Tripartite motif family - its role in tumor progression and therapy resistance: a review.

PURPOSE OF REVIEW: In this review, we summarized published articles on the role of tripartite motif (TRIM) family members in the initiation and development of human malignancies. RECENT FINDINGS: The ubiquitin-proteasome system (UP-S) plays a critical role in cellular activities, and UP-S dysregulation contributes to tumorigenesis. One of the key regulators of the UP-S is the tripartite motif TRIM protein family, most of which are active E3 ubiquitin ligases. TRIM proteins are critical for the biological functions of cancer cells, including migration, invasion, metastasis, and therapy resistance. Therefore, it is important to understand how TRIM proteins function at the molecular level in cancer cells. SUMMARY: We provide a comprehensive and up-to-date overview about the role TRIMs play in cancer progression and therapy resistance. We propose TRIM family members as potential new markers and targets to overcome therapy failure.

Ring-Opening Oligomerization Mechanism of a Vanillin-Furfurylamine-Based Benzoxazine and a Mono-Azomethine Derivative.

Exploring the ring-opening polymerization (ROP) mechanism of benzoxazines is a fundamental issue in benzoxazine chemistry. Though some research papers on the topic have been reported, the ROP mechanism of mono-benzoxazines is still elusive. The key point for mechanistic studies is to determine and characterize the structure and formation pathways of the products generated in ROP. In this paper, the ROP of a vanillin-furfurylamine-based benzoxazine and a mono-azomethine derivative is studied with differential scanning calorimetry, fourier transform infrared spectroscopy, nuclear magnetic resonance, and electrospray ionization mass spectrometry, respectively. The results show that the products consist of a range of cationic species, zwitterions, fragments, and series of cyclic and linear oligomers of varying molecular sizes. It is proposed that both mono-benzoxazines undergo thermally activated cationic ring-opening oligomerization via zwitterion intermediates. Upon thermal induction, multi-bond-cleavage takes place to form various zwitterionic intermediates, which react with a monomer, a fragment, or a second zwitterion by several pathways to generate cyclic and linear oligomers.

A Fluorescent Probe for Investigating the Role of Biothiols in Signaling Pathways Associated with Cerebral Ischemia-Reperfusion Injury.

Cerebral ischemia-reperfusion injury (CIRI) is intimately associated with the redox regulation of biothiol, a crucial antioxidant marker that precludes the onset of ROS. We designed a novel fluorescent probe, DCI-Ac-Py, showing various physicochemical properties, such as high selectivity, exceptional signal-to-noise ratio, near-infrared (NIR) optical window, and blood-brain barrier (BBB) penetrability, for detecting biothiols in the brain. The picolinate serves as a specific recognition group that is rapidly activated by biothiol and undergoes nucleophilic substitution with the adjacent acrylic ester to yield the desired NIR probe. Additionally, the probe's lipid solubility is improved through the inclusion of halogen atoms, which aids in penetrating the BBB. Using DCI-Ac-Py, we investigated changes of biothiols in vivo in the brains of mice during CIRI. We found that biothiol-mediated NF-kB classical (P65-related) and nonclassical (RelB-related) pathways contribute to abundant ROS production induced by CIRI and that biothiols are involved in redox regulation. These findings provide new insights into the study of CIRI and shed light on the physiological and pathological mechanisms of biothiols in the brain.

Synergistic Modulation by Halogens and Pyridine Crossing the Blood-Brain Barrier for In Situ Visualization of Thiol Flux in the Epileptic Brain.

Epilepsy is a nervous system disease, and seizures are closely related to oxidative stress. Thiols, as the main antioxidant in an organism, play a key role in regulating the redox balance and defending from oxidative stress. As a result of the complexity of the brain structure, there is still a lack of suitable in situ detection methods of thiols to reveal the relationship between epilepsy and thiol level fluctuations. Therefore, by combining picolinate as the new recognition site for thiols, parallel synthesis, and the fluorescence rapid screening method, DCI-Br-3 was developed as a rapid, highly sensitive, and selective probe to monitor thiols in vitro and in vivo. It is worth noting that DCI-Br-3 effectively crossed the blood-brain barrier (BBB) to reveal the negative relationship between the level of thiols and the occurrence of epilepsy and may further provide important information for the prevention and treatment of thiol-related neurological diseases.

Drug Release from Disulfide-Linked Prodrugs: Role of Thiol Agents.

