Biomedical subjects

Hans Krause

Publications and source records attributed to Hans Krause.

At least 19 recordsLinked to original sources

PubMed2007

Expression parameters of the inhibitors of apoptosis cIAP1 and cIAP2 in renal cell carcinomas and their prognostic relevance.

The expression of the inhibitor of apoptosis (IAP) family members cIAP1 and cIAP2 have been shown to be altered in various cancer entities. This study was done to characterize the tumor-related expression profile of cIAP1 and cIAP2 in patients with renal cell carcinomas (RCC) and to evaluate its potential predictive value after curative resection. Expression of cIAP1 and cIAP2 was analyzed by real-time RT-PCR in RCC and corresponding normal tissue samples obtained from a cohort of 127 RCC patients (median follow-up: 48 months) undergoing surgical treatment. Expression data was correlated to histopathological variables and outcome. Overexpression of cIAP1 and cIAP2 occurred in most RCC specimens (p < 0.001), but 20% of the patients had lower cIAP levels in malignant than in normal tissue. The cIAP1 expression correlated with the tumor stage, levels being higher in pT1 tumors than in advanced pathological stages (p = 0.002). Decreased cIAP1 expression in RCC relative to paired normal samples predicted an abbreviated time to recurrence (hazard rate 2.96; 95% CI: 1.23-7.09) and tumor-specific survival (hazard rate 2.78; 95% CI: 1.22-6.38) irrespective of the tumor stage and grade. The prognostic effect of cIAP1 was most pronounced in patients with pT3 disease (log rank test p = 0.001). The results of uni- and multivariate analysis suggest a prognostic value of cIAP1 expression for RCC patients, downregulation indicating an aggressive, potentially lethal phenotype.

Adult↗

PubMed2007

Lymphocytes upregulate signal sequence-encoding proopiomelanocortin mRNA and beta-endorphin during painful inflammation in vivo.

Proopiomelanocortin (POMC)-derived beta-endorphin1-31 (END) released from immune cells inhibits inflammatory pain. We examined the expression of END and POMC mRNA encoding the signal sequence required for entry of the nascent polypeptide into the regulated secretory pathway in lymphocytes of rats with inflamed hindpaws. Within 12 h of inflammation, END increased in popliteal lymph nodes and at 96 h the intraplantar neutralization of END exacerbated pain. Lymphocytes expressed POMC, END, and full-length POMC mRNA. Semi-nested PCR revealed 8-fold increased exon 2-3 spanning POMC mRNA. Thus, painful inflammation enhances signal sequence-encoding lymphocytic POMC mRNA needed for regulated secretion of functionally active END.

Animals↗

PubMed2006

A gene expression profile of tumor suppressor genes commonly methylated in bladder cancer.

PURPOSE: The functional relationship between promoter hypermethylation and gene inactivation has been demonstrated for few genes only. We examined the promoter methylation status of two important tumor suppressor genes APAF-1 and DAPK-1 in bladder cancer as well as the mRNA expression pattern of these two genes for possible correlation between promoter hypermethylation and transcriptional repression. METHODS: The methylation status and mRNA expression levels were related to clinicopathological features in 34 patients with transitional cell carcinoma (TCC) of the bladder with a median clinical follow-up of more than 45 months. Tissue from ten patients with nonmalignant disease served as a control group. Quantitative real-time PCR-based detection methods were used for determination of the normalized index of methylation (NIM) as well as the mRNA expression level. RESULTS: APAF-1 and DAPK-1 methylation and mRNA expression was observed in all tumor and normal control samples investigated. Methylation (NIM) levels were significantly higher in tumor tissue for APAF-1 and DAPK-1, but median mRNA expression levels did not differ significantly comparing tumorous and non tumorous tissue. No correlation between expression levels of APAF-1 and DAPK-1 mRNA and tumor stage or grade was observed. However, in superficial TCC a strong correlation between higher NIM levels and lower mRNA expression of the APAF-1 gene was observed (P = 0.014). CONCLUSIONS: Our results, although preliminary, provide first time in vivo expression analysis of the APAF-1 gene in bladder cancer specimen, suggesting expression control by promoter methylation in early stage tumor disease of the bladder.

