Investigating the Role of MK2 in Head and Neck Squamous Cell Carcinoma Growth, Metastasis and STING Pathway Activation

PURPOSE/OBJECTIVE(S)

Our prior work demonstrated that inhibition of MAPKAPK2 (MK2) can enhance radiation (RT)-mediated in vivo head and neck squamous cell carcinoma (HNSCC) tumor control and survival in preclinical immune incompetent models. The cytosolic DNA sensor cyclic GMP-AMP synthetase (cGAS) and its downstream adaptor protein, stimulator of interferon genes (STING), are conserved proteins within the innate immune signaling pathways and are important for mediating host defense against microbial infection and can play a role in anti-cancer immunity. We hypothesized that loss of MK2 enhances radiation-induced cGAS-STING pathway activation leading to improved tumor control and survival.

MATERIALS/METHODS

MK2 shRNA knockdown human (Tu167, CAL27) and MK2 Cas9/CRISPR knockout (KO) syngeneic murine (Ly2, MLM3) HNSCC cell lines were treated with 10 Gy irradiation. Micronuclei were quantitated by DAPI-immunofluorescence (IF). Protein changes in cGAS-STING were evaluated by immunoblot. Inflammatory cytokine production including Type I IFNβ1 were evaluated by RT-qPCR. Ly2 and MLM3 cells were orthotopically or flank engrafted into immune competent mice (Balb/c, C57Bl/6, respectively) for animal tumor control-survival studies. Tumor immune cell infiltrate was examined using FACS and immunohistochemistry. Selected drug studies using the MK2 inhibitor, ATI-450, were performed with RT.

RESULTS

Loss of MK2 in HNSCC (Tu167, CAL27, Ly2, MLM3) treated with RT led to a significant increase in micronuclei formation compared to control cells. MK2-enhanced micronuclei generation following RT could be inhibited with the actin filament polymerization inhibitor, cytochalasin B. RT treatment of MK2 shRNA cells led to increased cGAS and phospho-STING levels compared to either treatment alone. IFNβ1 levels were significantly higher in HNSCC cell lines treated with RT and with MK2 inhibited by an MK2 inhibitor (ATI-450) or genetic reduction compared to either treatment alone. In-vivo implantation of MLM3 cells into C57Bl/6 comparing control vs MK2 KO tumors treated with ±8 Gy RT demonstrated improved mouse survival favoring RT+MK2 KO over RT, MK2 KO or parental (63, 58, 58.5, 35 days, respectively). FACS analysis of MLM3 WT v KO tumors 3 days post RT showed an overall increase in the number of CD3/CD8 T-cells infiltrating into the tumor in all groups except for parental tumors. Further analysis demonstrated that loss of MK2 reversed CD8 T-cell exhaustion and when combined with radiotherapy led to increased CD8 T-cell activation. Furthermore, activated CD4 and CD8 T cells were reduced in WT+RT cells compared to WT tumors whereas no reduction was seen in the KO or KO+RT.

CONCLUSION

HNSCC tumor MK2 inhibition enhances RT-mediated micronuclei formation and subsequent cGAS-STING-IFNβ1 levels. Loss of HNSCC MK2 leads to increased CD4-CD8 T-cell infiltration into the tumor and this effect is enhanced following RT. Targeting tumor MK2 may facilitate improved tumor control.

A Meta-Model of Chemotherapy Planning in the Multi-Hospital/Multi-Trial-Center-Environment of Pediatric Oncology

Objective: Chemotherapy planning in pediatric oncology is complex and time-consuming. The correctness of the calculation according to state-of-the-art research is crucial for curing the child. Computer-assistance can be of great value. The objective of our research was to work out a meta-model of chemotherapy planning based on the Unified Modeling Language (UML). The meta-model is used for the development of an application system which serves as a knowledge-acquisition tool for chemotherapy protocols in pediatric oncology as well as for providing protocol-based care.

