OBJECTIVE: To investigate the effect of ANP32A silencing on invasion and migration of colon cancer cells and the influence of the activity of AKT signaling pathway on this effect. METHODS: Colorectal cancer HCT116 and SW480 were transfected with a small interfering RNA targeting ANP32A via a lentiviral vector. At 24, 48 and 72 h after the transfection, the changes in cell proliferation and AKT activity in the cells were detected using MTT assay and Western blotting, respectively. HCT116 and SW480 cells were treated with the AKT agonist SC79 or its inhibitor MK2206 for 24, 48, 72 and 96 h, and the changes in cell migration and invasion ability were analyzed using Transwell chamber assay and cell proliferation was assessed using MTT assay. The effects of SC79 and MK2206 on migration and invasion abilities of HCT116 and SW480 cells with or without ANP32A silencing were examined using wound healing and Transwell chamber assays, and the changes in the expression of metadherin (MTDH), a factor associated with cells invasion and migration, was detected with Western blotting. RESULTS: Lentivirus-mediated ANP32A silencing significantly down-regulated the activity of AKT and inhibited the proliferation of both HCT116 and SW480 cells (P < 0.01). The application of AKT inhibitor MK2206 obviously inhibited the proliferation, invasion and migration of the colorectal cancer cells (P < 0.05), while the AKT agonist SC79 significantly promoted the invasion and migration of the cells (P < 0.01). In HCT116 and SW480 cells with ANP32A silencing, treatment with MK2206 strongly enhanced the inhibitory effects of ANP32A silencing on cell invasion and migration (P < 0.05) and the expression of MTDH, while SC79 partially reversed these inhibitory effects (P < 0.01). CONCLUSION ANP32A silencing inhibits invasion and migration of colorectal cancer cells possibly by inhibiting the activation of the AKT signaling pathway.
Humans ; Proto-Oncogene Proteins c-akt ; Cell Proliferation ; Blotting, Western ; Cell Movement ; Colonic Neoplasms ; Membrane Proteins ; RNA-Binding Proteins/genetics* ; Nuclear Proteins

OBJECTIVE: To investigate the effects of LASS2/TMSG1 gene overexpression on proliferation and apoptosis of human lung cancer A549 cells and explore the possible mechanism. METHODS: We examined LASS2/TMSG1 expression level in a previously constructed A549 cell line overexpressing LASS2/TMSG1 using Western blotting. The proliferation and apoptosis of the cells were detected using colony-forming assay, CCK-8 assay, Hoechst/PI double staining and flow cytometry. Fourteen nude mice were randomized into 2 groups (n=7) to receive subcutaneous injection of A549 cells with or without LASS2/TMSG1 overexpression on the back of the neck, and the cell proliferation in vivo was observed. The expression levels of p38 MAPK protein and p-p38 MAPK protein in the xenografts were detected with Western blotting. ELISA was used to detect the levels of ceramide and p38 MAPK protein in cultured A549 cell supernatants and the xenografts in nude mice. RESULTS: Compared with the negative control cells, A549 cells with LASS2/TMSG1 overexpression had significantly lowered proliferation ability in vitro with increased early apoptosis rate (P < 0.05), and showed obvious growth inhibition after inoculation in nude mice(P < 0.05). Western blotting showed that in both cultured A549 cells and the xenografts in nude mice, LASS2/TMSG1 gene overexpression significantly increased the expression levels of p38 MAPK protein and p-p38 MAPK protein (P < 0.05); the results of ELISA also revealed significantly increased levels of ceramide and p38 MAPK protein in the cell supernatant andxenografts as well (P < 0.05). CONCLUSION Overexpression of LASS2/TMSG1 gene can significantly inhibit the proliferation and promote early apoptosis of human lung cancer A549 cells both in vitro and in vivo possibly by upregulating the expressions of ceramide and p38 MAPK protein to activate a signal transduction cascade.
Animals ; Humans ; Mice ; A549 Cells ; Apoptosis ; Cell Line, Tumor ; Cell Proliferation ; Lung Neoplasms ; Membrane Proteins/metabolism* ; Mice, Nude ; p38 Mitogen-Activated Protein Kinases/metabolism* ; Signal Transduction ; Tumor Suppressor Proteins/metabolism*

