MiR-155-targeted IcosL controls tumor rejection.

Elevated levels of miR-155 in solid and liquid malignancies correlate with aggressiveness of the disease. In this manuscript, we show that miR-155 targets transcripts encoding IcosL, the ligand for Inducible T-cell costimulator (Icos), thus impairing the ability of T cells to recognize and eliminate malignant cells. We specifically found that overexpression of miR-155 in B cells of Eµ-miR-155 mice causes loss of IcosL expression as they progress toward malignancy. Similarly, in mice where miR-155 expression is controlled by a Cre-Tet-OFF system, miR-155 induction led to malignant infiltrates lacking IcosL expression. Conversely, turning miR-155 OFF led to tumor regression and emergence of infiltrates composed of IcosL-positive B cells and Icos-positive T cells forming immunological synapses. Therefore, we next engineered malignant cells to express IcosL, in order to determine whether IcosL expression would increase tumor infiltration by cytotoxic T cells and reduce tumor progression. Indeed, overexpressing an IcosL-encoding cDNA in MC38 murine colon cancer cells before injection into syngeneic C57BL6 mice reduced tumor size and increased intratumor CD8+ T cell infiltration, that formed synapses with IcosL-expressing MC38 cells. Our results underscore the fact that by targeting IcosL transcripts, miR-155 impairs the infiltration of tumors by cytotoxic T cells, as well as the importance of IcosL on enhancing the immune response against malignant cells. These findings should lead to the development of more effective anticancer treatments based on maintaining, increasing, or restoring IcosL expression by malignant cells, along with impairing miR-155 activity.

The differential expression of toll like receptors and RIG-1 correlates to the severity of infectious diseases.

The toll like receptors (TLRs) and RIG-1 are proteins involved in the initial reaction of the innate immune system to infectious diseases and, thus, can provide much information to the surgical pathologist in terms of the molecular dynamics of the infection. The TLRs (TLR1, 2, 3, 4, 7, 8) and RIG-1 distribution as determined by immunohistochemistry was examined in the following diseases: human papillomavirus (n = 30 including 15 squamous intraepithelial lesions (SIL), 5 cancers, and 10 controls); molluscum contagiosum (n = 8 including 4 controls), SARS-CoV2 (n = 52 including 20 mild, 5 fatal, and 27 controls) and reovirus infection as oncolytic therapy. Mild, regressing infection (molluscum contagiosum, mild SARS-CoV2 and low grade SIL) each showed the same pattern: marked up regulation of at least three of the TLRs/RIG-1 with decreased expression of none compared to the controls. Severe infection (fatal SARS-CoV2, and cervical cancer) each showed marked decrease expression in at least three of the TLRs/RIG-1. We recently documented an equivalent marked decrease expression of the TLRs/RIG-1 in the placenta in fatal in utero infections. The reoviral infected tissues showed an overall pattern of marked increase expression of TLRs/RIG-1, consistent with a strong anti-viral response. Thus, the in situ testing of infectious diseases by a panel of these early infectious disease recognition proteins may allow the surgical pathologist to predict the outcome of the disease which, in turn, may assist in the understanding of the role of the TLRs/RIG-1 in determining the fate of a given infectious process.

The differential immune response in mild versus fatal SARS-CoV2 infection.

This study compared the immune response in mild versus fatal SARS-CoV2 infection. Forty nasopharyngeal swabs with either productive mild infection (n = 20) or negative for SARS-CoV2 (n = 20) were tested along with ten lung sections from people who died of COVID-19 which contained abundant SARS-CoV2 and ten controls. There was a 25-fold increase in the CD3+T cell numbers in the viral positive nasopharyngeal swabs compared to the controls (p < 0.001) and no change in the CD3+T cell count in the fatal COVID-19 lungs versus the controls. CD11b + and CD206+ macrophage counts were significantly higher in the mild versus fatal disease (p = 0.002). In situ analysis for SARS-CoV2 RNA found ten COVID-19 lung sections that had no/rare detectable virus and also lacked the microangiopathy typical of the viral positive sections. These viral negative lung tissues when compared to the viral positive lung samples showed a highly significant increase in CD3+ and CD8 T cells (p < 0.001), equivalent numbers of CD163+ cells, and significantly less PDL1, CD11b and CD206+ cells (p = 0.002). It is concluded that mild SARS-CoV2 infection is marked by a much stronger CD3/CD8 T cell, CD11b, and CD206 macrophage response than the fatal lung disease where viral RNA is abundant.

