Anticancer Research Articles

Phenylboronic Acid‐Functionalized Hyaluronic Acid as Polysaccharide Carriers for Diol‐Containing Drugs Delivery

Packaging hydrophobic drugs into polysaccharide carriers can improve their aqueous solubility, biocompatibility, tumor‐specific accumulation, and therapeutic effect. In this work, phenylboronic acid (PBA) was anchored onto the chain of biocompatible polysaccharide hyaluronic acid (HA) by an amide condensation reaction, which could be used to fabricate stimuli‐responsive targeted drug delivery systems. A series of pH‐responsive conjugated hyaluronic acid nanoparticles composed of a hydrophobic drug core and hydrophilic hyaluronic acid shell were prepared by the boronate‐crosslink of the PBA with diol‐containing anticancer drugs such as capecitabine (CAPE) and aloin (Al). Satisfactory targeted drug release behavior at acidic pH, lower cytotoxicity, and higher anticancer effect were realized by using this polysaccharide carrier. It is believed that this strategy has great potential for polysaccharide modification and anticancer‐associated applications.

Involvement of the gut microbiota in cancer cachexia.

Cancer cachexia, or the unintentional loss of body weight in cancer patients, is a multi-organ and multi-factorial syndrome with a complex and largely unknown etiology; however, metabolic dysfunction and inflammation remain hallmarks of cancer-associated wasting. While cachexia manifests with muscle and adipose tissue loss, perturbations to the gastrointestinal tract may serve as the front line for both impaired nutrient absorption and immune activating gut dysbiosis. Investigations into the gut microbiota have exploded within the past 2 decades, demonstrating multiple gut-tissue axes; however, the link between adipose and skeletal muscle wasting and the gut microbiota with cancer is only beginning to be understood. Further, the most used anti-cancer drugs (e.g. chemotherapy, immune checkpoint inhibitors) negatively impact gut homeostasis, potentially exacerbating wasting and contributing to poor patient outcomes and survival. In this current review, we 1) highlight our current understanding of the microbial changes that occur with cachexia, 2) discuss how microbial changes may contribute to adipose and skeletal muscle wasting, and 3) outline study design considerations needed when examining the role of the microbiota in cancer-induced cachexia.

Role of Cytochrome P450 3A4 in Cancer Drug Resistance: Challenges and Opportunities.

One of the biggest obstacles to the treatment of diseases, particularly serious conditions like cancer, is therapeutic resistance. The process of drug resistance is influenced by a number of important variables, including MDR genes, drug efflux, low-quality medications, inadequate dosage, etc. Drug resistance must be addressed, and new combinations based on the pharmacokinetics/pharmacodynamics (PK-PD) characteristics of the partner pharmaceuticals must be developed in order to extend the half-lives of already available medications. The primary mechanism of drug elimination is hepatic biotransformation of medicines by cytochrome P450 (CYP) enzymes; of these CYPs, CYP3A4 makes up 30-40% of all known cytochromes that metabolize medications. Induction or inhibition of CYP3A4-mediated metabolism affects the pharmacokinetics of most anticancer drugs, but these details are not fully understood and highlighted because of the complexity of tumor microenvironments and various influencing patient related factors. The involvement of CYPs, particularly CYP3A4 and other drug-metabolizing enzymes, in cancer medication resistance will be covered in the current review.

Phenylboronic Acid‐Functionalized Hyaluronic Acid as Polysaccharide Carriers for Diol‐Containing Drugs Delivery

Packaging hydrophobic drugs into polysaccharide carriers can improve their aqueous solubility, biocompatibility, tumor‐specific accumulation, and therapeutic effect. In this work, phenylboronic acid (PBA) was anchored onto the chain of biocompatible polysaccharide hyaluronic acid (HA) by an amide condensation reaction, which could be used to fabricate stimuli‐responsive targeted drug delivery systems. A series of pH‐responsive conjugated hyaluronic acid nanoparticles composed of a hydrophobic drug core and hydrophilic hyaluronic acid shell were prepared by the boronate‐crosslink of the PBA with diol‐containing anticancer drugs such as capecitabine (CAPE) and aloin (Al). Satisfactory targeted drug release behavior at acidic pH, lower cytotoxicity, and higher anticancer effect were realized by using this polysaccharide carrier. It is believed that this strategy has great potential for polysaccharide modification and anticancer‐associated applications.

