The aim of this study is to investigate whether reliable and accurate 3D geometrical models of the murine aortic arch can be constructed from sparse-view data in vivo micro-CT acquisitions. This would considerably reduce acquisition time and X-ray dose. In vivo contrast-enhanced micro-CT datasets were reconstructed using a conventional filtered back projection algorithm (FDK), the image space reconstruction algorithm (ISRA) and total variation regularized ISRA (ISRA-TV). The reconstructed images were then semi-automatically segmented. Segmentations of high- and low-dose protocols were compared and evaluated based on voxel classification, 3D model diameters and centerline differences. FDK reconstruction does not lead to accurate segmentation in the case of low-view acquisitions. ISRA manages accurate segmentation with 1024 or more projection views. ISRA-TV needs a minimum of 256 views. These results indicate that accurate vascular models can be obtained from micro-CT scans with 8 times less X-ray dose and acquisition time, as long as regularized iterative reconstruction is used.
A growing number of DNA transacting proteins is found in the nucleus and in mitochondria, including the DNA repair and replication protein Flap endonuclease 1, FEN1. Here we show a truncated FEN1 isoform is generated by alternative translation initiation, exposing a mitochondrial targeting signal. The shortened form of FEN1, which we term FENMIT, localizes to mitochondria, based on import into isolated organelles, immunocytochemistry and subcellular fractionation. In vitro FENMIT binds to flap structures containing a 5′ RNA flap, and prefers such substrates to single-stranded RNA. FENMIT can also bind to R-loops, and to a lesser extent to D-loops. Exposing human cells to ethidium bromide results in the generation of RNA/DNA hybrids near the origin of mitochondrial DNA replication. FENMIT is recruited to the DNA under these conditions, and is released by RNase treatment. Moreover, high levels of recombinant FENMIT expression inhibit mtDNA replication, following ethidium bromide treatment. These findings suggest FENMIT interacts with RNA/DNA hybrids in mitochondrial DNA, such as those found at the origin of replication.
In spite of amazing progress in food supply and nutritional science, and a striking increase in life expectancy of approximately 2.5 months per year in many countries during the previous 150 years, modern nutritional research has a great potential of still contributing to improved health for future generations, granted that the revolutions in molecular and systems technologies are applied to nutritional questions. Descriptive and mechanistic studies using state of the art epidemiology, food intake registration, genomics with single nucleotide polymorphisms (SNPs) and epigenomics, transcriptomics, proteomics, metabolomics, advanced biostatistics, imaging, calorimetry, cell biology, challenge tests (meals, exercise, etc.), and integration of all data by systems biology, will provide insight on a much higher level than today in a field we may name molecular nutrition research. To take advantage of all the new technologies scientists should develop international collaboration and gather data in large open access databases like the suggested Nutritional Phenotype database (dbNP). This collaboration will promote standardization of procedures (SOP), and provide a possibility to use collected data in future research projects. The ultimate goals of future nutritional research are to understand the detailed mechanisms of action for how nutrients/foods interact with the body and thereby enhance health and treat diet-related diseases.
molecular nutrition; nutrigenomics; genomics; transcriptomics; proteomics; metabolomics; systems biology; adipokines; myokines
There are risks related to blood incompatibility and blood-borne diseases when using allogeneic blood transfusion. Several alternatives exist today, one of which, used for autologous blood salvage perioperatively, is the Sangvia Blood Management System. This study was designed to investigate the efficacy of the system and to add data to previously reported safety results.
Two hundred sixteen patients undergoing primary or revision total hip arthroplasty (THA) were enrolled in this randomized, controlled, assessor-blinded multicenter study. Randomization was either autologous blood transfusion (Sangvia group) or no use of autologous blood (Control group), both in combination with a transfusion protocol for allogeneic transfusion. Patients were followed during hospital stay and at two months after discharge. The primary outcome was allogeneic blood transfusion frequency. Data on blood loss, postoperative hemoglobin/hematocrit, safety and quality of life were also collected. The effectiveness analysis including all patients showed an allogeneic blood transfusion rate of 14% in both groups. The efficacy analysis included 197 patients and showed a transfusion rate of 9% in the Sangvia group as compared to 13% in the Control group (95%CI −0.05–0.12, p = 0.5016). A mean of 522 mL autologous blood was returned in the Sangvia group and lower calculated blood loss was seen. 1095 mL vs 1285 mL in the Control group (95%CI 31–346, p = 0.0175). No differences in postoperative hemoglobin was detected but a lower hematocrit reduction after surgery was seen among patients receiving autologous blood. No relevant differences were found for safety parameters or quality of life.
