Genome-wide cell-free DNA fragmentation in patients with cancer

Cell-free DNA in the blood provides a non-invasive diagnostic avenue for patients with cancer1. However, characteristics of the origins and molecular features of cell-free DNA are poorly understood. Here we developed an approach to evaluate fragmentation patterns of cell-free DNA across the genome, and found that profiles of healthy individuals reflected nucleosomal patterns of white blood cells, whereas patients with cancer had altered fragmentation profiles. We used this method to analyse the fragmentation profiles of 236 patients with breast, colorectal, lung, ovarian, pancreatic, gastric or bile duct cancer and 245 healthy individuals. A machine learning model that incorporated genome-wide fragmentation features had sensitivities of detection ranging from 57% to more than 99% among the seven cancer types at 98% specificity, with an overall area under the curve value of 0.94. Fragmentation profiles could be used to identify the tissue of origin of the cancers to a limited number of sites in 75% of cases. Combining our approach with mutation-based cell-free DNA analyses detected 91% of patients with cancer. The results of these analyses highlight important properties of cell-free DNA and provide a proof-of-principle approach for the screening, early detection and monitoring of human cancer.

The neuropeptide Y/agouti gene-related protein (AGRP) brain circuitry in normal, anorectic, and monosodium glutamate-treated mice

Neuropeptide Y (NPY) and the endogenous melanocortin receptor antagonist, agouti gene-related protein (AGRP), coexist in the arcuate nucleus, and both exert orexigenic effects. The present study aimed primarily at determining the brain distribution of AGRP. AGRP mRNA-expressing cells were limited to the arcuate nucleus, representing a major subpopulation (95%) of the NPY neurons, which also was confirmed with immunohistochemistry. AGRP-immunoreactive (-ir) terminals all contained NPY and were observed in many brain regions extending from the rostral telencephalon to the pons, including the parabrachial nucleus. NPY-positive, AGRP-negative terminals were observed in many areas. AGRP-ir terminals were reduced dramatically in all brain regions of mice treated neonatally with monosodium glutamate as well as of mice homozygous for the anorexia mutation. Terminals immunoreactive for the melanocortin peptide alpha-melanocyte-stimulating hormone formed a population separate from, but parallel to, the AGRP-ir terminals. Our results show that arcuate NPY neurons, identified by the presence of AGRP, project more extensively in the brain than previously known and indicate that the feeding regulatory actions of NPY may extend beyond the hypothalamus.

Genotype tunes pancreatic ductal adenocarcinoma tissue tension to induce matricellular fibrosis and tumor progression

Fibrosis compromises pancreatic ductal carcinoma (PDAC) treatment and contributes to patient mortality, yet antistromal therapies are controversial. We found that human PDACs with impaired epithelial transforming growth factor-β (TGF-β) signaling have high epithelial STAT3 activity and develop stiff, matricellular-enriched fibrosis associated with high epithelial tension and shorter patient survival. In several KRAS-driven mouse models, both the loss of TGF-β signaling and elevated β1-integrin mechanosignaling engaged a positive feedback loop whereby STAT3 signaling promotes tumor progression by increasing matricellular fibrosis and tissue tension. In contrast, epithelial STAT3 ablation attenuated tumor progression by reducing the stromal stiffening and epithelial contractility induced by loss of TGF-β signaling. In PDAC patient biopsies, higher matricellular protein and activated STAT3 were associated with SMAD4 mutation and shorter survival. The findings implicate epithelial tension and matricellular fibrosis in the aggressiveness of SMAD4 mutant pancreatic tumors and highlight STAT3 and mechanics as key drivers of this phenotype.

MicroRNA biomarkers in whole blood for detection of pancreatic cancer

IMPORTANCE

Biomarkers for the early diagnosis of patients with pancreatic cancer are needed to improve prognosis.

OBJECTIVES

To describe differences in microRNA expression in whole blood between patients with pancreatic cancer, chronic pancreatitis, and healthy participants and to identify panels of microRNAs for use in diagnosis of pancreatic cancer compared with the cancer antigen 19-9 (CA19-9).

DESIGN, SETTING, AND PARTICIPANTS

A case-control study that included 409 patients with pancreatic cancer and 25 with chronic pancreatitis who had been included prospectively in the Danish BIOPAC (Biomarkers in Patients with Pancreatic Cancer) study (July 2008-October 2012) plus 312 blood donors as healthy participants. The microRNA expressions in pretreatment whole blood RNA samples were collected and analyzed in 3 randomly determined subcohorts: discovery cohort (143 patients with pancreatic cancer, 18 patients with chronic pancreatitis, and 69 healthy participants), training cohort (180 patients with pancreatic cancer, 1 patient with chronic pancreatitis, and 199 healthy participants), and validation cohort (86 patients with pancreatic cancer, 7 patients with chronic pancreatitis, and 44 healthy participants); 754 microRNAs were screened in the discovery cohort and 38 microRNAs in the training cohort and 13 microRNAs in the validation cohort.

MAIN OUTCOMES AND MEASURES

Identification of microRNA panels (classifiers) for diagnosing pancreatic cancer.

