Steroid hormone regulation of prostate-specific antigen gene expression in breast cancer

Systematic Multi-Omics Investigation of Androgen Receptor Driven Gene Expression and Epigenetics changes in Prostate Cancer

Background

Prostate cancer, a common malignancy, is driven by androgen receptor (AR) signaling. Understanding the function of AR signaling is critical for prostate cancer research.

Methods

We performed multi-omics data analysis for the AR+, androgen-sensitive LNCaP cell line, focusing on gene expression (RNAseq), chromatin accessibility (ATACseq), and transcription factor binding (ChIPseq). High-quality datasets were curated from public repositories and processed using state-of-the-art bioinformatics tools.

Results

Our analysis identified 1004 up-regulated and 707 down-regulated genes in response to androgen deprivation therapy (ADT) which diminished AR signaling activity. Gene-set enrichment analysis revealed that AR signaling influences pathways related to neuron differentiation, cell adhesion, P53 signaling, and inflammation. ATACseq and ChIPseq data demonstrated that as a transcription factor, AR primarily binds to distal enhancers, influencing chromatin modifications without affecting proximal promoter regions. In addition, the AR-induced genes maintained higher active chromatin states than AR-inhibited genes, even under ADT conditions. Furthermore, ADT did not directly induce neuroendocrine differentiation in LNCaP cells, suggesting a complex mechanism behind neuroendocrine prostate cancer development. In addition, a publicly available online application LNCaP-ADT (https://pcatools.shinyapps.io/shinyADT/) was launched for users to visualize and browse data generated by this study.

Conclusion

This study provides a comprehensive multi-omics dataset, elucidating the role of AR signaling in prostate cancer at the transcriptomic and epigenomic levels. The reprocessed data is publicly available, offering a valuable resource for future prostate cancer research.

Development of male breast cancer in a patient with prostate cancer during androgen deprivation therapy

INTRODUCTION

Male breast cancer accounts for <1% of all breast cancer. We report a patient with prostate cancer during hormone therapy who developed breast cancer.

CASE PRESENTATION

An 88-year-old male underwent androgen deprivation therapy for prostate cancer and developed an induration in the left breast 7 years after the start of treatment. After close examination, he was diagnosed with left breast cancer with lymph node metastasis. The prostate cancer was stable in a hormone-sensitive state. Left mastectomy was performed and the pathological diagnosis was invasive ductal carcinoma.

DISCUSSION

In addition to our patient, seven patients who developed breast cancer during hormone therapy for prostate cancer were examined. Five of six patients had stage II or above, and four patients had lymph node metastases. Although local breast symptoms are frequently observed as adverse effects of hormone therapy, caution is warranted regarding male breast cancer.

Prostate-Specific Antigen and Testosterone Levels as Biochemical Indicators of Cognitive Function in Prostate Cancer Survivors and the Role of Diabetes

Prostate cancer (PC) is one of the most common malignancies in men. The increase in the number of PC survivors is associated with many problems including cognitive impairment. Early detection of such problems facilitates timely protective intervention. This study examined the association between prostate-specific antigen (PSA) or testosterone (T) levels and cognitive function in patients undergoing radical prostatectomy. Such a correlation could help identify patient groups at risk of cognitive impairment. Participants underwent clinical (demographic data, medical history, physical examination, and blood analyses) and neuropsychological assessment (cognitive test battery). Preoperative PSA or T levels were not associated with cognitive function. However, long-term follow-up after prostatectomy showed a strong correlation between PSA levels and the results of verbal memory and executive function tests. A trend toward significance was also observed for visuospatial memory. The levels of free T and total T were not correlated with cognitive function. Only the levels of free T after hormonal treatment were significantly correlated with executive functions. Comorbid diabetes affected these correlations. In conclusion, PSA levels at a distant postoperative time and free T level after hormonal treatment may be biomarkers of cognitive function.

Secreted indicators of androgen receptor activity in breast cancer pre-clinical models

PURPOSE

Accumulating evidence has attracted attention to the androgen receptor (AR) as a biomarker and therapeutic target in breast cancer. We hypothesized that AR activity within the tumor has clinical implications and investigated whether androgen responsive serum factors might serve as a minimally invasive indicator of tumor AR activity.

METHODS

Based on a comprehensive gene expression analysis of an AR-positive, triple negative breast cancer patient-derived xenograft (PDX) model, 163 dihydrotestosterone (DHT)-responsive genes were defined as an androgen responsive gene set. Among them, we focused on genes that were DHT-responsive that encode secreted proteins, namely KLK3, AZGP1 and PIP, that encode the secreted factors prostate specific antigen (PSA), zinc-alpha-2-glycoprotein (ZAG) and prolactin induced protein (PIP), respectively. Using AR-positive breast cancer cell lines representing all breast cancer subtypes, expression of candidate factors was assessed in response to agonist DHT and antagonist enzalutamide. Gene set enrichment analysis (GSEA) was performed on publically available gene expression datasets from breast cancer patients to analyze the relationship between genes encoding the secreted factors and other androgen responsive gene sets in each breast cancer subtype.

RESULTS

Anti-androgen treatment decreased proliferation in all cell lines tested representing various tumor subtypes. Expression of the secreted factors was regulated by AR activation in the majority of breast cancer cell lines. In GSEA, the candidate genes were positively correlated with an androgen responsive gene set across breast cancer subtypes.

CONCLUSION

KLK3, AZGP1 and PIP are AR regulated and reflect tumor AR activity. Further investigations are needed to examine the potential efficacy of these factors as serum biomarkers.

Contraceptive progestins with androgenic properties stimulate breast epithelial cell proliferation

Hormonal contraception exposes women to synthetic progesterone receptor (PR) agonists, progestins, and transiently increases breast cancer risk. How progesterone and progestins affect the breast epithelium is poorly understood because we lack adequate models to study this. We hypothesized that individual progestins differentially affect breast epithelial cell proliferation and hence breast cancer risk. Using mouse mammary tissue ex vivo, we show that testosterone-related progestins induce the PR target and mediator of PR signaling-induced cell proliferation receptor activator of NF-κB ligand (Rankl), whereas progestins with anti-androgenic properties in reporter assays do not. We develop intraductal xenografts of human breast epithelial cells from 36 women, show they remain hormone-responsive and that progesterone and the androgenic progestins, desogestrel, gestodene, and levonorgestrel, promote proliferation but the anti-androgenic, chlormadinone, and cyproterone acetate, do not. Prolonged exposure to androgenic progestins elicits hyperproliferation with cytologic changes. Androgen receptor inhibition interferes with PR agonist- and levonorgestrel-induced RANKL expression and reduces levonorgestrel-driven cell proliferation. Thus, different progestins have distinct biological activities in the breast epithelium to be considered for more informed choices in hormonal contraception.

Plasma level of prostate related-antigen peptide-reactive IgG is a prognostic factor of patients with breast cancer treated with personalized peptide vaccines

The present study assessed plasma IgG in patients with metastatic recurrent breast cancer (mrBC) that is reactive to various T-cell epitope peptides of prostate-related antigens (PRAs), such as prostate-specific antigen, prostate-specific membrane antigen and prostate acid phosphatase. Patients were treated with personalized peptide vaccines (PPVs) which were selected and administered from a panel of candidate peptides based on human leukocyte antigen-types and prevaccination IgG levels to each peptide. The peptide panel consisted of 27 cytotoxic T-lymphocyte-epitope peptides derived from tumor-associated antigens, not including PRA. PRA peptides and peptide panels were retrospectively analyzed in 77 PPV-treated patients. The results revealed that PRA reactive IgG levels were increased after vaccination in 31 of the 97 patients included in the present study. Although there was no significant association between anti-PRA peptide levels and progression-free survival (PFS) or overall survival, anti-PRA peptide levels were significantly associated with PFS (P=0.009) in estrogen-receptor positive (ER+) patients with cancer. The results suggested that plasma anti-PRA IgG levels may be a useful prognostic marker for monitoring PPVs, particularly for ER+ patients with mrBC (trial registration no. from the UMIN Clinical Trials Registry, UMIN000001844).

