Tmem39b promotes tumor progression and sorafenib resistance by inhibiting ferroptosis in hepatocellular carcinoma.

Hepatocellular carcinoma (HCC) poses a significant threat to human health. Resistance to sorafenib in the chemotherapy of HCC is a common and significant issue that profoundly impacts clinical treatment. While several members of the transmembrane (TMEM) protein family have been implicated in the occurrence and progression of HCC, the association between TMEM39b and HCC remains unexplored. This study revealed a significant overexpression of TMEM39b in HCC, which correlated with a poor prognosis. Subsequent investigation revealed that RAS-selective lethal 3 (RSL3) induced pronounced ferroptosis in HCC, and knocking down the expression of TMEM39b significantly decreased its severity. Similarly, following the induction of ferroptosis in HCC by sorafenib, knocking down the expression of TMEM39b also decreased the severity of ferroptosis, enhancing HCC tolerance to sorafenib. In conclusion, we propose that TMEM39b promotes tumor progression and resistance to sorafenib by inhibiting ferroptosis in HCC.

Tumor neoantigens: Novel strategies for application of cancer immunotherapy.

Neoantigen-targeted immunotherapy is a rapidly advancing field that holds great promise for treating cancer. The recognition of antigens by immune cells is a crucial step in tumor-specific killing, and neoantigens generated by mutations in cancer cells possess high immunogenicity and are selectively expressed in tumor cells, making them an attractive therapeutic target. Currently, neoantigens find utility in various domains, primarily in the realm of neoantigen vaccines such as DC vaccines, nucleic acid vaccines, and synthetic long peptide vaccines. Additionally, they hold promise in adoptive cell therapy, encompassing tumor-infiltrating cells, T cell receptors, and chimeric antigen receptors which are expressed by genetically modified T cells. In this review, we summarized recent progress in the clinical use of tumor vaccines and adoptive cell therapy targeting neoantigens, discussed the potential of neoantigen burden as an immune checkpoint in clinical settings. With the aid of state-of-the-art sequencing and bioinformatics technologies, together with significant advancements in artificial intelligence, we anticipated that neoantigens will be fully exploited for personalized tumor immunotherapy, from screening to clinical application.

CD-g-CS nanoparticles for enhanced antibiotic treatment of Staphylococcus xylosus infection.

Staphylococcus xylosus (S. xylosus)-induced cow mastitis is an extremely serious clinical problem. However, antibiotic therapy does not successfully treat S. xylosus infection because these bacteria possess a strong biofilm formation ability, which significantly reduces the efficacy of antibiotic treatments. In this study, we developed ceftiofur-loaded chitosan grafted with ß-cyclodextrins (CD-g-CS) nanoparticles (CT-NPs) using host-guest interaction. These positively charged nanoparticles improved bacterial internalization, thereby significantly improving the effectiveness of antibacterial treatments for planktonic S. xylosus. Moreover, CT-NPs effectively inhibited biofilm formation and eradicated mature biofilms. After mammary injection in a murine model of S. xylosus-induced mastitis, CT-NPs significantly reduced bacterial burden and alleviated inflammation, thereby achieving optimized therapeutic efficiency for S. xylosus infection. In conclusion, this treatment strategy could improve the efficiency of antibiotic therapeutics and shows great potential in the treatment of S. xylosus infections.

P16INK4a upregulation mediated by TBK1 induces retinal ganglion cell senescence in ischemic injury.

Glaucoma is a leading cause of irreversible blindness worldwide that is characterized by progressive retinal ganglion cell (RGC) death. However, RGC senescence as a phase before RGC death, and the mechanism of RGC senescence remains unclear. Here, we demonstrate that TANK-binding protein 1 (TBK1) is upregulated in acute IOP elevation-induced ischemic retinas mouse model. Moreover, pre-treatment with the TBK1 inhibitor BX-795 reduced p16INK4a (p16) expression and RGC senescence. Upregulation of TBK1 via plasmid transfection increased Akt phosphorylation at Ser473 and Bmi1 phosphorylation. The Akt inhibitor MK-2206 decreased the expression of p16 and Bmi1 serine phosphorylation. A Bmi1 Ser316 mutation also attenuated TBK1-induced p16 upregulation. Finally, silencing of TBK1 via shRNA knockdown reduced the expression of p16 as well as Akt and Bmi1 phosphorylation, reducing RGC senescence in vivo. These data suggest that acute IOP elevation-induced ischemia increases TBK1 expression, which then increases p16 expression through the Akt- Bmi1 phosphorylation pathway. This study therefore elucidates a novel mechanism whereby TBK1 regulates p16 expression and RGC senescence, suggesting a potential novel treatment strategy for minimizing RGC senescence in retinal ischemia and glaucoma.

Quercetin reduces cyclin D1 activity and induces G1 phase arrest in HepG2 cells.

Quercetin is able to inhibit proliferation of malignant tumor cells; however, the exact mechanism involved in this biological process remains unclear. The current study utilized a quantitative proteomic analysis to explore the antitumor mechanisms of quercetin. The leucine of HepG2 cells treated with quercetin was labeled as d3 by stable isotope labeling by amino acids in cell culture (SILAC). The isotope peaks of control HepG2 cells were compared with the d3-labeled HepG2 cells by mass spectrometry (MS) to identify significantly altered proteins. Reverse transcription-polymerase chain reaction (RT-PCR) and western blot analyses were subsequently employed to verify the results of the MS analysis. A flow cytometry assay was designed to observe the influence of various quercetin treatment concentrations on the cell cycle distribution of HepG2 cells. The results indicated that quercetin is able to substantially inhibit proliferation of HepG2 cells and induce an obvious morphological alteration of cells. According to the MS results, the 70 credibly-changed proteins that were identified may play important roles in multiple cellular processes, including protein synthesis, signaling, cytoskeletal processes and metabolism. Among these functional proteins, the expression of cyclin D1 (CCND1) was found to be significantly decreased. RT-PCR and western blot analyses verified the SILAC-MS results of decreased CCND1 expression. In summary, flow cytometry revealed that quercetin is able to induce G1 phase arrest in HepG2 cells. Based on the aforementioned observations, it is suggested that quercetin exerts antitumor activity in HepG2 cells through multiple pathways, including interfering with CCND1 gene expression to disrupt the cell cycle and proliferation of HepG2 cells. In the future, we aim to explore this effect in vivo.