Antigen Family Research Articles

CT45A1-mediated MLC2 (MYL9) phosphorylation promotes natural killer cell resistance and outer cell fate in a cell-in-cell structure, potentiating the progression of microsatellite instability-high colorectal cancer.

Patients with microsatellite instability-high (MSI-H) colorectal cancer (CRC) have high tumor mutation burden and tumor immunogenicity, exhibiting a higher response rate to immunotherapy and better survival. However, a portion of MSI-H CRC patients still experience adverse disease outcomes. We aimed to identify the tumor-autonomous regulators determining these heterogeneous clinical outcomes. The Cancer Genome Atlas (TCGA) dataset was used to identify regulators in MSI-H CRC patients with unfavorable outcomes. Stable CRC tumor clones expressing targeted regulators were established to evaluate migratory and stemness properties, immune cell vulnerability, and cell-in-cell (CIC) structure formation. RNA-sequencing (RNA-seq) was used to identify enriched biological pathways in stable CRC tumor clones. Clinicopathological characterization of formalin-fixed paraffin-embedded (FFPE) MSI-H CRC specimens was performed to explore the underlying mechanisms involved. We showed that cancer/testis antigen family 45 member A1 (CT45A1) expression was upregulated in MSI-H CRC patients with poor survival outcomes. CT45A1-expressing microsatellite stable (MSS) CRC cells showed enhanced migratory ability. However, CT45A1-expressing MSI-H CRC cells, but not MSS CRC cells, showed higher resistance to natural killer (NK) cell cytotoxicity and served as outer cells in homotypic CIC structures, preventing exogenous or therapeutic antibody access to inner CRCcells. Inactivating RHO-ROCK/MLCK-MLC2 signaling with small-molecule inhibitors or short-hairpin RNAs (shRNAs) targeting myosin light chain kinase (MYLK) abolished NK cell resistance and reduced the outer cell fate of CT45A1-expressing MSI-H CRC cells. In MSI-H CRC patients, CT45A1-positive tumors exhibited increased MLC2 phosphorylation, increased outer cell fate, and decreased survival. We demonstrated that CT45A1 potentiates the advanced progression of MSI-H CRC, and targeting MLC2 phosphorylation may enhance immunotherapy efficacy in CT45A1-positive MSI-H CRC patients.

Application of optical tweezer technology reveals that PfEBA and PfRH ligands, not PfMSP1, play a central role in Plasmodium falciparum merozoite-erythrocyte attachment.

Malaria pathogenesis and parasite multiplication depend on the ability of Plasmodium merozoites to invade human erythrocytes. Invasion is a complex multi-step process involving multiple parasite proteins which can differ between species and has been most extensively studied in P. falciparum. However, dissecting the precise role of individual proteins has to date been limited by the availability of quantifiable phenotypic assays. In this study, we apply a new approach to assigning function to invasion proteins by using optical tweezers to directly manipulate recently egressed P. falciparum merozoites and erythrocytes and quantify the strength of attachment between them, as well as the frequency with which such attachments occur. Using a range of inhibitors, antibodies, and genetically modified strains including some generated specifically for this work, we quantitated the contribution of individual P. falciparum proteins to these merozoite-erythrocyte attachment interactions. Conditional deletion of the major P. falciparum merozoite surface protein PfMSP1, long thought to play a central role in initial attachment, had no impact on the force needed to pull merozoites and erythrocytes apart, whereas interventions that disrupted the function of several members of the EBA-175 like Antigen (PfEBA) family and Reticulocyte Binding Protein Homologue (PfRH) invasion ligand families did have a significant negative impact on attachment. Deletion of individual PfEBA and PfRH ligands reinforced the known redundancy within these families, with the deletion of some ligands impacting detachment force while others did not. By comparing over 4000 individual merozoite-erythrocyte interactions in a range of conditions and strains, we establish that the PfEBA/PfRH families play a central role in P. falciparum merozoite attachment, not the major merozoite surface protein PfMSP1.

