ALK5 Research Articles

Highlights from Recent Cancer Literature

Highlights from Recent Cancer Literature

Variants in Inflammation Genes Are Implicated in Risk of Lung Cancer in Never Smokers Exposed to Second-hand Smoke

Lung cancer in lifetime never smokers is distinct from that in smokers, but the role of separate or overlapping carcinogenic pathways has not been explored. We therefore evaluated a comprehensive panel of 11,737 single-nucleotide polymorphisms (SNP) in inflammatory-pathway genes in a discovery phase (451 lung cancer cases, 508 controls from Texas). SNPs that were significant were evaluated in a second external population (303 cases, 311 controls from the Mayo Clinic). An intronic SNP in the ACVR1B gene, rs12809597, was replicated with significance and restricted to those reporting adult exposure to environmental tobacco smoke. Another promising candidate was an SNP in NR4A1, although the replication OR did not achieve statistical significance. ACVR1B belongs to the TGFR-β superfamily, contributing to resolution of inflammation and initiation of airway remodeling. An inflammatory microenvironment (second-hand smoking, asthma, or hay fever) is necessary for risk from these gene variants to be expressed. These findings require further replication, followed by targeted resequencing, and functional validation.

Early Clinical and Radiographic Characteristics in Fibrodysplasia Ossificans Progressiva

Fibrodysplasia ossificans progressiva is an extremely rare and disabling genetic condition characterized by progressive heterotopic ossification of soft tissues such as muscles, ligaments, tendons, fasciae, and aponeuroses. The prevalence of fibrodysplasia ossificans progressiva is estimated to be about one in 2 million individuals1. Heterotopic ossification in fibrodysplasia ossificans progressiva usually begins in the first decade of life with the episodic development of inflammatory fibroproliferative masses in the axial skeleton. Most patients with fibrodysplasia ossificans progressiva are misdiagnosed as having soft-tissue sarcoma or aggressive juvenile fibromatosis before the definitive appearance of heterotopic ossification and undergo invasive procedures that usually lead to the acceleration of ossification2. Early correct diagnosis of fibrodysplasia ossificans progressiva is necessary to prevent additional iatrogenic harm or trauma. At the molecular level, dysregulated bone morphogenetic protein (BMP) signaling is associated with the formation of heterotopic ossification in fibrodysplasia ossificans progressiva. Patients with classical features of the disease have the same heterozygous missense mutation in the glycine-serine activation domain of activin A receptor type-I gene (ACVR1), a BMP type-I receptor3. The causative mutation of fibrodysplasia ossificans progressiva is a recurrent single-nucleotide substitution at position 617 (c.617G>A; R206H) in the ACVR1 gene, which is one of the most specific disease-causing mutations in the human genome. This mutant receptor constitutively activates BMP signaling without binding of ligands4. A unique and recurrent mutation has great relevance for diagnostic purposes in the case of fibrodysplasia ossificans progressiva. Definitive molecular diagnosis of fibrodysplasia ossificans progressiva is now available at early stages of disease development, when misdiagnosis is most likely to occur. Clinical awareness of the preosseous features of the disease is necessary for the early diagnosis of fibrodysplasia ossificans progressiva. In the present study, we describe the cases of two patients in whom fibrodysplasia ossificans progressiva …

The tumor suppressor geneTrp53protects the mouse lens against posterior subcapsular cataracts and the BMP receptor Acvr1 acts as a tumor suppressor in the lens

