Value of clusterin immunoreactivity as a predictive factor in muscle-invasive urothelial bladder carcinoma

Diagnostic performance of clusterin in hepatocellular carcinoma: A meta-analysis

Introduction

Clusterin (CLU) is a pleiotropic protein with numerous functions. It has recently attracted considerable attention owing to its association with cancer progression and metastasis. However, its role in hepatocellular carcinoma (HCC) has not been investigated. This meta-analysis is the first evaluation of the diagnostic performance of CLU in HCC.

Methods

Articles published in PubMed, EMBASE, Web of Science, Wanfang Data Knowledge Service Platform, and China Science and Technology Journal Database until January 2022 were searched. Studies that reported the usefulness of CLU for the differentiation of HCC and non-HCC (e.g., liver cirrhosis, chronic hepatitis, and other benign liver disease) patients were selected. Alpha-fetoprotein (AFP) was used as a positive control in this study. The sensitivity, specificity, diagnostic odds ratio (DOR), and area under the curve (AUC) were compared between CLU and AFP.

Results

Eight articles including 811 participants were included. The pooled sensitivity (95% confidence interval (CI)), specificity (95% CI), DOR (95% CI), and AUC (95% CI) were: 0.86 (0.78–0.91), 0.85 (0.75–0.91), 35 (13–94), and 0.92 (0.89–0.94) for CLU; 0.74 (0.67–0.81), 0.89 (0.79–0.94), 22 (8–61), and 0.87 (0.84–0.90) for AFP; 0.93 (0.88–0.96), 0.85 (0.68–0.94), 75 (21–262), and 0.95 (0.92–0.96) for CLU + AFP, respectively. Compared with AFP, CLU showed higher sensitivity, DOR, and AUC, as well as similar specificity. The combination of CLU and AFP resulted in higher sensitivity, DOR, and AUC.

Conclusions

Serum CLU is a better biomarker versus AFP for the diagnosis of HCC. The combination of CLU and AFP improved diagnostic performance.

sCLU as prognostic biomarker and therapeutic target in osteosarcoma

Osteosarcoma (OS) is the most common primary malignant bone tumor. Secretory apolipoprotein J/clusterin (sCLU) is overexpressed in many cancers; however, its role in OS has not been previously investigated. The objectives of this study were to address this question and also to assess the clinical value of sCLU as a prognostic biomarker and therapeutic target by comparing sCLU expression in human OS (n = 106), normal bone (n = 16), fibrous dysplasia (n = 9), and ossifying myositis (n = 11) tissues and by evaluating the effect of sCLU silencing on OS growth, invasion, and chemosensitivity in vitro and in vivo. We found that sCLU was highly expressed in OS tissue specimens, which was positively correlated with metastatic disease and negatively correlated with response to chemotherapy. sCLU knockdown in KHOS cells inhibited proliferation and invasion and increased apoptosis as well as sensitivity to the chemotherapy drug gemcitabine (Gem). In a mouse xenograft model, sCLU depletion suppressed lung metastasis and enhanced the effects of Gem, thereby slowing KHOS tumor growth. These results indicate that sCLU overexpression is a biomarker for malignant transformation of OS and that therapeutic strategies targeting sCLU may be an effective treatment for OS.

Highlights

● Secretory apolipoprotein J/clusterin (sCLU) is overexpressed in osteosarcoma (OS).

● sCLU overexpression is associated with metastasis and chemoresistance.

● Silencing sCLU inhibits metastasis and enhances chemosensitivity in OS cells.

sCLU is a biomarker for metastatic OS and a potential therapeutic target.

Meta-analysis of efficacy and safety of custirsen in patients with metastatic castration-resistant prostate cancer

Custirsen is the second-generation antisense oligonucleotide (ASO), which can reduce cellular levels of clusterin to increase the cytotoxic effect of chemotherapeutic drugs. Our study assessed the efficacy and safety of custirsen in patients with metastatic castration-resistant prostate cancer (mCRPC).We conducted a comprehensive search to identify all the randomized controlled trials (RCTs) of custirsen for the treatment of mCRPC. The reference lists of the retrieved studies were investigated.Three publications involving a total of 1709 patients were used in the analysis. We found that overall survival (OS) (P = .25) was not statistically significant in the comparison. Safety assessments indicated custirsen were often associated with complications resulting from neutropenia (P < .001), anaemia (P < .001), thrombocytopenia (P < .001), and diarrhea (P = .002).Our meta-analysis shows that custirsen has no obvious effect on improving the OS of patients with mCRPC. Adverse reactions were more common among those patients treated with custirsen as compared to those treated with placebo.

Clusterin inhibition mediates sensitivity to chemotherapy and radiotherapy in human cancer

Since its discovery in 1983, the protein clusterin (CLU) has been isolated from almost all human tissues and fluids and linked to the development of different physiopathological processes, including carcinogenesis and tumor progression. During the last few years, several studies have shown the cytoprotective role of secretory CLU in tumor cells, inhibiting their apoptosis and enhancing their resistance to conventional treatments including hormone depletion, chemotherapy, and radiotherapy. In an effort to determine the therapeutic potential that the inhibition of this protein could have on the development of new strategies for cancer treatment, numerous studies have been carried out in this field, with results, in most cases, satisfactory but sometimes contradictory. In this document, we summarize for the first time the current knowledge of the effects that CLU inhibition has on sensitizing tumor cells to conventional cancer treatments and discuss its importance in the development of new strategies against cancer.

