| Cancer is one of the serious harmness to public health diseases.The incidence and mortality rates are increasing,and it has become the first cause of death disease.With the rise of science and technology development as well as second-generation sequencing technology,the in-depth study of tumor genes and proteins at the molecular level has shown that: many genes and malignant features staging,recurrence and metastasis of tumor protein closely related to these genes and proteins in the process of tumor formation and progression played an extremely important function.There is the possibility of becoming future therapeutic gene or protein in tumor precise molecular targets.Therefore,the study of tumor proliferation and molecular mechanisms of HCC metastasis cells,finding new ways to be early and accurate prediction tumorigenesis,metastasis and prognosis of diagnostic markers and taking timely and effective prevention and treatment measures,can effectively improve the prognosis of cancer patients.The comprehensive treatment of patients with tumors has important significance.The incidence of Ovarian cancer(OV)in the female ranked third,behind only breast cancer and cervical cancer.Ovarian cancer is one of the highest mortality rates among gynecological malignancies.Recent statistics showed that in 2012 only the United States,new cases of ovarian cancer patients was 22240 people,of which more than 50% of ovarian cancer patients are expected to die within a year.Particularly,ovarian cancer pathogenesis is not yet entirely clear,because ovarian cancer insidious onset,early onset and no specific clinical manifestations,resulted in the majority of patients to the hospital diagnosed when the body has occurred tumor metastasis and violated.Statistics showed that in patients with ovarian cancer,thefive-year survival rate was about 50%,but more than 80.0 percent of patients with advanced ovarian cancer presented cancer recurrence and metastasis,thus resulting in poor prognosis of patients with ovarian cancer.Currently,the treatment of ovarian cancer mainly included surgical excision therapy and postoperative chemotherapy treatment.At present,the major programs in clinical ovarian cancer are postoperative combination chemotherapy with paclitaxel or platinum-based based on cytoreductive surgery.Complete remission rate of ovarian cancer patients using this program can reach 70%-80%.But chemotherapy drugs have serious adverse and drug reactions,and the main component of chemotherapy drugs to cytotoxic drugs mainly produce a series of side effects which greatly limit clinical applications of chemotherapy drug regimens,and in turn leads the difficulty of chemotherapeutic agents in complete removal of residual tumor cells in the body,eventually leading to failure of the clinical treatment of ovarian cancer,such as cancer recurrence or metastasis,resulting in a poor prognosis in ovarian cancer patients.With the development of health science and technology,surgical removal of ovarian cancer based on the chemotherapy programs in recent years has obtained the rapid development and progress.But due to the difficulty of early diagnosis of ovarian cancer,the vast majority of ovarian cancer patients in treatment tumors and vascular invasion are very prone to the cancer metastasis in abdomen,liver and lung or distant metastasis.Thus,the diagnosis and treatment of metastatic ovarian cancer have been an urgent problem.In clinical diagnosis,early diagnosis and early warning of malignant tumors is very important,which depends on the non-invasive detection of early tumor markers.For the patients with ovarian cancer,serum diagnostic marker including CA125 is currently the most widely used in clinical ovarian cancer.Clinical trials with a large sample demonstrated that the sensitivity of CA125 applications in ovarian cancer diagnosis is about 80%.However,serological diagnostic marker of CA125 presented a poor specificity in early diagnosis of advanced ovarian cancer.Numerous studies have confirmed that in many gynecological benign and malignant diseases,such as ovarian cysts,pregnancy,uterine fibroids,pelvic inflammatory disease,endometriosis,appendicitis,endometrial cancer,lung cancer and pancreatic cancer,the expressionlevels of CA125 are likely to be abnormal,resulting in a further improvement of sensitivity and specificity of CA125 [18,19].Due to a poor sensitivity and specificity of CA125,finding a new tumor marker with strong specificity and high sensitivity for ovarian cancer diagnosis and early warning,and even digging new therapeutic target for ovarian cancer,will be very important in clinical and social significance.In the clinical treatment of ovarian cancer,the application of cytoreductive surgery combined with chemotherapy in ovarian cancer can be reached 50% of five-year survival,but for patients with advanced ovarian cancer with recurrence and metastasis,the five year survival rate is only one of three.Therefore,the current status of ovarian cancer treatment: Traditional chemotherapy is limited to improve the prognosis of patients with ovarian cancer effects,thus most patients with advanced ovarian cancer ultimately died of metastasis and chemosensitivity of tumor recurrence.Randomized controlled clinical trials of large sample showed: for ovarian cancer first-line drug