Real time reverse transcriptase polymerase chain reaction of urinary cytokeratin 20 detects transitional cell carcinoma cells. J Urol. 2001;166:2134-2141. [PMID: 11696722 DOI: 10.1016/s0022-5347(05)65521-8]

Fibroblast growth factor receptor 1 and cytokeratin 20 expressions and their relation to prognostic variables in bladder cancer

BACKGROUND

Tumor grade and stage are currently the most important prognostic variables in bladder cancer but establishing additional criteria is still needed for effective treatment.

OBJECTIVES

The aim of the study was to assess the expression of fibroblast growth factor receptor 1 (FGFR1) and cytokeratin 20 (CK20) in cancer bladder (CB) and to evaluate their association with the clinicopathological features of the disease.

PATIENTS AND METHODS

The study included 80 patients diagnosed as bladder cancer of different stages and grades and 80 patients with nonmalignant urothelial diseases of matched age and sex to the malignant group. The expressions of FGFR1 and CK20 in tissue samples were determined by RT-PCR and immunohistochemistry.

RESULTS

The expression levels of FGFR1 and CK20 were increased in the malignant group when compared to the control group (P<0.001 for each). Analysis of their expression showed that levels of FGFR1 and CK20 were significantly higher in invasive tumor stages (pT2-pT4) than in non-invasive stages (pTis, pTa, pT1) (P<0.001). Interestingly, the sensitivity and specificity of combined detection with CK20 and FGFR1 for the differentiation between invasive and non-invasive stages of bladder cancer reached 97.5% and 92.5%, respectively.

CONCLUSION

Our results determined overexpression of both FGFR1 and CK20 in CB specimens. The alterations in the expression of FGFR1 and CK20 were associated with disease stage and grade. Lastly, combined detection of FGFR1 and CK20 had a high predictive prognostic value in differentiating invasive from non-invasive carcinoma.

Diagnostic and prognostic value of bladder cancer-related transcript markers in urine

PURPOSE

Since cytology as the current "gold standard" for noninvasive detection of bladder cancer (BCa) is characterized by a relatively low sensitivity, urinary transcript levels of survivin (SVV), Ki-67 and cytokeratin 20 (CK20) were evaluated as alternative or complementary biomarkers. Furthermore, their prognostic value was investigated.

METHODS

Voided urine samples from 105 BCa patients and 156 controls were included. Total RNA was isolated from urine pellets and reverse-transcribed into cDNA. Expression levels of SVV, Ki-67 and CK20 were determined by quantitative PCR and normalized to the housekeeping gene TBP. Diagnostic performance of transcript markers and cytology was assessed by receiver operating characteristic (ROC) curve analyses. The prognostic value of the transcript markers was calculated by Cox proportional hazards models.

RESULTS

ROC analyses resulted in AUC values between 0.71 (Ki-67) and 0.86 (CK20), indicating an appropriate diagnostic power. Using specifically defined cutoff values, the expression levels of the assessed biomarkers were significantly higher in urine specimens from BCa patients compared to control group (Mann-Whitney U test p < 0.001). Specificity ranged from 75% (SVV) to 84% (CK20) and sensitivity from 56% (Ki-67) to 87% (CK20). In combination with cytology, the sensitivity increased up to 97% (CK20). With regard to prognostic power, only SVV showed a significant, but not independent impact on the risk of recurrence (p = 0.008).

CONCLUSIONS

Quantitative assessment of tumor-related transcript markers, particularly of CK20, may serve as a noninvasive method to identify patients with BCa. Moreover, SVV appears to be useful as a marker for a high risk of recurrence.

