Molecular Pathogenesis Of Lung Cancer Research Articles

Abstract 3643: Molecular pathogenesis of lung cancer associated with interstitial pneumonia

Abstract Background: Interstitial pneumonia (IP) is known to be associated with a high risk of developing lung cancer. While common mechanisms have been reported to be involved in the pathogenesis of IP and lung cancer, including genetic and epigenomic alterations or specific signaling pathway activations, many of the molecular mechanisms of lung cancer development in IP lesions remain unknown. Methods: To clarify the detailed mechanisms of the pathogenesis of lung cancer associated with IP, we performed spatially resolved transcriptomics on lung cancer specimens obtained from usual interstitial pneumonia (UIP) associated lung cancer patients. In a total of 10 patients, including five lung cancers that developed inside the UIP and five lung cancers that originated outside the UIP, regions of interest (ROIs) were selected in the tumoral tissues and their adjacent non-tumor tissues. Then, gene expression profiles were comprehensively analyzed by using GeoMx digital spatial profiler in each ROI. Results: In the UIP lesions adjacent to lung cancer, increased gene expressions associated with pulmonary fibrosis, such as COL1A1, COL3A1, and APOE, were observed, and gene set enrichment analysis (GSEA) revealed that they were associated with autoimmunity-related pathways. When we compared the tumor lesions developed inside the UIP with outside the UIP, increased gene expressions related to IP mortality were observed in the tumor cells developed inside the UIP. Interestingly, GSEA revealed that the gene set for neutrophil extracellular trap (NETs) formation was found to be upregulated in the tumor cells developed inside the UIP, suggesting that NETs plays an important role in the pathogenesis of lung cancer developed in IP lesion. Conclusions: In our study, spatially resolved transcriptomics revealed a novel pathway related to the pathogenesis of lung cancer associated with IP. Citation Format: Daisuke Mizuno, Kazuhiko Shien, Atsushi Matsuoka, Masayoshi Ohki, Shuta Tomida, Ryo Yoshichika, Tomoaki Higashihara, Fumiaki Mukohara, Naohiro Hayashi, Tomohiro Habu, Mao Yoshikawa, Ken Suzawa, Hiromasa Yamamoto, Daisuke Ennishi, Shinichi Toyooka. Molecular pathogenesis of lung cancer associated with interstitial pneumonia [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 3643.

Molecular pathology of non-small cell carcinoma.

Currently, lung cancer is treated by the highest number of therapeutic options and the benefits are based on multiple large-scale sequencing studies, translational research and new drug development, which has promoted our understanding of the molecular pathology of lung cancer. According to the driver alterations, different characteristics have been revealed, such as differences in ethnic prevalence, median age and alteration patterns. Consequently, beyond traditional chemoradiotherapy, molecular-targeted therapy and treatment with immune check-point inhibitors (ICI) also became available major therapeutic options. Interestingly, clinical results suggest that the recently established therapies target distinct lung cancer proportions, particularly between the EGFR/ALK and PD-1/PD-L1-positive subsets, e.g. the kinase inhibitors target driver mutation-positive tumours, whereas driver mutation-negative tumours respond to ICI treatment. These therapeutic efficacy-related differences might be explained by the molecular pathogenesis of lung cancer. Addictive driver mutations promote tumour formation with powerful transformation performance, resulting in a low tumour mutation burden, reduced immune surveillance, and subsequent poor response to ICIs. In contrast, regular tobacco smoke exposure repeatedly injures the proximal airway epithelium, leading to accumulated genetic alterations. In the latter pathway, overgrowth due to alteration and immunological exclusion against neoantigens is initially balanced. However, tumours could be generated from certain clones that outcompete immunological exclusion and outgrow the others. Consequently, this cancer type responds to immune check-point treatment. These pathogenic differences are explained well by the two-compartment model, focusing upon the anatomical and functional composition of distinct cellular components between the terminal respiratory unit and the air-conducting system.

Selective targeting of KRAS-driven lung tumorigenesis via unresolved ER stress.

