ABC transporters affects tumor immune microenvironment to regulate cancer immunotherapy and multidrug resistance

Successful targeting of multidrug-resistant tumors with bispecific antibodies

Multidrug resistance (MDR) hinders efficacious cancer chemotherapy. Overexpression of the P-glycoprotein (P-gp) efflux pump (EP) on cancer cells is a primary cause of MDR since it expels numerous anticancer drugs. Small molecule intracellular P-gp antagonists have been investigated clinically to redress MDR but have failed primarily due to adverse effects on P-gp in normal tissue. We used a new approach to counteract P-gp with bispecific antibodies (BsAbs) that simultaneously bound P-gp and CD47 in cis on MDR cells but not normal tissue. Affinities of the individual arms of the BsAbs were low enough to minimize normal tissue binding, but, when the two targets were co-located on MDR cancer cells, both arms of the BsAb engaged with effective avidity. Proof-of-concept was shown in three different MDR xenograft tumor models with a non-humanized chimeric BsAb (targeting P-gp and CD47) that potently restored tumor sensitivity to paclitaxel. Fully humanized variants were successfully developed and characterized. Significant anti-tumor efficacy was observed with the BsAbs both when combined with paclitaxel and as single agents in the absence of paclitaxel. Treatment of MDR cancers with BsAbs using this novel approach has several distinct advantages over prior efforts with small molecule antagonists, including 1) invoking a direct immune attack on the tumors, 2) multimodal mechanisms of action, 3) tumor-specific targeting (with reduced toxicity to normal tissue), and 4) broad applicability as single agents and compatibility with other therapeutics.

Serum-derived extracellular vesicles mediate acquired multidrug resistance of MCF-7 breast cancer cells induced by chemotherapeutic drugs

Multidrug resistance (MDR) in tumor cells presents a significant challenge in cancer therapy. This study investigates the role of serum-derived extracellular vesicles (EVs) in mediating MDR during chemotherapeutic exposure. The findings indicate that short- or long-term co-incubation of doxorubicin (Dox)-pretreated serum derived EVs (EVs(S-PT)) caused drug-sensitive MCF-7 breast cancer cells to develop a MDR phenotype. In addition, serum EVs contain a high concentration of unglycosylated P-glycoprotein (P-gp). Chemotherapy treatment of tumor patients or exposure to chemotherapeutic drugs in vitro activates serum glycosyltransferases, inducing glycosylation of EVs P-gp and giving it drug-pumping activity. Furthermore, damage caused by Dox to the vascular endothelial barrier facilitates the crossing of serum EVs into the tumor microenvironment. These EVs are then taken up by tumor cells, providing them with access to a significant quantity of glycosylated P-gp proteins that possess transporter activity and the ability to evade degradation by the ubiquitin proteasome system. The results indicate that EVs(S-PT) transfers glycosylated P-gp across the damaged vascular endothelial barrier into MCF-7 cells and that these glycosylated P-gp remain intracellular for a long period of time, inducing MDR in the cells. Our study highlights a novel mechanism of acquired MDR and provides a potential avenue for therapeutic interventions targeting the serum EVs pathway in cancer therapy.

Interactions between radiotherapy resistance mechanisms and the tumor microenvironment

BACKGROUND

Resistance to radiotherapy (RT) presents a significant clinical challenge in management of cancer. Recent evidence points to specific mechanisms of resistance within the tumor microenvironment (TME), which we aim to discuss, with the aim of overcoming the clinical challenge.

METHODS

We performed the narrative review using PubMed and Web of Science databases to identify studies that reported the regulative network and treatments of RT resistance from TME perspectives.

RESULTS

RT significantly changes the immune TME of cancers, which is closely appearing to play a key role in RT resistance (RTR) by modulating immune cell infiltration and function. Various phenotypes are involved in the development of RTR, such as autophagy, senescence, oxidative stress, cell polarization, ceramide metabolism, and angiogenesis in the TME. Key genes and pathways are also implicated in RTR, including immune and inflammatory cytokines, TGF-β, P53, the NF-κB pathway, the cGAS/STING pathway, the ERK and AKT pathway, and the STAT pathway. Based on the mechanism of RTR in the TME, many proposed routes to overcome RTR, several specifically target the TME including targeting fibroblast activation protein, exosomes management, nanomedicine, and immunotherapy. Many challenges in RT resistance still need to be further explored with emerging investigative methods, such as artificial intelligence, genetic technologies, and bioengineering.

CONCLUSIONS

The complex interactions between RT and TME significantly affect the efficiency of RT. Novel approaches to overcome this clinical difficulty are promising, which needs future work to further explore and identify better treatment strategies.

Integrated pan-cancer analysis revealed therapeutic targets in the ABC transporter protein family

Next-generation sequencing technology enables uniform and impartial assessment of cancer diagnoses and prognosis. However, such studies are mostly type-specific, and capturing shared genomic abnormalities responsible for neoplastic transformation and progression is a challenging task. Pan-cancer analysis offers insights into the shared and unique molecular mechanisms driving cancer. We conducted an integrated gene-expression analysis using 10,629 samples from 30 distinct cancer types characterized by The Cancer Genome Atlas (TCGA). A gene co-expression network was constructed and genes overlapping between the selected modules and Differentially Expressed Genes (DEGs) were designated as genes of interest. Following a comprehensive literature review, ATP binding cassette subfamily A member 10 (ABCA10) and ATP binding cassette subfamily B member 5 (ABCB5) were selected as key candidates for downstream analysis due to the absence of systematic pan-cancer analysis of these genes. This study presents a unique contribution as the first comprehensive pan-cancer analysis of ABCA10 and ABCB5, highlighting their roles in tumor biology and clinical outcomes. We employed a variety of bioinformatics tools to explore the role of these genes across different tumors. Our research demonstrated that ABCA10 shows reduced expression, while ABCB5 displays variable expression patterns across tumors, indicating their opposing roles and flexible functions in pan-cancer. In many cancer patients, these expression patterns are correlated with worse survival outcomes. Furthermore, immunotherapy responses and immune infiltration across a variety of tumor types are associated with the expression levels of both ABCA10 and ABCB5. These results imply that ABCA10 and ABCB5 could serve as valuable predictive markers and potential therapeutic targets across various cancers.

ML210 Antagonizes ABCB1- Not ABCG2-Mediated Multidrug Resistance in Colorectal Cancer

Objectives: ABCB1-mediated multidrug resistance (MDR) compromises chemotherapy efficacy in colorectal cancer (CRC). Despite decades of research, no selective ABCB1 inhibitor has achieved clinical success. This study investigates ML210 as a novel ABCB1-specific inhibitor to reverse ABCB1-driven MDR. Methods: Cytotoxicity assays (MTT) were performed on ABCB1-overexpressing HCT-8/V and ABCG2-overexpressing S1-M1-80 CRC cells. Drug accumulation (doxorubicin/mitoxantrone) was quantified via flow cytometry, and cell cycle effects were analyzed using propidium iodide staining. Molecular docking utilized the ABCB1 crystal structure. Results: ML210 selectively reversed ABCB1-mediated resistance to doxorubicin and vincristine in HCT-8/V cells, enhancing intracellular drug accumulation without affecting ABCG2 activity. It induced cell cycle arrest in ABCB1-overexpressing cells and did not alter ABCB1 protein expression. Molecular docking revealed stable binding of ML210 within the ABCB1 substrate pocket through hydrophobic interactions and hydrogen bonding. Conclusions: ML210 is a selective ABCB1 inhibitor that circumvents MDR via direct transport blockade, offering a targeted strategy against ABCB1-mediated chemoresistance in CRC. Its specificity for ABCB1 over ABCG2 highlights potential clinical advantages.

A comprehensive review on overcoming the multifaceted challenge of cancer multidrug resistance: The emerging role of mesoporous silica nanoparticles

Multidrug resistance (MDR) is a significant challenge in tumor treatment, severely reducing the effectiveness of anticancer drugs and contributing to high mortality rates. This article overviews the various factors involved in the development of MDR, such as changes in drug targets, increased DNA repair mechanisms, and the impact of the tumor microenvironment. It also emphasizes the potential of mesoporous silica nanoparticles (MSNs) as a drug delivery system to combat MDR. With their unique characteristics-such as a high surface area, adjustable pore sizes, and the ability to be functionalized for targeted delivery-MSNs serve as excellent carriers for the simultaneous delivery of chemotherapeutics and siRNAs aimed at reversing resistance pathways. The paper focuses on innovative methods using MSNs for direct intranuclear delivery of their cargos to overcome efflux barrier and improve the effectiveness of combination therapies. This review highlights a promising approach for enhancing cancer treatment outcomes by integrating advanced nanotechnology with traditional therapies, addressing the ongoing challenge of MDR in oncology.

Unveiling drug resistance pathways in high-grade serous ovarian cancer(HGSOC): recent advances and future perspectives

High-Grade Serous Ovarian Carcinoma (HGSOC) represents the most prevalent and lethal subtype of ovarian cancer, with approximately 225,000 new cases reported globally each year and a five-year survival rate of merely 49.1%. The clinical management of HGSOC encounters substantial challenges, primarily attributable to its intricate drug resistance mechanisms, which involve multiple biological processes, including tumor cell heterogeneity, microenvironment remodeling, gene mutations, and drug efflux. This study systematically reviews the most recent advancements in HGSOC drug resistance research, concentrating on the molecular biological foundations of resistance mechanisms, innovative detection strategies, and potential therapeutic approaches. The research indicates that HGSOC drug resistance constitutes a complex process characterized by multifactorial interactions, involving aberrant cell signaling pathways, dynamic alterations in the tumor microenvironment, and specific expressions of molecular markers. In this review, we systematically analyzed and investigated the intricate biological behaviors associated with HGSOC drug resistance, which not only enhances the understanding of disease progression but also provides essential theoretical foundations for the development of more precise and effective targeted therapies. This review firstly illustrated the detailed drug resistance cellular and molecular mechanisms underlying HGSOC chemotherapy, which can pave the way for future studies in HGSOC drug resistance practices.

