784P - HPV integration promotes HPV carcinogenesis via remodeling chromatin interactions between universal stripe factors and super-enhancer in HPV-related carcinoma

Background

The incidence of HPV integration is increased during the disease progression from precancerous lesions to carcinoma, and HPV integration is reputed as a key effect to escape eliminations from the host cells. Although HPV integration is identified in HPV-related carcinoma, the mechanisms underlying HPV carcinogenesis remain unclear.

Methods

Here, 6768 HPV integration sites from cervical carcinoma (CESC) and 470 from head & neck carcinoma (HNSC), high-through chromosome conformation capture (Hi-C), ChIP-seq, ChIP-PCR and RNA-seq were analyzed to identify the HPV integration characteristics in HPV-host interactions. Manual HPV-integration cells, an HPV integration mouse model (K14-HPV, FVB/N), and CRISPR-Cas9 knock-out cells were performed to demonstrate the chromatin remolding between universal stripe factors (USFs) and super-enhancers.

Results

In CESC and HNSC, USF motifs were enriched in HPV integration sites and integrated HPV-host interaction regions. In addition, HPV integration sites and integrated HPV-host interaction regions marked increased chromatin accessibility (ATAC-seq) and super-enhancer elements (H3K27ac, H3K4me1, and H3K4me3), with USF motifs enrichment in these regions. By dividing the tumor samples according to HPV status, USF genes were found to be upregulated in CESC and HNSC, which could be validated by tumor samples, manual HPV-integration cells, and the K14-HPV integration mouse model. Furthermore, three-dimensional chromatin analyses reveal the chromatin interactions between USF genes and super enhancers in tumor cells. The expression patterns of USF genes and chromatin interactions between USF genes and the super-enhancer were reversed via super-enhancer CRISPR-Cas9 knock-out, thus reversing malignant phenotypes of tumor cells in vitro and in vivo.

Conclusions

Overall, we identify that HPV integration remodels chromatin interactions between USFs and super enhancers to promote malignant phenotypes in HPV-related carcinoma, which provides insight into the three-dimensional mechanism in HPV-related carcinogenesis.

Clinical trial identification

Editorial acknowledgement

Legal entity responsible for the study

C. CAO.

Funding

National Key R&D Program of China (21YFC2701201) and the National Natural Science Foundation of China (82072895, 82141106, and 82203453).

Disclosure

All authors have declared no conflicts of interest.