Mechanism of chromosomal mosaicism in preimplantation embryos and its effect on embryo development.

Aneuploidy is one of the main causes of miscarriage and in vitro fertilization failure. Mitotic abnormalities in preimplantation embryos are the main cause of mosaicism, which may be influenced by several endogenous factors such as relaxation of cell cycle control mechanisms, defects in chromosome cohesion, centrosome aberrations and abnormal spindle assembly, and DNA replication stress. In addition, incomplete trisomy rescue is a rare cause of mosaicism. However, there may be a self-correcting mechanism in mosaic embryos, which allows some mosaicisms to potentially develop into normal embryos. At present, it is difficult to accurately diagnose mosaicism using preimplantation genetic testing for aneuploidy. Therefore, in clinical practice, embryos diagnosed as mosaic should be considered comprehensively based on the specific situation of the patient.

Cytotoxic effect of disulfiram/copper on human cervical cancer cell lines and LGR5-positive cancer stem-like cells.

BACKGROUND: Tumor resistance is a global challenge for tumor treatment. Cancer stem cells (CSCs) are the main population of tumor cells for drug resistance. We have reported that high aldehyde dehydrogenase (ALDH) activity represents a functional marker for cervical CSCs. Here, we aimed at disulfiram (DSF), an ALDH inhibitor, that has the potential to be used for cervical cancer treatment. METHODS: MTT assay, western blot, vector construction and transfection, cell sorting and in vivo anti-tumor assays were performed using cervical cancer cell lines SiHa and HeLa. Cell cycle distribution and cell apoptosis were carried out by flow cytometry. The cytotoxicity of DSF was detected by MTT assay and cervical cancer xenograft models. RESULTS: DSF was cytotoxic to cervical cancer cell lines in a copper (Cu)-dependent manner. Disulfiram/copper (DSF/Cu) complex induced deregulation of S-phase and inhibited the expression of stemness markers in cervical cancer cells. Furthermore, DSF/Cu could also reduce the cancer stem cell-like LGR5+ cells which lead to cisplatin resistance in cervical cancer cells. DSF/Cu complex had the greater antitumor efficacy on cervical cancer than cisplatin in vitro and in vivo. CONCLUSION: Our findings indicate that the cytotoxicity of DSF/Cu complex may be superior to cisplatin because of targeting LGR5-positive cervical cancer stem-like cells in cervical cancer. Thus, the DSF/Cu complex may represent a potential therapeutic strategy for cervical cancer patients.

Recurrent pregnancy loss: fewer chromosomal abnormalities in products of conception? a meta-analysis.

OBJECTIVE: To compare the prevalence of chromosomal abnormalities detected in products of conception (POCs) between recurrent pregnancy loss and sporadic pregnancy loss. METHODS: A systematic search was performed in the PubMed and Embase databases from inception to December 31, 2020. Relevant studies analysing the association between the number of pregnancy losses and the incidence of chromosomal abnormalities were included. Independent data extraction was conducted and study quality was assessed. Meta-analyses were carried out to calculate odds ratios by using fixed- or random-effects models according to statistical homogeneity. RESULTS: A total of 8320 POCs in 19 studies were identified for the meta-analyses. The incidence of chromosomal abnormalities in sporadic pregnancy loss was significantly higher than that in recurrent pregnancy loss. In subgroup analyses, the following studies reported a high incidence of abnormal outcomes of sporadic pregnancy loss: studies with ≥ 300 samples, studies published before 2014, studies conducted in European and American countries, and studies with analyses using conventional karyotype techniques. Moreover, the incidence of chromosomal abnormalities in women with two pregnancy losses was significantly higher than that in women with three or more pregnancy losses. However, there was no difference in the distribution of abnormal types between sporadic and recurrent pregnancy loss or between two and three or more pregnancy losses. CONCLUSIONS: The prevalence of chromosomal abnormalities detected in POCs was lower in recurrent pregnancy loss than in sporadic pregnancy loss, and decreased with an increasing number of pregnancy losses.

