Strategies for prolonged therapy in patients with advanced non-small-cell lung cancer

Glutaredoxin 2 Protein (Grx2) as an Independent Prognostic Factor Associated with the Survival of Colon Adenocarcinoma Patients

Glutaredoxin 2 (Grx2; Glrx2) is a glutathione-dependent oxidoreductase located in mitochondria, which is central to the regulation of glutathione homeostasis and mitochondrial redox, and plays a crucial role in highly metabolic tissues. In response to mitochondrial redox signals and oxidative stress, Grx2 can catalyze the oxidation and S-glutathionylation of membrane-bound thiol proteins in mitochondria. Therefore, it can have a significant impact on cancer development. To investigate this further, we performed an immunohistochemical analysis of Grx2 protein expression in colon adenocarcinoma samples collected from patients with primary colon adenocarcinoma (stage I and II) and patients with metastasis to regional lymph nodes (stage III). The results of our study revealed a significant relationship between the immunohistochemical expression of Grx2 and tumor histological grade, depth of invasion, regional lymph node involvement, angioinvasion, staging, and PCNA immunohistochemical expression. It was found that 87% of patients with stage I had high levels of Grx2 expression. In contrast, only 33% of patients with stage II and 1% of patients with stage III had high levels of Grx2 expression. Moreover, the multivariate analysis revealed that the immunohistochemical expression of Grx2 protein apart from the grade of tumor differentiation was an independent prognostic factors for the survival of patients with colon adenocarcinoma. Studies analyzing Grx2 levels in patients' blood confirmed that the highest levels of serum Grx2 protein was also found in stage I patients, which was reflected in the survival curves. A higher level of Grx2 in the serum has been associated with a more favorable outcome. These results were supported by in vitro analysis conducted on colorectal cancer cell lines that corresponded to stages I, II, and III of colorectal cancer, using qRT-PCR and Western Blot.

A mouse model for the study of anti-tumor T cell responses in Kras-driven lung adenocarcinoma

Kras-driven lung adenocarcinoma (LUAD) is the most common lung cancer. A significant fraction of patients with Kras-driven LUAD respond to immunotherapy, but mechanistic studies of immune responses against LUAD have been limited because of a lack of immunotherapy-responsive models. We report the development of the immunogenic KP × NINJA (inversion inducible joined neoantigen) (KP-NINJA) LUAD model. This model allows temporal uncoupling of antigen and tumor induction, which allows one to wait until after infection-induced inflammation has subsided to induce neoantigen expression by tumors. Neoantigen expression is restricted to EPCAM+ cells in the lung and expression of neoantigen was more consistent between tumors than when neoantigens were encoded on lentiviruses. Moreover, tumors were infiltrated by tumor-specific CD8 T cells. Finally, LUAD cell lines derived from KP-NINJA mice were immunogenic and responded to immune checkpoint therapy (anti-PD1 and anti-CTLA4), providing means for future studies into the immunobiology of therapeutic responses in LUAD.

Conditioned medium of primary lung cancer cells induces EMT in A549 lung cancer cell line by TGF-ß1 and miRNA21 cooperation

The epithelial-mesenchymal transition (EMT) plays a key role in tumor progression, drug resistance and metastasis. Recently, numerous microRNA (miRNA) have been described to regulate EMT in tumor progression. In this study, we found that conditioned medium from the LC212 non-small-cell lung cancer (NSCLC) cell line (LC212-CM) induces morphological changes and overexpression of Vimentin, CD90, SMAD 2/3, SLUG and TWIST in A549 NSCLC cells, consistent with a mesenchymal phenotype. To identify the soluble mediators in LC212-CM involved in this phenomenon, we performed miRNA profiling and TGF-β1 quantification. We found that LC212-CM contains high levels of TGF-β1 as well as different secreted miRNAs. We focused our attention on Homo sapiens-microRNA21 (hsa-miR21), one of most relevant miRNA associated with lung cancer progression, metastasis and EMT. An hsa-miR21 antagomiR was able to prevent the LC212-CM-induced EMT phenotype in A549 cells. Furthermore, we found that TGF-β1 and hsa-miR21 cooperate in the induction of EMT in A549 cells. Intriguingly, TGF-β1 was found to induce hsa-miR21 expression in A549 cell, thus suggesting that the hsa-miR21 mediates at least in part the pro-EMT effects of TGF-β1. In conclusion, hsa-miR21 and TGF-β1 are involved in autocrine and paracrine circuits that regulate the EMT status of lung cancer cells.

ROS and the DNA damage response in cancer

Reactive oxygen species (ROS) are a group of short-lived, highly reactive, oxygen-containing molecules that can induce DNA damage and affect the DNA damage response (DDR). There is unequivocal pre-clinical and clinical evidence that ROS influence the genotoxic stress caused by chemotherapeutics agents and ionizing radiation. Recent studies have provided mechanistic insight into how ROS can also influence the cellular response to DNA damage caused by genotoxic therapy, especially in the context of Double Strand Breaks (DSBs). This has led to the clinical evaluation of agents modulating ROS in combination with genotoxic therapy for cancer, with mixed success so far. These studies point to context dependent outcomes with ROS modulator combinations with Chemotherapy and radiotherapy, indicating a need for additional pre-clinical research in the field. In this review, we discuss the current knowledge on the effect of ROS in the DNA damage response, and its clinical relevance.

miR-339-5p Increases Radiosensitivity of Lung Cancer Cells by Targeting Phosphatases of Regenerating Liver-1 (PRL-1)

BACKGROUND Radiotherapy is the most effective non-surgical modality in lung cancer treatment, and microRNAs (miRNAs) have been suggested as key regulators in radiosensitization. Herein, we explored the specific function of miR-339-5p in the radiosensitivity of lung cancer cells. MATERIAL AND METHODS Radiosensitivity was assessed by cell viability (CCK-8 assay), cell apoptosis, and cell cycle changes (flow cytometry). qRT-PCR and subsequent Western blot assays were used to determine the expression of miR-339-5p and other related proteins. RESULTS We demonstrated that ionizing radiation (IR) exposure impaired lung cancer cell viability, and found that miR-339-5p is a novel IR-inducible miRNA. Overexpression of miR-339-5p enhanced radiosensitivity of A549 and H460 cells by inhibiting cell viability, increasing apoptosis, inducing cell cycle arrest, and suppressing cell proliferation. Further exploration validated that miR-339-5p can target phosphatases of regenerating liver-1  (PRL-1) in lung cancer cells. Restoration of PRL-1 partially reverses the enhanced radiosensitivity of lung cancer cells induced by miR-339-5p. CONCLUSIONS Our data support that miR-339-5p has potential therapeutic value by sensitizing lung cancer cells to radiation via targeting of PRL-1.

Enhanced antitumor and anti-angiogenic effects of metronomic Vinorelbine combined with Endostar on Lewis lung carcinoma

Background

Conventional chemotherapy is commonly used to treat non-small cell lung cancer (NSCLC) however it increases therapeutic resistance. In contrast, metronomic chemotherapy (MET) is based on frequent drug administration at lower doses, resulting in inhibition of neovascularization and induction of tumor dormancy. This study aims to evaluate the inhibitory effects, adverse events, and potential mechanisms of MET Vinorelbine (NVB) combined with an angiogenesis inhibitor (Endostar).

