Shedding light on the dark genome: Insights into the genetic, CRISPR-based, and pharmacological dependencies of human cancers and disease aggressiveness.

Investigating the human genome is vital for identifying risk factors and devising effective therapies to combat genetic disorders and cancer. Despite the extensive knowledge of the "light genome", the poorly understood "dark genome" remains understudied. In this study, we integrated data from 20,412 protein-coding genes in Pharos and 8,395 patient-derived tumours from The Cancer Genome Atlas (TCGA) to examine the genetic and pharmacological dependencies in human cancers and their treatment implications. We discovered that dark genes exhibited high mutation rates in certain cancers, similar to light genes. By combining the drug response profiles of cancer cells with cell fitness post-CRISPR-mediated gene knockout, we identified the crucial vulnerabilities associated with both dark and light genes. Our analysis also revealed that tumours harbouring dark gene mutations displayed worse overall and disease-free survival rates than those without such mutations. Furthermore, dark gene expression levels significantly influenced patient survival outcomes. Our findings demonstrated a similar distribution of genetic and pharmacological dependencies across the light and dark genomes, suggesting that targeting the dark genome holds promise for cancer treatment. This study underscores the need for ongoing research on the dark genome to better comprehend the underlying mechanisms of cancer and develop more effective therapies.

Proteogenomic analysis of pancreatic cancer subtypes.

Pancreatic cancer remains a significant public health problem with an ever-rising incidence of disease. Cancers of the pancreas are characterised by various molecular aberrations, including changes in the proteomics and genomics landscape of the tumour cells. Therefore, there is a need to identify the proteomic landscape of pancreatic cancer and the specific genomic and molecular alterations associated with disease subtypes. Here, we carry out an integrative bioinformatics analysis of The Cancer Genome Atlas dataset, including proteomics and whole-exome sequencing data collected from pancreatic cancer patients. We apply unsupervised clustering on the proteomics dataset to reveal the two distinct subtypes of pancreatic cancer. Using functional and pathway analysis based on the proteomics data, we demonstrate the different molecular processes and signalling aberrations of the pancreatic cancer subtypes. In addition, we explore the clinical characteristics of these subtypes to show differences in disease outcome. Using datasets of mutations and copy number alterations, we show that various signalling pathways previously associated with pancreatic cancer are altered among both subtypes of pancreatic tumours, including the Wnt pathway, Notch pathway and PI3K-mTOR pathways. Altogether, we reveal the proteogenomic landscape of pancreatic cancer subtypes and the altered molecular processes that can be leveraged to devise more effective treatments.

Pigs as a potential source of emerging livestock-associated Staphylococcus aureus in Africa: a systematic review.

OBJECTIVE: To assess the emergence of livestock-associated Staphylococcus aureus including methicillin-resistant S. aureus (MRSA) in the pig and pork production systems in Africa for the past two decades. METHODS: PubMed and African Journals OnLine were searched for relevant primary studies from 2000 to 2019 using standardized key words. In total, 19 eligible articles were included in this review. RESULTS: The prevalence of S. aureus including MRSA ranged from 0% to 55% among live pigs and raw pork, and from 9.4% to 30.8% among pig farm and abattoir workers. Risk factors associated with S. aureus carriage among workers were: male gender, working in an abattoir, and medical-related occupation of a household member. S. aureus and MRSA from pigs and pork production systems in Africa are potentially pathogenic with diverse spa types and clonal complexes, with genes encoding antimicrobial resistance, heavy metal resistance, and virulence factors including secreted and enterotoxins, proteases and immune evasion cluster. The typical livestock-associated S. aureus CC398 and mecC genes were reported in two studies. CONCLUSION: Pigs are a potential source of the emerging livestock-associated S. aureus in Africa. Continued monitoring using a 'One Health' approach is recommended for effective infection prevention and control of these infections in Africa.

High ELF4 expression in human cancers is associated with worse disease outcomes and increased resistance to anticancer drugs.

