Case report: primary resistance to osimertinib in erlotinib-pretreated lung adenocarcinoma with EGFR T790 M mutation.

BACKGROUND: Among non-small cell lung cancer (NSCLC) patients with acquired T790 M mutation resistance to first-generation epidermal growth factor receptor-tyrosine kinase inhibitor (EGFR-TKI), 71% are likely to benefit from osimertinib. There have been several reports about the secondary resistance to osimertinib treatment in T790 M-positive patients, while primary resistance to osimertinib has been rarely reported. CASE PRESENTATION: A 62-year-old Asian male never smoker who presented with stage IV EGFR L858R-positive adenocarcinoma developed EGFR T790 M mutation after 14 months of treatment with erlotinib combined with thoracic radiotherapy as first-line therapy. The patient was initiated on osimertinib treatment with T790 M mutation detected (14.4%), but disease progressed 2 months later. CONCLUSION: The mechanism of primary resistance to osimertinib remains unclear. There may be an association between T790 M mutation disappearance, TP53 mutation and radiotherapy, but further researches are needed to confirm this.

MicroRNA profile of tumorigenic cells during carcinogenesis of lung adenocarcinoma.

To obtain microRNA (miRNA) profile and clarify their biological function in tumorigenic Sca-1(+) CD34(+) cells during carcinogenesis of lung adenocarcinoma. After intranasal infection with recombinant Adeno-Cre viruses (AdV-Cre), lung adenocarcinoma was identified pathologically in Lox-stop-lox Kras (LSL-Kras) G12D mice. Sca-1(+) CD34(+) cells were sorted by flow cytometry and tested for tumor-initiating ability, self-renewal and tumorigenicity. MiRNA profiles were obtained using microarray and further confirmed by real-time RT-PCR (qRT-PCR). MiRNA functions were predicted bioinformatically, and miR-294 function was verified to explore its role in tumor migration and invasion. Lung adenocarcinoma was induced in LSL-Kras G12D mice within 30 days. In vivo, the tumorigenicity of Sca-1(+) CD34(+) cells was 25 times stronger than Sca-1(-) CD34(-) cells. During tumorigenesis of lung adenocarcinoma, the expression of 145 miRNAs in Sca-1(+) CD34(+) cells increased and 72 miRNAs decreased (P < 0.01). Four successively up-regulated miRNAs (miR-15a*, miR-203, miR-294 and miR-295*) and three successively down-regulated ones (miR-19b, miR-483 and miR-615-5p) were identified. Among them, miR-294 could constitutively bind to 3'-UTR of matrix metalloproteinase 3 (MMP3), and down-regulate MMP3 protein expression. MiR-294 also significantly inhibited migration and invasion of Lewis lung cancer cells. MiRNAs are characteristically expressed in tumor-initiating Sca-1(+) CD34(+) cells of lung adenocarcinoma, and may play important roles during the carcinogenesis of lung adenocarcinoma.

Essential role of miR-200c in regulating self-renewal of breast cancer stem cells and their counterparts of mammary epithelium.

