Evaluation of Culture Conducive to Academic Success by Gender at a Comprehensive Cancer Center.

INTRODUCTION: The primary objective of this study was to determine whether workplace culture in academic oncology differed by gender, during the COVID-19 pandemic. MATERIALS AND METHODS: We used the Culture Conducive to Women's Academic Success (CCWAS), a validated survey tool, to investigate the academic climate at an NCI-designated Cancer Center. We adapted the CCWAS to be applicable to people of all genders. The full membership of the Cancer Center was surveyed (total faculty = 429). The questions in each of 4 CCWAS domains (equal access to opportunities, work-life balance, freedom from gender bias, and leadership support) were scored using a 5-point Likert scale. Median score and interquartile ranges for each domain were calculated. RESULTS: A total of 168 respondents (men = 58, women = 106, n = 4 not disclosed) submitted survey responses. The response rate was 39% overall and 70% among women faculty. We found significant differences in perceptions of workplace culture by gender, both in responses to individual questions and in the overall score in the following domains: equal access to opportunities, work-life balance, and leader support, and in the total score for the CCWAS. CONCLUSIONS: Our survey is the first of its kind completed during the COVID-19 pandemic at an NCI-designated Cancer Center, in which myriad factors contributed to burnout and workplace challenges. These results point to specific issues that detract from the success of women pursuing careers in academic oncology. Identifying these issues can be used to design and implement solutions to improve workforce culture, mitigate gender bias, and retain faculty.

Cancer Research in 2030: A unique strategic planning process at a comprehensive cancer center.

Following the successful renewal of its Cancer Center Support Grant (CCSG), leadership of the UCSF Helen Diller Comprehensive Cancer Center (HDFCCC) began a strategic planning process. The motivation was to think about where cancer research was going in the future; and with this vision to define a general scientific direction, mission, and priorities. HDFCCC Leadership began discussions about a new strategic plan in early 2018. From these meetings, the theme of "Cancer Research in 2030" arose: that is, what will cancer research look like in 2030? This forward-looking focus was intended to encourage creativity unconfined by a particular institutional structure or grant mechanism. Focusing on the science paved the way for an innovative, actionable, and motivating strategic planning process. Here, we describe the three-phase process, and the various groups involved across the HDFCCC and UCSF. We present the unique framework based on a cells-to-society model and an individual experience perspective, which led to the development of a logic model and ongoing implementation of tactics and tracking progress. We believe that sharing this process and its results will be of value to cancer centers and cancer researchers across the network of NCI comprehensive cancer centers, and cancer research centers in general.

Characterization of Plasmodium falciparum adenylyl cyclase-ß and its role in erythrocytic stage parasites.

The most severe form of human malaria is caused by the parasite Plasmodium falciparum. The second messenger cAMP has been shown to be important for the parasite's ability to infect the host's liver, but its role during parasite growth inside erythrocytes, the stage responsible for symptomatic malaria, is less clear. The P. falciparum genome encodes two adenylyl cyclases, the enzymes that synthesize cAMP, PfACα and PfACß. We now show that one of these, PfACß, plays an important role during the erythrocytic stage of the P. falciparum life cycle. Biochemical characterization of PfACß revealed a marked pH dependence, and sensitivity to a number of small molecule inhibitors. These inhibitors kill parasites growing inside red blood cells. One particular inhibitor is selective for PfACß relative to its human ortholog, soluble adenylyl cyclase (sAC); thus, PfACß represents a potential target for development of safe and effective antimalarial therapeutics.

Structural and physiological phenotypes of disease-linked lamin mutations in C. elegans.

The nuclear lamina is a major structural element of the nucleus and is predominately composed of the intermediate filament lamin proteins. Missense mutations in the human lamins A/C cause a family of laminopathic diseases, with no known mechanistic link between the position of the mutation and the resulting disease phenotypes. The Caenorhabditis elegans lamin (Ce-lamin) is structurally and functionally homologous to human lamins, and recent advances have allowed detailed structural analysis of Ce-lamin filaments both in vitro and in vivo. Here, we studied the effect of laminopathic mutations on Ce-lamin filament assembly in vitro and the corresponding physiological phenotypes in animals. We focused on three disease-linked mutations, Q159K, T164P, and L535P, which have previously been shown to affect lamin structure and nuclear localization. Mutations prevented the proper assembly of Ce-lamin into filament and/or paracrystalline arrays. Disease-like phenotypes were observed in strains expressing low levels of these mutant lamins, including decreased fertility and motility coincident with muscle lesions. In addition, the Q159K- and T164P-expressing strains showed a reduced lifespan. Thus, different disease-linked mutations in Ce-lamin exhibit major effects in vivo and in vitro. Using C. elegans as a model system, a comprehensive analysis of the effects of specific lamin mutations from the level of in vitro filament assembly to the physiology of the organism will help uncover the mechanistic differences between these different lamin mutations.

The nuclear lamina and heterochromatin: a complex relationship.

In metazoan cells, the heterochromatin is generally localized at the nuclear periphery, whereas active genes are preferentially found in the nuclear interior. In the present paper, we review current evidence showing that components of the nuclear lamina interact directly with heterochromatin, which implicates the nuclear lamina in a mechanism of specific gene retention at the nuclear periphery and release to the nuclear interior upon gene activation. We also discuss recent data showing that mutations in lamin proteins affect gene positioning and expression, providing a potential mechanism for how these mutations lead to tissue-specific diseases.

