miRNA-Based Technologies in Cancer Therapy.

The discovery of therapeutic miRNAs is one of the most exciting challenges for pharmaceutical companies. Since the first miRNA was discovered in 1993, our knowledge of miRNA biology has grown considerably. Many studies have demonstrated that miRNA expression is dysregulated in many diseases, making them appealing tools for novel therapeutic approaches. This review aims to discuss miRNA biogenesis and function, as well as highlight strategies for delivering miRNA agents, presenting viral, non-viral, and exosomic delivery as therapeutic approaches for different cancer types. We also consider the therapeutic role of microRNA-mediated drug repurposing in cancer therapy.

New­onset neuropsychiatric sequelae and 'long­COVID' syndrome (Review).

The ongoing coronavirus disease 2019 (COVID-19) pandemic has had a widespread impact on individuals' mental health through indirect psychological and social mechanisms, related to factors such as fear of infection or death, social isolation, lack of social support and financial instability. The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection has also been associated with the development or recurrence of neuropsychiatric symptoms, both during the acute phase, as well as during the post-acute 'long-COVID' phase. In addition to the COVID-19 survivors with a mental health history that are at a high risk of experiencing a range of neuropsychiatric symptoms following resolution of acute COVID-19, there is accumulating evidence that a diagnosis of COVID-19 may also be associated with new-onset neuropsychiatric morbidity among survivors without pre-existing mental health disorders. In particular, studies investigating the incidence of post-acute neuropsychiatric sequelae, based mostly on retrospective cohort study designs and data from national health registries, have reported the development of new-onset manifestations, including depression, anxiety, psychotic symptoms, sleep disturbances and fatigue. Nevertheless, when COVID-19 survivors were compared with SARS-CoV-2-negative controls and especially survivors of other disorders (such as influenza), the findings regarding the risk of incident neuropsychiatric manifestations varied among studies. While there is evidence of an association between SARS-CoV-2 infection and the subsequent occurrence of new-onset neuropsychiatric symptoms, especially among patients with increased disease severity, further research using methodological approaches less susceptible to confounding bias is required to establish causal relationships.

T-Cell Repertoire in Tumor Radiation: The Emerging Frontier as a Radiotherapy Biomarker.

Radiotherapy (RT) is a therapeutic modality that aims to eliminate malignant cells through the induction of DNA damage in the irradiated tumor site. In addition to its cytotoxic properties, RT also induces mechanisms that result in the promotion of antitumor immunity both locally within the irradiation field but also at distant tumor lesions, a phenomenon that is known as the "abscopal" effect. Because the immune system is capable of sensing the effects of RT, several treatment protocols have been assessing the synergistic role of radiotherapy combined with immunotherapy, collectively referred to as radioimmunotherapy. Herein, we discuss mechanistic insights underlying RT-based immunomodulation, which also enhance our understanding of how RT regulates antitumor T-cell-mediated immunity. Such knowledge is essential for the discovery of predictive biomarkers and for the improvement of clinical trials investigating the efficacy of radio-immunotherapeutic modalities in cancer patients.

Long COVID and neuropsychiatric manifestations (Review).

There is accumulating evidence in the literature indicating that a number of patients with coronavirus disease 2019 (COVID-19) may experience a range of neuropsychiatric symptoms, persisting or even presenting following the resolution of acute COVID-19. Among the neuropsychiatric manifestations more frequently associated with 'long COVID' are depression, anxiety, post-traumatic stress disorder, sleep disturbances, fatigue and cognitive deficits, that can potentially be debilitating and negatively affect patients' wellbeing, albeit in the majority of cases symptoms tend to improve over time. Despite variations in results obtained from studies using different methodological approaches to define 'long COVID' syndrome, the most widely accepted factors associated with a higher risk of developing neuropsychiatric manifestations include the severity of foregoing COVID-19, the female sex, the presence of comorbidities, a history of mental health disease and an elevation in the levels of inflammatory markers, albeit further research is required to establish causal associations. To date, the pathophysiological mechanisms implicated in neuropsychiatric manifestations of 'long COVID' remain only partially elucidated, while the role of the indirect effects of the COVID-19 pandemic, such as social isolation and uncertainty concerning social, financial and health recovery post-COVID, have also been highlighted. Given the alarming effects of 'long-COVID', interdisciplinary cooperation for the early identification of patients who are at a high risk of persistent neuropsychiatric presentations, beyond COVID-19 recovery, is crucial to ensure that appropriate integrated physical and mental health support is provided, with the aim of mitigating the risks of long-term disability at a societal and individual level.

The impact of radiation therapy on the TCR Vß chain repertoire in patients with prostate cancer.

