Are strong opioids equally effective and safe in the treatment of chronic cancer pain? A multicenter randomized phase IV 'real life' trial on the variability of response to opioids.

BACKGROUND: Guidelines tend to consider morphine and morphine-like opioids comparable and interchangeable in the treatment of chronic cancer pain, but individual responses can vary. This study compared the analgesic efficacy, changes of therapy and safety profile over time of four strong opioids given for cancer pain. PATIENT AND METHODS: In this four-arm multicenter, randomized, comparative, of superiority, phase IV trial, oncological patients with moderate to severe pain requiring WHO step III opioids were randomly assigned to receive oral morphine or oxycodone or transdermal fentanyl or buprenorphine for 28 days. At each visit, pain intensity, modifications of therapy and adverse drug reactions (ADRs) were recorded. The primary efficacy end point was the proportion of nonresponders, meaning patients with worse or unchanged average pain intensity (API) between the first and last visit, measured on a 0-10 numerical rating scale. (NCT01809106). RESULTS: Forty-four centers participated in the trial and recruited 520 patients. Worst pain intensity and API decreased over 4 weeks with no significant differences between drugs. Nonresponders ranged from 11.5% (morphine) to 14.4% (buprenorphine). Appreciable changes were made in the treatment schedules over time. Each group required increases in the daily dose, from 32.7% (morphine) to 121.2% (transdermal fentanyl). Patients requiring adjuvant analgesics ranged from 68.9% (morphine) to 81.6% (oxycodone), switches varied from 22.1% (morphine) to 12% (oxycodone), discontinuation of treatment from 27% ( morphine) to 14.5% (fentanyl). ADRs were similar except for effects on the nervous system, which significantly prevailed with morphine. CONCLUSION: The main findings were the similarity in pain control, response rates and main adverse reactions among opioids. Changes in therapy schedules were notable over time. A considerable proportion of patients were nonresponders or poor responders. CLINICAL TRIAL REGISTRATION: NCT01809106 (https://clinicaltrials.gov/ct2/show/NCT01809106?term=cerp&rank=2).

Diagnostic delay and prognosis in primary central nervous system lymphoma compared with glioblastoma multiforme.

Glioblastoma multiforme (GBM) and primary central nervous system lymphoma (PCNSL) are malignant cerebral neoplasms associated with poor prognosis. Early diagnosis and subsequent planning of adequate treatment strategy are relevant to improve survival and reduce neurological deficit. Two groups of patients affected by GBM and PCNSL were compared to identify: (1) factors influencing the time necessary to obtain a correct diagnosis; (2) the influence of the interval time from clinical onset to diagnosis on the prognosis. Fifty-six patients (28 PCNSL and 28 GBM, 23 females and 33 males) referred to the same hospital setting were retrospectively evaluated. The mean age at diagnosis was 61 years. The two groups were comparable in terms of age, sex, clinical symptoms at onset and performance status. There was no relevant difference in time span from clinical onset to first neuroimaging examination, while time span from first neuroimaging to final morphological diagnosis was much longer in PCNSL patients (p = 0.008). Multivariate Cox regression analysis, including both PCNSL and GBM cases, showed a significant association of the overall survival with: time to diagnosis (HR 0.06), age at onset (HR 1.04). Our results show a significant diagnostic delay in PCNSL cases. Age at onset of disease and time to diagnosis emerge as clinical factors affecting overall survival in both groups. Stereotactic-guided biopsy should be chosen as routine method to early diagnose PCNSL. The clinical relevance of early diagnosis in GBM and PCNSL needs to be emphasized to maximize the overall survival in both neoplasms.

Assessing the response to opioids in cancer patients: a methodological proposal and the results.

PURPOSE: The efficacy of treatment with opioids in cancer pain is variable. To evaluate this variability, we (1) applied two parameters, changes in pain intensity (PI) and opioid daily doses (DDs), to distinguish different responses to opioids. The need to switch to another opioid was recorded. We then (2) evaluated the distribution of the responses depending on these parameters, alone and taken together, in cancer patients with pain. METHODS: The cutoffs between positive and negative responses related to PI and DD were defined on the basis of the literature. For PI, responders were patients who obtained simultaneously a decrease of 30% or more and a final score ≤4 points (numerical rating scale 0 to 10). For DD changes, we applied the opioid escalation index percentage, a positive response corresponding to a dose increase ≤5%. These criteria were applied to 201 cancer patients treated with WHO step III "strong" opioids for 21 days. The results were mainly analyzed case by case. RESULTS: Of the patients, 63.7% obtained a positive analgesic response and 80.1% a dose-related positive response. Combining the parameters, the response was double positive in 55.2% of cases, double negative in 11.4%, a good analgesic response with a large dose escalation in 8.5%, and no pain relief with a stable dose in 24.9%. Switches were made 21 times, 15 because of the lack of analgesia. CONCLUSIONS: Different degrees of response to opioids were observed, PI and DD changes both contributing. Only over half the patients had a full positive response.

