Patient-derived tumor-reactive antibodies as diagnostic markers for ovarian cancer

Tumor and local lymphoid tissue interaction determines prognosis in high-grade serous ovarian cancer

Tertiary lymphoid structure (TLS) is associated with prognosis in copy-number-driven tumors, including high-grade serous ovarian cancer (HGSOC), although the function of TLS and its interaction with copy-number alterations in HGSOC are not fully understood. In the current study, we confirm that TLS-high HGSOC patients show significantly better progression-free survival (PFS). We show that the presence of TLS in HGSOC tumors is associated with B cell maturation and cytotoxic tumor-specific T cell activation and proliferation. In addition, the copy-number loss of IL15 and CXCL10 may limit TLS formation in HGSOC; a list of genes that may dysregulate TLS function is also proposed. Last, a radiomics-based signature is developed to predict the presence of TLS, which independently predicts PFS in both HGSOC patients and immune checkpoint inhibitor (ICI)-treated non-small cell lung cancer (NSCLC) patients. Overall, we reveal that TLS coordinates intratumoral B cell and T cell response to HGSOC tumor, while the cancer genome evolves to counteract TLS formation and function.

Biobehavioral factors predict an exosome biomarker of ovarian carcinoma disease progression

BACKGROUND

Biobehavioral factors such as social isolation and depression have been associated with disease progression in ovarian and other cancers. Here, the authors developed a noninvasive, exosomal RNA profile for predicting ovarian cancer disease progression and subsequently tested whether it increased in association with biobehavioral risk factors.

METHODS

Exosomes were isolated from plasma samples from 100 women taken before primary surgical resection or neoadjuvant (NACT) treatment of ovarian carcinoma and 6 and 12 months later. Biobehavioral measures were sampled at all time points. Plasma from 76 patients was allocated to discovery analyses in which morning presurgical/NACT exosomal RNA profiles were analyzed by elastic net machine learning to identify a biomarker predicting rapid (≤6 months) versus more extended disease-free intervals following initial treatment. Samples from a second subgroup of 24 patients were analyzed by mixed-effects linear models to determine whether the progression-predictive biomarker varied longitudinally as a function of biobehavioral risk factors (social isolation and depressive symptoms).

RESULTS

An RNA-based molecular signature was identified that discriminated between individuals who had disease progression in ≤6 months versus >6 months, independent of clinical variables (age, disease stage, and grade). In a second group of patients analyzed longitudinally, social isolation and depressive symptoms were associated with upregulated expression of the disease progression propensity biomarker, adjusting for covariates.

CONCLUSION

These data identified a novel exosome-derived biomarker indicating propensity of ovarian cancer progression that is sensitive to biobehavioral variables. This derived biomarker may be potentially useful for risk assessment, intervention targeting, and treatment monitoring.

Clinical Significance of Antinucleolar Antibodies: Biomarkers for Autoimmune Diseases, Malignancies, and others

Nucleolar staining is one of the standard patterns in immunofluorescence antinuclear antibodies (ANA), seen in 5-9% of ANA in various conditions. Antinucleolar antibodies (ANoA) are classified into 3 patterns in the International Consensus on ANA Patterns (ICAP) classification; AC-8 homogeneous pattern, AC-9 clumpy pattern, and AC-10 punctate pattern. Specificities known to show AC-8 include anti-Th/To, -PM-Scl, -nucleophosmin/B23, -nucleolin/C23, -No55, and others. AC-9 is seen by anti-fibrillarin/U3RNP and AC-10 by anti-RNA polymerase I and hUBF/NOR-90. ANoA has been classically known to be associated with scleroderma (SSc) and the characterization of nucleolar antigens identified several autoantigens recognized by SSc autoantibodies. The clinical association of anti-Th/To, PM-Scl, fibrillarin/U3RNP, and RNA polymerase I with SSc or SSc-overlap syndrome is well established, and commercial assays are developed. Anti-hUBF/NOR90, nucleophosmin/B23, and nucleolin/C23 are known for decades and reported in systemic autoimmune rheumatic diseases (SARDs), malignancies, graft versus host disease (GVHD), and others; however, their clinical significance remains to be established.

Immune Tumor Microenvironment in Ovarian Cancer Ascites

Ovarian cancer (OC) has a specific type of metastasis, via transcoelomic, and most of the patients are diagnosed at advanced stages with multiple tumors spread within the peritoneal cavity. The role of Malignant Ascites (MA) is to serve as a transporter of tumor cells from the primary location to the peritoneal wall or to the surface of the peritoneal organs. MA comprise cellular components with tumor and non-tumor cells and acellular components, creating a unique microenvironment capable of modifying the tumor behavior. These microenvironment factors influence tumor cell proliferation, progression, chemoresistance, and immune evasion, suggesting that MA play an active role in OC progression. Tumor cells induce a complex immune suppression that neutralizes antitumor immunity, leading to disease progression and treatment failure, provoking a tumor-promoting environment. In this review, we will focus on the High-Grade Serous Carcinoma (HGSC) microenvironment with special attention to the tumor microenvironment immunology.

Immunosuppressive Extracellular Vesicles as a Linking Factor in the Development of Tumor and Endometriotic Lesions in the Gynecologic Tract

Both gynecological tumors and endometriosis require for their development a favorable environment, termed in the case of tumors a "pre-metastatic niche" and in case of endometriosis a "pro-endometriotic niche". This is characterized by chronic inflammation and immunosuppression that support the further progression of initial lesions. This microenvironment is established and shaped in the course of a vivid cross-talk between the tumor or endometrial cells with other stromal, endothelial and immune cells. There is emerging evidence that extracellular vesicles (EVs) play a key role in this cellular communication, mediating both in tumors and endometriosis similar immunosuppressive and pro-inflammatory mechanisms. In this review, we discuss the latest findings about EVs as immunosuppressive factors, highlighting the parallels between gynecological tumors and endometriosis. Furthermore, we outline their role as potential diagnostic or prognostic biomarkers as well as their future in therapeutic applications.

Linking cell-surface GRP78 to cancer: From basic research to clinical value of GRP78 antibodies

Glucose-related protein 78 (GRP78) is a chaperone protein localized primarily in the endoplasmic reticulum (ER) lumen, where it helps in proper protein folding by targeting misfolded proteins and facilitating protein assembly. In stressed cells, GRP78 is translocated to the cell surface (csGRP78) where it binds to various ligands and triggers different intracellular pathways. Thus, csGRP78 expression is associated with cancer, involved in the maintenance and progression of the disease. Extracellular exposition of csGRP78 leads to the production of autoantibodies as observed in patients with prostate or ovarian cancer, in which the ability to target csGRP78 affects the tumor development. Present on the surface of cancer cells and not normal cells in vivo, csGRP78 represents an interesting target for therapeutic antibody strategies. Here we give an overview of the csGRP78 function in the cell and its role in oncogenesis, thereby providing insight into the clinical value of GRP78 monoclonal antibodies for cancer prognosis and treatment.

