Impact of toll-like receptor 4 variations on nasopharyngeal carcinoma risk and survival in tunisian population.

INTRODUCTION: The Toll-like receptor 4 (TLR4), an important member of the host's innate immune response, is coded by a polymorphic gene. This polymorphism could be a predisposing factor for NasoPharyngeal Carcinoma (NPC). AIM: To determine the association between TLR4 gene polymorphisms and the susceptibility to NPC in a cohort of Tunisian affected patients. METHODS: Genomic DNAs from 245 unrelated patients affected by undifferentiated carcinoma type (UCNT) and 264 unrelated healthy controls were genotyped for the five single nucleotides polymorphisms (SNPs) of TLR4 locus (4434 A>G (rs1927914),7263 G>C (rs10759932), 6134 A>G(rs4986790), 8851C>T (rs 4986791), 5272 T>C(rs11536889), +8469 T>C (rs11536891)) by Taqman® 5'-nuclease assay. RESULTS: Among all polymorphisms studied, only the rs4986790 G and rs4986791 T alleles were significantly more prevalent in patients' group than controls (45% vs. 38%; p=0.03; pc=0.06) and increased the risk of the NPC (OR=1.3, 95% CI=1.01-1.69). Also, we found that the frequency of the rs4986790 AA and rs4986791 TT genotypes was significantly higher in controls than in patients (25.7% vs 37%; p=0.006, pc=0.02) and conferred a protector factor in NPC (OR= 0.59, 95% CI= 0.39-0.87). Further, based on the Kaplan-Meier survival curve we observed also the positive effect ofrs1927914 AA genotype on a prognostic of NPC (p=0.006; pc=0.01). CONCLUSION: Our study demonstrated that impaired production of TLR4 seems to be a risk factor of NPC development but functional studies are needed to confirm these findings. As to rs1927914 AA appears to be a good biomarker for better survival in a patient with NPC.

Soluble MICA and anti-MICA Antibodies as Biomarkers of Nasopharyngeal Carcinoma Disease.

The MHC class I chain-related molecule A (MICA) is a ligand for the activating natural killer (NK) cell receptor NKG2D. A part from its genetic diversity, MICA is characterized by the presence of membrane-bound and soluble isoform (sMICA) and by the propensity to elicit antibody-mediated allogeneicity (MICA Abs). Altogether such properties are important in the cancer setting. Here, we investigated whether MICA polymorphism, serum level of sMICA and MICA antibodies (Abs) may influence nasopharyngeal carcinoma (NPC) risk. 274 NPC naïve of treatment patients and 275 healthy individuals, all originating from Tunisia were included and genotyped. Among them, 160 sera from patients and 51 from controls were analyzed for the sMICA level by ELISA and were tested for the presence of MICA Abs by Luminex assay. The statistical analysis showed that: (1) we extend and confer our previous finding concerning Val/Val association with risk of NPC (p = .02, OR = 1.56; 95%CI [1.12-2.11]). (2) The higher level of sMICA characterized patients advanced stage of the disease. (3) The 18 (78%) of patients having MICA Abs exhibit all a non-advanced stage of the tumor extension at presentation. MICA129 Met /Val, sMICA and MICA Abs could be potential biomarkers of prediction, the diverse staging of NPC and hence prognostic and treatment.

MICA-129Met/Val Polymorphism Is Associated with Early-Onset Breast Cancer Risk.