OBJECTIVE: To screen the differentially expressed long non-coding RNAs (lncRNAs) in non-small cell lung cancer (NSCLC) cells with acquired resistance to osimertinib and explore their roles in drug resistance of the cells. METHODS: The cell lines H1975_OR and HCC827_OR with acquired osimertinib resistance were derived from their osimertinib-sensitive parental NSCLC cell lines H1975 and HCC827, respectively, and their sensitivity to osimertinib was assessed with CCK-8 assay, clone formation assay and flow cytometry. RNA sequencing (RNA-seq) and real-time quantitative PCR (qPCR) were used to screen the differentially expressed lncRNAs in osimertinib-resistant cells. The role of the identified lncRNA in osimertinib resistance was explored using CCK-8, clone formation and Transwell assays, and its subcellular localization and downstream targets were analyzed by nucleoplasmic separation, bioinformatics analysis and qPCR. RESULTS: The resistance index of H1975_OR and HCC827_OR cells to osimertinib was 598.70 and 428.82, respectively (P < 0.001), and the two cell lines showed significantly increased proliferation and colony-forming abilities with decreased apoptosis (P < 0.01). RNA-seq identified 34 differentially expressed lncRNAs in osimertinib-resistant cells, and among them lnc-TMEM132D-AS1 showed the highest increase of expression after acquired osimertinib resistance (P < 0.01). Analysis of the TCGA database suggested that the level of lnc-TMEM132D-AS1 was significantly higher in NSCLC than in adjacent tissues (P < 0.001), and its high expression was associated with a poor prognosis of the patients. In osimertinib-sensitive cells, overexpression of Lnc-TMEM132D-AS1 obviously promoted cell proliferation, colony formation and migration (P < 0.05), while Lnc-TMEM132D-AS1 knockdown partially restored osimertinib sensitivity of the resistant cells (P < 0.01). Lnc-TMEM132D-AS1 was localized mainly in the cytoplasm, and bioinformatics analysis suggested that hsa-miR-766-5p was its candidate target, and their expression levels were inversely correlated. The target mRNAs of hsa-miR-766-5p were mainly enriched in the Ras signaling pathway. CONCLUSION The expression of lnc-TMEM132D-AS1 is significantly upregulated in NSCLC cells with acquired osimertinib resistance, and may serve as a potential biomarker and therapeutic target for osimertinibresistant NSCLC.
Humans ; Carcinoma, Non-Small-Cell Lung/metabolism* ; Lung Neoplasms/genetics* ; RNA, Long Noncoding/metabolism* ; Sincalide/metabolism* ; Cell Line, Tumor ; Cell Proliferation/genetics* ; Cell Movement ; MicroRNAs/genetics* ; Gene Expression Regulation, Neoplastic ; Membrane Proteins/metabolism*

PiT2 is an inorganic phosphate (Pi) transporter whose mutations are linked to primary familial brain calcification (PFBC). PiT2 mainly consists of two ProDom (PD) domains and a large intracellular loop region (loop7). The PD domains are crucial for the Pi transport, but the role of PiT2-loop7 remains unclear. In PFBC patients, mutations in PiT2-loop7 are mainly nonsense or frameshift mutations that probably cause PFBC due to C-PD1131 deletion. To date, six missense mutations have been identified in PiT2-loop7; however, the mechanisms by which these mutations cause PFBC are poorly understood. Here, we found that the p.T390A and p.S434W mutations in PiT2-loop7 decreased the Pi transport activity and cell surface levels of PiT2. Furthermore, we showed that these two mutations attenuated its membrane localization by affecting adenosine monophosphate-activated protein kinase (AMPK)- or protein kinase B (AKT)-mediated PiT2 phosphorylation. In contrast, the p.S121C and p.S601W mutations in the PD domains did not affect PiT2 phosphorylation but rather impaired its substrate-binding abilities. These results suggested that missense mutations in PiT2-loop7 can cause Pi dyshomeostasis by affecting the phosphorylation-regulated cell-surface localization of PiT2. This study helps understand the pathogenesis of PFBC caused by PiT2-loop7 missense mutations and indicates that increasing the phosphorylation levels of PiT2-loop7 could be a promising strategy for developing PFBC therapies.
Humans ; Cell Membrane ; Mutation, Missense ; Phosphates/metabolism* ; Sodium-Phosphate Cotransporter Proteins, Type III/genetics*

