Search results for "REGULATION"
showing 10 items of 4463 documents
ER+ Breast Cancers Resistant to Prolonged Neoadjuvant Letrozole Exhibit an E2F4 Transcriptional Program Sensitive to CDK4/6 Inhibitors
2018
AbstractPurpose: This study aimed to identify biomarkers of resistance to endocrine therapy in estrogen receptor–positive (ER+) breast cancers treated with prolonged neoadjuvant letrozole.Experimental Design: We performed targeted DNA and RNA sequencing in 68 ER+ breast cancers from patients treated with preoperative letrozole (median, 7 months).Results: Twenty-four tumors (35%) exhibited a PEPI score ≥4 and/or recurred after a median of 58 months and were considered endocrine resistant. Integration of the 47 most upregulated genes (log FC > 1, FDR < 0.03) in letrozole-resistant tumors with transcription-binding data showed significant overlap with 20 E2F4-regulated genes (P =…
Membrane-anchored heat-shock protein 70 (Hsp70) in cancer.
2020
International audience; Hsp70 is a highly conserved and inducible heat shock protein that belongs to the HSP70 family of molecular chaperones and plays a central role in protein homeostasis. The main function of Hsp70 is to protect cells from physiological, pathological and environmental insults, as it assists an ATP-dependent manner the process of protein folding. Since Hsp70 provides critical cell survival functions, cancer cells are assumed to rely on this chaperone. Strong evidence suggests that Hsp70 is upregulated in different type of cancers and is involved in tumor growth, invasion, migration and resistance to anti-cancer therapy. Interestingly, this Hsp70 upregulation induces Hsp70…
Molecular, Biological and Structural Features of VL CDR-1 Rb44 Peptide, Which Targets the Microtubule Network in Melanoma Cells
2019
Microtubules are important drug targets in tumor cells, owing to their role in supporting and determining the cell shape, organelle movement and cell division. The complementarity-determining regions (CDRs) of immunoglobulins have been reported to be a source of anti-tumor peptide sequences, independently of the original antibody specificity for a given antigen. We found that, the anti-Lewis B mAb light-chain CDR1 synthetic peptide Rb44, interacted with microtubules and induced depolymerization, with subsequent degradation of actin filaments, leading to depolarization of mitochondrial membrane-potential, increase of ROS, cell cycle arrest at G2/M, cleavage of caspase-9, caspase-3 and PARP, …
The phospholipase DDHD1 as a new target in colorectal cancer therapy
2018
Background Our previous study demonstrates that Citrus-limon derived nanovesicles are able to decrease colon cancer cell viability, and that this effect is associated with the downregulation of the intracellular phospholipase DDHD domain-containing protein 1 (DDHD1). While few studies are currently available on the contribution of DDHD1 in neurological disorders, there is no information on its role in cancer. This study investigates the role of DDHD1 in colon cancer. Methods DDHD1 siRNAs and an overexpression vector were transfected into colorectal cancer and normal cells to downregulate or upregulate DDHD1 expression. In vitro and in vivo assays were performed to investigate the functional…
Regulation of GSK-3 activity by curcumin, berberine and resveratrol: Potential effects on multiple diseases.
2017
Natural products or nutraceuticals promote anti-aging, anti-cancer and other health-enhancing effects. A key target of the effects of natural products may be the regulation of the PI3K/PTEN/Akt/mTORC1/GSK-3 pathway. This review will focus on the effects of curcumin (CUR), berberine (BBR) and resveratrol (RES), on the PI3K/PTEN/Akt/mTORC1/GSK-3 pathway, with a special focus on GSK-3. These natural products may regulate the pathway by multiple mechanisms including: reactive oxygen species (ROS), cytokine receptors, mirco-RNAs (miRs) and many others. CUR is present the root of turmeric (Curcuma longa). CUR is used in the treatment of many disorders, especially in those involving inflammatory p…
Cancer therapy and treatments during COVID-19 era
2020
The COVID-19 pandemic has put a serious strain on health treatments as well at the economies of many nations. Unfortunately, there is not currently available vaccine for SARS-Cov-2/COVID-19. Various types of patients have delayed treatment or even routine check-ups and we are adapting to a virtual world. In many cases, surgeries are delayed unless they are essential. This is also true with regards to cancer treatments and screening. Interestingly, some existing drugs and nutraceuticals have been screened for their effects on COVID-19. Certain FDA approved drugs, vitamin, natural products and trace minerals may be repurposed to treat or improve the prevention of COVID-19 infections and disea…
Targeting prohibitins with chemical ligands inhibits KRAS-mediated lung tumours.
2017
KRAS is one of the most frequently mutated oncogenes in human non-small cell lung cancers (NSCLCs). RAS proteins trigger multiple effector signalling pathways including the highly conserved RAF-MAPK pathway. CRAF, a direct RAS effector protein, is required for KRAS-mediated tumourigenesis. Thus, the molecular mechanisms driving the activation of CRAF are intensively studied. Prohibitin 1 (PHB1) is an evolutionarily conserved adaptor protein and interaction of CRAF with PHB1 at the plasma membrane is essential for CRAF activation. Here, we demonstrate that PHB1 is highly expressed in NSCLC patients and correlates with poor survival. Targeting of PHB1 with two chemical ligands (rocaglamide an…
Melanoma in the liver: Oxidative stress and the mechanisms of metastatic cell survival.
2020
Abstract Metastatic melanoma is a fatal disease with a rapid systemic dissemination. The most frequent target sites are the liver, bone, and brain. Melanoma metastases represent a heterogeneous cell population, which associates with genomic instability and resistance to therapy. Interaction of melanoma cells with the hepatic sinusoidal endothelium initiates a signaling cascade involving cytokines, growth factors, bioactive lipids, and reactive oxygen and nitrogen species produced by the cancer cell, the endothelium, and also by different immune cells. Endothelial cell-derived NO and H2O2 and the action of immune cells cause the death of most melanoma cells that reach the hepatic microvascul…
PHD3 Controls Lung Cancer Metastasis and Resistance to EGFR Inhibitors through TGFα.
2018
Abstract Lung cancer is the leading cause of cancer-related death worldwide, in large part due to its high propensity to metastasize and to develop therapy resistance. Adaptive responses to hypoxia and epithelial–mesenchymal transition (EMT) are linked to tumor metastasis and drug resistance, but little is known about how oxygen sensing and EMT intersect to control these hallmarks of cancer. Here, we show that the oxygen sensor PHD3 links hypoxic signaling and EMT regulation in the lung tumor microenvironment. PHD3 was repressed by signals that induce EMT and acted as a negative regulator of EMT, metastasis, and therapeutic resistance. PHD3 depletion in tumors, which can be caused by the EM…
Comprehensive translational control of tyrosine kinase expression by upstream open reading frames
2016
Post-transcriptional control has emerged as a major regulatory event in gene expression and often occurs at the level of translation initiation. Although overexpression or constitutive activation of tyrosine kinases (TKs) through gene amplification, translocation or mutation are well-characterized oncogenic events, current knowledge about translational mechanisms of TK activation is scarce. Here, we report the presence of translational cis-regulatory upstream open reading frames (uORFs) in the majority of transcript leader sequences of human TK mRNAs. Genetic ablation of uORF initiation codons in TK transcripts resulted in enhanced translation of the associated downstream main protein-codin…