Knockdown of PSCA induces EMT and decreases metastatic potentials of the human prostate cancer DU145 cells

A glycolysis-related signature to improve the current treatment and prognostic evaluation for breast cancer

Background

As a heterogeneous malignancy, breast cancer (BRCA) shows high incidence and mortality. Discovering novel molecular markers and developing reliable prognostic models may improve the survival of BCRA.

Methods

The RNA-seq data of BRCA patients were collected from the training set The Cancer Genome Atlas (TCGA)-BRCA and validation set GSE20685 in the Gene Expression Omnibus (GEO) databases. The "GSVA" R package was used to calculate the glycolysis score for each patient, based on which all the patients were divided into different glycolysis groups. The "limma" package was employed to perform differentially expression genes (DEGs) analysis. Key signature genes were selected by performing un/multivariate and least absolute shrinkage and selection operator (LASSO) C regression and used to develop a RiskScore model. The ESTIMATE and MCP-Counter algorithms were used for quantifying immune infiltration level. The functions of the genes were validated using Western blot, colony formation, transwell and wound-healing assay.

Results

The glycolysis score and prognostic analysis showed that high glycolysis score was related to tumorigenesis pathway and a poor prognosis in BRCA as overactive glycolysis inhibited the normal functions of immune cells. Subsequently, we screened five key prognostic genes using the LASSO Cox regression analysis and used them to establish a RiskScore with a high classification efficiency. Based on the results of the RiskScore, it was found that patients in the high-risk group had significantly unfavorable immune infiltration and prognostic outcomes. A nomogram integrating the RiskScore could well predict the prognosis for BRCA patients. Knockdown of PSCA suppressed cell proliferation, invasion and migration of BRCA cells.

Conclusion

This study developed a glycolysis-related signature with five genes to distinguish between high-risk and low-risk BRCA patients. A nomogram developed on the basis of the RiskScore was reliable to predict BRCA survival. Our model provided clinical guidance for the treatment of BRCA patients.

Silencing effects of FOXD1 inhibit metastatic potentials of the PCa via N-cadherin - Wnt/β-catenin crosstalk

The elucidation of the mechanisms controlling the metastatic processes is important for the development of new treatment methods to prevent the progression of localized disease to metastasis. Forkhead box D1 (FOXD1) is a member of the FOX transcription factor family and has been reported to play an important role in the development and progression of various cancers. However, its role in prostate cancer (PCa) remains only partially understood. Therefore, we aimed to explore the effects on the associated regulatory signal pathway of FOXD1 in prostate cancer. To clarify the roles of FOXD1 in prostate cancer, we used siRNA to suppress its expression in 22Rv1 cells with relatively higher expression of FOXD1. The effects of FOXD1 silencing on cell proliferation, migration and invasion were determined. WST-1 assays were used to determine cell proliferation. Cell migration and invasion were evaluated through wound healing and transwell assays. The possible underlying mechanism of FOXD1 silencing on 22Rv1 was evaluated by determining the expression of proteins related to EMT and Wnt/β-catenin signaling pathway. Our results showed that FOXD1 was highly expressed in prostate cancer cell lines -PC-3, DU145, LNCaP and 22Rv1- compared to normal prostate epithelial cell line RWPE-1. Additionally, silencing of FOXD1 significantly reduced proliferation, migration and invasion of 22Rv1 cells. Furthermore, silencing of FOXD1 decreased the expression of β-catenin and cyclin D1, which are involved in the Wnt/β-catenin signaling pathway. However, it did not appear to affect the expression of EMT-related proteins other than N-cadherin. Our results suggest that silencing of FOXD1 suppresses metastatic potentials of the PCa via N-cadherin - Wnt/β-catenin crosstalk. Therefore, the expression status of FOXD1 may be a new prognostic factor as well as a potential therapeutic target in prostate cancer treatment.

