The angiogenic "vascular endothelial growth factor/flk-1(KDR) receptor" pathway in patients with endometrial carcinoma: prognostic and therapeutic implications

Global expression analysis of endometrial cancer cells in response to progesterone identifies new therapeutic targets

Progesterone prevents development of endometrial cancers through its receptor (PR) although the molecular mechanisms have yet to be fully characterized. In this study, we performed a global analysis of gene regulation by progesterone using human endometrial cancer cells that expressed PR endogenously or exogenously. We found progesterone strongly inhibits multiple components of the platelet derived growth factor receptor (PDGFR), Janus kinase (JAK), signal transducer and activator of transcription (STAT) pathway through PR. The PDGFR/JAK/STAT pathway signals to control numerous downstream targets including AP-1 transcription factors Fos and Jun. Treatment with inhibitors of the PDGFR/JAK/STAT pathway significantly blocked proliferation in multiple novel patient-derived organoid models of endometrial cancer, and activation of this pathway was found to be a poor prognostic signal for the survival of patients with endometrial cancer from The Cancer Genome Atlas. Our study identifies this pathway as central to the growth-limiting effects of progesterone in endometrial cancer and suggests that inhibitors of PDGFR/JAK/STAT should be considered for future therapeutic interventions.

Diagnostic and Therapeutic Values of Angiogenic Factors in Endometrial Cancer

Endometrial cancer (EC) is the most frequent gynecological malignancy in developed countries and requires a relatively invasive diagnostic evaluation and operative therapy as the primary therapeutic approach. Angiogenesis is one of the main processes needed for cancer growth and spread. The production of angiogenic factors (AFs) appears early in the process of carcinogenesis. The detection of AFs in plasma and tissue and a better understanding of the angiogenic properties of EC may contribute not only to earlier but also more specific diagnosis and consequently tailored and individual therapeutic approaches. AFs and their receptors also have high potential as binding sites for targeted cancer therapy. In this review, we discuss angiogenesis in EC and the characteristics of the AFs that most contribute to angiogenesis in EC. We also highlight therapeutic strategies that target angiogenesis as potential EC therapy.

Obesity and altered angiogenic-related gene expression in endometrial cancer

OBJECTIVES

Evaluate association between obesity and angiogenic-related gene expression in endometrial cancer (EC). Evaluate interaction between diet and metformin on angiogenic-related gene expression.

METHODS

We evaluated the association between 168 human angiogenic-related genes and body mass index (BMI) in the TCGA Uterine Corpus Endometrial Carcinoma cohort (endometrioid endometrial cancer (EEC) cohort n = 290, and copy number high cohort n = 55), an independent validation cohort from Gynecologic Cancer Center of Excellence (GYN-COE) (n = 62) and corresponding 185 homologous mouse genes in an LKB1fl/flp53fl/fl mouse model of EC (n = 20). Mice received 60% of calories from fat in a high-fat diet (HFD), mimicking diet-induced obesity, versus 10% of calories from fat in a low-fat diet (LFD). After tumor growth, HFD (n = 5) and LFD (n = 5) mice were treated with metformin (200 mg/kg/day) or control. Whole transcriptome analysis of mouse tumors was performed using RNA-Seq.

RESULTS

At a false-discovery rate of 10%, twenty-one angiogenic-related genes were differentially expressed with respect to BMI when adjusting for grade in the TCGA EEC cohort. Evaluation of these genes in the mouse model control group revealed association between increased Edil3 expression in HFD versus LFD mice (2.5-fold change (FC); unadjusted p = 0.03). An interaction was observed for expression of Edil3 between diet and metformin treatment (unadjusted p = 0.009). Association between BMI and increased expression of EDIL3 was validated in one of four EDIL3 probesets in the GYN-COE cohort (p = 0.0011, adjusted p = 0.0342).

CONCLUSIONS

Obesity may promote tumor progression via differential modulation of angiogenic pathways in EEC. Our exploratory findings demonstrated that EDIL3 may be a candidate gene of interest.

Alleviation of Collagen-Induced Arthritis by Crotonoside through Modulation of Dendritic Cell Differentiation and Activation

Crotonoside, a guanosine analog originally isolated from Croton tiglium, is reported to be a potent tyrosine kinase inhibitor with immunosuppressive effects on immune cells. Due to its potential immunotherapeutic effects, we aimed to evaluate the anti-arthritic activity of crotonoside and explore its immunomodulatory properties in alleviating the severity of arthritic symptoms. To this end, we implemented the treatment of crotonoside on collagen-induced arthritic (CIA) DBA/1 mice and investigated its underlying mechanisms towards pathogenic dendritic cells (DCs). Our results suggest that crotonoside treatment remarkably improved clinical arthritic symptoms in this CIA mouse model as indicated by decreased pro-inflammatory cytokine production in the serum and suppressed expression of co-stimulatory molecules, CD40, CD80, and MHC class II, on CD11c⁺ DCs from the CIA mouse spleens. Additionally, crotonoside treatment significantly reduced the infiltration of CD11c⁺ DCs into the synovial tissues. Our in vitro study further demonstrated that bone marrow-derived DCs (BMDCs) exhibited lower yield in numbers and expressed lower levels of CD40, CD80, and MHC-II when incubated with crotonoside. Furthermore, LPS-stimulated mature DCs exhibited limited capability to prime antigen-specific CD4⁺ and T-cell proliferation, cytokine secretions, and co-stimulatory molecule expressions when treated with crotonoside. Our pioneer study highlights the immunotherapeutic role of crotonoside in the alleviation of the CIA via modulation of pathogenic DCs, thus creating possible applications of crotonoside as an immunosuppressive agent that could be utilized and further explored in treating autoimmune disorders in the future.

Post-transcriptional regulation of miRNA-15a and miRNA-15b on VEGFR gene and deer antler cell proliferation

Background

Deer antler is the only regenerative organ in mammals, the regeneration of antler is not only the regeneration of bone tissue, but also accompanied by the regeneration of nerves, blood vessels and so on. The purpose of the current study was to explore the effect of miRNA-15a and miRNA-15b on the regulation of sika deer vascular endothelial growth factor receptor (VEGFR) during rapid antler growth.

Materials and methods

The VEGFR 3′-UTR was analyzed by bioinformatics software to identify the highly matched miRNAs. After transfected with miRNA mimics, the expression of selected miRNAs were measured by RT-qPCR and the relative expression level of VEGFR protein was detected by Western Blot. Dual-luciferase activity assay was used to determine the target relationship between VEGFR and miRNAs. The cartilage cell proliferation and telomerase activity were measured by MTT kit and TRAP assay, respectively.

Results

The VEGFR 3′-UTR contains a binding site for miRNA-15a and miRNA-15b. Over-expression of miRNA-15a and miRNA-15b, which significantly reduced the expression level of VEGFR protein, inhibited the proliferation of cartilage cells, and decreased the telomerase activity of cartilage cells in vitro.

Conclusion

miRNA-15a and miRNA-15b represent novel regulatory factors of VEGFR expression in deer antler.

