Role of Prolonged Intubation in Vocal Fold Motion Impairment in Critically Ill Patients.

OBJECTIVE: COVID-19 upsurge in orotracheal intubation (OTI) has opened a new opportunity for studying associated complications. Vocal fold motion impairment (VFMI) is a known complication of OTI. The present study sought to determine the impact of OTI and prolonged OTI on the risk of developing VFMI; to identify both risk and protective factors associated with it. STUDY DESIGN: Retrospective cohort study. SETTING: Multicenter. METHODS: Medical charts were reviewed for all patients that received invasive mechanical ventilation with a subsequent flexible laryngoscopic assessment between March 2020 and March 2022. The main outcomes were the presence of VFMI, including immobility (VFI) and hypomobility (VFH). RESULTS: A total of 155 patients were included, 119 (76.8%) COVID-19 and 36 (23.2%) non-COVID-19 patients; overall 82 (52.9%) were diagnosed with VFMI. Eighty (52.3%) patients underwent a tracheostomy. The median (IQR) intubation duration was 18 (11-24.25) days, while the median (IQR) time to tracheostomy was 22 (16-29). In the adjusted model, we observed there was a 68% increased risk for VFMI from day 21 of intubation (RR: 1.68; 95% CI 1.07-2.65; P = 0.025). CONCLUSIONS: VFMI is a frequent complication in severely ill patients that undergo intubation. A prolonged OTI was associated with an increased risk of VFMI, highlighting the importance of timely tracheostomy. Further research is needed to confirm these findings in other subsets of critically ill patients.

[Double aortic arch and aortotracheal fistula as cause of fatal massive bleeding: a rare and dangerous association]. / Doble arco aórtico y fistula aortotraqueal como causa de hemorragia masiva fatal: una asociación rara y peligrosa.

Vascular rings are unusual congenital malformations. Among them, double aortic arch (DAA) is often difficult to diagnose due to its low incidence of symptoms. DAA can be associated with tracheal or esophageal compression and, in severe cases, could require tracheal intubation or chronic use of a nasogastric tube. This scenario favors the development of aortotracheal fistulas (ATF) or aortoe-sophageal fistulas (AEF). OBJECTIVE: To present a clinical case with an unusual association of DAA with ATF and to reinforce the importance of maintaining high diagnostic suspicion in patients with massive aerodigestive bleeding without an obvious source. CLINICAL CASE: A 32-week preterm newborn who required prolonged mechanical ventilation and presented intermittent episodes of massive oropharyngeal bleeding with hemodynamic compromise associated with lower airway obstruction without pulmonary hemorrhage. The patient underwent upper endoscopy and exploratory laparotomy without evidence of bleeding. Flexible nasopharyngolaryngoscopy and direct laryngoscopy also showed no abnormalities. A CT angiography showed complete DAA with indentation of the left dominant arch over the trachea, without severe stenosis or evidence of a fistula. AEF was suspected, so exploratory surgery was considered. However, the patient died before surgery due to a massive pulmonary hemorrhage. The autopsy revealed the presence of ATF. CONCLUSIONS: In patients with massive aerodigestive bleeding without an obvious source, the presence of DAA and possible AEF/ ATF should be considered. Imaging studies have a poor performance for this diagnosis, so surgery should be considered for diagnosis and treatment in these patients.

Hospital-based proton therapy implementation during the COVID pandemic: early clinical and research experience in a European academic institution.

