Prognostic significance of hypoxia inducible factor-1α and vascular endothelial growth factor expression in patients with diffuse large B-cell lymphoma treated with rituximab

Metabolic Reprogramming and Potential Therapeutic Targets in Lymphoma

Lymphoma is a heterogeneous group of diseases that often require their metabolism program to fulfill the demand of cell proliferation. Features of metabolism in lymphoma cells include high glucose uptake, deregulated expression of enzymes related to glycolysis, dual capacity for glycolytic and oxidative metabolism, elevated glutamine metabolism, and fatty acid synthesis. These aberrant metabolic changes lead to tumorigenesis, disease progression, and resistance to lymphoma chemotherapy. This metabolic reprogramming, including glucose, nucleic acid, fatty acid, and amino acid metabolism, is a dynamic process caused not only by genetic and epigenetic changes, but also by changes in the microenvironment affected by viral infections. Notably, some critical metabolic enzymes and metabolites may play vital roles in lymphomagenesis and progression. Recent studies have uncovered that metabolic pathways might have clinical impacts on the diagnosis, characterization, and treatment of lymphoma subtypes. However, determining the clinical relevance of biomarkers and therapeutic targets related to lymphoma metabolism is still challenging. In this review, we systematically summarize current studies on metabolism reprogramming in lymphoma, and we mainly focus on disorders of glucose, amino acids, and lipid metabolisms, as well as dysregulation of molecules in metabolic pathways, oncometabolites, and potential metabolic biomarkers. We then discuss strategies directly or indirectly for those potential therapeutic targets. Finally, we prospect the future directions of lymphoma treatment on metabolic reprogramming.

Hypoxia-targeting therapy for intestinal T-cell lymphoma in dogs: Preclinical study using 3D in vitro models

The transcription factor hypoxia-inducible factor 1α (HIF-1α) is activated in response to oxygen deficiency, and is expressed in several cancers under intratumoral hypoxic stress that arises during pathogenic processes. Hypoxic stimulation enhanced the growth potential of canine lymphoma cells by activating the HIF-1α signalling pathway in a previously reported study. The aim of this study was to establish a molecular design strategy for a novel hypoxia-targeting therapy for intestinal T-cell lymphoma (ITL) in dogs. We assessed the relationship between immunohistochemistry-based HIF-1α expression and clinical information, including signalment, tumour area, clinical signs, systemic diseases, treatment protocol, follow-up information, chemotherapy response and overall survivals (OS), using 48 tissue samples from dogs with ITL. We investigated the effects of hypoxic stimulation on the biological behaviour of cell lines from three different types of canine ITL. We assessed the effects of evofosfamide (Evo; hypoxia-activated prodrug) on cell lines cultured under hypoxic conditions. Our data showed that treatment response and overall survival might be significantly decreased in dogs with higher HIF-1α expression than in those with lower HIF-1α expression. Hypoxic culture (1% O₂ , 72 h) enhanced the invasiveness of cell lines and decreased their sensitivity to CCNU, resulting in hypoxia-dependent aggressive behaviour. Sensitivity to Evo significantly increased in cell lines cultured under hypoxia compared with those cultured under normoxia, which exhibited hypoxia-dependent apoptosis. Additionally, Evo downregulated HIF-1α expression in cell lines cultured under hypoxia, suggesting that Evo might inhibit cell growth by inactivating HIF-1α-dependent cell signalling. Our results revealed the preclinical antitumor activity of Evo and provide a rationale for treatment strategies for dogs with ITL.

Sustain, Adapt, and Overcome-Hypoxia Associated Changes in the Progression of Lymphatic Neoplasia

Irregular perfusion and related tissue hypoxia is a common feature of solid tumors the role of which in the survival and progression cancer has been gradually recognized. Adaptation and selection mechanisms in hypoxic areas in solid tumors are regulated by Hypoxia Inducible transcriptional factor 1 (HIF1) and other hypoxia mediators and are associated with aggressive clinical behavior in a large spectrum of malignancies. Aggressive forms of lymphatic neoplasias present with solid tumor-like features, also including rapid cell growth, necrosis and angiogenesis, the clinical potential of which is still underestimated. While the role of regional hypoxia in normal B-cell maturation and malignant transformation is becoming evident, the impact of tissue hypoxia on their behavior is not well-understood. Compared to some of the common solid cancer types data for some of the key regulators, such as HIF1 and HIF2, and for their downstream effectors are available in a limited fashion. In the current review we aim to overview the physiological aspects of major hypoxia pathways during B-cell maturation and adaptation-related changes reported in lymphatic neoplasia covering important targets, such as carbonic anhydrases IX and XII (CAIX, CAXII), glucose transporter 1 (GLUT-1) and vascular endothelial growth factor (VEGF). In conclusion, experimental and clinical results direct to important but currently unexploited role of hypoxia-driven resistance mechanisms especially in aggressive forms of B-cell neoplasia.

