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Breast cancers (BCs) are solid tumors composed of heterogeneous tissues consisting of cancer cells and an ever-changing tumor microenvironment (TME). The TME includes, among other non-cancer cell types, immune cells influencing the immune context of cancer tissues. In particular, the cross talk of immune cells and their interactions with cancer cells dramatically influence BC dissemination, immunoediting, and the outcomes of cancer therapies. Tumor-infiltrating lymphocytes (TILs), tumor-associated macrophages (TAMs), and myeloid-derived suppressor cells (MDSCs) represent prominent immune cell populations of breast TMEs, and they have important roles in cancer immunoescape and dissemination. Therefore, in this article we review the features of TILs, TAMs, and MDSCs in BCs. Moreover, we highlight the mechanisms by which these immune cells remodel the immune TME and lead to breast cancer metastasis.
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Neoplasias de la Mama , Linfocitos Infiltrantes de Tumor , Células Supresoras de Origen Mieloide , Metástasis de la Neoplasia , Microambiente Tumoral , Macrófagos Asociados a Tumores , Humanos , Microambiente Tumoral/inmunología , Neoplasias de la Mama/patología , Neoplasias de la Mama/inmunología , Células Supresoras de Origen Mieloide/inmunología , Células Supresoras de Origen Mieloide/metabolismo , Células Supresoras de Origen Mieloide/patología , Femenino , Macrófagos Asociados a Tumores/inmunología , Macrófagos Asociados a Tumores/metabolismo , Macrófagos Asociados a Tumores/patología , Linfocitos Infiltrantes de Tumor/inmunología , Linfocitos Infiltrantes de Tumor/metabolismo , Linfocitos T/inmunología , AnimalesRESUMEN
PURPOSE OF REVIEW: The aim of this review is to focus on the recent advances in the molecular knowledge of small cell lung cancer (SCLC) and potential promising new treatment strategies, like targeting the DNA damage pathway, epigenetics, angiogenesis, and oncogenic drivers. RECENT FINDINGS: In the last few years, the addition of immunotherapy to chemotherapy has led to significant improvements in clinical outcomes in this complex neoplasia. Nevertheless, the prognosis remains dismal. Recently, numerous genomic alterations have been identified, and they may be useful to classify SCLC into different molecular subtypes (SCLC-A, SCLC-I, SCLC-Y, SCLC-P). SCLC accounts for 10-20% of all lung cancers, most patients have an extensive disease at the diagnosis, and it is characterized by poor prognosis. Despite the progresses in the knowledge of the disease, efficacious targeted treatments are still lacking. In the near future, the molecular characterisation of SCLC will be fundamental to find more effective treatment strategies.
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Neoplasias Pulmonares , Carcinoma Pulmonar de Células Pequeñas , Humanos , Carcinoma Pulmonar de Células Pequeñas/tratamiento farmacológico , Carcinoma Pulmonar de Células Pequeñas/genética , Neoplasias Pulmonares/tratamiento farmacológico , Neoplasias Pulmonares/genética , Inmunoterapia , Pronóstico , Terapia Molecular DirigidaRESUMEN
The pathogenesis of complex diseases such as pulmonary arterial hypertension (PAH) is entirely rooted in changes in the expression of some vasoactive factors. These play a significant role in the onset and progression of the disease. Indeed, PAH has been associated with pathophysiologic alterations in vascular function. These are often dictated by increased oxidative stress and impaired modulation of the nitric oxide (NO) pathway. NO reduces the uncontrolled proliferation of vascular smooth muscle cells that leads to occlusion of vessels and an increase in pulmonary vascular resistances, which is the mainstay of PAH development. To date, two classes of NO-pathway modulating drugs are approved for the treatment of PAH: the phosphodiesterase-5 inhibitors (PD5i), sildenafil and tadalafil, and the soluble guanylate cyclase activator (sGC), riociguat. Both drugs provide considerable improvement in exercise capacity and pulmonary hemodynamics. PD5i are the recommended drugs for first-line PAH treatment, whereas sGCs are also the only drug approved for the treatment of resistant or inoperable chronic thromboembolic pulmonary hypertension. In this review, we will focus on the current information regarding the nitric oxide pathway and its modulation in PAH.
