Lactate dehydrogenase 5 expression in Non-Hodgkin lymphoma is associated with the induced hypoxia regulated protein and poor prognosis

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.

Modulating Glycolysis to Improve Cancer Therapy

Cancer cells undergo metabolic reprogramming and switch to a 'glycolysis-dominant' metabolic profile to promote their survival and meet their requirements for energy and macromolecules. This phenomenon, also known as the 'Warburg effect,' provides a survival advantage to the cancer cells and make the tumor environment more pro-cancerous. Additionally, the increased glycolytic dependence also promotes chemo/radio resistance. A similar switch to a glycolytic metabolic profile is also shown by the immune cells in the tumor microenvironment, inducing a competition between the cancer cells and the tumor-infiltrating cells over nutrients. Several recent studies have shown that targeting the enhanced glycolysis in cancer cells is a promising strategy to make them more susceptible to treatment with other conventional treatment modalities, including chemotherapy, radiotherapy, hormonal therapy, immunotherapy, and photodynamic therapy. Although several targeting strategies have been developed and several of them are in different stages of pre-clinical and clinical evaluation, there is still a lack of effective strategies to specifically target cancer cell glycolysis to improve treatment efficacy. Herein, we have reviewed our current understanding of the role of metabolic reprogramming in cancer cells and how targeting this phenomenon could be a potential strategy to improve the efficacy of conventional cancer therapy.

Lactate Production can Function to Increase Human Epithelial Cell Iron Concentration

Introduction

Under conditions of limited iron availability, plants and microbes have evolved mechanisms to acquire iron. For example, metal deficiency stimulates reprogramming of carbon metabolism, increasing activity of enzymes involved in the Krebs cycle and the glycolytic pathway. Resultant carboxylates/hydroxycarboxylates then function as ligands to complex iron and facilitate solubilization and uptake, reversing the metal deficiency. Similarly, human intestinal epithelial cells may produce lactate, a hydroxycarboxylate, during absolute and functional iron deficiency to import metal to reverse limited availability.

Methods

Here we investigate (1) if lactate can increase cell metal import of epithelial cells in vitro, (2) if lactate dehydrogenase (LDH) activity in and lactate production by epithelial cells correspond to metal availability, and (3) if blood concentrations of LDH in a human cohort correlate with indices of iron homeostasis.

Results

Results show that exposures of human epithelial cells, Caco-2, to both sodium lactate and ferric ammonium citrate (FAC) increase metal import relative to FAC alone. Similarly, fumaric, isocitric, malic, and succinic acid coincubation with FAC increase iron import relative to FAC alone. Increased iron import following exposures to sodium lactate and FAC elevated both ferritin and metal associated with mitochondria. LDH did not change after exposure to deferoxamine but decreased with 24 h exposure to FAC. Lactate levels revealed decreased levels with FAC incubation. Review of the National Health and Nutrition Examination Survey demonstrated significant negative relationships between LDH concentrations and serum iron in human cohorts.

Conclusions

Therefore, we conclude that iron import in human epithelial cells can involve lactate, LDH activity can reflect the availability of this metal, and blood LDH concentrations can correlate with indices of iron homeostasis.

Diagnostic Value of Lactate Dehydrogenase and Uric Acid as Screening Tools for Malignancies in Children

OBJECTIVE

The aim of this study was to determine the diagnostic value of lactate dehydrogenase (LDH) and uric acid (UA) in children undergoing evaluation for possible malignancies.

METHODS

This was a retrospective chart review of patients aged 0 to 18 years presenting to an urban, tertiary care, pediatric hospital between July 1, 2011, and July 1, 2016. Patients were included if they had an LDH and/or UA level drawn, and they were excluded if they had a known cancer diagnosis. Sensitivity, specificity, and receiver operating characteristic curves were calculated for each biomarker.

RESULTS

Six hundred five subjects were included in this study; 579 and 384 subjects had LDH and UA levels drawn, respectively; 15.7% had a final diagnosis of malignancy (49 leukemia, 46 nonleukemia).

