IGFBP-3 in epithelial ovarian carcinoma and its association with clinico-pathological features and patient survival

Current data and future perspectives on DNA methylation in ovarian cancer (Review)

Ovarian cancer (OC) represents the most prevalent malignancy of the female reproductive system. Its distinguishing features include a high aggressiveness, substantial morbidity and mortality, and a lack of apparent symptoms, which collectively pose significant challenges for early detection. Given that aberrant DNA methylation events leading to altered gene expression are characteristic of numerous tumor types, there has been extensive research into epigenetic mechanisms, particularly DNA methylation, in human cancers. In the context of OC, DNA methylation is often associated with the regulation of critical genes, such as BRCA1/2 and Ras‑association domain family 1A. Methylation modifications within the promoter regions of these genes not only contribute to the pathogenesis of OC, but also induce medication resistance and influence the prognosis of patients with OC. As such, a more in‑depth understanding of DNA methylation underpinning carcinogenesis could potentially facilitate the development of more effective therapeutic approaches for this intricate disease. The present review focuses on classical tumor suppressor genes, oncogenes, signaling pathways and associated microRNAs in an aim to elucidate the influence of DNA methylation on the development and progression of OC. The advantages and limitations of employing DNA methylation in the diagnosis, treatment and prevention of OC are also discussed. On the whole, the present literature review indicates that the DNA methylation of specific genes could potentially serve as a prognostic biomarker for OC and a therapeutic target for personalized treatment strategies. Further investigations in this field may yield more efficacious diagnostic and therapeutic alternatives for patients with OC.

Diabetes and ovarian cancer: risk factors, molecular mechanisms and impact on prognosis

BACKGROUND AND AIM

Diabetes mellitus has been linked to a lower rate of cancer survival and an increase in the incidence of most malignancies. Investigations showed that diabetes might affect ovarian cancer (OC) prognosis and survival. Based on the current information, this study intends to review the risk factors, molecular pathways, and impact of diabetes on OC.

METHODS

The data was derived from online databases, including Web of Science, PubMed, and Scopus. The inclusion criteria were original studies, which included the risk factors, molecular mechanisms, and impact of diabetes on OC. The effect of different antidiabetic drugs was also discussed in this manuscript. All of the clinical, in vivo, and in vitro studies were included in the present study.

RESULTS

The diagnosis of diabetes mellitus negatively affects the survival and prognosis in OC cases. The epidemiologic data shows that the risk of OC increases in patients with diabetes mellitus compared to the healthy population. Insulin-like growth factors family was raised in diabetic patients, which target several mechanisms, including targeting oxidative stress, angiogenesis, and tumor markers. Antidiabetic drugs such as metformin, sitagliptin, and rosiglitazone have a promising effect on elongation of survival and enhancement of prognosis in OC patients.

CONCLUSIONS

Diabetes mellitus is a significant risk factor for OC in women, and it negatively impacts survival and prognosis. Molecular mechanisms such as IGF family, oxidative stress, and inflammatory cytokines have been identified to explain this relationship. Antidiabetic drugs like metformin, sitagliptin, and rosiglitazone have shown promise in improving survival and prognosis of OC patients.

ΔNp63 in squamous cell carcinoma: defining the oncogenic routes affecting epigenetic landscape and tumour microenvironment

Squamous cell carcinoma (SCC) is a treatment‐refractory tumour which arises from the epithelium of diverse anatomical sites such as oesophagus, head and neck, lung and skin. Accumulating evidence has revealed a number of genomic, clinical and molecular features commonly observed in SCC of distinct origins. Some of these genetic events culminate in fostering the activity of ΔNp63, a potent oncogene which exerts its pro‐tumourigenic effects by regulating specific transcriptional programmes to sustain malignant cell proliferation and survival. In this review, we will describe the genetic and epigenetic determinants underlying ΔNp63 oncogenic activities in SCC, and discuss some relevant transcriptional effectors of ΔNp63, emphasizing their impact in modulating the crosstalk between tumour cells and tumour microenvironment (TME).

Insulin-like growth factor-independent insulin-like growth factor binding protein 3 promotes cell migration and lymph node metastasis of oral squamous cell carcinoma cells by requirement of integrin β1

Frequent metastasis to the cervical lymph nodes leads to poor survival of patients with oral squamous cell carcinoma (OSCC). To understand the underlying mechanisms of lymph node metastasis, two sublines were successfully isolated from cervical lymph nodes of nude mice through in vivo selection, and identified as originating from poorly metastatic parental cells. These two sublines specifically metastasized to cervical lymph nodes in 83% of mice, whereas OEC-M1 cells did not metastasize after injection into the oral cavity. After gene expression analysis, we identified insulin-like growth factor binding protein 3 (IGFBP3) as one of the significantly up-regulated genes in the sublines in comparison with their parental cells. Consistently, meta-analysis of the public microarray datasets and IGFBP3 immunohistochemical analysis revealed increased both levels of IGFBP3 mRNA and protein in human OSCC tissues when compared to normal oral or adjacent nontumorous tissues. Interestingly, the up-regulated IGFBP3 mRNA expression was significantly associated with OSCC patients with lymph node metastasis. IGFBP3 knockdown in the sublines impaired and ectopic IGFBP3 expression in the parental cells promoted migration, transendothelial migration and lymph node metastasis of orthotopic transplantation. Additionally, ectopic expression of IGFBP3 with an IGF-binding defect sustained the IGFBP3-enhanced biological functions. Results indicated that IGFBP3 regulates metastasis-related functions of OSCC cells through an IGF-independent mechanism. Furthermore, exogenous IGFBP3 was sufficient to induce cell motility and extracellular signal-regulated kinase (ERK) activation. The silencing of integrin β1 was able to impair exogenous IGFBP3-mediated migration and ERK phosphorylation, suggesting a critical role of integrin β1 in IGFBP3-enchanced functions.

