Pulmonary Adenocarcinoma A549 Research Articles

A novel lncRNA-hidden polypeptide regulates malignant phenotypes and pemetrexed sensitivity in A549 pulmonary adenocarcinoma cells

The advance of high-throughput sequencing enhances the discovery of short ORFs embedded in long non-coding RNAs (lncRNAs). Here, we uncovered the production and biological activity of lncRNA-hidden polypeptides in lung adenocarcinoma (LUAD). In the present study, bioinformatics was used to screen the lncRNA-hidden polypeptides in LUAD. Analysis of protein expression was done by western blot or immunofluorescence assay. The functions of the polypeptide were determined by detecting its effects on cell viability, proliferation, migration, invasion, and pemetrexed (PEM) sensitivity. The protein interactors of the polypeptide were analyzed by mass spectrometry after Co-immunoprecipitation (Co-IP) assay. The results showed that the lncRNA LINC00954 was confirmed to encode a novel polypeptide LINC00954-ORF. The polypeptide had tumor-suppressor features in A549 cells by repressing cell growth, motility and invasion. Moreover, the polypeptide enhanced PEM sensitivity and suppressed growth in A549/PEM cells. The protein interactors of this polypeptide had close correlations with RNA processing, amide metabolic process, translation, RNA binding, RNA transport, and DNA replication. As a conclusion, the LINC00954-ORF polypeptide embedded in lncRNA LINC00954 possesses tumor-suppressor features in A549 and PEM-resistant A549 cells and sensitizes PEM-resistant A549 cells to PEM, providing evidence that the LINC00954-ORF polypeptide is a potential anti-cancer agent in LUAD.

Cyclodextrin Dispersion of Mebendazole and Flubendazole Improves In Vitro Antiproliferative Activity

Mebendazole and flubendazole are antihelmintic drugs that have re-entered the research spotlight due to their exhibited anticancer effects, thus making them strong candidates as repurposed drugs. However, these benzimidazole derivatives exhibit poor solubility in water and various organic solvents, which limits their bioavailability. With the aim of obtaining an improved drug solubility and increased biological effect, mebendazole and flubendazole were complexed with 2-hydroxypropyl-β-cyclodextrin (HPBCD). The binary 1:1 conjugates were physicochemically evaluated by X-ray diffraction, thermal analysis, and FTIR spectroscopy, revealing the formation of physical mixtures. The increased aqueous solubility of the binary 1:1 conjugates vs. pure benzimidazole compounds was demonstrated by performing dissolution tests. The in vitro antiproliferative activity of mebendazole and flubendazole, as well as their combination with HPBCD, was tested on two cancer cell lines, human melanoma—A375 and pulmonary adenocarcinoma—A549 by the MTT assay. The cytotoxic activity manifested in a dose-dependent manner while the presence of HPBCD increased the antiproliferative activity against the targeted cells. Treatment of A375 and A549 cell lines with the binary conjugates induced a significant inhibition of mitochondrial respiration, as revealed by high-resolution respirometry studies. Molecular docking analysis showed that one of the mechanisms related to MEB and FLU cytotoxic activity may be due to the inhibition of MEK/ERK proteins.

Palladium complexes with terpene derivatives of ethylenediamine and benzylamine: Synthesis and study of antitumor properties

The synthesis of new terpene ligands and palladium complexes based on them has been described. The stereoselective synthesis of new derivatives (−)-(1R,4S)-camphorquinone and N,N-dimethylethylenediamine (1 and 2) and palladium chelate complexes (3 and 4) based on them is presented. It was found that the direct cyclometallation of (1R,2R,3R,5R)-3-(benzylamino)-2,6,6-trimethylbicyclo[3.1.1]heptane-2-ol (5) with palladium acetate leads to the formation of palladacycle 6. The cytotoxic activity of new (3,4,6) and previously described (7–14) palladium complexes of various types has been studied. The study of the toxic effect was carried out on various cell lines of tumor origin (pulmonary adenocarcinoma A549, neuroblastoma SH-SY5Y, laryngeal epidermoid Hep-2 and cervical carcinoma HeLa cells). It was found that palladium complexes 6–10 with terpene derivatives of benzylamine and a complex 11 with N,N,O-donor terpene ligand have the most pronounced antitumor properties. For 11 the lowest values of the cytotoxic effect IC50 were found in all cell lines, especially in relation to SH-SY5Y (IC50 < 0.1 µM). In the course of studying the possible mechanisms of their antineoplastic action, it was found that these substances are able to modulate the processes associated with oxidative stress and have a damaging effect on mitochondria, as well as inhibit the process of HeLa cancer cell glycolysis.