RESULTS

The discovery cohort demonstrated that 38 microRNAs in whole blood were significantly dysregulated in patients with pancreatic cancer compared with controls. These microRNAs were tested in the training cohort and 2 diagnostic panels were constructed comprising 4 microRNAs in index I (miR-145, miR-150, miR-223, miR-636) and 10 in index II (miR-26b, miR-34a, miR-122, miR-126*, miR-145, miR-150, miR-223, miR-505, miR-636, miR-885.5p). The test characteristics for the training cohort were index I area under the curve (AUC) of 0.86 (95% CI, 0.82-0.90), sensitivity of 0.85 (95% CI, 0.79-0.90), and specificity of 0.64 (95% CI, 0.57-0.71); index II AUC of 0.93 (95% CI, 0.90-0.96), sensitivity of 0.85 (95% CI, 0.79-0.90), and specificity of 0.85 (95% CI, 0.80-0.85); and CA19-9 AUC of 0.90 (95% CI, 0.87-0.94), sensitivity of 0.86 (95% CI, 0.80-0.90), and specificity of 0.99 (95% CI, 0.96-1.00). Performances were strengthened in the validation cohort by combining panels and CA19-9 (index I AUC of 0.94 [95% CI, 0.90-0.98] and index II AUC of 0.93 [95% CI, 0.89-0.97]). Compared with CA19-9 alone, the AUC for the combination of index I and CA19-9 was significantly higher (P = .01). The performance of the panels in patients with stage IA-IIB pancreatic cancer was index I AUC of 0.80 (95% CI, 0.73-0.87); index I and CA19-9 AUC of 0.83 (95% CI, 0.76-0.90); index II AUC of 0.91 (95% CI, 0.87-0.94); and index II and CA19-9 AUC of 0.91 (95% CI, 0.86-0.95).

CONCLUSIONS AND RELEVANCE

This study identified 2 diagnostic panels based on microRNA expression in whole blood with the potential to distinguish patients with pancreatic cancer from healthy controls. Further research is necessary to understand whether these have clinical implications for early detection of pancreatic cancer and how much this information adds to serum CA19-9.

Serum YKL-40, a new prognostic biomarker in cancer patients?

YKL-40, a member of the "mammalian chitinase-like proteins," is expressed and secreted by several types of solid tumors. The exact function of YKL-40 in cancer diseases is unknown and is an important objective of future studies. YKL-40 exhibits growth factor activity for cells involved in tissue remodeling processes. YKL-40 may have a role in cancer cell proliferation, survival, and invasiveness, in the inflammatory process around the tumor, angiogenesis, and remodeling of the extracellular matrix. YKL-40 is neither organ- nor tumor-specific. However, the present retrospective clinical studies of patients with eight different types of primary or advanced solid tumors suggest that serum concentration of YKL-40 may be a new biomarker in cancer patients used as a "prognosticator." Elevated serum YKL-40 is found in a subgroup of patients with different types of solid tumors, including several types of adenocarcinomas, small cell lung carcinoma, glioblastoma, and melanoma. The highest serum YKL-40 is detected in patients with advanced cancer and with the poorest prognosis. In many cases, serum YKL-40 provides independent information of survival. Serum YKL-40 cannot be used as a single screening test for cancer. The use of serum YKL-40 has not received Food and Drug Administration approval for use as a biomarker for cancer or any other disease. Large multicenter retrospective and prospective studies of patients with different types of cancer are required to determine: (a) if serum YKL-40 is a useful prognostic cancer biomarker, (b) if serum YKL-40 can be of value in monitoring patients with cancer in order to provide information about metastases before these are detected by routine methods, and (c) if serum YKL-40 can be useful for screening of cancer together with a panel of other cancer biomarkers and imaging techniques.

Effect of menopause and hormone replacement therapy on the urinary excretion of pyridinium cross-links

