Hsp-27 expression at diagnosis predicts poor clinical outcome in prostate cancer independent of ETS-gene rearrangement. Br J Cancer. 2009;101:1137-1144. [PMID: 19707199 DOI: 10.1038/sj.bjc.6605227]

Targeting the heat shock response induced by modulated electro-hyperthermia (mEHT) in cancer

The Heat Shock Response (HSR) is a cellular stress reaction crucial for cell survival against stressors, including heat, in both healthy and cancer cells. Modulated electro-hyperthermia (mEHT) is an emerging non-invasive cancer therapy utilizing electromagnetic fields to selectively target cancer cells via temperature-dependent and independent mechanisms. However, mEHT triggers HSR in treated cells. Despite demonstrated efficacy in cancer treatment, understanding the underlying molecular mechanisms for improved therapeutic outcomes remains a focus. This review examines the HSR induced by mEHT in cancer cells, discussing potential strategies to modulate it for enhanced tumor-killing effects. Approaches such as HSF1 gene-knockdown and small molecule inhibitors like KRIBB11 are explored to downregulate the HSR and augment tumor destruction. We emphasize the impact of HSR inhibition on cancer cell viability, mEHT sensitivity, and potential synergistic effects, addressing challenges and future directions. This understanding offers opportunities for optimizing treatment strategies and advancing precision medicine in cancer therapy.

Exploiting Interdata Relationships in Prostate Cancer Proteomes: Clinical Significance of HO-1 Interactors

Prostate cancer (PCa) cells display abnormal expression of proteins resulting in an augmented capacity to resist chemotherapy and colonize distant organs. We have previously shown the anti-tumoral role of heme oxygenase 1 (HO-1) in this disease. In this work, we undertook a mass spectrometry-based proteomics study to identify HO-1 molecular interactors that might collaborate with its modulatory function in PCa. Among the HO-1 interactors, we identified proteins with nuclear localization. Correlation analyses, using the PCa GSE70770 dataset, showed a significant and positive correlation between HMOX1 and 6 of those genes. Alternatively, HMOX1 and YWHAZ showed a negative correlation. Univariable analyses evidenced that high expression of HNRNPA2B1, HSPB1, NPM1, DDB1, HMGA1, ZC3HAV1, and HMOX1 was associated with increased relapse-free survival (RFS) in PCa patients. Further, PCa patients with high HSPB1/HMOX1, DDB1/HMOX1, and YWHAZ/HMOX1 showed a worse RFS compared with patients with lower ratios. Moreover, a decrease in RFS for patients with higher scores of this signature was observed using a prognostic risk score model. However, the only factor significantly associated with a higher risk of relapse was high YWHAZ. Multivariable analyses confirmed HSPB1, DDB1, and YWHAZ independence from PCa clinic-pathological parameters. In parallel, co-immunoprecipitation analysis in PCa cells ascertained HO-1/14-3-3ζ/δ (protein encoded by YWHAZ) interaction. Herein, we describe a novel protein interaction between HO-1 and 14-3-3ζ/δ in PCa and highlight these factors as potential therapeutic targets.

Overcoming prostate cancer drug resistance with a novel organosilicon small molecule

A major challenge to the treatment of advanced prostate cancer (PCa) is the development of resistance to androgen-deprivation therapy (ADT) and chemotherapy. It is imperative to discover effective therapies to overcome drug resistance and improve clinical outcomes. We have developed a novel class of silicon-containing compounds and evaluated the anticancer activities and mechanism of action using cellular and animal models of drug-resistant PCa. Five organosilicon compounds were evaluated for their anticancer activities in the NCI-60 panel and established drug-resistant PCa cell lines. GH1504 exhibited potent in vitro cytotoxicity in a broad spectrum of human cancer cells, including PCa cells refractory to ADT and chemotherapy. Molecular studies identified several potential targets of GH1504, most notably androgen receptor (AR), AR variant 7 (AR-v7) and survivin. Mechanistically, GH1504 may promote the protein turnover of AR, AR-v7 and survivin, thereby inducing apoptosis in ADT-resistant and chemoresistant PCa cells. Animal studies demonstrated that GH1504 effectively inhibited the in vivo growth of ADT-resistant CWR22Rv1 and chemoresistant C4-2B-TaxR xenografts in subcutaneous and intraosseous models. These preclinical results indicated that GH1504 is a promising lead that can be further developed as a novel therapy for drug-resistant PCa.

Lumefantrine, an antimalarial drug, reverses radiation and temozolomide resistance in glioblastoma

Glioblastoma multiforme (GBM) is an aggressive cancer without currently effective therapies. Radiation and temozolomide (radio/TMZ) resistance are major contributors to cancer recurrence and failed GBM therapy. Heat shock proteins (HSPs), through regulation of extracellular matrix (ECM) remodeling and epithelial mesenchymal transition (EMT), provide mechanistic pathways contributing to the development of GBM and radio/TMZ-resistant GBM. The Friend leukemia integration 1 (Fli-1) signaling network has been implicated in oncogenesis in GBM, making it an appealing target for advancing novel therapeutics. Fli-1 is linked to oncogenic transformation with up-regulation in radio/TMZ-resistant GBM, transcriptionally regulating HSPB1. This link led us to search for targeted molecules that inhibit Fli-1. Expression screening for Fli-1 inhibitors identified lumefantrine, an antimalarial drug, as a probable Fli-1 inhibitor. Docking and isothermal calorimetry titration confirmed interaction between lumefantrine and Fli-1. Lumefantrine promoted growth suppression and apoptosis in vitro in parental and radio/TMZ-resistant GBM and inhibited tumor growth without toxicity in vivo in U87MG GBM and radio/TMZ-resistant GBM orthotopic tumor models. These data reveal that lumefantrine, an FDA-approved drug, represents a potential GBM therapeutic that functions through inhibition of the Fli-1/HSPB1/EMT/ECM remodeling protein networks.

Transcriptional regulation of HSPB1 by Friend leukemia integration-1 factor modulates radiation and temozolomide resistance in glioblastoma

Glioblastoma (GBM) is the most common primary brain tumor and is invariably fatal. Heat shock proteins (HSPs) provide protein signatures/biomarkers for GBM that afford potential as targets for developing anti-GBM drugs. In GBM, elevated expression of hypoxia inducible factors under the influence of Ets family proteins significantly promotes the expression of HSPs. RNAseq analysis identified HSPB1 as a prominent upregulated HSP in GBM and in radiation resistant/temozolomide resistant (radio/TMZR) GBM. Here, we established friend leukemia integration 1 (Fli-1), a member of Ets family to be playing a transcriptional regulatory role on the HSPB1 gene. Fli-1 binds to nucleotide residues GGAA at binding sites 3, 6 and 7 in the 5-kb upstream region of HSPB1. Fli-1 has been linked to oncogenic transformation with upregulation in radio/TMZR GBM. Overexpression of Fli-1 in GBM promotes resistance, whereas Fli-1 knockdown in radio/TMZR GBM cells suppresses resistance. We identify the underlying molecular mechanisms of Fli-1-mediated regulation of HSPB1 that drive extracellular matrix remodeling and epithelial to mesenchymal transition in radio/TMZR GBM cells. This study uncovers Fli-1 as a potential therapeutic target for combating radiation and temozolomide resistance in GBM.