WFDC Protein: A Promising Diagnosis Biomarker of Ovarian Cancer

An initial diagnosis of cancer is usually based on symptoms, abnormal physical examination and imaging tests. Ovarian cancer is difficult to be diagnosed timely due to the nonspecific symptoms, thus resulting in the high-risk mortality. Despite of the various diagnostic methods, there is still no reliable diagnostic test. Clinically, carbohydrate antigen 125(CA125) is widely recognized as a diagnosis biomarker of ovary cancer. However, CA125 is not sensitive to detect the ovary cancer at the early stage. It is essential to explore other potential biomarkers. Human epididymis protein 4 (HE4) in the whey/four-disulfide core (WFDC) proteins family shows satisfactory sensitivity in the early diagnosis of ovary cancer. In this present review, we summarized the important effects of WFDC family proteins on the proliferation, apoptosis and migration of ovary cancer and intended to provide more evidence to explore the possibility of WFDC protein as a diagnosis biomarker.

Heat Shock Proteins and Ovarian Cancer: Important Roles and Therapeutic Opportunities

Ovarian cancer is a serious cause of death in gynecological oncology. Delayed diagnosis and poor survival rates associated with late stages of the disease are major obstacles against treatment efforts. Heat shock proteins (HSPs) are stress responsive molecules known to be crucial in many cancer types including ovarian cancer. Clusterin (CLU), a unique chaperone protein with analogous oncogenic criteria to HSPs, has also been proven to confer resistance to anti-cancer drugs. Indeed, these chaperone molecules have been implicated in diagnosis, prognosis, metastasis and aggressiveness of various cancers. However, relative to other cancers, there is limited body of knowledge about the molecular roles of these chaperones in ovarian cancer. In the current review, we shed light on the diverse roles of HSPs as well as related chaperone proteins like CLU in the pathogenesis of ovarian cancer and elucidate their potential as effective drug targets.

Exosomes promote pre-metastatic niche formation in ovarian cancer

Ovarian cancer is one of the most common gynecological malignancies. Upon initial diagnosis, the majority of patients present with widespread metastatic growth within the peritoneal cavity. This metastatic growth occurs in stages, with the formation of a pre-metastatic niche occurring prior to macroscopic tumor cell invasion. Exosomes released by the primary ovarian tumor are small extracellular vesicles which prepare the distant tumor microenvironment for accelerated metastatic invasion. They regulate intercellular communication between tumor cells and normal stroma, cancer-associated fibroblasts, and local immune cells within the tumor microenvironment. In this review, we highlight the emerging roles of ovarian cancer exosomes as coordinators of pre-metastatic niche formation, biomarkers amenable to liquid biopsy, and targets of chemotherapy.

Unraveling a difficult diagnosis: the tricks for early recognition of ovarian cancer

Epithelial ovarian cancer (EOC) is the predominant type of ovarian cancer (OC). The 5-year survival of patients has improved over the last three decades, although the overall cure rate of OC if about 30%. Despite high response rates after initial chemotherapy, most patients with advanced ovarian cancer ultimately develop the recurrent disease because of resistance to chemotherapy. A proper early diagnosis and treatment of patients with ovarian cancer are urgently needed. Nowadays the diagnosis is performed by means of clinical symptoms and signs, often indicators of a disease already at an advanced stage, tumor markers (CA125 and HE4), transvaginal ultrasonography and imaging, very useful in distinguishing adnexal masses. Understand the nature of an adnexal mass is the primary point to begin the diagnosis of OC. Validated different model to approach and characterize adnexal pathology preoperatively are described, such as the International Ovarian Tumor Analysis (IOTA) and the Assessment of Different NEoplasias in the AdneXa (ADNEX) model. New tumor markers, such as PRSS8, FOLR1, KLK6/7, GSTT1, and miRNAs, are getting ahead and are worth noting for early detection of ovarian cancer. Despite the development of numerous ultrasound models for the diagnosis of adnexal masses and the analysis of different tumor markers, the early diagnosis of ovarian cancer is still difficult to practice. Moreover, identifying genetic risk alleles, such as germline BRCA1 and BRCA2 mutations, for ovarian cancer has had a significant impact on disease prevention strategies.

MUC16 as a novel target for cancer therapy

INTRODUCTION

MUC16 is overexpressed in multiple cancers and plays an important role in tumorigenicity and acquired resistance to therapy. Area covered: In this review, we describe the role of MUC16 under normal physiological conditions and during tumorigenesis. First, we provide a summary of research on MUC16 from its discovery as CA125 to present anti-MUC16 therapy trials that are currently in the initial phases of clinical testing. Finally, we discuss the reasons for the limited effectiveness of these therapies and discuss the direction and focus of future research. Expert opinion: Apart from its protective role in normal physiology, MUC16 contributes to disease progression and metastasis in several malignancies. Due to its aberrant overexpression, it is a promising target for diagnosis and therapy. Cleavage and shedding of its extracellular domain is the major barrier for efficient targeting of MUC16-expressing cancers. Concerted efforts should be undertaken to target the noncleaved cell surface retained portion of MUC16. Such efforts should be accompanied by basic research to understand MUC16 cleavage and decipher the functioning of MUC16 cytoplasmic tail. While previous efforts to activate anti-MUC16 immune response using anti-CA125 idiotype antibodies have met with limited success, ideification of neo-antigenic epitopes in MUC16 that correlate with improved survival have raised raised hopes for developing MUC16-targeted 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.

Plasma anti-BIRC5 IgG may be a useful marker for evaluating the prognosis of nonsmall cell lung cancer

A recent study demonstrated that circulating levels of IgG antibodies against linear peptide antigens derived from baculoviral IAP repeat-containing protein 5 isoform 2 (BIRC5) and myc proto-oncogene protein (MYC) were significantly increased in nonsmall cell lung cancer (NSCLC). This study was undertaken to replicate this initial work in an independent sample. An enzyme-linked immunosorbent assay (ELISA) was developed in-house to examine plasma IgG antibodies for three linear peptide antigens derived from BIRC5a, BIRC5b, and MYC in 211 patients with NSCLC and 200 control subjects. A Mann-Whitney U-test demonstrated that plasma anti-BIRC5a IgG levels, but not anti-BIRC5b or anti-MYC IgG levels, were significantly higher in NSCLC patients than control subjects, especially in male patients. Both squamous cell cancer and adenocarcinoma showed increased anti-BIRC5a IgG levels, but the IgG levels were not found to be changed significantly in the early stage of NSCLC. Kaplan-Meier survival analysis showed that NSCLC patients with high anti-BIRC5b IgG levels had better prognosis and longer overall survival (OS) than patients with low anti-BIRC5b IgG levels, although this significant difference failed to survive the adjustment for age, gender, NSCLC stages, and types. Plasma anti-BIRC5a and MYC IgG levels did not show significant associations with OS. In conclusion, Plasma anti-BIRC5 IgG may be a useful marker for assessment of prognosis of NSCLC but not for early diagnosis of this malignancy.

[Progress and analysis methods of clinical application of extracellular vesicles]

Extracellular vesicles (EVs) are small vesicles released by cells, which contain proteins and miRNA. It is a new research field in recent years. EVs change accordingly in a variety of diseases. These vesicles can sensitively reflect the pathological changes of the body. Compared with tissue biopsy, EVs detection have the advantages of non-invasive, simple sampling and real-time monitoring. EVs are becoming new diagnostic marker. This article reviews the current status and progress of EVs in clinical application.

Circulating GRP78 antibodies from ovarian cancer patients: a promising tool for cancer cell targeting drug delivery system?

