Differences in genomic signatures and opportunities for targeted and immunotherapy treatment between castrate-resistant TMPRSS2:ERG fusion-positive and -negative refractory acinar (CRPC) and neuroendocrine prostate cancer (CRNEPC).

2018 ◽  
Vol 36 (15_suppl) ◽  
pp. 5061-5061
Author(s):  
Leszek Kotula ◽  
Gennady Bratslavsky ◽  
Hugh A.G. Fisher ◽  
Timothy Byler ◽  
Robert John Corona ◽  
...  
2018 ◽  
Vol 36 (6_suppl) ◽  
pp. 348-348 ◽  
Author(s):  
Gennady Bratslavsky ◽  
Hugh A.G. Fisher ◽  
Timothy Byler ◽  
Joseph M Jacob ◽  
Jon Chung ◽  
...  

348 Background: We performed comprehensive genomic profiling (CGP) to learn whether sub-categorization of TMPRSS2 fusion status would impact therapy opportunities in patients with refractory CRPC and CRNEPC. Methods: DNA was extracted from 40 µm of FFPE sections of 2,424CRPC and 143 CRNEPC. CGP was performed on hybridization-captured, adaptor ligation-based libraries for up to 315 cancer-related genes. Tumor mutational burden (TMB) was determined on 1.1 Mbp of sequenced DNA and microsatellite instability (MSI) was determined on 114 loci. Results: The median ages for all 4 groups was similar (Table). TMPRSS2+( TMP+) CRPC features significantly greater TP53 and PTEN GA and TMPRSS2-( TMP-) CRPC featured higher MYC and ATM GA. Differences in BRCA2 and RB1 GA were not significant in the CRPC group. RB1 GA were more frequent in CRNEPC than CRPC. TP53 GA were higher in TMP+ CRNEPC than in TMP+ CRPC whereas GA in PTEN and MYC were similar in comparative groups. GA in AR and ATM were more frequent in CRPC than CRNEPC. The median TMB was higher in CRNEPC than CRPC and higher in TMP- than TMP+ tumors. TMP- CRPC and TMP- CRNEPC had higher TMB levelsthan TMP+ tumors in both groups. MSI-High status was more frequent in the TMP- CRPC and TMP- CRNEPC groups. Conclusions: For CRPC but not CRNEPC, the frequency of TMP+CRPC cases appears lower in advanced vsearly stage disease (TCGA data). CGP reveals significant differences in both targetable GA and markers of immunotherapy response between TMP+ and TMP- CRPC and CRNEC. Thus, when CRPC and CRNEPC areevaluated as to their TMPRSS2:ERG fusion status, significant genomic differences emerge which may impact therapy selection.[Table: see text]


2020 ◽  
Vol 38 (6_suppl) ◽  
pp. 24-24
Author(s):  
Carissa Chu ◽  
Mohammed Alshalalfa ◽  
Martin Sjöström ◽  
Shuang Zhao ◽  
Annika Herlemann ◽  
...  

24 Background: 18F-fluciclovine (Axumin) PET/CT imaging is recommended by the NCCN in the setting of biochemical recurrence, while prostate-specific membrane antigen (PSMA) PET/CT is preferred by the EAU. The utility of these methods in the post-androgen deprivation therapy (ADT) setting however, is less defined. Our objective was to compare relative gene expression of the molecular targets of these imaging modalities— fluciclovine transporter genes (LAT1-4, ASCT1-2) and PSMA—in metastatic castrate resistant prostate cancer (mCRPC) and treatment-emergent small cell/neuroendocrine prostate cancer (t-SCNC). Methods: Genome-wide expression profiles of five mCRPC cohorts (Aggarwal, Grasso, Kumar, Beltran, Robinson, et al) were used to characterize relative expression of fluciclovine transporter (LAT1-4, ASC1-2) and PSMA (FOLH1) genes. 3 cohorts (Kumar, Beltran, Aggarwal) were enriched with t-SCNC tumors. The GSE35988 cohort included primary tumors and mCRPC. RNA expression profiling methods were consistent within cohorts. Results: 518 mCRPC specimens were included. In the GSE35988 cohort, PSMA expression was downregulated in mCRPC when compared to primary localized tumors (p=0.01). PSMA expression was further depressed in t-SCNC when compared with mCRPC (p<0.001). Of the fluciclovine transporter genes, LAT1 and LAT4 were overexpressed in mCRPC when compared to primary tumors, while ASC2 was less expressed (p<0.001). LAT1 was further overexpressed in t-SCNC when compared to mCRPC, while LAT2 was less expressed (p<0.001). PSMA expression was negatively correlated with LAT1 (p<0.001) but positively correlated with LAT2 (p=0.006). Other fluciclovine transporters were not correlated. Conclusions: Expression of PSMA and a subset of fluciclovine transporter genes are inversely correlated in mCRPC and t-SCNC. These findings suggest that fluciclovine-based imaging may play a role in castrate resistant states. Clinical comparison between PSMA- and fluciclovine-based imaging modalities in mCRPC and t-SCNC is warranted.