Integrated technologies in the post-genomic era for discovery of bladder cancer urinary markers

The incidence of bladder cancer (BC) continues to rise with high recurrence and mortality rate, especially in the past three decades. The development of accurate and successful BC treatment relies mainly on early diagnosis. BC is a heterogeneous disease reflected by the presence of many potential biomarkers associated with different disease phenotypes. Nowadays, cystoscopy and urinary cytology are considered the gold standard diagnostic tools for BC. There are many limitations to cystoscopy including being invasive, labor-intensive and carcinoma in situ of the bladder may easily be missed. Urinary cytology is still a noninvasive technique with high accuracy in high-grade BC with a median sensitivity of 35%. Furthermore, the need for a sensitive, specific, non invasive, easily accessible BC biomarker is a major clinical need. The field of urinary BC biomarkers discovery is still a rapidly evolving discipline in which more recent technologies are evaluated and often optimized if they are not clinically significant to the urologists. Most of the current strategies for BC urinary biomarker detection depend on integration of information gleaned from the fields of genomics, transcriptomics, proteomics, epigenetics, metabolomics and bionanotechnology. Effort is currently being made to identify the most potentially beneficial urinary biomarkers. The purpose of this review is to summarize and explore the efficacy of gathering the information revealed from the cooperation of different omic strategies that paves the way towards various urinary markers discovery for screening, diagnosis and prognosis of human BC.

Recovering circulating extracellular or cell-free RNA from bodily fluids

The presence of extracellular circulating or cell-free RNA in biological fluids is becoming a promising diagnostic tool for non invasive and cost effective cancer detection. Extracellular RNA or miRNA as biological marker could be used either for the early detection and diagnosis of the disease or as a marker of recurrence patterns and surveillance. In this review article, we refer to the origin of the circulating extracellular RNA, we summarise the data on the biological fluids (serum/plasma, saliva, urine, cerebrospinal fluid and bronchial lavage fluid) of patients suffering from various types of malignancies reported to contain a substantial amount of circulating extracellular (or cell-free) RNAs and we discuss the appropriate reagents and methodologies needed to be employed in order to obtain RNA material of high quality and integrity for the majority of the experimental methods used in RNA expression analysis. Furthermore, we discuss the advantages and disadvantages of the RT-PCR or microarray methodology which are the methods more often employed in procedures of extracellular RNA analysis.

Regulation of androgen receptor transactivity and mTOR-S6 kinase pathway by Rheb in prostate cancer cell proliferation

BACKGROUND

Ras homolog-enriched in brain (Rheb), a small GTP-binding protein, is associated with prostate carcinogenesis through activating mammalian target of rapamycin (mTOR) signaling pathway. This study aimed to elucidate whether Rheb promotes proliferation of prostate cancer cells and can act as a potent therapeutic target in prostate cancer.

METHODS

Prostate cancer cell lines and human prostatic tissues were examined for the expression of Rheb. The effects of forced expression or knockdown of Rheb on cell proliferation were also examined. Semi-quantitative and quantitative RT-PCR were performed to evaluate mRNA expression. Western blotting was used to examine protein expression. Cell count and WST-1 assay were used to measure cell proliferation. Fluorescence-activated cell sorting was used to assess the cell cycle.

RESULTS

Rheb mRNA and protein expression was higher in more aggressive, androgen-independent prostate cancer cell lines PC3, DU145, and C4-2, compared with the less aggressive LNCaP. Rheb expression was higher in cancer tissues than in benign prostatic epithelia. Forced expression of Rheb in LNCaP cells accelerated proliferation without enhancing androgen receptor transactivity. Attenuation of Rheb expression or treatment with the mTOR inhibitor rapamycin decreased proliferation of PC3 and DU145 cells, with a decrease in the activated form of p70S6 kinase, one of the main targets of mTOR.

CONCLUSIONS

Rheb potentiates proliferation of prostate cancer cells and inhibition of Rheb or mTOR can lead to suppressed proliferation of aggressive prostate cancer cell lines in vitro. Rheb and the mTOR pathway are therefore probable targets for suppressing prostate cancer.

Restoration of cyclin D2 has an inhibitory potential on the proliferation of LNCaP cells

Despite well known oncogenic function of G1-S cell-cycle progression, cyclin D2 (CCND2) is often silenced epigenetically in prostate cancers. Here we show that CCND2 has an inhibitory potential on the proliferation of androgen receptor (AR)-dependent prostate cancer LNCaP cells. Forced expression of CCND2 suppressed the proliferative ability and induced cell death in LNCaP cells in a cdk-independent manner. Knocking down CCND2 restored the proliferation of LNCaP subclones with relatively high CCND2 expression and low proliferative profiles. Immunoprecipitation using deletion mutants of CCND2 indicated that a central domain of CCND2 is required for binding to AR. A deletion mutant lacking the central domain failed to hinder LNCaP cells. Collectively, our results indicated that CCND2 inhibits cell proliferation of AR-dependent prostate cancer through the interaction with AR. Our study suggests that restoration of CCND2 expression potentially prevents the carcinogenesis of prostate cancer, which is mostly AR-dependent in the initial settings.

