Comments on: It is actually not like we thought before - ISSCR 2008 annual meeting report

By: Alex

Alex — Sun, 09 Nov 2008 04:46:55 +0000

to Kenny -
look at this paper - Reprogramming of a melanoma genome by nuclear transplantation

By: Kenny

Kenny — Sat, 08 Nov 2008 10:23:00 +0000

Does anyone know about experiments to potentially “reprogram” a cancer cell either by putting in the key transcription factors(iPS) or nuclear transfer into ES? I just wonder how epigenetic status in the first place could predispose the DNA to mutation to begin with, but if the epigenetic state could be reset. Basically I am just wondering if a nucleus from a cancer cell could be reprogrammed to a pluripotent state…would it produce a variety of different cancers?

By: Alex

Alex — Mon, 30 Jun 2008 02:40:28 +0000

to Alex De Los Angeles -

Poster title: Pluripotent stem cell induced from adult neural stem cells by reprogramming with 2 factors.
Kim Jeong Beom et al… Scholer Hans (lab); Germany

Oct4 and klf4 are sufficient to generate iPS cells from mouse neural stem cell without drug selection.

Conclusion: in inducing pluripotency, the number of reprogramming factors can be reduced when using somatic cells that endogenously express appropriate levels of complementing factors.

By: JWS

JWS — Fri, 27 Jun 2008 19:06:53 +0000

I think Jaenisch group did bone marrow transplantation with iPS cells in mouse to correct a gene defect of sickle cell anemia. I don’t think they reported long-term survival of mice, however, or looked at in terms of epigenetic signatures. Maybe DNA methylase inhibitor or more specifically, knockout mice of methylase enzymes (that are not lethal such as MBD2) can be used as a proof of principle to see if iPS cell-derived embryos survive better.

By: Oracy

Oracy — Mon, 23 Jun 2008 05:44:55 +0000

The fact that the iPS cells don’t form viable animals with high efficiency shouldn’t really be a surprise . . . I mean, the complete resetting of the genome is daunting task. One obvious possibility is incomplete reprogramming of methylated chromatin, especially within imprinted regions vital for embryo survival. Perhaps, there should be a later stage readout of differentiation potential, like the reconstitution of adult bone marrow after a tranplantation of chimeric fetal liver cells or something like that, like these guys did: Genes Dev. 2007 Feb 15;21(4):409-19.

By: Alex De Los Angeles

Alex De Los Angeles — Sun, 22 Jun 2008 07:26:13 +0000

Hi,

I was wondering, you mentioned that someone had a poster that claimed generating iPS by two factors — which factors were they? Do you remember which lab the poster came from?

All the best,

Alex