Anti-Tumor Effect of Turandot Proteins Induced via the JAK/STAT Pathway in the mxc Hematopoietic Tumor Mutant in Drosophila (original) (raw)

Anti-tumour effects of antimicrobial peptides, targets of the innate immune system, against haematopoietic tumours in Drosophila mxc mutants

Disease Models & Mechanisms, 2019

The innate immune response is the first line of defence against microbial infections. In Drosophila, two major immune pathways induce the synthesis of antimicrobial peptides (AMPs) in the fat body. Recently, it has been reported that certain cationic AMPs exhibit selective cytotoxicity against human cancer cells. However, not much is known about their anti-tumour effects. Drosophila mxcmbn1 mutants exhibit malignant hyperplasia in a larval haematopoietic organ called the lymph gland (LG). Here, using RNA-Seq analysis, we found that many immunoresponsive genes, including AMP genes, were up-regulated in the mutants. Down-regulation of these pathways by either a Toll or an imd mutation enhanced the tumour phenotype of the mxc mutants. Conversely, ectopic expression of each of five different AMPs in the fat body significantly suppressed the LG hyperplasia phenotype in the mutants. Thus, we propose that the Drosophila innate immune system can suppress the progression of haematopoietic tu...

Anti-tumor effects of antimicrobial peptides, targets of the innate immune system, against hematopoietic tumors in Drosophila mxc mutants

2018

The innate immune response is the first line of defense against microbial infections. In Drosophila, three immune pathways induce the synthesis of antimicrobial peptides (AMPs) in the fat body. Recently, it has been reported that certain cationic AMPs exhibit selective cytotoxicity against human cancer cells. However, little is known about their anti-tumor effects. Drosophila mxcmbn1 mutants exhibit malignant hyperplasia in a larval hematopoietic organ called the lymph gland (LG). Here, using RNA-Seq analysis, we found that many immunoresponsive genes, including AMP genes, were up-regulated in the mutants. Down-regulation of these pathways by either a Toll or an imd mutation enhanced the tumor phenotype of the mxc mutants. Conversely, ectopic expression of each of five different AMPs in the fat body significantly suppressed the LG hyperplasia phenotype in the mutants. Thus, we propose that the Drosophila innate immune system can suppress progression of hematopoietic tumors by induci...

Opposing roles for Drosophila JAK/STAT signalling during cellular proliferation

Oncogene, 2005

The JAK/STAT signalling pathway mediates both antiproliferative responses following interferon stimulation and cellular proliferation in response to cytokines such as interleukins and growth factors. Central to these responses are the seven vertebrate STAT molecules, misregulation of which is implicated in a variety of malignancies. We have investigated the proliferative role of the single Drosophila STAT92E, part of the evolutionarily conserved JAK/STAT cascade. During second instar larval wing disc development pathway activity is both necessary and sufficient to promote proliferation of this epithelial cell type. However by later stages, endogenous STAT92E is stimulated by a noncannonical mechanism to exert pronounced antiproliferative effects. Ectopic canonical activation is sufficient to further decrease proliferation and leads to the premature arrest of cells in the G2 phase of the cell cycle. The single STAT92E present in Drosophila therefore mediates both proproliferative functions analogous to vertebrate interleukin-stimulated STAT3 and antiproliferative functions analogous to interferon-stimulated STAT1. Pro-and antiproliferative roles therefore represent ancestral activities conserved through evolution and subsequently assigned to distinct molecules.

Drosophila hemocytes recognize lymph gland tumors of mxc mutants and activate the Toll pathway in reactive oxygen species-dependent manner

2021

ABSTRACTMechanisms of cancer cell recognition and elimination by the innate immune system remains unclear. Circulating hemocytes are associated with the hematopoietic tumors in Drosophila mxcmbn1 mutant larvae. The innate immune signalling pathways are activated in the fat body to suppress the tumor growth by inducing antimicrobial peptides (AMP). Here, we investigated the regulatory mechanism underlying the activation in the mutant. Reactive oxygen species accumulated in the hemocytes due to induction of dual oxidase and its activator. The hemocytes were also localized on the fat body. These were essential for transmitting the information on tumors toward the fat body to induce AMP expression. Regarding to the tumor recognition, we found that matrix metalloproteinase 1 (MMP1) and MMP2 were highly expressed in the tumors. Ectopic expression of MMP2 was associated with AMP induction in the mutants. Furthermore, the basement membrane components in the tumors were reduced and ultimatel...