The disulfide bond (SS) has been widely used in prodrugs for the redox-responsive drug release, but its drug release mechanism and rate were seldom compared in different thiol agents. Herein, self-assembling nanoaggregates (NAs) formed by camptothecin (CPT)-oleic acid (OA) prodrugs linked by two frequently used SS linkers (ETCSS and ACSS) were used for such comparative investigation. It is found that the cleavage of ETCSS was directly coupled with CPT release, whereas the breakage of ACSS resulted in the generation of CPT intermediates, the chemical stability of which determined CPT release. In both cases, the redox-responsive drug release was highly dependent on the reactivity between SS and thiol agents, with an order of dithiothreitol > cysteine ≈ glutathione. Moreover, the presence of SS significantly accelerated the extracellular CPT release, which was around 3-4 fold higher than intracellular CPT release. Therefore, the in vitro cytotoxicity of SS-linked CPT-OA NAs could not be ascribed to the glutathione-trigged intracellular drug release but rather to the SS-accelerated extracellular CPT release. The above results would effectively guide the rational design and evaluation of SS-linked prodrug NAs for efficient drug delivery.

Hypoxia-Activated and Indomethacin-Mediated Theranostic Prodrug Releasing Drug On-Demand for Tumor Imaging and Therapy.

A smart theranostic prodrug IMC-FDU-TZBC-NO2, releasing active drug on-demand based on hypoxia-activated and indomethacin-mediated, for solid tumor imaging and efficient therapy was designed. This prodrug was constructed by conjugating chemotherapy drug 5-fluoro-2-deoxyuridine (FDU), targeting moiety indomethacin (IMC), and the hypoxic trigger 4-nitrobenzyl group to a fluorescent dye precursor, which was mediated by IMC and activated by NTR under hypoxic conditions. The fluorescent dye IMC-TZBCM was generated and FDU was released at the same time in tumor cells. The rates and amounts of FDU release and IMC-TZBCM generation were regulated by hypoxia status, and increased with increasing degree of hypoxia. Nevertheless, it is "locked" in normal cells. It combined the advantages of tumor targeting, diagnosis, and chemotherapy functions, showed excellent targeting ability to cancer cells, excellent stability in physiological conditions, high cellular uptake efficiency, and on-demand drug release behavior. The in vitro and in vivo assays demonstrated that IMC-FDU-TZBC-NO2 exhibits enhanced anticancer potency and low side effects. The novel targeted theranostic prodrug activated by hypoxia shows a great potential in cancer therapy.

Discovery of novel (+)-Usnic acid derivatives as potential anti-leukemia agents with pan-Pim kinases inhibitory activity.

Usnic acid (UA) is the main secondary metabolite isolated from lichens, with moderate anticancer activity. A small group of (+)-UA derivatives characterized with flavanone moiety was designed and synthesized, and their anticancer activities were evaluated in leukemia cells. It was demonstrated that (+)-UA derivatives 6a-6g inhibited the proliferation of leukemia cells HL-60 and K562 with low micromolar IC50 values. Mechanisms of action were investigated to find that 6g induced apoptosis in HL-60 and K562 cell lines, and affected the expression of MNK/eIF4E axis-related proteins, such as Mcl-1, p-eIF4E, p-4E-BP1. Finally, kinase inhibition assay suggested 6g was a potential inhibitor of pan-Pim kinases. Meanwhile, the blocking of phosphorylation of BAD and 4E-BP1 by 6g, together with the proposed binding mode of 6g with Pim-1 further confirmed its Pim inhibition effects. Our finding provides the sight towards the potential mechanism of (+)-UA derivatives 6g as anti-leukemia agents.

Degradation of the phenolic ß-ether lignin model dimer and dyes by dye-decolorizing peroxidase from Bacillus amyloliquefaciens.

