Epigenetic silencing schlafen-11 sensitizes esophageal cancer to ATM inhibitor.

BACKGROUND: Targeting DNA damage response (DDR) pathway is a cutting-edge strategy. It has been reported that Schlafen-11 (SLFN11) contributes to increase chemosensitivity by participating in DDR. However, the detailed mechanism is unclear. AIM: To investigate the role of SLFN11 in DDR and the application of synthetic lethal in esophageal cancer with SLFN11 defects. METHODS: To reach the purpose, eight esophageal squamous carcinoma cell lines, 142 esophageal dysplasia (ED) and 1007 primary esophageal squamous cell carcinoma (ESCC) samples and various techniques were utilized, including methylation-specific polymerase chain reaction, CRISPR/Cas9 technique, Western blot, colony formation assay, and xenograft mouse model. RESULTS: Methylation of SLFN11 was exhibited in 9.15% of (13/142) ED and 25.62% of primary (258/1007) ESCC cases, and its expression was regulated by promoter region methylation. SLFN11 methylation was significantly associated with tumor differentiation and tumor size (both P < 0.05). However, no significant associations were observed between promoter region methylation and age, gender, smoking, alcohol consumption, TNM stage, or lymph node metastasis. Utilizing DNA damaged model induced by low dose cisplatin, SLFN11 was found to activate non-homologous end-joining and ATR/CHK1 signaling pathways, while inhibiting the ATM/CHK2 signaling pathway. Epigenetic silencing of SLFN11 was found to sensitize the ESCC cells to ATM inhibitor (AZD0156), both in vitro and in vivo. CONCLUSION: SLFN11 is frequently methylated in human ESCC. Methylation of SLFN11 is sensitive marker of ATM inhibitor in ESCC.

Iodine status and its association with prevalence of thyroid diseases in adults from Jiangxi Province, China.

BACKGROUND: Iodine is an essential element for the biosynthesis of thyroid-stimulating hormone (TSH). Both excessive and deficient iodine are major risk factors for thyroid diseases, including thyroid dysfunction, thyroid nodules, and thyroid autoimmunity (TAI). This study aimed to elucidate the relationship between iodine status and the prevalence of thyroid diseases through a national cross-sectional epidemiological survey in Jiangxi province (China). METHODS: This population-based, cross-sectional study enrolled 2636 Chinese local inhabitants who aged over 18 years old from April to August in 2015. Physical examination was performed and biochemical indices, urinary iodine concentration (UIC), and TSH level were measured. The Chi-square test, nonparametric test, and 4 multivariate logistic regression models adjusted for risk factors were applied to analysis. Spearman correlation coefficients were calculated to investigate the relationship between iodine intake level and the prevalence of thyroid diseases. RESULTS: The median UIC was 176.4 µg/L, and a significant difference was found in median UIC between men (182.45 µg/L) and women (169.25 µg/L) (P = 0.03). Among these study subjects, 14.4%, 44.5%, 26.1%, and 15.0% had deficient, adequate, more than adequate, and excessive iodine concentrations, respectively. The prevalence rates of hyperthyroidism, subclinical hyperthyroidism, hypothyroidism, subclinical hypothyroidism, thyroid nodules, and TAI were 0.91%, 0.57%, 0.34% and 7.89%, 9.45%, and 12.7%, respectively. Significant differences were found in iodine status, waist circumstance, systolic blood pressure (SBP), diastolic blood pressure (DBP), total cholesterol (TC), TSH, thyroid nodules, and TAI between men and women (P < 0.05). Compared with those with adequate UIC, subjects with excessive UIC had higher prevalence rates of thyroid dysfunction (odds ratio (OR) = 1.74, 95% confidence interval (CI): 1.40-2.54) and thyroid nodules (OR = 3.33, 95%CI 1.32-8.42). In addition, subjects with deficient and excessive UIC were at the higher risk of TAI compared with those with adequate UIC (OR = 1.68, 95%CI: 1.19-2.60; OR = 1.52, 95%CI: 1.04-2.96, respectively). UIC was positively correlated with the prevalence rates of thyroid nodules (r = -0.44, P < 0.01) and TAI (r = -0.055, P < 0.01). On the contrary, UIC was negatively correlated with the risk of thyroid dysfunction (r = -0.24, P > 0.05). CONCLUSION: Adult inhabitants from Jiangxi province in the TIDE study were in the adequate iodine status. Excessive iodine status was noted as a risk factor for thyroid dysfunction and thyroid nodules. In addition, both iodine deficiency and excessive iodine were risk factors for TAI.

