Recent advances of novel targeted therapy in non-small cell lung cancer

Comprehensive landscape of junctional genes and their association with overall survival of patients with lung adenocarcinoma

Objectives

Junctional proteins are involved in tumorigenesis. Therefore, this study aimed to investigate the association between junctional genes and the prognosis of patients with lung adenocarcinoma (LUAD).

Methods

Transcriptome, mutation, and clinical data were retrieved from The Cancer Genome Atlas (TCGA). "Limma" was used to screen differentially expressed genes. Moreover, Kaplan-Meier survival analysis was used to identify junctional genes associated with LUAD prognosis. The junctional gene-related risk score (JGRS) was generated based on multivariate Cox regression analysis. An overall survival (OS) prediction model combining the JGRS and clinicopathological properties was proposed using a nomogram and further validated in the Gene Expression Omnibus (GEO) LUAD cohort.

Results

To our knowledge, this study is the first to demonstrate the correlation between the mRNA levels of 14 junctional genes (CDH15, CDH17, CDH24, CLDN6, CLDN12, CLDN18, CTNND2, DSG2, ITGA2, ITGA8, ITGA11, ITGAL, ITGB4, and PKP3) and clinical outcomes of patients with LUAD. The JGRS was generated based on these 14 genes, and a higher JGRS was associated with older age, higher stage levels, and lower immune scores. Thus, a prognostic prediction nomogram was proposed based on the JGRS. Internal and external validation showed the good performance of the prediction model. Mechanistically, JGRS was associated with cell proliferation and immune regulatory pathways. Mutational analysis revealed that more somatic mutations occurred in the high-JGRS group than in the low-JGRS group.

Conclusion

The association between junctional genes and OS in patients with LUAD demonstrated by our "TCGA filtrating and GEO validating" model revealed a new function of junctional genes.

Augmented antitumor effects of erlotinib and cabozantinib on A549 non-small cell lung cancer: In vitro and in vivo studies

Non-small cell lung carcinoma is a challenging disease worldwide. This study aims to determine whether combining erlotinib, an epidermal growth factor receptor (EGFR) inhibitor, with cabozantinib, a mesenchymal-epithelial transition factor (c-Met) inhibitor, would have an augmented therapeutic benefit on A549 cells. The combination of erlotinib and cabozantinib (5 µM) inhibited A549 cell viability compared to each monotherapy at ≥ 10 µM as confirmed by the MTT assay. Combination therapy also has a more potent inhibition of cellular migration than monotherapy using the wound-healing assay. Furthermore, mRNA expression analyses for assessing apoptosis, metastasis, and cell cycle-related genes, the results showed that combination therapy significantly inhibits levels of BCL-2, MMP-9, VEGF, and TGF-β while inducing p53, p21, and BAX expression. In terms of oncogenic markers, western blotting analysis showed a significant reduction of BCl-2 expression and elevation in caspase3, p53, and p21 proteins as indicators of cell death via apoptosis. The antitumor in vivo effect of the combination therapy showed significant tumor inhibition compared to monotherapy. In conclusion, combination therapy could be a potential promising strategy to treat non-small cell lung carcinoma.

LOXL1-AS1 Contributes to Non-Small Cell Lung Cancer Progression by Regulating miR-3128/RHOXF2 Axis

Purpose

The purpose of this study was to investigate the molecular mechanism of LncRNA LOXL1-AS1 in non-small cell lung cancer (NSCLC).

Methods

Lung cancer cell lines (H1299, A549, H520 and H596) and human normal lung epithelial cell line (BEAS-2B) were used in this study. Gene expression was measured by qRT-PCR (quantitative real-time PCR). The bioinformatics databases (miRDB and TargetScan7) were used to predict target genes. Luciferase assay and pull-down assay were processed for verifying the binding sites. CCK8 assay was used for detecting proliferation, and transwell assay was undertaken for migration and invasion.

Results

LncRNA LOXL1-AS1 was higher expressed in lung cancer tissues and cells. Moreover, LOXL1-AS1 expression was upregulated in tumor tissues with advanced stages and metastasis. After knocking down LOXL1-AS1, proliferation, invasion and migration of H1299 and A549 cells were inhibited. Interestingly, miR-3128 was negatively regulated by LncRNA LOXL1-AS1, which inhibited the expression of RHOXF2. Rescue assay also confirmed that miR-3128 inhibitor and oeRHOXF2 could rescue the effect of down-regulated LOXL1-AS1 on proliferation, invasion and migration progression.

Conclusion

LOXL1-AS1 promotes the progression of NSCLC by regulating miR-3128/RHOXF2 axis, which might be a new potential target for the diagnosis and treatment of NSCLC.

Emodin reverses 5-Fu resistance in human colorectal cancer via downregulation of PI3K/Akt signaling pathway

BACKGROUND

5-Fu resistance is a major obstacle in the treatment of malignant tumors. Therefore, combination therapy is employed to overcome this limitation. Since it was demonstrated that emodin could resensitize breast cancer to 5-Fu treatment, we aimed to investigate if emodin could reverse 5-Fu resistant colorectal cancer (CRC) in the current study.

METHODS

For the aim to explore the effect of emodin on 5-Fu resistant CRC, 5-Fu-resistant cell line (SW480/5-Fu) was established. CCK-8 assay and Ki67 staining were performed to evaluate the effects of emodin in combination with 5-Fu on cell proliferation. Flow cytometry was used to detect the apoptosis of SW480/5-Fu cells. Additionally, the invasion and migration of SW480/5-Fu cells were tested by transwell assay and wound healing, respectively. Western-blot was performed to examine the protein expressions in SW480/5-Fu cells. Moreover, xenograft mice model was established to test the anti-tumor effect of emodin in combination with 5-Fu in vivo.

RESULTS

Emodin notably increased the anti-proliferation effect of 5-Fu in SW480/5-Fu cells. Similarly, the invasion and migration of SW480/5-Fu cells were further inhibited in the presence of emodin. In addition, the combination treatment (emodin plus 5-Fu) induced cell apoptosis via inhibiting Bcl-2 and activating cleaved caspase3 and Bax. Moreover, emodin reduced 5-Fu resistant in CRC via downregulation of PI3K/Akt signaling. Finally, in vivo study indicated that emodin could notably reverse 5-Fu resistance in CRC xenograft.

CONCLUSION

Our research revealed that emodin could reverse 5-Fu resistance in CRC through inactivating PI3K/Akt signaling pathway in vitro and in vivo. Thus, this finding might provide a molecular basis for treating 5-Fu resistant CRC.