General low use of allogeneic blood in THA is seen in the current study of the Sangvia system used together with a transfusion protocol. The trial setting is under-powered due to premature termination and therefore not able to verify efficacy for the system itself but contributes with descriptive data on safety.
This study aimed to assess the safety and feasibility of administering volociximab, a chimeric monoclonal antibody that specifically binds to α5β1 integrin, and to determine the pharmacokinetics, pharmacodynamics, and preliminary evidence of antitumor activity.
Patients with advanced solid malignancies were treated with escalating doses of volociximab i.v. administered over 60 minutes. Blood samples were assayed to determine plasma pharmacokinetic parameters, detect human antichimeric antibody formation, and determine the saturation of α5β1 sites on peripheral blood monocytes.
Twenty-one patients received 223 infusions of volociximab at doses ranging from 0.5 to 15 mg/kg i.v. on days 1, 15, 22, 29, and 36; and weekly thereafter. Treatment was well tolerated, and dose-limiting toxicity was not identified over the range examined. Mild (grade 1 or 2), reversible fatigue was the principal toxicity of volociximab at the highest dose levels of 10 and 15 mg/kg. Nausea, fever, anorexia, headache, vomiting, and myalgias were mild and infrequent, and there was no hematologic toxicity. Volociximab had biexponential distribution; clearance was inversely related to increasing dose, and the half-life at 15 mg/kg was estimated as being 30 days. Three patients tested positive for anti-volociximab antibodies. Saturation of monocyte α5β1 integrin sites was dose-dependent up to 15 mg/kg. There was one minor response (renal, 7 months) and one durable stable disease (melanoma, 14 months).
Volociximab can be safely administered at 15 mg/kg i.v. per week. The absence of severe toxicities and preliminary activity at the highest dose level warrants further disease-directed studies.
The kinesin spindle protein (KSP) is essential for separation of spindle poles during mitosis. Its inhibition results in mitotic arrest. This phase I trial examined safety, tolerability, dose-limiting toxicity (DLT), maximum tolerated dose (MTD), pharmacokinetic parameters, and anti-tumor activity of MK-0731, a potent inhibitor of KSP.
In part 1, patients with advanced solid tumors received MK-0731 intravenously over 24 h every 21 days starting at 6 mg/m2, escalating until MTD was reached. In part 2, patients with taxane-resistant tumors received the MTD. Plasma samples were collected to analyze the pharmacokinetics of MK-0731. Tumor response was evaluated using Response Evaluation Criteria in Solid Tumors (RECIST) v1.0.
In part 1, 21 patients (median age 63 years) were treated with MK-0731 at doses ranging from 6 to 48 mg/m2/24 h for median four cycles. The dose-limiting toxicity was neutropenia and the MTD was 17 mg/m2/24 h. At the MTD, AUC (±SD) was 10.5 (±7.3) μM × hour, clearance (±SD) was 153 mL/min (±84), and t1/2 was 5.9 h. In part 2, 22 patients received the MTD and there were no DLTs. Although there were no objective tumor responses, four patients (with cervical, non-small cell lung, and ovarian cancers) had prolonged stable disease.
MK-0731 at the MTD of 17 mg/m2/day every 21 days in patients with solid tumors had few grade 3 and 4 toxicities with the major DLTs at higher doses being myelosuppression. Anti-tumor efficacy was suggested by the length of stable disease in selected patients with taxane-resistant tumors.
Kinesin spindle protein; Oncology; Neutropenia
ZM336372 is small molecule tyrosine kinase modulator. It has been shown to inhibit glycogen synthase kinase-3β (GSK-3β) through phosphorylation of GSK-3β at Ser 9. GSK-3β has previously been shown to mediate cell survival in pancreatic cancer cells. Here we determine the effects of ZM336372 on GSK-3β phosphorylation, apoptosis, and growth in pancreatic adenocarcinoma cell lines.
Panc-1 and MiaPaCa-2 cells were treated with ZM336372 or lithium chloride (LiCl) and compared to solvent control. The effects on proliferation for each cell line were determined using the MTT assay. Western blot analysis was performed to examine the effects of treatment on the phosphorylation of GSK-3β. In addition, western blot was utilized to examine the cleavage of PARP, a marker of apoptosis.
