Translation initiation in cancer at a glance.

Cell division, differentiation and function are largely dependent on accurate proteome composition and regulated gene expression. To control this, protein synthesis is an intricate process governed by upstream signalling pathways. Eukaryotic translation is a multistep process and can be separated into four distinct phases: initiation, elongation, termination and recycling of ribosomal subunits. Translation initiation, the focus of this article, is highly regulated to control the activity and/or function of eukaryotic initiation factors (eIFs) and permit recruitment of mRNAs to the ribosomes. In this Cell Science at a Glance and accompanying poster, we outline the mechanisms by which tumour cells alter the process of translation initiation and discuss how this benefits tumour formation, proliferation and metastasis.

Contrast-Enhanced In-Phase Dixon Sequence: Impact on Biopsy Clip Detection on Breast MRI.

BACKGROUND. Identification of breast biopsy clips using conventional MRI sequences may be challenging. A contrast-enhanced in-phase Dixon sequence may have greater conspicuity for areas of susceptibility compared with standard clinical sequences. OBJECTIVE. The purpose of this article is to compare detection of breast biopsy clips on MRI between the contrast-enhanced in-phase Dixon sequence and three routine clinical sequences. METHODS. This retrospective study included 164 patients (mean age, 50.3 years) with a total of 281 breast biopsy clips who underwent contrast-enhanced breast MRI between January 2, 2019, and April 16, 2020. Three radiologists, blinded to the clip location and sequence used, independently annotated biopsy clip locations on three clinical sequences (T1-weighted non-fat-suppressed [NFS], STIR, and first phase from dynamic contrast-enhanced T1-weighted fat-suppressed [FS]) and on a contrast-enhanced in-phase Dixon sequence and then recorded confidence scores (1-4 scale). A study coordinator used all available imaging and reports to localize clips on MRI, which served as the reference standard. A physicist measured clip CNR. Sequences were compared using the McNemar test and two-tailed Wilcoxon signed rank tests. RESULTS. Among the three readers, pooled sensitivity and PPV were 78.2% and 96.2% for T1-weighted NFS, 26.6% and 92.7% for STIR, 61.7% and 95.9% for contrast-enhanced T1-weighted FS, and 85.1% and 95.1% for contrast-enhanced in-phase Dixon sequence. Pooled sensitivity was higher for contrast-enhanced in-phase Dixon sequence than for the other sequences (all p < .05); pooled PPV was not significantly different between contrast-enhanced in-phase Dixon and the other sequences (all p > .05). Mean confidence scores (pooled across readers for true-positive assessments) and mean CNR were 3.0 ± 0.9 (SD) and 1.21 ± 0.61 for T1-weighted NFS, 1.7 ± 0.9 and 0.57 ± 0.69 for STIR, 2.5 ± 1.0 and 0.54 ± 0.61 for contrast-enhanced T1-weighted FS, and 3.5 ± 0.8 and 4.05 ± 2.6 for the contrast-enhanced in-phase Dixon sequence. Pooled mean confidence scores and CNR were higher for contrast-enhanced in-phase Dixon than for the other sequences (all p < .001). CONCLUSION. Compared with clinical sequences, the contrast-enhanced in-phase Dixon sequence had higher sensitivity for detecting breast biopsy clips on MRI and higher reader confidence and CNR, without change in PPV. CLINICAL IMPACT. The contrast-enhanced in-phase Dixon sequence may help address a current challenge in clinical breast MRI interpretation.

A common polymorphism in the 5' UTR of ERCC5 creates an upstream ORF that confers resistance to platinum-based chemotherapy.

We show that a common polymorphic variant in the ERCC5 5' untranslated region (UTR) generates an upstream ORF (uORF) that affects both the background expression of this protein and its ability to be synthesized following exposure to agents that cause bulky adduct DNA damage. Individuals that harbor uORF1 have a marked resistance to platinum-based agents, illustrated by the significantly reduced progression-free survival of pediatric ependymoma patients treated with such compounds. Importantly, inhibition of DNA-PKcs restores sensitivity to platinum-based compounds by preventing uORF1-dependent ERCC5 expression. Our data support a model in which a heritable 5' noncoding mRNA element influences individuals' responses to platinum-based chemotherapy.

TAp73 contributes to the oxidative stress response by regulating protein synthesis.

