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Background: In the Caribbean region, a notable difference in HPV-prevalence and genotypes distribution between the islands is observed. Recently we found in Curaçao a low incidence of HPV16 and 18 in cervical cancer compared to the standard world population. We aimed to determine HPV-prevalence, HPV-genotype distribution and associated risk-factors in women from Curaçao. Methods: 5000 women aged 25–65 years were randomly selected from the national Population Register. HPV was detected by means of GP5+/6+PCR EIA and GP 5+/6+amplimers from HPV-positive samples were genotyped with a reverse hybridisation assay. We also collected personal data and data on risk-factors. Results: 1075 women were enrolled in the study. Overall HPV-prevalence was 19.7%. Most frequent genotypes were HPV16 (2.3%), 35 (2.1%) and 52 (1.8%). Twenty-seven women detected with abnormal cytology (i.e.≥ASC-US) were referred for biopsy. In women with normal cytology (n = 1048), HPV-prevalence was 17.9% and the most common high-risk HPV (hrHPV)-types were HPV35 (2.0%), 18 (1.8%), 16 (1.5%) and 52 (1.5%). The highest HPV-prevalence (32.8%) was found in the age-group: 25–34 (n = 247). HPV positive women started sex at a younger age (p = 0.032). Conclusions: HPV-prevalence in the overall population is high and HPV16 was the most common genotype followed by 35 and 18. In women with normal cytology HPV35 is the most common genotype followed by HPV18, 52 and 16. The high HPV-prevalence (32.8%) in women of 25–34 years argue for introduction of cervical cancer prevention strategies. HPV-type distribution found in Curaçao should be taken into account when considering the choice for prophylactic vaccination. [ABSTRACT FROM AUTHOR]

Background: Curaçao is a Dutch-Caribbean Island located in a high-risk area for cervical cancer.Prior to introduction of a prophylactic human papillomavirus (HPV) vaccine, knowledge of the prevalence of high-risk HPV vaccine genotypes (HPV16, 18, 31, 33, 45, 52 and 58) in cervical (pre)cancer is required.Objective: To investigate the prevalence of HPV genotypes in invasive cervical cancers (ICC) and cervical intraepithelial neoplasia (CIN) grade 1, 2 and 3 in Curaçao.Methods: Paraffin-embedded blocks of 104 cervical cancers (89 squamous, 15 adenocarcinoma), 41 CIN3, 39 CIN2 and 40 CIN1 lesions were analysed for the presence of HPV. Sections were stained by H&E for histopathological evaluation, and DNA was extracted using proteinase K. HPV genotypes were detected using Short PCR Fragment (SPF10) PCR DNA enzyme immunoassay and a Line Probe Assay (LiPA25) .Results: HPV was found in 92 (88.5%) ICC; 87 (94.6%) had a single HPV infection and 86 (93.5%) were high-risk human papillomavirus (hrHPV)-type positive.The three most common HPV types in ICC were 16 (38.5%), 18 (13.5%) and 45 (6.7%), covering 58.7%.HrHPV vaccine genotypes 16, 18, 31, 35, 45, 52 and 58 were responsible for 73.1% of ICC. For precancerous lesions, the HPV attribution was 85.4% for CIN3, 66.7% for CIN2% and 42.5% for CIN1.Conclusions: Our study, the largest in the Caribbean region in (pre)cancer, shows that the prevalence of HPV-type 16 and 18 in cervical cancer is lower compared with the world population but no differences in prevalence of these two HPV types are seen in precancerous lesions.When considering HPV vaccination in Curaçao, the relatively high contribution of non-HPV 16/18 genotypes in ICC should be taken into account. [ABSTRACT FROM AUTHOR]

In cancer patients pervasive systemic suppression of Dendritic Cell (DC) differentiation and maturation can hinder vaccination efficacy. In this study we have extensively characterized migratory DC subsets from human skin and studied how their migration and T cell-stimulatory abilities were affected by conditioning of the dermal microenvironment through cancer-related suppressive cytokines. To assess effects in the context of a complex tissue structure, we made use of a near-physiological skin explant model. By 4-color flow cytometry, we identified migrated Langerhans Cells (LC) and five dermis-derived DC populations in differential states of maturation. From a panel of known tumor-associated suppressive cytokines, IL-10 showed a unique ability to induce predominant migration of an immature CD14+CD141+DC-SIGN+ DC subset with low levels of co-stimulatory molecules, up-regulated expression of the co-inhibitory molecule PD-L1 and the M2-associated macrophage marker CD163. A similarly immature subset composition was observed for DC migrating from explants taken from skin overlying breast tumors. Whereas predominant migration of mature CD1a+ subsets was associated with release of IL-12p70, efficient Th cell expansion with a Th1 profile, and expansion of functional MART-1-specific CD8+ T cells, migration of immature CD14+ DDC was accompanied by increased release of IL-10, poor expansion of CD4+ and CD8+ T cells, and skewing of Th responses to favor coordinated FoxP3 and IL-10 expression and regulatory T cell differentiation and outgrowth. Thus, high levels of IL-10 impact the composition of skin-emigrated DC subsets and appear to favor migration of M2-like immature DC with functional qualities conducive to T cell tolerance. [ABSTRACT FROM AUTHOR]

