SKOV3 Cells Research Articles

Synchronized delivery of dual-drugs for potentiating combination chemotherapy based on smart triple-responsive polymeric micelles

Here, we combined reversible addition-fragmentation chain transfer (RAFT) polymerization and amide coupling reaction to develop a novel drug-polymer conjugate using poly(AMA-co-IMMA)-b-poly(OEGMA) (termed as PAIPO) as nanocarriers. In order to enhance cellular uptake and obtain subsequent endo/lysosomal escape capacity, the dual-drugs-conjugated prodrug was then coupled with 2,3-dimethylmaleimide (DA) moieties and implanted with imidazolyl groups, respectively. Paclitaxel (PTX) was conjugated to PAIPO via 3,3′-dithiodipropionic acid (DPA) to construct a GSH-responsive moiety, while doxorubicin (DOX) was conjugated to PAIPO via 4-formyl benzoic acid to construct a pH-responsive moiety, which synergistically enabled a synchronized and precise drug delivery. The micelles self-assembled from DOX/PTX@PAIPODA showed an ideal average diameter (163.2–178.3 nm), contributing to passive targeting by the EPR effect. Moreover, a switch of the surface Zeta potential of micelles from steady negatively charged (− 9.74 ± 0.54 mV) at pH 7.4 to positively charged (+ 6.33 ± 1.25 mV) at pH 6.5, facilitated the long blood circulation and cellular endocytosis of micelles, respectively. More importantly, in vitro studies confirmed that DAM(DOXn/PTX) exhibited a strong synergism against tumor cells, and under slightly acidic conditions (pH 6.5), the combination index (CI) values for DAM(DOX1/PTX) on HeLa and Skov-3 cells were estimated to be 0.47 and 0.49 (previous to be 0.50 and 0.56 at pH 7.4), respectively. And in vivo results showed effective tumor accumulation potential, remarkable biosafety, and biocompatibility. Combined, such synchronized delivery approach based on multi-responsive micelles might potentiate the efficacy of combination chemotherapy in clinical cancer treatment.

Modified Linear Peptides Effectively Silence STAT-3 in Breast Cancer and Ovarian Cancer Cell Lines

RNA interference (RNAi) has drawn enormous attention as a powerful tool because of its capability to interfere with mRNA and protein production. However, designing a safe and efficient delivery system in RNAi therapeutics remains challenging. Herein, we have designed and synthesized several linear peptides containing tryptophan (W) and arginine (R) residues separated by the β-alanine (βA) spacer and attached to a lipophilic fatty acyl chain, cholesterol, or PEG. The peptide backbone sequences were: Ac-C-βA-βA-W4-βA-βA-R4-CO-NH2 and Ac-K-βA-βA-W4-βA-βA-R4-CO-NH2, with only a difference in N-terminal amino acid. The cysteine side chain in the first sequence was used for the conjugation with PEG2000 and PEG550. Alternatively, the side chain of lysine in the second sequence was used for conjugation with cholesterol or oleic acid. We hypothesized that amphiphilic peptides and optimum fatty acyl chain or PEG could function as an effective siRNA carrier by complementing each structural component's self-assembly and membrane internalization properties. None of the designed peptides showed cytotoxicity up to 10 µM. Serum stability studies suggested that the newly designed peptides efficiently protected siRNA against early degradation by nucleases. Flow cytometry analysis indicated 50-90% cellular uptake of siRNA using the newly developed modified linear peptides (MLPs). Western blot results revealed more than 90% protein downregulation after targeting STAT3 in MDA-MB-231 and SKOV-3 cell lines. In summary, a new peptide class was developed to safely and efficiently deliver siRNA.

Interleukin-6 and Hypoxia Synergistically Promote EMT-Mediated Invasion in Epithelial Ovarian Cancer via the IL-6/STAT3/HIF-1α Feedback Loop.

