Multiphoton Imaging of Labeled Breast Cancer Cells to Quantify Intra and Extracellular Receptors

Every year 200,000 women in the United States are diagnosed with breast cancer. Of the cases diagnosed, 10% -15% are classified as triple negative breast cancer (TNBC) due to the absence of estrogen, progesterone, and HER-2/Neu receptors. This breast cancer sub-type is markedly more aggressive and twice as likely to develop in premenopausal women. TNBC is resistant to endocrine therapies and current targeted agents, making clinical need for the development of validated therapeutics for TNBC a pressing matter. To initiate drug development, the internalization of directly immunolabeled epidermal growth factor receptors (EGFR) in SK-BR-3 human breast adenocarcinoma cells was quantitated using live-cell multiphoton microscopy for 30 minutes over 5 minute intervals. EGFR targeting is of interest because its internalization triggers the signaling pathway that disrupts cell-cell adhesion and induces cell motility. The images acquired were processed using ImageJ and analyzed through line profiles. After measuring the full width half max at each time point of the 30-minute time series, it was determined that significant EGFR internalization did not occur

Role of Scaffold Protein Proline-, Glutamic Acid-, and Leucine-Rich Protein 1 (PELP1) in the Modulation of Adrenocortical Cancer Cell Growth

PELP1 acts as an estrogen receptor (ER) coactivator that exerts an essential role in the ER's functions. ER coregulators have a critical role in the progression and response to hormonal treatment of estrogen-dependent tumors. We previously demonstrated that, in adrenocortical carcinoma (ACC), ER\u3b1 is upregulated and that estradiol activates the IGF-II/IGF1R signaling pathways defining the role of this functional cross-talk in H295R ACC cell proliferation. The aim of this study was to determine if PELP1 is expressed in ACC and may play a role in promoting the interaction between ER\u3b1 and IGF1R allowing the activation of pathways important for ACC cell growth. The expression of PELP1 was detected by Western blot analysis in ACC tissues and in H295R cells. H295R cell proliferation decrease was assessed by A3-(4,5-Dimethylthiaoly)-2,5-diphenyltetrazolium bromide (MTT) assay and [3H] thymidine incorporation. PELP1 is expressed in ACC tissues and in H295R cells. Moreover, treatment of H295R with E2 or IGF-II induced a multiprotein complex formation consisting of PELP1, IGF1R, ER\u3b1, and Src that is involved in ERK1/2 rapid activation. PELP1/ER/IGF1R/c-Src complex identification as part of E2- and IGF-II-dependent signaling in ACC suggests PELP1 is a novel and more efficient potential target to reduce ACC growth

Proteomic resistance biomarkers for PI3K inhibitor in triple negative breast cancer patient-derived xenograft models

PI3K pathway activation is frequently observed in triple negative breast cancer (TNBC). However, single agent PI3K inhibitors have shown limited anti-tumor activity. To investigate biomarkers of response and resistance mechanisms, we tested 17 TNBC patient-derived xenograft (PDX) models representing diverse genomic backgrounds and varying degrees of PI3K pathway signaling activities for their tumor growth response to the pan-PI3K inhibitor, BKM120. Baseline and post-treatment PDX tumors were subjected to reverse phase protein array (RPPA) to identify protein markers associated with tumor growth response. While BKM120 consistently reduced PI3K pathway activity, as demonstrated by reduced levels of phosphorylated AKT, percentage tumor growth inhibition (%TGI) ranged from 35% in the least sensitive to 84% in the most sensitive model. Several biomarkers showed significant association with resistance, including elevated baseline levels of growth factor receptors (EGFR, pHER3 Y1197), PI3Kp85 regulatory subunit, anti-apoptotic protein BclXL, EMT (Vimentin, MMP9, IntegrinaV), NFKB pathway (IkappaB, RANKL), and intracellular signaling molecules including Caveolin, CBP, and KLF4, as well as treatment-induced increases in the levels of phosphorylated forms of Aurora kinases. Interestingly, increased AKT phosphorylation or PTEN loss at baseline were not significantly correlated to %TGI. These results provide important insights into biomarker development for PI3K inhibitors in TNBC

