Modulation of RTK by sEcad: a putative mechanism for oncogenicity in oropharyngeal SCCs.

OBJECTIVE: Heightened levels of sEcad are found in the serum of patients with cancer and correlate with an unfavorable prognosis and later-stages of disease. In this study, we explored whether sEcad is elevated in human OPSCC specimens and FaDu cells. Additionally, we investigated sEcad-EGFR and sEcad-IGF-1R interactions and performed a functional analysis of sEcad in OPSCC cancers. MATERIALS AND METHODS: sEcad, EGFR, and IGF-1R levels were examined in human OPSCC specimens and cells by immunoblotting. sEcad-EGFR and sEcad-IGF-1R interactions were examined by immunoprecipitation and immunoblot assays. Levels of sEcad on EGFR and IGF-1R pathway components were evaluated by IB. The effects of sEcad on OPSCC proliferation, migration, and invasion were assessed using standard cellular assays. RESULTS: Statistical analysis demonstrated that sEcad levels were significantly higher in OPSCC primary tumors and cells compared with normal controls. IP studies indicated that sEcad associated with EGFR and IGF-1R, and addition of sEcad resulted in a statistically significant increase in downstream signaling. Finally, cell-based assays demonstrated enhanced sEcad-induced proliferation, migration, and invasion, which was blocked by EGFR and IGF-1R inhibitors. CONCLUSIONS: These findings suggest that sEcad may play an important role in OPSCC oncogenicity via its interaction and activation of EGFR and IGF-1R.

Nerve growth factor induced after temporomandibular joint inflammation decelerates chondrocyte differentiation.

OBJECTIVE: The goal of this study was to investigate changes in nerve growth factor (NGF) and its high-affinity receptor-tropomyosin receptor kinase A (TrkA) expression in the TMJ after intra-articular inflammation. MATERIALS AND METHODS: We employed the Col1-IL1ß(XAT) inducible model of joint inflammation. Changes in NGF and TrkA expression were evaluated by immunohistochemistry. The function of NGF on cell differentiation was assessed in vitro employing the ATDC5 chondrocyte cell line. RESULTS: NGF expression was observed in articular chondrocytes only after TMJ inflammation, whereas TrkA expression was detected in articular chondrocytes under both naïve as well as inflamed conditions. The potential effect of NGF on articular chondrocytes was studied on the ATDC5 cell line, whereby NGF decelerated the maturation rate of this chondrogenic cell line, presumably by arresting cell differentiation at the prehypertrophic stage of chondrocyte maturation. CONCLUSIONS: NGF-TrkA signaling in the TMJ provides potentially a means of protection against the development of osteoarthritis by decelerating chondrocyte differentiation. This discovery may lead to the development of novel therapies for osteoarthritis of the TMJ and other joints.

The cranial base in craniofacial development: a gene therapy study.

The etiology of midface retrusion remains largely unclear. We hypothesized that the cranial base synchondroses play a key role in the development of the craniofacial skeleton in the Sandhoff mouse model. We observed that developmental abnormalities of the cranial base synchondroses involving proliferative chondrocytes are important in craniofacial growth and development. Neonatal restitution of beta-hexosaminidase in mutant mice by gene therapy successfully ameliorated the attendant skeletal defects and restored craniofacial morphology in vivo, suggesting this as a critical temporal window in craniofacial development. Analysis of our data implicates parathyroid-related peptide (PTHrP) and cyclo-oxygenase-2 (COX-2) as possible factors underlying the development of the aforementioned skeletal defects. Hence, timely restitution of a genetic deficiency or, alternatively, the restoration of PTHrP or cyclo-oxygenase activity by the administration of PTH and/or non-steroidal anti-inflammatory drugs or COX-2 selective inhibitors to affected individuals may prove beneficial in the management of midface retrusion.

Enhanced glial activation and expression of specific CNS inflammation-related molecules in aged versus young rats following cortical stab injury.

Aging is associated with increased glial responsiveness that may enhance the brain's susceptibility to injury and disease. To determine whether unique age-related molecular responses occur in brain injury, we assessed mRNA levels of representative central nervous system (CNS) inflammation-related molecules in young (3 months) and aged (36 months) Fisher 344/Brown Norwegian F1 hybrid rats following cortical stab. Enhanced glial activation in older animals was accompanied by increased expression of a subset of inflammation-related mRNAs, including IL-1beta, TNFalpha, IL-6, ICAM-1, inducible nitric oxide synthase (iNOS), metalloproteinase-9 (MMP-9), and complement 3alpha-chain 1 (C3alpha1). Recognition of these age-specific differences may guide development of novel treatment regimes for older individuals.

TNF alpha and IL-1beta mediate intercellular adhesion molecule-1 induction via microglia-astrocyte interaction in CNS radiation injury.