INTRODUCTION: A rapid deploy of unexpected early impact of the COVID pandemic in Spain was described in 2020. Oncology practice was revised to facilitate decision-making regarding multimodal therapy for prevalent cancer types amenable to multidisciplinary treatment in which the radiotherapy component searched more efficient options in the setting of the COVID-19 pandemic, minimizing the risks to patients whilst aiming to guarantee cancer outcomes. METHODS: A novel Proton Beam Therapy (PBT), Unit activity was analyzed in the period of March 2020 to March 2021. Institutional urgent, strict and mandatory clinical care standards for early diagnosis and treatment of COVID-19 infection were stablished in the hospital following national health-authorities' recommendations. The temporary trends of patients care and research projects proposals were registered. RESULTS: 3 out of 14 members of the professional staff involved in the PBR intra-hospital process had a positive test for COVID infection. Also, 4 out of 100 patients had positive tests before initiating PBT, and 7 out of 100 developed positive tests along the weekly mandatory special checkup performed during PBT to all patients. An update of clinical performance at the PBT Unit at CUN Madrid in the initial 500 patients treated with PBT in the period from March 2020 to November 2022 registers a distribution of 131 (26%) pediatric patients, 63 (12%) head and neck cancer and central nervous system neoplasms and 123 (24%) re-irradiation indications. In November 2022, the activity reached a plateau in terms of patients under treatment and the impact of COVID pandemic became sporadic and controlled by minor medical actions. At present, the clinical data are consistent with an academic practice prospectively (NCT05151952). Research projects and scientific production was adapted to the pandemic evolution and its influence upon professional time availability. Seven research projects based in public funding were activated in this period and preliminary data on molecular imaging guided proton therapy in brain tumors and post-irradiation patterns of blood biomarkers are reported. CONCLUSIONS: Hospital-based PBT in European academic institutions was impacted by COVID-19 pandemic, although clinical and research activities were developed and sustained. In the post-pandemic era, the benefits of online learning will shape the future of proton therapy education.

Endothelin-converting enzyme-1c promotes stem cell traits and aggressiveness in colorectal cancer cells.

Endothelin-1 is a mitogenic peptide that activates several proliferation, survival, and invasiveness pathways. The effects of endothelin-1 rely on its activation by endothelin-converting enzyme-1 (ECE1), which is expressed as four isoforms with different cytoplasmic N termini. Recently, isoform ECE1c has been suggested to have a role in cancer aggressiveness. The N terminus of ECE1c is phosphorylated by protein kinase CK2 (also known as casein kinase 2), and this enhances its stability and promotes invasiveness in colorectal cancer cells. However, it is not known how phosphorylation improves stability and why this is correlated with increased aggressiveness. We hypothesized that CK2 phosphorylation protects ECE1c from N-terminal ubiquitination and, consequently, from proteasomal degradation. Here, we show that lysine 6 is the bona fide residue involved in ubiquitination of ECE1c and its mutation to arginine (ECE1cK6R ) significantly impairs proteasomal degradation, thereby augmenting ECE1c stability, even in the presence of the CK2 inhibitor silmitasertib. Furthermore, colorectal cancer cells overexpressing ECE1cK6R displayed enhanced cancer stem cell (CSC) traits, including increased stemness gene expression, chemoresistance, self-renewal, and colony formation and spheroid formation in vitro, as well as enhanced tumor growth and metastasis in vivo. These findings suggest that CK2-dependent phosphorylation enhances ECE1c stability, promoting an increase in CSC-like traits. Therefore, phospho-ECE1c may be a biomarker of poor prognosis and a potential therapeutic target for colorectal cancer.

Colon cancer cell invasion is promoted by protein kinase CK2 through increase of endothelin-converting enzyme-1c protein stability.

Endothelin-converting enzyme-1c (ECE-1c) is a membrane metalloprotease involved in endothelin-1 synthesis, which has been shown in vitro to have a role in breast, ovary and prostate cancer cell invasion. N-terminal end of ECE-1c displays three putative phosphorylation sites for the protein kinase CK2. We studied whether CK2 phosphorylates N-terminal end of ECE-1c as well as whether this has a role in migration and invasion of colon cancer cells. CK2 phosphorylated the N-terminal end of ECE-1c and this was precluded upon inhibition of CK2. Inhibition also led to diminished protein levels of both endogen ECE-1 or GFP-fused N-terminal end of ECE-1c in 293T embryonic and DLD-1 colon cancer cells, which highlighted the importance of this motif on UPS-dependent ECE-1c degradation. Full-length ECE-1c mutants designed either to mimic or abrogate CK2-phosphorylation displayed increased or decreased migration/invasion of colon cancer cells, respectively. Moreover, ECE-1c overexpression or its silencing with a siRNA led to increased or diminished cell migration/invasion, respectively. Altogether, these data show that CK2-increased ECE-1c protein stability is related to augmented migration and invasion of colon cancer cells, shedding light on a novel mechanism by which CK2 may promote malignant progression of this disease.

