Human Non-small Cell Lung Adenocarcinoma Research Articles

Effect of Extraction Solvent and Harvest Time on Recovery of Bioactive Com-pounds, Antioxidant and Cancer Cell Growth Inhibition Activities of Korean Ca-mellia mistletoe

This study aimed to determine the phytochemical profiles,in vitroantioxidant and antiproliferative properties of KoreanCamellia mistletoe(Korthalsella japon-ica(Thunb.) Engl.) depending on the harvest time (August and November) and sol-vent (100% methanol, 70% ethanol, and hot water). TheCamellia japonicaL. mistle-toe extracts were analyzed for total phenol, flavonoid, carotenoid, and L-ascorbic acid contents and antioxidant properties such as scavenging capacities (1,1-diphenyl-2-pic-rylhydrazyl (DPPH) and NO•),ferrous ion chelating and reducing power. Concur-rently, the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) as-say was used to assess the antiproliferative properties against human cancer cell lines; MCF (human breast cancer cells), HeLa (human cervical cancer cells), A375 (human malignant melanoma cells), HCT116 (human colon cancer cells), HepG2 (human liver cancer cells) and A549 (human non-small cell lung adenocarcinoma cells). The results showed that extraction solvent and harvest time had significant impacts on antioxidant and anticancer activities and selectivity for free phenolic compounds inCamellia ja-ponicaL. mistletoe. Among all the tested extracts, the highest amounts of total phe-nolic and total flavonoids content were found in ethanol extracts ofCamellia japon-icaL. mistletoe harvested in November, while the methanol extracts ofCamellia ja-ponicaL. mistletoe collected in August showed the highest contents of total carote-noids and L-ascorbic acidscompared to the other tested extracts. Additionally, the highest NO•radical scavenging activity was found in ethanol extracts, whereas the strongest DPPH radical scavenging activity was found in methanol extracts ofCamel-lia japonicaL. mistletoe harvested in November. Furthermore, methanol extracts showed much higher antiproliferative activity against all human cancer cells than eth-anol extracts ofCamellia japonicaL. mistletoe harvested in November. In conclusion, the antioxidant and anticancer properties ofCamellia japonicaL. mistletoe showed significant dependence on the extraction solvent type and harvest time. With optimum harvest time and extraction solvent, they boast a wide range of promising medical, pharmaceutical, and food applications

Cytotoxicity and acute toxicity evaluation of hydrogen-rich Gynostemma pentaphyllum Makino distillate

Hydrogen-rich Gynostemma pentaphyllum Makino distillate (HRGD) consists of Gynostemma pentaphyllum Makino steam distillate with hydrogen gas. Although both G. pentaphyllum Makino and hydrogen-rich water are well known for their biological and medical benefits, there is a lack of information on their safety and toxicity in vivo acute oral toxicity test and in vitro cytotoxicity method. The current study aimed to assess the cytotoxicity and acute oral toxicity of HRGD as a part of a safety evaluation using rat and human cell models. HRGD was administered orally once by gavage to male and female Sprague-Dawley rats at doses of 0, 2500, and 5000 mg/kg. Cytotoxicity assay was conducted in vitro at various concentrations in 10 different human normal and cancer cell lines; TK6 (human normal lymphomablastoid cells), Chang (human hepatic cells), 16HBE14o- (human bronchial epithelial cells), URotsa (human urothelium cells), MCF (human breast cancer cells), Hela (human cervical cancer cells), A375 (human malignant melanoma cells), HCT116 (human colon cancer cells), HepG2 (human liver cancer cells) and A549 (human non-small cell lung adenocarcinoma cells). From a 14-day study in rats, we observed no compound-related changes in mortality, clinical signs, body weight, food/water consumption, organ weight and gross pathology in all dose group. The result of in vivo acute toxicity shows that no observed adverse effect level of HRGD was below 5000 mg/kg for both sexes of rats, and the minimal lethal dose was considered to be more than 5000 mg/kg. HRGD also had no in vitro cytotoxicity against all tested cells. The present study data indicated that HRGD may contain bioactive compounds of potential therapeutic significance that are relatively safe from toxic effects.

