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Video to go with: Prolonging the life of people with metastatic breast cancer in routine clinical practice by adding palbociclib to an aromatase inhibitor from a real-world database analysis: a plain language summary

Connie Chen,1 Mary Ayers,1 Judy H Squires,2 James E Squires1 1Division of Gastroenterology, Hepatology and Nutrition, UPMC Children’s Hospital of Pittsburgh, Pittsburgh, PA, USA; 2Department of Radiology, UPMC Children’s Hospital of Pittsburgh, Pittsburgh, PA, USACorrespondence: James E Squires, Division of Gastroenterology, Hepatology and Nutrition, Children’s Hospital of Pittsburgh, Pittsburgh, PA, 15224, Tel +1 412-692-5180, Fax +1 412-692-7355, Email James.Squires2@chp.eduAbstract: Sarcopenia, a pathologic deficiency of muscle mass and function, has emerged as an important secondary feature of many chronic disease states. For adults with end stage liver disease, there are multiple mechanisms which contribute to sarcopenia and its presence has proven to be an important predictor of morbidity and mortality. In children, there are only a limited number of reports which investigate the role of sarcopenia in liver disease. These studies, which are discussed and summarized in this review, report small, single-center analyses with dissimilar study cohorts and varying clinical definitions. Still, children meeting the study entry criteria have sarcopenia with a reported prevalence of 24– 70%. When assessed, sarcopenia appears to be associated with more severe disease but is independent of the Pediatric End-Stage Liver Disease (PELD) score and does not correlate with age, gender, or traditional anthropometric measures such as weight, height, weight-for-height, or body mass index (BMI). While individual studies may identify sarcopenia as a statistically significant risk factor for certain post-transplant outcomes such as longer ICU stay, longer duration of intubation, repeat operation, development of serious infection, longer hospital stay, death, or long-term growth failure, such associations are not consistently replicated across studies. Finally, although various methods of muscle mass quantification are utilized, the most reported is the total psoas muscle surface area (tPMSA) on computed tomography. This method, along with others such as skeletal muscle area and skeletal muscle index, have had normative values recently defined and these collective efforts should enable researchers a common basis of comparison when delineating sarcopenia, and its impact, across various study populations in future investigations – including in children with liver disease.Keywords: children, cirrhosis, muscle mass, end-stage liver disease, liver transplant

Purpose: To explore the journey taken by patients in a range of different countries to manage their dry eye symptoms. Method: Members of the general public who responded positively to the question “Do your eyes ever feel dry?” completed a questionnaire describing their demographics, the impact of their symptomology, the advice they have received and the management options they have tried. The Ocular Surface Disease Index (OSDI) questionnaire was also completed. Results: A total of 916 individuals (Canada = 235, Mexico = 127, New Zealand = 157, Taiwan = 246, UK = 151) of similar age distribution (median 38 years, IQR: 27–50) completed the survey. The reported duration of symptoms was longest in Canada (median 4 years, range 2–10) and least in Taiwan (2 years, range 1–3; p < 0.001), and similar trends were observed for symptom severity (p = 0.001). However, there was no statistically significant difference between countries with respect to the impact of symptoms on quality of life (median 3/10; p = 0.08). Less than half of the individuals in any country had consulted with a health professional. About half had tried a treatment for their dry eye symptoms, with artificial tears being the most common treatment, followed by warm compresses, and both therapies were rated as reasonably effective (median 5−7/10). Conclusion: Many people with dry eye symptoms are not consulting health care professionals who can confirm the diagnosis, exclude differential diagnoses, and offer a wide range of treatments targeted at the dry eye subtype.

Additional file 1: Table S1. Spearman correlations between immune cell subsets and CMV-microbe score.