BACKGROUND: Breast cancer stem cells (BCSCs) have been reported as the origin of breast cancer and the radical cause of drug resistance, relapse and metastasis in breast cancer. BCSCs could be derived from mutated mammary epithelial stem cells (MaSCs). Therefore, comparing the molecular differences between BCSCs and MaSCs may clarify the mechanism underlying breast carcinogenesis and the targets for gene therapy. Specifically, the distinct miRNome data of BCSCs and MaSCs need to be analyzed to find out the key miRNAs and reveal their roles in regulating the stemness of BCSCs. METHODS: MUC1(-)ESA(+) cells were isolated from normal mammary epithelial cell line MCF-10A by fluorescence-activated cell sorting (FACS) and tested for stemness by clonogenic assay and multi-potential differentiation experiments. The miRNA profiles of MaSCs, BCSCs and breast cancer MCF-7 cells were compared to obtain the candidate miRNAs that may regulate breast tumorigenesis. An miRNA consecutively upregulated from MaSCs to BCSCs to MCF-7 cells, miR-200c, was chosen to determine its role in regulating the stemness of BCSCs and MaSCs in vitro and in vivo. Based on bioinformatics, the targets of miR-200c were validated by dual-luciferase report system, western blot and rescue experiments. RESULTS: In a 2-D clonogenic assay, MUC1(-)ESA(+) cells gave rise to multiple morphological colonies, including luminal colonies, myoepithelial colonies and mixed colonies. The clonogenic potential of MUC1(-)ESA(+) (61.5 ± 3.87 %) was significantly higher than that of non-stem MCF-10A cells (53.5 ± 3.42 %) (P < 0.05). In a 3-D matrigel culture, MUC1(-)ESA(+) cells grew into mammospheres with duct-like structures. A total of 12 miRNAs of interest were identified, 8 of which were upregulated and 4 downregulated in BCSCs compared with MaSCs. In gain- and lost-of-function assays, miR-200c was sufficient to inhibit the self-renewal of BCSCs and MaSCs in vitro and the growth of BCSCs in vivo. Furthermore, miR-200c negatively regulated programmed cell death 10 (PDCD10) in BCSCs and MaSCs. PDCD10 could rescue the tumorigenesis inhibited by miR-200c in BCSCs. DISCUSSION: Accumulating evidence shows that there is a milignant transformation from MaSCs into BCSCs. The underlying mechanism remains unclear. In present study, miRNA profiles between MaSCs and BCSCs were obtained. Then miRNA-200c, downregulated in both MaSCs and BCSCs, were verified as anti-oncogene, and played essential role in regulating self-renewal of both kinds of stem-like cells. These findings reveal a novel insights of breast tumorigenesis. CONCLUSIONS: PDCD10 is a target gene of miR-200c and also a possible mechanism by which miR-200c plays a role in regulating the stemness of BCSCs and MaSCs.

Chitosan combined with molecular beacon for mir-155 detection and imaging in lung cancer.

Lung cancer is the major cause of cancer-related deaths worldwide, thus developing effective methods for its early diagnosis is urgently needed. In recent years, microRNAs (miRNAs, miR) have been reported to play important roles in carcinogenesis and have become potential biomarkers for cancer diagnosis and treatment. Molecular beacon (MB) technology is a universal technology to detect DNA/RNA expression in living cells. As a natural polymers, chitosan (CS) nanoparticles could be used as a carrier for safe delivery of nucleic acid. In this study, we developed a probe using nanoparticles of miR-155 MB self assembled with CS (CS-miR-155 MB) to image the expression of miR-155 in cancer cells. Hybridization assay showed that the locked nucleic acid (LAN) modified miR-155 MB could target miR-155 effectively and sensitively. The miR-155 MB self-assembly with CS nanoparticles formed stable complexes at the proper weight ratio. The CS nanoparticles showed higher fluorescence intensity and transfection efficiency than the lipid-based formulation transfection agent by confocal microscopy and flow cytometry analysis. The CS-MB complexes were found to be easily synthesized and exhibited strong enzymatic stability, efficient cellular uptake, high target selectivity and biocompatibility. The CS-MB complexes can also be applied in other cancers just by simply changing for a targeted miRNA highly expressed in those cancer cells. Therefore, it is a promising vehicle used for detecting miRNA expression in living cells.

CCND1 G870A polymorphism interaction with cigarette smoking increases lung cancer risk: meta-analyses based on 5008 cases and 5214 controls.