Extensive peritoneal spread and capacity for distant metastasis account for the majority of mortality from epithelial ovarian cancer (EOC). Accumulating evidence shows that interleukin-6 (IL-6) promotes tumor invasion and migration in EOC, although the molecular mechanisms remain to be fully elucidated. Meanwhile, the hypoxic microenvironment has been recognized to cause metastasis by triggering epithelial-mesenchymal transition (EMT) in several types of cancers. Here, we studied the synergy between IL-6 and hypoxia in inducing EMT in two EOC cell lines, A2780 cells and SKOV3 cells. Exogenous recombination of IL-6 and autocrine production of IL-6 regulated by plasmids both induced EMT phenotype in EOC cells characterized by downregulated E-cadherin as well as upregulated expression of vimentin and EMT-related transcription factors. The combined effects of IL-6 and hypoxia were more significant than those of either one treatment on EMT. Suppression of hypoxia-inducible factor-1α (HIF-1α) before IL-6 treatment inhibited the EMT phenotype and invasion ability of EOC cells, indicating that HIF-1α occupies a key position in the regulatory pathway of EMT associated with IL-6. EMT score was found positively correlated with mRNA levels of IL-6, signal transducer and activator of transcription 3 (STAT3), and HIF-1α, respectively, in 489 ovarian samples from The Cancer Genome Atlas dataset. Next, blockade of the abovementioned molecules by chemical inhibitors reversed the alteration in the protein levels of EMT markers induced by either exogenous or endogenous IL-6. These findings indicate a positive feedback loop between IL-6 and HIF-1α, and induce and maintain EMT phenotype through STAT3 signaling, which might provide a novel rationale for prognostic prediction and therapeutic targets in EOC.

Dual regulation of Akt and glutathione caused by isoalantolactone effectively triggers human ovarian cancer cell apoptosis.

Ovarian cancer is one of leading causes of cancer death in gynecological tumor. Isoalantolactone (IL), present in several medicinal plants, exhibits various biological activities, and its mechanism underlying anti-ovarian cancer activity needs to be further investigated. Here, we find that IL inhibits the proliferation of SKOV-3 and OVCAR-3 cells by causing G2/M phase arrest and inducing apoptosis. Moreover, IL decreases intracellular glutathione (GSH) level, and induces reactive oxygen species (ROS) generation in SKOV-3 cells. Furthermore, IL induces inactivation of Akt which is required for the cytotoxicity of IL. In addition, overexpression of Akt attenuates the IL-induced growth inhibition and ROS generation. GSH supplementation moderately increases the expression of phospho-Akt. Further investigation reveals that pretreatment with L-buthionine-sulfoximine (a GSH biosynthesis inhibitor) restores the Akt-mediated attenuation of growth inhibition induced by IL. Moreover, co-treatment with IL and wortmannin (an Akt pathway inhibitor) increases the growth inhibition attenuated by pretreatment with N-acetyl-L-cysteine (a precursor for GSH biosynthesis). These results indicate that inactivation of Akt and downregulation of GSH level induced by IL are related to each other. In conclusion, combined targeting Akt and GSH is an effective strategy for cancer therapy and IL can be a promising anticancer agent for further exploration.

P-Element-Induced Wimpy Testis Proteins and P-Element-Induced Wimpy Testis-Interacting RNAs Expression in Ovarian Cancer Stem Cells.