Protein kinase CK2 promotes cancer cell viability via up-regulation of cyclooxygenase-2 expression and enhanced prostaglandin E2 production.

Augmented expression of protein kinase CK2 is associated with hyperproliferation and resistance to apoptosis in cancer cells. Effects of CK2 are at least partially linked to signaling via the Wnt/ß-catenin pathway, which is dramatically enhanced in colon cancer. Cyclooxygenase-2 (COX-2), a Wnt/ß-catenin target gene, has been associated with enhanced cancer progression and metastasis. However, the possibility that a connection may exist between CK2 and COX-2 has not been explored previously. Here we investigated changes in COX-2 expression and activity upon CK2 modulation and evaluated how these changes affected cell viability. COX-2 expression and cell viability decreased upon selective inhibition of COX-2 with SC-791 or CK2 with 2-dimethylamino-4,5,6,7-tetrabromo-1H-benzimidazole (DMAT), both in human colon (HT29-ATCC, HT29-US, DLD-1) and breast (ZR-75) cancer cells, as well as in human embryonic kidney (HEK-293T) cells. On the other hand, ectopic CK2α expression promoted up-regulation of COX-2 by activating the Wnt/ß-catenin pathway in HEK-293T cells. Noteworthy, over-expression of either CK2α, ß-catenin or COX-2, as well as supplementation of the medium with prostaglandin E2 (PGE2), all were individually sufficient to overcome limitations in cell viability triggered by CK2 inhibition either upon addition of DMAT or over-expression of a dominant negative CK2α variant. Altogether, these findings provide new insight to the role of CK2 in cancer by up-regulating COX-2 expression and thereby PGE2 production.

CK2 functionally interacts with AKT/PKB to promote the ß-catenin-dependent expression of survivin and enhance cell survival.

ß-Catenin is crucial in the canonical Wnt signaling pathway. This pathway is up-regulated by CK2 which is associated with an enhanced expression of the antiapoptotic protein survivin, although the underlying molecular mechanism is unknown. AKT/PKB kinase phosphorylates and promotes ß-catenin transcriptional activity, whereas CK2 hyperactivates AKT by phosphorylation at Ser129; however, the role of this phosphorylation on ß-catenin transcriptional activity and cell survival is unclear. We studied in HEK-293T cells, the effect of CK2-dependent hyperactivation of AKT on cell viability, as well as analyzed ß-catenin subcellular localization and transcriptional activity and survivin expression. CK2α overexpression led to an augmented ß-catenin-dependent transcription and protein levels of survivin, and consequently an enhanced resistance to apoptosis. However, CK2α-enhancing effects were reversed when an AKT mutant deficient in Ser129 phosphorylation by CK2 was co-expressed. Therefore, our results strongly suggest that CK2α-specific enhancement of ß-catenin transcriptional activity as well as cell survival may depend on AKT hyperactivation by CK2.

Phosphorylation of AKT/PKB by CK2 is necessary for the AKT-dependent up-regulation of ß-catenin transcriptional activity.

ß-Catenin is a key protein in the canonical Wnt signaling pathway and in many cancers alterations in transcriptional activity of its components are observed. This pathway is up-regulated by the protein kinase CK2, but the underlying mechanism of this change is unknown. It has been demonstrated that CK2 hyperactivates AKT/PKB by phosphorylation at Ser129, and AKT phosphorylates ß-catenin at Ser552, which in turn, promotes its nuclear localization and transcriptional activity. However, the consequences of CK2-dependent hyperactivation of AKT on ß-catenin activity and cell viability have not been evaluated. We assessed this regulatory process by manipulating the activity of CK2 and AKT through overexpression of wild-type, constitutively active and dominant negative forms of these proteins as well as analyzing ß-catenin-dependent transcriptional activity, survivin expression and viability in HEK-293T cells. We observed that CK2α overexpression up-regulated the ß-catenin transcriptional activity, which correlated to an increased nuclear localization of ß-catenin as well as survivin expression. Importantly, these effects were strongly reversed when an AKT-S129A mutant was co-expressed in the same cells, followed by a significant decrease in cell viability but no changes in ß-catenin stability. Taken together, the data suggest that the CK2α-dependent up-regulation of ß-catenin activity requires phosphorylation of AKT in human embryonic kidney cells.