Methods

Circulating endothelial progenitor cells (CEPs), apoptosis rate, expression of CD31, vascular endothelial growth factor (VEGF), hypoxia inducible factor-1 (HIF-1α) were determined using flow cytometry, western blot analysis, immunofluorescence staining and Enzyme-linked immunosorbent assay (ELISA) analysis. And some animals were also observed using micro fluorine-18-deoxyglucose PET/computed tomography (¹⁸F-FDG PET/CT) to identify changes by comparing SUVmax values. In addition, white blood cell (WBC) counts and H&E-stained sections of liver, lungs, kidney, and heart were performed in order to monitor toxicity assessments.

Results

We found that treatment with MET NVB + Endo was most effective in inhibiting tumor growth, decreasing expression of CD31, VEGF, HIF-1α, and CEPs, and reducing side effects, inducing apoptosis, such as expression of Bcl-2, Bax and caspase-3. Administration with a maximum tolerated dose of NVB combined with Endostar (MTD NVB + Endo) demonstrated similar anti-tumor effects, including changes in glucose metabolism with micro fluorine-18-deoxyglucose PET/computed tomography (¹⁸F-FDG PET/CT) imaging, however angiogenesis was not inhibited. Compared with either agent alone, the combination of drugs resulted in better anti-tumor effects.

Conclusion

These results indicated that MET NVB combined with Endo significantly enhanced anti-tumor and anti-angiogenic responses without overt toxicity in a xenograft model of human lung cancer.

Therapeutic efficacy and safety of Kang-ai injection combined with platinum-based doublet chemotherapy in advanced NSCLC: A meta-analysis

AIMS

Kang-ai injection (KA) is a famous Chinese patent medicine authorized by China Food and Drug Administration, which is widely used to treat advanced non-small cell lung cancer (NSCLC) in China. This meta-analysis is aimed to evaluate the therapeutic efficacy and safety of KA on advanced NSCLC.

METHODS

Seven databases were examined for related studies until January 15, 2018. Odds ratio (OR) was used to evaluate tumor response, Karnofsky Performance Scale (KPS) improvement and adverse reactions, and mean difference (MD) was used to estimate immune functions.

KEY FINDINGS

Thirty randomized controlled trials involving 1956 patients with advanced NSCLC were included. The results showed that compared with the platinum-based doublet chemotherapy (PBDC) alone, KA combined with PBDC could significantly enhance tumor response (OR = 1.69, 95% CI [1.40, 2.04], P < 0.00001), KPS improvement (OR = 3.01, 95% CI [2.36, 3.84], P < 0.00001) and immune functions including the percentages of CD₃⁺ (MD = 8.90, 95% CI [3.06, 14.73], P = 0.003), CD₄⁺ (MD = 9.43, 95% CI [6.32, 12.53], P < 0.00001) and NK (MD = 4.81, 95% CI [1.95, 7.68], P = 0.001) and the ratio of CD⁴⁺/CD⁸⁺ (MD = 0.29, 95% CI [0.04, 0.53], P = 0.02). Moreover, KA combined with PBDC markedly decreased the incidences of adverse reactions including gastrointestinal reaction (OR = 0.38, 95% CI [0.30, 0.47], P < 0.00001), myelosuppression (OR = 0.32, 95% CI [0.23, 0.45], P < 0.00001) and hair loss (OR = 0.53, 95% CI [0.36, 0.76], P < 0.00001). However, there was no significant difference between the combination treatment group and the control group in the percentage of CD₈⁺ (MD = -2.93, 95% CI [-6.68, 0.82], P = 0.13).

SIGNIFICANCE

Despite the small sample size and study limitations, the results of this meta-analysis indicated that the combination therapy of KA and PBDC (especially NP regimen) might be a beneficial therapeutic method for advanced NSCLC patients.

Conventional treatment integrated with Chinese herbal medicine improves the survival rate of patients with advanced non-small cell lung cancer

OBJECTIVES

The main objective of this study was to assess whether treatment with epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) combined with Chinese herbal medicine (CHM), can improve the five-year survival rate in patients suffering from advanced non-small cell lung cancer (NSCLC), compared to patients treated by EGFR-TKIs alone.

INTERVENTIONS AND MAIN OUTCOME MEASURES

The study is based on information in the sub-dataset of the National Health Insurance Research Database (NHIRD) from years 2000 to 2010, during which time a total of 14,244 patients were diagnosed with NSCLC in Taiwan. After selection by exclusion criteria and matching process, 2,616 NSCLC patients were included in the study. Statistical analysis was utilized to evaluate the differences in characteristic distribution, and to compare the survival rates between the CHM cohort and non-CHM cohort.

RESULTS

Patients with advanced NSCLC using CHM as an adjunct therapy exhibited a significantly improved survival rate [hazard ration (HR) = 0.8; 95% confidence interval (CI): 0.73-0.87, p value<0.001], compared with non-CHM users. Based on a survival analysis by Kaplan-Meier method, the 5-year survival rate of CHM users was 4.9% higher, with the most notable difference being an elevated 2-year survival rate of up to 12.75%. In addition to the survival rate analysis, we provide the ten most used single herbs and herbal formulas prescribed for patients with advanced NSCLC.

CONCLUSIONS

This nationwide retrospective cohort study provides evidence supporting CHM as an effective adjunctive therapy to ameliorate the side effects of target therapy and prolong the five-year survival rate of patients with advanced NSCLC.

A common CD55 rs2564978 variant is associated with the susceptibility of non-small cell lung cancer

CD55, as one of key membrane-bound complement-regulatory proteins (mCRPs), is crucial for the progression of various cancers. This study aims to investigate the role of CD55 variants in the development of non-small cell lung cancer (NSCLC). A case-control study, including 706 lung cancer cases and 706 health controls, was conducted in a Chinese population. The odds ratio (OR) and 95% confidence interval (95% CI) were estimated by unconditional logistic regression. We found that significantly higher lung cancer risk was linked with CD55 rs2564978 CC genotype (OR = 1.52, 95% CI = 1.11−2.07) or CT genotypes (OR = 1.34, 95% CI = 1.05−1.71), compared to the TT genotype. Stratified analysis showed that rs2564978 CC was associated with NSCLC risk among males (OR = 1.69, 95% CI = 1.14−2.49) and older subjects (OR = 1.75, 95% CI = 1.08−2.82). When stratified by smoking status, the risk effect of rs2564978 CC was more evident among smokers (OR = 2.01, 95% CI = 1.18−3.43) than non-smokers (OR = 1.30, 95% CI = 0.88−1.90). We also conducted the stratified analysis by NSCLC histological types and found that CD55 rs2564978 CC increased the risk of adenocarcinoma with OR (95% CI) of 1.35 (1.01−1.80). The reporter gene expression driven by rs2564978T-containing CD55 promoter was respectively 1.48-fold, 1.96-fold and 1.93-fold higher than those driven by the rs2564978C-containing CD55 promoter in A549, NCI-H2030 and NCI-H23 cells (P = 0.045, 0.010 and < 0.001). These findings indicate that CD55 rs2564978 polymorphism may contribute to an increased risk of NSCLC in Chinese population.

ROS-modulated therapeutic approaches in cancer treatment

PURPOSE

Reactive oxygen species (ROS) are produced in cancer cells as a result of increased metabolic rate, dysfunction of mitochondria, elevated cell signaling, expression of oncogenes and increased peroxisome activities. Certain level of ROS is required by cancer cells, above or below which lead to cytotoxicity in cancer cells. This biochemical aspect can be exploited to develop novel therapeutic agents to preferentially and selectively target cancer cells.

METHODS

We searched various electronic databases including PubMed, Web of Science, and Google Scholar for peer-reviewed english-language articles. Selected articles ranging from research papers, clinical studies, and review articles on the ROS production in living systems, its role in cancer development and cancer treatment, and the role of microbiota in ROS-dependent cancer therapy were analyzed.

