Primärtumor und MEF Zellisolation zu Lungenmetastasen Studieren

Summary

The goal of this protocol is to study breast tumorigenesis. With this technique, mouse mammary tumors are removed and primary cells are prepared from tumors. A lung extraction protocol is included for studying lung metastasis. Furthermore, another protocol for analyzing mouse embryonic fibroblasts from the mouse embryo is included.

Abstract

In breast tumorigenesis, the metastatic stage of the disease poses the greatest threat to the affected individual. Normal breast cells with altered genotypes now possess the ability to invade and survive in other tissues. In this protocol, mouse mammary tumors are removed and primary cells are prepared from tumors. The cells isolated from this procedure are then available for gene profiling experiments. For successful metastasis, these cells must be able to intravasate, survive in circulation, extravasate to distant organs, and survive in that new organ system. The lungs are the typical target of breast cancer metastasis. A set of genes have been discovered that mediates the selectivity of metastasis to the lung. Here we describe a method of studying lung metastasis from a genetically engineered mouse model.. Furthermore, another protocol for analyzing mouse embryonic fibroblasts (MEFs) from the mouse embryo is included. MEF cells from the same animal type provide a clue of non-cancer cell gene expression. Together, these techniques are useful in studying mouse mammary tumorigenesis, its associated signaling mechanisms and pathways of the abnormalities in embryos.

Introduction

Metastasis is the final step in the progression of breast cancer ¹. It involves a series of steps in which malignant cells are released from the primary tumor and disseminated to other organs ². The cells must be able to intravasate, survive in circulation, extravasate to distant organs, and survive in that new organ system ³. Each step in tumorigenesis is tightly controlled by cells through various genetic and epigenetic changes ⁴. To study the mechanisms of breast cancer tumorigenesis, mouse model systems have been utilized due to their short lifespan, small size and fast breeding time. Some major advantages of using mouse models in cancer research are the molecular and physiological similarities they share with humans ⁵.

Established mouse and human cell lines have been used extensively in breast cancer research. Although we can obtain some information about the steps in metastasis using these cells, genetically manipulated animal models with tumor suppressors/oncogenes will give far more information about tumor development and metastasis starting from the embryonic stage. Thus, with these mouse models, we can obtain genetic and developmental regulation of tumor growth. Furthermore, the tumor microenvironment also plays an important role in tumor cell gene expression and it can be difficult to mimic the same scenario with studies using established cell lines. Primary human mammary tumors can also be used to study mouse mammary tumorigenesis. The main disadvantage of using isolated breast tumors is that this newly implanted tumor does not have the mouse’s vasculature and lymphatic tissue. Whereas the genetic mouse model systems for studying mammary tumorigenesis will allow us to monitor the steps of metastasis, analyze the tumor microenvironment, and access to the entire body ⁵.

The overall goal of this protocol is to study breast tumorigenesis in mice. It is known that breast cancers typically metastasize to the brain, lung and bone. This protocol allows for the isolation of primary mammary tumor cells, as well as, studying breast cancer metastasis to the lung. Furthermore, another protocol for analyzing mouse embryonic fibroblasts (MEFs) from the mouse embryo is included. Together, these techniques are useful in studying mouse mammary tumorigenesis.

Protocol

Alle Maus-Experimente wurden in Übereinstimmung mit Protokollen von der Institutional Animal Care und Verwenden Committees (IACUC) von LSU School of Medicine genehmigt wurde. Alle Instrumente müssen vor der Dissektion autoklaviert werden. 1. Herstellung von primären Zellen aus Mausbrusttumoren Eine Maus-Modell, das genetisch mit dem Maus-Brusttumorvirus Polyoma Middle-T-Antigen (MMTV-PyMT transgenen Maus), das spontan entwickeln Tumore wie zuvor beschrieben 6 konstruiert wurde. …

Representative Results

Die Tumorprogression Stadium, in dem das Tier zu opfern, hängt von der jeweiligen Studie und IACUC Richtlinien. In 1A einer 100 Tage alte C57BL / 6-Maus mit der Maus-Mammatumorvirus Polyoma Middle-T-Antigen (MMTV-PyMT) wurde nach drei Monaten geopfert. Die Haut wurde von dem Bereich der Harnröhrenöffnung, um den Hals mit einer Schere geöffnet und die Haut wurde festgenagelt, um einfachen Zugang zu Organen, wie in 1B gezeigt, zu ermöglichen. Dies erlaubt einen einfachen Zugang zum T…

Discussion

Dieses Protokoll ist zur Isolierung von primären Zellen aus einer neuen Maus-Tumor. Lysate aus diesen Verfahren hergestellt werden, sind nützlich für die Protein-, DNA- und RNA-Analyse. Krebszellen aus dem primären Brusttumor metastasieren häufig zum Gehirn, Lunge und Knochen ^1. Eingeschlossen ist eine Technik, die zur Detektion von Lungenmetastasen zu extrahieren. Anfärben der Lunge mit einem Tintenfleck wird zur Visualisierung von Tumorknoten zu ermöglichen, wie in 2B zu sehen. Zur F…

Materials

DMEM	HyClone	SH30243.01	Store at 4 °C
0.05% Trypsin-EDTA	Life  technologies	25300-062	Store at – 20 °C
Collagenase Type IV	Sigma-Aldrich	C5138	Store at – 20 °C
Hyaluronidase	Sigma-Aldrich	H3506	Store at – 20 °C
Pen Strep	Life  technologies	15140-122	Store at 4 °C
Fetal Bovine Serum (FBS)	Gemini Bio-Products	100-106	Store at – 80 °C
Z-fix	ANATECH	#174	Store at room temperature
India Ink	Yasutomo		Store at room temperature
AERRANE (Isoflurane)	Baxter	NDC 10019-773-60	Store at room temperature
Ethanol	EMD	AX0441-3	Store at room temperature