Cancer/testis antigens and urological malignancies

A comprehensive pan-cancer analysis revealing SPAG6 as a novel diagnostic, prognostic and immunological biomarker in tumor

Background

There have been studies on the role of sperm-associated antigen 6 (SPAG6) in cytoskeleton formation and growth cone stability, but it is also unknown how spag6 affect tumor growth and development. The aim of this study was to clarify the role of SPAG6 in pan-cancer, with some findings about thyroid carcinoma (THCA) validated through experiments.

Methods

We examined the role of SPAG6 in pan-cancer, with the data being collected from databases. Further analysis was conducted to assess its correlations with prognosis, gene heterogeneity, stemness, and tumor immunity. The interacting proteins of SPAG6 were also identified, and gene ontology enrichment analysis was performed to determine its biological function. We preliminarily confirmed the role of SPAG6 via in vitro experiments and immunofluorescence staining.

Results

This study found that SPAG6 expression was differentially expressed in cancers and at various tumor stages and grades. In stomach and esophageal carcinoma (STES), stomach adenocarcinoma (STAD), kidney renal clear cell carcinoma (KIRC), lung squamous cell carcinoma (LUSC), and adrenocortical carcinoma (ACC), SPAG6 expression was correlated with gender. SPAG6 expression was also found to be correlated with prognostic value, with low expression being associated with poor prognosis. Furthermore, SPAG6 expression was positively linked with immune-related cells in HNSC, chemokine receptors in LUSC, and immune checkpoint genes in THCA. Furthermore, SPAG6 overexpression suppressed the malignant phenotypes of THCA cells, manifested by slower proliferation and decreased migration. The different SPAG6 expression in THCA led to different malignant phenotypes, which are involved in the upregulation of DNA repair, MYC targets, peroxisome, and G2M checkpoint.

Conclusions

SPAG6 plays a significant role as an oncogene and can be used as a marker to predict the prognosis of cancer. SPAG6 influences both the tumor immune infiltration and microenvironment, making it a promising immunotherapeutic target for tumor therapy.

Overexpression of Transmembrane Phosphatase with Tensin homology (TPTE) in prostate cancer is clinically significant, suggesting its potential as a valuable biomarker

PURPOSE

Cancer testis antigens (CTAs) are a family of proteins typically expressed in male testicles but overexpressed in various cancer cell types. Transmembrane Phosphatase with Tensin homology (TPTE) is expressed only in the testis of healthy individuals and is a member of the family of CTAs. The current study, for the first time, examined the significance of TPTE expression in prostate cancer (PCa) tissues by generating a novel antibody marker targeting TPTE protein.

METHODS

Polyclonal antibodies were prepared for TPTE-p1 and TPTE-p2 peptides, which are derived from the extracellular domains of TPTE. Anti-TPTE-p2 antibody was then used to study the extent and pattern of TPTE expression in 102 PCa and 48 benign prostatic hyperplasia (BPH) tissue samples by immunohistochemistry. The viability of cancer cell lines (PC-3 and MCF-7 cells) was also evaluated in the presence of anti-TPTE-p2 antibody using the MTT test.

RESULTS

The immunohistochemical analysis demonstrated a significant increase in cytoplasmic and membrane TPTE expression in the PCa samples compared to the BPH group (both P < 0.0001). Cytoplasmic TPTE expression was positively correlated with Gleason score and PSA levels (P = 0.03 and P = 0.001, respectively). Significant correlations were identified between the levels of PSA and perineural invasion and the membrane expression (P = 0.01, P = 0.04, respectively). Moreover, anti-TPTE-p2 antibody inhibited PC-3 and MCF-7 cells proliferation compared to the control group for 24 h (P < 0.001 and P = 0.001, respectively) as well as for 48 h (P = 0.001 and P = 0.001, respectively).

CONCLUSION

Our findings indicate that increased TPTE expression is associated with progression of disease. The ability of anti-TPTE-p2 antibody to recognize and target the TPTE protein makes it a potential biomarker to assess and/or target the PCa.

Humoral immunoprofiling identifies novel biomarkers and an immune suppressive autoantibody phenotype at the site of disease in pancreatic ductal adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) is a heterogeneous cancer, with minimal response to therapeutic intervention and with 85% of cases diagnosed at an advanced stage due to lack of early symptoms, highlighting the importance of understanding PDAC immunology in greater detail. Here, we applied an immunoproteomic approach to investigate autoantibody responses against cancer-testis and tumor-associated antigens in PDAC using a high-throughput multiplexed protein microarray platform, comparing humoral immune responses in serum and at the site of disease in order to shed new light on immune responses in the tumor microenvironment. We simultaneously quantified serum or tissue IgG and IgA antibody isotypes and subclasses in a cohort of PDAC, disease control and healthy patients, observing inter alia that subclass utilization in tumor tissue samples was predominantly immune suppressive IgG4 and inflammatory IgA2, contrasting with predominant IgG3 and IgA1 subclass utilization in matched sera and implying local autoantibody production at the site of disease in an immune-tolerant environment. By comparison, serum autoantibody subclass profiling for the disease controls identified IgG4, IgG1, and IgA1 as the abundant subclasses. Combinatorial analysis of serum autoantibody responses identified panels of candidate biomarkers. The top IgG panel included ACVR2B, GAGE1, LEMD1, MAGEB1 and PAGE1 (sensitivity, specificity and AUC values of 0.933, 0.767 and 0.906). Conversely, the top IgA panel included AURKA, GAGE1, MAGEA10, PLEKHA5 and XAGE3aV1 (sensitivity, specificity, and AUC values of 1.000, 0.800, and 0.954). Assessment of antigen-specific serum autoantibody glycoforms revealed abundant sialylation on IgA in PDAC, consistent with an immune suppressive IgA response to disease.

Investigating the inhibitory and penetrating properties of three novel anticancer and antimicrobial scorpion peptides via molecular docking and molecular dynamic simulation

The two types of bladder cancer, muscle invasive and non-muscle invasive (NMIBC), are among the most prevalent cancers worldwide. Despite this, even though muscle-invasive bladder cancer is more deadly, NMIBC requires more therapy due to a greater recurrence rate and more extended and expensive care. Immunotherapy, intravesical chemotherapy, cystoscopy, and transurethral resection (TUR) are among the treatments available. Crude scorpion venomand purified proteins and peptides, can suppress cancer metastasis in an in vitro or in vivo context, suppress cancer growth, halt the cell cycle, and cause cell apoptosis, according to an increasing number of experimental and preclinical studies. In this research, three novels discovered peptides (P2, P3 and P4. ProteomeXchange: PXD036231) from Buthotus saulcyi and, Odontobuthus doriae scorpions were used along with a peptide called pantinin (as a control). The phylogenetic tree showed that the peptides belong to Chaperonin HSP60, Chrysophsin2 and Pheromone-binding protein2, respectively. These peptides were docked with four known antigens, BAGE, BLCAP, PRAME and ROR1 related to bladder cancer and three bacterial antigens FliC, FliD and FimH to investigate their antimicrobial and anticancer properties. The results showed that peptides 2 and 3 have the best binding rate. The MD simulation results also confirmed the binding of peptides 2 and 3 to antigens. The penetration power of peptides 2 and 3 in the membrane of cancer cells and bacterial cells was also simulated, and the results of RMSD and PD confirmed it. QSAR suggests that peptides 2 and 3 can act as anti-cancer and anti-microbial peptides.Communicated by Ramaswamy H. Sarma.

Construction and systematic evaluation of a machine learning-based cuproptosis-related lncRNA score signature to predict the response to immunotherapy in hepatocellular carcinoma

Introduction

Hepatocellular carcinoma (HCC) is a common malignant cancer with a poor prognosis. Cuproptosis and associated lncRNAs are connected with cancer progression. However, the information on the prognostic value of cuproptosis-related lncRNAs is still limited in HCC.