Combination Therapy for Overcoming Multidrug Resistance in Breast Cancer Through Hedgehog Signaling Pathway Regulation

Background/Objectives: The ineffective delivery of drugs into tumors and the existence of multidrug resistance (MDR) are the primary causes of chemotherapy failure. Downregulation of the Sonic Hedgehog (Shh) pathway has been shown to reduce P-glycoprotein (P-gp) expression on cell membranes and to resist MDR. Methods: In this study, we combine cyclopamine (CYP, a potent Shh antagonist) with paclitaxel (PTX, an antitumor drug that can produce MDR) in a nano-drug delivery system (CYP NP and PTX NP) for the treatment of drug-resistant breast cancer. Nanoparticles were characterized for size, zeta potential, and encapsulation efficiency. P-gp expression, nanoparticle accumulation, cytotoxicity, and apoptosis were evaluated in MCF-7 and MCF-7/Adr cells. Penetration ability was assessed using 3D multicellular tumor spheroids. Antitumor efficacy and nanoparticle biodistribution were validated in MCF-7/Adr-bearing nude mice models. Results: Our engineered CYP nanoparticles (~200 nm) demonstrated prolonged intratumoral retention, enabling sustained Shh pathway inhibition and P-gp functional suppression. This size-optimized formulation created a favorable tumor microenvironment for the smaller PTX nanoparticles (~30 nm), facilitating deeper tumor penetration and enhanced cellular uptake. Meanwhile, by down-regulating P-gp expression, CYP NPs could convert drug-resistant cells to PTX-sensitive cells in both cytotoxicity and apoptosis induction through the Shh pathway. The combination of CYP NP and PTX NP augmented the antitumor effects in MCF-7/Adr-bearing nude mice models. Conclusions: The CYP NP and PTX NP combination offers a new therapeutic strategy in cancer treatment.

The human ABCG2 transporter engages three gates to control multidrug extrusion

The human ABCG2 transporter plays roles in physiological detoxification across barriers and in anticancer multidrug resistance. The translocation pathway for drug extrusion and its gating mechanism remains elusive. Here, we demonstrate that the ABCG2 multidrug transporter holds two cavities that are delineated by three regulatory gates, indicating a substrate translocation channel. Drugs are trapped in the central cavity after entering through the pivotal intracellular entry gate. This flexible cavity is surrounded by a cluster of three highly conserved phenylalanines. Their aromatic side chains enact a "clamp-push-seal" motion to ensure unidirectional substrate movement. The unique residues T435 and N436 act as critical selectors for ligands, determining the broad substrate specificity. The upper cavity is covered by the lid architecture, constituting the final gate before multidrug extrusion. This work unravels deep mechanistic details on how the translocation channel utilizes pivotal gating steps, including the sequence of events that drive ABCG2-mediated multidrug efflux.

Overcoming cancer therapy resistance: From drug innovation to therapeutics

One of the major limitations of cancer therapy is the emergence of drug resistance. This review amis to provide a focused analysis of the multifactorial mechanisms underlying therapy resistance,with an emphasis on actionable insights for developing novel therapeutic strategies. It concisely outlines key factors contributing to therapy resistance, including drug delivery barriers, cancer stem cells (CSCs), epithelial-mesenchymal transition (EMT), cancer heterogeneity, tumor microenvironment (TME), genetic mutations, and alterlations in gene expression. Additionally, we explore how tumors evade targeted therapies through pathway-specific mechanisms that restore disrupted signaling pathways. The review critically evaluates innovative strategies designed to sensitize resistant tumor cells, such as targeted protein dedgradation, antibody-drug conjugates, structure-based drug design, allosteric drugs, multitarget drugs, nanomedicine and others We also highlight the importance of understanding the pharmacological actions of these agents and their integration into treatment regimens. By synthesizing current knowledge and identifying gaps in our understanding, this review aims to guide future research and improve patient outcomes in cancer therapy.

Rational design of peptides to overcome drug resistance by metabolic regulation

Chemotherapy is widely used clinically, however, its efficacy is often compromised by the development of drug resistance, which arises from prolonged administration of drugs or other stimuli. One of the driven causes of drug resistance in tumors or bacterial infections is metabolic reprogramming, which alters mitochondrial metabolism, disrupts metabolic pathways and causes ion imbalance. Bioactive peptide materials, due to their biocompatibility, diverse bioactivities, customizable sequences, and ease of modification, have shown promise in overcoming drug resistance. This review provides an in-depth analysis of metabolic reprogramming and associated microenvironmental changes that contribute to drug resistance in common tumors and bacterial infections, suggesting potential therapeutic targets. Additionally, we explore peptide-based materials for regulating metabolism and their potential synergic effect with other therapies, highlighting the mechanisms by which these peptides reverse drug resistance. Finally, we discuss future perspectives and the clinical challenges in peptide-based treatments, aiming to offer insights for overcoming drug-resistant diseases.

SALL4/ABCB6 Axis Suppresses Ferroptosis in Colon Cancer by Mediating Mitophagy

According to reports, the inhibition of ferroptosis is an essential culprit of malignant progression in various tumors, including colon cancer (CC). However, the relevant study on the regulatory mechanism of CC ferroptosis is sparse. This project was designed to identify the key genes modulating CC ferroptosis as well as specific mechanisms. Based on The Cancer Genome Atlas (TCGA)-CC mRNA expression data and immunohistochemistry assay, we analyzed the expression of ABCB6 and SALL4 in CC tissue. The HTFtarget was employed to predict the binding sites. The expression of ABCB6 and SALL4 in CC cells was analyzed by quantitative polymerase chain reaction, and the interaction between ABCB6 and SALL4 was verified by dual-luciferase and chromatin immunoprecipitation experiments. Cell viability was tested by cell counting kit-8 and colony formation assay. The malondialdehyde (MDA), Fe2+ content, and lipid reactive oxygen species (ROS) levels were examined by utilizing the corresponding reagent kits. The protein expression of ABCB6, SALL4, GPX4, GCLC, and SLC3A2 were determined via western blot. High expression of ABCB6 was detected in CC. ABCB6 overexpression suppressed ferroptosis and dramatically declined the levels of MDA, lipid ROS, and Fe2+ in cells. Furthermore, it induced mitochondrial membrane potential dysfunction and substantially suppressed the fluorescence intensity of GFP-LC3, which in turn promoted the expression of GPX4, GCLC, and SLC3A2 proteins and prevented CC cell ferroptosis. The cell rescue experiment verified that SALL4 initiated ABCB6 activation to mediate mitophagy and prevent ferroptosis in CC cells. The findings evidenced that the SALL4/ABCB6 axis suppresses mitophagy to hinder ferroptosis in CC. The mitophagy pathway may be essential for ABCB6 to regulate ferroptosis in CC.

The impact of the ATP-binding cassette (ABC) transporter family on multidrug resistance in head and neck tumors

The ATP-binding cassette (ABC) transporter family is among the largest protein superfamilies, consisting of seven subfamilies, and plays an important role in various physiological processes and in the clinical manifestations of many diseases. The early clinical signs of head and neck cancer (HNC) are often subtle, resulting in most patients being diagnosed at more advanced stages. This late diagnosis adversely affects tumor treatment, and the resistance of certain tumors to chemotherapy further poses significant challenges for clinical management. Several previous studies have indicated a correlation between the ABC protein family and multidrug resistance (MDR) in tumors. This article offers a thorough review of the subfamilies, structures, functions, and roles of ABC transporters in MDR related to head and neck tumors, with the aim of providing insights and recommendations for overcoming MDR in this context.

Recent progress in the development of peptide-drug conjugates (PDCs) for cancer therapy

Peptide-drug conjugates (PDCs) are emerging therapeutic agents composed of peptides, linkers, and payloads, which possess favorable targeting capability and can deliver enough payloads to the tumor sites with minimized impact on healthy tissues. However, only a few PDCs have been approved for clinical use so far. To advance the research on PDCs, this review summarizes the approved PDCs, and PDCs in clinical and preclinical stages based on the payload types. Additionally, the biological activity and pharmacokinetic properties of preclinical PDCs are detailedly described. Lastly, the challenges and future development directions of PDCs are discussed. This review aims to inspire insights into the development of PDCs for cancer treatment.

Bioinformatic characterization of STING expression in hematological malignancies reveals association with prognosis and anti-tumor immunity

Introduction

Stimulator of interferon response cGAMP interactor (STING) is essential for both innate and adaptive immunity. However, a comprehensive molecular characterization of STING expression across hematological malignancies is lacking.

Methods

In this study, the pan-blood-cancer landscape related to STING expression was identified using the GTEx, CCLE, Hemap, and TCGA databases, and the potential value for predicting prognosis was investigated. The relationship between STING expression and immune cell enrichment was assessed in the Hemap database. Moreover, the value of STING in predicting the efficacy of immunotherapy was validated using tumor immune dysfunction and exclusion (TIDE) biomarkers and real-world immunotherapy datasets.