Absence of EpCAM in cervical cancer cells is involved in sluginduced epithelial-mesenchymal transition.

BACKGROUND: Slug (Snai2) is a pivotal player in initiating epithelial-mesenchymal transition (EMT) through its trans-suppression effect on E-cadherin in various normal and malignant cells. In this study, the positive effect of Slug on promoting cell motility and metastasis in cervical cancer was further confirmed in this study. METHODS: RNA-Seq was performed to explore the potential molecules that participate in Slug-mediated EMT in cervical cancer cells. The negative correlation between Slug and EpCAM expression in cervical cancer cells was detected in this study, and linked them with in vitro migration and invasion assay, in vivo metastasis experiments, luciferase reporter assay and Chromatin immunoprecipitation. RESULTS: Transcriptome sequencing analysis revealed that epithelial cell adhesion molecule (EpCAM) was significantly decreased in Slug-overexpressing SiHa cells. Simultaneously, an absence of EpCAM expression was observed in Slug-overexpressing cells. Further studies revealed the trans-suppression effect of Slug on EpCAM through its binding to the E-boxes in the proximal promoter region of EpCAM in cervical cancer cells. Restoring EpCAM in Slug-overexpressing cells by transiently transfecting an EpCAM recombinant plasmid attenuated cell motility and promoted cell growth. Moreover, the negative correlation between Slug and EpCAM expression in human squamous cervical carcinoma (SCC) samples was verified by using Pearson correlation analysis. CONCLUSIONS: These results demonstrated that the absence of EpCAM under Slug expression in cervical cancer cells probably participated in Slug-regulated EMT and further promoted tumor metastasis. Additionally, this study supports a potential way for Slug to initiate EMT progression in cervical cancer cells in addition to inhibiting E-cadherin.

Hexokinases 2 promoted cell motility and distant metastasis by elevating fibronectin through Akt1/p-Akt1 in cervical cancer cells.

BACKGROUND: Hexokinases 2 (HK2) is a member of the hexokinases, linking with malignant tumor growth and distant metastasis. However, evidence regarding the potential role of HK2 in regulating cell motility and tumor metastasis during the cervical cancer malignant progression remains limited. METHODS: In vitro migration and invasion assay, in vivo metastasis experiments were performed to detect the effective of HK2 on regulating cell motility and tumor metastasis in cervical cancer cells. RNA-Seq was performed to explore the potential molecules that participate in HK2-mediated cell motility and tumor metastasis in cervical cancer cells. The correlation between HK2 and Akt1, p-Akt1, FN1 expression in cervical cancer cells and human squamous cervical carcinoma (SCC) samples was verified in this study. RESULTS: In this study, cervical cancer cells with exogenous HK2 expression exhibited enhanced cell motility and distant metastasis. Transcriptome sequencing analysis revealed that fibronectin (FN1) was significantly increased in HK2-overexpressing HeLa cells, and the PI3K/Akt signaling pathway was identified by KEGG pathway enrichment analysis. Further studies demonstrated that this promotion of cell motility by HK2 was probably a result of it inducing FN1, MMP2 and MMP9 expression by activating Akt1 in cervical cancer cells. Additionally, HK2 expression was altered with the changing of Akt1/p-Akt1 expression, implying that HK2 expression is also modulated by Akt1/p-Akt1. Moreover, the positive correlation between HK2 and Akt1, p-Akt1, FN1 expression in human squamous cervical carcinoma (SCC) samples was verified by using Pearson correlation analysis. CONCLUSIONS: This study demonstrated that HK2 could activate Akt1 in cervical cancer cells, subsequently enhancing cell motility and tumor metastasis by inducing FN1, MMP2 and MMP9 expression. There likely exists an interactive regulatory mechanism between HK2 and Akt1 during the malignant process of cervical cancer.

6-Gingerol suppresses tumor cell metastasis by increasing YAPser127 phosphorylation in renal cell carcinoma.

