Aberrant expression of homeobox gene HOXA7 is associated with müllerian-like differentiation of epithelial ovarian tumors and the generation of a specific autologous antibody response

Single-cell RNA-sequencing analysis reveals divergent transcriptome events between platinum-sensitive and platinum-resistant high-grade serous ovarian carcinoma

BACKGROUND

Tumor resistance is one of the main reasons leading to the failure of ovarian cancer treatment. Overcoming platinum resistance remains the greatest challenge in the management of high-grade serous ovarian carcinoma (HGSC).

METHODS

Small conditional RNA-sequencing is a powerful method for exploring the complexity of the cellular components and their interactions in the tumor microenvironment. We profiled the transcriptomes of 35,042 cells from two platinum-sensitive and three platinum resistance HGSC clinical cases downloaded from Gene Expression Omnibus (GSE154600) and annotated tumor cells as platinum-resistant or sensitive based on the clinical trait. The study systematically investigated the inter-tumoral (using differential expression analysis, CellChat, and SCENIC) and intra-tumoral heterogeneity (using enrichment analysis such as gene set enrichment analysis, as well as gene set variation analysis, weighted gene correlation network analysis, and Pseudo-time analysis) of HGSC.

RESULTS

A cellular map of HGSC generated by profiling 30,780 cells was revisualized using Uniform Manifold Approximation and Projection. The inter-tumoral heterogeneity was demonstrated with intercellular ligand-receptor interactions of major cell types and regulons networks. FN1, SPP1, and COLLAGEN play important roles in the cross-talk between tumor cells and the tumor microenvironment. HOXA7, HOXA9_extended, TBL1XR1_extended, KLF5, SOX17, and CTCFL regulons consistent with the distribution of platinum-resistant HGSC cells were the high activity regions. The intra-tumoral heterogeneity of HGSC was presented with corresponding functional pathway characteristics, tumor stemness features, and the cellular lineage transition from platinum-sensitive to resistant condition. Epithelial-mesenchymal transition played an important role in platinum resistance, whereas oxidative phosphorylation was the opposite. There was a small subset of cells in platinum-sensitive samples that had transcriptomic characteristics similar to platinum-resistant cells, suggesting that the progression of platinum resistance in ovarian cancer is inevitable.

CONCLUSIONS

The present study describes a view of HGSC at single-cell resolution that reveals the characteristics of the HGSC heterogeneity and provides a useful framework for future investigation of platinum-resistant.

Multichannel Recovery Potential with Activated Autologous Intraovarian Platelet-Rich Plasma and Its Derivatives

Platelet-rich plasma (PRP) is an 'orthobiologic' with recognized roles in plastic surgery, musculoskeletal disorders, dentistry, dermatology, and more recently, 'ovarian rejuvenation'. Intraovarian PRP involves a complex secretome discharged after platelet activation, comprising multiple cytokine mediators delivered surgically to older or inactive ovarian tissue. Loss of oocyte meiotic fidelity and impaired fertilization accompanying advanced maternal age are already managed by IVF, but only with eggs provided by younger donors. However, if the observed effect of rectifying embryo ploidy error can be proven beyond case reports and small series, activated PRP (or its condensed plasma cytokines) would deliver a welcome therapeutic disruption that is difficult to overstate. Because shortcomings in ovarian function are presently addressed mainly by pharmacological approaches (i.e., via recombinant gonadotropins, GnRH analogs, or luteal support), autologous PRP would represent an unusual departure from these interventions. Given the diversity of platelet cargo proteins, the target response of intraovarian PRP is probably not confined to oocytes or follicles. For example, PRP manipulates signal networks driving improved perfusion, HOX regulation, N-glycan post-translational modification, adjustment of voltage-gated ion channels, telomere stabilization, optimization of SIRT3, and ribosome and mitochondria recovery in older oocytes. While multichannel signals operating on various pathways are not unique to reproductive biology, in intraovarian PRP this feature has received little study and may help explain why its standardization has been difficult. Against this background, our report examines the research themes considered most likely to shape clinical practice.

Current and Emerging Methods for Ovarian Cancer Screening and Diagnostics: A Comprehensive Review

With a 5-year survival rate of less than 50%, ovarian high-grade serous carcinoma (HGSC) is one of the most highly aggressive gynecological malignancies affecting women today. The high mortality rate of HGSC is largely attributable to delays in diagnosis, as most patients remain undiagnosed until the late stages of -disease. There are currently no recommended screening tests for ovarian cancer and there thus remains an urgent need for new diagnostic methods, particularly those that can detect the disease at early stages when clinical intervention remains effective. While diagnostics for ovarian cancer share many of the same technical hurdles as for other cancer types, the low prevalence of the disease in the general population, coupled with a notable lack of sensitive and specific biomarkers, have made the development of a clinically useful screening strategy particularly challenging. Here, we present a detailed review of the overall landscape of ovarian cancer diagnostics, with emphasis on emerging methods that employ novel protein, genetic, epigenetic and imaging-based biomarkers and/or advanced diagnostic technologies for the noninvasive detection of HGSC, particularly in women at high risk due to germline mutations such as BRCA1/2. Lastly, we discuss the translational potential of these approaches for achieving a clinically implementable solution for screening and diagnostics of early-stage ovarian cancer as a means of ultimately improving patient outcomes in both the general and high-risk populations.

Contribution of TWIST1-EVX1 Axis in Invasiveness of Esophageal Squamous Cell Carcinoma; a Functional Study

BACKGROUND

Epithelial-mesenchymal transition (EMT) is a biological process in embryonic development and cancer progression, and different gene families, such as HOX genes, are closely related to this process.

OBJECTIVES

Our aim in this study was to investigate the correlation between TWIST1 and EVX1 mRNA expression in ESCC patients and also examine the probable regulatory function of TWIST1 on EVX1 expression in human ESCC cell line.

MATERIALS AND METHODS

TWIST1 and EVX1 gene expression patterns were assessed in ESCC patients by relative comparative Real-time PCR then correlated with their clinical characteristics. In silico analysis of the EVX1 gene was conducted. KYSE-30 cells were transduced by a retroviral system to ectopically express TWIST1, followed by qRT-PCR to reveal the correlation between TWIST1 and EVX1 gene expression.

RESULTS

The expression of TWIST1 and EVX1 was correlated to each other significantly (p=0.005) in ESCC. Of 28 patients with under/normal expression of TWIST1, 22 samples (78.57%) had over/normal expression of EVX1. TWIST1 overexpression was correlated with advanced stages of the tumor (III, IV) (P = 0.019) and lymph node metastasis. However, EVX1 under expression was associated with lymph node metastasis (p = 0.027) and invasiveness of the disease (P = 0.037) in ESCC. Furthermore, retroviral transduction enforced significant overexpression of TWIST1 in GFP-hTWIST-1 approximately 9-fold compared to GFP control cells, causing a - 8.83- fold reduction in EVX1 mRNA expression significantly.

CONCLUSIONS

Our results indicated the repressive role of TWIST1 on EVX1 gene expression in ESCC. Therefore, our findings can help dissect the molecular mechanism of ESCC tumorigenesis and discover novel therapeutic targets for ESCC invasion and metastasis.

Identification of HOXD10 as a Marker of Poor Prognosis in Glioblastoma Multiforme

Purpose

HOXD10 is a tumor modulator that can either be a tumor-suppressor or a tumor-promoting gene. However, the role of HOXD10 in glioblastoma multiforme (GBM) remains unclear.