Results and Discussion

STING was found to be relatively highly expressed in acute myeloid leukemia (AML) and chronic myeloid leukemia, with higher STING expression correlated with poorer prognosis in AML. STING expression was positively correlated with immune-related pathways such as IFN-gamma response, IFN-alpha response, and inflammatory response. Cytolytic score and STING expression were positively correlated in some hematological tumors, especially chronic lymphocytic leukemia and mantle cell lymphoma. Interestingly, STING expression was negatively correlated with TIDE biomarkers in AML, suggesting that AML patients with a high STING expression level may benefit from immunologic treatment. Our findings contribute a molecular characterization of STING across hematological malignancies, facilitating the development of individualized prognosis and treatment strategies.

Core-Shell Nanoparticles with Sequential Drug Release Depleting Cholesterol for Reverse Tumor Multidrug Resistance

Multidrug resistance (MDR) facilitates tumor recurrence and metastasis, which has become a main cause of chemotherapy failure in clinical. However, the current therapeutic effects against MDR remain unsatisfactory, mainly hampered by the rigid structure of drug-resistant cell membranes and the uncontrolled drug release. In this study, based on a sequential drug release strategy, we engineered a core-shell nanoparticle (DOX-M@CaP@ATV@HA) depleting cholesterol for reverse tumor MDR. DOX-M@CaP@ATV@HA could accurately target tumor cells due to the active targetability of hyaluronic acid (HA) toward CD44 receptors. The calcium phosphate (CaP) shell was cleaved in the lysosomal acidic environment so that the cholesterol-lowering drug atorvastatin (ATV) was rapidly released to diminish cholesterol and P-glycoprotein (P-gp) level on the membrane, thereby boosting tumor cell drug uptake. Next, doxorubicin (DOX) was gradually released from the hydrophobic core of the mPEG-DSPE micelle, inflicting irreversible DNA damage and triggering apoptosis. The nanosystem was proven both in vitro and in vivo to reverse MDR effectively and exhibited a remarkable therapeutic efficacy on drug-resistant tumors with high biosafety. In conclusion, DOX-M@CaP@ATV@HA effectively reverses MDR via cholesterol depletion, which provides an innovative strategy for tumor MDR treatment.

Lipid-encapsulated gold nanoparticles: an advanced strategy for attenuating the inflammatory response in SARS-CoV-2 infection

BACKGROUND

Nanodrugs play a crucial role in biomedical applications by enhancing drug delivery. To address safety and toxicity concerns associated with nanoparticles, lipid-nanocarrier-based drug delivery systems have emerged as a promising approach for developing next-generation smart nanomedicines. Ginseng has traditionally been used for various therapeutic purposes, including antiviral activity. This study aimed to prepare a biocompatible and therapeutically potent Korean ginseng nanoemulsion (KGS-NE) using ginseng seed oil (GSO), optimize its encapsulation and drug delivery efficiency, and evaluate its antiviral activity.

RESULTS

Various techniques were utilized to confirm the KGS-NE formation. Energy-dispersive X-ray spectroscopy identified gold nanoparticles with the highest Au peak at 2.1 keV. Selected area diffraction patterns revealed crystallographic structures. FT-IR spectrometry detected functional groups, with peaks at 2922.09 cm-1 (alkene C-H stretching), 1740.24 cm-1 (aldehyde C=O stretching), and 1098.07 cm-1 (C-O stretching in secondary alcohol). Storage stability studies showed that KGS-NE maintained its size and stability for 6 months at 4 °C. The KGS-NE exhibited a dose-dependent suppression of HCoV-OC43 viral replication in Vero E6 cells. RNA sequencing analysis unveiled differentially expressed genes (DEGs) specifically involved in the ABC transporters signaling pathway. KGS-NE oral administration facilitated the recovery of mice induced with the receptor binding domain (RBD) of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike protein, as confirmed by inflammatory markers expression in lung tissue. In the Syrian hamster infected with the SARS-CoV-2 model, the lungs dissected showed enlarged morphology and induced inflammatory cytokines. This effect was mitigated with KGS-NE oral administration, as observed through H&E and qRT-PCR analysis. Biochemical analysis at various oral administration concentrations demonstrated that KGS-NE had no adverse effects on the kidney and liver.

CONCLUSIONS

Our findings strongly suggest that oral administering KGS-NE in mice and Syrian hamster models has the potential to effectively mitigate lung inflammation against coronavirus. This indicates a promising new strategy for developing the antiviral nano-agent against SARS-CoV-2.

Genetic Risk Profiling Reveals Altered Glycosyltransferase Expression as a Predictor for Patient Outcome in Neuroblastoma

Background/Objectives: Neuroblastoma is a highly aggressive pediatric cancer that arises from immature nerve cells and exhibits a broad spectrum of clinical presentations. While low- and intermediate-risk neuroblastomas often have favorable outcomes, high-risk neuroblastomas are associated with poor prognosis and significant treatment challenges. The complex genetic networks driving these high-risk cases remain poorly understood. This study aims to investigate differences in gene expression patterns that may contribute to disease outcomes. Methods: We employed an in silico approach to analyze a cohort of 493 neuroblastoma tumor samples that underwent mRNA sequencing (GSE49711). This dataset was reanalyzed in depth with a non-hypothesis-driven approach to identify the expression patterns and regulatory mechanisms associated with a poor prognosis. Results: By exploring global gene expression and the integration of clinical parameters, we stratified the samples into two groups with highly distinct gene expression profiles. MYCN amplification emerged as a major driver not only of poor prognosis but also of specific gene regulatory patterns. Notably, tumors with MYCN amplification exhibited the strong regulation of immune response genes and less immune infiltration, suggesting potential immune evasion. However, while we observed only minor changes in immune checkpoint expression, there was a strong modulation of glycosyltransferase genes in MYCN-amplified tumors. Using this information, we were able to construct a risk profile based on 12 glycosylation-related genes, which correlates with the survival outcomes of neuroblastoma patients. Conclusions: This study highlights the role of MYCN amplification in driving a poor prognosis in neuroblastoma through the regulation of immune response and glycosylation-related genes. Based on this finding, we developed a genetic risk profile that correlates with survival outcomes in neuroblastoma patients.

Ganoderma lucidum extract reverses multidrug resistance in breast cancer cells through inhibiting ATPase activity of the P-glycoprotein via MAPK/ERK signaling pathway

Breast cancer represents a persistent global health challenge, with multidrug resistance (MDR) posing a significant obstacle to effective treatment. In this study, we investigate the potential of Ganoderma lucidum extract (GLE) in reversing MDR in breast cancer and delve into the underlying mechanisms. We establish a robust in vitro 3D model of breast cancer with acquired MDR induced by paclitaxel. Utilizing the CCK-8 method, we assess the impact of GLE on cytotoxic drug sensitivity to determine its in vitro MDR reversal activity. Our results reveal that GLE enhances the toxicity of paclitaxel in breast cancer cells by inhibiting the ATPase activity of P-glycoprotein (P-gp) and increasing the intracellular and extracellular excretion of P-gp substrates, all without significantly altering P-gp protein expression. Additionally, GLE inhibits the phosphorylation of ERK1/2, suggesting that the enhanced sensitivity of breast cancer cells to paclitaxel by GLE is associated with the MAPK pathway. These findings indicate that GLE may inhibit P-gp-mediated drug efflux via the MAPK pathway, thus effectively overcoming paclitaxel resistance in breast cancer. This study provides valuable insights into the potential clinical applications of GLE in reversing multidrug resistance, offering hope for improved breast cancer treatment strategies.

Correlation Between Gastroesophageal Reflux Disease and Small Intestinal Bacterial Overgrowth: Analysis of Intestinal Microbiome and Metabolic Characteristics

Background

Our study examines the relationship between gastroesophageal reflux disease (GERD) and small intestinal bacterial overgrowth (SIBO), focusing on the potential impact of acid-suppressive drugs. We also explore changes in gut microbiota and metabolism in patients with both conditions.

Methods

This study included patients from the Department of Gastroenterology, Beijing Shijitan Hospital, between February 2021 and November 2023. All patients underwent assessments including questionnaires, hydrogen and methane breath tests, and gastroscopy. GERD was diagnosed using the GERD-Q scale and gastroscopy, while SIBO was diagnosed via breath tests. We analyzed the correlation between GERD and SIBO, identified risk factors for SIBO, and examined the gut microbiota using 16S rRNA sequencing to explore the relationship between GERD and SIBO.

Results

The retrospective study included 394 patients.148 with GERD and 287 with positive SIBO results. Among these, 270 had a positive methane (CH4) breath test and 97 had a positive hydrogen (H2) breath test. GERD was more common in patients with positive SIBO (P = 0.007), and the link between CH4 breath tests and GERD was stronger than that with H2 breath tests (P = 0.020). Logistic regression showed GERD is an independent risk factor for SIBO. Short-term, low-dose acid-suppressive drugs did not affect SIBO development. 16S rRNA sequencing of fecal microbiota from 24 patients showed dominant microbiota in SIBO-positive GERD patients included bacteroides uniformis and bacteroides stercoris. Patients with both GERD and SIBO had differential metabolites, mainly associated with ATP-Binding Cassette transporters (ABC transporters).

Conclusion

GERD is strongly linked to SIBO, especially in patients with a positive CH4 breath test. The gut microbiota in GERD and SIBO patients differs from healthy individuals, with bacteroides uniformis as a key marker. Metabolic changes are mainly related to ABC transporter metabolites.