Background: P-element-induced wimpy testis (PIWI)-interacting RNAs (piRNAs) are a type of noncoding RNA and are predominantly expressed in germline cells. piRNAs function as gene regulators and potential biomarkers for the development of a number of malignancies. The biological importance of piRNAs in ovarian cancer is still unknown. In this study, we investigated the expression of piRNAs in ovarian cancer stem cells and compared it with that in adherent cells. Methods: To assess changes in the expression levels of PIWIL1/HIWI, PIWIL2/HILI, PIWIL3, and PIWIL4/HIWI2, we used quantitative reverse-transcription polymerase chain reaction (RT-qPCR) analysis. Changes in piRNA expression levels in ovarian cancer stem cells were analyzed using Arraystar piRNA microarray screening. Gene Ontology (GO) enrichment analysis was conducted to determine the potential functions of piRNAs. Results: Using microarray analysis, we identified a cohort of differentially expressed piRNAs. Fifteen piRNAs, including DQ570763 and DQ597396, were downregulated, and 58 piRNAs were upregulated when compared with those in adherent A2780 and SKOV3 cells (p > 0.05, >2.0, respectively). GO functions of the downregulated piRNAs (DQ570763 and DQ570797) suggest that their roles are commonly associated with the Golgi apparatus. In addition, A2780-SP and SKOV3-SP cells had higher PIWIL3 and PIWIL4 mRNA levels than adherent cells (A2780 and SKOV3). Moreover, we determined, using receiver operating characteristic plot, that the expression level of PIWIL4 was lower in responders than in nonresponders after treatment with platins in patients with ovarian cancer. Finally, in ovarian cancer, PIWIL4 expression was associated with somatic mutations of dynein axonemal heavy chain 2, signal induced proliferation associated 1 like 2, YTH N6-methyladenosine RNA-binding protein 1, TBC1 domain family member 8, and LPS responsive Beige-like anchor protein. Conclusion: Our study showed that PIWI proteins and piRNAs are potential diagnostic and prognostic biomarkers for ovarian cancer.

Self-Assembly Loading of Schisandra chinensis Nanoparticles and Its Effect on the Malignant Biological Behavior of Ovarian Cancer Cells

Schisandra polysaccharide (SCHP) was utilized as the target drug, and Zein (corn prolamine) was utilized as the drug carrier. First, SCHP/Zein nanoparticles (Zein-SCHP NPs) were prepared. Then, a polydopamine (PDP) coating was utilized to enhance the stability and tumor targeting of Zein. Finally, the folic acid (FA)-targeting ligand was covalently attached to the PDP-modified Zein-SCHP@PDP NP surface to form a highly pH-sensitive NP (Zein-SCHP@PDP-FA NPs) with active/passive targeting. In the experiment, apart from physical characterization of Zein-SCHP-based nanomaterials, the in vitro cytotoxicity and cell uptake properties of these materials were tested. In addition, an ovarian cancer cell line, SKOV3, was taken as the research object to explore the photodynamic-mediated killing effect of Zein-SCHP@PDP-FA NPs on this cancer cell. The results demonstrated that the average particle size of Zein-SCHP@PDP-FA NPs was (379.68±1.36) nm, the zeta potential was (−43.68±1.67) mV, the encapsulation efficiency was (97.86±1.38)%, and the drug loading was (11.75±0.16)%. Transmission electron microscope (TEM) suggested that the Zein-SCHP@PDP-FA NPs were spherical, and there was no adhesion between the particles. Differential scanning calorimetry (DSC) and far infrared (FIR) results indicated that SCHP existed in the NPs in the crystal structure and proved that the PDP and FA were successfully modified. The in vitro release of the drug showed that Zein-SCHP@PDP-FA NPs had sustained release, and the CCK-8 test showed that Zein-SCHP@PDP-FA NPs were highly cytotoxic and could notably reduce the IC50 values of SCHP. Furthermore, in vitro uptake experiments revealed that Zein-SCHP@PDP-FA NPs exhibited strong specific recognition in cells expressing different folate receptors. Compared with Zein-SCHP NPs and Zein-SCHP@PDP NPs, Zein-SCHP@PDP-FA NPs combined with photodynamic therapy enhanced reactive oxygen species (ROS) production in cells, downregulated hypoxia-inducible factor (HIF)-1α and interleukin (IL)-6 proteins, and exerted more destructive effects on SKOV3 cells.

