Expression Pattern of Alternative Splicing Variants of Human Telomerase Reverse Transcriptase (hTERT) in Cancer Cell Lines Was not Associated with the Origin of the Cells.

Telomerase and systems controlling their activity have been of great attention. There are controversies regarding the role of the alternative splicing forms of the human telomerase reverse transcriptase (hTERT), the catalytic subunit of telomerase. Therefore, the correlation between telomerase enzyme activity, the abundance of alternatively spliced variants of hTERT and doubling time of a series of cancer cell lines originated from hematopoietic, breast, colorectal, neural, ovarian, lung, kidney, bladder, prostate and head and neck cancers were investigated.

Changes in lymphocytes' telomerase activity by 4-1BB costimulation.

Aim: Lymphocytes are exceptional among somatic cells as these cells can induce telomerase enzyme after antigen stimulation to compensate chromosomal loss during rapid cell division. Activation of telomerase in lymphocytes needs CD28 signal, which simultaneously costimulates T cells during activation. 4-1BB of tumor necrosis factor superfamily also has been shown to costimulate T cells.