Measuring quality of life impairment in skeletal muscle channelopathies.

BACKGROUND AND PURPOSE: Fatigue and pain have been previously shown to be important determinants for decreasing quality of life (QoL) in one report in patients with non-dystrophic myotonia. The aims of our study were to assess QoL in skeletal muscle channelopathies (SMC) using INQoL (individualized QoL) and SF-36 questionnaires. METHODS: We administered INQoL and SF-36 to 66 Italian patients with SMC (26: periodic paralysis, 36: myotonia congenita and 4: Andersen-Tawil) and compared the results in 422 patients with myotonic dystrophies (DM1: 382; and DM2: 40). RESULTS: (i) INQoL index in SMC is similar to that in DMs (P = 0.79). (ii) Patients with myotonia congenita have the worst perception of QoL. (iii) Myotonia has the most detrimental effect on patients with myotonia congenita, followed by patients with DM2 and then by patients with DM1 and hyperkalemic periodic paralysis. (iv) Pain is a significant complaint in patients with myotonia congenita, hypokalemic periodic paralysis and DM2 but not in DM1. (v) Fatigue has a similar detrimental effect on all patient groups except for patients with hyperkalemic periodic paralysis in whom muscle weakness and myotonia more than fatigue affect QoL perception. (vi) Muscle symptoms considered in INQoL correlate with physical symptoms assessed by SF-36 (R from -0.34 to -0.76). CONCLUSIONS: QoL perception in patients with SMC is similar to that of patients with DMs, chronic multisystem disabling conditions. Our results provide information to target treatment and health care of these patients. The sensitivity of INQoL to changes in QoL in the SMC needs to be further explored in longitudinal studies.

Not all abolished lung sliding are pneumothorax: the case of a particular lung atelectasis.

INTRODUCTION: Lung ultrasound (LUS) is expanding from the field of emergency medicine, also to the pneumological specialist field, becoming part of the diagnostic procedure of lung consolidation. CASE PRESENTATION: A 78-year-old male was admitted to our emergency department for exertional dyspnea. LUS was performed, thus showing at right hemitorax air interface, A lines pattern, pleural sliding abolished on the whole hemitorax, thus suggesting a pneumothorax, but no evidence of lung point. A scan of lower lung segment showed an absence of the diaphragmatic excursion, suggestive for hemiparalysis of the diaphragm muscle, then confirmed by a subcostal scan. Moreover, at the lower segment of right hemitorax there was mild pleural effusion allowing the visualization of a round-shaped parenchymal consolidation with the absence of air bronchograms. CONCLUSIONS: LUS allowed the visualization of a particular and rare disease such as anthracosis-associated rounded atelectasis, thus leading to a more correct and faster patient management.

Italian validation of INQoL, a quality of life questionnaire for adults with muscle diseases.

BACKGROUND AND PURPOSE: A quality of life (QoL) questionnaire for neuromuscular diseases was recently constructed and validated in the United Kingdom in a sample of adult patients with a variety of muscle disorders. Preliminary results suggested it could be a more relevant and practical measure of QoL in muscle diseases than generic health measures of QoL. The purpose of our work was: (i) To validate INQoL in Italy on a larger sample of adult patients with muscle diseases (ii) to compare INQoL to SF-36. METHODS: We have translated into Italian and applied language adaptations to the original UK INQoL version. We studied 1092 patients with different muscle disorders and performed (i) test-retest reliability (n = 80); (ii) psychometric (n = 345), known-group (n = 1092), external criterion (n = 70), and concurrent validity with SF-36 (n = 183). RESULTS: We have translated and formally validated the Italian version of INQoL confirming and extending results obtained in the United Kingdom. In addition to good results in terms of reliability, known-group and criterion validity, a comparison with the SF-36 scales showed a stronger association between INQoL total index and SF-36 physical (r = -0.72) than mental (r = -0.38) summary health indexes. When considering comparable domains of INQoL and SF-36 with respect to an objective measure of muscle strength assessment (MMRC), regression analysis showed a stronger correlation using INQoL rather than SF-36 scores. CONCLUSIONS: INQoL is recommended to assess QoL in muscle diseases because of its ability to capture physical limitations that are specifically relevant to the muscle condition.

