Cancer-related changes in prostate DNA as men age and early identification of metastasis in primary prostate tumors

Environmental Exposure to Metals, Parameters of Oxidative Stress in Blood and Prostate Cancer: Results from Two Cohorts

We studied the potential role of exposure to various metal(oid)s (As, Cd, Cr, Hg, Ni, and Pb) in prostate cancer. Two cohorts were established: the Croatian cohort, consisting of 62 cases and 30 controls, and the Serbian cohort, consisting of 41 cases and 61 controls. Blood/serum samples were collected. Levels of investigated metal(oid)s, various parameters of oxidative stress, and prostate-specific antigen (PSA) were determined in collected samples. A comparison of the measured parameters between 103 prostate cancer patients and 91 control men from both Croatian and Serbian cohorts showed significantly higher blood Hg, SOD, and GPx levels and significantly lower serum SH levels in prostate cancer patients than in controls. Correlation analyses revealed the significant relationship between certain parameters of oxidative stress and the concentrations of the measured metal(loid)s, pointing to the possible role of metal(oid)-induced oxidative stress imbalance. Furthermore, a significant inverse relationship was found between the blood Pb and the serum PSA in prostate cancer patients, but when the model was adjusted for the impacts of remaining parameters, no significant association between the serum PSA and the measured parameters was found. The results of the overall study indicate a substantial contribution of the measured metal(loid)s to the imbalance of the oxidant/antioxidant system. Although somewhat conflicting, the results of the present study point to the possible role of investigated metal(oid)s in prostate cancer, especially for Hg, since the obtained relationship was observed for both cohorts, followed by the disturbances in oxidative stress status, which were found to be correlated with Hg levels. Nevertheless, further studies in larger cohorts are warranted to explain and confirm the obtained results.

8-Hydroxy-2-Deoxyguanosine and 8-Iso-Prostaglandin F2α: Putative Biomarkers to assess Oxidative Stress Damage Following Robot-Assisted Radical Prostatectomy (RARP)

Objective: Prostate cancer (PCa) is the most common type of cancer. Biomarkers help researchers to understand the mechanisms of disease and refine diagnostic panels. We measured urinary 8-hydroxy-2-deoxyguanosine (8-OHdG) and 8-iso-prostaglandin F2α (8-IsoF2α) to assess oxidative stress damage in PCa patients undergoing robot-assisted radical prostatectomy (RARP). Methods: Forty PCa patients were enrolled in the study. Urine was collected before (T0) and 3 months after the RARP procedure (T1). 8-OHdG and 8-IsoF2α were measured through liquid chromatography-tandem mass spectrometry. Sex- and age-matched healthy subjects served as controls (CTRL). Results: At T0, patients exhibited significantly higher levels of 8-OHdG than CTRL (p = 0.026). At T1, 23/40 patients who completed the 3-month follow-up showed levels of 8-OHdG that were significantly lower than at T0 (p = 0.042), and comparable to those of the CTRL subjects (p = 0.683). At T0, 8-Iso-PGF2α levels were significantly higher in PCa patients than in CTRL subjects (p = 0.0002). At T1, 8-Iso-PGF2α levels were significantly lower than at T0 (p < 0.001) and were comparable to those of CTRL patients (p = 0.087). Conclusions: A liquid chromatography-tandem mass spectrometry method reveals enhanced OHdG and 8-Iso-PGF2α in the urine of PCa patients. RARP normalizes such indices of oxidative stress. Large-sized sample studies and long-term follow-ups are now needed to validate these urinary biomarkers for use in the early prevention and successful treatment of PCa.

A Japanese Box Lunch Bento Comprising Functional Foods Reduce Oxidative Stress in Men: A Pilot Study

The elder population has increased, introducing the profound medical and social challenge of maintaining health in aging seniors and the need for a medical approach to sustaining physical and mental health. The relationship between diseases and lifestyle-related factors such as diet and exercise are important. A health-conscious lifestyle improves one's health condition from a medical perspective, as indicated by new wellness monitoring using health devices and recent research into the efficacy of functional lunches incorporating utilitarian agricultural, forestry, and fishery products and foods. For a period of 3 months, and solely at lunchtime, 21 participants consumed the contents of a bento (Japanese box lunch), which incorporated functional (healthy) foods. A variety of factors were analyzed, including: weight, weight fluctuation rate, abdominal girth, triglycerides, total cholesterol value, and 8-OHdG (8-hydroxy-2'-deoxyguanosine). The bento comprising functional foods resulted in a reduction in both weight and abdominal girth without calorie restrictions. A reduction over time was observed in 8-OHdG, an oxidative stress marker, as compared to values prior to initiation of the study. Usage of a health device, exercise/dietary advice from a physician and nutritionist, and the availability of meals incorporating functional agricultural products might help prevent lifestyle disease and lead to improved health management.

Oxidative Stress and Antioxidant Status in High-Risk Prostate Cancer Subjects

The oxidant/antioxidant balance has been implicated in the pathophysiology of prostate cancer. We investigated oxidative damage and antioxidant status in high-risk prostate cancer subjects. Reduced glutathione (GSH) levels were measured in erythrocytes, 8-hydroxydeoxyguanosine (8-OHdG) in leukocytes and plasma levels of catalase (CAT), glutathione peroxidase (GSH-Px), glutathione reductase (GSH-R), glutathione S-transferase (GST), superoxide dismutase (SOD), and lipid peroxide products were measured in high-risk and age-matched healthy subjects. Serum PSA levels were significantly higher (p < 0.0001) in high-risk subjects, whereas GST (p < 0.0001) and GSH (p < 0.002) were higher in healthy controls. Levels of 8-OHdG, an oxidized nucleoside of DNA, were significantly increased (p < 0.0001) in high-risk subjects. No marked difference in the levels of CAT (p = 0.237), GSH-Px (p = 0.74), GSH-R (p = 0.344), SOD (p = 0.109), and lipid peroxide products (p = 0129) were observed between two groups. Pearson's correlation between GST and PSA (r = -0.69 (p < 0.0001)), GST and 8-OHdG (r = -0.62 (p < 0.0004)), GSH and 8-OHdG (r= -0.39 (p = 0.038)), and CAT and GSH-Px (r= -0.33 (p = 0.04)) were found to be negatively correlated, whereas 8-OHdG and PSA were positively associated (r= 0.57 (p < 0.002). These results indicate a significant role of oxidative damage in prostate carcinogenesis, particularly during the early stages of development. In conclusion, our data support the importance of antioxidant defense as a valuable diagnostic and/or prognostic marker in prostate cancer.

