HPV E6/E7 RNA in situ hybridization signal patterns as biomarkers of three-tier cervical intraepithelial neoplasia grade

Primary lung adenocarcinoma harboring upper mediastinal lymphatic skip metastasis of cervical squamous cell carcinoma: A case report and literature review

The upper mediastinal lymph nodes are a rare site of metastasis in early-stage cervical cancer, but they are a common site of metastasis in lung cancer. Notably, standard approaches for identifying the source of metastasis and subsequent treatment are currently lacking. The present study describes the case of a patient with primary lung adenocarcinoma harboring upper mediastinal lymphatic skip metastasis from cervical squamous cell carcinoma 2 years after a radical hysterectomy. During video-assisted thoracoscopic surgery, it was indicated that the patient had a tendency for metastasis to the upper mediastinal lymph nodes from the lung tumor. Pathological examination confirmed the presence of metastasis; however, it was confirmed to originate from cervical carcinoma, rather than lung adenocarcinoma. In conclusion, for patients with lung cancer and concurrent malignancies, metastatic lymph nodes discovered during surgery may originate from the previous malignancy. Surgical management of oligometastatic lymph nodes in the mediastinum can be a potential treatment option, albeit one that may necessitate the integration of adjuvant treatment modalities as warranted by the individual case.

Histopathological and Virological Findings of a Penile Papilloma in a Japanese Stallion with Equus Caballus Papillomavirus 2 (EcPV2)

Equus caballus papillomavirus 2 (EcPV2) is known to cause genital neoplasms in horses. However, reports on EcPV2 in Japan and Asia are limited. Herein, we present the histopathological and virological findings of the first reported case of an EcPV2-associated penile mass in Japan. The patient was a 22-year-old stallion with a history of breeding in Japan and abroad. Histopathological examination contained RNA in situ hybridization targeting the E6/E7 region and an immunohistochemical approach, and whole-genome sequencing was conducted within the viral examination. Proliferating epidermal cells were observed, and EcPV2 E6/E7 mRNA was detected within the epidermis, which was interpreted as viral papilloma. The detected EcPV2 virus was genetically close to foreign strains and different from the strain previously reported from a Japanese mare. This suggests that various types of EcPV2 might already exist among horses in Japan. Although the mass reported herein was not malignant based on histopathological findings and the absence of recurrence, its presence on the penis would be an obstacle to breeding. These results provide a better understanding of the pathogenesis and diversity of EcPV2.

The human papillomavirus late life cycle and links to keratinocyte differentiation

Regulation of human papillomavirus (HPV) gene expression is tightly linked to differentiation of the keratinocytes the virus infects. HPV late gene expression is confined to the cells in the upper layers of the epithelium where the virus capsid proteins are synthesized. As these proteins are highly immunogenic, and the upper epithelium is an immune-privileged site, this spatial restriction aids immune evasion. Many decades of work have contributed to the current understanding of how this restriction occurs at a molecular level. This review will examine what is known about late gene expression in HPV-infected lesions and will dissect the intricacies of late gene regulation. Future directions for novel antiviral approaches will be highlighted.

Visualization of Individual RNA Molecules by Proximity Ligation-Based Chromogenic In Situ Hybridization Assay

RNA in situ hybridization reveals the abundance and location of gene expression in cells or tissues, providing a technical basis for the clinical diagnosis of diseases. In this chapter, we show a "V" shape probe-mediated single-molecule chromogenic in situ hybridization (vsmCISH) technique for bright-field visualization of individual RNA molecules. In our method, several pairs of target hybridization probes are hybridized to RNA molecules and each probe pair forms a "V" shape overhang. The overhang oligonucleotides then mediated the proximity ligation to form DNA circles, followed by rolling circle amplification for signal enhancement and enzyme-catalyzed chromogenic reaction-based readout. The colorimetric assay avoids problems such as photobleaching and autofluorescence of current fluorescent in situ hybridization-based single-molecule RNA detection techniques. Furthermore, the relatively straightforward protocol makes the method useful for biological research and clinical diagnosis applications.

Incidence and Clinicopathologic Characteristics of Human Papillomavirus-independent Invasive Squamous Cell Carcinomas of the Cervix: A Morphologic, Immunohistochemical, and Human Papilloma-Virologic Study of 670 Cases

We aimed to determine the frequency of human papillomavirus-independent (HPVI) cervical squamous cell carcinoma (SCC) and to describe clinicopathologic characteristics. Among 670 patients with surgically treated SCCs in an established multi-institutional cohort, 447 had available tissue. Tissue microarrays were constructed and studied by in situ hybridization (ISH) for high-risk and low-risk human papillomavirus (HPV) mRNA and immunohistochemistry for p16 and p53. Tumors were HPVI if negative by HPV ISH and they failed to show diffuse p16 positivity by immunohistochemistry, and human papillomavirus-associated (HPVA) if positive by HPV ISH. Ten HPVI SCCs and 435 HPVA SCCs were identified; 2 cases were equivocal and excluded from analysis. The overall rate of HPVI SCC was low (2%) but was higher among older patients (7% in patients above 60 y of age and 17% in patients above 70 y of age). Compared with HPVA, patients with HPVI SCC were significantly older (median age, 72 vs. 49, P <0.001) and diagnosed at a higher stage (40% vs. 18% with stage III/IV disease, P =0.055). p53 expression was varied; 2 cases (20%) had null expression and 8 (80%) had wild-type expression. HPVI SCCs were heterogenous, with keratinizing, nonkeratinizing, and warty morphologies observed. Several cases had a precursor lesion reminiscent of differentiated vulvar intraepithelial neoplasia, with prominent basal atypia and hypereosinophilia or a basaloid-like morphology. Two patients (20%) had distant recurrences within 12 months, and 3 (30%) died of disease during follow-up. HPVI SCCs are rare tumors that are more common among older patients with higher stage disease and have important clinical and histologic differences from HPVA SCCs.

Histopathologic and molecular characterization of Erethizon dorsatum papillomavirus 1 and Erethizon dorsatum papillomavirus 2 infection in North American porcupines (Erethizon dorsatum)

Erethizon dorsatum papillomavirus 1 (EdPV1) and Erethizon dorsatum papillomavirus 2 (EdPV2) are associated with cutaneous papillomas in North American porcupines (Erethizon dorsatum). This study defined gross, histopathologic, and molecular characteristics of viral papillomas in 10 North American porcupines submitted to the New York State Animal Health Diagnostic Center. Investigation for the presence of EdPV1 and EdPV2 DNA via polymerase chain reaction (PCR) was performed in 9 of the 10 (90.0%) porcupines, and all porcupines were investigated for the detection and localization of EdPV1 and EdPV2 E6 and E7 nucleic acid via chromogenic in situ hybridization (CISH). Next-generation sequencing (NGS) was performed in 2 porcupines. Papillomas were diagnosed on the muzzle (n = 4), caudal dorsum (n = 1), upper lip (n = 1), chin (n = 1), gingiva (n = 2), and nasal planum (n = 1). Histologically, the lesions consisted of hyperplastic epidermis or epithelium with orthokeratotic keratin, prominent keratohyalin granules, and intranuclear inclusion bodies. PCR identified EdPV1 in 6 of 9 samples and EdPV2 in the remaining 3 samples. NGS resulted in 100% genome coverage of EdPV1 and 76.20% genome coverage of EdPV2 compared with GenBank reference sequences, with 99.8% sequence identity to the complete EdPV2 L1 gene of a novel subtype recently identified in France. Hybridization patterns in 9 of the 10 (90.0%) porcupines were characterized by strong nuclear signals in the superficial epidermis, with strong nuclear and punctate cytoplasmic signals in the stratum spinosum and basale. In one animal, CISH suggested dual EdPV1 and EdPV2 infection.

Novel In Situ Hybridization Assay for Chromogenic Single-Molecule Detection of Human Papillomavirus E6/E7 mRNA

RNA plays a vital role in the physiological and pathological processes of cells and tissues. However, RNA in situ hybridization applications in clinical diagnostics are still limited to a few examples. In this study, we developed a novel in situ hybridization assay for human papillomavirus (HPV) E6/E7 mRNA by taking advantage of specific padlock probing and rolling circle amplification, combined with chromogenic readout. We designed padlock probes for 14 types of high-risk HPV and demonstrated that E6/E7 mRNA could be visualized in situ as discrete dot-like signals using bright-field microscopy. Overall, the results are consistent with the clinical diagnostics lab's hematoxylin and eosin (H&E) staining and p16 immunohistochemistry test results. Our work thus shows the potential applications of RNA in situ hybridization for clinical diagnostics using chromogenic single-molecule detection, offering an alternative technical option to the current commercially available kit based on branched DNA technology. IMPORTANCE In situ detection of viral mRNA expression in tissue samples is of great value for pathological diagnosis to access viral infection status. Unfortunately, conventional RNA in situ hybridization assays lack sensitivity and specificity for clinical diagnostic purposes. Currently, the commercially available branched DNA technology-based single-molecule RNA in situ detection method offers satisfactory results. Here, we present our padlock probe- and rolling circle amplification-based RNA in situ hybridization assay for detecting HPV E6/E7 mRNA expression in formalin-fixed paraffin-embedded tissue sections, providing an alternative yet robust method for viral RNA in situ visualization that is also applicable to different types of diseases.

