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Toxicology Feb 2024P-glycoprotein (Pgp) is a member of the ATP-binding cassette family of transporters that confers multidrug resistance to cancer cells and is actively involved in the...
P-glycoprotein (Pgp) is a member of the ATP-binding cassette family of transporters that confers multidrug resistance to cancer cells and is actively involved in the pharmacokinetics and toxicokinetics of a big variety of drugs. Extensive studies have provided insights into the binding of many compounds, but the precise mechanism of translocation across the membrane remains unknown; in this context, the major challenge has been to understand the basis for its polyspecificity. In this study, molecular dynamics (MD) simulations of human P-gp (hP-gp) in an explicit membrane-and-water environment were performed to investigate the dynamic behavior of the transporter in the presence of different compounds (active and inactive) in the binding pocket and ATP molecules within the nucleotide binding domains (NBDs). The complexes studied involve four compounds: cyclosporin A (CSA), amiodarone (AMI), pamidronate (APD), and valproic acid (VPA). While CSA and AMI are known to interact with P-gp, APD and VPA do not. The results highlighted how the presence of ATP notably contributed to increased flexibility of key residues in NBD1 of active systems, indicating potential conformational changes activating the translocation mechanism. MD simulations reveal how these domains adapt and respond to the presence of different substrates, as well as the influence of ATP binding on their flexibility. Furthermore, distinctive behavior was observed in the presence of active and inactive compounds, particularly in the arrangement of ATP between NBDs, supporting the proposed nucleotide sandwich dimer mechanism for ATP binding. This study provides comprehensive insights into P-gp behavior with various ligands and ATP, offering implications for drug development, toxicity assessment and demonstrating the validity of the results derived from the MD simulations.
Topics: Humans; Adenosine Triphosphate; ATP Binding Cassette Transporter, Subfamily B; Membrane Glycoproteins; Membrane Transport Proteins; Molecular Dynamics Simulation; Nucleotides; Protein Binding
PubMed: 38272384
DOI: 10.1016/j.tox.2024.153732 -
American Journal of Clinical Oncology Apr 2024This study evaluated real-world treatment patterns of approved bone-targeting agents (BTAs) with various mechanisms of action-pamidronate, zoledronic acid, and...
Treatment Patterns of Bone-targeting Agents Among Solid Tumor Patients With Bone Metastases: An Analysis of Electronic Health Record Data in the United States From 2014 to 2018.
OBJECTIVES
This study evaluated real-world treatment patterns of approved bone-targeting agents (BTAs) with various mechanisms of action-pamidronate, zoledronic acid, and denosumab-for the prevention of skeletal-related events in patients with bone metastases (BM) from solid tumors.
METHODS
Adult patients with BM secondary to solid tumors between January 1, 2014, and December 31, 2018, were identified from the Flatiron Health Oncology Services Comprehensive Electronic Records database and categorized by BTA use and therapy type. Time from diagnosis to initiation, persistence (mean time on treatment), and compliance (≥12 administrations/year) with BTA with up to 4 years of follow-up were examined.
RESULTS
This study included 27,268 patients with BM (breast cancer, 32.7%; lung cancer, 16.5%; prostate cancer, 17.2%; and other solid tumors, 33.6%); of these, 41.4% initiated denosumab after BM diagnosis; 21.3%, zoledronic acid; 0.6%, pamidronate; and 36.7% had no treatment record. Mean (SD) time to initiation for denosumab or zoledronic acid was 68.6 (157.0) days (denosumab, 70.3 (160.4) days; zoledronic acid, 65.2 [150.2] days). Mean persistence and compliance (first year of treatment) were significantly higher for denosumab than for zoledronic acid (22.0 vs. 14.9 mo [ P <0.0001] and 42.3% vs. 34.8% [ P <0.0001], respectively). Treatment compliance was the highest in patients with breast cancer (denosumab, 48.2%; zoledronic acid, 39.1%).
CONCLUSION
Real-world BTA treatment patterns in the United States suggest that over one-third of patients with BM secondary to solid tumors remain untreated and less than 50% of the patients received ≥12 administrations/year of BTA therapy.