The significance of markers in the diagnosis of endometrial cancer

Endometrial cancer is one of the most common cancers experienced by women throughout the world. It is also the most common malignancy within the female reproductive system, representing 37.7% of all disorders. The incidence increases with age, and is diagnosed most frequently in women between 45 and 65 years old. In the last few years, numerous studies have been performed to identify tumour biomarkers. Biomarkers include not only protein routinely used as tumour markers but also genes and chromosomes. The limiting factor in the use of markers in the diagnosis of endometrial cancer is their lack of specificity. However, specific markers for endometrial cancer are the subject of much research attention. Although moderately elevated levels of markers are present in a number of inflammatory or non-malignant diseases, significantly increased levels of markers indicate the development of cancer. Recently, research has been focused on the identification of molecular changes leading to different histological subtypes of endometrial cancer. In this paper the authors reviewed several currently investigated markers. Progress in these investigations is very important in the diagnostics and treatment of endometrial cancer. In particular, the identification of novel mutations and molecular profiles should enhance our ability to personalise adjuvant treatment with genome-guided targeted therapy.

Targeting angiogenesis in endometrial cancer - new agents for tailored treatments

INTRODUCTION

Endometrial carcinoma represents the most frequent gynecologic tumor in developed countries. The majority of women presents with low-grade tumors but a significant subset of women experience recurrence and do not survive their disease. Patients with stage III/ IV or recurrent endometrial cancer have a poor prognosis. Identification of active and tolerable new targeted agents versus specific molecular targets is a priority objective. Angiogenesis is a complex process that plays a crucial role in the development of many types of cancer and in particular endometrial cancer.

AREAS COVERED

In this review, the authors highlight the main angiogenetic molecular pathways and the anti-angiogenic agents in Phase II clinical trials for endometrial cancer treatment. The authors focus on reports from recent years on angiogenesis inhibitors used in endometrial cancer, including anti- vascular endothelial growth factor (VEGF) monoclonal antibodies (bevacizumab and aflibercept), mammalian target of rapamycin inhibitors (mTORi) (everolimus, temsirolimus and ridaforolimus), PI3 K inhibitors (BKM120), tyrosine kinase inhibitors (brivanib, sunitinib, dovitinib and nintedanib) and thalidomide.

EXPERT OPINION

These anti-angiogenic drugs, while used either alone or in combination with chemotherapy, have presented mixed results in treating endometrial cancer patients. Challenges for the future include the identification of new pathways, early identification and overcoming resistance and the use of these molecules in combination with old and new chemotherapeutic and targeted agents.

Phase II evaluation of dalantercept, a soluble recombinant activin receptor-like kinase 1 (ALK1) receptor fusion protein, for the treatment of recurrent or persistent endometrial cancer: an NRG Oncology/Gynecologic Oncology Group Study 0229N

OBJECTIVE

This two-stage phase II study assessed activity of single agent dalantercept in patients with recurrent/persistent endometrial carcinoma (EMC).

METHODS

Eligible patients had persistent/recurrent EMC after 1-2 prior cytotoxic regimens, measurable disease (RECIST 1.1), and GOG performance≤2. Dalantercept 1.2mg/kg subcutaneous was administered once every 3weeks until disease progression (PD)/development of prohibitory toxicity. Primary objectives were to estimate the proportion of patients with persistent/recurrent EMC, who survive progression-free without receiving non-protocol therapy (TPFS) for at least 6months and to estimate the proportion having objective tumor response.

RESULTS

All 28 enrolled patients were eligible and evaluable. Median age: 62years. Most common histologies: 32% Grade 1/2 endometrioid and 54% serous tumors. Prior treatment: 1 or 2 regimens in 82% and 18% of patients, respectively. Eighteen patients received prior radiation therapy. Patients received 1-12 cycles of dalantercept, and 46% of patients received ≤2cycles. The most common adverse events (AE) were fatigue, anemia, constipation and peripheral edema. Grade 3/4 AEs occurred in 39% and 4% of patients. One grade 5 gastric hemorrhage in a patient with a history of radiation fibrosis/small bowel obstruction was deemed possibly dalantercept-related. All patients are off study: 86% for PD. No ORs were observed; 57% had stable disease and 11% had TPFS>6 mos. Median progression-free and overall survival: 2.1months (90% CI: 1.4-3.2) and 14.5months (90% CI: 7.0-17.5), respectively.

CONCLUSIONS

Dalantercept has insufficient single agent activity in recurrent EMC to warrant further investigation at this dose level and schedule.

The role of angiogenic factors in endometrial cancer

Endometrial cancer is the most common malignancy within the female reproductive system (37.7%). The incidence increases with age. Frequently this type of cancer is diagnosed in peri- and post-menopausal women. 60-70% of cancers occur in women over 60 years of age, and less than 5% in women below 40 years of age.

Angiogenesis is a process of formation of new microvessels from existing capillaries. There are four different mechanisms of new vessel growth: sprouting, intussusception, vessel elongation and incorporation of endothelial progenitor cells into new microvessels. Angiogenesis plays important roles in growth of endometrial cancers. This process is controlled by many angiogenic factors, for example vascular endothelial growth factor (VEGF). VEGF is the most powerful and most specific endothelial cell growth factor. It plays a crucial role in the initiation of physiological and pathological angiogenesis, lymphangiogenesis, and vasculogenesis. The VEGF family consists of VEGF-A, VEGF-B, VEGF-C, VEGF-D, VEGF-E, VEGF-F and PLGF (placental growth factor). The effects of VEGF are mediated through binding to the two specific and homologous receptors VEGFR-1 (FLT-1) and VEGFR-2 (KDR). Placental growth factor (PLGF) belongs to the VEGF family and it is also a very important growth factor. So far four isoforms of PLGF have been identified: PLGF-1 (PLGF131), PLGF-2 (PLGF152), PLGF-3 (PLGF203) and PLGF-4 (PLGF224).

Correlation between expression of biological markers and [F]fluorodeoxyglucose uptake in endometrial cancer

PURPOSE

Positron emission tomography/computer tomography (PET/CT) utilizing [(18)F]fluorodeoxyglucose ((18)F-FDG) has been recommended for the diagnosis, staging, therapy monitoring, prediction of prognosis, and detection of recurrence in endometrial cancer. We aimed to define the correlations of biological markers with (18)F-FDG uptake in endometrial cancer.

METHODS

29 patients (55 ± 8.93 years) with endometrial cancer were included in this study. All patients underwent hysterectomy and bilateral salpingo-oophorectomy with or without para-aortic lymphadenectomy at the department of Obstetrics and Gynecology of Pusan National University Hospital. Immunohistochemical studies were performed for glucose transporter 1 (GLUT-1), hexokinase II (HK-II), hypoxia-inducible factor 1α (HIF-1α), vascular endothelial growth factor (VEGF) and carbonic anhydrase IX (CA-IX).

RESULTS

There were positive correlations between FDG uptake and GLUT-1 (r = 0.375, p = 0.0452), and HK-II (r = 0.537, p = 0.0027). However, HIF-1α (r = 0.153, p = 0.4283), VEGF (r = -0,101, p = 0.6032) and CA-IX (r = 0.240, p = 0.2105) were not significantly associated with FDG uptake. No significant correlations were found among the expression levels of biological markers.

CONCLUSION

FDG uptake in endometrial cancer was significantly associated with GLUT-1 and HK-II, while HIF-1α, VEGF and CA-IX were not associated with FDG uptake. No significant correlations were found among the expression levels of biological markers.

