The trend of dental check-up and prevalence of dental complications following the use of bone modifying agents in patients with metastatic breast and prostate cancer: analysis of data from the Korean National Health Insurance Service.

BACKGROUND: Bone-modifying agents (BMA) are key components in the management of cancer patients with bone metastasis. Despite their clinical benefits, the use of BMA is associated with dental adverse events (AEs) including medication-related osteonecrosis of the jaw (MRONJ). This study investigated the frequency of dental surveillance before BMA treatment and the prevalence of dental AEs including MRONJ, after BMA treatment in patients with bone metastasis from breast and prostate cancer using data from the national health insurance system. METHODS: Data, including age, cancer diagnosis, administered BMA, and dental AEs during cancer treatment, of patients with bone metastasis from breast and prostate cancer who received at least one infusion of BMA between 2007 and 2019 were extracted from the Korean National Health Insurance Service (KNHIS) dataset. RESULTS: Of the 15,357 patients who received BMA, 1,706 patients (11.1%) underwent dental check-ups before BMA treatment. The proportion of patients receiving dental check-up increased from 4.4% in 2007 to 16.7% in 2019. Referral to dentists for a dental check-up was more active in clinics/primary hospitals than general/tertiary hospitals, and medical doctors and urologists actively consulted to dentists than general surgeons, regardless of the patient's health insurance status. After BMA treatment, 508 patients (3.8%) developed dental AEs, including abscess (42.9%), acute periodontitis (29.7%), acute pericoronitis (14.9%), and MRONJ (12.5% of dental AEs cases, 0.5% of total BMA treated patients). CONCLUSIONS: Considering the long treatment period in patients with metastatic cancer, coordination between dentists and oncologists is necessary to ensure appropriate dental management before the initiation of BMA.

Cancer treatment-induced bone loss.

Cancer treatment-induced bone loss (CTBL) is associated with anti-tumor treatments, including endocrine therapies, chemotherapeutic treatments, radiotherapy, glucocorticoids, and tyrosine kinase inhibitors. Osteoporosis, characterized by the loss of bone mass, can increase the risk of fractures, leading to mortality and long-term disability, even after cancer remission. Cancer and osteoporosis have marked clinical and pathogenetic similarities. Both have a multifactorial etiology, affect the geriatric population, and markedly influence quality of life. Lifestyle management, including calcium and vitamin D supplementation, is recommended but the supporting evidence is limited. Oral and injectable bisphosphonates are effective for osteoporosis and malignant bone disease. Bisphosphonates increase bone mineral density (BMD) in patients with CTBL. Denosumab is also used in the management of CTBL; in clinical trials, it improved BMD and reduced the risk of fracture. Currently, there are no bone anabolic therapies for patients with cancer. Appropriate therapies are necessary to maintain optimal bone health, particularly in patients at heightened risk.

A young woman with atypical McCune-Albright syndrome and the difficult road to recovery: a case report.

Background: Fiber dysplasia is a complex condition that presents with various clinical manifestations, such as deformity, dysfunction, pathological fractures, and endocrine disorders. McCune-Albright syndrome (MAS) is a rare subtype of fiber dysplasia. This article reports a case of atypical McCune-Albright syndrome in a patient with a femoral neck fracture. Case presentation: A patient with atypical McCune-Albright syndrome sustained a right femoral neck fracture and underwent multiple treatments, including total hip replacement, intravenous infusion of zoledronic acid, oral calcium supplementation, right supracondylar osteotomy, orthopedic surgery, plate and screw internal fixation for a left femoral shaft fracture, and removal of the right femoral plate. The patient also developed a submaxillary infection complicated by mandibular osteonecrosis. Conclusion: Patients with MAS may experience rare complications as a result of their unique condition, regardless of whether they receive drug or surgical treatment. Therefore, personalized drug regimens and feasible surgical options are necessary.

The additive effect of vitamin K supplementation and bisphosphonate on fracture risk in post-menopausal osteoporosis: a randomised placebo controlled trial.

