José López-guerrero - Academia.edu (original) (raw)
Papers by José López-guerrero
Cancer Genetics and Cytogenetics, 2007
Synovial sarcomas (SS) are infrequent and morphologically heterogeneous soft tissue sarcomas. The... more Synovial sarcomas (SS) are infrequent and morphologically heterogeneous soft tissue sarcomas. The t(X;18)(p11.2;q11.2), which results in fusion of the SYT gene at 18q11 with the SSX1, SSX2, or (rarely) SSX4 gene is a primary genetic event in 90% of SS. To determine whether the t(X;18) present in the original tumor is maintained in its passages, a dual-color break-apart FISH assay for SYT gene disruption was performed in two tissue microarrays (TMA) comprising eight molecularly confirmed primary SSs and their xenografts, which were followed for several generations. A simplified scoring system was applied to the FISH results of the primary and xenotransplanted SS to classify the FISH data into distinct groups. SYT disruption was identified in all eight primary SS and in all their passages without any significant differences among them, despite wide variations in xenotransplantation time between the primary tumors and their xenografts. The TMA-based FISH assay demonstrated genetic stability related to SYT gene rearrangement in primary and xenografted SS.
Endocytosis is a pathway used by viruses to enter cells that can be classified based on the prote... more Endocytosis is a pathway used by viruses to enter cells that can be classified based on the proteins involved, such as dynamin, clathrin or caveolin. Although the entry of herpes simplex type 1 (HSV-1) by endocytosis has been documented in different cell types, its dependence on clathrin has not been described whereas its dependence on dynamin has been shown according to the cell line used. The present work shows how clathrin-mediated endocytosis (CME) is one way that HSV-1 infects the human oligodendroglial (HOG) cell line. Partial dynamin inhibition using dynasore revealed a relationship between decrease of infection and dynamin inhibition, measured by viral titration and immunoblot. Co-localization between dynamin and HSV-1 was verified by immunofluorescence at the moment of viral entry into the cell. Inhibition by chlorpromazine revealed that viral progeny also decreased when clathrin was partially inhibited in our cell line. RT-qPCR of immediately early viral genes, specific entry assays and electron microscopy all confirmed clathrin's participation in HSV-1 entry into HOG cells. In contrast, caveolin entry assays showed no effect on the entry of this virus. Therefore, our results suggest the participation of dynamin and clathrin during endocytosis of HSV-1 in HOG cells.
BMC Medical Genetics, 2011
Background Germline mutations in either of the two tumor-suppressor genes, BRCA1 and BRCA2, accou... more Background Germline mutations in either of the two tumor-suppressor genes, BRCA1 and BRCA2, account for a significant proportion of hereditary breast and ovarian cancer cases. Most of these mutations consist of deletions, insertions, nonsense mutations, and splice variants, however an increasing number of large genomic rearrangements have been identified in these genes. Methods We analysed BRCA1 and BRCA2 genes by direct sequencing and MLPA. We confirmed the results by an alternative MLPA kit and characterized the BRCA1 deletion by Array CGH. Results We describe the first case of a patient with no strong family history of the disease who developed early-onset bilateral breast cancer with a de novo complete BRCA1 gene deletion in the germinal line. The detected deletion started from the region surrounding the VAT1 locus to the beginning of NBR1 gene, including the RND2, ΨBRCA1, BRCA1 and NBR2 complete genes. Conclusion This finding supports the large genomic rearrangement screening o...
The 2014 OECI Oncology Days was held at the &... more The 2014 OECI Oncology Days was held at the 'Prof. Dr. Ion Chiricuta' Oncology Institute in Cluj, Romania, from 12 to 13 June. The focus of this year's gathering was on developments in personalised medicine and other treatment advances which have made the cost of cancer care too high for many regions throughout Europe.
Oncotarget, Jan 27, 2015
Identifying patients who may benefit from targeted therapy is an urgent clinical issue in prostat... more Identifying patients who may benefit from targeted therapy is an urgent clinical issue in prostate cancer (PCa). We investigated the molecular relationship between TMPRSS2-ERG (T2E) fusion gene and insulin-like growth factor receptor (IGF-1R) to optimize the use of IGF-1R inhibitors.IGF-1R was analyzed in cell lines and in radical prostatectomy specimens in relation to T2E status. ERG binding to IGF-1R promoter was evaluated by chromatin immunoprecipitation (ChIP). Sensitivity to anti-IGF-1R agents was evaluated alone or in combination with anti-androgen abiraterone acetate in vitro at basal levels or upon ERG modulation.IGF-1R analysis performed in PCa cells or clinical samples showed that T2E expression correlated with higher IGF-1R expression at mRNA and protein levels. Genetic modulation of ERG directly affected IGF-1R protein levels in vitro. ChIP analysis showed that ERG binds IGF-1R promoter and that promoter occupancy is higher in T2E-positive cells. IGF-1R inhibition was mo...
