Introduction: The main risk factor for the development of oesophageal adenocarcinoma is Barrett’s oesophagus (BE). To diagnose those patients who will progress to cancer early to improve the dismal survival rate of oesophageal adenocarcinoma, patients with BE undergo regular endoscopic surveillance. The vast majority of patients, however, will never progress and are therefore monitored unnecessarily. Copy number changes have been shown to be important in the progression of BE to oesophageal adenocarcinoma (Li et al., 2014). Shallow whole genome sequencing (sWGS) has been established as a cost-effective method of investigating copy number changes in formalin fixed paraffin embedded (FFPE) tissue (Scheinin et al., 2014). We hypothesised that copy number alterations may be valuable markers in disease progression and aimed to characterise them in the progression of Barrett’s using sWGS in order to predict progression in patients from a point in time as close to baseline endoscopy as possible and to integrate p53 staining. Methods: To optimise sWGS we compared 50X WGS on frozen tissue with 0.1X WGS from FFPE tumour material from the same patient. To address poor cellularity in endoscopic biopsies, shallow WGS data from a 50% cellularity biopsy with a 90% frozen sample from a single patient were compared. Accounting for poor biopsy cellularity 0.4X coverage was used. We performed FFPE shallow WGS on 806 samples from an 89-patient cohort comprising a 1:1 ratio of patients who progressed to high grade dysplasia (HGD) and patients who never progressed. 1-31 samples per patient were collected over time and space throughout surveillance. Non-progressors had significantly longer follow-up (p-value = 0.0008). Data was processed based on published bioinformatic pipelines. Copy number analysis was carried out using a generalised linear model (GLM) in order to develop a predictive algorithm. Results: During optimisation, ˃85% of copy number changes were detected in both frozen and FFPE samples from spatially distinct regions of an individual tumour. We found 91% and 93% agreement in copy number calls using orthogonal platforms between 90% (frozen) and 50% (FFPE) cellularity samples from one tumour. In the 806 sample Barrett’s cohort, we observed larger copy number alterations in patients who progressed to cancer compared with non-progressors and significantly more CN alterations in progressor patients (p-value ˂ 0.001). More cancer-associated genes were affected in progressors and we observed significant heterogeneity between patients. There was also a greater level of complexity seen in the progressor patients when analysed using affinity propagation clustering. These data allowed us to develop a regression model to predict progression. Using the GLM model, we successfully classified samples as early as progressor or not with an AUC of 85.75% and a sensitivity and specificity of 84 and 79% respectively. At the patient level 94% progressor patients had at least one sample classified as at risk of progression and non-dysplastic progressor samples were classified as early as 13 years prior to HGD diagnosis. Depending on the classification threshold used, all samples over time and space were not classified as being at risk of progression in at least 60% patients who have not yet progressed to HGD/cancer. We observed 2 pathways to progression supporting previous observations. 90% of progressors had samples prior to their HGD or cancer diagnosis classified as being predisposed to progression suggestive of genetically unstable lesions from early on in surveillance that progressed to HGD over time. The remaining 10% appeared as non-progressors until their diagnosis of HGD. We investigated p53 expression in our patient cohort as the only biomarker to have successfully transitioned into the clinic for Barrett’s surveillance. Whilst we found our cohort to be representative in staining compared to other published cohorts, it did not contribute to the GLM and the copy number data out-performed the use of p53 IHC in the context of Barrett’s surveillance. Conclusions: We have optimised the use of shallow WGS in oesophageal adenocarcinoma and Barrett’s. Using these copy number data, we can confidently distinguish between patients who will progress to cancer and the majority of patients who will never progress. This approach has led to the development of a model for predicting progression in the clinical setting which is promising for further clinical validation.

