24 research outputs found

    Monocarboxylate transporters 1 and 4 are associated with CD147 in cervical carcinoma

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    Due to the highly glycolytic metabolism of solid tumours, there is an increased acid production, however, cells are able to maintain physiological pH through plasma membrane efflux of the accumulating protons. Acid efflux through MCTs (monocarboxylate transporters) constitutes one of the most important mechanisms involved in tumour intracellular pH maintenance. Still, the molecular mechanisms underlying the regulation of these proteins are not fully understood. We aimed to evaluate the association between CD147 (MCT1 and MCT4 chaperone) and MCT expression in cervical cancer lesions and the clinico-pathological significance of CD147 expression, alone and in combination with MCTs. The series included 83 biopsy samples of precursor lesions and surgical specimens of 126 invasive carcinomas. Analysis of CD147 expression was performed by immunohistochemistry. CD147 expression was higher in squamous and adenocarcinoma tissues than in the non-neoplastic counterparts and, importantly, both MCT1 and MCT4 were more frequently expressed in CD147 positive cases. Additionally, co-expression of CD147 with MCT1 was associated with lymph-node and/or distant metastases in adenocarcinomas. Our results show a close association between CD147 and MCT1 and MCT4 expressions in human cervical cancer and provided evidence for a prognostic value of CD147 and MCT1 co-expression.CP received a PhD fellowship from Fundacao para a Ciencia e Tecnologia (SFRH/BD/27465/2006)

    RKIP Inhibition in cervical cancer Is associated with higher tumor aggressive behavior and resistance to cisplatin therapy

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    Cervical cancer is one of the most common cancers in women worldwide, being high-risk group the HPV infected, the leading etiological factor. The raf kinase inhibitory protein (RKIP) has been associated with tumor progression and metastasis in several human neoplasms, however its role on cervical cancer is unclear. In the present study, 259 uterine cervix tissues, including cervicitis, cervical intraepithelial lesions and carcinomas, were analyzed for RKIP expression by immunohistochemistry. We found that RKIP expression was significantly decreased during malignant progression, being highly expressed in non-neoplastic tissues (54% of the samples; 73/135), and expressed at low levels in the cervix invasive carcinomas (,15% (19/124). Following in vitro downregulation of RKIP, we observed a viability and proliferative advantage of RKIP-inhibited cells over time, which was associated with an altered cell cycle distribution and higher colony number in a colony formation assay. An in vitro wound healing assay showed that RKIP abrogation is associated with increased migratory capability. RKIP downregulation was also associated with an increased vascularization of the tumors in vivo using a CAM assay. Furthermore, RKIP inhibition induced cervical cancer cells apoptotic resistance to cisplatin treatment. In conclusion, we described that RKIP protein is significantly depleted during the malignant progression of cervical tumors. Despite the lack of association with patient clinical outcome, we demonstrate, in vitro and in vivo, that loss of RKIP expression can be one of the factors that are behind the aggressiveness, malignant progression and chemotherapy resistance of cervical cancer.This work was partially supported by the Portuguese Fundacao para a Ciencia e Tecnologia (grant PTDC/SAU-TOX/114549/2009). Olga Martinho and Sara Granja were recipients of PhD fellowships (SFRH/BD/36463/2007 and SFRH/BD/51062/2010, respectively), and Filipe Pinto and Vera Miranda-Goncalves were recipients of research fellowships (UMINHO/BI/016/2011 and SFRH/BI/33503/2008, respectively), both from FCT, Portugal. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. No additional external funding received for this study

    Molecular characterization of EGFR, PDGFRA and VEGFR2 in cervical adenosquamous carcinoma

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    <p>Abstract</p> <p>Background</p> <p>Adenosquamous carcinoma of the uterine cervix is an infrequent but aggressive subtype of cervical cancer. A better understanding of its biological behaviour is warranted to define more accurate prognosis and therapeutic targets. Currently, the blockage of receptor tyrosine kinase (RTKs) activity is an efficient therapeutic strategy for many different cancers. The objective of this study was to investigate EGFR, PDGFRA and VEGFR2 RTKs overexpression and activating gene mutations in a cohort of 30 adenosquamous carcinomas of the uterine cervix.</p> <p>Methods</p> <p>EGFR, PDGFRA and VEGFR2 immunohistochemistry was performed in all samples, followed by DNA isolation from the gross macroscopically dissection of the neoplastic area. Screening for <it>EGFR </it>(exons 18–21) and <it>PDGFRA </it>(exons 12, 14 and 18) mutations was done by PCR – single-strand conformational polymorphism (PCR-SSCP).</p> <p>Results</p> <p>Despite the presence of EGFR immunohistochemical positive reactions in 43% (13/30) of the samples, no <it>EGFR </it>activating mutations in the hotspot region (exons 18–21) were identified. A silent base substitution (CAG>CAA) in <it>EGFR </it>exon 20 at codon 787 (Q787Q) was found in 17 cases (56%). All PDGFRA immunohistochemical reactions were positive and consistently observed in the stromal component, staining fibroblasts and endothelial cells, as well as in the cytoplasm of malignant cells. No activating <it>PDGFRA </it>mutations were found, yet, several silent mutations were observed, such as a base substitution in exon 12 (CCA>CCG) at codon 567 (P567P) in 9 cases and in exon 18 (GTC>GTT) at codon 824 (V824V) in 4 cases. We also observed the presence of base substitutions in intron 14 (IVS14+3G>A and IVS14+49G>A) in two different cases, and in intron 18 (IVS18-50insA) in 4 cases. VEGFR2 positivity was observed in 22 of 30 cases (73.3%), and was significantly associated with lack of metastasis (<it>p </it>= 0.038).</p> <p>Conclusion</p> <p>This is the most extensive analysis of EGFR, PDGFRA and VEGFR2 in cervical adenosquamous carcinomas. Despite the absence of <it>EGFR </it>and <it>PDGFRA </it>activating mutations, the presence of overexpression of these three important therapeutic targets in a subset of cases may be important in predicting the sensitivity of adenosquamous carcinoma to specific anti-RTKs drugs.</p

