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It is unknown which posttranscriptional regulatory mechanisms are required for oncogenic competence. Here, we show that the LIN28 family of RNA-binding proteins (RBPs), which facilitate posttranscriptional RNA metabolism within ribonucleoprotein networks, is essential for the initiation of diverse oncotypes of hepatocellular carcinoma (HCC). In HCC models driven by NRASG12V/Tp53, CTNNB1/YAP/Tp53, or AKT/Tp53, mice without Lin28a and Lin28b were markedly impaired in cancer initiation. We biochemically defined an oncofetal regulon of 15 factors connected to LIN28 through direct mRNA and protein interactions. Interestingly, all were RBPs and only 1 of 15 was a Let-7 target. Polysome profiling and reporter assays showed that LIN28B directly increased the translation of 8 of these 15 RBPs. As expected, overexpression of LIN28B and IGFBP1-3 was able to genetically rescue cancer initiation. Using this platform to probe components downstream of LIN28, we found that 8 target RBPs were able to restore NRASG12V/Tp53 cancer formation in Lin28a/Lin28b-deficient mice. Furthermore, these LIN28B targets promote cancer initiation through an increase in protein synthesis. LIN28B, central to an RNP regulon that increases translation of RBPs, is important for tumor initiation in the liver.

MYCN amplification ( MNA ) and disruption of tumor suppressor microRNA (TSmiR) function are key drivers of poor outcomes in neuroblastoma (NB). While MYCN and TSmiRs regulate glucose metabolism, their role in de novo fatty acid synthesis (FAS) and unsaturated FAS (UFAS) remains poorly understood. Here, we show that FAS and UFAS (U/FAS) genes FASN , ELOVL6 , SCD , FADS2 , and FADS1 are upregulated in high-risk (HR) NB and that their expression is associated with lower overall survival. RNA-Seq analysis of human NB cell lines revealed parallel U/FAS gene expression patterns. Consistent with this, we found that NB-related TSmiRs were predicted to target these genes extensively. We further observed that both MYC and MYCN upregulated U/FAS pathway genes while suppressing TSmiR host gene expression, suggesting a possible U/FAS regulatory network between MYCN and TSmiRs in NB. NB cells are high in de novo synthesized omega 9 (ω9) unsaturated fatty acids and low in both ω6 and ω3, suggesting a means for NB to limit cell-autonomous immune stimulation and reactive oxygen species (ROS)-driven apoptosis from ω6 and ω3 unsaturated fatty acid derivatives, respectively. We propose a model in which MYCN and TSmiRs regulate U/FAS and play an important role in NB pathology, with implications for other MYC family-driven cancers.

High expression of LIN28B is associated with aggressive malignancy and poor survival. Here, probing MYCN-amplified neuroblastoma as a model system, we showed that LIN28B expression was associated with enhanced cell migration in vitro and invasive and metastatic behavior in murine xenografts. Sequence analysis of the polyribosome fraction of LIN28B-expressing neuroblastoma cells revealed let-7-independent enrichment of transcripts encoding components of the translational and ribosomal apparatus and depletion of transcripts of neuronal developmental programs. We further observed that LIN28B utilizes both its cold shock and zinc finger RNA binding domains to preferentially interact with MYCN-induced transcripts of the ribosomal complex, enhancing their translation. These data demonstrated that LIN28B couples the MYCN-driven transcriptional program to enhanced ribosomal translation, thereby implicating LIN28B as a posttranscriptional driver of the metastatic phenotype.