Overexpression of MKRN2 Inhibits the Growth of Ovarian Cancer Cells

Ovarian cancer has a high mortality with low five-year survival rates. The role of the E3 ligase Makorin ring finger protein 2 (MKRN2) in ovarian cancer is unknown. This study investigated the impact of MKRN2 on the growth of ovarian cancer. MKRN2 expression in ovarian cancer tissue was analyzed by immunohistochemistry. Overexpression of MKRN2 was induced in two ovarian cancer cell lines (SKOV3 and CAOV3) by lentivirus transfection, and expression levels were verified by western blotting. Proliferation and growth were determined by CCK-8 and colony formation assays, while migration was examined using transwell assays and apoptosis by flow cytometry. Xenograft tumors of transfected SKOV3 cells were established in mice, and immunohistochemistry and TUNEL assays measured MKRN2 levels and apoptosis in tumor cells. Reduced levels of MKRN2 in cancerous tissue relative to non-cancerous ovarian tissues. Lentiviral-based MKRN2 overexpression in SKOV3 and CAOV3 cells reduced tumor-associated behavior while inducing apoptosis in vitro. In xenograft tumors, MKRN2 overexpression inhibited ovarian cancer growth and increased apoptosis in vivo. These findings imply the MKRN2 involvement in ovarian carcinogenesis and suggest its potential for treating the disease.

8P NXP800 versus cisplatin in ARID1a-mutated ovarian clear cell carcinoma xenograft models

NXP800 (CCT361814) is a Heat Shock Factor (HSF1) pathway inhibitor currently being studied in a phase 1 clinical trial (NCT05226507). NXP800 demonstrated substantial antitumor activity in cancer cell lines of different histologies, including ovarian clear cell and endometrioid carcinoma (OCCC and EOC), gastric carcinoma, and haematological cancers. Loss of function of ARID1A was identified as a predictive marker for response to NXP800 in OCCC and EOC. Here we describe an in vivo study of NXP800 versus cisplatin as an active control in cisplatin-resistant and cisplatin-sensitive ARID1A-mutated OCCC xenografts, supporting the clinical development of NXP800 in this indication. In vivo studies were performed by generating subcutaneous tumors in Nude (nu/nu) mice using TOV-21G and SKOV3 cell lines. Loss of ARID1A was confirmed in western blot. Treatment with NXP800 resulted in substantial tumor growth inhibition (TGI) in both models. In the TOV-21G model, baseline tumor volumes for the vehicle, cisplatin and NXP800 groups were 201.71, 205.66 and 202.20 mm3, respectively; on Day 28, average tumor volumes were 399.84, 236.68 and 121.47 mm3, respectively, representing increases in tumor volume of 98% for the vehicle control group and 15% for the cisplatin group, and a decrease in tumor volume of 41% for the NXP800 group. In the SKOV3 model, baseline tumor volumes for the vehicle, cisplatin and NXP800 groups were 136.2, 138.5 and 134.7 mm3, respectively; on Day 28, average tumor volumes were 312.94, 253.71 and 53.33 mm3, respectively, representing increases in tumor volume of 130% for the vehicle control group and 80% for the cisplatin group, and a decrease in tumor volume of 60% for the NXP800 group. NXP800 exhibits notable therapeutic activity in xenografts of OCCC – a condition of high unmet medical need with limited treatment options – including sustained tumour growth inhibition and regression both in cisplatin resistant (SKOV3) and sensitive (TOV-21G) OCCC models. Planned phase 1b expansion cohorts will include ovarian clear cell carcinoma and ovarian endometrioid carcinoma patients with ARID1A mutation.

Tuned activation of MSLN-CAR T cells induces superior antitumor responses in ovarian cancer models

BackgroundLimited persistence of functional CAR T cells in the immunosuppressive solid tumor microenvironment remains a major hurdle in the successful translation of CAR T cell therapy to treat solid tumors....

Niosomes nanoparticles as a novel approach in drug delivery enhances anticancer properties of chrysin in human ovarian carcinoma cells (SKOV3): an in vitro study.

Chrysin (Chr) has drawn a lot of attention recently due to its possible anticancer properties. However, Chr's short half-life and low bioavailability restricted its utility as a medicinal agent. The purpose of this research is to design, synthesize, and test the cytotoxic effects of nano-niosomes containing chrysin (Chr-Nio) on the SKOV3 ovarian cancer cell line. Chr-Nio has a nanoparticle polydispersity index (PDI) of 0.156 and a zeta potential of -27.4mV, with an average diameter of 105nm. Furthermore, Chr was encapsulated in Nio with an entrapment effectiveness of 85.5%. Chr-Nio cytotoxicity was shown to be more than free Chr in a time- and dose-dependent manner. Furthermore, as compared to free Chr-treated cells, the mRNA expression level of apoptotic genes Bcl-2, Bax, and caspase-3 in Chr-Nio-treated cells was considerably altered. According to the data, Chr may inhibit SKOV3 cell migration in vitro scratch wound experiments in a dose-dependent manner, and cells treated with Chr-Nio had the highest percentage of cell death. The findings of this study suggested that encapsulating Chr in niosome nanoparticles might be an effective medication delivery strategy for increasing Chr anticancer effects in the treatment of ovarian cancer.

