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Journal Article

gene expression profiling; lung cancer; immunohistochemistry; Western blotting; in vivo imaging; moleuclar imaging; fluorescence molecular tomography

Using gene expression profiling, we identified cathepsin cysteine proteases as highly up-regulated genes in a mouse model of human lung adenocarcinoma. Overexpression of cathepsin proteases in these lung tumors was confirmed by immunohistochemistry and Western blotting. Therefore, an optical probe activated by cathepsin proteases was selected to detect murine lung tumors in vivo as small as 1 mm in diameter and spatially separated. We generated 3D maps of the fluorescence signal and fused them with anatomical computed tomography images to show a close correlation between fluorescence signal and tumor burden. By serially imaging the same mouse, optical imaging was used to follow tumor progression. This study demonstrates the capability for molecular imaging of a primary lung tumor by using endogenous proteases expressed by a tumor. It also highlights the feasibility of using gene expression profiling to identify molecular targets for imaging lung cancer.

Journal Article

Animals; Bioware; Breast Neoplasms; Disease Models, Animal; Female; Humans; Luciferases; Mammary Neoplasms, Animal; MDA-MB-231-D3H2LN cells; Mice; Mice, Nude; Neoplasm Metastasis; Plasmids; Transplantation, Heterologous; Tumor Cells, Cultured

INTRODUCTION Our goal was to generate xenograft mouse models of human breast cancer based on luciferase-expressing MDA-MB-231 tumor cells that would provide rapid mammary tumor growth; produce metastasis to clinically relevant tissues such as lymph nodes, lung, and bone; and permit sensitive in vivo detection of both primary and secondary tumor sites by bioluminescent imaging. METHOD Two clonal cell sublines of human MDA-MB-231 cells that stably expressed firefly luciferase were isolated following transfection of the parental cells with luciferase cDNA. Each subline was passaged once or twice in vivo to enhance primary tumor growth and to increase metastasis. The resulting luciferase-expressing D3H1 and D3H2LN cells were analyzed for long-term bioluminescent stability, primary tumor growth, and distal metastasis to lymph nodes, lungs, bone and soft tissues by bioluminescent imaging. Cells were injected into the mammary fat pad of nude and nude-beige mice or were delivered systemically via intracardiac injection. Metastasis was also evaluated by ex vivo imaging and histologic analysis postmortem. RESULTS The D3H1 and D3H2LN cell lines exhibited long-term stable luciferase expression for up to 4-6 months of accumulative tumor growth time in vivo. Bioluminescent imaging quantified primary mammary fat pad tumor development and detected early spontaneous lymph node metastasis in vivo. Increased frequency of spontaneous lymph node metastasis was observed with D3H2LN tumors as compared with D3H1 tumors. With postmortem ex vivo imaging, we detected additional lung micrometastasis in mice with D3H2LN mammary tumors. Subsequent histologic evaluation of tissue sections from lymph nodes and lung lobes confirmed spontaneous tumor metastasis at these sites. Following intracardiac injection of the MDA-MB-231-luc tumor cells, early metastasis to skeletal tissues, lymph nodes, brain and various visceral organs was detected. Weekly in vivo imaging data permitted longitudinal analysis of metastasis at multiple sites simultaneously. Ex vivo imaging data from sampled tissues verified both skeletal and multiple soft tissue tumor metastasis. CONCLUSION This study characterized two new bioluminescent MDA-MB-231-luc human breast carcinoma cell lines with enhanced tumor growth and widespread metastasis in mice. Their application to current xenograft models of breast cancer offers rapid and highly sensitive detection options for preclinical assessment of anticancer therapies in vivo.

Journal Article

Animals; Bioware; Bone Neoplasms; Cell Line, Tumor; Collagen; DNA-Binding Proteins; Drug Carriers; Gene Expression Regulation, Neoplastic; Gene Therapy; Humans; Luciferases; Male; Mice; PC-3M-luc; Phosphatidylinositol 3-Kinases; Prostatic Neoplasms; Reverse Transcriptase Polymerase Chain Reaction; RNA, Small Interfering; Transcription Factors

