Symptom burden and survival outcome: 3 cycles versus 6 cycles of chemotherapy in advanced NSCLC

17054

Background: Improving survival and quality of life is the primary treatment goal for patient with advanced NSCLC receiving palliative chemotherapy. The optimal treatment duration remains to be determined, and there are few studies that examine longitudinal symptom burden in this population. Methods: We prospectively collected self-reported symptom data from advanced stage NSCLC patients receiving chemotherapy. Symptom data was collected weekly utilizing the MD Anderson Symptom Inventory (15 symptoms) pre chemotherapy until therapy discontinuation or up to 26 weeks. Principal components analysis of symptoms measures with a Varimax rotation were used to identify symptom clusters. A piecewise linear mixed-effect regression model was used to estimate the changes over time in symptom severity, and Cox modeling was used for data analysis. Results: Data from 102 subjects were available for analysis. Chemotherapy was primarily discontinued because of tumor progression or a decline in the patient's functional status. Seventy patients received only 2 cycles of chemotherapy, while 46 and 29 patients received 4 and 6 cycles of chemotherapy, respectively. Four clusters of symptoms were identified prior to therapy, including: general symptoms (such as pain, fatigue, sleeping disturbance), GI distress (nausea, vomiting, lack of appetite & constipation), affective symptoms (sadness & distress) and specific disease related symptoms (coughing & shortness of breath). In patients who received = 3 cycles of chemotherapy, a rapid increased in symptom severity was observed, compared to those who received > 3 cycles (P<.05). Patients who received =3 cycles of chemotherapy demonstrated shorter survival compared to those who received > 3 of chemotherapy (HR=9.9, CI=4–22.7, P<.001). Conclusion: Patients with advanced NSCLC who received more than 3 cycles of chemotherapy demonstrated more stable symptom burden and longer survival compared to those who received = 3 cycles of chemotherapy.

No significant financial relationships to disclose.

Palliative chemotherapy and cancer-related fatigue in advanced NSCLC patients

6622

Background: Cancer-related fatigue is one the most severe and prevalent symptoms in patients with advanced-stage non- small cell lung cancer (NSCLC). Whether palliative chemotherapy causes additional fatigue, beyond that which is caused by the disease itself, is unknown. Methods: Study subjects were 88 patients with advanced NSCLC who were treated with platinum-based chemotherapy at The University of Texas M. D. Anderson Cancer Center. Fatigue severity and other symptoms were measured weekly using the 0–10 rating scales of the M. D. Anderson Symptom Inventory (MDASI). Using mixed-effect modeling, we assessed fatigue severity over time of receiving chemotherapy. Results: Over the time of this longitudinal symptom assessment study, fatigue severity was overwhelmingly higher than all other symptoms. We observed no significant impact on fatigue severity by age, sex, or race/ethnicity variation; however, there was a significant difference in fatigue severity using longitudinal analysis between patients who discontinued chemotherapy within 0–6 week vs beyond 12 weeks (P<.05), and within 6–12 weeks vs beyond 12 weeks (P<0.01). By each cycle of chemotherapy, the fatigue pattern showed a consistent trend of reduced severity at day 0–3, a fatigue peak on day 5–6 (P<.05), then unchanged during days 7–21. Fatigue was most severe during the first cycle. Discussion: Cancer-related fatigue was the most severe symptom in the study sample, especially for patients only able to receive 2–4 cycles of chemotherapy. However, patients who received over 4 cycles of chemotherapy had a stable level of fatigue, which indicates that continued chemotherapy does not increase fatigue. Additional analysis demonstrated that fatigue was at it's lowest immediately following chemotherapy, possibly related to the use of steroids in conjunction with chemotherapy administration.

No significant financial relationships to disclose.

