Multiple pathogens and prostate cancer.

BACKGROUND: The aim of this review is to consider whether multiple pathogens have roles in prostate cancer. METHODS: We have reviewed case control studies in which infectious pathogens in prostate cancer were compared to normal and benign prostate tissues. We also reviewed additional evidence from relevant published articles. RESULTS: We confirmed that high risk human papilloma viruses are a probable cause of prostate cancer. We judged Escherichia coli, Cutibacterium acnes, Neisseria gonorrhoea, Herpes simplex, Epstein Barr virus and Mycoplasmas as each having possible but unproven roles in chronic prostatic inflammation and prostate cancer. We judged Cytomegalovirus, Chlamydia trachomatis, Trichomonas vaginalis and the Polyoma viruses as possible but unlikely to have a role in prostate cancer. CONCLUSIONS AND ACTIONS: The most influential cause of prostate cancer appears to be infection induced chronic inflammation. Given the high prevalence of prostate cancer it is important for action to can be taken without waiting for additional conclusive evidence. These include: 1. Encouragement of all boys (as well as girls) to have HPV vaccines 2. The vigorous use of antibiotics to treat all bacterial pathogens identified in the urogenital tract 3. The use of antiviral medications to control herpes infections 4. Education about safe sexual practices.

Mouse Mammary Tumour Virus (MMTV) in Human Breast Cancer-The Value of Bradford Hill Criteria.

For many decades, the betaretrovirus, mouse mammary tumour virus (MMTV), has been a causal suspect for human breast cancer. In recent years, substantial new evidence has been developed. Based on this evidence, we hypothesise that MMTV has a causal role. We have used an extended version of the classic A. Bradford Hill causal criteria to assess the evidence. 1. Identification of MMTV in human breast cancers: The MMTV 9.9 kb genome in breast cancer cells has been identified. The MMTV genome in human breast cancer is up to 98% identical to MMTV in mice. 2. EPIDEMIOLOGY: The prevalence of MMTV positive human breast cancer is about 35 to 40% of breast cancers in Western countries and 15 to 20% in China and Japan. 3. Strength of the association between MMTV and human breast cancer: Consistency-MMTV env gene sequences are consistently five-fold higher in human breast cancer as compared to benign and normal breast controls. 4. Temporality (timing) of the association: MMTV has been identified in benign and normal breast tissues up to 10 years before the development of MMTV positive breast cancer in the same patient. 5. EXPOSURE: Exposure of humans to MMTV leads to development of MMTV positive human breast cancer. 6. Experimental evidence: MMTVs can infect human breast cells in culture; MMTV proteins are capable of malignantly transforming normal human breast epithelial cells; MMTV is a likely cause of biliary cirrhosis, which suggests a link between MMTV and the disease in humans. 7. Coherence-analogy: The life cycle and biology of MMTV in humans is almost the same as in experimental and feral mice. 8. MMTV Transmission: MMTV has been identified in human sputum and human milk. Cereals contaminated with mouse fecal material may transmit MMTV. These are potential means of transmission. 9. Biological plausibility: Retroviruses are the established cause of human cancers. Human T cell leukaemia virus type I (HTLV-1) causes adult T cell leukaemia, and human immunodeficiency virus infection (HIV) is associated with lymphoma and Kaposi sarcoma. 10. Oncogenic mechanisms: MMTV oncogenesis in humans probably differs from mice and may involve the enzyme APOBEC3B. CONCLUSION: In our view, the evidence is compelling that MMTV has a probable causal role in a subset of approximately 40% of human breast cancers.

Infection and food combine to cause atherosclerotic coronary heart disease - Review and hypothesis.

HYPOTHESIS: It is hypothesised that a combination of childhood and later life infections and excess food consumption, particularly of Western style food, initiates and contributes to atherosclerotic coronary heart disease. To consider this hypothesis we have conducted a brief review of the role of childhood infections, food, and their combined influence on atherosclerosis. EVIDENCE: (i) Studies of populations with high prevalence of infections and low "hunter gather" like food consumption, have extremely low prevalence of atherosclerosis, (ii) there are consistent associations between infections in childhood and adult atherosclerotic coronary heart disease, (iii) there is an association between increased body weight, (an indication of excess eating), and atherosclerotic heart disease, and (iv) there is evidence that a combination of increased body weight and infections influences the development of atherosclerotic coronary heart disease.Infections do not appear to act independently to cause atherosclerosis. A combination of both food and infection appears to be required to cause atheroma. CONCLUSION: The hypothesis that infections when combined with excess eating initiates atherosclerosis, is plausible. ACTION: Action aimed at prevention of atherosclerotic heart disease is possible. There are three safe approaches to prevention (i) encouragement of Mediterranean like diets, (ii) avoidance of overeating and (iii) vigorous control of infections among all age groups. There is a need to monitor patients with a history of serious childhood infections and poor nutrition. In addition, for high risk subjects, cholesterol lowering statins are of proven and safe value.

