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.

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.

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.

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.

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.

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.

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.

Temporomandibular joint sound evaluation with an electronic device and clinical evaluation.

Sound analysis to diagnose internal derangement has received much attention as an alternative to radiographic examination. The purpose of this study was to compare findings with an electronic device (sonography) and clinical examination to magnetic resonance imaging (MRI) of the temporomandibular joint (TMJ). Twenty-three symptomatic patients (46 joints) were evaluated for this study. All patients had jaw joint pain and one or more of the following findings; limitation of jaw opening, painful mandibular movement with or without clicking or crepitation. The presence or absence of joint sounds was evaluated clinically by palpation and auscultation and with sonography. If sounds were present (clicking or crepitation) on either examination the patient was considered positive for disc displacement for that examination. Two by two tables were constructed comparing sonography and clinical examination with MRI findings. The sensitivity of the sonogram was 84% and the specificity was 33% when compared with MRI findings. The sensitivity of the clinical examination was 70% and the specificity was 40% when compared with MRI findings. This study suggests that clinical and sonographic examination has a high sensitivity (low false negative examinations) but low specificity (high false positive examinations).

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.

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.

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.

The effect of surgically induced anterior disc displacement of the temporomandibular joint on the midface and cranial base.

OBJECTIVE: The purpose of this study is to investigate the effect of unilateral TMJ disc displacement on the midface and cranial base. STUDY DESIGN: Thirteen 10-week-old rabbits, eight controls and five experimental were included in this study. The five experimental rabbits had surgically created unilateral disc displacement. Animals were sacrificed at 22 weeks and frontal, occlusal, and lateral oblique radiographs were made of the skulls. RESULTS: The occlusal radiograph demonstrated that the glenoid fossa on the experimental side was located more anterior. The oblique radiograph demonstrated the root of the zygomatic arch the experimental side was inferior. The anterior aspect of the fossa was more inferior on the frontal radiograph. CONCLUSIONS: A previous study suggested a shortening in the ramal height. This study suggests an alteration of the cranial articular fossa. Thus, it is suggested that disc displacement is capable of producing asymmetry in the developing mandible and cranial base.

Condyle position as a predictor of temporomandibular joint internal derangement.

STATEMENT OF PROBLEM: The significance of the position of the mandibular condyle in the glenoid fossa remains a controversial subject. PURPOSE: This study evaluated the relationship between condyle position and disk displacement. MATERIAL AND METHODS: Fifty-two asymptomatic volunteers and 130 symptomatic patients underwent linear tomography and bilateral temporomandibular joint magnetic resonance scans. RESULTS: There was a higher prevalence of distal condyles in symptomatic patients with disk displacement compared with asymptomatic volunteers (P <.05). Distally positioned condyles identified joints with disk displacement with reduction, disk displacement without reduction, or a symptomatic normal joint with a sensitivity of 0.64, 0.56, and 0.33, respectively. Distally positioned condyles identified joints with disk displacement with reduction, disk displacement without reduction, or a symptomatic normal joint with a specificity of 0.56, 0.65, and 0.55, respectively. CONCLUSION: There were more distal condyles in symptomatic subjects with disk displacement, but the reliability of a distal condyle to predict the presence or absence of disk displacement was low.

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.

Mandibular asymmetry in noncleft and unilateral cleft lip and palate individuals.

OBJECTIVE: The purpose of this study was to retrospectively investigate mandibular asymmetry in unilateral cleft lip and palate individuals (UCLP) in relation to chronologic age and in relation to lower facial asymmetry. DESIGN: The longitudinal records of 34 UCLP individuals and 142 controls treated in the Department of Orthodontics, Eastman Dental Center, Rochester, NY, were included in the study. Posteroanterior and oblique cephalometric radiographs were analyzed for lower facial asymmetry and mandibular asymmetry, respectively. Mandibular asymmetry in UCLP was analyzed relative to three age groups (6-10, 11-14, and 15 or greater) and compared to controls. Moreover, mandibular asymmetry was analyzed relative to lower facial asymmetry. RESULTS: UCLP individuals showed no significant differences in mandibular asymmetry compared to controls. In addition, no significant correlation was found between mandibular asymmetry and lower facial asymmetry in UCLP. CONCLUSIONS: The degree of mandibular asymmetry in UCLP appears not to be the major contributing factor to the lower facial asymmetry noted on these individuals. Possible cranial-base/temporal-region anomalies may be involved in unilateral cleft lip and palate and be responsible of the asymmetry noted in the lower facial skeleton.