Custirsen in combination with docetaxel and prednisone for patients with metastatic castration-resistant prostate cancer (SYNERGY trial): a phase 3, multicentre, open-label, randomised trial

BACKGROUND

Clusterin is a chaperone protein associated with treatment resistance and upregulated by apoptotic stressors such as chemotherapy. Custirsen is a second-generation antisense oligonucleotide that inhibits clusterin production. The aim of the SYNERGY trial was to investigate the effect of custirsen in combination with docetaxel and prednisone on overall survival in patients with metastatic castration-resistant prostate cancer.

METHODS

SYNERGY was a phase 3, multicentre, open-label, randomised trial set at 134 study centres in 12 countries. Patients were eligible for participation if they had: metastatic castration-resistant prostate cancer and had received no previous chemotherapy; prostate-specific antigen greater than 5 ng/mL; and a Karnofsky performance score of 70% or higher. Patients were randomly assigned 1:1 centrally to either the docetaxel, prednisone, and custirsen combination or docetaxel and prednisone alone. Patients were not masked to treatment allocation. Randomisation was stratified by opioid use for cancer-related pain and radiographic evidence of progression. All patients received docetaxel 75 mg/m² intravenously with 5 mg of prednisone orally twice daily. Patients assigned docetaxel, prednisone, and custirsen received weekly doses of custirsen 640 mg intravenously after three loading doses of 640 mg. The primary endpoint was overall survival analysed in the intention-to-treat population. Patients who received at least one study dose were included in the safety analysis set. This trial is registered with ClinicalTrials.gov, number NCT01188187. The trial is completed and final analyses are reported here.

FINDINGS

Between Dec 10, 2010, and Nov 7, 2012, 1022 patients were enrolled to the trial, of whom 510 were assigned docetaxel, prednisone, and custirsen and 512 were allocated docetaxel and prednisone. No difference in overall survival was recorded between the two groups (median survival 23·4 months [95% CI 20·9-24·8] with docetaxel, prednisone, and custirsen vs 22·0 months [19·5-24·0] with docetaxel and prednisone; hazard ratio [HR] 0·93, 95% CI 0·79-1·10; p=0·415). The most common adverse events of grade 3 or worse in the docetaxel, prednisone and custirsen group (n=501) compared with the docetaxel and prednisone alone group (n=499) were neutropenia (grade 3, 63 [13%] vs 28 [6%]; grade 4, 98 [20%] vs 77 [15%]), febrile neutropenia (grade 3, 52 [10%] vs 31 [6%]; grade 4, four [1%] vs two [<1%]), and fatigue (grade 3, 53 [11%] vs 41 [8%]; grade 4, three [1%] vs one [<1%]). One or more serious adverse events were reported for 214 (43%) of 501 patients treated with docetaxel, prednisone, and custirsen and 181 (36%) of 499 receiving docetaxel and prednisone alone. Adverse events were attributable to 23 (5%) deaths in the docetaxel, prednisone, and custirsen group and 24 (5%) deaths in the docetaxel and prednisone alone group.

INTERPRETATION

Addition of custirsen to first-line docetaxel and prednisone was reasonably well tolerated, but overall survival was not significantly longer for patients with metastatic castration-resistant prostate cancer treated with this combination, compared with patients treated with docetaxel and prednisone alone.

FUNDING

OncoGenex Technologies.

Prognostic Role of Secretory Clusterin in Multiple Human Malignant Neoplasms: A Meta-Analysis of 26 Immunohistochemistry Studies

Secretory clusterin (sCLU) is a potential prognostic tumour biomarker, but results of different sCLU studies are inconsistent. We conducted this meta-analysis to evaluate the precise predictive value of sCLU. Qualified studies were identified by performing online searches in PubMed, EMBASE, and Web of Science. The selected articles were divided into three groups based on scoring method for clusterin detection. Pooled hazard ratios (HRs) with 95% confidence interval (CI) for patient survival and disease recurrence were calculated to determine the correlation between sCLU expression and cancer prognosis. Heterogeneity was assessed using I2 statistics, and specific heterogeneity in different groups was analysed. Elevated sCLU was significantly associated with recurrence-free survival in groups 1 and 3 (group 1: pooled HR = 1.35, 95% CI = 1.01 to 1.79; group 3: pooled HR = 1.80, 95% CI = 1.22 to 2.65). However, clusterin expression was not associated with overall survival in all three groups. Results showed that only the heterogeneity of group 2 was very strong (p = 0.013, I2 = 76.3%), in which the specimens were scored through sCLU staining intensity only. sCLU is a potential biomarker for tumour prognosis, and IHC methods can be more standardised if both intensity and staining proportion are considered.

