Disertasi

Aktivitas Ekstrak Kapang Phomopsis sp. strain Sir-G5 dari Daun Sirsak dalam Menghambat Pertumbuhan Kanker Payudara Tikus Sprague-Dawley yang Diinduksi DMBA = ctivity of Phomopsis sp. strain Sir-G5 Fungi Extract in Inhibiting Breast Cancer Growth in Sprague-Dawley Rats Induced by DMBA.

Latar Belakang: Kanker merupakan penyebab sekitar 30% kematian dini pada orang dewasa, dengan kasus terbanyak adalah kanker payudara. Ekstrak Phomopsis sp. memiliki potensi sebagai antikanker payudara karena mampu menghambat sel MCF-7 (IC50 < 20 ppm) dan menurunkan volume tumor pada tikus uji. Belum diketahui bagaimana mekanisme molekular dari ekstrak Phomopsis sp. dalam mengatasi kanker payudara. Penelitian ini bertujuan menganalisis pengaruh pemberian ekstrak Phomopsis sp. dalam menurunkan volume tumor payudara dan mekanisme molekularnya terhadap proliferasi sel, apoptosis dan sistem imun, secara in silico dan in vivo. Metode: Uji in silico menggunakan molecular docking antara senyawa-senyawa yang terdapat di dalam ekstrak Phomopsis dengan REα, HER2, CDK4/6, dan TK1. Ligan terpilih dilanjutkan ke proses molecular dynamic. Uji in vivo dilakukan terhadap tikus Sprague-Dawley betina yang dibagi menjadi 6 kelompok yaitu kelompok tikus normal (N), kelompok tikus kanker payudara yang diberi terapi tamoksifen 10 mg/kgBB (kontrol positif, K+), akuades (kontrol negatif, K-), ekstrak Phomopsis dosis 10 mg/kgBB (Pho1), 20 mg/kgBB (Pho2), dan dosis 40 mg/kgBB (Pho3). Induksi kanker payudara menggunakan DMBA 20 mg/kgBB secara intragastric sebanyak 11 kali (2x/minggu). Terapi dimulai setelah terbentuk nodul di payudara dengan volume 1-2 cm3. Pengambilan darah dilakukan setelah pemberian DMBA dan sebelum tikus diterminasi. Setelah 6 minggu perlakuan, tikus diterminasi dan diambil jaringan tumor payudaranya untuk analisis IHK, lalu dinilai ekspresi REα, HER2, cyclin-D1 dan p53. Analisis ELISA dilakukan untuk mengukur konsentrasi TK1, IFN-γ, TNF-α dan TGF-β dari serum darah. Hasil: Uji in silico menunjukkan adanya 4 senyawa potensial pada ekstrak Phomopsis, yaitu 3-[(4- hydroxyphenyl)methyl]-octahydropyrrolo[1,2-a]pyrazine-1,4-dione, chalcone, 1-3-7- trihydroxy-6-methoxy-4-5-diisoprenylxanthone, dan 4-methoxy-chalcone. Senyawa 3-[(4- hydroxyphenyl)methyl]-octahydropyrrolo[1,2-a]pyrazine-1,4-dione menunjukkan kestabilan ikatannya dengan HER2 pada simulasi molecular dynamic. Uji in vivo menunjukkan bahwa ekstrak Phomopsis mampu menurunkan volume tumor setara dengan kelompok K+ dan berbeda signifikan (p < 0.05) dibandingkan kelompok K-. Ekstrak Phomopsis dosis 20 mg/kgBB mampu menurunkan ekspresi REα, HER2 dan cyclin-D1, meningkatkan ekspresi p53, serta menurunkan konsentrasi TGF-β. Kesimpulan: Ekstrak Phomopsis dosis 20 mg/kgBB memiliki potensi untuk mengobati kanker payudara pada tikus SD yang diinduksi DMBA.
Keywords: apoptosis, ekstrak Phomopsis, imun, kanker payudara, proliferasi.


Background: Cancer accounts for about 30% of premature deaths in adults, with breast cancer being the most prevalent case. Phomopsis sp. extract has potential as an anti-breast cancer agent as it can inhibit MCF-7 cells (IC50 < 20 ppm) and reduce tumor volume in breast cancer rats. The molecular mechanism of how Phomopsis sp. extract reduce the growth of breast cancer is still unknown. This study aims to analyze the effect of Phomopsis sp. extract in reducing breast tumor volume and its molecular mechanisms on cell proliferation, apoptosis, and the immune system, both in silico and in vivo. Methods: An in silico study was conducted using molecular docking between the compounds found in Phomopsis extract and REα, HER2, CDK4/6, and TK1. Selected ligands were then subjected to molecular dynamics analysis. The in vivo study was carried out on female Sprague-Dawley rats, divided into 6 groups: normal rats (N), breast cancer rats treated with 10 mg/kgBW tamoxifen (positive control, K+), aquadest (negative control, K-), Phomopsis extract at doses of 10 mg/kgBW (Pho1), 20 mg/kgBW (Pho2), and 40 mg/kgBW (Pho3). Breast cancer was induced using 20 mg/kgBW DMBA administered intragastrically 11 times (2x/week). Therapy administration began after nodules developed in the breast with a volume of 1-2 cm3. Blood sampling was conducted after DMBA administration and before the rats were terminated. After six weeks of treatment, the rats were terminated and their breast tumor tissue was collected for IHC analysis, followed by assessment of REα, HER2, cyclin-D1, and p53 expression. ELISA analysis was performed to measure the concentration of TK1, IFN-γ, TNF-α, and TGF-β from blood serum. Results: In silico study revealed the presence of four potential compounds in the Phomopsis extract: 3-[(4-hydroxyphenyl)methyl]-octahydropyrrolo[1,2-a]pyrazine- 1,4-dione, chalcone, 1-3-7-trihydroxy-6-methoxy-4-5-diisoprenylxanthone, and 4- methoxy-chalcone. The compound 3-[(4-hydroxyphenyl)methyl]-octahydropyrrolo[1,2- a]pyrazine-1,4-dione demonstrated stable binding with HER2 in molecular dynamic simulations. In vivo study showed that Phomopsis extract was able to reduce tumor volume to a level comparable to the K+ group and significantly different (p < 0.05) from the K- group. A 20 mg/kgBW dose of Phomopsis extract was able to reduce the expression of ERα, HER2, and cyclin-D1, increase p53 expression, and lower TGF-β concentrations. Conclusion: A 20 mg/kgBW dose of Phomopsis extract has the potential to treat breast cancer in DMBA-induced SD rats.
Keywords: apoptosis, breast cancer, immune, Phomopsis extract, proliferation.