Evidence indicates CCND1 G870A polymorphisms as a risk factor for a number of cancers. Increasing studies have been conducted on the association of CCND1 G870A polymorphism with lung cancer risk. However, the results were controversial. The aim of the present study was to derive a more precise estimation of the relationship. Meta-analyses examining the association between CCND1 G870A polymorphism and lung cancer were performed. Subgroup analyses regarding ethnicity, smoking status, histological types and source of controls were also implemented. All eligible studies for the period up to May 2012 were identified. The overall data from ten case-control studies including 5,008 cases and 5,214 controls indicated that variant A allele may have an association with increased lung cancer risk (AA vs GG: OR = 1.21; 95 % CI = 1.08-1.36, dominant model: OR = 1.09; 95 % CI = 1.00-1.19, recessive model: OR = 1.23; 95 % CI = 1.01-1.49). In the subgroup analysis by ethnicity, A allele may elevate lung cancer risk among Asians but not Caucasians or Mixed ethnicities. In smoking status subgroup, A allele was shown to associate with increased lung cancer risk among smokers but not non-smokers. In the subgroup analysis by histological types, increased cancer risks were shown in adenocarcinoma but not squamous cell carcinoma, under the homozygote comparison and recessive models. Collectively, the results of the present study suggest that CCND1 G870A polymorphism might be a low-penetrant risk factor for lung cancer, particularly among Asians and smokers. Moreover, homozygous AA alleles might have a correlation with increased lung adenocarcinoma susceptibility.

Novel molecular beacons to monitor microRNAs in non-small-cell lung cancer.

Lung cancer is the leading cause of cancer death worldwide. There is no effective early diagnostic technology for lung cancer. microRNAs (miRNAs) are noncoding RNA molecules which regulate the process of cell growth and differentiation in human cancers. Hsa-miR-155 (miR-155), highly expressed in non-small-cell lung cancer (NSCLC), can be used as a diagnostic marker for NSCLC. Dynamic observation of miR-155 is critical to diagnose NSCLC. A novel molecular beacon (MB) of miR-155 was designed to image the expression of miR-155 in NSCLC. Then miR-155 was detected in vitro by laser confocal microscopy and in vivo by stereomicroscope imaging system, respectively. The present study demonstrated that intracellular miR-155 could be successfully and quickly detected by novel miR-155 MBs. As a noninvasive monitoring approach, MBs could be used to diagnose lung cancer at early stage through molecular imaging.

MTHFR C677T and A1298C polymorphisms and cervical carcinoma susceptibility: meta-analyses based on 4,421 individuals.

MTHFR polymorphisms have been implicated as risk factors for several cancers. Studies have conducted on the associations of MTHFR polymorphisms with cervical carcinoma risk and have generated inconclusive results. The aim of the present study was to increase power demonstrating the possible relations. Meta-analyses examining the association between MTHFR C677T and A1298C polymorphisms and cervical carcinoma risk were performed. Separate analyses on ethnicity and source of controls were also implemented. Eligible studies were identified for the period up to Dec 2011. Eleven case-control studies containing 1859 cases and 2562 controls regarding MTHFR C677T polymorphisms were selected, of which four studies containing 461 cases and 832 controls described A1298C polymorphisms. For the overall data, no associations of MTHFR C677T polymorphisms with cervical carcinoma were observed (TT vs CC: OR = 1.07; 95 %CI = 0.73-1.58; dominant model: OR = 0.89; 95 %CI = 0.66-1.18; recessive model: OR = 1.13; 95 %CI = 0.84-1.52). In the subgroup analysis by ethnicity, MTHFR 677T allele was associated with decreased cervical cancer susceptibility among Caucasians (TT vs CC: OR = 0.65; 95 %CI = 0.45-0.93; dominant model: OR = 0.70; 95 %CI = 0.58-0.86) but not Asians. As for A1298C polymorphism, no marked associations of A1298C genetic variation with cervical cancer risk were observed (CC vs AA: OR = 1.01; 95 %CI = 0.60-1.73; dominant model: OR = 1.17; 95 %CI = 0.91-1.49; recessive model: OR = 0.99; 95 %CI = 0.60-1.63). Collectively, the results of the present study suggest that MTHFR 677T allele might play a preventive role for cervical carcinoma among Caucasians. A1298C polymorphisms might exert little effect on cervical cancerigenesis.

CXCR4 positive cells from Lewis lung carcinoma cell line have cancer metastatic stem cell characteristics.