TAp73 is a transcription factor that plays key roles in brain development, aging, and cancer. At the cellular level, TAp73 is a critical homeostasis-maintaining factor, particularly following oxidative stress. Although major studies focused on TAp73 transcriptional activities have indicated a contribution of TAp73 to cellular metabolism, the mechanisms underlying its role in redox homeostasis have not been completely elucidated. Here we show that TAp73 contributes to the oxidative stress response by participating in the control of protein synthesis. Regulation of mRNA translation occupies a central position in cellular homeostasis during the stress response, often by reducing global rates of protein synthesis and promoting translation of specific mRNAs. TAp73 depletion results in aberrant ribosomal RNA (rRNA) processing and impaired protein synthesis. In particular, polysomal profiles show that TAp73 promotes the integration of mRNAs that encode rRNA-processing factors in polysomes, supporting their translation. Concurrently, TAp73 depletion causes increased sensitivity to oxidative stress that correlates with reduced ATP levels, hyperactivation of AMPK, and translational defects. TAp73 is important for maintaining active translation of mitochondrial transcripts in response to oxidative stress, thus promoting mitochondrial activity. Our results indicate that TAp73 contributes to redox homeostasis by affecting the translational machinery, facilitating the translation of specific mitochondrial transcripts. This study identifies a mechanism by which TAp73 contributes to the oxidative stress response and describes a completely unexpected role for TAp73 in regulating protein synthesis.

Adolescent Gender and Age Differences in Religiously and Spiritually Motivated Types of Forgiveness and the Relationship to Depressive Symptoms.

We examined three religiously/spiritually motivated forgiveness types, forgiveness of self, others, and divine forgiveness, and their association with depressive symptoms, across adolescent gender and age groups. Twelve- to 18-year-old patients arriving for primary care completed a 3-item Forgiveness measure and the Beck Depression Inventory-II. Girls reported a higher tendency to forgive others compared to boys, and self-forgiveness and divine forgiveness tended to decline with age in both genders. We found no significant associations between forgiveness and depression among boys. Among girls, higher self-forgiveness was associated with fewer depressive symptoms. Forgiveness of others was associated with less depression only among 17-18-year-old girls. Divine forgiveness showed no association with depression in either gender. Forgiveness of self and others appears to be protective factors for depression among adolescent girls.

Empirical validation of the CRAFFT Abuse Screening Test in a Spanish sample. / Validación empírica del CRAFFT Abuse Screening Test en una muestra de adolescentes españoles.

The CRAFFT Substance Abuse Screening Instrument, developed by the Center for Adolescents Substance Abuse Research (CeASAR) (Knight et al., 1999), is a screening tool for high-risk alcohol and drug risk consumption designed for use with adolescents. Since its publication it has been the subject of translations and validations in different countries, populations and contexts that have demonstrated its enormous potential. However, there is still no empirical validation study that would ensure its good psychometric performance in Spain. The aim of this paper is to develop an adapted version of the CRAFFT in Spanish and to analyze its psychometric properties in a sample of Spanish adolescents. For this purpose an individual interview was conducted on 312 adolescents aged between 12 and 18 years of age (M = 15.01; SD = 1.83) from the Galician community. The interview included a part of the Adolescent Diagnostic Interview (ADI) and the Problem Oriented Screening Instrument for Teenagers (POSIT). The results obtained, similar to those found in other countries, allow us to report that the Spanish version of the CRAFFT has a good psychometric behaviorproperties. It was found to have a satisfactory internal consistency with a Cronbach’s alpha value of .74. In terms of sensitivity and specificity, values of 74.4% and 96.4% respectively, were obtained and the area under the ROC curve was .946. The Spanish version of the CRAFFT is made available to researchers and professionals in the field of addictive behaviors, so that it can be used with the necessary psychometric guarantees.

