The novel cancer-testis antigen A-kinase anchor protein 4 (AKAP4) is a potential target for immunotherapy of ovarian serous carcinoma

Assessing the 9G Technology Blood Test for Predicting Lung Cancer in Patients with CT-Detected Lung Nodules: A Multicenter Clinical Trial

Background and Objectives: Lung nodules detected by chest computed tomography (CT) often require invasive biopsies for definitive diagnosis, leading to unnecessary procedures for benign lesions. A blood-based biomarker test that predicts lung cancer risk in CT-detected nodules could help stratify patients and direct invasive diagnostics toward high-risk individuals. Methods: In this multicenter, single-blinded clinical trial, we evaluated a test measuring plasma levels of p53, anti-p53 autoantibodies, CYFRA 21-1, and anti-CYFRA 21-1 autoantibodies in patients with CT-detected lung nodules. Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were calculated, and subgroup analyses by gender, age, and smoking status were performed. A total of 1132 patients who had CT-detected lung nodules, including 885 lung cancer cases and 247 benign lesions, were enrolled from two academic hospitals in South Korea. Results: The test demonstrated a sensitivity of 78.4% (95% CI: 75.7-81.1) and specificity of 93.1% (95% CI: 90.0-96.3) in predicting lung cancer in CT-detected nodules. The PPV was 97.6%, and the NPV was 54.6%. Performance was consistent across gender (sensitivity 79.3% in men and 76.8% in women) and age groups, with a specificity of 93.4% in men and 92.7% in women. Stage I lung cancer was detected with a sensitivity of 80.6%. Conclusions: The Lung Cancer test based on 9G technology presented here offers a non-invasive method for stratifying lung cancer risk in patients with CT-detected nodules. Its integration into clinical practice could reduce unnecessary interventions and foster earlier detection.

The potential value of cancer-testis antigens in ovarian cancer: Prognostic markers and targets for immunotherapy

BACKGROUND

Tumor immunotherapy has become an important adjuvant therapy after surgery, radiotherapy, and chemotherapy. In recent years, the role of tumor-associated antigen (TAA) in tumor immunotherapy has become increasingly prominent. Cancer-testis antigen (CTA) is a kind of TAA that is highly restricted in a variety of tumors and can induce an immune response.

AIMS

This review article aimed to evaluate the role of CTA on the progression of ovarian cancer, its diagnostic efficacy, and the potential for immunotherapy.

METHODS

We analyzed publications and outlined a comprehensive of overview the regulatory mechanism, immunogenicity, clinical expression significance, tumorigenesis, and application prospects of CTA in ovarian cancer, with a particular focus on recent progress in CTA-based immunotherapy.

RESULTS

The expression of CTA affects the occurrence, development, and prognosis of ovarian cancer and is closely related to tumor immunity.

CONCLUSION

CTA can be used as a biomarker for the diagnosis and prognosis evaluation of ovarian cancer and is an ideal target for antitumor immunotherapy. These findings provide novel insights on CTA in the improvement of diagnosis and treatment for ovarian cancer. The successes, current challenges and future prospects were also discussed to portray its significant potential.

cAMP-Dependent Signaling and Ovarian Cancer

cAMP-dependent pathway is one of the most significant signaling cascades in healthy and neoplastic ovarian cells. Working through its major effector proteins-PKA and EPAC-it regulates gene expression and many cellular functions. PKA promotes the phosphorylation of cAMP response element-binding protein (CREB) which mediates gene transcription, cell migration, mitochondrial homeostasis, cell proliferation, and death. EPAC, on the other hand, is involved in cell adhesion, binding, differentiation, and interaction between cell junctions. Ovarian cancer growth and metabolism largely depend on changes in the signal processing of the cAMP-PKA-CREB axis, often associated with neoplastic transformation, metastasis, proliferation, and inhibition of apoptosis. In addition, the intracellular level of cAMP also determines the course of other pathways including AKT, ERK, MAPK, and mTOR, that are hypo- or hyperactivated among patients with ovarian neoplasm. With this review, we summarize the current findings on cAMP signaling in the ovary and its association with carcinogenesis, multiplication, metastasis, and survival of cancer cells. Additionally, we indicate that targeting particular stages of cAMP-dependent processes might provide promising therapeutic opportunities for the effective management of patients with ovarian cancer.

Nucleic acid vaccination strategies for ovarian cancer

High grade serous carcinoma (HGSC) is one of the most lethal ovarian cancers that is characterised by asymptomatic tumour growth, insufficient knowledge of malignant cell origin and sub-optimal detection. HGSC has been recently shown to originate in the fallopian tube and not in the ovaries. Conventional treatments such as chemotherapy and surgery depend upon the stage of the disease and have resulted in higher rates of relapse. Hence, there is a need for alternative treatments. Differential antigen expression levels have been utilised for early detection of the cancer and could be employed in vaccination strategies using nucleic acids. In this review the different vaccination strategies in Ovarian cancer are discussed and reviewed. Nucleic acid vaccination strategies have been proven to produce a higher CD8+ CTL response alongside CD4+ T-cell response when compared to other vaccination strategies and thus provide a good arena for antitumour immune therapy. DNA and mRNA need to be delivered into the intracellular matrix. To overcome ineffective naked delivery of the nucleic acid cargo, a suitable delivery system is required. This review also considers the suitability of cell penetrating peptides as a tool for nucleic acid vaccine delivery in ovarian cancer.

Silencing of A-kinase anchor protein 4 inhibits the metastasis and growth of non-small cell lung cancer

Non-small cell lung cancer (NSCLC) is one of the most malignant tumors. The treatment of advanced NSCLC can be challenging due to drug resistance. The discovery of novel cancer-testis antigens to develop new strategies for advanced metastatic NSCLC is required. AKAP4 is an oncogene discovered in some malignant tumors, and its molecular function of AKAP4 in NSCLC is unknown. This study aimed to explore the potential function of AKAP4 in the development and progression of NSCLC. AKAP-4 was found to be significantly upregulated in both clinical NSCLC tissues and NSCLC cell lines. Cell viability and migration were suppressed, apoptosis was induced, and tube formation was inhibited by the knockdown of AKAP-4, accompanied by the downregulation of VEGF, N-cadherin, EphA2, and MMP-2, and upregulation of c-AMP, PKA, and E-cadherin. In vivo xenograft experiments revealed that tumor growth was inhibited by the knockdown of AKAP4, accompanied by the activation of c-AMP/PKA signaling and inhibition of epithelial-mesenchymal transition progression. Our results show that AKAP4 might be an important target for treating NSCLC because of its function in promoting the migration and proliferation of NSCLC cells.