Objective: The relationship between explicit nonsuicidal self-injury (NSSI) behavior and implicit identification with NSSI is important to understand considering the under-reported nature of NSSI and the subsequent elevated risk of more severe NSSI. It was expected that implicit assessment of NSSI at baseline would be associated with past-year NSSI frequency assessed at baseline and that it would more strongly associate with NSSI frequency than self-reported future likelihood of NSSI at a 6-month follow-up., Method: Data were collected from 420 young adults (mean age = 19; 83% women, 87% White) with recent NSSI at baseline, and 324 were assessed at 6-month follow-up. Participants completed self-report measures and the Self-Injury Implicit Association Task (SI-IAT) at each time point., Results: Baseline implicit NSSI scores significantly predicted NSSI frequency at baseline but not at 6-month follow-up. However, explicit ratings were strongly and significantly associated with future NSSI frequency., Conclusions: These findings suggest that although implicit identification with oneself and NSSI is important to understand, there are limitations regarding the possible utility of the SI-IAT in predicting future NSSI engagement and further research is needed to fully understand why NSSI continues to be such a strong predictor of future NSSI behavior, and suicidal ideation and behavior., (© 2021 The American Association of Suicidology.)

LIN28B is highly expressed in neuroblastoma and promotes tumorigenesis, at least, in part, through inhibition of let-7 microRNA biogenesis. Here, we report that overexpression of either wild-type (WT) LIN28B or a LIN28B mutant that is unable to inhibit let-7 processing increases the penetrance of MYCN-induced neuroblastoma, potentiates the invasion and migration of transformed sympathetic neuroblasts, and drives distant metastases in vivo. Genome-wide chromatin immunoprecipitation coupled with massively parallel DNA sequencing (ChIP-seq) and coimmunoprecipitation experiments show that LIN28B binds active gene promoters in neuroblastoma cells through protein-protein interaction with the sequence-specific zinc-finger transcription factor ZNF143 and activates the expression of downstream targets, including transcription factors forming the adrenergic core regulatory circuitry that controls the malignant cell state in neuroblastoma as well as GSK3B and L1CAM that are involved in neuronal cell adhesion and migration. These findings reveal an unexpected let-7 -independent function of LIN28B in transcriptional regulation during neuroblastoma pathogenesis., Competing Interests: Competing interest statement: B.J.A. is a shareholder in Syros Pharmaceuticals, Inc. The other authors declare no competing interest., (Copyright © 2020 the Author(s). Published by PNAS.)

Many attractive jobs in today's world require people to take on new challenges and figure out how to master them. As with any challenging goal, this involves systematic strategy use. Here we ask: Why are some people more likely to take a strategic stance toward their goals, and can this tendency be cultivated? To address these questions, we introduce the idea of a domain-general "strategic mindset." This mindset involves asking oneself strategy-eliciting questions, such as "What can I do to help myself?", "How else can I do this?", or "Is there a way to do this even better?", in the face of challenges or insufficient progress. In three studies ( n = 864), people who scored higher on (or were primed with) a strategic mindset reported using more metacognitive strategies; in turn, they obtained higher college grade point averages (GPAs) (Study 1); reported greater progress toward their professional, educational, health, and fitness goals (Study 2); and responded to a challenging timed laboratory task by practicing it more and performing it faster (Study 3). We differentiated a strategic mindset from general self-efficacy, self-control, grit, and growth mindsets and showed that it explained unique variance in people's use of metacognitive strategies. These findings suggest that being strategic entails more than just having specific metacognitive skills-it appears to also entail an orientation toward seeking and employing them., Competing Interests: The authors declare no competing interest., (Copyright © 2020 the Author(s). Published by PNAS.)

Background: For adults, the Collaborative Assessment and Management of Suicidality (CAMS; Jobes, (2006, Managing suicidal risk: A collaborative approach, New York, Guilford) and Jobes, (2016, Managing suicidal risk: A collaborative approach, New York, Guilford)) is a treatment framework with replicated evidenced-based support for effectiveness. The current study is a psychometric validation of the Suicide Status Form (SSF-IV), the main assessment and treatment planning tool for CAMS, in an adolescent psychiatric sample., Methods: Data were collected from 100 adolescents, aged 12-17, in inpatient settings (mean age = 14.6; 67.5% female, 80% white). Adolescents were administered Part A of the SSF-IV, as well as measures of overall suicide risk (both explicit and implicit), mental pain, Stress, Agitation, reasons for living, and self-esteem., Results: Confirmatory factor analysis found a two-factor model to fit the data best, with Psychological Pain, Stress, and Agitation loading on one factor, and Hopelessness and Self-Hate on another. All of the core SSF constructs except Stress were significantly correlated with concurrent measures, and SSF overall suicide risk was significantly correlated with self-reported and implicit suicidality. Adolescents with suicide attempt history reported significantly higher scores on most core SSF items compared to no attempt history., Conclusions: These results provide initial psychometric validation of the SSF for use with adolescents and indicate that it does not need to be adapted or modified for this age group., (© 2019 The American Association of Suicidology.)