Lung cancer with oncogenic KRAS makes up a significant proportion of lung cancers and is accompanied by a poor prognosis. Recent advances in understanding the molecular pathogenesis of lung cancer with oncogenic KRAS have enabled the development of drugs, yet mutated KRAS remains undruggable. We performed small-molecule library screening and identified verteporfin, a yes-associated protein 1 (YAP1) inhibitor; verteporfin treatment markedly reduced cell viability in KRAS-mutant lung cancer cells in vitro and suppressed KRAS-driven lung tumorigenesis in vivo. Comparative functional analysis of verteporfin treatment and YAP1 knockdown with siRNA revealed that the cytotoxic effect of verteporfin was at least partially independent of YAP1 inhibition. A whole-transcriptome approach revealed the distinct expression profiles in KRAS-mutant lung cancer cells between verteporfin treatment and YAP1 knockdown and identified the selective involvement of the ER stress pathway in the effects of verteporfin treatment in KRAS-mutant lung cancer, leading to apoptotic cell death. These data provide novel insight to uncover vulnerabilities in KRAS-driven lung tumorigenesis.

Abstract IA06: Molecular mechanisms of lung cancer development: Between metabolic reprogramming and genomic instability in the field of cancerization

Abstract Airway epithelial cells are prone to assault by risk factors and considered to be the primary cell type involved in the field of cancerization. To investigate risk-associated changes in the bronchial epithelium proteome that may offer new insights into molecular pathogenesis of lung cancer, proteins were identified in the airway epithelial cells of bronchial brushings specimens from risk-stratified individuals by shotgun proteomics. Differential expression of selected proteins was validated by parallel reaction monitoring mass spectrometry in an independent set of individual bronchial brushings. We identified over 300 proteins with a significant trend in expression. Pathway analysis revealed enrichment of carbohydrate metabolic enzymes in high-risk individuals. Glucose consumption and lactate production were increased in human bronchial epithelial BEAS2B cells treated with cigarette smoke condensate for seven months. Increased lipid biosynthetic capacity and net reductive carboxylation were revealed by metabolic flux analyses of [U-13C5] glutamine in this in vitro model, suggesting profound metabolic reprogramming in the airway epithelium of high-risk individuals. These results also pointed towards a fundamental role of glutamine and cysteine metabolism in lung cancer progression. Two amino acid transporters, specifically SLC1A5 and SLC7A11, captured our attention for their high level of expression in lung cancer. These transporters are associated with worse survival in lung cancer. A small-molecular inhibitor of SLC1A5 prevents tumor progression in nude mice, and a glutaminase inhibitor CB-839 exhibits radiosensitization to lung cancer cells, an effect that may be mediated by decreased GSH production. Taken together, these studies provide a rationale for new chemopreventive strategies, selection of patients for surveillance programs, and determining how metabolic reprogramming may contribute genomic instability a requirement to cancer development. Further investigation into how glutamine and cystine metabolism contribute to lung cancer development and progression may lead to novel early-interception strategies in lung cancer. This work is supported by NCI CA186145, CA152662, and DoD W81XWH-11-2-0161. Citation Format: Jamshed Rahman, Xiangming Ji, Chirayu Patel, Jamey Young, Pierre P. Massion. Molecular mechanisms of lung cancer development: Between metabolic reprogramming and genomic instability in the field of cancerization [abstract]. In: Proceedings of the Fifth AACR-IASLC International Joint Conference: Lung Cancer Translational Science from the Bench to the Clinic; Jan 8-11, 2018; San Diego, CA. Philadelphia (PA): AACR; Clin Cancer Res 2018;24(17_Suppl):Abstract nr IA06.

Molecular Pathology of Lung Cancer Cytology Specimens: A Concise Review.

- There has been a paradigm shift in the understanding of molecular pathogenesis of lung cancer. A number of oncogenic drivers have been identified in non-small cell lung carcinoma, such as the epidermal growth factor receptor ( EGFR) mutation and anaplastic lymphoma kinase ( ALK) gene rearrangement. Because of the clinical presentation at an advanced stage of disease in non-small cell lung carcinoma patients, the use of minimally invasive techniques is preferred to obtain a tumor sample for diagnosis. These techniques include image-guided biopsies and fine-needle aspirations, and frequently the cytology specimen may be the only tissue sample available for the diagnosis and molecular testing for these patients. - To review the current literature and evaluate the role of cytology specimens in lung cancer mutation testing. We reviewed the types of specimens received in the laboratory, specimen processing, the effect of preanalytic factors on downstream molecular studies, and the commonly used molecular techniques for biomarker testing in lung cancer. - PubMed and Google search engines were used to review the published literature on the topic. - Mutation testing is feasible on a variety of cytologic specimen types and preparations. However, a thorough understanding of the cytology workflow for the processing of samples and appropriate background knowledge of the molecular tests are necessary for triaging, and optimum use of these specimens is necessary to guide patient management.

