Blockade of CaV3 calcium channels and induction of G0/G1 cell cycle arrest in colon cancer cells by gossypol.

BACKGROUND AND PURPOSE: Gastrointestinal tumours overexpress voltage-gated calcium (CaV3) channels (CaV3.1, 3.2 and 3.3). CaV3 channels regulate cell growth and apoptosis colorectal cancer. Gossypol, a polyphenolic aldehyde found in the cotton plant, has anti-tumour properties and inhibits CaV3 currents. A systematic study was performed on gossypol blocking mechanism on CaV3 channels and its potential anticancer effects in colon cancer cells, which express CaV3 isoforms. EXPERIMENTAL APPROACH: Transcripts for CaV3 proteins were analysed in gastrointestinal cancers using public repositories and in human colorectal cancer cell lines HCT116, SW480 and SW620. The gossypol blocking mechanism on CaV3 channels was investigated by combining heterologous expression systems and patch-clamp experiments. The anti-tumoural properties of gossypol were estimated by cell proliferation, viability and cell cycle assays. Ca2+ dynamics were evaluated with cytosolic and endoplasmic reticulum (ER) Ca2+ indicators. KEY RESULTS: High levels of CaV3 transcripts correlate with poor prognosis in gastrointestinal cancers. Gossypol blockade of CaV3 isoforms is concentration- and use-dependent interacting with the closed, activated and inactivated conformations of CaV3 channels. Gossypol and CaV3 channels down-regulation inhibit colorectal cancer cell proliferation by arresting cell cycles at the G0/G1 and G2/M phases, respectively. CaV3 channels underlie the vectorial Ca2+ uptake by endoplasmic reticulum in colorectal cancer cells. CONCLUSION AND IMPLICATIONS: Gossypol differentially blocked CaV3 channel and its anticancer activity was correlated with high levels of CaV3.1 and CaV3.2 in colorectal cancer cells. The CaV3 regulates cell proliferation and Ca2+ dynamics in colorectal cancer cells. Understanding this blocking mechanism maybe improve cancer therapies.

Effectiveness and mechanisms of combined use of antioxidant nutrients in protecting against oxidative stress-induced neuronal loss and related neurological deficits.

BACKGROUND: Oxidative stress is a well-known pathological factor driving neuronal loss and age-related neurodegenerative diseases. Melatonin, coenzyme Q10 and lecithin are three common nutrients with an antioxidative capacity. Here, we examined the effectiveness of them administrated individually and in combination in protecting against oxidative stress-induced neuronal death in vitro, and neurodegenerative conditions such as Alzheimer's disease and associated deficits in vivo. METHODS: Mouse neuroblastoma Neuro-2a (N2a) cells were exposed with H2O2 for 6 h, and subsequently treated with melatonin, coenzyme Q10, and lecithin alone or in combination for further 24 h. Cell viability was assessed using the CCK-8 assay. Eight-week-old male mice were intraperitoneally injected with D-(+)-galactose for 10 weeks and administrated with melatonin, coenzyme Q10, lecithin, or in combination for 5 weeks starting from the sixth week, followed by behavioral tests to assess the effectiveness in mitigating neurological deficits, and biochemical assays to explore the underlying mechanisms. RESULTS: Exposure to H2O2 significantly reduced the viability of N2a cells and increased oxidative stress and tau phosphorylation, all of which were alleviated by treatment with melatonin, coenzyme Q10, lecithin alone, and, most noticeably, by combined treatment. Administration of mice with D-(+)-galactose-induced oxidative stress and tau phosphorylation, brain aging, impairments in learning and memory, anxiety- and depression-like behaviors, and such detrimental effects were mitigated by melatonin, coenzyme Q10, lecithin alone, and, most consistently, by combined treatment. CONCLUSIONS: These results suggest that targeting oxidative stress via supplementation of antioxidant nutrients, particularly in combination, is a better strategy to alleviate oxidative stress-mediated neuronal loss and brain dysfunction due to age-related neurodegenerative conditions.

Evolutionary trajectory of TRPM2 channel activation by adenosine diphosphate ribose and calcium.

