Gene expression changes contribute to stemness and therapy resistance of relapsed acute myeloid leukemia: roles of SOCS2, CALCRL, MTSS1, and KDM6A

CALCRL knockdown suppresses cancer stemness and chemoresistance in acute myeloid leukemia with FLT3-ITD and DNM3TA-R882 double mutations

Acute myeloid leukemia (AML) patients with FLT3 internal tandem duplication (FLT3-ITD) and DNA methyltransferase 3A (DNMT3A) R882 double mutations had a worse prognosis compared with AML with FLT3-ITD or DNMT3A R882 single mutation. This study was designed to explore the specific role of Calcitonin Receptor Like (CALCRL) in AML with FLT3-ITD and DNMT3A R882 double mutations. MOLM13 cells were transduced with CRISPR knockout sgRNA constructs to establish the FTL3-ITD and DNMT3A-R882 double-mutated AML cell model. Quantitative real-time PCR and Western blot assay were carried out to examine corresponding gene and protein expression. Methylation of CALCRL promoter was measured by methylation-specific PCR (MSP). Cell viability, colony formation, flow cytometry, and sphere formation assays were conducted to determine cell proliferation, apoptosis, and stemness. MOLM13 cells were exposed to stepwise increasing concentrations of cytarabine (Ara-C) to generate MOLM13/Ara-C cells. An in vivo AML  animal model was established, and the tumor volume and weight were recorded. TUNEL assay was adopted to examine cell apoptosis in tumor tissues. DNMT3A-R882 mutation upregulated the expression of CALCRL while downregulated the DNA methylation level of CALCRL in MOLM13 cells. CALCRL knockdown greatly inhibited cell proliferation, promoted apoptosis and repressed cell stemness, accompanied with the downregulated Oct4, SOX2, and Nanog in DNMT3A-R882-mutated MOLM13 cells and MOLM13/Ara-C cells. Furthermore, CALCRL knockdown restricted tumor growth and the chemoresistance of AML in vivo, as well as inducing cell apoptosis in tumor tissues. Together, these data reveal that CALCRL is a vital regulator of leukemia cell survival and resistance to chemotherapy, suggesting CALCRL as a promising therapeutic target for the treatment of FTL3-ITD and DNMT3A-R882 double-mutated AML.

Prognostic value of MTSS1 gene expression on acute leukemia patients outcome

Background: This study aimed to evaluate the prognostic value of the MTSS1 gene expression in patients with acute leukemia. Patients & methods: MTSS1 gene expression was quantified in 120 newly diagnosed acute leukemia patients, by quantitative reverse transcription PCR at diagnosis and after induction chemotherapy therapy. Results: Baseline MTSS1 gene expression was significantly higher in acute leukemia patients compared to the control group (p < 0.001). Acute leukemia patients with low baseline MTSS1 gene expression at diagnosis have significantly shorter overall survival and disease-free survival compared with those with higher expression (p < 0.001 for both). Conclusion: Downregulation of MTSS1 gene expression at diagnosis was associated with poor outcome in either cytogenetic acute myeloid leukemia or B-cell acute lymphoblastic leukemia.

Elucidating the Interactome of G Protein-Coupled Receptors and Receptor Activity-Modifying Proteins

G protein-coupled receptors (GPCRs) are known to interact with several other classes of integral membrane proteins that modulate their biology and pharmacology. However, the extent of these interactions and the mechanisms of their effects are not well understood. For example, one class of GPCR-interacting proteins, receptor activity-modifying proteins (RAMPs), comprise three related and ubiquitously expressed single-transmembrane span proteins. The RAMP family was discovered more than two decades ago, and since then GPCR-RAMP interactions and their functional consequences on receptor trafficking and ligand selectivity have been documented for several secretin (class B) GPCRs, most notably the calcitonin receptor-like receptor. Recent bioinformatics and multiplexed experimental studies suggest that GPCR-RAMP interactions might be much more widespread than previously anticipated. Recently, cryo-electron microscopy has provided high-resolution structures of GPCR-RAMP-ligand complexes, and drugs have been developed that target GPCR-RAMP complexes. In this review, we provide a summary of recent advances in techniques that allow the discovery of GPCR-RAMP interactions and their functional consequences and highlight prospects for future advances. We also provide an up-to-date list of reported GPCR-RAMP interactions based on a review of the current literature. SIGNIFICANCE STATEMENT: Receptor activity-modifying proteins (RAMPs) have emerged as modulators of many aspects of G protein-coupled receptor (GPCR)biology and pharmacology. The application of new methodologies to study membrane protein-protein interactions suggests that RAMPs interact with many more GPCRs than had been previously known. These findings, especially when combined with structural studies of membrane protein complexes, have significant implications for advancing GPCR-targeted drug discovery and the understanding of GPCR pharmacology, biology, and regulation.