Nicotine upregulates ACE2 expression and increases competence for SARS-CoV-2 in human pneumocytes.

The coronavirus disease 2019 (COVID-19) pandemic has a variable degree of severity according to underlying comorbidities and life-style. Several research groups have reported an association between cigarette smoking and increased severity of COVID-19. The exact mechanism of action is largely unclear.We exposed low angiotensin-converting enzyme 2 (ACE2)-expressing human pulmonary adenocarcinoma A549 epithelial cells to nicotine and assessed ACE2 expression at different times. We further used the nicotine-exposed cells in a virus neutralisation assay.Nicotine exposure induces rapid and long-lasting increases in gene and protein expression of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) receptor ACE2, which in turn translates into increased competence for SARS-CoV-2 replication and cytopathic effect.These findings show that nicotine worsens SARS-CoV-2 pulmonary infection and have implications for public health policies.

Antiproliferative activity of semisynthetic xylopic acid derivatives

Two ent-kaurene diterpenoids, ent-15- β -acetyloxy-kaur-16-en-19-oic acid (xylopic acid) 1 and ent-7-oxo-kaur-16-en-19-oic acid 2 were isolated from the fruits of Xylopia aethiopica. Chemical manipulation of xylopic acid yielded ent-kaurane derivatives 3, 4, 5, and 6. Their structures were elucidated by spectroscopic analysis, including 1 D- and 2 D-NMR spectroscopies. The antiproliferative activities of compounds 1, 2, 3, 4, and 6 were tested on breast MCF7 and SkBr3, endometrial Ishikawa, ovarian BG-1, mesothelioma IST-MES1 and hepatocellular HepG2 human tumor cells, and on mammalian MRC-10 fibroblast cells. Ketone 2 showed significant antiproliferative activity against MFC7 human breast cancer cells (IC50 = 3 ± 1 µM) and A549 pulmonary adenocarcinoma (8 ± 1 µM), that was higher than the well-known anti-cancer agent cisplatin (IC50 = 19 ± 3 and 15 ± 4 µM, respectively).

Deoxycholic acid as a molecular scaffold for tyrosyl-DNA phosphodiesterase 1 inhibition: A synthesis, structure–activity relationship and molecular modeling study

Para-Bromoanilides of deoxycholic acid with various functional groups on the steroid scaffold were designed as promising tyrosyl-DNA phosphodiesterase 1 (Tdp1) inhibitors. Tdp1 is a DNA repair enzyme, involved in removing DNA damage caused by topoisomerase I poisons; an important class of anticancer drugs. Thus, reducing the activity of Tdp1 can increase the efficacy of anticancer drugs in current use. Inhibitory activity in the low micromolar and submicromolar concentrations was observed with 3,12-dimethoxy para-bromoanilide 17 being the most active with an IC50 value of 0.27 μM. The activity of N-methyl para-bromoanilides was 3–4.8 times lower than of the corresponding para-bromoanilides. Increased potency of the ligands was seen with higher molecular weight and log P values. The ligands were evaluated for their cytotoxic potential in a panel of tumor cell lines; all were nontoxic to the A549 pulmonary adenocarcinoma cell line. However, derivatives containing a hydroxyl group at the 12th position were more toxic than their 12-hydroxyl group counterparts (acetoxy-, oxo- and methoxy- group) against HCT-116 human colon and HepG2 hepatocellular carcinomas. In addition, an N-methyl substitution led to an increase in toxicity for the HCT-116 and HepG2 cell lines. The excellent activity as well as low cytotoxicity, derivative 17 can be considered as a lead compound for further development.

