Genetic models of apoptosis-induced proliferation decipher activation of JNK and identify a requirement of EGFR signaling for tissue regenerative responses in Drosophila.
Recent work in several model organisms has revealed that apoptotic cells are able to stimulate neighboring surviving cells to undergo additional proliferation, a phenomenon termed apoptosis-induced proliferation. This process depends critically on apoptotic caspases such as Dronc, the Caspase-9 ortholog in Drosophila, and may have important implications for tumorigenesis. While it is known that Dronc can induce the activity of Jun N-terminal kinase (JNK) for apoptosis-induced proliferation, the mechanistic details of this activation are largely unknown. It is also controversial if JNK activity occurs in dying or in surviving cells. Signaling molecules of the Wnt and BMP families have been implicated in apoptosis-induced proliferation, but it is unclear if they are the only ones. To address these questions, we have developed an efficient assay for screening and identification of genes that regulate or mediate apoptosis-induced proliferation. We have identified a subset of genes acting upstream of JNK activity including Rho1. We also demonstrate that JNK activation occurs both in apoptotic cells as well as in neighboring surviving cells. In a genetic screen, we identified signaling by the EGFR pathway as important for apoptosis-induced proliferation acting downstream of JNK signaling. These data underscore the importance of genetic screening and promise an improved understanding of the mechanisms of apoptosis-induced proliferation.
University of Massachusetts Medical School, Department of Cancer Biology, Worcester, Massachusetts, United States of America.
Yun
Y
Fan
Graduate Program in Developmental Biology, Baylor College of Medicine, Houston, Texas, United States of America.
Shiuan
S
Wang
MD Anderson Cancer Center, Department of Biochemistry & Molecular Biology, Houston, Texas, United States of America.
Jacob
J
Hernandez
MD Anderson Cancer Center, Department of Biochemistry & Molecular Biology, Houston, Texas, United States of America.
Vildan Betul
VB
Yenigun
Länderinstitut für Bienenkunde, Humboldt Universität zu Berlin, Hohen Neuendorf, Germany.
Gillian
G
Hertlein
University of Massachusetts Medical School, Department of Cancer Biology, Worcester, Massachusetts, United States of America.
Caitlin E
CE
Fogarty
University of Massachusetts Medical School, Department of Cancer Biology, Worcester, Massachusetts, United States of America.
Jillian L
JL
Lindblad
University of Massachusetts Medical School, Department of Cancer Biology, Worcester, Massachusetts, United States of America ; Graduate Program in Developmental Biology, Baylor College of Medicine, Houston, Texas, United States of America ; MD Anderson Cancer Center, Department of Biochemistry & Molecular Biology, Houston, Texas, United States of America.
Andreas
A
Bergmann
D000818:Animals; D017209:Apoptosis / Q000235:genetics*; D063646:Carcinogenesis / Q000235:genetics*; D020169:Caspases; D049109:Cell Proliferation; D029721:Drosophila Proteins / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism; D004331:Drosophila melanogaster; D066246:ErbB Receptors / Q000235:genetics* / Q000378:metabolism; D006801:Humans; D048670:MAP Kinase Kinase 4 / Q000235:genetics*; D008957:Models, Genetic; D009369:Neoplasms / Q000235:genetics / Q000473:pathology; D018010:Receptors, Invertebrate Peptide / Q000235:genetics* / Q000378:metabolism; D012038:Regeneration / Q000235:genetics; D060449:Wnt Signaling Pathway; D020741:rho GTP-Binding Proteins / Q000235:genetics* / Q000302:isolation & purification
D029721:Drosophila Proteins; D018010:Receptors, Invertebrate Peptide; C066532:Egfr protein, Drosophila; D066246:ErbB Receptors; D048670:MAP Kinase Kinase 4; D020169:Caspases; C118731:dronc protein, Drosophila; C511153:Rho1 protein, Drosophila; D020741:rho GTP-Binding Proteins