Novel case of androgen receptor-positive cancer of unknown primary without serum prostate-specific antigen elevation that became progression free in the long term after primary combined androgen blockade

INTRODUCTION

The prognosis of cancer of unknown primary is very poor. Such a prognosis can be improved by characterizing primary characteristics and developing tailored site-specific therapy, especially for androgen receptor-positive adenocarcinoma. However, in such cases without elevated prostate-specific antigen, the efficacy of androgen deprivation therapy is unclear.

CASE PRESENTATION

Herein, we report a case that presented with a retroperitoneal cancer of unknown primary that was confirmed as an androgen receptor-positive adenocarcinoma without prostate-specific antigen elevation. Pelvic magnetic resonance imaging did not reveal any suspicious cancer lesions in the prostate. Furthermore, malignant cells were not present in a prostate biopsy specimen. In spite of the prostate-specific antigen level, on the basis of immunohistochemical analyses, including NKX3.1, the patient was first treated with androgen deprivation therapy, leading to long-term progression-free survival.

CONCLUSION

Early androgen deprivation therapy based on immunohistochemical analyses might lead to a good outcome in androgen receptor-positive adenocarcinoma cancer of unknown primary patients regardless of prostate-specific antigen level.

Prostatic-specific antigen (PSA) levels in patients with polycystic ovary syndrome (PCOS): a meta-analysis

Purpose

The polycystic ovary syndrome (PCOS) is a reproductive endocrine disorder, clinically characterized by oligo-ovulation/chronic anovulation, menstrual irregularities, hyperandrogenism (such as hirsutism, acne), hyperinsulinemia, and obesity. Prostatic-specific antigen (PSA) has been identified as a potential new marker in PCOS women. Although the precise role of PSA in PCOS patients still remains undetermined, PSA might serve as a useful clinical marker and might even represent a new diagnostic criterion of hyperandrogenemia in females of PCOS.

Methods

A meta-analysis was performed in the study to identify the association between the polycystic ovary syndrome and prostatic-specific antigen. To identify eligible original articles, we searched a range of computerized databases, including Medline via PubMed, EMBASE, CNKI and Web of Science with a systematic searching strategy. The characteristics of each study and standard mean differences (SMD) with corresponding confidence intervals (CIs) were calculated and subgroup analysis was performed to analyze heterogeneity.

Results

A total of 532 patients from seven articles were included in the meta-analysis. We identified a significant relationship between polycystic ovary syndrome and prostatic-specific antigen, with a pooled SMD of 0.81 (95% CI: 0.58 to 1.04; P < 0.01). The pooled data were calculated with the random-effects model as a moderate significant heterogeneity was found among the studies.

Conclusions

The meta-analysis suggested that there was a significant association between the polycystic ovary syndrome and prostatic-specific antigen and we should not ignore the role of PSA in the PCOS patients in clinical.

Increased free prostate specific antigen serum levels in Alzheimer's disease, correlation with Cognitive Decline

BACKGROUND/AIMS

Prostate specific antigen (PSA) is regulated by steroid hormones, such as testosterone, the serum levels of which are altered in patients with Alzheimer's disease (AD).This pilot study compared serum levels of the free (f) PSA between AD, mild cognitive impairment (MCI), and control subjects, and evaluated the relationship between fPSA serum levels and cognitive assessment tests and neuroimaging data. In addition, in a subgroup of AD patients, we correlated fPSA serum levels with the existing data on serum levels of amyloid-beta (Aβ), and iron-related proteins, including hepcidin and ferritin.

METHODS

Frozen serum samples from the Oregon Tissue Bank were used to measure serum levels of fPSA using enzyme-linked immunosorbent assay.

RESULTS

fPSA serum levels calculated as median ± SD were higher in AD males (663.6 ± 821.0 pg/ml) compared to control males (152.0 ± 207.0 pg/ml), p = 0.003. A similar Pattern emerged when comparing MCI males (310.7 ± 367.0 pg/ml) to control males (P = 0.02). Correlation studies showed a significant association between fPSA and CDR (r = 0.56, P = 0.006) and CDR-SOB (r = 0.54, P = 0.009) in AD males.

CONCLUSION

Additional studies in a larger cohort are required for determining whether fPSA can be used as biomarker of AD disease progression and whether it has the potential to identify male subjects at risk of AD dementia.

Androgen receptor: A promising therapeutic target in breast cancer

Breast cancer (BCa) is the second most common cancer worldwide and the most prevalent cancer in women. The majority of BCa cases are positive (+) for the estrogen receptor (ER⁺, 80%) and progesterone receptor (PR⁺, 65%). Estrogen and progesterone hormones are known to be involved in cancer progression, and thus hormonal deprivation is used as an effective treatment for ER⁺PR⁺ BCa subtypes. However, some ER⁺PR⁺ BCa patients develop resistance to such therapies. Meanwhile, chemotherapy is the only available treatment for ER^-PR^- BCa tumors. Another hormone receptor known as the androgen receptor (AR) has also been found to be widely expressed in human breast carcinomas. However, the mechanisms of AR and its endogenous androgen ligands is not well-understood in BCa and its biological role in this hormone-related disease remains unclear. In this review, we aim to address the importance of the AR in BCa diagnosis and prognosis, current AR-targeting approaches in BCa, and the potential for AR-downstream molecules to serve as therapeutic targets.

Free/Total Serum Prostate-Specific Antigen Ratio in Women with Colorectal Cancer Has Prognostic Significance

PURPOSE

The presence of prostate-specific antigen (PSA) in colon cancer tissues has been shown, but its clinical significance has not been known yet in colorectal cancer patients. We investigated the prognostic significance of percent free PSA value (free PSA/total PSA × 100) in female patients with colorectal cancer.

METHODS

The serum concentrations of total and free PSA were measured by solid-phase two-site immunoradiometric assay in 184 patients.

RESULTS

The cancer-specific survival (CSS) of patients with percent free PSA value ≥35 was significantly better compared to that of patients with percent free PSA value <35 (CSS rate was 82.9 and 55.5 %, respectively; log-rank x² = 8135, p = 0.004). In multivariate Cox analysis, this percent free PSA threshold value had independent prognostic significance (relative risk 0.27, 95 % confidence interval 0.11-0.64, p = 0.003).

CONCLUSION

Percent free PSA value, calculated by serum total and free PSA levels, has prognostic significance in women with colorectal cancer. The studies with larger patient series, utilizing ultrasensitive PSA assays whose lowest detection limit is lower, are required for a clearer understanding of this issue.

Study of Serum Total PSA and Free PSA as an Oncological Marker in Breast Tumour

INTRODUCTION

Breast Cancer (BC) cases are rising alarmingly all over the world and India is not an exception. This rising trend is due to an increased age at first child birth, decreased breast feeding, and the changing lifestyle mostly in urban India. With the advent of more sensitive methodologies and research works in this field, it has been suggested that Prostate Specific Antigen (PSA) plays an important role in the pathogenesis of breast cancer besides other established tumour markers.

AIM

To study the molecular forms of PSA-total and free PSA in benign and malignant tumours and to analyse their association with the tumour burden.

