RNA modifications in gynecological cancer: current status and future directions.

Currently, more than 170 modifications have been identified on RNA. RNA modification mainly regulates RNA splicing, intracellular transport, degradation, translation, and stability. Gynecologic cancer (GC) mainly includes cervical cancer (CCA), ovarian cancer (OC), Endometrial cancer (EMC), among others, is the leading cause of cancer-related death. At present, there is still a lack of effective means to eradicate such diseases, so it is important to conduct more in-depth research on gynecological cancers. Numerous studies have shown that a series of epigenetic changes occur during the development of gynecologic cancer. This article reviews the latest findings on the functional significance of RNA modification in gynecologic cancer and discusses the therapeutic potential of RNA modification-related inhibitors in the treatment of gynecologic cancer.

High-throughput virtual screening to identify potential small molecule inhibitors of the Zα domain of the adenosine deaminases acting on RNA 1(ADAR1).

Changes in RNA editing are closely associated with diseases such as cancer, viral infections, and autoimmune disorders. Adenosine deaminase (ADAR1), which acts on RNA 1, plays a key role in adenosine to inosine editing and is a potential therapeutic target for these various diseases. The p150 subtype of ADAR1 is the only one that contains a Zα domain that binds to both Z-DNA and Z-RNA. The Zα domain modulates immune responses and may be suitable targets for antiviral therapy and cancer immunotherapy. In this study, we attempted to utilize molecular docking to identify potential inhibitors that bind to the ADAR1 Zα domain. The virtual docking method screened the potential activity of more than 100,000 compounds on the Zα domain of ADAR1 and filtered to obtain the highest scoring results.We identified 71 compounds promising to bind to ADAR1 and confirmed that two of them, lithospermic acid and Regaloside B, interacts with the ADAR1 Zα domain by surface plasmonic resonance technique. The molecular dynamics calculation of the complex of lithospermic acid and ADAR1 also showed that the binding effect of lithospermic acid to ADAR1 was stable.This study provides a new perspective for the search of ADAR1 inhibitors, and further studies on the anti-ADAR11 activity of these compounds have broad prospects.

The construction and analysis of tricarboxylic acid cycle related prognostic model for cervical cancer.

Introduction: Cervical cancer (CC) is the fourth most common malignant tumor in term of in incidence and mortality among women worldwide. The tricarboxylic acid (TCA) cycle is an important hub of energy metabolism, networking one-carbon metabolism, fatty acyl metabolism and glycolysis. It can be seen that the reprogramming of cell metabolism including TCA cycle plays an indispensable role in tumorigenesis and development. We aimed to identify genes related to the TCA cycle as prognostic markers in CC. Methods: Firstly, we performed the differential expressed analysis the gene expression profiles associated with TCA cycle obtained from The Cancer Genome Atlas (TCGA) database. Differential gene list was generated and cluster analysis was performed using genes with detected fold changes >1.5. Based on the subclusters of CC, we analysed the relationship between different clusters and clinical information. Next, Cox univariate and multivariate regression analysis were used to screen genes with prognostic characteristics, and risk scores were calculated according to the genes with prognostic characteristics. Additionally, we analyzed the correlation between the predictive signature and the treatment response of CC patients. Finally, we detected the expression of ench prognostic gene in clinical CC samples by quantitative polymerase chain reaction (RT-qPCR). Results: We constructed a prognostic model consist of seven TCA cycle associated gene (ACSL1, ALDOA, FOXK2, GPI, MDH1B, MDH2, and MTHFD1). Patients with CC were separated into two groups according to median risk score, and high-risk group had a worse prognosis compared to the low-risk group. High risk group had lower level of sensitivity to the conventional chemotherapy drugs including cisplatin, paclitaxel, sunitinib and docetaxel. The expression of ench prognostic signature in clinical CC samples was verified by qRT-PCR. Conclusion: There are several differentially expressed genes (DEGs) related to TCA cycle in CC. The risk score model based on these genes can effectively predict the prognosis of patients and provide tumor markers for predicting the prognosis of CC.

PAX1 and SEPT9 methylation analyses in cervical exfoliated cells are highly efficient for detecting cervical (pre)cancer in hrHPV-positive women.