The histologic and molecular correlates of liver disease in fatal COVID-19 including with alcohol use disorder.

Hepatic disease is common in severe COVID-19. This study compared the histologic/molecular findings in the liver in fatal COVID-19 (n = 9) and age-matched normal controls (n = 9); three of the fatal COVID-19 livers had pre-existing alcohol use disorder (AUD). Controls showed a high resident population of sinusoidal macrophages that had variable ACE2 expression. Histologic findings in the cases included periportal/lobular inflammation. SARS-CoV2 RNA and nucleocapsid protein were detected in situ in 2/9 COVID-19 livers in low amounts. In 9/9 cases, there was ample in situ SARS-CoV-2 spike protein that co-localized with viral matrix and envelope proteins. The number of cells positive for spike/100× field was significantly greater in the AUD/COVID-19 cases (mean 5.9) versus the non-AUD/COVID-19 cases (mean 0.4, p < 0.001) which was corroborated by Western blots. ACE2+ cells were 10× greater in AUD/COVID-19 livers versus the other COVID-19/control liver samples (p < 0.001). Co-expression experiments showed that the spike protein localized to the ACE2 positive macrophages and, in the AUD cases, hepatic stellate cells that were activated as evidenced by IL6 and TNFα expression. Injection of the S1, but not S2, subunit of spike in mice induced hepatic lobular inflammation in activated macrophages. It is concluded that endocytosed viral spike protein can induce hepatitis in fatal COVID-19. This spike induced hepatitis is more robust in the livers with pre-existing AUD which may relate to why patients with alcohol abuse are at higher risk of severe liver disease with SARS-CoV2 infection.

The amplification of CNS damage in Alzheimer's disease due to SARS-CoV2 infection.

Pre-existing Alzheimer's disease is a risk factor for severe/fatal COVID-19 and infection by SARS-CoV2 virus has been associated with an increased incidence of un-masked Alzheimer's disease. The molecular basis whereby SARS-CoV2 may amplify Alzheimer's disease is not well understood. This study analyzed the molecular changes in autopsy brain tissues from people with pre-existing dementia who died of COVID-19 (n = 5) which was compared to equivalent tissues of people who died of COVID-19 with no history of dementia (n = 8), Alzheimer's disease pre-COVID-19 (n = 10) and aged matched controls (n = 10) in a blinded fashion. Immunohistochemistry analyses for hyperphosphorylated tau protein, α-synuclein, and ß-amyloid-42 confirmed the diagnoses of Alzheimer's disease (n = 4), and Lewy body dementia (n = 1) in the COVID-19 group. The brain tissues from patients who died of COVID-19 with no history of dementia showed a diffuse microangiopathy marked by endocytosis of spike subunit S1 and S2 in primarily CD31+ endothelia with strong co-localization with ACE2, Caspase-3, IL6, TNFα, and Complement component 6 that was not associated with SARS-CoV2 RNA. Microglial activation marked by increased TMEM119 and MCP1 protein expression closely paralleled the endocytosed spike protein. The COVID-19 tissues from people with no pre-existing dementia showed, compared to controls, 5-10× fold increases in expression of neuronal NOS and NMDAR2 as well as a marked decrease in the expression of proteins whose loss is associated with worsening Alzheimer's disease: MFSD2a, SHIP1, BCL6, BCL10, and BACH1. In COVID-19 tissues from people with dementia the widespread spike-induced microencephalitis with the concomitant microglial activation co-existed in the same areas where neurons had hyperphosphorylated tau protein suggesting that the already dysfunctional neurons were additionally stressed by the SARS-CoV2 induced microangiopathy. ACE2+ human brain endothelial cells treated with high dose (but not vaccine equivalent low dose) spike S1 protein demonstrated each of the molecular changes noted in the in vivo COVID-19 and COVID-19/Alzheimer's disease brain tissues. It is concluded that fatal COVID-19 induces a diffuse microencephalitis and microglial activation in the brain due to endocytosis of circulating viral spike protein that amplifies pre-existing dementia in at least two ways: 1) modulates the expression of proteins that may worsen Alzheimer's disease and 2) stresses the already dysfunctional neurons by causing an acute proinflammatory/hypercoagulable/hypoxic microenvironment in areas with abundant hyperphosphorylated tau protein and/or ßA-42.

Histologic, viral, and molecular correlates of heart disease in fatal COVID-19.