Comprehensive Genomic Profiling of Rare Tumors: Routes to Targeted Therapies

Comprehensive Genomic Profiling may be informative for novel treatment strategies and to improve outcomes for patients with rare tumors. This study aims to discover opportunities for use of targeted therapies already approved for routine use in patients with rare tumors. Solid tumors with an incidence lower than 2.5/100,000 per year was defined as rare tumors in China after comprehensive analysis based on epidemiological data and current availability of standardized treatment. Genomic data of rare tumors from the public database cBioPortal were compared with that of the Chinese population for targetable genomic alterations (TGAs). TGAs were defined as mutations of ALK, ATM, BRAF, BRCA1, BRCA2, CDKN2A, EGFR, ERBB2, FGFR1,2,3, KIT, MET, NF1, NTRK1,2,3, PIK3CA, PTEN, RET, and ROS1 with level 1 to 4 of evidence according to the OncoKB knowledge database. Genomic data of 4,901 patients covering 63 subtypes of rare tumor from cBioPortal were used as the western cohort. The Chinese cohort was comprised of next generation sequencing (NGS) data of 1,312 patients from across China covering 67 subtypes. Forty-one subtypes were common between the two cohorts. The accumulative prevalence of TGAs was 20.40% (1000/4901) in cBioPortal cohort, and 53.43% (701/1312) in Chinese cohort (p < 0.001). Among those 41 overlapping subtypes, it was still significantly higher in Chinese cohort compared with cBioPortal cohort (54.1%% vs. 26.1%, p < 0.001). Generally, targetable mutations in BRAF, BRCA2, CDKN2A, EGFR, ERBB2, KIT, MET, NF1, ROS1 were ≥3 times more frequent in Chinese cohort compared with that of the cBioPortal cohort. Cancer of unknown primary tumor type, gastrointestinal stromal tumor, gallbladder cancer, intrahepatic cholangiocarcinoma, and sarcomatoid carcinoma of the lung were the top 5 tumor types with the highest number of TGAs per tumor. The incidence of TGAs in rare tumors was substantial worldwide and was even higher in our Chinese rare tumor population. Comprehensive genomic profiling may offer novel treatment paradigms to address the limited options for patients with rare tumors.

Overcoming multidrug resistance through inhalable siRNA nanoparticles-decorated porous microparticles based on supercritical fluid technology

BACKGROUND

In recent times, the co-delivery therapeutics have garnered enormous interest from researchers in the treatment of cancers with multidrug resistance (MDR) due to their efficient delivery of multiple agents, which result in synergistic effects and capable of overcoming all the obstacles of MDR in cancer. However, an efficient delivery platform is required for the conveyance of diverse agents that can successfully devastate MDR in cancer.

METHODS

Initially, short-interfering RNA-loaded chitosan (siRNA-CS) nanoparticles were synthesized using the ionic gelation method. Further, the siRNA-CS nanoparticles and doxorubicin hydrochloride (DOX) were co-loaded in poly-L-lactide porous microparticles (PLLA PMs) (nano-embedded porous microparticles, [NEPMs]) by the supercritical anti-solvent (SAS) process.

RESULTS AND DISCUSSION

The NEPM formulation exhibited an excellent aerodynamic performance and sustained release of DOX, which displayed higher anticancer efficacy in drug-resistant cells (human small cell lung cancer, H69AR cell line) than those treated with either free DOX and DOX-PLLA PMs due to the siRNA from CS nanoparticles silenced the MDR gene to DOX therapy.

CONCLUSION

This eco-friendly process provides a convenient way to fabricate such innovative NEPMs co-loaded with a chemotherapeutic agent and a gene, which can devastate MDR in cancer through the co-delivery system.

Tubulin Inhibitor-Based Antibody-Drug Conjugates for Cancer Therapy

Antibody-drug conjugates (ADCs) are a class of highly potent biopharmaceutical drugs generated by conjugating cytotoxic drugs with specific monoclonal antibodies through appropriate linkers. Specific antibodies used to guide potent warheads to tumor tissues can effectively reduce undesired side effects of the cytotoxic drugs. An in-depth understanding of antibodies, linkers, conjugation strategies, cytotoxic drugs, and their molecular targets has led to the successful development of several approved ADCs. These ADCs are powerful therapeutics for cancer treatment, enabling wider therapeutic windows, improved pharmacokinetic/pharmacodynamic properties, and enhanced efficacy. Since tubulin inhibitors are one of the most successful cytotoxic drugs in the ADC armamentarium, this review focuses on the progress in tubulin inhibitor-based ADCs, as well as lessons learned from the unsuccessful ADCs containing tubulin inhibitors. This review should be helpful to facilitate future development of new generations of tubulin inhibitor-based ADCs for cancer therapy.

Be Active or Not: the Relative Contribution of Active and Passive Tumor Targeting of Nanomaterials

Malignant tumor (cancer) remains as one of the deadliest diseases throughout the world, despite its overall mortality drops. Nanomaterials (NMs) have been widely studied as diagnostic and/or therapeutic agents for tumors. A feature of NMs, compared to small molecules, is that NMs can be concentrated passively in tumors through enhanced permeability and retention (EPR) effect. In the meantime, NMs can be engineered to target toward tumor specific markers in an active manner, e.g., receptor-mediated targeting. The relative contribution of the EPR effect and the receptor-mediated targeting to NM accumulation in tumor tissues has not been clearly defined yet. Here, we tackle this fundamental issue by reviewing previous studies. First, we summarize the current knowledge on these two tumor targeting strategies of NMs, and on how NMs arrive to tumors from blood circulation. We then demonstrate that contribution of the active and passive effects to total accumulation of NMs in tumors varies with time. Over time, the receptor-mediated targeting contributes more than the EPR effect with a ratio of 3 in the case of urokinase-type plasminogen activator receptor (uPAR)-mediated targeting and human serum albumin (HSA)-mediated EPR effect. Therefore, this review highlights the dynamics of active and passive targeting of NMs on their accumulation at tumor sites, and is valuable for future design of NMs in cancer diagnosis and treatment.

Targeting KRas-dependent tumour growth, circulating tumour cells and metastasis in vivo by clinically significant miR-193a-3p

KRas is mutated in a significant number of human cancers and so there is an urgent therapeutic need to target KRas signalling. To target KRas in lung cancers we used a systems approach of integrating a genome-wide miRNA screen with patient-derived phospho-proteomic signatures of the KRas downstream pathway, and identified miR-193a-3p, which directly targets KRas. Unique aspects of miR-193a-3p biology include two functionally independent target sites in the KRas 3'UTR and clinically significant correlation between miR-193a-3p and KRas expression in patients. Rescue experiments with mutated KRas 3'UTR showed very significantly that the anti-tumour effect of miR-193a-3p is via specific direct targeting of KRas and not due to other targets. Ex vivo and in vivo studies utilizing nanoliposome packaged miR-193a-3p demonstrated significant inhibition of tumour growth, circulating tumour cell viability and decreased metastasis. These studies show the broader applicability of using miR-193a-3p as a therapeutic agent to target KRas-mutant cancer.

Epidermal Growth Factor Signaling towards Proliferation: Modeling and Logic Inference Using Forward and Backward Search

In biological systems, pathways define complex interaction networks where multiple molecular elements are involved in a series of controlled reactions producing responses to specific biomolecular signals. These biosystems are dynamic and there is a need for mathematical and computational methods able to analyze the symbolic elements and the interactions between them and produce adequate readouts of such systems. In this work, we use rewriting logic to analyze the cellular signaling of epidermal growth factor (EGF) and its cell surface receptor (EGFR) in order to induce cellular proliferation. Signaling is initiated by binding the ligand protein EGF to the membrane-bound receptor EGFR so as to trigger a reactions path which have several linked elements through the cell from the membrane till the nucleus. We present two different types of search for analyzing the EGF/proliferation system with the help of Pathway Logic tool, which provides a knowledge-based development environment to carry out the modeling of the signaling. The first one is a standard (forward) search. The second one is a novel approach based on narrowing, which allows us to trace backwards the causes of a given final state. The analysis allows the identification of critical elements that have to be activated to provoke proliferation.

