Many tumors become addicted to autophagy for survival, suggesting inhibition of autophagy as a potential broadly applicable cancer therapy. ULK1/Atg1 is the only serine/threonine kinase in the core ...autophagy pathway and thus represents an excellent drug target. Despite recent advances in the understanding of ULK1 activation by nutrient deprivation, how ULK1 promotes autophagy remains poorly understood. Here, we screened degenerate peptide libraries to deduce the optimal ULK1 substrate motif and discovered 15 phosphorylation sites in core autophagy proteins that were verified as in vivo ULK1 targets. We utilized these ULK1 substrates to perform a cell-based screen to identify and characterize a potent ULK1 small molecule inhibitor. The compound SBI-0206965 is a highly selective ULK1 kinase inhibitor in vitro and suppressed ULK1-mediated phosphorylation events in cells, regulating autophagy and cell survival. SBI-0206965 greatly synergized with mechanistic target of rapamycin (mTOR) inhibitors to kill tumor cells, providing a strong rationale for their combined use in the clinic.
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•ULK1 phosphorylates multiple autophagy components, including VPS34 on Ser249•SBI-0206965 is a highly selective ULK1 kinase inhibitor that blocks autophagy•SBI-0206965 combined with starvation or mTOR inhibition leads to ULK1 degradation•SBI-0206965 synergizes with mTOR inhibition to induce cell death
ULK1 is a serine/threonine kinase that initiates autophagy in response to nutrient deprivation. Egan et al. define ULK1’s consensus phosphorylation motif, demonstrate that ULK1 phosphorylates several autophagy components, and develop a ULK1 small molecule inhibitor (SBI-0206965). SBI-0206965 synergizes with mTOR inhibition to enhance apoptosis in tumor cells, suggesting therapeutic opportunities.
We used the RIP1-Tag2 (RT2) mouse model of islet cell carcinogenesis to profile the transcriptome of pancreatic neuroendocrine tumors (PNET) that were either non-invasive or highly invasive, seeking ...to identify pro- and anti-invasive molecules. Expression of multiple components of desmosomes, structures that help maintain cellular adhesion, was significantly reduced in invasive carcinomas. Genetic deletion of one of these desmosomal components, desmoplakin, resulted in increased local tumor invasion without affecting tumor growth parameters in RT2 PNETs. Expression of cadherin 1, a component of the adherens junction adhesion complex, was maintained in these tumors despite the genetic deletion of desmoplakin. Our results demonstrate that loss of desmoplakin expression and resultant disruption of desmosomal adhesion can promote increased local tumor invasion independent of adherens junction status.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
While altered expression of microRNAs (miRs) in tumors has been well documented, it remains unclear how the miR transcriptome intersects neoplastic progression. By profiling the miR transcriptome we ...identified miR expression signatures associated with steps in tumorigenesis and the acquisition of hallmark capabilities in a prototypical mouse model of cancer. Metastases and a rare subset of primary tumors shared a distinct miR signature, implicating a discrete lineage for metastatic tumors. The miR-200 family is strongly down-regulated in metastases and met-like primary tumors, thereby relieving repression of the mesenchymal transcription factor Zeb1, which in turn suppresses E-cadherin. Treatment with a clinically approved angiogenesis inhibitor normalized angiogenic signature miRs in primary tumors, while altering expression of metastatic signature miRs similarly to liver metastases, suggesting their involvement in adaptive resistance to anti-angiogenic therapy via enhanced metastasis. Many of the miR changes associated with specific stages and hallmark capabilities in the mouse model are similarly altered in human tumors, including cognate pancreatic neuroendocrine tumors, implying a generality.
Journal update monthly top five Challen, Kirsty; Ravichandran, Anukiran; Chiu, Matthew Chun Bond ...
