Emerging proteomics biomarkers and prostate cancer burden in Africa

Proteomics of prostate cancer serum and plasma using low and high throughput approaches

Despite progress, MS-based proteomics in biofluids, especially blood, faces challenges such as dynamic range and throughput limitations in biomarker and disease studies. In this work, we used cutting-edge proteomics technologies to construct label-based and label-free workflows, capable of quantifying approximately 2,000 proteins in biofluids. With 70µL of blood and a single depletion strategy, we conducted an analysis of a homogenous cohort (n = 32), comparing medium-grade prostate cancer patients (Gleason score: 7(3 + 4); TNM stage: T2cN0M0, stage IIB) to healthy donors. The results revealed dozens of differentially expressed proteins in both plasma and serum. We identified the upregulation of Prostate Specific Antigen (PSA), a well-known biomarker for prostate cancer, in the serum of cancer cohort. Further bioinformatics analysis highlighted noteworthy proteins which appear to be differentially secreted into the bloodstream, making them good candidates for further exploration.

A Multi-Omics and Human Biomonitoring Approach to Assessing the Effectiveness of Fortified Balanced Energy-Protein Supplementation on Maternal and Newborn Health in Burkina Faso: A Study Protocol

Fortified balanced energy-protein (BEP) supplementation is a promising intervention for improving maternal health, birth outcomes and infant growth in low- and middle-income countries. This nested biospecimen sub-study aimed to evaluate the physiological effect of multi-micronutrient-fortified BEP supplementation on pregnant and lactating women and their infants. Pregnant women (15-40 years) received either fortified BEP and iron-folic acid (IFA) (intervention) or IFA only (control) throughout pregnancy. The same women were concurrently randomized to receive either a fortified BEP supplement during the first 6 months postpartum in combination with IFA for the first 6 weeks (i.e., intervention) or the postnatal standard of care, which comprised IFA alone for 6 weeks postpartum (i.e., control). Biological specimens were collected at different timepoints. Multi-omics profiles will be characterized to assess the mediating effect of BEP supplementation on the different trial arms and its effect on maternal health, as well as birth and infant growth outcomes. The mediating effect of the exposome in the relationship between BEP supplementation and maternal health, birth outcomes and infant growth were characterized via biomonitoring markers of air pollution, mycotoxins and environmental contaminants. The results will provide holistic insight into the granular physiological effects of prenatal and postnatal BEP supplementation.

Potential of miRNAs in Plasma Extracellular Vesicle for the Stratification of Prostate Cancer in a South African Population

Prostate cancer (PCa) is the most common cause of cancer death among African men. The analysis of microRNAs (miRNAs) in plasma extracellular vesicles (EVs) can be utilized as a non-invasive tool for the diagnosis of PCa. In this study, we used small RNA sequencing to profile miRNAs cargo in plasma EVs from South African PCa patients. We evaluated the differential expression of miRNAs between low and high Gleason scores in the plasma EVs of South African patients and in the prostatic tissue from data available in the Cancer Genome Atlas (TCGA) Data Portal. We identified 7 miRNAs differently expressed in both EVs and prostatic tissues. We evaluated their expression using qPCR in a larger cohort of 10 patients with benign prostatic hyperplasia (BPH) and 24 patients with PCa. Here, we reported that the ratio between two of these miRNAs (i.e., miR-194-5p/miR-16-5p) showed a higher concentration in PCa compared to BPH and in metastatic PCa compared to localized PCa. We explored for the first time the profiling of miRNAs cargo in plasma EVs as a tool for the identification of putative markers in the South African population. Our finding indicated the ratio miR-194-5p/miR-16-5p as a non-invasive marker for the evaluation of PCa aggressiveness in this population.

Perceptions and experiences of prostate cancer patients in a public tertiary hospital in urban South Africa

ABSTRACTProstate cancer is among the most prevalent forms of cancer worldwide and is reported to have the highest incidence, mortality, and 5-year prevalence rate of all cancers among men living in Africa. Despite this widespread burden in the African continent, little is known about the perspectives and experience of prostate cancer among African men. To further understand experiences among patients living in urban South Africa, we conducted in-depth, semi-structured qualitative interviews to examine the perceptions and experiences of 28 Black African prostate cancer patients receiving treatment at a major tertiary hospital in Johannesburg, South Africa. Our data explored four major areas of patients' experiences with prostate cancer: detection, diagnosis, treatment, and follow-up care. Our results showed that the experience of living with prostate cancer among low-income, Black South African men is a stressful and emotionally painful experience due in part to men feeling that they had insufficient knowledge about their own condition and feeling disempowered or ill-equipped to manage their cancer. These feelings were strongly associated with distrust or dissatisfaction with physicians and the health care system. Resilience factors include social support from family, friends, and religious communities, acceptance of their diagnosis, religion, and positive appraisals of their medical care.

