Enhancement of YBCO thin film thermal stability under 1 ATM oxygen pressure by intermediate Cu2O nanolayer

The melting process of YBa(2)Cu(3)O(x) (YBCO or Y123) films under an oxygen atmosphere was observed in situ by means of high-temperature optical microscopy. The films were classified by pole figure measurement as c-axis oriented, with two different in-plane orientations (denoted as 0 and 45 degrees). In the 45 degrees-oriented films, electron diffraction and high-resolution transmission electron microscopy (HRTEM) detected an intermediate Cu(2)O nanolayer in the vicinity of the interface. The melting mode and the thermal stability of the YBCO thin films with different in-plane orientations were greatly influenced by oxygen partial pressure. Notably, the thermal stability of the 45 degrees-oriented YBCO films dramatically grew with increasing oxygen partial pressure. We attributed this effect to a change in the intermediate Cu(2)O nanolayer thermal stability. We conclude and suggest that the thermal stability of YBCO films can be significantly enhanced by inserting a Cu(2)O buffer nanolayer.

Selectivity of lynx proteins on insect nicotinic acetylcholine receptors in the brown planthopper, Nilaparvata lugens

Neuronal nicotinic acetylcholine receptors (nAChRs) are major excitatory neurotransmitter receptors in both vertebrates and invertebrates. Two lynx proteins (Nl-lynx1 and Nl-lynx2) have been identified in the brown planthopper, Nilaparvata lugens, which act as modulators on insect nAChRs. In the present study, two lynx proteins were found to act on the triplet receptor Nlalpha1/Nlalpha2/beta2 expressed in Xenopus oocytes, increasing agonist-evoked macroscopic currents, but not changing agonist sensitivity and desensitization properties. Nl-lynx1 and Nl-lynx2 increased I(max) (maximum responses) of acetylcholine to 4.85-fold and 2.40-fold of that of Nlalpha1/Nlalpha2/beta2 alone, and they also increased I(max) of imidacloprid to 2.57-fold and 1.25-fold. Although, on another triplet nAChRs Nlalpha3/Nlalpha8/beta2, Nl-lynx2 increased I(max) of acetylcholine and imidacloprid to 3.63-fold and 2.16-fold, Nl-lynx1 had no effects on I(max) of either acetylcholine or imidacloprid. The results demonstrate the selectivity of lynx proteins for different insect nAChR subtypes. This selectivity was also identified in native N. Lugens. Co-immunoprecipitation was found between Nlalpha1/Nlalpha2-containing receptors and both Nl-lynx1 and Nl-lynx2, but was only found between Nlalpha3/Nlalpha8-containing receptors and Nl-lynx2. When the previously identified Nlalpha1(Y151S) and Nlalpha3(Y151S) mutations were included (Nlalpha1(Y151S)/Nlalpha2/beta2 and Nlalpha3(Y151S)/Nlalpha8/beta2), the increase in I(max) of imidacloprid, but not acetylcholine, caused by co-expression of Nl-lynx1 and Nl-lynx2 was more noticeable than that of their wildtype counterparts. Taken together, these data suggest that two modulators, Nl-lynx1 and Nl-lynx2, might serve as an influencing factor in target site insensitivity in N. lugens, such as Y151S mutation.

Pharmacokinetics of methyl protodioscin in rats

Methyl protodioscin (MPD), a natural furostanol saponin, showed distinct antitumor activity and is distributed in many traditional Chinese medicines. The pharmacokinetics, distribution and excretion of MPD were first investigated after i.v. injection to rats in this study. The dose-dependent pharmacokinetics of MPD were characterized after i.v. injection (20, 40 and 120 mg/kg of MPD) to rats. A good linearity (r = 0.9989, P < 0.05) was found in the regression analysis of the AUC0-t -dose. The plasma concentrations of MPD declined rapidly with an elimination half-life (t1/2) from 25.56 to 29.32 min. The MPD kinetics was in line with one-compartment model after i.v. injection. 23.43% and 32.86% of MPD was recovered in urine and bile, respectively. The concentrations of MPD in plasma and most examined tissues 5 h after injection were close to or below the Low Limit of Quantification (LLOQ). This indicated that MPD was distributed and eliminated rapidly in rats.

