OBJECTIVE: To screen anti-tumor drugs that improve antigen processing and presentation in acute myeloid leukemia (AML) cells. METHODS: A TCR-like or TCR mimic antibody that can specifically recognize HLA-A*0201:WT1_126-134 ( RMFPNAPYL) complex (hereafter referred to as HLA-A2:WT1) was synthesized to evaluate the function of antigen processing and presentation machinery (APM) in AML cells. AML cell line THP1 was incubated with increasing concentrations of IFN-γ, hypomethylating agents (HMA), immunomodulatory drugs (IMiD), proteasome inhibitors (PI) and γ-secretase inhibitors (GSI), followed by measuring of HLA-ABC, HLA-A2 and HLA-A2:WT1 levels by flow cytometry at consecutive time points. RESULTS: The TCR-like antibody we generated only binds to HLA-A*0201⁺WT1⁺ cells, indicating the specificity of the antibody. HLA-A2:WT1 level of THP-1 cells detected with the TCR-like antibody was increased significantly after co-incubation with IFN-γ, showing that the HLA-A2:WT1 TCR like antibody could evaluate the function of APM. Among the anti-tumor agents screened in this study, GSI (LY-411575) and HMA (decitabine and azacitidine) could significantly increase the HLA-A2:WT1 level. The IMiD lenalidomide and pomalidomide could aslo upregulate the expression of HLA-A2:WT1 complex under certain concentrations of the drugs and incubation time. As proteasome inhibitors, carfilzomib could significantly decreased the expression of HLA-A2:WT1, while bortezomib had no significant effect on HLA-A2:WT1 expression. CONCLUSION HLA-A2:WT1 TCR-like antibody can effectively reflect the APM function. Some of the anti-tumor drugs can affect the APM function and immunogenicity of tumor cells.
Humans ; Leukemia, Myeloid, Acute/immunology* ; Antineoplastic Agents/pharmacology* ; Antigen Presentation/drug effects* ; HLA-A2 Antigen/immunology* ; Receptors, Antigen, T-Cell/immunology* ; Cell Line, Tumor ; Interferon-gamma

