AS160 controls eukaryotic cell cycle and proliferation by regulating the CDK inhibitor p21

TBC1D4 antagonizes RAB2A-mediated autophagic and endocytic pathways

Macroautophagic/autophagic and endocytic pathways play essential roles in maintaining homeostasis at different levels. It remains poorly understood how both pathways are coordinated and fine-tuned for proper lysosomal degradation of diverse cargoes. We and others recently identified a Golgi-resident RAB GTPase, RAB2A, as a positive regulator that controls both autophagic and endocytic pathways. In the current study, we report that TBC1D4 (TBC1 domain family member 4), a TBC domain-containing protein that plays essential roles in glucose homeostasis, suppresses RAB2A-mediated autophagic and endocytic pathways. TBC1D4 bound to RAB2A through its N-terminal PTB2 domain, which impaired RAB2A-mediated autophagy at the early stage by preventing ULK1 complex activation. During the late stage of autophagy, TBC1D4 impeded the association of RUBCNL/PACER and RAB2A with STX17 on autophagosomes by direct interaction with RUBCNL via its N-terminal PTB1 domain. Disruption of the autophagosomal trimeric complex containing RAB2A, RUBCNL and STX17 resulted in defective HOPS recruitment and eventually abortive autophagosome-lysosome fusion. Furthermore, TBC1D4 inhibited RAB2A-mediated endocytic degradation independent of RUBCNL. Therefore, TBC1D4 and RAB2A form a dual molecular switch to modulate autophagic and endocytic pathways. Importantly, hepatocyte- or adipocyte-specific tbc1d4 knockout in mice led to elevated autophagic flux and endocytic degradation and tissue damage. Together, this work establishes TBC1D4 as a critical molecular brake in autophagic and endocytic pathways, providing further mechanistic insights into how these pathways are intertwined both in vitro and in vivo.Abbreviations: ACTB: actin beta; ATG9: autophagy related 9; ATG14: autophagy related 14; ATG16L1: autophagy related 16 like 1; CLEM: correlative light electron microscopy; Ctrl: control; DMSO: dimethyl sulfoxide; EGF: epidermal growth factor; EGFR: epidermal growth factor receptor; FL: full length; GAP: GTPase-activating protein; GFP: green fluorescent protein; HOPS: homotypic fusion and protein sorting; IP: immunoprecipitation; KD: knockdown; KO: knockout; LAMP1: lysosomal associated membrane protein 1; MAP1LC3B/LC3B: microtubule associated protein 1 light chain 3 beta; OE: overexpression; PG: phagophore; PtdIns3K: class III phosphatidylinositol 3-kinase; SLC2A4/GLUT4: solute carrier family 2 member 4; SQSTM1/p62: sequestosome 1; RUBCNL/PACER: rubicon like autophagy enhancer; STX17: syntaxin 17; TAP: tandem affinity purification; TBA: total bile acid; TBC1D4: TBC1 domain family member 4; TUBA1B: tubulin alpha 1b; ULK1: unc-51 like autophagy activating kinase 1; VPS39: VPS39 subunit of HOPS complex; WB: western blot; WT: wild type.

Targeting a novel circITCH/miR-421/BTG1 axis is effective to suppress the malignant phenotypes in hepatocellular carcinoma (HCC) cells