Seminars in diagnostic pathology, 2006
In less than half a decade, gastrointestinal stromal tumors (GIST) have emerged from historical a... more In less than half a decade, gastrointestinal stromal tumors (GIST) have emerged from historical anonymity to become a model of kinase-targeted therapies. Approximately 80% to 85% of GISTs harbor activating mutations of the KIT or PDGFRA tyrosine kinase genes, and such mutations have predictive and prognostic value. In this regard, the in vitro and in vivo models have provided valuable tools for understanding the molecular pathology of this interesting neoplasm. This review charts particular aspects in the field of cell cultures and tumor xenografts in nude mice in GIST and their implication in the establishment of appropriate models for discovering and testing therapy. The cytogenetic features of these tumors are also discussed. Classic karyotyping, loss of heterozygosity, fluorescent in situ hybridization, comparative genomic hybridization (CGH), and CGH-array analyses have shown that chromosomal numerical abnormalities and loss of genetic material at chromosomes 1p, 9p, 14q, and 2...
International journal of cancer. Journal international du cancer, 2006
The authors analyzed the HER2 status in early-stage nonrecurrent and recurrent breast cancer grou... more The authors analyzed the HER2 status in early-stage nonrecurrent and recurrent breast cancer groups following breast-conserving treatment. Retrospective analyses of a group of 36 invasive early breast cancer (IBC) patients who developed a local recurrence as a first event and of a random control group of 69 IBC patients were made. HER2 status was assessed by the HercepTest and fluorescence in situ hybridization. The Kaplan-Meier proportional log-rank test was used to study the impact of the biological factors on the metastasis-free interval (MFI) and the overall survival (OS). The Cox proportional hazards model, using stepwise selection was performed to identify the independent predictors of poor outcome. The median time of follow-up was 156 months (range: 22-230) for the nonrecurrent group of patients and 119 months (range: 36-228) for the recurrent group. No significant differences between either group were observed in terms of either patient or tumor characteristics, or of HER2 e...
Diagnostic molecular pathology : the American journal of surgical pathology, part B, 2005
The c-KIT and the platelet-derived growth factor receptor alpha (PDGFRalpha) have been shown to b... more The c-KIT and the platelet-derived growth factor receptor alpha (PDGFRalpha) have been shown to be important for tumor growth and progression in several soft-tissue sarcomas, including synovial sarcomas (SSs). It has been suggested that these c-KIT-positive cases might benefit from a tyrosine kinase inhibitor therapy. In this study, we analyze a series of SSs to investigate the presence of c-KIT and PDGFRalpha mutations with the aim of selecting those for a more adequate and appropriate therapy. We analyzed fresh-frozen tissues from 12 SSs (8 primary tumors and 4 nude mice xenotransplants from primary tumors). RNA was extracted to identify the presence of the SYT-SSX gene fusion to confirm the SS diagnosis. Mutational analysis of exons 9, 11, 13, and 17 of c-KIT and exons 12 and 18 of PDGFRalpha was performed by direct sequencing. Immunohistochemical analysis of c-KIT, PDGFRalpha, and p-PDGFRalpha was also performed. All analyzed cases showed the presence of SYT-SSX gene fusion tran...
The EWS-ETS rearrangements, and their respective fusion gene products, are specifically associate... more The EWS-ETS rearrangements, and their respective fusion gene products, are specifically associated with histopathologically Ewing family tumors (EFT). These translocations are implicated in generating malignant transformation of EFT, but the presence of additional genetic alterations must be considered in the pathogenesis of such tumors. We analyzed 26 samples (biopsies and/or nude mice xenotransplants) collected from 19 patients with an EFT to determine whether molecular and cytogenetic alterations of the G 1 /S checkpoint genes are implicated in the pathogenesis of EFT. We found inactivating p53 mutations in three (16%) cases, which correlated with a loss of p21 WAF1/Cip1 expression and with a monosomy of chromosome 17 in two cases. Homozygous deletion of the p16 INK4A /p14 ARF gene was detected in four (21%) cases, three with codeletion of the p15 INK4B gene and with chromosome 9 abnormalities. In all of these cases, expression of the implicated genes was absent. Hypermethylation of the p16 INK4A and p15 INK4B genes was detected in two (10%) and three (16%) cases, respectively, and was correlated with a low level of gene expression. Neither cyclin D1, nor MDM2 and CDK4 amplification was observed. Kaplan-Meier analysis showed that patients with tumors carrying homozygous deletion of the 9p21 locus, or point mutations of the p53 gene, had poorer outcomes than those without these molecular alterations (p ϭ 0.005). In conclusion, 58% (11 of 19) of the analyzed patients showed genetic or epigenetic alterations in either the 9p21 locus or p53 tumor suppressor genes, defining a subgroup of patients with poor clinical outcome. This fact points to an important role of the G 1 /S cell cycle checkpoint dysregulation in the pathogenesis of EFT. (Lab Invest 2001, 81:803-814).
