Expression of potential molecular markers in prostate cancer: Correlation with clinicopathological outcomes in patients undergoing radical prostatectomy

Anoikis in prostate cancer bone metastasis gene signatures and therapeutic implications

Background

Bone metastasis from prostate cancer severely impacts patient outcomes and quality of life. Anoikis, a form of programmed cell death triggered by the loss of cell-matrix interactions, plays a critical role in cancer progression. However, its precise relationship with prostate cancer-induced bone metastasis remains unclear. This study aims to elucidate this relationship, focusing on anoikis-related gene signatures, molecular pathways, and therapeutic implications.

Methods

We used the TCGA-PRAD dataset for training, with MSKCC and GSE70769 as validation cohorts. To evaluate immunotherapy efficacy, we examined IMvigor 210 and GSE91016 datasets, and GSE137829 provided single-cell insights into prostate cancer. Specific anoikis-related genes (ARGs) were identified, and Random Survival Forest analysis and multivariate Cox regression were employed to develop anoikis-linked features. The 'clustanoikisProfilanoikis' and 'GSEA' packages were used to explore potential ARG-related pathways.

Results

Analyzing 553 samples from TCGA, 231 from MSKCC, 94 from GSE70769, and single-cell data from 6 prostate cancer patients (GSE137829), we constructed a prognostic model based on 9 ARGs. GSVA revealed upregulation of carcinogenic pathways, including epithelial-mesenchymal transition, E2F targets, and angiogenesis, with downregulation of metabolic pathways. Significant differences in somatic mutations were observed between cohorts, with a positive correlation between anoikis scores and tumor mutational burden (TMB). Immune landscape analysis suggested high-risk patients might benefit more from chemotherapy than immunotherapy based on their risk score. Single-cell analysis indicated overactivation of carcinogenic pathways in the high anoikis score group.

Conclusion

This study elucidates the complex interplay between anoikis and bone metastasis in prostate cancer. Our findings highlight the critical role of anoikis in metastatic progression, enhancing the understanding of key biomarkers and molecular dynamics. The identified anoikis-related gene signatures and disrupted pathways offer promising avenues for predictive and therapeutic strategies in prostate cancer management.

Evidence of the Link between Stroma Remodeling and Prostate Cancer Prognosis

Prostate cancer (PCa), the most commonly diagnosed cancer in men worldwide, is particularly challenging for oncologists when a precise prognosis needs to be established. Indeed, the entire clinical management in PCa has important drawbacks, generating an intense debate concerning the possibility to individuate molecular biomarkers able to avoid overtreatment in patients with pathological indolent cancers. To date, the paradigmatic change in the view of cancer pathogenesis prompts to look for prognostic biomarkers not only in cancer epithelial cells but also in the tumor microenvironment. PCa ecology has been defined with increasing details in the last few years, and a number of promising key markers associated with the reactive stroma are now available. Here, we provide an updated description of the most biologically significant and cited prognosis-oriented microenvironment biomarkers derived from the main reactive processes during PCa pathogenesis: tissue adaptations, inflammatory response and metabolic reprogramming. Proposed biomarkers include factors involved in stromal cell differentiation, cancer-normal cell crosstalk, angiogenesis, extracellular matrix remodeling and energy metabolism.

Current evidence on the relationships among five polymorphisms in the matrix metalloproteinases genes and prostate cancer risk

Matrix metalloproteinases (MMPs) had a variety of subtypes, which may be related to tumor invasion and angiogenesis, and the polymorphisms from MMPs have been also associated with the susceptibility to a variety of tumors, including prostate cancer (PCa). However, previous studies have not systematically analyzed the association between MMP and prostate cancer, so we conducted systematic data collection and analyzed to evaluate the relationship among polymorphisms in MMPs and PCa susceptibility. We searched PubMed, Web of Science, Embase and Google Scholar for all papers published up to Apr 3rd, 2023, and systematically analyzed the relationship among MMP1-1607 2G/1G, MMP2-1306 T/C, MMP2-735 T/C, MMP7-181 G/A, MMP9-1562 T/C and PCa susceptibility using multiple comparative models and subgroup analyses. We found that MMP2-1306 T/C polymorphism showed associations with PCa susceptibility, with the Ethnicity subgroup (Asian) being more pronounced. Similarly, MMP9-1562 T/C has also had associations with PCa susceptibility. Our current study found that the polymorphisms of, MMP2-1306 T/C, and MMP9-1562 T/C had strong associations with PCa risk.

Natural Products as Regulators against Matrix Metalloproteinases for the Treatment of Cancer

Cancers are currently the major cause of mortality in the world. According to previous studies, matrix metalloproteinases (MMPs) have an impact on tumor cell proliferation, which could lead to the onset and progression of cancers. Therefore, regulating the expression and activity of MMPs, especially MMP-2 and MMP-9, could be a promising strategy to reduce the risk of cancers. Various studies have tried to investigate and understand the pathophysiology of cancers to suggest potent treatments. In this review, we summarize how natural products from marine organisms and plants, as regulators of MMP-2 and MMP-9 expression and enzymatic activity, can operate as potent anticancer agents.

Metalloproteinase 9 immunostaining profile is positively correlated with tumor grade, extraprostatic extension and biochemical recurrence in prostate cancer

Metastasis is the main problem in the treatment of prostate cancer (PCa), and for it to occur, proteolytic enzymes must remodel the extracellular matrix (ECM) surrounding the tumor. The most important group of enzymes with this action include the matrix metalloproteinases (MMPs), which act on various substrates cleaving ECM components. The present study aimed to evaluate the protein immunostaining profiles of matrix metalloproteinase 2 (MMP-2) and 9 (MMP-9) in PCa Brazilian patients using the indirect immunohistochemical methodology. The tissue samples (n = 178), 60 from malignant tumor, 58 from adjacent non-tumor, and 60 from ECM, were evaluated according to the immunostaining intensity. The malignant tumor cytoplasmic MMP-2 immunostaining was more intense than in ECM (p = 0.001), but it did not correlate with any clinical-pathological parameter. The MMP-9 staining was similar in tumor cytoplasm, adjacent non-tumor cytoplasm and ECM, but showed significant positive correlations with ISUP grade (p = 0.044; Tau=0.249), extraprostatic extension (p = 0.025; Tau=0.309), and biochemical recurrence (p = 0.048; Tau=0.306). A significant positive correlation was also observed between MMP-2 and MMP-9 in all cell compartments analyzed. Although further research is warranted to elucidate the precise mechanisms underlying these observations, our findings suggest MMP-9 as a promising candidate marker for tissue invasion that could be used in predicting the progression and prognosis of PCa.

The Role of the Metzincin Superfamily in Prostate Cancer Progression: A Systematic-Like Review

Prostate cancer remains a leading cause of cancer-related morbidity in men. Potentially important regulators of prostate cancer progression are members of the metzincin superfamily of proteases, principally through their regulation of the extracellular matrix. It is therefore timely to review the role of the metzincin superfamily in prostate cancer and its progression to better understand their involvement in this disease. A systematic-like search strategy was conducted. Articles that investigated the roles of members of the metzincin superfamily and their key regulators in prostate cancer were included. The extracted articles were synthesized and data presented in tabular and narrative forms. Two hundred and five studies met the inclusion criteria. Of these, 138 investigated the role of the Matrix Metalloproteinase (MMP) subgroup, 34 the Membrane-Tethered Matrix Metalloproteinase (MT-MMP) subgroup, 22 the A Disintegrin and Metalloproteinase (ADAM) subgroup, 8 the A Disintegrin and Metalloproteinase with Thrombospondin Motifs (ADAMTS) subgroup and 53 the Tissue Inhibitor of Metalloproteinases (TIMP) family of regulators, noting that several studies investigated multiple family members. There was clear evidence that specific members of the metzincin superfamily are involved in prostate cancer progression, which can be either in a positive or negative manner. However, further understanding of their mechanisms of action and how they may be used as prognostic indicators or molecular targets is required.

