Association between the expression level of miRNA‑374a and TGF‑β1 in patients with colorectal cancer

Colorectal cancer (CRC) poses a significant threat to global health with increasing incidence and mortality rates. Exploring different molecular mechanisms and aspects underlying the development and progression of CRC will promote the early diagnosis and lead to better outcomes. MicroRNAs (miRNAs/miRs) are one of the molecular aspects related to the development and diagnosis of CRC. The present study aimed to investigate the association between the expression levels of miRNA‑374a and transforming growth factor (TGF)‑β1 in patients with CRC to explore the roles of these markers in carcinogenesis and their use as diagnostic biomarkers. For this purpose, 195 subjects were enrolled. The expression level of miRNA‑374a was assessed in serum samples of 145 subjects (screening phase) in addition to 50 CRC tissue samples to validate the tumor‑derived expression of miRNA‑374a (confirmation phase). The analysis of miRNA‑374a expression was performed by the extraction of miRNAs followed by reverse transcription‑quantitative PCR. Additionally, the TGF‑β1 level was measured in all patients with CRC and control serum samples. ROC curve analysis was performed to determine the diagnostic potential of miRNA‑374a and TGF‑β1. The patients with CRC exhibited significantly elevated levels of miRNA‑374a compared with the healthy individuals, with a fold change of 12.92 (P=0.0001). Moreover, the expression of miRNA‑374a varied, depending on the CRC grade; patients with grade I disease exhibited a 9.2‑fold increase and those with grade II disease a 21.84‑fold increase in miRNA‑374a expression. The relative expression level of miRNA‑374a in CRC tissues was significantly upregulated by 4.48‑fold compared with the adjacent non‑cancerous tissues (P<0.001). Furthermore, the TGF‑β1 expression level was significantly elevated in patients with CRC compared with the controls (P=0.0001). The area under the curve was 0.9560 for CRC serum samples (P<0.0001), 0.8972 for CRC tissue (P<0.0001) and 0.8075 for TGF‑β1 expression levels (P=0.001). In addition, a positive correlation was found between the miRNA‑374 expression level and TGF‑β1 serum levels (Rho=0.8912, P=<0.0001). On the whole, the present study demonstrates that the elevated expression levels of miRNA‑374 and TGF‑β1 in patients with CRC indicate their crucial roles in driving tumor progression and highlight their potential for use diagnostic biomarkers and therapeutic targets in CRC.