Effects of neuro-immuno-modulation on healing of wound combined with local radiation injury in rats.

PURPOSE: To investigate effects of neuro-immuno-modulation on wound healing by observing changes of cytokines and hypothalamic-pituitary-adrenal (HPA) axis hormones in acute stress reaction in rats with wound and combined local radiation injury. METHODS: Sixty female Wistar rats (weighting 200 ± 20 g) were randomly divided into normal control group, wound group and combined wound-local radiation (CWR) group (25 Gy local radiation post wound), 20 rats in each group. Contents of IL-1ß, IL-6 and IFN-γ and IL-4 in serum were measured and changes of adrenocorticotropic hormone (ACTH) and glucocorticoid (GC) in serum were analyzed by using enzyme-linked immunosorbent assay and radioimmunologic assay, respectively at different time points post wound and radiation. RESULTS: (1) The level of IFN-γ, one of the Th1 cell cytokines increased significantly at 14 d post CWR, which was markedly higher than that in control group and wound group. However, the level of IL-4, IL-1ß and IL-6, one of the Th2 cell cytokines, did not show obvious change. (2) Ratio of Th1/Th2 (IFN-γ/IL-4) in wound group and CWR group increased significantly at 7 d after wound and radiation, which suggested that Th1/Th2 balance drifted to Th1 immune response. The ratio of Th1/Th2 in wound group returned to the normal level up to 14 d after the wound and radiation, while the Th1/Th2 ratio in CWR group increased persistently and was much higher than that in control and wound groups. (3) Level of serous ACTH and GC in CWR group increased at 3 d post wound and radiation, and among them, level of GC showed statistically significant increase, which was much higher than that in control and wound groups. CONCLUSION: Level of serous neurohormone GC in rats increased significantly immediately after wound and radiation; while the level of IFN-γ showed significant increase only up to 14 d after wound and radiation, and the Th1/Th2 imbalance sustained till 28 d post wound and radiation. In order to reduce acute damage caused by CWR, organic immune system and nerve system showed up a marked regulate effects simultaneously and mutually. Nonetheless, the excessive stress induced by CWR causes disturbance of immunoregulation, which is one of the key reasons for delayed wound healing in CWR.

Resveratrol attenuates left ventricular remodeling in old rats with COPD induced by cigarette smoke exposure and LPS instillation.

The objective of this study was to investigate left cardiac damage and the cardioprotective effects of resveratrol in old rats with COPD. Rats 22 months old were divided into three groups: control (CTL), smoking and lipopolysaccharides (SM/LPS), and SM/LPS plus resveratrol (SM/LPS-Res). Cardiac function, pathology, oxidative stress, and apoptosis index were measured. Expression of myocardial SIRT1 was studied by real-time quantitative polymerase chain reaction (PCR) and Western blot detection. The heart weight-body weight ratio (LVW/BW) increased in the SM/LPS group compared with the CTL group. Both the LVW/BW and the area of fibrosis in the SM/LPS-Res group decreased compared with those in the SM/LPS group. 8-OHdG expression increased in cardiac tissue of rats in the SM/LPS group, which could be inhibited by resveratrol. Resveratrol significantly increased the activity of superoxide dismutase (SOD) and reduced the cardiac malonyldialdehyde (MDA) level in the SM/LPS-Res group. There was a significant decrease in the extent of cardiomyocyte apoptosis in the SM/LPS-Res group compared with the SM/LPS group. SIRT1 mRNA increased in the SM/LPS-Res group compared with the SM/LPS group. In conclusion, resveratrol attenuated cardiac oxidative damage and left ventricular remodeling and enhanced the decreased expression of SIRT1 in hearts of old rats with emphysema and thus might be a therapeutic modality for cardiac injury complicated in chronic obstructive pulmonary disease (COPD).

[Suppression of experimental abdominal aortic aneurysm by saturated hydrogen saline: a preliminary study with rats].

