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1.
Biomed Pharmacother ; 174: 116490, 2024 May.
Article in English | MEDLINE | ID: mdl-38554526

ABSTRACT

Liver fibrosis is a chronic liver disease caused by prolonged liver injuries. Excessive accumulation of extracellular matrix replaces the damaged hepatocytes, leading to fibrous scar formation and fibrosis induction. Lactoferrin (LF) is a glycoprotein with a conserved, monomeric signal polypeptide chain, exhibiting diverse physiological functions, including antioxidant, anti-inflammatory, antibacterial, antifungal, antiviral, and antitumoral activities. Previous study has shown LF's protective role against chemically-induced liver fibrosis in rats. However, the mechanisms of LF in liver fibrosis are still unclear. In this study, we investigated LF's mechanisms in thioacetamide (TAA)-induced liver fibrosis in rats and TGF-ß1-treated HSC-T6 cells. Using ultrasonic imaging, H&E, Masson's, and Sirius Red staining, we demonstrated LF's ability to improve liver tissue damage and fibrosis induced by TAA. LF reduced the levels of ALT, AST, and hydroxyproline in TAA-treated liver tissues, while increasing catalase levels. Additionally, LF treatment decreased mRNA expression of inflammatory factors such as Il-1ß and Icam-1, as well as fibrogenic factors including α-Sma, Collagen I, and Ctgf in TAA-treated liver tissues. Furthermore, LF reduced TAA-induced ROS production and cell death in FL83B cells, and decreased α-SMA, Collagen I, and p-Smad2/3 productions in TGF-ß1-treated HSC-T6 cells. Our study highlights LF's ability to ameliorate TAA-induced hepatocyte damage, oxidative stress, and liver fibrosis in rats, potentially through its inhibitory effect on HSC activation. These findings suggest LF's potential as a therapeutic agent for protecting against liver injuries and fibrosis.


Subject(s)
Hepatic Stellate Cells , Lactoferrin , Liver Cirrhosis , Thioacetamide , Animals , Hepatic Stellate Cells/drug effects , Hepatic Stellate Cells/metabolism , Hepatic Stellate Cells/pathology , Lactoferrin/pharmacology , Lactoferrin/therapeutic use , Male , Liver Cirrhosis/chemically induced , Liver Cirrhosis/drug therapy , Liver Cirrhosis/pathology , Liver Cirrhosis/metabolism , Rats , Cell Line , Rats, Sprague-Dawley , Liver/drug effects , Liver/pathology , Liver/metabolism , Oxidative Stress/drug effects , Reactive Oxygen Species/metabolism , Transforming Growth Factor beta1/metabolism , Signal Transduction/drug effects
2.
Cell Biosci ; 14(1): 18, 2024 Feb 03.
Article in English | MEDLINE | ID: mdl-38308335

ABSTRACT

BACKGROUND: The development of alcohol-associated liver disease (ALD) is influenced by the amount and duration of alcohol consumption. The resulting liver damage can range from reversible stages, such as steatosis, steatohepatitis and alcoholic fibrosis, to the advanced and irreversible stage of cirrhosis. Aldo-keto reductase family 1 member A1 (AKR1A1) is a member of the aldo-keto reductase family that catalyzes the reduction of aldehyde groups to their corresponding alcohols in an NADPH-dependent manner. AKR1A1 was found to be downregulated in patients diagnosed with ALD. This study aims to interpret the protective effects of AKR1A1 on the development of ALD. METHODS: A 5% alcohol-fed (AF) Akr1a1 knockout (Akr1a1-/-) mouse model and an AML12 hepatocyte model were used. The effects of AKR1A1 on liver function, inflammation, oxidative stress, lipid accumulation, and fibrosis were assessed by ELISA, western blotting, RT‒PCR, and a variety of histological staining methods in AF-induced wild-type (WT) and Akr1a1-/- mice compared to control liquid diet-fed (PF) WT and Akr1a1-/- mice. RESULTS: The results demonstrated that AF-WT mice expressed higher levels of AKR1A1 than WT mice fed a control diet, and they did not show any noticeable liver steatosis. However, AF-Akr1a1-/- mice displayed a lower survival rate and more severe liver injury than AF-WT mice, as demonstrated by increased proinflammatory cytokines, oxidative stress, lipid accumulation, fibrosis, and reduced antioxidant enzymes in their livers. Additionally, elevated levels of 4-HNE and p53 phosphorylation were observed in AF-Akr1a1-/- mice, suggesting that the loss of AKR1A1 led to increased 4-HNE accumulation and subsequent activation of p53, which contributed to the progression of ALD. Furthermore, in AML12 hepatocytes, Akr1a1 knockdown aggravated oxidative stress and steatosis induced by palmitic acid/oleic acid (P/O) inflammation induced by lipopolysaccharide (LPS), and fibrosis induced by TGF-ß1. CONCLUSIONS: This loss-of-function study suggests that AKR1A1 plays a liver-protective role during chronic alcohol consumption by reducing the accumulation of 4-HNE and inhibiting 4-HNE-mediated p53 activation.

