miR-134 regulates cisplatin resistance of human lung adenocarcinoma cells

AIM: To investigate the roles of microRNA-134 (miR-134) in the cisplatin resistance of lung adenocarcinoma cells. METHODS: miRNA microarray was applied to compare the miRNA expression profile between A549/CDDP and A549 cells. Real-time PCR was used to confirm the expression of miR-134. miR-134 mimics and inhibitors were transfected into A549/CDDP and A549 cells, respectively. MTT assay was used to detect the sensitivity of lung cancer cells to cisplatin. Western blot was applied to test whether miR-134 regulated forkhead box protein M1 (FOXM1) and multidrug-associated protein 1 (MRP1) expression. RESULTS: Based on the data of miRNA microarray, 13 miRNAs were found to be differentially expressed in A549/CDDP cells compared with A549 cells, among which miR-134 was the most significantly down-regulated one. Compared with control group, A549/CDDP cells transfected with miR-134 mimics showed greatly enhanced sensitivity to cisplatin as indicated by IC₅₀ values (P<0.01). In contrast, suppression of the miR-134 level in the A549 cells resulted in a decreased sensitivity to cisplatin (P<0.01). FOXM1 siRNA down-regulated the protein levels of FOXM1. A549/CDDP cells transfected with si-FOXM1 showed enhanced sensitivity to cisplatin (P<0.01). In addition, the result of Western blot showed that miR-134 repressed MRP1 protein expression. CONCLUSION: miR-134 effectively increases the sensitivity of lung adenocarcinoma cells to cisplatin, and this effect of miR-134 may be partly due to its regulation of FOXM1 and MRP1 expression.     

Effect of HMGB2 on cell cycle and proliferation of lung adenocarcinoma

AIM: To investigate the effect of high-mobility group protein B2 (HMGB2) on cell cycle and proliferation of lung adenocarcinoma cells. METHODS: Cancer RNA-Seq Nexus (CRN) was used to analyze HMGB2 expression in lung adenocarcinoma tissues. OncoLnc was used to analyze the correlation between HMGB2 and prognosis of lung adenocarcinoma patients. Cancer Single-cell State Atlas (CancerSEA) was used to analyze the correlation between HMGB2 and 14 kinds of functional states of lung adenocarcinoma. siRNA was used to inhibit HMGB2 expression in human lung adenocarcinoma A549 cells. The silencing effects were verified by real-time PCR and Western blot, and the cell proliferation was detected by CCK8 and EdU assays. RESULTS: HMGB2 was over-expressed in the lung adenocarcinoma tissues. The overall survival of the patients with lung adenocarcinoma in HMGB2 high expression group was significantly lower than that of the patients with low expression of HMGB2 (log-rank test P=0.017 3). HMGB2 expression was positively correlated with cell cycle and proliferation of lung adenocarcinoma cells. The viability and proliferation ability of A549 cells after HMGB2 expression knock-down were significantly reduced (P < 0.05). CONCLUSION: The expression of HMGB2 is positively correlated with the cell cycle and proliferation of lung adenocarcinoma, and it can be used as a potential marker for evaluating the prognosis and therapeutic target of patients with lung adenocarcinoma.     

