Phosphorylation of STAT3 at Tyr705 contributes to TFEB-mediated autophagy-lysosomal pathway dysfunction and leads to ischemic injury in rats.

We previously reported that permanent ischemia induces marked dysfunction of the autophagy-lysosomal pathway (ALP) in rats, which is possibly mediated by the transcription factor EB (TFEB). However, it is still unclear whether signal transducer and activator of transcription 3 (STAT3) is responsible for the TFEB-mediated dysfunction of ALP in ischemic stroke. In the present study, we used AAV-mediated genetic knockdown and pharmacological blockade of p-STAT3 to investigate the role of p-STAT3 in regulating TFEB-mediated ALP dysfunction in rats subjected to permanent middle cerebral occlusion (pMCAO). The results showed that the level of p-STAT3 (Tyr705) in the rat cortex increased at 24 h after pMCAO and subsequently led to lysosomal membrane permeabilization (LMP) and ALP dysfunction. These effects can be alleviated by inhibitors of p-STAT3 (Tyr705) or by STAT3 knockdown. Additionally, STAT3 knockdown significantly increased the nuclear translocation of TFEB and the transcription of TFEB-targeted genes. Notably, TFEB knockdown markedly reversed STAT3 knockdown-mediated improvement in ALP function after pMCAO. This is the first study to show that the contribution of p-STAT3 (Tyr705) to ALP dysfunction may be partly associated with its inhibitory effect on TFEB transcriptional activity, which further leads to ischemic injury in rats.

CAPN1 (Calpain1)-Mediated Impairment of Autophagic Flux Contributes to Cerebral Ischemia-Induced Neuronal Damage.

Background and Purpose: CAPN1 (calpain1)­an intracellular Ca2+-regulated cysteine protease­can be activated under cerebral ischemia. However, the mechanisms by which CAPN1 activation promotes cerebral ischemic injury are not defined. Methods: In the present study, we used adeno-associated virus-mediated genetic knockdown and pharmacological blockade (MDL-28170) of CAPN1 to investigate the role of CAPN1 in the regulation of the autophagy-lysosomal pathway and neuronal damage in 2 models, rat permanent middle cerebral occlusion in vivo model and oxygen-glucose­deprived primary neuron in vitro model. Results: CAPN1 was activated in the cortex of permanent middle cerebral occlusion­operated rats and oxygen-glucose deprivation­exposed neurons. Genetic and pharmacological inhibition of CAPN1 significantly attenuated ischemia-induced lysosomal membrane permeabilization and subsequent accumulation of autophagic substrates in vivo and in vitro. Moreover, inhibition of CAPN1 increased autophagosome formation by decreasing the cleavage of the autophagy regulators BECN1 (Beclin1) and ATG (autophagy-related gene) 5. Importantly, the neuron-protective effect of MDL-28170 on ischemic insult was reversed by cotreatment with either class III-PI3K (phosphatidylinositol 3-kinase) inhibitor 3-methyladenine or lysosomal inhibitor chloroquine (chloroquine), suggesting that CAPN1 activation-mediated impairment of autophagic flux is crucial for cerebral ischemia-induced neuronal damage. Conclusions: The present study demonstrates for the first time that ischemia-induced CAPN1 activation impairs lysosomal function and suppresses autophagosome formation, which contribute to the accumulation of substrates and aggravate the ischemia-induced neuronal cell damage. Our work highlights the vital role of CAPN1 in the regulation of cerebral ischemia­mediated autophagy-lysosomal pathway defects and neuronal damage.

Tumor cell-imposed iron restriction drives immunosuppressive polarization of tumor-associated macrophages.