The major histocompatibility complex class I-related chain A (MICA), expressed on cell surface, plays an important role in the elimination of both virus-infected cells and tumor through the activation of the natural killer (NK) receptor NKG2D. A polymorphic change from methionine (Met) to valine (Val) at amino acid position 129 categorizes MICA alleles into strong and weak binders for the NKG2D receptor and has been found in a variety of immune-related disorders. In this study, we investigated the potential interaction between genetic polymorphism of MICA and the development of breast cancer. We recruited 192 unrelated Tunisian women affected by breast cancer and 205 controls age-matched women, all genotyped for MICA-129 Met/Val (rs 1051792). A significant association was found between the Val allele and Val/Val genotype and the risk of breast cancer (p = 0.002, OR = 1.64, 95% CI = [1.17-2.27]; p = 0.002, OR = 1.88, 95% CI = [1.24-2.87], respectively). After stratification with clinical-pathology parameters, we found that 71% of women aged lower than 40 years had a Val/Val genotype versus 49% (p = 0.014). About 72% of these patients having a family history of cancers had a Val/Val genotype (p = 0.04). These results suggest that tumor escape mechanism because of failure in order to activate NK cells by MICA-129 Val allele may play a role in individual susceptibility for breast cancer development in Tunisian women.

MDM2 344T>A polymorphism; could it be a predictive marker of anthracycline resistance?

PURPOSE: To find a possible association between the Mouse Double Minute 2(MDM2) 344T>A, alone and in combination with p53 72 Arg/Pro polymorphism, and resistance to anthracycline-based chemotherapy of breast cancer in Tunisia. METHODS: This study enrolled 542 patients with invasive ductal carcinoma (IDC) treated with anthracycline-based chemotherapy. Genomic DNA was isolated from whole blood, using the phenol chloroform method. Anthracycline response was scored according to the World Health Organization (WHO). MDM2 344T>A polymorphism was genotyped using real time polymerase chain reaction (RT-PCR) with the TaqMan method. Data was statistically analyzed using the x2 test. RESULTS: Response was evaluated in 400 patients, of whom a quarter was found to be resistant to chemotherapy. Genetic data revealed that resistance to anthracycline-based chemotherapy did not seem to be correlated with 344T>A polymorphism in the studied population. Also, no significant association was found between the single nucleotide polymorphism (SNP) 344T>A status and clinicopathologic parameters (p>0.05 for all comparisons). Moreover, analysis of p53 rs1042522 and MDM2 rs1196333 combination showed no significant association between these two genetic variants and anthracycline resistance (p=0.2). CONCLUSIONS: Our findings provide no evidence indicating that SNP 344 T>A may affect response to anthracycline-based chemotherapy. However, the results obtained from the combination of SNPs 344T>A of MDM2 and 72 Arg/Pro of p53, do not support the hypothesis of the prominent role of common p53 and MDM2 variations in the genetic mechanisms of chemotherapy resistance in breast cancer.

[Genetic polymorphism of cytochrome P450 2E1 and the risk of nasopharyngeal carcinoma]. / Polymorphisme génétique du cytochrome P450 2E1 et le risque du cancer du nasopharynx.

Cytochrome P450 2E1 (CYP2E1) is a detoxifying enzyme that belongs to the phase I metabolism of xenobiotics. This enzyme is encoded by a highly polymorphic gene whose common polymorphism corresponds to the substitution of cytosine (C) and thymine (T) at position -1019 (rs2031920). This polymorphism has been identified in several cancers including nasopharyngeal cancer (NPC). The study involved 124 patients with nasopharyngeal carcinoma, compared with 166 healthy controls. The presence or absence of the polymorphism is determined by PCR-RFLP. The frequency comparison between the two groups is determined by the χ(2) test. The analysis of our results showed a significant difference between the two groups regarding the mutant genotype (C2/C2) (5% vs. 0.5%, P=0.04) and has a risk factor for NPC in Tunisia (OR=8.39; CI 95% [0.99-388.1]). Also, the C2 allele was significantly associated with the group of patients than the control group (6% vs. 2%, P=0.016) and increased three times the risk of NPC in Tunisia (OR=2.99, CI 95% [1.12-8.79]). Our results confirm the results reported in other populations and emphasize the importance of the involvement of this gene in the development of detoxification of the NPC, which seems more and more strongly associated with environmental factors.