Melanoma migration is promoted by prion protein via Akt-hsp27 signaling axis

Patients with metastatic melanoma have a poorer prognosis. Prion protein (PrP) in melanoma is known to play an important role in cancer cell migration and invasion by interacting with filamin A (FLNa), a cytolinker protein. To investigate if PrP may contribute to cancer cell mobility independent of its binding to FLNa, we knocked out PRNP in M2 melanoma cell, which lacked FLNa expression. We found that deletion of PRNP in M2 significantly reduced its motility. When PRNP was deleted, the level of Akt was decreased. As a consequence, phosphorylation of small heat shock protein (hsp27) was also reduced, which resulted in polymerization of F-actin rendering the cells less migratory. Accordingly, when PrP was re-expressed in PRNP null M2 cells, the mobility of the recurred cells was rescued, so were the expression levels of Akt and phosphorylated hsp27, resulting in a decrease in the polymerization of F-actin. These results revealed that PrP can play a FLNa independent role in cytoskeletal organization and tumor cell migration by modulating Akt-hsp27-F-actin axis.

The Multiple Roles and Therapeutic Potential of Molecular Chaperones in Prostate Cancer

Prostate cancer (PCa) is one of the most common cancer types in men worldwide. Heat shock proteins (HSPs) are molecular chaperones that are widely implicated in the pathogenesis, diagnosis, prognosis, and treatment of many cancers. The role of HSPs in PCa is complex and their expression has been linked to the progression and aggressiveness of the tumor. Prominent chaperones, including HSP90 and HSP70, are involved in the folding and trafficking of critical cancer-related proteins. Other members of HSPs, including HSP27 and HSP60, have been considered as promising biomarkers, similar to prostate-specific membrane antigen (PSMA), for PCa screening in order to evaluate and monitor the progression or recurrence of the disease. Moreover, expression level of chaperones like clusterin has been shown to correlate directly with the prostate tumor grade. Hence, targeting HSPs in PCa has been suggested as a promising strategy for cancer therapy. In the current review, we discuss the functions as well as the role of HSPs in PCa progression and further evaluate the approach of inhibiting HSPs as a cancer treatment strategy.

The Contribution of Fluoride to the Pathogenesis of Eye Diseases: Molecular Mechanisms and Implications for Public Health

This study provides diverse lines of evidence demonstrating that fluoride (F) exposure contributes to degenerative eye diseases by stimulating or inhibiting biological pathways associated with the pathogenesis of cataract, age-related macular degeneration and glaucoma. As elucidated in this study, F exerts this effect by inhibiting enolase, τ-crystallin, Hsp40, Na⁺, K⁺-ATPase, Nrf2, γ -GCS, HO-1 Bcl-2, FoxO1, SOD, PON-1 and glutathione activity, and upregulating NF-κB, IL-6, AGEs, HsP27 and Hsp70 expression. Moreover, F exposure leads to enhanced oxidative stress and impaired antioxidant activity. Based on the evidence presented in this study, it can be concluded that F exposure may be added to the list of identifiable risk factors associated with pathogenesis of degenerative eye diseases. The broader impact of these findings suggests that reducing F intake may lead to an overall reduction in the modifiable risk factors associated with degenerative eye diseases. Further studies are required to examine this association and determine differences in prevalence rates amongst fluoridated and non-fluoridated communities, taking into consideration other dietary sources of F such as tea. Finally, the findings of this study elucidate molecular pathways associated with F exposure that may suggest a possible association between F exposure and other inflammatory diseases. Further studies are also warranted to examine these associations.

Differential expression of Annexin 2, SPINK1, and Hsp60 predict progression of prostate cancer through bifurcated WHO Gleason score categories in African American men

BACKGROUND

Although studies have observed several markers correlate with progression of prostate cancer (PCa), no specific markers have been identified that accurately predict the progression of this disease, even in African American (AA) men who are generally at higher risk than other ethnic groups. The primary goal of this study was to explore whether three markers could predict the progression of PCa.

METHOD

We investigated protein expression of Annexin 2 (ANX2), serine peptidase inhibitor, kazal type 1(SPINK1)/tumor-associated trypsin inhibitor (TATI), and heat shock protein 60 (Hsp60) in 79 archival human prostate trans-rectal ultrasound (TRUS) biopsy tissues according to a modified World Health Organization (WHO) classification: normal (WHO1a), Gleason Score (GS6 (WHO1b), GS7 subgroups (WHO2 = 3 + 4, WHO3 = 4 + 3), GS8 (WHO4), and GS9-10 (WHO5). AA men aged 41-90 diagnosed from 1990 to 2013 at Howard University were included. Automated staining assessed expression of each biomarker. Spearman correlation assessed the direction and relationship between biomarkers, WHO and modified WHO GS, age, and 5-year survival. A two-tailed t-test and ANOVA evaluated biomarkers expression in relationship to WHO normal and other GS levels, and between WHO GS levels. A logistic and linear regression analysis examined the relationship between biomarker score and WHO GS categories. Kaplan-Meier curves graphed survival.

RESULTS

ANX2 expression decreased monotonically with the progression of PCa while expression of SPINK1/TATI and Hsp60 increased but had a more WHO GS-specific effect; SPINK1/TATI differed between normal and GS 2-6 and HSP60 differed between GS 7 and GS 2-6. WHO GS was found to be significantly and negatively associated with ANX2, and positively with SPINK1/TATI and Hsp60 expression. High SPINK1/TATI expression together with the low ANX2 expression at higher GS exhibited a bi-directional relationship that is associated with PCa progression and survival.

CONCLUSION

Importantly, the data reveal that ANX2, and SPINK1/TAT1 highly associate with WHO GS and with the transition from one stage of PrCa to the next in AA men. Future research is needed in biracial and larger population studies to confirm this dynamic relationship between ANX2 and SPINK1 as independent predictors of PCa progression in all men.