Novel Redirected T-Cell Immunotherapies for Advanced Prostate Cancer

Immunotherapy has failed to achieve durable remissions in advanced prostate cancer patients. More potent T-cell-redirecting strategies may be needed to overcome the immunologically exclusive and suppressive tumor microenvironment. Clinical trials are underway, seeking to define the optimal target for T-cell redirection, such as PSMA, PSCA, or STEAP-1, as well as the optimal strategy, with CAR or bispecific antibodies. As results continue to emerge from these trials, understanding differential toxicity and efficacy of these therapies based on their targets and functional modifications will be key to advancing these promising therapies toward clinical practice. This review provides a unique depth and breadth of perspective regarding the diverse immunotherapy strategies currently under clinical investigation for men with advanced prostate cancer.

lncRNA SNHG11 facilitates prostate cancer progression through the upregulation of IGF‑1R expression and by sponging miR‑184

Long non‑coding RNA (lncRNA) small nucleolar RNA host gene 11 (SNHG11) has been shown to play an important role in the development and progression of numerous types of cancer. However, to the best of our knowledge, the role of SNHG11 in prostate cancer (PCa) development and metastasis remains unclear. Thus, the aim of the present study was to investigate the functional role and molecular mechanisms of SNHG11 in PCa progression. It was revealed that the SNHG11 expression levels were significantly upregulated in PCa tissues, in comparison with those in adjacent normal tissues. Functionally, SNHG11 knockdown significantly suppressed PCa cell proliferation, migration, invasion and metastasis in vitro and in vivo. Furthermore, SNHG11 was found to positively regulate insulin‑like growth factor 1 receptor (IGF‑1R) expression by sponging microRNA (miRNA/miR)‑184 in PCa cells. The results of rescue experiments demonstrated that IGF‑1R overexpression reversed the suppressive effects of SNHG11 knockdown on the proliferation, migration and invasion of PCa cells. On the whole, the findings of the present study suggest that SNHG11 expression is upregulated in PCa and that it facilitates PCa progression, at least in part, via the modulation of the miR‑184/IGF‑1R signaling axis.

miR-199b-5p-DDR1-ERK signalling axis suppresses prostate cancer metastasis via inhibiting epithelial-mesenchymal transition

Background

The investigation of underlying mechanism and the exploitation of novel therapies for metastatic prostate cancer (PCa) are still urgently needed. miR-199b-5p has been suggested to function as tumour suppressor in various human cancers. However, the clinical significance and role of miR-199b-5p in PCa remain unclear.

Methods

The current study sought to investigate the expression status of miR-199b-5p in PCa and the involved molecular mechanisms in PCa metastasis by using bioinformatics analyses, loss-and gain-of-functions and rescue experiments in vitro and in vivo.

Results

We demonstrated that miR-199b-5p was significantly downregulated in metastatic PCa tissues and cells when compared with the normal prostate tissue, the localised disease, the weakly metastatic and androgen-dependent PCa cell and the normal prostate epithelial cell. We also found that miR-199b-5p drastically suppressed PCa cell proliferation, migration and invasion in vitro and inhibited xenografts tumour growth and metastasis in vivo. Mechanistically, our results showed that miR-199b-5p could inhibit discoidin domain receptor tyrosine kinase 1 (DDR1) expression by directly targeting its 3’-UTR, thereby hindering epithelial-mesenchymal transition (EMT)-associated traits, which were induced by DDR1 activating ERK signalling pathway. Moreover, PCa patients with low miR-199b-5p expression level had a remarkably shorter overall survival than those with high miR-199b-5p level, indicating an association of miR-199b-5p loss with poor prognosis in patients with PCa. Furthermore, DDR1 was upregulated in PCa, and significantly correlated with high Gleason score, advanced pathological stage, tumour metastasis and shorter overall survival.

Conclusions

Our study, for the first time, provide evidence of a tumour-suppressive function of miR-199b-5p in the invasion and metastasis of PCa, supporting the translational exploitation of miR-199b-5p-based therapeutic approaches for PCa metastases. Also, the miR-199b-5p-DDR1-ERK signalling axis identified in this study represents a novel mechanism of regulating EMT in PCa metastases.