Patient-derived xenografts: a relevant preclinical model for drug development

Identifying appropriate preclinical cancer models remains a major challenge in increasing the efficiency of drug development. A potential strategy to improve patient outcomes could be selecting the ‘right’ treatment in preclinical studies performed in patient-derived xenografts (PDXs) obtained by direct implants of surgically resected tumours in mice. These models maintain morphological similarities and recapitulate molecular profiling of the original tumours, thus representing a useful tool in evaluating anticancer drug response. In this review, we will present the state-of-art use of PDXs as a reliable strategy to predict clinical findings. The main advantages and limitations will also be discussed.

The prevalence of expression of MAGE-A3 and PRAME tumor antigens in East and South East Asian non-small cell lung cancer patients

INTRODUCTION

Treatment of non-small cell lung cancer (NSCLC) is an important and often unmet medical need regardless of the disease stage at the time of first diagnosis. Antigen-specific immunotherapy may be a feasible therapeutic option if tumor associated antigens (TAAs) that can be targeted by the patient's immune system are identified. The study objective (NCT01837511) was to investigate the expression rates of MAGE-A3 and PRAME in tumors from East Asian NSCLC patients, and the associations between TAA expression and clinico-pathologic patient characteristics.

METHODS

Archived formalin-fixed paraffin-embedded tumor tissue specimens were tested for MAGE-A3 and PRAME expression by quantitative reverse transcription polymerase chain reaction. Exploratory analyses of the impact of patient and tumor characteristics on antigen expression were performed by multivariate logistic regression analyses.

RESULTS

A total of 377 specimens were tested and a valid expression result was obtained for 86.5% and 92.6% for MAGE-A3 and PRAME, respectively. Of the specimens with valid test results, 26.4% expressed MAGE-A3, 49.9% PRAME, 20.0% both and 57.5% expressed at least one TAA. The same pattern of associations between antigen expression and patient and tumor characteristics was found for both TAAs: higher rates of antigen-positive tumors were found in squamous cell carcinomas compared to adenocarcinomas, and for smokers compared to non-smokers.

CONCLUSIONS

Expression of MAGE-A3 and PRAME suggests an association with tumor histology and the patient's smoking status. The rates of TAA-positive tumors found in these East and South East Asian NSCLC patients indicate that both antigens may serve as targets for antigen-specific immunotherapies.

Protein-protein interactions between SWCNT/chitosan/EGF and EGF receptor: a model of drug delivery system

Epidermal growth factor (EGF) was used as the targeting ligand to enhance the specificity of a cancer drug delivery system (DDS) via its specific interaction with the EGF receptor (EGFR) that is overexpressed on the surface of some cancer cells. To investigate the intermolecular interaction and binding affinity between the EGF-conjugated DDS and the EGFR, 50 ns molecular dynamics simulations were performed on the complex of tethered EGFR and EGF linked to single-wall carbon nanotube (SWCNT) through a biopolymer chitosan wrapping the tube outer surface (EGFR·EGF-CS-SWCNT-Drug complex), and compared to the EGFR·EGF complex and free EGFR. The binding pattern of the EGF-CS-SWCNT-Drug complex to the EGFR was broadly comparable to that for EGF, but the binding affinity of the EGF-CS-SWCNT-Drug complex was predicted to be somewhat better than that for EGF alone. Additionally, the chitosan chain could prevent undesired interactions of SWCNT at the binding pocket region. Therefore, EGF connected to SWCNT via a chitosan linker is a seemingly good formulation for developing a smart DDS served as part of an alternative cancer therapy.

Bronchial-pulmonary adenocarcinoma subtyping relates with different molecular pathways

Lung cancer is one of the most common cancers in the world with a high mortality rate. We analyzed 45 surgical samples of the adenocarcinoma, 13 with lymph node metastasis. APC, BCL2, chromogranin A, CK 5/6/18 (LP34), CK20, CK7, cyclin D1, EGFR, ERCC1, HER2, Ki67, LRP, MRP, P53, RB and TTF1 expressions were evaluated by immunohistochemistry (IHC). Higher Ki67, APC, ERCC1 expressions and lower TTF1 expression were identified in advanced stages (IIA and IIIA) of adenocarcinomas, which reflect a more aggressive, less differentiated, possibly a non-TRU adenocarcinoma. Acinar, micropapillary and BA/lepidic adenocarcinoma patterns were the most similar patterns and papillary was the most different pattern followed by solid pattern, according to expression of these markers. Different adenocarcinoma patterns are engaged with different molecular pathways for carcinogenesis, based on the differences of expression. Acinar, BA/lepidic and micropapillary showed higher TTF1 expression (type TRU), and papillary and solid patterns revealed less TTF1 expression, exhibiting a non-TRU/bronchial phenotype. Solid pattern revealed lower HER2 and higher EGFR and ERCC1 (this compared to papillary) expression; papillary higher HER2 and lower ERCC1 expressions; micropapillary higher RB expression; and acinar lower ERCC1 and higher EGFR expressions. Ciclin D1 seems to have more importance in acinar and BA/lepidic patterns than in micropapillary. ERCC1 protein expression in micropapillary, solid and BA/lepidic patterns may indicate DNA repair activation. Inhibition of apoptosis could be explained by BCL2 overexpression, present in all adenocarcinoma patterns. MRP-1 and LRP were overexpressed in all patterns, which may have implications for drug resistance. Further studies are needed to interpret these data regarding to therapy response in advanced staged bronchial-pulmonary carcinomas.

Simultaneous blockage of epidermal growth factor receptor and cyclooxygenase-2 in a human xenotransplanted lung cancer model

The effects of erlotinib combined with celecoxib in a lung cancer xenograft model were here explored with a focus on possible mechanisms. A xenotransplanted lung cancer model was established in nude mice using the human lung cancer cell A549 cell line and animals demonstrating tumour growth were randomly divided into four groups: control, erlotinib, celecoxib and combined (erotinib and celecoxib). The tumor major axis and short diameter were measured twice a week and after 40 days tissues were collected for immunohistochemical analyses of Bcl-2 and Bax positive cells and Western-blotting analyses for the epidermal growth factor recepto (EGFR), P-EGFR, and cyclooxygenase-2 (COX-2). Tumor size in the combined group was smaller than in the others (p<0.01) and the percentage of Bcl-2 positive cells was fewer in most cases (p<0.01), while that of Bax positive cells was greater than in the erlotinib and celecoxib groups (P>0.05). Western blotting showed decreased expression of P-EGFR and COX-2 with both erlotinib and celecoxib treatments, but most pronouncedly in the combined group (P<0.05). Simultaneous blockage of the EGFR and COX-2 signal pathways exerted stronger growth effects in our human xenotransplanted lung cancer model than inhibition of either pathway alone. The anti-tumor effects were accompanied by synergetic inhibition of tumor cell apoptosis, activation of p-EGFR and expression of COX-2.

Immunotherapy for Lung Cancer: Has it Finally Arrived?