Effect of chronic stress on expression and secretion of seminal vesicle proteins in adult rats

Chronic stress (CS) is known to affect men's health especially fertility by reducing semen quality. Although the effects of CS on testicular function and sperm parameters are documented, changes of substances and secreting proteins in the seminal vesicle (SV) have never been reported. This study aimed to demonstrate the alterations of contents and expressions of proteins in seminal vesicle fluid (SVF) under CS. Fourteen adult rats were divided into control and CS groups (n = 7/each). Control rats were not exposed to stressor, while the CS animals were immobilised by restraint cage (4 hr/day) and followed by forced swimming (15 min/day) for consecutive 60 days. Biochemical substances and malondialdehyde (MDA) level in SVF were examined. Expressions of heat-shock protein 70 (Hsp70), caspases (Casp) 3 and 9, and tyrosine-phosphorylated (TyrPho) proteins were investigated in seminal vesicle tissue (SVT) and SVF. It was found that CS caused reductions of seminal epithelial height and secreted substance levels. Significantly, MDA levels in SVF and expressions of Hsp70, Casp and TyrPho proteins were increased in of CS animals. It was concluded that CS affected seminal secretion. Low quality of CS seminal plasma may associate with increase of MDA and expressions of secreted proteins.

Prediction of Radioresistant Prostate Cancer Based on Differentially Expressed Proteins

INTRODUCTION

Although relapses after radiotherapy are common in prostate cancer (PCA) patients, those with a high risk for radioresistance cannot be identified prior to treatment yet. Therefore, this proof-of-concept study was performed to compare protein expression profiles of patients with radio-recurrent PCA to patients treated with primary radical prostatectomy separated by Gleason risk groups. We hypothesized that radio-recurrent PCA have a similar protein expression as high-risk Gleason PCA.

METHODS

Patient cohorts consisted of (i) 31 patients treated with salvage prostatectomy for locally recurrent PCA after primary radiotherapy and (ii) 94 patients treated with primary prostatectomy split into a Gleason high-risk (≥4 + 3; n = 42 [44.7%]) versus a low-risk group (≤3 + 4; n = 52 [55.3%]). Immunohistochemistry was performed using 15 antibodies with known association to radioresistance in PCA in vitro. ELISA was used for validation of selected markers in serum.

RESULTS

Androgen receptor (AR) was overexpressed in most radio-recurrent PCA (89.7%) and in most primary high-risk Gleason PCA (87.8%; p = 0.851), while only 67.3% of the low-risk group showed an expression (p = 0.017). Considering the highest Gleason pattern in primary PCA, aldo-keto reductase family 1 member C3 (AKR1C3) was most similarly expressed by patients with radio-recurrent PCA and patients with Gleason patterns 4 and 5 (p = 0.827 and p = 0.893) compared to Gleason pattern 3 (p = 0.20). These findings were supported by ELISA.

CONCLUSION

This is the first study to evaluate protein markers in order to predict radioresistance in PCA. Our results point to AR and AKR1C3 as the most promising markers that might help stratify patients for radiotherapy.

Association between focal adhesion kinase and matrix metalloproteinase-9 expression in prostate adenocarcinoma and their influence on the progression of prostatic adenocarcinoma

Focal adhesion kinase (FAK), a member of the non-receptor cytoplasmic tyrosine kinase family, is associated with the development and progression of cancer. Matrix metalloproteinase-9 (MMP-9) is directly involved in the degradation of the extracellular matrix, and basement membrane components promote cancer cell migration and invasion. There is a functional interaction among FAK, MMP-9 and vascular endothelial growth factor (VEGF), which leads to enhanced cancer angiogenesis, cancer cell invasion and progression of malignancy. FAK, MMP-9, VEGF and CD34-positive microvessel density (MVD) were examined in 100 patients with prostate adenocarcinoma using immunohistochemistry. The relationship among these proteins and their impact on angiogenesis and clinicopathological parameters were also evaluated. The FAK expression was found to be positively correlated with the Gleason score, WHO grade group, tumour stage, extracapsular extension and perineural invasion. The MMP-9 expression was positively correlated with the WHO grade group, tumour stage, extracapsular extension, positive surgical margin and lymphovascular and perineural invasion. The FAK expression was also positively correlated with MMP-9 expression and MVD. However, no correlation between FAK and VEGF expression was identified. The MMP-9 expression was positively correlated with FAK expression and MVD. Strong MMP-9 expression was associated with shorter disease-free survival. These results suggest that strong MMP-9 and FAK expressions play an essential role in the progression of prostate adenocarcinoma. Further investigations should be conducted to determine the importance of these proteins as therapeutic targets for patients with prostate adenocarcinomas.

Expression of small heat shock proteins in exosomes from patients with gynecologic cancers

Small Heat shock proteins (sHsp) are a group of chaperone proteins. Under conditions of stress, the expression of sHsp is increased. Therefore, they are implicated in the pathogenesis of various autoimmune-mediated disorders and cancer. The purpose of this study was to analyze sHsp expression in exosomes from patients with gynecologic cancers and correlate these results with markers of cytotoxic immune response. The study group included patients with ovarian cancer, endometrial cancer, and patients with endometriosis. The levels of sHsps and cytotoxic markers were analyzed in serum, peritoneal fluid and exosomes using ELISA method. We found the highest levels of sHsp in exosomes from patients with ovarian cancer, but they were also elevated in patients with endometrial cancer and endometriosis. Moreover, we identified the presence of small Hsps in serum and peritoneal fluid in all study groups, but again the highest level was in patients with ovarian cancer. Small Hsps expression levels were positively correlated with markers of cytotoxic immune response.

RNA-based markers in biopsy cores with atypical small acinar proliferation: Predictive effect of T2E fusion positivity and MMP-2 upregulation for a subsequent prostate cancer diagnosis

BACKGROUND

Atypical small acinar proliferation (ASAP) is a precursor lesion of prostate cancer (PC), and PC develops from this suspicious focus or an unsampled malignant gland nearby. However, PC-related molecular alterations that could guide the timing of repeat biopsies and help monitor PC risk in ASAP-diagnosed patients have not been investigated. The purpose of this study was to first investigate the expression of seven different PC-related RNAs that included serine 2 (TMPRSS2): erythroblastosis virus E26 oncogene homolog (ERG) gene (TMPRSS2-ERG, T2E) fusion, alpha-methylacyl-CoA racemase (AMACR), kallikrein related peptidase 3 (KLK3), androgen receptor (AR), prostate cancer specific antigen 3 (PCA3), and matrix metalloproteinases (MMP)-2 and 9.

METHODS

PC-related RNAs were evaluated using a real-time quantitative reverse transcription polymerase chain reaction (RT-qPCR) system in pathologically ASAP-diagnosed prostate biopsy cores from 55 patients presenting with a normal digital rectal examination and a PSA level of 4-10 ng/mL.

RESULTS

We detected that positive T2E fusion status (P = 0.013) and the expression of AMACR (P = 0.016), AR (P = 0.016) and MMP-2 (P = 0.013) were independently and significantly associated with PC risk in ASAP patients. There were also several statistically significant correlations between expression levels. Additionally, we demonstrated that T2E fusion positive ASAP patients with higher MMP-2 expression were more likely to be diagnosed with PC at a subsequent biopsy during the follow-up period (P = 0.003).

CONCLUSIONS

Although, more clinical validations are needed for the stratification of PC risk in ASAP-diagnosed biopsy cores, our current results indicate that the coexistence of T2E fusion positivity with MMP-2 upregulation may help clinicians adjust their biopsy timetable and/or assessment of PC risk in ASAP-diagnosed patients with a PSA level of 4-10 ng/mL.

