Preliminary screening reveals HPV-derived cDNA in the HNCF-PI 52 cell line originally derived from normal cervical...

Human papillomavirus (HPV) is implicated in multiple malignancies and can persist as unrecognized contaminant in cell cultures derived from both normal and neoplastic tissues. This preliminary screening study evaluated the presence of HPV-derived DNA and cDNA in two cell lines: A2780, established from ovarian carcinoma, and HNCF-PI 52, derived from histologically normal cervical tissue. Genomic DNA and total RNA were extracted from both lines. To eliminate residual genomic DNA, RNA samples were treated with DNase prior to cDNA synthesis. PCR using GP5⁺/GP6⁺ universal primers targeting the conserved L1 region was performed on DNA. Nested RT-PCR using CP65/CP70 and CP66/CP69 primer sets was conducted on cDNA to detect mucosal HPV-derived related sequences. CaSki cells served as the positive control. No HPV DNA was detected in the A2780 ovarian cancer cell line. In contrast, HNCF-PI 52 exhibited a distinct band of the expected ∼150 bp in the L1 region. Nested PCR on cDNA produced amplicons between 374 and 389 bp in both HNCF-PI 52 and CaSki cells, while A2780 remained consistently negative throughout all amplifications. The amplicon size observed in HNCF-PI 52 was consistent with mucosal HPV-related sequences. These results indicate the presence of previously unrecognized viral cDNA in the HNCF-PI 52 cell line, originally believed to be HPV-negative. The absence of reverse transcriptase-negative controls, definitive typing by sequencing, and independent cell line authentication represent limitations of this screening. This report is therefore presented as a preliminary observation rather than a molecular validation. The finding reinforces the importance of routine viral screening and authentication of research cell lines, particularly those originating from cervical tissues, to prevent the inadvertent use of unknowingly contaminated models in biomedical research.