Systemic administration of a PEGylated adenovirus vector with a cancer-specific promoter is effective in a mouse model of metastasis

Cancer gene therapy by adenovirus vectors (Advs) for metastatic cancer is limited because systemic administration of Adv produces low therapeutic effect and severe side effects. In this study, we generated a dual cancer-specific targeting vector system by using PEGylation and the telomere reverse transcriptase (TERT) promoter and attempted to treat experimental metastases through systemic administration of the vectors. We first optimized the molecular size of PEG and modification ratios used to create PEG-Ads. Systemic administration of PEG-Ad with 20-kDa PEG at a 45% modification ratio (PEG[20K/45%]-Ad) resulted in higher tumor-selective transgene expression than unmodified Adv. Next, we examined the effectiveness against metastases and side effects of a TERT promoter-driven PEG[20K/45%]-Ad containing the herpes simplex virus thymidine kinase (HSVtk) gene (PEG-Ad-TERT/HSVtk). Systemic administration of PEG-Ad-TERT/HSVtk showed superior antitumor effects against metastases with negligible side effects. A cytomegalovirus (CMV) promoter-driven PEG[20K/45%]-Ad also produced antimetastatic effects, but these were accompanied by side effects. Combining PEG-Ad-TERT/HSVtk with etoposide or 5-fluorouracil enhanced the therapeutic effects with negligible side effects. These results suggest that modification with 20-kDa PEG at a 45% modification ratio is the optimal condition for PEGylation of Adv, and PEG-Ad-TERT/HSVtk is a prototype Adv for systemic cancer gene therapy against metastases.

Pharmacological characterization of cis-nitromethylene neonicotinoids in relation to imidacloprid binding sites in the brown planthopper, Nilaparvata lugens

Neonicotinoid insecticides, such as imidacloprid, are selective agonists of the insect nicotinic acetylcholine receptors (nAChRs) and extensively used in areas of crop protection and animal health to control a variety of insect pest species. Here we describe that two cis-nitromethylene neonicotinoids (IPPA152002 and IPPA152004), recently synthesized in our laboratory, discriminated between the high and low affinity imidacloprid binding sites in the brown planthopper, Nilaparvata lugens, a major insect pest of rice crops in many parts of Asia. [(3)H]imidacloprid has two binding sites with different affinities (Kd value of 0.0035 +/- 0.0006 nM for the high-affinity site and 1.47 +/- 0.22 nM for the low-affinity site). Although the cis-nitromethylene neonicotinoids showed low displacement ability (Ki values of 0.15 +/- 0.03 microM and 0.42 +/- 0.07 microM for IPPA152002 and IPPA152004, respectively) against [(3)H]imidacloprid binding, low concentrations (0.01 microM) of IPPA152002 completely inhibited [(3)H]imidacloprid binding at its high-affinity site. In Xenopus oocytes co-injected with cRNA encoding Nlalpha1 and rat beta2 subunits, obvious inward currents were detected in response to applications of IPPA152002 and IPPA152004, although the agonist potency is reduced to that of imidacloprid. The previously identified Y151S mutation in Nlalpha1 showed significant effects on the agonist potency of IPPA152002 and IPPA152004, such as a 75.8% and 70.6% reduction in Imax, and a 2.4- and 2.1-fold increase in EC(50). This data clearly shows that the two newly described cis-nitromethylene neonicotinoids act on insect nAChRs and like imidacloprid, discriminated between high and low affinity binding sites in N. lugens native nAChRs. These compounds may be useful tools to further elucidate the pharmacology and nature of neonicotinoid binding sites.

Raloxifene protects endothelial cell function against oxidative stress

BACKGROUND AND PURPOSE

Maintaining a delicate balance between the generation of nitric oxide (NO) and removal of reactive oxygen species (ROS) within the vascular wall is crucial to the physiological regulation of vascular tone. Increased production of ROS reduces the effect and/or bioavailability of NO, leading to an impaired endothelial function. This study tested the hypothesis that raloxifene, a selective oestrogen receptor modulator, can prevent endothelial dysfunction under oxidative stress.

EXPERIMENTAL APPROACH

Changes in isometric tension were measured in rat aortic rings. The content of cyclic GMP in aortic tissue was determined by radioimmunoassay. Phosphorylation of endothelial NOS (eNOS) and Akt was assayed by Western blot analysis.

