Sigma Receptor (σR) Ligands with Antiproliferative and Anticancer Activity (original) (raw)

Recent Advances in the Development of Sigma Receptor Ligands as Cytotoxic Agents: A Medicinal Chemistry Perspective

Journal of Medicinal Chemistry, 2021

Since their discovery as distinct receptor proteins, the specific physiopathological role of sigma receptors (σRs) has been deeply investigated. It has been reported that these proteins, classified into two subtypes indicated as σ 1 and σ 2 , might play a pivotal role in cancer growth, cell proliferation, and tumor aggressiveness. As a result, the development of selective σR ligands with potential antitumor properties attracted significant attention as an emerging theme in cancer research. This perspective deals with the recent advances of σR ligands as novel cytotoxic agents, covering articles published between 2010 and 2020. An up-to-date description of the medicinal chemistry of selective σ 1 R and σ 2 R ligands with antiproliferative and cytotoxic activities has been provided, including major pharmacophore models and comprehensive structure−activity relationships for each main class of σR ligands.

Study of the Relationship between Sigma Receptor Expression Levels and Some Common Sigma Ligand Activity in Cancer Using Human Cancer Cell Lines of the NCI-60 Cell Line Panel

Biomedicines

Sigma (σ) receptors have attracted great interest since they are implicated in various cellular functions and biological processes and diseases, including various types of cancer. The receptor family consists of two subtypes: sigma-1 (σ1) and sigma-2 (σ2). Both σ receptor subtypes have been proposed as therapeutic targets for various types of cancers, and many studies have provided evidence that their selective ligands (agonists and antagonists) exhibit antiproliferative and cytotoxic activity. Still, the precise mechanism of action of both σ receptors and their ligands remains unclear and needs to be elucidated. In this study, we aimed to simultaneously determine the expression levels of both σ receptor subtypes in several human cancer cell lines. Additionally, we investigated the in vitro antiproliferative activity of some widely used σ1 and σ2 ligands against those cell lines to study the relationship between σ receptor expression levels and σ ligand activity. Finally, we ran the...

Use of Multifunctional Sigma-2 Receptor Ligand Conjugates to Trigger Cancer-Selective Cell Death Signaling

Cancer Research, 2012

One major challenge in the development of cancer therapeutics is the selective delivery of the drugs to their cellular targets. In the case of pancreatic cancer, the σ-2 receptor is a unique target that triggers apoptosis upon activation. We have previously developed a series of chemical compounds with high affinity for the σ-2 receptor and demonstrated rapid internalization of the ligands. One particular specific ligand of the σ-2 receptor, SV119, binds to pancreatic cancer cells and induces target cell death in vitro and in vivo. In this study, we characterized the ability of SV119 to selectively deliver other death-inducing cargos to augment the cytotoxic properties of SV119 itself. When conjugated to SV119, small molecules that are known to interfere with intracellular pro-survival pathways retained their ability to induce cell death, the efficiency of which was enhanced by the combinatorial effect of SV119 delivered with its small molecule cargo.

Design, synthesis, and biological evaluation of sigma receptors (σRS) ligands as potential pharmacotherapy for cancer and drug addiction

2015

Sigma receptors are a well-defined unique class of receptors and are highly expressed in the central nervous system and also widely distributed in peripheral organs and tissues. There are two subtypes of sigma receptors: sigma-1 and sigma-2. These receptors are thought to be associated with functions and disorders such as inflammation, depression, anxiety, Alzheimer’s disease, epilepsy and drug abuse. The sigma-1 receptor has been demonstrated to be involved in acute and chronic effects of cocaine and methamphetamine toxicities. However, the role of sigma-2 receptors is less clear due to the lack of availability of detailed protein structural information and truly selective sigma-2 ligands, which hindered the pharmacological characterization of the sigma-2 subtype. In fact, the sigma-2 receptor has not yet been cloned. Several reports indicated that the activation of sigma-2 receptor also induces growth arrest and cell death in various tumor cell lines. This gives sigma-2 ligands po...

Recent Advances in the Development of Sigma-1 Receptor Ligands

Australian Journal of Chemistry, 2015

The existence of two distinct sigma (s) receptor subtypes was established in the early 1990s. Sigma-1 and sigma-2 receptors (S1Rs and S2Rs, respectively) were shown to possess distinct molecular size, anatomical distribution, and ligand discrimination. S2R is overexpressed in numerous human cancers, and has therapeutic potential for the imaging and treatment of certain tumours. In contrast, S1R is more broadly involved in a wide variety of central nervous system (CNS) diseases including motor disorders, memory deficits, depression, schizophrenia, anxiety, pain, drug addiction, and many more. Since the human S1R was cloned in 1996, numerous high affinity ligands with excellent selectivity for S1R have been developed. This review focuses on recent developments in the generation of structurally diverse S1R-selective ligands and novel therapeutic candidates targeting S1Rs. include medicinal chemistry, heterocyclic chemistry, drug discovery, and structure-activity relationships of molecules with activity in the central nervous system. He serves on several journal editorial boards focussing on medicinal chemistry, pharmaceutical design and drug discovery.

Characterization of Sigma Receptor Mediated Apoptosis in Breast Tumor Cells

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σ2 Receptor and Its Role in Cancer with Focus on a MultiTarget Directed Ligand (MTDL) Approach

Molecules

Sigma-2 (σ2) is an endoplasmic receptor identified as the Endoplasmic Reticulum (ER) transmembrane protein TMEM97. Despite its controversial identity, which was only recently solved, this protein has gained scientific interest because of its role in the proliferative status of cells; many tumor cells from different organs overexpress the σ2 receptor, and many σ2 ligands display cytotoxic actions in (resistant) cancer cells. These properties have shed light on the σ2 receptor as a potential druggable target to be bound/activated for the diagnosis or therapy of tumors. Additionally, diverse groups have shown how the σ2 receptor can be exploited for the targeted delivery of the anticancer drugs to tumors. As the cancer disease is a multifactorial pathology with multiple cell populations, a polypharmacological approach is very often needed. Instead of the simultaneous administration of different classes of drugs, the use of one molecule that interacts with diverse pharmacological target...

An Emerging Role for Sigma Receptor 1 in Personalized Treatment of Breast Cancer

Cancers

Despite the major progress in treating breast cancer, recurrence remains a problem and types such as triple-negative breast cancer still lack targeted medicine. The orphan Sigma receptor1 (SigmaR1) has emerged as a target in breast cancer, but its mechanism of action is unclear and hinders clinical utility. SigmaR1 is widely expressed in organ tissues and localized to various sub-cellular compartments, particularly the endoplasmic reticulum (ER), the mitochondrial-associated membranes (MAMs) and the nuclear envelope. As such, it involves diverse cellular functions, including protein quality control/ER stress, calcium signaling, cholesterol homeostasis, mitochondrial integrity and energy metabolism. Consequently, SigmaR1 has been implicated in a number of cancers and degenerative diseases and thus has been intensively pursued as a therapeutic target. Because SigmaR1 binds a number of structurally unrelated ligands, it presents an excellent context-dependent therapeutic target. Here, ...