OBJECTIVE: The dye-decolorizing peroxidase from Bacillus amyloliquefaciens, BaDyP, was identified to be an efficient catalyst for the degradation of phenolic ß-ether lignin model dimer guaiacylglycerol-ß-guaiacyl ether (GGE) and dyes. RESULTS: Efeb gene encoding BaDyP from B. amyloliquefaciens MN-13 consisted of 1257 bp and the open reading frame encoded 418 amino acids. The efeb gene was expressed in Escherichia coli BL21 and a recombinant BaDyP of 50 kDa was achieved. The BaDyP exhibited activity in oxidizing GGE and decolorizing azo and triphenylmethane dyes. At pH 4.5 and 30 °C the BaDyP not only completely degraded GGE by the cleavage of ß-O-4 ether bond and Cα-Cß bond, and Cα oxidation without any oxidative mediator, but also decolorized four synthetic dyes, including congo red, bromine cresol green, eriochrome black T and crystal violet. This was achieved with decolorization rates of 65.7%, 70.62%, 80.06% and 62.09%, respectively, after 72 h of incubation. CONCLUSIONS: BaDyP was identified as a bacteria peroxidase with great potential for the degradation of lignin and bioremediation of dye-contamination.

Structure-Based Design of Novel Benzimidazole Derivatives as Pin1 Inhibitors.

Peptidyl-prolyl cis/trans isomerase Pin1 plays a key role in amplifying and translating multiple oncogenic signaling pathways during oncogenesis. The blockade of Pin1 provided a unique way of disrupting multiple oncogenic pathways and inducing apoptosis. Aiming to develop potent Pin1 inhibitors, a series of benzimidazole derivatives were designed and synthesized. Among the derivatives, compounds 6h and 13g showed the most potent Pin1 inhibitory activity with IC50 values of 0.64 and 0.37 µM, respectively. In vitro antiproliferative assay demonstrated that compounds 6d, 6g, 6h, 6n, 6o and 7c exhibited moderate antiproliferative activity against human prostate cancer PC-3 cells. Taken together, these unique benzimidazole derivatives exhibited great potential to be further explored as potent Pin1 inhibitors with improved potency.

Hypoxia-Activated Anticancer Prodrug for Bioimaging, Tracking Drug Release, and Anticancer Application.

A novel anticancer theranostic prodrug, FDU-DB-NO2, specifically activated by hypoxia for selective two-photon imaging hypoxia status, real-time tracking drug release, and solid tumor therapy was designed. The devised prodrug consists of an anticancer drug floxuridine (FDU), a fluorescence dye precursor 4'-(diethylamino)-1,1'-biphenyl-2-carboxylate (DB), and a hypoxic trigger 4-nitrobenzyl group. In normal cells, FDU-DB-NO2 is "locked". Whereas in tumor cells, the prodrug is "unlocked" by hypoxia and results in fluorescent dye 7-(diethylamino)coumarin (CM) generation along with FDU release. The amounts and rates of CM formation and FDU release were controlled by hypoxic status and increased with the decreasing of the O2 concentration. The hypoxic status, distribution of oxygen, and amount of FDU release in tumor cells, spheroids, and tumor tissue could be visualized by fluorescence. FDU-DB-NO2 showed high cytotoxicity against hypoxic MCF-7 and MCG-803 cell lines and no cytotoxicity against normoxic BRL-3A cells and exhibited effective inhibition on tumor growth of MCF-7-cell-inoculated xenograft nude mice. This strategy may provide a promising platform for selective two-photon imaging hypoxia status, real-time tracking drug release, and personalized solid tumor treatment.

Design, synthesis and biological evaluation of novel hydroxamic acid based histone deacetylase 6 selective inhibitors bearing phenylpyrazol scaffold as surface recognition motif.

In recent years, inhibition of HDAC6 became a promising therapeutic strategy for the treatment of cancer and HDAC6 inhibitors were considered to be potent anti-cancer agents. In this work, celecoxib showed moderate degree of HDAC6 inhibition activity and selectivity in preliminary enzyme inhibition activity assay. A series of hydroxamic acid derivatives bearing phenylpyrazol moiety were designed and synthesized as HDAC6 inhibitors. Most compounds showed potent HDAC6 inhibition activity. 11i was the most selective compound against HDAC6 with IC50 values of 0.020µM and selective factor of 101.1. Structure-activity relationship analysis indicated that locating the linker group at 1' of pyrazol gave the most selectivity. The most compounds 11i (GI50=3.63µM) exhibited 6-fold more potent than vorinostat in HepG2 cells. Considering of the high selectivity against HDAC6 and anti-proliferation activity, such compounds have potential to be developed as anti-cancer agents.

Design and synthesis of novel 6-hydroxy-4-methoxy-3-methylbenzofuran-7-carboxamide derivatives as potent Mnks inhibitors by fragment-based drug design.

