Quinacrine-CASIN combination overcomes chemoresistance in human acute lymphoid leukemia

SSRP1/SLC3A2 Axis in Arginine Transport: A New Target for Overcoming Immune Evasion and Tumor Progression in Peripheral T-Cell Lymphoma

Peripheral T-cell lymphoma (PTCL) is a heterogeneous group of mature T-cell malignancies with poor prognosis. Therefore, improved therapies are urgently required to improve patient outcomes. In this study, metabolic inhibitor drug screening reveals that quinacrine elicits excellent antitumor activity both in vitro and in vivo by downregulating intracellular arginine levels in PTCL. Single-cell transcriptomic analyses reveal aberrant arginine metabolism in patients with PTCL, characterized by excessive solute carrier family 3 member 2 (SLC3A2) mediated arginine uptake preferentially in tumor cells. High SLC3A2 expression predicts poor outcomes in PTCL, as SLC3A2-mediated arginine uptake promotes the malignant behaviors of tumor cells and induces tumor immune escape, thereby fueling tumor progression. Mechanistically, high arginine levels induce global metabolic changes, including enhanced oxidative phosphorylation by promoting nascent RNA synthesis. This work identifies structure-specific recognition protein 1 (SSRP1), which upregulates SLC3A2, as a co-transcription factor with JUNB. Quinacrine disrupts SLC3A2-mediated arginine transport by targeting SSRP1. Combining quinacrine with histone deacetylase inhibitors is a promising therapeutic strategy for PTCL.

CASIN exerts anti-aging effects through RPL4 on the skin of naturally aging mice

Skin aging has been associated with the onset of various skin issues, and recent studies have identified an increase in Cdc42 activity in naturally aging mice. While previous literature has suggested that CASIN, a specific inhibitor of Cdc42 activity, may possess anti-aging properties, its specific effects on the epidermis and dermis, as well as the underlying mechanisms in naturally aging mice, remain unclear. Our study revealed that CASIN demonstrated the ability to increase epidermal and dermal thickness, enhance dermal-epidermal junction, and stimulate collagen and elastic fiber synthesis in 9-, 15-, and 24-month-old C57BL/6 mice in vivo. Moreover, CASIN was found to enhance the proliferation, differentiation, and colony formation and restore the cytoskeletal morphology of primary keratinocytes in naturally aging skin in vitro. Furthermore, the anti-aging properties of CASIN on primary fibroblasts in aging mice were mediated by the ribosomal protein RPL4 using proteomic sequencing, influencing collagen synthesis and cytoskeletal morphology both in vitro and in vivo. Meanwhile, both subcutaneous injection and topical application exhibited anti-aging effects for a duration of 21 days. Additionally, CASIN exhibited anti-inflammatory properties, while reduced expression of RPL4 was associated with increased inflammation in the skin of naturally aging mice. Taken together, our results unveil a novel function of RPL4 in skin aging, providing a foundational basis for future investigations into ribosomal proteins. And CASIN shows promise as a potential anti-aging agent for naturally aging mouse skin, suggesting potential applications in the field.

Integrated drug profiling and CRISPR screening identify BCR::ABL1-independent vulnerabilities in chronic myeloid leukemia

BCR::ABL1-independent pathways contribute to primary resistance to tyrosine kinase inhibitor (TKI) treatment in chronic myeloid leukemia (CML) and play a role in leukemic stem cell persistence. Here, we perform ex vivo drug screening of CML CD34+ leukemic stem/progenitor cells using 100 single drugs and TKI-drug combinations and identify sensitivities to Wee1, MDM2, and BCL2 inhibitors. These agents effectively inhibit primitive CD34+CD38- CML cells and demonstrate potent synergies when combined with TKIs. Flow-cytometry-based drug screening identifies mepacrine to induce differentiation of CD34+CD38- cells. We employ genome-wide CRISPR-Cas9 screening for six drugs, and mediator complex, apoptosis, and erythroid-lineage-related genes are identified as key resistance hits for TKIs, whereas the Wee1 inhibitor AZD1775 and mepacrine exhibit distinct resistance profiles. KCTD5, a consistent TKI-resistance-conferring gene, is found to mediate TKI-induced BCR::ABL1 ubiquitination. In summary, we delineate potential mechanisms for primary TKI resistance and non-BCR::ABL1-targeting drugs, offering insights for optimizing CML treatment.

