First-line Chemotherapeutic Agent Research Articles

GPR68 supports AML cells through the calcium/calcineurin pro-survival pathway and confers chemoresistance by mediating glucose metabolic symbiosis

Accumulating evidence demonstrates that the “Warburg effect” that glycolysis is enhanced even in the presence of oxygen existed in hematopoietic malignancies, contributing to extracellular acidosis. G-protein coupled receptor 68 (GPR68), as a proton sensing GPCR responding to extracellular acidosis, is expected to play a critical role in hematopoietic malignancies. In the present study, we found that GPR68 was overexpressed in acute myeloid leukemia (AML) cells, and GPR68 deficiency impaired AML cell survival in vitro and cell engraftment in vivo. Mechanistic studies revealed that unlike GPR68 regulates Calpain1 in myelodysplastic syndromes (MDS) cells, GPR68 deficiency reduced cytosolic Ca2+ levels and calcineurin (CaN) activity in AML cells through an NFAT-independent mechanism. Moreover, the decreased Ca2+ levels disturbed cellular respiration (i.e., oxidative phosphorylation, OxPhos) by inhibiting isocitrate dehydrogenase (IDH) activity; this was more pronounced when BCL2 was inhibited simultaneously. Interestingly, GPR68 inhibition also decreased aerobic glycolysis in AML cells in a Ca2+-independent manner, suggesting that GPR68 mediated glucose metabolic symbiosis. As glucose metabolic symbiosis and the heterogeneous dependencies on aerobic glycolysis and cellular respiration tremendously impact chemosensitivity, the inhibition of GPR68 potentiated the tumoricidal effect of first-line chemotherapeutic agents, including BCL-2 inhibitors targeting OxPhos and cytarabine (AraC) targeting glycolysis. Consistent with these in vitro observations, higher levels of GPR68 were associated with inferior clinical outcomes in AML patients who received chemotherapies. In short, GPR68 drives the Ca2+/CaN pro-survival pathway and mediates glucose metabolic pathways in AML cells. Targeting GPR68 eradicates AML cells and alleviates chemoresistance, which could be exploited as a therapeutic target.The overexpression of GPR68 drives a Ca2+/CaN pro-survival pathway and mediates glucose metabolic symbiosis in AML cells, suggesting the diagnostic and therapeutic potential of GPR68 in AML. (GPR68, G proton-coupled receptor 68; PLCβ, phospholipase C beta; CaN, Calcineurin; IDH, isocitrate dehydrogenase; HIF-1α, Hypoxia-inducible factor alpha subunit; GLUT1, Glucose transporter type 1; HK-1, Hexokinase 1).

HBx induces chemoresistance in diffuse large B cell lymphoma by inhibiting intrinsic apoptosis via the NF-κB/XIAP pathway

Diffuse large B-cell lymphoma (DLBCL) is the predominant subtype of malignant lymphoma in adults with high heterogeneity. Hepatitis B virus (HBV) has been shown to infect B lymphocytes and has been associated with a higher risk of developing DLBCL, most clearly in countries where HBV is endemic. Accumulating evidence suggests the standard chemotherapy regimens for DLBCL patients with HBV infection exhibit limited efficacy and unfavorable outcomes. The HBx antigen, encoded by the X gene in the four open reading frames of HBV, maybe a key molecule promoting the heightened malignant biological characteristics of DLBCL, but whether it affects the chemotherapy response and the mechanism in DLBCL remains unclear. Through the implementation of in vitro and vivo experiments, our study demonstrates that HBx antigen triggers excessive activation of the NF-κB pathway, resulting in increased expression of X-linked inhibitor of apoptosis protein (XIAP). This upregulation inhibits caspase 3-mediated intrinsic apoptosis and enhances resistance to first-line chemotherapeutic agents like epirubicin and vincristine in DLBCL. These findings offer insights into the development of innovative combination therapies for DLBCL patients with HBV infection.

