1. Introduction
Lung cancer is the leading cause of cancer deaths in the world, which is a cause for more solid tumor-related deaths than all other carcinomas combined. More than 170,000 new cases are diagnosed each year in the United States alone, of whom ~160,000 will eventually die, accounting for nearly 30% of all cancer deaths (Siegel et al., 2012). The annual incidence for lung cancer per 100,000 population is highest among African Americans (76.1), followed by whites (69.7), American Indians/Alaska Natives (48.4), and Asian/Pacific Islanders (38.4). Hispanic people have much lower lung cancer incidence (37.3) than non-Hispanics (71.9) (CDC, 2010). These results identify the racial/ethnic populations and geographic regions that would benefit from enhanced efforts in lung cancer prevention, specifically by reducing cigarette smoking and exposure to environmental carcinogens.
Lung lobectomy provides the best chance for patients with early-stage disease to be cured. African American patients with early-stage lung cancer have lower five-year survival rates than whites, which has been attributed to lower rates of resection in former patients (Wisnivesky et al., 2005). Several potential factors underlying racial differences in receiving surgical therapy include differences in pulmonary function, access to care, beliefs about tumor spread at the time of operation, and the possibility of cure without surgery. Of these, access to care is considered to be the most important factor underlying racial disparities.
The most outstanding modifiable risk factor for lung cancer is cigarette smoking (Swierzewski III, 2011). Other risk factors include asbestos exposure, radon, occupational chemicals, radiation, and alcohol. People who smoke tend to drink more alcohols and consume more non-narcotic pain relievers than non-smokers, thus reducing the intoxicating effects of alcohol, promoting the progression from moderate to heavy drinking. Alcoholism is also associated with significant immune suppression - therefore, a history of drinking may increase a person's susceptibility to lung cancer.
Lung cancer has a high morbidity because it is difficult to detect early and is frequently resistant to available chemotherapy and radiotherapy. The overall 5-year survival rate for all types of lung cancer is around 15 % at most, and it is even worse in SCLC (~5 %) although SCLC is more sensitive to chemo/radiation therapy than NSCLC (Meuwissen & Berns, 2005; Schiller, 2001; Worden & Kalemkerian, 2000). Non-smokers who develop lung cancer may experience delays in diagnosis due to the fact that many early symptoms of lung cancer mimic those of non-specific respiratory infections (Menon, 2012). Thus, a physician may misdiagnose the malignant disease for asthma or other respiratory illnesses. Another reason for delayed diagnosis of lung cancer is that there is no sensitive and specific biomarker, such as prostate-specific antigen in prostate cancer (Brambilla et al., 2003). Thus several biomarkers will have to be used together for early diagnosis of lung cancer at present, which include mutant Ras, mutant p53, and methylation of a variety of genes using bronchial biospies or bronchoalveolar lavage (Brambilla et al., 2003).
Certain combinations of clinical signs and symptoms – e.g. endocrine, neurologic, immunologic, and hematologic - are associated with lung cancer as a manifestation of the secretion of cytokines/hormones by tumor cells or as an associated immunologic response (Yeung et al., 2011). These paraneoplastic syndromes occur commonly in patients with SCLC. Since the syndromes can be the first clinical manifestation of malignant disease, increased awareness of these syndromes associated with lung cancer is critical to the earlier diagnosis of malignancies, thereby improving the overall prognosis of patients.
Lung cancer has been categorized into two major histopathological groups: non-small-cell lung cancer (NSCLC) (Moran, 2006) and small-cell lung cancer (SCLC) (Schiller, 2001), the latter of which show neuroendocrine features and thus are different from the former. Approximately 80 % of lung cancers are NSCLC, and they are subcategorized into adenocarcinomas (AdCA), squamous cell (SqCLC), bronchioalveolar, and large-cell carcinomas (LCLC) (Travis, 2002). SCLC and NSCLC show major differences in histopathologic characteristics that can be explained by the distinct patterns of genetic alterations found in both tumor types (Zochbauer-Muller et al., 2002). The
Progress in whole genome approaches to detect genetic alterations found in human lung cancer has resulted in the identification of a growing number of genes. Genome-wide association studies, whether they are based on single-nucleotide polymorphism array or in gene copy number assays, have identified mutations in lung cancer-related genes. Identification of these lung cancer-related genes will provide great potential as therapeutic targets for lung cancer intervention. Target validation should be done through intervention studies of specific genetic alterations in human lung cancer cell lines. Since
While susceptibility and incidence of spontaneous lung tumors vary among well-established mouse strains, endogenous mouse lung tumors share many similarities with human lung cancers. This was clearly demonstrated in early studies where defined chemical carcinogens were used to induce lung tumors in mice (Wakamatsu et al., 2007). The incidence of spontaneous and induced lung tumors were very high (61%) in A/J and SWR strains, but very low (6%) in resistant strains such as C57BL/6 and DBA (Wakamatsu et al., 2007). Contrary to human lung cancer with its complex molecular genetics and four distinct tumor types (adenocarcinoma, squamous cell carcinoma, large-cell carcinoma, and small-cell carcinoma) that easily metastasize, spontaneous and chemically-induced lung lesions in mice often result in pulmonary adenomas and more infrequent adenocarcinomas. Mouse lung adenocarcinomas are usually 5mm or more in diameter; however, they are categorized into carcinomas when nuclear atypia or signs of local invasion/metastasis is found in tumors less than 5mm. Mouse lung tumor development shows initial hyperplastic foci in bronchioles and alveoli, which then become benign adenomas and eventually adenocarcinomas (Shimkin et al., 1975). The tumor latency depends on mouse strain and carcinogen administration protocols. Most potent carcinogens are found in cigarettes, such as polycyclic aromatic hydrocarbons, tobacco-specific nitrosamine, and benzopyrene (BaP) (Pfeifer et al., 2002). It has been especially difficult to reproduce well-characterized pre-malignant lesions found in human airway epithelium in mice (Sato et al., 2007). Nevertheless, major histopathological features remain the same between the two species and molecular characterization of spontaneous and carcinogen-induced murine lung tumors revealed a high degree of similarity as compared to their human counterparts (Malkinson, 2001). A common early event is the occurrence of activating
2. The first generation mouse models for lung cancer
The first generation transgenic models for lung cancer were created by ectopic transgene expression under control of lung-specific promoters. Thus transgenic expression was constitutive. Transgene expression was mainly found in specific subsets of lung epithelial cells. Lung
