Selective Tumor Inhibition Effect of Drug-Free Layered Double Hydroxide-Based Films via Responding to Acidic Microenvironment.

Nickel-titanium alloy stents are widely used in the interventional treatment of various malignant tumors, and it is important to develop nickel-titanium alloy stents with selective cancer-inhibiting and antibacterial functions to avoid malignant obstruction caused by tumor invasion and bacterial colonization. In this work, an acid-responsive layered double hydroxide (LDH) film was constructed on the surface of a nickel-titanium alloy by hydrothermal treatment. The release of nickel ions from the film in the acidic tumor microenvironment induces an intracellular oxidative stress response that leads to cell death. In addition, the specific surface area of LDH nanosheets could be further regulated by heat treatment to modulate the release of nickel ions in the acidic microenvironment, allowing the antitumor effect to be further enhanced. This acid-responsive LDH film also shows a good antibacterial effect against S. aureus and E. coli. Besides, the LDH film prepared without the introduction of additional elements maintains low toxicity to normal cells in a normal physiological environment. This work offers some guidance for the design of a practical nickel-titanium alloy stent for the interventional treatment of tumors.

Establishment of orthotopic osteosarcoma animal models in immunocompetent rats through muti-rounds of in-vivo selection.

Immunodeficient murine models are usually used as the preclinical models of osteosarcoma. Such models do not effectively simulate the process of tumorigenesis and metastasis. Establishing a suitable animal model for understanding the mechanism of osteosarcoma and the clinical translation is indispensable. The UMR-106 cell suspension was injected into the marrow cavity of Balb/C nude mice. Tumor masses were harvested from nude mice and sectioned. The tumor fragments were transplanted into the marrow cavities of SD rats immunosuppressed with cyclosporine A. Through muti-rounds selection in SD rats, we constructed orthotopic osteosarcoma animal models using rats with intact immune systems. The primary tumor cells were cultured in-vitro to obtain the immune-tolerant cell line. VX2 tumor fragments were transplanted into the distal femur and parosteal radius of New Zealand white rabbit to construct orthotopic osteosarcoma animal models in rabbits. The rate of tumor formation in SD rats (P1 generation) was 30%. After four rounds of selection and six rounds of acclimatization in SD rats with intact immune systems, we obtained immune-tolerant cell lines and established the orthotopic osteosarcoma model of the distal femur in SD rats. Micro-CT images confirmed tumor-driven osteolysis and the bone destruction process. Moreover, the orthotopic model was also established in New Zealand white rabbits by implanting VX2 tumor fragments into rabbit radii and femurs. We constructed orthotopic osteosarcoma animal models in rats with intact immune systems through muti-rounds in-vivo selection and the rabbit osteosarcoma model.

Microinvasion in hepatocellular carcinoma: predictive factor and application for definition of clinical target volume for radiotherapy.

BACKGROUND: To investigate the correlation between microinvasion and various features of hepatocellular carcinoma (HCC), and to clarify the microinvasion distance from visible HCC lesions to subclinical lesions, so as to provide clinical basis for the expandable boundary of clinical target volume (CTV) from gross tumor volume (GTV) in the radiotherapy of HCC. METHODS: HCC patients underwent hepatectomy of liver cancer in our hospital between July 2019 and November 2021 were enrolled. Data on various features and tumor microinvasion distance were collected. The distribution characteristics of microinvasion distance were analyzed to investigate its potential correlation with various features. Tumor size compared between radiographic and pathologic samples was analyzed to clarify the application of pathologic microinvasion to identify subclinical lesions of radiographic imaging. RESULTS: The average microinvasion distance was 0.6 mm, with 95% patients exhibiting microinvasion distance less than 3.0 mm, and the maximum microinvasion distance was 4.0 mm. A significant correlation was found between microinvasion and liver cirrhosis (P = 0.036), serum albumin level (P = 0.049). Multivariate logistic regression analysis revealed that HCC patients with cirrhosis had a significantly lower risk of microinvasion (OR = 0.09, 95%CI = 0.02 ~ 0.50, P = 0.006). Tumor size was overestimated by 1.6 mm (95%CI=-12.8 ~ 16.0 mm) on radiographic size compared to pathologic size, with a mean %Δsize of 2.96% (95%CI=-0.57%~6.50%). The %Δsize ranged from - 29.03% to 34.78%. CONCLUSIONS: CTV expanding by 5.4 mm from radiographic GTV could include all pathologic microinvasive lesions in the radiotherapy of HCC. Liver cirrhosis was correlated with microinvasion and were independent predictive factor of microinvasion in HCC.

