Human papillomaviruses, expression of p16, and early endocervical glandular neoplasia

Adenocarcinoma in situ (ACIS) is the precursor of cervical adenocarcinoma (ACs), and its distinction from benign but morphologically atypical glandular epithelium may be difficult. The cyclin-dependent kinase inhibitor p16(ink4) is expressed in cervical squamous cell carcinomas, their precursors, and cervical ACs, and there is a strong relationship between p16 expression and the presence of human papillomavirus (HPV)-encoded E6/E7 transcription. This study analyzed 95 cases of benign and premalignant cervical glandular ACIS lesions for p16 antigen and the proliferative marker Ki-67; HPV E6/E7 transcripts were detected by RNA/RNA in situ hybridization. HPV 16 or 18 E6/E7 transcription and strong, diffuse p16 positivity were detected only in ACIS lesions. A high and moderate Ki-67 index was observed in 76% and 22% of ACIS, respectively. Thirty-three of 36 microglandular change, tubal, atypical tubal, and endometrial-type epithelia scored negative or weakly positive for p16. Distribution of staining in 3 strongly positive cases was heterogeneous. The diffuse distribution of p16 immunostaining in HPV16/18-positive glandular neoplasms supports a strong association with HPV infection and indicates that this biomarker may discriminate ACIS from its benign mimics. However, this distinction requires attention to staining distribution because p16 is focally expressed in tubal-endometrial epithelia and diffusely expressed in endometrium, indicating that in some cases the use of other biomarkers, such as Ki-67, may be necessary. Because endometrial glandular epithelia may also express p16, the diagnostic application of p16 immunohistochemistry to cytological samples is uncertain.

Specific down-modulation of Notch1 signaling in cervical cancer cells is required for sustained HPV-E6/E7 expression and late steps of malignant transformation

The Notch family of cell surface receptors plays a key role in cell-fate determination and differentiation, functioning in a cell- and context-specific manner. In mammalian cells, Notch activation is generally thought to maintain stem cell potential and inhibit differentiation, thereby promoting carcinogenesis. However, in other contexts such as primary epithelial cells (keratinocytes), increased Notch activity causes exit from the cell cycle and/or commitment to differentiation. We now report that expression of the endogenous Notch1 gene is markedly reduced in a panel of cervical carcinoma cells whereas expression of Notch2 remains elevated, and Notch1 expression is similarly reduced or absent in invasive cervical cancers. Conversely, expression of activated Notch1 causes strong growth inhibition of HPV-positive, but not HPV-negative, cervical carcinoma cells, but exerts no such effects on other epithelial tumor cells. Increased Notch1 signaling, but not Notch2, causes a dramatic down-modulation of HPV-driven transcription of the E6/E7 viral genes, through suppression of AP-1 activity by up-regulation of the Fra-1 family member and decreased c-Fos expression. Thus, Notch1 exerts specific protective effects against HPV-induced transformation through suppression of E6/E7 expression, and down-modulation of Notch1 expression is likely to play an important role in late stages of HPV-induced carcinogenesis.

Human papillomaviruses. Applications, caveats and prevention

Unlike cervical cytology, human papillomavirus (HPV) testing provides an objective assessment of neoplasia risk. The major advantages of this technology are the potential for "reflex testing" (when used with liquid-based cytology); efficient exclusion of HPV-negative women, who can be triaged to yearly follow-up; and identification of HPV-positive women, who require colposcopic triage. However, practitioners should be aware that highly sensitive HPV tests will also identify many women with little or no immediate risk of significant neoplasia, may impose a psychosocial burden on the patient and may be used or interpreted inappropriately by both practitioners and patients. However, these caveats are similar to those inherent in any screening program involving a sexually transmitted disease, and the disadvantages of HPV testing will be minimized by attention to patient concerns and a keen awareness of the limitations of this technology. Ultimately, control of cervical cancer and its precursors rests with active prevention via vaccination programs targeting HPV. If successful, such programs could radically alter the number of women requiring triage for preinvasive disease and initiate a progressive decline in cervical cancer incidence.

Managing atypical squamous cells of undetermined significance (ASCUS): human papillomavirus testing, ASCUS subtyping,or follow-up cytology?

OBJECTIVE

This study related morphologic subtype, human papillomavirus status, and a second cytologic examination to the follow-up biopsy-proven high-grade squamous intraepithelial lesion (HSIL; grade II or III cervical intraepithelial neoplasia) after a cytologic diagnosis of atypical squamous cells of undetermined significance (ASCUS).