Expression Profiling of Hspb1 and Tp53 Genes through RT-qPCR in Different Cancer Types of Canis familiaris

Background: Diagnostic molecular marker studies are in vogue to have insight of most prevalent animal diseases including cancer. Objectives: Gene expression profiling of pro and anti-apoptotic genes was conducted in dog Lymphoma, CTVT, SCC, granuloma, perianal adenocarcinoma and mammary tumors. Materials and Methods: Cancerous tissues of 21 affected animals were obtained. Total RNA was extracted followed by cDNA synthesis. Comparative Ct method via Taqman assay (RT-qPCR) was used to quantify corresponding mRNA molecules, Tp53 and Hspb1, as normalized by GAPDH as the reference gene . Results:Hspb1 showed ectopic expression in lymphoma, CTVT and mammary tumors; its down-regulation was observed in granuloma and oral SCC with fold difference (FD) of ±35. Similarly, Tp53 as the tumor suppressor gene with pro-apoptotic properties, showed up-regulation in all tumor types, notably 80% of mammary tumors and 60% of CTVT. The FD values were 33.31 and 2.27, respectively. Conclusion: Altered transcriptomic response of Hspb1 and Tp53 was observed in all cancer types of Canis familiaris. The resulting profile depicts the involvement of the genes in cancer pathways. Thus, the data might be helpful for diagnosis, prognosis, identification and classification of these widespread neoplasms in this species.

Epithelial-mesenchymal transition in prostate cancer: an overview

Prostate cancer is a main urological disease associated with significant morbidity and mortality. Radical prostatectomy and radiotherapy are potentially curative for localized prostate cancer, while androgen deprivation therapy is the initial systemic therapy for metastatic prostate disease. However, despite temporary response, most patients relapse and evolve into castration resistant cancer.

Epithelial-mesenchymal transition (EMT) is a complex gradual process that occurs during embryonic development and/or tumor progression. During this process, cells lose their epithelial characteristics and acquire mesenchymal features. Increasing evidences indicate that EMT promotes prostate cancer metastatic progression and it is closely correlated with increased stemness and drug resistance.

In this review, we discuss the main molecular events that directly or indirectly govern the EMT program in prostate cancer, in order to better define the role and the mechanisms underlying this process in prostate cancer progression and therapeutic resistance.

HSP27-Mediated Extracellular and Intracellular Signaling Pathways Synergistically Confer Chemoresistance in Squamous Cell Carcinoma of Tongue

Purpose: Squamous cell carcinoma of tongue (SCCT) is the most common type of oral cavity carcinoma. Chemoresistance in SCCT is common, and the underlying mechanism remains largely unknown. We aimed to identify key molecules and signaling pathways mediating chemoresistance in SCCT.Experimental Design: Using a proteomic approach, we found that the HSP27 was a potential mediator for chemoresistance in SCCT cells. To further validate this role of HSP27, we performed various mechanistic studies using in vitro and in vivo models as well as serum and tissue samples from SCCT patients.Results: The HSP27 protein level was significantly increased in the multidrug-resistant SCCT cells and cell culture medium. Both HSP27 knockdown and anti-HSP27 antibody treatment reversed chemoresistance. Inversely, both HSP27 overexpression and recombinant human HSP27 protein treatment enhanced chemoresistance. Moreover, chemotherapy significantly induced HSP27 protein expression in both SCCT cells and their culture medium, as well as in tumor tissues and serum of SCCT patients. HSP27 overexpression predicts a poor outcome for SCCT patients receiving chemotherapy. Mechanically, extracellular HSP27 binds to TLR5 and then activates NF-κB signaling to maintain SCCT cell survival. TLR5 knockdown or restored IκBα protein level disrupts extracellular HSP27-induced NF-κB transactivation and chemoresistance. Moreover, intracellular HSP27 binds to BAX and BIM to repress their translocation to mitochondrion and subsequent cytochrome C release upon chemotherapy, resulting in inhibition of the mitochondrial apoptotic pathway.Conclusions: HSP27 plays a pivotal role in chemoresistance of SCCT cells via a synergistic extracellular and intracellular signaling. HSP27 may represent a potential biomarker and therapeutic target for precision SCCT treatment. Clin Cancer Res; 24(5); 1163-75. ©2017 AACR.

A review on SLE and malignancy

Systemic lupus erythematosus (SLE) is a chronic, systemic autoimmune disease characterized by autoantibody production, complement activation, and immune complex deposition. It predominantly affects young and middle-aged women. While improvements in the diagnosis and treatment of SLE have altered prognosis, morbidity and mortality rates remain higher than the general population. In addition to renal injury, cardiovascular disease, and infection, malignancy is known to be a significant cause of death in this population. There is increasing evidence to suggest that patients with SLE have a slightly higher overall risk of malignancy. The risk of malignancy in SLE is of considerable interest because the immune and genetic pathways underlying the pathogenesis of SLE and the immunosuppressant drugs (ISDs) used in its management may mediate this altered risk. Our current understanding of these and other risk factors and the implications for treating SLE and screening for malignancy is still evolving. This review summarizes the association between SLE and malignancy. The first section discusses the risk of overall and site-specific malignancies in both adult- and pediatric-onset SLE. Next, we evaluate the risk factors and possible mechanisms underlying the link between malignancy and SLE, including the use of ISDs, presence of certain SLE-related autoantibodies, chronic immune dysregulation, environmental factors, and shared genetic susceptibility. Finally, we review guidelines regarding cancer screening and vaccination for human papilloma virus.

A novel DNA methylation score accurately predicts death from prostate cancer in men with low to intermediate clinical risk factors

Clinically aggressive disease behavior is difficult to predict in men with low to intermediate clinical risk prostate cancer and methylation biomarkers may be a valuable adjunct for assessing the management of these patients. We set to evaluate the utility of DNA methylation to identify high risk disease in men currently considered as low or intermediate risk. DNA was extracted from formalin-fixed paraffin-embedded transurethral prostate resection tissues collected during the years 1990-96 in a watchful-waiting cohort of men in the UK. The primary end point was death of prostate cancer, assessed by reviewing cancer registry records from 2009. Methylation was quantified by pyrosequencing assays for six genes (HSPB1, CCND2, TIG1, DPYS, PITX2, and MAL) with established biomarker value in prostate cancer. A novel prognostic methylation score was developed by multivariate Cox modelling using the six methylation biomarkers in 385 men with low-and-intermediate clinical risk variables and its prognostic value compared to two previously defined clinically-derived risk scores. Methylation score was the most significant variable in univariate and bivariate analysis in men with low-to-intermediate CAPRA risk score. When combined with CAPRA score the hazard ratio was 2.02; 95% confidence interval, 1.40-2.92. For a methylation score sensitivity of 83% the specificity was 44%, while the maximum achieved sensitivity by CAPRA was 68% at a specificity of 44%. The derived methylation score is a strong predictor of aggressive prostate cancer that could have an important role in directing the management of patients with low-to-intermediate risk disease. The estimated areas under the curve (AUC) at 10 years of follow-up were 0.62 (95% CI: 0.51, 0.70) and 0.74 (95% CI: 0.65, 0.82) for CAPRA, and combined (CAPRA + methylation) risk score (CRS) respectively.