Evaluation of curcumin nanoparticles of various sizes for targeting multidrug-resistant lung cancer cells via inhalation

INTRODUCTION

Inhalation drug delivery can deliver high doses of chemotherapeutic drugs to the lung tumor. This study evaluates the efficacy and the mechanistic pathways of nebulized Cur NPs at various sizes to treat multidrug resistant lung cancer.

METHODS AND RESULTS

Cur-NPs (30 nm and 200 nm) were nebulized separately onto the multidrug-resistant lung cancer cells (H69AR). Smaller NPs induced significantly higher cell death owing to a higher rate of particle internalization via dynamin-dependent clathrin-mediated endocytosis. Owing to the higher lysosome trafficking of Cur-NP30 nm compared to Cur-NP200 nm, oxidation of lysosome was higher (0.47 ± 0.08 vs 0.38 ± 0.08), contributing to significantly higher mitochondrial membrane potential loss (1.57 ± 0.17 vs 1.30 ± 0.11). MRP1 level in H69AR cells was reduced from 352 ± 12.3 ng/µg of protein (untreated cells) to 287 ± 12 ng/µg of protein (Cur-NP30 nm) and 303 ± 13.4 ng/µg of protein (Cur-NP200 nm). NF-κB, and various cytokine expressions were reduced after treatment with nebulized Cur-NPs.

CONCLUSIONS

Nebulized Cur-NPs formulations could be internalized into the H69AR cells. The Cur-NPs toxicity toward the H69AR was size and time-dependent. Cur-NP30 nm was more effective than Cur-NP200 nm to retain within the cells to exert higher oxidative stresss-induced cell death.

The role of ABCG2 in health and disease: Linking cancer therapy resistance and other disorders

All biological systems have adenosine triphosphate (ATP) binding cassette (ABC) transporters, one of the significant protein superfamilies involved in transport across membranes. ABC transporters have been implicated in the etiology of diseases like metabolic disorders, cancer, and Alzheimer's disease. ATP-binding cassette superfamily G member 2 (ABCG2), one of the ABC transporters, is necessary for the ATP-dependent efflux of several endogenous and exogenous substances. Consequently, it maintained cellular homeostasis and shielded tissue from xenobiotic substances. ABCG2 was initially identified in an Adriamycin-selected breast cancer cell line (MCF-7/AdrVp) and was linked to the emergence of multidrug resistance (MDR) in cancerous cells. Under many pathophysiological conditions, including inflammation, disease pathology, tissue injury, infection, and in response to xenobiotics and endogenous substances, the expression of ABCG2 undergoes alterations that result in modifications in its function and activity. Genetic variants in the ABCG2 transporter can potentially impact its expression and function, contributing to the development of many disorders. This review aimed to illustrate the impact of ABCG2 expression and its variants on oral drug bioavailability, MDR in specific cancer cells, explore the relationship between ABCG2 expression and other disorders such as gout, Alzheimer's disease, epilepsy, and erythropoietic protoporphyria, and demonstrate the influence of various synthetic and natural compounds in regulating ABCG2 expression.

The role of surface modification in the interactions between CdTe quantum dots and ABC transporters in lung cancer cells

This paper aimed to investigate the role of surface modification on the potential interaction between CdTe quantum dots (QDs) and ABC transporters in doxorubicin-resistant lung cancer (A549/DOX) cells. For this purpose, CdTe QDs modified with -glutathione (GSH), -carboxy (COOH), and -amino (NH2) were applied, with the former two QDs exhibiting negative potentials and the latter ones being positive. All the three QDs reduced cell viability in a concentration-dependent manner, with NH2-CdTe QDs being more toxic. Such phenomena might be due to the adherence of NH2-CdTe QDs to negative cell membrane and thereby causing an enhanced accumulation. Addition of transporter inhibitors significantly enhanced the intracellular accumulation and toxicity of negative QDs, but such phenomena were barely found or even reversed for NH2-CdTe QDs, indicating that ABC transporters mainly excreted negative QDs. All the QDs caused little effects on the mRNA expression of ABC transporters, which should be due to the fact that the induction effects of QDs have been attenuated by the disruption of cell membrane. Overall, these results reveal the mechanism by which ABC transporters are involved in the efflux of CdTe QDs with different surface modifications, which could help the detoxification of QDs in the environment.

Efficacy, safety, and biomarker analysis of first-line immune checkpoint inhibitors with chemotherapy versus chemotherapy for advanced gastric cancer: a multicenter, retrospective cohort study

BACKGROUND

Recent phase III randomized controlled trials have demonstrated that first-line immune checkpoint inhibitors (ICIs) improve prognosis in advanced HER-2-negative gastric cancer patients with programmed death ligand 1 (PD-L1) combined positive score (CPS) higher than 5. However, these findings are not confirmed in real-world settings, and the benefits in PD-L1 CPS < 5 patients remain controversial.

METHODS

In this multicenter, retrospective cohort study, data from across thirteen medical centers were analyzed by inverse probability of treatment weighting for matching, alongside univariate and multivariate COX proportional hazard regression models. Genomic and transcriptomic analyses were conducted to identify efficacy prognostic models and resistance mechanisms.

RESULTS

This study included 573 patients with advanced gastric cancer, 265 treated with chemotherapy and 308 with ICIs plus chemotherapy. In the overall cohort and HER-2-negative patients, the combination therapy significantly improved progression-free survival and overall survival, without marked increases in severe adverse events. Notably, patients with PD-L1 CPS 1-4 showed significant overall survival prolongation and a trend towards improved progression-free survival with combination therapy. Patients with unknown PD-L1 status also benefitted from ICIs. SMARCA4 and BRCA2 mutations were more frequent in patients with responses, while CCNE1 and ZFHX3 alternation, alongside high "ABC transporters" signatures, were more common in non-responsive patients. A novel risk model, PGFIC, outperformed traditional biomarkers in predicting treatment outcomes.

CONCLUSIONS

Adding ICIs to first-line treatment significantly prolongs survival in overall patients and in those with PD-L1 CPS 1-4 or unknown. This study also provides valuable insights into prognostic markers and resistance mechanisms, potentially guiding immunotherapy strategies.

Complex IIa formation and ABC transporters determine sensitivity of OSCC to Smac mimetics

Small molecule inhibitors of apoptosis proteins (IAPs) antagonists, known as Smac mimetics (SMs), activate non-canonical NF-κB and sensitize cancer cells to TNF-induced cell death. SMs are currently in phase III clinical trials for head and neck squamous cell carcinoma (HNSCC) after promising phase II trials. To explore the utility of SMs in oral squamous cell carcinoma (OSCC), we tested nine human OSCC cell lines and correlated SM sensitivity with both IAP mutation and expression levels. cIAP1 protein expression was shown to be higher in OSCC and a predictor of poor prognosis. However, our in vitro and in vivo testing demonstrated differential sensitivity to SMs, which did not correlate with cIAP1 and cIAP2 expression in these OSCC cell lines. Exogenous TNF failed to effectively increase the sensitivity of SM-resistant OSCC cells to SM-induced cell death. SM resistance was associated with a deficiency in Complex IIa formation, but activation of non-canonical NF-κB was not a determinant of SM efficacy. Finally, metabolic analysis revealed that the ABC transporter pathway was activated in SM-resistant OSSC cells, and SMs combined with ABC transporter inhibitors improved cell death sensitivity to overcome SM resistance. These studies highlight the therapeutic potential of SMs in OSCC and support patient stratification to improve efficacy with the addition of adjuvant therapy.

Patient-Derived Organoids on a Microarray for Drug Resistance Study in Breast Cancer

Drug resistance is always a challenge in cancer treatment, whether for chemotherapy, targeting, or immunotherapy. Although tumor cell lines are derived from cancer patients, they gradually lost the original characteristics, including heterogeneity and tumor microenvironment (TME), during the long period of in vitro culturing. Therefore, it is urgent to use patient-derived tumor models instead of cancer cell lines to study tumor drug resistance. Herein, we developed a microarray device that serves as a platform for high-throughput and three-dimensional culture of breast cancer patient-derived organoids (BCOs) and investigated their resistance to adriamycin (ADM). Coupled with fluorescence microscopy, this system enabled on-chip drug response monitoring and cell viability assessment without the consumption of a large number of tumor cells. The organoids were divided into a resistant BCO group (RBCO) and a sensitive BCO group (SBCO) according to their half-inhibitory concentration (IC50). Different from cancer cell lines, BCOs demonstrated obvious heterogeneity in drug treatment. Ivermectin (IVM), a broad-spectrum antiparasitic agent approved by the Food and Drug Administration (FDA), was observed to synergistically augment ADM-induced cytotoxicity in organoids. The BCO chip provides a promising platform for investigation of drug resistance and preclinical drug screening based on clinical samples.