The airway epithelium undergoes metabolic reprogramming in individuals at high risk for lung cancer.

The molecular determinants of lung cancer risk remain largely unknown. Airway epithelial cells are prone to assault by risk factors and are considered to be the primary cell type involved in the field of cancerization. To investigate risk-associated changes in the bronchial epithelium proteome that may offer new insights into the molecular pathogenesis of lung cancer, proteins were identified in the airway epithelial cells of bronchial brushing specimens from risk-stratified individuals by shotgun proteomics. Differential expression of selected proteins was validated by parallel reaction monitoring mass spectrometry in an independent set of individual bronchial brushings. We identified 2,869 proteins, of which 312 proteins demonstrated a trend in expression. Pathway analysis revealed enrichment of carbohydrate metabolic enzymes in high-risk individuals. Glucose consumption and lactate production were increased in human bronchial epithelial BEAS2B cells treated with cigarette smoke condensate for 7 months. Increased lipid biosynthetic capacity and net reductive carboxylation were revealed by metabolic flux analyses of [U-13C5] glutamine in this in vitro model, suggesting profound metabolic reprogramming in the airway epithelium of high-risk individuals. These results provide a rationale for the development of potentially new chemopreventive strategies and selection of patients for surveillance programs.

Abstract 2021: Identification of novel brachyury target genes in lung cancer

Abstract Lung cancer is the leading cause of cancer-related death worldwide. Previous studies have shown that the T-box transcription factor brachyury is commonly expressed in advanced lung cancer and is associated with a poor prognosis. The activation of brachyury promotes lung cancer progression, aggressiveness and resistance to conventional antitumor therapies. However, the mechanism by which brachyury drives lung cancer is unknown. Here we have sought to identify novel gene targets of brachyury to better understand the molecular pathogenesis of lung cancer. We used a bioinformatics approach and found a shortlist of putative potential brachyury target genes. We subsequently explored the modulation of candidate brachyury target genes in lung cancer. RNA interference analysis for lung cancer cell line H460 overexpressing brachyury demonstrated that fibroblast growth factor 8 (FGF8), MAS1 Proto-Oncogene G Protein-Coupled Receptor (MAS1) and Ran GTPase Activating Protein 1 (RANGAP1) played essential roles in cell growth, whereas transmembrane protein 37 (TMEM37) was involved in cell migration and invasion. ChIP-qPCR experiments confirmed the strong binding of brachyury to these functional target genes. Analysis of datasets derived from patients with lung cancer and a panel of lung cancer cell lines revealed that brachyury expression was positively correlated with FGF8, MAS1, RANGAP1 and TMEM37. In addition, the expression levels of FGF8, MAS1 and RANGAP1 were significantly associated with non-metastasis (early-stage and locally advanced lung cancer), whereas TMEM37 was associated with metastasis. Taken together, our findings suggest that brachyury may influence lung cancer progression and/or metastasis via direct regulation of FGF8, MAS1, RANGAP1 and TMEM37 expression. Identification of potential brachyury transcriptional targets provides novel insights into the molecular pathobiology of lung cancer. Citation Format: Yunping Hu, Wesley Hsu. Identification of novel brachyury target genes in lung cancer. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 2021.

Early Events in the Molecular Pathogenesis of Lung Cancer.

The majority of cancer-related deaths in the United States and worldwide are attributed to lung cancer. There are more than 90 million smokers in the United States who represent a significant population at elevated risk for lung malignancy. In other epithelial tumors, it has been shown that if neoplastic lesions can be detected and treated at their intraepithelial stage, patient prognosis is significantly improved. Thus, new strategies to detect and treat lung preinvasive lesions are urgently needed in order to decrease the overwhelming public health burden of lung cancer. Limiting these advances is a poor knowledge of the earliest events that underlie lung cancer development and that would constitute markers and targets for early detection and prevention. This review summarizes the state of knowledge of human lung cancer pathogenesis and the molecular pathology of premalignant lung lesions, with a focus on the molecular premalignant field that associates with lung cancer development. Lastly, we highlight new approaches and models to study genome-wide alterations in human lung premalignancy in order to facilitate the discovery of new markers for early detection and prevention of this fatal disease. Cancer Prev Res; 9(7); 518-27. ©2016 AACR.

