Concurrent EGFR-TKI and Thoracic Radiotherapy as First-Line Treatment for Stage IV Non-Small Cell Lung Cancer Harboring EGFR Active Mutations.

LESSONS LEARNED: This single-arm, phase II study shows that concurrent EGFR-tyrosine kinase inhibitor plus thoracic radiotherapy as the first-line treatment for stage IV non-small cell lung cancer harboring EGFR active mutations provides long-term control for the primary lung lesion, and 1-year progression-free survival (PFS) rate and median PFS are numerically higher than those of the erlotinib monotherapy.Serious adverse events are acceptable, although grade >3 radiation pneumonitis occurred in 20% of patients. BACKGROUND: Studies show effective local control by EGFR-tyrosine kinase inhibitor (TKI) combined with radiotherapy at metastatic sites in advanced lung cancer harboring EGFR active mutations. Salvage local radiotherapy is associated with prolonged progression-free survival (PFS) in local disease during EGFR-TKI treatment. However, no prospective study has been reported on concurrent EGFR-TKI and radiotherapy for primary lung lesions. This study investigated the efficacy and safety of first-line EGFR-TKI combined with thoracic radiotherapy in treating stage IV non-small cell lung cancer (NSCLC) harboring EGFR active mutations. METHODS: We conducted a single-arm, phase II clinical trial. Each patient received EGFR-TKI (erlotinib 150 mg or gefitinib 250 mg per day) plus thoracic radiotherapy (54-60 Gy/27-30 F/5.5-6 w) within 2 weeks of beginning EGFR-TKI therapy until either disease progression or intolerable adverse events (AEs) appeared. RESULTS: From January 2015 to March 2018, 401 patients were screened, and 10 patients (5 male and 5 female) were eligible. These patients had a median age of 55 years (40-75) and median follow-up of 19.8 months (5.8-34). The 1-year PFS rate was 57.1%, median PFS was 13 months, and median time to progression of irradiated lesion (iTTP) was 20.5 months. Objective response rate (ORR), was 50% and disease control rate (DCR) was 100%. The most common grade ≥3 AEs were radiation pneumonitis (20%) and rash (10%). One patient died after rejecting treatment for pneumonitis. The others received a full, systematic course of glucocorticoid therapy. Pneumonitis was all well controlled and did not relapse. CONCLUSION: Concurrent EGFR-TKI plus thoracic radiotherapy as the first-line treatment for stage IV NSCLC harboring EGFR active mutations shows a long-term control of primary lung lesion. The 1-year PFS rate and median PFS of this combined therapy are numerically higher than those of the erlotinib monotherapy. The risk of serious adverse events is acceptable.

Plasma miRNAs in predicting radiosensitivity in non-small cell lung cancer.

BACKGROUND: Radioresistance of thoracic radiotherapy is a major bottleneck in the treatment of non-small cell lung cancer (NSCLC). Until now, there have been no effective biomarkers to predict the radiosensitivity. PURPOSES: Based on miRNA profile screened from NSCLC cell lines with different radiosensitivity, this study was conducted to explore the correlation between plasma miRNAs and radiotherapy response in NSCLC patients, and to identify biomarkers of the radiosensitivity in NSCLC. METHODS: Differentially expressed genes were acquired from time-series gene expression profiles of radioresistant H1299 and radiosensitive H460 lung cancer cells (GSE20549). Potential miRNAs were screened from these differentially expressed genes by combining bioinformatics with GO analysis, pathway analysis, and miRNA prediction. A clinical observational study was performed to explore the correlation between candidate miRNAs and radiotherapy response. Stage IIIa-IV NSCLC patients who received two to four cycles of previous chemotherapy and underwent thoracic radiotherapy alone were included. Total RNA was purified from peripheral blood before radiotherapy, and plasma miRNAs were detected by real-time PCR (qRT-PCR). Then, tumor response, progression-free survival (PFS), and overall survival (OS) were acquired. Four miRNAs significantly different between effective and ineffective groups were further analyzed to obtain cutpoints from receiver operating characteristic (ROC) curves and the predictive value of radiosensitivity. RESULTS: Candidate miRNAs included 14 miRNAs screened from radioresistant genes and five from radiosensitive genes. From Jan., 2013 to Dec., 2014, 54 eligible patients were enrolled with a median follow-up of 15.3 months (range 4.6 to 31.4) by the deadline of Aug. 31, 2015. Totally, there were no case of complete response (CR), 15 of partial response (PR), 35 of stable disease (SD), and 4 of progressive disease (PD). Eight patients had no progression and 19 patients were still alive. The median PFS and OS were 6.6 months (range 2.3 to 29.3) and 15.3 months (range 4.6 to 31.4), respectively. Four miRNAs (hsa-miR-98-5p, hsa-miR-302e, hsa-miR-495-3p, and hsa-miR-613) demonstrated a higher expression in effective group (CR + PR, 15 cases) than in ineffective group (SD + PD, 39 cases). Based on each cutpoint, objective response rate (ORR) was higher in miR-high group than in miR-low group. No miRNA showed correlation with median PFS or OS. CONCLUSION: Bioinformatical analysis and clinical verification reveal the correlation between plasma miRNAs and radiosensitivity in NSCLC patients. Plasma miRNAs represent novel biomarkers to predict radiotherapy response clinically.