Fe3O4@TiO2 Microspheres: Harnessing O2 Release and ROS Generation for Combination CDT/PDT/PTT/Chemotherapy in Tumours.

In the treatment of various cancers, photodynamic therapy (PDT) has been extensively studied as an effective therapeutic modality. As a potential alternative to conventional chemotherapy, PDT has been limited due to the low Reactive Oxygen Species (ROS) yield of photosensitisers. Herein, a nanoplatform containing mesoporous Fe3O4@TiO2 microspheres was developed for near-infrared (NIR)-light-enhanced chemodynamical therapy (CDT) and PDT. Titanium dioxide (TiO2) has been shown to be a very effective PDT agent; however, the hypoxic tumour microenvironment partly affects its in vivo PDT efficacy. A peroxidase-like enzyme, Fe3O4, catalyses the decomposition of H2O2 in the cytoplasm to produce O2, helping overcome tumour hypoxia and increase ROS production in response to PDT. Moreover, Fe2+ in Fe3O4 could catalyse H2O2 decomposition to produce cytotoxic hydroxyl radicals within tumour cells, which would result in tumour CDT. The photonic hyperthermia of Fe3O4@TiO2 could not only directly damage the tumour but also improve the efficiency of CDT from Fe3O4. Cancer-killing effectiveness has been maximised by successfully loading the chemotherapeutic drug DOX, which can be released efficiently using NIR excitation and slight acidification. Moreover, the nanoplatform has high saturation magnetisation (20 emu/g), making it suitable for magnetic targeting. The in vitro results show that the Fe3O4@TiO2/DOX nanoplatforms exhibited good biocompatibility as well as synergetic effects against tumours in combination with CDT/PDT/PTT/chemotherapy.

MGP+ and IDO1+ tumor-associated macrophages facilitate immunoresistance in breast cancer revealed by single-cell RNA sequencing.

Immunotherapy is widely applied for the treatment of breast cancer, but to which some patients respond poorly or develop resistance. Therefore, the mechanism needs to be further studied. Transcriptomic data of 31 breast cancer patients treated with anti-programmed death receptor 1 (PD-1) was downloaded from the VIB-KULeuven Center for Cancer Biology to analyze the changes in myeloid cells in tumor tissues before and after immunotherapy. And 24 cell populations that may be immune-related were further identified. Representative cell populations were also screened and validated through cellular and animal experiments to evaluate the relevant molecular expression and pathways of tumor-associated macrophages (TAMs) in the tumor microenvironment. The results demonstrated that MGP+ TAMs and IDO1+ TAMs influenced the efficacy of immunotherapy in breast cancer patients. After anti-PD-1 treatment, Increased numbers of MGP+ TAMs and IDO1+ TAMs in breast cancer patients upregulated pro-tumorigenic factors associated with resistance to immunosuppressive therapy. This study provides new biomarkers for immunotherapy to predict therapeutic responses and overcome potential resistance to immunotherapy. It is an important complement to the immunosuppression caused by TAMs after immunotherapy for breast cancer.

Dual Factor-Loaded Artificial Periosteum Accelerates Bone Regeneration.