Radiation injury to the central nervous system (CNS) results in glial activation accompanied by expression of pro-inflammatory cytokines and adhesion molecules. In this study we demonstrate intercellular adhesion molecule-1 (ICAM-1) induction in the irradiated mouse brain at the mRNA and protein levels. Immunocytochemical analysis revealed that ICAM-1 protein was primarily expressed in endothelial cells and microglia. In vitro, ionizing radiation significantly induces TNF alpha, IL-1beta and ICAM-1 mRNA in primary microglia cultures. Interestingly, although ionizing radiation activated primary astrocyte cultures, it did not induce ICAM-1 expression. However, exposure of astrocytes to conditioned medium collected from irradiated microglia resulted in ICAM-1 induction, which was abrogated when the conditioned medium was pre-incubated with neutralizing antibodies raised against murine TNF alpha and IL-1beta. These results indicate that pro-inflammatory cytokines may be necessary for ICAM-1 expression in astrocytes in CNS radiation injury.

Non-primate lentiviral vector administration in the TMJ.

Gene therapy is emerging as a novel treatment method for the management of temporomandibular joint disorders. The aim of this investigation was to study the effects of lentiviral vectors on the temporomandibular joint. Consequently, we injected into the articular joint space a defective feline immunodeficiency virus capable of infecting dividing as well as terminally differentiated cells with the reporter gene lacZ, the expression of which was studied by means of PCR, X-gal histochemistry, and beta-galactosidase immunocytochemistry. Our results showed successful transduction of hard and soft tissues of the temporomandibular joint. Interestingly, a subset of primary sensory neurons of the ipsilateral trigeminal ganglion also stained positive for the reporter gene, presumably following uptake of the lentiviral vector by peripheral nerve fibers and retrograde transport to the nucleus. These findings suggest that lentiviral vectors can potentially serve as a platform for the transfer of anti-nociceptive genes for the management of temporomandibular joint pain.

Generalized joint laxity and temporomandibular disorders.

Temporomandibular disorders (TMD) has been suggested to be of multifactorial etiology. One factor that has been suggested is laxity of joint ligaments. The purpose of this study was to evaluate the relationship between generalized joint hypermobility and TMD. Thirty-eight asymptomatic volunteers and 62 symptomatic patients were included in this study. All asymptomatic volunteers did not have temporomandibular joint pain, limited jaw movement, joint sounds, or previous TMD treatment. All subjects had bilateral magnetic resonance imaging scans in the sagittal closed and opened and coronal closed positions. The Beighton test was used to score joint laxity with a laxity score of > or = 4 to define generalized joint laxity. The symptomatic group had an increase in joint laxity as compared to asymptomatic control subjects (odds ratio 4.0 [95% confidence interval = 1.38 to 10.95, P = .01]). There were no differences in laxity between male and female symptomatic subjects (P > .05). This study suggests a positive correlation between generalized joint laxity and TMD.

Effect of a surgically created disk displacement on mandibular symmetry in the growing rabbit.

PURPOSE: The purpose of this study was to evaluate the contribution of unilateral disk displacement to growth changes in the young New Zealand White rabbit. METHODS: Ten female rabbits aged 10 weeks were included in this study. The five experimental rabbits had unilateral anterior disk displacement surgery. The five controls had no surgery. The rabbits were killed at 22 weeks of age, and the mandibles hemisected and radiographed. Cephalograms were digitized and analyzed by conventional methods. RESULTS: The gross appearance showed shortening and flattening of the articulating surface in the experimental group (P < 0.05). No significant shortening and flattening was found in the control group. CONCLUSION: These observations suggest that surgically created internal derangement can produce altered growth in the mandible.

Melnick-Needles syndrome in a mother and her son.

The Melnick-Needles syndrome is a rare connective tissue disorder characterised by specific facial features (small facial bones, exophthalmos, hypertelorism, full checks and small mandible), skeletal defects and short stature. The syndrome is considered to be lethal in males. Nevertheless, five surviving males are considered to represent new mutations. We are presenting an affected surviving male with the Melnick-Needles syndrome born to an affected mother.

Familial bilateral blepharoptosis and subvalvular aortic stenosis.

A boy and his mother with bilateral congenital blepharoptosis, downslanting palpebral fissures, hypertelorism, microcephaly, short nose with flattened nasal root, microstomia, prominent lateral palatine ridges, bifid (boy) hypoplastic (mother) uvula, generalized dental caries, short neck, peculiar voice and mild conductive deafness are reported. The boy had subvalvular aortic stenosis. The mother had pectus excavatum but not any signs or symptoms of cardiovascular defect.

Growth retardation, distinct oriental-like facies, glaucoma, brachydactyly, ventricular septal defect and speech disorder. An unknown entity.

