RESUMO
Colorectal cancer (CRC) is linked to high mortality, mainly when discovered in its advanced stages. Several studies have pointed to the role of epigenetic factors in CRC and other cancers. Long non-coding RNAs (lncRNAs) are involved in the initiation, progression, metastasis, and modulation of the response to chemotherapeutic modalities of CRC as vital contributors to epigenetic mechanisms. Colon cancer-associated transcript-1 (CCAT1) is one of the lncRNAs that have been dysregulated in serum samples, providing a non-invasive route for diagnosing CRC patients. This study aimed to determine the role of CCAT1 expression as diagnostic and prognostic markers. We tested the associations of CCAT1 expression with serum carcinoembryonic antigen (CEA) and carbohydrate antigen 19-9 (CA 19-9). The study included three groups: 41 patients with colorectal cancer, 39 patients with precancerous benign colorectal diseases, and 20 normal control individuals. CEA and CA 19-9 were measured by an immunoassay automated system. The expression level of CCAT1 was assessed by a real-time polymerase chain reaction. There was a statistically significant elevation of serum CEA levels in patients with CRC compared to patients with precancerous benign colorectal diseases. Furthermore, there was no statistically significant difference in serum CA 19-9 levels between all groups (p = 0.102). Interestingly, CCAT1 expression was significantly upregulated in the blood of CRC patients compared to the precancerous benign colorectal diseases group (p = 0.009) and the control group (p <0.001). Also, expression of CCAT1 was significantly elevated in patients with precancerous benign colorectal diseases compared to the control group (p=0.004). In conclusion, measuring the expression level of CCAT1 is more advised than assessment of CEA and CA 19-9 for the early diagnosis and prognosis of colorectal cancer.