Clinical application of ERCP concurrent laparoscopic cholecystectomy in the treatment of cholecystolithiasis complicated with extrahepatic bile duct stones.

Objective: To compare the clinical efficacy of endoscopic retrograde cholangiopancreatography (ERCP) combined with laparoscopic cholecystectomy (LC) and laparoscopic common bile duct exploration and lithotomy (LCBDE) in the treatment of cholecystolithiasis combined with bile duct stones. Methods: From September 2018 to January 2022, 195 patients with cholecystolithiasis complicated with extrahepatic bile duct stones from Department of Department of General Surgery, Shanghai Jiading Central Hospital met the inclusion criteria, including 60 cases in the LC group and 86 cases in the LCBDE group. The general condition, operation success rate, complications and residual stone rate of the two groups were retrospectively analyzed. Results: In the simultaneous operation group, 58 patients successfully performed ERCP, and the indwelling rate of the abdominal drainage tube (41.7 % vs. 95.3 %) was significantly better than that in the LCBDE group. There was no significant difference in the conversion rate to open surgery, operation time, and intraoperative blood loss between the two groups. In the simultaneous surgery group, 4 patients (6.7 %) developed pancreatitis after ERCP, which was cured by conservative treatment. The pain score at 6 h after operation was significantly lower than that in the LCBDE group (3.9 ± 1.6 vs 6.5 ± 2.4). There were no significant differences in biliary leakage (1.7 % vs. 4.7 %), postoperative cholangitis (5.0 % vs. 5.8 %), incision infection (3.3 % vs. 3.5 %), and bile duct stone residue rate (5.0 % vs 3.5 %) between the two groups. There was no severe pancreatitis, second operation or death. The duration of hospital stay was shortened in the concurrent operation group (5.1 ± 2.3d vs 7.9 ± 3.7d), and the operation cost was significantly higher than that in the LCBDE group (48839.9 ± 8549.5 vs 34635.9 ± 5893.7 yuan). Conclusion: ERCP combined with LC and LCBDE are both safe and effective methods for the treatment of cholecystolithiasis combined with extrahepatic bile duct stones. The simultaneous operation group has certain advantages in patient comfort and rapid rehabilitation, which can be popularized in qualified units.

The quantity, function and anti-tumor effect of Mucosal associated invariant T cells in patients with bladder cancer.

BACKGROUND: Bladder cancer (BC), a prevalent malignancy in the urinary system, often poses challenges for effective treatment. Immunotherapy, harnessing the immune system, has exhibited promise in early-stage clinical trials. Mucosal associated invariant T (MAIT) cells, a subset of immune cells implicated in various diseases, including certain cancer, have yet to be explored in BC patients. We aimed to investigate the quantity, function, and anti-tumor effects of MAIT cells in BC patients. METHODS: A total of 75 newly diagnosed BC patients and 183 healthy volunteers were included. Blood samples were collected and analyzed to evaluate the quantity and function of MAIT cells. Surgical resection provided BC tissues for further analysis, and the clinical features of BC tumors were collected and their relationship with MAIT cells was explored. RESULTS: MAIT cells were identified in both healthy individuals and BC patients. The proportion of MAIT cells in the peripheral blood of BC patients did not significantly differ from that of healthy controls. However, the study revealed a correlation between the proportion of IFN-γ producing MAIT cells and tumor number and invasion in BC patients. Furthermore, MAIT cells exhibited cytotoxic effects on BC cells in vitro and in vivo. CONCLUSIONS: This study sheds light on the role of MAIT cells in BC. While the quantity of MAIT cells showed no significant change in BC patients, their functional attributes and association with tumor characteristics suggest their potential as an immunotherapy target in BC treatment.

Engineering of 4-hydroxyphenylacetate 3-hydroxylase derived from Pseudomonas aeruginosa for the ortho-hydroxylation of ferulic acid.