The Effects of Acarbose on Non-Diabetic Overweight and Obese Patients: A Meta-Analysis.

INTRODUCTION: This systematic review aims to verify the efficacy of acarbose monotherapy in treating obese or overweight patients without diabetes. METHODS: In the study, we conducted a systematic search of the Pub-Med, EMBASE, Cochrane and Science Citation Index Expanded databases in search of clinical trials on acarbose treatment, overweight and obesity. The crucial inclusion criteria were as follows: (1) patients were diagnosed as overweight or obese (BMI ≥ 25 kg/m2); (2) randomized controlled trials (RCTs); (3) patients had undergone acarbose monotherapy or placebo control; (4) acarbose treatment had been carried out for at least 3 months. Exclusion criteria were as follows: (1) patients diagnosed with diabetes mellitus (DM); (2) patients had received a weight loss medication or surgery in the past 3 months; (3) papers not published in English; (4) repeated research results of the same experiment or repeated published documents. RESULTS: A total of 7 studies involving 132 in the acarbose group and 137 in placebo group, 269 subjects in total, were included in this meta-analysis. From the selected seven papers, we extracted the following clinical parameters: systolic blood pressure (SBP), diastolic blood pressure (DBP), body weight (BW), body mass index (BMI), triglyceride (TG), total cholesterol (TC), low density lipoprotein (LDL), high density cholesterol (HDL) and fasting plasma glucose (FPG). An important finding of our research is that TG was the only significantly reduced parameter in the acarbose group. Weight mean difference (WMD) was - 0.21 (95% CI - 0.33, - 0.09) mmol/l between acarbose (P = 0.0006) and placebo patients. Reduction of BMI was also greater for acarbose than placebo subjects, although the discrepancy was not statistically significant (P = 0.56). Moreover, no hypoglycemia occurred in either the acarbose group or placebo group. A few subjects experienced gastrointestinal reactions, but these were mild and improved over time. Acarbose has no obvious influence on other metabolic indexes. CONCLUSION: Acarbose monotherapy is beneficial in reducing TG levels in obese or overweight patients and will not result in hypoglycemia during medication. The side effects of acarbose are mild.

Association between Chinese Medicine Therapy and Survival Outcomes in Postoperative Patients with NSCLC: A Multicenter, Prospective, Cohort Study.

OBJECTIVE: To evaluate the association between Chinese medicine (CM) therapy and disease-free survival (DFS) outcomes in postoperative patients with non-small cell lung cancer (NSCLC). METHODS: This multiple-center prospective cohort study was conducted in 13 medical centers in China. Patients with stage I, II, or IIIA NSCLC who had undergone radical resection and received conventional postoperative treatment according to the National Comprehensive Cancer Network (NCCN) guidelines were recruited. The recruited patients were divided into a CM treatment group and a control group according to their wishes. Patients in the CM treatment group received continuous CM therapy for more than 6 months or until disease progression. Patients in the control group received CM therapy for less than 1 month. Follow-up was conducted over 3 years. The primary outcome was DFS, with recurrence/metastasis rates as a secondary outcome. RESULTS: Between May 2013 and August 2016, 503 patients were enrolled into the cohort; 266 were classified in the CM treatment group and 237 in the control group. Adjusting for covariates, high exposure to CM was associated with better DFS [hazard ratio (HR) = 0.417, 95% confidential interval (CI): 0.307-0.567)]. A longer duration of CM therapy (6-12 months, 12-18 months, >24 months) was associated with lower recurrence and metastasis rates (HR = 0.225, 0.119 and 0.083, respectively). In a subgroup exploratory analysis, CM therapy was also a protective factor of cancer recurrence and metastasis in both stage I-IIIA (HR=0.50, 95% CI: 0.37-0.67) and stage IIIA NSCLC postoperative patients (HR = 0.48, 95% CI: 0.33-0.71), DFS was even longer among CM treatment group patients. CONCLUSIONS: Longer duration of CM therapy could be considered a protective factor of cancer recurrence and metastasis. CM treatment is associated with improving survival outcomes of postoperative NSCLC patients in China. (Registration No. ChiCTR-OOC-14005398).

Effects of Beclin 1 overexpression on aggressive phenotypes of colon cancer cells.