NDFIP1 has been previously reported as a tumor suppressor in multiple solid tumors, but the function of NDFIP1 in NSCLC and the underlying mechanism are still unknown. Besides, the WW domain containing proteins can be recognized by NDFIP1, resulted in the loading of the target proteins into exosomes. However, whether WW domain-containing transcription regulator 1 (WWTR1, also known as TAZ) can be packaged into exosomes by NDFIP1 and if so, whether the release of this oncogenic protein via exosomes has an effect on tumor development has not been investigated to any extent. Here, we first found that NDFIP1 was low expressed in NSCLC samples and cell lines, which is associated with shorter OS. Then, we confirmed the interaction between TAZ and NDFIP1, and the existence of TAZ in exosomes, which requires NDFIP1. Critically, knockout of NDFIP1 led to TAZ accumulation with no change in its mRNA level and degradation rate. And the cellular TAZ level could be altered by exosome secretion. Furthermore, NDFIP1 inhibited proliferation in vitro and in vivo, and silencing TAZ eliminated the increase of proliferation caused by NDFIP1 knockout. Moreover, TAZ was negatively correlated with NDFIP1 in subcutaneous xenograft model and clinical samples, and the serum exosomal TAZ level was lower in NSCLC patients. In summary, our data uncover a new tumor suppressor, NDFIP1 in NSCLC, and a new exosome-related regulatory mechanism of TAZ.
Humans ; Carcinoma, Non-Small-Cell Lung/metabolism* ; Carrier Proteins/metabolism* ; Cell Line ; Cell Proliferation ; Exosomes/metabolism* ; Lung Neoplasms/genetics* ; Membrane Proteins/metabolism* ; Transcriptional Coactivator with PDZ-Binding Motif Proteins/metabolism*

OBJECTIVE: To investigate the clinical significance of SFRP1 gene and its methylation in childhood acute lymphoblastic leukemia (ALL) . METHODS: Methylation-specific PCR (MSP) was used to detect the methylation status of SFRP1 gene in bone marrow mononuclear cells of 43 children with newly diagnosed ALL before chemotherapy (primary group) and when the bone marrow reached complete remission d 46 after induction of remission chemotherapy (remission group), the expression of SFRP1 mRNA was detected by quantitative real-time polymerase chain reaction (qRT-PCR), the expression of SFRP1 protein was detected by Western blot, and clinical data of children were collected, the clinical significance of SFRP1 gene methylation in children with ALL was analyze. RESULTS: The positive rate of SFRP1 gene promoter methylation in the primary group (44.19%) was significantly higher than that in the remission group (11.63%) (χ2=11.328, P<0.05). The relative expression levels of SFRP1 mRNA and protein in bone marrow mononuclear cells of children in the primary group were significantly lower than those in the remission group (P<0.05). Promoter methylation of SFRP1 gene was associated with risk level (χ2=15.613, P=0.000) and survival of children (χ2=6.561, P=0.010) in the primary group, children with SFRP1 hypermethylation had significantly increased risk and shortened event-free survival time, but no significant difference in other clinical data. CONCLUSION Hypermethylation of SFRP1 gene promoter may be involved in the development of childhood ALL, and its hypermethylation may be associated with poor prognosis.
Child ; Humans ; Clinical Relevance ; DNA Methylation ; Precursor Cell Lymphoblastic Leukemia-Lymphoma/genetics* ; Bone Marrow/metabolism* ; RNA, Messenger/metabolism* ; Membrane Proteins/genetics* ; Intercellular Signaling Peptides and Proteins/metabolism*

OBJECTIVE: To investigate the mechanism of drug reversing resistance of Agaricus blazei extract FA-2-b-β on T cell acute lymphoblastic leukemia (T-ALL) cell lines. METHODS: Cell proliferation was detected by CCK-8 assay; the apoptosis, cell cycle mitochondrial membrane potential, and intracellular rhodamine accumulation were detected by flow cytometry, and apoptosis-related gene and protein expression were detected by qPCR and Western blot; the membrane surface protein MDR1 was observed by immunofluorescence microscopy. RESULTS: Different concentrations of FA-2-b-β significantly inhibited proliferation and induced apoptosis of CCRF-CEM and CEM/C1 (P<0.05), and CCRF-CEM cell cycle were arrested at S phase, and CEM/C1 cells were arrested at G₀/G₁ phase. Western blot and qPCR results show that FA-2-b-β inhibited ABCB1、ABCG2、CTNNB、MYC and BCL-2 expression, but upregulated Bax expression. In addition, FA-2-b-β reversed the resistance characteristics of CEM/C1 drug-resistance cells, which decreased mitochondrial membrane potential, and significantly increased the intracellular rhodamine accumulation, and weakening of the expression of the membrane surface protein MDR1. With the Wnt/β-catenin inhibitor (ICG001), the process was further intensified. CONCLUSION Agaricus Blazei Extract FA-2-b-β inhibits cell proliferation, promotes apoptosis, regulates the cell cycle, reduces mitochondrial energy supply, and down-regulate MDR1 expression to reverse the resistance of CEM/C1, which all suggest it is through regulating the Wnt signaling pathway in T-ALL.
Humans ; Precursor T-Cell Lymphoblastic Leukemia-Lymphoma ; Wnt Signaling Pathway ; Precursor Cell Lymphoblastic Leukemia-Lymphoma/metabolism* ; Apoptosis ; Drug Resistance, Multiple ; Membrane Proteins ; Cell Line, Tumor ; Cell Proliferation

