Combined Detection of Serum MiR-221-3p and MiR-122-5p Expression in Diagnosis and Prognosis of Gastric Cancer

Abstract

Purpose: To investigate the clinical value of serum miR-221-3p and miR-122-5p expression levels in the diagnosis and prognosis of gastric cancer.

Materials and methods: Serum samples from 141 gastric cancer cases (gastric cancer group), 110 gastric polyps (gastric polyp group), and 75 healthy people (healthy control) were used to detect miR-221-3p and miR-122-5p expression using real-time reverse transcription polymerase chain reaction.

Results: Serum miR-221-3p expression was significantly higher in the gastric cancer group than in the gastric polyp group, and it was significantly lower than that before operation. The miR-221-3p expression was significantly higher in the death group than in the survival group. The proliferation and migration ability significantly increased and the apoptosis rate significantly decreased by miR-221-3p transfection in gastric cancer cells. In contrast, the function of miR-122-5p in gastric cancer cells was opposite of miR-221-3p. Serum miR-221-3p expression was negatively correlated with that of miR-122-5p in gastric cancer. Serum miR-221-3p and miR-122-5p expressions were significantly correlated with the degree of differentiation, tumor, node, metastasis stage, lymph node metastasis, and invasion depth. miR-221-3p and miR-122-5p expression levels were independent prognostic factors for postoperative gastric cancer. In the diagnosis and predicting prognosis of gastric cancer, receiver operating characteristic analysis revealed that the area under curve of combined detection of serum miR-221-3p and miR-122-5p expression had a greater diagnostic effect than either single maker.

Conclusions: The miR-221-3p and miR-122-5p are involved in the development of gastric cancer, and they have important clinical values in gastric cancer diagnosis and prognosis.

Keywords: Diagnosis; Gastric cancer; MicroRNAs; Prognosis; Real-time polymerase chain reaction.

Fig. 1. Clinical value of serum miR-221-3p and miR-122-5p levels in diagnosis and prognosis. (A, B) Serum miR-221-3p and miR-122-5p expression levels in each group. (A) Serum miR-221-3p expression levels in each group, (B) serum miR-221-3p expression levels in each group. Compared to healthy control, ^*P<0.01; compared to gastric polyp group, ^†P<0.01; compared to pre-operation, ^‡P<0.01.(C) Correlation between serum miR-221-3p and miR-122-5p expression in gastric cancer. (D) Comparison of serum miR-221-3p and miR-122-5p expression in the area under the curve of diagnosis of gastric cancer. (E) Clinical prediction value of death within 2 years with serum miR-221-3p and miR-122-5p levels. Compared to survival group, ^*P<0.01. (F) Comparison of serum miR-221-3p and miR-122-5p levels in predicting death within 2 years.

Fig. 2. Impact of gastric cancer cells on proliferation after transfection with miR-221-3p and miR-122-5p plasmids. (A) miR-221-3p and miR-122-5p expression in gastric cancer cells after plasmid transfection. Compared to MGC-803 and MKN28, ^*P<0.01. (B) Impact of miR-221-3p and miR-122-5p on proliferation of gastric cancer cells after transfection (72 hours×200). (C and D) Impact of miR-221-3p and miR-122-5p on proliferation of gastric cancer cells at different time points. (C) Impact of miR-221-3p on gastric cancer cell proliferation at different time points, (D) Impact of miR-122-5p on gastric cancer cell proliferation at different time points. Compared to 24 hours, ^*P<0.01.

Fig. 3. Impact of gastric cancer cells on migration and apoptosis after miR-221-3p and miR-122-5p plasmid transfection. (A) Impact of miR-221-3p and miR-122-5p on migration of gastric cancer cells after transfection in upper chamber (24 hours×200). (B and C) Impact of transfection of miR-221-3p and miR-122-5p plasmids on gastric cancer cell migration for 24 hours. (B) miR-221-3p on migration of gastric cancer cells, (C) miR-122-5p on migration of gastric cancer cells. Compared to negative control, ^*P<0.01. (D) Gastric cancer cell apoptosis using flow cytometry after 24 hours of cell culture. (E and F) Apoptosis percentage of gastric cancer cells using flow cytometry after 24 hours of cell culture. (E) miR-221-3p on apoptosis percentage of gastric cancer cells, (F) miR-122-5p on apoptosis percentage of gastric cancer cells. Compared to negative control, ^*P<0.01.