Beclin 1 is involved in autophagy, differentiation, apoptosis and cancer progression, and functions as a haploinsufficient tumor suppressor gene. The aim of the present study was to elucidate the function of Beclin 1 in colon cancer. A Beclin 1-expressing plasmid was transfected into HCT-15 and HCT-116 cells, and the phenotypes and associated molecules were determined. Beclin 1 transfectants were subcutaneously injected into nude mice to determine tumor growth, and proliferation and apoptosis levels using Ki-67 immunostaining and terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL), respectively. Beclin 1 overexpression inhibited viability as determined using a Cell Counting Kit-8 assay, inhibited migration and invasion as determined using a wound healing assay or Transwell assay, and lamellipodia formation by filamentous actin staining, induced autophagy as determined using electron microscopy, and light chain 3B (LC-3B) expression, and apoptosis as determined using Annexin V staining in the two cell lines (P<0.05). Beclin 1 induced G2 arrest of HCT-15 transfectants as determined using propidium iodide staining (P<0.05), whereas HCT-116 transfectants were arrested in G1 phase (P<0.05). The two transfectants exhibited increased expression of c-Myc, cyclin D1, ß-catenin, insulin-response element 1 and 78 kDa glucose-regulated protein compared with the control and mock cells as determined using the reverse transcription-quantitative polymerase chain reaction (P<0.05). Beclin 1 overexpression upregulated LC-3B and cyclin-dependent kinase 4 expression, but downregulated cyclin E expression of the cancer cell lines as determined using western blot analysis (P<0.05). Beclin 1 expression in vivo significantly suppressed the proliferation of colon cancer cells in xenograft models via inducing apoptosis by TUNEL, and inhibiting proliferation by Ki-67 expression (P<0.05). Beclin 1 overexpression may reverse aggressive phenotypes and suppress colon cancer tumor growth, and be employed as a target molecule for gene therapy of patients with colon cancer.

Genome-wide identification of transcription factors that are critical to non-small cell lung cancer.

To systematically unveil transcription factors (TFs) that are critical to lung carcinogenesis, here we conducted a genome-wide lethality screening in non-small cell lung cancer (NSCLC) cells and reported that among the 1530 TFs tested, 21 genes were required for NSCLC cell proliferation and were negatively or positively associated with overall survival (OS) of patients with NSCLC. These included 11 potential tumor suppressing genes (AFF3, AhR, AR, CBFA2T3, CHD4, KANK2, NR3C2, PTEN, PRDM16, RB1, and STK11) and 10 potential oncogenic TFs (BARX1, DLX6, ELF3, EN1, ETV1, FOXE1, HOXB7, IRX4, IRX5, and SALL1). The expression levels of IRX5 were positively associated with OS of smoker and inversely associated with OS of non-smoker patients with lung adenocarcinoma. We showed that tobacco carcinogen benzo(a)pyrene (BaP) induced upregulation of IRX5 in lung epithelial cells, and Cyclin D1 was a downstream target of IRX5. Furthermore, silencing of IRX5 by lentivirus mediated transfection of short hairpin RNA significantly inhibited tumor growth in nude mice. These results indicate that tobacco smoke can modulate TFs to facilitate lung carcinogenesis, and inhibition of IRX5 may have therapeutic potentials in NSCLCs.

Comprehensive treatment with Chinese medicine in patients with advanced non-small cell lung cancer: A multicenter, prospective, cohort study.

OBJECTIVE: To determine whether additional Chinese medicine (CM) could prolong survival and improve the quality of life (QOL) in patients with advanced non-small cell lung cancer (NSCLC) compared with Western medicine (WM) alone. METHODS: This was a multicenter, prospective cohort study. A total of 474 hospitalized patients with stage III-IV NSCLC were recruited and divided into 2 groups. Patients in the WM group received radiotherapy, chemotherapy, and optimal supportive therapy according to the National Comprehensive Cancer Network (NCCN) guidelines. In the integrative medicine (IM) group, individualized CM (Chinese patent medicines and injections) and WM were administered. The primary end point was overall survival, and the secondary end points were time to disease progression, adverse events, and QOL. Follow-up clinical examinations and chest radiography were performed every 2 months. RESULTS: The median survival was 16.60 months in the IM group and 13.13 months in the WM group (P<0.01). The incidences of loss of appetite, nausea, and vomiting in the IM group were significantly lower than those in the WM group (P<0.05). The QOL based on Functional Assessment of Cancer Therapy-Lung in the IM group was markedly higher than that in the WM group at the fourth course (P<0.05). CONCLUSIONS: Additional CM may prolong survival and improve the QOL patients with NSCLC. The adverse effects of radio- and chemotherapy may be attenuated as CM is used in combination with conventional treatments.