RESULTS

This review highlights oxidative stress in tumors, underlying mechanisms of different relationships of ROS and cancer cells, different ROS-mediated therapeutic strategies and the emerging role of microbiota in cancer therapy.

CONCLUSION

Cancer cells exhibit increased ROS stress and disturbed redox homeostasis which lead to ROS adaptations. ROS-dependent anticancer therapies including ROS scavenging anticancer therapy and ROS boosting anticancer therapy have shown promising results in vitro as well as in vivo. In addition, response to cancer therapy is modulated by the human microbiota which plays a critical role in systemic body functions.

miR-21 modulates the effect of EZH2 on the biological behavior of human lung cancer stem cells in vitro

Non-small-cell lung cancer has a high mortality rate and poor prognosis. Therefore, novel therapeutic approaches are urgently needed to enhance patient survival rates. In this study, we investigated the effects of miR-21 and EZH2 on the biological behavior of human lung cancer stem cells in vitro. We found increased expression of EZH2 and miR-21 in LCSCs, and miR-21 overexpression increased EZH2 levels in LCSCs. In addition, EZH2 and miR-21 knockdown increased the sensitivity of LCSCs to chemo- and radiation therapy, and exogenous EZH2 expression rescued the effects of anti-miR-21. Cell proliferation was reduced by 39.2% and 69.7% in the presence of radio- or chemotherapy combined with anti-miR-21 transfection, respectively. The downstream molecules included Cdc2, cyclin B1, and Bcl-2, which are involved in the regulation of cell cycle and apoptosis and which could themselves be reduced or enhanced by changes in miR-21 and EZH2 levels in LCSCs. This study demonstrates the direct relationship between miR-21 and EZH2 which was increased by 43% after the application of the miR-21 mimic. Above data indicates that these two molecules can influence the biological behavior of LCSCs by altering their corresponding targets. Our findings support the potential roles of miR-21 and EZH2 in improving the therapeutic efficacy of clinical lung cancer treatments.

Downregulation of AATK mediates microRNA-558-induced resistance of A549 cells to radiotherapy

The deregulation of microRNAs (miRNAs) is often implicated in the control of sensitivity to radiotherapy. The objective of the present study was to identify the association between miR‑558 and apoptosis‑associated tyrosine kinase (AATK), and their importance in regulating the development of resistance to radiotherapy. The current study demonstrated that AATK, a radiosensitization-associated gene, is a target of miR‑558 in lung cancer cells, using in silico analysis and a luciferase reporter system. Furthermore, it was determined that transfection of 30 or 50 nM miR‑558 mimics and AATK specific siRNA markedly suppressed the mRNA and protein expression of AATK. To determine whether miR‑558 was required for lung cancer cell radioresistance, A549 cells were treated with different doses of ionizing radiation, from 0 to 10 Gy, following transfection with miR‑558 mimics or AATK specific siRNA. It was determined that the administration of miR‑558 mimics or AATK specific siRNA alone did not significantly alter the survival rate of the cells. By contrast, in the cells exposed to 4, 6 or 8 Gy, the administration of miR‑558 mimics or AATK specific siRNA significantly promoted cell survival rate and overexpression of AATK reversed this effect. In conclusion, these data demonstrate that the miR‑558/AATK cascade is important for the radiosensitization of lung cancer cells and may be a potential radiotherapy target.

miRNA-148b regulates radioresistance in non-small lung cancer cells via regulation of MutL homologue 1

miR-148b regulates radioresistance of lung cancer cells by modulating MLH1 expression level.

Radioresistance represents a major obstacle in cancer treatment, the underlying mechanism of which is complex and not well understood. miR-148b has been reported to be implicated regulating radioresistance in lymphoma cells. However, this function has not been investigated in lung cancer cells. Microarray analysis was performed in A549 cells 48 h after exposure to 8 Gy of γ-irradiation or sham irradiation to identify differentially expressed miRNAs. miR-148b mimic and inhibitor were transfected, followed by clonogenic survival assay to examine response to irradiation in A549 cells. Western Blot and luciferase assay were performed to investigate the direct target of miR-148b. Xenograft mouse models were used to examine in vivo function of miR-148b. Our data showed that expression of miR-148b was significantly down-regulated in both serum and cancerous tissues of radioresistant lung cancer patients compared with radiosensitive patients. Overexpression of miR-148b reversed radioresistance in A549 cells. MutL homologue 1 (MLH1) is the direct target of miR-148b which is required for the regulatory role of miR-148b in radioresistance. miR-148b mimic sensitized A549 xenografts to irradiation in vivo. Our study demonstrated that miR-148b regulates radioresistance of lung cancer cells by modulating MLH1 expression level. miR-148b may represent a new therapeutic target for the intervention of lung cancer.

Redox Homeostasis and Cellular Antioxidant Systems: Crucial Players in Cancer Growth and Therapy

Reactive oxygen species (ROS) and their products are components of cell signaling pathways and play important roles in cellular physiology and pathophysiology. Under physiological conditions, cells control ROS levels by the use of scavenging systems such as superoxide dismutases, peroxiredoxins, and glutathione that balance ROS generation and elimination. Under oxidative stress conditions, excessive ROS can damage cellular proteins, lipids, and DNA, leading to cell damage that may contribute to carcinogenesis. Several studies have shown that cancer cells display an adaptive response to oxidative stress by increasing expression of antioxidant enzymes and molecules. As a double-edged sword, ROS influence signaling pathways determining beneficial or detrimental outcomes in cancer therapy. In this review, we address the role of redox homeostasis in cancer growth and therapy and examine the current literature regarding the redox regulatory systems that become upregulated in cancer and their role in promoting tumor progression and resistance to chemotherapy.

Lung cancer in 2013: state of the art therapy for metastatic disease

Lung cancer is the leading worldwide cause of cancer death and the majority of patients present with metastatic stage IV disease. At diagnosis, clinical, histologic, and molecular features must be considered in therapeutic decision-making for systemic therapy. Molecular testing for at least epidermal growth factor receptor (EGFR) and ALK should be performed in all patients before therapy. Platinum doublet chemotherapy may be considered for "fit" patients who do not have a molecular driver genetic abnormality. Bevacizumab can be considered for addition to the doublet in patients with nonsquamous cancers who have no contraindications. A pemetrexed combination is considered only in nonsquamous histology. Patients with EGFR mutations or ALK fusions should be treated with erlotinib or crizotinib, respectively, even in patients with tumor-related poor performance. The tyrosine-kinase inhibitors (TKIs) may be continued until multisite, symptomatic progression. For patients initially treated with a platinum doublet, maintenance chemotherapy with pemetrexed, erlotinib, gemcitabine, or possibly docetaxel is an option with selection based on clinical features, histology, type of initial therapy, and response to first-line therapy.

Bayesian network meta-comparison of maintenance treatments for stage IIIb/IV non-small-cell lung cancer (NSCLC) patients with good performance status not progressing after first-line induction chemotherapy: results by performance status, EGFR mutation, histology and response to previous induction

BACKGROUND

Recent trials have suggested that maintenance treatments improve outcomes for patients not progressing after first-line therapy for advanced non-small-cell lung cancer (NSCLC). However, physicians have little guidance on selecting which patients benefit the most and what drug or regimen is optimal. Here, we report a systematic review and network meta-analysis of maintenance treatments in subgroups determined by performance status (PS), epidermal growth factor receptor (EGFR) mutation, histology and response to induction.