The role of trimethylation on histone H3 lysine 27 (H3K27me3) in temozolomide resistance of glioma

Temozolomide (TMZ) is the first-line chemotherapeutic agent for malignant glioma, but its resistance limited the benefits of the treated patients. In this study, the role and significance of trimethylation of histone H3 lysine 27 (H3K27me3) in TMZ resistance were investigated. Data from twenty advanced glioma patients were collected, and their pathological samples were analyzed for H3K27me3 levels. TMZ sensitivity was compared between glioma cells U87 and TMZ-resistant cells U87TR, with H3K27me3 levels determined in both cells. The effects of H3K27me3 demethylases inhibitor GSK-J4, combined with TMZ, were assessed on the proliferation and migration of U87TR cells. The results indicated that a high level of H3K27me3 predicts longer disease free survival (DFS) and overall survival (OS) in glioma patients receiving TMZ treatment. The H3K27me3 level was lower in U87TR cells compared to U87 cells. GSK-J4 increased the H3K27me3 level in U87TR cells and decreased their resistance to TMZ. In summary, this study identified a novel marker of TMZ resistance in glioma and provided a new strategy to address this challenge. These findings are significant for improving the clinical treatment of glioma in the future.

The Chemo-Immunotherapeutic Roles of Tumor-Derived Extracellular Vesicle-Based Paclitaxel Delivery System in Hepatocarcinoma.

As a first-line chemotherapeutic agent, albumin-bound paclitaxel (PA) has a considerable effect on the treatment of various cancers. However, in chemotherapy for hepatocarcinoma, the sensitivity to PA is low owing to the innate resistance of hepatocarcinoma cells; the toxicity and side effects are severe, and the clinical treatment impact is poor. In this study, we present a unique nanodrug delivery system. The ultraviolet (UV)-induced tumor-cell-derived extracellular vesicles (EVs) were isolated and purified by differential centrifugation. Then, PA was loaded by coextrusion to create a vesicle drug delivery system (EVPA). By employing the EV-dependent enhanced retention effect and specific homing effect, EVPA would passively and actively target tumor tissues, activate the immune response to release PA, and achieve the combination therapeutic effect of chemo-immunotherapy on hepatocarcinoma. We demonstrated that the tumor-killing effect of EVPA is superior to that of PA, both in vivo and in vitro and that EVPA can be effectively taken up by hepatocarcinoma and dendritic cells, activate the body's specific immune response, promote the infiltration of CD4+ and CD8+ T cells in tumor tissues, and exert a precise killing effect on hepatocarcinoma cells via chemo-immunotherapy.

Divine noni's protective impact on Swiss albino mice's short-term memory impairment caused by cyclophosphamide: A behavioral and biochemical approach

Cyclophosphamide (CYL) is a first-line cancer chemotherapeutic agent widely used for the treatment of cancer that has severe toxic effects. The primary mechanism by which CYL induces toxicity through free radical generation. Morinda citrifolia (Noni) fruit juice is an herbal remedy documented to have antioxidant properties. The aim of the current study was to investigate the protective effect of noni against CYL-induced memory impairment in Swiss albino mice. Treatment schedule: Group 1: Normal: Received vehicle; Group 2: CYL treatment: Received CYL (40.0 mg/kg b.w. i.p.) on day one; Group 3: NJ treatment: Received NJ (360 mg/b.w. p.o.) once daily for 14 days. Group 4: DNG treatment: DNG (360 mg/b.w. p.o.) once daily for 14 days, Group 5: NJ + CYL treatment: Received CYL (40.0 mg/kg b.w. i.p.) on day one and after half an hour of received NJ (360 mg/b.w. p.o.) once daily for 14 days. Group 6: DNG + CYL treatment: Received CYL (40.0 mg/kg b.w. i.p.) on day one and after half an hour received DNG (360 mg/b.w. p.o.) once daily for 14 days. Mice were subjected to the Morris water maze (MWM) challenge for two weeks as part of a behavioral study. Short-term memory impairment was observed in the behavioral activity of CYL-treated mice in the MWM test in the 1st week trial, and this effect was reversed in the 2nd week trial in the combination treatment group. The behavioral analysis proved that noni supplementation reduced the risk of memory impairment caused by CYL. Biochemical analysis revealed that CYL markedly increased the levels of AChE and MDA in brain tissue. Similarly, decreases in the levels of antioxidants, i.e., GSH, CAT, SOD and GST, were detected in the brain tissue of the mice exposed to CYL. Qualitative and quantitative examinations of histopathological examination of the mouse hippocampus supported the above findings. The results demonstrated that noni supplement therapy reversed the changes in the MDA, AChE, and antioxidant enzyme levels while improving the behavioral and histological alterations caused by CYL. Long-term hippocampal growth and memory are unaffected, suggesting that CYL is less harmful. According to our research, supplementing with noni in conjunction with CYL may be a helpful treatment strategy for treating memory impairment caused by CYL.

