APOBEC3G is increasingly expressed on the human uterine cervical intraepithelial neoplasia along with disease progression

Evaluation of CD4+ cells infiltration as a prognostic factor in cervical intraepithelial neoplasia 2

OBJECTIVE

To identify candidate predictors for the prognosis of cervical intraepithelial neoplasia 2 (CIN2) lesions and evaluate the prognostic value of the local immune response.

METHODS

One hundred fifteen CIN2 patients were enrolled. The percentage of p16-, minichromosome maintenance complex component 2- or apolipoprotein B mRNA editing enzyme catalytic subunit 3G (APOBEC3G)-positive cells was determined immunohistochemically. Tumor-infiltrating lymphocytes (TILs) in intertumoral lesions were scored using an automated system. CIN3 disease progression and regression rates were estimated by the Kaplan-Meier method. A case-control study was conducted to screen CIN2 prognostic factors in 10 regression and 10 progression patients. Selected factors were examined in a cohort study to determine their prognostic value for CIN2.

RESULTS

Among all participants, the cumulative progression and regression rates at 60 months were 0.477 and 0.510, respectively. In the case-control study, p16- and APOBEC3G-positive cells were higher in the progression group (p=0.043, p=0.023). Additionally, CD4⁺ cell infiltration was enhanced in the regression group (p=0.023). The cohort study revealed a significantly increased progression rate in patients with elevated p16-positive cells (p<0.001), and increased CD4⁺ TIL infiltration was associated with better regression (p=0.011). Kaplan-Meier analysis according to human papillomavirus (HPV) positivity revealed a greater CIN3 development risk in HPV16-positive patients than in HPV16-negative cases. Finally, multivariate analysis identified HPV16 infection and CD4⁺ TIL infiltration as independent prognostic factors in CIN2 regression.

CONCLUSION

CD4⁺ TIL infiltration in intertumoral lesions was related with CIN2 regression. Our findings suggest CD4⁺ TIL infiltration may be useful for the triage of CIN2 patients.

FOXP4 inhibits squamous differentiation of atypical cells in cervical intraepithelial neoplasia via an ELF3-dependent pathway

Although the human papillomavirus (HPV) vaccine is effective for preventing cervical cancers, this vaccine does not eliminate pre‐existing infections, and alternative strategies have been warranted. Here, we report that FOXP4 is a new target molecule for differentiation therapy of cervical intraepithelial neoplasia (CIN). An immunohistochemical study showed that FOXP4 was expressed in columnar epithelial, reserve, and immature squamous cells, but not in mature squamous cells of the normal uterine cervix. In contrast with normal mature squamous cells, FOXP4 was expressed in atypical squamous cells in CIN and squamous cell carcinoma lesions. The FOXP4‐positive areas significantly increased according to the CIN stages from CIN1 to CIN3. In monolayer cultures, downregulation of FOXP4 attenuated proliferation and induced squamous differentiation in CIN1‐derived HPV 16‐positive W12 cells via an ELF3‐dependent pathway. In organotypic raft cultures, FOXP4‐downregulated W12 cells showed mature squamous phenotypes of CIN lesions. In human keratinocyte‐derived HaCaT cells, FOXP4 downregulation also induced squamous differentiation via an ELF3‐dependent pathway. These findings suggest that downregulation of FOXP4 inhibits cell proliferation and promotes the differentiation of atypical cells in CIN lesions. Based on these results, we propose that FOXP4 is a novel target molecule for nonsurgical CIN treatment that inhibits CIN progression by inducing squamous differentiation.

Uterine Deletion of Bmal1 Impairs Placental Vascularization and Induces Intrauterine Fetal Death in Mice

Recently, it was demonstrated that the expression of BMAL1 was decreased in the endometrium of women suffering from recurrent spontaneous abortion. To investigate the pathological roles of uterine clock genes during pregnancy, we produced conditional deletion of uterine Bmal1 (cKO) mice and found that cKO mice could receive embryo implantation but not sustain pregnancy. Gene ontology analysis of microarray suggested that uterine NK (uNK) cell function was suppressed in cKO mice. Histological examination revealed the poor formation of maternal vascular spaces in the placenta. In contrast to WT mice, uNK cells in the spongiotrophoblast layer, where maternal uNK cells are directly in contact with fetal trophoblast, hardly expressed an immunosuppressive NK marker, CD161, in cKO mice. By progesterone supplementation, pregnancy could be sustained until the end of pregnancy in some cKO mice. Although this treatment did not improve the structural abnormalities of the placenta, it recruited CD161-positive NK cells into the spongiotrophoblast layer in cKO mice. These findings indicate that the uterine clock system may be critical for pregnancy maintenance after embryo implantation.