Aged↗

PubMed2006

Kinetic fluorescence reverse transcriptase-polymerase chain reaction for alpha-methylacyl CoA racemase distinguishes prostate cancer from benign lesions.

BACKGROUND: High-throughput gene expression profiling has recently shown that the mRNA for alpha-methylacyl CoA racemase (AMACR or P504S) is overexpressed in prostate carcinomas (PCa). Several immunohistochemical studies have reported the usefulness of anti-AMACR/P504S for detecting prostate cancer over the full range of prostate specimens encountered in surgical pathology. We tested real-time reverse transcriptase-polymerase chain reaction (RT-PCR) for specific and sensitive detection of AMACR transcripts as a supplementary measure for discriminating between malignant and benign lesions in prostatic tissues. METHODS: Total RNA was isolated from snap-frozen chips in 55 cases of benign prostatic hyperplasia (BPH) and from frozen sections in 57 prostatectomy cases. The latter were analyzed by an uropathologist (J.K.) and found to contain at least 50% malignant epithelia. Relative quantification of AMACR transcripts was performed by RT-PCR using hybridization probes for detection and PBGD for normalization. RESULTS: Normalized AMACR transcript levels showed an average 3.75-fold increase in 57 prostate carcinomas cases when compared to 55 cases of BPH (p<0.0001). A 85.6% specificity and 64.9% sensitivity can be achieved if the cutoff is set at 12.95. AMACR expression levels among PCa cases were not statistically associated with the tumor and lymph node stage, the grading, the surgical margins, the Gleason score or progression. DISCUSSION: The present study demonstrates the usefulness of quantitative AMACR-mRNA transcript detection in prostatic tissues as an alternative to immunological staining techniques. Since the latter clearly predominate in the laboratory routine, PCR-based detection of AMACR has the potential to gain widespread acceptance as a suitable future tool for monitoring prostate cancer patients.

Adenocarcinoma↗

PubMed2006

Regularly methylated novel pro-apoptotic genes associated with recurrence in transitional cell carcinoma of the bladder.

Epigenetic silencing of tumor suppressor genes by promoter hypermethylation has been shown for a variety of genes in bladder cancer. Various p53 target genes have been investigated, but only few demonstrated promoter hypermethylation when semiquantitative detection methods were applied. To address to the question whether promoter methylation of novel p53 effector genes is a common event in transitional cell carcinoma of the bladder, we selected the p53 target genes apoptotic protein-activating factor (APAF-1), Caspase 8 (CASP-8), death-associated protein kinase, (DAPK-1) and insulin-like growth-factor-binding protein-3 (IGFBP-3), performing quantitative methylation-specific real-time PCR. The individual level of methylation (normalized index of methylation) was correlated with clinicopathological features as well as the biological behavior of the superficial and muscleinvasive tumors. Tissue was obtained from 110 tumor patients and 20 patients without urological malignancy. The median follow-up of the tumor patients was 52 months. Hypermethylation of the promoter region in tumor specimens was common for APAF-1 (100%), DAPK-1 (74%) and IGFBP-3 (66%), but not for CASP-8 (3.6%). It was seen less frequently and with undetectable or low methylation levels in the normal urothelium group. The APAF-1 methylation levels significantly correlated with tumor stage and tumor grade. The APAF-1 and IGFBP-3 methylation levels were able to separate tumors with higher recurrence risk from low-risk tumors in nonmuscleinvasive and muscleinvasive tumors. In multivariate analysis, APAF-1 and IGFBP-3 methylation levels were independent prognostic markers for recurrence in superficial bladder tumors. This study provides new insights into the role of promoter methylation of selected p53 target genes. The extent of promoter methylation of specific genes offers additional prognostical information and is associated with the outcome in patients with nonmuscleinvasive and muscleinvasive bladder cancer.

Adult↗

PubMed2006

Promoter hypermethylation profile of kidney cancer with new proapoptotic p53 target genes and clinical implications.

