گزینه های مناسب بیومارکر ریبونوکلئیک اسید برای تشخیص اولیه سرطان
Abstract
1- Introduction
2- Common lethal cancers
3- Investigating miRNA profiling in cancers
4- MiR candidates for early phase group detection
5- Conclusion
References
Abstract
Cancer is considered as a challenging lethal agent around the world and its detection at early stages would help prevention of the high mortality. Among the widely used biomarkers in clinical diagnosis of cancer, extracellular non-coding RNAs as ribonucleic acid biomarkers serve as state-of-the-art candidates for molecular diagnosis. In that regard, microRNAs are of great priority mainly because of high variety and stability in body fluids. Accordingly, common miRNAs among most prevalent cancers could help us (pre)diagnose cancer with high accuracy in target samples. In this study, common lethal cancers to humans were investigated in case of miRNA profiles to determine the possible common correlation between miRNA up-regulation or down-regulation (as a ribonucleic acid biomarker) and developing the cancers. It was shown that among the investigated miRNAs, five typical extracellular miRNAs (miR-18a, miR-21, miR-155, miR-221, and miR-375) dysregulation are predominant in most cancer varieties comprising breast, colon, lung, prostate, pancreas, gastric, ovarian, esophagus and liver. This could serve as an appropriate target site for developing point-of-care approaches for cancer detection e.g. designing diagnostic biosensor-based microarrays or kits for both quantification and qualification of the biomarkers. Besides, the miRNA candidates could be efficiently applied to cancer therapeutic approaches.
Introduction
Cancer keeps on being a remarkable cause of worldwide mortality in spite of many years of effort and cost. Deadliest types of cancers to human includes pancreas, liver, lung and bronchus, prostate/breast, colon, rectum and ovary [1–3]. Most of cancers do not induce clinical symptoms until in the later stages when the therapeutic treatment is no longer an option. However, detection of cancer at first stages, regardless of its origin, greatly increases the chance of effective treatments. In spite of much research in cancer biomarkers, only a few are considered for early diagnosis of common cancers. In addition, there is not a general biomarker for population screening in order to detect both asymptomatic cancers and early-staged cancers. Hence, investigating more sensitive and non-invasive biomarkers is still a promising challenge in cancer diagnosis and prognosis [4]. Accessing circulating cancer biomarkers through biological fluids using liquid biopsy seems to propose a promising cost-effective and non-invasive solution. Literally, cf-miRNAs are considered as ideal circulating cancer biomarkers due to their ease of access and quantification, besides integration with other macromolecules e.g. proteins, and high stability in plasma [5, 6]. MiRNAs are endogenous, small (18–24 nt), non-coding (nc) RNA molecules that play important regulatory roles in cell proliferation, apoptosis, metastasis and angiogenesis [7]. Dysregulated miRNA(s) have both oncogenic and tumor-suppressing effects depending on their corresponding targets. The increase or decrease of miRNAs is related to the role of their target genes in cancer progression or regression. MiRNAs are mainly categorized in two groups: 1) OncomiRs that are up-regulated in cancers to target protein-coding transcripts in tumor suppressive pathways, and consequently increase cell proliferation, invasion and metastasis. 2) Tumor-suppressor miRNAs that repress the oncogenic genes and their down-regulation in cancer increases the oncogenic activity [8]. MiRNAs show various expression patterns in tissue and blood of many cancers in comparison with normal samples. Furthermore, miRNA profiles in cancers with various tissue origins are distinct from each other [9].