Functional genetic variability at promoters of pro-(IL-18) and anti-(IL-10) inflammatory affects their mRNA expression and survival in prostate carcinoma patients: Five year follow-up study

BACKGROUND

Inflammation is an important hallmark of all cancers. The net inflammatory response is determined by a delicate balance between pro- and anti-inflammatory cytokines, which, in turn, is determined by the genetic make-up. The present study investigates the role of variations in the promoter regions of IL-18 and IL-10 (anti-inflammatory) cytokines on mRNA expressions and survival in prostate cancer (PCa) patients.

METHODS

The study was conducted on 584 volunteer males (291 patients of PCa, between 40-80 years of age. Genetic variants were studied by using RFLP and confirmed by probe based method. Expressions of mRNA were evaluated by real-time PCR (Roche light cycler 480). Relative mRNA and fold change gene expressions were analyzed by ([1/2] (ΔCt) ) and (2(-ΔΔCt) ) methods, respectively, and 5 year follow-ups were evaluated by Log-rank (Mantel-Cox) test with Log-rank test for trends.

RESULTS

IL-18 mRNA expression was significantly elevated in GG genotypes (at -137) of PCa with relative mRNA expression of 13.95, that is, 8.48 folds higher (P < 0.05) than controls; and showed a significant median survival of 1243 days. The CC genotypes of IL-10 at both loci (-819 T/C and -592C/A) showed 3.63 and 3.52 higher relative mRNA expressions than controls, but poor survival of 984 and 1052 days than TT of 1359 days and AA of 1371 days.

CONCLUSIONS

Genetic variants of pro-inflammatory IL-18 which showed higher relative mRNA expressions have better survival. Genetic variants of anti-inflammatory IL-10 with higher relative mRNA expression showed decreased chances of survival.

Malignancies in systemic lupus erythematosus: a 2015 update

PURPOSE OF REVIEW

Patients with systemic lupus erythematosus (SLE) have altered incidences of certain malignancies as compared with the general population. This review summarizes the recent literature on risk of malignancy in SLE and proposed mechanisms for these altered susceptibilities.

RECENT FINDINGS

Recent studies have confirmed previous data showing an increased risk of non-Hodgkin's lymphoma, lung, liver, vulvar/vaginal, and thyroid malignancies, whereas demonstrating a decreased risk of breast and prostate cancer. Lymphomagenesis in SLE has been linked to increased activity of multiple inflammatory cytokines as well as possible viral diseases. The decreased rates of hormone-sensitive cancers, such as breast and prostate, are speculated to be related to the presence of lupus autoantibodies and downregulation of certain proteins in SLE. This knowledge has been utilized to investigate new therapeutic modalities for these malignancies.

SUMMARY

Recent data confirm previously reported altered malignancy rates in SLE. Most striking in recent years are publications further elucidating mechanisms underlying cancer development in SLE, and subsequent investigations of potential therapeutics modulating these pathways.

Heat shock protein 27 regulates human prostate cancer cell motility and metastatic progression

Prostate cancer (PCa) is the most common form of cancer in American men. Mortality from PCa is caused by the movement of cancer cells from the primary organ to form metastatic tumors at distant sites. Heat shock protein 27 (HSP27) is known to increase human PCa cell invasion and its overexpression is associated with metastatic disease. The role of HSP27 in driving PCa cell movement from the prostate to distant metastatic sites is unknown. Increased HSP27 expression increased metastasis as well as primary tumor mass. In vitro studies further examined the mechanism of HSP27-induced metastatic behavior. HSP27 did not affect cell detachment, adhesion, or migration, but did increase cell invasion. Cell invasion was dependent upon matrix metalloproteinase 2 (MMP-2), whose expression was increased by HSP27. In vivo, HSP27 induced commensurate changes in MMP-2 expression in tumors. These findings demonstrate that HSP27 drives metastatic spread of cancer cells from the prostate to distant sites, does so across a continuum of expression levels, and identifies HSP27-driven increases in MMP-2 expression as functionally relevant. These findings add to prior studies demonstrating that HSP27 increases PCa cell motility, growth and survival. Together, they demonstrate that HSP27 plays an important role in PCa progression.

HSP27 is commonly expressed in cervical intraepithelial lesions of Brazilian women

Heat shock proteins are molecular chaperones that may be constitutively present in cells protecting them from various stresses, such as extreme temperature, anoxia or chemical agents. Cervical cancer is the second most prevalent malignancy of women. In this study, we analyzed the expression of Hsp27 by immunohistochemistry in cervical intraepithelial lesions of Brazilian women, along with samples from non neoplasic lesions (NN). Cervical intraepithelial neoplasia I (CIN I), II (CIN II) and III (CIN III)/in situ carcinoma and squamous cell carcinoma (SCC) were included. Immunostaining was observed in 30 (100%) samples of NN, 46 (92%) in CIN I, 50 (100%) in CIN II, 52 (98.11%) in CIN III/CIS, and 46 (98.11%) in SCC. In group NN Hsp27 immunostaining was heterogeneous, more intense in basal and parabasal layers of the epithelium and less or absent in the intermediate and superficial layer. The majority of the samples of CIS and SCC presented strong staining in allepithelial layers. Metaplasic cells, when present, were strongly stained. In this study, Hsp27 protein was found to be commonly expressed in cervical epithelial cells.

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.

DNA methylation gene-based models indicating independent poor outcome in prostate cancer

BACKGROUND

Prostate cancer has a variable clinical behaviour with frequently unpredictable outcome. DNA methylation plays an important role in determining the biology of cancer but prognostic information is scanty. We assessed the potential of gene-specific DNA methylation changes to predict death from prostate cancer in a cohort of untreated men in the UK.

METHODS

This was a population-based study in which cases were identified from six cancer registries in Great Britain. DNA was extracted from formalin-fixed paraffin wax-embedded transurethral prostate resection tissues collected during 1990-96 from men with clinically-localised cancer who chose not to be treated for at least 6 months following diagnosis. The primary end point was death from prostate cancer. Outcomes were determined through medical records and cancer registry records. Pyrosequencing was used to quantify methylation in 13 candidate genes with established or suggested roles in cancer. Univariate and multivariate Cox models were used to identify possible predictors for prostate cancer-related death.

