Acid-switchable nanoparticles induce self-adaptive aggregation for enhancing antitumor immunity of natural killer cells

Deficiency of natural killer (NK) cells shows a significant impact on tumor progression and failure of immunotherapy. It is highly desirable to boost NK cell immunity by upregulating active receptors and relieving the immunosuppressive tumor microenvironment. Unfortunately, mobilization of NK cells is hampered by poor accumulation and short retention of drugs in tumors, thus declining antitumor efficiency. Herein, we develop an acid-switchable nanoparticle with self-adaptive aggregation property for co-delivering galunisertib and interleukin 15 (IL-15). The nanoparticles induce morphology switch by a decomposition-metal coordination cascade reaction, which provides a new methodology to trigger aggregation. It shows self-adaptive size-enlargement upon acidity, thus improving drug retention in tumor to over 120 h. The diameter of agglomerates is increased and drug release is effectively promoted following reduced pH values. The nanoparticles activate both NK cell and CD8+ T cell immunity in vivo. It significantly suppresses CT26 tumor in immune-deficient BALB/c mice, and the efficiency is further improved in immunocompetent mice, indicating that the nanoparticles can not only boost innate NK cell immunity but also adaptive T cell immunity. The approach reported here provides an innovative strategy to improve drug retention in tumors, which will enhance cancer immunotherapy by boosting NK cells.

Correlation Between STK11 Gene Mutation and Immunotherapy of Non-small Cell Lung Cancer / 肿瘤防治研究

Lung cancer is one of the most common malignant tumors. Globally, the incidence and mortality of lung cancer are very high and on the rise. In recent years, immune checkpoint inhibitors (ICIs) have a significant survival advantage in treating advanced NSCLC. However, for NSCLC patients with positive driver genes, ICIs are not effective. But some tumor suppressor genes have varying degrees of impact on immunotherapy through mutations or deletions. Among them, serine/threonine kinase 11 (STK11) gene mutations are closely related to PD-1/PD-L1 ICIs. Studies have found that STK11 mutations are related to reduced immune cell infiltration, low PD-L1 expression and poor response to PD-L1 inhibition. This article reviews the research progress of the correlation between STK11 gene mutation and immunotherapy on NSCLC.

Light-controllable charge-reversal nanoparticles with polyinosinic-polycytidylic acid for enhancing immunotherapy of triple negative breast cancer

Nucleic acid drugs are highly applicable for cancer immunotherapy with promising therapeutic effects, while targeting delivery of these drugs to disease lesions remains challenging. Cationic polymeric nanoparticles have paved the way for efficient delivery of nucleic acid drugs, and achieved stimuli-responsive disassembly in tumor microenvironment (TME). However, TME is highly heterogeneous between individuals, and most nanocarriers lack active-control over the release of loaded nucleic acid drugs, which will definitely reduce the therapeutic efficacy. Herein, we have developed a light-controllable charge-reversal nanoparticle (LCCN) with controlled release of polyinosinic-polycytidylic acid [Poly(I:C)] to treat triple negative breast cancer (TNBC) by enhanced photodynamic immunotherapy. The nanoparticles keep suitably positive charge for stable loading of Poly(I:C), while rapidly reverse to negative charge after near-infrared light irradiation to release Poly(I:C). LCCN-Poly(I:C) nanoparticles trigger effective phototoxicity and immunogenic cell death on 4T1 tumor cells, elevate antitumor immune responses and inhibit the growth of primary and abscopal 4T1 tumors in mice. The approach provides a promising strategy for controlled release of various nucleic acid-based immune modulators, which may enhance the efficacy of photodynamic immunotherapy against TNBC.

Acquired Drug Resistance Mechanism of Osimertinib in the Targeted Therapy of Non-small Cell Lung Cancer / 中国肺癌杂志

While treating cancer, epidermal growth factor receptor-tyrosine kinase inhibitor (EGFR-TKI) still faces inevitable drug resistance. Investigations into the mechanisms which foster resistance to EGFR-TKI has led to the discovery of novel biomarkers and drug targets, and in turn has enabled the development of third-generation TKIs and proposals for rational therapeutic combinations. The threonine-to-methionine substitution mutation at position 790 (T790M) is clinically validated to engender refractoriness to first- and second-generation TKI, and is a standard-of-care predictive biomarker used in therapeutic stratification. For patients who are T790M-negative, cytotoxic chemotherapy or protracted EGFR-TKI treatment are acceptable treatment standards after disease progression, although combinations of targeted therapies and checkpoint blockade immunotherapy may offer promising alternatives in the future. Among T790M-positive patients, the third-generation EGFR-TKI, osimertinib, has shown superiority over both platinum-doublet chemotherapy and first-generation EGFR-TKI in randomized clinical trials. This article appraises the key literature on the contemporary management of non-small cell lung cancer patients with acquired resistance to EGFR-TKIs, and envisions future directions in translational and clinical research.

Protective effect of MSCs by distinct administration time on renal ischemia-reperfusion injury in rats / 中华器官移植杂志

Objective To observe the protection and distribution of bone marrow mesenchymal stem cells (MSCs) by distinct intravenous infusion time on renal ischemia reperfusion injury (IRI) in rats.Methods We used unilateral nephrectomy and contralateral vascular occlusion method to establish renal IRI model in rats.The experimental groups which received 2 × 106 MSCs infusion through the tail vein,were subsequently divided into 3 subgroups:2 h pre-reperfusion (PreOp,n =16),immediately after reperfusion (Op,n =16),6 h post-reperfusion (PostOp,n - 16).The control groups included sham operation group (n =16) and ischemia group (n =16).Chemotaxis of DAPI-labeled MSCs was detected 6 h after administration in the IR kidney.Renal function was detected at 6,24,and 48 h respectively after operation. Forty eight h after operation,the renal tissues were harvested to observe the pathological changes by HE staining and the tubular epithelial cell apoptosis via TUNEL assay.Results MSCs were found in the experimental groups after IR in the kidney,most in PostOp group.Twenty-four and 48 h after reperfusion,there was no significant difference in Cr and BUN between the experimental groups and sham operation group (P＞0.05),but the levels of Cr and BUN in the experimental groups were significantly lower than in the IR group (P＜ 0.05). As compared with IR group,the renal pathological injury was alleviated,the number of apoptotic cells was decreased in the experimental group,most significantly in PostOp group (P＜0.05).Conclusion MSCs can reduce the inflammatory response and inhibit renal tubular cell apoptosis in rat renal IRI.Post-reperfusion administration of MSCs leads to the best chemotaxis efficiency and protection.