The deoxyribonucleic acid-repair protein O-6-methylguanine-deoxyribonucleic acid methyltransferase is a major determinant of resistance of cells to various alkylating drugs. Its expression profile is different in different cancer types. Here, we studied the expression and function of O-6-methylguanine-deoxyribonucleic acid methyltransferase in clear cell renal cell carcinoma. The expression of O-6-methylguanine-deoxyribonucleic acid methyltransferase was evaluated in clear cell renal cell carcinoma tissues and cell lines by quantitative real-time polymerase chain reaction and immunohistochemistry. The relationship between O-6-methylguanine-deoxyribonucleic acid methyltransferase expression and clinicopathological characteristics was analyzed. To further investigate the function of O-6-methylguanine-deoxyribonucleic acid methyltransferase in clear cell renal cell carcinoma resistance to alkylating agents, siRNA targeting O-6-methylguanine-deoxyribonucleic acid methyltransferase were used to silence the O-6-methylguanine-deoxyribonucleic acid methyltransferase expression. We found that O-6-methylguanine-deoxyribonucleic acid methyltransferase is over-expressed in clear cell renal cell carcinoma tissues and cell lines. O-6-methylguanine-deoxyribonucleic acid methyltransferase expression is related with tumor progression in clear cell renal cell carcinoma patients. Up-regulation of O-6-methylguanine-deoxyribonucleic acid methyltransferase plays a critical role in primary resistance to alkylating agents. The overexpression of O-6-methylguanine-deoxyribonucleic acid methyltransferase contributes to resistance of clear cell renal cell carcinoma to standard chemotherapy. Our results have significance for understanding a new pathway of the development of drug resistance of clear cell renal cell carcinoma.

Objective To analyze the expression patterns of p53βin RCC at the mRNA levels and their associations with clinical and pathologic factors,and to explore the mechanism of p53B activity in RCC.Methods mRNA expression levels of p53 and p53βwere detected using RT - PCR followed by nested PCR.The data were also analyzed with clinicopathological features by x~2 test or Fisher's exact test.Results p53 mRNA was expressed in all tumors and matched clinically normal tissue adjacent to the tumour.p53βmRNA was significantly overexpressed in tumour samples(P 0.001),and correlated with tumour stage.Conclusions p53βmight play an important role in the tumor formation in RCC and might be used as a new marlcer and target for RCC.

BACKGROUND Several isoforms of p53 have been reported, which may have varying functions and expressions. This study aimed to analyze the expression patterns of p53 isoforms in renal cell carcinoma (RCC) at the mRNA and protein levels and their associations with clinical and pathologic factors to explore the mechanism of p53 isoforms' activity in RCC. METHODS The specimens of tumours (T) and clinically normal tissues (N) adjacent to them were collected from 41 patients with RCC. mRNA expression levels of p53 isoforms were detected using RT-PCR followed by nested PCR. Protein expression levels were detected using immunohistochemisty and Western blotting with the anti-p53 antibodies DO-1 and DO-12. The data were analyzed with clinicopathological features by chi(2) test or Fisher's exact test. RESULTS p53 mRNA was expressed in all tumours and matched clinically normal tissue adjacent to the tumour. All six isoforms could be detected in tumour and normal tissues, with the exception of the Delta133p53beta isoform, which was not detected in the normal tissue. Of the six isoforms, p53beta mRNA was significantly overexpressed in tumour samples (P < 0.001), and correlated with tumour stage. Nested PCR results consistently indicated the presence of p53gamma (19T/22N), Delta133p53 (33T/26N), Delta133p53beta (2T/0N), and Delta133p53gamma (13T/9N). Immunohistochemical analysis showed that p53 was expressed only in tumour tissues and correlated with tumour stage and grade. The results of Western blotting analysis were consistent with these findings. CONCLUSIONS Although all six isoforms are present in RCC, their function in tumour development or progression might be different. Our findings suggest that p53beta might play an important role in the formation of RCC and it might be used as a new predictor and therapeutic target for RCC.