The malignant phenotype of tumour cells is fuelled by changes in the expression of various transcription factors, including some of the well-studied proteins such as p53 and Myc. Despite significant progress made, little is known about several other transcription factors, including ELF4, and how they help shape the oncogenic processes in cancer cells. To this end, we performed a bioinformatics analysis to facilitate a detailed understanding of how the expression variations of ELF4 in human cancers are related to disease outcomes and the cancer cell drug responses. Here, using ELF4 mRNA expression data of 9,350 samples from the Cancer Genome Atlas pan-cancer project, we identify two groups of patient's tumours: those that expressed high ELF4 transcripts and those that expressed low ELF4 transcripts across 32 different human cancers. We uncover that patients segregated into these two groups are associated with different clinical outcomes. Further, we find that tumours that express high ELF4 mRNA levels tend to be of a higher-grade, afflict a significantly older patient population and have a significantly higher mutation burden. By analysing dose-response profiles to 397 anti-cancer drugs of 612 well-characterised human cancer cell lines, we discover that cell lines that expressed high ELF4 mRNA transcript are significantly less responsive to 129 anti-cancer drugs, and only significantly more response to three drugs: dasatinib, WH-4-023, and Ponatinib, all of which remarkably target the proto-oncogene tyrosine-protein kinase SRC and tyrosine-protein kinase ABL1. Collectively our analyses have shown that, across the 32 different human cancers, the patients afflicted with tumours that overexpress ELF4 tended to have a more aggressive disease that is also is more likely more refractory to most anti-cancer drugs, a finding upon which we could devise novel categorisation of patient tumours, treatment, and prognostic strategies.

Integrated molecular characterisation of the MAPK pathways in human cancers reveals pharmacologically vulnerable mutations and gene dependencies.

The mitogen-activated protein kinase (MAPK) pathways are crucial regulators of the cellular processes that fuel the malignant transformation of normal cells. The molecular aberrations which lead to cancer involve mutations in, and transcription variations of, various MAPK pathway genes. Here, we examine the genome sequences of 40,848 patient-derived tumours representing 101 distinct human cancers to identify cancer-associated mutations in MAPK signalling pathway genes. We show that patients with tumours that have mutations within genes of the ERK-1/2 pathway, the p38 pathways, or multiple MAPK pathway modules, tend to have worse disease outcomes than patients with tumours that have no mutations within the MAPK pathways genes. Furthermore, by integrating information extracted from various large-scale molecular datasets, we expose the relationship between the fitness of cancer cells after CRISPR mediated gene knockout of MAPK pathway genes, and their dose-responses to MAPK pathway inhibitors. Besides providing new insights into MAPK pathways, we unearth vulnerabilities in specific pathway genes that are reflected in the re sponses of cancer cells to MAPK targeting drugs: a revelation with great potential for guiding the development of innovative therapies.

Molecular Detection of Fusion Oncogenes in Zambian Patients with Acute Lymphoblastic Leukemia.

INTRODUCTION: Chromosomal aberrations play a significant role in the pathogenesis of acute lymphoblastic leukemia (ALL) with prognostic and therapeutic implications. Despite the availability of molecular tools, low-resource settings struggle to diagnose the disease due to limited diagnostic capacity. The objective of this study was to detect common chromosomal aberrations in patients with ALL attending the University Teaching Hospital (UTH) in Lusaka, Zambia. MATERIALS AND METHODS: In this prospective study, 19 blood samples from patients with ALL were screened for the presence of BCR-ABL, E2A-PBX1, MLL-AF4, and ETV6-RUNX1 fusion oncogenes using reverse transcriptase-polymerase chain reaction assay. Blood counts and clinical characteristics of patients were also assessed. RESULTS: The age of patients ranged from 1½ to 72 years and comprised 57.9% of males and 42.1% of females. The majority of these patients were children (68%), and adults only comprised 32%. Only BCR-ABL and E2A-PBX1 oncogenes were detected in 3/19 of cases. The BCR-ABL gene was detected in a 4-year-old female child and a 15-year-old child. Both cases were associated with hepatomegaly and anemia coupled with low hemoglobin, white blood cell, and platelet counts. E2A-PBX1 was detected in a 12-year-old child with lymphadenopathy and splenomegaly, coupled with low hemoglobin, white blood cell, and platelet counts. All the three patients who harbored these fusion oncogenes died. CONCLUSION: This is the first study from Zambia to investigate the presence of fusion oncogenes in leukemia patients, which were found only among the older children population. Based on these findings, we recommend that molecular diagnosis be made a priority for the younger leukemia patient population at UTH.

Avian Influenza Viruses Detected in Birds in Sub-Saharan Africa: A Systematic Review.