Atrophic endometrium in postmenopausal women referred to diagnostic hysteroscopy: a study to avoid unnecessary examinations.

OBJECTIVE: Any diagnostic workup should be based on appropriateness criteria. Diagnostic hysteroscopy is a procedure widely used in endometrial pathology. Its high outpatient feasibility frequently leads to misuse. However, it can cause discomfort and, albeit rarely, complications. The present study aimed to provide an estimate of unnecessary examinations based on variables associated with atrophic endometrium in postmenopausal women referred to diagnostic hysteroscopy. PATIENTS AND METHODS: One-hundred and sixty-six postmenopausal women undergoing hysteroscopy were retrospectively analyzed. All included women had a final histological reference standard. The sample was divided into women with atrophic endometrium vs. women with endocavitary lesions (benign/premalignant/malignant). Univariate and multivariate analysis was performed to assess those patient characteristics associated with atrophic endometrium. Furthermore, based on the likelihood ratios, a post-test probability analysis was performed to provide an estimate of atrophy according to the presence of specific variables. RESULTS: Sixty-one postmenopausal women (36.7%) undergoing diagnostic hysteroscopy showed atrophic endometrium at final histology. Multivariate analysis showed that the independent variables associated with atrophy were the absence of abnormal uterine bleeding [Odds Ratio (OR)=6.43, Confidence Intervals (CI) 2.087 to 19.822], and endometrial thickness (criterion < 7 mm) (OR=0.417, CI 0.300 to 0.578). In women showing both variables associated with negative endometrial outcome, post-test probability analysis resulted in an atrophic endometrium rate of 89.13%, from a pre-test probability of 36.7%. CONCLUSIONS: About 90% of asymptomatic postmenopausal women with endometrial thickness <7 mm resulted in an atrophic endometrium at hysteroscopy. Every gynecologist should know and consider these data before referring such women to further examinations. In these cases, diagnostic hysteroscopy is not cost-effective leading to a high number of false positives.

Pattern and quality of care of cancer pain management. Results from the Cancer Pain Outcome Research Study Group.

Most patients with advanced or metastatic cancer experience pain and despite several guidelines, undertreatment is well documented. A multicenter, open-label, prospective, non-randomised study was launched in Italy in 2006 to evaluate the epidemiology, patterns and quality of pain care of cancer patients. To assess the adequacy of analgesic care, we used a standardised measure, the pain management index (PMI), that compares the most potent analgesic prescribed for a patient with the reported level of the worst pain of that patient together with a selected list of clinical indicators. A total of 110 centres recruited 1801 valid cases. 61% of cases were received a WHO-level III opioid; 25.3% were classified as potentially undertreated, with wide variation (9.8-55.3%) according to the variables describing patients, centres and pattern of care. After adjustment with a multivariable logistic regression model, type of recruiting centre, receiving adjuvant therapy or not and type of patient recruited (new or already on follow-up) had a significant association with undertreatment. Non-compliance with the predefined set of clinical indicators was generally high, ranging from 41 to 76%. Despite intrinsic limitations of the PMI that may be considered as an indicator of the poor quality of cancer pain care, results suggest that the recourse to WHO third-level drugs still seems delayed in a substantial percentage of patients. This delay is probably related to several factors affecting practice in participating centres and suggests that the quality of cancer pain management in Italy deserves specific attention and interventions aimed at improving patients' outcomes.

Angiogenic potential of human dental pulp stromal (stem) cells.