A dose-dependent increase in phosphorylation of GSK-3β was observed after treatment with both ZM336372 and LiCl. Growth inhibition due to treatment with ZM336372 and LiCl also occurred in a dose-dependent fashion. An increase in cleaved PARP was demonstrated after treatment with both agents, as was seen previously with GSK-3β inhibition in pancreatic adenocarcinoma cells.
This is the first description of growth inhibition and apoptosis in pancreatic cancer cells related to GSK-3β inhibition through treatment with ZM336372.
ZM336372; lithium; GSK-3β; pancreatic cancer; apoptosis
Gamma-aminobutyric acid (GABA) is the major inhibitory neurotransmitter in the mammalian brain. Once released, it is removed from the extracellular space by cellular uptake catalyzed by GABA transporter proteins. Four GABA transporters (GAT1, GAT2, GAT3 and BGT1) have been identified. Inhibition of the GAT1 by the clinically available anti-epileptic drug tiagabine has been an effective strategy for the treatment of some patients with partial seizures. Recently, the investigational drug EF1502, which inhibits both GAT1 and BGT1, was found to exert an anti-convulsant action synergistic to that of tiagabine, supposedly due to inhibition of BGT1. The present study addresses the role of BGT1 in seizure control and the effect of EF1502 by developing and exploring a new mouse line lacking exons 3–5 of the BGT1 (slc6a12) gene. The deletion of this sequence abolishes the expression of BGT1 mRNA. However, homozygous BGT1-deficient mice have normal development and show seizure susceptibility indistinguishable from that in wild-type mice in a variety of seizure threshold models including: corneal kindling, the minimal clonic and minimal tonic extension seizure threshold tests, the 6 Hz seizure threshold test, and the i.v. pentylenetetrazol threshold test. We confirm that BGT1 mRNA is present in the brain, but find that the levels are several hundred times lower than those of GAT1 mRNA; possibly explaining the apparent lack of phenotype. In conclusion, the present results do not support a role for BGT1 in the control of seizure susceptibility and cannot provide a mechanistic understanding of the synergism that has been previously reported with tiagabine and EF1502.
GABA uptake; Epilepsy; Betaine–GABA transporter; SLC6A12; Conditional knockout; EF1502
Notch1 has been shown to be a tumor suppressor in neuroendocrine tumors. Previous in vitro studies in neuroendocrine tumor cell lines have also suggested that valproic acid, a histone deacetylase inhibitor, can induce Notch1 and that Notch1 activation correlates with a decrease in tumor markers for neuroendocrine tumors. This study showed that valproic acid activates Notch1 signaling in vivo and may have a role in treating low-grade neuroendocrine tumors.
Notch1 has been shown to be a tumor suppressor in neuroendocrine tumors (NETs). Previous in vitro studies in NET cell lines have also suggested that valproic acid (VPA), a histone deacetylase inhibitor, can induce Notch1 and that Notch1 activation correlates with a decrease in tumor markers for NETs. Thus, this study aimed to evaluate the role of VPA in treating NETs and to determine whether VPA induced the Notch signaling pathway signaling in vivo.
Patients and Methods.
Eight patients with low-grade NETs (carcinoid and pancreatic) were treated with 500 mg of oral VPA twice a day with dosing adjusted to maintain a goal VPA level between 50 and 100 μg/mL. All patients were followed for 12 months or until disease progression.
Notch1 signaling was absent in all tumors prior to treatment and was upregulated with VPA. One patient had an unconfirmed partial response and was noted to have a 40-fold increase in Notch1 mRNA levels. Four patients had stable disease as best response. Tumor markers improved in 5 out of 7 patients. Overall, treatment with VPA was well tolerated.
VPA activates Notch1 signaling in vivo and may have a role in treating low-grade NETs.
Neuroendocrine tumors; Valproic acid; Histone deacetylase inhibitor; Pancreatic carcinoid; Notch signaling
Prognosis remains poor after progression on first-line chemotherapy for colorectal adenocarcinoma, and inactivation of the EGFR pathway with monoclonal antibodies is an effective treatment strategy in selected patients with metastatic disease. Lapatinib is an oral EGFR and HER-2 dual tyrosine kinase inhibitor that has not shown significant activity in metastatic colorectal cancer. However, lapatinib may act synergistically with capecitabine in anticancer effects.
This was an open-label, non-randomized phase II study of lapatinib 1,250 mg orally daily and capecitabine 2,000 mg/m2 by mouth split into twice-daily dosing for 14 days of a 21 days cycle. Inclusion criteria included metastatic or locally advanced adenocarcinoma of the colon or rectum with progression by RECIST on or within six months of receiving a fluoridopyrimidine-, oxaliplatin- or irinotecan-containing regimen. Prior EGFR monoclonal antibody was permitted. K-ras testing was not routinely performed and was not a part of the study protocol.
