Mechanisms of Multidrug Resistance in Cancer Chemotherapy

Status Quo in the Liposome-Based Therapeutic Strategies Against Glioblastoma: "Targeting the Tumor and Tumor Microenvironment"

Glioblastoma is the most aggressive and fatal brain cancer, characterized by a high growth rate, invasiveness, and treatment resistance. The presence of the blood-brain barrier (BBB) and blood-brain tumor barrier (BBTB) poses a challenging task for chemotherapeutics, resulting in low efficacy, bioavailability, and increased dose-associated side effects. Despite the rigorous treatment strategies, including surgical resection, radiotherapy, and adjuvant chemotherapy with temozolomide, overall survival remains poor. The failure of current chemotherapeutics and other treatment regimens in glioblastoma necessitates the development of new drug delivery methodologies to precisely and efficiently target glioblastoma. Nanoparticle-based drug delivery systems offer a better therapeutic option in glioblastoma, considering their small size, ease of diffusion, and ability to cross the BBB. Liposomes are a specific category of nanoparticles made up of fatty acids. Furthermore, liposomes can be surface-modified to target a particular receptor and are nontoxic. This review discusses various methods of liposome modification for active/directed targeting and various liposome-based therapeutic approaches in the delivery of current chemotherapeutic drugs and nucleic acids in targeting the glioblastoma and tumor microenvironment.

Soloxolone N-3-(Dimethylamino)propylamide Restores Drug Sensitivity of Tumor Cells with Multidrug-Resistant Phenotype via Inhibition of P-Glycoprotein Efflux Function

Multidrug resistance (MDR) remains a significant challenge in cancer therapy, primarily due to the overexpression of transmembrane drug transporters, with P-glycoprotein (P-gp) being a central focus. Consequently, the development of P-gp inhibitors has emerged as a promising strategy to combat MDR. Given the P-gp targeting potential of soloxolone amides previously predicted by us by an absorption, distribution, metabolism, excretion, and toxicity (ADMET) analysis, the aim of the current study was to experimentally verify their P-gp inhibitory and MDR reversing activities in vitro. Screening of soloxolone amides as modulators of P-gp using molecular docking and cellular P-gp substrate efflux assays revealed the ability of compound 4 bearing a N-3-(dimethylamino)propylamide group to interact with the active site of P-gp and inhibit its transport function. Blind and site-specific molecular docking accompanied by a kinetic assay showed that 4 directly binds to the P-gp transmembrane domain with a binding energy similar to that of zosuquidar, a third-generation P-gp inhibitor (ΔG = -10.3 kcal/mol). In vitro assays confirmed that compound 4 enhanced the uptake of Rhodamine 123 (Rho123) and doxorubicin (DOX) by the P-gp-overexpressing human cervical carcinoma KB-8-5 (by 10.2- and 1.5-fold, respectively (p < 0.05, unpaired t-test)) and murine lymphosarcoma RLS40 (by 15.6- and 1.75-fold, respectively (p < 0.05, unpaired t-test)) cells at non-toxic concentrations. In these cell models, 4 showed comparable or slightly higher activity than the reference inhibitor verapamil (VPM), with the most pronounced effect of the hit compound in Rho123-loaded RLS40 cells, where 4 was 2-fold more effective than VPM. Moreover, 4 synergistically restored the sensitivity of KB-8-5 cells to the cytotoxic effect of DOX, demonstrating MDR reversal activity. Based on the data obtained, 4 can be considered as a drug candidate to combat the P-gp-mediated MDR of tumor cells and semisynthetic triterpenoids, with amide moieties in general representing a promising scaffold for the development of novel therapeutics for tumors with low susceptibility to antineoplastic agents.

Unveiling the potential of medicinal herbs as the source for in vitro screening toward the inhibition of Nrf2

Background

Drug resistance is one of the leading causes attributed to the failure of cancer treatment by chemotherapy. Nuclear factor erythroid 2-related factor 2 (Nrf2) is a transcription factor regulating gene expression in cell defense against oxidative stress or hazardous factors. Taking advantage of this feature, Nrf2 also serves as the bodyguard for both normal and cancer cells. Many pieces of evidence have reported that inhibiting Nrf2 activity in cancer cells can reverse chemotherapy drug resistance. In addition, secondary metabolites from medicinal plants have been reported to inhibit Nrf2 activity in the in vitro study. This study aimed to preliminarily investigate fractions from medicinal herbs that inhibit Nrf2 activity in Huh7 liver cancer cells, thereby establishing a basis for subsequent isolation and extraction processes.

Materials and methods

Sub-fractions from five medicinal plants have been evaluated the Nrf2 inhibitor activity on Huh7 cells through luciferase-reported genes assay. Thin-layer chromatography (TLC) was also performed to quantify the extracts' main phytochemistry components. Combining the half-maximal inhibitory concentration (IC50) and half-maximal cytotoxicity concentration (CC50) enables us to determine which extracts have the potential for further isolation steps.

Results

Ten over 30 crude extracts and sub-fractions showed the inhibition of Nrf2 activity with the percentage ranging from 30 to 97 %. The methanol and n-hexane sub-fractions from Helicteres hirsuta Lour. leaves showed the strongest inhibition ability on Nrf2 activity with the IC50 = 20.98 ± 3.67 and 42.22 ± 2.10 μg/mL, respectively. The TLC results showed the presence of steroids and terpenoids in the promising sub-fractions.

Conclusions

Combining the TLC results with the in vitro screening on Nrf2 activity screening of medicinal plants, the outcomes suggest the steroids and terpenoids in the methanol extract and hexane sub-fraction from Helicteres hirsuta Lour. leaves show promise towards inhibiting Nrf2 activity in liver cancer cell lines without toxicity in the normal cells.

Immunogenic cell death-based oncolytic virus therapy: A sharp sword of tumor immunotherapy

Tumor immunotherapy, especially immune checkpoint inhibitors (ICIs), has been applied in clinical practice, but low response to immune therapies remains a thorny issue. Oncolytic viruses (OVs) are considered promising for cancer treatment because they can selectively target and destroy tumor cells followed by spreading to nearby tumor tissues for a new round of infection. Immunogenic cell death (ICD), which is the major mechanism of OVs' anticancer effects, is induced by endoplasmic reticulum stress and reactive oxygen species overload after virus infection. Subsequent release of specific damage-associated molecular patterns (DAMPs) from different types of tumor cells can transform the tumor microenvironment from "cold" to "hot". In this paper, we broadly define ICD as those types of cell death that is immunogenic, and describe their signaling pathways respectively. Focusing on ICD, we also elucidate the advantages and disadvantages of recent combination therapies and their future prospects.

Role of Wnt/β-catenin pathway in cancer drug resistance: Insights into molecular aspects of major solid tumors

Adaptive resistance to conventional and targeted therapies remains one of the major obstacles in the effective management of cancer. Aberrant activation of key signaling mechanisms plays a pivotal role in modulating resistance to drugs. An evolutionarily conserved Wnt/β-catenin pathway is one of the signaling cascades which regulate resistance to drugs. Elevated Wnt signaling confers resistance to anticancer therapies, either through direct activation of its target genes or via indirect mechanisms and crosstalk over other signaling pathways. Involvement of the Wnt/β-catenin pathway in cancer hallmarks like inhibition of apoptosis, promotion of invasion and metastasis and cancer stem cell maintenance makes this pathway a potential target to exploit for addressing drug resistance. Accumulating evidences suggest a critical role of Wnt/β-catenin pathway in imparting resistance across multiple cancers including PDAC, NSCLC, TNBC, etc. Here we present a comprehensive assessment of how Wnt/β-catenin pathway mediates cancer drug resistance in majority of the solid tumors. We take a deep dive into the Wnt/β-catenin signaling-mediated modulation of cellular and downstream molecular mechanisms and their impact on cancer resistance.

Polyploid cancer cells reveal signatures of chemotherapy resistance

Therapeutic resistance in cancer significantly contributes to mortality, with many patients eventually experiencing recurrence after initial treatment responses. Recent studies have identified therapy-resistant large polyploid cancer cells in patient tissues, particularly in late-stage prostate cancer, linking them to advanced disease and relapse. Here, we analyzed bone marrow aspirates from 44 advanced prostate cancer patients and found the presence of CTC-IGC was significantly associated with poorer progression-free survival. Single cell copy number profiling of CTC-IGC displayed clonal origins with typical CTCs, suggesting complete polyploidization. Induced polyploid cancer cells from PC3 and MDA-MB-231 cell lines treated with docetaxel or cisplatin were examined through single cell DNA sequencing, RNA sequencing, and protein immunofluorescence. Novel RNA and protein markers, including HOMER1, TNFRSF9, and LRP1, were identified as linked to chemotherapy resistance. These markers were also present in a subset of patient CTCs and associated with recurrence in public gene expression data. This study highlights the prognostic significance of large polyploid tumor cells, their role in chemotherapy resistance, and their expression of markers tied to cancer relapse, offering new potential avenues for therapeutic development.