Investigating the impact of 2-OHOA-embedded liposomes on biophysical properties of cancer cell membranes via Laurdan two-photon microscopy imaging

2-Hydroxyoleic acid (2-OHOA) has gained attention as a membrane lipid therapy (MLT) anti-cancer drug. However, in the viewpoint of anti-cancer drug, 2-OHOA shows poor water solubility and its effectiveness still has space for improvement. Thus, this study aimed to overcome the problems by formulating 2-OHOA into liposome dosage form. Furthermore, in the context of MLT reagents, the influence of 2-OHOA on the biophysical properties of the cytoplasmic membrane remains largely unexplored. To bridge this gap, our study specifically focused the alterations in cancer cell membrane fluidity and lipid packing characteristics before and after treatment. By using a two-photon microscope and the Laurdan fluorescence probe, we noted that liposomes incorporating 2-OHOA induced a more significant reduction in cancer cell membrane fluidity, accompanied by a heightened rate of cellular apoptosis when compared to the non-formulated 2-OHOA. Importantly, the enhanced efficacy of 2-OHOA within the liposomal formulation demonstrated a correlation with its endocytic uptake mechanism. In conclusion, our findings underscore the significant influence of 2-OHOA on the biophysical properties of cancer plasma membranes, emphasizing the potential of liposomes as an optimized delivery system for 2-OHOA in anti-cancer therapy.

Targeting ROS in cancer: rationale and strategies.

Reactive oxygen species (ROS) in biological systems are transient but essential molecules that are generated and eliminated by a complex set of delicately balanced molecular machineries. Disruption of redox homeostasis has been associated with various human diseases, especially cancer, in which increased ROS levels are thought to have a major role in tumour development and progression. As such, modulation of cellular redox status by targeting ROS and their regulatory machineries is considered a promising therapeutic strategy for cancer treatment. Recently, there has been major progress in this field, including the discovery of novel redox signalling pathways that affect the metabolism of tumour cells as well as immune cells in the tumour microenvironment, and the intriguing ROS regulation of biomolecular phase separation. Progress has also been made in exploring redox regulation in cancer stem cells, the role of ROS in determining cell fate and new anticancer agents that target ROS. This Review discusses these research developments and their implications for cancer therapy and drug discovery, as well as emerging concepts, paradoxes and future perspectives.

Targeting ROS in cancer: rationale and strategies.

Reactive oxygen species (ROS) in biological systems are transient but essential molecules that are generated and eliminated by a complex set of delicately balanced molecular machineries. Disruption of redox homeostasis has been associated with various human diseases, especially cancer, in which increased ROS levels are thought to have a major role in tumour development and progression. As such, modulation of cellular redox status by targeting ROS and their regulatory machineries is considered a promising therapeutic strategy for cancer treatment. Recently, there has been major progress in this field, including the discovery of novel redox signalling pathways that affect the metabolism of tumour cells as well as immune cells in the tumour microenvironment, and the intriguing ROS regulation of biomolecular phase separation. Progress has also been made in exploring redox regulation in cancer stem cells, the role of ROS in determining cell fate and new anticancer agents that target ROS. This Review discusses these research developments and their implications for cancer therapy and drug discovery, as well as emerging concepts, paradoxes and future perspectives.

Chrysin-loaded PEGylated liposomes protect against alloxan-induced diabetic neuropathy in rats: the interplay between endoplasmic reticulum stress and autophagy