Endoglin, VEGF, and its receptors in predicting metastases in endometrial carcinoma

Preoperative evaluation of the risk for metastases in endometrial carcinoma is challenging. The growth of new vessels, angiogenesis, is important for tumor growth and purported to be involved in the metastatic process. The aim of this study was to evaluate the significance of preoperative serum levels and immunohistochemical expression of angiogenic markers in predicting a metastasized disease. Preoperative sera from 98 consecutive women presenting with endometrial carcinoma were collected. Serum concentrations of VEGF, sFLT1, and CD105 were assessed by enzyme-linked immunosorbent assay (ELISA). Immunohistochemistry was used to assess the expression of CD105, VEGF, FLT1, and KDR. The results were correlated to the presence of metastases, presence of deep (≥50%) myometrial invasion, and the histological grade of the tumor. Tumors with other than endometrioid histology were excluded. Of the 80 evaluable patients, 11 had a metastasized disease. The serum concentration of VEGF was higher in the group with metastases than in the group without metastases (median [range], 743 pg/mL [546-1,183 pg/mL] vs. 383 pg/mL [31-1,524 pg/mL], p < 0.001, respectively). In the multivariable analysis, the concentration of VEGF was the sole independent, albeit weak predictive factor for the presence of metastases (odds ratio, 1.004, 95% confidence interval, 1.002-1.007; p = 0.001). The immunohistochemical expression of the markers was not associated with any of the clinicopathological features of the tumors. The results of the present study suggest that preoperative serum VEGF concentration correlates with the presence of metastases in endometrioid endometrial carcinoma.

Antiangiogenic agents in advanced, persistent or recurrent endometrial cancer: a novel treatment option

The limited efficacy of endocrine therapy and chemotherapy has stimulated several researches aimed to detect novel molecularly target therapies for advanced, persistent or recurrent endometrial cancer. Prior attempts to block vascular endothelial growth factor (VEGF) with sunitinib, sorafenib and thalidomide have obtained disappointing results. Bevacizumab has shown a promising activity in a phase II study. The percentages of patients with progression-free survival ≥6 months were similar for endometrioid (35%) and serous carcinoma (36%), but the number of cases was too small to assess the relevance of histological type for response to bevacizumab. In a phase II study, aflibercept was administered every 2 weeks to women with recurrent or persistent disease after chemotherapy. Forty-one percent of the patients were progression-free at 6 months, but 32% of the women had been removed from study because of toxicity. The detection of activating mutations of Fibroblast Growth Factor Receptor (FGFR)-2 in primary endometrial carcinoma has generated a new avenue for the development of molecularly target agents. Dovitinib, a tyrosine kinase inhibitor targeting both VEGF receptor (VEGFR) and FGFRs, is under clinical investigation in different malignancies including endometrial cancer.

Ulinastatin exerts synergistic effects with taxotere and inhibits invasion and metastasis of breast cancer by blocking angiogenesis and the epithelial-mesenchymal transition

Urinary trypsin inhibitor (UTI) ulinastatin as a broad-spectrum protease inhibitor has been widely used to treat acute pancreatitis and shock and to improve the surgical outcome in the clinic. In the present study, we investigated the potential antihuman breast cancer effects of UTI and its combination with taxotere (TXT). Human primary breast cancer cells and breast cancer cell line MDA-MB-231 cells were treated with UTI with or without TXT, and invasion and metastasis ability of these cells were evaluated, respectively, by a transwell assay. Reverse transcription-polymerase chain reaction was used to detect fibroblast growth factor, vascular endothelial growth factor c, epidermal growth factor, epidermal growth factor receptor, transforming growth factor-β1, and protein kinase B/AKT. We also investigated the in vivo role of UTI by using a xenograft mouse model, and immunohistochemical assay was employed to show the expression of factors involved in either angiogenesis or the epithelial-mesenchymal transition (EMT). Our results showed that UTI inhibited invasion and metastasis in both primary and MDA-MB-231 cells both in vivo and in vitro. Especially, UTI presented the significant combined effects with TXT on these cells in terms of angiogenesis blocking and EMT inhibition. These results suggest that UTI and its combination with TXT present therapeutic potential against breast cancer and deserve further preclinical and clinical studies.

A phase II evaluation of aflibercept in the treatment of recurrent or persistent endometrial cancer: a Gynecologic Oncology Group study

OBJECTIVES

Aflibercept targets vascular endothelial growth factor and placental growth factor. We evaluated activity and toxicity of aflibercept in recurrent/persistent endometrial cancer patients. Biomarkers and association with clinical characteristics and outcome were explored.

METHODS

Eligible patients had measurable disease; 1-2 prior cytotoxic regimens; performance status 0-2. Aflibercept 4 mg/kg IV q14 days (28-day cycles) was administered until disease progression or prohibitive toxicity. Primary endpoints were the proportion of patients with progression-free survival at 6 months (PFS6) and tumor response rate. A flexible two-stage group sequential design to detect 20% increases in the proportion of patients responding or enduring PFS6 with 90% power (α=10%) was employed.

RESULTS

Forty-nine patients were enrolled; five were excluded: wrong primary (2), second primary (1), wrong cell type (1); and never treated (1). Median age was 64 (range 48-83). Eighteen patients (41%) had two prior regimens; 27 (61%) had prior radiation. The PFS6 rate was 41%; three patients (7%, 90% CI: 2-17) had partial response. Of note, 10 patients (23%) met the PFS6 endpoint without starting a subsequent therapy; the remaining eight patients discontinued therapy for toxicity and started another therapy before 6 months elapsed. Median PFS and overall survival were 2.9 months and 14.6 months, respectively. Significant grade 3/4 toxicities were: cardiovascular (23%/5%), constitutional (7%/0), hemorrhage (2%/5%), metabolic (7%/2%), and pain (18%/0). Two treatment-related deaths were recorded: GI perforation (1), and arterial rupture (1). FGF1 expression was associated with response.

CONCLUSIONS

Aflibercept met pretrial activity parameters, but was associated with significant toxicity at this dose and schedule in this population.

Analysis of the expression of angiotensin II type 1 receptor and VEGF in endometrial adenocarcinoma with different clinicopathological characteristics

In Poland, endometrial carcinoma takes second place after breast cancer among all cancers in women and is considered the most common genital cancer. It has been repeatedly reported that angiotensin is involved in the development and invasion of some cancers including breast, ovarian, and pancreatic ones. It is suggested that angiotensin two and its receptors are actively involved in tumour biology in endometrial adenocarcinoma. In the present study, we identify a possible relationship between the expression of AT1-R, AT2-R, ERα, and VEGF and clinicopathological characteristics of primary endometrial adenocarcinoma. We determined the above components both at the mRNA (real-time RT-PCR) and protein levels (Western Blot assay). Our results indicate that in patients with grade G3 adenocarcinoma, the expression of AT1-R significantly decreased in comparison with G1 patients (p = 0.034), but the level of ERα was the highest in G2 and the lowest in G3. Moreover, the level of VEGF mRNA significantly increased between G2 and G3 (p = 0.034). We also noted a significant correlation between the expression of AT1-R and AT2-R in FIGO stage 1 (R (s) = 0.9636; p = 0.0001) and that of AT2-R and VEGF (R (s) = 0.5377; p = 0.005). In grade G1 and G2 carcinoma, a significant correlation was also found between the expression of AT1-R and AT2-R (R (s) = 0.9924; p = 0.0001; R (s) = 0.8717, p = 0.0005, respectively), but in grade G1, a negative correlation was observed between AT1-R and VEGF (R (s) = -0.8945, p = 0.0005). Further studies are required to clarify the biological function of the angiotensin receptor in regulating VEGF expression in endometrial carcinoma.

