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

Combined amplification-based single-molecule fluorescence in situ hybridization with immunofluorescence for simultaneous in situ detection of RNAs and proteins

We present a combined amplification-based single-molecule fluorescence in situ hybridization and immunofluorescence (asmFISH-IF) method for the detection of multiple RNAs and proteins simultaneously in cells and formaldehyde-fixed and paraffin-embedded tissue sections. We showed that performing asmFISH before immunofluorescence gives a better IF signal than the opposite. Our asmFISH-IF method could help study the interplay of RNA and protein, helping to understand their functions.

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.

CIN grades possessing different HPV RNA location patterns and RNAscope is helpful tool for distinguishing squamous intraepithelial lesions in difficult cervical cases

BACKGROUND AND OBJECTIVES

The precise grading and characterization of cervical intraepithelial neoplasia (CIN) has been the focus of pathologists for a long time. This study aimed to explore known strategies for the grading of CINs.

METHODS

After routine H&E review, 85 lesions graded CIN 1, 2, or 3 were investigated primarily by HPV RNAscope to detect HR-HPV and LR-HPV, in combination with an HPV-DNA test and P16/Ki67 immunohistochemistry (IHC). Then, the 85 cases were divided into a control group (49 cases) and a test group (36 cases). The former consisted of cases with consistency between morphology, HPV DNA detection and P16/Ki67 IHC. We used them to evaluate HPV RNA distribution patterns in CINs of different grades. The latter were ambiguous cases in which pathologists could not confirm the diagnosis because of inconsistencies between morphology, HPV DNA detection and P16/Ki67 IHC. We reassessed them by comparison to the pattern in the control group.

RESULTS

The expression patterns of HPV mRNA signals were different in different CIN lesions. LSIL/CIN1 lesions were mostly expressed in superficial epithelium with diffuse clustered nuclear or cytoplasmic staining; HSIL/CIN2 were characterised by nuclear/cytoplasmic punctate or diffuse cluster nuclear staining in the mid-surface layer, and scattered nuclear/cytoplasmic punctate staining in basal and parabasal cells; whereas HSIL/CIN3 showed full-thickness nucleus/cytoplasmic scattered staining with a punctate pattern. According to the staining pattern, we corrected the diagnosis of 22 cases (22/36, 61.1%).

CONCLUSION

Because of its distinct location pattern, HPV RNAscope has obvious advantages over the HPV-DNA test, and combined with P16/Ki67 IHC, it can help pathologists correctly grade CIN. In addition, it can effectively discriminate true CIN from normal or CIN mimic lesions, such as immature squamous metaplasia, atrophy, and inflammatory/reactive changes. Therefore, HPV RNAscope is a valuable auxiliary diagnostic test to avoid the overtreatment and undertreatment of CIN lesions.

The Expression of HPV E6/E7 mRNA In Situ Hybridization in HPV Typing-negative Cervical Cancer

High-risk human papillomavirus (HPV) persistent infection is the major tumorigenesis factor for cervical cancer (CC). However, the incidence of HPV-negative CC is 5% to 30% with different HPV detection methods. High-risk HPV E6/E7 mRNA in situ hybridization (RISH) can detect HPV-driven tumors. Our study aimed to explore whether HPV typing-negative CC was caused by HPV infection. The tissues of CC patients with HPV typing results, collected from cervical biopsies, conization, or hysterectomies, were submitted to RISH using RNAscope chromogenicin. Immunohistochemistry was performed to evaluate the expression of p16INK4a and Ki-67. A total of 308 women with HPV typing results were enrolled, and 30 (9.74%) cases of HPV typing were negative. In HPV typing-negative CCs, 28/30 (93.3%) were positive for RISH, which contained 22/22 (100%) squamous cell carcinomas and 6/8 (75%) adenocarcinomas. RISH was positive in 278/278 (100%) HPV typing-positive CCs, which included 232/232 (100%) squamous cell carcinomas and 46/46 (100%) adenocarcinomas. Positive RISH in HPV typing-negative CC was significantly lower than in the HPV typing-positive group ( P =0.002, 95% confidence interval: 0.848-1.027). However, this significant difference only existed in adenocarcinoma. No significant differences were seen in the expression of p16INK4a and Ki-67 (all P >0.05). HPV typing may cause misdiagnosis in 9.74% of CC patients, and HPV E6/E7 mRNA can detect HPV in CC with HPV typing-negative patients. This approach could provide a novel option to accurately detect high-risk HPVs in cervical tumors and help to eliminate the percentage of misdiagnosed HPV-related cases.

Topical 5-Aminolevulinic Acid Photodynamic Therapy for Cervical High-Grade Squamous Intraepithelial Lesions

OBJECTIVE

To evaluate the efficacy of 5-aminolevulinic acid photodynamic therapy (ALA-PDT) in the treatment of high-grade squamous intraepithelial lesions of the cervix (HSIL).