Time-Restricted Feeding Regulates Circadian Rhythm of Murine Uterine Clock

BACKGROUND

Skipping breakfast is associated with dysmenorrhea in young women. This suggests that the delay of food intake in the active phase impairs uterine functions by interfering with circadian rhythms.

OBJECTIVES

To examine the relation between the delay of feeding and uterine circadian rhythms, we investigated the effects of the first meal occasion in the active phase on the uterine clock.

METHODS

Zeitgeber time (ZT) was defined as ZT0 (08:45) with lights on and ZT12 (20:45) with lights off. Young female mice (8 wk of age) were divided into 3 groups: group I (ad libitum consumption), group II (time-restricted feeding during ZT12-16, initial 4 h of the active period), and group III (time-restricted feeding during ZT20-24, last 4 h of the active period, a breakfast-skipping model). After 2 wk of dietary restriction, mice in each group were killed at 4-h intervals and the expression profiles of uterine clock genes, Bmal1 (brain and muscle aryl hydrocarbon receptor nuclear translocator-like protein 1), Per1 (period circadian clock 1), Per2, and Cry1 (cryptochrome 1), were examined.

RESULTS

qPCR and western blot analyses demonstrated synchronized circadian clock gene expression within the uterus. Immunohistochemical analysis confirmed that BMAL1 protein expression was synchronized among the endometrium and myometrium. In groups I and II, mRNA expression of Bmal1 was elevated after ZT12 at the start of the active phase. In contrast, Bmal1 expression was elevated just after ZT20 in group III, showing that the uterine clock rhythm had shifted 8 h backward. The changes in BMAL1 protein expression were confirmed by western blot analysis.

CONCLUSIONS

This study is the first to indicate that time-restricted feeding regulates a circadian rhythm of the uterine clock that is synchronized throughout the uterine body. These findings suggest that the uterine clock system is a new candidate to explain the etiology of breakfast skipping-induced uterine dysfunction.

Sulforaphane Inhibits the Expression of Long Noncoding RNA H19 and Its Target APOBEC3G and Thereby Pancreatic Cancer Progression

Pancreatic ductal adenocarcinoma (PDAC) is extremely malignant and the therapeutic options available usually have little impact on survival. Great hope is placed on new therapeutic targets, including long noncoding RNAs (lncRNAs), and on the development of new drugs, based on e.g., broccoli-derived sulforaphane, which meanwhile has shown promise in pilot studies in patients. We examined whether sulforaphane interferes with lncRNA signaling and analyzed five PDAC and two nonmalignant cell lines, patient tissues (n = 30), and online patient data (n = 350). RT-qPCR, Western blotting, MTT, colony formation, transwell and wound healing assays; gene array analysis; bioinformatics; in situ hybridization; immunohistochemistry and xenotransplantation were used. Sulforaphane regulated the expression of all of five examined lncRNAs, but basal expression, biological function and inhibition of H19 were of highest significance. H19 siRNA prevented colony formation, migration, invasion and Smad2 phosphorylation. We identified 103 common sulforaphane- and H19-related target genes and focused to the virus-induced tumor promoter APOBEC3G. APOBEC3G siRNA mimicked the previously observed H19 and sulforaphane effects. In vivo, sulforaphane- or H19 or APOBEC3G siRNAs led to significantly smaller tumor xenografts with reduced expression of Ki67, APOBEC3G and phospho-Smad2. Together, we identified APOBEC3G as H19 target, and both are inhibited by sulforaphane in prevention of PDAC progression.