Glucose-regulated protein 78 (GRP78) is a chaperone protein that has a high frequency in tumor cells. Normally it is found in the endoplasmic reticulum to assist in protein folding, but under cellular stress, GRP78 influences proliferative signaling pathways at the cell surface. The increased expression elicits autoantibody production, providing a biomarker of ovarian cancer, as well as other types of cancer. This study aims to determine the epitope recognition of GRP78 autoantibodies isolated from serum of ovarian cancer patients and use the identified antibodies to design new drug delivery systems to specifically target cancer cells. We first confirmed that the membrane GRP78 levels are increased in ovarian cancer cells and positively correlate with proliferation. However, the level of circulating GRP78 autoantibodies did not correlate with membrane GRP78 expression in ovarian cancer cells and was lower, although not significantly, compared to control patients. We then determined the epitope recognition of GRP78 autoantibodies and showed that treatment with paclitaxel-loaded nanoparticles coated with anti-GRP78 antibodies significantly decreased tumor development in chick embryo culture of ovarian cancer cell tumors compared to paclitaxel treatment alone. This evidence suggests that nanoparticle drug delivery systems coupled with antibodies against GRP78 has potential as a powerful therapy against ovarian cancer.

The emerging roles and therapeutic potential of exosomes in epithelial ovarian cancer

Ovarian cancer (OC) is one of the three types of malignant tumors in the female reproductive system, and epithelial ovarian cancer (EOC) is its most typical form. Due to the asymptomatic nature of the early stages and resistance to chemotherapy, EOC has both a poor prognosis and a high fatality rate. Current treatments for OC are very limited, and the 5-years survival rate is approximately 30%. Exosomes, which are microvesicles ranging from approximately 30-100 nm in size that are secreted by living cells, can be produced from different cell types and detected in various body fluids. Cancer cells can secrete more exosomes than healthy cells, and more importantly, the content of cancer cell-derived exosomes is distinct. The exosomes shedding from tumor cells are considered to be involved in tumor progression and metastasis. As such, exosomes are expected to be potential tools for tumor diagnosis and treatment. In this review, we briefly present the emerging roles of exosomes in OC and summarize related articles about their roles as diagnostic or prognostic biomarkers and in the treatment and drug resistance of OC.

Extracellular vesicles in ovarian cancer: applications to tumor biology, immunotherapy and biomarker discovery

In recent years there has been tremendous interest in both the basic biology and applications of extracellular vesicles (EVs) in translational cancer research. This includes a better understanding of their biogenesis and mechanisms of selective cargo packaging, their precise roles in horizontal communication, and their application as non-invasive biomarkers. The rapid advances in next-generation omics technologies are the driving forces for these discoveries. In this review, the authors focus on recent results of EV research in ovarian cancer. A deeper understanding of ovarian cancer-derived EVs, the types of cargo molecules and their biological roles in cancer growth, metastases and drug resistance, could have significant impact on the discovery of novel biomarkers and innovative therapeutics. Insights into the role of EVs in immune regulation could lead to novel approaches built on EV-based immunotherapy.

Identification of Novel and Noninvasive Biomarkers of Acute Cellular Rejection After Liver Transplantation by Protein Microarray

Background

Acute cellular rejection (ACR) is one of the main factors in transplanted organ failure in liver transplantation. A precise marker for diagnosing or predicting rejection is not currently available; therefore, invasive liver biopsy is standard procedure. To develop a noninvasive method for precise diagnosis of ACR, we evaluated autoantibodies from patient sera as potential biomarkers using protein microarrays (seromics).

Methods

Sera from hepatitis C virus–positive ACR patients were compared to three hepatitis C virus cirrhosis control groups and healthy volunteers. The control groups consisted of 2 no-ACR groups obtained on postoperative day 28 and 1 year after transplantation and a preoperative group obtained 1 day before transplantation. For validation, we evaluated whether the candidate antibodies can distinguish ACR from other types of liver dysfunction after liver transplantation using enzyme-linked immunosorbent assay.

Results

Seromic analysis by weighted average difference (WAD) ranking and Mann-Whitney U test revealed a significant increase of 57 autoantibodies in the sera of ACR patients with liver dysfunction. Among the 57 candidates, autoantibodies to charged multivesicular body protein 2B, potassium channel tetramerization domain containing 14, voltage gated subfamily A regulatory beta subunit 3, and triosephosphate isomerase 1 were regarded as potential biomarkers of ACR after liver transplantation. Using 20 ACR patients with variable backgrounds for validation, the autoantibodies to charged multivesicular body protein 2B and triosephosphate isomerase 1 were significantly increased in ACR patients compared to other control groups.

Conclusions

A panel of autoantibodies identified by seromics as potential noninvasive biomarkers was clinically useful for diagnosing ACR after liver transplantation.

Knockdown of Long Noncoding RNA NR_026689 Inhibits Proliferation and Invasion and Increases Apoptosis in Ovarian Carcinoma HO-8910PM Cells

Ovarian cancer is one of the leading causes of gynecological cancer-related deaths worldwide. We investigated the role of a newly discovered long noncoding RNA, NR_026689, in cell proliferation, metastasis, and apoptosis in ovarian cancer cells. Our results showed that NR_026689 was overexpressed in both clinical ovarian cancer patients and cultured ovarian cancer cells. Knockdown of NR_026689 in HO-8910PM cells significantly decreased the cell proliferative rate and the ability to form colonies. Transwell assays revealed that depletion of NR_026689 suppressed cell migration ability by 68% and cell invasive capacity by 71% in HO-8910PM cells. Moreover, specific shRNAs against NR_026689 notably promoted cell apoptosis in HO-8910PM cells by upregulating the expression of proapoptotic proteins, including caspase 3, caspase 9, cytochrome C, and PARP. Our study suggests an oncogenic potential of NR_026689 in ovarian cancer and might provide novel clues for the diagnosis and treatment of ovarian cancer in the clinic.

The Development of an Angiogenic Protein "Signature" in Ovarian Cancer Ascites as a Tool for Biologic and Prognostic Profiling

Advanced ovarian cancer (AOC) is one of the leading lethal gynecological cancers in developed countries. Based on the important role of angiogenesis in ovarian cancer oncogenesis and expansion, we hypothesized that the development of an "angiogenic signature" might be helpful in prediction of prognosis and efficacy of anti-angiogenic therapies in this disease. Sixty-nine samples of ascitic fluid- 35 from platinum sensitive and 34 from platinum resistant patients managed with cytoreductive surgery and 1st-line carboplatin-based chemotherapy- were analyzed using the Proteome ProfilerTM Human Angiogenesis Array Kit, screening for the presence of 55 soluble angiogenesis-related factors. A protein profile based on the expression of a subset of 25 factors could accurately separate resistant from sensitive patients with a success rate of approximately 90%. The protein profile corresponding to the "sensitive" subset was associated with significantly longer PFS (8 [95% Confidence Interval {CI}: 8-9] vs. 20 months [95% CI: 15-28]; Hazard ratio {HR}: 8.3, p<0.001) and OS (20.5 months [95% CI: 13.5-30] vs. 74 months [95% CI: 36-not reached]; HR: 5.6 [95% CI: 2.8-11.2]; p<0.001). This prognostic performance was superior to that of stage, histology and residual disease after cytoreductive surgery and the levels of vascular endothelial growth factor (VEGF) in ascites. In conclusion, we developed an "angiogenic signature" for patients with AOC, which can be used, after appropriate validation, as a prognostic marker and a tool for selection for anti-angiogenic therapies.