A novel series of 6-hydroxy-4-methoxy-3-methylbenzofuran-7-carboxamide derivatives featured with various C-2 substituents were designed and synthesized as Mnks inhibitors through fragment-based drug design. Among them, 5b, 5i, 5o and 8k showed the best Mnk2 inhibitory activity with IC50 values of 1.45, 1.16, 3.55 and 0.27 µM, respectively. And these compounds inhibited the activity of Mnk1 at the same time. Furthermore, compounds 5o and 8k exhibited anti-proliferative effects to human leukemia cancer THP-1 and MOLM-13 cell lines and colon cancer HCT-116 cell line. Moreover, Western blot assay suggested that 8k could decrease the levels of p-eIF4E in a dose-dependent manner in HCT-116 cells. Docking studies demonstrated strong interactions between 8k and Mnk2. Therefore, this unique benzofuran scaffold demonstrated great potential to be further explored as potent Mnks inhibitors with improved potency.

WITHDRAWN:Hematological and vasodilator characteristics for high altitude acclimatization in Holstein heifers ascended to high altitude.

Objective: This study was conducted to investigate hematological and vasodilator characteristics for high altitude acclimatization in Holstein heifers ascended to high altitude. Methods: Holstein heifers resided at low altitude (LH; Beijing, China 43 meter), and Holstein heifers ascended to high altitude (Lhasa city, Tibet; 3,658 meter) after one year exposure including hypoxia acclimated Holstein heifers (AH; with mean pulmonary arterial pressure mPAP < 41 mmHg) and Holstein heifers affected by high altitude pulmonary hypertension (HAPH; with mPAP > 49 mmHg) and crossbred cattle (CB; Holstein × Tibet cattle) born and resided in Tibet were selected to compare parameters of blood gas, blood cells and vasodilators. Each group included 15 animals with 16 to 18 month of age. Results: The HAPH had greater mPAP than other cattle classes (P < 0.01). Alveolar ventilation (as indicated by partial pressure of carbon dioxide; PaCO2) was improved in AH and HAPH compared to LH, but it was lower in HAPH than in CB and AH (P < 0.05). In addition, LH had the greatest and HAPH had the lowest partial pressure of oxygen (PaO2) among the four cattle classes (P < 0.05). Erythropoietin and mean corpuscular hemoglobin concentration were greater in AH and HAPH than LH (P < 0.05). Serum iron was greater in AH than LA and HAPH (P < 0.05). Hypoxia exposure increased plasma nitric oxide and endothelin-1 in cattle resided in Tibet compared to LH. Additionally, AH had greater brain natriuretic peptides than HAPH and LH, and AH had greatest C-type natriuretic peptides than the other groups (P < 0.05). Conclusion: High altitude hypoxia acclimatization was achieved in Holstein heifers ascended to high altitude via augmented alveolar ventilation, serum iron, mean corpuscular hemoglobin concentration, natriuretic peptides and nitric oxide, it enables them to tolerate the high altitude.

Extraction, selenylation modification and antitumor activity of the glucan from Castanea mollissima Blume.

The present study aimed to characterize the glucan from C. mollissima Blume fruits and its selenium derivative, then investigate their antitumor activity in vitro. A glucan, designated as CPA, was firstly isolated from the fruits of C. mollissima Blume. Structure analysis indicated that CPA was a linear 1,6-α-D-glucan with the average molecular weight about 2.0 × 103 kDa. The selenylation modification derivative of CPA (sCPA), exhibited a stronger antiproliferative effect on tumor cells than CPA in vitro. CPA and sCPA could induce HeLa cells apoptosis and decrease mitochondrial membrane potential. sCPA could also arrest HeLa cells in S phase, promote reactive oxygen species generation and activate caspase-3 activity in HeLa cells. These results manifest that CPA and sCPA inhibit the proliferation of HeLa cells via different mechanisms, which is meaningful for their potential use as antitumor drugs.

Overexpression of Siah2 Is Associated With Poor Prognosis in Patients With Epithelial Ovarian Carcinoma.