This study assessed whether vitamin K, given with oral bisphosphonate, calcium and/or vitamin D has an additive effect on fracture risk in post-menopausal women with osteoporosis. No difference in bone density or bone turnover was observed although vitamin K1 supplementation led to a modest effect on parameters of hip geometry. PURPOSE: Some clinical studies have suggested that vitamin K prevents bone loss and may improve fracture risk. The aim was to assess whether vitamin K supplementation has an additive effect on bone mineral density (BMD), hip geometry and bone turnover markers (BTMs) in post-menopausal women with osteoporosis (PMO) and sub-optimum vitamin K status receiving bisphosphonate, calcium and/or vitamin D treatment. METHODS: We conducted a trial in 105 women aged 68.7[12.3] years with PMO and serum vitamin K1 ≤ 0.4 µg/L. They were randomised to 3 treatment arms; vitamin K1 (1 mg/day) arm, vitamin K2 arm (MK-4; 45 mg/day) or placebo for 18 months. They were on oral bisphosphonate and calcium and/or vitamin D. We measured BMD by DXA, hip geometry parameters using hip structural analysis (HSA) software and BTMs. Vitamin K1 or MK-4 supplementation was each compared to placebo. Intention to treat (ITT) and per protocol (PP) analyses were performed. RESULTS: Changes in BMD at the total hip, femoral neck and lumbar spine and BTMs; CTX and P1NP did not differ significantly following either K1 or MK-4 supplementation compared to placebo. Following PP analysis and correction for covariates, there were significant differences in some of the HSA parameters at the intertrochanter (IT) and femoral shaft (FS): IT endocortical diameter (ED) (% change placebo:1.5 [4.1], K1 arm: -1.02 [5.07], p = 0.04), FS subperiosteal/outer diameter (OD) (placebo: 1.78 [5.3], K1 arm: 0.46 [2.23] p = 0.04), FS cross sectional area (CSA) (placebo:1.47 [4.09],K1 arm: -1.02[5.07], p = 0.03). CONCLUSION: The addition of vitamin K1 to oral bisphosphonate with calcium and/or vitamin D treatment in PMO has a modest effect on parameters of hip geometry. Further confirmatory studies are needed. TRIAL REGISTRATION: The study was registered at Clinicaltrial.gov:NCT01232647.

Bisphosphonate treatment in inaccessible osteoid osteomas: An alternative therapeutic approach.

INTRODUCTION: Osteoid osteoma is a benign osteogenic tumour traditionally treated by surgical excision or percutaneous CT-guided procedures. We describe three cases of osteoid osteomas of which the locations were difficult to access, or for which the procedure was potentially unsafe, involving treatment with zoledronic acid infusions. CASE DESCRIPTION: We report here three male 28-to-31-year-old patients with no medical history who had osteoid osteomas located at the second cervical vertebra, the femoral head, and the third lumbar vertebra respectively. These lesions were responsible for inflammatory pain requiring daily treatment with acetylsalicylic acid. Given the impairment risk, all of the lesions were ineligible for surgical or percutaneous treatment. Patients were successfully treated by 3 to 6 monthly zoledronic acid infusions. All patients experienced complete relief of their symptoms allowing aspirin discontinuation, without any side effects. In the first two cases, CT and MRI control showed nidus mineralization and bone marrow oedema regression, correlating with the pain decrease. After 5years of follow-up, there had been no recurrence of the symptoms. CONCLUSION: In these patients, monthly 4mg zoledronic acid infusions have been safe and effective in the treatment of inaccessible osteoid osteomas.

Serious spondylodiscitis, septic sacroiliitis and multiple abscesses after ozone therapy for low back pain: A case report on good response to combined treatment with empiric antibiotic and neridronate.

