Mutation of TP53, translocation analysis and immunohistochemical expression of MYC, BCL-2 and BCL-6 in patients with DLBCL treated with R-CHOP.

Diffuse large B-cell lymphoma (DLBCL) is an aggressive lymphoma with diverse outcomes. Concurrent translocation of MYC and BCL-2 and/or BCL-6, and concurrent immunohistochemical (IHC) high expression of MYC and BCL-2, have been linked to unfavorable treatment responses. TP53-mutated DLBCL has also been linked to worse outcome. Our aim was to evaluate the aforementioned issues in a cohort of 155 patients uniformly treated with R-CHOP-like therapies. We performed direct sequencing of TP53 exons 5, 6, 7 and 8 as well as fluorescence in-situ hybridization (FISH) of MYC, BCL-2 and BCL-6, and IHC of MYC, BCL-2 and BCL-6. In multivariate analysis, TP53 mutations in L3 and loop-sheet helix (LSH) associated with a risk ratio (RR) of disease-specific survival (DSS) of 8.779 (p = 0.022) and a RR of disease-free survival (DFS) of 10.498 (p = 0.011). In IHC analysis BCL-2 overexpression was associated with inferior DFS (p = 0.002) and DSS (p = 0.002). DLBCL with BCL-2 and MYC overexpression conferred inferior survival in all patients (DSS, p = 0.038 and DFS, p = 0.011) and in patients with non-GC phenotype (DSS (p = 0.013) and DFS (p = 0.010). Our results imply that in DLBCL, the location of TP53 mutations and IHC analysis of BCL-2 and MYC might have a role in the assessment of prognosis.

[Chemotherapy in conjunction with blood brain barrier disruption in the treatment of primary central nervous system lymphoma]. / Veri-aivoesteen avaaminen tehokeinona aivolymfooman solunsalpaajahoidossa.

Primary central nervous system lymphoma (PCNSL) is sensitive to both chemotherapy and radiation, but the blood-brain barrier limits the usefulness of the most effective chemotherapeutic agents. On the other hand radiation therapy carries along serious long term adverse events. In BBBD-therapy the blood-brain barrier is opened with intra-arterial mannitol infusion thus permitting both the chemotherapeutics and antibodies to enter through blood-brain barrier. So far 17 patients have started the therapy in our clinics. Ten patients have reached a complete response and 8 of these responses are ongoing with follow-up times of 6-62 months.

Cell cycle regulation score predicts relapse-free survival in non-germinal centre diffuse large B-cell lymphoma patients treated by means of immunochemotherapy.

OBJECTIVES: The cell cycle is under strict regulation by the retinoblastoma, p53 and p27 pathways, and the disruption of these pathways is an important characteristic of diffuse large B-cell lymphoma (DLBCL). In this study, we wanted to assess the function and prognostic significance of these pathways in DLBCL patients. METHODS: Tissue samples from 120 DLBCL patients treated by means of R-CHOP-type chemotherapy were stained for the cell cycle-regulating proteins p16, p21, p27 and p53, and the germinal centre (GC) phenotype was determined according to Hans' algorithm. Based on the number of impaired cell cycle-regulating pathways a predictive score was obtained, covering three different prognostic groups: a 'favourable' group with damage in 0-1 of the studied pathways, a 'poor' group with damage in all three pathways and an 'intermediate' group comprising the rest of the patients. RESULTS: The prognosis of non-GC DLBCL patients was significantly poorer vs. GC phenotype patients (P = 0.015). The prognostic score proved especially useful among non-GC phenotype patients, with 3-yrs relapse-free survival of 100% vs. 62.6% vs. 24.3% in the 'favourable-', 'intermediate-' and 'poor prognosis' groups, respectively (P = 0.003). CONCLUSION: The prognosis of non-GC DLBCL patients is progressively impaired with the accumulation of damage in different cell cycle-regulating pathways.

Specific TP53 mutations predict aggressive phenotype in head and neck squamous cell carcinoma: a retrospective archival study.