According to the World Health Organization, the incidence and mortality rates of renal cell carcinoma (RCC) are rapidly increasing worldwide. Serious side effects caused by immune therapy and resistance to targeted drug therapy are urgent clinical problems facing kidney treatment. There is increasing global interest in developing natural products with a reduced number of side effects as adjunctive therapeutic options for RCC. Ginger is a spice and herbal remedy used worldwide, and 6-gingerol is a major pharmacologically active ingredient in ginger. In our study, we found that 6-gingerol suppressed RCC cell migration and metastasis in vitro and in vivo. Moreover, reduction in MMP2, Slug, and Vimentin protein levels was observed following 6-gingerol treatment of 786-O and ACHN cells. Furthermore, we revealed the mechanisms underlying the ability of 6-gingerol to inhibit RCC cell migration and metastasis. 6-Gingerol increased yes-associated protein (YAP)ser127 phosphorylation and reduced YAP levels in cell nuclei. We also used a series of loss-of-function and gain-of-function experiments to support our results. Western blot results showed that MMP2, Slug, and Vimentin protein expression was downregulated in YAP-silenced cells and upregulated in YAP-overexpressing cells. Transwell data demonstrated that YAP suppressed RCC migration ability. Immunofluorescence images showed that 6-gingerol decreased YAP levels, leading to disordered F-actin and a reduction in cell lamellipodia. Overall, our results indicated that 6-gingerol is a potential antimetastatic compound for use in kidney therapy.

NF-YA promotes the cell proliferation and tumorigenic properties by transcriptional activation of SOX2 in cervical cancer.

NF-YA is considered as a crucial regulator for the maintenance of cancer stem cell (CSC) and involved in various types of malignant tumours. However, the exact function and molecular mechanisms of NF-YA in the progression of cervical cancer remains poorly understood. Here, the expression of NF-YA detected by immunohistochemistry was gradually increased from normal cervical tissues, to the high-grade squamous intraepithelial lesions, and then to cervical cancer tissues. NF-YA promoted the cell proliferation and tumorigenic properties of cervical cancer cells as well as tumorsphere formation and chemoresistance in vitro. The luciferase reporter assay combined with mutagenesis analyses and Western blotting showed that NF-YA trans-activated the expression of SOX2 in cervical cancer. Furthermore, quantitative chromatin immunoprecipitation (qChIP) and electrophoretic mobility shift assay (EMSA) confirmed that NF-YA protein directly bound to the CCAAT box region located upstream of the SOX2 promoter. Together, our data demonstrated that NF-YA was highly expressed in cervical cancer and promoted the cell proliferation, tumorigenicity and CSC characteristic by trans-activating the expression of SOX2.

SALL4 promotes the tumorigenicity of cervical cancer cells through activation of the Wnt/ß-catenin pathway via CTNNB1.

SALL4 is overexpressed in many cancers and is found to be involved in tumorigenesis and tumor progression. However, the function of SALL4 in cervical cancer remains unknown. Here, we showed that the expression of SALL4 was gradually increased from normal cervical tissue to high-grade squamous intraepithelial lesions and then to squamous cervical carcinoma. SALL4 was upregulated or downregulated in cervical cancer cells by stably transfecting a SALL4-expressing plasmid or a shRNA plasmid targeting SALL4, respectively. In vitro, cell growth curves and MTT (3-(4,5-dimethylthiazole-2-yl)-2,5-diphenyltetrazolium bromide) assays showed that SALL4 promoted the cell proliferation of cervical cancer cells. In vivo, xenograft experiments verified that SALL4 enhanced the tumor formation of cervical cancer cells in female BALB/c Nude mice. Cell cycle analysis by fluorescence-activated cell sorting found that SALL4 accelerates cell cycle transition from the G0 /G1 phase to the S phase. TOP/FOP-Flash reporter assay revealed that SALL4 significantly upregulates the activity of Wnt/ß-catenin pathway. Western blotting showed that the expression levels of ß-catenin and important downstream genes, including c-Myc and cyclin D1, were increased by SALL4 in cervical cancer cells. Furthermore, dual-luciferase reporter and chromatin immunoprecipitation assays confirmed that SALL4 transcriptionally activated CTNNB1 by physically interacting with its promoters. Taken together, The results of this study demonstrated that SALL4 may promote cell proliferation and tumor formation of cervical cancer cells by upregulating the activity of the Wnt/ß-catenin signaling pathway by directly binding to the CTNNB1 promoter and trans-activating CTNNB1.