Genomic integration and expression of Felis catus papillomavirus type 2 oncogenes in feline Merkel cell carcinoma

The involvement of Felis catus papillomavirus type 2 (FcaPV2) in feline Merkel cell carcinoma (MCC) has been previously hypothesized. In this study, the expression and localization of FcaPV2 oncogene mRNA, the integration of FcaPV2 genes, and p53 mutations in feline MCC were examined by RNAscope in situ hybridization (ISH), whole genome sequencing (WGS), and Sanger DNA sequencing, respectively. Furthermore, the morphological and molecular characteristics of FcaPV2-positive (FMX-MCC01) and FcaPV2-negative (AS-MCC01) MCC cell lines were compared in vitro and in vivo using immunofluorescence, ISH, xenotransplantation into mice, and immunohistochemistry. ISH for FcaPV2 E6/E7 detected viral RNA in 18/21 FcaPV2-positive MCC and not in 1/1 FcaPV2-negative MCC. WGS of 2 FcaPV2-positive cases revealed the integration of FcaPV2 genes in both cases. In cultured cells and xenograft tissues of FMX-MCC01, most cells were positive for E6/E7 by ISH and p16CDKN2A, a few cells were positive for the retinoblastoma protein (pRb), and all cells were negative for p53. In cultured cells and xenograft tissues of AS-MCC01, all cells were negative for p16CDKN2A, most cells were positive for pRb, and some cells were positive for p53. Missense mutations in p53 were identified in 8/10 FcaPV2-positive and 1/1 FcaPV2-negative MCC. These results suggest that the expression of integrated FcaPV2 oncogenes might be associated with reduced expression of the tumor suppressor proteins pRb and p53 and might contribute to the development of feline MCC. On the other hand, p53 mutations may be involved in both FcaPV2-positive and FcaPV2-negative MCC tumorigenesis.

Human papillomavirus-related neoplasia of the ocular adnexa

Human papillomaviruses (HPV) are involved in approximately 5% of solid cancers worldwide. The mucosotropic genotypes infect the stratified epithelium of various locations, where persistent infection may lead to invasive carcinomas. While the causative role of HPV in certain anogenital and head and neck carcinomas is well established, the role of HPV in carcinomas arising in the mucosal membranes of the ocular adnexal tissue (the lacrimal drainage system and the conjunctiva) has been a topic of great uncertainty. Therefore, we conducted a series of studies to assess the correlation between HPV and carcinomas arising in the mucosa of the ocular adnexal tissue and characterize the clinical, histopathological, and genomic features of the tumors in the context of HPV status in a Danish nationwide cohort. We collected clinical and histopathological data and tumor specimens from patients with carcinomas of the conjunctiva and the lacrimal drainage system, and their potential precursors, identified in Danish nationwide registries. The HPV status of the tumors was determined by the combined use of HPV DNA polymerase chain reaction (PCR), HPV E6/E7 mRNA in-situ hybridization, and p16 immunohistochemistry. The genomic profile was investigated by high-throughput DNA sequencing targeting 523 cancer-relevant genes. The literature to date on carcinomas of the lacrimal drainage system and the conjunctiva was summarized. In the Danish cohort, 67% of all carcinomas of the lacrimal drainage system and 21% of all conjunctival carcinomas were HPV-positive. HPV16 was the most frequently implicated genotype. A full-thickness expression of the viral oncogenes E6 and E7 was evident in almost all HPV DNA-positive cases. The HPV-positive carcinomas of the conjunctiva and the lacrimal drainage system shared histopathological and genomic features distinct from their HPV-negative counterparts. The HPV-positive carcinomas were characterized by a non-keratinizing morphology, p16 overexpression, high transcriptional activity of HPV E6/E7, and frequent pathogenic variants in the PI3K-AKT signaling cascade. In contrast, the HPV-negative carcinomas were characterized by a keratinizing morphology, lack of p16 and E6/E7 expression, and frequent somatic pathogenic variants in TP53, CDKN2A, and RB1. Among the patients with conjunctival tumors, HPV positivity was associated with a younger age at diagnosis and a higher risk of recurrence. In conclusion, the results support an etiological role of HPV in a subset of conjunctival and LDS carcinomas and their precursor lesions. Our investigations have shown that the HPV-positive carcinomas of the ocular adnexa share genomic and phenotypic characteristics with HPV-positive carcinomas of other anatomical locations. Therefore, these patients may be eligible for inclusion in future basket trials and future treatment regimens tailored to the more frequently occurring HPV-positive carcinomas of other locations. Future research will further elucidate the diagnostic, prognostic, and predictive role of HPV in these carcinomas.

Clinical, Morphologic, and Molecular Features Associated With Ovarian Metastases From Pattern A Endocervical Adenocarcinomas

Ovarian metastases from endocervical adenocarcinomas (EAs) are rare but well-described. Silva Pattern A tumors have been reported to pose essentially no risk of lymph node metastases or recurrence. We describe a cohort of patients with Silva Pattern A EAs with ovarian metastases, as well as involvement of other sites. Eight pattern A EAs with ovarian metastases (4 synchronous, 4 metachronous) were identified from our institution's pathologic archives (2008-2021). Clinicopathologic and molecular features for each case were recorded. All patients were treated by hysterectomy; in each case, the entire tumor was submitted for histologic evaluation. The synchronous metastases were all clinically suspected to be ovarian primary tumors; EAs with metachronous ovarian involvement were confined to the uterus at initial diagnosis, with ovarian metastasis occurring 5 to 171 months after hysterectomy. Morphologically, all tumors were predominantly gland-forming, 5/8 (63%) displayed prominent mucinous differentiation, and 5/8 (63%) involved the corpus. All EAs were either noninvasive (exophytic/papillary/more complex than adenocarcinoma in situ) or showed nondestructive cervical stromal invasion to a depth of 5 mm or less. In the 5 tumors tested by next-generation sequencing, ARID1A, GNAS, and KRAS mutations were detected in 2 (40%), 3 (60%), and 4 (80%) cases, respectively. All 6 patients with follow-up (range, 32 to 181 mo; median, 99.5 mo) had at least 1 recurrence. All but one are without evident disease at last clinical assessment. In an otherwise typical Silva Pattern A EA, corpus involvement, mucinous differentiation, and certain gene mutations may be associated with risk for synchronous or metachronous ovarian metastases.

Human papillomavirus E6E7 mRNA and TERC lncRNA in situ detection in cervical scraped cells and cervical disease progression assessment

Background

Human papillomavirus screen in female cervical cells has demonstrated values in clinical diagnosis of precancerous lesions and cervical cancers. Human papillomavirus tests of cervical cells by utilizing Polymerase Chain Reaction (PCR) method provides human papillomavirus infection status however no further virus in situ information. Although it is well known that the tests of human papillomavirus E6/E7 RNA location in infected cervical cells and cell internal malignancy molecular will provide clues for gynecologists to evaluate disease progression, there are technique difficulties to preserve RNAs in cervical scraped cells for in situ hybridization.

Methods

In current study, after developing a cervical cell collection and preparation method for RNA in situ hybridization, we captured the chance to screen 98 patient cervical cell samples and detected human papillomavirus E6/E7 mRNAs of high-risk subtypes, low-risk subtypes and long non-coding RNA (lncRNA) TERC in the cells.

Results

There were 69 samples exhibited consistence between human papillomavirus PCR and human papillomavirus RNA in situ hybridization results in cervical collected cells. Among them, 23 were both positive and 46 were both negative. In the rest 29 samples, 8 were HPV RNAscope positive, either high risk or low risk subtypes, however HPV PCR negative. Another 9 samples were HPV PCR results positive whereas RNAscope negative. The last 12 samples were HPV positive detected by both RNAscope and PCR methods, however inconsistent between high-risk and low-risk subtypes. In RNAscope positive samples, viral E6/E7 mRNAs were observed to distribute in cervical scraped cell nucleus and cytoplasm. Moreover, HPV viral RNA gathered clusters were observed outside of cells through human papillomavirus RNA in situ hybridization detection. Varied numbers of human papillomavirus infective cells were detected by RNAscope assay in different patients even though they were all human papillomavirus high-risk subtype positive discovered by human papillomavirus PCR results. A cell malignancy related long non-coding RNA, TERC, has been detected in seven patient samples. The patient follow-up information was further analyzed with RNAscope results which indicated a combination of RNAscope positive signals of TERC and human papillomavirus high risk signals in more than 10 cells (cytoplasm or nucleus) may connect with cervical lesion fast progression which deserves further studies in the future.C

Conclusions

Taken together, current study has provided an observable clue for gynecologists to evaluate human papillomavirus infection stage and cell malignancy status which may contribute for assessment of cervical disease progression.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12985-021-01696-9.

Localization and genotyping of canine papillomavirus in canine inverted papillomas

Numerous canine papillomaviruses (CPVs) have been identified (CPV1-23). CPV1, 2, and 6 have been associated with inverted papillomas (IPs). We retrieved 19 IPs from 3 histopathology archives, and evaluated and scored koilocytes, inclusion bodies, giant keratohyalin granules, cytoplasmic pallor, ballooning degeneration, and parakeratosis. IHC targeting major capsid proteins of PV was performed, and CPV genotyping was achieved by PCR testing. Tissue localization of CPV DNA and RNA was studied by chromogenic and RNAscope in situ hybridization (DNA-CISH, RNA-ISH, respectively). IPs were localized to the limbs (50%), trunk (30%), and head (20%), mainly as single nodules (16 of 19). In 15 of 19 cases, immunopositivity was detected within the nuclei in corneal and subcorneal epidermal layers. PCR revealed CPV1 in 11 IPs and CPV2 DNA in 3 IPs. Overall, 14 of 17 cases were positive by both DNA-CISH and RNA-ISH, in accord with PCR results. A histologic score >5 was always obtained in cases in which the viral etiology was demonstrated by IHC, DNA-CISH, and RNA-ISH. IHC and molecular approaches were useful to ascertain the viral etiology of IPs. Although IHC is the first choice for diagnostic purposes, ISH testing allows identification of PV type and the infection phase. RNA-ISH seems a promising tool to deepen our understanding of the pathogenesis of different PV types in animal species.

