Epstein-Barr virus and risk of breast cancer: a systematic review and meta-analysis

The relationship between infectious pathogen antibodies, plasma metabolites, and breast cancer: A Mendelian randomization study with mediation analysis

Breast cancer (BC) has the second highest incidence rate among women worldwide. Although there are various treatment methods, the prognosis is poor once metastasis occurs. However, the extent to which pathogens of infectious diseases influence the risk of BC remains unclear. The goal of this study is to determine if these pathogens are causally related to BC development. A Mendelian randomization (MR) analysis is used to assess the causal relationship between infectious pathogen antibodies and the risk of BC, as well as their potential intermediary factors. Two-sample MR analysis using inverse variance weighting (IVW) is conducted to determine the causal relationship between infectious pathogen antibodies and the risk of BC. Additionally, the mediating role of 1400 metabolites between infectious pathogen antibodies and the risk of BC is analyzed. There were 5 infectious pathogen antibodies and 86 metabolites associated with BC (P < .05). There were 14 metabolites that mediated the pathway between infectious pathogen antibodies and BC. X-07765 levels showed a significant negative mediating effect on the relationship between Anti-human herpes virus 6 IgG seropositivity and BC (beta = -0.0025, 95% CI [-0.0046, -0.0003], P = .0236), accounting for 14.8% of the effect (95% CI: 27.7-1.99). This study provides a thorough evaluation of the causal relationships among infectious pathogen antibodies, plasma metabolites, and BC. Our research has identified 5 infectious pathogen antibodies that exhibit a causal relationship with BC, mediated through 86 distinct metabolites.

Human Cytomegalovirus Infection and Breast Cancer: A Literature Review of Clinical and Experimental Data

Breast cancer (BC) remains a significant global health challenge, highlighting the need for continued research into novel risk factors, diagnostic approaches, and personalized treatments. Among emerging risk factors, viral infections have been implicated as potential contributors to breast carcinogenesis and BC progression. Recent evidence suggests that specific oncogenic strains of human cytomegalovirus (HCMV) may have the capacity to transform human mammary epithelial cells. This review assesses clinical data regarding HCMV presence in both tumor and non-tumor breast tissues, examining the role of HCMV oncoproteins in BC development and progression. Current findings indicate a higher prevalence of HCMV infection in breast carcinomas compared to non-tumor tissues, associated with an elevated risk of BC. Additionally, the HCMV-driven breast carcinogenesis model proposed here suggests that HCMV oncoproteins may activate multiple oncogenic pathways, fostering cell proliferation, survival, and tumor development. A deeper understanding of the role of HCMV in BC could enhance risk stratification and support the creation of targeted therapeutic strategies.

The association between infectious agents and breast cancer: a review of the epidemiologic evidence

PURPOSE

Several viruses have been casually linked to human cancers, including cervical, nasopharyngeal, liver, sarcoma, and Merkel cell carcinomas. However, the etiologic contribution of viral infections to breast cancer, the number one incident cancer among women worldwide, is not well established. Among studies exploring associations of viruses with breast cancer, potential linkages have been identified between breast cancer and five viruses: beta retrovirus, (i.e., mouse mammary tumor virus), human papillomavirus, Epstein Barr virus. bovine leukemia virus, and human cytomegalovirus.

METHODS

In this review, we provide a comprehensive evaluation of epidemiological ecologic, case-control, case-only, and cohort studies investigating these associations. We discuss results from several existing reviews and meta-analyses, evaluate epidemiological studies published in the past five years, and assess the relationship between these viruses and breast tumor clinicopathological factors.

RESULTS

The strongest epidemiological evidence for a viral role in breast cancer exists for MMTV and HPV, though limitations include lack of prospective studies for MMTV and potential detection bias in HPV studies. Viral detection challenges have limited studies of EBV and HCMV. Fewer studies have evaluated BLV, and though it has been associated with higher risk of breast cancer, sample sizes are quite small.   CONCLUSION: While epidemiologic evidence exists for an association between these five viruses and breast cancer, various methodological issues and lack of prospective studies preclude robust conclusions. Future research should prioritize establishing a temporal relationship between infection and disease, minimizing misclassification of detection assays, and further exploring the influence of co-infections.

Non-genetic factors and breast cancer: an umbrella review of meta-analyses

BACKGROUND

Previous research has found associations between various non-genetic factors and breast cancer (BrCa) risk. This study summarises and appraises the credibility of the available evidence on the association between non-genetic factors and BrCa risk.

METHODS

We conducted an umbrella review of meta-analyses. Medline, Scopus, and the Cochrane databases were systematically searched for meta-analyses examining non-genetic factors and BrCa incidence or mortality. The strength of the evidence was graded in four categories (i.e., weak, suggestive, highly suggestive, convincing).

RESULTS

A total of 781 meta-analyses from 280 publications were evaluated and graded. We included exposures related to anthropometric measurements, biomarkers, breast characteristics and diseases, diet and supplements, environment, exogenous hormones, lifestyle and social factors, medical history, medication, reproductive history, and pregnancy. The largest number of examined associations was found for the category of diet and supplements and for exposures such as aspirin use and active smoking. The statistically significant (P-value < 0.05) meta-analyses were 382 (49%), of which 204 (53.4%) reported factors associated with increased BrCa risk. Most of the statistically significant evidence (n = 224, 58.6%) was graded as weak. Convincing harmful associations with heightened BrCa risk were found for increased body mass index (BMI), BMI and weight gain in postmenopausal women, oral contraceptive use in premenopausal women, increased androstenedione, estradiol, estrone, and testosterone concentrations, high Breast Imaging Reporting and Data System (BIRADS) classification, and increased breast density. Convincing protective factors associated with lower BrCa risk included high fiber intake and high sex hormone binding globulin (SHBG) levels while highly suggestive protective factors included high 25 hydroxy vitamin D [25(OH)D] levels, adherence to healthy lifestyle, and moderate-vigorous physical activity.