Serum VEGF levels and tissue activation of VEGFR2/KDR receptors in patients with breast and gynecologic cancer

OBJECTIVES

Vascular endothelial cell growth factor (VEGF) plays an important role in the biology of gynecological cancer, usually linked with aggressive tumour behaviour and a poor postoperative outcome. Yet, its role in benign breast/gynecological conditions is less clear.

METHODS

Serum VEGF was analysed in a series of 49 patients with gynecological cancer and 61 patients with benign disease and compared to those of 12 normal female subjects. In addition, the activation status of VEGFR2/KDR receptors was investigated in formalin-fixed paraffin embedded tissues and related to VEGF.

RESULTS

Mean serum levels of VEGF were significantly higher in patients with breast, endometrial and ovarian cancer compared to healthy controls and those with benign breast/gynecologic disease in the respective organs. A similar trend was noted in some cases of simple endometrial hyperplasia, fibroadenoma and fibrocystic disease of the breast. The expression of phosphorylated VEGFR2/KDR receptors was higher in breast, endometrial, ovarian cancer in patients with high VEGF serum levels and this reached a level of statistical significance when all malignancies were combined.

CONCLUSIONS

Serum VEGF levels are increased in patients with breast and gynecological malignancies, but this can not be considered pathognomonic for cancer as it is also increased in certain benign conditions, including cases of fibroadenoma, fibrocystic disease of breast and simple endometrial hyperplasia. Furthermore, high serum VEGF levels are closely related to the activation status of the VEGFR2/KDR receptor in cancer cells, indicating a stimulatory effect of serum VEGF on the VEGF pathway contributing to tumor progression.

Therapeutic advances in women's cancers

Cytotoxic therapy and surgery have improved outcomes for patients with gynecologic malignancies over the last twenty years, but women's cancers still account for over ten percent of cancer related deaths annually. Insights into the pathogenesis of cancer have led to the development of drugs that target molecular pathways essential to tumor survival including angiogenesis, DNA repair, and apoptosis. This review outlines several of the promising new biologically targeted drugs currently being tested to treat gynecologic malignancies.

The CD44+/CD24- phenotype relates to 'triple-negative' state and unfavorable prognosis in breast cancer patients

Breast carcinomas have been reported to contain a subpopulation of CD44+/CD24- tumor cells with stem cell-like properties. This study investigates the significance of these two molecules in connection with tumor aggression and prognosis. The phenotypic profile of 139 breast carcinomas was investigated in paraffin sections using markers previously associated with stem cell-like properties (CD44, CD24), the "triple-state" (ER, PR, c-erb-B2), and angiogenesis (CD31). Tumors with >10% of CD44 and CD24 cancer cells were considered positive. The prevalence of CD44+ and CD24+ breast carcinomas in the series was 51.8% and 41.7%, respectively. Patients with the CD44(+)/CD24(-) phenotype had a 10-year lower median age at presentation and harbored tumors with a triple-negative state. They experienced an unfavorable prognosis. Lack of CD44 expression was associated with lymph node involvement, regardless of CD24 status, whereas the lack of both CD44 and CD24 was connected with high histologic grade and unfavorable prognosis which, notably, was the worse among all phenotypes. In multivariate analysis, the CD44(-)/CD24(-) phenotype, the nodal involvement, the vascular density and the ER-/PR-/c-erbB-2-profile were independent prognostic variables. It is concluded that assessment of the CD44/CD24 status may reveal distinct subgroups of breast cancer patients with different clinical behavior. The unsatisfactory response of the triple-negative tumors to current chemotherapy and their intimate link with the CD44(+)/CD24(-) phenotype, makes CD44 targeting an attractive therapeutic alternative for breast cancer patients. The strong association between the CD44(-)/CD24(-) phenotype and prognosis requires further investigation.

Role of inhibitor of DNA binding-1 protein is related to angiogenesis in the tumor advancement of uterine endometrial cancers

The inhibitor of DNA binding (ID)-1 protein, an inhibitor of basic helix-loop-helix transcription factors, has been found to be involved in multiple cellular functions. In the present study, ID-1 histoscores and mRNA levels were both significantly (p<0.05) increased in uterine endometrial cancers according to clinical stage, histological grade and depth of myometrial invasion. Furthermore, the 60-month survival rate of the 25 patients with high ID-1 was poor (52%), while that of the other 25 patients with low ID-1 was significantly higher (80%) (p<0.05). ID-1 histoscores and mRNA levels significantly (p<0.0001) correlated with microvessel counts in uterine endometrial cancers. Therefore, ID-1 acts on tumor advancement via angiogenic activity and can be considered a candidate prognostic indicator in uterine endometrial cancers.

Hypoxia-inducible factor-1 as a therapeutic target in endometrial cancer management

In the Western world, endometrial cancer (EC) is the most common malignant tumor of the female genital tract. Solid tumors like EC outgrow their vasculature resulting in hypoxia. Tumor hypoxia is important because it renders an aggressive phenotype and leads to radio- and chemo-therapy resistance. Hypoxia-inducible factor-1alpha (HIF-1alpha) plays an essential role in the adaptive cellular response to hypoxia and is associated with poor clinical outcome in EC. Therefore, HIF-1 could be an attractive therapeutic target. Selective HIF-1 inhibitors have not been identified. A number of nonselective inhibitors which target signaling pathways upstream or downstream HIF-1 are known to decrease HIF-1alpha protein levels. In clinical trials for the treatment of advanced and/or recurrent EC are the topoisomerase I inhibitor Topotecan, mTOR-inhibitor Rapamycin, and angiogenesis inhibitor Bevacizumab. Preliminary data shows encouraging results for these agents. Further work is needed to identify selective HIF-1 inhibitors and to translate these into clinical trials.

Overexpression of inhibitor of DNA-binding (ID)-1 protein related to angiogenesis in tumor advancement of ovarian cancers

Background

The inhibitor of DNA-binding (ID) has been involved in cell cycle regulation, apoptosis and angiogenesis. This prompted us to study ID functions in tumor advancement of ovarian cancers.

Methods

Sixty patients underwent surgery for ovarian cancers. In ovarian cancers, the levels of ID-1, ID-2 and ID-3 mRNAs were determined by real-time reverse transcription-polymerase chain reaction. The histoscore with the localization of ID-1 was determined by immunohistochemistry. Patient prognosis was analyzed with a 36-month survival rate. Microvessel counts were determined by immunohistochemistry for CD34 and factor VIII-related antigen.

Results

ID-1 histoscores and mRNA levels both significantly (p < 0.001) increased in ovarian cancers according to clinical stage, regardless of histopathological type. Furthermore, 30 patients with high ID-1 expression had a lower survival rate (53%) compared to patients with low ID-1 expression (80%). ID-1 histoscores and mRNA levels significantly (p < 0.0001) correlated with microvessel counts in ovarian cancers.