Methods

Immunohistochemistry (IHC) was applied to detect protein expression of HOXD10 in GBM and normal brain tissue patients. Clinicopathological characteristics with GBM were recorded, and a Kaplan–Meier curve was plotted. Additionally, the mRNA expression of HOXD10 and its effect on prognosis were analyzed using the online tool GEPIA and the Cancer Genome Atlas (TCGA), Chinese Glioma Genome Atlas (CGGA), and the Gene Expression Omnibus (GEO) databases. Based on the mRNA expression of HOXD10, GBM patients from TCGA database were divided into low- and high-HOXD10 expression groups to analyze the Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways, and construct a lncRNA-miRNA-mRNA network and a protein–protein interaction (PPI) network.

Results

The mRNA expression of HOXD10 was up-regulated in GBM according to GEPIA, while the protein expression of HOXD10 in GBM was down-regulated according to IHC analysis of samples from patients collected from our hospital. Correlation analysis showed that HOXD10 expression was significantly related to IDH1 status. Univariate analysis revealed that low HOXD10 expression, complete surgical resection, postoperative radiotherapy, postoperative temozolomide chemotherapy and IDH1 mutation were all beneficial prognostic factors. Further multivariate analysis revealed that only complete surgical resection and postoperative radiotherapy were independent prognostic factors. GO and KEGG enrichment analyses indicated that HOXD10 expression is mainly involved in cytokine-cytokine receptor interactions. In the ceRNA network, 89 nodes, containing 45 mRNAs, 39 miRNAs and five lncRNAs associated with prognosis were involved. The PPI network revealed a tight interaction between HOXD10 and HOXD8, HOXD9, HOXD11, HOXD13 and HOXB3.

Conclusion

Based on our experimental data, although HOXD10 expression is low in GBM compared with normal brain tissue, GBM patients with high HOXD10 expression have a worse prognosis. HOXD10 may play different or even opposite roles in different stages of GBM occurrence and development. For patients with GBM, HOXD10 may be a valid predictor of prognosis.

MeCP2 drives hepatocellular carcinoma progression via enforcing HOXD3 promoter methylation and expression through the HB-EGF/EGFR pathway

Homeobox D3 (HOXD3), a member of the homeobox family, was described to regulate tumorigenesis, invasion, metastasis, and angiogenesis in various tumor types. However, the molecular mechanisms regulating HOXD3 during hepatocellular carcinoma (HCC) migration, invasion, and angiogenesis remain elusive. In this study, we demonstrated that HOXD3 expression is enhanced by the binding of methyl-CpG-binding protein 2 (MeCP2), a methyl-CpG binding protein, together with CREB1to the hypermethylated promoter of HOXD3. Inhibition of HOXD3 eliminated the tumorigenic effects of MeCP2 on HCC cells. Furthermore, HOXD3 directly targeted the promoter region of heparin-binding epidermal growth factor (HB-EGF) via the EGFR-ERK1/2 cell signaling pathway and promoted invasion, metastasis, and angiogenesis of HCC in vitro and in vivo. Additionally, elevated expression of MeCP2, CREB1, and HB-EGF in HCC correlated with a poor survival rate. Our findings reveal the function of the MeCP2/HOXD3/HB-EGF regulatory axis in HCC, rendering it an attractive candidate for the development of targeted therapeutics and as a potential biomarker in patients with HCC.

Overexpression of HOXA10 promotes the growth and metastasis of nasopharyngeal carcinoma

Deregulation of HOX transcription factor family has frequently been observed in multiple human cancers; however, their role in nasopharyngeal carcinoma remains largely unclear. In the present study, we found that HOX gene family is consistently upregulated in nasopharyngeal carcinoma and identified HOXA10 as one of the mostly upregulated HOX genes. Importantly, we show that HOXA10 overexpression is associated with transcriptional activation of multiple oncogenes essential for nasopharyngeal carcinoma carcinogenesis, including S-phase kinase-associated protein 2 (SKP2), calcium/calmodulin-dependent protein kinase kinase 2 (CAMKK2), and matrix metalloproteinase 1 (MMP1). Mechanistically, the overexpression of SKP2 induces the degradation of cell cycle inhibitor p27, leading to rapid cell cycle progression and cell proliferation. The overexpression of CAMKK2 is associated with enhanced mTOR signaling activity to meet the increased demand for proteins synthesis in rapid growing nasopharyngeal carcinoma cells. Moreover, MMP1 overexpression facilitates nasopharyngeal carcinoma cell migration and invasion and contributes to cancer metastasis and progression. We thus concluded that HOXA10 overexpression promotes the growth and metastasis of nasopharyngeal carcinoma by transcriptionally activating various oncogenic pathways.

Context-dependent HOX transcription factor function in health and disease

During animal development, HOX transcription factors determine the fate of developing tissues to generate diverse organs and appendages. The power of these proteins is striking: mis-expressing a HOX protein causes homeotic transformation of one body part into another. During development, HOX proteins interpret their cellular context through protein interactions, alternative splicing, and post-translational modifications to regulate cell proliferation, cell death, cell migration, cell differentiation, and angiogenesis. Although mutation and/or mis-expression of HOX proteins during development can be lethal, changes in HOX proteins that do not pattern vital organs can result in survivable malformations. In adults, mutation and/or mis-expression of HOX proteins disrupts their gene regulatory networks, deregulating cell behaviors and leading to arthritis and cancer. On the molecular level, HOX proteins are composed of DNA binding homeodomain, and large regions of unstructured, or intrinsically disordered, protein sequence. The primary roles of HOX proteins in arthritis and cancer suggest that mutations associated with these diseases in both the structured and disordered regions of HOX proteins can have substantial functional effects. These insights lead to new questions critical for understanding and manipulating HOX function in physiological and pathological conditions.

Long Non-coding RNAs Involved in Resistance to Chemotherapy in Ovarian Cancer

Ovarian cancer (OC) accounts for more than 150,000 deaths worldwide every year. Patients are often diagnosed at an advanced stage with metastatic dissemination. Although platinum- and taxane-based chemotherapies are effective treatment options, they are rarely curative and eventually, the disease will progress due to acquired resistance. Emerging evidence suggests a crucial role of long non-coding RNAs (lncRNAs) in the response to therapy in OC. Transcriptome profiling studies using high throughput approaches have identified differential expression patterns of lncRNAs associated with disease recurrence. Furthermore, several aberrantly expressed lncRNAs in resistant OC cells have been related to increased cell division, improved DNA repair, up-regulation of drug transporters or reduced susceptibility to apoptotic stimuli, supporting their involvement in acquired resistance. In this review, we will discuss the key aspects of lncRNAs associated with the development of resistance to platinum- and taxane-based chemotherapy in OC. The molecular landscape of OC will be introduced, to provide a background for understanding the role of lncRNAs in the acquisition of malignant properties. We will focus on the interplay between lncRNAs and molecular pathways affecting drug response to evaluate their impact on treatment resistance. Additionally, we will discuss the prospects of using lncRNAs as biomarkers or targets for precision medicine in OC. Although there is still plenty to learn about lncRNAs and technical challenges to be solved, the evidence of their involvement in OC and the development of acquired resistance are compelling and warrant further investigation for clinical applications.

