Chen, Luping
(2024)
Activation of Glucocorticoid Receptor Signaling Inhibits KSHV-Induced Inflammation and Tumorigenesis.
Doctoral Dissertation, University of Pittsburgh.
(Unpublished)
Abstract
Hyperinflammation is the hallmark of Kaposi’s sarcoma (KS), the most common cancer in AIDS patients caused by Kaposi’s sarcoma-associated herpesvirus (KSHV) infection. However, the role and mechanism of induction of inflammation in KS remain unclear. In a screening for inhibitors of KSHV-induced oncogenesis, over half of the identified candidates were anti-inflammatory agents including dexamethasone, which functions by activating glucocorticoid receptor (GR) signaling. Here, we examined the mechanism mediating KSHV-induced inflammation. We found that numerous inflammatory pathways were activated in KSHV-transformed cells. Particularly, interleukin-1 alpha (IL-1α) and IL-1 receptor antagonist (IL-1Ra) from the IL-1 family were the most induced and suppressed cytokines, respectively. We found that KSHV miRNAs mediated IL-1α induction while both miRNAs and vFLIP mediated IL-1Ra suppression. Furthermore, GR signaling was inhibited in KSHV-transformed cells, which was mediated by vFLIP and vCyclin. Dexamethasone treatment activated GR signaling and inhibited cell proliferation and colony formation in soft agar of KSHV-transformed cells but had a minimal effect on matched primary cells. Consequently, dexamethasone suppressed the initiation and growth of KSHV-induced tumors in mice. Mechanistically, dexamethasone suppressed IL-1α but induced IL-1Ra expression. Treatment with recombinant IL-1α protein rescued the inhibitory effect of dexamethasone while overexpression of IL-1Ra caused a weak growth inhibition of KSHV-transformed cells. Furthermore, dexamethasone treatment induced IκBα expression resulting in inhibition of the NF-κB pathway and subsequent IL-1α expression. These results reveal an important role of the IL-1 pathway in KSHV-induced inflammation and oncogenesis, which can be inhibited by dexamethasone-activated GR signaling, and identify IL-1-mediated inflammation as a potential therapeutic target for KSHV-induced malignancies.
Share
| Citation/Export: |
|
| Social Networking: |
|
Details
| Item Type: |
University of Pittsburgh ETD
|
| Status: |
Unpublished |
| Creators/Authors: |
|
| ETD Committee: |
|
| Date: |
16 September 2024 |
| Date Type: |
Publication |
| Defense Date: |
12 January 2024 |
| Approval Date: |
16 September 2024 |
| Submission Date: |
2 April 2024 |
| Access Restriction: |
No restriction; Release the ETD for access worldwide immediately. |
| Number of Pages: |
134 |
| Institution: |
University of Pittsburgh |
| Schools and Programs: |
School of Medicine > Integrative Systems Biology |
| Degree: |
PhD - Doctor of Philosophy |
| Thesis Type: |
Doctoral Dissertation |
| Refereed: |
Yes |
| Uncontrolled Keywords: |
Kaposi’s sarcoma (KS), Kaposi’s sarcoma-associated herpesvirus (KSHV), inflammation, dexamethasone, glucocorticoid receptor (GR) signaling, interleukin-1 alpha (IL-1α), IL-1 receptor antagonist (IL-1Ra), NF-κB |
| Date Deposited: |
16 Sep 2024 19:08 |
| Last Modified: |
16 Sep 2024 19:08 |
| URI: |
http://d-scholarship.pitt.edu/id/eprint/45965 |
Metrics
Monthly Views for the past 3 years
Plum Analytics
Actions (login required)
 |
View Item |
![[feed]](/images/feed-icon-32x32.png){kind=icon}