The First Mouse Model of Primary Osteosarcoma of the Breast

Non-invasive Fluorescence Imaging of Breast Cancer Metastasis to the Brain in an Orthotopic Nude-mouse Model With Very-narrow-band-width Laser Excitation of Red Fluorescent Protein Resulting in an Ultra-bright Signal Without Skin Autofluorescence

BACKGROUND/AIM

Breast-cancer metastasis to the brain is an intractable disease. To discover improved therapy for this disease, we developed a precise non-invasively-imageable orthotopic nude-mouse model, using very-narrow-band-width laser fluorescence excitation.

MATERIALS AND METHODS

Female nu/nu nude mice, aged 4-8 weeks, were inoculated through the midline of the skull with triple-negative human MDA-MB-231 breast cancer cells (5×105) expressing red fluorescent protein (RFP). The mice were imaged with the Analytik Jena UVP Biospectrum Advanced at 520 nm excitation with peak emission at 605 nm.

RESULTS

Three weeks after injection of MDA-MB-231-RFP cells in the brain, non-invasive fluorescence images of the breast tumor growing on the brain were obtained. The images of the tumor were very bright, with well-defined margins with no detectable skin autofluorescence background. Images obtained at various angles showed that the extent of the tumor margins could be precisely measured. A skin flap over the skull confirmed that the tumor was growing on the surface of the brain which is a frequent occurrence in breast cancer.

CONCLUSION

A precise orthotopic model of RFP-expressing breast-cancer metastasis to the brain was developed that could be non-invasively imaged with very-narrow-band-width laser excitation, resulting in an ultra-bright, ultra-low-background signal. The model will be useful in discovering improved therapeutics for this recalcitrant disease.

Primary breast osteosarcoma in a patient previously treated for ipsilateral invasive ductal carcinoma: An unusual case report with clinical and genomic features

Primary breast osteosarcoma is a rare subtype of breast malignancy with limited clinical evidence, inadequate biological understanding, and unmet treatment consensus. Here, we report an unusual case of primary breast osteosarcoma developing in the same quadrant of the breast 2 years after initial dissection and radiation of invasive ductal carcinoma. Thorough evaluations of imaging and pathology were conducted while genomic alterations of both primary and secondary tumors, as well as peripheral blood samples, were explored through the next-generation sequencing technique. A comprehensive review of the current literature was also performed on this rare malignancy.

Establishment of Patient-derived Orthotopic Xenografts (PDX) as Models for Pancreatic Ductal Adenocarcinoma

BACKGROUND/AIM

Pancreatic cancer (PC) is one of the leading causes of cancer-related death. The purpose of the present study was to establish a patient-derived orthotopic xenograft model (PDOX) for pancreatic ductal adenocarcinoma (PDAC), thus providing a tumor microenvironment resembling that of the human pancreas to identify novel potential biomarkers and treatment regimens.

MATERIALS AND METHODS

PDAC tissue samples were received from 35 patients, following informed consent, and three mouse strains were implemented.

RESULTS

Successful PDOX engraftment was performed in nonobese diabetic/severe combined immunodeficient (NOD/SCID) and NOD/SCID gamma (NSG) mice. Nonetheless, we found a higher rate of successful engraftment and tumor growth in NSG compared to NOD/SCID mice, possibly owning to the different level of immunosuppression and more specifically of the natural killer cells presence.

CONCLUSION

Our suggested PDOX model represents a preclinical cancer research model with a high affinity for the patient's tumor microenvironment, thus enabling the acceleration of PDAC research.