Methods

We isolated the transcriptome and clinical information of HCC from TCGA and ICGC databases. Ten cuproptosis-related genes were obtained and related lncRNAs were correlated by Pearson's correlation. By performing lasso regression, we created a cuproptosis-related lncRNA prognostic model based on the cuproptosis-related lncRNA score (CLS). Comprehensive analyses were performed, including the fields of function, immunity, mutation and clinical application, by various R packages.

Results

Ten cuproptosis-related genes were selected, and 13 correlated prognostic lncRNAs were collected for model construction. CLS was positively or negatively correlated with cancer-related pathways. In addition, cell cycle and immune related pathways were enriched. By performing tumor microenvironment (TME) analysis, we determined that T-cells were activated. High CLS had more tumor characteristics and may lead to higher invasiveness and treatment resistance. Three genes (TP53, CSMD1 and RB1) were found in high CLS samples with more mutational frequency. More amplification and deletion were detected in high CLS samples. In clinical application, a CLS-based nomogram was constructed. 5-Fluorouracil, gemcitabine and doxorubicin had better sensitivity in patients with high CLS. However, patients with low CLS had better immunotherapeutic sensitivity.

Conclusion

We created a prognostic CLS signature by machine learning, and we comprehensively analyzed the signature in the fields of function, immunity, mutation and clinical application.

The Transcriptome and Proteome Networks of Malignant Tumours Reveal Atavistic Attractors of Polyploidy-Related Asexual Reproduction

The expression of gametogenesis-related (GG) genes and proteins, as well as whole genome duplications (WGD), are the hallmarks of cancer related to poor prognosis. Currently, it is not clear if these hallmarks are random processes associated only with genome instability or are programmatically linked. Our goal was to elucidate this via a thorough bioinformatics analysis of 1474 GG genes in the context of WGD. We examined their association in protein-protein interaction and coexpression networks, and their phylostratigraphic profiles from publicly available patient tumour data. The results show that GG genes are upregulated in most WGD-enriched somatic cancers at the transcriptome level and reveal robust GG gene expression at the protein level, as well as the ability to associate into correlation networks and enrich the reproductive modules. GG gene phylostratigraphy displayed in WGD+ cancers an attractor of early eukaryotic origin for DNA recombination and meiosis, and one relative to oocyte maturation and embryogenesis from early multicellular organisms. The upregulation of cancer-testis genes emerging with mammalian placentation was also associated with WGD. In general, the results suggest the role of polyploidy for soma-germ transition accessing latent cancer attractors in the human genome network, which appear as pre-formed along the whole Evolution of Life.

Cancer-testis antigen lactate dehydrogenase C4 as a novel biomarker of male infertility and cancer

A unique lactate dehydrogenase (LDH) isoenzyme designated as lactate dehydrogenase C4 (LDH-C4) is found in mammalian mature testis and spermatozoa. Thus far, LDH-C4 has been well studied with regard to its gene and amino acid sequences, structure, biological properties, and peptide synthesis. Accumulating evidence has shown that LDH-C4 is closely related to spermatic energy metabolism and plays a critical role in sperm motility, capacitation, and fertilization. Defects in the catalytic activity of LDH-C4 are key to pathophysiological abnormalities underlying infertility. LDH-C4 was originally thought to be present only in mature testis and spermatozoa; however, recent studies have implicated LDH-C4 as a cancer-testis antigen (CTA), owing to its aberrant transcription in a broad spectrum of human neoplasms. This review highlights the recent findings on LDH-C4 with particular emphasis on its role in male infertility and tumors.

A Novel Multiepitope Vaccine Against Bladder Cancer Based on CTL and HTL Epitopes for Induction of Strong Immune Using Immunoinformatics Approaches

Bladder cancer is well-known cancer in two forms of muscle-invasive and non-muscle-invasive bladder cancer which is responsible for annual deaths worldwide. Common therapies methods are somewhat successful; however, these methods have the limitations such as the side effects of chemotherapy which necessitate the requirement for new preventive methods against bladder cancer. Hence, we explain a novel designed multi-epitope vaccine against bladder cancer using the immunoinformatics tool. Three well-known BLCAP, PRAM, and BAGE4 antigens were evaluated due to most repetitive CTL and HTL epitopes binding. IFNγ and IL10 inducer potential of selected epitopes were investigated, as well as liner and conformational B-cell epitopes. Human beta-defensin 3 and PADRE sequence were added to construct as adjuvants, along with EAAAK, AAY, and GGGS linkers to fuse CTL and HTL epitopes. Results showed this construct encodes a soluble, non-toxic, and non-allergic protein with 70 kDa molecular weight. Modeled 3D structure of vaccine was docked whit Toll-Like Receptors (TLR) of 7/8. Docking, molecular dynamics simulation and MMBPSA analysis confirmed stability of vaccine-TLR complexes. The immunogenicity showed this construct could elicit humoral and cellular immune responses. In silico and immunoinformatics evaluations suggest that this construct is a recombinant candidate vaccine against bladder cancer.

Actin-like protein 8, a member of cancer/testis antigens, supports the aggressive development of oral squamous cell carcinoma cells via activating cell cycle signaling

Due to the malignancy of oral squamous cell carcinoma (OSCC), investigations of novel therapeutic targets and prognostic biomarkers are urgently needed. In our present study, significant up-regulation of Actin-like protein 8 (ACTL8) in OSCC patients was observed by bioinformatics analysis with RNA sequencing data obtained from The Cancer Genome Atlas (TCGA) database. The results of Chi-square test revealed that there was a significant correlation between ACTL8 expression and tumor status (T1 + T2/T3+T4) (P = 0.004). Survival analysis indicated a negative correlation between ACTL8 overexpression and prognosis in OSCC (P = 3.984e-02). An ACTL8 knockdown experiment was conducted to evaluate the function of ACTL8 on OSCC cell biological behaviors. The results revealed that knockdown of ACTL8 significantly inhibited the growth and mobility, arrested cell cycle and promoted apoptosis of TCA-83 and CAL27 cells. Moreover, Gene Set Enrichment Analysis (GSEA) and western blots demonstrated that activation of cell cycle signaling pathway was inhibited by knockdown of ACTL8, as we observed the down-regulation of 4 key proteins (CDK1, cyclin E1, cyclin B2 and c-Myc) in this pathway. The present investigation indicates that ACTL8 plays an oncogenic role in the pathogenesis of OSCC, suggesting that ACTL8 may be a promising therapeutic target and prognosis marker for human OSCC.

Identification and validation of the high expression of pseudogene TCAM1P in cervical cancer via integrated bioinformatics analysis

Background

HPV as the main cause of cervical cancer has long been revealed, but the detailed mechanism has not yet been elucidated. The role of testis/cancer antigen in cervical cancer has been revealed. However, there are no reports about the statement of testis/cancer-specific non-coding RNA. In this study, we first proposed TCAM1P as a testis/cancer-specific pseudogene, and used a series of experimental data to verify its relationship with HPV, and analyzed its diagnosis value of high-grade cervical lesions and the mechanism of their high expression in cervical cancer. This provides a new direction for the prevention and treatment of cervical cancer.

Methods

The specific expression of pseudogenes in each tissue was calculated by “TAU” formula. ROC curve was used to judge the diagnosed value of TCAM1P for high-grade lesions. The proliferation ability of cells was measured by CCK8. The expression of TCAM1P, HPV E6/E7 were detected by qRT-PCR. The binding for RBPs on TCAM1P was predicted by starbase v2.0 database, then RIP assay was used to verify. Besides, Gene Ontology (GO) and KEGG enrichment analysis were performed with “clusterprofiler” R package.

Results

TCAM1P was specifically high-expressed in normal testicular tissue and cervical cancer. Interesting, with the severity of cervical lesions increased, the expression of TCAM1P increased, and TCAM1P could effectively diagnose high-grade cervical lesions. Besides, the expression of TCAM1P was HPV dependent, with highest expression in HPV-positive cervical cancer tissues. Furthermore, RIP assay showed that EIF4A3 regulated the expression of TCAM1P through binding with it. CCK8 assay showed that TCAM1P promoted the proliferation and the Gene ontology (GO) and KEGG Pathway enrichment analysis same suggested that TCAM1P is involved in multiple ways in cell proliferation including Cell cycle, DNA replication and etc.

