Pseudouridine (PU) is also called 5-ribosyluracil. Pseudouridine is a modified nucleoside and is an isomer of uridine. The connection method is that the 5-position carbon atom (C-5) on the heterocyclic ring of uracil is connected to the 1-position carbon atom (C-1) on the sugar ring of the pentose. It mainly exists in RNA, especially tRNA. Under the action of nucleoside phosphorylase, uracil and ribose produce uracil nucleoside, and then produce uracil nucleotide through phosphokinase. Pseudouridine synthase converts uridine at certain positions in the tRNA molecular chain into pseudouridine. Pseudouridine is the final product of tRNA degradation. When tRNA is degraded, pseudouridine can no longer be reused and is excreted in the urine as a complete molecule. Studies have shown that patients with malignant tumors such as thyroid cancer, nasopharyngeal cancer, lung cancer, breast cancer, liver cancer, gastric cancer, esophageal cancer, and lymphocytic leukemia often have a large amount of modified nucleosides, especially pseudouridine, in blood and urine. Therefore, pseudouridine can be used as a tumor marker for the diagnosis, condition and efficacy monitoring and prognosis judgment of a variety of malignant diseases.
Detection methods of pseudonucleosides
Methods for the determination of pseudouridine include immunoassay, fluorescence analysis, gas chromatography and high performance liquid chromatography. The advantage of gas chromatography for the detection of pseudouridine is that it is sensitive and rapid, but all operations must be fixed, otherwise the results will vary greatly and the equipment will be more expensive. The fluorescence analysis method has strong selectivity and sensitivity, but there are many interference factors. The immunoassay method uses specific antibodies to quantitatively analyze pseudouridine in blood and urine. This method does not require special pretreatment of samples, making the determination of pseudouridine more convenient, specific and sensitive, but the required specific antibodies are not easy to prepare, and there is a certain cross-reaction between uridine and pseudouridine serum. The high performance liquid chromatography method for the determination of pseudouridine has the advantages of sensitivity, accuracy, speed, and small sample consumption, so it has become the most commonly used method for the detection of pseudouridine.
The clinical significance of pseudouridine detection
Pseudouridine is used as a tumor marker for early diagnosis, differential diagnosis, monitoring of tumor progression and recurrence, judgment of curative effect and prognosis, and has good application value.
Prostate cancer (PCa) is a major public health problem in western developed countries. It is estimated that 11.2% of men will be diagnosed with PCa in their lifetime. Currently, serum prostate-specific antigen (PSA) is routinely used to detect and screen PCa, but the success rate of these measures is less than 15%. Therefore, it is very important to find accurate and novel tumor markers to detect PCa. Researchers investigated the potential predictive value of pseudouridine in detecting the progression of prostate cancer to advanced disease, and hypothesized that it could be used as a biomarker. The results of the study indicate that elevated levels of pseudouridine are found in prostate cancer, which has the potential to be a biomarker of prostate cancer progression.
The concentration of pseudouridine in serum and urine of patients with primary liver cancer is significantly higher than that of benign liver lesions, cirrhosis and normal people. The most commonly used tumor marker AFP has a poor correlation with pseudouridine. Therefore, pseudouridine is a potential diagnostic marker for primary liver cancer, and its combined application with AFP can increase the positive diagnosis rate of primary liver cancer.
The concentration of pseudouridine in blood and urine of patients with bladder cancer, breast cancer, esophageal cancer, lung cancer, thyroid cancer, gastric cancer, colorectal cancer and lymphocytic leukemia is significantly higher than that of normal people, and it is statistically significant. It is a tumor diagnosis Has application value.
The concentration of pseudouridine in serum gradually increases with the occurrence and development of tumors. Regularly measuring the concentration of pseudouridine in serum can detect tumor recurrence or recurrence earlier, and can judge the treatment response and prognosis of the tumor. The degree of elevated serum and urine pseudouridine concentrations in patients with gastric cancer and colorectal cancer may be related to the stage of the disease. The greater the degree of elevation, the worse the tumor differentiation and lymph node metastasis.
In short, pseudouridine as a tumor marker has certain value in the diagnosis, differential diagnosis, monitoring of occurrence and development, curative effect and prognosis of various malignant tumors. Detecting the concentration of pseudouridine in serum, urine, and tumor tissues, combined with some corresponding tumor markers such as AFP, can significantly improve the diagnosis rate of tumors, especially the early diagnosis rate. As researchers continue to study pseudouridine, they can further understand tumors and provide a basis for tumor diagnosis and treatment.