CONCLUSIONS

Our findings suggest some highly modifiable factors that protect from BrCa. Interestingly, while diet was the most studied exposure category, the related associations failed to reach higher levels of evidence, indicating the methodological limitations in the field. To improve the validity of these associations, future research should utilise more robust study designs and better exposure assessment techniques. Overall, our study provides knowledge that supports the development of evidence-based BrCa prevention recommendations and guidance, both at an individual level and for public health initiatives.

TRIAL REGISTRATION

PROSPERO CRD42022370675.

Identification of modules and key genes associated with breast cancer subtypes through network analysis

Breast cancer is the most common malignancy in women around the world. Intratumor and intertumoral heterogeneity persist in mammary tumors. Therefore, the identification of biomarkers is essential for the treatment of this malignancy. This study analyzed 28,143 genes expressed in 49 breast cancer cell lines using a Weighted Gene Co-expression Network Analysis to determine specific target proteins for Basal A, Basal B, Luminal A, Luminal B, and HER2 ampl breast cancer subtypes. Sixty-five modules were identified, of which five were characterized as having a high correlation with breast cancer subtypes. Genes overexpressed in the tumor were found to participate in the following mechanisms: regulation of the apoptotic process, transcriptional regulation, angiogenesis, signaling, and cellular survival. In particular, we identified the following genes, considered as hubs: IFIT3, an inhibitor of viral and cellular processes; ETS1, a transcription factor involved in cell death and tumorigenesis; ENSG00000259723 lncRNA, expressed in cancers; AL033519.3, a hypothetical gene; and TMEM86A, important for regulating keratinocyte membrane properties, considered as a key in Basal A, Basal B, Luminal A, Luminal B, and HER2 ampl breast cancer subtypes, respectively. The modules and genes identified in this work can be used to identify possible biomarkers or therapeutic targets in different breast cancer subtypes.

Association of Human Papilloma Virus, Cytomegalovirus, and Epstein-Barr Virus with Breast Cancer in Jordanian Women

Background and Objectives: The investigation of oncogenic viruses and their potential association with breast cancer (BC) remains an intriguing area of study. The current work aims to assess evidence of three specific viruses, human papillomavirus (HPV), cytomegalovirus (CMV), and Epstein-Barr virus (EBV) in BC samples and to explore their relationship with relevant clinicopathological variables. Materials and Methods: The analysis involved BC samples from 110 Jordanian female patients diagnosed with BC and breast tissue samples from 30 control patients with no evidence of breast malignancy, investigated using real-time PCR. The findings were then correlated with various clinico-pathological characteristics of BC. Results: HPV was detected in 27 (24.5%), CMV in 15 (13.6%), and EBV in 18 (16.4%) BC patients. None of the control samples was positive for HPV or CMV while EBV was detected in only one (3.3%) sample. While (HPV/EBV), (HPV/CMV), and (EBV/CMV) co-infections were reported in 1.8%, 2.7%, and 5.5%, respectively, coinfection with the three viruses (HPV/CMV/EBV) was not reported in our cohort. A statistically significant association was observed between HPV status and age (p = 0.047), and between clinical stage and CMV infection (p = 0.015). Conclusions: Our findings indicate the presence or co-presence of HPV, CMV, and EBV in the BC subpopulation, suggesting a potential role in its development and/or progression. Further investigation is required to elucidate the underlying mechanisms that account for the exact role of oncoviruses in breast carcinogenesis.

Non-Response of Epstein-Barr Virus-Associated Breast Cancer after Primary Chemotherapy: Report of Two Cases

Based on epidemiological evidence and molecular findings, a possible association of Epstein-Barr virus (EBV) with the carcinogenesis of breast cancer has been described. However, the frequency of EBV in breast cancer and the role of EBV regarding tumor progression or therapeutic results is largely unexplored. Here, we report on two cases of advanced, lymph node-positive invasive breast cancer of no special type (NST), histologically showing no clinical or histological evidence of tumor regression as an equivalent of a lack of response to primary systemic therapy. Both tumors were considered to be EBV-associated due to their positivity in EBV-encoded RNA (EBER) in situ hybridization (ISH) and their immunoreactivity against EBV Epstein-Barr nuclear antigen 1 (EBNA1). We hypothesize that the unusual non-response to chemotherapy in these cases of breast cancer classified as triple-negative and HER2-positive may be linked to the EBV co-infection of tumor cells. Therefore, EBV tumor testing should be considered in patients with breast cancer presenting with resistance to chemotherapy. This hypothesis may provide a new aspect in the context of EBV-associated mechanisms of tumor progression.

Epstein-Barr virus in breast carcinoma and in triple negative cases impact on clinical outcomes

BACKGROUND

The contribution of viral infection in tumors pathogenesis has currently attracted attention. Epstein-Barr virus is an infectious agent involved in numerous human malignancies, including breast cancer. Although, their prognostic impact in breast tumor is rarely investigated. Therefore, we sought in our study to evaluate the prevalence of EBV in Tunisian breast carcinoma and to examine their potential association with clinicopathological features and overall survival.

METHODS

Our retrospective study included 100 formalin fixed paraffin embedded samples from Tunisian breast carcinoma. EBV infection was evaluated by immunohistochemical analysis, using monoclonal antibody against latent membrane protein 1 (LMP-1) and polymerase chain reaction. A subset of PCR positive specimens was subjected to in situ hybridization for the detection of EBER expression. Biomarker's expression was evaluated by immunohistochemistry method. Statistical analysis was also explored.

