Abstract:

Objective To investigate the effects of long non-coding RNA （lncRNA） cancer susceptibility candidate 19 （CASC19） on the proliferation，migration and invasion of breast cancer cells by regulating the microRNA-410-3p （miR-410-3p）/laminin γ1 （LAMC1） signaling pathway. Methods A total of 53 pairs of breast cancer tissues and adjacent tissues of patients treated at Shiyan Renmin Hospital of Hubei Province from January 2023 to January 2024 were collected. The breast cancer MCF-7 cells were divided into the NC group，the sh-NC group，the sh-CASC19 group，the sh-CASC19+anti-NC group，and the sh-CASC19+anti-miR-410-3p group. The interaction between CASC19 and miR-410-3p，and between miR-410-3p and LAMC1 were verified by dual-luciferase reporter gene assay. The expression levels of CASC19，miR-410-3p and LAMC1 mRNA of MCF-7 cells in breast cancer tissues and adjacent tissues and in each group were detected by quantitative real-time PCR，cell proliferation was measured by EdU staining and CCK-8 assay，cell migration ability was evaluated by scratch assay，cell invasion ability was determined by Transwell assay，Western blotting was applied to detect the expression of proliferating cell nuclear antigen （PCNA），LAMC1，and matrix metalloproteinase-2 （MMP-2） proteins. Results The relative expression levels of CASC19 in adjacent tissues and breast cancer tissues were 1.01±0.30 and 1.65±0.31，respectively，miR-410-3p were 0.99±0.17 and 0.53±0.15，respectively，and LAMC1 were 1.00±0.29 and 1.48±0.31，respectively，with statistically significant differences （t=37.92，P<0.001； t=37.87，P<0.001； t=21.24，P<0.001）. The results of the dual-luciferase reporter gene assay showed that，CASC19 could target and negatively regulate miR-410-3p，and miR-410-3p could target and negatively regulate LAMC1. The relative expression levels of CASC19 in breast cancer MCF-7 cells from the NC，sh-NC，sh-CASC19，sh-CASC19+anti-NC，and sh-CASC19+anti-miR-410-3p groups were 1.01±0.16，0.96±0.16，0.37±0.13，0.34±0.11，0.35±0.11，respectively，miR-410-3p were 1.00±0.33，1.07±0.34，1.92±0.38，1.88±0.39，1.34±0.37，respectively，and LAMC1 mRNA were 1.00±0.17，1.05±0.17，0.44±0.13，0.41±0.13，0.89±0.15，respectively，with statistically significant differences （F=39.05，P<0.001； F=8.72，P<0.001； F=25.21，P<0.001）. Compared with the NC and sh-NC groups，the expression of CASC19 in the sh-CASC19，sh-CASC19+anti-NC，and sh-CASC19+anti-miR-410-3p groups decreased significantly （all P<0.05），the expression of miR-410-3p in sh-CASC19 group and sh-CASC19+anti-NC group increased significantly，while the expression of LAMC1 mRNA decreased significantly （all P<0.05）. Compared with the sh-CASC19 and sh-CASC19+anti-NC groups，the expression of miR-410-3p in the sh-CASC19+anti-miR-410-3p group decreased significantly，while the expression of LAMC1 increased significantly （all P<0.05）. The EdU-positive cell rates in the five groups were （45.93±5.04）%，（46.07±5.13）%，（19.26±3.25）%，（20.43±3.36）%，（37.85±4.86）%，respectively，the cell viability values were （100.00±0.00）%，（97.26±9.87）%，（46.27±7.12）%，（47.23±7.08）%，and （86.39±9.05）%，respectively，with statistically significant differences （F=54.34，P<0.001； F=76.76，P<0.001）. The scratch healing rates were （47.85±4.90）%，（48.03±4.87）%，（23.97±3.51）%，（23.42±3.26）%，and （39.54±4.12）%，respectively，the numbers of invasion were 114.62±10.98，113.78±11.87，64.53±9.41，65.14±9.04，97.86±10.27，respectively，with statistically significant differences （F=51.26，P<0.001； F=34.81，P<0.001）. The protein expression levels of PCNA were 1.14±0.14，1.17±0.15，0.34±0.10，0.36±0.11，0.93±0.13，respectively，LAMC1 were 1.37±0.15，1.32±0.14，0.59±0.09，0.61±0.09，and 1.18±0.12，respectively，MMP-2 were 0.93±0.13，0.88±0.10，0.23±0.07，0.25±0.08，0.76±0.10，respectively，with statistically significant differences （F=62.32，P<0.001； F=58.94，P<0.001； F=73.41，P<0.001）. Compared with the NC and sh-NC groups，the EdU-positive cell rate，cell viability value，scratch healing rate，number of invasion，and protein expression levels of PCNA，LAMC1，and MMP-2 in the sh-CASC19 and sh-CASC19+anti-NC groups decreased significantly （all P<0.05）. Compared with the sh-CASC19 and sh-CASC19+anti-NC groups，these indices in the sh-CASC19+anti-miR-410-3p group increased significantly （all P<0.05）. Conclusions lncRNA CASC19 may promote the proliferation，migration，and invasion of breast cancer cells by regulating the miR-410-3p/LAMC1 signaling pathway.

Key words: Breast neoplasms, Cell proliferation, Cell movement, Neoplasm invasiveness, Micro- RNA-410-3p, Cancer susceptibility candidate gene, Laminin γ1