Disertasi

Penghambatan ekspresi gen manganese superoksida dismutase pada galur sel glioblastoma multiforme T98G: dampaknya terhadap ketahanan hidup dan stres oksidatif akibat induksi rotenon. = Supression of manganese superoxide dismutase gene expression on glioblastoma multiforme T98G cell line: its impacts on cell survival and oxidative stress induced by rotenone.

Penelitian ini menganalisis dampak penghambatan ekspresi MnSOD terhadap ketahanan hidup sel Glioblastoma Multiforrne dan induksi stres oksidatif akibat rotenon. Penelitian ini terbagi atas: 1). Penghambatan ekspresi gen MnSOD; 2). Induksi stres oksidatif dengan rotenon; 3). Penghambatan ekspresi gen MnSOD yang diikuti dengan induksi rotenon. Sampel adalah galur sel glioblastoma multiforme manusia T98G. Penghambatan ekspresi gen MnSOD dilakukan dengan transfeksi in vitro siRNA MnSOD. Ketahanan hidup sel dianalisis dengan mengukur viabilitas, proliferasi dan apoptosis sel. Transfeksi in vitro siRNA MnSOD dapat menghambat ekspresi mRNA, protein dan aktivitas spesik enzim MnSOD. Sedangkan induksi rotenon meningkatan ekspresi mRNA MnSOD, namun pada tingkat protein dan aktivitas spesifik terjadi penurunan bermakna. Pada saat transfeksi terse but diikuti induksi rotenon temyata ekspresi mRN A MnSOD tidak terhambat, kemungkinan karena dosis siRNA yang masih kurang atau aktifnya antioksidan endogen yang lain. Transfeksi siRNA MnSOD dan induksi rotenon meningkatkan anion superoksida, menurunkan viabilitas dan proliferasi sel serta meningkatkan apoptosis. Namun pada saat transfeksi diikuti induksi rotenon terjadi penurunan bermakna anion superoksida dan apoptosis dibandingkan dengan sel yang hanya diinduksi rotenon. Disimpulkan bahwa penghambatan ekspresi gen MnSOD atau induksi rotenon dapat menurunkan ketahanan hidup sel T98G Namun, apabila penghambatan ekspresi MnSOD tersebut diikuti dengan induksi rotenon temyata terjadi penurunan bermakna radikal superoksida dan apoptosis. Radikal superoksida kemungkinan berperan pada proses apoptosis sel T98G tersebut.
Kata Kunci: galur sel T98G, transfeksi siRNA MnSOD, rotenon, ketahanan hidup sel, stres oksidatif.



This study analyzed the effects of suppression of MnSOD gene expression on survival in glioblastoma multiforme cells and oxidative stress induced by rotenone. This study was divided - into: 1). Suppression of MnSOD gene expression; 2) Oxidative stress induction by rotenone; 3). Suppression of MnSOD gene expression followed by rotenone induction. Sample cell used was human glioblastoma multiforme T98G cell line. Suppression of MnSOD gene expression was performed by in vitro MnSOD-siRNA transfection. Cell survival was analyzed by measuring cell viability, proliferation and apoptosis. In vitro MnSOD-siRNA transfection could inhibit mRNA expression, protein level and specific activity of MnSOD enzyme. Rotenone induction showed increased MnSOD mRNA expression, while the protein level and specific activity of MnSOD decreased significantly. When the transfection followed by rotenone induction, MnSOD mRNA expression was not inhibited. It is possibly due to the siRNA dose was lacking or due to the activation of other endogenous antioxidant system. Transfection of MnSOD siRNA and rotenone induction increased superoxide anion, decreased cell viability, decreased proliferation cell and increased apoptosis. However, when transfection was followed by rotenone induction, superoxide anion and apoptosis significantly decreased compared to the cells with rotenone induction alone. We concluded that suppression of MnSOD gene expression or rotenone induction could significantly decreased T98G cell survival. However if the suppression of MnSOD expression followed by rotenone induction, superoxide anion and apoptosis significantly decreased. Superoxide radical might play role in T98G cell apoptosis process.
Key Words: T98G cell line, MnSOD siRNA transfection, rotenone, cell survival, oxidative stress.