Microanatomy of the cervical and anorectal squamocolumnar junctions: a proposed model for anatomical differences in HPV-related cancer risk.
ABSTRACT: Human papilloma virus (HPV) infection causes cancers and their precursors (high-grade squamous intraepithelial lesions) near cervical and anal squamocolumnar junctions. Recently described cervical squamocolumnar junction cells are putative residual embryonic cells near the cervical transformation zone. These cells appear multipotential and share an identical immunophenotype (strongly CK7-positive) with over 90% of high-grade squamous intraepithelial lesions and cervical carcinomas. However, because the number of new cervical cancers discovered yearly world wide is 17-fold that of anal cancer, we posed the hypothesis that this difference in cancer risk reflects differences in the transition zones at the two sites. The microanatomy of the normal anal transformation zone (n=37) and topography and immunophenotype of anal squamous neoplasms (n=97) were studied. A discrete anal transition zone was composed of multilayered CK7-positive/p63-negative superficial columnar cells and an uninterrupted layer of CK7-negative/p63-positive basal cells. The CK7-negative/p63-positive basal cells were continuous with-and identical in appearance to-the basal cells of the mature squamous epithelium. This was in contrast to the cervical squamocolumnar junction, which harbored a single-layered CK7-positive/p63-negative squamocolumnar junction cell population. Of the 97 anal intraepithelial neoplasia/squamous cell carcinomas evaluated, only 27% (26/97) appeared to originate near the anal transition zone and only 23% (22/97) were CK7-positive. This study thus reveals two fundamental differences between the anus and the cervix: (1) the anal transition zone does not harbor a single monolayer of residual undifferentiated embryonic cells and (2) the dominant tumor immunophenotype is in keeping with an origin in metaplastic (CK7-negative) squamous rather than squamocolumnar junction (CK7-positive) epithelium. The implication is that, at birth, the embryonic cells in the anal transition zone have already begun to differentiate, presenting a metaplasia that-similar to vaginal and vulvar epithelium-is less prone to HPV-directed carcinogenesis. This in turn underscores the link between cancer risk and a very small and discrete population of vulnerable squamocolumnar junction cells in the cervix.
Project description:<h4>Background</h4>Human papillomavirus (HPV)-related anal cancer lesions are often found adjacent to the squamocolumnar junction (SCJ). We have assessed the histopathology and associated HPV genotypes in anal SCJ lesions in surgically excised anal warts in HIV-negative and -positive patients.<h4>Methods</h4>Histopathology identified 47 squamous intraepithelial lesions (SILs) adjacent to the SCJ amongst a total of 145 cases of clinically diagnosed anal condylomata. The anal SCJ lesions were further analyzed with p16, CK7 and p63 immunohistochemistry and HPV genotyping.<h4>Results</h4>Sixteen (16/47) of the excised anal wart lesions contained HSIL; Three were HSIL and exclusively associated with oncogenic HPVs. A further thirteen (13/47) were mixed lesions. Of these eight were HSILs with LSIL and six were HSILs with papillary immature metaplasia (PIM); Ten of the mixed lesions were associated with one or more oncogenic HPVs, while three cases were exclusively associated with HPV6.<h4>Conclusions</h4>Clinically diagnosed anal warts cannot be assumed to be limited to low-grade lesions as anal warts of the SCJ often show heterogeneous lesions, with coexistence of LSIL, PIM, and HSIL. Lesions showing PIM, however, may mimic HSIL, because they are hypercellular, but lack the nuclear atypia and conspicuous mitotic activity of HSIL; and are p16 negative.