Abstract Integrin-linked Kinase (ILK) is an integrin-associated protein kinase, which regulates growth factor-signalling pathways and cell-ECM adhesion events. Abrogated ILK expression or activity has been implicated in contributing to oncogenic transformation. We examined the role played by ILK in growth factor-stimulated and integrin signalling events in five human oesophageal squamous cell carcinoma cell lines (HOSCCs), known to overexpress the EGF receptor. Western blot analysis revealed the presence of ILK (59kDa) in all the moderately differentiated HOSCC lines. ILK1 was confirmed as being the predominant isoform. Densitometrically analysed Western blots showed that, per unit of protein, ILK is expressed uniformly across the cell lines under standard culture conditions. Following EGF (10 ng/ml) and TGFβ1 (1 ng/ml) treatment, ILK expression increased in all five HOSCCs. Indirect immunofluorescence microscopy showed the majority of ILK to localise at a cytoplasmic/nuclear level, with a proportion of ILK localising at the membrane, which resembled the distribution pattern of the β3 integrin subunit. This membranal distribution most likely follows that of the adhesion plaques although lesser, and variable, amounts were also identified throughout the cytoplasm. The functionality of the ILK1 kinase domain was demonstrated using myelin basic protein (MBP)-based kinase assays. EGF and TGFβ1 treatment produced an increase in ILK activity in the WHCO3 cell line of 3.5 fold, but a decrease in activity in the other cell lines, which are suggested to involve the actions of PTEN. The identification of nuclear ILK was surprising, and the mechanism for nuclear ILK localisation was suggested to involve a caveolae-associated protein, caveolin-1. Cell adhesion assays revealed that KP-392-mediated inhibition of ILK resulted in a nonsignificant reduction in cell adhesion to collagen and fibronectin. These data provide distinctive evidence for the influence of growth factors on ILK expression, but a duality in the effect on ILK activity. This apparent dichotomy is noteworthy and may be of particular relevance in HOSCC. It is further suggested that KP-392-induced ILK inhibition destabilises the αβ integrin heterodimer and that PI3K acts upstream of ILK-mediated cell adhesion events in HOSCCs. This suggests that ILK mediates integrin associated processes in human oesophageal SCC cell lines.

Faculty of Science; School of molecular and Cell Biology; MSC Dissertation / Background: Cancer of the oesophagus ranks as the ninth most common malignancy in the world, and recent evidence shows that its incidence is increasing. Apoptosis is a process of programmed cell death, which is as essential as cell growth, for the maintenance of homeostasis. When these processes lose integration, such as cancer, then uncontrolled cell growth occurs. There are at least five ACBP subgroups and the two being focused on in this study is B-ACBP (brain specific) and 1-ACBP (found in nearly all tissues). ACBPs act as intracellular carrier-proteins for medium to long chain acyl-coA, mediating fatty acid transport to the mitochondrion for ß-oxidation. ACBPs are also believed to be putative ligands of PBR (Peripheral Benzodiazepine Receptor), and bound to this receptor facilitates mitochondrial membrane permeabilization giving the notion that it favours apoptosis. Aim: To establish the expression patterns of 1-ACBP, B-ACBP, and PBR in oesophageal cancer, and to characterize their roles in this disease. Methodology: Paraffin-embedded sections of normal and malignant oesophageal tissues were utilized for localization studies. RNA probes was synthesized and labelled using Digoxigenin for colorimetric and fluorescent detection during the in situ hybridization (ISH) technique for localization. Real time quantitative RT-PCR was performed to determine the expression levels of the three genes in oesophageal cancer RNA using the Roche Lightcylcer .Results: All three genes showed substantial upregulation within the malignant tissue sections compared to normal oesophageal sections, all three transcripts localized specifically to plasma cells and lymphocytes in diseased and normal tissue section. In the diseased tissue B-ACBP and 1-ACBP mRNA localized to endothelial cells of blood vessels in the submucosa. B-ACBP also localized to the nucleus of squamous epithelium cells. PBR localization occurred in tumour islands in invasive tissue sections. Quantitative RT-PCR also illustrated PBR expression level was the highest compared to the ACBP genes expression in tumours. Conclusion: These results show that 1-ACBP, B-ACBP and PBR play a role in the pathogenesis of oesophageal cancer as well as immunology. Further experiments are still required to determine the function of these genes and the role they play in apoptosis and oesophageal cancer.

No / Neoadjuvant chemoradiotherapy (neo-CRT) prior to surgery is the standard of care for oesophageal adenocarcinoma (OAC) patients. Unfortunately, most patients fail to respond to treatment. MiR-187 was previously shown to be downregulated in neo-CRT non-responders, whist in vitro miR-187 overexpression enhanced radiosensitivity and upregulated PTEN. This study evaluates the role of miR-187 and downstream PI3K signalling in radiation response in OAC. The effect of miR-187 overexpression on downstream PI3K signalling was evaluated in OAC cell lines by qPCR and Western blotting. PTEN expression was analysed in OAC pre-treatment biopsies of neo-CRT responders and non-responders. Pharmacological inhibition of PI3K using GDC-0941 was evaluated in combination with radiotherapy in two-dimensional and three-dimensional OAC models in vitro and as a single agent in vivo. Radiation response in vitro was assessed via clonogenic assay. PTEN expression was significantly decreased in neo-CRT non-responders. MiR-187 overexpression significantly upregulated PTEN expression and inhibited downstream PI3K signalling in vitro. GDC-0941 significantly reduced viability and enhanced radiation response in vitro and led to tumour growth inhibition as a single agent in vivo. Targeting of PI3K signalling is a promising therapeutic strategy for OAC patients who have repressed miR-187 expression and do not respond to conventional neo-CRT. This is the first study evaluating the effect of PI3K inhibition on radiosensitivity in OAC, with a particular focus on patients that do not respond to neo-CRT. We have shown for the first time that targeting of PI3K signalling is a promising alternative therapeutic strategy for OAC patients who do not respond to conventional neo-CRT.

