Spinal diseases, including intervertebral disc degeneration (IDD), ankylosing spondylitis, spinal cord injury and other non‑infectious spinal diseases, severely affect the quality of life of patients. Current treatments for IDD and other spinal diseases can only relieve symptoms and do not completely cure the disease. Therefore, there is an urgent need to explore the causes of these diseases and develop new treatment approaches. Long non‑coding RNA (lncRNA), a form of non‑coding RNA, is abundant in diverse sources, has numerous functions, and plays an important role in the occurrence and development of spinal diseases such as IDD. However, the mechanism of action of lncRNAs has not been fully elucidated, and significant challenges remain in the use of lncRNAs as new therapeutic targets. The present article reviews the sources, classification and functions of lncRNAs, and introduces the role of lncRNAs in spinal diseases, such as IDD, and their therapeutic potential.

Cervical cancer (CC) constitutes a serious public health problem. Vaccination and screening programs have notably reduced the incidence of CC worldwide by >80%; however, the mortality rate in low‑income countries remains high. The staging of CC is a determining factor in therapeutic strategies: The clinical management of early stages of CC includes surgery and/or radiotherapy, whereas radiotherapy and/or concurrent chemotherapy are the recommended therapeutic strategies for locally advanced CC. The histopathological characteristics of tumors can effectively serve as prognostic markers of radiotherapy response; however, the efficacy rate of radiotherapy may significantly differ among cancer patients. Failure of radiotherapy is commonly associated with a higher risk of recurrence, persistence and metastasis; therefore, radioresistance remains the most important and unresolved clinical problem. This condition highlights the importance of precision medicine in searching for possible predictive biomarkers to timely identify patients at risk of treatment response failure and provide tailored therapeutic strategies according to genetic and epigenetic characteristics. The present review aimed to summarize the evidence that supports the role of several proteins, methylation markers and non‑coding RNAs as potential predictive biomarkers for CC.

Circular RNAs (circRNAs) are non‑coding single‑stranded covalently closed RNA molecules that are considered important as regulators of gene expression at the transcriptional and post‑transcriptional levels. These molecules have been implicated in the initiation and progression of multiple human diseases, ranging from cancer to inflammatory and metabolic diseases, including diabetes mellitus and its vascular complications. The present article aimed to review the current knowledge on the biogenesis and functions of circRNAs, as well as their role in cell processes associated with diabetic nephropathy. In addition, novel potential interactions between circRNAs expressed in renal cells exposed to high‑glucose concentrations and the transcription factors c‑Jun and c‑Fos are reported.

Diabetic retinopathy (DR) is a microvascular complication of diabetes. The retinal pigment epithelium (RPE) forms the outer layer of the blood‑retinal barrier and serves a role in maintaining retinal function. RPE cell injury has been revealed in diabetic animal models, and high glucose (HG) levels may cause damage to RPE cells by increasing the levels of oxidative stress, promoting pro‑inflammatory gene expression, disrupting cell proliferation, inducing the endothelial‑mesenchymal transition, weakening tight conjunctions and elevating cell death mechanisms, such as apoptosis, ferroptosis and pyroptosis. Non‑coding RNAs including microRNAs, long non‑coding RNAs and circular RNAs participate in RPE cell damage caused by HG levels, which may provide targeted therapeutic strategies for the treatment of DR. Plant extracts such as citrusin and hesperidin, and a number of hypoglycemic drugs, such as sodium‑glucose co‑transporter 2 inhibitors, metformin and glucagon‑like peptide‑1 receptor agonists, exhibit potential RPE protective effects; however, the detailed mechanisms behind these effects remain to be fully elucidated. An in‑depth understanding of the contribution of the RPE to DR may provide novel perspectives and therapeutic targets for DR.

Head and neck squamous cell carcinoma (HNSCC) is one of the most widespread malignancies worldwide. p53, as a transcription factor, can play its role in tumor suppression by activating the expression of numerous target genes. However, p53 is one of the most commonly mutated genes, which frequently harbors missense mutations. These missense mutations are nucleotide substitutions that result in the substitution of an amino acid in the DNA binding domain. Most p53 mutations in HNSCC are missense mutations and the mutation rate of p53 reaches 65‑85%. p53 mutation not only inhibits the tumor suppressive function of p53 but also provides novel functions to facilitate tumor recurrence, called gain‑of‑function (GOF). The present study focused on the prevalence and clinical relevance of p53 mutations in HNSCC, and further described how mutant p53 accumulates. Moreover, mutant p53 in HNSCC can interact with proteins, RNA, and exosomes to exert effects on proliferation, migration, invasion, immunosuppression, and metabolism. Finally, several treatment strategies have been proposed to abolish the tumor‑promoting function of mutant p53; these strategies include reactivation of mutant p53 into wild‑type p53, induction of mutant p53 degradation, enhancement of the synthetic lethality of mutant p53, and treatment with immunotherapy. Due to the high frequency of p53 mutations in HNSCC, a further understanding of the mechanism of mutant p53 may provide potential applications for targeted therapy in patients with HNSCC.