Quantitative analysis of insulin-like growth factor 2 receptor and insulin-like growth factor binding proteins to identify control mechanisms for insulin-like growth factor 1 receptor phosphorylation

Background

The insulin-like growth factor (IGF) system impacts cellular development by regulating proliferation, differentiation, and apoptosis, and is an attractive therapeutic target in cancer. The IGF system is complex, with two ligands (IGF1, IGF2), two receptors (IGF1R, IGF2R), and at least six high affinity IGF-binding proteins (IGFBPs) that regulate IGF ligand bioavailability. While the individual components of the IGF system are well studied, the question of how these different components integrate as a system to regulate cell behavior is less clear.

Results

To analyze the relative importance of different mechanisms that control IGF network activity, we developed a mass-action kinetic model incorporating cell surface binding, phosphorylation, and intracellular trafficking events. The model was calibrated and validated using experimental data collected from OVCAR5, an immortalized ovarian cancer cell line. We then performed model analysis to examine the ability of IGF2R or IGFBPs to counteract phosphorylation of IGF1R, a critical step for IGF network activation. This analysis suggested that IGF2R levels would need to be 320-fold greater than IGF1R in order to decrease pIGF1R by 25 %, while IGFBP levels would need to be 390-fold greater. Analysis of The Cancer Genome Atlas (TCGA) data set suggested that this level of overexpression is unlikely for IGF2R in ovarian, breast, and colon cancer. In contrast, IGFBPs can likely reach these levels, suggesting that IGFBPs are the more critical regulator of IGF1R network activity. Levels of phosphorylated IGF1R were insensitive to changes in parameters regulating the IGF2R arm of the network.

Conclusions

Using a mass-action kinetic model, we determined that IGF2R plays a minor role in regulating the activity of IGF1R under a variety of conditions and that due to their high expression levels, IGFBPs are the dominant mechanism to regulating IGF network activation.

Electronic supplementary material

The online version of this article (doi:10.1186/s12918-016-0263-6) contains supplementary material, which is available to authorized users.

Analysis of the quantitative balance between insulin-like growth factor (IGF)-1 ligand, receptor, and binding protein levels to predict cell sensitivity and therapeutic efficacy

Background

The insulin-like growth factor (IGF) system impacts cell proliferation and is highly activated in ovarian cancer. While an attractive therapeutic target, the IGF system is complex with two receptors (IGF1R, IGF2R), two ligands (IGF1, IGF2), and at least six high affinity IGF-binding proteins (IGFBPs) that regulate the bioavailability of IGF ligands. We hypothesized that a quantitative balance between these different network components regulated cell response.

Results

OVCAR5, an immortalized ovarian cancer cell line, were found to be sensitive to IGF1, with the dose of IGF1 (i.e., the total mass of IGF1 available) a more reliable predictor of cell response than ligand concentration. The applied dose of IGF1 was depleted by both cell-secreted IGFBPs and endocytic trafficking, with IGFBPs sequestering up to 90% of the available ligand. To explore how different variables (i.e., IGF1, IGFBPs, and IGF1R levels) impacted cell response, a mass-action steady-state model was developed. Examination of the model revealed that the level of IGF1-IGF1R complexes per cell was directly proportional to the extent of proliferation induced by IGF1. Model analysis suggested, and experimental results confirmed, that IGFBPs present during IGF1 treatment significantly decreased IGF1-mediated proliferation. We utilized this model to assess the efficacy of IGF1 and IGF1R antibodies against different network compositions and determined that IGF1R antibodies were more globally effective due to the receptor-limited state of the network.

Conclusions

Changes that affect IGF1R occupancy have predictable effects on IGF1-induced proliferation and our model captured these effects. Analysis of this model suggests that IGF1R antibodies will be more effective than IGF1 antibodies, although the difference was minimal in conditions with low levels of IGF1 and IGFBPs. Examining how different components of the IGF system influence cell response will be critical to improve our understanding of the IGF signaling network in ovarian cancer.