MicroRNA-543 acts as a prognostic marker and promotes the cell proliferation in cervical cancer by BRCA1-interacting protein 1.

Human cervical cancer is one of the most common malignancies worldwide. Recent studies have focused on microRNAs that play crucial roles in cancer development and progression of cervical cancer. In this study, we aimed to analyse the biological function of microRNA-543 in cervical cancer. Samples of human cervical cancer and matched adjacent normal cervical tissues were collected, and expression level of microRNA-543 and the clinical characteristics of cervical cancer were investigated. We found that microRNA-543 expression was significantly elevated in cervical cancer and its aberrant expression levels were positively correlated with tumour size ( p = 0.0315), differentiation ( p = 0.0134), clinical stage ( p = 0.0315) and overall ( p = 0.0426) and disease-free survival ( p = 0.0396) of cervical cancer. Overexpression of microRNA-543 in cancer-derived HeLa and SiHa facilitated cell growth and suppressed cell apoptosis, while down-regulation of microRNA-543 exerted a reverse effect on cell growth and apoptosis. In addition, we demonstrated that BRCA1-interacting protein 1 was directly regulated by microRNA-543 and the restoration of BRCA1-interacting protein 1 expression reversed the effects of microRNA-543 on cell proliferation. Taken together, these findings collectively demonstrate that microRNA-543 exerts its oncogene function by directly targeting BRCA1-interacting protein 1 in cervical cancer, indicating a potential novel potential prognostic biomarker and therapeutic target for cervical cancer.

Oxidative damage of the male reproductive system induced by paraquat.

The effects of paraquat (PQ) on the male reproductive system are unclear. In this study, male rats were divided into four groups (0, 0.5, 2, and 8 mg/kg) and treated with PQ by oral gavage for 8 weeks. At the end of the experiment, a significant decline in sperm count, motility, and viability and an increase in teratospermia were observed in the PQ-treated group (P < 0.05). Further investigation found that PQ resulted in enhanced lipid peroxidation and more apoptosis in the testis tissues, and apoptosis was likely to be associated with activation of the mitochondrial pathway. In summary, our study demonstrated oxidative damage due to PQ on the male reproductive system.

The microRNA-302-367 cluster suppresses the proliferation of cervical carcinoma cells through the novel target AKT1.

The miR-302-367 cluster is specifically expressed in human embryonic stem cells and has been shown to convert human somatic cells into induced pluripotent stem cells. Here, we investigated the role of the miR-302-367 cluster in cervical carcinoma. The cluster was not endogenously expressed in cervical cancer cells, and its ectopic expression did not reprogram the cervical cancer cells to an embryonic stem cell-like state. However, ectopic expression of the miR-302-367 cluster in HeLa and SiHa cervical cancer cells inhibited cell proliferation and tumor formation by blocking the G1/S cell cycle transition. We identified a new cell cycle regulatory pathway in which the miR-302-367 cluster directly down-regulated both cyclin D1 and AKT1 and indirectly up-regulated p27(Kip1) and p21(Cip1), leading to the suppression of cervical cancer cell proliferation. Our findings suggest that the miR-302-367 cluster may be used as a therapeutic reagent for the treatment of cervical carcinoma.

A comparison of the efficacy of two doses of letrozole alone or with continuous recombinant follicle-stimulating hormone for ovulation induction in anovulatory women.

