The Diagnostic and Prognostic Value of the Combination of Tumor M2-Pyruvate Kinase, Carcinoembryonic Antigen, and Cytokeratin 19 Fragment in Non-Small Cell Lung Cancer.

Objective: Finding biomarkers related to non-small cell lung cancer (NSCLC) is helpful for the diagnosis and precise treatment of lung cancer. The relationship between serum tumor M2-pyruvate kinase (TuM2-PK), carcinoembryonic antigen (CEA), and cytokeratin 19 fragment (CYFRA21-1) and NSCLC was analyzed. Methods: The serum levels of TuM2-PK, CEA, and CYFRA21-1 in 184 patients with the NSCLC group, 60 patients with the benign lung disease (BLD) group, and 90 healthy controls (HC) group were detected. The levels of TuM2-PK were measured by using an enzyme-linked immunosorbent assay. The detection methods of CEA and CYFRA21-1 were electrochemiluminescence. The receiver operating characteristic (ROC) curve was drawn to evaluate the diagnostic value of TuM2-PK, CEA, and CYFRA21-1 on NSCLC. The Kaplan-Meier survival curve was drawn to evaluate the survival status in NSCLC patients with different serum levels of TuM2-PK, CEA, and CYFRA21-1. Results: Serum levels of TuM2-PK, CEA, and CYFRA21-1 in the NSCLC group were significantly higher than those in the BLD group and the HC group (P < .01). Serum levels of TuM2-PK, CEA, and CYFRA21-1 in NSCLC patients were associated with the tumor lymph node metastasis stage (P < .05), lymph node metastasis (P < .05), and distant metastasis (P < .05). The ROC curve showed that the area under the curve of serum levels of TuM2-PK, CEA, and CYFRA21-1 was 0.814, 0.638, and 0.719, respectively, and that the combination of the above 3 was 0.918. The Kaplan-Meier survival curve showed that the 1-, 3- and 5-year survival rate in NSCLC patients with positive TuM2-PK, CEA, and CYFRA21-1 was significantly lower than that in NSCLC patients with negative TuM2-PK, CEA, and CYFRA21-1, respectively (P < .05). Conclusions: Serum TuM2-PK, CEA, and CYFRA21-1 levels have high clinical values in the diagnosis of NSCLC, and can effectively judge the prognosis of patients.

MITOCHONDRIAL VITIATION CONGRUENTLY APTLY WITH AUTISM SPECTRUM DISORDER.

Mitochondrial dysfunction in autism leads to impair the mitochondria's ability to synthesis adenosine triphosphate (ATP) by impairment citric acid cycle as well as increase anaerobic glycolysis. Aim - measuring and evaluating the levels of mitochondrial markers; including glutamate oxaloacetate transaminase (GOT), glutamate pyruvate transaminase (GPT), malate dehydrogenase, and pyruvate kinase) in the autistic group and knowing the possibility of using these markers to diagnose children with autism spectrum disorder. A case-control study was done in the Al-Zahraa Teaching Hospital (Kut City, Iraq) on 100 Iraqi children (male and female), between (April 2023 and January 2024). Their ages ranged between 3 and 9 years. Among them were 50 patients enrolled as autistic group and 50 healthy enrolled as control group. Blood samples were collected and bioassays for GOT, GPT, pyruvate kinase, and malate dehydrogenase were measured by ELISA technique. The autistic group showed that the urine GOT, urine GPT, serum malate, and serum pyruvate levels in the ASD group was significantly higher (P<0.001) than the control group. The ROC analysis showed that urine GOT, urine GOT, serum malate and serum pyruvate had an accuracy level of (81%,71%,77%, and 80 %) and the area under the curve (AUC) was > 0.7 (0.8),0.7, 0.7(0.76), and 0.7(0.8) thus urine GOT, urine GPT, serum, malate, and serum pyruvate are a valid diagnostic marker. There was a significant difference in the mean urine and serum concentrations of mitochondrial markers (GOT, GPT, malate dehydrogenase, and pyruvate kinase) between autistic children and the control group due to mitochondrial dysfunction.

Serum tumour M2-pyruvate kinase as a biomarker for diagnosis and prognosis of early-stage non-small cell lung cancer.

