HPV16-Immortalized Cells from Human Transformation Zone and Endocervix are More Dysplastic than Ectocervical Cells in Organotypic Culture

Abstract

A major risk factor for cervical cancer is persistent infection with high-risk human papillomaviruses (HPV) which can cause cervical intraepithelial neoplasia. Greater than 90% of cervical cancers develop in the transformation zone (TZ), a small region of metaplastic squamous epithelium at the squamocolumnar junction between endocervix and ectocervix. However, it is unclear why this region is highly susceptible to malignant progression. We hypothesized that cells from TZ were more susceptible to dysplastic differentiation, a precursor to cervical cancer. We used three-dimensional organotypic culture to compare differentiation of HPV16-immortalized epithelial cell lines derived from ectocervix, TZ, and endocervix. We show that immortal cells from TZ or endocervix form epithelia that are more dysplastic than immortal cells from ectocervix. A higher percentage of immortal cells from TZ and endocervix express the proliferation marker Ki-67 and are positive for phospho-Akt. Immortal cells from TZ and endocervix invade collagen rafts and express increased levels of matrix metalloproteinase-1. Inhibition of MMP-1 or Akt activity blocks invasion. We conclude that HPV16-immortalized cells cultured from TZ or endocervix are more susceptible to dysplastic differentiation, and this might enhance their susceptibility to cervical cancer.

Opposing Wnt signals regulate cervical squamocolumnar homeostasis and emergence of metaplasia

“…Cervical cancer is the fourth most common cancer in women 4 , more than 90% of which originate at the transition zone 5 , 6 . The cervix connects the uterine cavity with the vagina and consists of the ectocervix and the endocervix.…”

Human papillomavirus E6 and E7: What remains?

“…In addition, the importance of the stroma and extracellular matrix in HPV infection and cancer development have long been understood [ [91] , [92] , [93] , [94] , [95] , [96] ], but it is only now becoming technically possible to include them in model systems [ [97] , [98] , [99] , [100] ]. It is also important that models are developed to reflect the tissues of origin of various different HPV-induced diseases [ 101 ]; the growth, differentiation characteristics, and tissue architecture of the ectocervix differ from those from the endocervix, or anus, and those of the tonsil are even more markedly different [ 19 , 102 ]. The mouse models for HPV-induced carcinogenesis (reviewed in Refs.…”

Organoids of the Female Reproductive Tract: Innovative Tools to Study Desired to Unwelcome Processes

“…Starting from the original squamocolumnar junction (SCJ) and due to the acidity of the vaginal compared to the endocervical environment, transformative pathways are activated in bipotent progenitor, so-called "reserve" cells, subjacent to columnar cells to replace and replenish the exposed surface with metaplastic squamous epithelium (Herfs et al, 2013;Malpica, 2014). Even though carcinomas arising from both epithelia display only minute differences in clinical risk factors and majority of dedicated HPV types, much is still to be elucidated on how they pathogenetically diverge (Berrington de González et al, 2004;Bray et al, 2005;de Sanjose et al, 2010;Patterson and Pru, 2013;Deng et al, 2018;Stewart et al, 2019). It has been postulated that cytokeratin (CK-) 7-positive stem cells residing at the SCJ, may represent a cell population in which cervical carcinogenesis originates (Herfs et al, 2012(Herfs et al, , 2013.…”