In Vitro Validation of Survivin as Target Tumor-associated Antigen for Immunotherapy in Uterine Cancer

Survivin is an antiapoptotic protein, not expressed in terminally differentiated adult tissues, yet overexpressed in several tumors. Therefore, it is an interesting target for immunotherapeutic strategies. In addition to specific overexpression in tumors, tumor survival is mediated by survivin and hence, tumor survival can be tackled by targeting survivin. Survivin expression in uterine cancer was validated by quantitative real-time polymerase chain reaction and immunohistochemistry. In addition, we evaluated survivin immunogenicity by analyzing spontaneous B-cell and T-cell responses in patients. Survivin as a protein was expressed in only a minority of normal tissues, whereas it was being expressed in all of the currently analyzed uterine cancers, both endometrial carcinoma (n = 52) and uterine sarcoma (n = 52). Survivin RNA transcripts were overexpressed in more aggressive tumors and survivin protein was overexpressed in recurrent endometrial tumors compared with primary tumors. Spontaneous T-cell responses were seen in 10/39 endometrial cancer patients and 3/16 uterine sarcoma patients. In normal controls, T-cell responses were found only in 1 donor (n = 21). Although increased antibody titers were found in more aggressive and far-advanced tumors, no differences in B-cell responses were seen. Overall, when compared with normal controls, a B-cell response was only measured in 1/41 uterine sarcoma patients. In conclusion, we currently validated the presence of survivin in uterine cancer. In addition, spontaneous T-cell responses were found in 23.6% of the total patient population. These data indicate that a survivin-specific immune response may be induced spontaneously in patients, further fortifying the eligibility of survivin as an immunotherapeutic target.

Identification of Anti-CA125 Antibody Responses in Ovarian Cancer Patients by a Novel Deep Sequence-Coupled Biopanning Platform

High-grade epithelial ovarian cancer kills more women than any other gynecologic cancer and is rarely diagnosed at an early stage. We sought to identify tumor-associated antigens (TAA) as candidate diagnostic and/or immunotherapeutic targets by taking advantage of tumor autoantibody responses in individuals with ovarian cancer. Plasma-derived IgG from a pool of five patients with advanced ovarian cancer was subjected to iterative biopanning using a library of bacteriophage MS2 virus-like particles (MS2-VLPs) displaying diverse short random peptides. After two rounds of biopanning, we analyzed the selectant population of MS2-VLPs by Ion Torrent deep sequencing. One of the top 25 most abundant peptides identified (DISGTNTSRA) had sequence similarity to cancer antigen 125 (CA125/MUC16), a well-known ovarian cancer-associated antigen. Mice immunized with MS2-DISGTNTSRA generated antibodies that cross-reacted with purified soluble CA125 from ovarian cancer cells but not membrane-bound CA125, indicating that the DISGTNTSRA peptide was a CA125/MUC16 peptide mimic of soluble CA125. Preoperative ovarian cancer patient plasma (n = 100) was assessed for anti-DISGTNTSRA, anti-CA125, and CA125. Patients with normal CA125 (<35 IU/mL) at the time of diagnosis had significantly more antibodies to DISGTNTSRA and to CA125 than those patients who had high CA125 (>35 IU/mL). A statistically significant survival advantage was observed for patients who had either normal CA125 and/or higher concentrations of antibodies to CA125 at the time of diagnosis. These data show the feasibility of using deep sequence-coupled biopanning to identify TAA autoantibody responses from cancer patient plasma and suggest a possible antibody-mediated mechanism for low CA125 plasma concentrations in some ovarian cancer patients.

T cell responses in early-stage melanoma patients occur frequently and are not associated with humoral response

Endogenous tumor-specific T cells are detectable in patients with different tumor types including malignant melanoma (MM). They can control tumor growth, have impact on patient survival and correlate with improved clinical response to immune checkpoint therapy. Thus, they may represent a potent biomarker for respective treatment decisions. So far, major target antigens of endogenous MM-reactive T cells have not been determined systematically. Instead, autoantibodies are discussed as surrogate parameter for MM-specific T cells. Throughout a period of more than 60 days after tumor resection, we therefore determined in 38 non-metastasized primary MM patients and in healthy individuals by IFNγ ELISpot and bead-based fluorescent multiplex assay major target antigens of spontaneous T cell and humoral responses using a broad panel of MM antigens and assessed the presence and suppressive impact of MM-reactive regulatory T cells (Tregs). We show that MM-reactive T cells are frequent in MM patients, transiently increase after tumor removal and are mostly directed against Melan-A/MART-1, Tyrosinase, NA17-A and p53. MM-specific Tregs were only detected in few patients and inhibited MM-reactive T cells particularly early after tumor resection. Tumor-specific autoantibodies occurred in most patients, but did not correlate with T cell responses. Thus, endogenous antibodies may not be reliable surrogate parameters of MM-reactive T cells.

R-Ketorolac Targets Cdc42 and Rac1 and Alters Ovarian Cancer Cell Behaviors Critical for Invasion and Metastasis

Cdc42 (cell division control protein 42) and Rac1 (Ras-related C3 botulinum toxin substrate 1) are attractive therapeutic targets in ovarian cancer based on established importance in tumor cell migration, adhesion, and invasion. Despite a predicted benefit, targeting GTPases has not yet been translated to clinical practice. We previously established that Cdc42 and constitutively active Rac1b are overexpressed in primary ovarian tumor tissues. Through high-throughput screening and computational shape homology approaches, we identified R-ketorolac as a Cdc42 and Rac1 inhibitor, distinct from the anti-inflammatory, cyclooxygenase inhibitory activity of S-ketorolac. In the present study, we establish R-ketorolac as an allosteric inhibitor of Cdc42 and Rac1. Cell-based assays validate R-ketorolac activity against Cdc42 and Rac1. Studies on immortalized human ovarian adenocarcinoma cells (SKOV3ip) and primary patient-derived ovarian cancer cells show that R-ketorolac is a robust inhibitor of growth factor or serum-dependent Cdc42 and Rac1 activation with a potency and cellular efficacy similar to small-molecule inhibitors of Cdc42 (CID2950007/ML141) and Rac1 (NSC23766). Furthermore, GTPase inhibition by R-ketorolac reduces downstream p21-activated kinases (PAK1/PAK2) effector activation by >80%. Multiple assays of cell behavior using SKOV3ip and primary patient-derived ovarian cancer cells show that R-ketorolac significantly inhibits cell adhesion, migration, and invasion. In summary, we provide evidence for R-ketorolac as a direct inhibitor of Cdc42 and Rac1 that is capable of modulating downstream GTPase-dependent, physiologic responses, which are critical to tumor metastasis. Our findings demonstrate the selective inhibition of Cdc42 and Rac1 GTPases by an FDA-approved drug, racemic ketorolac, that can be used in humans.

