A Novel Gain-of-Function Mutant of the Cyclic GMP-Dependent Protein Kinase egl-4 Affects Multiple Physiological Processes in Caenorhabditis elegans

cGMP-dependent protein kinases are key intracellular transducers of cell signaling. We identified a novel dominant mutation in the C. elegans egl-4 cGMP-dependent protein kinase (PKG) and show that this mutation causes increased normal gene activity although it is associated with a reduced EGL-4 protein level. Prior phenotypic analyses of this gain-of-function mutant demonstrated a reduced longevity and a reduced feeding behavior when the animals were left unperturbed. We characterize several additional phenotypes caused by increased gene activity of egl-4. These phenotypes include a small body size, reduced locomotion in the presence of food, a pale intestine, increased intestinal fat storage, and a decreased propensity to form dauer larvae. The multiple phenotypes of egl-4 dominant mutants are consistent with an instructive signaling role of PKG to control many aspects of animal physiology. This is among the first reported gain-of-function mutations in this enzyme of central physiological importance. In a genetic screen we have identified extragenic suppressors of this gain-of-function mutant. Thus, this mutant promises to be a useful tool for identifying downstream targets of PKG

Prognostic value of the “surprise question” among UPMC Hillman Cancer Center patients with select stage IV cancer diagnoses.

25 Background: The “Surprise Question” — Would I be surprised if this patient died in the next 12 months? — was developed to help clinicians predict when patients are nearing the end of life. Limited data has shown that the “Surprise Question” is modestly predictive of mortality (CMAJ 2017 Apr 3;189(13):E484-E493), though its performance seems to be superior among cancer patients (Palliat Med 2014 Jul;28(7):959-964). Via Oncology Pathways, a platform used by UPMC Hillman Cancer Center and other institutions nationwide to guide treatment decisions, asks physicians the “Surprise Question” when a new treatment plan is implemented for patients with metastatic cancer. We assessed the “Surprise Question’s” ability to predict survival among Hillman Cancer Center patients with select stage IV diagnoses. Methods: We queried the UPMC Hillman Cancer Center Registry Information and Reporting Services for cases of colorectal, non-small cell lung, prostate, pancreatic, and breast cancer with clinic visits between 1/1/2016 and 12/31/2017 and residence in Allegheny County, the primary referral base for the UPMC Hillman Cancer Center network’s flagship facility. Results: The “Surprise Question” was completed for 1,584 patients with metastatic disease of the 5,330 patients that were screened. “No” was the response for 891 patients (56.3%). Mortality at 12 months for patients for whom the answer to the “Surprise Question” was “no” was 63.1%, compared to 32.5% for patients for whom the answer was “yes” (P &lt; 0.0001). The sensitivity of the “Surprise Question” was 71.4% (95% CI 69.0 – 73.8%), and the specificity was 58.7% (95% CI 56.3 – 61.0%). The positive predictive value was 63.1% (95% CI 60.9 – 65.2%) and negative predictive value 67.5% (64.8% – 70.2%). Finally, the positive likelihood ratio was 1.73 (95% CI 1.58 – 1.89) and negative likelihood ratio 0.49 (0.43 – 0.55). Conclusions: While a “no” response to the “Surprise Question” for UPMC oncology patients with select stage IV diagnoses was more likely to predict 12-month mortality than a “yes” response, the “Surprise Question” was only modestly predictive of 12-month mortality. Future work will focus on determining if there are patient populations for whom the “Surprise Question” is more predictive and assessing the ability of the “Surprise Question” to predict other clinical outcomes, such as ED visits and hospitalizations. </jats:p

The Caenorhabditis elegans ekl (Enhancer of ksr-1 Lethality) Genes Include Putative Components of a Germline Small RNA Pathway

A canonical Ras–ERK signaling pathway specifies the fate of the excretory duct cell during Caenorhabditis elegans embryogenesis. The paralogs ksr-1 and ksr-2 encode scaffolding proteins that facilitate signaling through this pathway and that act redundantly to promote the excretory duct fate. In a genomewide RNAi screen for genes that, like ksr-2, are required in combination with ksr-1 for the excretory duct cell fate, we identified 16 “ekl” (enhancer of ksr-1 lethality) genes that are largely maternally required and that have molecular identities suggesting roles in transcriptional or post-transcriptional gene regulation. These include the Argonaute gene csr-1 and a specific subset of other genes implicated in endogenous small RNA processes, orthologs of multiple components of the NuA4/Tip60 histone acetyltransferase and CCR4/NOT deadenylase complexes, and conserved enzymes involved in ubiquitination and deubiquitination. The identification of four small RNA regulators (csr-1, drh-3, ego-1, and ekl-1) that share the Ekl phenotype suggests that these genes define a functional pathway required for the production and/or function of particular germline small RNA(s). These small RNAs and the other ekl genes likely control the expression of one or more regulators of Ras–ERK signaling that function at or near the level of kinase suppressor of Ras (KSR)