Background: Diseases associated with coal mine dust continue to affect coal miners. Elucidation of initial pathological changes as a precursor of coal dust-related diffuse fibrosis and emphysema, may have a role in treatment and prevention., Objective: To identify the precursor of dust-related diffuse fibrosis and emphysema., Methods: Birefringent silica/silicate particles were counted by standard microscope under polarized light in the alveolar macrophages and fibrous tissue in 25 consecutive autopsy cases of complicated coal worker's pneumoconiosis and in 21 patients with tobacco-related respiratory bronchiolitis., Results: Coal miners had 331 birefringent particles/high power field while smokers had 4 (p<0.001). Every coal miner had intra-alveolar macrophages with silica/silicate particles and interstitial fibrosis ranging from minimal to extreme. All coal miners, including those who never smoked, had emphysema. Fibrotic septa of centrilobular emphysema contained numerous silica/silicate particles while only a few were present in adjacent normal lung tissue. In coal miners who smoked, tobacco-associated interstitial fibrosis was replaced by fibrosis caused by silica/silicate particles., Conclusion: The presence of silica/silicate particles and anthracotic pigment-laden macrophages inside the alveoli with various degrees of interstitial fibrosis indicated a new disease: coal mine dust desquamative chronic interstitial pneumonia, a precursor of both dust-related diffuse fibrosis and emphysema. In studied coal miners, fibrosis caused by smoking is insignificant in comparison with fibrosis caused by silica/silicate particles. Counting birefringent particles in the macrophages from bronchioalveolar lavage may help detect coal mine dust desquamative chronic interstitial pneumonia, and may initiate early therapy and preventive measures.

MYC is a major oncogenic driver of multiple myeloma (MM) and yet almost no therapeutic agents exist that target MYC in MM. Here we report that the let-7 biogenesis inhibitor LIN28B correlates with MYC expression in MM and is associated with adverse outcome. We also demonstrate that the LIN28B/let-7 axis modulates the expression of MYC, itself a let-7 target. Further, perturbation of the axis regulates the proliferation of MM cells in vivo in a xenograft tumor model. RNA-sequencing and gene set enrichment analyses of CRISPR-engineered cells further suggest that the LIN28/let-7 axis regulates MYC and cell cycle pathways in MM. We provide proof of principle for therapeutic regulation of MYC through let-7 with an LNA-GapmeR (locked nucleic acid-GapmeR) containing a let-7b mimic in vivo, demonstrating that high levels of let-7 expression repress tumor growth by regulating MYC expression. These findings reveal a novel mechanism of therapeutic targeting of MYC through the LIN28B/let-7 axis in MM that may impact other MYC-dependent cancers as well.

Signalling and post-transcriptional gene control are both critical for the regulation of pluripotency, yet how they are integrated to influence cell identity remains poorly understood. LIN28 (also known as LIN28A), a highly conserved RNA-binding protein, has emerged as a central post-transcriptional regulator of cell fate through blockade of let-7 microRNA biogenesis and direct modulation of mRNA translation. Here we show that LIN28 is phosphorylated by MAPK/ERK in pluripotent stem cells, which increases its levels via post-translational stabilization. LIN28 phosphorylation had little impact on let-7 but enhanced the effect of LIN28 on its direct mRNA targets, revealing a mechanism that uncouples LIN28's let-7-dependent and -independent activities. We have linked this mechanism to the induction of pluripotency by somatic cell reprogramming and the transition from naive to primed pluripotency. Collectively, our findings indicate that MAPK/ERK directly impacts LIN28, defining an axis that connects signalling, post-transcriptional gene control, and cell fate regulation.