Murine L1210 leukaemia cells expressing either the reduced folate carrier (RFC) or the membrane folate receptor (MFR) were studied in vitro and in vivo to assess the dynamics of membrane transport of two categories antifolates; folate-based inhibitors of dihydrofolate reductase (methotrexate, edatrexate, aminopterin, PT523, and PT644) and thymidylate synthase (TS) [CB3717, raltitrexed, plevitrexed (BGC9331), pemetrexed and GW1843]. The potency of in situ inhibition of TS was used as an endpoint to analyze the in vitro dynamics of RFC/MFR-membrane transport of these antifolates. Both for L1210-RFC and L1210-MFR cells, the potency of in situ TS inhibition was closely correlated with increasing affinities of these transporters for the antifolates ( r = 0.64, P < 0.05 and r = −0.65, P < 0.05, respectively). Within the group of antifolates for which MFR had a low binding affinity, those that had the ability to become polyglutamylated, were more potent inhibitors of TS in situ activity than non-polyglutamatable antifolates. In vivo activity of methotrexate, edatrexate, raltitrexed and pemetrexed was assessed in L1210-RFC and L1210-MFR bearing mice that were fed either a standard or a folate-deficient chow. Dietary folate depletion significantly reduced the MTD for methotrexate (sevenfold), edatrexate (sevenfold), raltitrexed (50-fold) and pemetrexed (150-fold). Based on increased life spans, antitumor effects of methotrexate and edatrexate were markedly better in L1210-RFC bearing mice on the folate-deficient chow (ILS: 455 and 544%, respectively) than on standard chow (ILS: 213 and 263%, respectively). No therapeutic effects of methotrexate and edatrexate were observed for L1210-MFR bearing mice on either chow condition, which may be consistent with the low binding affinity for MFR. Irrespective of the folate diet status, pemetrexed and raltitrexed were inactive against both L1210-RFC and L1210-MFR bearing mice, which may be due to high circulating plasma thymidine levels. Collectively, this study underscores that modulation of dietary folate status can provide a basis within which the therapeutic effect of antifolates may be further improved. [ABSTRACT FROM AUTHOR]

The field of tumor vaccination is currently undergoing a shift in focus, from individualized tailor-made vaccines to more generally applicable vaccine formulations. Although primarily predicated by financial and logistic considerations, stemming from a growing awareness that clinical development for wide-scale application can only be achieved through backing from major pharmaceutical companies, these new approaches are also supported by a growing knowledge of the intricacies and minutiae of antigen presentation and effector T-cell activation. Here, the development of whole-cell tumor and dendritic cell (DC)-based vaccines from an individualized autologous set-up to a more widely applicable allogeneic approach will be discussed as reflected by translational studies carried out over the past two decades at our laboratories and clinics in the vrije universiteit medical center (VUmc) in Amsterdam, The Netherlands. [ABSTRACT FROM AUTHOR]

This study explores the effect of 5-fluorouracil (5FU) exposure on mRNA levels of its target enzyme thymidylate synthase (TS) and the rate-limiting catabolic enzyme dihydropyrimidine dehydrogenase (DPD) in tumors of colorectal cancer patients. TS and DPD mRNA levels were determined in primary tumor and liver metastasis samples from patients who were either not pretreated ( n = 29) or given one presurgery bolus of 5FU ( n = 67). In both groups a wide variation in TS mRNA levels was observed. Median TS mRNA expression in 17 primary tumors of exposed patients was 3.0-fold higher than in 19 primary tumors of unexposed patients ( p = 0.015). TS mRNA expression in liver metastasis samples of exposed patients ( n = 16) was also higher (5.2-fold) than that of unexposed patients ( n = 48; p < 0.001). Also DPD mRNA expression displayed a large degree of interpatient variation. No difference in DPD expression in liver metastasis samples was observed between exposed and unexposed patients. However, median DPD mRNA expression in 15 primary tumors of exposed patients was 3.2-fold lower than in 18 primary tumors of unexposed patients ( p = 0.027). In conclusion, administration of 5FU in vivo influences the gene expression of TS and DPD. © 2007 Wiley-Liss, Inc. [ABSTRACT FROM AUTHOR]