OBJECTIVE: To investigate the biological activity and antitumor effect of pegylated recombinant human interleukin 2 (PEG-rhIL-2) obtained by site-specific conjugation of polyethylene glycol (PEG) with non-natural amino acids, and to explore its antitumor mechanism. METHODS: The binding activities of PEG-rhIL-2 at three different sites (T41, Y45, and V91) to human interleukin 2 receptors α (IL-2R_α) and β (IL-2R_β) and were detected by surface plasmon resonance (SPR) technology. Western blot was used to detect the levels of the Janus kinase-signal transducer and activator of transcription 5 (JAK-STAT5) signaling pathway activated by different doses of rhIL-2 and PEG-rhIL-2 in CTTL-2 and YT cells. Blood was collected after a single administration in mice to detect the drug concentration at different time points and evaluate the pharmacokinetic parameters of Y45-PEG-rhIL-2. Mouse hepatoma cell line Hepa1-6, pancreatic cancer cell line Pan-02, and colon cancer cell line MC-38 were selected. Tumor models were constructed in C57BL/6 mice. Different doses of Y45-PEG-rhIL-2 and excipient control were administrated respectively to evaluate the tumor suppression effect of the drug. In the MC-38 colon cancer model, the tumor suppression effect of Y45-PEG-rhIL-2 combined with anti-programmed death-1 (PD-1) monoclonal antibody was evaluated. Hepa1-6 mouse tumor models were constructed and rhIL-2, Y45-rhIL-2 and Y45-PEG-rhIL-2 were administrated respectively. The proportion of tumor-infiltrating lymphocytes was analyzed by flow cytometry. RESULTS: The SPR detection results showed that the binding activities of PEG-rhIL-2 to IL-2R_α/IL-2R_β were both reduced. The affinity of Y45-PEG-rhIL-2 to IL-2R_α was reduced to approximately 1/250, and its affinity to IL-2R_β was reduced to 1/3. Western blot results showed that the activity of Y45-PEG-rhIL-2 in stimulating JAK-STAT5 signaling in CTLL-2 cells expressing heterotrimeric IL-2 receptor complex IL-2R_αβγwas reduced to approximately 1/300, while its activity in YT cells expressing heterodimeric IL-2 receptor complex IL-2R_βγwas reduced to approximately 1/3. The pharmacokinetic evaluation after a single dose in the mice showed that the elimination half-life of Y45-PEG-rhIL-2 was 17.7 h. Y45-PEG-rhIL-2 has pharmacokinetic characteristics superior to those of rhIL-2. Y45-PEG-rhIL-2 showed dose-dependent tumor suppression activity, and the combination of Y45-PEG-rhIL-2 and anti-PD-1 antibody had a better tumor-inhibiting effect than the single use of Y45-PEG-rhIL-2 or anti-PD-1 antibody. Flow cytometry analysis demonstrated that 72 h after the administration of Y45-PEG-rhIL-2, the proportion of tumor-infiltrating cytotoxic T lymphocytes (CD8⁺T cells) increased by 86.84%. At 120 h after administration, the ratio of CD8⁺T cells to regulatory T cells (Treg) increased by 75.10%. CONCLUSION Y45-PEG-rhIL-2 obtained by site-specific conjugation via non-natural amino acids changed its receptor binding activity and inhibited tumor growth in dose-dependent manner in multiple tumor models by regulating CD8⁺T cells.
Interleukin-2/pharmacokinetics* ; Animals ; Mice ; Humans ; Recombinant Proteins/pharmacology* ; Polyethylene Glycols/chemistry* ; Cell Line, Tumor ; Antineoplastic Agents/pharmacokinetics* ; Signal Transduction/drug effects* ; STAT5 Transcription Factor/metabolism* ; Interleukin-2 Receptor alpha Subunit/metabolism* ; Interleukin-2 Receptor beta Subunit/metabolism*

The inhibition of cyclin-dependent kinases (CDKs) is considered a promising strategy for cancer treatment due to their role in cell cycle regulation. However, CDK inhibitors with no selectivity among CDK families have not been approved. A CDK inhibitor with high selectivity for CDK4/6 exhibited significant treatment effects on breast cancer and has become a heavy bomb on the market. Subsequently, resistance gradually decreased the efficacy of selective CDK4/6 inhibitors in breast cancer treatment. In this review, we first introduce the development of selective CDK4/6 inhibitors and then explain the role of CDK2 activation in inducing resistance to CDK4/6 inhibitors. Moreover, we focused on the development of CDK2/4/6 inhibitors and selective CDK2 inhibitors, which will aid in the discovery of novel CDK inhibitors targeting the cell cycle in the future.
Humans ; Cell Cycle/drug effects* ; Protein Kinase Inhibitors/chemistry* ; Cyclin-Dependent Kinases/metabolism* ; Neoplasms/genetics* ; Antineoplastic Agents/pharmacology* ; Animals ; Breast Neoplasms/enzymology* ; Cyclin-Dependent Kinase 4/metabolism*

Cancer represents a significant disease that profoundly impacts human health and longevity. Projections indicate a 47% increase in the global cancer burden by 2040 compared to 2020, accompanied by a further rise in the associated economic burden. Consequently, there is an urgent need to discover and develop new alternative drugs to mitigate the global impact of cancer. Natural products (NPs) play a crucial role in the identification and development of anticancer therapeutics. This study identified ustusolate E (UE) and its analog 11α-hydroxy-ustusolate E (HUE) from strain Aspergilluscalidoustus TJ403-EL05, and examined their antitumor activities and mechanisms of action. The findings demonstrate that both compounds significantly inhibited the proliferation and colony formation of AGS (human gastric cancer cells) and 786-O (human renal clear cell carcinoma cells), induced irreversible DNA damage, blocked the cell cycle at the G₂/M phase, and further induced apoptosis in tumor cells. To the best of the authors' knowledge, this is the first report on the anticancer effects of UE and HUE and their underlying mechanisms. The present study suggests that HUE and UE could serve as lead compounds for the development of novel anticancer drugs.
Humans ; Apoptosis/drug effects* ; TOR Serine-Threonine Kinases/genetics* ; Proto-Oncogene Proteins c-akt/genetics* ; Cell Line, Tumor ; Phosphatidylinositol 3-Kinases/genetics* ; Signal Transduction/drug effects* ; Tumor Suppressor Protein p53/genetics* ; Cell Proliferation/drug effects* ; Antineoplastic Agents/pharmacology* ; Sesquiterpenes/pharmacology* ; Aspergillus/chemistry*

