Browsing by Author "Onyia, Abimbola F."

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Abstract 999: Spectrum of germline BRCA1/2 gene mutations in Nigerian breast cancer patients
(Cancer Res (2025) 85 (8_Supplement_1):, 2025-04-21) Onyia, Abimbola F.; Jibrin, Paul; Olatunji-Agunbiade, Temitope; Oyekan, Ademola; Lawal, AbdulRazzaq; Alabi, Adewumi; Sowunmi, Anthonia C.; Aje, Eben A.; Ogunniyi, Oluwabusayo B.; Nkom, Ebenezer S.; De Campos, Opeyemi C.; Rotimi, Oluwakemi A.; Oyelade, Jelili O.; Rotimi, Solomon O.
Breast cancer (BC) is the leading cause of cancer-related deaths in Nigerian women, with triple-negative breast cancer (TNBC) being the most prevalent. The TNBC subtype is characterized by mutations in BRCA1 and BRCA2 genes, and germline pathogenic carriers of these mutations have an increased risk for BC. Despite these challenges, the prevalence and spectrum of BRCA1/2 pathogenic variants in the Nigerian population differ, and there is a margin in the local capacity to characterize these variations. Therefore, this study aimed to identify and characterize germline variations in BRCA 1/2 genes in Nigerian BC patients and healthy aged-matched controls to understand the genetic risk profiles of BC in this population. Forty-five BC patients were recruited across four major hospitals in Nigeria and aged-matched with 51 healthy female controls. DNA was extracted from blood samples, followed by targeted sequencing of BRCA 1/2 intronic and exonic regions using the Ampliseq for BRCA panel and the Illumina Miseq Platform. Variant calling was performed, and the clinical significance of identified variants was evaluated on the ClinVar and BRCA exchange databases. Variants of unknown significance (VUS) were assessed using known in silico prediction software, and haplotype analysis was carried out using the Haploview 4.2 software. Pathogenic variants were identified in 6.7% of cases, all exclusive to BC patients. These variants included two BRCA1 variants (3: c.133_134delAA (p.Lys45fs) and c.5324T>A (21: p.Met1775Lys), and one BRCA 2 variant (22: c.8817_8820del (p.Lys2939fs) all found in patients with the TNBC subtype. Additionally, 97 benign or likely benign BRCA1/2 variants were found in both BC and control groups, with notable variants such as the rs799917 identified as a surrogate indicator of ancestry. Eighteen VUS were identified, with four predicted to be damaging by three in silico prediction software. The results of haplotype analysis identified distinct BC haplotypes in Nigerian BC patients. The identification of BRCA1/2 pathogenic variants in Nigerian BC patients, especially those with TNBC, suggests a potential for targeted therapies, such as PARP inhibitors, to improve treatment outcomes in this population. This further highlights the need for increased population-specific screening and the integration of genetic screening into BC management strategies, which could facilitate early detection, personalized treatment plans, and genetic counseling for Nigerian BC patients.
Disparities in Allostatic Load Among Different Races: A Comprehensive Scoping Review
(Journal of Racial and Ethnic Health Disparities, 2025-10-01) Olowokere, Olanike Gloria; Olasehinde, Olutola Esther; Bisi‑Adeniyi, Titilayo Ifeoluwa; Onyia, Abimbola F.; De Campos, Opeyemi Christiana; Rotimi, Oluwakemi Anuoluwapo; Rotimi, Solomon Oladapo
Background Allostatic load measures the cumulative stress, and it varies across populations. Its accurate measurement among racial groups is essential for understanding the effects of chronic stress on health. This review is aimed at investigating disparities in allostatic load between races and exploring the underlying mechanisms driving these disparities. Methods A systematic search of literature was conducted, resulting in the inclusion of 296 relevant studies. These studies investigated a wide range of allostatic load biomarkers from the cardiovascular, metabolic, neuroendocrine, and immune systems. They involved diverse racial and ethnic populations with variations in age, gender, socioeconomic status (SES), and stress exposure. Results The review revealed disparities in allostatic load biomarkers across different population groups. The extensive examination of a wide range of biomarkers in the selected studies showed systolic and diastolic blood pressure (DBP), heart rate/pulse rate, high-density lipoprotein cholesterol, glycosylated hemoglobin (HbA1c), body mass index, total cholesterol (TC), C-reactive protein, and interleukin-6 (IL-6)/IL-6 receptor as the most frequently used biomarkers across populations. Socioeconomic status, age, racial discrimination, stressful life events, and adverse health outcomes were associated with allostatic load across different racial groups. Conclusion Disparities exist in previous studies on allostatic load due to differences in biomarker inclusion, calculation methods, study types, and populations studied. In addition, the roles of factors like social determinants of health, discrimination, and constitutive factors like genetics and age were discussed.