Establishment of a Three-Dimensional In Vitro Model of Equine Papillomavirus Type 2 Infection

There is growing evidence that equine papillomavirus type 2 (EcPV2) infection is etiologically associated with the development of genital squamous cell carcinoma (SCC) and precursor lesions in equids. However, the precise mechanisms underlying neoplastic progression remain unknown. To allow the study of EcPV2-induced carcinogenesis, we aimed to establish a primary equine cell culture model of EcPV2 infection. Three-dimensional (3D) raft cultures were generated from equine penile perilesional skin, plaques and SCCs. Using histological, molecular biological and immunohistochemical methods, rafts versus corresponding natural tissue sections were compared with regard to morphology, presence of EcPV2 DNA, presence and location of EcPV2 gene transcripts and expression of epithelial, mesenchymal and tumor/proliferation markers. Raft cultures from perilesional skin harboring only a few EcPV2-positive (EcPV2+) cells accurately recapitulated the differentiation process of normal skin, whilst rafts from EcPV2+ penile plaques were structurally organized but showed early hyperplasia. Rafts from EcPV2+ SCCs exhibited pronounced hyperplasia and marked dysplasia. Raft levels of EcPV2 oncogene transcription (E6/E7) and expression of tumor/proliferation markers p53, Ki67 and MCM7 expression positively correlated with neoplastic progression, again reflecting the natural situation. Three-dimensional raft cultures accurately reflected major features of corresponding ex vivo material, thus constituting a valuable new research model to study EcPV2-induced carcinogenesis.

Clinicopathologic Association and Prognostic Value of MELF Pattern in Invasive Endocervical Adenocarcinoma (ECA) as Classified by IECC

Microcystic, elongated, and fragmented (MELF) pattern of myometrial invasion is correlated with lymphovascular invasion (LVI) and lymph node metastases in uterine endometrioid carcinoma but has not been described in endocervical adenocarcinoma (ECA). A total of 457 ECAs were collected, and clinical/morphologic parameters correlated with follow-up data. Potential associations between MELF pattern and age, human papillomavirus status, tumor size/grade, LVI, lymph node metastases, Silva pattern were analyzed. Statistical analyses of overall survival (OS), disease-free survival, progression-free survival (PFS) were conducted using Kaplan-Meier analysis, and compared using the Log-rank test. Of 292 ECAs analyzed, 94 (32.19%) showed MELF invasion pattern (MELF-positive). Significant statistical correlation was found between MELF-positive and tumor size (P=0.0017), LVI (P=0.007), Silva pattern (P=0.0005); age, human papillomavirus status, tumor grade, lymph node metastases did not correlate. Fifty-five of 292 patients recurred (18.83%): 18/94 (19.14%) MELF-positive, 37/198 (18.68%) MELF-negative. PFS in MELF-positive: 77.2% and 64.5% at 5 and 10 yr, respectively; PFS in MELF-negative: 82% and 68.5% at 5 and 10 yr, respectively. On multivariate analysis for PFS and other prognostic parameters, only LVI was statistically significant (P=0.001). OS in MELF-positive was 86% and 74.1% at 5 and 10 yr, respectively; OS in MELF-negative, was 89.7% and 86% at 5 and 10 yr, respectively. Median survival was worse in MELF-positive (199.8 mo) versus MELF-negative (226.1 mo); this was not statistically significant. On multivariate analysis for OS and other prognostic parameters, only tumor stage was statistically significant (P=0.002). In ECAs, MELF is not independently associated with survival. Pathologic characteristics of MELF-positive (size, LVI, Silva pattern) versus MELF-negative tumors differ significantly.

RNAscope CSF1 chromogenic in situ hybridization: a potentially useful tool in the differential diagnosis of tenosynovial giant cell tumors

Colony stimulating factor-1 (CSF1) upregulation and CSF1/colony-stimulating factor 1 receptor (CSF1R) signaling pathway is central to the tumorigenesis of tenosynovial giant cell tumors (TGCT) of both localized (LTGCT) and diffuse (DTGCT) types, and has been demonstrated in a small number of malignant tumors (MTGCT) as well. In situ hybridization for CSF1 mRNA has been shown to be potentially useful in the diagnosis of TGCT, although only a relatively small number of cases have been studied. We studied CSF1 mRNA expression using RNAscope chromogenic in situ hybridization (CISH) in standard tissue sections from 31 TGCT and 26 non-TGCT, and in tumor microarray slides (Pantomics normal MN0341, Pantomics tumor MTU391, Pantomics melanoma MEL961). Among normal tissues, CSF1 mRNA expression was invariably present in synovium (10/10, 100%) and absent in all other normal tissues. All LTGCT and DTGCT were positive (24/24, 100%), exclusively in large, eosinophilic synoviocytes. MTGCT contained large clusters of CSF1-positive malignant synoviocytes (8/8, 100%); malignant spindled cells were also positive. Among non-TGCT, CSF1 CISH was less often positive with high specificity (90%). CSF1-positive cases included leiomyosarcoma, giant cell tumor of bone and of soft parts, pulmonary carcinoma and others. The sensitivity and specificity of RNAscope CSF1 mRNA CISH for the diagnosis of TGCT were 100% and 90%, respectively. We conclude that RNAscope CSF1 CISH may be a valuable adjunct for the diagnosis of TGCT of all types, especially those with atypical or malignant morphologic features. Detection of CSF1 mRNA expression may also have predictive significance in cases where use of the CSF1 inhibitor pexidartinib is considered.

Genomic Characterization of HPV-related and Gastric-type Endocervical Adenocarcinoma: Correlation With Subtype and Clinical Behavior

The majority of endocervical adenocarcinomas (EAs) are caused by human papillomavirus (HPV). Gastric-type EA, the second most common EA and unrelated to HPV, is biologically different with a more aggressive clinical course. Our knowledge of the molecular fingerprint of these important EA types and its role in diagnosis, prognosis and management is still evolving. Thus, we sought to evaluate the genomic profile of HPV-related and gastric EA. Clinical information including patient outcome was gathered for 56 tumors (45 HPV-associated and 11 gastric-type) surveying evaluated by a targeted massively parallel sequencing assay (OncoPanel platform) which surveys exonic DNA sequences of 447 cancer genes and 191 regions across 60 genes for rearrangement detection. KRAS, TP53, and PIK3CA were the most commonly mutated genes (10, 10, and 9 cases, respectively). Alterations in TP53, STK11, CDKN2A, ATM, and NTRK3 were significantly more common in gastric-type EA (P<0.05, Fisher exact test). Disease recurrence and/or death occurred in 14/49 (29%) cases with clinical information available 7 HPV-related (18% of HPV-related cases with clinical information available) and 7 gastric-type (64% of gastric-type cases with clinical information available). Tumors associated with adverse outcome, regardless of histotype, more commonly had alterations in KRAS (2 HPV-related, 4 gastric-type), GNAS (3 HPV-related, 1 gastric-type), and CDKN2A (0 HPV-related, 3 gastric type) compared with indolent-behaving cases (P<0.05, Fisher exact test). A total of 8/56 (14%) tumors harbored at least one actionable mutation; of these, 6 (75%) were associated with recurrence and/or cancer-related death. Copy number variations were detected in 45/56 cases (80%). The most frequent were chromosome 20 gain and 16q loss, identified in 7 cases each (all HPV-associated EA). The mutational profile of EA is diverse and correlates with clinical behavior and EA subtype. Thus, targeted sequencing assays can potentially serve as a diagnostic and prognostic tool. It can also identify targetable alterations, which may benefit patients with recurrent/metastatic disease.

Accuracy of HPV E6/E7 mRNA examination using in situ hybridization in diagnosing cervical intraepithelial lesions

Background

The consistency of pathologists in the diagnosis of cervical intraepithelial neoplasia (CINs) is not ideal, especially between low- and high-grade squamous intraepithelial lesions (LSIL and HSIL). This study was aimed to explore efficient strategies for the grading of CINs.

Methods

The medical records of patients with high risk human papillomavirus (HR-HPV) infections who had underwent cervical biopsy or conization from April 2018 to April 2019 in Beijing Chao-Yang Hospital were collected and examined. The HR-HPV E6/E7 mRNA in the tissues of patients with CINs was detected using RNAscope chromogenic in situ hybridization (RISH). Immunohistochemistry (IHC) was performed to evaluate the expression of p16INK4a (P16) and Ki67.

Results

HR-HPV E6/E7 mRNA signals were detected in 3/27 (11.1 %) of CIN 1, and in 32/33 (97.0 %) of CIN 2/3. Most of the staining patterns (27/32, 84.4 %) had a full-thickness epithelial layer staining with weak-to-strong nuclear and cytoplasmic dot-like signals in CIN 2/3, and there were also few special staining patterns that were significantly different from the others. A number of indicators were compared between LSIL and HSIL. There were statistically significant differences in E6/E7 mRNA, p16, Ki67 and cytology between the two groups (P < 0.05). According to the logistic regression analysis, merely E6/E7 mRNA positivity was significantly associated with CIN2/3 (OR: 52.53, 95 % CI, P < 0.05). In the detection of CIN 2/3, the sensitivity and specificity of HPV E6/E7 mRNA alone was not significantly inferior to that of its different combinations with Ki67, p16 and cytology (all, P > 0.05).

Conclusions

RISH is efficient in grading of CINs. The HPV E6/E7 mRNA expression might reflect the phase HPV infections, and its positive pattern might predict the development direction of CINs, providing the possibility to realize more accurate treatments for patients.

MEK/ERK signaling is a critical regulator of high-risk human papillomavirus oncogene expression revealing therapeutic targets for HPV-induced tumors

Intracellular pathogens have evolved to utilize normal cellular processes to complete their replicative cycles. Pathogens that interface with proliferative cell signaling pathways risk infections that can lead to cancers, but the factors that influence malignant outcomes are incompletely understood. Human papillomaviruses (HPVs) predominantly cause benign hyperplasia in stratifying epithelial tissues. However, a subset of carcinogenic or “high-risk” HPV (hr-HPV) genotypes are etiologically linked to nearly 5% of all human cancers. Progression of hr-HPV-induced lesions to malignancies is characterized by increased expression of the E6 and E7 oncogenes and the oncogenic functions of these viral proteins have been widely studied. Yet, the mechanisms that regulate hr-HPV oncogene transcription and suppress their expression in benign lesions remain poorly understood. Here, we demonstrate that EGFR/MEK/ERK signaling, influenced by epithelial contact inhibition and tissue differentiation cues, regulates hr-HPV oncogene expression. Using monolayer cells, epithelial organotypic tissue models, and neoplastic tissue biopsy materials, we show that cell-extrinsic activation of ERK overrides cellular control to promote HPV oncogene expression and the neoplastic phenotype. Our data suggest that HPVs are adapted to use the EGFR/MEK/ERK signaling pathway to regulate their productive replicative cycles. Mechanistic studies show that EGFR/MEK/ERK signaling influences AP-1 transcription factor activity and AP-1 factor knockdown reduces oncogene transcription. Furthermore, pharmacological inhibitors of EGFR, MEK, and ERK signaling quash HPV oncogene expression and the neoplastic phenotype, revealing a potential clinical strategy to suppress uncontrolled cell proliferation, reduce oncogene expression and treat HPV neoplasia.