An interactive dose optimizer based on population pharmacokinetic study to guide dosing of methotrexate in Chinese patients with osteosarcoma.

Osteosarcoma is a rare tumor with an incidence of 4.4 cases per million per year in adolescent. High-dose methotrexate (HD-MTX) is the standard first-line chemotherapeutic agent for osteosarcoma. However, its efficacy can vary significantly among individuals due to wide pharmacokinetic variability. Despite this, only a few population pharmacokinetics (popPK) models based on Chinese patients with osteosarcoma have been reported. Thus, this study aimed to develop a HD-MTX popPK model and an individual model-based dose optimizer for osteosarcoma therapy. A total of 680 MTX serum concentrations from 57 patients with osteosarcoma were measured at the end of MTX infusion and 10h, 24h, 48h, and 72h after the start of infusion. Using the first-order conditional estimation method with NONMEM, a popPK model was estimated. Goodness-of-fit plots, visual predictive checks, and bootstrap analysis were generated to evaluate the final model. A dose optimizer tool was developed based on the validated models using R Shiny. Additionally, clinical data from 12 patients with newly diagnosed osteosarcoma were collected and used as the validation set to preliminarily verify the predictive ability of the popPK model and the dose optimizer tool. Body surface area (BSA) was the most significant covariate for compartment distribution. Creatinine clearance (CrCL) and co-administration of NSAIDs were introduced as predictors for central compartmental and peripheral compartmental clearance, respectively. Co-administration of NSAIDs was associated with significantly higher MTX concentrations at 72h (p = 0.019). The dose optimizer tool exhibited a high consistency in predicting MTX AUC compared to the actual AUC (r = 0.821, p < 0.001) in the validation set. The dose optimizer tool could be used to estimate individual PK parameters, and optimize personalized MTX therapy in particular patients.

A Dual Bispecific Hydrolysis Peptide-Drug Conjugate Responsive to Micro-Acidic and Reduction Circumstance Promotes Antitumor Efficacy in Triple-Negative Breast Cancer.

Paclitaxel and its derivates are the first-line chemotherapeutic agents of breast cancer, which also showed tremendous clinical value in many other diseases including ovarian cancer, lung cancer etc. However, there are many drawbacks for almost all paclitaxel or its derivates, including extremely short half-life, poor solubility and adverse events, which significantly limits their clinical applications. In this work, we designed and constructed a bispecific hydrolysis PAP-SS-PTX (term as PDC), consisting with pro-apoptosis peptide (PAP) and paclitaxel (PTX) that were conjugated together via disulfide and ester bonds. On the one hand, PAP could improve the solubility of PTX and promote cellular uptake for drugs. On the other hand, it was able to prolong the PTX half-life. We performed series of chemo-dynamical assays and showed that PDC would release active drug molecules under micro-acidic and reduction circumstance. The further assays elucidated that PDC could interrupt DNA synthesis and arrest cell division through downregulating CDK4/6 and Histone methylation that inhibit tumor growth in vitro. What's more, it could not only inhibit 4T1 breast tumor growth, but also prolong the survival time of mice and exert antitumor efficacy in vivo. It may provide a new research idea for cancer therapies via controlled release strategy in tumor microenvironment.

