Prevalence of oral cavity, pharynx, larynx and nasal cavity malignancies in Amritsar, Punjab

Super enhancer loci of EGFR regulate EGFR variant 8 through enhancer RNA and strongly associate with survival in HNSCCs

Epidermal growth factor receptor (EGFR) has been shown to be overexpressed in human cancers due to mutation, amplification, and epigenetic hyperactivity, which leads to deregulated transcriptional mechanism. Among the eight different EGFR isoforms, the mechanism of regulation of full-length variant 1 is well-known, no studies have examined the function & factors regulating the expression of variant 8. This study aimed to understand the function of EGFR super-enhancer loci and its associated transcription factors regulating the expression of EGFR variant 8. Our study shows that overexpression of variant 8 and its transcription was more prevalent than variant 1 in many cancers and positively correlated with the EGFR-AS1 expression in oral cancer and HNSCC. Notably, individuals overexpressing variant 8 showed shorter overall survival and had a greater connection with other clinical traits than patients with overexpression of variant 1. In this study, TCGA enhancer RNA profiling on the constituent enhancer (CE1 and CE2) region revealed that the multiple enhancer RNAs formed from CE2 by employing CE1 as a promoter. Our bioinformatic analysis further supports the enrichment of enhancer RNA specific chromatin marks H3K27ac, H3K4me1, POL2 and H2AZ on CE2. GeneHancer and 3D chromatin capture analysis showed clustered interactions between CE1, CE2 loci and this interaction may regulates expression of both EGFR-eRNA and variant 8. Moreover, increased expression of SNAI2 and its close relationship to EGFR-AS1 and variant 8 suggest that SNAI2 could regulates variant 8 overexpression by building a MegaTrans complex with both EGFR-eRNA and EGFR-AS1. Our findings show that EGFR variant 8 and its transcriptional regulation & chromatin modification by eRNAs may provide a rationale for targeting RNA splicing in combination with targeted EGFR therapies in cancer.

Dysregulation of miR-200 family microRNAs and epithelial-mesenchymal transition markers in oral squamous cell carcinoma

MicroRNAs (miRNAs) are reported to function as a major component in the cellular signaling circuit, which regulates epithelial-mesenchymal transition (EMT). Dysregulation of the microRNA-200 (miR-200) family and EMT-associated genes enables tumor metastasis and resistance to therapy. The present study profiled miR-200 family members miR-200a, miR-200b, miR-200c, miR-141 and miR-429, and also several EMT-regulatory genes including zinc finger E-box-binding homeobox (ZEB)1, ZEB2, epithelial cadherin and vimentin in 40 oral primary tumors in order to understand their role(s) in oral squamous cell carcinoma (OSCC). The reverse transcription-quantitative polymerase chain reaction was used to analyze each sample. Results demonstrated a significant downregulation of miR-200 family members in tumors with a history of tobacco chewing/smoking (P<0.0006, P=0.0467, P=0.0014, P=0.0087 and P=0.0230, respectively) and undifferentiated pathology (miR-200a, P=0.0067; miR-200c, P=0.0248). EMT markers ZEB2 (P=0.0451) and vimentin (P=0.0071) were significantly upregulated in the oral tumors. Furthermore, ZEB2 antisense RNA1 was overexpressed in 50% of OSCC samples (P=0.0075). EMT-regulatory genes did not exhibit any association with clinical outcome. The present study also analyzed the expression of EMT-regulatory genes in 523 head and neck squamous cell carcinoma (HNSCC) samples from The Cancer Genome Atlas (TCGA) database, and the association with treatment outcome. Analysis of TCGA datasets also demonstrated no significant association in the expression of EMT markers with disease recurrence and treatment outcome. The results of the present study revealed dysregulation of miR-200 family miRNAs and EMT-regulatory genes in OSCC without any significant effect on treatment outcome.

Expression profiling of long non-coding RNA identifies linc-RoR as a prognostic biomarker in oral cancer

Oral squamous cell carcinoma is the most aggressive cancer that is associated with high recurrence, metastasis, and poor treatment outcome. Dysregulation of long non-coding RNAs has been shown to promote tumor growth and metastasis in several cancers. In this study, we investigated the expression of 11 selected long non-coding RNAs that are associated with cell proliferation, metastasis, and tumor suppression in oral squamous cell carcinomas and normal tissues by quantitative real-time polymerase chain reaction. Out of the 11 long non-coding RNAs profiled, 9 were significantly overexpressed in tumors with tobacco chewing history. Moreover, the long non-coding RNA profile was similar to the head and neck cancer datasets of The Cancer Genome Atlas database. Linc-RoR, a regulator of reprogramming, implicated in tumorigenesis was found to be overexpressed in undifferentiated tumors and showed strong association with tumor recurrence and poor therapeutic response. In oral squamous cell carcinomas, for the first time, we observed linc-RoR overexpression, downregulation of miR-145-5p, and overexpression of c-Myc, Klf4, Oct4, and Sox2, suggesting the existence of linc-RoR-mediated competing endogenous RNA network in undifferentiated tumors. Taken together, this study demonstrated the association of linc-RoR overexpression in undifferentiated oral tumors and its prognostic value to predict the therapeutic response.