Poor prognosis in neuroblastoma is associated with genetic amplification of MYCN. MYCN is itself a target of let-7, a tumour suppressor family of microRNAs implicated in numerous cancers. LIN28B, an inhibitor of let-7 biogenesis, is overexpressed in neuroblastoma and has been reported to regulate MYCN. Here we show, however, that LIN28B is dispensable in MYCN-amplified neuroblastoma cell lines, despite de-repression of let-7. We further demonstrate that MYCN messenger RNA levels in amplified disease are exceptionally high and sufficient to sponge let-7, which reconciles the dispensability of LIN28B. We found that genetic loss of let-7 is common in neuroblastoma, inversely associated with MYCN amplification, and independently associated with poor outcomes, providing a rationale for chromosomal loss patterns in neuroblastoma. We propose that let-7 disruption by LIN28B, MYCN sponging, or genetic loss is a unifying mechanism of neuroblastoma development with broad implications for cancer pathogenesis., Competing Interests: GQD holds options and intellectual property relating to 28/7 Therapeutics, a company seeking to develop inhibitors of the LIN28/let-7 pathway.

The two studies reported here tested whether a classroom-based psychological intervention that benefited a few African American 7th graders could trigger emergent ecological effects that benefited their entire classrooms. Multilevel analyses were conducted on data that previously documented the benefits of values affirmations on African American students' grades. The density of African American students who received the intervention in each classroom (i.e., treatment density) was used as an independent predictor of grades. Within a classroom, the greater the density of African American students who participated in the intervention exercise, the higher the grades of all classmates on average, regardless of their race or whether they participated in the intervention exercise. Benefits of treatment density were most pronounced among students with a history of poor performance. Results suggest that the benefits of psychological intervention do not end with the individual. Changed individuals can improve their social environments, and such improvements can benefit others regardless of whether they participated in the intervention. These findings have implications for understanding the emergence of ecological consequences from psychological processes., (© The Author(s) 2015.)

Reprogramming of fibroblasts to induced pluripotent stem cells (iPSCs) entails a mesenchymal to epithelial transition (MET). While attempting to dissect the mechanism of MET during reprogramming, we observed that knockdown (KD) of the epithelial-to-mesenchymal transition (EMT) factor SNAI1 (SNAIL) paradoxically reduced, while overexpression enhanced, reprogramming efficiency in human cells and in mouse cells, depending on strain. We observed nuclear localization of SNAI1 at an early stage of fibroblast reprogramming and using mouse fibroblasts expressing a knockin SNAI1-YFP reporter found cells expressing SNAI1 reprogrammed at higher efficiency. We further demonstrated that SNAI1 binds the let-7 promoter, which may play a role in reduced expression of let-7 microRNAs, enforced expression of which, early in the reprogramming process, compromises efficiency. Our data reveal an unexpected role for the EMT factor SNAI1 in reprogramming somatic cells to pluripotency., (Copyright © 2014 The Authors. Published by Elsevier Inc. All rights reserved.)

Lin28a/b are RNA-binding proteins that influence stem cell maintenance, metabolism, and oncogenesis. Poorly differentiated, aggressive cancers often overexpress Lin28, but its role in tumor initiation or maintenance has not been definitively addressed. We report that LIN28B overexpression is sufficient to initiate hepatoblastoma and hepatocellular carcinoma in murine models. We also detected Lin28b overexpression in MYC-driven hepatoblastomas, and liver-specific deletion of Lin28a/b reduced tumor burden, extended latency, and prolonged survival. Both intravenous siRNA against Lin28b and conditional Lin28b deletion reduced tumor burden and prolonged survival. Igf2bp proteins are upregulated, and Igf2bp3 is required in the context of LIN28B overexpression to promote growth. Therefore, multiple murine models demonstrate that Lin28b is both sufficient to initiate liver cancer and necessary for its maintenance., (Copyright © 2014 Elsevier Inc. All rights reserved.)