Project description:Infection by carcinogenic human papillomaviruses (HPV) results in precancers [cervical intraepithelial neoplasia (CIN)] and cancers near the ectoendocervical squamocolumnar (SC) junction of the cervix. However, the specific cells targeted by HPV have not been identified and the cellular origin of cervical cancer remains elusive. In this study, we uncovered a discrete population of SC junctional cells with unique morphology and gene-expression profile. We also demonstrated that the selected junctional biomarkers were expressed by a high percentage of high-grade CIN and cervical cancers associated with carcinogenic HPVs but rarely in ectocervical/transformation zone CINs or those associated with noncarcinogenic HPVs. That the original SC junction immunophenotype was not regenerated at new SC junctions following excision, not induced by expression of viral oncoproteins in foreskin keratinocytes, and not seen in HPV-related precursors of the vagina, vulva, and penis further support the notion that junctional cells are the source of cervical cancer. Taken together, our findings suggest that carcinogenic HPV-related CINs and cervical cancers are linked to a small, discrete cell population that localizes to the SC junction of the cervix, expresses a unique gene expression signature, and is not regenerated after excision. The findings in this study uncover a potential target for cervical cancer prevention, provide insight into the risk assessment of cervical lesions, and establish a model for elucidating the pathway to cervical cancer following carcinogenic HPV infection.
Project description: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.
Project description:Barrett's esophagus is an intestine-like metaplasia and precursor of esophageal adenocarcinoma. Triggered by gastroesophageal reflux disease, the origin of this metaplasia remains unknown. p63-deficient mice, which lack squamous epithelia, may model acid-reflux damage. We show here that p63 null embryos rapidly develop intestine-like metaplasia with gene expression profiles similar to Barrett's metaplasia. We track its source to a unique embryonic epithelium that is normally undermined and replaced by p63-expressing cells. Significantly, we show that a discrete population of these embryonic cells persists in adult mice and humans at the squamocolumnar junction, the source of Barrett's metaplasia. We show that upon programmed damage to the squamous epithelium, these embryonic cells migrate toward adjacent, specialized squamous cells in a process that may recapitulate early Barrett's. Our findings suggest that certain precancerous lesions, such as Barrett's, initiate not from genetic alterations but from competitive interactions between cell lineages driven by opportunity.
Project description:Persistent infection with high-risk human papillomavirus (HPV) is a major risk factor for cervical cancer. Greater than 90% of these cancers originate in the cervical transformation zone (TZ), a narrow region of metaplastic squamous epithelium that develops at the squamocolumnar junction between the ectocervix and endocervix. It is unclear why the TZ has high susceptibility to malignant transformation and few studies have specifically examined cells from this region. We hypothesized that cells cultured from TZ are more susceptible to cellular immortalization, an alteration that contributes to malignant development. We cultured primary epithelial cells from each region of human cervix (ectocervix, endocervix and TZ) and measured susceptibility to immortalization after transfection with the complete HPV-16 genome or infection of HPV16 E6/E7 retroviruses. Cells cultured from each cervical region expressed keratin markers (keratin 14 and 18) that confirmed their region of origin. In contrast to our prediction, cells from TZ were equally susceptible to immortalization as cells from ectocervix or endocervix. Thus, increased susceptibility of the TZ to cervical carcinogenesis is not due to increased frequency of immortalization by HPV-16. We developed a series of HPV16-immortalized cell lines from ectocervix, endocervix and TZ that will enable comparisons of how these cells respond to factors that promote cervical carcinogenesis.
Project description:Cervical reserve cells are epithelial progenitor cells that are pathologically evident as the origin of cervical cancer. Thus, investigating the characteristics of cervical reserve cells could yield insight into the features of cervical cancer stem cells (CSCs). In this study, we established a method for the regeneration of cervical reserve cell-like properties from human induced pluripotent stem cells (iPSCs) and named these cells induced reserve cell-like cells (iRCs). Approximately 70% of iRCs were positive for the reserve cell markers p63, CK5 and CK8. iRCs also expressed the SC junction markers CK7, AGR2, CD63, MMP7 and GDA. While iRCs expressed neither ER? nor ER?, they expressed CA125. These data indicated that iRCs possessed characteristics of cervical epithelial progenitor cells. iRCs secreted higher levels of several inflammatory cytokines such as macrophage migration inhibitory factor (MIF), soluble intercellular adhesion molecule 1 (sICAM-1) and C-X-C motif ligand 10 (CXCL-10) compared with normal cervical epithelial cells. iRCs also expressed human leukocyte antigen-G (HLA-G), which is an important cell-surface antigen for immune tolerance and carcinogenesis. Together with the fact that cervical CSCs can originate from reserve cells, our data suggested that iRCs were potent immune modulators that might favor cervical cancer cell survival. In conclusion, by generating reserve cell-like properties from iPSCs, we provide a new approach that may yield new insight into cervical cancer stem cells and help find new oncogenic targets.
