Plasmid-based STAT3-siRNA efficiently inhibits breast tumor growth and metastasis in mice
1State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, The People's Republic of China.
Abstract:
Signal transducer and activator of transcription 3 (STAT3) plays an important role in the tumor formation and metastasis. In this study, short hairpin RNA targeting STAT3 was cloned into pGenesil-2 plasmid vector and the effects of STAT3 silencing in 4T1 breast cancer cells were analyzed both in vitro and in vivo. Forty-eight hours after transfecting with pSi-STAT3, the expression level of STAT3, the upstream regulator and downstream targets were measured using Western blot. Moreover, the effects of pSi-STAT3 on migration and invasion in 4T1 cells were tested using wound-healing and tube formation assay. Furthermore, 4T1 subcutaneous mice model was used to evaluate the effects of pSi-STAT3 on tumor growth and metastasis. Proliferation, apoptosis, angiogenesis in tumor tissues and lung metastases were measured by PCNA, TUNEL, and CD31 immunostaining, respectively. Our results indicated that siRNA targeting STAT3 could significantly silence STAT3 expression in 4T1 breast cancer cells and result in inhibition of 4T1 breast cells migration and HUVECs tube formation. In vivo, pSi-STAT3 delayed tumor growth (pknockdown of STAT3 by plasmid-based siRNA might be a potential therapy against breast cancer.
Insights
Silencing signal transducer and activator of transcription 3 (STAT3) in breast cancer cells inhibits tumor growth and metastasis. This STAT3 knockdown shows potential as a novel therapy for breast cancer.
Area of Science:
- Oncology
- Molecular Biology
- Genetics
Background:
- Signal transducer and activator of transcription 3 (STAT3) is implicated in tumor formation and metastasis.
- Targeting STAT3 is a potential strategy for cancer therapy.
Purpose of the Study:
- To investigate the effects of STAT3 silencing on 4T1 breast cancer cells in vitro and in vivo.
- To evaluate the therapeutic potential of plasmid-based siRNA targeting STAT3.
Main Methods:
- STAT3 was silenced in 4T1 cells using short hairpin RNA (shRNA) delivered via pGenesil-2 plasmid.
- In vitro assays included Western blot, wound-healing, and tube formation assays.
- In vivo studies utilized a 4T1 subcutaneous mice model with analysis of tumor growth, metastasis, proliferation, apoptosis, and angiogenesis.
Main Results:
- STAT3 expression was significantly reduced in 4T1 cells following transfection with pSi-STAT3.
- STAT3 silencing inhibited 4T1 cell migration and human umbilical vein endothelial cell (HUVEC) tube formation.
- In vivo, pSi-STAT3 delayed tumor growth and reduced lung metastasis, with decreased proliferation and angiogenesis.
Conclusions:
- Plasmid-based siRNA targeting STAT3 effectively silences gene expression in breast cancer cells.
- STAT3 knockdown inhibits breast cancer cell migration, invasion, and angiogenesis.
- STAT3 knockdown demonstrates therapeutic potential against breast cancer growth and metastasis.