STUDY DESIGN

Seven hundred four liquid-based cervical cytology specimens were classified as normal, "ASCUS, favor reactive" (AFR), "ASCUS, not otherwise specified," "ASCUS, favor low-grade squamous intraepithelial lesion," "ASCUS, favor HSIL" (AFHS), low-grade squamous intraepithelial lesion, and HSIL. Human papillomavirus typing used polymerase chain reaction-restriction fragment length polymorphism analysis. A longitudinal review of the cytologic and histologic records of ASCUS cases with > or =1 follow-up test or biopsy ascertained the frequency of a follow-up diagnosis of biopsy-proven HSIL (grade II or III cervical intraepithelial neoplasia).

RESULTS

Three hundred eighty-six cases (208 ASCUS, 68 normal, 86 with low-grade squamous intraepithelial lesions, and 24 with HSIL) were evaluated. High-risk human papillomavirus (HRHPV positive) was lowest with normal cytology (13%), highest with HSIL (71%), and was present in 29.8% of ASCUS cases, ranging from 22.2% (AFR) to 75% (AFHS). Most ASCUS tests (64%) were followed by a negative cytologic or histologic examination. Overall, 3.8% and 11% of ASCUS and HRHPV-positive ASCUS had histologic outcomes of HSIL. AFHS had the highest (25%) and AFR had the lowest (1.1%) proportion of HSIL outcomes. Sensitivity, specificity, and positive predictive values of human papillomavirus testing for biopsy-proven HSIL were 87.5%, 72.5%, and 11.3%, respectively.

CONCLUSION

HSIL and AFHS are distinguished by the highest frequency of HRHPV types and higher rates of HSIL outcome. The remaining categories of ASCUS are heterogeneous with respect to human papillomavirus type and HSIL risk, and the value of subclassification of these entities is dependent on the practice. A human papillomavirus detection system based on polymerase chain reaction-restriction fragment length polymorphism identifies a smaller percentage of high-risk human papillomaviruses than mixed probe-based methods, probably because of the more precise exclusion of cross-reacting low-risk human papillomavirus. Negative HRHPV findings by either system show a markedly reduced risk of an HSIL outcome. However, the relative advantage of human papillomavirus testing over follow-up cytology will be influenced by the frequency of negative follow-up cytologic examination and sensitivity of liquid-based preparations in a given practice.

Trimodal spectroscopy for the detection and characterization of cervical precancers in vivo

OBJECTIVE

The objective of this study was to assess the potential of 3 spectroscopic techniques (intrinsic fluorescence, diffuse reflectance, and light scattering) individually and in combination (trimodal spectroscopy) for the detection of cervical squamous intraepithelial lesions.

STUDY DESIGN

The study was conducted with 44 patients who underwent colposcopy for the evaluation of an abnormal Papanicolaou smear. Fluorescence and reflectance spectra were collected from colposcopically normal and abnormal sites and analyzed to extract quantitative information about tissue biochemistry and morphologic condition. This information was compared with histopathologic classification, and diagnostic algorithms were developed and validated with the use of logistic regression and cross-validation.

RESULTS

Diagnostically significant differences exist in the composition of fluorescing biochemicals, the scattering properties, and the epithelial cell nuclear morphology of cervical squamous intraepithelial lesions and non-squamous intraepithelial lesions. Trimodal spectroscopy is a superior tool for the detection of cervical squamous intraepithelial lesions than any 1 of the techniques alone.

CONCLUSION

Trimodal spectroscopy has the potential to improve the in vivo detection of precancerous cervical changes.

NAD(P)H and collagen as in vivo quantitative fluorescent biomarkers of epithelial precancerous changes

During the development of neoplasia, epithelial tissues undergo biochemical and structural changes that can manifest in tissue fluorescence. There have been several reports on different in vivo fluorescence characteristics between normal and precancerous (dysplastic) tissues. However, it has been difficult to identify and quantify the origins of these changes, mainly because of distortions introduced in measured tissue fluorescence spectra by tissue scattering and absorption. Such distortions can be removed by combining information in simultaneously measured fluorescence and reflectance spectra. Thus, we can recover the intrinsic (undistorted) tissue fluorescence. In this report, we show that extraction of the intrinsic fluorescence allows us: (a) to determine the fluorescence spectra of NAD(P)H and collagen in an in vivo environment, and (b) to use these NAD(P)H and collagen spectra to describe, quantitatively, diagnostically significant biochemical changes between normal and dysplastic tissues. Specifically, by analyzing intrinsic fluorescence of human epithelial tissue as it becomes deoxygenated in vivo, we can resolve the fluorescence spectra of NAD(P)H and collagen, two of the major tissue fluorophores. This is important because fluorescence depends on the local environment of the chromophore. Then, we extract the intrinsic fluorescence spectra of sites from 35 patients with suspected cervical lesions and 7 patients with Barrett's esophagus and describe them accurately as a linear combination of NAD(P)H and collagen contributions. In both tissue cases, we find that low collagen and high NAD(P)H fluorescence characterizes the high-grade dysplastic lesions when compared with nondysplastic tissues. These data present evidence for the presence of detectable levels of NAD(P)H fluorescence in human epithelial tissues in an in vivo setting and demonstrate that NAD(P)H and collagen may be used as quantitative fluorescence biomarkers for in vivo detection of dysplasia in the cervix and the esophagus.

