Video report -- cell-based assay

Peters KA, Detmar E, Sepulveda L, Del Valle C, Valsquier R, Ritz A, Rogers SL, Applewhite DA. A Cell-based Assay to Investigate Non-muscle Myosin II Contractility via the Folded-gastrulation Signaling Pathway in Drosophila S2R+ Cells. J Vis Exp. 2018 Aug 19;(138). doi: 10.3791/58325. PubMed PMID: 30176023.

DRSC screen contributes to research report on signaling and lifespan

Sung EJ, Ryuda M, Matsumoto H, Uryu O, Ochiai M, Cook ME, Yi NY, Wang H, Putney JW, Bird GS, Shears SB, Hayakawa Y. Cytokine signaling through Drosophila Mthl10 ties lifespan to environmental stress. Proc Natl Acad Sci U S A. 2017 Dec 11. PMID: 29229844.

From the abstract: "A systems-level understanding of cytokine-mediated, intertissue signaling is one of the keys to developing fundamental insight into the links between aging and inflammation. Here, we employed Drosophila, a routine model for analysis of cytokine signaling pathways in higher animals, to identify a receptor for the growth-blocking peptide (GBP) cytokine. Having previously established that the phospholipase C/Ca2+ signaling pathway mediates innate immune responses to GBP, we conducted a dsRNA library screen for genes that modulate Ca2+ mobilization in Drosophila S3 cells. A hitherto orphan G protein coupled receptor, Methuselah-like receptor-10 (Mthl10), was a significant hit. Secondary screening confirmed specific binding of fluorophore-tagged GBP to both S3 cells and recombinant Mthl10-ectodomain. We discovered that the metabolic, immunological, and stress-protecting roles of GBP all interconnect through Mthl10. This we established by Mthl10 knockdown in three fly model systems: in hemocyte-like Drosophila S2 cells, Mthl10 knockdown decreases GBP-mediated innate immune responses; in larvae, Mthl10 knockdown decreases expression of antimicrobial peptides in response to low temperature; in adult flies, Mthl10 knockdown increases mortality rate following infection with Micrococcus luteus and reduces GBP-mediated secretion of insulin-like peptides. ... We describe how our data offer opportunities for further molecular interrogation of yin and yang between homeostasis and longevity."

Analysis of steroid hormone signaling in 41 Drosophila fly cell lines

Stoiber M, Celniker S, Cherbas L, Brown B, Cherbas P. Diverse Hormone Response Networks in 41 Independent Drosophila Cell Lines. G3 (Bethesda). 2016 Jan 15. pii: g3.115.023366. PMID: 26772746.

From the abstract: "Steroid hormones induce cascades of gene activation and repression with transformative effects on cell fate. Steroid transduction plays a major role in the development and physiology of nearly all metazoan species, and in the progression of the most common forms of cancer. Despite the paramount importance of steroids in developmental and translational biology, a complete map of transcriptional response has not been developed for any hormone. In the case of 20-hydroxyecdysone (ecdysone) in Drosophila melanogaster, these trajectories range from apoptosis to immortalization. We mapped the ecdysone transduction network in a cohort of 41 cell lines, the largest such atlas yet assembled. ... This atlas of steroid response reveals organizing principles of gene regulation by a model type II nuclear receptor and lays the foundation for comprehensive and predictive understanding of the ecdysone transduction network in the fruit fly."

Another paper reporting concern about an RNAi fly library

Any of us using the relevant RNAi stocks should be aware.

Vissers JH, Manning SA, Kulkarni A, Harvey KF. A Drosophila RNAi library modulates Hippo pathway-dependent tissue growth. Nat Commun. 2016 Jan 13;7:10368. PMID: 26758424.
From the abstract: "... Here we investigate an important technical limitation with the widely used VDRC KK RNAi collection. We find that approximately 25% of VDRC KK RNAi lines cause false-positive enhancement of the Hippo pathway, owing to ectopic expression of the Tiptop transcription factor. Of relevance to the broader Drosophila community, ectopic tiptop (tio) expression can also cause organ malformations and mask phenotypes such as organ overgrowth. To enhance the use of the VDRC KK RNAi library, we have generated a D. melanogaster strain that will allow researchers to test, in a single cross, whether their genetic screen of interest will be affected by ectopic tio expression."

Fly cell screen leads to findings relevant to cancer treatment (and its financial impact)

Thomas S, Fisher KH, Snowden JA, Danson SJ, Brown S, Zeidler MP. Methotrexate Is a JAK/STAT Pathway Inhibitor. PLoS One. 2015 Jul 1;10(7):e0130078. PMID: 26131691.

From the abstract: "... The JAK/STAT pathway transduces signals from multiple cytokines and controls haematopoiesis, immunity and inflammation. In addition, pathological activation is seen in multiple malignancies including the myeloproliferative neoplasms (MPNs). Given this, drug development efforts have targeted the pathway with JAK inhibitors such as ruxolitinib. Although effective, high costs and side effects have limited its adoption. Thus, a need for effective low cost treatments remains. ...We used the low-complexity Drosophila melanogaster pathway to screen for small molecules that modulate JAK/STAT signalling. This screen identified methotrexate and the closely related aminopterin as potent suppressors of STAT activation. We show that methotrexate suppresses human JAK/STAT signalling without affecting other phosphorylation-dependent pathways. ... While the JAK1/2 inhibitor ruxolitinib is effective, a £43,200 annual cost precludes widespread adoption. With an annual methotrexate cost of around £32, our findings represent an important development with significant future potential."