The formation of complexes with albumin increases the stability of the protoporphyrin IX spectra.

Photodynamic therapy is a high-target, low-invasive treatment utilized to manage a variety of malignant diseases and precancerous lesions. Protoporphyrin IX (PpIX) is one of the most important photosensitizers used in photodynamic therapy, carried to the cancer tissue by serum albumin. Its delivery by transport protein is one of the major factors in determining the efficacy of photodynamic therapy. The distribution of the albumin-PpIX complexes to the target tissue enables the accomplishment of an optimal PDT effect. This study aimed to assess in vitro the stability of spectrofluorimetric spectra of albumin-PpIX complexes. The experiment used three chemicals: PpIX, human serum albumin (HSA), and bovine serum albumin (BSA). Spectral data was recorded using a Kontron SFM-25 Instrument AG, at two excitation wavelengths λex=280 nm and 295 nm. A concentration of 1x10-5M of PpIX, in combination with 1.25x10-6M of HSA and 4x10-7M of BSA, have been recorded repetitively for ten days and compared to the initial spectrum. The maximum of PpIX fluorescence changed significantly on the first day following sample preparation. The maximum of PpIX - serum albumin complex was stable 10 and 4 days for HSA and 5 and 2 days for BSA for λex=280 nm and 295 nm, respectively. The formation of a complex between PpIX and serum albumin was seen to extend the stability of the spectrofluorimetric spectrum. However, a less significant effect was observed in the case of BSA, which could most plausibly be attributed to the variations in primary structure between HSA and BSA, leading to discernible variations in spectroscopic measurements.

Influence of Cytochrome P450, ABC and SLC Gene Polymorphisms on Imatinib Therapy Outcome of Patients with Gastrointestinal Stromal Tumours (GIST).

The efficacy of imatinib-based therapy depends on the proteins involved in its metabolism and transportation. Therefore, the aim of our study was to investigate the possible correlation of selected P450, ABC and SLC polymorphic variants and the outcome of imatinib therapy. A total of 101 patients with advanced, KIT/PDGFRA(+) GIST treated with imatinib were enrolled to the study. DNA was extracted from peripheral blood samples and genotypes were determined by PCR-RFLP and direct sequencing. Deviation from the Hardy-Weinberg equilibrium was only observed for rs2740574. None of the studied SNPs was associated with GIST time to progression. No significant correlation between any specific variant and time to progression was found in the group with KIT exon 11 mutation. However, individuals of at least three potentially unfavourable genotypes presented significantly shorter time to progression in comparison to patients with two or less unfavourable genotypes.

Prognostic value of KIT/PDGFRA mutations in gastrointestinal stromal tumours (GIST): Polish Clinical GIST Registry experience.

BACKGROUND: Majority of gastrointestinal stromal tumours (GISTs) are characterised by KIT-immunopositivity and the presence of KIT/platelet-derived growth factor receptor alpha (PDGFRA) activating mutations. PATIENTS AND METHODS: Spectrum and frequency of KIT and PDGFRA mutations were investigated in 427 GISTs. Univariate and multivariate analysis of relapse-free survival (RFS) was conducted in relation to tumours' clinicopathologic features and genotype. RESULTS: Mutations were found in 351 (82.2%) cases, including 296 (69.3%) KIT and 55 (12.9%) PDGFRA isoforms. Univariate analysis revealed higher 5-year RFS rate in women (37.9%; P = 0.028) and in patients with gastric tumours (46.3%; P < 0.001). In addition a better 5-year RFS correlated with smaller tumour size ≤ 5 cm (62.7%; P < 0.001), tumours with mitotic index ≤ 5/50 high-power fields (60%; P < 0.001), and characterised by (very) low/moderate risk (70.2%; P = 0.006). Patients with GISTs bearing deletions encompassing KIT codons 557/558 had worse 5-year RFS rate (23.8%) than those with any other KIT exon 11 mutations (41.8%; P < 0.001) or deletions not involving codons 557/558 (33.3%; P = 0.007). Better 5-year RFS characterised patients with KIT exon 11 point mutations (50.7%) or duplications (40%). By multivariate analysis, tumours with PDGFRA mutations and KIT exon 11 point mutations/other than 557/558 deletions had lower risk of progression than with KIT exon 11 557/558 deletions (both Ps = 0.001). CONCLUSIONS: KIT/PDGFRA mutational status has prognostic significance for patients' outcome and may help in management of patients with GISTs.

Validation of the Joensuu risk criteria for primary resectable gastrointestinal stromal tumour - the impact of tumour rupture on patient outcomes.

BACKGROUND: Approval of imatinib for adjuvant treatment of gastrointestinal stromal tumours (GIST) raised discussion about accuracy of prognostic factors in GIST and the clinical significance of the available risk stratification criteria. METHODS: We studied the influence of a new modification of the NIH Consensus Criteria (the Joensuu risk criteria), NCCN-AFIP criteria, and several clinicopathological factors, including tumour rupture, on relapse-free survival (RFS) in a prospectively collected tumour registry series consisting of 640 consecutive patients with primary, resectable, CD117-immunopositive GIST. The median follow-up time after tumour resection was 39 months. None of the patients received adjuvant imatinib. RESULTS: The median RFS time after surgery was 50 months. In univariable analyses, high Joensuu risk group, tumour mitotic count >5/50 HPF, size >5 cm, non-gastric location, tumour rupture (7% of cases; P = 0.0014) and male gender had adverse influence on RFS. In a multivariable analysis mitotic count >5/50HPF, tumour size >5 cm and non-gastric location were independent adverse prognostic factors. Forty, 151, 86 and 348 patients were assigned according to the Joensuu criteria to very low, low, intermediate and high risk groups and had 5-year RFS of 94%, 94%, 86% and 29%, respectively. CONCLUSION: The Joensuu criteria, which include 4 prognostic factors (tumour size, site, mitotic count and rupture) and 3 categories for the mitotic count, were found to be a reliable tool for assessing prognosis of operable GIST. The Joensuu criteria identified particularly well high risk patients, who are likely the proper candidates for adjuvant therapy.