Synthesis and evaluation of novel tetrahydroisoquinoline-benzo[h]chromen-4-one conjugates as dual ABCB1/CYP1B1 inhibitors for overcoming MDR in cancer

The emergence of multidrug resistance (MDR) in malignant tumors is one of the major threats encountered currently by many chemotherapeutic agents. Among the various mechanisms involved in drug resistance, P-glycoprotein (P-gp, ABCB1), a member of the ABC transporter family that significantly increases the efflux of various anticancer drugs from tumor cells, and the metabolic enzyme CYP1B1 are widely considered to be two critical targets for overcoming MDR. Unfortunately, no MDR modulator has been approved by the FDA to date. In this study, based on pharmacophore hybridization, bioisosteric and fragment-growing strategies, we designed and synthesized 11 novel tetrahydroisoquinoline-benzo[h]chromen-4-one conjugates as dual ABCB1/CYP1B1 inhibitors. Among them, the preferred compound A10 exhibited the best MDR reversal activity (IC50 = 0.25 μM, RF = 44.4) in SW620/AD300 cells, being comparable to one of the most potent third-generation P-gp inhibitors WK-X-34. In parallel, this dual ABCB1/CYP1B1 inhibitory effect drives compound A10 exhibiting prominent drug resistance reversal activity to doxorubicin (IC50 = 4.7 μM, RF = 13.7) in ABCB1/CYP1B1-overexpressing DOX-SW620/AD300-1B1 resistant cells, which is more potent than that of the CYP1B1 inhibitor ANF. Furthermore, although compound A2 possessed moderate ABCB1/CYP1B1 inhibitory activity, it showed considerable antiproliferative activity towards drug-resistant SW620/AD300 and MKN45-DDP-R cells, which may be partly related to the increase of PUMA expression to promote the apoptosis of the drug-resistant MKN45-DDP-R cells as confirmed by proteomics and western blot assay. These results indicated that the tetrahydroisoquinoline-benzo[h]chromen-4-one conjugates may provide a fundamental scaffold reference for further discovery of MDR reversal agents.

Low-intensity pulsed ultrasound combined with microbubble mediated JNK/c-Jun pathway to reverse multidrug resistance in triple-negative breast cancer

To investigate the effects of low-intensity pulsed ultrasound combined with microbubble (LIPUS-MB) mediated JNK/c-Jun pathway reversal on multidrug resistance in triple-negative breast cancer and the underlying mechanisms. An orthogonal experiment was designed to screen for the optimal parameters of LIPUS-MB in MDA-MB-231/DOX cells. The CCK-8 assay was used to determine the drug resistance of the cells and to measure their proliferation activity and resistance reversal efficiency at the optimal parameters. Hoechst 33,342 staining and Annexin V-FITC/PI staining were employed to detect cell morphological changes and apoptosis, respectively. The MDA-MB-231/DOX models of transplanted tumor were established in BALB/c. The impact of LIPUS-MB on allograft tumor growth was observed in vivo. Immunohistochemistry was employed to investigate the expression of P-gp, ABCG2, and Ki-67 in tumor tissues, while western blot was utilized to assess the protein expression of P-gp, ABCG2, JNK, p-JNK, c-Jun, p-c-Jun, Bcl-2 and Bax in both MDA-MB-231/DOX cells and allograft tumor tissues. The optimal LIPUS-MB parameters for MDA-MB-231/DOX cells are the microbubble concentration of 20%, ultrasound intensity of 1.0 W/cm2, and irradiation time of 60 s. The drug resistance index of MDA-MB-231/DOX cells is 19.17. Following the optimal parameter application, the IC50 value of the cells decreases by 5.71-fold, with a reversal efficiency of 87.03%, and a simultaneous decrease in cell proliferation activity. Compared with other groups, the DOX + LIPUS-MB group displayed the highest incidence of apoptotic nuclear morphology, and the greatest quantity of cellular apoptosis and the most pronounced decrease in the expression levels of P-gp, ABCG2, p-JNK, p-c-Jun, and Bcl-2 proteins within the cells. Conversely, the expression levels of Bax proteins reach the highest levels (all P < 0.05). Furthermore, in vivo subcutaneous tumor transplantation experiments in nude mice revealed that the DOX + LIPUS-MB group exhibited smaller tumor growth rate, volume and the expression of P-gp, ABCG2, and Ki-67 compared to the DOX + LIPUS group, indicating the most pronounced inhibitory effect on tumor growth and it significantly inhibited tumor proliferation, promoted its apoptosis. In conclusion, following parameter optimization, LIPUS-MB was found to reduce the drug resistance of MDA-MB-231/DOX cells. The underlying mechanism may involve the downregulation of P-gp and ABCG2 proteins expression through the modulation of the JNK/c-Jun pathway by LIPUS-MB, thereby inhibiting cell proliferation activity and promoting apoptosis, and enhancing the in vivo anti-tumor effect of DOX, thus reversing multidrug resistance in triple-negative breast cancer.

Unraveling the secrets: Evolution of resistance mediated by membrane proteins

Membrane protein-mediated resistance is a multidisciplinary challenge that spans fields such as medicine, agriculture, and environmental science. Understanding its complexity and devising innovative strategies are crucial for treating diseases like cancer and managing resistant pests in agriculture. This paper explores the dual nature of resistance mechanisms across different organisms: On one hand, animals, bacteria, fungi, plants, and insects exhibit convergent evolution, leading to the development of similar resistance mechanisms. On the other hand, influenced by diverse environmental pressures and structural differences among organisms, they also demonstrate divergent resistance characteristics. Membrane protein-mediated resistance mechanisms are prevalent across animals, bacteria, fungi, plants, and insects, reflecting their shared survival strategies evolved through convergent evolution to address similar survival challenges. However, variations in ecological environments and biological characteristics result in differing responses to resistance. Therefore, examining these differences not only enhances our understanding of adaptive resistance mechanisms but also provides crucial theoretical support and insights for addressing drug resistance and advancing pharmaceutical development.

Terpenoids from quinoa reverse drug resistance of colon cancer by upregulating miR-495-3p

BACKGROUND

Quinoa contains far more nutrients than any traditional grain crop. It is known that terpenoids in quinoa have anti-inflammatory and antitumor effects, but their role in reversing drug resistance remains unclear.

RESULTS

Our previous studies showed that quinoa-derived terpenoid compounds (QBT) can inhibit the occurrence and development of colon cancer. This study further indicates that QBT markedly reverse drug resistance of colon cancer. The results showed that QBT combined with 5-fluorouracil (5-Fu) treatment significantly enhanced the chemotherapy sensitivity of HCT-8/Fu, compared with 5-Fu treatment alone. Moreover, we found that QBT significantly reduced the expression of drug-resistant proteins (P-gp, MRP1, BCRP), and increased the accumulation of chemotherapy drugs. Taking P-gp as the target for biogenesis prediction analysis, results showed that upregulation of miR-495-3p enhanced the chemosensitivity of drug-resistant HCT-8/Fu cells. Besides, the results showed that miR-495-3p was abnormally methylated in HCT-8/Fu compared with HCT-8 colon cancer cells. The expression of methyltransferases DNMT1, DNMT3a and DNMT3b was abnormal. After QBT treatment, the expression level of methyltransferases returned to normal. In addition, the QBT + 5Fu group showed inhibition of tumors in nude mice.

CONCLUSION

QBT treatment downregulated the expression of drug-resistant protein P-gp by inhibiting the methylation of miR-495-3p, and enhanced the accumulation of 5-Fu in vivo, which in turn reversed its chemoresistance. This suggests that QBT has potential ability as a new drug-resistance reversal agent in colorectal cancer. © 2024 Society of Chemical Industry.

Application of Carbon Nanomaterials to Enhancing Tumor Immunotherapy: Current Advances and Prospects

Recent advances in tumor immunotherapy have highlighted the pivotal role of carbon nanomaterials, such as carbon dots, graphene quantum dots, and carbon nanotubes. This review examines the unique benefits of these materials in cancer treatment, focusing on their mechanisms of action within immunotherapy. These include applications in immunoregulation, recognition, and enhancement. We explore how these nanomaterials when combined with specific biomolecules, can form immunosensors. These sensors are engineered for highly sensitive and specific detection of tumor markers, offering crucial support for early diagnosis and timely therapeutic interventions. This review also addresses significant challenges facing carbon nanomaterials in clinical settings, such as issues related to long-term biocompatibility and the hurdles of clinical translation. These challenges require extensive ongoing research and discussion. This review is of both theoretical and practical importance, aiming to promote using carbon nanomaterials in tumor immunotherapy, potentially transforming clinical outcomes and enhancing patient care.

Global research trends and hotspots in metabolomics of osteosarcoma: a decade-spanning bibliometric and visualized analysis

OBJECT

Osteosarcoma is a malignant tumor originating from the bones, commonly found in children and adolescents, especially in rapidly growing bone areas such as the knees and upper arms. In this study, we aim to delineate the evolution and convergence of research themes in osteosarcoma metabolomics over the past decade, identify major contributors, and forecast emerging trends that could direct future research efforts.

METHOD

The bibliometric method has been applied to systematically analyze the literature in the field of osteosarcoma metabolomics. The relevant literatures were collected from the Web of Science Core Collection, spanning from January 1, 2014, to December 31, 2023. Tools such as CiteSpace, Bibliometrix, and VOSviewer were used for the visual analysis of the collected literatures. The focused information includes institutions, journals, countries, authors, keywords, and citations.

RESULT

Various aspects in the field of osteosarcoma metabolism were analyzed. Shanghai Jiao Tong University has published the most papers in the past ten years, followed by Central South University and Zhejiang University. Among the sources, the international journal of molecular sciences publishes the most articles, and oncotarget is the journal with the highest H index. According to Bradford's law, there are 34 core journals identified. A total of 5501 authors participated in the creation of papers in this field. The distribution of authors follows Lotka`s Law, and 85.3% of authors have only one article. 46% of the corresponding authors are from China, but most of these corresponding authors are not good at international cooperation. China also has the largest number of publications, followed by the United States. It can be confirmed that China dominates this field. Among the keywords, "expression" is the keyword that has received the most attention in the past ten years. All keywords can be divided into 9 clusters. Based on the explosive words and hot topics each year, we speculate that future research will focus on the tumor microenvironment, molecular mechanisms and autophagy, targeted therapies and inhibitors.

