The Concise Guide to PHARMACOLOGY 2023/24: Introduction and Other Protein Targets

The Concise Guide to PHARMACOLOGY 2023/24 is the sixth in this series of biennial publications. The Concise Guide provides concise overviews, mostly in tabular format, of the key properties of approximately 1800 drug targets, and about 6000 interactions with about 3900 ligands. There is an emphasis on selective pharmacology (where available), plus links to the open access knowledgebase source of drug targets and their ligands (www.guidetopharmacology.org), which provides more detailed views of target and ligand properties. Although the Concise Guide constitutes almost 500 pages, the material presented is substantially reduced compared to information and links presented on the website. It provides a permanent, citable, point-in-time record that will survive database updates. The full contents of this section can be found at http://onlinelibrary.wiley.com/doi/10.1111/bph.16176. In addition to this overview, in which are identified 'Other protein targets' which fall outside of the subsequent categorisation, there are six areas of focus: G protein-coupled receptors, ion channels, nuclear hormone receptors, catalytic receptors, enzymes and transporters. These are presented with nomenclature guidance and summary information on the best available pharmacological tools, alongside key references and suggestions for further reading. The landscape format of the Concise Guide is designed to facilitate comparison of related targets from material contemporary to mid-2023, and supersedes data presented in the 2021/22, 2019/20, 2017/18, 2015/16 and 2013/14 Concise Guides and previous Guides to Receptors and Channels. It is produced in close conjunction with the Nomenclature and Standards Committee of the International Union of Basic and Clinical Pharmacology (NC-IUPHAR), therefore, providing official IUPHAR classification and nomenclature for human drug targets, where appropriate.

THE CONCISE GUIDE TO PHARMACOLOGY 2021/22: Introduction and Other Protein Targets

The Concise Guide to PHARMACOLOGY 2021/22 is the fifth in this series of biennial publications. The Concise Guide provides concise overviews, mostly in tabular format, of the key properties of nearly 1900 human drug targets with an emphasis on selective pharmacology (where available), plus links to the open access knowledgebase source of drug targets and their ligands (www.guidetopharmacology.org), which provides more detailed views of target and ligand properties. Although the Concise Guide constitutes over 500 pages, the material presented is substantially reduced compared to information and links presented on the website. It provides a permanent, citable, point‐in‐time record that will survive database updates. The full contents of this section can be found at http://onlinelibrary.wiley.com/doi/bph.15537. In addition to this overview, in which are identified ‘Other protein targets’ which fall outside of the subsequent categorisation, there are six areas of focus: G protein‐coupled receptors, ion channels, nuclear hormone receptors, catalytic receptors, enzymes and transporters. These are presented with nomenclature guidance and summary information on the best available pharmacological tools, alongside key references and suggestions for further reading. The landscape format of the Concise Guide is designed to facilitate comparison of related targets from material contemporary to mid‐2021, and supersedes data presented in the 2019/20, 2017/18, 2015/16 and 2013/14 Concise Guides and previous Guides to Receptors and Channels. It is produced in close conjunction with the Nomenclature and Standards Committee of the International Union of Basic and Clinical Pharmacology (NC‐IUPHAR), therefore, providing official IUPHAR classification and nomenclature for human drug targets, where appropriate.

Concerted cell and in vivo screen for pancreatic ductal adenocarcinoma (PDA) chemotherapeutics