Ion channel activation upon ligand gating triggers a myriad of biological events and, therefore, evolution of ligand gating mechanism is of fundamental importance. TRPM2, a typical ancient ion channel, is activated by adenosine diphosphate ribose (ADPR) and calcium and its activation has evolved from a simple mode in invertebrates to a more complex one in vertebrates, but the evolutionary process is still unknown. Molecular evolutionary analysis of TRPM2s from more than 280 different animal species has revealed that, the C-terminal NUDT9-H domain has evolved from an enzyme to a ligand binding site for activation, while the N-terminal MHR domain maintains a conserved ligand binding site. Calcium gating pattern has also evolved, from one Ca2+-binding site as in sea anemones to three sites as in human. Importantly, we identified a new group represented by olTRPM2, which has a novel gating mode and fills the missing link of the channel gating evolution. We conclude that the TRPM2 ligand binding or activation mode evolved through at least three identifiable stages in the past billion years from simple to complicated and coordinated. Such findings benefit the evolutionary investigations of other channels and proteins.

TRPM2 protects against cisplatin-induced acute kidney injury and mitochondrial dysfunction via modulating autophagy.

Background: Cisplatin is a widely used anti-tumor agent but its use is frequently limited by nephrotoxicity. Transient receptor potential melastatin 2 (TRPM2) is a non-selective cation channel which is generally viewed as a sensor of oxidative stress, and increasing evidence supports its link with autophagy, a critical process for organelle homeostasis. Methods: Cisplatin-induced cell injury and mitochondrial damage were both assessed in WT and Trpm2-knockout mice and primary cells. RNA sequencing, immunofluorescence staining, immunoblotting and flowcytometry were applied to interpret the mechanism of TRPM2 in cisplatin nephrotoxicity. Results: Knockout of TRPM2 exacerbates renal dysfunction, tubular injury and cell apoptosis in a model of acute kidney injury (AKI) induced by treatment with cisplatin. Cisplatin-caused tubular mitochondrial damage is aggravated in TRPM2-deficient mice and cells and, conversely, alleviated by treatment with Mito-TEMPO, a mitochondrial ROS scavenger. TRPM2 deficiency hinders cisplatin-induced autophagy via blockage of Ca2+ influx and subsequent up-regulation of AKT-mTOR signaling. Consistently, cisplatin-induced tubular mitochondrial damage, cell apoptosis and renal dysfunction in TRPM2-deficient mice are mitigated by treatment with a mTOR inhibitor. Conclusion: Our results suggest that the TRPM2 channel plays a protective role in cisplatin-induced AKI via modulating the Ca2+-AKT-mTOR signaling pathway and autophagy, providing novel insights into the pathogenesis of kidney injury.

DpdtpA, A Multi-metal Ion Chelator, Attenuates Tau Phosphorylation and Microglial Inflammatory Response via Regulating the PI3K/AKT/GSK-3ß Signal Pathways.

Tau protein hyperphosphorylation and formation of intracellular neurofibrillary tangles (NFTs) are one of the histopathological hallmarks of Alzheimer's disease (AD) and positively correlated with the severity of AD symptoms. NFTs contain a large number of metal ions that play an important role in regulating tau protein phosphorylation and AD progression. Extracellular tau induces primary phagocytosis of stressed neurons and neuronal loss by activating microglia. Here, we studied the effects of a multi-metal ion chelator, DpdtpA, on tau-induced microglial activation and inflammatory responses and the underlying mechanisms. Treatment with DpdtpA attenuated the increase in the expression of NF-κB and production of inflammatory cytokines, IL-1ß, IL-6 and IL-10, in rat microglial cells induced by expression of human tau40 proteins. Treatment with DpdtpA also suppressed tau protein expression and phosphorylation. Moreover, treatment with DpdtpA prevented tau-induced activation of glycogen synthase kinase-3ß (GSK-3ß) and inhibition of phosphatidylinositol-3-hydroxy kinase (PI3K)/AKT. Collectively, these results show that DpdtpA can attenuate tau phosphorylation and inflammatory responses of microglia by regulating the PI3K/AKT/GSK-3ß signal pathways, providing a new option to alleviate neuroinflammation for the treatment of AD.