Methods: We applied evolutionary prototyping, software re-engineering techniques and grounded theory, a qualitative method in social research. We repeated the following steps several times over the years: Based on a requirements analysis (i) a meta-model was developed or adapted, respectively (ii). The meta-model served as a basis for implementing evolutionary prototypes (iii). Further requirements were identified (i) from clinical use of the systems.

Results: We developed a comprehensive UML-based meta-model for chemotherapy planning in pediatric oncology (chemoMM). We implemented it and introduced evolutionary prototypes (CATIPO and DOSPO) in several medical centers. Systematic validation of the prototypes enabled us to derive a final meta-model which covers the requirements that have turned out to be necessary in clinical routine.

Conclusions: We have developed an application system that fits well into clinical routine of pediatric oncology in Germany. Validation results have shown that the implementation of the meta-model chemoMM can adequately support the knowledge acquisition process for protocol-based care.

COX2 expression, angiogenesis, proliferation and survival in Barrett's cancer

OBJECTIVES

To examine COX2 expression and its relation to angiogenesis, Ki67 and Bcl2 expression in Barrett's cancer.

METHODS

Specimens from 48 R0-resected Barrett's adenocarcinoma were immunostained for cyclooxygenase 2 (COX2), CD 31 and alpha-sm actin to discriminate between mature and immature vessels, Mib-1 and Bcl2. COX2 staining, angiogenesis, Ki67 expression and Bcl2 expression were also measured.

RESULTS

COX2 expression was increased in 25 of 48 cases. There was no significant correlation between COX2 expression and age, sex and tumor differentiation. A significant association was found between lymph node positive cases and elevated COX2 expression (p=0.008). The percentage of Ki67 positive cancer cells was 43.8% (range 15.4-67.5%) in the low COX2 group and 57.8% (range 12.0-84.6%) in the high COX2 group. The difference was statistically significant (p=0.046). The median neovascularisation coefficient in the low COX2 group was 11.68 (range 8.22-43.64) and 25.47 (range 8-38.3) in the high COX2 group. The difference was statistically significant (p=0.012). A significant difference in survival was observed between patients in the COX2 low category when compared with the COX2 high category (log-rank test p=0.013).

CONCLUSIONS

Elevated COX2 expression is associated with lymph-node metastases and reduced survival in Barrett's cancer. This appears to be related to the induction of angiogenesis and proliferation.

A meta-model of chemotherapy planning in the multi-hospital/multi-trial-center-environment of pediatric oncology

OBJECTIVE

Chemotherapy planning in pediatric oncology is complex and time-consuming. The correctness of the calculation according to state-of-the-art research is crucial for curing the child. Computer-assistance can be of great value. The objective of our research was to work out a meta-model of chemotherapy planning based on the Unified Modeling Language (UML). The meta-model is used for the development of an application system which serves as a knowledge-acquisition tool for chemotherapy protocols in pediatric oncology as well as for providing protocol-based care.

METHODS

We applied evolutionary prototyping, software reengineering techniques and grounded theory, a qualitative method in social research. We repeated the following steps several times over the years: Based on a requirements analysis (i) a meta-model was developed or adapted, respectively (ii). The meta-model served as a basis for implementing evolutionary prototypes (iii). Further requirements were identified (i) from clinical use of the systems.

RESULTS

We developed a comprehensive UML-based meta-model for chemotherapy planning in pediatric oncology (chemoMM). We implemented it and introduced evolutionary prototypes (CATIPO and DOSPO) in several medical centers. Systematic validation of the prototypes enabled us to derive a final meta-model which covers the requirements that have turned out to be necessary in clinical routine.

CONCLUSIONS

We have developed an application system that fits well into clinical routine of pediatric oncology in Germany. Validation results have shown that the implementation of the meta-model chemoMM can adequately support the knowledge acquisition process for protocol-based care.