Contrary to initial expectations, angiogenesis inhibitors can cause toxicities in patients with cancer. The toxicity profiles of these inhibitors reflect the disturbance of growth factor signalling pathways that are important for maintaining homeostasis. Experiences with angiogenesis inhibitors in clinical trials indicate that short-term toxicities are mostly manageable. However, these agents will also be given in prolonged treatment strategies, so we need to anticipate possible long-term toxicities. In addition, understanding the molecular mechanisms involved in the toxicity of angiogenesis inhibition should allow more specific and more potent inhibitors to be developed. [ABSTRACT FROM AUTHOR]

B-cell lymphoma gene (BCL-6) upregulation contributes to immortalization of mouse embryo fibroblast and primary B cells via upregulation of cyclin D1. As cyclin D1 overexpression is a common phenomenon in different cancers, BCL-6 protein overexpression may not be restricted to lymphomas. In this study, expression of BCL-6 was investigated by immunohistochemistry on paraffin-embedded specimens from 150 breast cancer patients and 10 specimens of normal breast tissue. The results showed BCL-6 overexpression (?10% of cells) in 24/150 (16%) breast cancer patients, whereas in normal breast low expression (<1%) of BCL-6 was observed. In linear regression analysis BCL-6 expression was associated with cyclin D1 (r=0.197, P=0.016). Further, in ?2 analyses, BCL-6-positivity was associated with overexpression of p53 (P=0.016), and hypoxia-inducible factor-1a (P<0.001). Involvement of BCL-6 in breast carcinogenesis is further underscored by comparative genomic hybridization analysis that showed gains at the BCL-6 locus (3q27) in 14/86 (16%) breast cancer tissues. The cases with amplification in BCL-6 showed an increased (25%) incidence of BCL-6 protein overexpression. Thus, this study is the first to show that BCL-6 oncogene activation plays a role in cancers other than lymphomas.Oncogene (2003) 22, 8948-8951. doi:10.1038/sj.onc.1206995 [ABSTRACT FROM AUTHOR]

: PurposeTo determine the ability of 2-deoxy-2-[18F]-fluoro-D-glucose (FDG) positron emission tomography (PET) to monitor response in locally advanced gastroesophageal cancer (LAGEC). Additionally, optimal FDG-PET methods for response monitoring were selected.: ProceduresSequential dynamic FDG-PET scans were performed in 13 patients with LAGEC (T2-3N0-1M0-1a) treated with neoadjuvant cisplatin and gemcitabine plus granulocyte macrophage colony stimulating growth factor at a three weekly schedule. The standard FDG-PET method, nonlinear regression (NLR), was compared with computed tomography (CT), endoscopic-ultrasound (EUS), and histopathology as well as with 21 simplified analytical FDG-PET methods.: ResultsFive out of 12 operated tumors responded histopathologically with less than 10% residual tumorcells (42%). These had a higher decrease in FDG uptake compared with nonresponders (P = 0.008). Early (after two cycles) and late (after completed induction therapy) response evaluation showed a specificity of 86% and 100%, respectively, and a sensitivity of 100%. Both FDG-PET and EUS were superior to CT. From 21 methods analyzing FDG uptake, the quantitative Patlak analysis, the simplified kinetic method (SKM), and the semiquantitative standardized uptake value corrected for bodyweight (SUV-BW) seemed to correlate best with NLR.: ConclusionsFDG-PET reliably predicted response in LAGEC. FDG-PET measurements using Patlak analysis or the more clinical applicable SKM and SUV-BW were acceptable alternatives to NLR. [Copyright &y& Elsevier]

Implements insights into tumor biology and tumor immunology in the treatment of patients with cancer. Failure of surgical resection in treating cancer; Use of systemic chemotherapy to eradicate micro-metastatic disease; Optimization the control of life-threatening micro-metastatic disease.