There is increasing evidence that cancer stem cells contribute to the initiation and propagation of many tumor. Therefore, to find out and identify the metastatic tumor stem-like cells in Lewis lung cancer cell line (LLC), the expression of CXCR4 was measured in LLC by flow cytometry and observed by laser scanning confocal microscope (LSCM). After the CXCR4(+) LLC cell was isolated from LLC by magnetic cell sorting, its properties were evaluated by their tumorigenic and metastatic potentials. CXCR4(+) cells were counted for 0.18% of the total number of LLC, and immunofluorescent staining cells were identified by LSCM. CXCR4(+) LLC suspension cultured in a serum-free medium, cell spheres expressed a high level of Sca-1. The chemotherapy sensitivity to cisplatin of CXCR4(+) LLC was lower than that of CXCR4(-) LLC. The expression of ABCG2 and IGF1R mRNA in CXCR4(+) LLC was higher than that in CXCR4(-) LLC (P < 0.01). Most of CXCR4(+) LLC cells were close to vascular endothelial cells, aberrant vasculature around it was forming. The expression of VEGF and MMP9 mRNA in CXCR4(+) LLC was higher than that in CXCR4(-) LLC (P < 0.05), the microvessel density (MVD) of CXCR4(+) subsets growing were higher than that of CXCR4(-) subsets growing tumor tissue (P < 0.01). The tumor size, volume, and metastatic foci in the lungs of CXCR4(+) LLC was significantly higher than that in CXCR4(-) LLC (P < 0.001). Similarly, elevated expression of MMP9 and VEGF was also positively associated with CXCR4(+) LLC. Our results demonstrated that CXCR4(+) cells from Lewis lung carcinoma cell line exhibit cancer metastatic stem cell characteristics.

The effects of artesunate on the expression of EGFR and ABCG2 in A549 human lung cancer cells and a xenograft model.

Non-small cell lung cancer (NSCLC) is the leading cause of cancer death worldwide. Clinical and laboratory studies have suggested that multi-targeting approaches against neoplastic cells could help to increase patient survival and might reduce the emergence of cells that are resistant to single-target inhibitors. Artesunate (ART) is one of the most potent and rapidly acting antimalarial agents known, and it also exerts a profound cytotoxic activity toward cancer cells and reverses multi-drug resistance. In the present study, we found that artesunate inhibited NSCLC A549 cell growth and proliferation, induced apoptosis and suppressed tumor growth in a dose-dependent manner in A549 cells and a mouse xenograft model. Furthermore, artesunate down-regulated the expression of epidermal growth factor receptor (EGFR), Akt and ATP-binding cassette subfamily G member 2 (ABCG2) at the mRNA and protein levels in vitro and in vivo. In conclusion, artesunate is an effective anti-cancer drug that may enhance the effectiveness of other anticancer drugs and may reverse multi-drug resistance by suppressing the transcription of ABCG2, which inhibits drug efflux.

[The changes in secretory function of pulmonary intravascular macrophages after challenge of lipopolysaccharide].

OBJECTIVE: To investigate the role of pulmonary intravascular macrophages (PIMs) in the pathogenesis of acute lung injury (ALI) due to infection. METHODS: Porcine pulmonary blood vessels were flushed by modified Morton method, and PIMs were isolated and cultured. The adhered PIMs were collected with adhesion method and incubated in RPMI 1640 medium. They were challenged with lipopolysaccharide (LPS, 10 mg/L). The activity of interleukin-1ß (IL-1ß), and contents of IL 6 and IL 8 in the culture supernatant were measured by method of thymocyte proliferation and enzyme linked immunoadsorbent assay (ELISA). RESULTS: The released contents of IL-1ß, IL-6 and IL-8 from PIMs were increased significantly compared with those before LPS challenge , and they peaked at 2 hours [IL-1ß activity: (10 400 ± 2 389) scintillant count/min], 4 hours [IL-6 content: (0.80 ± 0.36) µg/L], and 6 hours [IL-8 content: (4.94 ± 1.19) µg/L ] after LPS challenge , and the differences were significant compared with hose before LPS challenge [IL-1ß activity: (213 ± 85) scintillant count/min, IL-6 content: (0.27 ± 0.12) µg/L, IL-8 content: (1.84 ± 0.53) µg/L, all P <0.01]. CONCLUSION: Among the cytokines released from PIMs after LPS challenge , the increase in IL-1ß occurred earlier in comparison with that of IL-6 and IL-8, suggesting that the former might play an important role at the early stage of ALI; on the other hand, though the increase in IL-6 and IL-8 contents occurred later than that of IL- 1ß but it lasted for a longer duration, suggesting that they might be associated with the advancement of ALI. The Results also suggested that interaction of these cytokines played a more important role in the pathogenesis of ALI.