RESULTS

The expression status of ER, PR and HER2 was 81%, 71.4% and 33.7% respectively. The triple negative profile was present in 10.84% of cases. LMP-1 expression was negative in all breast cancer specimens. PCR assay showed that 44% of patients were positive for EBV genome. None of the 15 PCR positive cases showed positive results for EBV by ISH. According to the molecular phenotype, there was a statistically significant difference in EBV DNA prevalence between breast cancer subgroups including TN (67%), Lum B (64%), HER2 + (50%) and Lum A (30%). Bivariate analysis showed that EBV DNA was significantly associated with HER2 + (p = 0.035), tumor size (p = 0.018) and high SBR grade (p = 0.009). Multiple logistic regression analysis confirms the positive correlation of EBV with tumor size (p = 0.048) and SBR grade (p = 0.042). Kaplan-Meier analysis showed that patients with EBV+ had significantly shorter overall survival than those with EBV- (p = 0.032).

CONCLUSIONS

Our study demonstrated the presence of EBV DNA in Tunisian breast carcinoma. EBV DNA was associated with aggressive features and poor overall survival. Further investigations will be required in large samples size to clarify the potential role of EBV in breast tumor progression.

Epstein-Barr Virus (EBV) Epithelial Associated Malignancies: Exploring Pathologies and Current Treatments

Epstein-Barr virus (EBV) is one of eight known herpesviruses with the potential to infect humans. Globally, it is estimated that between 90-95% of the population has been infected with EBV. EBV is an oncogenic virus that has been strongly linked to various epithelial malignancies such as nasopharyngeal and gastric cancer. Recent evidence suggests a link between EBV and breast cancer. Additionally, there are other, rarer cancers with weaker evidence linking them to EBV. In this review, we discuss the currently known epithelial malignancies associated with EBV. Additionally, we discuss and establish which treatments and therapies are most recommended for each cancer associated with EBV.

Association of PD-1/PD-L1 expression and Epstein--Barr virus infection in patients with invasive breast cancer

PURPOSE

Causative factors of breast cancer include infections, such as Epstein-Barr virus (EBV) infection. The aim of this study was to analyze the clinicopathological features of EBV-positive (IBC) and determine if EBV affects programmed cell death receptor 1 (PD-1)/PD ligand 1 (PD-L1) expression in IBC, similar to other EBV-infected tumors with PD-L1/PD-1 expression.

METHODS

We collected 140 samples of IBC tissues and 25 samples of adjacent tissues. All patients were followed-up by telephone from the day of surgery to December 2020. Chromogenic in-situ hybridization was performed to evaluate EBV-encoded RNA (EBER). Immunohistochemistry was performed to evaluate PD-L1 and PD-1 expressions. The correlation between PD1/PDL1 expression and clinicopathological features was also analyzed.

RESULTS

EBER was detected in 57 of 140 (40.7%) IBC tissues and not detected in any adjacent tissue (P < 0.05). Clinicopathologic features of patients were consistent with EBV-associated IBC. EBV infection was correlated with the mass size, menopausal status, axillary lymph node metastasis, vascular invasion, Ki-67 index, clinical stage, and estrogen receptor and progesterone receptor expressions (all P < 0.05), but not with the histological type, invasive ductal carcinoma histological grade, or human epidermal growth factor receptor 2 (HER2) expression (all P > 0.05). The positive rate of PD-1/PD-L1 expression was higher in the EBV-positive group than in the EBV-negative group (P < 0.05). The Kaplan-Meier univariate survival analysis showed that EBV was associated with poor disease-free survival and overall survival in patients with IBC. PD-L1/PD-1 expression could predict a poor prognosis.

CONCLUSIONS

In this study, clinicopathologic characteristics of patients were consistent with EBV-infected IBC. Patients with EBV-positive breast cancer were more likely to have elevated PD-1/PDL-1 expression compared to those with EBV-negative breast cancer. This finding could serve as a basis to explore therapeutic targets, particularly immunotherapy, for patients with IBC.

Estrogen induces the expression of EBV lytic protein ZEBRA, a marker of poor prognosis in nasopharyngeal carcinoma

Several epidemiological studies have suggested that Epstein-Barr virus (EBV) lytic infection is essential for the development of nasopharyngeal carcinoma (NPC), as elevation of antibody titers against EBV lytic proteins is a common feature of NPC. Although ZEBRA protein is a key trigger for the initiation of lytic infection, whether its expression affects the prognosis and pathogenesis of NPC remains unclear. In this study, 64 NPC biopsy specimens were analyzed using immunohistochemistry. We found that ZEBRA was significantly associated with a worsening of progression-free survival in NPC (adjusted hazard ratio, 3.58; 95% confidence interval, 1.08-11.87; P = 0.037). Moreover, ZEBRA expression positively correlated with key endocrinological proteins, estrogen receptor α, and aromatase. The transcriptional level of ZEBRA is activated by estrogen in an estrogen receptor α-dependent manner, resulting in an increase in structural gene expression levels and extracellular virus DNA copy number in NPC cell lines, reminiscent of lytic infection. Interestingly, it did not suppress cellular proliferation or increase apoptosis, in contrast to cells treated with 12-O-tetradecanoylphorbol-13-acetate and sodium butyrate, indicating that viral production induced by estrogen is not a cell lytic phenomenon. Our results suggest that intratumoral estrogen overproduced by aromatase could induce ZEBRA expression and EBV reactivation, contributing to the progression of NPC.

The Role of Epstein-Barr Virus in Modulating Key Tumor Suppressor Genes in Associated Malignancies: Epigenetics, Transcriptional, and Post-Translational Modifications

Epstein-Barr virus (EBV) is ubiquitous and carried by approximately 90% of the world’s adult population. Several mechanisms and pathways have been proposed as to how EBV facilitates the pathogenesis and progression of malignancies, such as Hodgkin’s lymphoma, Burkitt’s lymphoma, nasopharyngeal carcinoma, and gastric cancers, the majority of which have been linked to viral proteins that are expressed upon infection including latent membrane proteins (LMPs) and Epstein-Barr virus nuclear antigens (EBNAs). EBV expresses microRNAs that facilitate the progression of some cancers. Mostly, EBV induces epigenetic silencing of tumor suppressor genes, degradation of tumor suppressor mRNA transcripts, post-translational modification, and inactivation of tumor suppressor proteins. This review summarizes the mechanisms by which EBV modulates different tumor suppressors at the molecular and cellular levels in associated cancers. Briefly, EBV gene products upregulate DNA methylases to induce epigenetic silencing of tumor suppressor genes via hypermethylation. MicroRNAs expressed by EBV are also involved in the direct targeting of tumor suppressor genes for degradation, and other EBV gene products directly bind to tumor suppressor proteins to inactivate them. All these processes result in downregulation and impaired function of tumor suppressors, ultimately promoting malignances.