Dimethoxycurcumin Acidifies Endolysosomes and Inhibits SARS-CoV-2 Entry

The pandemic of coronavirus disease 2019 (COVID-19) caused by infection by severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) continues to take a huge toll on global health. Although improving, currently there are only limited therapies against SARS-CoV-2. Curcumin, a natural polyphenol, exerts antiviral effects against a wide variety of viruses and can inhibit SARS-CoV-2 entry. However, undesirable physicochemical and pharmacokinetic properties of curcumin limit its clinical application. Here, we determined the effects of dimethoxycurcumin (DiMC), a methylated analog of curcumin with improved bioavailability, on the entry of SARS-CoV-2. DiMC blocked entry of pseudo-SARS-CoV-2 into Calu-3 human non-small cell lung adenocarcinoma cells and Vero E6 green monkey kidney epithelial cells. Mechanistically, DiMC acidified lysosomes, enhanced lysosome degradation capabilities, and promoted lysosome degradation of angiotensin converting enzyme 2 (ACE2), a major receptor for SARS-CoV-2 entry, as well as pseudo-SARS-CoV-2 and the SARS-CoV-2 S1 protein. Furthermore, other lysosome acidifying agents, including the TRPML1 agonist ML-SA1 and the BK channel activator NS1619, also blocked the entry of pseudo-SARS-CoV-2. Thus, the anti-SARS-CoV-2 potential of DiMC and lysosome acidifying agents might be explored further as possible effective therapeutic strategies against COVID-19.

The mitochondrial fission factor FIS1 promotes stemness of human lung cancer stem cells via mitophagy.

Mitophagy, a form of autophagy, plays a role in cancer development, progression and recurrence. Cancer stem cells (CSCs) also play a key role in these processes, although it not known whether mitophagy can regulate the stemness of CSCs. Here, we employed the A549‐SD human non‐small cell lung adenocarcinoma CSC model that we have developed and characterized to investigate the effect of mitophagy on the stemness of CSCs. We observed a positive relationship between mitophagic activity and the stemness of lung CSCs. At the mechanistic level, our results suggest that augmentation of mitophagy in lung CSCs can be induced by FIS1 through mitochondrial fission. In addition, we assessed the clinical relevance of FIS1 in lung adenocarcinoma using The Cancer Genome Atlas database. An elevation in FIS1, when observed together with other prognostic markers for lung cancer progression, was found to correlate with shorter overall survival.

Investigation of in vitro activities of Cu2ZnSnS4 nanoparticles in human non-small cell lung cancer

Cu2ZnSnS4 (CZTS) nanoparticles (NPs) were prepared by a simple hydrothermal method, and their cytotoxic, antiproliferative and proapoptotic activities on human non-small cell lung adenocarcinoma A549 cells were investigated for the first time, and the morphological and ultrastructural changes of these cells were monitored. The structural characterizations of the synthesized nanoparticles were made by using Field Emission-Scanning Electron Microscope (FE-SEM), X-Ray Powder Diffraction (XRD) and Raman techniques. Cytotoxicity and confocal microscopy studies revealed that the CZTS NPs effectively entered into the A549 cells in a dose-dependent not time-dependent manner over a period of 24 and 48 h. It was observed that the CZTS NPs had a negligible cytotoxic effect and considerable antiproliferative and proapoptotic activities. The low cytotoxicity of the CSTZ NPs and their potent anticancer activity against A549 cells highlight their potential to be used as anticancer agents. This study may pave the way for designing and constructing various morphologically diverse, nanotextured materials with desired functional attributes.