SNHG16 Silencing Inhibits Neuroblastoma Progression by Downregulating HOXA7 via Sponging miR-128-3p

Neuroblastoma (NB) is a common intracranial solid tumor with high mortality. Small nucleolar RNA host gene 16 (SNHG16), one of the long noncoding RNAs (lncRNAs), has been reported to be linked to the poor prognosis of NB. However, the mechanisms of SNHG16 in regulating NB progression remain poorly understood. The expression level of SNHG16 was measured by quantitative real time polymerase chain reaction (qRT-PCR). The starBase was employed to predict the interaction of miR-128-3p and SNHG16 or HOXA7, which was verified by dual-luciferase reporter assay and RNA immunoprecipitation (RIP) assay. Cell proliferation and apoptosis were assessed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and flow cytometry, respectively. Transwell assay was used to detect cell invasion or migration. The mRNA and protein levels of homeobox protein A7 (HOXA7) were determined by qRT-PCR and western blot, respectively. The levels of SNHG16 and HOXA7 were conspicuously increased in NB tissues and cells, while the expression of miR-128-3p was obviously declined, compared with corresponding normal tissues and cells. SNHG16 silencing inhibited proliferation, migration and invasion and induced apoptosis of NB cells. We identified that SNHG16 directly interacted with miR-128-3p, and miR-128-3p could target the 3'UTR of HOXA7 in NB cells. Simultaneously, miR-128-3p expression was negatively associated with SNHG16 or HOXA7. Further studies indicated that SNHG16 overexpression rescued the effects of miR-128-3p-mediated on inhibiting proliferation, migration, invasion and promoting apoptosis of NB cells. Moreover, SNHG16 could modulate HOXA7 by sponging miR-128-3p in NB cells. Besides, SNHG16 silencing suppressed tumor growth in vivo. Knockdown of SNHG16 impeded proliferation, migration, invasion and induced apoptosis through the SNHG16/miR-128-3p/HOXA7 axis in NB cells.

Circulating HOXA9-methylated tumour DNA: A novel biomarker of response to poly (ADP-ribose) polymerase inhibition in BRCA-mutated epithelial ovarian cancer

AIM

Poly (ADP-ribose) polymerase (PARP) inhibitors have emerged as a novel treatment option in BRCA-mutated ovarian cancer (OC); however, responses are variable and there is a lack of prognostic and predictive biomarkers. We therefore investigated whether homeobox A9 (HOXA9) promoter methylation in circulating tumour DNA (meth-ctDNA) can serve as a biomarker in patients with platinum-resistant BRCA-mutated OC, undergoing treatment with a PARP inhibitor.

METHODS

Patients (n = 32) were enrolled as part of a phase II trial testing veliparib in platinum-resistant BRCA-mutated OC. HOXA9 meth-ctDNA was determined at baseline and just before each treatment cycle using digital droplet polymerase chain reaction. Methylation status and change in methylation compared with baseline were correlated with overall survival (OS) and progression-free survival (PFS).

RESULTS

Detection of HOXA9 meth-ctDNA during treatment with a PARP inhibitor was associated with worse clinical outcomes. This association was apparent after the first cycle of treatment and maintained throughout treatment. After three treatment cycles, patients with detectable HOXA9 meth-ctDNA had a median PFS of 5.1 months compared with 8.3 months for patients without, and a median OS of 9.5 months compared with 19.4 months (p < 0.0001 and p = 0.002, respectively). Patients with detectable HOXA9 meth-ctDNA at baseline, but subsequent undetectable levels, had the most favourable clinical outcome, followed by patients with undetectable levels throughout. These associations were maintained in multivariate analysis.

CONCLUSIONS

Longitudinal monitoring of HOXA9 meth-ctDNA is clinically feasible and is strongly correlated to clinical outcomes (PFS, OS), suggesting that it may serve as a valuable predictive biomarker to inform clinical decision-making in the setting of platinum-resistant BRCA-mutated OC treated with a PARP inhibitor.

HOX Genes in High Grade Ovarian Cancer

HOX genes are highly conserved members of the homeobox superfamily that have a crucial role in determining cellular identity. High grade ovarian cancer is the most lethal gynaecological malignancy. Our understanding of the role of HOX genes in the oncogenesis of ovarian cancer is evolving, and here we review their dysregulated expression patterns, their function in cell survival and invasion, their potential uses as biomarkers, and ways in which HOX genes are being targeted with new and existing drugs.

Osteopontin, Macrophage Migration Inhibitory Factor and Anti-Interleukin-8 Autoantibodies Complement CA125 for Detection of Early Stage Ovarian Cancer

Early detection of ovarian cancer promises to reduce mortality. While serum CA125 can detect more than 60% of patients with early stage (I–II) disease, greater sensitivity might be observed with a panel of biomarkers. Ten protein antigens and 12 autoantibody biomarkers were measured in sera from 76 patients with early stage (I–II), 44 patients with late stage (III–IV) ovarian cancer and 200 healthy participants in the normal risk ovarian cancer screening study. A four-biomarker panel (CA125, osteopontin (OPN), macrophage inhibitory factor (MIF), and anti-IL-8 autoantibodies) detected 82% of early stage cancers compared to 65% with CA125 alone. In early stage subjects the area under the receiver operating characteristic curve (AUC) for the panel (0.985) was significantly greater (p < 0.001) than the AUC for CA125 alone (0.885). Assaying an independent validation set of sera from 71 early stage ovarian cancer patients, 45 late stage patients and 131 healthy women, AUC in early stage disease was improved from 0.947 with CA125 alone to 0.974 with the four-biomarker panel (p = 0.015). Consequently, OPN, MIF and IL-8 autoantibodies can be used in combination with CA125 to distinguish ovarian cancer patients from healthy controls with high sensitivity. Osteopontin appears to be a robust biomarker that deserves further evaluation in combination with CA125.

Homeoprotein DLX4 expression is increased in inflammatory breast cancer cases from an urban African-American population

Protein expression of Distal-less homeobox 4 (DLX4) was analyzed in inflammatory breast cancer (IBC) cases from an African-American (AA) population to determine if a) DLX4 gene over expression exists in this cohort and b) if the overexpression is associated with breast cancer clinicopathological characteristics (ER, PR, HER2, triple-negative). Twenty-nine blocks of formalin-fixed paraffin-embedded (FFPE) tissue from well-characterized human IBC cases were used for immunohistochemical staining (IHC). IHC results were assigned an intensity and percentage score. Percentage scores were assigned as 0, 1, 2, 3, or 4 and intensity scores were assigned 0, 1+, 2+ or 3+. For the analysis of the IHC, a percentage score of 3 or 4 and an intensity score of 2+ or 3+ were categorized as high. Chi-square or Fisher's exact tests were used to compare the high and low groups. In this cohort, 89.7% (26 out of 29) of IBC cases showed high percentages of positive cells staining for the DLX4 protein, while 40.0% (12 out of 30) of normal breast tissue from reduction mammoplasty cases demonstrated DLX4 expression (p < 0.01). In IBC patients, 65.5% of cases showed a high level of staining intensity, compared to 20.0% of normal breast tissues (test, p = 0.001). Intensity to DLX4 was higher in the HER2 negative status (78.3%) than the HER2 positive status (16.7%) (test, p = 0.011). DLX4 expression is higher in the IBC cases in this study of an urban AA population than in normal breast tissue cases. HER2 negative status is positively associated with high intensity of DLX4.

The effect of lncRNA HOTAIR on chemoresistance of ovarian cancer through regulation of HOXA7

This study aimed at investigating the biological functions of long non-coding RNAs (lncRNAs) hox transcript antisense intergenic RNA (HOTAIR) in resistant ovarian cancer cells, exploring the regulation effect of HOTAIR on HOXA7, and investigating their influence on the chemosensitivity of ovarian cancer cells. Quantitative real-time polymerase chain reaction (qRT-PCR) was applied for the verification of HOTAIR expression in resistant and sensitive groups. How HOTAIR downregulation affected cell proliferation, migration and invasion, and apoptosis were determined using the MTT assay and the colony formation assay, the Transwell assay and flow cytometry analysis, respectively. Immunohistochemistry was used to inspect the protein expression of HOXA7 in resistant and sensitive ovarian cancer tissues. The regulation relationship between HOTAIR and HOXA7 was investigated by qRT-PCR and Western blot. The effect of HOTAIR and HOXA7 on tumor growth was confirmed by the tumor xenograft model of nude mice. By knocking down HOXA7, HOTAIR downregulation restrained the ovarian cancer deterioration in functional experiments. Silencing of HOTAIR and HOXA7 could effectively inhibit tumor growth and increase chemosensitivity of ovarian tumors in nude mice. Downregulation of HOTAIR negatively affected the survival and activity of resistant ovarian cancer cells, and suppressed the expression of HOXA7. Silencing of HOTAIR and HOXA7 could increase the chemosensitivity of ovarian cancer cells, thus suppressing tumor development.