KEY RESULTS

In rings with endothelium, ACh-induced relaxations were attenuated by a ROS-generating reaction (hypoxanthine plus xanthine oxidase, HXXO). The impaired relaxations were ameliorated by acute treatment with raloxifene. HXXO suppressed the ACh-stimulated increase in cyclic GMP levels; this effect was antagonized by raloxifene. The improved endothelial function by raloxifene was abolished by ICI 182,780, and by wortmannin or LY294002. Raloxifene also protected endothelial cell function against H2O2. Raloxifene increased the phosphorylation of eNOS at Ser-1177 and Akt at Ser-473; this effect was blocked by ICI 182,780. Finally, raloxifene was not directly involved in scavenging ROS, and neither inhibited the activity of xanthine oxidase nor stimulated that of superoxide dismutase.

CONCLUSION AND IMPLICATIONS

Raloxifene is effective against oxidative stress-induced endothelial dysfunction in vitro through an ICI 182,780-sensitive mechanism that involves the increased phosphorylation and activity of Akt and eNOS in rat aortae.

Interventions for enhancing medication adherence

BACKGROUND

People who are prescribed self-administered medications typically take less than half the prescribed doses. Efforts to assist patients with adherence to medications might improve the benefits of prescribed medications, but also might increase their adverse effects.

OBJECTIVES

To update a review summarizing the results of randomized controlled trials (RCTs) of interventions to help patients follow prescriptions for medications for medical problems, including mental disorders but not addictions.

SEARCH STRATEGY

We updated searches of The Cochrane Library, MEDLINE, CINAHL, EMBASE, International Pharmaceutical Abstracts (IPA), PsycINFO (all via OVID) and Sociological Abstracts (via CSA) in January 2007 with no language restriction. We also reviewed bibliographies in articles on patient adherence and articles in our personal collections, and contacted authors of relevant original and review articles.

SELECTION CRITERIA

Articles were selected if they reported an unconfounded RCT of an intervention to improve adherence with prescribed medications, measuring both medication adherence and treatment outcome, with at least 80% follow-up of each group studied and, for long-term treatments, at least six months follow-up for studies with positive initial findings.

DATA COLLECTION AND ANALYSIS

Study design features, interventions and controls, and results were extracted by one review author and confirmed by at least one other review author. We extracted adherence rates and their measures of variance for all methods of measuring adherence in each study, and all outcome rates and their measures of variance for each study group, as well as levels of statistical significance for differences between study groups, consulting authors and verifying or correcting analyses as needed. The studies differed widely according to medical condition, patient population, intervention, measures of adherence, and clinical outcomes. Therefore, we did not feel that quantitative analysis was scientifically justified; rather, we conducted a qualitative analysis.

MAIN RESULTS

For short-term treatments, four of ten interventions reported in nine RCTs showed an effect on both adherence and at least one clinical outcome, while one intervention reported in one RCT significantly improved patient adherence, but did not enhance the clinical outcome. For long-term treatments, 36 of 81 interventions reported in 69 RCTs were associated with improvements in adherence, but only 25 interventions led to improvement in at least one treatment outcome. Almost all of the interventions that were effective for long-term care were complex, including combinations of more convenient care, information, reminders, self-monitoring, reinforcement, counseling, family therapy, psychological therapy, crisis intervention, manual telephone follow-up, and supportive care. Even the most effective interventions did not lead to large improvements in adherence and treatment outcomes.

AUTHORS' CONCLUSIONS

For short-term treatments several quite simple interventions increased adherence and improved patient outcomes, but the effects were inconsistent from study to study with less than half of studies showing benefits. Current methods of improving adherence for chronic health problems are mostly complex and not very effective, so that the full benefits of treatment cannot be realized. High priority should be given to fundamental and applied research concerning innovations to assist patients to follow medication prescriptions for long-term medical disorders.

Interventions for enhancing medication adherence

BACKGROUND

People who are prescribed self-administered medications typically take less than half the prescribed doses. Efforts to assist patients with adherence to medications might improve the benefits of prescribed medications, but also might increase their adverse effects.

OBJECTIVES

To update a review summarizing the results of randomized controlled trials (RCTs) of interventions to help patients follow prescriptions for medications for medical problems, including mental disorders but not addictions.

SEARCH STRATEGY

We updated searches of The Cochrane Library, MEDLINE, CINAHL, EMBASE, International Pharmaceutical Abstracts (IPA), PsycINFO (all via OVID) and Sociological Abstracts (via CSA) in January 2007 with no language restriction. We also reviewed bibliographies in articles on patient adherence and articles in our personal collections, and contacted authors of relevant original and review articles.