Neoadjuvant endocrine therapy with exemestane followed by response-guided combination therapy with low-dose cyclophosphamide in postmenopausal patients with estrogen receptor-positive breast cancer: A multicenter, open-label, phase II study

Patients with estrogen receptor (ER)‐positive breast cancer are less likely to achieve a pathological complete response (pCR) with neoadjuvant chemotherapy. Neoadjuvant endocrine therapy may be more appropriate than neoadjuvant chemotherapy in these hormone‐sensitive patients. Most patients with ER‐positive breast cancer are postmenopausal, and therefore, generally older and less able to tolerate chemotherapy. We aimed to investigate the efficacy and safety of tailored neoadjuvant endocrine and chemoendocrine therapy for postmenopausal breast cancer patients. Untreated patients with primary invasive ER‐positive, HER2‐negative, stage I‐IIIA breast cancer, and Ki67 index ≤30% were enrolled. Patients received exemestane 25 mg/d for 12 weeks. Based on clinical response and change in Ki67 index, assessed at 8‐12 weeks, patients with complete response (CR), partial response (PR) with Ki67 index ≤5% after treatment, or stable disease (SD) with Ki67 index ≤5% before and after treatment were defined as responders. For the subsequent 24 weeks, responders continued exemestane monotherapy (group A), and nonresponders received exemestane 25 mg/d plus cyclophosphamide 50 mg/d (group B). The primary endpoint was clinical response at weeks 24 and 36. A total of 59 patients (median age, 69 years) started initial exemestane monotherapy. After exclusion of three patients who discontinued during this period, 56 remained enrolled to receive subsequent treatment. Clinical response rates (CR and PR) and 95% CI at weeks 24 and 36 were 85% (12/14; 57.2%‐98.2%) and 71% (10/14; 41.9%‐91.6%), respectively, in group A; and 54% (23/42; 38.7%‐70.2%) and 71% (30/42; 55.4%‐84.3%), respectively, in group B. At week 36, no significant difference was found in median Ki67 index between the groups (3.5% and 4.0%). There were no treatment‐related deaths. We found that clinical response comparable to that of responders was achieved in nonresponders after addition of cyclophosphamide to the initial endocrine therapy.

High immunoexpression of Ki67, EZH2, and SMYD3 in diagnostic prostate biopsies independently predicts outcome in patients with prostate cancer

INTRODUCTION

Overtreatment is a major concern in patients with prostate cancer (PCa). Prognostic biomarkers discriminating indolent from aggressive disease in prostate biopsy are urgently needed. We aimed to evaluate the prognostic value of Ki67, EZH2, LSD1, and SMYD3 immunoexpression in diagnostic biopsies from a cohort of PCa patients with long term follow-up.

MATERIALS AND METHODS

A series of 189 consecutive prostate biopsies diagnosed with PCa (1997-2001) in a cancer center was included in the study, with follow-up last updated in November 2016. Biopsies were reviewed and graded according to 2016 WHO criteria. Immunohistochemistry was performed in the most representative block. Nuclear staining was assessed using digital image analysis. Study outcomes included disease-specific, disease-free, and progression-free survival. Statistical analysis was tabulated using SPSS version 22.0. Survival curves and hazard ratios (HRs) were estimated using Kaplan-Meyer and Cox-regression models, respectively. Statistical significance was set at P<0.05.

RESULTS

The proportion of patients who completed the study was 177/189 (94%). In univariable analysis, high Ki67, EZH2, and SMYD3 immunoexpression associated with significantly worse disease-specific survival (HR = 1.86, 95% CI: 1.05-3.29; HR = 1.87, 95% CI: 1.10-3.27; HR = 2.68, 95% CI: 1.02-7.92). In multivariable analysis, the 3 biomarkers displayed significantly worse DSS adjusted for CAPRA score (HR = 1.78, 95% CI: 1.01-3.16; HR = 1.93, 95% CI: 1.12-3.32; HR = 2.71, 95% CI: 1.04-7.10). Among patients with low/intermediate risk CAPRA score, high Ki67 immunoexpression identified those more prone to experience disease recurrence (HR = 9.20, 95% CI: 1.27-66.44) and progression (HR = 2.97, 95% CI: 1.05-8.43).

CONCLUSIONS

High Ki67, EZH2, and SMYD3 immunoexpression, adjusted for standard clinicopathological parameters, independently predicts outcome in patients with PCa, at diagnosis. This might assist in discriminating indolent from aggressive PCa, improving treatment selection.

Matrix Metalloproteinases: A challenging paradigm of cancer management

Matrix metalloproteinases (MMPs) are members of zinc-dependent endopeptidases implicated in a variety of physiological and pathological processes. Over the decades, MMPs have been studied for their role in cancer progression, migration, and metastasis. As a result, accumulated evidence of MMPs incriminating role has made them an attractive therapeutic target. Early generations of broad-spectrum MMP inhibitors exhibited potent inhibitory activities, which subsequently led to clinical trials. Unexpectedly, these trials failed to meet the desired goals, mainly due to the lack of efficacy, poor oral bioavailability, and toxicity. In this review, we discuss the regulatory role of MMPs in cancer progression, current strategies in targeting MMPs for cancer treatment including prodrug design and tumor imaging, and therapeutic value of MMPs as biomarkers in breast, lung, and prostate cancers.

Associations of Prostate-Specific Antigen, Prostate Carcinoma Tissue Gleason Score, and Androgen Receptor Expression with Bone Metastasis in Patients with Prostate Carcinoma

Background

Prostate carcinoma (PCa) is often not diagnosed until advanced disease with bone metastasis. Predictive factors for bone metastasis are required to improve patient outcomes. The study aimed to analyze the factors associated with bone metastases in newly diagnosed patients with PCa.

Material/Methods

This was a retrospective study of 80 patients newly diagnosed with PCa by pathological examination between January 2012 and December 2014. Bone metastases were diagnosed by positron emission computed tomography. Clinical data, serological laboratory results, and pathological examination results were collected.

Results

Among the 80 patients, 45 (56%) had bone metastases. Age, serum alkaline phosphatase, prostate-specific antigen (PSA), erythrocyte sedimentation rate, PCa tissue Gleason score, androgen receptor (AR) expression, and Ki-67 expression were higher in patients with bone metastasis compared with those without (all P<0.05). Multivariate logistic regression showed that PSA (OR: 1.005; 95%CI: 1.001–1.010; P=0.016), Gleason score (OR: 4.095; 95%CI: 1.592–10.529; P=0.003), and AR expression (OR: 14.023; 95%CI: 3.531–55.6981; P=0.005) were independently associated with bone metastases. Cut-off values for PSA, Gleason score, and AR expression were 67.1 ng/ml (sensitivity: 55.6%; specificity: 97.1%), 7.5 (sensitivity: 75.6%; specificity: 82.9%), and 2.5 (sensitivity: 84.0%; specificity: 91.4%), respectively.

Conclusions

PSA, Gleason score, and AR expression in PCa tissues were independently associated with PCa bone metastases. These results could help identifying patients with PCa at high risk of bone metastases.

Expression of NGF, GDNF and MMP-9 in prostate carcinoma

The aim of the present study was to investigate the immunohistochemical expression of NGF, GDNF and MMP-9 in benign prostatic hyperplasia (BPH), high grade prostatic intraepithelial neoplasia (HGPIN) and prostate cancer (PC), and to analyse their association with the clinicopathological parameters in PC cases. Immunohistochemistry was performed on the tissue microarray (TMA) sections of 30 BPH, 40 HGPIN and 121 primary PC tissues. There was a significant difference regarding the expression of NGF and GDNF between PC and HGPIN (p<0.0001; p<0.0001), and PC and BPH (p=0.001; p<0.0001), but not between HGPIN and BPH (p>0.05). Furthermore MMP-9 expression was significantly different among all groups (PC vs. HGPIN, p<0.0001; PC vs. BPH, p<0.0001; HGPIN vs. BPH, p=0.001). NGF, GDNF and MMP-9 expression was significantly stronger in cases with high Gleason score (p<0.0001, p=0.004, p<0.0001 respectively) and pT stage (p=0.046, p=0.004, p=0.001, respectively) in PC cases. All these markers were also associated with perineural, lymphovascular and extraprostatic invasion (p <0.05). In addition, a positive correlation was found between NGF and MMP-9 (p<0.0001, r=0.435), NGF and GDNF (p<0.0001, r=0.634), and GDNF and MMP-9 (p<0.0001, r=0.670) in PC cases. According to our results we suggest an interaction between NGF, GDNF and MMP-9 during the transition to malignancy in PC. Also this interaction may involve in regulating PC cell differentiation, tumor invasion, progression, and the agressiveness of PC.