Retinal oxidative stress at the onset of diabetes determined by synchrotron FTIR widefield imaging: towards diabetes pathogenesis

Diabetic retinopathy is a microvascular complication of diabetes that can lead to blindness. In the present study, we aimed to determine the nature of diabetes-induced, highly localized biochemical changes in the neuroretina at the onset of diabetes. High-resolution synchrotron Fourier transform infrared (s-FTIR) wide field microscopy coupled with multivariate analysis (PCA-LDA) was employed to identify biomarkers of diabetic retinopathy with spatial resolution at the cellular level. We compared the retinal tissue prepared from 6-week-old Ins2^Akita/+ heterozygous (Akita/+, N = 6; a model of diabetes) male mice with the wild-type (control, N = 6) mice. Male Akita/+ mice become diabetic at 4-weeks of age. Significant differences (P < 0.001) in the presence of biomarkers associated with diabetes and segregation of spectra were achieved. Differentiating IR bands attributed to nucleic acids (964, 1051, 1087, 1226 and 1710 cm^-1), proteins (1662 and 1608 cm^-1) and fatty acids (2854, 2923, 2956 and 3012 cm^-1) were observed between the Akita/+ and the WT samples. A comparison between distinctive layers of the retina, namely the photoreceptor retinal layer (PRL), outer plexiform layer (OPL), inner nucleus layer (INL) and inner plexiform layer (IPL) suggested that the photoreceptor layer is the most susceptible layer to oxidative stress in short-term diabetes. Spatially-resolved chemical images indicated heterogeneities and oxidative-stress induced alterations in the diabetic retina tissue morphology compared with the WT retina. In this study, the spectral biomarkers and the spatial biochemical alterations in the diabetic retina and in specific layers were identified for the first time. We believe that the conclusions drawn from these studies will help to bridge the gap in our understanding of the molecular and cellular mechanisms that contribute to the pathobiology of diabetic retinopathy.

Insulin-like growth factor 2 expression in prostate cancer is regulated by promoter-specific methylation

Deregulation of the insulin-like growth factor (IGF) axis and dysbalance of components of the IGF system as potential therapeutic targets have been described in different tumor types. IGF2 is a major embryonic growth factor and an important activator of IGF signaling. It is regulated by imprinting in a development- and tissue-dependent manner and has been implicated in a broad range of malignancies including prostate cancer (PCa). Loss of imprinting (LOI) usually results in bi-allelic gene expression and increased levels of IGF2. However, the regulatory mechanisms and the pathophysiological impact of altered IGF2 expression in PCa remain elusive. Here, we show that in contrast to many other tumors, IGF2 mRNA and protein levels were decreased in 80% of PCa in comparison with non-neoplastic adjacent prostate and were independent of LOI status. Instead, IGF2 expression in both tumors and adjacent prostate depended on preferential usage of the IGF2 promoters P3 and P4. Decreased IGF2 expression in tumors was strongly related to hypermethylation of these two promoters. Methylation of the A region in promoter P4 correlated specifically with IGF2 expression in the 20% of PCa where IGF2 was higher in tumors than in adjacent prostate. We conclude that IGF2 is downregulated in most PCa and may be particularly relevant during early stages of tumor development or during chemotherapy and androgen deprivation. PCa differs from other tumors in that IGF2 expression is mainly regulated through methylation of promoter-specific and not by imprinting. Targeting of promoter-specific regions may have relevance for the adjuvant treatment of PCa.

Formation and repair of oxidatively generated damage in cellular DNA

In this review article, emphasis is placed on the critical survey of available data concerning modified nucleobase and 2-deoxyribose products that have been identified in cellular DNA following exposure to a wide variety of oxidizing species and agents including, hydroxyl radical, one-electron oxidants, singlet oxygen, hypochlorous acid and ten-eleven translocation enzymes. In addition, information is provided about the generation of secondary oxidation products of 8-oxo-7,8-dihydroguanine and nucleobase addition products with reactive aldehydes arising from the decomposition of lipid peroxides. It is worth noting that the different classes of oxidatively generated DNA damage that consist of single lesions, intra- and interstrand cross-links were unambiguously assigned and quantitatively detected on the basis of accurate measurements involving in most cases high performance liquid chromatography coupled to electrospray ionization tandem mass spectrometry. The reported data clearly show that the frequency of DNA lesions generated upon severe oxidizing conditions, including exposure to ionizing radiation is low, at best a few modifications per 106 normal bases. Application of accurate analytical measurement methods has also allowed the determination of repair kinetics of several well-defined lesions in cellular DNA that however concerns so far only a restricted number of cases.

Repair of oxidatively induced DNA damage by DNA glycosylases: Mechanisms of action, substrate specificities and excision kinetics

Endogenous and exogenous reactive species cause oxidatively induced DNA damage in living organisms by a variety of mechanisms. As a result, a plethora of mutagenic and/or cytotoxic products are formed in cellular DNA. This type of DNA damage is repaired by base excision repair, although nucleotide excision repair also plays a limited role. DNA glycosylases remove modified DNA bases from DNA by hydrolyzing the glycosidic bond leaving behind an apurinic/apyrimidinic (AP) site. Some of them also possess an accompanying AP-lyase activity that cleaves the sugar-phosphate chain of DNA. Since the first discovery of a DNA glycosylase, many studies have elucidated the mechanisms of action, substrate specificities and excision kinetics of these enzymes present in all living organisms. For this purpose, most studies used single- or double-stranded oligodeoxynucleotides with a single DNA lesion embedded at a defined position. High-molecular weight DNA with multiple base lesions has been used in other studies with the advantage of the simultaneous investigation of many DNA base lesions as substrates. Differences between the substrate specificities and excision kinetics of DNA glycosylases have been found when these two different substrates were used. Some DNA glycosylases possess varying substrate specificities for either purine-derived lesions or pyrimidine-derived lesions, whereas others exhibit cross-activity for both types of lesions. Laboratory animals with knockouts of the genes of DNA glycosylases have also been used to provide unequivocal evidence for the substrates, which had previously been found in in vitro studies, to be the actual substrates in vivo as well. On the basis of the knowledge gained from the past studies, efforts are being made to discover small molecule inhibitors of DNA glycosylases that may be used as potential drugs in cancer therapy.

