In Vivo and In Vitro Studies Suggest a Possible Involvement of HPV Infection in the Early Stage of Breast Carcinogenesis via APOBEC3B Induction

High prevalence of infection with high-risk human papilloma virus (HPV) ranging from 25 to 100% (average 31%) was observed in breast cancer (BC) patients in Singapore using novel DNA chip technology. Early stage of BC demonstrated higher HPV positivity, and BC positive for estrogen receptor (ER) showed significantly higher HPV infection rate. This unique association of HPV with BC in vivo prompted us to investigate a possible involvement of HPV in early stages of breast carcinogenesis. Using normal breast epithelial cells stably transfected with HPV-18, we showed apparent upregulation of mRNA for the cytidine deaminase, APOBEC3B (A3B) which is reported to be a source of mutations in BC. HPV-induced A3B overexpression caused significant γH2AX focus formation, and DNA breaks which were cancelled by shRNA to HPV18 E6, E7 and A3B. These results strongly suggest an active involvement of HPV in the early stage of BC carcinogenesis via A3B induction

Effect of magnetic nanoparticles on apoptosis and cell cycle induced by wogonin in Raji cells

Traditional Chinese medicine is gradually becoming a new source of anticancer drugs. One such example is wogonin, which is cytotoxic to various cancer cell lines in vitro. However, due to its low water solubility, wogonin is restricted to clinical administration. Recently, the application of drug-coated magnetic nanoparticles (MNPs) to increase water solubility of the drug and to enhance its chemotherapeutic efficiency has attracted much attention. In this study, wogonin was conjugated with the drug delivery system of MNPs by mechanical absorption polymerization to fabricate wogonin-loaded MNPs. It was demonstrated that MNPs could strengthen wogonin-induced cell inhibition, apoptosis, and cell cycle arrest in Raji cells by methylthiazol tetrazolium assay, flow cytometer assay, and nuclear 4′,6-diamidino-2-phenylindole staining. Furthermore, the molecular mechanisms of these phenomena were explored by western blot, in which the protein levels of caspase 8 and caspase 3 were increased significantly while those of survivin and cyclin E were decreased significantly in wogonin-MNPs group. These findings suggest that the combination of wogonin and MNPs provides a promising strategy for lymphoma therapy

Epitope-directed monoclonal antibody production using a mixed antigen cocktail facilitates antibody characterization and validation

10.1038/s42003-021-01965-xCOMMUNICATIONS BIOLOGY4

Epitope-directed monoclonal antibody production using a mixed antigen cocktail facilitates antibody characterization and validation (vol 6, 441, 2021)

10.1038/s42003-021-02091-4COMMUNICATIONS BIOLOGY4

Relationship between HPV status and patholological features.

<p>Numbers at the bottom of each bar represent (number of HPV-positives)/(total sample numbers). Difference of HPV prevalence between invasive ductal carcinoma (IDC) and invasive LC (ILC) was statistically significant (<i>p</i> = 0.0003). IS; in situ.</p

A3B activation by HPV infection increases genome instability.

<p>(a) γH2AX immunofluorescence. Cells were fixed by 4% paraformaldehyde followed by staining of γH2AX protein and nuclear using anti- γH2AX Ab and DAPI respectively. (b) γH2AX western blot. Cells were lysed and subjected to western blot. The γH2AX and β-actin were detected using anti- γH2AX and β-actin Ab. (c) Comet assay. Cells were seeded onto agarose-coated slide glass after mixing with 1.5% agarose followed by lysis. Slides were subjected to electrophoresis and then genomic DNA was stained by PI. (d) Statistical analysis for panel C. Student’s t-test was performed, with <i>p</i>-values indicated on the graph.</p

Correlation of A3B expression level and HPV infection in BC patients.

<p>Total RNA from BC patients were obtained from NUHS TR. Samples were subjected to quantitative RT-PCR (qRT-PCR). The data of A3B (a) and A3G (b) were shown after normalization by GAPDH mRNA level. The number at the bottom of graph indicates the number of patients. Patient 1–11 are HPV-negative, patient 12–23 are HPV-positive.</p