Human papillomavirus (HPV) infections occur in differentiating squamous epithelium and induce hyperplasia during the viral replicative cycle. Although HPV oncogene expression is necessary to promote cellular proliferation for viral genome amplification in the middle epithelial layers, oncogene levels are thereafter suppressed to permit differentiation-induced late gene expression in the uppermost epithelial cells. Yet, the mechanisms responsible for controlling HPV oncogene expression are not well understood. Here, we demonstrate that EGFR/MEK/ERK signaling, which is subject to the normal cellular cues of contact inhibition and epithelial tissue differentiation, is a critical regulator of hr-HPV oncogene expression. We found that extrinsic activation of ERK overrides cellular control to promote oncogene expression and the neoplastic phenotype. Many epidemiologically defined risk factors activate the EGFR/MEK/ERK pathway, suggesting a common mechanism whereby they may promote HPV persistence and disease progression. Lastly, we show that HPV oncogene transcription and protein expression remain susceptible to MEK/ERK control in early neoplastic tissues and tumor cells and that targeted inhibition of MEK/ERK signaling might be exploited therapeutically for HPV-induced infections and tumors.

Correlation between Human Papillomavirus Codetection Profiles and Cervical Intraepithelial Neoplasia in Japanese Women

Human papillomavirus (HPV) infection is thought to be strongly associated with the precarcinomatous state cervical intraepithelial neoplasia (CIN) and cervical carcinoma. To accurately assess the correlation between HPV detection profiles and CIN, the uniplex E6/E7 polymerase chain reaction (PCR) method was used. We detected HPV (37 genotypes) in 267 CIN cases. The detection of a single high-risk HPV genotype occurred in 69.7% of CIN1 and worse than CIN1 (CIN1+) cases whereas other types were detected in 11.6% of cases. Codetection of high-risk HPV genotypes occurred in 4.9% of CIN1+ cases. The high-risk genotype HPV16 was the most frequently detected genotype in CIN1+ lesions; the genotype HPV34 (not a high-risk type) was detected in some CIN3 cases. Furthermore, HPV codetection may not be associated with CIN grades. These results suggest that various HPV genotypes are associated with CIN across all analyzed cases.

Evaluation of human papillomavirus (HPV) prediction using the International Endocervical Adenocarcinoma Criteria and Classification system, compared to p16 immunohistochemistry and HPV RNA in-situ hybridization

Background

The International Endocervical Adenocarcinoma Criteria and Classification (IECC) separated endocervical adenocarcinomas into human papillomavirus (HPV) associated (HPVA) and non–HPV-associated (NHPVA) categories by morphology alone. Our primary objective was to assess the accuracy of HPV prediction by the IECC system compared to p16 immunohistochemistry and HPV RNA in-situ hybridization (RISH). Our secondary goal was to directly compare p16 and HPV RISH concordance.

Methods

Cases were classified by IECC and stained for p16 and HPV RISH on tissue microarray, with discordant p16/HPV RISH cases re-stained on whole tissue sections. Remaining discordant cases (p16/HPV, IECC/p16, IECC/HPV discordances) were re-reviewed by the original pathologists (n = 3) and external expert pathologists (n = 2) blinded to the p16 and HPV RISH results. Final IECC diagnosis was assigned upon independent agreement between all reviewers.

Results

One hundred and eleven endocervical adenocarcinomas were classified originally into 94 HPVA and 17 NHPVA cases. p16 and HPV RISH was concordant in 108/111 cases (97%) independent of the IECC. HPV RISH and p16 was concordant with IECC in 103/111 (93%) and 106/111 (95%), respectively. After expert review, concordance improved to 107/111 (96%) for HPV RISH. After review of the eight discordant cases, one remained as HPVA, four were reclassified to NHPVA from HPVA, two were unclassifiable, and one possibly represented a mixed usual and gastric-type adenocarcinoma.

Conclusions

p16 and HPV RISH have excellent concordance in endocervical adenocarcinomas, and IECC can predict HPV status in most cases. Focal apical mitoses and apoptotic debris on original review led to the misclassification of several NHPVA as HPVA.

Prevalence of Equus caballus Papillomavirus Type-2 Infection and Seropositivity in Asymptomatic Western Canadian Horses

Equus caballus papillomavirus type 2 (EcPV-2) has been recognized as a potential cause of a subset of genital squamous cell carcinomas (SCCs) in horses. In the current study, we measured EcPV-2 seropositivity in 50 healthy horses from Western Canada, and these were compared to a herd of horses with known EcPV-2 exposure. Second, the presence of EcPV-2 DNA was measured using EcPV-2-specific PCR (polymerase chain reaction), performed on a variety of tissues collected at necropsy from 70 horses that lacked any history, gross, or histologic evidence of neoplasia or papillomavirus-associated disease. EcPV-2-specific RNA in situ hybridization (R-ISH) was performed on PCR-positive samples to identify the specific tissues infected. The prevalence of asymptomatic infection with EcPV-2 in Western Canadian horses was 20/70 (29%). Exposure to EcPV-2 as measured by seropositivity was 18/50 (36%). EcPV-2 positivity by anatomic location, as measured by R-ISH, was as follows: penis 10/29 (35%), vulva 5/34 (15%), eyelid 8/68 (12%), oral mucosa 7/65 (11%), skin from muzzle 7/68 (10%), and retropharyngeal lymph node 2/64 (3%). The youngest horses with EcPV-2 infection, based on PCR, were fetuses, suggesting for the first time that vertical transmission of EcPV-2 occurs in horses. The current study observed an increased prevalence of EcPV-2 as compared to previous studies. We suggest that this difference is due to our use of biopsies in place of superficial swabs. We propose that EcPV-2 infection in asymptomatic horses is more common than previously reported and that the virus' role in equine genital SCCs may be more complex than originally thought.

Analysis of factors affecting the prognosis of patients with cervical intraepithelial neoplasia 2

According to the 2014 World Health Organization Classification of Tumors of Female Reproductive Organs, patients with cervical intraepithelial neoplasia 2 (CIN2) have an equivocal diagnosis, but p16 is considered as the reference index for CIN2. Positive p16 expression in CIN2 is associated with high-grade squamous intraepithelial lesions (HSIL), whereas p16 negative lesions are low-grade squamous intraepithelial lesions. The purpose of the present study was to examine the clinical value of p16 and human papillomavirus (HPV) E6/E7 mRNA in the prognostication of patients with CIN2. From January 2013 to January 2016, 108 patients were diagnosed with CIN2 by biopsy and followed up at 6-month intervals at Peking University People's Hospital (Beijing, China). The expression of HPV E6/E7 mRNA was detected by in situ hybridization, while the expression of p16 and Ki-67 proteins was detected by immunohistochemistry. Of the 108 CIN2 cases, 20 progressed to HSIL/CIN3, 36 cases demonstrated persistence with CIN2 after the follow-up and 52 cases achieved regression (≤CIN1). Of the p16-positive 82 cases, 20 cases were detected to have progressed, whereas in the p16-negative group, no progression was observed. There were statistically significant differences among the p16-positive and negative groups (P<0.05). In the HPV E6/E7 mRNA-positive 69 cases, 18 cases were detected to have progressed, whereas in the HPV E6/E7 mRNA-negative 39 cases, progression was detected in only 2 cases. There were statistically significant differences among the HPV E6/E7 mRNA-positive and negative groups (P<0.05). The area under the receiver operating characteristics curve was plotted; the area under the curve for HPV E6/E7 mRNA was 0.745, that for p16 was 0.546 and that for Ki-67 was 0.501. The detection of HPV E6/E7 mRNA may provide important predictive information for the prognosis of CIN2, however p16 and Ki-67 proteins may provide little value.

p16 Positive Histologically Bland Squamous Metaplasia of the Cervix: What does It Signify?

With increasing use of p16 immunohistochemistry (IHC) in diagnosis of premalignant lesions of cervix, we occasionally encounter p16 positivity in squamous metaplasia that lacks morphologic characteristics of "atypical squamous metaplasia" or of squamous intraepithelial lesion (SIL). Our study aims to investigate if transcriptionally active human papilloma virus (HPV) can be identified in such foci and if they have any relationship with squamo-columnar junction (SCJ) cells. Twenty-two cases of cervical specimens with at least a focus of p16 positive bland squamous metaplasia, were selected. HPV E6/E7 mRNA in situ hybridization followed by IHC for CK7 (SCJ biomarker), Ki67, and HPV16 E2, were performed. Follow-up information was obtained. Four cases were excluded due to insufficient tissue. Of the final 18 cases, HPV E6/E7 mRNA in situ hybridization was positive in all. Nine cases showed positivity in >50% cells and the epithelial thickness involved was ≥lower two-thirds in 13 cases. Of the further evaluable 15 cases, CK7 was positive in 14, Ki67 was positive in 10, and HPV16 E2 was negative in all. Concomitant high-grade squamous intraepithelial lesion was identified in 10 cases. On follow-up (duration: 1 to 19 mo), 6 patients showed histologic high-grade squamous intraepithelial lesion. Our study demonstrates that p16 positivity in squamous metaplasia of cervix is associated with the presence of transcriptionally active high-risk HPV even when there are no clear morphologic features of dysplasia. Our results suggest that these lesions are early SILs or SILs that are not yet morphologically evident, most of which arise from SCJ and should be closely followed.