El CRAFFT Abuse Screening Test, desarrollado por el Center for Adolescents Substance Abuse Research (CeASAR) (Knight et al., 1999), es una herramienta de cribado del consumo de riesgo de alcohol y otras sustancias diseñada para su uso con adolescentes. Desde su publicación ha sido objeto de numerosas traducciones y validaciones en diferentes países, poblaciones y contextos que han dado cuenta de su enorme potencial. No obstante, seguimos sin disponer de estudios de validación empírica que garanticen su adecuado comportamiento psicométrico en España. El objetivo del presente trabajo consiste en desarrollar una versión adaptada del CRAFFT en castellano y analizar sus propiedades psicométricas en una muestra de adolescentes españoles. Para ello, se realizó una entrevista individual a 312 adolescentes de entre 12 y 18 años (M = 15,01; DT = 1,83) de la comunidad gallega, que incluyó una parte de la Adolescent Diagnostic Interview (ADI) y del Problem Oriented Screening Instrument for Teenagers (POSIT). Los resultados obtenidos, similares a los encontrados en otros países, permiten informar que la versión española del CRAFFT presenta un buen comportamiento psicométrico. A nivel de consistencia interna se obtuvo un a de Cronbach satisfactorio de ,74. En cuanto a la sensibilidad y especificidad se obtuvieron unos valores del 74,4% y el 96,4% respectivamente, con un área bajo la curva COR de ,946. Por lo tanto, queda a disposición de investigadores y profesionales del ámbito de las conductas adictivas la versión española del CRAFFT, para que pueda ser utilizada en adelante con las garantías psicométricas necesarias.

Cooling-induced SUMOylation of EXOSC10 down-regulates ribosome biogenesis.

The RNA exosome is essential for 3' processing of functional RNA species and degradation of aberrant RNAs in eukaryotic cells. Recent reports have defined the substrates of the exosome catalytic domains and solved the multimeric structure of the exosome complex. However, regulation of exosome activity remains poorly characterized, especially in response to physiological stress. Following the observation that cooling of mammalian cells results in a reduction in 40S:60S ribosomal subunit ratio, we uncover regulation of the nuclear exosome as a result of reduced temperature. Using human cells and an in vivo model system allowing whole-body cooling, we observe reduced EXOSC10 (hRrp6, Pm/Scl-100) expression in the cold. In parallel, both models of cooling increase global SUMOylation, leading to the identification of specific conjugation of SUMO1 to EXOSC10, a process that is increased by cooling. Furthermore, we define the major SUMOylation sites in EXOSC10 by mutagenesis and show that overexpression of SUMO1 alone is sufficient to suppress EXOSC10 abundance. Reducing EXOSC10 expression by RNAi in human cells correlates with the 3' preribosomal RNA processing defects seen in the cold as well as reducing the 40S:60S ratio, a previously uncharacterized consequence of EXOSC10 suppression. Together, this work illustrates that EXOSC10 can be modified by SUMOylation and identifies a physiological stress where this regulation is prevalent both in vitro and in vivo.

p58IPK is an inhibitor of the eIF2α kinase GCN2 and its localization and expression underpin protein synthesis and ER processing capacity.

One of the key cellular responses to stress is the attenuation of mRNA translation and protein synthesis via the phosphorylation of eIF2α (eukaryotic translation initiation factor 2α). This is mediated by four eIF2α kinases and it has been suggested that each kinase is specific to the cellular stress imposed. In the present study, we show that both PERK (PKR-like endoplasmic reticulum kinase/eIF2α kinase 3) and GCN2 (general control non-derepressible 2/eIF2α kinase 4) are required for the stress responses associated with conditions encountered by cells overexpressing secreted recombinant protein. Importantly, whereas GCN2 is the kinase that is activated following cold-shock/hypothermic culturing of mammalian cells, PERK and GCN2 have overlapping functions since knockdown of one of these at the mRNA level is compensated for by the cell by up-regulating levels of the other. The protein p58IPK {also known as DnaJ3C [DnaJ heat-shock protein (hsp) 40 homologue, subfamily C, member 3]} is known to inhibit the eIF2α kinases PKR (dsRNA-dependent protein kinase/eIF2α kinase 2) and PERK and hence prevent or delay eIF2α phosphorylation and consequent inhibition of translation. However, we show that p58IPK is a general inhibitor of the eIF2α kinases in that it also interacts with GCN2. Thus forced overexpression of cytoplasmic p58 delays eIF2α phosphorylation, suppresses GCN2 phosphorylation and prolongs protein synthesis under endoplasmic reticulum (ER), hypothermic and prolonged culture stress conditions. Taken together, our data suggest that there is considerable cross talk between the eIF2α kinases to ensure that protein synthesis is tightly regulated. Their activation is controlled by p58 and the expression levels and localization of this protein are crucial in the capacity the cells to respond to cellular stress via control of protein synthesis rates and subsequent folding in the ER.

Eukaryotic elongation factor 2 kinase regulates the cold stress response by slowing translation elongation.