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Hipertensión Arterial Pulmonar , Humanos , Hipertensión Arterial Pulmonar/tratamiento farmacológico , Óxido Nítrico , Hipertensión Pulmonar Primaria Familiar , Inhibidores de Fosfodiesterasa 5/farmacología , Inhibidores de Fosfodiesterasa 5/uso terapéutico , Citrato de Sildenafil/farmacología , Citrato de Sildenafil/uso terapéutico , Guanilil Ciclasa SolubleRESUMEN
Anabolic deficiencies play a pivotal role in left-sided heart failure. Little is known about their impact on idiopathic pulmonary arterial hypertension (iPAH). Therefore, the aim of this study was to assess the impact of multiple hormone-metabolic deficiencies on clinical features and outcomes in idiopathic pulmonary arterial hypertension. We have demonstrated that the assessment of anabolic hormone levels in patients with iPAH allows the identification of a subpopulation with worse exercise capacity, pulmonary hemodynamics, right ventricular size, and function generating the hypothesis about the potential role of hormonal replacement therapy. These data should be confirmed by larger studies.
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Insuficiencia Cardíaca , Humanos , Hipertensión Pulmonar Primaria Familiar , HemodinámicaRESUMEN
During the sixth World Symposium on Pulmonary Hypertension, the threshold of mean pulmonary arterial pressure (mPAP) for the definition of pulmonary hypertension (PH) has been lowered to a value of greater than 20 mmHg, measured by means of right heart catheterization at rest. In this review, we aim at describing the impact of the new definition of PH, analyzing the available data from the latest scientific literature concerning subjects with mPAP between 21 and 24 mmHg (defined as "mildly elevated PH"), discussing the impact of the new threshold for mPAP in the clinical practice, and highlighting the new perspectives in this field.
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Hipertensión Pulmonar , Humanos , Hipertensión Pulmonar/diagnóstico , Cateterismo CardíacoRESUMEN
Biological sex and sociocultural gender are emerging as pivotal modifiers of health and diseases. Sex-based differences exist in the development, pathogenesis, and management of individuals with pulmonary arterial hypertension (PAH). The interplay between gender domains (ie, identity, roles, relations, and institutionalized gender) and PAH has been barely investigated. The aim of this narrative review is to describe up-to-date evidence on the integration of sex and gender in PAH research, highlighting areas for future investigation.
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Hipertensión Pulmonar , Masculino , Femenino , Humanos , Hipertensión Pulmonar/epidemiología , Hipertensión Pulmonar/terapia , Caracteres SexualesRESUMEN
In recent years, several observations reported that intolerance of physical exertion and other cardinal symptoms in heart failure (HF) are closely related to the functionality of the right ventricular (RV), regardless of left heart. It has been demonstrated that the RV dysfunction complicates the course, aggravates the quality of life, and increases the mortality of HF patients. The present review is aimed to report tips physicians about the current therapeutic management of right HF during acute stage and chronic phase, shedding light on the RV and its failure and providing physicians with essential information for everyday clinical practice.
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Insuficiencia Cardíaca , Disfunción Ventricular Derecha , Humanos , Calidad de Vida , Insuficiencia Cardíaca/complicaciones , Insuficiencia Cardíaca/terapia , Disfunción Ventricular Derecha/terapia , Disfunción Ventricular Derecha/complicaciones , Ventrículos CardíacosRESUMEN
BACKGROUND: Iron deficiency affects up to 50% of patients with pulmonary arterial hypertension (PAH) but iron markers such as ferritin and serum iron are confounded by several non-disease related factors like acute inflammation and diet. The aim of this study was to identify a new marker for iron deficiency and clinical outcome in PAH patients. METHODS: In this single-center, retrospective study we assessed indicators of iron status and clinical parameters specifying the time to clinical worsening (TTCW) and survival in PAH patients at time of initial diagnosis and at 1-year follow-up using univariable and multivariable analysis. RESULTS: In total, 150 patients were included with an invasively confirmed PAH and complete data on iron metabolism. The proportion of hypochromic erythrocytes > 2% at initial diagnosis was identified as an independent predictor for a shorter TTCW (p = 0.0001) and worse survival (p = 0.002) at initial diagnosis as well as worse survival (p = 0.016) at 1-year follow-up. Only a subset of these patients (64%) suffered from iron deficiency. Low ferritin or low serum iron neither correlated with TTCW nor survival. Severe hemoglobin deficiency at baseline was significantly associated with a shorter TTCW (p = 0.001). CONCLUSIONS: The presence of hypochromic erythrocytes > 2% was a strong and independent predictor of mortality and shorter TTCW in this cohort of PAH patients. Thus, it can serve as a valuable indicator of iron homeostasis and prognosis even in patients without iron deficiency or anemia. Further studies are needed to confirm the results and to investigate therapeutic implications.
