Claudia Hube-Magg

SPINK1 expression is tightly linked to 6q15- and 5q21-deleted ERG-fusion negative prostate cancers but unrelated to PSA recurrence.

The serine peptidase inhibitor, Kazal type 1 (SPINK1) has been suggested to define an aggressive molecular subtype of ERG‐fusion negative prostate cancer. It was the aim of this study to further study the clinical relevance of SPINK1 expression and its relationship with other key genomic alterations of prostate cancer.

High lysophosphatidylcholine acyltransferase 1 expression independently predicts high risk for biochemical recurrence in prostate cancers

Lysophosphatidylcholine acyltransferase 1 (LPCAT1) has been suggested to play a role in cancer. To assess its role in prostate cancer, LPCAT1 expression was analyzed on a tissue microarray containing samples from 11,152 prostate cancer patients. In benign prostate glands, LPCAT1 immunostaining was absent or weak. In prostate cancer, LPCAT1 positivity was found in 73.8% of 8786 interpretable tumors including 29.2% with strong expression. Increased LPCAT1 expression was associated with advanced tumor stage (pT3b/T4) (p < 0.0001), high Gleason score (≥4 + 4) (p < 0.0001), positive nodal involvement (p = 0.0002), positive surgical margin (p = 0.0005), and early PSA recurrence (p < 0.0001). High LPCAT1 expression was strongly linked to ERG‐fusion type prostate cancer. Strong LPCAT1 staining was detected in 45.3% of ERG positive but in only 16.7% of ERG negative tumors (p < 0.0001). Within ERG negative cancers, LPCAT1 staining was strongly increased within the subgroup of PTEN deleted cancers (p < 0.0001). Further subgroup analyses revealed that associations of high LPCAT1 expression with PSA recurrence and unfavorable tumor phenotype were largely driven by ERG negative cancers (p < 0.0001) while these effects were substantially mitigated in ERG positive cancers (p = 0.0073). The prognostic impact of LPCAT1 expression was independent of histological and clinical parameters. It is concluded, that LPCAT1 measurement, either alone or in combination, may be utilized for better clinical decision‐making. These data also highlight the potentially important role of lipid metabolism in prostate cancer biology.

High nuclear karyopherin α 2 expression is a strong and independent predictor of biochemical recurrence in prostate cancer patients treated by radical prostatectomy

Increased levels of karyopherin α2 (KPNA2) expression have been described to be linked to poor prognosis in a variety of malignancies. This study was undertaken to evaluate the clinical impact of KPNA2 expression and its association with key genomic alterations in prostate cancers. A tissue microarray containing samples from 11 152 prostate cancers was analyzed for KPNA2 expression by immunohistochemistry. Results were compared with oncological follow-up data and genomic alterations such as TMPRSS2-ERG fusions and deletions of PTEN, 5q21, 6q15 or 3p13. KPNA2 expression was absent or weak in benign prostatic glands and was found to be in weak, moderate or strong intensities in 68.4% of 7964 interpretable prostate cancers. KPNA2 positivity was significantly linked to the presence of ERG rearrangement (P<0.0001). In ERG-negative and -positive prostate cancers, KPNA2 immunostaining was significantly associated with advanced pathological tumor stage (pT3b/pT4), high Gleason grade and early biochemical recurrence (P<0.0001 each). Multivariate analysis including all established prognostic criteria available after surgery revealed that the prognostic role of KPNA2 (P=0.001) was independent of high Gleason grade, advanced pathological tumor stage, high preoperative prostate-specific antigen level and positive surgical margin status (P<0.0001 each). The comparison of KPNA2 expression with deletions of PTEN, 5q21, 6q15 and 3p13 in ERG-positive and -negative cancers revealed a strong link to PTEN deletions in both subgroups (P<0.0001). In conclusion, the strong independent prognostic impact of KPNA2 expression raises the possibility that measurement of KPNA2 expression alone or in combination with other molecular parameters might possibly result in clinically useful information. The data also emphasize a critical role of the functionality of the nuclear import machinery for prostate cancer biology.

