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Nanoconjugation: A Materials Approach to Enhance Epidermal Growth Factor Induced Apoptosis.

ABSTRACT: Apoptosis evasion is a hallmark of cancer that motivates the development of novel strategies for inducing cell death in a controlled fashion. The size-compatibility of nanoparticles (NPs) with cellular components provides new opportunities for regulating cellular processes, potentially including apoptosis. We investigated the impact of the covalent attachment of epidermal growth factor (EGF) to 40 nm diameter Au NPs on cellular apoptosis levels, quantified as caspase-3 activity, in two in vitro cancer cell lines: A431 and HeLa. Our studies show that nanoconjugation enhances EGF-induced apoptosis in EGF receptor (EGFR) overexpressing A431 and triggers a quantifiable increase in apoptosis in HeLa. The latter has physiological receptor expression levels and does not show apoptosis in response to free EGF. Endocytosis and trafficking are involved in key EGFR regulation processes, most prominently signal termination. Our experimental findings indicate that these processes can be manipulated through nanoconjugation to induce apoptosis.

SUBMITTER: Wu L

PROVIDER: S-EPMC3966211 | biostudies-literature | 2014 Feb

REPOSITORIES: biostudies-literature

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Nanoconjugation: A Materials Approach to Enhance Epidermal Growth Factor Induced Apoptosis.

Wu Linxi L Yu Xinwei X Feizpour Amin A Reinhard Björn M BM

Biomaterials science 20140201 2

Apoptosis evasion is a hallmark of cancer that motivates the development of novel strategies for inducing cell death in a controlled fashion. The size-compatibility of nanoparticles (NPs) with cellular components provides new opportunities for regulating cellular processes, potentially including apoptosis. We investigated the impact of the covalent attachment of epidermal growth factor (EGF) to 40 nm diameter Au NPs on cellular apoptosis levels, quantified as caspase-3 activity, in two <i>in vit ...[more]

PMID: 24683470

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Project description:BACKGROUND & AIMS:Helicobacter pylori infection disrupts the balance between gastric epithelial cell proliferation and apoptosis, which is likely to lower the threshold for the development of gastric adenocarcinoma. H pylori infection is associated with epidermal growth factor (EGF) receptor (EGFR) activation through metalloproteinase-dependent release of EGFR ligands in gastric epithelial cells. Because EGFR signaling regulates cell survival, we investigated whether activation of EGFR following H pylori infection promotes gastric epithelial survival. METHODS:Mouse conditionally immortalized stomach epithelial cells (ImSt) and a human gastric epithelial cell line, AGS cells, as well as wild-type and kinase-defective EGFR (EGFRwa2) mice, were infected with the H pylori cag+ strain 7.13. Apoptosis, caspase activity, EGFR activation (phosphorylation), and EGFR downstream targets were analyzed. RESULTS:Inhibiting EGFR kinase activity or decreasing EGFR expression significantly increased H pylori-induced apoptosis in ImSt. Blocking H pylori-induced EGFR activation with a heparin-binding (HB)-EGF neutralizing antibody or abrogating a disintegrin and matrix metalloproteinase-17 (ADAM-17) expression increased apoptosis of H pylori-infected AGS and ImSt, respectively. Conversely, pretreatment of ImSt with HB-EGF completely blocked H pylori-induced apoptosis. H pylori infection stimulated gastric epithelial cell apoptosis in EGFRwa2 but not in wild-type mice. Furthermore, H pylori-induced EGFR phosphorylation stimulated phosphotidylinositol-3'-kinase-dependent activation of the antiapoptotic factor Akt, increased expression of the antiapoptotic factor Bcl-2, and decreased expression of the proapoptotic factor Bax. CONCLUSIONS:EGFR activation by H pylori infection has an antiapoptotic effect in gastric epithelial cells that appears to involve Akt signaling and Bcl family members. These findings provide important insights into the mechanisms of H pylori-associated tumorigenesis.