BackgroundDepression and anxiety are leading causes of disability worldwide. Though effective treatments exist, depression and anxiety remain undertreated. Blended care psychotherapy, combining the scalability of online interventions with the personalization and engagement of a live therapist, is a promising approach for increasing access to evidence-based care.ObjectivesTo evaluate the effectiveness and individual contribution of two components - i) digital tools and ii) video-based therapist-led sessions - in a blended care CBT-based intervention under real world conditions.MethodsA retrospective cohort design was used to analyze N=1372 US-based individuals who enrolled in blended care psychotherapy. Of these, at baseline, 761 participants had depression symptoms in the clinical range (based on PHQ-9), and 1254 had anxiety symptoms in the clinical range (based on GAD-7). Participants had access to the program as a mental health benefit offered by their employer. The CBT-based blended care psychotherapy program consisted of regular video sessions with therapists, complemented by digital lessons and digital exercises assigned by the clinician and completed in between sessions. Depression and anxiety levels and clients' treatment engagement were tracked throughout treatment. A 3-level individual growth curve model incorporating time-varying covariates was utilized to examine symptom trajectories of PHQ-9 scores (for those with clinical range of depression at baseline) and GAD-7 scores (for those with clinical range of anxiety at baseline).ResultsOn average, individuals exhibited a significant decline in depression and anxiety symptoms during the initial weeks of treatment (P&nbsp

Primary bone tumor, also known as osteosarcoma (OS), is the most common primary malignancy of bone in children and young adults. Current treatment protocols yield a 5-year survival rate of near 70% although approximately 80% of patients have metastatic disease at the time of diagnosis. However, long-term survival rates have remained virtually unchanged for nearly four decades, largely due to our limited understanding of the disease process. One major signaling pathway that has been implicated in human OS tumorigenesis is the insulin-like growth factor (IGF)/insulin-like growth factor-1 receptor (IGF1R) signaling axis. IGF1R is a heterotetrameric α2β2 receptor, in which the α subunits comprise the ligand binding site, whereas the β subunits are transmembrane proteins containing intracellular tyrosine kinase domains. Although numerous strategies have been devised to target IGF/IGF1R axis, most of them have failed in clinical trials due to the lack of specificity and/or limited efficacy. Here, we investigated whether a more effective and specific blockade of IGF1R activity in human OS cells can be accomplished by employing dominant-negative IGF1R (dnIGF1R) mutants. We engineered the recombinant adenoviruses expressing two IGF1R mutants derived from the α (aa 1-524) and β (aa 741-936) subunits, and found that either dnIGF1Rα and/or dnIGF1Rβ effectively inhibited cell migration, colony formation, and cell cycle progression of human OS cells, which could be reversed by exogenous IGF1. Furthermore, dnIGF1Rα and/or dnIGF1Rβ inhibited OS xenograft tumor growth in vivo, with the greatest inhibition of tumor growth shown by dnIGF1Rα. Mechanistically, the dnIGF1R mutants down-regulated the expression of PI3K/AKT and RAS/RAF/MAPK, BCL2, Cyclin D1 and most EMT regulators, while up-regulating pro-apoptotic genes in human OS cells. Collectively, these findings strongly suggest that the dnIGF1R mutants, especially dnIGF1Rα, may be further developed as novel anticancer agents that target IGF signaling axis with high specificity and efficacy.

Background Current developmental toxicity testing adheres largely to protocols suggested in 1966 involving the administration of test compound to pregnant laboratory animals. After more than 50 years of embryo-fetal development testing, are we ready to consider a different approach to human developmental toxicity testing? Methods A workshop was held under the auspices of the Developmental and Reproductive Toxicology Technical Committee of the ILSI Health and Environmental Sciences Institute to consider how we might design developmental toxicity testing if we started over with 21st century knowledge and techniques (revolution). We first consider what changes to the current protocols might be recommended to make them more predictive for human risk (evolution). Results The evolutionary approach includes modifications of existing protocols and can include humanized models, disease models, more accurate assessment and testing of metabolites, and informed approaches to dose selection. The revolution could start with hypothesis-driven testing where we take what we know about a compound or close analog and answer specific questions using targeted experimental techniques rather than a one-protocol-fits-all approach. Central to the idea of hypothesis-driven testing is the concept that testing can be done at the level of mode of action. It might be feasible to identify a small number of key events at a molecular or cellular level that predict an adverse outcome and for which testing could be performed in vitro or in silico or, rarely, using limited in vivo models. Techniques for evaluating these key events exist today or are in development. Discussion Opportunities exist for refining and then replacing current developmental toxicity testing protocols using techniques that have already been developed or are within reach.

