The role of ERBB2 signaling in HPV-induced pathologies - Project Summary / Abstract
High-risk human papillomaviruses (HPV) are a group of viral pathogens that infect and replicate in keratinocytes
in the stratified squamous epithelium (SE) of the skin and mucosa, and are known to cause nearly 5% of all
human cancers. HPV infection is highly prevalent, with >40 million currently infected individuals in the United
States alone. Prevention of HPV-associated malignancies is limited by a lack of antivirals, and development of
these therapeutics is in turn limited by the lack of knowledge on virus-host interactions preceding and leading to
carcinogenesis in SE. The differentiation program of SE plays an important role in supporting the HPV life cycle.
However, identification of distinct cell populations responsible for supporting this progression had been limited
by the lack of single-cell resolution tools to define such populations. In a recent study, single-cell RNA sequencing
was utilized to identify and compare keratinocytes populations present in HPV-naïve and HPV-infected SE. A
novel keratinocyte cell population enriched in HPV-infected epithelium was identified, and termed HPV-induced
differentiation dissonant epithelial non-conventional (HIDDEN) cells. These cells form a novel cellular
compartment on the surface of HPV-infected, but not uninfected epithelium, and are implicated in carcinogenesis.
The Erb-B2 receptor tyrosine kinase 2 (ERBB2) is a part of a core HIDDEN signature and is independently
correlated with adverse patient outcomes in cervical squamous cell carcinomas (SCCs).
ERBB2 can be clinically targeted in other cancers (e.g., breast cancer), and pre-clinical studies have suggested
cooperative regulation between ERBB2 and HPV. However, the relationship between HPV and ERBB2 in the
context of its relevance for the HPV life cycle and resulting SCC-related pathologies remains unexplored, and
such studies require 3D models of SE. Based on preliminary data and the literature, in this proposal it is
hypothesized that HPV infection enhances expression and activation of ERBB2 in the surface HIDDEN cell
compartment, and that ERBB2 signaling promotes HPV pathologies in SE. To test this hypothesis, HPV+ and
HPV– 3D organotypic epithelial rafts will be utilized to spatially resolve ERBB2 expression, activation, and
downstream signaling, and define the viral gene responsible for ERBB2 upregulation (Aim 1). Rafts will also be
utilized to define whether ERBB2 is required for HIDDEN formation, viral genome copy number and expression,
and HPV-driven pathologies, using genetic inhibition of ERBB2 and FDA-approved drugs (Aim 2). The results
will determine whether ERBB2 signaling promotes the HPV viral life cycle and dependent pathologies, and
whether clinically relevant HPV phenotypes can be suppressed via existing FDA-approved drugs for the possible
prevention of HPV-related cancer types.