The Zcchc11 enzyme is implicated in microRNA (miRNA) regulation. It can uridylate let-7 precursors to decrease quantities of the mature miRNA in embryonic stem cell lines, suggested to mediate stem cell maintenance. It can uridylate mature miR-26 to relieve silencing activity without impacting miRNA content in cancer cell lines, suggested to mediate cytokine and growth factor expression. Broader roles of Zcchc11 in shaping or remodeling the miRNome or in directing biological or physiological processes remain entirely speculative. We generated Zcchc11-deficient mice to address these knowledge gaps. Zcchc11 deficiency had no impact on embryogenesis or fetal development, but it significantly decreased survival and growth immediately following birth, indicating a role for this enzyme in early postnatal fitness. Deep sequencing of small RNAs from neonatal livers revealed roles of this enzyme in miRNA sequence diversity. Zcchc11 deficiency diminished the lengths and terminal uridine frequencies for diverse mature miRNAs, but it had no influence on the quantities of any miRNAs. The expression of IGF-1, a liver-derived protein essential to early growth and survival, was enhanced by Zcchc11 expression in vitro, and miRNA silencing of IGF-1 was alleviated by uridylation events observed to be Zcchc11-dependent in the neonatal liver. In neonatal mice, Zcchc11 deficiency significantly decreased IGF-1 mRNA in the liver and IGF-1 protein in the blood. We conclude that the Zcchc11-mediated terminal uridylation of mature miRNAs is pervasive and physiologically significant, especially important in the neonatal period for fostering IGF-1 expression and enhancing postnatal growth and survival. We propose that the miRNA 3' terminus is a regulatory node upon which multiple enzymes converge to direct silencing activity and tune gene expression., Competing Interests: The authors have declared that no competing interests exist.

Mutation in the ABL kinase domain is the principal mechanism of imatinib resistance in patients with chronic myelogenous leukaemia. The second generation BCR/ABL inhibitors nilotinib and dasatinib effectively inhibit most imatinib resistance variants, but are ineffective against the gatekeeper mutant, T315I. Gatekeeper mutation activates the kinase by stabilizing the hydrophobic spine. Here, we describe that the rationally designed compound AP24163 can inhibit native and gatekeeper mutants of the BCR/ABL kinase. Structural modelling suggests that AP24163 affects the flexibility of the P-loop and destabilizes the active conformation by disrupting the hydrophobic spine. In vitro screening for drug resistance identified clones with compound mutations involving both the P-loop and T315I. Our studies provide structural insights for the design of inhibitors against the gatekeeper mutant and suggest that up-front combination therapy may be required to prevent the emergence of compound-resistant mutations.

Multiple members of the let-7 family of miRNAs are often repressed in human cancers, thereby promoting oncogenesis by derepressing targets such as HMGA2, K-Ras and c-Myc. However, the mechanism by which let-7 miRNAs are coordinately repressed is unclear. The RNA-binding proteins LIN28 and LIN28B block let-7 precursors from being processed to mature miRNAs, suggesting that their overexpression might promote malignancy through repression of let-7. Here we show that LIN28 and LIN28B are overexpressed in primary human tumors and human cancer cell lines (overall frequency approximately 15%), and that overexpression is linked to repression of let-7 family miRNAs and derepression of let-7 targets. LIN28 and LIN28b facilitate cellular transformation in vitro, and overexpression is associated with advanced disease across multiple tumor types. Our work provides a mechanism for the coordinate repression of let-7 miRNAs observed in a subset of human cancers, and associates activation of LIN28 and LIN28B with poor clinical prognosis.

