An enigmatic question exists concerning the pro- or anti-cancer status of mesenchymal stem cells (MSCs). Despite growing interest, this question remains unanswered, and the debate became intensified with new evidences backing each side. Here, we showed that human adipose MSC (hAMSC)-derived conditioned medium (CM) exhibited inhibitory effects on A2780 human ovarian cancer cells by blocking the cell cycle, and activating mitochondria-mediated apoptosis signalling. Explicitly, we demonstrated that exosomes, an important biological component of hAMSC-CM, could restrain proliferation, wound-repair and colony formation ability of A2780 and SKOV-3 cancer cells. Furthermore, hAMSC-CM-derived exosomes induced apoptosis signalling by upregulating different pro-apoptotic signalling molecules, such as BAX, CASP9, and CASP3, as well as downregulating the anti-apoptotic protein BCL2. More specifically, cancer cells exhibited reduced viability following fresh or protease-digested exosome treatment; however, treatment with RNase-digested exosomes could not inhibit the proliferation of cancer cells. Additionally, sequencing of exosomal RNAs revealed a rich population of microRNAs (miRNAs), which exhibit anti-cancer activities by targeting different molecules associated with cancer survival. Our findings indicated that exosomal miRNAs are important players involved in the inhibitory influence of hAMSC-CM towards ovarian cancer cells. Therefore, we believe that these comprehensive results will provide advances concerning ovarian cancer research and treatment.

MicroRNAs (miRNAs) are active regulators of numerous biological and physiological processes including most of the events of mammalian reproduction. Understanding the biological functions of miRNAs in the context of mammalian reproduction will allow a better and comparative understanding of fertility and sterility in male and female mammals. Herein, we summarize recent progress in miRNA‐mediated regulation of mammalian reproduction and highlight the significance of miRNAs in different aspects of mammalian reproduction including the biogenesis of germ cells, the functionality of reproductive organs, and the development of early embryos. Furthermore, we focus on the gene expression regulatory feedback loops involving hormones and miRNA expression to increase our understanding of germ cell commitment and the functioning of reproductive organs. Finally, we discuss the influence of miRNAs on male and female reproductive failure, and provide perspectives for future studies on this topic.

Nanocarriers are widely used for effective delivery of anticancer drugs to tumours with potential to improve cancer treatment. Here, we developed a nanoceria (CeO₂)-based system for delivery of the anti-cancer drug doxorubicin (DOX) to human ovarian cancer cells. Negatively charged nanoceria could conjugate with the cationic DOX via electrostatic interaction under physiological conditions, forming DOX-loaded nanoceria (CeO₂/DOX). CeO₂/DOX particles displayed nearly spherical shapes, along with superior drug-loading content (22.41%), loading efficiency (99.51%), and higher cellular uptake and drug release behaviours compared to free DOX. Moreover, DOX was released faster from CeO₂/DOX under reductive acidic conditions (pH 5.0, 10 mM glutathione) than under physiological conditions (pH 7.4). The initial intracellular DOX concentration was higher in the free DOX groups than in the CeO₂/DOX groups, but quickly reduced to 25% of the initial concentration after 24-h culture. By contrast, CeO₂/DOX showed sustained DOX release over time and maintained a high intracellular DOX concentration for up to 72 h. In vitro assays showed that CeO₂/DOX exhibited higher cell proliferation inhibition and apoptosis compared with free DOX. These results highlight DOX-loaded nanoceria as a promising therapeutic agent for cancer treatment.

Many diseases, including myocardial infarction, autoimmune disease, viral diseases, neurodegenerative diseases, and cancers, are frequently diagnosed with aberrant expression of microRNAs (miRNAs) and their allied pathways. This indicates the crucial role of miRNAs in maintaining biological and physiological processes. miR-7641 is a miRNA whose role in disease has not been fully investigated. In the present study, we investigated the expression pattern of miR-7641 and its target genes in different cancer cells, as well as in clinical cancer patients. Our data confirmed RPS16 and TNFSF10 as two direct targets of miR-7641, while gene expression study showed that a group of genes are also deregulated by miR-7641, including many ribosomal proteins that are frequently co-expressed with RPS16 in breast cancer. Direct inhibition of miR-7641 using a locked nucleic acid upregulated the expression of its target genes, sensitized cancer cells, and enhanced the efficiency of therapeutic agents such as doxorubicin. In addition, inhibition of miR-7641 boosted doxorubicin-mediated apoptosis of cancer cells via upregulation of apoptotic molecules Caspase 9 (CAS9) and poly ADP ribose polymerase (PARP) and downregulation of anti-apoptotic molecule BCL2. Thus, miR-7641 might be a clinically important cancer biomarker. Inhibition of miR-7641 expression could be an efficient treatment strategy for clinical patients.

Graphene oxide–silver nanoparticle (GO-AgNPs) nanocomposites have drawn much attention for their potential in biomedical uses. However, the potential toxicity of GO-AgNPs in animals and humans remains unknown, particularly in the developing fetus. Here, we reported the GO-AgNP-mediated cytotoxicity and epigenetic alteration status in caprine fetal fibroblast cells (CFFCs). In brief, the proliferation and apoptosis rate of GO-AgNP-treated CFFCs (4 and 8 µg/mL of GO-AgNPs) were measured using the cell-counting kit (CCK-8) assay and the annexin V/propidium iodide (PI) assay, respectively. In addition, the oxidative stress induced by GO-AgNPs and detailed mechanisms were studied by evaluating the generation of reactive oxygen species (ROS), superoxide dismutase (SOD), lactate dehydrogenase (LDH), malondialdehyde (MDA), and caspase-3 and abnormal methylation. The expression of pro- and anti-apoptotic genes and DNA methyltransferases was measured using reverse transcription followed by RT-qPCR. Our data indicated that GO-AgNPs cause cytotoxicity in a dose-dependent manner. GO-AgNPs induced significant cytotoxicity by the loss of cell viability, production of ROS, increasing leakage of LDH and level of MDA, increasing expression of pro-apoptotic genes, and decreasing expression of anti-apoptotic genes. GO-AgNPs incited DNA hypomethylation and the decreased expression of DNMT3A. Taken together, this study showed that GO-AgNPs increase the generation of ROS and cause apoptosis and DNA hypomethylation in CFFCs. Therefore, the potential applications of GO-AgNPs in biomedicine should be re-evaluated.

Ribosomal proteins (RPs) are mostly derived from the energy-consuming enzyme families such as ATP-dependent RNA helicases, AAA-ATPases, GTPases and kinases, and are important structural components of the ribosome, which is a supramolecular ribonucleoprotein complex, composed of Ribosomal RNA (rRNA) and RPs, coordinates the translation and synthesis of proteins with the help of transfer RNA (tRNA) and other factors. Not all RPs are indispensable; in other words, the ribosome could be functional and could continue the translation of proteins instead of lacking in some of the RPs. However, the lack of many RPs could result in severe defects in the biogenesis of ribosomes, which could directly influence the overall translation processes and global expression of the proteins leading to the emergence of different diseases including cancer. While microRNAs (miRNAs) are small non-coding RNAs and one of the potent regulators of the post-transcriptional gene expression, miRNAs regulate gene expression by targeting the 3′ untranslated region and/or coding region of the messenger RNAs (mRNAs), and by interacting with the 5′ untranslated region, and eventually finetune the expression of approximately one-third of all mammalian genes. Herein, we highlighted the significance of miRNAs mediated regulation of RPs coding mRNAs in the global protein translation.