Twenty nine patients (16 M; 13 F) were enrolled in this study. There were no complete or partial responses. 41.4% of patients achieved stable disease as a best response. Median overall survival was 6.8 months, with a 1-year survival rate of 22%, and median progression-free survival was 2.1 months. The combination produced few grade 3 and no grade 4 toxicities. No grade 3 toxicity occurred in more than 10% of patients.
Although capecitabine and lapatinib is well tolerated, it is not an effective regimen in patients with refractory colorectal adenocarcinoma.
Colorectal cancer; capecitabine; lapatinib; EGFR; Her-2
Notch1 has been shown to be a tumor suppressor in neuroendocrine tumors (NETs). Previous in-vitro studies in NET cell lines have also suggested that valproic acid (VPA), a histone deacetylase inhibitor, can induce Notch1, and that Notch1 activation correlates with a decrease in tumor markers for NET. Thus, this study aimed to evaluate the role of valproic acid in treating NETs and if VPA induced the Notch signaling pathway signaling in-vivo‥
Patients & Methods
Eight patients with low grade NETs (carcinoid and pancreatic) were treated with valproic acid 500 mg orally twice a day with dosing adjusted to maintain a goal VPA level between 50–100 mcg/mL. All patients were followed for 12 months or until disease progression.
Notch1 signaling was absent in all tumors prior to treatment, and was upregulated with VPA. One patient had an unconfirmed PR and was noted to have a 40-fold increase in Notch1 mRNA levels. Four patients had stable disease as best response. Tumor markers improved in 5/7 patients. Overall, treatment with VPA was well tolerated.
Valproic acid activates Notch1 signaling in-vivo and may have a role in treating low grade NET.
Neuroendocrine tumors; Valproic Acid; histone deacetylase inhibitor; pancreatic carcinoid; Notch signaling
The majority of deaths from breast cancer are a result of metastases; however, little is understood about the genetic alterations underlying their onset. Genetic profiling has identified the adhesion molecule plakoglobin as being three-fold reduced in expression in primary breast tumors that have metastasized compared with nonmetastatic tumors. In this study, we demonstrate a functional role for plakoglobin in the shedding of tumor cells from the primary site into the circulation.
We investigated the effects of plakoglobin knockdown on breast cancer cell proliferation, migration, adhesion, and invasion in vitro and on tumor growth and intravasation in vivo. MCF7 and T47D cells were stably transfected with miRNA sequences targeting the plakoglobin gene, or scramble vector. Gene and protein expression was monitored by quantitative polymerase chain reaction (qPCR) and Western blot. Cell proliferation, adhesion, migration, and invasion were measured by cell counting, flow cytometry, and scratch and Boyden Chamber assays. For in vivo experiments, plakoglobin knockdown and control cells were inoculated into mammary fat pads of mice, and tumor growth, shedding of tumor cells into the bloodstream, and evidence of metastatic bone lesions were monitored with caliper measurement, flow cytometry, and microcomputed tomography (μCT), respectively.
Plakoglobin and γ-catenin expression were reduced by more than 80% in all knockdown cell lines used but were unaltered after transfection with the scrambled sequence. Reduced plakoglobin resulted in significantly increased in MCF7 and T47D cell proliferation in vitro and in vivo, compared with control, with significantly more tumor cells being shed into the bloodstream of mice bearing plakoglobin knockdown tumors. In addition, plakoglobin knockdown cells showed a >250% increase in invasion through basement membrane and exhibited reduced cell-to-cell adhesion compared with control cells.
Decreased plakoglobin expression increases the invasive behavior of breast cancer cells. This is the first demonstration of a functional role for plakoglobin/γ-catenin in the metastatic process, indicating that this molecule may represent a target for antimetastatic therapies.
The efficacy of lithium chloride in patients with low-grade neuroendocrine tumors was evaluated and it was found to be ineffective in obtaining radiographic responses.
Low-grade neuroendocrine tumors (NETs) respond poorly to chemotherapy; effective, less toxic therapies are needed. Glycogen synthase kinase (GSK)-3β has been shown to regulate growth and hormone production in NETs. Use of lithium chloride in murine models suppressed carcinoid cell growth, reduced GSK-3β levels, and reduced expression of chromogranin A. This study assessed the efficacy of lithium chloride in patients with NETs.