Clinicopathologic Features of Anal and Perianal Squamous Cell Carcinomas and Their Relationship to Human Papillomavirus

Anal squamous cell carcinomas (ASCCs) frequently harbor human papillomavirus (HPV), most commonly high-risk (HR-) HPV type 16. While p16 immunohistochemistry (IHC) is typically used as a surrogate for HR-HPV status in the oropharynx and cervix, its overexpression can also occur as a result of oncogenic stress and sometimes prove nonspecific. There have been recent investigations into the use of HPV RNA in situ hybridization (RISH) assays as an alternative method, which have shown robust results for squamous cell carcinomas of the oropharynx and cervix. Our study evaluated HPV RISH and p16 IHC in 50 ASCCs, as well as the clinicopathologic features of ASCC relative to HPV status. We found that HPV RISH and p16 IHC were closely in agreement with 96% concordance. Using the 2 methodologies, 78% of ASCCs were HR-HPV positive, 10% were low-risk HPV positive, and 12% were HPV-negative. None of our cases showed co-infection across HR-HPV and low-risk HPV. ASCCs that were not related to HR-HPV were more likely to have a typical keratinizing morphology (P=0.05) and more likely to involve the perianal area (P=0.006). HPV-negative cases were particularly aggressive with high rates of metastases and patient death within 2 years of diagnosis. Overall, HPV RISH appears to be a reliable methodology for testing, and HPV status may have implications for prognostication of ASCCs.

Paving the way for more precise diagnosis of EcPV2-associated equine penile lesions

Background

There is growing evidence that equine papillomavirus type 2 (EcPV2) infection is causally associated with the development of equine genital squamous cell carcinomas (SCCs). Early stages of disease present clinically as plaques or wart-like lesions which can gradually progress to tumoural lesions. Histologically these lesions are inconsistently described as benign hyperplasia, papilloma, penile intraepithelial neoplasia (PIN), carcinoma in situ (CIS) or SCC. Guidelines for histological classification of early SCC precursor lesions are not precisely defined, leading to potential misdiagnosis. The aim of this study was to identify histologic criteria and diagnostic markers allowing for a more accurate diagnosis of EcPV2-associated equine penile lesions.

Results

A total of 61 archived equine penile lesions were histologically re-assessed and classified as benign hyperplasia, papilloma, CIS or SCC. From these, 19 representative lesions and adjacent normal skin were comparatively analysed for the presence of EcPV2 DNA and transcripts using PCR and RNA in situ hybridisation (RISH). All lesional samples were positive by EcPV2 PCR and RISH, while adjacent normal skin was negative. RISH analysis yielded signal distribution patterns that allowed distinction of early (hyperplasia, papilloma) from late stage lesions (CIS, SCC). Subsequently, the 19 lesions were further assessed for expression of p53, Ki67, MCM7 and MMP1 by immunohistochemistry (IHC). All four proteins were expressed in both normal and lesional tissue. However, p53 expression was up-regulated in basal keratinocyte layers of papillomas, CIS and SCCs, as well as in upper keratinocyte layers of CIS and SCCs. MCM7 expression was only up-regulated in upper proliferating keratinocyte layers of papillomas, CIS and SCCs.

Conclusion

This study proposes combining a refined histological protocol for analysis of equine penile lesions with PCR- and/or RISH based EcPV2-screening and p53/MCM7 IHC to more accurately determine the type of lesion. This may help to guide the choice of optimum treatment strategy, especially at early stages of disease.

Accuracy of mRNA HPV Tests for Triage of Precursor Lesions and Cervical Cancer: A Systematic Review and Meta-Analysis

OBJECTIVE

This systematic review evaluates the accuracy of the mRNA HPV biomarker in cervical smears to identify cervical intraepithelial neoplasia (CIN) 2 or 3 and cervical cancer.

DATA SOURCE

Eligible studies were identified by performing a search of electronic databases on Medline via Pubmed, Lilacs, Cochrane Library, Embase, and Grey literature for papers published between January 1990 and June 2018.

STUDY ELIGIBILITY CRITERIA

As no randomized studies were identified, this review focuses on observational studies in which the mRNA HPV diagnostic test was compared to a histopathology reference standard. We analyzed studies that included women screened for cervical cancer using mRNA HPV.

STUDY APPRAISAL AND SYNTHESIS METHODS

After screening, 61 studies including 29,674 patients met the inclusion criteria and were analyzed. Dichotomization was performed by defining CIN2 or worse (CIN2+) versus CIN1, HPV infection, and normal (CIN 1-). The analysis was discriminated by the following tests: Aptima, PreTect HPV Profeer, NucliSens EasyQ HPV, OncoTect, and Quantivirus.

RESULTS

Analyzing by technique, Aptima, with 28 studies, exhibited superior performance, showing for the outcomes CIN2+ and CIN3+ an AUC of 0.88 (0.82-0.95) and 0.91 (0.84-0.99), a pooled sensitivity of 92.8% (95%CI 91.9-93.7) and 95.6% (95%CI 94.5-96.5), and a pooled specificity of 60.5% (95%CI 59.8-61.3) and 61.9% (95%CI 61.1-62.7), respectively.

CONCLUSION

This study supports the current hypothesis that the mRNA HPV assay is an adequate tool for secondary cervical cancer screening.

Effect of Progestin Usage on the Interpretation of Cervical High-grade Squamous Intraepithelial Lesion

Progestin usage can alter the histologic and cytologic features of HSIL, which may potentially lead to the under-diagnosis of this precancerous lesion. The objective of the present study was to assess the relationship between the usage of progesterone-based contraceptives and the cytologic features of high-grade squamous intraepithelial lesion (HSIL) of the cervix. In this case-control study, we assembled 46 cases of cervical HSIL (CIN 3), including samples from 26 patients with known history of progestin usage (study group) and 20 samples from patients with no history of any exogenous hormone usage (control group). Cell image analysis was performed on all samples using a proprietary software. Immunohistochemical studies for Ki67, p16, estrogen receptor and progesterone receptor were performed on all cases, as was RNA in situ hybridization for HPV subtypes 16 and 18. Compared with the control group cases, the average nuclear size (21.5±1.80 μm) and the nuclear: cytoplasmic ratio (0.28±0.015) of HSILs in the study group cases were significantly smaller (P=0.026) and reduced (P=0.005), respectively. In addition, the study group cases showed reduced nuclear atypia and pleomorphism and significantly reduced mitotic figures (1.74±1.86/mm in study group versus 5.94±1.3/mm in control group, P<0.0001). The later was likely a consequence of the significantly reduced mitotic figures in the superficial and middle epithelial layers of the study group cases compared with their control group counterparts (0.73±0.88/mm vs. 7.3±2.6/mm, P<0.0001). Progestin usage has no discernible effects on p16 immunoreactivity, Ki67 proliferative index, hormone receptor expression, and HPV RNA levels of HSIL lesions. Being aware of progestin induced morphologic changes on those cervical precancerous lesions will be ultimately improve patient care quality in our daily practice.

Role of Ancillary Techniques in Cervical Biopsy and Endocervical Curettage Specimens as Follow-Up to Papanicolaou Test Results Indicating a Diagnosis of Atypical Squamous Cells, Cannot Exclude High-Grade Squamous Intraepithelial Lesion, or High-Grade Squamous Intraepithelial Lesion

The Papanicolaou (PAP) test is widely used to screen for cervical cancer. All high-grade lesions such as atypical squamous cells, cannot exclude high-grade squamous intraepithelial lesion (ASC-H), and high-grade squamous intraepithelial lesion, identified on a PAP test should be followed-up by a confirmatory cervical biopsy. In this review, we discuss the challenges in interpreting cervical tissue specimens and the various ancillary techniques used in the evaluation of cervical dysplasia. Ancillary studies include deeper levels, p16 immunohistochemistry (IHC), human papillomavirus (HPV) testing, and, importantly, cyto-histologic correlation. Of these, p16 IHC is consistently sensitive and specific for detecting HSIL. HPV RNA in situ hybridization (ISH) is a newer technique with excellent sensitivity and specificity for detecting virally infected cells and it may be more broadly applicable to both low- and high-grade squamous intraepithelial lesions.

HPV E6/E7 mRNA In Situ Hybridization in the Diagnosis of Cervical Low-grade Squamous Intraepithelial Lesions (LSIL)

Cervical low-grade squamous intraepithelial lesions (LSIL) (aka cervical intraepithelial neoplasia, grade 1 [CIN1]) can present considerable diagnostic challenges and are associated with poor interobserver reproducibility and overdiagnosis. Furthermore, ancillary studies such as p16 immunohistochemistry have shown little utility in resolving the LSIL versus negative/reactive differential. Human papillomavirus (HPV) RNA in situ hybridization (ISH) has shown promise as a diagnostic aid in this setting, but has not been studied in a large case series. We herein investigate high-risk and low-risk HPV RNA ISH in 126 cervical biopsies originally diagnosed as LSIL/CIN1 and compare HPV RNA ISH results to expert-adjudicated morphologic diagnosis to assess whether this assay can help routine cases attain the existing "gold standard" of morphologic consensus diagnosis. We also assess whether this criterion standard can be further improved by integration of HPV RNA ISH results. A consensus diagnosis of intraepithelial lesion (CIN1) was confirmed in 61% of cases, whereas 57% were HPV RNA. HPV-RNA positivity was 84% sensitive and 86% specific for an expert-adjudicated diagnosis of CIN1. Conversely, consensus diagnosis was 90% sensitive and 78% specific for the presence of HPV RNA. Integrating RNA ISH into morphologic review led to further reclassification of 10% of cases, resulting in 95% sensitivity and 98% specificity of HPV RNA ISH for a CIN1 diagnosis and 98% sensitivity and 92% specificity of CIN1 for the presence of HPV RNA. These findings suggest that judicious use of HPV RNA ISH can improve the accuracy of LSIL/CIN1 diagnosis for morphologically ambiguous cases.