High Ki-67 Immunohistochemical Reactivity Correlates With Poor Prognosis in Bladder Carcinoma: A Comprehensive Meta-Analysis with 13,053 Patients Involved

Ki-67 is considered as one of prime biomarkers to reflect cell proliferation and immunohistochemical Ki-67 staining has been widely applied in clinical pathology. To solve the widespread controversy whether Ki-67 reactivity significantly predicts clinical prognosis of bladder carcinoma (BC), we performed a comprehensive meta-analysis by combining results from different literature. A comprehensive search was conducted in the Chinese databases of WanFang, China National Knowledge Infrastructure and Chinese VIP as well as English databases of PubMed, ISI web of science, EMBASE, Science Direct, and Wiley online library. Independent studies linking Ki-67 to cancer-specific survival (CSS), disease-free survival (DFS), overall survival (OS), progression-free survival (PFS), and recurrence-free survival (RFS) were included in our meta-analysis. With the cut-off values literature provided, hazard ratio (HR) values between the survival distributions were extracted and later combined with STATA 12.0. In total, 76 studies (n = 13,053 patients) were eligible for the meta-analysis. It was indicated in either univariate or multivariate analysis for survival that high Ki-67 reactivity significantly predicted poor prognosis. In the univariate analysis, the combined HR for CSS, DFS, OS, PFS, and RFS were 2.588 (95% confidence interval [CI]: 1.623-4.127, P < 0.001), 2.697 (95%CI: 1.874-3.883, P < 0.001), 2.649 (95%CI: 1.632-4.300, P < 0.001), 3.506 (95%CI: 2.231-5.508, P < 0.001), and 1.792 (95%CI: 1.409-2.279, P < 0.001), respectively. The pooled HR of multivariate analysis for CSS, DFS, OS, PFS, and RFS were 1.868 (95%CI: 1.343-2.597, P < 0.001), 2.626 (95%CI: 2.089-3.301, P < 0.001), 1.104 (95%CI: 1.008-1.209, P = 0.032), 1.518 (95%CI: 1.299-1.773, P < 0.001), and 1.294 (95%CI: 1.203-1.392, P < 0.001), respectively. Subgroup analysis of univariate analysis by origin showed that Ki-67 reactivity significantly correlated with all 5 clinical outcome in Asian and European-American patients (P < 0.05). For multivariate analysis, however, the pooled results were only significant for DFS, OS, and RFS in Asian patients, for CSS, DFS, PFS, and RFS in European-American patients (P < 0.05). In the subgroup with low cut-off value (<20%), our meta-analysis indicated that high Ki-67 reactivity was significantly correlated with worsened CSS, DFS, OS, PFS, and RFS on univariate analysis (P < 0.05). For multivariate analysis, the meta-analysis of literature with low cut-off value (<20%) demonstrated that high Ki-67 reactivity predicted shorter DFS, PFS, and RFS in BC patients (P < 0.05). In the subgroup analysis of high cut-off value (≥20%), our meta-analysis indicated that high Ki-67 reactivity, in either univariate or multivariate analysis, significantly correlated with all five clinical outcomes in BC patients (P < 0.05). The meta-analysis indicates that high Ki-67 reactivity significantly correlates with deteriorated clinical outcomes in BC patients and that Ki-67 can be considered as an independent indicator for the prognosis by the meta-analyses of multivariate analysis.

Diagnostic evaluation of urinary angiogenin (ANG) and clusterin (CLU) as biomarker for bladder cancer

Bladder carcinoma is an important worldwide health problem. Both cystoscopy and urine cytology used in detecting bladder cancer suffer from drawbacks where cystoscopy is an invasive method and urine cytology shows low sensitivity in low grade tumors. This study validates easier and less time-consuming techniques to evaluate the value of combined use of angiogenin and clusterin in comparison and combination with voided urine cytology in the detection of bladder cancer patients. This study includes malignant (bladder cancer patients, n = 50), benign (n = 20) and healthy (n = 20) groups. The studied groups were subjected to cystoscopic examination, detection of bilharzial antibodies, urine cytology, and estimation of urinary angiogenin and clusterin by ELISA. The overall sensitivity and specificity were 66 and 75 % for angiogenin, 70 and 82.5 % for clusterin and 46 and 80 % for voided urine cytology. Combined sensitivity of voided urine cytology with the two studied biomarkers was 88 % which is higher than the combined sensitivity of both markers alone (82 %) and that of the cytology with each marker (76 and 80 %) for angiogenin and clusterin respectively. In conclusion, combined use of the cytology with the studied biomarkers can improve the sensitivity for detecting bladder cancer, and may be very useful in monitoring the effectiveness of antiangiogenic and apoptotic therapies in bladder cancer.