Aclarubicin in subtoxic doses reduces doxorubicin cytotoxicity in human non-small cell lung adenocarcinoma (A549) and human hepatocellular carcinoma (HepG2) cells by decreasing DNA damage

In the study, the cytotoxicity and genotoxicity of aclarubicin (ACL) against A549 (human non-small cell lung adenocarcinoma) and HepG2 (human hepatocellular carcinoma) cell lines were evaluated and compared with that of doxorubicin (DOX). The effect of both anthracyclines in combination was also investigated. In order to get a deeper insight into the effectiveness of the drugs and their combination, their effects on the DNA damage and distribution of the cell cycle of A549 and HepG2 cells were investigated. After treatment with investigated compounds, apoptotic and necrotic morphological changes were estimated by double staining cells with orange acridine and ethidium bromide.The results showed that ACL was much more cytotoxic against lung (A549) and liver (HepG2) cancer cell lines than DOX. However, the drugs affected the cell cycle differently. ACL arrested cells in the G1 phase, while DOX arrested them in the G2/M phase. DOX and ACL at high concentrations are able to trigger apoptosis in both A549 and HepG2 cells. When the drugs were used in combination, subtoxic concentrations of ACL antagonized the cytotoxic effects of doxorubicin. Pre-incubation of cells with subtoxic concentrations of ACL reduced the level of DNA damage by DOX but increased DOX genotoxicity in the presence of verapamil.

Crizotinib induces apoptosis of lung cancer cells through JAK-STAT pathway.

Effect of crizotinib on apoptosis of lung cancer cells was investigated. Human non-small cell lung adenocarcinoma H2228 cells were cultured in the presence of 0, 20, 40, 80, 160 and 320 nmol/l of crizotinib for 3 days, respectively. The inhibition rate of cell proliferation was measured by MTT assay, and half maximal inhibitory concentration (IC50) was calculated. Cell apoptosis was detected by flow cytometry. Transwell assay was performed to detect cell migration. Expression of Janus protein tyrosine kinase (JAK) and signal transducer and activator of transcription (STAT) proteins was detected by western blot analysis. Crizotinib significantly inhibited the proliferation of human lung cancer H2228 cells, and the inhibitory effect was enhanced with the increase of the concentration of crizotinib (p<0.01). The IC50 value was 311.26 nnol/l. According to IC50 value, concentration of crizotinib at 300 nmol/l was selected for the study. It was found that crizotinib at 300 nmol/l significantly promoted cell apoptosis (p<0.01) and inhibited cell migration (p<0.01). Compared with pretreatment levels, crizotinib downregulated the expression of JAK and STAT (p<0.01) on the 1st day of treatment, but with the prolongation of time, no further significant difference was observed on the 1st, 2nd or 3rd day in the level of JAK protein (p=0.47); there were no statistically significant differences in the level of STAT protein (p=0.91). Crizotinib can inhibit the migration and promote cell apoptosis of human lung cancer cell line H2228 by regulating the expression of JAK and STAT proteins in JAK-STAT signaling pathway.

A Synthetic Analogue of Neopeltolide, 8,9-Dehydroneopeltolide, Is a Potent Anti-Austerity Agent against Starved Tumor Cells.

Neopeltolide, an antiproliferative marine macrolide, is known to specifically inhibit complex III of the mitochondrial electron transport chain (mETC). However, details of the biological mode-of-action(s) remain largely unknown. This work demonstrates potent cytotoxic activity of synthetic neopeltolide analogue, 8,9-dehydroneopeltolide (8,9-DNP), against starved human pancreatic adenocarcinoma PANC-1 cells and human non-small cell lung adenocarcinoma A549 cells. 8,9-DNP induced rapid dissipation of the mitochondrial membrane potential and depletion of intracellular ATP level in nutrient-deprived medium. Meanwhile, in spite of mTOR inhibition under starvation conditions, impairment of cytoprotective autophagy was observed as the lipidation of LC3-I to form LC3-II and the degradation of p62 were suppressed. Consequently, cells were severely deprived of energy sources and underwent necrotic cell death. The autophagic flux inhibited by 8,9-DNP could be restored by glucose, and this eventually rescued cells from necrotic death. Thus, 8,9-DNP is a potent anti-austerity agent that impairs mitochondrial ATP synthesis and cytoprotective autophagy in starved tumor cells.