Putative Role of Circulating Human Papillomavirus DNA in the Development of Primary Squamous Cell Carcinoma of the Middle Rectum: A Case Report

Here we present the case of a patient affected by rectal squamous cell carcinoma in which we demonstrated the presence of Human Papillomavirus (HPV) by a variety of techniques. Collectively, the virus was detected not only in the tumor but also in some regional lymph nodes and in non-neoplastic mucosa of the upper tract of large bowel. By contrast, it was not identifiable in its common sites of entry, namely oral and ano-genital region. We also found HPV DNA in the plasma-derived exosome. Next, by in vitro studies, we confirmed the capability of HPV DNA-positive exosomes, isolated from the supernatant of a HPV DNA positive cell line (CaSki), to transfer its DNA to human colon cancer and normal cell lines. In the stroma nearby the tumor mass we were able to demonstrate the presence of virus DNA in the stromal compartment, supporting its potential to be transferred from epithelial cells to the stromal ones. Thus, this case report favors the notion that human papillomavirus DNA can be vehiculated by exosomes in the blood of neoplastic patients and that it can be transferred, at least in vitro, to normal and neoplastic cells. Furthermore, we showed the presence of viral DNA and RNA in pluripotent stem cells of non-tumor tissue, suggesting that after viral integration (as demonstrated by p16 and RNA in situ hybridization positivity), stem cells might have been activated into cancer stem cells inducing neoplastic transformation of normal tissue through the inactivation of p53, p21, and Rb. It is conceivable that the virus has elicited its oncogenic effect in this specific site and not elsewhere, despite its wide anatomical distribution in the patient, for a local condition of immune suppression, as demonstrated by the increase of T-regulatory (CD4/CD25/FOXP3 positive) and T-exhausted (CD8/PD-1positive) lymphocytes and the M2 polarization (high CD163/CD68 ratio) of macrophages in the neoplastic microenvironment. It is noteworthy that our findings depicted a static picture of a long-lasting dynamic process that might evolve in the development of tumors in other anatomical sites.

International Endocervical Adenocarcinoma Criteria and Classification: Validation and Interobserver Reproducibility

The current World Health Organization (WHO) classification for endocervical adenocarcinoma (EA) is based on descriptive morphologic characteristics; however, it does not fully reflect our current knowledge of the diverse pathogenesis of cervical glandular neoplasia. A novel classification system, the International Endocervical Adenocarcinoma Criteria and Classification (IECC), which incorporates etiology and biological behavior into the morphologic scheme, has been recently proposed. We aimed to validate the IECC by assessing its interobserver reproducibility in comparison to the WHO system. A cohort of 75 EAs was reviewed independently by 7 gynecologic pathologists and categorized following IECC and WHO criteria based on hematoxylin and eosin material alone and after immunohistochemistry results for p16, PR, p53, Napsin-A, vimentin, CDX2, and GATA3 were provided. Human papillomavirus (HPV) in situ hybridization and polymerase chain reaction results were compared with consensus diagnoses. IECC was superior to WHO in terms of interobserver agreement with κ=0.46 versus 0.3, respectively, on hematoxylin and eosin review and κ=0.51 versus 0.33, respectively, with immunohistochemistry. Under the IECC, 73 (97%) of EAs had majority agreement (≥4 reviewers in agreement) whereas 42 (56%) had perfect agreement (7/7 reviewers in agreement). Conversely, WHO showed majority agreement in 56 (75%) and perfect agreement in only 7 (10%) EAs. Reproducibility was poor in HPV-related WHO types (usual κ=0.36, mucinous not otherwise specified κ=0.13, intestinal κ=0.31, villoglandular κ=0.21) and good in major HPV-unrelated categories (gastric type κ=0.63, clear cell κ=0.81, mesonephric κ=0.5). Classification as per the IECC had excellent correlation with HPV status (by RNA in situ hybridization or polymerase chain reaction). We have shown that the IECC has superior interobserver agreement compared with the WHO classification system, and that distinction between HPV-related and HPV-unrelated EA can be made with good reproducibility and excellent prediction of HPV status. WHO morphologic variants of HPV-related EA are poorly reproducible. Conversely, agreement is high among important high-risk HPV-unrelated subtypes. Thus, our results further support replacing the current WHO classification with the IECC.

Disruption of CTCF-YY1-dependent looping of the human papillomavirus genome activates differentiation-induced viral oncogene transcription

The complex life cycle of oncogenic human papillomavirus (HPV) initiates in undifferentiated basal epithelial keratinocytes where expression of the E6 and E7 oncogenes is restricted. Upon epithelial differentiation, E6/E7 transcription is increased through unknown mechanisms to drive cellular proliferation required to support virus replication. We report that the chromatin-organising CCCTC-binding factor (CTCF) promotes the formation of a chromatin loop in the HPV genome that epigenetically represses viral enhancer activity controlling E6/E7 expression. CTCF-dependent looping is dependent on the expression of the CTCF-associated Yin Yang 1 (YY1) transcription factor and polycomb repressor complex (PRC) recruitment, resulting in trimethylation of histone H3 at lysine 27. We show that viral oncogene up-regulation during cellular differentiation results from YY1 down-regulation, disruption of viral genome looping, and a loss of epigenetic repression of viral enhancer activity. Our data therefore reveal a key role for CTCF-YY1-dependent looping in the HPV life cycle and identify a regulatory mechanism that could be disrupted in HPV carcinogenesis.

HPV RNA in situ hybridization can inform cervical cytology-histology correlation

BACKGROUND

In situ hybridization for human papillomavirus (HPV) messenger RNA (HPV RNA ISH) recently was introduced as an ancillary tool in the diagnosis of cervical squamous intraepithelial lesions, and can aid in the distinction between low-grade squamous intraepithelial lesions (LSILs) versus reactive/negative biopsies. Prior work has shown that up to one-half of cases originally diagnosed as LSIL are reclassified as negative/reactive by expert consensus review of morphology, and negative HPV RNA ISH results most often correlate with an expert diagnosis of negative/reactive. Given that LSIL overdiagnoses on biopsy may result in the erroneous clinical impression that a cervical lesion has been sampled appropriately, the authors proposed that HPV RNA ISH can inform cytology-histology correlation for challenging LSIL biopsies.

METHODS

A total of 92 cervical biopsies originally diagnosed as LSIL were reviewed by 3 gynecologic pathologists and reclassified based on consensus opinion of morphology. ISH was performed for high-risk and low-risk HPV E6/E7 mRNA. Prior/concurrent cytology results were collected.

RESULTS

Based on expert consensus morphologic review, 49% of biopsies (45 of 92 biopsies) originally diagnosed as LSIL were reclassified as negative, 6.5% (6 of 92 biopsies) were reclassified as high-grade squamous intraepithelial lesion, and 44.5% (41 of 92 biopsies) were maintained as LSIL. The majority of LSIL biopsies reclassified as negative (80%; 36 of 45 biopsies) were HPV RNA negative, whereas 93% of LSIL biopsies (39 of 41 biopsies) and 100% of high-grade squamous intraepithelial lesion biopsies were HPV RNA positive.

CONCLUSIONS

LSIL often is overdiagnosed by morphology on biopsy, potentially leading to the false impression that a lesion identified on cytology has been sampled. Performing RNA ISH on biopsies decreases histologic LSIL overdiagnosis, and potentially can prompt further sampling when there is cytology-histology discordance. Cancer (Cancer Cytopathol) 2018. © 2018 American Cancer Society.

Stromal invasion pattern identifies patients at lowest risk of lymph node metastasis in HPV-associated endocervical adenocarcinomas, but is irrelevant in adenocarcinomas unassociated with HPV

OBJECTIVE

The Silva invasion pattern-based classification system stratifies endocervical adenocarcinomas (ECAs) into 3 categories corresponding to risk of metastasis and recurrence, but has only been evaluated for HPV-associated ECAs of usual type. We examined whether the Silva system is applicable to all endocervical adenocarcinomas, especially those not associated with HPV.

METHODS

Complete slide sets from 341 surgical specimens of ECA were collected from 7 institutions worldwide. All specimens were associated with clinical records covering at least 5 years of follow-up. Tumors were classified as HPV-associated (HPVA) or not (NHPVA) by both morphology and detection of HPV using in situ hybridization. Recurrence and survival were analyzed by multivariate Mantel-Haenszel methods.

RESULTS

Most specimens (292; 85.6%) were HPVA, while 49 (14.3%) were NHPVA. All NHPVAs were Silva pattern C, while 76.0% of HPVAs were pattern C, 14.7% pattern A, and 9.3% pattern B. Including both HPVAs and NHPVAs, lymphovascular invasion (LVI) was detected in 0% of pattern A, 18.5% of pattern B and 62.6% of pattern C cases (p < 0.001). None of the pattern A or B cases were associated with lymph node metastases (LNM), in contrast to pattern C cases (21.8%). Among patients with Silva pattern C ECA, those with HPVA tumors had a lower recurrence rate and better survival than those with NHPVA; however, when adjusted for stage at diagnosis, the difference in recurrence and mortality was small and not statistically significant.

CONCLUSIONS

Application of the Silva system is only relevant in HPVA cervical adenocarcinoma.

