Objective:To investigate the expression of long non-coding RNA (Lnc RNA) RP5-919F19 in gastric cancer tissues and its correlation with gastric cancer invasion and metastasis.Methods:Non-tumor gastric mucosa (more than 3cm away from the cancer tissue) and gastric adenocarcinoma tissues were collected from Jan. 2020 to Jan. 2022 in our hospital. TRIzol kit was used to extract total RNA from cells and tissues, and reverse transcription kit was used to reverse transcribed RNA into cDNA. Quantitative real-time PCR kit was used for quantitative analysis. SGC-7901 and AGS human gastric cancer cells were used to construct RP5-919F19 knockdown and overexpression models. CCK-8 assay was used to confirm cell proliferation, and Transwell invasion assay was used to confirm the invasion ability of gastric cancer cells.Results:The expression of RP5-919F19 was detected in 79 cases of gastric cancer tissues and adjacent normal tissues, and it was found that the relative expression of RP5-919F19 in gastric cancer tissues was 1.51±0.05 significantly higher than that of 0.82±0.04 in adjacent normal tissues ( P<0.05) . The levels of RP5-919F19 in patients with different pathological conditions were compared and analyzed. The results showed that there were statistically significant differences in RP5-919F19 expression in patients with different TNM stages, distant metastasis, lymph node metastasis and different depth of invasion ( P<0.05) . There was no significant difference in RP5-919F19 expression among patients with different tumor sizes, ages and genders ( P>0.05) . AGS gastric cancer cells were transfected with RP5-919F19 overexpression plasmid and control plasmid, and the efficiency of RP5-919F19 was detected. The results showed that the expression level of RP5-919F19 in the overexpression group was 1.83±0.14 higher than that of 0.82±0.05 in the control group ( P<0.05) . SGC-7901 gastric cancer cells were transfected with RP5-919F19 knockout vector and control vector, and the efficiency of RP5-919F19 was detected. The results showed that the expression level of RP5-919F19 in the knockout group was 0.42±0.07 lower than that of 0.89±0.08 in the control group ( P<0.05) . CCK-8 was used to detect the proliferation ability of gastric cancer cells. The results showed that the proliferation ability of AGS cells in RP5-919F19 overexpression group was significantly increased compared with that of the control group at 24 and 48h after culture ( P<0.05) . However, the proliferation ability of SGC-7901 cells in RP5-919F19 knockdown group was lower than that in the control group at 24 h and 48 h ( P<0.05) . Transwell invasion assay showed that the invasion and migration abilities of AGS cells in RP5-919F19 overexpression group were higher than those in the control group ( P<0.05) , and the invasion and migration abilities of SGC-7901 cells in RP5-919F19 knockout group were lower than those in the control group ( P<0.05) . Western blot showed that compared with control cells, the expression of MMP-2 and MMP-9COPS7A proteins in down-regulated Lnc RNA RP5-919F19 SGC-7901 cells was decreased. Conclusion:The expression of LncRNA RP5-919F19 is abnormally increased in gastric cancer tissues, and the increased expression of RP5-919F19 can promote the proliferation and metastasis of gastric cancer cells.