Monitoring wheat mitochondrial compositional and respiratory changes using Fourier transform mid-infrared spectroscopy in response to agrochemical treatments

Fungicides and plant growth regulators can impact plant growth outside of their effects on fungal pathogens. Although many of these chemicals are inhibitors of mitochondrial oxygen uptake, information remains limited as to whether they are able to modify other mitochondrial constituents. Fourier transform mid-infrared spectroscopy (FT-mIR) offers a high sample throughput method to comparatively and qualitatively evaluate the effects of exogenously added compounds on mitochondrial components. Therefore the objective of this study was to determine the ability of FT-mIR to detect effects mitochondrial fractions isolated from wheat (Triticum aestivum L.) seedlings in response to several agrochemical treatments, with an emphasis on fungicides. The accessed need was to develop FT-mIR analytical and statistical routines as an effective approach to differentiate spectra obtained from chemically-treated or untreated mitochondria. An NADH-dependent oxygen uptake approach was initially used as a comparative method to determine whether the fungicides (azoxystrobin, boscalid, cyazofamid, fluazinam, isopyrazam, and pyraclostrobin) and the plant growth regulator, (trinexapac-ethyl) reduced respiration inhibition on isolated mitochondria. Pyraclostrobin was the most effective inhibitor, whereas amisulbrom did not impact oxygen uptake. However, hierarchical clustering of FT-mIR spectra of isolated mitochondria treated with these different compounds separated into clades consistent with each of their expected mode of action. Analysis of the FT-mIR amide protein region indicated that amisulbrom and pyraclostrobin interacted with the isolated wheat mitochondria. Both chemicals were statistically different from the control signifying that respiration was indeed influenced by these treatments. Moreover, the entire FT-mIR region showed differences in various biological bands thereby providing additional information on mitochondria responses to agrochemicals, if so warranted.

Microfluidic approaches to synchrotron radiation-based Fourier transform infrared (SR-FTIR) spectral microscopy of living biosystems

A long-standing desire in biological and biomedical sciences is to be able to probe cellular chemistry as biological processes are happening inside living cells. Synchrotron radiation-based Fourier transform infrared (SR-FTIR) spectral microscopy is a label-free and nondestructive analytical technique that can provide spatiotemporal distributions and relative abundances of biomolecules of a specimen by their characteristic vibrational modes. Despite great progress in recent years, SR-FTIR imaging of living biological systems remains challenging because of the demanding requirements on environmental control and strong infrared absorption of water. To meet this challenge, microfluidic devices have emerged as a method to control the water thickness while providing a hospitable environment to measure cellular processes and responses over many hours or days. This paper will provide an overview of microfluidic device development for SR-FTIR imaging of living biological systems, provide contrast between the various techniques including closed and open-channel designs, and discuss future directions of development within this area. Even as the fundamental science and technological demonstrations develop, other ongoing issues must be addressed; for example, choosing applications whose experimental requirements closely match device capabilities, and developing strategies to efficiently complete the cycle of development. These will require imagination, ingenuity and collaboration.

The Role of Soy Phytoestrogens on Genetic and Epigenetic Mechanisms of Prostate Cancer

Soy phytoestrogens are dietary components with considerable effects on reducing the incidence of prostate cancer. Epidemiological studies demonstrated that occurrence of prostate cancer is relatively low in Asia and Southern Europe, a status associated with consuming of soy isoflavones, such as genistein, daidzein, and glycitein. Soy phytoestrogens exert their activity on molecular mechanisms, including cell-cycle control, induction of apoptosis, inhibition of angiogenesis, and metastasis. In addition, they have antioxidant activity and show regulatory effect on the expression of genes involved in DNA damage and repair. Furthermore, the epigenetic regulation of gene expression can be modified by soy phytoestrogens. They show regulatory effects on gene activity by altering DNA methylation and/or histone modification patterns. In this chapter, we discuss the role of soy phytoestrogens on the genetic and epigenetic mechanisms of prostate cancer. We attempt to provide further insight in order to understand the underlying mechanisms of protective effects of soy phytoestrogens in preventing prostate cancer.

A randomized, double-blind, placebo-controlled study of the effects of pomegranate extract on rising PSA levels in men following primary therapy for prostate cancer

BACKGROUND

The primary objective of this study was to compare the effects of pomegranate juice on PSA doubling times (PSADT) in subjects with rising PSA levels after primary therapy for prostate cancer.

METHODS

Double-blind, placebo-controlled multi-institutional study, evaluated the effects of pomegranate liquid extract on serum PSA levels. The primary end point of this study was change in serum PSADT. Additional secondary and exploratory objectives were to evaluate the safety of pomegranate juice and to determine the interaction of manganese superoxide dismutase (MnSOD) AA genotype and pomegranate treatment on PSADT.

RESULTS

One-hundred eighty-three eligible subjects were randomly assigned to the active and placebo groups with a ratio of 2:1 (extract N=102; placebo N=64; juice N=17). The majority of adverse events were of moderate or mild grade. Median PSADT increased from 11.1 months at baseline to 15.6 months in the placebo group (P<0.001) compared with an increase from 12.9 months at baseline to 14.5 months in the extract group (P=0.13) and an increase from 12.7 at baseline to 20.3 in the juice group (P=0.004). However, none of these changes were statistically significant between the three groups (P>0.05). Placebo AA patients experienced a 1.8 month change in median PSADT from 10.9 months at baseline to 12.7 months (P=0.22), while extract patients experienced a 12 month change in median PSADT from 13.6 at baseline to 25.6 months (P=0.03).

CONCLUSIONS

Compared with placebo, pomegranate extract did not significantly prolong PSADT in prostate cancer patients with rising PSA after primary therapy. A significant prolongation in PSADT was observed in both the treatment and placebo arms. Men with the MnSOD AA genotype may represent a group that is more sensitive to the antiproliferative effects of pomegranate on PSADT; however, this finding requires prospective hypothesis testing and validation.

Anthocyanin induces apoptosis of DU-145 cells in vitro and inhibits xenograft growth of prostate cancer

PURPOSE

To investigate the effects of anthocyanins extracted from black soybean, which have antioxidant activity, on apoptosis in vitro (in hormone refractory prostate cancer cells) and on tumor growth in vivo (in athymic nude mouse xenograft model).

MATERIALS AND METHODS

The growth and viability of DU-145 cells treated with anthocyanins were assessed using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and apoptosis was assessed by DNA laddering. Immunoblotting was conducted to evaluate differences in the expressions of p53, Bax, Bcl, androgen receptor (AR), and prostate specific antigen (PSA). To study the inhibitory effects of anthocyanins on tumor growth in vivo, DU-145 tumor xenografts were established in athymic nude mice. The anthocyanin group was treated with daily oral anthocyanin (8 mg/kg) for 14 weeks. After 2 weeks of treatment, DU-145 cells (2×10⁶) were inoculated subcutaneously into the right flank to establish tumor xenografts. Tumor dimensions were measured twice a week using calipers and volumes were calculated.

RESULTS

Anthocyanin treatment of DU-145 cells resulted in 1) significant increase in apoptosis in a dose-dependent manner, 2) significant decrease in p53 and Bcl-2 expressions (with increased Bax expression), and 3) significant decrease in PSA and AR expressions. In the xenograft model, anthocyanin treatment significantly inhibit tumor growth.

CONCLUSION

This study suggests that anthocyanins from black soybean inhibit the progression of prostate cancer in vitro and in a xenograft model.