Kill and spread the word: stimulation of antitumor immune responses in the context of radiotherapy

Besides the direct, targeted effects of ionizing irradiation (x-ray) on cancer cells, namely DNA damage and cell death induction, indirect, nontargeted ones exist, which are mediated in large part by the immune system. Immunogenic forms of tumor cell death induced by x-ray, including immune modulating danger signals like the heat shock protein 70, adenosine triphosphate, and high-mobility group box 1 protein are presented. Further, antitumor effects exerted by cells of the innate (natural killer cells) as well as adaptive immune system (T cells activated by dendritic cells) are outlined. Tumor cell death inhibiting molecules such as survivin are introduced as suitable target for molecularly tailored therapies in combination with x-ray. Finally, reasonable combinations of immune therapies with radiotherapy are discussed.

Autoantibodies against cell surface GRP78 promote tumor growth in a murine model of melanoma

Autoantibodies that react with GRP78 expressed on the cell-surface of many tumor cell lines occur in the sera of patients with prostate cancer, melanoma, and ovarian cancer. These autoantibodies are a negative prognostic factor in prostate cancer and, when purified, stimulate tumor cell proliferation in vitro. It is unclear, however, whether these immunoglobulin Gs are merely a biomarker, or whether they actually promote the tumor growth in vivo. We immunized C57Bl/6 mice with recombinant GRP78 and then implanted the B16F1 murine melanoma cell line as flank tumors. We used the antisera from these mice for in-vitro cell signaling and proliferation assays. The immunodominant epitope in patients with cancer was well represented in the antibody repertoire of these immunized mice. We observed significantly accelerated tumor growth, and shortened survival in GRP78-immunized mice compared with controls. Furthermore, antisera from these mice, and purified anti-GRP78 immunoglobulin G from similarly immunized mice, stimulate Akt phosphorylation and proliferation in B16F1 and human DM6 melanoma cells in culture. These studies show a causal link between a humoral response to GRP78 and the progression of cancer in a murine melanoma model. They support the hypothesis that such autoantibodies are involved in the progression of human cancers and are not simply a biomarker. As GRP78 is present on the surface of many types of cancer cells, this hypothesis has broad clinical and therapeutic implications.

Pharmacological induction of cell surface GRP78 contributes to apoptosis in triple negative breast cancer cells

Breast cancer tumor with triple-negative receptors (estrogen, progesterone and Her 2, receptors) is the most aggressive and deadly subtype, with high rates of disease recurrence and poor survival. Here, we show that induction in cell surface GRP78 by doxorubicin and tunicamycin was associated with CHOP/GADD153 upregulation and increase in apoptosis in triple negative breast cancer tumor cells. GRP78 is a major regulator of the stress induced unfolded protein response pathway and CHOP/GADD153 is a pro-apoptotic transcription factor associated exclusively with stress induced apoptosis. The blocking of cell surface GRP78 by anti-GRP78 antibody prevented apoptosis, suggesting that induction of cell surface GRP78 by doxorubicin and tunicamycin is required for apoptosis. A better understanding of stress induction of apoptotic signaling in triple negative breast cancer cells may help to define new therapeutic strategies.

Autoantibody signature for the serologic detection of ovarian cancer

Sera from patients with ovarian cancer contain autoantibodies (AAb) to tumor-derived proteins that are potential biomarkers for early detection. To detect AAb, we probed high-density programmable protein microarrays (NAPPA) expressing 5177 candidate tumor antigens with sera from patients with serous ovarian cancer (n = 34 cases/30 controls) and measured bound IgG. Of these, 741 antigens were selected and probed with an independent set of ovarian cancer sera (n = 60 cases/60 controls). Twelve potential autoantigens were identified with sensitivities ranging from 13 to 22% at >93% specificity. These were retested using a Luminex bead array using 60 cases and 60 controls, with sensitivities ranging from 0 to 31.7% at 95% specificity. Three AAb (p53, PTPRA, and PTGFR) had area under the curve (AUC) levels >60% (p < 0.01), with the partial AUC (SPAUC) over 5 times greater than for a nondiscriminating test (p < 0.01). Using a panel of the top three AAb (p53, PTPRA, and PTGFR), if at least two AAb were positive, then the sensitivity was 23.3% at 98.3% specificity. AAb to at least one of these top three antigens were also detected in 7/20 sera (35%) of patients with low CA 125 levels and 0/15 controls. AAb to p53, PTPRA, and PTGFR are potential biomarkers for the early detection of ovarian cancer.

The roles of extracellular vesicles in cancer biology: toward the development of novel cancer biomarkers

Recent important progress in cancer biology was the identification of the significant roles played by extracellular vesicles (EVs). EVs are secreted by a variety of mammalian cell types and have been revealed to play important roles in intercellular communications. EVs serve as unique communication vehicles in many ways. First, unlike cytokine signaling, EVs enable transportation not only of proteins, but also of nucleic acids, including mRNAs and microRNAs. Recent reports showing the functionality of these nucleic acids in the recipient cells have opened up a new avenue of cell-to-cell communication research. Second, EVs have been revealed to transport membrane components including receptors, such as epithelial growth factor receptor. These findings have provided significant insights into understanding the molecular mechanisms of cancer development. Third, EVs protect their contents from clearance by degrading enzymes present in the extracellular space, which allows for remote transportation of the contents, even between organs. This concept is highlighted by recent reports that suggest the deep involvement of cancer cell derived EVs in metastasis. From these points of view, we will summarize recent studies on the relevance of EVs in cancer biology. We will also highlight the possibility of novel diagnostic technologies using circulating EVs in body fluid.

Salivary auto-antibodies as noninvasive diagnostic markers of oral cavity squamous cell carcinoma

BACKGROUND

Oral cavity squamous cell carcinoma (OSCC) is one of the most common cancers worldwide, and its incidence is still increasing. Approximately 50% of patients with OSCC die within 5 years after diagnosis, mostly ascribed to the fact that the majority of patients present advanced stages of OSCC at the time of diagnosis.

METHODS

To discover salivary biomarkers for ameliorating the detection of OSCC, herein, we developed a multiplexed bead-based platform to simultaneously detect auto-antibodies (auto-Abs) in salivary samples.

RESULTS

Compared with healthy individuals, the salivary levels of anti-p53, anti-survivin, anti-Hsp60, and anti-RPLP0 were significantly elevated in patients with OSCC. Noteworthily, the elevated levels of anti-p53, anti-survivin, and anti-Hsp60 were already observed in individuals with oral potentially malignant disorder. Moreover, the salivary levels of anti-p53, anti-survivin, anti-Hsp60, anti-RPLP0, and anti-CK8 were significantly elevated in patients with early-stage OSCC compared with those in healthy individuals. Most importantly, the use of a combined panel of salivary anti-p53, anti-survivin, anti-Hsp60, and anti-RPLP0 largely improves the detection of OSCC.

CONCLUSION

Collectively, our results reveal that the salivary auto-Abs are effective OSCC biomarkers and the four-auto-Ab panel provides a novel and practicable approach for OSCC screening.

IMPACT

This study provides the first evidence for the potential clinical application of salivary auto-Abs in OSCC diagnosis.