In the clinic, inactivation of osteosarcoma using microwave ablation would damage the periosteum, resulting in frequent postoperative complications. Therefore, the development of an artificial periosteum is crucial for postoperative healing. In this study, we prepared an artificial periosteum using silk fibroin (SF) loaded with stromal cell-derived factor-1α (SDF-1α) and calcitonin gene-related peptide (CGRP) to accelerate bone remodeling after the microwave ablation of osteosarcoma. The prepared artificial periosteum showed a sustained release of SDF-1α and CGRP after 14 days of immersion. In vitro culture of rat periosteal stem cells (rPDSCs) demonstrated that the artificial periosteum is favorable for cell recruitment, the activity of alkaline phosphatase, and bone-related gene expression. Furthermore, the artificial periosteum improved the tube formation and angiogenesis-related gene expression of human umbilical vein endothelial cells (HUVECs). In an animal study, the periosteum in the femur of a rabbit was inactivated through microwave ablation and then removed. The damaged periosteum was replaced with the as-prepared artificial periosteum and favored bone regeneration. In all, the designed dual-factor-loaded artificial periosteum is a promising strategy to replace the damaged periosteum in the therapy of osteosarcoma for a better bone-rebuilding process.

CD63+ cancer-associated fibroblasts confer CDK4/6 inhibitor resistance to breast cancer cells by exosomal miR-20.

Cyclin-dependent kinase 4 (CDK4) and CDK6 inhibitors (CDK4/6i) have rapidly received Food and Drug Administration (FDA) approval as a new type of therapy for patients with advanced hormone receptor-positive breast cancer. However, with the widespread application of CDK4/6i, drug resistance has become a new challenge for clinical practice and has greatly limited the treatment effect. Here, the whole microenvironment landscape of ER+ breast cancer tumors was revealed through single-cell RNA sequencing, and a specific subset of cancer-associated fibroblasts (CD63+ CAFs) was identified as highly enriched in CDK4/6i resistant tumor tissues. Then, we found that CD63+ CAFs can distinctly promote resistance to CDK4/6i in breast cancer cells and tumor xenografts. In addition, it was discovered that miR-20 is markedly enriched in the CD63+ CAFs-derived exosomes, which are used to communicate with ER+ breast cancer cells, leading to CDK4/6i resistance. Furthermore, exosomal miR-20 could directly target the RB1 mRNA 3'UTR and negatively regulate RB1 expression to decrease CDK4/6i sensitivity in breast cancer cells. Most importantly, we designed and synthesized cRGD-miR-20 sponge nanoparticles and found that they can enhance the therapeutic effect of CDK4/6i in breast cancer. In summary, our findings reveal that CD63+ CAFs can promote CDK4/6i resistance via exosomal miR-20, which induces the downregulation of RB1 in breast cancer cells, and suggest that CD63+ CAFs may be a novel therapeutic target to enhance CDK4/6i sensitivity.

Dosimetry and acute radiation enteritis comparison between prone and supine position in IMRT for gynecological cancers.

