P-glycoprotein (P-gp) and glutathione S-transferase π (GST-π) are not only drug-resistance markers, but also prognostic markers of various cancers. The aim of the present study was to investigate the clinical significance of P-gp and GST-π in gallbladder carcinoma (GBC). Tissue samples from 42 patients with GBC were immunostained. Demographic, clinical and follow-up data were collected and analyzed. The positive expression rates of P-gp and GST-π in the GBC tissues were significantly higher (76.2 and 64.3%, respectively) than that of chronic cholecystitis specimens (30 and 20%, respectively) (P=0.014 and 0.035, respectively), and correlated with the Nevin stage of GBC. Multivariate analysis demonstrated that patients with positive expression of P-gp and GST-π showed a significantly lower 2-year survival rate (11.1 and 12%, respectively) compared with patients with negative expression (55.6 and 45.5%, respectively) (P=0.013 and 0.036, respectively). P-gp was also found to be an independent prognostic marker of 2-year survival rate by logistic regression analysis (B=−2.76, P=0.061). Results of this study suggest that P-gp is a prognostic marker of GBC and the detection of P-gp and GST-π may contribute to the prognosis of GBC and the application of chemotherapy as a therapeutic treatment.
gallbladder cancer; P-glycoprotein; glutathione S-transferase; metastasis; prognosis
Taxol is one of the most effective chemotherapeutic agents for the treatment of patients with breast cancer. Despite impressive clinical responses initially, the majority of patients eventually develop resistance to Taxol. Lactate dehydrogenase-A (LDH-A) is one of the predominant isoforms of LDH expressed in breast tissue, which controls the conversion of pyruvate to lactate and plays an important role in glucose metabolism. In this study we investigated the role of LDH-A in mediating Taxol resistance in human breast cancer cells.
Taxol-resistant subclones, derived from the cancer cell line MDA-MB-435, sustained continuous growth in high concentrations of Taxol while the Taxol-sensitive cells could not. The increased expression and activity of LDH-A were detected in Taxol-resistant cells when compared with their parental cells. The downregulation of LDH-A by siRNA significantly increased the sensitivity of Taxol-resistant cells to Taxol. A higher sensitivity to the specific LDH inhibitor, oxamate, was found in the Taxol-resistant cells. Furthermore, treating cells with the combination of Taxol and oxamate showed a synergistical inhibitory effect on Taxol-resistant breast cancer cells by promoting apoptosis in these cells.
LDH-A plays an important role in Taxol resistance and inhibition of LDH-A re-sensitizes Taxol-resistant cells to Taxol. This supports that Warburg effect is a property of Taxol resistant cancer cells and may play an important role in the development of Taxol resistance. To our knowledge, this is the first report showing that the increased expression of LDH-A plays an important role in Taxol resistance of human breast cancer cells. This study provides valuable information for the future development and use of targeted therapies, such as oxamate, for the treatment of patients with Taxol-resistant breast cancer.
The prognosis of gallbladder cancer (GBC) remains poor despite recent advances in diagnostics and therapeutic strategies. Although the role of microRNAs (miRs) in GBC have not been well documented, miR-155 is known to be associated with inflammation-associated carcinogenesis in various types of cancers. The aim of this study was to investigate the clinical significance of miR-155 expression and the biological functions of miR-155 in GBC. The expression levels of miR-155 in surgically resected GBCs and gallbladders with pancreaticobiliary maljunction (PBM) were assessed by quantitative reverse transcription-polymerase chain reaction. The relationship between the expression levels of miR-155 and clinicopathological features of GBCs was analyzed. Human GBC cell lines were transfected with miR-155 inhibitors or mimics, and the effects on proliferation and invasion were assessed. miR-155 was significantly overexpressed in GBCs when compared with that in gallbladders with PBM (P=0.007) and normal gallbladders (P=0.04). The high expression level of miR-155 in GBCs was significantly associated with the presence of lymph node metastasis (P=0.01) and a poor prognosis (P=0.02). In vitro assays showed that aberrant expression of miR-155 significantly enhanced GBC cell proliferation and invasion. In conclusion, high miR-155 expression correlates with the aggressive behavior of GBCs, and miR-155 may become a prognostic marker and therapeutic target for GBC.
