Insertional oncogenesis by HPV70 revealed by multiple genomic analyses in a clinically HPV-negative cervical cancer

Abstract

Cervical carcinogenesis, the second leading cause of cancer death in women worldwide, is caused by multiple types of human papillomaviruses (HPVs). To investigate a possible role for HPV in a cervical carcinoma that was HPV-negative by PCR testing, we performed HPV DNA hybridization capture plus massively parallel sequencing. This detected a subgenomic, URR- E6-E7-E1 segment of HPV70 DNA, a type not generally associated with cervical cancer, inserted in an intron of the B-cell lymphoma/leukemia 11B (BCL11B) gene in the human genome. Long range DNA sequencing confirmed the virus and flanking BCL11B DNA structures including both insertion junctions. Global transcriptomic analysis detected multiple, alternatively spliced, HPV70-BCL11B, fusion transcripts with fused open reading frames. The insertion and fusion transcripts were present in an intraepithelial precursor phase of tumorigenesis. These results suggest oncogenicity of HPV70, identify novel BCL11B variants with potential oncogenic implications, and underscore the advantages of thorough genomic analyses to elucidate insights into HPV-associated tumorigenesis.\n\nStatement of SignificanceMultiple HPV types have been defined as high risk for cancer causation. However, genomic analyses applied here detected a non-high risk HPV in a carcinoma that was HPV negative, and elucidated virally-associated tumorigenic genetic events. This stresses the importance of thorough genomic analyses for elucidating genetic processes in HPV-associated tumorigenesis.\n\nAuthor SummaryCervical cancer is the second leading cause of cancer death in women worldwide. Most cervical cancers are caused by one of 15 high risk types of human papilloma viruses (HPVs), although hundreds of types of HPVs exist. We used a series of contemporary genomics analyses to examine a cervical cancer that was clinically determined to be HPV-negative. These detected DNA of HPV70, an HPV type not considered to be high risk, in the tumor. Approximately half of the HPV70 DNA genome was present including the viral E6 and E7 oncogenes. Moreover, the viral DNA was inserted into the BCL11B gene in the human genome. BCL11B is known to be mutated in certain human cancers. The HPV70 DNA interacted with the human BCL11B gene to produce altered forms of RNA encoding unusual, truncated forms of the BCL11B protein. These results strongly implicate HPV70 as being oncogenic, suggest that this tumor was caused by a combination of viral oncogenes plus the virally-activated human BCL11B gene, demonstrate novel truncated BCL11B variants with oncogenic implications, and underscore the advantages of thorough genomic analyses to elucidate HPV tumorigenesis insights