PURPOSE: Risk stratification of renal cell carcinoma is based on the histopathologic classification. Promoter hypermethylation as a mechanism of gene inactivation in renal cell carcinoma has been shown for only a small number of genes. We examined the usefulness of quantitative methylation analysis with a new set of p53 target genes for determining the clinical outcome and aggressiveness of the tumor disease. EXPERIMENTAL DESIGN: The genes selected were APAF-1, CASPASE-8, DAPK-1, IGFBP-3, and PML. The tissue samples analyzed were taken from tumor specimens obtained from 90 consecutive patients with clear cell renal carcinoma and from 20 normal kidney specimens. Quantitative methylation analysis of CpG sites in the promoter region was done by methylation-specific real-time PCR and the normalized index of methylation (NIM) was determined for each sample. RESULTS: Hypermethylation of the promoter region was common for APAF-1 (97%) and DAPK-1 (41%) but not for IGFBP-3 (3%), PML (3%), or CASP-8 (0%). The tumor patients had a median follow-up of 55 months. A correlation was found between the methylation level of APAF-1 and tumor size and nodal status, but not for tumor stage, grade, and age of patient. Kaplan-Meier analysis was able to identify patients with a higher risk of recurrence and tumor-related death by using APAF-1 (>or=56% NIM) and DAPK-1 (>or=10% NIM) methylation levels. In multivariate analysis, APAF-1 and DAPK-1 methylation levels were independent prognostic markers for metastatic disease and death from renal cell carcinoma. CONCLUSIONS: Our findings indicate that promoter hypermethylation of APAF-1 and DAPK-1 is a marker of aggressive renal cell carcinoma and provides independent prognostic information on disease outcome.

Apoptosis Regulatory Proteins↗

PubMed2006

Impact of hormonal therapy on the detection of promoter hypermethylation of the detoxifying glutathione-S-transferase P1 gene (GSTP1) in prostate cancer.

BACKGROUND: In spite of excellent cure rates for prostate cancer patients with favorable tumor characteristics, patients with unfavorable characteristics after radical prostatectomy are still at a significantly increased risk of tumor progression. Early adjuvant hormonal therapy (AHT) has been shown to be of prognostic benefit in these patients. Unfortunately initiation and duration of early AHT in the individual patient is based on statistic data. PSA, as the standard prostate marker is neither able to reliably indicate minimal residual tumor disease in the early postoperative phase, nor can it be used for therapy monitoring due to the suppressive effect of hormonal therapy on PSA production. Promoter hypermethylation of the detoxifying glutathione-S-transferase P1 gene (GSTP1-HM) has been shown to be the most common DNA alteration of primary prostatic carcinoma which, when used as a marker, is supposed to be able to overcome some of the disadvantages of PSA. However until now information on the impact of hormonal therapy on the detection of GSTP1-HM is lacking. The purpose of our study was to assess the impact of endocrine therapy on the detection of GSTP1-HM by methylation-specific PCR (MSP) in prostate cancer. METHODS: Paraffin embedded tumor samples from the radical prostatectomy (RP) specimens from 15 patients after hormonal therapy (HT) (mean 8 months) were assessed by MSP. In 8 of the patients the GSTP-1 status of the tumors before HT was assessed on the corresponding initial diagnostic biopsies. RESULTS: Following HT MSP showed GSTP1-HM in 13/15 of the RP specimens. In two patients analysis of the RP specimens failed to show GSTP1-HM. All initial tumor samples (8/8 biopsy specimens) showed GSTP1-HM, including both patients negative for GSTP1 HM in the corresponding RP specimen. CONCLUSION: In most cases hormonal therapy appears to not alter GSTP1 HM detection. However the change from a positive to a negative GSTP1 HM status in a subset of the patients may point to an, at least partial androgen dependency. Further studies on a larger cohort of patients are necessary to assess its frequency and the exact hormonal interactions.

Adenocarcinoma↗

PubMed2006

Epigenetic silencing of the putative tumor suppressor gene testisin in testicular germ cell tumors.

