Generating 3D images of VMAT plans for predictive models and activation maps associated with plan deliverability.

BACKGROUND: Intensity modulation with dynamic multi-leaf collimator (MLC) and monitor unit (MU) changes across control points (CPs) characterizes volumetric modulated arc therapy (VMAT). The increased uncertainty in plan deliverability required patient-specific quality assurance (PSQA), which remained inefficient upon Quality Assurance (QA) failure. To prevent waste before QA, plan complexity metrics (PCMs) and machine learning models with the metrics were generated, which were lack of providing CP-specific information upon QA failures. PURPOSE: By generating 3D images from digital imaging and comminications in medicine in radiation therapy (DICOM RT) plan, we proposed a predictive model that can estimate the deliverability of VMAT plans and visualize CP-specific regions associated with plan deliverability. METHODS: The patient cohort consisted of 259 and 190 cases for left- and right-breast VMAT treatments, which were split into 235 and 166 cases for training and 24 cases from each treatment for testing the networks. Three-channel 3D images generated from DICOM RT plans were fed into a DenseNet-based deep learning network. To reflect VMAT plan complexity as an image, the first two channels described MLC and MU variations between two consecutive CPs, while the last channel assigned the beam field size. The network output was defined as binary classified PSQA results, indicating deliverability. The predictive performance was assessed by accuracy, sensitivity, specificity, F1-score, and area under the curve (AUC). The gradient-weighted class activation map (Grad-CAM) highlighted the regions of CPs in VMAT plans associated with deliverability, compared against PCMs by Spearman correlation. RESULTS: The DenseNet-based predictive model yielded AUCs of 92.2% and 93.8%, F1-scores of 97.0% and 93.8% and accuracies of 95.8% and 91.7% for the left- and right-breast VMAT cases. Additionally, the specificity of 87.5% for both cases indicated that the predictive model accurately detected QA failing cases. The activation maps significantly differentiated QA failing-labeled from passing-labeled classes for the non-deliverable cases. The PCM with the highest correlation to the Grad-CAM varied from patient cases, implying that plan deliverability would be considered patient-specific. CONCLUSION: This work demonstrated that the deep learning-based network based on visualization of dynamic VMAT plan information successfully predicted plan deliverability, which also provided control-point specific planning parameter information associated with plan deliverability in a patient-specific manner.

Empowering Vision Transformer by Network Hyper-Parameter Selection for Whole Pelvis Prostate Planning Target Volume Auto-Segmentation.

U-Net, based on a deep convolutional network (CNN), has been clinically used to auto-segment normal organs, while still being limited to the planning target volume (PTV) segmentation. This work aims to address the problems in two aspects: 1) apply one of the newest network architectures such as vision transformers other than the CNN-based networks, and 2) find an appropriate combination of network hyper-parameters with reference to recently proposed nnU-Net ("no-new-Net"). VT U-Net was adopted for auto-segmenting the whole pelvis prostate PTV as it consisted of fully transformer architecture. The upgraded version (v.2) applied the nnU-Net-like hyper-parameter optimizations, which did not fully cover the transformer-oriented hyper-parameters. Thus, we tried to find a suitable combination of two key hyper-parameters (patch size and embedded dimension) for 140 CT scans throughout 4-fold cross validation. The VT U-Net v.2 with hyper-parameter tuning yielded the highest dice similarity coefficient (DSC) of 82.5 and the lowest 95% Haussdorff distance (HD95) of 3.5 on average among the seven recently proposed deep learning networks. Importantly, the nnU-Net with hyper-parameter optimization achieved competitive performance, although this was based on the convolution layers. The network hyper-parameter tuning was demonstrated to be necessary even for the newly developed architecture of vision transformers.

AXL is required for hypoxia-mediated hypoxia-inducible factor-1 alpha function in glioblastoma.

Glioblastoma (GBM) is the most aggressive type of central nervous system tumor. Molecular targeting may be important when developing efficient GBM treatment strategies. Sequencing of GBMs revealed that the receptor tyrosine kinase (RTK)/RAS/phosphatidylinositol-3-kinase pathway was altered in 88% of samples. Interestingly, AXL, a member of RTK, was proposed as a promising target in glioma therapy. However, the molecular mechanism of AXL modulation of GBM genesis and proliferation is still unclear. In this study, we investigated the expression and localization of hypoxia-inducible factor-1 alpha (HIF-1α) by AXL in GBM. Both AXL mRNA and protein are overexpressed in GBM. Short-interfering RNA knockdown of AXL in U251-MG cells reduced viability and migration. However, serum withdrawal reduced AXL expression, abolishing the effect on viability. AXL is also involved in hypoxia regulation. In hypoxic conditions, the reduction of AXL decreased the level and nuclear localization of HIF-1α. The co-expression of HIF-1α and AXL was found in human GBM samples but not normal tissue. This finding suggests a mechanism for GBM proliferation and indicates that targeting AXL may be a potential GBM therapeutic. Supplementary Information: The online version contains supplementary material available at 10.1007/s43188-023-00195-z.

