The EPIYA-ABCC motif of Helicobacter pylori cagA gene and gastric carcinogenesis in Casablanca population.

Background: H. pylori infection induce atrophic gastritis (AG) and intestinal metaplasia (IM) that can lead to gastric cancer (GC). The severity of gastric lesions is related to H. pylori genetic diversity. The oncogenic potential of H. pylori cagA virulence factor is linked to its high polymorphic EPIYA motifs. Objectives: Our aim was to evaluate the association of EPIYA motifs with the risk of AG and IM in Casablanca population. Methods: A total of 210 patients suffering from gastric lesions (chronic gastritis, AG, and IM) was enrolled. H. pylori infection and the type of lesions were diagnosed by ureC PCR and histological examination, respectively. Detection of the cagA gene, and the type of EPIYA motifs, were carried out by PCR. Results: The prevalence of H. pylori and cagA gene was 95% and 37%, respectively. CagA-positive strains were associated with the risk of IM. The EPIYA motifs detected were: EPIYA-ABC (58%), EPIYA-ABCC (22%), and EPIYA-AB (20%). The EPIYA-ABCC motif was associated with the risk of IM (p-value = 0.007), compared to AG (p-value = 0.28). Conclusion: The EPIYA-ABCC motif might be a useful marker for the identification of patients at high risk of developing IM that can lead to GC.

Comparative Study of Helicobacter Pylori Resistance to Clarithromycin and Metronidazole and Its Association with Epidemiological Factors in A Moroccan Population.

OBJECTIVE: Knowledge of local antibiotic resistance is crucial to the adaption of the effective empirical first-line treatment for Helicobacter Pylori (H. pylori) infection. This study aimed to evaluate the prevalence of H. pylori resistance to clarithromycin and compare it with that of metronidazole, and highlight the impact of epidemiological factors and gastric lesions severity on H. pylori resistance. METHODS: The susceptibility to clarithromycin of 96 isolates was determined by PCR-RFLP and the susceptibility to metronidazole of 185 isolates was determined by classic PCR. RESULT: Our results showed that the prevalence of H. pylori resistance to clarithromycin ( 14.6%) was low compared to that recorded with metronidazole ( 62.7%). Moreover, we remarked that 7.3% of isolates were co-resistant to both antibiotics. The assessment of epidemiological factors' impact on the resistance to studied antibiotics has revealed no association. Besides, our results had demonstrated that the metronidazole and clarithromycin resistance was not related to the severity of gastric lesions. CONCLUSION: In our population, clarithromycin seems to be an effective antibiotic as long as the resistance rate of H. pylori is low. In contrast to metronidazole, it appears that this antibiotic will lose its efficacy, due to the high rate of resistance among our population. Therefore, each population must conduct their epidemiologic studies separately to survey the resistance profile of strains and choose the appropriate antibiotic, in order to avoid the failure of H. pylori eradication and the development of severe gastric diseases.

Association of Helicobacter pylori vacA polymorphisms with the risk of gastric precancerous lesions in a Moroccan population.

INTRODUCTION: Helicobacter pylori infection is the major risk factor of atrophic gastritis and intestinal metaplasia. The vacA gene is one of the most virulence factors of H. pylori and genetic diversity in its s, m, i, and d regions is associated with gastric lesions severity. This study aimed to investigate the association of vacA s, m, i, and d regions with the risk of atrophic gastritis and intestinal metaplasia in a Casablanca population. METHODOLOGY: A total of 210 patients suffering from gastric lesions (chronic gastritis, atrophic gastritis, and intestinal metaplasia) were enrolled. The type of lesion was diagnosed by histological examination. Detection of H. pylori infection and genotyping of vacA regions were carried out by PCR. RESULTS: The prevalence of H. pylori was 95%. The most common vacA genotypes were s2 (51.5%), m2 (77%), i2 (60.5%), and d2 (58.5%). VacA s1, m1, and i1 genotypes were associated with a high risk of intestinal metaplasia, while the vacA d1 genotype increases the risk of atrophic gastritis and intestinal metaplasia. The most common vacA combination was s2/m2/i2/d2 (52%), and it was more detected in chronic gastritis. The moderate virulent vacA combination (s1/m2/i1/d1) increases the risk of atrophic gastritis, while the most virulent vacA combination (s1/m1/i1/d1) increases the risk of intestinal metaplasia. CONCLUSIONS: Genotyping of vacA d region might be a reliable marker for the identification of vacA virulent strains that represent a high risk of developing precancerous lesions (atrophic gastritis and intestinal metaplasia).