BACKGROUND: Tumor-associated macrophages (TAM) are immunosuppressive cells that contribute to impaired anti-cancer immunity. Iron plays a critical role in regulating macrophage function. However, it is still elusive whether it can drive the functional polarization of macrophages in the context of cancer and how tumor cells affect the iron-handing properties of TAM. In this study, using hepatocellular carcinoma (HCC) as a study model, we aimed to explore the effect and mechanism of reduced ferrous iron in TAM. METHODS: TAM from HCC patients and mouse HCC tissues were collected to analyze the level of ferrous iron. Quantitative real-time PCR was used to assess M1 or M2 signature genes of macrophages treated with iron chelators. A co-culture system was established to explore the iron competition between macrophages and HCC cells. Flow cytometry analysis was performed to determine the holo-transferrin uptake of macrophages. HCC samples from The Cancer Genome Atlas (TCGA) were enrolled to evaluate the prognostic value of transferrin receptor (TFRC) and its relevance to tumor-infiltrating M2 macrophages. RESULTS: We revealed that ferrous iron in M2-like TAM is lower than that in M1-like TAM. In vitro analysis showed that loss of iron-induced immunosuppressive M2 polarization of mouse macrophages. Further experiments showed that TFRC, the primary receptor for transferrin-mediated iron uptake, was overexpressed on HCC cells but not TAM. Mechanistically, HCC cells competed with macrophages for iron to upregulate the expression of M2-related genes via induction of HIF-1α, thus contributing to M2-like TAM polarization. We further clarified the oncogenic role of TFRC in HCC patients by TCGA. TFRC is significantly increased in varieties of malignancies, including HCC, and HCC patients with high TFRC levels have considerably shortened overall survival. Also, TFRC is shown to be positively related to tumor-infiltrating M2 macrophages. CONCLUSIONS: Collectively, we identified iron starvation through TFRC-mediated iron competition drives functional immunosuppressive polarization of TAM, providing new insight into the interconnection between iron metabolism and tumor immunity.

Risk and prognostic nomograms for colorectal neuroendocrine neoplasm with liver metastasis: a population-based study.

PURPOSE: Liver metastasis (LM) significantly shortens the survival time of colorectal neuroendocrine neoplasms (NENs) patients. This research aimed to explore risk and prognostic factors in colorectal NENs patients with LM and develop nomograms for predicting the risk of LM and survival probability quantitatively. METHODS: A total of 9926 colorectal NENs patients registered in the Surveillance, Epidemiology, and End Results (SEER) database between 2010 and 2017 were included. Risk factors for LM in colorectal NENs patients were identified by multivariate logistic regression analysis. Potential prognostic factors for colorectal NENs patients with LM were identified by multivariable Cox regression analysis. Nomograms were constructed for quantifying the probability of LM occurrence and survival. RESULTS: At diagnosis, 8.7% of colorectal NENs patients suffered LM, with 1-, 3-, and 5-year cancer-specific survival (CSS) rates of 44.3%, 26.5%, and 18.0%, respectively. Factors associated with LM occurrence included gender, age at diagnosis, primary tumor location, carcinoembryonic antigen (CEA), histological differentiation, T stage, and N stage. Age at diagnosis, race, histological differentiation, N stage, tumor size, primary tumor location, primary site surgery, and extraliver metastasis were prognostic factors of cancer-specific mortality. The area under the receiver operating characteristics (ROC) curve of the nomogram for predicting LM was 0.888 (95% CI: 0.877-0.898), and the C-index of the nomogram for estimating CSS probability was 0.705 (95% CI: 0.682-0.729). CONCLUSIONS: This research identified the risk and prognostic factors in colorectal NENs patients with LM. The nomograms constructed by this study can be convenient tools for facilitating clinical decision-making.

Upregulation of Excision Repair Cross-Complementation Group 6-Like (ERCC6L) Promotes Tumor Growth in Hepatocellular Carcinoma.

BACKGROUND: Excision repair cross-complementation group 6-like (ERCC6L) is overexpressed in some malignancies; however, its role in hepatocellular carcinoma (HCC) remains to be further investigated. AIMS: In the present study, we explored the expression and function of ERCC6L in HCC. METHODS AND RESULTS: We investigated the expression of ERCC6L by microarray analysis, using the Cancer Genome Atlas database, and by HCC tissue microarray. The results showed that ERCC6L expression was upregulated in tumor specimens and HCC cell lines. High ERCC6L expression in tumor tissues was significantly correlated with poor prognosis and could serve as an independent prognostic indicator for HCC patients. Results of in vitro and in vivo assays revealed that ERCC6L substantially promoted cell proliferation, and our flow cytometry analysis revealed that this was accomplished by acceleration of the G1/S transition. Finally, gene set enrichment analysis and western blotting results indicated that ERCC6L might regulate HCC proliferation by activating p53 signaling. CONCLUSIONS: Our study suggests that ERCC6L plays an important role in HCC proliferation and that it might serve as a promising therapeutic target in HCC.