Many chemicals are going through a hazard-based classification and labeling process in Europe. Because of the significant public health implications, the best science must be applied in assessing developmental toxicity data. The European Teratology Society and Health and Environmental Sciences Institute co-organized a workshop to consider best practices, including data quality and consistency, interpretation of developmental effects in the presence of maternal toxicity, human relevance of animal data, and limits of chemical classes. Recommendations included larger historical control databases, more pharmacokinetic studies in pregnant animals for dose setting and study interpretation, generation of mechanistic data to resolve questions about whether maternal toxicity is causative of developmental toxicity, and more rigorous specifications for what constitutes a chemical class. It is our hope that these recommendations will form the basis for subsequent consensus workshops and other scientific activities designed to improve the scientific robustness of data interpretation for classification and labeling.

The implementation of treat-to-target principles in rheumatoid arthritis (RA) has not been fully investigated in patients with inadequate response to tumor necrosis factor (TNF) inhibitor treatment.To evaluate the prevalence of an inadequate response to initial TNF inhibitor treatment at 6 and 12 months among patients with RA in a real-world patient registry, as well as the delay in therapy adjustment and its impact on disease activity and patient-reported outcome (PRO) measures.This analysis is based on data of patients with moderate or severe disease activity (Clinical Disease Activity Index [CDAI] score10) who were included in the Consortium of Rheumatology Researchers of North America (Corrona) RA registry, a prospective, observational database. The patients had never received treatment with a biologic disease-modifying antirheumatic drug (DMARD) and had initiated treatment with a TNF inhibitor (adalimumab, certolizumab pegol, etanercept, golimumab, or infliximab) between October 2001 and December 2014. We evaluated treatment response (CDAI score ≤10), select PRO measures, and treatment changes at 6 months. Patients who had an inadequate response to TNF inhibitor therapy at 6 months and continued to use their initial TNF inhibitor were evaluated again at 12 months.This retrospective analysis included 2282 patients. At 6 months, 1732 (75.9%) of the patients continued to use their initial TNF inhibitor; of these, 803 (46.4%) patients had an inadequate response to treatment. Of the 803 patients who had an inadequate response at 6 months, 488 (60.8%) continued their initial treatment at 12 months. Of these 488 patients, 315 (64.5%) had an inadequate response at 12 months, and 173 (35.5%) had a response. Numerically greater improvements in all PRO measures were observed for patients who responded to therapy compared with patients with an inadequate response.In this real-world analysis of data from the Corrona RA registry, a considerable proportion of patients with RA had an inadequate response to the initial TNF inhibitor therapy at 6 and 12 months. Many patients continued to have moderate or high disease activity, without accelerating treatment (eg, addition or increase in the dose of concurrent conventional synthetic DMARDs or a TNF inhibitor), contrary to treat-to-target principles, thus remaining at risk for accumulating joint damage and disability.

The contribution of the host immune system to the efficacy of new anti-hepatitis C virus (HCV) drugs is unclear. We undertook a longitudinal prospective study of 33 individuals with chronic HCV treated with combination pegylated IFN-α, ribavirin, and telaprevir/boceprevir. We characterized innate and adaptive immune cells to determine whether kinetics of the host response could predict sustained virologic response (SVR). We show that characteristics of the host immune system present before treatment were correlated with successful therapy. Augmentation of adaptive immune responses during therapy was more impressive among those achieving SVR. Most importantly, active memory T cell proliferation before therapy predicted SVR and was associated with the magnitude of the HCV-specific responses at week 12 after treatment start. After therapy initiation, the most important correlate of success was minimal monocyte activation, as predicted by previous in vitro work. In addition, subjects achieving SVR had increasing expression of the transcription factor T-bet, a driver of Th1 differentiation and cytotoxic effector cell maturation. These results show that host immune features present before treatment initiation predict SVR and eventual development of a higher frequency of functional virus-specific cells in blood. Such host characteristics may also be required for successful vaccine-mediated protection.

