C-reactive protein is a prognostic biomarker in pancreatic ductal adenocarcinoma patients

AIM

The 5-year survival rate of pancreatic ductal adenocarcinoma (PDAC) is approximately 11% and has only improved marginally over the last three decades. For operable PDAC, resection and adjuvant FOLFIRINOX chemotherapy is standard of care. There is growing interest in perioperative regimens to improve outcomes. The non-randomized Phase II study "Gemcitabine and Abraxane for resectable Pancreatic cancer" (GAP) demonstrated the feasibility of perioperative gemcitabine/abraxane. Long-term survival in PDAC requires an effective immune response; hence, we undertook this translational study of the GAP trial cohort to identify immune-oncology biomarkers for clinical use.

METHODS

We combined Nanostring nCounter technology with immunohistochemistry to investigate the correlation between gene expression and overall patient survival. Findings were investigated in samples from the International Cancer Genome Consortium (ICGC, n = 88) and the Australian Pancreatic Genome Initiative (APGI, n = 227).

RESULTS

We confirmed that human equilibrative nucleoside transporter 1 (hENT1) expression was not a prognostic marker in PDAC but patients with high levels of hENT1 were more likely to live longer than 24 months post-surgery. Additionally, CD274 (PD-L1) and two novel biomarkers of survival, cathepsin W (CTSW) and C-reactive protein (CRP), were identified in the GAP cohort (n = 19). CRP expression was confirmed in data from the ICGC. Although PD-L1 and CTSW proteins were not significant across all three cohorts, results show that low CRP mRNA and protein expression are associated with longer overall survival in all three patient groups.

CONCLUSION

PDAC patients with long survival have higher hENT1 expression levels. Furthermore, CRP expression is a biomarker of poor prognosis following perioperative chemotherapy and resection in PDAC patients and thus may be useful for identifying patients who could benefit from more aggressive adjuvant strategies.

Radiomics Biomarkers Correlate with CD8 Expression and Predict Immune Signatures in Melanoma Patients

Treatment for metastatic melanoma includes targeted and/or immunotherapy. Although many patients respond, only a subset has complete response. As late-stage patients often have multiple tumors in difficult access sites, non-invasive techniques are necessary for the development of predictive/prognostic biomarkers. PET/CT scans from 52 patients with stage III/IV melanoma were assessed and CT image parameters were evaluated as prognostic biomarkers. Analysis indicated patients with high standard deviation or high mean of positive pixels (MPP) had worse progression-free survival (P = 0.00047 and P = 0.0014, respectively) and worse overall survival (P = 0.0223 and P = 0.0465, respectively). Whole-exome sequencing showed high MPP was associated with BRAF mutation status (P = 0.0389). RNA-sequencing indicated patients with immune "cold" signatures had worse survival, which was associated with CT biomarker, MPP4 (P = 0.0284). Multiplex immunofluorescence confirmed a correlation between CD8 expression and image biomarkers (P = 0.0028). IMPLICATIONS: CT parameters have the potential to be cost-effective biomarkers of survival in melanoma, and reflect the tumor immune-microenvironment. VISUAL OVERVIEW: http://mcr.aacrjournals.org/content/molcanres/19/6/950/F1.large.jpg.

Cholesterol and its derivatives, are the principal steroids isolated from the leech species Hirudo medicinalis

Steroids were isolated from the blood-sucking leech species Hirudo medicinalis and their structure was studied with one- and two-dimensional NMR spectroscopy (DQF-COSY and HMQC), GC-MS and ESI-MS spectrometry. Fractionating leech lipid using silicic acid chromatography led to the isolation of cholesterol in an early chloroform-eluted peak. Only minor traces of cholest-4-en-3-one, 4 beta-methylcholesterol, and sitosterol were present. The subsequent acetone-eluted fraction contained steroidtriols that were further purified by preparative TLC; these included cholest-7-ene-3,5,6 triol, cholest-4,7-diene-3,6,15 triol and to a lesser amount, cholestane-3,5,6 triol. A developmental study on cholesterol content in the leech showed that it is also the principal steroid in embryonic and freshly hatched leeches prior to feeding. The abundance of cholesterol, comprising approximately 5% of the total leech lipid, suggests that H. medicinalis, a blood sucking leech, has adapted itself fully to its mammalian host in terms of its steroid content. It remains to be seen whether lipids are directly transferred from the host to the parasite or whether leeches have evolved mechanisms to synthesize their own steroids.

