https://www.um.edu.mt/library/oar/handle/123456789/103891 2026-04-11T14:24:43Z 2026-04-11T14:24:43Z https://www.um.edu.mt/library/oar/handle/123456789/107029 2023-09-22T08:56:34Z 2022-01-01T00:00:00Z

Title: Effect of Wnt inhibition drug treatment on chemoresistant colorectal cancer Abstract: Colorectal cancer (CRC) is one of the most commonly diagnosed cancers worldwide, in addition to being responsible for a significant portion of cancer-related deaths. It arises as a result of mutations to genes such as the Adenomatous Polyposis Coli (APC), which aberrantly activate the canonical and non-canonical Wnt signaling pathways, resulting in promoted cell growth. In addition to this, chemoresistance is an additional factor which affects cellular growth by making the cells unresponsive to treatment, allowing them to continue proliferating. Thus, there is a need to investigate potential treatments which can counteract these adverse effects. In this study, two PORCN inhibitors, LGK974 and ETC-159, at concentrations of 10M and 0.2M, respectively, were used to treat parental and 5-FU resistant CRC cell lines bearing either wild-type APC or an APC truncation mutation. Presto Blue viability assays were conducted over 72 hours to assess cell viability in response to treatment. Scratch migration and transwell invasion assays were performed to study the drugs' effects on migration and invasion. Western blotting was then carried out for - catenin, CDC42, EGFR, and mono- and tri-methyl lysine. Lastly, an ELISA was used to quantify total and phosphorylated EGFR in response to treatment. Results indicate that daily treatment with the Wnt inhibitors can reduce CRC cell viability, irrespective of APC mutation or chemoresistance status. Results from the migration and invasion assays continue to reveal the complexity of the canonical and non-canonical Wnt pathways with decreases and increases in migration and invasion rate observed. While Western blotting did not reveal any significant differences in the protein expression of -catenin, CDC42 and EGFR, results for mono- and tri-methyl lysine were more interesting and suggest that APC truncation and chemoresistance status affect these modifications to some extent. This revealed lysine methylation as a potential diagnostic or prognostic biomarker for CRC treatment using LGK974 and ETC-159, although further studies are warranted to properly reveal the underlying mechanisms which link these characteristics. APC truncation status and chemoresistance were also revealed to potentially be playing some role in the expression of total and phosphorylated EGFR from the results obtained by the ELISA. Description: M.Sc.(Melit.)

2022-01-01T00:00:00Z https://www.um.edu.mt/library/oar/handle/123456789/106984 2023-03-07T06:59:20Z 2022-01-01T00:00:00Z

Title: Defining a small molecules differentiation cocktail for generation of dopaminergic neurons from Wharton’s jelly mesenchymal stem cells Abstract: The incidence of neurodegenerative diseases is on the rise, and yet patients remain without a cure. A suitable disease model could be applied for drug development, disease progression modelling and regenerative therapy. The study’s primary aim was to define a fully-characterised dopaminergic neuronal transdifferentiation protocol for research and therapeutic purposes, with the principal objective being the treatment of Mesenchymal Stem Cells (MSCs) with a 3-stage small molecule strategy. Using RT-qPCR, RNA transcript levels for neural markers were assessed in differentiating cells. Changes in protein lysine and arginine methylation and dopamine-release in differentiating cells were explored using Western blotting, and ELISA respectively. Changes in cell structure towards a neuronal morphology and neurite outgrowth increased considerably with each stage of differentiation. RNA transcript levels suggested that Stage 2 cells had differentiated into immature neuronal cells. Substantial changes in protein methylation levels of cells at different treatment stages were found, and dopamine release increased in Stages 2- and 3-treated cells. ELISA results suggest that the protocol was successful at specifying a dopaminergic fate, though the cells might require further maturation in culture. Mass Spectrometry results revealed hundreds of unique proteins between MSCs and Stage 3 induced neurons, with expression of many neuron-associated proteins in the final neuronal cells. More experiments are required to conclude on the cellular differentiation extent achieved, cell fate, and functionality, and to fully optimise the protocol for dopaminergic differentiation of MSCs. The results produced in this study reveal the potential of this research and warrant the study’s further investigation. Description: M.Sc.(Melit.)