Radiation therapy (RT) is an essential component in the therapeutic treatment of patients with localized prostate cancer (LPCa). Besides its local effects, ionizing radiation has been linked to mechanisms leading to systemic immune activation. The present study explored the effect of RT on the T­cell receptor variable ß (TCR Vß) chain repertoire of peripheral blood T cells in patients with LPCa. High­throughput TCR Vß sequencing was performed on 20 blood samples collected from patients with LPCa at baseline and 3 months post­RT. The diversity index was altered, as were TCR Vß clonal evenness and convergence before and post­RT; however, these findings were not significant. Notably, marked changes in the frequencies among the top 10 TCR Vß clonotypes were detected and some patients developed new clonotypes of high abundance. These data provided initial evidence that RT in patients with LPCa may induce systemic immune changes, which could be exploited by future therapies for improved clinical results.

Suicidality and COVID-19: Suicidal ideation, suicidal behaviors and completed suicides amidst the COVID-19 pandemic (Review).

Since the outbreak of the coronavirus 2019 (COVID-19) pandemic, there has been widespread concern that social isolation, financial stress, depression, limited or variable access to health care services and other pandemic-related stressors may contribute to an increase in suicidal behaviors. In patients who have recovered from COVID-19, an increased risk of developing suicidal behaviors may be noted, while post-COVID syndrome comprises another potential risk factor contributing to increased suicidal behaviors. Despite the initial alarming predictions for an increase in suicide rates due to the COVID-19 pandemic, the majority of published studies to date suggest that experienced difficulties and distress do not inevitably translate into an increased number of suicide-related deaths, at least not in the short-term. Nevertheless, the long-term mental health effects of the COVID-19 pandemic have yet to be unfolded and are likely to remain for a long period of time. Suicide prevention and measures aiming at promoting well-being and mitigating the effects of COVID-19 on mental health, particularly among vulnerable groups, should thus be a priority for healthcare professionals and policymakers amidst the evolving COVID-19 pandemic.

COVID-19 and post-traumatic stress disorder: The perfect 'storm' for mental health (Review).

Since its outbreak, in December, 2019, in the Chinese city of Wuhan, coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has evolved into an ongoing global pandemic. Due to the novel antigenic properties of this virus, the world population could not develop immunity effectively and this led to the subsequent spread of COVID-19. This caused an unprecedented emergency situation with significant negative effects on health and well-being both on an individual and societal level. Apart from health, economic and social consequences, the impact of this pandemic on mental health is increasingly being reported in the scientific literature. The present review aimed to provide a comprehensive discussion of the possible neurological and neuropsychiatric manifestations of SARS-CoV-2, together with the related underlying molecular pathways. In addition, the present review focused on populations which are at a higher risk of developing psychiatric disturbances due to the COVID-19 pandemic and discussed possible routes of clinical management and therapeutics to minimize the burden associated with psychiatric disorders. Moreover, research findings exploring the prevalence of COVID-19-related post-traumatic stress disorder (PTSD) symptoms across vulnerable groups, including children, adolescents and COVID-19 survivors are presented, with particular emphasis on those with severe disease who required hospitalization and/or intensive care unit admission. Based on the available literature, the identification of potential determinants associated with PTSD across the different populations is underlined. Lessons learnt from the pandemics across the globe together with the ongoing research on COVID-19 and its impact on mental health, highlight the utmost importance for evidence-based, proactive and targeted interventions in high-risk groups aiming to mitigate the risks and manage vulnerabilities.

Prostate Cancer Biomarkers: From diagnosis to prognosis and precision-guided therapeutics.

Prostate cancer (PCa) is one of the most commonly diagnosed malignancies and among the leading causes of cancer-related death worldwide. It is a highly heterogeneous disease, ranging from remarkably slow progression or inertia to highly aggressive and fatal disease. As therapeutic decision-making, clinical trial design and outcome highly depend on the appropriate stratification of patients to risk groups, it is imperative to differentiate between benign versus more aggressive states. The incorporation of clinically valuable prognostic and predictive biomarkers is also potentially amenable in this process, in the timely prevention of metastatic disease and in the decision for therapy selection. This review summarizes the progress that has so far been made in the identification of the genomic events that can be used for the classification, prediction and prognostication of PCa, and as major targets for clinical intervention. We include an extensive list of emerging biomarkers for which there is enough preclinical evidence to suggest that they may constitute crucial targets for achieving significant advances in the management of the disease. Finally, we highlight the main challenges that are associated with the identification of clinically significant PCa biomarkers and recommend possible ways to overcome such limitations.

Non-coding RNAs (miRNAs and lncRNAs) and their roles in lymphogenesis in all types of lymphomas and lymphoid malignancies.