Tumour M2-pyruvate kinase (TUM2-PK) is up-regulated in many human cancers. This study was to evaluate the clinical value of serum TUM2-PK in early-stage non-small cell lung cancer (NSCLC) patients. A total of 162 consecutive early-stage NSCLC patients were enrolled and followed up after tumour resection. Serum TUM2-PK level was detected by enzyme-linked immunosorbent assay (ELISA) in NSCLC patients, 50 benign pulmonary disease patients and 102 healthy controls. The TUM2-PK level in NSCLC patients was higher than that of healthy controls (P < .001) and benign pulmonary disease patients (P < .001). A threshold of 30 U/mL could be used to diagnose early-stage NSCLC with 71.6% sensitivity and 98.0% specificity. The 5-year overall survival rate in patients with high TUM2-PK level was lower than that of patients with low TUM2-PK level (P = .009). Multivariable Cox regression showed that high TUM2-PK level was an independent risk factor for overall survival (HR = 2.595, 95% CI: 1.231-5.474, P = .012). High serum TUM2-PK level could be a potential biomarker for diagnosis and prognosis of early-stage NSCLC patients.

A New Variant of PKLR Gene Associated With Mild Hemolysis may be Responsible for the Misdiagnosis in Pyruvate Kinase Deficiency.

Pyruvate kinase deficiency (PKD) is the most common glycolytic defect leading to hemolytic anemia. PKD is caused by the mutations in the PKLR gene; however, the detection of a decreased PK activity should be first measured for rapid diagnosis. We report here the case of a 1-year-old girl with mild hemolysis and PKD. At the time of the study, the patient showed a hemoglobin level of 9.5 g/dL, mean corpuscular volume of 93 fL, reticulocyte of 6.7%, and lactate dehydrogenase of 218 IU/L. Peripheral blood smear showed polychromasia, anisocytosis, tear drop cells, fragmented eyrtrocytes, and target cells. When a biochemical analysis was performed in our patient and her parents who had consanguinity, a decreased PK activity was detected in the patient and her father. After the molecular study of PKLR gene, a new homozygote variant, c.1708G>T (pVal570Leu), was found in our patient and her father. Her father had a misdiagnosis of Gilbert syndrome because he had unconjugated hyperbilirubinemia and not anemia. Her mother was also a carrier of the mutation in heterozygous state. Patients presenting with hemolytic anemia, either severe or mild hemolytic anemia, should be screened for PKD in the first year of life. Patients with mild hemolytic findings can be followed-up with misdiagnoses.

Involvement of the phosphoryl transfer network on cardiac energetic metabolism during Staphylococcus aureus infection and its association to disease pathophysiology.

Evidences have suggested that the phosphoryl transfer network by the enzymatic activities of creatine kinase (CK), adenylate kinase (AK), pyruvate kinase (PK), and lactate dehydrogenase (LDH), shows new perspectives to understand some disturbances in the energy metabolism during bacterial infections. Thus, the aim of this study was to evaluate whether Staphylococcus aureus infection in mice could alter serum and cardiac activities of these enzymes and their association to disease pathophysiology. For that, we measured total leukocytes, lymphocytes and neutrophils (just 48 h of infection) that were lower in infected animals after 48 and 72 h in infected mice compared with negative control, while total protein and globulin plasma levels were higher after 72 h of infection. The serum CK activity was higher in infected animals 48 and 72 h post-infection compared to the control group, as well as observed for mitochondrial cardiac CK activity. The serum PK activity was higher in infected animals after 72 h of infection compared to the control group, and lower in the cardiac tissue. The cardiac AK activity was lower in infected animals 48 h and 72 h post-infection compared to the control group, while serum and cardiac LDH activities were higher. Based on these evidences, it is possible to conclude that the stimulation of CK activity exerts a key role as an attempt to maintain the bioenergetic homeostasis by the production of phosphocreatine to avoid a rapid fall on the concentrations of total adenosine triphosphate. In summary, the phosphoryl transfer network can be considered a pathway involved in the improvement on tissue and cellular energy homeostasis of S. aureus-infected mice.

B Vitamins Can Reduce Body Weight Gain by Increasing Metabolism-related Enzyme Activities in Rats Fed on a High-Fat Diet.