Arkhiv patologii
There is a growing clinical demand for analysis of the HER2/c-erbB-2 (HER2) status of breast canc... more There is a growing clinical demand for analysis of the HER2/c-erbB-2 (HER2) status of breast cancer specimens because it provides valuable prognostic, predictive and therapeutic information. In this sense, a variety of methods is available for detection of HER2 status, although to date a reliable and sensitive test does not exist. In order to choose the most suitable procedure to assess HER2 status, we analyzed 102 invasive breast cancers for HER2 overexpression by means of immunohistochemistry (IHC), with the CB11 Mo-Ab and the Hercep Test kit, and for HER2 gene amplification by fluorescence in situ hyubridization (FISH) and differential PCR (dPCR). HER2 overexpression, determined by CB11 (group C) and HercepTest (2+ and 3+), was observed in 19 samples (18.6%) whereas genetic amplification was detected in 31 (30.4%) and 14 (13.7%) cases by FISH and dPCR, respectively. The majority of overexpressed/amplified specimens corresponded to high grade tumors. We found concordances of 78-80...
Archivos españoles de urología, 2014
Identification of biomarkers that, at the time of diagnosis of prostate cancer (PCa), are associa... more Identification of biomarkers that, at the time of diagnosis of prostate cancer (PCa), are associated with presence of disease or a more aggressive behavior will transform the clinical management of this disease. If both patients and clinicians would have reproducible and valid tools to estimate the specific risk of morbidity associated with PCa, then many patients would opt to and join active surveillance (AS) protocols, and consequently costs and comorbidities associated with the current overtreatment of prostate cancer would be reduced. Thus, a biomarker, or a panel of biomarkers, with high specificity to identify patients at risk for progression in AS protocols, would identify those men who could benefit from less intensive AS protocols with less repeated biopsies, so reducing the risk and cost of these invasive procedures. In this review we try to offer an overview of the new markers identified by genomic techniques and to discuss their potential role in an AS context. Moreover,...
Seminars in Diagnostic Pathology, 2013
Dermatofibrosarcoma protuberans (DFSP) is a rare superficial tumor characterized by high rates of... more Dermatofibrosarcoma protuberans (DFSP) is a rare superficial tumor characterized by high rates of local recurrence and low risk of metastasis. DFSP occurs most commonly on the trunk and proximal extremities, affects all races, and often develops between the second and fifth decade of life. The tumor grows slowly, typically over years. Histologically, several variants of DFSP have been described and should be well characterized to avoid misdiagnosis with other tumors. These include pigmented (Bednar tumor), myxoid, myoid, granular cell, sclerotic, atrophic DFSP, giant cell fibroblastoma, and DFSP with fibrosarcomatous areas. Of all these variants, only the DFSP with fibrosarcomatous areas is high grade, with a higher rate of local recurrence and distant metastasis. DFSP is genetically characterized by the t(17;22)(q22;q13), resulting in the fusion of alpha chain type 1 of collagen gene and platelet-derived growth factor beta gene. This translocation is present in 90% of DFSP and represents a very useful tool in the differential diagnosis of DFSP with other tumors with similar histology. The standard treatment is wide local excision with at least a 2-cm margin. However, local recurrence after apparently adequate surgical excision is well recognized. Mohs micrographic surgery would be the treatment of choice with a better cure rate and maximal conservation of tissue. When surgery is insufficient, clinical evidence has suggested that imatinib mesylate is a safe and effective treatment in DFSP, especially in cases of local advanced or metastatic disease. This article presents an overview of the state of the art in the clinicopathological management of this disease.
Journal of The European Academy of Dermatology and Venereology - J EUR ACAD DERMATOL VENEREOL, 2008
International Journal of Surgical Pathology, 2011
Gastrointestinal stromal tumors (GISTs) are c-KIT-signaling-driven mesenchymal tumors of the huma... more Gastrointestinal stromal tumors (GISTs) are c-KIT-signaling-driven mesenchymal tumors of the human digestive tract, many of which have c-KIT or PDGFRα activating mutations. The authors studied the immunohistochemical markers, c-KIT and PDGFRα mutations, in GISTs and their association with the clinicopathological and clinical follow-up in 145 GISTs. Tumors were located mainly in the stomach, the median tumor size being 7.5 cm. The mitotic index was ≤5 mitoses per 50 high-power fields in 61% of cases, 96% expressed CD117, and c-KIT or PDGFRα mutations were detected in 68% of cases. The median follow-up of the series was 52 months (range = 1 to 244.9 months). Tumor size, cell morphology, mitotic index, incomplete resection, Fletcher's risk classification, Ki-67 overexpression, and c-KIT mutations were associated with progression-free survival. Incomplete resection and mitotic activity also provide information about overall survival. In conclusion, complete clinicopathological, immunohistochemical, and genetic descriptions are necessary to characterize this disease and optimize its clinical management.