Conclusions

In this study, we firstly proposed that TCAM1P is cancer/testis pseudogene and is regulated by HPV E6/E7 and EIF4A3. TCAM1P promotes the proliferation of cervical cancer cells and acts as promoter in cervical cancer. Otherwise, TCAM1P promote proliferation through regulating cell cycle and DNA replication, but more evidence needs to be provided to reveal the mechanism by which TCAM1P plays a role in cervical cancer.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12935-021-02440-7.

Nanomaterial-based delivery vehicles for therapeutic cancer vaccine development

Nanomaterial-based delivery vehicles such as lipid-based, polymer-based, inorganics-based, and bio-inspired vehicles often carry distinct and attractive advantages in the development of therapeutic cancer vaccines. Based on various delivery vehicles, specifically designed nanomaterials-based vaccines are highly advantageous in boosting therapeutic and prophylactic antitumor immunities. Specifically, therapeutic vaccines featuring unique properties have made major contributions to the enhancement of antigen immunogenicity, encapsulation efficiency, biocompatibility, and stability, as well as promoting antigen cross-presentation and specific CD8+ T cell responses. However, for clinical applications, tumor-associated antigen-derived vaccines could be an obstacle, involving immune tolerance and deficiency of tumor specificities, in achieving maximum therapeutic indices. However, when using bioinformatics predictions with emerging innovations of in silico tools, neoantigen-based therapeutic vaccines might become potent personalized vaccines for tumor treatments. In this review, we summarize the development of preclinical therapeutic cancer vaccines and the advancements of nanomaterial-based delivery vehicles for cancer immunotherapies, which provide the basis for a personalized vaccine delivery platform. Moreover, we review the existing challenges and future perspectives of nanomaterial-based personalized vaccines for novel tumor immunotherapies.

Plac1 promotes nasopharyngeal carcinoma cells proliferation, migration and invasion via Furin/NICD/PTEN pathway

Placenta-specific protein 1 (Plac1) has critical functions in multiple human malignancies, but its role in nasopharyngeal carcinoma (NPC) was unclear. Clinical samples of NPC and adjacent normal tissue were collected. Plac1 expressions in both tissues and cells were measured. After cell transfection, NPC cell viability, proliferation, migration and invasion were detected using cell counting kit-8 (CCK-8) assay, colony formation assay, scratch assay and Transwell assay. Relative expressions of Plac1 and proteins related to migration and invasion (E-Cadherin, N-cadherin, Matrix metalloproteinase2 (MMP2), and MMP9), Furin/Notch1 intracellular domain (NICD)/phosphate and tension homology (PTEN) pathway (NICD, PTEN, phosphorylated-Akt (p-Akt), Akt) were quantified by quantitative real-time polymerase chain reaction (qRT-PCR) and Western blot as needed. The interaction between Plac1 and Furin, a member of Furin/NICD/PTEN Pathway, was analyzed using co-Immunoprecipitation (co-IP) assay. Plac1 expression was upregulated in both NPC tissue and cells. Overexpressed Plac1 promoted Plac1 and Furin expressions and increased cell viability, proliferation, migration and invasion of NPC cells, while silencing Plac1 showed the opposite effects. Plac1 interacted with Furin, overexpression of Furin reversed the inhibitory effects of silencing Plac1 on NPC cell proliferation, migration, and invasion, and also reversed the effects of silencing Plac1 on Furin/NICD/PTEN pathway-, cell migration-, and invasion-related protein expressions. Plac1 promoted NPC cell proliferation, migration and invasion via Furin/NICD/PTEN Pathway. The findings of this study provide a possible therapeutic method for NPC treatment.

The expression, modulation and use of cancer-testis antigens as potential biomarkers for cancer immunotherapy

Cancer-testis antigens (CTA) are tumor antigens, present in the germ cells of testes, ovaries and trophoblasts, which undergo deregulated expression in the tumor and malignant cells. CTA genes are either X-linked or autosomal, favourably expressed in spermatogonia and spermatocytes, respectively. CTAs trigger unprompted humoral immunity and immune responses in malignancies, altering tumor cell physiology and neoplastic behaviors. CTAs demonstrate varied expression profile, with increased abundance in malignant melanoma and prostate, lung, breast and epithelial cell cancers, and a relatively reduced prevalence in intestinal cancer, renal cell adenocarcinoma and malignancies of immune cells. A combination of epigenetic and non-epigenetic agents regulates CTA mRNA expression, with the key participation of CpG islands and CpG-rich promoters, histone methyltransferases, cytokines, tyrosine kinases and transcriptional activators and repressors. CTA triggers gametogenesis, in association with mutated tumorigenic genes and tumor repressors. The CTAs function as potential biomarkers, particularly for prostate, cervical, breast, colorectal, gastric, urinary bladder, liver and lung carcinomas, characterized by alternate splicing and phenotypic heterogeneity in the cells. Additionally, CTAs are prospective targets for vaccine therapy, with the MAGE-A3 and NYESO-1 undergoing clinical trials for tumor regression in malignant melanoma. They have been deemed important for adaptive immunotherapy, marked by limited expression in normal somatic tissues and recurrent up-regulation in epithelial carcinoma. Overall, the current review delineates an up-dated understanding of the intricate processes of CTA expression and regulation in cancer. It further portrays the role of CTAs as biomarkers and probable candidates for tumor immunotherapy, with a future prospect in cancer treatment.

In silico Evaluation of PLAC1-fliC As a Chimeric Vaccine against Breast Cancer

Background

Breast cancer is one of the most prevalent cancers among women. Common cancer treatment methods are not effective enough, and there is a need for a more efficient treatment procedure. Cancer vaccine is a novel immunotherapy method that stimulates humoral and/or cellular immunity against cancer. Placenta-specific protein 1 (PLAC1) is a cancer/testis antigen, prevalent in breast cancer and rarely found in normal tissues. FliC, as a bacterial adjuvant, when fused to PLAC1 can elicit humoral and cellular responses. Therefore, PLAC1-fliC is a chimeric protein, which can be considered a suitable candidate against breast cancer.

Methods

ProtParam was used to evaluate the physicochemical properties of PLAC1-fliC. Second structures were determined using the GOR V server. PLAC1-fliC 3D structure was modeled by Phyre2, and it was refined using GalaxyWEB. The refined model was submitted to RAMPAGE, PROCHECK, and ProSA-web for validation. Antigenicity and allergenicity of the construct were predicted by ANTIGENpro, VaxiJen, AllergenFP, and SDAP databases. Then MHC-I- and MHC-II-binding epitopes of PLAC1-fliC were forecasted by NetMHC 4.0 and NetMHCII 2.3 Servers. Finally, Ellipro and CTLpred were employed to predict B-cell and cytotoxic T lymphocyte epitopes.

Results

The construct was evaluated as a stable fusion protein, which could be antigenic and could stimulate B and T cells against breast cancer.

Conclusion

PLAC1-fliC, as a cancer vaccine candidate, might be suitable and specific for breast cancer, which could evoke humoral and cellular immunity against this type of tumor.

Ursolic acid promotes apoptosis and mediates transcriptional suppression of CT45A2 gene expression in non-small-cell lung carcinoma harbouring EGFR T790M mutations

BACKGROUND AND PURPOSE

In non-small-cell lung carcinoma (NSCLC) patients, the L858R/T790M mutation of the epithelial growth factor receptor (EGFR) is a major cause of acquired resistance to EGFR-TKIs treatment that limits their therapeutic efficacy. Identification of drugs that can preferentially kill the NSCLC harbouring L858R/T790M mutation is therefore critical. Here, we have evaluated the effects of ursolic acid, an active component isolated from herbal sources, on erlotinib-resistant H1975 cells that harbour the L858R/T790M mutation.

EXPERIMENTAL APPROACH

Gene expression omnibus (GEO) profiles analyses was applied to detect differentially expressed genes in NSCLC cells harbouring EGFR mutation. AnnexinV-FITC/PI, TUNEL staining, MTT, wound healing, RT-PCR, qRT-PCR, western blots, immunostaining, dual-luciferase reporters and ChIP-PCR were utilized to investigate the effects of ursolic acid in vitro and in vivo.

