Qi Chen

Placenta-derived trophoblast extracellular vesicles contain unique miRNAs that inhibit ovarian cancer cell growth

Abstract Previous reports have indicated that placental trophoblast extracellular vesicles (EVs) possess unique properties that enable them significantly to inhibit the proliferation of ovarian cancer cells in vitro and slow ovarian tumour growth in an in vivo model, while EVs derived from monocytes did not. However, the mechanisms underlying the inhibitory effects of trophoblast EVs remain unclear. In this study, we characterized the microRNAs (miRNAs) uniquely present in placental trophoblast EVs but absent from THP-1 monocyte-derived EVs. Through bioinformatic analysis, we elucidated the potential involvement of these unique miRNAs in the negative regulation of proliferation pathways implicated in ovarian cancer. Functional assays demonstrated that placental trophoblast EVs inhibited ovarian cancer cell proliferation, and this effect was reversed upon blocking EV uptake, indicating the transfer of the contents of the EVs as a crucial mechanism modulating cancer cell viability. Using miRNA mimics, we also demonstrated that specific miRNAs from placental trophoblast EVs exhibited inhibitory effects on ovarian cancer cell proliferation, highlighting the potential of placental trophoblast EVs as therapeutic agents. These findings not only shed light on the molecular mechanisms underlying the therapeutic efficacy of placental trophoblast EVs but also provide valuable insights into the potential development of miRNA-based therapies for ovarian cancer, including the use of trophoblast EVs as a therapeutic for ovarian cancer.

Placenta-derived trophoblast extracellular vesicles promote CD169+ macrophage migration and suppress ovarian tumour growth

A lower survival rate due to a later stage of diagnosis requires a more effective therapy for ovarian cancer. Extracellular vesicles (EVs) have shown therapeutic potential in various diseases, partly due to their ability to modulate immune responses. We previously showed that placental-derived trophoblast EVs suppressed ovarian tumour growth, accompanied by increased infiltration of CD169 SKOV-3 ovarian cancer cell xenografts were intraperitoneally injected with placental-derived trophoblast EVs. Tumour growth was monitored, and EV biodistribution was tracked at four time points. Additionally, the dynamics of CD169 A reduction of tumour growth after EV treatment was observed. At early time points (within 24 hours), trophoblast EVs preferentially accumulated in immune organs, including the inguinal lymph nodes, but not in tumours. The significantly higher intensity of CD169 Placental-derived trophoblast EVs may act as an immune modulator, specifically in the presence of tumours, through promoting CD169

Placental extracellular vesicles induce ovarian tumour cell death in an ex vivo explant model: Possible therapeutic potential

Placental extracellular vesicles (EVs), lipid-enclosed particles released from the placenta, can facilitate intercellular communication and are classified as micro- or nano-EVs depending on size. Placental EVs contain molecules associated with cell proliferation and death. In this study, we investigated whether treating human ovarian tumour explants with placental EVs could induce ovarian tumour cell death. Human ovarian tumours were collected. After directly treating human ovarian tumour explants with placental EVs, cellular necrosis was observed in ovarian tumour explants by HE stains. Cell death-associated miRNAs were measured. Expression of apoptosis and senescence-associated proteins, including NF-κβ and γ H2AX, were significantly increased, while proliferation-associated proteins were significantly reduced in the explants after exposure to placental EVs. Furthermore, miRNA-519a-5p, miRNA-512-3p and miRNA-143-3p, which were reported to promote ovarian cancer cell apoptosis or inhibition of ovarian cancer cell growth, were significantly increased, and the target genes of miRNA-519a-5p and miRNA-512-3p were significantly reduced in the explants after exposure to placental EVs. Transfection of SK-OV-3 ovarian cancer cells with a mimic of miRNA-519a-5p or miRNA-143-3p reduced the viability of these cells. Our study demonstrated that placental EVs could induce necrosis in ovarian tumour explants. Increased levels of apoptosis and senescence-associated proteins and miRNAs could contribute to this change in ovarian tumour cell phenotype after exposure to placental EVs.

