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.     

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.     

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.     

Clinical significance of KLF15 expression in human lung adenocarcinoma

AIM: To explore the clinical significance of Krüpple-like factor 15 (KLF15) protein expression in the patients with lung adenocarcinoma for exploring the therapeutic and prognositic biomarkers of lung cancer. METHODS: Four cases of lung adenocarcinoma tissues and matched adjacent tissues were collected from our hospital, and the expression of KLF15 protein in these tissues was analyzed by Western blot. At the same time, 72 cases of archived paraffin-embedded samples and clinical data of the patients with lung adenocarcinoma were also collected. The KLF15 protein expression in the archived paraffin-embedded lung adenocarcinoma samples was detected by immunohistochemical staining. The correlations between KLF15 protein expression and clinical characteristics of the patients including prognosis were also analyzed. In addition, the KLF15 protein was up-regulated in A549 cells, and then the effects of KLF15 protein on the viability of the cells were measured by CCK-8 assay. RESULTS: The protein expression of KLF15 in the 4 cases of lung adenocarcinoma tissues was significantly lower than that in matched paracancerous tissues. Fifty-three cases of lung adenocarcinoma specimens showed low expression or no expression of KLF15 protein in total 72 cases (73.6%). The 5-year survival rate of the patients with high expression of KLF15 protein in their specimens was higher than that of the patients with the low expression of KLF15 protein (P<0.01), and the expression of KLF15 protein was significantly correlated with the pathological staging (P<0.01) and T stage (P<0.01) of the patients with lung adenocarcinoma. Furthermore, the low expression of KLF15 protein was an important poor prognostic indicator of the patients. Up-regulation of KLF15 protein in the A549 cells significantly inhibited the growth of the cells. CONCLUSION: KLF15 inhibits the growth of lung adenocarcinoma cells. It could be used as a therapeutic target and a prognostic biomarker for the patients with lung adenocarcinoma.     

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.     

Inhibitory effects of nm23-H1 gene on proliferation and invasion of A549 cell line

AIM:To study the inhibitory effects of nm23-H1 gene on proliferation and invasion of human lung adenocarcinoma A549 cell line. METHODS:Recombinant eukaryotic expression vector pcDNA3.1-nm23-H1 containing full length of human nm23-H1 cDNA was constructed and transfected into a human lung adenocarcinoma A549 cell line by lipofectamine. Cell strain that expressed nm23-H1 stably was screened out by G418 and named pcDNA-nm23-A549. Expression of nm23-H1 was identified by RT-PCR and immunohistochemistry. Growth curves were drawn to detect the inhibitory effects on cell proliferation. Cell cycle of pcDNA-nm23-A549 was examined by flow cytometry. Atomic force microscopy was used to observe the filopodia on the surface of the cells. RESULTS:Introduction of nm23-H1 obviously inhibited the proliferation of A549. Expression of nm23-H1 did not induce apotosis in A549 cells but increased the percentage of phase G₁ cells and decreased phase S cells. Meanwhile, phase G₁ to phase S transition was restrained. Filopodia in the cell surface was much fewer and its structure changed in cells transformed. CONCLUSION:nm23-H1 is capable of inhibiting A549 proliferation and decreasing its metastatic ability, probably by interfering with cell cycle and cell surface structure.     

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.     

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.     

Construction of HLCDG1 gene siRNA expression vector and its regulation on cell cycle and proliferation in A549 cells

AIM:HLCDG1 is a novel gene cloned recently, and its expression inhibits significantly the growth of A549 cells and tumorigenesis of A549 cells transplanted in nude mice. In this study, our aim was to construct HLCDG1 gene short/small interference double-strand RNA (siRNAs) expression vector and to observe its influence on cell cycle and proliferation of A549 cells. METHODS:Using RNA interference (RNAi) techniques, a DNA vector-driven siRNAs expression vector was constructed, and a lung carcinoma cell line stably expressing siRNAs was also selected. Sequentially, using flow cytometry analysis and MTT assay, the changes of cell cycle and cell proliferation in this cell line were observed. RESULTS:Four site-match and one site-mismatch plasmids were constructed, which were named pHL-si-1, pHL-si-2, pHL-si-3, pHL-si-4 and pHL-si-c. These plasmids were co-transfected with a pcDNA3.1(+)/HLCDG1 plasmid into A549 cells, respectively. Among five co-transfected A549 cell lines, a A549 cell line co-transfected by the pcDNA3.1(+)/HLCDG1 and pHL-si-1 plasmids, namely A549-HLCDG1-si-1, showed nearly complete inhibition of HLCDG1 expression. MTT assay and flow cytometry analysis indicated that A549-HLCDG1-si-1 cells, namely the HLCDG1 gene-silencing cells, got a faster growth compared with other HLCDG1 expression cell lines, and that HLCDG1 gene-silencing induced A549-HLCDG1-si-1 cells into S phase and G2+M phase significantly. CONCLUSION:These results suggest that the HLCDG1 gene is proved to have a markedly inhibitory effect on growth in A549 lung carcinoma cells. This study might provide some understanding of the biological function and molecular mechanism of HLCDG1 gene.     