B vitamins are enzyme cofactors that play an important role in energy metabolism. The aim of this study was to elucidate whether B vitamin administration can reduce body weight (BW) gain by improving energy metabolism-related enzyme activities in rats fed on a highfat diet. Fifty rats were randomly assigned to one of the following five groups: control group (C), including rats fed on standard rat chow; four treatment groups (HO, HI, H2, and H3), in which rats were fed on a high-fat diet. Rats in the HI group were treated daily with 100 mg/kg BW thiamine (VB1), 100 mg/kg BW riboflavin (VB2), and 250 mg/kg BW niacin (VPP); rats in the H2 group were treated daily with 100 mg/kg BW pyridoxine (VB6), 100 mg/kg BW cobalamin (VB12), and 5 mg/kg BW folate (FA); and rats in the H3 group were treated daily with all of the B vitamins administered to the HI and H2 groups. After 12 weeks, the BW gains from the initial value were 154.5±58.4 g and 159.1±53.0 g in the HI and C groups, respectively, which were significantly less than the changes in the HO group (285.2±14.8 g, P<0.05). In the HO group, the plasma total cholesterol (CHO) and triglyceride (TG) levels were 1.59±0.30 mmol/L and 1,55±0.40 mmol/L, respectively, which were significantly greater than those in the HI group (1.19±0.18 mmol/L and 0.76±0.34 mmol/L, respectively, P<0.05). The activities of transketolase (TK), glutathione reductase, and Na+/K+ adenosine triphosphatase were significantly increased in the B vitamin-treated groups and were significantly greater than those in the HO group (P<0.05). Furthermore, the glucose-6-phosphate dehydrogenase, pyruvic acid kinase, and succinate dehydrogenase activities also were increased after treatment with B vitamins. Supplementation with B vitamins could effectively reduce BW gain and plasma levels of lipids by improving energy metabolism-related enzyme activities in rats, thus possibly providing potential benefits to humans.

The Diagnostic Value of Pyruvate Kinase Isoenzyme Type M2 for Biliary Tract Carcinoma. A Systematic Review and Meta-Analysis.

BACKGROUND AND AIMS: Growing evidence has shown that M2-PK is involved in cancer diagnosis and prognosis. The overall diagnostic accuracy of the pyruvate kinase isoenzyme type M2 (M2-PK) in biliary tract carcinoma (BTC) remains controversial. We performed a meta-analysis to evaluate the diagnostic value of M2-PK for BTC. METHODS: The online PubMed, Cochrane, Web of Science, and Embase databases were searched for eligible studies published until August 8th, 2017. The Quality Assessment for Diagnostic Accuracy Studies 2 (QUADAS-2) was used to evaluate study quality. All statistical analyses were conducted with Stata 12.0. RESULTS: We included 7 studies from 5 articles with 410 patients with BTC and 438 controls. The pooled sensitivity, specificity, positive likelihood ratio (PLR), negative likelihood ratio (NLR), diagnostic odds ratio (DOR), and AUC for M2-PK in the diagnosis of BTC were 0.79 (95%CI 0.70-0.86), 0.81 (95%CI 0.71-0.88), 4.1 (95%CI 2.5-6.8), 0.26 (95%CI 0.16-0.41), 17.159 (95%CI 5.468-54.071), and 0.87 (95%CI 0.83-0.89), respectively. The same indicators assessed for CA19-9 were as follows: 0.70 (95%CI 0.62-0.77), 0.71 (95%CI 0.45-0.87), 2.38 (95%CI 1.2-4.73), 0.43 (95%CI 0.34-0.53), 6.28 (95%CI 2.4-16.44) and 0.73 (95%CI 0.69-0.77), respectively. Additionally, the diagnostic value of M2-PK varied based on characteristics of golden methods and different cut-off values. CONCLUSIONS: This meta-analysis showed that M2-PK had a better diagnostic accuracy for BTC compared with CA19-9, with moderate diagnostic performance. However, prospective studies are required to confirm its diagnostic value.

Evaluation of tumor M2-pyruvate kinase (Tumor M2-PK) as a biomarker for pancreatic cancer.

