scholarly journals Genome-wide RNAi screen for context-dependent tumor suppressors identified using in vivo models for neoplasia in Drosophila

2019 ◽  
Author(s):  
Casper Groth ◽  
Pooja Vaid ◽  
Aditi Khatpe ◽  
Nelchi Prashali ◽  
Avantika Ahiya ◽  
...  

AbstractGenetic approaches in Drosophila have successfully identified many genes involved in regulation of growth control as well as genetic interactions relevant to the initiation and progression of cancer in vivo. Here, we report on large-scale RNAi-based screens to identify potential tumor suppressor genes that interact with known cancer-drivers: The Epidermal Growth Factor Receptor and the Hippo pathway transcriptional cofactor Yorkie. These screens were designed to identify genes whose depletion drove tissue expressing EGFR or Yki from a state of benign overgrowth into neoplastic transformation in vivo. We also report on an independent screen aimed to identify genes whose depletion suppressed formation of neoplastic tumors in an existing EGFR-dependent neoplasia model. Many of the positives identified here are known to be functional in growth control pathways. We also find a number of novel connections to Yki and EGFR driven tissue growth, mostly unique to one of the two. Thus, resources provided here would be useful to all researchers who study negative regulators of growth in the context of activated EGFR and/or Yki and positive regulators of growth in the context of activated EGFR.

2020 ◽  
Vol 10 (9) ◽  
pp. 2999-3008 ◽  
Author(s):  
Casper Groth ◽  
Pooja Vaid ◽  
Aditi Khatpe ◽  
Nelchi Prashali ◽  
Avantika Ahiya ◽  
...  

Abstract Genetic approaches in Drosophila have successfully identified many genes involved in regulation of growth control as well as genetic interactions relevant to the initiation and progression of cancer in vivo. Here, we report on large-scale RNAi-based screens to identify potential tumor suppressor genes that interact with known cancer-drivers: the Epidermal Growth Factor Receptor and the Hippo pathway transcriptional cofactor Yorkie. These screens were designed to identify genes whose depletion drove tissue expressing EGFR or Yki from a state of benign overgrowth into neoplastic transformation in vivo. We also report on an independent screen aimed to identify genes whose depletion suppressed formation of neoplastic tumors in an existing EGFR-dependent neoplasia model. Many of the positives identified here are known to be functional in growth control pathways. We also find a number of novel connections to Yki and EGFR driven tissue growth, mostly unique to one of the two. Thus, resources provided here would be useful to all researchers who study negative regulators of growth during development and cancer in the context of activated EGFR and/or Yki and positive regulators of growth in the context of activated EGFR. Resources reported here are available freely for anyone to use.


2016 ◽  
Vol 216 (1) ◽  
pp. 265-277 ◽  
Author(s):  
Hitoshi Matakatsu ◽  
Seth S. Blair ◽  
Richard G. Fehon

The large protocadherin Fat functions to promote Hippo pathway activity in restricting tissue growth. Loss of Fat leads to accumulation of the atypical myosin Dachs at the apical junctional region, which in turn promotes growth by inhibiting Warts. We previously identified Approximated (App), a DHHC domain palmitoyltransferase, as a negative regulator of Fat signaling in growth control. We show here that App promotes growth by palmitoylating the intracellular domain of Fat, and that palmitoylation negatively regulates Fat function. Independently, App also recruits Dachs to the apical junctional region through protein–protein association, thereby stimulating Dachs’s activity in promoting growth. Further, we show that palmitoylation by App functions antagonistically to phosphorylation by Discs-overgrown, which activates Fat. Together, these findings suggest a model in which App promotes Dachs activity by simultaneously repressing Fat via posttranslational modification and recruiting Dachs to the apical junctional region, thereby promoting tissue growth.


2019 ◽  
Vol 116 (4) ◽  
pp. 1319-1324 ◽  
Author(s):  
Xing Wang ◽  
Yifei Zhang ◽  
Seth S. Blair

The Drosophila protocadherin Fat controls organ size through the Hippo pathway, but the biochemical links to the Hippo pathway components are still poorly defined. We previously identified Dlish, an SH3 domain protein that physically interacts with Fat and the type XX myosin Dachs, and showed that Fat’s regulation of Dlish levels and activity helps limit Dachs-mediated inhibition of Hippo pathway activity. We here characterize a parallel growth control pathway downstream of Fat and Dlish. Using immunoprecipitation and mass spectrometry to search for Dlish partners, we find that Dlish binds the FERM domain growth repressor Expanded (Ex); Dlish SH3 domains directly bind sites in the Ex C terminus. We further show that, in vivo, Dlish reduces the subapical accumulation of Ex, and that loss of Dlish blocks the destabilization of Ex caused by loss of Fat. Moreover, Dlish can bind the F-box E3 ubiquitin ligase Slimb and promote Slimb-mediated ubiquitination of Expanded in vitro. Both the in vitro and in vivo effects of Dlish on Ex require Slimb, strongly suggesting that Dlish destabilizes Ex by helping recruit Slimb-containing E3 ubiquitin ligase complexes to Ex.


