Background: Gastric cancer (GC) is a frequent disease with a poor prognosis worldwide. Circular RNAs (circRNAs) are considered to be important regulators that mediate the occurrence and development of cancers, including GC. However, the regulatory mechanism of circRNAs in GC progression is not fully understood.

Methods: The expression of circular RNA nuclear receptor-interacting protein 1 (circNRIP1), microRNA (miR)-148b-5p and Cysteine-rich 61 (CYR61) was gauged using quantitative real-time polymerase chain reaction (qRT-PCR). The stability of circNRIP1 was determined by Ribonuclease R (RNase R) assay.

Results: CircNRIP1 was upregulated in GC tissues and cells, and it was a stable circular RNA. CircNRIP1 overexpression facilitated cell proliferation, cycle progression, colony formation, invasion, migration and angiogenesis, while circNRIP1 knockdown exhibited opposite effects in GC cells. Mechanistically, miR-148b-5p could mediate the regulation of circNRIP1 on GC cell progression by serving as a target of circNRIP1. Furthermore, miR-148b-5p inhibited GC cell malignant behaviors by sponging CYR61. Meanwhile, circNRIP1 could regulate CYR61 expression via downregulating miR-148b-5p. Besides, circNRIP1 knockdown suppressed tumor growth in xenograft models.

Conclusion: CircNRIP1 contributed to GC progression through regulating the miR-148b-5p/CYR61 axis, hinting that circNRIP1 might be a new target for GC treatment.