STAT3 blockade with shRNA enhances radiosensitivity in Hep-2 human laryngeal squamous carcinoma cells.
Signal transducer and activator of transcription 3 (STAT3) is an oncogene aberrantly activated in many human tumors. We studied whether radiation combined with STAT3 siRNA enhances radiosensitivity of Hep-2 human laryngeal squamous carcinoma cells (Hep-2 cells). Firstly, STAT3 targeting recombinant plasmid was constructed. Hep-2 cells were transfected with expression vector of STAT3 siRNA using Lipofectamine 2000. Semiquantitive RT-PCR detected effective STAT3 mRNA down-regulation by STAT3 siRNA. Secondly, Hep-2 cells were radiated with different doses of gamma-rays after transfection with STAT3 small interference RNA (siRNA). MTT assay showed cell proliferation decreased significantly (P<0.05) after STAT3 siRNA transfection combined with radiation. Thirdly, flow cytometry (FCM) demonstrated that cell apoptosis of combined treatment group increased significantly (P<0.05) and exhibited time dependency after 6 Gy irradiation (P<0.05). Simultaneously, STAT3, p-STAT3, Bcl-2, VEGF, p53 protein levels decreased in Hep-2 cells, with positive correlations between level of p-STAT3 and levels of Bcl-2, VEGF, p53, respectively (r=0.974, 0.988, 0.976, all P<0.01). Above all, specific siRNA targeting STAT3 gene is able to enhance the radiosensitivity in Hep-2 cells by regulating expression of Bcl-2, VEGF and p53 proteins.
Li
Xiaoming
X
Department of Otolaryngology-Head and Neck Surgery, Bethune International Peace Hospital, Shijiazhuang, Hebei Province, PR China. xmlmo@126.com
Wang
Hairu
H
Lu
Xiuying
X
Di
Bin
B
D017209:Apoptosis / Q000187:drug effects / Q000528:radiation effects; D001483:Base Sequence; D002294:Carcinoma, Squamous Cell / Q000235:genetics / Q000473:pathology / Q000532:radiotherapy*; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects / Q000528:radiation effects; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects; D006801:Humans; D007822:Laryngeal Neoplasms / Q000235:genetics / Q000473:pathology / Q000532:radiotherapy*; D008969:Molecular Sequence Data; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000235:genetics / Q000502:physiology; D034741:RNA, Small Interfering / Q000235:genetics / Q000494:pharmacology*; D011829:Radiation Dosage; D011836:Radiation Tolerance / Q000187:drug effects* / Q000235:genetics; D011838:Radiation-Sensitizing Agents / Q000494:pharmacology; D050796:STAT3 Transcription Factor / Q000037:antagonists & inhibitors* / Q000235:genetics; D014162:Transfection; D016159:Tumor Suppressor Protein p53 / Q000235:genetics / Q000502:physiology; D042461:Vascular Endothelial Growth Factor A / Q000235:genetics / Q000502:physiology
D019253:Proto-Oncogene Proteins c-bcl-2; D034741:RNA, Small Interfering; D011838:Radiation-Sensitizing Agents; D050796:STAT3 Transcription Factor; C494086:STAT3 protein, human; D016159:Tumor Suppressor Protein p53; C467484:VEGFA protein, human; D042461:Vascular Endothelial Growth Factor A