Targeted biologic inhibition of both tumor cell-intrinsic and intercellular CLPTM1L/CRR9-mediated chemotherapeutic drug resistance

Recurrence of therapy-resistant tumors is a principal problem in solid tumor oncology, particularly in ovarian cancer. Despite common complete responses to first line, platinum-based therapies, most women with ovarian cancer recur, and eventually, nearly all with recurrent disease develop platinum resistance. Likewise, both intrinsic and acquired resistance contribute to the dismal prognosis of pancreatic cancer. Our previous work and that of others has established CLPTM1L (cleft lip and palate transmembrane protein 1-like)/CRR9 (cisplatin resistance related protein 9) as a cytoprotective oncofetal protein that is present on the tumor cell surface. We show that CLPTM1L is broadly overexpressed and accumulated on the plasma membrane of ovarian tumor cells, while weakly or not expressed in normal tissues. High expression of CLPTM1L is associated with poor outcome in ovarian serous adenocarcinoma. Robust re-sensitization of resistant ovarian cancer cells to platinum-based therapy was achieved using human monoclonal biologics inhibiting CLPTM1L in both orthotopic isografts and patient-derived cisplatin resistant xenograft models. Furthermore, we demonstrate that in addition to cell-autonomous cytoprotection by CLPTM1L, extracellular CLPTM1L confers resistance to chemotherapeutic killing in an ectodomain-dependent fashion, and that this intercellular resistance mechanism is inhibited by anti-CLPTM1L biologics. Specifically, exosomal CLPTM1L from cisplatin-resistant ovarian carcinoma cell lines conferred resistance to cisplatin in drug-sensitive parental cell lines. CLPTM1L is present in extracellular vesicle fractions of tumor culture supernatants and in patients' serum with increasing abundance upon chemotherapy treatment. These findings have encouraging implications for the use of anti-CLPTM1L targeted biologics in the treatment of therapy-resistant tumors.

TRIP13 promotes metastasis of colorectal cancer regardless of p53 and microsatellite instability status

Overexpression of TRIP13, a member of the AAA-ATPase family, is linked with various cancers, but its role in metastasis is unknown in colorectal cancer (CRC). In the current study, we investigated the role TRIP13 in experimental metastasis and its involvement in regulation of WNT/β-catenin and EGFR signaling pathways. Evaluation of formalin-fixed paraffin-embedded (FFPE) and frozen tissues of adenomas and CRCs, along with their corresponding normal samples, showed that TRIP13 was gradually increased in its phenotypic expression from adenoma to carcinoma and that its overexpression in CRCs was independent of patient's gender, age, race/ethnicity, pathologic stage, and p53 and microsatellite instability (MSI) status. Moreover, liver metastases of CRCs showed TRIP13 overexpression as compared to matched adjacent liver tissues, indicating the biological relevance of TRIP13 in CRC progression and metastasis. TRIP13 knockdown impeded colony formation, invasion, motility, and spheroid-forming capacity of CRC cells irrespective of their p53 and MSI status. Furthermore, xenograft studies demonstrated high expression of TRIP13 contributed to tumor growth and metastasis. Depletion of TRIP13 in CRC cells decreased metastasis and it was independent of the p53 and MSI status. Furthermore, TRIP13 interacted with a tyrosine kinase, FGFR4; this interaction could be essential for activation of the EGFR-AKT pathway. In addition, we demonstrated the involvement of TRIP13 in the Wnt signaling pathway and in the epithelial-mesenchymal transition. Cell-based assays revealed that miR-192 and PNPT1 regulate TRIP13 expression in CRC. Additionally, RNA sequencing of CRC cells with TRIP13 knockdown identified COL6A3, TREM2, SHC3, and KLK7 as downstream targets that may have functional relevance in TRIP13-mediated tumor growth and metastasis. In summary, our results demonstrated that TRIP13 promotes tumor growth and metastasis regardless of p53 and MSI status, and indicated that it is a target for therapy of CRC.

9G TestTM Cancer/Lung: A Desirable Companion to LDCT for Lung Cancer Screening

Simple Summary

Lung cancer is the most common cause of cancer-related deaths globally. Patients diagnosed at early-stage (0–I) have a higher survival rate than the metastasized stages (III–IV). Thus, there is great potential to reduce mortality by diagnosing lung cancer at stage 0~I through community screening. LDCT is a promising method, but it has a high false-positive rate. Therefore, a biomarker test that can be used in combination with LDCT for lung cancer screening to reduce false-positive rates is highly awaited. The present study evaluated the applicability of 9G test^TM Cancer/Lung test to detect stage 0~IV lung cancer. 9G test^TM Cancer/Lung test detects stage I, stage II, stage III, and stage IV cancers with the sensitivities of 77.5%, 78.1%, 67.4%, and 33.3%, respectively, at the specificity of 97.3%. These results indicate that the 9G test^TM Cancer/Lung can be used in conjunction with LDCT to screen lung cancer.

Abstract

A complimentary biomarker test that can be used in combination with LDCT for lung cancer screening is highly desirable to improve the diagnostic capacity of LDCT and reduce the false-positive rates. Most importantly, the stage I lung cancer detection rate can be dramatically increased by the simultaneous use of a biomarker test with LDCT. The present study was conducted to evaluate 9G test^TM Cancer/Lung’s sensitivity and specificity in detecting Stage 0~IV lung cancer. The obtained results indicate that the 9G test^TM Cancer/Lung can detect lung cancer with overall sensitivity and specificity of 75.0% (69.1~80.3) and 97.3% (95.0~98.8), respectively. The detection of stage I, stage II, stage III, and stage IV cancers with sensitivities of 77.5%, 78.1%, 67.4%, and 33.3%, respectively, at the specificity of 97.3% have never been reported before. The receiver operating characteristic curve analysis allowed us to determine the population-weighted AUC of 0.93 (95% CI, 0.91–0.95). These results indicate that the 9G test^TM Cancer/Lung can be used in conjunction with LDCT to screen lung cancer. Furthermore, obtained results indicate that the use of 9G test^TM Cancer/Lung with LDCT for lung cancer screening can increase stage I cancer detection, which is crucial to improve the currently low 5-year survival rates.