Cancers ◽  
2021 ◽  
Vol 13 (19) ◽  
pp. 5020
Author(s):  
Girijesh Kumar Patel ◽  
Sayanika Dutta ◽  
Mosharaf Mahmud Syed ◽  
Sabarish Ramachandran ◽  
Monica Sharma ◽  
...  

Deciphering the mechanisms that drive transdifferentiation to neuroendocrine prostate cancer (NEPC) is crucial to identifying novel therapeutic strategies against this lethal and aggressive subtype of advanced prostate cancer (PCa). Further, the role played by exosomal microRNAs (miRs) in mediating signaling mechanisms that propagate the NEPC phenotype remains largely elusive. The unbiased differential miR expression profiling of human PCa cells genetically modulated for TBX2 expression led to the identification of miR-200c-3p. Our findings have unraveled the TBX2/miR-200c-3p/SOX2/N-MYC signaling axis in NEPC transdifferentiation. Mechanistically, we found that: (1) TBX2 binds to the promoter and represses the expression of miR-200c-3p, a miR reported to be lost in castrate resistant prostate cancer (CRPC), and (2) the repression of miR-200c-3p results in the increased expression of its targets SOX2 and N-MYC. In addition, the rescue of mir-200c-3p in the context of TBX2 blockade revealed that miR-200c-3p is the critical intermediary effector in TBX2 regulation of SOX2 and N-MYC. Further, our studies show that in addition to the intracellular mode, TBX2/miR-200c-3p/SOX2/N-MYC signaling can promote NEPC transdifferentiation via exosome-mediated intercellular mechanism, an increasingly recognized and key mode of propagation of the NEPC phenotype.


2020 ◽  
Author(s):  
Lungwani Muungo

The androgen receptor (AR) plays a critical role in the development and the progression of prostate cancer. Alterations in theexpression of AR coregulators lead to AR hypersensitivity, which is one of the mechanisms underlying the progression ofprostate cancer into a castrate-resistant state. Octamer transcription factor 1 (Oct1) is a ubiquitous member of the POUhomeodomainfamily that functions as a coregulator of AR. In our study, the contribution of Oct1 to prostate cancerdevelopment was examined. Immunocytochemistry analysis showed that Oct1 is expressed in the nuclei of LNCaP cells.siRNA-mediated silencing of Oct1 expression inhibited LNCaP cell proliferation. Immunohistochemical analysis of Oct1expression in tumor specimens obtained from 102 patients with prostate cancer showed a positive correlation of Oct1immunoreactivity with a high Gleason score and AR immunoreactivity (p 5 0.0042 and p &lt; 0.0001, respectively). Moreover,patients with high immunoreactivity of Oct1 showed a low cancer-specific survival rate, and those patients with highimmunoreactivities of both Oct1 and AR exhibited poorer cancer-specific prognosis. Multivariate hazard analysis revealed asignificant correlation between high Oct1 immunoreactivity and poor cancer-specific survival (p 5 0.012). These resultsdemonstrate that Oct1 can be a prognostic factor in prostate cancer as a coregulator of AR and may lead to the developmentof a new therapeutic intervention for prostate cancer.


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