Accurate Sensitivity of Quantum Dots for Detection of HER2 Expression in Breast Cancer Cells and Tissues

635 Background: HER2-overexpressing or triple-negative [ER(-)/PR(-)/HER2(-)] breast cancers are associated with increased risk of brain metastases. The mechanisms leading to metastasis in each subtype are not well known. Methods: We introduced the wild-type HER2 gene into MDA-MB-231-luc-D3H2LN (231-Luc) cells, which are triple-negative breast cancer cells, and established HER2-expressing (63.2%) cells as 231-Luc-HER2 cells. We investigated the tumor formation following orthotopic inoculation and brain metastasis following intracardiac injection into nude mice. Metastasis was detected by bioluminescence imaging and confirmed in H&E staining and immunohistochemistry of vimentin and HER2 expressions. Flow cytometry analysis was used to detect the proportion of CD44+/CD24- cells, a maker for stem-like breast cancer cells. Results: 231-Luc-HER2 cells formed larger tumors in orthotopic xenograft models compared to 231-Luc cells, however, no significant difference was observed in proliferation in vitro. Neither 231-Luc-HER2 nor 231-Luc metastasized in the brain from the breast after orthotopic inoculation. After intracardiac injections of the 231-Luc-HER2 cells, brain metastasis developed (7/13 mice, 53.8%). Immunohistochemical analysis revealed that most metastasized cells expressed HER2, although we had injected a mixture of HER2-positive and HER2-negative cancer cells. Interestingly, administering Lapatinib, a dual EGFR and HER2 tyrosine kinase inhibitor, effectively prevented HER2-positive cells to colonize the brain. However, the HER2-negative 231-Luc-HER2 cells developed into brain metastases. In fact, the 231-Luc cells, which are HER2-negative, also metastasized in the brain (10/16 mice, 62.5%). Flow cytometry analysis of the 231-Luc-HER2 cells showed that HER2-positive cells decreased the population of CD44+/CD24- (HER2+/CD44+/CD24-: 86.8% and HER2-/CD44+/CD24-: 96.3%). Conclusions: The mechanism of brain metastases of HER2-positive breast cancer cells is different from that of HER2-negative breast cancer cells. It is therefore important to consider an additional therapeutic approach when dealing with HER2-negative cells in tumors having the heterogeneity of HER2 expression.

Download Full-text

Cadmium-free quantum dots as time-gated bioimaging probes in highly-autofluorescent human breast cancer cells

Chemical Communications ◽

10.1039/c2cc37529j ◽

2013 ◽

Vol 49 (6) ◽

pp. 624-626 ◽

Cited By ~ 67

Author(s):

Gopa Mandal ◽

Molly Darragh ◽

Y. Andrew Wang ◽

Colin D. Heyes

Keyword(s):

Breast Cancer ◽

Quantum Dots ◽

Cancer Cells ◽

Human Breast Cancer ◽

Breast Cancer Cells ◽

Human Breast Cancer Cells ◽

Human Breast

Download Full-text

Evaluating internalization and recycling of folate receptors in breast cancer cells using quantum dots

Journal of Photochemistry and Photobiology B Biology ◽

10.1016/j.jphotobiol.2020.111918 ◽

2020 ◽

Vol 209 ◽

pp. 111918

Author(s):

Camila A.P. Monteiro ◽

Aline D.P.R. Oliveira ◽

Ryan C. Silva ◽

Rennan R.M. Lima ◽

Fabricio O. Souto ◽

...

Keyword(s):

Breast Cancer ◽

Quantum Dots ◽

Cancer Cells ◽

Breast Cancer Cells ◽

Folate Receptors

Download Full-text

Mediation of HER2 expression-dependent antiproliferative and pro-apoptotic effect of pan-HER2-specific TKIs on breast cancer cells through STAT5 and JNK.

Journal of Clinical Oncology ◽

10.1200/jco.2013.31.15_suppl.e11606 ◽

2013 ◽

Vol 31 (15_suppl) ◽

pp. e11606-e11606

Author(s):

Daphne Gschwantler-Kaulich

Keyword(s):

Breast Cancer ◽

Cancer Cells ◽

Cell Lines ◽

Breast Cancer Cells ◽

Her2 Expression ◽

Her Family ◽

Proliferation And Apoptosis ◽

Apoptotic Effect

e11606 Background: HER-targeted tyrosine kinase inhibitors (TKIs) have demonstrated pro-apoptotic and antiproliferative effects in vitro and in vivo. The exact pathways through which TKIs exert their antineoplastic effects are, however, still not completely understood. Methods: Using Milliplex assays, we have investigated the effects of the three panHER-TKIs lapatinib, canertinib and afatinib on signal transduction cascade activation in SKBR3, T47D and Jurkat neoplastic cell lines. The growth-inhibitory effect of blockade of HER and of JNK and STAT5 signaling was measured by proliferation- and apoptosis-assays using formazan dye labeling of viable cells, Western blotting for cleaved PARP and immunolabeling for active caspase 3, respectively. Results: All three HER-TKIs clearly inhibited proliferation and increased apoptosis in HER2 overexpressing SKBR3 cells, while their effect was less pronounced on HER2 moderately expressing T47D cells where they exerted only a weak antiproliferative and essentially no pro-apoptotic effect. Remarkably, phosphorylation/activation of JNK and STAT5A/B were inhibited by HER-TKIs only in the sensitive, but not in the resistant cells. In contrast, phosphorylation/activation of ERK/MAPK, STAT3, CREB, p70 S6 kinase, IkBa, and p38 were equally affected by HER-TKIs in both cell lines, irrespective of their sensitivity against the HER-TKIs. Moreover, we demonstrated that direct pharmacological blockade of JNK and STAT5 abrogates cell growth in both HER-TKI-sensitive as well as -resistant breast cancer cells, respectively. Conclusions: We have shown that HER-TKIs exert a HER2 expression-dependent effect on proliferation and apoptosis in cancer cell lines in vitro, which is at least partially mediated by blockade of JNK and STAT5A/B. Despite slight differences in their specificity towards individual members of the HER family all three inhibitors had comparable antiproliferative and proapoptotic effects in vitro.

Download Full-text