Catching viral breast cancer.

We have considered viruses and their contribution to breast cancer. MOUSE MAMMARY TUMOUR VIRUS: The prevalence of mouse mammary tumour virus (MMTV) is 15-fold higher in human breast cancer than in normal and benign human breast tissue controls. Saliva is the most plausible means of transmission. MMTV has been identified in dogs, cats, monkeys, mice and rats. The causal mechanisms include insertional oncogenesis and mutations in the protective enzyme ABOBEC3B. HUMAN PAPILLOMA VIRUS: The prevalence of high risk human papilloma viruses (HPV) is frequently six fold higher in breast cancer than in normal and benign breast tissue controls. Women who develop HPV associated cervical cancer are at higher than normal risk of developing HPV associated breast cancer. Koilocytes have been identified in breast cancers which is an indication of HPV oncogenicity. The causal mechanisms of HPVs in breast cancer appear to differ from cervical cancer. Sexual activity is the most common form of HPV transmission. HPVs are probably transmitted from the cervix to the breast by circulating extra cellular vesicles. EPSTEIN BARR VIRUS: The prevalence of Epstein Barr virus (EBV) is five fold higher in breast cancer than in normal and benign breast tissue controls. EBV is mostly transmitted from person to person via saliva. EBV infection predisposes breast epithelial cells to malignant transformation through activation of HER2/HER3 signalling cascades. EBV EBNA genes contribute to tumour growth and metastasis and have the ability to affect the mesenchymal transition of cells. BOVINE LEUKEMIA VIRUS: Bovine leukemia virus (BLV) infects beef and dairy cattle and leads to various cancers. The prevalence of BLV is double in human breast cancers compared to controls. Breast cancer is more prevalent in red meat eating and cow's milk consuming populations. BLV may be transmitted to humans from cattle by the consumption of red meat and cow's milk. CONCLUSION: The evidence that MMTV, high risk HPVs and EBVs have causal roles in human breast cancer is compelling. The evidence with respect to BLV is more limited but it is likely to also have a causal role in human breast cancer.

Evidence for a causal role by human papillomaviruses in prostate cancer - a systematic review.

It is hypothesised that high risk for cancer human papillomaviruses (HPVs) have a causal role in prostate cancer. In 26 case control studies, high risk HPVs have been identified in benign and prostate cancers. High risk HPVs were identified in 325 (22.6%) of 1284 prostate cancers and in 113 (8.6%) of 1313 normal or benign prostate controls (p = 0.001). High risk HPVs of the same type have been identified in both normal and benign prostate tissues prior to the development of HPV positive prostate cancer. High risk HPVs can be associated with inflammatory prostatitis leading to benign prostate hyperplasia and later prostate cancer. Normal human prostate epithelial cells can be immortalised by experimental exposure to HPVs. HPVs are probably sexually transmitted. The role of HPVs in prostate cancer is complex and differs from HPVs associated cervical cancer. HPV infections may initiate prostate oncogenesis directly and influence oncogenesis indirectly via APOBEC enzymes. HPVs may collaborate with other pathogens in prostate oncogenesis. Although HPVs are only one of many pathogens that have been identified in prostate cancer, they are the only infectious pathogen which can be prevented by vaccination. A causal role for HPVs in prostate cancer is highly likely.

Evidence for a causal role by mouse mammary tumour-like virus in human breast cancer.