of choice for the platinum/taxane,it is possible to generate more than 80% of total drug response rate and about 50% of the drug complete response rate.Currently the sensitivity of ovarian cancer chemotherapy drug included platinum-sensitive and platinum-resistant and platinum-resistant refractory three types.Although most ovarian cancer patients were sensitive to chemotherapeutic drugs,but the application of chemotherapy could still not completely eradicate cancer cells in vivo.Therefore,looking for a sensitive and specific diagnostic and therapeutic marker in the early diagnosis of ovarian cancer,as well as finding an effective target for drug treatment is very important.Therefore,clarifying the mechanism of malignant ovarian cancer invasion and metastasis,is undoubtedly of great importance for improving the prognosis of patients with ovarian cancer.Based on these problems,researching new ways to inhibit the invasion and metastasis of ovarian cancer cells seems particularly important.More and more studies beginning to explore the physiological mechanism of cellular and molecular mechanisms OV,hoping to find new ways to treat ovarian cancer.OV complex pathophysiological processes,with the OV-depth study of the genetic and molecular level,an increasing number of genes and proteins associatedwith malignant characteristics were found to typing and staging of ovarian cancer recurrence and metastasis is closely related to.OV and the development of any part of steps are likely to become available in our medical molecular targets so,ovarian cancer proliferation and metastasis molecular mechanisms accurately predict the prognosis of patients,prevention of ovarian cancer metastasis,and to take effective preventive treatment is to improve the efficacy of ovarian cancer patients,improve ovarian cancer prognosis breakthrough,shifted from molecular diagnosis of ovarian cancer,choose new,effective,side effects of treatment intervention and treatment are of great significance.Cadherin has been become a calcium-dependent adhesion proteins,extracellular cadherin repeats of 110 amino acid residues,which belongs to the family of cell adhesion molecules one.Based on the similarity cadherin sequence cadherin it has been divided into several subfamilies: desmosomes cadherin,cadherin classical cadherin and cadherin(protocadherins,PCDHs).Wherein PCDHs family according to their genomic structure,it can be divided into two large groups: non-aggregating PCDHs and aggregation PCDHs.Currently,about PCDHs features have been widely reported.Studies have shown that PCDHs widely involved in the formation of the embryonic nervous system matures and neural circuits.Studies have also indicated that,PCDHs in the process of some neurological diseases also play an important role,such as autism,cognitive disorders,schizophrenia and so on.And the current mainstream view is still the main PCDHs by mediating cell adhesion and indirectly regulate effector molecules exert their biological function.PCDH8 protein is a member of the cadherin superfamily,which encodes an integral membrane protein by mediating cell adhesion function.At the molecular structure,and typical cadherin PCDH8 different,generally composed of typical cadherin exons 15-17 coding composition,and PCDH8 coding genes with only three exons.Which deserves special attention is PCDH8 first exon gene encoding the extracellular domain,including six protein domain and a transmembrane domain.Currently,a large number of studies have confirmed gastric cancer,oral cancer,breast cancer,bladder cancer,nasopharyngeal carcinoma was significantly down-regulatedgenes PCDH8,and in these tumor tissues PCDH8 gene promoter methylation have significant abnormal levels.Some scholars through 45 cases of gastric carcinoma detected: with respect to adjacent tissues,PCDH8 gene promoter methylation is more common in gastric cancer,cancer tissue methylation ratio of 57.78%,while the adjacent non-tumor tissue methylation ratio was 42.1%,and in normal gastric mucosa is found PCDH8 methylation.Statistics showed that gastric cancer tissues and adjacent normal tissues,no significant differences PCDH8 gene methylation level,but gastric cancer tissues and normal gastric mucosa,there was a significant difference between adjacent tissues and normal gastric mucosa PCDH8 gene methylation level.And researchers to further clinical and pathological data analysis found that there is no lymph node metastasis in gastric cancer tissues and different degrees of differentiation,PCDH8 gene promoter methylation levels were significantly different,Logistic regression analysis showed that lymph node metastasis and PCDH8 gene methylation It is closely related to,and ultimately concluded PCDH8 gene promoter methylation is a potential tumor suppressor gene gastric cancer,has played an important role in the development of gastric cancer.Numerous studies have demonstrated PCDH8 play in the progress of a variety of human malignancies an important role in down-regulated expression of abnormal or absent in tumor tissues and tumor cell lines,may be new,potential tumor suppressor gene,and was confirmed PCDH8 it may be due to abnormal expression of its promoter methylation due.Clinical data analysis found that the relationship PCDH8 and clinical pathology of various tumors and found PCDH8 