CircRNA_0109291 regulates cell growth and migration in oral squamous cell carcinoma and its clinical significance

Abstract

Objectives: Circular RNAs (circRNAs), a new class of non-coding RNAs, have emerged as important regulators during tumorigenesis. However, the functions of circRNAs have not been completely clarified in the progression of cancers. In our study, a novel circRNA hsa_circ_0109291 was investigated in oral squamous cell carcinoma (OSCC) tissues and cell lines.

Materials and methods: The expression profile of circRNAs in OSCC tumor tissues was performed by high-throughput sequencing. The CCK-8 wound healing and apoptosis assay were measured in OSCC cell lines after transfection with si-0109291 or si-NC.

Results: We discovered that hsa_circ_0109291 was significantly increased in OSCC tissues and cell lines compared with their corresponding control group. Knockdown of hsa_circ_0109291 inhibited proliferation and migration of OSCC cell lines in vitro. In addition, inhibition of hsa_circ_0109291 dramatically induced apoptosis of OSCC cells. We further found that high hsa_circ_0109291 levels in OSCC patients resulted in a poorer prognosis than in patients with low hsa_circ_0109291 levels.

Conclusion: These findings indicated that hsa_circ_0109291 correlated with the progression of OSCC and might be a new therapeutic target for the treatment of OSCC.

Keywords: Apoptosis; CircRNA; Hsa_circ_0109291; Oral squamous cell – carcinoma; Prognosis.

Figure 1

CircRNAs expression profile in oral squamous cell carcinoma tumor tissues. OSCC-related circRNAs were selected out based on FDR ≤ 0.001 and fold change ≥ 2 or fold change ≤ 0.5. 41 circRNAs were differentially expressed between OSCC tissues and normal tissues. The heat map showed the 41 differentially expressed circRNAs, red indicating high expression and green indicating low expression

Figure 2

Hsa_circ_0109291 expression was up-regulated in oral squamous cell carcinoma tumor tissues. Hsa_circ_0109291 expression was measured in 51 tumor tissues and matched adjacent non-tumorous tissues from OSCC patients, and the fold change was calculated (A and B). Hsa_circ_0109291 correlated to the advanced TNM stage (C). Kaplan-Meier survival curve was used to evaluate whether hsa_circ_0109291 expression levels were associated with overall survival in patients with OSCC (D). * P<0.05, *** P<0.001

Figure 3

Inhibition of hsa_circ_0109291 suppresses oral squamous cell carcinoma cell growth in vitro. Relative expression of hsa_circ_0109291 in NHOK cells and OSCC cell lines was measured by RT-qPCR (A). The efficiency of si-RNA to inhibit hsa_circ_0109291 expression was verified by RT-qPCR (B). The cell viability of SCC4 (C) and CAL27 (D) was measured by CCK-8 assay after transfection with si-0109291-1 and si-NC for 0-72 hr. * P<0.05, ** P<0.01 and *** P< 0.001

Figure 4

Inhibition of hsa_circ_0109291 suppresses oral squamous cell carcinoma cell migration in vitro. After transfection with si-0109291-1 and si-NC, SCC4 (A) and CAL27 (B) cell migration was determined by wound healing assay for 24 hr. * P<0.05

Figure 5

Inhibition of hsa_circ_0109291 induced oral squamous cell carcinoma cell apoptosis in vitro. After transfection with si-0109291-1 and si-NC, SCC4 (A) and CAL27 (B) cell apoptosis was detected by flowcytometry for 24 hr. * P<0.05

Figure 6

Inhibition of hsa_circ_0109291 regulated apoptosis-related protein expression. After transfection with si-0109291-1 and si-NC, protein expression of Bcl-2, Bax, and Cleaved-caspase3 was measured by Western blotting in SCC4 (A) and CAL27 (B) cells for 24 hr. * P< 0.05