Investigating the Role of Differentially Expressed Genes and Sex-Specific Genes in Lung Adenocarcinoma: A Transcriptomic Analysis

Lung cancer is a life-threatening disease that affects hundreds of thousands of patients every year. While conventional medicine offers effective treatments for lung cancer, the use of targeted therapy can offer patients a more favorable treatment by being as effective and by minimizing the side effects the patient experiences. The purpose of this research is to identify any differentially expressed or sex-specific genes in lung adenocarcinoma (LUAD) that can act as potential targets for treatment. Using transcriptomic profiles of LUAD tissues from The Cancer Genome Atlas, these profiles are analyzed using the TCGABiolinks library on R. The differentially expressed genes are then used to generate gene ontology, create protein association networks, and identify survival plots of genes using Metascape, STRING, and the Human Protein Atlas respectively. Similar procedures were used for the sex-specific analysis. The gene ontology analysis showed that the TFAP2 family of transcription factors and the PID HNF3B pathway likely promote tumorigenesis in LUAD. Moreover, AGER and SFTPC, genes involved in lung development, were underexpressed in all LUAD samples. Patients with a higher expression of these genes had a higher survival rate than others and can act as potential prognostic markers. In sex-specific genes, it was found that members of the MAGE-A family, a testis antigen family, were highly up-regulated in both males and females. The dysregulation of these genes in females might have a specific role in LUAD progression. These findings can be investigated further to develop better therapies to treat the disease.

Mutational signatures and their association with cancer survival and gene expression in multiple cancer types.

Different endogenous and exogenous mutational processes cause specific patterns of somatic mutations and mutational signatures. Although their biological research has been intensive, there are only rare studies assessing the possible prognostic role of mutational signatures. We used data from The Cancer Genome Atlas to study the associations between the activity of the mutational signatures and four survival endpoints in 18 types of malignancies. We further explored the prognostic differences according to, for example, the HPV status in head and neck squamous cell carcinomas and smoking status in lung cancers. The predictive power of the signatures over time was evaluated with a dynamic area under the curve model, and the links between mutational signature activities and differences in gene expression patterns were analyzed. In 12 of 18 studied cancer types, we identified at least one mutational signature whose activity predicted survival outcomes after adjusting for the established prognostic factors. For example, overall survival was associated with the activity of mutational signatures in nine cancer types and disease-specific survival in seven cancer types. The clock-like signatures SBS5 and SBS40 were most commonly associated with survival endpoints. The genes of the myosin binding protein and melanoma antigen families were among the most substantially dysregulated genes between the signatures of low and high activity. The differences in gene expression also revealed various enriched pathways. Based on these data, specific mutational signatures associate with the gene expression and have the potential to serve as strong prognostic factors in several cancer types.

Development of Ligands and Degraders Targeting MAGE-A3.

Type I melanoma antigen (MAGE) family members are detected in numerous tumor types, and expression is correlated with poor prognosis, high tumor grade, and increased metastasis. Type I MAGE proteins are typically restricted to reproductive tissues, but expression can recur during tumorigenesis. Several biochemical functions have been elucidated for them, and notably, MAGEs regulate proteostasis by serving as substrate recognition modules for E3 ligase complexes. The repertoire of E3 ligase complexes that can be hijacked for targeted protein degradation continues to expand, and MAGE-E3 complexes are an especially attractive platform given their cancer-selective expression. Additionally, type I MAGE-derived peptides are presented on cancer cell surfaces, so targeted MAGE degradation may increase antigen presentation and improve immunotherapy outcomes. Motivated by these applications, we developed novel, small-molecule ligands for MAGE-A3, a type I MAGE that is widely expressed in tumors and associates with TRIM28, a RING E3 ligase. Chemical matter was identified through DNA-encoded library (DEL) screening, and hit compounds were validated for in vitro binding to MAGE-A3. We obtained a cocrystal structure with a DEL analog and hypothesize that the small molecule binds at a dimer interface. We utilized this ligand to develop PROTAC molecules that induce MAGE-A3 degradation through VHL recruitment and inhibit the proliferation of MAGE-A3 positive cell lines. These ligands and degraders may serve as valuable probes for investigating MAGE-A3 biology and as foundations for the ongoing development of tumor-specific PROTACs.

The role of SEMG1 overexpression in OSCC tumorigenesis and its relation with metabolic molecules.

