Bid mediates anti-apoptotic COX-2 induction through the IKKbeta/NFkappaB pathway due to 5-MCDE exposure

Polymorphisms within autophagy-related genes as susceptibility biomarkers for pancreatic cancer: A meta-analysis of three large European cohorts and functional characterization

Pancreatic ductal adenocarcinoma (PDAC) is one of the most lethal cancers with patients having unresectable or metastatic disease at diagnosis, with poor prognosis and very short survival. Given that genetic variation within autophagy-related genes influences autophagic flux and susceptibility to solid cancers, we decided to investigate whether 55,583 single nucleotide polymorphisms (SNPs) within 234 autophagy-related genes could influence the risk of developing PDAC in three large independent cohorts of European ancestry including 12,754 PDAC cases and 324,926 controls. The meta-analysis of these populations identified, for the first time, the association of the BIDrs9604789 variant with an increased risk of developing the disease (ORMeta = 1.31, p = 9.67 × 10-6). We also confirmed the association of TP63rs1515496 and TP63rs35389543 variants with PDAC risk (OR = 0.89, p = 6.27 × 10-8 and OR = 1.16, p = 2.74 × 10-5). Although it is known that BID induces autophagy and TP63 promotes cell growth, cell motility and invasion, we also found that carriers of the TP63rs1515496G allele had increased numbers of FOXP3+ Helios+ T regulatory cells and CD45RA+ T regulatory cells (p = 7.67 × 10-4 and p = 1.56 × 10-3), but also decreased levels of CD4+ T regulatory cells (p = 7.86 × 10-4). These results were in agreement with research suggesting that the TP63rs1515496 variant alters binding sites for FOXA1 and CTCF, which are transcription factors involved in modulating specific subsets of regulatory T cells. In conclusion, this study identifies BID as new susceptibility locus for PDAC and confirms previous studies suggesting that the TP63 gene is involved in the development of PDAC. This study also suggests new pathogenic mechanisms of the TP63 locus in PDAC.

Performance of collagen-based matrices from Nile tilapia skin: A pilot proteomic study in a murine model of wound healing

Full-thickness cutaneous trauma, due to the lack of dermis, leads to difficulty in epithelialization by keratinocytes, developing a fibrotic scar, with less elasticity than the original skin, which may have disorders in predisposed individuals, resulting in hypertrophic scar and keloids. Biomedical materials have excellent characteristics, such as good biocompatibility and low immunogenicity, which can temporarily replace traditional materials used as primary dressings. In this work, we developed two dermal matrices based on Nile tilapia collagen, with (M_GAG) and without (M) glycosaminoglycans, using a sugarcane polymer membrane as a matrix support. To assess the molecular mechanisms driving wound healing, we performed qualitative proteomic analysis on the wound bed in an in vivo study involving immunocompetent murine models at 14 and 21 days post-full-thickness skin injury. Gene Ontology and Pathway analysis revealed that both skins were markedly represented by modulation of the immune system, emphasizing controlling the acute inflammation response at 14 and 21 days post-injury. Furthermore, both groups showed significant enrichment of pathways related to RNA and protein metabolism, suggesting an increase in protein synthesis required for tissue repair and proper wound closure. Other pathways, such as keratinization and vitamin D3 metabolism, were also enriched in the groups treated with M matrix. Finally, both matrices improved wound healing in a full post-thick skin lesion. However, our preliminary molecular data reveals that the collagen-mediated healing matrix lacking glycosaminoglycan (M) exhibited a phenotype more favorable to tissue repair, making it more suitable for use before skin grafts.

Stromal fibroblast growth factor 2 reduces the efficacy of bromodomain inhibitors in uveal melanoma

Alterations in transcriptional programs promote tumor development and progression and are targetable by bromodomain and extraterminal (BET) protein inhibitors. However, in a multi‐site clinical trial testing the novel BET inhibitor, PLX51107, in solid cancer patients, liver metastases of uveal melanoma (UM) patients progressed rapidly following treatment. Mechanisms of resistance to BET inhibitors in UM are unknown. We show that fibroblast growth factor 2 (FGF2) rescued UM cells from growth inhibition by BET inhibitors, and FGF2 effects were reversible by FGF receptor (FGFR) inhibitors. BET inhibitors also increased FGFR protein expression in UM cell lines and in patient tumor samples. Hepatic stellate cells (HSCs) secrete FGF2, and HSC‐conditioned medium provided resistance of UM cells to BET inhibitors. PLX51107 was ineffective in vivo, but the combination of a FGFR inhibitor, AZD4547, and PLX51107 significantly suppressed the growth of xenograft UM tumors formed from subcutaneous inoculation of UM cells with HSCs and orthotopically in the liver. These results suggest that co‐targeting of FGFR signaling is required to increase the responses of metastatic UM to BET inhibitors.