Purine-rich element binding protein (PUR) alpha induces endoplasmic reticulum stress response, and cell differentiation pathways in prostate cancer cells

BACKGROUND

Following androgen ablation treatment for advanced prostate cancer, almost all men relapse after a period of initial response to therapy, which eventually is life threatening. We have previously found that purine-rich element binding protein, PURalpha, was significantly repressed in androgen-independent prostate cancer cell lines in comparison to an androgen-dependent line. Moreover, over-expressing PURalpha in androgen-independent prostate cancer cells attenuated their cell proliferation. The aim of the studies described here was to uncover some of the mechanisms by which over-expression of PURalpha attenuates cell proliferation.

METHODS

A set of common genes induced by over-expressing PURalpha both in PC3 and LNCaP cells was analyzed by DNA microarray. The results were then validated utilizing quantitative reverse transcription-PCR. Using a 5.3-kb region of the PSA promoter containing androgen response elements, the participation of PURalpha in androgen regulated gene expression was determined.

RESULTS

Genes involved in stress response and cell differentiation were induced in cells over-expressing PURalpha. Some of the genes that are targets of androgen regulation are also induced. Most strikingly, ectopic expression of PURalpha induced transcriptional activity of the 5.3-kb PSA promoter containing androgen response elements, without androgen stimulation.

CONCLUSION

Based upon the consideration that some of the genes involved in cell stress and differentiation are also regulated by androgens our data suggest that PURalpha shares some common pathways regulated by the androgen receptor. These findings suggest that regulation of PURalpha expression in prostate cancer cells may serve as a therapeutic target for hormone refractory prostate cancer.

The potential role of purine-rich element binding protein (PUR) alpha as a novel treatment target for hormone-refractory prostate cancer

BACKGROUND

Hormonal therapy for advanced prostate cancer is typically effective at first, but almost all men suffer refractory disease which often is life threatening. The nuclear matrix comprises not only of the structural elements of the nucleus, but is associated with many components of the molecular machinery. Our aim is to find novel targets for the treatment of hormone-refractory prostate cancer (HRPC) by focusing on the composition of the nuclear matrix proteins (NMPs).

METHODS

LN96 cells were established at our Institution after long-term culturing of LNCaP cells under androgen deprived conditions. The composition of NMPs of LNCaP cells and LN96 cells were analyzed by two-dimensional (2D) electrophoresis and spots differentially expressed were investigated by mass spectrometry for identification. Among the spots identified, we analyzed the potential functional role of the identified proteins in prostate cancer cells by establishing stable overexpressed cells.

RESULTS

We found that purine-rich element binding protein (PUR)alpha was significantly repressed not only in NMPs but also in total protein and mRNA levels of LN96 cells in comparison to LNCaP cells under the same steroid deprived conditions. Moreover, PURalpha was decreased in its expression both at the protein and mRNA levels in the androgen-independent prostate cancer cell lines, PC3 and DU145 in comparison to LNCaP cells. Stably overexpressing PURalpha in PC3 and DU145 cells negatively regulates cell proliferation, resulting in decreases in PCNA expression.

CONCLUSION

Further dissection of the role of PURalpha in cell growth regulation may reveal a novel target for HRPC.