Spatiotemporally Targeted Nanomedicine Overcomes Hypoxia-Induced Drug Resistance of Tumor Cells after Disrupting Neovasculature

Vascular disrupting agents (VDAs) are emerging anticancer agents, which show rising demand for combination with cytostatic drugs (CSDs), owing to inadequate tumor inhibition when applied singly. Nevertheless, the combination remains a challenge due to the different working sites of VDAs and CSDs and hypoxia-induced drug resistance after disrupting neovasculature by VDAs. Herein, we developed a shell-stacked nanoparticle (SNP) for coencapsulation of a VDA combretastatin A-4 phosphate (CA4P) and a proteasome inhibitor bortezomib (BTZ). The SNP could spatiotemporally deliver CA4P to tumor neovasculature and BTZ to tumor cells mediated by the site-specific stimuli-activated drug release. Moreover, the SNP also reversed the drug resistance caused by the overexpressed ABCG2 under CA4P-induced hypoxic conditions. The spatiotemporally targeted combination therapy significantly inhibited the growth of both the human A549 pulmonary adenocarcinoma xenograft model and patient-derived xenograft (PDX) model of colon cancer in mice, providing a promising strategy for treating advanced cancers.

Ocimum sanctum Linn. ethanolic extract inhibits angiogenesis in human lung adenocarcinoma (a549) cells.

Background and Aim:Ocimum sanctum (OS) is a herbal plant, which is easy to find and is widely used as an alternative medication. The previous studies have shown that several species of OS extract have therapeutic properties, and in some cases, antitumor properties. Furthermore, several data have shown the antiproliferative effects of OS extract in cases of breast cancer, human fibrosarcoma, and oral cancer. Lung adenocarcinoma is a major cause of male cancer worldwide; however, the effect of OS (of Indonesian origin) on the metastasis of human alveolar pulmonary adenocarcinoma A549 cells remains unclear. This study aimed to analyze the antiangiogenic effects of OS ethanolic extract in A549 lung adenocarcinoma cells.Materials and Methods:An angiogenesis assay was performed by seeding A549 cells on extracellular matrix solution and observing tube formation using an inverted microscope. Enzyme-linked immunosorbent assay for αvβ3, matrix metalloproteinase (MMP)-2, and MMP-9 was performed by analyzing the cell lysate after a given treatment.Results:OS ethanolic extract significantly inhibited tube formation of A549 cells and suppressed the expression of integrin αvβ3, MMP-2, and MMP-9.Conclusion:Our findings indicate that OS ethanolic extract disrupts angiogenesis of A549 cells, which may result from the disruption of cell migration and proliferation as a consequence of downregulation of αvβ3, MMP-2, and MMP-9. Taken together, OS ethanolic extract may represent a good therapeutic candidate for the treatment of metastasis in lung adenocarcinoma. Further studies are warranted to further establish the efficacy of OS in the treatment of lung adenocarcinoma.

Ethanolic extract Ocimum sanctum Linn. induces an apoptosis in human lung adenocarcinoma (A549) cells

Ocimum sanctum (OS) is tropical herbal plant which is easy to find and widely used as a vegetable food in Indonesia. In last decade, lung adenocarcinoma was in top position as male cancer disease in Indonesia. Recently, emerging data showing the extracts of different species of Ocimum exhibiting the anti-tumor properties. Further studies on lung lewis carcinoma demonstrated pro-apoptosis effects after the treatment with Ocimum extracts. However, the effect of OS of Indonesian origin in human alveolar pulmonary adenocarcinoma A549 cells remain unclear. Therefore, we aimed to investigate effects of ethanolic extract OS (EEOS) in A549 cell culture systems. Cell adhesion and viability assays revealed that EEOS significantly decreased the attachment into extracellular matrix of A549 cells. Morphological examination AO/EB and DAPI staining indicated that EEOS induced the cells shrinkage, DNA fragmentation and condensation of A549 cells. Further, EEOS treatment induced the apoptosis rate followed by up-regulation of reactive oxygen species (ROS), caspase-3 expression and decreased anti-apoptotic protein Bcl-2. This condition also suppressed the expression of SOD2 as well as the GPx. In conclusion, our findings indicate that EEOS suppressed the viability of A549 cells, which may result from the activation of ROS promoting the apoptosis signaling via mitochondrial intrinsic pathway. Taken together, EEOS might be a good therapeutic potential to further understand its properties in the treatment of lung carcinoma.

