Prognostic relevance of LGALS3BP in human colorectal carcinoma

Aberrant expression of LGALS3BP drives an unfavorable prognosis and more aggressive in HCC via regulating PI3K/AKT signaling

Lectin galactoside-binding soluble 3-binding protein (LGALS3BP) is associated with cancer metastasis and is a promising prognostic marker in neoplasms. In hepatocellular carcinoma (HCC), the prognostic impact and pro-metastatic function of LGALS3BP remain unclear. This study evaluated the endogenous LGALS3BP expression in HCC tissue and its association with prognosis. LGALS3BP protein levels were significantly elevated in clinical HCC tissues and cell lines. Increased LGALS3BP expression was closely associated with disease progression in HCC patients, and they also exhibited an unfavorable prognosis. Furthermore, the knockdown of LGALS3BP inhibited the growth, migration, and invasion of HCC cells in vitro. In mice xenografts, silencing LGALS3BP significantly inhibited tumor cell growth in vivo. Mechanically, upon LGALS3BP depletion, the tumor-suppressive function was dependent on inactivating Phosphatidylinositol 3-kinase (PI3K)/V-akt murine thymoma viral oncogene homolog (AKT) signaling pathway. Collectively, these findings suggest that LGALS3BP employs a pro-tumorigenic function in HCC and may be a promising HCC prognostic marker.

HER-3 surface expression increases in advanced colorectal cancer representing a potential therapeutic target

HER-3 (also known as ErbB-3) is a human epidermal growth factor receptor tyrosine kinases family member, and its expression in CRC (colorectal cancer) tissues was previously associated with poor prognosis. In this study, HER-3 expression was analyzed by immunohistochemistry in two cohorts of early and advanced metastatic CRC patients. The first cohort included 180 patients diagnosed with CRC in absence of lymph nodes or distant metastases (Stage I and Stage II), while the second was obtained from 53 advanced metastatic CRC patients who developed synchronous (SM) and metachronous (MM) liver metastases. In the first early-stage CRC cohort, 86 out of 180 (47.8%) tumors showed membranous expression of HER-3, with a mean percentage of positive tumor cells of 25.7%; conversely, in advanced metastatic CRC primary tumors, HER-3 was detected in all specimens, with a mean percentage of positive tumor cells of 76.1%. Kaplan-Meier curves showed that in the advanced metastatic CRC group, patients with HER-3high tumors had a significantly lower Cancer-Specific Survival (CSS) rate compared to patients with HER-3low tumors (p = 0.021). Importantly, this worse CSS rate was observed only in the MM subgroup of patients with HER-3high tumors (p = 0.002). Multivariate analysis confirmed that high HER-3 expression represents a significant and strong risk factor for death in patients developing MM liver metastases (Hazard Ratio = 64.9; 95% Confidence Interval, 4.7-886.6; p = 0.002). In addition, using a specific anti-HER-3 antibody-drug conjugate, named EV20/MMAF, we showed that HER-3 + CRC cells can be efficiently targeted in vitro and in vivo. Overall, this study confirms that surface HER-3 is highly expressed in CRC and reveals that HER-3 expression increases in metastatic CRC patients compared to early stage. Importantly, the results suggest that HER-3 has a prognostic and therapeutic value in patients developing MM liver metastases.

Suppression of triple-negative breast cancer aggressiveness by LGALS3BP via inhibition of the TNF-α-TAK1-MMP9 axis

Transforming growth factor-β-activated kinase 1 (TAK1), which is highly expressed and aberrantly activated in triple-negative breast cancer (TNBC), plays a pivotal role in metastasis and progression. This makes it a potential therapeutic target for TNBC. Previously, we reported lectin galactoside-binding soluble 3 binding protein (LGALS3BP) as a negative regulator of TAK1 signaling in the inflammatory response and inflammation-associated cancer progression. However, the role of LGALS3BP and its molecular interaction with TAK1 in TNBC remain unclear. This study aimed to investigate the function and underlying mechanism of action of LGALS3BP in TNBC progression and determine the therapeutic potential of nanoparticle-mediated delivery of LGALS3BP in TNBC. We found that LGALS3BP overexpression suppressed the overall aggressive phenotype of TNBC cells in vitro and in vivo. LGALS3BP inhibited TNF-α-mediated gene expression of matrix metalloproteinase 9 (MMP9), which encodes a protein crucial for lung metastasis in TNBC patients. Mechanistically, LGALS3BP suppressed TNF-α-mediated activation of TAK1, a key kinase linking TNF-α stimulation and MMP9 expression in TNBC. Nanoparticle-mediated delivery enabled tumor-specific targeting and inhibited TAK1 phosphorylation and MMP9 expression in tumor tissues, suppressing primary tumor growth and lung metastasis in vivo. Our findings reveal a novel role of LGALS3BP in TNBC progression and demonstrate the therapeutic potential of nanoparticle-mediated delivery of LGALS3BP in TNBC.

