Conexina 46 es un regulador transcripcional en células HeLa
Date
2022
Type:
Thesis
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68 p.
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Authors
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Publisher
Universidad del Desarrollo. Facultad de Medicina
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Abstract
Cancer is the second leading cause of death in the world and was responsible for around 10 million deaths in 2020. Metastatic colonies are of greatest interest to clinical oncologists as they are responsible for approximately 90% of cancer-associated deaths. Therefore, understanding the molecular mechanisms underlying tumor progression, local invasion, and metastasis formation represents one of the great challenges in cancer research.
Connexins are membrane proteins that form ion channels that participate in cell communication, which is essential for tissues to maintain the ability to grow in a controlled manner and respond to their environment. However, this process is frequently impaired in cancer cells. This is why during the last 50 years, the role of connexins and cell communication has been highlighted in the area of cancer and much of the research effort has been directed to understanding their dysfunction in malignant neoplasms in humans.
Within the Connexin family, Cx46 has been proposed as a biomarker of malignancy in breast cancer, it has also been directly correlated with the presence of cancer stem cells in glioblastoma. In addition, it has been positively correlated with invasion, self-renewal capacity and metastasis independently of GJC formation. Each of these processes of transformation towards a malignant phenotype requires the reprogramming of gene transcription.
Based on the data collected in the literature, the following hypothesis is proposed, cx46 produces phenotypic changes in HeLa cells through gene regulation networks. For this, a stable cell line of HeLa cells over-expressing human Cx46 was generated. The following objectives were studied in it, 1: To evaluate phenotypic characteristics associated with the expression of Cx46 in HeLa cells by means of proliferation, self-renewal and invasion assays. 2: Determination of the subcellular localization of Cx46 by purification of nuclear proteins and confocal microscopy. 3: Determine the nuclear role of the Cx46 protein through ChIP-seq and RNA-seq studies.
The results obtained show that HeLa cells transfected with human Cx46 undergo phenotypic changes such as an increase in their capacity for self-renewal proliferation, migration and invasion. In addition the nuclear presence of the protein, which is found interacting with DNA, could be evidenced. In this context, 77 differentially expressed genes could be found, of which 26 have a Cx46 peak in their promoter region. The expression network analysis determined that those genes that did not have Cx46 in their promoter region were being activated by transcription factors with which Cx46 was interacting.
The data obtained in this thesis allow us to propose a new role for Cx46 as a regulator of gene transcription in the HeLa cell line. Based on the number of tumors that overexpress Cx46 with respect to their surrounding healthy tissue it is plausible to propose Cx46 as a tumor biomarker and therefore as a possible therapeutic target, in accordance with the literature.
Description
Tesis presentada a la Facultad de Medicina de la Universidad del Desarrollo para optar al grado de Doctor en Ciencias e Innovación en Medicina
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Citation
Keywords
Conexinas, Cáncer, Inmunoprecipitación de la cromatina, Regulación génica, 090036S