Density-driven segregation in vertically vibrated binary granular mixtures

Segregation in vertically vibrated binary granular mixtures with the same size is studied experimentally. The partially segregated state occurring in this system is observed carefully. We find that the characteristic of the partially segregated state is that the lighter particles tend to rise and form a pure layer on the top of the system while the heavier particles and some of the lighter ones stay at the bottom and form a mixed layer. The ratio of the thickness of the pure top layer to that of the whole system can be taken as an order parameter, which describes the degree of the segregation quantitatively and is useful in the investigation of the system. By use of it, we find that the segregation state is only dependent on the density ratio of the two kinds of particles. The dependent of the segregation on the vibration frequency is also studied by use of this order parameter, and finally, two typical phase diagrams are given.

Responses of the mitochondrial alpha-ketoglutarate dehydrogenase complex to thiamine deficiency may contribute to regional selective vulnerability

Thiamine-dependent enzymes are diminished in multiple neurodegenerative diseases. Thiamine deficiency (TD) reduces the activity of thiamine dependent-enzymes [e.g., the alpha-ketoglutarate dehydrogenase complex (KGDHC)], induces regional selective neurodegeneration and serves as a model of a mild impairment of oxidative metabolism. The current experiments tested whether changes in KGDHC protein subunits (E1k, E2k and E3) or activity or message levels underlie the selective loss of neurons in particular brain regions. Thus, TD-induced changes in these variables in the brain region most vulnerable to TD [the sub-medial thalamic nucleus (SmTN)] were compared to those in a region that is relatively resistant to TD (cortex) at stages of TD when the neuron loss in SmTN is not present, minimal or severe. Impaired motor performance on rotarod was apparent by 8 days of TD (-32%) and was severe by 10 days of TD (-97%). At TD10, the overall KGDHC activity measured by an in situ histochemical staining method declined 52% in SmTN but only 20% in cortex. Reductions in the E2k and E3 mRNA in SmTN occurred as early as TD6 (-28 and -18%, respectively) and were more severe by TD10 (-61 and -66%, respectively). On the other hand, the level of E1k mRNA did not decline in SmTN until TD10 (-48%). In contrast, TD did not alter mRNA levels of the subunits in cortex at late stages. Western blots and immunocytochemistry revealed different aspects of the changes in protein levels. In SmTN, the immunoreactivity of E1k and E3 by Western blotting increased 34 and 40%, respectively, only at TD8. In cortex, the immunoreactivity of the three subunits was not altered. Immunocytochemical staining of brain sections from TD10 mice indicated a reduction in the immunoreactivity of all subunits in SmTN, but not in cortex. These findings demonstrate that the response of the KGDHC activity, mRNA and immunoreactivity of E1k, E2k and E3 to TD is region and time dependent. Loss of KGDHC activity in cortex is likely related to post-translational modification rather than a loss of protein, whereas in SmTN transcriptional and post-translational modifications may account for diminished KGDHC activity. Moreover, the earlier detection in TD induced-changes of the transcripts of KGDHC indicates that transcriptional modification of the two subunits (E2k and E3) of KGDHC may be one of the early events in the cascade leading to selective neuronal death.

Hydrogen Dynamics in Na3AlH6: A Combined Density Functional Theory and Quasielastic Neutron Scattering Study

Understanding the elusive catalytic role of titanium-based additives on the reversible hydrogenation of complex hydrides is an essential step toward developing hydrogen storage materials for the transport sector. Improved bulk diffusion of hydrogen is one of the proposed effects of doping sodium alanate with TiCl3, and here we study hydrogen dynamics in doped and undoped Na3AlH6 using a combination of density functional theory calculations and quasielastic neutron scattering. The hydrogen dynamics is found to be vacancy mediated and dominated by localized jump events, whereas long-range bulk diffusion requires significant activation. The fraction of mobile hydrogen is found to be small for both undoped and doped Na3AlH6, even at 350 K, and improved hydrogen diffusion as a result of bulk-substituted titanium is found to be unlikely. We also propose that previously detected low-temperature point defect motion in sodium alanate could result from vacancy-mediated sodium diffusion.