5-Fluorouracil (5FU) shows a steep dose response curve in several experimental systems, but the clinical use of high doses is hampered by the toxic side effects of this drug. Uridine diphosphoglucose (UDPG) rescue allows an increase in the maximum tolerated dose of 5FU in mice from 100 (FU[sub 100] ) to 150 mg/kg (5FU[sub 150] +UDPG) and the higher dose is more effective than the standard treatment against several tumors. In the present paper we report on the effect of high-dose 5FU on thymidylate synthase (TS) levels and on 5FU incorporation into RNA. In the resistant murine tumor (Colon 26A) high-dose 5FU inhibited TS catalytic activity 8 h after treatment (4-fold; p = 0.00041) and the inhibition persisted until day 3 (p < 10[sup –4] ). Standard-dose 5FU did not significantly inhibit TS activity. In a relatively sensitive tumor (Colon 26-10), there was no difference in the initial extent of TS inhibition by the two 5FU doses, but TS was still inhibited (2-fold) on day 3 after (5FU[sub 150] +UDPG) while it was within the normal range after 5FU[sub 100] . In both tumor types TS activity showed an impressive rebound (3-fold) on days 3–7, and this occurred after both 5FU doses. In Colon 26A, however, a new 5FU injection on day 7 was still able to inhibit TS but not as effectively as the first dose. 5FU incorporation into RNA reached similar peak values (8 pmol/μg RNA) after the two 5FU doses, but the clearance was faster in mice receiving UDPG rescue. We conclude that UDPG does not interfere with the extent of TS inhibition by 5FU, but UDPG allows the use of a higher dose of 5FU resulting in enhanced TS inhibition. UDPG, however, increases 5FU clearance from RNA. In this experimental system the inhibition of TS seems essential in order to obtain a good antitumor activity, while 5FU incorporation into RNA does not seem to play a role in the antitumor activity of 5FU. Since preliminary results indicate that UDPG is well tolerated by patients, the use of higher 5FU doses may improve the response rate of human tumors.Copyright © 2002 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

Application of recombinant adenoviral vectors for cancer gene therapy is currently limited due to lack of specificity for tumor cells. For gastric and esophageal adenocarcinoma, we present here that the relative abundant expression of the primary adenovirus receptor, coxsackie/adenovirus receptor (CAR), on normal epithelium compared to carcinoma favors the transduction of the epithelium. As such, to achieve specific transduction of cancer celIs, targeting approaches are required that ablate the binding of the virus to CAR and redirect the virus to tumor-specific receptors. By immunohistochemistry and reverse transcriptase polymerase chain reaction assays, we demonstrate a marked difference in expression of the human epithelial cell adhesion molecule (EpCAM) between normal and (pre)malignant lesions of the stomach and esophagus. Based on this, we explored the feasibility of using EpCAM to achieve gastric and esophageal adenocarcinoma selective gene transfer. Adenoviral vectors redirected to EpCAM using bispecific antibodies against the adenovirus fiber-knob protein and EpCAM specifically infected gastric and esophageal cancer cell lines. Using primary human cells, an improved ratio of tumor transduction over normal epithelium transduction was accomplished by the EpCAM-targeted vectors. This study thus indicates that EpCAM-targeted adenoviral vectors may be useful for gastric and esophageal cancer-specific gene therapy in patients. [ABSTRACT FROM AUTHOR]

This study was done to arrive at a fast and reliable protocol for assessment of fractional volumes of immunohistochemically stained dendritic cells in lymph nodes. Twenty axillary lymph nodes of patients with locally advanced breast cancer were immuno-histochemically stained with an S100 antibody. Fractional volumes of dendritic cells were assessed by stereology based quantitative immunohistochemistry using an interactive video overlay system including an automated microscope. The gold standard percentage of dendritic cells was the fractional volume of S100 stained cells in 500 fields systematically spread over the whole lymph node. Then, in a computer simulation, different sample sizes (1–200 fields of vision) were tested and the coefficient of variation (CV) for each sample size was calculated. The CV dropped with increasing sample size. A sample size of 100 fields of vision appeared to be optimal. Intra- and interobserver reproducibility appeared to be good (correlation coefficients of 0.95 and 0.86, respectively) when re-analyzing the cases with the established protocol.In conclusion, a fast and reliable assessment of the fractional volume of dendritic cells in lymph nodes is possible with semi-automated quantitative immuno-histochemistry. This method will form the base for further clinical studies into the immunological response in lymph nodes of patients with locally advanced breast cancer. [ABSTRACT FROM AUTHOR]

Determines the level of hypoxia-inducible factor-1 (HIF-1) during breast carcinogenesis and association with other tumor biomarkers. Involvement of gene expression regulation in tumor growth and metastases; Increase of HIF-1 with increased pathologic stage.

