Hemorrhagic risk factors after rt PA thrombolysis in acute cerebral infarction.

OBJECTIVE: This study aims to investigate the risk factors of hemorrhagic transformation (HT) after thrombolysis with recombinant tissue plasminogen activator (rt-PA) in patients with acute cerebral infarction (ACI) and establish a logistic regression equation and the risk prediction model. PATIENTS AND METHODS: One hundred and ninety patients with ACI were divided into the HT group (n=20) and non-HT group (n=170) according to whether HT occurred within 24 hours after rt-PA thrombolysis. The clinical data were collected for analyzing the influencing factors, and a logistic regression analysis model was then established. Besides, patients in the HT group were further grouped into symptomatic hemorrhage (n=7) and non-symptomatic hemorrhage (n=13) according to the type of hemorrhage. The clinical diagnostic value of risk factors in symptomatic hemorrhage after thrombolysis in ACI was analyzed using the ROC curve. RESULTS: We found that history of atrial fibrillation, time from onset to thrombolysis, pre-thrombolytic glucose, pre-thrombolytic National Institute of Health Stroke Scale (NIHSS) score, 24-hour post-thrombolytic NIHSS score, and proportion of patients with large cerebral infarction were all the influencing factors of HT risk after rt-PA thrombolysis in patients with ACI (p<0.05). Logistic regression analysis model was established with an accuracy of 88.42% (168/190), a sensitivity of 75.00% (15/20), and a specificity of 90.00% (153/170). The time from onset to thrombolysis, pre-thrombolytic glucose, and 24-hour post-thrombolytic NIHSS score had higher clinical value in predicting the risk of HT after rt-PA thrombolysis, with the AUCs of 0.874, 0.815 and 0.881, respectively. Blood glucose and pre-thrombolytic NIHSS score were independent risk factors related to symptomatic hemorrhage after thrombolysis in ACI (p<0.05). The AUCs for predicting symptomatic hemorrhage alone and in combination were 0.813, 0.835, and 0.907, respectively, with sensitivities of 85.70%, 87.50% and 90.00%, and specificities of 62.50%, 60.00%, and 75.42% respectively. CONCLUSIONS: The establishment of a prediction model based on the risk factors of HT after rt-PA thrombolysis had a good predictive value in patients with ACI. This model was helpful in guiding clinical judgment and improving the safety of intravenous thrombolysis. Early identification of symptomatic bleeding risk factors provided a reference for clinical treatment and prognostic measures of patients with ACI.

Abnormal hyperplasia of chondrocytes in a rat model of glucocorticoid-induced osteonecrosis of the femoral head.

OBJECTIVE: The aim of our study was to determine whether abnormal hyperplasia of chondrocytes occurs in glucocorticoid-induced osteonecrosis of the femoral head (GC-ONFH) using a well-established rat model. MATERIALS AND METHODS: Rats were injected with lipopolysaccharide and methylprednisolone to induce GC-ONFH, while control animals were injected with saline (12 animals per group). Establishment of the disease model was confirmed using micro-computed tomography and hematoxylin-eosin (HE) staining of femoral head tissue sections. Chondrocyte hyperplasia was detected using HE staining and semi-quantitated using toluidine blue and saffron O staining. Expression of the autophagy marker LC3B was assessed in cartilage tissues of femoral head using immunohistochemistry. RESULTS: GC-ONFH animals showed significantly greater area of abnormal chondrocyte hyperplasia in femoral head tissue sections than control animals. They also showed significantly higher expression of LC3B in articular cartilage of the femoral head. CONCLUSIONS: GC-ONFH may be associated with abnormal chondrocyte hyperplasia in articular surface cartilage, which may be related to glucocorticoid-induced overactivation of autophagy.

Quantitative systems pharmacology modeling sheds light into the dose response relationship of a trispecific T cell engager in multiple myeloma.