Polymorphisms in oxidative stress-related genes are associated with nasopharyngeal carcinoma susceptibility.

Nasopharyngeal carcinoma (NPC) is a complex multifactorial disorder involving both genetic and environmental factors. Polymorphisms of genes encoding nitric oxide synthase (NOS) and antioxidant glutathione-S transferases (GSTs) have been associated with various tumors. We examined the combined role of NOS3, NOS2 and GST polymorphisms in NPC risk in Tunisians. We found that NOS3−786C allele and −786 CC genotype, NOS3+894T allele and +894 GT+TT genotypes, NOS2−277 G allele and −277 GG genotype, and GSTT1 del/del genotype, are more prevalent in NPC patients as compared to healthy controls. Our results suggest that genetically driven dysfunction in red­ox stress pathway could augment the risk in NPC-susceptible individuals.

[Immunogenetics of nasopharyngeal carcinoma]. / Immunogénétique du cancer du nasopharynx.

Nasopharyngeal carcinoma (NPC) is a complex multifactorial disorder involving both genetic and environmental factors. Genetic predisposition linked to the immune system has been associated with various tumors. This involves genetic diversity of the genes encoding the molecules of the immune response such as inflammation and anti-tumor surveillance. In this work, we examined the impact of the immunogenetic diversity on the risk of the NPC in different populations studied. These data show that the interindividual variability of the genetic regulation of immune processes increases the risk of NPC in individuals previously predisposed due to other risk factors (genetic / environmental). This synthesis, in addition to the predictive aspects, could provide innovative research for the development of new therapeutic approaches.

[Phenotypic and molecular changes of hemoglobinopathies in cancer]. / Variation phénotypique et moléculaire des hémoglobinopathies en milieu carcinologique.

BACKGROUND: The abnormalities of the haemoglobin divide into qualitative abnormalities and quantitative abnormalities. This variant contains polymorphisms often useful as markers of population. At present more than 693 types of abnormal haemoglobin are listed. This hemoglobinopathies can arise at reached subjects of cancerous pathologies. AIM: To bring to report association hémoglobinopathies-cancers. METHODS: Our study was realized to the Institute Salah azaiz (ISA) concerning hémoglobinopathies in carcinologic environment over a period spreading out of May 2004 in February 2008. The phenotypic and biochemical study of haemoglobin revealed the presence of 328 carriers of abnormalities of the haemoglobin on a total of 10550 patients followed to ISA. 7 types of abnormalities of the haemoglobin were identified (HbS, Hb C, Hb O arab, Hb D, Hb G, fast mutant and ß thalassemia. RESULTS: The sickle cell line represents the most wide-spread hémoglobinopathie (51.3 %). 48.2 % of the carrier subjects of abnormalities of the haemoglobin are followed for malignant pathologies. Among these hemoglobinopathies, we revealed the presence of two fast mutants of the haemoglobin corresponding to the haemoglobin Bangkok. This type of rare mutant is described for the first time in Tunisia. According to the genotypic study by these two cases, the haemoglobin Bangkok results from the replacement at the level of the chain ß some aspartic acid by the wisteria, further to a transfer at the level of the codon 56. A phenotypic study family revealed the presence of similar transfers at certain members of the family. CONCLUSION: Our work allowed us to notice a relatively important frequency of rare abnormalities of the haemoglobin at patients presenting varied tumoral processes.

Prognostic value of preoperative carcinoembryonic antigen level in colorectal cancer in Tunisia.