Cancer antigen 125, human epididymis 4, kallikrein 6, osteopontin and soluble mesothelin-related peptide immunocomplexed with immunoglobulin M in epithelial ovarian cancer diagnosis

BACKGROUND

Human epididymis protein 4 (HE4), kallikrein 6 (KLK6), osteopontin (OPN) and soluble mesothelin-related peptide (SMRP) are new promising biomarkers that could integrate CA125 in epithelial ovarian cancer (EOC) diagnosis. The autoantibody response to tumor antigens is a potential tool for improving the diagnostic performances of biomarkers. The aim of this study was to assess the diagnostic potential of these biomarkers in the form of free markers and immunocomplexed with immunoglobulin M (IgM). Moreover, we analyzed the association between these markers and clinico-pathological characteristics of EOC patients.

METHODS

Serum and plasma samples of 60 healthy controls, 60 ovarian benign cysts, 60 endometriosis and 60 EOCs, collected before any treatment, were tested for CICs and free antigens by immunoassays.

RESULTS

Immunocomplexes were characterized by poor sensitivity and specificity, since they allowed the detection only of a small number of EOC patients and were increased in patients with benign gynecological pathologies. However, the markers in the form of free antigens showed good diagnostic performances. Of note, CA125 and HE4 showed high sensitivity in the detection of the malignancy and HE4 emerged as a useful biomarker in differential diagnosis between EOC and endometriosis. Finally, elevated KLK6 and OPN, were associated with advanced FIGO stage, high grade disease, suboptimally debulked tumor and ascites.

CONCLUSIONS

This study confirms the diagnostic role of CA125, HE4, KLK6, OPN and SMRP, and for the first time showed that CA125, HE4, KLK6, OPN and SMRP immunocomplexed with IgM are not a potential tool for EOC diagnosis.

Proteomics analysis of normal and senescent NG108-15 cells: GRP78 plays a negative role in cisplatin-induced senescence in the NG108-15 cell line

Accelerated senescence (ACS) leading to proliferative arrest is a physiological mechanism of the DNA damage response that occurs during tumor therapy. Our experiment was designed to detect unknown genes that may play important roles in cisplatin-induced senescence and to illustrate the related senescence mechanism. Using 2-dimension electrophoresis (2-DE), we identified 5 protein spots with different expression levels in the normal and senescent NG108-15 cells. According to MALDI-TOF MS analysis, the 5 proteins were determined to be peptidylprolyl isomerase A (PPIA), peroxiredoxin 1 (PRX1), glutathione S-transferase mu 1 (GSTM1), vimentin (VIM) and glucose-regulated protein 78 (GRP78). Then, we investigated how cisplatin-induced senescence was mediated by GRP78 in the NG108-15 cells. Knockdown of GRP78 significantly increased P53 expression in NG108-15 cells. Additionally, 2-deoxy-D-glucose (2DG)-induced GRP78 overexpression protected the NG108-15 cells from cisplatin-induced senescence, which was accompanied by the obvious suppression of P53 and p-CDC2 expression. Inhibition of Ca2+ release from endoplasmic reticulum (ER) stores was also found to be associated with the anti-senescence effect of 2DG-induced GRP78 overexpression. In conclusion, we found 5 proteins that were differentially expressed in normal NG108-15 cells and senescent NG108-15 cells. GRP78 plays an important role in cisplatin-induced senescence in NG108-15 cells, mainly through its regulation of P53 expression and ER calcium efflux.

Antibodies against Hsp60 and Hsp65 in the sera of women with ovarian cancer

Background

The aim of this study was to evaluate the concentrations of IgG antibodies against Hsp60 and Hsp65 in sera of patients with ovarian cancer at various stages of clinical progress and for different histopathological types of disease.

Methods

Serum samples from 149 patients with ovarian carcinoma and 80 healthy women were investigated. The concentrations of anti-Hsp60 and anti-Hsp65 antibodies were determined using the enzyme-linked immunosorbent assay technique.

Results

The mean concentrations of anti-Hsp60 and anti-Hsp65 antibodies in the patients with ovarian cancer did not differ significantly from the mean levels in healthy women. Analysis in relation to the clinical progression stage showed that the concentrations of these antibodies were higher when the neoplastic process was less advanced and at early stages significantly higher than in control group. Mean concentrations of both antibodies were not significantly different in relation to the histological type of the ovarian cancer. The use of chemotherapy as a primary anticancer treatment did not cause a significant change in the concentration of anti-Hsp60 antibodies, but the mean level of anti-Hsp65 after this treatment was significantly higher than in control group.

Conclusions

The immunological response to Hsp60/65 is increased in early clinical stages of ovarian cancer and the level of anti-hsp60/65 antibodies may be then a helpful diagnostic marker. Even antibodies against highly homologous Hsps may be cross-reactive only partially and differ by some functional properties.

Microvesicles as mediators of intercellular communication in cancer

The discovery that cancer cells generate large membrane-enclosed packets of epigenetic information, known as microvesicles (MVs), that can be transferred to other cells and influence their behavior (Antonyak et al., Small GTPases 3:219-224, 2012; Cocucci et al., Trends Cell Biol 19:43-51, 2009; Rak, Semin Thromb Hemost 36:888-906, 2010; Skog et al., Nat Cell Biol 10:1470-1476, 2008) has added a unique perspective to the classical paracrine signaling paradigm. This is largely because, in addition to growth factors and cytokines, MVs contain a variety of components that are not usually thought to be released into the extracellular environment by viable cells including plasma membrane-associated proteins, cytosolic- and nuclear-localized proteins, as well as nucleic acids, particularly RNA transcripts and micro-RNAs (Skog et al., Nat Cell Biol 10:1470-1476, 2008; Al-Nedawi et al., Nat Cell Biol 10:619-624, 2008; Antonyak et al., Proc Natl Acad Sci U S A 108:4852-4857, 2011; Balaj et al., Nat Commun 2:180, 2011; Choi et al., J Proteome Res 6:4646-4655, 2007; Del Conde et al., Blood 106:1604-1611, 2005; Gallo et al., PLoS One 7:e30679, 2012; Graner et al., FASEB J 23:1541-1557, 2009; Grange et al., Cancer Res 71:5346-5356, 2011; Hosseini-Beheshti et al., Mol Cell Proteomics 11:863-885, 2012; Martins et al., Curr Opin Oncol 25:66-75, 2013; Noerholm et al., BMC Cancer 12:22, 2012; Zhuang et al., EMBO J 31:3513-3523, 2012). When transferred between cancer cells, MVs have been shown to stimulate signaling events that promote cell growth and survival (Al-Nedawi et al., Nat Cell Biol 10:619-624, 2008). Cancer cell-derived MVs can also be taken up by normal cell types that surround the tumor, an outcome that helps shape the tumor microenvironment, trigger tumor vascularization, and even confer upon normal recipient cells the transformed characteristics of a cancer cell (Antonyak et al., Proc Natl Acad Sci U S A 108:4852-4857, 2011; Martins et al., Curr Opin Oncol 25:66-75, 2013; Al-Nedawi et al., Proc Natl Acad Sci U S A 106:3794-3799, 2009; Ge et al., Cancer Microenviron 5:323-332, 2012). Thus, the production of MVs by cancer cells plays crucial roles in driving the expansion of the primary tumor. However, it is now becoming increasingly clear that MVs are also stable in the circulation of cancer patients, where they can mediate long-range effects and contribute to the formation of the pre-metastatic niche, an essential step in metastasis (Skog et al., Nat Cell Biol 10:1470-1476, 2008; Noerholm et al., BMC Cancer 12:22, 2012; Peinado et al., Nat Med 18:883-891, 2012; Piccin et al., Blood Rev 21:157-171, 2007; van der Vos et al., Cell Mol Neurobiol 31:949-959, 2011). These findings, when taken together with the fact that MVs are being aggressively pursued as diagnostic markers, as well as being considered as potential targets for intervention against cancer (Antonyak et al., Small GTPases 3:219-224, 2012; Hosseini-Beheshti et al., Mol Cell Proteomics 11:863-885, 2012; Martins et al., Curr Opin Oncol 25:66-75, 2013; Ge et al., Cancer Microenviron 5:323-332, 2012; Peinado et al., Nat Med 18:883-891, 2012; Piccin et al., Blood Rev 21:157-171, 2007; Al-Nedawi et al., Cell Cycle 8:2014-2018, 2009; Cocucci and Meldolesi, Curr Biol 21:R940-R941, 2011; D'Souza-Schorey and Clancy, Genes Dev 26:1287-1299, 2012; Shao et al., Nat Med 18:1835-1840, 2012), point to critically important roles for MVs in human cancer progression that can potentially be exploited to develop new targeted approaches for treating this disease.