Beclin 1 expression is closely linked to colorectal carcinogenesis and distant metastasis of colorectal carcinoma.

Beclin 1 participates in development, autophagy, differentiation, anti- apoptosis, neurodegeneration, tumorigenesis and cancer progression. The roles of Beclin 1 in colorectal carcinogenesis and its subsequent progression are still unclear. Here, the mRNA and protein expression of Beclin 1 were determined in colorectal carcinoma and matched mucosa by Reverse transcriptase-polymerase chain reaction and Western blot. Immunohistochemistry and in situ hybridization (ISH) were performed on tissue microarryer with colorectal carcinoma, adenoma and mucosa. The expression of Beclin 1 mRNA and protein was found to be higher in colorectal carcinoma than matched mucosa by real-time PCR and Western blot (p < 0.05). According to the ISH data, Beclin 1 expression was lower in colorectal non-neoplastic mucosa (NNM) than adenoma and carcinoma (p < 0.05). Immunohistochemically, primary carcinoma showed stronger Beclin 1 expression than NNM and metastatic carcinoma in the liver (p < 0.05). Beclin 1 protein expression was negatively related to liver and distant metastasis (p < 0.05), but not correlated with age, sex, depth of invasion, lymphatic or venous invasion, lymph node metastasis, tumor-node-metastasis (TNM) staging, differentiation or serum carcinoembryonic antigen (CEA) concentration (p > 0.05). Survival analysis indicated that Beclin 1 expression was not linked to favorable prognosis of the patients with colorectal carcinoma (p > 0.05). Cox's model indicated that depth of invasion and distant metastasis were independent prognostic factors for colorectal carcinomas (p < 0.05). It was suggested that Beclin 1 expression is closely linked to colorectal carcinogenesis and distant metastasis of colorectal carcinoma.

High MUC2 expression in ovarian cancer is inversely associated with the M1/M2 ratio of tumor-associated macrophages and patient survival time.

Mucin 2 (MUC2) is a mucin molecule aberrantly expressed by ovarian cancer cells. Previous in vitro studies have indicated that MUC2 promotes cancer growth and metastasis through a tumor-associated macrophage (TAM)-dependent mechanism. However, this mechanism has never been linked to clinical oncology, and its prognostic significance needed to be clarified. Here, we collected 102 consecutive ovarian cancer specimens and used the multiple immuno-histo-chemical/-fluorescent technique to determine the correlations between the MUC2 expression status, the ratio of M1/M2 TAMs and the densities of cyclooxygenase-2 (COX-2)(+) TAMs and COX-2(+) cancer cells. The Kaplan-Meier survival analysis and multivariate Cox regression analysis were used to evaluate the prognostic influences of these parameters. As a result, we found that the MUC2 overexpression (immunostaining ++/+++) was significantly correlated with a reduced ratio of M1/M2 TAMs (p<0.001), an increased density of COX-2(+) TAMs (p<0.001) and an increased density of COX-2(+) cancer cells (p=0.017). Moreover, most of the M2 TAMs (93%-100%) and COX-2(+) TAMs (63%-89%) overlapped; and the COX-2(+) cancer cells were frequently observed near the COX-2(+) TAMs. In the Cox regression analysis, MUC2 overexpression was found to be an independent prognostic factor for ovarian cancer patients, of which the hazard ratio (HR) was 2.354 (95% confidence interval (CI): 1.031-10.707, p=0.005). Also, the reduced ratio of M1/M2 TAMs and the increased densities of COX-2(+) TAMs and COX-2(+) cancer cells were demonstrated to be the predictors of poor prognosis, among which the reduced M1/M2 ratio possessed the highest HR (1.767, 95% CI: 1.061-6.957, p=0.019). All these findings revealed that MUC2 can concurrently exert M2-polarizing and COX-2-inducing effects on TAMs, by which it causes an imbalanced TAM M1-/M2-polarization pattern and induces local PGE2 synthesis (in both TAMs and cancer cells). The positive feedback between local PGE2 synthesis and TAM M2-polarization accelerates ovarian cancer progression.

[Risk of cervical cancer and precancerous diseases in the oral HPV carriers].

