Publications by authors named "Ivan Gorn-Hondermann"

Unlabelled: To identify the mechanisms of cisplatin resistance, global microRNA (miR) expression was tested. The expression of miR-145 was consistently higher in resistant cells. The expression of cyclin-dependent kinase 6 (CDK6), a potential target of miR-145, was lower in resistant cells, and inhibition of CDK4/6 protected cells from cisplatin.

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We have previously demonstrated the ability of lovastatin, a potent inhibitor of mevalonate synthesis, to induce tumor-specific apoptosis. The apoptotic effects of lovastatin were regulated in part by the integrated stress response (ISR) that regulates cellular responses to a wide variety of stress inducers. A key regulator of the ISR apoptotic response is activating transcription factor 3 (ATF3) and its target gene CHOP/GADD153.

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Background: Cellular stress responses trigger signaling cascades that inhibit proliferation and protein translation to help alleviate the stress or if the stress cannot be overcome induce apoptosis. In recent studies, we demonstrated the ability of lovastatin, an inhibitor of mevalonate synthesis, to induce the Integrated Stress Response as well as inhibiting epidermal growth factor receptor (EGFR) activation.

Methodology/principal Findings: In this study, we evaluated the effects of lovastatin on the activity of the LKB1/AMPK pathway that is activated upon cellular energy shortage and can interact with the above pathways.

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MicroRNAs (miRs) are short non-coding RNAs that bind complementary sequences in mRNA resulting in translation repression and/or mRNA degradation. We investigated expression of the reported metastasis-associated miRs-335, 206, 135a, 146a, 146b, 10b, 21, let7a and let7b in normal mucosa, non-metastatic and metastatic colorectal cancer (CRC). Expression of target miRs in micro-dissected paraffin embedded tissues was evaluated in 15 primary tumours with adjacent normal tissue from patients that were disease-free at 4 years (cohort A) and 19 paired primary tumours with corresponding liver metastases (cohort B) by quantitative real-time PCR.

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Background: Previous studies indicate that drugs targeting the Epidermal Growth Factor Receptor (EGFR) signaling pathways can induce objective responses, prolong time to progression and improve survival of patients with metastatic colorectal cancer (mCRC). EGFR expression in the primary tumour may not predict response to these agents and data is conflicting regarding the correlation of EGFR expression in the primary tumour with the metastatic site. In other tumour sites, the presence of EGFR mutations was associated with efficacy in a subset of patients.

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Archival tissue preserved in fixative constitutes an invaluable resource for histological examination, molecular diagnostic procedures and for DNA typing analysis in forensic investigations. However, available material is often limited in size and quantity. Moreover, recovery of DNA is often severely compromised by the presence of covalent DNA-protein cross-links generated by formalin, the most prevalent fixative.

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