Myogenetic Oligodeoxynucleotides as Anti-Nucleolin Aptamers Inhibit the Growth of Embryonal Rhabdomyosarcoma Cells

Area of Science:

• Oncology
• Molecular Biology
• Biochemistry

Background:

• Embryonal rhabdomyosarcoma (ERMS) is a muscle-derived tumor with retained myogenic potential.
• Nucleolin is a protein involved in cell proliferation and differentiation, found in myoblasts.
• Myogenetic oligodeoxynucleotides (myoDNs), such as iSN04 and AS1411, act as anti-nucleolin aptamers with potential anti-proliferative and differentiation-inducing effects.

Purpose of the Study:

• To investigate the in vitro effects of iSN04 and AS1411 on the growth of patient-derived ERMS cell lines.
• To determine if ERMS cells express nucleolin and if anti-nucleolin aptamers can inhibit their growth.
• To explore the mechanisms by which these aptamers affect ERMS cell proliferation, cell cycle, and myogenesis.

Main Methods:

• Utilized RT-PCR and immunostaining to confirm nucleolin expression in ERMS cell lines (ERMS1, KYM1, RD).
• Assessed cell proliferation using EdU incorporation assays and cell cycle status via phosphorylated histone H3 staining.
• Evaluated myogenesis through myosin heavy chain immunostaining and tumor sphere formation in 3D culture.

Main Results:

• Nucleolin was abundantly expressed in all tested ERMS cell lines, similar to myoblasts.
• Both iSN04 and AS1411 significantly reduced ERMS cell numbers, with iSN04 notably inhibiting proliferation (EdU+ cells) and suppressing the cell cycle.
• The aptamers partially promoted myogenesis and disrupted tumor sphere formation, indicating anti-tumorigenic effects without inducing apoptosis.

Conclusions:

• ERMS cells express nucleolin, making them susceptible to inhibition by anti-nucleolin aptamers.
• iSN04 and AS1411 demonstrate significant anti-proliferative and tumor growth-inhibiting effects on ERMS cells in vitro.
• These findings support the potential of anti-nucleolin aptamers as novel nucleic acid-based therapeutic agents for ERMS chemotherapy.