PD-L1 expression analysis in gastric carcinoma tissue and blocking of tumor-associated PD-L1 signaling by two functional monoclonal antibodies

Programmed death-1 ligand-1 (PD-L1), a member of the B7 family of costimulatory molecules, plays an important role in the regulations of the cellular and humoral immune responses. In this study, two mouse anti-human PD-L1 monoclonal antibodies named 10E10 and 2H11 were successfully generated and further characterized. Monoclonal antibody 10E10 bound to distinct PD-L1 epitope comparing an available anti-PD-L1 monoclonal antibody on a series of malignant cell lines, activated T lymphocytes, B lymphocytes and dendritic cells. Then, by using immunohistochemistry staining with monoclonal antibody 2H11, the expression of PD-L1 was found in human gastric carcinoma specimens but not in normal or gastric adenoma tissues. Additional data show that PD-L1 can be regarded as a decisive factor in evaluating gastric carcinoma prognosis and anti-human PD-L1 monoclonal antibody 10E10 could inhibit T-cell apoptosis induced by tumor-associated PD-L1. Taken together, these results showed that the two functional mouse anti-human PD-L1 monoclonal antibodies we generated might be of great value for further exploration of the costimulatory molecule regulating network and immunointervention for tumor immunotherapy.

Evidence for two distinct pathways in TNFalpha-induced membrane and soluble forms of ICAM-1 in human osteoblast-like cells isolated from osteoarthritic patients

OBJECTIVE

The present study aimed to investigate the modulation of membrane-bound intercellular adhesion molecule-1 (mICAM-1) and soluble ICAM-1 (sICAM-1) expression by tumor necrosis factor-alpha (TNFalpha) in human osteoarthritic (OA) osteoblasts.

METHODS

Cultured human primary osteoblasts were stimulated with increasing concentrations of human recombinant TNFalpha. Expression of mICAM-1 and sICAM-1 was evaluated by immunocytochemistry, enzyme-linked immunosorbent assay and semi-quantitative reverse transcriptase-polymerase chain reaction. In addition, we investigated the molecular mechanisms underlying ICAM-1 induction by TNFalpha, focusing on the activation of the mitogen-activated protein kinases (MAPKs) and nuclear factor-kappaB (NF-kappaB) pathways.

RESULTS

Our data showed that TNFalpha dose-dependently increased mICAM-1 and sICAM-1 expression at the protein and mRNA levels in OA osteoblasts. The inhibitor of de novo mRNA synthesis, actinomycin D, suppressed TNFalpha-induced mICAM-1 and sICAM-1 expression. Upon examination of the signaling components, we found that TNFalpha was a potent activator of p38, p44/42, p54/46 MAPK, and IkappaBalpha (IkappaBalpha). The chemical inhibitors of p38, p44/42 MAPK, and NF-kappaB blocked TNFalpha-induced mICAM-1 expression but not that of sICAM-1. Transfection experiments revealed that p38 MAPK or IkappaB kinase alpha (IKKalpha) overexpression enhanced TNFalpha-induced mICAM-1 production. Furthermore, osteoblasts treatment with a chemical inhibitor of metalloproteinase-9 (MMP-9) activity, a proteolytic enzyme involved in ICAM-1 cleavage, evoked a significant 25% decrease of TNFalpha-induced sICAM-1 release.

CONCLUSION

Taken together, these findings illustrate the central role played by TNFalpha in the regulation of ICAM-1. We suggest that TNFalpha differentially regulates sICAM-1 and mICAM-1 expression and that sICAM-1 release involves, in part, the proteolytic cleavage of mICAM-1 by MMP-9. The capacity of the MMP-9 inhibitor to prevent sICAM-1 production may be useful for the development of novel therapeutic approaches relevant to OA.

FDTD Simulation of Nonlinear Ultrasonic Pulse Propagation in ESWL

The extracorporeal shock wave lithotripsy (ESWL) has come into wide use due to its non-invasive advantage. However, as for the shock wave propagation in human body in relation to practical lithotripsy, there are a few studies on numerical simulation based on models conforming to practical situations. In this paper we report a numerical method of finite difference time domain (FDTD) for analyzing ultrasonic pulse nonlinear propagation in human body tissues and demonstrated it through an experiment of Reichenberger's ESWL in water.

