Citations

AbstractDNA‐binding proteins, including transcription factors (TFs), play essential roles in various cellular processes and pathogenesis of diseases, deeming to be potential therapeutic targets. However, these proteins are generally considered undruggable as they lack an enzymatic catalytic site or a ligand‐binding pocket. Proteolysis‐targeting chimera (PROTAC) technology has been developed by engineering a bifunctional molecule chimera to bring a protein of interest (POI) to the proximity of an E3 ubiquitin ligase, thus inducing the ubiquitination of POI and further degradation through the proteasome pathway. Here, the development of oligonucleotide‐based PROTAC (O'PROTACs), a class of noncanonical PROTACs in which a TF‐recognizing double‐stranded oligonucleotide is incorporated as a binding moiety of POI is reported. It is demonstrated that O'PROTACs of lymphoid enhancer‐binding factor 1 (LEF1) and ETS‐related gene (ERG), two highly cancer‐related transcription factors, successfully promote degradation of these proteins, impede their transcriptional activity, and inhibit cancer cell growth in vitro and in vivo. The programmable nature of O'PROTACs indicates that this approach is also applicable to destruct other TFs. O'PROTACs not only can serve as a research tool but also can be harnessed as a therapeutic arsenal to target DNA binding proteins for effective treatment of diseases such as cancer.

PLEXIND1 is upregulated in several cancers, including pancreatic ductal adenocarcinoma (PDAC). It is an established mediator of semaphorin signaling, and neuropilins are its known coreceptors. Herein, we report data to support the proposal that PLEXIND1 acts as a transforming growth factor beta (TGFβ) coreceptor, modulating cell growth through SMAD3 signaling. Our findings demonstrate that PLEXIND1 plays a pro-tumorigenic role in PDAC cells with oncogenic KRAS (KRASmut). We show in KRASmut PDAC cell lines (PANC-1, AsPC-1,4535) PLEXIND1 downregulation results in decreased cell viability (in vitro) and reduced tumor growth (in vivo). Conversely, PLEXIND1 acts as a tumor suppressor in the PDAC cell line (BxPC-3) with wild-type KRAS (KRASwt), as its reduced expression results in higher cell viability (in-vitro) and tumor growth (in vivo). Additionally, we demonstrate that PLEXIND1-mediated interactions can be selectively disrupted using a peptide based on its C-terminal sequence (a PDZ domain-binding motif), an outcome that may possess significant therapeutic implications. To our knowledge, this is the first report showing that (1) PLEXIND1 acts as a TGFβ coreceptor and mediates SMAD3 signaling, and (2) differential roles of PLEXIND1 in PDAC cell lines correlate with KRASmut and KRASwt status.

Hyperstimulation of the cholecystokinin 1 receptor (CCK1R), a G protein–coupled receptor (GPCR), in pancreatic acinar cells is commonly used to induce pancreatitis in rodents. Human pancreatic acinar cells lack CCK1R but express cholinergic receptor muscarinic 3 (M3R), another GPCR. To test whether M3R activation is involved in pancreatitis, a mutant M3R was conditionally expressed in pancreatic acinar cells in mice. This mutant receptor loses responsiveness to its native ligand, acetylcholine, but can be activated by an inert small molecule, clozapine- N -oxide (CNO). Intracellular calcium and amylase were elicited by CNO in pancreatic acinar cells isolated from mutant M3R mice but not WT mice. Similarly, acute pancreatitis (AP) could be induced by a single injection of CNO in the transgenic mice but not WT mice. Compared with the cerulein-induced AP, CNO caused more widespread acinar cell death and inflammation. Furthermore, chronic pancreatitis developed at 4 weeks after 3 episodes of CNO-induced AP. In contrast, in mice with 3 recurrent episodes of cerulein-included AP, pancreas histology was restored in 4 weeks. Furthermore, the M3R antagonist ameliorated the severity of cerulein-induced AP in WT mice. We conclude that M3R activation can cause the pathogenesis of pancreatitis. This model may provide an alternative approach for pancreatitis research.