3.
Front Aging Neurosci ; 15: 1110434, 2023.
Article in English | MEDLINE | ID: mdl-36998317

ABSTRACT

Introduction: Effective connectivity (EC), the causal influence that functional activity in a source brain location exerts over functional activity in a target brain location, has the potential to provide different information about brain network dynamics than functional connectivity (FC), which quantifies activity synchrony between locations. However, head-to-head comparisons between EC and FC from either task-based or resting-state functional MRI (fMRI) data are rare, especially in terms of how they associate with salient aspects of brain health. Methods: In this study, 100 cognitively-healthy participants in the Bogalusa Heart Study aged 54.2 ± 4.3years completed Stroop task-based fMRI, resting-state fMRI. EC and FC among 24 regions of interest (ROIs) previously identified as involved in Stroop task execution (EC-task and FC-task) and among 33 default mode network ROIs (EC-rest and FC-rest) were calculated from task-based and resting-state fMRI using deep stacking networks and Pearson correlation. The EC and FC measures were thresholded to generate directed and undirected graphs, from which standard graph metrics were calculated. Linear regression models related graph metrics to demographic, cardiometabolic risk factors, and cognitive function measures. Results: Women and whites (compared to men and African Americans) had better EC-task metrics, and better EC-task metrics associated with lower blood pressure, white matter hyperintensity volume, and higher vocabulary score (maximum value of p = 0.043). Women had better FC-task metrics, and better FC-task metrics associated with APOE-ε4 3-3 genotype and better hemoglobin-A1c, white matter hyperintensity volume and digit span backwards score (maximum value of p = 0.047). Better EC rest metrics associated with lower age, non-drinker status, and better BMI, white matter hyperintensity volume, logical memory II total score, and word reading score (maximum value of p = 0.044). Women and non-drinkers had better FC-rest metrics (value of p = 0.004). Discussion: In a diverse, cognitively healthy, middle-aged community sample, EC and FC based graph metrics from task-based fMRI data, and EC based graph metrics from resting-state fMRI data, were associated with recognized indicators of brain health in differing ways. Future studies of brain health should consider taking both task-based and resting-state fMRI scans and measuring both EC and FC analyses to get a more complete picture of functional networks relevant to brain health.

