Evaluasi Aktivitas Eksosom dan Sekretom Berbasis Sel Punca Mesenkimal Human Wharton’s Jelly pada Sel Kanker Payudara MDA-MB-231 terhadap Regulasi Ekspresi PD-L1

Salsabilla Kristinawati, drh. Retno Murwanti, M.P., Ph.D.; Prof. Dr.rer.nat. apt. Adam Hermawan, M.Sc.

2026 | Tesis | S2 Ilmu Farmasi

Triple-negative breast cancer (TNBC) merupakan subtipe kanker payudara yang sangat agresif dan memiliki kemampuan menghindari sistem imun melalui peningkatan ekspresi programmed death-ligand 1 (PD-L1). Pendekatan terapi berbasis sel punca, khususnya eksosom dan sekretom dari human Wharton’s Jelly (HWJ), menawarkan potensi sebagai terapi bebas sel karena mengandung molekul bioaktif seperti miRNA let-7 yang berperan dalam regulasi jalur persinyalan kanker. Penelitian ini bertujuan untuk mengevaluasi efek eksosom dan sekretom HWJ terhadap proliferasi, migrasi, distribusi siklus sel, serta regulasi ekspresi PD-L1 pada sel kanker payudara MDA-MB-231. Penelitian dilakukan melalui pendekatan in silico dan in vitro. Analisis bioinformatik digunakan untuk memprediksi keterlibatan miRNA let-7 dalam regulasi jalur PD-L1, khususnya melalui jalur PI3K dan p53. Uji in vitro meliputi uji sitotoksisitas menggunakan uji MTT, uji migrasi dengan scratch wound healing assay, analisis siklus sel menggunakan flow cytometry, serta analisis ekspresi gen PIK3CA, AKT1, NF-?B, CD274 (PD-L1), TP53, p21, dan CDH1 menggunakan qRT-PCR. Analisis statistik dilakukan dengan ANOVA (P < 0>

Hasil menunjukkan bahwa sekretom HWJ pada konsentrasi tinggi secara signifikan menurunkan viabilitas sel dan menghambat proliferasi, terutama setelah inkubasi 72 jam (P < 0> 0,05). Secara keseluruhan, sekretom HWJ menunjukkan peran ganda dalam modulasi proliferasi, migrasi, siklus sel, dan regulasi PD-L1 pada sel TNBC secara in vitro.

Triple-negative breast cancer (TNBC) is a highly aggressive subtype of breast cancer with the ability to evade the immune system through the expression of programmed death-ligand 1 (PD-L1). Human Wharton’s Jelly (HWJ)–based exosomes and secretome, which contain biological components such as miRNA let-7, have potential as cell-free therapies with immunomodulatory activity against cancer. This study aimed to evaluate the effects of HWJ exosomes and secretome on proliferation, migration, and regulation of PD-L1 expression in MDA-MB-231 breast cancer cells. The study was conducted using in silico and in vitro approaches. Bioinformatic analysis was employed to predict the involvement of miRNA let-7 in regulating the PD-L1 signaling pathway. In vitro assays included cytotoxicity assessment using the MTT assay, cell migration analysis using a scratch wound healing assay, cell cycle distribution analysis using flow cytometry, and gene expression analysis of PIK3CA, AKT1, and CD274 (PD-L1) using qRT-PCR. Statistical analysis was performed using ANOVA with GraphPad 10.0 software (P < 0>

In silico analysis indicated the involvement of the PI3K and p53 pathways in miRNA let-7–mediated regulation of PD-L1 in breast cancer. In vitro results showed that high concentrations of HWJ secretome significantly reduced cell viability, indicating inhibition of proliferation (P < 0>P < 0>P < 0>P < 0>PIK3CA, AKT1, NF-?B, CD274, and TP53 (P < 0>p21 and CDH1 (P < 0>P > 0.05), which is presumed to reflect the inert nature of HWJ exosomes toward MDA-MB-231 cells. This study demonstrates that HWJ secretome exerts a dual role in cancer by inhibiting proliferation and migration, regulating the cell cycle, and altering PD-L1 gene expression in vitro in MDA-MB-231 breast cancer cells.

Kata Kunci : Triple-Negative Breast Cancer, Wharton’s Jelly Mesenchymal Stem Cells, Eksosom, Sekretom, PD-L1