Emergency medicine journal,
04/2023, Letnik:
40, Številka:
4
Journal Article
The LKB1 tumor suppressor is often mutationally inactivated in non-small cell lung cancer (NSCLC). LKB1 phosphorylates and activates members of the AMPK family of Ser/Thr kinases. Within this family, ...the salt-inducible kinases (SIKs) modulate gene expression in part via the inhibitory phosphorylation of the CRTCs, coactivators for CREB (cAMP response element-binding protein). The loss of LKB1 causes SIK inactivation and the induction of the CRTCs, leading to the up-regulation of CREB target genes. We identified CRTC2 as a critical factor in LKB1-deficient NSCLC. CRTC2 is unphosphorylated and therefore constitutively activated in LKB1-mutant NSCLC, where it promotes tumor growth, in part via the induction of the inhibitor of DNA binding 1 (ID1), a bona fide CREB target gene. As ID1 expression is up-regulated and confers poor prognosis in LKB1-deficient NSCLC, our results suggest that small molecules that inhibit CRTC2 and ID1 activity may provide therapeutic benefit to individuals with NSCLC.
Abstract
Background
The ultimate goal of anterior cruciate ligament reconstructions (ACLR) is to fulfil the return-to-play (RTP) criteria. Quadriceps muscle strength is one of the key determinants ...for a patient’s successful return-to-play after ACLR. Quadriceps muscle atrophy can persist beyond the completion of the rehabilitation program in almost half the patients and the reason behind this is still unknown. There are emerging evidences showing that pulsed electromagnetic field (PEMF) can modulate mitochondrial activities for muscle gain. PEMF exposure on top of regular exercise training may promote muscle regeneration and tissue healing.
Methods
This is a double-blinded, randomized controlled trial to investigate the effects of PEMF treatment during the postoperative period on quadriceps muscle strength in ACL injured patient. Adult patients (aged 18–30) with a unilateral ACL injury, total quadriceps muscle volume is equal or more than 7% deficit on involved leg compared with uninvolved leg, sporting injury with a Tegner score of 7+, and both knees without a history of injury/prior surgery will be recruited. To estimate the improvement of patients, isokinetic muscle assessment, ultrasound imaging and MRI for quadriceps muscle thickness, self-reported outcomes with questionnaires, KT-1000 for knee laxity and biomechanical analysis, and Xtreme CT for bone mineral density will be performed. To investigate the mechanism of PEMF therapy on increasing quadriceps strength, samples of blood serum will be drawn before and after intervention.
Discussion
This is the first trial evaluating the effects of PEMF on quadriceps muscle recovery after ACLR. The proposed study addresses a huge research gap by evaluating practical use of PEMF as part of rehabilitation. The proposed study will provide much needed scientific support in the use of this noninvasive treatment modality to facilitate recovery of quadriceps strength after PEMF.
Trial registration
ClinicalTrials.gov
NCT05184023. Registered on 5 January 2022
Approximately 30-70% of patients who have undergone allogeneic (allo) hematopoietic stem cell transplantation (HSCT) eventually experience chronic graft-versus-host disease (cGVHD). Patients who ...develop steroid-refractory (SR)-cGVHD are the most severely impacted due to significant disease and financial burden. There remains an unmet need for safe, efficacious, and accessible treatments for these patients. The objective of this study was to determine the cost effectiveness of ruxolitinib for treatment of SR-cGvHD from the Singapore healthcare system perspective.
Based on data from the REACH3 randomized open-label trial, a semi-Markov model was developed to evaluate cost-effectiveness of ruxolitinib compared with investigators' choice of best alternative therapy (BAT) for treatment of patients > 12 years of age with SR-cGVHD in Singapore over a 40-year time horizon. The model only considered direct medical-care costs related to the treatment of SR-cGVHD and reported them in Singapore Dollars (SGD). Half-cycle correction was applied to all costs and outcomes, which were discounted at 3%. Probabilistic sensitivity analysis (PSA), one-way sensitivity analysis (OWSA), and scenario analysis were conducted to explore the drivers of uncertainty in the model.