In relapsed and refractory multiple myeloma (RRMM), there are few treatment options once patients progress from the established standard of care. Several bispecific T-cell engagers (TCE) are in clinical development for multiple myeloma (MM), designed to promote T-cell activation and tumor killing by binding a T-cell receptor and a myeloma target. In this study we employ both computational and experimental tools to investigate how a novel trispecific TCE improves activation, proliferation, and cytolytic activity of T-cells against MM cells. In addition to binding CD3 on T-cells and CD38 on tumor cells, the trispecific binds CD28, which serves as both co-stimulation for T-cell activation and an additional tumor target. We have established a robust rule-based quantitative systems pharmacology (QSP) model trained against T-cell activation, cytotoxicity, and cytokine data, and used it to gain insight into the complex dose response of this drug. We predict that CD3-CD28-CD38 killing capacity increases rapidly in low dose levels, and with higher doses, killing plateaus rather than following the bell-shaped curve typical of bispecific TCEs. We further predict that dose-response curves are driven by the ability of tumor cells to form synapses with activated T-cells. When competition between cells limits tumor engagement with active T-cells, response to therapy may be diminished. We finally suggest a metric related to drug efficacy in our analysis-"effective" receptor occupancy, or the proportion of receptors engaged in synapses. Overall, this study predicts that the CD28 arm on the trispecific antibody improves efficacy, and identifies metrics to inform potency of novel TCEs.

Outcomes of hepatic epithelioid hemangioendothelioma with different managements: a retrospective investigation.

OBJECTIVE: Hepatic epithelioid hemangioendothelioma (HEH) is an extremely rare tumor, and no standard treatment has been established yet. This study aimed to retrospectively investigate the outcomes of different managements for HEH patients. PATIENTS AND METHODS: From March 2014 to November 2019, a retrospective investigation was performed among 50 HEH patients to summarize the outcomes of different managements. Their medical records were collected, and the outcome of each management was evaluated based on radiological images. RESULTS: Of the 50 HEH patients examined, 80% were asymptomatic, and 94% had multiple intrahepatic lesions. Extrahepatic metastases were detected in 54% of patients, and 82% of patients were radiologically misdiagnosed. 16 (88.9%) of 18 patients with initial observation had progressive disease (PD). Of 12 patients with curatively intended surgery or radiofrequency ablation (RF), 10 (83.3%) of them had a recurrence. Six treated patients with interferon-α had results of 4 partial responses (PR), 1 complete response (CR), and 1 stable disease (SD). Of 6 patients with thalidomide, 4 patients had PD, and 2 patients had SD. Four patients treated with chemotherapy had 3 PD and 1 SD. Five patients treated with targeted therapy had 2 PR, 2 PD, and 1 SD. CONCLUSIONS: During our observation, we found that HEH patients had a high chance of PD. The risk of recurrence after surgery or RF was high. The encouraging result of interferon-α therapy makes it a promising treatment for HEH.

Examining the association between serum free fatty acids and blood levels of testosterone.

BACKGROUND: Multiple studies have uncovered the effects that ingested fat has on human blood levels of testosterone. Yet, few reports have discussed the effect of circulating serum free fatty acids (FFAs). The present study aimed to explore the relationship between serum free fatty acids and blood levels of testosterone. METHODS: In total, 5719 adults were pooled from the database of the National Health and Nutrition Examination Survey (NHANES) from 2011 to 2012. Based on multivariable-linear regression models, we employed a total of 30 FFAs to interpret the relationship of FFAs with blood levels of testosterone. Two models with covariate adjustments were designated for further evaluation and analysis. RESULTS: Capric acid [ß = -0.014, 95% confidence interval (CI) = -0.023, -0.004, P = 0.005], myristic acid (ß = -0.001, 95% CI = -0.001, 0.000, P ≤ 0.001), pentadecanoic acid (ß = -0.013, 95% CI = -0.018, -0.008, P ≤ 0.001), margaric acid (ß = -0.011, 95% CI = -0.017, -0.005, P ≤ 0.001) and alpha-linolenic acid (ß = -0.001, 95% CI = -0.002, 0.000, P = 0.004) in the fully adjusted model were significantly negatively correlated with the testosterone level inh obese men. In the fully adjusted model for the female analysis, myristic acid, pentadecanoic acid, palmitic acid, margaric acid, stearic acid, myristoleic acid, oleic acid, nervonic acid and alpha-linolenic acid were found significantly associated with the testosterone level. CONCLUSIONS: Our findings indicate a significant negative correlation between serum FFAs and blood levels of testosterone. Furthermore, we reveal the essentiality of serum FFAs and their potential effects on the reduction of testosterone levels.

Morphine induces the apoptosis of mouse hippocampal neurons HT-22 through upregulating miR-181-5p.