CONCLUSION

The specificities of both biomarkers for all types of malignancies were lower than their respective sensitivities. Comparing leukemic versus nonleukemic malignancies, the areas under the curve were 0.848 and 0.719, respectively, for LDH and 0.681 and 0.555, respectively, for UA.

Efficacy of Prednisone in Children with Acute Nonspecific Mesenteric Lymphadenitis: A Pilot Study

BACKGROUND

Acute nonspecific mesenteric lymphadenitis (ANML) is a common cause of acute abdominal pain in children with no specific treatment.

METHODS

A total of 13 patients (6 boys, 7 girls) aged 7.3 (5-13.5) years with severe acute abdominal pain were evaluated using ultrasonography and laboratory tests to establish the diagnosis of ANML. They were treated with prednisone 1 mg/kg (max 40 mg daily) for a maximum of 5 days. The intensity of abdominal pain was evaluated before and after treatment using a numeric rating scale.

RESULTS

All patients had pain scores above 6/10 before, and below 4/10 after treatment with prednisone. Intensity of abdominal pain after treatment for 1-5 days decreased significantly (p < 0.001), with no recurrence at follow-up within 3 months. All other pre-existing signs and symptoms, such as nausea, vomiting, anorexia, fever, diarrhea, and constipation were found to disappear with no adverse effects of corticosteroid therapy.

CONCLUSION

These results suggest that the treatment with prednisone in selective patients with ANML can reduce the duration of abdominal pain.

Ethoxyquin Inhibits the Progression of Murine Ehrlich Ascites Carcinoma through the Inhibition of Autophagy and LDH

Cancer cells exhibit an increased glycolysis rate for ATP generation (the Warburg effect) to sustain an increased proliferation rate. In tumor cells, the oxidation of pyruvate in the Krebs cycle is substituted by lactate production, catalyzed by LDH. In this study, we use ethoxyquin (EQ) as a novel inhibitor to target LDH in murine Ehrlich ascites carcinoma (EAC) and as a combination therapy to improve the therapeutic efficacy of the conventional chemotherapy drug, cisplatin (CIS). We investigated the anti-tumor effect of EQ on EAC-bearing mice and checked whether EQ can sustain the anti-tumor potential of CIS and whether it influences LDH activity. Treatment with EQ had evident anti-tumor effects on EAC as revealed by the remarkable decrease in the expression of the anti-apoptotic gene Bcl-2 and by a significant increase in the expression of apoptotic genes (BAX and caspase-3). EQ also caused a significant decrease in the autophagic activity of EAC cells, as shown by a reduction in the fluorescence intensity of the autophagosome marker. Additionally, EQ restored the altered hematological and biochemical parameters and improved the disrupted hepatic tissues of EAC-bearing mice. Co-administration of EQ and CIS showed the highest anti-tumor effect against EAC. Collectively, our findings propose EQ as a novel inhibitor of LDH in cancer cells and as a combinatory drug to increase the efficacy of cisplatin. Further studies are required to validate this therapeutic strategy in different cancer models and preclinical trials.

Prognostic Significance of Lactate Dehydrogenase in Patients Undergoing Surgical Resection for Laryngeal Squamous Cell Carcinoma

The aim is to estimate the prognostic value of lactate dehydrogenase (LDH) in patients undergoing surgical resection for laryngeal squamous cell carcinoma (LSCC). A total of 640 resected LSCC patients were included. Preoperative lactate dehydrogenase (LDH) was assessed. Kaplan-Meier survival analysis and Cox regression analysis were conducted for overall survival (OS) and recurrence-free survival (RFS). Kaplan-Meier analysis, univariate analysis and multivariate analysis demonstrated significant prognostic value for preoperative LDH. Although LDH was predictor of OS, it failed to be a predictor of RFS. The univariate HR and 95% CI of LDH were 0.484 and 0.357-0.658 (P < 0.0001). The multivariate analysis showed that LDH (HR = 0.518, 95% CI: 0.380-0.705, p < 0.0001) was related to OS. Elevated preoperative LDH >132 IU/L was significantly associated with better survival. Preoperative LDH might be an independent prognostic marker of OS in LSCC patients undergoing surgical resection.