Activation-induced cytidine deaminase is a possible regulator of cross-talk between oocytes and granulosa cells through GDF-9 and SCF feedback system

Activation-induced cytidine deaminase (AID, Aicda) is a master gene regulating class switching of immunoglobulin genes. In this study, we investigated the significance of AID expression in the ovary. Immunohistological study and RT-PCR showed that AID was expressed in murine granulosa cells and oocytes. However, using the Aicda-Cre/Rosa-tdRFP reporter mouse, its transcriptional history in oocytes was not detected, suggesting that AID mRNA in oocytes has an exogenous origin. Microarray and qPCR validation revealed that mRNA expressions of growth differentiation factor-9 (GDF-9) in oocytes and stem cell factor (SCF) in granulosa cells were significantly decreased in AID-knockout mice compared with wild-type mice. A 6-h incubation of primary granuloma cells markedly reduced AID expression, whereas it was maintained by recombinant GDF-9. In contrast, SCF expression was induced by more than threefold, whereas GDF-9 completely inhibited its increase. In the presence of GDF-9, knockdown of AID by siRNA further decreased SCF expression. However, in AID-suppressed granulosa cells and ovarian tissues of AID-knockout mice, there were no differences in the methylation of SCF and GDF-9. These findings suggest that AID is a novel candidate that regulates cross-talk between oocytes and granulosa cells through a GDF-9 and SCF feedback system, probably in a methylation-independent manner.

Prognostic implication and functional annotations of APOBEC3G expression in patients with Melanoma

Aim: Skin cutaneous melanoma (SKCM) is one of the most life-threatening malignancies damaging human health. APOBEC3G (A3G) has been found in several cancers; however, the role of A3G in SKCM is rarely studied. This study aimed to investigate the expression of A3G in tumor tissue and its prognostic value in SKCM patients.

Method: A total of 512 SKCM patients from the First Affiliated Hospital of Soochow University (FAHSU) and the Cancer Genome Atlas (TCGA) database were consecutively recruited in analyses. Differential transcriptional and proteome expression profiles were obtained from multiple datasets. GEPIA was used to assess the survival analysis between distinguished groups. Both univariate and multivariate Cox regression analysis was performed to address the influence of independent factors on disease-free survival (RFS) and overall survival (OS). In addition, 31 SKCM and 31 nevus tissues were collected for immunohistochemical (IHC) staining and evaluation. STRING, DAVID and Gene Set Enrichment Analysis (GSEA) was utilized to conduct a network of related genes and significant pathways. Furthermore, we investigated the relationship of A3G with tumor-infiltrating immune cells (TIICs) by TIMER and TISIDB.

Result: We found both transcriptional and proteomics expressions of A3G were elevated in SKCM. Survival analysis and ROC curves showed significant diagnostic and prognostic ability of A3G. IHC results showed increased expression of A3G in SKCM compared to nevus tissues. Importantly, A3G expression was closely associated with the immune-infiltrating levels of B cells, CD4+ T, CD8+ T, neutrophils, macrophages and dendritic cells.

Conclusion: In summary, our study first reveals that elevated A3G expression is significantly correlated with better prognosis in SKCM patients. The role of A3G in SKCM demonstrated that it might be a prognostic and immunotherapeutic biomarker for SKCM.

Correlation of APOBEC3G Polymorphism with Human Papillomavirus (HPV) Persistent Infection and Progression of Cervical Lesions

BACKGROUND We studied the effect of APOBEC3G on persistent human papillomavirus (HPV) infection and the correlation between APOBEC3G polymorphism and HPV persistent infection and cervical disease progression in Uygur women in China. MATERIAL AND METHODS From January 2015 to December 2017, we enrolled 529 Uygur ethnic group patients with HPV infection. SIHA cells were transfected with APOBEC3G. Real-time quantitative polymerase chain reaction (RT-qPCR) and Western blot analysis were used to detect mRNA and protein expression levels of APOBEC3G and HPV E6 and p53. Exon 3 of APOBEC3G was sequenced by first-generation sequencing. RESULTS The mRNA and protein expression levels of APOBEC3G in the cervical cancer group were significantly higher than in the cervical intraepithelial neoplasia (CIN) group (p<0.05). The mRNA and protein expression levels of APOBEC3G in the CIN group were significantly higher than in the non-cervical lesions group (p<0.05). The mRNA and protein expression levels of HPV E6 in SIHA cells transfected with APOBEC3G were significantly lower than in the control group and the no-load group (p<0.05), and the mRNA and protein expression levels of p53 were significantly higher than in the control group and the no-load group (p<0.05). There was a polymorphic locus rs5757465 on exon 3 of APOBEC3G in Uygur women, and this rare CC type was a risk factor for cervical lesions and cervical cancer (OR=3.714, 95%CI: 1.916-7.202, p<0.05). CONCLUSIONS APOBEC3G is involved in continuous HPV infection, cervical prelesions, and the development of cervical cancer, and the rare genotype (CC) of APOBEC3G may be one of the factors causing cervical lesions in Uygur women who have HPV infection.