Circulating IGF system and treatment outcome in epithelial ovarian cancer

Aggressive epithelial ovarian cancers (EOCs) frequently progress and become fatal, even when cytoreduction surgery plus platinum-based chemotherapy are performed. Thus, the early detection of high-risk subgroups is important in order to provide opportunities for better treatment outcomes, using alternative therapeutic strategies. This study aimed to explore the expression of circulating IGF system components and their relationship with treatment outcome in EOC. We included 228 patients with a median follow-up time of 44 months at two tertiary centers. There were 68 cancer deaths and 108 cases of cancer progression in the cohort. Preoperative serum levels of total IGF1, IGF2, IGF-binding protein 2 (IGFBP2), and IGFBP3 were analyzed using an ELISA and were then converted into an IGF1:IGFBP3 molar ratio. The risks of mortality and progression were estimated using Cox regression models in univariate and multivariate analyses. Our results showed that high IGF1, IGF2, and IGFBP3 levels were significantly associated with an early cancer stage, non-serous histology, and optimal cytoreduction. High IGFBP2 levels were associated with an advanced stage and serous histology. Overall and progression-free survival durations were significantly better among patients with high IGF1 (P=0.003 and P=0.001), IGF2 (P=0.003 and P=0.02), or IGFBP3 levels (P=0.02 and P=0.008). In multivariate analysis, serum IGFBP2 levels were significantly associated with increased risk of mortality (hazard ratio=1.84, 95% CI: 1.07-3.18, P=0.03), indicating that IGFBP2 could be used as an early predictor of EOC-related mortality. The combination of elevated IGFBP2 and reduced IGF1 levels at diagnosis could further facilitate the identification of a patient subgroup with the worst prognosis.

Clinical significance of serum insulin-like growth factor-1 (IGF-1) and insulinlike growth factor binding protein-3 (IGFBP-3) in patients with epithelial ovarian cancer

Insulin-like growth factor-1 (IGF-1) and its primary binding protein IGFBP-3 play an important role in cellular proliferation, differentiation, and apoptosis in many tumors, including ovarian cancer. The objective of this study was to determine the clinical significance of the serum levels of IGF-1 and IGFBP-3 in epithelial ovarian cancer (EOC) patients. A total of 50 patients with a pathologically confirmed diagnosis of EOC were enrolled into this study. Serum IGF-1 and IGFBP-3 levels were determined by the solid-phase sandwich ELISA method. Twenty age- and sex-matched healthy controls were included in the analysis. Median age of patients was 56.5 years old (range 22 to 83 years). Majority of the patients had advanced disease (FIGO stage III-IV; 90%). No significant difference was observed in baseline serum IGF-1 and IGFBP-3 levels between EOC patients and healthy controls (p = 0.99 and p = 0.80, respectively). The young patients had higher serum IGF-1 and IGFBP-3 concentrations (p = 0.04 and p = 0.02, respectively). Patients with normal CA-125 levels had higher serum IGFBP-3 concentrations compared with those with higher CA-125 levels (p = 0.008). However, no other clinical variables including histology, tumor grade, stage of disease, and response to chemotherapy were found to be correlated with serum IGF assays (p > 0.05). A trend to significant relationship was found between the serum levels of IGF-1 and IGFBP-3 (r(s) = 0.212, p = 0.07). The patients with elevated serum IGF-1 levels had favorable progression-free and overall survivals than those with lower levels (p = 0.04 and p = 0.03, respectively). However, serum IGFBP-3 concentrations were found to have no prognostic role for both survivals (p = 0.12 and p = 0.26, respectively). In conclusion, elevated serum level of IGF-1 is associated with favorable progression-free and overall survivals in EOC patients.

Insulin-like growth factor binding protein-3 (IGFBP-3): Novel ligands mediate unexpected functions

In addition to its important role in the regulation of somatic growth by acting as the major circulating transport protein for the insulin-like growth factors (IGFs), IGF binding protein-3 (IGFBP-3) has a variety of intracellular ligands that point to its function within major signaling pathways. The discovery of its interaction with the retinoid X receptor has led to the elucidation of roles in regulating the function of several nuclear hormone receptors including retinoic acid receptor-α, Nur77 and vitamin D receptor. Its interaction with the nuclear hormone receptor peroxisome proliferator-activated receptor-γ is believed to be involved in regulating adipocyte differentiation, which is also modulated by IGFBP-3 through an interaction with TGFβ/Smad signaling. IGFBP-3 can induce apoptosis alone or in conjunction with other agents, and in different systems can activate caspases -8 and -9. At least two unrelated proteins (LRP1 and TMEM219) have been designated as receptors for IGFBP-3, the latter with a demonstrated role in inducing caspase-8-dependent apoptosis. In contrast, IGFBP-3 also has demonstrated roles in survival-related functions, including the repair of DNA double-strand breaks through interaction with the epidermal growth factor receptor and DNA-dependent protein kinase, and the induction of autophagy through interaction with GRP78. The ability of IGFBP-3 to modulate the balance between pro-apoptotic and pro-survival sphingolipids by regulating sphingosine kinase 1 and sphingomyelinases may be integral to its role at the crossroads between cell death and survival in response to a variety of stimuli. The pleiotropic nature of IGFBP-3 activity supports the idea that IGFBP-3 itself, or pathways with which it interacts, should be investigated as targets of therapy for a variety of diseases.

Targeting insulin and insulin-like growth factor pathways in epithelial ovarian cancer

Ovarian cancer is the most lethal of all gynecological malignancies, due in part to the diagnosis at an advanced stage caused by the lack of specific signs and symptoms and the absence of reliable tests for screening and early detection. Most patients will respond initially to treatment but about 70% of them will suffer a recurrence. Therefore, new therapeutic modalities are urgently needed to overcome chemoresistance observed in ovarian cancer patients. Evidence accumulates suggesting that the insulin/insulin growth factor (IGF) pathways could act as a good therapeutic target in several cancers, including ovarian cancer. In this paper, we will focus on the role of insulin/IGF in ovarian cancer tumorigenesis and treatment.