AIMS: To determine the efficacy of letrozole alone or with recombinant follicle-stimulating hormone (rFSH) for ovarian induction in anovulatory women. METHODS: A total of 322 patients undergoing intrauterine insemination (IUI) were included in this retrospective study. Letrozole (2.5 or 5.0 mg) was administered from days 5 to 9 of menses, alone or followed with rFSH started on day 9 until the day of human chorionic gonadotropin administration. A single IUI was performed 24 h after ovulation. RESULTS: The number of follicles, endometrial thickness and serum estradiol levels were significantly higher in the letrozole + rFSH groups than in the letrozole-alone groups (p < 0.05), but no significant difference was found between the two doses of letrozole, whether alone or with rFSH. Women treated with 5.0 mg/day of letrozole + rFSH required a total dose of rFSH similar to women treated with 2.5 mg/day of letrozole + rFSH (230.77 ± 118.29 vs. 258.55 ± 130.13 IU, respectively; p = 0.205). There was no significant difference in pregnancy rates between the two doses of letrozole, whether alone or with rFSH. CONCLUSION: Treatment with letrozole + rFSH was more efficacious than letrozole alone for pregnancy in the IUI program; however, the effect of 5.0 mg/day of letrozole versus 2.5 mg/day of letrozole on ovulation was equivalent, regardless of whether rFSH was used.

Network self-organization explains the statistics and dynamics of synaptic connection strengths in cortex.

The information processing abilities of neural circuits arise from their synaptic connection patterns. Understanding the laws governing these connectivity patterns is essential for understanding brain function. The overall distribution of synaptic strengths of local excitatory connections in cortex and hippocampus is long-tailed, exhibiting a small number of synaptic connections of very large efficacy. At the same time, new synaptic connections are constantly being created and individual synaptic connection strengths show substantial fluctuations across time. It remains unclear through what mechanisms these properties of neural circuits arise and how they contribute to learning and memory. In this study we show that fundamental characteristics of excitatory synaptic connections in cortex and hippocampus can be explained as a consequence of self-organization in a recurrent network combining spike-timing-dependent plasticity (STDP), structural plasticity and different forms of homeostatic plasticity. In the network, associative synaptic plasticity in the form of STDP induces a rich-get-richer dynamics among synapses, while homeostatic mechanisms induce competition. Under distinctly different initial conditions, the ensuing self-organization produces long-tailed synaptic strength distributions matching experimental findings. We show that this self-organization can take place with a purely additive STDP mechanism and that multiplicative weight dynamics emerge as a consequence of network interactions. The observed patterns of fluctuation of synaptic strengths, including elimination and generation of synaptic connections and long-term persistence of strong connections, are consistent with the dynamics of dendritic spines found in rat hippocampus. Beyond this, the model predicts an approximately power-law scaling of the lifetimes of newly established synaptic connection strengths during development. Our results suggest that the combined action of multiple forms of neuronal plasticity plays an essential role in the formation and maintenance of cortical circuits.

Reproductive Effect by Rheumatoid Arthritis and Related Autoantibodies.

Rheumatoid arthritis (RA) is a common inflammatory arthritis in women. The effects of RA on the reproductive system are usually overlooked, as RA is not diagnosed until later in reproductive age. Whether RA itself or its related rheumatoid antibodies have an impact on female reproductive function has long been a thought-provoking issue. In brief, relevant epidemiological evidence has shown that women affected by RA are more likely to have coexisting reproductive disorders, including infertility, endometriosis, and premature ovarian insufficiency (POI), or to subsequently develop them. Furthermore, linkage between RA and pregnancy loss (PL) as well as polycystic ovary syndrome (PCOS) is also well known, albeit controversial in available evidence. RA and reproductive disorders appear to share a similar inflammatory immune response and genetic background. The stress experienced by patients with RA may affect their reproductive choices to some extent. Notably, few studies have explored the impact of rheumatoid antibodies such as rheumatoid factors (RFs) and anti-citrullinated protein antibodies (ACPAs) on reproductive disorders. Although it has been mentioned that the rate of RF and/or ACPA positivity is higher in women with a history of PL and POI, the clinical relevance of this relationship and underlying mechanisms still need to be further clarified.