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Eritrocitos/patología , Hemoglobinas/metabolismo , Hipertensión Arterial Pulmonar/sangre , Biomarcadores/sangre , Eritrocitos/metabolismo , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Pronóstico , Hipertensión Arterial Pulmonar/diagnóstico , Estudios RetrospectivosRESUMEN
The finest fraction of Particulate Matter (PM2.5) carries a large number of pollutants, some of which are assessed as genotoxic, such as some Polycyclic Aromatic Hydrocarbons (PAHs). In many countries, PM2.5 in combination with some PAHs are monitored to assess the concentrations of pollutants, while the air quality is rarely assessed by means of biological assays. Epidemiological studies have demonstrated a significant correlation between these two pollutants and human adverse effects, in particular on the respiratory system. Nevertheless, other air pollutants can induce a biological effect and the cumulative effect of the PM2.5 complex mixture may not be easily deduced by PM2.5 and PAH levels. This study aimed to combine the legislative monitoring of PM2.5 with the study of its mutagenicity. During a full year, daily air samples were collected in nine sites of the North-western Italy air quality monitoring network (Piedmont Region) and PM2.5 and PAH concentrations were assessed. Monthly pooled organic extracts were tested with the Salmonella assay using TA98 and TA100 strains, with and without metabolic activation (±S9), and using TA98NR and YG1021 strains. In all sites, a positive response was observed for TA98 and TA100 especially without S9. A significant mutagenic seasonal variation was detected, with higher mutagenicity in winter and lower responses in summer (average total mutagenicity ratio 27:1). The response of TA98NR and YG1021 compared with TA98 suggested a significant contribution of nitro-compounds to the mutagenicity. No significant differences were found between urban background and rural sites denoting the spread of pollution. A mutagenicity increase, 1.28 Total Mutagenicity Factor/20 m3, was observed for each PM2.5 µg increment. PAH levels and corresponding Toxic Equivalent Factors were highly correlated to mutagenicity results. This work confirms that complex environmental mixtures can be appropriately assessed through the implementation of physical-chemical analyzes with bioassays able to evaluate synergistic and antagonistic effects, especially for highest and lowest pollution settings.
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Contaminantes Atmosféricos , Contaminación del Aire , Hidrocarburos Policíclicos Aromáticos , Contaminantes Atmosféricos/análisis , Contaminantes Atmosféricos/toxicidad , Bioensayo , Humanos , Italia , Pruebas de Mutagenicidad , Mutágenos/toxicidad , Material Particulado/toxicidad , Hidrocarburos Policíclicos Aromáticos/análisis , Hidrocarburos Policíclicos Aromáticos/toxicidadRESUMEN
Exercise intolerance represents a typical feature of heart failure with preserved ejection fraction (HFpEF), and is associated with a poor quality of life, frequent hospitalizations, and increased all-cause mortality. The cardiopulmonary exercise test is the best method to quantify exercise intolerance, and allows detection of the main mechanism responsible for the exercise limitation, influencing treatment and prognosis. Exercise training programs improve exercise tolerance in HFpEF. However, studies are needed to identify appropriate type and duration. This article discusses the pathophysiology of exercise limitation in HFpEF, describes methods of determining exercise tolerance class, and evaluates prognostic implications and potential therapeutic strategies.