2012 ◽  
Vol 447 (1) ◽  
pp. 93-102 ◽  
Author(s):  
Ming Ji ◽  
Shuping Yang ◽  
Yuanhong Chen ◽  
Ling Xiao ◽  
Lin Zhang ◽  
...  

KIBRA (kidney- and brain-expressed protein) is a novel regulator of the Hippo pathway, which controls tissue growth and tumorigenesis by regulating both cell proliferation and apoptosis. In mammals, KIBRA is associated with memory performance. The physiological function and regulation of KIBRA in non-neuronal cells remain largely unclear. We reported recently that KIBRA is phosphorylated by the mitotic kinases Aurora-A and -B. In the present study, we have expanded our analysis of KIBRA's role in cell-cycle progression. We show that KIBRA is also phosphorylated by CDK1 (cyclin-dependent kinase 1) in response to spindle damage stress. We have identified KIBRA Ser542 and Ser931 as main phosphorylation sites for CDK1 both in vitro and in vivo. Moreover, we found that the CDC (cell division cycle) 14A/B phosphatases associate with KIBRA, and CDK1-non-phosphorylatable KIBRA has greatly reduced interaction with CDC14B. CDC14A/B dephosphorylate CDK1-phosphorylated KIBRA in vitro and in cells. By using inducible-expression cell lines, we show further that phospho-regulation of KIBRA by CDK1 and CDC14 is involved in mitotic exit under spindle stress. Our results reveal a new mechanism through which KIBRA regulates cell-cycle progression.


2020 ◽  
Author(s):  
Yannick Mesrouze ◽  
Gustavo Aguilar ◽  
Fedir Bokhovchuk ◽  
Typhaine Martin ◽  
Clara Delaunay ◽  
...  

AbstractThe most downstream elements of the Hippo pathway, the TEAD transcription factors, are regulated by several cofactors, such as Vg/VGLL1-3. Earlier findings on human VGLL1 and here on human VGLL3 show that these proteins interact with TEAD via a conserved amino acid motif called the TONDU domain. Surprisingly, our studies reveal that the TEAD-binding domain of Drosophila Vg and of human VGLL2 is more complex and contains an additional structural element, an Ω-loop, that contributes to TEAD binding and in vivo function. To explain this unexpected structural difference between proteins from the same family, we propose that, after the genome-wide duplications at the origin of vertebrates, the Ω-loop present in an ancestral VGLL gene has been lost in some VGLL variants. These findings illustrate how structural and functional constraints can guide the evolution of transcriptional cofactors to preserve their ability to compete with other cofactors for binding to transcription factors.


2019 ◽  
Vol 2 (4) ◽  
pp. e201900381 ◽  
Author(s):  
Stephan U Gerlach ◽  
Moritz Sander ◽  
Shilin Song ◽  
Héctor Herranz

One of the fundamental issues in biology is understanding how organ size is controlled. Tissue growth has to be carefully regulated to generate well-functioning organs, and defects in growth control can result in tumor formation. The Hippo signaling pathway is a universal growth regulator and has been implicated in cancer. In Drosophila, the Hippo pathway acts through the miRNA bantam to regulate cell proliferation and apoptosis. Even though the bantam targets regulating apoptosis have been determined, the target genes controlling proliferation have not been identified thus far. In this study, we identify the gene tribbles as a direct bantam target gene. Tribbles limits cell proliferation by suppressing G2/M transition. We show that tribbles regulation by bantam is central in controlling tissue growth and tumorigenesis. We expand our study to other cell cycle regulators and show that deregulated G2/M transition can collaborate with oncogene activation driving tumor formation.


2021 ◽  
Vol 23 (Supplement_6) ◽  
pp. vi164-vi164
Author(s):  
Gabrielle Price ◽  
Sweta Sudhir ◽  
Concetta Brusco ◽  
Alexandros Bouras ◽  
Nadejda Tsankova ◽  
...  