METHODS

PubMed and conference proceedings were reviewed and individual study relative efficacy measures were meta-analysed in a Bayesian hierarchical model. The primary outcome, overall survival (OS), was evaluated in terms of (i) posterior surface under cumulative ranking curve (SUCRA), (ii) probability of being best treatment, (iii) probability of outperforming no maintenance, and (iv) posterior median hazard ratio (95% credible interval). Secondary outcomes were progression-free survival (PFS) and adverse events.

FINDINGS

Twelve trials evaluating eight maintenance treatments in 3850 patients were meta-analysed. Selected maintenance treatments showed clinically meaningful benefits of ⩾20% reduction in hazards of death with ⩾90% probability of outperforming no maintenance in terms of OS: (i) switch to or continue pemetrexed (nonsquamous), continue gemcitabine, or switch to EGFR tyrosine kinase inhibitors (TKIs) for PS 0 patients, (ii) switch to pemetrexed (nonsquamous) for PS 1 patients, (iii) switch to EGFR TKI for EGFR mutation positive patients, (iv) switch to or continue pemetrexed or switch to EGFR TKI for nonsquamous patients, (v) continue gemcitabine for squamous patients, (vi) switch to docetaxel or continue gemcitabine for responders to induction, or (vii) switch to or continue pemetrexed (nonsquamous) or switch to EGFR TKI for patients with stable disease post-induction.

INTERPRETATION

Maintenance treatments show clinically meaningful survival benefits in good performance status patients with advanced NSCLC not progressing after first-line chemotherapy. Benefits are optimised by targeting specific maintenance to individual patients guided by PS, EGFR mutation status, histology and response to induction.

Design Issues in Randomized Clinical Trials of Maintenance Therapies

A potential therapeutic strategy for patients who respond (or have stable disease) on a fixed-duration induction therapy is to receive maintenance therapy, typically given for a prolonged period of time. To enable patients and clinicians to make informed treatment decisions, the designs of phase III randomized clinical trials (RCTs) assessing maintenance strategies need to be such that their results will provide clear assessment of the relevant risks and benefits of these strategies. We review the key aspects of maintenance RCT designs. Important design considerations include choice of first-line and second-line therapies, minimizing between-arm differences in follow-up schedules, and choice of the primary endpoint. In order to change clinical practice, RCTs should be designed to accurately isolate and quantify the clinical benefit of maintenance as compared with the standard approach of fixed-duration induction followed by the second-line treatment at progression. To accomplish this, RCTs need to utilize an overall survival (or quality of life) endpoint or, in settings where this is not feasible, endpoints that incorporate the effects of the subsequent line of therapy (eg, time from randomization to second progression or death). Toxicity and symptom information over both the study treatment (maintenance) and the second-line treatment should also be collected and reported.

A comparison of the biological effects of 125I seeds continuous low-dose-rate radiation and 60Co high-dose-rate gamma radiation on non-small cell lung cancer cells

Objectives

To compare the biological effects of ¹²⁵I seeds continuous low-dose-rate (CLDR) radiation and ⁶⁰Co γ-ray high-dose-rate (HDR) radiation on non-small cell lung cancer (NSCLC) cells.

Materials and Methods

A549, H1299 and BEAS-2B cells were exposed to ¹²⁵I seeds CLDR radiation or ⁶⁰Co γ-ray HDR radiation. The survival fraction was determined using a colony-forming assay. The cell cycle progression and apoptosis were detected by flow cytometry (FCM). The expression of the apoptosis-related proteins caspase-3, cleaved-caspase-3, PARP, cleaved-PARP, BAX and Bcl-2 were detected by western blot assay.

Results

After irradiation with ¹²⁵I seeds CLDR radiation, there was a lower survival fraction, more pronounced cell cycle arrest (G₁ arrest and G₂/M arrest in A549 and H1299 cells, respectively) and a higher apoptotic ratio for A549 and H1299 cells than after ⁶⁰Co γ-ray HDR radiation. Moreover, western blot assays revealed that ¹²⁵I seeds CLDR radiation remarkably up-regulated the expression of Bax, cleaved-caspase-3 and cleaved-PARP proteins and down-regulated the expression of Bcl-2 proteins in A549 and H1299 cells compared with ⁶⁰Co γ-ray HDR radiation. However, there was little change in the apoptotic ratio and expression of apoptosis-related proteins in normal BEAS-2B cells receiving the same treatment.

Conclusions

¹²⁵I seeds CLDR radiation led to remarkable growth inhibition of A549 and H1299 cells compared with ⁶⁰Co HDR γ-ray radiation; A549 cells were the most sensitive to radiation, followed by H1299 cells. In contrast, normal BEAS-2B cells were relatively radio-resistant. The imbalance of the Bcl-2/Bax ratio and the activation of caspase-3 and PARP proteins might play a key role in the anti-proliferative effects induced by ¹²⁵I seeds CLDR radiation, although other possibilities have not been excluded and will be investigated in future studies.

QoL analyses from INFORM study, a phase III study of gefitinib versus placebo as maintenance therapy in advanced NSCLC

This report aimed to provide the full results of QoL assessment in INFORM study. QoL was assessed by FACT-L questionnaire. QoL improvement ratio in gefitinib arm was higher than placebo arm (FACT-L: 46% vs. 22%, p < 0.001; TOI: 41% vs. 18%, p < 0.001; LCS: 46% vs. 22%, p < 0.001). Gefitinib prolonged time-to-worsening of QoL (FACT-L: 2.8 m vs 1.4 m, p = 0.019; TOI: 3.5 m vs 1.4 m, p = 0.006; LCS: 2.8 vs 1.4 m, p = 0.028). Patients with an improvement in QoL had longer PFS (FACT-L: 9.4 m vs. 2.8 m vs. 2.7 m, P < 0.001; TOI: 9.9 m vs. 2.8 m vs. 2.1 m, P < 0.001; LCS: 9.4 m vs. 2.9 m vs. 2.1 m, P < 0.001) and OS (FACT-L: 25.4 m vs. 19.9 m vs. 14.4 m, P = 0.003; TOI: 25.7 m vs. 19.0 m vs. 12.7 m, P = 0.002; LCS: 25.4 m vs. 19.3 m vs. 14.7 m, P = 0.004) compared with patients with stable or worsened QoL. Furthermore, in patients with good QoL at baseline, the treatment of gefitinib couldn't improve OS compared to placebo, whereas patients with low QoL experienced marginal significant improvement in OS (20.6 m vs 14.4, p = 0.051). Our study indicated that gefitinib could improve patients' QoL, confirmed the prognostic value of QoL changes during treatment, and implied patients with low QoL at baseline may be the potential population which will gain OS benefit from maintenance EGFR-TKI therapy.

High performance liquid chromatography: Tandem mass spectrometric determination of cisplatin levels in different visceral pleura layers of rats

The aim of the present study was to investigate the concentration of cisplatin in different layers of the visceral pleura in rats, following drug administration. In this study, a sensitive and specific liquid chromatography method coupled with electrospray ionization-tandem mass spectrometry was established to investigate the disposition of cisplatin in different layers of the visceral pleura in rats. Methodological data, including specificity, linearity, accuracy, recovery, precision and lower limits of quantification, confirmed that this novel method may be used to efficiently quantify the cisplatin concentrations in visceral pleura of rats following administration of the drug. Furthermore, the results demonstrated that the desired drug concentration was not achieved in the outer or inner elastic layers of the visceral pleura following injection with cisplatin through various administration methods.