Journal of the American …, 2011
Aim To review the clinical and histological data of 20 cases of dermatofibrosarcoma protuberans p... more Aim To review the clinical and histological data of 20 cases of dermatofibrosarcoma protuberans presenting at two dermatology centres in Lisbon from 1978 to 1998.
Annals of Oncology, 2010
Background: To assess whether deletions involving codons 557 and/or 558 (critical deletions) of e... more Background: To assess whether deletions involving codons 557 and/or 558 (critical deletions) of exon 11 of KIT are relevant in the prognosis of relapse-free survival (RFS) in gastrointestinal stromal tumor (GIST) patients with a long follow-up. Patients and methods: A univariate and multivariate analysis for RFS were carried out on 162 localized GIST patients over the entire follow-up period and over the intervals 0-4 years and >4 years. Factors assessed among others were Fletcher/National Institutes of Health and Miettinen-Lasota/Armed Forces Institute of Pathology (M-L/ AFIP) risk categories, critical deletions and non-deletion-type mutation (NDTM) within exon 11 of KIT.
Genes, …, 2010
Very little is known about the genetics of fibrosarcoma (FS) of bone. We applied array comparativ... more Very little is known about the genetics of fibrosarcoma (FS) of bone. We applied array comparative genomic hybridization (CGH) to identify genes and genomic regions with potential role in the pathogenesis of this tumor. Seventeen patients with FS of bone were included in the study. Array CGH analysis was carried out in 13 fresh frozen tissue specimens from 11 of these patients (nine primary tumors and four local recurrences). DNA was extracted and hybridizations were performed on Agilent 244K CGH oligoarrays. The data were analyzed using Agilent DNA Analytics Software. The number of changes per patient ranged from 0 to 132 (average ¼ 43). Losses were most commonly detected at 6q, 8p, 9p, 10, 13q, and 20p. CDKN2A was homozygously deleted in 7/11 patients. Hypermethylation of both p16 INK4a and p14 ARF was found in 1/14 patients. An internal deletion of STARD13 was found in a region with common losses at 13q13.1. The most frequent gains were seen at 1q, 4q, 5p, 8q, 12p, 15q, 16q, 17q, 20q, 22q, and Xp. Single recurrent high level amplification was detected at 4q12, including KIT, PDGFRA, and KDR. No activating mutations were found in any of them. Immunohistochemistry revealed expression of PDGFRA and/or PDGFRB in 12/17 samples. Moreover, small regions of gains pinpointed genes of particular interest, such as IGF1R at 15q26.3 and CHD1L at 1q21.1. In conclusion, our analysis provided novel findings that can be exploited when searching for markers for diagnosis and prognosis, and targets of therapy in this tumor type. in Wiley InterScience (www.interscience.wiley.com).
Diagnostic Molecular …, 2004
Advertisement. Close Window. Close Window. Thank you for choosing to subscribe to the eTOC for Di... more Advertisement. Close Window. Close Window. Thank you for choosing to subscribe to the eTOC for Diagnostic Molecular Pathology. Enter your Email address: Wolters Kluwer Health may email you for journal alerts and information ...
Laboratory …, 2003
Chondrosarcomas are malignant cartilage-forming tumors that represent the second most common mali... more Chondrosarcomas are malignant cartilage-forming tumors that represent the second most common malignant solid tumor of bone. These biologically poorly understood neoplasms vary considerably in clinical presentation and biologic behavior. Chemotherapy and radiation therapy are ...