OBJECTIVE: To investigate the effects of saturated hydrogen saline on the prevention of abdominal aortic aneurysm (AAA) induced by calcium chloride in a rat model. METHODS: In healthy male Sprague-Dawley rats, AAA was induced by infiltration of abdominal arota with 0.5 mol/L calcium chloride. Saturated hydrogen saline (5 ml·kg(-1)·d(-1)) or saline was administred intraperitoneally once daily. Twenty-eight days later, the diameter of the aorta was measured, and the aortic tissue was exercised for histological examination. Pro-inflammatory cytokines (tumor necrosis factor α (TNF-α), IL-1ß) in AAA tissue were detected with ELISA. The protein expression and mRNA expression of matrix metalloproteinase 2 (MMP-2) and MMP-9 in AAA tissue were observed by immunohistochemistry staining and real-time PCR. RESULT: The aorta diameter of the experiment group and control group were (2.2 ± 0.3) mm and (3.4 ± 0.5) mm, the tissue IL-1ß levels were (81 ± 29) ng/L and (165 ± 51) ng/L, the tissue TNF-α levels were (109 ± 46) ng/L and (360 ± 51) ng/L, the relative mRNA expressions were 2.4 ± 1.0 and 11.8 ± 2.9, the relative mRNA expressions were 2.9 ± 0.6 and 6.7 ± 1.0 (t = 4.055 to 10.406, P < 0.05). Compared with the control group, the infiltration of inflammation, the injury of elastic fibers in the vessel wall, and the positive expression of MMP-2 and 9 protein of the experiment group were all reduced. CONCLUSIONS: Saturated hydrogen saline prevents the degradation of elastin in vessel wall and ameliorates the formation and development of AAA, which may be associated with its anti-inflammatory effects, thereby reduces the MMP-2 and 9 mRNA and protein expression.

HSP70 and GRP78 induced by endothelin-1 pretreatment enhance tolerance to hypoxia in cultured neonatal rat cardiomyocytes.

The heat shock protein 70 and glucose-regulated protein 78 have been shown to protect cells against deleterious stimuli. This study was performed to determine whether endothelin-1 pretreatment could increase cardiomyocyte tolerance to hypoxia and induce heat shock protein 70 and glucose-regulated protein 78 expression. Cultured cardiomyocytes were treated with endothelin-1 at doses of 0.01, 0.1 and 1.0 nmol/L for 10 minutes followed by 10 minutes endothelin-1-free normal medium prior to 12 hours hypoxia. Lactate dehydrogenase activity and malondialdehyde level in the medium were determined at the end of hypoxia, and myocyte heat shock protein 70 and glucose-regulated protein 78 were assayed with Western blot. Lactate dehydrogenase activity and malondialdehyde content in the medium were significantly elevated after hypoxia (P < 0.01, n = 6). Heat shock protein 70 and glucoseregulated protein 78 expression in cardiomyocytes also increased significantly after hypoxia (P < 0.01 vs control, n = 3). Endothelin- 1 pretreatment reduced lactate dehydrogenase and malondialdehyde after hypoxia, and increased heat shock protein 70 and glucoseregulated protein 78 levels during normal culture and hypoxia. Glucose-regulated protein 78 antisense oligodeoxynucleotide partially abrogated the protective effect of endothelin-1 pretreatment on hypoxic cardiomyocyte injury. This study indicated that endothelin-1 pretreatment could protect hypoxic cardiomyocytes and might exert this effect through upregulation of heat shock protein 70 and glucose-regulated protein 78.

[Effect of urotensin II on the nitric oxide production in neonatal rat cardiomyocytes].

The aim of this study was to investigate the effect of urotensin II (U II) on the nitric oxide (NO) production in cultured neonatal rat cardiomyocytes. The endothelial nitric oxide synthase (eNOS) mRNA expression was assessed by semi-quantitative reverse transcription-polymerase chain reaction. The activity of nitric oxide synthase (NOS) and NO content in cardiomyocytes were measured. The current results showed that U inhibited eNOS mRNA expression, the NOS activity and the NO production of cardiomyocytes. U II (0.1 micromol/L) inhibited the NOS activity and the NO production in cardiomyocytes in a time-dependent manner. These results suggest that the cardiovascular effect of U II might be partially associated with NO production in cultured neonatal rat cardiomyocytes.

Transcript profiling analysis of in vitro cultured THP-1 cells after exposure to crotonaldehyde.