Conclusion

ID-1 increased in ovarian cancer cells during tumor progression. Moreover, ID-1 expression levels correlated with microvessel counts. Therefore, ID-1 might work on tumor advancement via angiogenesis and is considered to be a candidate for a prognostic indicator in ovarian cancers.

Current challenges in clinical management of endometrial cancer

Endometrial cancer remains a management challenge. Improved understanding of the mechanisms of carcinogenesis may enable better understanding of biologic behavior and guide therapy. Improvements in diagnostic imaging, radiation delivery systems, and systemic therapies potentially can improve outcomes while minimizing morbidity. Novel strategies for screening and prevention also hold promise for reducing incidence and mortality of this disease.

Expression of the inhibitor of DNA-binding (ID)-1 protein as an angiogenic mediator in tumour advancement of uterine cervical cancers

The ID protein, an inhibitor of basic helix-loop-helix (HLH) transcription factors, has been involved in multiple cellular processes. To investigate the association between tumour advancement and ID expressions of uterine cervical cancers, the levels of ID-1, ID-2 and ID-3 mRNAs were determined by real-time reverse transcription-polymerase chain reaction and the histoscore with the localisation of ID-1 was determined by immunohistochemistry and patient survival in 60 patients. ID-1 histoscores and mRNA levels both significantly (P<0.05) increased in uterine cervical cancers according to clinical stage regardless of histopathological type or lymph node metastasis. Furthermore, the 36-month survival rate of the 30 patients with high ID-1 was poor (60%), whereas that of the other 30 patients with low ID-1 was significantly higher (83%). ID-1 histoscores and mRNA levels significantly (P<0.0001) correlated with microvessel counts in uterine cervical cancers. Tumour cells show mostly diffuse to strong cytoplasmic expression of ID-1 and also very faint expression in endothelial cells. Moreover, ID-1 expression not only correlated with microvessel counts but also correlated significantly with histoscore. Therefore, ID-1 might work on tumour advancement through angiogenic activity and is considered to be a candidate for a prognostic indicator in uterine cervical cancers.

Neoangiogenesis and expression of hypoxia-inducible factor 1alpha, vascular endothelial growth factor, and glucose transporter-1 in endometrioid type endometrium adenocarcinomas

OBJECTIVE

Hypoxia Inducible Factor-1alpha (HIF-1alpha) is a transcriptional factor that activates multiple genes including Vascular Endothelial Growth Factor (VEGF) and glucose transporter-1 (GLUT-1) in response to hypoxia and promotes neoangiogenesis.

METHODS

Expression of HIF-1alpha VEGF, and GLUT-1 were analyzed by immunohistochemistry and microvessel density (MVD) was determined by CD 34 immunostaining in 100 endometrioid type endometrial adenocarcinoma, FIGO Stages I-IV.

RESULTS

High expression of HIF-1alpha, VEGF and GLUT-1 were significantly more prevalent in advanced stages than early stages (p<0.001). High expression of HIF-1alpha was found in 100% of Stage III-IV patients, whereas 50% of Stage II and 9% of Stage I patients had high HIF-1alpha expression. Similarly, high VEGF expression was determined in 4% of Stage I and 30% of Stage II patients, however 90% of Stage III-IV patients had high expression of VEGF. Comparing the GLUT-1 scores, it was found that increasing stages correlated with high GLUT-1 expression. Additionally, a statistically significant difference was also noted in MVD between stages (p<0.001). The average MVD of Stage I patients was 31.87+/-7.73. It was found 49.24+/-7.60 in Stage II, and 78.74+/-14.48 in Stage III-IV patients. On analyzing expression of HIF-1alpha, VEGF and GLUT-1 and MVD in pairs, statistically significant correlations were found between each other (p<0.001).

CONCLUSION

HIF-1alpha was increasingly expressed from early stages through advance stages of endometrioid adenocarcinoma, paralleled by activation of its downstream genes such as GLUT-1, VEGF and increased angiogenesis. These results highlight the importance of hypoxia and related pathways in progression of endometrial carcinoma.

Role of protease activated receptor-2 in tumor advancement of ovarian cancers

BACKGROUND

Protease activated receptor-2 (PAR-2) has been implicated in cellular proliferation, invasion and metastasis with angiogenesis in various tumors. This prompted us to study the role of PAR-2 in tumor advancement of ovarian cancers.

MATERIALS AND METHODS

Forty-eight patients underwent surgery for ovarian cancers. In ovarian cancers, PAR-2 histoscores and mRNA levels were determined by immunohistochemistry and real-time reverse transcription-polymerase chain reaction, respectively. Patient prognosis was analysed with a 36-month survival rate. Microvessel counts were determined by immunohistochemistry for CD31 and factor VIII-related antigen and the rate of cell proliferation was determined by immunohistochemistry for Ki67.

RESULTS

Immunohistochemical staining revealed distribution of PAR-2, dominantly in cancer cells and faintly in stromal cells of the tumor. PAR-2 histoscores in cancer cells and mRNA levels both significantly increased in ovarian cancers with clinical stages (I < II < III < IV, P < 0.05), regardless of histopathological type. The 36-month survival rate of 24 patients with high PAR-2 was poor (58%), while that of the other 24 patients with low PAR-2 was significantly higher (83%). There were significant correlations between PAR-2 histoscores in cancer cells and mRNA levels with microvessel counts and with the rate of cell proliferation in ovarian cancers.

CONCLUSIONS

PAR-2 was up-regulated during ovarian cancer progression. Therefore, PAR-2 might work on tumor advancement of ovarian cancers via angiogenic activity and is considered to be a novel prognostic indicator in ovarian cancers.

Activated VEGFR2/KDR pathway in tumour cells and tumour associated vessels of colorectal cancer

BACKGROUND

Vascular endothelial cell growth factor (VEGF) acts by phosphorylating specific tyrosine kinase receptors on endothelial cell membrane promoting angiogenesis. The study of the activation status of VEGF receptors in human malignancies has recently become feasible by means of specific monoclonal antibodies recognising the phosphorylated form of these receptors.

MATERIALS AND METHODS

In the current study, we investigate the expression of the phosphorylated VEGFR2/KDR receptor in normal colon and colorectal adenocarcinomas in parallel with histopathological parameters, prognosis and the expression of the 'hypoxia inducible factor' HIF1alpha.

RESULTS

pVEGFR2/KDR was weakly expressed in the normal colon, but it was expressed strongly in the cytoplasm and nuclei of cancer cells and in the tumour associated vasculature, mainly at the invading tumour edge. pVEGFR2/KDR expression in cancer cells was significantly associated with a tumour diameter > 6 cm (P = 0.04), poor histological differentiation (P = 0.004) and with high CEF1alpha expression (P = 0.05). High pVEGFR2/KDR expressing vascular density was significantly related with a high VEGF and HIF1alpha expression in cancer cells (P = 0.02 and 0.03, respectively). This was also related significantly to high pVEGFR2/KDR expression in cancer cells. In multivariate analysis, the most significant predictors for death were lympho-vascular invasion (P < 0.001) followed by VEGF (P = 0.014), node status (P = 0.015), standard vascular density (P = 0.022) and necrosis (P = 0.032).