Anticancer effects of adenovirus-mediated calreticulin and melanoma-associated antigen 3 expression on non-small cell lung cancer cells

Non-small cell lung cancer (NSCLC) is highly prevalent and needs novel therapies. Melanoma-associated antigen 3 (MAGE-A3) is a lung cancer antigen and calreticulin (CALR) can modulate immune responses. Our previous study has shown that up-regulated MAGE-A3 and CALR expression inhibits the proliferation and invasion of glioma cells. In this study, we examined the effect of adenovirus (Ad)-mediated MAGE-A3 and/or CALR expression on the proliferation, invasion, and apoptosis of human NSCLC cells and on the vascular tube formation of human endothelial cells as well as on dendritic cell (DC) activation and induced CD8(+) cytotoxic T lymphocyte (CTL) activity in vitro. We found that low levels of CALR and MAGE-A3 were expressed by A549 cells, but only very low CALR was expressed by DC. Up-regulated CALR and MAGE-A3 expression by infection with Ad-CALR/MAGE-A3 significantly inhibited the proliferation and invasion, but promoted the apoptosis of A549 cells. Up-regulated CALR and MAGE-A3 expression significantly inhibited cyclin D1 expression and the AKT, ERK1/2 and NF-κB expression and phosphorylation in A549 cells. Up-regulated CALR expression inhibited the tube formation in human endothelial cells. Up-regulated CALR and MAGE-A3 expression synergistically enhanced classical DC activation by enhancing IL-12, but reducing IL-10 secretion. Furthermore, CTLs induced by up-regulated CALR and MAGE-A3 expressing DCs synergistically triggered A549 cell apoptosis, which was abrogated by treatment with anti-HLA I, but not anti-HLA II antibodies. Moreover, CTLs induced by CALR and MAGE-A3-expressing DCs had a higher frequency of A549-specific IFN-γ-secreting T cells. Our data indicated that up-regulated CALR and MAGE-A3 expression inhibited the carcinogenesis of NSCLC by modulating the AKT, ERK MAPK and NF-κB signaling and enhanced classical DC activation and MAGE-A3-specific CTL cytotoxicity. Therefore, our findings may provide new insights in understanding the role of CALR in modulating antigen-specific T cell immunity and may aid in the design of new therapies for NSCLC.

miR-25 modulates NSCLC cell radio-sensitivity through directly inhibiting BTG2 expression

A large proportion of the NSCLC patients were insensitive to radiotherapy, but the exact mechanism is still unclear. This study explored the role of miR-25 in regulating sensitivity of NSCLC cells to ionizing radiation (IR) and its downstream targets. Based on measurement in tumor samples from NSCLC patients, this study found that miR-25 expression is upregulated in both NSCLC and radio-resistant NSCLC patients compared the healthy and radio-sensitive controls. In addition, BTG expression was found negatively correlated with miR-25a expression in the both tissues and cells. By applying luciferase reporter assay, we verified two putative binding sites between miR-25 and BTG2. Therefore, BTG2 is a directly target of miR-25 in NSCLC cancer. By applying loss-and-gain function analysis in NSCLC cell lines, we demonstrated that miR-25-BTG2 axis could directly regulated BTG2 expression and affect radiotherapy sensitivity of NSCLC cells.

Lower mean corpuscular hemoglobin concentration is associated with unfavorable prognosis of resected lung cancer

ABSTRACT 

Background: The association of preoperative red blood cell indexes in non-anemic patients undergoing lung resections for non-small-cell lung cancer with recurrence-free survival (RFS) and overall survival (OS) has never been investigated. Methods: We retrospectively examined the impact of preoperative red blood cell indexes on RFS and OS and the relationships between the indexes and clinicopathological factors in lung cancer. Results: A total of 649 patients were evaluated. The mean corpuscular hemoglobin concentration was showed as an independent prognostic factor in all patients for OS (hazard ratio [HR]: 0.697; 95% CI: 0.502–0.969; p = 0.032) and RFS (HR: 0.688; 95% CI: 0.519–0.914; p = 0.010). The mean corpuscular volume was an independent prognostic factor in all patients for OS (HR: 0.589; 95% CI: 0.380–0.912; p = 0.018), but not for RFS (HR: 0.684; 95% CI: 0.461–1.015; p = 0.059). Conclusion: In conclusion, the results of this study suggest that mean corpuscular hemoglobin concentration is an independent prognostic factor for OS and RFS in non-small-cell lung cancer.

The possibility of traditional chinese medicine as maintenance therapy for advanced nonsmall cell lung cancer

Lung cancer has become the leading cause of cancer deaths, with nonsmall cell lung cancer (NSCLC) accounting for around 80% of lung cancer cases. Chemotherapy is the main conventional therapy for advanced NSCLC. However, the disease control achieved with classical chemotherapy in advanced NSCLC is usually restricted to only a few months. Thus, sustaining the therapeutic effect of first-line chemotherapy is an important problem that requires study. Maintenance therapy is given for patients with advanced NSCLC if three is no tumor progression after four to six cycles of first-line platinum-based chemotherapy. However, selection of appropriate maintenance therapy depends on several factors, while traditional Chinese medicine (TCM) as maintenance therapy is recommended for all kinds of patients. It has been demonstrated that TCM can prolong the survival time, improve the quality of life (QOL), and reduce the side effects for advanced NSCLC. Although the trials we searched about TCM serving as maintenance therapy is only 9 studies, the results indicate TCM can prolong the progression free survival (PFS) and improve the QOL. So it is possible for TCM to be as maintenance therapy for advanced NSCLC. More rigorous trials are required to further verify its efficacy.

Pemetrexed in non-small-cell lung cancer

SUMMARY 

Pemetrexed, a multitargeted antifolate agent, is currently used in the treatment of non-small-cell lung cancer. Strong evidence has shown a treatment-by-histology interaction, with pemetrexed acting significantly better in the nonsquamous cell subtype. Therefore, all pemetrexed indications are restricted to this histology. Associated initially with somewhat high toxicity, the use of vitamin supplementation and corticoid premedication turned pemetrexed into one of the most convenient chemotherapy agents. At present pemetrexed is recommended as one of the preferred platinum partners in first line and as a single agent in the second-line setting for nonsquamous histology. The particular efficacy/toxicity profile has confirmed pemetrexed as the only chemotherapy agent approved for both continuation and switch maintenance therapy.

Silencing miR-21 sensitizes non-small cell lung cancer A549 cells to ionizing radiation through inhibition of PI3K/Akt

We investigated the role of microRNA-21 (miR-21) in radiotherapy resistance of non-small cell lung cancers (NSCLC) and the underlying molecular mechanism. A549 cells were transfected with anti-miR-21 or the negative control oligonucleotides and real-time PCR was applied to detect miR-21 expression level. After ionizing radiation (IR), the survival fractions, proliferation, apoptosis, and expression of phosphorylated-Akt of A549 cells were determined by clonogenic survival analysis, MTT assay, flow cytometry, and Western blotting. Downregulation of miR-21 in radioresistant NSCLC A549 cells inhibited the colony-forming ability and proliferation of A549 cells after IR. Moreover, silencing miR-21 enhanced apoptosis of A549 cells induced by IR accompanied by decreased phosphorylated-Akt protein level. However, PI3K activator IGF-1 reversed suppression of phosphorylated-Akt protein level and promotion of apoptosis of A549 cells after IR caused by miR-21 knockdown. Silencing miR-21 in radioresistant NSCLC A549 cells sensitized them to IR by inhibiting cell proliferation and enhancing cell apoptosis through inhibition of PI3K/Akt signaling pathway. This might help in sensitization of NSCLC to radiotherapy.