Assessment of tumour viability in human lung cancer xenografts with texture-based image analysis

AimsTo build and evaluate an automated method for assessing tumour viability in histological tissue samples using texture features and supervised learning.MethodsH&E-stained sections (n=56) of human non-small cell lung adenocarcinoma xenografts...

Cytotoxic and anti-angiogenic effects of lanostane triterpenoids from Ganoderma lucidum

Two new lanostane triterpenes, 3α,12β,15α-triacetoxy-5α-lanosta-7,9(11),24-trien-26-oic acid (1) and 5α-lanosta-8,24-diene-26,27-dihydroxy-3,7-dione (2), together with sixteen known compounds (3–18) were isolated from the fruiting bodies of the Vietnamese mushroom Ganoderma lucidum. Their chemical structures were determined by extensive spectroscopic (IR, HR-EI-MS, 1D and 2D NMR) analyses. Potential cytotoxic activities of these compounds were evaluated against human non-small cell lung adenocarcinoma (A549), breast adenocarcinoma (MCF-7), and prostatic small cell carcinoma (PC-3). Among the compounds, 3α,12β,15α-triacetoxy-5α-lanosta-7,9(11),24-trien-26-oic acid (1) showed significant cytotoxic activity against PC-3 cells with an IC50 of 11.5μM. In studies of anti-angiogenesis activity, ganoderic acid F (17) was found to have the most potent inhibitory effect on the formation of capillary-like structures of human umbilical vein endothelial cells.

Human neural stem cells expressing carboxyl esterase target and inhibit tumor growth of lung cancer brain metastases

Neural stem cells (NSCs) led to the development of a novel strategy for delivering therapeutic genes to brain tumors. Human NSCs expressing rabbit carboxyl esterase (F3.CE), which activates CPT-11, significantly inhibit the growth of A549 human non-small cell lung adenocarcinoma cells in the presence of CPT-11 in vitro and in vivo. F3.CE cells migrated selectively into the brain metastases located in the opposite hemisphere. The treatment also significantly decreased tumor volume in immune-deficient mice bearing lung cancer when F3.CE cells were transplanted into the contralateral hemisphere. The survival of tumor-bearing animals was significantly prolonged by the treatment with F3.CE and CPT-11. This strategy could be considered as an effective treatment regimen for lung cancer brain metastases.

Cytotoxic activities of [Ser49]phospholipase A2 from the venom of the saw-scaled vipers Echis ocellatus, Echis pyramidum leakeyi, Echis carinatus sochureki, and Echis coloratus

Fractionation by reversed-phase HPLC of venom from four species of saw-scaled viper: Echis ocellatus, Echis pyramidum leakeyi, Echis carinatus sochureki, and Echis coloratus led to identification in each sample of an abundant protein with cytotoxic activity against human non-small cell lung adenocarcinoma A549 cells. The active component in each case was identified by MALDI-TOF mass fingerprinting of tryptic digests as [Ser49]phospholipase A2 ([Ser49]PLA2). An isoform of [Ser49]PLA2 containing the single Ala18 → Val substitution and a partially characterized [Asp49]PLA2 were also present in the E. coloratus venom. LC50 values against A549 cells for the purified [Ser49]PLA2 proteins from the four species are in the range 2.9–8.5 μM. This range is not significantly different from the range of LC50 values against human umbilical vein endothelial HUVEC cells (2.5–12.2 μM) indicating that the [Ser49]PLA2 proteins show no differential anti-tumor activity. The LC50 value for [Ser49]PLA2 from E. ocellatus against human erythrocytes is >100 μM and the MIC values against Escherichia coli and Staphylococcus aureus are >100 μM. It is suggested that the [Ser49]PLA2 proteins play a major role in producing local tissue necrosis and hemorrhage at the site of envenomation.