Lentivirus-mediated platelet-derived factor VIII gene therapy in murine haemophilia A

BACKGROUND

Previous studies from our laboratory have demonstrated that lineage-targeted synthesis of factor VIII (FVIII) under the direction of the platelet-specific integrin alphaIIb gene promoter (2bF8) can correct the murine haemophilia A phenotype even in the presence of high titer inhibitory antibodies in a transgenic mouse model.

OBJECTIVE

In this study, we assessed the efficacy of using a genetic therapy approach to correct haemophilia A in FVIII-deficient (FVIII(null)) mice by transplantation of bone marrow (BM) transduced with a lentivirus (LV)-based gene transfer cassette encoding 2bF8.

RESULTS

Functional FVIII activity (FVIII:C) was detected in platelet lysates from treated mice and the levels were similar to 2bF8 heterozygous transgenic mice. Mice transplanted with 2bF8 LV-transduced BM survived tail clipping and we did not detected inhibitory or non-inhibitory FVIII antibodies over the period of this study (11 months). Furthermore, BM transferred from the primary transplant recipients into FVIII(null) secondary recipients demonstrated sustained platelet-FVIII expression leading to correction of the haemophilia A phenotype showing that gene transfer occurred within long-term repopulating haematopoietic stem cells.

CONCLUSIONS

These results demonstrate that ectopic expression of FVIII in platelets by lentivirus-mediated bone marrow transduction/transplantation may be a promising strategy for gene therapy of haemophilia A in humans.

Targeting SPARC expression decreases glioma cellular survival and invasion associated with reduced activities of FAK and ILK kinases

Secreted protein acidic and rich in cysteine (SPARC) is an extracellular glycoprotein expressed in several solid cancers, including malignant gliomas, upon adoption of metastatic or invasive behaviors. SPARC expression in glioma cells promotes invasion and survival under stress, the latter process dependent on SPARC activation of AKT. Here we demonstrate that downregulation of SPARC expression with short interfering RNA (siRNA) in glioma cells decreased tumor cell survival and invasion. SPARC siRNA reduced the activating phosphorylation of AKT and two cytoplasmic kinases, focal adhesion kinase (FAK) and integrin-linked kinase (ILK). We determined the contributions of FAK and ILK to SPARC effects using SPARC protein and cell lines engineered to overexpress SPARC. SPARC activated FAK and ILK in glioma cells previously characterized as responsive to SPARC. Downregulation of either FAK or ILK expression inhibited SPARC-mediated AKT phosphorylation, and targeting both FAK and ILK attenuated AKT activation more potently than targeting either FAK or ILK alone. Decreased SPARC-mediated AKT activation correlated with a reduction in SPARC-dependent invasion and survival upon the downregulation of FAK and/or ILK expression. These data further demonstrate the role of SPARC in glioma tumor progression through the activation of intracellular kinases that may provide novel therapeutic targets for advanced cancers.

Cerebrovascular disease among patients from the Indian subcontinent

In this study, the authors document the characteristics of South Asian (SA) cerebrovascular patients. A retrospective medical record review comparing SA (n = 99) and European-American (n = 106) patients was performed. SA patients were younger and had a greater prevalence of diabetes, but lower prevalences of hyperlipidemia and tobacco use. SA patients experienced a 75% lower risk of cardiogenic infarctions, but a threefold increased risk of intracranial atherothrombosis. Risk factor modifications and secondary prevention strategies may differ for SA patients.

Changes in serum cardiac troponins following a 21-km run in junior male runners

AIM

This study was designed to examine the appearance and clearance characteristics of serum cardiac troponin T (cTnT) and I (cTnI) in junior runners after an exhaustive 21-km run. The dependence of the alternations of the cardiac troponins on the runners' training status reflected in training years, running ability and physiological profile at ventilatory threshold (Th(vent)) was also examined.

METHODS

Ten trained male adolescents (16.2+/-0.6 years) performed 21-km run and graded treadmill exercise with maximum effort on two different days. cTnT and cTnI immediately before and 2, 4 and 24 hours after exercise were measured in the 21-km trial. The parameters at Thvent including the running speed (Th(vent)-Speed) and VO2 (Th(vent)-VO2) were identified in the graded exercise trial.