Oesophageal adenocarcinoma (OAC) is a leading cause of cancer death in the UK and current systemic therapies are ineffective for the majority of patients. The central aim of this work was to explore strategies to identify novel therapeutic targets. Research has failed, thus far, to identify a dominant oncogene in OAC, although the tumour suppressor p53 is frequently mutated. Inhibiting the mitotic kinase, polo-like kinase 1 (PLK-1), was proposed as a synthetic lethal strategy. PLK-1 was demonstrated to be over-expressed in both verified OAC cell lines and human OAC tissue compared to non-transformed cells and epithelium. Mutation of p53 was associated with over-expression of PLK-1 in both OAC and ovarian cancer tissue. Using a carefully validated viability assay, both an established and novel PLK-1 inhibitor were demonstrated to induce a G2/M arrest and reduce OAC cell proliferation. Relative selectivity was demonstrated for OAC compared to non-transformed cells. This therapeutic window could be enhanced with the induction of cancer cell cytotoxicity by pulsed administration of a short half-life inhibitor. Immunotherapeutics offer potential tumour-selectivity but no OAC-specific proteins have been defined. A comparative proteomic approach was employed to identify OAC-specific proteins as potential therapeutic targets. A tissue resource was established and methods to lyse fresh frozen biopsies optimised. An isobaric quantitative proteomic workflow was applied to OAC and matched normal biopsies and quantitative accuracy confirmed for 6 candidate proteins by immunohistochemistry. Proteome coverage and quantitative dynamic range were compared between isobaric and label-free systematic sequencing proteomic strategies applied to further patients’ tissues. The challenges of combining incomplete datasets were approached with a Bayesian framework to estimate the probability that a protein was missed during an experiment compared to not being present in the sample. This method was applied to generate a complete set of protein identifications and relative tissue expression. To gain insight into the dysregulated cellular processes in human OAC tissue, a network analysis was applied to the quantitative proteomic data. Enriched functional clusters were identified suggesting deranged glucose metabolism, potentially due to the Warburg effect. These findings were duplicated and candidate tumour-specific proteins identified in a further set of biopsies using the optimised quantitative proteomic method. The combined quantitative oesophageal proteomic dataset represents the largest in OAC to date. This thesis demonstrates a hypothesis-driven, synthetic lethal approach can yield cancer-selective therapeutic effects. Novel candidate therapeutic targets are also revealed through the development of quantitative proteomic methods and the application of network analysis.

The UK has experienced an increase in the incidence of oesophageal adenocarcinoma (OAC) in recent years. The prognosis for patients with OAC remains poor with currently available treatments prompting a search for alternative ‘chemopreventive’ treatments that inhibit oesophageal carcinogenesis. Both non-steroidal anti-inflammatory drugs (NSAIDS) and flavonoids are associated with a significant risk reduction for developing OAC in epidemiological studies. The aim of this study was to validate Levrat’s surgical model of OAC in the rat, and assess the chemopreventive effects of the NSAID aspirin, and the flavonoid quercetin on the development of OAC in the validated rat model. METHODS: Levrat’s model was validated in a time course experiment. Morphological and molecular events occurring in the distal oesophagus during disease progression were determined and compared to human disease. The effect of aspirin and quercetin on disease initiation and progression was determined by commencing treatment either before the onset of reflux, or 4-weeks afterwards. The incidence of Barrett’s oesophagus (BO) and OAC within each group was determined, along with methylation levels of the ESR-1, p16 and HPP1 gene promoter regions. RESULTS: The morphological and molecular changes in the distal oesophagus of the rat model are broadly consistent with those reported in human disease. The incidence of OAC was significantly lower in aspirin treated rats. A non-significant reduction in incidence of OAC was observed with quercetin treatment. Timing of treatment with regard to onset of reflux had no significant effect on OAC development in either treatment group. Neither treatment significantly effected methylation levels within the gene promoters examined. CONCLUSION: Use of Levrat’s model as a model of human OAC seems justified. Aspirin inhibits development of oesophageal adenocarcinoma induced by reflux in this rat model. No additional reduction in cancer incidence is observed if treatment is commenced prior to inception of reflux disease.