methylation level and degree of malignancy,survival prognosis.These studies show that,PCDH8 may become malignant early warning diagnosis and prognosis of a novel molecular markers?And the application of the demethylation agent 5-Aza treatment,PCDH8 gene expression levels of various malignant tumor cell lines have been restored,suggesting that the demethylating drugs in the treatment of cancer has great application prospects.Although,PCDH8 research in recent years has made great progress,but the impact of tumor specific mechanism and possible development of specific signaling pathwaysis not yet entirely clear,the research applied to clinical cancer early diagnosis and treatment has yet to be further development and in-depth discussion.First part: the relationship between PCDH8 expression and clinical prognosis in ovarian cancerObjective:To investigate the relationship between PCDH8 expression and clinical prognosis in ovarian cancer.Methods:1.Western Blot was used to detect the expression of PCDH8 protein in ovarian cancer tissues and the corresponding tissue adjacent from 8 ovarian cancer patients.2.The relationship between PCDH8 expression and clinical prognosis in ovarian cancer were analyzed by immune-histochemical and tissue chip-technology.Results:1.The expression of PCDH8 was low in ovarian cancer cells compared with normal ovarian epithelial cell.2.The expression of PCDH8 was significant low in ovarian cancer tissues compared with the corresponding tissue adjacent(P< 0.05).3.There were significant negative relationships between PCDH8 expression in ovarian cancer and clinical pathological parameters of patients such as prognosis(P=0.029),metastasis(P=0.048),FIGO(P = 0.0065)and recurrence(P =0.0011).But there were no relationship between PCDH8 expression in age,CA-125 level,.Moreover,lower expression of PCDH8 could be an independent risk,which indicated the poor prognosis of patients with ovarian cancer(P<0.01).Kaplan Meier analysis showed the survival time of patients with low PCDH8 was significantly poorer than patients with high PCDH8,suggesting that the expression of PCDH8 was closely related to the prognosis of ovarian cancer patients.Second part: the effect and molecular mechanism of PCDH8 on biological behavior of ovarian cancer cellObjective:To explore the role and molecular mechanism of PCDH8 in the proliferation,invasion and metastasis of ovarian cancer.Methods:1.Using a lentivirus was constructed overexpression of PCDH8 in the ovarian cancer cell line and RT-PCR and Westernblot were used to identify successful overexpression of PCDH8 in the ovarian cancer cell line.2.The proliferation,apoptosis,invasive ability,migration ability and clone forming of oarian cancer cells were determined by MTT,flow cytometry,scratch test and clone forming experiment.3.Application of gene chip technology research after PCDH8 gene silence in ovarian cancer cells,the changes of cell transcriptome m RNA gene expression profile were analyzed after PCDH8 gene silencing and the GO,KEGG analysis were used to analyze the influence of PCDH8 gene.Results:1.PCDH8 gene expression were inhibited in ovarian cancer cells after lentivirus transfection.2.After overexpression of PCDH8 gene in ovarian cancer cell line,the proliferation,migration and tumor capacity were significantly decreased.3.Gene analysis found that 112 genes were changed(2 folds change or higher,P< 0.05)after PCDH8 gene silence,48 increased expression and 64 decrease expression.5.GO functional annotations found that differentially expressed genes are mainly concentrated on the cell apoptosis,epithelial growth,multicellular organisms macromolecules metabolic process.At the same time,KEGG pathway analysis also found a similar result.These differentially expressed genes are mainly concentrated in the extracellular matrix receptor interactions,tumor pathway,drug metabolism,toll-like receptor pathway and so on.Third part: the effect of PCDH8 on biology behavior of ovarian cancer cell in nude miceObjective:To observe the effect of PCDH8 on biology behavior of ovarian cancer cell in vivo by building PCDH8 stable expression of ovarian cancer cell lines,and subcutaneously injecting into nude mice.Methods:1.PCDH8 stable expression of ovarian cancer cell lines were builded and subcutaneously injected into nude mice.2.tumor growth were observeResults:1.In vivo experiments confirmed that PCDH8 expression in ovarian cancer could inhibit the proliferation,tumor volume growth compared with transfection empty virus in nude mice.2.The immunohistochemical confirmed that after overexpression of PCDH8.Conclusion:1.The expression of PCDH8 was significant low in ovarian cancer,were closely related to the metastasis,recurrence rate in patients.Meanwhile,the survival time of patients with high PCDH8 expressed was significantly longer than patients with low expression of PCDH8.2.Overexpression of PCDH8 inhibited the proliferation,migration,invasion ability and tumor capacity of ovarian cancer cells,increased the apoptosis rate significantly in vitro and in vivo.These data indicated that PCDH8 might be an suppressor genes during the initiation and progression of ovarian cancer.3.This study revealed that PCDH8 could be considered as a therapeutic targets in ovarian cancer. |
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