Erratum to: Mouse mammary tumor-like virus (MMTV) is present in human breast tissue before development of virally associated breast cancer.

[This corrects the article DOI: 10.1186/s13027-016-0113-6.].

Mouse mammary tumor-like virus (MMTV) is present in human breast tissue before development of virally associated breast cancer.

Background: There is substantial evidence that a virus homologous to mouse mammary tumor virus (MMTV) may have a role in human breast cancer. The present study indicates that those who developed breast cancer associated with an MMTV-like virus had this virus in their non-cancerous breast tissues years before the cancer developed.

Methods: Polymerase chain reaction (PCR) techniques and sequencing were used to identify MMTV-like envelope gene sequences (MMTV-like sequences) in Australian benign breast biopsy specimens from women who several years later developed breast cancer.

Human Mammary Tumor Virus (HMTV) sequences in human milk.

Background: Retroviral sequences 90-95% homologous to the mouse mammary tumor virus (MMTV) were present in 38% of the breast cancers studied from American women and were not detectable in non-tumor breast tissue from the same patient. The entire proviral structure was described and viral particles were isolated from primary cultures of human breast cancer. This virus was designated as human mammary tumor virus (HMTV).

Human mammary tumor virus (HMTV) in endometrial carcinoma.

Objective: Human mammary tumor virus (HMTV) is 90% to 98% homologous to mouse mammary tumor virus, the etiological agent of mammary tumors in mice. Human mammary tumor virus sequences were found in 40% of the breast cancers studied in both American and Australian women. In addition, 10% of endometrial carcinomas studied in Australian women also contained HMTV sequences.

Human mammary tumor virus in inflammatory breast cancer.

The authors have found that retroviral sequences with 85% to 95% homology to the mouse mammary tumor virus were present in 40% of the sporadic breast cancers of American women. These sequences were not found in normal breasts or other tumors. A whole proviral structure was detected in 2 tumors.

Detection of human mammary tumor virus proteins in human breast cancer cells.

Mouse mammary tumor virus (MMTV) has been proven to induce mammary cancer in mice. MMTV-like env gene sequences have been detected in one-third of the human breast tumors studied. The whole proviral structure with 95% homology to MMTV was found in two human breast tumors and was designated as human mammary tumor virus (HMTV).

Characterization of viral particles isolated from primary cultures of human breast cancer cells.

The association of human breast cancer with sequences similar to the mouse mammary tumor virus (MMTV) has been shown, but convincing evidence for the presence of viral particles in breast tumors has been lacking. We have described the complete proviral structure of a retrovirus in human breast cancer. This provirus, designated as human mammary tumor virus (HMTV), was 95% homologous to MMTV and revealed features of a replication-competent virus.

Expression of Wnt5A and Wnt10B in non-immortalized breast cancer cells.

Wnt signaling is usually divided into two pathways: the 'canonical', acting through beta-catenin, and the 'non-canonical' acting through the Ca2+ and planar cell polarity pathway. Both pathways have been implicated in different types of cancer. Most results obtained with established cell lines have been contradictory.

Transcription profile of a human breast cancer cell line expressing MMTV-like sequences.

Background: It has been postulated that inflammation caused by certain viruses might result in cancer. Recently, it was shown that childhood lymphoblastic leukemia, breast and ovarian cancers express an interferon-related signature, providing support for this notion. We have previously shown that 38% of the sporadic breast cancers contain MMTV-like env gene sequences.

Transcription profiles of non-immortalized breast cancer cell lines.

Background: Searches for differentially expressed genes in tumours have made extensive use of array technology. Most samples have been obtained from tumour biopsies or from established tumour-derived cell lines. Here we compare cultures of non-immortalized breast cancer cells, normal non-immortalized breast cells and immortalized normal and breast cancer cells to identify which elements of a defined set of well-known cancer-related genes are differentially expressed.

Increasing evidence for a human breast carcinoma virus with geographic differences.

Background: An early immunologic study suggesting that a virus similar to the mouse mammary tumor virus (MMTV) was associated highly with breast carcinoma in Tunisian patients, compared with patients in the United States, led the authors to examine different breast carcinoma populations by using more current molecular techniques.

Methods: Thirty-nine paraffin blocks were selected for sequencing of the 250-base pair segment of the MMTV from patients with breast carcinoma who were seen and treated at the Institut Salah Azaiz in Tunisia. Fifteen of those blocks were examined under code by a second laboratory, which used a different methodology and was blinded to the results of the first laboratory, and 14 blocks were analyzed successfully.

A mouse mammary tumor virus-like long terminal repeat superantigen in human breast cancer.

We previously reported a 660-bp mouse mammary tumor virus (MMTV)-like env gene sequence in approximately 38% of human breast cancer DNA, but not in normal breasts or other tumors. This MMTV-like env gene sequence was expressed in 66% of the env gene-positive human breast cancers. An entire proviral structure was identified in human breast cancer DNA with high homology to MMTV and low homology to known human endogenous retrovirus.

Poxvirus infection and apoptosis.

The following excellent reviews have been published on poxviruses and apoptosis during the last few years: P.C. Turner and R.

Effects of pyrethroid insecticides and estrogen on WNT10B proto-oncogene expression.

Breast cancer is a serious illness affecting approximately one in nine women in the United States. Although an actual cause for breast cancer is unknown, genetic and environmental factors have been associated with its onset. Elevated levels of estrogen and heightened expression of the WNT10B proto-oncogene have been implicated in the development of human malignant breast tumors because they enhance the proliferation of mammary tissue.

[Detection of murine mammary tumor virus (MMTV) env gene-like sequences in breast cancer from Argentine patients].

In the last years research on the possible viral etiology of human breast cancer has been revised. Previous studies have demonstrated the presence of a Mouse Mammary Tumor Virus (MMTV) env gene-like sequence in about 38% of breast cancers from American and Italian women; these sequences are generally absent in other tumors and in normal mammary tissue. In the present study we have analyzed the presence of a 250-bp sequence of the MMTV env gene in breast cancer biopsies from Argentine patients.