PURPOSE: Testisin, a serine protease abundantly expressed only in normal testes, is thought to be a tumor suppressor gene silenced by aberrant methylation in testicular germ cell tumors (TGCT). This study aimed at identifying the CpG sites relevant for testisin gene silencing when methylated and evaluating the potential of aberrant methylation as a biomarker in TGCT. METHODS: Bisulfite sequencing and subsequent real-time RT-PCR were carried out in germ cell tumor cell lines and a cervical carcinoma cell line to reveal CpG sites implicated in testisin gene silencing. The normalized index of methylation (NIM) and the relative gene expression (RGE) were calculated in 33 TGCT and 19 normal testicular tissue samples by quantitative methylation-specific PCR (QMSP) and real-time RT-PCR. RESULTS: CpG sites in the 5'untranslated region proved to be relevant for testisin gene silencing when methylated. Targeting these CpG sites by QMSP, we demonstrated that the median NIM was 8.6 times higher in the TGCT group than in normal testicular samples. This was associated with a median 23.6 times lower RGE in the TGCT probes. Non-seminomas had a significantly higher NIM than seminomas, but RGE was downregulated to comparable levels in both subgroups. QMSP was highly sensitive and distinguished TGCT from normal samples with excellent specificity. CONCLUSIONS: Our results demonstrate for the first time that aberrant methylation of specific CpG sites near the transcription initiation site is an important factor in testisin gene silencing in TGCT.

5' Untranslated Regions↗

PubMed2006

Testicular expression of survivin and human telomerase reverse transcriptase (hTERT) associated with spermatogenic function in infertile patients.

AIM: To characterize the coexpression of survivin, an inhibitor of apoptosis (IAF), and human telomerase reverse transcriptase (hTERT) in human testes with varying spermatogenic function. METHODS: Transcript levels of survivin mRNA and hTERT mRNA were determined in normal testes (n=11) and testes with defective spermatogenesis (n=28) using real-time reverse-transcription polymerase chain reaction (RT-PCR). The histological work-up was performed according to a modified Johnsen score. RESULTS: Expressions of both survivin and hTERT were highest at median levels of 96.8 and 709 in normal spermatogenesis and dropped to 53.3 and 534 in testes with postmeiotic spermatogenic arrest (n=10). In severe spermatogenic failure (n=18), survivin expression was lacking in most specimens (n=16), whereas at least low levels of testicular hTERT expression were largely detectable with a normalized expression of 73 in premeiotic spermatogenic arrest (n=7) and 45 in patients with Sertoli cell-only syndrome (SCOS) (n=3). Both survivin and hTERT expressions increased with a progressing Johnsen score (P for trend=0.001). CONCLUSION: Although both survivin and hTERT are correlated with spermatogenic function, they show different expression patterns in testes of infertile patients. These findings substantiate results from studies in the rodent testis suggesting a predominant expression of survivin in meiotically dividing germ cells.

Biopsy↗

PubMed2005

Quantitative evaluation of telomerase subunits in urine as biomarkers for noninvasive detection of bladder cancer.

The aim of our study was to prospectively evaluate the potential diagnostic value and clinical applicability of quantitative analysis of telomerase subunits gene expression in urine for noninvasive detection of bladder cancer. Expression levels of human telomerase reverse transcriptase (hTERT) and human telomerase RNA (hTR) were analyzed by real-time reverse transcriptase polymerase chain reaction (RT-PCR) in urine samples from 163 subjects with bladder cancer and 237 controls (163 individuals with benign genitourinary diseases; 74 healthy subjects). The sensitivity, specificity and optimal cutoffs were determined and compared to the corresponding values obtained by voided urine cytology. Quantitative urinary hTR analysis detects bladder cancer with an overall sensitivity of 77.0%, whereas hTERT analysis reached a sensitivity of 55.2%. The majority of undetected tumors were small, low-grade pTa lesions. Both hTR and hTERT proved to be significantly more sensitive than cytology (34.5%; p < 0.001). Specificities for hTR, hTERT and cytology were 72.1%, 85.0% and 92.7%, respectively, in the total study population and 96.9%, 89.2% and 100%, respectively, in healthy subjects. Higher diagnostic accuracy was achieved by hTR than by hTERT analysis (p < 0.05). The specificity of hTR increased to 85.0% in the total population if urinary leukocyte contamination was excluded. These data suggest that quantitative hTR analysis is the most accurate telomerase-based test for bladder cancer detection and has the potential to replace cytology as a noninvasive biomarker for disease diagnosis and follow-up.