Contemporary developments in molecular biology have been combined with discoveries on the analysis of the role of all non-coding RNAs (ncRNAs) in human diseases, particularly in cancer, by examining their roles in cells. Currently, included among these common types of cancer, are all the lymphomas and lymphoid malignancies, which represent a diverse group of neoplasms and malignant disorders. Initial data suggest that non-coding RNAs, particularly long ncRNAs (lncRNAs), play key roles in oncogenesis and that lncRNA-mediated biology is an important key pathway to cancer progression. Other non-coding RNAs, termed microRNAs (miRNAs or miRs), are very promising cancer molecular biomarkers. They can be detected in tissues, cell lines, biopsy material and all biological fluids, such as blood. With the number of well-characterized cancer-related lncRNAs and miRNAs increasing, the study of the roles of non-coding RNAs in cancer is bringing forth new hypotheses of the biology of cancerous cells. For the first time, to the best of our knowledge, the present review provides an up-to-date summary of the recent literature referring to all diagnosed ncRNAs that mediate the pathogenesis of all types of lymphomas and lymphoid malignancies.

Bromamine T, a stable active bromine compound, prevents the LPS­induced inflammatory response.

Inflammation is the most common cause of most acute and chronic debilitating diseases. Towards unveiling novel therapeutic options for patients with such complications, N­bromotaurine (TauNHBr) has emerged as a potential anti­inflammatory agent; however, its therapeutic efficacy is hindered due to its relatively poor stability. To address this challenge, the present study focused on examining the effects of a stable active bromine compound, named bromamine T (BAT). The present study examined the protective properties of BAT against lipopolysaccharide (LPS)­mediated inflammation in vitro, by using LPS­stimulated murine J774.A1 macrophages (Mφs), as well as in vivo, by using a murine LPS­mediated air­pouch model. Additionally, its efficacy was compared with that of taurine, a known potent anti­inflammatory molecule. In LPS­stimulated J774A.1 Mφs, BAT and taurine were very effective in reducing the secretion of pro­inflammatory mediators. The in vitro experiments indicated that LPS­mediated inflammation was attenuated due to the protective properties of BAT and of taurine, probably through the inhibition of phosphorylated p65 NF­κB subunit (Ser 536) nuclear translocation. The in vivo experiments also revealed that BAT and taurine inhibited LPS­mediated inflammation by reducing total cell/polymorphonuclear cell (PMN) infiltration in the air­pouch and by decreasing pouch wall thickness. The analysis of exudates obtained from pouches highlighted that the inhibitory effects of BAT and taurine on the secretion of pro­inflammatory cytokines were similar to those observed in vitro. Notably, the effect of BAT at the highest concentration tested was superior to that of taurine at the highest concentration. Taken together, the findings of the present study indicate that BAT prevents the LPS­induced inflammatory response both in vitro and in vivo.

Immunotherapy as a Precision Medicine Tool for the Treatment of Prostate Cancer.

Prostate cancer (PCa) is the most frequently diagnosed type of cancer among Caucasian males over the age of 60 and is characterized by remarkable heterogeneity and clinical behavior, ranging from decades of indolence to highly lethal disease. Despite the significant progress in PCa systemic therapy, therapeutic response is usually transient, and invasive disease is associated with high mortality rates. Immunotherapy has emerged as an efficacious and non-toxic treatment alternative that perfectly fits the rationale of precision medicine, as it aims to treat patients on the basis of patient-specific, immune-targeted molecular traits, so as to achieve the maximum clinical benefit. Antibodies acting as immune checkpoint inhibitors and vaccines entailing tumor-specific antigens seem to be the most promising immunotherapeutic strategies in offering a significant survival advantage. Even though patients with localized disease and favorable prognostic characteristics seem to be the ones that markedly benefit from such interventions, there is substantial evidence to suggest that the survival benefit may also be extended to patients with more advanced disease. The identification of biomarkers that can be immunologically targeted in patients with disease progression is potentially amenable in this process and in achieving significant advances in the decision for precision treatment of PCa.

[Comment] The COVID­19 pandemic as a scientific and social challenge in the 21st century.

