Secondary analysis of Human Mammary Tumor Virus (HMTV) in breast cancer.

 描述（由申请人提供）：自从发现小鼠乳腺肿瘤病毒（MMTV）作为小鼠乳腺肿瘤的病原体以来，人们做出了大量努力来确定类似的病毒是否可能参与人类乳腺癌的发病机制。对这一问题的重新关注始于20世纪90年代中期，当时我们报道了在38%（314例中的226例）的美国女性乳腺癌标本中检测到一个660 bp的序列，该序列与MMTV包膜（env）基因同源性为90%至98%，与任何人类基因或人类内源性逆转录病毒（HERV）或任何其他病毒均无显著同源性。其他实验室和我们自己的实验室在不同地理区域的人群中也发现了类似的结果。 随后，在人乳腺肿瘤中检测到的9.9 kb前病毒序列被扩增，并发现与MMTV具有95%的同源性，被命名为HMTV。具有β逆转录病毒特征的HMTV病毒颗粒已经从转移性乳腺癌细胞（MMSM细胞）的原代培养物中分离，所述细胞从患有转移性乳腺癌的患者的胸腔和腹腔积液中建立。这些病毒颗粒的RNA序列与MMTV的同源性为85 - 95%。最近，我们已经证明，来自MSSM细胞的HMTV能够感染人乳腺上皮细胞（HMEC）、外周血单核细胞（PBMC）、健康供体的树突状细胞和以下细胞系：MCF 10 A、MCF 10 F、293 T、拉莫斯（B细胞）、Jurkat（T细胞）的原代培养物并在其中复制。在感染的MCF 10 F细胞中，上皮细胞特有的蛋白质如E钙粘蛋白的表达减少，间充质细胞特有的蛋白质如波形蛋白的表达增加。这种现象是当健康上皮细胞变成肿瘤时观察到的上皮间充质转化过程的典型现象。尽管有大量证据支持HMTV在人类乳腺癌中的存在，但关于其相关性和准确性的争议仍在继续。此外，对人类疾病中的鼠样病毒的研究目前正受到严格的审查和批评，主要是由于发现异嗜性鼠白血病病毒相关病毒（XMRV）被认为在人类前列腺癌和慢性疲劳综合征（CFS）中起作用，现在似乎是小鼠污染物。 在本申请中，我们建议使用可以保证无污染结果的技术来证明HMTV存在于人类乳腺癌中。如果乳腺癌中的HMTV是小鼠DNA污染的结果，则可以通过这项拟议的研究来确定。使用敏感的检测方法的初步数据显示，当HMTV被发现时，没有检测到小鼠DNA污染。此外，HMTV已经在乳腺癌标本的细胞核中可视化，以及整合在MSSM细胞的染色体中。这些数据的扩展可以为科学界提供令人信服的证据，证明HMTV不是污染物

 DESCRIPTION (provided by applicant): Since the discovery of Mouse Mammary Tumor Virus (MMTV) as the etiological agent of mammary tumors in mice there have been numerous efforts to determine if a similar agent might be involved in the pathogenesis of human breast cancer. Renewed interest in this issue began in the middle 1990's when we reported that a 660 bp sequence, 9098% homologous to the MMTV envelope (env) gene, with no significant homology to any human gene or human endogenous retrovirus (HERV) nor to any other virus, was detected in 38% (226 of 314) of American women's breast cancers specimens. Similar results have been found across populations from different geographic regions by other laboratories as well as our own. Subsequently a 9.9 kb proviral sequence detected in human breast tumors, amplified, and found to be 95% homologous to MMTV was designated as HMTV. HMTV viral particles with betaretrovirus characteristics have been isolated from primary cultures of metastatic breast cancer cells (MMSM cells) established from pleural and abdominal effusions of patients with metastatic breast cancer. The RNA sequence of these viral particles was 8595% homologous to MMTV. Recently we have shown that HMTV from MSSM cells is able to infect and replicate in primary cultures of human mammary epithelial cells (HMEC), peripheral blood mononuclear cells (PBMC), dendritic cells of healthy donors and the following cell lines: MCF10A, MCF10F, 293T, Ramos (B cells), Jurkat (T cells). In the infected MCF10F cells, expression of proteins characteristic of epithelial cells such as Ecadherin decreased and the expression of proteins characteristic of mesenchymal cells such as Vimentin increased. This phenomenon is typical of the process of Epithelial Mesenchymal Transition observed when healthy epithelial cells become neoplastic. Despite the substantial evidence supporting the presence of HMTV in human breast cancer, controversy continues concerning its relevance and veracity. In addition, the study of murine like viruses in human disease is currently under intense scrutiny and criticism, mainly due to the finding that Xenotropic Murine Leukemia virusrelated virus (XMRV) which was thought to play a role in human prostate cancer and in chronic fatigue syndrome (CFS) now appears to be a mouse contaminant. In this application we propose to demonstrate that HMTV is present in human breast cancer using techniques that can guarantee results free of contamination. If HMTV in breast cancer were the result of murine DNA contamination, it could be determined by this proposed study. Preliminary data using sensitive assays show no detection of murine DNA contamination when HMTV is found. In addition, HMTV has been visualized in the nucleus of breast cancer specimens as well as integrated in chromosomes of MSSM cells. Expansion of these data can provide convincing evidence to the scientific community that HMTV is not a contaminant