EZH2 silencing with RNA interference induces G2/M arrest in human lung cancer cells in vitro

Nonsmall-cell lung cancer has a high mortality rate and poor prognosis. In the present study, we silenced EZH2 and explored the consequent cell cycle changes. The expression of cell-cycle-related proteins, including p53, p21, Cdc2, and cyclin B1, was detected with western blotting, and the cell cycle distribution was determined with flow cytometry. Inhibition of EZH2 expression changed the cell cycle distribution, in particular inducing G₂/M arrest. Expression of Cdc2 and cyclin B1 was significantly decreased in A549 and HTB-56 cells after EZH2-siRNA treatment. In addition, p53 expression was increased by 21% and 18%, and p21 expression was increased by 31% and 23%, in A549 and HTB-56 cells, respectively, in the presence of EZH2-siRNA. This study clearly demonstrates that modulation of EZH2 expression with siRNA affects the cell cycle and the expression levels of p53 and p21, thereby changing cyclin B1 and Cdc2 expression and inducing G₂/M arrest. These results may explain the observed antitumor activity of EZH2 silencing. Such explorations of the molecular mechanism of EZH2 will help us develop novel approaches to the diagnosis, treatment, and prevention of nonsmall-cell lung cancer.

Efficacy of pemetrexed as second-line therapy in advanced NSCLC after either treatment-free interval or maintenance therapy with gemcitabine or erlotinib in IFCT-GFPC 05-02 phase III study

INTRODUCTION

Maintenance therapy in advanced non-small-cell lung cancer (NSCLC) might lead to resistance to subsequent treatments. IFCT-GFPC 0502 study showed a progression-free survival (PFS) benefit with gemcitabine or erlotinib maintenance compared with observation after cisplatin-gemcitabine chemotherapy. The trial included a pre-defined pemetrexed second-line therapy, allowing post-hoc assessment of its efficacy according to previous maintenance treatment or treatment-free interval.

METHODS

Stage IIIB/IV NSCLC patients were randomized after four cycles of cisplatin-gemcitabine chemotherapy to either observation or to receive maintenance therapy with gemcitabine or erlotinib. Pemetrexed was given as second-line treatment on disease progression in all arms. PFS and overall survival (OS) were assessed from the beginning of pemetrexed therapy according to randomization arm.

RESULTS

Of the 464 randomized patients, 360 (78 %) received second-line pemetrexed (130 [84%], 114 [74%], and 116 [75%] in observation, gemcitabine, and erlotinib arm, respectively). Median number of pemetrexed cycles was 3 (1-40) in all arms. Median PFS did not differ between gemcitabine and observation arms (4.2 versus 3.9 months, hazard ratio [HR] [95% confidence interval [CI] 0.81 [0.62-1.06]) or between erlotinib and observation arms (4.2 versus 3.9 months, HR 0.83 [0.64-1.09]). OS data showed a non-significant improvement with gemcitabine arm versus observation arm (8.3 versus 7.5 months, HR 0.81 [0.61-1.07]) or erlotinib arm versus observation arm (9.1 versus 7.5 months, HR 0.80 [0.61-1.05]). Results were similar for non-squamous patients. Grade 3 to 4 treatment-related adverse events (AEs) were comparable in all arms.

CONCLUSIONS

Maintenance therapy with gemcitabine continuation or erlotinib does not seem to impair efficacy of second-line pemetrexed comparatively to administration after a treatment-free interval.

VATS lobectomy facilitates the delivery of adjuvant docetaxel-carboplatin chemotherapy in patients with non-small cell lung cancer

BACKGROUND

To evaluate the safety and tolerability of docetaxel/carboplatin regimen in the post-operative setting of patients with non-small cell lung cancer (NSCLC).

METHODS

Enrolment of 133 patients with stage Ib - IIIa NSCLC was undertaken in an open-label, single arm study to assess the safety and tolerability of docetaxel (75 mg/kg) and carboplatin (AUC 5.5) administered for 3 cycles after resection for curative intent. The primary endpoint of the study was safety, as reflected by a febrile neutropenia rate of <10%. Other endpoints assessed protocol compliance and the impact of minimally invasive surgical technique.

RESULTS

Patient accrual was completed at 1 center in the US and 10 centers in China in <6 months. Febrile neutropenia complicated treatment in 12 patients (9.0%), below the predetermined safety threshold of 14 patients. Four VATS and 8 open thoracotomy patients experienced febrile neutropenia (P=0.26). Completion of the three-cycle adjuvant regimen was achieved in 86% (95% CI, 77-95%) of patients. Sixty-two of 66 VATS patients compared to 53 of 67 open thoracotomy patients received all three doses according to protocol (P<0.01). Thirteen serious adverse events (9.8%) and no deaths were attributed to the study regimen.

CONCLUSIONS

In this rapidly accrued study, docetaxel and carboplatin were well-tolerated in the adjuvant treatment of NSCLC. Adjuvant treatment compliance was higher among patients undergoing a minimally invasive surgical approach. (ClinicalTrials.gov number NCT00883675).

NBN Gene Polymorphisms and Cancer Susceptibility: A Systemic Review

The relationship between DNA repair failure and cancer is well established as in the case of rare, high penetrant genes in high cancer risk families. Beside this, in the last two decades, several studies have investigated a possible association between low penetrant polymorphic variants in genes devoted to DNA repair pathways and risk for developing cancer. This relationship would be also supported by the observation that DNA repair processes may be modulated by sequence variants in DNA repair genes, leading to susceptibility to environmental carcinogens. In this framework, the aim of this review is to provide the reader with the state of the art on the association between common genetic variants and cancer risk, limiting the attention to single nucleotide polymorphisms (SNPs) of the NBN gene and providing the various odd ratios (ORs). In this respect, the NBN protein, together with MRE11 and RAD50, is part of the MRN complex which is a central player in the very early steps of sensing and processing of DNA double-strand breaks (DSBs), in telomere maintenance, in cell cycle control, and in genomic integrity in general. So far, many papers were devoted to ascertain possible association between common synonymous and non-synonymous NBN gene polymorphisms and increased cancer risk. However, the results still remain inconsistent and inconclusive also in meta-analysis studies for the most investigated E185Q NBN miscoding variant.

The impact of personalized medicine on survival: comparisons of results in metastatic breast, colorectal and non-small-cell lung cancers

Breast, colorectal and lung cancers represent the three most incident forms of cancer worldwide. Among these three "big killers", lung cancer is considered the one with the worst prognosis due to its high mortality even in early stages. Due to their more favorable prognosis, breast and colorectal cancers might appear to have benefited from major advances. Most oncologists who are faced with metastatic non-small cell lung cancer (NSCLC) find the reported results very frustrating when compared with those for metastatic breast (MBC) and colorectal cancers (MCRC). The aim of this analysis was to quantify and compare the relative magnitude of overall survival (OS) improvements in the first-line approaches in metastatic NSCLC, MBC and MCRC through the analysis of the main landmark meta-analyses and randomized clinical trials (RCTs) of commercially available drugs. Five items were considered and analyzed for each cancer. Moreover we evaluated the real clinical impact of the results reported by each item on the entire population; for each "big killer" an overall hazard ratio (HR) was estimated: 0.88 (95%(+) CI: 0.72-1.07) for MBC, 0.94 (95%(+) CI: 0.82-1.07) for MCRC, and about 0.80 (95%(+) CI: 0.73-0.90) for advanced NSCLC. We showed that, in the last decades, these three tumors had important and constant OS improvements reached step by step. The relative magnitude of OS improvement seems higher in metastatic NSCLC than MBC and MCRC.

