Whole blood long-chain n-3 fatty acids as a measure of fish oil compliance in children with acute lymphoblastic leukemia: a pilot study.

Long-chain n-3 fatty acids (n-3 LCPUFA) may prevent chemotherapy-induced hyperlipidemia in children with acute lymphoblastic leukemia (ALL). However, compliance could be a problem and intake-biomarker correlations may be affected by bodyweight and blood transfusions. We assessed whole blood n-3 LCPUFA three times during the first 83 days of treatment in six 1-17-year-old children with ALL, who received 2.4-4.9 g/d n-3 LCPUFA depending on bodyweight. Mean compliance was 73%, which resulted in a 2.5-fold increase in blood n-3 LCPUFA irrespective of blood transfusions. The correlation between relative blood content of n-3 LCPUFA and intake in g/d across the study period was strong (r=0.76, p=0.001). When n-3 LCPUFA was expressed in absolute concentrations and intake per kg bodyweight the correlation decreased (r=0.39, p=0.164) and was driven by baseline values. Thus, relative content of n-3 LCPUFA in blood reflects fish oil compliance in children with ALL despite blood transfusions and differences in bodyweight.

T-cell acute lymphoblastic leukemia in patients 1-45 years treated with the pediatric NOPHO ALL2008 protocol.

The NOPHO ALL2008 is a population-based study using an unmodified pediatric protocol in patients 1-45 years of age with acute lymphoblastic leukemia. Patients with T-ALL were given a traditional pediatric scheme if fast responding (minimal residual disease (MRD) < 0.1% day 29), or intensive block-based chemotherapy if slow responding (MRD > 0.1% day 29). Both treatment arms included pediatric doses of high-dose methotrexate and asparaginase. If MRD ≥ 5% on day 29 or ≥0.1% after consolidation, patients were assigned to allogeneic hematopoietic stem cell transplantation. The 5-year overall survival of the 278 T-ALL patients was 0.75 (95% CI 0.69-0.81), being 0.82 (0.74-0.88) for patients 1.0-9.9 years, 0.76 (0.66-0.86) for those 10.0-17.9 years, and 0.65 (0.55-0.75) for the older patients. The risk of death in first remission was significantly higher in adults (12%) compared with the 1-9 years group (4%). The MRD responses in the three age groups were similar, and only a nonsignificant increase in relapse risk was found in adults. In conclusion, an unmodified pediatric protocol in patients 1-45 years is effective in all age groups. The traditional pediatric treatment schedule was safe for all patients, but the intensive block therapy led to a high toxic death rate in adults.

The plasminogen activator inhibitor PAI-1 controls in vivo tumor vascularization by interaction with proteases, not vitronectin. Implications for antiangiogenic strategies.

The plasminogen (Plg)/plasminogen activator (PA) system plays a key role in cancer progression, presumably via mediating extracellular matrix degradation and tumor cell migration. Consequently, urokinase-type PA (uPA)/plasmin antagonists are currently being developed for suppression of tumor growth and angiogenesis. Paradoxically, however, high levels of PA inhibitor 1 (PAI-1) are predictive of a poor prognosis for survival of patients with cancer. We demonstrated previously that PAI-1 promoted tumor angiogenesis, but by an unresolved mechanism. We anticipated that PAI-1 facilitated endothelial cell migration via its known interaction with vitronectin (VN) and integrins. However, using adenoviral gene transfer of PAI-1 mutants, we observed that PAI-1 promoted tumor angiogenesis, not by interacting with VN, but rather by inhibiting proteolytic activity, suggesting that excessive plasmin proteolysis prevents assembly of tumor vessels. Single deficiency of uPA, tissue-type PA (tPA), uPA receptor, or VN, as well as combined deficiencies of uPA and tPA did not impair tumor angiogenesis, whereas lack of Plg reduced it. Overall, these data indicate that plasmin proteolysis, even though essential, must be tightly controlled during tumor angiogenesis, probably to allow vessel stabilization and maturation. These data provide insights into the clinical paradox whereby PAI-1 promotes tumor progression and warrant against the uncontrolled use of uPA/plasmin antagonists as tumor angiogenesis inhibitors.

Results of NOPHO ALL2008 treatment for patients aged 1-45 years with acute lymphoblastic leukemia.

