Association between hsa_circ_0006156 expression and incidence of gastric cancer

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.

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.

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.

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.