4.
Life Sci ; 317: 121411, 2023 Mar 15.
Article in English | MEDLINE | ID: mdl-36682523

ABSTRACT

AIMS: Rheumatoid arthritis (RA) is a chronic autoimmune disease. Its pathological features are synovial inflammation, bone erosion, and joint structural damages. Our previous studies have shown that kefir peptides (KPs) can reduce cardiovascular disease, osteoporosis and renal inflammation. In this study, we further evaluate the efficacy of KPs on adjuvant-induced arthritis (AIA) in a rat model. MAIN METHODS: After the 14th day of adjuvant induction, rats were subsequently orally administered KPs (83 or 166 mg/day/kg) or tofacitinib (6.2 mg/day/kg) for 14 days. On the 28th day, the rats were anesthetized with isoflurane for ultrasonic, in vivo imaging system (IVIS), and radiographic imaging and then sacrificed for ankle tissues collection and analysis. In vitro, IL-1ß-treated human synovial cells (SW982) were subjected to anti-arthritis mechanism study in the presence of KPs. KEY FINDINGS: The results of ultrasonography, radiograph, histology, the expression of matrix metalloproteinases (MMPs), inflammatory cytokines and RANKL/OPG ratio demonstrated decreasing severity of synovitis and bone erosion in the ankle joints after KPs treatment. Activation of the NF-κB and MAPK pathways was significantly reduced in KPs treated AIA group. Furthermore, KPs attenuated IL-1ß-induced inflammatory cytokine production and the expression of MMPs in a human synovial cell line SW982. These results demonstrated that KPs alleviated adjuvant-induced arthritis in rats by inhibiting IL-1ß-related inflammation and MMPs production. SIGNIFICANCE: We concluded that KPs can exhibit anti-inflammatory effects by reducing the levels of macrophage-related inflammatory cytokines and MMPs, thus alleviating bone erosion in the ankle joint and constituting a potential therapeutic strategy for rheumatoid arthritis.


Subject(s)
Arthritis, Experimental , Arthritis, Rheumatoid , Kefir , Rats , Humans , Animals , Down-Regulation , Anti-Inflammatory Agents/pharmacology , Arthritis, Rheumatoid/drug therapy , Inflammation/pathology , Cytokines/metabolism , Arthritis, Experimental/drug therapy , Matrix Metalloproteinases/metabolism
5.
Int J Mol Sci ; 23(22)2022 Nov 16.
Article in English | MEDLINE | ID: mdl-36430662

ABSTRACT

Asthma is a chronic respiratory disease with symptoms such as expiratory airflow narrowing and airway hyperresponsiveness (AHR). Millions of people suffer from asthma and are at risk of life-threatening conditions. Lactoferrin (LF) is a glycoprotein with multiple physiological functions, including antioxidant, anti-inflammatory, antimicrobial, and antitumoral activities. LF has been shown to function in immunoregulatory activities in ovalbumin (OVA)-induced delayed type hypersensitivity (DTH) in mice. Hence, the purpose of this study was to investigate the roles of LF in AHR and the functions of dendritic cells (DCs) and Th2-related responses in asthma. Twenty 8-week-old male BALB/c mice were divided into normal control (NC), ovalbumin (OVA)-sensitized, and OVA-sensitized with low dose of LF (100 mg/kg) or high dose of LF (300 mg/kg) treatment groups. The mice were challenged by intranasal instillation with 5% OVA on the 21st to 27th day after the start of the sensitization period. The AHR, cytokines in bronchoalveolar lavage fluid, and pulmonary histology of each mouse were measured. Serum OVA-specific IgE and IgG1 and OVA-specific splenocyte responses were further detected. The results showed that LF exhibited protective effects in ameliorating AHR, as well as lung inflammation and damage, in reducing the expression of Th2 cytokines and the secretion of allergen-specific antibodies, in influencing the functions of DCs, and in decreasing the level of Th2 immune responses in a BALB/c mouse model of OVA-induced allergic asthma. Importantly, we demonstrated that LF has practical application in reducing DC-induced Th2 cell responses in asthma. In conclusion, LF exhibits anti-inflammation and immunoregulation activities in OVA-induced allergic asthma. These results suggest that LF may act as a supplement to prevent asthma-induced lung injury and provide an additional agent for reducing asthma severity.


Subject(s)
Asthma , Lactoferrin , Th2 Cells , Animals , Male , Mice , Asthma/chemically induced , Asthma/drug therapy , Cytokines/metabolism , Lactoferrin/pharmacology , Lactoferrin/therapeutic use , Lactoferrin/metabolism , Mice, Inbred BALB C , Ovalbumin , Th2 Cells/drug effects , Th2 Cells/metabolism , Dendritic Cells/drug effects , Dendritic Cells/metabolism
6.
J Appl Clin Med Phys ; 23(11): e13639, 2022 Nov.
Article in English | MEDLINE | ID: mdl-35570395