PAICS, a De Novo Purine Biosynthetic Enzyme, Is Overexpressed in Pancreatic Cancer and Is Involved in Its Progression

Pancreatic ductal adenocarcinoma (PDAC) is an aggressive cancer with an extremely poor prognosis. There is an urgent need to identify new therapeutic targets and also understand the mechanism of PDAC progression that leads to aggressiveness of the disease. To find therapeutic targets, we analyzed data related to PDAC transcriptome sequencing and found overexpression of the de novo purine metabolic enzyme phosphoribosylaminoimidazole succinocarboxamide synthetase (PAICS). Immunohistochemical analysis of PDAC tissues showed high expression of the PAICS protein. To assess the biological roles of PAICS, we used RNA interference and knock down of its expression in PDAC cell lines that caused a reduction in PDAC cell proliferation and invasion. Furthermore, results of chorioallantoic membrane assays and pancreatic cancer xenografts demonstrated that PAICS regulated pancreatic tumor growth. Our data also showed that, in PDAC cells, microRNA-128 regulates and targets PAICS. PAICS depletion in PDAC cells caused upregulation in E-cadherin, a marker of the epithelial-mesenchymal transition. In PDAC cells, a BET inhibitor, JQ1, reduced PAICS expression. Thus, our investigations show that PAICS is a therapeutic target for PDAC and, as an enzyme, is amenable to targeting by small molecules.

PAICS, a Purine Nucleotide Metabolic Enzyme, is Involved in Tumor Growth and the Metastasis of Colorectal Cancer

The identification of colorectal cancer (CRC) molecular targets is needed for the development of drugs that improve patient survival. We investigated the functional role of phosphoribosylaminoimidazole carboxylase, phosphoribosylaminoimidazole succinocarboxamide synthetase (PAICS), a de novo purine biosynthetic enzyme involved in DNA synthesis, in CRC progression and metastasis by using cell and animal models. Its clinical utility was assessed in human CRC samples. The expression of PAICS was regulated by miR-128 and transcriptionally activated by Myc in CRC cells. Increased expression of PAICS was involved in proliferation, migration, growth, and invasion of CRC cells irrespective of the p53 and microsatellite status. In mice, the depletion of PAICS in CRC cells led to reduced tumor growth and metastatic cell dissemination to the liver, lungs, and bone. Positron emission tomography imaging showed significantly reduced metastatic lesions in stable PAICS knockdown CRC cells. In cells with PAICS knockdown, there was upregulation of the epithelial mesenchymal transition marker, E-cadherin, and bromodomain inhibitor, JQ1, can target its increased expression by blocking Myc. PAICS was overexpressed in 70% of CRCs, and was associated with poor 5-year survival independent of the pathologic stage, patient’s race, gender, and age. Overall, the findings point to the usefulness of PAICS targeting in the treatment of aggressive colorectal cancer.

Targeting P4HA1 with a Small Molecule Inhibitor in a Colorectal Cancer PDX Model

Deposition, remodeling, and signaling of the extracellular matrix facilitate tumor growth and metastasis. Here, we demonstrated that an enzyme, collagen prolyl 4-hydroxylase, alpha polypeptide I (P4HA1), which is involved in collagen synthesis and deposition, had elevated expression in colorectal cancers (CRCs) as compared to normal colonic tissues. The expression of P4HA1 in CRCs was independent of patient's age, race/ethnicity, gender, pathologic stage and grade, tumor location, and microsatellite instability (MSI) and p53 status. By modulating P4HA1 with shRNA, there was a reduction in malignant phenotypes of CRCs, including cell proliferation, colony formation, invasion, migration, and tumor growth, in mice regardless of their p53 and MSI status. Immunoblot analysis of excised xenograft tumors developed from cells with silenced PH4HA1 showed low levels of proliferating cell nuclear antigen. Further, in CRC mouse models, silencing of P4HA1 in HT29 cells resulted in less metastasis to liver and bone. P4HA1 expression was regulated by miR-124, and inhibition of cell growth was noted for CRC cells treated with miR-124. Furthermore, low levels of the transcriptional repressor EZH2 reduced P4HA1 expression in CRC cells. Inhibition of P4HA1 with the small molecule inhibitor diethyl-pythiDC decreased AGO2 and MMP1, which are P4HA1 target molecules, and reduced the malignant phenotypes of CRC cells. Treatment of CRC patient-derived xenografts that exhibit high expression of P4HA1 with diethyl-pythiDC resulted in tumor regression. Thus, the present study shows that P4HA1 contributes to CRC progression and metastasis and that targeting of P4HA1 with diethyl-pythiDC could be an effective therapeutic strategy for aggressive CRCs.

Cell Type-Specific Expression of Testis Elevated Genes Based on Transcriptomics and Antibody-Based Proteomics

One of the most complex organs in the human body is the testis, where spermatogenesis takes place. This physiological process involves thousands of genes and proteins that are activated and repressed, making testis the organ with the highest number of tissue-specific genes. However, the function of a large proportion of the corresponding proteins remains unknown and testis harbors many missing proteins (MPs), defined as products of protein-coding genes that lack experimental mass spectrometry evidence. Here, an integrated omics approach was used for exploring the cell type-specific protein expression of genes with an elevated expression in testis. By combining genome-wide transcriptomics analysis with immunohistochemistry, more than 500 proteins with distinct testicular protein expression patterns were identified, and these were selected for in-depth characterization of their in situ expression in eight different testicular cell types. The cell type-specific protein expression patterns allowed us to identify six distinct clusters of expression at different stages of spermatogenesis. The analysis highlighted numerous poorly characterized proteins in each of these clusters whose expression overlapped with that of known proteins involved in spermatogenesis, including 85 proteins with an unknown function and 60 proteins that previously have been classified as MPs. Furthermore, we were able to characterize the in situ distribution of several proteins that previously lacked spatial information and cell type-specific expression within the testis. The testis elevated expression levels both at the RNA and protein levels suggest that these proteins are related to testis-specific functions. In summary, the study demonstrates the power of combining genome-wide transcriptomics analysis with antibody-based protein profiling to explore the cell type-specific expression of both well-known proteins and MPs. The analyzed proteins constitute important targets for further testis-specific research in male reproductive disorders.