AIM: To evaluate the prognostic value of preoperative serum carcino-embryonic antigen (CEA) level in patients with colorectal cancer. METHODS: This retrospective study included 125 colorectal cancer patients aged from 14 to 87 years, surgically treated between January 2001 and December 2006. Preoperative serum CEA was measured by chemiluminescence assay. RESULTS: within the patients, 57 were males and 68 females. They have tumours classified Dukes A in 2 patients, B in 24 patients, C in 53 patients and Dukes D in 46 patients. Median follow-up period was 24 months (range, 4 - 72 months). The relapse-free survival was significantly higher in patients with CEA < 5 ng/ml compared to CEA ³ 5 ng/ml, (p < 0.0001). We observed significant differences in relapse-free survival between patients with CEA < 5 ng/ml and those with CEA ³ 5 ng/ml among patients classified as Dukes stage B (p=0.007) and C (p < 0.0001). However, there was no significant difference in relapse-free survival among those classified as Dukes stage D. Cox multivariate analysis demonstrated that preoperative serum CEA level was a significant independent prognostic factor for relapse-free survival (hazard ratio: 6.49, 95% CI, 3.09 to 13.62, p < 0.0001). CONCLUSION: Preoperative serum CEA is a reliable predictor factor for recurrence in patients with CRC. CEA might be used in staging system and will be useful for therapeutic orientation in patients undergoing curative resection of CRC.

[Changes in serum lipids in patients with colorectal cancer]. / Variation du bilan lipidique chez des malades ayant un cancer colorectal.

AIM: To evaluate and assess disruptions of serum lipids at patients having a colorectal cancer. METHODS: Our prospective study interested 30 patients, from 26 to 93 year old, presenting a colorectal cancer confirmed histologically, examined during the period going from March 2003 to April 2004. Thirty healthy controls were examined in parallel. All patients undergo three blood samples respectively in preoperative, 48h and 6 months after surgical operation. The analyses carried out were determination of a total serum cholesterol, HDL (high density lipoprotéin) and LDL (low density lipoprotein) cholesterol, serum triglyceride and serum apoprotein (AI and B) RESULTS: We noticed a decrease of total serum cholesterol level in 43% of the cases associated to the reduction of the HDL and the LDL cholesterol in respectively 30% and 76% of cases. The mean values of total serum cholesterol, HDL and LDL cholesterol rates were significantly lower for patients compared to those of controls (p respectively : 0.001; 0.04 and 0.001). Moreover, the level of total serum cholesterol varied significantly with tumor localization ( p= 0,02). CONCLUSION: Serum lipid disruptions affect essentially total cholesterol, HDL and LDL cholesterol. It would be therefore interesting to evaluate their rate at the basal state in order to follow their evolution after treatment in colorectal cancer.

[Importance of biologic parameters in Helicobacter pylori gastritis: comparison with histological results]. / Intérêt de certains paramètres biologiques au cours de la gastrite à Helicobacter pylori: comparaison avec les résultats histologiques.

Helicobacter pylori (HP) chronic gastritis can lead to precursor stages of gastric cancer. New biological markers have been proposed to study the gastric mucosal state. We evaluate biological results in comparison with histological ones in a dyspeptic population. Forty nine dyspeptic patients underwent endoscopy with gastric biopsies for histological examination. Blood samples were obtained to measure levels of gastrin 17 (G17), pepsinogen 1 (PG1), pepsinogen 2 (PG2) and the rate of anti-HP IgG antibodies. Four patients have a healthy gastric mucosa and 45 have a gastritis (32 have a nonatrophic gastritis and 13 an atrophic one). An increase in the level of PG2 and a decrease of the PG1/PG2 ratio were noticed in the group of subjects with a nonatrophic gastritis compared to the healthy mucosa group. The decrease of the PG1/PG2 ratio was more important in the corpus atrophic gastritis group than in the antrum restricted atrophic gastritis one. In conclusion, in front of dyspeptic patients, we advice to practice in first intention the measurement of the serological level of G17, PG1, PG2 and anti-HP IgG antibodies.

[Importance of determination of C reactive protein (CRP), carcinoembryonic antigen (CEA) and lactic dehydrogenase (LDH) in colorectal cancer]. / Intérêt des dosages sériques de la protéine c réactive (crp), de l'antigène carcino embryonnaire (ace) et de la lacticodeshydrogenase (ldh) dans le cancer colorectal.