SELECTION CRITERIA

Articles were selected if they reported an unconfounded RCT of an intervention to improve adherence with prescribed medications, measuring both medication adherence and treatment outcome, with at least 80% follow-up of each group studied and, for long-term treatments, at least six months follow-up for studies with positive initial findings.

DATA COLLECTION AND ANALYSIS

Study design features, interventions and controls, and results were extracted by one review author and confirmed by at least one other review author. We extracted adherence rates and their measures of variance for all methods of measuring adherence in each study, and all outcome rates and their measures of variance for each study group, as well as levels of statistical significance for differences between study groups, consulting authors and verifying or correcting analyses as needed. The studies differed widely according to medical condition, patient population, intervention, measures of adherence, and clinical outcomes. Therefore, we did not feel that quantitative analysis was scientifically justified; rather, we conducted a qualitative analysis.

MAIN RESULTS

For short-term treatments, four of ten interventions reported in nine RCTs showed an effect on both adherence and at least one clinical outcome, while one intervention reported in one RCT significantly improved patient adherence, but did not enhance the clinical outcome. For long-term treatments, 36 of 81 interventions reported in 69 RCTs were associated with improvements in adherence, but only 25 interventions led to improvement in at least one treatment outcome. Almost all of the interventions that were effective for long-term care were complex, including combinations of more convenient care, information, reminders, self-monitoring, reinforcement, counseling, family therapy, psychological therapy, crisis intervention, manual telephone follow-up, and supportive care. Even the most effective interventions did not lead to large improvements in adherence and treatment outcomes.

AUTHORS' CONCLUSIONS

For short-term treatments several quite simple interventions increased adherence and improved patient outcomes, but the effects were inconsistent from study to study with less than half of studies showing benefits. Current methods of improving adherence for chronic health problems are mostly complex and not very effective, so that the full benefits of treatment cannot be realized. High priority should be given to fundamental and applied research concerning innovations to assist patients to follow medication prescriptions for long-term medical disorders.

The methylation pattern of p16INK4a gene promoter in psoriatic epidermis and its clinical significance

BACKGROUND

Alteration of the p16INK4a gene by epigenetic changes has been described in some hyperproliferative skin diseases, but its importance in psoriasis has not yet been established.

OBJECTIVES

To investigate the methylation status of the p16INK4a gene in psoriatic epidermis, its clinical significance and the possible epigenetic mechanisms of psoriasis.

METHODS

DNA and RNA specimens were obtained from the lesional epidermis of 56 patients with plaque psoriasis. Methylation-specific polymerase chain reaction (PCR) and DNA sequencing were used to detect the density and sites of methylation in the p16INK4a promoter region. The reverse transcription-PCR technique was applied to detect the mRNA expression of p16INK4a.

RESULTS

p16INK4a gene promoter methylation was shown in 17 of 56 (30%) patients with psoriasis. Psoriasis Area and Severity Index scores in patients showing methylation were higher than in those who did not (P<0.05). The mRNA expression level of p16INK4a in the methylated group was significantly lower than in the unmethylated group (t=2.515, P=0.015). In the methylated group, about 50% of the CpG islands were methylated in the promoter region.

CONCLUSIONS

Overall, methylation of the p16INK4a gene promoter is found in psoriatic epidermis, which is associated with the mRNA level of p16INK4a expression and activity of the disease. These data indicate that methylation of the p16INK4a promoter may play a potential role in the pathogenesis of psoriasis.

The mitotic checkpoint kinase NEK2A regulates kinetochore microtubule attachment stability

Loss or gain of whole chromosome, the form of chromosome instability commonly associated with cancers is thought to arise from aberrant chromosome segregation during cell division. Chromosome segregation in mitosis is orchestrated by the interaction of kinetochores with spindle microtubules. Our studies show that NEK2A is a kinetochore-associated protein kinase essential for faithful chromosome segregation. However, it was unclear how NEK2A ensures accurate chromosome segregation in mitosis. Here we show that NEK2A-mediated Hec1 (highly expressed in cancer) phosphorylation is essential for faithful kinetochore microtubule attachments in mitosis. Using phospho-specific antibody, our studies show that NEK2A phosphorylates Hec1 at Ser165 during mitosis. Although such phosphorylation is not required for assembly of Hec1 to the kinetochore, expression of non-phosphorylatable mutant Hec1(S165) perturbed chromosome congression and resulted in a dramatic increase in microtubule attachment errors, including syntelic and monotelic attachments. Our in vitro reconstitution experiment demonstrated that Hec1 binds to microtubule in low affinity and phosphorylation by NEK2A, which prevents aberrant kinetochore-microtubule connections in vivo, increases the affinity of the Ndc80 complex for microtubules in vitro. Thus, our studies illustrate a novel regulatory mechanism in which NEK2A kinase operates a faithful chromosome attachment to spindle microtubule, which prevents chromosome instability during cell division.