    Reprogramming energy metabolism and inducing angiogenesis : co-expression of monocarboxylate transporters with VEGF family members in cervical adenocarcinomas

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    Background: Deregulation of cellular energetic metabolism was recently pointed out as a hallmark of cancer cells. This deregulation involves a metabolic reprogramming that leads to a high production of lactate. Lactate efflux, besides contributing for the glycolytic flux, also acts in the extracellular matrix, contributing for cancer malignancy, by, among other effects, induction of angiogenesis. However, studies on the interplay between cancer metabolism and angiogenesis are scarce. Therefore, the aim of the present study was to evaluate the metabolic and vascular molecular profiles of cervical adenocarcinomas, their co-expression, and their relation to the clinical and pathological behavior. Methods: The immunohistochemical expression of metabolism-related proteins (MCT1, MCT4, CD147, GLUT1 and CAIX) as well as VEGF family members (VEGF-A, VEGF-C, VEGF-D, VEGFR-1, VEGFR-2 and VEGFR-3) was assessed in a series of 232 cervical adenocarcinomas. The co-expression among proteins was assessed and the expression profiles were associated with patients’ clinicopathological parameters. Results: Among the metabolism-related proteins, MCT4 and CAIX were the most frequently expressed in cervical adenocarcinomas while CD147 was the less frequently expressed protein. Overall, VEGF family members showed a strong and extended expression with VEGF-C and VEGFR-2 as the most frequently expressed and VEGFR-1 as the less expressed member. Co-expression of MCT isoforms with VEGF family members was demonstrated. Finally, MCT4 was associated with parametrial invasion and HPV18 infection, CD147 and GLUT1 with distant metastasis, CAIX with tumor size and HPV18 infection, and VEGFR-1 with local and lymphnode metastasis. Conclusions: The results herein presented provide additional evidence for a crosstalk between deregulating cellular energetics and inducing angiogenesis. Also, the metabolic remodeling and angiogenic switch are relevant to cancer progression and aggressiveness in adenocarcinomas.CP received a post-doctoral fellowship (SFRH/BPD/69479/2010) and FM-S received a doctoral fellowship (SFRH/BD/87139/2012) from FCT (Portuguese Foundation for Science and Technology). This work was supported by the FCT grant ref. PTDC/SAU-FCF/104347/2008, under the scope of "Programa Operacional Tematico Factores de Competitividade" (COMPETE) of "Quadro Comunitario de Apoio III" and co-financed by Fundo Comunitario Europeu FEDER, and also by FAPESP 2008/03232-1

    Effect of Tamoxifen and Raloxifene on the Proliferative Activity of the Breast Epithelium in Premenopausal Women

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    Objectives To compare the effects of tamoxifen and raloxifene on the proliferative activity of normal breast tissue in premenopausal women as measured by Ki-67/MIB-1 expression. Study Design A total of 48 women with benign breast nodules and a recommendation for surgical removal of the lesion took part in this study. They were randomized to use tamoxifen or raloxifene for 22 days, after which they were submitted to surgery. During the surgical procedure, a 1-cm fragment of normal breast tissue was removed to study Ki-67 expression. Results The mean percentage ratios between immunolabeled and non-labeled cells were 2.02 ± 1.09 and 3.13 ± 3.23 for the tamoxifen and raloxifene groups, respectively. There was no statistically significant difference between the tamoxifen ( n = 16) and raloxifene ( n = 14) groups in relation to the immunohistochemical analysis of Ki-67 ( P = 0.205). Conclusion The results of this study showed no difference between tamoxifen and raloxifene with respect to the potential of these drugs to reduce the proliferative activity of the normal breast epithelium in premenopausal women
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