TRPM2 regulates cell cycle through the Ca2+-CaM-CaMKII signaling pathway to promote HCC.

BACKGROUND: HCC is one of the most common causes of cancer-related deaths. Transient receptor potential melastatin 2 (TRPM2), a Ca2+-permeable cation channel, was reported to be involved in carcinogenesis and tumor growth recently. However, whether TRPM2 is involved in the pathogenesis and progression of HCC remains unclear. Herein, we systematically elucidated the functional role of TRPM2 in HCC cell cycle regulation and proliferation. APPROACH AND RESULTS: We determine TRPM2 expression to be strongly upregulated in the tumor tissues of HCC patients and associated with a negative prognosis. TRPM2 is highly expressed in HCC cell lines Huh-7 and HepG2 cells, rather than in normal hepatocytes. Inhibition or silencing of TRPM2, or inhibition of the downstream Ca2+-CaM-CaMKII signaling pathway, significantly suppressed the proliferation of Huh-7 and HepG2 cells by arresting the cell cycle at the G1/S phase, accompanied with reduced expression of G1/S checkpoint proteins. Importantly, inhibition or depletion of TRPM2 remarkably slowed down the growth of patient-derived xenografts and Huh-7 xenografts in mice. CONCLUSION: Our results indicate that TRPM2 promotes HCC cell proliferation via activating the Ca2+-CaM-CaMKII signaling pathway to induce the expression of the key G1/S regulatory proteins and accelerate the cell cycle. This study provides compelling evidence of TRPM2 involvement in a previously unrecognized mechanism that drives HCC progression and demonstrates that TRPM2 is a potential target for HCC treatment.

Leveraging the ATP-P2X7 receptor signalling axis to alleviate traumatic CNS damage and related complications.

The P2X7 receptor is an exceptional member of the P2X purinergic receptor family, with its activation requiring high concentrations of extracellular adenosine 5'-triphosphate (ATP) that are often associated with tissue damage and inflammation. In the central nervous system (CNS), it is highly expressed in glial cells, particularly in microglia. In this review, we discuss the role and mechanisms of the P2X7 receptor in mediating neuroinflammation and other pathogenic events in a variety of traumatic CNS damage conditions, which lead to loss of neurological and cognitive functions. We raise the perspective on the steady progress in developing CNS-penetrant P2X7 receptor-specific antagonists that leverage the ATP-P2X7 receptor signaling axis as a potential therapeutic strategy to alleviate traumatic CNS damage and related complications.

Piezo1 channel-mediated Ca2+ signaling inhibits lipopolysaccharide-induced activation of the NF-κB inflammatory signaling pathway and generation of TNF-α and IL-6 in microglial cells.

Microglial cells are crucial in maintaining central nervous system (CNS) homeostasis and mediating CNS disease pathogenesis. Increasing evidence supports that alterations in the mechanical properties of CNS microenvironments influence glial cell phenotypes, but the mechanisms regulating microglial cell function remain elusive. Here, we examined the mechanosensitive Piezo1 channel in microglial cells, particularly, how Piezo1 channel activation regulates pro-inflammatory activation and production of pro-inflammatory cytokines, using BV2 and primary microglial cells. Piezo1 expression in microglial cells was detected both at mRNA and protein levels. Application of Piezo1 channel activator Yoda1 induced Ca2+ flux to increase intracellular Ca2+ concentration that was reduced by treatment with ruthenium red, a Piezo1 inhibitor, or Piezo1-specific siRNA, supporting that Piezo1 functions as a cell surface Ca2+ -permeable channel. Priming with lipopolysaccharide (LPS) induced microglial cell activation and production of TNF-α and IL-6, which were inhibited by treatment with Yoda1. Furthermore, LPS priming induced the activation of ERK, p38 MAPKs, and NF-κB. LPS-induced activation of NF-κB, but not ERK and p38, was inhibited by treatment with Yoda1. Yoda1-induced inhibition was blunted by siRNA-mediated depletion of Piezo1 expression and, furthermore, treatment with BAPTA-AM to prevent intracellular Ca2+ increase. Collectively, our results support that Piezo1 channel activation downregulates the pro-inflammatory function of microglial cells, especially production of TNF-α and IL-6, by initiating intracellular Ca2+ signaling to inhibit the NF-κB inflammatory signaling pathway. These findings reveal Piezo1 channel activation as a previously unrecognized mechanism regulating microglial cell function, raising an interesting perspective on targeting this molecular mechanism to alleviate neuroinflammation and associated CNS pathologies.

