Role and Mechanism of Epigenetic Regulation in the Aging of Germ Cells: Prospects for Targeted Interventions.

In modern times, a notable trend toward delayed childbearing has been observed in most developed countries. As a result, sperm aging and quality loss, as well as premature ovarian failure (POF), have emerged as major causes of infertility. The pathogenesis of sperm aging and POF is complex and has not been clearly elucidated. However, evidence from some studies has linked germ cell aging to epigenetic modifications. Epigenetics refers to the heritable changes in gene expression that occur in the absence of any alterations to the gene's nucleotide sequence. This paper systematically reviewed and analyzed the relevant literature to describe the relationship of DNA methylation, non-coding RNA regulation, histone modifications, chromatin remodeling, and RNA modifications with sperm aging and POF. In addition, we analyzed how sperm aging and POF can be mitigated via epigenetic interventions. This review could provide new therapeutic insights and guide strategies for improving sperm quality and ovarian function.

Pyroptosis and inflammasomes in cancer and inflammation.

Nonprogrammed cell death (NPCD) and programmed cell death (PCD) are two types of cell death. Cell death is significantly linked to tumor development, medication resistance, cancer recurrence, and metastatic dissemination. Therefore, a comprehensive understanding of cell death is essential for the treatment of cancer. Pyroptosis is a kind of PCD distinct from autophagy and apoptosis in terms of the structure and function of cells. The defining features of pyroptosis include the release of an inflammatory cascade reaction and the expulsion of lysosomes, inflammatory mediators, and other cellular substances from within the cell. Additionally, it displays variations in osmotic pressure both within and outside the cell. Pyroptosis, as evidenced by a growing body of research, is critical for controlling the development of inflammatory diseases and cancer. In this paper, we reviewed the current level of knowledge on the mechanism of pyroptosis and inflammasomes and their connection to cancer and inflammatory diseases. This article presents a theoretical framework for investigating the potential of therapeutic targets in cancer and inflammatory diseases, overcoming medication resistance, establishing nanomedicines associated with pyroptosis, and developing risk prediction models in refractory cancer. Given the link between pyroptosis and the emergence of cancer and inflammatory diseases, pyroptosis-targeted treatments may be a cutting-edge treatment strategy.

Biological roles of A-to-I editing: implications in innate immunity, cell death, and cancer immunotherapy.

Adenosine-to-inosine (A-to-I) editing, a key RNA modification widely found in eukaryotes, is catalyzed by adenosine deaminases acting on RNA (ADARs). Such RNA editing destabilizes endogenous dsRNAs, which are subsequently recognized by the sensors of innate immune and other proteins as autologous dsRNAs. This prevents the activation of innate immunity and type I interferon-mediated responses, thereby reducing the downstream cell death induced by the activation of the innate immune sensing system. ADARs-mediated editing can also occur in mRNAs and non-coding RNAs (ncRNAs) in different species. In mRNAs, A-to-I editing may lead to missense mutations and the selective splicing of coding regions. Meanwhile, in ncRNAs, A-to-I editing may affect targeting and disrupt ncRNAs maturation, leading to anomalous cell proliferation, invasion, and responses to immunotherapy. This review highlights the biological functions of A-to-I editing, its role in regulating innate immunity and cell death, and its potential molecular significance in tumorigenesis and cancer targeted therapy and immunotherapy.

SNORD60 promotes the tumorigenesis and progression of endometrial cancer through binding PIK3CA and regulating PI3K/AKT/mTOR signaling pathway.

