Altered phosphorylation status, phospholipid metabolism and gluconeogenesis in the host liver of rats with prostate cancer: a 31P magnetic resonance spectroscopy study

Rat prostate tumors induce DNA synthesis in remote organs

Advanced cancers induce systemic responses. However, if such systemic changes occur already when aggressive tumors are small, have not been thoroughly characterized. Here, we examined how localized prostate cancers of different sizes and metastatic potential affected DNA synthesis in the rest of the prostate and in various remote organs. Non-metastatic Dunning R-3327 G (G) tumor cells, metastatic MatLyLu (MLL) tumor cells, or vehicle were injected into the prostate of immunocompetent rats. All animals received daily injections of Bromodeoxyuridine (BrdU), to label cells/daughter cells with active DNA synthesis. Equal sized G- and MLL-tumors, similarly increased BrdU-labeling in the prostate, lymph nodes and liver compared to tumor-free controls. Prior to metastasis, MLL-tumors also increased BrdU-labeling in bone marrow and lungs compared to animals with G-tumors or controls. In animals with MLL-tumors, BrdU-labeling in prostate, lungs, brown adipose tissue and skeletal muscles increased in a tumor-size-dependent way. Furthermore, MLL-tumors induced increased signs of DNA damage (γH2AX staining) and accumulation of CD68 + macrophages in the lungs. In conclusion, small localized prostate cancers increased DNA synthesis in several remote tissues in a tumor type- and size-dependent way. This may suggest the possibility for early diagnosis of aggressive prostate cancer by examining tumor-induced effects in other tissues.

Systemic antioxidant and anti-inflammatory effects of yellow passion fruit bagasse extract during prostate cancer progression

We evaluated the impact of yellow passion fruit (Passiflora edulis sp.) bagasse extract (PFBE) administration in systemic oxidative and inflammatory parameters in vivo, considering prostate cancer progression in transgenic mice (TRAMP). Piceatannol, scirpusin-B, dicaffeoylquinic acid, citric acid, and (+)-catechin were identified in PFBE, and the extract showed high in vitro antioxidant capacity. Some alterations in systemic parameters were verified during prostate cancer progression, as the increase in ALT and MDA levels, and SOD and GPx activities in the plasma. In the liver, higher MDA, TNF-α, and NF-κB levels, and GR and GPx activities were verified. Compared to their respective controls, the short- and long-term PFBE administration reduced MDA levels in the liver and plasma. The long-term treatment increased the catalase activity in the plasma, while the short-term treatment increased the hepatic SOD and catalase activities. Still, a reduction in hepatic TNF-α and NF-κB levels was verified after long-term treatment. PRACTICAL APPLICATIONS: Prostate cancer progression is associated with changes in systemic redox status and inflammation markers. Moreover, the intake of polyphenols with antioxidant properties, besides delaying prostate carcinogenesis, may improve the systemic antioxidant defenses and inflammatory response. In vitro studies pointed to a promising antioxidant and anti-inflammatory potential of yellow passion fruit bagasse. However, in vivo studies are scarce. Our results provided information about in vivo impacts of PFBE oral consumption on antioxidant defense and inflammation, indicating its potential as an adjuvant during the initial steps of prostate cancer.

In vivo magnetic resonance spectroscopy of liver tumors and metastases

Primary liver cancer is the fifth most common malignancy in men and the eighth in women worldwide. The liver is also the second most common site for metastatic spread of cancer. To assist in the diagnosis of these liver lesions non-invasive advanced imaging techniques are desirable. Magnetic resonance (MR) is commonly used to identify anatomical lesions, but it is a very versatile technique and also can provide specific information on tumor pathophysiology and metabolism, in particular with the application of MR spectroscopy (MRS). This may include data on the type, grade and stage of tumors, and thus assist in further management of the disease. The purpose of this review is to summarize and discuss the available literature on proton, phosphorus and carbon-13-MRS as performed on primary liver tumors and metastases, with human applications as the main perspective. Upcoming MRS approaches with potential applications to liver tumors are also included. Since knowledge of some technical background is indispensable to understand the results, a basic introduction of MRS and some technical issues of MRS as applied to tumors and metastases in the liver are described as well. In vivo MR spectroscopy of tumors in a metabolically active organ such as the liver has been demonstrated to provide important information on tumor metabolism, but it also is challenging as compared to applications on some other tissues, in particular in humans, mostly because of its abdominal location where movement may be a disturbing factor.