Polyphenolic compounds have natural antioxidant properties, and their antioxidant activity is usually related to the number and position of hydroxyls. Here, we successfully applied the engineered 4-hydroxyphenylacetate 3-hydroxylases (4HPA3Hs) derived from Pseudomonas aeruginosa to catalyze ferulic acid (FA) synthesis of ortho-hydroxyferulic acid (5-hydroxyferulic acid, 5-OHFA). Through optimization of co-expression, the oxygenase component (PaHpaB) and the reductase component (PaHpaC) in E. coli, and optimization of whole-cell catalytic conditions, the engineered strain BC catalyzed ortho-hydroxylation of 2 g/L of FA with a yield of 75 % from 39 %. Through tunnel engineering of PaHpaB, the obtained mutants F301A and Q376A almost completely transformed 2 g/L of FA. Further, a multiple mutant L214A/F301A/Q376A converted 4 g/L FA into 5-OHFA within 12 h, and the yield reached 99.9 %, which was approximately 2.39-fold of the wild type. The kcat/Km value of L214A/F301A/Q376A was about 307 times greater than that of the wide type. Analysis of three-dimensional structural models showed that L214, F301, and Q376 mutated into Ala, which greatly shortened the side chain and broadened the tunnel size, thereby significantly improving the catalytic efficiency of L214A/F301A/Q376A. This biosynthesis of 5-OHFA is simple, efficient, and green, suggesting that it is useful for efficient biosynthesis of polyphenolic compounds.

A transcription factor complex in Dictyostelium enables adaptive changes in macropinocytosis during the growth-to-development transition.

Macropinocytosis, an evolutionarily conserved endocytic pathway, mediates nonselective bulk uptake of extracellular fluid. It is the primary route for axenic Dictyostelium cells to obtain nutrients and has also emerged as a nutrient-scavenging pathway for mammalian cells. How cells adjust macropinocytic activity in various physiological or developmental contexts remains to be elucidated. We discovered that, in Dictyostelium cells, the transcription factors Hbx5 and MybG form a functional complex in the nucleus to maintain macropinocytic activity during the growth stage. In contrast, during starvation-induced multicellular development, the transcription factor complex undergoes nucleocytoplasmic shuttling in response to oscillatory cyclic adenosine 3',5'-monophosphate (cAMP) signals, which leads to increased cytoplasmic retention of the complex and progressive downregulation of macropinocytosis. Therefore, by coupling macropinocytosis-related gene expression to the cAMP oscillation system, which facilitates long-range cell-cell communication, the dynamic translocation of the Hbx5-MybG complex orchestrates a population-level adjustment of macropinocytic activity to adapt to changing environmental conditions.

Glutathione degradable manganese-doped polydopamine nanoparticles for photothermal therapy and cGAS-STING activated immunotherapy of lung tumor.

Photothermal therapy (PTT), which utilizes nanomaterials to harvest laser energy and convert it into heat to ablate tumor cells, has been rapidly developed for lung tumor treatment, but most of the PTT-related nanomaterials are not degradable, and the immune response associated with PTT is unclear, which leads to unsatisfactory results of the actual PTT. Herein, we rationally designed and prepared a manganese ion-doped polydopamine nanomaterial (MnPDA) for immune-activated PTT with high efficiency. Firstly, MnPDA exhibited 57.2% photothermal conversion efficiency to accomplish high-efficiency PTT, and secondly, MnPDA can be stimulated by glutathione (GSH) to the release of Mn2+, and it can produce ·OH in a Fenton-like reaction with the overexpressed H2O2 and stimulate the cyclic GMP-AMP synthase-stimulator of interferon genes (cGAS-STING) pathway. These two synergistically can effectively remove lung tumor cells that have not been ablated by PTT, resulting in an 86.7% tumor suppression rate under laser irradiation of MnPDA in vivo, and further significantly activated the downstream immune response, as evidenced by an increased ratio of cytotoxic T cells to immunosuppressive Treg cells. Conclusively, the GSH degradable MnPDA nanoparticles can be used for photothermal therapy and cGAS-STING-activated immunotherapy of lung tumors, which provides a new idea and strategy for the future treatment of lung tumors.