Project description:In several organ systems, the transitional zone between different types of epithelium is a hotspot for pre-neoplastic metaplasia and malignancy, but the cells of origin for these metaplastic epithelia and subsequent malignancies remain unknown. In the case of Barrett's oesophagus, intestinal metaplasia occurs at the gastro-oesophageal junction, where stratified squamous epithelium transitions into simple columnar cells. On the basis of a number of experimental models, several alternative cell types have been proposed as the source of this metaplasia but in all cases the evidence is inconclusive: no model completely mimics Barrett's oesophagus in terms of the presence of intestinal goblet cells. Here we describe a transitional columnar epithelium with distinct basal progenitor cells (p63+KRT5+KRT7+) at the squamous-columnar junction of the upper gastrointestinal tract in a mouse model. We use multiple models and lineage tracing strategies to show that this squamous-columnar junction basal cell population serves as a source of progenitors for the transitional epithelium. On ectopic expression of CDX2, these transitional basal progenitors differentiate into intestinal-like epithelium (including goblet cells) and thereby reproduce Barrett's metaplasia. A similar transitional columnar epithelium is present at the transitional zones of other mouse tissues (including the anorectal junction) as well as in the gastro-oesophageal junction in the human gut. Acid reflux-induced oesophagitis and the multilayered epithelium (believed to be a precursor of Barrett's oesophagus) are both characterized by the expansion of the transitional basal progenitor cells. Our findings reveal a previously unidentified transitional zone in the epithelium of the upper gastrointestinal tract and provide evidence that the p63+KRT5+KRT7+ basal cells in this zone are the cells of origin for multi-layered epithelium and Barrett's oesophagus.
Project description:<h4>Background</h4>Cervical cancer screening might contribute to the prevention of anal cancer in women. We aimed to investigate if routine cervical cancer screening results-namely high-risk human papillomavirus (HPV) infection and cytohistopathology-predict anal HPV16 infection, anal high-grade squamous intraepithelial lesions (HSIL) and, hence, anal cancer.<h4>Methods</h4>We did a systematic review of MEDLINE, Embase, and the Cochrane library for studies of cervical determinants of anal HPV and HSIL published up to Aug 31, 2018. We centrally reanalysed individual-level data from 13?427 women with paired cervical and anal samples from 36 studies. We compared anal high-risk HPV prevalence by HIV status, cervical high-risk HPV, cervical cytohistopathology, age, and their combinations, using prevalence ratios (PR) and 95% CIs. Among 3255 women with anal cytohistopathology results, PRs were similarly calculated for all anal HSIL and HPV16-positive anal HSIL.<h4>Findings</h4>Cervical and anal HPV infections were highly correlated. In HIV-negative women, anal HPV16 prevalence was 41% (447/1097) in cervical HPV16-positive versus 2% (214/8663) in cervical HPV16-negative women (PR 16·5, 95% CI 14·2-19·2, p<0·0001); these values were 46% (125/273) versus 11% (272/2588) in HIV-positive women (4·4, 3·7-5·3, p<0·0001). Anal HPV16 was also associated with cervical cytohistopathology, with a prevalence of 44% [101/228] for cervical cancer in HIV-negative women (PR vs normal cytology 14·1, 11·1-17·9, p<0·0001). Anal HSIL was associated with cervical high-risk HPV, both in HIV-negative women (from 2% [11/527] in cervical high-risk HPV-negative women up to 24% [33/138] in cervical HPV16-positive women; PR 12·9, 95% CI 6·7-24·8, p<0·0001) and HIV-positive women (from 8% [84/1094] to 17% [31/186]; 2·3, 1·6-3·4, p<0·0001). Anal HSIL was also associated with cervical cytohistopathology, both in HIV-negative women (from 1% [5/498] in normal cytology up to 22% [59/273] in cervical HSIL; PR 23·1, 9·4-57·0, p<0·0001) and HIV-positive women (from 7% [105/1421] to 25% [25/101]; 3·6, 2·5-5·3, p<0·0001). Prevalence of HPV16-positive anal HSIL was 23-25% in cervical HPV16-positive women older than 45 years (5/20 in HIV-negative women, 12/52 in HIV-positive women).