Crotonaldehyde, a highly toxic α, ß-unsaturated aldehyde, is a major component of cigarette smoke and a ubiquitous environmental pollutant. Crotonaldehyde exposure is known to have adverse effects on respiratory health, but the underlying mechanisms remain obscure. As alveolar macrophages display important immunological and inflammatory properties in response to extraneous substances in the lung, we aimed at gaining more insight in changes of human macrophage-like cells transcriptome in response to crotonaldehyde. In vitro cultures of human THP-1 cells (a human monocytic leukemia cell line) were differentiated into macrophage-like cells treated by PMA (phorbol 12-myristate 13-acetate) and be exposed crotonaldehyde. Using RNA-seq technology such as digital gene expression, the global changes in transcriptional level were analyzed. Real-time quantitative polymerase chain reaction (qPCR) was performed to validate RNA-seq data. The differential regulated genes in many biological processes were dysregulated, including in antigen processing and presentation, oxidative stress, inflammation, cytokine signaling, and apoptosis. Collectively, our study demonstrated that crotonaldehyde altered gene expression profile in the genome-wide transcriptional level in human macrophage-like cells, and many of them may represent potential mechanisms of crotonaldehyde causing cytotoxicity and tissue injury in the human lung.

Crotonaldehyde induces apoptosis and immunosuppression in alveolar macrophages.

Crotonaldehyde, a highly toxic α, ß-unsaturated aldehyde, is a major component of cigarette smoke (CS) and a ubiquitous environmental pollutant. Exposure to crotonaldehyde-rich pollutants such as CS is associated with suppression of respiratory host defense against infections. The aim of this study was to evaluate the apoptotic and immunological effects of crotonaldehyde exposure in a rat alveolar macrophage (AM) cell line, NR8383. Our studies showed that crotonaldehyde induced AM cell death mainly via the apoptotic process. Crotonaldehyde also decreased the phagocytic activity of AMs. Crotonaldehyde caused inhibition of NO, TNF-α, IL-1ß and IL-12 production in AMs treated with lipopolysaccharide (LPS), which is probably related to inhibition of NF-κB activation. These results indicate that crotonaldehyde can cause adverse effects in AMs via multiple mechanisms, and may contribute to compromised lung immunological response in smokers.

Crotonaldehyde-exposed macrophages induce IL-8 release from airway epithelial cells through NF-κB and AP-1 pathways.

Crotonaldehyde, a highly toxic α, ß-unsaturated aldehyde, is a major component of cigarette smoke and a ubiquitous environmental pollutant. Crotonaldehyde exposure is known to have adverse effects on respiratory health, but the underlying mechanisms remain obscure. To examine the interaction between macrophages and airway epithelial cells after exposure to crotonaldehyde, BEAS-2B and A549 cells were treated with conditioned media from a human monocytic leukemia cell line (THP-1) cells stimulated with crotonaldehyde. We demonstrate that conditioned media from THP-1 cells stimulated with crotonaldehyde increased interleukin (IL)-8 production, enhanced nuclear factor (NF)-κB and AP-1 DNA-binding activity in BEAS-2B and A549 cells. Analysis of these conditioned media revealed marked increases in tumor necrosis factor (TNF)-α, IL-1ß and IL-8 levels. Preincubation of conditioned media with either TNF-α- or IL-1ß-neutralizing antibodies reduced IL-8 production. Furthermore, BEAS-2B and A549 cells directly treated with crotonaldehyde induced increase in IL-8 production. These data suggest that crotonaldehyde is capable of directly stimulating the production of IL-8 in both macrophages and airway epithelial cells. Crotonaldehyde-stimulated macrophages also amplify the inflammatory response by enhancing IL-8 release from airway epithelial cells mediated by NF-κB and AP-1 pathways through a mechanism involving TNF-α and IL-1ß. These findings indicate that crotonaldehyde can cause lung inflammatory response via multiple mechanisms, and may contribute to chronic airway inflammation in smokers.

Crotonaldehyde induces apoptosis in alveolar macrophages through intracellular calcium, mitochondria and p53 signaling pathways.

Crotonaldehyde, a highly electrophilic α, ß-unsaturated aldehyde, is a ubiquitous environmental pollutant and a risk factor for multiple respiratory diseases. Crotonaldehyde is highly volatile and hydrophilic, so it is efficiently absorbed in the respiratory tract. Alveolar macrophages are major effector cells of the nonspecific host defence in the lung. The aim of this study was to investigate the molecular mechanisms and signaling pathways responsible for cell death of alveolar macrophage induced by crotonaldehyde. Our results show that crotonaldehyde induces apoptosis in alveolar macrophages, as indicated by phosphatidylserine externalization and DNA fragmentation. Pretreatment of alveolar macrophages with N-acetylcysteine, ascorbic acid, α-tocopherol, superoxide dismutase inhibited crotonaldehyde-induced apoptosis. Crotonaldehyde-induced apoptosis was characterized by ROS generation, GSH depletion, loss of mitochondrial membrane potential (ΔΨm), the release of cytochrome c from mitochondria, caspase-3/7 and caspase-9 activation, elevation of intracellular Ca(2+) concentration and the increase of p53 expression. Furthermore, pretreatment with either p53 inhibitor pifithrin-α or calcium chelator BAPTA-AM effectively attenuated apoptosis induced by crotonaldehyde. Taken together, our results showed that crotonaldehyde induce apoptosis in alveolar macrophages through intracellular calcium, mitochondria and p53 signaling pathways. These results would help to illustrate the mechanism of toxicity induced by crotonaldehyde and to look for a novel treatment for diseases induced by exposure to crotonaldehyde-rich pollutants such as cigarette smoke.