KEY RESULTS

The cancer/testis antigen family 45 member A2 (CT45A2) was highly expressed in H1975 cells. Ectopic expression of CT45A2 in H1975 cells increased cell proliferation and motility in vitro. Silencing the CT45A2 expression strongly attenuated H1975 cells motility and growth. The anti-cancer effect of ursolic acid was critically dependent on CT45A2 expression in H1975 cells. Ursolic acid suppressed CT45A2 gene transcription mediated by transcriptional factor TCF4 and β-catenin signalling.

CONCLUSIONS AND IMPLICATIONS

CT45A2 is a novel oncogene for NSCLC with an EGFR T790 mutation. Ursolic acid induced apoptosis and inhibited proliferation of H1975 cells by negatively regulating the β-catenin/TCF4/CT45A2 signalling pathway. Therefore, ursolic acid may be a potential candidate treatment for NSCLC harbouring the EGFR-L858R/T790M mutation.

In silico Evaluation of PLAC1-fliC As a Chimeric Vaccine against Breast Cancer

Background

Breast cancer is one of the most prevalent cancers among women. Common cancer treatment methods are not effective enough, and there is a need for a more efficient treatment procedure. Cancer vaccine is a novel immunotherapy method that stimulates humoral and/or cellular immunity against cancer. Placenta-specific protein 1 (PLAC1) is a cancer/testis antigen, prevalent in breast cancer and rarely found in normal tissues. FliC, as a bacterial adjuvant, when fused to PLAC1 can elicit humoral and cellular responses. Therefore, PLAC1-fliC is a chimeric protein, which can be considered a suitable candidate against breast cancer.

Methods

ProtParam was used to evaluate the physicochemical properties of PLAC1-fliC. Second structures were determined using the GOR V server. PLAC1-fliC 3D structure was modeled by Phyre2, and it was refined using GalaxyWEB. The refined model was submitted to RAMPAGE, PROCHECK, and ProSA-web for validation. Antigenicity and allergenicity of the construct were predicted by ANTIGENpro, VaxiJen, AllergenFP, and SDAP databases. Then MHC-I- and MHC-II-binding epitopes of PLAC1-fliC were forecasted by NetMHC 4.0 and NetMHCII 2.3 Servers. Finally, Ellipro and CTLpred were employed to predict B-cell and cytotoxic T lymphocyte epitopes.

Results

The construct was evaluated as a stable fusion protein, which could be antigenic and could stimulate B and T cells against breast cancer.

Conclusion

PLAC1-fliC, as a cancer vaccine candidate, might be suitable and specific for breast cancer, which could evoke humoral and cellular immunity against this type of tumor.

Identification of cancer/testis antigen 2 gene as a potential hepatocellular carcinoma therapeutic target by hub gene screening with topological analysis

The 5-year survival rate of hepatocellular carcinoma (HCC) is <20%; thus, identifying new potential therapeutic targets or novel biomarkers for prognosis prediction is crucial. The present study aimed to screen hub genes by constructing protein-protein interaction (PPI) subnetworks using topological analysis methods, as well as reveal their clinical significance through big data analytics and their association with the clinicopathological features. Firstly, the PPI subnetworks were constructed using four topological analysis methods, including the MCC, DMNC, MNC and degree methods, to obtain 6 hub genes. Subsequently, the hub gene cancer/testis antigen 2 (CTAG2), which affects the prognosis of HCC (overall survival, P=0.035), was acquired by analysing clinical data in The Cancer Genome Atlas database. Meanwhile, CTAG2 expression was significantly associated with the age at diagnosis (P=0.003), T stage (P=0.028), TNM stage (P=0.028) and α-fetoprotein (AFP) expression (P=0.045). Further immunohistochemical analysis of samples collected in our hospital revealed that the expression level of CTAG2 in 46 HCC tissues was significantly higher in comparison with that in paired adjacent tissues. The clinical data indicated that the expression of CTAG2 was significantly correlated with the hepatitis B virus status (P=0.010) and AFP expression (P=0.004). These results were then found to be consistent with the results of big data analytics. Furthermore, Gene Set Enrichment Analysis demonstrated that the function of CTAG2 in HCC may be associated with the cell cycle. Taken together, these findings suggest that CTAG2 may serve as a new potential therapeutic target for HCC patients.

Expression analysis of a panel of cancer-testis antigens in bladder cancer

AIM

Cancer-testis antigens (CTAs) have specific expression in gametogenic tissues and aberrant expression in cancers. Materials & methods: We assessed expression of five testis-specific genes namely KIF2B, CST8, TMEM225, RBM46, OAZ3 in bladder cancer tissues, adjacent non-neoplastic tissues and urinary cell pellets (UCPs) of bladder cancer patients compared with nonmalignant conditions.

RESULTS

Expressions of all CTAs were higher in UCPs of bladder cancer patients compared with nonmalignant conditions. RBM46 expression in UCPs was higher in patients with recurrent tumors compared with primary tumors and in patients without hematuria compared with those having hematuria. TMEM225 expression in tumoral tissues was higher in high-grade tumors compared with low-grade tumors.

CONCLUSION

Expression analysis of CTAs in UCP might provide diagnostic information about bladder cancer.

Prostate-Associated Gene 4 (PAGE4): Leveraging the Conformational Dynamics of a Dancing Protein Cloud as a Therapeutic Target

Prostate cancer (PCa) is a leading cause of mortality and morbidity globally. While genomic alterations have been identified in PCa, in contrast to some other cancers, use of such information to personalize treatment is still in its infancy. Here, we discuss how PAGE4, a protein which appears to act both as an oncogenic factor as well as a metastasis suppressor, is a novel therapeutic target for PCa. Inhibiting PAGE4 may be a viable strategy for low-risk PCa where it is highly upregulated. Conversely, PAGE4 expression is downregulated in metastatic PCa and, therefore, reinstituting its sustained expression may be a promising option to subvert or attenuate androgen-resistant PCa. Thus, fine-tuning the levels of PAGE4 may represent a novel approach for personalized medicine in PCa.

Cancer/testis antigen-Plac1 promotes invasion and metastasis of breast cancer through Furin/NICD/PTEN signaling pathway

Placenta‐specific protein 1 (Plac1) is a cancer/testis antigen that plays a critical role in promoting cancer initiation and progression. However, the clinical significance and mechanism of Plac1 in cancer progression remain elusive. Here, we report that Plac1 is an important oncogenic and prognostic factor, which physically interacts with Furin to drive breast cancer invasion and metastasis. We have shown that Plac1 expression positively correlates with clinical stage, lymph node metastasis, hormone receptor status, and overall patient survival. Overexpression of Plac1 promoted invasion and metastasis of breast cancer cells in vitro and in vivo. Co‐immunoprecipitation and immunofluorescence cell staining assays revealed that interaction of Plac1 and Furin degraded Notch1 and generated Notch1 intracellular domain (NICD) that could inhibit PTEN activity. These findings are consistent with the results of microarray study in MDA‐MB‐231 cells overexpressing Plac1. A rescue study showed that inhibition of Furin and overexpression of PTEN in Plac1 overexpression cells blocked Plac1‐induced tumor cell progression. Taken together, our findings suggest that functional interaction between Plac1 and Furin enhances breast cancer invasion and metastasis and the Furin/NICD/PTEN axis may act as an important therapeutic target for breast cancer treatment.