Cisplatin-induced pyroptosis: a double-edged sword in cancer treatment

Abstract Cancer is a major cause of death worldwide and a serious threat to human health. Cisplatin, a widely used first-line chemotherapeutic agent for various solid tumors, is renowned for its efficacy but is limited by significant cytotoxicity. Cisplatin triggers pyroptosis in tumor cells by activating Gasdermin proteins, thereby enhancing its anticancer efficacy. However, this same mechanism can induce pyroptosis in normal cells, causing inflammation and toxicity in healthy tissues, such as nephrotoxicity and ototoxicity. The objective of this review is to identify the major molecular targets for optimizing the cisplatin treatment window by summarizing recent advances in the pyroptosis caused by cisplatin in different cancer types and normal tissues. Among them, gasdermin D and gasdermin E are the main molecular targets involved in cisplatin-induced pyroptosis, and GSDMB also has similar effects. Future research directions include exploring targeted drug delivery systems and target regulating GSDMs (gasdermin protein family) to selectively modulate pyroptosis, thereby maximizing cisplatin’s anticancer effects while minimizing its side effects. Therefore, this review provides a comprehensive overview of cisplatin-induced pyroptosis, offering new insights into therapeutic strategies in cancer treatment.

AB045. E2F6 promotes temozolomide resistance in glioblastoma by enrichment in CARD6 and POSTN promoter region.

Glioblastoma (GBM) is the most aggressive primary malignant brain tumor. Temozolomide (TMZ) is the most used first-line chemotherapeutic agent for GBM after surgery, but acquired resistance to TMZ frequently leads to treatment failure and is a major challenge in the clinical treatment of GBM. Increasing evidence suggests that E2F transcription factor 6 (E2F6) is associated with a variety of tumor malignant biological behaviors and drug resistance, but its biological function and underlying molecular mechanisms in GBM are unknown. The study investigated the levels of E2F6 in both TMZ-sensitive and TMZ-resistant GBM cells and tissues using Western blotting and immunofluorescence assays. In vitro experiments were conducted to explore the impact of E2F6 on TMZ resistance and glioma stem cell stemness. These experiments included Western blotting, colony formation assay, flow cytometry assay, and TdT-mediated dUTP nick-end labeling (TUNEL) assay. Bioinformatic analyses were conducted to investigate the mechanism behind the high expression of E2F6 in TMZ-resistant cells and its correlation with caspase recruitment domain 6 (CARD6) and disulfide-linked cell adhesion protein (POSTN). The study employed bioinformatic analyses, messenger RNA (mRNA) sequencing, chromatin immunoprecipitation sequencing assay, immunofluorescence, quantitative real-time polymerase chain reaction (qRT-PCR), and Western blotting. To examine the function of E2F6, an intracranial xenograft tumor mouse model was used for in vivo experiments. It was found that CARD6 and POSTN were significantly associated with TMZ resistance and survival of GBM patients. E2F6 was up-regulated in TMZ-resistant cells and tissues. Knockdown of E2F6 down-regulated the expression of CARD6, promoted TMZ-induced apoptosis, and enhanced chemo-sensitivity, whereas its overexpression significantly increased TMZ resistance in vitro and in vivo. In addition, E2F6 can promote TMZ resistance through stem-like properties acquisition. We identified a signaling pathway related to E2F6 and POSTN, which maintains the self-renewal of GBM stem cells (GSCs). E2F6 concentrates in the promoter region of POSTN, thereby regulating the expression of GSCs-related genes cluster of differentiation 133 (CD133), Nestin, and sex-determining region Y-box 2 (SOX2), which may be involved in tumor metabolism and drug resistance processes. Down-regulation of E2F6 down-regulated the expression of POSTN and inhibited tumor growth in nude mice. These results suggest that the E2F6-CARD6/POSTN signaling axis regulates the malignant biological behaviors of GBM and TMZ resistance. These findings are expected to provide promising therapeutic targets for CARD6 overcoming GBM TMZ resistance.

Adjuvant Properties of Caffeic Acid in Cancer Treatment.

