Asia oceania guidelines for the implementation of programs for cervical cancer prevention and control

A cyclic peptide-based PROTAC induces intracellular degradation of palmitoyltransferase and potently decreases PD-L1 expression in human cervical cancer cells

Introduction

Our previous research has found that degradation of palmitoyltransferase in tumor cells using a linear peptide PROTAC leads to a significant decrease in PD-L1 expression in tumors. However, this degradation is not a sustained and efficient process. Therefore, we designed a cyclic peptide PROTAC to achieve this efficient anti-PD-L1 effect.

Methods

We designed and synthesized an improvement in linear peptide PROTAC targeting palmitoyltransferase DHHC3, and used disulfide bonds to stabilize the continuous N- and C-termini of the peptides to maintain their structure. Cellular and molecular biology techniques were used to test the effect of this cyclic peptide on PD-L1.

Results

In human cervical cancer cells, our cyclic peptide PROTAC can significantly downregulate palmitoyl transferase DHHC3 and PD-L1 expressions. This targeted degradation effect is enhanced with increasing doses and treatment duration, with a DC50 value much lower than that of linear peptides. Additionally, flow cytometry analysis of fluorescence intensity shows an increase in the amount of cyclic peptide entering the cell membrane with prolonged treatment time and higher concentrations. The Cellular Thermal Shift Assay (CETSA) method used in this study indicates effective binding between our novel cyclic peptide and DHHC3 protein, leading to a change in the thermal stability of the latter. The degradation of PD-L1 can be effectively blocked by the proteasome inhibitor MG132. Results from clone formation experiments illustrate that our cyclic peptide can enhance the proliferative inhibition effect of cisplatin on the C33A cell line. Furthermore, in the T cell-C33A co-culture system, cyclic peptides target the degradation of PD-L1, thereby blocking the interaction between PD-L1 and PD-1, and promoting the secretion of IFN-γ and TNF-α in the co-culture system supernatant.

Conclusion

Our results demonstrate that a disulfide-bridged cyclic peptide PROTAC targeting palmitoyltransferase can provide a stable and improved anti-PD-L1 activity in human tumor cells.

The Role and Applications of Exosomes in Gynecological Cancer: A Review

Exosomes are phospholipid bilayer vesicles that are released by all types of cells, containing proteins, lipids, and nucleic acids such as DNAs and RNAs. Exosomes can be transferred between cells and play a variety of physiological and pathological regulatory functions. Noncoding RNAs, including micro RNAs, long noncoding RNAs, and circular RNAs, are the most studied biomolecules from exosomes and more and more studies found that noncoding RNAs play an important role in the diagnosis, prognosis, and treatment of diseases, including various types of cancer. Gynecological malignancies such as ovarian, endometrial, and cervical cancer seriously threaten women's life. Therefore, this article reviews the roles and applications of exosomes in gynecological malignancies, including the promotion or inhibition of tumor progression and regulation of tumor microenvironments, and as potential therapeutic targets for treating gynecological cancers.

Statins as Repurposed Drugs in Gynecological Cancer: A Review

Discovering new drugs is an expensive and time-consuming process, including target identification, bioavailability, pharmacokinetic (PK) tests, pharmacodynamic (PD) tests, toxicity profiles, recommended dosage test, and observation of the side effects, etc. Repurposed drugs could bypass some steps, starting from phase II trials, and shorten the processes. Statins, also known as HMG-CoA inhibitors (HMGCR), are commonly used to manage and prevent various cardiovascular diseases and have been shown to improve the morbidity and mortality of patients. In addition to the inhibitory effects on the production of cholesterol, the beneficial effects of statins on the prognosis and risk of various cancers are also shown. Statins not only inhibited cell proliferation, metastasis, and chemoresistance but affected the tumor microenvironment (TME). Thus, statins have great potential to be repurposed in oncology. Hence, we review the meta-analysis, cohort, and case-control studies of statins in gynecological cancers, and elucidate how statins regulate cell proliferation, apoptosis, tumor growth, and metastasis. Although the results in gynecological cancers remain controversial and the effects of different statins in different histotypes of gynecological cancers and TME are needed to elucidate further, statins are excellent candidates and worthy of being repurposed drugs in treating gynecological cancers.

Cervical cancer screening guidelines and screening practices in 11 countries: A systematic literature review

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Screening guidelines and practices are heterogenous across 11 countries researched.

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Differences persist between screening guidelines and practices within countries.

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Only 6 of 11 countries here examined have national screening registries in place.

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Robust data infrastructure is essential to evaluate screening performance.