Amniotic epithelial cells damage by oxidative stress in cases of diffuse chorioamniotic hemosiderosis

The amniotic membrane plays an important role in the physiological maintenance and protection of the embryo. Indeed, dysfunction of the amniotic membrane is thought to have an adverse effect on the continuation of pregnancy. In this report, we examined the pathological changes in the amniotic epithelium in three cases of diffuse chorioamniotic hemosiderosis (DCH) and investigated the cause of necrosis of the amniotic epithelial cells and its relationship with oligohydramnios. Diffuse chorioamniotic hemosiderosis was confirmed in all three cases. More extensive amniotic epithelial necrosis led to more severe hemosiderosis. Immunostaining for 8-hydroxy-2'-deoxyguanosine, a marker of oxidative stress, was positive in the amniotic epithelial cells. We speculate that oxidative DNA damage of the amniotic epithelium occurs by decomposition products of blood cells in cases accompanying subchorionic hematomas and pathological DCH. Furthermore, disorder of the amniotic epithelium may disrupt the balance of the amniotic fluid volume and cause oligohydramnios.

Time Restriction of Food Intake During the Circadian Cycle Is a Possible Regulator of Reproductive Function in Postadolescent Female Rats

BACKGROUND

We previously reported that skipping breakfast is associated with menstrual disorders of female college students during postadolescent maturation.

OBJECTIVE

In this study, we investigated the effects of meal timing during circadian cycle on the ovarian function using young female rats.

METHODS

Considering that rats are nocturnally active, 8-wk-old female Wistar rats were classified into 3 groups: fed during the daytime only (nonactive phase), night-time only (active phase), or control group I (without time or calorie restriction, free access to a standard caloric diet, 20.0% protein, 62.9% carbohydrate, and 7.0% fat, 3.95 kcal/g) for 4 wk. The changes in body weight and frequency of ovulation in each group were evaluated by a weight scale and a vaginal smear, respectively. At the end of the period of dietary restriction, ovaries were removed, and the numbers of growing follicles (mean diameter >250 µm) and corpora lutea (>600 µm) were examined using hematoxylin-eosin-stained tissue sections. In addition, 8-wk-old female rats were fed only during the night-time for 4 wk under a 20%-reduced food supply of the control group II (without any restriction).

RESULTS

In the daytime-fed group, the frequency and number of ovulations were significantly decreased compared with those in the control group I (P < 0.05), with a reduced body weight gain concomitant with about 20% of reduction in the daily food intake. In contrast, in the night-time-fed group, even when a 20% reduction in the daily food intake was loaded, their estrus cyclicity did not change despite significant reductions in weight gain and food intake compared with control group II.

CONCLUSION

These findings indicate that restricting food intake to the inactive phase impairs ovarian function in postadolescent female rats, suggesting that the timing of food intake during circadian cycle is one of the crucial factors interfering with the reproductive function.

APOBEC3B Activity Is Prevalent in Urothelial Carcinoma Cells and Only Slightly Affected by LINE-1 Expression

The most common mutational signature in urothelial carcinoma (UC), the most common type of urinary bladder cancer is assumed to be caused by the misdirected activity of APOBEC3 (A3) cytidine deaminases, especially A3A or A3B, which are known to normally restrict the propagation of exogenous viruses and endogenous retroelements such as LINE-1 (L1). The involvement of A3 proteins in urothelial carcinogenesis is unexpected because, to date, UC is thought to be caused by chemical carcinogens rather than viral activity. Therefore, we explored the relationship between A3 expression and L1 activity, which is generally upregulated in UC. We found that UC cell lines highly express A3B and in some cases A3G, but not A3A, and exhibit corresponding cytidine deamination activity in vitro. While we observed evidence suggesting that L1 expression has a weak positive effect on A3B and A3G expression and A3B promoter activity, neither efficient siRNA-mediated knockdown nor overexpression of functional L1 elements affected catalytic activity of A3 proteins consistently. However, L1 knockdown diminished proliferation of a UC cell line exhibiting robust endogenous L1 expression, but had little impact on a cell line with low L1 expression levels. Our results indicate that UC cells express A3B at levels exceeding A3A levels by far, making A3B the prime candidate for causing genomic mutations. Our data provide evidence that L1 activation constitutes only a minor and negligible factor involved in induction or upregulation of endogenous A3 expression in UC.