Upregulated calcium-binding tyrosine phosphorylation-regulated protein-a/b regulates cell proliferation and apoptosis and predicts poor prognosis in hepatocellular carcinoma.

BACKGROUND: Calcium-binding tyrosine phosphorylation-regulated protein (CABYR) is a group of isoforms produced by alternative splicing and is overexpressed in human malignancies including hepatocellular carcinoma (HCC). However, the prognostic value and biological functions of its major protein isoforms, named CABYR-a/b (combined CABYR-a and CABYR-b), in HCC remain to be established. METHODS: CABYR-a/b expression was detected in HCC tissues and cell lines by quantitative real-time polymerase chain reaction and Western blot analysis. The correlation of CABYR-a/b expression with clinical characteristics and its prognosis impact were determined by statistical analysis. Finally, the biological functions and molecular mechanism of CABYR-a/b were also investigated using molecular biology approaches. RESULTS: The present research found that CABYR-a/b was markedly elevated in HCC specimens and cell lines. Upregulated CABYR-a/b level had positive association with tumor size and differentiation in patients. Moreover, cases with elevated CABYR-a/b level had poorer overall survival (OS) and disease-free survival (DFS) than those with reduced CABYR-a/b level. Multivariate analysis and prognostic nomograms demonstrated that CABYR-a/b overexpression was an independent predictive indicator for OS and DFS. The calibration curve for the odds of OS and DFS demonstrated that the prediction by nomograms was in excellent accordance with actual situation. CABYR-a/b downregulation suppressed cell proliferation and induced G1-phase arrest via decreasing cyclin D1 and cyclin dependent kinase 4, while promoted apoptosis by reducing B-cell lymphoma 2 (Bcl-2) and increasing Bcl-2-associated death promoter. CONCLUSION: Our research indicates that CABYR-a/b exerts an oncogenic effect on HCC development and may become a new prognostic indicator for patients with HCC.

OGDHL silencing promotes hepatocellular carcinoma by reprogramming glutamine metabolism.

BACKGROUND & AIMS: Mitochondrial dysfunction and subsequent metabolic deregulation are commonly observed in cancers, including hepatocellular carcinoma (HCC). When mitochondrial function is impaired, reductive glutamine metabolism is a major cellular carbon source for de novo lipogenesis to support cancer cell growth. The underlying regulators of reductively metabolized glutamine in mitochondrial dysfunction are not completely understood in tumorigenesis. METHODS: We systematically investigated the role of oxoglutarate dehydrogenase-like (OGDHL), one of the rate-limiting components of the key mitochondrial multi-enzyme OGDH complex (OGDHC), in the regulation of lipid metabolism in hepatoma cells and mouse xenograft models. RESULTS: Lower expression of OGDHL was associated with advanced tumor stage, significantly worse survival and more frequent tumor recurrence in 3 independent cohorts totaling 681 postoperative HCC patients. Promoter hypermethylation and DNA copy deletion of OGDHL were independently correlated with reduced OGDHL expression in HCC specimens. Additionally, OGDHL overexpression significantly inhibited the growth of hepatoma cells in mouse xenografts, while knockdown of OGDHL promoted proliferation of hepatoma cells. Mechanistically, OGDHL downregulation upregulated the α-ketoglutarate (αKG):citrate ratio by reducing OGDHC activity, which subsequently drove reductive carboxylation of glutamine-derived αKG via retrograde tricarboxylic acid cycling in hepatoma cells. Notably, silencing of OGDHL activated the mTORC1 signaling pathway in an αKG-dependent manner, inducing transcription of enzymes with key roles in de novo lipogenesis. Meanwhile, metabolic reprogramming in OGDHL-negative hepatoma cells provided an abundant supply of NADPH and glutathione to support the cellular antioxidant system. The reduction of reductive glutamine metabolism through OGDHL overexpression or glutaminase inhibitors sensitized tumor cells to sorafenib, a molecular-targeted therapy for HCC. CONCLUSION: Our findings established that silencing of OGDHL contributed to HCC development and survival by regulating glutamine metabolic pathways. OGDHL is a promising prognostic biomarker and therapeutic target for HCC. LAY SUMMARY: Hepatocellular carcinoma (HCC) is one of the most prevalent tumors worldwide and is correlated with a high mortality rate. In patients with HCC, lower expression of the enzyme OGDHL is significantly associated with worse survival. Herein, we show that silencing of OGDHL induces lipogenesis and influences the chemosensitization effect of sorafenib in liver cancer cells by reprogramming glutamine metabolism. OGDHL is a promising prognostic biomarker and potential therapeutic target in OGDHL-negative liver cancer.

