Research on Mechanism of miRNA-22 Related with Hepatocellular Carcinoma Metastasis for Regulating Process of Tumor Protein P53

The action of miRNA-22 related with HCC metastasis was analyzed in our study and the mechanism of miRNA-22 related with HCC metastasis was discussed. The HCC hep2 cell was transfected with miRNA-22 mimics and miRNA-22 NC instantaneously followed by analysis of cell migration by Transwell assay, cell viability by MTT and clone formation and cell apoptosis by flow cytometry. The action of miRNA-22 mimics and miRNA-22 on the expression of P53 mRNA in HCC Hep2 cell was detected by RT-PCR. The cell activity in miRNA-22 mimics group was significantly elevated compared with miRNA-22 NC group (P < 0.01). Meanwhile, the apoptotic rate, migrated and invaded capacity of HCC cell was significantly elevated (P < 0.01). The expression level of P53 mRNA was reduced (P < 0.01). In conclusion, overexpression of miRNA-22 could restrain the apoptosis of HCC hep2 cell and down-regulated the expression of P53 so as to prompt cell invasion capacity.

Cyclin G2 reverses immunosuppressive tumor microenvironment and potentiates PD-1 blockade in glioma

Background Expression of aberrant cyclin G2 is a key factor contributing to cancer biological processes, including glioma. However, the potential underlying mechanisms of cyclin G2 in the glioma tumor immune microenvironment remain unclear. Methods Co-immunoprecipitation (co-IP), in situ proximity ligation assay (PLA), and in vitro kinase assay were conducted to reveal the underlying mechanism by which cyclin G2 regulates Y10 phosphorylation of LDHA. Further, the biological roles of cyclin G2 in cell proliferation, migration, invasion capacity, apoptosis, glycolysis, and immunomodulation were assessed through in vitro and in vivo functional experiments. Expressions of cyclin G2 and Foxp3 in glioma specimens was determined by immunohistochemistry. Results In this study, we found that cyclin G2 impeded the interaction between LDHA and FGFR1, thereby decreasing Y10 phosphorylation of LDHA through FGFR1 catalysis. Cyclin G2 inhibited proliferation, migration, invasion capacity, and glycolysis and promoted apoptosis glioma cells via suppressing Y10 phosphorylation of LDHA. Moreover, we further verified that cyclin G2 reversed the immunosuppressive to antitumor immune microenvironment through inhibiting lactate production by glioma cells. Besides, cyclin G2 potentiated PD-1 blockade and exerted strong antitumor immunity in the glioma-bearing mice model. Conclusions Cyclin G2 acts as a potent tumor suppressor in glioma and enhances responses to immunotherapy. Our findings may be helpful in selecting glioma patients for immunotherapy trials in the future.

Phosphorylation of PUF-A/PUM3 on Y259 modulates PUF-A stability and cell proliferation

Human PUF-A/PUM3 is a RNA and DNA binding protein participating in the nucleolar processing of 7S to 5.8S rRNA. The nucleolar localization of PUF-A redistributes to the nucleoplasm upon the exposure to genotoxic agents in cells. However, little is known regarding the roles of PUF-A in tumor progression. Phosphoprotein database analysis revealed that Y259 phosphorylation of PUF-A is the most prevalent residue modified. Here, we reported the importance of PUF-A’s phosphorylation on Y259 in tumorigenesis. PUF-A gene was knocked out by the Crispr/Cas9 method in human cervix epithelial HeLa cells. Loss of PUF-A in HeLa cells resulted in reduced clonogenic and lower transwell invasion capacity. Introduction of PUF-AY259F to PUF-A deficient HeLa cells was unable to restore colony formation. In addition, the unphosphorylated mutant of PUF-A, PUF-AY259F, attenuated PUF-A protein stability. Our results suggest the important role of Y259 phosphorylation of PUF-A in cell proliferation.

The HIF1α/JMY pathway promotes glioblastoma stem-like cell invasiveness after irradiation

Human glioblastoma (GBM) is the most common primary malignant brain tumor. A minor subpopulation of cancer cells, known as glioma stem-like cells (GSCs), are thought to play a major role in tumor relapse due to their stem cell-like properties, their high resistance to conventional treatments and their high invasion capacity. We show that ionizing radiation specifically enhances the motility and invasiveness of human GSCs through the stabilization and nuclear accumulation of the hypoxia-inducible factor 1α (HIF1α), which in turn transcriptionally activates the Junction-mediating and regulatory protein (JMY). Finally, JMY accumulates in the cytoplasm where it stimulates GSC migration via its actin nucleation-promoting activity. Targeting JMY could thus open the way to the development of new therapeutic strategies to improve the efficacy of radiotherapy and prevent glioma recurrence.