The possible link between infection/inflammation/immune activation and a cancer patient’s outcome from both a causative and outcome point of view has long been postulated. Substantial progress in the understanding of tumor-associated antigens/epitopes, immune cellular subpopulations, cytokine pathways/expression, the tumor microenvironment, and the balance between tumor-immune suppression and stimulation have been made over the past decade. This knowledge has heralded a new era of tumor immunotherapy utilizing vaccines, immune checkpoint inhibition, and oncolytic viruses. Despite significant progress in the molecular era now with targeted therapeutics such as EGFR tyrosine kinase inhibitors and ALK fusion protein inhibitors that have significantly improved the outcome of these specific lung cancer subpopulations, the overall 5 year survival for all non-small cell lung cancer (NSCLC) is still <20%. Unlike malignancies such as malignant melanoma, renal cell carcinoma, and neuroblastoma given their documented spontaneous remission rates lung cancer historically has been felt to be resistant to immune approaches likely related to an immunosuppressive tumor microenvironment and/or lack of immune recognition. Defining responding populations, understanding the mechanism(s) underlying durable immune responses, and the role of chemotherapy, radiation, oncolytic viruses, and other tumor disrupting agents in augmenting immune responses have led to improved optimization of immune therapeutic strategies. The purpose of this review is to focus on the recent advances in lung immunotherapy with an emphasis on recent clinical trials in the last 5 years in NSCLC.

WITHDRAWN: Bronchial-pulmonary adenocarcinoma subtyping relates with different molecular pathways

This article has been withdrawn for editorial reasons because the journal will be published only in English. In order to avoid duplicated records, this article can be found at http://dx.doi.org/10.1016/j.rppnen.2014.05.006. The Publisher apologizes for any inconvenience this may cause. The full Elsevier Policy on Article Withdrawal can be found at http://www.elsevier.com/locate/withdrawalpolicy.

Novel agents and strategies for overcoming EGFR TKIs resistance

Since the recognition of epidermal growth factor receptor (EGFR) as a therapeutic target, EGFR tyrosine kinase inhibitors (TKIs) have been used in lung cancer patients with EGFR mutations, which has been a major breakthrough for lung cancer treatment.. The progression-free survival (PFS) of patients with EGFR mutations treated with EGFR TKIs is significantly prolonged compared with that of patients who underwent standard chemotherapy. However, all patients who initially respond to EGFR TKIs eventually develop acquired resistance (AR). Many small molecule agents and monoclonal antibodies (McAb) targeting signaling pathways are potential therapeutic regimens for overcoming resistance, and various therapeutic strategies are used in clinical practice. Here we review the novel agents and therapeutic strategies for overcoming AR to EGFR TKIs.

Establishment of patient-derived non-small cell lung cancer xenograft models with genetic aberrations within EGFR, KRAS and FGFR1: useful tools for preclinical studies of targeted therapies

BACKGROUND

Patient-derived tumor xenograft models have been established and increasingly used for preclinical studies of targeted therapies in recent years. However, patient-derived non-small cell lung cancer (NSCLC) xenograft mouse models are relatively few in number and are limited in their degree of genetic characterization and validation. In this study, we aimed to establish a variety of patient-derived NSCLC models and characterize these for common genetic aberrations to provide more informative models for preclinical drug efficacy testing.

METHODS

NSCLC tissues from thirty-one patients were collected and implanted into immunodeficient mice. Established xenograft models were characterized for common genetic aberrations, including detection of gene mutations within EGFR and KRAS, and genetic amplification of FGFR1 and cMET. Finally, gefitinib anti-tumor efficacy was tested in these patient-derived NSCLC xenograft models.

RESULTS

Ten passable patient-derived NSCLC xenograft models were established by implantation of NSCLC specimens of thirty-one patients into immunodeficient mice. Genetic aberrations were detected in six of the models, including one model with an EGFR activating mutation (Exon19 Del), one model with KRAS mutation, one model with both KRAS mutation and cMET gene amplification, and three models with FGFR1 amplification. Anti-tumor efficacy studies using gefitinib demonstrated that the EGFR activating mutation model had superior sensitivity and that the KRAS mutation models were resistant to gefitinib. The range of gefitinib responses in the patient-derived NSCLC xenograft models were consistent with the results reported from clinical trials. Furthermore, we observed that patient-derived NSCLC models with FGFR1 gene amplification were insensitive to gefitinib treatment.

CONCLUSIONS

Ten patient-derived NSCLC xenograft models were established containing a variety of genetic aberrations including EGFR activating mutation, KRAS mutation, and FGFR1 and cMET amplification. Gefitinib anti-tumor efficacy in these patient-derived NSCLC xenografts containing EGFR and KRAS mutation was consistent with the reported results from previous clinical trials. Thus, data from our panel of patient-derived NSCLC xenograft models confirms the utility of these models in furthering our understanding of this disease and aiding the development of personalized therapies for NSCLC patients.

Adjuvant MAGE-A3 immunotherapy in resected non-small-cell lung cancer: phase II randomized study results

PURPOSE

The MAGE-A3 protein is expressed in approximately 35% of patients with resectable non-small-cell lung cancer (NSCLC). Several immunization approaches against the MAGE-A3 antigen have shown few, but often long-lasting, clinical responses in patients with metastatic melanoma.

PATIENTS AND METHODS

A double-blind, randomized, placebo-controlled phase II study was performed assessing clinical activity, immunologic response, and safety following immunization with recombinant MAGE-A3 protein combined with an immunostimulant (13 doses over 27 months) in completely resected MAGE-A3-positive stage IB to II NSCLC. The primary end point was disease-free interval (DFI).

RESULTS

Patients were randomly assigned to either MAGE-A3 immunotherapeutic (n = 122) or placebo (n = 60). After a median postresection period of 44 months, recurrence was observed in 35% of patients in the MAGE-A3 arm and 43% in the placebo arm. No statistically significant improvement in DFI (hazard ratio [HR], 0.75, 95% CI, 0.46 to 1.23; two-sided P = .254), disease-free survival (DFS; HR, 0.76; 95% CI, 0.48 to 1.21; P = .248), or overall survival (HR, 0.81; 95% CI, 0.47 to 1.40; P = .454) was observed. Corresponding analysis after a median of 70 months of follow-up revealed a similar trend for DFI and DFS. All patients receiving the active treatment showed a humoral immune response to the MAGE-A3 antigen, although no correlation was observed with outcome. No significant toxicity was observed.

CONCLUSION

In this early development study with a limited number of patients, postoperative MAGE-A3 immunization proved to be feasible with minimal toxicity. These results are being investigated further in a large phase III study.