Clinical Significance of ErbB Receptor Family in Urothelial Carcinoma of the Bladder: A Systematic Review and Meta-Analysis

The prognostic importance of examining ErbB receptor family expression in human bladder cancer remains uncertain. Using published evidence, we examined the clinical value and the updated results of clinical trials targeting ErbB receptor family members. Twenty-seven articles from 65 references related to ErbB receptor expression assessment in bladder cancer were reviewed. The estimates included the association significance, hazard ratios, and 95% confidence intervals (CIs) from actuarial curves and survival analyses. A meta-analysis was done on those reports using univariate log-rank tests or a Cox-regression model. The methods of analysis and study subjects chosen varied widely among studies. The overall risks of disease progression for patients with EGFR or ErbB2 overexpression were 4.5 (95% CI: 2.5–8.4) and 1.1 (95% CI: 0.6–1.9), and the risks of mortality were 3.0 (95% CI: 1.6–5.9) and 1.1 (95% CI: 1.0–1.2), respectively. However, the significance of coexpression patterns of the ErbB receptor family remains controversial. None of six clinical trials yielded convincing results for blockading ErbB receptor signaling in urothelial carcinoma. The results of this analysis suggest that assessing co-expression patterns of the ErbB family may provide better prognostic information for bladder cancer patients.

Prognostic value of apoptotic activity in muscle-invasive bladder cancer

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Clusterin immunoreactivity as a predictive factor for progression of non-muscle-invasive bladder carcinoma

INTRODUCTION

There is a need for prognostic markers which can predict the subset of patients who will not respond sufficiently to conservative management in non-muscle-invasive bladder carcinoma. We analyzed the association of clusterin (CLU) with clinicopathological factors.

MATERIALS AND METHODS

Immunohistochemical CLU expression was investigated in paraffin-embedded archival tissues of initial transurethral resection specimens of 46 patients with non-muscle-invasive bladder carcinoma. The result was expressed as the proportion of the number of CLU-containing tumor cells to the total number of tumor cells detected in each slide and 'percent CLU expression' was calculated for each patient.

RESULTS

Of the 46 cases (35 male, 11 female), 18 were ≥ 65 years of age. CLU expression was significantly higher in male and elderly patients. Following the initial transurethral resection, 39 patients showed tumor recurrence, and progression was seen in 25 patients, of whom 17 progressed to muscle invasion during follow-up. Although there was no significant correlation between CLU expression and recurrence, significant correlation with overall progression and progression to muscle-invasive disease was observed in this cohort of patients (p = 0.001 and p = 0.014, respectively). Among the patients with progression to muscle invasion, 13 underwent radical cystectomy with pT2 tumor in 5 patients in the final pathology of surgical specimens and pT3 and higher in the remainder.

CONCLUSIONS

CLU immunoreactivity showed correlation with age, gender and progression, mainly progression to muscle invasion. Thus, CLU can be used as a molecular marker to predict the potential of progression to muscle-invasive disease in a particular tumor which in turn may prove useful in the decision-making process for early cystectomy without losing time with conservative management.

Clusterin immunoexpression and its clinical significance in patients with non-small cell lung cancer

Clusterin is an enigmatic glycoprotein with a nearly ubiquitous tissue distribution. It plays important roles in various pathophysiological processes, including tissue remodeling, reproduction, lipid transport, complement regulation, and apoptosis. Clusterin appears to have two main isoforms that result from alternative splicing. The secreted and nuclear forms of clusterin have been reported to play different roles in human malignancies. The purpose of this study was to examine clusterin immunoexpression and its clinical significance in a group of Chinese patients with non-small cell lung cancer (NSCLC). Tissue samples from the primary tumors of 121 patients with completely resected NSCLC were obtained. Clusterin protein expression was evaluated by immunohistochemical staining with an antibody against all clusterin isoforms. Staining patterns were observed and graded based on intensity and density and were correlated with clinical and pathological data. Both cytoplasmic and nuclear clusterin immunostaining patterns were observed. Clusterin staining was observed only in the cytoplasm in 70 patients (57.9%), only in the nucleus in 27 patients (22.3%), and in both the cytoplasm and nucleus in 16 patients (13.2%). A significant association was observed between positive cytoplasmic clusterin expression and histologic type as indicated by adenocarcinomas that were more likely to have clusterin staining only in the cytoplasm. Clusterin immunostaining was neither associated with recurrence-free survival (RFS) nor overall survival of patients by univariate or multivariate analysis. For patients undergoing chemotherapy, those with only cytoplasmic clusterin staining had worse survival than other patients. In conclusion, both cytoplasmic and nuclear immunostaining patterns of clusterin were detected in the tumors of patients with NSCLC. Adenocarcinomas were more likely to have only cytoplasmic staining. The immunoexpression of clusterin was not associated with prognosis, and cytoplasm-only immunostaining of clusterin was inversely correlated with chemosensitivity in this group of patients.

Clusterin expression is associated with decreased disease-free survival of patients with colorectal carcinomas

AIMS

It has been demonstrated that increased clusterin expression is involved in malignant progression and that anticlusterin treatment leads to selective apoptosis. The aim of this study was to determine the clinicopathological significance of clusterin expression in human colorectal carcinomas.