Correlation analysis of HOX, ErbB and IGFBP family gene expression in ovarian cancer

Utilizing microarray gene expression data in cancer research possesses the ability to identify deregulated cellular pathways involved in malignant development. This study investigated the relationships of three gene families, HOX, ErbB and IGFBP, with regard to the development of ovarian cancer. These families were of interest because of similar chromosomal locations and their deregulated expression in ovarian cancer. Higher level statistics were used to differentially analyze microarray data in 65 ovarian samples to assess correlation and relationships among the gene families of interest. Fifteen genes in the three families were found to be significantly deregulated. Thirty-eight significant correlations were found within and between the genes of interest. Our data indicates that the significantly modeled relationships between HOX, ErbB and IGFBP gene pairs could provide insight into the underlying biological mechanisms in ovarian cancer.

Diagnostic and prognostic role of the insulin growth factor pathway members insulin-like growth factor-II and insulin-like growth factor binding protein-3 in serous effusions

We recently reported on higher expression of the insulin-like growth factor pathway genes IGF-II and IGFBP3 in serous ovarian/peritoneal carcinoma compared to malignant peritoneal mesothelioma. The present study analyzed the diagnostic and clinical role of these proteins in serous effusions. Effusions (n = 327), including 294 carcinomas (205 ovarian, 48 breast, 17 cervical/endometrial, 12 lung, 12 gastrointestinal/genitourinary) and 33 malignant mesotheliomas, were immunostained for insulin-like growth factor-II and insulin-like growth factor binding protein-3. Surgical ovarian carcinoma (n = 124) and peritoneal mesothelioma (n = 18) specimens were additionally studied. Insulin-like growth factor binding protein-3 levels were measured in 148 effusion supernatants (114 ovarian carcinomas, 18 breast carcinomas, 16 mesotheliomas) using enzyme-linked immunosorbent assay. Insulin-like growth factor binding protein-3 promoter methylation was analyzed in 11 ovarian carcinoma effusions. Insulin-like growth factor binding protein-3 (P = .002) and insulin-like growth factor-II (P < .001) expression by immunohistochemistry was significantly higher in carcinomas compared to mesotheliomas, with diagnostic sensitivity of 77% and 70% and specificity of 55% and 70%, respectively. In surgical specimens, insulin-like growth factor binding protein-3 expression was higher in ovarian carcinomas compared to peritoneal mesotheliomas (P = .007), whereas insulin-like growth factor-II expression was comparable (P = .505). Insulin-like growth factor binding protein-3 levels by enzyme-linked immunosorbent assay were comparable in the 3 analyzed cancer types. Insulin-like growth factor binding protein-3 promoter methylation was found in 6 of 11 effusions. High insulin-like growth factor binding protein-3 expression in prechemotherapy and high insulin-like growth factor-II expression in postchemotherapy ovarian carcinoma effusions correlated with poor overall survival (P = .031 and P = .024, respectively). Insulin-like growth factor-II expression in postchemotherapy effusions was an independent prognostic factor in Cox multivariate analysis (P = .04). In conclusion, insulin-like growth factor-II and insulin-like growth factor binding protein-3 are more frequently expressed in metastatic carcinomas compared to mesothelioma in effusions but are less specific than currently used markers. Insulin-like growth factor-II and insulin-like growth factor binding protein-3 may be novel prognostic markers in metastatic ovarian carcinoma.

Serum insulin-like growth factor (IGF)-I, IGF binding protein (IGFBP)-3, leptin concentrations and insulin resistance in benign and malignant epithelial ovarian tumors in postmenopausal women

AIMS

The aims of the present study were to determine the serum concentrations of insulin-like growth factor-I (IGF-I), insulin-like growth factor binding protein-3 (IGFBP-3) and leptin and insulin resistance in benign and malignant epithelial ovarian tumors, and to discuss the use of these markers in benign-malignant tumor differentiation.

METHODS

Forty-seven postmenopausal women with ovarian tumor and 31 age-matched, postmenopausal, healthy controls were included in this study. Insulin resistance index by homeostasis model assessment (HOMA score) and fasting blood glucose (FBG), serum IGF-I, IGFBP-3, leptin and CA-125 concentrations were determined in all patients preoperatively. The results were evaluated according to postoperative histopathology results.

RESULTS

According to postoperative histopathology results, the patients were divided into malignant (n = 23), benign (n = 24) and control (n = 31) groups. There were no differences among the groups in relation to age, body mass index, FBG and HOMA score (p > 0.05). Serum concentrations of CA-125 were elevated in the malignant group compared with the benign ovarian tumor and control groups (p < 0.05). In contrast, serum IGF-I concentrations were significantly decreased in patients with malignant and benign ovarian tumors compared with controls (p < 0.05). Serum IGFBP-3 concentrations were also found to be lower in women with malignant ovarian tumors than in women with benign tumors (p < 0.05). Serum leptin did not differ among patients with malignant-benign tumors and controls (p > 0.05).

CONCLUSION

Serum leptin and HOMA score have not been found to be valid indicators in ovarian tumors. However, the present data suggest that low concentrations of IGF-I and IGFBP-3 could be a reliable marker to differentiate benign from malignant ovarian tumors. Further experimental studies are warranted to understand the impact of the IGF-I system in ovarian carcinogenesis.