Ascites analysis by a microfluidic chip allows tumor-cell profiling

Ascites tumor cells (ATCs) represent a potentially valuable source of cells for monitoring treatment of ovarian cancer as it would obviate the need for more invasive surgical biopsies. The ability to perform longitudinal testing of ascites in a point-of-care setting could significantly impact clinical trials, drug development, and clinical care. Here, we developed a microfluidic chip platform to enrich ATCs from highly heterogeneous peritoneal fluid and then perform molecular analyses on these cells. We evaluated 85 putative ovarian cancer protein markers and found that nearly two-thirds were either nonspecific for malignant disease or had low abundance. Using four of the most promising markers, we prospectively studied 47 patients (33 ovarian cancer and 14 control). We show that a marker set (ATCdx) can sensitively and specifically map ATC numbers and, through its reliable enrichment, facilitate additional treatment-response measurements related to proliferation, protein translation, or pathway inhibition.

Immune cells in the normal ovary and spontaneous ovarian tumors in the laying hen (Gallus domesticus) model of human ovarian cancer

Background

Spontaneous ovarian cancer in chickens resembles human tumors both histologically and biochemically. The goal was to determine if there are differences in lymphocyte content between normal ovaries and ovarian tumors in chickens as a basis for further studies to understand the role of immunity in human ovarian cancer progression.

Methods

Hens were selected using grey scale and color Doppler ultrasound to determine if they had normal or tumor morphology. Cells were isolated from ovaries (n = 6 hens) and lymphocyte numbers were determined by flow cytometry using antibodies to avian CD4 and CD8 T and B (Bu1a) cells. Ovarian sections from another set of hens (n = 26) were assessed to verify tumor type and stage and to count CD4, CD8 and Bu1a immunostained cells by morphometric analysis.

Results

T and B cells were more numerous in ovarian tumors than in normal ovaries by flow cytometry and immunohistochemistry. There were less CD4+ cells than CD8+ and Bu1a+ cells in normal ovaries or ovarian tumors. CD8+ cells were the dominant T cell sub-type in both ovarian stroma and in ovarian follicles compared to CD4+ cells. Bu1a+ cells were consistently found in the stroma of normal ovaries and ovarian tumors but were not associated with follicles. The number of immune cells was highest in late stage serous tumors compared to endometrioid and mucinous tumors.

Conclusions

The results suggest that similar to human ovarian cancer there are comparatively more immune cells in chicken ovarian tumors than in normal ovaries, and the highest immune cell content occurs in serous tumors. Thus, this study establishes a foundation for further study of tumor immune responses in a spontaneous model of ovarian cancer which will facilitate studies of the role of immunity in early ovarian cancer progression and use of the hen in pre-clinical vaccine trials.

Autoantibody biomarkers identified by proteomics methods distinguish ovarian cancer from non-ovarian cancer with various CA-125 levels

PURPOSE

CA-125 has been a valuable marker for detecting ovarian cancer, however, it is not sensitive enough to detect early-stage disease and not specific to ovarian cancer. The purpose of our study was to identify autoantibody markers that are specific to ovarian cancer regardless of CA-125 levels.

METHODS

Top-down and iTRAQ quantitative proteomics methods were used to identify high-frequency autoantibodies in ovarian cancer. Protein microarrays comprising the recombinant autoantigens were screened using serum samples from various stages of ovarian cancer with diverse levels of CA-125 as well as benign and healthy controls. ROC curve and dot blot analyses were performed to validate the sensitivity and specificity of the autoantibody markers.

RESULTS

The proteomics methodologies identified more than 60 potential high-frequency autoantibodies in ovarian cancer. Individual serum samples from ovarian cancer stages I-IV compared to control samples that were screened on a microarray containing native recombinant autoantigens revealed a panel of stage I high-frequency autoantibodies. Preliminary ROC curve and dot blot analyses performed with the ovarian cancer samples showed higher specificity and sensitivity as compared to CA-125. Three autoantibody markers exhibited higher specificity in various stages of ovarian cancer with low and normal CA-125 levels.

CONCLUSIONS

Proteomics technologies are suitable for the identification of protein biomarkers and also the identification of autoantibody biomarkers when combined with protein microarray screening. Using native recombinant autoantigen arrays to screen autoantibody markers, it is possible to identify markers with higher sensitivity and specificity than CA-125 that are relevant to early detection of ovarian cancer.

Potential tumor biomarkers identified in ovarian cyst fluid by quantitative proteomic analysis, iTRAQ

BACKGROUND

Epithelial-derived ovarian adenocarcinoma (EOC) is the most deadly gynecologic tumor, and the principle cause of the poor survival rate is diagnosis at a late stage. Screening and diagnostic biomarkers with acceptable specificity and sensitivity are lacking. Ovarian cyst fluid should harbor early ovarian cancer biomarkers because of its closeness to the tumor. We investigated ovarian cyst fluid as a source for discovering biomarkers for use in the diagnosis of EOC.

RESULTS

Using quantitative mass spectrometry, iTRAQ MS, we identified 837 proteins in cyst fluid from benign, EOC stage I, and EOC stage III. Only patients of serous histology were included in the study. Comparing the benign (n = 5) with the malignant (n = 10) group, 87 of the proteins were significantly (p < 0.05) differentially expressed. Two proteins, serum amyloid A-4 (SAA4) and astacin-like metalloendopeptidase (ASTL), were selected for verification of the iTRAQ method and external validation with immunoblot in a larger cohort with mixed histology, in plasma (n = 68), and cyst fluid (n = 68). The protein selections were based on either high significance and high fold change or abundant appearance and several peptide recognitions in the sample sets (p = 0.04, FC = 1.95) and (p < 0.001, FC = 8.48) for SAA4 and ASTL respectively. Both were found to be significantly expressed (p < 0.05), but the methods did not correlate concerning ASTL.