Systemic Codelivery of Thymoquinone and Doxorubicin by Targeted Mesoporous Silica Nanoparticle Sensitizes Doxorubicin-Resistant Breast Cancer by Interfering between the MDR1/P-gp and miR 298 Crosstalk

Multi drug resistance (MDR) in breast carcinoma still poses a significant impairment to successful chemotherapy. As the arsenal of anticancer agents increases with improved preclinical methods, the growth of therapeutic drug combinations is now unprecedented. The malignancies addressed by mono drugs often fail to limit cancer progression, resulting in resistant cancer, thereby offering combinatorial therapies a terrific edge over monodrug regimes. However, the selection of drug combinations required enough preliminary evidence for their synergistic effect. The fundamental mechanisms of MDR to chemotherapeutics are associated with the overexpression of membrane efflux pumps, alternations in drug targets, and increased drug metabolism. Unfortunately, it is very difficult for drugs to overcome resistance produced on their own or by another different drug action. In this context, herein, we report a simple delivery system for coencapsulation and intracellular codelivery of dual-drug thymoquinone (TQ) and doxorubicin (DOX) to resensitize DOX-resistant MDA MB231 cell line (231 R). The 231 R cell line developed in our lab showed an enhanced expression of the ATP-binding cassette (ABC) transporters P-gp1/MDR-1 and a declined miR-298 expression. The present delivery system is based on amine-functionalized mesoporous silica nanoparticles (MSNs), in which the side chain amine functional group was used to react with the carbonyl group of TQ, which acts as a pro-drug system (TQ-MSN) to release TQ and DOX simultaneously. DOX was encapsulated later into the above TQ-MSN by a simple diffusion method. The drugs containing MSNs were further coated with a hyaluronic acid-conjugated PEG-PLGA polymer (HA@TQ-DOX-MSN). This simple nanostrategy interferes with the MDR-1/miR-298 cross-talk, thereby allowing a significant reduction in drug efflux from the cell and highlighting a promising nanotechnology-based combinatorial delivery approach in managing breast cancer chemoresistance.

Tumor-associated macrophages/C-X-C motif chemokine ligand 1 promotes breast cancer autophagy-mediated chemoresistance via IGF1R/STAT3/HMGB1 signaling

Autophagy-mediated chemoresistance is the core mechanism for therapeutic failure and poor prognosis in breast cancer. Breast cancer chemotherapy resistance is believed to be influenced by tumor-associated macrophages (TAMs), by which C-X-C motif chemokine ligand 1 (CXCL1) is the most abundant cytokine secreted. Yet, its role in mediating autophagy-related chemoresistance is still unknown. This study aimed to explore the molecular mechanisms by which TAMs/CXCL1 induced autophagy-mediated chemoresistance in breast cancer. It was found that TAMs/CXCL1 promoted chemoresistance of breast cancer cells through autophagy activation in vitro, and CXCL1 silence could enhance the chemosensitivity of paclitaxel-resistant breast cancer cells via autophagy inhibition. A high-throughput quantitative PCR chip and subsequent target validation showed that CXCL1 induced autophagy-mediated chemoresistance by inhibiting VHL-mediated IGF1R ubiquitination. The elevated IGF1R then promoted STAT3/HMGB1 signaling to facilitate autophagy. Additionally, TAMs/CXCL1 silence improved paclitaxel chemosensitivity by suppressing autophagy in breast cancer mice xenografts, and clinical studies further linked CXCL1 to IGF1R/HMGB1 signaling, as well as shorter free survival of recurrence. Taken together, these results not only uncover the crucial role of TAMs/CXCL1 signaling in mediating breast cancer chemoresistance through enhancing autophagy, but also shed novel light on the molecular mechanism of IGF1R/STAT3/HMGB1 pathway in regulating autophagy and its impact on cancer prognosis.

Stimuli-Responsive Covalent Organic Frameworks for Cancer Therapy

Chemotherapy as a common anticancer therapeutic modality is often challenged by various obstacles such as poor stability, low solubility, and severe side effects of chemotherapeutic agents as well as multidrug resistance of cancerous cells. Nanoparticles in the role of carriers for chemotherapeutic drugs and platforms for combining different therapeutic approaches have effectively participated in overcoming such drawbacks. In particular, nanoparticles able to induce their therapeutic effect in response to specific stimuli like tumor microenvironment characteristics (e.g., hypoxia, acidic pH, high levels of glutathione, and overexpressed hydrogen peroxide) or extrinsic stimulus of laser light bring about more precise and selective treatments. Among them, nanostructures of covalent organic frameworks (COFs) have drawn great interest in biomedical fields during recent years. Possessing large surface area, high porosity, structural stability, and customizable architecture, these biocompatible porous crystalline polymers properly translate to promising platforms for drug delivery and induction of combination therapies. With the focus on stimuli-responsive characteristics of nanoscale COFs, this study aims to propose an overview of their potentiality in cancer treatment on the basis of chemotherapy alone or in combination with sonodynamic, chemodynamic, photodynamic, and photothermal therapies.

The Role of Microbiome and Probiotics in Chemo-Radiotherapy-Induced Diarrhea: A Narrative Review of the Current Evidence

BACKGROUND

In this article, we review the most recent research on probiotics effects on diarrhea in both human and animal models of the condition along with the therapeutic potential of these compounds based on their findings.

RECENT FINDINGS

Nearly 50%-80% of cancer patients experience chemotherapy-induced diarrhea (CID), serious gastrointestinal toxicity of chemotherapeutic and radiation regimens that leads to prolonged hospitalizations, cardiovascular problems, electrolyte imbalances, disruptions in cancer treatment, poor cancer prognosis, and death. CID is typically categorized as osmotic diarrhea. The depletion of colonic crypts and villi by radiotherapy and chemotherapy agents interferes with the absorptive function of the intestine, thereby decreasing the absorption of chloride and releasing water into the intestinal lumen. Probiotic supplements have been found to be able to reverse the intestinal damage caused by chemo-radiation therapy by promoting the growth of crypt and villi and reducing inflammatory pathways. In addition, they support the modulation of immunological and angiogenesis responses in the gut as well as the metabolism of certain digestive enzymes by altering the gut microbiota.

CONCLUSION

Beyond the benefits of probiotics, additional clinical research is required to clarify the most effective strain combinations and dosages for preventing chemotherapy and radiotherapy diarrhea.

Antitumor Potential of Guttiferone E Combined With Carboplatin Against Osimertinib-resistant H1975 Lung Cancer Through Apoptosis

BACKGROUND/AIM

Low selectivity and high frequency of side-effects are the major problems of currently used chemotherapeutics. Among natural compounds, the polyprenylated acylphloroglucinol, guttiferone E, isolated from Brazilian red propolis, has attracted attention due to its marked anticancer properties and was evaluated here for its role against osimertinib-resistant H1975 cells (with double mutations of epidermal growth factor receptor: EGFR L858R/T790M).

MATERIALS AND METHODS

Guttiferone E was obtained from red propolis using established extraction procedures. Guttiferone E was tested using the H1975 cell line in in vitro (2D and 3D) cell cultures and in vivo in BALB/c athymic nude mice. Live/dead assay was also performed to support the results. Tumor tissues obtained from in vivo studies were used for western blotting. Guttiferone E reduced H1975 cell viability in a concentration-dependent manner. The IC50 values in 2D and 3D cell lines were 2.56±0.12 μM and 11.25±0.34 μM. Furthermore, at 10 mg/kg intraperitoneally, guttiferone E significantly reduced the tumor volume in tumor xenografts when used alone and in combination with carboplatin. Guttiferone E and carboplatin displayed synergistic inhibition of H1975 cells and animal tumors. Co-treatment of guttiferone E with carboplatin induced more prominent apoptosis than treatment with either drug alone. Guttiferone E treatment induced cleavage of poly-ADP ribose polymerase and induced apoptosis by significantly reducing levels of mammalian target of rapamycin, sirtuin 1, sirtuin 7, superoxide dismutase, programmed death-ligand 1, and programmed cell death 1 in tumor tissues.

