Regulation of GPR54 signaling by GRK2 and {beta}-arrestin

Kisspeptin and its receptor, GPR54, are major regulators of the hypothalamic-pituitary-gonadal axis as well as regulators of human placentation and tumor metastases. GPR54 is a G(q/11)-coupled G protein-coupled receptor (GPCR), and activation by kisspeptin stimulates phosphatidy linositol 4, 5-biphosphate hydrolysis, Ca(2+) mobilization, arachidonic acid release, and ERK1/2 MAPK phosphorylation. Physiological evidence suggests that GPR54 undergoes agonist-dependent desensitization, but underlying molecular mechanisms are unknown. Furthermore, very little has been reported on the early events that regulate GPR54 signaling. The lack of information in these important areas led to this study. Here we report for the first time on the role of GPCR serine/threonine kinase (GRK)2 and beta-arrestin in regulating GPR54 signaling in human embryonic kidney (HEK) 293 cells, a model cell system for studying the molecular regulation of GPCRs, and genetically modified MDA MB-231 cells, an invasive breast cancer cell line expressing about 75% less beta-arrestin-2 than the control cell line. Our study reveals that in HEK 293 cells, GPR54 is expressed both at the plasma membrane and intracellularly and also that plasma membrane expression is regulated by cytoplasmic tail sequences. We also demonstrate that GPR54 exhibits constitutive activity, internalization, and association with GRK2 and beta- arrestins-1 and 2 through sequences in the second intracellular loop and cytoplasmic tail of the receptor. We also show that GRK2 stimulates the desensitization of GPR54 in HEK 293 cells and that beta-arrestin-2 mediates GPR54 activation of ERK1/2 in MDA-MB-231 cells. The significance of these findings in developing molecular-based therapies for treating certain endocrine-related disorders is discussed.

Choosing Wisely Canada Cancer List: Ten Low-Value or Harmful Practices That Should Be Avoided In Cancer Care

Using knowledge translation and exchange efforts, this list should empower patients with cancer and physicians to participate in a targeted conversation about the appropriateness and quality of individual patient care.

Guidance for management of cancer surgery during the COVID-19 pandemic

Summary

During the coronavirus disease 2019 (COVID-19) pandemic, delaying lifesaving cancer surgeries must be done with extreme caution and thoughtfulness. Modelling indicates that delays in high-risk cancer surgeries beyond 6 weeks could affect long-term outcomes for thousands of Canadians. Consequently, it is possible that postponing cancer surgery without consideration of its implications could cost more lives than can be saved by diverting all surgical resources to COVID-19. This article provides general guidance on supporting curative surgical treatment where appropriate and with available resources.

Improving the Quality of Outcomes of Complex Cancer Surgery Through National Standards: Lessons From Canada

Background and context: Evidence shows there is wide variability in cancer care service delivery and patient outcomes. Outcomes of complex surgery can be improved by following standards that outline optimal ways to plan, organize and deliver surgical care. While some cancer surgeries are associated with a high risk of adverse outcomes, they also offer the best option for a cure. To ensure optimal patient outcomes, deliberate approaches are needed to standardize the organization of complex care surgeries. Aim: Leverage the expertise of specialty-based and multidisciplinary communities to develop pan-Canadian standards of practice as a means to elevate the delivery of oncologic surgery in Canada. Strategy/Tactics: A phased, multimodal qualitative and quantitative approach was undertaken to develop evidence-based consensus standards for best practice in complex surgery, through the analysis of administrative data to examine access and outcomes of complex, advanced-care surgery and discussion with public representatives to explore trade-offs for reorganizing cancer surgery. Results informed a literature review to identify best practices in complex surgery. Expert panels were convened with disease specific specialty surgeons to inform the development of evidence-informed consensus standards. Draft standards were finalized after targeted review and validation by a wider community of healthcare professionals. Program/Policy process: The standards were endorsed by national professional organizations. An audit was conducted with all surgical programs in Canada to assess pan-Canadian compliance with the standards. Barriers to compliance were tracked to identify areas where local, regional or national activity could support quality initiatives. Outcomes: National standards were developed and highlighted: surgeon criteria, practice settings, and quality improvement. These comprehensive standards provide actionable recommendations that can be tailored to meet local needs. The standards will help organize care in way that maximizes patient outcomes while maintaining reasonable access to care. This work reflects a Canadian approach to a global problem around appropriate delivery of cancer surgical services and facilitates international conversations to mobilize effective knowledge transfer and best practices. What was learned: • Development of national standards is an iterative process that requires upfront buy-in from surgeons, multidisciplinary communities and national associations. Lessons learned from this initiative can support development of international demonstration projects and can help model a process that others could use. • Mechanisms to enhance knowledge of the optimal organization of complex surgery services requires multifaceted and sustained attention. Thoughtful exploration of how surgical care interfaces with other treatment modalities is paramount to ensure a seamless patient journey.

The Choosing Wisely Canada cancer initiative

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Background: Choosing Wisely Canada is a campaign modelled after Choosing Wisely in the USA and aims, through a pan-Canadian cancer physician-based consensus process, to identify a list of low value or harmful cancer services/practices frequently used in Canada. The following describes the approach taken for this work related to cancer in Canada. Methods: A Task Force approach was used, facilitated by the Canadian Partnership Against Cancer (CPAC), and included representation from the Canadian Society of Surgical Oncology, Canadian Association of Medical Oncologists, and Canadian Association of Radiation Oncology, and an expert advisor. The methodology included four phases: (1) identify potentially relevant items and a framework for their subsequent selection; (2) develop a long list; (3) refine and reduce the long list to a short list; and (4) select and endorse a final list of low value or harmful cancer practices. Phases 2–4 followed a framework-driven consensus process and used a series of electronic surveys and voting processes. Results: For Phase 1, 66 cancer relevant practices were initially identified. The framework for subsequent selection included: (1) the size of population to which the practice is relevant; (2) frequency of use in Canada; (3) cost; (4) evidence of low value/harm; and (5) potential for change in use of the practice. The long list (41 practices) was refined and reduced to a short list of 19 practices and a final list including 10 practices. Of these, 5 are completely new, and 3 are revisions/adaptations practices from USA Choosing Wisely. Of the 10 practices, 6 are involve multiple disease sites, while 4 practices are disease-site specific. One practice relates to diagnosis, 6 are treatment- focussed, 2 target surveillance/survivorship, while one practice spans the cancer continuum from diagnosis through survivorship. Conclusions: Through CPAC facilitation, the collective input and work of three professional oncology societies informed this initiative. The content of the final list will be officially released through Choosing Wisely Canada in October 2014, and will be fully revealed at the ASCO Quality Care Symposium.