This study aimed to investigate the expression and biological significance of Semenogelin 1 (SEMG1), a member of the cancer-testis antigen family, in oral squamous cell carcinoma (OSCC). Further, we explored its potential association with metabolism-related molecules. SEMG1 expression levels in OSCC were determined through immunohistochemistry, flow cytometry, and Western blot analyses. To decipher the biological implications of SEMG1 in OSCC, the CAL27 OSCC cell line was either stably overexpressed with SEMG1 or subjected to SEMG1-shRNA knockdown. The relationship between clinicopathological parameters and SEMG1 expression in OSCC patients was also assessed. SEMG1 was found to be overexpressed in OSCC, though its expression was not influenced by the pathological grade. The fluorescent dihydroethidium assay indicated that SEMG1 augmented reactive oxygen species production. The mitochondrial membrane potential assay suggested a significant upregulation of mitochondrial membrane potential by SEMG1. Cell cycle assessments highlighted that SEMG1 overexpression led to a notable rise in cells entering the S-phase. Additionally, a strong correlation between SEMG1 expression and both ENO1 and PKM2 expression in OSCC was observed. The findings underscore the elevated expression of SEMG1 in OSCC and its contributory role in the tumorigenesis of OSCC patients.

Treatment and management of coenurosis by Taenia multiceps: field data from outbreaks in endemic regions and literature review

BackgroundTaenia multiceps coenurosis is endemic in sheep from various regions worldwide. Dogs, the key hosts, shed T. multiceps eggs in their feces contaminating the pasture, and lambs are mostly infected during their first turnout into pastures. The disease is manifested in two forms: acute (due to the migrating oncospheres in the CNS) or chronic (due to the developing coenuri in the brain or spinal cord). Both forms are frequently accompanied by neurological symptoms.MethodsField trials conducted in an endemic region (Sardinia, Italy) to treat replacement lambs in six sheep flocks infected with acute coenurosis are summarized in this article. The article also reviews earlier reports on various approaches developed to treat and immunize sheep against coenurosis.ResultsAccurate detection of the time in which lambs become infected is crucial in deciding which treatment approach should be used. Acute disease can be successfully treated via chemotherapy. Results of field trials conducted in Sardinia revealed the efficacy of three (1-week apart) oxfendazole doses (14.15 mg/kg) in protecting apparently healthy lambs in the infected flocks from developing neurological symptoms. A single praziquantel dose (18.75 mg/kg) worked well for the same purpose and was also found significant in treating 5 of 16 clinically ill lambs in one flock. Earlier reports documented high rates of recovery (up to 100%) in clinically diseased lambs that received much higher doses (50–100 mg/kg) of praziquantel. However, chemotherapy is not preferred in chronic coenurosis since it can lead to rupture of the coenuri, giving rise to serious inflammation in the CNS. Surgical intervention is highly recommended in this case, and the pooled success rates for surgery in chronic-infected cases was estimated at 82.1% (95% CI 73.1–91.0%). However, various trials have been conducted to immunize sheep against T. multiceps coenurosis, and the 18k (Tm18) family of oncosphere antigens was found promising as a vaccine candidate.ConclusionsIn acute coenurosis, selection of the proper anthelmintic should be done after consulting the owner for several reasons: (1) costs of the used anthelmintic: treating a small flock of 100 sheep costs around 1170 and 660 € for praziquantel and oxfendazole, respectively; (2) withdrawal time of the used anthelmintic: No time is required before consuming meat and milk from praziquantel-treated sheep, whereas meat and milk from oxfendazole-treated sheep should not be consumed for 44 and 9 days, respectively, causing additional costs for the farmers. Since no commercial vaccines have yet been developed against T. multiceps coenurosis in sheep, preventive measures remain the cornerstone of controlling this serious disease.Graphical

An Immunohistochemical Study of MAGE Proteins in Hepatocellular Carcinoma.

Hepatocellular carcinoma (HCC) is one the most common primary malignancies with high mortality and morbidity. The melanoma-associated antigen (MAGE) gene family includes several genes that are highly expressed in numerous human cancers, making many of them part of the cancer-testis antigen (CTA) family. MAGE-C1 is expressed in various malignancies but is absent in normal cells, except for the male germ line. Its presence is associated with a worse prognosis, increased tumor aggressiveness, and lymph node invasion. Similarly, MAGE-C2 is linked to the development of various malignant tumors. Despite these associations, the roles and mechanisms of MAGE-C1/MAGE-C2 in HCC remain unclear. This study aimed to evaluate the expression of MAGE-C1 and MAGE-C2 in HCC and correlate it with clinicohistological characteristics. Our findings indicated that MAGE-C1 expression is associated with a higher number of nodules, elevated AFP levels, HBV or HCV positivity, older age, male sex, and lymph node invasion. MAGE-C2 expression was correlated with these characteristics and the presence of cirrhosis. These results align with the limited literature, which suggests a correlation between MAGE expression and older age and HBV infection. Consequently, our study suggests that MAGE-C1 and MAGE-C2 are promising novel biomarkers for prognosis and potential therapeutic targets in HCC.