CONCLUSION

Our results show guttiferone E to be a promising, novel and potent antitumor drug candidate for osimertinib-resistant lung cancer with EGFR L858R/T790M mutations.

Personalized Versus Precision Nanomedicine for Treatment of Ovarian Cancer

The response to treatment is substantially varied between individual patients with ovarian cancer. However, chemotherapy treatment plans rarely pay sufficient attention to the mentioned factors. Instead, standardized treatment protocols are usually employed for most ovarian cancer patients. Variations in an individual's sensitivity to drugs significantly limit the effectiveness of treatment in some patients and lead to severe toxicities in others. In the present investigation, a nanotechnology-based approach for personalized treatment of ovarian carcinoma (the most lethal type of gynecological cancer) constructed on the individual genetic profile of the patient's tumor is developed and validated. The expression of predefined genes and proteins is analyzed for each patient sample. Finally, a mixture of the complex nanocarrier-based targeted delivery system containing drug(s)/siRNA(s)/targeted peptide is selected from the pre-synthesized bank and tested in vivo on murine cancer model using cancer cells isolated from tumors of each patient. Based on the results of the present study, an innovative approach and protocol for personalized treatment of ovarian cancer are suggested and evaluated. The results of the present study clearly show the advantages and perspectives of the proposed individual treatment approach.

FDA-approved antivirals ledipasvir and daclatasvir downregulate the Src-EPHA2-Akt oncogenic pathway in colorectal and triple-negative breast cancer cells

Direct-acting antivirals ledipasvir (LDV) and daclatasvir (DCV) are widely used as part of combination therapies to treat Hepatitis C infections. Here we show that these compounds inhibit the proliferation, invasion, and colony formation of triple-negative MDA-MB-231 breast cancer cells, SRC-transduced SW620 colon cancer cells and SRC- transduced NIH3T3 fibroblasts. DCV also inhibits the expression of PDL-1, which is responsible for resistance to immunotherapy in breast cancer cells. The demonstrated low toxicity in many Hepatitis C patients suggests LDV and DCV could be used in combination therapies for cancer patients. At the molecular level, these direct-acting antivirals inhibit the phosphorylation of Akt and the ephrin type A receptor 2 (EPHA2) by destabilizing a Src-EPHA2 complex, although they do not affect the general kinase activity of Src. Thus, LDV and DCV could be effective drugs for Src-associated cancers without the inherent toxicity of classical Src inhibitors.

Unveiling the anticancer potential of Pestalotioprolide E, an unexplored macrolide: Targeting TRXR1-TRX1-ASK1-P38 signaling cascade in triple-negative breast cancer

Triple-negative breast cancer (TNBC) is highly aggressive and metastatic in nature. Existing treatment modalities for TNBC are associated with severe side effects. Thioredoxin reductase (TRXR), the pivotal component of the thioredoxin system, remains overexpressed in various cancer cells including TNBC; promotes cell growth, proliferation, and metastasis, and inhibits apoptosis. Pestalotioprolide E is one of the potent macrolides, a class of secondary metabolites derived from an endophytic fungus Pestalotiopsis microspora with relatively unexplored biological activities. Our study revealed increased expression and activity of TRXR1 in MDA-MB-231 cells compared to the non-cancerous cells. In silico docking analysis and in vitro activity assay demonstrated that Pestalotioprolide E directly interacts with TRXR1 and inhibits its enzymatic activity. This inhibition induces apoptosis via TRX1/ASK1/P38MAPK death signaling cascade and retards metastasis through modulating VEGF, MMP-2, MMP-9, E-cadherin, N-cadherin in MDA-MB-231 cells. Taken together present study establishes TRXR1 as a molecular target for Pestalotioprolide E and its anticancer effect can be attributed to the inhibition of TRXR1 activity in MDA-MB-231.

Nano-drug delivery system for the treatment of multidrug-resistant breast cancer: Current status and future perspectives

Breast cancer (BC) is one of the most frequently diagnosed cancers in women. Chemotherapy continues to be the treatment of choice for clinically combating it. Nevertheless, the chemotherapy process is frequently hindered by multidrug resistance, thereby impacting the effectiveness of the treatment. Multidrug resistance (MDR) refers to the phenomenon in which malignant tumour cells develop resistance to anticancer drugs after one single exposure. It can occur with a broad range of chemotherapeutic drugs with distinct chemical structures and mechanisms of action, and it is one of the major causes of treatment failure and disease relapse. Research has long been focused on overcoming MDR by using multiple drug combinations, but this approach is often associated with serious side effects. Therefore, there is a pressing need for in-depth research into the mechanisms of MDR, as well as the development of new drugs to reverse MDR and improve the efficacy of breast cancer chemotherapy. This article reviews the mechanisms of multidrug resistance and explores the application of nano-drug delivery system (NDDS) to overcome MDR in breast cancer. The aim is to offer a valuable reference for further research endeavours.

Harnessing cells to improve transport of nanomedicines

Efficient tumour treatment is hampered by the poor selectivity of anticancer drugs, resulting in scarce tumour accumulation and undesired off-target effects. Nano-sized drug-delivery systems in the form of nanoparticles (NPs) have been proposed to improve drug distribution to solid tumours, by virtue of their ability of passive and active tumour targeting. Despite these advantages, literature studies indicated that less than 1% of the administered NPs can successfully reach the tumour mass, highlighting the necessity for more efficient drug transporters in cancer treatment. Living cells, such as blood cells, circulating immune cells, platelets, and stem cells, are often found as an infiltrating component in most solid tumours, because of their ability to naturally circumvent immune recognition, bypass biological barriers, and reach inaccessible tissues through innate tropism and active motility. Therefore, the tumour-homing ability of these cells can be harnessed to design living cell carriers able to improve the transport of drugs and NPs to tumours. Albeit promising, this approach is still in its beginnings and suffers from difficult scalability, high cost, and poor reproducibility. In this review, we present an overview of the most common cell transporters of drugs and NPs, and we discuss how different cell types interact with biological barriers to deliver cargoes of various natures to tumours. Finally, we analyse the different techniques used to load drugs or NPs in living cells and discuss their advantages and disadvantages.

Upregulation of miRNA-450b-5p targets ACTB to affect drug resistance and prognosis of ovarian cancer via the PI3K/Akt signaling pathway

Background

Ovarian cancer (OC) is the most malignant gynecologic cancer, and chemoresistance is a major cause of treatment failure in patients with OC. The understanding of microRNA (miRNA) in cancer is limited, and the role of miRNA (miR)-450b-5p in cancer drug resistance is unknown. In this study, we aim to evaluate the role of miR-450b-5p in drug-resistant OC and its underlying mechanisms.

Methods

MiR-450b-5p expression was assessed in drug-sensitive and resistant OC cells via quantitative real-time polymerase chain reaction. Cell viability was evaluated using the Cell Counting Kit-8 assay. Progression-free survival (PFS) and overall survival (OS) curves were generated using the Kaplan-Meier method and the log-rank test. Target genes of miR-450b-5p were identified from the Cancer MIRNome database. Co-expressed genes were obtained from The Cancer Genome Atlas and Cancer Genome cBioportal for pathway enrichment and functional clustering analysis.

Results

The miRNA-450b-5p expression was significantly increased in A2780 and SKOV3 OC-resistant cells and significantly increased by 17-fold in the A2780-CBP-Lv-miR-450b-5p cells compared to A2780-CBP and A2780-CBP-Lv-NC cells. The up-regulated expression of miR-450b-5p increased the cell viability and half maximal inhibitory concentration (IC50) of A2780 platinum-resistant cells and was associated with poor OS. We obtained 33 potential target genes of miR-450b-5p and beta-actin (ACTB) might be a potential target of miR-450b-5p. Low expression of ACTB predicted poor OS and PFS. We obtained 362 common genes co-expressed with ACTB, which involved 4 critical pathways. PI3K acted as an upstream pathway of the other three pathways, which ultimately responded to drug resistance regulation in OC. The genes enriched in four pathways were cross-analyzed and 13 overlapping genes were obtained. These 13 genes were also significantly and positively co-expressed with ACTB at both protein and mRNA levels.

Conclusions

High expression of miRNA-450b-5p might affect drug resistance and prognosis in OC by targeting 13 co-expressed genes of ACTB directly through the PI3K/Akt signaling pathway. Thus, miR-450b-5p might provide a new therapeutic target for drug resistance in OC.