In the recent past, sub-Saharan Africa has not escaped the devastating effects of avian influenza virus (AIV) in poultry and wild birds. This systematic review describes the prevalence, spatiotemporal distribution, and virus subtypes detected in domestic and wild birds for the past two decades (2000-2019). We collected data from three electronic databases, PubMed, SpringerLink electronic journals and African Journals Online, using the Preferred Reporting Items for Systematic reviews and Meta-Analyses protocol. A total of 1656 articles were reviewed, from which 68 were selected. An overall prevalence of 3.0% AIV in birds was observed. The prevalence varied between regions and ranged from 1.1% to 7.1%. The Kruskal-Wallis and Wilcoxon signed-rank sum test showed no significant difference in the prevalence of AIV across regions, χ2(3) = 5.237, p = 0.1553 and seasons, T = 820, z = -1.244, p = 0.2136. Nineteen hemagglutinin/neuraminidase subtype combinations were detected during the reviewed period, with southern Africa recording more diverse AIV subtypes than other regions. The most detected subtype was H5N1, followed by H9N2, H5N2, H5N8 and H6N2. Whilst these predominant subtypes were mostly detected in domestic poultry, H1N6, H3N6, H4N6, H4N8, H9N1 and H11N9 were exclusively detected in wild birds. Meanwhile, H5N1, H5N2 and H5N8 were detected in both wild and domestic birds suggesting circulation of these subtypes among wild and domestic birds. Our findings provide critical information on the eco-epidemiology of AIVs that can be used to improve surveillance strategies for the prevention and control of avian influenza in sub-Saharan Africa.

Leucocytosis and Asymptomatic Urinary Tract Infections in Sickle Cell Patients at a Tertiary Hospital in Zambia.

Sickle cell anaemia (SCA) is an inherited disease resulting from mutations in the ß-globin chain of adult haemoglobin that results in the formation of homozygous sickle haemoglobin. It is associated with several complications including an altered blood picture and damage in multiple organs, including the kidneys. Kidney disease is seen in most patients with SCA and may affect glomerular and/or tubular function, thereby putting these patients at risk of urinary tract infections. However, there is a paucity of data on the prevalence of urinary tract infections (UTIs) among SCA patients in Zambia. This study aimed to determine the prevalence of UTIs and haematological and kidney function profiles among SCA patients at the University Teaching Hospitals, Lusaka, Zambia. This was a cross-sectional study conducted between April and July 2019 involving 78 SCA patients who presented at the UTH. Blood and midstream urine samples were collected from each participant using the standard specimen collection procedures. Full blood counts and kidney function tests were determined using Sysmex XT-4000i haematology analyser and the Pentra C200 by Horiba, respectively. Bacterial profiles of the urine samples were determined using conventional microbiological methods. We found that all the measured patients' haemoglobin (Hb) levels fell below the WHO-recommended reference range with a minimum of 5 g/dl, a maximum of 10.5 g/dl, and a mean of 8 ± 1 g/dl. Fifty percent of the participants had moderate anaemia, while the other 50% had severe anaemia. The minimum WBC count of the participants was 0.02 × 109/L with a maximum of 23.36 × 109/L and a mean of 13.48 ± 3.87 × 109/L. Using the one-way analysis of variance test, we found no significant difference in mean WBC count and Hb concentration across various age-group categories that we defined. Bacteriuria was found in 25% of participants. The most common bacterial isolates were Staphylococcus aureus (32%) and coagulase-negative Staphylococci (32%). Klebsiella pneumoniae was 16%. We found no significant association between bacterial isolates and white blood cell count, age groups, sex, and anaemia severity p = 0.41. None of the participants were diagnosed with kidney disease. There was a high prevalence of asymptomatic UTIs among SCA patients at UTH, which, when coupled with the marked leukocytosis and anaemia, may negatively impact the clinical outcome of the patients. Therefore, we recommend close monitoring of sickle cell patients in Zambia for such conditions to improve patients' outcomes.

The Use of Dried Blood Spots: A Potential Tool for the Introduction of a Neonatal Screening Program for Sickle Cell Anemia in Zambia.