OBJECTIVE: To elucidate the role of morphine in inducing apoptosis of mouse hippocampal neurons HT-22 by upregulating microRNA-181-5p (miR-181-5p). MATERIALS AND METHODS: After treatment of different doses of morphine, changes in proliferative ability, apoptosis, and expression levels of miR-181-5p and MAPK1 in HT-22 cells were assessed through a series of functional experiments. Regulatory effects of miR-181-5p on morphine-induced phenotype changes of HT-22 cells were examined. The interaction between miR-181-5p and MAPK1, and their involvement in morphine-induced neuron apoptosis were explored by Luciferase assay and rescue experiments, respectively. RESULTS: Morphine treatment markedly attenuated viability and proliferative ability in HT-22 cells, while apoptotic rate increased. MiR-181-5p was upregulated and MAPK1 was downregulated in HT-22 cells by morphine induction. Knockdown of miR-181-5p enhanced viability and proliferative ability, as well as reduced apoptosis in morphine-induced HT-22 cells. MiR-181-5p could specifically bind MAPK1 and negatively regulate its expression level. Knockdown of MAPK1 was able to reverse the regulatory effects of miR-181-5p on morphine-induced phenotype changes of HT-22 cells. CONCLUSIONS: Morphine induces apoptosis of hippocampal neurons HT-22 by upregulating miR-181-5p to suppress the level of MAPK1.

The efficacy of simendan in the treatment of acute heart failure and its impact on NT-proBNP.

OBJECTIVE: Simendan is a calcium sensitizer that enhances myocardial contractility but does not affect ventricular diastole. Simendan also has a vasodilatation effect, which causes coronary artery resistance and venous volume blood vessel relax, thereby improving coronary blood supply. This study adopted simendan on the basis of conventional anti-heart failure treatment to explore a new approach for the treatment of heart failure. PATIENTS AND METHODS: Eighty patients with heart failure were randomly and equally divided into an observation group and control group according to the digital table method. The control group was given a conventional anti-heart failure treatment. The observation group was treated with simendan on the basis of the control group. The left ventricular ejection fraction (LEVF), stroke volume (SV), NT-proBNP, K+, and Ca2+ were measured before and after the treatment. The clinical efficacy and adverse reactions after treatment were compared. The 6-minute walking distance (6MWT) was recorded on the 60th day after treatment. RESULTS: There were no significant differences in LVEF and SV between the two groups before the treatment. They were significantly increased after treatment and were significantly higher in the observation group than that in the control group (p < 0.05). The total effective rate in the observation group (92.50%) was significantly higher than that in the control group (67.50%). There was no statistical difference in the occurrence of adverse reactions between the two groups (p > 0.05). The 6MWT in the observation group was 452.63±86.51 meters, which was significantly higher than that in the control group (366.85±70.46 meters) (p < 0.05). There was no significant difference in plasma NT-proBNP levels between the two groups (p > 0.05). The plasma NT-proBNP level was significantly lower in the observation group than that in the control group after treatment (p < 0.05). Serum K+ and Ca2+ were not significantly changed after treatment in the control group (p > 0.05). Serum K+, but not Ca2+, was significantly elevated in the observation group. CONCLUSIONS: Simendan can significantly reduce plasma NT-proBNP level; thus, it is relatively safe and effective for the treatment of acute heart failure (AHF).

HMTH1 induces the metastasis and recurrence of the parotid adenoma by repairing DNA damage.

OBJECTIVE: To investigate the effect of hMTH1 (human mutT homologue 1) on inducing the metastasis and recurrence of parotid adenoma, which may provide a new therapeutic direction for the prevention and treatment of parotid adenoma. PATIENTS AND METHODS: 30 cases of paraffin-embedded specimens of parotid adenoid cystic carcinoma (ACC) tissues and fresh parotid glands surgically resected in our hospital were collected as experimental group. 30 cases of surgically resected pleomorphic adenoma (PA) in the same period were selected as another experimental group. Meanwhile, 30 cases of normal parotid gland tissues (N) were collected as control group. The mRNA and protein expressions of hMTH1 in parotid gland tissues of patients with parotid adenoma before and after surgery were detected by Quantitative Real-Time Polymerase Chain Reaction (qRT-PCR) and Western blotting, respectively. HMTH1 expression levels in parotid gland tissues were also detected by immunohistochemistry. Proliferation, apoptosis and DNA damage of ACC-M cells treated with S-Crizotinib were detected by cell counting kit-8 (CCK-8) assay, flow cytometry and single cell gel electrophoresis, respectively. RESULTS: Both mRNA and protein expressions of hMTH1 in experimental group were significantly higher than those of control group. Moreover, a higher expression of hMTH1 was observed in ACC than that of PA, indicating that hMTH1 expression was positively correlated with the malignant degree of parotid adenoma. Furthermore, postoperative hMTH1 expression levels in patients with parotid adenoma were significantly lower than those before treatment, which were remarkably increased in recurrent patients. In vitro experiments demonstrated that S-Crizotinib, the hMTH1 inhibitor, could inhibit proliferation and induce apoptosis and DNA damage of ACC-M cells. CONCLUSIONS: HMTH1 was upregulated in patients with parotid adenoma and recurrent patients after surgery. Meanwhile, S-Crizotinib induced DNA damage in ACC-M cells, indicating that hMTH1 induced the metastasis and recurrence of parotid adenoma by repairing DNA damage, providing a new strategy for the prevention and treatment of parotid adenoma.