METHODS AND RESULTS

The expression of clusterin was examined in 31 adenomas and 103 colorectal carcinomas. Normal epithelial cells were always negative for clusterin expression, but clusterin expression was present in 16% (5/31) of adenomas and this percentage increased in colorectal carcinomas (30%, 31/103). Immunopositivity always presented an apical cytoplasmic pattern. The expression level of clusterin did not correlate with age, gender, grade or stage. However, its expression was significantly associated with a decrease in disease-free survival (P < 0.05). In a multivariate Cox proportional hazards model, clusterin expression remained a significant independent predictor.

CONCLUSIONS

Clusterin expression may have a role in colonic carcinogenesis and may help identify patients with more aggressive tumours who may benefit from targeted therapy.

The role of clusterin (CLU) in malignant transformation and drug resistance in breast carcinomas

Breast cancer is the main cause of cancer-related death among women in Western countries. Current research is focused on identifying antiapoptotic proteins which could be a possible target for novel chemotherapeutic drugs. Secretory clusterin (sCLU) is an extracellular chaperone that has been functionally implicated in DNA repair, cell-cycle regulation, apoptotic cell death and tumorigenesis. The implication of sCLU in carcinogenesis and the progression of breast carcinomas make it an interesting gene, worthy of investigation. It has been reported to present powerful antiapoptotic activity and to perform a prosurvival function with most therapeutic treatments for breast cancer. This review summarizes our current understanding of the role of CLU in tumorigenesis, progression, and response to treatment in breast carcinomas.

Clusterin as a predictor for chemoradiotherapy sensitivity and patient survival in esophageal squamous cell carcinoma

Clusterin (CLU) is frequently overexpressed and correlates closely with chemotherapy and radiotherapy resistance and poor prognosis in many human cancers. However, the significance of CLU expression in chemoradiotherapy (CRT) sensitivity and its effect on the prognosis of esophageal squamous cell carcinoma (ESCC) are still unknown. In the present study, we used the methods of immunohistochemistry and terminal deoxyuridine triphosphate nick-end labeling assay to examine the expression status of CLU and apoptotic index in 110 pretreated biopsy specimens of ESCC patients treated with definitive CRT. High expression of CLU was observed in 42.7% of epithelium and 50.0% of stroma in ESCC. A significant association of high CLU stromal expression with large tumor size (P = 0.012) and locoregional progression (P = 0.001) was observed, and high epithelial expression of CLU showed a significant correlation with the lack of complete response (P = 0.028) and low apoptotic index (P = 0.001). Univariate analysis revealed that high CLU stromal expression was associated with poor locoregional progression-free survival, distant progression-free survival, and overall survival. Furthermore, ESCC patients with high CLU expression in both epithelium and stroma have the shortest survival time among the subgroups of different CLU expression status. In multivariate analysis, CLU stromal expression was evaluated as an independent prognostic factor for locoregional progression-free survival, distant progression-free survival, and overall survival. These findings suggest an important role for CLU, especially in stroma, in ESCC progression, and that high CLU epithelial expression might be a promising predictor of ESCC resistance to CRT.

Changes in clusterin serum concentration levels in oncologic patients during the course of spa therapy--a pilot study

BACKGROUND

Clusterin (70-80 kDa; synonym ApoJ) is a stress-associated cytoprotective glycoprotein involved in many physiological and pathophysiological processes and it is up-regulated by various apoptotic triggers in many cancers and neurodegenerative diseases.

AIM

Measurement of serum clusterin values in individuals with a history of cancer before and after spa therapy.

METHODS

Serum clusterin concentration (ELISA) was determined in a group of 26 oncologic patients (4 men and 22 women) at the beginning and at the end (the 18th or 19th day) of spa treatment. The spa treatment lasted 3 weeks. The patients with various types of cancer had undergone basic therapy (surgery, chemotherapy, actinotherapy) prior to spa treatment. They were divided according to the interval between the end of basic treatment and the start of spa therapy. Patients coming within 12 months comprised group A (n=15) while patients coming later comprised group B (n=11).

RESULTS

clusterin concentrations increased in 11 patients (73%) and decreased in 4 (27%) in group A and increased in 5 (45%) and decreased in 6 (55%) in group B. The non-parametric sign test was non-significant. There were positive value of average change between the second and the first sample in group A and negative value in group B. In group A the parametric test showed significant increased clusterin concentration at the end of spa treatment but the data had non-parametric distribution in fact.

CONCLUSION

It is concluded that early spa therapy increases clusterin serum concentration. This is probably due to to the positive effects of balneotherapy. However the sample was very small and further research is required.

