OX40 and 4-1BB delineate distinct immune profiles in sarcoma.

Systemic relapse after radiotherapy and surgery is the major cause of disease-related mortality in sarcoma patients. Combining radiotherapy and immunotherapy is under investigation as a means to improve response rates. However, the immune contexture of sarcoma is understudied. Here, we use a retrospective cohort of sarcoma patients, treated with neoadjuvant radiotherapy, and TCGA data. We explore therapeutic targets of relevance to sarcoma, using genomics and multispectral immunohistochemistry to provide insights into the tumor immune microenvironment across sarcoma subtypes. Differential gene expression between radioresponsive myxoid liposarcoma (MLPS) and more radioresistant undifferentiated pleomorphic sarcoma (UPS) indicated UPS contained higher transcript levels of a number of immunotherapy targets (CD73/NT5E, CD39/ENTPD1, CD25/IL2RA, and 4-1BB/TNFRSF9). We focused on 4-1BB/TNFRSF9 and other costimulatory molecules. In TCGA data, 4-1BB correlated to an inflamed and exhausted phenotype. OX40/TNFRSF4 and 4-1BB/TNFRSF9 were highly expressed in sarcoma subtypes versus other cancers. Despite OX40 and 4-1BB being described as Treg markers, we identified that they delineate distinct tumor immune profiles. This was true for sarcoma and other cancers. While only a limited number of samples could be analyzed, spatial analysis of OX40 expression identified two diverse phenotypes of OX40+ Tregs, one associated with and one independent of tertiary lymphoid structures (TLSs). Patient stratification is of intense interest for immunotherapies. We provide data supporting the viewpoint that a cohort of sarcoma patients, appropriately selected, are promising candidates for immunotherapies. Spatial profiling of OX40+ Tregs, in relation to TLSs, could be an additional metric to improve future patient stratification.

Equivalence of cisplatin and carboplatin-based chemoradiation for locally advanced squamous cell carcinoma of the head and neck: a matched-pair analysis.

BACKGROUND: Carboplatin can be substituted for cisplatin in concomitant chemoradiation (CRT) for locally advanced squamous cell carcinoma of the head and neck (LASCCHN) when the latter is contraindicated. This matched-pair study aimed to compare the efficacy and acute toxicity of carboplatin and cisplatin. METHODS: Patients treated with 2 cycles of concomitant carboplatin-based CRT were matched to patients treated with 2 cycles of cisplatin. Matching criteria included age, tumour site, stage, smoking status and use of induction chemotherapy. Radiation was delivered using conformal techniques. Data on weekly acute toxicity throughout CRT was compared using the chi-squared test for proportions. Kaplan Meier statistics described time to local relapse, distant relapse and overall survival, the log-rank test was used to compare 3-year survival outcomes. RESULTS: Sixty-five patients who received carboplatin were matched to 65 who received cisplatin. Significant differences in toxicity included increased emesis with cisplatin and more anaemia and thrombocytopenia with carboplatin. There was no significant difference in 3-year locoregional control (87% vs. 79%, p=0.54), freedom from distant metastases (88% vs. 85%, p=0.79) and overall survival (59% vs. 68%, p=0.24) between the carboplatin and cisplatin cohorts, respectively. CONCLUSIONS: When cisplatin is contraindicated, carboplatin-based CRT yields equivalent treatment outcomes in patients with LASCCHN.

Kinetic analysis of cyclic CMP-specific and multifunctional phosphodiesterases by quantitative positive-ion fast-atom bombardment mass spectrometry.

Two enzymes, cyclic CMP-specific phosphodiesterase and multifunctional phosphodiesterase, are responsible for the hydrolysis of cytidine 3',5'-cyclic monophosphate in living cells. Quantitation of both enzymes has been carried out by positive-ion fast-atom bombardment mass spectrometric analysis of the enzyme incubates after termination of the reaction. The kinetic data obtained are in close agreement with parallel data obtained by the conventional radiometric assay. The extra facility of the mass spectrometry based assay to monitor several incubation components simultaneously has been exploited to study the concurrent hydrolysis of alternate cyclic nucleotide substrates and provides kinetic parameters of significance in interpreting substrate-enzyme interactions. This is extended by the use of collisionally-induced dissociation of the protonated molecules of the liberated products to identify the mononucleotide isomers resulting from the cyclic nucleotide hydrolysis.

Kinetic analysis and multiple component monitoring of effectors of adenylyl cyclase activity by quantitative fast-atom bombardment mass spectrometry.

The enzyme adenylyl cyclase catalyses the conversion of adenosine 5'-triphosphate (ATP) to adenosine-3',5'-cyclic monophosphate (cyclic AMP), and is an important pharmaceutical target. Quantitation of this enzyme's activity has been carried out by positive-ion fast-atom bombardment mass spectrometric analysis of the enzyme incubation mixture after the reaction has been terminated. The kinetic data obtained are in good agreement with those obtained by the conventional radiometric assay, and this mass spectrometry-based assay offers the facility to monitor the turnover of several components of the incubation simultaneously. This is utilized to study the relative efficiencies of two ATP-regenerating systems, three phosphodiesterase inhibitors and two modified substrates, and to monitor the uptake and conversion of two competing substrates, adenosine 5' triphosphate and 2'-deoxyadenosine-5-triphosphate, to cyclic AMP and to cyclic deoxyAMP, respectively.

Influence of the length and position of the collision cell on the resolving power attainable from collisionally activated processes in sector instruments.

The energy resolution in a high resolution tandem mass spectrometer was investigated in terms of the length and position of the central collision cell. Both these parameters have to be chosen carefully to eliminate collisional broadening phenomena that can severely limit the energy resolution in such instruments. A theory that describes collisional broadening, to first order, has been derived that accounts for the observed phenomena. It was found experimentally that collisional broadening can be reduced to less than 0.001 eV per kiloelectronvolt collision energy. Experimental data confirmed that only the size of the resolving slits and thermal broadening, due to the target gas, limited the ultimate energy resolution available.