EZH2 polycomb transcriptional repressor expression correlates with methylation of the APAF-1 gene in superficial transitional cell carcinoma of the bladder

The EZH2 gene controls methylation of various EZH2 target promoters. The APAF-1, DAPK-1 und IGFBP-3 genes are frequently methylated in bladder cancer, and methylation of these genes is found in more aggressive tumor types. The aim of our study was to investigate a potential link between EZH2 mRNA expression and the extent of APAF-1, DAPK-1 and IGFBP-3 methylation in urothelial transitional cell carcinoma (TCC) and to correlate the data with histopathological parameters and follow-up data. EZH2 mRNA expression was measured by real-time reverse transcription polymerase chain reaction, and the methylation analysis was performed using methylation-specific real-time polymerase chain reaction. Tissue specimens were obtained from 35 patients with TCC. EZH2 mRNA expression was detected in all tumor specimens investigated. The EZH2 expression levels correlated well with the differentiation grade of the tumor specimens (p = 0.03), and the APAF-1 methylation correlated with tumor stage (p = 0.0001) and grade (p = 0.004). Matched pair analysis demonstrated a statistically significant correlation between elevated EZH2 mRNA expression and higher methylation levels of APAF-1 in superficial (p = 0.024) and well- differentiated (p = 0.04) TCC. In patients with recurrent TCC, APAF-1 and IGFBP-3 methylation levels were significantly higher (p = 0.03 and p = 0.01, respectively), which was not observed when EZH2 mRNA expression or DAPK-1 methylation levels were related to the clinical outcome. In conclusion, our data show that EZH2 expression and APAF-1 methylation are related to tumor progression and invasiveness. Moreover, these data present first evidence that APAF-1 methylation is related to transcriptional activity of EZH2 expression in early-stage tumor disease of the bladder.

Insulin-like growth factor binding proteins IGFBP3, IGFBP4, and IGFBP5 predict endocrine responsiveness in patients with ovarian cancer

PURPOSE

This study sought to explore the predictive value of the insulin-like growth factor (IGF) binding proteins (IGFBP) as markers of response in ovarian cancer patients treated with the aromatase inhibitor letrozole.

EXPERIMENTAL DESIGN

IGFBP mRNA expression in cell lines was measured by quantitative reverse transcription-PCR and IGFBP protein expression measured in sections from primary tumors of patients treated with letrozole by semiquantitative immunohistochemistry.

RESULTS

Quantitative reverse transcription-PCR analysis showed that IGFBP3 and IGFBP5 were down-regulated and IGFBP4 was up-regulated by 17beta-estradiol (E(2)) in an estrogen receptor (ER)-positive ovarian cancer cell line. Expressions of IGFBP1, IGFBP2, and IGFBP6 were unaffected by E(2). The E(2) modulation of these genes was reversed by tamoxifen. Using ERalpha-specific (propyl pyrazole triol) and ERbeta-specific (diarylpropionitrile) agonists, the gene expression modulations produced by E(2) could be replicated by propyl pyrazole triol but not by diarylpropionitrile. For ovarian cancer patients being treated with letrozole, we tested the predictive value of the IGFBPs in paraffin-fixed sections from their primary tumors by semiquantitative immunohistochemistry. Using serum CA125 as an indicator of progression/response, significant differences in expression levels of IGFBPs were observed between tumors from CA125 responding/stable patients compared with tumors from progressing patients. Mean immunoscores for IGFBP3 and IGFBP5 were significantly lower, and mean expression of IGFBP4 was significantly higher in tumors from patients demonstrating CA125 response or stabilization compared with CA125 progression.

CONCLUSION

These results indicate that expression levels of certain IGFBP family members in ovarian cancers are estrogen regulated and can, thus, help identify patients who could benefit from endocrine therapy.

Regularly methylated novel pro-apoptotic genes associated with recurrence in transitional cell carcinoma of the bladder

Epigenetic silencing of tumor suppressor genes by promoter hypermethylation has been shown for a variety of genes in bladder cancer. Various p53 target genes have been investigated, but only few demonstrated promoter hypermethylation when semiquantitative detection methods were applied. To address to the question whether promoter methylation of novel p53 effector genes is a common event in transitional cell carcinoma of the bladder, we selected the p53 target genes apoptotic protein-activating factor (APAF-1), Caspase 8 (CASP-8), death-associated protein kinase, (DAPK-1) and insulin-like growth-factor-binding protein-3 (IGFBP-3), performing quantitative methylation-specific real-time PCR. The individual level of methylation (normalized index of methylation) was correlated with clinicopathological features as well as the biological behavior of the superficial and muscleinvasive tumors. Tissue was obtained from 110 tumor patients and 20 patients without urological malignancy. The median follow-up of the tumor patients was 52 months. Hypermethylation of the promoter region in tumor specimens was common for APAF-1 (100%), DAPK-1 (74%) and IGFBP-3 (66%), but not for CASP-8 (3.6%). It was seen less frequently and with undetectable or low methylation levels in the normal urothelium group. The APAF-1 methylation levels significantly correlated with tumor stage and tumor grade. The APAF-1 and IGFBP-3 methylation levels were able to separate tumors with higher recurrence risk from low-risk tumors in nonmuscleinvasive and muscleinvasive tumors. In multivariate analysis, APAF-1 and IGFBP-3 methylation levels were independent prognostic markers for recurrence in superficial bladder tumors. This study provides new insights into the role of promoter methylation of selected p53 target genes. The extent of promoter methylation of specific genes offers additional prognostical information and is associated with the outcome in patients with nonmuscleinvasive and muscleinvasive bladder cancer.