Adults with acute lymphoblastic leukemia (ALL) do worse than children. From 7/2008 to 12/2014, Nordic and Baltic centers treated 1509 consecutive patients aged 1-45 years with Philadelphia chromosome-negative ALL according to the NOPHO ALL2008 without cranial irradiation. Overall, 1022 patients were of age 1-9 years (A), 266 were 10-17 years (B) and 221 were 18-45 years (C). Sixteen patients (three adults) died during induction. All others achieved remission after induction or 1-3 intensive blocks. Subsequently, 45 patients (12 adults) died, 122 patients relapsed (32 adults) with a median time to relapse of 1.6 years and 13 (no adult) developed a second malignancy. Median follow-up time was 4.6 years. Among the three age groups, older patients more often had higher risk ALL due to T-ALL (32%/25%/9%, P<0.001), KMT2A rearrangements (6%/5%/3%, P<0.001) and higher day 29 residual leukemia for B-lineage (P<0.001), but not T-ALL (P=0.53). Event-free survival rates (pEFS5y) were 89±1% (A), 80±3% (B) and 74±4% (C) with significant differences only for non-high risk groups. Except for thrombosis, pancreatitis and osteonecrosis, the risk of 19 specified toxicities was not enhanced by age above 10 years. In conclusion, a pediatric-based protocol is tolerable and effective for young adults, despite their increased frequency of higher risk features.

Asparaginase-associated pancreatitis: a study on phenotype and genotype in the NOPHO ALL2008 protocol.

Asparaginase (ASP)-associated pancreatitis (AAP) occurs during acute lymphoblastic leukemia treatment. Among 1285 children (1.0-17.9 years) diagnosed during July 2008-December 2014 and treated according to the Nordic/Baltic ALL2008 protocol, 86 (cumulative incidence=6.8%) developed AAP. Seventy-three cases were severe (diagnostic AAP criteria persisting >72 h) and 13 mild. Cases were older than controls (median: 6.5 vs 4.5 years; P=0.001). Pseudocysts developed in 28%. Of the 20 re-exposed to ASP, 9 (45%) developed a second AAP. After a median follow-up of 2.3 years, 8% needed permanent insulin therapy, and 7% had recurrent abdominal pain. Germline DNA on 62 cases and 638 controls was genotyped on Omni2.5exome-8-v1.2 BeadChip arrays. Overall, the ULK2 variant rs281366 showed the strongest association with AAP (P=5.8 × 10-7; odds ratio (OR)=6.7). Cases with the rs281366 variant were younger (4.3 vs 8 years; P=0.015) and had lower risk of AAP-related complications (15% vs 43%; P=0.13) compared with cases without this variant. Among 45 cases and 517 controls <10 years, the strongest associations with AAP were found for RGS6 variant rs17179470 (P=9.8 × 10-9; OR=7.3). Rs281366 is located in the ULK2 gene involved in autophagy, and RGS6 regulates G-protein signaling regulating cell dynamics. More than 50% of AAP cases <10 years carried one or both risk alleles.

Direct evidence of the importance of stromal urokinase plasminogen activator (uPA) in the growth of an experimental human breast cancer using a combined uPA gene-disrupted and immunodeficient xenograft model.

Several studies have indicated an interaction between tumor cells and infiltrating stromal cells regarding the urokinase plasminogen activation (uPA) system. By developing combined uPA gene-disrupted and immunodeficient mice, we have studied the role of stromal uPA for the growth of the MDA-MB-435 BAG human tumor xenograft. Subcutaneous tumor growth and lung metastasis were compared between wild-type immunodeficient mice and mice with the combined deficiencies. Tumor growth was evaluated by volume measurements and plasma beta-galactosidase activity and metastasis was evaluated by counting lung surface metastases. Although no differences appeared in primary tumor take between the two groups of mice, a significant difference was observed in primary tumor growth, with tumors in uPA-/- mice growing significantly more slowly. In addition, a nonsignificant trend toward fewer lung metastases in uPA-/- mice was observed. The present data points to a critical role of stromal-derived uPA in the primary tumor growth of MDA-MB-435 BAG xenografts, whereas only a trend toward fewer lung metastases in uPA gene-disrupted mice was found.

MCF7/LCC2: a 4-hydroxytamoxifen resistant human breast cancer variant that retains sensitivity to the steroidal antiestrogen ICI 182,780.

The development of resistance to the antiestrogen tamoxifen occurs in a high percentage of initially responsive patients. We have developed a new model in which to investigate acquired resistance to triphenylethylenes. A stepwise in vitro selection of the hormone-independent human breast cancer variant MCF-7/LCC1 against 4-hydroxytamoxifen produced a stable resistant population designated MCF7/LCC2. MCF7/LCC2 cells retain levels of estrogen receptor expression comparable to the parental MCF7/LCC1 and MCF-7 cells. Progesterone receptor expression remains estrogen inducible in MCF7/LCC2 cells, although to levels significantly lower than observed in MCF-7 and MCF7/LCC1 cells. MCF7/LCC2 cells form tumors in ovariectomized nude mice without estrogen supplementation, and these tumors are tamoxifen resistant but can be estrogen stimulated. Significantly, MCF7/LCC2 cells have retained sensitivity to the steroidal antiestrogen ICI 182,780. These data suggest that some breast cancer patients who acquire resistance to tamoxifen may not develop cross-resistance to treatment with steroidal antiestrogens.