Biomarkers, Tumor↗

PubMed2005

Quantitative analysis of survivin mRNA expression in urine and tumor tissue of bladder cancer patients and its potential relevance for disease detection and prognosis.

Suppression of apoptosis may favor the onset and progression of cancer. Survivin is an inhibitor of apoptosis that has been suggested as a novel diagnostic/prognostic marker of bladder cancer. In this study, survivin mRNA expression was measured by a sensitive real-time PCR assay in tumor tissue and urine from bladder cancer patients and assessed for its potential diagnostic and prognostic relevance. Specimens from 53 patients with bladder transitional cell carcinoma (TCC) were analyzed, the controls being normal urothelial tissues (n = 14) and urine from benign disease patients (n = 22) and healthy individuals (n = 14). Survivin transcripts were commonly detected in tumor tissues, but not in normal urothelium, and increasing mRNA levels correlate with progressing pathologic stage (p = 0.001) and grade categories (p < 0.004). Higher levels of expression were associated with a reduced time to recurrence in noninvasive TCCs (p = 0.027, log-rank test) and a trend toward shorter disease-free survival in muscle-invasive tumors (p = 0.067). Urinary survivin analysis detects TCC with higher sensitivity (68.6%) and equal specificity (100%) when compared with cytology (31.4% and 97.1%). Our results indicate that tissue levels of survivin mRNA predict disease-free survival in noninvasive TCC and may have a role in bladder cancer progression. When analyzed by RT-PCR in urine, survivin is a highly specific biomarker for TCC detection.

Aged↗

PubMed2005

Expression levels of the inhibitor of apoptosis survivin in testes of patients with normal spermatogenesis and spermatogenic failure.

OBJECTIVE: To determine the expression of the inhibitor of apoptosis survivin in men with and without spermatogenic failure. DESIGN: Prospective case study. SETTING: Two university-based infertility clinics. PATIENT(S): Forty-nine infertile men presenting with azoospermia. INTERVENTION(S): Testicular biopsies for histopathological assessment and analyses of survivin expression levels by real-time reverse transcription-polymerase chain reaction. Survivin levels were normalized to expression of the housekeeping porphobilinogen deaminase gene. MAIN OUTCOME MEASURE(S): Correlation of the histological findings with normalized survivin expression levels. RESULTS(S): Testicular survivin mRNA expression was highest in normal spermatogenesis (n = 14). Decreased expression was observed in patients with spermatogenesis disorders. The expression level correlated with the degree of spermatogenic failure. While it was reduced in postmeiotic maturation arrest (n = 11), a lack of expression was seen in most specimens (10 of 12) with premeiotic maturation arrest and in all of those with Sertoli cell-only syndrome (n = 12). CONCLUSION(S): These data indicate that survivin is expressed in human germ cells and might be involved in apoptosis control during spermatogenesis. Decreased survivin expression in spermatogenic disorders may contribute to the accelerated germ cell apoptosis observed in male idiopathic infertility.

Atrophy↗

PubMed2005

Quantification of survivin mRNA in testes of infertile patients and in testicular germ cell tumours: high levels of expression associated with normal spermatogenesis.