OBJECTIVE: To investigate the effects of focal (hemiablation) or total cryotherapy and minimum tumor temperature on patient-reported quality of life (QoL) in prostate cancer patients. METHODS: An IRB-approved database was reviewed for patients who underwent cryotherapy or active surveillance (AS). QoL questionnaire responses were collected and scores were analyzed for differences between focal versus total cryotherapy and very cold (

The contribution of the host immune system to the efficacy of new anti-hepatitis C virus (HCV) drugs is unclear. We undertook a longitudinal prospective study of 33 individuals with chronic HCV treated with combination pegylated IFN-α, ribavirin, and telaprevir/boceprevir. We characterized innate and adaptive immune cells to determine whether kinetics of the host response could predict sustained virologic response (SVR). We show that characteristics of the host immune system present before treatment were correlated with successful therapy. Augmentation of adaptive immune responses during therapy was more impressive among those achieving SVR. Most importantly, active memory T cell proliferation before therapy predicted SVR and was associated with the magnitude of the HCV-specific responses at week 12 after treatment start. After therapy initiation, the most important correlate of success was minimal monocyte activation, as predicted by previous in vitro work. In addition, subjects achieving SVR had increasing expression of the transcription factor T-bet, a driver of Th1 differentiation and cytotoxic effector cell maturation. These results show that host immune features present before treatment initiation predict SVR and eventual development of a higher frequency of functional virus-specific cells in blood. Such host characteristics may also be required for successful vaccine-mediated protection.

In the United States, recent killings of civilians by law enforcement have propelled body cameras to the forefront of solutions to the “epidemic” of police misconduct. Preliminary studies suggest that body cameras create a win-win situation for both the police and the public by producing a civilizing effect on all parties involved. The problem, however, is that not every law enforcement agency has a body camera program. And among those that do, the surprising lack of legal action raises the question: How effective are body cameras in ensuring that justice is served? This Note discusses the use of body cameras in American policing on the streets and at the borders. It provides a background into the problem of police misconduct and highlights arguments in favor of and cautioning against body camera technology. Finally, in light of the Trump administration’s pro-law enforcement stance, this Note investigates high-profile police killings and assesses existing border policies to consider whether body cameras can truly deliver on their promise.

A database of embryo-fetal developmental toxicity (EFDT) studies of 379 pharmaceutical compounds in rat and rabbit was analyzed for species differences based on toxicokinetic parameters of area under the curve (AUC) and maximum concentration (Cmax) at the developmental lowest adverse effect level (dLOAEL). For the vast majority of cases (83% based on AUC of n = 283), dLOAELs in rats and rabbits were within the same order of magnitude (less than 10-fold different) when compared based on available data on AUC and Cmax exposures. For 13.5% of the compounds the rabbit was more sensitive and for 3.5% of compounds the rat was more sensitive when compared based on AUC exposures. For 12% of the compounds the rabbit was more sensitive and for 1.3% of compounds the rat was more sensitive based on Cmax exposures. When evaluated based on human equivalent dose (HED) conversion using standard factors, the rat and rabbit were equally sensitive. The relative extent of embryo-fetal toxicity in the presence of maternal toxicity was not different between species. Overall effect severity incidences were distributed similarly in rat and rabbit studies. Individual rat and rabbit strains did not show a different general distribution of systemic exposure LOAELs as compared to all strains combined for each species. There were no apparent species differences in the occurrence of embryo-fetal variations. Based on power of detection and given differences in the nature of developmental effects between rat and rabbit study outcomes for individual compounds, EFDT studies in two species have added value over single studies.