Ozone therapy is a minimally invasive technique now widely used for the treatment of pain due to herniated discs. In literature there are conflicting results concerning its real effectiveness and few data about its possible complications. In this case report we present a case of spondylodiscitis, septic arthritis and gluteal abscess following the execution of 4 sessions of ozone therapy. Given the impossibility of isolating the etiological agent, an empirical antibiotic therapy with an overall duration of 6 weeks was set up, initially with daptomycin and ceftriazone, to which was added after 2 days metronidazole, administered intravenously; after 20 days the cephalosporin was replaced with oral amoxicillin/clavulanate. Neridronate was added to treat bone edema and to avoid bone erosion. The patient showed improvement of both clinical conditions and inflammation indexes, and was discharged after 4 weeks without further complications at follow-up. Few cases are reported in the literature about spondylodiscitis secondary to ozone treatment, and just 1 case is described about the use of neridronate as additive drug to antibiotic treatment in spondylodiscitis to avoid bone disruption and surgery complications.

Fanconi Syndrome Associated with Long-term Treatment with Zoledronate.

Intravenous bisphosphonate therapy is used to prevent fractures in the management of bone metastasis. However, it may induce renal damage. We herein report an 81-year-old woman with Fanconi syndrome and osteomalacia who had been diagnosed with metastatic breast cancer and received treatment with zolendronate for over 5 years. Her bone markers normalized after switching zolendronate to denosmab and starting vitamin D and mineral supplementation. This case shows that chronic renal damage induced by zolendronate can cause osteomalacia. In patients with intravenous zolendronate therapy, close monitoring of renal and bone markers is needed, even under long-term therapy.

Managing Bone Health in Breast Cancer.

OBJECTIVE: Osteoporosis is a common condition that can be caused or exacerbated by estrogen deficiency. METHODS: This narrative review will discuss optimizing bone health in the setting of adjuvant endocrine treatments for hormone receptor-positive breast cancer and the current use of antiresorptive agents as adjuvant therapy and as bone modifying agents. RESULTS: Adjuvant endocrine treatments for hormone receptor-positive breast cancer (tamoxifen and aromatase inhibitors) affect bone health. The exact effect depends on the agent used and the menopausal state of the woman. Antiresorptive medications for osteoporosis, bisphosphonates and denosumab, lower the risk of bone loss from aromatase inhibitors. Use of bisphosphonates as adjuvant treatment in breast cancer, regardless of hormone receptor status, is increasing because of benefits seen to cancer relapse and survival. CONCLUSION: Optimizing bone health in women with breast cancer during and after cancer treatment is informed by an understanding of breast cancer treatment and its skeletal effect.

Green synthesis and characterization of bisphosphonate conjugated gold nanoparticle with Asparagus racemosus root extract.

Bisphosphonates improve orthodontic anchorage. More targeted action of this drug can be achieved through its conjugation with gold nanoparticles. Asparagus racemosus is a green edible medicinal plant used in Ayurvedic preparations to treat aging, vigor, immunity, longevity, and skeletal issues. Therefore, it is of interest to report the green synthesized Bisphosphonate conjugated gold nanoparticles with Asparagus racemosus extract and to characterize them.

[Therapeutic alternatives for drug-associated maxillary osteonecrosis (MRONJ): reports of two clinical cases and review of the literature]. / Alternativas terapéuticas de osteonecrosis maxilar asociada a medicamentos (ONMAM): reportes de dos casos clínicos y revisión de la literatura.

Introduction: Drug-associated Maxillary Osteonecrosis is one of the most relevant adverse effects in treatment with antiresorptive drugs such as bisphosphonates and denosumab. Oncological conditions such as multiple myeloma, breast cancer, prostate, and bone-metabolic disorders such as osteoporosis lead the indications for these antiresorptive therapies. Treatment is complex because the disease is often refractory. Pharmacological, conservative and surgical treatments are described. Objective: The aim of this study is to report two clinical cases of MRONJ treated with two different therapeutic protocols and the analysis of the available literature on these aspects based on the clinical classification defined by the American Association of Oral and Maxillofacial Surgeons (AAOMS). Conclusion: Patients who develop clinical signs of great morbidity associated with MRONJ, may see their quality of life conditioned and suffer a worsening of their underlying pathology. MRONJ treatment is conditioned by the stage of the disease, its success depends on interdisciplinary management and strict medical and dental clinical follow-up, as well as rigorous monitoring to prevent or detect future recurrences early.