The term autophagy describes a process that supports nutrient cycling and metabolic adaptation that is accomplished via multistep lysosomal degradation. These activities modulate cell, tissue and internal environment stability, and can also affect the occurrence and development of cancer. Previous studies have mostly described autophagy as having dual effects in cancer, serving to limit tumorigenesis in the early stages of cancer, but promoting tumor progression in certain types of cancer. There have been indications in recent years that microRNAs (miRNAs/miRs) and long non‑coding RNAs (lncRNAs), as types of non‑coding RNAs, play major roles in the occurrence, invasion, development and drug resistance of hepatocellular carcinoma (HCC) and in the migration of HCC cells by governing HCC cell autophagy. Therefore, understanding which miRNAs and lncRNAs play such roles and the relevant molecular mechanisms is critical. The present review highlights the significant functions of miRNAs and lncRNAs in the regulation of autophagy in HCC and the relevant mechanisms, aiming to provide novel insight into HCC therapeutics.

Over the past few decades, research at the molecular level has focused on the part of the genome that does not encode protein sequences. Since the discovery of transcriptional evidence from the hitherto considered \'junk\' DNA, this region of the genome, which is currently termed dark DNA, is constantly gaining interest. The term borrows an analogy from the corresponding eminent fields of dark matter and dark energy in physics and cosmology. In fact, an increasing number of attempts are being made to enhance the current understanding of the non‑coding RNA (ncRNA) transcripts produced by such regions. Although the base‑pair length and gene number appear to be very diverse between species, it appears that the amount of the non‑coding regions of the genome of an organism is a sign of evolutional superiority. ncRNA molecules are able to orchestrate the expression of genetic information in the most complex, rapid and reversible manner, participating in almost every major biological process. A prime example of such a process is the maintenance of homeostasis, the internal physiological balance, despite internal and external stressful stimuli. These molecules have been shown to be excellent regulators of gene expression, with marked spatiotemporal specificity, rendering them ideal tools for regulating stress responses. Herein, an attempt is made to extract and fuse information from a repertoire of studies, which have demonstrated that the expression of a number of these molecules was modified following exposure to acute and chronic stress, as well as in patients with anxiety disorders and their respective animal models. All in all, ncRNAs have the potential to be used either as biomarkers or as therapeutic targets for disorders resulting from the loss of equilibrium, the disruption of homeostasis and the destabilization of the hypothalamic‑pituitary‑adrenal axis.

Alzheimer\'s disease (AD) is a neurodegenerative disorder that has a significant association with age. Despite its increasing incidence in the population, the etiology of the disease remains poorly understood, and there are currently no effective treatments readily available. The main genes that are associated with AD are the amyloid precursor protein, presenilin‑1 and presenilin‑2, as well as the apolipoprotein E gene. In addition to genetic factors, a wide range of environmental and lifestyle factors are equally characterized as risk factors for the development of AD, while non‑coding RNAs (ncRNAs) and other epigenetic mechanisms play a key role in their detrimental effects. Multiple types of ncRNAs, such as microRNAs, circular RNAs, Piwi‑interacting RNAs and long non‑coding RNAs are being increasingly implicated in AD. Alterations in ncRNAs can be detected in cerebrospinal fluid, as well in as the brain, highlighting these as promising biomarkers for the detection and treatment of AD. Developments in high‑throughput technologies have led to the so‑called \'omics\' era, which involves the collection of big data and information at both molecular and protein levels, while combining the development of novel computational and statistical tools capable of analyzing and filtering such data. The present review discusses the role of ncRNAs and their use as biomarkers for AD, and summarizes the findings from the application of omics technologies in AD.

RNA modifications have recently become the focus of attention due to their extensive regulatory effects in a vast array of cellular networks and signaling pathways. Just as epigenetics is responsible for the imprinting of environmental conditions on a genetic level, epitranscriptomics follows the same principle at the RNA level, but in a more dynamic and sensitive manner. Nevertheless, its impact in the field of cardiovascular disease (CVD) remains largely unexplored. CVD and its associated pathologies remain the leading cause of death in Western populations due to the limited regenerative capacity of the heart. As such, maintenance of cardiac homeostasis is paramount for its physiological function and its capacity to respond to environmental stimuli. In this context, epitranscriptomic modifications offer a novel and promising therapeutic avenue, based on the fine‑tuning of regulatory cascades, necessary for cardiac function. This review aimed to provide an overview of the most recent findings of key epitranscriptomic modifications in both coding and non‑coding RNAs. Additionally, the methods used for their detection and important associations with genetic variations in the context of CVD were summarized. Current knowledge on cardiac epitranscriptomics, albeit limited still, indicates that the impact of epitranscriptomic editing in the heart, in both physiological and pathological conditions, holds untapped potential for the development of novel targeted therapeutic approaches in a dynamic manner.

Osteosarcoma (OS) is the most common primary bone tumor worldwide. OS exhibits a range of aggressive behaviors, including early metastasis potential, rapid progression, poor clinical prognosis and insensitivity to chemoradiotherapy. Non‑coding RNAs are transcripts that do not encode proteins. A significant number of studies published on OS have been focused on the aberrant expression of non‑coding RNAs and their involvement in tumor initiation and progression. It has been confirmed that non‑coding RNAs exert their regulatory functions at both the transcriptional and post‑transcriptional level, which leads to tumor initiation or progression in OS. According to present knowledge, this review provides a state‑of‑the‑art overview of the functions and mechanisms of microRNAs, long non‑coding RNAs and circular RNAs in terms of their involvement with OS. The review also covers their potential clinical application in the diagnosis, prognosis and treatment of OS. It is hoped that the information presented in this review on the involvement of non‑coding RNAs in OS will lead to a more comprehensive understanding of OS and provide a useful perspective on the potential diagnostic and therapeutic applications of non‑coding RNAs for patients with OS.