Silencing of gene expression by small interfering RNAs (siRNAs) is rapidly becoming a powerful tool for genetic analysis and represents a potential strategy for therapeutic product development. However, there are no reports of systemic delivery for siRNAs toward treatment of bone-metastatic cancer. Accordingly, we report here that i.v. injection of GL3 luciferase siRNA complexed with atelocollagen showed effective reduction of luciferase expression from bone-metastatic prostate tumor cells developed in mouse thorax, jaws, and/or legs. We also show that the siRNA/atelocollagen complex can be efficiently delivered to tumors 24 h after injection and can exist intact at least for 3 days. Furthermore, atelocollagen-mediated systemic administration of siRNAs such as enhancer of zeste homolog 2 and phosphoinositide 3'-hydroxykinase p110-alpha-subunit, which were selected as candidate targets for inhibition of bone metastasis, resulted in an efficient inhibition of metastatic tumor growth in bone tissues. In addition, upregulation of serum IL-12 and IFN-alpha levels was not associated with the in vivo administration of the siRNA/atelocollagen complex. Thus, for treatment of bone metastasis of prostate cancer, an atelocollagen-mediated systemic delivery method could be a reliable and safe approach to the achievement of maximal function of siRNA.

Journal Article

Animals; Bioware; Breast Neoplasms; Disease Models, Animal; Female; Humans; Luciferases; Mammary Neoplasms, Animal; MDA-MB-231-D3H1 cells; Mice; Mice, Nude; Neoplasm Metastasis; Plasmids; Transplantation, Heterologous; Tumor Cells, Cultured

INTRODUCTION Our goal was to generate xenograft mouse models of human breast cancer based on luciferase-expressing MDA-MB-231 tumor cells that would provide rapid mammary tumor growth; produce metastasis to clinically relevant tissues such as lymph nodes, lung, and bone; and permit sensitive in vivo detection of both primary and secondary tumor sites by bioluminescent imaging. METHOD Two clonal cell sublines of human MDA-MB-231 cells that stably expressed firefly luciferase were isolated following transfection of the parental cells with luciferase cDNA. Each subline was passaged once or twice in vivo to enhance primary tumor growth and to increase metastasis. The resulting luciferase-expressing D3H1 and D3H2LN cells were analyzed for long-term bioluminescent stability, primary tumor growth, and distal metastasis to lymph nodes, lungs, bone and soft tissues by bioluminescent imaging. Cells were injected into the mammary fat pad of nude and nude-beige mice or were delivered systemically via intracardiac injection. Metastasis was also evaluated by ex vivo imaging and histologic analysis postmortem. RESULTS The D3H1 and D3H2LN cell lines exhibited long-term stable luciferase expression for up to 4-6 months of accumulative tumor growth time in vivo. Bioluminescent imaging quantified primary mammary fat pad tumor development and detected early spontaneous lymph node metastasis in vivo. Increased frequency of spontaneous lymph node metastasis was observed with D3H2LN tumors as compared with D3H1 tumors. With postmortem ex vivo imaging, we detected additional lung micrometastasis in mice with D3H2LN mammary tumors. Subsequent histologic evaluation of tissue sections from lymph nodes and lung lobes confirmed spontaneous tumor metastasis at these sites. Following intracardiac injection of the MDA-MB-231-luc tumor cells, early metastasis to skeletal tissues, lymph nodes, brain and various visceral organs was detected. Weekly in vivo imaging data permitted longitudinal analysis of metastasis at multiple sites simultaneously. Ex vivo imaging data from sampled tissues verified both skeletal and multiple soft tissue tumor metastasis. CONCLUSION This study characterized two new bioluminescent MDA-MB-231-luc human breast carcinoma cell lines with enhanced tumor growth and widespread metastasis in mice. Their application to current xenograft models of breast cancer offers rapid and highly sensitive detection options for preclinical assessment of anticancer therapies in vivo.

Journal Article

Bioware; Lovo-6-luc-1 cells

Colorectal cancer is the fourth most common cancer in the United States with an estimated 130,000 new cases diagnosed each year. Many cases are asymptomatic and not diagnosed until late stage of disease. Identification of primary tumors at an earlier stage is advantageous in treatment planning and aids in decreasing the morbidity/mortality rate from recurrence. The aim of our studies is to establish a xenograft system for monitoring tumor growth and metastasis in vivo which allows continual evaluation of drug and drug regimen efficacy at all stages of tumor progression. LoVo-6-luc-1, a luciferase expressing cell line derived from LoVo human colorectal adenocarcinoma cells, was injected by various routes (subcutaneous, intraperitoneal and intracecal) into female SCID-bg mice. Tumor growth and metastatic spread was monitored weekly by in vivo imaging using the Xenogen IVISTM imaging platform. Visible bioluminescence signals were detected immediately after injection and high tumor take was seen in all of the models. In the subcutaneous model, we found a high correlation between mean bioluminescence and mean tumor volume. In the intraperitoneal and ceacum injected models, the onset of tumor spread was rapid and ex vivo imaging confirmed metastasis to multiple organs such as liver, lung, kidney, adrenal gland, spleen and ovary.