Circulating Cancer Associated Fibroblasts and Circulating Tumour Stem Cells: The Symbiotic Siblings and Potential Drug Targets
Mirza S https://orcid.org/0000-0003-0870-0901 1,2,3 Jain N https://orcid.org/0000-0001-9458-6927 2, Rawal R https://orcid.org/0000-0002-7985-1187 2, Penny C https://orcid.org/0000-0003-4429-5712 1
1Department of Internal Medicine, Oncology Division, Faculty of Health Sciences, University of Witwatersrand, Johannesburg, South Africa
2Department of Life Science, School of Sciences, Gujarat University, Ahmedabad, Gujarat, India
3Department of Cancer Biology, The Gujarat Cancer and Research Institute, Ahmedabad, Gujarat, India
Background: Tumour-microenvironment (TME) significantly influences the behaviour of circulating tumour stem cells (CTSCs). Cancer-associated fibroblasts (CAFs) within TME, are known for expediting metastasis through mechanisms yet to be elucidated. CAFs, through cytokine secretion and acting as an “incubator”, confer survival advantage to CTSCs by evading immune system; thus considered as a target in diagnostics and therapeutics. This study aims to develop minimally-invasive diagnostic and prognostic modalities, for frequent monitoring of treatment response as a liquid-biopsy approach in order to improve clinical outcome for lung adenocarcinomas.
Methods: Pleurospheres (PS) were generated in serum-free media and their chemotherapeutic resistance was evaluated by 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Epithelial to mesenchymal transition (EMT) was characterized by western-blot, immunofluorescence and immunocytochemistry. Furthermore, cancer stem cells and epithelial markers were assessed using flow cytometry. Circulating-CAFs (cCAFs) were confirmed in the blood of non-small cell lung cancer patients through western-blot and quantitative reverse transcription polymerase chain reaction (qRT-PCR), using α-smooth muscle actin.
Results: PS exhibited enhanced self-renewal, suggesting their stem-like characteristics. MTT assay revealed intrinsic drug-resistance to 100µM Gemcitabine, with elevated expression of multi-drug resistance markers by qRT-PCR. CTSCs unveiled Vimentin predominance over E-cadherin, indicative of EMT. Flow cytometry revealed higher CD44(+)/CD24(-) population expressing cytokeratin (5.6%±0.3%) and epithelial cell adhesion molecule (0.5%±0.4%), suggesting CTSCs presence. Proteomic and genomic expression of cCAFs was significantly higher in patients than healthy individuals (p<0.0001). Notably, significant trend was observed across different stages (p < 0.014), implying a potential role in disease progression.
Conclusion: Companion biomarkers, cCAFs along with CTSCs, could enhance early detection and prove to be an efficient biomarker for metastasis as a new paradigm shift in treatment monitoring.
Keywords: Cancer associated fibroblasts, circulating cancer stem cells, liquid biopsy, lung adenocarcinoma
Comparison of the proteome of Huh-7 cells transfected with replication-competent different subgenotypes of Hepatitis B Virus prevailing in and outside sub-Saharan Africa
Kiyasha Padarath https://orcid.org/0000-0002-5969-9392 1, Aurelie Deroubaix https://orcid.org/0000-0002-4150-3072 1,2, Anna Kramvis https://orcid.org/0000-0001-6006-3765 1
1Hepatitis Virus Diversity Unit, Department of Internal Medicine, School of Clinical Medicine, Faculty of Health Science, University of Witwatersrand
2Life Sciences Imaging Facility, Faculty of Health Sciences, University of the Witwatersrand
Background: Hepatitis B Virus (HBV) is classified into nine distinct genotypes, and at least 35 subgenotypes. In sub-Saharan Africa (sSA), subgenotypes A1, D3, and E prevail. Genetic variations between subgenotypes can contribute to differences in pathogenesis and progression to hepatocellular carcinoma (HCC). Individuals infected with subgenotype A1 have an increased risk of HCC compared to those infected with other subgenotypes. The effect of subgenotypes on protein expression and host signalling has not been studied.
Materials and methods: We used mass spectrometry to analyse the proteome of Huh-7 cells transfected with replication-competent clones of subgenotypes prevailing in sSA compared to A2, prevailing outside Africa.
Results: Five days post-transfection, proteomic analysis, revealed significantly differentially expressed proteins in cells transfected with sSA subgenotypes compared to A2 (p < 0.05). These differentially expressed proteins were classified into the top 10 pathways shared between subgenotypes A1, A2, D3, and E. Amongst these 10 pathways, proteins involved in inflammation, T-cell activation, and apoptosis were significantly decreased in sSA subgenotypes compared to A2. Furthermore, RAS proteins were significantly upregulated (1.5-fold increase) in A1 compared to other subgenotypes.
Conclusion: The downregulation of pro-inflammatory cytokines and apoptotic pathways helps promote the survival of HBV-infected hepatocytes, possibly leading to persistence in sSA subgenotypes. Two of the main cellular pathways involving RAS proteins are MAPK and PI3K, which are signalling pathways that regulate cell growth and metabolism. The upregulated RAS proteins: GNB1, RhoC, and Rap1 have been documented as oncoproteins in various cancers and could contribute to the vincreased hepatocarcinogenic potential of A1.
Keywords: Hepatitis B Virus, subgenotypes, hepatocellular carcinoma
A Study of Adult Aortic Valve disease at a Peri-Urban Tertiary Hospital
Jingisile Dlamini https://orcid.org/0009-0000-5918-1940 1 and Ruchika Meel https://orcid.org/0000-0002-1405-4259 1
1Department of Internal Medicine, School of Clinical Medicine, Faculty of Health Sciences, University of the Witwatersrand
Background
Aortic valve disease is an important cause of morbidity and mortality globally. Data regarding aortic valve disease remains understudied in Africa. Herein, we sought to describe the current characteristics of patients with aortic valve disease in a peri-urban hospital setting.
Method
In this descriptive cross-sectional study (July 2021–October 2022), we systematically documented the demographic, clinical and echocardiographic features of patients with aortic valve disease at Chris Hani Baragwanath Academic Hospital, Johannesburg, South Africa.
Results
This study included 130 consecutive patients with organic aortic valve disease with a median age 55 years, (57.7%) were females. Majority were of African descent (95.4%). Aortic valve regurgitation was the dominant pathology (57.5%) followed by mixed aortic valve disease (31.1%). Aortic valve stenosis was present in 9.4% of patients. Concomitant mitral regurgitation was noted in 33% of patients. The main aetiologies were rheumatic heart disease (67%), degenerative aortic valve disease (27%), infective endocarditis (4%), and bicuspid valve disease (2%). Hypertension (65.9%), dyslipidaemia (30.7%), overweight/obese (59.2%) and HIV (20.8%) were the main comorbidities. Heart failure was present in 54.6% with a mean left ventricular ejection fraction of 50.7%±15.8%. Rheumatic fever prophylaxis was noted in a minority (6.2%). The main complications were atrial fibrillation (8.3%), pulmonary hypertension (35.8%) and renal dysfunction (25.3%). Thirty-five (26.9%) of patients were awaiting surgery.
Conclusion
The majority of patients with aortic valve disease were African females with predominant rheumatic aortic valve regurgitation and multiple comorbidities.
Keywords: Aortic valve disease, aortic regurgitation, rheumatic heart disease