AbstractBackgroundCoverage of posterior trunk defects after tumor resection can be challenging due to the intricate anatomy. The keystone perforator island flap (KPIF) provides coverage of the defect without the need for distant flap coverage or microsurgery, matches the recipient's skin color and contour, and requires a short operative time.MethodsA retrospective review of all oncological back reconstructions with KPIF was performed at our institution. The patient comorbidities and surgical outcomes were collected.ResultsA total of 17 patients underwent 20 KPIF (15 single and 2 double) for back reconstruction. Surgical indications were sarcoma (n = 12) and melanoma (n = 5). The mean age at surgery was 47.3 years (SD 23.3). The flaps were located in the upper back (n = 8), paraspinal (n = 4), middle back (n = 6), and lower back (n = 2). The average wound size after sarcoma and melanoma excision were 231.6 ± 297.4 and 156.7 ± 269.7 cm2, respectively. Four patients required an additional planned skin graft and one patient underwent a simultaneous myocutaneous latissimus dorsi flap. The mean operative time, including tumor resection, was 256 min (SD 118). The median length‐of‐hospital stay was 3 days (Q1–3: 1–6.5) and the median follow‐up time was 35.3 months (Q1–3: 13.3–53.1). All flaps survived with minor surgical complications which included hematoma (n = 1), surgical site infection requiring debridement (n = 1), superficial wound dehiscence (n = 1), cellulitis (n = 1), and seroma (n = 1). The reconstructions were successful in 100% of patients.ConclusionsThe KPIF is a reliable and safe option for reconstruction of oncological back defects with minimal perioperative complications. This flap option avoids the use of free flaps and myocutaneous flaps for moderate‐sized back defects.

SummaryZUMA‐1 (NCT02348216) examined the safety and efficacy of axicabtagene ciloleucel (axi‐cel), an autologous CD19‐directed chimaeric antigen receptor (CAR)‐T cell therapy, in refractory large B‐cell lymphoma. To reduce treatment‐related toxicity, several exploratory safety management cohorts were added to ZUMA‐1. Specifically, cohort 6 investigated management of cytokine release syndrome (CRS) and neurologic events (NEs) with prophylactic corticosteroids and earlier corticosteroid and tocilizumab intervention. CRS and NE incidence and severity were primary end‐points. Following leukapheresis, patients could receive optional bridging therapy per investigator discretion. All patients received conditioning chemotherapy (days −5 through −3), 2 × 106 CAR‐T cells/kg (day 0) and once‐daily oral dexamethasone [10 mg, day 0 (before axi‐cel) through day 2]. Forty patients received axi‐cel. CRS occurred in 80% of patients (all grade ≤2). Any grade and grade 3 or higher NEs occurred in 58% and 13% of patients respectively. Sixty‐eight per cent of patients did not experience CRS or NEs within 72 h of axi‐cel. With a median follow‐up of 8·9 months, objective and complete response rates were 95% and 80% respectively. Overall, prophylactic corticosteroids and earlier corticosteroid and/or tocilizumab intervention resulted in no grade 3 or higher CRS, a low rate of grade 3 or higher NEs and high response rates in this study population.

How to catch a dynamic state AMP-activated protein kinase (AMPK) is a key sensor of energy status in eukaryotes. Its dynamic structure is regulated by allosteric factors including phosphorylation and binding of nucleotides and metabolites. Yan et al. developed conformation-specific antibodies that trap AMPK in a fully inactive state that has experienced a large, domain-level rotation. Biophysical experiments in cells and in vitro are consistent with the structural work and support a model in which the activation loop is fully exposed in the completely inactive, dephosphorylated state. These structures inform our understanding of the complex allosteric behavior in this crucial metabolic regulator. Science , abe7565, this issue p. 413

Abstract Purpose: Structural variants (SV) of the MYC gene region are common in multiple myeloma and influence disease progression. However, the prognostic significance of different MYC SVs in multiple myeloma has not been clearly established. Experimental Design: We conducted a retrospective study of multiple myeloma comparing MYC SV subtypes identified by next-generation sequencing (NGS) and FISH to MYC expression and disease survival using 140 cases from Mayo Clinic and 658 cases from the MMRF CoMMpass study. Results: MYC SVs were found in 41% of cases and were classified into nine subtypes. A correlation between the presence of a MYC SV and increased MYC expression was identified. Among the nine MYC subtypes, the non-immunoglobulin (non-Ig) insertion subtype was independently associated with improved outcomes, while the Ig insertion subtype, specifically involving the IgL gene partner, was independently associated with poorer outcomes compared with other MYC SV subtypes. Although the FISH methodology failed to detect approximately 70% of all MYC SVs, those detected by FISH were associated with elevated MYC gene expression and poor outcomes suggesting a different pathogenic role for FISH-detected MYC subtypes compared with other MYC subtypes. Conclusions: Understanding the impact of different MYC SVs on disease outcome is necessary for the reliable interpretation of MYC SVs in multiple myeloma. NGS approaches should be considered as a replacement technique for a more comprehensive evaluation of the multiple myeloma clone.

