• Welcome to Phoenix Rising!

    Created in 2008, Phoenix Rising is the largest and oldest forum dedicated to furthering the understanding of and finding treatments for complex chronic illnesses such as chronic fatigue syndrome (ME/CFS), fibromyalgia (FM), long COVID, postural orthostatic tachycardia syndrome (POTS), mast cell activation syndrome (MCAS), and allied diseases.

    To become a member, simply click the Register button at the top right.

No evidence for the involvement of XMRV in the pathogenesis of breast cancer

Jemal

Senior Member
Messages
1,031
Looks like another negative study... but read on.

British Journal of Cancer , (16 February 2012) | doi:10.1038/

No evidence for the involvement of XMRV or MCV in the pathogenesis of breast cancer

G Khan, P S Philip, M Naase and K M I Al Zarouni

Abstract
Background:

The aetiology of breast cancer remains elusive. A viral aetiology has been proposed, but to date no virus has been conclusively demonstrated to be involved. Recently, two new viruses, namely Merkel cell polyomavirus (MCV) and xenotropic murine leukaemia virus-related virus (XMRV) have been identified and implicated in the pathogenesis of Merkel cell carcinoma (MCC) and familial form of prostate cancer, respectively.

Methods:

We examined 204 samples from 58 different cases of breast cancer for presence of MCV or XMRV by PCR. Samples consisted of both malignant and non-malignant tissues. Additionally, we included 6 cases of MCC and 12 cases of prostate cancer as potential controls for MCV and XMRV, respectively.

Results:

All of the breast cancer samples examined were negative for both MCV and XMRV. However, 4/6 MCC and 2/12 prostate cancer samples were found to be positive for MCV and XMRV, respectively. Sequence analysis of the amplified products confirmed that these sequences belonged to MCV and XMRV.

Conclusion:

We conclude that there is no evidence for the involvement of MCV or XMRV in the pathogenesis of breast cancer. What role these viruses have in the pathogenesis of MCC and prostate carcinomas remains to be demonstrated.

http://www.nature.com/bjc/journal/vaop/ncurrent/full/bjc201251a.html
 

lansbergen

Senior Member
Messages
2,512
Additionally, we included 6 cases of MCC and 12 cases of prostate cancer as potential controls for MCV and XMRV, respectively.

However, 4/6 MCC and 2/12 prostate cancer samples were found to be positive for MCV and XMRV, respectively. Sequence analysis of the amplified products confirmed that these sequences belonged to MCV and XMRV.

Do I read this correct? 6 out of 6 and 12 out of 12 positive for XMRV?
 

lansbergen

Senior Member
Messages
2,512
Additionally, we included 6 cases of MCC and 12 cases of prostate cancer as potential controls for MCV and XMRV, respectively.


I missed this

Now I think there were 4 MCC samples positive for MCV and 2 prostate cancer samples positive for XMRV
 

Bob

Senior Member
Messages
16,455
Location
England (south coast)
So, another positive XMRV study.

I haven't got access to the full paper, but this study is interesting because the negative results for the breast cancer samples suggest that the lab is not contaminated. Although, without reading the paper, it's not possible to tell if all samples were handled in the same way.

They should have looked for the mouse mammary tumour virus in the breast cancer samples.
 

Ecoclimber

Senior Member
Messages
1,011
From the Khan et al. paper.

"In this study,we found 2 of the 12 prostate samples to be positive for XMRV. One of the two XMRV amplified products was subsequently sequenced and clearly identified as belonging to XMRV VP62 genome. However, the sequence amplified in our case had several mutations compared to XMRV VP62 genome, suggesting that the source of XMRV in this sample was not due to contamination from plasmid XMRV VP62 used as a positive control.

We had limited material from these two XMRV-positive prostate samples, and as such we were not able to confirm our findings using alternative primers targeting separate regions of XMRV. Thus, the possibility that the single nucleotide differences found in our case is due to sequencing errors cannot be excluded."

BLASTed XMRV sequence from the one prostate cancer patient in the Khan et al. paper. The closest match was to a Lo et al. PNAS sequence: "CFS isolate BD-22".

Eco
 

currer

Senior Member
Messages
1,409
CFS isolate BD22 is a polytropic mERV gag gene.
Incidentally BD22 is not a CFS patient, but a healthy blood donor.

We are expecting the env viral sequence found in PWME to be polytropic not xenotropic.