Introducción: La Osteonecrosis Maxilar asociada a Medicamentos (ONMAM) constituye uno de los efectos adversos más relevantes en el tratamiento con drogas antirresortivas como bifosfonatos y denosumab. Patologías oncológicas como mieloma múltiple, cáncer de mama, próstata, y alteraciones óseas-metabólicas como la osteoporosis lideran las indicaciones para estas terapias antirresortivas. El tratamiento es complejo debido a que muchas veces, la enfermedad es refractaria a la terapéutica aplicada. Se describen tratamientos farmacológicos, conservadores y quirúrgicos. Objetivo: El objetivo de este trabajo es reportar dos casos clínicos de ONMAM tratados con dos protocolos terapéuticos diferentes y el análisis de la literatura disponible en la actualidad sobre estos aspectos en base a la clasificación clínica definida por la American Association of Oral and Maxillofacial Surgeons (AAOMS). Conclusión: Los pacientes que desarrollan cuadros clínicos bucales de gran morbilidad como lo es ONMAM, pueden ver condicionada su calidad de vida y sufrir un agravamiento de su patología de base. El tratamiento de ONMAM está condicionado al estadio de la enfermedad, el éxito del mismo depende del manejo interdisciplinario y de un estricto seguimiento clínico médico y odontológico, así como también un riguroso monitoreo para evitar o detectar precozmente futuras recurrencias.

The Heptaprenyl Diphosphate Synthase (Coq1) Is the Target of a Lipophilic Bisphosphonate That Protects Mice against Toxoplasma gondii Infection.

Prenyldiphosphate synthases catalyze the reaction of allylic diphosphates with one or more isopentenyl diphosphate molecules to form compounds such as farnesyl diphosphate, used in, e.g., sterol biosynthesis and protein prenylation, as well as longer "polyprenyl" diphosphates, used in ubiquinone and menaquinone biosynthesis. Quinones play an essential role in electron transport and are associated with the inner mitochondrial membrane due to the presence of the polyprenyl group. In this work, we investigated the synthesis of the polyprenyl diphosphate that alkylates the ubiquinone ring precursor in Toxoplasma gondii, an opportunistic pathogen that causes serious disease in immunocompromised patients and the unborn fetus. The enzyme that catalyzes this early step of the ubiquinone synthesis is Coq1 (TgCoq1), and we show that it produces the C35 species heptaprenyl diphosphate. TgCoq1 localizes to the mitochondrion and is essential for in vitro T. gondii growth. We demonstrate that the growth defect of a T. gondii TgCoq1 mutant is rescued by complementation with a homologous TgCoq1 gene or with a (C45) solanesyl diphosphate synthase from Trypanosoma cruzi (TcSPPS). We find that a lipophilic bisphosphonate (BPH-1218) inhibits T. gondii growth at low-nanomolar concentrations, while overexpression of the TgCoq1 enzyme dramatically reduced growth inhibition by the bisphosphonate. Both the severe growth defect of the mutant and the inhibition by BPH-1218 were rescued by supplementation with a long-chain (C30) ubiquinone (UQ6). Importantly, BPH-1218 also protected mice against a lethal T. gondii infection. TgCoq1 thus represents a potential drug target that could be exploited for improved chemotherapy of toxoplasmosis. IMPORTANCE Millions of people are infected with Toxoplasma gondii, and the available treatment for toxoplasmosis is not ideal. Most of the drugs currently used are only effective for the acute infection, and treatment can trigger serious side effects requiring changes in the therapeutic approach. There is, therefore, a compelling need for safe and effective treatments for toxoplasmosis. In this work, we characterize an enzyme of the mitochondrion of T. gondii that can be inhibited by an isoprenoid pathway inhibitor. We present evidence that demonstrates that inhibition of the enzyme is linked to parasite death. In addition, the inhibitor can protect mice against a lethal dose of T. gondii. Our results thus reveal a promising chemotherapeutic target for the development of new medicines for toxoplasmosis.