Detection of miR-155-5p and imaging lung cancer for early diagnosis: in vitro and in vivo study.

PURPOSE: Currently, the routine screening program has insufficient capacity for the early diagnosis of lung cancer. Therefore, a type of chitosan-molecular beacon (CS-MB) probe was developed to recognize the miR-155-5p and image the lung cancer cells for the early diagnosis. METHODS: Based on the molecular beacon (MB) technology and nanotechnology, the CS-MB probe was synthesized self-assembly. There are four types of cells-three kinds of animal models and one type of histopathological sections of human lung cancer were utilized as models, including A549, SPC-A1, H446 lung cancer cells, tumor-initiating cells (TICs), subcutaneous and lung xenografts mice, and lox-stop-lox(LSL) K-ras G12D transgenic mice. The transgenic mice dynamically displayed the process from normal lung tissues to atypical hyperplasia, adenoma, carcinoma in situ, and adenocarcinoma. The different miR-155-5p expression levels in these cells and models were measured by quantitative real-time polymerase chain reaction (qRT-PCR). The CS-MB probe was used to recognize the miR-155-5p and image the lung cancer cells by confocal microscopy in vitro and by living imaging system in vivo. RESULTS: The CS-MB probe could be used to recognize the miR-155-5p and image the lung cancer cells significantly in these cells and models. The fluorescence intensity trends detected by the CS-MB probe were similar to the expression levels trends of miR-155 tested by qRT-PCR. Moreover, the fluorescence intensity showed an increasing trend with the tumor progression in the transgenic mice model, and the occurrence and development of lung cancer were dynamically monitored by the differen fluorescence intensity. In addition, the miR-155-5p in human lung cancer tissues could be detected by the miR-155-5p MB. CONCLUSION: Both in vivo and in vitro experiments demonstrated that the CS-MB probe could be utilized to recognize the miR-155-5p and image the lung cancer cells. It provided a novel experimental and theoretical basis for the early diagnosis of the disease. Also, the histopathological sections of human lung cancer research laid the foundation for subsequent preclinical studies. In addition, different MBs could be designed to detect other miRNAs for the early diagnosis of other tumors.

Preliminary validation of ERBB2 expression regulated by miR-548d-3p and miR-559.

ERBB2 overexpression occurs in numerous types of primary human tumors and alterations in microRNA (miRNA) expression have been associated with tumor suppression or tumorigenesis in human cancer, nevertheless, little is known about natural miRNAs acting on ERBB2. In this study, bioinformatical analysis of the 3'-UTRs of ERBB2 revealed the target elements for miR-548d-3p and miR-559. Moreover, a predicted miRNA/mRNA interaction experimental validation showed that both miR-548d-3p and miR-559 can interact specifically with the 3'-UTR of the ERBB2 mRNA. And miR-548d-3p plus miR-559 transfection showed a cooperative regulation of translationally repressing ERBB2 mRNA rather than by either miR-548d-3p or miR-559 alone. These results not only support the idea that different miRNAs can simultaneously and cooperatively repress a given target mRNA but also preliminarily validate the role of miR-548d-3p and miR-559 in regulating the ERBB2 expression. These data provide molecular basis for the application of miRNAs in ERBB2-targeted therapy.