Absence of bovine leukemia virus in the buffy coats of breast cancer cases from Alabama, USA

Breast cancer is reported as one of the most common and deadly cancers among females. Recent findings have suggested that bovine leukemia virus (BLV), a highly prevalent bovine virus worldwide, might be linked to human breast cancer. However, the involvement of BLV as a risk factor for breast cancer remains controversial. In this study, BLV FRET-PCR was carried out on 238 blood-derived DNA samples from breast cancer patients from the Alabama Hereditary Cancer Cohort. In addition, randomly selected samples (n = 20) were evaluated by WGS for the presence of BLV genome. No BLV proviral DNA was detected in any of 238 samples assayed by FRET-qPCR in this study. Similarly, the WGS analysis did not detect the presence of the BLV genome in the DNA of the buffy coats from 20 randomly selected patients with breast cancer. This study did not support the findings of suggesting an association between BLV and breast cancer. Notably, nearly all the studies using in situ PCR and immunohistochemistry demonstrated positive associations while other studies using whole-genome sequencing and other methods failed to identify the BLV association with breast cancer. Further studies including all reported BLV detection techniques/methods on the same breast cancer sample sets would appear to be the most likely way of resolving the current contradictory evidence.

Molecular Properties and Therapeutic Targeting of the EBV-Encoded Receptor BILF1

The γ-herpesvirus Epstein-Barr Virus (EBV) establishes lifelong infections in approximately 90% of adults worldwide. Up to 1,000,000 people yearly are estimated to suffer from health conditions attributed to the infection with this virus, such as nasopharyngeal and gastric carcinomas as well as several forms of B, T and NK cell lymphoma. To date, no EBV-specific therapeutic option has reached the market, greatly reducing the survival prognoses of affected patients. Similar to other herpesviruses, EBV encodes for a G protein-coupled receptor (GPCR), BILF1, affecting a multitude of cellular signaling pathways. BILF1 has been identified to promote immune evasion and tumorigenesis, effectively ensuring a life-long persistence of EBV in, and driving detrimental health conditions to its host. This review summarizes the epidemiology of EBV-associated malignancies, their current standard-of-care, EBV-specific therapeutics in development, GPCRs and their druggability, and most importantly consolidates the findings of over 15 years of research on BILF1 in the context of EBV-specific drug development. Taken together, BILF1 constitutes a promising target for the development of novel EBV-specific therapeutics.

MiRNA-218 Is Frequently Downregulated in Malignant Breast Tumors: A Footprint of Epstein-Barr Virus Infection

BACKGROUND & OBJECTIVE

The role of Epstein-Barr Virus in development of breast cancer is frequently studied. In this regard, miRNAs are among the contributing elements in the molecular pathophysiology of EBV-related diseases. In addition, a growing number of host miRNAs are believed to be implicated in pathogenesis of breast cancer. MiR-218 is a tumor suppressive miRNA that is subjected to dysregulation in various EBV-associated cancers. We aimed to investigate the frequency of EBV and its relationship with expression status of tumor suppressive miR-218 in breast cancer and adjacent normal tissue.

METHODS

A total number of 51 fresh malignant breast cancer tissues (cases) and their adjacent normal tissues (controls) were collected. Nested-PCR and RT-qPCR were set to identify EBV frequency and miR-218 expression in cases and controls, respectively.

RESULTS

Out of all samples, 6.8% (7/102) comprising 11.6% (6/51) in malignant tissues and 1.9% (1/51) in normal control tissues were positive for EBV (P<0.05). Quantitative data showed that miR-218 was significantly downregulated in malignant tissues compared to control tissues (P<0.0001). In addition, reduced expression of miR-218 was associated with adverse clinical outcomes, metastasis, and higher grades of malignancy. Given the presence of EBV, lower expression of miR-218 was observed in breast cancer group in comparison with normal group (P<0.05).

CONCLUSION

Our results raise the possibility of the relation between EBV infection and miR-218 downregulation in breast cancer and propose further investigations in this regard.

Haploinsufficiency Interactions between RALBP1 and p53 in ERBB2 and PyVT Models of Mouse Mammary Carcinogenesis

Simple Summary

Rlip knockout has been reported to prevent cancer in highly cancer-susceptible mice lacking p53, and Rlip knockdown kills many types of cancer cells. In humans, breast cancer shows diverse characteristics, including HER2-driven subtypes and viral-driven subtypes. HER2 can be targeted; however, escape of the cancer from targeted therapies remains a problem. In this work we evaluated the capacity of Rlip knockout to prevent breast cancer in genetically engineered mouse models of HER2-driven breast cancer (Erbb2 model) and polyomavirus-driven breast cancer (PyVT model). We found that in Erbb2 mice, Rlip knockout significantly delayed oncogenesis and reduced the expression of genes associated with poor prognosis in patients. In PyVT mice, Rlip knockout did not delay oncogenesis or tumor growth, but Rlip knockdown reduced tumor metastasis to the lung. We conclude that Rlip inhibitors may significantly improve survival in HER2-positive patients, but are unlikely to offer benefits to patients with polyomavirus-associated tumors.