Systematic review: Tumor-associated antigen autoantibodies and ovarian cancer early detection

OBJECTIVES

Tumor-associated autoantibodies (AAbs), produced as an immune response to tumor-associated antigens (TAAs), are a novel pathway of early detection markers.

METHODS

We conducted a systematic review on AAbs and ovarian cancer to summarize the diagnostic performance of individual AAbs and AAb panels. A total of 29 studies including 85 AAbs were included; 27 of the studies were conducted in prevalent cases and cancer-free controls and 2 investigations included pre-diagnosis samples. The majority of studies were hypothesis-driven, evaluating AAbs to target TAAs; 10 studies used screening approaches such as serological expression cloning (SEREX) and nucleic acid-programmable protein arrays (NAPPA).

RESULTS

The highest sensitivities for individual AAbs were reported for RhoGDI-AAbs (89.5%) and TUBA1C-AAbs (89%); however, specificity levels were relatively low (80% and 75%, respectively). High sensitivities at high specificities were reported for HOXA7-AAbs for detection of moderately differentiated ovarian tumors (66.7% sensitivity at 100% specificity) and IL8-AAbs in stage I-II ovarian cancer (65.5% sensitivity at 98% specificity). A panel of 11 AAbs (ICAM3, CTAG2, p53, STYXL1, PVR, POMC, NUDT11, TRIM39, UHMK1, KSR1, and NXF3) provided 45% sensitivity at 98% specificity for serous ovarian cancer, when at least 2 AAbs were above a threshold of 95% specificity. Twelve of the AAbs identified in this review were investigated in more than one study. Data on diagnostic discrimination by tumor histology and stage at diagnosis are sparse. Limited data suggest select AAb markers improve diagnostic discrimination when combined with markers such as CA125 and HE4.

CONCLUSIONS

AAbs for ovarian cancer early detection is an emerging area, and large-scale, prospective investigations considering histology and stage are required for discovery and validation. However, data to date suggests panels of AAbs may eventually reach sufficient diagnostic discrimination to allow earlier detection of disease as a complement to existing markers and transvaginal ultrasound.

Dysregulated expression of homeobox family genes may influence survival outcomes of patients with epithelial ovarian cancer: analysis of data from The Cancer Genome Atlas

Homeobox (HOX) family genes encode key transcription factors for embryogenesis and may be correlated with carcinogenesis. The aim of this study was to elucidate whether aberrant expression of HOX genes influences outcomes in epithelial ovarian cancer (EOC). Gene expression data and clinicopathologic information from 630 patients with EOC were downloaded from The Cancer Genome Atlas database. We explored correlations between expression levels of HOX gene family members and clinicopathological variables. Higher expression of HOXA1, A4, A5, A7, A10, A11, B13, C13, D1, and D3 was associated with advanced FIGO stage. Suboptimal residual disease after debulking surgery was significantly correlated with higher expression of HOXB9, B13, and C13. Additionally, patients with high expression of HOXC6 and C11 were significantly more likely to have poor performance status. Overall survival was significantly shorter in patients with high, rather than low, expression of two HOX genes (HOXA10 and B3), and significantly longer in patients with high rather than low HOXC5 expression. Dysregulated expression of the HOXA10, B3, and C5 was significantly correlated with overall survival in EOC patients. HOX gene expression levels are potentially useful as a prognostic indicator in EOC, and HOX genes may represent a novel and promising target for anticancer therapeutics.

A functional variant in HOXA11-AS, a novel long non-coding RNA, inhibits the oncogenic phenotype of epithelial ovarian cancer

The homeobox A (HOXA) region of protein-coding genes impacts female reproductive system embryogenesis and ovarian carcinogenesis. The 5-prime end of HOXA includes three long non-coding RNAs (lncRNAs) (HOXA10-AS, HOXA11-AS, and HOTTIP) that are underexplored in epithelial ovarian cancer (EOC). We evaluated whether common genetic variants in these lncRNAs are associated with EOC risk and/or have functional roles in EOC development. Using genome-wide association study data from 1,201 serous EOC cases and 2,009 controls, an exonic variant within HOXA11-AS, rs17427875 (A>T), was marginally associated with reduced serous EOC risk (OR = 0.88 (95% CI: 0.78-1.01, p = 0.06). Functional studies of ectopic expression of HOXA11-AS minor allele T in EOC cells showed decreased survival, proliferation, migration, and invasion compared to common allele A expression. Additionally, stable expression of HOXA11-AS minor allele T reduced primary tumor growth in mouse xenograft models to a greater extent than common allele A. Furthermore, HOXA11-AS expression levels were significantly lower in human EOC tumors than normal ovarian tissues (p < 0.05), suggesting that HOXA11-AS has a tumor suppressor function in EOC which may be enhanced by the T allele. These findings demonstrate for the first time a role for HOXA11-AS in EOC with effects that could be modified by germline variants.

Integrating Transcriptomic and Proteomic Data Using Predictive Regulatory Network Models of Host Response to Pathogens

Mammalian host response to pathogenic infections is controlled by a complex regulatory network connecting regulatory proteins such as transcription factors and signaling proteins to target genes. An important challenge in infectious disease research is to understand molecular similarities and differences in mammalian host response to diverse sets of pathogens. Recently, systems biology studies have produced rich collections of omic profiles measuring host response to infectious agents such as influenza viruses at multiple levels. To gain a comprehensive understanding of the regulatory network driving host response to multiple infectious agents, we integrated host transcriptomes and proteomes using a network-based approach. Our approach combines expression-based regulatory network inference, structured-sparsity based regression, and network information flow to infer putative physical regulatory programs for expression modules. We applied our approach to identify regulatory networks, modules and subnetworks that drive host response to multiple influenza infections. The inferred regulatory network and modules are significantly enriched for known pathways of immune response and implicate apoptosis, splicing, and interferon signaling processes in the differential response of viral infections of different pathogenicities. We used the learned network to prioritize regulators and study virus and time-point specific networks. RNAi-based knockdown of predicted regulators had significant impact on viral replication and include several previously unknown regulators. Taken together, our integrated analysis identified novel module level patterns that capture strain and pathogenicity-specific patterns of expression and helped identify important regulators of host response to influenza infection.

An important challenge in infectious disease research is to understand how the human immune system responds to different types of pathogenic infections. An important component of mounting proper response is the transcriptional regulatory network that specifies the context-specific gene expression program in the host cell. However, our understanding of this regulatory network and how it drives context-specific transcriptional programs is incomplete. To address this gap, we performed a network-based analysis of host response to influenza viruses that integrated high-throughput mRNA- and protein measurements and protein-protein interaction networks to identify virus and pathogenicity-specific modules and their upstream physical regulatory programs. We inferred regulatory networks for human cell line and mouse host systems, which recapitulated several known regulators and pathways of the immune response and viral life cycle. We used the networks to study time point and strain-specific subnetworks and to prioritize important regulators of host response. We predicted several novel regulators, both at the mRNA and protein levels, and experimentally verified their role in the virus life cycle based on their ability to significantly impact viral replication.