OBJECTIVES:The sympathetic nervous system and hypothalamic-pituitary-adrenal axis have been known to be reactive to psychological factors such as stress in which several humoral factors are released. Growing data suggest that stress conditions could be associated with the development or aggravation of prostatic disease. The present study aims to investigate the influence of chronic stress and blockade of the sympathetic nerve on rat prostate.METHODS:We used 2 weeks of restraint water-immersion stress to induce a chronic psychological stress model of Wistar rats. Denervation of the peripheral sympathetic nerve was done by 6-hydroxydopamine (6-OHDA). Blood flow of ventral prostate, plasma catecholamine and cortisol were measured at the end of the experiment. The weight and secretions of dissected prostate lobes were measured and histology was performed by hematoxylin and eosin stain.RESULTS:After 14 days of stress, the blood flow of ventral prostate decreased and plasma cortisol increased. The apparent proliferation of epithelium of ventral lobes were observed and dorsolateral ones were almost unaffected. On the other hand, the hyperplasia changes were not seen after the chemical sympathectomy had been done during stress.CONCLUSIONS:Chronic stress may lead to hyperplasia of ventral prostate, the overactivity of sympathetic nervous system is involved in the pathogenesis of prostatic disease.

Background. Lysine-specific demethylase 1 (LSD1), catalysing demethylation of mono- and di-methylated histone H3-K4 or K9, exhibits diverse transcriptional activities by mediating chromatin reconfiguration. The telomerase reverse transcriptase (hTERT) gene, encoding an essential component for telomerase activity that is involved in cellular immortalization and transformation, is silent in most normal human cells while activated in up to 90% of human cancers. It remains to be defined how exactly the transcriptional activation of the hTERT gene occurs during the oncogenic process. Methodology/Principal Findings. In the present study, we determined the effect of LSD1 on hTERT transcription. In normal human fibroblasts with a tight hTERT repression, a pharmacological inhibition of LSD1 led to a weak hTERT expression, and a robust induction of hTERT mRNA was observed when LSD1 and histone deacetylases (HDACs) were both inhibited. Small interference RNA-mediated depletion of both LSD1 and CoREST, a co-repressor in HDAC-containing complexes, synergistically activated hTERT transcription. In cancer cells, inhibition of LSD1 activity or knocking-down of its expression led to significant increases in levels of hTERT mRNA and telomerase activity. Chromatin immunoprecipitation assay showed that LSD1 occupied the hTERT proximal promoter, and its depletion resulted in elevated di-methylation of histone H3-K4 accompanied by increased H3 acetylation locally in cancer cells. Moreover, during the differentiation of leukemic HL60 cells, the decreased hTERT expression was accompanied by the LSD1 recruitment to the hTERT promoter. Conclusions/Significance. LSD1 represses hTERT transcription via demethylating H3-K4 in normal and cancerous cells, and together with HDACs, participates in the establishment of a stable repression state of the hTERT gene in normal or differentiated malignant cells. The findings contribute to better understandings of hTERT/telomerase regulation, which may be implicated in the development of therapeutic strategies for telomerase dysregulation-associated human diseases including cancers.

Recent evidence has accumulated that the dynamic histone methylation mediated by histone methyltransferases and demethylases plays key roles in regulation of chromatin structure and transcription. In the present study, we show that SET and MYND domain-containing protein 3 (SMYD3), a histone methyltransferase implicated in oncogenesis, directly trans-activates the telomerase reverse transcriptase (hTERT) gene that is essential for cellular immortalization and transformation. SMYD3 occupies its binding motifs on the hTERT promoter and is required for maintenance of histone H3-K4 trimethylation, thereby contributing to inducible and constitutive hTERT expression in normal and malignant human cells. Knocking down SMYD3 in tumor cells abolished trimethylation of H3-K4, attenuated the occupancy by the trans-activators c-MYC and Sp1, and led to diminished histone H3 acetylation in the hTERT promoter region, which was coupled with down-regulation of hTERT mRNA and telomerase activity. These results suggest that SMYD3-mediated trimethylation of H3-K4 functions as a licensing element for subsequent transcription factor binding to the hTERT promoter. The present findings provide significant insights into regulatory mechanisms of hTERT/telomerase expression; moreover, identification of the hTERT gene as a direct target of SMYD3 contributes to a better understanding of SMYD3-mediated cellular transformation.