Cardiac manifestations are common in severe COVID-19. This study compared the histologic, viral, and molecular findings in cardiac tissue in fatal COVID-19 (n = 11) and controls (n = 11). In situ hybridization (SARS-CoV2 RNA) and immunohistochemistry for viral proteins and the host response were quantified for the samples and compared with qRTPCR and Western blot data. Control hearts showed a high resident population of macrophages that had variable ACE2 expression. Cardiac ACE2 expression was 10× greater in the heart tissues of cases and controls with obesity or type II diabetes. Multifocal endothelial cell swelling and degeneration, perivascular edema plus microvascular thrombi were unique to the cases. SARS-CoV2 RNA and nucleocapsid protein were rarely detected in situ in any COVID-19 heart. However, in each case abundant SARS-CoV-2 spike protein was evident. Co-expression experiments showed that the spike protein localized mostly to the ACE2+ interstitial macrophages/pericytes that were activated as evidenced by increased IL6 and TNFα expression. Western blots confirmed the presence of the viral spike protein, but not the nucleocapsid protein, in the cardiac homogenates. The intercalated disc proteins connexin 43, the primary cardiac gap junction protein, and NaV1.5, the predominant cardiac sodium channel, each showed marked lateral migration in the myocytes in the cases, which would increase the risk of reentrant arrhythmias. It is concluded that the viral spike protein, endocytosed by macrophages/pericytes, can induce a myocarditis with the possibility of conduction dysfunction due to abnormal localization of key intercalated disc proteins.

Endothelial cell damage is the central part of COVID-19 and a mouse model induced by injection of the S1 subunit of the spike protein.

Neurologic complications of symptomatic COVID-19 are common. Brain tissues from 13 autopsies of people who died of COVID-19 were examined. Cultured endothelial and neuronal cells were incubated with and wild type mice were injected IV with different spike subunits. In situ analyses were used to detect SARS-CoV-2 proteins and the host response. In 13/13 brains from fatal COVID-19, pseudovirions (spike, envelope, and membrane proteins without viral RNA) were present in the endothelia of microvessels ranging from 0 to 14 positive cells/200× field (mean 4.3). The pseudovirions strongly co-localized with caspase-3, ACE2, IL6, TNFα, and C5b-9. The surrounding neurons demonstrated increased NMDAR2 and neuronal NOS plus decreased MFSD2a and SHIP1 proteins. Tail vein injection of the full length S1 spike subunit in mice led to neurologic signs (increased thirst, stressed behavior) not evident in those injected with the S2 subunit. The S1 subunit localized to the endothelia of microvessels in the mice brain and showed co-localization with caspase-3, ACE2, IL6, TNFα, and C5b-9. The surrounding neurons showed increased neuronal NOS and decreased MFSD2a. It is concluded that ACE2+ endothelial damage is a central part of SARS-CoV2 pathology and may be induced by the spike protein alone. Thus, the diagnostic pathologist can use either hematoxylin and eosin stain or immunohistochemistry for caspase 3 and ACE2 to document the endothelial cell damage of COVID-19.

Strong homology between SARS-CoV-2 envelope protein and a Mycobacterium sp. antigen allows rapid diagnosis of Mycobacterial infections and may provide specific anti-SARS-CoV-2 immunity via the BCG vaccine.

The vaccine BCG has been reported to offer protection against SARS-CoV-2 infection. It has been hypothesized this is based on nonspecific enhancement of innate immunity. This study addressed whether there is strong homology between a SARS-CoV-2 capsid protein and a Mycobacterium bovis protein that would allow for stronger, more specific immune protection. The study also showed the utility of immunohistochemistry in the diagnostic pathology laboratory for elucidating this information. Immunohistochemistry documented that an antibody directed against the SARS-CoV-2 envelope, but not the spike or membrane proteins, strongly cross hybridized to 11/11 Mycobacterial species tested, including M. bovis. BlastP analysis showed high homology of the SARS-CoV-2 envelope protein with 12 consecutive amino acids of the protein LytR C, which is a consensus protein unique to Mycobacteria. Six additional cases of human tuberculosis with few organisms showed that the viral envelope specific antibody (5/6) was more accurate than the AFB stain (2/6) for diagnostic purposes. These data indicate BCG vaccination induces a specific immunity against SARS CoV-2 that targets the viral envelope protein that is essential for infectivity. Thus, a concurrent booster or first use of the BCG vaccine may reduce the severity of the current COVID-19 pandemic. The data also suggests the value of using the SARS-CoV-2 envelope antibody in the diagnosis of Mycobacterial infections in formalin fixed, paraffin embedded tissues by the diagnostic pathologist.

miR-155 expression in antitumor immunity: The higher the better?