Sustainable development of factory aquaculture through automation of ultraviolet parasiticide for the prevention and control of cryptocaryoniasis.

BACKGROUND: Cryptocaryon irritans infestations on marine teleosts are a considerable burden on factory mariculture. Ultraviolet (UV) light can kill C. irritans under laboratory conditions. However, a rational method for using UV in factory aquaculture to control cryptocaryoniasis has not been developed. This study focused on evaluating the killing effect of UV on protomonts and tomonts of C. irritans and established an automatic UV parasiticide device for the prevention and control of cryptocaryoniasis in marine teleosts. RESULTS: The survival rate of protomonts and tomonts decreased with an increase in the UV irradiation dose. All the protomonts and tomonts died within 14 and 24 min, respectively. The lowest UV lethal doses of protomonts and tomonts of C. irritans were 2.0 × 106 and 3.5 × 106 µWs cm-2 , respectively. Exposure of protomonts and tomonts to lethal doses of UV radiation led to shrinkage and severe dissolution of the protoplasm, causing abnormal development of cells. The survival rate of artificially infected Larimichthys crocea (treatment group, group A) was 83.33% at the end of the test (day 14) after disinfection using the automatic UV parasiticide device, whereas that of the control group (group C) was 90.00% (p < 0.05). However, all artificially infected L. crocea without disinfection using the automatic UV parasiticide device (untreated group, group B) died on day 8. CONCLUSION: The automation of traditional physical methods conforms to the sustainable development of aquaculture and provides a theoretical reference for the prevention and control of cryptocaryoniasis in mariculture. © 2022 Society of Chemical Industry.

Hsa-circ-0052001 promotes gastric cancer cell proliferation and invasion via the MAPK pathway.

BACKGROUND: Gastric cancer (GC) ranks fourth among the causes of death from malignant tumors in the world. Studies have implicated the dysregulation of circRNAs with GC. However, the relationship between hsa-circ-0052001 and GC is unclear. METHODS: In our current study, we assessed the expression levels of hsa-circ-0052001 in GC cells and tissues using quantitative real-time PCR (qPCR). The role of hsa-circ-0052001 expression on the proliferation and invasion of GC cells was assessed using in vitro experiments. The role of hsa-circ-0052001 on the proliferation of GC cells was also analyzed using in vivo models. The pathways downstream of hsa-circ-0052001 were identified using bioinformatics analyses, western blot (WB) assays, and qRT-PCR. RESULTS: We found that compared with normal gastric mucosa epithelial cells and adjacent paracancer tissues, hsa-circ-0052001 was overexpressed in GC cells and tissues. Also, the hsa-circ-0052001 level was linked to patient clinicopathological characteristics of GC. Cell proliferation and metastatic ability were inhibited in gastric cancer cells when hsa-circ-0052001 was knocked down in vitro and cancer growth in vivo. Mechanistically, hsa-circ-0052001 promoted the carcinogenesis of GC cells via the MAPK signal pathway. CONCLUSION: Hsa-circ-0052001 functions as a tumor gene in promoting the progression of GC through MAPK pathway, which has provided a promising target for patients with GC.

A Machine Learning-Modified Novel Nomogram to Predict Perioperative Blood Transfusion of Total Gastrectomy for Gastric Cancer.

