Progress of Circular RNAs in Different Types of Human Cancer

CircRNAs are remarkably stable and known to have diverse biological functions, such as microRNA sponging, regulation of transcription and splicing, and occasionally serving as templates for polypeptide production. CircRNAs exhibit tissue-specific expression and have been reported to be associated with the progression of various malignancies. Based on recent advances in genome sequencing and bioinformatics techniques, a rapid increase in the biological roles of circRNAs has been observed.

The biological function of circRNA has recently aroused great interest in the scientific community, and the scientific community is very curious about its study. Therefore, by understanding the functions of circRNAs, more therapeutic approaches are being developed, and with the advancement of science and technology, their specific roles in diseases are revealed. circRNAs are non-coding RNAs present in the genome and have diverse functions in regulating various molecules (such as mRNA, DNA, non-coding RNAs, and proteins) to regulate cellular functions and physiology of organisms.

During tumor development, circRNAs play a crucial role in enhancing the effectiveness and sensitivity of chemotherapy and radiotherapy. Multiple studies have shown that certain circRNAs are aberrantly expressed in tumor cells, but do not always promote malignancy; however, it is involved in the regulation of tumorigenesis. Many tumors, especially those originating in the gastrointestinal tract and ovary, are more prone to metastasize to the peritoneal cavity. In the intraperitoneal region between normally resident peritoneal cells and actively invasive cancer cells, a balance mediates the spread of malignancy. Many genes generate stable and conserved closed circRNAs with high potential for gene regulation. This knowledge could lead to targeting specific circRNAs to treat different types of cancer. In the pathogenesis of human cancers such as lung cancer, liver cancer, ovarian cancer, breast cancer, and prostate cancer, including tumors and malignant tumors of the central nervous system, circRNAs have been found to play a vital role in the development of cancer.

In addition to cancer, circRNAs are also associated with various human diseases. Researchers are trying to explore the basic molecular mechanisms behind the overexpression or knockdown process of specific circRNAs and their effects on cell cycle progression and regulation of different important proteins. Detecting cancer at its initial stage remains a challenge in the fight against cancer. The lack of reliable biomarkers has been an obstacle to this endeavor. Early diagnosis and early treatment of cancer can save patients' lives. Therefore, the advancement of next-generation biomarkers is an urgent prerequisite to address this issue. Next-generation biomarkers can help detect disease very quickly and efficiently. To diagnose cancer at an early stage, scientists are trying to develop next-generation biomarkers. Specifically, circRNAs are emerging as reliable biomarkers for detecting different types of cancer.

In the early days of research, circRNAs were thought to be mistakes in the RNA splicing process. With the progress of research in the field of bioinformatics, several endogenous circRNAs have been gradually discovered and identified, and the mystery of circRNAs has been revealed with the help of RNA-seq methods, but more research is needed to find out the specific mechanism behind circRNA biosynthesis. mechanism and its important role in cancer pathogenesis.

CircRNAs have a potential role in influencing treatment choices, as they may favor cancer resistance to chemotherapy. In various cancers that are resistant to certain drugs, the expression of certain circRNAs has a regulatory effect on cancer drug resistance. However, advanced research is needed for their site-specific delivery and understanding the full mechanism of regulation of tumor biology. CircRNA appears to be a promising structural element that can serve as an effective biomarker for cancer as well as a potential and valuable therapeutic target for cancer therapy.