RESULTS

Serum cTnT and cTnI in 6 of the 10 subjects measured 4 hours after the 21-km run were above the myocardial injury cutoffs of 0.03 and 0.09 ng x mL(-1), respectively, but returned towards pre-exercise levels within 24 hours that were not in the same manner observed in the clinical situation of myocardial infraction. The 6 subjects' training status was generally lower than that of the rest 4. Further, subjects' 4-h serum cTnT and cTnI were negatively related to their training years, Th(vent)-Speed and Th(vent)-VO2, and positively related to their personal best in half- and full-marathon races (r2 = or > 36%, n = 10).

CONCLUSIONS

Such findings implied that clinicians based the diagnosis of long-distance run-induced myocardial infraction in novice junior runners upon the transient postexercise elevations of cardiac troponins alone should be with caution.

A novel low molecular weight inhibitor of focal adhesion kinase and insulin-like growth factor-1 receptor, TAE226, inhibits glioma growth

11505

Background: Glioblastomas are highly lethal cancers that resist current therapies. Focal adhesion kinase (FAK) is a non-receptor tyrosine kinase overexpressed in glioblastoma patient specimens that may promote glioma growth and invasion by increasing cellular adhesion, migration, invasion, proliferation. TAE226 is a novel low molecular weight inhibitor of several kinases that demonstrates in vitro activity primarily against FAK with activity against insulin-like growth factor-1 receptor (IGF1R) at higher concentrations. Methods: As FAK and IGF1R are potential molecular targets in glioblastomas, we examined the efficacy of TAE226 against human glioma cell lines and xenografts. Results: TAE226 inhibited the activating phosphorylation of FAK at submicromolar concentrations with residue specific preference. Downstream effectors (Akt and ERK) were inhibited at slightly higher concentrations. TAE226 demonstrated a concentration-dependent decrease in cellular proliferation with an associated G2 cell cycle arrest in multiple glioma cell lines, whereas TAE226 potently induced apoptosis in a concentration-dependent manner in only one of four cell lines tested. TAE226 also induced a concentration-dependent decrease in cellular adhesion, migration, and invasion. In preliminary animal studies, a limited course of orally administered TAE226 (100 mg/kg qd 5 days on/2 days off/5 days) was well tolerated with minimal weight loss. TAE226 induced a modest growth delay of human glioma xenografts grown in a subcutaneous location in athymic mice (3 to 4 days delay, p < 0.001). In addition, mice bearing orthotopic intracranial human glioma xenografts demonstrated a modest increase in median survival (3.5 days, p = 0.078). Despite the modest degree of the tumor responses, these results are superior to other low molecular weight inhibitors, such as epidermal growth factor receptor (EGFR) inhibitors. As glioma xenografts often grow without invasion, these results may underestimate the efficacy of targeting FAK as FAK plays a major role in tumor invasion. Conclusion: TAE226 demonstrates modest activity as monotherapy against malignant gliomas and warrants further investigation, potentially in combination with other therapies.

[Table: see text]

Regulated release of VWF and FVIII and the biologic implications

von Willebrand factor (VWF) performs a critical function in platelet binding at the site of vascular injury and also serves as the carrier protein for coagulation factor FVIII (FVIII), protecting it from proteolytic degradation in plasma. Both proteins undergo rapid, regulated release in response to DDAVP administration in patients with mild hemophilia A or von Wille-brand disease. Here, we attempt to summarize our current understanding of the establishment of the regulated storage pool of VWF and FVIII. The data presented indicate that regulated secretion of both proteins occurs only if there is endogenous synthesis of FVIII together with VWF.