BACKGROUND: Head and neck squamous cell carcinoma (HNSCC) is the sixth most common malignancy in the world in developed countries. Despite the intense research in the area of squamous cell carcinomas of head and neck (HNSCC), long-term survival rate has not changed significantly in this malignancy during recent decades. METHODS: In this study, we focused on TP53 mutations in specific regions, including DNA-binding surface, to determine whether mutations at specific locations of TP53 could be used to help in setting up prognosis and response to therapy of head and neck squamous cell carcinoma patients. We analysed TP53 mutations in 46 HNSCC by PCR-SSCP and sequencing and characterized how different TP53 mutations affect the patient outcome. RESULTS: Tumours containing TP53 mutations in DNA-binding regions (L2, L3 and LSH motif) had a significantly poorer prognosis and response to radiotherapy than tumours outside those regions. Disease-specific 5-year survival of patients with TP53 mutations affecting DNA contacts was 43.5% while it was 77.8% (p < 0.05) in patients with TP53 mutations in other residues not involved in DNA contact. Moreover, nodal metastasis were more prevalent (although not statistically significantly) with TP53 mutations in DNA-binding surface regions. We noticed that the patients with TP53 mutations in L3/LSH motifs had a significantly poorer response (11.4% responding) to radiation than the patients with a wild type p53 (48.6%) or TP53 mutations outside the DNA-binding regions (40%) (p < 0.05). CONCLUSIONS: These data indicate that a TP53 mutation in L2, L3 or LSH is worth pursuing as a marker for predicting prognosis and response to radiation among HNSCC patients.

(Pro)renin receptors and angiotensin converting enzyme 2/angiotensin-(1-7)/Mas receptor axis in human aortic valve stenosis.

BACKGROUND: There is increasing evidence that renin-angiotensin system (RAS) may play a major role in the actively regulated fibrocalcific process in aortic valve stenosis (AS), but the gene expression or function of (pro)renin receptor ((P)RR), prorenin and renin or angiotensin converting enzyme 2(ACE2)/angiotensin-(1-7)/Mas receptor axis in calcific aortic valve disease is not known. METHODS AND RESULTS: We characterized expression of (P)RR, ACE2 and Mas receptor as well as renin, prorenin and angiotensin II type 2 (AT(2)) receptors in human aortic valves, and compared normal control valves (n = 11) with valves obtained from patients with aortic regurgitation (AR, n = 14), AR with fibrosis (n = 20) and AS (n = 61). By immunohistochemistry (P)RR positive staining was seen in the valvular endothelial cells of control and in the neovessels of stenotic valves. By RT-PCR, renin mRNA levels were 72% (P = 0.001) and prorenin mRNA levels 64% lower (P = 0.002) in stenotic aortic valves compared to control valves. ACE2, Mas receptor and AT(2)-receptor mRNA levels were 69% (P < 0.001), 58% (P = 0.008) and 75% (P = 0.001) lower, respectively, in stenotic valves. ACE2 positive staining, existing to lesser extent in stenotic aortic valves, was localized mainly to stromal area in spongiosa layer in control valves. CONCLUSIONS: (P)RR, prorenin and renin are expressed in human aortic valves. We also report for the first time expression of ACE2/angiotensin-(1-7)/-Mas receptor axis in human aortic valve cusps. The downregulation of ACE2/angiotensin-(1-7)/-Mas receptor axis as well as AT(2)-receptors may promote fibrosis, proliferation and inflammation in patients with AS.

p53 in head and neck cancer: functional consequences and environmental implications of TP53 mutations.

BACKGROUND: Although TP53 mutations in human tumours generally have been extensively studied, the significance of p53 in the aetiology of head and neck cancers is still incompletely characterized. In recent years, considerable interest has been focused on mutant forms of p53, the abnormal protein product of TP53 alleles with missense mutation that often accumulate in cancer cells. METHODS: We compared the nature of TP53 mutations in primary 46 head and neck squamous cell carcinomas (HNSCC) analyzed by PCR-SSCP and sequencing, immunohistochemistry, and using structural information available at IARC p53 database. RESULTS: Sequencing confirmed 36 TP53 mutations in 23 tumours of the 39 mutations in 26 tumours found by PCR-SSCP. Only half (17) putatively affect the function of p53 protein. Of these 8 were in the L2 domain, three affected the LSH motif and three the L3 domain. Three were in other domains. Codon 259 (GAC > GAA) which is a very rare mutation was found in 4 samples in our study. There were indications of p53 aberrations being associated with the combined effect of smoking, alcohol and work history. Patients with a negative family history of cancer had more often TP53 mutations than patients with a positive family history (71% vs. 46%). CONCLUSIONS: Our study contributes to the knowledge of cumulative chemical exposure and p53 aberrations in head and neck cancer, an area where literature is scarce.