3 improves prognostic stratification in patients with a de novo or worsened heart failure

Aims

We investigated the prognostic relevance of serpin peptidase inhibitor, clade A member 3 (SERPINA3) in patients admitted with a de novo or worsened heart failure (HF).

Methods and results

In the first stage, 83 HF‐related left ventricular (LV) transcripts were examined in patients with congestive cardiomyopathy (CCMP, n = 44) who died within 5 years and compared with age‐matched and haemodynamically matched CCMP survivors (n = 39) and controls with normal LV function (n = 17). Among 14 differentially expressed transcripts, myocardial gene and circulating SERPINA3 levels were up‐regulated in non‐survivors vs. survivors (2.40 ± 3.66 vs. 0.36 ± 0.22 units, P < 0.01 and 334.7 ± 138.7 vs. 228.2 ± 83.1 μg/mL, P < 0.01, respectively). While no significant transmyocardial gradient was detected, cytokine stimulation of human endothelial cells induced SERPINA3 secretion. In an independent validation cohort with a de novo or worsened HF (n = 387), circulating SERPINA3 levels > 316 μg/mL were associated with increased all‐cause mortality {hazard ratio [HR] [95% confidence interval (CI)]: 2.4 [1.5–3.9], P = 0.0002} and its composite with unplanned cardiovascular readmission [HR (95% CI): 2.0 (1.2–3.3), P = 0.004]. Patients with elevated SERPINA3 levels and elevated either N‐terminal pro brain natriuretic peptide or ST2 showed worse freedom from both endpoints. In a multivariate analysis, including established clinical risk factors, SERPINA3 remained independent predictor of all‐cause mortality together with age, gender, ST2, glomerular filtration, and pulmonary capillary wedge pressure.

Conclusion

In patients with a de novo or worsened HF, increased SERPINA3 levels > 316 μg/mL are associated with increased mortality or unplanned cardiac readmission. Elevated SERPINA3 levels on top of established clinical predictors appear to identify a subgroup of HF patients at higher mortality risk. Prospective studies should further validate its value in prognostic stratification of HF.

Highly expressed of SERPINA3 indicated poor prognosis and involved in immune suppression in glioma

Introduction

The prognosis of patients with glioma is dismal. It has been reported that Serpin peptidase inhibitor clade A member 3 (SERPINA3) is associated with the mobility and invasion of tumor cells. Our study was designed to explore the value of SERPINA3 messenger RNA (mRNA) expression in the biological process, prognosis, and immune significance in glioma.

Methods

We analyzed the biological functions of SERPINA3 through data from the Chinese Glioma Genome Atlas databases. Differentially expressed genes and enrichment analysis were performed and correlations between SERPINA3 expression and immune cell infiltration were analyzed. Further, we validated the expression and the survival prediction role of SERPINA3 by using tissue microarrays and RNAscope in situ hybridization in 321 gliomas. The correlations between the expression and clinical‐pathological parameters as well as other biomarkers were examined.

Results

Univariate and multivariate regression both indicated that the level of SERPINA3 transcript represented an independent prognostic factor. High levels of SERPINA3 correlated with poor survival in patients with glioma. Expression of SERPINA3 mRNA was observed positively correlated with MCM6, IGFBP2, and FKBP10. Enrichment analysis showed SERPINA3 mainly enriched in immune‐related terms and signaling pathways including MAPK, TNF, P53, PI3K‐Akt, nuclear factor‐κB. Immune infiltration analysis further declare the SERPINA3 expression negatively correlated with levels of Macrophages M1, native CD4⁺ T cell, monocytes, and Mast cell activated. And overexpression of SERPINA3 correlated with low CD4⁺ T cell infiltration in glioma tissues.

Conclusions

SERPINA3 may play a key role in the biological process of glioma cells especially in immune suppression activities. SERPINA3 may serve as an independent survival prediction factor in glioma patients.