<h4>Interpretation</h4>HPV-based cervical cancer screening programmes might help to stratify anal cancer risk, irrespective of HIV status. For targeted secondary anal cancer prevention in high-risk groups, HIV-negative women with cervical HPV16, especially those older than 45 years, have a similar anal cancer risk profile to that of HIV-positive women.<h4>Funding</h4>International Agency for Research on Cancer.
Project description:In July 2012 the IFCPC adopted a revised terminology for colposcopic examinations of the uterine cervix. In 2012, the Boards of the Arbeitsgemeinschaft Kolposkopie (AGK - Austrian Society of Colposcopy), the Arbeitsgemeinschaft für Kolposkopie und Zervixpathologie (AGKOL - Swiss Society of Colposcopy and Cervical Pathology) and the Arbeitsgemeinschaft für Kolposkopie und Zervixpathologie (AGCPC - German Society of Colposcopy and Cervical Pathology) accepted the validity of the 2011 IFCPC nomenclature and recommended its use in general clinical practice across German-speaking countries. The revised nomenclature was devised so that examiners can evaluate colposcopic criteria according to a specific scheme. At the start of the examination, the examiner must assess whether the colposcopy is representative or not. 1. Can the examination be classed as adequate or inadequate (reasons must be given)? 2. How would you describe the visibility of the squamocolumnar junction and categorize the transformation zone? Below we discuss some aspects of this general assessment as outlined in the nomenclature which were found to require further clarification for general practice.
Project description:Junctional adhesion molecule-A (JAM-A), which belongs to the IgG superfamily, is a tight junction molecule associated with epithelial and endothelial barrier function. Overexpression of JAM-A is also closely associated with invasion and metastasis of cancers such as breast cancer, lung cancer and pancreatic cancer. However, little is known about the mechanism in overexpression of JAM-A in head and neck squamous cell carcinoma (HNSCC). In the present study, we found high expression of JAM-A at the protein and mRNA levels in HNSCC tissues, including those of the oropharynx, larynx, and hypopharynx, together with high protein expression of ?-catenin, p63, ?Np63 and GATA-3. Furthermore, in ELISA, a significant increase of soluble JAM-A in the sera of HNSCC patients was observed compared to healthy subjects. Knockdown of JAM-A by siRNA inhibited cell proliferation, invasion and migration in the HNSCC cell line Detroit562 in vitro. JAM-A expression in Detroit562 was increased via a distinct signal transduction pathway including NF-?B. Expression of JAM-A, ?-catenin, p63 and ?Np63 in Detroit562 was decreased under hypoxia. Knockdown of p63, ?Np63 or GATA-3 by siRNAs reduced JAM-A expression in Detroit562. In primary cultured HNSCC cells in which CK7, p63, ?Np63 and GATA-3 were detected, JAM-A expression was decreased by knockdown of p63 or ?Np63. These results indicate that JAM-A is a biomarker of malignancy in HNSCC and that plasma soluble JAM-A may contribute to serum-based diagnosis of HNSCC. The mechanism of dysregulation of JAM-A via p63/GATA-3 is important in possible molecular targeted therapy for HNSCC.