gallbladder cancer; pancreaticobiliary maljunction; microRNA-155
Many cancer cells display the Warburg effect, that is, enhanced glycolysis followed by fermentation (conversion of pyruvate to lactate). Recently, the molecular basis for these effects has started to be elucidated, and the up-regulation of the lactate dehydrogenase A (LDH-A) isoform of lactate dehydrogenase is felt to be a major molecular mediator of this phenomenon. Moreover, LDH-A expression in tumor tissue and LDH-A levels in blood portend a bad prognosis, and LDH-A blockade can lead to tumor growth inhibition in tumor transplant models. We have extended existing data (some of which were published during the time when we were carrying out our studies) in two important ways: 1) inhibition of LDH-A in a glycolytic lung cancer cell line results in reactive oxygen species-mediated apoptosis and increased sensitivity to the chemotherapeutic drug paclitaxel and 2) inhibition of fermentative glycolysis can also be accomplished by activation of the pyruvate dehydrogenase complex by the drug dichloroacetate, now undergoing clinical trials, and that this phenomenon can be monitored in vivo in a noninvasive real-time manner through magnetic resonance spectroscopy using hyperpolarized pyruvate. Collectively, these data suggest that in vivo effects of drugs that redirect the fate of pyruvate, and hence are aimed at reversing the Warburg effect, could be monitored through the use of hyperpolarized magnetic resonance spectroscopy, a method that is scalable to human use.
With the help of my colleagues, I have been conducting epidemiological studies on biliary tract cancer (BTC), including gallbladder cancer (GBC) and extrahepatic bile duct cancer (BDC), in Japan and Chile for about 19 years. Clustered areas with high mortality rates, especially for female GBC were found to correspond with places or prefectures in Japan that were famous for rice production. The roles of known risk factors, such as gallstones and cholecystitis, were examined, but no single factor was implicated in the high mortality rates for GBC in these areas. A working hypothesis, called the “rice production hypothesis” was formulated; this initial hypothesis was replaced by a new multifactorial causation hypothesis: GBC is more likely to occur in individuals with a genetic susceptibility and a past history of gallstones or cholecystitis who are exposed to geographically specific environmental factors, such as agricultural chemicals. On the basis of various analytical studies, it is concluded that a certain agricultural chemical was responsible for the occurrence of GBC. At the time of writing, no evidence has been obtained to disprove our hypothesis. We have also conducted international collaborative studies in Chile, which has the highest mortality rate for GBC in the world. Bile from Chileans was found to have a higher mutagenic activity than that from Japanese subjects; Chileans with a history of constipation or a habit of consuming red chilli pepper had a high risk of developing GBC, if they also had gallstone(s). The presence of a regional difference in p53 mutagenesis was also observed.
epidemiology; biliary tract cancer; gallbladder cancer; bile duct cancer; Japan; Chile
The inactivation of the tumor suppressor gene and activation of the proto-oncogene are key steps in the development of human cancer. p53 and beta-catenin are examples of such genes, respectively. In the present study, our aim was to determine the role of these genes in the carcinogenesis of the gallbladder by immunohistochemistry.
Patients and Methods:
Sections from paraffin-embedded blocks of surgically resected specimens of gallbladder cancer (GBC) (80 cases), chronic cholecystitis (60 cases), and control gallbladders (10 cases) were stained with the monoclonal antibody p53, and polyclonal antibody beta-catenin. Results were scored semiquantitatively and statistical analysis performed. p53 expression was scored as percentage of the nuclei stained. Beta-catenin expression was scored as type of expression–membranous, cytoplasmic, and nuclear staining. Beta-catenin expression was correlated with tumor invasiveness, differentiation, and stage.
Over-expression of p53 was seen in 56.25% of GBC cases and was not seen in chronic cholecystitis or in control gallbladders. p53 expression in gallbladder cancer was significantly higher than in inflammatory or control gallbladders (P < 0.0001). p53 expression increased with increasing tumor grade (P = 0.039). Beta-catenin nuclear expression was seen in 75% cases of gallbladder cancer and in no case of chronic cholecystitis and control gallbladder. Beta-catenin nuclear expression increased with tumor depth invasiveness, and grade (P = 0.028 and P = 0.0152, respectively).
p53 and beta-catenin nuclear expression is significantly higher in GBC. p53 expression correlates with increasing tumor grade while beta-catenin nuclear expression correlates with tumor grade and depth of invasion, thus suggesting a role for these genes in tumor progression of GBC.