An EDMD mutation in C. elegans lamin blocks muscle-specific gene relocation and compromises muscle integrity.

BACKGROUND: In worms, as in other organisms, many tissue-specific promoters are sequestered at the nuclear periphery when repressed and shift inward when activated. It has remained unresolved, however, whether the association of facultative heterochromatin with the nuclear periphery, or its release, has functional relevance for cell or tissue integrity. RESULTS: Using ablation of the unique lamin gene in C. elegans, we show that lamin is necessary for the perinuclear positioning of heterochromatin. We then express at low levels in otherwise wild-type worms a lamin carrying a point mutation, Y59C, which in humans is linked to an autosomal-dominant form of Emery-Dreifuss muscular dystrophy. Using embryos and differentiated tissues, we track the subnuclear position of integrated heterochromatic arrays and their expression. In LMN-1 Y59C-expressing worms, we see abnormal retention at the nuclear envelope of a gene array bearing a muscle-specific promoter. This correlates with impaired activation of the array-borne myo-3 promoter and altered expression of a number of muscle-specific genes. However, an equivalent array carrying the intestine-specific pha-4 promoter is expressed normally and shifts inward when activated in gut cells of LMN-1 Y59C worms. Remarkably, adult LMN-1 Y59C animals have selectively perturbed body muscle ultrastructure and reduced muscle function. CONCLUSION: Lamin helps sequester heterochromatin at the nuclear envelope, and wild-type lamin permits promoter release following tissue-specific activation. A disease-linked point mutation in lamin impairs muscle-specific reorganization of a heterochromatic array during tissue-specific promoter activation in a dominant manner. This dominance and the correlated muscle dysfunction in LMN-1 Y59C worms phenocopies Emery-Dreifuss muscular dystrophy.

Caenorhabditis elegans as a model system for studying the nuclear lamina and laminopathic diseases.

The nuclear lamina is a protein-rich network located directly underneath the inner nuclear membrane of metazoan nuclei. The components of the nuclear lamina have been implicated in nearly all nuclear functions; therefore, understanding the structural, mechanical, and signal transducing properties of these proteins is crucial. In addition, mutations in many of these proteins cause a wide range of human diseases, the laminopathies. The structure, function, and interaction of the lamina proteins are conserved among metazoans, emphasizing their fundamental roles in the nucleus. Several of the advances in the field of the nuclear lamina have come from studies performed in Caenorhabditis elegans or on C. elegans proteins expressed in vitro. Here, we discuss the current knowledge about the nuclear lamina, including an overview of the technical tools offered by C. elegans that make it a powerful model organism for the study of the nuclear lamina and laminopathic diseases.

A laminopathic mutation disrupting lamin filament assembly causes disease-like phenotypes in Caenorhabditis elegans.

Mutations in the human LMNA gene underlie many laminopathic diseases, including Emery-Dreifuss muscular dystrophy (EDMD); however, a mechanistic link between the effect of mutations on lamin filament assembly and disease phenotypes has not been established. We studied the ΔK46 Caenorhabditis elegans lamin mutant, corresponding to EDMD-linked ΔK32 in human lamins A and C. Cryo-electron tomography of lamin ΔK46 filaments in vitro revealed alterations in the lateral assembly of dimeric head-to-tail polymers, which causes abnormal organization of tetrameric protofilaments. Green fluorescent protein (GFP):ΔK46 lamin expressed in C. elegans was found in nuclear aggregates in postembryonic stages along with LEM-2. GFP:ΔK46 also caused mislocalization of emerin away from the nuclear periphery, consistent with a decreased ability of purified emerin to associate with lamin ΔK46 filaments in vitro. GFP:ΔK46 animals had motility defects and muscle structure abnormalities. These results show that changes in lamin filament structure can translate into disease-like phenotypes via altering the localization of nuclear lamina proteins, and suggest a model for how the ΔK32 lamin mutation may cause EDMD in humans.

The physiological and molecular effects of elevated CO2 levels.

Carbon dioxide (CO2) is an end product of cellular respiration, a process by which organisms including all plants, animals, many fungi and some bacteria obtain energy. CO2 has several physiologic roles in respiration, pH buffering, autoregulation of the blood supply and others. Here we review recent findings from studies in mammalian lung cells, Caenorhabditis elegans and Drosophila melanogaster that help shed light on the molecular sensing and response to hypercapnia.

Molecular details of cAMP generation in mammalian cells: a tale of two systems.

The second messenger cAMP has been extensively studied for half a century, but the plethora of regulatory mechanisms controlling cAMP synthesis in mammalian cells is just beginning to be revealed. In mammalian cells, cAMP is produced by two evolutionary related families of adenylyl cyclases, soluble adenylyl cyclases (sAC) and transmembrane adenylyl cyclases (tmAC). These two enzyme families serve distinct physiological functions. They share a conserved overall architecture in their catalytic domains and a common catalytic mechanism, but they differ in their sub-cellular localizations and responses to various regulators. The major regulators of tmACs are heterotrimeric G proteins, which transduce extracellular signals via G protein-coupled receptors. sAC enzymes, in contrast, are regulated by the intracellular signaling molecules bicarbonate and calcium. Here, we discuss and compare the biochemical, structural and regulatory characteristics of the two mammalian AC families. This comparison reveals the mechanisms underlying their different properties but also illustrates many unifying themes for these evolutionary related signaling enzymes.