Dental pulp is a heterogeneous microenviroment where unipotent progenitor and pluripotent mesenchymal stem cells cohabit. In this study we investigated whether human dental pulp stromal (stem) cells (DP-SCs) committed to the angiogenic fate. DP-SCs showed the specific mesenchymal immunophenotypical profile positive for CD29, CD44, CD73, CD105, CD166 and negative for CD14, CD34, CD45, in accordance with that reported for bone marrow-derived SCs. The Oct-4 expression in DP-SCs, evaluated through RT-PCR analysis, increased in relation with the number of the passages in cell culture and decreased after angiogenic induction. In agreement with their multipotency, DP-SCs differentiated toward osteogenic and adipogenic commitments. In angiogenic experiments, differentiation of DP-SCs, through vascular endothelial growth factor (VEGF) induction, was evaluated by in vitro matrigel assay and by cytometric analysis. Accordingly, endothelial-specific markers like Flt-1 and KDR were basally expressed and they increased after exposure to VEGF together with the occurrence of ICAM-1 and von Willebrand factor positive cells. In addition, VEGF-induced DP-SCs maintained endothelial cell-like features when cultured in a 3-D fibrin mesh, displaying focal organization into capillary-like structures. The DP-SC angiogenic potential may prove a remarkable tool for novel approaches to developing tissue-engineered vascular grafts which are useful when vascularization of ischemic tissues is required.

Prevalence of undertreatment in cancer pain. A review of published literature.

BACKGROUND: Pain is a major health care problem for patients with cancer: despite the existence of guidelines for cancer pain management, undertreatment is a widespread problem. Pain Management Indexes (PMIs) evaluate the congruence between the patient's reported level of pain and the intensity/strength of the analgesic therapy. Negative scores indicate inadequate prescriptions. MATERIALS AND METHODS: We conducted a Medline search using terms for 'pain management', 'index' or 'measure' to select studies which measured undertreatment in cancer settings. Univariate and multivariate logistic regression identified associations between independent predictors and high prevalence of undertreatment. RESULTS: Among the 44 studies identified, 26 studies used the PMI as proposed by Cleeland. The range of negative PMI varied from 8% to 82% with a weighted mean value of 43%. In multivariate analyses, factors associated with negative PMI were date of publication before 2001, provenance from Europe or Asia and countries with a gross national income per capita < $40,000 per year and a care setting not specific for cancer. Age was not a significant predictor for undertreatment. CONCLUSION: Nearly one of two patients with cancer pain is undertreated. The percentage is high, but consists of a large variability of undertreatment across studies and settings.

A regional plan of the Emilia-Romagna regional bureau for Aedes albopictus control--year 2008.

Following the outbreak of Chikungunya virus fever occurred in the summer 2007 in Emila Romagna (an administrative region located along the Adriatic (East) coast of Italy) a regional plan for Aedes albopicus control has been implemented. The major items of the plan are here reported and discussed.

Marginal seal evaluation of different resin sealants used in pits and fissures. An in vitro study.

UNLABELLED: ATM: Oral health is important for everyone, but specially for children and people requiring special care owing to impaired manual ability. Primary prevention, with correct oral hygiene, proper diet, use of fluoride and pit and fissure sealants, can reduce caries risk thereby improving patients' quality of life. The first aim of this paper was to assess the marginal microleakage of different pit and fissure sealants after immersion in a cariogenic solution. The second aim was to evaluate the ability of the materials to penetrate into the bottom of the fissure. METHODS: 32 posterior teeth were divided into four groups based on the type of sealant tested: Concise, Clinpro, Fissurit, Fissurit F. Samples were immersed and stored in a lactic acid solution (pH 4.4, 0.1 M) at 37 degrees C for different periods: 1 day; 3 days; 7 days; 10 days. Then each sample was stored in erythrosine solution for 24 hours at 37 degrees C. Each sample was sectioned in a mesio-distal direction and evaluated at the stereomicroscope and subsequently at SEM. RESULTS: SEM analysis showed that Clinpro and Concise obtained a good penetration inside the fissure and a good adaptation to the enamel wall, while Fissurit and Fissurit F showed gaps at the sealant-enamel interface and voids. CONCLUSION: Sealant application is an important means for caries prevention but, for a lasting effect, it must be associated with good oral hygiene and regular dental check-ups.

Rb family proteins as modulators of gene expression and new aspects regarding the interaction with chromatin remodeling enzymes.

The pRb family proteins (pRb1/105, p107, pRb2/p130), collectively referred to as pocket proteins, are believed to function primarily as regulators of the mammalian cell cycle progression, and suppressors of cellular growth and proliferation. In addition, different studies suggest that these pocket proteins are also involved in development and differentiation of various tissues. Several lines of evidence indicate that generally pRb-family proteins function through their effect on the transcription of E2F-regulated genes. In fact, each of Rb family proteins binds to distinct members of the E2F transcription factors, which regulate the expression of genes whose protein products are necessary for cell proliferation and to drive cell-cycle progression. Nevertheless, pocket proteins can affect the G1/S transition through E2F-independent mechanisms. More recently, a broad range of evidences indicate that pRb-family proteins associate with a wide variety of transcription factors and chromatin remodeling enzymes forming transcriptional repressor complexes that control gene expression. This review focuses on the complex regulatory mechanisms by which pRb-family proteins tell genes when to switch on and off.