Nanostructured lipid carriers as multifunctional nanomedicine platform for pulmonary co-delivery of anticancer drugs and siRNA

We developed, synthesized, and tested a multifunctional nanostructured lipid nanocarrier-based system (NLCS) for efficient delivery of an anticancer drug and siRNA directly into the lungs by inhalation. The system contains: (1) nanostructured lipid carriers (NLC); (2) anticancer drug (doxorubicin or paclitaxel); (3) siRNA targeted to MRP1 mRNA as a suppressor of pump drug resistance; (4) siRNA targeted to BCL2 mRNA as a suppressor of nonpump cellular resistance and (5) a modified synthetic analog of luteinizing hormone-releasing hormone (LHRH) as a targeting moiety specific to the receptors that are overexpressed in the plasma membrane of lung cancer cells. The NLCS was tested in vitro using human lung cancer cells and in vivo utilizing mouse orthotopic model of human lung cancer. After inhalation, the proposed NLCS effectively delivered its payload into lung cancer cells leaving healthy lung tissues intact and also significantly decreasing the exposure of healthy organs when compared with intravenous injection. The NLCS showed enhanced antitumor activity when compared with intravenous treatment. The data obtained demonstrated high efficiency of proposed NLCS for tumor-targeted local delivery by inhalation of anticancer drugs and mixture of siRNAs specifically to lung cancer cells and, as a result, efficient suppression of tumor growth and prevention of adverse side effects on healthy organs.

Is there still a role for mitomycin-based combination chemotherapy in treating patients with nonsmall cell lung cancer? A single institution experience

Background:

Mitomycin and irinotecan are widely used in the treatment of colorectal cancer, furthermore both of these drugs are active agents against nonsmall cell lung cancer and their combination has shown synergism in preclinical studies. The aim of the study was to evaluate the efficacy and safety of mitomycin- and irinotecan-based chemotherapy combination in patients with advanced nonsmall cell lung cancer progressing after previous antineoplastic therapies.

Methods:

Thirty-one consecutive patients suffering from nonsmall cell lung cancer, who underwent mitomycin- plus irinotecan-based chemotherapy as salvage treatment after failure of at least two previous systemic treatments, were retrospectively identified in our database. Between September 2003 and March 2011, 31 patients with histologically proven stage IIIB or IV nonsmall cell lung cancer, received mitomycin 5 mg/m2 on day 1 followed by irinotecan 150 mg/m2 on day 2. Cycles were repeated at 2-week interval.

Results:

A total of 164 cycles of treatment were given with a median of five per patient (range 1–10). The objective responses included partial response in 6 patients (19.3%), stable disease in 4 (13%), and progressive disease in 21 (67.7%). Median time to disease progression was 4 months, and median survival was 9+ months. Twelve patients (38%) reached 1-year survival. Grade 3–4 toxicities occurred in seven patients (22.5%), mainly myelosuppression (neutropenia, anemia, and thrombocytopenia), mucositis, and diarrhea. No treatment-related death was recorded.

Conclusion:

The mitomycin- and irinotecan-based combination chemotherapy seems to be tolerated and active in this subset of heavily pretreated patients with advanced nonsmall cell lung cancer. However, evaluation or recruitment of a larger number of patients would be needed to provide more adequate data on safety and activity of the described combination.

CD22 antigen is broadly expressed on lung cancer cells and is a target for antibody-based therapy

Most patients with lung cancer still die from their disease, necessitating additional options to improve treatment. Here, we provide evidence for targeting CD22, a cell adhesion protein known to influence B-cell survival that we found is also widely expressed in lung cancer cells. In characterizing the antitumor activity of an established anti-CD22 monoclonal antibody (mAb), HB22.7, we showed CD22 expression by multiple approaches in various lung cancer subtypes, including 7 of 8 cell lines and a panel of primary patient specimens. HB22.7 displayed in vitro and in vivo cytotoxicity against CD22-positive human lung cancer cells and tumor xenografts. In a model of metastatic lung cancer, HB22.7 inhibited the development of pulmonary metastasis and extended overall survival. The finding that CD22 is expressed on lung cancer cells is significant in revealing a heretofore unknown mechanism of tumorigenesis and metastasis. Our work suggests that anti-CD22 mAbs may be useful for targeted therapy of lung cancer, a malignancy that has few tumor-specific targets.

Pharmacokinetics and pharmacodynamics of anti-BR3 monoclonal antibody in mice

PURPOSE

To characterize the pharmacokinetic (PK) and pharmacodynamic (PD) properties of a monoclonal antibody directed against the B-cell activating factor (BAFF) receptor 3 (BR3), following intravenous (IV) and subcutaneous (SC) administration in mice.

METHODS

Single IV doses of 0.2, 2.0 and 20 mg/kg and a single SC injection of 20 mg/kg of anti-BR3 antibody was administered to mice. Serum drug and BAFF concentrations and splenic B-cell concentrations were measured at various time points. Pooled PK profiles were described by a two-compartmental model with time-dependent nonlinear elimination, and BAFF profiles were defined by an indirect response model. Fractional receptor occupancy served as the driving function for a competitive reversible antagonism model to characterize B-cell dynamics.

RESULTS

Noncompartmental analysis revealed a decrease in drug clearance (31.3 to 7.93 mL/day/kg) with increasing IV doses. The SC dose exhibited slow absorption (T(max) = 2 days) and complete bioavailability. All doses resulted in a dose-dependent increase in BAFF concentrations and decrease in B-cell counts. The proposed model reasonably captured complex PK/PD profiles of anti-BR3 antibody after IV and SC administration.

CONCLUSIONS

A mechanistic model was developed that describes the reversible competition between anti-BR3 antibody and BAFF for BR3 receptors and its influence on B-cell pharmacodynamics.

Phosphosignature predicts dasatinib response in non-small cell lung cancer

Targeted drugs are less toxic than traditional chemotherapeutic therapies; however, the proportion of patients that benefit from these drugs is often smaller. A marker that confidently predicts patient response to a specific therapy would allow an individual therapy selection most likely to benefit the patient. Here, we used quantitative mass spectrometry to globally profile the basal phosphoproteome of a panel of non-small cell lung cancer cell lines. The effect of the kinase inhibitor dasatinib on cellular growth was tested against the same panel. From the phosphoproteome profiles, we identified 58 phosphorylation sites, which consistently differ between sensitive and resistant cell lines. Many of the corresponding proteins are involved in cell adhesion and cytoskeleton organization. We showed that a signature of only 12 phosphorylation sites is sufficient to accurately predict dasatinib sensitivity. Four of the phosphorylation sites belong to integrin β4, a protein that mediates cell-matrix or cell-cell adhesion. The signature was validated in cross-validation and label switch experiments and in six independently profiled breast cancer cell lines. The study supports that the phosphorylation of integrin β4, as well as eight further proteins comprising the signature, are candidate biomarkers for predicting response to dasatinib in solid tumors. Furthermore, our results show that identifying predictive phosphorylation signatures from global, quantitative phosphoproteomic data is possible and can open a new path to discovering molecular markers for response prediction.

Adjuvant immunotherapy for non-small cell lung cancer

Non-small cell lung cancer (NSCLC) is the biggest cancer killer in the United States and worldwide. In 2011, there are estimated to be 221,130 new cases of lung cancer in the United States. Over a million people will die of lung cancer worldwide this year alone. When possible, surgery to remove the tumor is the best treatment strategy for patients with NSCLC. However, even with adjuvant (postoperative) chemotherapy and radiation, more than 40% of patients will develop recurrences locally or systemically and ultimately succumb to their disease. Thus, there is an urgent need for developing superior approaches to treat patients who undergo surgery for NSCLC to eliminate residual disease that is likely responsible for these recurrences. Our group and others have been interested in using immunotherapy to augment the efficacy of current treatment strategies. Immunotherapy is very effective against minimal disease burden and small deposits of tumor cells that are accessible by the circulating immune cells. Therefore, this strategy may be ideally suited as an adjunct to surgery to seek and destroy microscopic tumor deposits that remain after surgery. This review describes the mechanistic underpinnings of immunotherapy and how it is currently being used to target residual disease and prevent postoperative recurrences after pulmonary resection in NSCLC.

