Neuroblastoma (NB) is the most common extracranial solid malignancy in children. Despite current aggressive treatment regimens, the prognosis for high‐risk NB patients remains poor, with the survival of less than 40%. Amplification/stabilization of MYCN oncogene, in NB is associated with a high risk of recurrence. Thus, there is an urgent need for novel therapeutics. The deregulated expression of microRNA (miR) is reported in NB; nonetheless, its effect on MYCN regulation is poorly understood. First, we identified that miR‐15a‐5p, miR‐15b‐5p, and miR‐16‐5p (hereafter miR‐15a, miR‐15b or miR‐16) were down‐regulated in patient‐derived xenografts (PDX) with high MYCN expression. MiR targeting sequences on MYCN mRNA were predicted using online databases such as TargetScan and miR database. The R2 database, containing 105 NB patients, showed an inverse correlation between MYCN mRNA and deleted in lymphocytic leukemia (DLEU) 2, a host gene of miR‐15. Moreover, overexpression of miR‐15a, miR‐15b or miR‐16 significantly reduced the levels of MYCN mRNA and N‐Myc protein. Conversely, inhibiting miR dramatically enhanced MYCN mRNA and N‐Myc protein levels, as well as increasing mRNA half‐life in NB cells. By performing immunoprecipitation assays of argonaute‐2 (Ago2), a core component of the RNA‐induced silencing complex, we showed that miR‐15a, miR‐15b and miR‐16 interact with MYCN mRNA. Luciferase reporter assays showed that miR‐15a, miR‐15b and miR‐16 bind with 3’UTR of MYCN mRNA, resulting in MYCN suppression. Moreover, induced expression of miR‐15a, miR‐15b and miR‐16 significantly reduced the proliferation, migration, and invasion of NB cells. Finally, transplanting miR‐15a‐, miR‐15b‐ and miR‐16‐expressing NB cells into NSG mice repressed tumor formation and MYCN expression. These data suggest that miR‐15a, miR‐15b and miR‐16 exert a tumor‐suppressive function in NB by targeting MYCN. Therefore, these miRs could be considered as potential targets for NB treatment.

The coronavirus disease 2019 (COVID-19) is a viral disease caused by a novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) that affects the respiratory system of infected individuals. COVID-19 spreads between humans through respiratory droplets produced when an infected person coughs or sneezes. The COVID-19 outbreak originated in Wuhan, China at the end of 2019. As of 29 Sept 2020, over 235 countries, areas or territories across the globe reported a total of 33,441,919 confirmed cases, and 1,003,497 confirmed deaths due to COVID-19. Individuals of all ages are at risk for infection, but in most cases disease severity is associated with age and pre-existing diseases that compromise immunity, like cancer. Numerous reports suggest that people with cancer can be at higher risk of severe illness and related deaths from COVID-19. Therefore, managing cancer care under this pandemic is challenging and requires a collaborative multidisciplinary approach for optimal care of cancer patients in hospital settings. In this comprehensive review, we discuss the impact of the COVID-19 pandemic on cancer patients, their care, and treatment. Further, this review covers the SARS-CoV-2 pandemic, genome characterization, COVID-19 pathophysiology, and associated signaling pathways in cancer, and the choice of anticancer agents as repurposed drugs for treating COVID-19.

Recent advances in exosome biology have uncovered a significant role of exosomes in cancer and make them a determining factor in intercellular communication. Exosomes are types of extracellular vesicles that are involved in the communication between cells by exchanging various signaling molecules between the surrounding cells. Among various signaling molecules, long non-coding RNAs (lncRNAs), a type of non-coding RNA having a size of more than 200 nt in length and lacking protein-coding potential, have emerged as crucial regulators of intercellular communication. Tumor-derived exosomes containing various lncRNAs, known as exosomal lncRNAs, reprogram the microenvironment by regulating numerous cellular functions, including the regulation of gene transcription that favors cancer growth and progression, thus significantly determining the biological effects of exosomes. In addition, deregulated expression of lncRNAs is found in various human cancers and serves as a diagnostic biomarker to predict cancer type. The present review discusses the role of exosomal lncRNAs in the crosstalk between tumor cells and the surrounding cells of the microenvironment. Furthermore, we also discuss the involvement of exosomal lncRNAs within the tumor microenvironment in favoring tumor growth, metabolic reprogramming of tumor cells, and tumor-supportive autophagy. Therefore, lncRNAs can be used as a therapeutic target in the treatment of various human cancers.