Caffeic acid (CA) is a polyphenol belonging to the phenylpropanoid family, commonly found in plants and vegetables. It was first identified by Hlasiwetz in 1867 as a breakdown product of caffetannic acid. CA is biosynthesized from the amino acids tyrosine or phenylalanine through specific enzyme-catalyzed reactions. Extensive research since its discovery has revealed various health benefits associated with CA, including its antioxidant, anti-inflammatory, and anticancer properties. These effects are attributed to its ability to modulate several pathways, such as inhibiting NFkB, STAT3, and ERK1/2, thereby reducing inflammatory responses, and activating the Nrf2/ARE pathway to enhance antioxidant cell defenses. The consumption of CA has been linked to a reduced risk of certain cancers, mitigation of chemotherapy and radiotherapy-induced toxicity, and reversal of resistance to first-line chemotherapeutic agents. This suggests that CA could serve as a useful adjunct in cancer treatment. Studies have shown CA to be generally safe, with few adverse effects (such as back pain and headaches) reported. This review collates the latest information from Google Scholar, PubMed, the Phenol-Explorer database, and ClinicalTrials.gov, incorporating a total of 154 articles, to underscore the potential of CA in cancer prevention and overcoming chemoresistance.

Synergistic anti-osteosarcoma cell effects of the methotrex-ate/PI3K/mTOR inhibitor nanoparticle codelivery system

ABSTRACT Advanced osteosarcoma (OS) has low responsiveness to treatment regimens. Methotrexate (MTX), the first-line chemotherapeutic agent for advanced OS, frequently suffers from severe side effects that lead to chemotherapy interruption. To improve the efficacy and reduce the toxic side effects, we constructed a PF@MTX NP nano-delivery system using MTX-ss-γPGA polymer as a drug carrier loaded with PF. The average size of PF@MTX NPs was approximately 171.9 ± 2.13 nm with a zeta potential of approximately -32.91 ± 0.03 mV, uniformly distributed. We found that the nano showed a significant slowdown in MTX and PF release within 48 h and exhibited GSH-responsive pH sensitivity. In addition, the results of cellular uptake assay, toxicity, scratch and AO/EB staining assays showed that the PF@MTX NPs nanoparticles were able to enter the cells and induced 143B cell death and migration. Thus, the PF@MTX NPs nano-delivery system provides an effective strategy for the combined treatment of solid osteosarcoma.

The use of green protic ionic liquids in the crystallization of isoniazid: Evaluation of physicochemical and biological properties of drug

This study evaluated the synthesis of protic ionic liquids (PILs), 2-hydroxy ethylammonium formate (2-HEAF) and 2-hydroxy ethylammonium acetate (2-HEAA), and their applicability in the crystallization process of the active pharmaceutical ingredient isoniazid (INH) as anti-solvent. Isoniazid is an antibiotic used in the treatment of tuberculosis infections, being used as a first-line chemotherapeutic agent against Mycobacterium tuberculosis. Futhermore, this investigation was conducted in order to evaluate how these PILs can influence the habit, solubility, stability, and therapeutic efficiency of the obtained isoniazid crystals. The 2-HEAF and 2-HEAA PILs were easily formed in reactions between ethanolamine and carboxylic acids (formic or acetic acid), and they have no toxicity against Artemia salina. The PILs were able to crystallize isoniazid, influencing the crystal habit and size. The greatest variations in the hydrogen signals of the NH2 and NH groups of the amine and low variations in the chemical shifts of the hydrogens of the cation of the ethanolamine group from 2-HEAA and 2-HEAF indicate that PILs establish possibly weak interactions with INH. The obtained crystals were amorphous and showed higher solubility in water than standard INH. Moreover, these crystals showed therapeutic efficiency inantimycobacterial activity to inhibit the growth of Mycobacterium tuberculosis. The INH:2-HEAF only degraded 5.1 % (w/w), however, INH:2-HEAA degraded 32.8 % (w/w) after 60 days in an accelerated atmosphere. Then, the 2-HEAA and 2-HEAF were able to crystallize isoniazid, being a new application for these PILs. The used PILs also influenced the characteristics of isoniazid crystals.

The tumor-associated fibrotic reactions in microenvironment aggravate glioma chemoresistance.