A caucasian boy with distinct oriental-like facies, short stature, brachydactyly, congenital ventricular septal defect, glaucoma, and speech disorder is reported. Routine laboratory tests, karyotype, and hormonal profile (IGF 1, growth hormone during provocative testing, thyroid hormones, prolactin, gonadotrophins) were normal. Radiologic skeletal survey did not disclose any abnormality. Both parents were apparently normal, but short in stature.

Hyperbrachycephaly, short face, midface hypoplasia, fusion of cervical vertebrae, radiolucent bone defects, and severe destruction of periodontium--a new syndrome: craniofaciocervical osteoglyphic dysplasia.

A patient with an unusual combination of findings, which do not fit in any of the known syndromes, is presented. The patient, a 24.5-year-old male of normal growth and intelligence, manifests craniofacial dysmorphism, radiolucencies in the skull and in the cervical vertebrae, progressive alveolar bone loss and fusion of cervical vertebrae. The young man does not exhibit any other systemic, hematological, biochemical, chromosomal or immunological abnormality, except for IgA deficiency.

Soluble E-cadherin: a critical oncogene modulating receptor tyrosine kinases, MAPK and PI3K/Akt/mTOR signaling.

E-cadherin, a cell-cell adhesion glycoprotein, is frequently downregulated with tumorigenic progression. The extracellular domain of E-cadherin is cleaved by proteases to generate a soluble ectodomain fragment, termed sEcad, which is elevated in the urine or serum of cancer patients. In this study, we explored the functional role of sEcad in the progression of skin squamous cell carcinomas (SCCs). We found that full-length E-cadherin expression was decreased and sEcad increased in human clinical tumor samples as well as in ultraviolet (UV)-induced SCCs in mice. Interestingly, sEcad associated with members of the human epidermal growth factor receptor (HER) and insulin-like growth factor-1 (IGF-1R) family of receptors in human and UV-induced mouse tumors. Moreover, in both E-cadherin-positive (E-cadherin(+)) and -negative (E-cadherin(-)) cells in vitro, sEcad activated downstream mitogen-activated protein (MAP) kinase (MAPK) and phosphatidylinositol 3-kinase (PI3K)/Akt/mammalian target of rapamycin (mTOR) signaling and enhanced tumor growth, motility and invasion, the latter via activation of matrix metalloproteinase-2 (MMP-2) and MMP-9. To this end, HER, PI3K or MEK inhibitors suppressed sEcad's tumorigenic effects, including proliferation, migration and invasion. Taken together, our data suggest that sEcad contributes to skin carcinogenesis via association with the HER/IGF-1R-family of receptors and subsequent activation of the MAPK and PI3K/Akt/mTOR pathways, thereby implicating sEcad as a putative therapeutic target in cutaneous SCCs.

IL-1beta inhibits TGFbeta in the temporomandibular joint.

Similarly to humans, healthy, wild-type mice develop osteoarthritis, including of the temporomandibular joint (TMJ), as a result of aging. Pro-inflammatory cytokines, such as IL-1beta, IL-6, and TNFalpha, are known to contribute to the development of osteoarthritis, whereas TGFbeta has been associated with articular regeneration. We hypothesized that a balance between IL-1beta and TGFbeta underlies the development of TMJ osteoarthritis, whereby IL-1beta signaling down-regulates TGFbeta expression as part of disease pathology. Our studies in wild-type mice, as well as the Col1-IL1beta(XAT) mouse model of osteoarthritis, demonstrated an inverse correlation between IL-1beta and TGFbeta expression in the TMJ. IL-1beta etiologically correlated with joint pathology, whereas TGFbeta expression associated with IL-1beta down-regulation and improvement of articular pathology. Better understanding of the underlying inflammatory processes during disease will potentially enable us to harness inflammation for orofacial tissue regeneration.

Cephalometric analysis of Rapp-Hodgkin syndrome.

Rapp-Hodgkin syndrome (RHS) is a rare form of ectodermal dysplasia with variable involvement of the hair, eyes, sweat glands, nails, and teeth. Oral findings may include hypodontia, hypoplastic enamel, cleft lip/palate, and a pronounced midfacial hypoplasia. The objective of this study was to determine if the pronounced midfacial hypoplasia is the result of a true tissue hypoplasia or displacement of midfacial tissues. We have identified a family in which three members, a mother and two daughters, display clinical features characteristic of RHS. Clinical and intraoral examination of these affected persons showed manifestations characteristic of RHS, and several new findings were observed, including subcutaneous abscesses, palmoplantar keratosis, and keratotic lesions located on the chest and trunk. To assess the midfacial hypoplasia, lateral cephalometric analysis was performed on lateral headplates. Results of the cephalometric analysis suggest that the midfacial hypoplasia results from both a deficiency and a displacement of the maxilla. These findings are significant because successful dental treatment of RHS relies upon accurate assessment of current and projected orofacial development, particularly for the skeletal relations of the maxilla and mandible.

