The establishment of mouse models is critical for discovering the biological targets of tumorigenesis and cancer development, preclinical trials of targeted drugs, and formulation of personalized therapeutic regimens. Currently, the patient-derived xenograft (PDX) model is considered a reliable animal tumor model because of its ability to retain the characteristics of the primary tumor at the histopathological, molecular, and genetic levels, and to preserve the tumor microenvironment. The application of the PDX model has promoted in-depth research on tumors in recent years, focusing on drug development, tumor target discovery, and precise treatment of patients. However, there are still some common questions. This review introduces the latest research progress and common questions regarding tumors with high mortality rates, focusing on their application in targeted drug screening and the formulation of personalized medical strategies. The challenges faced, improvement methods, and future development of the PDX model in tumor treatment applications are also discussed. This article provides technical guidance and comprehensive expectations for anti-cancer drug screening and clinical personalized therapy.

AIM:Chronic exposure to elevated levels of free fatty acids (FFAs) in type 2 diabetes patients is toxic to pancreatic β-cells.Thioredoxin (Trx)-interacting protein (TXNIP), an endogenous Trx-inhibiting protein, is up-regulated by glucose and is a critical mediator of hyperglycemia-induced β-cell apoptosis in diabetes.However, the effects of FFAs on TXNIP are unknown.In this experiment we observed the effect of palmitate on TXNIP expression in cultured INS-1 islet cells and the pathways involved were analyzed meanwhile.METHODS:After the full basis of preliminary experiment of incubating INS-1 cells with palmitate at different concentrations for different time, INS-1 islet cells were cultured with 0.5 mmol/L palmitate for 24 h.TXNIP expression, cell apoptosis, and expression of transcription factors related to TXNIP transcriptional regulation were determined.RESULTS:Compared with control group, the expression of TXNIP at mRNA and protein levels in palmitate group was significantly up-regulated (P<0.01).Cleaved caspase-3/caspase-3 ratio was increased in palmitate group (P<0.05), and the apoptosis of the INS-1 cells was also significantly increased (P<0.01).Palmitate enhanced the phosphorylation of nuclear factor-κB (NF-κB) (P<0.01), and the NF-κB inhibitors, PDTC and SN50, both blocked the palmitate-induced up-regulation of TXNIP expression.CONCLUSION:Saturated fatty acid palmitate enhances the expression of TXNIP.The mechanism of palmitate-induced TXNIP expression may be associa-ted with the increase in NF-κB phosphorylation.

AIM: To clarify the role of nitric oxide(NO) in ischemic preconditioning(IP) and its effects on apoptosis. METHODS: Seventy-two male Wistar rats were divided into the following six groups:ischemia/reperfusion (IR) group,IP group,IR+L-arg group,IP+L-arg group,IR+L-NAME group and IP+L-NAME group,The following changes were measured:cardiac hemodynamic parameters,infarct size,PMNs counting myocardial MPO activity and TUNEL staining.RESULTS: ①L-arg significantly attenuated ischemia/reperfusion-induced heart injury,reduced PMNs infiltration and cardiomyocyte apoptosis.②L-NAME also significantly reduced infarct size,PMNs infiltration and cardiomyocyte apoptosis compared with IR group,however,L-NAME aggravated ischemia/reperfusions-induced cardiac functional injury.③L-arg or L-NAME did not significantly alter the protective effect of ischemic preconditioning. CONCLUSION: Increased production of endogenous NO before prolonged ischemic period can protect hearts and inhibit apoptosis.L-NAME can inhibit iNOS activity and ONOO- production in reperfusion period to protect heart.