Background: Perioperative blood transfusion reserves are limited, and the outcome of blood transfusion remains unclear. Therefore, it is important to prepare plans for perioperative blood transfusions. This study aimed to establish a risk assessment model to guide clinical patient management. Methods: This retrospective comparative study involving 513 patients who had total gastrectomy (TG) between January 2018 and January 2021 was conducted using propensity score matching (PSM). The influencing factors were explored by logistic regression, correlation analysis, and machine learning; then, a nomogram was established. Results: After assessment of the importance of factors through machine learning, blood loss, preoperative controlling nutritional status (CONUT), hemoglobin (Hb), and the triglyceride-glucose (TyG) index were considered as the modified transfusion-related factors. The modified model was not considered to be different from the original model in terms of performance, but is simpler. A nomogram was created, with a C-index of 0.834, and the decision curve analysis (DCA) demonstrated good clinical benefit. Conclusions: A nomogram was established and modified with machine learning, which suggests the importance of the patient's integral condition. This emphasizes that caution should be exercised regarding transfusions, and, if necessary, preoperative nutritional interventions or delayed surgery should be implemented for safety.

P2x4 receptor promotes mammary cancer progression by sustaining autophagy and associated mesenchymal transition.

Metastatic progression is a major burden for breast cancer patients and is associated with the ability of cancer cells to overcome stressful conditions, such as nutrients deprivation and hypoxia, and to gain invasive properties. Autophagy and epithelial-to-mesenchymal transition are critical contributors to these processes. Here, we show that the P2X4 purinergic receptor is upregulated in breast cancer biopsies from patients and it is primarily localised in endolysosomes. We demonstrate that P2X4 enhanced invasion in vitro, as well as mammary tumour growth and metastasis in vivo. The pro-malignant role of P2X4 was mediated by the regulation of lysosome acidity, the promotion of autophagy and cell survival. Furthermore, the autophagic activity was associated with epithelial-to-mesenchymal transition (EMT), and this role of P2X4 was even more pronounced under metabolic challenges. Pharmacological and gene silencing of P2X4 inhibited both autophagy and EMT, whereas its rescue in knocked-down cells led to the restoration of the aggressive phenotype. Together, our results demonstrate a previously unappreciated role for P2X4 in regulating lysosomal functions and fate, promoting breast cancer progression and aggressiveness.

GelMA Hydrogel Reinforced with 3D Printed PEGT/PBT Scaffolds for Supporting Epigenetically-Activated Human Bone Marrow Stromal Cells for Bone Repair.

Epigenetic approaches using the histone deacetylase 2 and 3 inhibitor-MI192 have been reported to accelerate stem cells to form mineralised tissues. Gelatine methacryloyl (GelMA) hydrogels provide a favourable microenvironment to facilitate cell delivery and support tissue formation. However, their application for bone repair is limited due to their low mechanical strength. This study aimed to investigate a GelMA hydrogel reinforced with a 3D printed scaffold to support MI192-induced human bone marrow stromal cells (hBMSCs) for bone formation. Cell culture: The GelMA (5 wt%) hydrogel supported the proliferation of MI192-pre-treated hBMSCs. MI192-pre-treated hBMSCs within the GelMA in osteogenic culture significantly increased alkaline phosphatase activity (p ≤ 0.001) compared to control. Histology: The MI192-pre-treated group enhanced osteoblast-related extracellular matrix deposition and mineralisation (p ≤ 0.001) compared to control. Mechanical testing: GelMA hydrogels reinforced with 3D printed poly(ethylene glycol)-terephthalate/poly(butylene terephthalate) (PEGT/PBT) scaffolds exhibited a 1000-fold increase in the compressive modulus compared to the GelMA alone. MI192-pre-treated hBMSCs within the GelMA-PEGT/PBT constructs significantly enhanced extracellular matrix collagen production and mineralisation compared to control (p ≤ 0.001). These findings demonstrate that the GelMA-PEGT/PBT construct provides enhanced mechanical strength and facilitates the delivery of epigenetically-activated MSCs for bone augmentation strategies.

Billroth II anastomosis maintains SMI and BMI better than Roux-en-Y anastomosis following totally laparoscopic distal gastrectomy: a propensity score-matched study.