Opposed Interplay between IDH1 Mutations and the WNT/β-Catenin Pathway: Added Information for Glioma Classification

Gliomas are the main common primary intraparenchymal brain tumor in the central nervous system (CNS), with approximately 7% of the death caused by cancers. In the WHO 2016 classification, molecular dysregulations are part of the definition of particular brain tumor entities for the first time. Nevertheless, the underlying molecular mechanisms remain unclear. Several studies have shown that 75% to 80% of secondary glioblastoma (GBM) showed IDH1 mutations, whereas only 5% of primary GBM have IDH1 mutations. IDH1 mutations lead to better overall survival in gliomas patients. IDH1 mutations are associated with lower stimulation of the HIF-1α a, aerobic glycolysis and angiogenesis. The stimulation of HIF-1α and the process of angiogenesis appears to be activated only when hypoxia occurs in IDH1-mutated gliomas. In contrast, the observed upregulation of the canonical WNT/β-catenin pathway in gliomas is associated with proliferation, invasion, aggressive-ness and angiogenesis.. Molecular pathways of the malignancy process are involved in early stages of WNT/β-catenin pathway-activated-gliomas, and this even under normoxic conditions. IDH1 mutations lead to decreased activity of the WNT/β-catenin pathway and its enzymatic targets. The opposed interplay between IDH1 mutations and the canonical WNT/β-catenin pathway in gliomas could participate in better understanding of the observed evolution of different tumors and could reinforce the glioma classification.

Designed β-Hairpins Inhibit LDH5 Oligomerization and Enzymatic Activity

Lactate dehydrogenase 5 (LDH5) is overexpressed in metastatic tumors and is an attractive target for anticancer therapy. Small-molecule drugs have been developed to target the substrate/cofactor sites of LDH5, but none has reached the clinic to date, and alternative strategies remain almost unexplored. Combining rational and computer-based approaches, we identified peptidic sequences with high affinity toward a β-sheet region that is involved in protein-protein interactions (PPIs) required for the activity of LDH5. To improve stability and potency, these sequences were grafted into a cyclic cell-penetrating β-hairpin peptide scaffold. The lead grafted peptide, cGmC9, inhibited LDH5 activity in vitro in low micromolar range and more efficiently than the small-molecule inhibitor GNE-140. cGmC9 inhibits LDH5 by targeting an interface unlikely to be inhibited by small-molecule drugs. This lead will guide the development of new LDH5 inhibitors and challenges the landscape of drug discovery programs exclusively dedicated to small molecules.

Underfilling of vacuum blood collection tubes leads to increased lactate dehydrogenase activity in serum and heparin plasma samples

Background Lactate dehydrogenase (LD) activity is routinely monitored for therapeutic risk stratification of malignant diseases, but is also prone to preanalytical influences. Methods We systematically analyzed the impact of defined preanalytical conditions on the hemolysis-susceptible parameters LD, potassium (K) and hemolysis index in vacuum blood collection tubes (serum [SE], heparin plasma [HP]). Blood was collected by venipuncture from healthy volunteers. Tubes were either filled or underfilled to approximately 50%, then processed directly or stored at room temperature for 4 h. Potassium (K), sodium (Na), chloride (Cl), LD, creatine kinase (CK), total cholesterol, and indices for hemolysis, icterus, and lipemia were analyzed. Filling velocity was determined in a subset of tubes. Findings in healthy volunteers were reconfirmed in an in-patient cohort (n = 74,751) that was analyzed for plasma yield and LD data distribution. Results LD activity was higher in HP compared to SE. Underfilling led to higher LD values (SE: +21.6%; HP: +28.3%), K (SE: +4.2%; HP: +5.3%), and hemolysis index (SE: +260.8%; HP: +210.0%), while other analytes remained largely unchanged. Filling velocity of tubes was approximately 3-fold higher in the first half compared to the second half in both HP and SE collection tubes. Importantly, plasma yield also inversely correlated with LD in routine patients. By calculating reference limits, the lowest plasma yield quartile of the patient cohort displayed LD values clearly exceeding current reference recommendations. Conclusions Underfilling of tubes leads to a higher proportion of blood aspirated with high velocity and relevant elevations in LD. This finding should be considered in cases of clinically implausible elevated LD activities.