Yin Yang 1 is required for PHD finger protein 20-mediated myogenic differentiation in vitro and in vivo.

The development of skeletal muscle requires progression of a highly ordered cascade of events comprising myogenic lineage commitment, myoblast proliferation, and terminal differentiation. The process of myogenesis is controlled by several myogenic transcription factors that act as terminal effectors of signaling cascades and produce appropriate developmental stage-specific transcripts. PHD finger protein 20 (PHF20) is a multidomain protein and subunit of a lysine acetyltransferase complex that acetylates histone H4 and p53, but its function is unclear. Notably, it has been reported that PHF20 knockout mice die shortly after birth and display a wide variety of phenotypes within the skeletal and hematopoietic systems. Therefore, the putative role of PHF20 in myogenic differentiation was further investigated. In the present study, we found that protein and mRNA expression levels of PHF20 were decreased during myogenic differentiation in C2C12 cells. At the same time, Yin Yang 1 (YY1) was also decreased during myogenic differentiation. PHF20 overexpression increased YY1 expression during myogenic differentiation, together with a delay in MyoD expression. PHF20 expression enhanced the transcriptional activity of YY1 while shRNA-mediated depletion of PHF20 resulted in the reduction of YY1 promoter activity in C2C12 cells. In addition, PHF20 directly bounds to the YY1 promoter in C2C12 cells. In a similar manner, YY1 expression was elevated while myosin heavy chain expression was decreased in PHF20 transgenic (TG) mice. Histological analysis revealed abnormalities in the shape and length of muscles in PHF20-TG mice. Furthermore, PHF20-TG muscles slowly regenerated after cardiotoxin injection, indicating that PHF20 affected muscle differentiation and regeneration after injury in vivo. Taken together, these results suggested that PHF20 plays an important role in myogenic differentiation by regulating YY1.

1,2-Dichloropropane (1,2-DCP)-Induced Angiogenesis in Dermatitis.

1,2-Dichloropropane (1,2-DCP) has been used as an industrial solvent and a chemical intermediate, as well as in soil fumigants. Human exposure may occur during its production and industrial use. The target organs of 1,2-DCP are the eyes, respiratory system, liver, kidneys, central nervous system, and skin. Repeated or prolonged contact may cause skin sensitization. In this study, 1,2-DCP was dissolved in corn oil at 0, 2.73, 5.75, and 8.75 mL/kg. The skin of mice treated with 1,2-DCP was investigated using western blotting, hematoxylin and eosin staining, and immunohistochemistry. 1,2-DCP was applied to the dorsal skin and both ears of C57BL/6J mice. The thickness of ears and the epidermis increased significantly following treatment, and the appearance of blood vessels was observed in the dorsal skin. Additionally, the expression of vascular endothelial growth factor, which is tightly associated with neovascularization, increased significantly. The levels of protein kinase-B (PKB), phosphorylated PKB, mammalian target of rapamycin (mTOR), and phosphorylated mTOR, all of which are key components of the phosphoinositide 3-kinase/PKB/mTOR signaling pathway, were also enhanced. Taken together, 1,2-DCP induced angiogenesis in dermatitis through the PI3K/PKB/mTOR pathway in the skin.

A new role for the ginsenoside RG3 in antiaging via mitochondria function in ultraviolet-irradiated human dermal fibroblasts.

BACKGROUND: The efficacy of ginseng, the representative product of Korea, and its chemical effects have been well investigated. The ginsenoside RG3 has been reported to exhibit apoptotic, anticancer, and antidepressant-like effects. METHODS: In this report, the putative effect of RG3 on several cellular function including cell survival, differentiation, development and aging process were evaluated by monitoring each specific marker. Also, mitochondrial morphology and function were investigated in ultraviolet (UV)-irradiated normal human dermal fibroblast cells. RESULTS: RG3 treatment increased the expression of extracellular matrix proteins, growth-associated immediate-early genes, and cell proliferation genes in UV-irradiated normal human dermal fibroblast cells. And, RG3 also resulted in enhanced expression of antioxidant proteins such as nuclear factor erythroid 2-related factor-2 and heme oxygenase-1. In addition, RG3 affects the morphology of UV-induced mitochondria and plays a role in protecting mitochondrial dysfunction. CONCLUSIOIN: RG3 restores mitochondrial adenosine triphosphate (ATP) and membrane potential via its antioxidant effects in skin cells damaged by UV irradiation, leading to an increase in proteins linked with the extracellular matrix, cell proliferation, and antioxidant activity.

S6 kinase 1 plays a key role in mitochondrial morphology and cellular energy flow.

