Study of Single Nucleotide Polymorphisms Associated with Breast Cancer Patients among Arab Ancestries.

The aim of this study is to investigate the single nucleotide polymorphisms (SNPs) associated with breast cancer in our population of Arab patients. We investigated 26 breast cancer patients and an equal number of healthy age- and sex-matched control volunteers. We examined the exome wide microarray-based biomarkers and screened 243,345 SNPs for their possible significant association with our breast cancer patients. Successfully, we identified the most significant (p value ≤9.14 × 10-09) four associated SNPs [SNRK and SNRK-AS1-rs202018563G; BRCA2-rs2227943C; ZNF484-rs199826847C; and DCPS-rs1695739G] among persons with breast cancer versus the healthy controls even after Bonferroni corrections (p value <2.05 × 10-07). Although our patients' numbers were limited, the identified SNPs might shed some light on certain breast cancer-associated functional multigenic variations in Arab patients. We assert on the importance of more extensive large-scale analysis to confirm the candidate biomarkers and possible target genes of breast cancer among Arab ancestries.

Functional multigenic variations associated with hodgkin lymphoma.

INTRODUCTION: The current study aimed to describe genotypes associated with Hodgkin lymphoma (HL) in a cohort of Saudi and non-Saudi patients and discuss their possible susceptibility to HL. METHODS: We studied clinical, histopathological, and laboratory findings of HL patients admitted over 12 years duration, at King Fahd University Hospital, KSA. The genomic DNAs of HL patients (n = 61) and normal control subjects (n = 36) were extracted, and genotyping was performed using the Illumina human exome bead chip. Set of HL patients and set of normal controls were included in this study. RESULTS: A total of 35 DNA variants were found to be highly significant with the P-value <9.90 × 10-11 among 243 345 exonic biomarkers and obeying the Hardy-Weinberg equilibrium. Nine, MEGF11-rs150945752 (P-value 1.20 × 10-12 ), CACNA1I- s58055559 (P-value 1.93 × 10-12 ), DECR2-rs146760080 (P-value 2.19 × 10-12 ), STAB1-rs143894786 (P-value 2.45 × 10-12 ), ZNF526-rs144433879 (P-value 2.76 × 10-12 ), CPLANE1-rs200612080 (P-value 3.77 × 10-12 ), DLK1-rs1058009 (P-value 5.95 × 10-12 ), RTN4RL2-rs61745214 (P-value 7.71 × 10-12 ), and PGRMC1-rs145582672 (P-value 8.56 × 10-12 ), exonic variants on chromosomes 15, 22, and 16 were highly associated with HL cases. THE HIGHLY SIGNIFICANT HAPLOTYPES AT CHROMOSOME 3: rs143894786G; rs149982219G with P-value = 3.43 × 10-14 was found to be the risk haplotype for the HL patients. The opposite alleles at chromosome 3: rs143894786A; rs149982219G is protective with P-value = 2.46 × 10-12 . Maximum number of SNPs at the chromosome 19: rs144433879C; rs181265966G; rs201144421C; rs145591797G; rs200560875G; rs77270337G (risk P-value = 2.24 × 10-12 ) and its opposite allele rs144433879A; rs181265966A; rs201144421T; rs145591797A; rs200560875A; rs77270337A (protective P-value = 2.60 × 10-9 ) were found to be associated haplotype with the HL and controls, respectively, in Saudi population. CONCLUSION: Our study concludes that the HL is genetically heterogeneous with multigene causation.

Tyrosine kinase domain mutations of EGFR gene in head and neck squamous cell carcinoma.

BACKGROUND: Epidermal growth factor receptor (EGFR) is a commonly altered gene that is identified in various cancers, including head and neck squamous cell carcinoma (HNSCC). Therefore, EGFR is a promising molecular marker targeted by monoclonal antibodies and small molecule inhibitors targeting the tyrosine kinase (TK) domain. OBJECTIVE: The objective of this study was to investigate the spectrum of mutations in exons 18, 19, 20, and 21 of the EGFR gene in HNSCC patients. MATERIALS AND METHODS: This retrospective study included 47 confirmed HNSCC cases. Mutations in the TK domain, exons 18, 19, 20, and 21 of the EGFR gene, were detected by Scorpion® chemistry and ARMS® technologies on Rotor-Gene Q real-time polymerase chain reaction. RESULTS: The tumors exhibited EGFR-TK domain mutations in 57% of cases. Four cases of T790M mutations were reported for the first time among HNSCC patients. Out of the total mutations, L861Q (exon 21), exon 20 insertions and deletions of exon 19 accounted for the majority of mutations (21%, 19%, and 17%, respectively). EGFR mutation status was correlated with the higher grade (P=0.026) and advanced stage (P=0.034) of HNSCC tumors. CONCLUSION: Higher frequency of EGFR-TK domain mutations together with the presence of the T790M mutation suggests that identification of these mutations might streamline the therapy and provide a better prognosis in HNSCC cases.

Novel mutations of PIK3CA gene in head and neck squamous cell carcinoma.

BACKGROUND: HNSCC is the sixth most common human cancer globally. In Saudi Arabia, HNSCC accounts for seven percent of all newly diagnosed cancer cases. The PIK3CA is one of the most commonly mutated oncogene in human malignancies, including HNSCC. OBJECTIVE: The objective of this study is to identify mutations in exon 9 and exon 20 of the PIK3CA gene among Saudi HNSCC patients, determine the frequency of these mutations and correlate with clinical and pathological findings. METHODS: Histopathologically confirmed paraffin embedded HNSCC tumor tissues from 48 patients were obtained. Capillary sequencing method was used to sequence exons 9 and 20 of the PIK3CA gene. Concurrently, the expression analysis of the PIK3CA and PTEN genes were performed using real-time PCR. RESULTS: Sixty percent of the samples studied were of pharyngeal cancer. A total of seven mutations were identified in exons 9 and 20 of the PIK3CA gene in 14 HNSCC tumor tissue specimens. The seven mutations encompassed one hot spot mutation E542K, a common mutation T1025T and the five novel mutation comprising three missense and two silent mutations. Interestingly, eight out of the 14 samples with a mutation were of patients with pharyngeal cancer. CONCLUSION: PIK3CA gene plays a crucial role in carcinogenesis in general and HNSCC in particular. The identification of five novel mutations suggest that Saudis may have different frequencies of somatic genetic alterations that may influence HNSCC compared to other populations.