Molecular Markers and Prostate Cancer Prognosis

RETRACTED: MicroRNA-381 facilitates autophagy and apoptosis in prostate cancer cells via inhibiting the RELN-mediated PI3K/AKT/mTOR signaling pathway

This article has been retracted: please see Elsevier Policy on Article Withdrawal (http://www.elsevier.com/locate/withdrawalpolicy). This article has been retracted at the request of the Editor-in-Chief. Concern was raised about the reliability of the Western blot results in Figures 5B+D, 6B+D, 7B+D, and 8C, which appear to have a similar phenotype as many other publications, as detailed here: https://pubpeer.com/publications/70795908CC4CEFC1753E19583700F4; and here: https://docs.google.com/spreadsheets/d/1r0MyIYpagBc58BRF9c3luWNlCX8VUvUuPyYYXzxWvgY/edit#gid=262337249. In addition, a portion of Figure 6C, ‘miR-381 mimic’ group appeared to contain image similarities with Figure 6C, ‘si-RELN’ group. The journal requested that the corresponding author comment on these concerns and provide the raw data. The authors did not respond to this request and therefore the Editor-in-Chief decided to retract the article.

Does the Presence of Hypoechoic Lesions on Transrectal Ultrasound Suggest a Poor Prognosis for Patients With Localized Prostate Cancer?

Purpose

Materials and Methods

Results

Conclusions

The expression of URGCP gene in prostate cancer cell lines: correlation with rapamycin

Molecular targets in prostate cancer are continually being explored, for which there are currently few therapeutic options. Rapamycin (RPM) is an antifungal macrolide antibiotic isolated from Streptomyces hygroscopicus which can inhibit the G1 to S transition. URGCP (upregulator of cell proliferation) is a novel gene located on chromosome 7p13. We aimed to investigate the role of URGCP gene expression changes in PC3, DU145, and LNCAP cell lines with/out RPM. Average cell viability and cytotoxic effect of rapamycin were investigated at 24 h intervals for three days by using Trypan blue dye exclusion test and XTT assay. Cytotoxic effects of rapamycin in DU145, PC3 and LNCAP cells were detected in time and dose dependent manner with the IC(50) doses within the range of 1-100 nM. As the results were evaluated, IC(50) doses in the DU145, PC3, and LNCaP cells were detected as 10, 25, and 50 nM, respectively. The mean relative ratios of URGCP gene expression in DU145, LNCAP and PC3 cells were found as -1.48, 6.59 and -13.00, respectively, when compared to rapamycin-free cells. The False Discovery Rate adjusted p value in DU145, LNCAP and PC3 were 1.25 × 10(-5), 2.20 × 10(-8) and 6.20 × 10(-9), respectively. When the URGCP gene expression level is compared between the dose and control group, we found that URGCP gene expression was significantly decreased in dose groups of DU145 and PC3 cells.

A search for reliable molecular markers of prognosis in prostate cancer: a study of 240 cases

Most prostate cancers are treated, although more than 80% remain clinically insignificant and fewer than 3% are fatal. This retrospective study of 240 radical prostatectomy cases with comprehensive follow-up was a search for reliable markers of prostate cancer prognosis evaluable on biopsy specimens to enable minimization of unnecessary treatment, morbidity, and costs. Representative cancer and benign tissue from each prostatectomy specimen was made into tissue microarrays and stained with antibodies targeting 20 gene sequences. Traditional clinical and pathologic prognosticators and the 20 antibody stains were correlated with patient outcomes. By univariable analysis 4 of 20 antibodies (STMN1/stathmin 1, CYP4Z1/cytochrome p450-4z1, CDH1/E-cadherin, and Hey2), Gleason score, perineural invasion, and apical involvement were statistically significant outcome predictors for biopsy tissue. By multivariate analysis, Gleason score, Hey2, and CYP4Z1 were independently predictive. STMN1 and CDH1 were not independent of Gleason score but remain useful because marker interpretation is objective and Gleason scores often differ for biopsy and prostatectomy specimens.