Ehrhardt et al. (2001) created transgenic mouse models to study tumorigenesis of bronchiolo-alveolar AdCAs derived from alveolar type II pneumocytes. Transgenic lines expressing c-
Sunday
A strong correlation exists between
The receptor tyrosine kinase RON (recepteur d’origine nantais) is a member of the MET proto-oncogene family, which is expressed by a variety of epithelial-derived tumors and cancer cell lines and has been implicated in the pathogenesis of lung adenocarcinomas (Chen et al., 2002). To determine the oncogenic potential of RON, transgenic mice were generated using the lung
Many prominent genetic lesions found in human lung cancer clearly link the inactivation of well-known tumor suppressor genes (Sekido et al., 2003) to lung cancer development. Initial attempts to mimic some of these lesions implicated in lung cancer by using conventional knockout mice had limited success with respect to the onset of lung cancer. The main reason for this failure was that germ-line deletion of many essential tumor suppressor genes (such as the
Targeting genes deleted early in human lung tumorigenesis, such as the complete cluster at chromosome 3p21.3, showed that heterozygous deletion for this 370 kb region showed no obvious predisposition for lung cancer development albeit homozygous deletion caused embryonal lethality (Smith et al., 2002). A more specific deletion of candidate tumor suppressor genes on chromosome 3 like
3. The second generation models
3.1. K-rasLA and LSL K-ras models
A different approach to address lung cancer onset was the use of knock-in alleles to activate oncogenes. One example of this is based on the somatic
Dmp1 (Dmtf1) is a Myb-like protein with tumor suppressive activity that had been isolated in a yeast two-hybrid screen with cyclin D2 bait (Hirai and Sherr, 1996; Inoue and Sherr, 1998; for review, Inoue et al., 2007; Sugiyama et al., 2008a). The promoter is activated by oncogenic Ras-Raf signaling and induces cell-cycle arrest in an Arf, p53-dependent fashion (Inoue et al., 1999; Sreeramaneni et al., 2005). Both
Integration of gene expression data from a
Since activating
3.2. Doxycycline (dox)-inducible/de-inducible lung cancer models
Therefore, on/off target gene expression is possible depending on administration or withdrawal of tet/dox (Gossen et al., 1992). Both
Other models for early, benign lung tumor lesions have been created by using a bitransgenic
3.3. Cre/loxP or Flp/Frt models
The
The determining factor of this conditional approach is the control of temporal-spatial Cre or FRT recombinase expression. For that purpose, several
4. Specific oncogenes in mouse lung cancer models
4.1. Kras downstream effectors and lung cancer − Roles of Raf
Since
In another study, Ji
The significance of c-Raf was also investigated in
Further investigation during
By using
4.2. PI3K and lung cancer
Another important pro-survival pathway that is interlinked with RAS is PI3K/Akt signaling pathway. Phosphoinositide-3-kinase (PI3K) consists of a regulatory (p85) and a catalytic (p110) subunit. The overexpression of both subunits was reported in lung carcinomas (Samuels & Velculescu 2004; Wojtalla et al., 2011). Furthermore, selective
4.3. Rac and lung cancer
Rac is a member of the Rho family of small GTPases, and it mediates the regulation of various important cellular processes including cell migration, proliferation and adhesion, all of which may contribute to tumorigenesis (Mack et al., 2011). The important role of Rac in Ras induced lung tumorigenesis was demonstrated in a mice model in which an oncogenic allele of
4.4. Receptor-type protein tyrosine kinase and lung cancer − Roles of EGFR
4.4.1. EGFR and lung cancer
Epidermal growth factor (EGF) receptor family is one type of RTKs, on which the tyrosine residues phosphorylation lead to activation of downstream TK signaling that contributes to cell proliferation, motility and invasion (Stella et al., 2012). The activation mutations on
4.5. HER2 and lung cancer
The c-
HER2 receptor overexpression has been reported in 11% to 32% of NSCLC tumors, with gene amplification found in 2%-23% of cases (Hirsch et al., 2009; Swanton et al., 2006). High-level ERBB2 amplification occurs in a small fraction of lung cancers with a strong propensity to high-grade adenocarcinomas (Grob et al., 2012). The frequency of
While HER2 is overexpressed in about 20% of lung cancers, mutations in HER2 also occur in about 2-3% of cases. HER2 mutations typically occur in adenocarcinomas and are more frequent in women and never-smokers (Pinder, 2011). Mutations in HER2 lead to constitutive activation of the HER2 receptor, similar to the situation with EGFR. In good contrast to what we experienced in breast cancer, early clinical trials of Herceptin combined with chemotherapy in lung cancer patients with HER2 overexpression did not show a benefit for patients. However, there are case reports of lung cancer with HER2 mutations who have responded well to treatment with Herceptin plus chemotherapy. For instance, BIBW2992 (a small molecule inhibitor of EGFR and HER2) has shown evidence of activity in lung cancer patients with HER2 mutations. Most of the patients described had cancers that had shown resistance to chemotherapy and/or EGFR inhibitors. More patients with SCLC should be screened for HER2 mutations since the number of patients described to date is too small to draw any definitive conclusions (Pinder, 2011).
4.6. Cyclin D1 and lung cancer
The development of human lung carcinogenesis is very complex. Several oncogenes involved in this process have been identified, one of which is cyclin D1 (Meuwissen & Berns, 2005). Cyclin D1 is a crucial regulator in mammalian cell cycle, which drives cells to enter S phase by binding and activating CDK4/6. The cyclin D1/CDK4 complex phosphorylates the retinoblastoma protein (pRb), which releases E2F transcriptional factors from pRb constraint. The E2Fs can then activate genes that are required for the cell to enter S phase (Sherr, 1996, 2004). Cyclin D1 overexpression results in deregulation of phosphorylation of pRB, which can cause loss of growth control. In fact, Cyclin D1 gene and protein products are frequently overexpressed in a wide rang of cancers. In NSCLC, the
The ability of cyclin D1 to cause malignant transformation has been demonstrated in breast cancer transgenic mice model, in which
Cancer chemoprevention uses dietary or pharmaceutical agents to suppress or prevent carcinogenic progression to invasive cancer. In a recent study, it was shown that a combination of retinoid bexarotene and EGFR inhibitor erlotinib can suppress lung carcinogenesis in transgenic lung cancer cells as well as NSCLC patients in both early and advanced stages. Bexarotene can induce the proteasomal degradation of cyclin D1 and erlotinib can act as an inhibitor of EGFR which represses transcription of cyclin D1 (Kim et al., 2011). This finding implicates cyclin D1 as a chemopreventive target and the combination of bexarotene and erlotinib is an attractive candidate for lung cancer chemoprevention (Dragnev et al., 2011). Before using this regimen in clinical lung cancer chemoprevention, its activity should first be tested in clinically predictive cyclin D1 mouse lung cancer models.