SUMMARYWe previously found that lenses lacking the Acvr1 gene, which encodes a bone morphogenetic protein (BMP) receptor, had abnormal proliferation and cell death in epithelial and cortical fiber cells. We tested whether the tumor suppressor protein p53 (encoded by Trp53) affected this phenotype. Acvr1 conditional knockout (Acvr1CKO) mouse fiber cells had increased numbers of nuclei that stained for p53 phosphorylated on serine 15, an indicator of p53 stabilization and activation. Deletion of Trp53 rescued the Acvr1CKO cell death phenotype in embryos and reduced Acvr1-dependent apoptosis in postnatal lenses. However, deletion of Trp53 alone increased the number of fiber cells that failed to withdraw from the cell cycle. Trp53CKO and Acvr1;Trp53DCKO (double conditional knockout), but not Acvr1CKO, lenses developed abnormal collections of cells at the posterior of the lens that resembled posterior subcapsular cataracts. Cells from human posterior subcapsular cataracts had morphological and molecular characteristics similar to the cells at the posterior of mouse lenses lacking Trp53. In Trp53CKO lenses, cells in the posterior plaques did not proliferate but, in Acvr1;Trp53DCKO lenses, many cells in the posterior plaques continued to proliferate, eventually forming vascularized tumor-like masses at the posterior of the lens. We conclude that p53 protects the lens against posterior subcapsular cataract formation by suppressing the proliferation of fiber cells and promoting the death of any fiber cells that enter the cell cycle. Acvr1 acts as a tumor suppressor in the lens. Enhancing p53 function in the lens could contribute to the prevention of steroid- and radiation-induced posterior subcapsular cataracts.

A systematic analysis of the skeletal muscle miRNA transcriptome of chicken varieties with divergent skeletal muscle growth identifies novel miRNAs and differentially expressed miRNAs

BackgroundFunctional studies have demonstrated that microRNAs (miRNAs or miRs) play critical roles in a wide spectrum of biological processes including development and disease pathogenesis. To investigate the functional roles that miRNAs play during chicken skeletal muscle development, the miRNA transcriptomes of skeletal muscles from broiler and layer chickens were profiled using Solexa deep sequencing.ResultsSome miRNAs have multiple isoforms and several miRNAs* are present at higher levels than their corresponding miRNAs. Thirty three novel and 189 known chicken miRNAs were identified using computational approaches. Subsequent miRNA transcriptome comparisons and real-time PCR validation experiments revealed 17 miRNAs that were differentially expressed between broilers and layers, and a number of targets of these miRNAs have been implicated in myogenesis regulation. Using integrative miRNA target-prediction and network-analysis approaches an interaction network of differentially expressed and muscle-related miRNAs and their putative targets was constructed, and miRNAs that could contribute to the divergent muscle growth of broiler and layer chickens by targeting the ACVR2B gene were identified, which can causes dramatic increases in muscle mass.ConclusionsThe present study provides the first transcriptome profiling-based evaluation of miRNA function during skeletal muscle development in chicken. Systematic predictions aided the identification of potential miRNAs and their targets, which could contribute to divergent muscle growth in broiler and layer chickens. Furthermore, these predictions generated information that can be utilized in further research investigating the involvement of interaction networks, containing miRNAs and their targets, in the regulation of muscle development.

Craniofacial findings in fibrodysplasia ossificans progressiva: computerized tomography evaluation

The aim of this study was the evaluation by using computerized tomography (CT) of craniofacial abnormalities in fibrodysplasia ossificans progressiva (FOP) patients regarding jaw restriction and retrognathia. Seven FOP patients were evaluated retrospectively in this observational study. Inclusion criteria were detection of ACVR1 gene mutation and complete craniofacial CT examination. The age of jaw restriction and presence of retrognathia were clinically determined. The features analyzed were skull base structures and heterotopic ossification (HO). Of this group (age range 4-23 years), the 3 oldest patients presented with jaw restriction and retrognathia as well as displayed elongation of the lateral pterygoid plate with HO of the pterygoid muscles that reached the medial surface of the right mandibular ramus. They had significant history of trauma or surgery. The other 4 patients did not have retrognathia or HO involving the facial or masticatory muscles, and the mouth opening was normal. CT evaluation can reveal HO of the pterygoid muscles that probably may cause jaw restriction and retrognathia in older FOP patients.