Galectin-3 in prostate cancer and heart diseases: a biomarker for these two frightening pathologies?

Galectin-3 (Gal-3) belongs to galectin protein family, a type of β-galactose-binding lectin having more than one evolutionarily conserved domain of carbohydrate recognition. Gal-3 is mainly located in the cytoplasm, but it also enters the nucleus and is secreted into the extracellular environment and biological fluids such as urine, saliva, and serum. It plays an important role in many biological functions, such as angiogenesis, apoptosis, cell differentiation, cell growth, fibrosis, inflammation, host defense, cellular modification, splicing of pre-mRNA, and transformation. Many previous studies have shown that Gal-3 can be used as a diagnostic or prognostic biomarker for heart ailments, kidney diseases, and other major illnesses including cancer. Moreover, it may also play a major role in risk stratification in different diseases, and in this review, we have summarized the potential roles and application of Gal-3 as diagnostic, prognostic, and risk stratifying biomarker from previously reported studies in heart diseases and cancer, with special emphasis on prostate cancer.

LGALS3BP in Microglia Promotes Retinal Angiogenesis Through PI3K/AKT Pathway During Hypoxia

Purpose

Retinal microglia promote angiogenesis and vasculopathy in oxygen-induced retinopathy (OIR); however, its specific molecular mechanism in the formation of retinal angiogenesis remains unclear. The lectin galactoside-binding soluble 3 binding protein (LGALS3BP), a member of the scavenger receptor cysteine-rich (SRCR) domain protein family, is involved in tumor neovascularization, and we therefore hypothesized that LGALS3BP plays an active role in microglia-induced angiogenesis.

Methods

The expression of LGALS3BP in microglia was detected by immunofluorescence, RT-qPCR, and western blotting. Functional assays of human umbilical vein endothelial cells (HUVECs) such as migration, proliferation, and tube formation were measured by Transwell, EdU, and Matrigel assays. Angiogenesis-related factors and PI3K/AKT levels were detected by western blotting. The relationship between LGALS3BP and PI3K or HIF-1α was investigated by immunoprecipitation.

Results

Our results showed that the expression of LGALS3BP was significantly increased in microglia surrounding neovascularization of the OIR mice and was also upregulated in human microglial clone 3 (HMC3) cells after hypoxia. Moreover, HUVECs co-cultured with hypoxic HMC3 cells showed increased migration, proliferation, and tube formation, as well as levels of angiogenesis-related factor. However, the proangiogenic ability and angiogenesis-related factor expression of HMC3 cells was suppressed after silencing LGALS3BP. LGALS3BP induces the upregulation of angiogenesis-related factors through the PI3K/AKT pathway and then promotes angiogenesis in microglia.

Conclusions

Collectively, our findings suggest that LGALS3BP in microglia plays an important role in angiogenesis, suggesting a potential therapeutic target of LGALS3BP for angiogenesis.

Lectin galactoside-binding soluble 3 binding protein mediates methotrexate resistance in choriocarcinoma cell lines

Choriocarcinoma is one of the most aggressive gestational trophoblastic neoplasias (GTN). Methotrexate (MTX) resistance is the main cause of treatment failure in choriocarcinoma. However, the mechanism of MTX resistance in choriocarcinoma is poorly known. This study aims to explore the function of Lectin galactoside-binding soluble 3 binding protein (LGALS3BP) in MTX-resistance in choriocarcinoma cells. Gradual dose escalation of MTX was used to establish MTX-resistant choriocarcinoma cells (JAR-MTX and JEG3-MTX cell lines). RNA-sequencing was used to explore the differentially expressed genes. Plasmids or SiRNA transfection was used to regulate the expression of LGALS3BP. ELISA was used to detect the concentrations of LGALS3BP in the serum of MTX-sensitive and MTX-resistant patients. qRT-PCR, Western blot, and CCK-8 assay were used to determine the effects of LGALS3BP on MTX-resistance in JAR and JEG3 cells. The results showed the relative resistance index (RI) of MTX is 791.50 and 1040.04 in JAR-MTX and JEG3-MTX, respectively. LGALS3BP was up-regulated in MTX-resistant cells compared to original cells in both RNA and protein level. The concentrations of LGALS3BP were higher in the sera of MTX-resistant patients than in MTX-sensitive patients. Knocking down LGALS3BP can reverse the MTX-resistance in JAR-MTX and JEG3-MTX cells. In summary, we preliminarily established two MTX-resistant cells, and performed RNA-sequencing, and found LGALS3BP may play important role in MTX-resistance. Our work not only provides a research tool (MTX-resistant cells) for other researchers, but gives some hint on how MTX resistance is regulated.