Evolution and future of skull base surgery: the paradigm of skull base meningiomas

BACKGROUND

Skull base meningiomas represent the paradigm for the evolution of skull base surgery within the past 50 years into a distinct neurosurgical subspecialty.

METHODS

From 2005 to 2011, 117 patients with cranial base meningiomas underwent surgical resection. Extent of resection, histologic grade, complications, functional status, and recurrence-free and overall survival data are presented.

RESULTS

The summary rate of gross total resection was 53.0%. The surgical complication and mortality rates were 17.9% and 0.9%, respectively. Five-year recurrence-free survival was 88.0% for grade I meningiomas. A total of 90.3% of patients had a Karnofsky performance score ≥ 80 at last follow-up.

CONCLUSIONS

A large contemporary series of skull base meningiomas is presented. In addition, the evolution of surgical approaches to skull base meningiomas is reviewed, together with the current issues regarding radiation therapy, management of cavernous sinus tumor, oncologic management of atypical and malignant subtypes, molecular genetics, and future therapeutic options.

Randomized, Double-Blind, Placebo-Controlled Phase II Study of Single-Agent Oral Talactoferrin in Patients With Locally Advanced or Metastatic Non–Small-Cell Lung Cancer That Progressed After Chemotherapy

Purpose

To investigate the activity and safety of oral talactoferrin (TLF) in patients with stages IIIB to IV non–small-cell lung cancer (NSCLC) for whom one or two prior lines of systemic anticancer therapy had failed.

Patients and Methods

Patients (n = 100) were randomly assigned to receive either oral TLF (1.5 g in 15 mL phosphate-based buffer) or placebo (15 mL phosphate-based buffer) twice per day in addition to supportive care. Oral TLF or placebo was administered for a maximum of three 14-week cycles with dosing for 12 consecutive weeks followed by 2 weeks off. The primary objective was overall survival (OS) in the intent-to-treat (ITT) patient population. Secondary objectives included progression-free survival (PFS), disease control rate (DCR), and safety.

Results

TLF was associated with improvement in OS in the ITT patient population, meeting the protocol-specified level of significance of a one-tailed P = .05. Compared with the placebo group, median OS increased by 65% in the TLF group (3.7 to 6.1 months; hazard ratio, 0.68; 90% CI, 0.47 to 0.98; P = .04 with one-tailed log-rank test). Supportive trends were also observed for PFS and DCR. TLF was well tolerated and, generally, there were fewer adverse events (AEs) and grade ≥ 3 AEs reported in the TLF arm. AEs were consistent with those expected in late-stage NSCLC.

Conclusion

TLF demonstrated an apparent improvement in OS in patients with stages IIIB to IV NSCLC for whom one or two prior lines of systemic anticancer therapy had failed and was well tolerated. These results should be confirmed in a global phase III trial.

Rapid and efficient detection of EGFR mutations in problematic cytologic specimens by high-resolution melting analysis

BACKGROUND AND OBJECTIVE

Chemotherapy for advanced non-small-cell lung cancer (NSCLC) remains marginally effective, with a 5-year overall survival rate of approximately 5%. Recently, the epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor gefitinib was approved in Slovakia for the treatment of metastatic NSCLC. Gefitinib is a selective EGFR inhibitor that binds to the adenosine triphosphate binding pocket of the kinase domain and blocks downstream signaling pathways. Mutations of the EGFR gene, particularly an in-frame 15 bp deletion (delE746_A750) in exon 19 and the L858R mutation in exon 21, correlate with enhanced clinical responsiveness to EGFR tyrosine kinase inhibitors. However, the detection of these mutations and thereby prediction of the therapy outcome is sometimes unreliable due to the low sensitivity of direct sequencing if the proportion of tumor cells in the tissue is less than 25%. Therefore we decided to test the applicability of other methods, particularly high-resolution melting analysis (HRMA), for detection of these mutations in clinical samples.

METHODS

We analyzed 53 archival cytologic specimens for the presence of EGFR mutations, using the HRMA method. Results were verified by direct sequencing. For samples containing less than 25% tumor cells, we used mutant-enriched PCR before sequencing. We also performed a titration assay to establish the lower limit of the proportion of tumor cells for detection of EGFR mutations.

RESULTS

EGFR mutations were detected in 13 cases (24%). In-frame deletions in exon 19 were detected in eight cases (15%) and the L858R mutation in exon 21 was detected in five cases (9%). The positive results of the HRMA were confirmed by direct sequencing only in five of 13 cases. In the remaining eight positive samples, HRMA results were confirmed by sequencing analysis after mutant-DNA enrichment. The titration assay established that the lower limit for detection of EGFR mutations by HMRA was 1% tumor cells in the clinical sample.

CONCLUSION

Our results indicated that HRMA in combination with mutant-enriched PCR represents a sensitive method for detection of EGFR mutations from cytologic specimens. When properly executed, this protocol allows identification of EGFR mutations in specimens containing a minimal percentage of tumor cells.

Mapping EGFR1 mutations in patients with lung adenocarcinoma

INTRODUCTION

Unselected lung cancer patients seem unable to gain in terms of survival from treatment with epidermal growth factor receptor (EGFR) inhibitors. Screening for specific molecular targets involves detection of EGFR1 mutations. The aim of our study was to develop a simple set of tests to detect mutations at the tyrosine kinase domain of the EGFR1 gene while avoiding expensive DNA sequencing to select patients eligible for treatment.

METHODS

DNA samples from 85 adenocarcinoma patients were analyzed. The cohort consisted of 65 female (40 nonsmokers and 25 smokers) and 20 male patients [15 smokers and 5 diagnosed with bronchioloalveolar carcinomas (BAC)]. Different restriction enzymes were identified that recognize mutations at the EGFR1's tyrosine kinase domain. Biocomputing and polymerase chain reaction were used to develop molecular screening tools.

RESULTS

Eight mutations were found in 7 patients, of which 5 were female nonsmokers (14.3%), 1 was a male nonsmoker, and 1 a male smoker. Among the mutations that were discovered, 5 (71%) were found at exon 19 and 3 (29%) at exon 20. At exon 19, 4 were deletions found in nonsmoker women, whereas the fifth was a deletion-insertion found in a nonsmoker male patient with BAC. At exon 20, 3 mutations were identified in 2 patients: a duplication (in a nonsmoker woman) and 2 substitutions (in a smoker male with BAC). No mutations were found at exons 18 and 21. Gene copy number was increased in 6 patients (4 female and 2 male) with the highest being found in a smoking female patient diagnosed with BAC.

CONCLUSION

Mapping of EGFR1 mutations by alternative methods should be used in the screening of patients with non-small cell lung cancer who are candidates for EGFR inhibitor treatment. Patients with an increased EGFR1 copy number could benefit from the monoclonal antibody therapy.

