Novel acridine-based LSD1 inhibitors enhance immune response in gastric cancer

LSD1 engaged ERα activation orchestrates the formation of migrasomes to promote gastric cancer metastasis

The lysine specific demethylase 1 (LSD1) plays a vital role in promoting various malignancies, while the role of LSD1 in gastric cancer (GC) remains poorly understood. Herein, we show the critical role of LSD1 in GC migration. The overexpression of LSD1 in GC tissues, particularly in those with metastasis, indicates its potential in driving GC migration. Further mechanism study revealed that LSD1, a coregulator of ERα, is involved in the transcriptional regulation of ERα target genes, highlighting the significance of LSD1 and ERα in promoting GC cell migration. We characterized that LSD1 and ERα activation facilitated GC cell migration by promoting the generation of migrasomes mediated by the upregulated fibronectin (FN1). Upon LSD1 abrogation, a substantial decrease in the expression levels of TSPAN4 and NDST1, recognized markers of migrasomes, was observed. Our findings reveal a novel mechanism involving the interaction between LSD1, ERα, FN1 and migrasomes in facilitating GC migration.

Predictive biomarkers in the era of immunotherapy for gastric cancer: current achievements and future perspectives

Gastric cancer (GC) is one of the primary contributors to cancer-related mortality on a global scale. It holds a position within the top five most prevalent malignancies both in terms of occurrence and fatality rates. Immunotherapy, as a breakthrough cancer treatment, brings new hope for GC patients. Various biomarkers, such as the expression of programmed death ligand-1 (PD-L1), the microsatellite instability (MSI) status, tumor mutational burden (TMB), and Epstein-Barr virus (EBV) infection, demonstrate potential to predict the effectiveness of immunotherapy in treating GC. Nevertheless, each biomarker has its own limitations, which leads to a significant portion of patients continue to be unresponsive to immunotherapy. With the understanding of the tumor immune microenvironment (TIME), genome sequencing technology, and recent advances in molecular biology, new molecular markers, such as POLE/POLD1mutations, circulating tumor DNA, intestinal flora, lymphocyte activation gene 3 (LAG-3), and lipid metabolism have emerged. This review aims to consolidate clinical evidence to offer a thorough comprehension of the existing and emerging biomarkers. We discuss the mechanisms, prospects of application, and limitations of each biomarker. We anticipate that this review will open avenues for fresh perspectives in the investigation of GC immunotherapy biomarkers and promote the precise choice of treatment modalities for gastric cancer patients, thereby advancing precision immuno-oncology endeavors.

The Exploration of Indole-Based LSD1-Targeted Inhibitors for Enhanced Immune Response in Gastric Cancer via the PD-L1/PD-1 Axis

Gastric cancer is one of the major health threats to human beings and has a low response rate to emerging immunotherapy. We herein reported a novel indole-based LSD1-targeted antigastric agent 7ae, which was able to enhance the sensitivity of gastric cancer cells to a T-cell-mediated immune response. It exhibited potent LSD1 inhibitory activity (IC50 = 0.080 ± 0.002 μM) and reduced the expression of PD-L1, which in turn promoted the T-cell killing response in gastric cancer cells. As a result, 7ae acted as an active LSD1 inhibitor, exerting excellent anti-invasion and anti-migration effects in gastric cancer cells and leading to significant suppression of the growth of xenograft gastric tumors without obvious toxicity in vivo. Collectively, 7ae has been demonstrated to be a novel, potent LSD1 inhibitor with the potential to be used as an antigastric agent, as well as a useful tool compound for exploratory studies of T-cell-mediated immunity and/or immunotherapy in gastric cancer.

LSD1 is a targetable vulnerability in gastric cancer harboring TP53 frameshift mutations

BACKGROUND

TP53 mutations are linked to aggressive progression and chemoresistance in gastric cancer (GC). Frameshift mutation is the second most common mutation type of TP53. However, the consequences of this mutation type in GC were not well understood, and targeted therapies for cancer patients harboring frameshift mutations were also not established. Histone methylation significantly influences tumorigenesis in TP53-mutated cancers, and related inhibitors are emerging as specific therapeutic strategies.

METHODS AND RESULTS

By treating GC cell lines harboring various TP53 mutation types with a library of histone demethylase inhibitors, we identified that GSK690, a reversible inhibitor of lysine-specific demethylase 1 (LSD1), selectively inhibits GC cells harboring TP53 frameshift mutations without nuclear localization sequence (NLS) (termed TP53 Frameshift NLS), which accounts for 89% TP53 frameshift mutations in GC patients. GSK690 showed significant specific inhibition in vitro and in vivo against this subtype by inducing G1/S cell cycle arrest via the LSD1-CCNA2 axis. Importantly, dual-luciferase assays and ChIP-qPCR confirmed that the loss of transcriptional repression activities of p53 in drives LSD1 upregulation in TP53 Frameshift NLS cancer cells.