Structural analysis of leech galactocerebrosides using 1D and 2D NMR spectroscopy, gas chromatography-mass spectrometry, and FAB mass spectrometry

Cerebrosides were isolated from the leech species, Hirudo medicinalis, and purified to homogeneity by silicic acid chromatography, followed by preparative thin-layer chromatography. Their structure was determined by spectroscopic and chemical methods. 1D and 2D 1H NMR spectroscopy, DQF-COSY and HMQC indicated that the head group consists of a single galactose residue in the beta configuration. The galacto configuration was determined by the characteristic chemical shift, the spin-spin splitting and the multiplicity of the characteristic resonance of its equatorial H-4 proton, as well as by the splittings of the other ring protons. GC, GC-MS and fast-atom-bombardment mass spectrometry studies indicated that C24:0 and C22:0 are the major saturated fatty acid species. Unsaturated fatty acids present were C25:2, C27:2, C27:3, C28:3, C29:3, C30:3, C33:3. GC-MS indicated the presence of hydroxylated C27:2 and one other unidentified hydroxylated fatty acid. The cerebroside contained an unusual polyunsaturated sphingosine analogue, namely 2-amino-1,3-dihydroxydocsatriene.

Mutation or increased copy number of nodE has no effect on the spectrum of chitolipooligosaccharide nod factors made by Rhizobium leguminosarum bv. trifolii

The bacterial gene nodE is the key determinant of host specificity in the Rhizobium leguminosarum-legume symbiosis and has been proposed to determined unique polyunsaturated fatty acyl moieties in chitolipooligosaccharides (CLOS) made by the bacterial symbiont. We evaluated nodE function by examining CLOS structures made by wild-type R. leguminosarum bv. trifolii ANU843, an isogenic nodE::Tn5 mutant, and a recombinant strain containing multiple copies of the pSym nod region of ANU843. 1H-NMR, electrospray ionization mass spectrometry, fast atom bombardment mass spectrometry, flame ionization detection-gas chromatography, gas chromatography/mass spectrometry, and high performance liquid chromatography/UV photodiode array analyses revealed that these bacterial strains made the same spectrum of CLOS species. We also found that ions in the mass spectra which were originally assigned to nodE-dependent CLOS species containing unique polyunsaturated fatty acids (Spaink, H. P., Bloemberg, G. V., van Brussel, A. A. N., Lugtenberg, B. J. J., van der Drift, K. M. G. M., Haverkamp, J., and Thomas-Oates, J. E. (1995) Mol. Plant-Microbe Interact. 8, 155-164) were actually due to sodium adducts of the major nodE-independent CLOS species. No evidence for nodE-dependent CLOSs was found for these strains. These results indicate a need to revise the current model to explain how nodE determines host range in the R. leguminosarum-legume symbiosis.

Determination of Ro 19-6327 (Lazabemide) in human plasma and urine by gas chromatography-negative chemical ionization mass spectrometry

A sensitive and specific analytical method was developed for determination of Ro 19-6327 (Lazabemide) in human plasma and urine samples to provide pharmacokinetic data from clinical trials. The new method employs a simple liquid-liquid extraction to isolate the drug from biological samples. The extract is reacted to form the trifluoroacetyl derivative of Ro 19-6327 and then analyzed by gas chromatography-negative chemical ionization mass spectrometry (GC-NCIMS). The lower limit of quantitation of the assay is 0.05 ng/ml for plasma and 5.0 ng/ml for urine, based on 1-ml aliquots. No interferences from anticoagulants, collection devices, or endogenous constituents of plasma and urine were observed. Recovery (64.3%), inter-assay precision (< 8% R.S.D.), and accuracy (> 85%) of the method were considered acceptable. The assay proved reliable enough to be automated for unattended sample analysis of approximately 50 samples daily. In an additional series of tests, Ro 19-6327 was shown to be stable under conditions that might be encountered during the analysis of samples from clinical trials.