Survival predictors in patients with prostate adenocarcinoma with hormonal blockade

Ki-67 index and clinical-pathological factors such as the Gleason score and the presence of neuroendocrine differentiation have been used for predicting survival in patients with prostate cancer. We examined prostate tissue from 45 patients with advanced prostate cancer who were treated with maximal androgen blockade and analysed their cancer-specific survival (CSS). We assessed the Gleason index, performed an immunohistochemical analysis of Ki-67 (MIB-1) and determined the presence of neuroendocrine differentiation (chromogranin A). A survival study was conducted using Kaplan-Meier curves (log-rank test) and a Cox regression analysis. Twenty-four patients (53.3%) died from the disease, with a mean follow-up of 68.7±7.7 months (56.6% CSS at 5 years and 31.8% at 10 years). In the univariate analysis, survival was associated with an interquartile distribution of Ki-67 (0-5, 6-12%, 13-25%, >25%; log-rank, p=0.01), Gleason 5 (total index 9-10; log-rank, p=0.002) and the presence of metastases during the diagnosis (M1; log-rank, p=0.004) but not to cT category (T3-T4; log-rank, p=0.26) or neuroendocrine differentiation (immunohistochemically positive tumour cell nests; log-rank, p=0.46). The multivariate analysis revealed that a Ki-67 index ≤12% (HR, 0.22; p=0.0009) and the absence of metastases (M0) during diagnosis (HR, 0.17; p=0.0002) were protective factors in this population. In conclusion, Ki-67 proliferation index and the lack of metastases at diagnosis predict CSS in patients with advanced prostate cancer who undergo hormonal blockade. Neuroendocrine differentiation in tumour tissue had no prognostic value in this study.

GLI2 expression levels in radical nephrectomy specimens as a predictor of disease progression in patients with metastatic clear cell renal cell carcinoma following treatment with sunitinib

The aim of the present study was to investigate the role of the Hedgehog signaling pathway in the progression of metastatic clear cell renal cell carcinoma (m-ccRCC) as well as the molecular targets of sunitinib, an inhibitor of multiple tyrosine kinases. A total of 39 patients subjected to radical nephrectomy who were diagnosed with m-ccRCC and were subsequently treated with sunitinib were enrolled in the present study. The expression levels of the Hedgehog signaling proteins (GLI1, GLI2, cyclin D1, cyclin E and transforming growth factor-β) and major molecular targets of sunitinib [vascular endothelial growth factor receptor (VEGFR)-1 and −2, and platelet-derived growth factor receptor-α and -β] in primary RCC specimens were assessed by immunohistochemical staining. The expression levels of GLI2, VEGFR-1, VEGFR-2 and pre-treatment C-reactive protein as well as the Memorial Sloan-Kettering Cancer Center risk were identified as significant predictors of progression-free survival (PFS). Of these, only GLI2 expression was independently correlated to PFS according to multivariate analysis. Furthermore, treatment with sunitinib resulted in a marked inhibition of GLI2 expression in the parental human RCC ACHN cell line, but not in ACHN cells with acquired resistance to sunitinib. These findings suggested that GLI2 may be involved in the acquisition of resistance to sunitinib in RCC; thus, it may be useful to consider the expression levels of GLI2 in addition to conventional prognostic parameters when selecting m-ccRCC patients likely to benefit from treatment with sunitinib.

Prognostic value of Ki67 in localized prostate carcinoma: a multi-institutional study of >1000 prostatectomies

BACKGROUND

Expanding interest in and use of active surveillance for early state prostate cancer (PC) has increased need for prognostic biomarkers. Using a multi-institutional tissue microarray resource including over 1000 radical prostatectomy samples, we sought to correlate Ki67 expression captured by an automated image analysis system with clinicopathological features and validate its utility as a clinical grade test in predicting cancer-specific outcomes.

METHODS

After immunostaining, the Ki67 proliferation index (PI) of tumor areas of each core (three cancer cores/case) was analyzed using a nuclear quantification algorithm (Aperio). We assessed whether Ki67 PI was associated with clinicopathological factors and recurrence-free survival (RFS) including biochemical recurrence, metastasis or PC death (7-year median follow-up).

RESULTS

In 1004 PCs (∼4000 tissue cores) Ki67 PI showed significantly higher inter-tumor (0.68) than intra-tumor variation (0.39). Ki67 PI was associated with stage (P<0.0001), seminal vesicle invasion (SVI, P=0.02), extracapsular extension (ECE, P<0.0001) and Gleason score (GS, P<0.0001). Ki67 PI as a continuous variable significantly correlated with recurrence-free, overall and disease-specific survival by multivariable Cox proportional hazard model (hazards ratio (HR)=1.04-1.1, P=0.02-0.0008). High Ki67 score (defined as ⩾5%) was significantly associated with worse RFS (HR=1.47, P=0.0007) and worse overall survival (HR=2.03, P=0.03).

CONCLUSIONS

In localized PC treated by radical prostatectomy, higher Ki67 PI assessed using a clinical grade automated algorithm is strongly associated with a higher GS, stage, SVI and ECE and greater probability of recurrence.

Proteases as prognostic markers in human and canine cancers

The extracellular matrix (ECM) is composed of several types of proteins, which interact and form dynamic networks. These components can modulate cell behaviour and actively influence the growth and differentiation of tissues. ECM is also important in several pathological processes, such as cancer invasion and metastasis, by creating favourable microenvironments. Proteolysis in neoplastic tissues is mediated by proteinases, whose regulation involves complex interactions between neoplastic cells and non-neoplastic stromal cells. In this review, we discuss aspects of proteinase expression and tumor behaviour in humans and dogs. Different classes of proteases are summarized, with special emphasis being placed on molecules that have been shown to correlate with prognosis, reinforcing the need for a better understanding of the regulation of this microenvironment and its influences in tumor progression and metastasis, which should significantly aid the development of improved prognosis and treatment.

Association of molecular biomarkers expression with biochemical recurrence in prostate cancer through tissue microarray immunostaining

The aim of the present study was to investigate the prognostic role of metallothionein-2A (MT-2A), E-cadherin, interleukin-6 (IL-6), cyclin-E, proliferating cell nuclear antigen (PCNA) and B cell lymphoma (Bcl)-2 in the biochemical recurrence of prostate cancer (PCa) using tissue microarray immunostaining. Tissue specimens from 128 PCa patients who underwent radical prostatectomy were processed and transferred onto tissue microarrays. The clinicopathological parameters of PCa patients were also recorded. Following immunohistochemical examination of MT-2A, E-cadherin, IL-6, cyclin-E, PCNA and Bcl-2 expression in PCa specimens, association analysis of biomarkers expression with the biochemical recurrence of PCa was performed. The results revealed that the overall rate of biochemical recurrence was 30.5% (39/128) and the median biochemical recurrence-free time was 19 months (range, 6–35 months). The biochemical recurrence rates in low-, intermediate- and high-risk PCa classification were 14.8 (8/54), 38.7 (24/62) and 58.3% (7/12), respectively. Survival analysis demonstrated that a decreased biochemical recurrence-free survival rate was noted in PCa cases with positive MT-2A and cyclin E expression as well as those with negative E-cadherin expression (P=0.022, 0.028 and 0.011, respectively). Subsequent multivariate Cox analysis revealed that MT-2A [hazard ratio (HR)=2.01; 95% confidence interval (CI)=1.08–3.15; P=0.005], E-cadherin (HR=1.79; 95% CI=1.08–2.21; P=0.042) and cyclin E (HR=1.92; 95% CI=1.22–2.45; P=0.020) were independent predictors of the biochemical recurrence of PCa. In conclusion, the present study provided clinical evidence that evaluation of molecular biomarkers expression may improve clinical prognostic accuracy for the biochemical recurrence of PCa. Of note, the expression of MT-2A, cyclin E and E-cadherin may serve as independent predictors for biochemical recurrence of PCa.

Expression levels of heat shock protein 27 and cellular FLICE-like inhibitory protein in prostate cancer correlate with Gleason score sum and pathologic stage

Purpose

Heat shock protein (HSP) 27 protects the cell by controlling apoptosis and immune reactions, and c-FLIP (cellular-FLICE inhibitory protein) inhibits apoptosis by inhibiting caspase-8 activity. We investigated the relationship of HSP27 and c-FLIP expression to prostate-specific antigen, Gleason score sum (GSS), and pathologic stage.

