350 research outputs found
Update on colorectal carcinomatosis - from molecular biology to diagnosis and management
After liver metastases, Peritoneal Carcinomatosis (PC) is the second most frequent cause of death in patients with Co-lorectal Cancer (CRC), although the precise incidence of Colorectal Cancer Peritoneal Carcinomatosis is not known, as the majority of the diagnostic studies cannot detect the disease in its initial stages, nowadays, the diagnosis of peritoneal carcinomatosis remains a challenge. The molecular biology of PC is only just beginning to be understood, future knowledge will permit not only identify novel strategies for PC prevention, but also contribute to therapeutic advances, through the development of molecular targeted therapies. The authors performed a literature revision about the Molecu-lar Biology, Diagnosis and Management of Colorectal Cancer Peritoneal carcinomatosis
Clinicopathological correlation and prognostic significance of VEGF-A, VEGF-C, VEGFR-2 and VEGFR-3 expression in colorectal cancer
BACKGROUND: Colorectal cancer (CRC) is the third most common type of cancer and the fourth most frequent cause of cancer death. Literature indicates that vascular endothelial growth factor is a predominant angiogenic factor and that angiogenesis plays an important role in the progression of CRC.
PATIENTS AND METHODS: The present series consisted of tissue samples obtained from 672 patients who had undergone large bowel resection between 2005 and 2010 at the Braga Hospital, Portugal. Archival paraffin-embedded CRC tissue and normal adjacent samples were used to build up tissue microarray blocks and VEGF-A, VEGF-C, VEGFR-2 and VEGFR-3 expression was immunohistochemically assessed.
RESULTS: We observed an overexpression of VEGF-C in CRC when tumour cells and normal-adjacent tissue were compared (p=0.004). In tumour samples, VEGF-C-positive cases were associated with VEGFR-3 expression (p=0.047). When assessing the correlation between VEGF-A, VEGF-C, VEGFR-2 and VEGFR-3 expressions and the clinicopathological data, it was revealed that VEGF-A positive cases were associated with male gender (p=0.016) and well-differentiated tumours (p=0.001); VEGF-C with colon cancers (p=0.037), exophytic (p=0.048), moderately-differentiated (p=0.007) and T3/T4 (p=0.010) tumours; VEGFR-2 with invasive adenocarcinoma (p=0.007) and VEGFR-3 with the presence of hepatic metastasis (p=0.032). Overall survival curves for CRC were statistically significant for rectal cancer, VEGF-C expression and stage III (p=0.019) and VEGFR-3 expression and stage IV (p=0.047).
CONCLUSION: Quantification of VEGF-A, VEGF-C, VEGFR-2 and VEGFR-3 expression seems to provide valuable prognostic information in CRC and the correlation with clinicopathological data revealed an association with characteristics that contribute to progression, invasion and metastasis leading to poorer survival rates and prognosis
Predictive biomarkers in colorectal cancer: from the single therapeutic target to a plethora of options
Colorectal cancer (CRC) is one of the most frequent cancers and is a leading cause of cancer death worldwide. Treatments used for CRC may include some combination of surgery, radiation therapy, chemotherapy, and targeted therapy. The current standard drugs used in chemotherapy are 5-fluorouracil and leucovorin in combination with irinotecan and/or oxaliplatin. Most recently, biologic agents have been proven to have therapeutic benefits in metastatic CRC alone or in association with standard chemotherapy. However, patients present different treatment responses, in terms of efficacy and toxicity; therefore, it is important to identify biological markers that can predict the response to therapy and help select patients that would benefit from specific regimens. In this paper, authors review CRC genetic markers that could be useful in predicting the sensitivity/resistance to chemotherapy.info:eu-repo/semantics/publishedVersio
Angiogênese, homeostasia e câncer: novos paradigmas e velhos problemas
Neovascularization is a crucial phenomenon for the continuous growing of neoplastic cells and cancer progression. The growth of new blood vessels from pre-existing vessels (angiogenesis) occurs in several physiological and pathological conditions, including cancer, where it is critical for tumor-cells nutrition. Recently, new remarkable insights regarding angiogenesis and blood coagulation (key events in vascular biology) have been described. The serine protease thrombin, which plays a central role in blood coagulation cascade through its ability to cleave fibrinogen conducting to fibrin clot formation, is also known to be involved in embryogenesis, inflammation, wound healing, through its active role on vascular remodeling. Although the increased knowledge of factors regulating angiogenesis and coagulation led to the understanding that