Osteosarcoma exocytosis of soluble LGALS3BP mediates macrophages toward a tumoricidal phenotype

This study aimed to elucidate the interactions between osteosarcoma (OS) and M1 macrophages infiltrated into the tumor microenvironment and to explore the underlying mechanisms whereby M1 macrophages influence the growth of OS, so that novel treatments of OS can be developed. A transwell co-culture system, an indirect conditioned medium culture system and two orthotopic bearing OS models were established to assess for the interplay between M1 macrophages and OS. We found that the co-culture of M1 macrophages with OS cells significantly inhibited the growth of the tumor cells by inducing apoptosis. Furthermore, HSPA1L secreted by M1 macrophages exerted this anti-tumor effect through the IRAK1 and IRAK4 pathways. LGALS3BP secreted by OS cells bound to the ligand LGALS3 on M1 macrophages and thereby induced the secretion of Hspa11 via Akt phosphorylation. In vivo experiments demonstrated that the culture supernatant of OS-stimulated M1 macrophages significantly inhibited the growth of OS, whereas silencing Lgals3bp promoted the progression of OS. In conclusion, OS modifies the phenotype of tumor-associated macrophages (TAMs) and thereby influences the apoptosis of OS cells through soluble factors. The modulation of TAMs may be a promising and effective therapeutic approach in OS.

Estrogen receptor-positive breast cancer survival prediction and analysis of resistance-related genes introduction

Background

In recent years, ER+ and HER2- breast cancer of adjuvant therapy has made great progress, including chemotherapy and endocrine therapy. We found that the responsiveness of breast cancer treatment was related to the prognosis of patients. However, reliable prognostic signatures based on ER+ and HER2- breast cancer and drug resistance-related prognostic markers have not been well confirmed, This study in amied to establish a drug resistance-related gene signature for risk stratification in ER+ and HER2- breast cancer.

Methods

We used the data from The Cancer Genoma Atlas (TCGA) breast cancer dataset and gene expression database (Gene Expression Omnibus, GEO), constructed a risk profile based on four drug resistance-related genes, and developed a nomogram to predict the survival of patients with I-III ER+ and HER2- breast cancer. At the same time, we analyzed the relationship between immune infiltration and the expression of these four genes or risk groups.

Results

Four drug resistance genes (AMIGO2, LGALS3BP, SCUBE2 and WLS) were found to be promising tools for ER+ and HER2- breast cancer risk stratification. Then, the nomogram, which combines genetic characteristics with known risk factors, produced better performance and net benefits in calibration and decision curve analysis. Similar results were validated in three separate GEO cohorts. All of these results showed that the model can be used as a prognostic classifier for clinical decision-making, individual prediction and treatment, as well as follow-up.

Role of galectin 3 binding protein in cancer progression: a potential novel therapeutic target

The lectin galactoside-binding soluble 3 binding protein (LGALS3BP) is a secreted, hyperglycosylated protein expressed by the majority of human cells. It was first identified as cancer and metastasis associated protein, while its role in innate immune response upon viral infection remains still to be clarified. Since its discovery dated in early 90 s, a large body of literature has been accumulating highlighting both a prognostic and functional role for LGALS3BP in cancer. Moreover, data from our group and other have strongly suggested that this protein is enriched in cancer-associated extracellular vesicles and may be considered a promising candidate for a targeted therapy in LGALS3BP positive cancers. Here, we extensively reviewed the literature relative to LGALS3BP role in cancer and its potential value as a therapeutic target.

LGALS3BP: A Potential Plasma Biomarker Associated with Diagnosis and Prognosis in Patients with Sepsis

Purpose

This study aimed to screen differentially expressed proteins (DEPs) in plasma of patients with sepsis through data-independent acquisition (DIA) and enzyme-linked immunosorbent assays (ELISAs), and provide convenient and accurate serum markers for determining the condition of septic patients.

Methods

A total of 53 septic patients and 16 normal controls who were admitted to the Affiliated Hospital of Southwest Medical University between January 2019 and December 2020 were enrolled in this study; 6 specimens from the normal group and 15 from the sepsis group were randomly selected for DIA-based quantitative proteomic analysis. The acquired data were subjected to Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis, and a protein-protein interaction (PPI) network was constructed to screen potential markers. The selected proteins were further verified through ELISAs. The differences between control and sepsis groups and between survivors and non-survivors were analysed. Receiver operating characteristic (ROC) curves were drawn to explore their diagnostic value and prognostic efficacy.

Results

A total of 149 DEPs were identified by bioinformatics methods. The analyses showed that these proteins are mainly involved in biological processes such as cell movement, stress response, cell proliferation, and immune response. Functional pathway analysis showed that they are mainly involved in leukocyte transendothelial migration, protein synthesis and processing, and various bacterial infections. LGALS3BP was selected as a potential plasma biomarker and further verified through an ELISA. Its level in septic patients was significantly higher than that in normal controls, and its level in non-survivors was also higher than that in survivors. The ROC curves suggested its great diagnostic efficacy and prognostic ability in sepsis.