Actas Dermo-Sifiliográficas, 2006
El dermatofibrosarcoma protuberans (DFSP) es un tumor poco frecuente, de malignidad intermedia, c... more El dermatofibrosarcoma protuberans (DFSP) es un tumor poco frecuente, de malignidad intermedia, con una baja incidencia de metástasis, pero con alta frecuencia de recurrencia local. El diagnóstico histológi-co de este tumor en ocasiones puede resultar difícil, y es necesario en estos casos realizar un estudio inmunohistoquímico para diferenciarlo de dermatofibromas atípicos y de otros sarcomas 1,2 . Sin embargo, estas técnicas no siempre son suficientes para establecer un diagnóstico adecuado. Recientemente, se han descrito en el DFSP rasgos citogenéticos específicos como la translocación recíproca t(17;22)(q22; q13) o, más a menudo, cromosomas supernumerarios en anillo derivados de la t(17;22) 3 . Como consecuencia de esta translocación, se produce una fusión génica entre el gen del colágeno tipo I␣ (COL1A1), en el cromosoma 17q, con el gen de la cadena  del factor de creci-
Cancer Genetics and Cytogenetics, 2007
Synovial sarcomas (SS) are infrequent and morphologically heterogeneous soft tissue sarcomas. The... more Synovial sarcomas (SS) are infrequent and morphologically heterogeneous soft tissue sarcomas. The t(X;18)(p11.2;q11.2), which results in fusion of the SYT gene at 18q11 with the SSX1, SSX2, or (rarely) SSX4 gene is a primary genetic event in 90% of SS. To determine whether the t(X;18) present in the original tumor is maintained in its passages, a dual-color break-apart FISH assay for SYT gene disruption was performed in two tissue microarrays (TMA) comprising eight molecularly confirmed primary SSs and their xenografts, which were followed for several generations. A simplified scoring system was applied to the FISH results of the primary and xenotransplanted SS to classify the FISH data into distinct groups. SYT disruption was identified in all eight primary SS and in all their passages without any significant differences among them, despite wide variations in xenotransplantation time between the primary tumors and their xenografts. The TMA-based FISH assay demonstrated genetic stability related to SYT gene rearrangement in primary and xenografted SS.
Endocytosis is a pathway used by viruses to enter cells that can be classified based on the prote... more Endocytosis is a pathway used by viruses to enter cells that can be classified based on the proteins involved, such as dynamin, clathrin or caveolin. Although the entry of herpes simplex type 1 (HSV-1) by endocytosis has been documented in different cell types, its dependence on clathrin has not been described whereas its dependence on dynamin has been shown according to the cell line used. The present work shows how clathrin-mediated endocytosis (CME) is one way that HSV-1 infects the human oligodendroglial (HOG) cell line. Partial dynamin inhibition using dynasore revealed a relationship between decrease of infection and dynamin inhibition, measured by viral titration and immunoblot. Co-localization between dynamin and HSV-1 was verified by immunofluorescence at the moment of viral entry into the cell. Inhibition by chlorpromazine revealed that viral progeny also decreased when clathrin was partially inhibited in our cell line. RT-qPCR of immediately early viral genes, specific entry assays and electron microscopy all confirmed clathrin's participation in HSV-1 entry into HOG cells. In contrast, caveolin entry assays showed no effect on the entry of this virus. Therefore, our results suggest the participation of dynamin and clathrin during endocytosis of HSV-1 in HOG cells.
BMC Medical Genetics, 2011
Background Germline mutations in either of the two tumor-suppressor genes, BRCA1 and BRCA2, accou... more Background Germline mutations in either of the two tumor-suppressor genes, BRCA1 and BRCA2, account for a significant proportion of hereditary breast and ovarian cancer cases. Most of these mutations consist of deletions, insertions, nonsense mutations, and splice variants, however an increasing number of large genomic rearrangements have been identified in these genes. Methods We analysed BRCA1 and BRCA2 genes by direct sequencing and MLPA. We confirmed the results by an alternative MLPA kit and characterized the BRCA1 deletion by Array CGH. Results We describe the first case of a patient with no strong family history of the disease who developed early-onset bilateral breast cancer with a de novo complete BRCA1 gene deletion in the germinal line. The detected deletion started from the region surrounding the VAT1 locus to the beginning of NBR1 gene, including the RND2, ΨBRCA1, BRCA1 and NBR2 complete genes. Conclusion This finding supports the large genomic rearrangement screening o...
The 2014 OECI Oncology Days was held at the &... more The 2014 OECI Oncology Days was held at the 'Prof. Dr. Ion Chiricuta' Oncology Institute in Cluj, Romania, from 12 to 13 June. The focus of this year's gathering was on developments in personalised medicine and other treatment advances which have made the cost of cancer care too high for many regions throughout Europe.
Oncotarget, Jan 27, 2015
Identifying patients who may benefit from targeted therapy is an urgent clinical issue in prostat... more Identifying patients who may benefit from targeted therapy is an urgent clinical issue in prostate cancer (PCa). We investigated the molecular relationship between TMPRSS2-ERG (T2E) fusion gene and insulin-like growth factor receptor (IGF-1R) to optimize the use of IGF-1R inhibitors.IGF-1R was analyzed in cell lines and in radical prostatectomy specimens in relation to T2E status. ERG binding to IGF-1R promoter was evaluated by chromatin immunoprecipitation (ChIP). Sensitivity to anti-IGF-1R agents was evaluated alone or in combination with anti-androgen abiraterone acetate in vitro at basal levels or upon ERG modulation.IGF-1R analysis performed in PCa cells or clinical samples showed that T2E expression correlated with higher IGF-1R expression at mRNA and protein levels. Genetic modulation of ERG directly affected IGF-1R protein levels in vitro. ChIP analysis showed that ERG binds IGF-1R promoter and that promoter occupancy is higher in T2E-positive cells. IGF-1R inhibition was mo...