angiogenesis, homeostasis and carcinogenesis are three close team players, little is still known about how these pathways support each other in the process of angiogenesis in vivo. This review summarizes current understanding of blood coagulation cascade role in conducting angiogenesis and tumor progression, as well as provides an overview of the emerging anti-angiogenic and anti-coagulation therapies inducing tumor regression.A neovascularização é um processo fundamental para a sobrevivência e a progressão das células neoplásicas malignas. O crescimento de novos vasos sanguíneos a partir de vasos já existentes, fenômeno designado como angiogênese, está envolvido em vários processos fisiológicos e patológicos, incluindo o crescimento tumoral, onde a angiogênese desempenha papel crítico na nutrição das células tumorais. Tal como a angiogênese, o sistema de coagulação sanguínea exerce importante função na biologia vascular. A trombina, uma serina protease, tem papel fundamental na cascata de coagulação, pela quebra enzimática do fibrinogênio e pela conseqüente produção de fibrina. Essa protease encontra-se também implicada em desenvolvimento embrionário, inflamação e cicatrização, processos nos quais a remodelação vascular está altamente ativa. Apesar de o crescente conhecimento de fatores reguladores da angiogênese e da coagulação demonstrar que a carcinogênese, a coagulação e a angiogênese são três close team players, ainda muito pouco se sabe sobre o modo como esses players comunicam-se e interagem no processo de angiogênese in vivo. Esta revisão sumariza os conhecimentos atuais quanto ao papel da cascata de coagulação na condução do processo angiogênico e do crescimento tumoral, bem como oferece uma visão geral sobre recentes terapias antiangiogênicas e anticoagulantes envolvidas na regressão tumoral.(undefined
Papillomavirus from the bench to the clinics
[Excerpt] Human papillomavirus (HPV) represents an exciting subject of study because it is currently established as an essential etiological factor of uterine cervical cancer and strongly implicated in the development of other genital cancers as well, in addition to benign genital warts. Additionally, substantial amount of new data have been elaborated linking HPV with head and neck cancer and, more tentatively, also with esophageal, breast, prostate, and lung cancers. Despite the existing controversies, the possible link of HPV infection with these nongenital carcinomas opens a new fascinating era of HPV research. [...
Angiogenesis, Lymphangiogenesis and Lymphovascular Invasion: Prognostic Impact for Bladder Cancer Patients
Lymphangiogenesis: from the pig embryos to cancer
The discovery and the comprehension of lymphatic vessels suffered several historical delays and setbacks. The inherent anatomical problems slowed down the precise identification of the lymphatic system during the development of medical science. Gasparo Aselli, an Italian surgeon and anatomist, was the first to describe the lymphatic vessels in 1627 (De Lacteibus sive Lacteis Venis). However, most original descriptions that report the morphology of the lymphatic system in different organisms were done during the 19th and the 20th centuries. The recent identification of specific lymphatic vasculature molecular markers allows a more accurate identification and characterization of the lymphatic system evolution in different organs, as well as its role in different pathological conditions, including cancer.
This study summarizes the current understanding of lymphangiogenesis in tumour progression, as well as it presents a review of the promising data regarding the prognostic value of lymphatic density and
the use of therapeutic lymphangiogenic molecules.A descoberta dos vasos linfáticos e sua compreensão enfrentaram uma série de atrasos e dificuldades históricos. As inerentes dificuldades anatômicas retardaram a identificação precisa da rede vascular
linfática durante o desenvolvimento da ciência médica. Gasparo Aselli, um anatomista e cirurgião italiano, foi o primeiro a descrever os vasos linfáticos, em 1627 (De Lacteibus sive Lacteis Venis). Entretanto, a maioria das descrições originais que relatam a morfologia do sistema linfático nos diferentes organismos
foi realizada depois, entre os séculos XIX e XX. A recente identificação de marcadores moleculares específicos à vasculatura linfática permite agora identificação e caracterização mais acuradas da evolução
da rede linfática nos vários órgãos e em diferentes situações, inclusive no câncer. Esta revisão resume o conhecimento sobre a linfangiogênese na progressão tumoral, bem como apresenta uma síntese dos dados mais promissores em relação ao valor prognóstico da densidade linfática e da utilização das
moléculas linfangiogênicas como alvo terapêutico.(undefined
Gastric Cancer and Angiogenesis: Is VEGF a Useful Biomarker to Assess Progression and Remission?