BackgroundDiabetic neuropathy (DN) is recognized as a significant complication arising from diabetes mellitus (DM). Pathogenesis of DN is accelerated by endoplasmic reticulum (ER) stress, which inhibits autophagy and contributes to disease progression. Autophagy is a highly conserved mechanism crucial in mitigating cell death induced by ER stress. Chrysin, a naturally occurring flavonoid, can be found abundantly in honey, propolis, and various plant extracts. Despite possessing advantageous attributes such as being an antioxidant, anti-allergic, anti-inflammatory, anti-fibrotic, and anticancer agent, chrysin exhibits limited bioavailability. The current study aimed to produce a more bioavailable form of chrysin and discover how administering chrysin could alter the neuropathy induced by Alloxan in male rats.MethodsChrysin was formulated using PEGylated liposomes to boost its bioavailability and formulation. Chrysin PEGylated liposomes (Chr-PLs) were characterized for particle size diameter, zeta potential, polydispersity index, transmission electron microscopy, and in vitro drug release. Rats were divided into four groups: control, Alloxan, metformin, and Chr-PLs. In order to determine Chr- PLs’ antidiabetic activity and, by extension, its capacity to ameliorate DN, several experiments were carried out. These included measuring acetylcholinesterase, fasting blood glucose, insulin, genes dependent on autophagy or stress in the endoplasmic reticulum, and histopathological analysis.ResultsAccording to the results, the prepared Chr-PLs exhibited an average particle size of approximately 134 nm. They displayed even distribution of particle sizes. The maximum entrapment efficiency of 90.48 ± 7.75% was achieved. Chr-PLs effectively decreased blood glucose levels by 67.7% and elevated serum acetylcholinesterase levels by 40% compared to diabetic rats. Additionally, Chr-PLs suppressed the expression of ER stress-related genes (ATF-6, CHOP, XBP-1, BiP, JNK, PI3K, Akt, and mTOR by 33%, 39.5%, 32.2%, 44.4%, 40.4%, 39.2%, 39%, and 35.9%, respectively). They also upregulated the miR-301a-5p expression levels by 513% and downregulated miR-301a-5p expression levels by 65%. They also boosted the expression of autophagic markers (AMPK, ULK1, Beclin 1, and LC3-II by 90.3%, 181%, 109%, and 78%, respectively) in the sciatic nerve. The histopathological analysis also showed that Chr-PLs inhibited sciatic nerve degeneration.ConclusionThe findings suggest that Chr-PLs may be helpful in the protection against DN via regulation of ER stress and autophagy.Graphical

Association of leukopenia in the development of cancer chemotherapy‐induced oral mucositis and its severity

AbstractAimTo prevent oral mucositis, it is important to understand its associated risk factors, such as highly cytotoxic chemotherapeutic agents, sex, and low body weight. However, to the best of our knowledge, no study has investigated the association between chemotherapy‐induced myelosuppression and oral mucositis in Japan. In this study, we examined the relationship between chemotherapy‐induced leukopenia and the severity of oral mucositis.MethodsWe conducted a retrospective cohort study of patients who received oral care interventions during cancer chemotherapy. Hematological values were obtained at the initiation of chemotherapy and on the proximal day of changes in the grade (Gr) of oral mucositis. The Gr of oral mucositis was assessed by dentists and dental hygienists using the Common Terminology Criteria for Adverse Events (version 5.0).ResultsThe data of 79 patients were analyzed during the study period. The incidence of oral mucositis was 7/79 (8.9%). The incidences of grades 1–4 were 4/79 (5.1%), 2/79 (2.5%), 0/79 (0%), and 1/79 (1.3%), respectively. Notably, the incidence of oral mucositis was significantly higher in patients with lower white blood cell and neutrophil counts (p < 0.01). Logistic regression analysis further revealed that patients with Gr 2 or higher leukopenia had a significantly higher risk of developing Grade 2 or higher oral mucositis (adjusted odds ratio: 5.2; 95% confidence interval: 1.60–17.0; p = 0.0062).ConclusionCancer chemotherapy induced‐oral mucositis may be at great risk in patients with Gr 2 or higher leukopenia.

The current landscape of coumarin hybrids with antibreast cancer therapeutic applications: An updated review.

Globally, breast cancer (BC) has the highest prevalence among malignant diseases. BC is also the primary cause of death among women. Notably, BC morbidity has been increasing continuously at an approximate growth rate of 2.2% per year. Persistent BC is a major public health issue worldwide. Consequently, novel chemotherapeutic agents to combat this lethal disease should be developed urgently. Coumarins with interesting structural and mechanistic variations exhibit promising activity in several forms of BC, including BCs with multidrug resistance. In particular, coumarin hybrids composed of coumarin and one or more anti-BC pharmacophores can target different biological components in BC cells simultaneously. Thus, coumarin hybrids are useful scaffolds that can help improve the anti-BC efficacy of coumarins, reduce side effects, improve pharmacokinetics, minimize drug-drug interactions, and circumvent drug resistance. This review, in which articles published from 2020 to the present day have been evaluated, highlights the landscape of coumarin hybrids that exhibit therapeutic effects against breast cancer. These findings can aid further investigations on novel antibreast-cancer therapeutics.