Bis Expression in Patients with Surgically Resected Lung Cancer and its Clinical Significance.

Bis, also known as BAG3, has been identified as a Bcl-2-interacting protein that enhances cellular anti-apoptotic activity. It is involved in cellular differentiation, angiogenesis, migration, and invasion in various tumors. The purpose of this study was to investigate the Bis expression pattern, and the clinical significance thereof, in patients with resected lung cancer. We studied 121 lung cancer patients who underwent curative surgical resection. Patient clinicopathological characteristics were reviewed retrospectively from medical records, including tumor recurrence and survival. The expression of Bis protein in lung cancer tissues was evaluated by immunohistochemical staining and was assessed using a four-tiered intensity score system (negative, weak, moderate, strong). Enhanced Bis expression at the periphery of a tumor facing the adjacent nontumor region was referred as "marginal activity." Although Bis expression was higher in squamous cell carcinoma than in adenocarcinoma, marginal activity was higher in adenocarcinoma than in squamous cell carcinoma. All of the small cell carcinomas and lung cancer with neuroendocrine differentiation examined were negative for Bis expression. Compared with stage I lung cancer, patients with stage II and IIIA lung cancer exhibited higher Bis protein levels in lung tissues. Recurrence and survival rates did not differ significantly according to Bis expression intensity score or marginal activity. Our study demonstrated that Bis expression differed according to the histological type and pathological stage of the lung cancer. Further studies are needed to assess its use as a biomarker and its role in the molecular pathogenesis of lung cancer.

Matrix metalloproteinase-19 promotes metastatic behavior in vitro and is associated with increased mortality in non-small cell lung cancer.

Lung cancer is the leading cause of cancer death in both men and women in the United States and worldwide. Matrix metalloproteinases (MMPs) have been implicated in the development and progression of lung cancer, but their role in the molecular pathogenesis of lung cancer remains unclear. We have found that MMP19, a relatively novel member of the MMP family, is overexpressed in lung tumors when compared with control subjects. To test the hypothesis that MMP19 plays a significant role in the development and progression of non-small cell lung cancer (NSCLC). We have analyzed lung cancer gene expression data, immunostained lung tumors for MMP19, and performed in vitro assays to test the effects of MMP19 in NSCLC cells. We found that MMP19 gene and protein expression is increased in lung cancer tumors compared with adjacent and histologically normal lung tissues. In three independent datasets, increased MMP19 gene expression conferred a poorer prognosis in NSCLC. In vitro, we found that overexpression of MMP19 promotes epithelial-mesenchymal transition, migration, and invasiveness in multiple NSCLC cell lines. Overexpression of MMP19 with a mutation at the catalytic site did not impair epithelial-mesenchymal transition or expression of prometastasis genes. We also found that miR-30 isoforms, a microRNA family predicted to target MMP19, is markedly down-regulated in human lung cancer and regulates MMP19 expression. Taken together, these findings suggest that MMP19 is associated with the development and progression of NSCLC and may be a potential biomarker of disease severity and outcome.

Loss of miR125a expression in a model of K-ras-dependent pulmonary premalignancy.

Understanding the molecular pathogenesis of lung cancer is necessary to identify biomarkers/targets specific to individual airway molecular profiles and to identify options for targeted chemoprevention. Herein, we identify mechanisms by which loss of microRNA (miRNA)125a-3p (miR125a) contributes to the malignant potential of human bronchial epithelial cells (HBEC) harboring an activating point mutation of the K-ras proto-oncogene (HBEC K-ras). Among other miRNAs, we identified significant miR125a loss in HBEC K-ras lines and determined that miR125a is regulated by the PEA3 transcription factor. PEA3 is upregulated in HBEC K-ras cells, and genetic knockdown of PEA3 restores miR125a expression. From a panel of inflammatory/angiogenic factors, we identified increased CXCL1 and vascular endothelial growth factor (VEGF) production by HBEC K-ras cells and determined that miR125a overexpression significantly reduces K-ras-mediated production of these tumorigenic factors. miR125a overexpression also abrogates increased proliferation of HBEC K-ras cells and suppresses anchorage-independent growth (AIG) of HBEC K-ras/P53 cells, the latter of which is CXCL1-dependent. Finally, pioglitazone increases levels of miR125a in HBEC K-ras cells via PEA3 downregulation. In addition, pioglitazone and miR125a overexpression elicit similar phenotypic responses, including suppression of both proliferation and VEGF production. Our findings implicate miR125a loss in lung carcinogenesis and lay the groundwork for future studies to determine whether miR125a is a possible biomarker for lung carcinogenesis and/or a chemoprevention target. Moreover, our studies illustrate that pharmacologic augmentation of miR125a in K-ras-mutated pulmonary epithelium effectively abrogates several deleterious downstream events associated with the mutation.