PARAMOUNT: Final overall survival results of the phase III study of maintenance pemetrexed versus placebo immediately after induction treatment with pemetrexed plus cisplatin for advanced nonsquamous non-small-cell lung cancer

PURPOSE

In the phase III PARAMOUNT trial, pemetrexed continuation maintenance therapy reduced the risk of disease progression versus placebo (hazard ratio [HR], 0.62; 95% CI, 0.49 to 0.79; P < .001). Here we report final overall survival (OS) and updated safety data.

PATIENTS AND METHODS

In all, 939 patients with advanced nonsquamous non-small-cell lung cancer (NSCLC) received four cycles of pemetrexed-cisplatin induction therapy; then, 539 patients with no disease progression and Eastern Cooperative Oncology Group performance status 0 or 1 were randomly assigned (2:1) to maintenance pemetrexed (500 mg/m(2) on day 1 of 21-day cycles; n = 359) or placebo (n = 180). Log-rank test compared OS between arms as measured from random assignment (α = .0498).

RESULTS

The mean number of maintenance cycles was 7.9 (range, one to 44) for pemetrexed and 5.0 (range, one to 38) for placebo. After 397 deaths (pemetrexed, 71%; placebo, 78%) and a median follow-up of 24.3 months for alive patients (95% CI, 23.2 to 25.1 months), pemetrexed therapy resulted in a statistically significant 22% reduction in the risk of death (HR, 0.78; 95% CI, 0.64 to 0.96; P = .0195; median OS: pemetrexed, 13.9 months; placebo, 11.0 months). Survival on pemetrexed was consistently improved for all patient subgroups, including induction response: complete/partial responders (n = 234) OS HR, 0.81; 95% CI, 0.59 to 1.11 and stable disease (n = 285) OS HR, 0.76; 95% CI, 0.57 to 1.01). Postdiscontinuation therapy use was similar: pemetrexed, 64%; placebo, 72%. No new safety findings emerged. Drug-related grade 3 to 4 anemia, fatigue, and neutropenia were significantly higher in pemetrexed-treated patients.

CONCLUSION

Pemetrexed continuation maintenance therapy is well-tolerated and offers superior OS compared with placebo, further demonstrating that it is an efficacious treatment strategy for patients with advanced nonsquamous NSCLC and good performance status who did not progress during pemetrexed-cisplatin induction therapy.

Role of glutathione in cancer progression and chemoresistance

Glutathione (GSH) plays an important role in a multitude of cellular processes, including cell differentiation, proliferation, and apoptosis, and disturbances in GSH homeostasis are involved in the etiology and progression of many human diseases including cancer. While GSH deficiency, or a decrease in the GSH/glutathione disulphide (GSSG) ratio, leads to an increased susceptibility to oxidative stress implicated in the progression of cancer, elevated GSH levels increase the antioxidant capacity and the resistance to oxidative stress as observed in many cancer cells. The present review highlights the role of GSH and related cytoprotective effects in the susceptibility to carcinogenesis and in the sensitivity of tumors to the cytotoxic effects of anticancer agents.

Identifying the target NSCLC patient for maintenance therapy: an analysis from a placebo-controlled, phase III trial of maintenance pemetrexed (H3E-MC-JMEN)

Background

This was a post hoc analysis of patients with non-squamous histology from a phase III maintenance pemetrexed study in advanced non-small cell lung cancer (NSCLC).

Patients and methods

The six symptom items' [average symptom burden index (ASBI)] mean at baseline was calculated using the lung cancer symptom scale (LCSS). Low and high symptom burden (LSB, ASBI < 25; HSB, ASBI ≥ 25) and performance status (PS: 0, 1) subgroups were analyzed for treatment effect on progression-free survival (PFS) and overall survival (OS) using the Cox proportional hazard models adjusted for demographic/clinical factors.

Results

Significantly longer PFS and OS for pemetrexed versus placebo occurred in LSB patients [PFS: median 5.1 versus 2.4 months, hazard ratio (HR) 0.49, P < 0.0001; OS: median 17.5 versus 11.0 months, HR 0.63, P = 0.0012] and PS 0 patients (PFS: median 5.5 versus 1.7 months, HR 0.36, P < 0.0001; OS: median 17.7 versus 10.3 months, HR 0.54, P = 0.0019). Significantly longer PFS, but not OS, occurred in HSB patients (median 3.7 versus 2.8 months, HR 0.50, P = 0.0033) and PS 1 patients (median 4.4 versus 2.8 months, HR 0.60, P = 0.0002).

Conclusions

ASBI and PS are associated with survival for non-squamous NSCLC patients, suggesting that maintenance pemetrexed is useful for LSB or PS 0 patients following induction.

Association between the NBS1 Glu185Gln polymorphism and lung cancer risk: a systemic review and meta-analysis

Nijmegen Breakage Syndrome protein 1 (NBS1) is one of the most important DNA repair proteins playing important roles in maintaining the genomic stability of NDA. Previous studies regarding the association between NBS1 8360G>C (Glu185Gln) polymorphism and lung cancer reported conflicting results. To derive a more precise estimation of this association, a systemic review and meta-analysis was performed. We performed a meta-analysis using eligible case-control studies to summarize the data on the association between the NBS1 Glu185Gln polymorphism and lung cancer risk. Odds ratios (ORs) with corresponding 95 % confidence intervals (95 %CIs) were pooled to assess the association between NBS1 Glu185Gln polymorphism and lung cancer risk. Six case-control studies with a total of 2,348 lung cancer cases and 2,401 controls without canner were included into the meta-analysis. Overall, there was an association between NBS1 Glu185Gln polymorphism and lung cancer risk under the dominant comparison model (fixed-effects OR GluGln/GlnGln vs. GluGlu = 1.21, 95 % CI 1.07-1.37, P = 0.002, I (2) = 8.1 %). Subgroup analysis by race suggested a significant association between NBS1 Glu185Gln polymorphism and lung cancer risk in Asians (fixed-effects OR GluGlnGlnGln vs. GluGlu = 1.22, 95 % CI 1.06-1.41, P = 0.005) but not in Caucasians (fixed-effects OR GluGlnGlnGln vs. GluGlu = 1.17, 95 % CI 0.91-1.50, P = 0.220). This meta-analysis supports that there is an association between NBS1 Glu185Gln polymorphism and lung cancer risk. More studies are needed to further verify this association.

Role of erlotinib in the treatment of non-small cell lung cancer: clinical outcomes in wild-type epidermal growth factor receptor patients

Erlotinib is an orally administered small molecule inhibitor of epidermal growth factor receptor (EGFR) tyrosine kinase. Erlotinib at the standard oral daily dose of 150 mg is approved for the treatment of unselected chemorefractory advanced non-small cell lung cancer patients as well as maintenance therapy after first-line chemotherapy. The European Medicines Agency has recently also approved erlotinib as the first-line therapy in patients with EGFR mutations. Although recent studies have identified higher response rates and improved survival with erlotinib in a subset of patients with EGFR mutations, the survival benefit from single agent erlotinib in chemorefractory patients and in the maintenance setting is well observed in EGFR wild-type patients. The role of single agent erlotinib in the first-line setting in special subsets of EGFR wild-type patients (elderly, poor performance status, non-smokers) needs to be further determined. The combination of erlotinib with other targeted therapies has shown promising results and warrants further studies in EGFR wild-type patients.