Evolutionary and Expression Analysis of the Pig MAGE Gene Family.

The melanoma-associated antigen (MAGE) family found in eukaryotes plays a crucial role in cell proliferation and differentiation, spermatogenesis, neural development, etc. This study explored the validation and evolution of MAGE genes in eukaryotic genomes and their distribution and expression patterns in pigs. In total, 249 MAGE genes were found on 13 eukaryotic species. In total, 33, 25, and 18 genes were located on human, mouse, and pig genomes, respectively. We found eight, four, and three tandemly duplicated gene clusters on the human, mouse, and pig genomes, respectively. The majority of MAGE genes in mammals are located on the X chromosome. According to the phylogenetic analysis, the MAGE family genes were classified into 11 subfamilies. The NDN gene in zebrafish (DreNDN) was the root of this evolutionary tree. In total, 10 and 11 MAGE genes on human and mouse genomes, respectively, exhibited a collinearity relationship with the MAGE genes on pig genomes. Taking the MAGE family genes in pigs, the MAGE subfamilies had similar gene structures, protein motifs, and biochemical attributes. Using the RNA-seq data of Duroc pigs and Rongchang pigs, we detected that the expression of type I MAGE genes was higher in reproductive tissues, but type II MAGE genes were predominantly expressed in the brain tissue. These findings are a valuable resource for gaining insight into the evolution and expression of the MAGE family genes.

TMErisk score: A tumor microenvironment-based model for predicting prognosis and immunotherapy in patients with head and neck squamous cell carcinoma

Tumor microenvironment (TME) is closely associated with the progression and prognosis of head and neck squamous cell carcinoma (HNSCC). To investigate potential biomarkers for predicting therapeutic outcomes in HNSCC, we analyzed the immune and stromal status of HNSCC based on the genes associated with TME using the ESTIMATE algorithm. Immune and stromal genes were identified with differential gene expression and weighted gene co-expression network analysis (WGCNA). From these genes, 118 were initially selected through Cox univariate regression and then further input into least absolute shrinkage and selection operator (LASSO) regression analysis. As a result, 11 genes were screened out for the TME-related risk (TMErisk) score model which presented promising overall survival predictive potential. The TMErisk score was negatively associated with immune and stromal scores but positively associated with tumor purity. Individuals with high TMErisk scores exhibited decreased expression of most immune checkpoints and all human leukocyte antigen family genes, and reduced abundance of infiltrating immune cells. Divergent genes were mutated in HNSCC. In both high and low TMErisk score groups, the tumor protein P53 exhibited the highest mutation frequency. A higher TMErisk score was found to be associated with reduced overall survival probability and worse outcomes of immunotherapy. Therefore, the TMErisk score could serve as a valuable model for the outcome prediction of HNSCC in clinic.

Construction and analysis of a reliable five-gene prognostic signature for colon adenocarcinoma associated with the wild-type allelic state of the COL6A6 gene.