Eligible patients had low-grade NETs. A single-arm, open-label phase II design was used. Lithium was dosed at 300 mg orally three times daily, titrated to serum levels of 0.8–1.0 mmol/L. The primary endpoint was objective tumor response by the Response Evaluation Criteria in Solid Tumors. Secondary endpoints included overall survival, progression-free survival, GSK-3β phosphorylation, and toxicity.
Fifteen patients were enrolled between October 3, 2007 and July 17, 2008, six men and nine women. The median age was 58 years. Patient diagnoses were carcinoid tumor for eight patients, islet cell tumor for five patients, and two unknown primary sites. Eastern Cooperative Oncology Group performance status scores were 0 or 1. Two patients came off study because of side effects. The median progression-free survival interval was 4.50 months. There were no radiographic responses. Because of an early stopping rule requiring at least one objective response in the first 13 evaluable patients, the study was closed to further accrual. Patients had pre- and post-therapy biopsies.
Lithium chloride was ineffective at obtaining radiographic responses in our 13 patients who were treated as part of this study. Based on the pre- and post-treatment tumor biopsies, lithium did not potently inhibit GSK-3β at serum levels used to treat bipolar disorders.
Neuroendocrine tumors; Lithium chloride; Glycogen synthase kinase-3β; Chemotherapy; Carcinoid tumors
Questionnaires on physical activity (PA) and physical capacity (PC) are valuable tools, as they are cost beneficial, and have high response rates. The validity of short versions of such questionnaires has not been examined satisfactorily. Therefore, we aimed at examining the validity of a set of questions coding for PA and PC.
The questions were administered to 217 men and women attending a cardiac rehabilitation program. Participants also gave blood samples, measuring HDL cholesterol, triglycerides (TG), insulin, glucose, and microCRP. The relations between PA and PC and biological markers were examined by linear regression analyses.
Measures for PC and for PA were identified by factor analysis, which proved internally consistent. TG, homeostatic model assessment (HOMA) score, and mCRP were all significantly associated with the measures of PC and PA.
The measures of PA and PC are valid compared with biological markers, allowing cost-beneficial and time-efficient evaluation of important measures for cardiovascular health.
Cardiac rehabilitation; motor activities; outcome assessment; physical fitness; questionnaires.
Tumour cells communicate with the cells of their microenvironment via a series of molecular and cellular interactions to aid their progression to a malignant state and ultimately their metastatic spread. Of the cells in the microenvironment with a key role in cancer development, tumour associated macrophages (TAMs) are among the most notable. Tumour cells release a range of chemokines, cytokines and growth factors to attract macrophages, and these in turn release numerous factors (e.g. VEGF, MMP-9 and EGF) that are implicated in invasion-promoting processes such as tumour cell growth, flicking of the angiogenic switch and immunosuppression. TAM density has been shown to correlate with poor prognosis in breast cancer, suggesting that these cells may represent a potential therapeutic target. However, there are currently no agents that specifically target TAM's available for clinical use.
Bisphosphonates (BPs), such as zoledronic acid, are anti-resorptive agents approved for treatment of skeletal complication associated with metastatic breast cancer and prostate cancer. These agents act on osteoclasts, key cells in the bone microenvironment, to inhibit bone resorption. Over the past 30 years this has led to a great reduction in skeletal-related events (SRE's) in patients with advanced cancer and improved the morbidity associated with cancer-induced bone disease. However, there is now a growing body of evidence, both from in vitro and in vivo models, showing that zoledronic acid can also target tumour cells to increase apoptotic cell death and decrease proliferation, migration and invasion, and that this effect is significantly enhanced in combination with chemotherapy agents. Whether macrophages in the peripheral tumour microenvironment are exposed to sufficient levels of bisphosphonate to be affected is currently unknown. Macrophages belong to the same cell lineage as osteoclasts, the major target of BPs, and are highly phagocytic cells shown to be sensitive to bisphosphonates in model studies; In vitro, zoledronic acid causes increased apoptotic cell death; in vivo the drug has been shown to inhibit the production of pro-angiogenic factor MMP-9, as well as most recent evidence showing it can trigger the reversal of the TAMs phenotype from pro-tumoral M2 to tumoricidal M1. There is thus accumulating evidence supporting the hypothesis that effects on TAMs may contribute to the anti-tumour effect of bisphosphonates. This review will focus in detail on the role of tumour associated macrophages in breast cancer progression, the actions of bisphosphonates on macrophages in vitro and in tumour models in vivo and summarise the evidence supporting the potential for the targeting of tumour macrophages with bisphosphonates.