Placental extracellular vesicles promoted cervical tumour tissue undergoing death

Cervical cancer is a leading cause of death in developing countries. Although the placenta is a tumor-like organ, the placental development, including invasive function, is well controlled. One mechanism is that extracellular vesicles (EVs) released from the placenta contribute to this regulation. Placental EVs carry functional proteins and regulatory RNAs. Our previous study reported that placental EVs inhibited ovarian cancer growth in vitro and in vivo. Whether the inhibitory effect induced by placental EVs also applies to cervical cancer, a non-endocrine-related cancer, in this study, we first co-cultured the cervical tumour tissues with placental explants. Co-culturing cervical tumour tissues (n = 7) with placental explants showed necrotic signs and increased levels of senescence-associated proteins and death-associated miRNAs, including miRNA-143-3p, miRNA-519a-5p and miRNA-199a-3p in tumour tissues. Additionally, treatment of HeLa cells with placental EVs reduced the viability of HeLa cells and inhibited the ability of invasion and migration of HeLa cells. Increased levels of senescence-associated proteins and reduced levels of proliferative proteins may contribute to the inhibitory effects in HeLa cells. placental EVs are involved in regulating placental development, and the delivery of cargo significantly impacts the functions of target cells. This study found that factors released from placental explants, likely placental EVs, had anti-tumour effects on the cervical tumour by inhibiting cervical cancer cell viability, invasion, and migration. Cargo in placental EVs, such as cellular death-associated miRNAs, may contribute to the inhibitory effects on cervical tumour.

Understanding How Pregnancy Protects Against Ovarian and Endometrial Cancer Development: Fetal Antigens May Be Involved

AbstractIt is well known that many factors, including infertility, obesity, type 2 diabetes, and family history of cancer, increase the risk of developing endometrial and ovarian cancer. However, multiparous women are known to have a lower risk of developing either ovarian or endometrial cancer than nonparous women. The lack of ovulation and shifting of sex hormonal balance, with decreased estrogen levels and increased progesterone levels during pregnancy, has traditionally been thought to be the major contributor to this decreased risk. However, in reality, the mechanisms underlying this phenomenon are relatively unknown. Increasing evidence suggests that endocrine factors are unlikely to completely explain the protective effect of pregnancies, and that multiple other nonendocrine mechanisms including fetal antigens and the newly proposed dormant cells hypothesis may also be involved. In this review, we summarize recent evidence and describe the potential underlying mechanisms that may explain how pregnancy protects against the development of ovarian and endometrial cancers in women's later life.

The histological type of endometrial cancer is not associated with menopause status at diagnosis

Abstract The latest evidence suggests that type 2 endometrial cancer may not be completely oestrogen-independent, indicating that the status of hormonal change may not be associated with the traditional classification of endometrial cancer, including the histological subtypes. However, this has not been investigated. Menopause is commonly considered a state of hormonal change in women. In the present study, we investigated the association of menopause with the histological types of endometrial cancer. Data on the histological type, menopause status at diagnosis, age at diagnosis, parity, body mass index (BMI), and overall survival rate from 2122 cases were collected. The difference in risk in developing type 1 or type 2 endometrial cancer between premenopausal and postmenopausal patients was 5.457%. A statistical difference in the association of menopause with the histological types between the two groups was seen in endometrioid and serous carcinoma, with a risk difference of 5.6 or 3.8%. A statistical difference in the association of menopause with parity between the groups was only seen in endometrioid and adenosquamous carcinoma, with a risk difference of 7.1 or 3.7%. However, BMI was not associated with histological type and the overall survival rate was not associated with menopause (P=0.764). We reported a relatively small difference in the association of menopause with type 1 or type 2, or the histological types of endometrial cancer. The survival rate was not associated with menopause. Our study suggests that menopause status at diagnosis was not strongly associated with the histological subtypes of endometrial cancer.