[Effects of long-term intervention of moxa smoke on T lymphocyte subsets and CD4+ CD25+ Treg in peripheral blood of Wistar rats].

OBJECTIVE: To investigate the cellular immune regulation of the long-term intervention of moxa smoke. METHODS: Thirty-two Wistar rats were randomly divided into a blank group, a low concentration group, a medium concentration group and a high concentration group, 8 cases in each group. In addition to the blank group, rats in the other groups were exposed to the corresponding concentration moxa smoke for 20 min every day, the T lymphocyte subsets and proportion of the CD4+ CD25+ Treg in CD4+ T cells in peripheral blood were tested by flow cytometry after 6 months. RESULTS: Compared with the blank group, the proportions of CD3+ CD4+, CD3+ CD8+ T cells and CD3+ CD4/CD3+ CD8+ in the other 3 moxa smoke groups were not significantly different (P > 0.05), while the proportions of the CD4+ CD25+ Treg in CD4+ T cells were significantly lower (P < 0.05), but no statistically significant differences among those 3 moxa smoke intervention groups (P > 0.05). CONCLUSION: Long-term moxa smoke intervention has no significant effect on the proportions of CD3+ CD4+, CD3+ CD8+ T cells and CD3+ CD4+/CD3+ CD8+, but it can decrease the proportions of the CD4+ CD25+ Treg in CD4+ T cells in peripheral blood of rats. The way produced by pretreatment with moxa smoke may play immunomodulatory effect.

Inhibition of cyclooxygenase-2 by tetramethylpyrazine and its effects on A549 cell invasion and metastasis.

Cyclooxygenase (COX)-2 plays an important role in tumorigenesis and has been implicated to be a critical factor for invasion and metastasis of lung cancer. Tetramethylpyrazine (TMP), an effective component of the traditional Chinese medicine Chuanxiong, has been traditionally used in treating neurovascular and cardiovascular diseases. Recently TMP has been reported to have beneficial effect in cancer patients. However, the function and the mechanism of TMP in lung cancer have not been elucidated to date. In this study, we investigated the in vitro and in vivo effect of TMP in tumorigenesis and whether COX-2 is a molecular target of TMP. We showed that TMP exhibited a dose- and time-dependent inhibition on A549 cell proliferation by suppressing cell cycle progression. In vitro treatment of A549 cells with TMP resulted in a significant inhibition of invasion, associated with reduced activities of COX-2 and MMP-2/TIMP-2. Furthermore, in vivo experiments showed that TMP significantly suppressed metastatic growth of A549 cells and COX-2 expression in metastatic nude mouse model. This preclinical study provides the first evidence for the novel anti-tumor effects of TMP as a COX-2 pathway inhibitor in human adenocarcinoma cell line A549. These studies suggest that TMP may serve as an effective agent for the treatment and chemoprevention of non-small cell lung cancer.

The effect of human antibacterial peptide LL-37 in the pathogenesis of chronic obstructive pulmonary disease.

