AUTHOR=Zheng Hua-chuan , E Ying , Cui Zheng-guo , Zhao Shuang , Zhang Yong 

TITLE=The Oncogenic Roles of JC Virus T Antigen in Breast Carcinogenesis

JOURNAL=Frontiers in Molecular Biosciences

VOLUME=8

YEAR=2021

URL=https://www.frontiersin.org/journals/molecular-biosciences/articles/10.3389/fmolb.2021.687444

DOI=10.3389/fmolb.2021.687444

ISSN=2296-889X

ABSTRACT=<p><bold>Purpose:</bold> JC virus (JCV) infects 80–90% of the population and results in progressive multifocal leukoencephalopathy upon immunodeficiency. The study aimed to pathologically clarify the oncogenic roles of T antigen in human breast cancers.</p><p><bold>Methods:</bold> Breast cancer, dysplasia, and normal tissues were examined for <italic>T antigen</italic> of JCV by nested and real-time PCR. The positive rate or copy number of T antigen was compared with clinicopathological parameters of breast cancer. JCV existence was morphologically detected by immunohistochemistry and <italic>in situ</italic> PCR. T antigen was examined by Western blot using frozen samples of breast cancer and paired normal tissues.</p><p><bold>Results:</bold> According to nested PCR, the positive rate of breast ductal or lobular carcinoma was lower than that of normal tissue (<italic>p</italic> &lt; 0.05). T antigen existence was negatively correlated with E-cadherin expression and triple-negative breast cancer (<italic>p</italic> &lt; 0.05), but positively correlated with lymph node metastasis and estrogen receptor and progestogen receptor expression (<italic>p</italic> &lt; 0.05). Quantitative PCR showed that JCV copies were gradually decreased from normal, dysplasia to cancer tissues (<italic>p</italic> &lt; 0.05). JCV T antigen copy number was lower in ductal adenocarcinoma than in normal tissue (<italic>p</italic> &lt; 0.05), in line with in situ PCR and immunohistochemistry. JCV copies were negatively correlated with tumor size and E-cadherin expression (<italic>p</italic> &lt; 0.05), but positively correlated with G grading of breast cancer (<italic>p</italic> &lt; 0.05). Western blot also indicated weaker T antigen expression in breast cancer than normal tissues (<italic>p</italic> &lt; 0.05).</p><p><bold>Conclusion:</bold> JCV T antigen might play an important role in breast carcinogenesis. It can be employed as a molecular marker for the differentiation and aggressive behaviors of breast cancer.</p>