Inducible expression of cancer-testis antigens in human prostate cancer

Immune tolerance to self-antigens can limit robust anti-tumor immune responses in the use of tumor vaccines. Expression of novel tumor associated antigens can improve immune recognition and lysis of tumor cells. The cancer-testis antigen (CTA) family of proteins has been hypothesized to be an ideal class of antigens due to tumor-restricted expression, a subset of which have been found to induce antibody responses in patients with prostate disease. We demonstrate that CTA expression is highly inducible in five different Prostate Cancer (PC) cell lines using a hypomethylating agent 5-Aza-2′-deoxycytidine (5AZA) and/or a histone deacetylase inhibitor LBH589. These CTAs include NY-ESO1, multiple members of the MAGE and SSX families and NY-SAR35. A subset of CTAs is synergistically induced by the combination of 5AZA and LBH589. We developed an ex vivo organ culture using human PC biopsies for ex vivo drug treatments to evaluate these agents in clinical samples. These assays found significant induction of SSX2 in 9/9 distinct patient samples and NY-SAR35 in 7/9 samples. Further, we identify expression of SSX2 in circulating tumor cells (CTC) from patients with advanced PC. These results indicate that epigenetic modifying agents can induce expression of a broad range of neoantigens in human PC and may serve as a useful adjunctive therapy with novel tumor vaccines and checkpoint inhibitors.

Novel potential serological prostate cancer biomarkers using CT100+ cancer antigen microarray platform in a multi-cultural South African cohort

There is a growing need for high throughput diagnostic tools for early diagnosis and treatment monitoring of prostate cancer (PCa) in Africa. The role of cancer-testis antigens (CTAs) in PCa in men of African descent is poorly researched. Hence, we aimed to elucidate the role of 123 Tumour Associated Antigens (TAAs) using antigen microarray platform in blood samples (N = 67) from a South African PCa, Benign prostatic hyperplasia (BPH) and disease control (DC) cohort. Linear (fold-over-cutoff) and differential expression quantitation of autoantibody signal intensities were performed. Molecular signatures of candidate PCa antigen biomarkers were identified and analyzed for ethnic group variation. Potential cancer diagnostic and immunotherapeutic inferences were drawn. We identified a total of 41 potential diagnostic/therapeutic antigen biomarkers for PCa. By linear quantitation, four antigens, GAGE1, ROPN1, SPANXA1 and PRKCZ were found to have higher autoantibody titres in PCa serum as compared with BPH where MAGEB1 and PRKCZ were highly expressed. Also, p53 S15A and p53 S46A were found highly expressed in the disease control group. Statistical analysis by differential expression revealed twenty-four antigens as upregulated in PCa samples, while 11 were downregulated in comparison to BPH and DC (FDR = 0.01). FGFR2, COL6A1and CALM1 were verifiable biomarkers of PCa analysis using urinary shotgun proteomics. Functional pathway annotation of identified biomarkers revealed similar enrichment both at genomic and proteomic level and ethnic variations were observed. Cancer antigen arrays are emerging useful in potential diagnostic and immunotherapeutic antigen biomarker discovery.

Effect of cancer/testis antigen NY-SAR-35 on the proliferation, migration and invasion of cancer cells

NY-SAR-35 is a cancer/testis (CT) antigen that was identified by serological analysis of recombinant complementary DNA expression libraries. The gene encoding NY-SAR-35 is located on the × chromosome and is aberrantly expressed in a number of cancer types and germ cells, such as those in the testes, but not in normal tissue. It has been reported that treatment with a demethylating agent induced the expression of NY-SAR-35 in several types of cancer cells. However, the function of NY-SAR-35 in cancer remains undetermined. In present study, the role of NY-SAR-35 in human lung adenocarcinoma (SK-LC-14) and hepatocellular carcinoma (SNU-449) cells was investigated following stable transfection of the NY-SAR-35 gene. NY-SAR-35 was observed to be expressed in the cytoplasm of the cells. In addition, the bromodeoxyuridine incorporation assay and immunofluorescence staining for proliferating cell nuclear antigen and Ki-67 demonstrated that proliferation was increased in cells transfected with NY-SAR-35. In addition, the trypan blue exclusion assay indicated that NY-SAR-35 increased cancer cell viability. Furthermore, NY-SAR-35 increased the migration and invasion of the cells. These results indicate that NY-SAR-35 increases cancer cell viability, proliferation, migration and invasion.

Genome-wide association study of prostate-specific antigen levels identifies novel loci independent of prostate cancer

Prostate-specific antigen (PSA) levels have been used for detection and surveillance of prostate cancer (PCa). However, factors other than PCa—such as genetics—can impact PSA. Here we present findings from a genome-wide association study (GWAS) of PSA in 28,503 Kaiser Permanente whites and 17,428 men from replication cohorts. We detect 40 genome-wide significant (P<5 × 10⁻⁸) single-nucleotide polymorphisms (SNPs): 19 novel, 15 previously identified for PSA (14 of which were also PCa-associated), and 6 previously identified for PCa only. Further analysis incorporating PCa cases suggests that at least half of the 40 SNPs are PSA-associated independent of PCa. The 40 SNPs explain 9.5% of PSA variation in non-Hispanic whites, and the remaining GWAS SNPs explain an additional 31.7%; this percentage is higher in younger men, supporting the genetic basis of PSA levels. These findings provide important information about genetic markers for PSA that may improve PCa screening, thereby reducing over-diagnosis and over-treatment.

Prostate-specific antigen is used as a biomarker of prostate cancer, but levels can be affected by other factors not related to cancer. Here, the authors find genes associated with prostate specific antigen levels in healthy men, which could be used to reduce over-diagnosis and over-treatment.

Specific autoantigens identified by sera obtained from mice that are immunized with testicular germ cells alone

There are various autoimmunogenic antigens (AIs) in testicular germ cells (TGCs) recognized as foreign by the body's immune system. However, there is little information of TGC-specific AIs being available. The aim of this study is to identify TGC-specific AIs. We have previously established that immunization using viable syngeneic TGC can also induce murine experimental autoimmune orchitis (EAO) without using any adjuvant. This study is to identify TGC-specific AIs by TGC liquid chromatography-tandem mass spectrometry analysis, followed by two-dimensional gel electrophoresis that reacted with serum IgG from EAO mice. In this study, we identified 11 TGC-specific AIs that reacted with serum from EAO mice. Real-time RT-PCR analysis showed that the mRNA expressions of seven TGC-specific AIs were significantly higher in only mature testis compared to other organs. Moreover, the recombinant proteins of identified 10 (except unnamed protein) TGC-specific AIs were created by using human embryonic kidney 293 (HEK293) cells and these antigencities were reconfirmed by Western blot using EAO serum reaction. These results indicated Atp6v1a, Hsc70t, Fbp1 and Dazap1 were candidates for TGC-specific AIs. Identification of these AIs will facilitate new approaches for understanding infertility and cancer pathogenesis and may provide a basis for the development of novel therapies.

The cancer-retina antigen recoverin as a potential biomarker for renal tumors

The renal cell carcinoma is the ninth most common cancer with an increasing occurrence and mortality. Recoverin is the first retina-specific photoreceptor protein that was shown to undergo aberrant expression, due to its promoter demethylation, as a cancer-retina antigen in a number of malignant tumors. In this work, we demonstrated that recoverin is indeed expressed in 68.4 % of patients with different subtypes of renal cell carcinoma, and this expression has tendency to correlate with tumor size. Interestingly, 91.7 % of patients with the benign renal tumor, oncocytoma, express recoverin as well in their tumor. Epigenetic analysis of the recoverin gene promoter revealed a stable mosaic methylation pattern with the predominance of the methylated state, with the exception of -80 and 56 CpG dinucleotides (CpGs). While the recoverin expression does not correlate withoverall survival of the tumor patients, the methylation of the recoverin gene promoter at -80 position is associated with better overall survival of the patients. This work is the first report pointing towards the association of overall survival of renal cell carcinoma (RCC) patients with promoter methylation of a cancer-retina antigen. Taken together, these data allow to consider recoverin as a potential therapeutic target and/or marker for renal tumors.