Sensitizing effect of galectin-7 in urothelial cancer to cisplatin through the accumulation of intracellular reactive oxygen species

To improve chemotherapeutic efficacy in urothelial cancer, it is important to identify predictive markers for chemosensitivity as well as possible molecules accelerating cell killing mechanisms. In this study, we assessed the possibility of galectin-7 to accelerate cis-diamminedichloroplatinum (CDDP)-induced cell killing in vitro and also to predict chemosensitivity against CDDP in urothelial cancer patients. The expression of galectin-7 was analyzed in five bladder cancer cell lines with different p53 status after treatment with CDDP. The roles of galectin-7 in chemosensitivity against CDDP were analyzed by transfection of the galectin-7 gene into several of these cell lines. Furthermore, the relationship between the expression of galectin-7 and the response to neoadjuvant chemotherapy was analyzed in 17 human bladder cancer specimens. Exposure to CDDP induced galectin-7 in cell lines with wild-type p53 but not in those with mutated p53. When the galectin-7 gene was transfected into cell lines with mutated p53, the sensitivity to CDDP increased compared with control transfectants. In addition, galectin-7-transfected cells exhibited more accumulation of intracellular reactive oxygen species and activation of c-Jun NH(2)-terminal kinase (JNK) and Bax than control transfectants. SP600125, an inhibitor of JNK, or antioxidant N-acetyl-L-cysteine inhibited the enhancement of chemosensitivity against CDDP by galectin-7 transfection. In clinical samples, the expression levels of galectin-7 were significantly lower in urothelial carcinomas compared with normal urothelium. When chemosensitivity was tested, its expression levels were higher in the chemosensitive group than in the chemoresistant group. Galectin-7 is a candidate for a predictive marker of chemosensitivity against CDDP, and the targeted expression of galectin-7 might overcome the chemoresistance of urothelial cancer.

Detection of newly diagnosed bladder cancer, bladder cancer recurrence and bladder cancer in patients with hematuria using quantitative rt-PCR of urinary survivin

BACKGROUND/AIMS

Survivin mRNA in urine was measured to detect newly diagnosed bladder cancer, bladder cancer recurrence and bladder cancer in patients with hematuria.

METHODS

We have investigated urinary survivin mRNA of 118 voided urine specimens, including 24 patients with bladder cancer, 50 with bladder cancer history, 68 not known to harbor bladder cancer, and 55 with hematuria using quantitative reverse transcriptase polymerase chain reaction. beta-Actin mRNA expression was also examined and used as an endogenous control to ensure validity of the assay for each sample.

RESULTS

The survivin expression in urological patient urine had sensitivities and specificities for all patients of 79 and 93%, for detection of newly diagnosed bladder cancer 83 and 95%, for bladder cancer recurrence 82 and 90%, and for bladder cancer in patients with hematuria 80 and 90%.

CONCLUSION

Our results indicate that quantitative reverse transcriptase polymerase chain reaction of urinary survivin is a sensitive, noninvasive and highly specific assay to detect both newly diagnosed bladder cancer and bladder cancer recurrence. Furthermore, this assay may be useful in stratifying the hematuria population in urological practice.

Urinary cytokeratin 20 mRNA expression has the potential to predict recurrence in superficial transitional cell carcinoma of the bladder

Higher levels of cytokeratin 20 (CK 20) mRNA are expressed in malignant urothelial tissue compared to normal tissue. We determined the CK 20 mRNA expression in urine from patients with transitional cell carcinoma (TCC) of the bladder and assessed the biological behavior of such tumors in a 5-year follow-up. Second voided urine was preoperatively collected from 56 patients with bladder carcinoma, from 20 patients with nonmalignant urological diseases and from 40 healthy volunteers. RNA extraction from exfoliated urothelial cells was followed by quantitative real-time RT-PCR with the Light Cycler. Patients in the superficial TCC group had a median expression of 8226AU (arbitrary units) with and 1523AU without tumor recurrence (P=0.023). No such correlation was detected in the group with muscle-invasive tumors. Kaplan-Meier analysis revealed a significant difference between recurrent and nonrecurrent disease (P=0.019) in superficial but not in muscle-invasive TCC (P=0.84). CK 20 mRNA expression in urine has the potential to identify patients at risk for recurrence of noninvasive papillary urothelial tumors. It helps to categorize patients prior to TUR-B, so that the cystoscopy interval during follow-up may be extended in those with low-risk superficial TCC.

Real-time quantitative analysis for human telomerase reverse transcriptase mRNA and human telomerase RNA component mRNA expressions as markers for clinicopathologic parameters in urinary bladder cancer

AIM

The expression of the telomerase subunits such as human telomerase reverse transcriptase (hTERT) and human telomerase RNA component (hTR) may be associated with tumor development and progression. We evaluated the relationship between mRNA quantification of both hTERT and hTR and clinicopathologic parameters in bladder cancer.

