Noncoding RNAs and Liquid Biopsy in Lung Cancer: A Literature Review

Abstract

Lung cancer represents a genetically heterogeneous disease with low survival rates. Recent data have evidenced key roles of noncoding RNAs in lung cancer initiation and progression. These functional RNA molecules that can act as both oncogenes and tumor suppressors may become future biomarkers and more efficient therapeutic targets. In the precision medicine era, circulating nucleic acids have the potential to reshape the management and prognosis of cancer patients. Detecting genomic alterations and level variations of circulating nucleic acids in liquid biopsy samples represents a noninvasive method for portraying tumor burden. Research is currently trying to validate the potential role of liquid biopsy in lung cancer screening, prognosis, monitoring of disease progression, and treatment response. However, this method requires complex detection assays, and implementation of plasma genotyping in clinical practice continues to be hindered by discrepancies that arise when compared to tissue genotyping. Understanding the genomic landscape of lung cancer is essential in order to provide useful and innovative research in the age of patient-tailored therapy. In this landscape, the noncoding RNAs play a crucial role due to their target genes that dramatically influence the tumor microenvironment and the response to therapy. This article addresses present and future possible roles of liquid biopsy in lung cancer. It also discusses how the complex role of noncoding RNAs in lung tumorigenesis could influence the management of this pathology.

Cryobiopsy in Lung Cancer Diagnosis—A Literature Review

“…EGFR is one of the most relevant genetic alteration in NSCLC, as it is targeted by tyrosine kinase inhibitors with a better side effect profile and an improved progression free survival as compared to standard chemotherapy [ 41 ]. Therefore, in order to have a precise molecular characterization of the lung tumor, adequate quantity and quality tissue samples are needed [ 42 ]. Haentschel et al [ 43 ] attempted to evaluate the detection rate of EGFR alterations in cryobiopsy samples in comparison to samples obtained by other biopsy techniques (forceps biopsy, fine needle aspiration) in NSCLC patients.…”

Liquid Biopsy for Cancer Cachexia: Focus on Muscle-Derived microRNAs

“…The scientific community's growing interest in liquid biopsy depends on the possibility to obtain relevant information on the tumor and to learn about its molecular dynamic changes with minimally invasive methods, less dangerous and less expensive compared to surgical biopsies [39][40][41][42][43][44][45]. Indeed, although giving direct information, tissue biopsies have some disadvantages such as lack of indications regarding the spatial and temporal heterogeneity of the tumor [46], limited accessibility to the tumor tissue which could increase the possibility of false negative results [46], and bleeding or infections as a consequence of an invasive biopsy or excisional procedure [47].…”

“…In the present review we focused our attention on circulating, muscle-produced miRNAs detection through liquid biopsy as an alternative to invasive skeletal muscle solid biopsy. The reason for this is that miRNAs have many features in common with an ideal biomarker, among which they are stable in body fluids since they are resistant to RNAse digestion, to extreme pH, as well as to high temperatures and to repeated freeze-thaw cycles [32,41,[74][75][76]. In addition, they are easily accessible through the repeatable and less invasive liquid biopsy method compared to the anatomical and clinical difficulties that can be encountered in performing a surgical biopsy [29,51].…”

“…In physiological conditions, muscular and circulating muscular miRNAs maintain skeletal muscle homeostasis and are expressed at low concentrations in biological fluids [163], while their up-or down-regulation has been observed in several diseases [41,[200][201][202][203]. While promising results have been achieved by using experimental cachexia models, results on miRNAs obtained in humans are controversial and need more effort to become definitive due mainly to the higher variability of cachectic patients.…”

“…To date, quantitative Real-Time PCR is the "gold standard" for miRNA analysis [147], however, there are several kits (also very different from each other) available to perform retro-transcription (RT) and Real-Time PCR steps. Standardized methods for collecting biological fluids, for RNA extraction and for the RNA quantification would make possible the comparison of data obtained by different researchers [41,51,207,210].…”