Characterization and application of two novel monoclonal antibodies against human OX40: costimulation of T cells and expression on tumor as well as normal gland tissues

OX40, a membrane-bound molecule of the tumor-necrosis-factor-receptor superfamily, is a critical costimulatory receptor during the immune response. Here, we newly generated two specific mouse antihuman OX40 monoclonal antibodies (mAbs) (2G2 and 1F7), whose specificities are quite different from the available OX40 mAb (ACT35) by competition assay. It was also found that both mAbs could enhance the proliferation, activation and differentiation of T lymphocytes primed by anti-CD3 mAb. These results evidenced that both were functional antihuman OX40 mAbs. Furthermore, stained by 2G2 and 1F7, FCM and immunohistochemistry detected the constitutive expression of OX40 on tumor cell lines from epithelium, breast cancer and glioma tissues. Meanwhile, the non-tumor tissues (thyroid gland, stomach gland) were also found OX40 expression. These results suggested that OX40 is not only expressed in activated T cells, but also in some tumors as well as normal gland tissues. Such expression pattern indicated that OX40 may be a valuable surface antigen in unveiling its expression and function outside the immune system. Briefly, these novel antibodies may contribute to the evaluation of the mechanism of tumor metastasis and eventually shed light on further study of tumor immunotherapy and autoimmune diseases.

Reticulon proteins: emerging players in neurodegenerative diseases

Reticulons (RTNs) are a group of integral membrane proteins that have a uniquely conserved C-terminal domain named RHD. In mammalian genomes, transcripts are produced from four genes, rtn1 to rtn4, under the regulation of tissue or cell-type-specific expression. The presence of alternative promoters for gene expression and multiple cryptic splicing sites have resulted in large numbers of genes/proteins that are classified among the reticulon family. Although this family exists in almost all eukaryotes, only the rtn4 gene product, Nogo (RTN4), has gained relatively more in-depth attention. Despite predominant localization in the endoplasmic reticulum, Nogo on the cell surface appears to play a critical role as an inhibitory molecule for axonal growth and regeneration in humans and rodents. Recently, studies have expanded the biological functions of RTNs to other facets including modulating the enzymatic activity of beta-secretase in Alzheimer's disease. In this review, we summarize the accumulated findings concerning the structural and functional aspects of RTNs and speculate on their linkage to the pathogenesis of neurodegenerative diseases.

Characterization and application of two novel monoclonal antibodies against 2IgB7-H3: expression analysis of 2IgB7-H3 on dendritic cells and tumor cells

2IgB7-H3 has recently been identified as a new member of the B7 family. Its expression at the protein level remains largely unknown due to the lack of the specific monoclonal antibody (mAb). To characterize the expression of 2IgB7-H3, we newly generated two mouse antihuman 2IgB7-H3 mAbs (4H7 and 21D4). We found the constitutive expression of 2IgB7-H3 on a series of tumor cell lines. Furthermore, the expression was examined on monocyte-derived dendritic cells (Mo-DCs) and DCs from CD34(+) hematopoietic progenitor cells (HPC) by means of mAb staining. The results showed that 2IgB7-H3 was expressed on Mo-DCs at a high and stable level during differentiation in vitro. With the maturation of DCs from CD34(+) HPCs, the expression of the molecule was upregulated. However, the 2IgB7-H3 was not expressed on fresh isolated T and B lymphocytes, monocytes, or CD34(+) HPCs. These results suggested that 2IgB7-H3 may be a valuable surface antigen for the detection of DCs.

Driver landmark and traffic sign identification in early Alzheimer's disease

OBJECTIVE

To assess visual search and recognition of roadside targets and safety errors during a landmark and traffic sign identification task in drivers with Alzheimer's disease.

METHODS

33 drivers with probable Alzheimer's disease of mild severity and 137 neurologically normal older adults underwent a battery of visual and cognitive tests and were asked to report detection of specific landmarks and traffic signs along a segment of an experimental drive.

RESULTS

The drivers with mild Alzheimer's disease identified significantly fewer landmarks and traffic signs and made more at-fault safety errors during the task than control subjects. Roadside target identification performance and safety errors were predicted by scores on standardised tests of visual and cognitive function.

CONCLUSIONS

Drivers with Alzheimer's disease are impaired in a task of visual search and recognition of roadside targets; the demands of these targets on visual perception, attention, executive functions, and memory probably increase the cognitive load, worsening driving safety.

Driver route-following and safety errors in early Alzheimer disease

OBJECTIVE

To assess navigation and safety errors during a route-following task in drivers with Alzheimer disease (AD).