Significance of TRPM8 protein expression in lung adenocarcinoma

AIM To investigate the significance of transient receptor potential cation channel subfamily M member 8 （TRPM8） protein expression in lung adenocarcinoma. METHODS The tumor samples from 112 cases of patients with lung adenocarcinoma were collected in our hospital， and 4~5 years of follow-up was conducted. The protein expression of TRPM8 was analyzed by immunohistochemical staining， and the correlations between the TRPM8 protein expression and the clinical characteristics including prognosis of the patients with lung adenocarcinoma were investigated. After TRPM8 protein expression was up-regulated in A549 lung adenocarcinoma cells by lentiviral infection， the proliferation of A549 cells was analyzed by CCK-8 assay and colony formation assay， the cell cycle and apoptosis were analyzed by flow cytometry， and the migration and invasion abilities of the cells were measured by scratch experiment and Transwell assay. The TRPM8 protein expression was stably up-regulated in H1299 cells by lentiviral infection， and then the left and right buttocks of the immunodeficient mice were subcutaneously injected with empty vector control cells and TRPM8-overexpressing cells， respectively. The effects of TRPM8 on the growth of H1299 cell-derived xenograft tumor in immunodeficient mice were evaluated. RESULTS The 4~5-year survival rate in the patients with high TRPM8 protein expression was significantly higher than that in the patients with low expression of TRPM8 protein （P=0.017）. The tumor maximum diameter in the patients with high TRPM8 protein expression was significantly smaller than that in the patients with low TRPM8 protein expression （P=0.028）. The viability， the number of colonies and the migration and invasion abilities of TRPM8-overexpressing A549 cells were significantly decreased as compared with empty vector and parental cells （P<0.01）. The results of flow cytometry analysis showed that the proportion of A549 cells at S stage was significantly increased in TRPM8 overexpression group as compared with empty vector group （P<0.01）. The growth rate and the weight of TRPM8-overexpressing H1299 cell-derived xenograft tumor in immunodeficient mice were significantly lower than those in empty vector group （P<0.01）. CONCLUSION TPRM8 is a tumor suppressor in lung adenocarcinoma， and low expression of TRPM8 protein was a poor prognositic indicator of patients with lung adenocarcinoma.     

Clinical significance and prognostic value of β-catenin expression in colonic adenocarcinoma

AIM: To observe the expression of β-catenin in colonic adenocarcinoma and to investigate its clinical significance and prognostic value. METHODS: The integrated clinical and follow-up data of 52 patients, who were undergone radical operation, were retrospectively analyzed from June 2000 to June 2004 in our hospital. The paraffin-embedded tissues of 52 colonic adenocarcinoma specimens and 20 cases of normal paraneoplastic colonic mucous tissues were detected for β-catenin expression by immunohistochemical method. The relationships between β-catenin and clinical variables and prognostic value were statistically analyzed. RESULTS: β-catenin was normally expressed in all 20 normal cases. In the cases of colonic adenocarcinoma, the abnormal expression rate of β-catenin was 71%. The abnormal expression of β-catenin did not correlated with gender, age, histological differentiation and blood CEA (P>0.05), but it was correlated with lymph node metastasis and clinical stage (P<0.05). The abnormal expression of β-catenin were also correlated with the postoperative survive time (P<0.05). CONCLUSION: The abnormal expression of β-catenin is correlated with the lymph node metastasis and clinical stage, and the abnormal expression is an important adverse prognostic factor for survival in the patients with colonic adenocarcinoma. β-catenin may be a molecular prognostic marker in the patients with colonic adenocarcinoma.     

Role of BAG2 gene in A549 cell proliferation and its clinical implications

AIM: To investigate the role of Bcl-2-associated athanogene 2 (BAG2) in the proliferation of human lung adenocarcinoma A549 cells and its clinical implications. METHODS: The abundance of BAG2 protein in A549 and lung bronchial epithelium (HBE) cells were measured by Western blot. After down-regulation of BAG2 by transfection of siRNA in A549 cells, the expression of cell proliferation and cell cycle related proteins were detected by CFSE assay, WST-1 assay and Western blot, respectively. Moreover, the expression of BAG2 in cDNA array which contained 10 pairs of lung cancer and adjacent tissue was verified. Meanwhile, BAG2 expression in GEO database, which included the human lung cancer and adjacent tissue microarray data was analyzed. The prognosis power of BAG2 was evaluated by the Kaplan-Meier survival curve analysis. RESULTS: BAG2 had remarkably higher expression level in A549 cells than that in HBE cells. Knockdown of BAG2 resulted in significantly inhibition of proliferation in A549 cells, accompany with the significantly down-regulation of cyclin B1 and cyclin E1. BAG2 was over-expressed in the lung cancer tissues, as compared with the adjacent normal tissues. Kaplan-Meier plotter and cDNA microarray results showed that patients with higher BAG2 expression were significantly associated with poorer survival. CONCLUSION: The BAG2 gene tends to regulate A549 cells proliferation via cyclin B1 and cyclin E1. BAG2 has significantly prognostic power on the survival of lung cancer patients.     