International Endocervical Adenocarcinoma Criteria and Classification (IECC): A New Pathogenetic Classification for Invasive Adenocarcinomas of the Endocervix

We sought to classify endocervical adenocarcinomas (ECAs) based on morphologic features linked to etiology (ie, human papillomavirus [HPV] infection), unlike the World Health Organization 2014 classification. The International Endocervical Adenocarcinoma Criteria and Classification (IECC criteria), described herein, distinguishes between human papillomavirus-associated adenocarcinoma (HPVA), recognized by the presence of luminal mitoses and apoptosis seen at scanning magnification, and no or limited HPVA features (nonhuman papillomavirus-associated adenocarcinoma [NHPVA]). HPVAs were then subcategorized based on cytoplasmic features (mostly to provide continuity with preexisting classification schemes), whereas NHPVAs were subclassified based on established criteria (ie, gastric-type, clear cell, etc.). Complete slide sets from 409 cases were collected from 7 institutions worldwide. Tissue microarrays representing 297 cases were constructed; immunohistochemistry (p16, p53, vimentin, progesterone receptor) and chromogenic in situ hybridization using an RNA-based probe set that recognizes 18 varieties of high-risk HPV were performed to validate IECC diagnoses. The 5 most common IECC diagnoses were usual-type (HPVA) (73% of cohort), gastric-type (NHPVA) (10%), mucinous adenocarcinoma of HPVA type, including intestinal, mucinous not otherwise specified, signet-ring, and invasive stratified mucin-producing carcinoma categories (9%), clear cell carcinoma (NHPVA) (3%) and adenocarcinoma, not otherwise specified (2%). Only 3 endometrioid carcinomas were recognized and all were NHPVA. When excluding cases thought to have suboptimal tissue processing, 90% and 95% of usual-type IECC cases overexpressed p16 and were HPV, whereas 37% and 3% of NHPVAs were p16 and HPV, respectively. The 1 HPV gastric-type carcinoma was found to have hybrid HPVA/NHPVA features on secondary review. NHPVA tumors were larger and occurred in significantly older patients, compared with HPVA tumors (P<0.001). The high-risk HPV chromogenic in situ hybridization probe set had superior sensitivity, specificity, and positive and negative predictive values (0.955, 0.968, 0.992, 0.833, respectively) compared with p16 immunohistochemistry (0.872, 0.632, 0.907, 0.545, respectively) to identify HPV-related usual carcinoma and mucinous carcinoma. IECC reliably segregates ECAs into HPVA and NHPVA types using morphology alone. This study confirms that usual-type ECAs are the most common type worldwide and that mucinous carcinomas comprise a mixture of HPVA and NHPVA, with gastric-type carcinoma being the major NHPVA type. Endometrioid and serous carcinomas of the endocervix are extraordinarily rare. Should clinical outcomes and genomic studies continue to support these findings, we recommend replacement of the World Health Organization 2014 criteria with the IECC 2017.

Localization of Felis catus Papillomavirus Type 2 E6 and E7 RNA in Feline Cutaneous Squamous Cell Carcinoma

Findings from polymerase chain reaction-based methods have suggested a role of Felis catus papillomavirus 2 (FcaPV-2) in the development of feline cutaneous squamous cell carcinoma (SCC). However, because polymerase chain reaction cannot localize deoxyribonucleic acid or ribonucleic acid within the lesion, it is difficult to differentiate a coincidental FcaPV-2 infection and a causative association. Given that a key event in the pathogenesis of human papillomavirus-induced cancer is the expression of viral E6 and E7 oncogenes, localization of FcaPV-2 E6 and E7 transcription within neoplastic cells in feline SCCs would support a causative role for this papillomavirus. Therefore, RNAscope in situ hybridization was used to localize FcaPV-2 E6 and E7 transcripts in 18 formalin-fixed paraffin-embedded samples of cutaneous SCC. Positive signals were present within 5 of 9 samples (56%) from ultraviolet-protected sites and 0 of 9 samples from ultraviolet-exposed sites. In the 4 in situ hybridization-positive samples that contained adjacent hyperplastic skin, hybridization patterns in these regions were characterized by intense nuclear signals within the superficial epidermis and punctate signals within the basal epithelial layers. However, within the 5 SCCs, punctate signals were present within all layers of the epidermis, with progressive loss of intense nuclear signals within the superficial epidermis. This hybridization pattern is consistent with unregulated E6 and E7 transcription and decreased viral replication and is similar to the pattern observed in human papillomavirus-induced cancers as they progress from hyperplastic lesions containing productive infections to nonproductive neoplasms. These findings support a causative role for FcaPV-2 in the pathogenesis of feline SCC.

Diagnostic Efficiency in Digital Pathology: A Comparison of Optical Versus Digital Assessment in 510 Surgical Pathology Cases

Prior work has shown that digital images and microscopic slides can be interpreted with comparable diagnostic accuracy. Although accuracy has been well-validated, the interpretative time for digital images has scarcely been studied and concerns about efficiency remain a major barrier to adoption. We investigated the efficiency of digital pathology when compared with glass slide interpretation in the diagnosis of surgical pathology biopsy and resection specimens. Slides were pulled from 510 surgical pathology cases from 5 organ systems (gastrointestinal, gynecologic, liver, bladder, and brain). Original diagnoses were independently confirmed by 2 validating pathologists. Diagnostic slides were scanned using the Philips IntelliSite Pathology Solution. Each case was assessed independently on digital and optical by 3 reading pathologists, with a ≥6 week washout period between modalities. Reading pathologists recorded assessment times for each modality; digital times included time to load the case. Diagnostic accuracy was determined based on whether a rendered diagnosis differed significantly from the original diagnosis. Statistical analysis was performed to assess for differences in interpretative times across modalities. All 3 reading pathologists showed comparable diagnostic accuracy across optical and digital modalities (mean major discordance rates with original diagnosis: 4.8% vs. 4.4%, respectively). Mean assessment times ranged from 1.2 to 9.1 seconds slower on digital versus optical. The slowest reader showed a significant learning effect during the course of the study so that digital assessment times decreased over time and were comparable with optical times by the end of the series. Organ site and specimen type did not significantly influence differences in interpretative times. In summary, digital image reading times compare favorably relative to glass slides across a variety of organ systems and specimen types. Mean increase in assessment time is 4 seconds/case. This time can be minimized with experience and may be further balanced by the improved ease of electronic chart access allowed by digital slide viewing, as well as quantitative assessments which can be expedited on digital images.

Correlation of Circulating CD64+/CD163+ Monocyte Ratio and stroma/peri-tumoral CD163+ Monocyte Density with Human Papillomavirus Infected Cervical Lesion Severity

HPV infected cervical cells secrete mediators that are gradually changed and have influence on infiltrating M2 phenotypic monocytes in cervical lesions. However, profiles of circulating immune cells in women with cervical lesions and M2 phenotypic monocyte activity in HPV infected cervical lesions are limited. This study aimed to investigate circulating monocyte populations correlated with M2 phenotype density and its activity in HPV infected cervical lesions. HPV DNA was investigated in cervical tissues using PCR. High risk HPV E6/E7 mRNA was detected using in situ hybridization. CD163 immunohistochemical staining was performed for M2 macrophage. CD163 and Arg1 mRNA expression were detected using real-time PCR. Circulating monocyte subpopulations were analyzed using flow cytometry. CD163 and Arg1 mRNA expression were increased according to cervical lesion severity and corresponding with density of M2 macrophage in HSIL and SCC in stroma and peri-tumoral areas. Additionally, the relationship between M2 macrophage infiltration and high risk HPV E6/E7 mRNA expression was found and corresponded with cervical lesion severity. Circulating CD14⁺CD16⁺ and CD14⁺CD163⁺ monocytes were elevated in No-SIL and cervical lesions. Interestingly, CD14⁺CD64⁺ monocyte was greatly elevated in HSIL and SCC, whereas intracellular IL-10⁺ monocytes were not significantly different between cervical lesions. The correlation between increasing ratio of circulating CD64⁺/CD163⁺ monocyte and density of infiltrating CD163⁺ monocytes was associated with severity of HPV infected cervical lesions. The elevated circulating CD64⁺/CD163⁺ monocyte ratio correlates to severity of HPV infected cervical lesions and might be a prognostic marker in cervical cancer progression.

Current and Emerging Molecular Tests for Human Papillomavirus-Related Neoplasia in the Genomic Era

Laboratory tests have a key role in preventing human papillomavirus (HPV)-driven carcinomas and in guiding therapeutic interventions. An understanding of the virology, immunology, and carcinogenesis of HPV is essential for choosing appropriate diagnostic test modalities and developing new and even more effective cancer prevention strategies. HPV infects basal epithelial cells on multiple surfaces and induces carcinoma primarily in the cervix and the oropharynx. HPV types are stratified as high risk or low risk based on their carcinogenic potential. During oncogenesis, HPV interferes with cell cycle regulation and incites DNA damage responses that thwart apoptosis and enable mutations to accumulate. Such mutations are an adverse effect of innate and adaptive antiviral immune responses that up-regulate DNA-editing enzymes, with natural selection of cells having a chromosomally integrated viral genome lacking expression of viral proteins targeted by the immune system. Infected cancers share a similar mutation signature, reflecting the effect of apolipoprotein B mRNA-editing catalytic polypeptide enzyme DNA-editing enzymes. It is feasible that genomic tests for characteristic mutations or methylation signatures, along with tests for dysregulated HPV gene expression, add value in predicting behavior of premalignant lesions. Furthermore, these tumor markers in cell-free DNA of plasma or body fluids may one day assist in early detection or monitoring cancer burden during treatment.