Abstract

We recently reported that loss of one or both alleles of Ralbp1, which encodes the stress-protective protein RLIP76 (Rlip), exerts a strong dominant negative effect on both the inherent cancer susceptibility and the chemically inducible cancer susceptibility of mice lacking one or both alleles of the tumor suppressor p53. In this paper, we examined whether congenital Rlip deficiency could prevent genetically-driven breast cancer in two transgenic mouse models: the MMTV-PyVT model, which expresses the polyomavirus middle T antigen (PyVT) under control of the mouse mammary tumor virus promoter (MMTV) and the MMTV-Erbb2 model which expresses MMTV-driven erythroblastic leukemia viral oncogene homolog 2 (Erbb2, HER2/Neu) and frequently acquires p53 mutations. We found that loss of either one or two Rlip alleles had a suppressive effect on carcinogenesis in Erbb2 over-expressing mice. Interestingly, Rlip deficiency did not affect tumor growth but significantly reduced the lung metastatic burden of breast cancer in the viral PyVT model, which does not depend on either Ras or loss of p53. Furthermore, spontaneous tumors of MMTV-PyVT/Rlip+/+ mice showed no regression following Rlip knockdown. Finally, mice lacking one or both Rlip alleles differentially expressed markers for apoptotic signaling, proliferation, angiogenesis, and cell cycling in PyVT and Erbb2 breast tumors. Our results support the efficacy of Rlip depletion in suppressing p53 inactivated cancers, and our findings may yield novel methods for prevention or treatment of cancer in patients with HER2 mutations or tumor HER2 expression.

Interplay between Epstein-Barr virus infection and environmental xenobiotic exposure in cancer

Epstein-Barr virus (EBV) is a herpesvirus associated with lymphoid and epithelial malignancies. Both B cells and epithelial cells are susceptible and permissive to EBV infection. However, considering that 90% of the human population is persistently EBV-infected, with a minority of them developing cancer, additional factors are necessary for tumor development. Xenobiotics such as tobacco smoke (TS) components, pollutants, pesticides, and food chemicals have been suggested as cofactors involved in EBV-associated cancers. In this review, the suggested mechanisms by which xenobiotics cooperate with EBV for carcinogenesis are discussed. Additionally, a model is proposed in which xenobiotics, which promote oxidative stress (OS) and DNA damage, regulate EBV replication, promoting either the maintenance of viral genomes or lytic activation, ultimately leading to cancer. Interactions between EBV and xenobiotics represent an opportunity to identify mechanisms by which this virus is involved in carcinogenesis and may, in turn, suggest both prevention and control strategies for EBV-associated cancers.

Presence of HPV, EBV and HMTV Viruses Among Egyptian Breast Cancer Women: Molecular Detection and Clinical Relevance

Background

Oncogenic viruses, their possible association with breast cancer (BC) and effect on its clinical course are interesting issue. The present study evaluates the presence of human papillomavirus (HPV), EpsteinBarr virus (EBV), and human mammary tumor virus (HMTV) in BC and their relation with clinico-pathological characteristics.

Patients and Methods

This study was conducted on 80 Egyptian women with BC and 30 control women without known oncological disease. Forty formalin-fixed paraffin-embedded (FFPE) tissues, forty fresh tissue samples, and white blood cells (WBCs) of BC patients and WBCs of controls were subjected to a qualitative polymerase chain reaction (PCR). Quantitative real-time PCR was used to measure viral loads in fresh tissues of BC. The result was correlated with clinico-pathological characteristics of BC.

Results

HPV was detected in 33 (41.25%), EBV in 30 (37.5%) and HMTV in 33 (41.25%) BC patients. None of the control women was positive for HPV or EBV while HMTV was detected in 7 (23.3%). Among 40 BC WBCs specimens, HPV/HMTV were found together in 25%, followed by EBV/HMTV in 2.5% and EBV/HPV in 2.5%. However, the three viruses (HPV/EBV/HMTV) were found together in only 5%. In the 40 fresh BC tissues, the three viruses were found together in 12 (30%), EBV/HMTV in 7 (17.5%), HPV/HMTV in 4 (10%), and HPV/EBV in 4 (10%). EBV, HMTV, or multiple viral infections were associated with younger age of BC women. HPV, EBV, and HMTV median loads in fresh tissues were 4.8×10³ copies/μL, 6.3×10³ copies/μL, and 97 copies/μL, respectively.

Conclusion

WBCs could be a more suitable specimen instead of fresh tissue for HMTV detection in BC patients to avoid invasive procedures. The presence of HPV, EBV, and HMTV together in Egyptian women with BC was significantly associated with younger age.

Tumor-related Microbiome in the Breast Microenvironment and Breast Cancer

Despite the significant progress in diagnosis and treatment over the past years in the understanding of breast cancer pathophysiology, it remains one of the leading causes of mortality worldwide among females. Novel technologies are needed to improve better diagnostic and therapeutic approaches, and to better understand the role of tumor-environment microbiome players involved in the progression of this disease. The gut environment is enriched with over 100 trillion microorganisms, which participate in metabolic diseases, obesity, and inflammation, and influence the response to therapy. In addition to the direct metabolic effects of the gut microbiome, accumulating evidence has revealed that a microbiome also exists in the breast and in breast cancer tissue. This microbiome enriched in the breast environment and the tumor microenvironment may modulate effects potentially associated with carcinogenesis and therapeutic interventions in breast tissue, which to date have not been properly acknowledged. Herein, we review the most recent works associated with the population dynamics of breast microbes and explore the significance of the microbiome on diagnosis, tumor development, response to chemotherapy, endocrine therapy, and immunotherapy. To overcome the low reproducibility of evaluations of tumor-related microbiome, sequencing technical escalation and machine deep learning algorithms may be valid for standardization of assessment for breast-related microbiome and their applications as powerful biomarkers for prognosis and predictive response in the future.

High-risk human papillomaviruses and Epstein-Barr virus in breast cancer in Lebanese women and their association with tumor grade: a molecular and tissue microarray study

Background

High-risk human papillomaviruses (HPVs) are present and can cooperate with Epstein–Barr virus (EBV) to initiate and/or enhance the progression of several types of human carcinomas including cervical as well as head and neck; in parallel, it has been recently pointed out that these oncoviruses can be detected in human breast cancers. Thus, we herein explored the presence/co-presence of high-risk HPVs and EBV in breast cancer in Lebanese women.