Attenuation of replication stress-induced premature cellular senescence to assess anti-aging modalities.

Described is an in vitro model of premature senescence in pulmonary adenocarcinoma A549 cells induced by persistent DNA replication stress in response to treatment with the DNA damaging drug mitoxantrone (Mxt). The degree of cellular senescence, based on characteristic changes in cell morphology, is measured by laser scanning cytometry. Specifically, the flattening of cells grown on slides (considered the hallmark of cellular senescence) is measured as the decline in local intensity of DNA-associated DAPI fluorescence (represented by maximal pixels). This change is paralleled by an increase in nuclear area. Thus, the ratio of mean intensity of maximal pixels to nuclear area provides a very sensitive morphometric biomarker for the degree of senescence. This analysis is combined with immunocytochemical detection of senescence markers, such as overexpression of cyclin kinase inhibitors (e.g., p21(WAF1) ) and phosphorylation of ribosomal protein S6 (rpS6), a key marker associated with aging/senescence that is detected using a phospho-specific antibody. These biomarker indices are presented in quantitative terms defined as a senescence index (SI), which is the fraction of the marker in test cultures relative to the same marker in exponentially growing control cultures. This system can be used to evaluate the anti-aging potential of test agents by assessing attenuation of maximal senescence. As an example, the inclusion of berberine, a natural alkaloid with reported anti-aging properties and a long history of use in traditional Chinese medicine, is shown to markedly attenuate the Mxt-induced SI and phosphorylation of rpS6. The multivariate analysis of senescence markers by laser scanning cytometry offers a promising tool to explore the potential anti-aging properties of a variety agents.

An Integrated Quad-Modality Molecular Imaging System for Small Animals

We developed a novel integrated quad-modality system that included 3 molecular imaging methods (PET, SPECT, and fluorescence molecular imaging [FMI]) and 1 anatomic imaging modality (CT). This system could study various biologic processes in the same animal using multiple molecular tracers. In addition to the technology development, we also discussed the optimization strategy of the imaging protocols. The performance of this system was tested, and the in vivo animal experiment showed its power to trace 3 different molecular probes in living tissues. Our results demonstrated that this system has a great potential for the preclinical study of diseases. A prototype system integrating PET, SPECT, CT, and a charge-coupled device-based free-space FMI system has been developed. Imaging and fusion capabilities of the system were evaluated by a multimodality phantom. In addition, a mouse disease model with both tumor and inflammation was studied by this system to examine the in vivo performance. The 3 types of molecular probes-(18)F-FDG, [(99m)Tc(HYNIC-3PRGD2)(tricine)(TPPTS)] ((99m)Tc-3PRG2) (HYNIC = 6-hydrazinonicotinyl; TPPTS = trisodium triphenylphosphine-3,3',3″-trisulfonate; 3PRGD2 = PEG4-E[PEG4-c(RGDfK)]2), and 3-(triethoxysilyl) propyl-Cy7-entrapped core-cross-linked polymeric micelle (Cy7-entrapped CCPM) nanoparticles-were used to target 3 different biologic processes in the tumor caused by pulmonary adenocarcinoma A549 cells. Moreover, the strategy to optimize multimodal molecular imaging procedure was studied as well, which could significantly reduce the total imaging time. The imaging performance has been validated by both phantom and in vivo animal experiments. With this system and optimized imaging protocol, we successfully differentiated diseases that cannot be distinguished by a single molecular imaging modality. We developed a novel quad-modality molecular imaging system that integrated PET, SPECT, FMI, and CT imaging methods to obtain whole-body multimodality images of small animals. The imaging results demonstrated that this system provides more comprehensive information for preclinical biomedical research. With optimized imaging protocols, as well as novel molecular tracers, this quad-modality system can help in the study of the physiology mechanism at an unprecedented level.

