EpCAM Targeted 3WJ RNA Nanoparticle Harboring Delta-5-desaturase siRNA Inhibited Lung Tumor Formation via COX-2 Catalyzed Dihomo-γ-linolenic acid Peroxidation

AbstractAlthough lung cancer is the leading cause of cancer-related deaths worldwide and KRAS is the most frequently mutated oncogene in lung cancer cases, the mechanism by which KRAS mutation drives lung cancer has not been fully elucidated. Here, we report that the expression levels of leukotriene B4 receptor-2 (BLT2) and its ligand-producing enzymes (5-LOX, 12-LOX) were highly increased by mutant KRAS and that BLT2 or 5-/12-LOX blockade attenuated KRAS-driven lung cell proliferation and production of interleukin-6 (IL-6), a principal proinflammatory mediator of lung cancer development. Next, we explored the roles of BLT2 and 5-/12-LOX in transgenic mice with lung-specific expression of mutant KRAS (KrasG12D) and observed that BLT2 or 5-/12-LOX inhibition decreased IL-6 production and tumor formation. To further determine whether BLT2 is involved in KRAS-driven lung tumor formation, we established a KrasG12D/BLT2-KO double-mutant mouse model. In the double-mutant mice, we observed significantly suppressed IL-6 production and lung tumor formation. Additionally, we observed high BLT2 expression in tissue samples from patients with KrasG12D-expressing lung adenocarcinoma, supporting the contributory role of BLT2 in KRAS-driven human lung cancer. Collectively, our results suggest that BLT2 is a potential contributor to KRAS-driven lung cancer and identify an attractive therapeutic target for KRAS-driven lung cancer.

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The Oncogenic Potential of a Mutant TP53 Gene Explored in Two Spontaneous Lung Cancer Mice Models

10.21203/rs.3.rs-22164/v1 ◽

2020 ◽

Author(s):

Julian Ramelow ◽

Christopher Brooks ◽

Li GaO ◽

Abeer A Almiman ◽

Terence M Williams ◽

...

Keyword(s):

Lung Cancer ◽

Mouse Models ◽

Human Lung ◽

Lung Tumor ◽

Mutant Gene ◽

Genetic Mutation ◽

Tumor Formation ◽

Human Lung Cancer ◽

Oncogenic Potential ◽

Age Related

Abstract BackgroundLung cancer is the number one cancer killer worldwide. A major impediment to progress in the lung cancer treatment field is the lack of realistic mouse models that replicate the complexity of human malignancy and immune contexture within the tumor microenvironment. Such models are urgently needed. Mutations of the tumor suppressor gene TP53 are among the most common alterations in human lung cancers.MethodsPreviously, we developed a line of lung cancer mouse model where mutant human TP53-273H is expressed in a lung specific manner in FVB/N background. To investigate whether the human TP53 mutant has a similar oncogenic potential when it is expressed in another strain of mouse, we crossed the FVB/N-SPC-TP53-273H mice to A/J strain and created A/J-SPC-TP53-273H transgenic mice. We then compared lung tumor formation between A/J-SPC-TP53-273H and FVB/N-SPC-TP53-273H.ResultsWe found the TP53-273H mutant gene has a similar oncogenic potential in lung tumor formation in both mice strains, although A/J strain mice have been found to be a highly susceptible strain in terms of carcinogen-induced lung cancer. Both transgenic lines survived more than 18 months and developed age related lung adenocarcinomas. With micro CT imaging, we found the FVB-SPC-TP53-273H mice survived more than 8 weeks after initial detection of lung cancer, providing a sufficient window for evaluating new anti-cancer agents.ConclusionsOncogenic potential of the most common genetic mutation, TP53-273H, in human lung cancer is unique when it is expressed in different strains of mice. Our mouse models are useful tools for testing novel immune check point inhibitors or other therapeutic strategies in treatment of lung cancer.

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