Methods

A cohort of 102 breast cancer samples and 14 normal breast tissues were assessed for the presence of HPVs and EBV. Polymerase chain reaction (PCR) and immunohistochemistry (IHC) analysis in addition to tissue microarray (TMA) platform were used in this study.

Results

We found the presence of HPV in 66/102 (65%) of our samples, while EBV is present in 41/102 (40%) of the cohort. Additionally, our data showed that high-risk HPV types (52, 35, 58, 45, 16 and 51) are the most frequent in breast cancer in Lebanese women. Meanwhile, we report that high-risk HPVs and EBV are co-present in 30/102 (29%) of the samples; more significantly, our results indicate that their co-presence is associated with tumor grade (p = 0.03).

Conclusion

Our data revealed that HPVs and EBV are present/co-present in human breast cancer where they may play an important role in its development and/or progression; thus, we believe that further investigations are essential to confirm and elucidate the presence/co-presence of these oncoviruses and the underlying mechanisms of their interaction in breast carcinogenesis.

Human cytomegalovirus and Epstein-Barr virus infections in breast cancer: A molecular study on Iranian women

BACKGROUND AND OBJECTIVES

The role of human cytomegalovirus (HCMV) and Epstein-Barr virus (EBV) infections in breast cancer pathology is not well understood. Our study aimed to investigate the association of HCMV and EBV infections with breast cancer and distinguish the types of positive EBV and LMP-1 samples in Iranian patients.

METHODS

Seventy-two formalin-fixed paraffin-embedded (FFPE) breast cancer tissues were analyzed between December 2014 and April 2016. Samples were analyzed for HCMV and EBV using nested-PCR and conventional PCR assays, respectively. Statistical analysis was performed using SPSS software version 18.

RESULTS

Overall, HCMV and EBV genomes were detected in 6.9% and 16.7% of FFPE breast cancer tissues, respectively. Clinical factors were not statistically associated with the presence of HCMV and EBV.

CONCLUSION

In this study, we reported EBV and LMP-1 typing in breast carcinoma cases for the first time in Iran. Our findings indicate that HCMV and EBV infections are not associated with the development of breast cancer.

Influence of Childhood Adversity and Infection on Timing of Menarche in a Multiethnic Sample of Women

Childhood adversities (CAs) and infections may affect the timing of reproductive development. We examined the associations of indicators of CAs and exposure to tonsillitis and infectious mononucleosis (mono) with age at menarche. A multiethnic cohort of 400 women (ages 40–64 years) reported exposure to parental maltreatment and maladjustment during childhood and any diagnosis of tonsillitis and/or mono; infections primarily acquired in early life and adolescence, respectively. We used linear and relative risk regression models to examine the associations of indicators of CAs individually and cumulatively, and history of tonsillitis/mono with an average age at menarche and early onset of menarche (<12 years of age). In multivariable models, histories of mental illness in the household (RR = 1.44, 95% CI: 1.01–2.06), and tonsillitis diagnosis (RR = 1.67, 95% CI: 1.20–2.33) were associated with early menarche (<12 years), and with an earlier average age at menarche by 7.1 months (95% CI: −1.15, −0.02) and 8.8 months (95% CI: −1.26, −0.20), respectively. Other adversities indicators, cumulative adversities, and mono were not statistically associated with menarcheal timing. These findings provided some support for the growing evidence that early life experiences may influence the reproductive development in girls.

Virtual screening of the multi-gene regulatory molecular mechanism of Si-Wu-tang against non-triple-negative breast cancer based on network pharmacology combined with experimental validation

ETHNOPHARMACOLOGICAL RELEVANCE

Si-Wu-Tang (SWT), a prestigious herbal formula from China, has been extensively used for centuries for female-related diseases. It has been documented that SWT has a significant inhibitory effect on non-triple-negative breast cancer (non-TNBC) cells. However, there has been limited comprehensive analysis of the targeted effects of the anticancer components of SWT and its exact biological mechanism.

AIM OF THE STUDY

This study aims to uncover the mechanism by which SWT treats non-TNBC by applying a network pharmacological method combined with experimental validation.

MATERIALS AND METHODS

First, SWT compounds were collected from the Traditional Chinese Medicines Systems Pharmacology database (TCMSP) and The Encyclopedia of Traditional Chinese Medicine (ETCM), and then the targets related to SWT were obtained from the TCMSP and SwissTarget databases. Second, a target data set of non-TNBC proteins was established by using the Online Mendelian Inheritance in Man (OMIM), GeneCards and Gene Expression Omnibus (GEO) databases. Third, based on the overlap of targets between SWT and non-TNBC, a protein-protein interaction (PPI) network was built to analyse the interactions among these targets, which focused on screening for hub targets by topology. On these hub genes, we conducted a meta-analysis and survival analysis to screen the best match targets, ESR1, PPARG, CAT, and PTGS2, which had a strong correlation with the ingredients of SWT in our verification by molecular docking. In vitro experiments further proved the reliability of the network pharmacology findings. Finally, FunRich software and the ClusterProfiler package were utilized for the enrichment analysis of Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) data.

RESULTS

A total of 141 active ingredients and 116 targets of SWT were selected. GO enrichment analysis showed that the biological processes through which SWT acted against non-TNBC (FDR<0.01) mainly involved modulating energy metabolism and apoptosis. According to RT-qPCR and Western blotting, the mRNA and protein expression of ESR1, PPARG and PTGS2 were upregulated (P < 0.01), and the mRNA and protein levels of CAT were downregulated (P < 0.01), suggesting a multi-gene regulatory molecular mechanism of SWT against non-triple-negative breast cancer.

CONCLUSIONS

This research explored the multi-gene pharmacological mechanism of action of SWT against non-TNBC through network pharmacology and in vitro experiments. The findings provide new ideas for research on the mechanism of action of Chinese medicine against breast cancer.