HR-HPV E6/E7 mRNA In Situ Hybridization: Validation Against PCR, DNA In Situ Hybridization, and p16 Immunohistochemistry in 102 Samples of Cervical, Vulvar, Anal, and Head and Neck Neoplasia

Dysregulated expression of oncogenic types of E6 and E7 is necessary for human papillomavirus (HPV)-driven carcinogenesis. An HPV E6/E7 mRNA in situ hybridization (ISH) assay covering 18 common high-risk types ("HR-RISH," aka HR-HPV RNA18 ISH) has not been extensively studied in the anogenital tract or validated on automated technology. We herein compare HR-RISH to DNA polymerase chain reaction (PCR), p16 immunohistochemistry, and a previously available HPV DNA ISH assay in HPV-related anogenital and head and neck (H&N) neoplasia. A total of 102 squamous intraepithelial lesions (16 CIN1, 25 CIN3, 3 AIN1, 12 AIN3, 9 VIN3)/invasive squamous cell carcinomas (17 cervical, 2 anal, 18 H&N) as well as 10 normal and 15 reactive cervix samples were collected. HR-RISH, DNA ISH, and p16 immunohistochemistry were performed on whole formalin-fixed, paraffin-embedded sections. RNA ISH for 6 low-risk HPV types (LR-RISH) was also performed. RNA and DNA ISH assays used automated systems. HR-HPV PCR was performed on morphology-directed formalin-fixed, paraffin-embedded punches. HR-RISH was ≥97% sensitive for PCR+ and p16+ neoplasia, as well as morphologically defined anogenital high grade squamous intraepithelial lesion/invasive squamous cell carcinoma. HR-RISH was also positive in 78% of anogenital low grade squamous intraepithelial lesion, including 81% of CIN1. Furthermore, a subset of PCR-negative/invalid and p16-negative lesions was positive for HR-RISH. Only 1 problematic reactive cervix sample and no normal cervix samples stained. These results demonstrate that HR-RISH is a robust method for the detection of HR-HPV-related neoplasia and provides insight into HPV pathobiology. Performance meets or exceeds that of existing assays in anogenital and H&N lesions and may play a role in resolving diagnostically challenging CIN1 versus reactive cases.

Methylation Status of P16Ink4a in Human Papillomavirus-Associated Cancer of Oral Cavity and Oropharynx in Northeastern Thailand

Background:

Over-expression of p16^INK4a protein is a biomarker for human papillomavirus (HPV)-associated cervical cancer. However, absence of p16^INK4a protein expression in HPV-associated cancer of the oral cavity and oropharynx has been reported. Among a number of possible reasons for this is methylation, which is frequently noted in the promoter region of p16^INK4a and is associated with silencing of the gene and disease severity.

Methods:

We investigated the relationships between p16^INK4a protein expression, HPV infection and methylation status of the p16^INK4a promoter in cancers of the oral cavity and oropharynx. Fifty-three formalin-fixed paraffin-embedded (FFPE) cancer tissue samples from the oral cavity (49 cases) and oropharynx (4 cases) were studied. P16^INK4a protein expression was determined using immunohistochemical staining (IHC). Additional oral tissues lacking squamous intraepithelial lesions (SILs), and cervical tissues with high-level SILs, were used as negative and positive controls, respectively. High-risk HPV infection was detected using HPV E6/E7 mRNA in situ hybridization. Methylation status of the p16^INK4a promoter was investigated using sodium bisulfite treatment and methylation-specific PCR (MS-PCR).

Results:

HPV infection was found in 40.8% (20/49) and 50.0% (2/4) of oral cavity and oropharynx cancers, respectively. Promoter methylation of p16^INK4a occurred in 73.6 % of all cases and differed significantly in frequency between HPV-positive (90.9%, 20/22) and HPV-negative (61.3%, 19/31) samples. Expression of p16^INK4a was found in 35.8% (19/53) and commonly detected in samples with p16^INK4a unmethylation (79.5%). Interestingly, the silencing of p16^INK4a (64.2%, 34/53) was significantly associated with methylation status (91.2%, 31/34), especially in HPV-infected samples in which the p16^INK4a promoter was methylated (52.9%, 18/34).

Conclusions:

This result demonstrated high frequency of p16^INK4a promoter methylation status in HPV-associated HNSCC subsets that could influence the silent p16^INK4a expression and might promote disease severity.

Molecular approaches for HPV genotyping and HPV-DNA physical status

Persistent infection with high-risk human papillomavirus (HPV) genotypes is the leading cause of cervical cancer development. To this end several studies have focused on designing molecular assays for HPV genotyping, which are considered as the gold standard for the early diagnosis of HPV infection. Moreover, the tendency of HPV DNA to be integrated into the host chromosome is a determining event for cervical oncogenesis. Thus, the establishment of molecular techniques was promoted in order to investigate the physical status of the HPV DNA and the locus of viral insertion into the host chromosome. The molecular approaches that have been developed recently facilitate the collection of a wide spectrum of valuable information specific to each individual patient and therefore can significantly contribute to the establishment of a personalised prognosis, diagnosis and treatment of HPV-positive patients. The present review focuses on state of the art molecular assays for HPV detection and genotyping for intra-lesion analyses, it examines molecular approaches for the determination of HPV-DNA physical status and it discusses the criteria for selecting the most appropriate regions of viral DNA to be incorporated in HPV genotyping and in the determination of HPV-DNA physical status.

The low-risk papillomaviruses

Human Papillomavirus (HPV) research has been dominated by the study of a subset of Alpha papillomaviruses that together cause almost 5% of human cancers worldwide, with the focus being on the two most prominent of these (HPV16 and 18). These viruses are referred to as 'high-risk' (hrHPV), to distinguish them from the over 200 prevalent HPV types that more commonly cause only benign epithelial lesions. The 'low-risk' (lrHPV) term used to describe this group belies their cumulative morbidity. Persistent laryngeal papillomas, which occur rarely in children and adults, require regular surgical de-bulking to allow breathing. Such infections are not curable, and despite being caused by HPV11 (a lrHPV) are associated with 1-3% risk of cancer progression if not resolved. Similarly, the ubiquitous Beta HPV types, which commonly cause asymptomatic infections at cutaneous sites, can sometimes cause debilitating papillomatosis with associated cancer risk. Recalcitrant genital warts, which affect 1 in 200 young adults in the general population, and even the ubiquitous common warts and verrucas that most of us at some time experience, cannot be reliably eradicated, with treatment strategies advancing little over the last 100 years. The review highlights molecular similarities between high and low-risk HPV types, and focuses on the different pathways that the two groups use to ensure persistent infection and adequate virus shedding from the epithelial surface. Understanding the normal patterns of viral gene expression that underlie lesion formation, and which also prevent loss of the infected basal cells in established lesions, are particularly important when considering new treatment options. Finally, the common requirement for deregulated viral gene expression and genome persistence in development of cancers, unites both high and low-risk HPV types, and when considered alongside viral protein functions, provides us with a working understanding of the mechanisms that underlie HPV-associated pathology.

HPV16-E2 induces prophase arrest and activates the cellular DNA damage response in vitro and in precursor lesions of cervical carcinoma

Cervical intraepithelial neoplasia (CIN) is caused by human papillomavirus (HPV) infection and is the precursor to cervical carcinoma. The completion of the HPV productive life cycle depends on the expression of viral proteins which further determines the severity of the cervical neoplasia. Initiation of the viral productive replication requires expression of the E2 viral protein that cooperates with the E1 viral DNA helicase. A decrease in the viral DNA replication ability and increase in the severity of cervical neoplasia is accompanied by simultaneous elevated expression of E6 and E7 oncoproteins. Here we reveal a novel and important role for the HPV16-E2 protein in controlling host cell cycle during malignant transformation. We showed that cells expressing HPV16-E2 in vitro are arrested in prophase alongside activation of a sustained DDR signal. We uncovered evidence that HPV16-E2 protein is present in vivo in cells that express both mitotic and DDR signals specifically in CIN3 lesions, immediate precursors of cancer, suggesting that E2 may be one of the drivers of genomic instability and carcinogenesis in vivo.

Two Canine Papillomaviruses Associated With Metastatic Squamous Cell Carcinoma in Two Related Basenji Dogs

Papillomaviruses (PV) are associated with benign mucosal and cutaneous epithelial proliferations. In dogs, PV-associated pigmented plaques and papillomas can undergo malignant transformation, but this is rare, and most cases of canine squamous cell carcinoma do not arise from PV-induced precursor lesions. We describe herein the progression of pigmented plaques to invasive and metastatic squamous cell carcinoma associated with 2 canine papillomaviruses (CPV) in 2 related Basenji dogs. Immunohistochemistry for PV antigen revealed strong nuclear immunoreactivity within keratinocytes from pigmented plaques from both dogs, consistent with a productive viral infection. Polymerase chain reaction (PCR) using degenerate primers for the L1 gene revealed PV DNA sequences from 2 different CPVs. In situ hybridization for CPV revealed strong hybridization signals within the pigmented plaques and neoplastic squamous epithelial cells from both dogs. We report here progression of PV-associated pigmented plaques to metastatic squamous cell carcinoma within 2 Basenji dogs associated with 2 different CPVs.

Linear viral load increase of a single HPV-type in women with multiple HPV infections predicts progression to cervical cancer

Persistent high-risk human papillomavirus (HPV) infection is strongly associated with development of high-grade cervical intraepithelial neoplasia or cancer (CIN3+). In single type infections, serial type-specific viral-load measurements predict the natural history of the infection. In infections with multiple HPV-types, the individual type-specific viral-load profile could distinguish progressing HPV-infections from regressing infections. A case-cohort natural history study was established using samples from untreated women with multiple HPV-infections who developed CIN3+ (n = 57) or cleared infections (n = 88). Enriched cell pellet from liquid based cytology samples were subjected to a clinically validated real-time qPCR-assay (18 HPV-types). Using serial type-specific viral-load measurements (≥3) we calculated HPV-specific slopes and coefficient of determination (R(2) ) by linear regression. For each woman slopes and R(2) were used to calculate which HPV-induced processes were ongoing (progression, regression, serial transient, transient). In transient infections with multiple HPV-types, each single HPV-type generated similar increasing (0.27copies/cell/day) and decreasing (-0.27copies/cell/day) viral-load slopes. In CIN3+, at least one of the HPV-types had a clonal progressive course (R(2)  ≥ 0.85; 0.0025copies/cell/day). In selected CIN3+ cases (n = 6), immunostaining detecting type-specific HPV 16, 31, 33, 58 and 67 RNA showed an even staining in clonal populations (CIN3+), whereas in transient virion-producing infections the RNA-staining was less in the basal layer compared to the upper layer where cells were ready to desquamate and release newly-formed virions. RNA-hybridization patterns matched the calculated ongoing processes measured by R(2) and slope in serial type-specific viral-load measurements preceding the biopsy. In women with multiple HPV-types, serial type-specific viral-load measurements predict the natural history of the different HPV-types and elucidates HPV-genotype attribution.