Comprehensive characterization of cancer-testis genes in testicular germ cell tumor

Cancer-testis (CT) genes are a group of genes restrictedly expressed in testis and multiple cancers and can serve as candidate driver genes participating in the development of cancers. Our previous study identified a number of CT genes in nongerm cell tumors, but their expression pattern in testicular germ cell tumor (TGCT), a cancer type characterized by less genomic alterations, remained largely unknown. In this study, we systematically investigated the expression pattern of CT genes in TGCT samples and evaluated the transcriptome difference between TGCT and normal testis tissues, using datasets from the UCSC Xena platform, The Cancer Genome Atlas (TCGA) and the Genotype-Tissue Expression (GTEx) project. Pathway enrichment analysis and survival analysis were conducted to evaluate the biological function and prognostic effect of expressed CT genes. We identified that 1036 testis-specific expressed protein-coding genes and 863 testis-specific expressed long noncoding RNAs (lncRNAs) were expressed in TGCT samples, including 883 CT protein-coding genes and 710 CT lncRNAs defined previously. The number of expressed CT genes was significantly higher in seminomas (P = 3.48 × 10-13 ) which were characterized by frequent mutations in driver genes (KIT, KRAS and NRAS). In contrast, the number of expressed CT genes showed a moderate negative correlation with the fraction of copy number altered genomes (cor = -0.28, P = 1.20 × 10-3 ). Unlike other cancers, our analysis revealed that 96.16% of the CT genes were down-regulated in TGCT samples, while CT genes in stem cell maintenance related pathways were up-regulated. Further survival analysis provided evidence that CT genes could also predict the prognosis of TGCT patients with both disease-free interval and progression-free interval as clinical endpoints. Taken together, our study provided a global view of CT genes in TGCT and provided evidence that CT genes played important roles in the progression and maintenance of TGCT.

Cancer-testis antigens in ovarian cancer: implication for biomarkers and therapeutic targets

Ovarian cancer remains the most fatal gynecologic malignancy worldwide due to delayed diagnosis as well as recurrence and drug resistance. Thus, the development of new tumor-related molecules with high sensitivity and specificity to replace or supplement existing tools is urgently needed. Cancer-testis antigens (CTAs) are exclusively expressed in normal testis tissues but abundantly found in several types of cancers, including ovarian cancer. Numerous novel CTAs have been identified by high-throughput sequencing techniques, and some aberrantly expressed CTAs are associated with ovarian cancer initiation, clinical outcomes and chemotherapy resistance. More importantly, CTAs are immunogenic and may be novel targets for antigen-specific immunotherapy in ovarian cancer. In this review, we attempt to characterize the expression of candidate CTAs in ovarian cancer and their clinical significance as biomarkers, activation mechanisms, function in malignant phenotypes and applications in immunotherapy.

Quantification of CYFRA 21-1 and a CYFRA 21-1–anti-CYFRA 21-1 autoantibody immune complex for detection of early stage lung cancer

Population-based screening of stage 0–I lung cancer is crucial for saving lives. The CIC/CYFRA 21-1 ratio allows the detection of stage I lung cancer with 76.0% sensitivity and 87.5% specificity.

The potential immune-eliciting cancer testis antigens in colorectal cancer

The identification of cancer testis antigens (CTAs) has been an important finding in the search of potential targets for cancer immunotherapy. CTA is one of the subfamilies of the large tumor-associated antigens groups. It is aberrantly expressed in various types of human tumors but is absent in normal tissues except for the testis and placenta. This CTAs-restricted pattern of expression in human malignancies together with its potential immunogenic properties, has stirred the interest of many researchers to use CTAs as one of the ideal targets in cancer immunotherapy. To date, multiple studies have shown that CTAs-based vaccines can elicit clinical and immunological responses in different tumors, including colorectal cancer (CRC). This review details our current understanding of CTAs and CRC in regard to the expression and immunological responses as well as some of the critical hurdles in CTAs-based immunotherapy.

The Tumor Microenvironment of Epithelial Ovarian Cancer and Its Influence on Response to Immunotherapy

Immunotherapy as a treatment for cancer is a growing field of endeavor but reports of success have been limited for epithelial ovarian cancer. Overcoming the challenges to developing more effective therapeutic approaches lies in a better understanding of the factors in cancer cells and the surrounding tumor microenvironment that limit response to immunotherapies. This article provides an overview of some ovarian cancer cell features such as tumor-associated antigens, ovarian cancer-derived exosomes, tumor mutational burden and overexpression of immunoinhibitory molecules. Moreover, we describe relevant cell types found in epithelial ovarian tumors including immune cells (T and B lymphocytes, Tregs, NK cells, TAMs, MDSCs) and other components found in the tumor microenvironment including fibroblasts and the adipocytes in the omentum. We focus on how those components may influence responses to standard treatments or immunotherapies.

The Tumor Microenvironment of Epithelial Ovarian Cancer and Its Influence on Response to Immunotherapy

Immunotherapy as a treatment for cancer is a growing field of endeavor but reports of success have been limited for epithelial ovarian cancer. Overcoming the challenges to developing more effective therapeutic approaches lies in a better understanding of the factors in cancer cells and the surrounding tumor microenvironment that limit response to immunotherapies. This article provides an overview of some ovarian cancer cell features such as tumor-associated antigens, ovarian cancer-derived exosomes, tumor mutational burden and overexpression of immunoinhibitory molecules. Moreover, we describe relevant cell types found in epithelial ovarian tumors including immune cells (T and B lymphocytes, Tregs, NK cells, TAMs, MDSCs) and other components found in the tumor microenvironment including fibroblasts and the adipocytes in the omentum. We focus on how those components may influence responses to standard treatments or immunotherapies.

