NANO-SBT-PEDF delivery system: A promising approach against ovarian cancer?

Pigment epithelium-derived factor (PEDF) is a secreted glycoprotein involved in various biological processes. Its expression declines during ovarian carcinogenesis where it could decrease macrophages polarization, inhibit angiogenesis and induce apoptosis. Altogether, PEDF represents an ideal anti-cancer agent against ovarian cancer. We previously proposed the non-viral Sleeping Beauty transposon (SBT) system to stably integrate the PEDF transgene into ovarian cancer cells. Here, we report the development of liposomes and lipid nanoparticles for SBT-PEDF gene therapy. We determined that the SBT-PEDF nanolipid delivery system was the best system to increase the expression of PEDF in ovarian cancer spheroids. We also developed an ex vivo model of ovarian tumors which allowed us to show that nanolipoplexe in combination to paclitaxel exhibits synergistic and effective anti-tumor efficacy on ovarian tumors. These findings demonstrate that lipid nanoparticle for SBT-PEDF gene therapy may be a promising therapeutic approach for ovarian cancer.

Activated α2-macroglobulin binding to cell surface GRP78 induces trophoblastic cell fusion.

The villous cytotrophoblastic cells have the ability to fuse and differentiate, forming the syncytiotrophoblast (STB). The syncytialisation process is essential for placentation. Nevertheless, the mechanisms involved in cell fusion and differentiation are yet to be fully elucidated. It has been suggested that cell surface glucose-regulated protein 78 (GRP78) was involved in this process. In multiple cancer cells, cell membrane-located GRP78 has been reported to act as a receptor binding to the active form of α2-macroglobulin (α2M*), activating thus several cellular signalling pathways implicated in cell growth and survival. We hypothesised that GRP78 interaction with α2M* may also activate signalling pathways in trophoblastic cells, which, in turn, may promote cell fusion. Here, we observed that α2M mRNA is highly expressed in trophoblastic cells, whereas it is not expressed in the choriocarcinoma cell line BeWo. We thus took advantage of forskolin-induced syncytialisation of BeWo cells to study the effect of exogenous α2M* on syncytialisation. We first demonstrated that α2M* induced trophoblastic cell fusion. This effect is dependent on α2M*-GRP78 interaction, ERK1/2 and CREB phosphorylation, and unfolded protein response (UPR) activation. Overall, these data provide novel insights into the signalling molecules and mechanisms regulating trophoblastic cell fusion.

The fine-tuning of endoplasmic reticulum stress response and autophagy activation during trophoblast syncytialization.

The syncytiotrophoblast (STB) is a multinuclear layer forming the outer surface of the fetal part of the placenta deriving from villous cytotrophoblastic cell (vCTB) fusion and differentiation. This syncytialization process is characterized by morphological and biochemical alterations of the trophoblast, which probably require removal of pre-existing structures and proteins to maintain cell homeostasis and survival. Interestingly, autophagy, which allows degradation and recycling of cellular components, was shown to be activated in syncytiotrophoblast. Here we examined the involvement of endoplasmic reticulum stress (ERS) response in autophagy activation during vCTB syncytialization. We first demonstrated the activation of ERS response and autophagy during the time course of trophoblastic cell fusion and differentiation. Alteration of autophagy activation in vCTB by chemical treatments or Beclin-1 expression modulation leads to a decrease in trophoblastic syncytialization. Furthermore, ERS response inhibition by chemical treatment or siRNA strategy leads to a default in syncytialization, associated with alteration of autophagy markers and cell survival. From these data, we suggest that ERS response, by fine regulation of autophagy activation, may serve as an adaptive mechanism to promote cell survival during trophoblastic syncytialization.

A comparison of cotton and flocked swabs for vaginal self-sample collection.