PURPOSE: To probe the differences of dosimetry and acute radiation enteritis between prone and supine position in gynecological cancer patients treated with intensity-modulate radiotherapy (IMRT). METHODS: Gynecologic tumor patients who received IMRT from January 2020 to July 2021 were analyzed. 60 patients were enrolled and divided into the supine or prone position group according to different radiotherapy positions, including 34 patients in prone position and 26 patients in supine position. The dose-volume histogram of organs at risk (OARs) and the incidence of acute radiation enteritis were compared between the two groups. Multivariate logistic regression analysis was conducted to show the clinical characteristics and dose volume metrics to the association of acute radiation enteritis. RESULTS: The percentage of volume receiving 5 Gy, 10 Gy, 15 Gy, 20 Gy, 30 Gy, 40 Gy, and 45 Gy doses for the small intestine were 79.0%, 67.4%, 59.6%, 44.3%, 17.0%, 8.9%, and 6.0%, respectively in the prone group, which were lower than those in the supine group (P < 0.05). The mean radiation dose (Dmean ) of the small intestine exposure in prone group was decreased (P < 0.001). Compared with the supine group, the prone group who suffered from acute radiation enteritis were much less. The probability of indigestion, nausea, vomiting, diarrhea, and abdominal pain in the prone position were 35.29%, 29.41%, 17.65%, 38.24%, and 5.88%, respectively. The differences in indigestion, nausea, and diarrhea between the two groups were statistically significant (P = 0.012, P = 0.029, and P = 0.041). Multivariate logistic regression analysis was shown that prone position was found to be protective against indigestion (P = 0.002), nausea (P = 0.013), vomiting (P = 0.035), and abdominal pain (P = 0.021). CONCLUSION: Prone position in IMRT for gynecological cancers could significantly reduce radiation dose to the small bowel and colon, which would decrease the occurrence and severity of acute intestinal side effects possibly.

Molecular Mechanism Underlying the Action of a Celastrol-Loaded Layered Double Hydroxide-Coated Magnesium Alloy in Osteosarcoma Inhibition and Bone Regeneration.

Osteosarcoma (OS) is a malignant bone tumor that threatens human health. Surgical removal of the tumor and followed by implantation with a graft is the golden standard for its clinical treatment. However, avoiding recurrence by enhancing the antitumor properties of the implants and improving osteogenesis around the implants remain a challenge. Here, we developed a layered double hydroxide (LDH)-coated magnesium (Mg) alloy and loaded it with celastrol. The celastrol-loaded Mg alloy exhibited enhanced corrosion resistance and sustained release of celastrol. In vitro cell culture suggested that the modified Mg alloy loaded with an appropriate amount of celastrol significantly inhibited the proliferation and migration of bone tumor cells while having little influence on normal cells. A mechanistic study revealed that the celastrol-loaded Mg alloy upregulated reactive oxygen species (ROS) generation in bone tumor cells, resulting in mitochondrial dysfunction due to reduced membrane potential, thereby inducing bone tumor cell apoptosis. Furthermore, it was found that celastrol-induced autophagy in tumor cells inhibited cell apoptosis in the initial 6 h. After ≥12 h of culture, inhibition of the PI3K-Akt-mTOR signaling pathway was noted, resulting in excessive autophagy in tumor cells, finally causing cell apoptosis. The celatsrol-loaded Mg alloy also exhibited effective antitumor properties in a subcutaneous tumor model. In vitro tartrate-resistant acid phosphatase (TRAP) staining and gene expression results revealed that the modified Mg alloy reduced the viability of osteoclasts, inducing a potential pathway for the increased bone regeneration around the modified Mg alloy seen in vivo. Together, the results of our study show that the celatsrol-loaded Mg alloy might be a promising implant for treating OS.

The screening, identification, design and clinical application of tumor-specific neoantigens for TCR-T cells.

Recent advances in neoantigen research have accelerated the development of tumor immunotherapies, including adoptive cell therapies (ACTs), cancer vaccines and antibody-based therapies, particularly for solid tumors. With the development of next-generation sequencing and bioinformatics technology, the rapid identification and prediction of tumor-specific antigens (TSAs) has become possible. Compared with tumor-associated antigens (TAAs), highly immunogenic TSAs provide new targets for personalized tumor immunotherapy and can be used as prospective indicators for predicting tumor patient survival, prognosis, and immune checkpoint blockade response. Here, the identification and characterization of neoantigens and the clinical application of neoantigen-based TCR-T immunotherapy strategies are summarized, and the current status, inherent challenges, and clinical translational potential of these strategies are discussed.

Characteristics of mesenchymal stem cells and their exosomes derived from giant panda (Ailuropoda melanoleuca) endometrium.