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.

Mandibular and maxillary asymmetry in individuals with unilateral cleft lip and palate.

OBJECTIVE: This study was conducted to evaluate the degree of maxillary and mandibular asymmetry in the verticle and transverse planes seen in posteroanterior cephalometric radiographs relative to chronologic age in postoperative complete UCLP patients compared to controls. METHOD: Mandibular and nasomaxillary asymmetry was retrospectively studied in complete unilateral cleft lip and palate (UCLP) and noncleft individuals (controls) by means of posteroanterior cephalometric analysis. All the UCLP patients available (total 40) and randomly selected noncleft controls (total 142) were included in the study. The UCLP patients had undergone lip and palate reconstruction in Strong Memorial Hospital, University of Rochester, Rochester, New York, and orthodontic treatment in the Department of Orthodontics, Eastman Dental Center, Rochester, New York. The controls were selected based on the age that treatment was initiated and were treated in the department for various malocclusions; none had undergone maxillary expansion or surgical treatment. The asymmetry assessed on mixed longitudinal records of the patients with UCLP was analyzed relative to three chronologic age groups and compared to the controls. In addition, mandibular asymmetry was correlated to maxillary asymmetry in UCLP individuals to investigate possible growth patterns between the two jaws. RESULTS: Mandibular asymmetry in UCLP individuals was found to increase with growth and time and peaked at post-pubertal growth-spurt stages. The cleft subjects were more asymmetric than controls in all stages of growth. Mandibular asymmetry followed the affected maxilla closely, indicating a parallel growth pattern of the jaws. CONCLUSION: The unilateral cleft lip and palate patients manifested asymmetry of the mandible. This asymmetry develops in a parallel pattern with the affected maxilla, suggesting that early evaluation and treatment of the anomalies in the nasomaxillary skeleton as well as in the mandible is necessary when treating unilateral cleft lip and palate individuals.

ICAM-1 induction in the mouse CNS following irradiation.

Injury to the central nervous system (CNS) results in inflammation, increased trafficking of leukocytes into the CNS, induction of cytokines, and exacerbation of the primary injury. The increased trafficking of neutrophils into the CNS has been described following a number of injury models including stab, stroke, and excitotoxin-induced injury. This enhanced trafficking has largely been ascribed to the adhesion molecule intercellular adhesion molecule-1 (ICAM-1, CD54). In the current study, we wished to determine if the inflammation caused by irradiation of the CNS resulted in a similar induction of ICAM-1. C3H/HeJ mice were irradiated using gamma irradiation aimed over the right cerebral hemisphere. The relative induction of ICAM-1 mRNA levels was determined using quantitative RT-PCR 6 hours following irradiation with either 0, 5, 15, 25 or 35 Gy. ICAM-1 message was seen to exhibit a normal dose response curve with increasing mRNA levels seen at 15 Gy and higher. To determine the cellular distribution of the ICAM-1 protein following irradiation, mice were sacrificed at 4 hrs, 24 hrs, 48 hrs and 7 days following 25 Gy irradiation and the tissue was processed for ICAM-1 immunocytochemistry. ICAM-1 staining was seen to increase in both endothelial cells and astrocytes beginning as early as 4 hrs. The staining intensity continued to increase throughout the 7 day period observed. Together, these results suggest that irradiation of the CNS causes a rapid induction of both ICAM-1 mRNA and protein. This suggests that increased leukocyte trafficking into the CNS may exacerbate the inflammation induced by radiation injury.

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.