OBJECTIVES: Seven in absentia homolog 2 (Siah2) is an E3 ubiquitin ligase that is expressed in mammals and is homologous to seven in absentia in Drosophila. Siah2 is involved in the progression of many malignancies. However, the role of Siah2 in ovarian cancer remains unclear. This study aims to evaluate the prognostic value of Siah2 expression for epithelial ovarian carcinoma (EOC) patients. MATERIALS AND METHODS: Immunohistochemical analysis was conducted using 32 normal ovarian specimens and 122 ovarian carcinoma specimens, respectively. We analyzed the correlations of Siah2 expression with the clinicopathological factors and prognosis of ovarian cancer patients. χ Analysis, Kaplan-Meier method, and multivariate Cox proportional hazard analysis were conducted for statistical analyses. RESULTS: Immunohistochemical staining demonstrated that the expression of Siah2 was higher in the EOC tissues than in the normal tissues. High Siah2 expression positively correlated with histological grade and lymph node metastasis but not with age, histologic type, International Federation of Gynecology and Obstetrics staging, and CA125. Patients with positive Siah2 expression showed lower overall survival and disease-free survival rates than those with negative Siah2 expression (P < 0.05 for both). Multivariate Cox analysis indicated that Siah2 was an independent parameter for overall survival (hazards ratio, 2.166; 95% confidence interval, 1.182-3.970; P = 0.012) and disease-free survival (hazards ratio, 1.819; 95% confidence interval, 1.030-3.216; P = 0.039). CONCLUSIONS: Siah2 is possibly involved in tumor development and progression in EOC. Thus, Siah2 is a promising biomarker for predicting the prognosis of ovarian cancer patients and may serve as a novel target for treating ovarian carcinoma.

Special AT-rich sequence-binding protein 1: a novel biomarker predicting cervical squamous cell carcinoma prognosis and lymph node metastasis.

OBJECTIVE: Special AT-rich sequence-binding protein 1 is aberrantly expressed in various malignant tumors. However, the expression and function of special AT-rich sequence-binding protein 1 in cervical squamous cell carcinoma have not been reported. The objective of this study was to investigate the clinical significance of special AT-rich sequence-binding protein 1 in cervical squamous cell carcinoma. METHODS: In this study, we investigated the expression of special AT-rich sequence-binding protein 1 through immunohistochemistry in 25 normal cervix specimens and 167 cervical squamous cell carcinomas and analyzed its association with various clinicopathologic parameters, including patient outcome. RESULTS: Special AT-rich sequence-binding protein 1 protein was detected in 58 (34.7%) out of 167 patients and was highly related to International Federation of Gynecology and Obstetrics stage, histologic grade, lymph node metastasis, vascular-lymphatic invasion and recurrence of cervical squamous cell carcinoma. Patients with positive special AT-rich sequence-binding protein 1 expression had significantly lower overall survival and disease-free survival compared with patients with negative expression of special AT-rich sequence-binding protein 1 (P = 0.001 and P < 0.001, respectively). A multivariate Cox regression analysis revealed that special AT-rich sequence-binding protein 1 was an independent prognostic marker for both disease-free survival and overall survival of cervical squamous cell carcinoma patients (P = 0.038 and P = 0.010, respectively). A multivariate logistic regression analysis showed that special AT-rich sequence-binding protein 1 expression was strongly associated with lymph node metastasis (odds ratio = 2.497; P = 0.032). Sensitivity and specificity of special AT-rich sequence-binding protein 1 for lymph node metastasis were 61.0 and 73.8%, respectively. CONCLUSIONS: These results showed that special AT-rich sequence-binding protein 1 expression was associated with tumor progression, metastasis and poor prognosis in cervical squamous cell carcinoma. It may serve as a new prognostic biomarker or a target for improving the treatment efficiency of patients with cervical squamous cell carcinoma.

Overexpression of special AT-rich sequence-binding protein 1 in endometrial cancer: a clinicopathologic study.

