Hypermethylation and loss of retinoic acid receptor responder 1 expression in human choriocarcinoma

Background

Human placental development resembles tumorigenesis, due to the invasive and fusogenic potential of trophoblasts. However, these features are tightly controlled in trophoblasts. Disturbance of this spatial and temporal regulation is thought to contribute to the rare formation of choriocarcinomas. Promoter hypermethylation and loss of the tumor suppressor Retinoic acid receptor responder 1 (RARRES1) were shown to contribute to cancer progression. Our study investigated the epigenetic and transcriptional regulation of RARRES1 in healthy human placenta in comparison to choriocarcinoma cell lines and cases.

Methods

Three choriocarcinoma cell lines (Jeg-3, JAR and BeWo) were treated with three different retinoic acid derivates (Am580, Tazarotene and all-trans retinoic acid) and 5-aza-2′-deoxycytidine. We analyzed RARRES1 promoter methylation by pyrosequencing and performed realtime-PCR quantification to determine RARRES1 expression in placental tissue and trophoblastic cell lines. Additionally, RARRES1 was stained in healthy placentas and in biopsies of choriocarcinoma cases (n = 10) as well as the first trimester trophoblast cell line Swan71 by immunofluorescence and immunohistochemistry.

Results

In the choriocarcinoma cell lines, RARRES1 expression could not be induced by sole retinoic acid treatment. Stimulation with 5-aza-2′-deoxycytidine significantly induced RARRES1 expression, which then could be further increased with Am580, Tazarotene and all-trans retinoic acid. In comparison to healthy placenta, choriocarcinoma cell lines showed a hypermethylation of the RARRES1 promoter, which correlated with a reduced RARRES1 expression. In concordance, RARRES1 protein expression was lost in choriocarcinoma tissue. Additionally, in the trophoblastic cell line Swan71, we found a significant induction of RARRES1 expression with increased cell density, during mitosis and in syncytial knots.

Conclusions

Our findings showed that RARRES1 expression is absent in choriocarcinoma due to promoter methylation. Based on our analysis, we hypothesize that RARRES1 might exert tumor suppressive functions in multiple cellular processes (e.g. cell cycle regulation, adhesion, invasion and apoptosis).

Electronic supplementary material

The online version of this article (10.1186/s13046-017-0634-x) contains supplementary material, which is available to authorized users.

Contribution of different placental cells to the expression and stimulation of antimicrobial proteins (AMPs)

The placenta is a major barrier that prevents potentially infectious agents from causing fetal diseases or related complications during pregnancy. Therefore, we postulated that the placenta might express a broad repertoire of antimicrobial proteins as well as inflammatory chemokines and cytokines to combat invading microorganisms. Here we demonstrate that placental cells indeed express a wide range of AMPs (antimicrobial peptides and proteins) including bactericidal/permeability-increasing protein (BPI), secretory leukocyte protease inhibitor (SLPI), human β-defensin 2 (hBD2), acyloxyacyl hydrolase (AOAH), and cathelicidin (CAP18). In addition, these cells also secrete pro-inflammatory cytokines and chemokines upon stimulation with bacterial ligands. Notably, we show that BPI expression by placental cells could be completely attributed to granulocytes while highly purified placental trophoblasts expressed only a subset of the AMPs like SLPI. Unexpectedly, trophoblast AMPs did not exhibit inducible secretion in response to various TLR ligands and further investigations showed that the unresponsiveness of trophoblasts to lipopolysaccharide (LPS) was due to a lack of TLR4 expression. In summary, we have shown that the expression of different AMPs can be allocated to various cells in the placenta and the repertoire of the AMPs expressed by placental cells is a result of a cooperation of leukocytes as well as cells from embryonic origin.

Assessment of pituitary and steroid hormones and members of the TGF-beta superfamily for ovarian function in patients with congenital uterus and vaginal aplasia (MRKH syndrome)

Patients with Mayer-Rokitanski-Kuster-Hauser (MRKH) syndrome have congenital uterine and vaginal aplasia. The main question of this study was, if the absence of a uterus along with other genital and organ malformations could contribute to hormone or other growth factor protein fluctuations involved in communication between the hypothalamus-pituitary axis, ovaries and uterus. Serum from 56 MRKH patients (mean 27.6 years) and 22 female controls (mean 30.7 years) were analyzed using ELISA to determine levels of pituitary and steroid hormones (LH, FSH, estradiol, progesterone), growth factors of the TGF-beta superfamily like activin A, inhibin B, and anti-Müllerian hormone (AMH). All serum levels were analyzed in relation to other organ malformations. Compared to controls, all 56 patients, including 5% with streak ovaries or unilateral ovarian aplasia, were generally similar in hormone and growth factor levels and could be grouped into hormonal phases. However, compared to controls LH/FSH and FSH/LH ratios of patients had significantly higher and lower mean values, of 2.75-fold (p=0.015) and 1.9-fold (p=0.002), respectively. Undetectable inhibin B levels of<10 pg/ml (p=0.05) were noted in 41.1% of MRKH patients, resulting in significantly higher activin A/inhibin B ratios (p<0.001). MRKH patients have hormonal phases supporting ovarian function, but patients with low FSH/LH ratios and undetectable inhibin B levels (<10 pg/ml) could represent cycle phasing irregularities. A model is discussed regarding our findings and the loss of ovarian-uterine communication.

