Objective: To screen the differentially expressed circular ribonucleic acids (circRNAs) related to gastric cancer and to explore their associations with the clinicopathological features of gastric cancer.
Patients and methods: Cancer tissues of 50 gastric cancer patients undergoing surgical resection in our hospital from April 2015 to December 2018 were collected as an experimental group, while the para-carcinoma tissues were used as the control group. First, the differentially expressed circRNAs were screened by analyzing the circRNA profile in the microarray. Then, the expression of hsa_circ_0006156 in tissues was detected via Reverse Transcription-quantitative Polymerase Chain Reaction (RT-qPCR) in both groups. The potential associations of the relative expression level of hsa_circ_0006156 with clinicopathological features and prognosis were analyzed according to the clinical data of gastric cancer patients.
Results: Six significantly downregulated circRNAs in gastric cancer patients were screened out. The results of RT-qPCR showed that the expression level of hsa_circ_0006156 was significantly lower in gastric cancer tissues than that in para-carcinoma tissues (p<0.05). Accordingly, 50 gastric cancer patients were divided into hsa_circ_0006156 high expression group and hsa_circ_0006156 low expression group based on the fold change of hsa_circ_0006156 in para-carcinoma tissues than that of gastric cancer tissues (fold change>3). The expression level of hsa_circ_0006156 was not correlated with the age and gender of gastric cancer patients (p>0.05) but correlated with the lymph node metastasis (p<0.05), nerve invasion (p<0.05), and degree of tumor differentiation (p<0.05). The expression level of hsa_circ_0006156 was also significantly associated with the progression-free survival (PFS) and overall survival (OS) of patients (p<0.05). According to the multivariate analysis of variance, the PFS of gastric cancer patients was associated with nerve invasion, lymph node metastasis, and hsa_circ_0006156 expression (relative risk coefficient=1.742, 2.329, and 3.003). Meanwhile, the OS was associated with lymph node metastasis, nerve invasion, degree of tumor differentiation, and hsa_circ_0006156 expression (relative risk coefficient =1.604, 2.405, 2.114, and 2.004). Moreover, the survival analysis revealed that PFS was markedly prolonged in the hsa_circ_0006156 high expression group compared with that in the hsa_circ_0006156 low expression group.
Conclusions: The expression of hsa_circ_0006156 substantially declines in gastric cancer tissues, which is related to the differentiation degree, presence, or absence of lymph node metastasis and prognosis of gastric cancer patients. Therefore, hsa_circ_0006156 may clinically serve as a biomarker for the prognostic prediction of gastric cancer patients.