We have reviewed the evidence relevant to mouse mammary tumour viruses (MMTV) and human breast cancer. The prevalence of MMTV- like gene sequences is 15-fold higher in human breast cancer than in normal human breast tissue controls and is present in up to 40% of human breast cancers. MMTV-like gene sequences can be identified in benign breast tissues 1-11 years before the development of positive MMTV-like breast cancer in the same women. The prevalence of MMTV antibodies in sera from women with breast cancer is 5-fold higher than in normal women. MMTV can infect human breast epithelial cells and integrate at random into the human genome located in those cells. MMTV-like gene sequences are present in human milk from normal lactating women and with increased prevalence in milk from women at risk of breast cancer. MMTV-like virus associated human breast cancer has strikingly similar features to MMTV-associated mouse mammary tumours. These features include almost identical nucleotide sequences and structure of the MMTV genome, histology, superantigen expression, MMTV infection of B and T lymphocytes and hormone dependence. MMTV-like gene sequences have also been identified in dogs, cats, monkeys, mice and rats. Saliva has been identified as the most plausible means of transmission from human to human and possibly from dogs to humans. The evidence meets the classic causal criteria. A causal role for MMTV-like viruses in human breast cancer is highly likely.

Association of Mouse Mammary Tumor Virus With Human Breast Cancer: Histology, Immunohistochemistry and Polymerase Chain Reaction Analyses.

PURPOSE: The purpose of this study is to determine whether mouse mammary tumor virus (MMTV)-associated human breast cancer has the same or similar histology to MMTV-associated mouse mammary tumors. Such associations may indicate a role for MMTV in human breast cancer. METHODS: Immunohistochemical techniques (using antibodies directed against the signal peptide p14 of the envelope precursor protein of MMTV) and polymerase chain reaction (PCR) analyses were used to identify MMTV proteins and MMTV-like envelope gene sequences in a series of breast cancers from Australian women. The histological characteristics of these human breast cancer specimens were compared with MMTV positive mouse mammary tumors. The same methods were used to study benign breast tissues which 1-11 years later developed into breast cancer. RESULTS: MMTV p14 proteins were identified in 27 (54%) of 50 human breast cancers. MMTV env gene sequences were identified by PCR in 12 (27%) of 45 human breast cancers. There was a significant correlation between the presence of MMTV (identified by p14 immunohistochemistry) in human breast cancers and histological characteristics similar to MMTV positive mouse mammary tumors (p = 0.001). There was a non-significant correlation between the presence of MMTV env gene sequences (identified by PCR) in human breast cancers and histological characteristics similar to MMTV positive mouse mammary tumors (p = 0.290). MMTV p14 proteins were identified in 7 (54%) of 13 benign breast specimens that later developed into human breast cancers. MMTV by PCR was identified in two benign specimens one of whom later developed MMTV positive breast cancer. DISCUSSION: These observations offer evidence that MMTV may be associated with characteristic human breast cancer histology. p14-based immunohistochemistry appears to be a more reliable technique than PCR for the identification of MMTV in human breast cancer. Identification of MMTV-associated p14 proteins in benign breast tissues confirms prior PCR-based studies that MMTV infection occurs before the development of MMTV positive breast cancer. CONCLUSION: Many MMTV positive human breast cancers have similar histology to MMTV positive mouse mammary tumors. MMTV infection identified in benign breast tissues precedes development of MMTV positive human breast cancer. When considered in the context of prior studies, these observations indicate a likely role for MMTV in human breast cancer.

Oncogenic Viruses and Breast Cancer: Mouse Mammary Tumor Virus (MMTV), Bovine Leukemia Virus (BLV), Human Papilloma Virus (HPV), and Epstein-Barr Virus (EBV).

BACKGROUND: Although the risk factors for breast cancer are well established, namely female gender, early menarche and late menopause plus the protective influence of early pregnancy, the underlying causes of breast cancer remain unknown. The development of substantial recent evidence indicates that a handful of viruses may have a role in breast cancer. These viruses are mouse mammary tumor virus (MMTV), bovine leukemia virus (BLV), human papilloma viruses (HPVs), and Epstein-Barr virus (EBV-also known as human herpes virus type 4). Each of these viruses has documented oncogenic potential. The aim of this review is to inform the scientific and general community about this recent evidence. THE EVIDENCE: MMTV and human breast cancer-the evidence is detailed and comprehensive but cannot be regarded as conclusive. BLV and human breast cancer-the evidence is limited. However, in view of the emerging information about BLV in human breast cancer, it is prudent to encourage the elimination of BLV in cattle, particularly in the dairy industry. HPVs and breast cancer-the evidence is substantial but not conclusive. The availability of effective preventive vaccines is a major advantage and their use should be encouraged. EBV and breast cancer-the evidence is also substantial but not conclusive. Currently, there are no practical means of either prevention or treatment. Although there is evidence of genetic predisposition, and cancer in general is a culmination of events, there is no evidence that inherited genetic traits are causal. CONCLUSION: The influence of oncogenic viruses is currently the major plausible hypothesis for a direct cause of human breast cancer.

