Telomerase reverse transcriptase (TERT) is a catalytic subunit of telomerase. Telomerase complex plays a key role in cancer formation by telomere dependent or independent mechanisms. Telomere maintenance mechanisms include complex TERT changes such as gene amplifications, TERT structural variants, TERT promoter germline and somatic mutations, TERT epigenetic changes, and alternative lengthening of telomere. All of them are cancer specific at tissue histotype and at single cell level. TERT expression is regulated in tumors via multiple genetic and epigenetic alterations which affect telomerase activity. Telomerase activity via TERT expression has an impact on telomere length and can be a useful marker in diagnosis and prognosis of various cancers and a new therapy approach. In this review we want to highlight the main roles of TERT in different mechanisms of cancer development and regulation.

At the beginning of 21(st) century, fifty years after discovery of deoxyribonucleic acid (DNA) double helix structure, scientific world is faced with a great progress in many disciplines of biological research, especially in the field of molecular biology and operating on nucleid acid molecules. Many molecular biology techniques have been implemented successfully in biology, biotechnology, medical science, diagnostics, and many more. The introduction of polymerase chain reaction (PCR) resulted in improving old and designing new laboratory devices for PCR amplification and analysis of amplified DNA fragments. In parallel to these efforts, the nature of DNA molecules and their construction have attracted many researchers. In addition, some studies concerning mimicking living systems, as well as developing and constructing artificial nanodevices, such as biomolecular sensors and artificial cells, have been conducted. This review is focused on the potential of nanotechnology in health care and medicine, including the development of nanoparticles for diagnostic and screening purposes, the manufacture of unique drug delivery systems, antisense and gene therapy applications and the enablement of tissue engineering, including the future of nanorobot construction.

HLA-E belongs to the non-classical HLA (class Ib family) broadly defined by a limited polymorphism and a restricted pattern of cellular expression. So far, only two functional alleles differing at only one amino acid position (non-synonymous mutation) in the α2 heavy chain domain, where an arginine in position 107 in HLA-E*0101 is replaced by a glycine in HLA-E*0103, have been reported. The interaction between non-classical HLA-E molecule and CD94/NKG2A receptor plays a crucial role in the immunological response involving natural killer (NK) cells and cytotoxic T lymphocytes. All proteins forming CD94/NKG2 receptors are encoded by genes situated in the same cluster on chromosome 12, allowing tight control over the order of their expression. The inhibitory members of the NKG2 receptor family are available on the cell surface before activating the members to prevent autoimmune incidents during immune cells' ontogenesis. In the present review, the potential role of this interaction in viral infection, pregnancy and transplantation of allogeneic hematopoietic stem cells (HSC) is presented and discussed. The review will also include the effect of HLA-E polymorphism on the outcome of HSC transplants in humans.