Conclusion

LGALS3BP levels were significantly different between the normal and sepsis groups; it has good diagnostic value in sepsis, and is related to patient prognosis; thus, it might be a biomarker for sepsis.

Lgals3bp suppresses colon inflammation and tumorigenesis through the downregulation of TAK1-NF-κB signaling

Galectin 3-binding protein (LGALS3BP, also known as 90K) is a multifunctional glycoprotein involved in immunity and cancer. However, its precise role in colon inflammation and tumorigenesis remains unclear. Here, we showed that Lgals3bp-/- mice were highly susceptible to colitis and colon tumorigenesis, accompanied by the induction of inflammatory responses. In acute colitis, NF-κB was highly activated in the colon of Lgals3bp-/- mice, leading to the excessive production of pro-inflammatory cytokines, such as IL-6, TNFα, and IL-1β. Mechanistically, Lgals3bp suppressed NF-κB through the downregulation of TAK1 in colon epithelial cells. There was no significant difference in the pro-inflammatory cytokine levels between wild-type and Lgals3bp-/- mice in a chronic inflammatory state, during colon tumorigenesis. Instead, Lgals3bp-/- mice showed elevated levels of GM-CSF, compared to those in WT mice. We also found that GM-CSF promoted the accumulation of myeloid-derived suppressor cells and ultimately increased colon tumorigenesis in Lgals3bp-/- mice. Taken together, Lgals3bp plays a critical role in the suppression of colitis and colon tumorigenesis through the downregulation of the TAK1-NF-κB-cytokine axis. These findings suggest that LGALS3BP is a novel immunotherapeutic target for colon inflammation and tumorigenesis.

Loss of 9p21 Regulatory Hub Promotes Kidney Cancer Progression by Upregulating HOXB13

Loss of chromosome 9p21 is observed in one-thirds of clear-cell renal cell carcinoma (ccRCC) and is associated with poorer patient survival. Unexpectedly, 9p21 LOH does not lead to decreased expression of the 9p21 tumor suppressor genes, CDKN2A and CDKN2B, suggesting alternative mechanisms of 9p-mediated tumorigenesis. Concordantly, CRISPR-mediated 9p21 deletion promotes growth of immortalized human embryonic kidney epithelial cells independently of the CDKN2A/B pathway inactivation. The 9p21 locus has a highly accessible chromatin structure, suggesting that 9p21 loss might contribute to kidney cancer progression by dysregulating genes distal to the 9p21 locus. We identified several 9p21 regulatory hubs by assessing which of the 9p21-interacting genes are dysregulated in 9p21-deleted kidney cells and ccRCCs. By focusing on the analysis of the homeobox gene 13 (HOXB13) locus, we found that 9p21 loss relieves the HOXB13 locus, decreasing HOXB13 methylation and promoting its expression. Upregulation of HOXB13 facilitates cell growth and is associated with poorer survival of patients with ccRCC. IMPLICATIONS: The results of our study propose a novel tumor suppressive mechanism on the basis of coordinated expression of physically associated genes, providing a better understanding of the role of chromosomal deletions in cancer.

Targeting Vesicular LGALS3BP by an Antibody-Drug Conjugate as Novel Therapeutic Strategy for Neuroblastoma

Simple Summary

Antibody Drug Conjugates are an emerging class of biopharmaceuticals that have seen an impressive increase of attention in the field of cancer therapy. Here, we describe the therapeutic activity of 1959-sss/DM3, a non-internalizing ADC targeting LGALS3BP, a secreted, extracellular vesicles-associated protein expressed by the majority of human cancers, including neuroblastoma. We show that 1959-sss/DM3 treatment can cure mice with established neuroblastoma tumours in pseudometastatic, orthotopic and Patient Derived Xenograft models.

Abstract

Neuroblastoma is the most common extra-cranial solid tumor in infants and children, which accounts for approximately 15% of all cancer-related deaths in the pediatric population. New therapeutic modalities are urgently needed. Antibody-Drug Conjugates (ADC)s-based therapy has been proposed as potential strategy to treat this pediatric malignancy. LGALS3BP is a highly glycosylated protein involved in tumor growth and progression. Studies have shown that LGALS3BP is enriched in extracellular vesicles (EV)s derived by most neuroblastoma cells, where it plays a critical role in preparing a favorable tumor microenvironment (TME) through direct cross talk between cancer and stroma cells. Here, we describe the development of a non-internalizing LGALS3BP ADC, named 1959-sss/DM3, which selectively targets LGALS3BP expressing neuroblastoma. 1959-sss/DM3 mediated potent therapeutic activity in different types of neuroblastoma models. Notably, we found that treatments were well tolerated at efficacious doses that were fully curative. These results offer preclinical proof-of-concept for an ADC targeting exosomal LGALS3BP approach for neuroblastomas.

