Glycogen synthase kinase 3 beta (GSK3β) is highly inactivated in epithelial cancers and is known to inhibit tumor migration and invasion. The zinc-finger-containing transcriptional repressor, Slug, ...represses E-cadherin transcription and enhances epithelial-mesenchymal transition (EMT). In this study, we find that the GSK3β-pSer9 level is associated with the expression of Slug in non-small cell lung cancer. GSK3β-mediated phosphorylation of Slug facilitates Slug protein turnover. Proteomic analysis reveals that the carboxyl terminus of Hsc70-interacting protein (CHIP) interacts with wild-type Slug (wtSlug). Knockdown of CHIP stabilizes the wtSlug protein and reduces Slug ubiquitylation and degradation. In contrast, nonphosphorylatable Slug-4SA is not degraded by CHIP. The accumulation of nondegradable Slug may further lead to the repression of E-cadherin expression and promote cancer cell migration, invasion and metastasis. Our findings provide evidence of a de novo GSK3β-CHIP-Slug pathway that may be involved in the progression of metastasis in lung cancer.
Critical-sized bone defects are defined as those that will not heal spontaneously within a patient’s lifetime. Current treatment options include vascularized bone grafts, distraction osteogenesis, ...and the induced membrane technique. The induced membrane technique is an increasingly utilized method with favorable results including high rates of union. Tissue engineering holds promise in the treatment of large bone defects due to advancement of stem cell biology, novel biomaterials, and 3D bioprinting. In this review, we provide an overview of the current operative treatment strategies of critical-sized bone defects as well as the current state of tissue engineering for such defects.
MicroRNA in lung cancer LIN, P.-Y; YU, S.-L; YANG, P.-C
British journal of cancer,
10/2010, Letnik:
103, Številka:
8
Journal Article
Recenzirano
Odprti dostop
MicroRNAs (miRNAs) are small non-protein-coding RNAs that function as endogenous negative gene regulators. Dysfunctions of miRNAs are frequently found in malignancies, including lung cancer. In this ...review, we summarise the current understanding of miRNAs in lung cancer tumourigenesis, and highlight their potential in overcoming drug resistance, abetting histological sub-classification techniques, and serving as biomarkers for lung cancer risk stratification and outcome prediction.
Patients with castration-resistant prostate cancer derive only modest clinical benefit from available therapies. Blockade of the inhibitory programmed death 1 (PD-1) receptor by monoclonal antibodies ...has been effective in several malignancies. Results from the prostate adenocarcinoma cohort of the nonrandomized phase Ib KEYNOTE-028 trial of pembrolizumab in advanced solid tumors are presented.
Key eligibility criteria included advanced prostate adenocarcinoma, unsuccessful standard therapy, measurable disease per Response Evaluation Criteria in Solid Tumors, version 1.1 (RECIST v1.1), and PD-1 ligand (PD-L1) expression in ≥1% of tumor or stromal cells. Patients received pembrolizumab 10mg/kg every 2weeks until disease progression or intolerable toxicity for up to 24months. Primary end point was objective response rate (ORR) per RECIST v1.1 by investigator review.
Median patient age in this cohort (n=23) was 65years; 73.9% of patients received at least two prior therapies for metastatic disease. There were four confirmed partial responses, for an ORR of 17.4% 95% confidence interval (CI) 5.0%–38.8%; 8 of 23 (34.8%) patients had stable disease. Median duration of response was 13.5months. Median progression-free survival (PFS) and overall survival (OS) were 3.5 and 7.9months, respectively; 6-month PFS and OS rates were 34.8% and 73.4%, respectively. One patient remained on treatment at data cutoff. After a median follow-up of 7.9months, 14 (60.9%) patients experienced treatment-related adverse events (TRAEs), most commonly nausea (n=3, 13.0%). Four (17.3%) experienced grade 3/4 TRAEs: grade 3 peripheral neuropathy, grade 3 asthenia, grade 3 fatigue, and grade 4 lipase increase. No pembrolizumab-related deaths or discontinuations occurred.
Pembrolizumab resulted in durable objective response in a subset of patients with heavily pretreated, advanced PD-L1–positive prostate cancer, and its side effect profile was favorable.
NCT02054806
Secondary mutation of epidermal growth factor receptor (EGFR) resulting in drug resistance is one of the most critical issues in lung cancer therapy. Several drugs are being developed to overcome ...EGFR tyrosine kinase inhibitor (TKI) resistance. Here, we report that pyruvate kinase M2 (PKM2) stabilized mutant EGFR protein by direct interaction and sustained cell survival signaling in lung cancer cells. PKM2 silencing resulted in markedly reduced mutant EGFR expression in TKI-sensitive or -resistant human lung cancer cells, and in inhibition of tumor growth in their xenografts, concomitant with downregulation of EGFR-related signaling. Mechanistically, PKM2 directly interacted with mutant EGFR and heat-shock protein 90 (HSP90), and thus stabilized EGFR by maintaining its binding with HSP90 and co-chaperones. Stabilization of EGFR relied on dimeric PKM2, and the protein half-life of mutant EGFR decreased when PKM2 was forced into its tetramer form. Clinical levels of PKM2 positively correlated with mutant EGFR expression and with patient outcome. These results reveal a previously undescribed non-glycolysis function of PKM2 in the cytoplasm, which contribute to EGFR-dependent tumorigenesis and provide a novel strategy to overcome drug resistance to EGFR TKIs.