MicroRNAs are small noncoding RNAs that modulate gene expression either directly, by impairing the stability and/or translation of transcripts that contain their specific target sequence, or indirectly through the targeting of transcripts that encode transcription factors, factors implicated in signal transduction pathways, or epigenetic regulators. Abnormal expression of micro-RNAs has been found in nearly all types of pathologies, including cancers. MiR-155 has been the first microRNA to be implicated in the regulation of the innate and adaptative immune responses, and its expression is either increased or decreased in a variety of liquid and solid malignancies. In this review, we examine the oncogenic and antitumor potentials of miR-155, with special emphasize on its dose-dependent effects. We describe the impact of miR-155 levels on antitumor activity of lymphocytes and myeloid cells. We discuss miR-155 dose-dependent effects in leukemias and analyze results showing that miR-155 intermediate levels tend to be detrimental, whereas high levels of miR-155 expression usually prove beneficial. We also examine the beneficial effects of high levels of miR-155 expression in solid tumors. We discuss the possible causal involvement of miR-155 in leukemias and dementia in individuals with Down's syndrome. We finally propose that increasing miR-155 levels in immune cells might increase the efficiency of newly developed cancer immunotherapies, due to miR-155 ability to target transcripts encoding immune checkpoints such as cytotoxic T lymphocyte antigen-4 or programmed death-ligand 1.

MicroRNA-224 promotes tumor progression in nonsmall cell lung cancer.

Lung cancer is the leading cause of cancer-related deaths worldwide. Despite advancements and improvements in surgical and medical treatments, the survival rate of lung cancer patients remains frustratingly poor. Local control for early-stage nonsmall cell lung cancer (NSCLC) has dramatically improved over the last decades for both operable and inoperable patients. However, the molecular mechanisms of NSCLC invasion leading to regional and distant disease spread remain poorly understood. Here, we identify microRNA-224 (miR-224) to be significantly up-regulated in NSCLC tissues, particularly in resected NSCLC metastasis. Increased miR-224 expression promotes cell migration, invasion, and proliferation by directly targeting the tumor suppressors TNFα-induced protein 1 (TNFAIP1) and SMAD4. In concordance with in vitro studies, mouse xenograft studies validated that miR-224 functions as a potent oncogenic miRNA in NSCLC in vivo. Moreover, we found promoter hypomethylation and activated ERK signaling to be involved in the regulation of miR-224 expression in NSCLC. Up-regulated miR-224, thus, facilitates tumor progression by shifting the equilibrium of the partially antagonist functions of SMAD4 and TNFAIP1 toward enhanced invasion and growth in NSCLC. Our findings indicate that targeting miR-224 could be effective in the treatment of certain lung cancer patients.

microRNA 155 up regulation in the CNS is strongly correlated to Down's syndrome dementia.

This study examined the molecular correlates of Down's dementia. qRTPCR for chromosome 21 microRNAs was correlated with in situ hybridization, immunohistochemistry for microRNA targets, mRNAs located on chromosome 21, and neurofibrillary tangles in human and the Ts65 dn mouse Down's model. qRTPCR for the microRNAs on the triplicated chromosome showed miR-155 dominance in brain tissues (14.3 fold increase, human and 24.2 fold increase, mouse model) that co-expressed with hyperphosphorylated tau protein. miR-155 was not elevated in Alzheimer's disease or neonates with Downs' syndrome. Chromosome 21 genes APP/BA-42, DYRK1a and BACH1 were not correlated to pathologic changes in Down's dementia. Validated CNS targets of miR-155 that were present in controls and Alzheimer's disease but lacking in Down's dementia brains included BACH1, CoREST1, bcl6, BIM, bcl10, cyclin D, and SAPK4. It is concluded that Down's dementia strongly correlated with overexpression of chromosome 21 microRNA 155 with concomitant reduction of multiple CNS-functional targets. This study highlights the need for anatomic pathologists to determine the specific and diverse pathways cells may take to form neurofibrillary tangles in the different dementias.

MiR-155 deletion reduces ischemia-induced paralysis in an aortic aneurysm repair mouse model: Utility of immunohistochemistry and histopathology in understanding etiology of spinal cord paralysis.