PDA is a major cause of US cancer-related deaths. Oncogenic Kras presents in 90% of human PDAs. Kras mutations occur early in pre-neoplastic lesions but are insufficient to cause PDA. Other contributing factors early in disease progression include chronic pancreatitis, alterations in epigenetic regulators, and tumor suppressor gene mutation. GPCRs activate heterotrimeric G-proteins that stimulate intracellular calcium and oncogenic Kras signaling, thereby promoting pancreatitis and progression to PDA. By contrast, Rgs proteins inhibit Gi/q-coupled GPCRs to negatively regulate PDA progression. Rgs16::GFP is expressed in response to caerulein-induced acinar cell dedifferentiation, early neoplasia, and throughout PDA progression. In genetically engineered mouse models of PDA, Rgs16::GFP is useful for pre-clinical rapid in vivo validation of novel chemotherapeutics targeting early lesions in patients following successful resection or at high risk for progressing to PDA. Cultured primary PDA cells express Rgs16::GFP in response to cytotoxic drugs. A histone deacetylase inhibitor, TSA, stimulated Rgs16::GFP expression in PDA primary cells, potentiated gemcitabine and JQ1 cytotoxicity in cell culture, and Gem + TSA + JQ1 inhibited tumor initiation and progression in vivo. Here we establish the use of Rgs16::GFP expression for testing drug combinations in cell culture and validation of best candidates in our rapid in vivo screen.

Abstract 5525: Rgs8 and Rgs16 protect against pancreatitis and PDA progression

Pancreatic ductal adenocarcinoma (PDA) has the highest death rate among major cancers, and new treatments are desperately needed. The mice we developed in this study, KCR8-16, are an excellent mouse model for identification, characterization, and in vivo validation of novel PDA therapeutics. Kras oncogenic mutations (e.g., KrasG12D) are found in over 90% of human PDA. Kras can be activated by protein kinase and G-protein coupled receptor (GPCR) signaling. Regulator of G-protein signaling (Rgs) proteins regulate GPCR signaling by accelerating the GTPase activity of Gq- and Gi class alpha subunits. Activating alleles of Gq that are resistant to Rgs inhibition are found in benign precursors of PDA in humans. We previously reported that Rgs8 and Rgs16 are in vivo reporters of Kras activity in pancreatic intraepithelial neoplasia (PanIN), intraductal papillary mucinous neoplasm (IPMN), and PDA progression in KIC;Rgs16::GFP mice (p48::Cre/+; KrasG12D/+; Cdkn2af/f; Rgs16GFP ) (DMM 8, 2015). To identify the role of Rgs 8 and 16 in PDA, we crossed the Rgs8-16 double knockout into pancreas-specific KrasG12D (KC) mutant mice (termed KCR8-16). We found that deletion of Rgs8 and Rgs16 in KC accelerated PDA progression. Additional pancreatic stress evoked by caerulein treatment caused immediate and pancreas-wide progression to PDA in KCR8-16 mice. Our study suggests that Rgs8 and Rgs16 act as tumor-suppressor genes in PDA initiation and progression. Moreover, KCR8-16 and KIC;Rgs16::GFP mice can be used as an excellent model for identification and rapid in vivo validation of PDA therapeutics.

Citation Format: Shreoshi Pal Choudhuri, Yalda Zolghadri, Luke Mascarenhas, Thomas Wilkie. Rgs8 and Rgs16 protect against pancreatitis and PDA progression [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 5525.

Abstract 5518: Rgs8 and Rgs16 are tumor suppressor genes in mouse pancreatic ductal adenocarcinoma

We have identified regulators of G protein signaling (Rgs8 and Rgs16) as a new class of tumor suppressor genes in a mouse model of pancreatic ductal adenocarcinoma (PDA). PDA is the 3rd leading cause of cancer related deaths in the United States. Kras mutations (e.g. KrasG12D) are associated with over 90% of human PDA and are an early event in the multistep process leading to PDA. Kras can be activated by protein kinase and G-Protein Coupled Receptor (GPCR) signaling. Rgs proteins regulate GPCR signaling by accelerating the GTPase activity of Gq- and Gi class alpha subunits. Activating alleles of Gq that are resistant to Rgs inhibition are associated with PDA in humans. We found Rgs8 and Rgs16 are in vivo reporters of Kras activity in pancreatic intraepithelial neoplasia (PanIN), intraductal papillary mucinous neoplasm (IPMN), and PDA progression (DMM 8, 2015). Rgs8 and Rgs16 are expressed in PanIN and IPMN, precursors of PDA, in KC mice (LSL-KrasG12D; p48::Cre). To test if Rgs8-16 function as tumor suppressor genes, we crossed the Rgs8-16 double knockout into KC (termed KCR8-16) mice. Compared to KC, PDA initiates earlier, is more aggressive, and KCR8-16 mice die earlier. Our study suggests that Rgs8 and Rgs16 control Kras-dependent PDA initiation and progression.