Materials and Methods

Samples from 163 patients between May 2004 and April 2010 were analyzed: 83 from patients that had underwent a radical prostatectomy, and 80 from those that underwent transurethral resection of the prostate to alleviate urinary symptoms from benign prostate hyperplasia. c-FLIP and HSP27 expression were observed by immunohistochemistry staining. Samples with less than 5% expression-positive cells were scored as 1, with 5%-50% were scored as 2, and with more than 50% were scored as 3. Local reactions were identified as 0.5 and evaluated.

Results

Both the presence of HSP27 within the tumor and the number of cancer cells positive for HSP27 were significantly correlated to GSS and pathologic stage (p<0.001, p=0.001, p<0.001, p<0.001). The same was true for c-FLIP expression (p<0.001). GSS was more highly correlated to HSP27 expression than to c-FLIP expression (r=0.814 for HSP27, r=0.776 for c-FLIP), as was pathologic stage (r=0.592 for HSP27, r=0.554 for c-FLIP).

Conclusions

In prostate cancer, higher GSS and a more advanced pathologic stage were associated with a higher likelihood of having a HSP27-positive tumor and more HSP27-positive tumor cells. HSP27 expression was correlated with GSS and prostate cancer stage. A more advanced pathologic stage corresponded to a higher likelihood of having a c-FLIP-positive tumor and more c-FLIP-positive tumor cells. HSP27 expression had a higher correlation with prostate cancer stage and GSS than c-FLIP expression did.

Circulating tumor cells exhibit a biologically aggressive cancer phenotype accompanied by selective resistance to chemotherapy

With prostate cancer (PCa), circulating tumor cells (CTCs) and disseminated tumor cells (DTCs) portend a poor clinical prognosis. Their unknown biology precludes rational therapeutic design. We demonstrate that CTC and DTC cell lines, established from mice bearing human PCa orthotopic implants, exhibit increased cellular invasion in vitro, increased metastasis in mice, and express increased epithelial to mesenchymal transition biomarkers. Further, they are selectively resistant to growth inhibition by mitoxantrone-like agents. These findings demonstrate that CTC formation is accompanied by phenotypic progression without obligate reversion. Their increased metastatic potential, selective therapeutic resistance, and differential expression of potential therapeutic targets provide a rational basis to test further interventions.

Biomarkers and personalized risk stratification for patients with clinically localized prostate cancer

Prostate cancer (PCa) is the most common neoplasia among men in developed countries and a leading cause of cancer-related morbidity and mortality. PCa is a very heterogeneous disease, both clinically and biologically. Currently, it is difficult to stratify patients into risk groups that entail different disease management. Therefore, a personalized view of this disease is mandatory, through the development of new and more accurate biomarkers that may help clinicians to stratify patients according to threat that PCa poses for each patient. Hence, this review focuses on recent developments of molecular and immunohistochemical biomarkers for PCa risk stratification that might enable a personalized approach to PCa patients. However, despite the increasing amount of available data, there is also an urgent need to translate the most promising biomarkers for clinical use through large multicenter validation trials. Ultimately, these will contribute for an improved clinical management of PCa patients.

Immunohistochemical expression of heat shock proteins, p63 and androgen receptor in benign prostatic hyperplasia and prostatic carcinoma in the dog

This study compared heat shock proteins Hsp60, Hsp72 and Hsp73, along with p63 and androgen receptor (AR) immunoexpression between 16 cases of benign prostatic hyperplasia (BPH) and 11 prostatic carcinomas (PCa) in dogs. The proportion of Hsp60-positive cells was higher in PCa compared with BPH (P = 0.033), whereas the frequency and intensity of Hsp73 immunostaining did not differ significantly between the two groups. Hsp72-immunostained nuclei formed a discontinuous layer along the basement membrane in BPH, whereas cells in this layer in PCa were negative or weakly positive. Hsp72 nuclear score showed significant positive associations with both p63 (P = 0.016) and AR (P = 0.009) scores. Double immunofluorescence revealed Hsp72-p63 and Hsp72-AR co-expressions in basal cell nuclei. Aberrant cytoplasmic p63 immunolabelling was observed in 3 of 11 PCa cases. These results suggest a role of the combined expression of Hsp72, p63 and AR in basal epithelial cells in canine BPH and PCa.

Mitogen-activated protein kinase kinase 4 (MAP2K4) promotes human prostate cancer metastasis

Prostate cancer (PCa) is the second leading cause of cancer death in the US. Death from PCa primarily results from metastasis. Mitogen-activated protein kinase kinase 4 (MAP2K4) is overexpressed in invasive PCa lesions in humans, and can be inhibited by small molecule therapeutics that demonstrate favorable activity in phase II studies. However, MAP2K4's role in regulating metastatic behavior is controversial and unknown. To investigate, we engineered human PCa cell lines which overexpress either wild type or constitutive active MAP2K4. Orthotopic implantation into mice demonstrated MAP2K4 increases formation of distant metastasis. Constitutive active MAP2K4, though not wild type, increases tumor size and circulating tumor cells in the blood and bone marrow. Complementary in vitro studies establish stable MAP2K4 overexpression promotes cell invasion, but does not affect cell growth or migration. MAP2K4 overexpression increases the expression of heat shock protein 27 (HSP27) protein and protease production, with the largest effect upon matrix metalloproteinase 2 (MMP-2), both in vitro and in mouse tumor samples. Further, MAP2K4-mediated increases in cell invasion are dependent upon heat shock protein 27 (HSP27) and MMP-2, but not upon MAP2K4's immediate downstream targets, p38 MAPK or JNK. We demonstrate that MAP2K4 increases human PCa metastasis, and prolonged over expression induces long term changes in cell signaling pathways leading to independence from p38 MAPK and JNK. These findings provide a mechanistic explanation for human studies linking increases in HSP27 and MMP-2 to progression to metastatic disease. MAP2K4 is validated as an important therapeutic target for inhibiting human PCa metastasis.

Circulating tumor cells exhibit a biologically aggressive cancer phenotype accompanied by selective resistance to chemotherapy

With prostate cancer (PCa), circulating tumor cells (CTCs) and disseminated tumor cells (DTCs) portend a poor clinical prognosis. Their unknown biology precludes rational therapeutic design. We demonstrate that CTC and DTC cell lines, established from mice bearing human PCa orthotopic implants, exhibit increased cellular invasion in vitro, increased metastasis in mice, and express increased epithelial to mesenchymal transition biomarkers. Further, they are selectively resistant to growth inhibition by mitoxantrone-like agents. These findings demonstrate that CTC formation is accompanied by phenotypic progression without obligate reversion. Their increased metastatic potential, selective therapeutic resistance, and differential expression of potential therapeutic targets provide a rational basis to test further interventions.

Roles of matrix metalloproteinases and their natural inhibitors in prostate cancer progression

Matrix metalloproteinases (MMPs), a group of zinc-dependent endopeptidases involved in the degradation of the extracellular matrix, play an important role in tissue remodeling associated with various physiological processes such as morphogenesis, angiogenesis, and tissue repair, as well as pathological processes including cirrhosis, arthritis and cancer. The MMPs are well established as mediators of tumor invasion and metastasis by breaking down connective tissue barriers. Although there has been a vast amount of literature on the role of MMPs in invasion, metastasis and angiogenesis of various cancers, the role of these endopeptidases in prostate cancer progression has not been systematically reviewed. This overview summarizes findings on the tissue and blood expression of MMPs, their function, regulation and prognostic implication in human prostate cancer, with a focus on MMP-2, -7, -9, MT1-MMP and tissue inhibitor of metalloproteinase 1 (TIMP-1). This review also summarizes the efficacy and failure of early-generation matrix metalloproteinase inhibitors (MMPIs) in the treatment of metastatic prostate cancer and highlights the lessons and challenges for next generation MMPIs.