Extracellular Vesicles as a Novel Liquid Biopsy-Based Diagnosis for the Central Nervous System, Head and Neck, Lung, and Gastrointestinal Cancers: Current and Future Perspectives

Simple Summary

To improve clinical outcomes, early diagnosis is mandatory in cancer patients. Several diagnostic approaches have been proposed, however, the main drawback relies on the invasive procedures required. Extracellular vesicles (EVs) are bilayer lipid membrane structures released by almost all cells and transferred to remote sites via the bloodstream. The observation that their cargo reflects the cell of origin has opened a new frontier for non-invasive biomarker discovery in oncology. Moreover, since EVs can be recovered from different body fluids, their impact as a Correctdiagnostic tool has gained particular interest. Hence, in the last decade, several studies using different biological fluids have been performed, showing the valuable contributions of EVs as tumour biomarkers, and their improved diagnostic power when combined with currently available tumour markers. In this review, the most relevant data on the diagnostic relevance of EVs, alone or in combination with the well-established tumour markers, are discussed.

Abstract

Early diagnosis, along with innovative treatment options, are crucial to increase the overall survival of cancer patients. In the last decade, extracellular vesicles (EVs) have gained great interest in biomarker discovery. EVs are bilayer lipid membrane limited structures, released by almost all cell types, including cancer cells. The EV cargo, which consists of RNAs, proteins, DNA, and lipids, directly mirrors the cells of origin. EVs can be recovered from several body fluids, including blood, cerebral spinal fluid (CSF), saliva, and Broncho-Alveolar Lavage Fluid (BALF), by non-invasive or minimally invasive approaches, and are therefore proposed as feasible cancer diagnostic tools. In this review, methodologies for EV isolation and characterization and their impact as diagnostics for the central nervous system, head and neck, lung, and gastrointestinal cancers are outlined. For each of these tumours, recent data on the potential clinical applications of the EV’s unique cargo, alone or in combination with currently available tumour biomarkers, have been deeply discussed.

Alpha 1-antichymotrypsin contributes to stem cell characteristics and enhances tumorigenicity of glioblastoma

BACKGROUND

Glioblastomas (GBMs) are the main primary brain tumors in adults with almost 100% recurrence rate. Patients with lateral ventricle proximal GBMs (LV-GBMs) exhibit worse survival compared to distal locations for unknown reasons. One hypothesis is the proximity of these tumors to the cerebrospinal fluid (CSF) and its chemical cues that can regulate cellular phenotype. We therefore investigated the role of CSF on GBM gene expression and the role of a CSF-induced gene, SERPINA3, in GBM malignancy in vitro and in vivo.

METHODS

We utilized human CSF and GBM brain tumor-initiating cells (BTICs). We determined the impact of SERPINA3 expression in glioma patients using The Cancer Genome Atlas (TCGA) database. SERPINA3 expression changes were evaluated at mRNA and protein levels. The effects of knockdown (KD) and overexpression (OE) of SERPINA3 on cell migration, viability and cell proliferation were evaluated. Stem cell characteristics on KD cells were evaluated by differentiation and colony formation experiments. Tumor growth was studied by intracranial and flank injections.

RESULTS

GBM-CSF increased BTIC migration accompanied by upregulation of the SERPINA3 gene. In patient samples and TCGA data, we observed SERPINA3 to correlate directly with brain tumor grade and indirectly with GBM patient survival. SERPINA3 KD induced a decrease in cell proliferation, migration, invasion, and stem cell characteristics, while SERPINA3 OE increased cell migration. In vivo, SERPINA3 KD BTICs showed increased survival in a murine model.

CONCLUSIONS

SERPINA3 plays a key role in GBM malignancy and its inhibition results in a better outcome using GBM preclinical models.

Differential gene expression in peritumoral brain zone of glioblastoma: role of SERPINA3 in promoting invasion, stemness and radioresistance of glioma cells and association with poor patient prognosis and recurrence

PURPOSE

Glioblastoma (GBM) is a highly invasive tumor. Despite advances in treatment modalities, tumor recurrence is common, seen mainly in the peritumoral brain zone (PBZ). We aimed to molecularly characterize PBZ, to understand the pathobiology of tumor recurrence.

