AIM:To study if low dose NaNO2 can induce the adaptive response of cultured Chinese hamster lung cells(CHL cells)to DNA damage.METHODS:Single cell gel electrophoresis technique was used to detect the DNA damage in CHL cells exposed to NaNO2 at different concentrations.CHL cells were pretreated with NaNO2 of concentrations of 0.01 mg/L,0.1 mg/L and 1 mg/L respectively.And the adaptive response to the toxicity of 1g/L NaNO2 was observed.The activity of polyADP-ribose polymerase(PARP-1) of CHL cells was inhibited with 3-aminobenzamide(3AB) before or after pretreated with low dose of NaNO2.And the changes of the adaptive response were observed.RESULTS:The rate of tailing cells was 7.87% when the cells were exposed to 1 g/L NaNO2 without pretreatment with low dose NaNO2.An extremely remarkable statistics significance(P0.05).The adaptive response could be blocked when the activity of PARP-1 was inhibited with 3AB before the low dose pretreatment,but could not be blocked when the activity of PARP-1 was inhibited after low dose NaNO2 pretreatment 6 h.CONCLUSION:NaNO2 of concentration that equals to or lowers than 0.1 mg/L can induce the adaptive response of cultured CHL cells to DNA damage caused by high dose NaNO2 through PARP-1 activation.And the dose of NaNO2 that can induce adaptive response might not cause the DNA damage.

The tumor stem cell theory supposed that tumor stem cells are the origin of tumor abnormal proliferation,invasion,metastasis,drug resistance and recurrence.As the theory is put forward,it redefines the functions of classic stem cells in tumorigenesis.It is a great event for recent studies on glioma initiating cells as brain tumor stem cells were identified and isolated successfully.A lot of evidence from experiments in vivo and in vitro demonstrates that brain tumor stem cells might play an important role in glioma tumorigenesis.In this review,we discuss the relationship between tumor stem cells and tumorigenesis,and the research on the correlation between brain tumor stem cells and glioma genesis.

p73, a first p53 relative, has recently been identified as a new structural and functional homologue of the transcription factor p53. However, it is unclear whether this protein functions as a tumor suppressor. p73L, a second human p53-related gene, which shows strong amino-acid similarity to p73. In this article, we shall discuss the cloning, location, expression and functions of these two new candidate tumor suppressor genes and look forward to the future study.

PTEN is a candidate tumor suppressor which has sequence homology with dual-specificity phosphatase. PTEN is a multifunctional protein endowed with a phosphatase activity capable of dephosphorylating both tyrosine phosphate, serine/threonine phosphate residues on proteins and phospholipids of the phosphatidylinositol pathway. PTEN appears to be mutated at considerable frequency in several types of human tumors, including those from brain, breast, endometrium, and prostate. PTEN play an important role in pathogenesis of tumor, tumor cell invasion and metastasis. In this review, we will discuss the chemical structure of PTEN, its phosphatase activity, the ability of affecting signal transduction, and its mutational status in cancer.

Phage peptide libraries are collections of the specific length of short peptides,and they are based on phages as their carriers.They include mimotope libraries and peptide antibody libraries.Phage-displayed peptide libraries have been used to isolate specific ligands for numerous protein targets,and they have been proven useful in defining antigen momitopes,rapid determination of binding energetics at protein-protein interfaces,designing of vaccine and tumor research aspects.This review summarized the research progression of phage peptide library.

MicroRNAs (miRNAs) are critical regulators of gene expression. These small, non-coding RNAs are believed to regulate more than one third of protein-coding genes, and have been implicated in the control of many biological processes, including the biology of glioma. The functional significance in some of the miRNAs begins to emerge. This paper reviews the biogenesis of miRNAs, their roles in neuronal development and tumorigenesis of gliomas, and their contribution as tumor biomarkers. Research in this area is quickly gathering pace and is illuminating important aspects of the diseases that may ultimately lead to novel therapeutic interventions, as well as diagnostic and prognostic tools for brain tumors.

AIM:To investigate effect of recombinant human thrombopoietin on exsanguine thrombocytopenia mice. METHODS:Normal peripheral platelet counts were performed on sample obtained from the tail vein of purebred Babl/c mice including experimental and control groups before experimentation. rhTPO was injected into the mice by intraperitoneal injection once a day for 7 days. On the seventh and the fourteenth day, the mice were phlebotomized from the supra-obitalis vein in order to make exsanguine thrombocytopenia animal model. At the same time, we observed the biological activity of recombinant human thrombopoietin in vivo and the mice's death rate. RESULTS: On the seventh day and the fourteenth day, platelet counts of mice treated by rhTPO were higher than those by PBS (P＜0.05). Moreover the platelet counts of mice in experimental group of rhTPO showed increasing tendency following experimental days. In addition, death happened in two groups after those mice were phlebotomized from the supra-obitalis vein, but the death rate in negative control group was evidently higher than that in experimental group (P＜0.05). CONCLUSION:rhTPO had obvious biological activity in increasing platelet production, which resulted in the drop in thrombocytopenia mice's death rate.

Currently, platelet transfusion is the primary treatment for thrombocytopnia which results from intensive chemotherapy and radiotherapy of cancer. While repeated platelet transfusions are associated with several problems. The clinical availability of safe and effective platelet growth factors is eagerly awaited. Currently, a mumber of hematopoietic growth factors with thrombopoietic activity have been identified. This review discusses the biological characteristics and the clinical trial investigation development of platelet growth factors.

Objective:To investigate the relationship of-308bp polymorphism in tumor necrosis factor-α (TNFa)gene and+252bp in lymphotoxin-α(LTα)gene with the clinical course and outcome of non-Hodgkin's lymphoma(NHL).Methods:The single base change in TNFα gene and LTα gene was analyzed among 96 Chinese patients with NHL and 72 normal controls by using PCR-restrictive fragment length polymorphism (RFLP).The clinical data were collected and survival analysis was performed.Results:In NHL patients,no statistcally significant association was found between the presence of a given TNF/LT haplotype status and clinical variables such as age,seX,disease stage,and so on.The patients carrying low-risk haplotype achieved a more sensitive response to first-line therapy than that in patients with high-risk haplotype(70.4%v 45.2%:P=0.018).The estimated 1-year progression-free survival rates in the high-risk and low-risk groups were 66.67% and 87.5%,respectively(log-rank test,P=0.0231).Kaplan-Meier method showed that the estimated 2-year and 4-year overall survival rates were 39.95%and 8.32%in patents carrying high-risk haplotypes and 65.13%and 46.52%in patients carrying low-risk haplotypes,respectively(log-rank test,P=0.0012).In multivariate Cox regression models.the TNF/LT haplotype status was found to be a dsk factor for outcome of NHL (P=0.034).Conclusion:There is an association between TNF/LT haplotype status and response to therapy and outcomes of NHL in Canton area,China.Detecting TNF/LT haplotype may be a sensitive method to evaluate the outcome of NHL.

Traditional concept has been that hematopoietic stem cells (HSC) are tissue-specific stem cells, which are restricted to generate the cell types of the blood and immune system. However, recent studies have shown that there is a higher plasticity of the HSC than previous expected, it can be induced to transdifferentiated into mature cells of other nonhematopoietic organs after transplantation in vivo. In this article, the recent advances in the plasticity of HSC and its potential clinical application are reviewed.