Studies have investigated PAX1 and SEPT methylation were closely associated with cervical cancer. For this study, we verified the expressions of PAX1 and SEPT9 methylation in 236 hrHPV women cervical exfoliated cells by using quantitative methylation-specific PCR and we further explored their diagnostic value in cervical (pre)cancer detection. Our results identified that the methylation rates and levels of PAX1 and SEPT9 increased with cervical lesion severity. For a diagnosis of cervical (pre)cancer, the area under the curve (AUC) of PAX1 methylation was 0.77 (95% CI 0.71-0.83) and the AUC of SEPT9 methylation was 0.86 (95% CI 0.81∼0.90). Analyses of the PAX1 and SEPT9 methylation statuses alone or combined with commonly used tests can efficiently identify cervical (pre)cancer. In particular, SEPT9 methylation might serve as an effective and powerful biomarker for the diagnosis of cervical (pre)cancer and as an alternative triage test in HPV-based cervical (pre)cancer screening programs.Impact StatementWhat is already known on this subject? This subject showed that PAX1 and SEPT9 methylation were closely associated with cervical cancer. The methylation rates and levels of PAX1 and SEPT9 increased with cervical lesion severity and reached a peak in cervical cancer exfoliated cells. We further assessed the diagnostic performances of PAX1 and SEPT9 methylation in cervical cancer screening. In detecting cervical (pre)cancer, the sensitivity values of PAX1 and SEPT9 methylation were up to 61.18% and 82.35%, respectively, and the specificity values of PAX1 and SEPT9 methylation were up to 95.36% and 86.75%, respectively. Moreover, the ROC curve analysis showed AUC values of 0.77 for PAX1 methylation and 0.86 for SEPT9 methylation tests, which were significantly superior to other commonly used tests. These findings suggest that PAX1 and SEPT9 methylation detection may have great clinical potential in cervical cancer screening.What the results of this study add? The rates and levels of PAX1 and SEPT9 methylation increased with the severity of the cervical lesions. For a diagnosis of cervical (pre)cancer, the area under the curve (AUC) of PAX1 methylation was 0.77 (95% CI 0.71-0.83), and the sensitivity and specificity values were 61.18% and 95.36%, respectively. The AUC value of the SEPT9 methylation was 0.86 (95% CI 0.81 ∼ 0.90), and the sensitivity and specificity values were 82.35% and 86.75%, respectively. Compared with the various tests we conducted, the PAX1 methylation showed the highest specificity (95.36%), and the SEPT9 methylation demonstrated the highest accuracy(86.00%).What the implications are of these findings for clinical practice and/or further research? The methylation levels of PAX1 and SEPT9 had a certain predictive effect on the severity of cervical lesions in hrHPV-positive women. In addition, SEPT9 methylation analysis performs better than PAX1 methylation analysis and commonly used tests in cervical exfoliated cells for detecting cervical (pre)cancer in hrHPV-positive women. SEPT9 methylation analysis merits consideration as an effective and objective, alternative triage test in HPV-based cervical (pre)cancer screening programs.

Septin9 DNA methylation as a promising biomarker for cervical cancer.