A compendium of gene expression in normal human tissues

This study creates a compendium of gene expression in normal human tissues suitable as a reference for defining basic organ systems biology. Using oligonucleotide microarrays, we analyze 59 samples representing 19 distinct tissue types. Of approximately 7,000 genes analyzed, 451 genes are expressed in all tissue types and designated as housekeeping genes. These genes display significant variation in expression levels among tissues and are sufficient for discerning tissue-specific expression signatures, indicative of fundamental differences in biochemical processes. In addition, subsets of tissue-selective genes are identified that define key biological processes characterizing each organ. This compendium highlights similarities and differences among organ systems and different individuals and also provides a publicly available resource (Human Gene Expression Index, the HuGE Index, http://www.hugeindex.org) for future studies of pathophysiology.

Downregulation of placental syncytin expression and abnormal protein localization in pre-eclampsia

Development of placentation and successful pregnancy depend on co-ordinated interactions between the maternal decidua and myometrium, and the invasive properties of the fetal trophoblast. Syncytin, a protein encoded by the envelope gene of a recently identified human endogenous defective retrovirus, HERV-W, is highly expressed in placental tissue. Previously, we have shown that the major site of syncytin expression is the placental syncytiotrophoblast, a fused multinuclear syncytium originating from cytotrophoblast cells. Here we present the first evidence that in pre-eclampsia, syncytin gene expression levels are dramatically reduced. Additionally, immunohistochemical examination of normal placentae and placentae from women with pre-eclampsia reveals that the syncytin protein in placental tissue from women with pre-eclampsia is localized improperly to the apical syncytiotrophoblast microvillous membrane as opposed to its normal location on the basal syncytiotrophoblast cytoplasmic membrane. Our previous results suggest that syncytin may mediate placental cytotrophoblast fusion in vivo and may play an important role in human placental morphogenesis. The present study suggests that altered expression of the syncytin gene, and altered cellular location of its protein product, may contribute to the aetiology of pre-eclampsia.

Discrimination of complete hydatidiform mole from its mimics by immunohistochemistry of the paternally imprinted gene product p57KIP2

The p57KIP2 protein is a cell cycle inhibitor and tumor suppressor encoded by a strongly paternally imprinted gene. We explored the utility of p57KIP2 as a diagnostic marker in hydatidiform mole, a disease likely the result of abnormal dosage and consequent misexpression of imprinted genes. Using a monoclonal antibody on paraffin-embedded, formalin-fixed tissue sections, the authors evaluated p57KIP2 expression in normal placenta and in 149 gestations including 59 complete hydatidiform moles, 39 PHMs, and 51 spontaneous losses with hydropic changes. p57KIP2 was strongly expressed in cytotrophoblast and villous mesenchyme in normal placenta, all cases of partial hydatidiform moles (39 of 39) and all spontaneous losses with hydropic changes (51 of 51). In contrast, p57KIP2 expression in cytotrophoblast and villous mesenchyme was absent or markedly decreased in 58 of 59 complete hydatidiform moles. In all gestations p57KIP2 was strongly expressed in decidua and in intervillous trophoblast islands, which served as internal positive controls for p57KIP2 immunostaining. p57KIP2 immunohistochemistry can reliably identify most cases of complete hydatidiform mole irrespective of gestational age and is thus a useful diagnostic adjunct, complementary to ploidy analysis, in the diagnosis of hydatidiform mole.

Ki-67, cyclin E, and p16INK4 are complimentary surrogate biomarkers for human papilloma virus-related cervical neoplasia

