Soluble PD-1 over-expression enhances the anti-tumor effect of senescence tumor cell vaccine against breast cancer cell growth in tumor-bearing mice
10.3969/j.issn.1673-4254.2018.01.004
- VernacularTitle:sPD-1过表达增强衰老肿瘤细胞疫苗抗小鼠乳腺癌作用
- Author:
Zehong CHEN
1
;
Huiwen LIN
;
Kang HU
;
Ruxiong SU
;
Nan LAI
;
Zike YANG
;
Shijun KANG
Author Information
1. 南方医科大学肿瘤中心//南方医科大学中西医结合医院
- Keywords:
sPD-1;
X-ray;
veliparib;
senescence tumor cell vaccine;
breast cancer
- From:
Journal of Southern Medical University
2018;38(1):20-26
- CountryChina
- Language:Chinese
-
Abstract:
Objective To investigate whether soluble PD-1 overexpression in 4T1 senescence tumor cells enhances the anti-tumor effect of senescence tumor cell vaccine (STCV) against breast tumor cells in a tumor-bearing mouse model. Methods 4T1 cells were treated with interferon-γ (IFN-γ) and the expression of PD-L1 was detected by flow cytometry. CCK8 assay was used to compare the cell proliferation activity between 4T1 cells and 4T1 cells infected by a lentiviral vector of sPD-1 (4T1/sPD-1 cells), and the expressions of sPD-1 mRNA and protein in 4T1/sPD-1 cells were detected using qPCR and Western blotting. The culture supernatant of 4T1/sPD-1 cells was added in 4T1 cells pre-treated with IFN-γ, and PD-1-positive 4T1 cells were detected with flow cytometry. Senescenceβ-galactosidase staining kit was used to detect the senescent 4T1 and 4T1/sPD-1 cells following exposure to X-ray radiation and Veliparib. Balb/c mice bearing subcutaneous 4T1 tumor xenografts were treated with injections of PBS, 4T1 STCV, or 4T1/sPD-1 STCV, and tumor growth was observed. Results Stimulation with IFN-γconcentration-dependently up-regulated PD-L1 expression by as much as (84.80 ± 1.03)％ in 4T1 cells (P<0.001). sPD-1 overexpression in 4T1 cells did not significantly affect the cell proliferation. Treatment of 4T1 cells with 4T1/sPD-1 cell culture supernatant significantly increased the proportion of PD-1 + cells from (6.893 ± 0.271)％ to (55.450 ± 0.555)％ (P<0.001). X-ray irradiation combined with Veliparib caused obvious senescence in 4T1 and 4T1/sPD-1 cells. In the tumor-preventing experiment, tumor formation occurred in all the mice in PBS group;28.787％of the mice in 4T1 STCV group and 55.556％in 4T1/sPD-1 STCV group showed no tumor formation. In the tumor treatment experiment, tumor formation occurred in all the mice in PBS groups while in 4T1 STCV and 4T1/sPD-1 STCV groups, 11.111％ and 38.89％ of the mice were tumor-free during the observation period, respectively. Conclusions Senescence tumor cells vaccine has anti-tumor effect against breast cancer in mice, and sPD-1 over-expression can enhance this effect of the vaccine.