Esculentin-2CHa: A host-defense peptide with differential cytotoxicity against bacteria, erythrocytes and tumor cells

The host-defense peptide, esculentin-2CHa (GFSSIFRGVA10KFASKGLGK D20LAKLGVDLVA30 CKISKQC) shows potent (MIC≤6μM) growth inhibitory activity against clinical isolates of multidrug-resistant strains of Staphylococcus aureus, Acinetobacter baumannii, and Stenotrophomonas maltophilia and differential cytotoxic activity against human erythrocytes (LC50=150μM) and human non-small cell lung adenocarcinoma A549 cells (LC50=10μM). Esculentin-2CHa significantly (P<0.01) stimulates the release of the anti-inflammatory cytokine IL-10 by mouse lymphoid cells and elevates its production after stimulation with concanavalin A and significantly (P<0.05) stimulates TNF-α production by peritoneal macrophages. Effects on IL-6 and IL-1β production were not significant. Removal of the hydrophobic N-terminal hexapeptide (GFSSIF) from esculentin-2CHa results in abolition of growth inhibitory activity against S. aureus and cytotoxic activity against erythrocytes and A549 cells as well as a marked (≥16-fold) reduction in potency against A. baumannii and S. maltophilia. The primary structure of esculentin-2 has been poorly conserved between frog species but evolutionary pressure has acted to maintain the hydrophobic character of this N-terminal hexapeptide sequence. Removal of the cyclic C-terminal domain (CKISKQC) and replacement of the Cys31 and Cys37 residues by serine resulted in appreciable decreases in cytotoxicity against all microorganisms and against mammalian cells. The more cationic [D20K, D27K] analog showed a modest increase in potency against all microorganisms (up to 4-fold) but a marked increase in cytotoxicity against erythrocytes (LC50=11μM) and A549 cells (LC50=3μM).

Non-small cell lung cancer stem/progenitor cells are enriched in multiple distinct phenotypic subpopulations and exhibit plasticity

Cancer stem cells (CSCs) represent a population of cancer cells that possess unique self-renewal and differentiation characteristics required for tumorigenesis and are resistant to chemotherapy-induced apoptosis. Lung CSCs can be enriched by several markers including drug-resistant side population (SP), CD133pos and ALDHhigh. Using human non-small cell lung adenocarcinoma cell lines and patient-derived primary tumor cells, we demonstrate that SP cells represent a subpopulation distinct from other cancer stem/progenitor cell (CS/PC) populations marked by CD133pos or ALDHhigh. The non-CS/PCs and CS/PCs of each subpopulation are interconvertible. Epithelial-mesenchymal transition (EMT) promotes the formation of CD133pos and ALDHhigh CS/PC subpopulations while suppressing the SP CS/PC subpopulation. Rac1 GTPase activity is significantly increased in cells that have undergone EMT, and targeting Rac1 is effective in inhibiting the dynamic conversion of non-CS/PCs to CS/PCs, as well as the CS/PC activity. These results imply that various subpopulations of CS/PCs and non-CS/PCs may achieve a stochastic equilibrium in a defined microenvironment, and eliminating multiple subpopulations of CS/PCs and effectively blocking non-CS/PC to CS/PC transition, by an approach such as targeting Rac1, can be a more effective therapy.

Rac1 Targeting Suppresses Human Non-Small Cell Lung Adenocarcinoma Cancer Stem Cell Activity

The cancer stem cell (CSC) theory predicts that a small fraction of cancer cells possess unique self-renewal activity and mediate tumor initiation and propagation. However, the molecular mechanisms involved in CSC regulation remains unclear, impinging on effective targeting of CSCs in cancer therapy. Here we have investigated the hypothesis that Rac1, a Rho GTPase implicated in cancer cell proliferation and invasion, is critical for tumor initiation and metastasis of human non-small cell lung adenocarcinoma (NSCLA). Rac1 knockdown by shRNA suppressed the tumorigenic activities of human NSCLA cell lines and primary patient NSCLA specimens, including effects on invasion, proliferation, anchorage-independent growth, sphere formation and lung colonization. Isolated side population (SP) cells representing putative CSCs from human NSCLA cells contained elevated levels of Rac1-GTP, enhanced in vitro migration, invasion, increased in vivo tumor initiating and lung colonizing activities in xenografted mice. However, CSC activity was also detected within the non-SP population, suggesting the importance of therapeutic targeting of all cells within a tumor. Further, pharmacological or shRNA targeting of Rac1 inhibited the tumorigenic activities of both SP and non-SP NSCLA cells. These studies indicate that Rac1 represents a useful target in NSCLA, and its blockade may have therapeutic value in suppressing CSC proliferation and metastasis.