RESULTS

Of 367 men, 99 died from prostate cancer during a median of 9.5 years follow-up (max = 20). Univariately, 12 genes were significantly associated with prostate cancer mortality, hazard ratios ranged between 1.09 and 1.28 per decile increase in methylation. Stepwise Cox regression modelling suggested that the methylation of genes HSPB1, CCND2 and DPYS contributed objective prognostic information to Gleason score and PSA with respect to cancer-related death during follow-up (p = 0.006).

CONCLUSION

Methylation of 13 genes was analysed in 367 men with localised prostate cancer who were conservatively treated and stratified with respect to death from prostate cancer and those who survived or died of other causes. Of the 13 genes analysed, differential methylation of HSPB1, CCND2 and DPYS provided independent prognostic information. Assessment of gene-methylation may provide independent objective information that can be used to segregate prostate cancers at diagnosis into predicted behavioural groups.

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.

Mitogen-activated protein kinase-activated protein kinase 2 in neuroinflammation, heat shock protein 27 phosphorylation, and cell cycle: role and targeting

Mitogen-activated protein kinase (MAPK)-activated protein kinase 2 (MAPKAPK-2 or MK2) is a downstream substrate of the p38 MAPK responsible for the signaling events influencing inflammation, cell division and differentiation, apoptosis, and cell motility in response to a wide range of extracellular stimuli. After the failure of p38 MAPK inhibitors in clinical trials, MK2 was unveiled as a potential target to regulate inflammatory cytokines' mRNA stability and translation. Recent work suggests that this mechanism may underlie the pathophysiology of brain disorders associated with inflammation. In addition, MK2 is a prominent kinase that phosphorylates heat shock protein 27 (Hsp27), an intensively investigated biomarker of cancer progression. This phosphorylation decreases the chaperone properties of Hsp27, making MK2 an endogenous inhibitor of Hsp27. MK2 is also one of the major players in the signal transduction pathways activated in response to DNA damage. Experimental evidence highlights the role of MK2 in G(2)/M and the mitotic spindle checkpoints, two mechanisms by which MK2 contributes to the maintenance of genomic stability. Thus, MK2 is considered a good molecular target to increase, in combination with chemotherapeutic agents, the sensitivity of treatment, especially in p53-mutated tumors. This review looks at the functions of MK2 in inflammation, Hsp27 regulation, and cell cycle checkpoint control with a focus on brain pathologies. Analysis of MK2 signaling in various disease models and a summary of the data on MK2 inhibitors suggest novel indications for MK2 inhibitors in addition to their mainstream use against peripheral inflammatory disorders.

Molecular markers for prostate cancer in formalin-fixed paraffin-embedded tissues

Prostate cancer (PCa) is the most frequently diagnosed type of cancer in developed countries. The decisive method of diagnosis is based on the results of biopsies, morphologically evaluated to determine the presence or absence of cancer. Although this approach leads to a confident diagnosis in most cases, it can be improved by using the molecular markers present in the tissue. Both miRNAs and proteins are considered excellent candidates for biomarkers in formalin-fixed paraffin-embedded (FFPE) tissues, due to their stability over long periods of time. In the last few years, a concerted effort has been made to develop the necessary tools for their reliable measurement in these types of samples. Furthermore, the use of these kinds of markers may also help in establishing tumor grade and aggressiveness, as well as predicting the possible outcomes in each particular case for the different treatments available. This would aid clinicians in the decision-making process. In this review, we attempt to summarize and discuss the potential use of microRNA and protein profiles in FFPE tissue samples as markers to better predict PCa diagnosis, progression, and response to therapy.

Heat shock protein 27: a potential biomarker of peritoneal metastasis in epithelial ovarian cancer?

Ovarian cancer is the major gynaecologic malignancy and the leading cause of death in gynaecological cancer. Heat shock proteins (HSPs) are highly expressed in many malignant cancers and involved in metastasis including ovarian cancer. The early detection of peritoneal metastases in epithelial ovarian cancer may be more important in clinical care. HSP27, a small heat shock protein, is correlated with peritoneal metastases in epithelial ovarian cancer tissues. In this study, we investigated whether the levels of total HSP27 were detectable in serum and whether it could be a predictive biomarker for peritoneal metastases in epithelial ovarian cancer. Serum samples from 48 patients with epithelial ovarian cancer, 35 patients with benign ovarian tumours and 24 healthy women were included in this study. The serum levels of total HSP27 were measured by enzyme-linked immunosorbent assay (ELISA). There was no difference in the serum levels of total HSP27 between women with benign ovarian tumours and healthy women. However, the serum levels of total HSP27 were significantly increased in patients with epithelial ovarian cancer. The increased serum levels of total HSP27 were only seen in patients with peritoneal metastases. Furthermore, increased serum levels of total HSP27 were significantly reduced after the combination chemotherapies in patients with peritoneal metastases. These data suggest that circulating HSP27 levels were increased in epithelial ovarian cancer and correlated with peritoneal metastases. The measurement of serum HSP27 levels may be used as a potential additional indicator for peritoneal metastases in epithelial ovarian cancer and response to treatment.

Inhibition of Hsp27 radiosensitizes head-and-neck cancer by modulating deoxyribonucleic acid repair

PURPOSE

To present a novel method of tumor radiosensitization through Hsp27 knockdown using locked nucleic acid (LNA) and to investigate the role of Hsp27 in DNA double strand break (DSB) repair.

METHODS AND MATERIALS

Clonogenic survival assays, immunoblotting, the proximity ligation assay, and γH2AX foci analysis were conducted in SQ20B and FaDu human head-and-neck cancer cell lines treated with Hsp27 LNA and Hsp27 short hairpin RNA (shRNA). Additionally, nude mice with FaDu flank tumors were treated with fractionated radiation therapy after pretreatment with Hsp27 LNA and monitored for tumor growth.

RESULTS

Hsp27 LNA and Hsp27 shRNA radiosensitized head-and-neck cancer cell lines in an Hsp27-dependent manner. Ataxia-Telangectasia Mutated-mediated DNA repair signaling was impaired in irradiated cells with Hsp27 knockdown. ATM kinase inhibition abrogated the radiosensitizing effect of Hsp27. Furthermore, Hsp27 LNA and shRNA both attenuated DNA repair kinetics after radiation, and Hsp27 was found to colocalize with ATM in both untreated and irradiated cells. Last, combined radiation and Hsp27 LNA treatment in tumor xenografts in nude mice suppressed tumor growth compared with either treatment alone.

CONCLUSIONS

These results support a radiosensitizing property of Hsp27 LNA in vitro and in vivo, implicate Hsp27 in double strand break repair, and suggest that Hsp27 LNA might eventually serve as an effective clinical agent in the radiotherapy of head-and-neck cancer.