4.7. PTEN and lung cancer
Since expression of phosphatase and tensin homologue deleted from chromosome 10 (PTEN; reviewed in Inoue et al., 2012) is often down regulated in NSCLC, several mice models have been generated in which
4.8. LKB1 and lung cancer − A novel player
Mutations in liver kinase B1 (
A large fraction of NSCLC cells have germ-line mutations and impaired expression of
The same group conducted a mouse trial that mirrors a human clinical trial in patients with KRAS-mutant lung cancers (Chen et al., 2012). They demonstrated that simultaneous loss of either
4.9. miRNAs and lung cancer
Not only might genetic mutations in oncogenes and tumor suppressor genes affect their target gene expression during lung tumorigenesis, but also microRNAs (miRNAs) can also perform similar roles. microRNAs are evolutionarily conserved, endogenous, non-protein coding, 20–23 nucleotide, single-stranded RNAs that negatively regulate gene expression in a sequence-specific manner. In order to become active, small interfering RNA (siRNA) must undergo catalytic cleavage by the RNase DICER1. In human lung cancer, increased activities of DICER1 and variant regulations of miRNA clusters have been observed. For the latter, a frequent down regulation of the
A large scale survey conducted by a different group to determine the miRNA signature of >500 lung, breast, stomach, prostate, colon, and pancreatic cancers and their normal adjacent tissue revealed that
Hennessey et al. (2012) conducted Phase I/II biomarker study to examine the feasibility of using serum miRNA as biomarkers for NSCLC. Examination of miRNA expression levels in serum from a multi-institutional cohort of 50 subjects (30 NSCLC patients and 20 healthy controls) identified differentially expressed miRNAs. They found that 140 candidate miRNA pairs distinguished NSCLC from healthy controls with a sensitivity and specificity of at least 80% each. Several miRNA pairs involving miRNAs-106a, miR-15b, miR-27b, miR-142-3p, miR-26b, miR-182, 126#, let7g, let-7i (described above) and miR-30e-5p exhibited a negative predictive value and a positive predictive value of 100%. Notably, a combination of two differentially expressed miRNAs
5. Mouse models for squamous cell lung cancer (SqCLC)
So far genomic alterations in SqCLC have not been comprehensively characterized. The Cancer Genome Atlas group recently profiled 178 lung squamous cell carcinomas to provide a comprehensive view of genomic and epigenomic alterations (Hammerman et al., 2012). They showed that the SqCLC is characterized by hundreds of exonic mutations, genomic rearrangements, and gene copy number alterations. In addition to
Although squamous cell carcinoma is a common type of lung cancer causing nearly 400,000 deaths per year worldwide, there is no established gene-engineered mouse model for squamous cell carcinoma of the lung. Human lung SqCLC is closely linked with smoking and shows a distinct order of pre-malignant changes in the bronchial epithelium from hyperplasia, metaplasia, dysplasia and carcinoma
The other group tried to induce SqCLC through constitutive expression of human K14 by creating
6. Clinical implications and future directions for mouse lung cancer models
Xenograft models where manipulated human lung cancer cell lines are subcutaneously injected into nude mice have been extensively used for pre-clinical testing of novel drugs for lung cancer. The major issue for this approach is that lung cancer cell lines have already been adapted for long-term culture in a plastic dish with artificial medium and acquired stem-cell like phenotypes, and thus are not suitable for models of primary human lung cancer obtained by surgical resection. The more preferred method, however, have been orthotopical transplantation of human lung tumor cells in their lung cavity. To date, the results have shown that xenograft models do not accurately predict the clinical efficacy of anti-tumor drugs. Therefore, a question arises as to whether spontaneous and/or genetically-engineered mouse models for lung cancer would be more useful as tools for pre-clinical drug tests. It is obvious that there are differences in the lung anatomy and physiology between mice and humans, but some of the mouse models that we have described have a striking histological similarity, with an analogous genetic signature to that of human NSCLC. Importantly, genetically-engineered mouse model-derived tumors develop in an innate immune environment and, therefore, have all the tumor-stromal interactions, such as angiogenesis and degradation of the tissue matrix.
We have described two models for NSCLC in which either the continuous oncogenic activity of Kras (Fisher et al, 2001) or EGFR (Politi et al, 2006) are prerequisites of tumor maintenance since lung tumors underwent spontaneous regression with disappearance of the oncogene by dox withdrawal. This not only shows that tumor growth critically depends on the initiating active oncogenic pathways, but it also stresses the usefulness of these oncogenic pathways as therapeutic targets. Direct tumor intervention studies with tyrosine kinase inhibitors against EGFR mutations proved to be highly effective in several
Other mouse models for NSCLC have also been used for targeted therapies. First, dox-induced overexpression of the PI3K p110α catalytic subunit PIK3CA, mutated in its kinase domain (H1047R) in
Although
The use of optimized, genetically-modified mouse models for lung cancer for therapy research necessitates sophisticated non-invasive tools to follow tumor development and response to therapy
Transgenic lung cancer models created by Chen et al. (2002) can be applied to clinics by raising Ron-specific antibodies. O'Toole et al. (2006) conducted an antibody phage display library to generate a human IgG1 antibody IMC-41A10 that binds with high affinity to RON and effectively blocks interaction with its ligand, macrophage-stimulating protein. They found IMC-41A10 to be a potent inhibitor of receptor and downstream signaling, cell migration, and tumorigenesis. It antagonized MSP-induced phosphorylation of RON, MAPK, and AKT in several cancer cell lines. In NCI-H292 lung cancer xenograft tumor models, IMC-41A10 inhibited tumor growth by 50% to 60% as a single agent. This antibody should be tested
Recent strategies showed the importance of aberrant promoter methylation in lung cancer development, such a
Acknowledgements
K. Inoue has been supported by NIH/NCI 5R01CA106314, ACS RSG-07-207-01-MGO, and by WFUCCC Director’s Challenge Award #20595. D. Maglic has been supported by DOD pre-doctoral fellowship BC100907. We thank K. Klein for editorial assistance.