Gemcitabine and cisplatin for treatment of lung cancer in vitro and vivo.

OBJECTIVE: To evaluate the antitumor activity of gemcitabine (GEM), cisplatin (DDP) as well as the combination of these two agents in lung cancer cells and mice. MATERIALS AND METHODS: The cell viability was evaluated by the CCK-8 assay. Cell apoptosis was measured by flow cytometry assay and Hoechst staining. The protein expression of VEGF, VEGFR2, Ang II, AT1R, and ACE2 was examined by Western blotting. The effect of GEM and DDP on tumor growth and survival time was also measured in lung cancer mice in vivo. RESULTS: The results revealed that alone or combined administration of GEM and DDP could inhibit the growth, induce apoptosis and apoptotic body formation of A549 cells compared with control cells, with the most significance detected in a combination of GEM and DDP administration. It is indicated that combined administration of GEM and DDP could delay the progress of tumor formation in nude mice. The cell apoptosis- and angiogenesis-related proteins expressions were decreased both in A549 cells and lung cancer mice. CONCLUSIONS: GEM plus DDP can be an option for patients with lung cancer treatment. However, further prospective evaluation and randomized trials are to provide more accurate information through clinical trials.

Supraglottic jet oxygenation and ventilation during colonoscopy under monitored anesthesia care: a controlled randomized clinical trial.

OBJECTIVE: Supraglottic jet oxygenation and ventilation may provide active pulse oxygenation and ventilation in patients with respiratory suppression. This randomized controlled clinical study was designed to determine the efficacy and safety of supraglottic jet oxygenation/ventilation during monitored anesthesia care (MAC) by intravenous (IV) infusion of propofol in patients undergoing colonoscopy. PATIENTS AND METHODS: Forty-nine adult patients receiving colonoscopy were randomly divided into two groups: the control group with passive oxygen supply from regular nasal cannula (N = 24) and the supraglottic jet oxygenation/ventilation (SJV) group with active pulse oxygen supply and ventilation using a manual jet ventilator (N = 25). MAC was induced and maintained by intravenous injection of propofol. HR, ECG, BP, SaO2 were continuously monitored during and 1 hour after the procedure. RESULTS: Demographic characteristics were similar in height, weight, age and BMI (Body Mass Index) between the two groups. Compared to the control group, the SJV group had similar averaged lowest SaO2, but highest SaO2 in SJV group were significantly lower during operation (p = 0.01). The proportion of maximum chest rise movement were increased significantly in SJV group (p = 0.03) compared with control group. Demographic characteristics were similar in the times needed to use facial mask ventilation, percentage of time to maintain SaO2 above 96%, average PetCO2 during the procedure, or complications between the two groups. CONCLUSIONS: SJV can provide adequate oxygenation/ventilation during monitored anesthesia care and convenient monitoring for patients' breath, without complications.

A quantitative analysis of (1)H-MR spectroscopy at 3.0 T of three brain regions from childhood to middle age.

OBJECTIVE: To study age-related metabolic changes in different brain regions. METHODS: Point-resolved spectroscopy (repetition time/echo time = 2000 ms/30 ms) was performed in the left and right hippocampus, the left thalamus and the left centrum semiovale of 80 healthy subjects (37 females and 43 males aged 7-64 years). Analysis of covariance and linear regression were used for statistical analysis. Both metabolite concentration ratios with respect to total creatine (tCr) and absolute metabolite concentrations were included for analysis. RESULTS: Ins (myo-inositol)/tCr (p < 0.001) and absolute Ins concentration (p = 0.031) were significantly increased with age after adolescence. NAA (N-acetylaspartic acid)/tCr (p < 0.001) and absolute NAA concentration (p = 0.010) significantly declined with age after adolescence. CONCLUSION: Age-related increase of Ins and decline of NAA are found in all three regions, especially at the hippocampus, indicating possible gliosis in the ageing brain. ADVANCES IN KNOWLEDGE: We could use NAA/tCr and Ins/tCr as an indicator to estimate the neurons-to-glial cells ratio at the thalamus. This may be an index to distinguish normal tissues from gliosis.