Deregulated apoptosis of germ cells may contribute to male infertility as well as malignant transformation. Survivin, an inhibitor of apoptosis (IAP), is overexpressed in all the most common human malignancies, but barely detectable in normal tissues. We used real-time polymerase chain reaction (PCR) to quantify survivin mRNA expression in normal testes (n = 22), testes with defective spermatogenesis (n = 26) and testicular germ cell tumours (TGCTs; n = 16). Survivin was expressed at high levels in normal testes. Testicular survivin levels in infertile patients were related inversely to the severity of spermatogenic failure (p < 0.001), with a lack of expression in most specimens with pre-meiotic spermatogenic arrest and in all those with germ cell aplasia. Lower levels of expression were observed in TGCTs than in normal testes. While survivin expression was detected in most TGCTs with undifferentiated components (12 of 13), it was absent in all mature teratomas (n = 3). These data show that survivin is expressed in normal and transformed germ cells. Its downregulation in spermatogenic disorders indicates that survivin may contribute to the normal balance between germ cell proliferation and apoptosis. In TGCTs, survivin expression appears to be lost with somatic differentiation.

Gene Expression Profiling↗

PubMed2005

Expression levels of the EZH2 polycomb transcriptional repressor correlate with aggressiveness and invasive potential of bladder carcinomas.

The polycomb group protein enhancer of zeste 2 (EZH2) is a transcriptional repressor involved in the control of cellular proliferation and oncogenesis. The aim of the present study was to quantify EZH2 expression in bladder carcinomas and to correlate the data with clinicopathological findings. EZH2 mRNA expression was measured by real-time reverse transcription-polymerase chain reaction in tumor tissue specimens obtained from 37 patients with urothelial carcinomas of the bladder and in four bladder cancer cell lines. EZH2 levels were normalized to expression of the housekeeping porphobilinogen deaminase gene. EZH2 transcripts were commonly detected in tumor tissue. Transcript levels correlated significantly with the invasiveness of bladder tumors (p = 0.029) with elevated EZH2 mRNA expression measured in invasive bladder carcinomas (median value, 38.92) compared with non-invasive tumors (15.51). In addition, levels of expression were significantly higher in high-grade (G3) than in low-grade (G1/2) lesions (p < 0.001). EZH2 mRNA levels in bladder carcinoma cell lines were within the range of high-grade invasive bladder cancers. In conclusion, expression levels of EZH2 are elevated in aggressive and invasive urothelial carcinomas, suggesting that deregulated EZH2 expression may be involved in the progression of bladder tumors.

Aged↗

PubMed2004

The inhibitor of apoptosis (IAP) survivin is expressed in human testicular germ cell tumors and normal testes.

Deregulated apoptosis of germ cells may contribute to malignant transformation as well as male infertility. We analyzed expression of the inhibitor of apoptosis survivin by polymerase chain reaction (PCR) in testicular germ cell tumors (TGCTs, n=28), normal testes (n=19) and testes with defective spermatogenesis (n=22). In a subset of samples (n=35), survivin transcript levels were quantified using real-time PCR. While survivin mRNA was expressed at high levels in undifferentiated TGCTs and normal testes, it was lost in mature teratomas and germ cell aplasia. Survivin expression in both normal and transformed germ cells is in contrast to its sharp differential expression in other tissues. Survivin expression correlates with the differentiation state of TGCTs and may be relevant for their tumorigenesis and malignant potential.

Cell Transformation, Neoplastic↗

PubMed2004

Expression of the apoptosis inhibitor survivin in testicular tissue of infertile patients.

Summary Apoptosis is a common phenomenon during spermatogenesis, and its dysregulation has been associated with male infertility. Survivin is an inhibitor of apoptosis protein that regulates apoptosis at cell division and is overexpressed in common human cancers. We investigated whether survivin mRNA expression is detectable in testicular biopsies from patients with infertility of varying aetiology. The aim of this study was to examine the testicular survivin expression in azoospermic men with normal spermatogenesis and in those with specific spermatogenic disorders. Survivin mRNA expression was detected by reverse transcriptase-polymerase chain reaction in histologically classified testicular biopsy specimens from 30 azoospermic men. Survivin was found to be expressed in normal spermatogenesis (n = 10), in post-meiotic spermatogenic arrest (n = 6), and in specimens showing a mixed picture of pre-meiotic maturation arrest with sparse islands of post-meiotic arrest (n = 2). In contrast, a lack of survivin expression was seen in specimens without haploid germ cells (pre-meiotic maturation arrest, n = 2) and in those with Sertoli-cell-only syndrome (SCOS, n = 10). These data indicate for the first time that survivin is expressed in human testis. Moreover, its expression seems to correlate with the stage of maturation arrest in patients presenting with spermatogenic disorders. Survivin mRNA expression was not found in SCOS specimens, possibly indicating germ-cell-specific expression in human testicular tissue. Thus, survivin is a potential molecular marker of spermatogenesis, whose expression is altered in specific spermatogenic disorders.