Efficacy and Safety of Monthly Minodronate Therapy in Postmenopausal Breast Cancer Patients Receiving Aromatase Inhibitors.

BACKGROUND/AIM: Post-menopausal breast cancer (BC) patients who receive adjuvant aromatase inhibitor (AI) therapy may be at increased risk of bone loss, osteoporosis, and bone fracture. We aimed to evaluate the efficacy and safety of oral bisphosphonate minodronate in preventing bone loss complications. PATIENTS AND METHODS: Patients receiving AI and 80% of those with suboptimal bone mineral density (BMD) were prescribed monthly oral minodronate 50 mg every 4 weeks for 72 weeks. BMD, bone metabolism markers, incidence of bone fractures, medication compliance, and other adverse events (AE) were examined every 24 weeks following administration. RESULTS: Fifty postmenopausal BC patients with a median age of 64.0 years were enrolled. The mean value of lumbar spine BMD was higher than that of the value before the minodronate administration at each observation point. Before and after the treatment, the median serum values of Tartrate-resistant Acid Phosphatase 5b (TRACP-5b) (mU/dl) and serum type I collagen cross-linked N-telopeptide (NTX) (nmolBCE/l) were decreased from 535.7 and 18.5 to 230.1 and 11.9, respectively. No adverse grade 2 or higher event was observed throughout this study. CONCLUSION: The combined administration of minodronate and AIs was safe and effective in preventing bone loss complications in postmenopausal BC patients.

Inhibition of osteoclastogenesis after bisphosphonate therapy discontinuation: an in vitro approach.

Osteoclasts are specialized cells that degrade and resorb bone. Bisphosphonates (BPs) are drugs with well-known capacity to inhibit the resorption of mineralized tissues. Nitrogen-containing BPs, like alendronate (ALN) and zoledronic acid (ZA), inactivate osteoclast activity mostly by alterations on the cytoskeleton architecture of the cell. In this study, we used an in vitro model to test the hypothesis that bisphosphonates may have inhibitory effects on the osteoclastogenesis and osteoclast activity after the therapy was discontinued. Primary osteoclasts were generated from mouse bone marrow in media supplemented with 1,25-dihydroxyvitamin D3 and cultivated over bones pre-treated with ALN and ZA. The pre-saturation of the bone slices with bisphosphonates did not affect cell viability. We found, however, that by disrupting the gene expression of RANKL and OPG the osteoclastogenesis and resorption activity of osteoclasts was significantly disturbed. These inhibitory effects were confirmed by scanning electron microscopy resorption assay, assessment of osteoclast ultrastructure, and by gene expression analysis of TRAP and Cathepsin K. In conclusion, ALN and ZA adhered to the bone matrix reduced the osteoclast activity in vitro.

Frequent fractures and sclerotic thick bands on physes related to oral alendronate treatments.

Bisphosphonate treatment has known effects of improving bone mineral density and preventing fractures in children with steroid-induced osteoporosis. However, there have been reports that high-dosage pamidronate therapy induces osteopetrosis in the borders of bones. A 10-year-old boy undergoing long-term treatment with oral alendronate developed frequent fractures throughout adolescence while playing basketball. Radiographs showed osteosclerotic bands on the metaphyses of his long bones and vertebrae, and fractures were evident in the regions surrounding the osteosclerotic lesions: a stress fracture in the fourth metatarsal, anterior limbus vertebra (T12), spondylolysis (L3 and L5), and osteochondritis dissecans of the left lateral femoral condyle. Alendronate had been taken for a period of 6 years when the treatment was discontinued. Approximately 18 months after discontinuation, sclerotic bands remained evident; however, 4 years after discontinuation, sclerotic banding still surrounded the wing of the ilium but appeared diminished in the knees. In children and adolescents who engage in sports activities and are being treated with steroids and bisphosphonates, the possibility of pathological stress fractures should be considered.

