Said Gritli

Association of MICA-129 polymorphism with nasopharyngeal cancer risk in a Tunisian population.

Major histocompatibility complex (MHC) class I chain-related A (MICA) molecules mediate natural killer (NK) cell activation and T lymphocyte co-stimulation. A polymorphic methionine (met) to valine (val) variation at amino acid position 129 of the alpha2 heavy chain domain is in linkage disequilibrium with other allelic changes and seems to categorize MICA alleles into strong and weak binder of NKG2D receptor and thereby to influence effector cell function. We investigated here whether MICA-129 dimorphism is associated with susceptibility to/or resistance against developing nasopharyngeal cancer (NPC). DNA from 130 NPC patients and 180 healthy individuals from Tunisia were genotyped for MICA-129 variation. We found a higher frequency of MICA-129 val/val genotype in patients than in controls (corrected p value = 0.02) that could suggest a tumor escape mechanism because of failure to activate NK cells by MICA-129 val allele or absence of NK cell activation because of absence of MICA-129 met allele in individuals otherwise predisposed to viral/environmental factors.

Complementary determination of Epstein-Barr virus DNA load and serum markers for nasopharyngeal carcinoma screening and early detection in individuals at risk in Tunisia

Because nasopharyngeal carcinoma (NPC) has a close association with Epstein-Barr virus (EBV), measuring serum EBV DNA and anti-EBV serum marker concentrations could be a feasible method for NPC diagnosis, monitoring and probably screening especially in a community at risk. The aim of this study was to determine the EBV pattern in sporadic NPC and in high risk NPC Tunisian families in order to evaluate their risk factors and help for NPC screening. The rates of anti-EBV antibodies and EBV DNA were determined in the serum of 47 healthy members randomly selected from 23 NPC multiplex families with two or more affected members, 93 healthy Tunisian community controls chosen with the same age, sex and geographic origin as unaffected individuals and 66 EBV positive sporadic NPC patients whose serum was available before and after treatment. Unexpectedly, significant lower concentrations of anti-EA (Early Antigen) IgG and anti-VCA (Viral Capsid Antigen) IgG were found in unaffected members from NPC families than in healthy controls while viral loads were negative in all the tested sera. For sporadic NPC patients, anti-EA IgG and anti-VCA IgA concentrations were significantly higher than in healthy controls and these rates decreased after treatment. The level of EBV DNA load varied according to the condition of the tumour. This study suggests that in the Tunisian NPC families, screening for malignancy is based on serum concentrations but not on EBV DNA load while in the sporadic NPC group, serologic markers and EBV DNA load are complementary for diagnosis and follow-up.

Nasopharyngeal cancer (NPC) around the Mediterranean area: Standard of care☆

Mediterranean area (MA) represents a zone of intermediate incidence (1-5/100,000) for NPC, the highest frequency being observed in North Africa (NA) where it is characterized by a bimodal age repartition due to a first adolescence peak. In MA and NA, NPC remain diagnosed at advanced stages which impact poorly on overall and disease-free survival. Its therapy in MA followed the progresses and standardisation of protocols, based on concomitant chemoradiotherapy (CCRT) alone or preceded by induction chemotherapy (ICT) in advanced (N2-3, T3-4) stages, while localized cases are managed irradiation alone. NPC overall an disease-free survival improved, due to the use of combined chemo and radiotherapy.

Usefulness of IGF-1 serum levels as diagnostic marker of nasopharyngeal carcinoma.

BACKGROUND The role of IGF-1 in promoting cancer has been investigated for many years. The aim of this study is to explore the relationship between rates of IGF-1 and NPC and to evaluate association of IGF-1 with clinical parameters. MATERIALS AND METHODS IGF-1 levels was measured by Elisa test among 82 NPC patients and 60 healthy controls RESULTS Our results showed, for the first time, a significant increased levels of IGF-I in NPC by in comparison with healthy controls (p<0.01). According to the age, sex and tumor size of NPC patients, we demonstrated that IGF-1 concentrations are significantly higher in NPC aged over 30 years compared to patients aged less than 30 years (p<0.01). The IGF-1 levels are, also, higher among women compared to men (p<0.01). The concentrations of IGF-1 were positively correlated with tumor size of NPC patients (p<0.01). CONCLUSION IGF-I could be a good nasopharyngeal cancer diagnostic marker.

