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B7-H3 silencing increases paclitaxel sensitivity by abrogating Jak2/Stat3 phosphorylation
Hao Liu1, Christina Tekle, Yih-Wen Chen
1Mitchell Cancer Institute, University of South Alabama, Mobile, Alabama 36604, USA.
B7-H3 protein promotes paclitaxel resistance in breast cancer cells by activating the Jak2/Stat3 pathway. Silencing B7-H3 enhances chemotherapy effectiveness and reduces tumor growth, offering new therapeutic targets.
Area of Science:
- Oncology
- Molecular Biology
- Immunology
Background:
- B7-H3 protein expression correlates with poor prognosis in various cancers.
- Previous research linked B7-H3 to tumor cell migration and invasion.
Purpose of the Study:
- To investigate the role of B7-H3 in chemoresistance in breast cancer.
- To elucidate the underlying mechanisms of B7-H3-mediated drug resistance.
Main Methods:
- Utilized short hairpin RNA (shRNA) and short interfering RNA (siRNA) for B7-H3 gene silencing.
- Assessed paclitaxel sensitivity, apoptosis, and Western blotting for protein phosphorylation (Jak2, Stat3) and expression (Mcl-1, survivin).
- Conducted in vivo animal experiments with B7-H3 knockdown xenografts.
Main Results:
- B7-H3 knockdown increased breast cancer cell sensitivity to paclitaxel by enhancing apoptosis.
- Overexpression of B7-H3 conferred resistance to paclitaxel.
- B7-H3 silencing reduced Jak2 and Stat3 phosphorylation and downstream targets Mcl-1 and survivin.
- In vivo, B7-H3 knockdown tumors showed slower growth and enhanced response to paclitaxel.
Conclusions:
- B7-H3 induces paclitaxel resistance in breast cancer, partly through the Jak2/Stat3 pathway.
- Targeting B7-H3 may overcome chemoresistance and improve therapeutic outcomes in breast cancer patients.
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