Circular RNA-based competing endogenous RNA (ceRNA) networks contribute to the initiation and development of various types of cancer, including hepatocellular carcinoma (HCC). Although a novel circular RNA itchy E3 ubiquitin protein ligase (circITCH) is identified as a tumor suppressor in HCC, its detailed molecular mechanisms have not been fully delineated. The present study was designed to resolve this issue, and we firstly verified that circITCH suppressed the malignant phenotypes in HCC cells by regulating a novel miR-421/B-cell translocation gene 1 (BTG1) axis. Specifically, through performing the Real-Time qPCR analysis, we noticed that circITCH expression in HCC tumor tissues or cell lines were significantly lower than that in adjacent normal tissues or normal hepatocytes, and the expression levels of circITCH were negatively correlated with tumor size and TNM stage in HCC patients. Next, our functional experiments confirmed that overexpression of circITCH induced cell cycle arrest and apoptosis, and reduced cell viability and colony forming ability in Hep3B and Huh7 cells. Mechanically, bioinformatics analysis, RNA immunoprecipitation and luciferase reporter assay demonstrated that circITCH served as RNA sponges for miR-421 to elevate BTG1 levels in HCC cells. The rescuing experiments verified that upregulation of miR-421 promoted cell viability and colony formation, and reduced apoptosis, which were abrogated by overexpression of circITCH or BTG1. In conclusion, this study identified a novel circITCH/miR-421/BTG1 axis that restrained the development of HCC, and our findings provided novel biomarkers for the treatment of this disease.

Diversin upregulates the proliferative ability of colorectal cancer by inducing cell cycle proteins

Colorectal cancer (CRC) is a common gastrointestinal tumour with increasing incidence worldwide. However, the underlying molecular mechanism of CRC proliferation is not completely clear. Diversin，as an ankyrin repeat-containing protein, is upregulated in various solid tumours and accelerates cancer progression by promoting cell proliferation and increasing S phase fraction of cells. In this study, 71 CRC samples and corresponding adjacent tissue samples were included. The expression of diversin in tissues was verified via immunohistochemical analysis. The MTS assay and flow cytometry (FCM) was used to measure cell proliferation and cell cycle. Results of immunohistochemical analysis revealed that diversin was highly expressed in human CRC tissues and was significantly associated with tumour differentiation, clinical stage and lymph node metastasis. The analysis based on the CRC data from The Cancer Genome Atlas (TCGA) database showed that a high expression of diversin correlated with the poor prognosis of CRC. Results of the MTS assay indicated that the overexpression of diversin promoted the proliferation of CRC cells, while its downregulation had an inhibitory effect on CRC cell proliferation. FCM analysises presented that diversin increased the flux of the CRC cell cycle from G1 to S and regulated cycle-related proteins, namely, P21, P27, cyclin E, CDK2, cyclin D and CDK4. The results suggest that diversin contributes to CRC proliferation that involves the distribution of the cell cycle. In CRC tissues, the expression of diversin has closely related to the prognosis. The higher the expression levels of diversin, the worse the prognosis. In vitro, diversin could increase the proliferative ability of CRC cells through the G1-S checkpoint and JNK signalling pathway, confirming that diversin contributes to CRC development.

CRC-derived exosomes containing the RNA binding protein HuR promote lung cell proliferation by stabilizing c-Myc mRNA

HuR overexpression is related to poor survival in patients with colon cancer. HuR overexpression leads to stabilization of tumor-promoting mRNAs by binding to 3′UTR-resident AREs. Exosomes, nanosized lipid bilayer vesicles, mediate many steps in cancer progression. The potential role of exosomal HuR in colon cancer lung metastasis is unclear. HuR expression was assessed immunohistochemically in tumor tissue samples from 20 patients with metastatic or nonmetastatic colon cancer and colon cancer lung metastasis and benign lung disease samples from ten patients. Exosomes were isolated from HCT116 WT and HuR KO colon cancer cells, and uptake of PKH67- and PKH26-labeled exosomes by BEAS-2B cells was evaluated using fluorescence and confocal microscopy. C-Myc and p21protein and mRNA levels were measured by western blotting and RT-qPCR, respectively. In clinical patients, HuR overexpression was significantly enhanced in colon tissues of patients with lung metastasis. HuR expression was higher in lung tissue with metastasis of colonic origin than with benign lung disease. The effect of HuR-containing CRC exosomes compared to HuR-deficient exosomes on wound closure was observed as enhanced proliferation. BEAS-2B cell migration and invasion were enhanced after HuR-containing exosomes treatment. BEAS-2B cells showed similar uptake of PKH67 (HCT116 WT)- and PKH26 (HCT116 HuR KO)-labeled exosomes. Exosomal HuR stabilized c-Myc mRNA and downregulated p21 expression, leading to G1/S transition, in human bronchial epithelial cells. HuR overexpression is associated with lung metastasis in colon cancer patients. Exosomal HuR derived from colon cancer cells alter the biological effect on normal lung epithelial cells.