Association of leukopenia in the development of cancer chemotherapy‐induced oral mucositis and its severity

AbstractAimTo prevent oral mucositis, it is important to understand its associated risk factors, such as highly cytotoxic chemotherapeutic agents, sex, and low body weight. However, to the best of our knowledge, no study has investigated the association between chemotherapy‐induced myelosuppression and oral mucositis in Japan. In this study, we examined the relationship between chemotherapy‐induced leukopenia and the severity of oral mucositis.MethodsWe conducted a retrospective cohort study of patients who received oral care interventions during cancer chemotherapy. Hematological values were obtained at the initiation of chemotherapy and on the proximal day of changes in the grade (Gr) of oral mucositis. The Gr of oral mucositis was assessed by dentists and dental hygienists using the Common Terminology Criteria for Adverse Events (version 5.0).ResultsThe data of 79 patients were analyzed during the study period. The incidence of oral mucositis was 7/79 (8.9%). The incidences of grades 1–4 were 4/79 (5.1%), 2/79 (2.5%), 0/79 (0%), and 1/79 (1.3%), respectively. Notably, the incidence of oral mucositis was significantly higher in patients with lower white blood cell and neutrophil counts (p < 0.01). Logistic regression analysis further revealed that patients with Gr 2 or higher leukopenia had a significantly higher risk of developing Grade 2 or higher oral mucositis (adjusted odds ratio: 5.2; 95% confidence interval: 1.60–17.0; p = 0.0062).ConclusionCancer chemotherapy induced‐oral mucositis may be at great risk in patients with Gr 2 or higher leukopenia.

Nano Based Thiazole as a Potent Anticancer Agent and its In-Silico Molecular Docking and ADMET Prediction Studies

Nano Based Thiazole as a Potent Anticancer Agent and its In-Silico Molecular Docking and ADMET Prediction Studies

Carbonnanotubes: New Chemotherapeutic Drug Delivery Systems for Targeted Cancer Treatments

The complexity of the management of cancerous conditions requires innovative strategies, including the pharmacotechnical optimization of treatments. The improvement of galenic forms, or more generally of drug delivery, represents a rapidly developing area of research, particularly in oncology, in order to remedy side effects and drug resistance remains a worrying problem. Carbon nanotubes CNTs consist of thin sheets of benzene carbons coiled into a seamless tubular structure. These CNTs have remarkable size and surface properties that make them the ideal vehicle for targeted and selective drug delivery. Different in vitro and in vivo experiments have proven that these particles can be easily modified in such a way that the chemical drug can be delivered directly to the tumor site. Additionally, different types of ligands can be loaded on the surface of CNTs to improve selectivity or modulate drug release. On the other hand, advances in carbon nanotubes could well lead to a more effective understanding of biological and physicochemical processes. This will make it possible to find compounds more compatible with carbon nanotube technology and facilitate their use.

Parecoxib and 5-Fluorouracil Synergistically Inhibit EMT and Subsequent Metastasis in Colorectal Cancer by Targeting PI3K/Akt/NF-κB Signaling

Colorectal cancer is one of the most common causes of cancer mortality worldwide, and innovative drugs for the treatment of colorectal cancer are continually being developed. 5-Fluorouracil (5-FU) is a common clinical chemotherapeutic drug. Acquired resistance to 5-FU is a clinical challenge in colorectal cancer treatment. Parecoxib is a selective COX-2-specific inhibitor that was demonstrated to inhibit metastasis in colorectal cancers in our previous study. This study aimed to investigate the synergistic antimetastatic activities of parecoxib to 5-FU in human colorectal cancer cells and determine the underlying mechanisms. Parecoxib and 5-FU synergistically suppressed metastasis in colorectal cancer cells. Treatment with the parecoxib/5-FU combination induced an increase in E-cadherin and decrease in β-catenin expression. The parecoxib/5-FU combination inhibited MMP-9 activity, and the NF-κB pathway was suppressed as well. Mechanistic analysis denoted that the parecoxib/5-FU combination hindered the essential molecules of the PI3K/Akt route to obstruct metastatic colorectal cancer. Furthermore, the parecoxib/5-FU combination could inhibit reactive oxygen species. Our work showed the antimetastatic capacity of the parecoxib/5-FU combination for treating colorectal cancers via the targeting of the PI3K/Akt/NF-κB pathway.

Parecoxib and 5-Fluorouracil Synergistically Inhibit EMT and Subsequent Metastasis in Colorectal Cancer by Targeting PI3K/Akt/NF-κB Signaling