Malignant gliomas are one of the most common and lethal brain tumors with poor prognosis. Most patients with glioblastoma (GBM) die within 2 years of diagnosis, even after receiving standard treatments including surgery combined with concomitant radiotherapy and chemotherapy. Temozolomide (TMZ) is the first-line chemotherapeutic agent for gliomas, but the frequent acquisition of chemoresistance generally leads to its treatment failure. Thus, it's urgent to investigate the strategies for overcoming glioma chemoresistance. Currently, many studies have elucidated that cancer chemoresistance is not only associated with the high expression of drug-resistance genes in glioma cells but also can be induced by the alterations of the tumor microenvironment (TME). Numerous studies have explored the use of antifibrosis drugs to sensitize chemotherapy in solid tumors, and surprisingly, these preclinical and clinical attempts have exhibited promising efficacy in treating certain types of cancer. However, it remains unclear how tumor-associated fibrotic alterations in the glioma microenvironment (GME) mediate chemoresistance. Furthermore, the possible mechanisms behind this phenomenon are yet to be determined. In this review, we have summarized the molecular mechanisms by which tumor-associated fibrotic reactions drive glioma transformation from a chemosensitive to a chemoresistant state. Additionally, we have outlined antitumor drugs with antifibrosis functions, suggesting that antifibrosis strategies may be effective in overcoming glioma chemoresistance through TME normalization.

Py-CoMFA, docking, and molecular dynamics simulations of Leishmania (L.) amazonensis arginase inhibitors

Leishmaniasis is a disease caused by a protozoan of the genus Leishmania, affecting millions of people, mainly in tropical countries, due to poor social conditions and low economic development. First-line chemotherapeutic agents involve highly toxic pentavalent antimonials, while treatment failure is mainly due to the emergence of drug-resistant strains. Leishmania arginase (ARG) enzyme is vital in pathogenicity and contributes to a higher infection rate, thus representing a potential drug target. This study helps in designing ARG inhibitors for the treatment of leishmaniasis. Py-CoMFA (3D-QSAR) models were constructed using 34 inhibitors from different chemical classes against ARG from L. (L.) amazonensis (LaARG). The 3D-QSAR predictions showed an excellent correlation between experimental and calculated pIC50 values. The molecular docking study identified the favorable hydrophobicity contribution of phenyl and cyclohexyl groups as substituents in the enzyme allosteric site. Molecular dynamics simulations of selected protein–ligand complexes were conducted to understand derivatives’ interaction modes and affinity in both active and allosteric sites. Two cinnamide compounds, 7g and 7k, were identified, with similar structures to the reference 4h allosteric site inhibitor. These compounds can guide the development of more effective arginase inhibitors as potential antileishmanial drugs.

Helminth-derived molecules improve 5-fluorouracil treatment on experimental colon tumorigenesis

Colorectal cancer (CRC) is one of the most prevalent fatal neoplasias worldwide. Despite efforts to improve the early diagnosis of CRC, the mortality rate of patients is still nearly 50%. The primary treatment strategy for CRC is surgery, which may be accompanied by chemotherapy and radiotherapy. The conventional and first-line chemotherapeutic agent utilized is 5-fluorouracil (5FU). However, it has low efficiency. Combination treatment with leucovorin and oxaliplatin or irinotecan improves the effectiveness of 5FU therapy. Unfortunately, most patients develop drug resistance, leading to disease progression. Here, we evaluated the effect of a potential alternative adjuvant treatment for 5FU, helminth-derived Taenia crassiceps (TcES) molecules, on treating advanced colitis-associated colon cancer. The use of TcES enhanced the effects of 5FU on established colonic tumors by downregulating the expression of the immunoregulatory cytokines, Il-10 and Tgf-β, and proinflammatory cytokines, Tnf-α and Il-17a, and reducing the levels of molecular markers associated with malignancy, cyclin D1, and Ki67, both involved in apoptosis inhibition and the signaling pathway of β-catenin. TcES+5FU therapy promoted NK cell recruitment and the release of Granzyme B1 at the tumor site, consequently inducing tumor cell death. Additionally, it restored P53 activity which relates to decreased Mdm2 expression. In vitro assays with human colon cancer cell lines showed that therapy with TcES+5FU significantly reduced cell proliferation and migration by modulating the P53 and P21 signaling pathways. Our findings demonstrate, for the first time in vivo, that helminth-derived excreted/secreted products may potentiate the effect of 5FU on established colon tumors.