Cytoplasmic accumulation of Sequestosome 1 (p62) is a predictor of biochemical recurrence, rapid tumor cell proliferation and genomic instability in prostate cancer

Purpose: Sequestosome 1 (p62) is a multifunctional adapter protein accumulating in autophagy-defective cells. Experimental Design: To evaluate the clinical impact and relationship with key genomic alterations in prostate cancer, p62 protein levels were analyzed by immunohistochemistry on a tissue microarray containing 12,427 prostate cancers. Data on ERG status and deletions of PTEN, 3p13, 5q21, and 6q15 were available from earlier studies. Results: p62 immunostaining was absent in benign prostatic glands but present in 73% of 7,822 interpretable prostate cancers. Strong cytoplasmic p62 staining was tightly linked to high Gleason grade, advanced pathologic tumor (pT) stage, positive nodal status, positive resection margin, and early PSA recurrence (P < 0.0001 each). Increased levels of p62 were significantly linked to TMPRSS2–ERG fusions, both by FISH and immunohistochemical analysis (P < 0.0001 each). For example, moderate or strong p62 immunostaining was seen in 28.5% of cancers with TMPRSS2–ERG fusion detected by FISH and in 23.1% of cancers without such rearrangements (P < 0.0001). Strong p62 staining was significantly linked to the presence of all tested deletions, including PTEN (P < 0.0001), 6q15 (P < 0.0001), 5q21 (P = 0.0002), 3p13 (P = 0.0088), and 6q15 (P < 0.0001), suggesting a link between p62 accumulation and loss of genomic stability. The prognostic role of p62 protein accumulation was striking and independent of Gleason grade, pT stage, pN stage, surgical margin status, and preoperative PSA, regardless of whether preoperative or postoperative parameters were used for modeling. Conclusions: Our study identifies cytoplasmic accumulation of p62 as a strong predictor of an adverse prognostic behavior of prostate cancer independently from established clinicopathologic findings. Clin Cancer Res; 21(15); 3471–9. ©2015 AACR.

High RNA-binding motif protein 3 expression is an independent prognostic marker in operated prostate cancer and tightly linked to ERG activation and PTEN deletions.

BACKGROUND The RNA-binding motif protein 3 (RBM3) has recently been suspected as a prognostic biomarker in several cancers. METHODS RBM3 expression was analysed by immunohistochemistry on a tissue microarray containing 11,152 prostate cancers. RESULTS RBM3 expression was more often detectable in malignant compared to benign prostate. RBM3 immunostaining was found in 64% of the interpretable prostate cancers and was considered strong in 25.6%. High RBM3 expression was linked to advanced tumour stage, high Gleason score, positive nodal involvement and positive surgical margin status (p<0.0001 each). There was a remarkable accumulation of strong RBM3 expression in v-ets avian erythroblastosis virus E26 oncogene homolog (ERG) positive prostate cancers and tumours harbouring PTEN deletions (p<0.0001 each). Moreover, RBM3 staining was tightly related to early biochemical recurrence if all tumours or subgroups of ERG negative and ERG positive cancers were analysed (p<0.0001 each). In multivariate analysis, including RBM3 staining, Gleason grade, pT stage, prostate-specific antigen (PSA), surgical margin status, and nodal status, the prognostic impact of RBM3 staining retained statistically significance (p=0.0084). CONCLUSION Our observations indicate that high RBM3 expression is an independent prognostic marker in prostate cancer. The tight link to ERG activation and PTEN deletions suggest interaction with key molecular pathways in prostate cancer.

HDAC1 overexpression independently predicts biochemical recurrence and is associated with rapid tumor cell proliferation and genomic instability in prostate cancer.