CONCLUSION

In summary, this study comprehensively analyzed the current state of research in the field of osteosarcoma metabolism through bibliometric methods. The findings revealed the development trends and research hotspots in this field, which may provide valuable references for future research directions.

Exploring tumor microenvironment in molecular subtyping and prognostic signatures in ovarian cancer and identification of SH2D1A as a key regulator of ovarian cancer carcinogenesis

Introduction

A deadly gynecological cancer, ovarian cancer (OV), has a poor prognosis because of late-stage diagnosis and few targeted therapies. Addressing the tumor microenvironment (TME) in solid tumors has shown promise since it is crucial in promoting cancer progression.

Methods

We obtained bulk RNA-seq data from TCGA-OV, GSE26712, GSE102073, and ICGC cohorts, as well as scRNA-seq data from EMTAB8107, GSE118828, GSE130000, and GSE154600 cohorts using the TISCH2 database. The ConsensusClusterPlus package was used to cluster the OV tumor tissues hierarchically to determine two molecularly different groups (C1 and C2). A total of ten different types of machine learning techniques with 101 combinations were used for prognostic model construction. Using eight TME algorithms integrated into the IOBR R package, the bulk RNA-seq dataset was analyzed. For in vitro experiments, OVCAR3 and SKOV3, two OV cell lines, were used. The migratory potential of the ovarian cancer cells was assessed using Transwell assay, while proliferation was assessed using CCK8 assay.

Results

Based on TME-related gene set expression, two distinct molecular subgroups (C1 and C2) were identified through consensus clustering, with C1 showing higher TME activity. Further analysis indicated that C1 had increased cancer-associated fibroblasts (CAFs), M1 macrophages, and CD8+ T cells, suggesting a more activated and pro-inflammatory TME. Drug sensitivity analysis revealed that 5-Fluorouracil might be beneficial to C1 patients. Functional differences between C1 and C2 were identified, including cell adhesion, mononuclear cell differentiation, and leukocyte migration. A machine learning model was developed to create a TME-related prognostic signature, demonstrating strong prognostic capabilities across multiple datasets. High-risk patients showed a more immune-suppressive TME and higher tumor stemness. ScRNA-seq disclosed a highly activated TME-related signature in OV. Cancer cell lines had significantly higher SH2D1A mRNA expression than normal ovarian epithelial cells. We observed that SH2D1A knockdown in 2 ovarian cancer cell lines (OVCAR3 and SKOV3) reduced migration and proliferation through a series of in-vitro experiments.

Conclusion

TME-associated genes were efficient in ovarian cancer molecular subtyping. A TME-based prognosis model was constructed for vigorous prognostic stratification efficacy across multiple datasets. Moreover, we identified a pivotal role of SH2D1A in promoting proliferation and migration in ovarian cancer.

Enhancing cancer immunotherapy: Nanotechnology-mediated immunotherapy overcoming immunosuppression

Immunotherapy is an important cancer treatment method that offers hope for curing cancer patients. While immunotherapy has achieved initial success, a major obstacle to its widespread adoption is the inability to benefit the majority of patients. The success or failure of immunotherapy is closely linked to the tumor's immune microenvironment. Recently, there has been significant attention on strategies to regulate the tumor immune microenvironment in order to stimulate anti-tumor immune responses in cancer immunotherapy. The distinctive physical properties and design flexibility of nanomedicines have been extensively utilized to target immune cells (including tumor-associated macrophages (TAMs), T cells, myeloid-derived suppressor cells (MDSCs), and tumor-associated fibroblasts (TAFs)), offering promising advancements in cancer immunotherapy. In this article, we have reviewed treatment strategies aimed at targeting various immune cells to regulate the tumor immune microenvironment. The focus is on cancer immunotherapy models that are based on nanomedicines, with the goal of inducing or enhancing anti-tumor immune responses to improve immunotherapy. It is worth noting that combining cancer immunotherapy with other treatments, such as chemotherapy, radiotherapy, and photodynamic therapy, can maximize the therapeutic effects. Finally, we have identified the challenges that nanotechnology-mediated immunotherapy needs to overcome in order to design more effective nanosystems.

Overexpression of SLC2A1, ALDOC, and PFKFB4 in the glycolysis pathway drives strong drug resistance in 3D HeLa tumor cell spheroids

The 3D multicellular tumor spheroid (MTS) model exhibits enhanced fidelity in replicating the tumor microenvironment and demonstrates exceptional resistance to clinical drugs compared to the 2D monolayer model. In this study, we used multiomics (transcriptome, proteomics, and metabolomics) tools to explore the molecular mechanisms and metabolic differences of the two culture models. Analysis of Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment pathways revealed that the differentially expressed genes between the two culture models were mainly enriched in cellular components and biological processes associated with extracellular matrix, extracellular structural organization, and mitochondrial function. An integrated analysis of three omics data revealed 11 possible drug resistance targets. Among these targets, seven genes, AKR1B1, ALDOC, GFPT2, GYS1, LAMB2, PFKFB4, and SLC2A1, exhibited significant upregulation. Conversely, four genes, COA7, DLD, IFNGR1, and QRSL1, were significantly downregulated. Clinical prognostic analysis using the TCGA survival database indicated that high-expression groups of SLC2A1, ALDOC, and PFKFB4 exhibited a significant negative correlation with patient survival. We further validated their involvement in chemotherapy drug resistance, indicating their potential significance in improving prognosis and chemotherapy outcomes. These results provide valuable insights into potential therapeutic targets that can potentially enhance treatment efficacy and patient outcomes.

Unveiling the functional roles of patient-derived tumour organoids in assessing the tumour microenvironment and immunotherapy

Recent studies have established the pivotal roles of patient-derived tumour organoids (PDTOs), innovative three-dimensional (3D) culture systems, in various biological and medical applications. PDTOs, as promising tools, have been established and extensively used for drug screening, prediction of immune response and assessment of immunotherapeutic effectiveness in various cancer types, including glioma, ovarian cancer and so on. The overarching goal is to facilitate the translation of new therapeutic modalities to guide personalised immunotherapy. Notably, there has been a recent surge of interest in the co-culture of PDTOs with immune cells to investigate the dynamic interactions between tumour cells and immune microenvironment. A comprehensive and in-depth investigation is necessary to enhance our understanding of PDTOs as promising testing platforms for cancer immunotherapy. This review mainly focuses on the latest updates on the applications and challenges of PDTO-based methods in anti-cancer immune responses. We strive to provide a comprehensive understanding of the potential and prospects of PDTO-based technologies as next-generation strategies for advancing immunotherapy approaches.

FAT1 as a tumor mutation burden specific gene affects the immunotherapy effect in head and neck squamous cell cancer

BACKGROUND

Response to immunotherapy is the main challenge of head and neck squamous cancer (HNSCC) treatment. Previous studies have indicated that tumor mutational burden (TMB) is associated with prognosis, but it is not always a precise index. Hence, investigating specific genetic mutations and tumor microenvironment (TME) changes in TMB-high patients is essential for precision therapy of HNSCC.

METHODS

A total of 33 HNSCC patients were enrolled in this study. We calculated the TMB score based on next-generation sequencing (NGS) sequencing and grouped these patients based on TMB score. Then, we examined the immune microenvironment of HNSCC using assessments of the bulk transcriptome and the single-cell RNA sequence (scRNA-seq) focusing on the molecular nature of TMB and mutations in HNSCC from our cohort. The association of the mutation pattern and TMB was analyzed in The Cancer Genome Atlas (TCGA) and validated by our cohort.

RESULTS

33 HNSCC patients were divided into three groups (TMB-low, -medium, and -high) based on TMB score. In the result of 520-gene panel sequencing data, we found that FAT1 and LRP1B mutations were highly prevalent in TMB-high patients. FAT1 mutations are associated with resistance to immunotherapy in HNSCC patients. This involves many metabolism-related pathways like RERE, AIRE, HOMER1, etc. In the scRNA-seq data, regulatory T cells (Tregs), monocytes, and DCs were found mainly enriched in TMB-high samples.

CONCLUSION

Our analysis unraveled the FAT1 gene as an assistant predictor when we use TMB as a biomarker of drug resistance in HNSCC. Tregs, monocytes, and dendritic cells (DCs) were found mainly enriched in TMB-high samples.

A Review of the Efficacy of Nanomaterial-Based Natural Photosensitizers to Overcome Multidrug Resistance in Cancer

Natural photosensitizers (PS) are compounds derived from nature, with photodynamic properties. Natural PSs have a similar action to that of commercial PSs, where cancer cell death occurs by necrosis, apoptosis, and autophagy through ROS generation. Natural PSs have garnered great interest over the last few decades because of their high biocompatibility and good photoactivity. Specific wavelengths could cause phytochemicals to produce harmful ROS for photodynamic therapy (PDT). However, natural PSs have some shortcomings, such as reduced solubility and lower uptake, making them less appropriate for PDT. Nanotechnology offers an opportunity to develop suitable carriers for various natural PSs for PDT applications. Various nanoparticles have been developed to improve the outcome with enhanced solubility, optical adsorption, and tumor targeting. Multidrug resistance (MDR) is a phenomenon in which tumor cells develop resistance to a wide range of structurally and functionally unrelated drugs. Over the last decade, several researchers have extensively studied the effect of natural PS-based photodynamic treatment (PDT) on MDR cells. Though the outcomes of clinical trials for natural PSs were inconclusive, significant advancement is still required before PSs can be used as a PDT agent for treating MDR tumors. This review addresses the increasing literature on MDR tumor progression and the efficacy of PDT, emphasizing the importance of developing new nano-based natural PSs in the fight against MDR that have the required features for an MDR tumor photosensitizing regimen.