METHODS

We examined the mRNA expression of hTERT and hTR in 29 specimens with bladder cancer (Grade: Grade I, 9 cases; Grade II, 13 cases and Grade III, 7 cases. Stage: pTa-pT1, 18 cases; pT2-T4, 11 cases). We immediately froze all of specimens obtained during TUR-Bt and isolated the total RNA from each specimen. We measured the quantity of hTERT, hTR and GAPDH mRNA by a real-time reverse transcription-polymerase chain reaction method based on TaqMan technology.

RESULTS

The hTERT/GAPDH mRNA ratio and hTERT mRNA/total RNA in superficial bladder tumor was significantly lower than in invasive bladder tumor. The hTR/GAPDH mRNA ratio and hTR mRNA/total RNA in superficial tumor were significantly lower than in invasive bladder tumor. The hTERT mRNA expression significantly correlated with tumor grade, but the hTR mRNA expression did not correlate with tumor grade. There was no significant difference in the hTERT/GAPDH mRNA ratio and hTR mRNA/total RNA according to multiplicity of bladder tumor.

CONCLUSIONS

Our results demonstrated that the expression of hTERT mRNA correlated with the progression of stage and grade in bladder cancer. The quantitative analysis of hTERT and hTR mRNA might be a marker for clinicopathologic parameters in bladder cancer.

Requirement of androgen-dependent activation of protein kinase Czeta for androgen-dependent cell proliferation in LNCaP Cells and its roles in transition to androgen-independent cells

A cell line that we designed, AILNCaP, proliferated in androgen-depleted medium after emerging from long-term androgen-depleted cultures of an androgen-sensitive prostate cancer cell line, LNCaP. Using this cell line as a model of progression to androgen independence, we demonstrated that the activity of the mammalian target of rapamycin/p70 S6 kinase transduction pathway is down-regulated after androgen depletion in LNCaP, whereas its activation is related to transition of this cell line to androgen-independent proliferation. Kinase activity of protein kinase Czeta is regulated by androgen stimulation in LNCaP cells, whereas it is activated constitutively in AILNCaP cells under androgen-depleted conditions. Treatment with a protein kinase Czeta pseudosubstrate inhibitor reduced p70 S6 kinase activity and cell proliferation in both cell lines. We identified that both protein kinase Czeta and p70 S6 kinase were associated in LNCaP cells and this association was enhanced by the androgen stimulation. We examined the expression of phospho-protein kinase Czeta and phospho-p70 S6 kinase in hormone-naive prostate cancer specimens and found that the expression of both kinases was correlated with each other in those specimens. Significant correlation was observed between the expression of both kinases and Ki67 expression. Most of the prostate cancer cells that survived after prior hormonal treatment also expressed both kinases. This is the first report that shows the significance of this pathway for both androgen-dependent and -independent cell proliferation in prostate cancer. Our data suggest that protein kinase Czeta/mammalian target of rapamycin/S6 kinase pathway plays an important role for the transition of androgen-dependent to androgen-independent prostate cancer cells.

Molecular markers in bladder cancer: A critical appraisal

The diagnosis of both primary and recurrent bladder tumors currently relies upon the urine cytology and cystoscopy. Neither of these diagnostic tools is completely accurate. Prognostication of bladder cancer is largely based on pathologic tumor grade and stage. Over the past 2 decades, there is accumulating evidence that like many other cancers, bladder cancer, too, has a distinct molecular signature that separates it from other cancers and normal bladder tissue. Bladder tumors of different grades and stages even possess unique, and specific genotypic and phenotypic characteristics. Although recognition of several of these molecular alterations is possible by analyzing tumor tissue, urine, and serum samples, few if any of these "molecular markers" for bladder cancer are widely used in clinical practice. These markers include some that can be applied during the diagnostic work-up of symptoms (e.g., hematuria), those under surveillance for recurrence of superficial disease and forecasting long-term prognosis, or response to chemotherapy. In this review of molecular markers for bladder cancer, effectiveness of markers in each of these categories that are identifiable in the urine of patients with bladder cancer was examined. Many of the diagnostic markers appear to hold an advantage over urine cytology in terms of sensitivity, especially for the detection of low-grade superficial tumors. However, most markers tend to be less specific than cytology, yielding more false-positives. This result is more commonly observed in patients with concurrent bladder inflammation or other benign bladder conditions. Although there are several candidate markers for assessing prognosis or response to chemotherapy, studies of large patient populations are lacking. Further studies involving larger numbers of patients are required to determine their accuracy and widespread applicability in guiding treatment of bladder cancer.

