B7-H3-Targeted Ultrasound Molecular Imaging

Ultrasound complements mammography as an imaging modality for breast cancer detection, especially in patients with dense breast tissue, but its utility is limited by low diagnostic accuracy. One emerging molecular tool to address this limitation involves contrast-enhanced ultrasound using microbubbles targeted to molecular signatures on tumor neovasculature. In this study, we illustrate how tumor vascular expression of B7-H3 (CD276), a member of the B7 family of ligands for T-cell coregulatory receptors, can be incorporated into an ultrasound method that can distinguish normal, benign, precursor, and malignant breast pathologies for diagnostic purposes. Through an IHC analysis of 248 human breast specimens, we found that vascular expression of B7-H3 was selectively and significantly higher in breast cancer tissues. B7-H3 immunostaining on blood vessels distinguished benign/precursors from malignant lesions with high diagnostic accuracy in human specimens. In a transgenic mouse model of cancer, the B7-H3–targeted ultrasound imaging signal was increased significantly in breast cancer tissues and highly correlated with ex vivo expression levels of B7-H3 on quantitative immunofluorescence. Our findings offer a preclinical proof of concept for the use of B7-H3–targeted ultrasound molecular imaging as a tool to improve the diagnostic accuracy of breast cancer detection in patients. Cancer Res; 75(12); 1–9. ©2015 AACR.

Breast cancer detection by B7-H3 targeted ultrasound molecular imaging

Ultrasound complements mammography as an imaging modality for breast cancer detection, especially in patients with dense breast tissue, but its utility is limited by low diagnostic accuracy. One emerging molecular tool to address this limitation involves contrast-enhanced ultrasound using microbubbles targeted to molecular signatures on tumor neovasculature. In this study, we illustrate how tumor vascular expression of B7-H3 (CD276), a member of the B7 family of ligands for T cell co-regulatory receptors, can be incorporated into an ultrasound method that can distinguish normal, benign, precursor and malignant breast pathologies for diagnostic purposes. Through an immunohistochemical analysis of 248 human breast specimens, we found that vascular expression of B7-H3 was selectively and significantly higher in breast cancer tissues. B7-H3 immunostaining on blood vessels distinguished benign/precursors from malignant lesions with high diagnostic accuracy in human specimens. In a
transgenic mouse model of cancer, the B7-H3-targeted ultrasound imaging signal was increased significantly in breast cancer tissues and highly correlated with ex vivo expression levels of B7-H3 on quantitative immunofluorescence. Our findings offer a preclinical proof of concept for the use of B7-H3-targeted ultrasound molecular imaging as a tool to improve the diagnostic accuracy of breast cancer detection in patients.

IL13R{alpha}2 Signaling in Colorectal Cancer Metastasis

IL13 signaling through its receptor IL13Rα2 plays a critical role in colon cancer invasion and liver metastasis, but the mechanistic features of this process are obscure. In this study, we identified a scaffold protein, FAM120A (C9ORF10), as a signaling partner in this process. FAM120A was overexpressed in human colon cancer cell lines and 55% of human colon cancer specimens. IL13Rα2-FAM120A coimmunoprecipitation experiments revealed further signaling network associations that could regulate the activity of IL13Rα2, including FAK, SRC, PI3K, G-protein–coupled receptors, and TRAIL receptors. In addition, FAM120A associated with kinesins and motor proteins involved in cargo movement along microtubules. IL13Rα2-triggered activation of the FAK and PI3K/AKT/mTOR pathways was mediated by FAM120A, which also recruited PI3K and functioned as a scaffold protein to enable phosphorylation and activation of PI3K by Src family kinases. FAM120A silencing abolished IL13-induced cell migration, invasion, and survival. Finally, antibody blockade of IL13Rα2 or FAM120A silencing precluded liver colonization in nude mice or metastasis. In conclusion, we identified FAM120A in the IL13/IL13Rα2 signaling pathway as a key mediator of invasion and liver metastasis in colon cancer. Cancer Res; 75(12); 1–11. ©2015 AACR.

Combined label-free quantitative proteomics and microRNA expression analysis of breast cancer unravel molecular differences with clinical implications.

Better knowledge of the biology of breast cancer has allowed the use of new targeted therapies, leading to improved outcome. High-throughput technologies allow deepening into the molecular architecture of breast cancer, integrating different levels of information, which is important if it helps in making clinical decisions. MicroRNA and protein expression profiles were obtained from 71 estrogen receptor-positive and 25 triple-negative breast cancer samples. RNA and proteins obtained from formalin-fixed, paraffin-embedded tumors were analyzed by RT-qPCR and LC-MS/MS respectively. We applied probabilistic graphical models representing complex biological systems as networks, confirming that estrogen receptor-positive and triple-negative breast cancer subtypes are distinct biological entities. The integration of miRNA and protein expression data unravels molecular processes that can be related to differences in the genesis and clinical evolution of these types of breast cancer. Our results confirm that triple-negative breast cancer has a unique metabolic profile that may be exploited for therapeutic intervention.

Hijacked Leukocyte Pathway for Targeted Delivery

Inflammation is a hallmark of cancer. Activated immune cells are intrinsically capable of homing to inflammatory sites. Using three inflammatory-driven disease mouse models, we show that grapefruit-derived nanovectors (GNV) coated with inflammatory-related receptor enriched membranes of activated leukocytes (IGNVs) are enhanced for homing to inflammatory tumor tissues. Blocking LFA-1 or CXCR1 and CXCR2 on the IGNVs significantly inhibits IGNV homing to the inflammatory tissue. The therapeutic potential of IGNVs was further demonstrated by enhancing the chemotherapeutic effect as shown by inhibition of tumor growth in two tumor models and inhibiting the inflammatory effects of dextran sulfate sodium-induced mouse colitis. The fact that IGNVs are capable of homing to inflammatory tissue and that chemokines are overexpressed in diseased human tissue provides the rationale for using IGNVs to more directly deliver therapeutic agents to inflammatory tumor sites and the rationale for the use of IGNVs as treatment for certain cancers in personalized medicine. Cancer Res; 75(12); 1–10. ©2015 AACR.