The correlation of clinicopathological features and prognosis in extranodal natural killer/T cell lymphoma: a report of 42 cases in the early stage

This study aimed to explore the clinicopathological features and prognostic correlation of extranodal natural killer (NK)/T cell lymphoma (ENKTCL) in the early stage, screen out the prognostic markers of ENKTCL, and to establish the molecular model of ENKTCL prognosis. A retrospective study was conducted in 88 patients from May 1999 to Dec 2013 in Chinese Academy of Medical Sciences Cancer Hospital, who were diagnosed with ENKTCL according to WHO lymphoid hematopoietic tumor classification (published in 2008). The clinical data and paraffin-embedded tissue blocks were collected. The expressions of CD56, MLH1, PDGFRA, VEGF, PD-L1, PD-1, CyclinD1, p53, and Ki-67 were detected by high-throughput tissue microarray and immunohistochemistry (IHC) staining. The relationship between nine protein expressions and the clinicopathological features and prognosis of patients with ENKTCL were analyzed. The survival time of the 42 patients with complete clinical and follow-up data was 0~153 months. The average survival time was 60.1 months. The survival rates of 1 year, 2 years, and 3 year were 85.7%, 78.6%, and 71.4%, respectively. Single factor survival analysis showed that the increase of serum lactate dehydrogenase (LDH ≥ 240UI/L) before treatment was associated with poor prognosis, and there was a significant difference in survival rate (P = 0.006). Different therapy methods were related with prognosis (P = 0.011); in specifically, radiotherapy alone had the best treatment effect, followed by concurrent chemoradiotherapy, and the worst was chemotherapy alone. But, multivariate statistics indicated that the LDH level and the treatment approach were not independent prognostic factors of ENKTCL. There was no statistical difference between epidemiological factors such as gender, age, and other clinicopathological factors including tumor location, B symptoms, β2-microglobulin levels before treatment, and prognosis. Survival analysis of single factor showed that the positive expression of PDGFRA and PD-L1 was, respectively, related to the poor prognosis of patients with ENKTCL (P = 0.040, 0.007). The patients with Ki-67 overexpression (≥ 50%) had a worse prognosis than those with lower expression (< 50%), and the difference of survival rate between the two groups has statistical significance (P = 0.038). The expression of CD56, MLH1, VEGF, PD-1, CyclinD1, and p53 has no effect on survival rate (P > 0.05). Multivariate survival analysis showed that the expression levels of PDGFRA, PD-L1, and Ki-67 were independent factors in the prognosis of patients with ENKTCL. And the positive expressions of these three proteins were risk factors for prognosis of patients with ENKTCL (PDGFRA: P = 0.045, HR = 8.265, 95% CI: 1.050-65.054; PD-L1: P = 0.005, HR = 9.369, 95% CI: 1.950-45.003; Ki-67: P = 0.023, HR = 3.545, 95% CI: 1.187-10.585). The elevation of serum lactate dehydrogenase (LDH ≥ 240UI/L) before treatment and the treatment approach were associated with poor prognosis, which could be used as adjunct indexes to the prognosis. However, they were not independent factors for the prognosis of patients with ENKTCL. The expressions of PDGFRA, PD-L1, and Ki-67 were independent factors in the prognosis of patients with ENKTCL and these three proteins were risk factors of prognosis. The above markers combined with clinical factors may establish the prognosis model of ENKTCL.

Lactate dehydrogenase A: A key player in carcinogenesis and potential target in cancer therapy

Elevated glycolysis remains a universal and primary character of cancer metabolism, which deeply depends on dysregulated metabolic enzymes. Lactate dehydrogenase A (LDHA) facilitates glycolytic process by converting pyruvate to lactate. Numerous researches demonstrate LDHA has an aberrantly high expression in multiple cancers, which is associated with malignant progression. In this review, we summarized LDHA function in cancer research. First, we gave an introduction of structure, location, and basic function of LDHA. Following, we discussed the transcription and activation mode of LDHA. Further, we focused on the function of LDHA in cancer bio‐characteristics. Later, we discussed the clinical practice of LDHA in cancer prevention and treatment. What we discussed gives a precise insight into LDHA especially in cancer research, which will contribute to exploring cancer pathogenesis and its handling measures.