Tumors emerge by acquiring a number of mutations over time. The first mutation provides a selective growth advantage compared to adjacent epithelial cells, allowing the cell to create a clone that can outgrow the cells that surround it. Subsequent mutations determine the risk of the tumor progressing to metastatic cancer. Some secondary mutations may inhibit the aggressiveness of the tumor while still increasing the survival of the clone. Meaningful mutations in genes may provide a strong molecular foundation for developing novel therapeutic strategies for cancer. The somatic mutation and prognosis in colon adenocarcinoma (COAD) were analyzed. The copy number variation (CNV) and differentially expressed genes (DEGs) between the collagen type VI alpha 6 chain (COL6A6) mutation (COL6A6-MUT) and the COL6A6 wild-type (COL6A6-WT) subgroups were evaluated. The independent prognostic signatures based on COL6A6-allelic state were determined to construct a Cox model. The biological characteristics and the immune microenvironment between the two risk groups were compared. COL6A6 was found to be highly mutated in COAD at a frequency of 9%. Patients with COL6A6-MUT had a good overall survival (OS) compared to those with COL6A6-WT, who had a different CNV pattern. Significant differences in gene expression were established for 593 genes between the COL6A6-MUT and COL6A6-WT samples. Among them, MUC16, ASNSP1, PRR18, PEG10, and RPL26P8 were determined to be independent prognostic factors. The internally validated prognostic risk model, constructed using these five genes, demonstrated its value by revealing a significant difference in patient prognosis between the high-risk and low-risk groups. Specifically, patients in the high-risk group exhibited a considerably worse prognosis than did those in the low-risk group. The high-risk group had a significantly higher proportion of patients over 60 years of age and patients in stage III. Moreover, the tumor immune dysfunction and exclusion (TIDE) score and the expression of human leukocyte antigen (HLA) family genes were all higher in the high-risk group than that in the low-risk group. The allelic state of COL6A6 and the five associated DEGs were identified as novel biomarkers for the diagnosis and prognosis of COAD and may be therapeutic targets in COAD.

Abstract 6845: MAGEA3 expression and secretion in MMR-MSH6 and MMR-PMS2 microsatellite-stable colorectal cancer

Abstract Despite the breakthrough of PD-1/PD-L1 blockade therapy in the recent years, mixed responses have been shown across multiple tumor types, including in colorectal cancer (CRC), the second leading cause of death worldwide. This immunotherapy has proven to be successful for a subtype of CRC that carries mismatch repair deficiency (dMMR) and high microsatellite instability (MSI-H), despite a lack of response by microsatellite-stable CRC. For these types of non-responsive cancers, new immunotherapy targets are currently being investigated for alternative therapy such as the MAGE-A cancer testis antigen family whose expression is restricted to germline cells in normal tissue but is overexpressed in many cancer cells. In this study, we examine the relationship between MAGEA3 and MMR proteins MSH6 and PMS2. Immunohistochemical staining of CRC tissues demonstrated co-expression between MAGEA3 with both MSH6 and PMS2. Immune cells were observed to express MAGEA3 in CRC as well. To investigate the possibility of secreted MAGEA3 from tumor cells, we performed western blot analysis of CRC cell lines, ELISA, and binding assay on cell lines and the positive results suggest that MAGEA3 protein is secreted. The results suggest that MAGE-A3 may be a promising target for microsatellite-stable colorectal cancer immunotherapy. Citation Format: Jina Yom, Rachel Gonzalez, Bailey Gilmore, Zhaoying Guo, Andy Han, Eden Zewdu, Dehe Kong, Tianli Qu, Hailey Guo, Alex Strom, Zoe Zhao, Xiaomin Hu, Qi Ren, Yan Ma, Ranran Zhang, Zhaohui Wu, Xuan Liu, Wei Fu. MAGEA3 expression and secretion in MMR-MSH6 and MMR-PMS2 microsatellite-stable colorectal cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 6845.

Expression of Immunotherapy Target PRAME in Cancer Correlates with Histone H3 Acetylation and Is Unrelated to Expression of Methylating (DMNT3A/3B) and Demethylating (TET1) Enzymes.

Background/Objectives: Preferentially expressed antigen in melanoma (PRAME), a member of the cancer testis antigen family, is a promising target for cancer immunotherapy. Understanding the epigenetic mechanisms involved in the regulation of PRAME expression might be crucial for optimizing anti-PRAME treatments. Methods: Three malignancies of different lineages (sinonasal melanoma, testicular seminoma, and synovial sarcoma), in which immunohistochemical (IHC) reactivity for PRAME is a common yet variable feature, were studied. The expression of PRAME, ten-eleven translocation demethylase 1 (TET1), and DNA methyltransferase (DNMT) 3A and 3B were evaluated using immunohistochemistry. Moreover, the expression of two epigenetic marks, 5-hydroxymethylcytosine (5hmC) and histone 3 acetylation (H3ac), was tested. Results: All PRAME-positive tumors expressed medium-to-high levels of H3ac but differed considerably with respect to other markers. In seminomas, PRAME expression correlated with TET1, but in melanomas and synovial sarcomas, it correlated with both DNMTs and DNMT3A, respectively. Conclusions: PRAME expression was not determined by a balance between the global expression of DNA methylating/demethylating enzymes. However, histone acetylation may be one of the epigenetic mechanisms involved in PRAME regulation. Thus, the therapeutic combination of histone deacetylase inhibitors and PRAME immunotherapy merits further investigation.