Beta-catenin; gallbladder cancer; p53; tumor invasiveness
Gallbladder cancer (GBC) is a relatively uncommon carcinoma among gastrointestinal cancers and usually has a rather poor prognosis. The most common subtype of GBC is adenocarcinoma (AC), which accounts for about 90% of GBC. Squamous carcinoma/adenosquamous carcinoma (SC/ASC) are comparatively rare histopathological subtypes of GBC. The clinicopathological features and biological behaviors of SC/ASC have not been well-characterized. No molecular biomarkers are currently available for predicting the progression, metastasis, and prognosis of the SC/ASC subtype of GBC.
We examined the expression levels of CCT2 and PDIA3 by immunohistochemistry (IHC) staining in human GBC tissue samples collected from 46 patients with SC/ASC and evaluated the clinicopathological significance of both CCT2 and PDIA3 expression in the SC/ASC subtypes of GBC by Kaplan-Meier analysis and multivariate Cox regression analysis. For comparison, we included specimens from 80 AC patients in our study to investigate the specificity of CCT2 and PDIA3 expression in GBC subtypes.
We found that the positive expression of CCT2 and PDIA3 was significantly associated with clinicopathological features of both SC/ASC and AC specimens, including high TNM stage and lymph node metastasis. Univariate analysis revealed that the two-year survival rate was significantly lower for patients with positive expression of CCT2 and PDIA3 than for those with negative expression. Multivariate analysis also indicated that the positive expression of CCT2 and PDIA3 was negatively correlated with poor postoperative patient survival and positively correlated with high mortality.
Our study suggests that positive expression of CCT2 or PDIA3 is associated with tumor progression and the clinical behavior of gallbladder carcinoma. Therefore, CCT2 and PDIA3 could be potentially important diagnostic and prognostic biomarkers for both SC/ASC and AC subtypes of GBC.
gallbladder cancer; adenocarcinoma; squamous cell carcinoma; adenosquamous carcinoma; CCT2; PDIA3
Lactate dehydrogenase (LDH) isoenzyme distribution was examined in 106 urine samples being tested cytologically for evidence of bladder cancer; the samples were selected to have less than 20 leucocytes and erythrocytes per high power field and the LDH pattern determined by electrophoresis. The Papanicolaou stained-smears showed 68 negative, 17 suspicious and 21 positive. The LDH M-fraction of the urinary supernatant in cytologically positive cases was significantly greater than in negative cases, although the latter included a few false negative samples. Some of the false negatives gave positive results for the LDH M-fraction; these results suggest that the determination of LDH isoenzymes in the urine is useful in diagnosing urinary tract cancers, including early stage, and for follow-up of patients with bladder cancers after surgical resection.
Gallbladder carcinoma (GBC) is a lethal neoplasm, and new prognostic markers are required. Deregulation of E3 ligases contributes to cancer development and is associated with poor prognosis. Carboxyl terminus of heat shock protein 70-interacting protein (CHIP) is a U-box-type E3 ubiquitin ligase, the role of which has not been evaluated in GBC. Therefore, the present study investigated CHIP expression in GBC and its prognostic significance. In the present study, CHIP expression was measured in 78 tumor specimens of GBC by immunohistochemistry and the correlation between CHIP expression and clinicopathological factors was analyzed. Of the tumor specimens, 26.9% showed high staining intensity [the CHIP high expression group (HEG)]. The CHIP-HEG was not associated with other common clinicopathological parameters, including T stage, and lymph node and distant metastases. CHIP-HEG patients had a significantly worse prognosis than patients with low CHIP expression with median cancer-specific survival times of 8.0 months (range, 1–34 months) and 13.0 months (range, 1–110 months), respectively (P=0.023). Multivariate analyses showed that CHIP expression was close to being an independent risk factor for predicting patient survival. CHIP expression may be associated with a poor prognosis in GBC. Since CHIP is not associated with other clinicopathological prognostic factors, it may serve as an ideal molecular marker for predicting patient outcomes.
carboxyl terminus of Hsp70-interacting protein; gallbladder carcinoma; prognosis; survival
Although most patients with severe acute hepatitis are conservatively cured, some progress to acute liver failure (ALF) with a high rate of mortality. Based on the evidence that over-activation of macrophages, followed by disturbance of the hepatic microcirculation, plays a key role in ALF, we hypothesized that the production of serum lactate dehydrogenase (LDH) might increase in the liver under hypoxic conditions and could be an indicator to discriminate between conservative survivors and fatal patients at an early stage.