Conservation of genetic resources is an important way to protect endangered species. At present, mesenchymal stem cells (MSCs) have been isolated from the bone marrow and umbilical cords of giant pandas. However, the types and quantities of preserved cell resources were rare and limited, and none of MSCs was derived from female reproductive organs. Here, we first isolated MSCs from the endometrium of giant panda. These cells showed fibroblast morphology and expressed Sox2, Klf4, Thy1, CD73, CD105, CD44, CD49f, and CD105. Endometrium mesenchymal stem cells (eMSCs) of giant panda could induce differentiation into three germ layers in vitro. RNA-seq analysis showed that 833 genes were upregulated and 716 genes were downregulated in eMSCs compared with skin fibroblast cells. The results of GO and the KEGG analysis of differentially expressed genes (DEGs) were mainly focused on transporter activity, signal transducer activity, pathways regulating pluripotency of stem cells, MAPK signaling pathway, and PI3K-Akt signaling pathway. The genes PLCG2, FRK, JAK3, LYN, PIK3CB, JAK2, CBLB, and MET were identified as hub genes by PPI network analysis. In addition, the exosomes of eMSCs were also isolated and identified. The average diameter of exosomes was 74.26 ± 13.75 nm and highly expressed TSG101 and CD9 but did not express CALNEXIN. A total of 277 miRNAs were detected in the exosomes; the highest expression of miRNA was the has-miR-21-5p. A total of 14461 target genes of the whole miRNAs were predicted and proceeded with functional analysis. In conclusion, we successfully isolated and characterized the giant panda eMSCs and their exosomes, and analyzed their functions through bioinformatics techniques. It not only enriched the conservation types of giant panda cell resources and promoted the protection of genetic diversity, but also laid a foundation for the application of eMSCs and exosomes in the disease treatment of giant pandas.

An Exciting Performance of Established and Novel Biomarkers in Diagnosing Periprosthetic Joint Infections: A Single-center Retrospective Cohort Study.

OBJECTIVE: Significant progress has been made in recent years in the diagnosis of periprosthetic joint infections (PJI). However, the lack of a gold standard test for the diagnosis of PJI remains a challenge.The aim of this study was to evaluate the diagnostic values of the albumin/fibrinogen ratio (AFR), the C-reactive protein/albumin ratio (CAR), and the levels of fibrinogen (FIB) and albumin (ALB) in the diagnosis of PJI. METHODS: The medical records of 158 patients who had undergone hip or knee revisions from January 2018 to May 2022 were retrospectively analyzed. Of these patients, 79 were diagnosed with PJI, while 79 were diagnosed with aseptic loosening (AL). PJI was defined using the Musculoskeletal Infection Society criteria. The plasma levels of C-reactive protein (CRP), ALB, and FIB; the erythrocyte sedimentation rate (ESR); and the AFR and CAR in the two groups were recorded and analyzed. The receiver operating characteristic curve was used to calculate the sensitivity and specificity of each indicator; the diagnostic value for each indicator was calculated as the area under the curve (AUC). RESULTS: The ESR, CRP, FIB, and CAR values in the PJI group were significantly higher than those in the AL group, and the ALB and AFR values were significantly lower than those in the AL group (p < 0.001). The AUC values of AFR and fibrinogen were 0.851 and 0.848, respectively, which were slightly higher than those of CRP (0.826) and ESR (0.846). The AUC of CAR was 0.831 which was slightly lower than that of CRP (0.846). ALB had an AUC of 0.727. The optimal threshold, sensitivity, and specificity, respectively, were 10.05, 84.81%, and 82.28% for AFR; 4.03 µg/mL, 77.22%, and 86.08% for FIB; 0.23, 72.15%, and 82.28% for CAR; and 37.30 g/L, 65.82%, and 73.42% for ALB. CONCLUSIONS: AFR, CAR, and FIB are good new auxiliary diagnostic indicators of PJI, while ALB is of fair value for the diagnosis of PJI.

Smart Implant with Bacteria Monitoring and Killing Ability for Orthopedic Applications.