MATERIALS AND METHODS

The present study was conducted in collaboration with Gauhati Medical College and Hospital and Dr B Borooah Cancer Institute, Guwahati, Assam, India. Women in the age group of 18-65 years with recently diagnosed tumour (benign/malignant) in the breast were included in the study. Women taking Oral Contraceptive Pill (OCP), hormone replacement therapy, with past/present history of gynaecological/other malignancy and chronic endocrine disease like diabetes, thyroid disorders were excluded. The case group comprised of 50 female subjects with newly diagnosed Benign Breast Disease (BBD) and 50 subjects with BC, while 50 age matched healthy females without any signs and symptoms of breast discomfort were included in the control group. Laboratory tests done were Serum Total PSA (TPSA), Free PSA (FPSA), Fasting Blood Glucose (FBS), serum urea, serum creatinine and fasting lipid profile. TPSA and FPSA was measured again in both the test groups after 10-14 days of surgery/therapy.

RESULTS

A fall in postoperative value of total and free PSA in BC case group was noticed. In Grade I tumours the mean value of total PSA (1.813 ng/ml) and free PSA (1.149 ng/ml) were higher than those with Grade III tumours (TPSA-1.07 ng/ml and FPSA-1.002 ng/ml). Mean value of Fasting Blood Sugar (FBG), total cholesterol and Low Density Lipoprotein (LDL) in BC case group was higher than the control group.

CONCLUSION

From the study, we can conclude PSA as a possible new marker for diagnosis and prognosis of BC.

Putative functions of tissue kallikrein-related peptidases in vaginal fluid

Cervical-vaginal fluid (CVF) is a complex biological fluid that hydrates the mucosa of the lower female reproductive system. In-depth proteomic and biochemical studies on CVF have revealed that it contains large amounts of endogenous proteases and protease inhibitors, including an abundance of several members of the tissue kallikrein-related peptidase (KLK) family. Despite their ubiquitous presence in human tissues and fluids, KLK expression levels vary considerably, with maximum expression observed in reproduction-related tissues and fluids. The roles of KLKs in the lower female reproductive system are not fully understood. The activation of KLKs in CVF is dependent on pH and various modes of KLK regulation in the vagina exist. KLKs have been postulated to have roles in physiological functions related to antimicrobial processes, vaginal and cervical epithelial desquamation, sperm transport, and the processing of fetal membranes as observed in preterm premature rupture of membranes. Increased understanding of the functional roles of KLKs in the lower female reproductive system could lead to new diagnostic and therapeutic modalities for conditions such as vaginal infections and vaginal atrophy.

Is Serum Prostate-specific Antigen a Diagnostic Marker for Benign and Malignant Breast Tumors in Women

BACKGROUND

Breast cancer is the most common cancer in women. Prostrate-specific antigen (PSA) is a marker of prostate gland malignancy which has been considered in cases with breast cancer in recent years. The goal of this study was to determine total and free PSA levels in cases with malignant and benign breast lesions.

METHOD

Ninety women with histological proved malignant breast masses and 90 with benign breast masses were enrolled. Total and free PSA levels along with histological grade and conditions of vascular and perinural invasion, status of hormonal tumor receptors, immune-histo-chemistry markers recorded for all cases. Total and free PSA levels were assessed after treatment in cases with malignant masses.

RESULTS

Total and free PSA levels were significantly higher in cases with malignant masses. The best cut off point for total PSA to differentiate benign and malignant masses was 0.31 and the best cut off point for free PSA to differentiate benign and malignant masses was 0.19. After treatment, mean free PSA level was significantly lower than free PSA before treatment (0.23 vs 0.3, p<0.001).

CONCLUSION

Serum PSA level could be applied for differentiating benign and malignant breast masses.

Expression of androgen receptor and its association with estrogen receptor and androgen receptor downstream proteins in normal/benign breast luminal epithelium

The androgen receptor (AR) is strongly expressed in the majority of breast carcinomas, but its role in breast hormonal carcinogenesis is not clear. We believe a better knowledge of the biology of normal/benign breast tissue will be the key to understanding this process. Using standard immunohistochemical staining on consecutive sections and dual immunohistochemical labeling, we studied the expression pattern of AR and estrogen receptor (ER) in normal/benign breast luminal epithelial cells. We found that most of the AR-positive cells are also ER positive, about 10% of the cells are AR-positive only, whereas ER-positive only cells are uncommon, a distribution pattern of hormone receptor expression similar to what was revealed in invasive breast carcinomas. Whereas the expression of AR downstream proteins, such as prostate-specific antigen and gross cystic disease fluid protein, was either negative or unrelated to the AR status. We conclude that AR and ER expression status in invasive breast carcinomas reflects that of their progenitor cells in terminal duct lobular units. Our study did not reveal the expression of AR downstream proteins in normal/benign luminal epithelial cells at the regular immunohistochemistry level.

Is Serum Prostate-specific Antigen a Diagnostic Marker for Benign and Malignant Breast Tumors in Women?

BACKGROUND

Breast cancer is the most common cancer in women. Prostate-specific antigen (PSA) is a marker of prostate gland malignancy, which has been considered in cases with breast cancer in recent years. The goal of this study was to determine total and free PSA levels in cases with malignant and benign breast lesions.

METHODS

In this case-control study, ninety women with histological proved malignant breast masses and 90 with benign breast masses were enrolled. Total and free PSA levels along with Histological grade and conditions of vascular and perinural invasion, status of hormonal tumor receptors, immune-histo-chemistry markers recorded for all cases. Total and free PSA levels were assessed after treatment in cases with malignant masses.

RESULTS

Total and free PSA levels were significantly higher in cases with malignant masses. The best cut-off point for total PSA to differentiate benign and malignant masses was 0.31 with sensitivity and specificity of 100%, 100% (area under the curve [AUC] =1, P < 0.001) and the best cut-off point for free PSA to differentiate benign and malignant masses was 0.19 with sensitivity and specificity of 100% and 100% (AUC = 1, P < 0.001). After treatment, mean free PSA level was significantly lower than free PSA before treatment (0.23 ± 0.1 vs. 0.3 ± 0.08, P < 0.001).

CONCLUSIONS

Serum PSA level could be applied for differentiating benign and malignant breast masses.

Reconnoitring the status of prostate specific antigen and its role in women

Prostate specific antigen is considered to be a tumour marker having maximum utility and specificity for prostate cancer since decades. After the discovery of methods to quantify different molecular fractions of prostate specific antigen (PSA), its usefulness in diagnosing early prostate cancer cases has increased tremendously. The "specificity" of PSA, is now challenged by many studies which proved that PSA, once believed to be secreted exclusively by prostatic epithelium, is also present in females. The exact biological role of extraprostatic PSA is still debatable though many theories substantiated by in vitro evidence has been put forward. With the advent of ultrasensitive analytical techniques, PSA is now quantifiable in female serum in its various molecular forms and this has led to many assumptions of it being useful as a marker in female breast cancers. In a similar scenario to prostate cancer, the ratio of free to total PSA is shown to be useful in detecting early breast cancer cases. It is also shown to be a good prognostic indicator and a predictor of response to therapy and recurrence. Apart from its role in breast cancer, it has been advocated to be a marker of hyper androgenic states in women like hirsutism and polycystic ovarian syndrome. Conflicting reports regarding the role of extra prostatic PSA is accumulating but it has been proven beyond doubt that PSA is no longer specific and confined to prostate gland. Various studies have registered that PSA is an ubiquitous molecule, secreted by hormone responsive organs and its synthesis is stimulated by androgens and progesterone but not oestrogens. In this article, a review of various literatures is done about the presence of extra prostatic PSA, its probable role in those sites as well as its utility as a tumour marker in breast cancer.