Expression and significance of IKBKB in pulmonary adenocarcinoma A549 cells and its cisplatin-resistant variant A549/DDP

背景与目的肺癌顺铂耐药在临床治疗中广泛存在，严重影响了肺癌患者的治疗效果，因此研究肺癌耐药机制对新药的研发和解决临床肿瘤耐药有十分重要的意义。IKBKB是组成IKK复合物重要的催化亚基之一，其对核转录因子NF-κB的激活起到重要调控作用。本研究旨在探讨IKBKB基因在肺腺癌顺铂耐药细胞株（A549/DDP）与其亲本肺腺癌A549细胞株中的表差异及其调控肺腺癌顺铂耐药的机制。方法应用MTT法检测A549和A549/DDP细胞株顺铂敏感性及IKBKB基因对A549细胞株顺铂耐药性的影响。Real-time PCR检测肿瘤细胞中IKBKB基因mRNA变化，流式细胞学检测肿瘤细胞凋亡率，双荧光素酶报告基因实验检测NF-κB的活性。结果A549细胞与A549/DDP细胞在IC50和凋亡率方面均有统计学差异，IKBKB基因在A549/DDP细胞株中mRNA表达水平明显高于A549。与对照组比较，pcDNA3.1/IKBKB转染A549细胞后，IKBKB基因在mRNA水平明显升高，A549细胞顺铂耐药性明显增加，IC50增加2.85倍，凋亡率减少59%，NF-κB的活性明显升高。结论IKBKB基因通过激活NF-κB信号通路抑制细胞凋亡，从而导致细胞耐药性增加，这一研究结果对新抗肿瘤药物的研发和解决肿瘤耐药难题有重要意义。

Huaier suppresses proliferation and induces apoptosis in human pulmonary cancer cells via upregulation of miR-26b-5p.

Various studies have reported that Huaier possesses anti-tumor effects. However, the mechanisms are not completely elucidated. Here, we found 66 differentially expressed miRNAs in Huaier-treated pulmonary adenocarcinoma A549 cells, with upregulation of miR-26b-5p. Transfection of A549 cells with miR-26b-5p mimic inhibited proliferation and induced apoptosis, while transfection of Huaier-treated A549 cells with a miR-26b-5p inhibitor reversed the effects of Huaier. EZH2 was verified as the target of miR-26b-5p. Thus, our findings indicate that Huaier might suppress proliferation and induce apoptosis in lung cancer cells via a miR-26b-5p-EZH2-mediated approach, which provides a new perspective for understanding the anti-tumor effects of Huaier.

Role of integrin β1 in sensitivity to chemotherapy of pulmonary adenocarcinoma A549

Objective The aim of our study was to investigate the effect of integrin β1 on influencing the sensitivity to chemotherapy of human pulmonary adenocarcinoma A549 cells.

Enhancement of Recombinant Human Endostatin on the Radiosensitivity of Human Pulmonary Adenocarcinoma A549 Cells and Its Mechanism

We observed the effects of endostar on the radiosensitivity of pulmonary adenocarcinoma A549 cells and found that endostar inhibited A549 cell growth under normoxia and hypoxia in time and dose-dependent manners; the D0 and Dq values in control and endostar groups were (1.36 and 1.30) versus (1.019 and 1.015) under normoxia and (1.693 and 1.39) versus (2.453 and 1.026) under hypoxia, respectively; SER was 1.04 under normoxia and 1.22 under hypoxia in endostar group; under normoxia, the apoptosis rates in control, radiotherapy, endostar and combination groups were 15.9 ± 0.57%, 42.7 ± 0.37%, 19.9 ± 0.48%, and 41.5 ± 0.38%, respectively, with no significant difference between combination and radiotherapy groups; there was significant difference in G2/M phase cells between combination and radiotherapy groups (P = 0.028); under hypoxia, the apoptosis rates in the four groups were 16.7 ± 0.67%, 30.1 ± 0.95%, 26.7 ± 0.62%, and 36.3 ± 0.71%, respectively, with significant difference between combination and radiotherapy groups; G2/M phase cells were higher in combination group than radiotherapy group (P = 0.000); G2/M phase cells were higher in hypoxic combination group than in normoxic combination group (P = 0.003). Based on these results, we conclude that under hypoxia, endostar can enhance the radiosensitivity of A549 cells through G2/M arrest.