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Terapia por Ejercicio/métodos , Tolerancia al Ejercicio/fisiología , Insuficiencia Cardíaca/fisiopatología , Calidad de Vida , Volumen Sistólico/fisiología , Prueba de Esfuerzo , Insuficiencia Cardíaca/terapia , Humanos , PronósticoRESUMEN
BACKGROUND: Cancer stage is a determinant of survival of childhood central nervous system (CNS) cancers and could help the interpretation of survival variability among countries. Consensus guidelines to stage childhood malignancies in population cancer registries ("Toronto Childhood Cancer Stage Guidelines") have been recently proposed with the goal of data comparability. Indeed, stage is not systematically recorded in all registries and, when it is, different classification systems are used. We applied the Toronto Childhood Cancer Stage Guidelines to CNS cancer cases of three population-based cancer registries with the aim of evaluating the feasibility of staging this type of cancer and the critical points in the classification of CNS tumors. PROCEDURES: The Toronto Childhood Cancer Stage Guidelines were applied to 175 CNS patients, diagnosed from January 1, 2002 to December 31, 2014 in three cancer registries in Italy, and the percentage of cases that could be staged was assessed. RESULTS: One hundred eight of 126 (86%) medulloblastomas and other embryonal CNS cancers and 22 of 49 (45%) ependymomas were staged. Using these guidelines, survival of children with localized tumors could be discriminated from that of children with metastatic disease. CONCLUSIONS: The use of the Toronto Childhood Cancer Stage Guidelines is feasible for staging medulloblastoma in Italian population-based cancer registries, whereas it is more difficult for ependymomas. In Italy, cerebrospinal fluid examination, one of the decisive tests to stage CNS tumors, is not routinely performed as a first-line diagnosis procedure in ependymoma pediatric patients. A similar exercise by a larger number of cancer registries in different countries could suggest improvements in the childhood cancer staging system.
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Neoplasias del Sistema Nervioso Central/mortalidad , Neoplasias del Sistema Nervioso Central/patología , Estadificación de Neoplasias/normas , Guías de Práctica Clínica como Asunto/normas , Sistema de Registros/estadística & datos numéricos , Adolescente , Adulto , Niño , Preescolar , Manejo de Datos , Femenino , Estudios de Seguimiento , Humanos , Lactante , Recién Nacido , Masculino , Pronóstico , Programa de VERF , Tasa de Supervivencia , Adulto JovenRESUMEN
BACKGROUND: Cranial and spinal cerebrospinal fluid (CSF) leaks are associated with opposite CSF fluid dynamics. The differing pathophysiology between spontaneous cranial and spinal CSF leaks are, therefore, mutually exclusive in theory. OBSERVATIONS: A 66-year-old female presented with tension pneumocephalus. The patient underwent computed tomography (CT) scanning, which demonstrated left-sided tension pneumocephalus, with an expanding volume of air directly above a bony defect of the tegmen tympani and mastoideum. The patient underwent a left middle fossa craniotomy for repair of the tegmen CSF leak. In the week after discharge, she developed a recurrence of positional headaches and underwent head CT. Further magnetic resonance imaging of the brain and thoracic spine showed bilateral subdural hematomas and multiple meningeal diverticula. LESSONS: Cranial CSF leaks are caused by intracranial hypertension and are not associated with subdural hematomas. Clinicians should maintain a high index of suspicion for intracranial hypotension due to spinal CSF leak whenever "otogenic" pneumocephalus is found. Close postoperative follow-up and clinical monitoring for symptoms of intracranial hypotension in any patients who undergo repair of a tegmen defect for otogenic pneumocephalus is recommended.
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Early detection and treatment of cancer have led to a noticeable reduction in both mortality and morbidity. However, chemotherapy and radiotherapy could exert cardiovascular (CV) side effects, impacting survival and quality of life, independent of the oncologic prognosis. In this regard, a high clinical index of suspicion is required by the multidisciplinary care team in order to trigger specific laboratory tests (namely natriuretic peptides and high-sensitivity cardiac troponin) and appropriate imaging techniques (transthoracic echocardiography along with cardiac magnetic resonance, cardiac computed tomography, and nuclear testing (if clinically indicated)), leading to timely diagnosis. In the near future, we do expect a more tailored approach to patient care within the respective community along with the widespread implementation of digital health tools.
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AIMS: Testosterone deficiency (TD) is associated with increased morbidity and mortality in heart failure with reduced ejection fraction (HFrEF). However, data in women are scanty. The aim of this study was to investigate the prognostic impact of TD on women with HFrEF. METHODS: Among 480 patients prospectively enrolled in the T.O.S.CA. (Terapia Ormonale Scompenso CArdiaco) registry, a prospective, multicentre, nationwide, observational study, 94 women were included in the current analysis. The TD was defined as serum testosterone levels lower than 25 ng/dl. Data regarding clinical status, echocardiography, exercise performance, cardiovascular hospitalization, and survival after an average follow-up of 36 months were analysed. RESULTS: Thirty patients (31.9%) displayed TD. TD was associated with lower tricuspid annular plane excursion (TAPSE) to pulmonary arterial systolic pressure PASP ratio (TAPSE/PASP) (P = 0.008), peak oxygen consumption (VO2 peak) (P = 0.03) and estimated glomerular filtration rate (P < 0.001). TD was an independent predictor of the combined endpoint of all-cause mortality/cardiovascular hospitalization (HR: 10.45; 95% CI: 3.54-17.01; P = 0.001), all-cause mortality (HR: 8.33; 95%: 5.36-15.11; P = 0.039), and cardiovascular hospitalization (HR: 2.41; 95% CI: 1.13-4.50; P = 0.02). CONCLUSIONS: One-third of women with HFrEF displays TD that impacts remarkably on their morbidity and mortality. TD is associated with a worse clinical profile including exercise capacity, right ventricular-pulmonary arterial coupling, and renal function. These findings lend support to an accurate profiling of women with HF, a problem often overlooked in clinical trials.