Cytoplasmic and nuclear interaction between Rb family proteins and PAI-2: a physiological crosstalk in human corneal and conjunctival epithelial cells.

Extracellular plasminogen activator inhibitor type-2 (PAI-2) is a potent inhibitor of urokinase-type plasminogen activator (u-PA) and also acts as a multifunctional protein. However, the biological activity of intracellular PAI-2, as well as its intracellular targets, until now remain an enigma. Here, we show that pRb2/p130 and Rb1/p105, but not p107, interact with PAI-2 in both the cytoplasm and nucleus of normal primary human corneal and conjunctival epithelial cells. We provided the first in vivo evidence that a specific fragment of the PAI-2 promoter is bound simultaneously by pRb2/ p130, PAI-2, E2F5, histone deacetylase 1 (HDAC1), DNA methyltransferase 1 (DNMT1), and histone methyltransferase (SUV39H1), in normal primary human corneal epithelial cells, and by pRb2/p130, PAI-2, E2F5, HDAC1, and DNMT1, in normal primary human conjunctiva epithelial cells. Our results strongly indicate a physiological interaction between pRb family members and PAI-2, suggesting the hypothesis that pRb2/p130 and PAI-2 may cooperate in modulating PAI-2 gene expression by chromatin remodeling, in normal corneal and conjunctival cells.

Virally mediated MafB transduction induces the monocyte commitment of human CD34+ hematopoietic stem/progenitor cells.

Upregulation of specific transcription factors is a generally accepted mechanism to explain the commitment of hematopoietic stem cells along precise maturation lineages. Based on this premise, transduction of primary hematopoietic stem/progenitor cells with viral vectors containing the investigated transcription factors appears as a suitable experimental model to identify such regulators. Although MafB transcription factor is believed to play a role in the regulation of monocytic commitment, no demonstration is, to date, available supporting this function in normal human hematopoiesis. To address this issue, we retrovirally transduced cord blood CD34+ hematopoietic progenitors with a MafB cDNA. Immunophenotypic and morphological analysis of transduced cells demonstrated the induction of a remarkable monomacrophage differentiation. Microarray analysis confirmed these findings and disclosed the upregulation of macrophage-related transcription factors belonging to the AP-1, MAF, PPAR and MiT families. Altogether our data allow to conclude that MafB is a key regulator of human monocytopoiesis.

Identification of a molecular signature predictive of sensitivity to differentiation induction in acute myeloid leukemia.

Acute myeloid leukemia (AML) blasts are immature committed myeloid cells unable to spontaneously undergo terminal maturation, and characterized by heterogeneous sensitivity to natural differentiation inducers. Here, we show a molecular signature predicting the resistance or sensitivity of six myeloid cell lines to differentiation induced in vitro with retinoic acid or vitamin D. The identified signature was further validated by TaqMan assay for the prediction of response to an in vitro differentiation assay performed on 28 freshly isolated AML blast populations. The TaqMan assay successfully predicts the in vitro resistance or responsiveness of AML blasts to differentiation inducers. Furthermore, performing a meta-analysis of publicly available microarray data sets, we also show the accuracy of our prediction on known phenotypes and suggest that our signature could become useful for the identification of patients eligible for new therapeutic strategies.

Correlation between differentiation plasticity and mRNA expression profiling of CD34+-derived CD14- and CD14+ human normal myeloid precursors.

In spite of their apparently restricted differentiation potentiality, hematopoietic precursors are plastic cells able to trans-differentiate from a maturation lineage to another. To better characterize this differentiation plasticity, we purified CD14- and CD14+ myeloid precursors generated by 'in vitro' culture of human CD34+ hematopoietic progenitors. Morphological analysis of the investigated cell populations indicated that, as expected, they consisted of granulocyte and monocyte precursors, respectively. Treatment with differentiation inducers revealed that CD14- cells were bipotent granulo-monocyte precursors, while CD14+ cells appeared univocally committed to a terminal macrophage maturation. Flow cytometry analysis demonstrated that the conversion of granulocyte precursors to the mono-macrophage maturation lineage occurs through a differentiation transition in which the granulocyte-related myeloperoxidase enzyme and the monocyte-specific CD14 antigen are co-expressed. Expression profiling evidenced that the observed trans-differentiation process was accompanied by a remarkable upregulation of the monocyte-related MafB transcription factor.