CONTEXT: Sickle cell disease is a group of hemoglobin (Hb) disorders resulting from the inheritance of the sickle ß-globin gene. It is the most common pathological Hb mutation worldwide with 75% being born in Sub-Saharan Africa. AIMS: This study aims to determine if dried blood spots (DBSs) can be used for diagnosis of sickle cell in newborns. In Zambia, there is no neonatal screening program for sickle cell anemia (SCA), yet it has been proved that early diagnosis by newborn screening (NBS) using DBSs and access to comprehensive care results in survival to adulthood of over 96% of sickle cell patients. SETTINGS AND DESIGN: A cross-sectional study was carried out at the University Teaching Hospital to determine whether DBSs can be used to diagnose sickle cell using Hb electrophoresis. SUBJECTS AND METHODS: Results from DBSs stored for 2 weeks were then compared to those obtained using freshly collected whole blood. STATISTICAL ANALYSIS USED: To evaluate performance characteristics, the following values were used: true positive, false positive, true negative, and false negative. RESULTS: Ninety-seven participants were included in this study. DBSs had a sensitivity of 100%, a specificity of 94.7%, positive predictive value of 96.7%, negative predictive value of 100%, overall efficiency of 97.9%, and a Kappa r2, P < 0.0001 in comparison to fresh whole blood which we used as the gold standard. CONCLUSIONS: The use of DBSs can be recommended for NBS of SCA in Zambia due to its high sensitivity, specificity, and stability of hemoglobin.

Performance Characteristics of Kidney Injury Molecule-1 In Relation to Creatinine, Urea, and Microalbuminuria in the Diagnosis of Kidney Disease.

CONTEXT: The diagnosis and evaluation of impaired renal function remains a challenge owing to lack of reliable biomarker for assessment of kidney function. The existing panel of biomarkers currently displays several limitations, and recently kidney injury molecule-1 (KIM-1) has been suggested as a sensitive biomarker of renal function and proposed to enter clinical practice. AIMS: This study was conducted to determine the diagnostic value of serum creatinine, urea, and microalbuminuria (MAU) in relation to the novel biomarker, KIM-1. MATERIALS AND METHODS: Serum creatinine, urea, MAU, and KIM-1 were measured in forty individuals with and forty without kidney disease. Data were analyzed using multivariate methods of assessing diagnostic efficiency, test agreement, condition effects, and variability. RESULTS: The area under the receiver-operator characteristic curve revealed a diagnostic advantage of creatinine (0.924 ± 0.0066) and urea (0.925 ± 0.0068) over MAU (0.880 ± 0.078) and KIM-1 (0.35 ± 0.124). Overall diagnostic efficiency was higher for creatinine and urea (89.5% and 90.9%, respectively), followed by MAU (85.7%) and then KIM-1 (56.3%). Logistic regression analysis showed that creatinine and urea (R2 = 0.75 and R2 = 0.72, respectively, P < 0.001 for both) were better predictors of kidney disease than MAU (R2 = 0.64, P < 0.001) and KIM-1 (R2 = 0.046, P = 0.116). Further analysis of agreement showed that urea had an excellent agreement with creatinine (kappa r = 0.835, P < 0.001), with KIM-1 (kappa r = -0.198, P = 0.087) showing a poor agreement with creatinine. CONCLUSION: Our results indicate that elevated serum creatinine and urea above specific cutoff points reliably identifies patients with acute kidney injury or chronic kidney disease. However, more researches are warranted to further validate the diagnostic efficiency and application of MAU and for KIM-1 before its implementation in clinical practice.

Kidney injury molecule-1 and microalbuminuria levels in Zambian population: biomarkers of kidney injury.

INTRODUCTION: Kidney injury affects renal excretion of plasma analytes and metabolic waste products with grave pathologic consequences. Early detection, thus of kidney injury is essential for injury specific intervention that may avert permanent renal damage and delay progression of kidney injury. We aimed to evaluate Kidney Injury Molecule-1 (KIM-1) and Microalbuminuria (MAU), as biomarkers of kidney injury, in comparison with creatinine. METHODS: We compared the levels of urine MAU, urine KIM-1 and other plasma biochemical tests in specimens from 80 individuals with and without kidney disease. RESULTS: We found no difference in KIM-1 levels between the kidney disease group (2.82± 1.36ng/mL) and controls (3.29 ± 1.14ng/mL), p = 0.122. MAU was higher in participants with kidney disease (130.809± 84.744 µg/mL) than the controls (15.983± 20.442µg/mL), p ?0.001. KIM-1 showed a weak negative correlation with creatinine (r = -0.279, p = 0.09), whereas MAU was positively correlated with creatinine in participants with kidney disease with statistical significance (r = 0.556, p = 0.001). CONCLUSION: The study demonstrated that in Zambian setting MAU and creatinine are sensitive biomarkers in the diagnosis of kidney damage. We moreover propose further evaluation of KIM-1 as a biomarker of kidney injury.