Neutralization of complement regulatory proteins CD55 and CD59 augments therapeutic effect of herceptin against lung carcinoma cells.

Human monoclonal anti-Her2/neu antibody (herceptin, also named trastuzumab) failed in the treatment of lung cancer when in combination with two chemotherapy agents gemcitabine and cisplatin, despite of its clinical benefit in women with Her2 positive breast cancer. The capacity of herceptin to activate human complement and complement-dependent cytotoxicity against tumor cells was investigated in a study of tumor immunotherapy. We found that the expression of membrane complement regulatory proteins (mCRPs), CD55 and CD59 on non-small cell lung cancer (NSCLC) cells was closely correlated with histological types, prognosis and preoperational adjutant chemotherapy of the disease. Herceptin-mediated complement cytotoxicity to two human lung carcinoma cell lines exerted stronger killing effect on tumor cells after the neutralization of mCPRs via their antibodies. Furthermore, treatment of herceptin combined with chemo-agents had advantages over chemotherapy alone, while CD55 and CD59 expression levels both declined remarkably in A549 and H157 cell lines after incubation with IC50 cisplatin for 72 h. Our data indicated that overexpression of mCRPs on tumor cells contributes to herceptin's acquisition of resistance to NSCLC, and its anticancer efficacy was enhanced when mCRPs were neutralized or cisplatin could be used to down-regulate their expression.

Short interfering RNA directed against TWIST, a novel zinc finger transcription factor, increases A549 cell sensitivity to cisplatin via MAPK/mitochondrial pathway.

Previous reports have implicated epithelial-mesenchymal transition (EMT) as a major cause of cancer. TWIST, a novel zinc finger transcription factor, was suggested to be an important inducer of EMT and therefore be involved in different phases of tumorigenicity. However, whether TWIST suppression could increase chemosensitivity of cancer cells to chemotherapeutic agent remains unclear. In the present study, we utilized RNA interference to knockdown TWIST expression in A549 cells and further assessed the cell viability and apoptosis as well as possible MAPKs and mitochondrial pathways. The data showed that TWIST depletion significantly sensitized A549 cells to cisplatin by inducing activation of JNK/mitochondrial pathway but not ERK and p-38 pathways, suggesting critical roles of TWIST in A549 cell chemoresistance to cisplatin and raising the possibility of TWIST depletion as a promising approach to lung cancer therapy.

MicroRNA expression profile of bronchioalveolar stem cells from mouse lung.

Increasing evidence has suggested that bronchioalveolar stem cell (BASC) is the progenitor cells of lung cancer stem cells. However, the mechanisms by which self-renewal of BSACs is controlled and how BASCs turn into cancer stem cells still remains to be unknown. In the present study, we successfully isolated bronchioalveolar stem cells (BASCs) from mouse lung using FACS. These BASCs were characterized by clonal growth, self-renewal and high capacity for differentiation, suggesting that these BASCs are indeed stem cells. We investigated the microRNA (miRNA) expression profile of these BASCs using miRNA array and quantitative RT-PCR. We discovered that BASCs possessed a unique miRNA profile, with altered expression of several microRNAs, such as miR-142-3p, miR-451, miR-106a, miR-142-5p, miR-15b, miR-20a, miR-106b, miR-25, miR-486, in BASCs compared to control cells. Our results suggest that microRNAs might play important roles in maintaining the self-renewal capacity of BASCs, and suggest the intriguing possibility that aberrant expression of microRNAs could involved in turning BASCs into lung cancer stem cells.

A dosimetric phantom study of thoracic radiotherapy based on three-dimensional modeling of mediastinal lymph nodes.