The presence of androgen receptor elements regulates ZEB1 expression in the absence of androgen receptor

Zinc finger E-box binding homeobox 1 (ZEB1) is a transcription factor that plays a central role in the epithelial to mesenchymal transition (EMT) of cancer cell lines. Studies on its regulation have mostly focused on the negative 3'UTR binding of miR200c. Interestingly, it has been previously reported that androgen receptor (AR) regulates ZEB1 expression in breast and prostate cancers. In order to validate this, various ZEB1 promoter deletions were cloned into a luciferase reporter system to elucidate the contribution of two putative androgen response elements (AREs). The in vivo contribution of AR was also assessed in cell lines after R1881 treatment using qPCR with prostate specific antigen (PSA) as the positive control. We discovered that AR upregulates the levels of expression of ZEB1 10-fold on a luciferase promoter that only contains the distal ARE. However, when the proximal ARE is included, no additional activation is apparent with AR or its hormone independent variant, AR-V7. Furthermore, we demonstrate here that a promoter construct containing both AREs activates transcription of ZEB1 even in the AR-null cell lines DU145 and PC3. Incubation of the AR-positive cell line, LNCaP with R1881, failed to substantially increase the expression levels of ZEB1. Despite the presence of AREs in the promoter region, it appears that ZEB1 expression can be induced even without AR. In addition, the region around the distal ARE is a potent repressor in AR-null cell lines.

Overexpressed oncogenic tumor-self antigens

Overexpressed tumor-self antigens represent the largest group of candidate vaccine targets. Those exhibiting a role in oncogenesis may be some of the least studied but perhaps most promising. This review considers this subset of self antigens by highlighting vaccine efforts for some of the better known members and focusing on TPD52, a new promising vaccine target. We shed light on the importance of both preclinical and clinical vaccine studies demonstrating that tolerance and autoimmunity (presumed to preclude this class of antigens from vaccine development) can be overcome and do not present the obstacle that might have been expected. The potential of this class of antigens for broad application is considered, possibly in the context of low tumor burden or adjuvant therapy, as is the need to understand mechanisms of tolerance that are relatively understudied.

Clinicopathologic features of plasmablastic lymphoma: Single-center series of 8 cases from Saudi Arabia

BACKGROUND

Plasmablastic lymphoma (PBL) is a rare subtype of non-Hodgkin's lymphoma. Characterized by its aggressive nature and plasmacytic differentiation, PBL remains a therapeutic and diagnostic challenge; it generally has a poor prognosis with very few long-term survivors and most patients dying within 2 years from initial presentation. PBL has been reported in several other countries; however, there have been no reported cases from Saudi Arabia. Here, we report 8 cases of PBL depicting the clinical presentation, immunocompetency, immunphenotypic characterization, diagnostic challenges and treatment outcome.

METHODS

The medical records were reviewed for clinical presentation, staging, laboratory data, radiological studies, treatments, and outcomes. A broad immunohistochemical panel consisting of CD45, CD3, CD20, CD79a, Pax5, CD38, CD138, MUM1, EMA, Kappa, Lambda, CD 56, CD30, Bcl-2, Bcl-6, Alk-1, Ki-67, EBV-LMP-1, and HHV8 was performed.

RESULTS

The tumors predominantly exhibited immunoblastic/plasmablastic or plasmacytic morphologic features and had a plasma cell-like immunophenotype. All cases were immunoreactive for CD38, CD138 and MUM1 confirming plasma cell differentiation of the tumor cells. CD20 was negative for all cases; whereas CD79a and Pax5 were weakly positive in 2cases. All 8 cases were EBV-LMP-1/EBER-1 negative, and 1 case was HHV8 positive. Similar to previously published studies, PBL in Saudi Arabia is characterized by male predominance (6/8), median age 51.5 years (mean age 46 years), associated with early dissemination, poor response to therapy, and limited survival (average survival time, 6.4 months, median overall survival 5.5 months). However, it does have some unique features. It occurs more commonly in immunocompetent persons (6/8, 75%), is not associated with EBV infection (0/8), and nodal involvement (either primary or secondary) is common among patients (6/8). In addition, extra-oral sites are more common than oral/nasal cavities (7/8) and the c-myc gene is not common (1/8, 12.5%).

CONCLUSION

It appears that PBL is heterogeneous in terms of clinical presentation and morphology. PBL is a therapeutic challenge with a clinical course that is characterized by its high rate of relapse and death. To date, treatment responses are usually partial and temporary. Therapies that are more intensive than CHOP do not seem to prolong survival. Further research is needed to understand the biology and molecular pathogenesis of PBL in order to improve therapies.

VIRTUAL SLIDES

The virtual slides for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/1465801416161912.

Cancer-retina antigens -- a new group of tumor antigens

Some photoreceptor proteins normally specific for the eye retina are aberrantly expressed in malignant tumors. These proteins include recoverin, visual rhodopsin, transducin, cGMP-phosphodiesterase 6 (PDE 6), cGMP-dependent cationic channels, guanylyl cyclase 1, rhodopsin kinase, and arrestin. By analogy with cancer-testis antigens, these photoreceptor proteins form the group of cancer-retina antigens. It is shown that an aberrant demethylation of the promoter region of recoverin is involved in the aberrant expression of this protein. The cascade Wnt5a → Frizzled-2 → transducin → PDE 6 is shown to function in skin melanoma cells, and this suggests that these cancer-retina antigens can play a functional role. The events accompanying the signal transduction in this cascade, including those involving calcium ions and cGMP-dependent protein kinase (protein kinase G), are discussed.

Nanowire analysis of cancer-testis antigens as biomarkers of aggressive prostate cancer

OBJECTIVE

To demonstrate the ability of the nCounter Analysis System, a nanowire technology, to sensitively and accurately detect cancer-testis antigens (CTAs) in men with prostate cancer and correlate them with disease parameters. The clinical implementation of novel biomarkers is necessary to provide for individual disease treatment planning for men with prostate cancer. The CTAs, as cancer-associated biomarkers that may correlate with aggressive disease, have the potential to play an important role.

METHODS

Formalin-fixed, paraffin embedded samples were used from men undergoing radical prostatectomy for prostate cancer. The expression of CTAs along with control genes was measured from formalin-fixed, paraffin-embedded prostate cancer tissues using real-time polymerase chain reaction and the nCounter assay.

RESULTS

Using a nanowire-based assay, ribonucleic acid (RNA) expression levels of the CTAs CSAG2 and NOL4 were found to be significantly higher in men with Gleason score (GS) 8-10 disease than those with GS ≤4+3 disease. On the contrary, the RNA expression level of PAGE4 was lower in men with GS 8-10 disease than those with GS ≤6 group. This study demonstrates that CTAs can be detected with a nanostring assay that is translatable and that a set of CTAs correlates with the clinical characteristics of the disease.

CONCLUSION

CTAs represent unique, cancer-associated biomarkers with potential utility in the clinic. The nCounter nanowire technology provides an opportunity to evaluate this panel of CTAs associated with aggressive prostate cancer in a multi-institutional fashion.

Luzp4 defines a new mRNA export pathway in cancer cells

Cancer testis antigens (CTAs) represented a poorly characterized group of proteins whose expression is normally restricted to testis but are frequently up-regulated in cancer cells. Here we show that one CTA, Luzp4, is an mRNA export adaptor. It associates with the TREX mRNA export complex subunit Uap56 and harbours a Uap56 binding motif, conserved in other mRNA export adaptors. Luzp4 binds the principal mRNA export receptor Nxf1, enhances its RNA binding activity and complements Alyref knockdown in vivo. Whilst Luzp4 is up-regulated in a range of tumours, it appears preferentially expressed in melanoma cells where it is required for growth.

XAGE-1b cancer/testis antigen is a potential target for immunotherapy in prostate cancer

INTRODUCTION

Gene-modified cell vaccines are now considered to be the best way to achieve immunotherapy for a variety of cancers including prostate cancer (PCa). XAGE-1b is a member of the cancer/testis antigen family which has demonstrated strong immunogenicity. We investigated whether XAGE-1b is an ideal target for PCa immunotherapy.

MATERIALS AND METHODS

The recombinant eukaryotic expression vector pDisplay-XAGE-1b was constructed. Then the recombinant vector was transfected into Myc-CaP cells and its immunogenicity in vitro was studied. After transfection, the Myc-CaP-XAGE-1b cells were injected into FVB mice subcutaneously. Tumor growth was periodically observed and the anti-tumor effect and mechanism in vivo were further studied.