Prior studies of Ki-67, cyclin E, and p16 expression have suggested that these biomarkers may be preferentially expressed in cervical neoplasia. This study examined and compared the distribution of staining for these three antigens in 1) normal and reactive epithelial changes, 2) diagnostically challenging cases (atypical metaplasia and atypical atrophy), 3) squamous intraepithelial lesions (SIL), and 4) high-and low-risk human papilloma virus (HPV) type-specific SIL. One hundred four epithelial foci from 99 biopsies were studied, including low-grade squamous intraepithelial lesions (LSIL; 24), high-grade squamous intraepithelial lesions (HSIL; 36), mature or immature (metaplastic) squamous epithelium (29), and atrophic or metaplastic epithelium with atypia (15). Cases were scored positive for Ki-67 expression if expression extended above the basal one third of the epithelium, for cyclin E if moderate to strong staining was present, and for p16 if moderate to strong diffuse or focal staining was present. HPV status was scored by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis of extracted DNA. Immunohistochemical findings were correlated with histologic and viral data. Overall, a histologic diagnosis of SIL correlated strongly with all of the biomarkers used (p <0.001). Positive scores for Ki-67, cyclin E, and p16 were seen in 68.4%, 96.7%, and 100% of LSILs and 94.7%, 91.6%, and 100% of HSILs, respectively. Positive predictive values of these three biomarkers for HPV were 82.4%, 89.5%, and 91.4%, respectively. The positive predictive value for HPV of either cyclin E or p16 was 88.7%. Strong diffuse staining for p16 was significantly associated with high-risk HPV-associated lesions. Normal or reactive epithelial changes scored positive for the three biomarkers in 7.7%, 8.0%, and 12%, respectively. Limitations in specificity included minimal or no suprabasal staining for Ki-67 in immature condylomas and occasional suprabasal staining of reactive epithelial changes (10%), diffuse weak nuclear cyclin E staining in some normal or metaplastic epithelia, and diffuse weak basal p16 staining and occasional stronger focal positivity in normal epithelia. Ki-67, cyclin E, and p16 are complementary surrogate biomarkers for HPV-related preinvasive squamous cervical disease. (Because cyclin E and p16 are most sensitive for LSIL and HSIL [including high-risk HPV], respectively, use of these biomarkers in combination for resolving diagnostic problems, with an appreciation of potential background staining, is recommended.)

Histologic and immunophenotypic classification of cervical carcinomas by expression of the p53 homologue p63: a study of 250 cases

Recent studies of the p53 homologue p63 indicate that this gene is preferentially expressed in basal and immature cervical squamous epithelium. This study correlated p63 expression with morphologic phenotype and human papillomavirus (HPV) type in a wide range of cervical neoplasms. Two hundred fifty cases of cervical carcinoma, including squamous cell carcinoma (SCCA; n = 178), adenocarcinoma (ADCA; n = 28), adenosquamous carcinoma (ASCA; n = 8), neuroendocrine carcinoma (NECA; n = 15), and other variant or mixed types (n = 21) were studied. Ninety-seven percent of SCCA, 0% of ADCA, and 0% of SCUC showed strong (>75% v <30%) positivity for p63 (P<.001). p63 sharply distinguished SCCA (p63+) from ADCA (p63-), Large-cell, poorly differentiated carcinomas were distinguished as putative glandular (glassy cell) or squamous (lymphoepithelial-like or spindle cell) types based on p63 staining. Eight (73%) of 11 neuroendocrine tumors tested were chromogranin positive; all showed no or low (<30%) levels of p63 immunostaining. Absence of p63 was also associated with a subset of nonneuroendocrine undifferentiated carcinomas. Transitions from squamous to columnar or undifferentiated morphology coincided with loss of p63 expression. A strong association between HPV 16 and p63 positivity was identified because of the colocalization of both within tumors of squamous phenotype. p63 is a powerful marker for squamous differentiation and, when diffusely expressed, excludes a glandular or neuroendocrine differentiation. p63 may be useful for differentiating pure squamous or glandular from adenosquamous carcinomas, tracking shifts in differentiation within tumors, supporting (by its absence) the diagnosis of neuroendocrine carcinomas, and clarifying the spectrum of poorly differentiated carcinomas lacking either squamous or neuroendocrine differentiation.

Multimodality therapy in early-stage neuroendocrine carcinoma of the uterine cervix

OBJECTIVE

Patients with early-stage neuroendocrine cervical carcinoma (NECC) have a high mortality rate despite aggressive therapy. The rarity of this tumor precludes initiation of a randomized, prospective trial. We reviewed our experience in early stage disease and performed a meta-analysis of the literature to identify prognostic factors and determine optimal multimodality therapy.

METHODS

Eleven women with International Federation of Gynecology and Obstetrics (FIGO) early stage (IB--IIA) NECC were treated with surgery and chemotherapy at our institutions between 1978 and 1998. Administration of radiation therapy was recorded, but not required for inclusion in this study. A gynecologic pathologist reviewed all histopathologic sections. Medical records were retrospectively reviewed and clinical data obtained. Twenty-three early-stage NECC patients who were similarly treated during the study interval were identified by a Medline search of the English literature and included in the analysis. The Kaplan--Meier method and log-rank test were used for survival analysis.