Pyridinoline (Pyr) and deoxypyridinoline (D-Pyr) are two cross-links of collagen molecules that are present in the extracellular matrix and released during its degradation. In contrast to the wide distribution of collagen, Pyr is present in bone and cartilage, but not in significant amounts in other connective tissues, and D-Pyr appears to be specific for bone tissue. Therefore, the urinary excretion of Pyr and D-Pyr might be a sensitive marker of bone matrix degradation. Using a specific high pressure liquid chromatography assay we have measured Pyr and D-Pyr cross-links in a 24-h and a fasting urine sample in 60 early postmenopausal women and 19 premenopausal women matched for age. Menopause induced a 62% increase in Fu Pyr (49.8 +/- 18.7 vs. 30.8 +/- 8.0 pmol/mumol creatinine; P less than 0.001) and an 82% increase in Fu D-Pyr (8.2 +/- 3.4 vs. 4.5 +/- 1.4 pmol/mumol creatinine; P less than 0.001). In 20 postmenopausal women on hormone replacement therapy, urinary Pyr and D-Pyr returned to premenopausal levels within 6 months, contrasting with unchanged levels during placebo treatment. The 24-h excretion of Pyr and D-Pyr was significantly lower than the fasting excretion, but was similarly decreased after hormone replacement therapy. Pyr and D-Pyr excretion measured in the same urinary sample were highly correlated (r = 0.85 for fasting and 0.83 for 24-h sampling), but correlations between fasting and 24-h values were weak (D-Pyr, r = 0.30; Pyr, r = 0.29; P less than 0.05 for both). Correlations between urinary cross-links and other markers of bone turnover (Fu hydroxyproline/creatinine and plasma osteocalcin) were significant but low (Pyr vs. osteocalcin, r = 0.29, P less than 0.05; Pyr vs. hydroxyproline, r = 0/.34; P less than 0.01; D-Pyr vs. osteocalcin, r = 0.39; P less than 0.01), except for D-Pyr vs. hydroxyproline (r = 0.24; P = 0.07), suggesting that these markers reflect different events of bone metabolism. Finally, a single measurement of the fasting excretion, but not of the 24-h excretion, of cross-links was significantly correlated (Pyr, r = 0.34; P less than 0.05; D-Pyr, r = -0.46; P less than 0.01), with the subsequent spontaneous rate of bone loss assessed by repeated measurements of the radial bone mineral content in 37 postmenopausal women.(ABSTRACT TRUNCATED AT 400 WORDS)

Serum YKL-40 is increased in patients with hepatic fibrosis

BACKGROUND/AIMS

YKL-40, a mammalian member of the chitinase family, is a lectin that binds heparin and chitin. The function of YKL-40 is unknown, but it may function in tissue remodelling. The aims of this study were to assess the level of circulating YKL-40 in patients with various kinds and degree of chronic liver disease and its possible relation to liver fibrosis.

METHODS

Serum YKL-40 levels were determined by radioimmunoassay in 129 patients with suspected liver disease and related to histological findings and immunohistochemical staining of YKL-40 in a liver biopsy taken simultaneously with the blood sample.

RESULTS

The median serum YKL-40 was highest in patients with alcoholic cirrhosis (532 microg/l), in particular in patients with additional alcoholic hepatitis (740 microg/l). Patients with alcoholic cirrhosis, post-hepatitic cirrhosis (425 microg/l) and non-cirrhotic fibrosis (330 microg/l) had significantly higher serum YKL-40 than normal subjects (102 microg/l), patients with fatty liver (195 microg/l) or patients with viral hepatitis without fibrosis (174 microg/l). Serum YKL-40 was significantly (p<0.001) related to the degree of liver fibrosis with the highest levels in patients with moderate (466 microg/l) to severe (676 microg/l) fibrosis. Serum YKL-40 was also increased (p=0.018) in patients with slight fibrosis (270 microg/l) compared to patients without fibrosis. Immunohistochemical analysis demonstrated positive staining for YKL-40 antigen in areas with fibrosis, particularly areas with active fibrogenesis. YKL-40 staining was never found in hepatocytes.

CONCLUSIONS

Our study indicates that the increased serum YKL-40 in patients with liver disease of various degree and aetiology seems to reflect fibrosis and fibrogenesis.

Identification of proteins secreted by human osteoblastic cells in culture

To better understand the biochemistry of matrix-forming cells, we developed a simple and reproducible procedure for the isolation and identification by N-terminal sequencing of proteins secreted by cells into culture medium and applied this procedure to the analysis of the major Coomassie blue-staining proteins under 100 kD that are secreted from three different human osteoblastic cell cultures. The major proteins secreted by normal human osteoblasts from adult trabecular bone were identified by N-terminal sequencing to be gelatinase, osteonectin, the C-terminal propeptides of the alpha 1 and alpha 2 chains of type I collagen, tissue inhibitor of metalloproteinase 1 (TIMP-1), and beta 2-microglobulin. The amounts of each of these proteins secreted into medium over a 24 h interval did not change over the 7 consecutive days of culture under serum-free conditions, which indicates that this pattern of protein secretion is not significantly affected by the serum-free conditions needed for protein identification by this method. In addition, radioimmunoassay for bone gla protein (BGP), a marker for osteoblast phenotype, revealed that BGP secretion remained high over 7 days of culture under serum-free conditions and was comparable to the rate of BGP secretion in control cultures with 10% serum. The major proteins secreted by MG-63 cells were identified by N-terminal sequencing to be gelatinase, a novel 40 kD human bone protein we termed YKL-40, TIMP-1, the recently discovered TIMP-2, and beta 2-microglobulin. Further studies revealed that YKL-40 is the only protein detectable by Coomassie staining of SDS gels of MG-63 media proteins that is induced by extended time at confluence or by treatment with 1,25-(OH)2D3. The apparent absence of detectable Coomassie-stained bands corresponding to the C-terminal propeptides of collagen in the medium of MG-63 cells suggests that these transformed cells may not be a good model for bone matrix formation. The major proteins secreted by normal fetal osteoblastic cells were identified by N-terminal sequencing to be osteonectin and the C-terminal propeptides of the alpha 1 and alpha 2 chains of type I collagen. Gelatinase and TIMP could not be detected among the conditioned medium proteins by these methods. These observations indicate that fetal osteoblasts primarily express proteins that are matrix constituents and adult human osteoblasts secrete, in addition to these, proteins that could function in matrix turnover.