The Tumor Microenvironment of Epithelial Ovarian Cancer and Its Influence on Response to Immunotherapy

Immunotherapy as a treatment for cancer is a growing field of endeavor but reports of success have been limited for epithelial ovarian cancer. Overcoming the challenges to developing more effective therapeutic approaches lies in a better understanding of the factors in cancer cells and the surrounding tumor microenvironment that limit response to immunotherapies. This article provides an overview of some ovarian cancer cell features such as tumor-associated antigens, ovarian cancer-derived exosomes, tumor mutational burden and overexpression of immunoinhibitory molecules. Moreover, we describe relevant cell types found in epithelial ovarian tumors including immune cells (T and B lymphocytes, Tregs, NK cells, TAMs, MDSCs) and other components found in the tumor microenvironment including fibroblasts and the adipocytes in the omentum. We focus on how those components may influence responses to standard treatments or immunotherapies.

AKAP4, SPAG9 and NY-ESO-1 in Iranian Colorectal Cancer Patients as Probable Diagnostic and Prognostic Biomarkers

Background and objectives:

Colorectal cancer (CRC) is the most common gastrointestinal cancer and the second leading cause of cancer death in women in the world. Cancer-Testis Antigens (CTAs) are a group of tumor-associated proteins which typically are expressed in normal reproductive cells of men, but their expression in normal somatic cells is silenced. CTAs, due to their limited expression pattern, are considered as promising targets for cancer diagnosis and immuno-therapy.

Methods:

Expression of AKAP4, SPAG9 and CTAG1B genes from the CTAs family was studied in both tumor and normal tissues of 62 Iranian CRC patients by RT-PCR with the aim of finding biomarkers for early detection and anticipated progression. Statistical analysis was performed SPSS software V22.0 to assess the significance of any associations.

Results:

Elevated expression of SPAG9 and AKAP4 genes was observed in approximately 66% and 44% of tumours, respectively, as compared to adjacent non-cancerous tissues. While a significant association was found between AKAP4 gene expression and metastasis (P-value: 0.045), expression of the CTAG1B (NY-ESO-1) gene was not observed in our cases.

Conclusion:

AKAP4 and SPAG9 genes may find use as diagnostic biomarkers for CRC and AKAP4 may play an important role in progression to metastasis.

RNA-based ovarian cancer research from 'a gene to systems biomedicine' perspective

Ovarian cancer remains the leading cause of death from a gynecologic malignancy, and treatment of this disease is harder than any other type of female reproductive cancer. Improvements in the diagnosis and development of novel and effective treatment strategies for complex pathophysiologies, such as ovarian cancer, require a better understanding of disease emergence and mechanisms of progression through systems medicine approaches. RNA-level analyses generate new information that can help in understanding the mechanisms behind disease pathogenesis, to identify new biomarkers and therapeutic targets and in new drug discovery. Whole RNA sequencing and coding and non-coding RNA expression array datasets have shed light on the mechanisms underlying disease progression and have identified mRNAs, miRNAs, and lncRNAs involved in ovarian cancer progression. In addition, the results from these analyses indicate that various signalling pathways and biological processes are associated with ovarian cancer. Here, we present a comprehensive literature review on RNA-based ovarian cancer research and highlight the benefits of integrative approaches within the systems biomedicine concept for future ovarian cancer research. We invite the ovarian cancer and systems biomedicine research fields to join forces to achieve the interdisciplinary caliber and rigor required to find real-life solutions to common, devastating, and complex diseases such as ovarian cancer.

ABBREVIATIONS

CAF: cancer-associated fibroblasts; COG: Cluster of Orthologous Groups; DEA: disease enrichment analysis; EOC: epithelial ovarian carcinoma; ESCC: oesophageal squamous cell carcinoma; GSI: gamma secretase inhibitor; GO: Gene Ontology; GSEA: gene set enrichment analyzes; HAS: Hungarian Academy of Sciences; lncRNAs: long non-coding RNAs; MAPK/ERK: mitogen-activated protein kinase/extracellular signal-regulated kinases; NGS: next-generation sequencing; ncRNAs: non-coding RNAs; OvC: ovarian cancer; PI3K/Akt/mTOR: phosphatidylinositol-3-kinase/protein kinase B/mammalian target of rapamycin; RT-PCR: real-time polymerase chain reaction; SNP: single nucleotide polymorphism; TF: transcription factor; TGF-β: transforming growth factor-β.

Heat shock protein 70-2 (HSP70-2) a novel cancer testis antigen that promotes growth of ovarian cancer

Heat shock protein 70-2 (HSP70-2) is known to be involved in tumor progression. However, its molecular role and mechanism in epithelial ovarian cancer (EOC) remains unknown. In the present investigation, we examined the role of HSP70-2 in cell cycle, apoptosis and epithelial mesenchymal transition pathways in EOC cells in in vitro and in-vivo xenograft mouse model. To investigate the role of HSP70-2 in ovarian cancer, plasmid driven short hairpin RNA approach was used to examine HSP70-2 gene and protein expression in ovarian cancer cell line A-10 (origin: serous papillary cystadenocarcinoma), Caov-3 (origin: adenocarcinoma) and SKOV3 (origin: adenocarcinoma; derived from metastatic site: ascites) by RT-PCR, quantitative-PCR, immunohistochemistry and Western blotting. Light microscopy, scanning electron microscopy, viability tests, and flow cytometry were used to study the cellular proliferation, onset of senescence, colony forming ability and morphological features of cancer cells. Cell migration and invasion ability was evaluated by wound healing and Boyden chamber assays. Further, we studied the effect of HSP70-2 protein ablation on human ovarian xenograft mice model. At molecular level, various molecules involved in apoptosis, cell cycle and epithelial-mesenchymal-transition were also examined both in in-vitro and in-vivo xenograft mouse model. The knockdown of HSP70-2 expression by gene silencing resulted in the onset of apoptosis, senescence, reduced cellular growth and colony forming ability of EOC cells. Interestingly, the migration, invasion and wound healing abilities of cells were also significantly inhibited. In addition, the ablation of HSP70-2 resulted in the upregulation of cytochrome-C, caspase 3, caspase 7, caspase 9, APAF1, BAX, BIM, BAK, BAD, BID, PUMA, NOXA, p16, p21, Rb, E-cadherin, cytokeratin 18, EMA in these cells as well as in the xenograft tumor specimens. However, there was downregulation of PARP1, BCL-2, Bcl-x_L, MCL-1, Survivin, XIAP, cIAP2, CDK1, CDK2, CDK4, CDK6, cyclin D1, cyclin E, cyclin A2, cyclin B1, p-Rb, N-cadherin, SNAIL, SLUG, VIMENTIN, SMA, MMP2, MMP3, MMP9 and TWIST in these samples. Furthermore, the xenograft studies showed significant reduction in the tumor growth. Our results suggest that HSP70-2 can promote cellular growth and invasion of EOC cells and therefore may be a potential therapeutic target in EOC.