Differential proteomic analysis of human lung adenocarcinoma cell line and bronchial epithelium cell line

AIM: The comparative analysis of total proteins expressed differentially between adenocarcinoma cell line A549 (a human lung adenocarcinoma) and normal cell line HBE (a human lung bronchial epithelium) was conducted to search the proteins involved in tumorigenesis and potential biomarkers of diagnosis or prognosis. METHODS: The proteins of dramatic differential expression were screened in adenocarcinoma cell Line A549 and normal cell line HBE by using immobilized pH gradient-two dimensional polyacrylamide gel electrophoresis combined with MALDI-TOF/TOF tandem mass spectrometry. Furthermore, the differential expressed proteins were confirmed by the method of Western blotting. RESULTS: Compared with the two cell lines, 21 differential expressed proteins were found and their functions involves in cell metabolism, protein modification, cell motility, protein trafficking and signal transduction. The up-regulation of heat shock protein beta-1 (HSPB1) in A549 cells was identified and confirmed. CONCLUSION: These results suggest that dramatic differential proteomic expression exists between the two cell lines. The high level of HSPB1 might play an important role in the process of tumorigenesis.     

Effect of antisense RNA targeting Polo-like kinase 1 on cell growth in A549 lung cancer cells

AIM: To investigate the effect of Polo-like kinase-1 (Plk1) depletion on cell cycle progression and cell growth in lung cancer cells.METHODS: A recombinant plasmid containing antisense RNA targeting Plk1 (pcDNA3-Plk1) was transfected into A549 cells by lipofectine. RT-PCR and Western blotting were used to examine Plk1 gene expression. Cell proliferation was evaluated by cell counting and BrdU labeling. Cell cycle distribution and apoptosis were examined by flow cytometry. Inhibition rate (IR) of vinorebline (NVB) was determined by MTT assay. RESULTS: After transfected with pcDNA3-Plk1 into A549 cells, the expression levels of Plk1 mRNA and protein were greatly decreased. Abnormal morphological changes of cells and growth inhibition were observed in pcDNA3-Plk1 transfected cells. The BrdU labeling index was significantly lower than that in control group (P<0.05). Cells showed a strong G₂/M arrest and apoptosis 72 h post transfection. IR of vinorebline in pcDNA3-Plk1 transfected groups was significantly higher than that in other groups. CONCLUSION: Antisense RNA targeting Plk1 is capable of suppressing Plk1 expression, and therefore, significantly inhibits cellular proliferation, induces cell cycle arrest and apoptosis. Moreover, the sensitivity of lung cancer cells to chemotherapy is increased.     

Effect of siRNA for survivin gene on growth and apoptosis in A549 cells

AIM:To observe the influence of lentiviral vectors expressing siRNA for survivin gene knockdown in A549 cells, sequentially as tools to explore the molecule pathogenesis and new gene therapy of lung adenocarcinoma. METHODS:The lentiviral vectors, which express survivin siRNA, were constructed and transfected into A549 cell strain. The titers of the lentiviruses were determined by 293T cells. The expressions of survivin and caspase-3 were detected by Western blotting and RT-PCR. The cell cycle and cell growth of A549 cells were examined by MTT and FCM．RESULTS:The expression of survivin was suppressed effectively by siRNA targeting survivin. The expression of survivin mRNA decreased by 97%. The expression of survivin protein decreased by 94%. The rate of cell growth was decreased. The G1 phase cells were increased, whereas S phase cells were decreased. CONCLUSION:The lentivirus vectors expressing siRNA for survivin can significantly inhibit gene expression and the cell growth, and markedly induce the apoptosis. It is hopeful to be a new gene therapy of lung adenocarcinoma.     

Sodium glycididazole combined with cisplatin efficiently promotes p21 expression in lung adenocarcinoma

AIM:To investigate the effect of sodium glycididazole (CMNa) on the sensitivity of lung adenocarcinoma to cisplatin. METHODS:The microarray data of human lung adenocarcinoma A549 cells treated with cisplatin from NCBI public database were reanalyzed for searching the genes with significantly differential expression. The A549 cells were used in the study and treated with CMNa+cisplatin. The expression levels of the verified candidate genes from database searching were detected by real-time PCR. The role of CMNa in the expression of p21 and its upstream target p53 was also determined. RESULTS:A list of candidate genes from the microarray dataanalysis was obtained, in which p21 was verified in A549 cell line treated with cisplatin by database searching and analyzing. A549 cells were treated with CMNa and cisplatin, and p21 expression was enhanced in the cells treated with CMNa+cisplatin but not CMNa alone. In addition, enhanced p21 expression in A549 cells treated with CMNa+cisplatin was mediated by promotion of the upstream p53 level. CONCLUSION:CMNa co-operates with cisplatin to improve p21 expression in human lung adenocarcinoma, which is mediated through enhancement of the p21 upstream target p53, indicating another new insight of CMNa function in radiosensitivity of human lung adenocarcinoma.     