Store-operated calcium entry in vascular smooth muscle

In non-excitable cells, activation of G-protein-coupled phospholipase C (PLC)-linked receptors causes the release of Ca(2+) from intracellular stores, which is followed by transmembrane Ca(2+) entry. This Ca(2+) entry underlies a small and sustained phase of the cellular [Ca(2+)](i) increases and is important for several cellular functions including gene expression, secretion and cell proliferation. This form of transmembrane Ca(2+) entry is supported by agonist-activated Ca(2+)-permeable ion channels that are activated by store depletion and is referred to as store-operated Ca(2+) entry (SOCE) and represents a major pathway for agonist-induced Ca(2+) entry. In excitable cells such as smooth muscle cells, Ca(2+) entry mechanisms responsible for sustained cellular activation are normally considered to be mediated via either voltage-operated or receptor-operated Ca(2+) channels. Although SOCE occurs following agonist activation of smooth muscle, this was thought to be more important in replenishing Ca(2+) stores rather than acting as a source of activator Ca(2+) for the contractile process. This review summarizes our current knowledge of SOCE as a regulator of vascular smooth muscle tone and discusses its possible role in the cardiovascular function and disease. We propose a possible hypothesis for its activation and suggest that SOCE may represent a novel target for pharmacological therapeutic intervention.

Functional characterization of TIP60 sumoylation in UV-irradiated DNA damage response

The histone acetyltransferase TIP60 regulates the DNA damage response following genotoxic stress by acetylating histone and remodeling chromatin. However, the molecular mechanisms underlying the TIP60-dependent response to UV-induced DNA damage remain poorly understood. To systematically analyse proteins that regulate TIP60 activity in response to UV irradiation, we performed a proteomic analysis of proteins selectively bound to TIP60 in response to UV irradiation using mass spectrometry and identified a novel regulatory mechanism by which TIP60 orchestrates transcriptional activation of p53-dependent checkpoint response in UV-irradiated cells. The initial step of this pathway involves UV-induced association of TIP60 with SUMO-conjugation enzymes and site-specific sumoylation of TIP60 at lysines 430 and 451 via Ubc9. This sumoylation initiates the relocation of TIP60 from nucleoplasm to the promyelocytic leukemia body, which is essential for the UV-irradiated DNA damage repair response via a p53-dependent pathway. Significantly, inhibition of TIP60 sumoylation by overexpression of non-sumoylatable mutant abrogates the p53-dependent DNA damage response, demonstrating the importance of TIP60 sumoylation in response to UV irradiation. Our biochemical characterization demonstrated that the sumoylation of TIP60 augments its acetyltransferase activity in vitro and in vivo. Thus, this study shed new light on the function and regulation of TIP60 activity in UV-irradiated DNA damage response.

Effect sizes can be calculated for studies reporting ranges for outcome variables in systematic reviews

OBJECTIVE

To develop a method by which studies reporting the ranges (or maxima and minima) of observed outcomes can be included in systematic reviews, along with other studies reporting in the more usual way by using standard deviations (SDs).

STUDY DESIGN AND SETTING

An approach is proposed to allow a numerical conversion of a reported range from a continuous outcome into an equivalent SD.

RESULTS

The SD is estimated from the observed range times an appropriate conversion factor. Two examples (the first concerning a patient education program on adherence to drug treatment for rheumatoid arthritis, and the second investigating if cognitive behavior therapy could improve adherence to antiretroviral therapy and then lead to suppression of human immunodeficiency virus replication) demonstrate the calculations.

CONCLUSION

This note provides a simple method to allow studies that report outcome variability in terms of ranges to be included in systematic reviews by conversion to equivalent SDs. The method is entirely valid if the outcome variable is normally distributed, but for nonnormal data, some caution may be needed.

Therapeutic concentrations of raloxifene augment nitric oxide-dependent coronary artery dilatation in vitro

BACKGROUND AND PURPOSE

Raloxifene improves cardiovascular function. This study examines the hypothesis that therapeutic concentrations of raloxifene augment endothelium-dependent relaxation via up-regulation of eNOS expression and activity in porcine coronary arteries.