The expression of syndecan-1 and -2 is associated with Gleason score and epithelial-mesenchymal transition markers, E-cadherin and beta-catenin, in prostate cancer.

The epithelial-mesenchymal transition (EMT) is considered a key step in tumor progression, where the invasive cancer cells change from epithelial to mesenchymal phenotype. During this process, a decrease or loss in adhesion molecules expression and an increase in migration molecules expression are observed. The aim of this work was to determine the expression and cellular distribution of syndecan-1 and -2 (migration molecules) and E-cadherin and beta-catenin (adhesion molecules) in different stages of prostate cancer progression. A quantitative immunohistochemical study of these molecules was carried out in tissue samples from benign prostatic hyperplasia and prostate carcinoma, with low and high Gleason score, obtained from biopsies archives of the Clinic Hospital of the University of Chile and Dipreca Hospital. Polyclonal specific antibodies and amplification system of estreptavidin-biotin peroxidase and diaminobenzidine were used. Syndecan-1 was uniformly expressed in basolateral membranes of normal epithelium, changing to a granular cytoplasmatic expression pattern in carcinomas. Syndecan-2 was observed mainly in a cytoplasmatic granular pattern, with high immunostaining intensity in areas of low Gleason score. E-cadherin was detected in basolateral membrane of normal epithelia showing decreased expression in high Gleason score samples. beta-Catenin was found in cell membranes of normal epithelia changing its distribution toward the nucleus and cytoplasm in carcinoma samples. We concluded that changes in expression and cell distribution of E-cadherin and beta-catenin correlated with the progression degree of prostate adenocarcinoma, suggesting a role of these molecules as markers of progression and prognosis. Furthermore, changes in the pattern expression of syndecan-1 and -2 indicate that both molecules may be involved in the EMT and tumor progression of prostate cancer.

Emergence of chronic myelogenous leukemia in a patient with primary thrombocythemia and absence of BCR/ABL rearrangement.

A 65-year-old woman presented with clinical features of primary thrombocythemia (PT), and absence of the BCR/ABL fusion gene. She responded to hydroxyurea treatment, although after 1 year she required progressive increases in the dose. Six years later, she maintained a high platelet count despite hydroxyurea at 2 g/day and treatment was changed to anagrelide. After 3 weeks, both platelet and leukocyte counts increased. A karyotype study detected the Philadelphia chromosome in all of the 24 metaphases studied. Fluorescent in situ hybridization (FISH) analysis revealed the BCR/ABL rearrangement. The patient was treated with imatinib mesylate and achieved a normal platelet and leukocyte count in 3 weeks. Patients presenting clinical features of PT expressing the Ph chromosome or the BCR/ABL fusion gene have been well documented but, to our knowledge, this is the first report of evolution from typical PT to chronic myeloid leukemia.

Chromosome 21 tandem repetition and AML1 (RUNX1) gene amplification.

In two patients with hematological neoplasias a tandem repetition of chromosome 21 in the bone marrow was revealed by cytogenetic analysis. The disease was different in the two patients: one was of the lymphoid type, acute lymphoblastic leukemia type L1, and the other was of the myeloid type, acute nonlymphoblastic leukemia type M2. In one case this chromosomal abnormality resulted in amplification of the AML1 gene (HUGO nomenclature: RUNX1), whereas in the other case the AML1 gene was not included in the tandem repetition, showing that apparently similar cytogenetic aberrations may be different at the molecular level.