A case of metastatic cancer with markedly elevated PSA level that was not detected by repeat prostate biopsy

Background

Prostate-specific antigen (PSA) is a widely used specific tumor marker for prostate cancer. We experienced a case of metastatic prostate cancer that was difficult to detect by repeat prostate biopsy despite a markedly elevated serum PSA level.

Case presentation

A 64-year-old man was referred to our hospital with lumbar back pain and an elevated serum PSA level of 2036 ng/mL. Computed tomography, bone scintigraphy, and magnetic resonance imaging showed systemic lymph node and osteoblastic bone metastases. Digital rectal examination revealed a small, soft prostate without nodules. Ten-core transrectal prostate biopsy yielded negative results. Androgen deprivation therapy (ADT) was started because of the patient’s severe symptoms. Twelve-core repeat transrectal prostate biopsy performed 2 months later, and transurethral resection biopsy performed 5 months later, both yielded negative results. The patient refused further cancer screening because ADT effectively relieved his symptoms. His PSA level initially decreased to 4.8 ng/mL, but he developed castration-resistant prostate cancer 7 months after starting ADT. He died 21 months after the initial prostate biopsy from disseminated intravascular coagulation.

Conclusion

CUP remains a considerable challenge in clinical oncology. Biopsies of metastatic lesions and multimodal approaches were helpful in this case.

SRD5A2 gene polymorphisms affect the risk of breast cancer

Androgens in breast cancer have been studied alone and in correlation with estrogens as estrogen to testosterone ratio. 5-α-reductase is one of the important enzymes participating in androgen metabolism, which affects androgen activity by affecting conversion of testosterone to dihydrotestosterone. We hypothesized that polymorphisms in the SRD5A2 gene (encoding 5-α-reductase) may affect breast cancer risk by affecting total androgen activity. Complete coding region of the SRD5A2 gene was sequenced in a group of 628 patients and 244 control samples from three southern states (Tamil Nadu, Andhra Pradesh, and Karnataka) of India. We observed three common polymorphisms in this gene; namely, A49T, V89L, and (TA)n repeats. A49T locus was monomorphic in the study population, but V89L showed a strong correlation with breast cancer (P = 0.03, OR = 1.40, CI = 1.02-1.91). (TA)0/(TA)9 and (TA)9/(TA)9 genotypes were at a lower risk of breast cancer (P = 0.01, OR = 0.64, CI = 0.46-0.90). We conclude that SRD5A2 genotypes significantly affect breast cancer risk in the South Indian populations.

Breast and prostate cancer

There are interesting similarities between carcinomas of the breast and prostate. Both genetic and exogenous factors are probably important in the development of breast and prostate cancers. Since there is an alarming increasing trend in the incidence of both cancers worldwide including India, high level of apprehension/awareness has been created among the general educated population. Furthermore, both cancers are strongly linked with the expression of the c-erbB-2 oncogene which has been the focus of basic research in the recent past. This gene belongs to the family of growth factor receptors and it has important implication in diagnosis and future treatment modalities.

Changes in Serum PSA During Normal Menstrual Cycle

Prostate specific antigen (PSA) has long been used as a biological marker for prostatic cancer. Recent studies have demonstrated that PSA synthesis can be induced by steroid hormones in several tissues of women. Menstrual cycle is regulated by the cyclic variation of estradiol and progesterone. This study was undertaken in order to study the correlation of serum PSA to both these corpus luteal hormones. 110 serum samples and 10 saliva samples were collected from healthy women aged 18-45 years of age having normal menstrual cycles. Active PSA DSL-9700 ultrasensitive kit with detection limit 0.001 ng/ml was used to analyze PSA. 38.2 % of all serum samples and 10 % of saliva samples had detectable concentrations of PSA. The serum PSA was highest during mid follicular phase (between 4th and 8th days of cycle). Variation in PSA levels seemed to follow the variations in progesterone with a lag period of 12-14 days, but did not appear to bear any relationship with the estradiol levels.

The expression of prostate-specific antigen in invasive breast carcinoma and its relationship with routine clinicopathologic parameters

Background:

Invasive breast carcinoma is one of the most common cancers of women. Parameters such as lymph node status, tumor grade, and the status of hormone receptors are among the main prognostic determinants of this cancer. Immunohistochemical detection of prostate-specific antigen (PSA) is widely used to identify metastatic prostatic adenocarcinoma. However, its immunoreactivity has been found in some non-prostatic tissues. This study was conducted to assess PSA expression in invasive breast carcinoma and its relationship with routine clinicopathologic parameters.

Materials and Methods:

100 formalin-fixed and paraffin-embedded invasive breast carcinoma tissue specimens from the pathology archive of Alzahra hospital (Isfahan, Iran) were studied for the expression of estrogen receptor (ER), progesterone receptor (PR), HER2/neu, and PSA by immunohistochemistry. Stained sections were classified according to the intensity of staining and the percentage of cells showing PSA staining. The relationship between PSA expression and other markers, age, lymph node status, tumor subtype, and tumor grade was then studied.

Results:

No association was found between PSA expression on one hand and PR, Her2/neu, age, lymph node status, tumor grade, and tumor subtype on the other. PSA score was reversely correlated with ER expression (P = 0.015).

Conclusion:

Despite the reverse relationship between PSA expression and the immunoreactivity of ER, PSA expression was not correlated with other prognostic factors. Therefore, the detection of PSA by immunohistochemistry does not seem to be a significant prognostic parameter in patients with invasive breast carcinoma.

Prostate specific antigen in cord blood

Recent studies have demonstrated the presence of prostate specific antigen (PSA) in cord blood of male as well as female babies. The placental progesterone and estradiol up-regulate the synthesis and secretion of PSA in Placenta. This PSA is presumed to play a role in intrauterine growth of fetus by virtue of its proteolytic action on several substrates including insulin-like-growth-factor-binding-protein-3, insulin chains and Interleukin-2. This study was planned with the objective of correlating the levels of PSA in cord blood to gestation at delivery, the type of delivery and gender of the fetus. Fifty-seven cord blood samples were collected from the umbilical cord during delivery or mid-trimester abortion and analyzed for PSA using 'Active PSA DSL-9700 ultra sensitive' kit employing two-site immuno-radiometric assay principle and having a detection limit of 0.001 ng/ml. Mean PSA levels in cord blood were found to be 0.112 ± 0.027 ng/ml. The concentration of PSA in cord blood was found to be higher in case of higher gestational age, male baby and operative delivery. 50 % of cord bloods for female babies had PSA below detection limit (range <0.001-0.460 ng/ml), while all the male samples had detectable PSA (range 0.11-0.973 ng/ml). Higher Progesterone levels found in prenatal maternal blood in case of male babies may be responsible for the higher cord blood PSA. Mean cord blood PSA was 0.150 ± 0.150 ng/ml in forceps delivery and 0.078 ± 0.012 ng/ml in normal vaginal delivery. Forceps delivery causes much more stress and strain as compared to a normal vaginal delivery, resulting in increased levels of adrenal glucocorticoids, and therefore, higher cord blood PSA.

The physiology and pathobiology of human kallikrein-related peptidase 6 (KLK6)

The human kallikrein-related peptidase 6 (KLK6) gene belongs to the 15-member kallikrein (KLK) gene family mapping to chromosome 19q13.3-13.4. Encoding for an enzyme with trypsin-like properties, KLK6 can degrade components of the extracellular matrix. The successful utilisation of another KLK member (KLK3/PSA) for prostate cancer diagnosis has led many to evaluate KLK6 as a potential biomarker for other cancer and diseased states. The observed dysregulated expression in cancers, neurodegenerative diseases and skin conditions has led to the discovery that KLK6 participates in other cellular pathways including inflammation, receptor activation and regulation of apoptosis. Moreover, the improvements in high-throughput genomics have not only enabled the identification of sequence polymorphisms, but of transcript variants, whose functional significances have yet to be realised. This comprehensive review will summarise the current findings of KLK6 pathophysiology and discuss its potential as a viable biomarker.