4-Hydroxyphenylacetate 3-Hydroxylase (4HPA3H): A Vigorous Monooxygenase for Versatile O-Hydroxylation Applications in the Biosynthesis of Phenolic Derivatives.

4-Hydroxyphenylacetate 3-hydroxylase (4HPA3H) is a long-known class of two-component flavin-dependent monooxygenases from bacteria, including an oxygenase component (EC 1.14.14.9) and a reductase component (EC 1.5.1.36), with the latter being accountable for delivering the cofactor (reduced flavin) essential for o-hydroxylation. 4HPA3H has a broad substrate spectrum involved in key biological processes, including cellular catabolism, detoxification, and the biosynthesis of bioactive molecules. Additionally, it specifically hydroxylates the o-position of the C4 position of the benzene ring in phenolic compounds, generating high-value polyhydroxyphenols. As a non-P450 o-hydroxylase, 4HPA3H offers a viable alternative for the de novo synthesis of valuable natural products. The enzyme holds the potential to replace plant-derived P450s in the o-hydroxylation of plant polyphenols, addressing the current significant challenge in engineering specific microbial strains with P450s. This review summarizes the source distribution, structural properties, and mechanism of 4HPA3Hs and their application in the biosynthesis of natural products in recent years. The potential industrial applications and prospects of 4HPA3H biocatalysts are also presented.

Prediction of immune infiltration and prognosis for patients with cholangiocarcinoma based on a cuproptosis-related lncRNA signature.

Objective: Cholangiocarcinoma (CHOL) is a malignant disease that affects the digestive tract, and it is characterized by a poor prognosis. This research sought to explore the involvement of cuproptosis-related lncRNAs (CRLs) in the prognostic prediction and immune infiltration of cholangiocarcinoma. Methods: The expression profiles and clinical data of CHOL patients were acquired from The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) databases, and CRLs were defined via co-expression analysis. Two molecular clusters distinguished by cuproptosis-related genes (CRGs) were produced. Then a risk signature consisted by four CRLs was formed, and all samples were separated into low- and high-risk groups using a risk score. Kaplan-Meier survival analysis, principal component analysis, differentially expressed analysis, immune cell infiltration analysis, and sensitivities analysis of chemotherapy drugs were conducted between the two groups. Simultaneously, the expression values of four lncRNAs confirmed by real-time PCR in our own 20 CHOL samples were brought into the risk model. Results: The CHOL samples could be differentiated into two molecular clusters, which displayed contrasting survival times. Additionally, patients with higher risk scores had significantly worse prognosis compared to those in the low-risk group. Furthermore, both immune infiltration and enrichment analysis revealed significant discrepancies in the tumor immune microenvironment (TIME) between different risk groups. Moreover, the predictive power and the correlation with CA19-9 and CEA of risk signature were validated in our own samples. Conclusion: We developed a risk signature which could serve as an independent prognostic factor and offer a promising prediction for not only prognosis but also TIME in CHOL patients.

Targeting ONECUT3 blocks glycolytic metabolism and potentiates anti-PD-1 therapy in pancreatic cancer.