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.

Prenatal opioid exposure significantly impacts placental protein kinase C (PKC) and drug transporters, leading to drug resistance and neonatal opioid withdrawal syndrome

Background

Neonatal Opioid Withdrawal Syndrome (NOWS) is a consequence of in-utero exposure to prenatal maternal opioids, resulting in the manifestation of symptoms like irritability, feeding problems, tremors, and withdrawal signs. Opioid use disorder (OUD) during pregnancy can profoundly impact both mother and fetus, disrupting fetal brain neurotransmission and potentially leading to long-term neurological, behavioral, and vision issues, and increased infant mortality. Drug resistance complicates OUD and NOWS treatment, with protein kinase regulation of drug transporters not fully understood.

Methods

DNA methylation levels of ATP-binding cassette (ABC) and solute carrier (SLC) drug transporters, along with protein kinase C (PKC) genes, were assessed in 96 placental samples using the Illumina Infinium MethylationEPIC array (850K). Samples were collected from three distinct groups: 32 mothers with infants prenatally exposed to opioids who needed pharmacological intervention for NOWS, 32 mothers with prenatally opioid-exposed infants who did not necessitate NOWS treatment, and 32 mothers who were not exposed to opioids during pregnancy.

Results

We identified 69 significantly differentially methylated SLCs, with 24 hypermethylated and 34 hypomethylated, and 11 exhibiting both types of methylation changes including SLC13A3, SLC15A2, SLC16A11, SLC16A3, SLC19A2, and SLC26A1. We identified methylation changes in 11 ABC drug transporters (ABCA1, ABCA12, ABCA2, ABCB10, ABCB5, ABCC12, ABCC2, ABCC9, ABCE1, ABCC7, ABCB3): 3 showed hypermethylation, 3 hypomethylation, and 5 exhibited both. Additionally, 7 PKC family genes (PRKCQ, PRKAA1, PRKCA, PRKCB, PRKCH, PRKCI, and PRKCZ) showed methylation changes. These genes are associated with 13 pathways involved in NOWS, including ABC transporters, bile secretion, pancreatic secretion, insulin resistance, glutamatergic synapse, and gastric acid secretion.

Conclusion

We report epigenetic changes in PKC-related regulation of drug transporters, which could improve our understanding of clinical outcomes like drug resistance, pharmacokinetics, drug-drug interactions, and drug toxicity, leading to maternal relapse and severe NOWS. Novel drugs targeting PKC pathways and transporters may improve treatment outcomes for OUD in pregnancy and NOWS.

Dachsous cadherin related 1 (DCHS1) is a novel biomarker for immune infiltration and epithelial-mesenchymal transition in endometrial cancer via pan-cancer analysis

BACKGROUND

Dachsous cadherin related 1 (DCHS1) is one of calcium-dependent adhesion membrane proteins and is mainly involved in the development of mammalian tissues. There is a lack of more detailed research on the biological function of DCHS1 in pan-cancer.

MATERIALS AND METHODS

We evaluated the expression, the prognostic value, the diagnostic value and genomic alterations of DCHS1 by using the databases, including TCGA, UALCAN, HPA, GEPIA2.0 and GSCA. We employed the databases of UCSC, TIMER2.0, TISIDB, GSCA to analyze the association between DCHS1 expression and the immune microenvironment, stemness, TMB, MSI and anticancer drug sensitivity. BioGRID, STRING and GEPIA2.0 were used to perform protein interaction and functional enrichment analysis. Real-time quantitative PCR, CCK8, Transwell assay and Western blot were performed to determine the function of DCHS1 in UCEC.

RESULTS

DCHS1 is differentially expressed in many cancers and its expression is significantly associated with tumor prognosis and diagnosis. DCHS1 expression was significantly correlated with the infiltration of cancer-associated fibroblasts (CAFs), Endothelial cell (ECs), and Hematopoietic stem cell in most cancers. In addition, DCHS1 was significantly associated with sensitivity to many antitumor drugs. Functional enrichment analysis revealed that DCHS1-related proteins were involved in Focal adhesion, Endometrial cancer and Wnt signaling pathway. GSEA results showed that DCHS1 was related to epithelial-mesenchymal transition (EMT) in many cancers. In vitro experiments in UCEC showed that DCHS1 regulated cell proliferation, migration and EMT.

CONCLUSIONS

Our findings indicated that DCHS1 might be a novel prognostic and diagnostic biomarker and immunotherapy target, and plays an important role in the proliferation, migration and EMT in UCEC.

Efflux ABC transporters in drug disposition and their posttranscriptional gene regulation by microRNAs

ATP-binding cassette (ABC) transporters are transmembrane proteins expressed commonly in metabolic and excretory organs to control xenobiotic or endobiotic disposition and maintain their homeostasis. Changes in ABC transporter expression may directly affect the pharmacokinetics of relevant drugs involving absorption, distribution, metabolism, and excretion (ADME) processes. Indeed, overexpression of efflux ABC transporters in cancer cells or bacteria limits drug exposure and causes therapeutic failure that is known as multidrug resistance (MDR). With the discovery of functional noncoding microRNAs (miRNAs) produced from the genome, many miRNAs have been revealed to govern posttranscriptional gene regulation of ABC transporters, which shall improve our understanding of complex mechanism behind the overexpression of ABC transporters linked to MDR. In this article, we first overview the expression and localization of important ABC transporters in human tissues and their clinical importance regarding ADME as well as MDR. Further, we summarize miRNA-controlled posttranscriptional gene regulation of ABC transporters and effects on ADME and MDR. Additionally, we discuss the development and utilization of novel bioengineered miRNA agents to modulate ABC transporter gene expression and subsequent influence on cellular drug accumulation and chemosensitivity. Findings on posttranscriptional gene regulation of ABC transporters shall not only improve our understanding of mechanisms behind variable ADME but also provide insight into developing new means towards rational and more effective pharmacotherapies.

Construction and validation of a TTN mutation associated immune prognostic model for evaluating immune microenvironment and outcomes of gastric cancer: An observational study

Gastric cancer (GC) is a prevalent form of cancer worldwide, and TTN (titin) mutations are frequently observed in GC. However, the association between TTN mutations and immunotherapy for GC remains unclear, necessitating the development of novel prognostic models. The prognostic value and potential mechanisms of TTN in stomach adenocarcinoma were evaluated by TCGA (The Cancer Genome Atlas)-stomach adenocarcinoma cohort analysis, and an immune prognostic model was constructed based on TTN status. We validated it using the GSE84433 dataset. We performed Gene Set Enrichment Analysis and screened for differentially expressed genes, and used lasso (least absolute shrinkage and selection operator) regression analysis to screen for survival genes to construct a multifactorial survival model. In addition, we evaluated the relative proportions of 22 immune cells using the CIBERSORT algorithm for immunogenicity analysis. Finally, we constructed the nomogram integrating immune prognostic model and other clinical factors. GESA showed enrichment of immune-related phenotypes in patients with TTN mutations. We constructed an immune prognostic model based on 16 genes could identify gastric cancer patients with higher risk of poor prognosis. Immuno-microenvironmental analysis showed increased infiltration of naive B cells, plasma cells, and monocyte in high-risk patients. In addition, Nomo plots predicted the probability of 1-year, 3-year, and 5-year OS (overall survival) in GC patients, showing good predictive performance. In this study, we identified that TTN gene may be a potential clinical biomarker for GC and TTN mutations may be a predictor of immunotherapy in patients. We constructed and validated a new model for prognosis of GC patients based on immune characteristics associated with TTN mutations. This study may provide potential therapeutic strategies for gastric cancer.

Lipid Nanoparticular Codelivery System for Enhanced Antitumor Effects by Ferroptosis-Apoptosis Synergistic with Programmed Cell Death-Ligand 1 Downregulation

Intrinsic or acquired resistance to chemical drugs severely limits their therapeutic efficacy in cancer treatment. Various intracellular antioxidant molecules, particularly glutathione (GSH), play a crucial role in maintaining intracellular redox homeostasis by mitigating the overproduced reactive oxygen species (ROS) due to rapid cell proliferation. Notably, these antioxidants also eliminate chemical-drug-induced ROS, eventually diminishing their cytotoxicity and rendering them less effective. In this study, we combined erastin, a GSH biosynthesis inhibitor, with 2'-deoxy-5-fluorouridine 5'-monophosphate sodium salt (FdUMP), an ROS-based drug, to effectively disrupt intracellular redox homeostasis and reverse chemotherapy resistance. Therefore, efficient ferroptosis and apoptosis were simultaneously induced for enhanced antitumor effects. Additionally, we employed small interfering RNA targeting PD-L1 (siPD-L1) as a third agent to block immune-checkpoint recognition by CD8+ T cells. The highly immunogenic cell peroxidates or damage-associated molecular patterns (DAMPs) induced by erastin acted synergistically with downregulated PD-L1 to enhance the antitumor effects. To codeliver these three drugs simultaneously and efficiently, we designed GE11 peptide-modified lipid nanoparticles (LNPs) containing calcium phosphate cores to achieve high encapsulation efficiencies. In vitro studies verified its enhanced cytotoxicity, efficient intracellular ROS induction and GSH/GPX4 downregulation, substantial lipid peroxidation product accumulation, and mitochondrial depolarization. In vivo, this formulation effectively accumulated at tumor sites and achieved significant tumor inhibition in subcutaneous colon cancer (CRC) mouse models with a maximum tumor inhibition rate of 83.89% at a relatively low dose. Overall, a strategy to overcome clinical drug resistance was verified in this study by depleting GSH and activating adaptive immunity.