The Correlation between PSCA Expression and Neuroendocrine Differentiation in Prostate Cancer

The prostate stem cell antigen (PSCA), as a predominantly prostate-specific marker, is overexpressed in most prostate cancer specimens, is positively correlated with prostate cancer androgen independence, and has the potential to be treated with castration-resistant prostate cancer (CRPC) as a gene therapy target. Using the typical androgen deprivation therapy, most tumors will progress to CRPC, as well as develop into neuroendocrine prostate cancer (NEPC) characterized by the expression of neuroendocrine markers such as enolase 2 (NSE). Our study was aimed at investigating the expressions of PSCA and NSE and the relationship between the two markers, as well as the correlation between the PSCA and NSE expressions and the clinicopathological parameters in prostate cancer specimens from 118 patients by using immunohistochemistry. Our results demonstrated that the PSCA and NSE protein expressions did not correlate with the prostate cancer patients' age or the hormone therapy but showed a significant correlation with the pathological tumor stage of prostate cancer, the Gleason score, and the presence of metastasis. There is a positive association between PSCA and NSE but a negative one between the prostate-specific antigen (PSA) and PSCA or between PSA and NSE. High PSCA and NSE expressions correlated with a poor prognosis in prostate cancer patients. PSCA may play an important role in the progression of neuroendocrine prostate cancer (NEPC).

Identifying the key genes and microRNAs in prostate cancer bone metastasis by bioinformatics analysis

Prostate adenocarcinoma (PCa) is the most common cause of death due to malignancy among men, and bone metastasis is the leading cause of mortality in patients with PCa. Therefore, identifying the causes and molecular mechanism of bone metastasis is important for early detection, diagnosis and personalized therapy. In this study, we systematically analyzed molecular correlates of bone metastasis by bioinformatics analysis. A total of 12 differentially expressed microRNAs (miRNAs) and 102 differentially expressed genes were identified. Five miRNAs had prognostic significance in biochemical recurrence‐free survival (miR‐636, miR‐491‐5p, miR‐199b‐5p, miR‐199b‐3p, miR‐28‐3p). The differentially expressed genes were significantly enriched in extracellular matrix, cell‐substrate adhesion, collagen and integrin. Seven hub genes (VCAN, COL3A1, COL1A1, APOE, COL1A2, SDC1, THY1) with worse biochemical recurrence‐free survival and one hub gene (MMP9) with worse overall survival were detected. miR‐636, a novel oncogene, was found to be up‐regulated in bone metastatic PCa tissues and also predominately up‐regulated in human PCa cell lines. miR‐636 promoted cellular invasion and migration, and may promote bone metastasis via targeting MBNL2, TNS1 and STAB1. In conclusion, we have successfully defined molecular signatures of bone metastasis in PCa.

Long Noncoding RNA ZFAS1 Promotes Progression of NSCLC via Regulating of miR-590-3p

The incidence and mortality rate of nonsmall cell lung cancer (NSCLC) are continuously increasing. Recently, the important roles of long noncoding ribonucleic acid (lncRNA) zinc finger antisense1 (ZFAS1) in the development of many disease have been proved. However, the roles of ZFAS1 in NSCLC are still not completely understood. Thus, this study aimed to explore the potential roles and underlying mechanisms of lncRNA ZFAS1 in the progression of NSCLC. Our results demonstrated that lncRNA ZFAS1 expression was significantly upregulated in NSCLC tissues and cell lines. Loss-of-function experiments revealed that lncRNA ZFAS1 inhibition could remarkably suppress NSCLC cells proliferation in vitro. Bioinformatic analysis and luciferase reporter assay revealed that lncRNA ZFAS1 directly interacted with miR-590-3p. Rescue experiments showed that miR-590-3p inhibitor reversed the cell proliferation function of lncRNA ZFAS1 knockdown in vitro. Furthermore, we confirmed that lncRNA ZFAS1 inhibited cell division cycle 42 (Cdc42) expression by regulating of miR-590-3p in NSCLC cells. Therefore, our study indicates that lncRNA ZFAS1/miR-590-3p axis is involved in NSCLC cell proliferation. It also suggests that lncRNA ZFAS1 is a putative tumor oncogene in NSCLC.