Targeting ferroptosis as a potential strategy to overcome the resistance of cisplatin in oral squamous cell carcinoma.

Oral squamous cell carcinoma (OSCC) is a crucial public health problem, accounting for approximately 2% of all cancers globally and 90% of oral malignancies over the world. Unfortunately, despite the achievements in surgery, radiotherapy, and chemotherapy techniques over the past decades, OSCC patients still low 5-year survival rate. Cisplatin, a platinum-containing drug, serves as one of the first-line chemotherapeutic agents of OSCC. However, the resistance to cisplatin significantly limits the clinical practice and is a crucial factor in tumor recurrence and metastasis after conventional treatments. Ferroptosis is an iron-based form of cell death, which is initiated by the intracellular accumulation of lipid peroxidation and reactive oxygen species (ROS). Interestingly, cisplatin-resistant OSCC cells exhibit lower level of ROS and lipid peroxidation compared to sensitive cells. The reduced ferroptosis in cisplatin resistance cells indicates the potential relationship between cisplatin resistance and ferroptosis, which is proved by recent studies showing that in colorectal cancer cells. However, the modulation pathway of ferroptosis reversing cisplatin resistance in OSCC cells still remains unclear. This article aims to concisely summarize the molecular mechanisms and evaluate the relationship between ferroptosis and cisplatin resistance OSCC cells, thereby providing novel strategies for overcoming cisplatin resistance and developing new therapeutic approaches.

Anti-Tumor Efficacy of Oleuropein-Loaded ZnO/Au Mesoporous Silica Nanoparticle in 5-FU-Resistant Colorectal Cancer Cells.

5-fluorouracil (5-FU) is a first-line chemotherapeutic agent used to treat colorectal cancer (CRC). However, 5-FU induces drug resistance and activation of cancer stem cells (CSCs). In the present study, we designed a novel biocompatible nanomedicine system with high efficacy and biocompatibility by synthesizing mesoporous silica nanoparticle (MSN)-structured ZnO and gold ions. Oleuropein (OLP) is a phenolic compound derived from olive leaves that exerts anti-cancer effects. Therefore, we synthesized OLP-loaded ZnO/Au MSNs (ZnO/Au/OLP MSNs) and examined their anti-cancer effects on 5-FU-resistant CRC cells. ZnO/Au MSNs were synthesized and functionalized, and their physical and chemical compositions were characterized using UV-visible spectroscopy, dynamic light scattering, and transmission electron microscopy (TEM). Their effects were assessed in terms of cellular proliferation capacity, migration and invasion ability, colony-forming ability, spheroid-forming ability, reactive oxygen species (ROS) production, and mitochondrial membrane depolarization. ZnO/Au MSNs were mostly composed of various ions containing ZnO and gold ions, had a spheroid phenotype, and exhibited no cytotoxicity. ZnO/Au/OLP MSNs reduced cell viability and CSC formation and induced apoptosis of 5-FU-resistant CRC cells via necrosis via ROS accumulation and DNA fragmentation. ZnO/Au/OLP MSNs exhibited anti-cancer activity by upregulating necrosis. These results revealed that ZnO/Au/OLP MSNs are a novel drug delivery system for 5-FU CRC therapy.

Novel insights into the role of translesion synthesis polymerase in DNA incorporation and bypass of 5-fluorouracil in colorectal cancer.