Vasculogenesis and angiogenesis initiation under normoxic conditions through Wnt/β-catenin pathway in gliomas

The canonical Wnt/β-catenin pathway is up-regulated in gliomas and involved in proliferation, invasion, apoptosis, vasculogenesis and angiogenesis. Nuclear β-catenin accumulation correlates with malignancy. Hypoxia activates hypoxia-inducible factor (HIF)-1α by inhibiting HIF-1α prolyl hydroxylation, which promotes glycolytic energy metabolism, vasculogenesis and angiogenesis, whereas HIF-1α is degraded by the HIF prolyl hydroxylase under normoxic conditions. We focus this review on the links between the activated Wnt/β-catenin pathway and the mechanisms underlying vasculogenesis and angiogenesis through HIF-1α under normoxic conditions in gliomas. Wnt-induced epidermal growth factor receptor/phosphatidylinositol 3-kinase (PI3K)/Akt signaling, Wnt-induced signal transducers and activators of transcription 3 (STAT3) signaling, and Wnt/β-catenin target gene transduction (c-Myc) can activate HIF-1α in a hypoxia-independent manner. The PI3K/Akt/mammalian target of rapamycin pathway activates HIF-1α through eukaryotic translation initiation factor 4E-binding protein 1 and STAT3. The β-catenin/T-cell factor 4 complex directly binds to STAT3 and activates HIF-1α, which up-regulates the Wnt/β-catenin target genes cyclin D1 and c-Myc in a positive feedback loop. Phosphorylated STAT3 by interleukin-6 or leukemia inhibitory factor activates HIF-1α even under normoxic conditions. The activation of the Wnt/β-catenin pathway induces, via the Wnt target genes c-Myc and cyclin D1 or via HIF-1α, gene transactivation encoding aerobic glycolysis enzymes, such as glucose transporter, hexokinase 2, pyruvate kinase M2, pyruvate dehydrogenase kinase 1 and lactate dehydrogenase-A, leading to lactate production, as the primary alternative of ATP, at all oxygen levels, even in normoxic conditions. Lactate released by glioma cells via the monocarboxylate lactate transporter-1 up-regulated by HIF-1α and lactate anion activates HIF-1α in normoxic endothelial cells by inhibiting HIF-1α prolyl hydroxylation and preventing HIF labeling by the von Hippel-Lindau protein. Increased lactate with acid environment and HIF-1α overexpression induce the vascular endothelial growth factor (VEGF) pathway of vasculogenesis and angiogenesis under normoxic conditions. Hypoxia and acidic pH have no synergistic effect on VEGF transcription.

Prevention and treatment of bleomycin-induced pulmonary fibrosis with the lactate dehydrogenase inhibitor gossypol

Pulmonary fibrosis is a chronic and irreversible scarring disease in the lung with poor prognosis. Few therapies are available; therefore it is critical to identify new therapeutic targets. Our lab has previously identified the enzyme lactate dehydrogenase-A (LDHA) as a potential therapeutic target in pulmonary fibrosis. We found increases in LDHA protein and its metabolic product, lactate, in patients with idiopathic pulmonary fibrosis (IPF). Importantly, we described lactate as a novel pro-fibrotic mediator by acidifying the extracellular space, and activating latent transforming growth factor beta (TGF-β1) in a pH-dependent manner. We propose a pro-fibrotic feed-forward loop by which LDHA produces lactate, lactate decreases pH in the extracellular space and activates TGF-β1 which can further perpetuate fibrotic signaling. Our previous work also demonstrates that the LDHA inhibitor gossypol inhibits TGF-β1-induced myofibroblast differentiation and collagen production in vitro. Here, we employed a mouse model of bleomycin-induced pulmonary fibrosis to test whether gossypol inhibits pulmonary fibrosis in vivo. We found that gossypol dose-dependently inhibits bleomycin-induced collagen accumulation and TGF-β1 activation in mouse lungs when treatment is started on the same day as bleomycin administration. Importantly, gossypol was also effective at treating collagen accumulation when delayed 7 days following bleomycin. Our results demonstrate that inhibition of LDHA with the inhibitor gossypol is effective at both preventing and treating bleomycin-induced pulmonary fibrosis, and suggests that LDHA may be a potential therapeutic target for pulmonary fibrosis.

