telomerase activity & IGF-1
excelife at earthlink.net
Mon Apr 26 05:06:37 EST 1999
In article <37229CD7.FC102979 at safarmer.com>, saf at safarmer.com says...
>This new paper may have important implications:
>Br J Haematol 1999 Mar;104(4):785-94
>Effect of insulin-like growth factor 1
>on PHA-stimulated cord blood
>mononuclear cell telomerase activity.
>Tu W, Zhang DK, Cheung PT, Tsao SW, Lau YL
>Department of Paediatrics, Faculty of Medicine, University of
>Hong Kong, Queen Mary Hospital, Pokfulam, China.
>Telomerase may contribute to the capacity for cell replication
>by compensating for the loss of telomere length. Exploring
>the use of biological modifiers in increasing cellular
>replicative potential through telomerase activity may be useful
>for in vitro expansion of haemopoietic stem cells for
>transplantation or lymphoid cells for adoptive
>immunotherapy. In this study we showed for the first time
>that insulin-like growth factor 1 (IGF-1) modulated
>telomerase activity in human cord blood mononuclear cells
>(MNC) and some of the known functional determinants of
>telomerase activity. We found that cord blood MNC
>expressed constitutively a low level of telomerase activity and
>human telomerase reverse transcriptase (hTRT) mRNA, and a
>high level of human telomerase RNA component (hTR) and
>telomerase-associated protein-1 (TP1) mRNA. Interestingly,
>IGF-I alone did not increase the telomerase activity of cord
>blood MNC but could enhance the PHA-induced increase in
>telomerase activity[PHA = phytohemagglutinin = a lectin isolated
>from the red kidney bean that induces cell division]. These
>alterations in telomerase activity were not completely in phase
>with those of proliferation response. On the other hand, IGF-I
>did not alter hTRT mRNA expression but enhanced the PHA-induced
>increase in hTRT whereas TP1 mRNA expression was stimulated by
>either IGF-I or PHA but showed no additive increase when
>stimulated by both IGF-1 and PHA. Neither IGF-1 nor PHA
>altered hTR expression. Finally, the temporal dynamics of
>hTRT mRNA expression and telomerase activity in cord
>blood MNC over 5 d in culture were not totally concordant.
>suggesting that key factors other than hTRT were involved in
>regulating telomerase activity in cord blood MNC. The
>modulatory effect of IGF-1 on telomerase activity supports its
>potential role in increasing replicative potential of cord blood
>lymphoid cells or haemopoietic stem cells.
>PMID: 10192441, UI: 99206659
Thank you for posting this abstract! Your comments do reflect a flair for
This confirms research being funded by Lifeline Laboratories that the
combination of a number of growth factors, (including IGF-1), and the enzyme
telomerase are beneficial for the long term maintenance and replication of
haemopoietic stem cells.
The implications for bone marrow transplants may be dramatic. This
technology just may allow us to grow these cells in a relatively short time
frame and in sufficient quantity to allow a patients own cells to be used for
I am a little disappointed that someone beat our funded Researchers to
publication of these results but our research is a little more ambitious than
the research cited above. It includes some additional growth factors and
other bio-chemicals to determine appropriate levels of each to achieve
optimum results. Final results are still quite a way off and Publication
That the above abstract confirms some of our preliminary results is a good
indication that the research is headed in the right direction!
Thomas Mahoney, Pres.
Lifeline Laboratories, Inc.
More information about the Ageing