Tissue hypoxia has been implicated in the pathogenesis of various kidney diseases. Yet, because of technical limitations, temporal and spatial aspects of tissue hypoxia in the pathogenesis of kidney disease have received little attention. The recent development of the oxygen telemeter allowed for the possibility for the investigation into the contribution of tissue hypoxia in the progression of kidney diseases over long periods of time. We validated and established that the inherent offset in the telemeter was stable throughout the implantation period after a 5 day ‘bedding in’ period. The primary aim of this PhD project was to utilize the recently developed oxygen telemeter; the Clark electrode and pimonidazole adduct immunohistochemistry to determine both the temporal and spatial distribution of tissue hypoxia in the subacute phase of acute kidney injury induced by renal ischemia reperfusion injury. The tissue damage in response to an hour of anoxia was vast, such that tubular elements were often observed to be riddled with intraluminal casts, cellular sloughing and thinning of the epithelium. Interestingly, despite the extensive cellular damage, we could not detect tissue hypoxia at 24 h and 5 days after reperfusion of the kidney in both the cortex and the medulla using the oxygen telemeter and the Clark electrode. In contrast, the widespread staining pattern of pimonidazole adduct suggest otherwise i.e. cellular hypoxia was prominent in the subacute phase of ischemia reperfusion injury. A large proportion of these stained adducts was associated with tissue damage. Thus, the presence of these adducts was likely artifactual and is not reflective of ‘true hypoxia’. The absence of tissue hypoxia was likely contributed by the marked reduction of renal oxygen consumption and well maintained renal oxygen delivery. In conclusion, the absence of tissue hypoxia in the acute and subacute phase of ischemia reperfusion injury indicates that tissue hypoxia may not be an important driver of the pathogenesis of ischemia reperfusion injury. However, tissue damage in the subacute phase may lead to tissue hypoxia in the chronic phase of ischemia reperfusion injury. This line of inquiry could be investigated by instrumenting rats with the oxygen telemeter for weeks following recovery from ischemia surgery. Using Clark electrodes, we directly quantified tissue PO2 in rats with advanced polycystic kidney disease. There was extensive tissue hypoxia in both the renal parenchyma and within the cysts. Renal tissue hypoxia in these rats was driven by a greater reduction in renal oxygen delivery than renal oxygen consumption. The data presented in this thesis reinforce the need to consider both spatial and temporal aspects of tissue hypoxia in various forms of kidney disease in order to verify the importance of tissue hypoxia in driving the pathogenesis of kidney diseases.

Background The debate surrounding the acceptance of progression-free survival (PFS) as an intermediate endpoint to overall survival (OS) has grown in recent years, due to the challenges in demonstrating an OS benefit within clinical trials today. PFS is generally a good predictor of OS for cases where survival post-progression (SPP) is short, and less so when SPP is long. SPP depends on multiple factors, including residual effect from experimental treatment and effect from crossover or other subsequent therapies, posing unique challenges into the translation of PFS benefit into OS. Methods The objective of this analysis was to conduct simulations investigating how increasing SPP impacts PFS translation to OS, utilizing data from the AXIS (axitinib versus sorafenib in advanced metastatic renal cell carcinoma) trial. The underlying assumption was a treatment benefit in PFS (the PFS distribution parameters were chosen to be equal to median PFS in the AXIS trial) but no treatment effect on SPP, implying that PFS improvement is directly reflected in OS improvement. Results The probability of a statistically significant difference between arms for OS decreased from 54.7% to 6.1% when median SPP was increased from one to 20 months. The probability of the hazard ratio of OS being ≥0.9 was similarly increased from 24.3% to 72.6%, even though the hazard ratio for PFS was 0.69. Conclusion The present study shows that when simulated SPP is added to trial PFS data, the existing PFS benefit is diluted. Knowing that the AXIS treatment arms are well balanced with respect to post-trial treatments, we conclude that the PFS to OS benefit translation is primarily obscured by random variability largely unrelated to the true outcomes. The implications for drug development are not insignificant, as there would be a need to include more patients in studies or utilize a longer follow-up time to overcome the SPP variability issue.