Radiosensitizing effect of 2-methoxyestradiol on NSCLC cell lines by blocking cell cycle

AIM: To investigate the efficiency of 2-methoxyestradiol (2-ME) as radiosensitizing agent for the treatment of lung cancer cells. METHODS: Cell line A549 and GLC-82 originated from human non-small cell lung cancer were cultured in vitro. Study group (2-ME in different concentrations) and control group without 2-ME were set up. Cell proliferation was measured by MTT assay that lung cancer cells were treated with 2-ME for 24 h, then the cells were exposed from 0 to 8Gy radiation, and the survival fraction was determined by clone forming test. Flow cytometry was used to measure the effects of 2-ME on cell cycle distribution. RESULTS: MTT assay showed minimum effective concentration value was 0.15625×10-6 mol/L in GLC-82 and 1.25×10-6 mol/L in A549 cells. Compared to control group, exposed GLC-82 cells or A549 cells to minimum effective concentration of 2-ME for 24 h before irradiation resulted in an enhancement of radiation. The protection enhancement factor was 1.98 and 2.06 in GLC-82 and A549 cells, respectively. Flow cytometry analysis of cell cycle progression demonstrated G2/M phase arrest in both cells in a dose dependent manner. No obvious change of CDK2 activity in both GLC-82 cells and A549 cells was observed. CONCLUSION: 2-ME enhances radiosensitivity by G2/M phase arrest in the cell cycle.     

Expression and prognostic significance of SLP-2 in gastric cancer

AIM: To investigate the expression of the red cell membrane integration protein SLP-2 (stomatin-like protein 2) in gastric cancer tissues and to analyze its correlation with clinicopathological manifestations and prognosis. METHODS: One hundred and ninety gastric cancer tissue samples with detailed clinical information were collected from the Department of Pathology, Sun Yat-sen University Cancer Center. The protein expression of SLP-2 in ganstric cancer was detected by the method of immunohistochemistry. The relationships between SLP-2 expression and the clinicopathological manifestations were evaluated. RESULTS: The positive rate of SLP-2 in gastric cancer tissue was 63.2% (120/190). SLP-2 expression was relevant to infiltration depth, TNM stage and lymph node metastasis (P<0.05). However, no statistical difference was observed in the SLP-2 expression associated with sex, age, differentiation, tumor size and distant metastases. Kaplan-Meier survival curves revealed that increased expression of SLP-2 was associated with poor prognosis in gastric adenocarcinoma patients (P<0.01). Based on the univariate analysis, 7 factors were found to have statistical significance of associations with overall survival, including SLP-2 expression, lymph node metastasis, histological grade, tumor size, invasive depth, distant metastases and the 7th edition of the UICC TNM classification. Only the tumor size and the 7th edition of the UICC TNM classification were independent prognostic factors for overall survival in the multivariate analysis. CONCLUSION: SLP-2 is highly expressed in gastric adenocarcinoma tissues and may play an important role in tumor progression and metastasis. Although SLP-2 is not an independent prognostic factor, it may influence the prognosis of gastric cancer. Increased expression of SLP-2 can be used for predicting unfavorable prognosis in gastric adenocarcinoma patients.     

Effect of rapamycin on proliferation,invasion, adhesion,apoptosis and autophagy of human lung adenocarcinoma A549 and resistant A549/DDP cells treated with cis-diamminedichloroplatinum

AIM: To study the effect of rapamycin (Rap) on the proliferation, invasion, adhesion, apoptosis and autophagy of human adenocarcinoma A549 and resistant A549/DDP cells treated with cis-diamminedichloroplatinum (DDP). METHODS: Human adenocarcinoma A549 and resistant A549/DDP cell lines were cultured. The inhibitory effects of Rap alone or combined with DDP on A549 and resistant A549/DDP cells were detected by MTT assay. The in vitroinvasion abilities of the 2 cell lines treated with Rap alone or combined with DDP were detected by Transwell methods. The in vitroadhesion abilities of the 2 cell lines treated with Rap alone or combined with DDP were detected by adhesion experiments. The apoptosis of A549 and resistant A549/DDP cells induced by Rap alone or combined with DDP was analyzed by flow cytometry. The cell autophagy marker proteins beclin-1 and LC3 in A549 and resistant A549/DDP cells treated with Rap alone or combined with DDP were detected by Western blotting.RESULTS: Compared with Rap or DDP alone group, the combination of Rap and DDP significantly inhibited the proliferation, invasion and adhesion of A549 and resistant A549/DDP cells in vitro, and promoted the cell apoptosis and autophagy marker proteins beclin-1 and LC3 expression (all P＜0.05).CONCLUSION: Rap enhances the effect of DDP through promoting the cell autophagy, thereby inhibiting the proliferation, invasion and adhesion of A549 and resistant A549/DDP cells and inducing the cell apoptosis with a synergistic effect.     

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.