A novel estrogen-targeted PEGylated liposome co-delivery oxaliplatin and paclitaxel for the treatment of ovarian cancer

Ovarian cancer is the second cause of death among gynecological malignancies. In this study, we designed a novel estrogen-targeted PEGylated liposome loaded with oxaliplatin and paclitaxel (ES-SSL-OXA/PTX) which could target estrogen receptor (ER) highly expressed on the surface of SKOV-3 cells to enhance therapeutic efficacy and reduce the side effects for SKOV-3 tumor therapy. ES-SSL-OXA/PTX was prepared by thin film hydration method and exhibited a uniform spherical morphology. Encapsulation efficiency (EE) were determined by HPLC method with the results of 44.10% for OXA and 65.85% for PTX. The mean particle size and polydispersity index (PDI) were 168.46 nm and 0.145, respectively. In vivo and in vitro targeting study confirmed that ES-SSL-OXA/PTX has optimum specific targeting ability. Meanwhile, In vitro and in vivo antitumor results of ES-SSL-OXA/PTX exhibited a superior antiproliferative effect on SKOV-3 cells and a stronger anti-tumor efficacy with the tumor inhibition rate of 85.24%. The pharmacokinetics results of ES-SSL-OXA/PTX showed a prolonged half-life time and a slowed clearance rate. The preliminary safety study of acute toxicity and long-term toxicity demonstrated ES-SSL-OXA/PTX exhibited a reduced toxicity profile. Based on the above results, ES-SSL-OXA/PTX could be a promising novel formulation for the treatment of ovarian cancer in future clinic.

LINC02489 with m6a modification increase paclitaxel sensitivity by inhibiting migration and invasion of ovarian cancer cells

ABSTRACT The long non-coding RNA LINC02489 has been shown to be significantly downregulated in advanced ovarian cancer (OC). However, the function of LINC02489 remains unknown. This study aims to explain the role and mechanism of LINC02489 in OC. The expression of LINC02489 was examined by qRT-PCR in primary OC tissues. Additionally, MTT, wound healing, transwell, and flow cytometry assays were used to analyze the function of LINC02489. The mechanism of LINC02489 in OC was investigated by high-throughput RNA-sequencing, qRT-PCR, western blot, and N6-methyladenosine (m6A) meRIP. A total of 1101 and 827 genes are significantly down-regulated and up-regulated in metastatic and chemoresistant OC tissues. The expression of LINC02489 is decreased in metastatic and chemoresistant OC tissues compared with the primary OC tissues (p < 0.05). Overexpression of LINC02489 inhibits proliferation, invasion, and migration of drug-resistant OC cells. In the LINC02489 overexpressed chemoresistant SKOV3 cells, the m6A modified LINC02489 is significantly up-regulated. Furthermore, the expression of PKNOX2 is increased during overexpression of LINC02489, while the expression of PTEN and mTOR plummets. This study demonstrates that LINC02489 can inhibit the invasion and migration of chemoresistant OC cells by increasing its m6A modification and up-regulating PKNOX2 expression. In addition, LINC02489 regulates the invasion ability of OC cells through the PTEN/mTOR signaling pathway, thereby regulating the sensitivity of SKOV3 cells to paclitaxel. This result provides a potential therapeutic target for chemoresistant OC.

Long non-coding RNA MYU promotes ovarian cancer cell proliferation by sponging miR-6827-5p and upregulating HMGA1.

