KSHV-Mediated Regulation of Par3 and SNAIL Contributes to B-Cell Proliferation

PLoS Pathogens

Erle S. Robertson¹  Santosh K. Upadhyay¹  Rajnish K. Singh¹  Sushil K. Sahu¹  Hem C. Jha¹  Darine W. El-Naccache¹  Zhiguo Sun¹ 

[1] Department of Otorhinolaryngology-Head and Neck Cancer, and Tumor Virology Program and Tumor Virology Program, Abramson Cancer Center, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, United States of America

关键词: B cells;    Kaposi's sarcoma-associated herpesvirus;    Carcinogenesis;    Immunoprecipitation;    Cell staining;    Apoptosis;    Infectious disease control;    Nuclear staining;   

DOI  :  10.1371/journal.ppat.1005801

学科分类：生物科学（综合）

来源: Public Library of Science

【 摘 要 】

Studies have suggested that Epithelial–Mesenchymal Transition (EMT) and transformation is an important step in progression to cancer. Par3 (partitioning-defective protein) is a crucial factor in regulating epithelial cell polarity. However, the mechanism by which the latency associated nuclear antigen (LANA) encoded by Kaposi's Sarcoma associated herpesvirus (KSHV) regulates Par3 and EMTs markers (Epithelial-Mesenchymal Transition) during viral-mediated B-cell oncogenesis has not been fully explored. Moreover, several studies have demonstrated a crucial role for EMT markers during B-cell malignancies. In this study, we demonstrate that Par3 is significantly up-regulated in KSHV-infected primary B-cells. Further, Par3 interacted with LANA in KSHV positive and LANA expressing cells which led to translocation of Par3 from the cell periphery to a predominantly nuclear signal. Par3 knockdown led to reduced cell proliferation and increased apoptotic induction. Levels of SNAIL was elevated, and E-cadherin was reduced in the presence of LANA or Par3. Interestingly, KSHV infection in primary B-cells led to enhancement of SNAIL and down-regulation of E-cadherin in a temporal manner. Importantly, knockdown of SNAIL, a major EMT regulator, in KSHV cells resulted in reduced expression of LANA, Par3, and enhanced E-cadherin. Also, SNAIL bound to the promoter region of p21 and can regulate its activity. Further a SNAIL inhibitor diminished NF-kB signaling through upregulation of Caspase3 in KSHV positive cells in vitro. This was also supported by upregulation of SNAIL and Par3 in BC-3 transplanted NOD-SCID mice which has potential as a therapeutic target for KSHV-associated B-cell lymphomas.

【 授权许可】

CC BY