ONT ny, THE MOUNT SINAI MEDICAL CENTER

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MEM ONE GUSTAVE L. LEVY PLACE « NEW YORK, NY 10029-6574

 

OF THE CITY UNIVERSITY
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Mount Sinai School of Medicine * The Mount Sinai Hospital

The Lillian and Henry M. Stratton-Hans Popper (212) 241-8014
Department of Pathology

Box 1194
October 17, 1993 pw...

US EERET 2 0

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Dr. Joshua Lederberg

The Rockefeller University ow. oe
New York, NY 10021 f on
i OCT 2 5 19935

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Dear Dr. Lederberg,

 

Thank you for calling my attention to the paper by T.G.
Dunahay on transformation of Chlamydomonas using silicon carbide
whiskers. I am sending you a reprint of our 1993 paper on asbestos-
mediated transfection of mesothelial cells. These cells appear to
be exquisitely sensitive to both transfecting and cytotoxic effects
of asbestos fibers. All types of asbestos fibers can mediate
transfection. Please also check out the 1991 paper by George Dubes,
referenced in our paper. He essentially confirms our earlier
results but uses much higher doses of asbestos fibers to transfect,
doses which would be toxic to the mesothelial cells.

Most of our work over the last year has been on pura, a new
protein we have discovered which be believe plays a role in control
of initiation of DNA replication in mammalian cells. I am sending
you 2 reprints of our recent papers on this protein. The most
exciting work is yet to be published.We have found that pura binds
to the retinoblastoma protein, Rb, which is the product of a tumor
suppressor gene. We have now identified the region of pura that
binds to Rb, and the part of the gene encoding this region is
mutated in 4 of 13 mesotheliomas but not in normal tissue from the
same patients. We are now beginning to look in lung, breast and
colon tumors. I shall keep you apprised.

Thank you again, and best wishes.

Fou bes Sincerely,
Env. Rao “> L
17f-YL Edward M. Johnson, Ph.D.
62:8 ¥ Professor

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