Note: This abstract was not presented at the meeting.

Citation Format: Shreoshi Pal Choudhuri, Yalda Zolghadri, Luke Mascarenhas, Ozhan Ocal, Thomas Wilkie. Rgs8 and Rgs16 are tumor suppressor genes in mouse pancreatic ductal adenocarcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 5518. doi:10.1158/1538-7445.AM2017-5518

A rapid in vivo screen for pancreatic ductal adenocarcinoma therapeutics

Pancreatic ductal adenocarcinoma (PDA) is the fourth leading cause of cancer-related deaths in the United States, and is projected to be second by 2025. It has the worst survival rate among all major cancers. Two pressing needs for extending life expectancy of affected individuals are the development of new approaches to identify improved therapeutics, addressed herein, and the identification of early markers. PDA advances through a complex series of intercellular and physiological interactions that drive cancer progression in response to organ stress, organ failure, malnutrition, and infiltrating immune and stromal cells. Candidate drugs identified in organ culture or cell-based screens must be validated in preclinical models such as KIC (p48(Cre);LSL-Kras(G12D);Cdkn2a(f/f)) mice, a genetically engineered model of PDA in which large aggressive tumors develop by 4 weeks of age. We report a rapid, systematic and robust in vivo screen for effective drug combinations to treat Kras-dependent PDA. Kras mutations occur early in tumor progression in over 90% of human PDA cases. Protein kinase and G-protein coupled receptor (GPCR) signaling activates Kras. Regulators of G-protein signaling (RGS) proteins are coincidence detectors that can be induced by multiple inputs to feedback-regulate GPCR signaling. We crossed Rgs16::GFP bacterial artificial chromosome (BAC) transgenic mice with KIC mice and show that the Rgs16::GFP transgene is a Kras(G12D)-dependent marker of all stages of PDA, and increases proportionally to tumor burden in KIC mice. RNA sequencing (RNA-Seq) analysis of cultured primary PDA cells reveals characteristics of embryonic progenitors of pancreatic ducts and endocrine cells, and extraordinarily high expression of the receptor tyrosine kinase Axl, an emerging cancer drug target. In proof-of-principle drug screens, we find that weanling KIC mice with PDA treated for 2 weeks with gemcitabine (with or without Abraxane) plus inhibitors of Axl signaling (warfarin and BGB324) have fewer tumor initiation sites and reduced tumor size compared with the standard-of-care treatment. Rgs16::GFP is therefore an in vivo reporter of PDA progression and sensitivity to new chemotherapeutic drug regimens such as Axl-targeted agents. This screening strategy can potentially be applied to identify improved therapeutics for other cancers.

Abstract LB-130: Reporter genes for a rapid in vivo screen of PDA therapeutics are required for energy homeostasis in pancreatic cancer-associated malnutrition

Pancreatic ductal adenocarcinoma (PDA) is the 4th leading cause of cancer related deaths. Limited progress in developing effective therapy for PDA is partially due to the lack of a robust in vivo screen for effective drug combinations. Kras mutations (e.g. KrasG12D) are found in over 90% of human PDA and occur early in tumor progression. G Protein Coupled Receptor (GPCR) and protein kinase signaling can initiate Ras activation. Regulators of G-protein Signaling (RGS) proteins are coincidence detectors of Ras activation that feedback regulate, by virtue of their GTPase Activating Protein (GAP) activity, the intensity and duration of Gi- and Gq-coupled GPCR signaling. RGS-resistant mutations in Gq have been associated with PDA. We show a Rgs16::GFP transgene is a KrasG12D-dependent marker of all stages of neoplasia in the LSL-KrasG12D; Cdkn2af/f; p48Cre (KIC) mice. GFP is proportional to and coincident with tumor burden. Although KrasG12D is expressed in embryonic pancreas progenitor cells and in all mature acinar cells, Rgs16::GFP expression in tumors first emerges in ductal PanINs as early as 12 days post birth. The receptor tyrosine kinase Axl is highly expressed in PDA progenitor cells. The Gas6 ligand evokes Axl signaling in epithelial progenitor cells and contributes to activation of KrasG12D, PDA initiation and progression. In a proof-of-principle for drug screens, we determined that warfarin, which blocks maturation of Gas6, an Axl agonist, combined with the standard of care Gemcitabine and Abraxane (GA), significantly reduced PDA progression.