BACKGROUND: Reprogramming glucose metabolism, also known as the Warburg effect (aerobic glycolysis), is a hallmark of cancers. Increased tumor glycolysis not only favors rapid cancer cell proliferation but reprograms the immune microenvironment to enable tumor progression. The transcriptional factor ONECUT3 plays key roles in the development of the liver and pancreas, however, limited is known about its oncogenic roles, particularly metabolic reprogramming. METHODS: Immunohistochemistry and Western blotting are applied to determine the expression pattern of ONECUT3 and its clinical relevance in pancreatic ductal adenocarcinoma (PDAC). Knockdown and overexpression strategies are employed to determine the in vitro and in vivo functions of ONECUT3. Chromatin immunoprecipitation, luciferase reporter assay, and gene set enrichment analysis are used to decipher the molecular mechanisms. RESULTS: The glycolytic metabolism is inversely associated with T-cell infiltration in PDAC. ONECUT3 is identified as a key regulator for PDAC glycolysis and CD8+ T-cell infiltration. Genetic silencing of ONECUT3 inhibits cell proliferation, promotes cell apoptosis, and reduces glycolytic metabolism as evidenced by glucose uptake, lactate production, and extracellular acidification rate. Opposite effects of ONECUT3 are observed in overexpression studies. ONECUT3 enhances aerobic glycolysis via transcriptional regulation of PDK1. Targeting ONECUT3 effectively suppresses tumor growth, increases CD8+ T-cell infiltration, and potentiates anti-PD-1 therapy in PDAC. Pharmacological inhibition of PDK1 also shows a synergistic effect with anti-PD-1 therapy. In clinical setting, ONECUT3 is closely associated with PDK1 expression and T-cell infiltration in PDAC and acts as an independent prognostic factor. CONCLUSIONS: Our study reveals a previous unprecedented regulatory role of ONECUT3 in PDAC glycolysis and provides in vivo evidence that increased glycolysis is linked to an immunosuppressive microenvironment. Moreover, targeting ONECUT3-PDK1 axis may serve as a promising therapeutic approach for the treatment of PDAC.

Lymph node ratio is a prognostic indicator for locally advanced esophageal squamous cell carcinoma after neoadjuvant immunochemotherapy.

The lymph node ratio (LNR) is regarded as a prognostic indicator in esophageal cancer (EC), but its applicability to neoadjuvant immunochemotherapy (NICT) in esophageal squamous cell carcinoma (ESCC) remains unexplored. This retrospective study, conducted between 2019 and 2021, analyzed ESCC patients who underwent radical esophagectomy following NICT. Patients were divided into two groups based on their LNR values according to the X-tile software: Low-LNR group (LNR 0-10%) and High-LNR group (LNR 10-100%). The association between LNR and clinical outcomes in ESCC after NICT were analyzed. A total of 212 ESCC patients who underwent surgery after NICT were included in this study, among which, 169 (79.7%) and 43 (20.3%) cases were allocated to the Low- and High-LNR groups, respectively. Pathologic complete response (PCR) was observed in 28.3% (60/212) of the overall cohort. Patients in the Low-LNR group demonstrated a significantly improved 3-year overall survival (OS) (81.7% vs 55.3%; P < 0.001) and disease-free survival (DFS) (79.9% vs 37.4%; P < 0.001). These findings were consistent among those with non-PCR (3-year DFS was 73.7% vs 37.4%; P < 0.001, and the 3-year OS was 78.9% vs 55.3%; P < 0.001, respectively). High LNR was associated with a 4.013-fold increased risk of relapse and a 7.026-fold elevated risk of death. Compared to the post-neoadjuvant therapy pathologic lymph nodes staging (ypN), LNR exhibited similar prognostic capabilities for DFS and OS. To the best of our knowledge, this study is the first to investigate the prognostic value of LNR in ESCC after NICT, suggesting that LNR may serve as a viable alternative to the ypN stage for prognostication in ESCC patients treated with NICT.

Interfacial Organization and Forces Arising from Epithelial-Cancerous Monolayer Interactions.

The interfacial interactions between epithelia and cancer cells have profound relevance for tumor development and metastasis. Through monolayer confrontation of MCF10A (nontumorigenic human breast epithelial cells) and MDA-MB-231 (human epithelial breast cancer cells) cells, we investigate the epithelial-cancerous interfacial interactions at the tissue level. We show that the monolayer interaction leads to competitive interfacial morphodynamics and drives an intricate spatial organization of MCF10A cells into multicellular finger-like structures, which further branch into multiple subfinger-like structures. These hierarchical interfacial structures penetrate the cancer monolayer and can spontaneously segregate or even envelop cancer cell clusters, consistent with our theoretical prediction. By tracking the substrate displacements via embedded fluorescent nanobeads and implementing nanomechanical modeling that combines atomic force microscopy and finite element simulations, we computed mechanical force patterns, including traction forces and monolayer stresses, caused by the monolayer interaction. It is found that the heterogeneous mechanical forces accumulated in the monolayers are able to squeeze cancer cells, leading to three-dimensional interfacial bulges or cell extrusion, initiating the p53 apoptosis signaling pathways of cancer cells. We reveal that intercellular E-cadherin and P-cadherin of epithelial cells differentially regulate the interfacial organization including migration speed, directionality, spatial correlation, F-actin alignment, and subcellular protrusions of MCF10A cells; whereas E-cadherin governs interfacial geometry that is relevant to force localization and cancer cell extrusion, P-cadherin maintains interfacial integrity that enables long-range force transmission. Our findings suggest that the collaborative molecular and mechanical behaviors are crucial for preventing epithelial tissues from undergoing tumor invasion.