Seminars in diagnostic pathology, 2006
In less than half a decade, gastrointestinal stromal tumors (GIST) have emerged from historical a... more In less than half a decade, gastrointestinal stromal tumors (GIST) have emerged from historical anonymity to become a model of kinase-targeted therapies. Approximately 80% to 85% of GISTs harbor activating mutations of the KIT or PDGFRA tyrosine kinase genes, and such mutations have predictive and prognostic value. In this regard, the in vitro and in vivo models have provided valuable tools for understanding the molecular pathology of this interesting neoplasm. This review charts particular aspects in the field of cell cultures and tumor xenografts in nude mice in GIST and their implication in the establishment of appropriate models for discovering and testing therapy. The cytogenetic features of these tumors are also discussed. Classic karyotyping, loss of heterozygosity, fluorescent in situ hybridization, comparative genomic hybridization (CGH), and CGH-array analyses have shown that chromosomal numerical abnormalities and loss of genetic material at chromosomes 1p, 9p, 14q, and 2...
International journal of cancer. Journal international du cancer, 2006
The authors analyzed the HER2 status in early-stage nonrecurrent and recurrent breast cancer grou... more The authors analyzed the HER2 status in early-stage nonrecurrent and recurrent breast cancer groups following breast-conserving treatment. Retrospective analyses of a group of 36 invasive early breast cancer (IBC) patients who developed a local recurrence as a first event and of a random control group of 69 IBC patients were made. HER2 status was assessed by the HercepTest and fluorescence in situ hybridization. The Kaplan-Meier proportional log-rank test was used to study the impact of the biological factors on the metastasis-free interval (MFI) and the overall survival (OS). The Cox proportional hazards model, using stepwise selection was performed to identify the independent predictors of poor outcome. The median time of follow-up was 156 months (range: 22-230) for the nonrecurrent group of patients and 119 months (range: 36-228) for the recurrent group. No significant differences between either group were observed in terms of either patient or tumor characteristics, or of HER2 e...
Diagnostic molecular pathology : the American journal of surgical pathology, part B, 2005
The c-KIT and the platelet-derived growth factor receptor alpha (PDGFRalpha) have been shown to b... more The c-KIT and the platelet-derived growth factor receptor alpha (PDGFRalpha) have been shown to be important for tumor growth and progression in several soft-tissue sarcomas, including synovial sarcomas (SSs). It has been suggested that these c-KIT-positive cases might benefit from a tyrosine kinase inhibitor therapy. In this study, we analyze a series of SSs to investigate the presence of c-KIT and PDGFRalpha mutations with the aim of selecting those for a more adequate and appropriate therapy. We analyzed fresh-frozen tissues from 12 SSs (8 primary tumors and 4 nude mice xenotransplants from primary tumors). RNA was extracted to identify the presence of the SYT-SSX gene fusion to confirm the SS diagnosis. Mutational analysis of exons 9, 11, 13, and 17 of c-KIT and exons 12 and 18 of PDGFRalpha was performed by direct sequencing. Immunohistochemical analysis of c-KIT, PDGFRalpha, and p-PDGFRalpha was also performed. All analyzed cases showed the presence of SYT-SSX gene fusion tran...
The EWS-ETS rearrangements, and their respective fusion gene products, are specifically associate... more The EWS-ETS rearrangements, and their respective fusion gene products, are specifically associated with histopathologically Ewing family tumors (EFT). These translocations are implicated in generating malignant transformation of EFT, but the presence of additional genetic alterations must be considered in the pathogenesis of such tumors. We analyzed 26 samples (biopsies and/or nude mice xenotransplants) collected from 19 patients with an EFT to determine whether molecular and cytogenetic alterations of the G 1 /S checkpoint genes are implicated in the pathogenesis of EFT. We found inactivating p53 mutations in three (16%) cases, which correlated with a loss of p21 WAF1/Cip1 expression and with a monosomy of chromosome 17 in two cases. Homozygous deletion of the p16 INK4A /p14 ARF gene was detected in four (21%) cases, three with codeletion of the p15 INK4B gene and with chromosome 9 abnormalities. In all of these cases, expression of the implicated genes was absent. Hypermethylation of the p16 INK4A and p15 INK4B genes was detected in two (10%) and three (16%) cases, respectively, and was correlated with a low level of gene expression. Neither cyclin D1, nor MDM2 and CDK4 amplification was observed. Kaplan-Meier analysis showed that patients with tumors carrying homozygous deletion of the 9p21 locus, or point mutations of the p53 gene, had poorer outcomes than those without these molecular alterations (p ϭ 0.005). In conclusion, 58% (11 of 19) of the analyzed patients showed genetic or epigenetic alterations in either the 9p21 locus or p53 tumor suppressor genes, defining a subgroup of patients with poor clinical outcome. This fact points to an important role of the G 1 /S cell cycle checkpoint dysregulation in the pathogenesis of EFT. (Lab Invest 2001, 81:803-814).