High expression of transcriptional factor HoxB9 predicts poor prognosis in patients with lung adenocarcinoma

AIMS

HoxB9, as a Hox family member, is known to play important roles in embryonic development. Recent studies showed that HoxB9 is engaged in cancer progression. However, the role of Hoxb9 in lung adenocarcinoma is unknown. The purpose of this study is to investigate the expression and prognostic value of HoxB9 in patients with lung adenocarcinoma.

METHODS AND RESULTS

The localization and expression of HoxB9 in lung adenocarcinoma were examined by immunohistochemistry. The correlation between HoxB9 expression levels with patient survival was assessed by Kaplan-Meier analysis. The epithelial-mesenchymal transition (EMT) markers and migratory ability were evaluated in HoxB9 up- and down-regulated H1299 lung adenocarcinoma cells. HoxB9 was found to be localized predominantly in the cell nuclei and expressed in 21.3% of lung adenocarcinomas. A significant increase in HoxB9 intensity in the high stage of lung adenocarcinoma was observed (P < 0.01). Increased expression of HoxB9 was related to T classification, more lymph node metastasis and a shorter patient overall survival (P < 0.05). However, the expression level of HoxB9 was not correlated with age and gender. Functionally, HoxB9 up-regulated EMT-related molecules and promoted cell migration in H1299 cells.

CONCLUSION

High expression of HoxB9 is a prognostic marker for lung adenocarcinoma patients.

Inhibition of non-small-cell lung cancer cell proliferation by Pbx1

Lung cancer is one of the most deadly human cancers and continues to be a major unsolved health problem worldwide. Here, we evaluate the function of Pbx1 in the proliferation of non-small-cell lung cancer (NSCLC). In contrast with its known proliferative function, we found that Pbx1 inhibits the proliferation of lung cancer cells. In particular, Pbx1-specific RNA interference resulted in increased proliferation in lung cancer cells. In addition, histone H3 phosphorylation was also increased following inhibition of Pbx1 expression. In contrast, Pbx1 overexpression repressed the proliferation of lung cancer cells and inhibited DNA synthesis. Collectively, our data indicate that Pbx1 inhibits proliferation in lung cancer cells, suggesting a complex role for Pbx1 in modulating the proliferation of cancer cells and making this protein a potential new target for lung cancer therapy.

Mutation screening of HOXA7 and HOXA9 genes in Chinese women with Müllerian duct abnormalities

HOXA genes in groups 7-13 have been proven to play a role in determining positional identity along the genitalia axis. The aim of the present study was to explore the relationship between HOXA7 and HOXA9 mutations and Müllerian duct abnormalities (MDA). One hundred and ninety-two Chinese patients with MDA abnormalities and 192 healthy controls were recruited. All coding regions of HOXA7 and HOXA9 were amplified and sequenced directly. Rs2301721 and rs2301720 in HOXA7, rs35355140 and rs7810502 in HOXA9 were identified in patients with MDA and controls. One rare single nucleotide polymorphism rs189587233 in 3' UTR of HOXA9 gene was detected in one patient with didelphic uterus and absent in the 192 controls. This polymorphism, however, is known to exist in the normal Chinese population. Our results indicated that variants in the HOXA7 and HOXA9 genes were not common in Chinese women with Müllerian duct abnormalities.

Hox transcription factors: modulators of cell-cell and cell-extracellular matrix adhesion

Hox genes encode homeodomain-containing transcription factors that determine cell and tissue identities in the embryo during development. Hox genes are also expressed in various adult tissues and cancer cells. In Drosophila, expression of cell adhesion molecules, cadherins and integrins, is regulated by Hox proteins operating in hierarchical molecular pathways and plays a crucial role in segment-specific organogenesis. A number of studies using mammalian cultured cells have revealed that cell adhesion molecules responsible for cell-cell and cell-extracellular matrix interactions are downstream targets of Hox proteins. However, whether Hox transcription factors regulate expression of cell adhesion molecules during vertebrate development is still not fully understood. In this review, the potential roles Hox proteins play in cell adhesion and migration during vertebrate body patterning are discussed.

HOX genes and their role in the development of human cancers

In this review, we summarize published findings on the involvement of HOX genes in oncogenesis. HOX genes are developmental genes--they code for proteins that function as critical master regulatory transcription factors during embryogenesis. Many reports have shown that the protein products of HOX genes also play key roles in the development of cancers. Based on our review of the literature, we found that the expression of HOX genes is not only up- or downregulated in most solid tumors but also that the expression of specific HOX genes in cancers tends to differ based on tissue type and tumor site. It was also observed that HOXC family gene expression is upregulated in most solid tumor types, including colon, lung, and prostate cancer. The two HOX genes that were reported to be most commonly altered in solid tumors were HOXA9 and HOXB13. HOXA were often reported to have altered expression in breast and ovarian cancers, HOXB genes in colon cancers, HOXC genes in prostate and lung cancers, and HOXD genes in colon and breast cancers. It was found that HOX genes are also regulated at the nuclear-cytoplasmic transport level in carcinomas. Tumors arising from tissue having similar embryonic origin (endodermal), including colon, prostate, and lung, showed relatively similar HOXA and HOXB family gene expression patterns compared to breast tumors arising from mammary tissue, which originates from the ectoderm. The differential expression of HOX genes in various solid tumors thus provides an opportunity to advance our understanding of cancer development and to develop new therapeutic agents.

Homeobox A7 stimulates breast cancer cell proliferation by up-regulating estrogen receptor-alpha

Breast cancer is the most common hormone-dependent malignancy in women. Homeobox (HOX) transcription factors regulate many cellular functions, including cell migration, proliferation and differentiation. The aberrant expression of HOX genes has been reported to be associated with human reproductive cancers. Estradiol (E2) and its nuclear receptors, estrogen receptor (ER)-alpha and ER-beta, are known to play critical roles in the regulation of breast cancer cell growth. However, an understanding of the potential relationship between HOXA7 and ER in breast cancer cells is limited. In this study, our results demonstrate that knockdown of HOXA7 in MCF7 cells significantly decreased cell proliferation and ERα expression. In addition, HOXA7 knockdown attenuated E2-induced cell proliferation as well as progesterone receptor (PR) expression. The stimulatory effects of E2 on cell proliferation and PR expression were abolished by co-treatment with ICI 182780, a selective ERα antagonist. In contrast, overexpression of HOXA7 significantly stimulated cell proliferation and ERα expression. Moreover, E2-induced cell proliferation, as well as PR expression, was enhanced by the overexpression of HOXA7. Neither knockdown nor overexpression of HOXA7 affected the ER-beta levels. Our results demonstrate a novel mechanistic role for HOXA7 in modulating breast cancer cell proliferation via regulation of ERα expression. This finding contributes to our understanding of the role HOXA7 plays in regulating the proliferation of ER-positive cancer cells.

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.

HOXB8 expression in ovarian serous carcinoma effusions is associated with shorter survival

OBJECTIVE

HOX proteins are key transcription factors in embryogenesis. HOXB5 and HOXB8 were previously shown to be overexpressed in ovarian/primary peritoneal serous carcinoma compared to breast carcinoma using gene expression arrays. The present study investigated the clinical role of HOXB5 and HOXB8 in advanced-stage (FIGO III-IV) ovarian serous carcinoma.

METHODS

HOXB5 and HOXB8 protein expression was analyzed in 286 effusions and 76 patient-matched solid lesions (27 primary carcinomas, 49 metastases) using immunohistochemistry. Expression was analyzed for association with clinicopathologic parameters, including survival.