References
- 1.
Siegel R, Naishadham D, Jemal A. Cancer statistics, 2012. CA Cancer J Clin 2012;62:10-29. - 2.
Centers for Disease Control and Prevention (CDC). Racial/Ethnic disparities and geographic differences in lung cancer incidence --- 38 States and the District of Columbia, 1998-2006. MMWR Morb Mortal Wkly Rep 2010;59:1434-8. - 3.
Wisnivesky JP, McGinn T, Henschke C, Hebert P, Iannuzzi MC, Halm EA. Ethnic disparities in the treatment of stage I non-small cell lung cancer. Am J Respir Crit Care Med 2005;171:1158-63. - 4.
Swierzewski III, SJ. Lung Cancer Environmental Risk Factors. 1999. http://www.healthcommunities.com/lung-cancer/environmental.shtml - 5.
Menon P. Lung Cancer: Delayed Diagnosis Among Non-Smokers. 2012. http://trialx.com/curetalk/2012/06/lung-cancer-delayed-diagnosis-among-non-smokers/ - 6.
Brambilla C, Fievet F, Jeanmart M, et al . Early detection of lung cancer: role of biomarkers.Eur Respir J Suppl 2003;39:36s-44s. - 7.
Yeung SC, Habra MA, Thosani SN. Lung cancer-induced paraneoplastic syndromes. Curr Opin Pulm Med 2011;17:260-8. - 8.
Moran CA. Pulmonary adenocarcinoma: The expanding spectrum of histologic variants. Arch Pathol Lab Med 2006;130:958-62. - 9.
Schiller JH. Current standards of care in small-cell and non-small-cell lung cancer. Oncology 2001;61, Suppl 1:3-13. - 10.
Travis WD. Pathology of lung cancer. Clin Chest Med 2002;23,65-81. - 11.
Zochbauer-Muller S, Gazdar AF, and Minna JD. Molecular pathogenesis of lung cancer. Ann Rev Physiol 2002;64,681-708. - 12.
Fong KM, Sekido Y, Gazdar AF, and Minna JD. Lung cancer. 9: Molecular biology of lung cancer: Clinical implications. Thorax 2003;58:892-900. - 13.
Meuwissen R and Berns A. Mouse models for human lung cancer. Genes Dev 2005;19:643-64. - 14.
Worden FP, Kalemkerian GP. Therapeutic advances in small cell lung cancer. Expert Opin Investig Drugs 2000;9:565-79. - 15.
Wakamatsu N, Devereux TR, Hong HH, et al . Overview of the molecular carcinogenesis of mouse lung tumor models of human lung cancer.Toxicol Pathol 2007;35:75-80. - 16.
Shimkin MB, Stoner GD. Lung tumors in mice: application to carcinogenesis bioassay. Adv Cancer Res 1975;21:1-58. - 17.
Pfeifer GP, Denissenko MF, Olivier M, et al . Tobacco smoke carcinogens, DNA damage and p53 mutations in smoking-associated cancers.Oncogene 2002;21:7435-51. - 18.
Sato M, Shames DS, Gazdar AF, et al . A translational view of the molecular pathogenesis of lung cancer.J Thorac Oncol 2007;2:327-43. - 19.
Malkinson AM. Primary lung tumors in mice as an aid for understanding, preventing, and treating human AdCA of the lung . Lung Cancer 2001;32:265-79. - 20.
DeMayo FJ, Finegold MJ, Hansen TN, et al . Expression of SV40 T antigen under control of rabbit uteroglobin promoter in transgenic mice.Am J Physiol 1991;261:L70-6. - 21.
Sandmoller A, Halter R, Gomez-La-Hoz E, et al . The uteroglobin promoter targets expression of the SV40 T antigen to a variety of secretory epithelial cells in transgenic mice.Oncogene 1994;9:2805-15. - 22.
Wikenheiser KA, Clark JC, Linnoila RI, et al . Simian virus 40 large T antigen directed by transcriptional elements of the human surfactant protein C gene produces pulmonary AdCAs in transgenic mice.Cancer Res 1992;52:5342-52. - 23.
Wikenheiser KA, Whitsett JA. Tumor progression and cellular differentiation of pulmonary AdCAs in SV40 large T antigen transgenic mice. Am J Respir Cell Mol Biol 1997;16:713-23. - 24.
Geick A, Redecker P, Ehrhardt A, et al. Uteroglobin promoter-targeted c-MYC expression in transgenic mice cause hyperplasia of Clara cells and malignant transformation of T-lymphoblasts and tubular epithelial cells.Transgenic Res 2001;10:501-11. - 25.
Ehrhardt A, Bartels T, Geick A, Klocke R, Paul D, Halter R. Development of pulmonary bronchiolo-alveolar AdCAs in transgenic mice overexpressing murine c-myc and epidermal growth factor in alveolar type II pneumocytes. Br J Cancer 2001;84:813-8. - 26.
Sunday ME, Haley KJ, Sikorski K, et al . Calcitonin driven v-Ha-ras induces multilineage pulmonary epithelial hyperplasias and neoplasms.Oncogene 1999;18:36-47. - 27.
Mallakin A, Sugiyama T, Taneja P, et al . Mutually exclusive inactivation of DMP1 and ARF/p53 in lung cancer.Cancer Cell 2007;12:381-94. - 28.
Morris GF, Hoyle GW, Athas GB, et al . Lung-specific expression in mice of a dominant negative mutant form of the p53 tumor suppressor protein.J La State Med Soc 1998;150:179-85. - 29.
Tchou-Wong KM, Jiang Y, Yee H, et al. Lung-specific expression of dominant-negative mutant p53 in transgenic mice increases spontaneous and benzo(a)pyrene-induced lung cancer.Am J Respir Cell Mol Biol 2002;27:186-93. - 30.
Chen YQ, Zhou YQ, Fu LH, Wang D, Wang MH. Multiple pulmonary adenomas in the lung of transgenic mice overexpressing the RON receptor tyrosine kinase. Recepteur d'origine nantais. Carcinogenesis 2002;23:1811-9. - 31.
Sekido Y, Fong KM, Minna JD. Molecular genetics of lung cancer. Annu Rev Med 2003;54:73-87. - 32.