Five novel nor-eremophilane-type sesquiterpenoids, peniroqueforins E-H and J (1-4 and 7), two new eremophilane-type sesquiterpenoids, peniroqueforins I and K (5 and 8), and a new eudesmane-type sesquiterpenoid, peniroqueforin L (9), along with four known compounds (6 and 10-12), were isolated and characterized from fungus Penicillium roqueforti (P. roqueforti). The structures and absolute configurations of these compounds were determined through comprehensive spectroscopic analyses, electronic circular dichroism (ECD) data analyses, and single-crystal X-ray diffraction methods. The anti-multi-drug resistance (MDR) cancer activity of these compounds was evaluated using SW620/Ad300 cells. Notably, the half maximal inhibitory concentration (IC₅₀) value of paclitaxel (PTX) combined with 1 in SW620/Ad300 cells was 50.36 nmol·L^-1, which was 65-fold more potent than PTX alone (IC₅₀ 3.26 μmol·L^-1). Subsequent molecular docking studies revealed an affinity between compound 1 and P-glycoprotein (P-gp), suggesting that this nor-eremophilane-type sesquiterpenoid (1) could serve as a potential lead for MDR reversal in cancer cells through P-gp inhibition.
Penicillium/chemistry* ; Humans ; Sesquiterpenes/isolation & purification* ; Cell Line, Tumor ; Molecular Structure ; Drug Resistance, Neoplasm/drug effects* ; Antineoplastic Agents/pharmacology* ; Drug Resistance, Multiple/drug effects* ; Molecular Docking Simulation

Five new flavan-4-ol glycosides jixueqiosides A-E (1-5) and two new flavan glycosides jixueqiosides F and G (6 and 7), along with twelve known flavan-4-ol glycosides (8-19), were isolated from the roots of Pronephrium penangianum. Comprehensive spectral analyses, X-ray single-crystal diffraction, and theoretical electronic circular dichroism (ECD) calculations established structures and absolute configurations. A single crystal structure of flavan-4-ol glycoside (14) was reported for the first time, while the characteristic ECD and NMR data for all isolated flavan-4-ol glycosides (1-5 , 8-19) were analyzed, establishing a set of empirical rules. Activity screening of these isolates showed that 8 and 9 could inhibit the proliferation of MDA-MB-231 and MCF-7 cells with IC₅₀ values of 7.93 ? 2.85 ?mol?L^-1 and 5.87 ? 1.58 ?mol?L^-1 (MDA-MB-231), and 2.21 ? 1.38 ?mol?L^-1 and 3.52 ? 1.55 ?mol?L^-1 (MCF-7), respectively. Western blotting and flow cytometry analyses demonstrated that 8 and 9 dose-dependently induced apoptosis in MDA-MB-231 cells by up-regulating BAX, activating caspase-3 and down-regulating BCL-2. Additionally, compound 8 affected autophagy-related proteins, increasing the ratio of LC3-II/LC3-I and Beclin-1 levels to inhibit MDA-MB-231 cell proliferation. Moreover, anti-inflammatory studies indicated that 2, 3, 7, 13, 14, and 18 moderately inhibited tumor necrosis factor-a (TNF-a), interleukin-6 (IL-6), and nitric oxide (NO) release.
Humans ; Plant Roots/chemistry* ; Glycosides/isolation & purification* ; Anti-Inflammatory Agents/isolation & purification* ; Flavonoids/isolation & purification* ; Cell Proliferation/drug effects* ; Antineoplastic Agents, Phytogenic/isolation & purification* ; Molecular Structure ; Apoptosis/drug effects* ; Cell Line, Tumor ; Tumor Necrosis Factor-alpha/immunology* ; Drugs, Chinese Herbal/pharmacology* ; Interleukin-6/immunology* ; Animals ; Mice

