Expression levels of microRNA-375 in pancreatic cancer

Abstract

MicroRNAs (miRNAs) are small, non-coding RNAs of endogenous origin that have been increasingly shown to have altered expressions in various cancer types. The expression levels of miR-375 have not been comprehensively investigated in pancreatic cancer. In this study, total RNA was extracted from 44 pairs of pancreatic cancer tissues and non-tumor adjacent tissues, as well as from four pancreatic cancer cell lines, Panc-1, SW1990, BxpC3 and Patu8988. Following polyadenylation and reverse transcription, the expression levels of miR-375 were determined by real-time PCR and the difference in expression was calculated using the 2^-ΔΔCt method. The correlation between the expression levels of miR-375 and clinicopathological characteristics of pancreatic cancer was also assessed. miR-375 expression was frequently downregulated in the pancreatic cancer tissues compared to their non-tumor counterparts (P<0.05; paired t-test). Moreover, a significantly low expression of miR-375 was found in the pancreatic cancer cell lines (Panc-1, P=0.016; SW1990, P=0.016; BxPC3, P=0.018; Patu8988, P=0.017; paired t-test). However, no significant correlations were observed between the low expression of miR-375 and parameters including gender, age, tumor size, tumor location and histological grade (P>0.05). The low expression of miR-375 was correlated with pT stage, lymph node metastases and pTNM stage (P<0.05) (non-parametric test; Mann-Whitney U test between 2 groups and Kruskal-Wallis H test for ≥3 groups). In conclusion, miR-375 is potentially involved in the carcinogenesis of pancreatic cancers and serves as is a potential biomarker for pancreatic cancer.

Keywords: miR-375; microRNA; pancreatic cancer.

Figure 1

Quantification of miR-375 was measured by quantitative real-time reverse transcription-polymerase chain reaction. Each sample was analyzed in triplicate and repeated three times. Data are presented as the log2 of fold-change of pancreatic cancer tissues relative to matched adjacent non-tumor tissues.

Figure 2

miR-375 was differentially expressed between pancreatic cancer tissues (T) and matched non-tumor adjacent tissues (NT). miR-375 was significantly downregulated in pancreatic cancer tissues compared to the matching adjacent non-tumor tissues (P<0.05; t-test).

Figure 3

Expression levels of miR-375 in 3 pancreatic cancer cell lines (Panc-1, SW1990, BxPC3 and Patu8988). Quantification of miRNAs was measured by quantitative real-time reverse transcription-polymerase chain reaction. Data are presented in the pancreatic cancer cell lines relative to the normal pancreatic tissues. miR-375 was significantly downregulated in four pancreatic cancer cell lines compared to non-tumor adjacent tissues (NT) (^*P<0.05; t-test).