Upregulation of Bag3 Exacerbates Cervical Cancer Progression by Impairing Immune Response and Inhibiting Cell Ferroptosis

Background: Cervical cancer remains a serious threat to women worldwide. Thus, effective strategies to treat cervical cancer are urgently needed. Bcl-2-associated athanogene 3 (Bag3) has been shown to be increased in several malignant neoplasms. However, little is known about the function of Bag3 in cervical cancer. We aimed to evaluate the function of Bag3 in cervical cancer progression.Method: qRT-PCR was carried out to test mRNA expression of Bag3, SLC7A11 and SLC3A2. Western blot analysis was conducted to detect protein expression of Bag3, SLC7A11 and SLC3A2. Cell proliferation was assessed using CCK-8, EdU and Colony formation assay. Flow cytometry assay was used to determine the frequency of IFN-γ- or TNF-α-producing CD8+ T cells. Transwell migration and invasion assay were carried out to detect cell migration and invasion capacity. Immunohistochemical staining was carried out to assess Bag3 and CD3 expressionResults: Bag3 was obviously elevated in cervical cancer tissues than in the adjacent normal tissues. Bag3 mRNA was upregulated in different cervical cancer cells (SiHa, C-33A, HT-3, and HeLa cells). SiHa cell proliferation, colony formation, and migration/invasion capacity were enhanced by Bag3 overexpression. Bag3 inhibited the immune response in cervical cancer. After C57BL6 mice were injected with Bag3-overexpressing SiHa cells, infiltrating CD3+ T cells around tumors were reduced. IFN-γ- and TNF-α-producing CD8+ T cells in tumor sections were remarkably inhibited by Bag3. Moreover, Ki-67+‑ and CD107a-producing CD8+ T cells were also suppressed. Bag3 repressed SiHa cell ferroptosis. Bag3 deletion inhibited cervical cancer development by improving the immune response and inducing ferroptosis. Conclusions: Taken together, these results indicated that Bag3 contributes to cervical cancer progression by impairing immune response and repressing cell ferroptosis.

A Structural Study on the Listeria Monocytogenes Internalin A—Human E-cadherin Interaction: A Molecular Tool to Investigate the Effects of Missense Mutations

Listeria monocytogenes is a widespread foodborne pathogen of high concern and internalin A is an important virulence factor that mediates cell invasion upon the interaction with the host protein E-cadherin. Nonsense mutations of internalin A are known to reduce virulence. Although missense mutations are largely overlooked, they need to be investigated in respect to their effects in cell invasion processes. This work presented a computational workflow to early characterize internalin A missense mutations. The method reliably estimated the effects of a set of engineered missense mutations in terms of their effects on internalin A–E-cadherin interaction. Then, the effects of mutations of an internalin A variant from a L. monocytogenes isolate were calculated. Mutations showed impairing effects on complex stability providing a mechanistic explanation of the low cells invasion capacity previously observed. Overall, our results provided a rational approach to explain the effects of internalin A missense mutations. Moreover, our findings highlighted that the strength of interaction may not directly relate to the cell invasion capacity reflecting the non-exclusive role of internalin A in determining the virulence of L. monocytogenes. The workflow could be extended to other virulence factors providing a promising platform to support a better molecular understanding of L. monocytogenes epidemiology.

Hampering brain tumor proliferation and migration using peptide nanofiber:siPLK1/MMP2 complexes

Aim: To develop a nonviral tool for the delivery of siRNA to brain tumor cells using peptide nanofibers (PNFs). Materials & methods: Uptake of PNFs was evaluated by confocal microscopy and flow cytometry. Gene silencing was determined by RT-qPCR and cell invasion assay. Results: PNFs enter phagocytic (BV-2) and nonphagocytic (U-87 MG) cells via endocytosis and passive translocation. si PLK1 delivered using PNFs reduced the expression of polo-like kinase 1 mRNA and induced cell death in a panel of immortalized and glioblastoma-derived stem cells. Moreover, targeting MMP2 using PNF:si MMP2 reduced the invasion capacity of U-87 MG cells. We show that stereotactic intra-tumoral administration of PNF:si PLK1 significantly extends the survival of tumor bearing mice comparing with the untreated tumor bearing animals. Conclusion: Our results suggest that this nanomedicine-based RNA interference approach deserves further investigation as a potential brain tumor therapeutic tool.