Photodynamic therapy and photobiomodulation therapy in zoledronic acid-induced osteonecrosis in rats.

BACKGROUND: This study investigated the effect of antimicrobial photodynamic therapy (PDT), using methylene blue (MBO) and photobiomodulation therapy (PT), on the alveolar bone of rats submitted to bisphosphonate-induced osteonecrosis of the maxillaries (OMB) model using zoledronic acid (ZA). METHODS: Sixty rats divided into six groups were used: SALINE, PDT, ZA, ZA+PDT, ZA+PT, and ZA+MBO. Three weekly administrations (Days 0, 7, and 14) of ZA 0.20 mg/kg or saline solution were performed. After one month (Day 42), the exodontia of the left lower first molars were performed. An additional dose of ZA was administered at Day 49. PDT was performed on days 42, 45, 49, and 54. One month after exodontia (Day 70), the animals were euthanized to obtain samples for imaging and microscopic analysis. ANOVA/Bonferroni tests were used for statistical analysis. RESULTS: The ZA+PDT group showed a significantly lower percentage of apoptotic osteocytes than the ZA group (p < 0.001). The ZA+MBO, ZA+PT, and PDT groups significantly reduced the number of mononuclear cells compared to the ZA group (p < 0.001). The ZA+PT and ZA+PDT groups showed a significant reduction in the number of CD 68+ (p < 0.001) and CD3+ (p = 0.002) cells compared to the ZA group. The number of cells expressing INF-y had a significant reduction in the groups co-treated with PT and PDT compared to the ZA group (p < 0.001). CONCLUSIONS: We conclude that PDT and PT attenuated the severity of OMB and the inflammatory process due to a reduction of macrophages, T lymphocytes, and cytokines that stimulate the activity of these cells.

Advanced application of stimuli-responsive drug delivery system for inflammatory arthritis treatment.

Inflammatory arthritis is a major cause of disability in the elderly. This condition causes joint pain, loss of function, and deterioration of quality of life, mainly due to osteoarthritis (OA) and rheumatoid arthritis (RA). Currently, available treatment options for inflammatory arthritis include anti-inflammatory medications administered via oral, topical, or intra-articular routes, surgery, and physical rehabilitation. Novel alternative approaches to managing inflammatory arthritis, so far, remain the grand challenge owing to catastrophic financial burden and insignificant therapeutic benefit. In the view of non-targeted systemic cytotoxicity and limited bioavailability of drug therapies, a major concern is to establish stimuli-responsive drug delivery systems using nanomaterials with on-off switching potential for biomedical applications. This review summarizes the advanced applications of triggerable nanomaterials dependent on various internal stimuli (including reduction-oxidation (redox), pH, and enzymes) and external stimuli (including temperature, ultrasound (US), magnetic, photo, voltage, and mechanical friction). The review also explores the progress and challenges with the use of stimuli-responsive nanomaterials to manage inflammatory arthritis based on pathological changes, including cartilage degeneration, synovitis, and subchondral bone destruction. Exposure to appropriate stimuli induced by such histopathological alterations can trigger the release of therapeutic medications, imperative in the joint-targeted treatment of inflammatory arthritis.

[Three-year-old boy with significant hypercalcemia in the context of vitamin D intoxication]. / Drei Jahre alter Junge mit ausgeprägter Hyperkalzämie im Rahmen einer chronischen Vitamin-D-Intoxikation.

This article reports the case of a 3-year-old boy who was presented with a significant hypercalcemia caused by vitamin D toxicity. The parents had bought over the counter high-dose vitamin D drops online and administered the drops without following the dosage recommendation. The refractory hypercalcemia was treated with one dose of a bisphosphonate, which quickly caused a stabilization of serum calcium levels. The boy could be discharged free of complaints.

Mineral and Bone Consequences of High Dose Denosumab Therapy to Treat an Aneurysmal Bone Cyst, a Child Case Report.