Background: Long non-coding RNAs (lncRNAs) have been confirmed to play vital roles in tumorigenesis. LncRNA MYU has recently been reported as an oncogene in several kinds of tumors. However, MYU's expression status and potential involvement in ovarian cancer (OC) remain unclear. In this study, we explored the underlying role of MYU in OC. Methods and results: The expression of MYU was upregulated in OC tissues, and MYU's overexpression was significantly correlated with the FIGO stage and lymphatic metastasis. Knockdown of MYU inhibited cell proliferation in SKOV3 and A2780 cells. Mechanistically, MYU directly interacted with miR-6827-5p in OC cells; HMGA1 is a downstream target gene of miR-6827-5p. Furthermore, MYU knockdown increased the expression of miR-6827-5p and decreased the expression of HMGA1. Restoration of HMGA1 expression reversed the influence on cell proliferation caused by MYU knockdown. Conclusion: MYU functions as a ceRNA that positively regulates HMGA1 expression by sponging miR-6827-5p in OC cells, which may provide a potential target and biomarker for the diagnosis or prognosis of OC.

Histone methyltransferase SETD1A interacts with notch and promotes notch transactivation to augment ovarian cancer development

BackgroundHigh expression of SETD1A, a histone methyltransferase that specifically methylates H3K4, acted as a key oncogene in several human cancers. However, the function and underlying molecular mechanism of SETD1A in ovarian cancer (OV) remain markedly unknown.MethodsThe expression of SETD1A in OV were detected by Western blot and analyzed online, and the prognosis of STED1A in OV were analyzed online. The protein and mRNA levels were determined by Western blot and RT-qPCR. The cell proliferatin, migration and invasion were measured by CCK-8 and transwell assays. The protein interaction was detected by co-IP assay. The interaction between protein and DNA was performed by ChIP assay. The tumor growth in vivo was performed by xenograft tumor model.ResultsSETD1A was overexpressed in OV and a predictor of poor prognosis. Overexpression of SETD1A augmented the abilities of cell proliferation, migration, and invasion in MRG1 and OVCAR5 cells. In comparison, SETD1A knockdown suppressed cell growth, migration, and invasion in SKOV3 and Caov3 cells. Specifically, SETD1A enhanced Notch signaling by promoting the expression of Notch target genes, such as Hes1, Hey1, Hey2, and Heyl. Mechanistically, SETD1A interacted with Notch1 and methylated H3K4me3 at Notch1 targets to enhance Notch signaling. In addition, restoration of Notch1 in SETD1A-knockdown OV cells recovered cell proliferation, migration and invasion, which was inhibited by SETD1A knockdown. Furthermore, reduction of SETD1A suppressed tumorigenesis in vivo.ConclusionIn conclusion, our results highlighted the key role of SETD1A in OV development and proved that SETD1A promotes OV development by enhancing Notch1 signaling, indicating that SETD1A may be a novel target for OV treatment.

Retraction Note: Genistein inhibits stemness of SKOV3 cells induced by macrophages co-cultured with ovarian cancer stem-like cells through IL-8/STAT3 axis

This article has been retracted. Please see the Retraction Notice for more detail: https://doi.org/10.1186/s13046-018-1010-1.

NUF2 promotes tumorigenesis by interacting with HNRNPA2B1 via PI3K/AKT/mTOR pathway in ovarian cancer