Single nucleotide polymorphism D1853N of the ATM gene may alter the risk for breast cancer

PURPOSE

Various ATM (ataxia telangiectasia-mutated) mutations and polymorphisms have been reported to be associated with an increased breast cancer risk. Recent studies have produced contradictory results regarding the association between ATM genetic variants and breast cancer risk.

MATERIALS AND METHODS

The common ATM polymorphism 5557G>A (p.D1853N) (rs1801516), previously suggested to be associated with bilateral breast cancer, was analyzed using real-time PCR in 514 unselected patients with breast cancer and 511 age-matched healthy control individuals. DNA was obtained from peripheral blood draw.

RESULTS

The ATM genotype was weakly associated with the risk for breast cancer (P = 0.04 for the overall test). The odds ratio for women with a heterozygous genotype was 0.70 (95% CI, 0.52-0.94) and for the homozygous variant 0.63 (95% CI, 0.27-1.49). Disease-free survival and overall survival showed no significant association with specific genotypes.

CONCLUSIONS

The results of this study might suggest a minor association between polymorphism 5557G>A and a reduced risk of breast cancer.

Correlations between anti-müllerian hormone, inhibin B, and activin A in follicular fluid in IVF/ICSI patients for assessing the maturation and developmental potential of oocytes

OBJECTIVE

The objective of the present study was to evaluate the correlation between anti-müllerian hormone (AMH), inhibin B, and activin A in follicular fluid from patients receiving treatment with in-vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI), to identify a parameter to assess the maturation and developmental potential of oocytes. -

MATERIALS AND METHODS

AMH, inhibin B, and activin A were measured in follicular fluid from 27 patients undergoing IVF/ICSI treatment for male-factor infertility, tubal occlusion, endometriosis, or anovulation. The values were correlated with the serum estradiol level, the numbers and maturation of the oocytes, and the outcome of IVF/ICSI. -

RESULTS

A positive correlation was found between AMH in follicular fluid and the number of oocytes retrieved. High inhibin B levels in follicular fluid and high serum E subset2 levels indicated a normal ovarian response to stimulation, corresponding to the oocyte numbers, while low inhibin B and 17-beta-estradiol (E subset2) levels indicated poor responders to stimulation. An activin A/inhibin B ratio of less than 1 and very high inhibin B levels correlated with large numbers of oocytes, while a ratio of 1-2 and high inhibin levels correlated with regular numbers of oocytes. An activin/inhibin ratio of more than 3 and low inhibin levels were found in poor responders. Pregnancies occurred predominantly in the group with a normal or high response. Patients with elevated ratios for 17-beta-estradiol/AMH, oocyte numbers/AMH, and metaphase II oocyte numbers/AMH had the best chances of becoming pregnant, indicating an inverse correlation between AMH and the maturation and developmental potential of the oocytes. -

CONCLUSIONS

In IVF/ICSI patients, a positive correlation was found between AMH, inhibin B, and the activin A/inhibin B ratio in follicular fluid, on the one hand; and between serum 17-beta-estradiol levels and the numbers of oocytes retrieved, on the other. The activin A/inhibin B ratio correlated with the number of oocytes retrieved. The ratio for 17-beta-estradiol, oocyte numbers, and metaphase II oocytes relative to AMH indicated the best developmental potential, and it can therefore be assumed that there is a negative correlation between AMH levels and the maturation and quality of oocytes.

Risk and risk assessment for breast cancer: Molecular and clinical aspects

Chemoprevention, prophylactic surgery and intensified screening programs are options which can be offered the patients with an increased lifetime risk (p(life)) for breast cancer (BC). Estimation of p(life) includes BRCA mutation analysis and risk estimation based on individual risk factors and family history. MENDEL and BRCAPRO are models which can estimate mutation carrier status probability (p(mut)), p(life) and p(mut) can be estimated using Cyrillic3 software which incorporates BRCAPRO and MENDEL. To integrate age, hormonal factors and benign breast biopsies in risk assessment the Tyrer-Cuzick model can be used. These models support the decision pro or contra genetic analysis and improve the number of positive gene testing results. Estimations of p(life) and p(mut), based on a mathematical model, should deal with algorithms and penetrance/frequency data adequate to the population counselled. Being the main modulatory factors, reproductive/hormonal data should be incorporated like the Tyrer-Cuzick model does.