RESULTS

The overall 2-year survival rate for the 34 patients was 38%. The median age was 37 years (range, 20--75 years). Median cervical tumor diameter was 3.2 cm (range 0.5--11.0 cm). Lymphovascular space invasion was present in 21 (78%) of 27 patients (7 unknown). Fifteen (52%) of twenty-nine had lymph node metastases (5 unknown). Fifteen patients received postoperative platinum/etoposide (PE), seven received vincristine/adriamycin/cyclophosphamide (VAC), two received alternating cycles of VAC and PE, and ten received other chemotherapy regimens. Twenty women were treated with radiation therapy. The presence of lymph node metastases was a poor prognostic factor (P < 0.001). PE and VAC chemotherapy was associated with increased survival (P < 0.01).

CONCLUSION

NECC is a highly lethal variant of cervical cancer. The presence of lymph node metastases is the most important prognostic variable. Postoperative VAC or PE appears most likely to improve chances for survival.

Human papillomavirus type 16 E7 oncoprotein-induced abnormal centrosome synthesis is an early event in the evolving malignant phenotype

Genomic instability is a hallmark of malignant growth that frequently involves mitotic defects associated with centrosome abnormalities. However, the question of whether abnormal centrosomes cause genomic instability or develop secondary to other changes has not been conclusively resolved. Here we show that human papillomavirus (HPV)-16 E7 can induce abnormal centrosome synthesis before the development of extensive nuclear abnormalities. In contrast, expression of HPV-16 E6 is associated with marked nuclear atypia and concomitant accumulation of centrosomes. Our results demonstrate that HPV-16 E7-induced centrosome abnormalities represent an early event during neoplastic progression potentially driving genomic destabilization.

Surrogate biomarkers of HPV infection in cervical neoplasia screening and diagnosis

The current prevention of cervical cancer and elimination of its precursors is predicated on the identification of cervical cytologic abnormalities and their histologic confirmation. This strategy, although effective, depends on both sensitivity and specificity of cytology and precise histologic distinction between precursor lesions and their mimics during biopsy interpretation. The effective application of diagnostic criteria is operator dependent and varies as a function of experience and training. However, because human papilloma viruses (HPV) are causative agents and alter the cell cycle in cervical neoplasms, host genes interacting directly or indirectly with HPV oncoproteins have been identified in vitro. Recent research has centered on identifying the host genes upregulated in association with HPV infection, determining their suitability as "surrogate markers" for HPV infection, and using these markers to identify HPV-associated epithelial lesions in tissue or cytologic specimens. This review surveys recent advances in this field, summarizing the advantages and limitations of several candidate biomarkers, including PCNA, Ki-67, cyclin E, p16ink4, MN antigen, carcinoembryonic antigen (CEA), and telomerase in the recognition of preinvasive cervical neoplasia, and discusses their future potential in cervical cancer screening. Based on current studies, the strongest candidates for diagnosis and screening are p16 and cyclin E (squamous) and MN (glandular) biomarkers. As new genes are identified and tested, the concept of biomarkers as tools in primary screening and lesion recognition will continue to mature.

Expression of the p53 homologue p63 in early cervical neoplasia

BACKGROUND

p63, a homologue of the tumor suppressor gene p53, is expressed in embryonic, adult murine, and human basal squamous epithelium and encodes both transactivating and dominant negative transcript isoforms. Mouse embryos functionally deficient in p63 fail to replenish basal squamous epithelial cells, resulting in multiple defects that include absent genital squamous epithelium. This study investigated the expression of p63 in the human cervical transformation zone and early cervical neoplasia.

METHODS

Tissue localization of p63 was determined by immunohistochemistry in a wide range of epithelia. A correlation was also made between p63 expression and squamous basal cell (keratin 14), endocervical columnar cell (mucicarmine), and cell-cycle specific (Ki-67) markers.

RESULTS

p63 expression by immunostaining delineated basal and parabasal cells of maturing ectocervical squamous mucosa, squamous metaplasia in the cervix, and basal and subcolumnar cells of the cervical transformation zone. In atrophic epithelia immunostaining for p63 was present in all cell strata. In early cervical neoplasia, p63 expression was inversely correlated with both squamous cell maturation and nonsquamous differentiation in CIN. This biomarker also identified basal cells in a subset of preinvasive cervical neoplasms with endocervical cell differentiation that were bcl-2 and keratin 14 negative.

CONCLUSIONS

In the lower female genital tract, p63 is preferentially expressed in immature cells of squamous lineage and is not linked to cell proliferation. The broader range of p63 expression relevant to keratin 14 and bcl-2 indicates that p63 may identify additional subsets of benign and neoplastic epithelial basal cells in the cervical transformation zone and may be useful in studying cell differentiation in the early stages of neoplastic change in this region.