BackgroundOvarian cancer (OC) is one of the commonest and deadliest diseases that threaten the health of women worldwide. It is essential to find out its pathogenic mechanisms and therapeutic targets for OC patients. Although NUF2 (Ndc80 kinetochore complex component) has been suggested to play an important role in the development of many cancers, but little is known about its function and the roles of proteins that regulate NUF2 in OC. This study aimed to investigate the effect of NUF2 on the tumorigenicity of OC and the activities of proteins that interact with NUF2.MethodsOncomine database and immunohistochemical (IHC) staining were used to evaluate the expression of NUF2 in OC tissues and normal tissues respectively. Normal ovarian epithelial cell lines (HOSEpiC) and OC cell lines (OVCAR3、HEY、SKOV3) were cultured. Western blot was applied to analyze the expression of NUF2 in these cell lines. Small interfering RNA (siRNA) was used to silence the expression of NUF2 in OC cell lines, SKOV3 and HEY. Gene Set Variation Analysis (GSVA), Gene Set Enrichment Analysis (GSEA), the CCK-8 method, colony formation assay and flow cytometry were conducted to analyze the biological functions of NUF2 in vitro. OC subcutaneous xenograft tumor models were used for in vivo tests. Immunoprecipitation and mass spectrometry (IP/MS) were performed to verify the molecular mechanisms of NUF2 in OC. IP, immunofluorescence, IHC staining, and Gene Expression Profiling Interactive Analysis platform (GEPIA) were used to analyze the relationship between HNRNPA2B1 and NUF2 in OC cells. SiRNA was used to silence the expression of HNRNPA2B1 in SKOV3 cells, reverse transcription quantitative polymerase chain reaction (RT-qPCR) assay and western blot were used to detect the effect of HNRNPA2B1 on NUF2. GEPIA, The Cancer Genome Atlas (TCGA) database, GSEA and western blot were used to detect the potential signaling pathways related to the roles of HNRNPA2B1 and NUF2 in OC cells.ResultsOur results showed high NUF2 expression in OC tissues and OC cell lines, which was associated with shorter overall survival and progression-free survival in patients. NUF2 depletion by siRNA suppressed the proliferation abilities and induced cell apoptosis of OC cells in vitro, and impeded OC growth in vivo. Mechanistically, NUF2 interacted with HNRNPA2B1 and activated the PI3K/AKT/mTOR signaling pathway in OC cells.ConclusionNUF2 could serve as a prognostic biomarker, and regulated the carcinogenesis and progression of OC. Moreover, NUF2 may interact with HNRNPA2B1 by activating the PI3K/AKT/mTOR signaling pathway to promote the development of OC cells. Our present study supported the key role of NUF2 in OC and suggested its potential as a novel therapeutic target.

Identification of key molecules in miRNA-mRNA regulatory network associated with high-grade serous ovarian cancer recurrence using bioinformatic analysis

To investigate the correlation of the potential functional microRNA (miRNA)-mRNA regulatory network with recurrence of high-grade serous ovarian carcinoma (HGSOC) and its biological significance. This study was performed based on the data of 354 patients with HGSOC from the Cancer Genome Atlas database. In these patients, HGSOC was divided into different subtypes based on the pathways identified by GO analysis, and the correlations of the subtypes with HGSOC recurrence and differentially expressed miRNAs and mRNAs were assessed. Two relapse-related datasets were identified using the Gene Set Enrichment (GSE) database, from which the differentially expressed miRNAs were identified by intersection with the TCGA data. The target genes of these miRNAs were predicted using miRWalk 2.0 database, and these common differentially expressed miRNAs and mRNAs were used to construct the key miRNA-mRNA network associated with HGSOC recurrence. The expression of miR-506-3p and SNAI2 in two ovarian cancer cell lines was detected using RT-qPCR and Western blotting, and their targeted binding was verified using a double luciferase assay. The effect of miR-506-3p expression modulation on ovarian cancer cell migration was detected using scratch assay and Transwell assay. We screened 303 GO terms of HGSOC-related pathways and identified two HGSOC subtypes (C1 and C2). The subtype C1 was associated with a significantly higher recurrence rate than C2. The differentially expressed genes between C1 and C2 subtypes were mainly enriched in epithelial-mesenchymal transition (EMT). Five miRNAs were identified as potential regulators of EMT, and a total of 41 target genes were found to be involved in the differential expressions of EMT pathway between C1 and C2 subtypes. The key miRNA-mRNA network associated with HGSOC recurrence was constructed based on these 5 miRNAs and 41 mRNAs. MiR-506-3p was confirmed to bind to SNAI2, and up-regulation of miR-506-3p significantly inhibited SNAI2 expression and reduced migration and invasion of SKOV3 and CAOV3 cells (P < 0.05), while miR-506-3p knockdown produced the opposite effects (P < 0.05). MiR-506-3p and SNAI2 are the key molecules associated with HGSOC recurrence. MiR-506-3p may affect EMT of ovarian cancer cells by regulating cell migration and invasion via SNAI2, and its expression level has predictive value for HGSOC recurrence.