Multiple oncogenic viruses are present in human breast tissues before development of virus associated breast cancer.

BACKGROUND: Multiple oncogenic viruses including, mouse mammary tumor virus, bovine leukemia virus, human papilloma virus, and Epstein Barr virus, have been identified as separate infectious pathogens in human breast cancer. Here we demonstrate that these four viruses may be present in normal and benign breast tissues 1 to 11 years before the development of same virus breast cancer in the same patients. METHODS: We combined the data we developed during investigations of the individual four oncogenic viruses and breast cancer. Patients who had benign breast biopsies 1-11 years prior to developing breast cancer were identified by pathology reports from a large Australian pathology service (Douglas Hanly Moir Pathology). Archival formalin fixed specimens from these patients were collected. The same archival specimens were used for (i) investigations of mouse mammary tumour virus (also known as human mammary tumour virus) conducted at the Icahn School of Medicine at Mount Sinai, New York and at the University of Pisa, Italy, (ii) bovine leukemia virus conducted at the University of California at Berkeley,(iii) human papilloma virus and Epstein Barr virus conducted at the University of New South Wales, Sydney, Australia. Seventeen normal breast tissues from cosmetic breast surgery conducted on Australian patients were used as controls. These patients were younger than those with benign and later breast cancer. RESULTS: Standard and in situ polymerase chain reaction (PCR) methods were used to identify the four viruses. The detailed methods are outlined in the separate publications.: mouse mammary tumor virus, human papilloma virus and Epstein Barr virus (Infect Agent Cancer 12:1, 2017, PLoS One 12:e0179367, 2017, Front Oncol 5:277, 2015, PLoS One 7:e48788, 2012). Epstein Barr virus and human papilloma virus were identified in the same breast cancer cells by in situ PCR. Mouse mammary tumour virus was identified in 6 (24%) of 25 benign breast specimens and in 9 (36%) of 25 breast cancer specimens which subsequently developed in the same patients. Bovine leukemia virus was identified in 18 (78%) of 23 benign breast specimens and in 20 (91%) of 22 subsequent breast cancers in the same patients. High risk human papilloma viruses were identified in 13 (72%) of 17 benign breast specimens and in 13 (76%) of 17 subsequent breast cancers in the same patients. Epstein Barr virus was not identified in any benign breast specimens but was identified in 3 (25%) of 12 subsequent breast cancers in the same patients. Mouse mammary tumour virus 3 (18%), bovine leukemia virus 6 (35%), high risk human papilloma virus 3 (18%) and Epstein Barr virus 5 (29%) were identified in 17 normal control breast specimens. CONCLUSIONS: These findings add to the evidence that multiple oncogenic viruses have potential roles in human breast cancer. This is an important observation because evidence of prior infection before the development of disease is a key criterion when assessing causation.

High risk human papilloma viruses (HPVs) are present in benign prostate tissues before development of HPV associated prostate cancer.

BACKGROUND: Although high risk HPVs are associated with an increased risk of prostate cancer it is not known if they have a causal role. The purpose of this study is to investigate the potential role of human papilloma viruses (HPVs) in prostate cancer. The aims are (i) to investigate the presence and confirm the identity of high risk HPVs in benign prostate tissues prior to the development of HPV positive prostate cancer in the same patients, and (ii) to determine if HPVs are biologically active. METHODS: We used polymerase chain reaction (PCR) to identify HPVs in specimens from 52 Australian men with benign prostate biopsies who 1 to 10 years later developed prostate cancer. Immunohistochemistry (IHC) was used to assess the expression of HPV E7 oncoproteins, cytokeratin and prostate specific antigen (PSA). We used RNASeq data from The Cancer Genome Atlas (TCGA) to identify possible HPV RNA sequences in prostate cancer. RESULTS: HPV screening using standard PCR was conducted on 28 of the 52 sets of benign and later prostate cancers. HPV L1 genes were identified in 13 (46%) benign and 8 (29%) of 28 later prostate cancers in the same patients. HPV E7 genes were identified in 23 (82%) benign and 19 (68%) of 28 subsequent prostate cancers in the same patients. The same HPV types were present in both the benign and subsequent prostate cancers in 9 sets of specimens. HPV type 16 was identified in 15% of benign and 3% of prostate cancers. HPV type 18 was identified in 26% of benign and 16% of prostate cancers. Small numbers of HPV types 45, 47, 76 and 115 were also identified. High confidence RNA-Seq evidence for high risk HPV types 16 and 18 was identified in 12 (2%) of the 502 TCGA prostate cancer transcriptomes. High risk HPV E7 oncoprotein was positively expressed in 23 (82%) of 28 benign prostate specimens but only in 8 (29%) of 28 of the later prostate cancer specimens. This difference is statistically significant (p = 0.001). Prostate specific antigen (PSA) was more highly expressed in 26 (50%) of 52 prostate cancer specimens as compared to prior benign prostate specimens in the same patients. CONCLUSIONS: High risk HPVs are present in benign prostate tissues prior to the development of HPV positive prostate cancer. There is a significantly higher expression of HPV E7 oncoproteins in benign prostate tissues as compared to late prostate cancer that subsequently developed in the same patients. This observation suggests that HPV oncogenic activity is an early phenomenon in a majority of prostate oncogenesis. TCGA RNA-Seq data suggests that HPV is biologically active in some prostate tumour samples.