RESULTS

Cytoplasmic HOXB5 protein was detected in 268/286 (94%) effusions. HOXB8 was expressed at both the cytoplasm (252/286; 88%) and nucleus (131/286; 46%) of carcinoma cells. Cytoplasmic HOXB5, cytoplasmic HOXB8 and nuclear HOXB8 were found in 56/76 (74%), 76/76 (100%) and 30/76 (39%) solid lesions, respectively, with significantly higher HOXB5 expression in effusions (p=0.002) and higher cytoplasmic HOXB8 in solid lesions (p<0.001). HOXB5 expression was higher in post-chemotherapy disease recurrence effusions compared to pre-chemotherapy effusions tapped at diagnosis (p=0.04). In univariate survival analysis of the effusion cohort, higher expression of cytoplasmic HOXB8 was associated with significantly shorter progression-free survival (p=0.033), whereas higher nuclear HOXB8 expression was associated with significantly shorter overall survival in analysis limited to patients with post-chemotherapy effusions (p=0.036). Neither finding was independent prognostic factor in Cox multivariate analysis.

CONCLUSIONS

HOXB5 and HOXB8 are frequently expressed in ovarian serous carcinoma, with anatomic site-related differences for cytoplasmic staining. HOXB5 may be affected by chemotherapy in effusions. HOXB8 expression is associated with shorter survival in metastatic serous carcinoma.

Cancer-testis antigen BORIS is a novel prognostic marker for patients with esophageal cancer

Esophageal squamous cell cancer (ESCC) is one of the most common lethal tumors in the world, and development of new diagnostic and therapeutic methods is needed. In this study, cancer-testis antigen, BORIS, was isolated by functional cDNA expression cloning using screening technique with serum IgG Abs from ESCC patients. BORIS was previously reported to show cancer-testis antigen like expression, but its immunogenicity has remained unclear in cancer patients. BORIS was considered to be an immunogenic antigen capable of inducing IgG Abs in patients with various cancers, including four of 11 ESCC patients. Immunohistochemical study showed that the BORIS protein was expressed in 28 of 50 (56%) ESCC tissues. The BORIS expression was significantly associated with lymph node metastasis in ESCC patients with pT1 disease (P = 0.036). Furthermore, the patients with BORIS-positive tumors had a poor overall survival (5-year survival rate: BORIS-negative 70.0% vs BORIS-positive 29.9%, log-rank P = 0.028) in Kaplan-Meier survival analysis and log-rank test. Multivariate Cox proportional hazard model demonstrated that BORIS expression was an independent poor prognostic factor (hazard ratio = 4.158 [95% confidence interval 1.494-11.57], P = 0.006). Downregulation of BORIS with specific siRNAs resulted in decreased cell proliferation and invasion ability of ESCC cell lines. BORIS may be a useful biomarker for prognostic diagnosis of ESCC patients and a potential target for treatment including by BORIS-specific immunotherapy and molecular target therapy.

A novel cancer/testis antigen KP-OVA-52 identified by SEREX in human ovarian cancer is regulated by DNA methylation

SEREX has proven to be a powerful method that takes advantage of the presence of spontaneous humoral immune response in some cancer patients. In this study, immunoscreening of normal testis and two ovarian cancer cell line cDNA expression libraries with sera from ovarian cancer patients led to the isolation of 75 independent antigens, designated KP-OVA-1 through KP-OVA-75. Of these, RT-PCR showed KP-OVA-52 to be expressed strongly in normal testis, in ovarian cancer cell lines (3/9) and in ovarian cancer tissues (1/17). The expression of KP-OVA-52 in cancer cells is also induced by the demethylating agent 5-aza-2′-deoxycytidine (ADC). To test immunogenicity, we used the Serum Antibody Detection Assay (SADA) to analyze anti-IgG antibodies against the 75 antigens that were initially isolated by SEREX. Four of the 75 antigens (KP-OVA-25, KP-OVA-35, KP-OVA-68 and KP-OVA-73) reacted exclusively with sera from cancer patients. However, KP-OVA-52 reacted with 1 of 20 ovarian cancer sera. These data suggest that the KP-OVA-52 can be considered a novel CT antigen that is regulated by DNA methylation.

The loss of Hoxa5 function causes estrous acyclicity and ovarian epithelial inclusion cysts

Hox genes encode transcription factors that play essential roles during embryo morphogenesis and organogenesis. Expression of several Hox members persists at the adult age, indicating a wide spectrum of action from embryonic to postnatal life. In the present study, we reported that in adult mice, the Hoxa5 gene shows a dynamic expression profile in the ovary that depends on the estrous cycle, the gestational status, and the age of the female, suggesting that Hoxa5 may have distinct physiological functions in the ovary. Consistent with a role for Hoxa5 in ovarian function, Hoxa5(-/-) nulliparous females exhibit precocious puberty and an early onset of estrous acyclicity. They show a prolonged estrous cycle with increased metestrus-diestrus length, a phenotype that worsens with age. Older mutant females also develop ovarian epithelial inclusion cysts reminiscent of human endosalpingiosis. Immunolabeling studies suggest that these cysts originate from the ovarian surface epithelium, a source of epithelial ovarian carcinomas. Staining of the Hoxa5(-/-) ovarian cysts by the ovarian cancer markers paired box gene 8 (PAX8) and Wilms' tumor 1 (WT1) further strengthens the notion that these cysts may constitute preneoplastic lesions. Moreover, the deregulation of the estrous cycle and the presence of ovarian epithelial cysts in Hoxa5(-/-) older females correlate with a reduced expression of specific epidermal growth factor receptor signaling components, namely Egfr, Areg, and Btc. Altogether, our data unveil that Hoxa5, a stroma-specific gene, plays a significant role in ovarian biology and may be involved in ovarian cancer predisposition.

HOX genes in ovarian cancer

The HOX genes are a family of homeodomain-containing transcription factors that determine cellular identity during development. Here we review a number of recent studies showing that HOX genes are strongly expressed in ovarian cancer, and that in some cases the expression of specific HOX genes is sufficient to confer a particular identity and phenotype upon cancer cells. We also review the recent advances in elucidating the different functions of HOX genes in ovarian cancer. A literature search was performed using the search terms HOX genes (including specific HOX genes), ovarian cancer and oncogenesis. Articles were accessed through searches performed in ISI Web of Knowledge, PubMed and ScienceDirect. Taken together, these studies have shown that HOX genes play a role in the oncogenesis of ovarian cancer and function in the inhibition of apoptosis, DNA repair and enhanced cell motility. The function of HOX genes in ovarian cancer oncogenesis supports their potential role as prognostic and diagnostic markers, and as therapeutic targets in this disease.

Peptide mimic isolated by autoantibody reveals human arrest defective 1 overexpression is associated with poor prognosis for colon cancer patients

Tumor-associated antigens, which induce the generation of autoantibodies, are useful as cancer biomarkers in early detection and prognostic prediction of cancer. To isolate a novel cancer marker, we used serum antibodies from colon cancer patients to screen a phage display peptide library. A positive peptide 249C (VPLYSNTLRYGF) that could specifically react with serum from colon cancer patients was isolated, and the corresponding antigen-human arrest defective 1 (ARD1A), which shares an identical LYSNTL motif with 249C, was identified. Both immunological assays and three-dimensional structure analysis showed that the LYSNTL region is an epitope of ARD1A. Using ELISA and immunohistochemistry, we found anti-ARD1A antibody levels in serum from patients with colon cancer were significantly higher than those in healthy volunteers (P < 0.001), and ARD1A expression was detected in 84.1% (227/270) of colon cancer tissues compared with 22.7% (55/242) of matched noncancerous tissues (P < 0.001) and 4.8% (2/42) of benign lesions (P < 0.001). Furthermore, multivariate analysis with Cox proportional hazards regression models revealed that ARD1A-positive patients had significantly shortened overall survival (OS) (HR, 1.91, P = 0.039) and borderline significantly shortened disease-free survival (DFS) (HR, 1.70; P = 0.068). Kaplan-Meier survival curves also showed that ARD1A expression was associated significantly with shortened DFS (P = 0.037) and OS (P = 0.019). These results indicate that ARD1A is a novel tumor-associated antigen and a potential prognostic factor for colon cancer.

