[Show abstract][Hide abstract] ABSTRACT: Circulating nucleic acids have been shown to have potential as non-invasive diagnostic markers in cancer. We therefore investigated whether microRNAs also have diagnostic utility by comparing levels of tumour-associated MIRN155 (miR-155), MIRN210 (miR-210) and MIRN21 (miR-21) in serum from diffuse large B-cell lymphoma (DLBCL) patients (n = 60) with healthy controls (n = 43). Levels were higher in patient than control sera (P = 0.009, 0.02 and 0.04 respectively). Moreover, high MIRN21 expression was associated with relapse-free survival (P = 0.05). This is the first description of circulating microRNAs and suggests that microRNAs have potential as non-invasive diagnostic markers for DLBCL and possibly other cancers.
British Journal of Haematology 06/2008; 141(5):672-5. DOI:10.1111/j.1365-2141.2008.07077.x · 4.71 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Major burn represents a multi-system insult to the human body. Despite improvements in mortality and morbidity, reliable predictors of outcome are lacking. Raised levels of cell-free nucleic acids have been detected in various pathological processes including burns. We quantified circulating nucleic acids as potential objective measures of burn severity with predictive and prognostic value.
Expression of endothelial specific cell-free mRNA and cell-free DNA were measured in plasma of 19 burn patients at days 1-3 and week 10 following acute thermal injury and in 19 healthy controls by real-time quantitative PCR.
Expression of endothelial specific mRNA was higher in burn patients compared to controls (p<0.001). DNA levels were significantly higher in the burn population in the first 48 h following injury. Plasma RNA and DNA levels related to %TBSA burn in the first 24h and to the levels of circulating endothelial progenitor cells.
We show that plasma levels of endothelial specific mRNA and DNA are elevated acutely following burns, and relate to severity in terms of %TBSA burnt.
[Show abstract][Hide abstract] ABSTRACT: Telomere shortening is associated with disease progression in chronic myeloid leukaemia (CML). To investigate the biology and regulation of telomerase in CML, we evaluated expression of the telomerase components, its regulators and several telomeric-associated proteins. Quantitative real-time-polymerase chain reaction (PCR) was used to compare gene expression in the CD34+/leukaemic blast cells of 22 CML patient samples to the CD34+ cell population of healthy individuals. hTERT, the catalytic component of telomerase, was downregulated in eight of 12 chronic phase (CP) patients (P = 0.0387). Furthermore, hTERT was significantly downregulated in two of three patients in accelerated phase (AP) and seven of seven patients in blast crisis (BC), P = 0.0017. Expression of hTR and telomeric-associated proteins TEP1, TRF1, TRF2, tankyrase and PinX1 was high in the majority of CP and AP patients. With the exceptions of TEP1 and hTR, expression of these factors was highest in CP and decreased during disease progression. Expression of c-Myc, a positive regulator of hTERT transcription, correlated with hTERT expression and decreased with disease progression, falling below control levels in BC. hTERT levels were increased in CP patients following successful treatment with imatinib, relative to untreated CP patients. We suggest that reduced hTERT expression directly causes the shortened telomeres observed in CML.
[Show abstract][Hide abstract] ABSTRACT: Cell-free DNA has been shown to have diagnostic potential in a number of malignant diseases. Recently, the integrity or size distribution of these fragments has also been identified as having possible diagnostic value. The current study explores the role of this novel parameter in the clinical diagnosis of prostate cancer. Plasma samples, collected prospectively from men undergoing investigation for prostate cancer, were used to obtain a cell-free DNA sample. Real-time PCR was used to quantify the level of cell-free DNA (ng/ml) and its size distribution (delta CD in each case. Sixty-one samples were collected from patients with prostate cancer and 62 from those with benign histology. Analysis failed to reveal a statistically significant relationship between either the level of cell-free DNA (p = 0.82) or its size distribution (p = 0.91) and the presence of cancer. These results demonstrate that cell-free DNA is unlikely to be of diagnostic value in the clinical management of this disease.
Oncology Research Featuring Preclinical and Clinical Cancer Therapeutics 02/2006; 16(1):35-41. · 1.06 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: This chapter describes the application of polymerase chain reaction (PCR) for the detection and quantitation of Plasmodium falciparum DNA in the plasma of malaria-infected individuals. The procedure includes the following protocols: plasma sample preparation, DNA extraction, detection of P. falciparum DNA in the plasma by nested PCR, and quantitation of P. falciparum DNA in the plasma by real-time PCR technology.