Immune mechanisms behind prostate cancer in men of African ancestry: A review

BACKGROUND

Men of African ancestry (AA) with prostate cancer suffer from worse outcomes. However, a recent analysis of patients treated with the dendritic cell vaccine sipuleucel-T for prostate cancer suggested that AA patients could have improved outcomes relative to whites.

METHODS

We conducted a focused literature review of Medline-indexed articles and clinical trials listed on clinicaltrials.gov.

RESULTS

We identify several studies pointing to enrichment of inflammatory cellular infiltrates and cytokine signaling among AA patients with prostate cancer. We outline potential genomic and transcriptomic alterations that may contribute to immunogenicity. Last, we investigate differences in host immunity and vaccine responsiveness that may be enhanced in AA patients.

CONCLUSIONS

AA patients with prostate cancer may be enriched for an immunogenic phenotype. Dedicated studies are needed to better understand the immune mechanisms that contribute to existing cancer disparities and test immune-based therapies in this population.

The Practicality of the Use of Liquid Biopsy in Early Diagnosis and Treatment Monitoring of Oral Cancer in Resource-Limited Settings

An important driving force for precision and individualized medicine is the provision of tailor-made care for patients on an individual basis, in accordance with best evidence practice. Liquid biopsy(LB) has emerged as a critical tool for the early diagnosis of cancer and for treatment monitoring, but its clinical utility for oral squamous cell carcinoma (OSCC) requires more research and validation. Hence, in this review, we have discussed the current applications of LB and the practicality of its routine use in Africa; the potential advantages of LB over the conventional "gold-standard" of tissue biopsy; and finally, practical considerations were discussed in three parts: pre-analytic, analytic processing, and the statistical quality and postprocessing phases. Although it is imperative to establish clinically validated and standardized working guidelines for various aspects of LB sample collection, processing, and analysis for optimal and reliable use, manpower and technological infrastructures may also be an important factor to consider for the routine clinical application of LB for OSCC. LB is poised as a non-invasive precision tool for personalized oral cancer medicine, particularly for OSCC in Africa, when fully embraced. The promising application of different LB approaches using various downstream analyses such as released circulating tumor cells (CTCs), cell free DNA (cfDNA), microRNA (miRNA), messenger RNA (mRNA), and salivary exosomes were discussed. A better understanding of the diagnostic and therapeutic biomarkers of OSCC, using LB applications, would significantly reduce the cost, provide an opportunity for prompt detection and early treatment, and a method to adequately monitor the effectiveness of the therapy for OSCC, which typically presents with ominous prognosis.

Prostate Cancer Screening, Diagnostic, Treatment Procedures and Costs in Sub-Saharan Africa: A Situational Analysis

PURPOSE

Prostate cancer mortality is predicted to nearly double by 2040 in Sub-Saharan Africa (SSA). The lack of prostate cancer screening in SSA contributes to late-stage diagnosis, treatment delays, and poor survival among patients. We analyzed the availability and use of prostate cancer screening, diagnostic and treatment guidelines, procedures, and costs in few SSA countries to determine factors for consideration in the development of prostate cancer screening guidelines for SSA.

METHODS

We applied mixed methods approaches to collect data through an electronic survey administered to clinicians (oncologists, urologists, pathologists, nurses, and radiation oncologists) providing prostate cancer screening, diagnosis, and treatment services in multiple sub-Saharan countries.

RESULTS

Inconsistencies in respondents' understanding of the availability and use of prostate cancer screening guidelines in their countries were noted. Prostate Specific Antigen (PSA) and Digital Rectal Examination (DRE) were the most commonly available screening modalities. Available diagnostic procedures included a combination of prostate biopsies, transrectal ultrasonography, and DRE. Our study's data suggest that PSA and DRE exams are available for early diagnosis and screening procedures. Availability of treatment modalities with curative intent and costs for prostate cancer related procedures varied between and within countries.

CONCLUSIONS

PSA and DRE are available for detecting prostate cancer and may detect aggressive cancers early, leading to improved outcomes. However, PSA screening is also associated with overdiagnosis and over-treatment. National prostate cancer policies should consider health systems, evidence-based guidelines, population characteristics and healthcare financing to ensure access to clinically relevant and safe prostate cancer related care.