MiR-21: A Non-invasive Biomarker and Potential Therapeutic Target for Lung Cancer?

We read with great interest the article, published in Cell Biochem Biophys, showing that serum level of miR-21 was significantly elevated in lung cancer patients compared with controls. Receiver operating characteristic (ROC) curve analysis showed that miR-21 could differentiate lung cancer from healthy controls with an AUC (the area under the curve) of 0.85, and the optimal sensitivity and specificity were 85.7 and 86.5 %, respectively [1]. These findings suggest that miR-21 can be a potential non-invasive biomarker for lung cancer patients and miR-21 may be a potential therapeutic target for lung cancer. Lung cancer is one of the most common malignant tumors and is the leading cause of cancer mortality in the world [2]. Non-small cell lung cancer (NSCLC) accounts for approximately 80–85 % of all cases of lung cancer [3]. Despite much advances in lung cancer therapy, the survival rate for lung cancer patients remains very poor [4]. Recent advances in functional genomics provide an increasingly comprehensive portrayal of lung tumorigenesis, but the molecular pathogenesis of lung cancer remains poorly understood. These findings highlight the need for a better understanding of novel molecular mechanisms to guide treatment of lung cancer. MicroRNAs (miRNAs) are small non-coding RNAs that repress target gene expression by a combination of mRNA degradation and translation inhibition [5]. Recently, miR-21 expression was found to be higher in lung cancer serum samples than in control serum samples [3, 6–9]. High serum miR-21 was significantly correlated with tumor node metastases stage and lymph node metastasis of NSCLC patients [3, 5]. Overexpression of miR-21 showed a highly discriminative ROC curve profile, clearly distinguishing cancer patients from cancer-free subjects, and the detection of miR-21 expression yielded high sensitivity and specificity in the diagnosis of lung cancer [7–9]. Furthermore, miR-21 expression was elevated in human lung cancer cell lines (NCI-H446 and NCI-H460) [2]. Human mutS homolog 2 (hMSH2), one of the core mismatch repair genes, is affected in lung cancer development. Zhong et al. [2] found that hMSH2 was directly regulated by miR-21, and miR-21 expression was inversely correlated with hMSH2 expression in human lung cancer cell lines [2]. Notably, upregulation of miR-21 markedly promoted cell proliferation and revealed a higher proportion of cells at S phase. However, knockdown of miR-21 expression led to cell cycle arrest at G2/M phase and inhibited cell proliferation [2]. Similarly, tumor tissues showed an inverse correlation between high expression of miR-21 and low amounts of PTEN protein, where miR-21 suppresses PTEN by direct binding to the 30-UTR of PTEN [5]. Lung cancer cell lines (A549, H1703, and 801D) transfected with miR-21 inhibitor showed decreased endogenous miR-21 levels but significantly increased PTEN protein expression [5]. In addition, A549 and H1703 cells transfected with miR-21 inhibitor could restrain the growth of A549 and H1703 cells, and downregulation of miR-21 with miR-21 inhibitor in 801D cells could restrain its invasion ability [5]. Collectively, available evidence suggests that miR-21 may be a good biomarker for detection of lung cancer, and miR-21 may play an important role in lung cancer. However, further studies, especially in human systems, are needed to comprehensively explore the role of miR-21 in lung cancer, and miR-21 may be a potential therapeutic target for lung cancer. S.-C. Wang (&) Y.-F. Zhang Q. Xie PET/CT Center, Anhui Provincial Hospital, 17 Lujiang Road, Hefei 230001, Anhui, People’s Republic of China e-mail: wangsc3329@163.com

A Novel Molecular Pathway for Snail-Dependent, SPARC-Mediated Invasion in Non–Small Cell Lung Cancer Pathogenesis