Gastric cancer (GC) has high mortality owing to its aggressive nature. Tumor angiogenesis plays an essential role in the growth, invasion, and metastatic spread of GC. The aim of this work was to review the angiogenic biomarkers related to the behavior of GC, documented in the literature. A search of the PubMed database was conducted with the MeSH terms: "Stomach neoplasms/blood [MeSH] or stomach neoplasms/blood supply [MeSH] and angiogenic proteins/blood [Major]". A total of 30 articles were initially collected, and 4 were subsequently excluded. Among the 26 articles collected, 16 examined the role of vascular endothelial growth factor (VEGF), 4 studied endostatin, 3 investigated angiopoietin (Ang)-2, 2 studied the Ang-like protein 2 (ANGTPL2), and 1 each examined interleukin (IL)-12, IL-8, and hypoxia inducible factor. Regarding VEGF, 6 articles concluded that the protein was related to lymph node metastasis or distant metastases. Five articles concluded that VEGF levels were elevated in the presence of GC and decreased following tumor regression, suggesting that VEGF levels could be a predictor of recurrence. Four articles concluded that high VEGF levels were correlated with poor prognosis and lower survival rates. Ang-2 and ANGTPL2 were elevated in GC and associated with more aggressive disease. Endostatin was associated with intestinal GC. VEGF is the most extensively studied angiogenic factor. It is associated with the presence of neoplastic disease and lymph node metastasis. It appears to be a good biomarker for disease progression and remission, but not for diagnosis. The data regarding other biomarkers are inconclusive.info:eu-repo/semantics/publishedVersio
Gastric cancer treated with pressurized intraperitoneal aerosol chemotherapy: revising an option for peritoneal carcinomatosis
Aim: Gastric cancer is the cancer with the highest rate of peritoneal metastization and this type of spread is associated with a higher death rate compared to distant organ metastasis. The systemic chemotherapy has a minimal effect in peritoneal metastasis so new types of treatment have emerged. The authors revised the main studies done in pressurized intraperitoneal aerosol chemotherapy (PIPAC) and presented the main conclusions.
Methods: A PubMed search was conducted focusing on PIPAC in gastric cancer. The MeSH database was searched with the terms: “Gastric cancer [MeSH] and intraperitoneal aerosol chemotherapy”.
Results: Seven studies were analyzed. All the studies performed the technique with aerosol of doxorubicin and cisplatin. All cases were well tolerated, with minor adverse effects. Patients presented resolution of their abdominal symptoms and regression of macroscopic carcinomatosis. Cytoreductive surgery or hypertermic intraperitoneal chemotherapy could be performed in some patients with good response to PIPAC. The peritonitis caused by the chemotherapy was well tolerated.
Conclusion: PIPAC can induce remission in end-stage and resistant disease with acceptable side effects, good safety levels for patients and health professionals, and quality of life improvement.info:eu-repo/semantics/publishedVersio
Methodology for single nucleotide polymorphism selection in promoter regions for clinical use. An example of its applicability
Genetic variability in humans can explain many differences in disease risk factors. Polymorphism-related studies focus mainly on the single nucleotide polymorphisms (SNPs) of coding regions of the genes. SNPs on DNA binding motifs of the promoter region have been less explored. On a recent study of SNPs in patients with non-Hodgkin lymphomas we faced the problem of SNP selection from promoter regions and developed a practical methodology for clinical studies. The process consists in identifying SNPs in the coding and promoter regions of the antigen-processing system using the 'dbSNP' database. With the 'HapMap' program, we select SNPs with frequencies >20% in Caucasian populations. For coding regions, we sought biologically and clinically relevant SNPs described in the literature. For the promoter regions, we determined their chromosomal location on 'QiagenSABioscience' site database. The nucleotide sequence of ancestral and variant alleles is available in the 'dbSNP'. These sequences were used in ` Promoter TESS' to determine binding differences of transcription factors. Each sequence may have affinity to different TFs. Thus, SNP selection on the promoter regions was based in the differences on TF binding pattern between the old and the new allele. The potential clinical relevance of the new TFs was also evaluated before the final selection. With this approach, we found that almost half of the relevant SNP fall within the promoter region. In conclusion, we were able to develop a methodology of oriented selection of promoter regions of human genes, comparing the TF with affinity to the ancestral allele with the TF to a variant allele. We selected those SNPs that change the TF's affinity to a pattern with functional significance.(undefined)info:eu-repo/semantics/publishedVersio
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