Role of A-Kinase anchor protein (AKAP4) in growth and survival of ovarian cancer cells

Ovarian cancer represents one of the most common malignancies among women with very high mortality rate worldwide. A-kinase anchor protein 4 (AKAP4), a unique cancer testis (CT) antigen has been shown to be associated with various malignant properties of cancer cells. However, its involvement in various molecular pathways in ovarian cancer remains unknown. In present investigation, employing gene silencing approach, we examined the role of AKAP4 in cell cycle, apoptosis and epithelial-mesenchymal transition (EMT). Further, we also investigated the effect of ablation of AKAP4 on tumor growth in SCID mice ovarian cancer xenograft mouse model. Our results showed that ablation of AKAP4 resulted in increased reactive oxygen species (ROS) generation, DNA damage, cell cycle arrest and apoptosis in ovarian cancer cells. AKAP4 knockdown lead to degradation of protien kinase A (PKA) which was rescued by proteosome inhibitor MG-132. ROS quencher N-acetyl cysteine (NAC) treatment rescued cell cycle arrest and resumed cell division. Subsequently, increased expression of pro-apoptotic molecules and decreased expression of pro-survival/anti-apoptotic factors was observed. As a result of AKAP4 depletion, DNA damage response proteins p-γH2AX, p-ATM and p21 were upregulated. Also, knockdown of CREB resulted in similar findings. Further, PKA inhibitor (H89) and oxidative stress resulted in similar phenotype of ovarian cancer cells as observed in AKAP4 ablated cells. Collectively, for the first time our data showed the involvement of AKAP4 in PKA degradation and perturbed signaling through PKA-CREB axis in AKAP4 ablated ovarian cancer cells.

Expression profile of SPACA5/Spaca5 in spermatogenesis and transitional cell carcinoma of the bladder

The majority of bladder cancer-associated mortalities are due to transitional cell carcinoma (TCC), which is the most prevalent and chemoresistant malignancy of the bladder. Sperm acrosome associated 5 (SPACA5)/Spaca5 is a sperm acrosome-associated, c-type lysozyme-like protein that has been recently identified, and has been designated as an attractive candidate antigen for cancer testis. In the present study, the expression profile of SPACA5/Spaca5 was analyzed in spermatogenesis and TCC of the bladder using diverse molecular and cellular biology methods. Using reverse transcription-polymerase chain reaction (RT-PCR) to analyze the multi-tissue distribution and temporal expression of SPACA5/Spaca5, the SPACA5/Spaca5 gene was determined to be generally not expressed in normal tissue, with the exception of the testis, and it could be detected at a low level on day 20 after birth in mouse testes and at a higher level on day 28. Immunohistochemistry staining revealed that the SPACA5/Spaca5 protein was exclusively observed in the elongated spermatid of the normal testes, and was ectopically expressed in the cytoplasm of TCC, while it was not expressed in normal bladder tissues. The frequency of SPACA5 messenger RNA was detected in 45% of TCC (9/20) by RT-quantitative PCR. Furthermore, SPACA5 protein was more frequently detected in high-grade than in low-grade tumors (61.54 vs. 30.00%, P=0.035). Accordingly, high SPACA5 staining scores were observed to be significantly associated with high-grade tumors (n=65, R=0.279, P=0.027). Collectively, our findings indicated that SPACA5/Spaca5 may be important in male spermatogenesis and may be used as a potential target for specific immunotherapy in patients suffering from TCC.

AKAP4 is a circulating biomarker for non-small cell lung cancer

Cancer testis antigens (CTAs) are widely expressed in tumor tissues, circulating tumor cells (CTCs) and in cancer derived exosomes that are frequently engulfed by lymphoid cells. To determine whether tumor derived CTA mRNAs could be detected in RNA from purified peripheral blood mononuclear cells (PBMC) of non-small cell lung cancer (NSCLC) patients, we assayed for the expression of 116 CTAs in PBMC RNA in a discovery set and identified AKAP4 as a potential NSCLC biomarker. We validated AKAP4 as a highly accurate biomarker in a cohort of 264 NSCLCs and 135 controls from 2 different sites including a subset of controls with high risk lung nodules. When all (264) lung cancers were compared with all (135) controls the area under the ROC curve (AUC) was 0.9714. When 136 stage I NSCLC lung cancers are compared with all controls the AUC is 0.9795 and when all lung cancer patients were compared to 27 controls with histologically confirmed benign lung nodules, a comparison of significant clinical importance, the AUC was 0.9825. AKAP4 expression increases significantly with tumor stage, but independent of age, gender, smoking history or cancer subtype. Follow-up studies in a small number of resected NSCLC patients revealed a decrease of AKAP4 expression post-surgical resection that remained low in patients in remission and increased with tumor recurrence. AKAP4 is a highly accurate biomarker for the detection of early stage lung cancer.