Dr. PIAS: an integrative system for assessing the druggability of protein-protein interactions

Background

The amount of data on protein-protein interactions (PPIs) available in public databases and in the literature has rapidly expanded in recent years. PPI data can provide useful information for researchers in pharmacology and medicine as well as those in interactome studies. There is urgent need for a novel methodology or software allowing the efficient utilization of PPI data in pharmacology and medicine.

Results

To address this need, we have developed the 'Druggable Protein-protein Interaction Assessment System' (Dr. PIAS). Dr. PIAS has a meta-database that stores various types of information (tertiary structures, drugs/chemicals, and biological functions associated with PPIs) retrieved from public sources. By integrating this information, Dr. PIAS assesses whether a PPI is druggable as a target for small chemical ligands by using a supervised machine-learning method, support vector machine (SVM). Dr. PIAS holds not only known druggable PPIs but also all PPIs of human, mouse, rat, and human immunodeficiency virus (HIV) proteins identified to date.

Conclusions

The design concept of Dr. PIAS is distinct from other published PPI databases in that it focuses on selecting the PPIs most likely to make good drug targets, rather than merely collecting PPI data.

Molecular mechanism of the schedule-dependent synergistic interaction in EGFR-mutant non-small cell lung cancer cell lines treated with paclitaxel and gefitinib

Background

Chemotherapy combined concurrently with TKIs produced a negative interaction and failed to improve survival when compared with chemotherapy or TKIs alone in the treatment of non-small cell lung cancer (NSCLC). The present study investigated the sequence-dependent interaction between paclitaxel and gefitinib and clarified the underlying mechanism.

Methods

The effects on cell proliferation, EGFR signaling pathway, and TGFα expression were evaluated in a panel of human NSCLC cell lines harboring EGFR mutations with three different combination sequences: sequential treatment with paclitaxel followed by gefitinib (T→G), sequential treatment with gefitinib followed by paclitaxel (G→T), or concomitant treatment (T + G).

Results

The sequence-dependent anti-proliferative effects differed between EGFR-TKI-sensitive and -resistant cell lines carrying EGFR mutations. A synergistic anti-proliferative activity was obtained with paclitaxel treatment followed by gefitinib in all cell lines, with mean CI values of 0.63 in Hcc827, 0.54 in PC-9, 0.81 in PC-9/GR, and 0.77 in H1650 cells for the T→G sequence. The mean CI values for the G→T sequence were 1.29 in Hcc827, 1.16 in PC-9, 1.52 in PC-9/GR, and 1.5 in H1650 cells. The mean CI values for T+G concomitant treatment were 0.88 in Hcc827, 0.91 in PC-9, 1.05 in PC-9/GR, and 1.18 in H1650 cells. Paclitaxel produced a dose-dependent increase in EGFR phosphorylation. Paclitaxel significantly increased EGFR phosphorylation compared with that in untreated controls (mean differences: +50% in Hcc827, + 56% in PC-9, + 39% in PC-9/GR, and + 69% in H1650 cells; p < 0.05). The T→G sequence produced significantly greater inhibition of EGFR phosphorylation compared with the opposite sequence (mean differences: -58% in Hcc827, -38% in PC-9, -35% in PC-9/GR, and -30% in H1650 cells; p < 0.05). Addition of a neutralizing anti-TGFα antibody abolished paclitaxel-induced activation of the EGFR pathway in PC-9 and H1650 cells. Sequence-dependent TGFα expression and release are responsible for the sequence-dependent EGFR pathway modulation.

Conclusion

The data suggest that the sequence of paclitaxel followed by gefitinib is an appropriate treatment combination for NSCLC cell lines harboring EGFR mutations. Our results provide molecular evidence to support clinical treatment strategies for patients with lung cancer.

A phase II, randomized, multicenter study to assess the efficacy, safety, and tolerability of zibotentan (ZD4054) in combination with pemetrexed in patients with advanced non-small cell lung cancer

PURPOSE

This study evaluated overall survival (OS) of patients with advanced non-squamous NSCLC following treatment with the specific endothelin A receptor antagonist, zibotentan in combination with pemetrexed compared with pemetrexed monotherapy.

METHODS

In this double-blinded, placebo-controlled study, patients with advanced NSCLC with non-squamous histology who had failed first-line platinum-based chemotherapy were randomized to receive either once-daily zibotentan 10 mg in combination with 3-weekly pemetrexed 500 mg/m(2) or placebo plus 3-weekly pemetrexed 500 mg/m(2). OS was calculated as the interval from date of randomization to date of death from any cause. Safety and tolerability were evaluated by recording the incidence of adverse events (AE) according to Common Toxicity Criteria for AE (CTCAE).

RESULTS

Sixty-six patients were randomized and completed the study (zibotentan plus pemetrexed, n = 30; placebo plus pemetrexed, n = 36). At the data cutoff, a total of 44 deaths had occurred, 20 and 24 in the zibotentan and placebo groups, respectively. No significant difference in OS was observed between the zibotentan and placebo treatment groups (HR, 1.13; 80% CI 0.77, 1.67; P = 0.69). The majority of AE were of CTCAE grade 1 or 2, and the most commonly reported AE in both treatment groups was anemia (23 and 25% of patients in the zibotentan and placebo groups, respectively).

CONCLUSIONS

There was no survival signal in patients with NSCLC following treatment with zibotentan in combination with pemetrexed. No new issues related to safety for either zibotentan or pemetrexed were identified.

Erlotinib resistance is altered after gemcitabine chemotherapy for recurrent non-small-cell lung cancer

We report the case of a male Mongolian lifelong non-smoker with recurrent non-small-cell lung cancer (NSCLC) who developed resistance to the epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor erlotinib after initially responding to this agent but then subsequently had another response to a second course of erlotinib treatment after intervening gemcitabine chemotherapy. Sixteen months after the patient received chemoradiotherapy with gemcitabine/cisplatin plus radiotherapy, his recurrent mediastinal metastases were found to have progressed. Treatment with erlotinib was followed by an initial, partial response but evidence of progression was again observed 6 months later. The patient was then treated with gemcitabine chemotherapy, which resulted in a reduction in tumour volume. One month later, progression of mediastinal metastases was again observed and the patient received a second course of erlotinib. Another partial response occurred and the patient's disease remained stable at the 9-month follow-up visit (and with no reported symptom progression at an 11-month telephone follow-up). Genetic examination of tumour tissue collected at the time of the original diagnosis and during the second course of erlotinib therapy revealed activating exon 19 mutation in the EGFR gene. This case suggests that resistance to erlotinib may change following chemotherapy and that repeat erlotinib therapy may be worth considering after chemotherapy in NSCLC patients who initially respond positively to erlotinib treatment but subsequently experience recurrence of disease.