Sorting Mechanisms Regulating Membrane Protein Traffic in the Apical Transcytotic Pathway of Polarized MDCK Cells

The transcytotic pathway followed by the polymeric IgA receptor (pIgR) carrying its bound ligand (dIgA) from the basolateral to the apical surface of polarized MDCK cells has been mapped using morphological tracers. At 20°C dIgA-pIgR internalize to interconnected groups of vacuoles and tubules that comprise the endosomal compartment and in which they codistribute with internalized transferrin receptors (TR) and epidermal growth factor receptors (EGFR). Upon transfer to 37°C the endosome vacuoles develop long tubules that give rise to a distinctive population of 100-nm-diam cup-shaped vesicles containing pIgR. At the same time, the endosome gives rise to multivesicular endosomes (MVB) enriched in EGFR and to 60-nm-diam basolateral vesicles. The cup-shaped vesicles carry the dIgA/pIgR complexes to the apical surface where they exocytose

Antibody-Drug Gold Nanoantennas with Raman Spectroscopic Fingerprints for in Vivo Tumour Theranostics

Inspired by the ability of SERS nanoantennas to provide an integrated platform to enhance disease targeting in vivo, we developed a highly sensitive probe for in vivo tumoral recognition with the capacity to target specific cancer biomarkers such as epidermal growth factor receptors (EGFR) on human cancer cells and xenograft tumour models. Here, we used ~90 nm gold nanoparticles capped by a Raman reporter, encapsulated and entrapped by larger polymers and a FDA antibody-drug conjugate –Cetuximab (Erbitux®) – that specifically targets EGFR and turns off a main signalling cascade for cancer cells to proliferate and survive. These drug/SERS gold nanoantennas present a high Raman signal both in cancer cells and in mice bearing xenograft tumours. Moreover, the Raman detection signal is accomplished simultaneously by extensive tumour growth inhibition in mice, making these gold nanoantennas ideal for cancer nanotheranostics, i.e. tumour detection and tumoral cell inhibition at the same time

The prognostic impact of EGFR, ErbB2 and MET gene amplification in human gastric carcinomas as measured by quantitative Real-Time PCR

Purpose: Identification of critical genes which play pivotal roles in controlling tumor growth and survival will establish the basis for developing therapeutic targets. In this study, we focused on frequencies of EGFR, ErbB2 and MET gene amplification in gastric cancer patients to develop personalized medicine to improve the treatment. Method: EGFR, ErbB2 and MET gene amplification, and mRNA expression were analyzed by the quantitative Real-Time PCR in paraffin-embedded samples from 115 patients with gastric cancer. Results: EGFR, ErbB2 and MET genes were amplified in 11.3 % (13/115), 6.1 % (7/115) and 19.1 % (22/115) of cancerous specimens, respectively. The correlation coefficient test clearly indicated that gene amplification in these three genes was positively correlated with mRNA transcription (EGFR: R = 0.631, p = 0.009; ErbB2: R = 0.652, p = 0.023; MET: R = 0.715, p < 0.001). EGFR and MET gene amplification was significantly associated with Ki-67 MI (p = 0.022 and p = 0.015). MET amplification was also significantly associated with age of ≥60 years (p = 0.021) and tumor size of ≥5 cm (p = 0.032). MET amplification, but not EGFR and ErbB2, was a significant prognostic factor in poor survival among patients with gastric cancer. Conclusions: EGFR, ErbB2 and MET genes are frequently amplified in gastric carcinoma. EGFR, ErbB2 and MET gene amplification is positively correlated with mRNA transcription. MET gene amplification correlates with a poor prognosis and poor survival in gastric carcinomas. © 2015, Springer-Verlag Berlin Heidelberg

Epidermal growth factor receptor subunit locations determined in hydrated cells with environmental scanning electron microscopy