miR-141-3p and TRAF5 Network Contributes to the Progression of T-Cell Acute Lymphoblastic Leukemia

Numerous lines of evidence have shown that microRNAs (miRNAs) play a vital role in regulating the progression in many types of cancers, including T cell acute lymphoblastic leukemia (T-ALL). In this study, the potential underlying mechanism and functional role of miR-141-3p in T-ALL cells were determined. We found that the expression level of miR-141-3p was significantly downregulated, while that of tumor necrosis factor receptor-associated factor 5 (TRAF5) was strongly upregulated in tissues from patients with T-ALL compared with healthy controls. Subsequently, upregulation of miR-141-3p significantly repressed T-ALL cell proliferation and promoted cell apoptosis. Conversely, downregulation of miR-141-3p significantly inhibited cell apoptosis and enhanced T-ALL cell proliferation. We also verified that TRAF5 was the direct target of miR-141-3p in T-ALL cells. Additionally, TRAF5 overexpression significantly repressed cell apoptosis and increased T-ALL cell proliferation. In summary, miR-141-3p regulates T-ALL cell progression by directly targeting TRAF5, and may serve as a potential therapeutic target for T-ALL.

Shengjing Capsule Improves Spermatogenesis through Upregulating Integrin α6/β1 in the NOA Rats

Objective

To evaluate the therapeutic effect of Shengjing capsules on nonobstructive azoospermia (NOA) in the rat model.

Methods

Twenty-five male Sprague–Dawley rats were randomly divided into five groups as follows (n=5 per group): normal group, NOA group, and three Shengjing capsule treatment groups (low-dose, medium-dose, and high-dose groups, respectively). HE staining and semen smear were performed to assess sperm quality. The expression levels of PI3K/AKT and integrin α6/β1 were measured by qRT-PCR and western blot analyses.

Results

In the NOA group, almost all of the seminiferous tubules were vacuolated with a thin layer of basal compartment containing some spermatogonial stem cells. The counts of sperms in the NOA group were strongly lower than those of the normal group (P=0.0001). The expression of PI3K/AKT and integrin α6/β1 was scarcely expressed in the NOA group. All indexes mentioned above were significantly different from those of the medium- and high-dose groups (P=0.001, all). The sperm count of rats treated with Shengjing capsules was significantly higher than that of the NOA group (P=0.0001). The rats of Shengjing capsule groups had more layers of spermatogonial stem cells and spermatocytes, and some had intracavitary sperms.

Conclusions

Shengjing capsules may be a promising therapeutic medicine for NOA. The underlying mechanisms might involve activating SSCs by upregulating the integrin α6/β1 expression via the PI3K/AKT pathway.

Gasoline exhaust damages spermatogenesis through downregulating α6-integrin and β1-integrin in the rat model

The health influence of air pollution has been an international public health concern. Increasing evidence has suggested that air pollution has been associated with decreased sperm quality. However, the underlying molecular mechanisms are still not fully elucidated. We aimed to verify whether gasoline exhaust leads to reproductive impairment by injuring spermatogonial stem cells and explore its underlying molecular mechanism. Twenty male Sprague-Dawley rats were randomly divided into two groups: the exposure group (n = 10) and the control group (n = 10). After 6-month exposure, the sperm count and morphology were determined. The histological changes in the seminiferous tubules were examined by HE staining. The expression of α6-integrin and β1-integrin was assessed with Quantitative RT-PCR, Western blot and Immunohistochemical staining. Compared with control group, male rats exposed to gasoline exhaust showed significantly reduced sperm count, increased sperm abnormality rate and the total number of spermatogonia, primary spermatocytes, secondary spermatocytes, spermatids were decreased. (all p < .01). The expression levels of α6-integrin and β1-integrin in the exposure group were significantly lower than those in the control group (all p < .01). Our study showed that exposure to gasoline exhaust caused impairment to spermatogonial stem cells through downregulating α6-integrin and β1-integrin.