Plant Metabolomics: The Future of Anticancer Drug Discovery

Drug development from medicinal plants constitutes an important strategy for finding natural anticancer therapies. While several plant secondary metabolites with potential antitumor activities have been identified, well-defined mechanisms of action remained uncovered. In fact, studies of medicinal plants have often focused on the genome, transcriptome, and proteome, dismissing the relevance of the metabolome for discovering effective plant-based drugs. Metabolomics has gained huge interest in cancer research as it facilitates the identification of potential anticancer metabolites and uncovers the metabolomic alterations that occur in cancer cells in response to treatment. This holds great promise for investigating the mode of action of target metabolites. Although metabolomics has made significant contributions to drug discovery, research in this area is still ongoing. In this review, we emphasize the significance of plant metabolomics in anticancer research, which continues to be a potential technique for the development of anticancer drugs in spite of all the challenges encountered. As well, we provide insights into the essential elements required for performing effective metabolomics analyses.

Molecular Mechanisms of Drug Resistance in Leishmania spp

The protozoan parasite Leishmania causes leishmaniasis, a neglected tropical disease, that disproportionately affects underdeveloped countries. This disease has major health, economic, and social implications, particularly because of the limited treatment options, high cost, the severe side effects associated with available therapeutics, and the high rate of treatment failure caused by the parasites' growing resistance to current medications. In this review, we describe first the common strategies used by pathogens to develop drug resistance and then focus on the arsenal of available drugs to treat leishmaniasis, their modes of action, and the molecular mechanisms contributing to drug resistance in Leishmania spp., including the role of genomic, transcriptional, and translational control. We focus more specifically on our recent discovery of translational reprogramming as a major driver of drug resistance leading to coordinated changes in the translation of transcripts and orchestrating changes in metabolome and lipidome to support drug resistance. A thorough understanding of these mechanisms is essential to identify the key elements needed to combat resistance and improve leishmaniasis treatment methods.

Beyond aromatherapy: can essential oil loaded nanocarriers revolutionize cancer treatment?

Cancer, a complex global health burden, necessitates the development of innovative therapeutic strategies. While chemotherapy remains the primary treatment approach, its severe side effects and chemoresistance drive the search for novel alternatives. Essential oils (EOs), consisting of diverse bioactive phytochemicals, offer promise as anticancer agents. However, their limitations, such as instability, limited bioavailability, and non-specific targeting, hinder their therapeutic potential. These challenges were circumvented by utilizing nanoparticles and nanosystems as efficient delivery platforms for EOs. This review highlights the accumulating evidence based on loading EOs into several nanocarriers, including polymeric nanoparticles, nanoemulsions, nanofibers, lipid-based nanocapsules and nanostructures, niosomes, and liposomes, as effective anticancer regimens. It covers extraction and chemical composition of EOs, their mechanisms of action, and targeting strategies to various tumors. Additionally, it delves into the diverse landscape of nanocarriers, including their advantages and considerations for cancer targeting and EO encapsulation. The effectiveness of EO-loaded nanocarriers in cancer targeting and treatment is examined, highlighting enhanced cellular uptake, controlled drug release, and improved therapeutic efficacy. Finally, the review addresses existing challenges and future perspectives, emphasizing the potential for clinical translation and personalized medicine approaches.

RNA editing enzyme ADAR2 regulates P-glycoprotein expression in murine breast cancer cells through the circRNA-miRNA pathway

Among the various RNA modifications, adenosine-to-inosine RNA editing, catalyzed by adenosine deaminase acting on RNA (ADAR) family, ADAR1 and ADAR2, is the most common nucleotide conversion in mammalian cells. The pathological relevance of ADAR expression has been highlighted in recent human genetic studies. Low expression of the ADAR2 gene is correlated with a poor prognosis in breast cancer patients, but the underlying mechanism remains enigmatic. In this study, we constructed Adar2-knockdown (Adar2-KD) murine breast cancer 4T1 cells and observed their reduced susceptibility to chemotherapeutic drug doxorubicin. Downregulation of ADAR2 induced the expression of P-glycoprotein (P-gp), leading to a reduction in the intracellular accumulation of doxorubicin. The upregulation of P-gp occurred at the post-transcriptional level due to the decreased miR-195a-3p function. The search for the underlying cause of the induction of P-gp expression in Adar2-KD 4T1 cells led to the identification of circular RNA (circRNA) circHif1a as a sponge for miR-195a-3p. The enhanced expression of circHif1a inhibited miR-195a-3p function, resulting in the upregulation of P-gp expression. These results suggest that ADAR2 acts as a suppressor of circHif1a biogenesis and then allows miR-195a-3p to interfere with P-gp translation. Our findings may help to improve drug efficacy by clarifying the mechanism of chemoresistance in breast cancer.

Copper selective 8-aminoquinoline based tetradentate chelators as anticancer agents

Cancer cell proliferation and metastasis are known to be dependent on angiogenesis which is regulated by several parameters including copper availability. Tetradentate monoquinoline (TDMQ) ligands constitute a series of chelators tailored to regulate copper homeostasis due to their specificity for copper(ii) with respect to Cu(i) or other biometals like iron or zinc. One of these chelators, TDMQ20 efficiently inhibits both proliferation and migration of several human cancer cell lines, better than the reference drug 5-fluorouracil, and with higher selectivity indexes with respect to non-cancer human cells. The biological activity of TDMQ20 may be driven by the coordination chemistry of copper, and the ability of this chelator to restore copper homeostasis and its subsequent redox properties. The anticancer mechanism of action of TDMQ20 involves intracellular production of reactive oxygen species, drastic mitochondrial damages and induction of tumor cell apoptosis. These data support the selection of TDMQ20 as drug-candidate against several human cancers.

Progress in Research of Nanotherapeutics for Overcoming Multidrug Resistance in Cancer

Chemotherapy has been widely applied in oncotherapy. However, the development of multidrug resistance (MDR) has diminished the effectiveness of anticancer drugs against tumor cells. Such resistance often results in tumor recurrence, metastasis, and patient death. Fortunately, nanoparticle-based drug delivery systems provide a promising strategy by codelivery of multiple drugs and MDR reversal agents and the skillful, flexible, smart modification of drug targets. Such systems have demonstrated the ability to bypass the ABC transporter biological efflux mechanisms due to drug resistance. Hence, how to deliver drugs and exert potential antitumor effects have been successfully explored, applied, and developed. Furthermore, to overcome multidrug resistance, nanoparticle-based systems have been developed due to their good therapeutic effect, low side effects, and high tumor metastasis inhibition. In view of this, we systematically discuss the molecular mechanisms and therapeutic strategies of MDR from nanotherapeutics. Finally, we summarize intriguing ideas and future trends for further research in overcoming MDR.

Utidelone-based therapy in advanced or metastatic solid tumors after failure of standard therapies: a prospective, multicenter, single-arm trial

Treatment options are limited for tumors after failure of standard therapies. Utidelone (UTD1), a novel microtubule stabilizer, given via 5 days intermittent infusion, has demonstrated high activity in heavily pretreated metastatic breast cancer, while its efficacy in other cancers was unclear. Peripheral neuropathy is a common and severe adverse event (AE) of UTD1. We performed a prospective, multicenter, single-arm trial (ChiCTR2300074299) to evaluate the efficacy and safety of UTD1 with a changed administration mode in patients with advanced or metastatic solid tumors after failure of standard therapies. UTD1 (150 mg/m2, alone or in combination with other anticancer agents) was administrated via 120 h continuous intravenous infusion every 21 days until disease progression or intolerable toxicity. A total of 50 patients were enrolled and analyzed, including 20 breast cancer patients, 11 gynecological cancer patients, 8 gastrointestinal cancer patients, 6 lung cancer patients, and 5 patients with other solid tumors. The overall median progression-free survival (PFS) was 4 months, the overall objective response rate and disease control rate were 20% and 66%, respectively, and the median overall survival was not reached. Most of the AEs were grade 1 or 2 and were manageable and reversible, the rate of grade ≥3 AEs including peripheral neuropathy was 4%. This study demonstrated a promising anti-tumor activity of UTD1 in patients with advanced or metastatic solid tumors after failure of the standard therapies. Moreover, 120 h continuous intravenous infusion was a more tolerable administration mode than 5 days intermittent infusion, and worthy of further study.