DESIGN/METHODS

Thirty-two subjects with probable AD (by National Institute of Neurological and Communicative Disorders criteria) of mild severity and 136 neurologically normal older adults were tested on a battery of visual and cognitive tests of abilities that are critical to safe automobile driving. Each driver also performed a route-finding task administered on the road in an instrumented vehicle. Main outcome variables were number of 1) incorrect turns; 2) times lost; and 3) at-fault safety errors.

RESULTS

The drivers with mild AD made significantly more incorrect turns, got lost more often, and made more at-fault safety errors than control subjects, although their basic vehicular control abilities were normal. The navigational and safety errors were predicted using scores on standardized tests sensitive to visual and cognitive decline in early AD.

CONCLUSIONS

Drivers with Alzheimer disease made more errors than neurologically normal drivers on a route-following task that placed demands on driver memory, attention, and perception. The demands of following route directions probably increased the cognitive load during driving, which might explain the higher number of safety errors.

Subchondral and trabecular bone metabolism regulation in canine experimental knee osteoarthritis

OBJECTIVE

To determine trabecular and subchondral bone metabolic changes in experimental canine osteoarthritis (OA).

METHODS

OA was induced in 19 dogs by transection of the anterior cruciate ligament (ACL) of the right knee through a stab wound. Dogs were sacrificed at 8 (n=7) and 12 weeks (n=12) after surgery. Non-operated normal dogs (n=6) were used as controls. After sacrifice, samples were obtained from the weight-bearing area of medial tibial plateaus. Explants and cell cultures were prepared from subchondral and trabecular bone. Osteocalcin (Oc), cellular alkaline phosphatase (ALPase), urokinase plasminogen-activator (uPA), prostaglandin E2 (PGE2), metalloproteinase (MMP) and nitric oxide (NO) were measured using standard procedures.

RESULTS

ALPase production was significantly increased only at week 12 in subchondral and trabecular bone, while an increase in Oc was noted at week 8. uPA and MMP activity were increased significantly at week 12 in subchondral bone, while PGE2 levels were significantly higher in subchondral and trabecular bone at week 12 compared to normal. A decrease in NO production appeared late at week 12 in trabecular bone, whereas NO levels from subchondral bone were significantly increased compared to normal at week 8.

DISCUSSION

Intense bone remodeling takes place in both subchondral and trabecular bone in the knee following ACL transection. This process seems to occur around week 12, although Oc and NO appeared to be involved earlier at 8 weeks. These results suggest that not only subchondral but also trabecular bone metabolism is altered in this OA model.

Molecular mechanisms of action and prediction of response to oxaliplatin in colorectal cancer cells

The platinum compound oxaliplatin has been shown to be an effective chemotherapeutic agent for the treatment of colorectal cancer. In this study, we investigate the molecular mechanisms of action of oxaliplatin to identify means of predicting response to this agent. Exposure of colon cancer cells to oxaliplatin resulted in G2/M arrest and apoptosis. Immunofluorescent staining demonstrated that the apoptotic cascade initiated by oxaliplatin is characterised by translocation of Bax to the mitochondria and cytochrome c release into the cytosol. Oxaliplatin treatment resulted in caspase 3 activation and oxaliplatin-induced apoptosis was abrogated by inhibition of caspase activity with z-VAD-fmk, but was independent of Fas/FasL association. Targeted inactivation of Bax or p53 in HCT116 cells resulted in significantly increased resistance to oxaliplatin. However, the mutational status of p53 was unable to predict response to oxaliplatin in a panel of 30 different colorectal cancer cell lines. In contrast, the expression profile of these 30 cell lines, assessed using a 9216-sequence cDNA microarray, successfully predicted the apoptotic response to oxaliplatin. A leave-one-out cross-validation approach was used to demonstrate a significant correlation between experimentally observed and expression profile predicted apoptosis in response to clinically achievable doses of oxaliplatin (R=0.53; P=0.002). In addition, these microarray experiments identified several genes involved in control of apoptosis and DNA damage repair that were significantly correlated with response to oxaliplatin.