Effect of luteolin on TGF-β1-induced epithelial-mesenchymal transition in lung cancer A549 cells

AIM:To investigate the effects of luteolin on the invasion and epithelial-mesenchymal transition (EMT) induced by transforming growth factor-β1 (TGF-β1) in lung cancer A549 cells. METHODS:The effect of luteolin at 5, 10, 20, 40, 80 and 160 μmol/L on the viability of A549 cells was measured by MTT assay. The invasion ability was analyzed by Transwell method. The morphological changes of the A549 cells were observed under microscope.The protein expression of E-cadherin and vimentin in the A549 cells were determined by Western blot. RESULTS:The viability of the A549 cells was significantly inhibited by luteolin in a dose-time dependent manner (P<0.05). The IC₅₀ of luteolin for the A549 cells (24 h) was 68.79 μmol/L, while that (48 h) was 47.86 μmol/L. TGF-β1 induced morphological alteration of the A549 cells from epithelial to mesenchymal forms. Luteolin significantly inhibited TGF-β1-induced invasion of the A549 cells (P<0.01). The protein expression of E-cadherin was significantly down-regulated and the protein expression of vimentin was significantly up-regulated in the presence of TGF-β1 at 5 μg/L (P<0.01). However, luteolin reversed TGF-β1-induced EMT, up-regulation of E-cadherin and down-regulation of vimentin (P<0.01). CONCLUSION:Lu-teolin reverses TGF-β1-induced EMT in the lung cancer A549 cells.     

miR-10b promotes high glucose-stimulated epithelial-mesenchymal transition of renal tubular epithelial cells by repressing KLF10 expression

AIM:To explore the effect and the underlying mechanisms of microRNA-10b (miR-10b) on high glucose-stimulated epithelial-mesenchymal transition (EMT) of renal tubular epithelial cells. METHODS:The expression level of miR-10b was examined by RT-qPCR in the kidney tissues of the type 2 diabetes patients with kidney fibrosis. The EMT model of HK-2 cells was induced by high glucose stimulation and the miR-10b expression in the process was detected by RT-qPCR. The morphological changes of the HK-2 cells were observed using a microscope. EMT markers, such as fibronectin and N-cadherin, were examined by Western blot. The online database predicted that the 3'-UTR of KLF10 bound to miR-10b and their direct interaction was confirmed by dual luciferase report assay. RESULTS:Compared with the para-carcinoma normal tissues, the expression level of miR-10b was up-regulated in the tissues of type 2 diabetes patients with kidney fibrosis (P<0.01). In high glucose-stimulated HK-2 cells, the expression level of miR-10b was increased in a time-dependent manner (P<0.01). miR-10b inhibitor reversed the morphological changes and the increases expression of the EMT markers including fibronectin, SLUG, N-cadherin and SNAI1 induced by high glucose stimulation. Online database showed miR-10b was able to bind with the 3'-UTR in the promoter region of KLF10, thus negatively regulating its expression. Meanwhile, over-expression of KLF10 inhibited the EMT induced by high glucose. Inhibition of TGF-β/Smad3 activation was observed during the process of KLF10-repressed EMT. CONCLUSION:miR-10b promotes high glucose-stimulated epithelial-mesenchymal transition of renal tubular epithelial cells may through repressing KLF10 expression.     