Beta-2-microglobulin expression correlates with high-grade prostate cancer and specific defects in androgen signaling

BACKGROUND

Previously, we identified Beta-2-microglobulin (beta2M) as an androgen-regulated secreted protein elevated in the serum of prostate cancer patients. In this study, we explore an interaction between beta2M expression, prostate cancer tissue, and the androgen signaling axis.

METHODS

beta2M expression in relation to clinical and pathologic variables was examined in a tissue microarray representing specimens obtained at the time of radical prostatectomy. Viral vectors were designed to down-regulate beta2M expression, and the effects on androgen-dependent growth, transcriptional regulation, and androgen receptor recruitment was investigated in human prostate cancer cell lines.

RESULTS

Variation in beta2M expression in human prostate cancer is associated with characteristics of clinically aggressive disease such as high tumor grade. Knockdown of beta2M expression in human prostate cancer cells resulted in selective defects in androgen-dependent events including growth, gene regulation, and chromatin assembly.

CONCLUSIONS

beta2M expression may provide prognostic information in patients treated with surgery for prostate cancer. Targeting beta2M expression or activity may represent a new and important mechanism to manipulate the androgen signaling axis in patients with prostate cancer.

p53, Bcl-2 and AgNOR tissue markers: model approach in predicting prostate cancer characteristics

The balance between proliferation and apoptosis is represented by changes in the expression of the tissue markers, Bcl-2 and p53, and the presence of silver-stained nucleolar organizing regions (AgNOR) on DNA in prostate adenocarcinomas. Identifying a mathematical model that would take into account the opposing nature of both processes and relate this to cancer stage and grade would be a useful adjunct for studying disease behaviour. This retrospective study investigated tissue marker expression in prostate adenocarcinoma biopsy samples from 17 patients. Staining for p53 was inversely correlated with patient age. Staining for Bcl-2 correlated with the presence of advanced metastatic cancer and American Joint Committee on Cancer (AJCC) disease stage. A mathematical model was developed which combined coded staining intensity data for Bcl-2 and AgNOR, as markers of proliferation, and for p53, as a marker of apoptotis. The mathematical model significantly correlated with Gleason score, AJCC stage and serum prostate specific antigen level, whereas each tissue marker alone did not correlate with all these measures.

Lkb1 deficiency causes prostate neoplasia in the mouse

Mutation of LKB1 is the key molecular event underlying Peutz-Jeghers syndrome, a dominantly inherited condition characterized by a predisposition to a range of malignancies, including those of the reproductive system. We report here the use of a Cre-LoxP strategy to directly address the role of Lkb1 in prostate neoplasia. Recombination of a LoxP-flanked Lkb1 allele within all four murine prostate lobes was mediated by spontaneous activation of a p450 CYP1A1-driven Cre recombinase transgene (termed AhCre). Homozygous mutation of Lkb1 in males expressing AhCre reduced longevity, with 100% manifesting atypical hyperplasia and 83% developing prostate intraepithelial neoplasia (PIN) of the anterior prostate within 2 to 4 months. We also observed focal hyperplasia of the dorsolateral and ventral lobes (61% and 56% incidence, respectively), bulbourethral gland cysts associated with atypical hyperplasia (100% incidence), hyperplasia of the urethra (39% incidence), and seminal vesicle squamous metaplasia (11% incidence). PIN foci overexpressed nuclear beta-catenin, p-Gsk3 beta, and downstream Wnt targets. Immunohistochemical analysis of foci also showed a reduction in Pten activation and up-regulation of both p-PDK1 (an AMPK kinase) and phosphorylated Akt. Our data are therefore consistent with deregulation of Wnt and phosphoinositide 3-kinase/Akt signaling cascades after loss of Lkb1 function. For the first time, this model establishes a link between the tumor suppressor Lkb1 and prostate neoplasia, highlighting a tumor suppressive role within the mouse and raising the possibility of a similar association in the human.

Preoperative serum caveolin-1 as a prognostic marker for recurrence in a radical prostatectomy cohort

PURPOSE

Up-regulation of caveolin-1 (cav-1) is associated with virulent prostate cancer, and serum cav-1 levels are elevated in prostate cancer patients but not in benign prostatic hyperplasia. In this study, we evaluated the potential of high preoperative serum cav-1 levels to predict biochemical progression of prostate cancer. The value of the combined preoperative markers, prostate-specific antigen (PSA), biopsy Gleason score, and serum cav-1 for predicting biochemical recurrence was also investigated.