Fibrodysplasia ossificans progressiva 환자의 증례보고 및 치과 치료시 고려 사항

Fibrodysplasia ossificans progressiva(FOP) is characterized by episodes of permanent heterotopic ossifications of soft tissues throughout the body. FOP is inherited in an autosomal dominant pattern, but most cases result from new mutations in the ACVR1 gene. Even minimal trauma can cause permanent ossifications of soft tissues and give rise to complications following routine dental care. Dental block anesthesia, severe stretching of the jaw and biopsies are all contraindicated in children with FOP. There is no effective treatment. Since the prevalence of FOP is very low and most patients with FOP are misdiagnosed during childhood, they undergo dangerous and unnecessary treatment that can lead to permanent harm. For patients with FOP, early diagnosis and prevention of complications are most important. This study aims at contemplating the characteristic features and consideration factors for the dental treatment of FOP patients in relation to the case of an eight years-and-one month old boy who was referred to Pediatric Dentistry due to prolonged retention of mandibular right and left deciduous central incisors after being diagnosed with sporadic FOP at Pediatric Orthopaedics, Seoul National University Hospital, and received dental treatment without the exacerbation of the FOP symptoms.

Are great toes always abnormal in patients with fibrodysplasia ossificans progressiva?

Sir,We read with interest a recent paper by Kartal-Kaess andcolleagues [3] reporting a child who had episodic andprogressive heterotopic ossification along with congenitallymalformed great toes. On the basis of these findings, aclinical diagnosis of fibrodysplasia ossificans progressiva(FOP) was made and was confirmed by DNA sequenceanalysis which revealed the classical FOP mutation in theACVR1 gene (c.617G>A). The authors concluded that allclassically affected patients have congenital malformationsof the great toe, and this finding helps in establishing thediagnosis of FOP.Recently, a few studies [1, 2] analyzed phenotypicvariations in patients with FOP along with mutations inthe ACVR1 gene. In the largest study on FOP, so far,Kaplan [2] identified 20 patients with atypical phenotypes,of which five had normal great toes (clinically andradiologically). Also, in a study of Italian patients withFOP, Bocciardi [1] described a patient of FOP with normaltoes. All these patients were diagnosed with FOP butexperienced episodes of heterotopic soft tissue ossificationof milder severity and had mutations in the ACVR1 geneother than the classical c.617G>A. All the above patients[1, 2] were in their second or third decade of life. We had asimilar experience when a child was referred to us forstaging of a suspected sarcoma. In addition to sheets ofcalcification in the paraspinal region on imaging, we notedshort broad femoral necks bilaterally with an osteochon-droma in the right femur neck and short and broad firstmetatarsal. Both great toes however were clinically andradiologically normal. A diagnosis of FOP was thenrendered based on the clinicoradiologic features; a mutationanalysis was however not performed.The report by Kartal-Kaess et al. [ 3]shouldthusbeinterpreted with the important caveat that although almost allpatients with FOP have great toe abnormalities, the diagnosiscan by no means be ruled out in patients with normal greattoes. These patients, particularly those presenting after thefirst decade, can have a FOP variant with milder clinicalcourse. In such patients, the diagnosis can be based on theclinical history and other characteristic-associated skeletalabnormalities, as seen in our patient. In equivocal cases, theDNA sequence analysis can provide confirmation, thusavoiding a potential missed diagnosis of FOP.

RAP-661 treatment, an ALK3 (BMPRIA) antagonist, decreases rankl and regulates osteoclastogenesis

RAP-661 treatment, an ALK3 (BMPRIA) antagonist, decreases rankl and regulates osteoclastogenesis

Report of two FOP cases with 617G>A mutation in the ACVR1 gene from Chinese population

Report of two FOP cases with 617G>A mutation in the ACVR1 gene from Chinese population

Genetic variation within the hypothalamus-pituitary-ovarian axis in women with recurrent miscarriage