Growth and Metastases of Human Lung Cancer Are Inhibited in Mouse Xenografts by a Transition State Analogue of 5′-Methylthioadenosine Phosphorylase

The S-adenosylmethionine (AdoMet) salvage enzyme 5'-methylthioadenosine phosphorylase (MTAP) has been implicated as both a cancer target and a tumor suppressor. We tested these hypotheses in mouse xenografts of human lung cancers. AdoMet recycling from 5'-methylthioadenosine (MTA) was blocked by inhibition of MTAP with methylthio-DADMe-Immucillin-A (MTDIA), an orally available, nontoxic, picomolar transition state analogue. Blood, urine, and tumor levels of MTA increased in response to MTDIA treatment. MTDIA treatment inhibited A549 (human non-small cell lung carcinoma) and H358 (human bronchioloalveolar non-small cell lung carcinoma cells) xenograft tumor growth in immunodeficient Rag2(-/-)γC(-/-) and NCr-nu mice. Systemic MTA accumulation is implicated as the tumor-suppressive metabolite because MTDIA is effective for in vivo treatment of A549 MTAP(-/-) and H358 MTAP(+/+) tumors. Tumors from treated mice showed increased MTA and decreased polyamines but little alteration in AdoMet, methionine, or adenine levels. Gene expression profiles of A549 tumors from treated and untreated mice revealed only modest alterations with 62 up-regulated and 63 down-regulated mRNAs (≥ 3-fold). MTDIA antitumor activity in xenografts supports MTAP as a target for lung cancer therapy.

The Cell Line Secretome, a Suitable Tool for Investigating Proteins Released in Vivo by Tumors: Application to the Study of p53-Modulated Proteins Secreted in Lung Cancer Cells

Malignant processes such as metastasis, invasion, or angiogenesis are tightly dependent on the composition of the extracellular medium, which is itself affected by the release of proteins by the tumor cells. p53, a major tumor suppressor protein very frequently mutated and/or inactivated in cancer cells, is known to modulate the release of proteins by the tumor cells; however, while p53-modulated intracellular proteins have been extensively studied, little is known concerning their extracellular counterparts. Here, we characterized the p53-dependent secretome of a lung tumor model in vitro (H358 human nonsmall cell lung adenocarcinoma cell line with a homozygous deletion of p53) and demonstrate that the modulation of exported proteins can also be detected in vivo in the plasma of tumor-bearing mice. We used a clone of H358, stably transfected with a tetracycline-inducible wild-type p53-expressing vector. With the use of iTRAQ labeling and LC-MALDI-MS/MS analysis, we identified 909 proteins released in vitro by the cells, among which 91 are p53-modulated. Three proteins (GDF-15, FGF-19, and VEGF) were also investigated in H358/TetOn/p53 xenograft mice. The ELISA dosage on total tumor protein extracts confirmed the influence of p53 on the release of these proteins in vivo. Moreover, the GDF-15 concentration was measured in the plasma and its p53-dependent modulation was confirmed. To our knowledge, this is the first report establishing that the in vitro cell line secretome is reliable and reflects the extracellular release of proteins from tumor cells in vivo and could be used to identify putative tumor markers.