AIM: Evaluate and show the importance of CRP, ACE and LDH in colorectal cancer. METHODS: Our prospective study interested 30 patients, from 26 to 93 years old and present a colorectal cancer, confirmed histologically, during the period going from March 2003 to April 2004, and 30 healthy controls. A blood sample was collected from each patient respectively in preoperative, 48 hours before any treatment, and 6 months after surgical operation to measure serum LDH, CRP, and ACE. RESULTS: The mean serum of LDH, CRP and ACE values were significant higher in patients than those in controls (p respectively: 0,01; 0,04 et 0,01). Moreover, the level of three parameters varied significantly with stages of tumor. After follow up, we have noticed e normalisation of the mean of the level of LDH, CRP and ACE with favorable evolution. Analysis of survival at 2 years showers that survival is better in patients with normal value of CRP, ACE and LDH. CONCLUSION: CRP, LDH and ACE values have a great importance during follows up after colorectal cancer surgery.

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.

Value of anti-mutated citrullinated vimentin antibodies in diagnosing rheumatoid arthritis.

We assessed the diagnostic value of anti-mutated citrullinated vimentin antibodies (anti-MCV) and compared it with those of anti-cyclic citrullinated peptide antibodies (anti-CCP), IgA (ARF), IgM (MRF) and IgG (GRF) rheumatoid factors for rheumatoid arthritis (RA). Serum samples of 170 RA patients, with early and established RA, and 309 controls were tested for anti-MCV, anti-CCP, ARF, MRF and GRF using commercially available ELISA kits. Cut off of different tests was determined with ROC curves. The sensitivity and the specificity of anti-MCV were 74.1 and 79%, respectively. Sixty-five of 309 (21%) controls were anti-MCV positive. Sensitivity and specificity of anti-CCP were 72.4 and 96.1%, respectively. Only 12 of 309 (3.9%) controls were anti-CCP positive. Sensitivity of ARF, MRF and GRF were 64.1, 65.9 and 68.2%, respectively. Their specificity was 79.6, 74.4 and 68.9%, respectively. No significant association was observed between the antibodies tested and extrarticular manifestations. Anti-MCV shows comparable sensitivity but lower specificity than that of anti-CCP. They do not appear to be very useful in the diagnosis of RA.

[Erythropoietin in cancer patients with anemia]. / Erythropoietine chez des patients cancereux anemiques.

OBJECTIVE: The aim of this study is to evaluate the endogenous erythropoietin production in cancer patients with anemia. METHODS: Our prospective study interested 99 cancer patients with anemia from 17 to 80 years old, during the period going from March 2002 to December 2004, and 31 healthy individuals with anemia caused by iron deficiency. A blood sample was collected from each patient, as well as healthy individuals to measure serum erythropoietin, C reactive protein and ferritin. RESULTS: The increase of serum erythropoietin was significantly lower in patients than in healthy individuals (P < 0.05). 25.2% of our cancer patients have inflammatory anemia and 74.7% presented microcytic anemia associated with increase of serum ferririn and CRP. These values were significantly higher than in healthy individuals (p < 0.05). CONCLUSION: Anemia in cancer patients results from activation of inflammatory system, which inhibit erythropoietin production. Apart from etiologic treatments, anemia can be treated with recombinant human erythropoietin.

Diagnostic performances of anti-cyclic citrullinated peptide antibodies in rheumatoid arthritis.