Surfaceome of Exosomes Secreted from the Colorectal Cancer Cell Line SW480: Peripheral and Integral Membrane Proteins Analyzed by Proteolysis and TX114

Exosomes are important bidirectional cell-cell communicators in normal and pathological physiology. Although exosomal surface membrane proteins (surfaceome) enable target cell recognition and are an attractive source of disease marker, they are poorly understood. Here, a comprehensive surfaceome analysis of exosomes secreted by the colorectal cancer cell line SW480 is described. Sodium carbonate extraction/Triton X-114 phase separation and mild proteolysis (proteinase K, PK) of intact exosomes is used in combination with label-free quantitative mass spectrometry to identify 1025 exosomal proteins of which 208 are predicted to be integral membrane proteins (IMPs) according to TOPCONS and GRAVY scores. Interrogation of UniProt database-annotated proteins reveals 124 predicted peripherally-associated membrane proteins (PMPs). Surprisingly, 108 RNA-binding proteins (RBPs)/RNA nucleoproteins (RNPs) are found in the carbonate/Triton X-114 insoluble fraction. Mild PK treatment of SW480-GFP labeled exosomes reveal 58 proteolytically cleaved IMPs and 14 exoplasmic PMPs (e.g., CLU/GANAB/LGALS3BP). Interestingly, 18 RBPs/RNPs (e.g., EIF3L/RPL6) appear bound to the outer exosome surface since they are sensitive to PK proteolysis. The finding that outer surface-localized miRNA Let-7a-5p is RNase A-resistant, but degraded by a combination of RNase A/PK treatment suggests exosomal miRNA species also reside on the outer surface of exosomes bound to RBPs/RNPs.

A Targeted Mass Spectrometry Strategy for Developing Proteomic Biomarkers: A Case Study of Epithelial Ovarian Cancer

Protein biomarkers for epithelial ovarian cancer are critical for the early detection of the cancer to improve patient prognosis and for the clinical management of the disease to monitor treatment response and to detect recurrences. Unfortunately, the discovery of protein biomarkers is hampered by the limited availability of reliable and sensitive assays needed for the reproducible quantification of proteins in complex biological matrices such as blood plasma. In recent years, targeted mass spectrometry, exemplified by selected reaction monitoring (SRM) has emerged as a method, capable of overcoming this limitation. Here, we present a comprehensive SRM-based strategy for developing plasma-based protein biomarkers for epithelial ovarian cancer and illustrate how the SRM platform, when combined with rigorous experimental design and statistical analysis, can result in detection of predictive analytes.Our biomarker development strategy first involved a discovery-driven proteomic effort to derive potential N-glycoprotein biomarker candidates for plasma-based detection of human ovarian cancer from a genetically engineered mouse model of endometrioid ovarian cancer, which accurately recapitulates the human disease. Next, 65 candidate markers selected from proteins of different abundance in the discovery dataset were reproducibly quantified with SRM assays across a large cohort of over 200 plasma samples from ovarian cancer patients and healthy controls. Finally, these measurements were used to derive a 5-protein signature for distinguishing individuals with epithelial ovarian cancer from healthy controls. The sensitivity of the candidate biomarker signature in combination with CA125 ELISA-based measurements currently used in clinic, exceeded that of CA125 ELISA-based measurements alone. The SRM-based strategy in this study is broadly applicable. It can be used in any study that requires accurate and reproducible quantification of selected proteins in a high-throughput and multiplexed fashion.

Increased LGALS3BP promotes proliferation and migration of oral squamous cell carcinoma via PI3K/AKT pathway

Previous studies showed that lectin galactoside-binding soluble 3 binding protein (LGALS3BP) is an important participant in tumor progression. However, its prognostic value and functional mechanism in oral squamous cell carcinoma (OSCC) are still unclear. In this study, we analyzed LGALS3BP expression in OSCC tissues via Oncomine databases and immunohistochemical staining. LGALS3BP was significantly up-regulated in OSCC tumor tissues. IHC analysis showed that LGALS3BP was predominantly expressed in tumor cells and correlated with poor clinical characteristics. In addition, high LGALS3BP expression predicted poor clinical outcomes and multivariate analysis revealed that LGALS3BP expression was as an independent prognostic factor for OS, DFS and RFS (p < .0001, p = .002, p = .002). Mechanically, LGALS3BP regulated OSCC proliferation and migration via PI3K/AKT pathways, which was abrogated by PI3K inhibitor LY294002 in a dose-dependent manner. Our results suggested that LGALS3BP could be served as a novel independent prognostic factor as well as a potential therapeutic target for OSCC treatment.