Non-mammalian fat-1 gene prevents neoplasia when introduced to a mouse hepatocarcinogenesis model: Omega-3 fatty acids prevent liver neoplasia

We investigated the effect of a non-mammalian omega-3 desaturase in a mouse hepatocarcinogenesis model. Mice containing double mutations (DM) in c-myc and TGF-alpha (transforming growth factor-alpha), leading to liver neoplasia, were crossed with mice containing omega-3 desaturase. MRI analysis of triple mutant (TM) mice showed the absence of neoplasia at all time points for 92% of mice in the study. Pathological changes of TM (TGFalpha/c-myc/fat-1) mouse liver tissue was similar to control mouse liver tissue. Magnetic resonance spectroscopy (MRS) measurements of unsaturated fatty acids found a significant difference (p<0.005) between DM and TM transgenic (Tg) mice at 34 and 40 weeks of age. HPLC analysis of mouse liver tissue revealed markedly decreased levels of omega-6 fatty acids in TM mice when compared to DM (TGFalpha/c-myc) and control (CD1) mice. Mass spectrometry (MS) analysis indicated significantly decreased 16:0/20:4 and 18:1/20:4 and elevated 16:0/22:6 fatty acyl groups in both GPCho and GPEtn, and elevated 16:0/20:5, 18:0/18:2, 18:0/18:1 and 18:0/22:6 in GPCho, within TM mice compared to DM mice. Total fatty acid analysis indicated a significant decrease in 18:1n9 in TM mice compared to DM mice. Western blot analysis of liver tissue showed a significant (p<0.05) decrease in NF-kappaB (nuclear factor-kappaB) levels at 40 weeks of age in TM mice compared to DM mice. Microarray analysis of TM versus DM mice livers at 40 weeks revealed alterations in genes involved in cell cycle regulation, cell-to-cell signaling, p53 signaling, and arachidonic acid (20:4) metabolism. Endogenous omega-3 fatty acids were found to prevent HCC development in mice.

Phosphomonoester concentrations differ between chronic lymphocytic leukemia cells and normal human lymphocytes

Levels of phospholipid-related metabolites of chronic lymphocytic leukemia lymphocytes (CLL) and normal human lymphocytes were quantified using phosphorus magnetic resonance spectroscopy. The CLL cells versus normal lymphocytes showed significant increases of phosphoethanolamine(Etn-P) (8.11+/-2.10 mean+/-S.E., micromol/g wet weight, n=12 versus 3.63+/-1.10, n=3, P<or=0.002), phosphocholine (2.10+/-0.37, n=12 versus 0.36+/-0.09, n=3, P<or=0.01), glycerophosphoethanolamine (0.26+/-0.03, n=10 versus 0.11+/-0.05, n=3, P<or=0.004), and glycerophosphocholine (0.33+/-0.03, n=10 versus 0.17+/-0.05, n=3, P<or=0.003). Further, the phospholipid precursor ethanolamine (Eth) was studied in blood and was found significantly lowered in CLL patients (4.6+/-1.6 microM, n=25) compared to normal volunteers (7.7+/-2.5, n=12, P<or=0.001). Increased intermediates with depletion of precursors suggest the presence of sustained phospholipid metabolism activation in CLL.

Adenosine triphosphate infusion increases liver energy status in advanced lung cancer patients: an in vivo 31P magnetic resonance spectroscopy study

We recently observed inhibition of weight loss in patients with advanced nonsmall-cell lung cancer after intravenous infusion of ATP. Because liver ATP levels were found to be decreased in lung cancer patients with weight loss, the present 31P magnetic resonance spectroscopy (MRS) study was aimed at investigating whether ATP infusion restores liver energy status in these patients. Nine patients with advanced nonsmall-cell lung cancer (stage IIIB/IV) were studied 1 week before (baseline) and at 22 to 24 hours of continuous ATP infusion (37-75 microg/kg/min). Localized hepatic 31P MR spectra (repetition time 15 seconds), obtained in the overnight-fasted state, were analyzed for ATP and P(i) content. Ten healthy subjects (without ATP infusion) served as control. Liver ATP levels in lung cancer patients increased from 8.8 +/- 0.7% (relative to total MR-detectable phosphate; mean +/- SE) at baseline to 12.2 +/- 0.9% during ATP infusion (P <.05), i.e., a level similar to that in healthy subjects (11.9 +/- 0.9%). The increase in ATP level during ATP infusion was most prominent in patients with > or = 5% weight loss (baseline: 7.9 +/- 0.7%, during ATP infusion: 12.8 +/- 1.0%, P < 0.01). In conclusion, ATP infusion restores hepatic energy levels in patients with advanced lung cancer, especially in weight-losing patients. These changes may contribute to the previously reported beneficial effects of ATP infusion on the nutritional status of lung cancer patients.

Decreased energy and phosphorylation status in the liver of lung cancer patients with weight loss

BACKGROUND/AIMS

Altered energy status has been reported in the liver of tumour-bearing animals, but data on energy status in humans are scarce. Therefore, bioenergetics in tumour-free liver of lung cancer patients were monitored using 31P magnetic resonance spectroscopy (MRS) with infusion of L-alanine as a gluconeogenic challenge.