Effect of HK2, PKM2 and LDHA on Cetuximab efficacy in metastatic colorectal cancer

Although hexokinase (HK) 2, pyruvate kinase muscle (PKM) isozyme 2 and lactate dehydrogenase (LDH) A predict the efficacy of medicines in various solid tumors, their ability to predict the efficacy of cetuximab in metastatic colorectal cancer (mCRC) remains unclear. mCRC patients with pathological specimens who received cetuximab and chemotherapy from 2005 to 2015 in the present institution were enrolled. Immunohistochemistry was used to detect HK2, PKM2 and LDHA expression. SPSS20 was used for statistical analysis. A total of 68 patients were included; 33 received cetuximab plus chemotherapy as first-line therapy, and the rest, as second- or later-line therapy. HK2 expression levels were increased in cancer compared with normal tissue (75.4% vs. 40%; P<0.001), however PKM2 (P=0.243) and LDHA (P=0.067) expression levels were not. For progression-free survival (PFS) with first-line cetuximab plus chemotherapy, patients with high HK2 expression exhibited longer PFS compared with those with low HK2 expression (23.9 months vs. 6.9 months; P=0.021). However, this positive association was absent in 35 cases administered first-line chemotherapy alone (13.4 months vs. 13.5 months; P=0.539). LDHA expression was associated with the PFS of patients receiving first-line chemotherapy (18.3 and 10.1 months for high and low expression, respectively; P=0.005), whereas this association was absent in cetuximab plus chemotherapy cases (19.9 months vs. 12 months; P=0.522). Furthermore, high LDHA expression correlated with high overall response rate (ORR) (72.2% vs. 15.4%, P=0.006) for chemotherapy, however not disease control rate (DCR) (P=0.074). Neither DCR nor ORR were associated with HK2 expression. PKM2 expression did not affect PFS, DCR or ORR. LDHA expression (P=0.005), pathological differentiation (P=0.019) and synchronous/metachronous metastasis (P=0.014) were independent predictive factors of PFS for all first-line patients, and tumor differentiation (P=0.002) was associated with overall survival (OS) in multivariate analysis. HK2, PKM2 and LDHA did not impact OS. It was concluded that HK2 expression was increased in colorectal cancer tissue and may predict cetuximab efficacy and LDHA for chemotherapy treatment of mCRC.

Clinical analysis of 42 cases of EBV-positive mature T/NK-cell neoplasms

The pathogenesis of Epstein-Barr virus-positive (EBV⁺) mature T-cell and natural killer (NK)-cell neoplasms is challenging to understand. The clinical features are diverse, with no typical manifestation. Therefore, it is important to analyze the association of the clinical characteristics and prognoses of patients with various factors associated with EBV⁺ T/NK-cell neoplasms, particularly extranodal NK/T cell lymphoma, systemic EBV⁺ T/NK cell lymphoproliferative disorders, aggressive NK cell leukemia and EBV⁺ peripheral T-cell lymphoma. Therefore, 42 cases of EBV⁺ T/NK-cell neoplasms with information on age, gender, fever, LDH level, complete blood count (CBC) and immunophenotype (CD5/CD20) were retrospectively analyzed to examine the clinical features, prognoses and related factors. It was found that patients ≤60 years old accounted for 86% of cases. The frequency of stage III/IV disease was higher in groups with pancytopenia (P=0.005), high LDH level (P=0.020), CD5-expression status (P=0.031) and fever (P=0.024). There were significant differences in the mean International Prognostic Index (IPI) scores according to the presence or absence of fever (P=0.022), elevated or normal lactose dehydrogenase (LDH) levels (P=0.001), and pancytopenia or normal complete blood count (CBC; P=0.046). Analysis of overall survival showed that CD5 expression, CBC, IPI scores and LDH levels were factors associated with OS. CD5 expression (P=0.003), CBC (P=0.003) and IPI scores (P=0.017) were identified to be important risk factors on the basis of Cox regression analysis. The mean survival time was longer in the CD5⁺, CD20⁺ and normal CBC groups, and there was no clear difference in survival time according to LDH level or fever. In summary, CD5 and CD20 may be prognostic factors in EBV⁺ T/NK lymphoid neoplasms, and CBC and fever are most likely to influence the IPI score and Ann Arbor stage.