Nuclear and cytoplasmic interaction of pRb2/p130 and ER-beta in MCF-7 breast cancer cells.

Estrogens exhibit important biological functions and influence several pathological processes of hormone-dependent diseases. The biological actions of estrogens require their interaction with two estrogen receptors (ER-alpha and ER-beta), which are ligand-dependent transcription factors. ER-alpha and ER-beta exhibit distinct tissue expression patterns as well as show different patterns of gene regulation. In addition, it has been suggested that ER-beta works as a counter partner of ER-alpha through inhibition of the transactivating functions of ER-alpha. For instance, ER-beta seems to play a different role in breast tumorigenesis than ER-alpha, as ER-beta decreased expression in breast cancer has been correlated with bad prognosis. Biological activities of ER-alpha and ER-beta could be controlled by a number of interacting proteins such as activators/inhibitors, ligand binding and kinases. We have previously reported that pRb2/p130, retinoblastoma related protein, could be involved in the silencing of ER-alpha gene during breast tumorigenesis. Here, we report that ER-beta and pRb2/p130 proteins co-immunoprecipitate in both nucleus and cytoplasm of MCF-7 breast cancer cells. Our hypothesis is that the interaction of pRb2/130 with ER-beta may have a functional significance in regulating ER-beta activity.

The role of molecular interaction fields on enantioselective and nonselective separation of chiral sulfoxides.

The separation of a series of 23 asymmetric sulfoxides, including the three proton pump inhibitors (PPI) omeprazole, lansoprazole and pantoprazole was investigated by HPLC, under reversed-phase elution with amylose tris(3,5-dimethylphenylcarbamate), amylose tris[(S)-1-phenylethylcarbamate] and amylose tris(3,5-dimethoxyphenylcarbamate) chiral stationary phases, CSP1-3, respectively. The whole set of sulfoxides showed better enantioselectivity and enantioresolution on CSP1. However, the three PPI were enantioseparated only when using CSP1 and CSP3. It was observed an improved enantioselectivity and enantioresolution on CSP3. The mechanisms of retention were evaluated by molecular interaction fields (MIF) generated via GRID force field, which yielded the geometric reasons leading to the scenario outlined. The enantioselective and nonselective interactions are discussed in terms of the reported selectivity. The steric structural outline of the CSP nonselective interaction sites is of major importance to deliver the sulfoxides to the chiral selective sites where the enantioselective interactions take place.

Induction of a functional vitamin D receptor in all-trans-retinoic acid-induced monocytic differentiation of M2-type leukemic blast cells.

Different types of acute myeloid leukemia blast cells were induced to differentiate in vitro with all-trans-retinoic acid (ATRA) and vitamin D3 (VD). M0/M1 leukemic cells are not sensitive to differentiating agents, whereas M3 leukemic cells are induced to undergo granulocytic differentiation after ATRA treatment but are not sensitive to VD. M2 leukemic blast cells behave differently because they undergo monocytic differentiation with both the differentiation inducers. To gain some insight into the maturation of M2-type leukemic cells, we studied the molecular mechanisms underlying monocytic differentiation induced by ATRA and VD in spontaneous M2 blast cells as well as in Kasumi-1 cells (an acute myeloid leukemia M2-type cell line). Our results indicate that ATRA as well as VD efficiently increases the nuclear abundance of VD receptor (VDR) and promotes monocytic differentiation. VDR is functionally active in ATRA-treated Kasumi-1 cells because it efficiently heterodimerizes with retinoid X receptor, binds to a DR3-type vitamin D-responsive element, and activates the transcription of a vitamin D-responsive element-regulated reporter gene. Consistent with these findings, VD-responsive genes are induced by ATRA treatment of Kasumi-1 cells, suggesting that the genetic program underlying monocytic differentiation is activated. The molecular mechanism by which ATRA increases the nuclear abundance of a functional VDR is still unknown, but our data clearly indicate that the M2 leukemic cell context is only permissive of monocytic differentiation.