Regulating ferroptosis by non-coding RNAs in hepatocellular carcinoma

Ferroptosis, a unique type of regulated cell death plays a vital role in inhibiting tumour malignancy and has presented new opportunities for treatment of therapy in hepatocellular carcinoma. Accumulating studies indicate that epigenetic modifications by non-coding RNAs, including microRNAs, long noncoding RNAs, and circular RNAs, can determine cancer cell vulnerability to ferroptosis in HCC. The present review first summarize the updated core molecular mechanisms of ferroptosis. We then provide a concised overview of epigenetic modification of ferroptosis in HCC. Finally, we review the recent progress in understanding of the ncRNA-mediated regulated mechanisms on ferroptosis in HCC. The review will promote our understanding of the ncRNA-mediated epigenetic regulatory mechanisms modulating ferroptosis in malignancy of HCC, highlighting a novel strategies for treatment of HCC through targeting ncRNA-ferroptosis axis.

Application of omics technologies in studies on antitumor effects of Traditional Chinese Medicine

Traditional Chinese medicine (TCM) is considered to be one of the most comprehensive and influential form of traditional medicine. It plays an important role in clinical treatment and adjuvant therapy for cancer. However, the complex composition of TCM presents challenges to the comprehensive and systematic understanding of its antitumor mechanisms, which hinders further development of TCM with antitumor effects. Omics technologies can immensely help in elucidating the mechanism of action of drugs. They utilize high-throughput sequencing and detection techniques to provide deeper insights into biological systems, revealing the intricate mechanisms through which TCM combats tumors. Multi-omics approaches can be used to elucidate the interrelationships among different omics layers by integrating data from various omics disciplines. By analyzing a large amount of data, these approaches further unravel the complex network of mechanisms underlying the antitumor effects of TCM and explain the mutual regulations across different molecular levels. In this study, we presented a comprehensive overview of the recent progress in single-omics and multi-omics research focused on elucidating the mechanisms underlying the antitumor effects of TCM. We discussed the significance of omics technologies in advancing research on the antitumor properties of TCM and also provided novel research perspectives and methodologies for further advancing this research field.

Targeting METTL3 enhances the chemosensitivity of non-small cell lung cancer cells by decreasing ABCC2 expression in an m6A-YTHDF1-dependent manner

Patients with non-small cell lung cancer (NSCLC) are easily resistant to first-line chemotherapy with paclitaxel (PTX) or carboplatin (CBP). N6-methyladenosine (m6A) methyltransferase-like 3 (METTL3) has crucial functions in m6A modification and tumorigenesis. However, its role in chemoresistance of NSCLC is still elusive. Here, we demonstrated that METTL3 inhibitor STM2457 significantly reduced the IC50 values of PTX or CBP in NSCLC cells, and they showed a synergistic effect. Comparing with monotherapy, a combination of STM2457 and PTX or CBP exhibited more potent in vitro and in vivo anti-tumor efficacy. In addition, we found that ATP binding cassette subfamily C member 2 (ABCC2) was responsively elevated in cytomembrane after PTX or CBP treatment, and targeting METTL3 could reverse this effect. Mechanistically, targeting METTL3 decreased the m6A modification of ABCC2 mRNA and accelerated its mRNA degradation. Further studies revealed that YTHDF1 could bind and stabilize the m6A-modified mRNA of ABCC2, while YTHDF1 knockdown promoted it mRNA degradation. These results, taken together, demonstrate that targeting METTL3 enhances the sensitivity of NSCLC cells to PTX or CBP by decreasing the cytomembrane-localized ABCC2 in an m6A-YTHDF1-dependent manner, and suggest that METTL3 may be a potential therapeutic target for acquired resistance to PTX or CBP in NSCLC.

Research progress in tumor therapy of carrier-free nanodrug

Carrier-free nanodrugs are a novel type of drug constructed by the self-assembly of drug molecules without carrier involvement. They have the characteristics of small particle size, easy penetration of various barriers, targeting tumors, and efficient release. In recent years, carrier-free nanodrugs have become a hot topic in tumor therapy as they solve the problems of low drug loading, poor biocompatibility, and low uptake efficiency of carrier nanodrugs. A series of recent studies have shown that carrier-free nanodrugs play a vital role in the treatment of various tumors, with similar or better effects than carrier nanodrugs. Based on the literature published in the past decades, this paper first summarizes the recent progress in the assembly modes of carrier-free nanodrugs, then describes common therapeutic modalities of carrier-free nanodrugs in tumor therapy, and finally depicts the existing challenges along with future trends of carrier-free nanodrugs. We hope that this review can guide the design and application of carrier-free nanodrugs in the future.

Paradoxical cell targeting of calreticulin-empowered, protein-only nanoparticles

Surface-exposed calreticulin (CRT) serves as a crucial cell damage-associated molecular pattern for immunogenic apoptosis, by generating an "eat me" signal to macrophages. Aiming at precision immunotherapies we intended to artificially label tumoral cells in vivo with a recombinant CRT, in a targeted way. For that, we have constructed a CRT fusion protein intended to surface attach CXCR4+ cancer cells, to stimulate their immunological destruction. As a targeting ligand of the CRT construct and to drive its specific cell adhesion, we used the peptide V1, a derivative of the vMIP-II cytokine and an antagonist of CXCR4. The modular protein tends to self-assemble as regular 16 nm nanoparticles, assisted by ionic Zn. Through both in vivo and in vitro experiments, we have determined that CRT itself confers cell targeting capabilities to the construct overcoming those of V1, that are only moderate. In particular, CRT binds HeLa cells in absence of further internalization, by a route fully independent of CXCR4. Furthermore, by cytometry in THP-1 cells, we observed that the binding of the protein is preferential for dead cells over live cells, a fact that cannot be associated to a mere artefactual adsorption. These data are discussed in the context of the oligomerizing properties of CRT and the potential clinical applicability of proteins and protein materials functionalized with this novel cell surface ligand.

In Vivo Detection of Multidrug-Resistance Related Proteins in Locally Advanced Breast Cancer Using 99mTc-MIBI SPECT/CT Imaging: Correlation with Clinical Outcomes

OBJECTIVE

Neoadjuvant chemotherapy (NACT) is widely used for treating locally advanced Breast cancer (LABC). However, development of multidrug resistance (MDR) is the main underlying factor for chemoresistance. Technetium-99m methoxyisobutylisonitrile (99mTc-MIBI) is a substrate for MDR. This study aimed to analyze the relationship between expression of MDR-related proteins (P-gp and Bcl-2) and 99mTc-MIBI uptake and retention in BC tumor cells, pathologic response to NACT, disease free survival (DFS) and overall survival (OS).

METHODS

prospective analysis recruited 31 patients with LABC who received NACT between January 2019 and March 2020. 99mTc-MIBI planar and SPECT/CT imaging was conducted before and after NACT. Qualitative and quantitative analyses were performed, pre and post-NACT early and delayed lesion to non-lesion (LNL) ratios, and retention index (RI) of 99mTc-MIBI were calculated. Expression of P-gp and Bcl-2 in tumor cells was determined by immunohistochemistry.

RESULTS

Quantitively, inter-reader ICC for SPECT/CT based quantification was consistently higher than that of planar images. Post-NACT LNL ratios were significantly higher in patients with pathologic persistent disease (PPD). A change in RI between pre- and post-NACT scans demonstrated a significant association with DFS with a hazard ratio of 0.7 (95%CI: 06-1.0). Qualitatively, SPECT/CT was significantly more accurate compared to planar imaging in identifying residual viable tumor (81% compared to 57%).  Her2neu positivity and high post-operative Bcl-2 and P-gp were associated with worse DFS. A significant association was found between increased expression of post-NACT Bcl-2 and PPD, advanced tumor stage and poor OS.

CONCLUSION

99mTc-MIBI SPECT/CT based qualitative evaluation of BC response to NACT is more accurate than planar imaging. Post-NACT MIBI retention is positively correlated with P-gp and Bcl-2 expression. 99mTc-MIBI SPECT/CT may predict MDR development. High post-NACT Bcl-2 expression is significantly associated with advanced tumor stage and OS. High post-NACT P-gp expression has a worse impact on pathologic response and DFS.

Emerging Chemodynamic Nanotherapeutics for Cancer Treatment

Chemodynamic therapy (CDT) has emerged as a transformative paradigm in the realm of reactive oxygen species -mediated cancer therapies, exhibiting its potential as a sophisticated strategy for precise and effective tumor treatment. CDT primarily relies on metal ions and hydrogen peroxide to initiate Fenton or Fenton-like reactions, generating cytotoxic hydroxyl radicals. Its notable advantages in cancer treatment are demonstrated, including tumor specificity, autonomy from external triggers, and a favorable side-effect profile. Recent advancements in nanomedicine are devoted to enhancing CDT, promising a comprehensive optimization of CDT efficacy. This review systematically elucidates cutting-edge achievements in chemodynamic nanotherapeutics, exploring strategies for enhanced Fenton or Fenton-like reactions, improved tumor microenvironment modulation, and precise regulation in energy metabolism. Moreover, a detailed analysis of diverse CDT-mediated combination therapies is provided. Finally, the review concludes with a comprehensive discussion of the prospects and intrinsic challenges to the application of chemodynamic nanotherapeutics in the domain of cancer treatment.