CONCLUSIONS

pVEGFR2 receptors are largely expressed in colon cancer cells and intratumoural vasculature. As VEGF targeting agents enter the clinical practice, the role of monoclonal antibodies recognising the phosphorylated form of VEGF receptors as predictors of response to targeted therapies should be sought in clinicopathological trials.

A phase II trial of thalidomide in patients with refractory leiomyosarcoma of the uterus and correlation with biomarkers of angiogenesis: A gynecologic oncology group study

OBJECTIVES

To evaluate the efficacy and adverse events (AEs) of thalidomide in previously treated, measurable, persistent or recurrent leiomyosarcoma (LMS) of the uterus, and to explore associations between angiogenic markers and treatment or clinical outcome.

METHODS

Eligible, consenting patients were treated until disease progression or toxicity intervened with daily starting dose of 200 mg thalidomide/day that was increased by 200 mg every 2 weeks to a target dose of 1000 mg/day. End-points included progression-free survival (PFS)>or=6 months, toxicity, response, PFS and survival. Vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF) and soluble endothelial protein C receptor (sEPCR) were evaluated in pre- and post-treatment serum and plasma.

RESULTS

Of 30 enrolled patients, one was ineligible (wrong histology). Median age was 56 years. Among 29 eligible patients, seven reached the target dose and only two received more than 4 cycles. Two patients (7%) experienced PFS>or=6 months. There were no objective responses, seven (24%) had stable disease, 19 (66%) progressed and 3 (10%) were not evaluable for response. Median PFS was 1.9 months and median overall survival was 8.3 months. Grade 4 AEs were not observed. The most common grade 3 AEs were neurologic (6), pulmonary (4) and constitutional (3). Treatment with thalidomide was associated with a significant decrease in plasma bFGF (p=0.008) and serum sEPCR (p=0.006), but not in plasma VEGF. Plasma VEGF was associated with increased risk of progression (hazard ratio [HR]=3.5; 95% confidence interval (CI)=1.5-7.8; p=0.003) and death (HR=4.7; 95% CI=1.6-13.8; p=0.005) after adjusting for GOG performance status.

CONCLUSIONS

Thalidomide was not active in patients with uterine LMS and did not alter VEGF concentration. The association between pretreatment VEGF and prognosis in this population supports further evaluation of anti-angiogenic therapies in uterine LMS.

Prognostic significance of VEGF expression in correlation with COX-2, microvessel density, and clinicopathological characteristics in human gastric carcinoma

BACKGROUND

Many studies have shown that angiogenesis plays an important role in the process of cancer development and progression. Vascular endothelial growth factor (VEGF) has a potent angiogenic activity, and cyclooxygenase-2 (COX-2) supports angiogenesis by regulated production of angiogenic factors, including VEGF. The purpose of this study was to examine the expression of VEGF in combination with COX-2 and CD34, their correlation with various clinicopathological factors, and their prognostic significance in human gastric carcinoma.

METHODS

Specimens from 169 patients with different grade and stage gastric carcinoma were investigated by immunohistochemistry for COX-2 and VEGF expression. Tumor microvessel density was assessed with CD34 immunostaining. Correlations between the expression of VEGF, COX-2, CD34, and various clinicopathological factors were studied. The effect of these proteins on patient survival was determined.

RESULTS

COX-2 and VEGF were positively expressed in 36.7% and 50.3% of the patients, respectively. Positive correlation was found between VEGF and COX-2 and between VEGF and CD34. VEGF expression was correlated with depth of invasion; metastatic lymph nodes; lymphatic and venous invasion; and tumor, node, metastasis system stage. Patients with positive staining for VEGF showed far lower disease-free (64.9% vs. 81.3%) and overall (58.3% vs. 76.9%) survival rates than VEGF-negative patients. In multivariate analysis, only tumor location, depth of invasion, and lymph node metastasis were shown to be independent prognostic factors.

CONCLUSIONS

VEGF expression correlates with angiogenesis and tumor progression and is a valuable prognostic factor in patients with gastric carcinoma.

Challenges for patient selection with VEGF inhibitors

As targeted therapies for cancer become increasingly integrated into standard practice, appropriate selection of the patients most likely to benefit from these therapies is now receiving critical scrutiny. Early experience with therapies directed at targets that are definitively overactive (e.g. the bcr-abl tyrosine kinase targeted by imatinib) or over-expressed [e.g. the human epidermal growth factor receptor 2 (HER2) targeted by trastuzumab] has generated the perception that pre-treatment target assessment is a pre-requisite for therapy with all targeted agents. However, emerging evidence suggests that this is not presently feasible for anti-angiogenic agents. Despite considerable evidence for the association of intratumoral and/or plasma vascular endothelial growth factor (VEGF) levels with tumor progression and/or poor prognosis, pre-treatment VEGF levels do not appear to be predictive of response to anti-angiogenic therapy. This may possibly be due to the complexity of the angiogenic pathways and the limitations associated with current methods of VEGF detection and quantification; e.g. low assay sensitivity and lack of standardized methods could prevent detection of very small increases in VEGF, which may be clinically important in patients with tumors that are highly dependent on this growth factor. In addition to a general lack of agreement as to the relative clinical relevance of circulating versus tumor VEGF levels, the absence of a 'gold standard' VEGF detection assay and the lack of a predefined, clinically relevant cut-off pose a significant hindrance to the clinical utility of VEGF measurements for therapy selection. Given the fundamental importance of angiogenesis for tumor growth and progression, and the key role of VEGF in these processes, presently it seems appropriate to view anti-VEGF agents such as bevacizumab (Avastin) as having potential utility, independently of pre-treatment screening. Further research is needed to define the relationship between potential surrogate markers of VEGF pathway activity and clinical outcomes.

A phase II trial of thalidomide in patients with refractory endometrial cancer and correlation with angiogenesis biomarkers: a Gynecologic Oncology Group study

OBJECTIVES

A phase II trial was conducted to evaluate the anti-tumor activity and adverse effects of thalidomide in persistent or recurrent endometrial cancer refractory to cytotoxic chemotherapy and to correlate angiogenesis biomarker expression with clinical outcome.

METHODS

Consenting patients were treated until progression or intolerable toxicity with an oral starting dose of 200 mg thalidomide/day that was to increase by 200 mg every 2 weeks to a target dose of 1000 mg/day. Vascular endothelial growth factor (VEGF), basic fibroblastic growth factor (bFGF), and soluble endothelial protein C receptor (sEPCR) were analyzed by ELISA in pre and post-treatment specimens.

RESULTS

Twenty-four of twenty-seven patients enrolled in the study were eligible, of whom 2 reached the target dose, 8 progressed before achieving the target dose, and 14 refused or had toxicity that prohibited escalation. Two patients (8.3%) remained progression-free>or=6 months. There were 3 (12.5%) with partial responses, 2 (8.3%) with stable disease, 15 (62.5%) with increasing disease, and 4 (16.7%) who were inevaluable for response. Median progression-free survival and overall survival were 1.7 months and 6.3 months, respectively. No grade 4 toxicities were observed. Common grade 3 toxicities included hematologic (n=3), cardiovascular (n=3), constitutional (n=3), and neurologic (n=4). Thalidomide did not decrease VEGF or bFGF levels but reduced sEPCR levels in serum. Elevated plasma vascular endothelial growth factor levels were associated with increased risk of progression and death.