Serum total PSA and free PSA in breast tumors

Now a days measurement of molecular forms of PSA has gained importance in clinical practice. Several studies have demonstrated the production of PSA in female tissues, such as breast. The present piece of work has been undertaken with an objective to estimate the relative proportion of the molecular forms of PSA in serum along with serum testosterone in benign and malignant breast tumor cases and to analyze their association with the severity of the disease process 34 malignant and 26 benign breast disease cases along with 33 healthy controls of same age group were enrolled in this study for evaluation. Serum testosterone was measured by ELISA, whereas serum total PSA (TPSA) and free PSA (FPSA) were estimated by electrochemiluminescence immunoassay. A significant rise of fasting plasma glucose along with prominent dyslipidemia was observed in breast tumor cases. Marked rise in serum testosterone as well as TPSA and FPSA was documented in both benign and malignant breast tumor cases. Serum testosterone revealed a significant positive association with both TPSA and FPSA pointing towards an etiological association between them. However, surgical removal of tumor mass resulted in a marked decline of presurgical value of both TPSA and FPSA with a non-significant fall in serum testosterone revealing tumor tissue as the source of FPSA and TPSA. Thus, estimation of PSA provides prognostic information that may assist in future treatment.

Prostate-specific antigen and hormone receptor expression in male and female breast carcinoma

Background

Prostate carcinoma is among the most common solid tumors to secondarily involve the male breast. Prostate specific antigen (PSA) and prostate-specific acid phosphatase (PSAP) are expressed in benign and malignant prostatic tissue, and immunohistochemical staining for these markers is often used to confirm the prostatic origin of metastatic carcinoma. PSA expression has been reported in male and female breast carcinoma and in gynecomastia, raising concerns about the utility of PSA for differentiating prostate carcinoma metastasis to the male breast from primary breast carcinoma. This study examined the frequency of PSA, PSAP, and hormone receptor expression in male breast carcinoma (MBC), female breast carcinoma (FBC), and gynecomastia.

Methods

Immunohistochemical staining for PSA, PSAP, AR, ER, and PR was performed on tissue microarrays representing six cases of gynecomastia, thirty MBC, and fifty-six FBC.

Results

PSA was positive in two of fifty-six FBC (3.7%), focally positive in one of thirty MBC (3.3%), and negative in the five examined cases of gynecomastia. PSAP expression was absent in MBC, FBC, and gynecomastia. Hormone receptor expression was similar in males and females (AR 74.1% in MBC vs. 67.9% in FBC, p = 0.62; ER 85.2% vs. 68.5%, p = 0.18; and PR 51.9% vs. 48.2%, p = 0.82).

Conclusions

PSA and PSAP are useful markers to distinguish primary breast carcinoma from prostate carcinoma metastatic to the male breast. Although PSA expression appeared to correlate with hormone receptor expression, the incidence of PSA expression in our population was too low to draw significant conclusions about an association between PSA expression and hormone receptor status in breast lesions.

Prostate specific antigen in women with menstrual disturbances and fibrocystic mastopathy

The objective of this study was to evaluate serum prostate specific antigen (PSA) levels in women with menstrual disturbances and fibrocystic mastopathy. A total of 114 women with fibrocystic breast disease with cysts <10 mm (group I), 62 with macrocysts >10 mm (group II) and 46 healthy volunteers, who served as control subjects, were recruited for this prospective study. Each patient underwent complete gynecological examination and had performed sonography of the breasts. Moreover menstrual pattern, serum levels of free and total PSA, LH, FSH, SHBG, PRL, estradiol, progesterone, TSH, T4, as well as serum total testosterone, were evaluated in each subject. We compared serum free and total PSA levels between women with different menstrual pattern within groups of women with micro- and macrocysts. We also evaluated correlations between serum free and total PSA and hormonal/descriptive variables. We found that, in group II, women with regular menses and polymenorrhea revealed significantly higher serum free PSA than women with oligomenorrhea and secondary amenorrhea. Moreover, we found a positive correlation between serum total testosterone and total PSA in the control group and between progesterone and total PSA in group II. Our data show that serum free PSA is increased in women with regular menstrual cycles and polymenorrhea. This later relationship refers to women with macrocysts. Further studies are required to clarify the relationships between serum PSA and menstrual disturbances in women with mastopathy.

Effect of Testosterone Administration on Serum and Urine Kallikrein Concentrations in Female-to-Male Transsexuals

Background: Concentrations of human tissue kallikreins (hKs), a group of 15 secreted serine proteases found in many tissues, are modulated by steroid hormones in cancer cell lines. To gain insight into in vivo kallikrein regulation we measured kallikrein concentrations in serum and urinary tissue in female-to-male transsexuals before and after testosterone administration.

Methods: We collected blood and urine samples before treatment and after 4 and 12 months from 28 female-to-male transsexuals who received 250 mg of testosterone esters intramuscularly every 2 weeks. We used ELISA assays to measure multiple kallikreins in serum and urine.

Results: After testosterone administration, serum testosterone concentrations increased by ∼15-fold. Serum kallikrein concentrations increased dramatically for hK3 (prostate-specific antigen) and increased moderately for hK2, hK5, hK6, hK7, hK8, hK10, and hK11. In urine, we noted major increases for hK3 and hK2 only. For all other kallikrein concentrations, we observed no considerable changes.

Conclusions: We conclude that, in serum and urine of female-to-male transsexuals after testosterone administration, hK3 (prostate-specific antigen) and to a lesser extent hK2 concentrations increase dramatically, but concentration of other kallikreins increase either moderately in serum (hK5, hK6, hK7, hK8, hK10, and hK11) or not at all in either serum (hK4, hK13, hK14) or urine (hK4, hK5, hK6, hK7, hK8, hK10, hK11, hK13, hK14).

Serum and Urine Tissue Kallikrein Concentrations in Male-to-Female Transsexuals Treated with Antiandrogens and Estrogens

Background: The expression of human tissue kallikrein genes is regulated by steroid hormones, but most studies have been conducted with cancer cell lines. Our purpose was to examine serum and urinary tissue kallikrein concentration changes in male-to-female transsexuals before and after treatment with antiandrogens and estrogens.

Methods: Thirty-five male-to-female transsexuals receiving cyproterone acetate and estrogens (orally or transdermally) were included in this study. Serum and urine samples were collected before initiation of therapy and 4 and 12 months post therapy. ELISAs were used to measure multiple kallikreins in serum and urine.

Results: After antiandrogen and estrogen therapy, serum testosterone concentrations decreased dramatically, as did serum and urinary concentrations of human glandular kallikrein (hK2) and prostate-specific antigen (PSA; hK3). Statistically significant but relatively small changes in serum and urinary concentrations of many other kallikreins were also seen. Kallikreins in serum and urine were correlated before and after treatment.

Conclusions: The concentrations of hK2 and hK3, but not of any other kallikreins, decrease dramatically after combined antiandrogen and estrogen treatment in male-to-female transsexuals. The smaller responses of the other kallikreins presumably reflect their expression in multiple tissues.