Definition of the molecular pathogenesis of lung cancer allows investigators an enhanced understanding of the natural history of the disease, thus fostering development of new prevention strategies. In addition to regulating epithelial-to-mesenchymal transition (EMT), the transcription factor Snail exerts global effects on gene expression. Our recent studies reveal that Snail is upregulated in non-small cell lung cancer (NSCLC), is associated with poor prognosis, and promotes tumor progression in vivo. Herein, we demonstrate that overexpression of Snail leads to the upregulation of secreted protein, acidic and rich in cysteine (SPARC) in models of premalignancy and established disease, as well as in lung carcinoma tissues in situ. Snail overexpression leads to increased SPARC-dependent invasion in vitro, indicating that SPARC may play a role in lung cancer progression. Bioinformatic analysis implicates transforming growth factor beta (TGF-β), extracellular signal-regulated kinase (ERK)1/2, and miR-29b as potential intermediaries in Snail-mediated upregulation of SPARC. Both the TGF-β1 ligand and TGF-β receptor 2 (TGF-βR2) are upregulated following Snail overexpression. Treatment of human bronchial epithelial cell (HBEC) lines with TGF-β1 and inhibition of TGF-β1 mRNA expression modulates SPARC expression. Inhibition of MAP-ERK kinase (MEK) phosphorylation downregulates SPARC. MiR-29b is downregulated in Snail-overexpressing cell lines, whereas overexpression of miR-29b inhibits SPARC expression. In addition, miR-29b is upregulated following ERK inhibition, suggesting a Snail-dependent pathway by which Snail activation of TGF-β and ERK signaling results in downregulation of miR-29b and subsequent upregulation of SPARC. Our discovery of pathways responsible for Snail-induced SPARC expression contributes to the definition of NSCLC pathogenesis.

New Molecular Targets in the Treatment of NSCLC

Lung cancer is the leading cause of mortality world-wide. Non Small Cell Lung Cancer (NSCLC) is a particularly aggressive cancer, the optimum management of which is still being determined. In the next years modest survival improvement can be expected by chemotherapy. Advances in understanding of the molecular pathogenesis of lung cancer have led to the identification of several specific targets for therapeutic agents. Targeting the epidermal growth factor receptor (EGFR) has played a central role in advancing NSCLC research, treatment, and patient outcome over the last several years. In lung cancer, 10-15% of NSCLC contain activating mutations in the EGFR kinase conferring hypersensitivity to the oral TKIs gefitinib and erlotinib, have been demonstrated to be important predictive factors when selecting patients to be treated with these two agents. More recently, another molecular abnormality, the translocation of the anaplastic lymphoma kinase (ALK) gene that drives NSCLC in a different group of patients has been found in 4 to 5% of NSCLC. The rearrangement results in an EML4 - AKL fusion gene, which increases ALK activity. Inhibitors of ALK kinase have been developed and investigated. Crizotinib, an orally ALK and met proto-oncogene (MET) inhibitor, was very well tolerated and produced dramatic antitumor activity in early-stage trials which facilitated a faster than normal move into late-stage trials for EML4-ALK -positive NSCLC patients treatment. In a phase III randomized that showed progression free survival benefit as compared to chemotherapy in second-line setting. Several novel selective inhibitors of ALK kinase are currently in preclinical or early clinical testing. Since the discovery that Met pathway is one of the most frequently dysregulated pathways in human cancer, Met inhibitors, with varying kinase selectivity profiles ranging from highly selective to multi-targeted have been studied in the clinic and good progress has been achieved. A number of studies suggest that the PI3K/Akt signaling pathway is central to NSCLC growth and survival. Given the importance of activated PI3K signaling in cancer, several PI3K inhibitors are currently one of the most recent drug targets in oncology, with several small molecules in early stages of clinical development. This review will focus on the role of EGFR, ALK, MET, and PI3K inhibitors in the treatment of NSCLC.

A Screening Method for the ALK Fusion Gene in NSCLC

Lung cancer research has recently made significant progress in understanding the molecular pathogenesis of lung cancer and in developing treatments for it. Such achievements are directly utilized in clinical practice. Indeed, the echinoderm microtubule-associated protein-like 4–anaplastic lymphoma kinase (ALK) fusion gene was first described in non-small cell lung cancer in 2007, and a molecularly targeted drug against the fusion was approved in 2011. However, lung cancer with the ALK fusion constitutes only a small fraction of lung cancers; therefore, efficient patient selection is crucial for successful treatment using the ALK inhibitor. Currently, RT-PCR, fluorescent in situ hybridization (FISH), and immunohistochemistry are commonly used to detect the ALK fusion. Although FISH is currently the gold standard technique, there are no perfect methods for detecting these genetic alterations. In this article, we discuss the advantages and disadvantages of each method and the possible criteria for selecting patients who are more likely to have the ALK fusion. If we can successfully screen patients, then ALK inhibitor treatment will be the best example of personalized therapy in terms of selecting patients with an uncommon genotype from a larger group with the same tumor phenotype. In other words, the personalized therapy may offer a new challenge for current clinical oncology.