Stromal fibroblast growth factor 2 reduces the efficacy of bromodomain inhibitors in uveal melanoma

Alterations in transcriptional programs promote tumor development and progression and are targetable by bromodomain and extraterminal (BET) protein inhibitors. However, in a multi-site clinical trial testing the novel BET inhibitor, PLX51107, in solid cancer patients, liver metastases of uveal melanoma (UM) patients progressed rapidly following treatment. Mechanisms of resistance to BET inhibitors in UM are unknown. We show that fibroblast growth factor 2 (FGF2) rescued UM cells from growth inhibition by BET inhibitors, and FGF2 effects were reversible by FGF receptor (FGFR) inhibitors. BET inhibitors also increased FGFR protein expression in UM cell lines and in patient tumor samples. Hepatic stellate cells (HSCs) secrete FGF2, and HSC-conditioned medium provided resistance of UM cells to BET inhibitors. PLX51107 was ineffective in vivo, but the combination of a FGFR inhibitor, AZD4547, and PLX51107 significantly suppressed the growth of xenograft UM tumors formed from subcutaneous inoculation of UM cells with HSCs and orthotopically in the liver. These results suggest that co-targeting of FGFR signaling is required to increase the responses of metastatic UM to BET inhibitors.

Inhibition of O-GlcNAcase Sensitizes Apoptosis and Reverses Bortezomib Resistance in Mantle Cell Lymphoma through Modification of Truncated Bid

Aberrant energy metabolism represents a hallmark of cancer and contributes to numerous aggressive behaviors of cancer cells, including cell death and survival. Despite the poor prognosis of mantle cell lymphoma (MCL), due to the inevitable development of drug resistance, metabolic reprograming of MCL cells remains an unexplored area. Posttranslational modification of proteins via O-GlcNAcylation is an ideal sensor for nutritional changes mediated by O-GlcNAc transferase (OGT) and is removed by O-GlcNAcase (OGA). Using various small-molecule inhibitors of OGT and OGA, we found for the first time that O-GlcNAcylation potentiates MCL response to bortezomib. CRISPR interference of MGEA5 (encoding OGA) validated the apoptosis sensitization by O-GlcNAcylation and OGA inhibition. To identify the potential clinical candidates, we tested MCL response to drug-like OGA inhibitor, ketoconazole, and verified that it exerts similar sensitizing effect on bortezomib-induced apoptosis. Investigations into the underlying molecular mechanisms reveal that bortezomib and ketoconazole act in concert to cause the accumulation of truncated Bid (tBid). Not only does ketoconazole potentiate tBid induction, but also increases tBid stability through O-GlcNAcylation that interferes with tBid ubiquitination and proteasomal degradation. Remarkably, ketoconazole strongly enhances bortezomib-induced apoptosis in de novo bortezomib-resistant MCL cells and in patient-derived primary cells with minimal cytotoxic effect on normal peripheral blood mononuclear cells and hepatocytes, suggesting its potential utility as a safe and effective adjuvant for MCL. Together, our findings provide novel evidence that combination of bortezomib and ketoconazole or other OGA inhibitors may present a promising strategy for the treatment of drug-resistant MCL. Mol Cancer Ther; 17(2); 484-96. ©2017 AACR.

BH3-Only Proteins in Health and Disease

BH3-only proteins are proapoptotic members of the broader Bcl-2 family, which promote cell death by directly or indirectly activating Bax and Bak. The expression of BH3-only proteins is regulated both transcriptionally and posttranscriptionally in a cell type-specific and a tissue-specific manner. Research over the last 20 years has provided significant insights into their roles in tissue homeostasis and various pathologies, which in turn has led to the development of novel therapeutics for numerous diseases. In this review, a snapshot of the progress over this period is given, including our current understanding of their regulation, mode of action, role in mammalian development, and pathology.

DNA methylation is critical for tooth agenesis: implications for sporadic non-syndromic anodontia and hypodontia

Hypodontia is caused by interactions among genetic, epigenetic, and environmental factors during tooth development, but the actual mechanism is unknown. DNA methylation now appears to play a significant role in abnormal developments, flawed phenotypes, and acquired diseases. Methylated DNA immunoprecipitation (MeDIP) has been developed as a new method of scanning large-scale DNA-methylation profiles within particular regions or in the entire genome. Here, we performed a genome-wide scan of paired DNA samples obtained from 4 patients lacking two mandibular incisors and 4 healthy controls with normal dentition. We scanned another female with non-syndromic anodontia and her younger brother with the same gene mutations of the PAX9,MSX1,AXIN2 and EDA, but without developmental abnormalities in the dentition. Results showed significant differences in the methylation level of the whole genome between the hypodontia and the normal groups. Nine genes were spotted, some of which have not been associated with dental development; these genes were related mainly to the development of cartilage, bone, teeth, and neural transduction, which implied a potential gene cascade network in hypodontia at the methylation level. This pilot study reveals the critical role of DNA methylation in hypodontia and might provide insights into developmental biology and the pathobiology of acquired diseases.