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.

Interaction between the BDNF rs11030101 genotype and job stress on cognitive empathy.

BACKGROUND: Empathy refers to an individual's ability to experience the emotional and cognitive processes of another person during social interactions. Although many studies have examined the effects of genetic variation on emotional empathy, little is currently known about whether genetic factors may influence cognitive empathy. This study investigated the relationship between BDNF rs11030101 genotype, job stress, and empathy, especially cognitive empathy, in a Chinese Han population. METHODS: A cross-sectional design was used and 340 participants were recruited from a university in Beijing. Interpersonal Reactivity Index (IRI) was used to measure empathy. Job stress was measured using House and Rizzo's Job Stress Scale. The BDNF rs11030101 was genotyped in all participants. RESULTS: Gender and age were associated with various IRI subscales (p < 0.001). After controlling for gender, age and education level, BDNF rs11030101 genotype had no main effect on all empathy subscales (p > 0.05). Job stress was negatively associated with Perspective Taking (p = 0.006) and positively associated with Personal Distress (p < 0.001). In addition, the BDNF rs11030101 genotype modulated the relationship between job stress and Fantasy (p = 0.013), indicating that T allele carriers had higher Fantasy scores at higher job stress and lower Fantasy scores at lower job stress than AA homozygotes. This interaction was only present in women. LIMITATIONS: The sample size and single-nucleotide polymorphism are limited, and the cross-sectional design should be improved. CONCLUSIONS: Female university faculty with the BDNF rs11030101 T allele may utilize higher emotional job demands, thereby fostering their cognitive empathy.

IL-17 is associated with poor prognosis and promotes angiogenesis via stimulating VEGF production of cancer cells in colorectal carcinoma.

IL-17, which exerts strong pro-inflammatory effects, has emerged as an important mediator in inflammation-associated cancer. However, the characteristics of IL-17-producing cells, the relevance of IL-17 to clinical parameters and its function in the development and progression of colorectal carcinoma still remain to be explored. In the present study, we first found the levels of IL-17 producing cells were significantly increased in the tumor regions of samples from colorectal carcinoma patients compared with non-tumor regions. Confocal microscopic analysis showed co-staining of IL-17 with CD4 and CD68, indicating IL-17 in colorectal carcinoma was expressed by macrophage and Th17. High expression of IL-17 was associated with high microvessel density. Univariate and multivariate analysis revealed that IL-17 was an independent prognostic factor for overall survival. To explore the underlying mechanisms of IL-17 in angiogenesis, we used PCR-array to find pro-angiogenic factor in cancer cells specifically induced by IL-17, then validated VEGF as one of factors in IL-17-mediated angiogenesis with the use of quantitative RT-PCR, ELISA and VEGF immunohistochemistry. Our results propose IL-17 as a novel indicator of prognosis in the patients with colorectal carcinoma and could serve as a novel therapeutic target for colorectal carcinoma, furthermore our results indicate that IL-17 producing cells may facilitate development of colorectal carcinoma by fostering angiogenesis via promote VEGF production from cancer cells.

The Efficacy and Safety of Epidermal Growth Factor Receptor Tyrosine Kinase Inhibitor Combined With Thymosin in Advanced Non-Small Cell Lung Cancer Patients Harboring Active Epidermal Growth Factor Receptor Mutations.