Jacks T, Fazeli A, Schmitt EM, et al . Effects of an Rb mutation in the mouse.Nature 1992;359:295-300. - 33.
Meuwissen R, Berns A. Mouse models for human lung cancer. Genes Dev 2005;19:643-64. - 34.
Olive KP, Tuveson DA, Ruhe ZC, et al . Mutant p53 gain of function in two mouse models of Li-Fraumeni syndrome.Cell 2004;119:847-60. - 35.
Lang GA, Iwakuma T, Suh YA, et al . Gain of function of a p53 hot spot mutation in a mouse model of Li-Fraumeni syndrome.Cell 2004;119:861-72. - 36.
Smith AJ, Xian J, Richardson M, et al . Cre-loxP chromosome engineering of a targeted deletion in the mouse corresponding to the 3p21.3 region of homozygous loss in human tumors.Oncogene 2002;21:4521-9. - 37.
Tommasi S, Dammann R, Zhang Z, et al . Tumor susceptibility of Rassf1a knockout mice.Cancer Res 2005;65:92–8. - 38.
Zanesi N, Mancini R, Sevignani C, et al . Lung cancer susceptibility in Fhit-deficient mice is increased by Vhl haploinsufficiency.Cancer Res 2005;65:6576-82. - 39.
Johnson L, Mercer K, Greenbaum D, et al . Somatic activation of the K-ras oncogene causes early onset lung cancer in mice.Nature 2001;410:1111-6. - 40.
Hirai H, Sherr CJ. Interaction of D-type cyclins with a novel myb-like transcription factor, DMP1. Mol Cell Biol 1996;16:6457-67. - 41.
Inoue K, Sherr CJ. Gene expression and cell cycle arrest mediated by transcription factor DMP1 is antagonized by D-type cyclins through a cyclin-dependent-kinase-independent mechanism. Mol Cell Biol 1998;18:1590-600. - 42.
Inoue K, Mallakin A, and Frazier DP. Dmp1 and tumor suppression. Oncogene 2007;26:4329-35. Review. - 43.
Sugiyama T, Frazier DP, Taneja P, et al . Signal transduction involving the Dmp1 transcription factor and its alteration in human cancer.Clinical Medicine Insights: Oncology 2008a;2:209-19. - 44.
Inoue K, Roussel MF, and Sherr CJ. Induction of ARF tumor suppressor gene expression and cell cycle arrest by transcription factor DMP1. Proc Natl Acad Sci USA 1999;96:3993-8. - 45.
Sreeramaneni R, Chaudhry A, McMahon M, Sherr CJ, and Inoue K. Ras-Raf-Arf signaling critically depends on the Dmp1 transcription factor. Mol Cell Biol 2005;25:220-32. - 46.
Inoue K, Wen R, Rehg JE, Adachi M, Cleveland JL, Roussel MF, and Sherr CJ. Functional loss of the ARF transcriptional activator DMP1 facilitates cell immortalization, ras transformation, and tumorigenesis. Genes Dev 2000;14:1797-809. - 47.
Inoue K, Zindy F, Randle DH, Rehg JE, and Sherr CJ. Dmp1 is haplo-insufficient for tumor suppression and modifies the frequencies of Arf and p53 mutations in Myc-induced lymphomas. Genes Dev 2001;15:2934-9. - 48.
Mallakin A, Sugiyama T, Taneja P, et al . Mutually exclusive inactivation of DMP1 and ARF/p53 in lung cancer.Cancer Cell 2007;12:381-94. - 49.
Sugiyama T, Frazier DP, Taneja P, et al . The role of Dmp1 and its future in lung cancer diagnostics.Expert Rev Mol Diagn 2008b;8:435-48. - 50.
Sweet-Cordero A, Mukherjee S, Subramanian A, et al . An oncogenic KRAS2 expression signature identified by cross-species gene-expression analysis.Nat Genet 2005;37:48-55. - 51.
Jackson EL, Willis N, Mercer K, et al . Analysis of lung tumor initiation and progression using conditional expression of oncogenic K-ras.Genes Dev 2001;15:3243-8. - 52.
Jackson EL, Olive KP, Tuveson DA, Bronson R, Crowley D, Brown M, and Jacks T. The differential effects of mutant p53 alleles on advanced murine lung cancer. Cancer Res 2005;65:10280-8. - 53.
Ji H, Houghton AM, Mariani TJ, et al. K-ras activation generates an inflammatory response in lung tumors.Oncogene 2006;25:2105-12. - 54.
Jonkers J, Berns A. Conditional mouse models of sporadic cancer. Nat Rev Cancer 2002;2:251-65. - 55.
Lewandoski M. Conditional control of gene expression in the mouse. Nat Rev Genet 2001;2:743-55. - 56.
Gossen M, Bujard H. Tight control of gene expression in mammalian cells by tet-responsive promoters. Proc Natl Acad Sci USA 1992;89:5547-51. - 57.
Perl AK, Tichelaar JW, Whitsett JA. Conditional gene expression in the respiratory epithelium of the mouse. Transgenic Res 2002;11:21-9. - 58.
Floyd HS, Farnsworth CL, Kock ND, et al . Conditional expression of the mutant Ki-rasG12C allele results in formation of benign lung adenomas: development of a novel mouse lung tumor model.Carcinogenesis 2005;26:2196-206. - 59.
Tichelaar JW, Lu W, Whitsett JA. Conditional expression of fibroblast growth factor-7 in the developing and mature lung. J Biol Chem 2000;275:11858–64. - 60.
Fisher GH, Wellen SL, Klimstra D, et al . Induction and apoptotic regression of lung adenocarcinomas by regulation of a K-Ras transgene in the presence and absence of tumor suppressor genes.Genes Dev 2001;15:3249-62. - 61.
Dutt A, Wong KK. Novel agents in the treatment of lung cancer: advances in EGFR-targeted agents: mouse models of lung cancer. Clin Cancer Res 2006;12:4396s-402s. - 62.
Jackson EL, Willis N, Mercer K, et al . Analysis of lung tumor initiation and progression using conditional expression of oncogenic K-ras.Genes Dev 2001;15:3243-8. - 63.
Meuwissen R, Linn SC, van der Vaulk M, et al . Mouse model for lung tumorigenesis through Cre/lox controlled sporadic activation of the K-Ras oncogene.Oncogene 2001;20:6551–58. - 64.