Application of biomimetic nanovaccines in cancer immunotherapy: A useful strategy to help combat immunotherapy resistance

Breakthroughs in actual clinical applications have begun through vaccine-based cancer immunotherapy, which uses the body's immune system, both humoral and cellular, to attack malignant cells and fight diseases. However, conventional vaccine approaches still face multiple challenges eliciting effective antigen-specific immune responses, resulting in immunotherapy resistance. In recent years, biomimetic nanovaccines have emerged as a promising alternative to conventional vaccine approaches by incorporating the natural structure of various biological entities, such as cells, viruses, and bacteria. Biomimetic nanovaccines offer the benefit of targeted antigen-presenting cell (APC) delivery, improved antigen/adjuvant loading, and biocompatibility, thereby improving the sensitivity of immunotherapy. This review presents a comprehensive overview of several kinds of biomimetic nanovaccines in anticancer immune response, including cell membrane-coated nanovaccines, self-assembling protein-based nanovaccines, extracellular vesicle-based nanovaccines, natural ligand-modified nanovaccines, artificial antigen-presenting cells-based nanovaccines and liposome-based nanovaccines. We also discuss the perspectives and challenges associated with the clinical translation of emerging biomimetic nanovaccine platforms for sensitizing cancer cells to immunotherapy.

New uracil analog as inhibitor/modulator of ABC transporters or/and NF-κB in taxol-resistant MCF-7/Tx cell line

PURPOSE

The global increase in breast cancer cases necessitates ongoing exploration of advanced therapies. Taxol (Tx), an initial breast cancer treatment, induces mitotic arrest but faces limitations due to side effects and the development of resistance. Addressing Tx resistance involves understanding the complex molecular mechanisms, including alterations in tubulin dynamics, NF-κB signaling, and overexpression of ABC transporters (ABCB1 and ABCG2), leading to multidrug resistance (MDR).

METHODS

Real-time PCR and ELISA kits were used to analyze ABCB1, ABCG2 and NF-κB gene and protein expression levels, respectively. An MDR test assessed the resistance cell phenotype.

RESULTS

MCF-7/Tx cells exhibited a 24-fold higher resistance to Tx. Real-time PCR and ELISA analysis revealed the upregulation of ABCB1, ABCG2, and NF-κB. U-359 significantly downregulated both ABCB1 and ABCG2 gene and protein levels. Co-incubation with Tx and U-359 further decreased the mRNA and protein expression of these transporters. The MDR test indicated that U-359 increased MDR dye retention, suggesting its potential as an MDR inhibitor. U-359 and Tx, either individually or combined, modulated NF-κBp65 protein levels.

CONCLUSION

The development of a Taxol-resistant MCF-7 cell line provided valuable insights. U-359 demonstrated effectiveness in reducing the expression of ABC transporters and NF-κB, suggesting a potential solution for overcoming multidrug resistance in breast cancer cells. The study recommends a strategy to enhance the sensitivity of cancer cells to chemotherapy by integrating U-359 with traditional drugs.

XCR1: A promising prognostic marker that pinpoints targeted and immune-based therapy in hepatocellular carcinoma

Objectives

The lymphotactin receptor X-C motif chemokine receptor 1 (XCR1) is an essential member of the chemokine receptor family and is related to tumor development and progression. Nevertheless, further investigation is required to explore its expression patterns, prognostic values, and functions related to target or immune therapies in patients with hepatocellular carcinoma (HCC).

Materials and methods

The differential expression patterns of XCR1 and its prognostic influences were performed through The Cancer Genome Atlas (TCGA) and International Cancer Genome Consortium (ICGC) databases. Subsequently, immunohistochemistry (IHC) staining and univariate and multivariate Cox regressions were performed to validate the prognostic values in different subgroups. Furthermore, the potential roles of XCR1 in predicting target and immune therapeutic responses were also investigated.

Results

Increased expression level of XCR1 was associated with favorable overall survival (OS) and recurrence-free survival (RFS). Subgroup analysis revealed that a high expression level of XCR1 or positive immune cell proportion score (iCPS) were associated with favorable OS in the HCC patients with favorable tumor characteristics. In addition, the enhanced XCR1 expression was associated with the tumor environment scores, immune cell infiltration levels, and the expression levels of immune checkpoint genes. Further analysis revealed that improved expression of XCR1 was linked to better OS and RFS in HCC patients who received sorafenib.

Conclusion

This study identified that XCR1 is a valuable prognostic biomarker in the HCC population, especially in those with favorable tumor characteristics. The combination of iCPS status and BCLC status has a synergistic effect on stratifying patients' OS and RFS. Further analyses showed that XCR1 has the potential ability to predict treatment responses to sorafenib and immune-based therapies.

Novel pyxinol amide derivatives bearing an aliphatic heterocycle as P-glycoprotein modulators for overcoming multidrug resistance

P-glycoprotein (Pgp) modulators are promising agents for overcoming multidrug resistance (MDR) in cancer chemotherapy. In this study, via structural optimization of our lead compound S54 (nonsubstrate allosteric inhibitor of Pgp), 29 novel pyxinol amide derivatives bearing an aliphatic heterocycle were designed, synthesized, and screened for MDR reversal activity in KBV cells. Unlike S54, these active derivatives were shown to transport substrates of Pgp. The most potent derivative 4c exhibited promising MDR reversal activity (IC50 of paclitaxel = 8.80 ± 0.56 nM, reversal fold = 211.8), which was slightly better than that of third-generation Pgp modulator tariquidar (IC50 of paclitaxel = 9.02 ± 0.35 nM, reversal fold = 206.6). Moreover, the cytotoxicity of this derivative was 8-fold lower than that of tariquidar in human normal HK-2 cells. Furthermore, 4c blocked the efflux function of Pgp and displayed high selectivity for Pgp but had no effect on its expression and distribution. Molecular docking revealed that 4c bound preferentially to the drug-binding domain of Pgp. Overall, 4c is a promising lead compound for developing Pgp modulators.

Reversal of Chemoresistance via Staged Liberation of Chemodrug and siRNA in Hierarchical Response to ROS Gradient

P-glycoprotein (P-gp)-mediated multidrug resistance (MDR) often leads to the failure of antitumor chemotherapy, and codelivery of chemodrug with P-gp siRNA (siP-gp) represents a promising approach for treating chemoresistant tumors. To maximize the antitumor efficacy, it is desired that the chemodrug be latently released upon completion of siP-gp-mediated gene silencing, which however, largely remains an unmet demand. Herein, core-shell nanocomplexes (NCs) are developed to overcome MDR via staged liberation of siP-gp and chemodrug (doxorubicin, Dox) in hierarchical response to reactive oxygen species (ROS) concentration gradients. The NCs are constructed from mesoporous silica nanoparticles (MSNs) surface-decorated with cRGD-modified, PEGylated, ditellurium-crosslinked polyethylenimine (RPPT), wherein thioketal-linked dimeric doxorubicin (TK-Dox2) and photosensitizer are coencapsulated inside MSNs while siP-gp is embedded in the RPPT polymeric layer. RPPT with ultrahigh ROS-sensitivity can be efficiently degraded by the low-concentration ROS inside cancer cells to trigger siP-gp release. Upon siP-gp-mediated gene silencing and MDR reversal, light irradiation is performed to generate high-concentration, lethal amount of ROS, which cleaves thioketal with low ROS-sensitivity to liberate the monomeric Dox. Such a latent release profile greatly enhances Dox accumulation in Dox-resistant cancer cells (MCF-7/ADR) in vitro and in vivo, which cooperates with the generated ROS to efficiently eradicate MCF-7/ADR xenograft tumors.

Prospects of focal adhesion kinase inhibitors as a cancer therapy in preclinical and early phase study

INTRODUCTION

FAK, a nonreceptor cytoplasmic tyrosine kinase, plays a crucial role in tumor metastasis, drug resistance, tumor stem cell maintenance, and regulation of the tumor microenvironment. FAK has emerged as a promising target for tumor therapy based on both preclinical and clinical data.

AREAS COVERED

This paper aims to summarize the molecular mechanisms underlying FAK's involvement in tumorigenesis and progression. Encouraging results have emerged from ongoing clinical trials of FAK inhibitors. Additionally, we present an overview of clinical trials for FAK inhibitors, examining their potential as promising treatments. The pertinent studies gathered from databases including PubMed, ClinicalTrials.gov.

EXPERT OPINION

Since the first finding in 1990s, targeting FAK has became the focus of interests in many pharmaceutical companies. Through 30 years' discovery, the industry and academy gradually realized the features of FAK target which may not be a driver gene but a solid defense system for the cancer initiation and development. Currently, the ongoing clinical regimens involving FAK inhibition are all the combination strategies in which FAK inhibitors can further strengthen the cancer cell killing effects of other testing agents. The emerging positive signal in clinical trials foresee targeting FAK as class will be an effective mean to fight against cancers.