Insulin-like growth factor-binding protein 2 and 5 are differentially regulated in ovarian cancer of different histologic types

The family of insulin-like growth factor-binding proteins (IGFBPs) comprises six members, which bind and regulate the functions of insulin-like growth factors. Overexpression of IGFBP2 and IGFBP5 contributes to the invasiveness and progression of several human cancers, but their role and clinical significance in ovarian cancer has not been investigated in detail. We examined IGFBP2 and IGFBP5 expression levels using two tissue microarrays, one containing six normal surface epithelium, six benign serous cysts, 10 serous borderline tumors, eight low-grade, and 20 high-grade serous carcinomas. The other comprising 441 ovarian cancers of different histologic types linked to a clinicopathologic database. Each tumor was sampled in duplicate with a 1.0-mm punch core needle. Immunohistochemical staining was performed using antibodies against IGFBP2 or IGFBP5. The staining intensity was scored semiquantitatively as negative (0), weak (1-10%), moderate (10-50%), or strong (50-100%) using computerized image analysis. Statistical analyses used Fisher's exact test and Kaplan-Meier method. IGFBP2 and IGFBP5 were overexpressed in high-grade serous carcinomas compared to normal surface epithelium, benign serous cysts, serous borderline tumors, or low-grade serous carcinoma. They were differentially expressed in different types of ovarian carcinomas, being more often expressed at high levels in high-grade serous carcinoma, malignant mixed mullerian tumors and undifferentiated carcinoma, and more often expressed at low levels or not at all in clear cell and mucinous carcinomas. We concluded that IGFBP2 and IGFBP5 might play a role in the development of high-grade ovarian serous carcinoma, but not in mucinous or clear cell ovarian carcinomas.

Methylation of the insulin-like growth factor binding protein-3 gene and prognosis of epithelial ovarian cancer

Insulin-like growth factor binding protein-3 (IGFBP-3) is a member of the IGFBP family, which regulates the mitogenic and antiapoptotic effects of insulin-like growth factors. Hypermethylation of the IGFBP-3 promoter has been found to suppress its expression. To evaluate the role of IGFBP-3 in ovarian cancer progression, we examined the survival of 235 consecutively selected epithelial ovarian cancer patients in association with IGFBP-3 promoter methylation and IGFBP-3 expression in tumor tissue. IGFBP-3 promoter methylation was analyzed using methylation-specific polymerase chain reaction. Cytosol protein was extracted and measured using a bicinchoninic acid assay; IGFBP-3 was measured by enzyme linked immunosorbent assay. Promoter methylation of the IGFBP-3 gene was detected in 44% (104/235) of patients. IGFBP-3 promoter methylation was associated with disease progression and death after adjusting for clinical and pathologic variables. The association was more evident in patients with early-stage disease: RR = 2.87 (95% CI: 0.78-10.63) for disease progression and RR = 3.94 (95% CI: 0.91-15.78) for death. Tissue levels of IGFBP-3 did not differ by methylation status but were inversely associated with disease stage and residual tumor size. These results suggest that IGFBP-3 promoter methylation may be a useful prognostic marker for disease progression and death in early-stage ovarian cancer.

IGFBP-3 Is a Direct Target of Transcriptional Regulation by ΔNp63α in Squamous Epithelium

DeltaNp63alpha is a nuclear transcription factor that maintains epithelial progenitor cell populations, is overexpressed in several epithelial cancers, and can negatively regulate apoptosis. However, the mechanisms by which DeltaNp63alpha promotes cell survival are unclear. DeltaNp63alpha has been reported to act as a transcriptional repressor, but specific target genes directly repressed by DeltaNp63alpha remain unidentified. Here, we present evidence that DeltaNp63alpha functions to negatively regulate the proapoptotic protein IGFBP-3. Disruption of p63 expression in squamous epithelial cells increases IGFBP-3 expression, whereas ectopic expression of DeltaNp63alpha down-regulates IGFBP-3. DeltaNp63alpha binds to sites in the IGFBP-3 gene in vivo and can modulate transcription through these sites. Furthermore, DeltaNp63alpha and IGFBP-3 expression patterns are inversely correlated in normal squamous epithelium and squamous cell carcinomas. These data suggest that IGFBP-3 is a target of transcriptional repression by DeltaNp63alpha and that this repression represents a mechanism by which tumors that overexpress p63 may be protected from apoptosis.