Molecular Pathogenesis of Non-Small Cell Lung Carcinomas

Non-small cell lung carcinoma (NSCLC) from histological and biological perspectives is a complex neoplasm. The sequential preneoplastic changes have been defined for centrally arising squamous cell carcinomas (SCCs) of the lung, and they are less documented for peripherally arising adenocarcinomas. The main morphologic forms of preneoplastic lesions recognized in the lung are squamous dysplasias for SCC, and atypical adenomatous hyperplasia for adenocarcinoma. Several studies have provided information regarding the molecular characterization of lung preneoplastic changes, especially for SCC. These molecular changes have been detected in the histologically normal and abnormal respiratory epithelium of smokers and patients with lung cancer, phenomenon known as field of cancerization. Our improved understanding of the changes and origins of the field of cancerization can be applied clinically to improve early detection of lung cancer. In the last decade, significant progress has been made in the characterization of molecular abnormalities in NSCLC tumors that are being used as molecular targets and predictive biomarkers for patients’ selection for targeted therapy. As our understanding of the biology of the molecular pathogenesis of lung cancer evolves, there is an opportunity to use this knowledge for the development of novel chemoprevention strategies using those molecularly targeted agents used to treat advanced lung cancer, a concept coined as reverse migration. The rapid development of technologies for large-scale molecular analysis, includeing microarrays and next-generation sequencing will facilitate high-throughput molecular analysis of lung cancer preneoplastic lesions and the field of cancerization.

Targetable “Driver” Mutations in Non Small Cell Lung Cancer

Lung cancer remains the leading cause of cancer-related mortality in the world despite advances in the field of cancer therapeutics. Traditional treatment with empirically chosen cytotoxic chemotherapeutic agents, have given small, but real survival benefits. Recent advances and insights into molecular pathogenesis of lung cancers have provided some novel molecular targets, offering newer strategies and agents that are tumor specific. Studies have identified mutations in specific genes that are involved in driving the development of lung cancer and so it is important to subsequently target them with specific drugs thus changing paradigms of management of this type of cancer. Recently, Lung Cancer Mutation Consortium (LCMC) has identified at least one of the many recognized "driver mutations" in nearly two thirds of the patients with advanced cancer. This study suggests that identification of driver mutations can help in molecular targeted therapeutics and in addition supplant tumor histology in guiding treatment decisions, identifying subset of patients who may benefit therapy. This review focuses on these mutations identified in specific genes serving as "drivers" of lung tumorigenesis and suggests that clear promise for the future of lung cancer treatment is indeed personalized therapy with drugs chosen according to the patient mutation profile. Most clinically relevant translational advances made in genes involved in lung tumorigenesis namely EML4-ALK fusions, HER2, PIK3CA, AKT, BRAF, MAP2K1, MET mutations and amplifications along with the well established EGFR and KRAS mutations are discussed in the context of NSCLCs. These studies emphasize the need for treatment management based on mutation profile along with routine histology based classification of these tumors in future for a directed therapy and thus a better therapeutic outcome.

Treatment of advanced non small cell lung cancer.