Culture of leukocyte-derived cells from human peripheral blood: Increased expression of pluripotent genes OCT4, NANOG, SOX2, self-renewal gene TERT and plasticity.

There are few stem cells in human peripheral blood (PB). Increasing the population and plasticity of stem cells in PB and applying it to regenerative medicine require suitable culture methods. In this study, leukocyte populations 250 mL of PB were collected using a blood separator before that were cultured in optimal cell culture medium for 4 to 7 days. After culturing, stemness characteristics were analyzed, and red blood cells were removed from the cultured cells. In our results, stemness markers of the leukocyte populations Sca-1+ CD45+, CD117+ CD45+, and very small embryonic-like stem cells CD34+ Lin- CD45- and CXCR4+ Lin- CD45- were significantly increased. Furthermore, the expression of stem cell genes OCT4 (POU5F1), NANOG, SOX2, and the self-renewal gene TERT was analyzed by quantitative real-time polymerase chain reaction in these cells, and it showed a significant increase. These cells could be candidates for multi-potential cells and were further induced using trans-differentiation culture methods. These cells showed multiple differentiation potentials for osteocytes, nerve cells, cardiomyocytes, and hepatocytes. These results indicate that appropriate culture methods can be applied to increase expression of pluripotent genes and plasticity. Leukocytes of human PB can be induced to trans-differentiate into pluripotent potential cells, which will be an important breakthrough in regenerative medicine.

NK cell-derived exosomes enhance the anti-tumor effects against ovarian cancer by delivering cisplatin and reactivating NK cell functions.

Exosomes are membranous vesicles actively secreted by almost all cells and they deliver certain intracellular molecules, including nucleic acids, proteins, and lipids, to target cells. They are also considered to be good carriers for drug delivery due to their biocompatibility, high permeability, low immunogenicity, and low toxicity. Exosomes from immune cells were also reported to have immunomodulatory activities. Herein we evaluated the application of exosomes derived from expanded natural killer cells (eNK-EXO) for the treatment of ovarian cancer (OC). We demonstrate that eNK-EXO express typical protein markers of natural killer (NK) cells, can be preferentially uptaken by SKOV3 cells, and display cytotoxicity against OC cells. Furthermore, eNK-EXO loaded with cisplatin could sensitize drug-resistant OC cells to the anti-proliferation effect of cisplatin. In addition, we show that eNK-EXO could activate NK cells from immunosuppressive tumor microenvironment, the mechanism of which is explored by transcriptional analysis. In summary, eNK-EXO exhibit anti-tumor activity against OC on its own, could be used to deliver cisplatin and enhance its cytotoxic effect against drug-resistant OC cells and also reverse the immunosuppression of NK cells, which may lead to great prospect of using eNK-EXO in the treatment of OC in the clinic. Our work also builds a strong foundation for further evaluation of eNK-EXO in other solid tumor therapies.

High-Dose Selenium Induces Ferroptotic Cell Death in Ovarian Cancer.

Selenium is a promising multi-target chemotherapeutic agent with controversial clinical results. Hence, reassessing the anticancer effects of Se is necessary to clearly understand the potential of high-dose selenium in cancer treatment. Here, we observed that high-dose sodium selenite (SS) significantly decreased the proliferation and increased the death of ovarian cancer cells, mediated by an increased generation of reactive oxygen species. Notably, high-dose SS decreased the levels of glutathione peroxidase (GPx), a selenoprotein with antioxidant properties, without altering other selenoproteins. Furthermore, high-dose SS triggered lipid peroxidation and ferroptosis, a type of iron-dependent cell death, due to dysregulated GPx4 pathways. We demonstrated that intravenous high-dose SS significantly reduced the tumor growth and weight in SKOV3-bearing mice. Consistent with our in vitro results, mice with SKOV3 cells treated with high-dose SS showed decreased GPx4 expression in tumors. Therefore, we highlight the significance of high-dose SS as a potential chemotherapeutic agent for ovarian cancer. High-dose SS-mediated ferroptotic therapy integrating glutathione depletion and ROS generation is a promising strategy for cancer therapy.