Hypoxia-inducible factor-1α (HIF-1α) has been implicated in the transcriptional regulation of the telomerase reverse transcriptase (hTERT) gene expression and telomerase activity, essential elements for cellular immortalization and transformation. However, controversial results were obtained in different studies. Moreover, it is totally unclear whether HIF-2α, the paralog of HIF-1α, plays a role in regulating hTERT expression. In the present study, we found that hypoxic treatment enhanced hTERT mRNA expression and telomerase activity in three renal cell carcinoma (RCC) cell lines with different genetic backgrounds. Both HIF-1α and HIF-2α were capable of significantly increasing the hTERT promoter activity in these cells. Moreover, depleting HIF-2α led to a down-regulation of hTERT mRNA level in RCC A498 cells expressing constitutive HIF-2α. It was found that HIF-2α bound to the hTERT proximal promoter and enhanced the recruitment of the histone acetyltransferase p300 and histone H3 acetylation locally in A498 cells treated with hypoxia. Increased levels of hTERT mRNA were observed in two of three hypoxia-treated malignant glioma cell lines. However, HIF-1α stimulated whereas HIF-2α inhibited the hTERT promoter activity in these glioma cell lines. Ectopic expression of HIF-2α resulted in diminished hTERT expression in glioma cells. Collectively, HIF-1α activates hTERT and telomerase expression in both RCC and glioma cells, and HIF-2α enhances hTERT expression in RCC cells, whereas it represses the hTERT transcription in glioma cells. These findings reveal a complex relationship between HIF-1α/2α and hTERT/telomerase expression in malignant cells, which may have both biological and clinical implications. (Mol Cancer Res 2007;5(8):793–800)

目的研究M受体亚型在正常成人前列腺各区带中的分布特征,分析不同亚型在不同区带中的基因与蛋白表达差异。方法取7例意外死亡健康成人新鲜尸体前列腺标本,免疫组织化学染色方法测定M受体亚型(M1～M3)在前列腺各区带中的分布密度,荧光定量逆转录聚合酶链反应(RT-PCR)方法测定M受体各亚型(M1～M5)在前列腺各区带中的基因表达水平。结果各M受体亚型在正常成人前列腺各区带中均有分布;M1～M3受体主要分布在腺上皮周围,中央带M3的表达腺体区(0.356±0.134)高于间质区(0.137±0.090,P<0.0001);移行带及外周带M2在腺体的表达高于间质(P<0.01)。前列腺各区带中各受体表达存在差异,中央带、移行带及前纤维肌区M2表达均高于M4(P<0.05);各受体基因水平与蛋白水平表达存在差异,基因表达最高者为M2在前纤维肌区(0.0467±0.0516),蛋白表达最高者为M2在外周带(0.290±0.148)。结论M受体及其各种亚型在正常成人前列腺各区带中有着广泛分布,在前列腺各区带中各亚型的分布密度及基因表达水平均存在差异。

Objective: To study the distribution of cholinergic muscarinic receptor subtypes(M_1～M_3) in healthy adult human prostate.Methods: Immunohistochemistry and real-time reverse transcription polymerase chain reaction techniques were used to study the distribution of cholinergic muscarinic receptor subtypes in prostate of 17 healthy adult persons.Results: The three subtypes of muscarinic receptor were all presented mainly round the epithelium and rarely in stroma by the two methods;of them,M_2 held the highest density.Conclusion: All the three subtypes of cholinergic muscarinic receptor are presented in some rule in healthy adult human prostate gland,which may contribute to the action of prostate.

X-linked inhibitor of apoptosis protein (XIAP) suppresses apoptotic cell death by binding to caspases and inhibiting their functions, while the XIAP-associated factor1 (XAF1), a zinc finger protein, antagonizes XIAP activities, thereby promoting apoptosis. The aberrant silence of the XAF1 gene has recently been found in various types of cancer cells, which is suggested to be one of the potential mechanisms underlying survival advantages of malignant cells. In the present study, we investigated the XAF1 expression in prostate cancer cells. Compared with normal tissues where a full-length of XAF1 mRNA is predominant, LNCaP and DU145 prostate cancer cell lines only expressed a short form of XAF1 transcripts, whereas PC3 cells exhibited a complete silence of the XAF1 gene. Inhibition of DNA methylation led to a switch to the full length of XAF1 mRNA expression in LNCaP and DU145 cells. The down-regulation of XAF1 expression was also observed in 6/8 tumor samples derived from patients with prostate cancer. Our findings suggest that splicing alterations or downregulation of the XAF1 transcript may occur during the development of prostate cancers due to the aberrant DNA methylation. The alternative splicing of XAF1 mRNA leads to formation of a truncated XAF1 protein with 19 amino acid deletion in its zinc finger domain, which likely affects its functional interaction with XIAP, and consequently, contributes to the pathogenesis of prostate cancers by disrupting balance of the apoptosis machinery.