Cells respond to external stress conditions by controlling gene expression, a process which occurs rapidly via post-transcriptional regulation at the level of protein synthesis. Global control of translation is mediated by modification of translation factors to allow reprogramming of the translatome and synthesis of specific proteins that are required for stress protection or initiation of apoptosis. In the present study, we have investigated how global protein synthesis rates are regulated upon mild cooling. We demonstrate that although there are changes to the factors that control initiation, including phosphorylation of eukaryotic translation initiation factor 2 (eIF2) on the α-subunit, the reduction in the global translation rate is mediated by regulation of elongation via phosphorylation of eukaryotic elongation factor 2 (eEF2) by its specific kinase, eEF2K (eukaryotic elongation factor 2 kinase). The AMP/ATP ratio increases following cooling, consistent with a reduction in metabolic rates, giving rise to activation of AMPK (5'-AMP-activated protein kinase), which is upstream of eEF2K. However, our data show that the major trigger for activation of eEF2K upon mild cooling is the release of Ca2+ ions from the endoplasmic reticulum (ER) and, importantly, that it is possible to restore protein synthesis rates in cooled cells by inhibition of this pathway at multiple points. As cooling has both therapeutic and industrial applications, our data provide important new insights into how the cellular responses to this stress are regulated, opening up new possibilities to modulate these responses for medical or industrial use at physiological or cooler temperatures.

Control of translation in the cold: implications for therapeutic hypothermia.

Controlled whole-body cooling has been used since the 1950s to protect the brain from injury where cerebral blood flow is reduced. Therapeutic hypothermia has been used successfully during heart surgery, following cardiac arrest and with varied success in other instances of reduced blood flow to the brain. However, why reduced temperature is beneficial is largely unknown. Here we review the use of therapeutic hypothermia with a view to understanding the underlying biology contributing to the phenomenon. Interestingly, the benefits of cooling have recently been extended to treatment of chronic neurodegenerative diseases in two mouse models. Concurrently studies have demonstrated the importance of the regulation of protein synthesis, translation, to the cooling response, which is also emerging as a targetable process in neurodegeneration. Through these studies the potential importance of the rewarming process following cooling is also beginning to emerge. Altogether, these lines of research present new opportunities to manipulate cooling pathways for therapeutic gain.

The chaperonin CCT interacts with and mediates the correct folding and activity of three subunits of translation initiation factor eIF3: b, i and h.

eIF3 (eukaryotic initiation factor 3) is the largest and most complex eukaryotic mRNA translation factor in terms of the number of protein components or subunits. In mammals, eIF3 is composed of 13 different polypeptide subunits, of which five, i.e. a, b, c, g and i, are conserved and essential in vivo from yeasts to mammals. In the present study, we show that the eukaryotic cytosolic chaperonin CCT [chaperonin containing TCP-1 (tailless complex polypeptide 1)] binds to newly synthesized eIF3b and promotes the correct folding of eIF3h and eIF3i. Interestingly, overexpression of these last two subunits is associated with enhanced translation of specific mRNAs over and above the general enhancement of global translation. In agreement with this, our data show that, as CCT is required for the correct folding of eIF3h and eIF3i subunits, it indirectly influences gene expression with eIF3i overexpression enhancing both cap- and IRES (internal ribosome entry segment)-dependent translation initiation, whereas eIF3h overexpression selectively increases IRES-dependent translation initiation. Importantly, these studies demonstrate the requirement of the chaperonin machinery for the correct folding of essential components of the translational machinery and provide further evidence of the close interplay between the cell environment, cell signalling, cell proliferation, the chaperone machinery and translational apparatus.

Active regulator of SIRT1 is required for ribosome biogenesis and function.

Active regulator of SIRT1 (AROS) binds and upregulates SIRT1, an NAD(+)-dependent deacetylase. In addition, AROS binds RPS19, a structural ribosomal protein, which also functions in ribosome biogenesis and is implicated in multiple disease states. The significance of AROS in relation to ribosome biogenesis and function is unknown. Using human cells, we now show that AROS localizes to (i) the nucleolus and (ii) cytoplasmic ribosomes. Co-localization with nucleolar proteins was verified by confocal immunofluorescence of endogenous protein and confirmed by AROS depletion using RNAi. AROS association with cytoplasmic ribosomes was analysed by sucrose density fractionation and immunoprecipitation, revealing that AROS selectively associates with 40S ribosomal subunits and also with polysomes. RNAi-mediated depletion of AROS leads to deficient ribosome biogenesis with aberrant precursor ribosomal RNA processing, reduced 40S subunit ribosomal RNA and 40S ribosomal proteins (including RPS19). Together, this results in a reduction in 40S subunits and translating polysomes, correlating with reduced overall cellular protein synthesis. Interestingly, knockdown of AROS also results in a functionally significant increase in eIF2α phosphorylation. Overall, our results identify AROS as a factor with a role in both ribosome biogenesis and ribosomal function.