BACKGROUND: Previous research has shown that innate immune system was more important than the acquired immune system in the pathogenesis of COPD. LL-37 is the only human cathelicidin identified so far. As an integral part of the innate immune system, besides antibacterial activity, its chemotactic activity, damage repairing, influencing apoptosis and its cytotoxicity are attracting people's attention. The aim of the present study was to evaluate role of LL-37 in the pathogenesis of COPD. METHODS: ELISA and immunohistochemistry were applied to investigate the expression of LL-37 in induced sputum and lung tissue of COPD patients. Bronchial epithelial cell (BEP2D) and alveolar epithelial cell (A549) were treated with LL-37 synthesis polypeptide in vitro to assess the role of LL-37 in inflammation and apoptosis. RESULTS: We found that increased induced sputum levels of LL-37 in COPD patients were associated with airflow limitation, health status and exercise tolerance and the expressing intensity of LL-37 in both airway district and pulmonary alveoli area in COPD group significantly increased compared with control group. Through stimulation by CSE and LPS, the expression of LL-37 was increased in bronchial epithelial cell and alveolar epithelial cell. LL-37 synthesis polypeptide can promote the releasing of inflammatory factor IL-8 and induce apoptosis of bronchial epithelial cell and alveolar epithelial cell. CONCLUSION: This study suggested that LL-37 may play important role in the pathogenesis of COPD and may be a possible novel therapeutic target in COPD.

Gene expression profile and cytotoxicity of human bronchial epithelial cells exposed to crotonaldehyde.

Crotonaldehyde is an environment pollutant and lipid peroxidation product. Crotonaldehyde produces adverse effects to humans and serves as a risk factor for human pulmonary diseases. Like acrolein and 4-hydroxynonenal, crotonaldehyde seems likely to alter many cell signaling cascades, including inflammatory responses. The purpose of this study was to investigate the genome-wide transcriptional responses of normal human bronchial epithelial cells exposed to crotonaldehyde. Using microarrays technology, the global changes in transcriptional level were analyzed. Prior to RNA extraction, cells were exposed to crotonaldehyde at 40 or 80 microM for 3 or 6h. Real-time quantitative polymerase chain reaction (qPCR) was performed to validate microarray data and cell cycle arrest was determined. The commonly differentially regulated genes in many biological processes were dysregulated including inflammatory responses, exogenous metabolism, cell cycle, heat shock responses, and antioxidant responses. Results in the present study screen out the important roles of HMOX1 in regulating other signaling cascades and ALDH1A3 in detoxifying exogenous toxicants. Collectively, our study demonstrated that crotonaldehyde altered gene expression profile in the genome-wide transcriptional level in normal human bronchial epithelial cells. And many of them represented potential mechanisms of crotonaldehyde causing cytotoxicity and tissue injury in the human lung.

Thrombin promotes human lung fibroblasts to proliferate via NADPH oxidase/reactive oxygen species/extracellular regulated kinase signaling pathway.

BACKGROUND: Thrombin is a multifunctional serine protease that plays a crucial role in hemostasis following tissue injury. In addition to its procoagulation effect, thrombin is also a potent mesenchymal cell mitogen, therefore it plays important roles in the local proliferation of mesenchymal cells in the tissue repair process. Reactive oxygen species (ROS) can induce some human cells to proliferate at lower rates while at higher concentrations they promote cells to undergo apoptosis or necrosis. Accumulative evidence suggests that thrombin can induce some cells to produce ROS. Based on these observations, we provide a hypothesis that thrombin can stimulate human lung fibroblasts to produce ROS, which play an important role in human lung fibroblast proliferation. METHODS: ROS were detected in fibroblasts at 30 minutes and 60 minutes following thrombin (20 U/ml) exposure using flow cytometry. The ratio of reduced glutathione/oxidized glutathione (GSH/GSSG) was assayed in lung fibroblasts using a commercial kit following treatment with thrombin at different concentrations. NADPH oxidase and the extracellular regulated kinase1/2 (ERK1/2) signaling pathway were detected by Western blotting after thrombin stimulation to lung fibroblasts. RESULTS: Thrombin, at 20 U/ml, stimulated human lung fibroblasts (HLF) to generate ROS in a time dependent manner. The ratio of GSH/GSSG in fibroblasts treated with thrombin showed a significant decrease. NADPH oxidase was activated and the ERK1/2 signal pathway was involved in the proliferation process of fibroblasts treated with thrombin. CONCLUSION: The activation of NADPH oxidase by thrombin leads to the production of ROS, which promotes fibroblasts proliferation via activation of the ERK1/2 signaling pathway.

Crotonaldehyde induces oxidative stress and caspase-dependent apoptosis in human bronchial epithelial cells.