A new biochemical marker for joint injury. Analysis of YKL-40 in serum and synovial fluid

We report the development of the first radioimmunoassay for YKL-40, a M(r) = 40 kDa protein which is secreted at high levels by human synovial cells and articular cartilage chondrocytes, and by the human osteosarcoma cell line MG63. This assay uses YKL-40 purified from the conditioned medium of MG63 cells as standard and tracer, and as antigen for immunizing rabbits. With this assay we have discovered high levels of YKL-40 antigen in serum and SF. The molecular weight of serum and SF YKL-40 is identical to purified YKL-40. To evaluate the possible utility of YKL-40 in the assessment of joint disease, we measured YKL-40 in serum and SF of 49 patients with various forms of inflammatory and degenerative joint disease and in the serum of 50 normal adults. The YKL-40 level in serum was significantly higher (P < 0.001) in the patients compared to the normal adults, but there was no difference in serum YKL-40 between the patients with inflammatory joint diseases and OA. The SF levels of YKL-40 were 15-fold higher than serum levels and there was a significant correlation (r = 0.55, P < 0.001) between YKL-40 concentration in SF and serum. Although the tissue distribution of YKL-40 secretion is presently unknown, these observations suggest that a major portion of serum YKL-40 in fact arises from the joint.(ABSTRACT TRUNCATED AT 250 WORDS)

The JIL-1 tandem kinase mediates histone H3 phosphorylation and is required for maintenance of chromatin structure in Drosophila

To analyze the function of the chromosomal kinase JIL-1, we generated an allelic series of hypomorphic and null mutations. JIL-1 is an essential kinase for viability, and reduced levels of JIL-1 kinase activity lead to a global change in chromatin structure. In JIL-1 hypomorphs, euchromatic regions of polytene chromosomes are severely reduced and the chromosome arms condensed. This is correlated with decreased levels of histone H3 Ser10 phosphorylation. These levels can be restored by a JIL-1 transgene placing JIL-1 directly in the pathway mediating histone H3 phosphorylation. We propose a model where JIL-1 kinase activity is required for maintaining the structure of the more open chromatin regions that facilitate gene transcription.

Metabolomic NMR fingerprinting to identify and predict survival of patients with metastatic colorectal cancer

Earlier detection of patients with metastatic colorectal cancer (mCRC) might improve their treatment and survival outcomes. In this study, we used proton nuclear magnetic resonance ((1)H-NMR) to profile the serum metabolome in patients with mCRC and determine whether a disease signature may exist that is strong enough to predict overall survival (OS). In 153 patients with mCRC and 139 healthy subjects from three Danish hospitals, we profiled two independent sets of serum samples in a prospective phase II study. In the training set, (1)H-NMR metabolomic profiling could discriminate patients with mCRC from healthy subjects with a cross-validated accuracy of 100%. In the validation set, 96.7% of subjects were correctly classified. Patients from the training set with maximally divergent OS were chosen to construct an OS predictor. After validation, patients predicted to have short OS had significantly reduced survival (HR, 3.4; 95% confidence interval, 2.06-5.50; P = 1.33 × 10(-6)). A number of metabolites concurred with the (1)H-NMR fingerprint of mCRC, offering insights into mCRC metabolic pathways. Our findings establish that (1)H-NMR profiling of patient serum can provide a strong metabolomic signature of mCRC and that analysis of this signature may offer an independent tool to predict OS.

Serum YKL-40 and colorectal cancer

YKL-40 is a mammalian member of the chitinase protein family. Although the function of YKL-40 is unknown, the pattern of its expression suggests a function in remodelling or degradation of extracellular matrix. High serum YKL-40 has been found in patients with recurrent breast cancer and has been related to short survival. In the present study we analysed YKL-40 in preoperative sera from patients with colorectal cancer and evaluated its relation to survival. Serum YKL-40 was determined by RIA in 603 patients. Survival after operation was registered, and median follow-up time was 61 months. Three hundred and forty patients died. Sixteen per cent of the patients with Dukes' A, 26% with Dukes' B, 19% with Dukes' C and 39% with Dukes' D had high serum YKL-40 levels (adjusted for age). Analysis of serum YKL-40 as a continuous variable showed an association between increased serum YKL-40 and short survival (P < 0.0001). Patients with high preoperative serum YKL-40 concentration had significantly shorter survival than patients with normal YKL-40 (HR = 1.7; 95% CI: 1.3-2.1, P < 0.0001). Multivariate Cox analysis including serum YKL-40, serum CEA, Dukes' stage, age and gender showed that high YKL-40 was an independent prognostic variable for short survival (HR = 1.4; 95% CI: 1.1-1.8, P = 0.007). These results suggest that YKL-40 may play an important role in tumour invasion.