Mitochondrial morphology, which is associated with changes in metabolism, cell cycle, cell development and cell death, is tightly regulated by the balance between fusion and fission. In this study, we found that S6 kinase 1 (S6K1) contributes to mitochondrial dynamics, homeostasis and function. Mouse embryo fibroblasts lacking S6K1 (S6K1-KO MEFs) exhibited more fragmented mitochondria and a higher level of Dynamin related protein 1 (Drp1) and active Drp1 (pS616) in both whole cell extracts and mitochondrial fraction. In addition, there was no evidence for autophagy and mitophagy induction in S6K1 depleted cells. Glycolysis and mitochondrial respiratory activity was higher in S6K1-KO MEFs, whereas OxPhos ATP production was not altered. However, inhibition of Drp1 by Mdivi1 (Drp1 inhibitor) resulted in higher OxPhos ATP production and lower mitochondrial membrane potential. Taken together the depletion of S6K1 increased Drp1-mediated fission, leading to the enhancement of glycolysis. The fission form of mitochondria resulted in lower yield for OxPhos ATP production as well as in higher mitochondrial membrane potential. Thus, these results have suggested a potential role of S6K1 in energy metabolism by modulating mitochondrial respiratory capacity and mitochondrial morphology.

The roles of TRIO and F-actin-binding protein in glioblastoma cells.

TRIO and F-actin-binding protein (TrioBP), which was initially discovered as a binding partner of Trio and F­actin, is a critical factor associated with hearing loss in humans. However, the function of TrioBP in cancer has not been investigated. In the present study, TrioBP expression was indicated to be highly elevated in U87­MG and U343­MG cells. Furthermore, the TrioBP mRNA expression level was markedly increased in U87­MG and U251­MG cells compared with that in cerebral cortex cells, as determined by deep sequencing. Comprehensive analysis of a public TCGA dataset confirmed that TrioBP expression is elevated in patients with glioblastoma. In summary, the present data indicate that TrioBP expression is increased in glioblastoma cell lines and in patients with glioma, suggesting that TrioBP has potential as a diagnostic marker or therapeutic agent for glioma.

GOLGA2 loss causes fibrosis with autophagy in the mouse lung and liver.

Autophagy is a biological recycling process via the self-digestion of organelles, proteins, and lipids for energy-consuming differentiation and homeostasis. The Golgi serves as a donor of the double-membraned phagophore for autophagosome assembly. In addition, recent studies have demonstrated that pulmonary and hepatic fibrosis is accompanied by autophagy. However, the relationships among Golgi function, autophagy, and fibrosis are unclear. Here, we show that the deletion of GOLGA2, encoding a cis-Golgi protein, induces autophagy with Golgi disruption. The induction of autophagy leads to fibrosis along with the reduction of subcellular lipid storage (lipid droplets and lamellar bodies) by autophagy in the lung and liver. GOLGA2 knockout mice clearly demonstrated fibrosis features such as autophagy-activated cells, densely packed hepatocytes, increase of alveolar macrophages, and decrease of alveolar surfactant lipids (dipalmitoylphosphatidylcholine). Therefore, we confirmed the associations among Golgi function, fibrosis, and autophagy. Moreover, GOLGA2 knockout mice may be a potentially valuable animal model for studying autophagy-induced fibrosis.

Mitochondrial transcription factor A (TFAM) is upregulated in glioma.

Mitochondrial transcription factor A (TFAM), which was initially discovered as a transcription factor for mitochondrial DNA, has known to be critical for the regulation of mitochondrial DNA. However the possible involvement of TFAM in cancer is largely unknown. In this study, we have provided some evidence that TFAM may have a potential role in brain tumor. Western blot analysis with anti­TFAM antibody indicated that TFAM is overexpressed in glioblastoma cell lines including U87MG and U251MG. Transcriptome profiling of U87MG and U251MG cells by using deep­sequencing revealed that TFAM transcripts were upregulated in these cells compared to its of cerebral cortex. Confocal microscopic analysis of U251MG cells with anti­TFAM antibody showed that TFAM is located to the dot­like structure close to nucleus, probably mitochondria and endosome. Immunohistochemical analysis of glioma tissue specimens indicated that TFAM is highly upregulated. Bioinformatical analysis with Rembrandt knowledgebase also supported that TFAM mRNA is upregulated in glioma patients. Taken together, the results presented in this study obviously provided the evidence that TFAM was upregulated in glioma cell line and glioma tissue specimens. Therefore TFAM may be a novel diagnostic marker and therapeutic target for glioma and other cancer.

Benign fibrous histiocytoma in the mandible.

PURPOSE: Benign fibrous histiocytoma (BFH) is a very rare benign tumor occurring in the jaw. The purpose of this article is to describe the clinical, radiographic, and microscopic appearance of BFH occurring in the mandible. STUDY DESIGN: A 42-year-old man had an asymptomatic swelling of the left mandibular posterior area. RESULTS: Conventional radiographs revealed a well-defined multilocular radiolucency involving the left mandibular body, ramus, coronoid process, and condylar head. The lesion showed the thinning and expansion of the cortex. There were many thin, indistinct septa in the lesion. The computed tomography (CT) scans showed bone destruction with marginal sclerosis and a heterogeneous soft-tissue mass expanding the mandible. Microscopic examination revealed a cellular tumor composed of uniform spindle-shaped cells arranged in a storiform pattern. CONCLUSIONS: BFH is a very rare benign tumor occurring in the jaw, so more cases should be reported to understand the characteristics of the lesion.