Proteomics Profiling to Distinguish DOCK8 Deficiency From Atopic Dermatitis

Dedicator of cytokinesis 8 deficiency is an autosomal recessive primary immune deficiency disease belonging to the group of hyperimmunoglobulinemia E syndrome (HIES). The clinical phenotype of dedicator of cytokinesis 8 (DOCK8) deficiency, characterized by allergic manifestations, increased infections, and increased IgE levels, overlaps with the clinical presentation of atopic dermatitis (AD). Despite the identification of metabolomics and cytokine biomarkers, distinguishing between the two conditions remains clinically challenging. The present study used a label-free untargeted proteomics approach using liquid-chromatography mass spectrometry with network pathway analysis to identify the differentially regulated serum proteins and the associated metabolic pathways altered between the groups. Serum samples from DOCK8 (n = 10), AD (n = 9) patients and healthy control (Ctrl) groups (n = 5) were analyzed. Based on the proteomics profile, the PLS-DA score plot between the three groups showed a clear group separation and sample clustering (R2 = 0.957, Q2 = 0.732). Significantly differentially abundant proteins (p < 0.05, FC cut off 2) were identified between DOCK8-deficient and AD groups relative to Ctrl (n = 105, and n = 109) and between DOCK8-deficient and AD groups (n = 85). Venn diagram analysis revealed a differential regulation of 24 distinct proteins from among the 85 between DOCK8-deficient and AD groups, including claspin, haptoglobin-related protein, immunoglobulins, complement proteins, fibulin, and others. Receiver-operating characteristic curve (ROC) analysis identified claspin and haptoglobin-related protein, as potential biomarkers with the highest sensitivity and specificity (AUC = 1), capable of distinguishing between patients with DOCK8 deficiency and AD. Network pathway analysis between DOCK8-deficiency and AD groups revealed that the identified proteins centered around the dysregulation of ERK1/2 signaling pathway. Herein, proteomic profiling of DOCK8-deficiency and AD groups was carried out to determine alterations in the proteomic profiles and identify a panel of the potential proteomics biomarker with possible diagnostic applications. Distinguishing between DOCK8-deficiency and AD will help in the early initiation of treatment and preventing complications.

Clinical Chemistry for Developing Countries: Mass Spectrometry

Early disease diagnosis is necessary to enable timely interventions. Implementation of this vital task in the developing world is challenging owing to limited resources. Diagnostic approaches developed for resource-limited settings have often involved colorimetric tests (based on immunoassays) due to their low cost. Unfortunately, the performance/sensitivity of such simplistic tests are often limited and significantly hinder opportunities for early disease detection. A new criterion for selecting diagnostic tests in low- and middle-income countries is proposed here that is based on performance-to-cost ratio. For example, modern mass spectrometry (MS) now involves analysis of the native sample in the open laboratory environment, enabling applications in many fields, including clinical research, forensic science, environmental analysis, and agriculture. In this critical review, we summarize recent developments in chemistry that enable MS to be applied effectively in developing countries. In particular, we argue that closed automated analytical systems may not offer the analytical flexibility needed in resource-limited settings. Alternative strategies proposed here have potential to be widely accepted in low- and middle-income countries through the utilization of the open-source ambient MS platform that enables microsampling techniques such as dried blood spot to be coupled with miniature mass spectrometers in a centralized analytical platform. Consequently, costs associated with sample handling and maintenance can be reduced by >50% of the total ownership cost, permitting analytical measurements to be operated at high performance-to-cost ratios in the developing world.

Cancer Omics in Africa: Present and Prospects

During the last century, cancer biology has been arguably one of the most investigated research fields. To gain deeper insight into cancer mechanisms, scientists have been attempting to integrate multi omics data in cancer research. Cancer genomics, transcriptomics, metabolomics, proteomics, and metagenomics are the main multi omics strategies used currently in the diagnosis, prognosis, treatment, and biomarker discovery in cancer. In this review, we describe the use of different multi omics strategies in cancer research in the African continent and discuss the main challenges facing the implementation of these approaches in African countries such as the lack of training programs in bioinformatics in general and omics strategies in particular and suggest paths to address deficiencies. As a way forward, we advocate for the establishment of an "African Cancer Genomics Consortium" to promote intracontinental collaborative projects and enhance engagement in research activities that address indigenous aspects for cancer precision medicine.