Association of Tumor Necrosis Factor Receptor 1 Promoter Gene Polymorphisms (-580 A/G and -609 G/T) and TNFR1 Serum Levels with the Susceptibility to Gastric Precancerous Lesions and Gastric Cancer Related to H. pylori Infection in a Moroccan Population.

Chronic inflammation due to H. pylori infection is the risk factor of gastric cancer (GC). Through its receptor (TNFR1), TNF-α plays a fundamental role in inflammatory, infectious, and tumor processes. Dysregulation of TNFR1 gene expression could impact many biological processes that can lead to cancer. This study is aimed at evaluating the association of TNFR1 promoter gene polymorphisms (-580 A/G and -609 G/T) and TNFR1 serum levels with GC and precancerous lesion susceptibility. Patients suffering from gastric lesions (65 chronic gastritis, 50 precancerous lesions, and 40 GC) related to H. pylori infection and 63 healthy controls (HC) were involved in this study. Individuals are genotyped by TNFR1 gene promoter sequencing, and TNFR1 serum levels were measured by the ELISA quantitative method. Concerning TNFR1 -609 G/T locus, we noticed that the T allele was associated with an attenuated susceptibility to GC (OR = 0.4; p value = 0.02). At the genotypic level and under the recessive model, the TNFR1 -609 TT genotype showed a decreased risk of GC (OR = 0.3, p value = 0.03) compared to the combined (GG/GT) genotypes. TNFR1 serum levels have been increased together with gastric lesion severity (p value < 0.05). The TNFR1 -609 TT genotype seemed linked to a low level of sTNFR1 compared to GT and GG genotypes (p value = 0.07). Concerning TNFR1 -580 A/G locus, no significant relation was noticed between this polymorphism and GC susceptibility, as well as with the TNFR1 serum level. Our results suggest that the TNFR1 -609 T allele appears to have a protective effect against GC. High levels of TNFR1 serum levels seemed to be associated with the aggressiveness of gastric lesions. Therefore, our results suggest that TNFR1 -609 T/G polymorphism and the TNFR1 serum levels may be related to GC susceptibility.

Associations of the -238(G/A) and -308(G/A) TNF-α Promoter Polymorphisms and TNF-α Serum Levels with the Susceptibility to Gastric Precancerous Lesions and Gastric Cancer Related to Helicobacter pylori Infection in a Moroccan Population.

OBJECTIVE: Helicobacter pylori (H. pylori) induces the production of tumor necrosis factor-alpha (TNF-α), which is closely related to a gastric epithelial injury. TNF-α gene polymorphism and TNF-α serum levels are associated with various malignant conditions. Identification of the ideal marker for gastric cancer (GC) is still the leading aim of several trials. Physio-pathological considerations of GC led us to investigate the association of two TNF-α promoter polymorphisms (-308G>A and -238G>A), and TNF-α serum levels with the susceptibility to gastric precancerous (PL) and GC. METHODS: Patients suffering from gastric lesions (65 chronic gastritis, 50 PL, 40 GC) related to H. pylori infection , and 63 healthy controls (HC) were involved in this study. Individuals are genotyped by TNF-α gene promoter sequencing and TNF-α serum levels are measured by ELISA quantitative method. RESULTS: Regarding TNF-α-308 G/A locus, we noticed higher risk for GC (OR=4.3, CI 1.5-11.9, p-value=0.005)  and PL (OR=3.4, CI 1.2-9.2, p-value=0.01) for individuals with AA/GA genotypes compared to GG genotype. Concerning TNF-α-238 G/A locus, we noticed higher  risk for GC (OR=5.9, CI 1.2-27.5, p-value=0.01) and PL (OR=4.8, CI 1.3-18, p-value=0.01) for individuals with GG genotype compared to AA/GA genotypes. We noticed that TNF-α serum levels have been increased together with gastric lesions severity. Moreover, TNF-α-308 and TNF-α-238 A alleles seemed to, respectively, upregulate and downregulate TNF-α serum levels. CONCLUSION: The TNF-α -308 A allele has a promotive effect for GC progression, whereas the TNF-α -238 A allele has a protective function against GC progression. High levels of TNF-α seemed to be associated with the aggressiveness of gastric lesions. TNF-α gene polymorphisms and TNF-α serum levels might be helpful to select those patients who are at high risk for GC.

Characterization of PI3KCA and BRAF mutations in gastric adenocarcinoma: An approach to a personalized targeted therapy for Moroccan HER2 overexpressed patients.