BACKGROUND:The membrane-linking protein ezrin is highly expressed in several types of human cancers and correlations between its immunoreactivity and histopathological data as well as patient outcome have previously been shown. However, such studies have not yet been done on human prostate cancer. This study assesses ezrin protein expression in a series of clinical specimens. METHODS:Immunohistochemical analysis was used to characterize patterns of ezrin expression in prostatic carcinoma and benign epithelium in 103 radical prostatectomy specimens. Ezrin immunoreactivity (IR) was scored 0 to 3 (absent, weak, moderate or strong staining). Agreement between three independent observers was calculated. RESULTS:Ezrin IR in prostate cancers was moderate or strong in 70% of specimens while negative or only weakly positive in benign epithelium. Interobserver agreement of IR score was substantial (mean weighted kappa 0.70, range 0.67-0.73). Ezrin expression correlated with Gleason score (p=0.016) and seminal vesicle invasion (p=0.006) but not with extraprostatic extension or margin status. No correlation with biochemical recurrence after prostatectomy was found (p=0.19). Urothelial and squamous metaplasia invariably showed moderate or strong ezrin expression. Epithelium of seminal vesicles and ejaculatory ducts was always intensely positive. CONCLUSION:Ezrin was expressed in the majority of prostate cancers and correlated with adverse prognostic factors. Interestingly, high levels of ezrin IR were observed in benign metaplastic epithelium and in seminal vesicles.

Activation of telomerase, a key event during immortalization and malignant transformation, requires expression of the telomerase reverse transcriptase (hTERT). Consistently, lack of telomerase activity and hTERT expression occurs in most normal human somatic cells. However, it has been observed that both normal and cancerous renal tissues express hTERT whereas only the latter exhibits telomerase activity. The mechanism underlying the dissociation between hTERT expression and telomerase activity is unclear. In the present study, we examined telomerase activity and alternative splicing of hTERT transcripts in renal cell carcinoma (RCC) specimens and adjacent normal tissues from 33 patients with RCC. Telomerase activity was detectable in 27 of 33 (82%) RCC samples but none in their normal counterparts. Thirty-two of 33 tumors expressed overall hTERT mRNA and 27 of them contained full-length hTERT transcripts, all with telomerase activity. Although 42% (14 of 33) of normal renal samples expressed hTERT mRNA, none of them had full-length hTERT transcripts, coinciding with lack of telomerase activity. The presence of full-length hTERT mRNA and telomerase activity was significantly associated with c-MYC induction. In tumors, absence of full-length hTERT mRNA or telomerase activity defines a subgroup of nonmetastatic, early-stage RCCs. Taken together, telomerase repression in normal renal tissues is attributed to the absence of full-length hTERT transcripts, whereas telomerase activation is achieved via induction of or switch to expression of full-length hTERT mRNA during the oncogenic process of kidneys, and associated with aggressive RCCs.

Although human papillomavirus (HPV) has been defined as the pathogen for cervical carcinomas, molecular events underlying the oncogenic process are unclear. As telomere dysfunction-mediated chromosomal instability and telomerase activation have been suggested as key events in carcinogenesis, we dissected the dynamic changes in telomere length, checkpoint response, and temporal profile of telomerase expression during the evolution from precursor lesions (cervical intraepithelial neoplasia, CINs) to invasive cancers of the uterine cervix in sequential samples from 16 patients. Telomeres were significantly shortened in all CIN samples and no further substantial attritions occurred in most cases with the acquisition of malignant phenotype. Very short telomeres were coupled with constitutive activation of the DNA damage response pathway (Chk2 phosphorylation) and increased cellular proliferation in those cervical specimens. Telomerase reverse transcriptase (hTERT) expression was preferably induced at advanced CINs or invasive cancers. The present finding demonstrates that excessive telomere shortening predominantly occurs in the early carcinogenesis of the uterine cervix largely prior to telomerase activation. Widespread over-erosion of telomeres or telomere dysfunction in very early stages of cervical tumorigenesis might fuel transformation processes by driving chromosomal instability.