ABSTRACT

We demonstrate a virtual pretreatment patient-specific QA (PSQA) procedure that is capable of quantifying dosimetric effect on patient anatomy for both intensity modulated radiotherapy (IMRT) and volumetric modulated arc therapy (VMAT). A machine learning prediction model was developed to use linear accelerator parameters derived from the DICOM-RT plan to predict delivery discrepancies at treatment delivery (defined as the difference between trajectory log file and DICOM-RT) and was coupled with an independent Monte Carlo dose calculation algorithm for dosimetric analysis. Machine learning models for IMRT and VMAT were trained and validated using 120 IMRT and 206 VMAT fields of prior patients, with 80% assigned for iterative training and testing, and 20% for post-training validation. Various prediction models were trained and validated, with the final models selected for clinical implementation being a boosted tree and bagged tree for IMRT and VMAT, respectively. After validation, these models were then applied clinically to predict the machine parameters at treatment delivery for 7 IMRT plans from various sites (61 fields) and 10 VMAT multi-target intracranial radiosurgery plans (35 arcs) and compared to the dosimetric effect calculated directly from trajectory log files. Dose indices tracked for targets and organs at risk included dose received by 99%, 95%, and 1% of the volume, mean dose, percent of volume receiving 25%-100% of the prescription dose. The average coefficient of determination (r2 ) when comparing intra-field predicted and actual delivery error was 0.987 ± 0.012 for IMRT and 0.895 ± 0.095 for VMAT, whereas r2 when comparing inter-field predicted versus actual delivery error was 0.982 for IMRT and 0.989 for VMAT. Regarding dosimetric analysis, r2 when comparing predicted versus actual dosimetric changes for all dose indices was 0.966 for IMRT and 0.907 for VMAT. Prediction models can be used to anticipate the dosimetric effect calculated from trajectory files and have potential as a "delivery-free" pretreatment analysis to enhance PSQA.


Subject(s)
Radiotherapy Planning, Computer-Assisted , Radiotherapy, Intensity-Modulated , Humans , Radiotherapy Dosage , Radiotherapy Planning, Computer-Assisted/methods , Radiotherapy, Intensity-Modulated/methods , Organs at Risk , Radiometry
7.
J Clin Med ; 11(8)2022 Apr 12.
Article in English | MEDLINE | ID: mdl-35456253

ABSTRACT

To develop a method of estimating surface dose in whole breast irradiation, we used an anthropomorphic phantom with accessories for the simulation of different breast sizes. The surface points, which are measured by TLDs, are set along with two main directions, superior-inferior and medial-lateral. The incident angle between the photon beam and the surface and the doses at 1 cm beneath the surface at every point are assessed by a computerized treatment planning system (cTPS). With the prescription dose of 200 cGy, the average surface doses under tangential irradiation are 97.73 (±14.96) cGy, 99.90 (±10.73) cGy, and 105.26 (±9.21) cGy for large, medium, and small breast volumes, respectively. The surface dose increased in the model of small breast volume without significance (p = 0.39). The linear analysis between surface dose and the incident angle is y = 0.5258x + 69.648, R2 = 0.7131 (x: incident angle and y: surface dose). We develop the percentage of skin surface dose with reference to a depth of 1 cm (PSDR1cm) to normalize the inhomogeneous dose. The relationship between incident angle and PSDR1cm is y = 0.1894x + 36.021, R2 = 0.6536 (x: incident angle and y: PSDR1cm) by linear analysis. In conclusion, the surface dose in whole breast irradiation could be estimated from this linear relationship between PSDR1cm and incident angle in daily clinical practice by cTPS. Further in vivo data should be studied to verify this formula.

