Stem cells have the property to induce the invasion of primary somatic cells through insulin-like growth factor I (IGF-I)- or II (IGF-II)-mediated activation of mechanistic target of rapamycin complex 1 (mTORC1). We propose downstream of mTORC1 stem cell-induced invasion is mediated by hypoxia-inducible factor 1-alpha (HIF-1α)-regulated matrix metalloproteinases. Human stem cells use this mechanism to induce invasion and thereby attract cells from the microenvironment in vivo.
Lukas Kenner and colleagues report patients suffering from oropharyngeal squamous cell carcinoma without detectable p16 may benefit from postoperative radiotherapy, whereas p16-positive patients do not benefit from additional treatment. The report is now online in the journal Laryngoscope.
Signal transducers and activators of transcription (STATs) are latent, cytoplasmic transcription factors. Janus kinases (JAKs) and activated CDC42-associated kinase-1 (ACK1/TNK2) catalyse the phosphorylation of STAT1 and the expression of its target genes. Here we demonstrate that catalytically active ACK1 promotes the phosphorylation and nuclear accumulation of STAT1 in transformed kidney cells.
Chronic myeloid leukemia (CML) is increasingly treated with the BCR/ABL1 inhibitor Nilotinib. Although otherwise well-tolerated, Nilotinib has been associated with progressive arterial occlusive disease (AOD). Our objective was to determine the exact frequency of AOD and examine effects of Nilotinib and Imatinib on endothelial cells to explain AOD-development. In contrast to Imatinib, Nilotinib was found to upregulate pro-atherogenic adhesion-proteins (ICAM-1, E-selectin, VCAM-1) on human endothelial cells.
The p21-activated kinases (PAKs) are key nodes in oncogenic signalling pathways controlling growth, survival, and motility of cancer cells. Their activity is increased in many human cancers and is associated with poor prognosis. We show now that PAK1 and PAK2 are the critical isoforms in a BCR/ABL1+ haematopoietic malignancy. In suspension, leukaemic cells deficient for PAK1 and PAK2 undergo apoptosis, while the loss of either protein is well tolerated. However, we found that leukaemic cells explicitly require PAK2 to grow towards an extracellular matrix.
Five students from the Faculty of Medicine at İstanbul Medeniyet University joined the LBI-Research teams for two months to get some initial training in cancer research. Their stay is partly funded by the ERASMUS-Program.
In chronic myeloid leukemia BCR-ABL1 mutations and activation of additional pro-oncogenic pathways cause therapy resistance. Drug combinations covering a broad range of targets may overcome resistance.We investigated a compound that inhibits proliferation and survival of tyrosine kinase inhibitor-resistant BCR-ABL1+ cell lines. Succesful drug-combinations blocked multiple signalling cascades and molecules, including STAT3 and STAT5.
Androgen-deprivation remains an important therapeutic option for prostate cancer, and thus castration-resistance is lethal. Despite intense efforts to understand the mechanisms of therapy resistance, the underlying cells remain ill described. We now describe in wild-type (WT) mouse prostates a rare population of luminal progenitor cells that tolerate androgen deprivation and persist or are enriched 2-3 weeks after castration.
Stromal-derived IGF2 promotes colon cancer progression via paracrine and autocrine mechanisms.
The insulin-like growth factor (IGF) signaling axis has an important role in intestinal carcinogenesis and overexpression of IGF2 is an accepted risk factor for colorectal cancer (CRC) development. Genetic amplifications and loss of imprinting contribute to the upregulation of IGF2, but insufficiently explain the extent of IGF2 expression in a subset of patients.