Human paraneoplastic antigen Ma2 (PNMA2) forms icosahedral capsids that can be engineered for mRNA delivery

A number of endogenous genes in the human genome encode retroviral gag-like proteins, which were domesticated from ancient retroelements. The paraneoplastic Ma antigen (PNMA) family members encode a gag-like capsid domain, but their ability to assemble as capsids and traffic between cells remains mostly uncharacterized. Here, we systematically investigate human PNMA proteins and find that a number of PNMAs are secreted by human cells. We determine that PNMA2 forms icosahedral capsids efficiently but does not naturally encapsidate nucleic acids. We resolve the cryoelectron microscopy (cryo-EM) structure of PNMA2 and leverage the structure to design engineered PNMA2 (ePNMA2) particles with RNA packaging abilities. Recombinantly purified ePNMA2 proteins package mRNA molecules into icosahedral capsids and can function as delivery vehicles in mammalian cell lines, demonstrating the potential for engineered endogenous capsids as a nucleic acid therapy delivery modality.

Unveiling Gene Regulatory Networks That Characterize Difference of Molecular Interplays Between Gastric Cancer Drug Sensitive and Resistance Cell Lines.

Gastric cancer is a leading cause of cancer-related deaths globally and chemotherapy is widely accepted as the standard treatment for gastric cancer. However, drug resistance in cancer cells poses a significant obstacle to the success of chemotherapy, limiting its effectiveness in treating gastric cancer. Although many studies have been conducted to unravel the mechanisms of acquired drug resistance, the existing studies were based on abnormalities of a single gene, that is, differential gene expression (DGE) analysis. Single gene-based analysis alone is insufficient to comprehensively understand the mechanisms of drug resistance in cancer cells, because the underlying processes of the mechanism involve perturbations of the molecular interactions. To uncover the mechanism of acquired gastric cancer drug resistance, we perform for identification of differentially regulated gene networks between drug-sensitive and drug-resistant cell lines. We develop a computational strategy for identifying phenotype-specific gene networks by extending the existing method, CIdrgn, that quantifies the dissimilarity of gene networks based on comprehensive information of network structure, that is, regulatory effect between genes, structure of edge, and expression levels of genes. To enhance the efficiency of identifying differentially regulated gene networks and improve the biological relevance of our findings, we integrate additional information and incorporate knowledge of network biology, such as hubness of genes and weighted adjacency matrices. The outstanding capabilities of the developed strategy are validated through Monte Carlo simulations. By using our strategy, we uncover gene regulatory networks that specifically capture the molecular interplays distinguishing drug-sensitive and drug-resistant profiles in gastric cancer. The reliability and significance of the identified drug-sensitive and resistance-specific gene networks, as well as their related markers, are verified through literature. Our analysis for differentially regulated gene network identification has the capacity to characterize the drug-sensitive and resistance-specific molecular interplays related to mechanisms of acquired drug resistance that cannot be revealed by analysis based solely on abnormalities of a single gene, for example, DGE analysis. Through our analysis and comprehensive examination of relevant literature, we suggest that targeting the suppressors of the identified drug-resistant markers, such as the Melanoma Antigen (MAGE) family, Trefoil Factor (TFF) family, and Ras-Associated Binding 25 (RAB25), while enhancing the expression of inducers of the drug sensitivity markers [e.g., Serum Amyloid A (SAA) family], could potentially reduce drug resistance and enhance the effectiveness of chemotherapy for gastric cancer. We expect that the developed strategy will serve as a useful tool for uncovering cancer-related phenotype-specific gene regulatory networks that provide essential clues for uncovering not only drug resistance mechanisms but also complex biological systems of cancer.

Epoxide-Mediated Trans-Thioglycosylation and Application to the Synthesis of Oligosaccharides Related to the Capsular Polysaccharides of C. jejuni HS:4.

