Is the HPV virus responsible for the development of breast cancer?

High rate of high-risk human papillomavirus among benign and breast cancer patients in Ethiopia

INTRODUCTION

There have been numerous studies that showed the presence of human papillomavirus (HPV) in breast cancer; nonetheless, there is ongoing debate regarding their association. Given few studies in Ethiopia, we aimed to investigate the magnitude of HPV infection in Ethiopian breast cancer patients.

METHODS

A total of 120 formalin-fixed paraffin-embedded (FFPE) tissue blocks were obtained, and basic demographic, clinical, and histological data were collected from medical records. DNA was extracted from archived FFPE breast tissue specimens using GeneRead DNA FFPE Kit. The AnyplexTM II HPV28 Detection Kit (Seegene, Korea) was used to detect HPV by following the manufacturer's instructions. The SPSS Version 25 was used to enter and analyze data.

RESULTS

Among the 120 study participants; HPV (both high-risk and low-risk) was detected in 20.6% of breast cancer and 29.6% of non-malignant breast tumors. The most common genotype was the high-risk HPV 16 genotype. The frequency of HPV was nearly 10-fold higher in estrogen receptor-positive than ER-negative breast cancer. The percentage of HPV in the luminal (luminal A and luminal B) breast cancer subtypes was also much higher than in the non-luminal subtypes (HER-2 enriched and triple-negative breast cancer).

CONCLUSION

This study did not find a significant difference in HPV expression between breast cancer and non-malignant breast tumors; however, the higher percentage of HPV in ER-positive compared to ER-negative breast cancer warrants further attention.

Differential epigenetic and transcriptional profile in MCF-7 breast cancer cells exposed to cadmium

Cadmium (Cd) has been confirmed to be associated with breast carcinogenesis, but the mechanism was not clarified yet. Given that epigenetic modification was speculated as underlying mechanism, we examined the differential epigenome caused by Cd in breast cancer cells. Profiles of DNA methylation, microRNA (miRNA), long non-coding RNA (lncRNA), and message RNA (mRNA) were derived from Cd-treated and untreated MCF-7 breast cancer cells by microarray. We identified 997 target genes epigenetically regulated by Cd through cross-verification with the differential epigenome and transcriptome, and 400 of them were further validated in a breast cancer cohort. Biological function analyses suggested that several pathways were involved in Cd-induced breast carcinogenesis, such as Wnt signaling, metabolism, and human papilloma virus (HPV) infection. TXNRD1 and CCT3 were further identified as the critical genes based on the degree of expression change, hazard ratio difference, and connectivity. The present study revealed that Cd epigenetically regulated several pathways involving in breast carcinogenesis, particularly the Wnt signaling and metabolic pathways, among which TXNRD1 and CCT3 might play critical roles. It was also suggested that Cd and HPV infection might jointly participate in breast tumorigenesis.