OBJECTIVE: To evaluate the risk of the occurrence of cervical intraepithelial neoplasia (CIN) and invasive cervical cancer in the oral HPV carriers through a population-based investigation in Shanghai. METHODS: A total of 1200 cases of outpatients who attended the annual cervical examination and 50 preoperational cases of inpatients with CINIII or invasive cervical cancer were enrolled from three clinical centers in Shanghai. The oral HPV infection was determined by real-time PCR. In 1200-case cross-sectional study, the incidence rate of CIN was compared between the oral HPV positive and negative cohort. In 1250-case case-control study, the positive rate of oral HPV DNA test was compared among normal control group, CINI-III, and invasive cancer case groups, and all odds ratio (OR) values were calculated, respectively. The HPV transmission-related demographic and behavioral characters of the oral HPV carriers were also analyzed. RESULTS: The oral HPV carriers accounted for 5.9% (71/1200) of the investigated outpatients. The oral HPV DNA positive rates were gradually increased with the cervical disease grades, which were 5.8% (68/1182, normal), 2/13 (CIN I), 1/5 (CINII), 31.4% (11/35, CINIII) and 5/15 (invasive cancer). In cross-sectional cohort studies, the relative risks (RR) of CINI,II were 2.9 and 4.0 for oral HPV carriers, respectively. In case-control study, the OR values for CINI-III and invasive cervical cancer were 3.1(95%CI: 1.6-10.1), 4.2(95%CI: 1.7-28.4), 7.1(95%CI: 4.8-19.8) and 10.1(95%CI: 3.2-32.1), respectively. The oral sex and multi-sexual partner were two major risk factors for the oral and cervical HPV co-infection, HPV-related cervical cancer and precancerous diseases according to behavioral analysis. CONCLUSIONS: There are complicated transmission pathways between oral and cervical HPV. Oral HPV carriers should be intensively followed up and their oral HPV infection and HPV-related cervical diseases should be treated together.

Overexpression of RPS6KB1 predicts worse prognosis in primary HCC patients.

RPS6KB1 (ribosomal protein S6 kinase, 70 kDa, polypeptide 1) plays a key role in regulating protein translation. The role of RPS6KB1 in HCC (hepatocellular carcinoma) has not been fully investigated. This study was undertaken to determine the clinicopathological features and prognostic value of RPS6KB1 in HCC. We examined RPS6KB1 expression in 30 paired liver cancer tissues and adjacent noncancerous tissues by reverse transcription real-time PCR and Western blotting. In addition, we analyzed RPS6KB1 expression in 87 HCC samples by immunohistochemistry. The expression of RPS6KB1 was significantly increased in cancer tissues. Clinicopathological analysis showed that the expression of RPS6KB1 was significantly correlated with tumor size, histopathologic classifications, and serum alpha-fetoprotein (AFP). Kaplan-Meier survival curves revealed that increased expression of RPS6KB1 correlated with poor prognosis of HCC patients. RPS6KB1 expression was an independent prognostic marker for overall survival of HCC patients by multivariate analysis. Our data suggest that RPS6KB1 may play an important role in the progression of HCC and could serve as a potential molecular target for HCC therapy.

Identification of a gene-expression signature for predicting lymph node metastasis in patients with early stage cervical carcinoma.

BACKGROUND: Pelvic lymph node metastasis (PLNM) is an important prognostic factor for patients with cervical carcinoma. The objective of this study was to identify a gene-expression signature that could predict PLNM in cervical carcinoma. METHODS: Eighty-eight women with cervical carcinoma with PLNM (n = 23) and without PLNM (n = 65) were divided randomly into a training group and a test group. An oligonucleotide microarray that contained probes for 1440 human cancer-related genes was fabricated in-house and was used to detect the gene expression profile of cervical carcinoma. The gene expression levels detected in the microarray were verified by quantitative reverse transcriptase-polymerase chain reaction (qRT-PCR). RESULTS: A gene-expression signature for predicting PLNM was developed in patients from the training group, including 11 genes: ribosomal protein L35 (RPL35); thymosin ß 10 (TMSB10); tyrosine 3-mono-oxytenase/tryptophan 5-mono-oxygenase activation protein, ζ polypeptide (YWHAZ); biotinidase (BTD); lactate dehydrogenase A (LDHA); glucuronidase ß (GUSB); superoxide dismutase 2 (SOD2); nuclear receptor subfamily 3, group C, member 2 (NR3C2); fructosamine 3 kinase (FN3K); x-ray repair cross-complementing 4 (XRCC4); and wingless-type mouse mammary tumor virus integration site family member 2 (WNT2). In the test group, the signature's accuracy, sensitivity, specificity, positive predictive value, and negative predictive value were 91%, 90.9%, 93.9%, 83.3%, and 96.9%, respectively, for predicting PLNM. The expression levels of 5 genes in the signature were confirmed by qRT-PCR. A multivariate analysis demonstrated that patients with 11-gene high-risk scores were had a 33-fold increased risk for PLNM compared with patients who had low-risk scores. The 5-year overall and disease-free survival rates for patients who had 11-gene high-risk scores were marginally significantly lower than the rates for patients who had 11-gene low-risk scores (P = .087 and P = .174, respectively). CONCLUSIONS: In this study, 11-gene signature for predicting PLNM in cervical carcinoma was identified that may help clinicians in planning therapy for patients with cervical carcinoma.