The enzyme-resistant thioglycosides are highly valuable immunogens because of their enhanced metabolic stability. We report the first synthesis of a family of thiooligosaccharides related to the capsular polysaccharides (CPS) of Campylobacter jejuni HS:4 for potential use in conjugate vaccines. The native CPS structures of the pathogen consist of a challenging repeating disaccharide formed with β(1→4)-linked 6-deoxy-β-D-ido-heptopyranoside and N-acetyl-D-glucosamine; the rare 6-deoxy-ido-heptopyranosyl backbone and β-anomeric configuration of the former monosaccharide makes the synthesis of this family of antigens very challenging. So far, no synthesis of the thioanalogs of the CPS antigens have been reported. The unprecedented synthesis presented in this work is built on an elegant approach by using β-glycosylthiolate as a glycosyl donor to open the 2,3-epoxide functionality of pre-designed 6-deoxy-β-D-talo-heptopyranosides. Our results illustrated that this key trans-thioglycosylation can be designed in a modular and regio and stereo-selective manner. Built on the success of this novel approach, we succeeded the synthesis of a family of thiooligosaccharides including a thiohexasaccharide which is considered to be the desired antigen length and complexity for immunizations. We also report the first direct conversion of base-stable but acid-labile 2-trimethylsilylethyl glycosides to glycosyl-1-thioacetates in a one-pot manner.

Melanoma Antigen Family A (MAGE A) as Promising Biomarkers and Therapeutic Targets in Bladder Cancer.

The Melanoma Antigen Gene (MAGE) is a large family of highly conserved proteins that share a common MAGE homology domain. Interestingly, many MAGE family members exhibit restricted expression in reproductive tissues but are abnormally expressed in various human malignancies, including bladder cancer, which is a common urinary malignancy associated with high morbidity and mortality rates. The recent literature suggests a more prominent role for MAGEA family members in driving bladder tumorigenesis. This review highlights the role of MAGEA proteins, the potential for them to serve as diagnostic or prognostic biomarker(s), and as therapeutic targets for bladder cancer.

SPAG6 regulates cell proliferation and apoptosis via TGF-β/Smad signal pathway in adult B-cell acute lymphoblastic leukemia.

Adult B-cell acute lymphoblastic leukemia (B-ALL) prognosis remains unsatisfactory, and searching for new therapeutic targets is crucial for improving patient prognosis. Sperm-associated antigen 6 (SPAG6), a member of the cancer-testis antigen family, plays an important role in tumors, especially hematologic tumors; however, it is unknown whether SPAG6 plays a role in adult B-ALL. In this study, we demonstrated for the first time that SPAG6 expression was up-regulated in the bone marrow of adult B-ALL patients compared to healthy donors, and expression was significantly reduced in patients who achieved complete remission (CR) after treatment. In addition, patients with high SPAG6 expression were older (≥ 35years; P = 0.015), had elevated white blood cell counts (WBC > 30 × 109/L; P = 0.021), and a low rate of CR (P = 0.036). We explored the SPAG6 effect on cell function by lentiviral transfection of adult B-ALL cell lines BALL-1 and NALM-6, and discovered that knocking down SPAG6 significantly inhibited cell proliferation and promoted apoptosis. We identified that SPAG6 knockdown might regulate cell proliferation and apoptosis via the transforming growth factor-β (TGF-β)/Smad signaling pathway.

Proteomic Analysis Revealed the Potential Role of MAGE-D2 in the Therapeutic Targeting of Triple-Negative Breast Cancer

Among all the molecular subtypes of breast cancer, triple-negative breast cancer (TNBC) is the most aggressive one. Currently, the clinical prognosis of TNBC is poor because there is still no effective therapeutic target. Here, we carried out a combined proteomic analysis involving bioinformatic analysis of the proteome database, label-free quantitative proteomics, and immunoprecipitation (IP) coupled with mass spectrometry (MS) to explore potential therapeutic targets for TNBC. The results of bioinformatic analysis showed an overexpression of MAGE-D2 (melanoma antigen family D2) in TNBC. In vivo and in vitro experiments revealed that MAGE-D2 overexpression could promote cell proliferation and metastasis. Furthermore, label-free quantitative proteomics revealed that MAGE-D2 acted as a cancer-promoting factor by activating the PI3K–AKT pathway. Moreover, the outcomes of IP–MS and cross-linking IP–MS demonstrated that MAGE-D2 could interact with Hsp70 and prevent Hsp70 degradation, but evidence for their direct interaction is still lacking. Nevertheless, MAGE-D2 is a potential therapeutic target for TNBC, and blocking MAGE-D2 may have important therapeutic implications.