YKL-40, a biomarker of inflammation, is elevated in patients with type 2 diabetes and is related to insulin resistance

OBJECTIVE AND DESIGN

YKL-40 participates in inflammatory states and vascular processes, which implies that comparison can be made with other inflammatory markers associated with insulin resistance and type 2 diabetes (T2D). In the present study levels of plasma YKL-40 and serum hsCRP were evaluated in patients with T2D.

MATERIALS AND METHODS

Patients with T2D and age-matched healthy controls participated in the study. Insulin resistance was estimated using HOMA-IR model. Biochemical parameters were measured in venous blood after a 10 h fast.

RESULTS

Patients with T2D were insulin resistant (p<0.001) and had raised levels of plasma YKL-40 (p<0.001) and serum hsCRP (p<0.001). YKL-40 was correlated with HOMA-IR (r=0.23, p<0.01), NEFA (r=0.32, p<0.001) and triglycerides (r=0.24, p<0.05). YKL-40 and hsCRP were not correlated (r=0.17, p=NS). All participants with hsCRP<1 mg/l had higher insulin sensitivity (p<0.05 and p<0.01, respectively). HsCRP were predicted by HOMA-IR and BMI (r2=0.48, p<0.01). Plasma YKL-40 was predicted by HOMA-IR and triglycerides (r2=0.27, p<0.01).

CONCLUSIONS

YKL-40 and hsCRP are elevated in patients with T2D and are related to insulin resistance. No correlation was found between YKL-40 and hsCRP indicating that increased levels of YKL-40 occur independently from elevated plasma hsCRP.

The effect of a gonadotropin-releasing hormone agonist analog (nafarelin) on bone metabolism

The effect on bone metabolism of an agonist analog of GnRH, nafarelin, was studied in 16 premenopausal women, who received 200 micrograms nafarelin/day for 6 months, and 9 premenopausal women, who received 400 micrograms nafarelin/day for 6 months, followed by a 6-month follow-up period. Bone mineral content in the forearm (measured by single photon absorptiometry) and in the spine (measured by dual photon absorptiometry) significantly decreased after 6 months of treatment with 400 micrograms nafarelin, but 6 months after termination of treatment all bone mineral measurements had returned to pretreatment levels. The bone mineral measurements in the 200 micrograms group did not change throughout the study. In both treatment groups the biochemical estimates of bone turnover increased significantly to postmenopausal levels. Withdrawal of treatment resulted in an abrupt decrease in the bone resorption parameters (fasting urinary hydroxyproline to creatinine and calcium to creatinine excretion ratios and serum phosphate), whereas there was a protracted fall in the bone formation parameters (plasma bone Gla protein and serum alkaline phosphatase) 6 months after termination of treatment. Our findings demonstrate that nafarelin in both doses increased biochemical indices of bone turnover, that 400 micrograms/day nafarelin resulted in a significant decrease in bone mineral content, and that these effects were reversible.

Serum YKL-40 concentrations in patients with rheumatoid arthritis: relation to disease activity

OBJECTIVE

YKL-40, also called human cartilage glycoprotein-39, is secreted by chondrocytes, synovial cells, macrophages and neutrophils. Studies have shown that YKL-40 is an autoantigen in rheumatoid arthritis (RA). We evaluated whether serum YKL-40 was related to disease activity in patients with RA.

METHODS

Serum YKL-40 was determined by radioimmunoassay in 156 patients with RA during a 1 yr longitudinal study.

RESULTS

Serum YKL-40 was increased in 54% of the patients with clinically active disease. Patients with clinically active disease initially who became inactive after 12 months had a significant decrease in serum YKL-40 (-30%, P < 0.002) and patients who changed from inactive to active disease had an increase in serum YKL-40. Patients who remained active had unchanged serum YKL-40 during the study. Serum YKL-40 decreased rapidly (-24% after 7 days, P < 0.01) during prednisolone therapy, and more slowly in patients treated with methotrexate only (-15% after 60 days, P < 0.01). Patients with early RA (disease duration < 3 yr, n = 50) and a persistently elevated serum YKL-40 were at risk of radiological disease progression as determined by Larsen score.

CONCLUSION

Serum YKL-40 varies according to disease activity in RA, but provides in some respect information different from conventional markers. Our previous studies are consistent with a local release of YKL-40 in the arthritic joint followed by a secondary increase in serum YKL-40. YKL-40 may prove to be a new tool for the study of disease activity and pathophysiology of RA.

Nasal calcitonin for treatment of established osteoporosis

Thirty-seven women with established osteoporosis completed a one-year double-blind, placebo-controlled study with the primary aim of examining the effect of nasal salmon calcitonin (200 IU daily) on bone and calcium metabolism. All the women received a daily calcium supplement of 500 mg. For comparison we also report data from an age-matched group of healthy women who did not receive calcium supplementation. The bone mineral measured in the forearm (single photon absorptiometry) and spine (dual photon absorptiometry) showed a similar pattern during treatment. The calcitonin group (n = 17) did not lose bone mineral in comparison with the placebo (n = 20) and the control groups (n = 19) (P less than 0.01). The biochemical estimates of both bone resorption and bone formation decreased highly significantly in the calcitonin group (P less than 0.001) and were unchanged in the control group, whereas the placebo (calcium) group showed intermediate values. Neither subjective nor objective side-effects occurred in any of the groups. We conclude that nasal calcitonin is a realistic treatment of established osteoporosis.