Stable and long-lasting immune response in horses after DNA vaccination against equine arteritis virus

Equine arteritis virus (EAV) is the causative agent of the equine viral arteritis. It is a small RNA virus with a linear, non-segmented plus RNA genome. EAV is a member of the Arteriviridae family that includes porcine reproductive and respiratory syndrome virus (PRSSV), simian haemorrhagic fever virus (SHFV) and lactate dehydrogenase virus (LDV). The viral transmission is via respiratory and reproductive routes. Clinical signs in horses vary, and severe infection can lead to abortions in pregnant mares or neonatal foal death. The aim of this study was to investigate the development of the immune response in horses after immunization with a DNA vaccine harbouring and expressing EAV Open Reading Frames (ORF) 2, 5, and 7, in combination with equine interleukin 2 (eqIL2). Three boosters followed the basic immunization in two-week intervals. Each immunization was a combination of gene gun and intramuscular injection. All horses developed a high titer of neutralizing antibodies after basic immunization within 2 weeks. Remarkably, this immune response was found to be independent of the age of animals. The youngest horse was six-years old, and the oldest twenty-two years old. A remarkable difference in the immune response between the young and old were not observed. The duration of immunity was investigated during a period of one year. After 12 months, neutralizing antibodies were still detectable in all the vaccinated horses.

Use of desmopressin and erythropoietin in an anaemic Jehovah's Witness patient with severely impaired coagulation capacity undergoing stentless aortic valve replacement

Cardiac surgery in Jehovah's Witness patients remains a challenge in the presence of concomitant congenital or acquired coagulation disorders and anaemia. We report a case of a 66-year-old female Jehovah's Witness suffering from severe calcified aortic valve stenosis requiring aortic valve replacement. The anaemic patient suffered from concomitant platelet dysfunction and deficiency of factors V and VII due to gammopathy of immunoglobulin G. The patient was preoperatively treated with recombinant erythropoietin in combination with folic acid and iron, which resulted in an increase of the haematocrit from 0.335 to 0.416 after 22 days of treatment. Haemostasis was improved by high dose aprotinin and additional desmopressin, which could be demonstrated to be effective by a preoperative test. The patients intra- and postoperative course was uneventful, her total chest tube loss was 130 ml, and she was able to be discharged without the need of any blood transfusions. The beneficial properties of erythropoietin and desmopressin in Jehovah's Witness patients are discussed.

Comorbid anxiety and affective disorder in alcohol-dependent patients seeking treatment: the first Multicentre Study in Germany

The goals of this study were to describe demographic variables, drinking history, and the 6-month prevalence of Axis I comorbidity among alcohol-dependent subjects in GERMANY: The variables: amount of alcohol consumption, age at onset of the first alcohol consumed, age at onset of daily alcohol consumption, age at onset of withdrawal symptoms and number of detoxifications were related to the different comorbid disorders and gender. In this study, 556 patients from 25 alcohol treatment centres were enrolled between 1 January 1999 and 30 April 1999. After a minimum of 10 days of sobriety patients who fulfilled ICD-10 and DSM-IV criteria of alcohol dependence were interviewed for data collection using the Mini-DIPS (German version of the Anxiety Disorders Interview Schedule) and a standardized psychosocial interview. The 6-month prevalence of comorbid Axis I disorders was 53.1%. Among the patients with comorbidity, affective and anxiety disorders were most frequent. Comorbid stress disorder was associated with an early start of drinking, an early beginning of withdrawal symptoms, highest number of detoxifications, and the highest amount of alcohol consumed. Female patients with anxiety disorder consumed more alcohol and started earlier than females without this comorbid disorder. The data do not answer the question of the pathogenesis of comorbid disorders and alcoholism, but indicate that stress disorders in alcoholic patients and anxiety disorders in female alcoholics influence the course and severity of alcoholism.