Activation of the ATM DNA damage response pathway is commonly observed in a variety of early-stage neoplasias. It has been proposed that this checkpoint response functions to suppress the development of cancer. A recent report from our laboratory demonstrates that ATM does indeed function to suppress tumorigenesis by responding to at least some oncogenic stresses. Transgenic expression of Myc is found to cause DNA damage in vivo and ATM is shown to respond to this damage by inducing the accumulation and phosphorylation of p53. In the absence of ATM, p53-dependent apoptosis is reduced and epithelial tumorigenesis is accelerated in Myc transgenic mice. Deregulated expression of the E2F1 transcription factor also elicits an ATM-dependent checkpoint response that activates p53 and promotes apoptosis, although the mechanism by which E2F1 and Myc stimulate ATM may differ. These findings have relevance for understanding why the ATM pathway is activated in many human cancers, what generates the selective pressure for p53 inactivation during tumorigenesis, and why AT patients and carriers are predisposed to developing cancer.

Overexpression of the c-myc oncogene contributes to the development of a significant number of human cancers. In response to deregulated Myc activity, the p53 tumor suppressor is activated to promote apoptosis and inhibit tumor formation. Here we demonstrate that p53 induction in response to Myc overexpression requires the ataxia-telangiectasia mutated (ATM) kinase, a major regulator of the cellular response to DNA double-strand breaks. In a transgenic mouse model overexpressing Myc in squamous epithelial tissues, inactivation of Atm suppresses apoptosis and accelerates tumorigenesis. Deregulated Myc expression induces DNA damage in primary transgenic keratinocytes and the formation of gammaH2AX and phospho-SMC1 foci in transgenic tissue. These findings suggest that Myc overexpression causes DNA damage in vivo and that the ATM-dependent response to this damage is critical for p53 activation, apoptosis, and the suppression of tumor development.

The p53 tumor suppressor protein is phosphorylated and activated by several DNA damage-inducible kinases, such as ATM, and is a key effector of the DNA damage response by promoting cell cycle arrest or apoptosis. Deregulation of the Rb-E2F1 pathway also results in the activation of p53 and the promotion of apoptosis, and this contributes to the suppression of tumor development. Here, we describe a novel connection between E2F1 and the ATM DNA damage response pathway. In primary human fibroblasts lacking functional ATM, the ability of E2F1 to induce the phosphorylation of p53 and apoptosis is impaired. In contrast, ATM status has no effect on transcriptional activation of target genes or the stimulation of DNA synthesis by E2F1. Cells containing mutant Nijmegen breakage syndrome protein (NBS1), a component of the Mre11-Rad50 DNA repair complex, also have attenuated p53 phosphorylation and apoptosis in response to E2F1 expression. Moreover, E2F1 induces ATM- and NBS1-dependent phosphorylation of the checkpoint kinase Chk2 at Thr68, a phosphorylation site that stimulates Chk2 activity. Delayed gammaH2AX phosphorylation and absence of ATM autophosphorylation at Ser1981 suggest that E2F1 stimulates ATM through a unique mechanism that is distinct from agents that cause DNA double-strand breaks. These findings identify new roles for several DNA damage response factors by demonstrating that they also participate in the oncogenic stress signaling pathway between E2F1 and p53.

The ARF tumor suppressor participates in a p53-dependent apoptotic pathway that is stimulated in response to some oncogenic stimuli. The E2F1 transcription factor is a critical downstream target of the Rb tumor suppressor and, when active, can promote proliferation as well as apoptosis. The finding that E2F1 transcriptionally regulates the ARF gene has led to the suggestion that ARF contributes to E2F1-induced apoptosis. Counter to this hypothesis, this study demonstrates not only that ARF is unnecessary for E2F1 to induce apoptosis but also that inactivation of ARF actually enhances the ability of E2F1 to promote apoptosis. Inactivation of ARF also cooperates with E2F1 activity to promote entry into the S phase of the cell cycle. This relationship between ARF and E2F1 is demonstrated in transgenic epidermis in vivo and in mouse embryo fibroblast cultures in vitro. In contrast, the ability of Myc to induce apoptosis is diminished in the absence of ARF. E2F1 induces the accumulation of p53 in the absence of ARF, and this is associated with the phosphorylation of p53 on several residues. These findings demonstrate that ARF is a negative regulator of E2F1 activity and is not required for E2F1-induced apoptosis.