OBJECTIVE: Vaginal self-sampling for human papillomavirus (HPV) testing has recently been proposed to optimize cervical cancer screening coverage. The objective of this study was to compare the performance of self-taken samples using flocked and cotton swabs for HPV detection and cellular retrieval. METHODS: We recruited women aged 21-65 years, referred to colposcopy at the Division of Gynecology of the Geneva University Hospitals between May and September 2016. Each participant collected 2 vaginal samples: 1 with a cotton swab and 1 with a flocked swab. A 1:1 randomization determined the order in which the 2 samples were taken. The swabs were introduced into a 20 mL PreservCyt® vial. Real-time polymerase chain reaction analysis using the Anyplex™ II HPV HR assay, cytofluorometric analysis and cytological cell counting were performed on each sample. RESULTS: A total of 119 participants were recruited in the study. Their mean ± standard deviation age was 35.1±8.9 years. The HPV prevalence was 29.7% and 38.1% according to the cotton and flocked swab, respectively (p=0.006). The mean number of cells collected per milliliter according to cytofluorometry was 96,726.6 with the cotton swab and 425,544.3 with the flocked swab (p<0.001). The mean number of cells detected at cytological cell count was 13,130.42 using the cotton swab and 17,503.6 using the flocked swab (p<0.001). CONCLUSION: The flocked swab achieved a greater cellular retrieval and showed an improved performance in HPV detection. Further studies are needed to assess the usability and cost-effectiveness of the 2 self-sampling devices.

Acellular fraction of ovarian cancer ascites induce apoptosis by activating JNK and inducing BRCA1, Fas and FasL expression in ovarian cancer cells.

Acellular fraction of ascites might play an active role in tumor development. Nevertheless the mechanisms involved in the tumor-modulating properties are still controversial. Here, we demonstrate that malignant ascites from 8 patients with epithelial ovarian cancer did not influence proliferative or invasive properties of ovarian cancer cells, but promoted H2O2-induced apoptosis and increased sensitivity to paclitaxel. Malignant ascites induced BRCA1, Fas and FasL expression and phosphorylation of JNK, but not the activation of caspase pathway. Ascites-induced apoptosis of ovarian cancer cells was strongly inhibited by a JNK inhibitor suggesting a critical role of JNK pathway in ascite-induced apoptosis. The use of siRNA JNK confirmed the importance of JNK in ascites-induced Fas and FasL expression. These results demonstrate that malignant ascites induce apoptosis of ovarian cancer cells and encourage us to think about the clinical management of ovarian cancer patients with malignant ascites.

Role of decidua in trophoblastic invasion.

OBJECTIVE: Proliferation, migration and invasion of trophoblastic cells into the maternal endometrium are essential steps in human embryo implantation and placentation. Trophoblast invasion is normally limited in time, only during first and early second trimester of pregnancy, and in space, limited to the endometrium and the proximal third of myometrium. This process requires among other factors: the metalloproteinases (MMP) 2 and 9. Shallow trophoblast invasion is associated with pathologies including preeclampsia and fetal growth restriction whereas unlimited invasion is associated with hydatidiform moles and choriocarcinomas. METHODS: In order to understand the role of decidua in this endometrial invasion by trophoblastic cells, we have developed a model of coculture of decidual and cytotrophoblastic cells in which we can evaluate the effect of each partner on the proliferative and invasive properties of the other. RESULTS: Surprisingly, decidual cells secrete highest levels of MMPs, and their invasive potential seems to be increased in presence of cytotrophoblast (CTB). In contrast, invasive properties of CTB are not modified by decidual cells. CONCLUSION: CTB secrete factors that favour invasion whereas decidua seems not to play a major role in regulating CTB invasion in vitro. Moreover, it is interesting to note that decidual cells could have potent invasive capacity which could explain, at least in part, endometriosis.

Effects of ligands or substrate of insulin-regulated aminopeptidase (IRAP) on trophoblast invasion.

Insulin-regulated aminopeptidase (IRAP) activity increases during placentation and in the invasive tumor cell of trophoblast suggesting a role for this peptidase in the invasiveness of normal and malignant trophoblast. To investigate this hypothesis, we studied the effects of substrate (OT) and inhibitors (angiotensin peptides and LVV-H7) of IRAP on the first trimester trophoblast proliferation and invasion. Addition of these peptides in the culture medium of trophoblastic cells significantly decreased metalloproteinase-9 activity and cellular invasiveness while no effect was observed on cell proliferation. The peptide IRAP inhibitors could exert their effect on cytotrophoblastic cell invasiveness by inhibition of its enzymatic activity, and thus increasing half life of the known placental peptide substrate of IRAP, OT.