Prognostic biomarkers for immunotherapy with ipilimumab in metastatic melanoma

New therapies, including the anti‐cytotoxic T lymphocyte antigen (CTLA)‐4 antibody, ipilimumab, is approved for metastatic melanoma. Prognostic biomarkers need to be identified, because the treatment has serious side effects. Serum samples were obtained before and during treatment from 56 patients with metastatic or unresectable malignant melanoma, receiving treatment with ipilimumab in a national Phase IV study (NCT0268196). Expression of a panel of 17 inflammatory‐related markers reflecting different pathways including extracellular matrix remodeling and fibrosis, vascular inflammation and monocyte/macrophage activation were measured at baseline and the second and/or third course of treatment with ipilimumab. Six candidate proteins [endostatin, osteoprotegerin (OPG), C‐reactive protein (CRP), pulmonary and activation‐regulated chemokine (PARC), growth differentiation factor 15 (GDF15) and galectin‐3 binding‐protein (Gal3BP)] were persistently higher in non‐survivors. In particular, high Gal3BP and endostatin levels were also independently associated with poor 2‐year survival after adjusting for lactate dehydrogenase, M‐stage and number of organs affected. A 1 standard deviation increase in endostatin gave 1·74 times [95% confidence interval (CI) = 1·10–2·78, P = 0·019] and for Gal3BP 1·52 times (95% CI = 1·01–2·29, P = 0·047) higher risk of death in the adjusted model. Endostatin and Gal3BP may represent prognostic biomarkers for patients on ipilimumab treatment in metastatic melanoma and should be further evaluated. Owing to the non‐placebo design, we could only relate our findings to prognosis during ipilimumab treatment.

Proteomic Characterization of Epithelial-Like Extracellular Vesicles in Advanced Endometrial Cancer

Endometrial cancer (EC) is the most frequent gynecological cancer. Tumor dissemination affecting ∼20% of EC patients is characterized at the primary carcinoma by epithelial-to-mesenchymal transition (EMT) associated with myometrial infiltration. At distant sites, the interaction of circulating tumor cells (CTCs) with the microenvironment is crucial for metastatic colonization, with a participation of the extracellular vesicles (EVs). We comprehensively approached these primary and secondary sites to study the impact of tumor EVs on the metastatic efficiency of CTCs in EC. Tumor EVs in circulation reproduce the epithelial phenotype predominant in the primary carcinoma, whereas CTCs are characterized by an EMT phenotype. We modeled this EMT-related clinical scenario in the Hec1A endometrial cell line and characterized the epithelial-like EVs in circulation by SILAC proteome analysis. The identification of proteins involved in cell-cell and cell-matrix interaction and binding, together with in vitro evidence of an improved adhesion of CTC to a functionalized endothelium, suggests a contribution of the epithelial-like EVs in the homing of CTCs at metastatic sites. Accordingly, adhesion protein LGALS3BP was found to be significantly enriched in circulating EVs from a cohort of EC patients with a high risk of recurrence by targeted proteomics (multiple reaction monitoring), highlighting its potential in liquid biopsy in EC.

Galectin-3-binding protein: A multitask glycoprotein with innate immunity functions in viral and bacterial infections

Galectin-3-binding protein (Gal-3BP) is a ubiquitous and multifunctional secreted glycoprotein originally identified and mainly studied in the context of neoplastic transformation and cancer progression. However, Gal-3BP expression is induced in viral infection and by a multitude of molecules that either mimic or are characteristic for an ongoing inflammation and microbial infection, such as IFN-α, IFN-β, IFN-γ, TNF-α, poly(I:C), dsRNA, and dsDNA. Furthermore, Gal-3BP belongs to the scavenger receptor cysteine-rich (SRCR) domain-containing protein family, by virtue of its N-terminal SRCR domain. The SRCR domain is found in soluble or membrane-associated innate immunity-related proteins and is implicated in self-nonself discrimination. This review summarizes the current knowledge of structural features of Gal-3BP and its proposed intracellular and extracellular innate immunity functions with special emphasis on viral and bacterial infections.

Comparative two-dimensional polyacrylamide gel electrophoresis (2D-PAGE) of human milk to identify dysregulated proteins in breast cancer

Breast cancer (BC) remains a major cause of mortality, and early detection is considered important for reducing BC-associated deaths. Early detection of BC is challenging in young women, due to the limitations of mammography on the dense breast tissue of young women. We recently reported results of a pilot proteomics study, using one-dimensional polyacrylamide gel electrophoresis (1D-PAGE) and mass spectrometry (MS) to investigate differences in milk proteins from women with and without BC. Here, we applied two-dimensional polyacrylamide gel electrophoresis (2D-PAGE) and MS to compare the protein pattern in milk from the breasts of a single woman who was diagnosed with BC in one breast 24 months after donating her milk. Statistically different gel spots were picked for protein digestion followed by nanoliquid chromatography tandem MS (nanoLC-MS/MS) analysis. The upregulated proteins in BC versus control are alpha-amylase, gelsolin isoform a precursor, alpha-2-glycoprotein 1 zinc isoform CRA_b partial, apoptosis-inducing factor 2 and vitronectin. Several proteins were downregulated in the milk of the breast later diagnosed with cancer as compared to the milk from the healthy breast, including different isoforms of albumin, cholesterol esterase, different isoforms of lactoferrin, different proteins from the casein family and different isoforms of lysozyme. Results warrant further studies to determine the usefulness of these milk proteins for assessing risk and detecting occult disease. MS data is available via ProteomeXchange with identifier PXD009860.