Ferroptosis-Driven Nanotherapeutics to Reverse Drug Resistance in Tumor Microenvironment

Ferroptosis, characterized by iron-dependent lipid reactive oxygen species (ROS) accumulation, is non-apoptotic programmed cell death highly relevant to tumor development. It was found to manipulate oncogenes and resistant mutations of cancer cells via lipid metabolism pathways converging on phospholipid glutathione peroxidase (GPX4) that squanders lipid peroxides (L-OOH) to block the iron-mediated reactions of peroxides, thus rendering resistant cancer cells vulnerable to ferroptotic cell death. By accumulating ROS and lipid peroxidation (LPO) products to lethal levels in tumor microenvironment (TME), ferroptosis-driven nanotherapeutics show a superior ability of eradicating aggressive malignancies than traditional therapeutic modalities, especially for the drug-resistant tumors with high metastasis tendency. Moreover, Fenton reaction, inhibition of GPX-4, and exogenous regulation of LPO are three major therapeutic strategies to induce ferroptosis in cancer cells, which were generally applied in ferroptosis-driven nanotherapeutics. In this review, we elaborate current trends of ferroptosis-driven nanotherapeutics to reverse drug resistance of tumors in anticancer fields at the intersection of cancer biology, materials science, and chemistry. Finally, their challenges and perspectives toward feasible translational studies are spotlighted, which would ignite the hope of anti-resistant cancer treatment.

CALCRL Gene is a Suitable Prognostic Factor in AML/ETO+ AML Patients

Introduction

The t(8 ; 21) translocation is the most common chromosomal abnormality in human acute myeloid leukemia (AML) subtype 2 (M2), which forms the AML/ETO fusion gene. However, AML/ETO alone does not necessarily cause leukemia. Other factors are thought to contribute to the disease. Calcitonin receptor-like (CALCRL), a G-protein-coupled neuropeptide receptor, is involved in various biological processes, such as colony formation and drug resistance.

Methods

First, The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) databases were used to determine any differences in CALCRL expression in AML patients with and without AML/ETO and the prognostic significance of CALCRL expression in AML patients was further evaluated. Next, we detected the CALCRL expression level in 67 AML/ETO⁺ AML patients and 16 patients with nonmalignant hematological diseases using qRT-PCR and identified its prognostic relevance.

Results

Individuals in the group expressing low levels of CALCRL had a longer median survival time. In AML/ETO⁺ AML patients, higher mRNA levels of CALCRL were observed before treatment, which decreased after the complete remission that followed multiple chemotherapy sessions. Clinical features indicated that more patients in the CALCRL^high group also had c-kit mutations compared with patients in other groups. Overall survival (OS) was longer in patients with lower levels of CALCRL expression, especially in patients with c-kit mutations or with more blast cells in bone marrow (BM). In addition, a longer OS was observed in the CALCRL^low group after hematopoietic stem cell transplantation (HSCT).

Conclusions

This preliminary study indicates that CALCRL could serve as a suitable prognostic factor in AML/ETO⁺ AML patients.

Integrated Analysis of Stemness-Related LncRNAs Helps Predict the Immunotherapy Responsiveness of Gastric Cancer Patients

The immune microenvironment plays a critical role in tumor biology. As a critical feature of cancers, stemness is acknowledged as a contributor to the development of drug resistance in gastric cancers (GCs). Long non-coding RNAs (lncRNAs) have been revealed to participate in this process. In this study, we aimed to develop a stemness-related lncRNA signature (SRLncSig) with guiding significance for immunotherapy. Three cohorts (TCGA, Zhongshan, and IMvigor210) were enrolled for analysis. A list of stemness-related lncRNAs (SRlncRNAs) was collected by co-expression strategy under the threshold of coefficient value >0.35 and p-value < 0.05. Cox and Lasso regression analysis was further applied to find out the SRlncRNAs with prognosis-predictive value to establish the SRLncSig in the TCGA cohort. IPS and TIDE algorithms were further applied to predict the efficacy of SRLncSig in TCGA and Zhongshan cohorts. IMvigor210 was composed of patients with clinical outcomes of immunotherapy. The results indicated that SRLncSig not only was confirmed as an independent risk factor for GCs but also identified as a robust indicator for immunotherapy. The patient with a lower SRLncSig score was more likely to benefit from immunotherapy, and the results were highly consistent in three cohorts. In conclusion, our study not only could clarify the correlations between stemness and immunotherapy in GC patients but also provided a model to guide the applications of immunotherapy in clinical practice.