Arkhiv patologii
There is a growing clinical demand for analysis of the HER2/c-erbB-2 (HER2) status of breast canc... more There is a growing clinical demand for analysis of the HER2/c-erbB-2 (HER2) status of breast cancer specimens because it provides valuable prognostic, predictive and therapeutic information. In this sense, a variety of methods is available for detection of HER2 status, although to date a reliable and sensitive test does not exist. In order to choose the most suitable procedure to assess HER2 status, we analyzed 102 invasive breast cancers for HER2 overexpression by means of immunohistochemistry (IHC), with the CB11 Mo-Ab and the Hercep Test kit, and for HER2 gene amplification by fluorescence in situ hyubridization (FISH) and differential PCR (dPCR). HER2 overexpression, determined by CB11 (group C) and HercepTest (2+ and 3+), was observed in 19 samples (18.6%) whereas genetic amplification was detected in 31 (30.4%) and 14 (13.7%) cases by FISH and dPCR, respectively. The majority of overexpressed/amplified specimens corresponded to high grade tumors. We found concordances of 78-80...
Archivos españoles de urología, 2014
Identification of biomarkers that, at the time of diagnosis of prostate cancer (PCa), are associa... more Identification of biomarkers that, at the time of diagnosis of prostate cancer (PCa), are associated with presence of disease or a more aggressive behavior will transform the clinical management of this disease. If both patients and clinicians would have reproducible and valid tools to estimate the specific risk of morbidity associated with PCa, then many patients would opt to and join active surveillance (AS) protocols, and consequently costs and comorbidities associated with the current overtreatment of prostate cancer would be reduced. Thus, a biomarker, or a panel of biomarkers, with high specificity to identify patients at risk for progression in AS protocols, would identify those men who could benefit from less intensive AS protocols with less repeated biopsies, so reducing the risk and cost of these invasive procedures. In this review we try to offer an overview of the new markers identified by genomic techniques and to discuss their potential role in an AS context. Moreover,...
Seminars in Diagnostic Pathology, 2013
Dermatofibrosarcoma protuberans (DFSP) is a rare superficial tumor characterized by high rates of... more Dermatofibrosarcoma protuberans (DFSP) is a rare superficial tumor characterized by high rates of local recurrence and low risk of metastasis. DFSP occurs most commonly on the trunk and proximal extremities, affects all races, and often develops between the second and fifth decade of life. The tumor grows slowly, typically over years. Histologically, several variants of DFSP have been described and should be well characterized to avoid misdiagnosis with other tumors. These include pigmented (Bednar tumor), myxoid, myoid, granular cell, sclerotic, atrophic DFSP, giant cell fibroblastoma, and DFSP with fibrosarcomatous areas. Of all these variants, only the DFSP with fibrosarcomatous areas is high grade, with a higher rate of local recurrence and distant metastasis. DFSP is genetically characterized by the t(17;22)(q22;q13), resulting in the fusion of alpha chain type 1 of collagen gene and platelet-derived growth factor beta gene. This translocation is present in 90% of DFSP and represents a very useful tool in the differential diagnosis of DFSP with other tumors with similar histology. The standard treatment is wide local excision with at least a 2-cm margin. However, local recurrence after apparently adequate surgical excision is well recognized. Mohs micrographic surgery would be the treatment of choice with a better cure rate and maximal conservation of tissue. When surgery is insufficient, clinical evidence has suggested that imatinib mesylate is a safe and effective treatment in DFSP, especially in cases of local advanced or metastatic disease. This article presents an overview of the state of the art in the clinicopathological management of this disease.
Journal of The European Academy of Dermatology and Venereology - J EUR ACAD DERMATOL VENEREOL, 2008
International Journal of Surgical Pathology, 2011
Gastrointestinal stromal tumors (GISTs) are c-KIT-signaling-driven mesenchymal tumors of the huma... more Gastrointestinal stromal tumors (GISTs) are c-KIT-signaling-driven mesenchymal tumors of the human digestive tract, many of which have c-KIT or PDGFRα activating mutations. The authors studied the immunohistochemical markers, c-KIT and PDGFRα mutations, in GISTs and their association with the clinicopathological and clinical follow-up in 145 GISTs. Tumors were located mainly in the stomach, the median tumor size being 7.5 cm. The mitotic index was ≤5 mitoses per 50 high-power fields in 61% of cases, 96% expressed CD117, and c-KIT or PDGFRα mutations were detected in 68% of cases. The median follow-up of the series was 52 months (range = 1 to 244.9 months). Tumor size, cell morphology, mitotic index, incomplete resection, Fletcher's risk classification, Ki-67 overexpression, and c-KIT mutations were associated with progression-free survival. Incomplete resection and mitotic activity also provide information about overall survival. In conclusion, complete clinicopathological, immunohistochemical, and genetic descriptions are necessary to characterize this disease and optimize its clinical management.
