High intensity of cytoplasmic peroxiredoxin VI expression is associated with adverse outcome in diffuse large B-cell lymphoma independently of International Prognostic Index

Vagal Nerve Activity Predicts Prognosis in Diffused Large B-Cell Lymphoma and Multiple Myeloma

This study examined the prognostic role of vagal nerve activity in patients with relapsed/refractory diffused large B-cell lymphoma (R/R-DLBCL) treated with chimeric antigen receptor cell therapy (CAR-T) and in patients with multiple myeloma (MM) undergoing an autologous hematopoietic cell transplantation (AutoHCT). Participants included 29 patients with R/R-DLBCL and 37 patients with MM. Inclusion criteria were: (1) age over 18; (2) diagnosed with DLBCL or MM; (3) being treated with CAR-T or AutoHCT; and (4) having an ECG prior to cell transfusion. The predictor was vagal nerve activity indexed by heart rate variability (HRV) and obtained retroactively from 10 s ECGs. The main endpoint for R/R-DLBCL was overall survival (OS), and for MM the endpoint was progression-free survival (PFS). Data of 122 patients were obtained, 66 of whom were included in the study. In DLBCL, HRV significantly predicted OS independently of confounders (e.g., performance status, disease status at cell therapy), hazard ratio (HR), and 95% confidence interval (HR = 0.20; 95%CI: 0.06-0.69). The prognostic role of disease severity was moderated by HRV: among severely disease patients, 100% died with low HRV, while only 37.5% died with high HRV. In MM, HRV significantly predicted PFS (HR = 0.19; 95%CI: 0.04-0.90) independently of confounders. Vagal nerve activity independently predicts prognosis in patients with R/R-DLBCL and with MM undergoing cell therapy. High vagal activity overrides the prognostic role of disease severity. Testing the effects of vagal nerve activation on prognosis in blood cancers is recommended.

Nuclear factor erythroid 2-related factors 1 and 2 are able to define the worst prognosis group among high-risk diffuse large B cell lymphomas treated with R-CHOEP

AIMS

Oxidative stress markers and antioxidant enzymes have previously been shown to have prognostic value and associate with adverse outcome in patients with diffuse large B cell lymphoma (DLBCL). Nuclear factor erythroid 2-related factor 1 (Nrf1) and factor 2 (Nrf2) are among the principal inducers of antioxidant enzyme production. Kelch ECH associating protein 1 (Keap1) is a negative regulator of Nrf2, and BTB (BR-C, ttk and bab) domain and CNC homolog 1 (Bach1) represses the function of both factors. Their significance in DLBCL prognosis is unknown.

METHODS

Diagnostic biopsy samples of 76 patients with high-risk DLBCL were retrospectively stained with immunohistochemistry for Nrf1, Nrf2, Keap1 and Bach1, and correlated with clinical data and outcome.

RESULTS

Nuclear Nrf2 and nuclear Bach1 expression were associated with adverse clinical features (anaemia, advanced stage, high IPI, high risk of neutropaenic infections), whereas cytoplasmic Nrf1 and Nrf2 were associated with favourable clinical presentation (normal haemoglobin level, no B symptoms, limited stage). None of the evaluated factors could predict survival alone. However, when two of the following parameters were combined: high nuclear score of Nrf2, low nuclear score of Nrf1, high cytoplasmic score of Nrf1 and low cytoplasmic score of Keap1 were associated with significantly worse overall survival.

CONCLUSIONS

Nrf1 and Nrf2 are relevant in disease presentation and overall survival in high-risk DLBCL. Low nuclear expression of Nrf1, high cytoplasmic expression of Nrf1, high nuclear expression of Nrf2 and low cytoplasmic expression of Keap1 are associated with adverse outcome in this patient group.

The prognostic values of the peroxiredoxins family in ovarian cancer

Purpose: Peroxiredoxins (PRDXs) are a family of antioxidant enzymes with six identified mammalian isoforms (PRDX1–6). PRDX expression is up-regulated in various types of solid tumors; however, individual PRDX expression, and its impact on prognostic value in ovarian cancer patients, remains unclear.

Methods: PRDXs family protein expression profiles in normal ovarian tissues and ovarian cancer tissues were examined using the Human Protein Atlas database. Then, the prognostic roles of PRDX family members in several sets of clinical data (histology, pathological grades, clinical stages, and applied chemotherapy) in ovarian cancer patients were investigated using the Kaplan–Meier plotter.

Results: PRDXs family protein expression in ovarian cancer tissues was elevated compared with normal ovarian tissues. Meanwhile, elevated expression of PRDX3, PRDX5, and PRDX6 mRNAs showed poorer overall survival (OS); PRDX5 and PRDX6 also predicted poor progression-free survival (PFS) for ovarian cancer patients. Furthermore, PRDX3 played significant prognostic roles, particularly in poor differentiation and late-stage serous ovarian cancer patients. Additionally, PRDX5 predicted a lower PFS in all ovarian cancer patients treated with Platin, Taxol, and Taxol+Platin chemotherapy. PRDX3 and PRDX6 also showed poor PFS in patients treated with Platin chemotherapy. Furthermore, PRDX3 and PRDX5 indicated lower OS in patients treated with these three chemotherapeutic agents. PRDX6 predicted a poorer OS in patients treated with Taxol and Taxol+Platin chemotherapy.

Conclusion: These results suggest that there are distinct prognostic values of PRDX family members in patients with ovarian cancer, and that the expression of PRDX3, PRDX5, and PRDX6 mRNAs are a useful prognostic indicator in the effect of chemotherapy in ovarian cancer patients.