The coronavirus disease­2019 (COVID­19) pandemic, caused by the new coronavirus SARS­CoV­2, has spread around the globe with unprecedented consequences for the health of millions of people. While the pandemic is still in progress, with new incidents being reported every day, the resilience of the global society is constantly being challenged. Under these circumstances, the future seems uncertain. SARS­CoV­2 coronavirus has spread panic among civilians and insecurity at all socio­political and economic levels, dramatically disrupting everyday life, global economy, international travel and trade. The disease has also been linked to the onset of depression in many individuals due to the extreme restriction measures that have been taken for the prevention of the rapid spreading of COVID­19. First, the socio­economic, political and psychological implications of the COVID­19 pandemic were explored. Substantial evidence is provided for the consequences of the pandemic on all aspects of everyday life, while at the same time we unravel the role and the pursuits of national regimes during this unforeseen situation. The second goal of this review is related to the scientific aspect of the pandemic. Hence, we explain why SARS­CoV­2 is not a so­called 'invisible enemy', and also attempt to give insight regarding the origin of the virus, in an effort to reject the conspiracy theories that have arisen during the pandemic. Finally, rational strategies were investigated for successful vaccine development. We are optimistic that this review will complement the knowledge of specialized scientists and inform non­specialized readers on basic scientific questions, and also on the social and economic implications of the COVID­19 pandemic.

Historical retrospective of the SRC oncogene and new perspectives (Review).

Since its first discovery as part of the Rous sarcoma virus (RSV) genome, the c-SRC (SRC) proto-oncogene has been proved a key regulator of cancer development and progression, and thus it has been highlighted as an attractive target for anti-cancer therapeutic strategies. Though the exact mechanisms of its action are still not fully understood, SRC protein mediates crucial normal cell functions, such as cell development, proliferation and survival, and its dysregulation is considered as an oncogenic signature and a driving force for cancer initiation. In the present review, we present a flashback to the history of the Src research, while focusing on the most important milestones in the field. Moreover, we investigate the proposed regulatory mechanisms and molecules that mediate its action in order to designate putative therapeutic targets and useful prognostic and/or diagnostic tools. Furthermore, we present and discuss existing therapeutic approaches that are explored in clinical settings.

Significance of taurine transporter (TauT) in homeostasis and its layers of regulation (Review).

Taurine (2­aminoethanesulfonic acid) contributes to homeostasis, mainly through its antioxidant and osmoregulatory properties. Taurine's influx and efflux are mainly mediated through the ubiquitous expression of the sodium/chloride­dependent taurine transporter, located on the plasma membrane. The significance of the taurine transporter has been shown in various organ malfunctions in taurine­transporter­null mice. The taurine transporter differentially responds to various cellular stimuli including ionic environment, electrochemical charge, and pH changes. The renal system has been used as a model to evaluate the factors that significantly determine the regulation of taurine transporter regulation.

Role of taurine, its haloamines and its lncRNA TUG1 in both inflammation and cancer progression. On the road to therapeutics? (Review).

For one century, taurine is considered as an end product of sulfur metabolism. In this review, we discuss the beneficial effect of taurine, its haloamines and taurine upregulated gene 1 (TUG1) long non­coding RNA (lncRNA) in both cancer and inflammation. We outline how taurine or its haloamines (N­Bromotaurine or N­Chlorotaurine) can induce robust and efficient responses against inflammatory diseases, providing insight into their molecular mechanisms. We also provide information about the use of taurine as a therapeutic approach to cancer. Taurine can be combined with other chemotherapeutic drugs, not only mediating durable responses in various malignancies, but also circumventing the limitations met from chemotherapeutic drugs, thus improving the therapeutic outcome. Interestingly, the lncRNA TUG1 is regarded as a promising therapeutic approach, which can overcome acquired resistance of cancer cells to selected strategies. In this regard, we can translate basic knowledge about taurine and its TUG1 lncRNA into potential therapeutic options directed against specific oncogenic signaling targets, thereby bridging the gap between bench and bedside.

Let-7, mir-98 and mir-183 as biomarkers for cancer and schizophrenia [corrected].

Recent evidence supports a role of microRNAs in cancer and psychiatric disorders such as schizophrenia and bipolar disorder, through their regulatory role on the expression of multiple genes. The rather rare co-morbidity of cancer and schizophrenia is an old hypothesis which needs further research on microRNAs as molecules that might exert their oncosuppressive or oncogenic activity in the context of their role in psychiatric disorders. The expression pattern of a variety of different microRNAs was investigated in patients (N = 6) suffering from schizophrenia termed control, patients with a solid tumor (N = 10) and patients with both schizophrenia and tumor (N = 8). miRNA profiling was performed on whole blood samples using the miRCURY LNA microRNA Array technology (6th & 7th generation). A subset of 3 microRNAs showed a statistically significant differential expression between the control and the study groups. Specifically, significant down-regulation of the let-7p-5p, miR-98-5p and of miR-183-5p in the study groups (tumor alone and tumorand schizophrenia) was observed (p<0.05). The results of the present study showed that let-7, miR-98 and miR-183 may play an important oncosuppressive role through their regulatory impact in gene expression irrespective of the presence of schizophrenia, although a larger sample size is required to validate these results. Nevertheless, further studies are warranted in order to highlight a possible role of these and other micro-RNAs in the molecular pathways of schizophrenia.