Early urine proteome changes in the Walker-256 tail-vein injection rat model

Abstract

Detection of cancer at its early stage is important for treatment. Urine, which is not regulated by homeostatic mechanisms, reflects early systemic changes throughout the whole body and can be used for the early detection of cancer. In this study, the Walker-256 tail-vein injection rat model was established to find whether the urine proteome could reflect early changes if tumor grown in lung. Urine samples from the control group (n = 7) and Walker-256 tail-vein injection group (n = 7) on days 2, 4, 6 and 9 were analyzed by label-free proteomic quantitative methods. On day 2, when lung tumor nodules did not appear, 62 differential proteins were identified. They were associated with epithelial cell differentiation, regulation of immune system processes and the classical complement activation pathway. On day 4, when lung tumor nodules appeared, 72 differential proteins were identified. They were associated with the innate immune response and positive regulation of phagocytosis. On day 6, when body weight began to decrease, 117 differential proteins were identified. On day 9, the identified 125 differential proteins were associated with the B cell receptor signaling pathway and the positive regulation of B cell activation. Our results indicate that (1) the urine proteome changed even on the second day after tail-vein injection of Walker-256 cells and that (2) compared to previous studies, the urine proteomes were different when the same cancer cells were grown in different organs.

Urine proteome changes in a chronic unpredictable mild stress (CUMS) mouse model of major depressive disorder

“…We also compared the urinary differential proteins in the CUMS model to those in 15 other models, including a clinical model of autism [62] and a variety of animal models of Alzheimer's disease [11], Parkinson's disease [12], myocarditis [63] , chronic pancreatitis [64], unilateral ureteral obstruction model [65], astrocytoma [66], liver fibrosis [67] , pulmonary fibrosis [68] , glomerulosclerosis [69] , a model involving the injection of 10 tumor cells [70], the Walker-256 intracerebral tumor model [71], the Walker-256 liver tumor model [72], the Walker-256 subcutaneous model [73] and the Walker-256 lung metastasis model [74]. The comparison results are presented in Table S6.…”

Early urinary protein changes during tumor formation in a NuTu-19 tail vein injection rat model

“…The NuTu-19 tail vein injection group was injected with 2 × 10 6 viable NuTu-19 cells in 100 μL of PBS. The control group was injected with the same volume of PBS via the tail vein 14 .…”

“…Whole lung tissues were fixed in 4% formalin and embedded in paraffin. Then, paraffin sections (4 μm thick) were stained with HE to reveal the metastatic tumors 14 .…”

“…Then, each urinary protein was denatured with 20 mM DTT at 37 °C for 1 h and alkylated with 50 mM iodoacetamide (IAA) for 40 min in the dark. After being washed twice with UA and 25 mmol/L NH 4 HCO 3 , the denatured proteins were resuspended in 25 mmol/L NH 4 HCO 3 and digested with trypsin (enzyme:protein ratio of 1:50) at 37 °C for 14 h. The collected peptides were desalted using Oasis HLB cartridges (Waters, Milford, MA) and then dried by vacuum evaporation (Thermo Fisher Scientific, Waltham, MA) 14 .…”

“…In our previous studies, we used urinary proteomes to examine early alterations that occur before pathological changes or clinical manifestations in various tumor-bearing animal models, such as a subcutaneous Walker 256 (W256) rat model 11 , an intracerebral W256 rat model 12 , a glioma rat model 13 , and a W256 lung metastasis rat model 14 . However, there have been no studies on whether urine can be used to predict tumor formation.…”