Isolation and characterization of microsatellite markers for Amomum tsaoko (Zingiberaceae), an economically important plant in China.

Twenty-four microsatellite markers were isolated from the genomic DNA of Amomum tsaoko Crevost et Lemaire, an important economic plant in China, using the method fast isolation by AFLP of sequences containing repeats (FIASCO). Polymorphism within each locus was assessed in 60 individuals from three populations in Yunnan Province, China, and nine of them were polymorphic. The number of alleles per polymorphic locus was 2, and the expected and observed heterozygosities ranged from 0.224 to 0.513, and from 0.050 to 0.600, respectively. Among nine microsatellite markers with polymorphism, five showed significant deviation from Hardy-Weinberg equilibrium (P < 0.01), probably due to anthropic selection and short-cloning history in cultivation. No significant linkage disequilibrium was detected between loci in our analysis. These polymorphic microsatellite markers will facilitate further studies of gene flow, population structure, identification of cultivated variety, and evaluation of germplasm resources.

An animal experimental study of porous magnesium scaffold degradation and osteogenesis

Our objective was to observe the biodegradable and osteogenic properties of magnesium scaffolding under in vivo conditions. Twelve 6-month-old male New Zealand white rabbits were randomly divided into two groups. The chosen operation site was the femoral condyle on the right side. The experimental group was implanted with porous magnesium scaffolds, while the control group was implanted with hydroxyapatite scaffolds. X-ray and blood tests, which included serum magnesium, alanine aminotransferase (ALT), creatinine (CREA), and blood urea nitrogen (BUN) were performed serially at 1, 2, and 3 weeks, and 1, 2, and 3 months. All rabbits were killed 3 months postoperatively, and the heart, kidney, spleen, and liver were analyzed with hematoxylin and eosin (HE) staining. The bone samples were subjected to microcomputed tomography scanning (micro-CT) and hard tissue biopsy. SPSS 13.0 (USA) was used for data analysis, and values of P<0.05 were considered to be significant. Bubbles appeared in the X-ray of the experimental group after 2 weeks, whereas there was no gas in the control group. There were no statistical differences for the serum magnesium concentrations, ALT, BUN, and CREA between the two groups (P>0.05). All HE-stained slices were normal, which suggested good biocompatibility of the scaffold. Micro-CT showed that magnesium scaffolds degraded mainly from the outside to inside, and new bone was ingrown following the degradation of magnesium scaffolds. The hydroxyapatite scaffold was not degraded and had fewer osteoblasts scattered on its surface. There was a significant difference in the new bone formation and scaffold bioabsorption between the two groups (9.29±1.27 vs 1.40±0.49 and 7.80±0.50 vs 0.00±0.00 mm3, respectively; P<0.05). The magnesium scaffold performed well in degradation and osteogenesis, and is a promising material for orthopedics.

Impact of cold ischemia on cytokines after partial liver transplantation in rats.

To study the impact of cold ischemia on tumor necrosis factor-alpha (TNF-α) and interleukin-10 (IL-10) expression after liver transplantation, a stable model of partial liver transplantation in rats was established. The experimental animals were divided into the following groups: a partial hepatectomy control group, a group that received partial liver transplantation after 30 min of cold ischemia (experimental group A), and a group that received a partial liver transplantation after 10 h of cold ischemia (experimental group B). The survival rate was observed in each group. The liver tissue was sampled 1, 2, and 4 days after surgery, and immunohistochemical detection of proliferating cell nuclear antigen TNF-α and IL-10 was performed. The correlation between liver regeneration and TNF-α and IL-10 expression was analyzed, and the impact of the 2 cytokines on rat liver regeneration after liver transplantation was evaluated. The survival rates of rats in the partial hepatectomy control group, in the group that received a partial liver transplantation after 30 min of cold ischemia, and the group that received a partial liver transplantation after 10 h of cold ischemia were 100, 70, and 33.3%, respectively. The expression of proliferating cell nuclear antigen and TNF-α was decreased (P < 0.05), and IL-10 expression was increased (P < 0.05) in animals that received a partial liver transplant after 10 h of cold ischemia compared with that in the animals that received a partial liver transplant after 30 min of cold ischemia. We conclude that with the extension of cold ischemic time, liver regeneration and survival rate after liver transplantation decreased. TNF-α and IL-10 play important regulatory roles in the regeneration process of transplanted livers.