8.
J Appl Clin Med Phys ; 22(7): 36-43, 2021 Jul.
Article in English | MEDLINE | ID: mdl-34165217

ABSTRACT

PURPOSE: In this study, we evaluate and compare single isocenter multiple target VMAT (SIMT) and Conformal Arc Informed VMAT (CAVMAT) radiosurgery's sensitivity to uncertainties in dosimetric leaf gap (DLG) and treatment delivery. CAVMAT is a novel planning technique that uses multiple target conformal arcs as the starting point for limited inverse VMAT optimization. METHODS: All VMAT and CAVMAT plans were recalculated with DLG values of 0.4, 0.8, and 1.2 mm. DLG effect on V6Gy [cc], V12Gy [cc], and V16Gy [cc], and target dose was evaluated. Plans were delivered to a Delta4 (ScandiDos, Madison, WI) phantom and gamma analysis performed with varying criteria. Log file analysis was performed to evaluate MLC positional error. Sixteen targets were delivered to a SRS MapCHECK (Sun Nuclear Corp., Melbourne, FL) to evaluate VMAT and CAVMAT's dose difference (DD) as a function of DLG. RESULTS: VMAT's average maximum and minimum target dose sensitivity to DLG was 9.08 ±3.50%/mm and 9.50 ± 3.30%/mm, compared to 3.20 ± 1.60%/mm and 4.72 ± 1.60%/mm for CAVMAT. For VMAT, V6Gy [cc], V12Gy [cc], and V16Gy [cc] sensitivity was 35.83 ± 9.50%/mm, 34.12 ± 6.60%/mm, and 39.23 ± 8.40%/mm. In comparison, CAVMAT's sensitivity was 23.19 ± 4.50%/mm, 22.45 ± 4.40%/mm, and 24.88 ± 4.90%/mm, respectively. Upon delivery to the Delta4 , CAVMAT offered superior dose agreement compared to VMAT. For a 1%/1 mm gamma analysis, VMAT and CAVMAT had a passing rate of 94.53 ± 4.40% and 99.28 ± 1.70%, respectively. CAVMAT was more robust to DLG variation, with the SRS MapCHECK plans yielding an absolute average DD sensitivity of 2.99 ± 1.30%/mm compared to 5.07 ± 1.10%/mm for VMAT. Log files demonstrated minimal differences in MLC positional error for both techniques. CONCLUSIONS: CAVMAT remains robust to delivery uncertainties while offering a target dose sensitivity to DLG less than half that of VMAT, and 65% of that of VMAT for V6Gy [cc], V12Gy [cc], and V16Gy [cc]. The superior dose agreement and reduced sensitivity of CAVMAT to DLG uncertainties indicate promise as a robust alternative to VMAT for SIMT SRS.


Subject(s)
Radiosurgery , Radiotherapy, Intensity-Modulated , Humans , Radiotherapy Dosage , Radiotherapy Planning, Computer-Assisted , Uncertainty
9.
Oncol Lett ; 21(4): 304, 2021 Apr.
Article in English | MEDLINE | ID: mdl-33732380

ABSTRACT

Skin cancer is caused by abnormal proliferation, gene regulation and mutation of epidermis cells. Compound C is commonly used as an inhibitor of AMP-activated protein kinase (AMPK), which serves as an energy sensor in cells. Recently, compound C has been reported to induce apoptotic and autophagic death in various skin cancer cell lines via an AMPK-independent pathway. However, the signaling pathways activated in compound C-treated cancer cells remain unclear. The present oligodeoxynucleotide-based microarray screening assay showed that the mRNA expression of the zinc-finger transcription factor early growth response-1 (EGR-1), which helps regulate cell cycle progression and cell survival, was significantly upregulated in compound C-treated skin cancer cells. Compound C was demonstrated to induce EGR-1 mRNA and protein expression in a time and dose-dependent manner. Confocal imaging showed that compound C-induced EGR-1 protein expression was localized in the nucleus. Compound C was demonstrated to activate extracellular signal-regulated kinase (ERK) phosphorylation. Inhibition of this compound C-induced ERK phosphorylation downregulated the mRNA and protein expression of EGR-1. In addition, removal of compound C-induced reactive oxygen species (ROS) not only decreased ERK phosphorylation, but also inhibited compound C-induced EGR-1 expression. A functional assay showed that knock down of EGR-1 expression in cancer cells decreased the survival rate while also increasing caspase-3 activity and apoptotic marker expression after compound C treatment. However, no difference in autophagy marker light chain 3-II protein expression was observed between compound C-treated control cells and EGR-1-knockdown cells. Thus, it was concluded that that EGR-1 may antagonize compound C-induced apoptosis but not compound C-induced autophagy through the ROS-mediated ERK activation pathway.