Recurrent miscarriage affects 1-2% of couples trying to conceive, and is idiopathic in nearly half. Female fertility is controlled by the hypothalamus-pituitary-ovarian (HPO) axis and we hypothesize that genetic polymorphisms affecting the function of genes involved in regulating the HPO axis will be associated with recurrent miscarriage. Whole peripheral blood DNA from 227 women with recurrent miscarriage and 130 control women was obtained for this study. Using the Sequenom iPlex assay for fragment analysis, 31 single-nucleotide polymorphisms (SNPs) and 4 short tandem repeat (STR) polymorphisms in 20 candidate genes were evaluated for genetic association with recurrent miscarriage. Several candidate associations were identified with an uncorrected P-value of 0.05. Genotype distribution at an SNP (rs37389) in the prolactin receptor gene (P = 0.03), and allele distributions at an SNP (rs41423247) in the glucocorticoid receptor gene (P = 0.04) and an STR polymorphism in the estrogen receptor β gene (P = 0.03) were associated with recurrent miscarriage. The T allele of an SNP (rs2033962) within the activin receptor type 1 gene (ACVR1) was associated with increased number of miscarriages in an additive manner (P = 0.02). These candidate associations were not statistically significant after correcting for multiple analyses. Candidate associations were identified between recurrent miscarriage and genetic variation within ESR2, PRLR, GCCR and ACVR1 genes. Independent confirmation of these results is needed, as limitations of this study include the heterogeneous etiology of recurrent miscarriage, limited sample size, partial availability of reproductive history of the control group and investigation of only a subset of the genetic variation within each gene.

Fibrodysplasia ossificans progressiva (FOP): watch the great toes!

Fibrodysplasia ossificans progressiva (FOP) is a rare genetic disorder and the most disabling condition of heterotopic (extraskeletal) ossification in humans. Extraskeletal bone formation associated with inflammation preceding the osseous conversion usually begins in the first decade, predominantly in the head, neck, and shoulders. All patients have malformed great toes. Most patients have a spontaneous mutation of the ACVR1 gene. We report a 17-year-old girl with malformed great toes who had her first episode of heterotopic ossification and impaired mobility of the left hip at the age of 13years. No inflammatory fibroproliferative masses preceded the onset of heterotopic ossification. Radiographic studies demonstrated myositis ossificans, but failure to associate the great toe malformation with heterotopic ossification led to a failure to diagnose FOP. She underwent repeated and unnecessary operative procedures to remove a recurrent lesion. FOP was finally suspected when the great toe malformation was correlated with the trauma-induced heterotopic ossification. Genetic analysis confirmed the presence of the classic FOP mutation (ACVR1 c.617G>A; R206H). This case highlights the importance of examining the great toes in anyone with heterotopic ossification. The association of malformations of the great toe with heterotopic ossification in all cases of classic FOP will lead to prompt clinical diagnosis and the prevention of iatrogenic harm.

Mutational screening of ACVR1 gene in Brazilian fibrodysplasia ossificans progressiva patients

Fibrodysplasia ossificans progressiva (FOP) is a severe genetic disorder reported worldwide. A specific heterozygous mutation (c.617G> A; p.R206H) in the activin A type I receptor gene (ACVR1) is regarded as the genetic cause of FOP in all classically affected individuals worldwide. However, a few patients with FOP variants harbor distinct mutations in ACVR1. We screened a group of FOP Brazilian population for mutations in ACVR1. Of 16 patients with a classic FOP phenotype (10 males and 6 females, age range of 3-42 years), all had the classic mutation (p.R206H). One 21-year-old woman with a variant FOP phenotype had the previously reported c.983G> A mutation (p.G328E). Our study contributes to the understanding of the predominant FOP phenotype and genotype and suggests that variant FOP phenotypes are associated with specific mutations in ACVR1 gene.

Mutation Analysis and Prenatal Exclusion of Fibrodysplasia Ossificans Progressiva in a Chinese Fetus.