The aim of the present study was to investigate the optimal strategy and dosimetric measurement of thoracic radiotherapy based on three-dimensional (3D) modeling of mediastinal lymph nodes (MLNs). A 3D model of MLNs was constructed from a Chinese Visible Human female dataset. Image registration and fusion between reconstructed MLNs and original chest computed tomography (CT) images was conducted in the Eclipse™ treatment planning system (TPS). There were three plans, including 3D conformal radiotherapy (3D-CRT), intensity-modulated radiotherapy (IMRT) and volumetric-modulated arc therapy (VMAT), which were designed based on 10 cases of simulated lung lesions (SLLs) and MLNs. The quality of these plans was evaluated via examining indexes, including conformity index (CI), homogeneity index and clinical target volume (CTV) coverage. Dose-volume histogram analysis was performed on SLL, MLNs and organs at risk (OARs). A Chengdu Dosimetric Phantom (CDP) was then drilled at specific MLNs according to 20 patients with thoracic tumors and of a medium-build. These plans were repeated on fused MLNs and CDP CT images in the Eclipse™ TPS. Radiation doses at the SLLs and MLNs of the CDP were measured and compared with calculated doses. The established 3D MLN model demonstrated the spatial location of MLNs and adjacent structures. Precise image registration and fusion were conducted between reconstructed MLNs and the original chest CT or CDP CT images. IMRT demonstrated greater values in CI, CTV coverage and OAR (lungs and spinal cord) protection, compared with 3D-CRT and VMAT (P<0.05). The deviation between the measured and calculated doses was within ± 10% at SLL, and at the 2R and 7th MLN stations. In conclusion, the 3D MLN model can benefit plan optimization and dosimetric measurement of thoracic radiotherapy, and when combined with CDP, it may provide a tool for clinical dosimetric monitoring.

Identification and imaging of miR-155 in the early screening of lung cancer by targeted delivery of octreotide-conjugated chitosan-molecular beacon nanoparticles.

Lung cancer is still the most common cancer globally. Early screening remains the key to improve the prognosis of patients. There is currently a lack of specific and sensitive methods for early screening of lung cancer. In recent years, studies have found that microRNA plays an important role in the occurrence and development of lung cancer and become a biological target in the early diagnosis of lung cancer. In this study, lung cancer cells, subcutaneous xenografts of lung cancer in nude mice, and Lox-Stop-lox K-ras G12D transgenic mice were used as models. The transgenic mice displayed the dynamic processes from normal lung tissue to atypical hyperplasia, adenomas, carcinoma in situ and lung adenocarcinoma. It was found that miR-155 and somatostatin receptor 2 (SSTR2) were expressed in all the disease stages of transgenic mice. Through molecular beacon (MB) technology and nanotechnology, chitosan-molecular beacon (CS-MB) nanoparticles and targeted octreotide (OCT) were conjugated and synthesized. The octreotide-conjugated chitosan-molecular beacon nanoparticles (CS-MB-OCT) can specifically bind to SSTR2 expressed by the lung cancer cells to achieve the goal of identification of lung cancer cells and imaging miR-155 in vivo and in vitro. Fluorescence imaging at different disease stages of lung cancer in Lox-Stop-lox K-ras G12D transgenic mice was performed, and could dynamically monitor the occurrence and development of lung cancer by different fluorescence intensity ranges. The current research, in turn, provides new idea, new method, and new technology for the early screening of lung cancer.

Induction of apoptosis and inhibition of cell migration and tube-like formation by dihydroartemisinin in murine lymphatic endothelial cells.