Physical activity and the risk of ovarian cancer: A case-control study in Canada

We evaluated the impact of recreational and occupational physical activity on ovarian cancer risk using data from a population-based case-control study of 442 cases with histologically confirmed incident ovarian cancer and 2,135 controls aged 20-76 years, conducted in 1994-1997 in Canada. Frequency and intensity of physical activity were collected through self-administered questionnaires. Compared to women in the lowest tertiles of moderate, vigorous and total recreational activity, those in the highest tertiles had multivariable-adjusted odds ratios (and 95% confidence intervals) of 0.67 (0.50-0.88), 0.93 (0.70-1.24) and 0.73 (0.58-0.98), respectively. There were statistically significant trends of decreasing risk with increasing levels of moderate and total recreational activity, with similar patterns for premenopausal and postmenopausal women. A significant reduction in risk associated with higher level of moderate recreational activity was observed for serous, endometrioid and other but not mucinous types of tumors. The analyses in one province with the largest number of cases and controls indicated that occupational activity was associated with reduced ovarian cancer risk by lifetime activity and by various life periods (early 20s, early 30s, early 50s and 2 years before interview). Our study suggests that occupational and regular moderate recreational physical activity reduce ovarian cancer risk.

Association between Components of the Insulin-Like Growth Factor System and Epithelial Ovarian Cancer Risk

BACKGROUND

Components of the insulin-like growth factor (IGF) system have been associated with several cancers, but very few studies are available for ovarian cancer.

METHODS

A case-control study conducted between 1999 and 2003 in Italy, including a total of 59 women with incident, histologically confirmed ovarian cancer and 108 controls admitted to the same hospital network as cases, for acute non-neoplastic diseases. All subjects were interviewed using a validated questionnaire.

RESULTS

After adjustment for potential confounders, the multivariate odds ratios for the highest versus the lowest tertile of various IGF components were 0.6 (95% confidence interval, CI: 0.2-1.4) for free IGF-I, 0.4 (CI: 0.1-1.5) for total IGF-I, 2.6 (CI: 0.9-6.9) for IGF-binding protein (IGFBP)-1, and 0.2 (CI: 0.0-0.6) for IGFBP-3.

CONCLUSIONS

This study suggests a protective role of IGFBP-3 and a positive association of IGFBP-1 with ovarian cancer. The complex role of the IGF system in ovarian carcinogenesis deserves further clarification.

Expression of insulin-like growth factor binding protein-3 before and after neoadjuvant hormonal therapy in human prostate cancer tissues: correlation with histopathologic effects and biochemical recurrence

OBJECTIVES

To determine the effects of neoadjuvant hormonal therapy (NHT) on insulin-like growth factor binding protein (IGFBP)-3 expression and whether IGFBP-3 expression influences the pathologic effect of NHT and biochemical recurrence after radical prostatectomy in patients with prostate cancer. IGFBP-3 has pro-apoptotic activity, and its expression correlates negatively with prostate cancer cell growth. Castration induces IGFBP-3 expression and apoptosis in the rat prostate.

METHODS

We used tissue specimens from 42 patients who underwent NHT and radical prostatectomy. The pre-NHT and post-NHT specimens were examined for expression of IGFBP-3 using an immunohistochemical technique and for apoptosis using the terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling method. The histopathologic effect was evaluated by the standardized rules for estimating the response of prostate cancer to NHT, determined by the percentage of remaining viable cancer cells, as advocated by the General Rule for Clinical and Pathological Study on Prostate Cancer published by the Japanese Urological Association.

RESULTS

NHT resulted in a statistically significant increase in IGFBP-3 expression compared with baseline (P = 0.01). Such an increase in expression correlated significantly with the induction of apoptotic cells (r = 0.40 and P = 0.01). The post-NHT/pre-NHT IGFBP-3 ratio was significantly greater in the NHT-effective group than in the NHT-noneffective group (P = 0.02). Patients with high IGFBP-3 expression in the post-NHT specimens had a good prognosis (P = 0.03, log-rank test).

CONCLUSIONS

Induction of IGFBP-3 by NHT was associated with apoptosis and a histopathologic effect. IGFBP-3 expression in post-NHT specimens is a potentially useful predictor of biochemical recurrence in patients with prostate cancer.

Elevated serum insulin-like growth factor binding protein-2 as a prognostic marker in patients with ovarian cancer

PURPOSE

The purpose of this research was to examine the diagnostic and prognostic significance of elevated serum insulin-like growth factor binding protein (IGFBP)-2 levels in women with ovarian cancer from diagnosis through treatment to relapse or remission.

EXPERIMENTAL DESIGN

Serum collected pre- and postoperatively in women newly diagnosed with ovarian cancer, during adjuvant chemotherapy cycles, at 6 months follow-up and at relapse was analyzed for IGFBP-2. Control serum was from women undergoing pelvic or abdominal surgery for benign ovarian disease or nonovarian pathology.

RESULTS

IGFBP-2 at diagnosis was significantly elevated (P < 0.0001) in women with ovarian cancer (887 +/- 62 ng/ml) compared with benign controls (337 +/- 25 ng/ml), and women undergoing nonovarian surgery (439 +/- 49 ng/ml) and correlated positively with tumor stage and cellular differentiation but not with CA125. Unexpectedly, IGFBP-2 levels increased additionally 1-week postoperatively in ovarian cancer patients (1581 +/- 90 ng/ml; P = 0.0027) as well as controls (977 +/- 95 ng/ml; P < 0.0001) and was higher in women who had suboptimal debulking compared with optimal debulking of their tumor. IGFBP-2 levels returned to normal in women without evidence of progressive disease, but remained significantly elevated in women who later relapsed. Patients with IGFBP-2 levels in the highest tertile at diagnosis had a significantly shorter progression-free interval and overall survival.