Aims: Fibrodysplasia ossificans progressiva (FOP) is a rare and severely disabling autosomal dominant disorder characterized by congenital malformations of the great toes and progressive postnatal heterotopic ossification. A point mutation in the activin receptor IA (ACVR1) gene is the cause of FOP. Most of the reported cases of FOP are sporadic and caused by de novo mutations; however, some rare cases can also result from parental germline mosaicism associated with a greater risk of recurrence in successive pregnancies. Therefore, once the pathogenic mutation has been identified in the proband, it is relative cheaper and important to perform prenatal diagnostic tests to exclude the recurrence risk of FOP in subsequent pregnancies. In this study, we first investigated the mutation in the ACVR1 gene in a Chinese FOP patient and then performed prenatal tests to exclude the risk of recurrence in the patient's unborn sibling. Methods: A couple visited our clinic with their 4-year-old son, who was clinically diagnosed with FOP, for genetic counseling. Genetic testing was performed by amplifying all the nine exons of the ACVR1 gene using the conventional polymerase chain reaction. Further, DNA sequencing was used to determine the mutation based on the results of a mutation screening using denaturing high-performance liquid chromatography. Subsequently, a prenatal test was performed using the same technique as that used for the proband. Results: A recurrent single nucleotide mutation c.617 G>A (R206H) of the ACVR1 gene was identified in the patient; however, both the parents had a normal ACVR1 gene. Prenatal tests showed that the fetus did not carry the pathogenic mutation. Conclusion: The results confirmed that a recurrent single nucleotide mutation c.617 G>A (R206H) was the genetic cause of FOP and explored the utility of prenatal testing in excluding the risk of recurrence in the successive pregnancy.

Rarely occurring mutation of ACVR1 gene in Moroccan patient with fibrodysplasia ossificans progressiva

Fibrodysplasia ossificans progressiva (FOP, MIM 135100) is a rare autosomal dominant disorder characterized by postnatal progressive heterotopic ossification of the connective tissue and congenital malformation of the big toes. Recently, FOP has been associated with a specific mutation of ACVR1, the gene coding for a bone morphogenetic protein type I receptor. We report the case of a Moroccan patient with FOP carrying a rarely occurring mutation of ACVR1 gene.

The effect of Smad4 siRNA on transforming growth factor-β-induced-PAI-1 expression

Objective The activation of transforming growth factor-β (TGF-β) has been implicated in liver fibrotic diseases by regulating plasminogen activator inhibitor (PAI-1) expression.This study aims at elucidating whether Smad4 small interference RNA (siRNA) can be used to suppress the TGF-β-induced PAI-1 in hepatic steUate cells (HSCs).Methods Smad4 siRNA was intreduced to HSCs by transient transfection for 24 h and stimulated by TGF-β (1 μg/L) for 24 or 48 h.The activities of Smad binding element (SBE) reporter was measured by a luciferase reporter assay.The expression of Smad4 protein was detected by immunoblot analysis.The expression of PAI-1 mRNA and protein was determined by Northern blot and immunoblot analysis,repsectively.Results Smad4 siRNA abrogated the Smad4 protein expression (3.0 ± 0.1 vs 16.0 ± 0.5).Smad4 siRNA inhibited both TGF-β1-and TGF-β type Ⅰ constitutively active receptor (ALK5) -induced 4 × SBE luciferase reporter activity, respectively.Smad4 siRNA inhibited TGF-β1-induced PAI-1 mRNA (1.3 ± 0.1 vs 6.5±0.2) and protein (1.50±0.15 vs 5.52 ± 0.36) expression.Conclusion These results indicate that Smad4 siRNA could provide a novel approach for therapeutic intervention to inhibit fibrotic liver diseases. Key words: Plasminogen activator inhibitor-1 ; RNA interference; Smad; Transforming growth factor-β

Novel Mutations in ACVR1 Result in Atypical Features in Two Fibrodysplasia Ossificans Progressiva Patients

Fibrodysplasia Ossificans Progressiva (FOP) is a rare, heritable condition typified by progression of extensive ossification within skeletal muscle, ligament and tendon together with defects in skeletal development. The condition is easily diagnosed by the presence of shortened great toes and there is severe advancement of disability with age. FOP has been shown to result from a point mutation (c.617G>A) in the ACVR1 gene in almost all patients reported. Very recently two other mutations have been described in three FOP patients. We present here evidence for two further unique mutations (c.605G>T and c.983G>A) in this gene in two FOP patients with some atypical digit abnormalities and other clinical features. The observation of disparate missense mutations mapped to the GS and kinase domains of the protein supports the disease model of mild kinase activation and provides a potential rationale for phenotypic variation.