[Effect of berberine on the differentiation and apoptosis of K562 cell line].

OBJECTIVE: To study the effect of Berberine on proliferation, differentiation and apoptosis of K562 cells for supplying the theoretical evidence on the clinical application of Coptis chinensis to cure chronic myeloid leukemia. METHODS: The proliferation-inhibiting capability of K562 cells was investigated by MTT assay and colony conform test. The apoptosis effect of Berberine on K562 cells were analyzed by Wright's-Giemsa staining; DNA fragmentation was performed by agarose gel electrophoresis. The cell cycle distribution and the cell surface marker-cluster of differentiation were determined by flow cytometry. RESULTS: Berberine effectively inhibited the proliferation of K562 cells in a dose and time-dependent manner. In addition, when combined with different concentrations of Ara-C, the cells' viability percentage was prominently higher than only Berberine used. Treated with Berberine for 48 hours, the cells could be induced differentiation towards erythrocyte, granulocyte and megakaryocyte and with the treated time extending, the percentage of apoptosis cells gradually increased. CONCLUSIONS: Berberine can efficiently inhibit the proliferation of K562 cells, maybe by the way of blocking cells at the stage of G0/G1 and (or) G2, then leading to its apoptosis and differentiation.

Nm23-H1 regulates the proliferation and differentiation of the human chronic myeloid leukemia K562 cell line: a functional proteomics study.

AIMS: Nm23-H1 is a suppressor of metastasis that has been implicated in the regulation of proliferation and differentiation of hematopoietic cells, although specific mechanisms for Nm23-H1 have not been well-characterized. Our study is designed to further elucidate the role of Nm23-H1 in the human chronic myeloid leukemia K562 cell line. MAIN METHODS: In this study we generated and selected two cell clone pools of human chronic myeloid leukemia K562 cells with up-regulated and down-regulated Nm23-H1 expression. KEY FINDINGS: Our data show that knockdown of Nm23-H1 decreased proliferation and increased the percentage of cells arrested in the G0/G1 phase of the cell cycle. Correspondingly, K562 cells overexpressing Nm23-H1 were more proliferative. After treatment of these two cell types with phorbol 12-myristate 13-acetate (PMA) for 48 h, cells with reduced Nm23-H1 expression had a higher percentage of 8N ploidy and higher expression of CD41 than K562 cells overexpressing Nm23-H1. A functional proteomics analysis identified ten proteins, including ANP32A, Cdc42GAP, and the isoform 2 of SET, whose expression levels were significantly altered by down-regulation of Nm23-H1. In addition, cells with decreased levels of Nm23-H1 had significantly reduced expression of Cdc42 independent of treatment with PMA. The interaction of the endogenous Nm23-H1 and Cdc42 proteins has been further validated by reciprocal immunoprecipitations. SIGNIFICANCE: We provide data that complement functional studies of Nm23-H1 in regulating hematopoietic cells, and address action mechanisms of Nm23-H1 that have not previously been reported.

[Influence of nm23-H1 gene silence in K562 cell on its differentiation toward megakaryocyte].

OBJECTIVE: To construct a stable nm23-H1-knock-down cell model with K562 cell line and study its differentiation toward megakaryocyte. METHODS: Eukaryotic expression vector pSilencer 4.1-CMV-sinm23 expressing siRNA targeting nm23-H1 was transfected into K562 cells with lipofectamine2000. Cells with stably nm23-H1 silence were screened out by G418. Real-time quantitative PCR, immunocytochemistry, western blot were used to confirm the nm23-H1-knock-down K562 model. Cell differentiation capacity was detected by NBT reduction assay. Surface antigen Gp IIb-IIIa (CD41) of knock-down cells treated with phorbol 12-myristate 13-acetate was analyzed by flow cytometry. Western blot was used to detect the ERK1/2 signal pathway after the stimulation of phorbol 12-myristate 13-acetate. RESULTS: Endogenous nm23-H1 was silenced by pSilencer 4.1-CMV-sinm23 and the silence efficiency was up to 75% and 70% in mRNA and protein levels respectively compared with the mock cells. Under phorbol 12-myristate 13-acetate treatment, the knock-down cells displayed a significantly increased differentiation ability toward megakaryocyte compared with control. The NBT reduction values were (0.31 +/- 0.07) and (0.23 +/- 0.05) respectively. Further results revealed that nm23-H1 gene regulating the megakaryocytic differentiation was due in part to the increased ERK1/2 phosphorylation. CONCLUSIONS: A stable nm23-H1-knock-down K562 cell model is successfully constructed. nm23-H1 involves in regulating the megakaryocytic differentiation of K562 cell line.