Apoptosis↗

PubMed2003

Mast cells express novel functional IL-15 receptor alpha isoforms.

Mast cells previously have been reported to be regulated by IL-15 and to express a distinct IL-15R, termed IL-15RX. To further examine IL-15 binding and signaling in mast cells, we have studied the nature of the IL-15R and some of its biological activities in these cells. In this study, we report the existence of three novel isoforms of the IL-15R alpha chain in murine bone marrow-derived mast cells as a result of an alternative exon-splicing mechanism within the IL-15R alpha gene. These correspond to new mRNA transcripts lacking exon 4; exons 3 and 4; or exons 3, 4, and 5 (IL-15R alpha Delta 4, IL-15R alpha Delta 3,4, IL-15R alpha Delta 3,4,5). After transient transfection in COS-7 cells, all IL-15R alpha isoforms associate with the Golgi apparatus, the endoplasmic reticulum, the perinuclear space, and the cell membrane. Analysis of glycosylation pattern demonstrates the usage of a single N-glycosylation site, while no O-glycosylation is observed. Importantly, IL-15 binds with high affinity to, and promotes the survival of, murine BA/F3 cells stably transfected with the IL-15R alpha isoforms. Furthermore, we report that signaling mediated by IL-15 binding to the newly identified IL-15R alpha isoforms involves the phosphorylation of STAT3, STAT5, STAT6, Janus kinase 2, and Syk kinase. Taken together, our data indicate that murine mast cells express novel, fully functional IL-15R alpha isoforms, which can explain the selective regulatory effects of IL-15 on these cells.

Alternative Splicing↗

PubMed2003

Real-time quantitative reverse transcriptase-polymerase chain reaction for luteinizing hormone-releasing hormone receptor gene mRNA expression in human prostate cancer.

OBJECTIVES: To determine quantitative real-time reverse transcriptase-polymerase chain reaction (RT-PCR) detection of luteinizing hormone-releasing hormone (LHRH) receptor mRNA expressing prostate cancer (CaP) and benign prostatic hyperplasia (BPH) tissue by sequence-specific detection with hybridization probes using the LightCycler. Various in vitro studies have indicated that LHRH agonists and antagonists may have a direct inhibitory effect on CaP mediated by specific LHRH receptors. The incidence of LHRH receptor mRNA expression was demonstrated in 50% to 100% of clinical CaP and BPH tissue by current RT-PCR methods. However, qualitative RT-PCR can only demonstrate the existence of a gene; an exact quantification of LHRH-receptor mRNA expression has not yet been done. METHODS: Quantitative real-time RT-PCR for LHRH receptor mRNA was performed using the LightCycler system and the RNA Amplification Kit hybridization probes in 35 patients with CaP and 38 patients with BPH. RESULTS: Thirty-one (88.6%) of the 35 patients with CaP and 36 (94.7%) of the 38 patients with BPH had positive RT-PCR for LHRH receptor mRNA. The number of positive amplifications per 1 microg total RNA was not significantly lower in CaP at 695,428 +/- 350,860 than in BPH at 1,617,654 +/- 787,874. Patients with CaP evidenced a significant negative correlation between the amplification rate for LHRH receptor mRNA and Gleason score (r = -0.476; P = 0.004). CONCLUSIONS: In the past, the potential mechanisms acting on LHRH receptors in CaP have been identified as possible antitumor strategies for this type of cancer. Our study is the first to show that CaP does not have a higher expression of LHRH receptor mRNA expression than BPH when using quantitative sequence-specific oligonucleotide hybridization probes that only detect certain PCR products.

Adenocarcinoma↗