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Insuficiencia Cardíaca , Hipertensión Pulmonar , Disfunción Ventricular Izquierda , Humanos , Femenino , Volumen Sistólico , Estudios Prospectivos , Sistema de Registros , TestosteronaRESUMEN
Cardiovascular (CV) diseases (CVD) are a major cause of long-term morbidity and mortality affecting life expectancy amongst cancer survivors. In recent years, because of the possibility of early diagnosis and the increased efficacy of neo-adjuvant and adjuvant systemic treatments (targeting specific molecular pathways), the high percentage of survival from breast cancer led CVD to become the first cause of death among survivors. Therefore, it is mandatory to adopt cardioprotective strategies to minimize CV side effects and CVD in general in breast cancer patients. Cancer therapeutics-related cardiac dysfunction (CTRCD) is a common group of side effects of chemotherapeutics widely employed in breast cancer (e.g., anthracycline and human epidermal growth factor receptor 2 inhibitors). The aim of the present manuscript is to propose a pragmatic multidisciplinary stepwise approach for prevention, early detection, and treatment of cardiotoxicity in patients with breast cancer.
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Data regarding further risk stratification of intermediate-risk pulmonary embolism (IR-PE) are scanty. Whether transthoracic echocardiography may be helpful in further risk assessment of death in such population has still to be proven. Two-hundred fifty-four consecutive patients (51.6% females, age 63.7 ± 17.3 years) with IR-PE admitted to a tertiary regional referral center were enrolled. Patients underwent a complete transthoracic echocardiography within 36 h from hospital admission, on top of clinical assessment, physical examination, computer tomography pulmonary angiography (CTPA), and serum measurement of Troponin I (TnI) levels. The occurrence of 90 day mortality was chosen as primary outcome measure. When compared to survivors, non-surviving IR-PE patients had smaller left-ventricular end-diastolic volumes (39.8 ± 20.9 vs 49.4 ± 19.9 ml/m2, p = 0.006) with reduced stroke volume index (SVi) (24.7 ± 10.9 vs 30.9 ± 12.6 ml/m2, p: 0.004) and time-velocity integral at left-ventricular outflow tract (VTILVOT) (0.17 ± 0.03 vs 0.20 ± 0.04 m, p = 0.0001), whereas no differences were recorded regarding right heart parameters. Cox regression analysis revealed that right atrial enlargement (RAE) (HR 3.432, 5-95% CI 1.193-9.876, p: 0.022), the ratio between tricuspid annulus plane excursion and pulmonary arterial systolic pressure (TAPSE/PASp) (HR 4.833, 5-95% 1.230-18.986, p = 0.024), as well as SVi (HR 11.199, 5-95% CI 2.697-48.096, p = 0.001) and VTILVOT (HR 4.212, 5-95% CI 1.384-12.820, p = 0.011) were powerful independent predictors of mortality. Neither CTPA RV/LV nor TnI resulted associated with impaired survival. In intermediate-risk pulmonary embolism, RAE, TAPSE/PASp ratio, SVi, and VTILVOT predict independently prognosis to a greater extent than CTPA and TnI.