Prognostic value of PTEN loss in men with conservatively managed localised prostate cancer

Background:

The natural history of prostate cancer is highly variable and difficult to predict. We report on the prognostic value of phosphatase and tensin homologue (PTEN) loss in a cohort of 675 men with conservatively managed prostate cancer diagnosed by transurethral resection of the prostate.

Methods:

The PTEN status was assayed by immunohistochemistry (PTEN IHC) and fluorescent in situ hybridisation (PTEN FISH). The primary end point was death from prostate cancer.

Results:

The PTEN IHC loss was observed in 18% cases. This was significantly associated with prostate cancer death in univariate analysis (hazard ratio (HR)=3.51; 95% CI 2.60–4.73; P=3.1 × 10⁻¹⁴). It was highly predictive of prostate cancer death in the 50% of patients with a low risk score based on Gleason score, PSA, Ki-67 and extent of disease (HR=7.4; 95% CI 2.2–24.6; P=0.012) ), but had no prognostic value in the higher risk patients. The PTEN FISH loss was only weakly associated with PTEN IHC loss (κ=0.5). Both PTEN FISH loss and amplification were univariately predictive of death from prostate cancer, but this was not maintained in the multivariate analyses.

Conclusion:

In low-risk patients, PTEN IHC loss adds prognostic value to Gleason score, PSA, Ki-67 and extent of disease.

Mini-review: Foldosome regulation of androgen receptor action in prostate cancer

Steroid hormone receptors play diverse roles in many aspects of human physiology including cell division, apoptosis and homeostasis, tissue differentiation, sexual development and response to stress. These ligand-activated transcription factors require the functional activity of numerous chaperone and chaperone-associated proteins, collectively termed the foldosome, at the crucial step of ligand recognition and binding. Since the initial isolation of foldosome components and pioneering research by Pratt, Toft and colleagues we understand much regarding cytosolic receptor function. The classical view, that the role of foldosome components is restricted to the cytosol, has been modified over recent years by research highlighting additional roles of chaperone proteins in nuclear translocation and target gene expression. Further, dysregulation of chaperone activity and expression has been implicated in various cancers, including breast and prostate cancer. Consequently, the foldosome provides an attractive therapeutic target in steroid hormone receptor-driven malignancies. This review summarises current knowledge of how the foldosome impacts upon androgen receptor signalling, which is the key therapeutic target on prostate cancer, and how foldosome components may be used as biomarkers or therapeutic targets in this disease.

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).

Heat shock protein 27 as a prognostic and predictive biomarker in pancreatic ductal adenocarcinoma

A role of heat shock protein 27 (HSP27) as a potential biomarker has been reported in various tumour entities, but comprehensive studies in pancreatic cancer are lacking. Applying tissue microarray (TMA) analysis, we correlated HSP27 protein expression status with clinicopathologic parameters in pancreatic ductal adenocarcinoma specimens from 86 patients. Complementary, we established HSP27 overexpression and RNA-interference models to assess the impact of HSP27 on chemo- and radiosensitivity directly in pancreatic cancer cells. In the TMA study, HSP27 expression was found in 49% of tumour samples. Applying univariate analyses, a significant correlation was found between HSP27 expression and survival. In the multivariate Cox-regression model, HSP27 expression emerged as an independent prognostic factor. HSP27 expression also correlated inversely with nuclear p53 accumulation, indicating either protein interactions between HSP27 and p53 or TP53 mutation-dependent HSP27-regulation in pancreatic cancer. In the sensitivity studies, HSP27 overexpression rendered HSP27 low-expressing PL5 pancreatic cancer cells more susceptible towards treatment with gemcitabine. Vice versa, HSP27 protein depletion in HSP27 high-expressing AsPC-1 cells caused increased gemcitabine resistance. Importantly, HSP27 expression was inducible in pancreatic cancer cell lines as well as primary cells. Taken together, our study suggests a role for HSP27 as a prognostic and predictive marker in pancreatic cancer. Assessment of HSP27 expression could thus facilitate the identification of specific patient subpopulations that might benefit from individualized treatment options. Additional studies need to clarify whether modulation of HSP27 expression could represent an attractive concept to support the incorporation of hyperthermia in clinical treatment protocols for pancreatic cancer.

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.

Splice variant PRKC-ζ(-PrC) is a novel biomarker of human prostate cancer

BACKGROUND

Previously, using gene-knockdown techniques together with genome expression array analysis, we showed the gene protein Kinase C (PKC)-zeta (PRKCZ) to mediate the malignant phenotype of human prostate cancer. However, according to NCBI, the gene has undergone several major iterations. Therefore, to understand the relationship between its structure and biological activities, we have analysed its expressed sequence in prostate cancer cell lines and tissues.

METHODS

Transcriptome-walking and targeted PCR were used to sequence the mRNA transcribed from PRKCZ. Hydropathy analysis was employed to analyse the hypothetical protein sequence subsequently translated and to identify an appropriate epitope to generate a specific monoclonal antibody.

RESULTS

A novel sequence was identified within the 3'-terminal domain of human PRKCZ that, in prostate cancer cell lines and tissues, is expressed during transcription and thereafter translated into protein (designated PKC-ζ(-PrC)) independent of conventional PKC-ζ(-a). The monoclonal antibody detected expression of this 96 kD protein only within malignant prostatic epithelium.

INTERPRETATION

Transcription and translation of this gene sequence, including previous intronic sequences, generates a novel specific biomarker of human prostate cancer. The presence of catalytic domains characteristic of classic PKC-β and atypical PKC-ι within PKC-ζ(-PrC) provides a potential mechanism for this PRKCZ variant to modulate the malignant prostatic phenotype out-with normal cell-regulatory control.

Loss of HITS (FAM107B) expression in cancers of multiple organs: tissue microarray analysis

Family with sequence similarity 107 (FAM107) proteins consist of two subtypes, FAM107A and FAM107B in mammals, possessing a conserved N-terminal domain of unknown function. Recently we found that FAM107B, an 18 kDa nuclear protein, is expressed in a broad range of tissues and is downregulated in gastrointestinal cancer. Because FAM107B expression is amplified by heat-shock stimulation, we designated it heat shock-inducible tumor small protein (HITS). Although data related to FAM107A as a candidate tumor suppressor have been accumulated, little biological information is available for HITS. In the present study, we examined HITS expression using immunohistochemistry with tissue microarrays and performed detailed statistical analyses. By screening a high-density multiple organ tumor and normal tissue microarray, HITS expression was decreased in tumor tissues of the breast, thyroid, testis and uterine cervix as well as the stomach and colon. Further analysis of tissue microarrays of individual organs showed that loss of HITS expression in cancer tissues was statistically significant and commonly observed in distinct organs in a histological type-specific manner. The HITS expression intensity was inversely correlated with the primary tumor size in breast and thyroid cancers. In addition, effects of tetracycline-inducible HITS expression on tumor growth were investigated in vivo. Forced expression of HITS inhibited tumor xenograft proliferation, compared with the mock-treated tumor xenograft model. These results show that loss of HITS expression is a common phenomenon observed in cancers of distinct organs and involved in tumor development and proliferation.