Identification of Diagnostic Biomarkers of Osteoarthritis Based on Multi-Chip Integrated Analysis and Machine Learning

The pathogenesis of osteoarthritis (OA) is still unclear. It is therefore important to identify relevant diagnostic marker genes for OA. We performed an integrated analysis with multiple microarray data cohorts to identify potential transcriptome markers of OA development. Further, to identify OA diagnostic markers, we established gene regulatory networks based on the protein-protein interaction network involved in these differentially expressed genes (DEGs). Using support vector machine (SVM) pattern recognition, a diagnostic model for OA prediction and prevention was established. Kyoto Encyclopedia of Genes and Genomes pathway analysis revealed that 190 DEGs were mainly enriched in pathways like the tumor necrosis factor signaling pathway, interleukin-17 signaling pathway, mitogen-activated protein kinase signaling pathway, nuclear factor kappa-light-chain-enhancer of activated B cells signaling pathway, and osteoclast differentiation. Eight hub genes (POSTN, MMP2, CTSG, ELANE, COL3A1, MPO, COL1A1, and COL1A2) were considered potential diagnostic biomarkers for OA, the area under curve (AUC) was >0.95, which showed high accuracy. The sensitivity and specificity of the SVM model of OA based on these eight genes reached 100% in multiple external verification cohorts. Our research provides a theoretical basis for OA diagnosis for clinicians.

The Prospect and Challenges to the Flow of Liquid Biopsy in Africa

Liquid biopsy technologies have the potential to transform cancer patient management as it offers non-invasive diagnosis and real-time monitoring of disease progression and treatment responses. The use of liquid biopsy for non-invasive cancer diagnosis can have pivotal importance for the African continent where access to medical infrastructures is limited, as it eliminates the need for surgical biopsies. To apply liquid biopsy technologies in the African setting, the influence of environmental and population genetic factors must be known. In this review, we discuss the use of circulating tumor cells, cell-free nucleic acids, extracellular vesicles, protein, and other biomolecules in liquid biopsy technology for cancer management with special focus on African studies. We discussed the prospect, barriers, and other aspects that pose challenges to the use of liquid biopsy in the African continent.

Therapy of Prostate Cancer by Nanoyam Polysaccharide

We evaluated the effect and mechanism of yam polysaccharide on the proliferation of the prostatic cancer cell line and tumor-bearing mice. The effect of nanoyam polysaccharide on prostatic cancer cell line PC-3 was measured using the scratch adhesion test and flow cytometry. The growth effect induced by nanoyam polysaccharide was detected with the CCK-8 test. The levels of caspase-3 protein were determined with Western blot. In our data, nanoyam polysaccharide presented inhibitory effect on the proliferation of PC-3. The scratch adhesion test showed that the rate of wound healing in the intervention group was significantly lower than that in the control group (p<0.05). Flow cytometry assay showed that, after treatment with nanoyam polysaccharide, the apoptosis rate in the intervention group was significantly lower than that in the control group (45.8%±2.6%, 25.8%±3.1%; p<0.05). Western blot assay showed upregulated levels of caspase-3 in the intervention group, compared to the control group (p<0.05). Our results suggested that nanoyam polysaccharide strongly suppressed the growth of prostatic cancer by inducing the overexpression of caspase-3 and may be a potent anticancer strategy.

The dentist-scientist career pathway in Africa: opportunities and obstacles

The future of evidence-based dentistry in developing Africa heavily depends on a sustainable establishment of a vibrant dentist-scientist workforce. A dentist scientist is saddled with the responsibility of carrying out robust cutting edge research projects that are inspired by clinical experience. Currently, there are no pipelines in place to systematically train such dentists, neither are there programs in place to allow trained African dentists choose such a career pathway. A dentist-scientist is a person who studied oral, dental, maxillofacial (or craniofacial) diseases, prevention, and population sciences (obtaining a medical degrees such as bachelor of dental surgery [BDS] or BChD) alone; or in combination with other advanced degrees such as doctor of dental surgery (DDS)/doctor of philosophy (PhD) or BDS/PhD. This situation has resulted in overdependence of African clinical practice on research findings from technologically advanced Western countries and a decline in clinical research capacity building. The career path of a dentist-scientist should involve research along the spectrum of basic biomedical sciences, translational, clinical and public health sciences. There are several factors responsible for the ultra-low count of dentist-scientist in the heterogeneous African communities such as: poor biomedical research infrastructure; lack of funding; absence of structured dentist scientist career pathways; lack of personnel, inter alia. Hence, this review hopes to discuss the opportunities of setting up a dentist-scientist training pathway in Africa (as obtains in most developed world settings), identify opportunities and prospects of developing an African dentist-scientist workforce, and finally discuss the challenges involved.