Measurement of DNA Double-Strand Break Yield in Human Cancer Cells by High-Current, Short-Duration Bunches of Laser-Accelerated Protons

To investigate the radiobiological effects of high dose rates that are attributed to high current, short bunch beam generation with laser-dreven ion acceleration, we have developed an experimental setup that uses laser-accelerated protons. In-vitro human lung cancer cells: A549 pulmonary adenocarcinoma are irradiated with a laser-accelerated proton bunches with a duration of 2×10-8 s and flux of ∼1015 cm-2 s-1, amounting to single bunch absorbed dose at the 1 Gy level. The double-strand break (DSB) yield in cell DNA is analyzed for the laser-accelerated proton beam at an average LET of 41 keV/µm.

Cell fixation in zinc salt solution is compatible with DNA damage response detection by phospho‐specific antibodies

By virtue of superior preservation of proteins and nucleic acids the zinc salt-based fixatives (ZBF) has been proposed as an alternative to precipitants and cross-linking fixatives in histopathology. It was recently reported that ZBF is compatible with analysis of cell surface immunophenotype and detection of intracellular epitopes by flow cytometry. The aim of this study was to explore whether ZBF is also compatible with the detection of DNA damage response assessed by phospho-specific antibodies (Abs) detecting phosphorylation of the key proteins of that pathway. DNA damage in human pulmonary adenocarcinoma A549 cells was induced by treatment with the DNA topoisomerase I inhibitor camptothecin and phosphorylation of histone H2AX on Ser139 (γH2AX) and of ATM on Ser1981 was detected with phospho-specific Abs; cellular fluorescence was measured by laser scanning cytometry (LSC). The sensitivity and accuracy of detection of H2AX and ATM phosphorylation concurrent with the detection of DNA replication by EdU incorporation and "click chemistry" was found in ZBF fixed cells to be comparable to that of cell fixed in formaldehyde. The accuracy of DNA content measurement as evident from the resolution of DNA content frequency histograms of cells stained with DAPI was somewhat better in ZBF- than in formaldehyde-fixed cells. The pattern of chromatin condensation revealed by the intensity of maximal pixel of DAPI that allows one to identify mitotic and immediately post-mitotic cells by LSC was preserved after ZBF fixation. ZBF fixation was also compatible with the detection of γH2AX foci considered to be the hallmarks of induction of DNA double-strand breaks. Analysis of cells by flow cytometry revealed that ZBF fixation of lymphoblastoid TK6 cells led to about 60 and 33% higher intensity of the side and forward light scatter, respectively, compared to formaldehyde fixed cells.

Magnetic Resonance Imaging Contrast Agent: cRGD-Ferric Oxide Nanometer Particle and Its Role in the Diagnosis of Tumor

