Telomerase activity and telomere elongation are essential conditions for the unlimited proliferation of neoplastic cells. Point mutations in the core promoter region of the telomerase reverse transcriptase (TERT) gene have been found to occur at high frequencies in several tumour types and considered a primary cause of telomerase reactivation in cancer cells. These mutations promote TERT gene expression by multiple mechanisms, including the generation of novel binding sites for nuclear transcription factors, displacement of negative regulators from DNA G-quadruplexes, recruitment of epigenetic activators and disruption of long-range interactions between TERT locus and telomeres.
View Article and Find Full Text PDFUMG1 is a unique epitope of CD43, not expressed by normal cells and tissues of haematopoietic and non-haematopoietic origin, except thymocytes and a minority (<5%) of peripheral blood T lymphocytes. By immunohistochemistry analysis of tissue microarray and pathology slides, we found high UMG1 expression in 20%-24% of diffuse large B-cell lymphomas (DLBCLs), including highly aggressive BCL2 and CD20 cases. UMG1 membrane expression was also found in DLBCL bone marrow-infiltrating cells and established cell lines.
View Article and Find Full Text PDFHuman oncoviruses are able to subvert telomerase function in cancer cells through multiple strategies. The activity of the catalytic subunit of telomerase (TERT) is universally enhanced in virus-related cancers. Viral oncoproteins, such as high-risk human papillomavirus (HPV) E6, Epstein-Barr virus (EBV) LMP1, Kaposi's sarcoma-associated herpesvirus (HHV-8) LANA, hepatitis B virus (HBV) HBVx, hepatitis C virus (HCV) core protein and human T-cell leukemia virus-1 (HTLV-1) Tax protein, interact with regulatory elements in the infected cells and contribute to the transcriptional activation of TERT gene.
View Article and Find Full Text PDFT-cell acute lymphoblastic leukemia (T-ALL) is an aggressive malignancy burdened by poor prognosis. While huge progress of immunotherapy has recently improved the outcome of B-cell malignancies, the lack of tumor-restricted T-cell antigens still hampers its progress in T-ALL. Therefore, innovative immunotherapeutic agents are eagerly awaited.
View Article and Find Full Text PDFCircular RNAs (circRNAs) are a new class of "non-coding RNAs" that originate from non-sequential back-splicing of exons and/or introns of precursor messenger RNAs (pre-mRNAs). These molecules are generally produced at low levels in a cell-type-specific manner in mammalian tissues, but due to their circular conformation they are unaffected by the cell mRNA decay machinery. circRNAs can sponge multiple microRNAs or RNA-binding proteins and play a crucial role in the regulation of gene expression and protein translation.
View Article and Find Full Text PDFGastric cancer (GC) is a complex disease linked to a series of environmental factors and unhealthy lifestyle habits, and especially to genetic alterations. GC represents the second leading cause of cancer-related deaths worldwide. Its onset is subtle, and the majority of patients are diagnosed once the cancer is already advanced.
View Article and Find Full Text PDFA 24-amino acid leader peptide of a new human recombinant manganese superoxide dismutase can enter cells and carry molecules. Here, we demonstrated that six of the 24 amino acids penetrate cells through a particular gate represented by a specific amino acid sequence of the oestrogen receptor (ER). We analysed the internalization of the synthetic hexapeptide and the cytotoxic activity of the hexapeptide conjugated to cisplatin on a cell line panel.
View Article and Find Full Text PDFImmune activation and chronic inflammation are hallmark features of HIV infection causing T-cell depletion and cellular immune dysfunction in AIDS. Here, we addressed the issue whether HIV-1 Tat could affect T cell development and acute inflammatory response by generating a transgenic mouse expressing Tat in lymphoid tissue. Tat-Tg mice showed thymus atrophy and the maturation block from DN4 to DP thymic subpopulations, resulting in CD4(+) and CD8(+) T cells depletion in peripheral blood.
View Article and Find Full Text PDFGlycosylation is a posttranslational modification of proteins playing a major role in cell signalling, immune recognition, and cell-cell interaction because of their glycan branches conferring structure variability and binding specificity to lectin ligands. Aberrant expression of glycan structures as well as occurrence of truncated structures, precursors, or novel structures of glycan may affect ligand-receptor interactions and thus interfere with regulation of cell adhesion, migration, and proliferation. Indeed, aberrant glycosylation represents a hallmark of cancer, reflecting cancer-specific changes in glycan biosynthesis pathways such as the altered expression of glycosyltransferases and glycosidases.
View Article and Find Full Text PDFThe regulation of cell growth and division occurs in an accurate sequential manner. It is dictated by the accumulation of cyclins (CCNs) and cyclin-dependent kinases (CDKs) complexes and degradation of CCNs. In human tumors, instead, the cell cycle is deregulated, causing absence of differentiation and aberrant cell growth.
View Article and Find Full Text PDFReactive oxygen species (ROS) are generated as a consequence of metabolic reactions in the mitochondria of eukaryotic cells. This work describes the role of the manganese superoxide dismutase (MnSOD) as a biomarker of different human diseases and proposes a new therapeutic application for the prevention of cancer and its treatment. The paper also describes how a new form of human MnSOD was discovered, its initial application, and its clinical potentials.
View Article and Find Full Text PDFCD43 is a sialoglycosylated membrane protein that is involved in cell proliferation and differentiation. CD43 glycoforms that are recognized by the UN1 monoclonal antibody (mAb) were expressed in lymphoblastoid T-cell lines and solid tumors, such as breast, colon, gastric, and squamous cell lung carcinomas, while unexpressed in the normal counterparts. The cancer association of UN1/CD43 epitope suggested the possibility to use the UN1 mAb for tumor diagnosis and therapy.
View Article and Find Full Text PDFThe UN1 monoclonal antibody recognized the UN1 antigen as a heavily sialylated and O-glycosylated protein with the apparent molecular weight of 100-120 kDa; this antigen was peculiarly expressed in fetal tissues and several cancer tissues, including leukemic T cells, breast, and colon carcinomas. However, the lack of primary structure information has limited further investigation on the role of the UN1 antigen in neoplastic transformation. In this study, we have identified the UN1 antigen as CD43, a transmembrane sialoglycoprotein involved in cell adhesion, differentiation, and apoptosis.
View Article and Find Full Text PDFB-cell lymphoma is a clonal expansion of neoplastic cells that may result in fatal outcomes. Here, we report the in vivo targeting and growth inhibition of aggressive A20 murine B-cell lymphoma by idiotype-specific peptide pA20-36. pA20-36 was selected from random peptide libraries and bound specifically to the B-cell receptor (BCR) of A20 cells in mice engrafted with A20 lymphoma, as shown by histology and positron emission tomographic analysis.
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