BACKGROUND: Gastric cancer is a major public health problem around the globe. With the standardization of tumor treatment, surgery continues to be the most important treatment method for gastric cancer. However, changes in body composition and nutrition index parameters in patients with Billroth II and Roux-en-Y anastomosis following totally laparoscopic distal gastrectomy (TLDG) remain unclear. METHODS: This was a single-center retrospective study. A total of 369 patients who underwent TLDG at the First Affiliated Hospital of Soochow University (Suzhou, China) between January 2016 and February 2019 were included and assigned to the Billroth II group or Roux-en-Y group according to the anastomosis method. After propensity score matching, body composition and relevant clinical data were compared between the two groups. RESULTS: The operation time for the Billroth II group was significantly shorter than for the Roux-en-Y group (174.12 ± 39.33 min vs. 229.19 ± 28.12 min, P < 0.001). In addition, the Billroth II group showed lower skeletal muscle loss. Specifically, the Billroth II group showed a - 4.77 ± 4.88% change in the skeletal muscle index (SMI), whereas the Roux-en-Y group showed a - 11.89 ± 8.68% change (P = 0.001). The Billroth II group also showed a smaller decrease in BMI than the Roux-en-Y group (- 6.67 ± 7.76% vs. - 13.12 ± 10.79%, P = 0.018). CONCLUSIONS: These results suggest that Billroth II anastomosis after TLDG has advantages over Roux-en-Y for maintaining patient body composition, especially in terms of SMI, and may serve as a useful reference when choosing an anastomosis method.

ENO1 contributes to 5-fluorouracil resistance in colorectal cancer cells via EMT pathway.

Introduction: Chemoresistance is a major barrier in the treatment of colorectal cancer (CRC) and many other cancers. ENO1 has been associated with various biological characteristics of CRC. This study aimed to investigate the function of ENO1 in regulating 5-Fluorouracil (5-FU) resistance in CRC. Methods: ENO1 level in 120 pairs of tumor tissues and adjacent normal tissues was examined by immunohistochemistry, and the correlation between ENO1 expression and prognosis was explored by survival analysis. Its role and potential mechanisms in regulating 5-FU resistance in CRC were studied by Western blotting, MTT assay, colony formation assay and transwell invasion assay. Murine xenograft assay was implied to verify the results in vivo. Results: Our study indicated that ENO1 was elevated in CRC tissues and was associated with poor patient prognosis. High levels of ENO1 expression were detected as a significant influencing factor for overall survival. Furthermore, ENO1 expression was found to have increased in drug-resistant cells (HCT116/5-FU and SW620/5-FU) constructed by increasing concentrations of 5-FU. Knockdown of ENO1 markedly increased the drug susceptibility and inhibited the proliferation and migration ability of HCT116/5-FU and SW620/5-FU cells. It was found that down-regulation of ENO1 inhibited the epithelial-mesenchymal transformation (EMT) signaling process. Finally, a murine xenograft assay verified that the depletion of ENO1 alleviated 5-FU resistance. Conclusion: This study identified that ENO1 regulated 5-FU resistance via the EMT pathway and may be a novel target in the prevention and treatment of 5-FUresistant CRC.

Tyrosine 288 in the extracellular domain of the human P2X7 receptor is critical for receptor function revealed by structural modeling and site-directed mutagenesis.

The P2X7 receptor (P2X7R) is a calcium-permeable cation channel activated by high concentrations of extracellular ATP. It plays a role in vital physiological processes, particularly in innate immunity, and is dysregulated in pathological conditions such as inflammatory diseases, neurodegenerative diseases, mood disorders, and cancers. Structural modeling of the human P2X7R (hP2X7R) based on the recently available structures of the rat P2X7 receptor (rP2XR) in conjunction with molecular docking predicts the orientation of tyrosine at position 288 (Y288) in the extracellular domain to face ATP. In this short communication, we combined site-directed mutagenesis and whole-cell patch-clamp recording to investigate the role of this residue in the hP2X7R function. Mutation of this extracellular residue to amino acids with different properties massively impaired current responses to both ATP and BzATP, suggesting that Y288 is important for normal receptor function. Such a finding facilitates development of an in-depth understanding of the molecular basis of hP2X7R structure-function relationships.