Synergistic Effect of Sorafenib and Radiation on Human Oral Carcinoma in vivo

Oral squamous cell carcinoma often causes bone invasion resulting in poor prognosis and affects the quality of life for patients. Herein, we combined radiation with sorafenib, to evaluate the combination effect on tumor progression and bone erosion in an in situ human OSCC-bearing mouse model. Treatment procedure were arranged as following groups: (a) normal (no tumor); (b) control (with tumor); (c) sorafenib (10 mg/kg/day); (d) radiation (single dose of 6 Gy); (e) pretreatment (sorafenib treatment for 3 days prior to radiation), and (f) concurrent treatment (sorafenib and radiation on the same day). The inhibition of tumor growth and expression level of p65 of NF-κB in tumor tissues were the most significant in the pretreatment group. EMSA and Western blot showed that DNA/NF-κB activity and the expressions of NF-κB-associated proteins were down-regulated. Notably, little to no damage in mandibles and zygomas of mice treated with combination of sorafenib and radiation was found by micro-CT imaging. In conclusion, sorafenib combined with radiation suppresses radiation-induced NF-κB activity and its downstream proteins, which contribute to radioresistance and tumorigenesis. Additionally, bone destruction is also diminished, suggesting that combination treatment could be a potential strategy against human OSCC.

Clinical profile of pharyngeal malignancy in a tertiary care centre, state of uttarakhand

Pharynx is a common site of malignancy in the head and neck region. This study presents a series of 94 cases of pharyngeal malignancy conducted at Himalayan Institute of Medical Sciences, Dehradun, Uttarakhand in the Department of Otorhinolaryngology for a period of one year (2009-2010). Mean age at presentation was 56.8 years (age range 18-100 years). Male:Female ratio was 8.4:1.0. Maximum patients belonged to lower socio-economic status as per Kuppuswamy's classification (2003). Majority of them were farmer (38.2%) by occupation and belonged to rural areas. 90.4% patients had history of tobacco smoking. Dysphagia was the commonest chief complaint. The most common subsite was oropharynx (51.0%) followed by hypopharynx (45.7%). Ulceroproliferative growth was the most common clinical finding. Histopathologically, squamous cell carcinoma (94.6%) was the commonest. CECT was the commonest and most useful radiological investigation done to see the extent of the disease.

Prevalence of head and neck cancers in the north east-An institutional study

In India, head and neck cancers (HNCA) account for 30-40% cancers at all sites. In North-eastern India, where this study was conducted, tobacco related oral cancer is very common which may be due to widespread habit of chewing tobacco. The lack of any study in this regard and alarmingly high prevalence of cancers of head and neck in this part of India has prompted us to take up this study. A retrospective study on prevalence of cancer in various head and neck regions like oropharynx, oral cavity, pharynx, larynx, oesophagus and nasal cavity was conducted in Department of Otolaryngology, Silchar Medical College and Hospital from 1993 to 2004.The prevalence is found to be significantly high at 54.48%, affecting males more than females in the age group of 40-69 years. HNCA of oropharynx and oral cavity constituted a major burden of total body cancer.This study hopes to quantify and analyze the spectrum of HNCA and should help as a starting point for a much needed population based study in this region. A comprehensive effort is needed to identify the cause of such high prevalence, generate awareness and treatment options suited to meet this challenge.

Pattern of ear, nose, pharynx, larynx and oesophagus(enplo) cancers in a rural based hospital

A total of 1527 cases of total body cancer (TBC) presented at M G I M S between 1(st) Jan. 1992 to 30(th) April 1999. ENPLO cancers comprised 656 (42.9%)casees. Ca cervix was the commonest cancer amongst TBC comprising 15.3% cases. Ca oral cavity was the commoncest among ENPLO cancers comprising 24.3% cases followed by Ca oesophagus comprising 19.1% Ca oropharynx comprising 16.9%, Ca hypopharynx comprising 13.4%, Ca larynx comprising 11.3% and Ca Nose and PNS comprising 5.7% cases. ENPLI cancers constiuted the major burden of TBC in our hospital.