The hypoxia signalling pathway in haematological malignancies

Haematological malignancies are tumours that affect the haematopoietic and the lymphatic systems. Despite the huge efforts to eradicate these tumours, the percentage of patients suffering resistance to therapies and relapse still remains significant. The tumour environment favours drug resistance of cancer cells, and particularly of cancer stem/initiating cells. Hypoxia promotes aggressiveness, metastatic spread and relapse in most of the solid tumours. Furthermore, hypoxia is associated with worse prognosis and resistance to conventional treatments through activation of the hypoxia-inducible factors. Haematological malignancies are not considered solid tumours, and therefore, the role of hypoxia in these diseases was initially presumed to be inconsequential. However, hypoxia is a hallmark of the haematopoietic niche. Here, we will review the current understanding of the role of both hypoxia and hypoxia-inducible factors in different haematological tumours.

Anti-angiogenic effects of biotechnological therapies in rheumatic diseases

Introduction

Angiogenesis plays a key role in the pathogenesis of numerous rheumatic diseases, such as rheumatoid arthritis, psoriatic arthritis, and vasculitides. Therefore, the inhibition of pathological angiogenesis may be considered a useful therapeutical approach in these rheumatic diseases.

Methods

This review article is based on a literature research about the role of biotechnological therapies in angiogenesis inhibition.

Results and conclusions

Several evidences have demonstrated a role for biotechnological therapies in angiogenesis inhibition. Nevertheless, further research and clinical trials are needed to better quantify the real impact of biotechnological therapies on pathological angiogenesis.

Hypoxia-activated prodrug TH-302 decreased survival rate of canine lymphoma cells under hypoxic condition

We tested the hypotheses that hypoxic stimulation enhances growth potentials of canine lymphoma cells by activating hypoxia-inducible factor 1α (HIF-1α), and that the hypoxia-activated prodrug (TH-302) inhibits growth potentials in the cells. We investigated how hypoxic culture affects the growth rate, chemoresistance, and invasiveness of canine lymphoma cells and doxorubicin (DOX)-resistant lymphoma cells, and influences of TH-302 on survival rate of the cells under hypoxic conditions. Our results demonstrated that hypoxic culture upregulated the expression of HIF-1α and its target genes, including ATP-binding cassette transporter B1 (ABCB1), ATP-binding cassette transporter G2 (ABCG2), platelet-derived growth factor (PDGF), vascular endothelial growth factor (VEGF), and survivin, and enhanced the growth rate, DOX resistance, and invasiveness of the cells. Additionally, TH-302 decreased the survival rate of the cells under hypoxic condition. Our studies suggest that hypoxic stimulation may advance the tumorigenicity of canine lymphoma cells, favoring malignant transformation. Therefore, the data presented may contribute to the development of TH-302-based hypoxia-targeting therapies for canine lymphoma.

Assessment of carbonic anhydrase IX expression and extracellular pH in B-cell lymphoma cell line models

The expression of carbonic anhydrase IX (CA IX) and its relationship to acidosis in lymphomas has not been widely studied. We investigated the protein expression of CA IX in a human B-cell lymphoma tissue microarray, and in Raji, Ramos and Granta 519 lymphoma cell lines and tumor models, while also investigating the relationship with hypoxia. An imaging method, acidoCEST magnetic resonance imaging (MRI), was used to estimate lymphoma xenograft extracellular pH (pHe). Our results showed that clinical lymphoma tissues and cell line models in vitro and in vivo had moderate CA IX expression. Although in vitro studies showed that CA IX expression was induced by hypoxia, in vivo studies did not show this correlation. Untreated lymphoma xenograft tumor pHe had acidic fractions, and an acidity score was qualitatively correlated with CA IX expression. Therefore, CA IX is expressed in B-cell lymphomas and is qualitatively correlated with extracellular acidosis in xenograft tumor models.

Relationships between VEGF protein expression and pathological characteristics of diffuse large B cell lymphoma: a meta-analysis

We carried out the current meta-analysis of relevant cohort studies in an attempt to investigate the relationships between vascular endothelial growth factor (VEGF) expression and pathological characteristics of diffuse large B cell lymphoma (DLBCL). The following electronic databases were searched for relevant articles without any language restrictions: Web of Science (1945 ~ 2013), the Cochrane Library Database (Issue 12, 2013), PubMed (1966 ~ 2013), EMBASE (1980 ~ 2013), CINAHL (1982 ~ 2013), and the Chinese Biomedical Database (CBM) (1982 ~ 2013). Meta-analyses were conducted with the use of STATA software (version 12.0, Stata Corporation, College Station, TX, USA). Odds ratios (ORs) and its 95 % confidence interval (95 % CI) were calculated. Nine clinical cohort studies with a total of 789 DLBCL patients met our inclusion criteria. The meta-analysis results showed that patients with positive VEGF expression had higher international prognostic index (IPI) scores than VEGF-negative patients (OR = 5.12, 95 % CI = 2.70 ~ 9.71, P < 0.001). There was a significantly positive association between positive VEGF expression and evaluated lactate dehydrogenase (LDH) levels (OR = 2.50, 95 % CI = 1.36 ~ 4.60, P = 0.003). We also found that patients with positive B symptoms had increased level of VEGF expression (OR = 2.02, 95 % CI = 1.08 ~ 3.77, P = 0.027). The findings of our meta-analysis provide reliable evidence that VEGF expression may be strongly correlated with pathological characteristics of DLBCL.