PSCA promotes prostate cancer proliferation and cell-cycle progression by up-regulating c-Myc

BACKGROUND

The Prostate stem cell antigen (PSCA) is a glycosylphosphatidylinositol (GPI)-anchored protein. Increasing evidence has indicated PSCA plays an important role in tumorigenesis. However, its function and the underlying molecular mechanisms in prostate cancer (PCa) are still not fully elucidated. In this study, we aimed to explore the effect of PSCA on cell cycle of PCa cells and its mechanism research.

METHODS

Immunohistochemistry, quantitative reverse transcription-PCR (qRT-PCR) and Western blotting were used to quantify PSCA expression pattern in PCa tissues and cell lines. The association of PSCA expression with the biochemical recurrence (BCR)-free survival and overall survival (OS) of PCa patients were analyzed using Kaplan-Meier method. The roles of PSCA in PCa were confirmed based on both in vitro and in vivo systems.

RESULTS

Immunohistochemistry results showed that PSCA was upregulated in PCa tissue. PSCA overexpression were significantly associated with high Gleason score (GS) (P = 0.028), positive BCR (P = 0.002), and poor OS (P = 0.032) and high c-Myc expression (P = 0.019). PSCA promoted PCa cell cycle progression and tumor growth via increased c-Myc expression. Additional, PI3K/AKT signaling pathways was involved in PSCA-mediated c-Myc expression and cell proliferation.

CONCLUSIONS

PSCA is a novel cell cycle regulator with a key role in mediating c-Myc-induced proliferation. PSCA may be a potential diagnostic marker and therapeutic target for patients with PCa.

PSCA regulates IL-6 expression through p38/NF-κB signaling in prostate cancer

BACKGROUND

Prostate stem cell antigen (PSCA) is a glycosylphosphatidylinositol (GPI)-anchored cell surface protein. We previously reported that PSCA involved in proliferation and invasion of PCa cells, however, the underlying mechanisms are unknown. In this study, we aimed to explore the regulating role of PSCA gene expression in interleukin-6 (IL-6) autocrine of PCa cells.

METHODS

The stable knockdown-PSCA and ectopically overexpressed-PSCA vector were constructed and transfected into human PCa DU145 and PC-3M cells. The effects of PSCA overexpression or knockdown were determined in proliferation, invasion, and metastasis assays. The effect of PSCA on the expression and secretion of IL-6 was evaluated by immunoblotting and ELISA. Subcellular localization and expression pattern of PSCA and IL-6 protein were examined by immunohistochemistry. Its clinical significance was statistically analyzed.

RESULTS

The results showed that stable knockdown of PSCA delayed proliferation, migration, and invasion while overexpressing PSCA enhanced the proliferation, migration, and invasion in vitro and the lung metastasis in vivo of PCa cells. Importantly, the PSCA involved in the IL-6 secretion and positively regulated p38/NF-κB/IL-6 signaling, leading to enhanced PCa cell invasion and metastasis. Both the expression of PSCA and IL-6 were significantly associated with poor biochemical recurrence-free survival of patients with PCa. PSCA protein expression showed a prognostic value in overall survival as indicated by Kaplan-Meier analysis.

CONCLUSIONS

These results indicate that PSCA regulates the expression and secretion of IL-6 in human PCa cells through p38/NF-κB signaling pathways. PSCA may be a potential diagnostic marker and therapeutic target for PSCA-positive PCa.

Prostate cancer immunotherapy, particularly in combination with androgen deprivation or radiation treatment. Customized pharmacogenomic approaches to overcome immunotherapy cancer resistance