OBJECTIVE: To explore the efficacy and safety of EGFR-TKI combined with thymosin therapy in advanced non-small cell lung cancer (NSCLC) patients harboring active EGFR mutations. METHODS: Patients confirmed as advanced NSCLC with active EGFR mutations were recruited from August 2008 to July 2018 retrospectively. Patients treated with EGFR-TKI were classified as the EGFR-TKI group. And those received EGFR-TKI and thymosin therapy were designated as the EGFR-TKI plus thymosin group. The primary endpoint was progression-free survival (PFS). The secondary endpoints included overall survival (OS), tumor response and adverse effects. RESULTS: The median PFS was significantly longer in EGFR-TKI plus thymosin group than that in EGFR-TKI group (14.4 months vs. 9.2 months; HR=0.433, 95% CI 0.322 - 0.582, P<0.0001). The median OS was also prolonged in EGFR-TKI plus thymosin group than that in EGFR-TKI group (29.5 months vs. 19.8 months; HR=0.430, 95% CI 0.319 - 0.580, P<0.0001). The objective response rate in EGFR-TKI plus thymosin group and EGFR-TKI group were 60.0% versus 60.8% (P=0.918). The disease control rate was 96.9% in EGFR-TKI plus thymosin group and 97.7% in EGFR-TKI group (P=1.000). There were no significant differences in adverse effects between the two groups. The number of CD3+T cells in peripheral blood decreased significantly after treatment including both CD3+CD4+T and CD3+CD8+T subsets in EGFR-TKI group, but not in EGFR-TKI plus thymosin group. CONCLUSIONS: Combination of EGFR-TKI and thymosin can significantly prolong the PFS and OS compared with EGFR-TKI monotherapy without more adverse events, which offers a new strategy in clinic.

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.

Clinical benefits of Livin peptide-loaded DCs/CIKs combined with chemotherapy in advanced non-small cell lung cancer.

Previous studies showed that Livin, a member of inhibitors of apoptosis protein (IAP), played an important role in drug and radiation resistance. When the expression of Livin was blocked, the sensitivity to both chemotherapy and radiotherapy was improved in lung cancer cells. A total of 79 patients diagnosed with non-small cell lung cancer (NSCLC) were enrolled into the current study from Jan 2012 to Apr 2016. The Livin and MUC-1 groups received one-cycle autologous DCs/CIKs infusion on days 11 to 14 additionally. The clinical efficacy, immune index, KPS score and adverse events were compared among the three groups. Median progression-free survival (mPFS) in Livin and MUC-1 groups was significantly longer than that in Chemo group (195 and 211 vs 138 days, P < 0.05), and the objective response rate (ORR) in Livin and MUC-1 groups was significantly higher than that in Chemo group (23.1% and 22.2% vs 5.1%, P < 0.05). The Tetramer value after treatment in Livin group was significantly higher than that before treatment (4.07 ± 3.77 vs 3.16 ± 3.82, P < 0.05). The concentration of Livin antibody in patients' peripheral blood before and after treatment in Livin group had no significant difference (P > 0.05). As for KPS score, scarce decrease was found in Livin and MUC-1 groups after chemotherapy treatment (0.77 ± 6.41 and 0.37 ± 5.18, respectively). However, obvious decrease of KPS score (P < 0.039) was recorded in Chemo group (3.85 ± 6.33). There was no significant difference in disease control rate (DCR), overall survival (OS), T cell subsets, cytokine levels (IFN-γ and IL-2) and adverse events between the three groups (P > 0.05). Livin peptide could be a novel substitute to trigger cell immunity by loading DCs in combination with chemotherapy in NSCLC.

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.

Novel treatment strategies for patients with HER2-positive breast cancer who do not benefit from current targeted therapy drugs.

Human epidermal growth factor receptor-2 positive breast cancer (HER2+ BC) is characterized by a high rate of metastasis and drug resistance. The advent of targeted therapy drugs greatly improves the prognosis of HER2+ BC patients. However, drug resistance or severe side effects have limited the application of targeted therapy drugs. To achieve more effective treatment, considerable research has concentrated on strategies to overcome drug resistance. Abemaciclib (CDK4/6 inhibitor), a new antibody-drug conjugate (ADC), src homology 2 (SH2) containing tyrosine phosphatase-1 (SHP-1) and fatty acid synthase (FASN) have been demonstrated to improve drug resistance. In addition, using an effective vector to accurately deliver drugs to tumors has shown good application prospects. Many studies have also found that natural anti-cancer substances produced effective results during in vitro and in vivo anti-HER2+ BC research. This review aimed to summarize the current status of potential clinical drugs that may benefit HER2+ BC patients in the future.