METHODS/PATIENTS

We selected eight differentially regulated genes from our previous transcriptome profiling study on tumor core and PBZ. Expression of selected genes were validated in GBM (tumor core and PBZ, n = 37) and control (n = 22) samples by real time quantitative polymerase chain reaction (qPCR). Serine protease inhibitor clade A, member 3 (SERPINA3) was selected for further functional characterization in vitro by gene knockdown approach in glioma cells. Its protein expression by immunohistochemistry (IHC) was correlated with other clinically relevant GBM markers, patient prognosis and tumor recurrence.

RESULTS

The mRNA expression of selected genes from the microarray data validated in tumor core and PBZ and was similar to publicly available databases. SERPINA3 knock down in vitro showed decreased tumor cell proliferation, invasion, migration, transition to mesenchymal phenotype, stemness and radioresistance. SERPINA3 protein expression was higher in PBZ compared to tumor core and also was higher in older patients, IDH wild type and recurrent tumors. Finally, its expression showed positive correlation with poor patient prognosis.

CONCLUSIONS

SERPINA3 expression contributes to aggressive GBM phenotype by regulating pro-tumorigenic actions in vitro and is associated with adverse clinical outcome.

Exome sequencing identifies a recurrent variant in SERPINA3 associating with hereditary susceptibility to breast cancer

BACKGROUND

Breast cancer is strongly influenced by hereditary risk factors. Yet, the known susceptibility genes and genomic loci explain only about half of the familial component of the disease. To identify novel breast cancer predisposing gene defects, here we have performed massive parallel sequencing for Northern Finnish breast cancer cases.

METHODS

Ninety-eight breast cancer cases with indication of hereditary disease susceptibility were exome sequenced. Data filtering strategy focused on predictably deleterious rare variants that were still enriched in the sequenced cohort. Findings were confirmed with additional, geographically matched breast cancer cohorts.

RESULTS

A recurrent heterozygous splice acceptor variant, c.918-1G>C, in SERPINA3, was identified, and it was significantly enriched both in the hereditary (6/201, 3.0%, p = 0.006, OR 5.1, 95% CI 1.7-14.8) and unselected breast cancer cohort (26/1569, 1.7%, p = 0.009, OR 2.8, 95% CI 1.3-6.2). SERPINA3 c.918-1G>C carriers were also significantly more likely to have a rare tumor subtype, medullary breast cancer, than the non-carriers (4/26, 15.4%, p = 0.000014, OR 42.9, 95% CI 11.7-157.1).

CONCLUSION

These findings demonstrate that c.918-1G>C germline variant in SERPINA3 gene, encoding a member of the serine protease inhibitor class, is a novel breast cancer predisposing allele.

Involvement of Extracellular Vesicles in Vascular-Related Functions in Cancer Progression and Metastasis

The primary cause of mortality among patients with cancer is the progression of the tumor, better known as cancer invasion and metastasis. Cancer progression involves a series of biologically important steps in which the cross-talk between cancer cells and the cells in the surrounding environment is positioned as an important issue. Notably, angiogenesis is a key tumorigenic phenomenon for cancer progression. Cancer-related extracellular vesicles (EVs) commonly contribute to the modulation of a microenvironment favorable to cancer cells through their function of cell-to-cell communication. Vascular-related cells such as endothelial cells (ECs) and platelets activated by cancer cells and cancer-derived EVs develop procoagulant and proinflammatory statuses, which help excite the tumor environment, and play major roles in tumor progression, including in tumor extravasation, tumor cell microthrombi formation, platelet aggregation, and metastasis. In particular, cancer-derived EVs influence ECs, which then play multiple roles such as contributing to tumor angiogenesis, loss of endothelial vascular barrier by binding to ECs, and the subsequent endothelial-to-mesenchymal transition, i.e., extracellular matrix remodeling. Thus, cell-to-cell communication between cancer cells and ECs via EVs may be an important target for controlling cancer progression. This review describes the current knowledge regarding the involvement of EVs, especially exosomes derived from cancer cells, in EC-related cancer progression.