AKAP4 mediated tumor malignancy in esophageal cancer

AKAP4 as a new Cancer/Testis (CT) antigen is expressed not only in human germ cells, but also expressed in various tumor cells. AKAP4 is correlated with tumor malignancy; however, the role of AKAP4 in esophageal cancer remains unknown. Here we explored the function of AKAP4 in esophageal cancer. We found that AKAP4 mRNA and protein levels were up-regulated in the esophageal cancer tissues compared to normal control. In KYSE150 cell line, inhibition of AKAP4 suppressed cell growth and invasiveness. Overexpression of AKAP4 promoted cell growth and invasiveness. In addition, expression of epithelial markers (E-cadherin and ZO-1) was up-regulated or down-regulated and expression of mesenchymal markers (vimentin and N-cadherin) was down-regulated or up-regulated after knockdown or overexpression of AKAP4 in vitro. In vivo in a xenograft model silencing AKAP4 suppressed tumor growth. We also found that NF-κB p65 bound to AKAP4 promoter and regulated expression of AKAP4. In conclusion, overexpression of AKAP4 is associated with esophageal cancer progression. Inhibition of AKAP4 leads to suppressed growth and invasion of esophageal cancer.

A novel cancer testis antigen target A-kinase anchor protein (AKAP4) for the early diagnosis and immunotherapy of colon cancer

Colorectal cancer (CRC) is mainly a disease of developed countries and a major cause of death worldwide. The present study was undertaken to investigate the association of novel cancer testis (CT) antigen, A-kinase anchor protein (AKAP4) with CRC. AKAP4 gene and protein was examined by RT-PCR, in situ hybridization and immunohistochemistry (IHC) in 200 clinical specimens of different stages and grades. In addition, humoral response against AKAP4 was detected by enzyme-linked immunosorbent assay and Western blotting in 172 available sera samples of CRC patients. We observed that majority of CRC patients demonstrated AKAP4 expression and elicited immune response. AKAP4 protein expression, based on immunoreactivity score (IRS) predicted presence of CRC with 84% sensitivity, 100% specificity, 100% of positive predictive value (PPV) and 83.33% negative predictive value (NPV). Humoral response against AKAP4 protein was generated in 82% of the CRC patients. Further, statistical analysis revealed that antibodies found against AKAP4 in CRC patients predicted presence of malignancy with 81.98% sensitivity, 100% specificity, 100% PPV, and 63.53% NPV. Collectively, our data suggests that the majority of CRC cases show significant difference of AKAP4 expression among stages and grades and also generated antibodies against AKAP4 protein. Therefore, AKAP4 may be potential candidate molecule for developing as a biomarker for early diagnosis and immunotherapy of CRC.

Novel cancer antigens for personalized immunotherapies: latest evidence and clinical potential

The clinical success of monoclonal antibody immune checkpoint modulators such as ipilimumab, which targets cytotoxic T lymphocyte-associated antigen 4 (CTLA-4), and the recently approved agents nivolumab and pembrolizumab, which target programmed cell death receptor 1 (PD-1), has stimulated renewed enthusiasm for anticancer immunotherapy, which was heralded by Science as 'Breakthrough of the Year' in 2013. As the potential of cancer immunotherapy has been recognized since the 1890s when William Coley showed that bacterial products could be beneficial in cancer patients, leveraging the immune system in the treatment of cancer is certainly not a new concept; however, earlier attempts to develop effective therapeutic vaccines and antibodies against solid tumors, for example, melanoma, frequently met with failure due in part to self-tolerance and the development of an immunosuppressive tumor microenvironment. Increased knowledge of the mechanisms through which cancer evades the immune system and the identification of tumor-associated antigens (TAAs) and negative immune checkpoint regulators have led to the development of vaccines and monoclonal antibodies targeting specific tumor antigens and immune checkpoints such as CTLA-4 and PD-1. This review first discusses the established targets of currently approved cancer immunotherapies and then focuses on investigational cancer antigens and their clinical potential. Because of the highly heterogeneous nature of tumors, effective anticancer immunotherapy-based treatment regimens will likely require a personalized combination of therapeutic vaccines, antibodies and chemotherapy that fit the specific biology of a patient's disease.

Expression and clinical significance of A-kinase anchor protein 4 in lung adenocarcinoma tissue

BACKGROUND

The A-kinase anchor proteins (AKAP) are a growing family of scaffolding proteins involved in the occurrence, proliferation, and metastasis of tumors by controlling intracellular signals. In this study, the expression and significance of AKAP4 were analyzed in patients with lung adenocarcinoma and adjacent non-cancerous tissues.

METHODS

Using reverse transcriptase-polymerase chain reaction and Western blot, AKAP4 messenger ribonucleic acid (mRNA) and protein expression levels were measured in 108 cases of lung adenocarcinoma and adjacent non-cancerous tissues.

RESULTS

AKAP4 mRNA and protein were expressed in lung adenocarcinoma tissues, but not in adjacent non-cancerous tissues. The expression of AKAP4 mRNA and protein was closely associated with lymphatic metastasis (P < 0.05), but had no relationship with stage, differentiation degree, gender, age or smoking (P > 0.05). AKAP4 expression had an adverse effect on the overall survival rate (P < 0.05).

CONCLUSION

The expression of AKAP4 was high in lung adenocarcinoma tissue, which may be closely related to the lymphatic metastasis of lung adenocarcinoma. AKAP4 may be a novel lung adenocarcinoma molecule marker and a predictor of poor prognosis.

A-kinase anchor protein 4 (AKAP4) a promising therapeutic target of colorectal cancer

Background

Colorectal cancer (CRC) ranks third among the estimated cancer cases and cancer related mortalities in the Western world. Early detection and efficient therapy of CRC remains a major health challenge. Therefore, there is a need to identify novel tumor markers for early diagnosis and treatment of CRC.

Methods

A-kinase anchor protein 4 (AKAP4) gene and protein expression was monitored by quantitative polymerase chain reaction (qPCR), reverse transcription (RT)-PCR and Western blotting in normal colon tissue lysate, normal colon epithelial cells and in colon cancer cell lines viz., Caco-2, COLO205, COLO320DM, HCT-15, HCT116, HT-29, SW480, and SW620. The effect of AKAP4 on cellular growth, migration and invasion abilities was studied using gene silencing approach. The role of AKAP4 in various pathways involved in cell cycle, apoptosis, senescence was investigated in in vitro and in human xenograft mouse model.