Photosensitizers in photodynamic therapy: An advancement in cancer treatment
(Results in Chemistry (Elsevier), 2024) Oluwajembola, Abimbola Mary; Cleanclay, Wisdom D.; Onyia, Abimbola F.; Chikere, Bruno N.; Zakari, Suleiman; Ndifreke, Ebong; De Campos, Opeyemi C.
Photodynamic therapy (PDT) is a clinically proven advancement in cancer treatment that has progressively gained consideration as a possible method of cancer treatment over time. This therapy, which involves the administration of a photosensitizing drug before activation of the drug with light from a source such as a laser to produce a cytotoxic effect, is minimally invasive and could increase the life expectancy of cancer patients. Cancer has been a major threat to human health, and it affects the quality of life of cancer patients as it is one of the topmost causes of mortality worldwide. The burden of cancer has been projected to increase to 2.1 million new cases and 1.4 million deaths in Africa by 2040. It is therefore expedient to put in more effort in proffering preventive measures, more efficient treatments, and possible cures for this disease. Recent studies have shown that many types of tumors can be destroyed using PDT. Tumor cells are destroyed via apoptosis, necrosis, and autophagy through some mechanisms in PDT. The successful outcome of this therapy depends greatly on three components which are photosensitizer (PS), light and molecular oxygen. Out of these three, photosensitizer is the most essential. Among the characteristics of a potent PS are the presence of a tetrapyrrole structure and the ability to initiate a photodynamic reaction when irradiated typically at a wavelength between 600 nm and 800 nm, although some PS can function effectively outside this range. This review highlights the effectiveness of PDT in the treatment of cancer and emphasizes the importance of PS, with more focus on those derived from natural sources, in determining the outcome of the therapy.
Screening of Germline BRCA1 and BRCA2 Variants in Nigerian Breast Cancer Patients
(Technology in Cancer Research & Treatment Volume 24, 2025) Onyia, Abimbola F.; Jibrin, Paul; Olatunji-Agunbiade, Temitope; Oyekan, Ademola; Lawal, AbdulRazzaq; Alabi, Adewumi; Sowunmi, Anthonia C.; Aje, Eben A.; Ogunniyi, Oluwabusayo B; Nkom, Ebenezer S.; De Campos, Opeyemi C.; Rotimi, Oluwakemi A.; Oyelade, Jelili O.; Rotimi, Solomon O.
Background: Breast cancer remains a leading cause of mortality among Nigerian women, with triple-negative breast cancer (TNBC) being particularly prevalent. Variations in BRCA1 and BRCA2 genes remain key risk factors for this disease. However, there are gaps in the frequency and spectrum of these variants in Nigerian populations, as well as a dearth in the local capacity to characterize these variations. Objective: This study aimed at identifying and characterizing the germline variations in BRCA1/2 in Nigerian breast cancer patients and healthy age-matched controls to understand the genetic risk profile of breast cancer in this population. Methods: A prospective case-control study was conducted involving 45 breast cancer patients and 51 controls recruited from four major hospitals. DNA was extracted from blood samples, followed by targeted sequencing of BRCA1/2 exonic and intronic regions using the Ampliseq BRCA panel and Illumina MiSeq platform. Variant calling was performed, clinical significance was evaluated on ClinVar and BRCA Exchange databases, and haplotype analysis was performed using NIH LDlink and Haploview 4.2 software. Results: Pathogenic BRCA1/2 variants were identified in 6.7% of breast cancer patients, all with TNBC and a family history of cancer. Two pathogenic BRCA1 variants were detected: a frameshift deletion BRCA1 c.133_134delAA (p.Lys45 fs) (rs397508857) and a missense variant BRCA1 c.5324T >A (p.Met1775Arg) (rs41293463). A BRCA2 frameshift deletion BRCA2 c.8817_8820del (p.Lys2939 fs) (rs397508010) was also identified. These variants were absent in controls. Haplotype analysis revealed distinct BRCA1 and BRCA2 haplotypes in the breast cancer group. Conclusion: This study identifies key BRCA1/2 pathogenic variants and unique haplotypes in Nigerian breast cancer patients, highlighting the need for population-specific genetic screening. Integrating genetic testing into breast cancer management strategies could facilitate early detection, personalized treatment planning, and genetic counseling in Nigeria.