METHODS

This retrospective study included 22 female patients with histologically confirmed HSIL and high-risk human papillomavirus (HR-HPV) infections. Patients were treated with ALA-PDT once a week for a total of 6 times. All patients had a follow-up period of 3 months and 6 months. The assessment of effectiveness of ALA-PDT was performed by ThinPrep cytology test (TCT), HPV DNA assay, HPV E6/E7 mRNA examination, colposcopy, biopsy, and immunohistochemistry detection.

RESULTS

Three months after 5-ALA PDT, the histologic disappearance rate was 81.82% (18/22), while the HPV clearance rate was 54.55% (12/22). At the 6 months checkpoint, the HSIL disappearance rate was 90.91% (20/22) and the HPV clearance rate was 86.36% (19/22). Before PDT, 68.18% of patients (15/22) were confirmed with TCT abnormalities, while only one patient (1/22, 4.55%) was abnormal in the TCT test at 6 months checkpoint. All participants were found HPV E6/E7 mRNA positive initially, while the HPV E6/E7 mRNA negative rate was 90.91% (20/22) at 6 months checkpoint. Additionally, we found a significant difference of the expression of CD4+ & CD8+ T cells and HPV E6 & E7 proteins before ALA-PDT and at 3 months follow-up (P < 0.01). No severe side effects were seen.

CONCLUSIONS

Topical 5-ALA PDT is an effective treatment for cervical HSIL with HR-HPV infection.

Evaluation of HPV E6/E7 mRNA Detection in Clinically Suspected Cases of Cervical Cancer with Abnormal Cytology: Time to Upgrade the Screening Protocols

Background  Human papillomavirus (HPV) E6/E7 mRNA tests determine the oncogenic activity of the virus and represent a good clinical biomarker for predicting the risk of cervical cancer. So, the present study was conducted to know the role of HPV E6/E7 mRNA as a predictive biomarker for cervical carcinoma.

Methodology  The present study was conducted on 55 clinical samples of cervical scrapings and biopsy from the clinically suspected cases (based on signs and symptoms) of cervical cancer having abnormal PAP smear. The samples were processed in three steps—(1) HPV DNA detection, (2) HPV E6/E7 mRNA detection, and (3) histopathological analysis.

Results  Out of a total of 55 patients, 16 (29.09%) were positive for both HPV E6/E7 mRNA and HPV DNA and six were positive for only HPV DNA. So, a total of 22 (40%) patients were positive for HPV DNA. Out of these 22 samples, 10 (45.5%) were of HPV-16, six (27.3%) were of HPV-18, four (18.2%) were of HPV-31, and two (9.1%) were of HPV-45. Out of total 16 patients positive for HPV E6/E7 mRNA, 10 (62.5%) were of genotype 16 and six (37.5%) were of genotype 18. The patients who were found positive for HPV 31 and 45 genotypes did not have E6/E7 mRNA expression. On colposcopic-guided biopsy, among these 16 samples, eight (50%) were diagnosed with invasive squamous cell carcinoma, six (37.5%) with cervical intraepithelial neoplasia grade 3 (CIN3), and two (12.5%) with CIN2. Out of those six patients in whom only HPV DNA was positive, five had normal biopsy findings and one had CIN1.

Conclusion  The present study suggests that HPV E6/E7 mRNA detection could be more reliable than DNA testing for predicting the risk of progression of HPV-induced cervical lesions to cervical carcinoma and it can be used as a non-invasive tool for triage and patient follow-up.

p16 is superior to Stathmin-1 and HSP27 in identifying cervical dysplasia

Background

The aim of this study was to determine how Stathmin-1 and Heat Shock Protein 27 (HSP27) can be used as adjunctive biomarkers to differentiate high-grade dysplasia from benign/reactive lesions in cervical tissues. In addition, we aimed to see if any of these markers can differentiate endometrial from endocervical adenocarcinomas.

Methods

Fifty cases including benign cervical tissue, low-grade squamous intraepithelial lesion (LSIL), high-grade squamous intraepithelial lesion (HSIL), adenocarcinoma in situ of the endocervix, invasive endocervical adenocarcinoma, and endometrial adenocarcinoma were selected. Stathmin-1 and HSP27 immunohistochemistry (IHC) were performed for each case and the results were compared to the previously available p16 IHC stains.

Results

p16 stained positively in 100% of HSIL, endocervical adenocarcinoma in situ, and invasive endocervical cases. Stathmin-1 stained positively in 43% of HSIL and 90% of endocervical adenocarcinoma in situ and all invasive endocervical cases. Stathmin-1 and p16 were negative in all benign cervical samples. Stathmin-1, HSP27, and p16 stained 100% of LSIL cases. HSP27 stained indiscriminately, including 100% of benign cervical tissue. 87% of the endometrial adenocarcinomas stained positively for p16, Stathmin-1, and HSP27.

Conclusion

p16 remains superior to both Stathmin-1 and HSP27 in differentiating dysplasia from benign, reactive changes of the cervix.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13000-021-01144-w.