Oxidatively induced DNA damage and its repair in cancer

Oxidatively induced DNA damage is caused in living organisms by endogenous and exogenous reactive species. DNA lesions resulting from this type of damage are mutagenic and cytotoxic and, if not repaired, can cause genetic instability that may lead to disease processes including carcinogenesis. Living organisms possess DNA repair mechanisms that include a variety of pathways to repair multiple DNA lesions. Mutations and polymorphisms also occur in DNA repair genes adversely affecting DNA repair systems. Cancer tissues overexpress DNA repair proteins and thus develop greater DNA repair capacity than normal tissues. Increased DNA repair in tumors that removes DNA lesions before they become toxic is a major mechanism for development of resistance to therapy, affecting patient survival. Accumulated evidence suggests that DNA repair capacity may be a predictive biomarker for patient response to therapy. Thus, knowledge of DNA protein expressions in normal and cancerous tissues may help predict and guide development of treatments and yield the best therapeutic response. DNA repair proteins constitute targets for inhibitors to overcome the resistance of tumors to therapy. Inhibitors of DNA repair for combination therapy or as single agents for monotherapy may help selectively kill tumors, potentially leading to personalized therapy. Numerous inhibitors have been developed and are being tested in clinical trials. The efficacy of some inhibitors in therapy has been demonstrated in patients. Further development of inhibitors of DNA repair proteins is globally underway to help eradicate cancer.

DNA damage response and prostate cancer: defects, regulation and therapeutic implications

DNA damage response (DDR) includes the activation of numerous cellular activities that prevent duplication of DNA lesions and maintain genomic integrity, which is critical for the survival of normal and cancer cells. Specific genes involved in the DDR such as BRCA1/2 and P53 are mutated during prostate cancer progression, while various oncogenic signaling such as Akt and c-Myc are activated, enhancing the replication stress and increasing the genomic instability of cancer cells. These events may render prostate cancer cells particularly sensitive to inhibition of specific DDR pathways, such as PARP in homologous recombination (HR) DNA repair and Chk1 in cell cycle checkpoint and DNA repair, creating opportunities for synthetic lethality or synergistic cytotoxicity. Recent reports highlight the critical role of androgen receptor (AR) as a regulator of DDR genes, providing a rationale for combining DNA-damaging agents or targeted DDR inhibitors with hormonal manipulation or AR inhibition as treatment for aggressive disease. The aims of this review are to discuss specific DDR defects in prostate cancer that occur during disease progression, to summarize recent advances in understanding the regulation of DDR in prostate cancer, and to present potential therapeutic opportunities through combinational targeting of the intact components of DDR signaling pathways.

Using Novel Method to Detect Different Cancer-Cell Stages of Model Human Lung Carcinoma

BACKGROUND

Synchrotron radiation infrared (SR-IR) microspectroscopy and SR-IR spectroscopic imaging are extremely valuable techniques for determining the molecular composition of biological and biomedical samples. In this work, SR-IR is applied in the study of the lung cancer cells in different cell cycles.

METHODS

We use a novel synchrotron based radiation infrared system combined synchronized model human lung carcinoma to reveal its unique character pattern.

RESULTS

After using SR-IR microspectroscopy, we discovered that the ratio of protein to lipid in G1 and G2 states is around 4.0 and 6.1, respectively. Moreover, for the DNA at the wavenumber position of 1225 cm(-1) , the intensity ratio of G2 state to G1 state is approximately 1.6. These data indicate that the cell in G1 state has more lipid composition to prepare for the DNA synthesis, but the cell in G2 state has more protein composition to prepare for the mitosis. The cell has larger DNA concentration in G2 state, which can be explained for the DNA synthesis.

CONCLUSION

Through our research, we demonstrate that different growth state of cancer cell presenting unique functional groups concentration profiles and distribution via using SR-IR microspectrometry. These applications will provide another ways to improve modern cancer screening in the future.

Plant flavone apigenin binds to nucleic acid bases and reduces oxidative DNA damage in prostate epithelial cells

Oxidative stress has been linked to prostate carcinogenesis as human prostate tissue is vulnerable to oxidative DNA damage. Apigenin, a dietary plant flavone, possesses anti-proliferative and anticancer effects; however, its antioxidant properties have not been fully elucidated. We investigated sub-cellular distribution of apigenin, it's binding to DNA and protective effects against H2O2-induced DNA damage using transformed human prostate epithelial RWPE-1 cells and prostate cancer LNCaP, PC-3 and DU145 cells. Exposure of cells to apigenin exhibited higher accumulation in RWPE-1 and LNCaP cells, compared to PC-3 and DU145 cells. The kinetics of apigenin uptake in LNCaP cells was estimated with a Km value of 5 µmole/L and Vmax of 190 pmoles/million cells/h. Sub-cellular fractionation demonstrated that nuclear matrix retains the highest concentration of apigenin (45.3%), followed by cytosol (23.9%), nuclear membranes (17.9%) and microsomes (12.9%), respectively. Spectroscopic analysis of apigenin with calf-thymus DNA exhibited intercalation as the dominant binding mode to DNA duplex. Apigenin exposure resulted in significant genoprotective effects in H2O2-stressed RWPE-1 cells by reduction in reactive oxygen species levels. In addition, apigenin exposure suppressed the formation of 8-hydroxy-2' deoxyguanosine and protected exposed cells from apoptosis. Our studies demonstrate that apigenin is readily taken up by normal prostatic epithelial cells and prostate cancer cells, and is incorporated into their nuclei, where its intercalation with nucleic acid bases may account for its antioxidant and chemopreventive activities.

Metal-mediated DNA damage and cell death: mechanisms, detection methods, and cellular consequences

Metal ions cause various types of DNA damage by multiple mechanisms, and this damage is a primary cause of cell death and disease.

A double-blind, randomized, neoadjuvant study of the tissue effects of POMx pills in men with prostate cancer before radical prostatectomy

Pomegranates slow prostate cancer xenograft growth and prolong prostate-specific antigen (PSA) doubling times in single-arm human studies. Pomegranates' effects on human prostate tissue are understudied. We hypothesized that orally administered pomegranate extract (POMx; Pom Wonderful) would lower tissue 8-hydroxy-2'-deoxyguanosine (8-OHdG), an oxidative stress biomarker. Seventy men were randomized to two tablets, POMx or placebo, daily up to four weeks before radical prostatectomy. Tissue was analyzed for intraprostatic urolithin A, a pomegranate metabolite, benign and malignant 8-OHdG, and cancer pS6 kinase, NF-κB, and Ki67. Primary endpoint was differences in 8-OHdG, and the study was powered to detect 35% reduction. POMx was associated with 16% lower benign tissue 8-OHdG (P = 0.095), which was not statistically significant. POMx was well tolerated with no treatment-related withdrawals. There were no differences in baseline clinicopathological features between arms. Urolithin A was detected in 21 of the 33 patients in the POMx group versus 12 of the 35 in the placebo group (P = 0.031). Cancer pS6 kinase, NF-κB, Ki67, and serum PSA changes were similar between arms. POMx before surgery results in pomegranate metabolite accumulation in prostate tissues. Our primary endpoint in this modest-sized short-term trial was negative. Future larger longer studies are needed to more definitively test whether POMx reduces prostate oxidative stress, as well as further animal testing to better understand the multiple mechanisms through which POMx may alter prostate cancer biology.