JIL-1: a novel chromosomal tandem kinase implicated in transcriptional regulation in Drosophila

We have cloned and characterized JIL-1, a novel tandem kinase in Drosophila that associates with the chromosomes throughout the cell cycle. Antibody staining and live imaging of JIL-1-GFP transgenic flies show that JIL-1 localizes to the gene-rich interband regions of larval polytene chromosomes and is upregulated almost 2-fold on the hypertranscribed male X chromosome compared to autosomes. Phylogenetic analysis suggests that JIL-1 together with human MSKs defines a separate family of tandem kinases. That JIL-1 is a functional kinase was demonstrated by autophosphorylation and phosphorylation of histone H3 in vitro. Based on these findings, we propose that JIL-1 may play a role in transcriptional control potentially by regulating chromatin structure.

Relationship between the in vitro radiosensitivity of skin fibroblasts and the expression of subcutaneous fibrosis, telangiectasia, and skin erythema after radiotherapy

OBJECTIVE

To investigate if the occurrence of subcutaneous fibrosis after radiotherapy in an unselected group of breast cancer patients is related to cellular radiosensitivity of skin fibroblasts as measured in a clonogenic assay.

MATERIALS AND METHODS

An in vitro colony-forming assay of normal fibroblast radiosensitivity was applied to primary skin biopsies from 31 breast cancer patients who received post-mastectomy radiotherapy with large doses per fraction (2.7-3.9 Gy) more than 10 years earlier. Three clinical normal-tissue endpoints were assessed. Two late endpoints, subcutaneous fibrosis and telangiectasia, were evaluated in three treatment fields by a single experienced clinician. In addition, skin erythema had been assessed at the end of treatment by members of the staff and junior staff. From previous analyses of normal tissue response, individual clinical radiosensitivity could be assessed as "excess risk' of each of the three reactions. This was defined as the difference between the actual observed response in the patient and the expected response estimated from individual treatment characteristics in a linear quadratic (LQ) mixture model and, for the two late endpoints, with correction for the follow-up time. This clinical radioresponsiveness was compared with the in vitro radiosensitivity of the skin fibroblasts. To this end, the fractions of colony-forming cells after graded single doses were fitted by an LQ survival curve using non-linear regression from which the surviving fraction at 3.5 Gy (SF3.5) was estimated. Assessment at 3.5 Gy was chosen to reflect the fraction size during clinical radiotherapy.

RESULTS

A statistically significant variability of in vitro radiosensitivity between patients could be detected for both SF2 (P = 0.0095) and SF3.5 (P = 0.0008). A significant correlation was observed between SF3.5 and excess risk of fibrosis (rs = -0.46, P = 0.009) while no association was found between fibroblast radiosensitivity and either the occurrence of severe skin telangiectasia or the acute endpoint skin erythema.

CONCLUSION

These results suggest that variability in the occurrence of subcutaneous fibrosis, but not telangiectasia or erythema, after radiotherapy is partly accounted for by differences in cellular radiosensitivity of normal skin fibroblasts.

Plasma YKL-40: a potential new cancer biomarker?

YKL-40, a 40-kDa secreted glycoprotein, with its gene located on chromosome 1q32.1, is produced by cancer cells and inflammatory cells and has a role in inflammation, cell proliferation, differentiation, protection against apoptosis, stimulation of angiogenesis and regulation of extracellular tissue remodeling. Plasma levels of YKL-40 are elevated in a subgroup of patients with primary or advanced cancer compared with age-matched healthy subjects, but also in patients with many different diseases characterized by inflammation. Elevated plasma YKL-40 levels are an independent prognostic biomarker of short survival. There is still insufficient evidence to support its value outside of clinical trials as a screening tool, prognosticator of survival, predictor of treatment response and as a monitoring tool in the routine management of individual patients with cancer or diseases characterized by inflammation. Large prospective, longitudinal clinical cancer studies are needed to determine if plasma YKL-40 is a new cancer biomarker, or is mainly a biomarker of inflammation.

Is there more than one late radiation proctitis syndrome?

PURPOSE

To investigate the significance of the various late rectal symptoms that appear after radical prostatic irradiation.

PATIENTS AND METHODS

Patients with localised prostate cancer treated between 1987 and 1994 at the Mater Hospital, Newcastle with radical megavoltage irradiation were recalled for examination and to complete a detailed questionnaire concerning late radiation-induced symptoms and their effects on normal daily life. The influence of patient age treatment related variables and acute proctitis symptoms occurring during therapy or the late symptoms recorded were assessed and the relationship between late symptoms and late EORTC/RTOG score and impact on normal daily life were studied.