BACKGROUND: Expression of the dimeric M2 isoenzyme of pyruvate kinase, termed Tumor M2-PK, is increased in some human cancers. This study evaluates the potential role of pre-operative Tumor M2-PK as a marker of prognosis in patients with pancreatic malignancy. METHODS: Seventy-three consecutive patients with a clinical diagnosis of pancreatic or peri-ampullary cancer were enrolled. Their median (range) age was 66 (23-83) years. Pre-operative samples of venous blood were taken for analysis of Tumor M2-PK. The full study protocol was approved by the North West Research Ethics Committee (protocol number 06/MRE08/69). RESULTS: The mean (standard deviation) plasma Tumor M2-PK in pancreatic/peri-ampullary malignancy was 60.3 (106.5) U/ml and 22 U/ml (SD: 12 U/ml) in benign disease (p < 0.001). Multivariate Cox regression analysis showed that Tumor M2-PK (> 27 U/mL), Ca19-9 (> 39 U/ml), resection status, and disease stage were associated with poorer survival. Tumor M2-PK values greater than 27 U/ml were associated with inferior survival compared to those with lower values (hazard ratio 2.049, significantly increased risk of death, p = 0.042). CONCLUSION: This preliminary study shows that an elevated level of Tumor M2-PK (with a cutoff threshold of 27 U/mL) measured pre-operatively is associated with poorer prognosis in patients with pancreatic and peri-ampullary cancer.

Enzyme Kinetic Assay to Measure the Activity of Tumor M2 Pyruvate Kinase in Breast Cancer Patients.

BACKGROUND: M2 type Pyruvate kinase (PKM2) is the key rate-limiting enzyme of glycolysis, and it mainly exists as a dimer in tumor cells. This study aims to establish an enzyme kinetic assay for serum tumor M2 pyruvate kinase (TuM2-PK), and to evaluate its diagnostic value in breast cancer. METHODS: The catalytic kinetics of Pyruvate Kinase (PK) was examined. Its allosteric regulation property and Michaelis constant were then measured. Next, the levels of TuM2-PK in serum were detected and compared with results from an enzyme-linked immunosorbent assay (ELISA). Finally, the levels of TuM2-PK among breast cancer patients, post-mastectomy patients, patients with benign breast diseases, and healthy controls were compared. RESULTS: A PK kinetic assay was established in this study. The assay reaction time is 108 seconds, and the optimum pH level is 8.0. In the presence of the allosteric activator fructose 1, 6-bisphosphate (FBP), the Km of PK for phosphoenolpyruvate (PEP) is 0.15 mmol/L and the Vmax is 330 µmol/min. The levels of TuM2-PK in serum obtained by enzyme kinetics are comparable to the ELISA results. Both assays showed that TuM2-PK in breast cancer patients was increased from stage I to IV. Importantly, TuM2-PK levels were significantly different between early and late-stage breast cancer patients (stage I and stage II vs. stage III and IV), as well as between late-stage and non-malignant patients (p<0.05). No statistical difference was found between benign breast disease patients and healthy controls. CONCLUSIONS: An enzyme kinetic assay of serum TuM2-PK was successfully established and may be useful for breast cancer diagnosis.

Plasma TuM2-PK correlates with tumor size, CRP and CA 15-3 in metastatic breast carcinomas; short versus long term follow up study of the Egyptian breast cancer patients.