Altered RNA Export in SF3B1 Mutants Increases Sensitivity to Nuclear Export Inhibition

SF3B1 mutations are the most frequent spliceosomal alterations across cancers, yet no successful therapy exists to target this pathway. Previous findings from a phase 2 clinical trial of the XPO1 inhibitor selinexor in patients with high-risk myelodysplastic syndrome (MDS) relapsed or refractory to hypomethylating agents (HMA) revealed increased activity in patients with SF3B1 mutations. XPO1 (Exportin-1) is responsible for the nuclear export of over 200 proteins, but also plays a role in the transport of multiple RNA species, including small nuclear RNAs (snRNAs), ribosomal RNAs (rRNAs), and select messenger RNAs (mRNAs) out of the nucleus. Given the role of XPO1 in exporting snRNAs, which form the catalytic portion of the spliceosome, we hypothesized that XPO1 inhibition may preferentially affect SF3B1-mutant cells via altered splicing, and that SF3B1-mutant high-risk MDS patients would have a better response to rational targeted drug combinations with next generation XPO1 inhibitors. To evaluate the mechanism underlying the preferential sensitivity of SF3B1-mutant cells to XPO1 inhibition, we performed nuclear and cytoplasmic fractionation followed by RNA sequencing (subcellular RNA-seq) before and after XPO1 inhibition in SF3B1 wildtype and SF3B1 K666N mutant cells. Whole transcriptomic analysis of subcellular RNA-seq data revealed increased global retention of RNA transcripts in the nucleus after XPO1 inhibition in the SF3B1 mutant cell line ( Figure 1). Validation assays using qPCR confirmed nuclear retention of several key transcripts such as Salt Inducible Kinase 1 (SIK1) and Cancer/Testis Antigen Family 45 Member A2 (CT45A2) in SF3B1-mutants (both SF3B1 K666N and K700E). Similarly, we performed subcellular RNA-seq for small RNAs and found snRNAs to be increased in the nucleus after XPO1 inhibition in the SF3B1 mutant cells. We then performed total cellular RNA sequencing to understand the effect of XPO1 inhibition on global RNA expression and RNA splicing. Differential gene expression analysis revealed that XPO1 inhibition had a more pronounced effect on cell cycle in SF3B1 wildtype cells, but differentiation pathways were more significantly affected in SF3B1-mutant cells. Alternative splicing analysis showed increased 3' alternative splicing events in SF3B1 mutant after XPO1 inhibition. These results suggest that the preferential sensitivity of SF3B1 mutant cells to nuclear export inhibition arises through increased nuclear retention of spliceosomal snRNAs and select mRNAs that results in perturbation of differentiation pathways. Despite the promising efficacy of XPO1 inhibition in SF3B1 mutated MDS, toxicity limits its dose escalation. Combination therapies may allow for greater synergism with lower doses of XPO1 inhibitor. In order to identify novel drug combination targets, we employed whole genome CRISPR screens in two myeloid leukemia cell lines treated with eltanexor, a next generation XPO1 inhibitor with lower toxicity than selinexor ( Figure 2). These analyses identified several novel targets, which we validated by testing for synergy in combination with eltanexor in wildtype and SF3B1-mutant cell lines. Using the Bliss independence model to calculate synergy, we identifed two drugs that greatly synergized with eltanexor specifically in the SF3B1 mutant cell lines: venetoclax (a BCL2 inhibitor), and navitoclax (a BCL2/BCL-XL inhibitor). We further validated these combinations in vivo using competitive transplant assays in Sf3b1 K700E conditional knock-in mice. The combination of eltanexor with venetoclax showed a significant decrease in the Sf3b1-mutant burden in the peripheral blood and bone marrow progenitor compartments, suggesting a preferential sensitivity of the combination for SF3B1 mutation. In conclusion, by analyzing the effects of XPO1 inhibition on RNA export, our study provides insight on the mechanisms behind the increased efficacy of XPO1 inhibition in SF3B1-mutant MDS/AML. Our findings may also contribute to the development of potentially synergistic therapeutic combinations. In this regard, recent human data have shown that venetoclax can overcome the poor prognosis of spliceosomal mutant AML patients (Senapati et al, Blood 2023); therefore, combining eltanexor with venetoclax could represent a promising SF3B1-specific therapy.