Bacterial infections around implants constitute a significant cause of implant failures. Early recognition of bacterial adhesion is an essential factor in preventing implant infections. Therefore, an implant capable of detecting and disinfecting initial bacterial adhesion is required. This study reports on the development of an intelligent solution for this issue. We developed an implant integrated with a biosensor electrode based on alternating current (AC) impedance technology to monitor the early growth process of Escherichia coli (E. coli) and its elimination. The biosensor electrode was fabricated by coating polypyrrole (PPy) doped with sodium p-toluenesulfonate (TSONa) on titanium (Ti) surfaces. Monitoring the change in resistance using electrochemical impedance spectroscopy (EIS), combined with an equivalent circuit model (ECM), enables the monitoring of the early adhesion of E. coli. The correlation with the classical optical density (OD) monitoring value reached 0.989. Subsequently, the eradication of bacteria on the electrode surface was achieved by applying different voltages to E. coli cultured on the electrode surface, which caused damage to E. coli. Furthermore, in vitro cellular experiments showed that the PPy coating has good biocompatibility and can promote bone differentiation.

Trop2 Promotes Vimentin Expression and Induces Epithelial Stromal Transformation, Invasion and Metastasis of Gastric Cancer Cells by Regulating ß-Catenin.

One of the most critical biological characteristics of gastric cancer (GC) is invasion and metastasis, which is also the main factor of recurrence and drug resistance. Epithelial intermediate transformation is a biological process. Epithelial cells lose the ability to exercise their epithelial characteristics while acquiring parental characteristics. Malignant epithelial cancer cells lose their connectivity and polarity through the EMT process, change cell morphology and enhance their migration ability, so as to gain the ability of invasion and variation. In this paper, we proposed that trop2 can promote vimentin expression by regulating ß - Catenin to induce the transformation and metastasis of gastric cancer cells. In this study, a control group experiment was set up to construct mkn45tr and nci-n87tr resistant cell lines. The results showed that the resistance index (RI) of mkn45tr was 31.33, P < 0.01; the resistance index (RI) of nci-n87tr was 108.23, P < 0.01. The results show that the drug resistance of gastric cancer cells will become stronger with the change of time.

A copper-metal organic framework enhances the photothermal and chemodynamic properties of polydopamine for melanoma therapy.

The combination of photothermal treatment and chemodynamic therapy has attracted extensive attention for improving therapeutic effects and compensating the insufficiency of monotherapy. In this work, a copper-metal organic framework (Cu-BTC) was used to augment the photothermal effect of polydopamine (PDA) and endow it with a chemodynamic ability by constructing a Cu-BTC@PDA nanocomposite. Density functional theory calculations revealed that the plasmonic vibrations formed by the d-d transition of Cu at the Fermi level in Cu-BTC@PDA could enhance the photothermal performance of PDA. In addition, more Cu2+ released from Cu-BTC@PDA in the acidic microenvironment of the tumor was then reduced to Cu+ by glutathione (GSH) and further catalyzed H2O2 to generate more toxic hydroxyl radical (•OH), which synergized with photothermal treatment for melanoma therapy. Furthermore, Cu-BTC@PDA could quickly and effectively kill bacteria under the action of PTT, and the sustained release of Cu ions could contribute to the long-term and stable bacteriostatic ability of the material. This sustained release of Cu ions could also promote the cell migration and angiogenesis, and upregulate the expression of COL-, TGF-, and VEGF-related genes to accelerate wound healing. This multifunctional nanomaterial has potential application in the treatment of melanoma and repair of wounds. STATEMENT OF SIGNIFICANCE: We constructed a multifunctional nanoplatform (Cu-BTC@PDA) by two steps. This nanoplatform can not only perform cascade catalysis in the tumor microenvironment to generate more toxic hydroxyl radical (•OH), but also synergize with photothermal treatment for melanoma therapy. Additionally, Cu-BTC@PDA possesses enhanced photothermal performance through the plasmonic vibrations formed by the d-d transition of Cu at the Fermi level in Cu-BTC@PDA, which is revealed by DFT calculations. And Cu-BTC@PDA shows good antitumor, antibacterial, and wound healing properties in vivo and in vitro. Such a multifunctional nanomaterial has potential application in the treatment of melanoma and repair of wounds.