Pomegranate Extracts in the Management of Men's Urologic Health: Scientific Rationale and Preclinical and Clinical Data

Multiple strands of research provide growing evidence that diet, nutrition, and life style play a role in the development and the course of urological diseases. Numerous micronutrients and polyphenols found in soy, green tea, and many fruits and vegetables have been described to impact diseases including erectile dysfunction, benign prostatic hyperplasia, and prostate cancer. However, oftentimes these reports lack both a scientific rationale and supportive evidence base. The efficacy of pomegranate, on the other hand, in the modulation of central biological processes like inflammation, hypoxia, and oxidative stress that are important in the pathogenesis of urological maladies has been robustly demonstrated in preclinical in vitro and in vivo studies. Moreover, clinical trials have further supported its use in the treatment of several diseases, in particular in the management of prostate cancer. Herein, we critically review the scientific knowledge about the current role and future prospects for the use of pomegranate extracts in the therapy of erectile dysfunction, benign prostatic hyperplasia, and prostate cancer.

Oxidized extracellular DNA as a stress signal in human cells

The term "cell-free DNA" (cfDNA) was recently coined for DNA fragments from plasma/serum, while DNA present in in vitro cell culture media is known as extracellular DNA (ecDNA). Under oxidative stress conditions, the levels of oxidative modification of cellular DNA and the rate of cell death increase. Dying cells release their damaged DNA, thus, contributing oxidized DNA fragments to the pool of cfDNA/ecDNA. Oxidized cell-free DNA could serve as a stress signal that promotes irradiation-induced bystander effect. Evidence points to TLR9 as a possible candidate for oxidized DNA sensor. An exposure to oxidized ecDNA stimulates a synthesis of reactive oxygen species (ROS) that evokes an adaptive response that includes transposition of the homologous loci within the nucleus, polymerization and the formation of the stress fibers of the actin, as well as activation of the ribosomal gene expression, and nuclear translocation of NF-E2 related factor-2 (NRF2) that, in turn, mediates induction of phase II detoxifying and antioxidant enzymes. In conclusion, the oxidized DNA is a stress signal released in response to oxidative stress in the cultured cells and, possibly, in the human body; in particular, it might contribute to systemic abscopal effects of localized irradiation treatments.

Relaxed imprinting of IGF2 in peripheral blood cells of patients with a history of prostate cancer

BACKGROUND

Insulin-like growth factor 2 (IGF2) is the predominant IGF in adults and regulates cell growth. In contrast to normal tissues, where IGF2 is imprinted and only expressed from the paternal allele, loss of imprinting (LOI) and biallelic IGF2 expression are observed in many cancers including prostate cancer (PCa). We here studied whether LOI of IGF2 in normal circulating peripheral blood lymphocytes can predict increased PCa risk.

SAMPLES AND METHODS

We analyzed IGF2 protein levels, IGF2 820G/A genotype and imprinting status, as well as methylation status of the IGF2 imprinting control region (ICR) in 113 blood samples of patients with a history of radical prostatectomy (RPE) for PCa by ELISA, restriction-fragment length polymorphism, and bisulfite-DNA sequencing. Results were compared to 249 male blood donors with unknown prostate specific antigen (PSA) status.

RESULTS

The 820G/A genotype was enriched in the RPE group and was associated with younger age at cancer diagnosis. LOI in patients was only slightly more frequent than in controls, but IGF2 levels were significantly higher and uncoupled from the imprinting status. Analysis of the IGF2/H19 ICR revealed marked hypermethylation.

CONCLUSIONS

The IGF 820G/A genotype is associated with PCa diagnosis at younger age. Increased IGF2 in patients with PCa appears to be the result of impaired imprinting in non-neoplastic cells rather than a paracrine tumor product. Uncoupling of IGF2 protein levels from imprinting status (not LOI alone) and hypermethylation of the ICR characterized PCa patients and could have the potential to indicate persons at risk in screening programs.

Evaluation of oxidative stress and DNA damage in benign prostatic hyperplasia patients and comparison with controls

In the present study, oxidative stress and lymphocytic DNA damage in both pre-op and post-op benign prostrate hyperplasia (BPH) patients with age >50 years was evaluated and compared with normal healthy subjects (controls- without any evidence of disease) of the same sex and age group. From December 2007 to November 2009, oxidative stress in 45 BPH patients were evaluated both before (pre-op patients) and after 7 days of surgery (post-op patients) in terms of measurements of plasma levels of (1) various anti-oxidative enzymes, (2) non-enzymatic antioxidants and (3) malondialdehyde which is a product of lipid peroxidation. The lymphocyte DNA damage was also evaluated by single cell alkaline gel electrophoresis in terms of tail length migration in these patients. These values were compared with their respective control subjects of similar sex and age group. The activities of antioxidant enzymes and the levels of antioxidant, reduced glutathione were found significantly decreased (p < 0.05) in serum samples of pre-operative group of BPH patients as compared to the controls. These altered parameters increased significantly (p < 0.05) and returned to their near normal control values, but not up to baseline values, in post operative patients i.e. after the cancer load was decreased by surgery. Lymphocytic DNA damage was found to be significantly increased in pre-op group as compared to controls and was reduced after surgery in post-op group. The present study therefore, shows significantly increased levels of oxidative stress and DNA damage in BPH patients which were reduced after removal of tumour load. Thus oxidative damage plays an important role in prostate tumourogenesis and timely management of oxidative stress can be of importance in preventing the occurrence of BPH.

Testosterone promotes DNA damage response under oxidative stress in prostate cancer cell lines

BACKGROUND

Sustained chronic inflammation and oxidative stress in the prostate promote prostate carcinogenesis. The process of oncogenic transformation leads to enhanced DNA damage and activates the checkpoint network that functions as an inducible barrier against cancer progression. Here, we analyzed the effects of testosterone on the DNA damage response in prostate cancer cells to assess whether testosterone functions a barrier to cancer progression under the oxidative stress.

METHODS

We examined the effects of testosterone on components of the DNA damage response pathway, including ATM (ataxia-telangiectasia-mutated kinase), H2AX (histone H2AX variant), and Chk2 (checkpoint kinase2) in prostate cancer cell lines, treated with various concentration of hydrogen peroxide (H(2) O(2) ). Cellular apoptosis was quantified by poly (ADP-ribose) polymerase (PARP) cleavage and flow cytometry.