Chicken domestication: an updated perspective based on mitochondrial genomes.

Domestic chickens (Gallus gallus domesticus) fulfill various roles ranging from food and entertainment to religion and ornamentation. To survey its genetic diversity and trace the history of domestication, we investigated a total of 4938 mitochondrial DNA (mtDNA) fragments including 2843 previously published and 2095 de novo units from 2044 domestic chickens and 51 red junglefowl (Gallus gallus). To obtain the highest possible level of molecular resolution, 50 representative samples were further selected for total mtDNA genome sequencing. A fine-gained mtDNA phylogeny was investigated by defining haplogroups A-I and W-Z. Common haplogroups A-G were shared by domestic chickens and red junglefowl. Rare haplogroups H-I and W-Z were specific to domestic chickens and red junglefowl, respectively. We re-evaluated the global mtDNA profiles of chickens. The geographic distribution for each of major haplogroups was examined. Our results revealed new complexities of history in chicken domestication because in the phylogeny lineages from the red junglefowl were mingled with those of the domestic chickens. Several local domestication events in South Asia, Southwest China and Southeast Asia were identified. The assessment of chicken mtDNA data also facilitated our understanding about the Austronesian settlement in the Pacific.

Cor triatriatum with tetralogy of Fallot and anomalous drainage of left superior vena cava: a case report and literature review.

Cor triatriatum is a rare malformation, especially in association with tetralogy of Fallot, and has only been reported a few times in the literature. Due to the complexity of this abnormality, careful intraoperative exploration and a good differential diagnosis are crucial to select the appropriate surgical procedure. Here, we report a case with this rare combination of anomalies, an abnormal membranous septum above the mitral valve, and anomalous drainage of the left superior vena cava. The patient was successfully treated and achieved excellent hemodynamic parameters.

Stabilizing microtubules decreases myocardial ischaemia-reperfusion injury.

Microtubules are important components of the cytoskeleton that forms the backbone of myocardial architecture, sustaining its form and size. This study investigated whether stabilizing microtubules with paclitaxel (0.1 or 1 µM) could decrease myocardial ischaemia- reperfusion injury, and reduce myocardial infarct size and the incidence of ischaemic ventricular arrhythmia. Isolated rat hearts were used, with arrhythmia induced by regional ischaemia and myocardial infarcts induced by ischaemia-reperfusion. In these ex vivo rat models, paclitaxel decreased myocardial ischaemia-reperfusion injury, significantly reducing the incidence and severity of ischaemic ventricular arrhythmia and significantly decreasing infarct size.

Androgen receptor coregulators NOCR1, TIF2, and ARA70 may account for the hydroxyflutamide insensitivity of prostate cancer cells.

INTRODUCTION: Prostate cancer cells can switch from an androgen-dependent state to an androgen-independent state after a continuous androgen ablation therapy. However, the molecular mechanisms underlying this switch are still unclear. Therefore, we explored the change in androgen receptor (AR)-related gene expression during this transition in a novel cell model. MATERIAL AND METHODS: Prostate cancer cells were continuously treated with competitive androgen receptor inhibitor hydroxyflutamide for 1.5 years, which yielded an flutamide-insensitive LNCaP subline, LNCaP-flu, as confirmed by MTT assays, flow cytometry, and electron microscopy. We analyzed the differences in gene expression in LNCaP-flu cells and LNCaP cells using gene chips and follow-up RT-PCR. RESULTS: Over 2,428 genes were differentially expressed between these cell lines: 1,194 were down-regulated and 1,234 were up-regulated. Three genes in particular were considered related to the androgen-dependent transition: NCOR1, TIF2 (NCOA2), and ARA70 (NCOA4). There were no apparent changes in expression of the androgen receptor or prostate-specific antigen. CONCLUSION: ARs and associated coregulators play a central role in the flutamide-insensitive transition of prostate cancer cells. Although AR expression does not change during this transition, the change in AR coregulators may be a critical factor in the development of antiandrogen insensitivity.