Colorectal cancer is one of the most common causes of cancer mortality worldwide, and innovative drugs for the treatment of colorectal cancer are continually being developed. 5-Fluorouracil (5-FU) is a common clinical chemotherapeutic drug. Acquired resistance to 5-FU is a clinical challenge in colorectal cancer treatment. Parecoxib is a selective COX-2-specific inhibitor that was demonstrated to inhibit metastasis in colorectal cancers in our previous study. This study aimed to investigate the synergistic antimetastatic activities of parecoxib to 5-FU in human colorectal cancer cells and determine the underlying mechanisms. Parecoxib and 5-FU synergistically suppressed metastasis in colorectal cancer cells. Treatment with the parecoxib/5-FU combination induced an increase in E-cadherin and decrease in β-catenin expression. The parecoxib/5-FU combination inhibited MMP-9 activity, and the NF-κB pathway was suppressed as well. Mechanistic analysis denoted that the parecoxib/5-FU combination hindered the essential molecules of the PI3K/Akt route to obstruct metastatic colorectal cancer. Furthermore, the parecoxib/5-FU combination could inhibit reactive oxygen species. Our work showed the antimetastatic capacity of the parecoxib/5-FU combination for treating colorectal cancers via the targeting of the PI3K/Akt/NF-κB pathway.

Andrographis paniculata Ethanolic Extract Improved Doxorubicin-induced Cardiac Inflammation, Alterations in Liver Function Parameters and Anemia

Background: Doxorubicin (DOX), an efficacious chemotherapy drug is compromised by cardiotoxicity, myelosuppression, and hepatotoxicity. Due to the limited success of current treatments for DOX toxicity, there is a pressing need to explore alternative medical interventions, particularly from plant sources. This study was conducted to investigate the potential protective effect of ethanolic extract of Andrographis paniculata leaves (EEAP) against DOX-induced cardiac inflammation, liver toxicity, and anemia.Materials and methods: Sprague-Dawley rats were intraperitoneally injected with DOX at a total dose of 16 mg/kgBW. EEAP was administered orally for 4 weeks at doses of 125, 250, and 500 mg/kgBW/day according to the assigned treatment groups. The mRNA expression levels of interleukin-1β (IL-1β) and nucleotide-binding domain, leucine-rich-containing family, pyrin domain-containing-3 (NLRP3) in the heart tissue, along with the concentrations of nuclear factor kappa-light-chain-enhancer of activated B cells (NFκB) and calcium level were examined. Additionally, the hematological parameters (including hematocrit, hemoglobin and red blood cells (RBCs)), aspartate aminotransferase (AST), alanine transaminase (ALT), alkaline phosphatase (ALP), and malondialdehyde (MDA) levels in blood were also analyzed.Results: EEAP dose-dependently decreased the mRNA expressions of IL-1β (p<0.05), tended to decrease mRNA expression of NLRP3 and the concentrations of NFκB and calcium in heart tissue compared with the DOX-only group. Additionally, EEAP dose-dependently decreased ALP values (p<0.0001) and tended to improve hematological parameters, as well as AST and MDA levels in serum.Conclusion: This extract may prevent DOX-induced cardiac inflammation, anemia, and hepatotoxicity. However, further studies are needed to confirm these findings, including the efficacy profile of the extract in cancer rats treated with DOX.Keywords: doxorubicin, Andrographis paniculata, inflammation, anemia, hepatotoxicity, herbal medicine

Functionalised Ligand-Based Nanomaterial Drug Targeting Approaches for Colorectal Cancer Therapy

Cancer refers to a condition in which abnormal cells uncontrollably divide, resulting in the destruction of tissues. In colorectal cancer, uncontrolled cell proliferation takes place in the rectum or colon. Most colorectal tumors start as adenomas, a form of polyp that can develop into cancer within the rectum or colon. Symptoms of colorectal cancer include chronic diarrhea or constipation, bleeding from the rectum, bloody stools, change in appetite, weight loss, etc. Risk factors associated with colorectal cancer are smoking, obesity, and low physical activity. Colorectal cancer can be treated depending on size, location, and the spread of the cancer. Treatment includes surgery where the lymph node is dissected and a colectomy is performed. Chemotherapy and radiation therapies are other treatment options, but the main disadvantage is that these treatments have nonspecific avenues. Apart from killing cancerous cells, they damage healthy cells, too. Therefore, with the help of nanotechnology, drug-containing nanoparticles can be created with the aid of nanocarriers, which are stronger, more durable, and site-specific. The cancerous cells can be actively targeted by formulating nanoparticles loaded with anticancer drugs and functionalising the surface by either attaching ligands (peptides, antibodies, and small molecules) or targeting molecules towards receptors that are present on the exterior surface of the cancerous cells. These surfaces functionalised nanoparticles, loaded with anticancer drugs, are significantly upregulated in cancerous cells in contrast to healthy surrounding cells and tissues. This review article is focused on ligand-based drugs targeting colorectal tumours.