RESULTS

H(2) O(2) induced apoptosis and phosphorylation of ATM, Chk2, and H2AX in LNCaP cells. An ATM inhibitor, Ku55933, reduced H(2) O(2) -induced apoptosis in LNCaP and 22Rv1 cells. Androgen treatments increased H(2) O(2) -induced activation of the DNA damage response and PARP cleavage, but not when the H(2) O(2) -treated cells were also treated with the anti-androgen flutamide. The ATM inhibitor Ku55933 inhibited androgen-induced phosphorylation of ATM and PARP cleavage.

CONCLUSIONS

DNA damage responses play important roles in the maintenance of the cell homeostasis in response to oxidative stress. Our results indicated that under oxidative stress androgen signaling may induce apoptosis by activating the DNA damage response.

Markers of field cancerization: proposed clinical applications in prostate biopsies

Field cancerization denotes the occurrence of genetic, epigenetic, and biochemical aberrations in structurally intact cells in histologically normal tissues adjacent to cancerous lesions. This paper tabulates markers of prostate field cancerization known to date and discusses their potential clinical value in the analysis of prostate biopsies, including diagnosis, monitoring progression during active surveillance, and assessing efficacy of presurgical neoadjuvant and focal therapeutic interventions.

Oxidatively induced DNA damage: mechanisms, repair and disease

Endogenous and exogenous sources cause oxidatively induced DNA damage in living organisms by a variety of mechanisms. The resulting DNA lesions are mutagenic and, unless repaired, lead to a variety of mutations and consequently to genetic instability, which is a hallmark of cancer. Oxidatively induced DNA damage is repaired in living cells by different pathways that involve a large number of proteins. Unrepaired and accumulated DNA lesions may lead to disease processes including carcinogenesis. Mutations also occur in DNA repair genes, destabilizing the DNA repair system. A majority of cancer cell lines have somatic mutations in their DNA repair genes. In addition, polymorphisms in these genes constitute a risk factor for cancer. In general, defects in DNA repair are associated with cancer. Numerous DNA repair enzymes exist that possess different, but sometimes overlapping substrate specificities for removal of oxidatively induced DNA lesions. In addition to the role of DNA repair in carcinogenesis, recent evidence suggests that some types of tumors possess increased DNA repair capacity that may lead to therapy resistance. DNA repair pathways are drug targets to develop DNA repair inhibitors to increase the efficacy of cancer therapy. Oxidatively induced DNA lesions and DNA repair proteins may serve as potential biomarkers for early detection, cancer risk assessment, prognosis and for monitoring therapy. Taken together, a large body of accumulated evidence suggests that oxidatively induced DNA damage and its repair are important factors in the development of human cancers. Thus this field deserves more research to contribute to the development of cancer biomarkers, DNA repair inhibitors and treatment approaches to better understand and fight cancer.

Antioxidants for prostate cancer chemoprevention: challenges and opportunities

Extensive research has led to the firm conclusion that antioxidants protect cells from damage caused by oxidative stress and its associated pathological conditions including inflammation. It has also been established that inflammation is a precursor in neoplastic transformation of the prostate. Although, a vast body of experimental and clinical evidence shows efficacy of antioxidants as preventive strategies for prostate cancer, there is a lack of consistent agreement in outcomes especially from recent large-scale randomized clinical trials. Despite these concerns, our understanding of the preventive mechanisms as well as clinical efficacy and safety data indicate that novel antioxidant therapeutics still hold great promise for prostate cancer chemoprevention. We propose that for effective use of antioxidants for prostate cancer prevention, further high impact translational research is needed with special attention on selecting those patients who will benefit from such intervention. Therefore, it is important to validate predictive biomarkers from successful trials and combine this with knowledge of preclinical characterization of antioxidants (and combinations) that will eventually facilitate the development of 'personalized prostate cancer chemoprevention'. In this review, we briefly describe some common and emerging antioxidants that have shown benefits in preclinical and clinical settings. Above all, we focus on summarizing the progress we made thus far in prostate cancer chemoprevention using antioxidants, the heightened interest and challenges in the future.

Malignant transformation and stromal invasion from normal or hyperplastic tissues: true or false?

Carcinogenesis is believed to be a multi-step process, progressing sequentially from normal to hyperplastic, to in situ, and to invasive stages. A number of studies, however, have detected malignancy-associated alterations in normal or hyperplastic tissues. As the molecular profile and clinical features of these tissues have not been defined, the authors invited several well-recognized pathologist, oncologists, biologist, surgeons, and molecular biologist to offer their opinion on: (1) whether these tissues belong to a previously unrevealed malignant entity or focal alterations with no significant consequence? (2) whether these alterations are linked to early onset of cancer or cancer of unknown primary site, and (3) how to further define these lesions?

Metastasis Update: Human Prostate Carcinoma Invasion via Tubulogenesis

This paper proposes that human prostate carcinoma primarily invades as a cohesive cell collective through a mechanism similar to embryonic tubulogenesis, instead of the popular epithelial-mesenchymal transformation (EMT) model. Evidence supporting a tubulogenesis model is presented, along with suggestions for additional research. Additionally, observations documenting cell adhesion molecule changes in tissue and stromal components are reviewed, allowing for comparisons between the current branching morphogenesis models and the tubulogenesis model. Finally, the implications of this model on prevailing views of therapeutic and diagnostic strategies for aggressive prostatic disease are considered.

Spectral signatures of colonic malignancies in the mid-infrared region: from basic research to clinical applicability

The process of carcinogenesis in the colon progresses through several overlapping stages, making the evaluation process challenging, as well as subjective. Owing to the complexity of colonic tissues and the search for a technique that is rapid and foolproof for precise grading and evaluation of biopsies, many spectroscopic techniques have been evaluated in the past few decades for their efficiency and clinical compatibility. Fourier-transform infrared spectroscopy, being quantitative and objective, has the capacity for automation and relevance to cancer diagnosis. This article highlights investigations on the application of Fourier-transform infrared spectroscopy (particularly microscopy) in colon cancer diagnosis and parallel developments in data analysis techniques for the characterization of spectral signatures of malignant tissues in the colon.

Tumor indicating normal tissue could be a new source of diagnostic and prognostic markers for prostate cancer

IMPORTANCE OF THE FIELD

Prostate cancer is a common and multifocal disease but the diagnostic methods available are unsatisfactory. Most tumors present are of low malignant potential, whereas others are highly aggressive. At present, imaging cannot be used to guide tissue biopsies safely towards the most aggressive tumor present. To handle this problem multiple needle biopsies are taken. The biopsies often contain only normal prostate tissue, and even if the tumor is sampled it is not known whether a more aggressive cancer is present elsewhere in the organ. If changes in the normal tissue indicate the presence and nature of tumors, this information could be used to improve diagnostics and prognostics of prostate cancer.

AREAS COVERED IN THIS REVIEW

Current evidence that the tumor-adjacent morphologically normal prostate tissue is not completely normal is reviewed, and that this tissue, named tumor indicating normal tissue (TINT) by the authors, can be used to diagnose prostate cancer.