10.
J Invest Dermatol ; 141(9): 2219-2228.e8, 2021 09.
Article in English | MEDLINE | ID: mdl-33744296

ABSTRACT

Lysosomal adaptation is a cellular physiological process in which the number and function of lysosomes are regulated at the transcriptional and post-transcriptional levels in response to extracellular and/or intracellular cues or lysosomal damage. Imiquimod (IMQ), a synthetic toll-like receptor 7 ligand with hydrophobic and weak basic properties, exhibits both antitumor and antiviral activity against various skin malignancies as a clinical treatment. Interestingly, IMQ has been suggested to be highly concentrated in the lysosomes of plasmacytoid dendritic cells, indicating that IMQ could modulate lysosome function after sequestration in the lysosome. In this study, we found that IMQ not only induced lysosomal membrane permeabilization and dysfunction but also increased lysosome biogenesis to achieve lysosomal adaptation in cancer cells. IMQ-induced ROS production but not lysosomal sequestration of IMQ was the major cause of lysosomal adaptation. Moreover, IMQ-induced lysosomal adaptation occurred through lysosomal calcium ion release and activation of the calcineurin/TFEB axis to promote lysosome biogenesis. Finally, depletion of TFEB sensitized skin cancer cells to IMQ-induced apoptosis in vitro and in vivo. In summary, a disruption of lysosomal adaptation might represent a therapeutic strategy for synergistically enhancing the cytotoxicity of IMQ in skin cancer cells.


Subject(s)
Antineoplastic Agents/therapeutic use , Imiquimod/therapeutic use , Lysosomes/drug effects , Stomach Neoplasms/drug therapy , Animals , Apoptosis , Basic Helix-Loop-Helix Leucine Zipper Transcription Factors/genetics , Calcineurin/metabolism , Calcium Signaling , Humans , Mice , Mice, Inbred C57BL , Mice, Knockout , Reactive Oxygen Species/metabolism , Xenograft Model Antitumor Assays
11.
Med Phys ; 48(3): 978-990, 2021 Mar.
Article in English | MEDLINE | ID: mdl-33332618

ABSTRACT

PURPOSE: Multileaf collimator (MLC) delivery discrepancy between planned and actual (delivered) positions have detrimental effect on the accuracy of dose distributions for both IMRT and VMAT. In this study, we evaluated the consistency of MLC delivery discrepancies over the course of treatment and over time to verify that a predictive machine learning model would be applicable throughout the course of treatment. Next, the MLC and gantry positions recorded in prior trajectory log files were analyzed to build a machine learning algorithm to predict MLC positional discrepancies during delivery for a new treatment plan. An open source tool was developed and released to predict the MLC positional discrepancies at treatment delivery for any given plan. METHODS: Trajectory log files of 142 IMRT plans and 125 VMAT plans from 9 Varian TrueBeam linear accelerators were collected and analyzed. The consistency of delivery discrepancy over patient-specific quality assurance (QA) and patient treatment deliveries was evaluated. Data were binned by treatment site and machine type to determine their relationship with MLC and gantry angle discrepancies. Motion-related parameters including MLC velocity, MLC acceleration, control point, dose rate, and gravity vector, gantry velocity and gantry acceleration, where applicable, were analyzed to evaluate correlations with MLC and gantry discrepancies. Several regression models, such as simple/multiple linear regression, decision tree, and ensemble method (boosted tree and bagged tree model) were used to develop a machine learning algorithm to predict MLC discrepancy based on MLC motion parameters. RESULTS: MLC discrepancies at patient-specific QA differed from those at patient treatment deliveries by a small (mean = 0.0021 ± 0.0036 mm, P = 0.0089 for IMRT; mean = 0.0010 ± 0.0016 mm, P = 0.0003 for VMAT) but statistically significant amount, likely due to setting the gantry angle to zero for QA in IMRT. MLC motion parameters, MLC velocity and gravity vector, showed significant correlation (P < 0.001) with MLC discrepancy, especially MLC velocity, which had an approximately linear relationship (slope = -0.0027, P < 0.001, R2  = 0.79). Incorporating MLC motion parameters, the final generalized model trained by data from all linear accelerators can predict MLC discrepancy to a high degree of accuracy with high correlation (R2  = 0.86) between predicted and actual MLC discrepancies. The same prediction results were found across different treatment sites and linear accelerators. CONCLUSION: We have developed a machine learning model using trajectory log files to predict the MLC discrepancies during delivery. This model has been a released as a research tool in which a DICOM-RT with predicted MLC positions can be generated using the original DICOM-RT file as input. This tool can be used to simulate radiotherapy treatment delivery and may be useful for studies evaluating plan robustness and dosimetric uncertainties from treatment delivery.