Regulation of Human Lung Adenocarcinoma Cell Migration and Invasion by Macrophage Migration Inhibitory Factor

Macrophage migration inhibitory factor (MIF) is expressed and secreted in response to mitogens and integrin-dependent cell adhesion. Once released, autocrine MIF promotes the activation of RhoA GTPase leading to cell cycle progression in rodent fibroblasts. We now report that small interfering RNA-mediated knockdown of MIF and MIF small molecule antagonism results in a greater than 90% loss of both the migratory and invasive potential of human lung adenocarcinoma cells. Correlating with these phenotypes is a substantial reduction in steady state as well as serum-induced effector binding activity of the Rho GTPase family member, Rac1, in MIF-deficient cells. Conversely, MIF overexpression by adenovirus in human lung adenocarcinoma cells induces a dramatic enhancement of cell migration, and co-expression of a dominant interfering mutant of Rac1 (Rac1(N17)) completely abrogates this effect. Finally, our results indicate that MIF depletion results in defective partitioning of Rac1 to caveolin-containing membrane microdomains, raising the possibility that MIF promotes Rac1 activity and subsequent tumor cell motility through lipid raft stabilization.

Multislice spiral computed tomography of an orthotopic severe combined immunodeficient mouse model for lung adenocarcinoma

Summary Background and Aim: In recent years, much research interest has been rightfully directed towards modelling human disease. The increasing demand of laboratory animals has led to a major impetus in small animal imaging. We evaluated the feasibility of using multislice spiral CT (MSCT) technology in a severe combined immunodeficiency (SCID) mouse model for non-small cell lung cancer. Materials and Methods: Mice (n = 14) were implanted orthotopically with the human non-small cell lung adenocarcinoma cell line A 549. Mice were scanned with MSCT and sacrificed 7 days (n = 3), 14 days (n = 3), and 21 days (n = 5) after tumor cell implantation, respectively. Histopathology was performed. Tumor size as revealed by imaging and pathology was correlated. A group of animals (n = 3) received anti-cancer treatment with seco-CBI-Q-galatoside. Those mice were scanned with MSCT 21 days after tumor implantation and sacrificed, and histopathologic work-up was performed. Results: A total of 14 mice with 14 macroscopically visible and 5 microscopically appreciable adenocarcinomas of the lung were examined. All macroscopically visible tumors were readily depicted with MSCT except from 2 lesions of 1 mm in diameter. MSCT accurately displayed the different tumor sizes in treated vs. non-treated animals. Discussion: MSCT proved to be a valuable tool for imaging of a murine lung cancer model. This evidences a potential use of this technology in small animal lung cancer imaging.

Persistent activation of ERK1/2 by lead acetate increases nucleotide excision repair synthesis and confers anti-cytotoxicity and anti-mutagenicity.

Lead, a possible human carcinogen, affects signal transduction pathways in many aspects, yet exhibits low mutagenicity in human cells. In this study, we explore whether signaling pathways including the four MAPKs and AKT affect DNA repair and mutagenicity in the exposure of mammalian cells to lead acetate [Pb(II)]. Pb(II) increased the phosphorylated ERK1/2 and phosphorylated AKT but not the phosphorylated ERK5, phosphorylated p38 and JNK activity in human non-small cell lung adenocarcinoma CL3 cells. The duration of ERK1/2 activation was much longer than AKT activation and these two signals were independently activated by Pb(II) in CL3 cells. Intriguingly, a MKK1/2 inhibitor PD98059 (25-50 micro M) markedly suppressed ERK1/2 activation and greatly promoted the hprt mutation frequency and cytotoxicity in Pb(II)-treated CL3 cells. Conversely, inhibition of the AKT signal by wortmannin did not exhibit such effects. Inhibition of the persistently activated ERK1/2 in Pb(II)-treated diploid human fibroblasts by PD98059 also markedly increased the mutagenicity and cytotoxicity. The Pb(II)-induced mutagenicity and cytotoxicity were significantly higher in nucleotide excision repair (NER)-deficient UVL-10 rodent cells than their counterpart AT3-2 cells; also, ERK1/2 activation by Pb(II) was observed in AT3-2 but not UVL-10 cells. Furthermore, cellular NER synthesis was enhanced by Pb(II) exposure, which was markedly suppressed by PD98059. Activation of ERK1/2 by expressing a constitutively active form of MKK1 in CL3 cells also elevated cellular NER synthesis. Together, these results indicate that persistent activation of ERK1/2 signaling by Pb(II) enhances cellular NER synthesis, thereby conferring anti-cytotoxicity and anti-mutagenicity.