Randomized, phase III study of gemcitabine or erlotinib maintenance therapy versus observation, with predefined second-line treatment, after cisplatin-gemcitabine induction chemotherapy in advanced non-small-cell lung cancer

PURPOSE

This phase III study investigated whether continuation maintenance with gemcitabine or switch maintenance with erlotinib improves clinical outcome compared with observation in patients with advanced non-small-cell lung cancer (NSCLC) whose disease was controlled after cisplatin-gemcitabine induction chemotherapy.

PATIENTS AND METHODS

Four hundred sixty-four patients with stage IIIB/IV NSCLC without tumor progression after four cycles of cisplatin-gemcitabine were randomly assigned to observation or to gemcitabine (1,250 mg/m(2) days 1 and 8 of a 3-week cycle) or daily erlotinib (150 mg/day) study arms. On disease progression, patients in all three arms received pemetrexed (500 mg/m(2) once every 21 days) as predefined second-line therapy. The primary end point was progression-free survival (PFS).

RESULTS

PFS was significantly prolonged by gemcitabine (median, 3.8 v 1.9 months; hazard ratio [HR], 0.56; 95% CI, 0.44 to 0.72; log-rank P < .001) and erlotinib (median, 2.9 v 1.9 months; HR, 0.69; 95% CI, 0.54 to 0.88; log-rank P = .003) versus observation; this benefit was consistent across all clinical subgroups. Both maintenance strategies resulted in a nonsignificant improvement in overall survival (OS); patients who received second-line pemetrexed or with a performance status of 0 appeared to derive greater benefit. Exploratory analysis showed that magnitude of response to induction chemotherapy may affect the OS benefit as a result of gemcitabine maintenance. Maintenance gemcitabine and erlotinib were well tolerated with no unexpected adverse events.

CONCLUSION

Gemcitabine continuation maintenance or erlotinib switch maintenance significantly reduces disease progression in patients with advanced NSCLC treated with cisplatin-gemcitabine as first-line chemotherapy. Response to induction chemotherapy may affect OS only for continuation maintenance.

Proposal for a novel methodology to screen and score cost versus survival for anticancer drugs in metastatic disease: could cost weigh in evaluation?

PURPOSE

Rising costs of anticancer drugs prompt concerns about their approval, use, and affordability. A methodology was developed to evaluate cost versus survival for anticancer drugs in metastatic breast cancer and non-small-cell lung cancer (NSCLC).

METHODS

Costs of evaluated drugs were calculated by using average wholesale prices in US dollars. Ratios of cost to day of survival (cost/survival/d) were obtained by dividing costs of the entire treatment by reported median survival gain in days. A crude score of 100% was assigned to a cost/survival/d of less than $25, and 0% to a cost/survival/d of more than $750. A strategy was designed to correct for overall survival (OS) versus progression-free survival (PFS), adverse effects, and quality of life.

RESULTS

In breast cancer, PFS scores of bevacizumab varied between 0% and 60%. In NSCLC, OS scores of bevacizumab improved from 0% to 50%, as a result of histology, lower prices, and extended therapy. Gefitinib and erlotinib PFS scores were 80% and 70%, respectively. Correction for longer survival with erlotinib resulted in similar scores. In maintenance therapy, the OS score for pemetrexed was 70% as compared with 25% for erlotinib. Generic drugs scored 70% to 90%.

CONCLUSION

Cost/survival varied with the number of cycles. In breast cancer, bevacizumab scores failed to justify its use. In NSCLC, 10 cycles of bevacizumab scored 0%. Scores improved with extended treatment and lower prices. Scores for gefitinib and erlotinib would support their approval. Erlotinib was preferred because of longer PFS. Results tended to endorse maintenance pemetrexed but not erlotinib. Generic drugs demonstrated high scores. Cost/survival could weigh in drug evaluation.

Enhanced anti-tumor and anti-angiogenic effects of metronomic cyclophosphamide combined with Endostar in a xenograft model of human lung cancer

Standard chemotherapy for advanced NSCLC has reached a therapeutic plateau. More effective strategies must be explored. The purpose of this study was to evaluate the role of metronomic chemotherapy combined with an angiogenesis inhibitor in non-small cell lung cancer (NSCLC). A total of 114 BALB/c nude mice were inoculated subcutaneously with human NSCLC cells (A549), and when xenograft tumors were palpable, mice were randomly injected with saline as controls (Ctrl), or treated with metronomic cyclophosphamide (MET CPA), recombinant human endostatin, Endostar (Endo), MET CPA combined with Endostar (MET CPA + Endo) or maximum tolerance dose of CPA (MTD CPA), respectively. The growth of xenograft tumors and mouse survival were monitored. The frequency of peripheral blood circulating endothelial cells (CECs), microvessel density (MVD) and pericyte coverage was determined using flow cytometry and immunofluorescence staining. In comparison with the controls, treatment with either drug significantly inhibited the growth of xenograft tumors in mice. Treatment with MET CPA or Endostar, but not with MTD CPA, significantly reduced the frequency of peripheral blood total and viable CECs and the value of MVD. Endostar also considerably reduced pericyte coverage in xenograft tumors. Moreover, MET CPA combined with Endostar further reduced the frequency of peripheral blood CECs, the value of MVD, and pericyte coverage, with concomitant delay in tumor growth and extension of mouse survival. Our results indicate that MET CPA combined with Endostar results in enhanced anti-tumor and anti-angiogenic effects in a xenograft model of human lung cancer. Combined therapy with metronomic chemotherapy and an angiogenesis inhibitor may serve as a promising treatment strategy for patients with advanced NSCLC.

EZH2 silencing with RNAi enhances irradiation-induced inhibition of human lung cancer growth in vitro and in vivo

Non-small cell lung cancer (NSCLC) has a high mortality rate and poor prognosis. The aim of the present study was to silence EZH2 and explore the antitumor effect of small interfering RNA (siRNA)-EZH2 in combination with radiotherapy, which is a main treatment for NSCLC. The results showed that irradiation in the presence of siRNA-EZH2 arrested A549 cells in the G(0) and G(1) phases, delayed cell cycle progression and effectively inhibited cell proliferation, compared with cells that received radiotherapy alone. The combined therapy enhanced the percentage of apoptotic A549 cells in vitro and reduced the tumor size, in addition to increasing the survival rate in tumor xenograft experiments. This study demonstrates the antitumor activity of ionizing radiation therapy in combination with siRNA-EZH2 in NSCLC, both in vitro and in vivo, as well as providing a scientific rationale for targeting EZH2 to enhance the sensitivity of cancer to radiotherapy in NSCLC patients.

ERK3 signals through SRC-3 coactivator to promote human lung cancer cell invasion

In contrast to the well-studied classic MAPKs, such as ERK1/2, little is known concerning the regulation and substrates of the atypical MAPK ERK3 signaling cascade and its function in cancer progression. Here, we report that ERK3 interacted with and phosphorylated steroid receptor coactivator 3 (SRC-3), an oncogenic protein overexpressed in multiple human cancers at serine 857 (S857). This ERK3-mediated phosphorylation at S857 was essential for interaction of SRC-3 with the ETS transcription factor PEA3, which promotes upregulation of MMP gene expression and proinvasive activity in lung cancer cells. Importantly, knockdown of ERK3 or SRC-3 inhibited the ability of lung cancer cells to invade and form tumors in the lung in a xenograft mouse model. In addition, ERK3 was found to be highly upregulated in human lung carcinomas. Our study identifies a previously unknown role for ERK3 in promoting lung cancer cell invasiveness by phosphorylating SRC-3 and regulating SRC-3 proinvasive activity by site-specific phosphorylation. As such, ERK3 protein kinase may be an attractive target for therapeutic treatment of invasive lung cancer.