RESULTS

The recombinant vector was correctly constructed by DNA sequencing and restriction endonuclease digestion. Myc-CaP cells were successfully transfected with XAGE-1b gene by immunofluorescence staining and Western blot. The transfected cells exhibited increased IFN-γ secretion, decreased IL-6 secretion and enhanced killing activity. Tumor grew slower in XAGE-1b-modified FVB mice than in wild-type FVB mice. High dendritic cell expression and low myeloid-derived suppressor cell expression were observed in tumor tissues expressed with XAGE-1b.

CONCLUSIONS

XAGE-1b gene transfection could significantly enhance the immunogenicity of Myc-CaP cells. Therefore, XAGE-1b may be an attractive target for antigen-specific immunotherapy in PCa.

Trial watch: Dendritic cell-based anticancer therapy

The use of patient-derived dendritic cells (DCs) as a means to elicit therapeutically relevant immune responses in cancer patients has been extensively investigated throughout the past decade. In this context, DCs are generally expanded, exposed to autologous tumor cell lysates or loaded with specific tumor-associated antigens (TAAs), and then reintroduced into patients, often in combination with one or more immunostimulatory agents. As an alternative, TAAs are targeted to DCs in vivo by means of monoclonal antibodies, carbohydrate moieties or viral vectors specific for DC receptors. All these approaches have been shown to (re)activate tumor-specific immune responses in mice, often mediating robust therapeutic effects. In 2010, the first DC-based preparation (sipuleucel-T, also known as Provenge®) has been approved by the US Food and Drug Administration (FDA) for use in humans. Reflecting the central position occupied by DCs in the regulation of immunological tolerance and adaptive immunity, the interest in harnessing them for the development of novel immunotherapeutic anticancer regimens remains high. Here, we summarize recent advances in the preclinical and clinical development of DC-based anticancer therapeutics.

Genomic screening of testicular germ cell tumors from monozygotic twins

BACKGROUND

Testicular germ cell tumors (TGCTs) account for 1-2% of all tumors in young and middle aged men. A 75-fold increase in TCGT development has been reported for monozygotic (MZ) twins. Therefore, the occurrence of simultaneous tumors in MZ twins emphasizes the importance of genetic factors that influence the risk of developing these tumors. Genomic screening was performed for one family containing MZ twins with testicular germ cell tumors, in order to define alterations associated with risk of tumor development.

METHODS

Copy number alterations were evaluated using array-CGH (4x44K, Agilent Technologies) in one seminoma and one embryonal carcinoma (EC) from MZ twins. In addition, genomic alterations from the tumors and peripheral blood cells of the twins were compared to the parental genomes via their peripheral blood cells.

RESULTS

Embryonal carcinoma (Twin-1 t) presented a lower frequency of genomic alterations compared to the seminoma (Twin-2 t). One minimal common region of loss was observed in 9p13.1-p12 in the comparison between DNA from blood samples for Twin-1 and Twin-2. In this region is mapped the CNTNAP3 gene which was confirmed as involved in losses by qPCR. Comparative analysis of novel CNVs between the Twin-1 t and Twin-2 t showed five minimal common regions involving gain at chromosomes 12 (12p12.3-p11.1 and 12p13.33-p12.3), while losses were observed at 10p15.3-p15.2, 13q21.1-q21.2 and 15q11.1-q11.2. In addition, one exclusive rare copy number alteration was detected in Twin-1 t and Twin-2 t, and 19 novel alterations were identified in the Twin-2 t.

CONCLUSION

Distinct genomic profiles for MZ twins with phenotypically different TGCT were described. Of particular interest, 12p gains were detected exclusively in tumor samples. In peripheral blood samples, loss of 9p13.1-p12 was the unique novel CNV shared by the twins, confirming the involvement of CNTNAP3 gene in TGCTs development. Although similar CNV profiles were shared by both the peripheral blood and tumor samples of the twins, tumor-specific CNV loci were identified for seminoma and non-seminomatous tumors. These findings suggest the presence of de novo germline structural alterations and TGCT predisposition.

Frequent expression of zinc-finger protein ZNF165 in human urinary bladder transitional cell carcinoma

The aim of the study is to evaluate mRNA/protein expression of zinc finger protein 165 (ZNF165) in transitional cell carcinomas (TCCs) of urinary bladder and correlate its expression with the clinicopathological characteristics of patients. In this study, the methods of quantitative real-time polymerase chain reaction (qRT-PCR) and immunohistochemistry (IHC) were utilized to evaluate mRNA/protein expression of ZNF165 in TCC. Independent Student's t test, ANOVA and Chi-square (χ(2)) were used to analyze the data statistically. We observed overexpression of ZNF165 mRNA in testis and majority (59.2%) of TCC patients. ZNF165 mRNA expression was also detected in adjacent noncancerous tissues (ANCTs) and some other normal tissues. Relative mean fold expression of ZNF165 mRNA was found to be significantly (p<0.01) higher in muscle-invasive bladder cancer (MIBC) as compared to non-muscle-invasive bladder cancer (NMIBC) patients. (12.11±9.57 vs. 5.72±2.61, p=0.009). ZNF165 protein expression was demonstrated on archival formalin-fixed, paraffin-embedded (FFPE) bladder tissues using IHC and nuclear staining pattern was detected. No significant difference was observed in protein expression of ZNF165 between the two groups (NMIBC and MIBC patients) (61.1% vs. 55.2%, p=0.629). No significant protein expression of ZNF165 was observed among ANCTs and benign prostatic hyperplasia (BPH) used as control. Our study results suggest that ZNF165 mRNA/protein expression was observed in TCC of human urinary bladder and might be used as a novel diagnostic biomarker and as well a vaccine target in development of urinary bladder cancer specific immunotherapy.

Expression and clinical significance of cancer-testis genes in clear cell renal cell carcinoma

Cancer-testis (CT) antigens, which are encoded by CT genes, have been recognized as a group of highly attractive targets for cancer immunotherapy. However, the expression and clinical relevance of CT genes in clear cell renal cell carcinoma (ccRCC) remains largely unknown. The present study aims to analyze the expression profile of 6 individual CT genes including MAGE-A1, MAGE-A3, MAGE-A12, cTAGE-1, cTAGE-2, and NY-ESO-1 in ccRCC and further investigate their possible correlations with clinicopathologic characteristics. The mRNA expressions of these CT genes were detected using reverse transcriptase-polymerase chain reaction (RT-PCR) in 105 ccRCC tissue samples (T1-2 in 70 samples, T3-4 in 35 samples; G1-2 in 65 samples, G3-4 in 40 samples) as well as the paired adjacent normal tissues. The most frequently expressed CT gene was MAGE-A3 (27.6%), followed by MAGE-A12 (23.8%), NY-ESO-1 (21%), MAGE-A1 (20%), cTAGE-1 (17.1%), and cTAGE-2 (14.3%). In contrast, no expression of CT genes was detected in the paired adjacent normal tissues. Furthermore, the MAGE-A3 protein expression was determined by Western blot and immunohistochemistry. MAGE-A3 protein was expressed in 21.9% ccRCC samples with a cytoplasmic staining pattern. No MAGE-A3 protein expression was found in the paired adjacent normal tissues. There was a significant correlation between MAGE-A3 expression at both mRNA (P =0.045) and protein (P = 0.03) levels with advanced stages of the disease. Taken together, CT genes may serve as promising targets of specific immunotherapy for ccRCC and particularly, MAGE-A3 may serve as a potential prognostic marker for ccRCC patients.