In advanced colorectal cancer, liver metastases are a major problem. In patients with liver metastases as the major site of disease hepatic arterial chemotherapy is a valid alternative to systemic treatment. In this review about hepatic arterial chemotherapy we will discuss the theoretical and practical aspects, the results and complications, the selection of patients for hepatic arterial chemotherapy, and its future developments.Copyright © 2000 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

Recombinant adenoviral vectors are attractive in the context of cancer gene therapy because they are capable of delivering genes to a wide variety of tissues. The utility of adenoviruses is limited by their lack of specificity and by the absence of the receptor(s) for these viruses on many tumor cells. Redirecting adenoviral vectors to tissue- or tumor-specific targets can be achieved by using bispecific conjugates produced by chemical linkage of an anti-adenovirus antibody (Ab) and a ligand or Ab directed toward a specific target. To avoid the limitations of chemical conjugates, molecular conjugates of anti-fiber knob and ligand have been proposed. We present here a novel strategy that allows the production of recombinant bispecific single-chain Abs directed at cell surface molecules. A construct was made that encodes a neutralizing anti-adenovirus fiber single-chain Fv (scFv) Ab (S11) fused to a scFv Ab (425) directed against the epidermal growth factor receptor. The fusion protein markedly enhanced the infection efficiency of adenoviral vectors in epidermal growth factor receptor-expressing cell lines. The bispecific scFv could be purified and concentrated after binding of its 6His tag to a nickel column without significant loss of activity. This approach should permit the production of high quantities of active bispecific scFv for in vivo use. The universal design of the construct allows rapid screening for relevant specific scFv directed at cell surface antigens that can be incorporated into adenoviral targeting strategies. [ABSTRACT FROM AUTHOR]

Non-islet-cell tumour-induced hypoglycaemia (NICTH) is, in most cases, attributable to tumour production of insulin-like growth factor II (IGF-II). Tumour-derived IGF-II has a higher than normal molecular weight (big ‘IGF-II’) and an impaired ability to form the normal ternary 150 kD complex with IGF binding protein-3 (IGFBP-3) and the acid-labile subunit (ALS). Consequently, tumoral IGF-II circulates mainly in smaller binary complexes which have a higher bioavailability than the ternary complex. We had the opportunity to analyze IGFs and IGF-related factors in both pre- and post-operative blood, tumour tissue and tumour cyst fluid from a patient with a disseminated haemangiopericytoma and severe hypoglycaemia. In addition, the effect of serum and tumour cyst fluid on autophosphorylation of the insulin receptor was examined. Patient serum contained low levels of IGF-I, IGFBP-3 and ALS, while the concentrations of IGFBP-2 and IGFBP-6 were markedly elevated. The total level of circulating IGF-II was within the normal range, but Biogel P-60 gel filtration of patient serum revealed that 77% of the IGF-II was present in high molecular weight forms (normal: 10–15%), which decreased to 53% after partial removal of the tumour. Most of the IGF-II immunoreactivity in pre- and post-operative patient serum was associated with 50–60 kD complexes with only a minimal contribution (<10%) from the 150 kD complex. Tumour cyst fluid contained excessive amounts of both big IGF-II and IGFBP-6. Northern blot analysis of total mRNA isolated from the tumour demonstrated high expression of the IGF-II gene and abundant 1.1 kb IGFBP-6 transcript, while the genes encoding IGFBP-3, -4 and -5 were only weakly expressed and mRNA of IGFBP-1, -2 and IGF-I could not be detected. mRNAs for the IGF type II receptor could be easily demonstrated, whereas those for the insulin- and IGF type I receptor were hardly detectable. In contrast to patient serum tumour cyst fluid... [ABSTRACT FROM AUTHOR]

Stage III breast cancer encompasses a heterogenous group of patients. According to the American Joint Committee on Cancer (AJCC) these tumors include stage IIIA and stage IIIB disease, the first generally being operable but the second inoperable. Patients with inflammatory breast cancer are also included in stage IIIB disease, and these patients have the worst prognosis. Multidisciplinary therapy has become the treatment of choice for these patients. Primary or neoadjuvant chemotherapy, followed by locoregional therapy, either surgery, radiotherapy or both, is now an accepted strategy. Most patients achieve a response to chemotherapy, resulting in downstaging of the tumor, and 5-year-survival rates have improved from 10–20% with local therapy alone to 30–60% with the multidisciplinary approach. Although many prospective, mainly phase II trials have been performed in stage III breast cancer, the optimal treatment scheme still has to be established. The role of new therapeutic strategies such as high-dose chemotherapy with hematopoietic stem cell rescue and higher dose intensity regimens with hematopoietic growth factors is currently under investigation. This article will review the literature and discuss our own research in this area. [ABSTRACT FROM AUTHOR]