Quinacrine, a PLA2 inhibitor, alleviates LPS-induced acute kidney injury in rats: Involvement of TLR4/NF-κB/TNF α-mediated signaling

Acute Kidney Injury (AKI) is a major factor in sepsis-related mortality and may occur due to lipopolysaccharide (LPS), an endotoxin produced by gram-negative bacteria that triggers a systemic acute inflammatory response. Quinacrine's (QC) renoprotective properties in sepsis and the underlying mechanism, however, are still not fully understood. This study was done to investigate the anti-inflammatory, antioxidative, and anti-apoptotic effects of QC, a phospholipase A2 (PLA2) inhibitor, against LPS-induced AKI. Rats were randomly divided into five groups: control group, QC30 group, LPS group, LPS+QC 10 group, and LPS+QC 30 group. The rats were administered intraperitoneally QC (10 and 30 mg/kg) for 3 days (once a day) prior to injection of LPS (3 mg/kg). Six hours after the LPS injection, the histopathological changes, oxidative stress, inflammation, and apoptosis in the collected kidney tissues were detected by hematoxylin and eosin staining, enzyme-linked immunosorbent assay (ELISA), real-time PCR (RT-PCR), and immunohistochemistry staining, respectively. QC pretreatment could successfully attenuate LPS-induced AKI, as evidenced by a decrease in tissue histopathological injury. Meanwhile, QC alleviated LPS-induced kidney oxidative stress; it reduced MDA levels and increased levels of SOD, CAT, GPX, and GSH. LPS-induced elevations in kidney TLR4, NF-κB, TNF-α, IL-1β, IL-6, PLA2, caspase 3, and Bax contents were significantly attenuated in QC-treated groups. Our findings revealed a significant effect of QC: protecting against LPS-induced AKI through inhibition of PLA2 and decreasing inflammation, oxidative stress, and apoptosis. To treat LPS-induced AKI, QC may be an effective substance with an excellent protection profile.

Chemotherapeutic Activity of Pitavastatin in Vincristine Resistant B-Cell Acute Lymphoblastic Leukemia

B-cell acute lymphoblastic leukemia (ALL) is derived from an accumulation of malignant, immature B cells in the bone marrow and blood. Relapse due, in part, to the emergence of tumor cells that are resistant to front line standard chemotherapy is associated with poor patient outcomes. This challenge highlights the need for new treatment strategies to eliminate residual chemoresistant tumor cells. Based on the use of pitavastatin in acute myeloid leukemia (AML), we evaluated its efficacy in an REH ALL cell line derived to be resistant to vincristine. We found that pitavastatin inhibited the proliferation of both parental and vincristine-resistant REH tumor cells at an IC50 of 449 nM and 217 nM, respectively. Mitochondrial bioenergetic assays demonstrated that neither vincristine resistance nor pitavastatin treatment affected cellular oxidative phosphorylation, beta-oxidation, or glycolytic metabolism in ALL cells. In a co-culture model of ALL cells with bone marrow stromal cells, pitavastatin significantly decreased cell viability more robustly in the vincristine-resistant ALL cells compared with their parental controls. Subsequently, NSG mice were used to develop an in vivo model of B-cell ALL using both parental and vincristine-resistant ALL cells. Pitavastatin (10 mg/kg i.p.) significantly reduced the number of human CD45+ REH ALL cells in the bone marrow of mice after 4 weeks of treatment. Mechanistic studies showed that pitavastatin treatment in the vincristine-resistant cells led to apoptosis, with increased levels of cleaved PARP and protein-signaling changes for AMP-activated protein kinase/FoxO3a/Puma. Our data suggest the possible repurposing of pitavastatin as a chemotherapeutic agent in a model of vincristine-resistant B-cell ALL.

The role of E3 ubiquitin ligase WWP2 and the regulation of PARP1 by ubiquitinated degradation in acute lymphoblastic leukemia

Acute lymphoblastic leukemia (ALL) has been a huge threat for people's health and finding effective target therapy is urgent and important. WWP2, as one of E3 ubiquitin ligase, is involved in many biological processes by specifically binding to substrates. PARP1 plays a role in cell apoptosis and is considered as a therapeutic target of certain cancers. In this study, we firstly found that WWP2 expressed higher in newly diagnosed ALL patients comparing with complete remission (CR) ALL patients and normal control people, and WWP2 in relapse ALL patients expressed higher than normal control people. WWP2 expression was related with the FAB subtype of ALL and the proportion of blast cells in bone marrow blood tested by flow cytometry. We demonstrated knockout WWP2 inhibited the ALL growth and enhanced apoptosis induced by Dox in vitro and vivo for the first time. WWP2 negatively regulated and interacted with PARP1 and WWP2 mechanically degraded PARP1 through polyubiquitin-proteasome pathway in ALL. These findings suggested WWP2 played a role in ALL development as well as growth and apoptosis, and also displayed a regulatory pathway of PARP1, which provided a new potential therapeutic target for the treatment of ALL.

Repurposing of Anti-Malarial Drug Quinacrine for Cancer Treatment: A Review

Quinacrine (QC), a synthetic drug belonging to the 9-aminoacridine family, has been used extensively to treat malaria and multiple ailments over the past several decades. Following its discovery in the 1920s and extensive use for the treatment of malaria for nearly two decades, numerous studies have explored its antineoplastic potential in both preclinical and clinical settings. Multiple studies spanning over seven decades have examined a wide range of QC anticancer activities across various types of cancers, along with the underlying mechanisms. Many of these mechanisms, including activation of the p53 signaling cascade and simultaneous NF-κB signaling inhibition, have been reported in various studies, bringing QC to a unique polypharmacological category drug possessing the potential to treat a wide variety of diseases, including cancer. This article summarizes most of the research conducted over several decades to uncover new molecular mechanisms activated or inactivated and directly correlate with antineoplastic activity QC.