Aberrant Septin9 methylation in cervical cancer has been rarely studied. We aimed to identify its diagnostic value in cervical cancer using cervical scrapings, and its predictive potential in plasma for pelvic nodal metastasis of cervical cancer. The statuses of methylated Septin9 in fresh cervical lesions and cervical scrapings were first evaluated by using quantitative methylation-specific PCR. Subsequently, the relationship between Septin9 methylation in 113 plasma samples and pelvic nodal metastasis of cervical cancer was evaluated. Methylated Septin9 was detected in all cancerous tissues, but not in cervicitis. The degrees of Septin9 methylation increased with growing severity of cervical lesions in cervical scrapings. The sensitivity of methylated Septin9 was lower than that of cytology, while it yielded a high specificity and area under the curve in detecting high-grade squamous intraepithelial lesion or cervical cancer; and when Septin9 methylation combined with HPV16/18 genotyping, the sensitivity would increase from 70.42% to 82.39%. Plasma-based Septin9 methylation had a high discriminatory power in predicting pelvic nodal metastasis of cervical cancer, with an optimal specificity of 81.48%. In conclusion, we demonstrated methylated Septin9 to be an innovative diagnostic biomarker for cervical cancer and its non-invasive predictive potential in plasma for pelvic nodal metastasis of cervical cancer.Impact statementWhat is already known on this subject? The occurrence of cervical cancer is related to Septin9 methylation. In fresh specimens and cervical scrapings, we found the degrees of methylated Septin9 increased with growing severity of cervical lesions. Compared with HPV16/18 genotyping and cytological detection, Septin9 methylation had a better specificity and AUC in detecting ≥ HSIL. Furthermore, plasma-based Septin9 methylation also had a high specificity for pelvic lymphatic metastasis prediction.What the results of this study add? Methylation analysis of Septin9 indicated a similar sensitivity, specificity and AUC in detecting ≥ HSIL, relative to HPV16/18 genotyping. Compared with cytological method, Septin9 methylation also yielded a higher specificity and AUC in detecting ≥ HSIL. And we also found plasma-based Septin9 methylation had a high discriminatory power in predicting pelvic nodal metastasis of cervical cancer, with an optimal specificity of 81.48%; additionally an increasing sensitivity from 50% to nearly 80% was found when combined with SCCAg.What the implications are of these findings for clinical practice and/or further research? This study aimed to evaluate the relationship between Septin9 methylation and cervical cancer, and to explore the value of methylated Septin9 in the detection of cervical (pre)cancerous lesions. Moreover, we would explore plasma-based ctDNA biomarkers for pelvic lymphatic metastasis prediction of cervical cancer, to improve non-invasive predictive accuracy of pelvic nodal metastasis and reduce the complications caused by pelvic lymphadenectomy.

Yeast YPK9 deficiency results in shortened replicative lifespan and sensitivity to hydrogen peroxide.

YPK9/YOR291W of Saccharomyces cerevisiae encodes a vacuolar membrane protein. Previous research has suggested that Ypk9p is similar to the yeast P5-type ATPase Spf1p and that it plays a role in the sequestration of heavy metals. In addition, bioinformatics analysis has suggested that Ypk9p is a homolog of human ATP13A2, which encodes a protein of the subfamily of P5 ATPases. However, no specific function of Ypk9p has been described to date. In this study, we found, for the first time, that YPK9 is involved in the oxidative stress response and modulation of the replicative lifespan (RLS). We found that YPK9 deficiency confers sensitivity to the oxidative stress inducer hydrogen peroxide accompanied by increased intracellular ROS levels, decreased mitochondrial membrane potential, abnormal mitochondrial function, and increased incidence of early apoptosis in budding yeast. More importantly, YPK9 deficiency can lead to a shortened RLS. In addition, we found that overexpression of the catalase-encoding gene CTA1 can reverse the phenotypic abnormalities of the ypk9Δ yeast strain. Collectively, these findings highlight the involvement of Ypk9p in the oxidative stress response and modulation of RLS.

Biological effects of NODAL on endometrial cancer cells and its underlying mechanisms.

Activin A receptor type 1C (ALK7) and its ligand nodal growth differentiation factor (NODAL) serve numerous roles in cancer cells, including regulating cancer invasion, migration and apoptosis. NODAL promotes breast cancer cell apoptosis by activating ALK7; however, ALK7 and NODAL expression in endometrial cancer (EC), as well as their effects and underlying mechanisms in EC cells, are not completely understood. The present study aimed to characterize the expression of NODAL and ALK7 in EC, as well as the underlying mechanisms. The expression levels of ALK7 and NODAL were detected via reverse transcription-quantitative PCR and western blotting. Cell transfection was performed to overexpress NODAL or interfere ALK7. Cell proliferation, invasion and migration were detected via Cell Counting Kit-8, Transwell and wound healing assays, respectively. Flow cytometry was performed to detect cell apoptosis and western blotting was conducted to detect the expression levels of apoptosis-related proteins. NODAL and ALK7 expression levels were significantly decreased in EC cell lines compared with normal endometrial cells. NODAL overexpression inhibited EC cell proliferation, invasion and migration, and promoted EC cell apoptosis compared with the overexpression-negative control (Ov-NC) group. Moreover, NODAL overexpression significantly increased ALK7 expression levels in EC cells compared with the Ov-NC group. ALK7 reversed NODAL overexpression-mediated inhibition of EC cell proliferation, invasion and migration, and promotion of EC cell apoptosis. The present study indicated that NODAL inhibited EC cell proliferation, invasion and migration, and promoted EC cell apoptosis by activating ALK7.