Determination of genetic effects of SERPINA3 on important growth traits in beef cattle

Serine protease inhibitor protein 3 (serpin peptidase inhibitor, clade A, member 3, SERPINA3) is a member of the serpin superfamily, probably related to the yield and quality of muscle. This study focuses on the relationship between SERPINA3 gene polymorphism and growth traits in beef cattle. The study first uses sequencing pooled DNA samples (Pool-Seq), PCR-RFLP and Tetra-primer ARMS-PCR techniques to determine the genetic polymorphisms of SERPINA3 in 765 beef cattle. Then, the polymorphic loci were correlated with the growth characters of cattle. Five SNPs (SNP1:A-648G, SNP2:T6496A, SNP3:G2495A, SNP4:T2595A, SNP5:A2615G) were found, located in the promoter, introns 5 and SNP 3, 4, 5 were in exons 2, respectively. The observed He was from 0.44 to 0.5, Ne were approaching 2 (1.78 to 2.00). The maximum and minimum PIC (polymorphism information content) values were 0.37 and 0.34, respectively. The association analysis results showed that the SNPs had a significant height in the chest girth and body length. (p < 0.05 or p < 0.01). This will provide important information for the rapid breeding of Chinese yellow cattle and the establishment of a molecular genetic marker database.

Swainsonine represses glioma cell proliferation, migration and invasion by reduction of miR-92a expression

BACKGROUND

Swainsonine is a natural indolizidine alkaloid, its anti-tumor activity has been widely reported in varied cancers. This study aimed to investigate whether Swainsonine exerted anti-tumor impact on glioma cells, likewise uncovered the relative molecular mechanisms.

METHODS

After administration with diverse concentrations of Swainsonine, cell growth, migration and invasion in U251 and LN444 cells were appraised by the common-used CCK-8, BrdU, flow cytometry and Transwell assays. MiR-92a mimic, inhibitor and the correlative NC were transfected into U251 and LN444 cells, and assessment of miR-92a expression was by utilizing qRT-PCR. Functions of miR-92a in above-mentioned cell biological processes were analyzed again in Swainsonine-treated cells. The momentous proteins of cell cycle, apoptosis and PI3K/AKT/mTOR pathway were ultimately examined by western blot.

RESULTS

Swainsonine significantly hindered cell proliferation through decreasing cell viability, declining the percentage of BrdU cells, down-regulating CyclinD1 and up-regulating p16 expression. Enhancement of percentage of apoptotic cells was presented in Swainsonine-treated cells via activating cleaved-Caspase-3 and cleaved-Caspase-9. Additionally, Swainsonine impeded the abilities of migration and invasion by decreasing MMP-2, MMP-9, Vimentin and E-cadherin. Repression of miR-92a was observed in Swainsonine-treated cells, and miR-92a overexpression overturned the anti-tumor activity of Swainsonine in glioma cells. Finally, western blot assay displayed that Swainsonine hindered PI3K/AKT/mTOR pathway via regulating miR-92a.

CONCLUSIONS

These discoveries corroborated that Swainsonine exerted anti-tumor impacts on glioma cells via repression of miR-92a, and inactivation of PI3K/AKT/mTOR signaling pathway.

Clinical Significance of Extracellular Vesicles in Plasma from Glioblastoma Patients

PURPOSE

Glioblastoma (GBM) is the most common primary brain tumor. The identification of blood biomarkers reflecting the tumor status represents a major unmet need for optimal clinical management of patients with GBM. Their high number in body fluids, their stability, and the presence of many tumor-associated proteins and RNAs make extracellular vesicles potentially optimal biomarkers. Here, we investigated the potential role of plasma extracellular vesicles from patients with GBM for diagnosis and follow-up after treatment and as a prognostic tool.