Guerra C, Mijimolle N, Dhawahir A, et al . Tumor induction by an endogenous K-ras oncogene is highly dependent on cellular context.Cancer Cell 2003;4:111–120. - 65.
Ji H, Wang Z, Perera SA, et al . Mutations in BRAF and KRAS converge on activation of the mitogen-activated protein kinase pathway in lung cancer mouse models.Cancer Res 2007;67:4933-9. - 66.
Davies H, Bignell GR, Cox C, et al . Mutations of the BRAF gene in human cancer.Nature 2002;417:949-54. - 67.
Mercer KE, Pritchard CA. Raf proteins and cancer: B-Raf is identified as a mutational target. Biochim Biophys Acta 2003;1653:25-40. Review. - 68.
Dankort D, Filenova E, Collado M, Serrano M, Jones K, McMahon M. A new mouse model to explore the initiation, progression, and therapy of BRAFV600E-induced lung tumors. Genes Dev 2007;21:379-84. - 69.
Blasco RB, Francoz S, Santamaría D, et al . c-Raf, but not B-Raf, is essential for development of K-Ras oncogene-driven non-small cell lung carcinoma.Cancer Cell 2011;19:652-63. - 70.
Shaw AT, Meissner A, Dowdle JA, et al . Sprouty-2 regulates oncogenic K-ras in lung development and tumorigenesis.Genes Dev 2007;21:694-707. - 71.
Cho HC, Lai CY, Shao LE, Yu J. Identification of tumorigenic cells in Kras(G12D)-induced lung AdCA. Cancer Res 2011;71:7250-8. - 72.
Samuels Y, Velculescu VE. Oncogenic mutations of PIK3CA in human cancers. Cell Cycle 2004;3:1221-4. - 73.
Wojtalla A, Arcaro A. Targeting phosphoinositide 3-kinase signalling in lung cancer. Critical Reviews in Oncology/Hematology 2011;80:278-290. - 74.
Angulo B, Suarez-Gauthier A, Lopez-Rios F, et al . Expression signatures in lung cancer reveal a profile for EGFR-mutant tumors and identify selective PIK3CA overexpression by gene amplification.J Pathol 2008;214:347-56. - 75.
Engelman JA, Chen L, Tan X, et al . Effective use of PI3K and MEK inhibitors to treat mutant Kras G12D and PIK3CA H1047R murine lung cancers.Nat Med 2008;14:1351-6. - 76.
Gupta S, Ramjaun AR, Haiko P, et al . Binding of ras to phosphoinositide 3-kinase p110alpha is required for ras-driven tumorigenesis in mice.Cell 2007;129:957-68. - 77.
Mack NA, Whalley HJ, Castillo-Lluva S, Malliri A. The diverse roles of Rac signaling in tumorigenesis. Cell Cycle 2011;10:1571-81. - 78.
Kissil JL, Walmsley MJ, Hanlon L, et al . Requirement for Rac1 in a K-ras induced lung cancer in the mouse.Cancer Res 2007;67:8089-94. - 79.
Stella GM, Luisetti M, Inghilleri S, et al . Targeting EGFR in non-small-cell lung cancer: Lessons, experiences, strategies.Resp Med 2012;106,173-83. - 80.
Lynch TJ, Bell DW, Sordella R, et al . Activating mutations in the epidermal growth factor receptor underlying responsiveness of non-small-cell lung cancer to gefitinib.N Engl J Med 2004;350:2129-39. - 81.
Soria J-C, Mok TS, Cappuzzo F, et al . EGFR-mutated oncogene-addicted non-small cell lung cancer: Current trends and future prospects.Cancer Treat Rev 2012;38,416-30. - 82.
Ji H, Zhao X, Yuza Y, et al . Epidermal growth factor receptor variant III mutations in lung tumorigenesis and sensitivity to tyrosine kinase inhibitors.Proc Natl Acad Sci USA . 2006a;103:7817-22. Epub 2006 May 3. - 83.
Ji H, Li D, Chen L, et al . The impact of human EGFR kinase domain mutations on lung tumorigenesis and in vivo sensitivity to EGFR-targeted therapies.Cancer Cell 2006b;9:485-95. - 84.
Politi K, Zakowski MF, Fan PD, et al . Lung adenocarcinomas induced in mice by mutant EGF receptors found in human lung cancers respond to a tyrosine kinase inhibitor or to down-regulation of the receptors.Genes Dev 2006;20:1496-510. - 85.
Li D, Shimamura T, Ji H, Chen L et al . Bronchial and Peripheral Murine Lung Carcinomas Induced by T790M-L858R Mutant EGFR Respond to HKI-272 and Rapamycin Combination Therapy.Cancer Cell 2007;12:81-93. - 86.
Hu Y, Bandla S, Godfrey TE, Tan D, et al . HER2 amplification, overexpression and score criteria in esophageal adenocarcinoma.Mod Pathol 2011;24:899-907. - 87.
Taneja P, Maglic D, Kai F, et al . Critical role of Dmp1 in HER2/neu-p53 signaling and breast carcinogenesis.Cancer Res 70: 9084-94, 2010. - 88.
Hirsch FR, Varella-Garcia M, Cappuzzo F. Predictive value of EGFR and HER2 overexpression in advanced non-small-cell lung cancer. Oncogene 2009;28 Suppl 1:S32-7. - 89.
Swanton C, Futreal A, Eisen T. Her2-targeted therapies in non-small cell lung cancer. Clin Cancer Res 2006;12(14 Pt 2):4377s-83s. - 90.
Grob TJ, Kannengiesser I, Tsourlakis MC, et al . Heterogeneity of ERBB2 amplification in adenocarcinoma, squamous cell carcinoma and large cell undifferentiated carcinoma of the lung.Mod Pathol 2012 Aug 17. doi: 10.1038/modpathol.2012.125. [Epub ahead of print] - 91.
Pinder. Lesser Known Lung Cancer Mutations Part 1: HER2, a promising therapeutic target? http://cancergrace.org/lung/2011/03/19/her2-by-m/ - 92.
Meuwissen R and Berns A. Mouse models for human lung cancer. Genes Dev 2005;19,643-64. - 93.
Sherr CJ. Cancer cell cycles. Science 1996;274:1672-7. Review. - 94.
Sherr CJ. Principles of tumor suppression. Cell 2004;116:235-46. Review. - 95.
