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SDIRSACR Oncology Insights

SESSION 7

ADVANCEMENTS IN MOLECULAR DIAGNOSTICS AND CANCER BIOMARKERS IN ONCOLOGY

P34

Beyond coding sequences: the role of the long non-coding RNA NBAT1 in HPV-positive cancer samples
and cell lines

Franciska Rohlik1, Josipa Skelin2

1Faculty of Food Technology and Biotechnology, University of Zagreb, Zagreb, Croatia
2Department of Molecular Medicine, Rudjer Boskovic Institute, Zagreb, Croatia

Keywords: HPV, lncRNA, oncoproteins

Backround: Long non-coding RNAs (lncRNAs) are RNA transcripts longer than 200 nucleotides that, despite lacking
coding potential, regulate diverse biological processes, including epigenetic modifications, transcription, and translation.
The human genome contains approximately 15,000 lncRNA genes, with most of their functions still unknown. Recent
studies have highlighted their involvement in pathological states, particularly in cancer. HPV oncoproteins E6 and E7
are known to alter the expression of over 1,400 lncRNAs, although the biological significance of many of them remains
unclear. This study aimed to investigate the role of selected lncRNAs in HPV-associated head and neck malignancies,
comparing them with cervical samples to determine whether HPV's effects are site-specific or universal.
Materials and methods: Based on literature and database searches, lncRNAs interacting with proteins implicated in
HPV-driven carcinogenesis (MMP7, CDH1, GLI1, and KRT18) were identified, leading to the selection of five lncRNAs
(FEZF1-AS1, FUNDC2P4, GAS5, FOXCUT, and NBAT1) for further analysis. Total RNA was extracted from tumor samples
and cell lines and analyzed via RT-PCR.
Results: NBAT1 emerged as the most promising candidate, showing increased expression with higher tumor grade in
head and neck cancers and significantly lower expression in HPV-positive tumors (p = 0.05). Due to the limited number
of cervical lesion samples, no clear trend was observed in that group. Additional analyses in HPV+ and HPV- cell lines
revealed no statistically significant differences in NBAT1 expression, although HPV- cervical cancer cells (C33A) showed
a trend toward higher expression. A plasmid encoding NBAT1 was used to transfect various cell lines, and functional
assays indicated that NBAT1 overexpression affected cell proliferation and migration. Finally, neither silencing of HPV16
and HPV18 E6/E7 in HeLa and CaSki cells nor overexpression of these oncoproteins in C33A cells significantly altered
NBAT1 levels, suggesting that its expression is regulated by alternative mechanisms.
Conclusions: These findings position NBAT1 as a potential biomarker in HPV-related head and neck cancers and support
further investigation into its role in HPV-independent tumor progression.

Acknowledgments and funding: This project was funded through the European Union Next generation plan.

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