Topics: Male; Humans; United States; Zoledronic Acid; Denosumab; Bone Density Conservation Agents; Pamidronate; Electronic Health Records; Bone Neoplasms; Breast Neoplasms; Diphosphonates
PubMed: 38200688
DOI: 10.1097/COC.0000000000001075 -
European Radiology Jan 2024To present MRI distribution of active osteitis in a single tertiary referral center cohort of patients with chronic nonbacterial osteomyelitis (CNO).
Preferential involvement of the pelvis and hips along with active sacroiliitis in chronic nonbacterial osteomyelitis: MRI of 97 patients from a single tertiary referral center.
OBJECTIVE
To present MRI distribution of active osteitis in a single tertiary referral center cohort of patients with chronic nonbacterial osteomyelitis (CNO).
METHODS
Two musculoskeletal radiologists retrospectively reviewed MRI examinations of all patients with a final clinical diagnosis of CNO over 15 years. Sites of active osteitis at any time during the course of disease were divided into seven groups: (A) mandible, sternum, clavicles, or scapulas; (B) upper extremities; (C) subchondral sacrum and ilium immediately subjacent to sacroiliac joints (active osteitis denoting "active sacroiliitis" here); (D) pelvis and proximal 1/3 of femurs (excluding group C); (E) bones surrounding knees including distal 2/3 of femurs and 1/2 of proximal tibias and fibulas; (F) distal legs (including distal 1/2 of tibias and fibulas), ankles, or feet; (G) spine (excluding group C). Temporal changes of lesions in response to treatment (or other treatment-related changes such as pamidronate lines) were not within the scope of the study.
RESULTS
Among 97 CNO patients (53 males [55%], 44 females; age at onset, mean ± SD, 8.5 ± 3.2 years; age at diagnosis, 10.3 ± 3.3 years), whole-body (WB) MRI was performed in 92%, mostly following an initial targeted MRI (94%). A total of 557 (346 targeted and 211 WB) MRIs were analyzed. Biopsy was obtained in 39 patients (40%), all consistent with CNO or featuring supporting findings. The most common locations for active osteitis were groups D (78%; 95% CI 69‒85%) and C (72%; 95% CI 62‒80%).
CONCLUSION
Pelvis and hips were preferentially involved in this cohort of CNO patients along with a marked presence of active sacroiliitis.
CLINICAL RELEVANCE STATEMENT
When suggestive findings of CNO are identified elsewhere in the body, the next targeted site of MRI should be the pelvis (entirely including sacroiliac joints) and hips, if whole-body MRI is not available or feasible.
KEY POINTS
• Heavy reliance on MRI for diagnosis of CNO underscores the importance of suggestive distribution patterns. • Pelvis and hips are the most common (78%) sites of CNO involvement along with active sacroiliitis (72%). • Pelvis including sacroiliac joints and hips should be targeted on MRI when CNO is suspected.
PubMed: 38180529
DOI: 10.1007/s00330-023-10558-7 -
Proceedings (Baylor University. Medical... 2024Breast cancer is the most common cancer in women and most often metastasizes to the bone, resulting in skeletal-related events (SREs). Bone-modifying agents (BMAs)...
BACKGROUND
Breast cancer is the most common cancer in women and most often metastasizes to the bone, resulting in skeletal-related events (SREs). Bone-modifying agents (BMAs) including denosumab, a monoclonal antibody against the receptor activator of nuclear factor kappa-b ligand (RANKL), and pamidronate, a bisphosphonate, are used to prevent these adverse events.
METHODS
To analyze the efficacy of denosumab versus pamidronate, we used the TriNetX research platform and compared the outcomes of pathologic fracture, spinal cord compression, and overall 5-year survival rate between each pharmacotherapy.
RESULTS
There was no statistical difference for an increased risk in pathological fractures (2.7% vs. 2.8%, = 0.88), spinal cord compression (2.6% vs. 2.7%, = 0.88), or 5-year survival rate (45.5% vs. 52.4%, = 0.78) for the denosumab cohort versus the pamidronate cohort.
CONCLUSION
Since neither therapy showed an increased risk in the adverse effects measured in this study, factors such as patient preference, financial costs, and additional side effects of each medication should be taken into consideration when choosing a therapy for bone metastases in patients with breast cancer.