Structural and functional basis of the selectivity filter as a gate in human TRPM2 channel.

Transient receptor potential melastatin 2 (TRPM2), a Ca2+-permeable cation channel, is gated by intracellular adenosine diphosphate ribose (ADPR), Ca2+, warm temperature, and oxidative stress. It is critically involved in physiological and pathological processes ranging from inflammation to stroke to neurodegeneration. At present, the channel's gating and ion permeation mechanisms, such as the location and identity of the selectivity filter, remain ambiguous. Here, we report the cryo-electron microscopy (cryo-EM) structure of human TRPM2 in nanodisc in the ligand-free state. Cryo-EM map-guided computational modeling and patch-clamp recording further identify a quadruple-residue motif as the ion selectivity filter, which adopts a restrictive conformation in the closed state and acts as a gate, profoundly contrasting with its widely open conformation in the Nematostella vectensis TRPM2. Our study reveals the gating of human TRPM2 by the filter and demonstrates the feasibility of using cryo-EM in conjunction with computational modeling and functional studies to garner structural information for intrinsically dynamic but functionally important domains.

CircPTK2 Suppresses the Progression of Gastric Cancer by Targeting the MiR-196a-3p/AATK Axis.

BACKGROUND: Gastric cancer is a type of malignant tumor with high morbidity and mortality. It has been shown that circular RNAs (circRNAs) exert critical roles in gastric cancer progression via working as microRNA (miRNA) sponges to regulate gene expression. However, the role and potential molecular mechanism of circRNAs in gastric cancer remain largely unknown. METHODS: CircPTK2 (hsa_circ_0005273) was identified by bioinformatics analysis and validated by RT-qPCR assay. Bioinformatics prediction, dual-luciferase reporter, and RNA pull-down assays were used to determine the interaction between circPTK2, miR-196a-3p, and apoptosis-associated tyrosine kinase 1 (AATK). RESULTS: The level of circPTK2 was markedly downregulated in gastric cancer tissues and gastric cancer cells. Upregulation of circPTK2 significantly suppressed the proliferation, migration, and invasion of gastric cancer cells, while circPTK2 knockdown exhibited opposite effects. Mechanically, circPTK2 could competitively bind to miR-196a-3p and prevent miR-196a-3p to reduce the expression of AATK. In addition, overexpression of circPTK2 inhibited tumorigenesis in a xenograft mouse model of gastric cancer. CONCLUSION: Collectively, circPTK2 functions as a tumor suppressor to suppress gastric cancer cell proliferation, migration, and invasion through regulating the miR-196a-3p/AATK axis, suggesting that circPTK2 may serve as a novel therapeutic target for gastric cancer.

A Novel Nomogram for Prediction of Early Postoperative Complications of Total Gastrectomy for Gastric Cancer.

BACKGROUND: Accurate prediction of postoperative complications is especially important for the formulation of treatment plans for patients with total gastrectomy (TG) for gastric cancer (GC). The purpose of this study was to establish a risk assessment model for early postoperative complications. METHODS: This retrospective study involved 363 patients with GC who underwent TG from January 2019 to December 2020. The influencing factors were explored by univariate and multivariable logistic regression; then, a nomogram was established and verified by internal verification. RESULTS: Linear stapler (OR=2.501, P=0.030), age (OR=1.052, P =0.024), blood transfusion (yes) (OR=2.450, P =0.021), one-time consumables for surgery (or=1.000, P =0.022), number of total lymph nodes (OR=1.060, P =0.011) and number of positive lymph nodes (OR=1.054, P =0.029) were independent risk factors for early postoperative complications in TG, and nomogram model was constructed. The C-index of primary cohort, modeling cohort and validation cohort was 0.787, 0.754 and 0.912. The calibration curves showed good accuracy. CONCLUSION: This study used the indicators available before and during surgery to establish a nomogram model for early postoperative complications of total gastrectomy for gastric cancer, which found that linear stapler (LS), blood transfusion, one-time consumables for surgery, number of total lymph nodes and number of positive lymph nodes were factors.