Undifferentiated embryonic cell transcription factor-1 (UTF1) inhibits the growth of cervical cancer cells by transactivating p27Kip1.

Undifferentiated embryonic cell transcription factor-1 (UTF1) is an important transcription factor during development, which plays critical roles in cell fate determination. However, its expression and function in somatic tissues remain unclear. Here, we investigated the expression pattern of the UTF1 in the human normal and cancerous lesions of cervix and found that UTF1 was downregulated in cervical carcinogenesis, which was related to the hypermethylation of UTF1 promoter. Exogenous expression of UTF1 resulted in the significant inhibition of cell proliferation in vitro and tumorigenesis in vivo through attenuating cell cycle arrest via increasing the level of p27 (Kip1) . Luciferase reporter assay indicated that the region containing an intact activating transcription factor site between nucleotides -517 and -388 of the p27 (Kip1) promoter was indispensable for its activation by UTF1. Chromatin immunoprecipitation analysis confirmed the physical interaction between UTF1 and the p27 (Kip1) promoter. Taken together, our findings reveal that UTF1 attenuates cell proliferation and is inactivated in cervical carcinogenesis through epigenetic modification, which strongly supports that UTF1 is a potential tumor suppressor.

Cytoplasmic NANOG-positive stromal cells promote human cervical cancer progression.

Tumor development has long been known to resemble abnormal embryogenesis. The embryonic stem cell gene NANOG, a divergent homeodomain transcription factor that is independent of leukemia inhibitory factor, has been reported to be expressed in germ cells and in several tumor types. However, the short-term expression and role of NANOG in cervical cancer remain unclear. In the present study, we demonstrate that NANOG exhibits cellular shuttling behavior and increasing stromal distribution during the progression of cervical cancer. Our molecular data using RT-PCR and restriction enzyme digestion show that NANOG is mainly transcribed from the NANOG gene in cervical cancer. In addition, IHC using confocal microscopy suggests that mesenchymal stem cells (MSCs) are one type of cytoplasmic NANOG-positive cells in cervical cancer stroma. Co-culture of cervical cancer-derived MSCs with SiHa cells showed increased proliferation characteristics in vitro and enhanced tumor growth in vivo. Our results show, for the first time to our knowledge, that MSCs are a source of cytoplasmic NANOG expression in the cervical cancer stroma and that they participate in the progression of cervical cancer both in vitro and in vivo. Our study provides evidence that NANOG is a cervical cancer progression marker and also serves as a starting point for a more extensive exploration of the cellular translocation of NANOG and the multifunctionality of the stromal microenvironment.

ESRRB Inhibits the TGFß Signaling Pathway to Drive Cell Proliferation in Cervical Cancer.

Estrogen-related receptor ß (ESRRB) is a member of the orphan nuclear receptor family and mediates stem cell self-renewal and early embryonic development. Previous studies have also reported that ESRRB plays a role in the development and progression of breast cancer and prostate cancer. In this study, we observed that ESRRB was highly expressed in cervical cancer and was associated with disease progression. Knocking out ESRRB using CRISPR/Cas9 gene editing in cervical cancer cells induced cell-cycle arrest at the transition from the G0-G1 phase to the S phase, resulting in inhibition of cell proliferation in vitro and reduced tumor growth in vivo. Conversely, ectopic expression of ESRRB significantly promoted the proliferation of cervical cancer cells. ESRRB activated transcription of SMAD7, a TGFß pathway inhibitor, which blocked phosphorylation and nuclear translocation of SMAD2/3 to the nucleus, thereby downregulating CDKN1A and upregulating CCNA2 and MYC. In turn, MYC transactivated ESRRB and upregulated SMAD7, thus forming a positive feedback loop with ESRRB. Together, these findings identify the tumor-promoting function of ESRRB in cervical cancer and reveal a mechanism by which ESRRB stimulates cell proliferation to promote cancer progression. SIGNIFICANCE: The ESRRB/SMAD7/MYC-positive feedback loop inhibits TGFß signaling to activate cell-cycle progression and promote proliferation in cervical cancer, thereby driving tumor growth.