Overcoming cancer drug-resistance calls for novel strategies targeting abnormal alternative splicing

Abnormal gene alternative splicing (AS) events are strongly associated with cancer progression. Here, we summarize AS events that contribute to the development of drug resistance and classify them into three categories: alternative cis-splicing (ACS), alternative trans-splicing (ATS), and alternative back-splicing (ABS). The regulatory mechanisms underlying AS processes through cis-acting regulatory elements and trans-acting factors are comprehensively described, and the distinct functions of spliced variants, including linear spliced variants derived from ACS, chimeric spliced variants arising from ATS, and circRNAs generated through ABS, are discussed. The identification of dysregulated spliced variants, which contribute to drug resistance and hinder effective cancer treatment, suggests that abnormal AS processes may together serve as a precise regulatory mechanism enabling drug-resistant cancer cell survival or, alternatively, represent an evolutionary pathway for cancer cells to adapt to changes in the external environment. Moreover, this review summarizes recent advancements in treatment approaches targeting AS-associated drug resistance, focusing on cis-acting regulatory elements, trans-acting factors, and specific spliced variants. Collectively, gaining an in-depth understanding of the mechanisms underlying aberrant alternative splicing events and developing strategies to target this process hold great promise for overcoming cancer drug resistance.

KIN17 functions in DNA damage repair and chemosensitivity by modulating RAD51 in hepatocellular carcinoma

The limited response of hepatocellular carcinoma (HCC) to chemotherapy drugs has always been a bottleneck in therapy. DNA damage repair is a major reason for chemoresistance. Previous studies have confirmed that KIN17 affects chemosensitivity. In this study, we examined the impact of KIN17 on chemotherapy response and DNA repair in HCC cells treated with oxaliplatin (L-OHP). We evaluated the expression and biological roles of KIN17 in HCC using bioinformatic analysis. The correlation between KIN17 and RAD51, particularly their nuclear expression levels, was evaluated using immunofluorescence, immunoblotting after nucleocytoplasmic separation in HCC cells, and immunohistochemistry of mouse xenograft tumors and human HCC tissues. The results indicated a significant increase in KIN17 expression in HCC tissues compared to normal tissues. The GSEA analysis revealed that upregulation of KIN17 was significantly associated with DNA damage repair. Knockdown of KIN17 led to increased DNA damage and reduced cellular survival after exposure to L-OHP. On the other hand, overexpression of KIN17 was linked to decreased DNA damage and improved cell survival following L-OHP treatment. Further experiments indicated that KIN17 affects the expression of RAD51, particularly in the nucleus. KIN17 plays a crucial role in influencing the sensitivity of HCC to chemotherapy by triggering the DNA repair response. Increased expression of KIN17 is associated with a poor prognosis for HCC patients, indicating that KIN17 could serve as a prognostic marker and therapeutic target for HCC.

Novel insights into the role of bisphenol A (BPA) in genomic instability

Bisphenol A (BPA) is a phenolic chemical that has been used for over 50 years in the manufacturing of polycarbonate and polyvinyl chloride plastics, and it is one of the highest volume chemicals produced worldwide. Because BPA can bind to and activate estrogen receptors, studies have mainly focused on the effect of BPA in disrupting the human endocrine and reproductive systems. However, BPA also plays a role in promoting genomic instability and has been associated with initiating carcinogenesis. For example, it has been recently shown that exposure to BPA promotes the formation of single stranded DNA gaps, which may be associated with increased genomic instability. In this review, we outline the mechanisms by which BPA works to promote genomic instability including chromosomal instability, DNA adduct formation, ROS production, and estrogen receptor (ER) activation. Moreover, we define the ways in which BPA promotes both carcinogenesis and resistance to chemotherapy, and we provide critical insights into future directions and outstanding questions in the field.

Two-pronged reversal of chemotherapy resistance by gold nanorods induced mild photothermal effect

Chemotherapy treatment outcomes are severely restricted by multidrug resistance (MDR), in which tumors develop a multiple cross-resistance toward drug involving the pump and nonpump resistance mechanisms, resulting in drug efflux and defending against drug toxicity. Herein, we constructed a pH and near infrared (NIR) light responsive nanomedicine DOX@FG based on gold nanorods (GNRs) that demonstrated the potential to improve chemotherapy outcomes by overcoming MDR. DOX@FG was constructed by conjugating folic acid (FA) and doxorubicin (DOX) derivatives onto GNRs, where the DOX derivatives possessed an acid-labile hydrazone bond. Stimulated by the acidic media in endocytic organelles, DOX@FG exhibited a responsive dissociation for the controlled release of chemotherapeutic DOX. Surprisingly, we found the mild photothermal effect elicited by GNRs under NIR irradiation simultaneously inhibited the pump and nonpump resistance mechanisms, enhancing the intracellular DOX accumulation and sensitizing the cancer cells to DOX, collectively amplify the chemotherapy efficacy and delay the MCF-7/ADR breast tumor growth. This intelligent DOX@FG nanomedicine with the potential for two-pronged reversal of MDR may provide a prospective way to encourage chemotherapy efficacy.

Sensitization of Multidrug Resistant Cancer Cells to Doxorubicin Using Ebselen by Disturbing Cellular Redox Status

Multidrug resistance (MDR) poses a significant problem in cancer treatment, often causing adverse effects during chemotherapy. Ebselen (Ebs), a synthetic organoselenium compound, affects cellular redox status in cancer cells. In the study, we observed that Ebs disrupted cellular redox balance and sensitized drug-resistant cells to doxorubicin (DOX) treatment. The combination of Ebs and DOX led to increased intracellular reactive oxygen species (ROS) levels and lipid peroxidation while decreasing the activity of thioredoxin reductase (TrxR) and cellular antioxidants in drug-resistant cells. Furthermore, this combination treatment demonstrated notable chemosensitizing effects by reducing cell viability and proliferation in MDR cells compared to DOX treatment alone. Additionally, the combination of Ebs and DOX induced DNA fragmentation and exhibited G2/M phase cell cycle arrest. Immunofluorescent analysis revealed that the Ebs and DOX combination upregulated the expression of p53 and p21, which activated the mitochondrial-dependent apoptotic pathway. The combination treatment also enhanced the upregulation of proapoptotic markers such as Bax, Caspase-3, -9, and cytochrome C, while downregulating the expression of the antiapoptotic marker Bcl-2. Therefore, the current discoveries suggest that Ebs could be employed as a drug candidate for reversing MDR in cancer cells by regulating cellular redox homeostasis.

The Antitumour Mechanisms of Carotenoids: A Comprehensive Review

Carotenoids, known for their antioxidant properties, have garnered significant attention for their potential antitumour activities. This comprehensive review aims to elucidate the diverse mechanisms by which carotenoids exert antitumour effects, focusing on both well-established and novel findings. We explore their role in inducing apoptosis, inhibiting cell cycle progression and preventing metastasis by affecting oncogenic and tumour suppressor proteins. The review also explores the pro-oxidant function of carotenoids within cancer cells. In fact, although their overall contribution to cellular antioxidant defences is well known and significant, some carotenoids can exhibit pro-oxidant effects under certain conditions and are able to elevate reactive oxygen species (ROS) levels in tumoural cells, triggering mitochondrial pathways that would lead to cell death. The final balance between their antioxidant and pro-oxidant activities depends on several factors, including the specific carotenoid, its concentration and the redox environment of the cell. Clinical trials are discussed, highlighting the conflicting results of carotenoids in cancer treatment and the importance of personalized approaches. Emerging research on rare carotenoids like bacterioruberin showcases their superior antioxidant capacity and selective cytotoxicity against aggressive cancer subtypes, such as triple-negative breast cancer. Future directions include innovative delivery systems, novel combinations and personalized treatments, aiming to enhance the therapeutic potential of carotenoids. This review highlights the promising yet complex landscape of carotenoid-based cancer therapies, calling for continued research and clinical exploration.