Lung cancer is the major cause of cancer death in the world. Non Small Cell Lung Cancer (NSCLC) accounts approximately 80-85% of all lung cancer diagnosis; the majority of patients will be diagnosed with non operable, advanced-stage disease. Palliative chemotherapy and/or radiotherapy represent the standard of care of this disease. Platinum based doublets with third generation agents are considered the standard of first line advanced NSCLC treatment. However, data arising from the availability of pemetrexed suggest that histology could play a key role in decision making. Advances in understanding of the molecular pathogenesis of lung cancer have led to the identification of several specific targets such as vascular endothelial growth factor (VEGF) and epidermal growth factor receptor (EGFR) for therapeutic agents. Bevacizumab is the first recombinant humanized monoclonal antibody (mAb) binding VEGF to demonstrate clinical benefit and a rather survival prolongation in combination with chemotherapy in the treatment of non squamous chemo-naive advanced NSCLC patients. Two types of anti-EGFR targeting agents have reached advanced clinical development: mAbs and small molecule inhibitors of the EGFR tyrosine kinase enzymatic activity (TKIs). Among TKIs gefitinib has been tested in several phase II-III studies showing an improvement in survival and responses in first, second and third line treatment in selected patients with specific clinical and molecular characteristics. Furthermore, erlotinib has showed to significantly improve survival in an unselected population of patients following the failure of one or two chemotherapy regimens. This review will discuss the different therapeutic options for first and second line treatment in the clinical practice.

Abstract 3419: Defining the role of ZEB1 in the molecular pathogenesis of lung cancer

Abstract Background: Epithelial-to-mesenchymal transition (EMT) is an important biologic process in cancer resulting in enhanced migration, invasiveness, and therapeutic resistance. The transcription factor ZEB1 promotes EMT and tumor metastasis in several human cancers yet its role in the pathogenesis of lung cancer is less well defined. In addition to a large panel of lung cancer lines, our laboratory has developed an isogenic series of human bronchial epithelial cells (HBECs) – immortalized without viral oncoproteins – genetically manipulated with single and multiple oncogenic changes common in lung cancer (sh-p53, KRASV12, mutant EGFR, and c-MYC), providing an invaluable resource to study the progression of bronchial epithelial cells towards malignancy. Methods and Results: ZEB1 expression was analyzed by qRT-PCR across a panel of 77 non small cell lung cancer (NSCLC) lines to test for a direct correlation with ‘M’ status and indirect correlation with CDH1 expression and ‘E’ status. Genome-wide mRNA expression profiling of the NSCLC cell line cohort using Affymetrix U133 Plus 2.0 arrays was used to identify novel ZEB1-associated genes. Expression of the ephrin receptor EPHA1 significantly inversely correlated with ZEB1 expression. This was confirmed in independent siRNA experiments where knockdown of ZEB1 resulted in an increase in EPHA1 in both NSCLC cell lines and oncogenically transformed HBECs. To characterize the role of ZEB1 in the oncogenic progression of bronchial epithelial cells, ZEB1 was analyzed across our series of genetically manipulated HBECs. Expression of ZEB1 was generally absent, but was highly up-regulated with the combination of p53-knockdown, KRASV12, and c-MYC over-expression. This onco-genetic combination led to the most tumorigenic phenotype in vivo accompanied with a switch from ‘E’ to ‘M’ status. The functional importance of ZEB1 was seen with siRNA knockdown of ZEB1 resulting in a significant decrease in soft agar colonies, transwell invasiveness, and motility suggesting ZEB1 is a crucial driver of tumorigenicity in sh-p53 + KRASV12 + c-MYC transformed HBECs. To confirm the oncogenic role of ZEB1 in lung cancer, shRNA-mediated knockdown of ZEB1 was performed in several NSCLC cell lines, leading to a significant decrease in soft agar colonies, transwell invasiveness, motility, and 3D growth. Subcutaneous injection into NOD/SCID mice found inhibition of tumor growth in shZEB1 knockdown lines. Finally, loss of ZEB1 expression in NSCLCs and transformed HBECs resulted in a decrease in a “cancer stem cell” like population detected by ALDH activity. Conclusion: These findings involving mechanistic studies in NSCLC lines and oncogenically manipulated HBECs demonstrate the prominent role of ZEB1 function in EPHA1 expression, EMT, tumorigenicity, and the invasive phenotype of lung cancer, supporting the important role of ZEB1 in the pathogenesis of lung cancer making it an important new therapeutic target. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 3419. doi:10.1158/1538-7445.AM2011-3419

Imaging of Lung Cancer in the Era of Molecular Medicine

Recent discoveries characterizing the molecular basis of lung cancer brought fundamental changes in lung cancer treatment. The authors review the molecular pathogenesis of lung cancer, including genomic abnormalities, targeted therapies, and resistance mechanisms, and discuss lung cancer imaging with novel techniques. Knowledge of the molecular basis of lung cancer is essential for radiologists to properly interpret imaging and assess response to therapy. Quantitative and functional imaging helps assessing the biologic behavior of lung cancer.