Background: 20 to 30% of patients with GORD respond inadequately to conventional therapy. Most of these patients belong to the non-­‐erosive reflux disease group. Despite not having oesophagitis, in these patients oesophageal mucosal integrity appears to be impaired. Aims: To study the dynamic in vitro and in vivo properties of oesophageal mucosal integrity in patients with non-­‐erosive reflux disease, and to test the feasibility of a topical mucosal protectant therapy. Methods: In vitro studies of mucosal integrity were done on human oesophageal biopsies using Ussing chambers. Change in transepithelial electrical resistance (TER) on exposure to acidic solutions was measured. Integrity was assessed in vivo by measuring impedance change and subsequent recovery after oesophageal acid perfusion in symptomatic patients. Proximal and distal oesophageal mucosal integrity was assessed in vitro and in vivo. The effect of in vitro topical application of an alginate-­‐based solution on acid-­‐induced changes in mucosal integrity was tested. Results: In vitro exposure of biopsies to acidic and weakly acidic solutions caused a greater impairment of integrity in symptomatic patients than in controls. In vivo oesophageal acid perfusion causes a profound drop in distal oesophageal impedance that is slow to recover. Recovery is slower in patients with non-­‐erosive reClux disease than in patients with functional heartburn, and a low baseline impedance is associated with painful perception of acid. Proximal oesophageal sensitivity appears unrelated to impaired mucosal integrity, but rather to a distinct sensory afferent nerve distribution. Topical pre-­‐treatment with an alginate solution is able to prevent acid-­‐induced changes in integrity in vitro. Conclusion: Patients with non-­‐erosive reClux disease have a distinct mucosal vulnerability to acidic and weakly acidic solutions that may underlie persistent symptoms. A topical therapeutic approach may be a feasible add-­‐on strategy to treat GORD in the future.

Mutations in RHBDF2, the gene encoding inactive rhomboid protein iRHOM2, result in the dominantly inherited condition Tylosis with oesophageal cancer (TOC). TOC causes plamoplantar keratoderma, oral precursor lesions and up to a 95 % life-time risk of oesophageal squamous cell carcinoma (SCC). The role of iRHOM2 in the epidermis is not well characterised, although we previously showed dysregulated epidermal growth factor receptor (EGFR) signalling and accelerated migration in TOC keratinocytes, and a role for iRHOM2 was shown in trafficking the metalloproteinase ADAM17. Substrates of ADAM17 include EGFR ligands and adhesion molecules. iRHOM2 localisation and function were investigated in frozen sections and keratinocyte cell lines from control and TOC epidermis. Although iRHOM2 was predicted to be an ER-membrane protein, it showed cell-surface expression in control epidermis, with variable localisation in TOC. Increased processing and activation of ADAM17 was seen in TOC keratinocytes compared with control cells, suggesting that increased ADAM17-mediated processing of EGFR ligands may cause the changes in EGFR signalling. Downstream of iRHOM2-ADAM17, Eph/Ephrin and NOTCH signalling also appeared affected. Additionally, desmosomes in TOC epidermis lacked the electron-dense midline of the mature desmosomes seen in normal skin; this was accompanied by increased processing of desmoglein 2, a substrate of ADAM17. Expression and localisation of iRHOM2 was also investigated in TOC and sporadic SCC. iRHOM2 expression varied between SCC cell lines, and appeared to correlate with ADAM17 and NOTCH1 expression in oesophageal SCC and head and neck SCC cells. In summary, iRHOM2 mutations in TOC appear to be gain-of-function in nature, resulting in increased ADAM17 processing and enhanced EGFR signalling. Questions remaining include the reason why iRHOM2 is found at the plasma membrane. Future study of the iRHOM2-ADAM17 pathway may provide additional insight into the mechanism of epidermal wound healing and the pathogenesis of oesophageal SCC.