Cytokeratin-20 immunocytology in voided urine exhibits greater sensitivity and reliability than standard cytology in the diagnosis of transitional cell carcinoma of the bladder

OBJECTIVES

To investigate whether immunocytochemical detection of cytokeratin (CK)-20 could serve as a reliable diagnostic marker for transitional cell carcinoma (TCC) of the bladder.

METHODS

A total of 232 patients were enrolled in the study. Group 1 consisted of 144 patients with histologically confirmed TCC (62 at diagnosis and 82 in follow-up), and group 2 consisted of 88 subjects, including healthy volunteers and individuals with "non-TCC" conditions. Spontaneously voided urine specimens were obtained from each patient and submitted to immunocytologic and standard cytologic examination.

RESULTS

CK-20 immunocytology yielded an overall sensitivity of 65.3%, significantly greater than the sensitivity of urine cytology (54.2%, P = 0.013). A more detailed analysis revealed a sensitivity advantage for the former technique in the detection of primary (61.3% versus 51.6%, P = 0.046), recurrent (68.3% versus 56.1%, P = 0.027), Stage pT1 (81.8% versus 59.1%, P = 0.006), grade 2 (76.2% versus 61.9%, P = 0.031), and grade 3 (82.1% versus 67.9%, P = 0.039) tumors. Moreover, CK-20 immunocytochemistry demonstrated greater overall specificity than cytology (90.9% versus 86.4%, respectively), a difference stemming from the subgroup of lithiasis patients (100% versus 66.7%, P = 0.024). In terms of reliability, the positive and negative predictive values of the immunoassay were greater than those calculated for cytology (92.2% versus 86.7% and 61.5% versus 53.5%, respectively).

CONCLUSIONS

CK-20 immunocytology is more sensitive than standard cytology in the detection of TCC, particularly of Stage pT1, grade 2, and grade 3 tumors. In view of its high overall specificity and predictive accuracy, it is conceivable that the proposed immunoassay may progressively replace conventional cytologic screening in the diagnosis of bladder cancer.

Quantitative detection of cytokeratin 20 mRNA expression in bladder carcinoma by real-time reverse transcriptase-polymerase chain reaction

OBJECTIVES

To determine cytokeratin 20 (CK 20) expression in tumor tissue, normal urothelial tissue, bladder washings, and urine from patients with urothelial carcinoma by real-time reverse transcriptase-polymerase chain reaction using the LightCycler Instrument.

METHODS

Urine, bladder washings, tumor, and normal urothelial tissue were obtained from 33 patients with bladder carcinoma. RNA was subsequently extracted. Twenty tissue samples from healthy volunteers were used as controls. Real-time reverse transcriptase-polymerase chain reaction with the LightCycler was performed using fluorescence-labeled CK 20 primers as the target gene and the porphobilinogen deaminase housekeeping gene as the internal standard.

RESULTS

CK 20 mRNA expression was detected in all samples investigated. CK 20 expression in the tissue and urine samples from patients with tumor was significantly increased compared with that in normal urothelial tissue (P = 0.028) or urine from the negative control group (P = 0.012). The average CK 20 expression was 70,140 arbitrary units (AU) in tumor tissue (30,533 AU in urine from patients with tumor) and 8460 AU in normal urothelial tissue (2234 AU in normal urine). A stage-related difference in CK 20 mRNA expression was observed in tumor tissue (P = 0.027) and for tumor grade G1-G2 versus G3 (P = 0.03).

