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Background

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.

Results

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.

Conclusion

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.

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.

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.

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.

Background

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.

Results

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.

Conclusion

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.

ABSTRACT

BACKGROUND:

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.

METHODS:

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.

RESULTS:

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.

CONCLUSION:

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.

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.

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.

Aims

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.

Methods

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.

Results

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.

Conclusions

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.

Rats were used to study the general activity and the isoenzyme spectrum of lactate dehydrogenase (LDH) during single-instance and long-term introduction of polychlorocamphene. Total lactate dehydrogenase activity decreases in the liver during the single-instance introduction of half the LD50 (120 mg/kg). The isoenzyme spectrum of LDH is characterized by an increase in the quantity of LDH1, LDH2, and LDH3 and by a decrease in the amount of LDH4. The overall LDH activity does not change in blood serum. The isoform ratio changes insignificantly and LDH1 falls, but normalized 15 days after the introduction of the compound. Long-term introduction of polychlorocamphene at levels 1/100 the LD50 dose over 1.3 and 6 months causes a reduction in the overall LDH activity, both in the liver and in the serum. A decrease in the activity of the basic LDH isoenzyme of the liver (LDH5) and a sharp increase in LDH3 are characteristic for the isoenzyme spectrum of the liver. LDH1 and LDH4 decrease and LDH2 and LDH3 increase in blood serum. Beginning with the third month of polychlorocamphene introduction, LDH1 tends to return to normal levels. LDH2, LDH3, and LDH4 do return to normal levels, while LDH5 increases regularly. This results in a reduction of the number of H subunits and an increase of M subunits. This is characteristic of hypoxic states. On comparing the changes in the LDH enzymes of the liver and blood serum, it can be considered that the introduction of polychlorocamphene does not result in an increase in the permeability of the cellular membranes of the liver for LDH isoenzymes, while the observed isoenzyme spectrum shifts in blood serum are either the result of the biosynthesis of the isoforms of this enzyme changed by the compound or the result of the permeability for them of cells of other tissues.

Activities for nicotinamide adenine dinucleotide (NAD)-dependent and NAD-independent forms of lactate dehydrogenase (LDH) were measured in cell-free extracts of Staphylococcus aureus strain PS 6 for the d and l isomers of lactate. Data obtained for the NAD-dependent lactate dehydrogenases indicate that oxidation of both isomers of lactate is due to both an l-lactate-specific LDH and a lactate racemase. After acrylamide gel electrophoresis, two bands exhibiting LDH activity were detected in crude or in partially purified cell-free extracts. The fast band exhibited LDH activity that was not NAD-dependent for both isomers of lactate, whereas, the slow band had very high NAD-dependent LDH activity for the l isomer but just detectable activity or the d isomer. Both bands appeared when d-lactate was used as the substrate, but only the slow band was formed when l-lactate was the substrate. NAD-dependent LDH, in apparent association with a nonspecific tetrazolium-reducing protein, is responsible for the production of the slow band.

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There are five lactate dehydrogenase (LDH) isoenzymes, composed of various combinations of two types of subunits. LDH-5, which contains only the LDH A subunit, is known to be present in both the cytoplasm and the nucleus, to act as a single-stranded DNA-binding protein possibly functioning in transcription and/or replication, and to undergo phosphorylation of tyrosine 238 in approximately 1% of the enzyme after cell transformation by certain tumor viruses. We have characterized LDH from wild-type PC12 pheochromocytoma cells and from a PC12 variant (MPT1) that exhibits altered lactate metabolism and altered expression of multiple genes. Wild-type and MPT1 cells contain different proportions of LDH isoenzymes, with LDH-5 being more predominant in wild-type cells than in the variant. A small fraction of LDH from PC12 cells contains phosphotyrosine. Approximately 99% of the total LDH activity is located in the cytoplasm, but all of the phosphotyrosine-containing LDH is located in the nucleus. Furthermore, essentially all of the nuclear LDH contains phosphotyrosine. These results suggest that tyrosine phosphorylation can affect its role in the nucleus.

Images

OBJECTIVE: Lactate dehydrogenase (LDH), a tetrameric protein composed of four monomers, is expressed as five isoenzymes. Serum LDH isoenzymes may be useful in differential diagnosis of ascites etiology since tissue damage releases isoenzymes contained therein, leading to a change in their pattern. MATERIALS AND METHODS: We determined ascitic fluid LDH level and LDH isoenzyme activities in patients with malignant and nonmalignant ascites in a total of 76 patients (43 males and 33 females). RESULTS: LDH level, LDH-4 activity and LDH-5 activity were found to be significantly higher, and LDH-1 activity was found to be lower in malignant ascites when compared with nonmalignant ascites. LDH-1 activity was detected to be significantly higher in the sterile cirrhotic ascites when compared with spontaneous bacterial peritonitis, malignant ascites, tuberculous ascites and congestive heart failure-related ascites. LDH-2 activity was found to be higher in spontaneous bacterial peritonitis when compared with the other groups. LDH-3 activity was detected to be higher in spontaneous bacterial peritonitis, malignant ascites and tuberculous ascites when compared with the sterile cirrhotic ascites. In the diagnosis of malignant ascites, the sensitivity and specificity were 96% and 76% for LDH level, 90% and 70% for LDH-1 activity, 94% and 62% for LDH-4 activity, and 100% and 56% for LDH-5 activity, respectively. CONCLUSION: Ascitic LDH and its isoenzyme pattern may be helpful for the differential diagnosis of the most common causes of ascites: cirrhosis, spontaneous bacterial peritonitis, congestive heart failure, tuberculosis and malignancy.

