Analysis of the subcellular location of FAM230B and its interaction with premature miR-302b in osteosarcoma

Introduction: FAM230B has been characterized as an oncogenic lncRNA in papillary thyroid cancer and gastric cancer, while its role in osteosarcoma (OS) is unclear. This research was conducted to analyze the interaction between FAM230B and miR-302b in OS.

Materials and methods: Paired OS and non-tumor tissues donated by 58 OS patients were subjected to RNA preparation and RT-qPCR to quantify the expression of FAM230B and miR-302b (both mature and premature). The subcellular location of FAM230B and its interaction with premature miR-320b were analyzed by cellular fractionation assay and RNA pull-down assay, respectively. The roles of FAM230B and miR-302b in OS cell movement were evaluated using Transwell assay.

Results: Increased FAM230B and premature miR-302b and decreased mature miR-302b were observed in OS. FAM230B was detected in both nuclear and cytoplasm samples and directly interacted with premature miR-302b. FAM230B overexpression in OS cells 143B and HOS decreased miR-302b maturation and increased cell invasion and migration, while miR-302b overexpression suppressed cell invasion and migration. FAM230B silencing restrained cell invasion and migration, and miR-302b inhibitor accelerated cell invasion and migration. MiR-302b knockdown significantly reversed the suppressive effects of shFAM230B on migration and invasion of 143B and HOS cells.

Conclusion: FAM230B is accumulated to high levels in OS and may serve as an endogenous competing RNA for premature miR-302b in the nucleus to promote OS cell invasion and migration.