EXPERIMENTAL DESIGN

Plasma from healthy controls (n = 33), patients with GBM (n = 43), and patients with different central nervous system malignancies (n = 25) were collected. Extracellular vesicles were isolated by ultracentrifugation and characterized in terms of morphology by transmission electron microscopy, concentration, and size by nanoparticle tracking analysis, and protein composition by mass spectrometry. An orthotopic mouse model of human GBM confirmed human plasma extracellular vesicle quantifications. Associations between plasma extracellular vesicle concentration and clinicopathologic features of patients with GBM were analyzed. All statistical tests were two-sided.

RESULTS

GBM releases heterogeneous extracellular vesicles detectable in plasma. Plasma extracellular vesicle concentration was higher in GBM compared with healthy controls (P < 0.001), brain metastases (P < 0.001), and extra-axial brain tumors (P < 0.001). After surgery, a significant drop in plasma extracellular vesicle concentration was measured (P < 0.001). Plasma extracellular vesicle concentration was also increased in GBM-bearing mice (P < 0.001). Proteomic profiling revealed a GBM-distinctive signature.

CONCLUSIONS

Higher extracellular vesicle plasma levels may assist in GBM clinical diagnosis: their reduction after GBM resection, their rise at recurrence, and their protein cargo might provide indications about tumor, therapy response, and monitoring.

SERPINA3 Silencing Inhibits the Migration, Invasion, and Liver Metastasis of Colon Cancer Cells

OBJECTIVE

To investigate the impact of SERPINA3 on the migration, invasion, and liver metastasis of colon cancer cells.

METHODS

Immunohistochemical staining was conducted to determine SERPINA3 expression in the cancer and adjacent normal tissues of 131 patients suffering from colon cancer. In vitro experiment, colon cancer cells with low (HT-29P), intermediate (KM-12C), and high (HT-29LMM, KM-12L4) metastatic potential were obtained to examine SERPINA3 expression levels. Besides, quantitative real-time PCR (qRT-PCR) and Western Blot were performed to detect SERPINA3 expression in HT-29LMM and KM-12L4 cells transfected with SERPINA3 siRNA; Wound-healing and Transwell assays to measure cell migration and invasion, respectively; and ELISA to detect MMP-2 and MMP-9 levels. In vivo experiment, mice with liver metastasis of colon cancer were established to observe the effect of SERPINA3 silencing on liver metastasis. Immunohistochemical assay was applied to evaluate the expressions of Serpina3, Mmp-2, Mmp-9, and proliferating cell nuclear antigen (Pcna) in liver metastasis tissues.

RESULTS

SERPINA3 in colon cancer tissues was higher than in adjacent normal tissues, which was associated with patients' clinicopathological features. Besides, SERPINA3 expression showed a rising trend in low, intermediate, and high metastatic potential colon cancer cells. After KM-12L4 and HT-29LMM cells transfected with SERPINA3 siRNA, the migration and invasive ability of cells, as well as the expression levels of MMP-2 and MMP-9 were all decreased. Moreover, SERPINA3 siRNA could not only reduce live metastasis of mice, but also down-regulate the expression of Mmp-2 and Mmp-9 in liver metastasis tissues.

CONCLUSION

SERPINA3 silencing could inhibit the migration, invasion, and liver metastasis of colon cancer cells.

The PDK1/c‑Jun pathway activated by TGF‑β induces EMT and promotes proliferation and invasion in human glioblastoma