Journal of the American …, 2011
Aim To review the clinical and histological data of 20 cases of dermatofibrosarcoma protuberans p... more Aim To review the clinical and histological data of 20 cases of dermatofibrosarcoma protuberans presenting at two dermatology centres in Lisbon from 1978 to 1998.
Annals of Oncology, 2010
Background: To assess whether deletions involving codons 557 and/or 558 (critical deletions) of e... more Background: To assess whether deletions involving codons 557 and/or 558 (critical deletions) of exon 11 of KIT are relevant in the prognosis of relapse-free survival (RFS) in gastrointestinal stromal tumor (GIST) patients with a long follow-up. Patients and methods: A univariate and multivariate analysis for RFS were carried out on 162 localized GIST patients over the entire follow-up period and over the intervals 0-4 years and >4 years. Factors assessed among others were Fletcher/National Institutes of Health and Miettinen-Lasota/Armed Forces Institute of Pathology (M-L/ AFIP) risk categories, critical deletions and non-deletion-type mutation (NDTM) within exon 11 of KIT.
Genes, …, 2010
Very little is known about the genetics of fibrosarcoma (FS) of bone. We applied array comparativ... more Very little is known about the genetics of fibrosarcoma (FS) of bone. We applied array comparative genomic hybridization (CGH) to identify genes and genomic regions with potential role in the pathogenesis of this tumor. Seventeen patients with FS of bone were included in the study. Array CGH analysis was carried out in 13 fresh frozen tissue specimens from 11 of these patients (nine primary tumors and four local recurrences). DNA was extracted and hybridizations were performed on Agilent 244K CGH oligoarrays. The data were analyzed using Agilent DNA Analytics Software. The number of changes per patient ranged from 0 to 132 (average ¼ 43). Losses were most commonly detected at 6q, 8p, 9p, 10, 13q, and 20p. CDKN2A was homozygously deleted in 7/11 patients. Hypermethylation of both p16 INK4a and p14 ARF was found in 1/14 patients. An internal deletion of STARD13 was found in a region with common losses at 13q13.1. The most frequent gains were seen at 1q, 4q, 5p, 8q, 12p, 15q, 16q, 17q, 20q, 22q, and Xp. Single recurrent high level amplification was detected at 4q12, including KIT, PDGFRA, and KDR. No activating mutations were found in any of them. Immunohistochemistry revealed expression of PDGFRA and/or PDGFRB in 12/17 samples. Moreover, small regions of gains pinpointed genes of particular interest, such as IGF1R at 15q26.3 and CHD1L at 1q21.1. In conclusion, our analysis provided novel findings that can be exploited when searching for markers for diagnosis and prognosis, and targets of therapy in this tumor type. in Wiley InterScience (www.interscience.wiley.com).
Diagnostic Molecular …, 2004
Advertisement. Close Window. Close Window. Thank you for choosing to subscribe to the eTOC for Di... more Advertisement. Close Window. Close Window. Thank you for choosing to subscribe to the eTOC for Diagnostic Molecular Pathology. Enter your Email address: Wolters Kluwer Health may email you for journal alerts and information ...
Laboratory …, 2003
Chondrosarcomas are malignant cartilage-forming tumors that represent the second most common mali... more Chondrosarcomas are malignant cartilage-forming tumors that represent the second most common malignant solid tumor of bone. These biologically poorly understood neoplasms vary considerably in clinical presentation and biologic behavior. Chemotherapy and radiation therapy are ...
Actas Dermo-Sifiliográficas, 2006
El dermatofibrosarcoma protuberans (DFSP) es un tumor poco frecuente, de malignidad intermedia, c... more El dermatofibrosarcoma protuberans (DFSP) es un tumor poco frecuente, de malignidad intermedia, con una baja incidencia de metástasis, pero con alta frecuencia de recurrencia local. El diagnóstico histológi-co de este tumor en ocasiones puede resultar difícil, y es necesario en estos casos realizar un estudio inmunohistoquímico para diferenciarlo de dermatofibromas atípicos y de otros sarcomas 1,2 . Sin embargo, estas técnicas no siempre son suficientes para establecer un diagnóstico adecuado. Recientemente, se han descrito en el DFSP rasgos citogenéticos específicos como la translocación recíproca t(17;22)(q22; q13) o, más a menudo, cromosomas supernumerarios en anillo derivados de la t(17;22) 3 . Como consecuencia de esta translocación, se produce una fusión génica entre el gen del colágeno tipo I␣ (COL1A1), en el cromosoma 17q, con el gen de la cadena  del factor de creci-