Search results for "Cause"
showing 10 items of 6525 documents
Mitochondrial D310 mutations in colorectal adenomas: an early but not causative genetic event during colorectal carcinogenesis.
2008
Somatic mutations of the D310 sequence of the mitochondrial DNA are reported in human cancers, including colorectal cancers (CRC). The presence of these mutations at early or late steps of colorectal carcinogenesis is unknown. Their prevalence increased significantly with the number of cytosines in the D310 sequence of the matched normal tissue (D310 polymorphism), suggesting that this polymorphism could be a risk factor for CRC. The aim of this study was (i) to investigate the prevalence of D310 mutations in 64 colorectal adenomas and 36 liver metastases from 15 CRC patients, (ii) to assess the relation between D310 polymorphism and the risk of colorectal adenoma in a case-control study in…
Gastric adenomas: relationship between clinicopathological findings, Helicobacter pylori infection, APC mutations and COX-2 expression.
2006
Gastric adenomas are rare neoplastic growths characterized by localized polypoid proliferations of dysplastic epithelium that tend to progress to infiltrating adenocarcinoma. Therefore, the identification of molecular markers that could reliably recognize adenomas at risk of progression is advocated in the clinical management. In this study we investigated, in a series of gastric adenoma specimens from an area at high risk of gastric cancer, the relationship between clinicopathological characteristics of adenoma and Helicobacter pylori infection, APC mutational status, and COX-2 and the down-stream enzyme mPGES1 expression. Helicobacter pylori infection, detected in 24%, and 33% by histolog…
Colonoscopy and reduction of colorectal cancer risk by molecular tumor subtypes: a population-based case-control study
2020
AbstractObjectiveIn previous studies, the protective effect of colonoscopy was generally stronger for distal than for proximal colorectal cancer (CRC). This study aimed to investigate whether the association of colonoscopy and CRC risk varies according to major molecular pathological features and pathways of CRC.DesignPopulation-based case-control study from Germany, including 2132 patients with a first diagnosis of CRC and information on major molecular tumor markers, and 2486 control participants without CRC. Detailed participant characteristics were collected by standardized questionnaires and information on previous colonoscopy was derived from medical records. Polytomous logistic regre…
Novel mutations of the MET proto-oncogene in papillary renal carcinomas.
1999
Hereditary papillary renal carcinoma (HPRC) is characterized by multiple, bilateral papillary renal carcinomas. Previously, we demonstrated missense mutations in the tyrosine kinase domain of the MET proto-oncogene in HPRC and a subset of sporadic papillary renal carcinomas. In this study, we screened a large panel of sporadic papillary renal carcinomas and various solid tumors for mutations in the MET proto-oncogene. Summarizing these and previous results, mutations of the MET proto-oncogene were detected in 17/129 sporadic papillary renal carcinomas but not in other solid tumors. We detected five novel missense mutations; three of five mutations were located in the ATP-binding region of t…
Ten kilodalton heat shock protein (HSP10) is overexpressed during carcinogenesis of large bowel and uterine exocervix
2003
In the present study, we evaluated the presence and the level of expression of HSP10 in two carcinogenetic models: the 'adenoma-carcinoma sequence' of large bowel and the 'dysplasia-carcinoma sequence' of uterine exocervix. We found HSP10 was overexpressed during the carcinogenesis of both organs. In particular, HSP10 was overexpressed early in large bowel carcinogenesis, while the expression of this protein in exocervical carcinogenesis gradually increased from normal through dysplastic to neoplastic tissues. The quantitative analysis of immunohistochemistry and the Western blotting confirmed these results. Our previous observations showed overexpression of HSP60 in the same carcinogenetic…
STEM CELLS AND COLON CANCER
2012
The current concept of tumorigenesis suggests that cancers arise and are “driven” by cells with stem cell-like properties, known as cancer stem cells (CSCs), which share many functional and molecular features with normal stem cells. Self-renewal key pathways (e.g., Wnt, Notch, and Hedgehog) are tightly regulated in normal stem cells, but are impaired in CSCs. For instance, active Wnt pathway plays a crucial role in colon cancer pathophysiology, where deregulation of the adenomatous polyposis coli (APC) gene, a negative regulator of Wnt signaling, represents one of the earliest alterations in the multistep process of colon carcinogenesis, causing early adenoma formation. Normal colon stem ce…
Phenotype determining alleles in GM1 gangliosidosis patients bearing novel GLB1 mutations.
2010
Hofer D, Paul K, Fantur K, Beck M, Roubergue A, Vellodi A, Poorthuis BJ, Michelakakis H, Plecko B, Paschke E. Phenotype determining alleles in GM1 gangliosidosis patients bearing novel GLB1 mutations. GM1 gangliosidosis manifests with progressive psychomotor deterioration and dysostosis of infantile, juvenile, or adult onset, caused by alterations in the structural gene coding for lysosomal acid s-galactosidase (GLB1). In addition, allelic variants of this gene can result in Morquio B disease (MBD), a phenotype with dysostosis multiplex and entire lack of neurologic involvement. More than 100 sequence alterations in the GLB1 gene have been identified so far, but only few could be proven to …
Use of the polymerase chain reaction to demonstrate hepatitis B virus DNA in serum of children with chronic hepatitis B.
1992
The polymerase chain reaction was used to investigate the presence of hepatitis B virus DNA in sera of 61 children with chronic hepatitis B and negative results on dot biot hybridization tests. Our results demonstrate that most chronic carriers of hepatitis B surface antigen in childhood have hepatitis B virus DNA detectable by polymerase chain reaction in their serum and must be considered infectious.
Controversies on the role of Th17 in cancer: a TGF-β-dependent immunosuppressive activity?
2012
The immune system has important roles in limiting the spread of cancer and shaping the tumor microenvironment. Although the contributions of T helper 17 (Th17) cells (a subtype of CD4(+) T lymphocytes) to autoimmunity and allergy response are well known, their roles in cancer remain ambiguous. Despite adoptive transfer studies indicating that mouse Th17 cells support anticancer immunity, the Th17 cells that naturally infiltrate experimental tumors appear to have a tumor-promoting effect. These contradictory properties can be related to the high degree of plasticity inherent in Th17 cells and their capacity to differentiate into tumoricidal Th1-like cells. Mouse Th17 cells induced by transfo…
Research in practice: Regulatory T cells - targets for therapeutic approaches?
2010
• regulatory T cells • tolerance • signal transduction • autoimmunity • allergies • cancer Summary Regulatory T cells (Tregs) are essential for induction and maintenance of immunological tolerance. They contribute to prevention of autoimmunity by control and modulation of immune responses. The prevalence of autoimmune diseases, chronic infections, cancer and allergies has markedly increased in the last decades. In additions the treatment of these disorders is often unsatisfactory so that improvements are needed. This has stimulated intensive research in the biology of Tregs. Recent studies revealed that naturally occurring CD4 + CD25 + Tregs (nTregs) and induced Tregs (iTregs) are critical …