Jiang W, Kahn SM, Zhou P, et al . Overexpression of cyclin D1 in rat fibroblasts causes abnormalities in growth control, cell cycle progression and gene expression.Oncogene 1993;8:3447-57. - 96.
Gautschi O, Ratschiller D, Gugger M, Betticher DC, Heighway J. Cyclin D1 in non-small cell lung cancer: A key driver of malignant transformation. Lung Cancer 2007;55:1-14. - 97.
Wang TC, Cardiff RD, Zukerberg L, et al . Mammary hyperplasia and carcinoma in MMTV-cyclin D1 transgenic mice.Nature 1994 ;369:669-71. - 98.
Kim ES, Lee JJ, Wistuba II. Cotargeting Cyclin D1 Starts a New Chapter in Lung Cancer Prevention and Therapy. Cancer Prevention Research 2011;4:779-82. - 99.
Diehl JA, Zindy F, Sherr CJ. Inhibition of cyclin D1 phosphorylation on threonine-286 prevents its rapid degradation via the ubiquitin-proteasome pathway. Genes Dev 1997;11:957-72. - 100.
Dragnev KH, Ma T, Cyrus J, et al . Bexarotene Plus Erlotinib Suppress Lung Carcinogenesis Independent of KRAS Mutations in Two Clinical Trials and Transgenic Models.Cancer Prev Res 2011;4:818-28. - 101.
Yanagi S, Kishimoto H, Kawahara K, et al . Pten controls lung morphogenesis, bronchioalveolar stem cells, and onset of lung adenocarcinomas in mice.J Clin Invest 2007;117:2929–40. - 102.
Inoue K, Kulik G, Fry EA, Zhu S, and Maglic D. Recent progress in mouse models for tumor suppressor genes and its implications in human cancer (review). Clinical Medicine Insights: Oncology, submitted (2012). - 103.
Iwanaga K, Yang Y, Raso MG, et al . Pten inactivation accelerates oncogenic K-ras-initiated tumorigenesis in a mouse model of lung cancer.Cancer Res 2008;68:1119-27. - 104.
Yanagi S, Kishimoto H, Kawahara K, et al . Pten controls lung morphogenesis, bronchioalveolar stem cells, and onset of lung adenocarcinomas in mice.J Clin Invest 2007;117:2929–40. - 105.
Iwanaga K, Yang Y, Raso MG, et al . Pten inactivation accelerates oncogenic K-ras-initiated tumorigenesis in a mouse model of lung cancer.Cancer Res 2008;68:1119-27. - 106.
Giardiello FM, Brensinger JD, Tersmette AC, et al . Very high risk of cancer in familial Peutz-Jeghers syndrome.Gastroenterology 2000;119:1447–53. - 107.
Sanchez-Cespedes M, Parrella P, Esteller M, et al . Inactivation of LKB1/STK11 is a common event in AdCAs of the lung.Cancer Res 2002;62:3659–62. - 108.
Wei C, Amos CI, Stephens LC, et al . Mutation of Lkb1 and p53 genes exert a cooperative effect on tumorigenesis.Cancer Res 2005;65:11297-303. - 109.
Shaw RJ, Kosmatka M, Bardeesy N, et a l. The tumor suppressor LKB1 kinase directly activates AMP-activated kinase and regulates apoptosis in response to energy stress.Proc Natl Acad Sci USA 2004;101:3329-35. - 110.
Makowski L, Hayes DN. Role of LKB1 in lung cancer development. Br J Cancer 2008;99:683-8. - 111.
Sanchez-Cespedes M. A role for LKB1 gene in human cancer beyond the Peutz-Jeghers syndrome. Oncogene 2007;26:7825-32. - 112.
Matsumoto S, Iwakawa R, Takahashi K, et al . Prevalence and specificity of LKB1 genetic alterations in lung cancers.Oncogene 2007;26:5911-8. - 113.
Ji H, Ramsey MR, Hayes DN, et al . LKB1 modulates lung cancer differentiation and metastasis.Nature 2007;448:807-10. - 114.
Shah U, Sharpless NE, Hayes DN. LKB1 and lung cancer: more than the usual suspects. Cancer Res 2008;68:3562-65. - 115.
Ghaffar H, Sahin F, Sanchez-Cepedes M, et al . LKB1 protein expression in the evolution of glandular neoplasia of the lung.Clin Cancer Res 2003;9:2998-3003. - 116.
Chen Z, Cheng K, Walton Z, et al . A murine lung cancer co-clinical trial identifies genetic modifiers of therapeutic response.Nature 2012;483:613-7. - 117.
Hayashita Y, Osada H, Tatematsu Y, et al . A polycistronic microRNA cluster, miR-17-92, is overexpressed in human lung cancers and enhances cell proliferation.Cancer Res 2005;65:9628-32. - 118.
Kumar MS, Lu J, Mercer KL, et al . Impaired microRNA processing enhances cellular transformation and tumorigenesis.Nat Genet 2007;39:673-7. - 119.
Johnson SM, Grosshans H, Shingara J, et al . RAS is regulated by the let-7 microRNA family.Cell 2005;120:635-47. - 120.
Esquela-Kerscher A, Trang P, Wiggins JF, et al . The let-7 microRNA reduces tumor growth in mouse models of lung cancer.Cell Cycle 2008;7:759-64. - 121.
Kumar MS, Erkeland SJ, Pester RE, et al. Suppression of non-small cell lung tumor development by the let-7 microRNA family.Proc Natl Acad Sci USA 2008;105:3903-8. - 122.
Volinia S, Calin GA, Liu CG, et al. A microRNA expression signature of human solid tumors defines cancer gene targets. Proc Natl Acad Sci USA 2006;103:2257-61. - 123.
Chan JA, Krichevsky AM, Kosik KS. MicroRNA-21 is an antiapoptotic factor in human glioblastoma cells. Cancer Res 2005;65:6029-33. - 124.
Si ML, Zhu S, Wu H, Lu Z, Wu F, Mo YY. miR-21-mediated tumor growth. Oncogene 2007;26:2799-803. - 125.
Zhu S, Wu H, Wu F, Nie D, Sheng S, Mo YY. MicroRNA-21 targets tumor suppressor genes in invasion and metastasis. Cell Res 2008;18:350-9. - 126.
Wang P, Zou F, Zhang X, et al . microRNA-21 negatively regulates Cdc25A and cell cycle progression in colon cancer cells.Cancer Res 2009;69:8157-65. - 127.