Enhanced mLST8 Expression Correlates with Tumor Progression in Hepatocellular Carcinoma.

BACKGROUND: The mechanistic target of rapamycin (mTOR) pathway, containing mTOR complex 1 (mTORC1) and mTORC2, is dysregulated in multiple cancers, including hepatocellular carcinoma (HCC). Mammalian lethal with sec-13 protein 8 (mLST8) is a shared constituent of both mTORC1 and mTORC2, yet little is known regarding its role in HCC development. METHODS: mLST8 expression was detected in a total of 186 pairs of HCC and adjacent non-tumor specimens. The correlation between mLST8 level and clinicopathological features or prognostic significance were analyzed. The role of mLST8 on biological functions was also preliminarily studied. RESULTS: The study revealed that the mLST8 level was dramatically higher in HCC specimens than in adjacent non-tumor specimens. mLST8 overexpression positively correlated with tumor size, differentiation, and vessel invasion. Cases with elevated mLST8 level had more unfavorable overall survival (OS) and disease-free survival (DFS) than those with downregulated mLST8 level. Multivariate analysis demonstrated that mLST8 upregulation was an independent predictive marker for OS and DFS. Calibration curves from nomogram models indicated an excellent coherence between nomogram prediction and actual situation. Decision curve analysis proved that mLST8-based nomograms presented much higher predictive accuracy when compared with conventional clinical staging systems. Mechanistically, mLST8 enhanced cell proliferation and invasion through the AKT (protein kinase B) pathway. CONCLUSIONS: Our study demonstrates that mLST8 exerts an oncogenic role in HCC and may become a promising prognostic biomarker and therapeutic target for HCC patients.

Applicability of time fractional derivative models for simulating the dynamics and mitigation scenarios of COVID-19.

Fractional calculus provides a promising tool for modeling fractional dynamics in computational biology, and this study tests the applicability of fractional-derivative equations (FDEs) for modeling the dynamics and mitigation scenarios of the novel coronavirus for the first time. The coronavirus disease 2019 (COVID-19) pandemic radically impacts our lives, while the evolution dynamics of COVID-19 remain obscure. A time-dependent Susceptible, Exposed, Infectious, and Recovered (SEIR) model was proposed and applied to fit and then predict the time series of COVID-19 evolution observed over the last three months (up to 3/22/2020) in China. The model results revealed that 1) the transmission, infection and recovery dynamics follow the integral-order SEIR model with significant spatiotemporal variations in the recovery rate, likely due to the continuous improvement of screening techniques and public hospital systems, as well as full city lockdowns in China, and 2) the evolution of number of deaths follows the time FDE, likely due to the time memory in the death toll. The validated SEIR model was then applied to predict COVID-19 evolution in the United States, Italy, Japan, and South Korea. In addition, a time FDE model based on the random walk particle tracking scheme, analogous to a mixing-limited bimolecular reaction model, was developed to evaluate non-pharmaceutical strategies to mitigate COVID-19 spread. Preliminary tests using the FDE model showed that self-quarantine may not be as efficient as strict social distancing in slowing COVID-19 spread. Therefore, caution is needed when applying FDEs to model the coronavirus outbreak, since specific COVID-19 kinetics may not exhibit nonlocal behavior. Particularly, the spread of COVID-19 may be affected by the rapid improvement of health care systems which may remove the memory impact in COVID-19 dynamics (resulting in a short-tailed recovery curve), while the death toll and mitigation of COVID-19 can be captured by the time FDEs due to the nonlocal, memory impact in fatality and human activities.

Efficacy of Nucleoside Analogs for Chronic Hepatitis B Virus-Related Hepatocellular Carcinoma After Curative Treatment: A Meta-Analysis.