Increased expression of heat shock protein 27 correlates with peritoneal metastasis in epithelial ovarian cancer

Ovarian cancer is the third most common gynecologic malignancy and the leading cause of death in gynecological cancer. Although the 5-year survival rate is increasing, peritoneal metastasis of ovarian cancer is still a problem because of no potential predictor. Heat shock proteins (HSPs) are a class of functionally related proteins that are highly expressed in many malignant cancers. Previous studies suggest high levels of HSP27 present in the serum of patients with ovarian cancer. In this study, we investigated whether the expression of HSP27 in epithelial ovarian cancer tissue was associated with peritoneal metastasis and whether HSP27 could be used as a potential predictor of peritoneal metastasis in epithelial ovarian cancer. Tissues from epithelial ovarian cancer with or without peritoneal metastasis were collected and the levels of HSP27 messenger RNA and protein determined by real-time polymerase chain reaction and Western blotting. Immunohistochemistry was used to determine the subcellular localization of HSP27. Immunohistochemistry images showed that HSP27 was highly expressed in the cytoplasm of epithelial cancer cells with peritoneal metastasis. Messenger RNA and protein levels of HSP27 were significantly increased in epithelial ovarian cancer with peritoneal metastasis compared with epithelial ovarian cancer without peritoneal metastasis. Higher expression of HSP27 correlated with poor clinical outcome. These data suggest that higher level of HSP27 was associated with peritoneal metastasis in epithelial ovarian cancer. Heat shock protein 27 may be a useful prognostic marker of poor survival and may provide a basis for the development of molecular therapeutics modulating this survival pathway.

Phosphoprotein profiling predicts response to tyrosine kinase inhibitor therapy in chronic myeloid leukemia patients

Tyrosine kinase inhibitors (TKIs) have dramatically improved treatment outcomes in chronic myeloid leukemia (CML), but a proportion of patients fail to achieve optimal molecular response. By using a phosphoproteomic approach, we aimed to discover aberrant signaling pathways and putative biomarkers in bone marrow samples of suboptimally responding patients, which could be used to guide treatment selection at the diagnosis. The study consisted of 20 chronic-phase CML patients (10 optimal and 10 suboptimal response patients based on 18 months European-Leukemia-Net criteria) and healthy bone marrow cells, and CML cell lines were used as controls. The phosphorylation profile of normal bone marrow cells diverged from CML patients expectedly but, interestingly, CML cell lines (such as K562) also showed marked difference with primary CML cells. Several phosphoproteins were elevated in suboptimal patients compared to optimal response group. Most prominent differences were seen in signal transducers and activators of transcription 5b, phospholipase C γ-1, proline-rich tyrosine kinase 2, Hck, and Paxillin. These phosphoproteins were also increased in three additional nonresponder patients studied, but each of them also had unique phosphorylation patterns, such as highly active HSP27 protein in one patient. In conclusion, suboptimal imatinib response is related to increased phosphorylation of several proteins at diagnosis, which might guide the selection of TKI therapy. Furthermore, the activation of additional BCR-ABL-independent pathways in nonresponder patients (such as the anti-apoptotic HSP27 pathway) may reveal novel therapy targets.

Proteomic analysis of differentially expressed proteins in esophageal squamous cell carcinoma by MALDI-TOF-MS

AIM: To analyze differentially expressed proteins between human normal esophageal epithelial cells (NEEC) and esophageal squamous cell carcinoma (ESCC) cells.

METHODS: NEEC and ESCC cells were cut by laser capture microdissection (LCM), and total proteins of the cells were separated by two-dimensional gel electrophoresis (2-DE). 2-DE images were analyzed using Imagemaster 2D software. Differential proteins between NEEC and ESCC cells were identified by matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF-MS).

RESULTS: A total of 43 protein spots were discovered and there were 17 differentially expressed proteins between NECC and ESCC. Of them, 15 (such as Trangelin2, HSP27, S100A11 and GSTP) were up-regulated and two (such as SCCA1) down-regulated in ESCC.

CONCLUSION: The differentially expressed proteins identified in this study may play a role in the carcinogenesis and development of ESCC and represent potential molecular biomarkers for ESCC.

PRKC-ζ Expression Promotes the Aggressive Phenotype of Human Prostate Cancer Cells and Is a Novel Target for Therapeutic Intervention

We show protein kinase C-zeta (PKC-ζ) to be a novel predictive biomarker for survival from prostate cancer (P < 0.001). We also confirm that transcription of the PRKC-ζ gene is crucial to the malignant phenotype of human prostate cancer. Following siRNA silencing of PRKC-ζ in PC3-M prostate cancer cells, stable transfectant cell line si-PRKC-ζ-PC3-M(T1-6) is phenotypically nonmalignant in vitro and in vivo. Genome-wide expression analysis identified 373 genes to be differentially expressed in the knockdown cells and 4 key gene networks to be significantly perturbed during phenotype modulation. Functional interconnection between some of the modulated genes is revealed, although these may be within different regulatory pathways, emphasizing the complexity of their mutual interdependence. Genes with altered expression following PRKC-ζ knockdown include HSPB1, RAD51, and ID1 that we have previously described to be critical in prostatic malignancy. Because expression of PRKC-ζ is functionally involved in promoting the malignant phenotype, we propose PKC-ζ as a novel and biologically relevant target for therapeutic intervention in prostate cancer.

Cancer stroma proteome expression profile of superficial bladder transitional cell carcinoma and biomarker discovery

PURPOSE

To globally characterize the stroma expression profile of superficial bladder transitional cell carcinoma and to discuss the cancer biology as well as biomarker discovery from stromal cells.

METHODS

Laser capture microdissection was used to harvest purified bladder cancer stromal cells and normal stromal cells from 4 paired samples. Next, two-dimensional liquid chromatography-tandem mass spectrometry was used to identify the proteome expression profile. The differential proteins were further analyzed using bioinformatics tools and compared with the published literature.