[Silencing HSV1 gD expression in cultured cells by RNA interference].

To explore the anti-HSV-1 effect of silencing gD gene expression by RNA interference, five 21-nucleotide duplex small interfering RNAs(siRNAs) targeting the HSV1 gD sequence were designed and the gD-EGFP fusion gene expression vector was constructed, then co-transfected into Vero cell, and screened the effective siRNA through analyzing the intensity of the EGFP fluorescence. Finally, the anti-HSV1 effect was confirmed by plaque reduction assay, real-time PCR and daughter virus titration of HSV1 infected Vero cells transfected with siRNAs. The study demonstrated that siRNAs could effectively and specifically inhibit gD gene expression in HSV1-infected cells, but only had a little effect on HSV1 infection, so taking gD as the target of siRNA against HSV1 needs further study.

[Efficient purification of recombinant human NDPK-A in pilot-scale].

To purify recombinant human nucleoside diphosphate kinase A (rhNDPK-A) efficiently in pilot scale, cells of rhNDPK-A producing E. coli were homogenized by high pressure under 4 degrees C, 950 Pa. The insoluble debris was removed by microfiltration and the soluble portion was concentrated by ultrafiltration. The resulted crude sample was loaded on DEAE-sepharose Fast Flow. The target fraction was collected and then load on Cibacron Blue 3GA Sepharose CL-4B. Eluted with buffer containing ATP from the AC column, rhNDPK-A was polished with ultrafiltration. The results showed that after homogenized 2 rounds, 1500g cells of E. coli brought crude sample containing 47.6g NDPK-A. Treated with microfiltration and ultrafiltration, 27.3g of NDPK-A were recovered from this bacteria homogenate. After 2-step purification with column chromatography and then polished with ultrafiltration, 17.2 g rhNDPK-A were collected with purity of 96.3%. The recovery of the whole purification process was 36.2%, and the productivity of rhNDPK-A was 1.15 g per 100 g wet cells. Comparing the recovery of each purification step, it was found that the recovery of polish is higher than that of affinity chromatography, which is higher than that of ion exchange chromatography. The limit step was the process of sample pretreatment among the 4 purification steps. Combine with the fermentation results reported before, it was deduced that the productivity of rhNDPK-A was 510 mg/L. In conclusion, an easily controlled purification condition with high yield provides material for the translation researches of NDPK; In addition, it was suggested the crucial step determine the recovery of non-secretive recombinant proteins might be the process of sample pretreatment, not be the process of column chromatography.

[Preliminary study on a new sentinel lymphoscintigraphy agent 99mTc-Rituximab for breast patient].

OBJECTIVE: To develop a new imaging agent, (99m)Tc-Rituximab, for sentinel lymphoscinti-graphy and investigate its feasibility in detecting the sentinel lymph node (SLN) for breast cancer patient. METHODS: (99m)Tc-Rituximab was prepared by introducing (99m)Tc directly into the mclecule of Rituximab, thus a new kind of lymphoscintigraphy agent ((99m)Tc-Rituximab) was produced. Five Bal b/c mice and ten breast cancer patients underwent dynamic SLN mapping procedures using (99m)Tc-Rituximab. Axillary lymph node status in breast cancer patients were evaluated with the fusion images, which was processed by computer software. With ROI technique, SLN/background ratio and the rate of SLN uptake were calculated and the dynamic curve of SLN uptake was drawn. The other 61 breast carcinoma patients underwent routine lymphatic mapping. Sentinel lymph node biopsy (SLNB) and axillary lymph node dissection (ALND) were both performed in all 71 patients. Fresh SLNs and all axillary nodes were sent for pathological examination using hematoxylin and eosin (H&E) staining. RESULTS: (99m)Tc-Rituximab, with a yield of about 95.0%, can show SLN status in both mice and patients. The fusion image showed SLNs clearly, even the depth of SLNs in the axilla. The results of dynamic SLN mapping showed visible SLN starting from 10 min, up to 16 h after injecting tracer, however, secondary lymph nodes were not detectable at all. In mice, the ratio of SLN/background was 2.1, the rate of uptake was about 3.0% to 3.5%, and the equation of the curve was produced as: y = 0.036x + 2.7875, r(2) = 0.9787. For breast cancer patients, the uptake rate was different from case to case, but the cure seemed to be consistent with logarithm. The result of SLNB and ALND showed that the sensitivity and accuracy of SLNB was both 100.0%. The average number of SLNs found in each case was 2.6. Of nineteen breast cancer patients (26.8%) with lymph node metastasis, 11 were found to only have SLN metastasis. CONCLUSION: (99m)Tc-Rituximab, as a new tracer to mapping sentinel lymph node for breast cancer patient, is able to show the status of sentinel lymph node reliably. The fusing image is easy to obtain and be interpreted by the clinician.