Bisphosphonates; macrophages; zoledronic acid; tumour microenvironment; tumour-associated macrophages; anti-tumour effect; mevalonate pathway
Low-grade neuroendocrine tumors (NETs) respond poorly to chemotherapy; effective, less toxic therapies are needed. Glycogen synthase kinase (GSK)-3β has been shown to regulate growth and hormone production in NETs. Use of lithium chloride in murine models suppressed carcinoid cell growth, reduced GSK-3β levels and reduced expression of chromogranin A. This study assessed the efficacy of lithium chloride in patients with NETs.
Eligible patients had low-grade NETs. A single-arm, open-label phase II design was used. Lithium was dosed at 300mg orally TID, titrated to serum levels of 0.8–1.0mmol/L. The primary endpoint was objective tumor response by RECIST. Secondary endpoints included overall survival, progression-free survival, GSK-3β phosphorylation, and toxicity.
15 patients were enrolled between 10/3/07 and 7/17/08; 6 men, 9 women. The median age was 58. Patients’ diagnoses were carcinoid tumor for 8 pts, islet cell tumor for 5 pts, and 2 unknown primary sites. ECOG PS was 0 or 1. Two pts came off study due to side effects. Median progression-free survival was 4.50 months. There were no radiographic responses. Due to an early stopping rule requiring at least 1 objective response in the first 13 evaluable pts, the study was closed to further accrual. Patients had pre- and post-therapy biopsies.
Lithium chloride was ineffective at obtaining radiographic responses in our 13 patients who were treated as part of this study. Based on the pre- and post- treatment tumor biopsies, lithium did not potently inhibit GSK-3β at serum levels utilized to treat bipolar disorders.
Neuroendocrine tumors; lithium chloride; glycogen synthase kinase-3 beta; chemotherapy; carcinoid tumors
Biliary cancers overexpress epidermal growth factor receptor (EGFR), and angiogenesis has been correlated with poor outcome. Erlotinib, an EGFR tyrosine kinase inhibitor, and bevacizumab, a vascular endothelial growth factor (VEGF) inhibitor have each been shown to have activity in biliary cancer. The primary objective of this study was to evaluate the response rate by Response Evaluation Criteria in Solid Tumors (RECIST). Secondary end points included overall survival (OS), time to progression (TTP), VEGF levels, and molecular studies of EGFR and k-ras.
Patients and Methods
Eligible patients had advanced cholangiocarcinoma or gallbladder cancer. Patients were treated with bevacizumab 5 mg/kg intravenously on days 1 and 15 and erlotinib 150 mg by mouth daily on days 1 through 28. Responses were evaluated by RECIST. VEGF levels were collected, and samples were analyzed for EGFR mutation by polymerase chain reaction.
Fifty-three eligible patients were enrolled at eight sites. Of 49 evaluable patients, six (12%; 95% CI, 6% to 27%) had a confirmed partial response. Stable disease was documented in another 25 patients (51%). Rash was the most common grade 3 toxicity. Four patients had grade 4 toxicities. Median OS was 9.9 months, and TTP was 4.4 months. Low repeats (< 16) in EGFR intron 1 polymorphism and G>G k-ras Q38 genotype (wild type) were associated with improved outcomes.
Combination chemotherapy with bevacizumab and erlotinib showed clinical activity with infrequent grade 3 and 4 adverse effects in patients with advanced biliary cancers. On the basis of preliminary molecular analysis, presence of a k-ras mutation may alter erlotinib efficacy. The combination of bevacizumab and erlotinib may be a therapeutic alternative in patients with advanced biliary cancer.
There is increasing evidence of anti-tumour effects of bisphosphonates from pre-clinical studies, supporting a role for these drugs beyond their traditional use in treatment of cancer-induced bone disease. A range of model systems have been used to investigate the effects of different bisphosphonates on tumour growth, both in bone and at peripheral sites. Most of these studies conclude that bisphosphonates cause a reduction in tumour burden, but that early intervention and the use of high and/or repeated dosing is required. Successful eradication of cancer may only be achievable by targeting the tumour cells directly whilst also modifying the tumour microenvironment. In line with this, bisphosphonates are demonstrated to be particularly effective at reducing breast tumour growth when used in combination with agents that directly target cancer cells. Recent studies have shown that the effects of bisphosphonates on breast tumours are not limited to bone, and that prolonged anti-tumour effects may be achieved following their inclusion in combination therapy. This has opened the field to a new strand of bisphosphonate research, focussed on elucidating their effects on cells and components of the local, regional and distal tumour microenvironment. This review highlights the recent developments in relation to proposed anti-tumour effects of bisphosphonates reported from in vitro and in vivo models, and summarises the data from key breast cancer studies. Evidence for effects on different processes and cell types involved in cancer development and progression is discussed, and the main outstanding issues identified.