CONCLUSIONS

CK 20 mRNA expression levels in tissue and urine were elevated in patients with urothelial carcinoma compared with the levels in healthy individuals. CK 20 expression was also detectable in normal urine or normal urothelial tissue, but at significantly lower levels than in tumor samples. Fluorescence-labeled quantitative polymerase chain reaction using the LightCycler helped to differentiate between low-level CK 20 expression in normal urothelial tissue and the levels in tumor tissue samples. CK 20 might be an excellent and sensitive marker for tumor monitoring and routine follow-up in patients with transitional cell carcinoma.

VALUE OF REVERSE TRANSCRIPTION POLYMERASE CHAIN ASSAY IN PERIPHERAL BLOOD OF PATIENTS WITH UROTHELIAL CANCER

PURPOSE

The nested reverse transcription polymerase chain reaction (RT-PCR) method was used to determine expression of uroplakin II (UP II) or cytokeratin 20 (CK-20) in cells separated from the peripheral blood of patients with urothelial cancer. We examine whether UP II or CK-20 expression can be used as a urothelial cancer marker for urothelial cancer in cells isolated from peripheral blood.

MATERIALS AND METHODS

Peripheral blood was taken from 20 healthy volunteers without a history of urothelial cancer, from 10 patients with a negative bladder biopsy for urothelial cancer and from 108 patients with urothelial cancer. Results of a nested RT-PCR assay were compared with pathological stage and recurrence.

RESULTS

None of the peripheral blood samples from the control subjects revealed a positive polymerase chain reaction result. Among 108 patients with transitional cell carcinoma of the bladder nested RT-PCR for UP II was positive in 25 (23%) versus 31 (29%) for CK-20 (p >0.05). Nested RT-PCR for UP II was positive in 5 (8%) patients with superficial stage disease (pTa and pT1) versus 8 (11%) positive for CK-20. Nested RT-PCR for UP II was positive in 15 (58%) patients with a stage of pT2 or advanced stages versus 17 (65%) positive for CK-20. Nested RT-PCR for UP II was positive in 13 (20%) and 10 (56%) patients with grades 2 and 3, respectively, versus 17 (27%) and 12 (67%) nested RT-PCR positive for CK-20. A significant difference in the Kaplan-Meier recurrence-free actuarial curve was noted among patients with superficial stage who were positive and negative on nested RT-PCR for UP II and CK-20 in peripheral blood, respectively, but not in the invasive stage. On multivariate analysis nested RT-PCR for UP II and CK-20 in peripheral blood were independent prognostic factors in patients with superficial stage disease but not with invasive stage disease. Lung and/or liver metastasis developed in 5 (80%) of 6 patients whose results after chemotherapy (consisting of cisplatin, doxorubicin hydrochloride, vinblastine sulfate and methotrexate) for nested RT-PCR for UP II and CK-20 remained positive.

CONCLUSIONS

These results seem to indicate that UP II and CK-20 mRNA in the blood may be useful tumor markers for predicting patient survival and the extent of urothelial cancer.

Application of real-time reverse transcriptase-polymerase chain reaction in urological oncology

PURPOSE

During the last decade numerous different reverse transcriptase-polymerase chain reaction (RT-PCR) techniques have been described. However, the lack of highly sensitive, quantitative and reliable methodology has been responsible for its limited use in modern urology. Early semiquantitative RT-PCR techniques often proved not to produce consistent results and have a high failure rate due to complicated working models. In this article we provide a comprehensive and intelligible description of real-time PCR technology, which is a novel quantitative methodology to analyze gene expression. In addition, we report the first preclinical and clinical applications in molecular urology.

MATERIALS AND METHODS

The current literature was reviewed in regard to different current real-time RT-PCR protocols and their use in modern urological oncology.

RESULTS

Real-time RT-PCR is a reliable, rapid and relatively inexpensive technique that can be easily adapted for standardized preclinical and clinical applications at different centers. Its sensitivity equals at least that of conventional RT-PCR and the option of exact quantification of gene expressions allows proper differentiation among high, low and illegitimate RNA transcription. It eliminates post-PCR processing of PCR products, thereby, increasing throughput and decreasing the chance of carryover contamination.

CONCLUSIONS

Although the application of real-time RT-PCR has gained wide acceptance in urological research, its routine clinical use is still in its infancy. However, due to its high sensitivity and exact quantitation real-time RT-PCR may be the method of choice for modern preclinical and clinical studies in the future.