Abstract Background & Aims: Coronavirus-19 (COVID-19) due to Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-COV-2) is an ongoing global pandemic causing more than three million deaths. Protease inhibitors had been shown to decrease viral entry. However, the role of dabigatran, an inhibitor of multiple proteases, on coronavirus remains unknown.Methods: MRC-5 cells, HCT-8, or Huh-7 cells were infected with Beta-coronavirus OC43 and SARS-CoV-2. Cytopathic effects (CPE) were monitored by imaging. Viral load was measured by quantitative RT-PCR. Viral protein was detected by Western blot.Results: Camostat, a serine protease inhibitor, had no effect on the replication of OC43 and SARS CoV-2 even at higher doses. Dabigatran inhibited replication, viral entry and CPE of OC43 in a dose-dependent manner. Dabigatran and Remdisivir synergistically inhibited OC43 virus replication. Conclusions: Dabigatran may be beneficial in treating SARS-CoV-2 both for anticoagulation and viral replication inhibition need to be evaluated further.

Introduction: β-blockers, including atenolol, are among the most widely prescribed antihypertensive drug classes. However, their use has been associated with hyperglycemia and incident diabetes, which poses concern for prescribers and patients. The Pharmacogenomic Evaluation of Antihypertensive Responses (PEAR) study is a multicenter clinical trial with one of its objectives to identify genetic influences on adverse metabolic events in patients treated with atenolol. Here we report a genomics-metabolomics integrative approach to identify biomarkers associated with atenolol-induced glucose change. Methods: PEAR participants were genotyped using the Illumina Omni 1M-Quad Chip. Metabolite profiles were acquired through GC-TOF-MS. Association between baseline levels of metabolites and glucose change was conducted using a multivariate linear regression model adjusted for age, gender and baseline fasting glucose. Genomics-metabolomics integration included selecting SNPs within genes involved in the synthesis and degradation of top metabolites and testing their effect on glucose change in 234 atenolol-treated Caucasians in PEAR, adjusting for age, gender, baseline glucose and principal components 1 and 2. A false discovery rate (FDR) of .05 was used to adjust for multiple comparisons. Replication of significant SNPs was conducted in an additional 228 participants treated with atenolol in PEAR. Results: Metabolomics analysis revealed 3 metabolites associated with glucose change that passed FDR adjustment. The top metabolite signal was beta-alanine. Increasing levels of baseline beta-alanine was significantly correlated with greater glucose increases after atenolol treatment (p=.0003). A total of 79 SNPs in 12 genes in the beta-alanine pathway were explored. SNP rs2669429 in DPYS was significantly associated with glucose change, after FDR adjustment. We found that G allele carriers had significantly greater glucose change compared with non-carriers (p=.0006; β=+2.76 mg/dL). This finding was successfully replicated in the other 228 patients who received atenolol (p=.04; β=+1.86 mg/dL). Conclusions: These results suggest that beta alanine and DPYS rs2669429 SNP might be an important predictor of atenolol-induced dysglycemia.

Background: Contemporary breast cancer radiotherapy (RT) results in variable cardiac radiation exposure. While cardiomyocytes are radio-resistant, radiation induces coronary microvascular endothelial damage and inflammation which may ultimately lead to myocardial inflammation, ischemia and fibrosis and put patients at risk for heart failure (HF) and particularly, HF with preserved ejection fraction (HFpEF). Methods: Community based (Olmsted County, MN), HF case-control study of contemporary (1999-2014) breast cancer RT patients with CT-based RT planning for precise mean cardiac radiation dose (MCRD) calculation. HF cases (n=66) and controls (n=129) were matched (1:2) for age at RT, HF risk factors, tumor side and chemotherapy use. Matched controls and cases had identical follow-up (index interval). Proportion of HF and clinical characteristics in categories of MCRD were reported (table) and conditional logistic regression was used to estimate the HF odds ratio (OR) associated with MCRD as a continuous variable. Results: Of the 66 HF cases, 46 (70%) had HFpEF and 20 (30%) had HF with reduced ejection fraction (HFrEF). The proportion of patients with HF (any) or HFpEF increased and proportion with HFrEF tended to increase with increasing MCRD. The prevalence of HF risk factors (hypertension, diabetes, coronary disease) at time of RT did not vary by MCRD while left sided tumor, cancer stage and adriamycin use increased with increasing MCRD. The OR per 1 unit increase in log MCRD was 3.71 (1.98, 6.94) for total HF (p<0.001), 4.91 (1.93, 9.09) for HFpEF (p<0.001) and 2.78 (0.91, 8.47) for HFrEF (p=0.07). The mean index interval was 5.0±3.2 years. Conclusion: Cardiac radiation incident to contemporary breast RT increases the risk of HF, and particularly HFpEF over a short post-RT interval. These data may guide use of proton beam therapy in breast cancer. These data also provide support for the role of coronary microvascular compromise in the pathophysiology of HFpEF.