METHODS

Twenty-one overnight-fasted lung cancer patients without liver metastases, with (CaWL) or without weight loss (CaWS), and 12 healthy control subjects (C) were studied. Hepatic energy status was monitored before and during an i.v. L-alanine infusion of 1.4-2.8 mmol/kg + 2.8 mmol x kg(-1) x h(-1) for 90 min by 31p MR spectroscopy.

RESULTS

Baseline levels of ATP in WL lung cancer patients, expressed relative to total MR-detectable phosphate, were reduced (CaWL, 9.5+/-0.9% vs. CaWS, 12.6+/-0.8% and C, 12.4+/-0.8%; p<0.05) and inversely correlated with the degree of weight loss in lung cancer patients (r=-0.46, p=0.03). Pi/ATP ratios were increased (p<0.05), indicating reduced liver phosphorylation status. During L-alanine infusion, ATP levels decreased in all groups (p<0.05); in CaWL, ATP levels were lower at all time-points between 0-90 min as compared to both CaWS and C (p<0.05). Pi/ATP ratios were significantly higher after 70-90 min of L-alanine infusion in CaWL compared to CaWS and C (p<0.05).

CONCLUSIONS

Hepatic ATP and phosphorylation status are reduced in WL lung cancer patients, in contrast to WS patients and healthy subjects, and continue to decrease during infusion of a gluconeogenic substrate, suggesting impaired energy regenerating capacity in these patients.

Abnormal liver metabolism in cancer patients detected by (31)P MR spectroscopy

There is accumulating evidence indicating that the presence of malignant disease is accompanied by profound changes of liver metabolism in the cancer-bearing host. We previously reported [P. C. Dagnelie, J. D. Bell, -S. C. R. Williams, T. E. Bates, P. D. Abel and C. S. Foster, Br. J. Cancer 67, 1303-1309 (1993)] marked (31)P MRS-detected alterations in phosphorylation status as well as in phospholipid and glucose metabolism in the liver of rats bearing Dunning prostate tumours. The aim of the present study was first to define abnormalities in liver metabolism in patients with a distant malignancy using (31)P MRS, and second to explore the value of including long-TR sequences in clinical (31)P MRS studies of the liver. Liver metabolite levels were expressed relative to total MR-detectable phosphate. In weight-losing (WL, n = 10), but not in weight-stable (WS, n = 13) cancer patients, liver phosphomonoester (PME) levels were significantly elevated, whereas phosphodiester (PDE) levels were reduced when compared with age-matched healthy subjects (n = 12). The TR 20:1 s ratio of PDE was increased in WS and WL cancer patients, suggesting longer T(1). At TR 20 s, but not at TR 1 s, ATP levels were significantly reduced in in WS and WL cancer patients compared with healthy subjects; similarly, P(i) levels were reduced in WL patients at TR 20 and 5s, but not at TR 1 s. ATP:P(i) ratios were unchanged regardless of TR. pH values increased in the order: healthy < cancer-WS < cancer-WL. The PME chemical shift had significantly moved downfield in cancer patients, reflecting increased contributions from glycolytic/gluconeogenic intermediates. The observed changes in PME are consistent with previous reports suggesting increased gluconeogenesis in the liver of patients with a distant malignant tumour. Furthermore, our data support the use of including long-TR sequences in clinical (31)P MRS liver studies.

Metabolic changes underlying 31P MR spectral alterations in human hepatic tumours

Magnetic resonance spectroscopy (MRS) remains the technique of choice for observing tumour metabolism non-invasively. Although initially 31P MR spectroscopy showed much promise as a non-invasive diagnostic tool, studies of a wide range of hepatic tumours have conclusively shown that this technique cannot be utilized to distinguish between different tumour types. This lack of specificity and sensitivity appears to be a consequence of the fact that hepatic tumours develop with a range of modalities and not as a single abnormal disease process, and also because of the limited availability of MR detectable metabolic markers. This has led, in recent years, to a re-evaluation of the role of 31P MR spectroscopy, re-emerging as a non-invasive tool to follow the efficacy of the treatment regime. Furthermore, since the principal changes observed in tumours by 31P MRS appear to be an elevation in the concentration of phosphorylcholine (PCho) and phosphoethanolamine (PEth), new research using a combination of MRS and tissue culture of cell lines which carry a combination of known inducible oncogenes, are helping to elucidate some of the metabolic pathways that give rise to these metabolic alterations.

In vivo and in vitro hepatic phosphorus-31 magnetic resonance spectroscopy and electron microscopy in chronic ductopenic rejection of human liver allografts

BACKGROUND

In vivo hepatic phosphorus-31 magnetic resonance spectroscopy (MRS) provides non-invasive information about phospholipid metabolism.

AIMS

To delineate MRS abnormalities in patients with chronic ductopenic rejection (CDR) and to characterise spectral changes by in vitro MRS and electron microscopy.