Laryngocele after Subtotal Laryngectomy

Introduction: Laryngocele is an air-filled dilatation of the laryngeal saccule that extends upward within the false vocal folds. Different etiologies lead to laryngocele congenital malformation, weakness of the laryngeal tissues and increased intralaryngeal pressure. Laryngocele may be a secondary iatrogenic complication following subtotal laryngectomy. Case Report: We report the case of a 61-year-old patient who presented an external laryngomucocele 8 years after a supracricoid partial laryngectomy with cricohyoidoepiglottopexy (SCPL-CHEP). We focus on the clinical aspects and therapeutic attitude, then discuss the physiopathological conditions that could generate this late complication. Conclusion: Laryngocele after subtotal laryngectomy should be considered a late iatrogenic complication. Histological examination is necessary after surgical management of laryngocele, as the association with cancer is frequent.

Overexpression of the Oncogenic Variant (KLF6-SV1) in Young NPC Patients and Correlation with Lack of E-Cadherin

Purpose The transcription factor Krüppel-like factor 6 (KLF6) regulates various cellular functions, such as metabolism, cell proliferation, and differentiation. KLF6 plays a key role in the development and progression of multiple human cancers. Methods Fifty primary biopsies and 10 normal nasopharyngeal mucosae were used to analyze by RT-QPCR the expression and the copy number of wtKLF6 and the spliced variants (KLF6-SV1, KLF6-SV2, and KLF6-SV3) in Tunisian patients with nasopharyngeal carcinoma. The expression analysis of E-cadherin and cyclin D1 was conducted by RT-QPCR and Western blot, respectively. Results The wtKLF6 was significantly downexpressed in tumors compared to normal tissues (p = 0.0015), whereas KLF6-SV1 and KLF6-SV2 were overexpressed in tumors compared to wtKLF6 and KLF6-SV3 (p < 0.0001). Copy number variation was reduced in tumors compared to normal tissues (p = 0.0071). Interestingly, KLF6-SV1 is associated with the juvenile form (p = 0.0003) which is more aggressive than the adult form of NPC. Furthermore, the oncogenic variant KLF6-SV1 was overexpressed in tumors lacking the expression of E-cadherin (p = 0.0022) suggesting its role in metastasis and tumor progression. The wtKLF6 is associated negatively with cyclin D1 in tumor tissues (p = 0.048). Conclusion The wtKLF6 was downexpressed in contrast with the oncogenic variants. Overexpression of KLF6-SV1 is associated with young patients, and loss of E-cadherin suggests that this variant correlated with the aggressiveness of NPC.

HLA-A*26-A*30 and HLA-DRB1*10 could be predictors of nasopharyngeal carcinoma risk in high-risk Tunisian families

We investigated human leukocyte antigen (HLA) profiles for Tunisians with nasopharyngeal carcinoma (NPC), their families, and a sample of unrelated healthy Tunisians in order to identify HLA specificities associated with familial NPC. HLA-A, -B, and -DRB1 typing was successful for 36 NPC patients, 72 unaffected family members, and 130 community controls, and the chi square or Fisher exact test was used to compare allele frequencies between cases and controls. We observed a consistent protective effect of HLA-DRB1*10 on NPC development. However, none of the NPC patients or their family members had a positive result for this HLA marker (0% vs 9.2% in controls, P = 0.047). In addition, HLA-A*26 was probably an induction marker, as its allelic frequency was significantly higher among NPC patients than among controls (P = 0.003) and among NPC patients than among at-risk family members (P = 0.067). Logistic regression analysis of the joint effect of selected HLA specificities showed that HLA-A*26 and HLA-A*30 were co-associated and have an important effect on NPC risk. Despite the small size of our cohort, we showed that HLA-A*26-A*30 and HLA-DRB1*10 might be predictive markers for NPC screening of Tunisian families with a high risk of NPC.