CONCLUSIONS

Thalidomide demonstrated limited ability to delay progression (as measured by PFS at 6 months), produce objective responses, or reduce angiogenic marker levels in chemotherapy refractory endometrial cancer. VEGF level appears to be prognostically significant in such patients, independent of thalidomide treatment.

Lactate dehydrogenase 5 (LDH-5) expression in endometrial cancer relates to the activated VEGF/VEGFR2(KDR) pathway and prognosis

PURPOSE

Lactate dehydrogenase (LDH-5) is a major lactate dehydrogenase isoenzyme catalyzing the transformation of pyruvate to lactate for anaerobic acquisition energy. In this study, the expression of LDH-5 was assessed in the normal and malignant endometrium. Its role in prognosis and tumor angiogenesis and hypoxia was also examined.

EXPERIMENTAL DESIGN

Tissue specimens from 68 patients with clinical stage I endometrial adenocarcinoma of the endometrioid cell type and 20 samples from normally cycling endometrium were investigated immunohistochemically for the expression of LDH-5. The vascular density and the expression of angiogenesis/hypoxia-related proteins (VEGF, HIF1alpha, HIF2alpha, phosphorylated VEGFR2/KDR, VEGF/KDR complex) were also assessed.

RESULTS

Unlike other normal epithelia, the glandular endometrial cells consistently expressed LDH-5 suggesting a role of this enzyme in the normal menstrual cycle. Endometrial adenocarcinomas displayed LDH-5 expression in 31/68 (45.5%) cases with those having a high LDH-5 expression being connected with a low lymphocytic response; this may suggest an important role of LDH-5 and, presumably, lactate release in tumor escape from host immuno-surveillance. More importantly, LDH-5 was significantly associated with the expression of phosphorylated VEGFR2/KDR receptors in cancer cells and tumor-associated vasculature. LDH-5 was one of the most powerful and independent prognostic variables.

CONCLUSIONS

LDH-5 expression is an independent prognostic marker in endometrial cancer, linked with impaired host immune response and activation of VEGFR2/KDR receptors in both cancer cells and tumor-associated vasculature. Adjuvant radio-chemotherapy may, therefore, be useful in these cases, while the administration of VEGF- tyrosine kinase receptor inhibitors emerges as a therapeutic option.

Angiogenesis in colorectal cancer: prognostic and therapeutic implications

Angiogenesis is important for tumor growth and metastasis. This account reviews the clinicopathological studies conducted in the field of angiogenesis in colorectal cancer, the methods of assessing vascular-related characteristics in tissue sections and provides a background for the usefulness of antiangiogenic policies along with chemotherapy and radiotherapy. Highly angiogenic colorectal tumors are associated with aggressive histopathological features and poor patients' survival. Similarly, factors stimulating angiogenesis, such as vascular endothelial growth factor (VEGF), thymidine phosphorylase (TP), and others, are commonly related to increased vascular density (VD) and, therefore, to an unfavorable clinical course. Anti-VEGF agents have improved prognosis in patients with metastatic colorectal cancer, when added to standard chemotherapy. It is expected that, in addition to adjuvant chemotherapy and radiotherapy, agents blocking the stimulatory effect of VEGF on endothelial cells would prove beneficial to the patient.

Lactate dehydrogenase 5 expression in operable colorectal cancer: strong association with survival and activated vascular endothelial growth factor pathway--a report of the Tumour Angiogenesis Research Group

PURPOSE

Lactate dehydrogenase 5 (LDH-5) regulates, under hypoxic conditions, the anaerobic transformation of pyruvate to lactate for energy acquisition. Several studies have shown that serum LDH may be an ominous prognostic marker in malignant tumors. The clinical significance of tissue LDH-5, however, remains largely unexplored.

PATIENTS AND METHODS

We investigated the immunohistochemical expression of LDH-5 in a series of 128 stage II/III colorectal adenocarcinomas treated with surgery alone. In addition, markers of tumor hypoxia (hypoxia-inducible factor 1 alpha [HIF1alpha]), angiogenesis (vascular endothelial growth factor [VEGF] and phosporylated kinase domain receptor [pKDR]/flk-1 receptor) and the tumor vascular density (CD31 positive standard vascular density [sVD] and pKDR positive activated vascular density [aVD]) were assessed.

RESULTS

The expression of LDH-5, together with that of HIF1alpha and pKDR, was both nuclear and cytoplasmic. Assessment, with minimal interobserver variability, was achieved using a previously described scoring system. LDH-5 was significantly associated with HIF1alpha (P = .01), aVD (P = .001) and, particularly, with pKDR expression in cancer cells (P = .0001). Tissue LDH-5 expression was linked with elevated serum LDH levels, but serum levels failed to reflect tissue expression in 71% of LDH-5 positive cases. In univariate analysis tissue LDH-5 was associated with poor survival (P = .0003, HR 15.1), whereas in multivariate analysis this isoenzyme was the strongest independent prognostic factor (P = .0009). VEGF, pKDR, aVD, sVD and vascular invasion were all significantly related to unfavorable prognosis.

CONCLUSION

The immunohistochemical assessment of tissue LDH-5 and pKDR provides important prognostic information in operable colorectal cancer. The strong association between LDH-5 and pKDR expression would justify their use as surrogate markers to screen patients for tyrosine kinase inhibitor therapy.

Phosphorylated KDR expression in endometrial cancer cells relates to HIF1alpha/VEGF pathway and unfavourable prognosis

Vascular endothelial growth factor (VEGF) is a potent angiogenic factor for many malignant neoplasms exerting its function through activation of specific membrane receptors, that is, KDR/flk-1, residing in endothelial cells. Several recent reports indicate that VEGF receptors are also expressed in cancer cells, suggesting that specific VEGF-originated cancer cell reactions may parallel the endothelial response. Using a novel monoclonal antibody, recognizing the activated (phosphorylated) form of the KDR receptor (pKDR), we assessed the expression of pKDR in normal and malignant endometrium. A strong and consistent cytoplasmic and nuclear pKDR expression was noted in the normally cycling endometrium, including epithelial, stromal and endothelial cells, suggesting a role in the normal menstrual cycle. Approximately, one-third of the 70 stage I endometrioid adenocarcinomas analysed exhibited an intense cytoplasmic and nuclear pKDR expression in both cancer cells and peritumoral vessels. It was noted that such pKDR reactivity in cancer cells was related directly to VEGF, VEGF/KDR complexes and HIF1alpha (hypoxia inducible factor 1alpha) expression. Furthermore, pKDR expression was significantly associated with poor prognosis. It is concluded that the VEGF/KDR pathway is activated in both normally cycling and malignant endometrium, suggestive of an important role in the biology of this tissue. The unfavourable prognosis that VEGF confers to endometrial adenocarcinomas could be attributed to its angiogenic activity, but also to a direct effect on cancer cells through an autocrine VEGF/KDR loop.