The World Health Organization (WHO) advocates population-based screening programs to reduce the global incidence of cervical cancer. However, screening guidelines and practice continually change to reflect scientific developments. Here we describe and compare cervical cancer screening guidelines and clinical practice in 11 countries across North America, Europe, and Asia-Pacific. We conducted a systematic literature review (SLR) complemented by a targeted literature review (TLR) to identify relevant peer-reviewed publications and policy documents, which include 120 publications, of which 86 were identified from the SLR and 34 from the TLR. Only six of 11 countries assessed have population-based screening programs in place. Considerable differences persist across countries’ screening guidelines, even among comparable systems. Moreover, methods of data collection are also heterogenous, and systematic data collection is often not established. As future changes in screening guidelines and clinical practice occur (e.g., when the first cohorts of women vaccinated against HPV reach screening age), systematic collection of screening data is essential to monitor and improve screening performance.

The feasibility of new HPV/DNA test as a primary cervical cancer screening method among 35- years- old ever-married women in Kalutara district; a cross-sectional study

Background

Cervical cancer is the second commonest female cancer in Sri Lanka. Two major drawbacks of the present cervical cancer screening programme are the suboptimal sensitivity of the pap smear and the low coverage. The objective of the study is to determine the feasibility of a new HPV/DNA test among 35 -years -old ever-married women in a district of Sri Lanka.

Method

A community based descriptive cross-sectional study was conducted from 1^stof July 2018 to 30th November 2018 in the public health divisions called Medical Officer of Health (MOH) areas of Kalutara district. The study population is comprised of ever-married women 35 years of age. Three women from each cluster (n = 413) were selected by consecutive sampling. A total of 918 women were recruited. HPV/DNA cervical specimen collection (n = 822) was carried out. Cervical specimens were tested by two cytoscreeners with the cobas 4800 PCR based screening machine. Clients’ perceptions and prevalence were assessed. The follow-up of women with positive HPV/DNA screening results was carried out. The operational and technical feasibility of the screening test were assessed. Data entry was done by using the statistical package IBM SPSS version 20.

Results

Overall response rate was 91.1% (n = 836). Clients’ perception was highly positive for HPV/DNA screening test procedure (99.9%, n = 821) and 99.6% (n = 819) of clients had mentioned that the HPV/DNA screening test is worthwhile to be incorporated into the National Cervical Cancer Screening program. The prevalence of HPV was 6.2% (95%CI: 6.18–6.22%). The coverage of the HPV/DNA screening was 89.5%(n = 822). Invalid results reported were 0.12% (n = 1). The percentage of HPV/DNA test positive women who underwent pap test within 3 months of the initial screening was 100% (n = 51), while the percentage of women who attempted to get a colposcopy within the 1 month of referral was 86.7% (n = 13).

Conclusions

HPV/DNA test implementation as a primary cervical cancer screening method is feasible among the 35- year age cohort of ever- married women in Kalutara district. It is necessary to further attempt alternative methods of cobas 4800 HPV/DNA test, which would be much suitable for resource-limited settings.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12889-021-10190-4.

Combined clinical and genetic testing algorithm for cervical cancer diagnosis

Background

Opportunistic screening in hospitals is widely used to effectively reduce the incidence rate of cervical cancer in China and other developing countries. This study aimed to identify clinical risk factor algorithms that combine gynecologic examination and molecular testing (paired box gene 1 (PAX1) or zinc finger protein 582 (ZNF582) methylation or HPV16/18) results to improve diagnostic accuracy.

Methods

The delta Cp of methylated PAX1 and ZNF582 was obtained via quantitative methylation-specific PCR in a training set (57 CIN2− and 43 cervical intraepithelial neoplasia ≥grade 3 (CIN3+) women), and the individual and combination gene sensitivities and specificities were determined. The detection accuracy of three algorithms combining gynecologic findings and genetic test results was then compared in a randomized case-control study comprising 449 women referred for colposcopic examination by gynecologists in the outpatient department of Xiangya Hospital between November 2011 and March 2013.

Results

Significant association was observed between CIN3+ and methylated PAX1 or ZNF582 in combination with HPV16/18 (OR:15.52, 95 % CI:7.73–31.18). The sensitivities and specificities of methylated PAX1 or ZNF582 combined with HPV16/18 for CIN3+ women were 89.2 and 76.0 %, or 85.4 and 80.1 %, respectively. Of the three algorithms applied to cohort data and validated in the study, two indicated 100 % sensitivity in detecting cervical cancer and a low rate of referrals for colposcopy.

Conclusions

These algorithms might contribute to precise and objective cervical cancer diagnostics in the outpatient departments of hospitals in countries with high mortality and low screening rates or areas with uneven resource distribution.

Electronic supplementary material

The online version of this article (doi:10.1186/s13148-016-0232-3) contains supplementary material, which is available to authorized users.

Mapping HPV Vaccination and Cervical Cancer Screening Practice in the Pacific Region-Strengthening National and Regional Cervical Cancer Prevention

OBJECTIVE

To provide background information for strengthening cervical cancer prevention in the Pacific by mapping current human papillomavirus (HPV) vaccination and cervical cancer screening practices, as well as intent and barriers to the introduction and maintenance of national HPV vaccination programmes in the region.