1 alpha,25-Dihydroxyvitamin D3 inhibits the invasive potential of human breast cancer cells in vitro.

Using the Boyden chamber invasion assay, the effect of 1 alpha,25-dihydroxyvitamin D3 [1 apha,25(OH)2D3] on the invasiveness of the highly invasive, oestrogen receptor-negative human breast cancer cell line MDA-MB-231 was examined. The MDA-MB-231 cells were shown to contain high-affinity receptors for 1 alpha,25(OH)2D3 with a Kd of 1.5 x 10(-11) M. When the cells were treated with 1 alpha,25(OH)2D3 for 4 days before the assay was performed, a dose-dependent inhibition of their invasive potential was demonstrated. Fifty per cent inhibition of invasion was obtained with a concentration of 13 pM of 1 alpha,25(OH)2D3. However, when the cells were treated for only 6 h during the assay, no inhibitory effect was seen. The process of migration was also affected by treatment with 1 alpha,25(OH)2D3 for 4 days, although the inhibition was not of the same magnitude as seen for the invasion. Fifty per cent inhibition of migration occurred at a concentration of 3.2 nM of 1 alpha,25(OH)2D3 (250 times higher than in the invasion assay). Inhibition of invasion and migration was not due to the known anti-proliferative effect of 1 alpha,25(OH)2D3, as no growth reduction could be demonstrated with treatment up to 5 days. Based on the present investigation it can therefore be concluded that 1 alpha,25(OH)2D3 is able to inhibit tumour cell invasiveness by a mechanism which is not exclusively based on its anti-proliferative and anti-migrative effects.

Effect of NCAM-transfection on growth and invasion of a human cancer cell line.

A cDNA encoding the human transmembrane 140 kDa isoform of the neural cell adhesion molecule (NCAM) was transfected into the highly invasive MDA-MB-231 human breast cancer cell line. Transfectants with a homogeneous expression of NCAM showed a restricted capacity for penetration of an artificial basement membrane. However, when injected into nude mice, both control and NCAM-expressing cell lines produced equally invasive tumors. Tumors generated from NCAM-transfected cells were heterogeneous, containing NCAM-positive as well as NCAM-negative areas, indicating the existence of host factors capable of modulating NCAM expression in vivo. In nude mice, NCAM-transfected cells developed tumors with longer latency periods and slower growth rates than tumors induced by NCAM-negative control cells, implying that NCAM may be involved not only in adhesive and motile behavior of tumor cells but also in their growth regulation. There was no indication of differences in cell proliferative characteristics between the different NCAM-transfected and the control transfected cells as determined by flow cytometric DNA analysis, suggesting an increased cell loss as the reason for decreased in vivo growth rate of the NCAM-transfected cells. The fact that NCAM expression influences growth regulation attributes a pivotal role to this cell adhesion molecule during ontogenesis and tumor development.

Hormone resistance, invasiveness, and metastatic potential in breast cancer.

Critical phenotypic changes that occur during the progression of breast cancer include the loss of hormone-dependence, acquired resistance to systemic therapies, and increased metastatic potential. We have isolated a series of MCF-7 human breast cancer variants which exhibit hormone-independent growth, antiestrogen resistance, and increased metastatic potential. Analysis of the phenotypes of these variants strongly suggests that changes in the expression of specific genes may be critical to the generation of phenotypic diversity in the process of malignant progression in breast cancer. Epigenetic changes may contribute significantly to the generation of these phenotypic changes observed during breast cancer progression. Many of the characteristics of the progressed phenotypes appear to have arisen in response to appropriate selective pressures (growth in ovariectomized nude mice; growth in the presence of antiestrogens). These observations are consistent with the concept of clonal selection and expansion in the process of malignant progression.

Molecular and cellular analysis of basement membrane invasion by human breast cancer cells in Matrigel-based in vitro assays.

