Analysis of differentially expressed genes in LNCaP prostate cancer progression model.

The LNCaP/C4-2 human prostate cancer progression model was established to mimic phenotypic and genotypic changes during prostate cancer development from androgen dependence to androgen independence, from nonmetastasis to metastasis. In this study, cDNA microarrays were performed using a microarray chip from Affymetrix to characterize and compare gene expression profiles in LNCaP and C4-2, which may provide novel insight into the molecular mechanism mediating prostate cancer progression. Three hundred eighteen genes consistently exhibited differential expression in LNCaP and C4-2 in 2-time microarray data. Based on their function, the differentially expressed genes can be grouped into several subcategories, including growth factors and signal transducers, oncogenes and tumor suppressors, tumor-specific antigens, transcriptional factors, transporters, and factors involved in invasion, metastasis, and metabolism. Some genes are novel and unexplored in prostate cancer progression and are of potential interest for follow-up investigation. Reverse transcription-polymerase chain reaction (RT-PCR) and real-time RT-PCR were performed to corroborate the microarray results, and 76 differentially expressed genes were validated out of 104 candidates. Expression pattern analyses were performed in these 76 differentially expressed genes, and a series of genes was found to be positively or negatively correlated to prostate cancer progression in the LNCaP prostate cancer progression model and to possess predominant prostate cell specificity. ELF5/ESE-2b and long-chain acyl coenzyme A dehydrogenase (ACADL) expressions were found to be positively associated with malignant progression in LNCaP, C4-2, and C4-2B, and predominantly expressed in prostate cancer cells. Functional evaluation revealed that ELF5/ESE-2b and ACADL expressions contributed to the malignant phenotypes of prostate cancer cells. Accordingly, our microarray data may provide clues for finding novel genes involved in prostate cancer progression to androgen independent and metastasis, and shed light on finding new targets for diagnosis and therapy of prostate cancer.

[Identification and expression of two new secretory proteins associated with prostate cancer].

Our research intends to obtain extra-cellular proteinogram of cell lines representing different advancement stages of prostate cancer and to test whether screened differential expression proteins can be secreted and used as serum biomarkers for prostate cancer. By examining differential expression spots in two extra-cellular protein 2D-PAGE gels and mass spectrum, candidate molecules were obtained. The expressions of these candidate molecules in eight cell lines and response to androgen stimulus in LNCaP were analyzed by RT-PCR. By constructing eukaryotic expression vectors and western-blotting with anti tags antibodies, the candidate molecules were tested to understand whether they can be expressed in transfected 293T cell culture fluid. Two overexpressed molecules-triosephosphate isomerase 1 (TPI1) and syndecan bind-ing protein, syntenin (ST1)-in extra-cellular proteinogram of C4-2 were screened out; both of them are secretary proteins. On transcriptional level, both proteins were up-regulated with the malignancy of prostate cancer cell lines and ST1 was dose-dependently inhibited by androgen. Considering cellular level results, both TPI1 and ST1 have their potential as serum biomarkers for indicating the developmental stage of prostate cancer.

The radiation response of androgen-refractory prostate cancer cell line C4-2 derived from androgen-sensitive cell line LNCaP.

Radiation therapy is a relatively effective therapeutic method for localized prostate cancer (PCa) patients. However, radioresistance occurs in nearly 30% of patients treated with potentially curative doses. Therapeutic synergy between radiotherapy and androgen ablation treatment provides a promising strategy for improving the clinical outcome. Accordingly, the androgen deprivation-induced signaling pathway may also mediate radiosensitivity in PCa cells. The C4-2 cell line was derived from the androgen-sensitive LNCaP parent line under androgen-depleted condition and had acquired androgen-refractory characteristics. In our study, the response to radiation was evaluated in both LNCaP and C4-2. Results showed that C4-2 cells were more likely to survive from irradiation and appeared more aggressive in their resistance to radiation treatment compared with LNCaP, as measured by clonogenic assays and cell viability and cell cycle analyses. Gene expression analyses revealed that a set of genes involved in cell cycle arrest and DNA repair were differentially regulated in LNCaP and C4-2 in response to radiation, which was also consistent with the radiation-resistant property observed in C4-2 cells. These results strongly suggested that the radiation-resistant property may develop with progression of PCa to androgen-independent status. Not only can the LNCaP and C4-2 PCa progression model be applied for investigating androgen-refractory progression, but it can also be used to explore the development of radiation resistance in PCa.

Antidiabetic effects of Artemisia sphaerocephala Krasch. gum, a novel food additive in China, on streptozotocin-induced type 2 diabetic rats.

AIM OF THE STUDY: Since ancient times, practicians of traditional Chinese medicine have discovered that Artemisia sphaerocephala Krasch. (Asteraceae) seed powder was useful for the treatment of diabetes. Artemisia sphaerocephala Krasch. gum (ASK gum), which is extracted from seed powder of the plant, is a novel food additive favored by the food industry in China. The objective of this study was to determine the antidiabetic function of ASK gum on type 2 diabetes. MATERIALS AND METHODS: Type 2 diabetic rat model was induced with high fat diet and low dose of streptozotocin (STZ). The effects of ASK gum on hyperglycemia, hyperlipemia, insulin resistance, and liver fat accumulation in type 2 diabetic rats were evaluated. The results were compared to those of normal rats and diabetic rats treated with metformin. RESULTS: The addition of ASK gum to the rats' food supply significantly lowered fasting blood glucose, glycated serum protein, serum cholesterol, and serum triglyceride in type 2 diabetic rats, and significantly elevated liver glucokinase, liver glycogen, and serum high density protein cholesterol in the diabetic rats. ASK gum significantly reduced insulin resistance and liver fat accumulation of type 2 diabetes. CONCLUSION: Artemisia sphaerocephala Krasch. gum can alleviate hyperglycemia, hyperlipemia and insulin resistance of type 2 diabetes.

