| 1. |
- Don-Doncow, Nicholas, et al.
(author)
-
Expression of STAT3 in Prostate Cancer Metastases
- 2017
-
In: European Urology. - : Elsevier BV. - 0302-2838. ; 71:3, s. 313-316
-
Journal article (peer-reviewed)abstract
- STAT3 and its upstream activator IL6R have been implicated in the progression of prostate cancer and are possible future therapeutic targets. We analyzed 223 metastatic samples from rapid autopsies of 71 patients who had died of castration-resistant prostate cancer (CRPC) to study protein and gene expression of pSTAT3 and IL6R. Immunohistochemical analysis revealed that 95% of metastases were positive for pSTAT3 and IL6R, with varying expression levels. Bone metastases showed significantly higher expression of both pSTAT3 and IL6R in comparison to lymph node and visceral metastases. STAT3 mRNA levels were significantly higher in bone than in lymph node and visceral metastases, whereas no significant difference in IL6R mRNA expression was observed. Our study strongly supports the suggested view of targeting STAT3 as a therapeutic option in patients with metastatic CRPC. Patient summary We studied the levels of two proteins (pSTAT3 and IL6R) in metastases from patients who died from castration-resistant prostate cancer. We found high levels of pSTAT3and IL6R in bone metastases, suggesting that these proteins could be used as targets for new anticancer drugs.
|
|
| 2. |
- Prencipe, Maria, et al.
(author)
-
Relationship Between Serum Response Factor and Androgen Receptor in Prostate Cancer
- 2015
-
In: The Prostate. - : Wiley. - 0270-4137. ; 75:15, s. 1704-1717
-
Journal article (peer-reviewed)abstract
- BACKGROUND. Serum response factor (SRF) is an important transcription factor in castrate-resistant prostate cancer (CRPC). Since CRPC is associated with androgen receptor (AR) hypersensitivity, we investigated the relationship between SRF and AR. MATERIALS AND METHODS. Transcriptional activity was assessed by luciferase assay. Cell proliferation was measured by MTT and flow cytometry. Protein expression in patients was assessed by immunohistochemistry. RESULTS. To investigate AR involvement in SRF response to androgen, AR expression was down-regulated using siRNA. This resulted in the abrogation of SRF induction post-DHT. Moreover, DHT stimulation failed to induce SRF transcriptional activity in AR-negative PC346 DCC cells, which was only restored following AR over-expression. Next, SRF expression was down-regulated by siRNA, resulting in AR increased transcriptional activity in castrate-resistant LNCaP Abl cells but not in the parental LNCaP. This negative feedback loop in the resistant cells was confirmed by immunohistochemistry which showed a negative correlation between AR and SRF expression in CRPC bone metastases and a positive correlation in androgen-naive prostatectomies. Cell proliferation was next assessed following SRF inhibition, demonstrating that SRF inhibition is more effective than AR inhibition in castrate-resistant cells. CONCLUSION. Our data support SRF as a promising therapeutic target in combination with current treatments. (C) 2015 Wiley Periodicals, Inc.
|
|
| 3. |
- Zivanovic, Andrej, et al.
(author)
-
Co-evolution of AR gene copy number and structural complexity in endocrine therapy resistant prostate cancer
- 2023
-
In: NAR Cancer. - : Oxford University Press. - 2632-8674. ; 5:3
-
Journal article (peer-reviewed)abstract
- Androgen receptor (AR) inhibition is standard of care for advanced prostate cancer (PC). However, efficacy is limited by progression to castration-resistant PC (CRPC), usually due to AR re-activation via mechanisms that include AR amplification and structural rearrangement. These two classes of AR alterations often co-occur in CRPC tumors, but it is unclear whether this reflects intercellular or intracellular heterogeneity of AR. Resolving this is important for developing new therapies and predictive biomarkers. Here, we analyzed 41 CRPC tumors and 6 patient-derived xenografts (PDXs) using linked-read DNA-sequencing, and identified 7 tumors that developed complex, multiply-rearranged AR gene structures in conjunction with very high AR copy number. Analysis of PDX models by optical genome mapping and fluorescence in situ hybridization showed that AR residing on extrachromosomal DNA (ecDNA) was an underlying mechanism, and was associated with elevated levels and diversity of AR expression. This study identifies co-evolution of AR gene copy number and structural complexity via ecDNA as a mechanism associated with endocrine therapy resistance.
|
|