Histone deacetylases (HDACs) play an important role in tumor development and progression by modifying histone and non-histone proteins. In the current study we analyzed prevalence and prognostic impact of HDAC1 in prostate cancer. HDAC1 expression was analyzed by immunohistochemistry on a tissue microarray containing more than 12,400 prostate cancer specimens. Results were compared to tumor phenotype, biochemical recurrence, and molecular subtypes defined by ERG status as well as genomic deletions of 3p, 5q, 6q and PTEN. HDAC1 immunostaining was detectable in 75.4% of 9744 interpretable cancers and considered strong in 15.4%, moderate in 39.4% and weak in 20.7% of cases. High HDAC1 expression was associated with high Gleason grade (p<0.0001), advanced pathological tumor stage (p<0.0001), positive nodal status (p=0.0010), elevated preoperative PSA-level (p=0.0127), early PSA recurrence (p<0.0001) and increased cell proliferation (p<0.0001). Moreover, high-level HDAC1 staining was associated with TMPRSS2:ERG rearrangement and ERG expression in prostate cancers (p<0.0001) and was linked to deletions of PTEN (p<0.0001), 6q (p<0.0001) and 5q (p=0.0028) in ERG-negative cancers. The prognostic impact of HDAC1 was independent of established clinicopathological parameters and was mostly driven by ERG-negative cancers as revealed by subgroup analyses. HDAC1 has strong prognostic impact in prostate cancer and might contribute to the development of a fraction of genetically instable and particularly aggressive prostate cancers. HDAC1 measurement might therefore be of clinical value for risk stratification of prostate cancer and should be further evaluated in this regard.

Overexpression of enhancer of zeste homolog 2 (EZH2) characterizes an aggressive subset of prostate cancers and predicts patient prognosis independently from pre- and postoperatively assessed clinicopathological parameters

Enhancer of zeste homolog 2 (EZH2) plays an important role in tumor development and progression by interacting with histone and nonhistone proteins. In the current study, we analyzed prevalence and prognostic impact of EZH2 in prostate cancer. EZH2 expression was analyzed by immunohistochemistry on a tissue microarray containing more than 12400 prostate cancer specimens. Results were compared to tumor phenotype, biochemical recurrence and molecular subtypes defined by ERG status as well as genomic deletions of 3p, 5q, 6q and PTEN. EZH2 immunostaining was detectable in 56.6% of 10168 interpretable cancers and considered strong in 1.1%, moderate in 12.2% and weak in 43.3% of cases. High EZH2 expression was strongly associated with high Gleason grade (P < 0.0001), advanced pathological tumor stage (P < 0.0001), positive nodal status (P < 0.0001), elevated preoperative PSA level (P = 0.0066), early PSA recurrence (P < 0.0001) and increased cell proliferation P < 0.0001). High-level EZH2 staining was also associated with TMPRSS2:ERG rearrangement and ERG expression in prostate cancers (P < 0.0001) and was linked to deletions of PTEN, 6q15, 5q21 and 3p13 (P < 0.0001 each) particularly in ERG-negative cancers. The prognostic impact of EZH2 was independent of established pre- and postoperatively assessed clinicopathological parameters. EZH2 has strong prognostic impact in prostate cancer and might contribute to the development of a fraction of genetically instable and particularly aggressive prostate cancers. EZH2 analysis might therefore be of clinical value for risk stratification of prostate cancer.

Partial PTEN deletion is linked to poor prognosis in breast cancer

BackgroundDeletions of chromosome 10q23, including the PTEN (phosphatase and tensin homolog) locus, are known to occur in breast cancer, but systematic analyses of its clinical relevance are lacking.MethodsWe thus analyzed a tissue microarray (TMA) with 2,197 breast cancers by fluorescence in-situ hybridization (FISH) using a PTEN-specific probe.ResultsPTEN deletions were detected in 19 % of no special type, 9 % of lobular, 4 % of tubular cancers and 46 % in carcinomas with medullary features. 98.7 % of deletions were heterozygous and only 1.3 % were homozygous. PTEN deletion was significantly linked to advanced tumor stage (p = 0.0054), high-grade (p < 0.0001), high tumor cell proliferation (Ki67 Labeling Index; p < 0.0001), and shortened overall survival (p = 0.0090). PTEN deletions were inversely associated with features of luminal type breast cancers (ER/PR positivity; p < 0.0001 each, and CCND1 amplification; p = 0.0020). PTEN deletions were also strongly linked to amplification of genes involved in the PTEN/AKT pathway such as MYC (p = 0.0430) and HER2 (p = 0.0065). Remarkably the combined analysis of MYC, HER2, CCND1 and PTEN aberrations suggested that aberrations of multiple PTEN/AKT pathway genes have a strong additive effect on breast cancer prognosis. While cancers with one of these aberrations behaved only marginally different from cancers with none, disease outcome was markedly worse in cancers with two or more aberrations as compared to those with only one aberration (p = 0.0002). In addition, the particularly poor prognosis of patients with HER2 amplification and PTEN deletions challenges the concept of PTEN deletions interfering with trastuzumab therapy.ConclusionPTEN deletion occurs in a relevant fraction of breast cancers, and is linked to aggressive tumor behavior. Reduced PTEN function cooperates with MYC and HER2 activation in conferring aggressive phenotype to cancer cells.