High Seroprevalence of Hepatitis C Virus Antibody in Breast Cancer Patients in Egypt

Background:

Hepatitis C virus (HCV) is a known risk factor for hepatocellular carcinoma. Several epidemiological studies have pointed out to an association of HCV infection with other extrahepatic malignancies. The role of chronic HCV in breast cancer causation is less clear. Egypt is an endemic area of HCV infection with resulting significant morbidity. The association between HCV status and breast cancer risk in Egyptian women is hitherto unknown.

Methods:

A retrospective study was performed. The prevalence of anti-HCV seropositivity was estimated in a sample of women with a breast cancer diagnosis, retrieved from the hospital records, and was compared to the raw data of a population study in Egypt. Anti-HCV negative and positive patients were compared regarding the disease course and outcome.

Results:

Retrospective analysis revealed a markedly high prevalence of anti-HCV seropositivity in young breast cancer patients. In patients younger than 45 years, 13.4% were anti-HCV positive. Seropositivity was 6-fold higher in these patients than in adult females of the same age without cancer diagnosis (P = .003). The biological type, tumor size, nodal status, and disease-free survival were not affected by the patients’ HCV status.

Conclusion:

Young Egyptian breast cancer patients have a dramatically high prevalence of HCV seropositivity. Further population studies are strongly required to investigate the epidemiological association of these two significant health problems.

Downregulation of miR-143/145 Cluster in Breast Carcinoma Specimens: Putative Role of DNA Oncoviruses

Background: The DNA oncoviruses, including human papillomavirus (HPV) and Epstein-Barr virus (EBV) are among the most important infectious agents involved in breast carcinogenesis. These oncoviruses have a broad disrupting effect on cellular miRNAs and their functions, by which they contribute to carcinogenesis. Objectives: In this investigation, we evaluated the correlation between HPV and EBV and the expression level of tumor suppressor miRNAs (miR-143 and 145), clinical outcomes, and their association with stimulating inflammatory cytokines in patients with breast carcinoma. Methods: In our case-control study, 35 cancerous tissues and 35 adjacent non-cancerous tissues were collected from 35 patients. Nested-PCR was set up for the detection of HPV and EBV genomes, and RT-qPCR was used for miRNA expression in the case and control groups. In addition, serum specimens were obtained from all patients (n = 35) and healthy controls (n = 35) to determine the IL-8 serum concentration. Results: We found HPV and EBV in 14.2% (10/70) and 7% (5/70) of all samples, respectively. The distributions of positive samples in the case and control groups were 25.7% (9/35) and 2.9% (1/35) (P = 0.006) for HPV and 11.4% (4/35) and 2.9% (1/35) (P = 0.164) for EBV, respectively. Besides, RT-qPCR showed that miR-143 and miR-145 were significantly downregulated in HPV and EBV-infected cases compared to non-infected ones (P < 0.05). Data also indicated that the promotion of metastasis status was related to miR-143/145 downregulation and HPV infection (P = 0.003). No significant difference was found in serum IL-8 concentration concerning viral infections. Conclusions: Our results suggested the possible involvement of viral infections in breast carcinogenesis and adverse clinical outcomes by downregulating miR-143/145.

Is EBV Associated with Breast Cancer in Specific Geographic Locations?

Epstein-Barr virus (EBV) is a virus that establishes a life-long infection in people, and infection with EBV is nearly ubiquitous by adulthood. EBV was identified from biopsy material from a child with Burkitt's lymphoma (BL) in sub-Saharan Africa. EBV has a well-characterised role in the development of some cancers, notably, Burkitt's lymphoma (BL), Hodgkin's disease (HD), gastric carcinoma (GC), and nasopharyngeal carcinoma (NPC). Links have also been made between EBV and breast cancer (BC), but these have been controversial. For all EBV-associated cancers, the ubiquitous nature of infection with EBV, contrasted with the relatively rare development of cancer, highlights a problem of determining whether EBV is an aetiological agent of cancer. In addition, the geographic distributions of some EBV-associated cancers point to contributions from additional co-factors. Recent meta-analyses of the incidence of EBV within BC biopsies has revealed that the diversity in the conclusions remain, however, they also show more of an association between EBV and BC biopsies in some study locations. Here, we review the evidence linking EBV with BC, and conclude that the evidence for the presence of EBV in BC biopsies is concentrated in specific geographic regions but is currently insufficient to provide a causal link. We pose some questions that could help to resolve the question of whether EBV contributes to BC and probe the contribution EBV might make to the aetiology of BC.

Targeting the signaling in Epstein-Barr virus-associated diseases: mechanism, regulation, and clinical study

Epstein–Barr virus-associated diseases are important global health concerns. As a group I carcinogen, EBV accounts for 1.5% of human malignances, including both epithelial- and lymphatic-originated tumors. Moreover, EBV plays an etiological and pathogenic role in a number of non-neoplastic diseases, and is even involved in multiple autoimmune diseases (SADs). In this review, we summarize and discuss some recent exciting discoveries in EBV research area, which including DNA methylation alterations, metabolic reprogramming, the changes of mitochondria and ubiquitin-proteasome system (UPS), oxidative stress and EBV lytic reactivation, variations in non-coding RNA (ncRNA), radiochemotherapy and immunotherapy. Understanding and learning from this advancement will further confirm the far-reaching and future value of therapeutic strategies in EBV-associated diseases.

The Emerging Roles of π Subunit-Containing GABAA Receptors in Different Cancers

Cancer is one of the leading causes of death in both developed and developing countries. Due to its heterogenous nature, it occurs in various regions of the body and often goes undetected until later stages of disease progression. Feasible treatment options are limited because of the invasive nature of cancer and often result in detrimental side-effects and poor survival rates. Therefore, recent studies have attempted to identify aberrant expression levels of previously undiscovered proteins in cancer, with the hope of developing better diagnostic tools and pharmaceutical options. One class of such targets is the π-subunit-containing γ-aminobutyric acid type A receptors. Although these receptors were discovered more than 20 years ago, there is limited information available. They possess atypical functional properties and are expressed in several non-neuronal tissues. Prior studies have highlighted the role of these receptors in the female reproductive system. New research focusing on the higher expression levels of these receptors in ovarian, breast, gastric, cervical, and pancreatic cancers, their physiological function in healthy individuals, and their pro-tumorigenic effects in these cancer types is reviewed here.