Gasdermin D permeabilization of mitochondrial inner and outer membranes accelerates and enhances pyroptosis.

Gasdermin D (GSDMD)-activated inflammatory cell death (pyroptosis) causes mitochondrial damage, but its underlying mechanism and functional consequences are largely unknown. Here, we show that the N-terminal pore-forming GSDMD fragment (GSDMD-NT) rapidly damaged both inner and outer mitochondrial membranes (OMMs) leading to reduced mitochondrial numbers, mitophagy, ROS, loss of transmembrane potential, attenuated oxidative phosphorylation (OXPHOS), and release of mitochondrial proteins and DNA from the matrix and intermembrane space. Mitochondrial damage occurred as soon as GSDMD was cleaved prior to plasma membrane damage. Mitochondrial damage was independent of the B-cell lymphoma 2 family and depended on GSDMD-NT binding to cardiolipin. Canonical and noncanonical inflammasome activation of mitochondrial damage, pyroptosis, and inflammatory cytokine release were suppressed by genetic ablation of cardiolipin synthase (Crls1) or the scramblase (Plscr3) that transfers cardiolipin to the OMM. Phospholipid scramblase-3 (PLSCR3) deficiency in a tumor compromised pyroptosis-triggered anti-tumor immunity. Thus, mitochondrial damage plays a critical role in pyroptosis.

The Fatty Liver Index, the Strongest Risk Factor for Low Testosterone Level.

INTRODUCTION: The study aimed to determine if hepatic steatosis assessed by fatty liver index (FLI) was an independent risk factor for male low testosterone level and whether the FLI was the strongest risk factor for low testosterone level in two different age groups. METHODS: Two cross-sectional studies were performed. A total of 3,443 male participants (aged 46-75) were recruited into study A (part of lONgitudinal study (REACTION)). Then a total of 267 male participants (aged 25-45) were recruited into study B. Serum total testosterone (TT) and sex hormone-binding globulin (SHBG) levels, indicators for assessing hepatic steatosis were measured. The Pearson correlation and regression analysis were performed to investigate the risk factors for low testosterone level. RESULTS: The FLI had the strongest negative correlation with serum testosterone in the study A (r = -0.436) and B (r = -0.542). Compared with patients with a FLI lower than 30, the risk for low testosterone level increased by 3.48-fold in subjects with a FLI higher than 60 adjusted for potential risk factors in study A. In study B, the odds ratio of low testosterone level in patients with potential hepatic steatosis was 4.26 (1.57-11.60) after adjusted for age and homeostasis model assessment of insulin resistance (HOMA-IR) and 0.59 (0.14-2.60) after adjusted for age, HOMA-IR, waist circumference, body mass index, and SHBG. CONCLUSIONS: FLI was the strongest risk factor for male low testosterone level independent of insulin resistance in male populations of different ages; however, the association can be modulated by SHBG levels in the young. SIGNIFICANCE STATEMENT: In the study, FLI was the strongest negative risk factor for low testosterone level in the Chinese adult male population. The results suggested that hepatic steatosis assessed by the FLI was the main risk factor for male low testosterone level, independent of age, insulin resistance, smoking, and drinking status; however, the association of FLI and TT levels can be modulated by SHBG levels. Taken together these findings indicate that clinical physicians should pay more attention to the FLI index and hepatic steatosis, so that they can take advantage of them for assessing the risk of developing of low testosterone level in the male population.