Results

Our studies showed that AKAP4 gene and protein expression was expressed in all colon cancer cells while no expression was detectable in normal colon cells. Ablation of AKAP4 led to reduced cellular growth, migration, invasion and increased apoptosis and senescence of CRC cells in in vitro assays and tumor growth in human xenograft mouse. Human colon xenograft studies showed a significant decrease in the levels of cyclins B1, D and E and cyclin dependent kinases such as CDK1, CDK2, CDK4 and CDK6. Interestingly, an up-regulation in the levels of p16 and p21 was also observed. Besides, an increase in the levels of pro-apoptotic molecules AIF, APAF1, BAD, BID, BAK, BAX, PARP1, NOXA, PUMA and cyt-C and Caspase 3, 7, 8 and 9 was also found in cancer cells as well as in xenograft tissue sections. However, anti-apoptotic molecules BCL2, Bcl-x_L, cIAP2, XIAP, Axin2 and Survivin were down regulated in these samples. Our data also revealed elevated expression of epithelial marker E-cadherin and down regulation of EMT markers N-cadherin, P-cadherin, SLUG, α-SMA, SNAIL, TWIST and Vimentin. Further ablation of AKAP4 resulted in the down regulation of invasion molecules matrix metalloproteinase MMP2, MMP3 and MMP9.

Conclusion

AKAP4 appears to be a novel CRC-associated antigen with a potential for developing as a new clinical therapeutic target.

Electronic supplementary material

The online version of this article (doi:10.1186/s13046-015-0258-y) contains supplementary material, which is available to authorized users.

Pharmacological targeting of AKAP-directed compartmentalized cAMP signalling

The second messenger cyclic adenosine monophosphate (cAMP) can bind and activate protein kinase A (PKA). The cAMP/PKA system is ubiquitous and involved in a wide array of biological processes and therefore requires tight spatial and temporal regulation. Important components of the safeguard system are the A-kinase anchoring proteins (AKAPs), a heterogeneous family of scaffolding proteins defined by its ability to directly bind PKA. AKAPs tether PKA to specific subcellular compartments, and they bind further interaction partners to create local signalling hubs. The recent discovery of new AKAPs and advances in the field that shed light on the relevance of these hubs for human disease highlight unique opportunities for pharmacological modulation. This review exemplifies how interference with signalling, particularly cAMP signalling, at such hubs can reshape signalling responses and discusses how this could lead to novel pharmacological concepts for the treatment of disease with an unmet medical need such as cardiovascular disease and cancer.

Targeted immune therapy of ovarian cancer

Clinical outcomes, such as recurrence-free survival and overall survival, in ovarian cancer are quite variable, independent of common characteristics such as stage, response to therapy, and grade. This disparity in outcomes warrants further exploration and therapeutic targeting into the interaction between the tumor and host. One compelling host characteristic that contributes both to the initiation and progression of ovarian cancer is the immune system. Hundreds of studies have confirmed a prominent role for the immune system in modifying the clinical course of the disease. Recent studies also show that anti-tumor immunity is often negated by immune regulatory cells present in the tumor microenvironment. Regulatory immune cells also directly enhance the pathogenesis through the release of various cytokines and chemokines, which together form an integrated pathological network. Thus, in the future, research into immunotherapy targeting ovarian cancer will probably become increasingly focused on combination approaches that simultaneously augment immunity while preventing local immune suppression. In this article, we summarize important immunological targets that influence ovarian cancer outcome as well as include an update on newer immunotherapeutic strategies.

Sperm associated antigen 9 (SPAG9) expression and humoral response in benign and malignant salivary gland tumors

Salivary gland cancers are highly aggressive epithelial tumor associated with metastatic potential and high mortality. The tumors are biologically diverse and are of various histotypes. Besides, the detection and diagnosis is a major problem of salivary gland cancer for available treatment modalities. In the present study, we have investigated the association of sperm associated antigen 9 (SPAG9) expression with salivary gland tumor (SGT). Clinical specimens of benign (n = 16) and malignant tumors (n = 86) were examined for the SPAG9 expression. In addition, the sera and adjacent non-cancerous tissues (n = 72) from available patients were obtained. Our in situ RNA hybridization and immunohistochemistry (IHC) analysis revealed significant difference (p = 0.0001) in SPAG9 gene and protein expression in benign (63%) and malignant tumor (84%) specimens. Further, significant association was also observed between SPAG9 expression and malignant tumors (P = 0.05). A cut-off value of >10% cells expressing SPAG9 protein designated as positive in IHC, predicted presence of malignant SGT with 83.72% sensitivity, 100% specificity, 100% PPV and 83.72% NPV. Humoral response against SPAG9 protein was generated in 68% of SGT patients. A cut-off value of 0.212 OD for anti-SPAG9 antibodies in ELISA predicted presence of malignant SGT with 69.23% sensitivity, 100% specificity, 100% PPV and 78.94% NPV. Collectively, our data suggests that the majority of SGT show significant difference and association among benign and malignant tumors for SPAG9 gene and protein expression and also exhibit humoral response against SPAG9 protein. Hence, SPAG9 may be developed as a biomarker for detection and diagnosis of salivary gland tumors.

Gene silencing of A-kinase anchor protein 4 inhibits cervical cancer growth in vitro and in vivo

Earlier, we reported an association of A-kinase anchor protein 4 (AKAP4) expression in cervical cancer patient specimens, indicating its implications as an immunotherapeutic target. In this study, we investigated the possible role of AKAP4 in cervical carcinogenesis. AKAP4 messenger RNA and protein expression was assessed in four cervical cancer cell line models, C-33A, CaSki, HeLa and SiHa. Gene silencing approach was employed to investigate the potential role of AKAP4 in cellular growth, proliferation, colony-forming ability, migration and invasion in aggressive squamous cell carcinoma cells (SiHa). Further, the effect of downregulation of AKAP4 on tumor growth was examined in the cervical cancer xenograft model in nude mice. Our data clearly indicated that AKAP4 was expressed in all cervical cancer cells at the gene and protein level. We also observed distinct cytoplasmic and surface localization by indirect immunofluorescence and flow cytometry, respectively. Ablation of AKAP4 protein caused significant inhibition in cellular proliferation, colony-forming ability, migration and invasion ability of SiHa cells. Further, gene silencing of AKAP4 also resulted in reduced tumor growth in nude mice in vivo. Collectively, AKAP4 surface localization and its significant association with malignant properties of cervical cancer cells imply its clinical utility as an immunotherapeutic target.