Erlotinib resistance is altered after gemcitabine chemotherapy for recurrent non-small-cell lung cancer

We report the case of a male Mongolian lifelong non-smoker with recurrent non-small-cell lung cancer (NSCLC) who developed resistance to the epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor erlotinib after initially responding to this agent but then subsequently had another response to a second course of erlotinib treatment after intervening gemcitabine chemotherapy. Sixteen months after the patient received chemoradiotherapy with gemcitabine/cisplatin plus radiotherapy, his recurrent mediastinal metastases were found to have progressed. Treatment with erlotinib was followed by an initial, partial response but evidence of progression was again observed 6 months later. The patient was then treated with gemcitabine chemotherapy, which resulted in a reduction in tumour volume. One month later, progression of mediastinal metastases was again observed and the patient received a second course of erlotinib. Another partial response occurred and the patient's disease remained stable at the 9-month follow-up visit (and with no reported symptom progression at an 11-month telephone follow-up). Genetic examination of tumour tissue collected at the time of the original diagnosis and during the second course of erlotinib therapy revealed activating exon 19 mutation in the EGFR gene. This case suggests that resistance to erlotinib may change following chemotherapy and that repeat erlotinib therapy may be worth considering after chemotherapy in NSCLC patients who initially respond positively to erlotinib treatment but subsequently experience recurrence of disease.

Clinical relevance of KRAS in human cancers

The KRAS gene (Ki-ras2 Kirsten rat sarcoma viral oncogene homolog) is an oncogene that encodes a small GTPase transductor protein called KRAS. KRAS is involved in the regulation of cell division as a result of its ability to relay external signals to the cell nucleus. Activating mutations in the KRAS gene impair the ability of the KRAS protein to switch between active and inactive states, leading to cell transformation and increased resistance to chemotherapy and biological therapies targeting epidermal growth factor receptors. This review highlights some of the features of the KRAS gene and the KRAS protein and summarizes current knowledge of the mechanism of KRAS gene regulation. It also underlines the importance of activating mutations in the KRAS gene in relation to carcinogenesis and their importance as diagnostic biomarkers, providing clues regarding human cancer patients' prognosis and indicating potential therapeutic approaches.

CyberKnife radiosurgery for inoperable stage IA non-small cell lung cancer: 18F-fluorodeoxyglucose positron emission tomography/computed tomography serial tumor response assessment

Objective

To report serial 18F-fluorodeoxyglucose (¹⁸F-FDG) positron emission tomography (PET)/computed tomography (CT) tumor response following CyberKnife radiosurgery for stage IA non-small cell lung cancer (NSCLC).

Methods

Patients with biopsy-proven inoperable stage IA NSCLC were enrolled into this IRB-approved study. Targeting was based on 3-5 gold fiducial markers implanted in or near tumors. Gross tumor volumes (GTVs) were contoured using lung windows; margins were expanded by 5 mm to establish the planning treatment volumes (PTVs). Doses ranged from 42-60 Gy in 3 equal fractions. ¹⁸F-FDG PET/CT was performed prior to and at 3-6-month, 9-15 months and 18-24 months following treatment. The tumor maximum standardized uptake value (SUV_max) was recorded for each time point.

Results

Twenty patients with an average maximum tumor diameter of 2.2 cm were treated over a 3-year period. A mean dose of 51 Gy was delivered to the PTV in 3 to 11 days (mean, 7 days). The 30-Gy isodose contour extended an average of 2 cm from the GTV. At a median follow-up of 43 months, the 2-year Kaplan-Meier overall survival estimate was 90% and the local control estimate was 95%. Mean tumor SUV_max before treatment was 6.2 (range, 2.0 to 10.7). During early follow-up the mean tumor SUV_max remained at 2.3 (range, 1.0 to 5.7), despite transient elevations in individual tumor SUV_max levels attributed to peritumoral radiation-induced pneumonitis visible on CT imaging. At 18-24 months the mean tumor SUV_max for controlled tumors was 2.0, with

a narrow range of values (range, 1.5 to 2.8). A single local failure was confirmed at 24 months in a patient with an elevated tumor SUV_max of 8.4.

Conclusion

Local control and survival following CyberKnife radiosurgery for stage IA NSCLC is exceptional. Early transient increases in tumor SUV_max are likely related to radiation-induced pneumonitis. Tumor SUV_maxvalues return to background levels at 18-24 months, enhancing ¹⁸F-FDG PET/CT detection of local failure. The value of ¹⁸F-FDG PET/CT imaging for surveillance following lung SBRT deserves further study.

Novel histone deacetylase inhibitors in clinical trials as anti-cancer agents

Histone deacetylases (HDACs) can regulate expression of tumor suppressor genes and activities of transcriptional factors involved in both cancer initiation and progression through alteration of either DNA or the structural components of chromatin. Recently, the role of gene repression through modulation such as acetylation in cancer patients has been clinically validated with several inhibitors of HDACs. One of the HDAC inhibitors, vorinostat, has been approved by FDA for treating cutaneous T-cell lymphoma (CTCL) for patients with progressive, persistent, or recurrent disease on or following two systemic therapies. Other inhibitors, for example, FK228, PXD101, PCI-24781, ITF2357, MGCD0103, MS-275, valproic acid and LBH589 have also demonstrated therapeutic potential as monotherapy or combination with other anti-tumor drugs in CTCL and other malignancies. At least 80 clinical trials are underway, testing more than eleven different HDAC inhibitory agents including both hematological and solid malignancies. This review focuses on recent development in clinical trials testing HDAC inhibitors as anti-tumor agents.

Immunotherapy in the landscape of new targeted treatments for non-small cell lung cancer

Non-small cell lung cancer (NSCLC) is the leading cause of cancer-related death worldwide. Active immunotherapies and molecules targeting tyrosine kinase receptors both offer new avenues for the treatment of NSCLC. Furthermore, their combinations or their administration along with standard treatments enlarges the potential for clinical benefit. Moreover, the discovery of biomarkers predicting the response to these new therapies should allow a better selection of patients susceptible to optimally benefit from these treatments. In this paper, we review the most promising active immunotherapies, antibodies and small molecules in the context of NSCLC management, focusing on compounds in phase III clinical development.

Mirk/Dyrk1B, a novel therapeutic target, mediates cell survival in non-small cell lung cancer cells

Minibrain-related kinase (Mirk) is a member of the dual specificity tyrosine-phosphorylation-regulated kinase (Dyrk)/minibrain family of dual-specificity protein kinases and is identical to Dyrk1B. Mirk/Dyrk1B is a serine/threonine kinase that has been found to be upregulated in solid tumors and mediates cell survival in colon cancer, pancreatic ductal adenocarcinoma and rhabdomyosarcomas. There is little known about Mirk in lung cancer. In the present study, we showed that Mirk protein was widely overexpressed in 13 of 19 NSCLC cell lines. Mirk immunoprecipitation coupled with anti-phosphotyrosine western blotting confirmed tyrosine phosphorylation of Mirk in NSCLC cells. Mirk knockdown by small interfering RNA induced cell apoptosis concomitant with upregulation of Bak, a Bcl-2 family member, and downregulation of signal transducers and activators of transcription 3 (STAT3) tyrosine phosphorylation. Mirk knockdown led to decreased cell colony formation in vitro as well as delayed tumor growth in an orthotopic mouse model and sensitized cells to cisplatin-induced apoptosis. Using automated quantitative determination of the Mirk protein in tumor specimens of patients with early-stage lung cancer, overexpression of Mirk was found in nearly 90% of tumor specimens in both the cytoplasm and nucleus. These results suggest that Mirk is overexpressed in lung cancer, acts as a survival factor in lung cancer cells and may be a novel therapeutic target.