PubMed: 38174029
DOI: 10.1080/08998280.2023.2276623 -
CMAJ : Canadian Medical Association... Dec 2023
Topics: Humans; Pamidronate; Scleritis; Uveitis, Anterior; Diphosphonates
PubMed: 38110218
DOI: 10.1503/cmaj.230859 -
Materials (Basel, Switzerland) Nov 2023The near-infrared (NIR) fluorescence imaging modality has great potential for application in biomedical imaging research owing to its unique characteristics, such as low...
The near-infrared (NIR) fluorescence imaging modality has great potential for application in biomedical imaging research owing to its unique characteristics, such as low tissue autofluorescence and noninvasive visualization with high spatial resolution. Although a variety of NIR fluorophores are continuously reported, the commercially available NIR fluorophores are still limited, owing to complex synthetic processes and poor physicochemical properties. To address this issue, a small molecular NIR fluorophore (SMF800) was designed and developed in the present work to improve in vivo target-specific fluorescence imaging. After conjugation with pamidronate (PAM) and bovine serum albumin (BSA), the SMF800 conjugates exhibited successful in vivo targeting in bone and tumor tissues with low background uptake, respectively. The improved in vivo performance of the SMF800 conjugate demonstrated that the small molecular NIR fluorophore SMF800 can be widely used in a much broader range of imaging applications. The structure of SMF800, which was developed by considering two important physicochemical properties, water solubility and conjugatability, is first introduced. Therefore, this work suggests a simple and rational approach to design small, hydrophilic, and conjugatable NIR fluorophores for targeted bioimaging.
PubMed: 38005156
DOI: 10.3390/ma16227227 -
ACS Applied Bio Materials Dec 2023Bisphosphonate (BP)-based treatments have been extensively prescribed for bone-related conditions, particularly for osteoporosis. Their low bioavailability creates the...
Bisphosphonate (BP)-based treatments have been extensively prescribed for bone-related conditions, particularly for osteoporosis. Their low bioavailability creates the need for prescribed dosage increase to reach therapeutic levels but generates a plethora of undesirable side effects. A viable approach to alleviating these issues is to design and exploit controlled release strategies. Herein, the controlled release profiles of 15 structurally characterized BPs (actual drugs and structural analogs) were thoroughly studied from tablets containing three (cellulose, lactose, and silica) or two (cellulose, and silica) excipients in human stomach-simulated pH conditions. The BPs were of two types, alkyl-BPs and amino-BPs. Alkyl-BPs included four derivatives of etidronate (acid, disodium, tetra-sodium, and monopotassium forms), medronic acid, and three analogs of etidronate, in which the -CH group was replaced by the moieties -H, -CHCHCH, and -CHCHCHCHCH. Amino-BPs included the commercial drugs pamidronate, alendronate, neridronate, and ibandronate, as well as three analog compounds. Release curves were constructed based on data taken from H NMR peak integration and were expressed as "% BP release" vs time. The controlled release profiles (initial release rate, plateau value, etc.) were correlated with certain structural features (number of hydrogen and metal-oxygen bonds), showing that the molecular and crystal lattice features of each BP profoundly influence its release characteristics. It was concluded that for all BPs, in general, the initial rate became lower as the total number of lattice interactions increased. For the alkyl-BPs elongation of the alkyl side chain seems to decelerate the release. Amino-BPs, in general, show slower release than the alkyl-BPs. No adverse effects of alkyl- and amino-BP drugs on NIH3T3 cell viability were noted.
Topics: Mice; Animals; Humans; Delayed-Action Preparations; Etidronic Acid; NIH 3T3 Cells; Diphosphonates; Cellulose; Silicon Dioxide
PubMed: 37982716
DOI: 10.1021/acsabm.3c00770 -
Nature Aging Nov 2023The stem cell theory of aging dictates that a decline in the number and/or function of stem cells causes tissue degeneration and aging; however, it still lacks...