5-Fluorouracil (5-FU) is the first-line chemotherapeutic agent in colorectal cancer, and resistance to 5-FU easily emerges. One of the mechanisms of drug action and resistance of 5-FU is through DNA incorporation. Our quantitative reverse-transcription PCR data showed that one of the translesion synthesis (TLS) DNA polymerases, DNA polymerase η (polη), was upregulated within 72 h upon 5-FU administration at 1 and 10 μM, indicating that polη is one of the first responding polymerases, and the only TLS polymerase, upon the 5-FU treatment to incorporate 5-FU into DNA. Our kinetic studies revealed that 5-fluoro-2'-deoxyuridine triphosphate (5FdUTP) was incorporated across dA 41 and 28 times more efficiently than across dG and across inosine, respectively, by polη indicating that the mutagenicity of 5-FU incorporation is higher in the presence of inosine and that DNA lesions could lead to more mutagenic incorporation of 5-FU. Our polη crystal structures complexed with DNA and 5FdUTP revealed that dA:5FdUTP base pair is like dA:dTTP in the active site of polη, while 5FdUTP adopted 4-enol tautomer in the base pairs with dG and HX increasing the insertion efficiency compared to dG:dTTP for the incorrect insertions. These studies confirm that polη engages in the DNA incorporation and bypass of 5-FU.

Meta-analysis of microarray data to determine gene indicators involved in cisplatin resistance in non-small cell lung cancer.

Lung cancer is a major cause of cancer-related mortality worldwide, with a 5-year survival rate of approximately 22%. Cisplatin is one of the standard first-line chemotherapeutic agents for non-small cell lung cancer (NSCLC), but its efficacy is often limited by the development of resistance. Despite extensive research on the molecular mechanisms of chemoresistance, the underlying causes remain elusive and complex. We analyzed three microarray datasets to find the gene signature and key pathways related to cisplatin resistance in NSCLC. We compared the gene expression of sensitive and resistant NSCLC cell lines treated with cisplatin. We found 274 DEGs, including 111 upregulated and 163 downregulated genes, in the resistant group. Gene set enrichment analysis showed the potential roles of several DEGs, such as TUBB2B, MAPK7, TUBAL3, MAP2K5, SMUG1, NTHL1, PARP3, NTRK1, G6PD, PDK1, HEY1, YTHDF2, CD274, and MAGEA1, in cisplatin resistance. Functional analysis revealed the involvement of pathways, such as gap junction, base excision repair, central carbon metabolism, and Notch signaling in the resistant cell lines. We identified several molecular factors that contribute to cisplatin resistance in NSCLC cell lines, involving genes and pathways that regulate gap junction communication, DNA damage repair, ROS balance, EMT induction, and stemness maintenance. These genes and pathways could be targets for future studies to overcome cisplatin resistance in NSCLC.

Crocin enhances the sensitivity to paclitaxel in human breast cancer cells by reducing BIRC5 expression.

Paclitaxel (PTX) is one of the first-line chemotherapeutic agents for treating breast cancer. However, PTX resistance remains a major hurdle in breast cancer therapy. Crocin, the main chemical constituent of saffron, shows anti-cancer activity against various types of cancer. However, the effect of crocin on the resistance of PTX in breast cancer is still unknown. CCK-8 and TUNEL assays were employed to detect cell viability and apoptosis, respectively. The targets of crocin were predicted using HERB database and the targets associated with breast cancer were acquired using GEPIA database. The Venn diagram was utilized to identify the common targets between crocin and breast cancer. Baculoviral inhibitor of apoptosis repeat containing 5 (BIRC5) expression was detected by qRT-PCR and western blot analysis. The correlation between BIRC5 expression and survival was analyzed by Kaplan-Meier plotter and PrognoScan databases. Our data suggested that crocin aggravated PTX-induced decrease of viability and increase of apoptosis in MCF-7 and MCF-7/PTX cells. BIRC5 was identified as the target of crocin against breast cancer. Crocin inhibited BIRC5 expression in MCF-7 and MCF-7/PTX cells. BIRC5 is overexpressed in breast cancer tissues, as well as PTX-sensitive and PTX-resistant breast cancer cells. BIRC5 expression is related to the poor survival of patients with breast cancer. Depletion of BIRC5 strengthened PTX-induced viability reduction and promotion of apoptosis in MCF-7 and MCF-7/PTX cells. Moreover, BIRC5 overexpression reversed the inhibitory effect of crocin on PTX resistance in breast cancer cells. In conclusion, crocin enhanced the sensitivity of PTX in breast cancer cells partially through inhibiting BIRC5 expression.