Expression of miRNA-181a in human lung adenocarcinoma cells and its effect on cell function

AIM: To study the expression of microRNA (miRNA)-181a in different human lung adenocarcinoma cell lines, and to investigate the effect of miRNA-181a on cell function and its mechanism in human lung adenocarcinoma drug resistant cell A549/DDP. METHODS: Real-time PCR was used to detect the expression of miRNA-181a in BEAS-2B cells, A549 cells and A549/DDP cells. The A549/DDP cells were transfected with pGenesil-miRNA-181a eukaryotic expression plasmid. At the same time, the untransfection group and negative transfection group were also set up. The expression of miRNA-181a, cell viability, cell growth inhibition and apoptosis rate during cis-diamminedichloroplatinum (DDP) treatment, cell cycle, cell invasion, the protein expression of miRNA-181a target genes bcl-2 and p53 in the A549/DDP cells were determined by real-time fluorescence quantitative PCR, MTT assay, flow cytometry, Transwell method and Western blot, respectivly. RESULTS: The expression of miRNA-181a in A549 cells and A549/DDP cells was significantly lower than that in BEAS-2B cells, and the lowest expression level was observed in A549/DDP cells (P<0.05). The expression of miRNA-181a in A549/DDP cells was significantly increased after transfection with pGenesil-miRNA-181a (P<0.05). The cell viability, cell cycle and invasion ability of the A549/DDP cells were inhibited after miRNA-181a transfection (P<0.05). The cell growth inhibition rate and apoptotic rate of the A549/DDP cells were increased (P<0.05). The expression of Bcl-2 was reduced, but the expression of P53 was increased after transfection with miRNA-181a in A549/DDP cells (P<0.05). CONCLUSION: miRNA-181a may be correlated with the development of human lung adenocarcinoma. miRNA-181a can serve as a new target for treatment of lung cancer.     

Effects of marrow stromal cell-mediated microenvironment on human lung adenocarcinoma A549 cells

AIM: To investigate the effects of marrow stromal cell line HS-5 on human lung adenocarcinoma A549 cells in the tumor microenvironment. METHODS: The effects of HS-5 cell-conditioned medium (HS-5-CM) on the viability and migration ability of A549 cells were detected by MTT assay and wound-healing assay. After treatment with HS-5-CM, the expression of CX3C chemokine receptor 1 (CX3CR1) at mRNA level in the A549 cells was examined by qPCR. The protein levels of p-ERK and ERK in the A549 cells treated with MAPK/ERK pathway inhibitor U0126 were observed by Western blot, the migration ability of the A549 cells was measured by wound-healing assay, and the protein expression of CX3CR1 was determined by Western blot. RESULTS: HS-5-CM promoted the viability and migration ability of the A549 cells (P<0.01). The expression of CX3CR1 at mRNA level in the A549 cells was increased after treatment with HS-5-CM. MAPK/ERK inhibitor U0126 inhibited the activation of MAPK/ERK signaling pathway (P<0.01), and reduced the migration ability (P<0.01) and the expression of CX3CR1 (P<0.05) in the A549 cells. CONCLUSION: HS-5-CM significantly promotes the A549 cell viability and migration ability. Activation of MAPK/ERK signaling pathway and the expression of CX3CR1 may play a important role in this process.     

Effect of IL-8 on mitochondrial fusion and fission gene expression in human lung adenocarcinoma cell line A549 during cell migration