Reduced AZGP1 expression is an independent predictor of early PSA recurrence and associated with ERG-fusion positive and PTEN deleted prostate cancers.

Zinc‐alpha 2‐glycoprotein (AZGP1) is involved in lipid metabolism and was suggested as a candidate prognostic biomarker in prostate cancer. To evaluate the clinical impact and relationship with key genomic alterations in prostate cancer, AZGP1 expression was analyzed by immunohistochemistry on a tissue microarray containing 11,152 prostate cancers. Data on ERG status and PTEN, 3p13, 5q21 and 6q15 deletions were available from earlier studies. AZGP1 expression was strong in benign prostatic glands but absent in 38.0% of 8,510 interpretable prostate cancers. Reduced AZGP1 expression was associated with TPMRSS2:ERG fusions, both by FISH and immunohistochemical analysis (p < 0.0001 each). For example, AZGP1 was absent in 54.6% of 2,029 ERG IHC positive but in only 28.1% of 2,398 ERG negative cancers. Irrespective of the ERG status, reduced AZGP1 expression was tightly linked to high Gleason score, advanced pathological tumor stage, positive nodal status and early PSA recurrence (p < 0.0001 each). Reduced AZGP1 expression was also strongly associated with PTEN deletions. AZGP1 immunostaining was lacking in 62.7% of 842 PTEN deleted but in only 37.3% of PTEN non‐deleted cancers but retained strong prognostic influence in both subgroups (p < 0.0001 each). The prognostic role of AZGP1 expression was also independent of Gleason score, pT stage, pN stage, surgical margin status and preoperative PSA, irrespective of whether preoperative or postoperative variables were used for modeling. In conclusion, the results of our study demonstrate that reduced AZGP1 expression is strongly related to adverse prostate cancer prognosis, independently of established clinic‐pathological variables and PTEN deletions.

Up-regulation of mismatch repair genes MSH6, PMS2 and MLH1 parallels development of genetic instability and is linked to tumor aggressiveness and early PSA recurrence in prostate cancer

DNA mismatch repair (MMR) is integral to the maintenance of genetic stability. We aimed to evaluate the clinical impact of MMR gene expression in prostate cancer. The MMR genes MSH6, MLH1 and PMS2 were analyzed by immunohistochemistry on a tissue microarray containing 11152 prostate cancer specimens. Results were compared with ETS-related gene status and deletions of PTEN, 3p13, 5q21 and 6q15. MSH6, MLH1 and PMS2 expression was detectable in 89.5%, 85.4% and 85.0% of cancers and was particularly strong in cancers with advanced pathological tumor stage (P < 0.0001 each), high Gleason grade (P < 0.0001 each), nodal metastasis (P ⩽ 0.0083) and early biochemical recurrence (P < 0.0001). High levels of MMR gene expression paralleled features of genetic instability, such as the number of genomic deletions per cancer; strong expression of all three MMR genes was found in 24%, 29%, 30%, 33% and 42% of cancers with no, one, two, three or four to five deletions (P < 0.0001). The prognostic value of the analyzed MMR genes was largely driven by the subset of cancers lacking ERG fusion (P < 0.0001), while the prognostic impact of MMR gene overexpression was only marginal in ERG-positive cancers. Multivariate analyses suggested an independent prognostic relevance of MMR genes in ERG-negative prostate cancers when compared with prognostic parameters available at the time of initial biopsy. In conclusion, MMR overexpression is common in prostate cancer and is linked to poor outcome as well as features indicating genetic instability. ERG fusion should be analyzed along with MMR gene expression in potential clinical tests.