Glioblastoma multiforme (GBM) is the most common primary malignant tumor affecting the human brain. Despite improvements in therapeutic technologies, patients with GBM have a poor clinical result and the molecular mechanisms responsible for the development of GBM have not yet been fully elucidated. 3-phosphoinositide dependent protein kinase 1 (PDK1) is upregulated in various tumors and promotes tumor invasion. In glioma, transforming growth factor-β (TGF‑β) promotes cell invasion; however, whether TGF‑β directly regulates PDK1 protein and promotes proliferation and invasion is not yet clear. In this study, PDK1 levels were measured in glioma tissues using tissue microarray (TMA) by immunohistochemistry (IHC) and RT‑qPCR. Kaplan-Meier analyses were used to calculate the survival rate of patients with glioma. In vitro, U251 and U87 glioma cell lines were used for functional analyses. Cell proliferation and invasion were analyzed using siRNA transfection, MTT assay, RT‑qPCR, western blot analysis, flow cytometry and invasion assay. In vivo, U251 glioma cell xenografts were established. The results revealed that PDK1 protein was significantly upregulated in glioma tissues compared with non-tumorous tissues. Furthermore, the higher PDK1 levels were associated with a large tumor size (>5.0 cm), a higher WHO grade and a shorter survival of patients with GBM. Univariate and multivariate analyses indicated that PDK1 was an independent prognostic factor. In vivo, PDK1 promoted glioma tumor xenograft growth. In vitro, functional analyses confirmed that TGF‑β upregulated PDK1 protein expression and PDK1 promoted cell migration and invasion, and functioned as an oncogene in GBM, by upregulating c‑Jun protein and inducing epithelial-mesenchymal transition (EMT). c‑Jun protein were overexpressed in glioma tissues and positively correlated with PDK1 levels. Moreover, our findings were further validated by the online Oncomine database. On the whole, the findings of this study indicate that in GBM, PDK1 functions as an oncogene, promoting proliferation and invasion.

Identification of blood biomarkers in glioblastoma by SWATH mass spectrometry and quantitative targeted absolute proteomics

Molecular biomarkers in blood are needed to aid the early diagnosis and clinical assessment of glioblastoma (GBM). Here, in order to identify biomarker candidates in plasma of GBM patients, we performed quantitative comparisons of the plasma proteomes of GBM patients (n = 14) and healthy controls (n = 15) using SWATH mass spectrometry analysis. The results were validated by means of quantitative targeted absolute proteomics analysis. As a result, we identified eight biomarker candidates for GBM (leucine-rich alpha-2-glycoprotein (LRG1), complement component C9 (C9), C-reactive protein (CRP), alpha-1-antichymotrypsin (SERPINA3), apolipoprotein B-100 (APOB), gelsolin (GSN), Ig alpha-1 chain C region (IGHA1), and apolipoprotein A-IV (APOA4)). Among them, LRG1, C9, CRP, GSN, IGHA1, and APOA4 gave values of the area under the receiver operating characteristics curve of greater than 0.80. To investigate the relationships between the biomarker candidates and GBM biology, we examined correlations between plasma concentrations of biomarker candidates and clinical presentation (tumor size, progression-free survival time, or overall survival time) in GBM patients. The plasma concentrations of LRG1, CRP, and C9 showed significant positive correlations with tumor size (R² = 0.534, 0.495, and 0.452, respectively).

Differential overexpression of SERPINA3 in human prion diseases

Prion diseases are fatal neurodegenerative disorders with sporadic, genetic or acquired etiologies. The molecular alterations leading to the onset and the spreading of these diseases are still unknown. In a previous work we identified a five-gene signature able to distinguish intracranially BSE-infected macaques from healthy ones, with SERPINA3 showing the most prominent dysregulation. We analyzed 128 suitable frontal cortex samples, from prion-affected patients (variant Creutzfeldt-Jakob disease (vCJD) n = 20, iatrogenic CJD (iCJD) n = 11, sporadic CJD (sCJD) n = 23, familial CJD (gCJD) n = 17, fatal familial insomnia (FFI) n = 9, Gerstmann-Sträussler-Scheinker syndrome (GSS)) n = 4), patients with Alzheimer disease (AD, n = 14) and age-matched controls (n = 30). Real Time-quantitative PCR was performed for SERPINA3 transcript, and ACTB, RPL19, GAPDH and B2M were used as reference genes. We report SERPINA3 to be strongly up-regulated in the brain of all human prion diseases, with only a mild up-regulation in AD. We show that this striking up-regulation, both at the mRNA and at the protein level, is present in all types of human prion diseases analyzed, although to a different extent for each specific disorder. Our data suggest that SERPINA3 may be involved in the pathogenesis and the progression of prion diseases, representing a valid tool for distinguishing different forms of these disorders in humans.