BACKGROUND: The key regulator of tumor metabolome is the glycolytic isoenzyme M2-PK which favors the generation of nucleic acid via glutaminolysis as hypoxic adaptive mechanism in the tumor cells. AIM: The study aimed to evaluate the prognostic role of M2-PK, CRP, and CA 15-3 in preoperative and metastatic breast carcinomas. PATIENTS AND METHODS: The study included 70 females; 15 controls, 33 preoperative primary breast carcinomas clinically metastasis free, and 22 clinically diagnosed metastatic breast carcinomas. M2-PK and CA 15-3 were detected by ELISA. CRP was quantified using the CRP LATEX kit. RESULTS: TuM2-PK significantly increased in metastatic and preoperative groups when compared to controls (p= 0.049, p= 0.001); respectively. Both CRP and CA 15-3 were significantly increased in metastatic than the preoperative group (p= 0.002). CA 15-3 was significantly increased in both groups when compared to controls (p= 0.016; p< 0.001; respectively). TuM2-PK level significantly related to tumor size in metastatic group (p= 0.006) and with menstruation status (p= 0.039), and liver metastasis (p= 0.036) in preoperative group. TuM2-PK significantly correlated with CRP (r= 0.793, p= 0.004), and CA 15-3 (r= 0.568, p= 0.006) in the metastatic group.Metastatic group with TuM2-PK ⩽ 15 U/ml had significantly higher survival rate than those with > 15 U/ml (χ2= 13.841, p< 0.001) within 3.3-4.2 but not after 10-20 years follow up period. Metastasis to bone and lymph nodes significantly increased in the metastatic than the preoperative group (p= 0.002, p= 0.013; respectively). Within 3.3-4.2 years, CA15.3 has the highest prognostic performance in metastatic group while both TuM2-PK and CRP have same specificity. On the other hand, TuM2-PK has the highest prognostic performance in preoperative group. After 20 years follow up period, there was neither significant difference in the performance of the three markers in predicting mortality in metastatic and preoperative groups nor in predicting metastasis in preoperative group. CONCLUSION: Current results document for the first time, a cross-talk between TuM2-PK and each of CRP and CA 15-3 in metastatic breast cancer.

Cord blood transplantation in a young child with pyruvate kinase deficiency.

Unrelated cord blood transplantation (CBT) was performed for the treatment of pyruvate kinase (PK) deficiency in a female pediatric patient at the age of 1 year 7 months, who had been in severe and frequent transfusion-dependent hemolytic anemia, despite red blood cell (RBC) PK activity 5.52 IU/gHb. pyruvate kinase-liver and RBC (PK-LR) had a compound heterozygous mutation located on exon 8: c.1044G > T/c.1076G > A (K348N/R359H). Hemoglobin and RBC PK corrected to 13.5 g/dL and 9.00 IU/gHb, respectively, with gene correction at 6 months after CBT. CBT should be considered as an option for useful treatment in children with severe PK deficiency in the absence of HLA identical sibling with normal RBC PK activity.

[THE BIOCHEMICAL AND PATHOPHYSIOLOGICAL MARKERS OF CHEMICAL EFFECT ON ORGANISM, THEIR INFORMATIVENESS AND DIAGNOSTIC SIGNIFICANCE].

The sampling of study included 185 examined workers. Out of them 90 work at "Opitnii zavod Neftekhim" (67 females and 23 males) and 95--at "Kaustik" (64 females and 31 males) from various workshops of the given enterprises. To determine biochemical indicators samples of blood, saliva and urine were collected. The study was carried out in concordance with ethic principles of the Helsinki world medical association declaration, 2008 ed. with receiving written consent of patient to participate in study.

Plasma Tumor M2-Pyruvate Kinase Levels in Different Cancer Types.

BACKGROUND/AIM: Tumor M2-pyruvate kinase (M2-PK) is up-regulated in proliferating tissues. It has been shown that tumor M2-PK is detectable and quantifiable in the stool and plasma of patients with colorectal cancer (CRC). Tumor M2-PK has been extensively studied in gastrointestinal tumors but its role in other cancer types has not yet been deeply evaluated. The aim of the study was to determine and compare plasma tumor M2-PK levels in different cancer types. MATERIALS AND METHODS: All patients undergoing diagnostics for cancer at our Hospital during 2011 were included in the study (n=139). Plasma tumor M2-PK concentration was analyzed by an enzyme-linked immunosorbent assay. RESULTS: The different cancer types found in the study were: 60 colorectal, 43 breast, 8 lung, 5 prostatic, 4 ovarian and the remaining 19 cases were other uncommon tumor types. Most tumors had high concentrations of tumor M2-PK; prostatic, pharyngeal and testicular tumors had levels lower than or near the cut-off. Plasma tumor M2-PK levels were significantly higher in patients with distant metastases and stage IV by TNM. CONCLUSION: Plasma tumor M2-PK is not a specific marker for CRC and is elevated in many other types of cancers, including breast, lung, ovarian, and thyroid. Small amounts are found in prostatic, pharyngeal and testicular tumors.

Serum inflammatory markers after rupture retinal laser injury in mice.

