Aktivitas Antikanker Senyawa BornUSU I dan BornUSU II dengan Target Kerja Reseptor Estrogen Alfa (REα)

Abstract

BornUSU I atau Boronhafagama I (1,5-bis(4-hydroxyphenyl)-3-oxa-1,5- diaza-2,4-diboropentane-2,4-diol) dan BornUSU II atau Boronhafagama II (1-(4)- hydroxynaphthalen-1-yl)-5-(4-hydroxyphenyl)-3-oxa-1,5-diaza-2,4diboropentane2,4 diol) adalah senyawa turunan boron dan merupakan kandidat Boron Neutron Captured Therapy (BNCT) yang merupakan terapi target spesifik tertentu pada sel kanker. Reseptor Estrogen Alfa (REα) berperan penting dalam pertumbuhan dan perkembangan penyakit kanker payudara. Tamoksifen (TAM) telah digunakan untuk terapi kanker payudara wanita selama empat dekade. TAM memiliki risiko serius yaitu berupa kanker dan hiperplasi endometrium. Penelitian ini bertujuan untuk membuktikan aktivitas antikanker BornUSU I, BornUSU II, dan 4- hydroxytamoxifen (4-OHT) sebagai senyawa pembanding secara in silico, serta membuktikan aktivitas antikanker BornUSU I secara in vitro. Pembuktian in silico dengan sistem docking digunakan program Protein Ligand ANT System (PLANTS) yang divisualisasikan dengan program Pymol. Sedangkan secara in vitro, digunakan metode MTT terhadap sel T47D dan MCF-7 untuk mengetahui efek sitotoksisitas BornUSU I, dan TAM sebagai kontrol positif dengan masa inkubasi selama 24 dan 48 jam, selanjutnya aktivitas penghambatan siklus sel dan apoptosis dilakukan dengan metode flow cytometry. Analisis ekspresi REα dilakukan dengan metode semi-kuantitatif Reverse Transcription-Polymerase Chain Reaction (RT-PCR). Hasil skor docking BornUSU I, BornUSU II, dan 4-OHT terhadap REα, masing-masing ‒92,17; ‒100,19; dan ‒99,09. BornUSU I yang berhasil disintesis, kemudian aktivitas antikankernya diuji secara in vitro. Nilai IC50 terendah pada uji sitotoksik BornUSU I dengan subjek sel MCF-7 adalah pada masa inkubasi selama 48 jam (34,32 ± 0,27 μM) dibandingkan dengan masa inkubasi selama 24 jam (93,41 ± 0,32 μM), sedangkan pada subjek sel T47D juga diperoleh pada masa inkubasi selama 48 jam (44,63 ± 0,23 μM) dibandingkan dengan masa inkubasi selama 24 jam (72,61 ± 0,82 μM). Nilai Indeks Selektivitas (IS) terbesar BornUSU I dengan subjek sel T47D adalah 6,69, sedangkan dengan subjek sel MCF-7 adalah 8,70. BornUSU I menghambat siklus sel pada fase S, dan mampu memacu apoptosis awal, serta dapat menekan ekspresi gen REα pada sel MCF-7 dan T47D. Berdasarkan pemaparan di atas, dapat disimpulkan bahwa BornUSU I dan BornUSU II menghambat REα secara in silico, dan BornUSU I secara selektif memiliki aktivitas antikanker terhadap sel MCF-7 dan T47D secara in vitro, sehingga berpotensi menjadi agen antikanker baru terutama pada terapi kanker payudara.

BornUSU I or Boronhafagama I (1,5-bis(4-hydroxyphenyl)-3-oxa-1,5-diaza- 2,4-diboropentane-2,4-diol) and BornUSU II or Boronhafagama II (1-(4- hydroxynaphthalen-1-yl)-5-(4-hydroxyphenyl)-3-oxa-1,5-diaza-2,4diboropentane2,4 diol) are boron derivate compounds and Boron Neutron Captured Theraphy (BNCT) candidates which are a specific target therapy for cancer cells. Estrogen Receptor Alpha (ERα) plays a critical role in the growth and development of breast cancer disease. Tamoxifen (TAM) has been used as a breast cancer treatment for roughly four decades. TAM has serious risks, for example the risk endometrial malignancy and hyperplasia. This study aims to determine anticancer activity of BornUSU I, BornUSU II, and 4-hydroxytamoxifen (4-OHT) as the comparative compound through in silico, also to determine anticancer activity of BornUSU I through in vitro. In silico proving with docking system was used Protein Ligand ANT System (PLANTS) programme and visualized by Pymol programme. Whereas in vitro study, was using MTT method towards T47D and MCF-7 cell lines to determine cytotoxic effect of BornUSU I, and TAM as a positive control with incubation period for 24h and 48h, then the cell cycle inhibition activity and apoptosis stimulation were carried out by flow cytometry method. The measurement of ERα gene expression level was carried out using the semi-quantitative molecular Reverse Transcription-Polymerase Chain Reaction (RT-PCR) method. The docking score result of BornUSU I, BornUSU II, and 4-OHT inhibited ERα was ‒92.17; ‒100.19; and ‒99.09, respectively. BornUSU I which had been successfully synthesized, were tested by in vitro anticancer activity. The lowest IC50 value of BornUSU I cytotoxic test against MCF-7 cells was on incubation period for 48h (34.32 ± 0.27 μM) compared by the incubation period for 24h (93.41 ± 0.32 μM), while the lowest IC50 value against T47D cells also was on incubation period for 48h (44.63 ± 0.23 μM) compared by the incubation period for 24h (72.61 ± 0.82 μM). The highest Index Selectivity (IS) value of BornUSU I against T47D cells was 6.69, while the highest IS value against MCF-7 cells was 8.70. BornUSU I inhibited cell cycle at S phase, and stimulated the first apoptotic phase, also suppressed the ERα expression in MCF-7 and T47D cells. Based on the explanation above, it can be concluded that BornUSU I and BornUSU II inhibit ERα by in silico, and BornUSU I has the anticancer activity towards MCF-7 and T47D cells selectively by in vitro, so become potentially as the new anticancer agent, mainly in breast cancer therapy.