Ki-67 is a strong prognostic marker of non-small cell lung cancer when tissue heterogeneity is considered

Background

Ki-67 expression is a well-established prognostic marker in various cancers. However, Ki-67 expression is also known as being heterogeneous. We investigated the prognostic significance of Ki-67 from the view of staining heterogeneity by the technique of Spiral Array.

Methods

100 cases of resected lung cancer from Toyama university hospital archive were collected. Spiral Array blocks were generated out of 100 cases using 100 μm thick paraffin sections. Four μm thick sections of the Array block were stained for Ki-67. Staining results in each reel were scored for areas with lowest (LS), highest (HS), and average (AS) expression, exclusively in the cancer cells. Heterogeneity score (HeS) was designed as the difference between HS and LS. The scores were divided into four grades (0–3). Clinical information was collected, and the prognostic significance of Ki-67 was analyzed.

Results

Pathological stage was available for 91 patients (43 stage IA, 22 stage IB, 2 stage IIA, 9 stage IIB, 13 stage IIIA, 1 stage IIIB, and 1 stage IV). The HS of Ki-67 score in non-small cell lung cancer was 3 in 17 cases, 2 in 27 cases, 1 in 28 cases, 0 in 21 cases, and 4 reels were lost. 78 cases had clinical follow up. 74 cases had all the information available and were analyzed for correlation between Ki-67 expression and survival. Cases with score 2 and 3 of HS and HeS showed significant poorer prognosis (both P < 0.001), whereas LS or AS did not show significance. The results were identical when analyzing adenocarcinoma and squamous cell carcinoma, separately. Cox multivariate analysis of Ki-67 showed that HS was an independent risk factor affecting overall survival.

Conclusions

Ki-67 is a strong prognostic marker for non-small cell lung cancer when the degree of highest staining frequency or heterogeneity is considered.

Expression of heat shock protein 27 in prostate cancer cell lines according to the extent of malignancy and doxazosin treatment

Purpose

Heat shock protein 27 (HSP27) is known as the material that plays a role in apoptosis control in tumor and cell protection including the immune response, drug tolerance, and so on. In this study, HSP27 expression according to the prostate cancer malignancy level was evaluated, and HSP27 expression was also analyzed after inducing apoptosis by doxazosin treatment of the prostate cancer cell lines.

Materials and Methods

Reverse transcription polymerase chain reaction (RT-PCR) and immunofluorescence staining of the HSP27 was implemented by the culture of RWPE-1, LNCaP, androgen-independent human prostate cancer cells (PC-3), and TSU-Pr1 cell lines. Analysis was separately conducted in the control group, control vector group treated by dimethyl sulfoxide, and groups treated with 10 µM or 25 µM doxazosin. The expression of HSP27 in RT-PCR and immunofluorescence staining was observed and evaluated after conversion to numerical values.

Results

In the RT-PCR results, depending on the cell type, LNCaP, TSU-Pr1 showed the highest HSP27 expression followed by PC-3, LNCaP and RWPE-1 in sequence. After doxazosin treatment, the expression detected by RT-PCR was stronger at a 25-µM doxazosin concentration compared to that at a 10-µM concentration, and the result was similar by immunofluorescence staining.

Conclusions

HSP27 expression increased depending on the prostate cancer cell line. This meant that HSP27 expression was related to the prostate cancer malignancy level. Additionally, the higher the treatment concentration in PC-3 was, the higher the HSP27 expression was. This result showed that doxazosin induced apoptosis of prostate cancer.

Application of a new technique, spiral tissue microarrays constructed using needle biopsy specimens, to prostate cancer research

Tissue microarrays were constructed using prostate needle biopsy specimens obtained from 58 patients who underwent radical prostatectomy for localized or locally advanced prostate cancer (PC). We used the spiral array (SA) technique, a novel approach for tissue array construction in a spiral form, which has advantages over small needle biopsy specimens. Roll-shaped tissue pieces produced by slicing a prostate biopsy tissue block and trimming the cancer segment were used to obtain a tissue array block. Cancer segments measuring >3 mm were incorporated into the tissue arrays. Cancer fragments (n=253) were obtained from formalin-fixed, paraffin-embedded needle biopsy specimens. The median number of cancer fragments per patient was four (1-8, min-max). On SA, the median number of confirmed cancer fragments per patient was four (1-7) and 224 cancer fragments (88.5%) were confirmed histologically. Each core of reeled tissue contained at least one cancer fragment. The expressions of multiple prognostic molecular markers for PC (Ki-67, p53 and bcl-2) were immunohistochemically measured using the SA. The Ki-67 and bcl-2 expressions were significantly associated with the Gleason score (GS). A univariate analysis identified Ki-67, bcl-2 and GS as significant predictors of cancer-specific survival, p53 and bcl-2 as significant predictors of overall survival and Ki-67, adjuvant androgen deprivation and GS as significant predictors of biochemical progression. In a multivariate analysis, p53 was independently associated with overall survival, while adjuvant androgen deprivation and GS were associated with biochemical progression. These results indicate that SA has potential as a new tool for translational research on PC.

Initial biopsy Gleason score as a predictive marker for survival benefit in patients with castration-resistant prostate cancer treated with docetaxel: data from the TAX327 study

BACKGROUND

Since 2004, docetaxel has been the standard first-line systemic therapy for patients with metastatic castration-resistant prostate cancer (mCRPC). With abiraterone recently becoming available in the predocetaxel setting, it is warranted to identify subgroups of patients who may obtain the greatest benefit from docetaxel and particularly qualify for receiving docetaxel as first-line treatment for mCRPC.

OBJECTIVE

We aimed to identify factors that could characterize subgroups of patients who obtain the greatest benefit from the use of docetaxel.

DESIGN, SETTING, AND PARTICIPANTS

TAX327 was multinational, randomized, phase 3 study that was conducted from 2000 to 2002 in 1006 men with mCRPC.

INTERVENTION

Patients were randomized to receive docetaxel every 3 wk (D3), weekly docetaxel (D1), or mitoxantrone every 3 wk (M3), each with prednisone.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

We investigated whether patients with poorly differentiated tumors (Gleason score ≥7) at diagnosis had greater benefit from D3 compared with M3 than patients with better differentiated tumors (Gleason score ≤6). Using a Cox model, we compared overall survival (OS) between the treatment groups within each subgroup of Gleason score.

RESULTS AND LIMITATIONS

The TAX 327 data showed that the OS benefit of D3 versus M3 was greater in patients with high-grade tumors (median OS: 18.9 vs 14.5 mo; p=0.009) than in patients with low-grade tumors (median OS: 21.6 vs 20.7 mo; p=0.674). Limitations of a retrospective analysis apply.

CONCLUSIONS

The survival benefit obtained with docetaxel is most pronounced in patients with high-Gleason-score tumors (Gleason ≥7). In a time of shifting paradigms in mCRPC, with abiraterone becoming available prior to docetaxel chemotherapy, Gleason score may help in selecting patients who obtain the greatest benefit from docetaxel as first-line treatment for mCRPC. Prospective validation of these findings is warranted.

Underexpression of MMP-2 and its regulators, TIMP2, MT1-MMP and IL-8, is associated with prostate cancer

OBJECTIVE

Extracellular matrix homeostasis is strictly maintained by a coordinated balance between the expression of metalloproteinases (MMPs) and their regulators. The purpose of this study was to investigate whether MMP-2 and its specifi c regulators, TIMP-2, MT1-MMP and IL-8, are expressed in a reproducible, specific pattern and if the profiles are related to prognosis and clinical outcome of prostate cancer (PCa).

MATERIALS AND METHODS

MMP-2, TIMP-2, MT1-MMP and IL-8 expression levels were analyzed by quantitative real-time polymerase chain reaction (qRT-PCR) in freshly frozen malignant and benign tissue specimens collected from 79 patients with clinically localized PCa who underwent radical prostatectomies. The control group consisted of 11 patients with benign prostate hyperplasia (BPH). The expression profile of the MMP-2 and its regulators were compared using Gleason scores, pathological stage, pre-operative PSA levels and the fi nal outcome of the PCa.