A nitric oxide-inducible lactate dehydrogenase from S. aureus, Sa-LDH-1, has been cloned, expressed, purified and crystallized in space group C2, with unit-cell parameters a = 131.4, b = 74.4, c = 103.2 Å, β = 133.4°.

Recent studies have indicated that Staphylococcus aureus can survive the nitrosative stress (caused by the radical nitric oxide; NO·) mounted by the immune system of the infected host. It does this by expressing a nitric oxide-inducible l-lactate dehydrogenase (Sa-LDH-1). Therefore, if efficient inhibitors of Sa-LDH-1 can be designed then Sa-LDH-1 could be a potential drug target against the pathogen S. aureus. For this purpose, the nitric acid-inducible LDH-1 from S. aureus COL strain has been cloned into the expression vector pET-28a(+) and the protein has been expressed, purified and crystallized. The Sa-­LDH-1 crystal diffracted to 2.4 Å resolution at a home X-ray source and belonged to space group C2, with unit-cell parameters a = 131.4, b = 74.4, c = 103.2 Å, β = 133.4°.

Background

Various Pseudomonas strains can use l-lactate as their sole carbon source for growth. However, the l-lactate-utilizing enzymes in Pseudomonas have never been identified and further studied.

Methodology/Principal Findings

An NAD-independent l-lactate dehydrogenase (l-iLDH) was purified from the membrane fraction of Pseudomonas stutzeri SDM. The enzyme catalyzes the oxidation of l-lactate to pyruvate by using FMN as cofactor. After cloning its encoding gene (lldD), l-iLDH was successfully expressed, purified from a recombinant Escherichia coli strain, and characterized. An lldD mutant of P. stutzeri SDM was constructed by gene knockout technology. This mutant was unable to grow on l-lactate, but retained the ability to grow on pyruvate.

Conclusions/Significance

It is proposed that l-iLDH plays an indispensable function in Pseudomonas l-lactate utilization by catalyzing the conversion of l-lactate into pyruvate.

Background

Only 50% of gallbladder cancers (GBC) are recognized before operation and the remaining tumors are diagnosed during surgery or afterwards by the pathologist. These situations may demand substantial modifications of the proceeding during surgery as well as the need for reoperation in some cases. Therefore, the time of diagnosis may strongly influence the surgical management of GBC and the prognosis of the patients.

Methods

Records and follow-up of 152 patients with gallbladder carcinoma who underwent surgery between 1980 and 2004 were examined according to the time of diagnosis, TNM staging system, surgical procedures, morbidity and predictors of survival. There were 76 patients with preoperative diagnosis of GBC (50%; group1), 44 patients with intraoperative diagnosis (29%; group 2) and 32 patients (21%; group 3) with postoperatively incidental finding of GBC. In all cases radical resection of the GBC was intended, except in 5 patients from group 1. Surgical procedures comprised from simple cholecystectomy to multivisceral resections.

Results

Overall 5-year survival rate was 7% with a significantly better median survival in group 3 (53.2 month), when compared to only 6.1 month (group 2) and 5.4 month (group 1), respectively. Findings at operation forced significant modifications of the surgical strategy in 85%. Complete resection of GBC was achieved in 38% of the patients. Stage- dependent survival was comparable between the groups following R0 resection. Tumor stage, in particular the nodal status and radicality of the procedure, but not the time of diagnosis were the most powerful predictors of outcome.

Conclusions

Complete tumor resection may provide long-term survival even in locally advanced GBC. Although the time of diagnosis of GBC causes significant changes of the intended procedures during and after surgery, it has no influence on the prognosis provided that radical (R0) resection was accomplished.

