RAS/RAF/MAPK Pathway Mutations as Predictive Biomarkers in Middle Eastern Colorectal Cancer: A Systematic Review.

Background: This review article aims to investigate the prevalence and spectrum of rat sarcoma (RAS) and V-Raf Murine Sarcoma Viral Oncogene Homolog B (BRAF) mutations, and their connection with geographical location, clinicopathological features, and other relevant factors in colorectal cancer (CRC) patients in the Middle East. Methods: A systematic literature review, employing the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) framework, was conducted to investigate the association between the frequency of relevant mutations and the descriptive clinicopathological characteristics of CRC patients. Multiple electronic databases, including PubMed, Science Direct, Web of Science, Scopus, and Google Scholar, were searched to analyze the relevant literature. Results: A total of 19 eligible studies comprising 2960 patients with CRC were included in this review. A comprehensive analysis of the collected literature data as well as descriptive and methodological insights is provided. Men were predominant in reviewed studies for the region, accounting for 58.6%. Overall, RAS mutation prevalence was 38.1%. Kirsten RAS Viral Oncogene Homolog (KRAS) mutations were the most common, accounting for 37.1% of cases and distributed among different exons, with the G12D mutation being the most frequent in exon 2 (23.2%) followed by G12V (13.7%), G13D (10.1%), G12C (5.1%), G12A (5.04%), and G12S (3.6%). Neuroblastoma RAS Viral Oncogene Homolog (NRAS) mutations were identified in 3.3% of tumor samples, with the most common mutation site located in exons 2, 3, and 4, and codon 61 being the most common location for the region. The total mutation frequency in the BRAF gene was 2.6%, with the V600E mutation being the most common. Conclusion: The distribution patterns of RAS and BRAF mutations among CRC patients exhibit notable variations across diverse ethnic groups. Our study sheds light on this phenomenon by demonstrating a higher prevalence of KRAS mutations in CRC patients from the Middle East, as compared with those from other regions. The identification of these mutations and geographical differences is important for personalized treatment planning and could potentially aid in the development of novel targeted therapies. The distinct distribution patterns of RAS and BRAF mutations among CRC patients across different ethnic groups, as well as the regional variability in mutation prevalence, highlight the need for further research in this area.

Type I and III interferons are good markers to monitor COVID-19 pathophysiology.

The COVID-19 pandemic has caused millions of deaths and has resulted in disastrous societal and economic impacts worldwide. During SARS-CoV-2 infection, abnormal levels of pro-inflammatory cytokines have been observed and were associated to the severity of the disease. Type I (-α/ß) and Type III (IFN-λ) interferons are family members of cytokines that play an important role in fighting viral replication during the early phases of infection. The location and timing of the IFNs production have been shown to be decisive for the COVID-19 outcome. Despite the effectiveness of COVID-19 vaccines and with the emergence of new SARS-CoV-2 variants, a better understanding of the involvement of IFNs as players in antiviral immunity in the COVID-19 pathophysiology is necessary to implement additional potent prophylactic and/or therapeutic approaches. In this study, we investigated the role of type I and III IFN in COVID-19 pathophysiology. We first analyzed the IFN-α, IFN-ß and IFN- λ mRNA expression in nasopharyngeal swabs and blood samples from Moroccan patients infected with SARS-CoV-2 and secondly correlated these IFNs expressions with COVID-19 clinical and biological parameters. Our results showed that in the upper airways of patients with mild, non-severe, or severe COVID-19 manifestations, the IFN- α, - ß and - λ are expressed in the same manner as in controls. However, in blood samples their expression was downregulated in all groups. Univariate linear models with interferons as predictors to evaluate clinical-biological parameters highlighted that the main clinical-biological relations were found when testing: FiO2, Lymphocyte values and virus load. Furthermore, the multivariate models confirmed that quantifications of interferons during COVID-19 are good biological markers for tracking COVID-19 pathophysiology.

Clinical Significance of Somatic Mutations in RAS/RAF/MAPK Signaling Pathway in Moroccan and North African Colorectal Cancer Patients.

BACKGROUND: Mutations in RAS (KRAS, NRAS) and BRAF genes are the main biomarker predicting response to anti-EGFR monoclonal antibodies in targeted therapy in colorectal cancer (CRC). OBJECTIVE: Our study aims to evaluate the frequencies of KRAS, NRAS and BRAF mutations and their possible associations with clinico-pathological features in CRC patients from Morocco. METHODS: DNA was extracted from 80 FFPE samples using the QIAamp DNA FFPE-kit. RAS and BRAF mutations were assessed by pyrosequencing assays using Qiagen, KRAS Pyro®kit 24.V1, Ras-Extension Pyro®kit 24.V1 and BRAF Pyro®Kit 24.V1, respectively, and carried out in the PyroMark-Q24. RESULTS: RAS mutations were identified in 57.5% (56.2% in KRAS, 8.8% in NRAS). In KRAS gene, exon 2 mutations accounted for 93.3% (68.9% in codon 12, 24.4% in codon 13). Within codon 12, G12D was the most prevalent mutation (37.7%), followed by G12C (13.4%), G12S (8.9%) and G12V (6.6%). Within codon 13, the most frequently observed mutation was G13D (22.3%). The mutation rates of exon 3 and 4 were 15.6% and 13.3%, respectively. In exon 3 codon 61, 2.3% patients were detected with two concurrent mutations (Q61R, Q61H), and 4.4% with three concurrent mutations (Q61R, Q61H, Q61L). In NRAS gene, the mutation rates of exon 2, 3 and 4 were 57.1%, 28.6%, and 14.3%, respectively. G13A and Q61H were the most common mutations, accounting for 42.9% and 28.5%, respectively. There were 13% patients with concurrent KRAS/NRAS mutation and 4.3% wt KRAS with NRAS mutations. No mutations were identified in BRAF gene. In both sexes, KRAS codon 12 mutations were associated with higher stage III/IV tumors. Moreover, Patients whose tumor is in the proximal colon (56.3%) are more likely to harbor KRAS mutations than those tumor located in rectum (25%). CONCLUSION: RAS mutations could be useful in future target anti-EGFR therapy and molecular CRC screening strategy in Morocco.