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 env sequences) in Australian benign breast biopsy specimens from women who several years later developed breast cancer. Murine contamination was excluded by stringent laboratory procedures, and the absence of intracisternal A particle sequences and mitochondrial cyclooxygenase sequences. RESULTS: MMTV-like env sequences (also called HMTV sequences to denote their source) were found in 9 of 25 breast cancer specimens (36%). Among 25 non-cancerous breast biopsies of these same patients taken 1 to 11 years earlier, six contained MMTV-like sequences (24%). Five of the six were among the nine virally-associated breast cancers. In two pairs of specimens, benign and malignant, env sequences were 97% identical. CONCLUSIONS: The identification of MMTV (MMTV-like) sequences in breast tissues prior to the development of MMTV positive breast cancer fulfills a key criterion for a possible causal role for the MMTV-like virus in human breast cancer.

Human Papilloma Viruses and Breast Cancer - Assessment of Causality.

High risk human papilloma viruses (HPVs) may have a causal role in some breast cancers. Case-control studies, conducted in many different countries, consistently indicate that HPVs are more frequently present in breast cancers as compared to benign breast and normal breast controls (odds ratio 4.02). The assessment of causality of HPVs in breast cancer is difficult because (i) the HPV viral load is extremely low, (ii) HPV infections are common but HPV associated breast cancers are uncommon, and (iii) HPV infections may precede the development of breast and other cancers by years or even decades. Further, HPV oncogenesis can be indirect. Despite these difficulties, the emergence of new evidence has made the assessment of HPV causality, in breast cancer, a practical proposition. With one exception, the evidence meets all the conventional criteria for a causal role of HPVs in breast cancer. The exception is "specificity." HPVs are ubiquitous, which is the exact opposite of specificity. An additional reservation is that the prevalence of breast cancer is not increased in immunocompromised patients as is the case with respect to HPV-associated cervical cancer. This indicates that HPVs may have an indirect causal influence in breast cancer. Based on the overall evidence, high-risk HPVs may have a causal role in some breast cancers.

Identification of Human Papilloma Viruses in Atheromatous Coronary Artery Disease.

OBJECTIVE: To identify human papilloma viruses (HPV) in atheromatous coronary arteries. BACKGROUND: Atheromatous arterial disease is primarily an initial inflammatory response to unknown stimuli. The crucial question is "what causes the initial inflammation in atheromatous disease?" HPV infections may be relevant as US women with vaginal, high risk for cancer, HPV infections, are at up to threefold increased risk of cardiovascular disease as compared with vaginal HPV-negative women. These studies did not include analyses of HPV in atheromatous coronary arteries. METHODS: Atheromatous coronary arteries were identified and collected from 20 deceased donors. Polymerase Chain Reaction techniques were used to identify HPV gene sequences. Immunohistochemistry methods were used to identify HPV E7 proteins. RESULTS: HPV types 16 and 18 were identified in 11 (55%) of 20 specimens. HPV E7 protein was identified in 10 (50%) of 20 specimens. Positive and negative HPV identification and HPV E7 expression in coronary smooth muscle cells were significantly correlated (cc = 0.503, p = 0.024). The HPV E7 proteins were expressed in smooth muscle cells and plasma cells, foam cells, and macrophages located in the atheromatous plaque. HPV E7 proteins were not expressed in infiltrating lymph cells. CONCLUSION: HPV gene sequences were identified in 55% of atheromatous coronary arteries and may have a role in coronary artery disease.