The co-presence of high-risk human papillomaviruses and Epstein-Barr virus is linked with tumor grade and stage in Qatari women with breast cancer

High-risk human papillomaviruses (HPV) can be present and cooperate with Epstein–Barr virus (EBV) to promote the onset and/or progression of various cancers including cervical, breast, head and neck as well as colorectal. In this investigation, we explored the co-prevalence of high-risk HPV and EBV in 74 breast cancer tissues from Qatari women using polymerase chain reaction. We found that high-risk HPV and EBV are present in 48/74 (65%) and 36/74 (49%) of the cases, respectively. While we noted that the presence of HPV presence is associated with triple-negative breast cancer (TNBC) (p = .008), however, the presence of EBV did not correlate with any breast cancer subgroup. Moreover, our data revealed that high-risk HPV and EBV are co-present in 35/74 (47%) of the samples and their co-presence is significantly associated with tumor grade (p = .04) and tumor stage (p = .04). These data indicate that HPV and EBV are commonly co-present in breast cancer and their association could be linked with a more aggressive tumor phenotype. Thus, further investigations are essential to understand the underlying mechanisms of HPV and EBV cooperation in breast carcinogenesis.

Bovine Leukemia virus (BLV) and risk of breast cancer: a systematic review and meta-analysis of case-control studies

Background

Breast cancer is reported as one of the most common cancers among females worldwide. Infectious agents especially viruses have been considered as role players in the development of breast cancer. Although some investigations suggest an association between bovine leukemia virus (BLV) and breast cancer, the involvement of this virus as a risk factor remains controversial. The present study aimed to find out any possible association between BLV and breast cancer through conducting a systematic review and meta-analysis.

Methods

Systematic literature search was performed by finding related case-control articles from the PubMed, Google Scholar, Web of Science, Scopus, and EMBASE databases. The heterogeneity and the multivariable-adjusted OR and corresponding 95% CI were applied by meta-analysis and forest plot across studies. All statistical analyses were performed using Stata 14.1.

Result

Based on a comprehensive literature search, 9 case-control studies were included for meta-analysis. The combination of all included studies showed that BLV infection is associated with an increased risk of breast cancer [summary OR (95% CI) 2.57 (1.45, 4.56)].

Conclusion

This is the first meta-analysis to analyze a potential association between BLV infection and the risk of breast cancer. Control of the infection in cattle herds and screening of the milk and dairy products may help to reduce the transmission of the virus to humans.

Clinicopathological Significance of EBV-Infected Gastric Carcinomas: A Meta-Analysis

Background and objectives: The present study aims to elucidate the clinicopathologic significance of Epstein-Barr virus (EBV) infection in gastric carcinomas (GCs) through a meta-analysis. Materials and Methods: Sixty-one eligible studies were included in the present meta-analysis. The included patients, with and without EBV infection, were 2063 and 17,684, respectively. We investigated the clinicopathologic characteristics and various biomarkers, including programmed death-ligand 1 (PD-L1) expression and tumor-infiltrating lymphocytes (TILs). Results: The estimated EBV-infected rate of GCs was 0.113 (95% confidence interval (CI): 0.088-0.143). The EBV infection rates in GC cells were 0.138 (95% CI: 0.096-0.194), 0.103 (95% CI: 0.077-0.137), 0.080 (95% CI: 0.061-0.106), and 0.042 (95% CI: 0.016-0.106) in the population of Asia, America, Europe, and Africa, respectively. There was a significant difference between EBV-infected and noninfected GCs in the male: female ratio, but not other clinicopathological characteristics. EBV infection rates were higher in GC with lymphoid stroma (0.573, 95% CI: 0.428-0.706) than other histologic types of GCs. There were significant differences in high AT-rich interactive domain-containing protein 1A (ARID1A) and PD-L1 expressions, and high CD8+ TILs between EBV-infected and noninfected GCs. Conclusions: Our results showed that EBV infection of GCs was frequently found in male patients and GCs with lymphoid stroma. EBV infection was significantly correlated with ARID1A and PD-L1 expressions and CD8+ TILs in GCs.

Long Non-Coding RNA HULC Promotes the Development of Breast Cancer Through Regulating LYPD1 Expression by Sponging miR-6754-5p

Introduction

Long non-coding RNAs (lncRNAs) were found to regulate many biological processes including cancer development, immunology and other diseases. LncRNA HULC was found to be oncogenes in many cancer progression. However, the role of HULC in the regulation of breast cancer remains unclear.

Methods

The expression of HULC and miR-6754-5p was examined by RT-PCR. Through knockdown of HULC, we found that the proliferation abilities coupled with migration and invasion abilities were significantly decreased. And also, we verified that overexpression of miR-6754-5p significantly decreased the proliferation ability of breast cancer cells.

Results

In this study, we found that lncRNA HULC was overexpressed in breast cancer tissues and cell lines compared to normal healthy breast tissues and normal breast cell line. Moreover, the high expression of HULC was associated with metastasis and malignancy of breast cancers. Mechanically, we found that HULC can bind to miR-6754-5p directly through complementary base pairing. Furthermore, we found that HULC regulates the expression of LYPD1 through sponging miR-6754-5p. Moreover, overexpression of LYPD1 can rescue the migration and invasion abilities of breast cancer cells decreased by knockdown of HULC or overexpression of miR-6754-5p.

Conclusion

Our study showed the role of HULC in promoting breast cancer development and explained the detailed molecular mechanisms.