BACKGROUND AND AIM: The efficacy of nucleoside analogs (NAs) for hepatitis B virus (HBV)-related hepatocellular carcinoma (HCC) after curative treatment remains unclear. The present study aimed to evaluate the efficacy of these agents by conducting a comprehensive meta-analysis of available studies. METHODS: We searched several databases including Pubmed, Embase, Cochrane Library, Clinical Trials, and Web of Science, according to PRISMA guidelines. We considered all randomized controlled trials and cohort studies that met the inclusion criteria. Statistical analyses were conducted using Review Manager 5.3 and Stata 14.0. RESULTS: Twenty-one studies with 8752 participants were included in the final analysis. The pooled data showed that patients treated with NAs had significantly lower 1- and 3-year HCC recurrence rates (relative risk [RR] 0.76, 95% confidence interval [CI] 0.65-0.90; P = 0.001 and RR 0.79, 95% CI 0.71-0.88; P < 0.001, respectively), but there was no difference in 5-year recurrence rates (RR 0.87, 95% CI 0.74-1.03; P = 0.10). Regarding overall survival (OS), patients treated with NAs had significantly higher 1-, 3-, and 5-year OS rates (RR 1.05, 95% CI 1.02-1.08; P = 0.003; RR 1.25, 95% CI 1.16-1.34; P < 0.001; and RR 1.28, 95% CI 1.18-1.39; P < 0.001, respectively). CONCLUSION: NA therapy has the potential to reduce the risk of early recurrence and improve OS in patients with HBV-related HCC after curative treatment, compared with placebo or no treatment. Further research including more homogeneous studies with large sample sizes is required to improve the reliability of these conclusions.

Microarray Expression Profiling of microRNAs Reveals Potential Biomarkers for Hepatocellular Carcinoma.

Hepatocellular carcinoma (HCC) remains a major health problem for delayed diagnosis, inefficient surveillance and poor prognosis. Recent studies have indicated that non-coding RNAs contribute to the development of new strategies for diagnosis and treatment of HCC. In the present study, we employed 18 pairs of HCC and matched non-tumor tissues for the identification of differentially expressed microRNAs (miRNAs) in HCC, among which 7 paired specimens were selected randomly for microarray detection. Totally, twenty-three miRNAs were screened out to have statistically significant differences with the threshold of P < 0.01 and fold-change ≥ 2.0 or ≤ 0.5 using miRNA microarray. In the validation stage, two miRNAs exhibited higher expression levels in the HCC tissues compared with those in the matched non-tumor tissues, whereas the expression levels of ten miRNAs were lower in the HCC tissues than those in the matched non-tumor tissues. In further analysis, eight miRNAs, including miR-4270, miR-125b-5p, miR-199a-3p, miR-10a-5p, miR-424-5p, miR-195-5p, miR-106b-5p and miR-3651, were retained, when another constraint about the signal intensity of microarray probes was established. Among these miRNAs, our study was the first to show the higher expression level of miR-3651 and the lower expression level of miR-4270 in HCC. The areas under the receiver-operating-characteristic curve values of miR-3651 and miR-4270 were 0.730 and 0.967, respectively, indicating their potential diagnostic values. Our results may help provide the context for expanded interpretations of miRNA studies involved in the progression of liver disease, potentially serving as a diagnostic tool of HCC.

High Volumetric Capacity of Hollow Structured SnO2@Si Nanospheres for Lithium-Ion Batteries.

A novel design of hollow structured SnO2@Si nanospheres was presented, which not only demonstrates high volumetric capacity as anode of LIBs, but also prevents aggregation of Sn and confines solid electrolyte interphase thickening. An impressive volumetric specific capacity of 1030 mAh cm-3 was maintained after 500 cycles. The electrochemical impedance spectroscopy and differential scanning calorimetry indicated that solid electrolyte interphase can be confined in pores of as-prepared hollow structured SnO2@Si.

A Graphene Composite Film Based Wearable Far-Infrared Therapy Apparatus (GRAFT) for Effective Prevention of Postoperative Peritoneal Adhesion.

