Long non-coding RNA NEAT1 cannot be used as a diagnostic and prognostic biomarker in patients with locally advanced rectal cancer

Abstract

Background & objectives: The NEAT1 (Nuclear Paraspeckle Assembly Transcript 1) gene encodes a long non-coding RNA that is deregulated in carcinomas of the gastrointestinal tract. Diagnostic and predictive potential of NEAT1 was investigated in patients with locally advanced rectal cancer. Methods: The study group consisted of 19 patients with rectal cancer treated with neoadjuvant chemoradiotherapy (nCRT). RNA was isolated with TRIzol reagent from samples of rectal cancer and noncancerous tissue before and after nCRT. The relative expression level of NEAT1 normalised to GAPDH was determined by qRT-PCR method. Results: Expression of NEAT1 did not difer between rectal cancer and noncancerous tissue before nCRT (p=0.953) and cancer and noncancerous tissue after nCRT (p=0.210). There was no diference in NEAT1 expression between tumour tissue before and after nCRT (p=0.079). NEAT1 was signifcantly higher in noncancerous tissue before than after nCRT (p=0.005). Therapy responders (TRG1, TRG2) and nonresponders (TRG3, TRG4) did not difer in NEAT1 levels in tumour tissue before (p=0.790) and after nCRT (p=0.352). NEAT1 expression in rectal cancer tissue before nCRT cannot be used as a biomarker to distinguish responders from non-responders (AUC=0.559, 95%CI=0- 1, p=0.790). Demographic and clinicopathological characteristics were not associated with NEAT1 expression in rectal cancer tissue. Conclusion: The obtained results suggest that the long noncoding RNA NEAT1 cannot be considered as a biomarker with diagnostic potential or for predicting response to nCRT in patients with rectal cancer. Validation of the current results in a larger group of patients with locally advanced rectal cancer is warranted.