Simultaneous detection of Neisseria meningitidis, Streptococcus pneumoniae and Haemophilus influenzae by quantitative PCR from CSF samples with negative culture in Morocco.

Bacteriological cultures from cerebrospinal fluids (CSF) have less sensitivity and specificity compared to quantitative PCR (RT-PCR), and multiple facts still conduct to the increase of negative culture. The aims of this study are to determine the molecular epidemiology and the simultaneous detection of bacterial meningitis in Morocco by using RT-PCR and compared this molecular approach with culture method to improve the etiological diagnosis of meningitis. The CSFs were collected over one-year period in 2018 in different hospitals covering all regions of the Kingdom of Morocco, from patients with suspected meningitis. The results showed the confirmation rate per culture recorded a rate of 33% and the RT-PCR of 70%. Molecular epidemiology is predominant of Neisseria meningitidis followed by Streptococcus pneumoniae and a dramatic reduction in meningitis due to Haemophilus influenzae following the introduction of conjugate vaccine in 2007. Also, the epidemiological profile shows a sex ratio M/F of 1.4 and a median age of 2 years. The national distribution showed a predominant of meningococcal disease followed by pneumococcal disease, especially a dominance of N. meningitidis over S. pneumoniae in two regions and a slight predominance of S. pneumoniae in the other two regions over N. meningitidis. Our research shows that culture in our country has less sensitivity and specificity than RT-PCR in diagnosis of bacterial meningitis and that molecular biology technique at bacteriology laboratories is desirable for diagnosis, early management of meningitis cases and in the context of the surveillance of meningitis in Morocco in parallel with culture.

Epidemiology and antibiotic resistance profile of bacterial meningitis in Morocco from 2015 to 2018.

Over a 4-year study period from 2015 to 2018, altogether 183 isolates of bacterial meningitis were collected from 12 hospitals covering the entire Moroccan territory. Neisseria meningitidis represented 58.5%, Streptococcus pneumoniae 35.5%, and Haemophilus influenzae type b 6%. H. influenzae type b mainly affected 5-year-olds and unvaccinated adults. N. meningitidis serogroup B represented 90.7% followed by serogroup W135 with 6.5%. Decreased susceptibility to penicillin G (DSPG) for all isolates accounted for 15.7%, with 11.6% being resistant to penicillin G (PG) and 4.1% decreased susceptibility. Cumulative results of all strains showed 2.7% decreased susceptibility to amoxicillin and 3.3% resistant, 2.2% of isolates were resistant to third-generation cephalosporin and 2.2% were decreased susceptible, 5.5% were resistant to chloramphenicol and 2.7% were resistant to rifampin. The frequency of DSPG observed in our study is more common in S. pneumoniae than in N. meningitidis (P < 0.05). These isolates have been found to be highly susceptible to antibiotics used for treatment and prophylaxis chemotherapy and the observed resistance remains rare. The impact of introduction of conjugate vaccines against H. influenzae type b and S. pneumoniae (PCVs) is an advantage in reducing meningitis cases due to these two species.

BRCA genetic screening in Middle Eastern and North African: mutational spectrum and founder BRCA1 mutation (c.798_799delTT) in North African.

BACKGROUND: The contribution of BRCA1 mutations to both hereditary and sporadic breast and ovarian cancer (HBOC) has not yet been thoroughly investigated in MENA. METHODS: To establish the knowledge about BRCA1 mutations and their correlation with the clinical aspect in diagnosed cases of HBOC in MENA populations. A systematic review of studies examining BRCA1 in BC women in Cyprus, Jordan, Egypt, Lebanon, Morocco, Algeria, and Tunisia was conducted. RESULTS: Thirteen relevant references were identified, including ten studies which performed DNA sequencing of all BRCA1 exons. For the latter, 31 mutations were detected in 57 of the 547 patients ascertained. Familial history of BC was present in 388 (71%) patients, of whom 50 were mutation carriers. c.798_799delTT was identified in 11 North African families, accounting for 22% of total identified BRCA1 mutations, suggesting a founder allele. A broad spectrum of other mutations including c.68_69delAG, c.181T>G, c.5095C>T, and c.5266dupC, as well as sequence of unclassified variants and polymorphisms, was also detected. CONCLUSION: The knowledge of genetic structure of BRCA1 in MENA should contribute to the assessment of the necessity of preventive programs for mutation carriers and clinical management. The high prevalence of BC and the presence of frequent mutations of the BRCA1 gene emphasize the need for improving screening programs and individual testing/counseling.

High frequency of mutator strains among human uropathogenic Escherichia coli isolates.

By using a panel of 603 commensal and pathogenic Escherichia coli and Shigella isolates, we showed that mutation rates of strains vary considerably among different ecotypes. Uropathogenic strains had the highest frequency of mutators, while strains from patients with bacteremia had the lowest mutation rates. No correlation between the mutation rates and antibiotic resistance was observed among the studied strains.