A comprehensive phytochemical investigation of the leaves and twigs of Physalis angulata. var. villosa resulted in the isolation of 23 withanolide derivatives, including one novel 13,20-γ-lactone withanolide derivative (1) and three new withanolide derivatives (2-4). Architecturally, physalinin A (1) represents the first identified type B withanolide featuring a 13,20-γ-lactone moiety. The molecular structures of all isolates were elucidated using an integrated approach combining nuclear magnetic resonance (NMR) spectroscopy, mass spectrometry (MS), infrared (IR) spectroscopy, and quantum chemical calculations to confirm structural assignments. The antiproliferative activities of all isolated withanolides were evaluated against four human cancer cell lines (HEL, HCT-116, Colo320DM, and MDA-MB-231). Among them, eight derivatives (2, 5-8, 14, 15, and 23) exhibited significant inhibitory effects, with half-maximal inhibitory concentration (IC₅₀) values of 0.18 ± 0.03 to 17.02 ± 0.21 μmol·L^-1. Structure-activity relationship (SAR) analysis suggested that the presence of an epoxide ring enhances anticancer activity, potentially through increased reactivity or specific interactions with molecular targets involved in cancer progression. These findings underscore the pharmacological potential of withanolides as promising lead compounds for the development of novel anticancer therapeutics.
Withanolides/isolation & purification* ; Physalis/chemistry* ; Humans ; Molecular Structure ; Cell Line, Tumor ; Antineoplastic Agents, Phytogenic/isolation & purification* ; Cell Proliferation/drug effects* ; Plant Leaves/chemistry* ; Plant Extracts/pharmacology*

Paclitaxel (PTX), a valuable natural product derived from Taxus species, exhibits remarkable anti-cancer properties. It penetrates nanopores in microtubule walls, interacting with tubulin on the lumen surface and disrupting microtubule dynamics, thereby inducing cytotoxic effects in cancer cells. PTX and its derivatives have gained approval for treating various diseases due to their low toxicity, high efficiency, and broad-spectrum application. The widespread success and expanding applications of PTX have led to increased demand, raising concerns about accessibility. Consequently, researchers globally have focused on developing alternative production methods and applying nanocarriers in PTX delivery systems to enhance bioavailability. This review examines the challenges and advancements in PTX sourcing, production, physicochemical properties, anti-cancer mechanisms, clinical applications, trials, and chemo-immunotherapy. It aims to provide a comprehensive reference for the rational development and effective utilization of PTX.
Humans ; Paclitaxel/pharmacology* ; Antineoplastic Agents, Phytogenic/pharmacology* ; Neoplasms/drug therapy* ; Animals ; Taxus/chemistry*