Dihydroartemisinin (DHA) is a semisynthesized agent from the artemisinin first extracted from the Chinese plant Artemisia annua. Previous studies have shown that artemisinin derivates, apart from their antimalarial activity, possess antitumor, antiangiogenic, and anti-inflammatory effects. In the present investigation, DHA was found to have a potent ability in influencing lymphatic endothelial cells (LECs) behavior. Murine LECs were isolated from benign lymphangiomas induced by intraperitoneal injection of incomplete Freund's adjuvant and identified by indirect immunofluorescence assay and fluorescence-activated cell sorting analysis to examine the expression of the specific marker VEGFR-3/Flt-4. When LECs were treated with DHA at 10 microg/ml, the growth of LECs was inhibited, and LECs showed typical apoptotic morphological features, with a higher apoptotic rate as compared with the controls. DHA also exerted a significant inhibitory effect on migration and tube-like formation of LECs in a dose-dependent manner. Quantitative RT-PCR further showed that DHA remarkably downregulated the expression of antiapoptotic bcl-2 mRNA, but upregulated that of the proapoptotic gene bax mRNA. In addition, DHA could strongly attenuate the mRNA and protein levels of VEGFR-3/Flt-4. In summary, these findings indicate that DHA may be useful as a potential lymphangiogenesis inhibitor under induction of cell apoptosis, inhibition of the migration, and formation of tube-like structures in LECs.

Correlation between DNA repair capacity in lymphocytes and acute side effects to skin during radiotherapy in nasopharyngeal cancer patients.

PURPOSE: Repair of radiation-induced DNA damage plays a critical role for both the susceptibility of patients to side effects after radiotherapy and their subsequent cancer risk. The study objective was to evaluate whether DNA repair data determined in vitro are correlated with the occurrence of acute side effects during radiotherapy. EXPERIMENTAL DESIGN: Nasopharyngeal cancer patients receiving radiation therapy were recruited in a prospective epidemiologic study. As an indicator for clinical radiosensitivity, adverse reactions of the skin were recorded. Cryopreserved lymphocytes from 100 study participants were gamma-irradiated with 5 Gy in vitro and analyzed using the alkaline comet assay. Reproducibility of the assay was determined by repeated analysis (n = 22) of cells from a healthy donor. A coefficient of variation of 0.24 was calculated. RESULTS: The various parameters determined to characterize the individual DNA repair capacity showed large differences between patients. Twenty-one patients were identified with considerably enhanced DNA damage induction, and 19 patients exhibited severely reduced DNA repair capacity after 15 and 30 minutes. Eight patients were considered as clinically radiosensitive, indicated by moist desquamation of the skin after a total radiation dose of 70 Gy. CONCLUSIONS: Using the alkaline comet assay as described here, nasopharyngeal cancer patients were identified showing abnormal cellular radiation effects, but this repair deficiency corresponded only at a very limited extent to the acute radiation sensitivity of the skin.

[Clinical and prognostic significance of podoplanin-positive lymphatic vessel density in non-small cell lung carcinoma].

OBJECTIVE: The aim of this study was to investigate the clinical and prognostic significance of lymphangiogenesis in non-small cell lung carcinoma (NSCLC). METHODS: The expression of lymphatic vessel endothelium markers podoplanin, VEGFR-3 and vascular endothelium marker CD31 was detected in paraffin sections from 68 cases of NSCLC and 8 cases of pulmonary inflammatory myofibroblastic tumor (PIMT) by immunohistochemistry (SP). Microvessel density (MVD) and lymphatic vessel density (LVD) were counted. Specificity of lymphatic vessel endothelium markers was compared between VEGFR-3 and podoplanin. Lymphangiogenesis, quantified by evaluating LVD, was correlated with various clinical pathological parameters and prognostic relevance. RESULTS: No significant association was found between the number of podoplanin positive vessels and the number of CD31 positive or VEGFR-3 positive vessels (r = -0.171, P = 0.124; r = 0.003, P = 0.979), but the counts of VEGFR-3 positive vessels were associated with CD31 positive vessel counts (r = 0.331, P = 0.002). LVD in PIMT group was significantly lower than that in NSCLC group (P = 0.004). Compared with that without the lymph node metastasis group, LVD in the positive group increased significantly (P = 0.033); LVD in pathological stage III and IV was higher than that in pathological stage I and II (P = 0.001). There was no difference of LVD in different cell differentiation, age and sex groups. The 5-year survival rate for high LVD was significantly lower than that of low LVD. Multivariate analysis showed that LVD was a significant and independent prognostic factor. CONCLUSIONS: Lymphangiogenesis may be a significant prognostic factor for NSCLC.