Early Human Papilloma Virus (HPV) Oncogenic Influences in Breast Cancer.

BACKGROUND: Human papilloma viruses (HPVs) may act early in breast oncogenesis ("hit-and-run" phenomena). METHODS: The authors used immunohistochemistry for the identification of HPV E7 oncogenic protein expression in 32 sets of benign and subsequent breast cancer specimens from the same Australian patients. RESULTS: HPV E7 oncoprotein was clearly expressed in the nuclei of 23 (72%) of the 32 benign specimens and 20 (62.5%) of the subsequent 32 breast cancer specimens in the same patients. There was no HPV E7 protein expression in seven (30%) of the 23 breast cancer specimens that had prior HPV E7 protein-positive benign breast biopsies in the same patients. CONCLUSIONS: This observation suggests that HPV oncogenic influences occur early in some breast cancers. This finding confirms the previous observations. This early influence of HPVs may be the reason why there is no increase in the prevalence of HPV-associated breast cancer in immunocompromised patients as compared to HPV-associated cervical cancer.

Human Papilloma Virus Identification in Breast Cancer Patients with Previous Cervical Neoplasia.

PURPOSE: Women with human papilloma virus (HPV)-associated cervical neoplasia have a higher risk of developing breast cancer than the general female population. The purpose of this study was to (i) identify high-risk HPVs in cervical neoplasia and subsequent HPV positive breast cancers which developed in the same patients and (ii) determine if these HPVs were biologically active. METHODS: A range of polymerase chain reaction and immunohistochemical techniques were used to conduct a retrospective cohort study of cervical precancers and subsequent breast cancers in the same patients. RESULTS: The same high-risk HPV types were identified in both the cervical and breast specimens in 13 (46%) of 28 patients. HPV type 18 was the most prevalent. HPVs appeared to be biologically active as demonstrated by the expression of HPV E7 proteins and the presence of HPV-associated koilocytes. The average age of these patients diagnosed with breast cancer following prior cervical precancer was 51 years, as compared to 60 years for all women with breast cancer (p for difference = 0.001). CONCLUSION: These findings indicate that high-risk HPVs can be associated with cervical neoplasia and subsequent young age breast cancer. However, these associations are unusual and are a very small proportion of breast cancers. These outcomes confirm and extend the observations of two similar previous studies and offer one explanation for the increased prevalence of serious invasive breast cancer among young women.

Human Papilloma Viruses and Breast Cancer.

PURPOSE: Human papillomaviruses (HPV) may have a role in some breast cancers. The purpose of this study is to fill important gaps in the evidence. These gaps are: (i) confirmation of the presence of high risk for cancer HPVs in breast cancers, (ii) evidence of HPV infections in benign breast tissues prior to the development of HPV-positive breast cancer in the same patients, (iii) evidence that HPVs are biologically active and not harmless passengers in breast cancer. METHODS: RNA-seq data from The Cancer Genome Atlas (TCGA) was used to identify HPV RNA sequences in breast cancers. We also conducted a retrospective cohort study based on polymerase chain reaction (PCR) analyses to identify HPVs in archival specimens from Australian women with benign breast biopsies who later developed breast cancer. To assess whether HPVs in breast cancer were biologically active, the expression of the oncogenic protein HPV E7 was assessed by immunohistochemistry (IHC). RESULTS: Thirty (3.5%) low-risk and 20 (2.3%) high-risk HPV types were identified in 855 breast cancers from the TCGA database. The high risk types were HPV 18 (48%), HPV 113 (24%), HPV 16 (10%), HPV 52 (10%). Data from the PCR cohort study indicated that HPV type 18 was the most common type identified in breast cancer specimens (55% of 40 breast cancer specimens) followed by HPV 16 (13%). The same HPV type was identified in both the benign and subsequent breast cancer in 15 patients. HPV E7 proteins were identified in 72% of benign breast specimens and 59% of invasive breast cancer specimens. CONCLUSION: There were four observations of particular interest: (i) confirmation by both NGS and PCR of the presence of high-risk HPV gene sequences in breast cancers, (ii) a correlation between high-risk HPV in benign breast specimens and subsequent HPV-positive breast cancer in the same patient, (iii) HPVs in breast cancer are likely to be biologically active (as shown by transcription of HPV DNA to RNA plus the expression of HPV E7 proteins), (iv) HPV oncogenic influences may occur early in the development of breast cancer.