Hatley ME, Patrick DM, Garcia MR, et al. Modulation of K-Ras-dependent lung tumorigenesis by MicroRNA-21.Cancer Cell 2010;18:282-93. - 128.
Hennessey PT, Sanford T, Choudhary A, et al. Serum microRNA biomarkers for detection of non-small cell lung cancer. PLoS One 2012;7:e32307. - 129.
Hammerman PS, Lawrence MS, and Voet D et al. The Cancer Genome Atlas Research Network. Comprehensive genomic characterization of squamous cell lung cancers.Nature 2012 Sep 9. doi: 10.1038/nature11404. [Epub ahead of print]. - 130.
Brambilla E, Lantuejoul S, Sturm N. Divergent differentiation in neuroendocrine lung tumors. Semin Diagn Pathol 2000;17:138–48. - 131.
Wistuba II, Mao L, Gazdar AF. Smoking molecular damage in bronchial epithelium. Oncogene 2002;21:7298–306. - 132.
Wistuba II, Gazdar AF. Characteristic genetic alterations in lung cancer. Methods Mol Med 2003;74:3-28. - 133.
Jetten AM, Nervi C, Vollberg TM. Control of squamous differentiation in tracheobronchial and epidermal epithelial cells: role of retinoids. J Natl Cancer Inst Monogr 1992;320:93-100. - 134.
Nettesheim P, Hammons AS. Induction of squamous cell carcinoma in the respiratory tract of mice. J Natl Cancer Inst 1971;47:697-701. - 135.
Rehm S, Lijinsky W, Singh G, et al . Mouse bronchiolar cell carcinogenesis. Histologic characterization and expression of Clara cell antigen in lesions induced by N-nitrosobis-(2-chloroethyl) ureas.Am J Pathol 1991;139:413-22. - 136.
Wang Y, Zhang Z, Yan Y, et al . A chemically induced model for squamous cell carcinoma of the lung in mice: histopathology and strain susceptibility.Cancer Res 2004;64:1647-54. - 137.
Dakir EL, Feigenbaum L, Linnoila RI. Constitutive expression of human keratin 14 gene in mouse lung induces premalignant lesions and squamous differentiation. Carcinogenesis 2008;29:2377-84. - 138.
Ji H, Ramsey MR, Hayes DN, et al . LKB1 modulates lung cancer differentiation and metastasis.Nature 2007;448:807-10. - 139.
Fisher GH, Wellen SL, Klimstra D, et al . Induction and apoptotic regression of lung adenocarcinomas by regulation of a K-Ras transgene in the presence and absence of tumor suppressor genes.Genes Dev 2001;15:3249-62. - 140.
Politi K, Zakowski MF, Fan PD, et al . Lung adenocarcinomas induced in mice by mutant EGF receptors found in human lung cancers respond to a tyrosine kinase inhibitor or to down-regulation of the receptors.Genes Dev 2006;20:1496-510. - 141.
Ji H, Li D, Chen L, et al . The impact of human EGFR kinase domain mutations on lung tumorigenesis and in vivo sensitivity to EGFR-targeted therapies.Cancer Cell 2006a;9:485-95. - 142.
Ji H, Zhao X, Yuza Y, et al . Epidermal growth factor receptor variant III mutations in lung tumorigenesis and sensitivity to tyrosine kinase inhibitors.Proc Natl Acad Sci USA 2006b;103:7817-22. - 143.
Engelman JA, Chen L, Tan X, et al . Effective use of PI3K and MEK inhibitors to treat mutant Kras G12D and PIK3CA H1047R murine lung cancers.Nat Med 2008;14:1351-6. - 144.
Mahgoub N, Taylor BR, Gratiot M, et al . In vitro and in vivo effects of a farnesyltransferase inhibitor on Nf1-deficient hematopoietic cells.Blood 1999;94:2469-76. - 145.
Omer CA, Chen Z, Diehl RE, et al . Mouse mammary tumor virus-Ki-rasB transgenic mice develop mammary carcinomas that can be growth-inhibited by a farnesyl:protein transferase inhibitor.Cancer Res 2000;60:2680-8. - 146.
To MD, Wong CE, Karnezis AN, et al . Kras regulatory elements and exon 4A determine mutation specificity in lung cancer.Nat Genet 2008;40:1240-4. - 147.
Contag CH, Jenkins D, Contag PR, et al . Use of reporter genes for optical measurements of neoplastic disease in vivo.Neoplasia 2000;2:41-52. - 148.
Hadjantonakis AK, Dickinson ME, Fraser SE, et al . Technicolour transgenics: imaging tools for functional genomics in the mouse.Nature Rev Genet 2003;4:613-25. - 149.
Jackson EL, Willis N, Mercer K, et al . Analysis of lung tumor initiation and progression using conditional expression of oncogenic K-ras.Genes Dev 2001;15:3243-8. - 150.
Chen YQ, Zhou YQ, Fu LH, Wang D, Wang MH. Multiple pulmonary adenomas in the lung of transgenic mice overexpressing the RON receptor tyrosine kinase. Recepteur d'origine nantais. Carcinogenesis 2002;23:1811-9. - 151.
O'Toole JM, Rabenau KE, Burns K, et al . Therapeutic implications of a human neutralizing antibody to the macrophage-stimulating protein receptor tyrosine kinase (RON), a c-MET family member.Cancer Res 2006;66:9162-70. - 152.
Shames DS, Girard L, Gao B, et al . A genome-wide screen for promoter methylation in lung cancer identifies novel methylation markers for multiple malignancies.PLoS Med 2006; 3:e486. - 153.
Shacter E, Weitzman SA. Chronic inflammation and cancer. Oncology (Williston Park) . 2002;16:217-26, 229; discussion 230-2. - 154.
Vaid M, Floros J. Surfactant protein DNA methylation: a new entrant in the field of lung cancer diagnostics? Oncol Rep 2009;21:3-11. - 155.
Korfhagen TR, Bruno MD, Ross GF, et al . Altered surfactant function and structure in SP-A gene targeted mice.Proc Natl Acad Sci USA 1996;93:9594-9. - 156.
Botas C, Poulain F, Akiyama J, et al . Altered surfactant homeostasis and alveolar type II cell morphology in mice lacking surfactant protein D.Proc Natl Acad Sci USA 1998;95:11869–74.