To confirm this hypothesis, we developed a new parameter with serum alanine aminotransferase (ALT) and LDH: the ALT-LDH index = serum ALT/(serum LDH - median of normal LDH range). We analyzed retrospectively 33 patients suffering acute liver injury (serum ALT more than 1000 U/L or prothrombin time expressed as international normalized ratio over 1.5 at admission) and evaluated the prognostic value of the ALT-LDH index, comparing data from the first 5 days of hospitalization with the Model for End-Stage Liver Disease (MELD) score. Patients whose symptoms had appeared more than 10 days before admission were excluded from this study. Among those included, 17 were conservative survivors, 9 underwent liver transplantation (LT) and 7 died waiting for LT. We found a rapid increase in the ALT-LDH index in conservative survivors but not in fatal patients. While the prognostic sensitivity and specificity of the ALT-LDH index was low on admission, at day 3 they were superior to the results of MELD.
ALT-LDH index was useful to predict the prognosis of the patients with acute liver injury and should be helpful to begin preparation for LT soon after admission.
The recent development of hyperpolarized 13C magnetic resonance spectroscopic imaging (MRSI) provides a novel method for in-vivo metabolic imaging with potential applications for detection of cancer and response to treatment. Chemotherapy-induced apoptosis was shown to decrease the flux of hyperpolarized 13C-label from pyruvate to lactate due to depletion of NADH, the coenzyme of lactate dehydrogenase (LDH). In contrast, we show here that in PC-3MM2 tumors, inhibition of platelet-derived growth factor receptor with imatinib reduces the conversion of hyperpolarized pyruvate to lactate by lowering the expression of LDH itself. This was accompanied by reduced expression of vascular endothelial growth factor and glutaminase, and is likely mediated by reduced expression of their transcriptional factors hypoxia-inducible factor-1 and c-Myc. Our results indicate that hyperpolarized 13C MRSI could potentially detect the molecular effect of various cell-signaling inhibitors, thus providing a radiation-free method to predict tumor response.
Hyperpolarized 13C MRS; Tumor metabolism; PDGFR signaling; HIF-1; cMyc
The poor overall prognosis of Gallbladder carcinoma (GBC) patients and the limited therapeutic regimens for these patients demonstrates the need for better therapeutic modalities, while the growing evidences have indicated that those genes contributed to epigenetic regulation may serve as therapeutic targets. The function of histone acetylation on growth and survival of GBC cells remains unknown. In present study, an RNAi screening of 16 genes involving histone acetyltransferases (HATs) was applied to GBC-SD cells and we found that KAT5 knockdown specifically inhibits the proliferation of GBC-SD cells by casp9-mediated apoptosis. Microarray data analysis showed that KAT5 RNAi may result in cleaved casp9 upregulation through p38MAPK activation in GBC-SD cells. The mRNA expression level of KAT5 was significantly upregulated in GBC tissues than in the adjacent normal tissues. In consistence with the mRNA level, the protein expression of KAT5 was markedly increased in tissues from patients with poor prognosis than those with good prognosis. These findings strongly indicated that KAT5 was implicated in GBC tumorigenesis and that its expression level was associated with the prognosis. Our work may also provide a potential therapeutic target for treatment of GBC patients.
Gallbladder carcinoma; histone acetyltransferases; RNAi screening; KAT5; p38MAPK
The antioxidant and hepatoprotective properties of tofu using acetaminophen to induce liver damage in albino rats were evaluated. Tofus were prepared using calcium chloride, alum, and steep water as coagulants. The polyphenols of tofu were extracted and their antioxidant properties were determined. The weight gain and feed intake of the rats were measured. The analysis of serum alanine aminotransferase (ALT), alkaline phosphatase (ALP), aspartate aminotransferase (AST), and lactate dehydrogenase (LDH) activities and the concentrations of albumin, total protein, cholesterol, and bilirubin were analyzed. The result reveals that the antioxidant property of both soluble and bound polyphenolic extracts was significantly higher in all tofus, but the steep water coagulated tofu was recorded higher. Rats fed with various tofus and acetaminophen had their serum ALP, ALT, AST, and LDH activities; total cholesterol; and bilirubin levels significantly (P < 0.05) reduced, and total protein and albumin concentrations increased when compared with basal diet and acetaminophen administered group. Therefore, all tofus curdled with various coagulants could be used to prevent liver damage caused by oxidative stress.