Spinal cord paralysis is relatively common after surgical repair of thoraco-abdominal aortic aneurysm (TAAA) and its etiology is unknown. The present study was designed to examine the histopathology of the disease and investigate whether miR-155 ablation would reduce spinal cord ischemic damage and delayed hindlimb paralysis induced by aortic cross-clamping (ACC) in our mouse model. The loss of locomotor function in ACC-paralyzed mice correlated with the presence of extensive gray matter damage and central cord edema, with minimal white matter histopathology. qRTPCR and Western blotting showed that the spinal cords of wild-type ACC mice that escaped paralysis showed lower miR-155 expression and higher levels of transcripts encoding Mfsd2a, which is implicated in the maintenance of blood-brain barrier integrity. In situ based testing demonstrated that increased miR-155 detection in neurons was highly correlated with the gray matter damage and the loss of one of its targets, Mfsd2a, could serve as a good biomarker of the endothelial cell damage. In vitro, we demonstrated that miR-155 targeted Mfsd2a in endothelial cells and motoneurons and increased endothelial cell permeability. Finally, miR-155 ablation slowed the progression of central cord edema, and reduced the incidence of paralysis by 40%. In sum, the surgical pathology findings clearly indicated that the epicenter of the ischemic-induced paralysis was the gray matter and that endothelial cell damage correlated to Mfsd2a loss is a good biomarker of the disease. MiR-155 targeting therefore offers new therapeutic opportunity for edema caused by traumatic spinal cord injury and diagnostic pathologists, by using immunohistochemistry, can clarify if this mechanism also is important in other ischemic diseases of the CNS, including stroke.

Fluoroscopic-Guided Lumbar Spinal Drain Insertion for Thoracic Aortic Aneurysm Surgery.

We retrospectively reviewed the medical records of 11 patients who were referred by anesthesiologists to an interventional neuroradiologist for fluoroscopy-guided lumbar spinal drain insertion for thoracic aortic aneurysm repair between January 2010 and June 2015. Successful drain insertion was achieved in all patients. Three (27.3%) patients developed drain-related complications. Fluoroscopy-guided spinal drain insertion is an alternative to the conventional, nonimage-guided, blind technique used by anesthesiologists when they expect to encounter difficulty with insertion or in cases of failed insertion.

Spinal cord injury after thoracic endovascular aortic aneurysm repair.

PURPOSE: Thoracic endovascular aortic aneurysm repair (TEVAR) has become a mainstay of therapy for aneurysms and other disorders of the thoracic aorta. The purpose of this narrative review article is to summarize the current literature on the risk factors for and pathophysiology of spinal cord injury (SCI) following TEVAR, and to discuss various intraoperative monitoring and treatment strategies. SOURCE: The articles considered in this review were identified through PubMed using the following search terms: thoracic aortic aneurysm, TEVAR, paralysis+TEVAR, risk factors+TEVAR, spinal cord ischemia+TEVAR, neuromonitoring+thoracic aortic aneurysm, spinal drain, cerebrospinal fluid drainage, treatment of spinal cord ischemia. PRINCIPAL FINDINGS: Spinal cord injury continues to be a challenging complication after TEVAR. Its incidence after TEVAR is not significantly reduced when compared with open thoracoabdominal aortic aneurysm repair. Nevertheless, compared with open procedures, delayed paralysis/paresis is the predominant presentation of SCI after TEVAR. The pathophysiology of SCI is complex and not fully understood, though the evolving concept of the importance of the spinal cord's collateral blood supply network and its imbalance after TEVAR is emerging as a leading factor in the development of SCI. Cerebrospinal fluid drainage, optimal blood pressure management, and newer surgical techniques are important components of the most up-to-date strategies for spinal cord protection. CONCLUSION: Further experimental and clinical research is needed to aid in the discovery of novel neuroprotective strategies for the protection and treatment of SCI following TEVAR.

Long-range interaction and correlation between MYC enhancer and oncogenic long noncoding RNA CARLo-5.

The mechanism by which the 8q24 MYC enhancer region, including cancer-associated variant rs6983267, increases cancer risk is unknown due to the lack of protein-coding genes at 8q24.21. Here we report the identification of long noncoding RNAs named cancer-associated region long noncoding RNAs (CARLos) in the 8q24 region. The expression of one of the long noncoding RNAs, CARLo-5, is significantly correlated with the rs6983267 allele associated with increased cancer susceptibility. We also found the MYC enhancer region physically interacts with the active regulatory region of the CARLo-5 promoter, suggesting long-range interaction of MYC enhancer with the CARLo-5 promoter regulates CARLo-5 expression. Finally, we demonstrate that CARLo-5 has a function in cell-cycle regulation and tumor development. Overall, our data provide a key of the mystery of the 8q24 gene desert.

MicroRNAs play a central role in molecular dysfunctions linking inflammation with cancer.

