Expression Of NKX3.1 And PTEN Genes In Prostate Carcinoma Tissue And The Studies For PC3 Cell Line Transfected By NKX3.1

BACKGROUND: Homeobox genes were firstly found in Drosophila Bagpipe, exist broadly in thecreatures from yeast to human being. Containing a 183bp ribonucleotide fragmentnamed Homeobox, all homeobox genes play a role of eukaryotic transcriptional factor.Homeobox genes are important regulators in embryogenesis, recent findings suggestthat they are closely related to some malignant neoplasm's genesis, development, asregulator of cell differentiation. Homeobox genes Nkx3.1 maps to mid-region ofmouse chromosome 14, has topmost homogeneity with homeobox gene NK family.Human's Nkx3.1 has been written as NKX3.1,with 3266bp full cDNA length, 705bpopen reading frame(ORFs),maps to chromosome 8p21,just the "hot spot"superposition site that frequently lost in prostate carcinoma. Researches suggest thatNKX3.1 nearly only expresses in prostate tissue, has higher specificity than prostatespecific antigen(PSA);its mRNA transcriptional level is regulated by androgen; playsa important role in the genesis, differentiation, development and function maintenanceof prostate organ. In addition, some experimental results indicate that depletion ofNKX3.1 expression is strongly related with hormone-resistance prostate carcinomaand late phase prostate cancer; in vitro Nkx3.1 can suppresses the growth of Nkx3.1loss-of-expression prostate carcinoma cell, tumor growth ability decreases afterinoculation into nude mouse; in those enhanced-age Nkx3.1 null mutant mice inducedby genetic engineering method, prostatic intraepithelial neoplasia(PIN) has beenfound, and resemble the findings in human tissue; in experiments, the mice ofcompound loss-of-function of Nkx3.1 and PTEN genes developed invasive prostaticcarcinoma, and lymph node metastasis were confirmed; these demonstrate thatNkx3.1 loss-of-function is a critical event in prostate cancerinitiation.— herein,Nkx3.1 may be a new prostate tissue specific candidatetumor-suppressing gene.NKX3.1 normal mutation doesn't influence its function, itscoding region hasn't been found mutation in prostate cancer pathological tissue, so itsloss-of-function manner may be expression depletion but not mutation. PTEN is abroad spectrum tumor-suppressing gene found in recent years, maps to 10q23,afrequently lost in progressing-phase prostatic cancer, thus PTEN has been regarded asa central regulator in prostatic carcinogenesis. This study plans to use immunohistochemical technique, to examine expression ofprostate specific homeobox gene NKX3.1 and tumor-suppressing gene PTEN in aserial specimen of prostate malignant tumors, and probe into the relationship betweenthese two genes; by mature liposome-induced gene transferring technique currentlybroadly used in molecular biology labs, using a eukaryotic gene expression vectorpcDNA3.1(+)-NKX3.1 which carrying NKX3.1 cDNA(ORFs) full length sequences,we plans to transfect NKX3.1 loss-of-expression human androgen-independentprostatic cancer cell line PC3, obtain the cell line PC3-NKX3.1 which stablyexpresses NKX3.1 protein, and investigate the biologic effects that derived fromNKX3.1 transfection. Moreover, we will inoculate nude mice with these cells, to 5explore the change of tumor-growth ability in nude mice, and discuss biologicfunction and significance of NKX3.1 gene, and to provide experimental evidence forits possible utilities as a tumor marker and gene-therapy target site in the future.Part I Immunohistochemical Research on the Expression of Prostate Specific Homeobox NKX3.1 & Tumor Suppressing Gene PTEN in Prostatic Carcinoma TissuesOBJECTIVE To investigate the expression of prostatic specific homeobox gene NKX3.1 andtumor suppression gene PTEN in prostate malignant tumors and benign prostatehyperplasia tissue specimen by immunohistochemical assay method, and analyse therelationship between the two genes.MATERIAL AND METHODS Prostate maligna...