Introduction: The incidence of gastro-oesophageal cancers has increased considerably over the last decade. As the disease is associated with a poor prognosis, there is a need to identify markers of treatment response which could be used in the future to improve the management of gastro-oesophageal tumours. Aims: 1) To compare the ability of published histological grading criteria (Becker, Mandard and Ninomiya) to assess response to neo-adjuvant chemotherapy (NCT) in gastro-oesophageal cancers. 2) To evaluate the expression of thymidylate synthase (TS) in pre-treatment diagnostic biopsy samples as a predictive marker of response to NCT. 3) To investigate whether measurements of hypoxia obtained using pimonidazole are prognostic for treatment outcome in patients with gastro oesophageal adenocarcinoma (ACC). 4) To study the prognostic significance and clinicopathological associations of epithelial mesenchymal transition (EMT) related proteins S100A4, Vimentin and Snail1 in gastro-oesophageal junction (GOJ) tumours. 5) To evaluate the ability of dynamic contrast enhanced (DCE) MRI to assess chemoradiotherapy (CRT) induced changes in oesophageal cancer. Methods: 1) Formalin fixed paraffin embedded (FFPE) tumour blocks and haematoxylin and eosin stained slides of samples from resected tumours (n=66) were obtained from patients who received NCT for gastric and GOJ tumours. The slides were scored independently by two observers and kappa scores calculated. 2) Pre-treatment diagnostic tissue biopsy samples were obtained from 45 patients with gastric and GOJ cancer who received NCT. TS expression was assessed using immunohistochemistry (IHC) and scored by two observers. The clinical and pathological data were analysed. 3) 57 patients were prospectively administered intravenous pimonidazole and the tumour specimens were collected both at staging laparoscopy and resection. IHC was performed to assess pimonidazole expression and determine its association with clinico-pathological factors. 4) Tissue microarrays were prepared from resection specimens from GOJ ACC. IHC was performed to investigate EMT related protein expression. 5) DCE-MRI was performed on five patients diagnosed with oesophageal cancer treated with CRT. Multiple pharmacokinetic parameters were evaluated. Findings: 1) Becker's histological grading criteria was the most reproducible and prognostic of outcome. The incidence of complete histological response (5%) was low in patients receiving NCT. 2) No prognostic benefit of TS expression was identified. 3) Results from only 34 patients were available for analysis. 77% pimonidazole positivity was observed. Preoperative anaemia was associated with significant tumour pimonidazole expression (p=0.04). Pimonidazole was not prognostic for outcome. 4) The overall positive expression was S100A4 (85%), Vimentin (14%) and Snail1 (89%). The increased expression of S100A4 at the tumour body (p=0.02) and luminal surface (p=0.01) was associated with a poor outcome. 5) Significant changes were measured in DCE-MRI pharmacokinetic parameters after CRT. Conclusion: 1) Becker's histological response grading criteria should be further studied in routine clinical practice for response assessment to NCT. 2) TS should be explored further as a marker of NCT response in gastro-oesophageal cancer. 3) Hypoxia is a characteristic feature of upper gastrointestinal ACC and is associated with anaemia. 4) S100A4 is the most useful marker of EMT in GOJ adenocarcinoma. 5) DCE-MRI tracer kinetic parameters should be explored in a larger study to assess their ability to monitor the efficacy of and predict response to neo-adjuvant treatment.

Thesis (MSc (Genetics))--University of Stellenbosch, 2009. / ENGLISH ABSTRACT: Oesophageal cancer (OC) is characterised by the development of malignant tumours in the epithelial cells lining the oesophagus. It demonstrates marked ethnic variation, with squamous cell carcinoma (SCC) being more prevalent in the Black population and adenocarcinoma (ADC) occurring more often in Caucasians. The aetiology of this complex disease has been attributed to a variety of factors, including an excess of iron (resulting in increased tumourigenesis), oesophageal injury and inflammation. The present study attempted to determine the mutation spectrum of the regulatory and coding regions of the ceruloplasmin (CP) gene, involved in iron metabolism, in the Black South African OC population. The patient cohort was comprised of 96 (48 male and 48 female) unrelated individuals presenting with SCC of the oesophagus. The control group consisted of 88 unrelated, healthy population-matched control