Home Welcome to Our LabDr. Wang’s lab is part of the Department of Pediatrics at Penn State College of Medicine in Hershey, Pennsylvania. The laboratory is funded by the National Institutes of Health, Hyundai Hope on Wheels, Four Diamonds, and Lois High Berstler and provides an excellent training environment for students and fellows who are interested in basic and translational cancer research. About Us Our ResearchResearch in this laboratory aims to better understand the fundamental mechanisms that control apoptosis (a cell self-killing mechanism) and autophagy (a cell self-eating process). The ultimate goal of Dr. Wang’s research is to translate basic science discoveries to the development of new approaches for the treatment and prevention of cancer. Learn More About Us Go to page Our Research Go to page Lab Members Go to page Contact Us Go to page Research Highlights TOM40 Targets Atg2 to Mitochondria-Associated ER Membranes for Phagophore Expansion.Tang Z, et al. Cell Rep. 2019 Aug 13; 28(7):1744-1757. During autophagy, phagophores grow into double-membrane vesicles called autophagosomes, but the underlying mechanism remains unclear. Here, we show a critical role of Atg2A in phagophore expansion. Atg2A translocates to the phagophore at the mitochondria-associated ER membrane (MAM) through a C-terminal 45-amino acid domain that we have termed the MAM localization domain (MLD). Proteomic analysis identifies the outer mitochondrial membrane protein TOM40 as a MLD-interacting partner. The Atg2A-TOM40 interaction is responsible for MAM localization of Atg2A and requires the TOM receptor protein TOM70. In addition, Atg2A interacts with Atg9A by a region within its N terminus. Inhibition of either Atg2A-TOM40 or Atg2A-Atg9A interactions impairs phagophore expansion and accumulates Atg9A-vesicles in the vicinity of autophagic structures. Collectively, we propose a model that the TOM70-TOM40 complex recruits Atg2A to the MAM for vesicular and/or non-vesicular lipid transport into the expanding phagophore to grow the size of autophagosomes for efficient autophagic flux. An autophagy assay reveals the ESCRT-III component CHMP2A as a regulator of phagophore closure.Takahashi Y, et al. Nat Commun. 2018 Jul 20;9(1):2855. The mechanism of phagophore closure remains unclear due to technical limitations in distinguishing unclosed and closed autophagosomal membranes. Here, we report the HaloTag-LC3 autophagosome completion assay that specifically detects phagophores, nascent autophagosomes, and mature autophagic structures. Using this assay, we identify the endosomal sorting complexes required for transport (ESCRT)-III component CHMP2A as a critical regulator of phagophore closure. During autophagy, CHMP2A translocates to the phagophore and regulates the separation of the inner and outer autophagosomal membranes to form double-membrane autophagosomes. Consistently, inhibition of the AAA-ATPase VPS4 activity impairs autophagosome completion. The ESCRT-mediated membrane abscission appears to be a critical step in forming functional autolysosomes by preventing mislocalization of lysosome-associated membrane glycoprotein 1 to the inner autophagosomal membrane. Collectively, our work reveals a function for the ESCRT machinery in the final step of autophagosome formation and provides a useful tool for quantitative analysis of autophagosome biogenesis and maturation. Targeted Inhibition of ULK1 Promotes Apoptosis and Suppresses Tumor Growth and Metastasis in Neuroblastoma.Dower CM, et al. Mol Cancer Ther. 2018 Nov; 17(11):2365-2376. Neuroblastoma is the most common extracranial solid malignancy in the pediatric population, accounting for over 9% of all cancer-related deaths in children. Autophagy is a cell self-protective mechanism that promotes tumor cell growth and survival, making it an attractive target for treating cancer. However, the role of autophagy in neuroblastoma tumor growth and metastasis is largely undefined. Here we demonstrate that targeted inhibition of an essential autophagy kinase, unc-51 like autophagy kinase 1 (ULK1), with a recently developed small-molecule inhibitor of ULK1, SBI-0206965, significantly reduces cell growth and promotes apoptosis in SK-N-AS, SH-SY5Y, and SK-N-DZ neuroblastoma cell lines. Furthermore, inhibition of ULK1 by a dominant-negative mutant of ULK1 (dnULK1K46N) significantly reduces growth and metastatic disease and prolongs survival of mice bearing SK-N-AS xenograft tumors. We also show that SBI-0206965 sensitizes SK-N-AS cells to TRAIL treatment, but not to mTOR inhibitors (INK128, Torin1) or topoisomerase inhibitors (doxorubicin, topotecan). Collectively, these findings demonstrate that ULK1 is a viable drug target and suggest that inhibitors of ULK1 may provide a novel therapeutic option for the treatment of neuroblastoma. Mechanisms and context underlying the role of autophagy in cancer metastasis.Dower CM, et al. Autophagy. 