A group therapy program for opioid-dependent adolescents and their parents.

BACKGROUND: Opioid dependence is a significant problem for adolescents in the United States. Psychosocial treatment for adolescents with opioid use disorders may be effective, although it has not been well studied. METHODS: This paper describes a 13-week psychoeducational group therapy program with parallel tracks for adolescents with opioid use disorders and their parents attending an outpatient substance use program in a children's hospital. In addition to group therapy, participating adolescents received medical care, including medication-assisted treatment for opioid dependence, drug testing, medical follow-up, psychopharmacology, individual counseling, and parent guidance. Data were collected as part of a quality improvement project for the program. Forty-two adolescents and 72 parents attended the group program between 2006 and 2009. Frequencies were computed and a weighted kappa was used to assess agreement between adolescent and parent reports of use and driving risk. RESULTS: Of the 42 adolescents participating in the 13-week group program, 36 (86%) completed 3 or more group sessions, and 24 (57%) completed 10 or more sessions. Twenty-two (52%) adolescent participants reported abstinence from all substances on each of their weekly evaluations. Adolescent-parent agreement for substance use was good to very good: weighted kappa (95% confidence interval) .76 (.60, .87), but poor for driving risk, weighted kappa .11 (-.20, .40). CONCLUSIONS: Completion rates and self-report of outcomes from this group program indicate promise and warrant further testing.

Cyclin E is recruited to the nuclear matrix during differentiation, but is not recruited in cancer cells.

Cyclin E supports pre-replication complex (pre-RC) assembly, while cyclin A-associated kinase activates DNA synthesis. We show that cyclin E, but not A, is mounted upon the nuclear matrix in sub-nuclear foci in differentiated vertebrate cells, but not in undifferentiated cells or cancer cells. In murine embryonic stem cells, Xenopus embryos and human urothelial cells, cyclin E is recruited to the nuclear matrix as cells differentiate and this can be manipulated in vitro. This suggests that pre-RC assembly becomes spatially restricted as template usage is defined. Furthermore, failure to become restricted may contribute to the plasticity of cancer cells.

SIRT1, metabolism and cancer.

PURPOSE OF REVIEW: SIRT1 impacts upon diverse cellular processes via its roles in the determination of chromatin structure, chromatin remodelling and gene expression. This review covers the recent discoveries linking SIRT1 with the regulation of mammalian metabolism and considers ways in which abnormal metabolism in disease may, in turn, impact upon SIRT1 because of SIRT1's functional dependency upon NAD. RECENT FINDINGS: Diverse signalling pathways are integrated to regulate energy metabolism and homeostasis. Such pathways involve intracellular networks and mitochondria, and also intercellular signalling within and between tissues to co-ordinate adaptive metabolic responses within the organism as a whole. Here, we outline the recent studies exploring the regulatory links between SIRT1 and mitochondrial biogenesis, cellular redox and associated metabolic pathways, and angiogenesis/Notch signalling. These links are effected by the SIRT1-mediated deacetylation of transcriptional regulators and enzymes with key roles in metabolism. SUMMARY: SIRT1 activity is directly coupled with homeostasis and metabolism. SIRT1 is also a metabolic sensor. It follows that disease-related metabolic abnormalities are likely to impinge upon SIRT1 functioning. Disease-related functions of SIRT1, in their turn, offer potential targets for the development of novel SIRT1-based therapies. In cancer, for example, the survival function of SIRT1 may reflect abnormal cancer metabolism and identifies SIRT1 as a target for anticancer therapy.

Patient and Radiologist Demographics Influence Perceptions of Screening Mammography Reports.