Ubiquitous mitochondrial creatine kinase is overexpressed in the conditioned medium and the extract of LNCaP lineaged androgen independent cell lines and facilitates prostate cancer progression.

BACKGROUND: Androgen independent prostate cancer (AIPC) is not responsive to androgen ablation therapy. The biomarkers of AIPC are lack. Numerous proteomics studies have focused on finding new markers of AIPC and exploring their possible functions, but little is known about the difference between conditioned medium (CM) from AIPC and androgen dependent prostate cancer (ADPC) cells. METHODS: We performed a proteome analysis of CM from LNCaP, C4-2, and C4-2B cells by a two dimensional electrophoresis based technology. Western blots and immunohistochemical studies were employed to explore the expression pattern of the identified protein in prostate cancer cell lines and clinical specimens, respectively. Then we examined the possible roles and mechanisms of the ubiquitous mitochondrial creatine kinase (uMtCK) in vitro. RESULTS: Besides prostate specific antigen (PSA) and insulin-like growth factor binding protein-2 (IGFBP2), uMtCK was identified in the CM of AIPC cells. uMtCK was up-regulated in AIPC cells and in human prostate cancer tissues at WHO grade III. Stably transfected exogenous uMtCK showed a growth promoting effect rather than mock vector in LNCaP cells, with or without bicalutamide in culture medium. Further assays showed that higher degrees of ROS generation and Akt signaling pathway activation in LNCaP-uMtCK than in LNCaP-neo cells. CONCLUSIONS: We showed that uMtCK could be easily detected in CM of LNCaP lineaged AIPC cells. Exogenous uMtCK in LNCaP cells surprisingly contributed to overproduction of ROS, activation of Akt signaling pathway and more aggressive phenotypes including androgen independence development.

[Epidemiologic study on the relationship between smoking and sleep apnea/hypopnea syndrome].

OBJECTIVE: To investigate how smoking was affecting the prevalence of sleep apnea/ hypopnea syndrome (SAHS) among adults aged over 30 years in Chengde city of Hebei province. METHODS: 1168 subjects, over 30 years of age were derived from a random sample from a community-based population in Shuangqiao district of Chengde city. All subjects responded to a questionnaire at their own houses regarding their habits of snoring and smoking. 1168 subjects (95.2%) answered the questions satisfactorily. RESULTS: (1) Among the smoking groups, the prevalence of snoring was 69.09%, higher than that in the nonsmoking groups 45.07% (P = 0.000). (2) In males, the smoking group had a higher prevalence (69.72%) of snoring than in the nonsmoking group (60.80%, P = 0.033). (3) Females in the smoking group had a higher prevalence of snoring (61.80%) than in the nonsmoking group (39.70%, P = 0.011). (4) The prevalence of snoring in males (60.80%) was significantly higher than that in females (39.70%, P = 0.000). (5) The prevalence (69.72%) of snoring in smoking males was similar to that in smoking females (61.80%, P = 0.336). (6) Data from logistic regression analysis indicated that smoking was one of the factors affecting snoring. (7) According to the degree of snoring, 127 moderate and severe snorers were measured by portable PSG for a whole night and the prevalence of SAHS was estimated. According to the AHI > or = 5 and the ESS > or = 9 cutoff-points, the prevalence rates of SAHS in smoking groups were both significantly higher than that in nonsmoking groups (P < 0.001). CONCLUSION: Smoking and snoring among adults aged over 30 years had correlation in our city.

[Epidemiologic study on sleep apnea-hypopnea syndrome by home investigation in Chengde city].

OBJECTIVE: To investigate the prevalence of sleep apnea-hypopnea syndrome (SAHS) among adults aged over 30 yr in Chengde city of Hebei province. METHODS: 1 168 subjects (over 30 yr) were derived from a random sample of the population among the Shuangqiao district in Chengde city. All subjects were asked at home to answer questions about their snoring, daytime sleepiness, and habits of smoking and drinking. According to the degree of snoring, 127 moderate and severe snorers were measured by portable PSG for a whole night and the prevalence of SAHS was estimated according to AHI and ESS scores. RESULTS: 1 168 subjects (95.42%) answered the questions. The prevalence of snoring was 53.76%. The prevalence of moderate and severe snoring (>or= second degree) was 28.25%. The prevalence of snoring increased with age before the age of 70. The prevalence of snoring in males was significantly higher than that in females. Smoking and drinking groups were associated with a higher prevalence of snoring. The prevalence of snoring was higher in drivers (42.00%) than that in other populations. The estimated prevalence of SAHS according to both the AHI > 5 and the ESS >or= 9 was 4.63%. CONCLUSIONS: The estimated prevalence of SAHS among adults aged over 30 yr in Chengde city was 4.63%. It means that SAHS needs better understanding and more study.