CtIP interacts with a group of tumor suppressor proteins including RB (retinoblastoma protein), BRCA1, Ikaros, and CtBP, which regulate cell cycle progression through transcriptional repression as well as chromatin remodeling. However, how CtIP exerts its biological function in cell cycle progression remains elusive. To address this issue, we generated an inactivated Ctip allele in mice by inserting a neo gene into exon 5. The corresponding Ctip ؊/؊ embryos died at embryonic day 4.0 (E4.0), and the blastocysts failed to enter S phase but accumulated in G 1 , leading to a slightly elevated cell death. Mouse NIH 3T3 cells depleted of Ctip were arrested at G 1 with the concomitant increase in hypophosphorylated Rb and Cdk inhibitors, p21. However, depletion of Ctip failed to arrest Rb ؊/؊ mouse embryonic fibroblasts (MEF) or human osteosarcoma Saos-2 cells at G 1 , suggesting that this arrest is RB dependent. Importantly, the life span of Ctip ؉/؊ heterozygotes was shortened by the development of multiple types of tumors, predominantly, large lymphomas. The wild-type Ctip allele and protein remained detectable in these tumors, suggesting that haploid insufficiency of Ctip leads to tumorigenesis. Taken together, this finding uncovers a novel G 1 /S regulation in that CtIP counteracts Rbmediated G 1 restraint. Deregulation of this function leads to a defect in early embryogenesis and contributes, in part, to tumor formation.

miR‐375‐3p is a significantly downregulated miRNA in bladder cancer (BC). However, its role in BC regulation is still unclear. In this study, we reported that miR‐375‐3p overexpression inhibited proliferation and migration and promoted apoptosis in BC cells. Frizzled‐8 (FZD8) gene is identified as the direct miR‐375‐3p targeting gene. miR‐375‐3p blocks the Wnt/β‐catenin pathway and downstream molecules Cyclin D1 and c‐Myc by inhibiting the expression of FZD8 directly, it could increase caspase 1 and caspase 3 expression and promote T24 cell apoptosis as well. miR‐375‐3p also showed a significant inhibitory effect in vivo in bladder tumor‐bearing nude mice, as demonstrated by the reduced tumor volume and Ki67 proliferation index in tumor tissue. Collectively, miR‐375‐3p is a suppressor of BC that inhibits proliferation and metastasis, and promotes apoptosis in BC cells as well as suppresses tumor growth in a T24 xenograft mouse model, which could be used as a potential therapeutic approach for BC in future.

Natural killer cells, one of the important types of innate immune cells, play a pivotal role in the antiviral process in vivo. It has been shown that increasing NK cell activity may promote the alleviation of viral infections, even severe infection-induced sepsis. Given the current state of the novel coronavirus (SARS-CoV-2) global pandemic, clarifying the anti-viral function of NK cells would be helpful for revealing the mechanism of host immune responses and decipher the progression of COVID-19 and providing important clues for combating this pandemic. In this review, we summarize the roles of NK cells in viral infection and sepsis as well as the potential possibilities of NK cell-based immunotherapy for treating COVID-19.

Nowadays, tumor has been the serious threat to human health and life. To further explore the mechanism of tumor genesis and development is necessarily for developing the effective treatment strategy. Extracellular vesicles are the vesicles secreted by almost all types of cells, and they play an important part in intercellular communication by transporting their cargoes. Immune cells are the vital components of the human defense system, which defense against infection and tumor through cytotoxicity, immune surveillance, and clearance. However, via release tumor-derived extracellular vesicles, tumor could induce immune cells dysfunction to facilitate its proliferation and metastasis. Studies have shown that tumor-derived extracellular vesicles play dual role on immune cells by their specific cargoes. Here, we reviewed the effects of tumor-derived extracellular vesicles on immune cells in recent years and also summarized their research progress in the tumor immunotherapy and diagnosis.

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