AIM: To investigate the changes of migration of lung adenocarcinoma cells promoted by IL-8 and the inner and outer mitochondrial membrane dynamic changes during this process.METHODS: Human lung adenocarcinoma cell line A549 was divided into control group and IL-8 group. Cell migration was analyzed by scratch detection and Transwell assay. The secretion of endogenous IL-8 was detected by ELISA. The protein levels of mitochondrial cytochrome C (Cyt C) and mitochondrial outer membrane protein Tom20 was detected by Western blot. The mRNA expression of mitochondrial fusion genes Mfn1, Mfn2 and OPA1 and fission genes Fis1, Drp1 and MTP18 was detected by RT-PCR. The morphological changes of mitochondria were observed by MitoTracker Red CMXRos dye staining and confocal microscopy.RESULTS: The migratory rate of A549 cells and endogenous secretion of IL-8 in A549 cells were higher than those in SPC-A-1 cells. The migratory rate of A549 cells was improved by IL-8 in a time-dependent manner. Compared with control group, the Tom20 protein expression was increased (P<0.05), and the Cyt C protein expression was decreased (P<0.05). The expression of mitochondrial outer membrane fusion genes Mfn1 and Mfn2 was increased (P<0.05), and the expression of mitochondrial inner membrane fusion gene OPA1 was decreased (P<0.05). The expression of fission genes Drp1 and MTP18 were decreased (P<0.05), while the expression of Fis1 was no change (P>0.05). Under confocal microscope, the punctate aggregates in the mitochondria of the A549 cells treated with IL-8 were observed.CONCLUSION: The migratory rate of A549 cells is increased by IL-8, which is related to the changes of mitochondrial fusion genes and the fission genes.     

Knock-down of NEDD1 expression inhibits lung adenocarcinoma cell proliferation and migration

AIM: To explore the role of neural precursor cell expression developmentally down-regulated protein 1 (NEDD1) in the development and progression of lung cancer. METHODS: The differences of NEDD1 expression levels between lung cancer tissues and tumor-adjacent tissues were analyzed by the method of immunohistochemistry and TCGA database. Kaplan-Meier curve was used to analyze the correlation between lung cancer prognosis and the expression level of NEDD1. The proliferation of A549 cells was tested by plate colony formation experiment after knock-down of NEDD1 expression. The apoptosis rate and cell cycle distribution were examined by flow cytometry. The migration ability of the A549 cells was detected by Transwell assay. The protein levels of cell cycle-related molecules were determined by Western blot. Database analysis was performed to evaluate the relationship between the expression of NEDD1 and cyclin-dependent kinases 2 (CDK2). RESULTS: Compared with the tumor-adjacent tissues, the expression level of NEDD1 in the lung cancer tissues was increased, so as the database analysis, and the higher expression of NEDD1 showed a poorer prognosis. Under light microscope, the A549 cells showed a low proliferation rate after silencing the NEDD1 expression, and the colony formation ability of the cells was also reduced; knock-down of NEDD1 expression induced the apoptosis and inhibited the cell migration; knock-down of NEDD1 expression blocked the cells in G₁/S phase, and the protein levels of p-Rb and cyclinD1 were decreased, while the protein levels of p-Chk1, p-Chk2 and p-p53 were increased (P<0.05). A positive correlation between the expression of NEDD1 and CDK2 was noted by database analysis. CONCLUSION: NEDD1 plays an crucial role in promoting cell proliferation via inhibiting apoptosis and accelerating cell cycle, high expression of NEDD1 in lung adenocarcinoma tissue is related to poor prognosis, thus NEDD1 may be used as a candidate marker molecule for the diagnosis and prognosis of lung cancer.     

Abnormalities of miR-21 expression in human breast cancer is associated with distinctive pathologic features and shortened postoperative survival

AIM: To investigate the potential relevance of miR-21 expression level to clinicopathological characteristics and patient survival. METHODS: 113 BRCA cases with more then 5 years fallow-up data were selected. Total RNA from formalin-fixed paraffin-embedded (FFPE) tissues of 113 breast cancer (BRCA) and normal adjacent tissues (NATs) were isolated for miR-21 quantitative analysis by real-time RT-PCR. RESULTS: The miR-21 expression levels in BRCA were significantly higher than those in NATs (P<0.01) with average up-regulated level of 1.74 ± 0.48. Interestingly, high level expression of miR-21 was significantly correlated with advanced clinical stage (P<0.01), lymph node metastasis (P<0.01), and shorter survival of the patients ［hazard ratio (HR)=5.476, P<0.01］. Multivariate Cox regression analysis revealed that miR-21 was one of independent prognostic impacts (HR=4.133, P<0.01) on BRCA. CONCLUSION: Over-expression of miR-21 is associated with poor prognosis of BRCA and may serve as an independent prognostic marker for BRCA.     

