UVM Theses and Dissertations
Format:
Print
Author:
Herath, Sonali A. C.
Dept./Program:
Pathology
Year:
2014
Degree:
MS
Abstract:
Malignant mesothelioma (MM) is a rare and aggressive cancer that arises from the mesothelial lining of the peritoneal and pleural cavities in response to asbestos exposure. Once inhaled, asbestos fibers cause damage to the mesothelial lining, leading to inflammation and activation of chemokines and growth factors that may stimulate the pathogenesis of MM. The precise mechanisms by which asbestos fibers trigger the formation of MMs is still unknown. However, in our laboratory we have been able to elucidate the roles ofthe extracellular signal-regulated kinases (ERKs), particularly ERK1, ERK2, and ERK5, in promoting cell injury, cell repair, as well as abnormal differentiation that ultimately contributes to the malignant characteristics of MM.
The individual roles of the critical ERK family members in promoting cell injury and repair as well as differentiation and carcinogenesis are not well established. The focus of my project was specifically on ERK1, ERK2 and ERK5 kinases that have been associated with asbestos-induced injury and inflammation in prior work in our laboratory; consequently leading to the development of MM. We were interested specifically in the role of these ERKs in gene expression of members of the Matrix Metalloproteinase Pathway (MMP) which consists primarily of a family of proteases that promote the degradation of the extracellular matrix (ECM) and the invasive and metastatic potential of tumor cells. However, the role of the MMP pathway in the pathogenesis of MM has yet to be elucidated.
The objective of this project was to elucidate how ERK1, ERK2 and ERK5 differentially regulated gene expression in different MMs with a focus on the MMP pathway players, MMP-1 and TFPI-2, in human MM cells. We first determined, using 4 MM lines and Western blot analysis that constitutive ERK protein expression varied between lines. We then created stable shERK1, shERK2, and shERK5 knockdown lines as well as shCon (control transfected) lines from the two MM lines, HMESO and H2373, expressing the most ERK proteins. Using genome-wide microarray analysis and Ingenuity Pathway analysis we identified key biological pathways and gene expression in the MMP pathway that may trigger the development and progression of MM.
Additionally, we revealed heterogeneity in differential expression of MMP genes and confirmed the knockdown of ERK1, ERK2 and ERK5 gene and protein expression in the context in HMESO and H2373 MMs. In H2373 MMs, the highest constitutively expressed gene was Tissue Factor Pathway Inhibitor 2 (TPI-2) that was modified in expression by ERK1 and ERK2. Finally in the HMESO MMs, we found that ERKs 1, 2 and 5 co-governed increased expression of the most highly expressed gene, MMP-1, that is critical to migration and invasion, an observation the use of global ERK inhibitors in treatment of MMs Moreover, our findings will allow for a deeper understanding of how MM develops and is regulated by ERKs and MMPs. These findings will open avenues for novel targeted gene therapies that may be more effective than converitional therapeutics in preventing or managing this aggressive form of cancer.
The individual roles of the critical ERK family members in promoting cell injury and repair as well as differentiation and carcinogenesis are not well established. The focus of my project was specifically on ERK1, ERK2 and ERK5 kinases that have been associated with asbestos-induced injury and inflammation in prior work in our laboratory; consequently leading to the development of MM. We were interested specifically in the role of these ERKs in gene expression of members of the Matrix Metalloproteinase Pathway (MMP) which consists primarily of a family of proteases that promote the degradation of the extracellular matrix (ECM) and the invasive and metastatic potential of tumor cells. However, the role of the MMP pathway in the pathogenesis of MM has yet to be elucidated.
The objective of this project was to elucidate how ERK1, ERK2 and ERK5 differentially regulated gene expression in different MMs with a focus on the MMP pathway players, MMP-1 and TFPI-2, in human MM cells. We first determined, using 4 MM lines and Western blot analysis that constitutive ERK protein expression varied between lines. We then created stable shERK1, shERK2, and shERK5 knockdown lines as well as shCon (control transfected) lines from the two MM lines, HMESO and H2373, expressing the most ERK proteins. Using genome-wide microarray analysis and Ingenuity Pathway analysis we identified key biological pathways and gene expression in the MMP pathway that may trigger the development and progression of MM.
Additionally, we revealed heterogeneity in differential expression of MMP genes and confirmed the knockdown of ERK1, ERK2 and ERK5 gene and protein expression in the context in HMESO and H2373 MMs. In H2373 MMs, the highest constitutively expressed gene was Tissue Factor Pathway Inhibitor 2 (TPI-2) that was modified in expression by ERK1 and ERK2. Finally in the HMESO MMs, we found that ERKs 1, 2 and 5 co-governed increased expression of the most highly expressed gene, MMP-1, that is critical to migration and invasion, an observation the use of global ERK inhibitors in treatment of MMs Moreover, our findings will allow for a deeper understanding of how MM develops and is regulated by ERKs and MMPs. These findings will open avenues for novel targeted gene therapies that may be more effective than converitional therapeutics in preventing or managing this aggressive form of cancer.