Cancer stem cell-like cells (CSCs) play an integral role in the heterogeneity, metastasis, and treatment resistance of head and neck squamous cell carcinoma (HNSCC) due to their high tumor initiation capacity and plasticity. Here, we identified a candidate gene named LIMP-2 as a novel therapeutic target regulating HNSCC progression and CSC properties. The high expression of LIMP-2 in HNSCC patients suggested a poor prognosis and potential immunotherapy resistance. Functionally, LIMP-2 can facilitate autolysosome formation to promote autophagic flux. LIMP-2 knockdown inhibits autophagic flux and reduces the tumorigenic ability of HNSCC. Further mechanistic studies suggest that enhanced autophagy helps HNSCC maintain stemness and promotes degradation of GSK3β, which in turn facilitates nuclear translocation of β-catenin and transcription of downstream target genes. In conclusion, this study reveals LIMP-2 as a novel prospective therapeutic target for HNSCC and provides evidence for a link between autophagy, CSC, and immunotherapy resistance.
Humans ; Autophagy ; Carcinoma, Squamous Cell/pathology* ; Cell Line, Tumor ; Glycogen Synthase Kinase 3 beta/metabolism* ; Head and Neck Neoplasms/pathology* ; Neoplastic Stem Cells/pathology* ; Squamous Cell Carcinoma of Head and Neck/pathology* ; Lysosome-Associated Membrane Glycoproteins

Melanoma is the most aggressive cutaneous tumor. Neuropilin and tolloid-like 2 (NETO2) is closely related to tumorigenesis. However, the functional significance of NETO2 in melanoma progression remains unclear. Herein, we found that NETO2 expression was augmented in melanoma clinical tissues and associated with poor prognosis in melanoma patients. Disrupting NETO2 expression markedly inhibited melanoma proliferation, malignant growth, migration, and invasion by downregulating the levels of calcium ions (Ca²⁺) and the expression of key genes involved in the calcium signaling pathway. By contrast, NETO2 overexpression had the opposite effects. Importantly, pharmacological inhibition of CaMKII/CREB activity with the CaMKII inhibitor KN93 suppressed NETO2-induced proliferation and melanoma metastasis. Overall, this study uncovered the crucial role of NETO2-mediated regulation in melanoma progression, indicating that targeting NETO2 may effectively improve melanoma treatment.
Humans ; Calcium-Calmodulin-Dependent Protein Kinase Type 2/metabolism* ; Cell Line, Tumor ; Cell Proliferation ; Melanoma/genetics* ; Membrane Proteins/genetics* ; Phosphorylation ; Signal Transduction

Platycodon grandiflorum (Jacq.) A. DC. is a famous medicinal plant commonly used in East Asia. Triterpene saponins isolated from P. grandiflorum are the main biologically active compounds, among which polygalacin D (PGD) has been reported to be an anti-tumor agent. However, its anti-tumor mechanism against hepatocellular carcinoma is unknown. This study aimed to explore the inhibitory effect of PGD in hepatocellular carcinoma cells and related mechanisms of action. We found that PGD exerted significant inhibitory effect on hepatocellular carcinoma cells through apoptosis and autophagy. Analysis of the expression of apoptosis-related proteins and autophagy-related proteins revealed that this phenomenon was attributed to the mitochondrial apoptosis and mitophagy pathways. Subsequently, using specific inhibitors, we found that apoptosis and autophagy had mutually reinforcing effects. In addition, further analysis of autophagy showed that PGD induced mitophagy by increasing BCL2 interacting protein 3 like (BNIP3L) levels.In vivo experiments demonstrated that PGD significantly inhibited tumor growth and increased the levels of apoptosis and autophagy in tumors. Overall, our findings showed that PGD induced cell death of hepatocellular carcinoma cells primarily through mitochondrial apoptosis and mitophagy pathways. Therefore, PGD can be used as an apoptosis and autophagy agonist in the research and development of antitumor agents.
Humans ; Mitophagy ; Carcinoma, Hepatocellular/pathology* ; Liver Neoplasms/pathology* ; Cell Line ; Autophagy ; Apoptosis ; Membrane Proteins ; Proto-Oncogene Proteins/genetics* ; Tumor Suppressor Proteins/pharmacology*