Clinical significance of sex hormone receptors in gallbladder cancer is not yet established. This study was performed to assess the expression pattern of estrogen and progesterone receptors in benign and malignant gallbladder lesions, and to assess their clinicopathological significance.
Tissue samples from resected gallbladder for cholelithiasis (n = 20) and carcinoma gallbladder (n = 25) were evaluated for estrogen and progesterone receptor (ER, PR) expression by automated immunohistochemistry. Their expression was correlated with different clinicopathological parameters.
ER expression was significantly high (28%, 95% confidence interval [CI], 14–47) in gallbladder cancer than in chronic cholecystitis (0%; P = .012). PR expression did not differ in two groups (benign 40%, 95% CI, 21.8–61.4; malignant 52%, 95% CI, 33.5–69.9). Metaplastic benign lesions had near significant higher expression of PR (71.4%) than nonmetaplastic lesion (15.9%; P = .062). Their expression did not correlate with gender, age, menopausal status, presence of gallstones, tumor differentiation, and tumor stage.
Female sex hormones play an important role in the gallbladder carcinogenesis. ER and PR may not have prognostic value. Presence of ER in ∼1/3 and PR in 1/2 of patients with carcinoma gallbladder suggests the potential role of antihormonal therapy.
The Warburg effect describes an increase in aerobic glycolysis and enhanced lactate production in cancer cells. Lactate dehydrogenase A (LDH-A) regulates the last step of glycolysis that generates lactate and permits the regeneration of NAD+. LDH-A gene expression is believed to be upregulated by both HIF and Myc in cancer cells to achieve increased lactate production. However, how oncogenic signals activate LDH-A to regulate cancer cell metabolism remains unclear. We found that the oncogenic receptor tyrosine kinase FGFR1 directly phosphorylates LDH-A. Phosphorylation at Y10 and Y83 enhances LDH-A activity by enhancing the formation of active, tetrameric LDH-A and the binding of LDH-A substrate NADH, respectively. Moreover, Y10 phosphorylation of LDH-A is common in diverse human cancer cells, which correlates with activation of multiple oncogenic tyrosine kinases. Interestingly, cancer cells with stable knockdown of endogenous LDH-A and rescue expression of a catalytic hypomorph LDH-A mutant, Y10F, demonstrate increased respiration through mitochondrial complex I to sustain glycolysis by providing NAD+. However, such a compensatory increase in mitochondrial respiration in Y10F cells is insufficient to fully sustain glycolysis. Y10 rescue cells show decreased cell proliferation and ATP levels under hypoxia and reduced tumor growth in xenograft nude mice. Our findings suggest that tyrosine phosphorylation enhances LDH-A enzyme activity to promote the Warburg effect and tumor growth by regulating the NADH/NAD+ redox homeostasis, representing an acute molecular mechanism underlying the enhanced lactate production in cancer cells.
To diagnose and explore the serological diagnostic factors for liver metastasis in patients with breast cancer before symptoms occur.
A total of 430 female in-patients with breast cancer of stages 0 to IIIC who came to Tianjin Medical University Cancer Institute and Hospital from January 2003 to January 2004 were studied and followed up until May 2011. Serum levels of biochemical markers for tumor and liver were measured at the time of diagnosis.
Liver metastasis was more likely to occur in patients with stage III cancer or c-erbB-2-positive expression. Alanine aminotransferase, aspartate aminotransferase, γ-glutamyltransferase (GGT), alkaline phosphatase, lactate dehydrogenase (LDH), and carbohydrate antigen 153 (CA153) levels were significantly higher in patients with liver metastasis than those without liver metastasis. Diagnostic indices of LDH, GGT, and CA153 were 174 U/L, 32 U/L, and 26.48 µg/L, respectively. The areas under the curves of LDH, GGT, and CEA were 0.795, 0.784, and 0.661, respectively, and sensitivities of parallel tests for LDH and CA153 and for GGT and CA153 were 88.6% and 85.7%, respectively. The specificity of serial tests for both pairs of enzymes was 97.7%.