RESULTS

The analysis of 79 specimens of PCa revealed that MMP-2, TIMP-2, MT1-MMP and IL-8 were underexpressed at 60.0%, 72.2%, 62.0% and 65.8%, respectively, in malignant prostatic tissue in relation to BPH samples. Considering the prognostic parameters, we demonstrated that high Gleason score tumors (≥ 7) overexpressed MMP-2 (p = 0.048) and TIMP-2 (p = 0.021), compared to low Gleason score tumors (< 7).

CONCLUSION

We have demonstrated that MMP-2 and its regulators are underexpressed in PCa. Alternatively, overexpression of MMP-2 and TIMP-2 was related to higher Gleason score tumors. We postulate that alterations in metalloproteinase expression may be important in the control of tissue homeostasis related to prostate carcinogenesis and tumor behavior.

Expression of MMP-1, MMP-9 and TIMP-2 in prostate carcinoma and their influence on prognosis and survival

PURPOSE

Matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs) participate in tumorigenesis, and their association with disease outcome is highly controversial. The present study investigates the influence of MMP-1, MMP-9 and TIMP-2 on different clinicopathologic variables and disease-free survival (DFS) of patients with prostate carcinoma.

METHODS

Hundred and forty-five cases are included in the study, and levels of MMP/TIMP expressions are assessed in three tissue compartments (i.e., tumor, stroma and normal glands) with immunohistochemistry.

RESULTS

Matrix metalloproteinase-1 expression in tumor cells was associated with lower Gleason scores, pretreatment prostate-specific antigen levels and lower incidence of vascular, perineural and extracapsular invasions. Moreover, MMP-9 positivity and TIMP-2 expression in normal glands were correlated with lower Gleason patterns and early stage at presentation. Expression of MMP in tumor cells and the presence of TIMP-2 in normal glands were associated with better DFS.

CONCLUSION

Variability of MMP/TIMP expressions from case to case makes it difficult to evaluate their impact on clinical outcome. However, these proteins might be new and promising targets for prostate cancer therapy in the future.

Matrix metalloproteinases in cancer: their value as diagnostic and prognostic markers and therapeutic targets

Biomarkers are used as tools in cancer diagnostics and in treatment stratification. In most cancers, there are increased levels of one or several members of the matrix metalloproteinases (MMPs). This is a family of proteolytic enzymes that are involved in many phases of cancer progression, including angiogenesis, invasiveness, and metastasis. It has therefore been expected that MMPs could serve as both diagnostic and prognostic markers in cancer patients, but despite a huge number of studies, it has been difficult to establish MMPs as cancer biomarkers. In the present paper, we assess some of the challenges associated with MMP research as well as putative reasons for the conflicting data on the value of these enzymes as diagnostic and prognostic markers in cancer patients. We also review the prognostic value of a number of MMPs in patients with lung, colorectal, breast, and prostate cancers. The review also discusses MMPs as potential target molecules for therapeutic agents and new strategies for development of such drugs.

Quantitative proteomic determination of diethylstilbestrol action on prostate cancer

Diethylstilbestrol (DES) has a direct cellular mechanism inhibition on prostate cancer. Its action is independent from the oestrogen receptors and is preserved after a first-line hormonal therapy. We aimed to identify proteins involved in the direct cellular inhibition effects of DES on prostate cancer. We used a clonogenic assay to establish the median lethal concentration of DES on 22RV1 cells. 22RV1 cells were exposed to standard and DES-enriched medium. After extraction, protein expression levels were obtained by two-dimensional differential in-gel electrophoresis (2D-DIGE) and isotope labelling tags for relative and absolute quantification (iTRAQ). Proteins of interest were analysed by quantitative RT-PCR and western blotting. The differentially regulated proteins (P<0.01) were interrogated against a global molecular network based on the ingenuity knowledge base. The 2D-DIGE analyses revealed DES-induced expression changes for 14 proteins (>1.3 fold; P<0.05). The iTRAQ analyses allowed the identification of 895 proteins. Among these proteins, 65 had a modified expression due to DES exposure (i.e., 23 overexpressed and 42 underexpressed). Most of these proteins were implicated in apoptosis and redox processes and had a predicted mitochondrial expression. Additionally, ingenuity pathway analysis placed the OAT and HSBP1 genes at the centre of a highly significant network. RT-PCR confirmed the overexpression of OAT (P=0.006) and HSPB1 (P=0.046).

The role of treatment modality on the utility of predictive tissue biomarkers in clinical prostate cancer: a systematic review

BACKGROUND

Tissue biomarkers could pivotally improve clinical outcome prediction following prostate cancer therapy. Clinically, prostate cancer is managed by diverse treatment modalities whose individual influence on a biomarker's predictive ability is not well understood and poorly investigated in the literature.

OBJECTIVE

We conducted a systematic review to assess the predictive value of biomarkers in different treatment contexts in prostate cancer.

STUDY METHODOLOGY

A literature search was performed using the MeSH headings "prostate neoplasms" and "biological markers". Rigorous selection criteria identified studies correlating expression with clinical outcomes from primary androgen deprivation therapy (ADT), radical prostatectomy and radiotherapy (± neoadjuvant ADT).

STUDY RESULTS

Of 10,668 studies identified, 481 papers matched initial inclusion criteria. Following rescreening, 384 studies identified 236 individual tissue biomarkers, of which 29 were predictive on multivariate analysis in at least 2 independent cohorts. The majority were only tested in surgical cohorts. Only 8 predictive biomarkers were tested across all 3 treatments with Ki67 identified as universal predictive marker. p16 showed potential for treatment stratification between surgery and radiotherapy but needs further validation in independent studies.

CONCLUSIONS

Despite years of research, very few tissue biomarkers retain predictive value in independent validation across therapy context. Currently, none have conclusive ability to help treatment selection. Future biomarker research should consider the therapy context and use uniform methodology and evaluation criteria.

Association between DNA methylation of HSPB1 and death in low Gleason score prostate cancer

Background:

Heat shock protein 27 (Hsp-27) encoded by gene HSPB1 is a critical regulator of the behavioral phenotype of human prostate cancer (PCa) cells, enhanced expression being associated with highly aggressive disease and poor clinical outcome. In contrast, the protein is not expressed in PCas of low malignant potential. To gain insight into the mechanism regulating its expression, we tested the hypothesis that differential methylation of CpG islands within HSPB1 controls transcription and subsequent translation of the gene.

Methods:

We studied prostate epithelial cell lines and tissue biopsies, including 59 BPH and 415 PCas, of which 367 were a cohort of men with up to 20 years of follow-up. Methylation across the gene (DNA methylation (DNAme)) was assayed by pyrosequencing. Hsp-27 expression was assessed by western blot and immunohistochemistry.

Results:

In cancer tissues, methylation increased in a 3′ direction (P<0.0001) whereas in benign hyperplasia methylation was constantly below 5%, a cutoff giving a specificity of 100% and sensitivity of 50%. Although methylation of the promoter region was significantly discriminating between benign and malignant prostatic epithelia, it compared poorly with methylation of the first intron. The prognostic value of HSPB1 DNAme was confirmed by both univariate (hazard ratio 1.77 per 50% increment, P=0.02) and multivariate models. Interaction between HSPB1 methylation and Gleason score revealed high DNAme to be a reliable prognostic marker of poor outcome in men with low Gleason score (P=0.014).

Conclusions:

Our data indicate CpG methylation of the first HSPB1 intron to be an important biomarker that identifies aggressive PCas otherwise regarded as low risk by current clinical criteria but that, biologically, require immediate active management.

Prognostic significance of primary Gleason pattern in Japanese men with Gleason score 7 prostate cancer treated with radical prostatectomy

OBJECTIVES

To evaluate the significance of the primary Gleason pattern in patients with Gleason score (GS) 7 prostate cancer treated with radical prostatectomy.

MATERIALS AND METHODS

This study included 959 consecutive Japanese men who underwent radical prostatectomy without neoadjuvant therapies and were subsequently diagnosed as having GS 7 prostate cancer based on the modified International Society of Urological Pathology (ISUP) 2005 Gleason grading system.

