Ritu Duggal

Heterogeneous ribonucleoprotein K is a marker of oral leukoplakia and correlates with poor prognosis of squamous cell carcinoma

Oral leukoplakia is a heterogeneous lesion with risk of cancer development; there are no biomarkers to predict its potential of malignant transformation. Tissue proteomic analysis of oral leukoplakia using iTRAQ labeling liquid chromatography–mass spectrometry showed overexpression of heterogeneous ribonucleoprotein K (hnRNP K), a transformation‐related RNA‐binding protein, in leukoplakia in comparison with normal tissue. Herein, we investigated the clinical significance of hnRNP K in identification of oral leukoplakic lesions in early stages and as a prognostic marker in head‐and‐neck/oral squamous cell carcinomas (HNOSCCs). Immunohistochemical analysis of hnRNP K was performed in 100 HNOSCCs, 199 leukoplakias and 55 nonmalignant tissues and correlated with clinicopathologic parameters and disease prognosis over 6 years for HNOSCCs. hnRNP K nuclear expression increased from normal tissues to leukoplakia, and frank malignancy (p < 0.001). Cytoplasmic hnRNP K increased significantly from leukoplakia to HNOSCCs (p < 0.001) and was associated with poor prognosis of HNOSCCs (p = 0.011) by Kaplan–Meier analysis. The most important finding of our follow‐up study is that cytoplasmic hnRNP K is an independent predictor of disease recurrence in HNOSCC patients. In conclusion, nuclear hnRNP K may serve as a potential marker for early diagnosis, whereas its cytoplasmic accumulation can help to identify a subgroup of HNOSCC patients with poor prognosis, suggesting its putative utility in clinical management of HNOSCC.

Nuclear S100A7 Is Associated with Poor Prognosis in Head and Neck Cancer

Background Tissue proteomic analysis of head and neck squamous cell carcinoma (HNSCC) and normal oral mucosa using iTRAQ (isobaric tag for relative and absolute quantitation) labeling and liquid chromatography-mass spectrometry, led to the identification of a panel of biomarkers including S100A7. In the multi-step process of head and neck tumorigenesis, the presence of dysplastic areas in the epithelium is proposed to be associated with a likely progression to cancer; however there are no established biomarkers to predict their potential of malignant transformation. This study aimed to determine the clinical significance of S100A7 overexpression in HNSCC. Methodology Immunohistochemical analysis of S100A7 expression in HNSCC (100 cases), oral lesions (166 cases) and 100 histologically normal tissues was carried out and correlated with clinicopathological parameters and disease prognosis over 7 years for HNSCC patients. Overexpression of S100A7 protein was significant in oral lesions (squamous cell hyperplasia/dysplasia) and sustained in HNSCC in comparison with oral normal mucosa (ptrend<0.001). Significant increase in nuclear S100A7 was observed in HNSCC as compared to dysplastic lesions (p = 0.005) and associated with well differentiated squamous cell carcinoma (p = 0.031). Notably, nuclear accumulation of S100A7 also emerged as an independent predictor of reduced disease free survival (p = 0.006, Hazard ratio (HR = 7.6), 95% CI = 1.3−5.1) in multivariate analysis underscoring its relevance as a poor prognosticator of HNSCC patients. Conclusions Our study demonstrated nuclear accumulation of S100A7 may serve as predictor of poor prognosis in HNSCC patients. Further, increased nuclear accumulation of S100A7 in HNSCC as compared to dysplastic lesions warrants a large-scale longitudinal study of patients with dysplasia to evaluate its potential as a determinant of increased risk of transformation of oral premalignant lesions.