Clusterin as a diagnostic and prognostic marker for transitional cell carcinoma of the bladder

We investigated the feasibility of profiling and measuring the concentration of clusterin in urine and serum for individuals with transitional cell carcinoma (TCC) of the bladder and comparing it with nontumor controls. In addition, we analyzed the correlation of expression of clusterin in specimens of TCC to various clinicopathologic parameters and prognosis of bladder cancer. Blood and urine samples were used from 68 patients with TCC of the bladder and from 61 patients with benign urological diseases. Enzyme-linked immunosorbent assays (ELISA) were performed for clusterin from serum and urine. Quantitation of clusterin mRNA was carried out in 68 bladder tumor specimens from radical cystectomy or transurethral resection and 26 normal bladder specimens from BPH patients by using RT-PCR method. Correlation for the expression of clusterin mRNA with clinicopathologic parameters was analyzed. Serum and urine clusterin was significantly higher in individuals with bladder cancer than control (p = 0.001). Sensitivity and specificity of serum and urine clusterin as a tumor marker for TCC of the bladder was found to be 80%, 91%, 87.1% and 96.7% respectively. Clusterin expression was significantly higher in TCC specimens than normal tissue specimens (P < 0.001). Expression of clusterin was significantly higher in patients with invasive TCC of the bladder than that in patients with superficial TCC and control (P < 0.001). Overexpression of clusterin mRNA was significantly associated with tumor recurrence and overall survival (p < 0.001). The recurrence-free survival time of patients with overexpression of clusterin was significantly shorter than that of patients with weak expression of clusterin (9.8 months vs. 35.2 months). Clusterin may be considered as a potential diagnostic and prognostic biomarker for bladder cancer using urine, serum and/or molecular biology techniques.

Molecular alterations associated with bladder cancer initiation and progression

Bladder cancer is the fifth most commonly diagnosed non-cutaneous solid malignancy, and the second most commonly diagnosed genitourinary malignancy amongst people living in the United States, where it is estimated that more than 61,000 new cases of bladder cancer will be diagnosed in the year 2008. Approximately 90% of malignant tumors arising in the urinary bladder are of epithelial origin, the majority being transitional cell carcinomas. Early stage bladder tumors have been classified into two groups with distinct behavior and unique molecular profiles: low grade tumors (always papillary and usually superficial), and high-grade tumors (either papillary or non-papillary, and often invasive). Clinically, superficial bladder tumors (stages Ta and Tis) account for 75% to 85% of neoplasms, while the remaining 15% to 25% are invasive (T1, T2-T4) or metastatic lesions at the time of initial presentation. Studies from the author's group and others have revealed that distinct genotypic and phenotypic patterns are associated with early versus late stages of bladder cancer. Most importantly, early superficial diseases appear to segregate into two main pathways. Superficial papillary bladder tumors are characterized by gain-of-function mutations, mainly affecting classical oncogenes such as RAS and FGFR3. Deletions of chromosome 9, mainly allelic losses on the long arm (9q) are also frequent events in these tumors. Such genetic alterations are observed in most if not all superficial papillary non-invasive tumors (Ta), but only in a small subset of invasive bladder neoplasms. Flat carcinoma in situ (Tis) and invasive tumors are characterized by loss-of-function mutations, affecting the prototype tumor suppressor genes, including p53, RB and PTEN. These alterations are absent or very rare in the Ta tumors analyzed, but have been frequently identified in invasive bladder carcinomas. Based on these data, a novel model for bladder tumor progression has been proposed in which two separate genetic pathways characterize the evolution of superficial bladder neoplasms. Numerous individual molecular markers have been identified in the tissue specimens that correlate to some extent with tumor stage, and possibly with prognosis in bladder cancer. However, these molecular prognosticators do not play a role in the clinical routine management of patients with bladder tumors, mainly due to lack of large prospective validation studies. Thus, the need for development of specific tissue and serum tumor markers for prognostic stratification remains. The advent of high-throughput microarrays technologies allows comprehensive discovery of targets relevant in bladder cancer progression, which could be translated into new approaches for drug and biomarker development. Further investigation is warranted to define novel biomarkers specific for bladder cancer patients based on the molecular alterations of tumor progression, and multiplexed strategies for clinical management.

Urinary clusterin concentrations--a possible marker of nephropathy? Pilot study

BACKGROUND

Clusterin is a glycoprotein which participates in a number of pathophysiological processes in the organism. Information about clusterin use in the diagnosis of nephropathy and the differential diagnosis of proteinuria has been published recently.

AIM

Search for correlations between urinary clusterin concentration and other renal function markers. Evaluation of urinary clusterin measurement use in the differential diagnosis of nephropathy.

METHODS

Urea, creatinine, IgG, transferin, Na, K in serum and 24-hour collected urine were measured in a sample of 82 individuals. Cystatin C in sera was also measured as were GMT, alpha-1 microglobulin, albumin, total protein in urine. In all probands urinary clusterin was assayed (ELISA).

RESULTS

Urinary clusterin values correlated with urinary total protein concentrations (r = 0.28; p = 0.018), total protein/creatinine index (r = 0.26; p = 0.02). No correlation was found between urine clusterin concentration and glomerular filtration rate, age, urine GMT/creatinine, alpha-1-microglobulin, urine albumin and albumin/creatinine ratio or Na, K fractional excretions. We found no urinary clusterin differences by sex of probands. No evidence of any relationship between urine clusterin and presence of defect of renal function, number of risk factors (chi(2) = 16.0; DF = 15; p = 0.38), albumin/creatinine index (chi(2) = 0.76; DF = 3; p = 0,86), total protein/creatinine (chi(2) = 6.5; DF = 3; p = 0.09), GMT/creatinine (chi(2) = 2.3; DF = 3; p = 0.51), high urinary alpha-1-microglobulin (chi(2) = 4.1; DF = 3; p = 0.25) or decreased of GFR (chi(2) = 1.3; DF = 3; p = 0.74).