Capecitabine has shown similar efficacy to 5-fluorouracil (5-FU); a regimen containing 2 weeks of capecitabine/oxaliplatin (CapOx) has demonstrated noninferiority to infusional 5-FU/oxaliplatin/leucovorin (FOLFOX) for the treatment of metastatic colorectal cancer (mCRC). This phase II study explores the efficacy and safety of a 2-day course of oxaliplatin/capecitabine (2DOC), with oxaliplatin given on day 1 and capecitabine given orally every 8 hours in high doses over 6 doses, mimicking FOLFOX6.
Patients and Methods
This phase II study was conducted by the University of Wisconsin Carbone Cancer Center. Eligible patients with mCRC received oxaliplatin 100 mg/m2 intravenously (I.V.) over 2 hours followed by leucovorin 20 mg/m2 I.V. bolus and 5-FU 400 mg/m2 I.V. bolus on day 1 and day 15. Capecitabine was administered at 1500 mg/m2 orally every 8 hours over 6 doses starting on day 1 and day 15.
A total of 45 patients were enrolled; 44 were evaluated for response. Seventeen patients (39%) had objective responses. Median time to progression was 6.8 months, and median overall survival (OS) was 17.5 months. The most common side effects were grade 1/2 neuropathy, fatigue, and nausea. Severe hand-foot syndrome (HFS) was rare.
The overall response rate with the 2DOC regimen is similar to published CapOx regimens, and time to progression and OS are similar. The incidence of HFS, diarrhea, and mucositis were lower compared with published results of 2-week schedules of capecitabine. The 2DOC regimen merits further study as a more convenient regimen than infusional 5-FU with less HFS when compared with a 2-week administration of capecitabine.
2DOC; FOLFOX6; Irinotecan; Neutropenia; Thrombocytopenia
The purpose of this study was to develop a population pharmacokinetic (PK) model for 3-AP pharmacokinetics and to evaluate the effect of ABCB1 polymorphisms on the pharmacokinetic profile of 3-AP and to assess the relationship between 3AP disposition and patient covariates.
A total of 40 patients with advanced cancer from two phase 1 studies were included in the population PK model building. Patients received 3-AP 25–105 mg/m2 IV on day 1. 3-AP plasma and erythrocyte levels were sampled at 10 timepoints over a 24-hour period and measured by a validated HPLC method. Data were analyzed by a nonlinear mixed-effects modeling approach using the NONMEM system.
3AP pharmacokinetics were described as a 3-compartment model with first-order elimination. One compartment representing the plasma and another representing erythrocyte concentrations. Gender was associated with volume of distribution, in which women had a lower V2. The number of cycles administered was associated with clearance; those with decreased clearance were more likely to receive less than 2 cycles before going off study.
This study suggests that monitoring 3-AP plasma concentrations in the first cycle and dose adjustment in those with decreased clearance may be helpful in decreasing toxicity associated with the 3-AP.
Triapine®; 3-aminopyridine-2-carboxaldehyde thiosemicarbazone; population pharmacokinetics; phase 1
Aromatase inhibitors are widely used in the treatment of oestrogen receptor-positive post-menopausal breast cancer. These patients may also be receiving the bisphosphonate, zoledronic acid (ZA) to prevent bone loss or reduce skeletal morbidity in the setting of advanced disease. The potential biological interaction of these two drugs in breast cancer has not been assessed.
Aromatase-expressing breast cancer cells were treated with letrozole and ZA either simultaneously or in sequence, and the resulting apoptosis was assessed by staining with Hoechst 33342 and propidium iodide and examined using a fluorescent inverted Leica DMIRB microscope and a UV filter.
We found that letrozole and ZA induce levels of apoptosis in breast cancer cells in vitro that are significantly greater compared with treatment with each drug alone. However, this potentially, synergistic relationship is drug-sequence dependent, occurring only when cells are treated with letrozole, followed by ZA. The converse sequence, or administering drugs simultaneously, induces levels of apoptosis no greater than each drug alone.