[Show abstract][Hide abstract] ABSTRACT: The virulence of the malaria parasite Plasmodium falciparum is due, in part, to its ability to cytoadhere in deep vascular beds. Our inability to quantify the load of sequestered parasites hampers our understanding of the pathophysiological mechanisms involved in disease progression and complicates diagnosis. In this study we evaluate potential biochemical markers of sequestered load by comparing them with estimates of the sequestered load from a statistical model fitted to longitudinal patterns of peripheral parasite densities in a series of 22 patients with severe Plasmodium falciparum malaria. The markers comprised the host factors: haematocrit, circulating host DNA, sTNF-R75 and parasite derived products HRP2, pLDH, pigments and circulating parasite DNA. We investigated the suitability of these markers in determining sequestered loads in patients on quinine treatment. Observed peripheral parasitaemia, plasma levels of sTNF-R75 and circulating parasite DNA were most strongly correlated with estimates of sequestered loads on admission. However the dynamics of both sTNF-R75 and circulating parasite DNA during follow-up were very different from those of the estimated sequestered mass. These analyses suggest that none of the markers gave reliable estimates of the current sequestered load, though they may reflect the history of infection. Longitudinal analyses are needed that allow for the clearance rates of the marker molecules and for variations between hosts in the history of parasitaemia.
[Show abstract][Hide abstract] ABSTRACT: The aim of this study was to determine the potential of cell-free DNA levels as a diagnostic marker for prostate cancer, having first established the effect that blood sample processing has on this measurement.
A total of 152 blood samples were collected prospectively from patients before their prostate biopsy and 25 from men in two distinct control groups. Blood was processed to yield three components: one-spin plasma (n = 68), two-spin plasma (n = 152), and serum (n = 56) samples.
Having established the effect of sample preparation on the measured DNA level, the more reliable two-spin plasma sample was used to determine the relationship between DNA and the presence of prostate cancer. Those patients with cancer (n = 78) had a significantly higher level of DNA compared with the control groups (P < 0.0001 and P < 0.0001). However, DNA levels in patients with a benign biopsy (n = 74) were significantly higher than the 78 patients confirmed to have cancer (P = 0.02).
We conclude that the sample type used in the quantitation of cell-free DNA has an effect on the level reported. Elevated levels are present in the two-spin plasma samples of patients with prostate cancer compared with healthy controls but are not of diagnostic value during the management of prostate cancer.
Clinical Cancer Research 03/2005; 11(4):1394-9. DOI:10.1158/1078-0432.CCR-04-1237 · 8.72 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The purpose of this study was to quantify the level of serum DNA in different groups of primary breast cancer patients and in healthy controls using real-time quantitative PCR in order to determine whether such measurements have diagnostic or prognostic value. A total of 96 serum samples of patients with primary breast cancer before surgery (with positive or negative lymph nodes and with high or low relapse-free survival) as well as 24 healthy controls were analysed. DNA concentrations in the serum of the patients differed significantly from the concentration of serum DNA in the controls (medians were 221 and 63 ng x ml(-1), respectively, P<0.001 M-W test). However, no statistically significant difference was observed between the patient groups (P=0.87, M-W test). The serum DNA levels were elevated independently of the size of primary tumour or lymph node metastases. The overall survival of patients with serum DNA concentrations >221 ng x ml(-1) was better than patients with serum DNA concentration <or=221 ng ml(-1) (Kaplan-Meier, P=0.028).
British Journal of Cancer 03/2004; 90(6):1211-5. DOI:10.1038/sj.bjc.6601609 · 4.84 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: It has been suggested that mammaglobin may be a useful marker for breast cancer clinical research. Studies investigating the detection of mRNA by RT-PCR from circulating carcinoma cells in the peripheral blood of breast cancer patients have shown that mammaglobin is a highly specific marker and correlates with several prognostic factors, such as lymph node involvement. We aimed to detect cell-free mammaglobin mRNA in the plasma of breast cancer patients and to investigate whether it can be used as a marker for diagnosis of breast cancer.
Annals of the New York Academy of Sciences 10/2001; 945(1):192-4. DOI:10.1111/j.1749-6632.2001.tb03885.x · 4.38 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: We present a new application in the field of circulating nucleic acids in plasma: the detection of parasite DNA in plasma. We have investigated the presence of Plasmodium falciparum (P. falciparum) DNA in the blood cells and plasma of patients with malaria. Ten blood samples from malaria patients and 9 blood samples from healthy volunteers were collected. Plasma was separated and DNA was extracted from both plasma and blood cells. DNA samples were subjected to a nested polymerase chain reaction (PCR) for the small subunit rRNA gene of P. falciparum and a control amplification of the human rRNA gene. All 6 cases positive by microscopy for P. falciparum were positive by PCR on DNA extracted from blood cells and plasma. Two cases negative by microscopy for malaria were positive by PCR--the blood samples were taken from one of the cases at 7 days after successful treatment of malaria and the other case at the onset of the malaria illness. Two other cases were negative by microscopy and by PCR on blood cells and plasma, both after successful treatment of malaria. The quantitation of Plasmodium DNA in plasma may prove to be a useful prognostic measurement in malaria, and the detection of P. falciparum DNA in archival stored plasma samples may allow the reconstruction of the recent historic evolution of the parasite genome.
Annals of the New York Academy of Sciences 10/2001; 945(1):234-8. DOI:10.1111/j.1749-6632.2001.tb03891.x · 4.38 Impact Factor