Subject(s)
Algorithms , Radiotherapy, Intensity-Modulated , Electrical Equipment and Supplies , Humans , Particle Accelerators , Phantoms, Imaging , Radiotherapy Dosage , Radiotherapy Planning, Computer-Assisted
12.
J Dermatol Sci ; 98(3): 152-162, 2020 Jun.
Article in English | MEDLINE | ID: mdl-32376151

ABSTRACT

BACKGROUND: Mitochondrial homeostasis is a highly dynamic process involving continuous fission and fusion cycles and mitophagy to maintain mitochondrial functionality. Imiquimod (IMQ), a Toll-like receptor (TLR) 7 ligand, is used to treat various skin malignancies. IMQ also induces apoptotic and autophagic cell death in various cancers through a TLR7-independent pathway. OBJECTIVE: To investigate whether IMQ-induced ROS production is involved in mitochondrial dysfunction, mitochondrial fragmentation and mitophagy in skin cancer cells. METHODS: BCC/KMC-1, B16F10 and A375 skin cancer cells, AGS gastric cancer cells and primary human keratinocytes were treated with 50 µg/mL IMQ. After 4 h, ROS were detected by CM-H2DCFDA, DHE, and MitoSOX Red staining. After 24 h, cell viability and the mitochondrial membrane potential were evaluated by a CCK-8 assay and JC-1 staining, respectively. Oxygen consumption was assessed with an Oroboros instrument. Mitochondrial morphology and mitophagy were evaluated by MitoTracker and LysoTracker staining. Mitochondrial dynamics markers, including MFN-1, DRP-1 and OPA1, and mitophagy markers, including LC3, S65-phosphorylated ubiquitin, PINK1 and TOM20, were detected by immunoblotting. RESULTS: IMQ not only induced severe ROS production but also resulted in increased mitochondrial membrane potential loss, mitochondrial fission and mitophagy and decreased oxygen consumption in skin cancer cells compared with normal keratinocytes. Pretreatment with the antioxidant NAC reduced IMQ-induced ROS production and attenuated IMQ-induced mitochondrial fission and mitophagy in skin cancer cells. CONCLUSIONS: IMQ-induced ROS might be associated with mitochondrial dysfunction, mitochondrial fission and mitophagy in cancer cells. Alleviating IMQ-induced ROS production would reduce mitochondrial fission-to-fusion skewing and further reduce IMQ-induced mitophagy.


Subject(s)
Antineoplastic Agents/pharmacology , Imiquimod/pharmacology , Mitochondria/drug effects , Reactive Oxygen Species/metabolism , Skin Neoplasms/drug therapy , Animals , Antineoplastic Agents/therapeutic use , Antioxidants/pharmacology , Cell Line, Tumor , Cell Survival/drug effects , Free Radical Scavengers/pharmacology , Humans , Imiquimod/therapeutic use , Keratinocytes , Mice , Mitochondria/metabolism , Mitochondrial Dynamics/drug effects , Mitophagy/drug effects , Primary Cell Culture , Reactive Oxygen Species/antagonists & inhibitors , Signal Transduction/drug effects , Skin Neoplasms/pathology
13.
J Invest Dermatol ; 140(9): 1771-1783.e6, 2020 09.
Article in English | MEDLINE | ID: mdl-32035924