To evaluate the rheumatoid arthritis (RA) diagnostic performances of anti-cyclic citrullinated peptide antibodies (anti-CCP). Anti-CCP was detected by an enzyme linked immunosorbent assay in 164 patients with RA and 343 controls. In addition, anti-CCP predictive value for radiological damage were investigated in 37 recent-onset RA patients followed up prospectively for 2 years. Radiological damages were assessed by Sharp method modified by van der Heijde. The sensitivity of anti-CCP was 78.7% and the specificity was 95.6%. The positive predictive value and the negative predictive value were 90.2% and 90.3%, respectively. Anti-CCP were detected in sera of 79.3% of patients with recent onset RA and 78.3% of patients with long disease duration. In univariate and multivariate analyses, anti-CCP were not predictive for radiological damage. Our study confirms the high diagnostic performances of anti-CCP in RA. They are very useful to aid the diagnostic of RA in clinical practice.

[Erythropoietin levels in perioperative period in cancer patients]. / Variation de l'érythropoïétine sérique chez des malades opérés en chirurgie carcinologique.

Anemia is frequent in cancer patients, is the result of decreased erythropoietin production. In fact in cancer, alteration of immune system alters iron metabolism and inhibits erythropoietin production. In this study we proposed to determine the profile of erythropoietin secretion in anaemic cancer patients in the pre and postoperative period. Our prospective study from January to March 2005 included 41 anemic cancer patients from 30 to 79 years old and 31 healthy individuals with iron deficiency anemia. A measure of erythropoietin, CRP, ferritin, iron levels and hemoglobin were released in healthy individuals and in cancer patients in preoperative period (J0) and postoperative period (J3, J8, J21). In preoperative period, the increase of serum erythropoietin was significantly lower in patients than in healthy individuals. In postoperative period, the levels of erythropoietin at J3 and hemoglobin's at J8 and J21 were significantly higher than in preoperative period (J0) (p < 0.05). In conclusion, despite the presence of inflammatory syndrome caused by surgery, cancer patients with anaemia increase their erythropoietin production in immediate postoperative period.

[Seric soluble interleukin-2 receptor alpha in nasopharyngeal carcinoma in Tunisia. Prospective study about 45 cases]. / Taux serique du recepteur alpha soluble de l'interleukine 2 dans le carcinome du nasopharynx en Tunisie. Etude prospective sur 45 cas.

BACKGROUND: Soluble interleukin-2 receptor alpha (slL-2Ralpha) is a well-known indicator of T-cell activation noted to be increasing in nasopharyngeal cancer. The aims of this study were to evaluate the importance of the use of this marker in nasopharyngeal carcinoma. METHODS: Our prospective study interested 45 patients (35M/10F) with a mean age of 49 years (15 to 78), presenting a nasopharyngeal carcinoma histologically confirmed and 61 healthy controls. A blood sample was collected from each patient before any treatment, as well as controls to measure sIL-2Ralpha by immunoenzymatic assay. According to the disease status after a period of follow-up ranging from three to 22 months (median 12 months), patients were divided into two groups: The remission group (n=28) represented those with favourable evolution and a second group of 15 patients with unfavourable evolution (2 death, 4 cases of persistent primary disease and 9 patients with distance metastasis). 2 patients were lost to follow-up. RESULTS: serum sIL-2Ralpha levels were significantly higher in patients vs healthy controls (p < 0.0001). The serum levels correlated with the stage T of NPC (p = 0.01). Patients having a favourable evolution have lower sIL-2Ralpha levels before treatment vs those with unfavourable evolution without statistical difference. CONCLUSION: Measurement of serum sIL-2Ralpha provides a good estimation of the nasopharyngeal tumor burden. The usefulness of this marker as a parameter to predict prognosis in NPC should be examined further.

[Biological investigation of thyroid cancer]. / Exploration biologique du cancer de la thyroide.

Thyroid carcinomas represent the most common endocrine malignancy, and several biological markers are proposed according to the different types of this cancer: for papillary cancer, thyroglobulin constitutes an excellent prognostic factor and rearrangements of ret oncogene can be useful in diagnosis. In sporadic medullary carcinoma, calcitonin is a diagnosis marker of choice, and coupled with ACE, can prevent relapse. Regarding familial medullary carcinoma, mutation screening in ret oncogene leads to early detection of new cases.