Endometrial carcinoma is a common gynecological malignant tumor, small nucleolar RNAs (snoRNAs) are involved in cancer development. However, researches on the roles of snoRNAs in endometrial carcinoma are limited. The expression levels of snoRNAs in endometrial cancer tissues were analyzed using The Cancer Genome Atlas (TCGA) database. Antisense oligonucleotides (ASOs) and plasmids were used for transfection. Moreover, CCK-8, EdU, wound-healing assay, transwell, cell apoptosis, western blotting, and xenograft model were employed to examine the biological functions of related molecules. real-time reverse transcription polymerase chain reaction and western blotting were performed to detect messenger RNA (mRNA) and protein levels. Including bioinformatics, fluorescence in situ hybridization, RNA pulldown, actinomycin D and RTL-P assays were also carried out to explore the molecular mechanism. Analysis of data from TCGA showed that the expression level of small nucleolar RNA, C/D box 60 (SNORD60) in endometrial cancer tissues is observably higher than that in normal endometrial tissues. Further research suggested that SNORD60 played a carcinogenic role both in vitro and in vivo, and significantly upregulated the expression of PIK3CA. However, the carcinogenic effects can be reversed by knocking down fibrillarin (FBL) or PIK3CA. SNORD60 forms complexes by binding with 2'-O-methyltransferase fibrillarin, thus catalyzes the 2'-O-methylation (Nm) modification of PIK3CA mRNA and modulates the PI3K/AKT/mTOR signaling pathway, so as to promote the development of endometrial cancer. In short, SNORD60 might become a new biomarker for the therapy of endometrial cancer in the future and provide new strategies for diagnosis and treatment.

SNORA70E promotes the occurrence and development of ovarian cancer through pseudouridylation modification of RAP1B and alternative splicing of PARPBP.

The present study demonstrated for the first time that SNORA70E, which belongs to box H/ACA small nucleolar noncoding RNAs (snoRNAs) who could bind and induce pseudouridylation of RNAs, was significantly elevated in ovarian cancer tissues and was an unfavourable prognostic factor of ovarian cancer. The over-expression of SNORA70E showed increased cell proliferation, invasion and migration in vitro and induced tumour growth in vivo. Further research found that SNORA70E regulates RAS-Related Protein 1B (RAP1B) mRNA through pseudouracil modification by combing with the pyrimidine synthase Dyskerin Pseudouridine Synthase 1 (DKC1) and increase RAP1B protein level. What's more, the silencing of DKC1/RAP1B in SNORA70E overexpression cells both inhibited cell proliferation, migration and invasion through reducing ß-catenin, PI3K, AKT1, mTOR, and MMP9 protein levels. Besides, RNA-Seq results revealed that SNORA70E regulates the alternative splicing of PARP-1 binding protein (PARPBP), leading to the 4th exon-skipping in PARPBP-88, forming a new transcript PARPBP-15, which promoted cell invasion, migration and proliferation. Finally, ASO-mediated silencing of SNORA70E could inhibit ovarian cancer cell proliferation, invasion, migration ability in vitro and inhibit tumorigenicity in vivo. In conclusion, SNORA70E promotes the occurrence and development of ovarian cancer through pseudouridylation modification of RAP1B and alternative splicing of PARPBP. Our results demonstrated that SNORA70E may be a new diagnostic and therapeutic target for ovarian cancer.

Box C/D snoRNA SNORD89 influences the occurrence and development of endometrial cancer through 2'-O-methylation modification of Bim.

The small nucleolar RNA (snoRNA) is a type of small non-coding RNA widely distributed in the nucleoli of eukaryotic cells, promoting cancer development. The aim of this study was to assess box C/D snoRNA 89 (SNORD89) dysregulations in endometrial cancer. According to the TCGA database as well as the International Federation of Gynecology and Obstetrics (FIGO), higher SNORD89 expression is found in endometrial cancer tissues. In addition, the SNORD89 expression level was higher in endometrial carcinoma with lymph node metastasis than in endometrial carcinoma without lymph node metastasis. By interacting with the conservative chaperone protein methylase fibrillarin (Fbl), SNORD89 inhibits the translation process of the Bim gene, leading to a decrease in Bim protein. Cancer-promoting effect of SNORD89 can be reversed by Fbl knockdown or Bim overexpressing. What's more, ASO-mediated silencing of SNORD89 could inhibit endometrial cancer cell proliferation and migration ability. Taken together, SNORD89 can modify Bim through 2'-O-methylation and affect downstream signaling pathways to promote endometrial cancer occurrence and development. The role of methylation modification in the prevention and treatment of endometrial cancer provides a new understanding and SNORD89 may be a new diagnostic and therapeutic target for endometrial cancer.