PATIENTS AND METHODS

Sixteen liver transplant recipients (four with CDR; 12 with good graft function) and 29 controls (23 healthy volunteers; six patients with biliary duct strictures) were studied with in vivo 31P MRS. Peak area ratios of phosphomonoesters (PME) and phosphodiesters (PDE), relative to nucleotide triphosphates (NTP) were measured. In vitro MRS and electron microscopy were performed on biopsy specimens from five patients with CDR, freeze clamped at retransplantation. Phosphoethanolamine (PE), phosphocholine (PC), glycerophosphorylethanolamine (GPE), and glycerophosphorylcholine (GPC) concentrations were measured.

RESULTS

The 12 patients with good graft function displayed no spectral abnormalities in vivo; the four patients with CDR showed significantly elevated PME:NTP (p < 0.01) and PDE:NTP ratios (p < 0.005). Patients with biliary strictures had significant differences in PME:NTP (p < 0.01) from patients with CDR, but not in mean PDE:NTP. In vitro spectra from CDR patients showed elevated PE and PC, mirroring the in vivo changes in PME, but reduced GPE and GPC concentrations were observed, at variance with the in vivo PDE findings. On electron microscopy, there was no proliferation in hepatocyte endoplasmic reticulum.

CONCLUSIONS

The increase in PME:NTP reflects altered phospholipid metabolism in patients with CDR, while the increase in PDE:NTP may represent a significant contribution from bile phospholipid.

Elevated expression of calcium-binding protein p9Ka is associated with increasing malignant characteristics of rat prostate carcinoma cells

Northern and Western blotting techniques were used to study expression of the mRNA and corresponding protein product of the S100-related calcium-binding molecule p9Ka in 6 different metastatic cell lines of the Dunning R3327 rat prostate cancer model. In cells with the lowest metastatic capability (G cells), p9Ka mRNA was barely detectable. In 2 weakly metastatic cell lines (AT-1 and AT-2), p9Ka transcript amounts were, respectively, 6.29 +/- 0.74 and 5.55 +/- 1.11 times that detected in the G cells. In 3 highly metastatic cell lines (AT-3, MAT-LyLu and MAT-Lu), the amounts of p9Ka mRNA were, respectively, 12.85 +/- 2.82, 13.06 +/- 1.69 and 11.62 +/- 1.81 times that expressed in the G cells. Western blot analyses detected no p9Ka protein in the G cells. The amounts of p9Ka protein expressed by tumour cells of intermediate metastatic capability (AT-1 and AT-2) were 3.4 +/- 1.3 microg and 3.3 +/- 1.4 microg, respectively, per 1 x 10(6) cells. The amounts of p9Ka protein expressed by the tumour cells of highest metastatic capability (AT-3, MAT-LyLu and MAT-Lu) were 8.3 +/- 1.1 microg, 8.7 +/- 1.6 microg and 9.6 +/- 1.7 microg, respectively, per 1 x 10(6) cells. Our data reveal a direct association between the elevated expression of mRNA and the p9Ka protein amounts and the increased metastatic capability of individual prostatic cancer cell lines. We suggest that calcium-binding protein p9Ka may play an important role in the metastatic behaviour of rat prostate cancer.

Effect of fish oil on cancer cachexia and host liver metabolism in rats with prostate tumors

The aim of this study was to investigate whether tumor-induced cachexia and aberrations in host liver metabolism, induced by the MAT-LyLu variant of the Dunning prostate tumor, could be prevented by omega 3 fatty acids from fish oil. On day 0, adult Copenhagen-Fisher rats fed normal chow ad libitum were inoculated with 10(6) MAT-LyLu cells (n = 14) or saline (n = 9). On day 7, when tumors were palpable, four tumor-bearing (TB) and four nontumor-bearing (NTB) rats were put on isocaloric diets with 50% of total energy as fish oil. The introduction of fish oil-enriched diets caused a reduction in energy intake to less than half of the energy intake by animals fed normal diets during days 7-14 (difference by dietary group: NTB, P < 0.001; TB, P < 0.001). During days 14-21, energy intake in fish oil-fed animals returned to approximately 75% of energy intake by animals fed normal diets (difference by dietary group: NTB, P < 0.003; TB, P = 0.001). Carcass weight of animals on day 21, when the study was terminated, was significantly related to initial weight (P = 0.05) and mean food intake during the study (P = 0.01). When data were adjusted for these variables using analysis of covariance, with NTB animals on normal diets being the reference group, significant loss of carcass weight was observed in TB animals on normal diets only (mean +/- SEM 58 +/- 10 g loss, P < 0.001), but not in TB animals on fish oil diets (8 +/- 18 g loss, P = 0.67).(ABSTRACT TRUNCATED AT 250 WORDS)