The stem cell theory of aging dictates that a decline in the number and/or function of stem cells causes tissue degeneration and aging; however, it still lacks unequivocal experimental support. Here, using lineage tracing and single-cell transcriptomics, we identify a population of CD133 bone marrow-derived endothelial-like cells (ELCs) as potential endothelial progenitor cells, which contribute to tubular structures in vitro and neovascularization in vivo. We demonstrate that supplementation with wild-type and young ELCs respectively restores neovascularization and extends lifespan in progeric and naturally aged mice. Mechanistically, we identify an upregulation of farnesyl diphosphate synthase (FDPS) in aged CD133 ELCs-a key enzyme in isoprenoid biosynthesis. Overexpression of FDPS compromises the neovascularization capacity of CD133 ELCs, whereas FDPS inhibition by pamidronate enhances neovascularization, improves health measures and extends lifespan in aged mice. These findings highlight stem cell-based strategies for the treatment of progeria and age-related pathologies.
Topics: Mice; Animals; Endothelial Progenitor Cells; Longevity; Neovascularization, Pathologic; Stem Cells
PubMed: 37946040
DOI: 10.1038/s43587-023-00512-z -
Human Immunology Dec 2023Cervical cancer is the second-most prevalent gynecologic cancer in India. It is typically detected in women between the ages of 35 and 44. Cervical cancer is mainly... (Review)
Review
Cervical cancer is the second-most prevalent gynecologic cancer in India. It is typically detected in women between the ages of 35 and 44. Cervical cancer is mainly associated with the human papillomavirus (HPV). The report shows that 70 % of cervical cancer is caused by HPV 16 and 18. There are few therapeutic options and vaccines available for cervical cancer treatment and γδ T cell therapy is one of them. This therapy can kill various types of cancers, including cervical cancer. The major γδ T cell subset is the Vγ9Vδ2 T cell, mainly distributed in peripheral blood which recognize non-MHC peptide antigens and can eliminate MHC-downregulated cancer. Moreover, γδ T cells can express different types of receptors that bind to the molecules of stressed cells, often produced on cancerous cells but absent from healthy tissue. γδ T cells possess both direct and indirect cytotoxic capabilities against malignancies and show potential antitumoral responses. However, γδ T cells also encourage the progression of cancer. Cancer immunotherapy using γδ T cells will be a potential cancer treatment, as well as cervical cancer. This review focused on the γδ T cell and its function in cancer, with special emphasis on cervical cancer. It also focused on the ligand recognition site of γδ T cells, galectin-mediated therapy and pamidronate-treated therapy for cervical cancer. Instead of the great potential of γδ T cell for the eradication of cervical cancer, no comprehensive in-depth review is available to date, so there is a need to jot down the various roles and modes of action and different applications of γδ T cells for cancer research, which we believe will be a handy tool for the researchers and the readers.
Topics: Female; Humans; Adult; Uterine Cervical Neoplasms; Receptors, Antigen, T-Cell, gamma-delta; Immunotherapy; Pamidronate; India
PubMed: 37932183
DOI: 10.1016/j.humimm.2023.110724 -
Pharmaceuticals (Basel, Switzerland) Oct 2023We report a 4-year-old with Gorham-Stout disease (GSD) who was treated with a combination of bisphosphonate, sirolimus, and atenolol. A previously healthy 4-year-old...
We report a 4-year-old with Gorham-Stout disease (GSD) who was treated with a combination of bisphosphonate, sirolimus, and atenolol. A previously healthy 4-year-old girl presented with back pain after falling on her back 2 months prior. Thoracolumbar spine X-ray revealed diffuse compression spinal fractures in T9-L2. Magnetic resonance imaging (MRI) confirmed multiple compression fractures at T9-L5 and revealed a paraspinal mass along the T1-L1 level. Based on clinical, radiological, and histopathological findings, Gorham-Stout disease was diagnosed. Treatment with sirolimus (0.5 mg twice daily, 1.6 mg/m) was initiated and intravenous bisphosphonate (pamidronate, 1 mg/kg for 3 days, total 3 mg/kg every 4 months) was added for back pain; she had immediate improvement in back pain. After 9 months with this treatment, she had a mild increase in paraspinal lymphangiomatosis and aggravation in T9-L5 compression fractures; atenolol was administered. The patient underwent 11 months of combination treatment with bisphosphonate, sirolimus, and atenolol, and MRI showed mild degree of reduction in the paraspinal lesions at L1-L5. The patient is currently in stable condition with no back pain or side effects. The triple combination treatment with bisphosphonate, sirolimus, and atenolol may be helpful in stabilizing the disease course of GSD.
PubMed: 37895975
DOI: 10.3390/ph16101504