To construct tumor-targeted nanometer particles as a negative magnetic resonance imaging (MRI) contrast agent. Ultra-small superparamagnetic iron oxide (USPIO) nanometer particles were prepared by one-step chemical precipitation. The covalent bond between cyclic RGD (cRGD) containing an Arg-Gly-Asp sequence targeting integrin-alphavbeta3, and USPIO was conducted by chemical crosslinking. The physico-chemical property of cRGD-USPIO was detected. Prussian blue staining was applied to detect the specific binding capacity of cRGD-USPIO and USPIO to human pulmonary adenocarcinoma A549 cells and human umbilical vein endothelial cells. Subsequently, A549 xenografts in nude mice were established, and intravenous injections of USPIO and cRGD-USPIO into the vena caudalis were performed. The enhancement of cRGD-USPIO against tumor MRI signal was evaluated. The mean hydrodynamic diameter of cRGD-USPIO was 43.97 +/- 10.10 nm and the size of the ferric oxide core was 5-10 nm. The specific saturation magnetization was 59.94 A x m2 x Kg(-1). The cell conjugation assay results indicated that the positive staining of the cRGD-USPIO group was significantly enhanced. The in vivo MRI diagnosis indicated that the cRGD-USPIO tumor signal was significantly reduced compared to that of the USPIO group (P < 0.01). The targeted superparamagnetic iron oxide nanometer particle can be a novel MRI negative contrast agent for more specific tumor early diagnosis.

Effects of antidiabetic drug metformin on the migration and invasion abilities of human pulmonary adenocarcinoma A549 cell line in vitro.

There is growing evidence that metformin, a clinically widely used drug in the treatment of type II diabetes, may impede the growth of human tumors. However in a recent study it was found that metformin treatment might result in promotion of the angiogenic phenotype and promote early tumorigenic progression. In order to evaluate the relevance between metformin and tumor metastases, we investigated the effects of metformin on the migration and invasion abilities of human pulmonary adenocarcinoma cell line A549 in vitro and explored the possible underlying mechanisms. A549 cells were treated with 0.5 mmol/L, 2 mmol/L and 8 mmol/L metformin for 72h. The laterad-migration and invasion abilities of the cells in vitro were evaluated by scratch assay and Boyden-Chamber assay, respectively. Expressions of MMP2 and MMP9 mRNA of the cells before and after metformin treatment were measured by Real-Time PCR. The migration rate of A549 cells was increased after metformin treatment at the concentration of 8mmol/L. The invasion ability was also significantly increased from 37.4±4.6 to 59.8±7.2(P<0.05) by 8mmol/L metformin treatment. No significant difference of the migration and invasion abilities was observed between the Group 0.5mmol/L, 2mmol/L and the Control. The expressions of MMP2 and MMP9 mRNA were both up-regulated after metformin treatment, while in the 8mmol/L Group the genes changes were the most significant. Metformin can increase the migration speed and enhance invasion abilities of A549 cells in vitro, which may be attributed to the up-regulation of MMP2 and MMP9.

Inhibitory effect of radiotherapy combined with weekly recombinant human endostatin on the human pulmonary adenocarcinoma A549 xenografts in nude mice

The aim of this study was to investigate the inhibitory effect of radiotherapy combined with weekly recombinant human endostatin (RHES) on the human pulmonary adenocarcinoma A549 xenografts in nude mice. The 40 A549 xenograft nude mice models were randomly divided into 4 groups (each group with 10 nude mice). Single radiotherapy group (group 1) was given a single external irradiation (6MV-X ray, 10 Gy) and peritumoral subcutaneous injection of 0.2 ml normal saline every day for 7 days. Single RHES group (group 2) was given peritumoral subcutaneous injection of 0.2 ml RHES (0.75 mg/ml) for 7 days. Combination therapy group (group 3) was given radiotherapy as the same as group 1 and RHES as the same as group 2. Control group was given normal saline as the same as group 1. The tumor volume was smaller in group 3 than in control group from the 8th day after treatment ( P < 0.05) and tumor regression occurred from the second week after treatment in group 3. On the 15th day after treatment, the inhibitory rates of tumor volume were 69.65%, 92.64% and 116.4% in groups 2, 1 and 3, respectively; MVD number was lower in group 3 than in group 1 ( P < 0.05); there was no statistical significance in VEGF expression between group 2 and control group as well as between group 3 and group 1 ( P > 0.05). Apoptosis was marked in group 3. Radiotherapy combined with weekly RHES can significantly inhibit tumor growth and earlier induce tumor regression, which may be related to the improvement of tumor hypoxia and the inhibition of radiation-induced tumor angiogenesis. Short-term application (1 week) of RHES is beneficial to clinical practice.