Clinical and genetic analyses of patients with lateralized overgrowth

Background

The genetic features and treatment strategies of lateralized overgrowth have been elusive. We performed this study to analyze the genetic characteristics and treatment results of propranolol- or alpelisib-treated patients with lateralized overgrowth.

Methods

Fifteen patients with lateralized overgrowth were involved. Clinical characteristics and whole-body magnetic resonance imaging (WB-MRI) findings were evaluated. Targeted exome sequencing with a gene panel of affected tissue and peripheral white blood cells was performed. Propranolol was administered and treatment results were evaluated. The PIK3CA inhibitor alpelisib was prescribed via a managed access program.

Results

The identified mutations were PIK3CA (n = 7), KRAS (n = 2), PTEN (n = 1), MAP2K3 (n = 1), GNAQ (n = 1), TBC1D4 (n = 1), and TEK (n = 1). Propranolol was prescribed in 12 patients, and 7 experienced mild improvement of symptoms. Alpelisib was prescribed in two patients with a PIK3CA mutation, and the reduction of proliferated masses after 1 year of treatment was proved by WB-MRI.

Conclusions

Targeted exome sequencing identified various genetic features of lateralized overgrowth. Propranolol could be applied as an adjuvant therapy for reducing vascular symptoms, but a PIK3CA inhibitor would be the primary therapeutic strategy for PIK3CA-related overgrowth syndrome.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12920-022-01362-1.

miR-421 promotes the viability of A549 lung cancer cells by targeting forkhead box O1

MicroRNA (miR)-421 has been reported to serve various important roles in numerous types of cancer, including neuroblastoma and gastric cancer. However, to the best of our knowledge, few reports have determined the role of miR-421 in lung cancer. The aim of the current study was to analyze the expression levels of miR-421 in A549 lung cancer cells, to determine the target gene of miR-421, and to investigate the function and mechanism of miR-421 in cellular cytotoxicity. miR-421 expression levels were analyzed in A549 lung cancer cells using reverse transcription-quantitative PCR, a MTT assay was performed to determine the effect of miR-421 on A549 cell cytotoxicity and the protein expression levels of forkhead box O1 (FOXO1) were determined via western blotting. The target gene of miR-421 was predicted and verified using TargetScan and a dual-luciferase reporter assay, respectively. The results revealed that miR-421 expression levels were significantly upregulated in A549 lung cancer cell lines compared with the normal cells (P<0.01). Additionally, it was discovered that miR-421 promoted A549 cell viability (P<0.01) compared with A549 transfected with negative control. miR-421 was also identified to bind to the 3′-untranslated region of FOXO1. In A549 cells transfected with miR-421-mimics, the expression levels of phosphorylated (p)-AKT, p-glycogen synthase kinase-3β, p-retinoblastoma and cyclin D1 were significantly upregulated (P<0.01), whereas the expression levels of FOXO1 and p21 were significantly downregulated (P<0.01) compared with the control group. In conclusion, the results of the present study suggested that miR-421 may promote the viability of A549 lung cancer cells by targeting FOXO1 and modulating cell cycle, indicating that targeting miR-421 and FOXO1 may represent future therapeutic strategies for the treatment of patients with lung cancer.