Aneurysmal bone cysts (ABCs) are rare benign pseudotumoral bone lesions with potential aggressive behavior due to the extensive destruction of surrounding bone. Traditionally, these tumors were treated with open surgery, but there is more and more a shift to less invasive procedures. In particular, treatment for spinal ABCs is generally unsatisfactory due to the risk of morbidity, neurological impairment and recurrence, and there is a need for innovative therapies. Denosumab has been reported as a useful treatment in giant cell tumors of bone (GCTB), so its efficacy has been tested also in other fibro-osseus lesions affecting children and adolescents, such as spinal aneurysmal bone cysts. The pediatric literature is limited to case reports and small series, all of which highlight the efficacy of this treatment on lesions growth and associated bone pain. Some of these reports have already reported well known side effects associated with denosumab, such as hypocalcemia at the beginning of the treatment, and rebound hypercalcemia at the discontinuation. The latter seems to be more frequent in children and adolescents than in adults, probably due to the higher baseline bone turnover in children. In addition, the use of denosumab in young patients could affect both bone modeling and remodeling, even if the consequences on the growing skeleton have not been reported in detail. Here we describe the case of a spinal ABC diagnosed in an 8-year old young boy which was not accessible to surgery but responded favorably to denosumab. Our aim is to describe the rapid changes in mineral and bone homeostasis in this patient, that required advice from the experts of the European Reference Network (ERN) for rare bone and endocrine diseases.

Timing of geranylgeraniol addition increases osteoblast activities under alendronate condition.

BACKGROUND: Alendronate (ALN), a nitrogen-containing bisphosphonate, is prescribed to treat bone diseases. ALN acts as an inhibitor of enzymes in the mevalonate pathway, which results in reducing osteoblast viability and mineralization. Geranylgeraniol (GGOH) is a substrate in mevalonate pathway and mediates protein prenylation in the cells. OBJECTIVE: To investigate the effects of GGOH on ALN-treated osteoblast activities in order to improve the application of GGOH. METHODS: MC3T3 cells were treated with ALN. GGOH were added at different time points. Cell activities were examined using alizarin red S, MTT assay, alkaline phosphatase (ALP) activity, and quantitative polymerase chain reaction. RESULTS: ALN decreased mineralization. In the presence of ALN, GGOH addition at the first week of culture increased mineralization compared with the addition at other time points. ALN treatment for 7 days caused a reduction in osteoblast and pre-osteoblast viability compared with untreated cells. GGOH supplement partially rescued cell viability and increased total protein in cells treated with ALN. Furthermore, GGOH significantly upregulated gene expressions of Col I, OPN, VEGF, and VEGFR2. CONCLUSION: GGOH could be best applied at the early stage of osteogenesis since GGOH helped increasing cell viability and differentiation at the first 7 day of treatment.

4-Substituted-1,2,3-triazolo nucleotide analogues as CD73 inhibitors, their synthesis, in vitro screening, kinetic and in silico studies.

Three series of nucleotide analogues were synthesized and evaluated as potential CD73 inhibitors. Nucleobase replacement consisted in connecting the appropriate aromatic or purine residues through a triazole moiety that is generated from 1,3-dipolar cycloaddition. The first series is related to 4-substituted-1,2,3-triazolo-ß-hydroxyphosphonate ribonucleosides. Additional analogues were also obtained, in which the phosphonate group was replaced by a bisphosphonate pattern (P-C-P-C, series 2) or the ribose moiety was removed leading to acyclic derivatives (series 3). The ß-hydroxyphosphonylphosphonate ribonucleosides (series 2) were found to be potent inhibitors of CD73 using both purified recombinant protein and cell-based assays. Two compounds (2a and 2b) that contained a bis(trifluoromethyl)phenyl or a naphthyl substituents proved to be the most potent inhibitors, with IC50 values of 4.8 ± 0.8 µM and 0.86 ± 0.2 µM, compared to the standard AOPCP (IC50 value of 3.8 ± 0.9 µM), and were able to reverse the adenosine-mediated immune suppression on human T cells. This series of compounds illustrates a new type of CD73 inhibitors.