Yeast molecular chaperone gene SSB2 is involved in the endoplasmic reticulum stress response.

The Saccharomyces cerevisiae chaperone gene SSB2 belongs to the Hsp70 family. Unlike other HSP70 genes, SSB2 gene expression is reduced after heat shock. It has been reported that Ssb2p can be cross-linked to ribosome-bound nascent polypeptide chains, suggesting a potential role of SSB2 in the endoplasmic reticulum (ER) stress response. In this study, SSB2-deletion and SSB2-overexpression yeast strains were generated and applied to explore the potential mechanism by which SSB2 is involved in the tunicamycin (TM)-induced ER stress response. We demonstrate for the first time that SSB2 deficiency results in reduced resistance to TM, while overexpression of SSB2 increases resistance to TM in an IRE1-HAC1 pathway-dependent manner; these observations are related to changes in intracellular unfolded protein response activities (under the TM-stressed condition). Additionally, SSB2 deletion induces early apoptosis and it may play a causal role in the shortened replicative life span of ssb2Δ mutants observed in this study. These findings highlight the involvement of SSB2 in ER stress responses and ageing in yeast.

The clinical significance of FAM19A4 methylation in high-risk HPV-positive cervical samples for the detection of cervical (pre)cancer in Chinese women.

BACKGROUND: To explore the diagnostic value of FAM19A4 methylation in high-risk human papilloma virus (hrHPV)-positive cervical samples from Chinese women for estimating cervical cancer or its precancerous lesions. METHODS: Cervical samples from 215 women infected with high-risk HPV were collected by smear testing. We purposely chose 61 patients with cervical cancer, 57 with high-grade squamous intraepithelial lesions (HSIL), 31 with low-grade squamous intraepithelial lesions (LSIL), and 66 without cervical intraepithelial neoplasia (CIN) after histological confirmation. Taqman probe-based quantitative PCR (qPCR) was utilized to detect the methylation status of FAM19A4 in the cervical samples and further evaluate the use of this gene in the diagnosis of cervical cancer. RESULTS: (1) An increasing level of FAM19A4 methylation was detected with increasing progression of cervical lesions, with methylation rates of 10.61%(7/66), 35.48%(11/31), 56.14%(32/57) and 93.44%(57/61) in no CIN, LSIL, HSIL and cervical carcinoma samples respectively. (2) In all hrHPV-positive samples, the levels of FAM19A4 methylation in HPV16/18 groups were higher than that in 12 other hrHPV groups (P < 0.05), but there was no significant difference between two groups after grouping cervical lesions into cervical cancer, HSIL, LSIL and no CIN groups (P>0.05). (3)There were no significant differences of FAM19A4 methylation in different clinicopathological parameters of cervical cancer. (4) Though the sensitivity of FAM19A4 methylation test was inferior to that of cytology and FAM19A4 combining with HPV16/18 genotyping, but showed the best specificity with 81.44% both for detection HSIL alone and ≥ HSIL, with favorable youden index (YI) and area under curve (AUC). CONCLUSION: FAM19A4 is a specific biomarker of cancerous lesions of the cervix. FAM19A4 methylation analysis may serve as an auxiliary screening method for diagnosis of cervical (pre)cancer. However, in consideration of the limitations of this retrospective study, prospective population-based studies are necessary for further confirmation of the diagnostic value of FAM19A4 methylation for detection of cervical (pre)cancer in Chinese women.

CTT1 overexpression increases the replicative lifespan of MMS-sensitive Saccharomyces cerevisiae deficient in KSP1.