COPS5 amplification and overexpression confers tamoxifen-resistance in ERα-positive breast cancer by degradation of NCoR

Oestrogen receptor α (ERα) antagonists are used in endocrine therapies for ERα-positive (ERα+) breast cancer patients. Unfortunately the clinical benefit is limited due to intrinsic and acquired drug resistance. Here using integrated genomic and functional studies, we report that amplification and/or overexpression of COPS5 (CSN5/JAB1) confers resistance to tamoxifen. Amplification and overexpression of COPS5, a catalytic subunit of the COP9 complex, is present in about 9% of the ERα+ primary breast cancer and more frequently (86.7%, 26/30) in tamoxifen-refractory tumours. Overexpression of COPS5, through its isopeptidase activity, leads to ubiquitination and proteasome-mediated degradation of NCoR, a key corepressor for ERα and tamoxifen-mediated suppression of ERα target genes. Importantly, COPS5 overexpression causes tamoxifen-resistance in preclinical breast cancer models in vitro and in vivo. We also demonstrate that genetic inhibition of the isopeptidase activity of COPS5 is sufficient to re-sensitize the resistant breast cancer cells to tamoxifen-treatment, offering a potential therapeutic approach for endocrine-resistant breast cancer patients.

The corepressor NCoR is required for tamoxifen-mediated ERα-dependent transcriptional repression. Here, the authors show that COPS5 confers tamoxifen-resistance through the degradation of NCOR, the recruitment of the co-activator PCAF to ERα binding sites and the subsequent ERα transcriptional activity.

The Actual Role of LDH as Tumor Marker, Biochemical and Clinical Aspects

Lactate dehydrogenase (LDH) among many biochemical parameters represents a very valuable enzyme in patients with cancer with possibility for easy routine measurement in many clinical laboratories. Previous studies where mostly based on investigated LDH in serum of patients with cancer with aims to estimate their clinical significance. The new directions in investigation of LDH where based on the principle that tumor cells release intracellular enzymes trough damaged cell membrane, that is mostly consequence in intracellular mitochondrial machinery alteration, and apoptosis deregulation. This consideration can be used not only in-vitro assays, but also in respect to clinical characteristics of tumor patients. Based on new techniques of molecular biology it is shown that intracellular characteristics of LDH enzyme are very sensitive indicators of the cellular metabolic state, aerobic or anaerobic direction of glycolysis, activation status and malignant transformation. Using different molecular analyses it is very useful to analyzed intracellular LDH activity in different cell line and tumor tissues obtained from patients, not only to understanding complexity in cancer biochemistry but also in early clinical diagnosis. Based on understandings of the LDH altered metabolism, new therapy option is created with aims to blocking certain metabolic pathways and stop tumors growth.

Equating salivary lactate dehydrogenase (LDH) with LDH-5 expression in patients with oral squamous cell carcinoma: An insight into metabolic reprogramming of cancer cell as a predictor of aggressive phenotype

