Fig 1: Paracrine PAI-1 induces chemoresistance of ESCC cells in vivo.a, b NIH3T3 engineered to express PAI-1 promoted the growth of ESCC in vivo. NIH3T3 cells with stable expression of vector control (NIH3T3C) and PAI-1 (NIH3T3PAI-1) were generated. Tumors derived from KYSE-30 cells alone, KYSE-30 cells in combination with NIH3T3C control or KYSE-30 cells in combination with NIH3T3PAI-1 are shown. c, d In vivo responses of KYSE-30 tumors to cisplatin chemotherapy. Xenografts were derived from KYSE-30 cells alone or KYSE-30 cells combined with either NIH3T3 cells expressing a control vector (KYSE-30 + NIH3T3C) or NIH3T3 cells expressing PAI-1 (KYSE-30 + NIH3T3PAI-1). Cisplatin was administered every 3 days for 3 weeks. The xenografts were harvested and tumor volumes were determined. Each data point represents an individual xenograft. Horizontal lines are group means of five tumors. e, f KYSE-30 cells and CAFCIS were subcutaneously injected into the right flanks of nude mice. The animals were treated with cisplatin and cisplatin + tiplaxtinin. *p < 0.05, **p < 0.01, ***p < 0.001 vs the control group
Fig 2: Proteomic analysis of ESCs secretome. CM-ctr and CM-sen – conditioned media from young or senescent ESCs, respectively. (A) Venn diagram presentation of all peptides identified within CMs by LC-MS/MS. (B) Volcano plot of proteins differentially secreted by Ctr and Sen ESCs. (C) and (D) Functional enrichment analysis in GO BP terms of up- and down-regulated proteins in CM-sen versus CM-ctr. Identified processes are organized in modules based on common parent GO terms presented in legends. To control the false discovery rate (FDR) to correct the p-value the Benjamini method was applied. Black line indicates threshold at p=0.05. (E) and (F) Levels of top up- and down-regulated proteins in CM-sen versus CM-ctr, respectively. Processes involving PAI-1 are marked with asterisk (*).
Fig 3: PAI-1 expressed in CAFs is positively correlated with poor survival in ESCC patients.a Immunohistochemical staining of PAI-1 expression in CAFs and in tumor tissues in 49 ESCC patients. Scale bar, 50 µm. b The Kaplan–Meier curves for PFS of patients who received cisplatin after operation with high and low PAI-1 expression in CAFs
Fig 4: PAI-1 is the key cytokine secreted by CAFs after cisplatin treatment.a By using a RayBiotech human cytokine array, we found that the cytokine PAI-1 was upregulated after cisplatin pretreatment of CAFs. b By ELISA, the concentration of PAI-1 was confirmed to be higher in the CM CAFCIS compared with the CM CAFCTR. c Western blot results showed increased expression of ?-H2AX, phosphorylated p53, p21, and PAI-1 in CAFs that received cisplatin treatment compared with cells in the control group. The results are representative of three independent experiments. ***p < 0.001, vs the control group
Fig 5: PAI-1 promotes colony formation and cell viability and decreases cisplatin-induced apoptosis of ESCC cells in vitro.a, b The effect of PAI-1 on proliferation of KYSE-30 and KYSE-450 cells was measured by a colony formation assay. c, d The effect of PAI-1 on proliferation of KYSE-30 and KYSE-450 cells was measured by CCK-8 assays using different concentrations of PAI-1 (50 and 100 ng/ml). e, f The effect of PAI-1 on cisplatin-induced apoptosis of KYSE-30 and KYSE-450 cells was analyzed by the Annexin V-FITC Apoptosis Detection Kit. The results are representative of three independent experiments. **p < 0.01, ***p < 0.001, vs the control group
Supplier Page from Abcam for Human PAI1 ELISA Kit (SERPINE1)