RESULTS

Of these 959 patients, 666 (69.4%) and 293 (30.6%) had GS 3+4 and GS 4+3 tumors, respectively. There were significant differences in the prostate-specific antigen (PSA) level, biopsy GS, pathologic T stage, lymphatic invasion, microvenous invasion, and perineural invasion between these 2 groups. During the mean observation of 48.9 months, biochemical recurrence occurred in 211 patients (22.0%), and there was a significant difference in the biochemical recurrence-free survival between patients with GS 3+4 tumors and those with GS 4+3 tumors. Of several factors examined, biochemical recurrence-free survival was significantly associated with the PSA level, biopsy Gleason score, capsular penetration, seminal vesicle invasion, surgical margin status, lymphatic invasion, microvenous invasion, perineural invasion, and primary Gleason pattern, among which the PSA level, capsular penetration, seminal vesicle invasion, and surgical margin status, but not primary Gleason pattern, appeared to be independent predictors of biochemical recurrence.

CONCLUSIONS

Despite the lack of an independent significance, primary Gleason pattern based on the modified ISUP 2005 Gleason grading system is shown to be significantly associated with the biochemical outcome of Japanese men with GS 7 prostate cancer.

Immunohistochemical expression of minichromosome maintenance complex protein 2 predicts biochemical recurrence in prostate cancer: a tissue microarray and digital imaging analysis-based study of 428 cases

Prostate cancer remains a major health problem in the United States. Established clinicopathologic parameters such as Gleason score, T stage, and prostate-specific antigen levels are currently the guiding tools for prognostication and disease management. The addition of biomarkers could increase the accuracy of these parameters for predicting disease progression, response to therapy, and survival. In this regard, the goal of this study was to evaluate minichromosome maintenance complex protein 2 and Ki-67 immunohistochemical expression as predictors of outcome in prostate cancer. For this purpose, 11 tissue microarrays were constructed using tumor and nontumor samples from 428 patients. Patients were divided into short-term (mean, 2.9 years) and long-term (mean, 14.1 years) follow-up groups. End points were biochemical recurrence for the short-term follow-up group and prostate cancer-related death for the long-term follow-up group. All men in the long-term follow-up group had biochemical recurrence at the time of recruitment. Expression of both markers was higher in tumor than in nontumor glands. Percentage of minichromosome maintenance complex protein 2 was associated with Gleason score in both groups. Percentage of Ki-67 was associated with Gleason score and pathologic stage only in the short-term follow-up group. Higher minichromosome maintenance complex protein 2 percentages were associated with biochemical recurrence in the short-term follow-up group. In the long-term follow-up group, neither minichromosome maintenance complex protein 2 nor Ki-67 levels predicted prostate cancer death. In conclusion, our results suggest that in patients treated by radical prostatectomy for clinically localized prostate cancer, immunohistochemistry for minichromosome maintenance complex protein 2 expression could be used to predict biochemical recurrence, independent of other known clinicopathologic factors.

Heat shock proteins as danger signals for cancer detection

First discovered in 1962, heat shock proteins (HSPs) are highly studied with about 35,500 publications on the subject to date. HSPs are highly conserved, function as molecular chaperones for a large panel of “client” proteins and have strong cytoprotective properties. Induced by many different stress signals, they promote cell survival in adverse conditions. Therefore, their roles have been investigated in several conditions and pathologies where HSPs accumulate, such as in cancer. Among the diverse mammalian HSPs, some members share several features that may qualify them as cancer biomarkers. This review focuses mainly on three inducible HSPs: HSP27, HPS70, and HSP90. Our survey of recent literature highlights some recurring weaknesses in studies of the HSPs, but also identifies findings that indicate that some HSPs have potential as cancer biomarkers for successful clinical applications.

Substitution at carbon 2 of 19-nor-1α,25-dihydroxyvitamin D3 with 3-hydroxypropyl group generates an analogue with enhanced chemotherapeutic potency in PC-3 prostate cancer cells

The active form of vitamin D(3), 1α,25-dihydroxyvitamin D(3)(1α,25(OH)(2)D(3)), has anti-proliferative and anti-invasive activities in prostate cancer cells. Because of 1α,25(OH)(2)D(3) therapeutic potential in treating cancers, numerous analogues have been synthesized with an attempt to increase anti-proliferative and/or decrease calcemic properties. Among these analogues, 19-nor-1α,25(OH)(2)D(2) while being less calcemic has equivalent potency as 1α,25(OH)(2)D(3) in several in vitro and in vivo systems. We recently showed that 19-nor-2α-(3-hydroxypropyl)-1α,25(OH)(2)D(3) (MART-10) was at least 500-fold and 10-fold more active than 1α,25(OH)(2)D(3) in inhibiting the proliferation of an immortalized normal prostate PZ-HPV-7 cells and the invasion of androgen insensitive PC-3 prostate cancer cells, respectively. In this study, we further investigated the effects of MART-10 and 1α,25(OH)(2)D(3) on the dose- and time-dependent induction of CYP24A1 gene expression in PC-3 prostate cancer cells. We found that MART-10 induced CYP24A1 gene expression at a lower concentration with a longer duration compared to 1α,25(OH)(2)D(3), suggesting that MART-10 is less susceptible to CYP24A1 degradation. Molecular docking model of human CYP24A1 and MART-10 indicates that its side chain is far away from the heme ion and is less likely to be hydroxylated by the enzyme. Furthermore, MART-10 was a more potent inhibitor of PC-3 cell proliferation and invasion compared to 1α,25(OH)(2)D(3). In addition, MART-10 down-regulated matrix metalloproteinase-9 (MMP-9) expression which could be one mechanism whereby MART-10 influences cancer cell invasion. Finally, we observed that subcutaneous administration of MART-10 up-regulated the CYP24A1 mRNA expression in rat kidneys without affecting their plasma calcium levels. Thus, our findings demonstrate that MART-10 is biologically active in vivo and may be an effective vitamin D analogue for clinical trials to treat prostate cancer.

Using molecular markers to help predict who will fail after radical prostatectomy

Recent phase III trial data clearly demonstrate that adjuvant therapy can reduce recurrence and increase survival after prostatectomy for prostate cancer. There is great interest in being able to accurately predict who is at risk of failure to avoid treating those who may not benefit. The standard markers consisting of prostate specific antigen (PSA), Gleason score, and pathological stage are not very specific, so there is an unmet need for other markers to aid in prognostic stratification. Numerous studies have been conducted with various markers and more recently gene signatures, but it is unclear whether any of them are really useful. We conducted a comprehensive review of the literature to determine the current status of molecular markers in predicting outcome after radical prostatectomy.

Prognostic prediction in patients with metastatic renal cell carcinoma treated with sorafenib based on expression levels of potential molecular markers in radical nephrectomy specimens

OBJECTIVES

To investigate the expression levels of multiple molecular markers in radical nephrectomy specimens from patients with metastatic renal cell carcinoma (RCC) treated with sorafenib in order to identify factors predicting susceptibility to this agent.

MATERIALS AND METHODS

This study included 45 consecutive patients undergoing radical nephrectomy for clear cell RCC who were diagnosed as having metastatic diseases refractory to cytokine therapy and subsequently treated with sorafenib. Expression levels of 19 molecular markers involved in the regulation of apoptosis, cell cycle, signal transduction, and angiogenesis in primary RCC specimens were measured by immunohistochemical staining.

RESULTS

There was no molecular marker having significant impact on the prediction of response to sorafenib. However, progression-free survival (PFS) was significantly associated with the expression levels of Bcl-xL and platelet-derived growth factor receptor (PDGFR)-α in addition to the presence of bone metastasis and C-reactive protein level on univariate analysis. Of these significant factors, PDGFR-α expression and the presence of bone metastasis appeared to be independently related to PFS by multivariate analysis. Furthermore, there were significant differences in PFS according to positive numbers of these 2 independent risk factors; that is, disease progression occurred in 2 of 7 patients who were negative for risk factor, 19 of 34 positive for a single risk factor, and 6 of 6 positive for both risk factors.

CONCLUSIONS

Collectively, these findings suggest that it would be useful to consider expression levels of potential molecular markers, particularly PDGFR-α, as well as clinical parameters to select metastatic RCC patients likely to benefit from treatment with sorafenib.