Strategies and challenges of mesenchymal stem cells-derived extracellular vesicles in infertility.

Having genetically related offspring remains an unattainable dream for couples with reproductive failure. Mesenchymal stem cells (MSCs) are multipotent stromal cells derived from various human tissues and organs. As critical paracrine effectors of MSCs, extracellular vesicles (EVs) can carry and deliver bioactive content, thereby participating in intercellular communication and determining cell fate. Mesenchymal stem cell-derived extracellular vesicles (MSC-EVs) have shown promising therapeutic effects, including repairing injured endometria, restoration ovarian functions, and improving sperm quantity, morphology, and motility, owing to their regenerative potential, abundant sources, high proliferation rates, low immunogenicity, and lack of ethical issues. However, limited knowledge on purification and isolation of MSC-EVs, therapeutic effects, and unpredictable safety have caused challenges in overcoming female and male infertility. To overcome them, future studies should focus on modification/engineering of MSC-EVs with therapeutic biomolecules and combining attractive biomaterials and MSC-EVs. This review highlights the latest studies on MSC-EVs therapies in infertility and the major challenges that must be overcome before clinical translation.

GDF15 deficiency hinders human trophoblast invasion to mediate pregnancy loss through downregulating Smad1/5 phosphorylation.

Growth differentiation factor 15 (GDF15) belongs to the Transforming growth factor ß(TGF-ß) superfamily. The decrease of GDF15 in the serum of pregnant women was associated with miscarriage. Both IHC and ELISA assays showed that GDF15 in trophoblast tissue and serum of pregnant women who miscarried was significantly lower than in those who had a live birth. GDF15 deficiency was associated with embryo resorption in GDF15 knockout mice through CRIPSR editing. In addition, the migration and invasion ability of HTR-8/SVneo and JEG-3 cells were promoted by GDF15. Mechanistically, GDF15 increased Smad1/5 phosphorylation, resulting in upregulating SNAI1/2, VIMENTIN and downregulating E-CADHERIN. A dual-luciferase reporter assay confirmed that Smad-binding elements (SBE) and/or GC-rich motifs were activated and target genes such as SNAI1/2, SERPINE1, and TIMP3 were transcriptionally regulated by GDF15/Smad5 signaling. Therefore, our data revealed a crucial role of GDF15 on invasion of trophoblast by upregulating the activity of TGF-ß/Smad1/5 pathway.

Krüppel-like factor 4 functions as a tumor suppressor in cervical carcinoma.

BACKGROUND: The Krüppel-like factor 4 (KLF4) protein, a zinc finger transcription factor that is highly expressed in epithelial tissues such as the gut and skin, has been implicated in both tumor suppression and progression. However, the role of KLF4 in human cervical carcinoma is still unclear. METHODS: The expression of KLF4 in cervical carcinoma tissues and cervical cancer cell lines was examined with immunohistochemistry and Western blot assay. The effects of KLF4 silencing and overexpression on the cell proliferation, cell viability, and tumor formation of cervical cancer cells were investigated. RESULT: KLF4 protein expression showed a pattern of gradual decrease from normal cervix to cervical carcinoma in situ and then to invasive cervical carcinomas (P < .05). Overexpression of KLF4 in SiHa and C33A cells resulted in significantly inhibited cell growth and significantly attenuated tumor formation. Consistently, KLF4 silencing in HeLa cells significantly promoted cell growth and tumor formation. Furthermore, KLF4 overexpression caused cell cycle arrest at the G1/S transition, along with the up-regulated expression of p27(Kip1) protein. Promoter analysis revealed that KLF4 transactivated the expression of p27(Kip1) through the specific motif that is between the nucleotides of -435 and -60 in its promoter. The results from chromatin immunoprecipitation assays demonstrated the physical interaction between KLF4 protein and this specific motif in p27(Kip1) promoter. CONCLUSIONS: KLF4 may function as a tumor suppressor in cervical carcinoma by inhibiting cell growth and tumor formation.