The sensitivity and specificity of combined tumor and biochemical markers could be used as indicators during screening for breast-liver metastasis.
breast neoplasms; liver; neoplasm metastasis; oxidoreductases; gamma-glutamyltransferase
Background. Gallbladder cancers (GBCs) are highly aggressive cancers with high mortality. However, biological markers for the progression and prognosis of GBC are currently unavailable in the clinic. Objective. To identify biomarkers for predicting GBC metastasis and prognosis. Methods. We examined ALDH1A3 and GPX3 expressions in 46 squamous cell/adenosquamous carcinomas (SC/ASC) and 80 adenocarcinomas (AC) by using immunohistochemistry. Results. Positive ALDH1A3 and negative GPX3 expressions were significantly associated with lymph node metastasis and invasion of SC/ASCs and ACs. Univariate Kaplan-Meier analysis showed that either positive ALDH1A3 (P < 0.001) or negative GPX3 (P < 0.001) expression significantly correlated with decreased overall survival in both SC/ASC and AC patients. Multivariate Cox regression analysis showed that positive ALDH1A3 expression or negative GPX3 expression was an independent poor-prognostic predictor in both SC/ASC and AC patients. Conclusions. Our study suggested that positive ALDH1A3 and negative GPX3 expressions are closely associated with clinical pathological behaviors and poor prognosis of gallbladder cancer.
Clinical decision making is based on results from qualitative and quantitative information. To provide quantitative data, various laboratory variables are widely used in the clinical evaluation of patients with small-cell lung cancer (SCLC). The tumour marker serum neuron-specific enolase (S-NSE) and the routine laboratory parameter serum lactate dehydrogenase (S-LDH) have been investigated, mostly separately. Few studies have compared their importance in SCLC, especially in progressive disease (PD). The present investigation was undertaken to evaluate S-NSE for diagnostic efficacy in PD and compare it with S-LDH. In 27 patients in a treatment trial of SCLC, regular follow-up laboratory values were prospectively obtained. Chemotherapy was given according to trial protocols, and all clinical evaluation followed the WHO recommendations. At re-evaluation all but three values had normalised (two S-NSE, one S-LDH). S-NSE at progression was increased in 93% of the patients and S-LDH in 59%. The efficacy of S-NSE to discriminate between response and PD was superior to S-LDH (0.92 vs 0.70). There was no additive effect of the two parameters in prediction of PD, and the discriminating power was higher for S-NSE than for S-LDH (P < 0.0008). The disease status-related marker increments in relation to upper reference limits, i.e. the signal-noise relation, were higher for S-NSE than for S-LD. Both of the markers carry information on PD. S-NSE is, however, clearly superior to S-LDH in reflecting disease status during therapy. This prompts us to conclude that S-NSE should replace S-LDH as prognostic factor and disease activity monitor in SCLC.
Background: Application of follicular fluid (FF) and platelet-activating factor (PAF) in artificial insemination improves sperm motility. Lactate dehydrogenase C (LDH-C) is a key enzyme for sperm motility. In this study, the effects of FF and PAF on the sperm motility index and LDH-C expression were investigated. Moreover, LDH-C expression was compared between asthenozoospermic and normozoospermic samples.
Methods: The expression of LDH-C was examined by quantitative real-time polymerase chain reaction (q-RT PCR) and western blotting after it was treated with optimized concentrations of FF and PAF in twenty asthenozoospermic samples. Also, LDH-C expression was evaluated in five normozoospermic samples.
Results: Samples with 75% FF and 100 nM of PAF had an increase in their percentages of progressive and slowly motile sperms and a decrease in their percentages of non-progressive and non-motile sperms. Moreover, LDH-C mRNA transcripts were not changed following PAF and FF treatment, and LDH-C protein was detected in highly progressive motile specimens treated with FF in the asthenozoospermic samples. Furthermore, LDH-C expression was more detectable in the normal sperms.
Conclusion: Our results indicated that PAF had more beneficial effects than FF on sperm motility in the asthenozoospermic samples (P=0.0001), although the LDH-C expressions of the sperms were not changed significantly in both groups. We found no association between LDH-C expression and sperm motility after FF and PAF actions. This finding, however, requires further investigation. The fact that LDH-C protein was detected in the normozoospermic, but not asthenozoospermic, samples could be cited as a reason for the infertility in these patients.