In the deterministic base case, more life years (LY; 10.28 vs. 9.42) and quality-adjusted life years (QALYs; 7.31 vs. 6.51) were gained with ruxolitinib than BAT at higher costs (SGD 303,214 vs. SGD 302,673) leading to an incremental cost-effectiveness ratio (ICER) of SGD 677/QALY. At a willingness-to-pay threshold of SGD 75,000/QALY gained, PSA found that ruxolitinib had a 78.52% probability of being cost-effective. Findings were sensitive to variations in non-responder utilities in the BAT arm and duration of BAT treatment in the OWSA, or comparison to either methotrexate (MTX) or mycophenolic acid as a single comparator in the scenario analysis. ICERs remained lower than SGD 75,000/QALY in all other tested variations and scenarios.
Ruxolitinib is likely to be cost-effective from Singapore healthcare system's perspective for patients with SR-cGVHD, which is promising in the management of patients with unmet clinical needs.
Recent advances in understanding the altered metabolism of tumor cells are yielding new therapeutic leads. Four new studies that show just how far researchers' understanding of cancer metabolism has ...progressed are discussed, and some of the ways in which this knowledge is being applied to develop innovative therapeutics are highlighted.
Cancer is a disease subject to both genetic and environmental influences. In this study, we used the RIP1-Tag2 (RT2) mouse model of islet cell carcinogenesis to identify a genetic locus that ...influences tumor progression to an invasive growth state. RT2 mice inbred into the C57BL/6 (B6) background develop both noninvasive pancreatic neuroendocrine tumors (PNET) and invasive carcinomas with varying degrees of aggressiveness. In contrast, RT2 mice inbred into the C3HeB/Fe (C3H) background are comparatively resistant to the development of invasive tumors, as are RT2 C3HB6(F1) hybrid mice. Using linkage analysis, we identified a 13-Mb locus on mouse chromosome 17 with significant linkage to the development of highly invasive PNETs. A gene residing in this locus, the anaplastic lymphoma kinase (Alk), was expressed at significantly lower levels in PNETs from invasion-resistant C3H mice compared with invasion-susceptible B6 mice, and pharmacological inhibition of Alk led to reduced tumor invasiveness in RT2 B6 mice. Collectively, our results demonstrate that tumor invasion is subject to polymorphic genetic control and identify Alk as a genetic modifier of invasive tumor growth.
In this study, we evaluated the implementation of a second-tier genetic screening test using an amplicon-based next-generation sequencing (NGS) panel in our laboratory during the period of 1 ...September 2021 to 31 August 2022 for the newborn screening (NBS) of six conditions for inborn errors of metabolism: citrullinemia type II (MIM #605814), systemic primary carnitine deficiency (MIM #212140), glutaric acidemia type I (MIM #231670), beta-ketothiolase deficiency (#203750), holocarboxylase synthetase deficiency (MIM #253270) and 3-hydroxy-3-methylglutaryl-CoA lyase deficiency (MIM # 246450). The custom-designed NGS panel can detect sequence variants in the relevant genes and also specifically screen for the presence of the hotspot variant IVS16ins3kb of
by the copy number variant calling algorithm. Genetic second-tier tests were performed for 1.8% of a total of 22,883 NBS samples. The false positive rate for these six conditions after the NGS second-tier test was only 0.017%, and two cases of citrullinemia type II would have been missed as false negatives if only biochemical first-tier testing was performed. The confirmed true positive cases were citrullinemia type II (
= 2) and systemic primary carnitine deficiency (
= 1). The false positives were later confirmed to be carrier of citrullinemia type II (
= 2), carrier of glutaric acidemia type I (
= 1) and carrier of systemic primary carnitine deficiency (
= 1). There were no false negatives reported. The incorporation of a second-tier genetic screening test by NGS greatly enhanced our program's performance with 5-working days turn-around time maintained as before. In addition, early genetic information is available at the time of recall to facilitate better clinical management and genetic counseling.
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