The influence of pretreatment serum neuron-specific enolase (S-NSE) in addition to more conventional prognostic factors on survival duration in small-cell lung cancer (SCLC) was investigated in 770 patients from nine centres in six countries. The other variables included stage of disease, performance status (PS), age, sex, serum lactate dehydrogenase (S-LDH), serum alkaline phosphatase (S-AP), and serum carcinoembryonic antigen (S-CEA). Increased values of S-NSE (> 12.5 micrograms-1 l) were observed in 81% of the patients, whereas S-LDH, S-AP and S-CEA were elevated in only half of the patients or less. Multivariable analysis by Cox's proportional hazard model disclosed S-NSE as the most powerful prognostic factor followed by poor PS and extensive stage disease. If PS was ignored, S-LDH came up as a significant prognostic factor. S-AP, S-CEA, age and sex had no significant influence on the prognosis. The three prognostic factors, S-NSE, PS and stage of disease, enabled establishment of a prognostic index (PI) based on a simple algorithm PI = zNSE + z(stage) + 2zPS. This segregated the patients into four groups with clearly different prognosis. The median survival and 95% confidence intervals of the four groups were: 468 days (540-408), 362 days (405-328), 256 days (270-241) and 125 days (179-58). Based on the present results we recommend S-NSE and PS, in addition to stage, for prognostic stratification in treatment trials on SCLC.

Several studies of small cell lung cancer (SCLC) treatments have been performed in the United Kingdom. In some, prognostic factor analyses were carried out but the results were not entirely consistent. The Lung Cancer Subcommittee of the United Kingdom Coordinating Committee on Cancer Research (UKCCCR) consequently initiated an overview of these studies with the aim of identifying the important prognostic factors using a large number of patients. Information on almost 4,000 patients was available, but it was necessary to perform analyses on smaller subsets because the variables recorded in individual studies were inconsistent. A number of variables contributed significantly to the prediction of likely survival over the 6 months after starting treatment, but performance status (PS), alkaline phosphatase (AlkP) and disease stage were shown to be the most important; aspartate aminotransferase (AST) and lactate dehydrogenase (LDH) may also be useful. A prognostic index was devised for this initial period and validated using independent data. For patients who survived the first 6 months, the pre-treatment variables important for prognosis in the 6-24 month period were stage, PS and plasma sodium (Na). The Subcommittee recommends that performance status, disease stage, AlkP, Na, AST and LDH should be measured in all future SCLC studies to assist comparisons between studies and possibly the selection of patients for different treatment strategies. The additional recording of five other variables would allow a more definitive overview to be performed at some future date.

A lactate dehydrogenase-deficient (Ldh-) mutant of a human isolate of Streptococcus mutans serotype c was tested in a gnotobiotic rat caries model. Compared with the wild-type Ldh-positive (Ldh+) strains, it was significantly (alpha less than or equal to 0.005) less cariogenic in experiments with two different sublines of Sprague-Dawley rats. The Ldh- mutant strain 044 colonized the oral cavity of the test animals to the same extent as its parent strain 041, although its initial implantation was slightly but not significantly (P greater than or equal to 0.2) less. Multiple oral or fecal samples plated on 2,3,5-triphenyltetrazolium indicator medium revealed no evidence of back mutation from Ldh- to Ldh+ in vivo. Both Ldh+ strain 041 and Ldh- strain 044 demonstrated bacteriocinlike activity in vitro against a number of human strains of mutans streptococci representing serotype a (S. cricetus) and serotypes c and e (S. mutans). Serotypes b (S. rattus) and f (S. mutans) and strains of S. mitior, S. sanguis, and S. salivarius were not inhibited. Thus, Ldh mutant strain 044 possesses a number of desirable traits that suggest it should be investigated further as a possible effector strain for replacement therapy of dental caries. These traits include its stability and low cariogenicity in the sensitive gnotobiotic rat caries model, its bacteriocinlike activity against certain other cariogenic S. mutans (but not against more inocuous indigenous oral streptococci), and the fact that it is a member of the most prevalent human serotype of cariogenic streptococci.

The molecular mechanisms contributing to the development and progression of gingivobuccal complex (GBC) cancers–a sub-site of oral cancer, comprising the buccal mucosa, the gingivobuccal sulcus, the lower gingival region and the retromolar trigone-remain poorly understood. Identifying the GBC cancer-related gene expression signature and the driver genes residing on the altered chromosomal regions is critical for understanding the molecular basis of its pathogenesis. Genome-wide expression profiling of 27 GBC cancers with known chromosomal alterations was performed to reveal differentially expressed genes. Putative driver genes were identified by integrating copy number and gene expression data. A total of 315 genes were found differentially expressed (P≤0.05, logFC>2.0) of which eleven genes were validated by real-time quantitative reverse transcriptase-PCR (qRT-PCR) in tumors (n=57) and normal GBC tissues (n=18). Overexpression of LY6K, in chromosome band 8q24.3, was validated by immunohistochemical (IHC) analysis. We found that 78.5% (2,417/3,079) of the genes located in regions of recurrent chromosomal alterations show copy number dependent expression indicating that copy number alteration has a direct effect on global gene expression. The integrative analysis revealed BIRC3 in 11q22.2 as a candidate driver gene associated with poor clinical outcome. Our study identified previously unreported differentially expressed genes in a homogeneous subtype of oral cancer and the candidate driver genes that may contribute to the development and progression of the disease.