MATERIALS AND METHODS

A cross-sectional questionnaire-based survey among ministry of health officials from 21 Pacific Island countries and territories (n=21).

RESULTS

Cervical cancer prevention was rated as highly important, but implementation of prevention programs were insufficient, with only two of 21 countries and territories having achieved coverage of cervical cancer screening above 40%. Ten of 21 countries and territories had included HPV vaccination in their immunization schedule, but only two countries reported coverage of HPV vaccination above 60% among the targeted population. Key barriers to the introduction and continuation of HPV vaccination were reported to be: (i) Lack of sustainable financing for HPV vaccine programs; (ii) Lack of visible government endorsement; (iii) Critical public perception of the value and safety of the HPV vaccine; and (iv) Lack of clear guidelines and policies for HPV vaccination.

CONCLUSION

Current practices to prevent cervical cancer in the Pacific Region do not match the high burden of disease from cervical cancer. A regional approach, including reducing vaccine prices by bulk purchase of vaccine, technical support for implementation of prevention programs, operational research and advocacy could strengthen political momentum for cervical cancer prevention and avoid risking the lives of many women in the Pacific.

Comparison of HPV genotyping and methylated ZNF582 as triage for women with equivocal liquid-based cytology results

Introduction

The interpretation of equivocal Papanicolaou (Pap) smear results remains challenging, even with the addition of the high-risk human papillomavirus test (HPV-HR). Recently, methylated zinc finger protein 582 (ZNF582) (ZNF582^m) was reported to be highly associated with cervical cancer. In this study, we compared the performance of ZNF582^m detection and HPV-HR genotyping in the triage of cervical atypical squamous cell of undetermined significance (ASC-US) and atypical squamous cell - cannot exclude a high-grade lesion (ASC-H).

Case description

Two hundred and forty-two subjects with equivocal papanicolaou smear (Pap smear) results were recruited in this hospital-based and case-controlled study. The residual cervical cells in liquid-based cytological test (LBC) containers were used for genomic DNA extraction and then for ZNF582^m and HPV-HR detection. The level of ZNF582^m was quantified by real-time methylation-specific PCR after bisulfite conversion. The HPV-HR test was performed by using a nested multiplex PCR (NMPCR) assay that combines degenerate E6/E7 consensus primers and HPV type-specific primers.

Discussion and evaluation

Significant associations were observed between ZNF582^m and the risk of cervical intraepithelial neoplasia grade 3 or higher (CIN3+; odds ratio = 15.52, 95% confidence interval (CI): 7.73 to 31.18). The sensitivity and specificity of ZNF582^m for women with CIN3+ were 82.43% and 76.79%, respectively. High sensitivity (99.33%) but low specificity (38.76%) was observed for HPV-HR. When combining both positive results of ZNF582^m and HPV-HR, the sensitivity and specificity were 82.43% and 81.55%, respectively. The sensitivity and specificity of ZNF582^m or HPV-16/18 were 89.19% and 70.24%, respectively. However, the sensitivity and specificity of ZNF582^m combined with HPV-16/18 (both ZNF582^m and HPV-16/18 positive results) were 59.46% and 94.64%, respectively.

Conclusions

ZNF582^m provides a promising triage tool for women with ASC.

To effectively manage ASC patients, a new strategy co-testing for ZNF582^m and HPV-16/18 genotyping was proposed. This strategy could reduce the number of patients referred for colposcopic examination and thus provide a feasible follow-up solution in the regions where colposcopy is not readily available. This strategy could also prevent women from experiencing unnecessary anxiety caused by HPV-HR.

Cervical cancer burden and prevention strategies: Asia Oceania perspective

The Asia Oceania region contributes to more than 50% of cervical cancer cases worldwide. Yet cervical cancer is one of few cancers that can be prevented through comprehensive screening for precancerous lesions, with their subsequent treatment. Screening with cervical cytology, a very old technology, has reduced cervical cancer mortality and incidence when applied in comprehensive programs with high coverage and high quality assurance. However, of those countries within this region that have set up such programs, many have been opportunistic, had poor coverage, or inadequate treatment facilities for lesions found. Consequently, they have not seen large reductions in cancer incidence or mortality. Some have therefore adopted visual inspection by acetic acid (VIA) and Lugol's iodine (VILI) or human papillomavirus (HPV) DNA assays for screening. With two safe, immunogenic and efficacious prophylactic vaccines licensed, the way forward to reduction of cervical cancer to becoming uncommon is within reach. Where governments have supported high coverage public-health vaccination programs, reductions in disease burden with shortest incubation (genital warts, high-grade abnormalities) are already being reported. One of the biggest impediments is the cost of vaccines that are affordable to resource-poor countries. Other challenges include, infrastructure for delivery of vaccines, plus general acceptance of vaccination by the community.