BH3-only proteins: a 20-year stock-take

BH3-only proteins are the sentinels of cellular stress, and their activation commits cells to apoptosis. Since the discovery of the first BH3-only protein BAD almost 20 years ago, at least seven more BH3-only proteins have been identified in mammals. They are regulated by a variety of environmental stimuli or by developmental cues, and play a crucial role in cellular homeostasis. Some are considered to be tumor suppressors, and also play a significant role in other pathologies. Their non-apoptotic functions are controversial, but there is broad consensus emerging regarding their role in apoptosis, which may help in designing better therapeutic agents for treating a variety of human diseases.

The BCL-2 family protein Bid is critical for pro-inflammatory signaling in astrocytes

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease characterized by the loss of motoneurons in the spinal cord, brainstem and motor cortex. Mutations in the superoxide dismutase 1 (SOD1) gene represent a frequent genetic determinant and recapitulate a disease phenotype similar to ALS when expressed in mice. Previous studies using SOD1(G93A) transgenic mice have suggested a paracrine mechanism of neuronal loss, in which cytokines and other toxic factors released from astroglia or microglia trigger motoneuron degeneration. Several pro-inflammatory cytokines activate death receptors and may downstream from this activate the Bcl-2 family protein, Bid. We here sought to investigate the role of Bid in astrocyte activation and non-cell autonomous motoneuron degeneration. We found that spinal cord Bid protein levels increased significantly during disease progression in SOD1(G93A) mice. Subsequent experiments in vitro indicated that Bid was expressed at relatively low levels in motoneurons, but was enriched in astrocytes and microglia. Bid was strongly induced in astrocytes in response to pro-inflammatory cytokines or exposure to lipopolysaccharide. Experiments in bid-deficient astrocytes or astrocytes treated with a small molecule Bid inhibitor demonstrated that Bid was required for the efficient activation of transcription factor nuclear factor-κB in response to these pro-inflammatory stimuli. Finally, we found that conditioned medium from wild-type astrocytes, but not from bid-deficient astrocytes, was toxic when applied to primary motoneuron cultures. Collectively, our data demonstrate a new role for the Bcl-2 family protein Bid as a mediator of astrocyte activation during neuroinflammation, and suggest that Bid activation may contribute to non-cell autonomous motoneuron degeneration in ALS.

Novel compound PS-101 exhibits selective inhibition in non-small-cell lung cancer cell by blocking the EGFR-driven antiapoptotic pathway

This study investigated the anticancer effect of a novel compound PS-101 in human lung cancer cells. By phenotype screening, PS-101 exhibited highly selective inhibition in EGFR-overexpressed non-small cell lung cancer cells NCI-H460 and A549 while displaying no obvious toxicity to normal hepatic cell HL-7702, lung fibroblast cell WI-38, liver cancer cell BEL-7404 and gastric cancer cell MCG-803. A combination of cell viability assay, immunoblotting, and RNA interference revealed that PS-101 induced EGFR-dependent inhibition selectivity. Further studies showed that PS-101 caused cell cycle arrest at G1 phase, changed cell size, induced apoptosis and led to cell death by increasing the proportion of sub-G1 cells. Molecular mechanism studies suggested that blocking the EGFR-driven antiapoptotic pathway is essential for PS-101-induced apoptosis. The contribution of blocking the EGFR-driven antiapoptotic pathway was verified through examines abundance of likely candidate proteins and RNA interference. The root cause for increase in BAD and decrease in Bcl-2 which altogether initiated caspase-dependent apoptosis were predominantly due to down-regulation the expression of EGFR after PS-101 treatment. PS-101 strongly down-regulated the EGFR expression to trigger proapototic protein BAD increase and antiproapototic protein Bcl-2 decrease, which altogether actived effector caspase-3/9 to initiate cell apoptisis. Taken together, these results suggest that PS-101 may be a potential candidate for cancer therapy against human lung cancer.

Non-apoptotic role of BID in inflammation and innate immunity

Innate immunity is a fundamental defence response that depends on evolutionarily conserved pattern recognition receptors for sensing infections or danger signals. Nucleotide-binding and oligomerization domain (NOD) proteins are cytosolic pattern-recognition receptors of paramount importance in the intestine, and their dysregulation is associated with inflammatory bowel disease. They sense peptidoglycans from commensal microorganisms and pathogens and coordinate signalling events that culminate in the induction of inflammation and anti-microbial responses. However, the signalling mechanisms involved in this process are not fully understood. Here, using genome-wide RNA interference, we identify candidate genes that modulate the NOD1 inflammatory response in intestinal epithelial cells. Our results reveal a significant crosstalk between innate immunity and apoptosis and identify BID, a BCL2 family protein, as a critical component of the inflammatory response. Colonocytes depleted of BID or macrophages from Bid(-/-) mice are markedly defective in cytokine production in response to NOD activation. Furthermore, Bid(-/-) mice are unresponsive to local or systemic exposure to NOD agonists or their protective effect in experimental colitis. Mechanistically, BID interacts with NOD1, NOD2 and the IκB kinase (IKK) complex, impacting NF-κB and extracellular signal-regulated kinase (ERK) signalling. Our results define a novel role of BID in inflammation and immunity independent of its apoptotic function, furthering the mounting evidence of evolutionary conservation between the mechanisms of apoptosis and immunity.