EXPERIMENTAL APPROACH

Isometric tension was measured in rings from isolated arteries. Intracellular Ca(2+) concentrations ([Ca(2+)](i)) in arterial endothelial cells were detected by Ca(2+) fluorescence imaging. Phosphorylation of eNOS at Ser-1177 was assayed by Western blot analysis.

KEY RESULTS

In arterial rings pre-contracted with 9,11-dideoxy-11alpha,9alpha-epoxy-methano-prostaglandin F(2alpha) (U46619), treatment with raloxifene (1-3 nM) augmented bradykinin- or substance P-induced relaxation and this effect was antagonized by ICI 182,780, an estrogen receptor antagonist. The enhanced relaxation was abolished in rings treated with inhibitors of nitric oxide/cyclic GMP-dependent dilation, N(G)-nitro-L-arginine methyl ester (L-NAME) plus 1H-[1,2,4]oxadizolo[4,3-a]quinoxalin-1-one (ODQ). In contrast, effects of raloxifene were unaffected after inhibition of endothelium-derived hyperpolarizing factors by charybdotoxin plus apamin. Raloxifene (3 nM) did not influence endothelium-independent relaxation to sodium nitroprusside. 17beta-Estradiol (3-10 nM) also enhanced bradykinin-induced relaxation, which was inhibited by ICI 182,780. Treatment with raloxifene (3 nM) did not affect bradykinin-stimulated rise in endothelial cell [Ca(2+)](i). Raloxifene, 17beta-estradiol, and bradykinin increased eNOS phosphorylation at Ser-1177 and ICI 182,780 prevented effects of raloxifene or 17beta-estradiol but not that of bradykinin. Raloxifene had neither additive nor antagonistic effects on 17beta-estradiol-induced eNOS phosphorylation.

CONCLUSIONS AND IMPLICATIONS

Raloxifene in therapeutically relevant concentrations augmented endothelial function in porcine coronary arteries in vitro through ICI 182,780-sensitive mechanisms that were associated with increased phosphorylation of eNOS but independent of changes in endothelial cell [Ca(2+)](i).

BM stem cell transplantation rescues pathophysiologic features of aged dystrophic mdx muscle

BACKGROUND

The value of transplantation of BM stem cells in aged (12-month-old) mdx was evaluated because it is thought to be a more ideal model for studying the praxiology of Duchenne muscular dystrophy (DMD). The possible mechanisms of stem cell differentiation were then discussed.

METHODS

BM was isolated from 8-10-week-old male C57 BL/10 mice. After injecting BM cells into 12-month-old female mdx mice through the tail vein, the expression of dystrophin and MyoD was detected at different time points by immunofluorescence staining, RT-PCR and Western blot.

RESULTS

The C57 male mice donor-specific and Y-chromosome-specific sequence could be detected in all female aged mdx mice, implying the success of the transplantation. Expression of dystrophin and MyoD was detected and increased over time.

DISCUSSION

BM cells were recruited to the muscle and partially restored specific pathophysiologic features of the dystrophic muscle in aged mdx mice. Muscle differentiation of BM cells recapitulated embryonic myogenesis.

Identification of deregulated oncogenic pathways in renal cell carcinoma: an integrated oncogenomic approach based on gene expression profiling

In this age of targeted therapy, identification of molecular pathways that are deregulated in cancer will not only elucidate underlying tumorigenic mechanisms, but may also help to determine the classes of drugs that are used for treatment. In kidney cancer, a spectrum of histological subtypes exists that are characterized both by distinct molecular signatures and increasingly by distinct molecular pathways that are deregulated in each subtype. For example, the VHL/hypoxia pathway is well-known to be deregulated in clear cell renal cell carcinoma (RCC) whereas in papillary RCC activation of the HGF/Met pathway has been implicated. Additional molecular pathways, many not yet identified, may also be involved in the development of the different histologic subtypes. Moreover, differences in pathway activation may reflect differences in tumor progression and response to treatment. In this article, we describe an oncogenomic approach, based on integrative analysis of gene expression profiling data. In this approach, gene expression data is used to identify both cytogenetic abnormalities and molecular pathways that are deregulated in RCC. Ideally, predicted pathway abnormalities can be linked to predicted cytogenetic abnormalities to identify likely candidate genes. Although further cellular and functional studies are warranted to validate the computational models, development of such models in RCC have the potential to open up new avenues of molecular research and may have significant diagnostic and therapeutic implications.