A Recurrent Mutation c.617G>A in the ACVR1 Gene Causes Fibrodysplasia Ossificans Progressiva in Two Chinese Patients

Fibrodysplasia ossificans progressiva (FOP; OMIM 135100) is a rare heritable disorder of connective tissue characterized by congenital malformations of the great toes and recurrent episodes of painful soft tissue swelling that lead to heterotopic ossifications. Recent studies have shown that the ACVR1 (activin A receptor, type I; OMIM 102576) gene, which encodes the BMP type I receptor protein, is responsible for this disease. We observed two Chinese patients who suffered from progressive pain and ankylosis of major joints with congenital bilateral hallus valgus malformation, neck stiffness, and several posttraumatic ossified lesions on the head and dorsum. Both patients were diagnosed as having FOP. This study aimed to investigate the ACVR1 gene mutation in Chinese FOP patients. Direct sequence analysis of genomic DNA and restriction enzyme digestion demonstrated the presence of a single heterozygous c.617G>A (p.R206H) mutation in the ACVR1 gene in both patients. This mutation is first reported in Chinese patients with FOP and it was de novo in both affected families.

ACVR1 Gene Mutation in Sporadic Korean Patients with Fibrodysplasia Ossificans Progressiva

Fibrodysplasia ossificans progressiva (FOP; OMIM 135100) is a rare but extremely disabling genetic disorder of the skeletal system, and is characterized by the progressive development of ectopic ossification of skeletal muscles and subsequent joint ankylosis. The c.617G>A; p.R206H point mutation in the activin A type I receptor (ACVR1) gene has been reported to be a causative mutation of FOP. In the present study, mutation analysis of the ACVR1 gene was performed in 12 patients diagnosed or suspected to have FOP. All patients tested had a de novo heterozygous point mutation of c.617G>A; p.R206H in ACVR1. Mutation analysis confirmed a diagnosis of FOP in patients with ambiguous features, and thus, could be used for diagnostic purposes. Early confirmation through mutation analysis would allow medical professionals to advise on the avoidance of provoking events to delay catastrophic flare-ups of ectopic ossifications.

BMP type I receptor inhibition reduces heterotopic [corrected] ossification.

Fibrodysplasia ossificans progressiva (FOP) is a congenital disorder of progressive and widespread postnatal ossification of soft tissues and is without known effective treatments. Affected individuals harbor conserved mutations in the ACVR1 gene that are thought to cause constitutive activation of the bone morphogenetic protein (BMP) type I receptor, activin receptor-like kinase-2 (ALK2). Here we show that intramuscular expression in the mouse of an inducible transgene encoding constitutively active ALK2 (caALK2), resulting from a glutamine to aspartic acid change at amino acid position 207, leads to ectopic endochondral bone formation, joint fusion and functional impairment, thus phenocopying key aspects of human FOP. A selective inhibitor of BMP type I receptor kinases, LDN-193189 (ref. 6), inhibits activation of the BMP signaling effectors SMAD1, SMAD5 and SMAD8 in tissues expressing caALK2 induced by adenovirus specifying Cre (Ad.Cre). This treatment resulted in a reduction in ectopic ossification and functional impairment. In contrast to localized induction of caALK2 by Ad.Cre (which entails inflammation), global postnatal expression of caALK2 (induced without the use of Ad.Cre and thus without inflammation) does not lead to ectopic ossification. However, if in this context an inflammatory stimulus was provided with a control adenovirus, ectopic bone formation was induced. Like LDN-193189, corticosteroid inhibits ossification in Ad.Cre-injected mutant mice, suggesting caALK2 expression and an inflammatory milieu are both required for the development of ectopic ossification in this model. These results support the role of dysregulated ALK2 kinase activity in the pathogenesis of FOP and suggest that small molecule inhibition of BMP type I receptor activity may be useful in treating FOP and heterotopic ossification syndromes associated with excessive BMP signaling.