Owing to the enhanced anti-tumour efficacy of sequential drug administration, our findings may indicate that, for post-menopausal women who require treatment with letrozole, ZA should also be considered.
zoledronic acid; letrozole; apoptosis; synergy; breast cancer
Tumor metastasis to the skeleton affects over 400,000 individuals in the United States annually, more than any other site of metastasis, including significant proportions of patients with breast, prostate, lung and other solid tumors. Research on the bone microenvironment and its role in metastasis suggests a complex role in tumor growth. Parallel preclinical and clinical investigations into the role of adjuvant bone-targeted agents in preventing metastasis and avoiding cancer therapy-induced bone loss have recently reported exciting and intriguing results. A multidisciplinary consensus conference convened to review recent progress in basic and clinical research, assess gaps in current knowledge and prioritize recommendations to advance research over the next 5 years. The program addressed three topics: advancing understanding of metastasis prevention in the context of bone pathophysiology; developing therapeutic approaches to prevent metastasis and defining strategies to prevent cancer therapy-induced bone loss. Several priorities were identified: (1) further investigate the effects of bone-targeted therapies on tumor and immune cell interactions within the bone microenvironment; (2) utilize and further develop preclinical models to study combination therapies; (3) conduct clinical studies of bone-targeted therapies with radiation and chemotherapy across a range of solid tumors; (4) develop biomarkers to identify patients most likely to benefit from bone-targeted therapies; (5) educate physicians on bone loss and fracture risk; (6) define optimal endpoints and new measures of efficacy for future clinical trials; and (7) define the optimum type, dose and schedule of adjuvant bone-targeted therapy.
Metastasis; Bisphosphonate; RANK; Bone targeted; PTHrP; Bone loss; Denosumab; Zoledronic acid
There are no clear predictors clinicians can use to determine who is more likely to experience dose limiting toxicity (DLT) in phase I chemotherapy clinical trials. Many providers are reluctant to refer older adults to phase I trials because of concerns about the development of toxicity. The goal of this study was to identify clinical and nonclinical factors which were associated with the development of DLT in phase I studies
Patients (pts) were included if they were treated at maximally tolerated dose (MTD) and above. Studies were included only if MTD was reached. Data collected included age, comorbidity (Cumulative Illness Rating Score-Geriatrics), labs at enrollment, height, weight, performance status, cancer type, duration of diagnosis, prior treatment, drug level, smoking status, marital status, mean income, percent of population high school educated as determined by ZIP code, and distance to the phase I trial hospital. Those who did and did not have DLT were compared by bivariate and then multivariate analysis.
242 charts were reviewed, from 24 cytotoxic chemotherapy studies, and 27 different types of cancer were represented. On bivariate analysis, mean age, household income (higher), weight, body surface area, dose of drug, alkaline phosphatase, hemoglobin, and LDH were significantly associated with DLT (p<0.05). CIRS-G score was not associated with DLT. In multivariate analysis dose level (p=0.004) and distance from the phase I trial hospital (p=0.04) were still significant predictors of DLT. Age did not predict for severity of DLT.
Age and comorbidity did not predict for development of DLT in phase I chemotherapy trials. Many of these pts were very fit, with relatively low CIRS-G scores, so the impact of comorbidity may not have been fully evaluated. Several social and clinical factors may predict for development of DLT. A prospective study is being planned to confirm these results.
3-AP (3-aminopyridine-2-carboxaldehyde thiosemicarbazone, 3-AP) is a metal chelator that potently inhibits the enzyme ribonucleotide reductase, RR, which plays a key role in cell division and tumor progression. A sub-unit of RR has a non-heme iron and a tyrosine free radical, which are required for the enzymatic reduction of ribonucleotides to deoxyribonucleotides. The objective of the study was to determine whether 3-AP affects its targeted action by measuring EPR signals formed either directly or indirectly from low molecular weight ferric-3-AP chelates.
Peripheral blood lymphocytes were collected from patients with refractory solid tumors at baseline and at 2, 4.5 and 22 hours after 3-AP administration. EPR spectra were used to identify signals from high-spin Fe-transferrin, high-spin heme and low-spin iron or copper ions.
An increase in Fe-transferrin signal was observed, suggesting blockage of Fe uptake. It is hypothesized that formation of reactive oxygen species by FeT2 or CuT damage transferrin or the transferrin receptor. An increase in heme signal was also observed, which is a probable source of cytochrome c release from the mitochondria and potential apoptosis. In addition, increased levels of Fe and Cu were identified.
These results, which were consistent with our earlier study validating 3-AP-mediated signals by EPR, provide valuable insights into the in vivo mechanism of action of 3-AP.
3-AP; EPR; ribonucleotide reductase; chelator