ABSTRACT

The induction of immunogenic cell death (ICD) in cancer cells triggers specific immune responses against the same cancer cells. Imiquimod (IMQ) is a synthetic ligand of toll-like receptor 7 that exerts antitumor activity by stimulating cell-mediated immunity or by directly inducing apoptosis. Whether IMQ causes tumors to undergo ICD and elicits a specific antitumor immune response is unknown. We demonstrated that IMQ-induced ICD-associated features, including the surface exposure of calreticulin and the secretion of adenosine triphosphate and HMGB1, were mediated by ROS and endoplasmic reticulum stress. In a B16F10 melanoma mouse model, vaccinating mice with IMQ-induced ICD cell lysate or directly injecting IMQ in situ reduced tumor growth that was mediated by inducing tumor-specific T-cell proliferation, promoting tumor-specific cytotoxic killing by CD8+ T cells, and increasing the infiltration of various immune cells into tumor lesions. The ICD-associated features were crucial in the induction of specific antitumor immunity in vivo. The glycolytic inhibitor 2-deoxyglucose enhanced IMQ-induced ICD-associated features and strengthened the antitumor immunity mediated by IMQ-induced ICD cell lysate in p53-mutant cancer cells, which were IMQ-resistant in vitro. We conclude that IMQ is an authentic ICD inducer and provide a concept connecting IMQ-induced cancer cell death and antitumor immune responses.


Subject(s)
Antineoplastic Combined Chemotherapy Protocols/pharmacology , Deoxyglucose/pharmacology , Imiquimod/pharmacology , Immunogenic Cell Death/drug effects , Melanoma, Experimental/drug therapy , Skin Neoplasms/drug therapy , Animals , Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Cell Line, Tumor/transplantation , Deoxyglucose/therapeutic use , Drug Synergism , Glycolysis/drug effects , Humans , Imiquimod/therapeutic use , Male , Melanoma, Experimental/immunology , Melanoma, Experimental/pathology , Mice , Skin Neoplasms/immunology , Skin Neoplasms/pathology
14.
Biomed Phys Eng Express ; 7(1)2020 12 04.
Article in English | MEDLINE | ID: mdl-34037535

ABSTRACT

Purpose:Trajectory log files are increasingly being utilized clinically for machine and patient specific QA. The process of converting the DICOM-RT plan to a deliverable trajectory by the linac control software introduces some uncertainty that is inherently incorporated into measurement-based patient specific QA but is not necessarily included for trajectory log file-based methods. Roughly half of prior studies have included this uncertainty in the analysis while the remaining studies have ignored it, and it has yet to be quantified in the literature.Methods:We collected DICOM-RT files from the treatment planning system and the trajectory log files from four TrueBeam linear accelerators for 25 IMRT and 10 VMAT plans. We quantified the DICOM-RT Conversion to Trajectory Residual (DCTR, difference between 'planned' MLC position from TPS DICOM-RT file and 'expected' MLC position (the deliverable MLC positions calculated by the linac control software) from trajectory log file) and compared it to the discrepancy between actual and expected machine parameters recorded in trajectory log files.Results:RMS of the DCTR was 0.0845 mm (range of RMS per field/arc: 0.0173-0.1825 mm) for 35 plans (114 fields/arcs) and was independent of treatment technique, with a maximum observed discrepancy at any control point of 0.7255 mm. DCTR was correlated with MLC velocity and was consistent over the course of treatment and over time, with a slight change in magnitude observed after a linac software upgrade. For comparison, the RMS of trajectory log file reported delivery error for moving MLCs was 0.0205 mm, thus DCTR is about four times the recorded delivery error in the trajectory log file.Conclusion:The uncertainty introduced from the conversion process by the linac control software from DICOM-RT plan to a deliverable trajectory is 3-4 times larger than the discrepancy between actual and expected machine parameters recorded in trajectory log files. This uncertainty should be incorporated into the analysis when using trajectory log file-based methods for analyzing MLC performance or patient-specific QA.


Subject(s)
Radiotherapy Planning, Computer-Assisted , Radiotherapy, Intensity-Modulated , Data Analysis , Humans , Particle Accelerators , Phantoms, Imaging , Radiotherapy Dosage , Software
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