Over-expression of 14-3-3zeta is an early event in oral cancer

BackgroundThe functional and clinical significance of 14-3-3 proteins in human cancers remain largely undetermined. Earlier, we have reported differential expression of 14-3-3ζ mRNA in oral squamous cell carcinoma (OSCC) by differential display.MethodsThe clinical relevance of 14-3-3ζ protein in oral tumorigenesis was determined by immunohistochemistry in paraffin embedded sections of oral pre-malignant lesions (OPLs), OSCCs and histologically normal oral tissues and corroborated by Western Blotting. Co-immunoprecipitation assays were carried out to determine its association with NFκB, β-catenin and Bcl-2.ResultsIntense immunostaining of 14-3-3ζ protein was observed in 61/89 (69%) OPLs and 95/120 (79%) OSCCs. Immunohistochemistry showed significant increase in expression of 14-3-3ζ protein from normal mucosa to OPLs to OSCCs (ptrend < 0.001). Significant increase in expression of 14-3-3ζ protein was observed as early as in hyperplasia (p = 0.009), with further elevation in moderate and severe dysplasia, that was sustained in OSCCs. These findings were validated by Western blotting. Using Co-immunoprecipitation, we demonstrated that 14-3-3ζ protein binds to NFκB, β-catenin and Bcl-2, suggesting its involvement in cellular signaling, leading to proliferation of oral cancer cells.ConclusionOur findings suggest that over-expression of 14-3-3ζ is an early event in oral tumorigenesis and may have an important role in its development and progression. Thus, 14-3-3ζ may serve as an important molecular target for designing novel therapy for oral cancer.

Muscle response to the Twin-block appliance: An electromyographic study of the masseter and anterior temporal muscles

An electromyographic study was performed on 10 young growing girls in the age group of 9 to 12 years with Class II Division 1 malocclusion and retruded mandible, who were under treatment with Twin-block appliances. Bilateral EMG activity of elevator muscles of the mandible (ie, anterior temporalis and masseter) was monitored longitudinally with bipolar surface electrodes to determine changes in postural, swallowing, and maximal voluntary clenching activity during an observation period of 6 months. The changes were noted at the start of treatment (0 month), within 1 month of Twin-block insertion, at the end of 3 months, and at the end of 6 months. The results revealed a significant increase in postural and maximal clenching EMG activity in masseter (P <.01) and a numeric increase in anterior temporalis activity during the 6 month period of treatment. The increased electromyographic activity can be attributed to an enhanced stretch (myotatic) reflex of the elevator muscles, contributing to isometric contractions. The main force for Twin-block treatment appears to be provided through increased active tension in the stretched muscles (motor unit stimulation) and from initiation of myotatic reflex activity and not through passive tension (viscoelastic properties) of jaw muscles. The results of this study reaffirm the importance of full-time wear for functional appliances to exert their maximum therapeutic effect by way of neuromuscular adaptation.

Treatment Effects of Twin-Block and Mandibular Protraction Appliance-IV in the Correction of Class II Malocclusion

OBJECTIVE To evaluate the treatment effects of twin-block and Mandibular Protraction Appliance-IV (MPA-IV) in the treatment of Class II division 1 malocclusion. METHODS Fifty North Indian girls with Class II division 1 malocclusion, in the age range of 9-13 years, were chosen. The subjects were divided among a control group (n = 10), a twin-block group (n = 25), and an MPA group (n = 15). Pre-follow-up and post-follow-up lateral cephalograms of control subjects and pretreatment and posttreatment lateral cephalograms of the treatment subjects were traced manually and subjected to a pitchfork analysis. RESULTS Neither twin-block nor MPA-IV significantly restricted the forward growth of maxilla. Mandibular growth and improvement in the sagittal skeletal relation were significantly greater in the twin-block subjects. Distal movement of the maxillary dentition and mesial movement of the mandibular dentition were more prominent in the MPA-IV subjects. Molar correction and overjet reductions were significantly greater in the treatment subjects (P < .001). CONCLUSION Twin-block and MPA-IV were effective in correcting the molar relationships and reducing the overjet in Class II division 1 malocclusion subjects. However, twin-block contributed more skeletal effects than MPA-IV for the correction of Class II malocclusion.