Drosophila in cancer research: the first fifty tumor suppressor genes

Journal of Cell Science, 1994

In Drosophila, over 50 genes have been identified in which loss-of-function mutations lead to excess cell proliferation in the embryo, in the central nervous system, imaginal discs or hematopoietic organs of the larva, or in the adult gonads. Twenty-two of these genes have been cloned and characterized at the molecular level, and nine of them show clear homology to mammalian genes. Most of these mammalian genes had not been previously implicated in cell proliferation control. Overgrowth in some of the mutants involves conversion to a cell type that, in normal development, shows more cell proliferation than the original cell type. Thus the neurogenic mutants, including Notch, show conversion of epidermal cells to neuroblasts, leading to the 'neurogenic' phenotype of excess nervous tissue. The ovarian tumor mutants show conversion of the female germ line to a cell type resembling the male germ line, which undergoes more proliferation than the female germ line. Mutations of the fa t locus cause hyperplastic overgrowth of imaginal discs, in which the epithelial structure is largely intact. The predicted fat protein product is a giant relative of cadherins, supporting indica tions from human cancer that cadherins play an important role in tumor suppression. Mutations in the lethal(2)giant larvae and lethal(l)discs large genes cause neoplastic over growth of imaginal discs as well as the larval brain. The dig gene encodes a membrane-associated guanylate kinase homolog that is localized at septate junctions between epithelial cells. This protein is a member of a family of homologs that also includes two proteins found at mammalian tight junctions (ZO-1 and ZO-2) and a protein found at mammalian synaptic junctions (PSD-95/SAP90). Genes in which mutations cause blood cell overproduction include aberrant immune response-8, which encodes the RpS6 ribosomal protein and hopscotch, which encodes a putative non-receptor protein tyrosine kinase. The gene products identified by ovarian tumor mutants do not show clear amino acid sequence homology to known proteins. Drosophila provides an opportunity to rapidly identify and characterize tumor suppressor genes, many of which have mammalian homologs that might also be involved in cell proliferation control and tumor suppression.

Transcriptional targets of Drosophila JAK/STAT pathway signalling as effectors of haematopoietic tumour formation

EMBO reports, 2010

Although many signal transduction pathways have been implicated in the development of human disease, the identification of pathway targets and the biological processes that mediate disease progression remains challenging. One such disease-related pathway is the Janus kinase (JAK)/signal transducer and activator of transcription (STAT) cascade whose constitutive misactivation by the JAK2 V617F mutation underlies most human myeloproliferative disorders. Here, we use transcript profiling of Drosophila haemocytelike cells to identify JAK/STAT target genes, combined with an in vivo model for JAK-induced blood cell overproliferation, to identify the main effectors required for haematopoietic tumour development. The identified human homologues of the Drosophila effectors were tested for potential V617F-mediated transcriptional regulation in human HeLa cells and compared with small interfering RNA-derived data, quantify their role in regulating the proliferation of cancer-derived cell lines. Such an inter-species approach is an effective way to identify factors with conserved functions that might be central to human disease.

Tumor models in various Drosophila tissues

WIREs Mechanisms of Disease, 2021

The development of cancer is a complex multistage process. Over the past few decades, the model organism Drosophila melanogaster has been crucial in identifying cancer-related genes and pathways and elucidating mechanisms underlying growth regulation in development. Investigations using Drosophila has yielded new insights into the molecular mechanisms involved in tumor initiation and progression. In this review, we describe various tumor models that have been developed in recent years using different Drosophila tissues, such as the imaginal tissue, the neural tissue, the gut, the ovary, and hematopoietic cells. We discuss underlying genetic alterations, cancer-like characteristics, as well as similarities and key differences among these models. We also discuss how disruptions in stem cell division and differentiation result in tumor formation in diverse tissues, and highlight new concepts developed using the fly model to understand context-dependent tumorigenesis. We further discuss the progress made in Drosophila to explore tumor-host interactions that involve the innate immune response to tumor growth and the cachexia wasting phenotype.

Drosophila Jak/STAT Signaling: Regulation and Relevance in Human Cancer and Metastasis

International Journal of Molecular Sciences, 2018

Over the past three-decades, Janus kinase (Jak) and signal transducer and activator of transcription (STAT) signaling has emerged as a paradigm to understand the involvement of signal transduction in development and disease pathology. At the molecular level, cytokines and interleukins steer Jak/STAT signaling to transcriptional regulation of target genes, which are involved in cell differentiation, migration, and proliferation. Jak/STAT signaling is involved in various types of blood cell disorders and cancers in humans, and its activation is associated with carcinomas that are more invasive or likely to become metastatic. Despite immense information regarding Jak/STAT regulation, the signaling network has numerous missing links, which is slowing the progress towards developing drug therapies. In mammals, many components act in this cascade, with substantial cross-talk with other signaling pathways. In Drosophila, there are fewer pathway components, which has enabled significant dis...