EXPERIMENTAL DESIGN

Serum samples taken from 419 prostate cancer patients before radical prostatectomy were selected from our Specialized Programs of Research Excellence prostate cancer serum and tissue bank. Serum samples were obtained 0 to 180 days before surgery and all patients had complete data on age, sex, race, stage at enrollment, and follow-up for biochemical recurrence. Serum cav-1 levels were measured according to our previously reported ELISA protocol.

RESULTS

Cav-1 levels were measured in the sera of 419 prostate cancer patients; the mean serum level was 4.52 ng/mL (median 1.01 ng/mL). Patients with high serum cav-1 levels had a 2.7-fold (P = 0.0493) greater risk of developing biochemical recurrence compared with those with low serum cav-1 levels. Importantly, patients with serum PSA >/= 10 ng/mL and elevated levels of serum cav-1 had 2.44 times higher risk (P = 0.0256) of developing biochemical recurrence compared with patients with low levels of cav-1. In addition, high serum cav-1 levels combined with increasing biopsy Gleason score predicted much shorter recurrence-free survival in the group of patients with PSA >/= 10 ng/mL (P = 0.0353). Cav-1 was also able to distinguish between high- and low- risk patients with biopsy Gleason score of seven, after adjusting, for patients PSA levels (P = 0.0429).

CONCLUSIONS

Overall, elevated preoperative levels of serum cav-1 predict decreased time to cancer recurrence. In the subset of patients with serum PSA of >/=10 ng/mL, the combination of serum cav-1 and biopsy Gleason score has the capacity to predict time to biochemical recurrence.

Mechanisms and markers of carcinogenesis and neoplastic progression

Neoplastic transformation evolves over a period of time involving the progression of the cellular immunophenotype (IP) from normal to hyperplastic to dysplastic, and finally, to fully malignant IPs. Superimposed on these changes is the interaction of the initiated cell with its microenvironment, whereby the neoplastically transformed cells, through the regulation or dysregulation of cytoskeletal, integrin, protease and adhesion molecules, develop a novel manner of relation with their surrounding microenvironment. Studies of the neuroendocrine-immune network revealed that the hormonal and cytokine milieu plays an important role impacting the growth and dedifferentiation capabilities of neoplastic cells. This is further affected by the tumour cells themselves determining the constitution of this hormonal microenvironment, allowing the most aggressive and invasive of neoplastically transformed cell clones to promote their own growth and dissemination. The elucidation of the steps of the progression of cancer from premalignant to metastatic and invasive forms is of utmost importance in the differential diagnosis of neoplasms and in the establishment of more efficacious therapeutic regimens. These regimens will certainly begin to take on a more individualised form. The functional characterisation of various human malignancies as to the neoplastically transformed cells' IP, the bases of their interaction with tissue stromal elements, and the molecules involved in the humoral microenvironment of the particular stage of tumour will certainly allow for the better diagnosis, staging, prognostication and treatment of cancers in the future. This paper reviews carcinogenesis from nutritional, genetic and molecular, and humoral aspects, and discusses the importance of tumour markers in the diagnosis and therapeutic management of human cancer.

Gene delivery and gene therapy of prostate cancer

Surgery, radiation or hormonal therapy are not adequate to control prostate cancer. Clearly, other novel treatment approaches, such as gene therapy, for advanced/recurrent disease are desperately needed to achieve long-term local control and particularly to develop effective systemic therapy for metastatic prostate cancer. In the last decade, significant progress in gene therapy for the treatment of localised prostate cancer has been demonstrated. A broad range of different gene therapy approaches, including cytolytic, immunological and corrective gene therapy, have been successfully applied for prostate cancer treatment in animal models, with translation into early clinical trials. In addition, a wide variety of viral and nonbiological gene delivery systems are available for basic and clinical research. Gene therapy approaches that have been developed for the treatment of prostate cancer are summarised.