Identification of a basal/reserve cell immunophenotype in benign and neoplastic endometrium: a study with the p53 homologue p63

BACKGROUND

Metaplastic differentiation, including squamous, mucinous, and tubal (ciliated), is common in both benign and neoplastic endometrium, and the cell of origin for this pathway is poorly understood. In this study, expression of a marker for basal and reserve cells in cervical squamous mucosa, designated p63, was investigated in a spectrum of endometrial alterations.

METHODS

One hundred ninety different endometria from 132 patients were examined, including fetal (6), premenarchal (3), benign cyclic (29) and noncyclic (54), hyperplastic (14), and neoplastic (93) endometrial glandular epithelia. The latter included conventional endometrioid carcinomas with and without mucinous, ciliated, and squamous metaplasia, and uterine papillary serous carcinoma (UPSC).

RESULTS

p63 expression was identified in basal/subcolumnar cells in the fetal endometrium in a distribution similar to that in basal/reserve cells of the cervix. Staining was confined to individual scattered basal and suprabasal cells in cycling endometrium. In polyps and postmenopausal endometria, focal clusters of p63-positive cells were identified in inactive glands or surface epithelium. Metaplastic (squamous or mucinous) epithelia, either alone or in conjunction with hyperplasias or carcinomas, exhibited the most intense staining, primarily in basal or subcolumnar cells. In some cases, immediately adjacent nonmetaplastic columnar epithelium also stained positive. UPSCs contained only rare scattered p63-positive cells.

CONCLUSIONS

Cells with a basal or reserve cell phenotype exist in the endometrium during fetal life, are not conspicuous during the reproductive years, but may emerge during shifts in differentiation. Whether these cells signify specialized multipotential endometrial cells is not clear, but the similarity of these cells to basal/reserve cells of the cervix and their association with neoplasia merit further study.

Differential expression of MUC2 and MUC5AC in benign and malignant glandular lesions of the cervix uteri

The expression of mucin genes in the normal glandular epithelium of the endocervix has been well characterized. However, mucin gene expression in neoplastic or particular non-neoplastic glandular cervical lesions has not been addressed. This immunohistochemical study was carried out to analyze the expression of MUC2 and MUC5AC in neoplastic and non-neoplastic glandular lesions of the cervix. Monoclonal antibodies were used on paraffin-embedded sections from 41 adenocarcinomas, 2 adenosquamous carcinomas, 13 adenocarcinomas in situ (ACIS), 3 glandular dysplasias, 8 endometrioses, 5 tubal metaplasias, 17 squamous metaplasias, 3 microglandular hyperplasias and normal tissue of the endocervix, endometrium and fallopian tube. The patterns of expression of MUC2 and MUC5AC were different and in principle contrary. Focal MUC2 expression was observed almost exclusively in neoplastic lesions (36%) and not in normal epithelia and non-neoplastic lesions, the one notable exception being immature metaplasia. In contrast, strong expression of MUC5AC was observed in both normal endocervical epithelium (100%) and neoplastic lesions (73%). The expression of MUC5AC, however, was diminished in most neoplastic glandular lesions. Co-expression of MUC2 and MUC5AC was consistently documented in the lesions with intestinal differentiation. In contrast, cases of tubal metaplasia and endometriosis were negative for MUC2 and MUC5AC. These results indicate that discrimination of mucin gene expression may be helpful in discriminating lesions of the cervix.

Stratified mucin-producing intraepithelial lesions of the cervix: adenosquamous or columnar cell neoplasia?

BACKGROUND

Squamous (CIN) and glandular (ACIS) intraepithelial lesions often coexist in the same cervical specimen. However, a less common and little studied variant consists of a stratified epithelium resembling CIN in which conspicuous mucin production is present (Stratified Mucin-producing Intraepithelial LEsions (SMILE). This report describes the phenotypic characteristics of the SMILE, its associated lesions, and its immunophenotype.

METHODS

Eighteen SMILEs were identified by the presence of conspicuous cytoplasmic clearing or vacuoles in lesions otherwise resembling CIN. The morphologic spectrum of SMILEs was detailed; including associated intraepithelial and invasive cervical neoplasms. In addition, selected cases were stained for mucicarmine, markers of squamous cell/reserve cell differentiation (keratin-14 and p63), and proliferative activity (Mib-1).

RESULTS

Stratified neoplastic epithelial cells with a high Mib-1 index and a rounded or lobular contour at the epithelialstromal interface characterized SMILEs. In contrast to CIN, in which mucin droplets are confined to surface cells, mucin was present throughout the epithelium, varying from indistinct cytoplasmic clearing to discrete vacuoles. SMILEs were distinguished from benign metaplasia by nuclear hyperchromasia and a high Mib-1 index. All but three coexisted with either a squamous (CIN) or glandular (ACIS) precursor lesion. Nine of nine coexisting invasive carcinomas contained glandular, adenosquamous differentiation, or both. SMILEs stained negative for keratin-14 and variably for p63. When present, staining with p63 was confined to basal areas of SMILEs and was absent in areas of columnar differentiation.