Neuroprotective effects of hesperidin against methotrexate-induced changes in neurogenesis and oxidative stress in the adult rat

Methotrexate (MTX) induces the formation of reactive oxygen species (ROS) and leads to neurotoxicity. The drug also negatively impacts neurogenesis and memory. Hesperidin (Hsd) is a major flavanoid with multiple beneficial pharmacological effects such as anti-oxidation, anti-inflammation, and neuroprotective effects. The aim of our study was to investigate the neuroprotective effects of Hsd against MTX-induced alterations in oxidative stress and neurogenesis. Sprague Dawley rats were divided into four groups: 1) a vehicle group, which received saline and propylene glycol, 2) an Hsd group, which was orally administered with Hsd (100 mg/kg) for 21 days, 3) an MTX group, which received MTX (75 mg/kg) by intravenous injection on days 8 and 15, and 4) an MTX + Hsd group, which received both MTX and Hsd. After treatment with MTX, p21-positive cells had increased significantly and doublecortin (DCX) expression in the hippocampus had decreased significantly. Treatment with MTX also increased malondialdehyde (MDA) in both the hippocampus and prefrontal cortex and decreased levels of brain-derived neurotropic factor (BDNF) and nuclear factor erythroid 2-related factor 2 (Nrf2) in the hippocampus and prefrontal cortex. Additionally, there were significant decreases in superoxide dismutase (SOD), glutathione peroxidase (GPx), and catalase (CAT) in the hippocampus and prefrontal cortex in the MTX group. However, co-treatment with Hsd ameliorated the negative effects of MTX on neurogenesis, oxidative stress, and antioxidant enzymes. These findings suggest that Hsd may be able to prevent neurotoxic effects of MTX by reducing oxidative stress and enhancing hippocampal neurogenesis.

RETRACTED: Brazilein induces apoptosis and G1/G0 phase cell cycle arrest by up-regulation of miR-133a in human vestibular schwannoma cells

This article has been retracted: please see Elsevier Policy on Article Withdrawal (http://www.elsevier.com/locate/withdrawalpolicy). This article has been retracted at the request of the Editor-in-Chief. Given the comments of Dr Elisabeth Bik regarding this article “... the Western blot bands in all 400+ papers are all very regularly spaced and have a smooth appearance in the shape of a dumbbell or tadpole, without any of the usual smudges or stains. All bands are placed on similar looking backgrounds, suggesting they were copy/pasted from other sources, or computer generated”, the journal requested the authors to provide the raw data. However, the authors were not able to fulfil this request and therefore the Editor-in-Chief decided to retract the article.

Novel dual-color drug screening model for GLUT4 translocation in adipocytes

Insulin-responsive glucose transporter type 4 (GLUT4) translocation plays a major role in controlling glucose uptake in adipose tissue and muscle, maintaining homeostasis and preventing hyperglycemia. Screening for chemicals enhancing GLUT4 translocation is an approach for identifying hits of drug development for type 2 diabetes. Here we developed a novel functional dual-color probe, pHluorin-GLUT4-mOrange2, and constructed 3T3-L1 adipocytes based screening system to simply and efficiently screen new compounds stimulating GLUT4 translocation. Based on this system, we successfully identified a few hits facilitating GLUT4 translocation. In conclusion, we developed an easy-to-apply dual color GLUT4 probe to monitor GLUT4 translocation in insulin-responsive cells, which could be alternatively employed to high-throughput screen compounds regulating GLUT4 translocation and glucose uptake, even to dissect GLTU4 approaching, docking and fusion with the plasma membrane (PM), and to reveal relevant molecular mechanisms involved in these steps as expected.

Astragalus polysaccharides decrease proliferation, migration, and invasion but increase apoptosis of human osteosarcoma cells by up-regulation of microRNA-133a

Osteosarcoma (OS) has a high incidence, malignity, and frequency of recurrence and metastasis. In this study, we aimed to explore the potential anti-cancer effects of Astragalus polysaccharides (APS) on human OS MG63 cells as well as underlying mechanisms. Viability of MG63 cells was assessed by CCK-8 assay to determine the adequate concentration of APS. Then, effects of APS on MG63 cell proliferation, cell cycle distribution, apoptosis, and migration and invasion were analyzed by BrdU incorporation, PI staining, flow cytometry, and transwell assays, respectively. The expression levels of proteins involved in these physiological processes were assessed by western blot analysis. Afterwards, miR-133a level in APS-treated cells was determined by qRT-PCR, and whether APS affected MG63 cells through regulation of miR-133a was determined. Finally, the activation of c-Jun N-terminal protein kinase (JNK) pathway was detected. We found that APS treatment suppressed the viability, proliferation, migration, and invasion of MG63 cells, as well as induced cell apoptosis. Moreover, APS enhanced the expression of miR-133a in MG63 cells. Knockdown of miR-133a reversed the APS treatment-induced MG63 cell proliferation, migration and invasion inhibition, as well as cell apoptosis. Furthermore, APS inactivated JNK pathway in MG63 cells. Knockdown of miR-133a reversed the APS treatment-induced inactivation of JNK pathway in MG63 cells. To conclude, APS repressed proliferation, migration, and invasion while induced apoptosis of OS MG63 cells by up-regulating miR-133a and then inactivating JNK pathway.

