Retroviruses can only replicate in replicating cells

G

Gerwyn

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take home message XMRV will not replicate in non replicating blood cells.guess what type of blood cells the European studies used for their PCR runs?





Retroviruses as Carcinogens and Pathogens:
Expectations and Reality
By Peter H. Duesberg

Cancer Research, Vol. 47, pp. 1199-1220,
(Perspectives in Cancer Research), March 1, 1987.


The vast majority of the tumor viruses are retroviruses and DNA viruses that do not contain oncgenes. The RNA genomes of all retroviruses without oncgenes measure only 8 to 9 kilobases (13, 22). They all encode three major essential genes which virtually exhaust their coding capacity. These are in the 5' to 3' map order gag which encodes the viral core protein, pol which encodes the reverse transcriptase, and env which encodes the envelope glycoprotein (23, 24). Although these viruses lack oncgenes they are considered tumor viruses, because they were originally isolated from tumors and because experimental infections may induce tumors under certain conditions. However, in contrast to tumors caused by viruses with oncgenes, such tumors are always monoclonal and induced reproducibly only in genetically selected animals inoculated as newborns after latent periods of over 6 months (see below). Because of the long latent periods, these retroviruses are said to be "slow" viruses (13, 16), although their mechanism of replication is exactly the same as that of their fast and efficient relatives with oncgenes that transform cells as soon as they infect them (5, 19) (Table 1). The retroviruses are also considered to be plausible natural carcinogens because they are not cytocidal and hence compatible with neoplastic growth and other slow diseases. Indeed, retroviruses are the only viruses that depend on mitosis for replication (13, 25).

# Weiss, R., Teich, N., Varmus, H., and Coffin, J. RNA Tumor Viruses. Ed. 2. Cold Spring Harbor, NY: Cold Spring Harbor Press, 1985.

Rubin, H., and Temin, H.M. A radiological study of cell-virus interaction in the Rous sarcoma. Virology, 7: 75-91, 1958.
 

JT1024

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Good catch Gerwyn...

Noticed the date of the publication is 1985. Is this so fundamental that a textbook might contain the same information or has something changed?
 
G

Gerwyn

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Good catch Gerwyn...

Noticed the date of the publication is 1985. Is this so fundamental that a textbook might contain the same information or has something changed?
unless retroviruses have changed no.it is in virtually everytextbook.that is why i was so cross that Dr vernon didn,t focus on the fact.Combine old blood and low titre and you would probably have as much chance of finding XMRV with a fishing rod!
 

citybug

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The vast majority of the tumor viruses are retroviruses and DNA viruses that do not contain oncgenes. The RNA genomes of all retroviruses without oncgenes measure only 8 to 9 kilobases (13, 22). They all encode three major essential genes which virtually exhaust their coding capacity. These are in the 5' to 3' map order gag which encodes the viral core protein, pol which encodes the reverse transcriptase, and env which encodes the envelope glycoprotein (23, 24). The retroviruses are also considered to be plausible natural carcinogens because they are not cytocidal and hence compatible with neoplastic growth and other slow diseases. Indeed, retroviruses are the only viruses that depend on mitosis for replication (13, 25). ]
Nice gag, pol env definitions for me. So when they do the gene sequencing they'll find out differences in the envelope proteins? And maybe there are some slow growing cancers that could be xmrv related too?
 

Rosemary

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Nice gag, pol env definitions for me. So when they do the gene sequencing they'll find out differences in the envelope proteins? And maybe there are some slow growing cancers that could be xmrv related too?
Yes I agree the definitions are very good, as far as the connection to cancer I am certain that when Vincent Rancaniello interviewed Stephen Goff they talked about XMRV ? being able to transduce the RAS gene ? I'm not sure what that means exactly ?

Apart from this information here
"The conversion of ras from a proto-oncogene into an oncogene usually occurs through a point mutation in the gene. The altered function can affect the cell in different ways because ras is involved in many signaling pathways that control cell division and cell death. "

" Mutant ras has been identified in cancers of many different origins, including: pancreas (90%), colon (50%), lung (30%), thyroid (50%), bladder (6%), ovarian (15%), breast, skin, liver, kidney, and some leukemias. "

http://www.cancerquest.org/index.cfm?page=553

If XMRV is able to tranduce the RAS gene does that mean it causes a point mutation like above ?

Sorry I just tried to listen to the podcast again and I haven't found the reference that they made to the RAS gene but I don't think they are talking about XMRV because they said no one has found XMRV integrated next to an oncogene
 

spindrift

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...you would probably have as much chance of finding XMRV with a fishing rod!
:tear::tear::tear:


Laying here with visions of people in white lab coats casting a baited hook into a petri dish.
Can anyone come up with an appropriate latin name for that testing method?