CONCLUSIONS

SMILEs are unusual cervical intraepithelial lesions best classified as variants of endocervical columnar cell neoplasia based on immunophenotype. The distribution and immunophenotype of SMILEs are consistent with a neoplasm arising in reserve cells in the transformation zone. The coexistence of a wide spectrum of intraepithelial and invasive cell phenotypes suggests that SMILEs are a marker for phenotypic instability, emphasizing the importance of identifying SMILEs and ensuring a complete examination of specimens containing this unusual precursor lesion.

The human papillomavirus type 16 E6 and E7 oncoproteins cooperate to induce mitotic defects and genomic instability by uncoupling centrosome duplication from the cell division cycle

Loss of genomic integrity is a defining feature of many human malignancies, including human papillomavirus (HPV)-associated preinvasive and invasive genital squamous lesions. Here we show that aberrant mitotic spindle pole formation caused by abnormal centrosome numbers represents an important mechanism in accounting for numeric chromosomal alterations in HPV-associated carcinogenesis. Similar to what we found in histopathological specimens, HPV-16 E6 and E7 oncoproteins cooperate to induce abnormal centrosome numbers, aberrant mitotic spindle pole formation, and genomic instability. The low-risk HPV-6 E6 and E7 proteins did not induce such abnormalities. Whereas the HPV-16 E6 oncoprotein has no immediate effects on centrosome numbers, HPV-16 E7 rapidly induces abnormal centrosome duplication. Thus our results suggest a model whereby HPV-16 E7 induces centrosome-related mitotic disturbances that are potentiated by HPV-16 E6.

The human VASA gene is specifically expressed in the germ cell lineage

To understand the origins and function of the human germ cell lineage and to identify germ cell-specific markers we have isolated a human ortholog of the Drosophila gene vasa. The gene was mapped to human chromosome 5q (near the centromere) by radiation hybrid mapping. We show by Northern analysis of fetal and adult tissues that expression of the human VASA gene is restricted to the ovary and testis and is undetectable in somatic tissues. We generated polyclonal antibodies that bind to the VASA protein in formalin-fixed, paraffin-embedded tissue and characterized VASA protein expression in human germ cells at various stages of development. The VASA protein is cytoplasmic and expressed in migratory primordial germ cells in the region of the gonadal ridge. VASA protein is present in fetal and adult gonadal germ cells in both males and females and is most abundant in spermatocytes and mature oocytes. The gene we have isolated is thus a highly specific marker of germ cells and should be useful for studies of human germ cell determination and function.

Endocervical intraepithelial glandular atypia (dysplasia): a histopathologic, human papillomavirus, and MIB-1 analysis of 25 cases

The purpose of this study was to determine the likelihood that intraepithelial endocervical glandular atypias that are less severe than adenocarcinoma in situ (AIS) are precursors to AIS and, if so, whether they can be recognized by morphological or other means. We first assessed the frequency of atypias found in association with either AIS or invasive adenocarcinoma (ACA) and then tested these cases and additional randomly encountered cases for the presence of human papillomavirus (HPV) and for their proliferative (Ki-67) index. Lesions not fulfilling the classic criteria for AIS were subdivided into high-grade (HGGA) and low-grade glandular atypias (LGGA). Atypias and controls were microdissected and tested for HPV by the polymerase chain reaction. Serial sections were labeled for Ki-67 by immunohistochemistry with the MIB-1 antibody. Eight cases (6.8%) containing glandular atypia were found in a search of 117 consecutive cone biopsy or hysterectomy specimens that also had either AIS, ACA, or both. An additional 17 cases were either randomly encountered or were received in consultation. In 3 cases, both HGGA and LGGA were present, yielding a total of 28 lesions for study. Of the 9 HGGA cases that were associated with either AIS, ACA, or CIN II/III, 6 were positive for HPV; MIB-1 reactivity in all 6 was present in greater than 25% of the nuclei. Of the 3 HPV-negative HGGA cases in this group, the 2 that were tested showed low MIB-1 reactivity. All 3 cases of HGGA that were not associated with a diagnostic lesion were HPV-negative and had low MIB-1 reactivity. Of the 6 LGGAs associated with either AIS, ACA, or CIN II/III, 1 was positive for HPV; MIB-1 was nonreactive in this case and was low in all of the HPV-negative cases in this group that were tested. Of 10 LGGAs not associated with a diagnostic lesion, or with a low-grade squamous lesion as the only other abnormality, 2 were positive for HPV. Of these 2, one had an MIB-1 reactivity of greater than 25% and also had intestinal differentiation. MIB-1 reactivity was elevated in 2 of the 8 HPV-negative LGGAs from this group. All 10 ciliated atypias (3 HGGA, 7 LGGA) were HPV-negative and had low MIB-1 reactivity. One HPV-positive AIS control case was focally ciliated. Six of 7 foci with apoptotic bodies (5 HGGA, 2 LGGA) were HPV-positive. The infrequent occurrence of glandular atypias with AIS and ACA and the low rate of HPV DNA positivity when they are found in isolation are evidence that most AIS lesions do not evolve through morphologically identifiable antecedents and that most isolated atypias are not AIS precursors. HGGAs associated with AIS or CIN II/III maybe either precursors to or subtle variants of AIS. However, LGGAs similarly encountered are unlikely to be either. Elevated MIB-1 reactivity may be helpful diagnostically in selected cases, but it is not reliable as an independent criterion. The presence of cilia in isolated glandular atypias favors a nonneoplastic process, whereas intestinal differentiation and apoptotic bodies each suggest neoplasia.