Serum PSA levels are not affected by the menstrual cycle or the menopause, but are increased in subjects with polycystic ovary syndrome

BACKGROUND/AIMS

Prostatic specific antigen (PSA) is the most specific prostatic tumor marker in man. Recently, PSA has been detected in a variety of tissues and fluids in women, and its determination suggested as a marker of hyperandrogenism. However, precise information about the physiology of PSA in females is not available. The goal of this study was to assess serum concentrations of PSA in healthy pre-menopausal women (healthy pre-menopausal group), menopausal women (menopause group) and patients with polycystic ovary syndrome (PCOS group).

METHODS

PSA, androgens, LH, FSH, 17-beta-estradiol (E2), progesterone (Pg) were assessed in 40 post-menopausal women, 35 fertile controls and 35 women with PCOS.

RESULTS

No significant difference in PSA concentrations could be demonstrated in different phases of the menstrual cycle in healthy pre-menopausal group and between pre- and post-menopausal groups. No correlations could be demonstrated between serum PSA levels and the following parameters: age, body mass index (BMI), LH, FSH, E2, testosterone (T), DHEAS, and SHBG, both in pre- and post-menopausal women. Significantly higher PSA levels (median=14 pg/ml) were found in the PCOS group compared to both pre-menopausal (median=5 pg/ml) and menopausal (median= 5 pg/ml) groups (p< 0.05).

CONCLUSIONS

only minor fluctuations of serum PSA concentrations are observed in healthy pre- and post-menopausal women, while serum level is higher in PCOS, and therefore PSA can be considered a suitable marker of female hyperandrogenism.

Human tissue kallikrein gene family: applications in cancer

Human tissue kallikrein genes, located on the long arm of chromosome 19, are a subgroup of the serine protease family of proteolytic enzymes. Initially thought to consist of three members, the human kallikrein locus has now been extended and includes 15 tandemly located genes. These genes, and their protein products, share a high degree of homology and are expressed in a wide array of tissues, mainly those that are under steroid hormone control. PSA (hK3) is one of the human kallikreins, and is the most useful tumor marker for prostate cancer screening, diagnosis, prognosis and monitoring. hK2, another prostate-specific kallikrein, has also been proposed as a complementary prostate cancer biomarker. In the past 5 years, the newly discovered kallikreins (KLK4-KLK15) have been associated with several types of cancer. For example, hK4, hK5, hK6, hK7, hK8, hK10, hK11, hK13 and hK14 are emerging biomarkers for ovarian, breast, prostate and testicular cancer. New evidence raises the possibility that some kallikreins are directly involved with cancer progression. We here review the evidence linking kallikreins and cancer and their applicability as novel biomarkers for cancer diagnosis and management.

Sensitivein vitro test systems to determine androgenic/antiandrogenic activity

We report on the establishment of one transgenic and two endogenous reporter gene assays to determine androgenic/antiandrogenic activity. A transient transactivation assay was developed in COS-7 African green monkey kidney cells. Three plasmids were co-transfected by electroporation: the human androgen receptor expression vector pSG5AR, the reporter gene vector pMamneoLuc, expressing luciferase under the control of the mouse mammary tumor virus (MMTV) promotor containing 4 hormone responsive elements (HREs), and the control plasmid pSVbeta. Transcriptional activation was measured by luciferase-mediated chemoluminescence. In T47D human breast cancer cells two endogenous reporter gene systems were established: one based on the androgen-induced expression of prostate-specific antigen (PSA), the other based on the androgen-repressed expression of testosterone repressed message 2 (TRPM-2). PSA protein was measured by enzyme-linked immunosorbent assay (ELISA), TRPM-2 m-RNA by reverse transcriptase polymerase chain reaction (RT-PCR). All three test systems were validated using the physiological androgen dihydrotestosterone (DHT) as agonist and the established antiandrogens hydroxyflutamide and p,p'-dichlorodiphenylethene (p,p'-DDE) as antagonists. The PSA assay was the most sensitive test system with an EC50 of 0.7 nM for DHT-induced response. The transient transactivation assay in COS-7 cells was less sensitive with an EC50 of 9.7 nM DHT. In the PSA assay hydroxyflutamide was a more potent antagonist (IC30 = 0.02 microM) than p,p'-DDE (IC30 = 0.9 microM). In the transient transactivation assay in COS-7 cells, both compounds elicited about 30% of the agonistic response induced by 100 nM DHT, thus showing partial agonistic properties. In summary, three highly sensitive and complementary in vitro test systems, together achieving enhanced specificity for detection and assessment of androgenic/antiandrogenic activity have been established and validated.

Androgen receptor in prostate cancer

The normal development and maintenance of the prostate is dependent on androgen acting through the androgen receptor (AR). AR remains important in the development and progression of prostate cancer. AR expression is maintained throughout prostate cancer progression, and the majority of androgen-independent or hormone refractory prostate cancers express AR. Mutation of AR, especially mutations that result in a relaxation of AR ligand specificity, may contribute to the progression of prostate cancer and the failure of endocrine therapy by allowing AR transcriptional activation in response to antiandrogens or other endogenous hormones. Similarly, alterations in the relative expression of AR coregulators have been found to occur with prostate cancer progression and may contribute to differences in AR ligand specificity or transcriptional activity. Prostate cancer progression is also associated with increased growth factor production and an altered response to growth factors by prostate cancer cells. The kinase signal transduction cascades initiated by mitogenic growth factors modulate the transcriptional activity of AR and the interaction between AR and AR coactivators. The inhibition of AR activity through mechanisms in addition to androgen ablation, such as modulation of signal transduction pathways, may delay prostate cancer progression.

Expression of androgen receptor and prostate-specific antigen in male breast carcinoma

BACKGROUND

The androgen-regulated proteins prostate-specific antigen (PSA) and prostate-specific acid phosphatase (PSAP) are present in high concentrations in normal prostate and prostatic cancer and are considered to be tissue-specific to prostate. These markers are commonly used to diagnose metastatic prostate carcinoma at various sites including the male breast. However, expression of these two proteins in tumors arising in tissues regulated by androgens such as male breast carcinoma has not been thoroughly evaluated.

METHODS

In this study we analyzed the expression of PSA, PSAP and androgen receptor (AR) by immunohistochemistry in 26 cases of male breast carcinomas and correlated these with the expression of other prognostic markers.

RESULTS

AR, PSA and PSAP expression was observed in 81%, 23% and 0% of carcinomas, respectively. Combined expression of AR and PSA was observed in only four tumors.

CONCLUSION

Although the biological significance of PSA expression in male breast carcinomas is not clear, caution should be exercised when it is used as a diagnostic marker of metastatic prostate carcinoma.

Secretion of endogenous kallikreins 2 and 3 by androgen receptor-transfected PC-3 prostate cancer cells

Androgen independent PC-3 cells lack androgen receptor (AR) expression and do not produce kallikrein 2 (hK2) or 3 (prostate-specific antigen, PSA). In this paper, we examined the ability of androgens to stimulate PSA and hK2 production in AR transfected PC-3 cells (PC-3(AR)) and compared this to LNCaP cells. PSA and hK2 were measured in the culture medium and cell lysates using an ELISA-based immunofluorometric assay. Only androgens were able to induce PSA and hK2 secretion in PC-3(AR) cells in a dose- and time-dependent manner depending on the level of AR present. The level of androgen-induced PSA and hK2 secretion in PC-3(AR) cells was approximately 1.5 and 0.9% that induced in LNCaP cells, respectively. Insulin-like growth factor-I (IGF-I), which has been shown to activate AR in the absence of ligand, did not activate PSA secretion in the absence of androgen, but further increased the dihydrotestosterone-induced PSA secretion in PC-3(AR) cells. The lack of PSA and hK2 production in parental PC-3 cells is thus a result of their lack of AR expression. PSA and/or hK2 production in PC-3(AR) cells can thus serve as an endogenous reporter system to investigate AR action or to screen putative endocrine disrupters.