PURPOSE: The aim of this study was to test whether patient and radiologist demographics influence perceptions of screening mammography reports and the interpreting radiologist. METHODS: Patients presenting for breast imaging were surveyed. Demographics were collected, and each participant was shown five mock screening mammography reports with BI-RADS category 2 findings, each with a recommendation for 1-year screening. Each report included a picture of the interpreting radiologist, who was Black or White and male or female. Participants answered seven questions, on a Likert-type scale, about understanding, satisfaction, and trust in the report and radiologist. Generalized estimating equation ordinal logistic regression compared responses on the basis of participant and radiologist demographics. RESULTS: A total of 178 women participated, with a mean age of 55.1 ± 10.2 years. Most participants self-identified as White (71%) or Black (20%) and non-Hispanic (98%), with broad educational representation (28% with bachelor's degrees and 28% with master's degrees). After controlling for demographics, Black participants reported greater agreement regarding trust in the report's finding (P = .037) if the radiologist was also Black. Black participants were less likely to be satisfied in the report quality (P = .043). Additionally, participants without any college education reported lower agreement that they were satisfied with the report quality (P = .020) and felt the radiologist cares about his or her patients (P = .037). There were no significant associations for radiologist sex or participant age. CONCLUSIONS: Participant perceptions of screening mammography reports and the interpreting radiologist can be influenced by participant and provider race as well as participant education. These findings could have implications for mammography adherence, breast radiologist recruitment, and developing patient-centric reports.

Perceived Risk of Harm Mediates the Effects of Primary Care Alcohol Use Screening and Brief Advice in Adolescents.

PURPOSE: A previous trial found lower alcohol use risk during follow-up among adolescent primary care patients receiving computer-facilitated Screening and provider Brief Advice (cSBA) compared to treatment-as-usual (TAU). We tested whether the effect was mediated by alcohol-related perceived risk of harm (PRoH). METHODS: We analyzed data from the cSBA trial on 12- to 18-year-old patients at 9 New England practices (n = 2,096, 58% females). The trial used a quasi-experimental pre-post design with practices being their own controls (TAU followed by cSBA). Because prior alcohol experience could modify effects, we stratified analyses by baseline past 12-month drinking. Among baseline nondrinkers, we tested baseline to 3-month trajectories in PRoH of "trying alcohol" as an effect mediator for drinking at 3- and 12-month follow-up. Similarly, among those with prior drinking, we examined baseline to 3-month trajectories in PRoH of "weekly binge drinking" as an effect mediator for drinking and binge drinking. We used the Hayes product of coefficients mediation approach. RESULTS: Among baseline nondrinkers (n = 1,449), cSBA had higher PRoH compared to TAU for "trying alcohol," and higher PRoH in turn was associated with lower follow-up drinking risk. PRoH mediated their cSBA effect at 12 months, but not 3 months. Among adolescents with prior drinking (n = 647), cSBA had higher PRoH for "weekly binge drinking," which was associated with lower drinking risk at both follow-ups, and lower binge drinking risk at 3 months. PRoH mediated their cSBA effect on drinking at both follow-ups, and binge drinking at 3 months. CONCLUSION: A computer-facilitated primary care intervention enhanced adolescents' perceived alcohol risks which in turn was associated with lower drinking risk.

Tuning protein synthesis for cancer therapy.

~50% of colorectal cancers have an activating mutation in KRAS (encoding the KRAS proto-oncogene) and remain difficult to target in the clinic. We have recently shown that activation of KRAS protein alters the regulation of mRNA translation, increasing total protein synthesis, and maintaining elevated c-MYC (MYC proto-oncogene) expression. Targeting these pathways downstream of KRAS reveals a striking dependency that has potential for clinical translation.

Pediatric Primary Care Provider Perspectives on a Computer-Facilitated Screening and Brief Intervention System for Adolescent Substance Use.

PURPOSE: This study aimed to elicit pediatric primary care providers' (PCPs) feedback on the acceptability and feasibility of implementing a tablet computer-facilitated Screening and Brief Intervention (cSBI) system for adolescent substance use in their practices. METHODS: We trained PCPs at five Boston area practices and enrolled their 12- to 18-year-old patients in a pilot randomized trial of cSBI versus usual care. PCPs completed an 18-item poststudy questionnaire. We computed frequencies and thematically coded open-ended responses. RESULTS: The analysis sample included 49 of 54 participating PCPs (90.7%). Overall, 89.8% of participants agreed the cSBI system was useful, and 81.6% reported increased confidence in providing brief counseling. Most useful were the immediate availability of screen results, talking points on substance use risks, and counseling prompts. Challenges included time and unfamiliarity with tablet computers. Many suggested electronic health record integration of cSBI to improve efficiency. CONCLUSIONS: cSBI showed high acceptability and increased confidence among pediatric PCPs. Feasibility could be enhanced by electronic health record integration.