The role of vascular endothelial growth factor and its receptor Flk-1/KDR in promoting tumour angiogenesis in feline and canine mammary carcinomas: a preliminary study of autocrine and paracrine loops

Vascular Endothelial Growth Factor (VEGF) and its receptor KDR are involved in the regulation of angiogenesis and are up-regulated in a number of tumours in humans and in particular, breast cancer. We therefore evaluated the prognostic potential of the angiogenetic process in feline and canine mammary carcinomas by the immunohistochemical assessment of VEGF expression and micro vessel density (MVD) quantification and examined the interplay between VEGF and KDR. These variables were related to some relevant clinicopathological parameters and to overall survival (OS). VEGF and KDR expression were evaluated in epithelial, stromal and endothelial compartments in order to identify autocrine and/or paracrine loops. In dogs an increased VEGF expression did not show any statistical correlation with the clinicopathological parameters examined and was not correlated to a poorer prognosis. MVD was found to be significantly correlated to the histologic type (P=0.04), tumour grading (P=0.02), and to the OS (P=0.01). In cats VEGF expression was significantly correlated to tumor grading (P=0.01) and OS (P=0.03), while no significant associations were found between MVD and the other parameters. VEGF and KDR were found to be detected on the epithelial, and/or endothelial and/or stromal cells of the carcinomas in both species, suggesting indications for some possible autocrine and paracrine loops. Our results encourage further studies on the possible prognostic role of VEGF and MVD in canine and feline mammary tumours and on the role of growth factors and their receptors in promoting tumour proliferation and an "angiogenetic shift". The VEGF/KDR system may play a role in malignant transformation and tumor progression.

The racial disparity in outcomes in endometrial cancer: could this be explained on a molecular level?

OBJECTIVE

The racial disparities among patients with endometrial carcinoma have been previously reported. The objective of this study is to analyze and compare the molecular profiles in endometrial cancer in Caucasian and African American patients using a number of known molecular markers.

MATERIALS AND METHODS

147 patients diagnosed with endometrial cancer between 1995 and 2001 were included in the study. Patients' demographics, clinical and pathological data were reviewed. Immunohistochemical staining for p53, VEGF, Ki-67 and HIF-1alpha was performed on tissue micro array sections. Tumors' expression of p53, VEGF, Ki-67, and HIF-1alpha was compared based on ethnicity and tumor type (Type I = endometrioid carcinomas and Type II = non-endometrioid carcinomas). Spearman's correlation and Fisher's Exact Tests were used for statistical analysis and Kaplan-Meier, log-rank and Cox regression were used for survival analysis.

RESULTS

97 patients were Caucasian and 50 patients were African American. The mean age was 62 (33-91) years for Caucasian patients and 63.5 (24-89) years for the African American patients. African American patients had more Type II carcinoma than Caucasian patients (P = 0.055). High p53 expression was statistically significant among the African American patients (49% vs. 30%, P = 0.035) versus Caucasian patients. There was no significant difference demonstrated when comparing the VEGF, Ki-67, and HIF-1alpha expression between the racial groups. Survival analysis showed a trend toward a shorter survival in the African American patients compared to the Caucasian patients; median survival 62 versus 77 months (P = 0.061). On the other hand, we did not find a significant difference in survival by ethnicity when we adjusted for tumor histology.

CONCLUSION

While African American patients with endometrial cancer seem to show a trend toward a shorter survival, this seems to be mainly due to the fact that they have a higher proportion of Type II tumors. The molecular profiles for p53, Ki-67, VEGF and HIF-1alpha expression of histologically matched tumors were similar between the two ethnic groups.

Loss of expression and nuclear/cytoplasmic localization of the FOXP1 forkhead transcription factor are common events in early endometrial cancer: relationship with estrogen receptors and HIF-1alpha expression

The FOXP1 gene has been identified as a new member of the winged helix family of transcription factors that have important roles in cellular transformation, differentiation and proliferation. In this study, we examined the expression of FOXP1 in the normal and malignant endometrium (stage I endometrioid adenocarcinoma cases), showing a frequent deregulation of its expression in cancer. Proliferative endometrium showed predominantly nuclear localization of FOXP1, while exclusively weak cytoplasmic staining was present in the secretory phase. Loss of nuclear expression was the most striking event in endometrial adenocarcinoma. Nuclear expression ranged from 0 to 20% (median 0%). Cytoplasmic expression was noted more frequently, ranging from 0 to 90% of cancer cells (median 30%). Overall, 24/82 cases (29.3%) were observed to lack both nuclear and cytoplasmic FOXP1 expression. Tumors with exclusively cytoplasmic expression of FOXP1 were linked with deep myometrial invasion and hypoxia-inducible factors 1alpha (HIF-1alpha) expression. On the other hand, the presence of nuclear FOXP1 expression was significantly linked with ER-alpha reactivity. Survival analysis did not reveal significant differences among patients grouped by FOXP1 expression, presumably due to the high curability of stage I disease. This study provides evidence on pathways to be investigated to elucidate the interplay between FOXP1, ER-alpha and HIF-1alpha in hormone dependent cancers.

The HIF-2alpha/VEGF pathway activation in cutaneous capillary haemangiomas

AIM

To investigate the pathogenesis of capillary haemangiomas, a common form of vascular malformation.

METHODS

Twenty-five cutaneous capillary haemangiomas, excised from patients under 14 years of age, were studied immunohistochemically for endothelial cells, the angiogenic factors thymidine phosphorylase (TP) and vascular endothelial growth factor (VEGF), the proliferation index Ki-67, and the hypoxia inducible factors-1alpha (HIF-1alpha) and -2alpha (HIF-2alpha).

RESULTS

Endothelial-lined channels reacted strongly with CD31 in all cases, clearly definining capillary spaces. Between 5 and 20% of the endothelial cells were Ki-67 positive, indicating an intense proliferative activity; more importantly, they consistently expressed VEGF and HIF-2alpha, and in many cases TP, but failed to react with HIF-1alpha.

CONCLUSION

It is suggested that the activation of the HIF-2alpha pathway and the consequent overexpression of VEGF by the endothelial cells are involved in the pathogenesis of cutaneous capillary haemangiomas.

Histological quantitation of tumour angiogenesis

Tumours establish their blood supply via a number of processes in addition to angiogenesis. These include vasculogenesis, vascular remodelling, intussusception and possibly vascular mimicry in certain tumours. The mainstay of the assessment of tumour vascularity has been counting the number of immunohistochemically identified microvessels in vascular hot spots. Nevertheless, several other techniques are available, including Chalkley counting, vascular grade and the use of image analysis systems. Angiogenic activity can furthermore be assessed in histological samples by measuring the molecules involved in the establishment of the tumour vasculature, including angiogenic growth factors and their receptors, cell adhesion molecules, proteases and markers of activated, proliferating, cytokine stimulated or angiogenic vessels, such as CD105. Measuring the maturity of vessels may give an indication of the proportion of the tumour vasculature that is functional. Other reagents that can identify hypoxia-activated pathways are also being developed. The histological assessment of tumour vascularity is mainly used in the research setting but may also have applications in the clinic if appropriate methodology and trained observers perform the studies. Gene arrays may be able to provide an angiogenesis profile. Continued study into the processes involved in generating a tumour blood supply is likely to identify new markers that may be more accurate measures.