The androgen-regulated gene human kallikrein 15 (KLK15) is an independent and favourable prognostic marker for breast cancer

Many kallikrein genes were found to be differentially expressed in various malignancies, and prostate specific antigen (encoded by the KLK3 gene) is the best tumour marker for prostate cancer. Prostate specific antigen has recently been shown to be an independent favourable prognostic marker for breast cancer. KLK15 is newly discovered kallikrein gene that is located adjacent to KLK3 on chromosome 19q13.4. KLK15 has 41% similarity to KLK3 and the encoded protein, hK15, can activate pro-prostate specific antigen. We studied the expression of KLK15 by real-time quantitative reverse transcriptase-polymerase chain reaction in 202 tissues from patients with breast carcinoma of various stages, grades and histological types. KLK15 expression was found to be a significant predictor of progression-free survival (hazard ratio of 0.41 and P=0.011) and overall survival (hazard ratio of 0.34 and P=0.009). When all other known confounders were controlled in the multivariate analysis, KLK15 retained its prognostic significance. Higher concentrations of KLK15 mRNA were found more frequently in node negative patients (P=0.042). No association was found between KLK15 expression and any other clinicopathological variable. Further, KLK15 is an independent prognostic factor of progression-free survival and overall survival in the subgroup of patients with lower grade and those with oestrogen receptor and progesterone receptor negative tumours in both univariate and multivariate analysis. KLK15 levels of expression were slightly higher (although not statistically significant) in the oestrogen receptor negative and progesterone receptor negative subgroups of patients. KLK15 is up-regulated by androgens in breast cancer cell lines. Time-course and blocking experiments suggest that this regulation is mediated through the androgen receptor.

Flavonoids can block PSA production by breast and prostate cancer cell lines

BACKGROUND

Prostatic carcinoma is the most commonly diagnosed cancer and the second leading cause of cancer death of North American men. Combined androgen blockade (CAB) is one treatment option for prostate cancer, using estrogen agonists, luteinizing hormone-releasing hormone (LHRH) agonists and non-steroidal anti-androgens such as nilutamide and cyproterone acetate. Since many of these drugs have serious side effects, many patients are searching for "natural" alternatives or complements to traditional therapy. These include phytoestrogens found in soy and other plant foods. Such compounds have only started to be evaluated for potential androgen-blocking activity. Inhibition of production of androgen-regulated proteins, including prostate-specific antigen (PSA), is one indicator of androgen blocking.

METHODS

The ability of 72 flavonoids and related compounds to inhibit PSA production in a breast cancer cell line, BT-474, and a prostate cancer cell line (PC-3), transfected with the human androgen receptor cDNA, PC-3(AR)(2) was examined.

RESULTS

Twenty-two of the 72 flavonoids tested were found to significantly block PSA production by the BT-474 cell line at the highest tested concentration (10(-5) mol/l), with 17 of these compounds inhibiting production of PSA in the PC-3(AR)(2) cells as well.

CONCLUSIONS

That several flavonoids may significantly block production of this androgen-regulated protein. It will be worthwhile to examine these compounds as possible candidates for prostate cancer prevention or management.

Circulating testosterone and prostate-specific antigen in nipple aspirate fluid and tissue are associated with breast cancer

Preliminary evidence has associated testosterone and prostate-specific antigen (PSA) with breast cancer. Our objective was to determine whether a) testosterone levels in nipple aspirate fluid (NAF), serum, or breast tissue are associated with breast cancer; b) testosterone levels in serum are associated with levels in NAF; c) PSA in NAF, serum, or breast tissue is associated with breast cancer; and d) serum PSA is associated with NAF PSA levels. We obtained 342 NAF specimens from 171 women by means of a modified breast pump. Additionally, we collected 201 blood samples from 99 women and 51 tissue samples from 41 subjects who underwent surgical resection for suspected disease. Women currently using birth control pills or hormone replacement therapy were excluded from the study. Controlling for age and menopausal status, serum testosterone was significantly increased in women with breast cancer (p = 0.002). NAF and serum testosterone levels were not associated. Neither NAF nor tissue testosterone was associated with breast cancer. Controlling for menopausal status and age, NAF PSA was significantly decreased in women with breast cancer (p < 0.001). We did not find serum PSA to be associated with breast cancer, although we found an indication that, in postmenopausal women, its levels were lower in women with cancer. Serum PSA was associated with NAF PSA in postmenopausal women (p < 0.001). PSA levels in cancerous tissue were significantly lower than in benign breast specimens from subjects without cancer (p = 0.011), whereas levels of PSA in histologically benign specimens from subjects with cancer were intermediate. Our results suggest that serum testosterone is increased and NAF PSA is decreased in women with breast cancer, with PSA expression being higher in normal than in cancerous breast tissues. NAF and serum PSA levels in postmenopausal women are correlated, suggesting that as laboratory assessment of PSA becomes more sensitive, serum PSA may become useful in identifying women with breast cancer.

Measurement of serum total and free prostate-specific antigen in women with colorectal carcinoma

We investigated the diagnostic value and the relationship with clinicopathological features of total and free prostate-specific antigen by measuring the concentrations of these markers in the sera of 75 women with colorectal carcinoma and in 30 healthy women. Measurements were performed by immunoradiometric assay which utilizes monoclonal and polyclonal anti-prostate-specific antigen antibodies; the lowest detection level for both markers was 0.01 ng ml(-1). Free prostate-specific antigen levels were significantly higher in women with colorectal carcinoma than healthy women (P=0.006). The percentage of free prostate-specific antigen predominant (free prostate-specific antigen/total prostate-specific antigen >50%) subjects was 20% in colorectal carcinoma patients and 3.3% in healthy women (P=0.035). Cut-off values were 0.34 ng ml(-1) for total prostate-specific antigen and 0.01 ng ml(-1) for free prostate-specific antigen. In women with colorectal carcinoma, total prostate-specific antigen positivity was 20% and free prostate-specific antigen positivity was 34.6%. When compared to negatives, total prostate-specific antigen positive patients had a lower percentage of well-differentiated (P=0.056) and early stage (stages I and II) tumours (P=0.070). However, patients with predominant free prostate-specific antigen, had a higher percentage of well-differentiated (P=0.014) and early stage tumours (P=0.090) than patients with predominant bound prostate-specific antigen. In conclusion, although the sensitivity of free prostate-specific antigen predominancy is low (20%), in distinguishing women with colorectal carcinoma than healthy women, its specificity is high (96.7%). Free prostate-specific antigen predominancy tends to be present in less aggressive tumours. These findings may indicate clinical significance of preoperative measurement of serum total and free prostate-specific antigen in women with colorectal carcinoma.

The role of molecular forms of prostate-specific antigen (PSA or hK3) and of human glandular kallikrein 2 (hK2) in the diagnosis and monitoring of prostate cancer and in extra-prostatic disease

Prostate-specific antigen (PSA or hK3) is a glandular kallikrein with abundant expression in the prostate that is widely used to detect and monitor prostate cancer (PCa), although the serum level is frequently elevated also in benign and inflammatory prostatic diseases. PSA testing is useful for early detection of localized PCa and for the detection of disease recurrence after treatment. However, PSA has failed to accurately estimate cancer volume and preoperative staging. There is no PSA level in serum that definitively distinguishes men with benign conditions from those with prostate cancer, although PCa is rare in men with PSA levels in serum < 2.0 ng/ml. This prompted searches for enhancing parameters to combine with PSA testing, such as PSA density, PSA velocity, and age-specific reference ranges. Due to the protease structure, PSA occurs in different molecular forms in serum and their concentrations vary according to the type of prostatic disease. Human glandular kallikrein 2 (hK2) is very similar to PSA, but expressed at higher levels in prostate adenocarcinoma than in normal prostate epithelium. Blood testing for hK2 combined with different PSA forms improves discrimination of men with benign prostatic disease from those with prostate cancer. Many data have also been reported on the extra-prostatic expression of both PSA and hK2, and it is now believed that they may both have functions in tissues outside the prostate.