Lactobacillus casei Strain Shirota Enhances the In Vitro Antiproliferative Effect of Geniposide in Human Oral Squamous Carcinoma HSC-3 Cells

This study investigated the enhanced antiproliferative effect of Lactobacillus casei strain Shirota (LcS) on geniposide actions in human oral squamous carcinoma HSC-3 cells. An MTT assay, flow cytometry, qPCR assay, western blot and HPLC were used for this study. The concentration of 1.0 × 10⁶ CFU/mL of LcS had no effect on the HOK normal oral epithelial cells and HSC-3 cancer cells. The 25 and 50 µg/mL geniposide concentrations also had no impact on HOK normal oral epithelial cells, but they had remarkable inhibitory effects on the growth of HSC-3 cancer cells, which are enhanced in the presence of LcS. By the flow cytometry assay, the LcS-geniposide-H (1.0 × 10⁶ CFU/mL LcS and 50 µg/mL geniposide)-treated HSC-3 cancer cells had the largest number of cells undergoing apoptosis compared to cells treated with other combinationsand obviously more than cells treated with only geniposide-H (50 µg/mL geniposide). Geniposide-H could increase the mRNA and protein expressions of caspase-3, caspase-8, caspase-9, Bax, p53, p21, IκB-α, Fas, FasL, TIMP-1, and TIMP-2 as well as decrease those of Bcl-2, Bcl-xL, HIAP-1, HIAP-2, NF-κB, COX-2, iNOS, MMP-2, and MMP-9 compared to other groups of cells, and LcS further enhanced these changes, with results that are greater than for the cells treated with only a high concentration of geniposide. The results of this study show thatLcS enhanced the antiproliferative effect of geniposide in HSC-3 cancer cells.

Effects of three IL-15 variants on NCI-H446 cell proliferation and expression of cell cycle regulatory molecules

Interleukin 15 (IL-15) is a cytokine exhibiting antitumor characteristic similar to that of IL-2. However, in human tissues and cells, IL-15 expression and secretion is very limited, suggesting IL-15 functions mainly intracellularly. In the present study, we assessed the effects of transfecting NCI-H446 small cell lung cancer cells with genes encoding three IL-15 variants: prototypical IL-15, mature IL-15 peptide, and modified IL-15 in which the IL-2 signal peptide is substituted for the native signal peptide. NCI-H446 cells transfected with empty plasmid served as the control group. We found that IL-15 transfection effectively inhibited NCI-H446 cell proliferation and arrested cell cycle progression, with the modified IL-15 carrying the IL-2 signal peptide exerting the greatest effect. Consistent with those findings, expression each of the three IL-15 variants reduced growth of NCI-H446 xenograph tumors, and the modified IL-15 again showed the greatest effect. In addition, IL-15 expression led to down-regulation of the positive cell cycle regulators cyclin E and CDK2 and up-regulation of the negative cycle regulators p21 and Rb. These findings suggest IL-15 acts as a tumor suppressor that inhibits tumor cell proliferation by inducing cell cycle arrest.

Resveratrol enhances anticancer effects of paclitaxel in HepG2 human liver cancer cells

BACKGROUND

The aim of this in vitro study was to measure the enhanced anticancer effects of Res (resveratrol) on PA (paclitaxel) in HepG2 human liver cancer cells.