CONCLUSIONS

A positive correlation exists between urinary clusterin and urinary total protein and total protein/ creatinine index. Urinary clusterin measurement with ELISA test does not offer any advantage over routinely used parameters for nephropathy diagnosis and the differential diagnosis of proteinuria type.

Clusterin expression in non-neoplastic adenohypophyses and pituitary adenomas: cytoplasmic clusterin localization in adenohypophysis is related to aging

Clusterin is a circulating multifunctional glycoprotein produced in several kinds of epithelial and neuronal cells. Clusterin is upregulated during different physiological and pathological states, such as senescence, type-2 diabetes mellitus, Alzheimer disease, and in various neoplasms. Herein, we investigated the immunohistochemical expression of clusterin in non-neoplastic adenohypophysis of human autopsy subjects and pituitary adenomas. We also investigated the association of clusterin increase with age in adenohypophysis of autopsy subjects. Immunohistochemically, clusterin was found positive in the cytoplasm of all adenoma cases, and in the cytoplasm of parenchymal cells, stellate cells, mixed cell follicles and in colloidal material inside of the follicles of non-neoplastic adenohypophysis as well. Clusterin expression in pituitary adenomas was found significantly higher than in non-neoplastic adenohypophyses. In addition, in non-neoplastic adenohypophysis, a significant increase in clusterin expression levels between young (<or=30 years), middle aged (31 to 60 years), and older (>or=61 years) subjects (p < 0.00001, analysis of variance [ANOVA]) was found. In addition to clusterin accumulation, presence of calcification (p < 0.045, ANOVA) and presence of large follicles with colloid accumulation (p < 0.004, ANOVA) were also statistically significant factors related to aging in non-neoplastic adenohypophysis. In conclusion, the present study demonstrated that clusterin expression was found in non-neoplastic adenohypophysis and in upregulated amounts in pituitary adenomas. This study also demonstrated that in non-neoplastic adenohypophyses, increase of clusterin positive cells; histopathological findings of calcification or presence colloidal material accumulation in large follicles were associated with age. To our knowledge, immunohistochemical localization of clusterin in pituitary adenomas was not reported previously.

Cytoplasmic clusterin expression is associated with longer survival in patients with resected non small cell lung cancer

BACKGROUND

Clusterin is a glycoprotein that has been implicated in many processes, including apoptosis, cell cycle regulation, and DNA repair. Previous studies have examined the prognostic value of clusterin expression in various malignancies. In the present study, we examined clusterin staining in tumors resected from patients with non-small cell lung cancer (NSCLC).

MATERIALS AND METHODS

Tumor specimens were obtained for 113 patients with completely resected NSCLC from paraffin-embedded tissue microarrays and stained with an antibody specific for clusterin. Staining patterns were observed and graded based on intensity and then correlated with clinical data.

RESULTS

Positive cytoplasmic clusterin staining was observed in 44 patients, and weak/negative staining was observed in 62 patients. Patients who had tumors that stained positive for cytoplasmic clusterin had significantly longer survival in multivariate analysis (hazard ratio 0.487, 95% confidence interval 0.27-0.89). A correlation was also observed for recurrence-free survival, which approached statistical significance (hazard ratio 0.345, 95% confidence interval 0.12-1.02). In univariate analysis, patients with clusterin-positive tumors had a 63% 3-year survival, whereas patients with clusterin-negative tumors had a 42% 3-year survival (P = 0.0108); clusterin-positive tumors also had significantly less recurrence (P = 0.0231).

CONCLUSIONS

Cytoplasmic clusterin staining is present in a substantial number of NSCLC tumors and may be a biomarker for longer survival in patients with surgically resected NSCLC.

Molecular alterations associated with bladder cancer progression

Clinically, superficial tumors (stages Ta, Tis, and T1) account for 75% to 85% of bladder neoplasms, while the remaining 15% to 25% are invasive (T2, T3, T4) or metastatic lesions at the time of initial presentation. More than 70% of patients with superficial tumors will have one or more recurrences after initial treatment, and about one third of those patients will progress and eventually die of the disease. New methods are needed to identify and monitor patients presenting with "high-risk" superficial tumors likely to develop into invasive carcinoma. Once invasive into muscle, the natural history is quite variable but highly lethal. Despite aggressive surgical resection, radiotherapy, and/or chemotherapy, the overall cure rate remains in the range of 20% to 50%. New biological determinants are needed both for proper selection of therapy and monitoring. In this review, we describe and update molecular alterations reportedly associated with bladder tumorigenesis and cancer progression. We also review novel genes and "signaling networks" identified by the use of high-throughput technologies. The concept of alterations affecting "genetic pathways" is becoming more than just a molecular biology exercise. The challenge is to evaluate such targets for therapeutic development, as well as to translate progression and outcome biomarkers into improved clinical management. Integration of data generated from in-depth clinical evaluation, histologic tumor characteristics, and validated biomarkers could provide highly accurate, predictive tools for management of the bladder cancer patient.