Imaging single epidermal growth factor receptors (EGFR) in intact cells is presently limited by the available microscopy methods. Environmental scanning electron microscopy (ESEM) of whole cells in hydrated state in combination with specific labeling with gold nanoparticles was used to localize activated EGFRs in the plasma membranes of COS7 and A549 cells. The use of a scanning transmission electron microscopy (STEM) detector yielded a spatial resolution of 3 nm, sufficient to identify the locations of individual EGFR dimer subunits. The sizes and distribution of dimers and higher order clusters of EGFRs were determined. The distance between labels bound to dimers amounted to 19 nm, consistent with a molecular model. A fraction of the EGFRs was found in higher order clusters with sizes ranging from 32–56 nm. ESEM can be used for quantitative whole cell screening studies of membrane receptors, and for the study of nanoparticle-cell interactions in general

Molekulare Veränderungen beim Pankreaskarzinom

Zusammenfassung: Grundlagen: Das Pankreaskarzinom hat eine infauste Prognose. Die Ursachen für das aggressive Tumorwachstum und die frühe Metastasierung sind nur unzureichend bekannt. Mit Hilfe von modernen molekularbiologischen Untersuchungstechniken ist es in den vergangenen Jahren gelungen, einen Einblick in die Pathophysiologie dieser Erkrankung zu gewinnen. Methodik: Im Rahmen dieser Übersicht wird die pathogenetische Bedeutung von Wachstumsfaktor-Rezeptoren (EGFR, c-erbB-2, c-erbB-3), Wachstumsfaktoren (EGF, TGF-α, Amphiregulin, Betacellulin, TGF-βs, FGFs) sowie von Genmutationen (p53, K-ras) und Adhäsionsmolekülen beim humanen Pankreaskarzinom dargestellt. Ergebnisse: In einer signifikanten Anzahl der Pankreaskarzinome sind Wachstumsfaktorrezeptoren (EGFR, c-erbB-2, c-erbB-3), Wachstumsfaktoren (EGF, TGF-α, Amphiregulin, Betacellulin, TGF-βs, FGFs) und Adhäsionsmoleküle (ICAM-1, ELAM-1) überexprimiert sowie Genmutationen (p53, K-ras) vorhanden. Allerdings sind nicht alle diese molekularen Veränderungen mit einem schnelleren Tumorwachstum und einer schlechteren Prognose nach Tumorresektion vergesellschaftet. Schlußfolgerungen: Molekulare Störungen in Pankreaskarzinomzellen tragen zum malignen Phänotyp bei. Diese Veränderungen erklären, warum die Pankreaskarzinomzellen schnell proliferieren und nur eine geringe Ansprechbarkeit auf adjuvante onkologische Behandlungen zeige

The Most Common Cutaneous Side Effects of Epidermal Growth Factor Receptor Inhibitors and Their Management

The use of epidermal growth factor receptor inhibitors (EGFRI) for the treatment of solid tumors is increasing due to elevated expression of epidermal growth factor receptors (EGFR) in the stimulation of tumor development. EGFR inhibitors have shown to be effective in the treatment of neoplasms of the head, neck, colon, and lung. Inhibition of EGFR may cause cutaneous reactions in more than 50% of patients. The most common skin manifestations are papulopustular lesions in the seborrhoeic areas (upper torso, face, neck, and scalp). Other cutaneous side effects include xerosis and hair and nail changes. The onset of eruption is usually within one to three weeks after starting therapy, although in some cases it may occur much later. All dermatologic side effects are reversible and generally resolve after adequate therapy. However, for a minority of patients side effects are severe and intolerable, demanding dose reduction or even interruption of therapy. A positive correlation has been demonstrated between the degree of cutaneous toxicity and the antitumor response. For dermatologists the goal is to provide treatment of symptoms, so that the patient may continue to benefit from the EGFRI therapy. However, frequent cutaneous manifestations, even though related to a better antitumor response, may limit use of the therapy considering the interference with patient quality of life. Early management of cutaneous side effects of EGFRI may prevent severe, extensive symptoms, the need for dose reduction, or antitumor therapy interruption. This indicates a dermatologist should play a role in early stages of treatment. </p