BACKGROUND AND OBJECTIVE: To characterize the cellular, immunological, and inflammatory response to retinal photocoagulation of intense rupture laser lesions as a model of retinal degenerative diseases. MATERIALS AND METHODS: Seven C57BL/6 mice were irradiated using a 532-nm laser to induce 10 retinal burns per eye that ruptured Bruch's membrane. Blood was drawn from the saphenous vein before and 2 months after laser treatment. The serum was run on antigen microarrays with 85 molecular markers associated with retinal degenerative diseases. RESULTS: Rupture laser resulted in dramatic changes in the immunoglobulin reactivity of most inflammatory markers 2 months after laser injury. Approximately two-thirds increased expression and one-third decreased expression. Notable markers that were increased included complement C3, CRP, PKM2, and aldolase. CONCLUSION: Rupture laser injury causes a change in the serum inflammatory markers after 2 months similar to macular degeneration, diabetic retinopathy, and cancer-associated retinopathy. This animal model could be used as a biomarker for disease stage and activity in retinal degenerations.

Prospective evaluation of plasma levels of ANGPT2, TuM2PK, and VEGF in patients with renal cell carcinoma.

BACKGROUND: To assess pathological correlations and temporal trends of Angiopoietin-2 (ANGPT2), vascular endothelial growth factor (VEGF) and M2 Pyruvate kinase (TuM2PK), markers of tumor vascular development and metabolism, in patients with renal cell carcinoma (RCC). METHODS: We prospectively collected plasma samples from 89 patients who underwent surgical/ablative therapy for RCC and 38 patients with benign disease (nephrolithiasis, hematuria without apparent neoplastic origin, or renal cysts). In RCC patients, marker levels were compared between at least 1 preoperative and 1 postoperative time point generally 3 weeks after surgery. Marker temporal trends were assessed using the Wilcoxon sign-rank test. Plasma VEGF, ANGPT2, and TuM2PK levels were determined by ELISA and tested for association with pathological variables. RESULTS: Median age was comparable between groups. 83/89 (93%) of the cohort underwent surgical extirpation. 82% of the tumors were organ confined (T ≤ 2, N0). Only ANGPT2 exhibited significantly elevated preoperative levels in patients with RCC compared to benign disease (p = 0.046). Elevated preoperative levels of ANGPT2 and TuM2PK significantly correlated with increased tumor size and advanced grade (p < 0.05). Chromophobe RCC exhibited higher levels of ANGPT2 compared to other histologies (p < 0.05). A decline in marker level after surgery was not observed, likely due to the timing of the analyses. CONCLUSION: Our results suggest that ANGPT2 is a marker of RCC. Additionally, ANGPT2 and TuM2PK significantly correlated with several adverse pathological features. Further studies are needed to determine clinical applicability.

Elevated levels of 14-3-3 proteins, serotonin, gamma enolase and pyruvate kinase identified in clinical samples from patients diagnosed with colorectal cancer.

BACKGROUND: Colorectal cancer (CRC), a heterogeneous disease that is common in both men and women, continues to be one of the predominant cancers worldwide. Lifestyle, diet, environmental factors and gene defects all contribute towards CRC development risk. Therefore, the identification of novel biomarkers to aid in the management of CRC is crucial. The aim of the present study was to identify candidate biomarkers for CRC, and to develop a better understanding of their role in tumourogenesis. METHODS: In this study, both plasma and tissue samples from patients diagnosed with CRC, together with non-malignant and normal controls were examined using mass spectrometry based proteomics and metabolomics approaches. RESULTS: It was established that the level of several biomolecules, including serotonin, gamma enolase, pyruvate kinase and members of the 14-3-3 family of proteins, showed statistically significant changes when comparing malignant versus non-malignant patient samples, with a distinct pattern emerging mirroring cancer cell energy production. CONCLUSION: The diagnosis and management of CRC could be enhanced by the discovery and validation of new candidate biomarkers, as found in this study, aimed at facilitating early detection and/or patient stratification together with providing information on the complex behaviour of cancer cells.

Iron status in patients with pyruvate kinase deficiency: neonatal hyperferritinaemia associated with a novel frameshift deletion in the PKLR gene (p.Arg518fs), and low hepcidin to ferritin ratios.