CONCLUSION

In ovarian cancer IGFBP-2 is elevated at diagnosis, and corresponds to stage and histology with patients in the highest tertile of IGFBP-2 more likely to relapse and have a poorer outlook. Identification of these patients at diagnosis may allow more individualized, aggressive adjuvant treatment and follow-up, and IGFBP-2 may therefore be an important additional prognostic marker in this disease.

Correlation of preoperative levels of IGF-I and IGFBP-3 with pathologic parameters and clinical outcome in patients with bladder cancer

OBJECTIVES

To test the hypothesis that plasma insulin growth factor (IGF)-I or IGF binding protein (BP)-3 levels would differ between patients with bladder cancer and healthy controls and whether preoperative plasma IGF-I or IGFBP-3 could predict the pathologic characteristics and clinical outcome of patients with bladder cancer undergoing radical cystectomy. The IGFs are mitogens that have been shown to play a significant role in regulating proliferation and differentiation of bladder cancer cells.

METHODS

The study group consisted of 51 patients who underwent radical cystectomy (median follow-up 45.7 months). The preoperative plasma levels of IGF-I and IGFBP-3 were measured using DSL-enzyme-linked immunosorbent assays. The IGF-I and IGFBP-3 levels were also measured in 44 healthy men.

RESULTS

The plasma IGF-I and IGFBP-3 levels in patients with bladder cancer were not significantly different from those in healthy subjects (P >or=0.339). In a preoperative model that included clinical grade, clinical stage, and either IGF-I or IGFBP-3, none of the parameters was associated with either metastases to lymph nodes or clinical outcome. However, in an alternative model that included both IGF-I and IGFBP-3 in addition to clinical stage and grade, only a lower preoperative plasma IGFBP-3 level was associated with metastases to regional lymph nodes, bladder cancer progression, and survival (P = 0.047, 0.050, and 0.040, respectively).

CONCLUSIONS

We found no association between preoperative plasma IGF-I and bladder cancer characteristics or outcome, limiting the clinical utility of IGF-I. In contrast, a lower preoperative plasma level of IGFBP-3 was associated with lymph node metastasis and poorer clinical outcome after radical cystectomy when adjusted for IGF-I level.

Intratumoral T cells, recurrence, and survival in epithelial ovarian cancer

BACKGROUND

Although tumor-infiltrating T cells have been documented in ovarian carcinoma, a clear association with clinical outcome has not been established.

METHODS

We performed immunohistochemical analysis of 186 frozen specimens from advanced-stage ovarian carcinomas to assess the distribution of tumor-infiltrating T cells and conducted outcome analyses. Molecular analyses were performed in some tumors by real-time polymerase chain reaction.

RESULTS

CD3+ tumor-infiltrating T cells were detected within tumor-cell islets (intratumoral T cells) in 102 of the 186 tumors (54.8 percent); they were undetectable in 72 tumors (38.7 percent); the remaining 12 tumors (6.5 percent) could not be evaluated. There were significant differences in the distributions of progression-free survival and overall survival according to the presence or absence of intratumoral T cells (P<0.001 for both comparisons). The five-year overall survival rate was 38.0 percent among patients whose tumors contained T cells and 4.5 percent among patients whose tumors contained no T cells in islets. Significant differences in the distributions of progression-free survival and overall survival according to the presence or absence of intratumoral T cells (P<0.001 for both comparisons) were also seen among 74 patients with a complete clinical response after debulking and platinum-based chemotherapy: the five-year overall survival rate was 73.9 percent among patients whose tumors contained T cells and 11.9 percent among patients whose tumors contained no T cells in islets. The presence of intratumoral T cells independently correlated with delayed recurrence or delayed death in multivariate analysis and was associated with increased expression of interferon-gamma, interleukin-2, and lymphocyte-attracting chemokines within the tumor. The absence of intratumoral T cells was associated with increased levels of vascular endothelial growth factor.

CONCLUSIONS

The presence of intratumoral T cells correlates with improved clinical outcome in advanced ovarian carcinoma.

Circulating levels of insulin-like growth factor-I and risk of ovarian cancer

Insulin-like growth factor (IGF)-I, a mitogenic and anti-apoptotic peptide, has been implicated in the development of several cancers. We hypothesized that high circulating IGF-I concentrations may be associated with an increased risk of ovarian cancer. A case-control study was nested within 3 prospective cohorts in New York (USA), Umeå (Sweden) and Milan (Italy). One hundred thirty-two women with primary invasive epithelial ovarian cancer diagnosed at least 1 year after blood donation were case subjects. For each case, 2 control subjects were selected, matching the case subject on cohort, menopausal status, age and date of recruitment (n = 263). Only women who did not use exogenous hormones at blood donation were included in the study. There was no association between IGF-I concentrations and ovarian cancer risk in the study group as a whole. In analyses restricted to subjects who had developed ovarian cancer at a young age (<55), circulating IGF-I was directly and strongly associated with ovarian cancer risk (OR = 4.97; 95% CI = 1.22-20.2 for the top vs. the bottom IGF-I tertile after adjustment for parity, BMI categories and smoking). There was no significant association of IGF binding protein-3 with ovarian cancer risk. We found a strong direct relationship between circulating IGF-I levels and risk of developing ovarian cancer before age 55. Additional, larger studies of this association are needed to provide more precise estimates of effect.