Microenvironment-responsive electrocution of tumor and bacteria by implants modified with degenerate semiconductor film.

Implantable biomaterials are widely used in the curative resection and palliative treatment of various types of cancers. However, cancer residue around the implants usually leads to treatment failure with cancer reoccurrence. Postoperation chemotherapy and radiation therapy are widely applied to clear the residual cancer cells but induce serious side effects. It is urgent to develop advanced therapy to minimize systemic toxicity while maintaining efficient cancer-killing ability. Herein, we report a degenerate layered double hydroxide (LDH) film modified implant, which realizes microenvironment-responsive electrotherapy. The film can gradually transform into a nondegenerate state and release holes. When in contact with tumor cells or bacteria, the film quickly transforms into a nondegenerate state and releases holes at a high rate, rendering the "electrocution" of tumor cells and bacteria. However, when placed in normal tissue, the hole release rate of the film is much slower, thus, causing little harm to normal cells. Therefore, the constructed film can intelligently identify and meet the physiological requirements promptly. In addition, the transformation between degenerate and nondegenerate states of LDH films can be cycled by electrical charging, so their selective and dynamic physiological functions can be artificially adjusted according to demand.

CENP-F-dependent DRP1 function regulates APC/C activity during oocyte meiosis I.

Chromosome segregation is initiated by cohesin degradation, which is driven by anaphase-promoting complex/cyclosome (APC/C). Chromosome cohesin is removed by activated separase, with the degradation of securin and cyclinB1. Dynamin-related protein 1 (DRP1), a component of the mitochondrial fission machinery, is related to cyclin dynamics in mitosis progression. Here, we show that DRP1 is recruited to the kinetochore by centromeric Centromere protein F (CENP-F) after nuclear envelope breakdown in mouse oocytes. Loss of DRP1 during prometaphase leads to premature cohesin degradation and chromosome segregation. Importantly, acute DRP1 depletion activates separase by initiating cyclinB1 and securin degradation during the metaphase-to-anaphase transition. Finally, we demonstrate that DRP1 is bound to APC2 to restrain the E3 ligase activity of APC/C. In conclusion, DRP1 is a CENP-F-dependent atypical spindle assembly checkpoint (SAC) protein that modulates metaphase-to-anaphase transition by controlling APC/C activity during meiosis I in oocytes.

Effect of linear accelerator carbon fiber couch on radiotherapy dose.

This study aimed to explore the effect of carbon fiber couch on radiotherapy dose attenuation and gamma pass rate in intensity-modulated radiotherapy (IMRT) plans. A phantom inserted with an ionization chamber was placed at different positions of the couch, and the dose was measured by the chamber. Under the same positioning, the phantom dose was calculated using the real and virtual couch images, and the difference in the planned dose of radiotherapy was compared. Ten clinical IMRT plans were selected as dose verification data, and the gamma pass rates were compared between couch addition and non-addition conditions. When the radiation field was near 110° and 250°, the measured value attenuation coefficient of the ionization chamber at the joint of the couch was up to 34%; the attenuation coefficient of the treatment couch from the actual couch image calculated using the treatment planning system (TPS) was up to 33%; the attenuation coefficient of the virtual couch calculated using the TPS was up to 4.0%. The gamma pass rate of the dose verification near gantry angles 110° and 250° was low, and that of the joint could be lower than 85% under the condition of 3%/3 mm. The gamma pass rates of the radiation field passing through the couch were all affected. The dose was affected by the radiation field passing through the couch, with the largest effect when passing through the joint part of the treatment couch, followed by that of the main couch plate and extension plate. When the irradiation field passed through the joint and near 110° and 250° of the main couch, the dose difference was large, making it unsuitable for treatment.