Tumor-normal sequencing reveals novel TP53 germline and clinically actionable somatic mutations in Nigerian breast cancer patients
(Cancer Genetics Volumes 300–301, 2026) Onyia, Abimbola F.; Lawal, AbdulRazzaq; Ogo, Chidiebere; Nkom, Ebenezer S.; Lasebikan, Oluwakemi A.; Ayegbusi, Olaitan T.; De Campos, Opeyemi C.; Rotimi, Oluwakemi A.; Oyelade, Jelili O.; Aliyu, Usman M.; Iweala, Emeka E. J.; Rotimi, Solomon O.
Purpose Disparities in the care and management of breast cancer (BC) contribute to poor outcomes and limited access to precision oncology in Nigerian patients. Existing studies on Nigerian patients have largely been conducted abroad, restricting their direct application to local healthcare. This study addresses this gap through a locally led investigation of germline and somatic mutations using tumor-normal paired sequencing. Methods Forty-two female BC patients were recruited from teaching hospitals between January and April 2024. DNA was extracted from blood and matched fresh-frozen tumor tissue. Targeted sequencing of 50 cancer-related genes was performed with the Illumina AmpliSeq Cancer Hotspot Panel and MiSeq platform. Germline and somatic variants were identified through matched normal filtering, with oncogenic significance assessed using the ESCAT/ESMO Tier classification. Visualization was performed in R (v4.4.2) using the maftools package Results A germline TP53 pathogenic variant, TP53 c.694dupA (p.Ile232Asnfs) was identified in a 35-year-old triple-negative BC patient with recurrent metastatic disease, representing its first report as a germline alteration. Additionally, eighteen oncogenic/likely oncogenic somatic variants were detected, nine of which were actionable (Tier IIII). EGFR amplification was found in 7 % of patients, alongside copy number losses in genes including CDKN2A and KIT. Conclusion This study demonstrates the feasibility of localized tumor-normal sequencing in Nigerian BC patients, revealing actionable variants with clinical relevance. These findings highlight the need to integrate genomic profiling into routine cancer care and establish molecular tumor boards to advance precision oncology in Nigeria.
Tumor-normal sequencing reveals novel TP53 germline and clinically actionable somatic mutations in Nigerian breast cancer patients
(Cancer Genetics Volumes 300–301, 2026-01) Onyia, Abimbola F.; Lawal, AbdulRazzaq; Ogo, Chidiebere; Nkom, Ebenezer S.; Lasebikan, Nwamaka N.; Ayegbusi, Olaitan T.; De Campos, Opeyemi C.; Rotimi, Oluwakemi A; Oyelade, Jelili O.; Aliyu, Usman M.; Iweala, Emeka E.J.; Rotimi, Solomon O
Purpose Disparities in the care and management of breast cancer (BC) contribute to poor outcomes and limited access to precision oncology in Nigerian patients. Existing studies on Nigerian patients have largely been conducted abroad, restricting their direct application to local healthcare. This study addresses this gap through a locally led investigation of germline and somatic mutations using tumor-normal paired sequencing. Methods Forty-two female BC patients were recruited from teaching hospitals between January and April 2024. DNA was extracted from blood and matched fresh-frozen tumor tissue. Targeted sequencing of 50 cancer-related genes was performed with the Illumina AmpliSeq Cancer Hotspot Panel and MiSeq platform. Germline and somatic variants were identified through matched normal filtering, with oncogenic significance assessed using the ESCAT/ESMO Tier classification. Visualization was performed in R (v4.4.2) using the maftools package. Results A germline TP53 pathogenic variant, TP53 c.694dupA (p.Ile232Asnfs) was identified in a 35-year-old triple-negative BC patient with recurrent metastatic disease, representing its first report as a germline alteration. Additionally, eighteen oncogenic/likely oncogenic somatic variants were detected, nine of which were actionable (Tier IIII). EGFR amplification was found in 7 % of patients, alongside copy number losses in genes including CDKN2A and KIT. Conclusion This study demonstrates the feasibility of localized tumor-normal sequencing in Nigerian BC patients, revealing actionable variants with clinical relevance. These findings highlight the need to integrate genomic profiling into routine cancer care and establish molecular tumor boards to advance precision oncology in Nigeria.