Crotonaldehyde is a widespread environmental pollutant and lipid peroxidation product. Crotonaldehyde is a risk factor for many diseases (e.g., chronic pulmonary inflammation). However, its toxicity and its mechanism of action have not been thoroughly investigated. The purpose of this study is to investigate crotonaldehyde-induced oxidative stress and mechanism of cell death in BEAS-2B cells. Crotonaldehyde caused decreases of intracellular reduced glutathione levels and increases of reactive oxygen species in a dose-dependent manner. Crotonaldehyde induced cell death by apoptosis, and gradually transitioned to necrosis at high dose of crotonaldehyde, as demonstrated by Annexin V-FITC/PI staining and cell morphology analysis. Crotonaldehyde-induced ATP decline observed in the study might partially account for the switch from apoptosis to necrosis. Mitochondria membrane potential, cytochrome c release, caspase-9, and caspase-3/7 activity were investigated, and the results suggest that crotonaldehyde-induced apoptosis was activated in a caspase-dependent way. Collectively, these results demonstrate crotonaldehyde induces cell oxidative stress and caspase-dependent apoptosis.

Radiosensitization and growth inhibition of cancer cells mediated by an scFv antibody gene against DNA-PKcs in vitro and in vivo.

BACKGROUND: Overexpression of DNA-dependent protein kinase catalytic subunit (DNA-PKcs) is commonly occurred in cancers and causes radioresistance and poor prognosis. In present study, the single-chain variable antibody fragments (scFv) targeting DNA-PKcs was developed for the application of radiosensitization in vitro and in vivo. A humanized semisynthetic scFv library and the phage-display antibodies technology were employed to screen DNA-PKcs scFv antibody. METHODS: DNA-PKcs epitopes were predicted and cloned. A humanized semisynthetic scFv library and the phage-display antibodies technology were employed to screen DNA-PKcs scFv antibody. DNA damage repair was analyzed by comet assay and immunofluorescence detection of gammaH2AX foci. The radiosensitization in vivo was determined on Balb/c athymic mice transplanted tumours of HeLa cells. RESULTS: Four epitopes of DNA-PKcs have been predicted and expressed as the antigens, and a specific human anti-DNA-PKcs scFv antibody gene, anti-DPK3-scFv, was obtained by screening the phage antibody library using the DNA-PKcs peptide DPK3. The specificity of anti-DPK3-scFv was verified, in vitro. Transfection of HeLa cells with the anti-DPK3-scFv gene resulted in an increased sensitivity to IR, decreased repair capability of DNA double-strand breaks (DSB) detected by comet assay and immunofluorescence detection of gammaH2AX foci. Moreover, the kinase activity of DNA-PKcs was inhibited by anti-DPK3-scFv, which was displayed by the decreased phosphorylation levels of its target Akt/S473 and the autophosphorylation of DNA-PKcs on S2056 induced by radiation. Measurement of the growth and apoptosis rates showed that anti-DPK3-scFv enhanced the sensitivity of tumours transplanted in Balb/c athymic mice to radiation therapy. CONCLUSION: The antiproliferation and radiosensitizing effects of anti-DPK3-scFv via targeting DNA-PKcs make it very appealing for the development as a novel biological radiosensitizer for cancer therapeutic potential.

Alteration of transcriptional profile in human bronchial epithelial cells induced by cigarette smoke condensate.

Despite the significance of cigarette smoke for carcinogenesis, the molecular mechanisms that lead to increased susceptibility of human cancers are not well-understood. In our present study, the oncogenic transforming effects of cigarette smoke condensate (CSC) were examined using papillomavirus-immortalized human bronchial epithelial cells (BEP2D). Growth kinetics, saturation density, resistance to serum-induced terminal differentiation, anchorage-independent growth and tumorigenicity in nude mice were used to investigate the various stages of transformation in BEP2D cells. Illumina microarray platforms were used to explore the CSC-induced alteration of global mRNA expression profiles of the earlier period and the advanced stage of CSC-treated BEP2D cells. We showed here that a series of sequential steps arose among CSC-treated immortalized human bronchial epithelial cells, including altered growth kinetics, resistance to serum-induced terminal differentiation, and anchorage-independence growth. In the earlier period of CSC treatment, 265 genes were down-regulated and 63 genes were up-regulated, respectively, and in the advanced stage of CSC treatment, 313 genes were down-regulated and 145 genes were up-regulated, respectively. Notably, among those genes, the expression of some of imprinted genes such as IGF2, NDN, H19 and MEG3 were all silenced or down-regulated in CSC-treated cells. These genes reactivated after 5 microM 5-aza-2-deoxycytidine (5-aza-dC) treatment. These results demonstrated that long-term treatment of human bronchial epithelial cells with CSC may adversely affect their genetic and epigenetic integrity and lead to further transformation.