RESULTS

The presence of symptoms of acute proctitis was the only factor to predict any of three late symptoms (urgency, frequency and diarrhoea) and late EORTC/RTOG score in this series (odds ratios: 1.7-2.57, P-values: 0.009-0.0007). Cluster and discriminant function analyses revealed the presence of five subgroups of patients with varying permutations of different late rectal symptoms, including one group with minimal symptoms (P < 0.0001). While bleeding and rectal discharge were the major contributors to late EORTC/RTOG score (P < 0.0001 and 0.04), faecal urgency and bleeding were the most important factors to impact on normal daily life (P < 0.0001 and P < 0.0003). A relatively low concordance was found between late EORTC/RTOG score and the patients' self assessment on the effect of their symptoms on their normal daily lives. Some late symptoms, including bleeding and rectal discharge become less prevalent after 3 years of follow-up with a resulting improvement in EORTC/RTOG score.

CONCLUSIONS

There may be more than one late (chronic) proctitis syndrome which may be linked in greater or lesser degrees to acute proctitis symptoms occurring during therapy. Urgency is a common late symptom which often has an important impact on normal daily life and deserves recognition in late normal tissue scoring systems. Assessment of the incidence of bleeding as a measure of late rectal morbidity following prostate irradiation may underestimate the impact of these chronic effects. Confirmatory studies are necessary.

Do acute mucosal reactions lead to consequential late reactions in patients with head and neck cancer?

BACKGROUND AND PURPOSE

The relationship between acute and late mucosal reactions remains ill defined but is of considerable relevance to efforts to produce therapeutic gains through the use of altered fractionation schemes and concurrent chemotherapy. We therefore investigated whether acute mucosal reactions in patients treated with an accelerated and a conventionally fractionated radiotherapy regime predicted the severity of late mucosal reactions.

PATIENTS AND METHODS

The study population consisted of 191 patients randomised on a prospective trial comparing conventional fractionation at 2 Gy/fraction per day, 70 Gy over 47 days with an accelerated regimen of 59.4 Gy, 1.8 Gy b.i.d over 24 days for Stage III-IV carcinoma of the head and neck. Acute and late mucosal reactions were scored according to RTOG/EORTC criteria and analyzed using multiple regression techniques.

RESULTS

The duration of time spent by patients at the acute confluent mucositis grade 3 level was inversely related to the time to onset of the reaction for both fractionation schedules. Time to onset was more rapid for patients treated on the accelerated schedule but time spent at the reaction grade did not differ significantly between the schedules. After correction for treatment and patient related factors, anatomical site (oral cavity/oropharynx versus hypopharynx/larynx) and increasing duration of confluent mucositis emerged as independent predictors of the hazard of late mucosal reactions with the latter effect being more pronounced in the accelerated treatment arm. The expected reduction in late mucosal effects in the accelerated fractionation arm, predicted by the LQ model for late effects was identified only in patients whose acute confluent mucosal reactions lasted less than 20 days.

CONCLUSIONS

The presence of individual patient susceptibility factors that determine the severity of acute mucosal reactions is suggested. A link between severe and prolonged acute reactions and the risk of developing late mucosal reactions that is independent of biological dose, has also been found. Purpose designed prospective studies of these issues are necessary.

Studies on YKL-40 in knee joints of patients with rheumatoid arthritis and osteoarthritis. Involvement of YKL-40 in the joint pathology

OBJECTIVE

The presence of YKL-40 (human cartilage glycoprotein 39) in synovium, cartilage and synovial fluid (SF) from knee joints of patients with rheumatoid arthritis and osteoarthritis (OA) were related to histopathological changes in synovium and cartilage and to serum YKL-40 and other biochemical markers.

METHODS

The localization of YKL-40 in synovium and cartilage was determined by immunohistochemistry. Synovial inflammation was estimated histologically and by magnetic resonance imaging (MRI). Biochemical markers of inflammation, neutrophil activation and cartilage metabolism were analysed. YKL-40 concentrations in serum and SF were determined by RIA and ELISA.

RESULTS

In the synovium YKL-40 positive cells were found in lining and stromal cells (macrophages) and the number of YKL-40 positive cells was related to the degree of synovitis. In arthritic cartilage, YKL-40 was located to chondrocytes. YKL-40 levels in SF were higher in RA patients with moderate/severe or none/slight synovitis of the knee joint compared to OA patients with moderate/severe or none/slight synovitis. SF YKL-40 correlated with the synovial membrane and the joint effusion volumes determined by magnetic resonance imaging (MRI) and with other biochemical markers of intercellular matrix metabolism. SF YKL-40 was higher than serum YKL-40, and a relationship existed between the YKL-40 levels in SF and serum. Intraarticular glucocorticoid injection was followed by clinical remission and a decrease in serum YKL-40, which increased again at clinical relapse.

CONCLUSIONS

YKL-40 in SF is derived from cells in the inflamed synovium, chondrocytes and SF neutrophils. Joint derived YKL-40 influences serum YKL-40. YKL-40 may be involved in the pathophysiology of the arthritic processes and reflect local disease activity.