Abstract Glioblastoma (GBM) has the highest mortality rate, incidence, and therapy resistance of all primary brain tumors. Deregulation of the epidermal growth factor receptor (EGFR) has been implicated in GBM tumorigenesis. The expression of EGFR has been linked to hippo pathway transcriptional co-activators YAP and TAZ that bind to TEAD co-factors to drive the transcription of target genes. The convergence of EGFR signaling and the hippo pathway regulates stem cell programs, including proliferation, survival, and self-renewal. Verteporfin (VP), is an FDA-approved drug for photodynamic therapy (PDT) of macular degeneration. VP has been shown to have antitumor effects both in vitro and in vivo in GBM preclinical models. As a porphyrin derivative, VP can also exert therapeutic and photodynamic effects in the presence of 689 nm light; however, the efficacy of VP-PDT has not been explored in GBM. Our results indicate for the first time that VP-PDT reduces GBM cell viability to a greater extent than VP treatment alone (viability — 0.7 uM VP: 97%, 0.7 uM VP-PDT: 46%). The antitumor effects of VP-PDT are two pronged involving 1) inhibition of live cell dynamics, including migration and intravasation, by downregulating hippo pathway constituents YAP, TAZ and TEAD and transcriptional target EGFR and 2) induction of programmed cell death by reactive oxygen species. Our results suggest that VP-PDT can be a potential avenue for treating these incurable tumors.


eLife ◽  
2015 ◽  
Vol 4 ◽  
Author(s):  
Sobhika Agarwala ◽  
Sandra Duquesne ◽  
Kun Liu ◽  
Anton Boehm ◽  
Lin Grimm ◽  
...  

During development, proliferation must be tightly controlled for organs to reach their appropriate size. While the Hippo signaling pathway plays a major role in organ growth control, how it senses and responds to increased cell density is still unclear. In this study, we use the zebrafish lateral line primordium (LLP), a group of migrating epithelial cells that form sensory organs, to understand how tissue growth is controlled during organ formation. Loss of the cell junction-associated Motin protein Amotl2a leads to overproliferation and bigger LLP, affecting the final pattern of sensory organs. Amotl2a function in the LLP is mediated together by the Hippo pathway effector Yap1 and the Wnt/β-catenin effector Lef1. Our results implicate for the first time the Hippo pathway in size regulation in the LL system. We further provide evidence that the Hippo/Motin interaction is essential to limit tissue size during development.


2007 ◽  
Vol 21 (21) ◽  
pp. 2747-2761 ◽  
Author(s):  
B. Zhao ◽  
X. Wei ◽  
W. Li ◽  
R. S. Udan ◽  
Q. Yang ◽  
...  

2021 ◽  
Vol 12 (12) ◽  
Author(s):  
Yin Zhang ◽  
Ye-Ya Tan ◽  
Pei-Pei Chen ◽  
Hui Xu ◽  
Shu-Juan Xie ◽  
...  

AbstractLiver development is a highly complex process that is regulated by the orchestrated interplay of epigenetic regulators, transcription factors, and microRNAs (miRNAs). Owing to the lack of global in vivo targets of all miRNAs during liver development, the mechanisms underlying the dynamic control of hepatocyte differentiation by miRNAs remain elusive. Here, using Argonaute (Ago) high-throughput sequencing of RNA isolated by crosslinking immunoprecipitation (HITS-CLIP) in the mouse liver at different developmental stages, we characterized massive Ago-binding RNAs and obtained a genome-wide map of liver miRNA-mRNA interactions. The dynamic changes of five clusters of miRNAs and their potential targets were identified to be differentially involved at specific stages, a dozen of high abundant miRNAs and their epigenetic regulation by super-enhancer were found during liver development. Remarkably, miR-122, a liver-specific and most abundant miRNA in newborn and adult livers, was found by its targetome and pathway reporter analyses to regulate the Hippo pathway, which is crucial for liver size control and homeostasis. Mechanistically, we further demonstrated that miR-122 negatively regulates the outcomes of the Hippo pathway transcription factor TEAD by directly targeting a number of hippo pathway regulators, including the coactivator TAZ and a key factor of the phosphatase complex PPP1CC, which contributes to the dephosphorylation of YAP, another coactivator downstream of the Hippo pathway. This study identifies for the first time the genome-wide miRNA targetomes during mouse liver development and demonstrates a novel mechanism of terminal differentiation of hepatocytes regulated by the miR-122/Hippo pathway in a coordinated manner. As the Hippo pathway plays important roles in cell proliferation and liver pathological processes like inflammation, fibrosis, and hepatocellular carcinoma (HCC), our study could also provide a new insight into the function of miR-122 in liver pathology.


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