Glycoprotein 90K Promotes E-Cadherin Degradation in a Cell Density-Dependent Manner via Dissociation of E-Cadherin-p120-Catenin Complex

Glycoprotein 90K (also known as LGALS3BP or Mac-2BP) is a tumor-associated protein, and high 90K levels are associated with poor prognosis in some cancers. To clarify the role of 90K as an indicator for poor prognosis and metastasis in epithelial cancers, the present study investigated the effect of 90K on an adherens junctional protein, E-cadherin, which is frequently absent or downregulated in human epithelial cancers. Treatment of certain cancer cells with 90K significantly reduced E-cadherin levels in a cell-population-dependent manner, and these cells showed decreases in cell adhesion and increases in invasive cell motility. Mechanistically, 90K-induced E-cadherin downregulation occurred via ubiquitination-mediated proteasomal degradation. 90K interacted with the E-cadherin–p120-catenin complex and induced its dissociation, altering the phosphorylation status of p120-catenin, whereas it did not associate with β-catenin. In subconfluent cells, 90K decreased membrane-localized p120-catenin and the membrane fraction of the p120-catenin. Particularly, 90K-induced E-cadherin downregulation was diminished in p120-catenin knocked-down cells. Taken together, 90K upregulation promotes the dissociation of the E-cadherin–p120-catenin complex, leading to E-cadherin proteasomal degradation, and thereby destabilizing adherens junctions in less confluent tumor cells. Our results provide a potential mechanism to explain the poor prognosis of cancer patients with high serum 90K levels.

Serum quantitative proteomic analysis of patients with keshan disease based on iTRAQ labeling technique: A first term study

Keshan disease (KD), an endemic myocardiopathy, with unknown etiology, is still threatening human health. Proteomics studies of Keshan disease is rarely known. In the current study, isobaric tags for relative and absolute quantitation (iTRAQ) labeling coupled with two-dimensional liquid chromatography-tandem mass spectrometry (2D-LC-MS/MS) was firstly used to screen for the differentially expressed proteins (DEPs) in serum between Keshan disease and healthy residents in endemic area. 27 differentially expressed proteins were quantified, 9 of which were significantly altered (fold change > 1.2 or < 0.8) between the two groups. Bioinformatic analysis revealed that a wide variety of biology process played roles in KD pathophysiology. These differentially expressed proteins were mainly involved in complement coagulation pathways. A significant high serum level of LGALS3BP were observed. Our first term study in KD proteomics provided new view into the molecular mechanisms of KD disease.

Molecular correlates and prognostic value of tmTNF-α expression in colorectal cancer of 5-Fluorouracil-Based Adjuvant Therapy

Transmembrane tumor necrosis factor-α (tmTNF-α) is known to induce the activation of NF-κB to protect tumor cells. Upregulation of tmTNF-α leads to resistance to apoptosis and induces drug resistance in breast cancer. However, the expression of tmTNF-α in colorectal cancer (CRC) and its association with clinical outcome in CRC have remained unclear. In this study, we examined the tmTNF-α expression in CRC by immunohistochemistry and western blotting, assessed the prognostic value of tmTNF-α related to the recurrence/metastasis and survival of stage II/III CRC by the Kaplan-Meier survival curve and Cox regression model, and also explored the role of tmTNF-α expression on the chemotherapeutic efficacy of 5-Fluorouracil by flow cytometry assay and cell counting kit-8 (CCK-8) in vitro. Overall, we found that 77 (78.6%) out of 98 patients exhibited higher tmTNF-α expression in the CRC tissues comparing with the adjacent tissues. The tmTNF-α expression was correlated with Differentiation (P = 0.019), TNM stage (P = 0.039), Lymph nodes metastasis (P = 0.024) and Lymphovascular invasion (P = 0.027) but not related with Age (P = 0.617), Gender (P = 0.625), Tumor location (P = 0.138), Perforation/Obstruction (P = 1.000), Depth of invasion (P = 0.327), and microsatellite instability status (P = 0.150). The prognostic analyses showed that high tmTNF-α expression patients was significantly associated with decreased Disease-Free Survival (P = 0.0209) and Overall Survival (P = 0.0163). CCK-8 results suggested that the tmTNF-α influenced the chemotherapeutic effect of 5-Fluorouracil on colon cancer cells. Altogether, these data indicated the stageII/III CRC patients with high tmTNF-α expression were more likely to have a worse prognosis than patients with low tmTNF-α expression and tmTNF-α may influence the chemotherapeutic effect of 5-Fluorouracil. The mechanism for these observations warrants further study.