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Embolia Pulmonar , Disfunción Ventricular Derecha , Anciano , Anciano de 80 o más Años , Ecocardiografía , Femenino , Humanos , Masculino , Persona de Mediana Edad , Pronóstico , Embolia Pulmonar/diagnóstico , Sístole , Troponina IRESUMEN
Heart failure with preserved ejection fraction (HFpEF) represents the most common HF phenotype of patients aged > 65 years, with an incidence and a prevalence that are constantly growing. The HFpEF cardinal symptom is exercise intolerance (EI), defined as the impaired ability to perform physical activity and to reach the predicted age-related level of exercise duration in the absence of symptomssuch as fatigue or dyspneaand is associated with a poor quality of life, a higher number of hospitalizations, and poor outcomes. The evidence of the protective effect between exercise and adverse cardiovascular outcomes is numerous and long-established. Regular exercise is known to reduce cardiovascular events and overall mortality both in apparently healthy individuals and in patients with established cardiovascular disease, representing a cornerstone in the prevention and treatment of many cardio-metabolic conditions. Several studies have investigated the role of exercise in HFpEF patients. The present review aims to dwell upon the effects of exercise on HFpEF. For this purpose, the relevant data from a literature search (PubMed, EMBASE, and Medline) were reviewed. The analysis of these studies underlines the fact that exercise training programs improve the cardiorespiratory performance of HFpEF patients in terms of the increase in peak oxygen uptake, the 6 min walk test distance, and the ventilatory threshold; on the other hand, diastolic or systolic functions are generally unchanged or only partially modified by exercise, suggesting that multiple mechanisms contribute to the improvement of exercise tolerance in HFpEF patients. In conclusion, considering that exercise training programs are able to improve the cardiorespiratory performance of HFpEF patients, the prescription of exercise training programs should be encouraged in stable HFpEF patients, and further research is needed to better elucidate the pathophysiological mechanisms underpinning the beneficial effects described.
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Oncolytic virotherapy is an emerging therapeutic approach based on replication-competent viruses able to selectively infect and destroy cancer cells, inducing the release of tumor-associated antigens and thereby recruiting immune cells with a subsequent increase in antitumoral immune response. To increase the anticancer activity, we engineered a specific oncolytic adenovirus expressing a single-chain variable fragment of an antibody against PD-L1 to combine blockage of PD-1/PD-L1 interaction with the antitumoral activity of Onc.Ad5. To assess its efficacy, we infected B16.OVA cells, a murine model of melanoma, with Ad5Δ24 -anti-PD-L1-scFv and then co-cultured them with C57BL/6J naïve splenocytes. We observed that the combinatorial treatments were significantly more effective in inducing cancer cell death. Furthermore, we assessed the efficacy of intratumoral administrations of Ad5Δ24-anti-PD-L1-scFv in C57BL/6J mice engrafted with B16.OVA and compared this treatment to that of the parental Ad5Δ24 or placebo. Treatment with the scFv-expressing Onc.Ad induced a marked reduction of tumor growth concerning the parental Onc.Ad. Additionally, the evaluation of the lymphocytic population infiltrating the treated tumor reveals a favorable immune profile with an enhancement of the CD8+ population. These data suggest that Onc.Ad-mediated expression of immune checkpoint inhibitors increases oncolytic virotherapy efficacy and could be an effective and promising tool for cancer treatments, opening a new way into cancer therapy.
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Osteogenic differentiation is a complex and still poorly understood biological process regulated by intrinsic cellular signals and extrinsic microenvironmental cues. Following appropriate stimuli, mesenchymal stem cells (MSCs) differentiate into osteoblasts through a tightly regulated multistep process driven by several transcription factors and characterized by the expression of a number of bone-specific proteins. In this study, we describe a novel transcription factor that we named osteoblast inducer (ObI)-1, involved in MSC differentiation toward the osteogenic lineage. ObI-1 encodes for a nuclear protein subjected to proteasomal degradation and expressed during osteoblast differentiation both in a murine multipotent mesenchymal cell line (W20-17) and in primary murine MSCs. RNA interference-mediated knockdown of ObI-1 expression significantly impairs osteoblast differentiation and matrix mineralization with reduced expression of the osteogenic markers, Runt-related transcription factor 2 (Runx2) and osteopontin. Conversely, ObI-1 overexpression enhances osteogenic differentiation and bone-specific markers expression. ObI-1 stimulates bone morphogenetic protein (BMP)-4 expression and the consequent activation of the Smad pathway; treatment with a BMP receptor type I antagonist completely abolishes ObI-1-mediated stimulation of osteogenic differentiation. Collectively, our findings suggest that ObI-1 modulates osteogenic differentiation, at least in part, through the BMP signaling pathway, increasing Runx2 activation and leading to osteoblast commitment and maturation.