Norcantharidin inhibits the METTL16/MAT2A pathway to induce apoptosis and suppress tumor progression in ovarian cancer

This study aimed to investigate the antitumor effects of norcantharidin (NCTD) in ovarian cancer and to elucidate its molecular targets and mechanisms of action, with a focus on the methyltransferase-like protein 16 (METTL16)/methionine adenosyl transferase II alpha (MAT2A) signaling axis. Expression levels of METTL16 and MAT2A were analyzed in ovarian cancer tissues and cells using immunohistochemistry, quantitative real-time polymerase chain reaction, and western blotting. Human ovarian cancer cell lines (ES2 and SKOV3) were cultured and subjected to METTL16 overexpression via gene recombination. The cytotoxic effects of varying concentrations of NCTD were assessed using the Cell Counting Kit-8 assay. Apoptosis, proliferation, and migration were evaluated through flow cytometry and wound healing (scratch) assays. A subcutaneous xenograft model of human ovarian cancer was established in nude mice to assess in vivo antitumor efficacy. Enzyme-linked immunosorbent assay was used to quantify intracellular levels of S-adenosylmethionine (SAM). METTL16 and MAT2A gene expression levels were significantly elevated in ovarian cancer tissues and cell lines (p < 0.05). Treatment with NCTD at 10 μg/mL significantly inhibited proliferation and induced apoptosis in ES2 and SKOV3 cells. NCTD also suppressed cellular migration and angiogenic activity, with downregulation of related gene expression, effects that were attenuated by METTL16 overexpression (p < 0.05). In the xenograft model, NCTD administration significantly reduced tumor volume and downregulated expression of METTL16, MAT2A, protein phosphatase 2A (PP2A), and vascular endothelial growth factor (p < 0.05). NCTD exerts antineoplastic effects in ovarian cancer by reducing intracellular S-adenosylmethionine levels, promoting PP2A demethylation, and inhibiting the METTL16/MAT2A signaling pathway. These effects contribute to cell cycle arrest, suppressed proliferation, and enhanced apoptosis, supporting the therapeutic potential of NCTD in ovarian malignancies.

A pilot in vivo study: potential ovarian cancer therapeutic by placental extracellular vesicles

Abstract The biological links between cancer and pregnancy are of interest due to parallel proliferative, immunosuppressive, and invasive mechanisms between tumour and placental cells. However, the proliferation and invasion of placental cells are strictly regulated. The understanding of this regulation is largely unknown. Placental extracellular vesicles (EVs) may play an important role in this regulation, as placental EVs are known to contribute to maternal adaptation, including adaptation of the vascular and immune systems. We have previously reported that placental EVs significantly inhibited ovarian cancer cell proliferation by delaying the progression of the cell cycle. We, therefore, performed this pilot in vivo study to investigate whether placental EVs can also inhibit ovarian tumour growth in a SKOV-3 human tumour xenograft model. A single intraperitoneal injection of placental EVs at 15 days post tumour implantation, significantly inhibited the growth of the tumours in our in vivo model. Signs of cellular necrosis were observed in the ovarian tumour tissues, but not in other organs collected from mice that had been treated with placental EVs. Expression of receptor-interacting kinase 1 (RIPK1) and mixed linkage kinase domain-like (MLKL), which are mediators of necroptosis were not observed in our xenografted tumours. However, extensive infiltration of CD169+ macrophages and NK cells in ovarian tumour tissues collected from placental micro-EVs treated mice were observed. We demonstrate here that inhibition of ovarian tumour growth in our xenograft model by placental EVs involves cellular necrosis and infiltration of CD169+ macrophages and NK cells into the tumour tissues.

The Overexpression of Keratin 23 Promotes Migration of Ovarian Cancer via Epithelial‐Mesenchymal Transition

Background. Keratin 23 (KRT23) is a new member of the KRT gene family and known to be involved in the development and migration of various types of tumors. However, the role of KRT23 in ovarian cancer (OC) remains unclear. This study is aimed at investigating the function of KRT23 in OC. Methods. The expression of KRT23 in normal ovarian and OC tissues was determined using the Oncomine database and immunohistochemical staining. Reverse transcription quantitative polymerase chain reaction assay was used to analyze the expression of KRT23 in normal ovarian epithelial cell lines and OC cell lines. Small interfering RNA (siRNA), wound healing assay, and transwell assay were conducted to detect the effects of KRT23 on OC cell migration and invasion. Further mechanistic studies were verified by the Gene Expression Profiling Interactive Analysis platform, Western blotting, and immunofluorescence staining. Results. KRT23 was highly expressed in OC tissues and cell lines. High KRT23 expression could regulate OC cell migration and invasion, and the reduction of KRT23 by siRNA inhibited the migration and invasion of OC cells in vitro. Furthermore, KRT23 mediated epithelial‐mesenchymal transition (EMT) by regulating p‐Smad2/3 levels in the TGF‐β/Smad signaling pathway. Conclusions. These results demonstrate that KRT23 plays an important role in OC migration via EMT by regulating the TGF‐β/Smad signaling pathway.