Role of the extracellular matrix-located Mac-2 binding protein as an interactor of the Wnt proteins

The Wnt proteins constitute a conserved family of secreted palmitoleate-containing signaling proteins that play important roles in development and tissue homeostasis. Their hydrophobic nature has raised the question of how the proteins are transported outside the cells. Accumulating evidence suggests that several different mechanisms, including transport by lipoprotein particles and exosomes, may contribute to this process. Here, we expressed epitope-tagged Wnt4 in HEK293 cells, and identified Mac-2 binding protein (Mac-2BP) as its binding partner in the serum-free conditioned medium. Serine-to-alanine substitution at the conserved fatty acid-conjugation site did not affect Mac-2BP binding. Subsequent studies showed that Mac-2BP may be a general Wnt interactor. It is found in the extracellular matrix (ECM) of various tissues, where it forms unusual oligomeric ring-like structures. Its functions appear to include interactions with cells and certain ECM components. Intriguingly, both Wnt signaling and Mac-2BP expression are upregulated in many types of cancer. Our studies on the four-domain Mac-2BP indicate a crucial role in Wnt binding for the C-terminal domain that bears no sequence similarity to any other protein. Mac-2BP may have a role in regulating the extracellular spreading and storage of the Wnts, thereby modulating their bioavailability and stability.

A Proteomic Analysis of the Malignant Mesothelioma Secretome Using iTRAQ

Backgound/Aim: Malignant mesothelioma (MM) is an aggressive and fatal pleural cancer. The cell secretome offers information allowing insight into the pathogenesis of MM while offering the possibility to identify potential therapeutic targets and biomarkers. In the present study the secretome protein profile of MM cell lines was compared to normal mesothelial cells.

MATERIALS AND METHODS

Six MM cell lines were compared against three primary mesothelial cell culture preparations using iTRAQ® mass spectrometry.

RESULTS

MM cell lines more abundantly secreted exosome-associated proteins than mesothelial cells. MM cell secretomes were enriched in proteins that are involved in response to stress, carbon metabolism, biosynthesis of amino acids, antigen processing and presentation and protein processing in the endoplasmic reticulum.

CONCLUSION

The MM cell secretome is enriched in proteins that are likely to enhance its growth and response to stress and help it inhibit an adaptive immune response. These are potential targets for therapeutic and biomarker discovery.

The function of Shoc2: A scaffold and beyond

The extracellular signal-regulated kinase (ERK1/2) cascade regulates a myriad of functions in multicellular organisms. Scaffold proteins provide critical spatial and temporal control over the specificity of signaling. Shoc2 is a scaffold that accelerates activity of the ERK1/2 pathway. Loss of Shoc2 expression in mice results in embryonic lethality, thus highlighting the essential role of Shoc2 in embryogenesis. In agreement, patients carrying mutated Shoc2 suffer from a wide spectrum of developmental deficiencies. Efforts to understand the mechanisms by which Shoc2 controls ERK1/2 activity revealed the intricate machinery that governs the ability of Shoc2 to transduce signals of the ERK1/2 pathway. Understanding the mechanisms by which Shoc2 contributes to a high degree of specificity of ERK1/2 signaling as well as deciphering the biological functions of Shoc2 in development and human disorders are major unresolved questions.

Shoc2-tranduced ERK1/2 motility signals--Novel insights from functional genomics

The extracellular signal-regulated kinase 1 and 2 (ERK1/2) pathway plays a central role in defining various cellular fates. Scaffold proteins modulating ERK1/2 activity control growth factor signals transduced by the pathway. Here, we analyzed signals transduced by Shoc2, a critical positive modulator of ERK1/2 activity. We found that loss of Shoc2 results in impaired cell motility and delays cell attachment. As ERKs control cellular fates by stimulating transcriptional response, we hypothesized that the mechanisms underlying changes in cell adhesion could be revealed by assessing the changes in transcription of Shoc2-depleted cells. Using quantitative RNA-seq analysis, we identified 853 differentially expressed transcripts. Characterization of the differentially expressed genes showed that Shoc2 regulates the pathway at several levels, including expression of genes controlling cell motility, adhesion, crosstalk with the transforming growth factor beta (TGFβ) pathway, and expression of transcription factors. To understand the mechanisms underlying delayed attachment of cells depleted of Shoc2, changes in expression of the protein of extracellular matrix (lectin galactoside-binding soluble 3-binding protein; LGALS3BP) were functionally analyzed. We demonstrated that delayed adhesion of the Shoc2-depleted cells is a result of attenuated expression and secretion of LGALS3BP. Together our results suggest that Shoc2 regulates cell motility by modulating ERK1/2 signals to cell adhesion.