[Analysis of the relationship between nm23-H1 gene and human chronic myeloblastic leukemia using siRNA].

To investigate the relationship between nm23-H1 gene and human chronic myeloblastic leukemia we designed siRNAs which target nm23-H1 gene. According to the principles of designing siRNA, we selected three siRNAs and transfected them into K562 cells by lipofectamine2000. The expression levels of nm23-H1 mRNA were detected by reverse transcriptase polymerase chain reaction after transfection for 24 hours. The expression levels of nm23-H1 protein were assayed by immunocytochemical method after transfection for 48 hours. And after transfection for 24, 48 and 72 hours, cell proliferation was determined by MTT method. Among the three siRNAs, siNM526 can effectively inhibit the expression of nm23-H1 on mRNA and protein levels. The growth of K562 cells was suppressed after transfection of siNM526. These results suggest that low expression level of nm23-H1 in K562 cells inhibited cell proliferation, namely reduced malignant degree of them. Therefore nm23-H1 gene might be a potential target of leukemia treatment.

Solubility of disulfide-bonded proteins in the cytoplasm of Escherichia coli and its "oxidizing" mutant.

AIM: To study the influence of redox environment of Escherichia coli (E. coli) cytoplasm on disulfide bond formation of recombinant proteins. METHODS: Bovine fibroblast growth factor (BbFGF) was selected as a model of simple proteins with a single disulfide bond and free cysteines. Anti-HBsAg single-chain Fv (HBscFv), an artificial multidomain protein, was selected as the model molecule of complex protein with 2 disulfide bonds. A BbFGF-producing plasmid, pJN-BbFGF, and a HBscFv producing-plasmid, pQE-HBscFv, were constructed and transformed into E. coli strains BL21(DE3) and M15(pREP4) respectively. At the same time, both plasmids were transformed into a reductase-deficient host strain, E. coli Origami(DE3). The 4 recombinant E. coli strains were cultured and the target proteins were purified. Solubility and bioactivity of recombinant BbFGF and HBscFv produced in different host strains were analyzed and compared respectively. RESULTS: All recombinant E. coli strains could efficiently produce target proteins. The level of BbFGF in BL21(DE3) was 15-23% of the total protein, and was 5-10% in Origami (DE3). In addition, 65% of the BbFGF produced in BL21(DE3) formed into inclusion body in the cytoplasm, and all the target proteins became soluble in Origami(DE3). The bioactivity of BbFGF purified from Origami(DE3) was higher than its counterpart from BL21(DE3). The ED(50) of BbFGF from Origami(DE3) and BL21(DE3) was 1.6 microg/L and 2.2 microg/L, respectively. Both HBscFv formed into inclusion body in the cytoplasm of M15(pQE-HBscFv) or Origami(pQE-HBscFv). But the supernatant of Origami(pQE-HBscFv) lysate displayed weak bioactivity and its counterpart from M15(pQE-HBscFv) did not display any bioactivity. The soluble HBscFv in Origami(pQE-HBscFv) was purified to be 1-2 mg/L and its affinity constant was determined to be 2.62 x 10(7) mol/L. The yield of native HBscFv refolded from inclusion body in M15(pQE-HBscFv) was 30-35 mg/L and the affinity constant was 1.98 x 10(7) mol/L. There was no significant difference between the bioactivity of HBscFvs refolded from the inclusion bodies produced in different host strains. CONCLUSION: Modification of the redox environment of E. coli cytoplasm can significantly improve the folding of recombinant disulfide-bonded proteins produced in it.