Follicular fluid; Platelet-activating factor; LDH-C; Sperm motility; Asthenozoospermia
Lactate dehydrogenase (LDH; E.C. 184.108.40.206) is a crucial enzyme involved in energy metabolism in muscle, facilitating the production of ATP via glycolysis during oxygen deprivation by recycling NAD+. The present study investigated purified LDH from the muscle of 20 h anoxic and normoxic T. s. elegans, and LDH from anoxic muscle showed a significantly lower (47%) Km for L-lactate and a higher Vmax value than the normoxic form. Several lines of evidence indicated that LDH was converted to a low phosphate form under anoxia: (a) stimulation of endogenously present protein phosphatases decreased the Km of L-lactate of control LDH to anoxic levels, whereas (b) stimulation of kinases increased the Km of L-lactate of anoxic LDH to normoxic levels, and (c) dot blot analysis shows significantly less serine (78%) and threonine (58%) phosphorylation in anoxic muscle LDH as compared to normoxic LDH. The physiological consequence of anoxia-induced LDH dephosphorylation appears to be an increase in LDH activity to promote the reduction of pyruvate in muscle tissue, converting the glycolytic end product to lactate to maintain a prolonged glycolytic flux under energy-stressed anoxic conditions.
Serum lactate dehydrogenase (LDH) is a prognostic factor for patients with stage IV melanoma. To gain insights into the biology underlying this prognostic factor, we analyzed total serum LDH, serum LDH isoenzymes, and serum lactate in up to 49 patients with metastatic melanoma. Our data demonstrate that high serum LDH is associated with a significant increase in LDH isoenzymes 3 and 4, and a decrease in LDH isoenzymes 1 and 2. Since LDH isoenzymes play a role in both glycolysis and oxidative phosphorylation (OXPHOS), we subsequently determined using tissue microarray (TMA) analysis that the levels of proteins associated with mitochondrial function, lactate metabolism, and regulators of glycolysis were all elevated in advanced melanomas compared with nevic melanocytes. To investigate whether in advanced melanoma, the glycolysis and OXPHOS pathways might be linked, we determined expression of the monocarboxylate transporters (MCT) 1 and 4. Analysis of a nevus-to-melanoma progression TMA revealed that MCT4, and to a lesser extend MCT1, were elevated with progression to advanced melanoma. Further analysis of human melanoma specimens using the Seahorse XF24 extracellular flux analyzer indicated that metastatic melanoma tumors derived a large fraction of energy from OXPHOS. Taken together, these findings suggest that in stage IV melanomas with normal serum LDH, glycolysis and OXPHOS may provide metabolic symbiosis within the same tumor, whereas in stage IV melanomas with high serum LDH glycolysis is the principle source of energy.
Melanoma; Lactate dehydrogenase; Glycolysis; Mitochondria; Oxidative phosphorylation; Monocarboxylate transporters
Neurotrophic factors such as brain derived neurotrophic factor (BDNF) are synthesized in a variety of neural and non-neuronal cell types and regulate survival, proliferation and apoptosis. In addition, bone morphogenetic proteins (BMPs) inhibit the proliferation of pulmonary large carcinoma cells bone morphogenetic protein receptor, type IA (BMPR1A). Little is known about the expression of BDNF or BMPR1A in malignant gall bladder lesions. This study was to evaluate BDNF and BMPR1A expression and evaluate the clinicopathological significance in benign and malignant lesions of the gallbladder.
The BDNF and BMPR1A expression of gallbladder adenocarcinoma, peritumoral tissues, adenoma, polyp and chronic cholecystitis were Immunohistochemically determined.
BDNF expression was significantly higher in gallbladder adenocarcinoma than in peritumoral tissues, adenoma, polyps and chronic cholecystitis samples. However, BMPR1A expression was significantly lower in gallbladder adenocarcinoma than in peritumoral tissues, adenomas, polyps and chronic cholecystitis tissues. The specimens with increased expression of BDNF in the benign lesions exhibited moderate- or severe-dysplasia of gallbladder epithelium. BDNF expression was significantly lower in well-differentiated adenocarcinomas with maximum tumor diameter <2 cm, no metastasis to lymph nodes, and no invasion of regional tissues compared to poorly-differentiated adenocarcinomas with maximal tumor diameter >2 cm, metastasis of lymph node, and invasiveness of regional tissues in gallbladder adenocarcinoma. BMPR1A expression were significantly higher in the well-differentiated adenocarcinoma with maximal tumor diameter <2 cm, no metastasis of lymph node, and no invasion of regional tissues compared to poorly-differentiated adenocarcinomas with maximal tumor diameter >2 cm, metastasis of lymph node, and invasiveness of regional tissues in gallbladder. Univariate Kaplan-Meier analysis indicated increased expression of BDNF or decreased expression of BMPR1A was associated with decreased disease specific survival (DSS) rates. Similarly, multivariate Cox regression analysis showed increased expression of BDNF or decreased expression of BMPR1A are independent predictors of poor DSS rates in gallbladder adenocarcinoma.