Oral squamous cell carcinoma (OSCC) is the sixth most common human malignancy. According to World Health Organization, oral cancer has been reported to have the highest morbidity and mortality and a survival rate of approximately 50 % at 5 years from diagnosis. This is attributed to the subjectivity in TNM staging and histological grading which may result in less than optimum treatment outcomes including tumour recurrence. One of the hallmarks of cancer is aerobic glycolysis also known as the Warburg effect. This glycolytic phenotype (hypoxic state) not only confers immortality to cancer cells, but also correlates with the belligerent behaviour of various malignancies and is reflected as an increase in the expression of lactate dehydrogenase 5 (LDH-5), the main isoform of LDH catalysing the conversion of pyruvate to lactate during glycolysis. The diagnostic role of salivary LDH in assessing the metabolic phenotype of oral cancer has not been studied. Since salivary LDH is mainly sourced from oral epithelial cells, any pathological changes in the epithelium should reflect diagnostically in saliva. Thus in our current research, we made an attempt to ascertain the biological behaviour and aggressiveness of OSCC by appraising its metabolic phenotype as indirectly reflected in salivary LDH activity. We found that salivary LDH can be used to assess the aggressiveness of different histological grades of OSCC. For the first time, an evidence of differing metabolic behaviour in similar histologic tumour grade is presented. Taken together, our study examines the inclusion of salivary LDH as potential diagnostic parameter and therapeutic index in OSCC.

The Regulation and Function of Lactate Dehydrogenase A: Therapeutic Potential in Brain Tumor

There are over 120 types of brain tumor and approximately 45% of primary brain tumors are gliomas, of which glioblastoma multiforme (GBM) is the most common and aggressive with a median survival rate of 14 months. Despite progress in our knowledge, current therapies are unable to effectively combat primary brain tumors and patient survival remains poor. Tumor metabolism is important to consider in therapeutic approaches and is the focus of numerous research investigations. Lactate dehydrogenase A (LDHA) is a cytosolic enzyme, predominantly involved in anaerobic and aerobic glycolysis (the Warburg effect); however, it has multiple additional functions in non‐neoplastic and neoplastic tissues, which are not commonly known or discussed. This review summarizes what is currently known about the function of LDHA and identifies areas that would benefit from further exploration. The current knowledge of the role of LDHA in the brain and its potential as a therapeutic target for brain tumors will also be highlighted. The Warburg effect appears to be universal in tumors, including primary brain tumors, and LDHA (because of its involvement with this process) has been identified as a potential therapeutic target. Currently, there are, however, no suitable LDHA inhibitors available for tumor therapies in the clinic.

Spleen-specific isoforms of Pax5 and Ataxin-7 as potential proteomic markers of lymphoma-affected spleen

The splenomegaly, enlargement of spleen, has been observed in several diseases. It has been intended to evaluate histochemical alterations, spleen-specific enzymatic and proteomic markers during splenomegaly, and lympho-proliferative disorders from spleen of mice bearing Dalton's lymphoma. The higher expression of c-fos, c-jun, and MAPK testifies proliferation of lymphocytes. The lower expression of Pax5, higher expression of CD3, and the presence of additional form of Zap-70 suggest hypertrophy of follicles and splenomegaly influenced by weak B-cell receptor-mediated signaling, but activated T-cell receptor-mediated signaling. Simultaneously, lower levels of SOD, NDR2, and MIB2 and higher expression levels of Ataxin-7 and LDH also suggest impact of stress either as a cause or effect of cell proliferation. Spleen-specific isoform of Pax5, NDR2, MIB2, and Ataxin-7 can be considered as spleen-specific unique molecular markers for the evaluation of splenomegaly and lympho-proliferative disorders.

Lactate dehydrogenase 5: an old friend and a new hope in the war on cancer

A hallmark of most cancer cells is an altered metabolism involving a shift to aerobic glycolysis with lactate production coupled with a higher uptake of glucose as the main source of energy. Lactate dehydrogenase 5 (LDH-5) catalyzes the reduction of pyruvate by NADH to form lactate, thus determining the availability of NAD(+) to maintain the continuity of glycolysis. It is therefore an important control point in the system of cellular energy release. Its upregulation is common in many malignant tumors. Inhibiting LDH-5 activity has an anti-proliferative effect on cancer cells. It may reverse their resistance to conventional chemo- and radiotherapy. Recent research has renewed interest in LDH-5 as an anticancer drug target. This review summarizes recent studies exploring the role of LDH-5 in cancer growth, its utility as a tumor marker, and developments made in identifying and designing anti-LDH-5 therapeutic agents.