In a previous phase 2 trial, axitinib was active and well tolerated in patients with advanced thyroid cancer. In this second phase 2 trial, the efficacy and safety of axitinib were evaluated further in this population, and pharmacokinetic/pharmacodynamic relationships and patient-reported outcomes were assessed.Patients (N = 52) with metastatic or unresectable, locally advanced medullary or differentiated thyroid cancer that was refractory or not amenable to iodine-131 received a starting dose of axitinib 5 mg twice daily. The primary endpoint was the objective response rate (ORR). Secondary endpoints included progression-free survival (PFS), overall survival (OS), safety, pharmacokinetic parameters, and patient-reported outcomes assessed with the MD Anderson Symptom Inventory questionnaire.The overall ORR was 35% (18 partial responses), and 18 patients had stable disease for ≥16 weeks. The median PFS was 16.1 months, and the median OS was 27.2 months. All-causality, grade ≥3 adverse events (5%) were fatigue, dyspnea, diarrhea, decreased weight, pain in extremity, hypertension, decreased appetite, palmar-plantar erythrodysesthesia, hypocalcemia, and myalgia. Patients who had greater axitinib exposure had a longer median PFS. Quality of life was maintained during treatment with axitinib, and no significant deterioration in symptoms or interference in daily life caused by symptoms, assessed on MD Anderson Symptom Inventory subscales, were observed.Axitinib has activity and a manageable safety profile while maintaining quality of life, and it represents an additional treatment option for patients with advanced thyroid cancer.

Beth Sherrill,1 James A Kaye,2 Rickard Sandin,3 Joseph C Cappelleri,4 Connie Chen51RTI Health Solutions, Biometrics, Research Triangle Park, NC, USA; 2RTI Health Solutions, Epidemiology, Research Triangle Park, NC, USA; 3Pfizer, Global Outcomes Research Sollentuna, Sweden; 4Pfizer, Biostatistics, Groton, CT, USA; 5Pfizer, Global Outcomes Research New York, NY, USAAbstract: Overall survival (OS) is the gold standard in measuring the treatment effect of new drug therapies for cancer. However, practical factors may preclude the collection of unconfounded OS data, and surrogate endpoints are often used instead. Meta-analyses have been widely used for the validation of surrogate endpoints, specifically in oncology. This research reviewed published meta-analyses on the types of surrogate measures used in oncology studies and examined the extent of correlation between surrogate endpoints and OS for different cancer types. A search was conducted in October 2010 to compile available published evidence in the English language for the validation of disease progression-related endpoints as surrogates of OS, based on meta-analyses. We summarize published meta-analyses that quantified the correlation between progression-based endpoints and OS for multiple advanced solid-tumor types. We also discuss issues that affect the interpretation of these findings. Progression-free survival is the most commonly used surrogate measure in studies of advanced solid tumors, and correlation with OS is reported for a limited number of cancer types. Given the increased use of crossover in trials and the availability of second-/third-line treatment options available to patients after progression, it will become increasingly more difficult to establish correlation between effects on progression-free survival and OS in additional tumor types.Keywords: progression endpoints, correlation, cancer

Traditional medicines, which include herbal remedies, acupuncture and spiritual therapies, have been used for millennia by various peoples to treat acute and chronic illnesses. In many developing countries, they remain the most accessible and most commonly used form of medical care (WHO, 2002). While pharmaceutical medicines are commonly used in developed countries to treat a vast range of infectious diseases and chronic conditions, patients in developing countries continue to rely on traditional medicines for several reasons. For one, herbal medicines are a far less expensive alternative to pharmaceutical drugs in most regions of the world. This makes them the only feasible option for impoverished families who cannot afford to buy Western pharmaceutical drugs, even if they wanted to do so. In countries such as Ghana, where malaria is endemic, a single course of pyrimathine/sulfadoxine antimalarial drugs can cost several dollars, whereas traditional Ghanaian herbal medicines are considerably less expensive (WHO, 2002). There is also a discrepancy in many countries in the number of traditional medicine practitioners as opposed to medical doctors available to the public. In Uganda, the ratio of traditional medicine practitioners to the total population is between 1:200 and 1:400, but the ratio of doctors to the total population is 1:20,000 (WHO, 2002). This limited access to Western medical professionals and pharmaceutical drugs necessitates, The Journal of Global Health at Columbia University, Vol. 2 No. 1 (2012): Spring 2012