It is now largely admitted that a pro-inflammatory environment may curtail anti-tumor immunity and favor cancer initiation and progression. The discovery that small non-coding regulatory RNAs, namely microRNAs (miRNAs), regulate all aspects of cell proliferation, differentiation, and function has shed a new light on regulatory mechanisms linking inflammation and cancer. Thus, miRNAs such as miR-21, miR-125b, miR-155, miR-196, and miR-210 that are critical for the immune response or hypoxia are often overexpressed in cancers and leukemias. Given the high number of their target transcripts, their deregulation may have a number of deleterious consequences, depending on the cellular context. In this review, we focus on how the factors encoded by transcripts targeted by these five miRNAs, be they transcription factors, tumor-suppressors, or regulators of different signaling pathways, can deregulate the immune response and favor pro-tumor immunity. Furthermore, we expose how the misdirected action of the main regulators of these miRNAs, such as nuclear factor κB (NF-κB), activator protein-1 (AP-1), and signal transduction and activators of transcription (STAT) transcription factors, or AKT and transforming growth factor ß (TGFß) signaling pathways, can contribute to decrease anti-tumor immunity and enhance cell proliferation and oncogenesis. We conclude by briefly discussing about how these discoveries may possibly lead to the development of new miRNA-based cancer therapies.

Promiscuous Effects of Some Phenolic Natural Products on Inflammation at Least in Part Arise from Their Ability to Modulate the Expression of Global Regulators, Namely microRNAs.

Recent years have seen the exploration of a puzzling number of compounds found in human diet that could be of interest for prevention or treatment of various pathologies. Although many of these natural products (NPs) have long been used as remedies, their molecular effects still remain elusive. With the advent of biotechnology revolution, NP studies turned from chemistry and biochemistry toward global analysis of gene expression. Hope is to use genetics to identify groups of patient for whom certain NPs or their derivatives may offer new preventive or therapeutic treatments. Recently, microRNAs have gained the statute of global regulators controlling cell homeostasis by regulating gene expression through genetic and epigenetic regulatory loops. Realization that certain plant polyphenols can modify microRNA expression and thus impact gene expression globally, initiated new, mainly in vitro studies, in particular to determine phytochemicals effects on inflammatory response, whose exacerbation has been linked to several disorders including cancer, auto-immune, metabolic, cardiovascular and neuro-inflammatory diseases. However, very few mechanistic insights have been provided, given the complexity of genetic regulatory networks implicated. In this review, we will concentrate on data showing the potential interest of some plant polyphenols in manipulating the expression of pro- and anti-inflammatory microRNAs in pathological conditions.

Ultraconserved regions encoding ncRNAs are altered in human leukemias and carcinomas.

Noncoding RNA (ncRNA) transcripts are thought to be involved in human tumorigenesis. We report that a large fraction of genomic ultraconserved regions (UCRs) encode a particular set of ncRNAs whose expression is altered in human cancers. Genome-wide profiling revealed that UCRs have distinct signatures in human leukemias and carcinomas. UCRs are frequently located at fragile sites and genomic regions involved in cancers. We identified certain UCRs whose expression may be regulated by microRNAs abnormally expressed in human chronic lymphocytic leukemia, and we proved that the inhibition of an overexpressed UCR induces apoptosis in colon cancer cells. Our findings argue that ncRNAs and interaction between noncoding genes are involved in tumorigenesis to a greater extent than previously thought.

The down-regulation of miR-125b in chronic lymphocytic leukemias leads to metabolic adaptation of cells to a transformed state.

MiR-125b-1 maps at 11q24, a chromosomal region close to the epicenter of 11q23 deletions in chronic lymphocytic leukemias (CLLs). Our results establish that both aggressive and indolent CLL patients show reduced expression of miR-125b. Overexpression of miR-125b in CLL-derived cell lines resulted in the repression of many transcripts encoding enzymes implicated in cell metabolism. Metabolomics analyses showed that miR-125b overexpression modulated glucose, glutathione, lipid, and glycerolipid metabolism. Changes on the same metabolic pathways also were observed in CLLs. We furthermore analyzed the expression of some of miR-125b-target transcripts that are potentially involved in the aforementioned metabolic pathways and defined a miR-125b-dependent CLL metabolism-related transcript signature. Thus, miR-125b acts as a master regulator for the adaptation of cell metabolism to a transformed state. MiR-125b and miR-125b-dependent metabolites therefore warrant further investigation as possible novel therapeutic approaches for patients with CLL.