Immunohistochemical analysis of prostate specific antigen in breast cancer

The presence of immunoreactive prostate-specific antigen (IR-PSA) has been reported in breast cancers and has been suggested to confer a positive prognosis. However, recent large, well-controlled studies have found no significant prognostic value when IR-PSA positivity is examined as an independent variable, even when ultrasensitive immunofluorometric techniques are utilized. The present study, using indirect immunohistochemistry on 75 formalin-fixed, paraffin-embedded breast cancers shows PSA immunoreactivity in only seven of 75 cases (9%), suggesting that PSA positivity in breast carcinoma is not useful as a prognostic or tumor marker with hospital-based methods.

Do wine polyphenols modulate p53 gene expression in human cancer cell lines?

BACKGROUND

The p53 gene is an established tumor suppressor and an inducer of apoptosis. We here attempt to determine whether the putative anticarcinogenic properties attributed to red wine and its polyphenolic constituents depend, at least in part, upon their ability to modulate p53 expression in cancer cells.

METHODS

Three human breast cancer cell lines (MCF-7, T47D; MDA-MB-486) and one human colon cancer cell line [Colo 320 HSR (+)] were treated for 24-h with each of four polyphenols [quercetin; (+)-catechin, trans-resveratrol; caffeic acid] at concentrations ranging from 10(-7) M to 10(-4) M, after which, p53 concentrations were measured in cell lysates by a time-resolved fluorescence immunoassay.

RESULTS

None of the polyphenols tested affected p53 expression in the breast cancer cell lines T-47D and MDA-MB-486. p53 content of MCF-7 breast cancer cells (wild-type) was increased by caffeic acid, decreased by resveratrol, and showed a twofold increase with catechin, that reached borderline statistical significance; however, none of these effects were dose-responsive. Colo 320 HSR (+) cells (with a mutant p53 gene) had lower p53 content upon stimulation, reaching borderline statistical significance, but without being dose-responsive, in the presence of caffeic acid and resveratrol. Apart from toxicity at 10(-4) M, quercetin had no effect upon these four cell lines.

CONCLUSIONS

The observed p53 concentration changes upon stimulation by polyphenols are relatively small, do not follow a uniform pattern in the four cell lines tested, and do not exhibit a dose-response effect. For these reasons, we speculate that the putative anticarcinogenic properties of wine polyphenols are unlikely to be mediated by modulation of p53 gene expression.

The new human tissue kallikrein gene family: structure, function, and association to disease

The human tissue kallikrein gene family was, until recently, thought to consist of only three genes. Two of these human kallikreins, prostate-specific antigen and human glandular kallikrein 2, are currently used as valuable biomarkers of prostatic carcinoma. More recently, new kallikrein-like genes have been discovered. It is now clear that the human tissue kallikrein gene family contains at least 15 genes. All genes share important similarities, including mapping at the same chromosomal locus (19q13.4), significant homology at both the nucleotide and protein level, and similar genomic organization. All genes encode for putative serine proteases and most of them are regulated by steroid hormones. Recent data suggest that at least a few of these kallikrein genes are connected to malignancy. In this review, we summarize the recently accumulated knowledge on the human tissue kallikrein gene family, including gene and protein structure, predicted enzymatic activities, tissue expression, hormonal regulation, and alternative splicing. We further describe the reported associations of the human kallikreins with various human diseases and identify future avenues for research.

Codon 89 polymorphism in the human 5 alpha-reductase gene in primary breast cancer

The enzyme human steroid 5-alpha reductase type II (SRD5A2) and androgen receptor (AR) are critical mediators of androgen action, suggesting a potential role in hormonally related cancers. The SRD5A2 gene harbours two frequent polymorphic sites, one in the coding region, at codon 89 of exon 1, where valine is substituted by leucine (V89L) and the other in the 3' untranslated region (3' UTR) where a variable number of dinucleotide TA repeat lengths exists. The V89L polymorphism is known to alter the activity of this enzyme. In the present study we examined 144 sporadic breast tumours from Italian patients for the V89L and TA polymorphisms by sequence and fragment analysis, respectively. Tumour extract prostate specific antigen (PSA) concentration as well as a number of well-established clinical and pathological parameters were evaluated. The results show that 53% of the tumours were homozygous for VV alleles, 37% were heterozygous for VL alleles and 10% were homozygous for LL alleles. TA(0) repeats were found in tumours with VV, LL and VL genotypes. TA(9) repeats were only found in VV homozygotes and were totally absent from either LL homozygotes or VL heterozygotes. PSA expression was significantly elevated in tumours with VV genotype. The presence of LL alleles in breast tumours is associated with earlier onset and shorter disease-free (RR = 2.65;P = 0.013) and overall survival (RR = 3.06;P = 0.014) rates. The VV genotype is associated with a more favourable prognosis. Our study suggests that the polymorphism in codon 89 of exon 1 of the human 5 alpha-reductase gene is related with TA repeat genotypes, PSA expression and breast cancer prognosis. More specifically, we found that the LL genotype is also associated with earlier onset and more aggressive forms of breast cancer. Long-term-outcome studies are needed to investigate the relevance of this polymorphism to breast cancer susceptibility.

Prostate-specific antigen (PSA/hK3): a further player in the field of breast cancer diagnostics?

Since its identification, much information has been obtained about prostate-specific antigen (PSA, or human glandular kallikrein 3 [hK3]), a kallikrein-like serine protease that is the most valuable tumour marker for the screening, diagnosis and management of human prostate carcinoma. Recently, it has become widely accepted that PSA is also present in many nonprostatic sources, casting doubts about the specificity of its tissue expression. Here we summarize the findings on the biomolecular expression of PSA in breast secretions, cells and tissues of healthy and diseased females. Although several studies have strongly suggested that the molecular forms of PSA seem to represent a potential tool for the risk assessment of breast cancer, recent reports have yielded conflicting results. Although several studies have suggested new biological function(s) for PSA in breast physiopathology, more studies are needed to enlist PSA unequivocally as an additional weapon in the anticancer armoury in breast cancer diagnostics.

Expression of prostate-specific antigen and human glandular kallikrein 2 in the thyroid gland

Prostate-specific antigen (PSA) and human glandular kallikrein 2 (hK2) are two closely related kallikreins, primarily produced by the prostate. These serine proteases are now used as biomarkers for the diagnosis and management of prostate cancer. Until recently, PSA and hK2 were thought to be strictly expressed in the prostate; however, numerous studies confirmed their presence in various biological fluids as well as in many normal and malignant tissues. Using reverse transcription-polymerase chain reaction (RT-PCR), we screened RNA extracted from 26 different normal tissues and found that both genes are expressed in the thyroid. Subsequently, we analyzed 15 RNAs extracted from thyroid tissues (10 benign and 5 malignant lesions) and found that both kallikreins were expressed in five specimens (four benign lesions and one malignant). Sequencing of the PCR products confirmed the specificity of our experiments. Immunohistochemistry localized PSA in oxyphilic cells of thyroid tissue. These data confirm expression of both PSA and hK2 in thyroid tissue and suggest that oxyphils are the source of their production. The function of these two proteases in thyroid tissue is unknown.