Overexpression of Prothymosin Alpha Predicts Poor Disease Outcome in Head and Neck Cancer

Background In our recent study, tissue proteomic analysis of oral pre-malignant lesions (OPLs) and normal oral mucosa led to the identification of a panel of biomarkers, including prothymosin alpha (PTMA), to distinguish OPLs from histologically normal oral tissues. This study aimed to determine the clinical significance of PTMA overexpression in oral squamous cell hyperplasia, dysplasia and head and neck squamous cell carcinoma (HNSCC). Methodology Immunohistochemistry of PTMA protein was performed in HNSCCs (n = 100), squamous cell hyperplasia (n = 116), dysplasia (n = 50) and histologically normal oral tissues (n = 100). Statistical analysis was carried out to determine the association of PTMA overexpression with clinicopathological parameters and disease prognosis over 7 years for HNSCC patients. Results Our immunohistochemical analysis demonstrated significant overexpression of nuclear PTMA in squamous cell hyperplasia (63.8%), dysplasia (50%) and HNSCC (61%) in comparison with oral normal mucosa (ptrend<0.001). Chi-square analysis showed significant association of nuclear PTMA with advanced tumor stages (III+IV). Kaplan Meier survival analysis indicated reduced disease free survival (DFS) in HNSCC patients (p<0.001; median survival 11 months). Notably, Cox-multivariate analysis revealed nuclear PTMA as an independent predictor of poor prognosis of HNSCC patients (p<0.001, Hazards ratio, HR = 5.2, 95% CI = 2.3–11.8) in comparison with the histological grade, T-stage, nodal status and tumor stage. Conclusions Nuclear PTMA may serve as prognostic marker in HNSCC to determine the subset of patients that are likely to show recurrence of the disease.

Temporomandibular joint adaptations following two‐phase therapy: an MRI study

AIM To document the alterations within the condyle-glenoid fossa (C-GF) complex and the positional changes of the glenoid fossa in the cranium after removable functional appliance therapy and after the completion of fixed appliance therapy. SETTING AND SAMPLE The Department of Orthodontics, Centre for Dental Education and Research, All India Institute of Medical Sciences, New Delhi, India. The study sample consisted of 12 growing children (eight girls and four boys) between 10 and 14 years of age with skeletal Class II division 1 malocclusion selected on well defined criteria. MATERIALS AND METHODS All patients were treated with either the Twin Block or the Bionator appliance followed by fixed appliances. Mean total treatment duration was 28 months. The changes in and around the C-GF complex were evaluated using MRI at pre-treatment stage, after functional appliance therapy and at the completion of fixed mechanotherapy. RESULTS Forward condylar position within the glenoid fossa and articular disc retrusion with respect to the condylar head were statistically significant after functional appliance therapy. However, the condyles had a relatively concentric position within the glenoid fossa, while the articular disc resumed its pre-treatment position at the end of the treatment. Linear measurements from the centre of the external auditory meatus to the post-glenoid spine revealed a 1.3-mm forward relocation of the post-glenoid spine along the Frankfurt Horizontal plane. CONCLUSIONS Forward relocation of the C-GF complex seems to be one of the mechanisms of action of functional appliances, while the internal anatomic arrangement within the temporomandibular joint (TMJ) complex normalizes to its pre-treatment position.

Loss of DLC1 is an independent prognostic factor in patients with oral squamous cell carcinoma

Deleted in liver cancer (DLC1), a Rho GTPase-activating protein, was observed to be differentially expressed in oral squamous cell carcinoma in comparison with normal tissues using tissue proteomics. In the current study, we investigated the clinical significance of loss of DLC1 expression in different stages of development of oral squamous cell carcinoma to determine its potential as a biomarker for oral dysplasia and prognosis of oral squamous cell carcinoma. Immunohistochemical analysis of DLC1 expression was carried out in oral squamous cell carcinoma patients (n=214), dysplasia (n=51), hyperplastic squamous mucosa (n=45), and histologically normal oral tissues (n=80), and correlated with clinicopathological parameters and disease prognosis over 91 months for oral squamous cell carcinomas. Loss of DLC1 expression was observed in oral squamous cell carcinoma (64%), oral dysplasia (31%), hyperplastic squamous mucosa (22%), and normal mucosa (16%). Significant loss of DLC1 expression was observed in oral squamous cell carcinomas as compared with dysplasia (P<0.001, odds ratio=3.8, 95% CI=2.0–7.3), suggesting it may be an important event involved in cancer progression. Among oral squamous cell carcinomas, the loss of DLC1 expression was significantly associated with poor prognosis (P=0.021, hazards ratio (HR)=1.8, 95% CI=1.1–2.9). Multivariate analysis revealed loss of DLC1 (P=0.023, HR=2.1, 95% CI=1.2–3.9) and histopathological grade (P=0.015, HR=1.7, 95% CI=1.1–2.7) to be independent predictors for disease-free survival in oral squamous cell carcinoma patients in comparison with known prognostic factors, viz. tumor stage, nodal status, and overall stage. Loss of DLC1 expression emerged as an important biomarker for predicting patients diagnosed with oral dysplasia at high risk of transformation upon future validation in longitudinal studies. Loss of DLC1 expression is a poor prognostic marker for oral squamous cell carcinoma patients.