BACKGROUND AND STUDY AIMS: Targeted therapies have an increasing importance in digestive oncology. To our knowledge, we are the first to report the distribution of PI3KCA and BRAF mutations in Moroccan HER2 overexpressed patients, in order to introduce targeted therapy in the arsenal of therapeutic modalities for management in Morocco. PATIENTS AND METHODS: 98 gastric adenocarcinoma tissue samples were collected. Further histological and immunohistochemical examinations were carried out at the Laboratory of Anatomy Pathology in Pasteur Institute-Morocco, in order to select HER2 positive cases. Out of 98 cases, 16 were found to be HER2-positive. The molecular study was performed for 55 good quality tissue samples including the HER2-positive ones, and activating mutations in H1047R PI3KCA and V600E BRAF were analyzed by Cast-PCR and Real-time PCR, respectively, at the Department of Molecular Biology, ANOUAL Specialized Center-Casablanca, Morocco. Statistical analyses were performed using the Epi-info software (version 6.09). RESULTS: Pi3KCA mutation was present in 8 cases (14,54%). BRAF mutation was present in 4 cases (7,27%) and 3 cases showed concomitant mutations. In total, 9 cases (16,36%) had PI3KCA and/or BRAF mutations. CONCLUSION: The association between HER2 expression and PI3KCA alteration in gastric adenocarcinoma is most probably necessary to identify trastuzumab responders. Consequently, the 83,64% rate of HER2-positive patients harboring wild-type mutations possibly represents the portion of patients responding to trastuzumab while the 16,36% rate of patients carrying at least one of the studied mutations represents the portion of potentially non responsive patients to the targeted therapy, and thus may be considered as good candidates for multi-drug targeted therapy.

Molecular epidemiology of the HHV-8 K1 gene from Moroccan patients with Kaposi's sarcoma.

The genetic variability of the human herpesvirus 8 (HHV-8) strains circulating in the populations living in the Maghreb region, an endemic area for HHV-8 and associated Kaposi's sarcoma, remains largely unknown. We have thus analyzed the genetic variation of the complete K1 gene of HHV-8 in a series of 35 viral strains, originating from 28 Moroccan patients with classic, AIDS-associated or iatrogenic Kaposi's sarcoma lesions. All but one of the 35 strains belonged to the large C molecular subtype. Furthermore, high genetic diversity within the C subtype was observed in the 35 sequenced HHV-8 K1 genes, with strains belonging to several and distinct subgroups highly supported from a phylogenetically viewpoint (e.g., C3, C7, C'' and C5). Considering these newly identified Moroccan viral strains in the context of 189 complete K1 genes, we were able to characterized, using the Simplot program, two main groups of recombinant chimeric K1 genes, either intertypic (C5) or intratypic (C7). In addition, the genetic characterization of the host maternal gene pool, through the analyses of mtDNA variation, did not provide evidence for any association between a particular human ethno-geographic background (i.e., North African vs. sub-Saharan African vs. West Eurasian linages) and any HHV-8 strain because both C' and C'' strains were randomly distributed among the different patients' population backgrounds.

Kaposi's sarcoma in Morocco: a pathological study with immunostaining for human herpesvirus-8 LNA-1.

AIMS: The Maghreb region is considered to be an endemic area for classical Kaposi's sarcoma (KS) but the few published reports have focused on clinical descriptions. We report here the clinical, virological and pathological features of 26 KS cases, including 17 classic forms, eight epidemic forms and one case of post-transplant KS. METHODS: Evidence of human herpesvirus (HHV)-8 infection was detected by serology, immunohistochemistry and polymerase chain reaction. RESULTS: Antibodies directed against HHV-8 latent nuclear antigen (LNA-1/ORF73) were present in sera from all 26 KS cases and the ORF26 HHV-8 gene fragment was amplified from the tumour DNA of all patients. KS lesions that met the classical criteria for KS (spindle cells, positive endothelial markers) and were immunostained with the anti-LNA-1 marker, demonstrated typical granular intranuclear labelling of the spindle cells in all but one case of KS, in which very few spindle cells were present. Furthermore, whereas LNA-1 staining was largely confined to spindle cells in the late nodular stage, it was also observed in endothelial cells forming the walls of slit-like vessels in early patch-stage lesions. CONCLUSION: This study confirms that Morocco is an endemic area for classical KS, which remains the most frequent type of KS in this country, and emphasises the value of the LNA-1 marker for the early diagnosis of KS lesions.