INTERACTION OF CISPLATIN WITH MEMBRANES OF RAT EHRLICH ASCITES TUMOR CELL

Quenching effects of cis-DDP on fluorescence of membranes of rat Ehrlich ascites tumor cell and binding of cis-DDP with the membranes were studied.The results indicate that cis-DDP can react with tumor cell membrane proteins.If the Pt binding sites were grouped into two types,the apparent stability canstants(K) and number of binding sites(n) are estimated.

ULTRASTRUCTURAL STUDY ON THE INVASION OF RETINAL INNER LIMITING MEMBRANE BY THE MALIGNANT TUMOR CELLS

To observe the process of invasion, retina of rat was used as a model to substitute the inner limiting membrane of retina for the basement membrane. Retina invaded by esophageal carcinoma cells and B16 melanoma cells upon the inner limiting membrane was studied by scanning and transmission electron microscopy. The results showed that the inner limiting membrane was destroyed by both kinds of tumor cells. The process of destruction was followed by a series of transformations in the inner limiting membrane, i.e. folding, swelling, thickening, and granular change. The inner limiting membrane was dissolved focally as a result of transformation, and then tumor cells invaded the retina through these dissolved regions. It seems that, as a barrier, the inner limiting membrane plays a similar role as the basement membrane.

Bacterial and cancerous cell membrane fused liposome coordinates with PD-L1 inhibitor for cancer immunotherapy

Although tumor cell membranes with broad-spectrum antigens have been explored for cancer vaccines for decades,their relatively poor capacity to stimulate immune responses,especially cellular immune responses,has limited their application.Here,we presented a novel bacterial and cancerous cell membrane fusogenic liposome for co-delivering cell membrane-derived antigens and adjuvants.Meanwhile,a programmed death-ligand 1(PD-L1)inhibitor,JQ-1,was incorporated into the formulation to tackle the up-regulated PD-L1 expression of antigen-presenting cells(APCs)upon vaccination,thereby augmenting its anti-tumor efficacy.The fusogenic liposomes demonstrated significantly improved cellular uptake by APCs and effectively suppressed PD-L1 expression in bone marrow-derived dendritic cells(BMDCs)in vitro.Following subcutaneous vaccination,the nano-vaccines efficiently drained to the tumor-draining lymph nodes(TDLNs),and significantly inhibited PD-L1 expression of both dendritic cells(DCs)and macrophages within the TDLNs and tumors.As a result,the liposomal vaccine induced robust innate and cellular immune responses and inhibited tumor growth in a colorectal carcinoma-burden mouse model.In summary,the fabricated cell membrane-based fusogenic liposomes offer a safe,effective,and easily applicable strategy for tumor immunotherapy and hold potential for personalized cancer immunotherapy.

4T1 cell membrane-derived biodegradable nanosystem for comprehensive interruption of cancer cell metabolism

Glycolysis inhibition can effectively block the energy supply and interrupt tumorigenesis in many types of cancers.However,when glycolysis is inhibited,tumor cells will break down glutamine as the raw material for the replenishment pathway to maintain the tricarboxylic acid cycle ensuring energy supply,therefore inducing ineffective interruption of metabolic.Herein,we designed glutamine transporter antagonist L-γ-glutamyl-p-nitroanilide(GPNA)loaded and 4T1 cancer cell membrane coated iridium oxide nanoparticles(IrO_(2)-GPNA@CCM)to realize a comprehensive inhibition of tumor energy supply which synergistically mediated by glycolysis and glutamine cycle.IrO_(2)NPs were used to catalyze the O_(2)generation by facilitating the decomposition of endogenous H_(2)O_(2)in tumor cells,which further downregulated the expression of HIF-1αand PI3K/pAKT to interrupt the generation of lactate.Meanwhile,the loaded GPNA was released under NIR irradiation to bind to alanine-serine-cysteine transporter(ASCT2)for glutamine uptake suppression,therefore realizing the comprehensive dysfunction of cell metabolism.Moreover,both in vitro and in vivo results convinced the thorough energy inhibition effect based on Ir O_(2)-GPNA@CCM NPs,which provided an inspiring strategy for future construction of tumor therapeutic regimen.

Gene-guided OX40L anchoring to tumor cells for synergetic tumor“self-killing”immunotherapy

The low objective response rates and severe side effects largely limit the clinical outcomes of immune checkpoint blockade(ICB)therapy.Here,a tumor“self-killing”therapy based on gene-guided OX40L anchoring to tumor cell membrane was reported to boost ICB therapy.We developed a highly efficient delivery system HA/PEI-KT(HKT)to co-deliver the OX40L plasmids and unmethylated CG-enriched oligodeoxynucleotide(CpG).On the one hand,CpG induced the expression of OX40 on T cells within tumors.On the other hand,OX40L plasmids achieved the OX40L anchoring on the tumor cell membrane to next promote T cells responses via OX40/OX40L axis.Such synergistic tumor“self-killing”strategy finally turned“cold”tumors to“hot”,to sensitize tumors to programmed cell death protein 1/programmed cell death ligand 1(PD-1/PD-L1)blockade therapy,and promoted an immune-mediated tumor regression in both B16F10 and 4T1 tumor models,with prevention of tumor recurrence and metastasis.To avoid the side effects,the gene-guided OX40L anchoring and PD-L1 silencing was proposed to replace the existing antibody therapy,which showed negligible toxicity in vivo.Our work provided a new possibility for tumor“self-killing”immunotherapy to treated various solid tumors.