•Venetoclax resistance is mediated by methylation and silencing of PUMA.•Treatment algorithms should consider the PUMA, MCL1, and BAX status.
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The BCL2 inhibitor venetoclax has been ...approved to treat different hematological malignancies. Because there is no common genetic alteration causing resistance to venetoclax in chronic lymphocytic leukemia (CLL) and B-cell lymphoma, we asked if epigenetic events might be involved in venetoclax resistance. Therefore, we employed whole-exome sequencing, methylated DNA immunoprecipitation sequencing, and genome-wide clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein 9 screening to investigate venetoclax resistance in aggressive lymphoma and high-risk CLL patients. We identified a regulatory CpG island within the PUMA promoter that is methylated upon venetoclax treatment, mediating PUMA downregulation on transcript and protein level. PUMA expression and sensitivity toward venetoclax can be restored by inhibition of methyltransferases. We can demonstrate that loss of PUMA results in metabolic reprogramming with higher oxidative phosphorylation and adenosine triphosphate production, resembling the metabolic phenotype that is seen upon venetoclax resistance. Although PUMA loss is specific for acquired venetoclax resistance but not for acquired MCL1 resistance and is not seen in CLL patients after chemotherapy-resistance, BAX is essential for sensitivity toward both venetoclax and MCL1 inhibition. As we found loss of BAX in Richter’s syndrome patients after venetoclax failure, we defined BAX-mediated apoptosis to be critical for drug resistance but not for disease progression of CLL into aggressive diffuse large B-cell lymphoma in vivo. A compound screen revealed TRAIL-mediated apoptosis as a target to overcome BAX deficiency. Furthermore, antibody or CAR T cells eliminated venetoclax resistant lymphoma cells, paving a clinically applicable way to overcome venetoclax resistance.
Two complementary articles shed new light on resistance to venetoclax in lymphoid malignancies. Thijssen et al use single-cell studies to reveal the multilayered nature of the mechanisms underpinning the recurrence of chronic lymphocytic leukemia in patients on long-term venetoclax, identifying a range of recurring genetic and epigenetic changes in apoptotic regulators. Overlying this heterogeneity, heightened expression of MCL1 driven by NF-κB is ubiquitous but reversible upon drug discontinuation. Thomalla and colleagues use B-lineage cell lines and patient samples to elegantly demonstrate how methylation and silencing of PUMA, a pro-apoptotic, causes failure of venetoclax. Both articles provide clinically applicable suggestions for circumventing emergent resistance to venetoclax.
Remodeling of the uterine vasculature by invasive extravillous trophoblasts (EVTs) is a critical aspect of human placentation. Insufficient EVT invasion can lead to severe obstetrical complications ...like preeclampsia, intrauterine growth restriction, and preterm birth. Glial cells missing-1 (GCM1) is a transcription factor that is crucial for proper placentation in mice, and is highly expressed in human syncytiotrophoblast (ST) and EVTs. GCM1 is classically considered a master regulator of ST formation, but little is known about its contribution to the development and function of EVTs. Therefore, in this study we test the hypothesis that GCM1 is a critical regulator of both EVT and ST development and function. We show that GCM1 is highly expressed in human trophoblast stem (TS) cells differentiated into either ST or EVTs. Knockdown of GCM1 in TS cells hindered differentiation into both ST and EVT pathways. When placed in ST media, GCM1-knockdown cells formed small, unstable clusters; when placed in EVT media, cells had altered morphology and transcript profiles resembling cells trapped in an intermediate state between CT and EVT, and invasive capacity through matrix was reduced. RNA sequencing analysis of GCM1-deficient TS cells revealed downregulation of EVT-associated genes and enrichment in transcripts related to WNT signaling, which was linked to decreased expression of the EVT master regulator ASCL2 and the WNT antagonist NOTUM. Our findings reveal an essential role of GCM1 during ST and EVT development, and suggest that GCM1 regulates differentiation of human TS cells into EVTs by inducing expression of ASCL2 and NOTUM.
Major depressive disorder (MDD) is a prevalent mood disorder that is associated with differential prefrontal brain expression patterns. Treatment of MDD includes a variety of biopsychosocial ...approaches. In medical practice, antidepressant drugs are the most common treatment for depressive episodes, and they are among the most prescribed medications in North America. Although antidepressants are clearly effective, particularly for moderate to severe depressive episodes, there is variability in how individuals respond to antidepressant treatment. Failure to respond has individual, economic and social consequences for patients and their families. Several lines of evidence demonstrate that genes are regulated through the activity of microRNAs (miRNAs), which act as fine-tuners and on-off switches of gene expression. Here we report on complementary studies using postmortem human brain samples, cellular assays and samples from clinical trials of patients with depression and show that miR-1202, a miRNA specific to primates and enriched in the human brain, is differentially expressed in individuals with depression. Additionally, miR-1202 regulates expression of the gene encoding metabotropic glutamate receptor-4 (GRM4) and predicts antidepressant response at baseline. These results suggest that miR-1202 is associated with the pathophysiology of depression and is a potential target for new antidepressant treatments.
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