WHAT THE READER WILL GAIN

The reader will understand that tumors need to affect their surroundings in order to grow and metastasize and that the normal prostate tissue is therefore tinted by the presence and nature of cancer and that this knowledge can be used to develop new diagnostic and prognostic markers.

TAKE HOME MESSAGE

TINT changes could probably, when more rigorously defined and validated, be used to diagnose and prognosticate prostate cancer.

The antioxidant effects of genistein are associated with AMP-activated protein kinase activation and PTEN induction in prostate cancer cells

Epidemiological evidence suggests a lower incidence of prostate cancer in Asian countries, where soy products are more frequently consumed than in Western countries, indicating that isoflavones from soy have chemopreventive activities in prostate cells. Here, we tested the effects of the soy isoflavone genistein on antioxidant enzymes in DU145 prostate cancer cells. Genistein significantly decreased reactive oxygen species levels and induced the expression of the antioxidant enzymes manganese (Mn) superoxide dismutase (SOD) and catalase, which were associated with AMP-activated protein kinase (AMPK) and phosphatase and tensin homolog deleted from chromosome 10 (PTEN) pathways. The induced expression of catalase, MnSOD, and PTEN were attenuated by pretreatment with a pharmacological inhibitor for AMPK, indicating the effects of genistein primarily depend on AMPK. Furthermore, PTEN is essential for genistein activity, as shown by PTEN transfection in PTEN-deficient PC3 cells. Thus, genistein induces antioxidant enzymes through AMPK activation and increased PTEN expression.

Radiosensitivity and repair kinetics of gamma-irradiated leukocytes from sporadic prostate cancer patients and healthy individuals assessed by alkaline comet assay

BACKGROUND

Impaired DNA repair mechanism is one of the main causes of tumor genesis. Study of intrinsic radiosensitivity of cancer patients in a non-target tissue (e.g. peripheral blood) might show the extent of DNA repair deficiency of cells in affected individuals and might be used a predictor of cancer predisposition.

METHODS

Initial radiation-induced DNA damage (ratio of Tail DNA/Head DNA), dose-response curves and kinetics of DNA repair in leukocytes from healthy volunteers and prostate cancer patients were assessed using alkaline comet assay after exposure to 60Co gamma rays.

RESULTS

Results showed that higher levels of baseline and gamma rays induced DNA damage in leukocytes of prostate cancer cases than in controls. A similar dose response was obtained for both groups. After a repair time of 24 h following in vitro irradiation, samples from the healthy individuals showed no residual DNA damage in their leukocytes, whereas prostate cancer patients revealed more than 20 percent. Although similar initial radiosensitivity was observed for both groups, the repair kinetics of radiation induced DNA damage of leukocytes from prostate cancer cases and healthy subjects were statistically different.

CONCLUSION

These results support the hypothesis that men affected by prostate cancer may have a constitutional genomic instability.

Investigation on the Interactions of NiCR and NiCR-2H with DNA

We report here a biophysical and biochemical approach to determine the differences in interactions of NiCR and NiCR-2H with DNA. Our goal is to determine whether such interactions are responsible for the recently observed differences in their cytotoxicity toward MCF-7 cancer cells. Viscosity measurement and fluorescence displacement titration indicated that both NiCR and NiCR-2H bind weakly to duplex DNA in the grooves. The coordination of NiCR-2H with the N-7 of 2'-deoxyguanosine 5'-monophosphate (5'-dGMP) is stronger than that of NiCR as determined by (1)H NMR. NiCR-2H, like NiCR, can selectively oxidize guanines present in distinctive DNA structures (e.g., bulges), and notably, NiCR-2H oxidizes guanines more efficiently than NiCR. In addition, UV and (1)H NMR studies revealed that NiCR is oxidized into NiCR-2H in the presence of KHSO(5) at low molar ratios with respect to NiCR (</=4).

A seemingly most effective target for early detection and intervention of prostate tumor invasion

This commentary proposes that budding tumor cell projections from focally disrupted tumor capsules represent a most effective target for early detection and intervention of prostate tumor invasion. The rationale, supporting data, and clinical applications of the hypothesis are discussed.

Current prostate biopsy protocols cannot reliably identify patients for focal therapy: correlation of low-risk prostate cancer on biopsy with radical prostatectomy findings

Focal therapy appears to be an attractive alternative approach for patients with localized prostate cancer (PCa). Identifying suitable candidates is crucial to the success of focal therapy. Currently, standard transrectal ultrasound (TRUS)-guided prostate biopsy remains the widespread approach to evaluate patient suitability. In this study, we evaluated the ability of current biopsy protocols to predict cancer characteristics in radical prostatectomy (RP) specimens. We reviewed 4437 cases from 2000 to 2008 in our PowerPath database, and identified 158 patients with low-risk cancer, defined as a pre-biopsy PSA level <or= 10 ng/mL, unilateral, low tumor volume (<or=5%) and low to intermediate Gleason score (GS<or=6) on first positive prostate biopsy. The pathological characteristics of subsequent RP specimens were reviewed. We found that, of 158 patients with these criteria, 117 (74%) had bilateral cancer, 49 (31%) had increased tumor volume (>or= 10%), and 46 (29%) were upgraded to GS >or= 7 at RPs. When patients were stratified by total biopsy core numbers, extended biopsy core protocols were not significantly more reliable in identifying unilateral and low volume prostate cancer patients. One core positive on biopsy was not significantly superior to > 2 positive cores in predicting unilateral, low volume, low stage cancer at prostatectomy. These findings indicate that current standard prostate biopsy protocols have limited accuracy in identifying candidates for focal therapy.

Technologies for localization and diagnosis of prostate cancer

The gold standard for detecting prostate cancer (PCa), systematic biopsy, lacks sensitivity as well as grading accuracy. PSA screening leads to over-treatment of many men, and it is unclear whether screening reduces PCa mortality. This review provides an understanding of the difficulties of localizing and diagnosing PCa. It summarizes recent developments of ultrasound (including elastography) and MRI, and discusses some alternative experimental techniques, such as resonance sensor technology and vibrational spectroscopy. A comparison between the different methods is presented. It is concluded that new ultrasound techniques are promising for targeted biopsy procedures, in order to detect more clinically significant cancers while reducing the number of cores. MRI advances are very promising, but MRI remains expensive and MR-guided biopsy is complex. Resonance sensor technology and vibrational spectroscopy have shown promising results in vitro. There is a need for large prospective multicentre trials that unambiguously prove the clinical benefits of these new techniques.