Adenoid basal carcinomas of the cervix: a unique morphological evolution with cell cycle correlates

Adenoid basal carcinoma (ABC) is a rare cervical carcinoma of postmenopausal women composed of small basal-type (basaloid) cells with focal endocervical ("adenoid") differentiation. ABCs are associated with high-grade squamous intraepithelial lesions (HSIL) and contain integrated human papillomavirus type 16 DNA. However, ABCs have a favorable prognosis and do not metastasize. Five (5) ABCs were analyzed histologically for a marker distinguishing basal/ squamous from columnar (adenoid) differentiation (p63) and cell cycle activity (Ki-67), and compared with 20 cervical (CC) carcinomas. In contrast to other CCs, ABCs contained 4 distinct components, including (1) a classic HSIL; (2) a limited invasive component with squamoid maturation, often with a discrete layer of peripheral basal cells; (3) outgrowth of small basal cells from either HSIL or squamoid areas; (4) focal endocervical (adenoid) differentiation. ABCs showed distinct differences in cell cycle activity relative to CCs. Ki-67 positivity was high in associated HSILs but remained high and concentrated in the suprabasal cells of the invasive squamoid component of ABC. Moreover, proliferative index was variable to sharply reduced in areas of basaloid and adenoid differentiation, in contrast to conventional CCs. ABC is a unique neoplasm, not only by its transition through multiple phenotypes during invasion, but also by a proliferative index that is high in more mature neoplastic cells during the infiltrative process and reduced with progressive basal differentiation. The precise mechanism underlying this unique process of tumor evolution is unclear. However, the postmenopausal status of these patients suggests that host factors related to aging may influence tumor evolution and morphology after HPV 16 infection.

Allelic imbalance in lichen sclerosus, hyperplasia, and intraepithelial neoplasia of the vulva

BACKGROUND

Few studies have addressed in detail the genetic alterations that occur in vulvar squamous carcinomas (VSCC) and their precursor lesions. In a previous study, we determined the most common chromosomal loci for allelic imbalance (AI) in HPV-positive and -negative VSCCs. The present study was designed to determine whether AI and the microsatellite instability phenotype (MIN) were present in epithelial lesions known to be associated with VSCC.

DESIGN

Fifty-seven epithelial loci were analyzed, including HPV-positive (classic) and -negative (differentiated) vulvar intraepithelial neoplasms (VINs), lichen sclerosus (LS), and nonatypical hyperplasias. Thirty-one epithelial loci (55%) were obtained from patients with associated invasive vulvar carcinoma. HPV status was determined by polymerase chain reaction analysis. AI and MIN were determined by comparisons of microdissected target tissues with stromal controls, targeting 11 chromosomal loci.

RESULTS

AI was identified in all epithelial categories, involving at least one chromosomal locus in 67, 53, 50, and 43% of classic VIN, differentiated VIN, hyperplasia, and LS. MIN was infrequent (10-13%), but confined to HPV-negative epithelial changes. HPV-positive lesions generally scored for AI more frequently, but certain loci scored nearly equally in both HPV-positive and -negative lesions, including 8p, 11q, and 17p. There were no differences in frequency of AI between epithelia with and without associated invasive carcinoma.

CONCLUSIONS

The presence of allelic imbalance in vulvar hyperplasia and LS supports the hypothesis that these alterations are at greater risk for neoplasia despite the absence of conspicuous cellular atypia. A model is proposed in which these changes represent monoclonal expansion and are at empirically greater risk for subsequent "critical events" leading to morphologic atypia (VIN). The possibility that these early genetic changes influence both HPV-positive and -negative pathways merits further study.