Substrate nesting guides cyst morphogenesis of human pluripotent stem cells without 3D extracellular matrix overlay.

Understanding the principles underlying the self-organization of stem cells into tissues is fundamental for deciphering human embryo development. Here, we report that, without three-dimensional (3D) extracellular matrix (ECM) overlay, human pluripotent stem cells (hPSCs) cultured on two-dimensional soft elastic substrates can self-organize into 3D cysts resembling the human epiblast sac in a stiffness-dependent manner. Our theoretical modeling predicts that this cyst organization is facilitated and guided by the spontaneous nesting of the soft substrate, which results from the adhesion-dependent mechanical interaction between cells and substrate. Such substrate nesting is sufficient for the 3D assembly and polarization of hPSCs required for cyst organization, even without 3D ECM overlay. Furthermore, we identify that the reversible substrate nesting and cyst morphogenesis also require appropriate activation of ROCK-Myosin II pathway. This indicates a unique set of tissue morphomechanical signaling mechanisms that clearly differ from the canonical cystogenic mechanism previously reported in 3D ECM. Our findings highlight an unanticipated synergy between mechanical microenvironment and mechanotransduction in controlling tissue morphogenesis and suggest a mechanics-based strategy for generation of hPSCs-derived models for early human embryogenesis. STATEMENT OF SIGNIFICANCE: Soft substrates can induce the self-organization of human pluripotent stem cells (hPSCs) into cysts without three-dimensional (3D) extracellular matrix (ECM) overlay. However, the underlying mechanisms by which soft substrate guides cystogenesis are largely unknown. This study shows that substrate nesting, resulting from cell-substrate interaction, plays an important role in cyst organization, including 3D assembly and apical-basal polarization. Additionally, actomyosin contractility mediated by the ROCK-Myosin II pathway also contributes to the substrate deformation and cyst morphology. These findings demonstrate the interplay between the mechanical microenvironment and cells in tissue morphogenesis, suggesting a mechanics-based strategy in building hPSC-derived models for early human embryo development.

Disulfiram blocks inflammatory TLR4 signaling by targeting MD-2.

Toll-like receptor 4 (TLR4) sensing of lipopolysaccharide (LPS), the most potent pathogen-associated molecular pattern of gram-negative bacteria, activates NF-κB and Irf3, which induces inflammatory cytokines and interferons that trigger an intense inflammatory response, which is critical for host defense but can also cause serious inflammatory pathology, including sepsis. Although TLR4 inhibition is an attractive therapeutic approach for suppressing overexuberant inflammatory signaling, previously identified TLR4 antagonists have not shown any clinical benefit. Here, we identify disulfiram (DSF), an FDA-approved drug for alcoholism, as a specific inhibitor of TLR4-mediated inflammatory signaling. TLR4 cell surface expression, LPS sensing, dimerization and signaling depend on TLR4 binding to MD-2. DSF and other cysteine-reactive drugs, previously shown to block LPS-triggered inflammatory cell death (pyroptosis), inhibit TLR4 signaling by covalently modifying Cys133 of MD-2, a key conserved residue that mediates TLR4 sensing and signaling. DSF blocks LPS-triggered inflammatory cytokine, chemokine, and interferon production by macrophages in vitro. In the aggressive N-methyl-4-phenyl-1,2,3,6-tetrahydropyridine mouse model of Parkinson's disease (PD) in which TLR4 plays an important role, DSF markedly suppresses neuroinflammation and dopaminergic neuron loss, and restores motor function. Our findings identify a role for DSF in curbing TLR4-mediated inflammation and suggest that DSF and other drugs that target MD-2 might be useful for treating PD and other diseases in which inflammation contributes importantly to pathogenesis.

Exploitation and Verification of a Stroma- and Metastasis-Associated Risk Prognostic Signature in Pancreatic Adenocarcinoma.