Preliminary study on ultrasound-guided prostate biopsy specimen scores

Prostate cancer (PCa) is the second most frequently diagnosed cancer in males worldwide and resulted in ~258,000 cases of cancer-associated mortality in 2008. The present study visually determined the pathology scores of PCa specimens by taking into account five characteristics, including the hardness, color, plumpness, transparency and uniformity of specimens. The current study also aimed to identify the association between pathology scores and prostate specific antigen (PSA) levels, in order to reduce the complications caused by punctures and elevate the specimen positive rates. A total of 1,608 specimens from 268 patients were analyzed by one sonographer, one urologist and one pathologist. A standard pathological examination was performed on the PCa biopsy specimens and specimen scores were recorded under double-blinded conditions. A receiver operator characteristic curve identified a linear correlation between the visually determined score and PSA levels (r=0.255; P<0.001). Furthermore, logistic regression analysis indicated that the visually determined score and PSA were correlated with the diagnosis of PCa. Additionally, the authenticity of the visually determined score was higher than PSA in the diagnosis of PCa, with the best sensitivity and specificity of the visually determined scores used to predict PCa being 0.817 and 0.931, respectively.

[Sanggenon C induces apoptosis of prostate cancer PC3 cells by activating caspase 3 and caspase 9 pathways]

OBJECTIVE

To investigate the effects of Sanggenon C in inducing apoptosis of prostate cancer PC3 cell line and explore the underlying mechanism.

METHODS

The proliferation of PC3 cells treated for 24 h with 1, 5, 20, 50, and 100 µmol/L sanggenon C or treated with 20 µmol/L Sanggenon C for 0, 6, 12, 24 and 48 h was evaluated using MTT assay. Flow cytometry was performed for analysis of apoptosis of PC3 cells after exposure to sanggenon C with different treatment protocols, and the activity of caspase 3 was detected using spectrofluorometry. The inhibitory effect of sanggenon C on PC3 cells pretreated with DMSO, z-DEVD-fmk, z-LEHD-fmk or z-IETD-fmk for 1 h was detected by MTT assay.

RESULTS

Sanggenon C inhibited the proliferation of PC3 cells in a dose- and time-dependent manner (P<0.05 except for 1 µmol/L group) with a 24-h IC₅₀ of 18.76 µmol/L. Sanggenon C at 20 µmol/L caused inhibition rates of PC3 cells of 10.57%, 27.09%, 51.88%, 80.73% and 87.99% after treatment for 6, 12, 24, 48, and 72 h, respectively (P<0.05), and resulted in apoptosis rates of 7.43%, 20.91% and 37.56% at 12 h, 24 h and 48 h, respectively. Sanggenon C significantly increased caspase-3 activity in the cells, and its effect on PC3 cell proliferation was partially reversed by caspase 3 and caspase 9 inhibitors.

CONCLUSION

Sanggenon C can dose-dependently induce growth inhibition and apoptosis of PC3 cells possibly by activating caspase 9 and caspase 3 pathways.

Prognostic role of long non-coding RNA TUG1 expression in various cancers: a meta-analysis

Several studies were conducted to explore the prognostic role of long non-coding RNA taurine upregulated gene 1 (lncRNA TUG1) expression in various cancers, with contradictory. This study aims to summarize the prognostic role of lncRNA TUG1 expression in various cancers. Embase, PubMed and Cochrane Library were completely retrieved. The cohort studies focusing on the prognostic role of lncRNA TUG1 expression in various cancers were eligible. The endpoints were overall survival (OS) and clinicopathological parameters. 9 studies involving a total of 1,078 patients were identified. The results showed that high lncRNA TUG1 expression was obviously associated with worse OS when compared to the low lncRNA TUG1 expression (HR = 1.37, 95% CI = 1.07–1.76, P = 0.01; I² = 85%). However, No distinct relationship was observed between the lncRNA TUG1 expression and age (OR = 0.99, 95% CI = 0.76–1.28, P = 0.92; I2 = 4%), gender (OR = 0.92, 95% CI = 0.70–1.22, P = 0.57; I² = 0%), diameter (OR = 0.83, 95% CI = 0.34–2.01, P = 0.67; I² = 85%), smoking (OR = 1.09, 95% CI = 0.37–3.21, P = 0.87; I² = 73%), TNM stage (OR = 0.60, 95% CI = 0.25–1.43, P = 0.25; I² = 86%) and lymph node metastasis (OR = 1.07, 95% CI = 0.47–2.45, P = 0.87; I² = 86%). In conclusion, it was revealed that high lncRNA TUG1 expression is an unfavorable predictor of OS in patients with cancers, and lncRNA TUG1 expression is a promising prognostic biomarker for various cancers.