Postoperative peritoneal adhesion (PPA) is the most frequent complication after abdominal surgery. Current anti-adhesion strategies largely rely on the use of physical separating barriers creating an interface blocking peritoneal adhesion, which cannot reduce inflammation and suffers from limited anti-adhesion efficacy with unwanted side effects. Here, by exploiting the alternative activated macrophages to alleviate inflammation in adhesion development, a flexible graphene-composite-film (F-GCF) generating far-infrared (FIR) irradiation that effectively modulates the macrophage phenotype toward the anti-inflammatory M2 type, resulting in reduced PPA formation, is designed. The anti-adhesion effect of the FIR generated by F-GCF is determined in the rat abdominal wall abrasion-cecum defect models, which exhibit reduced incidence and area of PPA by 67.0% and 92.1% after FIR treatment without skin damage, significantly superior to the clinically used chitosan hydrogel. Notably, within peritoneal macrophages, FIR reduces inflammation reaction and promotes tissue plasminogen activator (t-PA) level via the polarization of peritoneal macrophages through upregulating Nr4a2 expression. To facilitate clinical use, a wirelessly controlled, wearable, F-GCF-based FIR therapy apparatus (GRAFT) is further developed and its remarkable anti-adhesion ability in the porcine PPA model is revealed. Collectively, the physical, biochemical, and in vivo preclinical data provide compelling evidence demonstrating the clinical-translational value of FIR in PPA prevention.

Multi-Omics profiling identifies aldehyde dehydrogenase 2 as a critical mediator in the crosstalk between Treg-mediated immunosuppression microenvironment and hepatocellular carcinoma.

Dysregulation of the aldehyde dehydrogenase (ALDH) family has been implicated in various pathological conditions, including cancer. However, a systematic evaluation of ALDH alterations and their therapeutic relevance in hepatocellular carcinoma (HCC) remains lacking. Herein, we found that 15 of 19 ALDHs were transcriptionally dysregulated in HCC tissues compared to normal liver tissues. A four gene signature, including ALDH2, ALDH5A1, ALDH6A1, and ALDH8A1, robustly predicted prognosis and defined a high-risk subgroup exhibiting immunosuppressive features like regulatory T cell (Tregs) infiltration. Single-cell profiling revealed selective overexpression of tumor necrosis factor receptor superfamily member 18 (TNFRSF18) on Tregs, upregulated in high-risk HCC patients. We identified ALDH2 as a tumor suppressor in HCC, with three novel phosphorylation sites mediated by protein kinase C zeta that enhanced enzymatic activity. Mechanistically, ALDH2 suppressed Tregs differentiation by inhibiting ß-catenin/TGF-ß1 signaling in HCC. Collectively, our integrated multi-omics analysis defines an ALDH-Tregs-TNFRSF18 axis that contributes to HCC pathogenesis and represents potential therapeutic targets for this aggressive malignancy.

PRP19 Enhances Esophageal Squamous Cell Carcinoma Progression by Reprogramming SREBF1-Dependent Fatty Acid Metabolism.

Lipid metabolism reprogramming is a recognized hallmark of cancer cells. Identification of the underlying regulators of metabolic reprogramming in esophageal squamous cell carcinoma (ESCC) could uncover potential therapeutic targets to improve treatment. Here, we demonstrated that pre-mRNA processing factor 19 (PRP19) mediates reprogramming of lipid metabolism in ESCC. Expression of PRP19 was significantly upregulated in multiple ESCC cohorts and was correlated with poor clinical prognosis. PRP19 promoted ESCC proliferation in vitro and in vivo. Upregulation of PRP19 enhanced fatty acid synthesis through sterol regulatory element-binding protein 1 (SREBF1), a major transcription factor of lipid synthase. Moreover, PRP19 enhanced the stability of SREBF1 mRNA in an N6-methyladenosine-dependent manner. Overall, this study shows that PRP19-mediated fatty acid metabolism is crucial for ESCC progression. Targeting PRP19 is a potential therapeutic approach to reverse metabolic reprogramming in patients with ESCC. SIGNIFICANCE: Upregulation of pre-mRNA processing factor 19 (PRP19) contributes to esophageal squamous cell carcinoma progression by reprogramming SREBF1-dependent fatty acid metabolism, identifying PRP19 as a potential prognostic biomarker and therapeutic target.

Development of a Formability Prediction Model for Aluminium Sandwich Panels with Polymer Core.

In the present work, the compatibility relationship on the failure criteria between aluminium and polymer was established, and a mechanics-based model for a three-layered sandwich panel was developed based on the M-K model to predict its Forming Limit Diagram (FLD). A case study for a sandwich panel consisting of face layers from AA5754 aluminium alloy and a core layer from polyvinylidene difluoride (PVDF) was subsequently conducted, suggesting that the loading path of aluminium was linear and independent of the punch radius, while the risk for failure of PVDF increased with a decreasing radius and an increasing strain ratio. Therefore, the developed formability model would be conducive to the safety evaluation on the plastic forming and critical failure of composite sandwich panels.