CONCLUSIONS

In summary, our results indicate that the nuclear localization deficiency of p53 accounts for increased expression of LSD1 in TP53 Frameshift NLS GCs. GSK690 inhibits cell cycle progression and tumor growth by suppressing aberrantly activated LSD1-CCNA2 signaling in this GC subtype, counteracting malignant proliferation and thereby providing a precise therapeutic strategy for GC patients with TP53 Frameshift NLS.

Exploring the therapeutic potential of acridines: Synthesis, structure, and biological applications

The objective of this review was to explore the trends and chemical characteristics of acridines and their derivatives, analyze their contribution to the scientific literature and international cooperation, identify the most influential authors and articles, and provide an overview of the knowledge produced in elucidating their mechanisms of action. To this end, a bibliometric analysis was performed using RStudio software, along with a systematic review focusing on articles indexed in the "Web of Science" and "Scopus" databases. The keywords used were "acridine$", "Synthesi$", "Structure$", and "Biologic* Application$" for the period from 2020 to 2024. Relevant articles were carefully selected from these databases, and a bibliometric analysis was carried out to comprehensively discuss the most relevant biological activities associated with acridines. The results showed that, during the analyzed period, China and India led in the number of publications, followed by Brazil in third place. However, a decline in the number of publications was observed in the last two years of the period. Keyword analysis revealed that antitumor activity remains the most extensively studied aspect of acridines and their derivatives.

The plasticity of epithelial cells and its potential in the induced differentiation of gastric cancer

Cell plasticity refers to the deviation of cells from normal terminal differentiation states when faced with environmental and genetic toxic stresses, resulting in the phenomenon of transforming into other cell or tissue phenotypes. Unlocking phenotype plasticity has been defined as a hallmark of malignant tumors. The stomach is one of the organs in the body with the highest degree of self-renewal and exhibits significant cell plasticity. In this paper, based on the review of the characteristics of normal differentiation of gastric epithelial cells and their markers, the four main phenotypes of gastric epithelial cell remodeling and their relationship with gastric cancer (GC) are drawn. Furthermore, we summarize the regulatory factors and mechanisms that affect gastric epithelial cell plasticity and outline the current status of research and future prospection for the treatment targeting gastric epithelial cell plasticity. This study has important theoretical reference value for the in-depth exploration of epithelial cell plasticity and the tumor heterogeneity caused by it, as well as for the precise treatment of GC.

Discovery of 2-Aryl-4-aminoquinazolin-Based LSD1 Inhibitors to Activate Immune Response in Gastric Cancer

LSD1 (histone lysine-specific demethylase 1) has been gradually disclosed to act as an immunomodulator to enhance antitumor immune response. Despite the identification of numerous potent LSD1 inhibitors, there remains a lack of LSD1 inhibitors approved for marketing. Novel LSD1 inhibitors with different mechanisms are therefore needed. Herein, we reported a series of novel quinazoline-based LSD1 inhibitors. Among them, compound Z-1 exhibited the best LSD1 inhibitory activity (IC50 = 0.108 μM). Z-1 also acted as a selective and cellular active as an LSD1 inhibitor. Furthermore, Z-1 promoted response of gastric cancer cells to T-cell killing effect by decreasing PD-L1 expression and further attenuated the PD-1/PD-L1 interaction. In vivo, Z-1 exhibited significant suppression effect on the growth of gastric cancer cells without obvious toxicity. Therefore, Z-1 represents a potential novel immunomodulator that targets LSD1, providing a lead compound with new function mechanism for gastric cancer treatment.

LSD1 in drug discovery: From biological function to clinical application

Lysine-specific demethylase 1 (LSD1) is a flavin adenine dinucleotide (FAD) dependent monoamine oxidase (MAO) that erases the mono-, and dimethylation of histone 3 lysine 4 (H3K4), resulting in the suppression of target gene transcriptions. Besides, it can also demethylate some nonhistone substrates to regulate their biological functions. As reported, LSD1 is widely upregulated and plays a key role in several kinds of cancers, pharmacological or genetic ablation of LSD1 in cancer cells suppresses cell aggressiveness by several distinct mechanisms. Therefore, numerous LSD1 inhibitors, including covalent and noncovalent, have been developed and several of them have entered clinical trials. Herein, we systemically reviewed and discussed the biological function of LSD1 in tumors, lymphocytes as well as LSD1-targeting inhibitors in clinical trials, hoping to benefit the field of LSD1 and its inhibitors.