OBJECTIVES:To study the protein expression and gene copy number of ezrin in a set of high-grade prostatic intraepithelial neoplasia (HGPIN) samples with concomitant prostate cancer. Ezrin is a cytoskeleton linker protein that is actively involved in regulating the growth and metastatic capacity of cancer cells.METHODS:Nineteen HGPIN samples obtained from radical prostatectomy specimens were used for the study. Among them, 13 samples also contained invasive prostate cancer. The expression of ezrin was studied by immunohistochemistry. The same samples were also used for fluorescence in situ hybridization to study the gene copy number of ezrin.RESULTS:Immunoreactivity for ezrin was absent or weak in benign prostatic epithelial cells. Weak or moderate immunostaining was detected in 11 of 13 prostate cancer specimens. However, the immunostaining was moderate or strong in all HGPIN samples. In addition, whenever HGPIN and prostate cancer were found in the same sample, the staining was always more intense in the HGPIN cells than in the cancer cells. No alteration was found in the gene copy number detected by fluorescence in situ hybridization.CONCLUSIONS:We have shown that ezrin is overexpressed in HGPIN and prostate cancer compared with adjacent benign prostatic epithelium. In addition, HGPIN has a greater expression level of ezrin compared with that of prostate cancer. Our results indicate that aberrant expression of ezrin might be involved in the pathogenesis of prostate cancer, and ezrin expression may be useful for the diagnosis of HGPIN.

You have accessJournal of UrologyDiscussed Poster, Sunday, May 9, 2004, 8:00 am - 12:00 pm1 Apr 2004418: PIM-1 Expression in Prostatic Intraepithelial Neoplasia and Human Prostate Cancer Alexander Valdman, Xiaolei Fang, See-Tong Pang, Peter Ekman, and Lars Egevad Alexander ValdmanAlexander Valdman More articles by this author , Xiaolei FangXiaolei Fang More articles by this author , See-Tong PangSee-Tong Pang More articles by this author , Peter EkmanPeter Ekman More articles by this author , and Lars EgevadLars Egevad More articles by this author View All Author Informationhttps://doi.org/10.1016/S0022-5347(18)37680-8AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail "418: PIM-1 Expression in Prostatic Intraepithelial Neoplasia and Human Prostate Cancer." The Journal of Urology, 171(4S), p. 110 © 2016 by American Urological AssociationFiguresReferencesRelatedDetails Volume 171Issue 4SApril 2004Page: 110 Advertisement Copyright & Permissions© 2016 by American Urological AssociationMetricsAuthor Information Alexander Valdman More articles by this author Xiaolei Fang More articles by this author See-Tong Pang More articles by this author Peter Ekman More articles by this author Lars Egevad More articles by this author Expand All Advertisement PDF downloadLoading ...

PIM‐1, an oncogene product of serine/threonine kinase, has been found to play an important role in induction/suppression of apoptosis, cell cycle progression, and transcriptional regulation by phosphorylating the target proteins involved in these processes. Recently, the expression of PIM‐1 has been shown to correlate significantly with measures of prostate cancer clinical outcome.

Previous studies in hereditary and sporadic prostate cancer have indicated the existence of a tumor suppressor gene in chromosomal region 19p13. The BRG1 gene in this region is one of the possible candidates, based on both the frequency of inactivating mutations in human cancer cell lines, including the prostate cancer cell line DU145, and its functional properties. To our knowledge, no studies have been done to evaluate possible involvement of the BRG1 gene in clinical prostate cancer. To accomplish this, we carried out a complete mutation analysis of all 35 BRG1 exons in tumor and constitutional DNA samples from 21 prostate cancer patients. We report the absence of somatic mutations in the panel of samples employed, but the existence of five germline single nucleotide polymorphisms (SNPs) in CpG islands of the BRG1 gene, among them, three novel ones. In conclusion, the study excludes the presence of common BRG1 mutations in prostate cancer.