Administration of MIP-3alpha gene to the tumor following radiation therapy boosts anti-tumor immunity in a murine model of lung carcinoma.

Dendritic cells (DC), the most potent antigen presenting cells (APC), have been shown able to process apoptotic tumor cells and necrotic tumor cells for antigen presentation. Apoptosis and necrosis are the two common final pathways through which the tumors are killed by chemotherapy or radiation therapy. The tumor cells receiving radiation often produce the "danger signal" cytokines such as TNF-alpha and IL-1. Another cytokine MIP-3alpha that is able to attract DC to the tumor site is normally not secreted. We hypothesize that if artificial introduction of a large number of DC to the necrotic tumor site after radiation therapy by transfecting any cells at the tumor site to secrete DC-tropic MIP-3alpha, an anti-tumor immune response would be initiated. C57BL/6J mice bearing a well-known Lewis lung carcinoma are used to assess efficacy of this modality. The plasmid DNA containing pcDNA3.1/MIP-3alpha was injected into the subcutaneous tumors after radiation treatment. We demonstrate a detectable local expression of MIP-3alpha and local accumulation of DC. Tumor infiltrating lymphocytes after the treatment are predominantly CD8+ T-cells with rare CD4+ T-cells. The anti-tumor immune response was also measurable, which contributes at least in part to the finding that the treated mice have smaller tumor and prolonged survival, comparing to the control groups. This study suggests a potential new means of immune modulation and provides us a new concept of immunotherapy of cancer.

Feasibility study of DCs/CIKs combined with thoracic radiotherapy for patients with locally advanced or metastatic non-small-cell lung cancer.

BACKGROUND: The combination of dendritic cells (DCs) and cytokine-induced killer cells (CIKs) can induce the anti-tumor immune response and radiotherapy may promote the activity. We aimed to explore the feasibility of DCs/CIKs combined with thoracic radiotherapy (TRT) for patients with locally advanced or metastatic non-small-cell lung cancer (NSCLC). METHOD: In this study, patients with unresectable stage III/IV NSCLC and an Eastern Cooperative Oncology Group performance status (ECOG PS) of 0-2 and previously receiving two or more cycles of platinum-based doublet chemotherapy without disease progression received TRT plus DCs/CIKs or TRT alone until disease progression or unacceptable toxicity. The primary endpoint was median progression-free survival (mPFS). In treatment group, patients received four-cycle autologous DCs/CIKs infusion starting from the 6(th) fraction of irradiation. RESULTS: From Jan 13, 2012 to June 30, 2014, 82 patients were enrolled, with 21 patients in treatment group and 61 in control group. The mPFS in treatment group was longer than that in control group (330 days vs 233 days, hazard ratio 0.51, 95 % CI 0.27-1.0, P < 0.05), and the objective response rate (ORR) of treatment group (47.6 %) was significantly higher that of control group (24.6 %, P < 0.05). There was no significant difference in disease control rate (DCR) and median overall survival (mOS) between two groups (P > 0.05). The side effects in treatment group were mild and there was no treatment-related deaths. CONCLUSION: The combination of DCs/CIKs with TRT could be a feasible regimen in treating locally advanced or metastatic NSCLC patients. Further investigation of the regimen is warranted.

Clinical benefit from EGFR-TKI plus ginsenoside Rg3 in patients with advanced non-small cell lung cancer harboring EGFR active mutation.