Cranial base and facial skeleton asymmetries in individuals with unilateral cleft lip and palate.

OBJECTIVE: Individuals with unilateral cleft lip and palate (UCLP) manifest a plethora of phenotypic characteristics, including asymmetric development of the middle and lower facial skeleton. The purpose of this study was to retrospectively investigate the development of cranial base asymmetries in patients with UCLP noted on posteroanterior cephalometric radiographs. METHODS: Thirty individuals with UCLP and 64 controls participated in this study. Medial and lateral cranial base asymmetries were analyzed on frontal cephalometric radiographs relative to three developmental stages. Furthermore, the development of horizontal and vertical lower facial asymmetry in these patients with UCLP was assessed in relation to cranial base, nasomaxillary, and dentoalveolar structures. RESULTS: Individuals with UCLP demonstrated cranial base asymmetries that did not significantly differ from individuals without cleft. In addition, lower facial asymmetry in patients with UCLP correlated with horizontal lower facial and dentoalveolar asymmetries but not with cranial base or nasomaxillary structures. CONCLUSIONS: No significant vertical cranial base asymmetries were detected in patients with UCLP. Horizontal lower facial asymmetry appeared to develop in close relation to the vertical asymmetries of mandibular fossae and dentoalveolus.

Skeletal asymmetries of the nasomaxillary complex in noncleft and postsurgical unilateral cleft lip and palate individuals.

Asymmetries in the nasomaxillary skeleton are very common in individuals with unilateral cleft lip and palate. The purpose of this study was to retrospectively evaluate postsurgical asymmetries of the nasomaxillary skeleton in unilateral cleft lip and palate patients. Included in this study were 36 complete cleft lip and palate subjects, along with 36 noncleft (control) subjects. Skeletal asymmetry, deviations of the anterior nasal spine, and the premaxillary area were compared by chronologic age and skeletal maturation in cleft subjects and controls. Comparison between cleft and control cases was assessed. Results indicated that skeletal asymmetry in unilateral clefts and controls peaks during the pubertal growth spurt. The anterior nasal spine and nasal septum always tend to deviate toward the noncleft side of the nasal cavity, although individual variation exists. Cleft subjects were found to be more asymmetric than noncleft subjects to a statistically significant degree.

Asymmetries of the upper lip and nose in noncleft and postsurgical unilateral cleft lip and palate individuals.

The purpose of this study was to retrospectively evaluate post-surgical asymmetries of the upper lip and nose in complete unilateral cleft lip and palate individuals using documentation collected over a period of years. Twenty-three complete unilateral cleft lip and palate subjects (UCLP) and 34 noncleft subjects who served as controls and had undergone orthodontic treatment were included in the study. Nasal asymmetry, deviation of the tip of the nose, and the deviation of the midpoint of the vermilion border of the upper lip were compared to chronologic age and skeletal maturation in cleft subjects and controls. Comparison between cleft and control cases was also assessed. Results indicate that nasal asymmetry peaks at postpubertal growth stages in the control groups, and the difference between UCLP and controls decreases with time and maturation. The deviation of the nasal tip peaks during the pubertal growth spurt for both UCLP and controls, and the difference between UCLP and controls also decreases with time. The deviation of the midpoint of the vermilion border shows relatively small change with time and maturation, and there is no significant difference between UCLP and controls. In general, the facial asymmetries studied were not as great as expected, and the difference between UCLP and controls decreased with time, growth, and maturation.

Nonsteroidal anti-inflammatory drugs in orthodontic tooth movement: metalloproteinase activity and collagen synthesis by endothelial cells.

Orthodontic treatment is based on the biologic principle that prolonged pressure on teeth results in remodeling of periodontal structures, allowing for tooth movement. Periodontal remodeling is a complex process regulated in part by prostaglandins and adversely affected by the use of nonsteroidal anti-inflammatory drugs. We investigated the effects of indomethacin on collagenase activity and procollagen synthesis in rat endothelial cell cultures. Cyclooxygenase inhibition resulted in exacerbation of IL-1 beta-mediated collagenase B (MMP-9) production and activity, as well as attenuation of type IV procollagen synthesis levels by endothelial cells in vitro. Hence, the use of over-the-counter nonsteroidal anti-inflammatory drugs during tooth movement may result in aberrant remodeling of periodontal vasculature and other structures, ultimately affecting orthodontic treatment efficacy. Further studies are needed to establish novel pain relievers that do not interfere with orthodontic processes.