Safety and feasibility of a cardiac support device

The Cardiac Support Device (CSD), a preformed-knitted polyester device surgically placed over the cardiac ventricles, prevents left ventricular (LV) remodeling and improves LV ejection fraction (EF) in dogs with heart failure (HF). This study was designed to examine the safety of the CSD in patients with advanced HF. As of December 31, 1999, the CSD was implanted into 22 patients with myocardial disease. Ten patients had concomitant mitral valve repair, two patients had valve replacement (one patient aortic and one patient mitral), one patient had LV assist device (LVAD) placement, and eight patients received only the CSD. The CSD was placed while on bypass with the heart beating, attached to the epicardium groove, and tailored anteriorly to snugly fit the ventricles. There were no intraoperative deaths or complications. Two patients died early from non-CSD-related causes 4 and 23 days postoperatively; one late death occurred. Of the remaining 19 patients, none had any CSD-related adverse events during an average 3.5 +/- 0.4 month follow-up. All patients had completed 3-month follow-up. No patients had evidence of constrictive and/or restrictive physiology. Mitral valve regurgitation (MVR) improved in all patients. [table: see text] Initial findings indicate that the CSD is safe and improves heart failure symptoms and LV function. Additional studies and longer follow-up are needed to confirm these results.

Determinants of translocation and folding of TreF, a trehalase of Escherichia coli

One isoform of trehalase, TreF, is present in the cytoplasm and a second, TreA, in the periplasm. To study the questions of why one enzyme is exported efficiently and the other is not and whether these proteins can fold in their nonnative cellular compartment, we fused the signal sequence of periplasmic TreA to cytoplasmic TreF. Even though this TreF construct was exported efficiently to the periplasm, it was not active. It was insoluble and degraded by the periplasmic serine protease DegP. To determine why TreF was misfolded in the periplasm, we isolated and characterized Tre(+) revertants of periplasmic TreF. To further characterize periplasmic TreF, we used a genetic selection to isolate functional TreA-TreF hybrids, which were analyzed with respect to solubility and function. These data suggested that a domain located between residues 255 and 350 of TreF is sufficient to cause folding problems in the periplasm. In contrast to TreF, periplasmic TreA could fold into the active conformation in its nonnative cellular compartment, the cytoplasm, after removal of its signal sequence.

A temperature-dependent switch from chaperone to protease in a widely conserved heat shock protein

Misfolding or unfolding of polypeptides can occur as a consequence of environmental stress and spontaneous mutation. The abundance of general chaperones and proteases suggests that cells distinguish between proteins that can be refolded and "hopeless" cases fated to enter the proteolytic pathway. The mechanisms controlling this key metabolic decision are not well understood. We show here that the widely conserved heat shock protein DegP (HtrA) has both general molecular chaperone and proteolytic activities. The chaperone function dominates at low temperatures, while the proteolytic activity is present at elevated temperatures. These results show that a single cellular factor can switch between two key pathways, controlling protein stability and turnover. Implications of this finding for intracellular protein metabolism are discussed.

Biochemical characterization and mass spectrometric disulfide bond mapping of periplasmic alpha-amylase MalS of Escherichia coli

Periplasmic alpha-amylase of Escherichia coli, the malS gene product, hydrolyzes linear maltodextrins. The purified enzyme exhibited a Km of 49 microM and a Vmax of 0.36 micromol of p-nitrophenylhexaoside hydrolyzed per min per mg of protein. Amylase activity was optimal at pH 8 and was dependent on divalent cations such as Ca2+. MalS exhibited altered migration on SDS-polyacrylamide gel electrophoresis under nonreducing conditions. Analytical ultracentrifugation and electrospray mass spectrometry indicated that MalS is monomeric. The four cysteine residues are involved in intramolecular disulfide bonds. To map disulfide bonds, MalS was proteolytically digested. The resulting peptides were separated by reverse phase-high performance liquid chromatography, and matrix-assisted laser desorption/ionization mass spectrometry analysis indicated the presence of two disulfide bonds, i.e. Cys40-58 and Cys104-520. The disulfide bond at Cys40-58 is located in an N-terminal extension of about 160 amino acids which has no homology to other amylases but to the proposed peptide binding domain of GroEL, the Hsp60 of E. coli. The N-terminal extension is linked to the C-terminal amylase domain via disulfide bond Cys104-520. Reduction of disulfide bonds by dithiothreitol treatment led to aggregation suggesting that the N terminus of MalS may represent an internal chaperone domain.