Epigenetic modification of ferroptosis by non-coding RNAs in cancer drug resistance

The development of drug resistance remains a major challenge in cancer treatment. Ferroptosis, a unique type of regulated cell death, plays a pivotal role in inhibiting tumour growth, presenting new opportunities in treating chemotherapeutic resistance. Accumulating studies indicate that epigenetic modifications by non-coding RNAs (ncRNA) can determine cancer cell vulnerability to ferroptosis. In this review, we first summarize the role of chemotherapeutic resistance in cancer growth/development. Then, we summarize the core molecular mechanisms of ferroptosis, its upstream epigenetic regulation, and its downstream effects on chemotherapeutic resistance. Finally, we review recent advances in understanding how ncRNAs regulate ferroptosis and from such modulate chemotherapeutic resistance. This review aims to enhance general understanding of the ncRNA-mediated epigenetic regulatory mechanisms which modulate ferroptosis, highlighting the ncRNA-ferroptosis axis as a key druggable target in overcoming chemotherapeutic resistance.

Nrf2 in human cancers: biological significance and therapeutic potential

The nuclear factor-erythroid 2-related factor 2 (Nrf2) is able to control the redox balance in the cells responding to oxidative damage and other stress signals. The Nrf2 upregulation can elevate the levels of antioxidant enzymes to support against damage and death. In spite of protective function of Nrf2 in the physiological conditions, the stimulation of Nrf2 in the cancer has been in favour of tumorigenesis. Since the dysregulation of molecular pathways and mutations/deletions are common in tumors, Nrf2 can be a promising therapeutic target. The Nrf2 overexpression can prevent cell death in tumor and by increasing the survival rate of cancer cells, ensures the carcinogenesis. Moreover, the induction of Nrf2 can promote the invasion and metastasis of tumor cells. The Nrf2 upregulation stimulates EMT to increase cancer metastasis. Furthermore, regarding the protective function of Nrf2, its stimulation triggers chemoresistance. The natural products can regulate Nrf2 in the cancer therapy and reverse drug resistance. Moreover, nanostructures can specifically target Nrf2 signaling in cancer therapy. The current review discusses the potential function of Nrf2 in the proliferation, metastasis and drug resistance. Then, the capacity of natural products and nanostructures for suppressing Nrf2-mediated cancer progression is discussed.

Polyploid cancer cells reveal signatures of chemotherapy resistance

Therapeutic resistance in cancer significantly contributes to mortality, with many patients eventually experiencing recurrence after initial treatment responses. Recent studies have identified therapy-resistant large polyploid cancer cells in patient tissues, particularly in late-stage prostate cancer, linking them to advanced disease and relapse. Here, we analyzed bone marrow aspirates from 44 advanced prostate cancer patients and found the presence of circulating tumor cells with increased genomic content (CTC-IGC) was significantly associated with poorer progression-free survival. Single cell copy number profiling of CTC-IGC displayed clonal origins with typical CTCs, suggesting complete polyploidization. Induced polyploid cancer cells from PC3 and MDA-MB-231 cell lines treated with docetaxel or cisplatin were examined through single cell DNA sequencing, RNA sequencing, and protein immunofluorescence. Novel RNA and protein markers, including HOMER1, TNFRSF9, and LRP1, were identified as linked to chemotherapy resistance. These markers were also present in a subset of patient CTCs and associated with recurrence in public gene expression data. This study highlights the prognostic significance of large polyploid tumor cells, their role in chemotherapy resistance, and their expression of markers tied to cancer relapse, offering new potential avenues for therapeutic development.

A Benzimidazole-Based N-Heterocyclic Carbene Derivative Exhibits Potent Antiproliferative and Apoptotic Effects against Colorectal Cancer

Background and Objectives: Colorectal cancer (CRC) remains a major global health issue. Although chemotherapy is the first-line treatment, its effectiveness is limited due to drug resistance developed in CRC. To overcome resistance and improve the prognosis of CRC patients, investigating new therapeutic approaches is necessary. Materials and Methods: Using human colorectal adenocarcinoma (HT29) and metastatic CRC (SW620) cell lines, the potential anticancer properties of a newly synthesized compound 1-(Isobutyl)-3-(4-methylbenzyl) benzimidazolium chloride (IMBZC) were evaluated by performing MTT cytotoxicity, cell migration, and colony formation assays, as well as by monitoring apoptosis-related protein and gene expression using Western blot and reverse transcription-quantitative polymerase chain reaction technologies. Results: Tested at various concentrations, the half-maximal inhibitory concentrations (IC50) of IMBZC on HT29 and SW620 cell growth were determined to be 22.13 µM (6.97 μg/mL) and 15.53 µM (4.89 μg/mL), respectively. IMBZC did not alter the cell growth of normal HEK293 cell lines. In addition, IMBZC inhibited cell migration and significantly decreased colony formation, suggesting its promising role in suppressing cancer metastasis. Mechanistic analyses revealed that IMBZC treatment increased the expression of pro-apoptotic proteins p53 and Bax, while decreasing the expression of anti-apoptotic proteins Bcl-2 and Bcl-xL, thus indicating the induction of apoptosis in IMBZC-treated CRC cells, compared to untreated cells. Additionally, the addition of IMBZC to conventional chemotherapeutic drugs (i.e., 5-fluorouracil, irinotecan, and oxaliplatin) resulted in an increase in the cytotoxic potential of the drugs. Conclusions: This study suggests that IMBZC has substantial anticancer effects against CRC cells through its ability to induce apoptosis, inhibit cancer cell migration and colony formation, and enhance the cytotoxic effects of conventional chemotherapeutic drugs. These findings indicate that IMBZC could be a promising chemotherapeutic drug for the treatment of CRC. Further research should be conducted using in vivo models to confirm the anti-CRC activities of IMBZC.

Functionalized Magnetic Fe3O4 Nanoparticles for Targeted Methotrexate Delivery in Ovarian Cancer Therapy

Magnetic Fe3O4 nanoparticles (MNPs) functionalized with (3-aminopropylo)trietoksysilan (APTES) or N-carboxymethylchitosan (CMC) were proposed as nanocarriers of methotrexate (MTX) to target ovarian cancer cell lines. The successful functionalization of the obtained nanostructures was confirmed by FT-IR spectroscopy. The nanoparticles were characterized by transmission electron spectroscopy (TEM) and dynamic light scattering (DLS) techniques. Their potential zeta, magnetization, and hyperthermic properties were also explored. MTX was conjugated with the nanocarriers by ionic bonds or by amide bonds. The drug release kinetics were examined at different pH and temperatures. The MTT assay showed no toxicity of the MNPs[APTES] and MNPs[CMC]. Finally, the cytotoxicity of the nanostructures with MTX attached towards the ovarian cancer cells was measured. The sensitivity and resistance to methotrexate was determined in simplistic 2D and spheroid 3D conditions. The cytotoxicity tests of the tested nanostructures showed similar values for inhibiting the proliferation of ovarian cancer cells as methotrexate in its free form. Conjugating MTX with nanoparticles allows the drug to be directed to the target site using an external magnetic field, reducing overall toxicity. Combining this approach with hyperthermia could enhance the therapeutic effect in vivo compared to free MTX, though further research on advanced 3D models is needed.

Palladium(II)-Indenyl Complexes Bearing N-Heterocyclic Carbene (NHC) Ligands as Potent and Selective Metallodrugs toward High-Grade Serous Ovarian Cancer Models

In this study, we synthesized novel Pd(II)-indenyl complexes using various N-heterocyclic carbene (NHC) ligands, including chelating NHC-picolyl, NHC-thioether, and diNHC ligands, and two monodentate NHCs. Transmetalation reactions between a Pd(II)-indenyl precursor and silver-NHC complexes were generally employed, except for chelating diNHC derivatives, which required direct reaction with bisimidazolium salts and potassium carbonate. Characterization included NMR, HRMS analysis, and single-crystal X-ray diffraction. In vitro on five ovarian cancer cell lines showed notable cytotoxicity, with IC50 values in the micro- and submicromolar range. Some compounds exhibited intriguing selectivity for cancer cells due to higher tumor cell uptake. Mechanistic studies revealed that monodentate NHCs induced mitochondrial damage while chelating ligands caused DNA damage. One chelating NHC-picolyl ligand showed promising cytotoxicity and selectivity in high-grade serous ovarian cancer models, supporting its consideration for preclinical study.