PURPOSE: Acquired resistance is a bottleneck that restricts the efficacy of epidermal growth factor receptor-tyrosine kinase inhibitor (EGFR-TKI) for lung cancer. Ginsenoside Rg3 is an antiangiogenic agent which can down-regulate the expressions of vascular endothelial growth factor (VEGF) and EGFR. Combination of EGFR-TKI and ginsenoside Rg3 may be a promising strategy to delay acquired resistance. This retrospective study explored the efficacy and safety of this combined regimen in patients with EGFR mutation and advanced non-small cell lung cancer (NSCLC). RESULTS: By the deadline of March 31th 2016, the median follow-up period reached 22.9 months. The median PFS was significantly longer in group A than in group B (12.4 months vs 9.9 months, P = 0.017). In addition, ORR was significantly higher in group A than in group B (59.6% vs 41.7%, P = 0.049). The median OS in group A showed no extended tendency compared with that in group B (25.4 months vs 21.4 months, P = 0.258). No significant difference in side effects was found between the two groups. METHODS: A total of 124 patients with advanced NSCLC and EGFR active mutation were collected and analyzed. All of them were treated with first-line EGFR-TKI and divided into two groups. In group A (n=52), patients were administered EGFR-TKI plus ginsenoside Rg3 at standard doses. In group B (n=72), patients received EGFR-TKI alone. Progression-free survival (PFS), overall survival (OS), objective response rate (ORR) and side effects were analyzed. CONCLUSIONS: Ginsenoside Rg3 improves median PFS and ORR of first-line EGFR-TKI treatment in EGFR-mutant advanced NSCLC patients, thus providing a new regimen to delay acquired resistance of EGFR-TKI.

IGFBP7 functions as a potential lymphangiogenesis inducer in non-small cell lung carcinoma.

Lymphangiogenesis is not only involved in the processes of embryonic development, tissue repair and chronic inflammation, but also in tumor lymphatic metastasis. Metastatic tumor cells spreading through lymphatic vessels occur in non-small cell lung carcinoma (NSCLC), with regional lymph node metastasis often being the most important prognostic factor for carcinoma patients. Recent research has identified a range of lymphangiogenic growth factors that could conceivably play a great role in promoting tumor lymphangiogenesis and lymphatic metastasis. The most extensively accepted signaling pathways promoting lymphangiogenesis in tumors include the secreted lymphangiogenic proteins: vascular endothelial growth factor-C (VEGF-C) and VEGF-D, and their cognate receptor on lymphatic endothelium VEGF receptor-3 (VEGFR-3). Targeting VEGF pathway strategy sometimes failed to decrease tumor metastasis in vivo experiments and clinical trials. It is unclear whether the tumor cells induced the lymphangiogenesis process, while VEGF pathway could not completely illustrate the mechanism of tumor cell lymphatic metastasis. To explore the novel tumor lymphangiogenesis targets, we screened 181 candidate genes between high lymphatic vascular density (LVD) and low LVD in lung adenocarcinomas using Human Genome U133 Plus 2.0 Microarray. Insulin-like growth factor binding protein 7 (IGFBP7) was proven to be associated with metastatic clinicopathological features and high LVD. Furthermore, by assessing the capability of lymphatic endothelial cell forming lymphatic vessel-like structures in vitro, it appears to enhance lymphangiogenesis.

The co-transfection of p16(INK4a) and p14(ARF) genes into human lung cancer cell line A549 and the effects on cell growth and chemosensitivity.

Two functionally and structurally different proteins, p16(INK4a) and p14(ARF), encoded by the gene INK4a/ARF located at 9p21 are cyclin-dependent kinase (cdk) inhibitors and important cell cycle regulators. More and more evidences have been accumulated to show that the exogenous p16(INK4a) or p14(ARF) can inhibit the cell growth and/or induce the apoptosis. But it is still unclear if they can play positive role when combine with the conventional chemotherapy in cancer treatment. Here we show that cationic liposome-mediated gene transfection of INK4a/ARF into lung cancer cell line A549, in which the INK4a/ARF locus was lost, suppressed the growth and induced apoptosis. When treated with five different chemotherapy drugs with different mechanism after the transfection, A549 got an increased chemosensitivity for adriamycin and cisplatin and an unchanged result for topotecan, taxol or vinorelbine. The results indicated that cell cycle redistribution and increased apoptosis index after transfection might be the main explanation for the enhanced chemosensitivity. The combination of gene therapy with conventional chemotherapy is not always better than single chemotherapy. This trial will be of benefit to the treatment of lung cancer when combine the conventional chemotherapy and gene therapy in the future.

[Experimental study on lung carcinoma-targeted suicide gene therapy induced by irradiation].