2018 Jun 4; 14(7):1110-1128. Macroautophagy/autophagy is a fundamental cellular degradation mechanism that maintains cell homeostasis, regulates cell signaling, and promotes cell survival. Its role in promoting tumor cell survival in stress conditions is well characterized, and makes autophagy an attractive target for cancer therapy. Emerging research indicates that autophagy also influences cancer metastasis, which is the primary cause of cancer-associated mortality. However, data demonstrate that the regulatory role of autophagy in metastasis is multifaceted, and includes both metastasis-suppressing and -promoting functions. The metastasis-suppressing functions of autophagy, in particular, have important implications for autophagy-based treatments, as inhibition of autophagy may increase the risk of metastasis. In this review, we discuss the mechanisms and context underlying the role of autophagy in metastasis, which include autophagy-mediated regulation of focal adhesion dynamics, integrin signaling and trafficking, Rho GTPase-mediated cytoskeleton remodeling, anoikis resistance, extracellular matrix remodeling, epithelial-to-mesenchymal transition signaling, and tumor-stromal cell interactions. Through this, we aim to clarify the context-dependent nature of autophagy-mediated metastasis and provide direction for further research investigating the role of autophagy in cancer metastasis. Atg2A/B deficiency switches cytoprotective autophagy to non-canonical caspase-8 activation and apoptosis.Tang Z, et al. Cell Death Differ. 2017 Dec;24(12):2127-2138. Autophagosomal membranes are emerging as platforms for various cell survival and death signaling networks beyond autophagy. While autophagy-dependent cell death has been reported in response to a variety of stimuli, the underlying molecular mechanisms remain far from clear. Here, we demonstrate that inhibition of autophagosome completion by Atg2A/B deletion accumulates immature autophagosomal membranes that promote non-canonical caspase-8 activation in response to nutrient starvation via an intracellular death-inducing signaling complex (iDISC). Importantly, iDISC-induced caspase-8 dimerization and activation occurs on accumulated autophagosomal membranes and requires the LC3 conjugation machinery but is independent from the extrinsic pathway of apoptosis. Moreover, we have identified NF-κB signaling and c-FLIP as negative regulators of iDISC-mediated caspase-8 activation and apoptosis. Collectively, these findings reveal autophagosomal membrane completion as a novel target to switch cytoprotective autophagy to apoptosis. Selective Reversible Inhibition of Autophagy in Hypoxic Breast Cancer Cells Promotes Pulmonary Metastasis.Dower CM, et al. Cancer Res. 2017 Feb 1;77(3):646-657. Autophagy influences how cancer cells respond to nutrient deprivation and hypoxic stress, two hallmarks of the tumor microenvironment (TME). In this study, we explored the impact of autophagy on the pathophysiology of breast cancer cells using a novel hypoxia-dependent, reversible dominant-negative strategy to regulate autophagy at the cellular level within the TME. Suppression of autophagy via hypoxia-induced expression of the kinase-dead unc-51-like autophagy-activating kinase (ULK1) mutant K46N increased lung metastases in MDA-MB-231 xenograft mouse models. Consistent with this effect, expressing a dominant-negative mutant of ULK1 or ATG4b or a ULK1-targeting shRNA facilitated cell migration in vitro Functional proteomic and transcriptome analysis revealed that loss of hypoxia-regulated autophagy promotes metastasis via induction of the fibronectin integrin signaling axis. Indeed, loss of ULK1 function increased fibronectin deposition in the hypoxic TME. Together, our results indicated that hypoxia-regulated autophagy suppresses metastasis in breast cancer by preventing tumor fibrosis. These results also suggest cautions in the development of autophagy-based strategies for cancer treatment. Website created and maintained by Dr. Megan Young (email@example.com).