Project description:BackgroundThe efficacy of epidermal growth factor (EGF) receptor (EGFR) inhibitors in patients with non-small cell lung cancer (NSCLC), pancreatic cancer (PC), or colorectal cancer (CRC) has been demonstrated. However, dermatological reactions to these inhibitors can cause significant physical and psychosocial discomfort. The objective of the present study was to evaluate the efficacy of EGF ointment for EGFR inhibitor-related skin adverse events (ERSEs).Materials and methodsThis placebo-controlled, double-blind, multicenter, pilot phase III trial enrolled patients with NSCLC, PC, or CRC treated with EGFR inhibitors. Patients with grade ≥2 ERSEs were included. Patients were randomized to three treatment arms: arm 1, placebo; arm 2, 1 ppm of EGF ointment; and arm 3, 20 ppm of EGF ointment. Patients applied ointment to their skin lesions twice daily.ResultsEfficacy evaluation was available for 80 patients (9 for PC, 28 for NSCLC, and 43 for CRC). Responses were 44.4% in arm 1, 61.5% in arm 2, and 77.8% in arm 3. There was a linear correlation between EGF concentrations and responses (p = .012). Quality of life (QoL) was assessed for 74 patients. Maximum changes in composite scores by Skindex-16 after treatment were significantly different among arms (mean ± SD: -5.2 ± 8.6 for arm 1, -11.7 ± 14.2 for arm 2, and - 18.6 ± 17.7 for arm 3; p = .008). EGF arms showed significant improvement in emotions (p = .005) and functioning (p = .044) scores over the placebo arm.ConclusionEGF ointment is effective for managing ERSEs. It can also improve patients' QoL compared with placebo. Clinical trial identification number. NCT02284139 IMPLICATIONS FOR PRACTICE: Patients with non-small cell lung cancer, pancreatic cancer, or colorectal cancer who are treated with epidermal growth factor (EGF) receptor (EGFR) inhibitors may experience dermatologic reactions to their treatment. This study investigated the benefit of an EGF ointment in the treatment of these adverse events and observed the ointment to be effective in managing EGFR inhibitor-related skin adverse events.

Project description:Transforming growth factor-? (TGF-?) and epidermal growth factor (EGF) have critical roles in regulating the metastasis of aggressive breast cancers, yet the impact of epithelial-mesenchymal transition (EMT) induced by TGF-? in altering the response of breast cancer cells to EGF remains unknown. We show in this study that murine metastatic 4T1 breast cancer cells formed compact and dense spheroids when cultured under three-dimensional (3D) conditions, which was in sharp contrast to the branching phenotypes exhibited by their nonmetastatic counterparts. Using the human MCF10A series, we show that epithelial-type and nonmetastatic breast cancer cells were unable to invade to EGF, whereas their mesenchymal-type and metastatic counterparts readily invaded to EGF. Furthermore, EMT induced by TGF-? was sufficient to manifest dense spheroid morphologies, a phenotype that increased primary tumor exit and invasion to EGF. Post-EMT invasion to EGF was dependent on increased activation of EGF receptor (EGFR) and p38 mitogen-activated protein kinase, all of which could be abrogated either by pharmacologic (PF-562271) or by genetic (shRNA) targeting of focal adhesion kinase (FAK). Mechanistically, EMT induced by TGF-? increased cell-surface levels of EGFR and prevented its physical interaction with E-cadherin, leading instead to the formation of oncogenic signaling complexes with T?R-II. Elevated EGFR expression was sufficient to transform normal mammary epithelial cells, and to progress their 3D morphology from that of hollow acini to branched structures characteristic of nonmetastatic breast cancer cells. Importantly, we show that TGF-? stimulation of EMT enabled this EGFR-driven breast cancer model to abandon their inherent branching architecture and form large, undifferentiated masses that were hyperinvasive to EGF and showed increased pulmonary tumor growth upon tail vein injection. Finally, chemotherapeutic targeting of FAK was sufficient to revert the aggressive behaviors of these structures. Collectively, this investigation has identified a novel EMT-based approach to neutralize the oncogenic activities of EGF and TGF-? in aggressive and invasive forms of breast cancer.

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Nanoconjugation: A Materials Approach to Enhance Epidermal Growth Factor Induced Apoptosis.

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Nanoconjugation: A Materials Approach to Enhance Epidermal Growth Factor Induced Apoptosis.

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