Endometrial carcinoma biomarker discovery and verification using differentially tagged clinical samples with multidimensional liquid chromatography and tandem mass spectrometry

The utility of differentially expressed proteins discovered and identified in an earlier study (DeSouza, L., Diehl, G., Rodrigues, M. J., Guo, J., Romaschin, A. D., Colgan, T. J., and Siu, K. W. M. (2005) Search for cancer markers from endometrial tissues using differentially labeled tags iTRAQ and cleavable ICAT with multidimensional liquid chromatography and tandem mass spectrometry. J. Proteome Res. 4, 377-386) to discriminate malignant and benign endometrial tissue samples was verified in a 40-sample iTRAQ (isobaric tags for relative and absolute quantitation) labeling study involving normal proliferative and secretory samples and Types I and II endometrial cancer samples. None of these proteins had the sensitivity and specificity to be used individually to discriminate between normal and cancer samples. However, a panel of pyruvate kinase, chaperonin 10, and alpha1-antitrypsin achieved the best results with a sensitivity, specificity, predictive value, and positive predictive value of 0.95 each in a logistic regression analysis. In addition, three new potential markers were discovered, whereas two other proteins showed promising trends but were not detected in sufficient numbers of samples to permit statistical validation. Differential expressions of some of these candidate biomarkers were independently verified using immunohistochemistry.

OUR EXPERIENCES WITH MEASUREMENT OF NEW POTENTIAL BIOMARKERS IN THE DIAGNOSIS OF LATENT FORMS OF MYOCARDIAL ISCHEMIA

BACKGROUND

The need for a laboratory marker of myocardial ischemia has been alluded to for at least the last decade.

AIM

The aim of this study was to evaluate the diagnostic importance of the myosin light chain-1 (MLC-1), clusterin and Reg-Ialpha in patients with suspected myocardial ischemia.

METHODS

A group of 176 at high-risk for myocardial ischemia subjects was evaluated and divided into two subgroups using myocardial SPECT (Single Photon Emission Computed Tomography) - individuals with and without signs of myocardial ischemia. Laboratory markers in venous blood were repeatedly examined in all subjects: a) immediately prior to SPECT: C-reactive protein, Haemoglobin, Hematocrite, Lactate, MLC-1, Clusterin, Reg-Ialpha b) at subjective maximum: Hb, Htc, lactate, MLC-1, Clusterin, Reg-Ialpha c) 30 min after stress levels reached their peak: MLC-1, Clusterin, Reg-Ialpha and d) 60 min after peak stress levels: MLC-1, Clusterin, Reg-Ialpha.

RESULTS

Patients were divided into subgroups according to their positive and negative SPECT results (positive: n = 37; negative: n = 139). MLC-1 values were different for all 4 blood collections. An increase in MLC-1 > 2.2 mg/l showed 64 % sensitivity and 88 % specificity for the diagnosed presence of myocardial ischemia (AUC 0.81; LR+ 5.9; PPV+ 68 % and NPV- 87 %). There was no significant difference between the groups in terms of Clusterin and Reg-Ialpha for any of the sampling periods.

CONCLUSIONS

High diagnostic efficacy of detectable MLC-1 was shown for the diagnosis of latent myocardial ischemia. Measurement of serum Clusterin or Reg-Ialpha did not sufficient for the diagnosis of latent myocardial ischemia.

Expression of clusterin in prostate cancer correlates with Gleason score but not with prognosis in patients undergoing radical prostatectomy without neoadjuvant hormonal therapy

OBJECTIVES

To determine whether the expression level of clusterin in prostate cancer could be used as a prognostic predictor in patients who have undergone radical prostatectomy (RP).

METHODS

This study included 172 consecutive patients undergoing RP for clinically organ-confined prostate cancer without neoadjuvant hormonal therapy. Immunohistochemical staining was performed in RP specimens obtained from these patients to evaluate the expression level of clusterin protein. The cell proliferative activities and apoptotic features in these specimens were investigated using Ki-67 immunostaining and terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling assay, respectively.

RESULTS

Varying levels of clusterin expression were noted in 169 of 172 prostate cancer specimens; 32 of the 172 normal prostatic tissue specimens did not exhibit any clusterin staining. Clusterin expression in prostate cancer tissue was significantly related to the Gleason score, but not to the other parameters, including age, serum prostate-specific antigen level, pathologic stage, perineural invasion, tumor volume, and lymph node metastasis. In addition, cell proliferative activity in the prostate cancer specimens was significantly associated with clusterin expression; however, no correlation was found between the apoptotic index and clusterin expression. In this series, 34 (19.8%) of 172 patients developed biochemical recurrence. No significant difference was found in biochemical/recurrence-free survival between patients with strong clusterin expression and those with weak expression.

CONCLUSIONS

Despite its detection in most prostate cancer tissue, clusterin expression failed to show a significant association with prognosis in patients undergoing RP without neoadjuvant hormonal therapy. This suggests a limited role for clusterin in the progression of clinically organ-confined prostate cancer in the absence of proapoptotic stimuli.