Koral, Kelly A
(2016)
LEUKOCYTE SPECIFIC PROTEIN-1: A NOVEL REGULATOR OF HEPATOCELLULAR MIGRATION AND PROLIFERATION IN LIVER REGENERATION AND CANCER.
Doctoral Dissertation, University of Pittsburgh.
(Unpublished)
Abstract
Hepatocellular carcinoma (HCC) is the most commonly diagnosed form of liver cancer with high morbidity and mortality. Copy number variation analysis (CNV) of human HCC revealed that over 50% of the HCC samples examined had CNV in the gene leukocyte specific protein-1 (LSP1). LSP1, a F-actin binding protein, is expressed in hematopoietic cells and interacts with Kinase Suppressor of Ras (KSR), a scaffold for the ERK/MAPK pathway. The expression of LSP1 in liver and its role in normal hepatocellular function and carcinogenesis remains unknown. Therefore, LSP1 mRNA and protein levels were analyzed in normal hepatocytes in culture, rat liver following partial hepatectomy (PHx), and hepatoma cell lines. In culture and after PHx, LSP1 increased after the termination of hepatocyte proliferation and migration. To investigate LSP1 function in HCC, shRNA was utilized to stably knock down LSP1 expression in the JM1 rat hepatoma cell line. Loss of LSP1 in JM1 cells resulted in dramatic upregulation of cyclin D1 and pERK2, as well as increased cell proliferation and migration. Co-immunoprecipitation and immunofluorescence analysis displayed an interaction and co-localization between LSP1, KSR and F-actin in the JM1 cells and liver during regeneration. Conversely, expression of LSP1 in JM2 rat hepatoma cell line led to decreased proliferation. Enhanced expression of LSP1 in mouse hepatocytes during liver regeneration following injection of an LSP1 expression plasmid also led to decreased hepatocyte proliferation, cyclin D1 and pERK expression. LSP1 knockout mice subjected to PHx displayed increased hepatocellular proliferation on day 4 when compared to control livers as well as increased pERK expression, whereas LSP1 overexpressing transgenic mice (TG) livers displayed a decrease in Ki67 positive hepatocytes on day 4 following PHx and decreased pERK expression. Hepatocytes from KO mice displayed increased proliferation in the absence of growth factors in culture whereas TG hepatocytes proliferated significantly less than WT control hepatocytes. Conclusion: LSP1 is expressed in normal hepatocytes and liver following PHx after the termination of proliferation. In rat hepatoma cell lines and mouse liver in vivo, LSP1 functions as a negative regulator of proliferation and migration. Given the high frequency of LSP1 CNV in human HCC, LSP1 may be a novel target for diagnosis and treatment of HCC.
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Details
| Item Type: |
University of Pittsburgh ETD
|
| Status: |
Unpublished |
| Creators/Authors: |
|
| ETD Committee: |
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| Date: |
7 September 2016 |
| Date Type: |
Publication |
| Defense Date: |
19 May 2016 |
| Approval Date: |
7 September 2016 |
| Submission Date: |
26 July 2016 |
| Access Restriction: |
No restriction; Release the ETD for access worldwide immediately. |
| Number of Pages: |
129 |
| Institution: |
University of Pittsburgh |
| Schools and Programs: |
School of Medicine > Cellular and Molecular Pathology |
| Degree: |
PhD - Doctor of Philosophy |
| Thesis Type: |
Doctoral Dissertation |
| Refereed: |
Yes |
| Uncontrolled Keywords: |
Hepatocellular Carcinoma, partial hepatectomy, LSP1 |
| Date Deposited: |
07 Sep 2016 15:06 |
| Last Modified: |
22 Apr 2024 19:04 |
| URI: |
http://d-scholarship.pitt.edu/id/eprint/29318 |
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