RESULTS

A total of 606/601 proteins commonly appeared in 4 paired samples. Six hundred and thirty-seven proteins were differentially expressed between cancer and normal stroma. Among them, 321/316 proteins specific expressed in cancer/normal stromal cells. Differential proteins were compared with the entire list of the international protein index (IPI). 36/49 GO terms exhibited as enriched and 25/14 exhibited as depleted in biological process; 39/40 GO terms exhibited as enriched and 9/4 exhibited as depleted in cellular component, respectively. Significantly altered pathways between cancer/normal stroma mainly include focal adhesion, EHEC, oxidative phosphorylation, glycolysis/gluconeogenesis, TCA cycle. Finally, descriptive statistics show the data that PI ≤ 8 have normal distribution and the proteins with extremes of PI and MW have the same probability to be a biomarker.

CONCLUSIONS

The present study identified the proteome expression profile of bladder cancer stromal cells and normal stromal cells. Furthermore, our results confirm proteins origin from stroma play important role in cancer biology and highlight a novel view of cancer and stress the importance of including factors related to the cancer stroma into biomarker discovery.

siRNA knockdown of ribosomal protein gene RPL19 abrogates the aggressive phenotype of human prostate cancer

We provide novel functional data that posttranscriptional silencing of gene RPL19 using RNAi not only abrogates the malignant phenotype of PC-3M prostate cancer cells but is selective with respect to transcription and translation of other genes. Reducing RPL19 transcription modulates a subset of genes, evidenced by gene expression array analysis and Western blotting, but does not compromise cell proliferation or apoptosis in-vitro. However, growth of xenografted tumors containing the knocked-down RPL19 in-vivo is significantly reduced. Analysis of the modulated genes reveals induction of the non-malignant phenotype principally to involve perturbation of networks of transcription factors and cellular adhesion genes. The data provide evidence that extra-ribosomal regulatory functions of RPL19, beyond protein synthesis, are critical regulators of cellular phenotype. Targeting key members of affected networks identified by gene expression analysis raises the possibility of therapeutically stabilizing a benign phenotype generated by modulating the expression of an individual gene and thereafter constraining a malignant phenotype while leaving non-malignant tissues unaffected.

Evaluation of prediagnostic prostate-specific antigen dynamics as predictors of death from prostate cancer in patients treated conservatively

Prostate-specific antigen (PSA) dynamics have been proposed to predict outcome in men with prostate cancer. We assessed the value of PSA velocity (PSAV) and PSA doubling time (PSADT) for predicting prostate cancer-specific mortality (PCSM) in men with clinically localized prostate cancer undergoing conservative management or early hormonal therapy. From 1990 to 1996, 2,333 patients were identified, of whom 594 had two or more PSA values before diagnosis. We examined 12 definitions for PSADT and 10 for PSAV. Because each definition required PSA measurements at particular intervals, the number of patients eligible for each definition varied from 40 to 594 and number of events from 10 to 119. Four PSAV definitions, but no PSADT, were significantly associated with PCSM after adjustment for PSA in multivariable Cox proportional hazards regression. All four could be calculated only for a proportion of events, and the enhancements in predictive accuracy associated with PSAV had very wide confidence intervals. There was no clear benefit of PSAV in men with low PSA and Gleason grade 6 or less. Although evidence that certain PSAV definitions help to predict PCSM in the cohort exist, the value of incorporating PSAV in predictive models to assist in determining eligibility for conservative management is, at best, uncertain.

New strategies in metastatic prostate cancer: targeting the androgen receptor signaling pathway

Recent data report that abiraterone acetate, a specific inhibitor of CYP17 that is key to androgen and estrogen synthesis, improves survival in metastatic castration-resistant prostate cancer (CRPC), confirming the continued dependency of CRPC on the androgen receptor (AR) signaling pathway. MDV3100 is a novel antagonist of AR that is also in phase III clinical trials. In addition, several other agents targeting the AR axis are undergoing evaluation in early clinical studies. CRPC patients progress on these therapies with an increasing prostate specific antigen (PSA), suggesting that repeated therapeutic interventions targeting the AR signaling axis could induce secondary responses and achieve prolonged clinical benefit for a subgroup of patients. These exciting results are good news for patients but introduce a number of treatment paradigm dilemmas for physicians. Clinical studies evaluating the ideal sequence of administration of these new agents, best timing for initiation, combination strategies, discontinuation beyond progression and after commencement of subsequent therapies, and coordination with other treatments have not been done. Predictive biomarkers could allow patient selection for a specific treatment, but in their absence, most physicians will rely on a trial of treatment with a preferred agent and substitute for an alternative therapy on objective progression. Current data suggest that the response rate to drugs targeting the AR ligand-binding domain decreases with each treatment, but we hypothesize that a significant proportion of CRPC remains dependent on the AR axis and, therefore, novel strategies for disrupting AR signaling merit evaluation.

Novel targeted agents on the horizon for castration-resistant prostate cancer

Androgen deprivation treatment in prostate cancer patients is well established; however, resistance to such treatment manifests itself by progression to castration-resistant prostate cancer (CRPC). Despite significant advances in treatment options for patients with CRPC, their prognosis remains poor. Resistance results from multiple processes that facilitate cancer cell growth and survival. Mechanisms underlying the shift to castrate resistance have been attributed to a complex interplay of clonal selection, reactivation of the androgen receptor axis despite castrate levels of serum testosterone, stress-induced prosurvival genes and cytoprotective chaperone networks and alternative mitogenic growth factor pathways. This article discusses several pathways involved in the development of CRPC, with a particular focus on those mechanisms that have led to the development of new targeted therapies.

Pathology: coming in from the cold

Following the UK's organ retention scandals that occurred a decade ago, politicians unleashed a deluge of well-intentioned but naïve and unnecessarily burdensome regulations that have progressively stymied human tissue-based research, stifling development of improved diagnostic and prognostic tests as well as discovery of new treatments based on sound knowledge of human-specific biology. For the UK to maintain a leading role in medical research, more sensible levels of regulation need to be introduced that recognise differences between tissue from donors who have passed-away and surgical tissue that is surplus to diagnostic requirements and that otherwise will be incinerated. While it is important to reassure the public that research using their tissues will be conducted within an approved ethical framework, it is equally important to ensure that, as hospital staff and academic researchers, we are able to fulfil our unwritten covenant with patients to do our utmost to seek better diagnostic assays and more predictive prognostic indicators, while collaborating with our colleagues in academia and industry and hence bring hope to patients with illnesses for which no effective treatments are yet available. There is a clear case for introducing an opt-out system as the default to allow all surplus surgical tissues to be immediately available for research, concomitant with an education campaign. This is the optimal and most ethical approach to ensure the wishes of the vast majority of patients are respected by allowing their residual surgical tissues and relevant clinical information to be made available for research without the current levels of obstruction and hindrance.