The Hedgehog signaling pathway promotes chemotherapy resistance via multidrug resistance protein 1 in ovarian cancer

Various studies have revealed that the Hedgehog (Hh) signaling pathway promotes ovarian cancer invasion, migration and drug resistance. Previous studies by our group have identified a set of genes, including multidrug resistance gene 1 (MDR1), that are regulated by Hh signaling in ovarian cancer. However, the association between Hh signaling activation and MDR1 expression requires further validation. In the present study, reverse transcription‑quantitative PCR or western blot assays were used to evaluate the mRNA and protein expression levels of MDR1, Sonic Hh (Shh), glioma‑associated oncogene 2 (Gli2), Gli1 and γ‑phosphorylated H2A.X variant histone (γ‑H2AX). MTT and colony‑formation assays were performed to determine the effect of cisplatin (DDP) after inhibiting the Hh pathway in ovarian cancer cells. The results indicated that MDR1, Gli2 and Shh levels were much higher in SK‑OV‑3 cells with acquired DDP resistance than in native SK‑OV‑3 cells. ES‑2 cells with overexpression of Gli2 were capable of efficiently forming colonies in the presence of low DDP concentrations. By contrast, Gli2 knockdown in SK‑OV‑3 cells decreased the colony‑forming ability under the same concentration of DDP. As determined by MTT assays, knockdown of Gli2 or targeting of the Hh signaling pathway with either Gli‑antagonist 61 (GANT61) or cyclopamine, in combination with DDP treatment, diminished the viability of ES‑2 and SK‑OV‑3 cells, whereas Gli2 overexpression increased the viability of ES‑2 cells in the presence of DDP. Knockdown of Gli2 or targeting the Hh signaling pathway with GANT61 also increased γ‑H2AX levels but decreased the expression of MDR1 in the presence of DDP. MDR1 expression is regulated by the Hh signaling pathway and is likely a downstream transcription factor of Gli2. In conclusion, targeting the Hh signaling pathway increases the sensitivity of ovarian cancer to DDP. MDR1 is a target gene of the Hh signaling pathway and this pathway may affect chemoresistance of ovarian cancer to DDP via MDR1.

Extracts of the Medicinal Plants Pao Pereira and Rauwolfia vomitoria Inhibit Ovarian Cancer Stem Cells In Vitro

Ovarian cancer has an enrichment of cancer stem cells (CSCs) which contribute to the treatment resistant tumor’s high rate of recurrence and metastasis. Here we investigated 2 plant extracts from the medicinal plants Pao Pereira (Pao) and Rauwolfia vomitoria (Rau) each for their activities against ovarian CSCs. Both Pao and Rau inhibited overall proliferation of human ovarian cancer cell lines with IC50 ranging from 210 to 420 μg/mL and had limited cytotoxicity to normal epithelial cells. Ovarian CSC population was examined using cell surface markers and tumor spheroid formation assays. The results showed that both Pao and Rau treatment significantly reduced the ovarian CSC population. Pao and Rau had similar activities in inhibiting ovarian CSCs, with IC50s of ~120 μg/mL for 24 hours treatment, and ~50 μg/mL for long-term tumor spheroid formation. Nuclear β-catenin levels were decreased, suggesting suppression of Wnt/β-catenin signaling pathway. Taken together, data here showed that Pao and Rau both inhibited ovarian cancer stem cells, probably in preference to the bulk of tumor cells. Further mechanistic studies and in vivo investigation validating these findings are warranted, given that inhibition of cancer stem cells holds the promise of comprehensively inhibiting cancer metastasis, drug resistance and recurrence.