individuals. The techniques employed for mutation detection in this study included polymerase chain reaction (PCR) amplification, heteroduplex single-strand conformation polymorphism (HEX-SSCP) analysis, restriction fragment length polymorphism (RFLP) analysis followed by bidirectional semi-automated DNA sequencing analysis to verify the variants identified. Mutation detection of CP resulted in the identification of fourteen previously described (5’UTR-567C→G, 5’UTR-563T→C, 5’UTR-439C→T, 5’UTR-364delT, 5’UTR-354T→C, 5’UTR-350C→T, 5’UTR-282A→G, V223, Y425, R367C, D544E, IVS4-14C→T, IVS7+9T→C and IVS15-12T→C) and four novel (5’UTR-308G→A, T83, V246A and G633) variants. Statistical analysis revealed that two of the novel variants were significantly associated with OC in this study; the promoter variant 5’UTR-308G→A (P=0.012) and the exonic variant G633 (P=0.0003). It is possible that these variants may contribute to OC susceptibility in the Black South African population. OC symptoms generally present late in the development of the disease, and as a result treatment after diagnosis is highly ineffective. Early detection of symptoms and subsequent treatment is therefore the most effective manner of disease intervention. In high incidence areas, such as the Transkei region of South Africa, the implementation of a screening programme would be the ideal way to achieve this goal. The information that can be gathered from the identification of potential modifier genes for OC can lead to improvements in early detection, which in turn may lead to advancements in the treatment and counselling to individuals with OC. To our knowledge, this is the first study concerning CP and its effects on iron dysregulation in the Black South African population with oesophageal cancer. / AFRIKAANSE OPSOMMING: Oesofageale kanker word gekenmerk deur die ontwikkeling van kwaardaardige gewasse in die epiteelweefsel van die oesofageale voering. Hierdie siekte demonstreer opvallende etniese variasie, met plaveisel selkarsinoom meer algemeen in die Swart populasie en adenokarsinoom meer algemeen in die Kaukasiese populasie. Die ontwikkeling van hierdie komplekse siekte word aan ‘n aantal faktore toegeskryf, insluitend ‘n oormaat yster (wat lei tot ‘n vermeerdering van gewasse) en oesofageale besering en -ontsteking. Die doel van die hierdie studie was om die mutasie spektrum van die regulatoriese- en koderingsarea van die ceruloplasmin (CP) geen, betrokke in yster metabolisme, in die Swart Suid Afrikaanse oesofageale kanker populasie te bepaal. Die pasiënt groep het bestaan uit 96 (48 manlik en 48 vroulik) onverwante individue met plaveisel selkarsinoom van die oesofagus. Die kontrole groep het uit 88 nie-geaffekteerde onverwante, populasie spesifieke individue bestaan. Die tegnieke aangewend vir mutasie deteksie in hierdie studie sluit in polimerase kettingsreaksie amplifikasie, heterodupleks enkelstring konformasie polimorfisme analise en restriksie fragment lengte polimorfisme analise, gevolg deur tweerigting semi-geoutomatiseerde DNS volgorde-bepalingsanalise om die geïdentifiseerde variante te bevestig. Mutasie deteksie van CP het tot die identifikasie van veertien reeds beskryfde (5’UTR-567C→G, 5’UTR-563T→C, 5’UTR-439C→T, 5’UTR-364delT, 5’UTR-354T→C, 5’UTR-350C→T, 5’UTR-282A→G, V223, Y425, R367C, D544E, IVS4-14C→T, IVS7+9T→C en IVS15-12T→C) en vier nuwe (5’UTR-308G→A, T83, V246A en G633) variante gelei. Statistiese analise het getoon dat twee van die nuwe variante betekenisvol geassosieerd was met oesofageale kanker in hierdie studie; die promotor variant 5’UTR-308G→A (P=0.012) en die eksoniese variant G633 (P=0.0003). Dit is moontlik dat hierdie variante mag bydra tot oesofageale kanker vatbaarheid in die Swart Suid Afrikaanse populasie. Oesofageale kanker simptome vertoon gewoonlik op ‘n latere stadium in die ontwikkelingsproses van die siekte, en as ‘n gevolg is behandeling na diagnose hoogs oneffektief. Vroegtydige identifikasie van die simptome en daaropvolgende behandeling is die mees effektiewe manier vir ingryping. In hoë voorkoms streke, soos die Transkei gebied van Suid Afrika, sal die implementasie van ‘n siftingsprogram die ideale manier wees om hierdie doel te bereik. Die inligting wat dan versamel word, insluitend identifisering van modifiserende gene vir oesofageale kanker, kan lei tot ‘n verbetering in vroegtydige deteksie van die siekte. In effek kan dit dan lei tot beter behandeling en berading vir individue met oesofageale kanker. So ver ons kennis strek, is hierdie die eerste studie wat CP en sy effek op yster disregulasie in die Swart Suid-Afrikaanse populasie met oesofageale kanker behels.