Homeobox A7 increases cell proliferation by up-regulation of epidermal growth factor receptor expression in human granulosa cells

BACKGROUND

Homeobox (HOX) genes encode transcription factors, which regulate cell proliferation, differentiation, adhesion, and migration. The deregulation of HOX genes is frequently associated with human reproductive system disorders. However, knowledge regarding the role of HOX genes in human granulosa cells is limited.

METHODS

To determine the role of HOXA7 in the regulation and associated mechanisms of cell proliferation in human granulosa cells, HOXA7 and epidermal growth factor receptor (EGFR) expressions were examined in primary granulosa cells (hGCs), an immortalized human granulosa cell line, SVOG, and a granulosa tumor cell line, KGN, by real-time PCR and Western blotting. To manipulate the expression of HOXA7, the HOXA7 specific siRNA was used to knockdown HOXA7 in KGN. Conversely, HOXA7 was overexpressed in SVOG by transfection with the pcDNA3.1-HOAX7 vector. Cell proliferation was measured by the MTT assay.

RESULTS

Our results show that HOXA7 and EGFR were overexpressed in KGN cells compared to hGCs and SVOG cells. Knockdown of HOXA7 in KGN cells significantly decreased cell proliferation and EGFR expression. Overexpression of HOXA7 in SVOG cells significantly promoted cell growth and EGFR expression. Moreover, the EGF-induced KGN proliferation was abrogated, and the activation of downstream signaling was diminished when HOXA7 was knocked down. Overexpression of HOXA7 in SVOG cells had an opposite effect.

CONCLUSIONS

Our present study reveals a novel mechanistic role for HOXA7 in modulating granulosa cell proliferation via the regulation of EGFR. This finding contributes to the knowledge of the pro-proliferation effect of HOXA7 in granulosa cell growth and differentiation.

Expression pattern of the class I homeobox genes in ovarian carcinoma

OBJECTIVE

Although some sporadic reports reveal the link between the homeobox (HOX) genes and ovarian carcinoma, there is no comprehensive analysis of the expression pattern of the class I homeobox genes in ovarian carcinoma that determines the candidate genes involved in ovarian carcinogenesis.

METHODS

The different patterns of expression of 36 HOX genes were analyzed, including 4 ovarian cancer cell lines and 4 normal ovarian tissues. Using a reverse transcription-polymerase chain reaction (RT-PCR) and quantification analysis, the specific gene that showed a significantly higher expression in ovarian cancer cell lines than in normal ovaries was selected, and western blot analysis was performed adding 7 ovarian cancer tissue specimens. Finally, immunohistochemical and immunocytochemical analyses were performed to compare the pattern of expression of the specific HOX gene between ovarian cancer tissue and normal ovaries.

RESULTS

Among 36 genes, 11 genes had a different level of mRNA expression between the cancer cell lines and the normal ovarian tissues. Of the 11 genes, only HOXB4 had a significantly higher level of expression in ovarian cancer cell lines than in normal ovaries (p=0.029). Based on western blot, immunohistochemical, and immunocytochemical analyses, HOXB4 was expressed exclusively in the ovarian cancer cell lines or cancer tissue specimens, but not in the normal ovaries.

CONCLUSION

We suggest HOXB4 may be a novel candidate gene involved in ovarian carcinogenesis.

Autoantibodies to tumor-associated antigens in epithelial ovarian carcinoma

This review will focus on recent knowledge related to circulating autoantibodies (AAbs) to tumor-associated antigens (TAAs) in epithelial ovarian carcinoma. So far, the following TAAs have been identified to elicit circulating AAbs in epithelial ovarian carcinoma: p53, homeobox proteins (HOXA7, HOXB7), heat shock proteins (HSP-27, HSP-90), cathepsin D, cancer-testis antigens (NY-ESO-1/LAGE-1), MUC1, GIPC-1, IL-8, Ep-CAM, and S100A7. Since AAbs to TAAs have been identified in the circulation of patients with early-stage cancer, it has been speculated that the assessment of a panel of AAbs specific for epithelial ovarian carcinoma TAAs might hold great potential as a novel tool for early diagnosis of epithelial ovarian carcinoma.

Proteogenomic studies in epithelial ovarian cancer: established knowledge and future needs

There has been a concerted effort over the last decade to improve our understanding of the complex biology of ovarian cancer. A linear growth in published proteogenomic studies has addressed a variety of questions regarding its molecular pathogenesis. A number of genes have been identified by transcriptomic approaches, some of which are being investigated as putative tumor markers (HE4, OPN, Ep-CAM and Mesothelin), whilst others are potential targets for molecular therapeutic approaches (VEGF, IO4, EGFR, MUC1, CLDN4 and SLPI). Proteogenomics has the potential to further change our current characterization and treatment of ovarian cancer. Additional advances will depend on integrated study designs, interdisciplinary collaborations, use of robust high-throughput platforms, as well as uniform guidelines for bioinformatic analyses.

Prevalence of antitumor antibodies in laying hen model of human ovarian cancer

Antitumor antibodies are associated with tumors in human cancers. There is relatively little information on the timing and progression of antibody response to tumors. The objective of the study was to determine if spontaneous ovarian cancer in the egg-laying hen is associated with antitumor antibodies. Antibodies were detected by immunoassay and immunoblotting using proteins from normal ovary and ovarian tumors. Candidate antigens were identified by mass spectrometry of immunoreactive spots cut from 2-dimensional gels and Western blot. Antitumor (serum reacting against tumor ovarian extract) and antiovarian (serum reacting against normal ovarian extract) antibodies were significantly associated with ovarian cancer (67%; P <or= 0.001) compared with normal control hens. Hens with abnormal histology but no gross tumor had antitumor antibodies (63%; P <or= 0.025) but not antiovarian antibodies. There were common as well as different immunoreactions against normal ovary and homologous and heterologous tumor proteins in 2-dimensional Western blots. The candidate antigens included those commonly associated with human cancers and other diseases such as vimentin, apolipoprotein A1, Annexin II, enolase, DJ-1, and so on. The results suggest that antitumor antibodies are associated with ovarian cancer in hens, similar to human ovarian cancer. The egg-laying hen may be a model for understanding the antitumor humoral immune response, particularly at early tumor stages that are not readily accessible in human ovarian cancer.

Cell motility and spreading are suppressed by HOXA4 in ovarian cancer cells: possible involvement of beta1 integrin

HOX genes are transcription factors that control morphogenesis, organogenesis and differentiation. Increasing evidence suggests that HOX genes play a role in ovarian cancer progression; however few studies have defined functional roles and mechanisms of action. We showed previously that HOXA4 expression is increased in invasive, compared to noninvasive, epithelial ovarian tumors. However, HOXA4 suppressed cell migration suggesting that elevated HOXA4 expression in invasive tumors constitutes a homeostatic response. In the present study, we used siRNA and forced-expression in multiple cell lines to define the role of HOXA4 in the regulation of transwell migration/invasion and cellular/colony morphology. Knockdown of endogenous HOXA4 increased migration, but not Matrigel invasion, of OVCAR-8 and OVCAR-3 cells. HOXA4 knockdown also increased cell spreading on plastic or fibronectin, reduced cell-cell adhesion, and increased filopodia in two- and three-dimensional cultures. These changes were not associated with significant changes in alphaV or beta3 integrin and E- or N-cadherin. However, down-regulation of HOXA4 significantly reduced beta1 integrin protein levels within cell colonies and cell aggregates, but not of single, nonadherent cells. It had no effect on beta1 integrin, alpha5 integrin, or fibronectin mRNA levels. Conversely, overexpression of HOXA4 in CaOV-3 cells suppressed transwell migration and increased beta1 integrin protein levels. Our results confirm that HOXA4 inhibits cell motility, show that it suppresses cell spreading and filopodia formation while enhancing cell-cell adhesion, and suggest a role for beta1 integrin in mediating these changes. These observations support the hypothesis that overexpression of HOXA4 in invasive ovarian tumors is a homeostatic, invasion-suppressive response.