Metallic Nanoparticle-Doped Oxide Semiconductor Film for Bone Tumor Suppression and Bone Regeneration.

Bone implants with the photothermal effect are promising for the treatment of bone tumor defects. Noble metal-based photothermal nanoagents are widely studied for their stable photothermal effect, but they are expensive and difficult to directly grow on implant surfaces. In contrast, non-noble metal photothermal nanoagents are economical but unstable. Herein, to develop a stable and economical photothermal film on bone implants, a Ni nanoparticle-doped oxide semiconductor film was grown in situ on Nitinol via the reduction of Ni-Ti-layered double hydroxides. Ni nanoparticles remained stable in the NiTiO3 structure even when immersed in fluid for 1 month, and thus, the film presented a reliable photothermal effect under near-infrared light irradiation. The film also showed excellent in vitro and in vivo antitumor performance. Moreover, the nanostructure on the film allowed bone differentiation of mouse embryo cells (C3H10T1/2), and the released Ni ions supported the angiogenesis behavior of human vein endothelial cells. Bone implantation experiments further showed the enhancement of osteointegration of the modified Nitinol implant in vivo. This novel multifunctional Nitinol bone implant design offers a promising strategy for the therapy of bone tumor-related defects.

Comparison of transcriptome profiles of mesenchymal stem cells derived from umbilical cord and bone marrow of giant panda (Ailuropoda melanoleuca).

Mesenchymal stem cells (MSCs) have pluripotent differentiation ability and play an important role in human clinical cell therapy. While, the research on MSCs in endangered wild animals is extremely rare. In our previous studies, the bone marrow mesenchymal stem cells (bmMSCs) and umbilical cord mesenchymal stem cells (ucMSCs) of giant panda (Ailuropoda melanoleuca) were successfully isolated. We aimed to characterize the differences in gene expression profiles between these two types of MSCs using RNA sequencing (RNA-Seq) and to determine which potential pathways are involved in functional regulation. In total, 1079 significantly differentially expressed genes (DEGs) were identified, of which 478 genes were upregulated and 601 genes were downregulated. The significantly enriched Gene Ontology (GO) terms mainly contained cell adhesion, biological adhesion, intracellular signal transduction, molecular function regulator, Ras protein signal transduction, small GTPase mediated signal transduction, and regulation of Rho protein signal transduction. The most enrichment pathways of DEGs enriched in Kyoto Encyclopedia of Genes Genomes (KEGG) were PI3K-AKT signaling pathway, Rap1 signaling pathway, MAPK signaling pathway, Hippo signaling pathway, Wnt signaling pathway, cGMP-PKG signaling pathway and Signaling pathways regulating pluripotency of stem cells. In addition, quantitative real time polymerase chain reaction (qRT-PCR) showed that the AKT3, CDK2, MAPK3, mTOR, PI3K and PTK2 genes associated with PI3K-AKT pathway were highly expressed (P < 0.01), and Caspase-3 was low expressed (P < 0.05) in ucMSCs group when compared with bmMSCs. After treatment with the PI3K inhibitor LY294002, genes AKT3, CDK2, MAPK3, mTOR, and PTK2 were significantly decreased in ucMSCs (P < 0.01), and Caspase-3 was significantly up regulated (P < 0.001). In conclusion, we for the first time compared and analyzed the transcriptome profiles of giant panda ucMSCs and bmMSCs, and found the PI3K-AKT pathway was highly activated and might be a key signaling pathway in the ucMSCs regulation. This study will be beneficial for the research on MSCs proliferation regulation and differentiation of giant pandas in the future, and lay the foundation for MSCs application and clinical therapy for endangered wild animals.