Cancer/testis antigen PAGE4, a regulator of c-Jun transactivation, is phosphorylated by homeodomain-interacting protein kinase 1, a component of the stress-response pathway

Prostate-associated gene 4 (PAGE4) is a cancer/testis antigen that is typically restricted to the testicular germ cells but is aberrantly expressed in cancer. Furthermore, PAGE4 is developmentally regulated with dynamic expression patterns in the developing prostate and is also a stress-response protein that is upregulated in response to cellular stress. PAGE4 interacts with c-Jun, which is activated by the stress-response kinase JNK1, and plays an important role in the development and pathology of the prostate gland. Here, we have identified homeodomain-interacting protein kinase 1 (HIPK1), also a component of the stress-response pathway, as a kinase that phosphorylates PAGE4 at T51. We show that phosphorylation of PAGE4 is critical for its transcriptional activity since mutating this T residue abolishes its ability to potentiate c-Jun transactivation. In vitro single molecule FRET indicates phosphorylation results in compaction of (still) intrinsically disordered PAGE4. Interestingly, however, while our previous observations indicated that the wild-type nonphosphorylated PAGE4 protein interacted with c-Jun [RajagopalanK. et al. (2014) Biochim, Biophys. Acta1842, 154−16324263171], here we show that phosphorylation of PAGE4 weakens its interaction with c-Jun in vitro. These data suggest that phosphorylation induces conformational changes in natively disordered PAGE4 resulting in its decreased affinity for c-Jun to promote interaction of c-Jun with another, unidentified, partner. Alternatively, phosphorylated PAGE4 may induce transcription of a novel partner, which then potentiates c-Jun transactivation. Regardless, the present results clearly implicate PAGE4 as a component of the stress-response pathway and uncover a novel link between components of this pathway and prostatic development and disease.

Hypomethylation of the CTCFL/BORIS promoter and aberrant expression during endometrial cancer progression suggests a role as an Epi-driver gene

Cancers arise through accumulating genetic and epigenetic alterations, considered relevant for phenotype and approaches to targeting new therapies. We investigated a unique collection of endometrial cancer precursor samples and clinically annotated primary and metastatic lesions for two evolutionary and functionally related transcription factors, CCCTC-binding factor (zinc finger protein) (CTCF) and its paralogue CTCF-like factor, also denoted Brother of the Regulator of Imprinted Sites (CTCFL/BORIS). CTCF, a chromatin modeling- and transcription factor, is normally expressed in a ubiquitous fashion, while CTCFL/BORIS is restricted to the testis. In cancer, CTCF is thought to be a tumor suppressor, while CTCFL/BORIS has been suggested as an oncogene. CTCF mutations were identified in 13%, with CTCF hotspot frameshift mutations at p.T204, all observed solely in the endometrioid subtype, but with no association with outcome. Interestingly, CTCFL/BORIS was amongst the top ranked genes differentially expressed between endometrioid and non-endometrioid tumors, and increasing mRNA level of CTCFL/BORIS was highly significantly associated with poor survival. As aberrant CTCFL/BORIS expression might relate to loss of methylation, we explored methylation status in clinical samples from complex atypical hyperplasia, through primary tumors to metastatic lesions, demonstrating a pattern of DNA methylation loss during disease development and progression in line with the increase in CTCFL/BORIS mRNA expression observed. Thus, CTCF and CTCFL/BORIS are found to diverge in the different subtypes of endometrial cancer, with CTCFL/BORIS activation through demethylation from precursors to metastatic lesions. We thus propose, CTCFL/BORIS as an Epi-driver gene in endometrial cancer, suggesting a potential for future vaccine development.

The Stress-response protein prostate-associated gene 4, interacts with c-Jun and potentiates its transactivation

The Cancer/Testis Antigen (CTA), Prostate-associated Gene 4 (PAGE4), is a stress-response protein that is upregulated in prostate cancer (PCa) especially in precursor lesions that result from inflammatory stress. In cells under stress, translocation of PAGE4 to mitochondria increases while production of reactive oxygen species decreases. Furthermore, PAGE4 is also upregulated in human fetal prostate, underscoring its potential role in development. However, the proteins that interact with PAGE4 and the mechanisms underlying its pleiotropic functions in prostatic development and disease remain unknown. Here, we identified c-Jun as a PAGE4 interacting partner. We show that both PAGE4 and c-Jun are overexpressed in the human fetal prostate; and in cell-based assays, PAGE4 robustly potentiates c-Jun transactivation. Single-molecule Förster resonance energy transfer experiments indicate that upon binding to c-Jun, PAGE4 undergoes conformational changes. However, no interaction is observed in presence of BSA or unilamellar vesicles containing the mitochondrial inner membrane diphosphatidylglycerol lipid marker cardiolipin. Together, our data indicate that PAGE4 specifically interacts with c-Jun and that, conformational dynamics may account for its observed pleiotropic functions. To our knowledge, this is the first report demonstrating crosstalk between a CTA and a proto-oncogene. Disrupting PAGE4/c-Jun interactions using small molecules may represent a novel therapeutic strategy for PCa.

Expression screening of cancer/testis genes in prostate cancer identifies NR6A1 as a novel marker of disease progression and aggressiveness

BACKGROUND

Cancer/Testis (CT) genes are expressed in male gonads, repressed in most healthy somatic tissues and de-repressed in various somatic malignancies including prostate cancers (PCa). Because of their specific expression signature and their associations with tumor aggressiveness and poor outcomes, CT genes are considered to be useful biomarkers and they are also targets for the development of new anti-cancer immunotherapies. The aim of this study was to identify novel CT genes associated with hormone-sensitive prostate cancer (HSPC), and castration-resistant prostate cancer (CRPC).

METHODS

To identify novel CT genes we screened genes for which transcripts were detected by RNA profiling specifically in normal testis and in either HSPC or CRPC as compared to normal prostate and 44 other healthy tissues using GeneChips. The expression and clinicopathological significance of a promising candidate--NR6A1--was examined in HSPC, CRPC, and metastatic site samples using tissue microarrays.

RESULTS

We report the identification of 98 genes detected in CRPC, HSPC and testicular samples but not in the normal controls. Among them, cellular levels of NR6A1 were found to be higher in HSPC compared to normal prostate and further increased in metastatic lesions and CRPC. Furthermore, increased NR6A1 immunoreactivity was significantly associated with a high Gleason score, advanced pT stage and cancer cell proliferation.

CONCLUSIONS

Our results show that cellular levels of NR6A1 are correlated with disease progression in PCa. We suggest that this essential orphan nuclear receptor is a potential therapeutic target as well as a biomarker of PCa aggressiveness.

CETN1 is a cancer testis antigen with expression in prostate and pancreatic cancers

BACKGROUND

The Cancer Testis Antigens (CTAs) are a group of genes that are highly expressed in the normal testis and several types of cancer. Due to their restricted expression in normal adult tissues, CTAs have been attractive targets for immunotherapy and biomarker development. In this work, we discovered that Centrin 1 (CETN1) which is found in the centrosome of all eukaryotes, may be a member of this group and is highly expressed in prostate and pancreatic cancer. Three members of the centrin family of calcium binding proteins (CETN) are localized to the centrosome in all eukaryotes with CDC31 being the sole yeast homolog. CETN1 is a retrogene that probably arose from a retrotransposition of CETN2, an X-linked gene. A previous mouse study shows that CETN1 is expressed solely in the testis, while CETN2 is expressed in all organs.

RESULTS

In this work, we show that CETN1 is a new member of the growing group of CTAs. Through the mining of publicly available microarray data, we discovered that human CETN1 expression but not CETN2 or CETN3 is restricted to the testis. In fact, CETN1 is actually down-regulated in testicular malignancies compared to normal testis. Using q-PCR, CETN1 expression is shown to be highly up-regulated in cancer of the prostate and in pancreatic xenografts. Unexpectedly however, CETN1 expression was virtually absent in various cell lines until they were treated with the DNA demethylation agent 5'AZA-2'Deoxycytidine (AZA) but showed no increased expression upon incubation with Histone deacetylase inhibitor Trichostatin-A (TSA) alone. Additionally, like most CTAs, CETN1 appears to be an intrinsically disordered protein which implies that it may occupy a hub position in key protein interaction networks in cancer. Neither CETN1 nor CETN2 could compensate for loss of CDC31 expression in yeast which is analogous to published data for CETN3.

CONCLUSIONS

This work suggests that CETN1 is a novel CTA with expression in cancer of the prostate and pancreas. In cell lines, the expression is probably regulated by promoter methylation, while the method of regulation in normal adult tissues remains unknown.