Targeting of signal sequenceless proteins for export in Escherichia coli with altered protein translocase

Most extracytoplasmic proteins are synthesized with an N-terminal signal sequence that targets them to the export apparatus. Escherichia coli prlA mutants (altered in the secY gene) are able to export cell envelope proteins lacking any signal sequence. In order to understand how such proteins are targeted for export, we isolated mutations in a signal sequenceless version of alkaline phosphatase that block its export in a prlA mutant. The mutations introduce basic amino acyl residues near the N-terminus of alkaline phosphatase. These changes do not disrupt an N-terminal export signal in this protein since the first 25 amino acids can be removed without affecting its export competence. These findings suggest that signal sequenceless alkaline phosphatase does not contain a discrete domain that targets it for export and may be targeted simply because it remains unfolded in the cytoplasm. We propose that basic amino acids near the N-terminus of a signal sequenceless protein affect its insertion into the translocation apparatus after it has been targeted for export. These findings allow the formulation of a model for the entry of proteins into the membrane-embedded export machinery.

Rapid diagnosis of acute mumps infection by a direct immunoglobulin M antibody capture enzyme immunoassay with labeled antigen

A new immunoglobulin M (IgM) antibody capture enzyme immunoassay with peroxidase-labeled mumps antigen (dMACEIA) is described, and its suitability for practical diagnosis of acute mumps infection is evaluated. All 54 patients with proven mumps infection that were tested showed mumps-specific IgM antibodies. On the other hand, no specific IgM antibodies were present in 16 cases of suspected mumps that could not be confirmed by classical complement fixation serology, and IgM mumps virus antibodies could be detected neither in the sera of 100 healthy individuals nor in those of 16 patients positive for rheumatoid factor. In all, 22 children with acute respiratory illness caused by parainfluenza virus and 44 patients with infections due to other viruses showed no IgM response in mumps dMACEIA. The particular characteristic in which complement fixation antibodies against mumps nucleocapsids appear before and disappear earlier than antibodies to the enveloped mumps virus could not be demonstrated in the dMACEIA. In an extensive epidemic of mumps virus infection, the dMACEIA gave a clear diagnosis of mumps infection in 200 out of 371 suspected cases. By day 2 of the illness, 71% of the patients had detectable IgM, and by day 3, all of them had detectable IgM. In 99% of the cases, dMACEIA gave a positive result in the first available serum specimens, most of which were negative for complement fixation antibodies. A positive but only moderate correlation was thus observed between the two serological procedures. IgM antibodies persisted for at least 6 weeks. The dMACEIA, performed in 3 h, offers a reliable, simple, and rapid alternative to routine methods for detection of acute mumps infection.

Effect of p-nitrophenyl diazonium fluoroborate on cholinergic mechanisms

Electrophysiological experiments were done to investigate the effect o p-nitrophenyl diazonium fluoroborate (p-NPD) on motor endplates of the frog's m. cutaneus pectoris. The compound has no direct depolarizing effect on the postsynaptic membrane and stabilizes it irreversibly when added to the bath. Longtime iontophoretical applications of p-NPD produce a biphasic effect: initially a potentiation of the depolarizations due to acetylcholine (ACh) (both iontophoretically applied and presynaptically liberated), and subsequently an inhibition of the response to ACh. When the acetylcholinesterase (AChE) is inactivated previously, only the inhibiting effect of the compound is demonstrable. The association constant of p-NPD to purified AChE and to membrane fragments of electroplax was determined by biochemical methods. The compound's affinity to the AChE was found to be about 20 times greater than to the acetylcholine receptor (AChR). Iontophoretical application of p-NPD to cholinergic neurons in the hippocampal cortex of the cat also produced the characteristic biphasic effect on ACh-induced activity of these investigated neurons. The results suggest that the biphasic effect depends on the capacity of p-NPD to combine with both the AChE and the AChR. The AChE is first inhibited with low concentrations thereby potentiating the ACh response. At higher concentrations the AChR's are progressively inhibited too, thereby diminishing the excitability of the postsynaptic membrane up to a complete block.