lncRNA TTN-AS1 regulates the viability and invasion of lung adenocarcinoma A549 cell via miR-519d-3p/MMP2 pathway

AIM To investigate the expression level of long noncoding RNA （lncRNA） TTN antisense RNA 1 （TTN-AS1） in lung adenocarcinoma tissues and the effects of TTN-AS1 silencing on the viability and invasion of lung adenocarcinoma A549 cells. METHODS RT-qPCR was used to detect the expression of TTN-AS1， microRNA-519d-3p （miR-519d-3p） and matrix metalloproteinase 2 （MMP2） mRNA in 32 cases of lung adenocarcinoma and adjacent normal tissues. The untransfected A549 cells were divided into blank group， si-NC group （with si-NC transfection） and si-lncRNA group （with silencing of lncRNA TTN-AS1 expression）， with n=5 in each group. The effects of TTN-AS1 silencing on the viability and invasion of A549 cells were detected by CCK8 and Transwell methods. The targeting regulatory effects of TTN-AS1 on miR-519d-3p and miR-519d-3p on MMP2 were determined by dual-luciferase reporter assay， RNA immunoprecipitation test， RT-qPCR and Western blot. RESULTS The expression level of TTN-AS1 in 32 cases of lung adenocarcinoma tissues is notably higher than that in the adjacent normal tissues （P<0.05）. Silencing of TTN-AS1 in A549 cells significantly suppressed the cell viability and invasion. TTN-AS1 negatively regulated the expression of miR-519d-3p via sponging and absorbing miR-519d-3p. MMP2 is the target gene of miR-519d-3p and can be negatively regulated by miR-519d-3p. Overexpression of MMP2 partially reversed the inhibitory effect of TTN-AS1 silencing and miR-519d-3p overexpression on the invasion of A549 cells. CONCLUSION The lncRNA TTN-AS1 is overexpressed in lung adenocarcinoma tissues， and it regulates lung adenocarcinoma A549 cell viability and invasion via miR-519d-3p/MMP2 pathway.     

Tripchlorolide activates p-ERK and induces autophagy in lung cancer A549 cells

AIM: To investigate the effects of tripchlorolide (TP) on proliferation and autophagy of human lung cancer A549 cells, and explore its mechanism. METHODS: MTT assay was performed to analyze the effect of TP on the viability of human lung cancer A549 cells. The A549 cells were treated with TP, and their autophagy was observed under the fluorescence microscope through acridine orange staining. Green fluorescence spots were observed by fluorescence microscopy through GFP-LC3 plasmid transfection experiment. The levels of LC3 and p-ERK in the A549 cells after TP treatment were determined by Western blot. RESULTS: The viability of human lung cancer A549 cells was significantly inhibited by TP in a dose-time dependent manner (P<0.05). The number of the intracellular acidic follicles dyed with bright red fluorescence was significantly increased after TP treatment in A549 cells. The number of green dot-like congregate autophagosomes in cell cytoplasm was significantly increased after TP treatment in the A549 cells transfected with GFP-LC3 plasmid, while the normal treatment only induced a few cells with autophagosome formation. At the same time, we did not observe the dot-like congregate autophagosomes after TP treatment in the A549 cells transfected with GFP-control plasmid. Compared with control group, the expression of LC3-Ⅱ protein was up-regulated in A549 cells after TP treatment (P<0.01). Furthermore, treatment with TP in A549 cells for 48 h also led to a significant upregulation of phosphorylated form of ERK (P<0.01). In contrast, no significant change in the levels of total ERK protein was observed. Compared with 100 nmol/L TP group, TP+3-MA group down-regulated the protein levels of LC3-Ⅱ (P<0.01) and p-ERK (P<0.01) in the A549 cells. CONCLUSION: TP significantly inhibits the growth of A549 lung cancer cells and induces the autophagy, which may be correlated with upregulation of p-ERK protein.     