OBJECTIVE: Special AT-rich sequence-binding protein 1 (SATB1), as a genome organizer, serves important functions in tumor progression and metastasis. The SATB1 is overexpressed in various malignant tumors. However, the expression and prognostic value of SATB1 in endometrial cancer remain unknown. The aim of this study was to explore the prognostic values of SATB1 expression in endometrial cancer. METHODS/MATERIALS: We investigated the expression of SATB1 in 172 untreated endometrial cancer tissues and 25 normal endometrial tissues through immunohistochemical staining. We also analyzed the association of SATB1 level with clinicopathologic parameters and determined its prognostic significance. RESULT: Special AT-rich sequence-binding protein 1 was expressed in 78 (45.3%) of the 172 endometrial cancer samples, but not in the normal endometrial samples. The positive expression of SATB1 was associated with clinicopathologic factors, such as International Federation of Gynecology and Obstetrics stage, histological grade, myometrial invasion depth, lymph node metastasis, vascular/lymphatic invasion, and recurrence. The patients with positive SATB1 expression had worse overall survival and disease-free survival rates than the patients with negative SATB1 expression (P < 0.001 for both). Multivariate Cox analysis indicated that SATB1 was an independent parameter for overall survival (hazards ratio, 2.928; 95% confidence interval, 1.072-7.994; P = 0.036) and disease-free survival (hazards ratio, 2.825; 95% confidence interval, 1.111-7.181; P = 0.029). CONCLUSIONS: Results showed that SATB1 may be involved in tumor development and progression in endometrial cancer, may serve as a promising biomarker for predicting the prognosis of endometrial cancer patients, and thus may act as a novel target for treating endometrial carcinoma.

Effect of Intracoronary Plus Low-Dose Intravenous Tirofiban in Elderly Patients with Acute Myocardial Infarction.

BACKGROUND: To investigate the efficacy and safety of low-dose tirofiban in elderly patients undergoing primary percutaneous coronary intervention (PPCI) for acute myocardial infarction (AMI). METHODS: One hundred and four patients aged 70 years and above undergoing PPCI for AMI were divided into control (n=52) and study (n=52) groups. All patients received bolus intracoronary injection of tirofiban (10µg/kg), which was followed by intravenous infusion at 0.15µg/kg/min in the control group and at 0.075µg/kg/min in the study group for 24h. RESULTS: There was no statistically significant difference between the study group and the control group in patients with complete ST segment resolution (84.2% vs. 85.7%, P=0.851), peak high-sensitive cardiac troponin T level (5.1±1.9 vs. 5.8±2.6µg/L, P=0.123), scores of thrombus in the infarct-related artery (0.98±0.51 vs. 1.12±0.59, P=0.214), and patients with TIMI grade 3 flow (86.0% vs. 88.2%, P=0.737) after PPCI. There were no statistically significant differences between the two groups in left ventricular ejection fraction (57.1±6.3 vs. 57.7±6.1, P=0.611) and composite major adverse cardiovascular events rate (P =0.778) at 90 days after PCI. The total bleeding rate in the study group was lower than in the control group (P=0.048). CONCLUSION: In elderly patients with AMI undergoing primary PCI, low and standard dose of tirofiban exerts similar effects on platelet aggregation, coronary flow, infarct size, left ventricular systolic function and short-term clinical outcomes. Low dose regimen is associated with a lower bleeding rate than the standard dose.

Terbium promotes adhesion and osteogenic differentiation of mesenchymal stem cells via activation of the Smad-dependent TGF-ß/BMP signaling pathway.

With its special physical and chemical properties, terbium has been widely used, which has inevitably increased the chance of human exposure to terbium-based compounds. It was reported that terbium mainly deposited in bone after introduction into the human body. Although some studies revealed the effects of terbium on bone cell lines, there have been few reports about the potential effect of terbium on adhesion and differentiation of mesenchymal stem cells (MSCs). In this study, we investigated the effects of terbium on the adhesion and osteogenic and adipogenic differentiation of MSCs and the associated molecular mechanisms. Our data reveal that terbium promoted the osteogenic differentiation in a time-dependent manner and conversely inhibited the adipogenic differentiation of MSCs. Meanwhile, the cell-cell or cell-matrix interaction was enhanced by activating adherent-related key factors, which were evaluated by real-time reverse transcriptase polymerase chain reaction (RT-PCR). Real-time RT-PCR and Western blot analysis were also performed to further detect osteogenic and adipogenic biomarkers of MSCs. The regulation of terbium on differentiation of MSCs led to the interaction between the transforming growth factor ß/bone morphogenetic protein and peroxisome-proliferator-activated receptor γ (PPARγ) signaling pathways, resulting in upregulation of the osteogenic master transcription factors, such as Runt-related transcription factor 2, bone morphogenetic protein 2, collagen I, alkaline phosphatase, and osteocalcin, and downregulation of the adipogenic master transcription factors, such as PPARγ2. The results provide novel evidence to elucidate the mechanisms of bone metabolism by terbium and may be helpful for more rational application of terbium-based compounds in the future.