2022-01-01T00:00:00Z https://www.um.edu.mt/library/oar/handle/123456789/106681 2023-02-22T08:36:31Z 2022-01-01T00:00:00Z

Title: The genetics of risk in type 2 diabetes mellitus : does whole exome sequencing of pooled DNA identify population-specific risk alleles? Abstract: Type 2 Diabetes Mellitus T2DM is a common disorder in the population of the Mediterranean region. The aim of this study was to address the issue of genetic risk in T2DM as part of a long-term project following two lines of investigation. Firstly, by mapping selective panels with cognate loci, and secondly by searching for additional genetic risk alleles among the genomes of three comparative neighbouring populations from the central Mediterranean (Maltese, Italian and Libyan). Innovative Pool-seq was used to improve the efficiency of these studies however there were certain limitations. In particular, though demonstrably strong, it could have benefited from using larger population groups with well-defined ancestry and geographic origins, as well as having more robust objective phenotypes. In this study, data is provided indicating the quantitative combination of 11 risk alleles is significantly linked with an increase in the risk of developing T2DM in these populations studied. Since an individual genetic variant, is not very informative for evaluating disease risk, the summation of multiple risk alleles was necessary to detect those at high risk. By examining the SNV data, this study has demonstrated, that the genetic relatedness of European populations such as Maltese, Italian and the North African Libyan population are quite closely linked. It is interesting to note that although the associated variants with known T2DM risk alleles in the three populations are quite similar, the similarities in risk alleles between Maltese and Italians was even stronger than would be expected from their shared ancestry. Description: Ph.D.(Melit.)

2022-01-01T00:00:00Z https://www.um.edu.mt/library/oar/handle/123456789/104853 2023-01-04T08:29:19Z 2022-01-01T00:00:00Z

Title: Investigating effects of carob extracts on leukaemia Abstract: Acute promyelocytic leukaemia (APL) is a leukaemia subtype defined by the presence of high numbers of abnormal haematopoietic cells arrested at the promyelocytic stage within the bone marrow. APL prognosis has increased considerably with the introduction of all-trans retinoic acid (ATRA) in combination with arsenic trioxide (ATO) as therapy, however it still has limitations. Particularly, up to 15% of APL patients are either naturally resistant to it or become resistant after repeated rounds of such treatment and relapse. These patients have poor prognosis as it becomes equal to that of patients before ATRA and ATO introduction. Hence, a better treatment is required. Polyphenols present in honeys and syrups have, through studies, shown anticancer effects on leukaemia cells. Therefore, this study aims to confirm if polyphenolrich extracts from carob honey (CHE) and syrup (CSE) have beneficial effects on ATRA-resistant APL NB4-R2 cells and the nature of their effects. Polyphenols were extracted and confirmed through dispersive liquid-liquid microextraction and compositional assays respectively. Their effects on NB4-R2 cell viability and differentiation were tested through 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide and nitroblue tetrazolium assays and morphological analysis. Their antiproliferative effects were tested through cell cycle analysis, and they were tested on lymphocytes to elucidate cytotoxic effects. At particular concentrations, the CHE and CSE partially differentiated and decreased the viability of NB4-R2 cells and arrested them within different cell cycle phases. They did not negatively affect the viability of lymphocytes. Hence, this study confirmed that specific concentrations of CHE and CSE confer antiproliferative, and a degree of differentiative and viability decreasing effects on these cells but do not confer cytotoxic effects on the healthy cells. Altogether, this study concludes that specific concentrations of CHE and CSE could be a potential treatment against APL and highlights the need for these extracts to be investigated further. Description: B.Sc. (Hons) Med. Biocem.

2022-01-01T00:00:00Z