In humans, partial pancreatic deficiency often precedes pancreatic cancer. Pancreatic insufficiency develops by 5 weeks in KC (LSL-KrasG12D;p48Cre) mice that express KrasG12D in all pancreas cells. KrasG12D, in the context of wild type Cdkn2a, causes dedifferentiation of acinar cells and a drastic reduction in digestive enzymes secreted by the pancreas. KC mice become malnourished but can survive over one year before succumbing to PDA. We find Intraductal Papillary Mucinous Neoplasm (IPMN) in KC mice express Rgs16::GFP by 2 weeks of age. We crossed the Rgs8-16 double knockout into KC (KC-R) mice to test if Rgs8-16 are tumor suppressor genes. Most KC-R mice die before 4 months of age because they can not maintain energy homeostasis - Rgs8-16 are required in liver to conserve energy utilization in malnourished mice. The effects of Rgs8-16 deficiency on exocrine pancreas function, acinar-to-ductal metaplasia (ADM), apoptosis and tumor progression in KC-R mice are under investigation. As a reporter gene, Rgs16::GFP faithfully tracks PDA progression and sensitivity to new drug regimens that inhibit KrasG12D mediated oncogenesis. Supported by NCI CA161624.

Citation Format: Ozhan Ocal, Yalda Zolghadri, Galvin H. Swift, Rolf A. Brekken, Thomas M. Wilkie. Reporter genes for a rapid in vivo screen of PDA therapeutics are required for energy homeostasis in pancreatic cancer-associated malnutrition. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr LB-130. doi:10.1158/1538-7445.AM2015-LB-130

Achillea Millefolium L. Hydro- Alcoholic Extract Protects Pancreatic Cells by Down Regulating IL- 1β and iNOS Gene Expression in Diabetic Rats

Interleukin-1β (IL-1β) has a role in β- cell destruction in autoimmune diabetes by stimulating the expression of inducible nitric oxide synthase (iNOS) that generates the free radical nitric oxide. We aimed to investigate the effect of Achillea millefolium L, as a traditional hypoglycemic agent, on IL-1β and iNOS gene expression of pancreatic tissue in the STZ- induced diabetic rats. Forty adult male Wistar rats were randomly divided into four groups: 1. diabetic control; 2. diabetic rats treated with Achillea millefolium L. extract; 3. normal rats received only extract and 4. negative control (n= 10 each). Diabetes was induced by single i.p. injection of 45 mg/ kg streptozotocin (STZ). Rats in groups 2 and 3 were treated with i.p. injection of Achillea millefolium L. extract (100 mg/ kg/ day) for 14 days. Body weight, serum glucose and insulin levels were assayed at baseline and on days 3, 7, 10 and 14 of the experiment. Finally, the quantity of pancreatic IL-1β and iNOS mRNA was determined by real- time PCR. The mRNA expression level of IL-1β and iNOS genes, was significantly (p<0.001) increased in diabetic rats of group 1. Treatment with Achillea millefolium L. caused a significant (p<0.01) reduction in both IL-1β and iNOS genes expression. Moreover, rats in group 2 had higher insulin level associated with lower glucose level and higher body weight compared to control diabetic group. It seems that beneficial effect of Achillea millefolium L. on STZ- induced diabetes is at least partly due to amelioration of IL-1β and iNOS gene over expression which can have a β-cell protective effect.