Cervical cancer remains a global health burden, with persistent infection by high-risk human papillomaviruses (HR-HPVs) being the primary etiological factor. HR-HPVs target stem-like cells of the cervical epithelium to establish chronic infections. Upon infection of the cervical transformation zone (TZ)—a region adjacent to the squamocolumnar junction (SCJ)—these viruses drive neoplastic transformation, which is due in part to the unique cellular composition and hormonal responsiveness of the TZ. Reserve cells, which can accumulate at the cervical crypt entrances of the TZ, are thought to be highly susceptible to HR-HPV infection because of their location beneath a single layer of columnar cells. Infection of the stratified ectocervical epithelium, in contrast, requires a wound to allow basal cell infection, replication, and the expression of early genes to adjust epithelial homeostasis while facilitating immune evasion. Persistent infection by HR-HPV types, particularly HPV16 and HPV18, can result in the deregulated expression of viral genes E6 and E7, driving cell cycle disruption, genomic instability, and subsequent viral genome integration. Differences in the microenvironment and transcriptional environment of the ectocervix compared with the TZ could explain the frequent deregulation of E6 and E7 at the latter site, which can drive disease progression towards cancer.

Nup98 is an essential component of the nuclear pore that also participates in annulate lamella pore structures localized in the cytosol. Nup98 is involved in HCV assembly, though its role remains elusive.

Squamous cervical cancers generally arise as a result of persistent infection with high-risk human papillomaviruses (hrHPVs) and occur near the squamocolumnar junction (SCJ) and within the transformation zone (TZ). The susceptibility of the TZ to HPV-related carcinogenesis appears linked to epithelial cell plasticity, with squamous metaplasia originating from a specialized stem cell population at this site. Two alternative cell populations have been implicated: keratin (K)7+ve cuboidal cells located at the SCJ vs a more broadly distributed K17+ve cervical reserve cell population. To distinguish between the hypotheses, we utilized multiplex immunofluorescence and large-scale digital imaging to map cell populations at the TZ of 165 women with and without hrHPV infections. Our results did not reveal a distinct population of K7+ cuboidal cells at the SCJ but found instead that the cuboidal and columnar cells of the TZ express K7 and K8 throughout and lack the p63 transcription factor required for epithelial stratification. Squamous metaplasia and reserve cells, which are defined by their subcolumnar location and pattern of biomarker expression (K5/K17/P63), were conspicuous at cervical crypt entrances within the TZ extending proximally toward the endocervix. In HPV-infected tissue, crypt-entrance regions with thin high-grade squamous intraepithelial lesion pathology showed prominent expression of hrHPV E6/E7 mRNA, as detected by fluorescence in situ hybridization, and p16/MCM expression, with infection also apparent in neighboring reserve cells. In some instances, normal/uninfected reserve cells (E6/E7 mRNA-ve) and squamous metaplasia were not only seen close to these regions of hrHPV infection but also extended well beyond the infected area both laterally and by depth. Our results confirm that the reserve cells underneath the columnar epithelia at TZ have the potential to undergo malignant squamous transformation via reserve cell proliferation, in agreement with previous histopathological studies. These translational findings highlight the importance of understanding the molecular biology of the epithelial sites where HPV cancers develop and suggest that in high-risk individuals, treatment strategies should target a wider area than previously thought.

The human papillomavirus (HPV) life cycle is linked to epithelial cell differentiation, with viral genome amplification, E6/E7 transcription, and virion assembly spatially compartmentalized within the cervical epithelium. This organization is disrupted in transforming lesions. These fundamental observations determine what ‘bulk’ nucleic acid amplification tests (NAATs) of cervical exfoliates allow us to establish. DNA‐based assays sensitively report high‐risk HPV genome presence, which includes transient infections and virus particles. RNA‐based assays target the E6/E7 transcripts in transcriptionally active disease, which accounts for their slightly higher clinical specificity for high‐grade squamous intraepithelial lesions. No single assay defines both viral presence and disease significance, however. Cytology, p16/Ki‐67 dual stain, extended genotyping and host‐cell methylation interrogate complementary axes of risk with strong biological rationale. The loss of spatial information that limits bulk NAAT approaches matters most in mixed‐grade lesions and immunocompromised populations. Emerging spatial methods, AI‐assisted cytology and cervical cell‐lifts offer recovery of biological resolution.