OBJECTIVE: To improve the efficacy and selectivity of gene therapy for lung carcinoma, a strategy was designed for suicide gene therapy in conjunction with irradiation therapy, by constructing a plasmid tgEgr-HyTK in which HSV-TK gene was driven by the early growth responsive gene-1 (Egr-1) promoter. METHODS: The radio-inducible suicide gene was constructed by insertion of Egr-1 promoter upstream of the HSV-TK gene. The expressions of HSV-TK in lung carcinoma cell lines A549 which were infected with tgEgr-HyTK and exposed to different doses of gamma-ray irradiation were analyzed, and the relative survival rates of cells in presence of prodrug ganciclovir (GCV) were tested. The tumor suppression effects were investigated in 40 nude mice bearing lung tumors to examine the efficacy of this Egr-TK gene therapy in vivo. RESULTS: Expression of HSV-TK gene in lung carcinoma cells infected with tgEgr-HyTK plasmids was markedly increased in a radiation dose-dependent manner. A gene therapy experiment in vitro showed that tgEgr-HyTK transduced lung carcinoma cells became highly sensitive to GCV after irradiation, but not without irradiation. tgEgr-HyTK transfected tumors regressed significantly after a combination therapy of irradiation and GCV in all mice (n = 10), and five tumors disappeared in 3 weeks without any side effect. CONCLUSION: The data indicate that tumor targeted expression of HSV-TK gene under the control of a radio-inducible promoter represents a novel strategy for safe and effective gene therapy of lung carcinoma, which may have clinical application in the future.

[Oncostatin M gene therapy in mice bearing lung adenocarcinoma xenograft using a hypoxia/radiation dual-sensitive promoter].

OBJECTIVE: To improve the efficacy of radiogenetic therapy for lung cancer, a hypoxia/radiation dual-sensitive promoter was constructed to enhance the expression of oncostatin M (OSM) in transfected cells exposed to radiation under hypoxia. METHODS: The chimeric promoter HRE-Egr was generated by insertion of hypoxia response elements (HREs) upstream of the Early growth response gene-1 (Egr-1) promoter. OSM expression vector was constructed by cloning HRE-Egr promoter upstream of OSM gene, which was transfected into A549 cells. The expression of OSM in transfected cells exposed to irradiation and(or) hypoxia was analyzed, and the relative survival rate of transfected cells exposed to the above conditions was tested. To examine the efficacy of this HRE-Egr-OSM gene therapy in vivo, the tumor suppression effects were investigated in 40 nude mice bearing lung adenocarcinoma xenograft. RESULTS: Expression of OSM gene in transfected cells exposed 6 Gy irradiation was markedly increased under hypoxia. A gene therapy experiment in vitro showed that the survival rate of transfected cells exposed to radiation under hypoxia was obviously decreased with comparison of cells under normoxia. HRE-Egr promoter transfected tumors regressed significantly after a combination therapy of irradiation and HRE-Egr transfection in all mice (n = 10), and six tumors disappeared in 3 weeks without any side effects. CONCLUSION: The data indicate that tumor targeted expression of OSM gene under the control of a hypoxia/radiation dual-sensitive promoter represents a novel strategy for safe and effective gene therapy of lung carcinoma and might have clinical application in the future.

[Experimental study on lung cancer-targeted oncostatin M gene therapy induced by ionizing radiation].

BACKGROUND: To improve the efficacy and selectivity of gene therapy for lung cancer through inducing oncostatin M (OSM) gene expression by radiation via the early growth response gene-1 (Egr-1) promoter. METHODS: The radio-inducible OSM gene was constructed by insertion of Egr-1 promoter into upstream of the OSM gene. The expression of OSM in lung adenocarcinoma cell line A549 which was transfected with pEO and exposed to different doses of γ-ray irradiation was analyzed, and the relative survival fraction of cells and cell survival curve were observed. To examine the efficacy of this pEO gene therapy in vivo, the tumor supression effects were investigated in 40 nude mice bearing lung tumors. RESULTS: Expression of OSM gene in A549 cells transfected with pEO plasmids was markedly upregulated in a radiation dose-dependent manner. A gene therapy experiment in vitro showed that pEO transfected A549 cells became highly sensitive to ionizing radiation. pEO transfected tumors regressed significantly after a combination therapy with irradiation in all mice (n=10), and three tumors disappeared in 3 weeks without any side effect. CONCLUSIONS: The results indicate that tumor targeted expression of OSM gene under the control of a radio-inducible promoter represents a novel strategy for safe and effective gene therapy for lung cancer and might be widely applied in the future.