Identification of tumor-associated antigens by using SEREX in hepatocellular carcinoma

AIM

To identify biomarkers for diagnosis and prognosis of hepatocellular carcinoma (HCC).

METHODS

Screening the HCC cDNA library with HCC patients sera. Isolated proteins were used as antigens to detect antibodies from patients with HCC and control sera.

RESULTS

Eighty-one positive clones were identified. The frequencies of autoantibody against five HCC-associated antigens were higher in HCC than that in chronic hepatitis and normal human sera. The sensitivity and specificity of KRT23, AHSG and FTL antigens combination tests up to 98.2% in joint test and 90.0% in series test separately.

CONCLUSIONS

HCC associate antigens identified from this study supply candidate markers of diagnosis, combined detection and immunotherapy of HCC.

Identification of Pbx1, a potential oncogene, as a Notch3 target gene in ovarian cancer

Notch3 gene amplification has recently been identified in ovarian cancer but the Notch3 effectors that are involved in the development of ovarian cancer remain elusive. In this study, we have identified Pbx1, a proto-oncogene in hematopoietic malignancy, as a Notch3 target gene. Pbx1 expression is transcriptionally regulated by Notch3 activation, and Notch3/CSL protein complex directly binds to the Pbx1 promoter segment harboring the CSL-binding sequence. The growth-inhibitory effect of gamma-secretase inhibitor could be partially reversed by ectopic Pbx1 expression. Furthermore, functional studies by Pbx1 short hairpin RNA knockdown show that Pbx1 is essential for cell proliferation and tumorigenicity. Taken together, the above findings indicate that Pbx1 is a direct Notch3-regulated gene that mediates the survival signal of Notch3 in ovarian cancer.

Expression and function of HOXA genes in normal and neoplastic ovarian epithelial cells

We studied the roles of three HOXA genes in cultured normal ovarian surface epithelial (OSE) cells and ovarian cancer cells. They included HOXA4 and HOXA7 because, by cDNA microarray analysis, these were more highly expressed in invasive ovarian carcinomas than in benign or borderline (noninvasive) ovarian tumors, and HOXA9 because it characterizes normal oviductal epithelium, which resembles ovarian serous adenocarcinomas. The three HOXA genes were more highly expressed when OSE cells were dividing and motile than when they were confluent and stationary, and also when they dispersed in response to EGF treatment or to reduced calcium concentrations in culture media. The expression of the HOXA genes varied among ovarian cancer cell lines, but was highest in lines with compact epithelial morphologies. We focused on HOXA4 as the most highly expressed in the ovarian carcinoma array. HOXA4 expression did not parallel proliferative activities of either OSE or ovarian cancer lines. Moreover, modifying HOXA4 expression in ovarian cancer cell lines did not alter either E-cadherin expression or CA125 secretion. However, HOXA4 downregulation enhanced EGFR phosphorylation and migration in serum-starved OSE and ovarian cancer cells in response to EGF, and enhanced migration of all ovarian cancer lines in 5% serum even without EGF treatment. Thus, HOXA4 expression does not correlate with proliferation or with epithelial differentiation, but it increases in response to OSE cell dispersion and negatively regulates EGFR activation and the motility of OSE and of ovarian cancer cells. HOXA4 expression was highest in cancer lines with compact epithelial growth patterns, suggesting, again, an anti-dispersion function. In summary, increased HOXA4 expression in ovarian cancer appears to constitute a tumor-suppressive, homeostatic response to aberrant cell behavior, and, in particular, to cell dispersion and migration.

Risk factors for ovarian cancer: an overview with emphasis on hormonal factors

Ovarian cancer is the fifth most frequently occurring cancer among women and leading cause of gynecological cancer deaths in North America. Although the etiology of ovarian cancer is not clear, certain factors are implicated in the etiology of this disease, such as ovulation, gonadotropic and steroid hormones, germ cell depletion, oncogenes and tumor suppressor genes, growth factors, cytokines, and environmental agents. Family history of breast or ovarian cancer is a prominent risk factor for ovarian cancer, with 5-10% of ovarian cancers due to heritable risk. Reproductive factors such as age at menopause and infertility contribute to greater risk of ovarian cancer, whereas pregnancy, tubal ligation, and hysterectomy reduce risk. Oral contraceptive (OC) use has clearly been shown to be protective against ovarian cancer. In contrast, large epidemiologic studies found hormone replacement therapy (HRT) to be a greater risk factor for ovarian cancer. The marked influence of hormones and reproductive factors on ovarian cancer suggests that endocrine disrupters may impact risk; however, there is a notable lack of research in this area. Lifestyle factors such as cigarette smoking, obesity, and diet may affect ovarian cancer risk. Exposure to certain environmental agents such as talc, pesticides, and herbicides may increase risk of ovarian cancer; however, these studies are limited. Further research is needed to strengthen the database of information from which an assessment of environmental and toxicological risk factors for ovarian cancer can be made.

HOX gene analysis of endothelial cell differentiation in human bone marrow-derived mesenchymal stem cells

Human bone marrow-derived mesenchymal stem cells (hMSCs) have been shown to possess multilineage differentiation potential. HOX genes function in transcriptional regulators, and are involved in stem cell differentiation. The aim of the present study was to demonstrate HOX genes that are related to angiogenesis. To identify the expression patterns of 37 HOX genes in the endothelial cell differentiation of hMSCs, we analyzed HOX genes through profiling with multiplex RT-PCR. The results showed that the expression patterns of four HOX genes, HOXA7, HOXB3, HOXA3, and HOXB13, significantly changed during angiogenesis. The expression levels of HOXA7 and HOXB3 were dramatically increased, whereas those of HOXA3 and HOXB13 were decreased during endothelial cell differentiation. When further analysis of the expressions of these HOX genes was performed with real-time PCR and an immunoblot assay, the expression patterns were also found to be well-matched with the results of multiplex RT-PCR. Here, we report that HOXA7, HOXB3, HOXA3, and HOXB13 might be involved in the angiogenesis of hMSCs.

HOXB13 promotes ovarian cancer progression

Deregulated expression of HOXB13 in a subset of estrogen receptor-positive breast cancer patients treated with tamoxifen monotherapy is associated with an aggressive clinical course and poor outcome. Because the ovary is another hormone-responsive organ, we investigated whether HOXB13 plays a role in ovarian cancer progression. We show that HOXB13 is expressed in multiple human ovarian cancer cell lines and tumors and that knockdown of endogenous HOXB13 by RNA interference in human ovarian cancer cell lines is associated with reduced cell proliferation. Ectopic expression of HOXB13 is capable of transforming p53(-/-) mouse embryonic fibroblasts and promotes cell proliferation and anchorage-independent growth in mouse ovarian cancer cell lines that contain genetic alterations in p53, myc, and ras. In this genetically defined cell line model of ovarian cancer, we demonstrate that HOXB13 collaborates with activated ras to markedly promote tumor growth in vivo and that HOXB13 confers resistance to tamoxifen-mediated apoptosis. Taken together, our results support a pro-proliferative and pro-survival role for HOXB13 in ovarian cancer.