Tricarboxylic Acid Cycle Relationships with Non-Metabolic Processes: A Short Story with DNA Repair and Its Consequences on Cancer Therapy Resistance

Metabolic changes involving the tricarboxylic acid (TCA) cycle have been linked to different non-metabolic cell processes. Among them, apart from cancer and immunity, emerges the DNA damage response (DDR) and specifically DNA damage repair. The oncometabolites succinate, fumarate and 2-hydroxyglutarate (2HG) increase reactive oxygen species levels and create pseudohypoxia conditions that induce DNA damage and/or inhibit DNA repair. Additionally, by influencing DDR modulation, they establish direct relationships with DNA repair on at least four different pathways. The AlkB pathway deals with the removal of N-alkylation DNA and RNA damage that is inhibited by fumarate and 2HG. The MGMT pathway acts in the removal of O-alkylation DNA damage, and it is inhibited by the silencing of the MGMT gene promoter by 2HG and succinate. The other two pathways deal with the repair of double-strand breaks (DSBs) but with opposite effects: the FH pathway, which uses fumarate to help with the repair of this damage, and the chromatin remodeling pathway, in which oncometabolites inhibit its repair by impairing the homologous recombination repair (HRR) system. Since oncometabolites inhibit DNA repair, their removal from tumor cells will not always generate a positive response in cancer therapy. In fact, their presence contributes to longer survival and/or sensitization against tumor therapy in some cancer patients.

Anticancer Activity of Benzo[a]phenoxazine Compounds Promoting Lysosomal Dysfunction

Specific cancer therapy remains a problem to be solved. Breast and colorectal cancer are among the cancers with the highest prevalence and mortality rates. Although there are some therapeutic options, there are still few effective agents for those cancers, which constitutes a clinical problem that requires further research efforts. Lysosomes play an important role in cancer cells' survival, and targeting lysosomes has gained increased interest. In recent years, our team has been synthetizing and testing novel benzo[a]phenoxazine derivatives, as they have been shown to possess potent pharmacological activities. Here, we investigated the anticancer activity of three of the most potent derivatives from our library, C9, A36, and A42, on colorectal- and breast-cancer-derived cell lines, and compared this with the effect on non-neoplastic cell lines. We observed that the three compounds were selective for the cancer cells, namely the RKO colorectal cancer cell line and the MCF7 breast cancer cell line. In both models, the compounds reduced cell proliferation, cell survival, and cell migration, accumulated on the lysosome, and induced cell death accompanied by lysosomal membrane permeabilization (LMP), increasing the intracellular pH and ROS accumulation. Our results demonstrated that these compounds specifically target lysosomes from cancer cells, making them promising candidates as LMP inducers for cancer therapy.

Identification of Clinical Value and Biological Effects of XIRP2 Mutation in Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is a prevalent malignant digestive tumor. Numerous genetic mutations have been documented in HCC, yet the clinical significance of these mutations remains largely unexplored. The objective of this study is to ascertain the clinical value and biological effects of xin actin binding repeat containing 2 (XIRP2) mutation in HCC. The gene mutation landscape of HCC was examined using data from the Cancer Genome Atlas and the International Cancer Genome Consortium databases. The prognostic significance of the XIRP2 mutation was assessed through KM plot analysis. The association between drug sensitivity and the XIRP2 mutation was investigated using the TIDE algorithm and CCK-8 experiments. The biological effects of the XIRP2 mutation were evaluated through qRT-PCR, protein stability experiments, and relevant biological experiments. The XIRP2 mutation is one of the high-frequency mutations in HCC, and is associated with poor prognosis. A total of 72 differentially expressed genes (DEGs) were observed in HCC tissues with the XIRP2 mutation as compared to those with the XIRP2 wildtype, and these DEGs were closely related to ion metabolic processes. The XIRP2 mutation was linked to alterations in the sensitivity of fludarabine, oxaliplatin, WEHI-539, and LCL-161. CCK-8 assays demonstrated that HCC cells carrying the XIRP2 mutation exhibited increased resistance to fludarabine and oxaliplatin, but enhanced sensitivity to WEHI-539 and LCL-161 as compared with those HCC cells with the XIRP2 wildtype. The XIRP2 mutation was found to have no impact on the mRNA levels of XIRP2 in tissues and cells, but it did enhance the stability of the XIRP2 protein. Mechanically, the inhibition of XIRP2 resulted in a significant increase in sensitivity to oxaliplatin through an elevation in zinc ions and a calcium ion overload. In conclusion, the XIRP2 mutation holds potential as a biomarker for predicting the prognosis and drug sensitivity of HCC and serves as a therapeutic target to enhance the efficacy of oxaliplatin.

Surface Engineering of Magnetic Iron Oxide Nanoparticles for Breast Cancer Diagnostics and Drug Delivery

Data published in 2020 by the International Agency for Research on Cancer (IARC) of the World Health Organization show that breast cancer (BC) has become the most common cancer globally, affecting more than 2 million women each year. The complex tumor microenvironment, drug resistance, metastasis, and poor prognosis constitute the primary challenges in the current diagnosis and treatment of BC. Magnetic iron oxide nanoparticles (MIONPs) have emerged as a promising nanoplatform for diagnostic tumor imaging as well as therapeutic drug-targeted delivery due to their unique physicochemical properties. The extensive surface engineering has given rise to multifunctionalized MIONPs. In this review, the latest advancements in surface modification strategies of MIONPs over the past five years are summarized and categorized as constrast agents and drug delivery platforms. Additionally, the remaining challenges and future prospects of MIONPs-based targeted delivery are discussed.

Discovery of oral chemotherapeutic reversal agents for treating multidrug resistance cancer

The major limitation of cancer treatment is multidrug resistance (MDR), which leads to the inactivation of chemotherapeutic drugs and greater than 90% mortality. To solve this ordeal, we applied ligand-based drug design and bioiosteric replacement strategy from an indazole to a pyrazole ring to discover compounds 27 and 43 with good potential for reversing drug resistance in combination with paclitaxel, and their reversal fold values were 53.2 and 51.0 at 5 μM, respectively, against an MDR cancer cell line (KBvin). Based on the PK profile results, we selected compound 43 with a longer half-life for mechanistic and animal experiments. Combination treatment with compound 43 and paclitaxel-induced apoptosis and enhanced subG1 by decreasing mitochondrial membrane potential in KBvin cells. In addition, 43 also inhibited P-gp function by interfering with ATPase activity. Meanwhile, cotreatment with compound 43 and paclitaxel significantly suppressed tumor growth (TGI = 55.5%) at a dose of 200 mg/kg (PO) in a xenograft model and showed no obvious liver or kidney toxicity by H&E staining. Overall, compound 43 may serve as a safe and effective oral resistance reversal chemotherapeutic agent.

Cost-effectiveness of pembrolizumab plus chemotherapy vs. chemotherapy as first-line treatment for advanced biliary tract cancer in China and the US

Background: Pembrolizumab is a potentially valuable treatment. However, patients, doctors, and healthcare decision-makers are uncertain about its cost-effectiveness and an appropriate pricing for this new therapy. This study aims to appraise the cost-effectiveness of pembrolizumab as a first-line treatment for advanced biliary tract cancer (BTC) patients in China and the United States (US). Methods: A Markov model was constructed from the perspectives of healthcare systems in both China and the US for pharmacoeconomic evaluation. Patient baseline characteristics and key clinical data were sourced from the KEYNOTE-966 trial (ClinicalTrials.gov, NCT04003636). Costs and utilities were collected from drug cost websites and published literature. Cumulative costs (in USD), life years (LYs), quality-adjusted life years (QALYs), and incremental cost-effectiveness ratios (ICERs) were measured and compared. Price simulations were conducted under given willingness-to-pay (WTP) thresholds to provide pricing scheme references. The model's robustness was analyzed through one-way sensitivity analysis and probabilistic sensitivity analysis. Results: Basic data analysis illustrates that pembrolizumab ($2662.41/100 mg) in combination with chemotherapy regimen was not cost-effective relative to chemotherapy regimens at the WTP threshold of $38,201.19 in China, and the additional cost relative to chemotherapy regimens was $77,114.94 (ICER $556,689.47/QALY) while increasing 0.14 QALYs. Pembrolizumab ($54.71/1 mg) also increased efficacy by 0.14 QALYs in the US, but remained also not cost-effective at the US WTP threshold of $229,044, and the total cost increased by $160,425.24 (ICER $1,109,462.92/QALY). Conclusion: Compared with chemotherapy, pembrolizumab plus chemotherapy reduces the disease of burden. However, at its current price, it may not be a cost-effective treatment for advanced BTC in both China and the US. This study can aid decision-makers in making optimal choices.