Conventional therapeutic approaches for advanced prostate cancer - such as androgen deprivation, chemotherapy, radiation - come up often against lack of effectiveness because of possible arising of correlative cancer cell resistance and/or inadequate anti-tumor immune conditions. Whence the timeliness of resorting to immune-based treatment strategies including either therapeutic vaccination-based active immunotherapy or anti-tumor monoclonal antibody-mediated passive immunotherapy. Particularly attractive, as for research studies and clinical applications, results to be the cytotoxic T-lymphocyte check point blockade by the use of anti-CTLA-4 and PD-1 monoclonal antibodies, particularly when combined with androgen deprivation therapy or radiation. Unlike afore said immune check point inhibitors, both cell-based (by the use of prostate specific antigen carriers autologous dendritic cells or even whole cancer cells) and recombinant viral vector vaccines are able to induce immune-mediated focused killing of specific antigen-presenting prostate cancer cells. Such vaccines, either used alone or concurrently/sequentially combined with above-mentioned conventional therapies, led to generally reach, in the field of various clinical trials, reasonable results particularly as regards the patient's overall survival. Adoptive trasferred T-cells, as adoptive T-cell passive immunotherapy, and monoclonal antibodies against specific antigen-endowed prostate cancer cells can improve immune micro-environmental conditions. On the basis of a preliminary survey about various immunotherapy strategies, are here also outlined their effects when combined with androgen deprivation therapy or radiation. What's more, as regard the immune-based treatment effectiveness, it has to be pointed out that suitable personalized epigenetic/gene profile-achieved pharmacogenomic approaches to target identified gene aberrations, may lead to overcome - as well as for conventional therapies - possible prostate cancer resistance to immunotherapy.

Do the expressions of epithelial-mesenchymal transition proteins, periostin, integrin-α4 and fibronectin correlate with clinico-pathological features and prognosis of metastatic castration-resistant prostate cancer?

Development of metastatic castration-resistant prostate cancer is a result of the lack of an apoptotic response by the tumor cells and loss of the ability to stick to adjacent cells through epithelial-mesenchymal transition. Although there are several strongly recommended biomarkers for determining prognosis of metastatic castration-resistant prostate cancer, only few of them may help decide the selection of the optimal treatment option. The mode of treatment sequencing in metastatic castration-resistant prostate cancer will be based on the individual characteristics of the patient. In this study, we aimed to explain the correlation between the expression characteristics of periostin, integrin-α4, and fibronectin in metastatic castration-resistant prostate cancer patients and their clinico-pathological data comprising Gleason score, PSA levels, and metastatic sites in the process of epithelial-mesenchymal transition. We evaluated by using Western blotting, periostin, integrin-α4, and fibronectin expressions in peripheral blood samples of metastatic castration-resistant prostate cancer patients ( n = 40), benign prostatic hyperplasia patients ( n = 20), and the healthy control group ( n = 20). Associations between changes in the protein expressions and clinico-pathological parameters were also analyzed in the metastatic castration-resistant prostate cancer group. When comparing BPH and healthy groups with the metastatic castration-resistant prostate cancer group, a reduced expression of integrin-α4 was found in metastatic patients, albeit being statistically insignificant ( P > 0.05). Protein expressions of periostin and fibronectin in the metastatic castration-resistant prostate cancer group were higher than those in the BPH and heathy groups ( P < 0.001). Increased periostin expression in metastatic patients was significantly associated with bone metastasis ( P < 0.05). Elevated periostin and fibronectin levels in metastatic castration-resistant prostate cancer patients may be appropriate targets of therapeutic intervention in the future. Impact statement Prostate cancer is the third most common cancer in the world and the most common cancer among men. Development of metastatic castration-resistant prostate cancer (mCRPC) is a result of the lack of an apoptotic response by the tumor cells and loss of the ability to stick to adjacent cells through epithelial-mesenchymal transition (EMT). The present study analyzes for the first time the expressions of EMT marker proteins - periostin, integrin α4, fibronectin - in mCRPC and in benign prostatic hyperplasia (BPH) with the aim to determine the clinical relevance of changes in these three proteins vis-a-vis the PCa aggressive phenotype. In doing so, it sheds light on the molecular mechanism underlying the disease. We concluded that elevated periostin and fibronectin levels in mCRPC patients may be appropriate targets of therapeutic intervention in the future; hence, adopting methods that target these proteins may help treat prostate cancer effectively.

Amplification and overexpression of PSCA at 8q24 in invasive micropapillary carcinoma of breast

PURPOSE

Invasive micropapillary carcinoma (IMPC) of the breast has distinct histological features and molecular genetic profiles. Gains/amplifications of 8q24 are found associated with IMPC. Although the prostate stem cell antigen (PSCA) gene is located at chromosome 8q24, and found over-expressed in prior studies, its prognostic values and biological significance in IMPC have not been well studied.