Aldolase A level in malignant pleural effusion and its effects on proliferation,migration and invasion of human lung adenocarcinoma cells

AIM：
To investigate the levels of aldolase A (ALDOA), carcinoembryonic antigen (CEA) and lactate dehydrogenase (LDH) in malignant pleural effusion (MPE) from patients with lung cancer and tuberculous pleural effusion (TBPE) from patients with tuberculous pleurisy, and to explore the effects of ALDOA on the proliferation, migration and invasion of human lung adenocarcinoma A549 cells. METHODS：Pleural effusion samples including 65 cases of MPE and 35 cases of TBPE were collected, and the levels of ALDOA, CEA and LDH were detected by ELISA and chemiluminescence assay. After A549 cells were treated with different concentrations of ALDOA, the proliferation, migration and invasion of the cells were investigated by MTT assay, scratch test, Matrigel assay and Transwell invasion assay. RESULTS：The levels of ALDOA, CEA and LDH in MPE were (46.8±21.4) μg/L, (82.2±56.6) μg/L and (755.8±382.5) U/L, respectively, which were significantly higher than those in TBPE ［(23.9±17.2) μg/L, (12.6±9.7) μg/L and (388.4±163.9) U/L, respectively; P<0.01］. The concentration of ALDOA in MPE from adenocarcinoma patients ［(71.7±32.1) μg/L］ was significantly higher than that in MPE from squamous-cell carcinoma patients ［(21.3±14.6) μg/L, P<0.05］. The concentrations of ALDOA in MPE and TBPE were positively correlated with the concentrations of CEA and LDH (P<0.01 or P<0.05). ALDOA enhanced the proliferation, migration and invasion of A549 cells in a concentration-dependent manner. CONCLUSION：The expression level of ALDOA in MPE is significantly higher than that in TBPE, especially in MPE from lung adenocarcinoma patients. There are highly positive correlations between ALDOA and CEA, ALDOA and LDH in pleural effusion. ALDOA concentration-dependently promotes the proliferation, migration and invasion of A549 cells.     

Expression of PLIN3 in lung adenocarcinoma and its correlation with prognosis

AIM To explore the expression of perilipin 3（PLIN3） in lung adenocarcinoma and the relationship between the prognosis of patients and the invasiveness of lung adenocarcinoma cells. METHODS HPA database was used to predict the genes related to poor prognosis of lung cancer and PLIN3 was selected as the research object.HPA database was used to analyze the correlation between PLIN3 and survival rate of lung cancer and lung adenocarcinoma.GEPIA database was used to further verify the correlation between the expression difference of PLIN3 and the survival rate of lung adenocarcinoma patients. The expression of PLIN3 in lung adenocarcinoma was further analyzed by using Ualcan database.Western blot was used to detect the expression of PLIN3 in lung adenocarcinoma cells.siPLIN3 plasmid was constructured and Transwell assay was used to detect the invasion ability of A549 cells after transfection. RESULTS PLIN3 was significantly related to the survival rate of the patients with lung adenocarcinoma and it was over-expressed in lung adenocarcinoma tissues.The expression of PLIN3 was closely related to the stages of cancer and the grades of lymph node metastasis of lung adenocarcinoma.PLIN3 was over-expressed in lung adenocarcinoma cells. The number of the A549 cells passing through Transwell in knock-down group was significantly lower than that in control group. CONCLUSION PLIN3 is highly expressed in lung adenocarcinoma. The expression level of PLIN3 is related to the prognosis of lung adenocarcinoma patients.Knock-down of PLIN3 inhibits the invasion ability of lung adenocarcinoma cells in vitro.