Hyoid bone position in subjects with different vertical jaw dysplasias.

OBJECTIVE To test the hypothesis that there is no difference in hyoid bone position among subjects with different vertical jaw dysplasias. MATERIALS AND METHODS Seventy-one North Indian adult male and female subjects in the age range of 15 to 25 years were selected for the study. Based on the vertical growth pattern of the face, subjects were divided into Group I (n = 24; subjects in whom both Frankfort mandibular plane angle [FMA] and basal plane angle measured 20 to 25 degrees), Group II (n = 17; subjects in whom both FMA and basal plane angle measured <15 degrees), and Group III (n = 30; subjects in whom both FMA and basal plane angle measured >30 degrees). Lateral cephalograms with the mandible in rest position were traced and analyzed manually for evaluation of hyoid bone position. RESULTS The anteroposterior position of the hyoid bone was significantly forward in subjects with short face syndrome compared with normal subjects (P < .05) and subjects with long face syndrome (P < .001). The vertical position of the hyoid bone was comparable among subjects with different vertical jaw dysplasias. The axial inclination of the hyoid bone was more oblique in subjects with long face syndrome than in those with short face syndrome (P < .01). CONCLUSION The anteroposterior position of the hyoid bone was more forward in subjects with short face syndrome. The vertical position of the hyoid bone was comparable among subjects with different vertical jaw dysplasias. The axial inclination of the hyoid bone closely followed the axial inclination of the mandible.

Surface deterioration and elemental composition of retrieved orthodontic miniscrews

INTRODUCTION This study provides insight into surface and elemental analyses of orthodontic retrieved miniscrew implants (MSIs). The sole purpose was to investigate the behavior of MSIs while they are in contact with bone and soft tissues, fluids, and food in the oral cavity. The information thus gathered may help to understand the underlying process of success or failure of MSIs and can be helpful in improving their material composition and design. METHODS The study was carried out on 28 titanium-alloy MSIs (all from the same manufacturer) split into 3 groups: 18 MSIs were retrieved after successful orthodontic treatment, 5 were failed MSIs, and 5 were as-received MSIs serving as the controls. All MSIs were subjected to energy dispersive x-ray microanalysis to investigate the changes in surface elemental composition and to scanning electron microscopy to analyze their surface topography. Data thus obtained were subjected to suitable statistical analyses. RESULTS Scanning electron microscope analysis showed surface manufacturing imperfections of the as-received MSIs in the form of stripes. Their elemental composition was confirmed to the specifications of the American Society for Testing of Materials for surgical implants. Retrieved MSIs exhibited generalized surface dullness; variable corrosion; craters in the head, neck, body, and tip regions; and blunting on tips and threads. Energy dispersive x-ray analyses showed deposition of additional elements: calcium had greater significance in its proportion in the body region by 0.056 weight percent; iron was seen in greater proportion in the failed retrieved MSIs compared with the successful miniscrews; cerium was seen in greater proportions in the head region by 0.128 weight percent and in the neck region by 0.147 weight percent than in the body and tip regions of retrieved MSIs. CONCLUSIONS Retrieved MSIs showed considerable surface and structural alterations such as dullness, corrosion, and blunting of threads and tips. Their surfaces showed interactions and adsorption of several elements, such as calcium, at the body region. A high content of iron was found on the failed MSIs, and cerium was seen in the head and neck regions of retrieved MSIs.