In vitro analyses of basement membrane invasiveness employing Matrigel (a murine tumor extract rich in basement membrane components) have been performed on human breast cancer model systems. Constitutive invasiveness of different human breast cancer (HBC) cell lines has been examined as well as regulation by steroid hormones, growth factors, and oncogenes. Carcinoma cells exhibiting a mesenchymal-like phenotype (vimentin expression, lack of cell border associated uvomorulin) show dramatically increased motility, invasiveness, and metastatic potential in nude mice. These findings support the hypothesis that epithelial to mesenchymal transition (EMT)-like events may be instrumental in the metastatic progression of human breast cancer. The MCF-7 subline MCF-7ADR appears to have undergone such a transition. The importance of such a transition may be reflected in the emergence of vimentin expression as an indicator of poor prognosis in HBC. Matrix degradation and laminin recognition are highlighted as potential targets for antimetastatic therapy, and analyses of laminin attachment and the matrix metalloproteinase (MMP) family in HBC cell lines are summarized. Matrigel-based assays have proved useful in the study of the molecular mechanisms of basement membrane invasiveness, their regulation in HBC cells, and their potential as targets for antimetastatic therapy.

Functional overlap between two classes of matrix-degrading proteases in wound healing.

Retarded wound healing was found in mice deficient in the serine protease precursor plasminogen, as well as in wild-type mice treated with the metalloprotease inhibitor galardin, but in both cases wound closure was ultimately completed in all mice within 60 days. The expression of several matrix metalloproteases in keratinocytes migrating to cover the wound was strongly enhanced by galardin treatment. However, when plasminogen-deficient mice were treated with galardin, healing was completely arrested and wound closure was not seen during an observation period of 100 days, demonstrating that protease activity is essential for skin wound healing. The requirement for both plasminogen deficiency and metalloprotease inhibition for complete inhibition of the healing process indicates that there is a functional overlap between the two classes of matrix-degrading proteases, probably in the dissection of the fibrin-rich provisional matrix by migrating keratinocytes. Each class alone is capable of maintaining sufficient keratinocyte migration to regenerate the epidermal surface, although this function would normally be performed by both classes acting in parallel. Since there are strong similarities between the proteolytic mechanisms in wound healing and cancer invasion, these results predict that complete arrest of this latter process in therapeutic settings will require the use of inhibitors of both classes of proteases.

A precise and efficient stereological method for determining murine lung metastasis volumes.

We have developed a computer-assisted stereological method based on unbiased principles for estimating metastasis volumes in mouse lungs. We evaluated this method using the transplantable Lewis lung carcinoma. Twenty-one days after subcutaneous inoculation of 10(6) Lewis lung cells into C57BL/6J mice, the mice had primary tumors with an average volume of 2300 mm(3). After perfusion fixation, the lungs were removed, embedded in OCT compound, snap-frozen, and processed for stereology. The metastasis volumes were estimated by application of the Cavalieri principle after evaluation of single sections from several evenly distributed tissue levels. The metastasis volume in a group of nine mice varied between 0.01 and 14.4 mm(3), with an average of 6.1 mm(3). The coefficient of variation was 0.9. The coefficient of error of the volume estimation was determined in five cases and varied from 0.08 to 0.23. Thus, the variation on the metastasis volumes that is achieved by this method contributes very little, 2.5%, to the total variance within the group of mice. In conclusion, we have developed an efficient and unbiased method to determine the metastasis burden in mouse lungs.

Increased stromal expression of murine urokinase plasminogen activator in a human breast cancer xenograft model following treatment with the matrix metalloprotease inhibitor, batimastat.

The matrix metalloprotease (MMP) family of enzymes and the urokinase plasminogen activator (uPA) pathway have both been implicated in tumor invasion and metastasis and in poor prognosis of cancer. We have previously shown that treatment with batimastat, a synthetic MMP inhibitor, leads to significant retardation but not regression of tumor growth in a human breast cancer xenograft model. In addition, batimastat treatment did not inhibit local tumor invasion, nor did it encourage stromal encapsulation of the tumor, suggesting the additional involvement of non-MMP proteolytic mechanisms. To investigate the presence of an alternative extracellular matrix protease whose activity is known to be important in breast cancer, but which is not inhibited by batimastat, expression of murine and human uPA were examined by in situ hybridization and ELISA. No differences were observed between untreated and batimastat-treated tumors regarding human uPA mRNA and protein. In contrast, murine uPA mRNA expression was increased at the tumor-stromal junction in batimastat-treated tumors in comparison with the control tumors. In agreement with these results, batimastat treatment was shown to significantly induce murine uPA protein content in the tumors. Inoculating MDA435/LCC-6 cells into immunodeficient, uPA-deficient mice resulted in tumor growth retardation as compared to tumor growth in littermate wild-type controls, while addition of batimastat treatment to uPA-/- mice did not result in further growth inhibition. The increased expression of stromal uPA may represent a cellular response to MMP inhibition and may demonstrate a new level of plasticity in the malignant progression of the disease. These results may have important implications for the clinical applications of MMP inhibitors, as well as for development of other anti-invasion drugs.