Human papillomavirus and Epstein Barr virus in prostate cancer: Koilocytes indicate potential oncogenic influences of human papillomavirus in prostate cancer.

INTRODUCTION: The purpose of this study is to determine if high risk human papillomaviruses (HPV) and Epstein Barr virus (EBV) are both present in the same prostate cancer specimens. METHODS: We used a range of analytical techniques including in situ polymerase chain reaction (IS-PCR) and standard liquid PCR followed by sequencing of the product to seek to identify HPV and EBV in normal, benign, and malignant prostate tissues. RESULTS: Both HPV type 18 and EBV gene sequences were identified in a high and approximately equal proportion of normal, benign, and prostate cancer specimens. These sequences were located in the nuclei of prostate epithelial cells. HPV associated koilocytes were identified in 24% of prostate cancer specimens. CONCLUSIONS: The presence of both HPV and EBV gene sequences in most of the same normal, benign, and malignant prostate specimens is particularly noteworthy because of recent experimental evidence demonstrating that EBV and HPV can collaborate to increase proliferation of cultured cervical cells. Because the presence of EBV and HPV in normal, benign, and malignant prostate tissues appears to be ubiquitous, it is possible that they are harmless. On the other hand HPV type 18 in particular, has high oncogenic potential and may be associated with some prostate cancers. The identification of HPV associated koilocytes in prostate cancer specimens is an indication of HPV infection and potential oncogenic influences of human papillomavirus in prostate cancer.

Epstein-Barr virus, human papillomavirus and mouse mammary tumour virus as multiple viruses in breast cancer.

BACKGROUND: The purpose of this investigation is to determine if Epstein Barr virus (EBV), high risk human papillomavirus (HPV), and mouse mammary tumour viruses (MMTV) co-exist in some breast cancers. MATERIALS AND METHODS: All the specimens were from women residing in Australia. For investigations based on standard PCR, we used fresh frozen DNA extracts from 50 unselected invasive breast cancers. For normal breast specimens, we used DNA extracts from epithelial cells from milk donated by 40 lactating women. For investigations based on in situ PCR we used 27 unselected archival formalin fixed breast cancer specimens and 18 unselected archival formalin fixed normal breast specimens from women who had breast reduction surgery. Thirteen of these fixed breast cancer specimens were ductal carcinoma in situ (dcis) and 14 were predominantly invasive ductal carcinomas (idc). RESULTS: EBV sequences were identified in 68%, high risk HPV sequences in 50%, and MMTV sequences in 78% of DNA extracted from 50 invasive breast cancer specimens. These same viruses were identified in selected normal and breast cancer specimens by in situ PCR. Sequences from more than one viral type were identified in 72% of the same breast cancer specimens. Normal controls showed these viruses were also present in epithelial cells in human milk - EBV (35%), HPV, 20%) and MMTV (32%) of 40 milk samples from normal lactating women, with multiple viruses being identified in 13% of the same milk samples. CONCLUSIONS: We conclude that (i) EBV, HPV and MMTV gene sequences are present and co-exist in many human breast cancers, (ii) the presence of these viruses in breast cancer is associated with young age of diagnosis and possibly an increased grade of breast cancer.

High risk human papillomavirus and Epstein Barr virus in human breast milk.

BACKGROUND: Multiple viruses, including human immunodeficiency virus, Epstein Barr virus (EBV) and mouse mammary tumour virus have been identified in human milk. High risk human papillomavirus (HPV) sequences have been identified in breast cancer. The aim of this study is to determine if viral sequences are present in human milk from normal lactating women. FINDINGS: Standard (liquid) and in situ polymerase chain reaction (PCR) techniques were used to identify HPV and EBV in human milk samples from normal lactating Australian women who had no history of breast cancer.High risk human papillomavirus was identified in milk samples of 6 of 40 (15%) from normal lactating women - sequencing on four samples showed three were HPV 16 and one was HPV 18. Epstein Barr virus was identified in fourteen samples (33%). CONCLUSION: The presence of high risk HPV and EBV in human milk suggests the possibility of milk transmission of these viruses. However, given the rarity of viral associated malignancies in young people, it is possible but unlikely, that such transmission is associated with breast or other cancers.