Neuroendocrine Lung Cancer Mouse Models: An Overview

Nonviral CRISPR/Cas9 mutagenesis for streamlined generation of mouse lung cancer models

Functional analysis in mouse models is necessary to establish the involvement of a set of genetic variations in tumor development. A modeling platform to facilitate and cost-effectively analyze the role of multiple genes in carcinogenesis would be valuable. Here, we present an innovative strategy for lung mutagenesis using CRISPR/Cas9 ribonucleoproteins delivered via cationic polymers. This approach allows the simultaneous inactivation of multiple genes. We validate the effectiveness of this system by targeting a group of tumor suppressor genes, specifically Rb1, Rbl1, Pten, and Trp53, which were chosen for their potential to cause lung tumors, namely small cell lung carcinoma (SCLC). Tumors with histologic and transcriptomic features of human SCLC emerged after intratracheal administration of CRISPR/polymer nanoparticles. These tumors carried loss-of-function mutations in all four tumor suppressor genes at the targeted positions. These findings were reproduced in two different pure genetic backgrounds. We provide a proof of principle for simplified modeling of lung tumorigenesis to facilitate functional testing of potential cancer-related genes.

Druggable growth dependencies and tumor evolution analysis in patient-derived organoids of neuroendocrine neoplasms from multiple body sites

Neuroendocrine neoplasms (NENs) comprise well-differentiated neuroendocrine tumors (NETs) and poorly differentiated neuroendocrine carcinomas (NECs). Treatment options for patients with NENs are limited, in part due to lack of accurate models. We establish patient-derived tumor organoids (PDTOs) from pulmonary NETs and derive PDTOs from an understudied subtype of NEC, large cell neuroendocrine carcinoma (LCNEC), arising from multiple body sites. PDTOs maintain the gene expression patterns, intra-tumoral heterogeneity, and evolutionary processes of parental tumors. Through hypothesis-driven drug sensitivity analyses, we identify ASCL1 as a potential biomarker for response of LCNEC to treatment with BCL-2 inhibitors. Additionally, we discover a dependency on EGF in pulmonary NET PDTOs. Consistent with these findings, we find that, in an independent cohort, approximately 50% of pulmonary NETs express EGFR. This study identifies an actionable vulnerability for a subset of pulmonary NETs, emphasizing the utility of these PDTO models.

Novel Mouse Cell Lines and In Vivo Models for Human High-Grade Neuroendocrine Lung Carcinoma, Small Cell Lung Carcinoma (SCLC), and Large Cell Neuroendocrine Carcinoma (LCNEC)

There is a clear need to expand the toolkit of adequate mouse models and cell lines available for preclinical studies of high-grade neuroendocrine lung carcinoma (small cell lung carcinoma (SCLC) and large cell neuroendocrine carcinoma (LCNEC)). SCLC and LCNEC are two highly aggressive tumor types with dismal prognoses and few therapeutic options. Currently, there is an extreme paucity of material, particularly in the case of LCNEC. Given the lack of murine cell lines and transplant models of LCNEC, the need is imperative. In this study, we generated and examined new models of LCNEC and SCLC transplantable cell lines derived from our previously developed primary mouse LCNEC and SCLC tumors. RNA-seq analysis demonstrated that our cell lines and syngeneic tumors maintained the transcriptome program from the original transgenic primary tumor and displayed strong similarities to human SCLC or LCNEC. Importantly, the SCLC transplanted cell lines showed the ability to metastasize and mimic this characteristic of the human condition. In summary, we generated mouse cell line tools that allow further basic and translational research as well as preclinical testing of new treatment strategies for SCLC and LCNEC. These tools retain important features of their human counterparts and address the lack of LCNEC disease models.

Pten and p53 Loss in the Mouse Lung Causes Adenocarcinoma and Sarcomatoid Carcinoma

Simple Summary

Lung cancer is the world leading cause of cancer death. Therefore, a better understanding of the disease is needed to improve patient survival. In this work, we have deleted the tumor suppressor genes Pten and Trp53 in adult mouse lungs to analyze its impact on tumor formation. Double mutant mice develop Adenocarcinoma and Pulmonary Sarcomatoid Carcinoma, two different types of Non-Small Cell Carcinoma whose biological relationships are a matter of debate. The former is very common, with various models described and some therapeutic options. The latter is very rare with very poor prognosis, no effective treatment and lack of models reported so far. Interestingly, this study reports the first mouse model of pulmonary sarcomatoid carcinoma available for preclinical research.

Abstract

Lung cancer remains the leading cause of cancer deaths worldwide. Among the Non-Small Cell Carcinoma (NSCLC) category, Adenocarcinoma (ADC) represents the most common type, with different reported driver mutations, a bunch of models described and therapeutic options. Meanwhile, Pulmonary Sarcomatoid Carcinoma (PSC) is one of the rarest, with very poor outcomes, scarce availability of patient material, no effective therapies and no models available for preclinical research. Here, we describe that the combined deletion of Pten and Trp53 in the lungs of adult conditional mice leads to the development of both ADC and PSC irrespective of the lung targeted cell type after naphthalene induced airway epithelial regeneration. Although this model shows long latency periods and incomplete penetrance for tumor development, it is the first PSC mouse model reported so far, and sheds light on the relationships between ADC and PSC and their cells of origin. Moreover, human ADC show strong transcriptomic similarities to the mouse PSC, providing a link between both tumor types and the human ADC.

Modeling Lung Carcinoids with Zebrafish Tumor Xenograft

Lung carcinoids are neuroendocrine tumors that comprise well-differentiated typical (TCs) and atypical carcinoids (ACs). Preclinical models are indispensable for cancer drug screening since current therapies for advanced carcinoids are not curative. We aimed to develop a novel in vivo model of lung carcinoids based on the xenograft of lung TC (NCI-H835, UMC-11, and NCI-H727) and AC (NCI-H720) cell lines and patient-derived cell cultures in Tg(fli1a:EGFP)^y1 zebrafish embryos. We exploited this platform to test the anti-tumor activity of sulfatinib. The tumorigenic potential of TC and AC implanted cells was evaluated by the quantification of tumor-induced angiogenesis and tumor cell migration as early as 24 h post-injection (hpi). The characterization of tumor-induced angiogenesis was performed in vivo and in real time, coupling the tumor xenograft with selective plane illumination microscopy on implanted zebrafish embryos. TC-implanted cells displayed a higher pro-angiogenic potential compared to AC cells, which inversely showed a relevant migratory behavior within 48 hpi. Sulfatinib inhibited tumor-induced angiogenesis, without affecting tumor cell spread in both TC and AC implanted embryos. In conclusion, zebrafish embryos implanted with TC and AC cells faithfully recapitulate the tumor behavior of human lung carcinoids and appear to be a promising platform for drug screening.