Serum YKL-40, a potential new marker of disease activity in patients with inflammatory bowel disease

BACKGROUND

YKL-40 is secreted by macrophages and neutrophils and is a growth factor for vascular endothelial cells and fibroblasts. Elevated serum concentrations of YKL-40 are found in patients with diseases characterized by inflammation or ongoing fibrosis. The aim of this study was to seek association between serum YKL-40 in patients with ulcerative colitis (UC) and Crohn disease (CD) and clinical disease activity.

METHODS

One-hundred-and-sixty-four patients with UC and 173 patients with CD were studied. The Simple Clinical Colitis Activity Index (SCCAI) and the Harvey-Bradshaw (H-B) score were used to assess disease activity. Serum YKL-40 (determined by ELISA) was related to C-reactive protein (CRP) and disease activity.

RESULTS

In patients with UC, the median serum YKL-40 rose with increasing disease activity, and patients with severe active disease had higher serum YKL-40 (median 59 microg/L (95% CI: 26-258 microg/L), P < 0.001) than patients with inactive UC (33 microg/L (19-163)) and age-matched controls (43 microg/L (20-124)). Patients with severe active CD had higher serum YKL-40 (59 microg/L (21-654), P < 0.001) than age-matched controls, but not higher than inactive CD patients (43 microg/L (17-306)). Serum YKL-40 was elevated in 41% of the patients with severe UC, in 10% with inactive UC, in 46% with severe CD and in 30% with inactive CD. Serum YKL-40 correlated with SCCAI in UC patients but not with H-B score in CD patients. In both patient groups, low correlations were found between serum YKL-40 and CRP, albumin and leucocytes.

CONCLUSIONS

Serum YKL-40 is elevated in patients with active IBD and may be complementary to inflammatory markers and clinical characteristics in the assessment of disease activity.

Plasma YKL-40: a BMI-independent marker of type 2 diabetes

OBJECTIVE

YKL-40 is produced by macrophages, and plasma YKL-40 is elevated in patients with diseases characterized by inflammation. In the present study, YKL-40 was examined in relation to obesity, inflammation, and type 2 diabetes.

RESEARCH DESIGN AND METHODS

Plasma YKL-40 and adipose tissue YKL-40 mRNA levels were investigated in 199 subjects who were divided into four groups depending on the presence or absence of type 2 diabetes and obesity. In addition, plasma YKL-40 was examined in healthy subjects during a hyperglycemic clamp, in which the plasma glucose level was kept at 15 mmol/l for 3 h, and during a hyperinsulinemic-euglycemic clamp.

RESULTS

Patients with type 2 diabetes had higher plasma YKL-40 (76.7 vs. 45.1 ng/ml, P = 0.0001) but not higher expression in adipose tissue YKL-40 mRNA (1.20 vs. 0.98, P = 0.2) compared with subjects with a normal glucose tolerance. Within the groups with normal glucose tolerance and type 2 diabetes, obesity subgroups showed no difference with respect to either plasma YKL-40 or adipose tissue YKL-40 mRNA levels. Multivariate regression analysis showed that plasma YKL-40 was associated with fasting plasma glucose (beta = 0.5, P = 0.0014) and plasma interleukin (IL)-6 (beta = 0.2, P = 0.0303). Plasma YKL-40 was not related to parameters of obesity. There were no changes in plasma YKL-40 in healthy subjects during either hyperglycemic or hyperinsulinemic-euglycemic clamps.

CONCLUSIONS

Plasma YKL-40 was identified as an obesity-independent marker of type 2 diabetes related to fasting plasma glucose and plasma IL-6 levels.

Serum bone Gla-protein as a marker of bone growth in children and adolescents: correlation with age, height, serum insulin-like growth factor I, and serum testosterone

Serum bone Gla-protein (BGP) was determined by RIA in 450 normal children (229 girls and 221 boys, aged 6-19 yr). Serum BGP concentrations changed in relation to age and sex with a pattern that resembles the height velocity curves for children. The increase in serum BGP occurred at the expected age of the growth spurt in both sexes, and the peak values occurred at the age of 12 yr in girls [mean, 49.2 +/- 5.6 (+/- SE) micrograms/L] and 14 yr in boys (64.0 +/- 6.3 micrograms/L). In the boys aged 10-14 yr and in the girls aged 9-12 yr, serum BGP correlated significantly with serum insulin-like growth factor I (IGF-I), serum testosterone, age and height. When the interrelationship was analyzed by means of partial correlation, with age held constant, serum BGP still correlated significantly with the other parameters, but when height was fixed there was only a correlation with serum IGF-I. In children with untreated central precocious puberty, the mean serum BGP concentration was significantly higher than in age-matched normal children [mean, 61.4 +/- 31.7 (+/- SD) vs. 29.0 +/- 10.3 micrograms/L; P less than 0.001]. Serum BGP values decreased significantly in these patients during 1 yr of treatment with a LHRH analog (buserelin) and cyproterone acetate. We conclude that serum BGP is a sensitive marker of bone growth in normal children and in children with increased growth velocity. Repeated measurements may provide useful information in the diagnosis and treatment of children with disturbances in bone turnover.