Discrimination of base differences in oligonucleotides using mid-infrared spectroscopy and multivariate analysis

Attenuated total reflection Fourier transform-infrared (ATR-FTIR) spectroscopy was employed to interrogate a panel of simple oligonucleotides designed to contain various base differences; combined with subsequent multivariate analysis, we set out to determine whether the specificity of this approach would point to a novel means for mutation detection. Oligonucleotides were designed that were 15 bases in length and contained various combinations of purines (adenine, guanine) or pyrimidines (cytosine, thymine). These were applied to 1 cm x 1 cm low-E reflective glass slides, and triplicate samples were interrogated using ATR-FTIR spectroscopy. Per oligonucleotide sample, 10 independent spectral acquisitions were obtained. Prior to multivariate analysis, infrared spectra were baseline-corrected and vector normalized over the 1750-760 cm(-1) region specific to the chemical bonds of organic molecules. Spectral categories were then analyzed using principal component analysis (PCA) followed by linear discriminant analysis (LDA). Scores plots revealed that PCA-LDA clearly segregated different oligonucleotide sequences, even in the presence of a single base difference. Loadings plots confirmed the chemical entities associated with distinguishing base differences. These results suggest that mid-IR spectroscopy might have future roles in interrogating polymorphic forms of a DNA template.

Evidence for field cancerization of the prostate

BACKGROUND

Field cancerization, which is not yet well-characterized in the prostate, occurs when large areas of an organ or tissue surface are affected by a carcinogenic insult, resulting in the development of multi-focal independent premalignant foci and molecular lesions that precede histological change.

METHODS

Herein, we review the cumulative body of evidence concerning field effects in the prostate and critically evaluate the methods available for the identification and validation of field effect biomarkers. Validated biomarkers for field effects have an important role to play as surrogate endpoint biomarkers in Phase II prevention trials and as clinical predictors of cancer in men with negative biopsies.

RESULTS

Thus far, field effects have been identified involving nuclear morphometric changes, gene expression, protein expression, gene promoter methylation, DNA damage and angiogenesis. In addition to comparing cancer-adjacent benign tissue to more distant areas or to "supernormal" tissue from cancer-free organs, investigators can use a nested case-control design for negative biopsies that offers a number of unique advantages.

CONCLUSIONS

True carcinogenic field effects should be distinguished from secondary responses of the microenvironment to a developing tumor, although the latter may still lead to useful clinical prediction tools. Prostate 69: 1470-1479, 2009. (c) 2009 Wiley-Liss, Inc.

Correlated alterations in prostate basal cell layer and basement membrane

Our recent studies revealed that focal basal cell layer disruption (FBCLD) induced auto-immunoreactions represented a contributing factor for human prostate tumor progression and invasion. As the basement membrane surrounds and attaches to the basal cell layer, our current study assessed whether FBCLD would impact the physical integrity of the associated basement membrane. Paraffin sections from 25-human prostate tumors were subjected to double immunohistochemistry to simultaneously elucidate the basal cell layer and the basement membrane with corresponding biomarkers. The physical integrity of the basement membrane overlying FBCLD was examined to determine the extent of correlated alterations. Of a total of 89 FBCLD encountered, 76 (85 %) showed correlated alterations in the overlying basement membrane, which included distinct focal disruptions or fragmentations. In the remaining 13 (15%) FBCLD, the overlying basement membrane showed significant attenuation or reduction of the immunostaining intensity. The basement membrane in all or nearly all ducts or acini with p63 positive basal cells was substantially thicker and more uniform than that in ducts or acini without p63 positive basal cells, and also, a vast majority of the focal disruptions occurred near basal cells that lack p63 expression. These findings suggest that focal disruptions in the basal cell layer and alterations in the basement membrane are correlated events and that the physical and functional status of the basal cells could significantly impact the physical integrity of the overlying basement membrane. As the degradation of both the basal cell layer and the basement membrane is a pre-requisite for prostate tumor invasion or progression, ducts or acini with focally disrupted basal cell layer and basement membrane are likely at greater risk to develop invasive lesions. Thus, further elucidation of the specific molecules and mechanism associated with these events may lead to the development of a more effective alternative for repeat biopsy to monitor tumor progression and invasion.

Aberrant p63 and WT-1 expression in myoepithelial cells of pregnancy-associated breast cancer: implications for tumor aggressiveness and invasiveness

Our recent studies revealed that focal alterations in breast myoepithelial cell layers significantly impact the biological presentation of associated epithelial cells. As pregnancy-associated breast cancer (PABC) has a significantly more aggressive clinical course and mortality rate than other forms of breast malignancies, our current study compared tumor suppressor expression in myoepithelial cells of PABC and non-PABC, to determine whether myoepithelial cells of PABC may have aberrant expression of tumor suppressors. Tissue sections from 20 cases of PABC and 20 cases of stage, grade, and age matched non-PABC were subjected to immunohistochemistry, and the expression of tumor suppressor maspin, p63, and Wilms' tumor 1 (WT-1) in calponin positive myoepithelial cells were statistically compared. The expression profiles of maspin, p63, and WT-1 in myoepithelial cells of all ducts encountered were similar between PABC and non-PABC. PABC, however, displayed several unique alterations in terminal duct and lobular units (TDLU), acini, and associated tumor tissues that were not seen in those of non-PABC, which included the absence of p63 and WT-1 expression in a vast majority of the myoepithelial cells, cytoplasmic localization of p63 in the entire epithelial cell population of some lobules, and substantially increasing WT-1 expression in vascular structures of the invasive cancer component. All or nearly all epithelial cells with aberrant p63 and WT-1 expression lacked the expression of estrogen receptor and progesterone receptor, whereas they had a substantially higher proliferation index than their counterparts with p63 and WT-1 expression. Hyperplastic cells with cytoplasmic p63 expression often adjacent to, and share a similar immunohistochemical and cytological profile with, invasive cancer cells. To our best knowledge, our main finings have not been previously reported. Our findings suggest that the functional status of myoepithelial cells may be significantly associated with tumor aggressiveness and invasiveness.

Oxidative stress-related aging: A role for prostate cancer?

Prostate cancer has the highest prevalence of any non-cutaneous cancer in the human body and essentially all men with circulating androgens will develop microscopic prostate cancer if they live long enough. Aging, considered as an impairment of body functions over time, caused by the accumulation of molecular damage in DNA, proteins and lipids, is also characterized by an increase in intracellular oxidative stress due to the progressive decrease of the intracellular ROS scavenging. The aging damage may eventually appear in age-related health issues, which have a significant impact on the independence, general well-being and morbidity of the elderly. The association of aging with prostate cancer is undisputable as well as the association of aging with oxidative stress. Nevertheless, supportive evidence linking an increase in oxidative stress with prostate cancer is still scarce. This review is a comprehensive, literature-based analysis of the association of human prostate cancer with oxidative stress. The objective was to examine the involvement of reactive oxygen species in the mechanisms of prostatic carcinogenesis since the understanding of risk factors for prostate cancer has practical importance for public health, genetic and nutritional education, and chemoprevention.