METHODS

The MTT (thiazolyl blue tetrazolium bromide, 3-(4,5-Dimethylthiazol-2-yl)-2,5-Diphenyltetrazolium Bromide), flow cytometry, qPCR (real-time quantitative polymerase chain reaction) and western blot assay were used for cells growth inhibitory effects, cells apoptosis (DNA content of sub-G1), mRNA and protein expressions, respectively.

RESULTS

The 10 μg/mL of Res had no growth inhibitory effect on Nthy-ori 3-1 normal cells or HepG2 cancer cells meanwhile the 5 or 10 μg/mL of PA also had no growth inhibitory effect on Nthy-ori 3-1 normal cells. Where as PA-L (5 μg/mL) and PA-H (10 μg/mL) had the growth inhibitory effects in HepG2 cancer cells, and Res increase these growth inhibitory effects. By flow cytometry experiment, after Res (5 μg/mL) + PA-H (10 μg/mL) treatment, the HepG2 cells showed the most apoptosis in cells as compared to other treatments groups, and after additionally treated with Res, both the apoptosis cells of two concentrations PA were raised. As PA raised it also raised the mRNA and protein expressions of caspase-3, caspase-8, caspase-9, Bax (Bcl-2 assaciated X protein), p53, p21, IκB-α (inhibitor of NF-κB alpha), Fas (factor associated suicide), FasL (factor associated suicide ligand), TIMP-1 (tissue inhibitor of metalloproteinases 1), TIMP-2 (tissue inhibitor of metalloproteinases 2) and decrease Bcl-2 (B cell leukemia 2), Bcl-xL (B cell leukemia extra large), HIAP-1 (cIAP-1, cellular inhibitor of apoptosis 1), HIAP-2 (cIAP-2, cellular inhibitor of apoptosis 2), NF-κB (nuclear factor kappa B), COX-2 (cyclooxygenase 2), iNOS (inducible nitric oxide synthase), MMP-2 (metalloproteinase 2), MMP-9 (metalloproteinase 9), EGF (epidermal growth factor), EGFR (epidermal growth factor receptor), VEGF (vascular endothelial growth factor), Fit-1 (VEGFR-1, vascular endothelial growth factor receptor 1). Meanwhile, the 5 μg/mL of Res could enhance these mRNA expressions changes as compared to the control cells.

CONCLUSION

From these results, we can conclude that Res could raise the anticancer effects of PA in HepG2 cells, Res could be used as a good sensitizing agent for PA.

Lactobacillus raises in vitro anticancer effect of geniposide in HSC-3 human oral squamous cell carcinoma cells

The present study determined the ability of the Lactobacillus rhamnosus GG strain (LGG) to enhance the anticancer effects of geniposide on HSC-3 human oral squamous carcinoma cells. LGG (1.0×10³ CFU/ml) on its own had no impact on human oral keratinocytes and HSC-3 cancer cells. Geniposide (25 or 50 µg/ml) had no impact on human oral keratinocytes, but exerted growth inhibitory effects on HSC-3 cancer cells, which were increased in the presence of LGG. Flow cytometric analysis and a nuclear staining assay with DAPI revealed that HSC-3 cancer cells treated with LGG-geniposide (1.0×10³ CFU/ml LGG and 50 µg/ml geniposide) had a higher apoptotic rate than cells in other treatment groups, particularly that treated with geniposide (50 µg/ml) only. Geniposide also increased the mRNA and protein expression of caspase-3, -8 and -9 as well as B-cell lymphoma 2 (Bcl-2)-associated X protein, p53, p21, inhibitor of nuclear factor-κB (NF-κB) α, Fas and Fas ligand, while decreasing Bcl-2, Bcl extra large protein, inhibitor of apoptosis-1 and -2, NF-κB, cyclooxigenase-2 and inducible nitric oxide synthase in HSC-3 cells, which was increased in the presence of LGG. These results indicated that LGG enhanced the anticancer effects of geniposide in HSC-3 cells.