CONCLUSIONS

Fluid from ovarian cysts connected directly to the primary tumor harbor many possible new tumor-specific biomarkers. We have identified 87 differentially expressed proteins and validated two candidates to verify the iTRAQ method. However several of the proteins are of interest for validation in a larger setting.

Exosomes from triple-negative breast cancer cells can transfer phenotypic traits representing their cells of origin to secondary cells

BACKGROUND

Triple-negative breast cancer (TNBC) accounts for 15-20% of breast cancers but is responsible for a disproportionate number of deaths. We investigated the relevance, in TNBC, of nano-sized exosomes expelled from cells. Specifically, we compared effects of exosomes derived from the claudin-low TNBC cell line Hs578T and its more invasive Hs578Ts(i)8 variant, as well as exosomes from TNBC patient sera compared to normal sera.

METHODS

Exosomes were isolated from conditioned media (CM) of Hs578T and Hs578Ts(i)8 cells and from sera by filtration and ultracentrifugation. Successful isolation was confirmed by transmission electron microscopy and immunoblotting. Subsequent analysis, of secondary/recipient cells in response to exosomes, included proliferation; motility/migration; invasion; anoikis assays and endothelial tubule formation assays.

RESULTS

Hs578Ts(i)8-exosomes versus Hs578T-exosomes significantly increased the proliferation, migration and invasion capacity of all three recipient cell lines evaluated i.e. SKBR3, MDA-MB-231 and HCC1954. Exosomes from Hs578Ts(i)8 cells also conferred increased invasiveness to parent Hs578T cells. Hs578Ts(i)8-exosomes increased sensitivity of SKBR3, MDA-MB-231 and HCC1954 to anoikis when compared to the effects of Hs578T-exosomes reflecting the fact that Hs578Ts(i)8 cells are themselves innately more sensitive to anoikis. In relation to vasculogenesis and subsequent angiogenesis, Hs578Ts(i)8-exosomes versus Hs578T-exosomes stimulated significantly more endothelial tubules formation. Finally, our pilot translational study showed that exosomes from TNBC patients' sera significantly increased recipient cells' invasion when compared to those derived from age- and gender-matched healthy control sera.

CONCLUSION

This study supports the hypothesis that TNBC exosomes may be involved in cancer cell-to-cell communication, conferring phenotypic traits to secondary cells that reflect those of their cells of origin.

Exosomes as a potential tool for a specific delivery of functional molecules

Extracellular membrane vesicles derived from the endosomal compartments and released by the fusion of the multivesicular bodies with the cell membrane are referred as exosomes (Exo) [Van Niel et al., J Biochem 140:13-21, 2006]. They function as mediators of intercellular communication and are employed by the organism in the regulation of systemic and local processes. Meantime, Exo are recognized as an indispensable entity of physiological fluids [Caby et al., Int Immunol 17:879-887, 2005; Lasser et al., J Transl Med 9:9, 2011; Lasser et al., Am J Rhinol Allergy 25:89-93, 2011]. Exo and other types of extracellular vesicles, e.g., exosome-like vesicles [van Niel et al., Gastroenterology 121:337-349, 2001] and microvesicles (MV) [Daveloose et al., Thromb Res 22:195-201, 1981], contain multiple functional molecules including lipids [Vidal et al., J Cell Physiol 140:455-462, 1989]; proteins [Simpson et al., Expert Rev Proteomics 6:267-283, 2009]; mRNA [Valadi et al., Nat Cell Biol 9:654-659, 2007]; DNA [Waldenstrom et al., PLoS One 7:e34653, 2012]; noncoding RNA, e.g., miRNA [Simpson et al., Expert Rev Proteomics 6:267-283, 2009]; and retrotransposon elements [Balaj et al., Nat Commun 2:180, 2011]. Assessment of the biological functions of Exo showed that they deliver specifically their cargo from the donor to recipient cells. Albeit the molecular mechanisms of this process are not fully understood, approaches for the application of Exo and MV as a tool for a cell-specific delivery of signalling molecules were successfully tested in in vitro and in vivo models [Maguire et al., Mol Ther 20:960-971, 2012]. Ovarian cancer cells release Exo, which bind stroma cells as well as donor cancer cells [Escrevente et al., BMC Cancer 11:108, 2011]. Here we describe an experimental approach for the assessment of Exo interaction and uptake by target cells. Methods for the isolation and purification of Exo from cell culture supernatants are included. To allow visualization of vesicle uptake, labelling of Exo with different fluorescent dyes, such as CFSE, PKH, DHPE, and DiOC18, is presented. Finally, we explain qualitative and quantitative analysis of Exo uptake by immunofluorescence and flow cytometry, respectively.

Alpha 1-antitrypsin: a novel tumor-associated antigen identified in patients with early-stage breast cancer

Several studies have demonstrated that sera from patients with cancer contain antibodies that recognize a unique group of autologous antigens called tumor-associated antigens (TAA). In the current study, we employed an immunoproteomic approach, combining 2DE, Western blot, and MALDI-MS to identify TAA in the sera of patients diagnosed with infiltrating ductal or in situ carcinoma breast cancer. Sera obtained from 25 newly diagnosed patients with stage II breast cancer and 20 healthy volunteers was evaluated for the presence of novel TAA. Alpha 1-antitrypsin (A1AT) antibodies were detected in 24 of 25 patients with breast cancer (96%) and in 2 of 20 controls (10%). Sensitivity of detection of autoantibodies against A1AT in patients with breast cancer was 96%. Our preliminary results suggest that A1AT and autoantibodies against alpha 1 antitrypsin may be useful serum biomarkers for early-stage breast cancer screening and diagnosis.

Anti-ovarian antibodies in sera of patients with ovarian tumors

AIM OF PAPER

The purpose of this study was to assess the presence of anti-ovarian autoantibodies in sera of patients with ovarian tumors.

MATERIALS AND METHODS

The study group consisted of 82 patients treated at the Division of Gynecological Surgery, Poznan University of Medical Sciences, Poland in 2007-2011. 46 patients with malignant ovarian tumors and 36 patients diagnosed with benign ovarian tumor were included into the study. Age-matched healthy control groups consisted of 15 women and 19 men. Anti-ovarian autoantibodies in serum were assessed with the use of indirect immunofluorescence. The presence of anti-ovarian autoantibodies in serum was correlated with clinical and histopathological features of the disease.

RESULTS

Serum anti-ovarian autoantibodies were found in 59% (27/46) of patients with malignant ovarian tumors, compared to 55% (20/36) and 26% (4/15) of patients with benign ovarian tumors and healthy female controls respectively. The difference was statistically significant (P=0.04). All serum samples from the male controls were negative. Anti-ovarian antibodies occurred more often among advanced stage (III and IV stage according to FIGO, P=0.037) and grade 3 (P=0.049) ovarian cancers, however, there were no differences in median progression-free survival (P=0.388). The presence of anti-ovarian antibodies was neither influenced by histopathological type of the tumor, menopausal status, presence of ascites nor CA125 levels. Seropositivity for anti-ovarian antibodies was correlated positively with patients' age and negatively with tumor size.

CONCLUSIONS

Anti-ovarian autoantibodies develop with higher frequency in ovarian cancer comparing to healthy controls, however with similar proportion to benign ovarian tumors patients. The presence of antibodies against normal ovarian tissue correlates with ovarian cancer aggressiveness.