Surface Modification of Mesoporous Silica Nanoparticles as a Means to Introduce Inherent Cancer‐Targeting Ability in a 3D Tumor Microenvironment

Mesoporous silica nanoparticles (MSNs) have emerged as promising drug carriers that can facilitate targeted anticancer drug delivery, but efficiency studies relying on active targeting mechanisms remain elusive. This study implements in vitro 3D cocultures, so‐called microtissues, to model a physiologically relevant tumor microenvironment (TME) to examine the impact of surface‐modified MSNs without targeting ligands on the internalization, cargo delivery, and cargo release in tumor cells and cancer‐associated fibroblasts. Among these, acetylated MSNs most effectively localized in tumor cells in a 3D setting containing collagen, while other MSNs did so to a lesser degree, most likely due to remaining trapped in the extracellular matrix of the TME. Confocal imaging of hydrophobic model drug‐loaded MSNs demonstrated effective cargo release predominantly in tumor cells, both in 2D and 3D cocultures. MSN‐mediated delivery of an anticancer drug in the microtissues exhibited a significant reduction in tumor organoid size and enhanced the tumor‐specific cytotoxic effects of a γ‐secretase inhibitor, compared to the highly hydrophobic drug in free form. This inherent targeting potential suggests reduced off‐target effects and increased drug efficacy, showcasing the promise of surface modification of MSNs as a means of direct cell‐specific targeting and delivery for precise and successful targeted drug delivery.

Surface Modification of Mesoporous Silica Nanoparticles as a Means to Introduce Inherent Cancer‐Targeting Ability in a 3D Tumor Microenvironment

Mesoporous silica nanoparticles (MSNs) have emerged as promising drug carriers that can facilitate targeted anticancer drug delivery, but efficiency studies relying on active targeting mechanisms remain elusive. This study implements in vitro 3D cocultures, so‐called microtissues, to model a physiologically relevant tumor microenvironment (TME) to examine the impact of surface‐modified MSNs without targeting ligands on the internalization, cargo delivery, and cargo release in tumor cells and cancer‐associated fibroblasts. Among these, acetylated MSNs most effectively localized in tumor cells in a 3D setting containing collagen, while other MSNs did so to a lesser degree, most likely due to remaining trapped in the extracellular matrix of the TME. Confocal imaging of hydrophobic model drug‐loaded MSNs demonstrated effective cargo release predominantly in tumor cells, both in 2D and 3D cocultures. MSN‐mediated delivery of an anticancer drug in the microtissues exhibited a significant reduction in tumor organoid size and enhanced the tumor‐specific cytotoxic effects of a γ‐secretase inhibitor, compared to the highly hydrophobic drug in free form. This inherent targeting potential suggests reduced off‐target effects and increased drug efficacy, showcasing the promise of surface modification of MSNs as a means of direct cell‐specific targeting and delivery for precise and successful targeted drug delivery.

A pan-cancer analysis unveiling the function of NR4A family genes in tumor immune microenvironment, prognosis, and drug response.

NR4A family genes play crucial roles in cancers. However, the role of NR4A family genes in cancers remains paradoxical as they promote or suppress tumorigenesis. We aimed to conduct comprehensive analyses of the association between the expression of NR4A family genes and tumor microenvironment (TME) based on bioinformatics methods. We collected RNA-seq data from 33 cancer types and 20 normal tissue sites from the TCGA and GTEx databases. Expression patterns of NR4A family genes and their associations with DNA methylation, miRNA, overall survival, drug responses, and tumor microenvironment were investigated. Significant downregulation of all NR4A family genes was observed in 15 cancer types. DNA promoter methylation and expression of NR4A family genes were negatively correlated in five cancers. The expression of 10 miRNAs targeting NR4A family genes was negatively correlated with the expression of NR4A family genes. High expression of all NR4A family genes was associated with poor prognosis in stomach adenocarcinoma and increased expressions of NR4A2 and NR4A3 were associated with poor prognosis in adrenocortical carcinoma. In addition, we found an elevated expression of NR4A2, which enhances the response to various chemotherapeutic drugs, whereas NR4A3 decreases drug sensitivity. Interestingly, in breast cancer, NR4A3 was significantly associated with C2 (IFN-γ dominant), C3 (inflammatory), and C6 (TGF-β dominant) immune subtypes and infiltrated immune cell types, implying both oncogenic and tumor-suppressive functions of NR4A3 in breast cancer. The NR4A family genes have the potential to serve as a diagnostic, prognostic, and immunological marker of human cancers.