METHODS

Fluorescence in situ hybridization (FISH) was used to assess the frequencies of PSCA copy number gains in IMPC, invasive ductal carcinoma of no special type (IDC-NST), and invasive lobular carcinoma (ILC) samples. The protein expression levels of PSCA were examined in 56 IMPC, 72 IDC-NST, and 56 ILC samples using immunohistochemical analysis.

RESULTS

PSCA gene amplification was detected in 45.2% (14/31) of the IMPC, 28.1% (9/32) of the IDC-NST, and none (0/25) of the ILC. PSCA protein expression was observed in 58.9% (33/56), 40.3% (29/72), and 3.6% (2/56) of IMPC, IDC-NST, and ILC samples, respectively. The concordant rate of the immunohistochemistry and FISH data was 85.2%. PSCA gene amplification highly correlated with its protein overexpression (rs = 0.687, P < 0.001), suggesting that gene amplification is an important mechanism involved in PSCA overexpression. Our univariate analysis showed that the patients with PSCA-positive IMPC had a decreased disease-free survival (DFS) compared to PSCA-negative IMPC patients (P = 0.003). Our multivariate analysis confirmed the worse DFS in PSCA-positive IMPC patients (P = 0.022).

CONCLUSIONS

Our results indicate that PSCA may be an attractive target in the 8q24 amplicon and that it may serve as a molecular marker of metastasis and recurrence in IMPC. The differential expression of PSCA may be associated with cell adhesion. Detection of PSCA protein and gene amplification may help manage and predict the prognosis of IMPC patients.

Expression of prostate stem cell antigen is downregulated during flavonoid-induced cytotoxicity in prostate cancer cells

Prostate stem cell antigen (PSCA) is expressed in the majority of prostate cancer cases and may be a potential therapeutic target in the treatment of prostate cancer. The present study evaluated the cytotoxicity of three flavonoids (genistein, luteolin and quercetin) towards DU145 prostate cancer cells, and investigated the effect of these flavonoids on PSCA expression. The results demonstrated that genistein, luteolin and quercetin inhibited the growth of DU145 cells in a dose-dependent manner (P<0.05) and induced morphological changes characteristic of apoptosis in DU145 cells. Flow cytometry analysis also indicated that the flavonoids induced S phase cycle arrest in DU145 cells. Notably, it was observed that expression of PSCA was inhibited at the mRNA (P<0.05) and protein levels in DU145 cells following flavonoid treatment compared with the control. These results suggest that flavonoids may be potential therapeutic agents in the treatment and prevention of prostate cancer.

Exploratory investigation of PSCA-protein expression in primary breast cancer patients reveals a link to HER2/neu overexpression

BACKGROUND

Prostate stem cell antigen (PSCA) has been suggested as biomarker and therapeutic target for prostate cancer. Recent advances showed that PSCA is up-regulated in other cancer entities, such as bladder or pancreatic cancer. However, the clinical relevance of PSCA-expression in breast cancer patients has not yet been established and is therefore addressed by the current study.

METHODS

PSCA-protein expression was assessed in 405 breast cancer patients, using immunohistochemistry (PSCA antibody MB1) and tissue microarrays.

RESULTS

PSCA-expression was detected in 94/405 patients (23%) and correlated with unfavorable histopathological grade (p=0.011) and increased Ki67 proliferation index (p=0.006). We observed a strong positive correlation between PSCA-protein expression and HER2/neu receptor status (p<0.001). PSCA did not provide prognostic information in the analyzed cohort. Interestingly, the distribution of PSCA-expression among triple negative patients was comparable to the total population.

CONCLUSION

We identified a subgroup of PSCA-positive breast cancer patients, which could be amenable for a PSCA-targeted therapy. Moreover, given that we found a strong positive correlation between PSCA- and HER/neu expression, targeting PSCA may provide an alternative therapeutic option in case of trastuzumab resistance.