In gallbladder malignancies, the increased expression of BDNF and decreased expression of BMPR1A were associated with increased risk of metastasis, regional invasion and mortality. They might serve as novel indicators of gallbladder adenocarcinoma outcomes, which may prove valuable for the development of personalized therapeutic paradigms.
Gallbladder lesions; BDNF; BMPR1A; Clinicopathology
As one of the five Lactate dehydrogenase (LDH) isoenzymes, LDH5 has the highest efficiency to catalyze pyruvate transformation to lactate. LDH5 overexpression in cancer cells induces an upregulated glycolytic metabolism and reduced dependence on the presence of oxygen. Here we analyzed LDH5 protein expression in a well characterized large cohort of primary lung cancers in correlation to clinico-pathological data and its possible impact on patient survival.
Primary lung cancers (n = 269) and non neoplastic lung tissue (n = 35) were tested for LDH5 expression by immunohistochemistry using a polyclonal LDH5 antibody (ab53010). The results of LDH5 expression were correlated to clinico-pathological data as well as to patient's survival. In addition, the results of the previously tested Transketolase like 1 protein (TKTL1) expression were correlated to LDH5 expression.
89.5% (n = 238) of NSCLC revealed LDH5 expression whereas LDH5 expression was not detected in non neoplastic lung tissues (n = 34) (p < 0.0001). LDH5 overexpression was associated with histological type (adenocarcinoma = 57%, squamous cell carcinoma = 45%, large cell carcinoma = 46%, p = 0.006). No significant correlation could be detected with regard to TNM-stage, grading or survival. A two sided correlation between the expression of TKTL1 and LDH5 could be shown (p = 0.002) within the overall cohort as well as for each grading and pN group. A significant correlation between LDH5 and TKTL1 within each histologic tumortype could not be revealed.
LDH5 is overexpressed in NSCLC and could hence serve as an additional marker for malignancy. Furthermore, LDH5 correlates positively with the prognostic marker TKTL1. Our results confirm a close link between the two metabolic enzymes and indicate an alteration in the glucose metabolism in the process of malignant transformation.
An analysis of prognostic factors in small cell lung cancer has been made using presentation data from 86 of 101 consecutive patients referred to The Finsen Institute for chemotherapy. Prognosis was in univariate analysis significantly correlated with performance status (PS), disease extent, serum lactate dehydrogenase (LDH), neuron specific enolase (NSE), alpha-1-acid glycoprotein and plasma sodium. Multivariate analysis, taking stage of disease into account, resulted in selection of PS and NSE as the most influential of the investigated variables. LDH was excluded as an independent prognosticator, but there was a strong correlation between the influence of LDH and NSE (coefficient: -0.38) as well as between their serum concentrations (coefficient: 0.72). LDH and NSE apparently have similar prognostic influence, and NSE seems superior to LDH. A firm conclusion should, however, await our investigation of a large series of patients.
Hypoxia and oncogene expression both stimulate glycolytic metabolism in tumors, thereby leading to lactate production. However, lactate is more than merely a by-product of glycolysis: it can be used as a metabolic fuel by oxidative cancer cells. This phenomenon resembles processes that have been described for skeletal muscle and brain that involve what are known as cell-cell and intracellular lactate shuttles. Two control points regulate lactate shuttles: the lactate dehydrogenase (LDH)-dependent conversion of lactate into pyruvate (and back), and the transport of lactate into and out of cells through specific monocarboxylate transporters (MCTs). In tumors, MCT4 is largely involved in hypoxia-driven lactate release, whereas the uptake of lactate into both tumor cells and tumor endothelial cells occurs via MCT1. Translating knowledge of lactate shuttles to the cancer field offers new perspectives to therapeutically target the hypoxic tumor microenvironment and to tackle tumor angiogenesis.