Pancreatic adenocarcinoma (PAAD), one of the most malignant tumors, not only has abundant mesenchymal components, but is also characterized by an extremely high metastatic risk. The purpose of this study was to construct a model of stroma- and metastasis-associated prognostic signature, aiming to benefit the existing clinical staging system and predict the prognosis of patients. First, stroma-associated genes were screened from the TCGA database with the ESTIMATE algorithm. Subsequently, transcriptomic data from clinical tissues in the RenJi cohort were screened for metastasis-associated genes. Integrating the two sets of genes, we constructed a risk prognostic signature by Cox and LASSO regression analysis. We then obtained a risk score by a quantitative formula and divided all samples into high- and low-risk groups based on the scores. The results demonstrated that patients with high-risk scores have a worse prognosis than those with low-risk scores, both in the TCGA database and in the RenJi cohort. In addition, tumor mutation burden, chemotherapeutic drug sensitivity and immune infiltration analysis also exhibited significant differences between the two groups. In exploring the potential mechanisms of how stromal components affect tumor metastasis, we simulated different matrix stiffness in vitro to explore its effect on EMT key genes in PAAD cells. We found that cancer cells stimulated by high matrix stiffness may trigger EMT and promote PAAD metastasis.

Circ_0051079 functions as an oncogenic regulator in osteosarcoma by leading to MAFB expression upregulation by competitively interacting with miR-1286.

BACKGROUND: Circular RNAs are involved in various cellular processes of bone diseases by acting as miRNA sponges to regulate gene expression levels, including osteosarcoma (OS). This research concentrated on the molecular mechanism of circ_0051079 in OS progression. METHODS: Reverse transcription-quantitative polymerase chain reaction assay was used for expression detection of circ_0051079, microRNA-1286 (miR-1286), and musculoaponeurotic fibrosarcoma oncogene homolog B (MAFB). Cell Counting Kit-8 assay and Edu assay were used for cell proliferation analysis. Cell apoptosis was evaluated using flow cytometry. Western blot was performed to measure protein levels. Migration and invasion were assessed via transwell assay. Interaction of circ_0051079/miR-1286 or miR-1286/MAFB was explored through a dual-luciferase reporter assay. In vivo research was carried out via tumor xenograft assay and immunohistochemistry staining. RESULTS: Circ_0051079 expression was upregulated in OS. Downregulation of circ_0051079 reduced OS cell proliferation, migration, invasion, and accelerated apoptosis. Circ_0051079 interacted with miR-1286, and the tumor-inhibitory function of si-circ_0051079 was abolished by miR-1286 inhibition in OS cells. MAFB served as a target for miR-1286. OS cell progression was suppressed by miR-1286 overexpression via downregulating MAFB. Circ_0051079/miR-1286 resulted in expression change of MAFB in OS cells. Silencing circ_0051079 inhibited tumor growth in vivo via regulating the miR-1286/MAFB axis. CONCLUSION: The collective results elucidated that circ_0051079 contributed to OS progression via miR-1286-mediated upregulation of MAFB, confirming the interaction of circ_0051079/miR-1286/MAFB axis in OS.

Unified multiscale theory of cellular mechanical adaptations to substrate stiffness.

Rigidity of the extracellular matrix markedly regulates many cellular processes. However, how cells detect and respond to matrix rigidity remains incompletely understood. Here, we propose a unified two-dimensional multiscale framework accounting for the chemomechanical feedback to explore the interrelated cellular mechanosensing, polarization, and migration, which constitute the dynamic cascade in cellular response to matrix stiffness but are often modeled separately in previous theories. By combining integrin dynamics and intracellular force transduction, we show that substrate stiffness can act as a switch to activate or deactivate cell polarization. Our theory quantitatively reproduces rich stiffness-dependent cellular dynamics, including spreading, polarity selection, migration pattern, durotaxis, and even negative durotaxis, reported in a wide spectrum of cell types, and reconciles some inconsistent experimental observations. We find that a specific bipolarized mode can determine the optimal substrate stiffness, which enables the fastest cell migration rather than the largest traction forces that cells apply on the substrate. We identify that such a mechanical adaptation stems from the force balance across the whole cell. These findings could yield universal insights into various stiffness-mediated cellular processes within the context of tissue morphogenesis, wound healing, and cancer invasion.