Pyruvate kinase (PK) deficiency is an iron-loading anaemia characterized by chronic haemolysis, ineffective erythropoiesis and a requirement for blood transfusion in most cases. We studied 11 patients from 10 unrelated families and found nine different disease-causing PKLR mutations. Two of these mutations - the point mutation c.878A>T (p.Asp293Val) and the frameshift deletion c.1553delG (p.(Arg518Leufs*12)) - have not been previously described in the literature. This frameshift deletion was associated with an unusually severe phenotype involving neonatal hyperferritinaemia that is not typical of PK deficiency. No disease-causing mutations in genes associated with haemochromatosis could be found. Inappropriately low levels of hepcidin with respect to iron loading were detected in all PK-deficient patients with increased ferritin, confirming the predominant effect of accelerated erythropoiesis on hepcidin production. Although the levels of a putative hepcidin suppressor, growth differentiation factor-15, were increased in PK-deficient patients, no negative correlation with hepcidin was found. This result indicates the existence of another as-yet unidentified erythroid regulator of hepcidin synthesis in PK deficiency.

Pyruvate kinase M2 is a novel diagnostic marker and predicts tumor progression in human biliary tract cancer.

BACKGROUND: The early diagnosis of biliary tract cancer (BTC) remains challenging, and there are few effective therapies. This study investigated whether the M2 isotype of pyruvate kinase (M2-PK), which serves as the key regulator of cellular energy metabolism in proliferating cells, could play a role in the diagnosis and therapy of BTC. METHODS: Plasma and bile M2-PK concentrations were measured by enzyme-linked immunosorbent assay in 88 patients with BTC, 79 with benign biliary diseases, and 17 healthy controls. M2-PK expression was assayed in a BTC tissue array by immunohistochemistry. The role of M2-PK in tumor growth, invasion, and angiogenesis was evaluated in BTC cell lines by retrovirus-mediated M2-PK transfection and short hairpin RNA silencing techniques. RESULTS: Sensitivity (90.3%) and specificity (84.3%) of bile M2-PK for malignancy were significantly higher than those for plasma M2-PK and serum carbohydrate antigen 19-9. M2-PK expression was specific for cancer cells and correlated with microvessel density. M2-PK positivity was a significant independent prognostic factor by multivariable analysis. Transfection of M2-PK in a negatively expressed cell line (HuCCT-1 cells) increased cell invasion, whereas silencing in an M2-PK-positive cell line (TFK cells) decreased tumor nodule formation and cellular invasion. A significant increase in endothelial tube formation was noted when supernatants from M2-PK-transfected cells were added to an in vitro angiogenesis assay, whereas supernatants from silenced cells negated endothelial tube formation. CONCLUSIONS: Bile M2-PK is a novel tumor marker for BTC and correlates with tumor aggressiveness and poor outcome. Short hairpin RNA-mediated inhibition of M2-PK indicates the potential of M2-PK as a therapeutic target.

Prognostic value of plasmatic tumor M2 pyruvate kinase and carcinoembryonic antigen in the survival of colorectal cancer patients.

Colorectal cancer (CRC) can be cured in most cases if diagnosed at an early stage. Carcinoembryonic antigen (CEA) remains the most widely used cancer marker for determining prognosis of CRC. Previous studies have shown that plasmatic tumor M2 pyruvate kinase (Tu M2-PK) is highly sensitive in CRC detection at an early stage and equally as good as the results for established tumor markers with clinical potential for cancer prognosis and monitoring. The aim of this study was to assess the prognostic value of Tu M2-PK in plasma using a survival analysis in combination with CEA in serum in patients newly diagnosed with CRC. The initial study included 183 patients who had a complete diagnostic colonoscopy. This cohort study was designed to evaluate the survival in patients with histologically confirmed gastrointestinal cancers (n = 41). Tu M2-PK concentrations in EDTA plasma were determined immunologically using an ELISA assay. Plasma Tu M2-PK levels were significantly higher in patients with distant metastases, stage IV for TNM score, and advanced stage (C+D) subgroups of Dukes than other subgroups. The univariate Cox's analysis showed that CEA and Tu M2-PK gave high hazard ratios for risk of death (odds ratio CEA = 3.57 and odds ratioTu M2-PK = 2.23) and comparable values in average survival time. The results for both biomarkers did not overlap. These findings suggest that plasmatic Tu M2-PK levels of more than 20 U/mL may be a predictor of death risk.