Ksplp is a nuclear-localized Ser/Thr kinase that is not essential for the vegetative growth of yeast. A global gene function analysis in yeast suggested that Ksplp was involved in the oxidative stress response; however, the underlying mechanism remains unclear. Here, we showed that KSP1-deficient yeast cells exhibit hypersensitivity to the DNA alkylating agent methyl methanesulphonate (MMS), and treatment of the KSP1-deficient strain with MMS could trigger abnormal mitochondrial membrane potential and up-regulate reactive oxygen species (ROS) production. In addition, the mRNA expression level of the catalase gene CTT1 (which encodes cytosolic catalase) and total catalase activity were strongly down-regulated in the KSP1-deleted strain compared with those in wild-type cells. Moreover, the KSP1 deficiency also leads to a shortened replicative lifespan, which could be restored by the increased expression of CTT1. On the other hand, KSP1-overexpressed (KSP1OX) yeast cells exhibited increased resistance towards MMS, an effect that was, at least in part, CTT1 independent. Collectively, these findings highlight the involvement of Ksplp in the DNA damage response and implicate Ksplp as a modulator of the replicative lifespan.

The MBD4 Glu346Lys polymorphism is associated with the risk of cervical cancer in a Chinese population.

OBJECTIVE: Methyl-CpG binding domain 4 (MBD4) protein functions as a DNA repair enzyme and plays an important role in maintaining genome integrity and carcinogenesis. The polymorphisms in the MBD4 gene may be associated with differences in DNA repair capacity and thereby influence an individual's susceptibility to cervical cancer. To verify this hypothesis, we examined the potential association between the MBD4 Glu346Lys polymorphism (rs140693, G>A) and the risk of cervical cancer in a Chinese population. METHODS: We genotyped the MBD4 Glu346Lys polymorphism in 146 cervical cancer cases and 320 healthy female subjects using polymerase chain reaction-based restriction fragment length polymorphism method. Unconditional logistic regression analysis was used to estimate the association between the genotypes and the risk of cervical cancer. RESULTS: We observed a significantly decreased risk of cervical cancer associated with the heterozygous Lys/Glu genotype (odds ratio [OR], 0.60; 95% confidence interval [CI], 0.36-0.99; P = 0.046) and the homozygous Glu/Glu genotype (OR, 0.52; 95% CI, 0.30-0.89; P = 0.018), compared with the Lys/Lys homozygotes. Moreover, the reduced cervical cancer risk was more predominant among younger subjects or human papillomavirus-positive individuals carrying Glu/Glu genotypes (OR, 0.33; 95% CI, 0.14-0.78, P = 0.011; and OR, 0.27; 95% CI, 0.09-0.75, P = 0.013, respectively). CONCLUSIONS: The MBD4 codon 346 polymorphism may play a role in cervical cancer susceptibility in the Chinese population. Further larger case-control and functional studies are needed to validate these findings.

A single nucleotide polymorphism in EXO1 gene is associated with cervical cancer susceptibility in Chinese patients.

OBJECTIVE: The aim of this study was to investigate the association of Exonuclease1 (EXO1) genetic polymorphism and the development of cervical carcinoma. METHODS: This study was conducted with 126 patients diagnosed with cervical cancer and 278 people with no cancer history. The polymerase chain reaction-based restriction fragment length polymorphism was used to evaluate the K589E and C908G gene polymorphisms. Unconditional logistic regression analysis was used to estimate the association between the genotypes and the risk for cervical cancer. RESULTS: This is the first study on the role of EXO1 K589E (rs1047840) and EXO1 C908G (rs10802996) polymorphisms in cervical cancer in a Chinese population. Our results indicated that the EXO1 K589G polymorphism were significantly associated with the risk for cervical cancer. Compared with the G allele EXO1 K589E, the A allele increased the risk for cervical cancer (adjusted odds ratio, 1.67; 95% confidence interval, 1.13-2.45). By contrast, we have not found a significant association between the EXO1 C908G polymorphism and cervical cancer risk (P = 0.791). CONCLUSION: These findings indicate that the SNPs of EXO1 K589E may contribute to cervical cancer carcinogenesis in Chinese populations. A larger population study will need to be carried out to further validate the potential association of EXO1 genetic polymorphism and cervical carcinoma.