Metastatic renal cell cancer is associated with poor long-term survival and has no cure. Traditional clinical endpoints are best supplemented by patient-reported outcomes designed to assess symptoms and function. Normative data was obtained on the National Comprehensive Cancer Network-Functional Assessment of Cancer Therapy-Kidney Symptom Index (NFKSI) to aid in score interpretation and planning of future trials.General population data were obtained from 2000 respondents, who completed the 19-item NFKSI-19, as well the SF-36 (Short Form 36-item instrument) and the PROMIS-29 (29-item Patient Reported Outcomes Measurement Information System), both general health status measures. Basic demographic and self-reported comorbidity data were also collected.The sample was 50% female, 85.7% caucasian, with an equal distribution across age bands from 18 years to 75 years and older. Most respondents (62.8%) had more than a high school education and reported an Eastern Cooperative Oncology Group performance status of normal activity without symptoms (63.4%). Score distributions on the NFKSI-19, its subscales, and individual items are summarized.The NFKSI-19 and its subscales now have scores for the general US population, allowing comparability to generic questionnaires such as the SF-36 and PROMIS-29. These data can be used to guide treatment expectations and plan future comparative effectiveness research using the scales.

SOX2 is a pan-neural transcription factor expressed in neural precursor cells (NPCs) independently of their regional identity. It plays a crucial role in both neural development and in adult neurogenesis; however the molecular mechanisms underlying its function are poorly understood. Our previous data suggested that SOX2 controls LIN28, an inhibitor of let-7 miRNA biogenesis. We hypothesized that some of the pan-neural functions of SOX2 could be mediated by repression of let-7 miRNA activity. To identify miRNAs with pan-neural SOX2 dependency, I used NPCs with two different regional identities, dorsal and ventral. I modified a previously established human embryonic stem cell (hESC)-derivation protocol (which generated dorsal NPCs) by patterning NPCs with the Sonic hedgehog agonist purmorphamine, yieding ventral NPCs. Analysis of SOX2 targets in dorsal and ventral NPCs in addition to bioinformatics suggested that SOX2 represses the levels of let-7b and let-7i miRNA. Overexpression studies of let-7b and let-7i revealed that let-7b selectively suppresses NPC proliferation with no effect on neuronal differentiation, while let-7i abolishes neuronal differentiation without inhibiting NPC proliferation. These data suggest that the combined effect of let-7b and let-7i overexpression in NPCs photocopies the loss of SOX2 in these cells. Taken together, our results suggest that in our in vitro cultures, SOX2 suppresses the activity of let-7 miRNAs in NPCs. We propose that the function of let- 7 miRNA family downstream of SOX2 may be a general mechanism for controlling both NPC proliferation and neurogenesis in developmental and adult contexts

Mesenchymal stem cells (MSCs) are capable of differentiating into bone, cartilage and adipose tissues. We identified BMP9 as the most potent osteoinductive BMP although detailed mechanism underlying BMP9-regulated osteogenesis of MSCs is indeterminate. Emerging evidence indicates that autophagy plays a critical role in regulating bone homeostasis. We investigated the possible role of autophagy in osteogenic differentiation induced by BMP9. We showed that BMP9 upregulated the expression of multiple autophagy-related genes in MSCs. Autophagy inhibitor chloroquine (CQ) inhibited the osteogenic activity induced by BMP9 in MSCs. While overexpression of ATG5 or ATG7 did not enhance osteogenic activity induced by BMP9, silencing Atg5 expression in MSCs effectively diminished BMP9 osteogenic signaling activity and blocked the expression of the osteogenic regulator Runx2 and the late marker osteopontin induced by BMP9. Stem cell implantation study revealed that silencing Atg5 in MSCs profoundly inhibited ectopic bone regeneration and bone matrix mineralization induced by BMP9. Collectively, our results strongly suggest a functional autophagy pathway may play an essential role in regulating osteogenic differentiation induced by BMP9 in MSCs. Thus, restoration of dysregulated autophagic activity in MSCs may be exploited to treat fracture healing, bone defects or osteoporosis.