The phospholipase A2 activity of peroxiredoxin 6

Peroxiredoxin 6 (Prdx6) is a Ca²⁺-independent intracellular phospholipase A₂ (called aiPLA₂) that is localized to cytosol, lysosomes, and lysosomal-related organelles. Activity is minimal at cytosolic pH but is increased significantly with enzyme phosphorylation, at acidic pH, and in the presence of oxidized phospholipid substrate; maximal activity with phosphorylated aiPLA₂ is ∼2 µmol/min/mg protein. Prdx6 is a "moonlighting" protein that also expresses glutathione peroxidase and lysophosphatidylcholine acyl transferase activities. The catalytic site for aiPLA₂ activity is an S32-H26-D140 triad; S32-H26 is also the phospholipid binding site. Activity is inhibited by a serine "protease" inhibitor (diethyl p-nitrophenyl phosphate), an analog of the PLA₂ transition state [1-hexadecyl-3-(trifluoroethyl)-sn-glycero-2-phosphomethanol (MJ33)], and by two naturally occurring proteins (surfactant protein A and p67^phox), but not by bromoenol lactone. aiPLA₂ activity has important physiological roles in the turnover (synthesis and degradation) of lung surfactant phospholipids, in the repair of peroxidized cell membranes, and in the activation of NADPH oxidase type 2 (NOX2). The enzyme has been implicated in acute lung injury, carcinogenesis, neurodegenerative diseases, diabetes, male infertility, and sundry other conditions, although its specific roles have not been well defined. Protein mutations and animal models are now available to further investigate the roles of Prdx6-aiPLA₂ activity in normal and pathological physiology.

Redox Regulating Enzymes and Connected MicroRNA Regulators Have Prognostic Value in Classical Hodgkin Lymphomas

There are no previous studies assessing the microRNAs that regulate antioxidant enzymes in Hodgkin lymphomas (HLs). We determined the mRNA levels of redox regulating enzymes peroxiredoxins (PRDXs) I–III, manganese superoxide dismutase (MnSOD), nuclear factor erythroid-derived 2-like 2 (Nrf2), and Kelch-like ECH-associated protein 1 (Keap1) from a carefully collected set of 41 classical HL patients before receiving any treatments. The levels of redoxmiRs, miRNAs known to regulate the above-mentioned enzymes, were also assessed, along with CD3, CD20, and CD30 protein expression. RNAs were isolated from freshly frozen lymph node samples and the expression levels were analyzed by qPCR. mir23b correlated inversely with CD3 and CD20 expressions (p = 0.00076; r = −0.523 and p = 0.0012; r = −0.507) and miR144 with CD3, CD20, and CD30 (p = 0.030; r = −0.352, p = 0.041; r = −0.333 and p = 0.0032; r = −0.47, resp.). High MnSOD mRNA levels associated with poor HL-specific outcome in the patients with advanced disease (p = 0.045) and high miR-122 levels associated with worse HL-specific survival in the whole patient population (p = 0.015). When standardized according to the CD30 expression, high miR212 and miR510 predicted worse relapse-free survival (p = 0.049 and p = 0.0058, resp.). In conclusion, several redoxmiRs and redox regulating enzyme mRNA levels associate with aggressive disease outcome and may also produce prognostic information in classical HL.

The role of peroxiredoxins in cancer

Peroxiredoxins (PRDXs) are a ubiquitously expressed family of small (22–27 kDa) non-seleno peroxidases that catalyze the peroxide reduction of H₂O₂, organic hydroperoxides and peroxynitrite. They are highly involved in the control of various physiological functions, including cell growth, differentiation, apoptosis, embryonic development, lipid metabolism, the immune response, as well as cellular homeostasis. Although the protective role of PRDXs in cardiovascular and neurological diseases is well established, their role in cancer remains controversial. Increasing evidence suggests the involvement of PRDXs in carcinogenesis and in the development of drug resistance. Numerous types of cancer cells, in fact, are characterized by an increase in reactive oxygen species (ROS) production, and often exhibit an altered redox environment compared with normal cells. The present review focuses on the complex association between oxidant balance and cancer, and it provides a brief account of the involvement of PRDXs in tumorigenesis and in the development of chemoresistance.

Total peroxiredoxin expression is associated with survival in patients with follicular lymphoma

Redox state-regulating enzymes may have roles in chemoresistance and also in lymphomagenesis, but there have been only a limited number of studies on this topic in lymphomas. Our aim was to assess expression of the redox state-regulating enzymes peroxiredoxins (Prxs) I-VI and thioredoxin (Trx) and the oxidative stress marker nitrotyrosine in follicular lymphomas (FLs). We immunohistochemically assessed Prxs I-VI, Trx and nitrotyrosine in a cohort of 76 histologically confirmed, untreated FLs. We also studied the localisation of Prxs I, II, III, V and VI by means of immunoelectron microscopy (IEM). Immunohistochemistry results were correlated with disease-specific survival (DSS), progression-free survival (PFS), overall survival (OS) and clinical prognostic factors. When all Prx expression intensities were grouped as a single variable, we discovered that high total Prx intensity correlated with favourable DSS (p = 0.024) and OS (p = 0.035) but not with PFS. No deaths due to lymphoma were recorded amongst patients with high total Prx expression during the median follow-up period of 7.6 years. IEM results were in line with earlier ones demonstrating wide subcellular localisation of Prx isoenzymes. In conclusion, our results demonstrate an association between high total Prx expression and prolonged survival and suggest that Prxs may have a protective role in FL that cannot be compensated by other antioxidant mechanisms.