Triple-negative breast cancer (TNBC) represents an aggressive breast cancer subtype with poor prognosis and limited targeted treatment options. This investigation examined the anti-cancer potential of Caerulomycin A (Cae A), a natural compound derived from marine actinomycetes, against TNBC. Cae A demonstrated selective inhibition of viability and proliferation in TNBC cell lines, including 4T1, MDA-MB-231, and MDA-MB-468, through apoptosis induction. Mechanistic analyses revealed that the compound induced sustained endoplasmic reticulum (ER) stress and subsequent upregulation of C/EBP homologous protein (CHOP) expression, resulting in mitochondrial damage-mediated apoptosis. Inhibition of ER stress or CHOP expression knockdown reversed mitochondrial damage and apoptosis, highlighting the essential role of ER stress and CHOP in Cae A's anti-tumor mechanism. Both oxygen consumption rate (OCR) and extracellular acidification rate (ECAR) decreased in TNBC cells following Cae A treatment, indicating reduced mitochondrial respiratory and glycolytic capacities. This diminished energy metabolism potentially triggers ER stress and subsequent apoptosis. Furthermore, Cae A exhibited significant anti-tumor effects in the 4T1 tumor model in vivo without apparent toxicity. The compound also effectively inhibited human TNBC organoid growth. These results indicate that Cae A may serve as a potential therapeutic agent for TNBC, with its efficacy likely mediated through the disruption of glucose metabolism and the induction of ER stress-associated apoptosis.
Humans ; Endoplasmic Reticulum Stress/drug effects* ; Triple Negative Breast Neoplasms/genetics* ; Apoptosis/drug effects* ; Cell Line, Tumor ; Female ; Animals ; Glucose/metabolism* ; Mice ; Cell Proliferation/drug effects* ; Transcription Factor CHOP/genetics* ; Antineoplastic Agents/pharmacology* ; Mitochondria/metabolism* ; Mice, Inbred BALB C

Gastric cancer (GC) is characterized by high morbidity and mortality rates. Chinese agarwood comprises the resin-containing wood of Aquilaria sinensis (Lour.) Gilg., traditionally utilized for treating asthma, cardiac ischemia, and tumors. However, comprehensive research regarding its anti-GC effects and underlying mechanisms remains limited. In this study, Chinese agarwood petroleum ether extract (CAPEE) demonstrated potent cytotoxicity against human GC cells, with half maximal inhibitory concentration (IC₅₀) values for AGS, HGC27, and MGC803 cells of 2.89, 2.46, and 2.37 μg·mL^-1, respectively, at 48 h. CAPEE significantly induced apoptosis in these GC cells, with B-cell lymphoma-2 (BCL-2) associated X protein (BAX)/BCL-2 antagonist killer 1 (BAK) likely mediating CAPEE-induced apoptosis. Furthermore, CAPEE induced G₀/G₁ phase cell cycle arrest in human GC cells via activation of the deoxyribonucleic acid (DNA) damage-p21-cyclin D1/cyclin-dependent kinase 4 (CDK4) signaling axis, and increased Fe²⁺, lipid peroxides and reactive oxygen species (ROS) levels, thereby inducing ferroptosis. Ribonucleic acid (RNA) sequencing, real-time quantitative polymerase chain reaction (RT-qPCR), and Western blotting analyses revealed CAPEE-mediated upregulation of heme oxygenase-1 (HO-1) in human GC cells. RNA interference studies demonstrated that HO-1 knockdown reduced CAPEE sensitivity and inhibited CAPEE-induced ferroptosis in human GC cells. Additionally, CAPEE administration exhibited robust in vivo anti-GC activity without significant toxicity in nude mice while inhibiting tumor cell growth and promoting apoptosis in tumor tissues. These findings indicate that CAPEE suppresses human GC cell growth through upregulation of the DNA damage-p21-cyclin D1/CDK4 signaling axis and HO-1-mediated ferroptosis, suggesting its potential as a candidate drug for GC treatment.
Animals ; Humans ; Mice ; Antineoplastic Agents, Phytogenic ; Apoptosis/drug effects* ; Cell Line, Tumor ; Cyclin D1/genetics* ; Cyclin-Dependent Kinase 4/genetics* ; DNA Damage/drug effects* ; Drugs, Chinese Herbal/pharmacology* ; Ferroptosis/drug effects* ; G1 Phase Cell Cycle Checkpoints/drug effects* ; Heme Oxygenase-1/genetics* ; Mice, Inbred BALB C ; Mice, Nude ; Plant Extracts/pharmacology* ; Stomach Neoplasms/physiopathology* ; Thymelaeaceae/chemistry* ; Up-Regulation/drug effects*