Genomic profiling of hormone-naïve lymph node metastases in patients with prostate cancer

Low endogenous testosterone levels are associated with the extend of lymphnodal invasion at radical prostatectomy and extended pelvic lymph node dissection

Objective

To investigate clinical factors associated to lymphnodal metastasis load in patients who underwent to radical prostatectomy (RP) and extended pelvic lymph node dissection (ePLND).

Materials and methods

Between November 2014 and December 2019, ET was measured in 617 consecutive patients not under androgen deprivation therapy who underwent RP and ePLND. Lymphnode invasion (LNI) was codified as not present (N = 0) or with one (N = 1) or more than one metastatic node (N > 1). The risk of multiple pelvic lymph node metastasis (N > 1, mPLNM) was assessed by comparing it to the other two groups (N > 1 vs. N = 0 and N > 1 vs. N = 1). Then, we assessed the association between ET and lymphnode invasion for standard predictors, such as PSA, percentage of biopsy positive cores (BPC), tumor stage greater than 1 (cT > 1) and tumor grade group greater than two (ISUP > 2).

Results

Overall, LNI was detected in 70 patients (11.3%) of whom 39 (6.3%) with N = 1 and 31 (5%) with N > 1. On multivariate analysis, ET was inversely associated with the risk of N > 1 when compared to both N = 0 (odds ratio, OR 0.997; CI 0.994–1; p = 0.027) as well as with N = 1 cases (OR 0.994; 95% CI 0.989–1.000; p = 0.015).

Conclusions

In clinical PCa, the risk of mPLNM was increased by low ET levels. As ET decreased, patients had an increased likelihood of mPLNM. Because of the inverse association between ET and mPLNM, higher ET levels were protective against aggressive disease. The influence of locally advanced PCa with high metastatic load on ET levels needs to be explored by controlled trials.

High body mass index predicts multiple prostate cancer lymph node metastases after radical prostatectomy and extended pelvic lymph node dissection

Our aim is to evaluate the association between body mass index (BMI) and preoperative total testosterone (TT) levels with the risk of single and multiple metastatic lymph node invasion (LNI) in prostate cancer patients undergoing radical prostatectomy and extended pelvic lymph node dissection. Preoperative BMI, basal levels of TT, and prostate-specific antigen (PSA) were evaluated in 361 consecutive patients undergoing radical prostatectomy with extended pelvic lymph node dissection between 2014 and 2017. Patients were grouped into either nonmetastatic, one, or more than one metastatic lymph node invasion groups. The association among clinical factors and LNI was evaluated. LNI was detected in 52 (14.4%) patients: 28 (7.8%) cases had one metastatic node and 24 (6.6%) had more than one metastatic node. In the overall study population, BMI correlated inversely with TT (r = −0.256; P < 0.0001). In patients without metastases, BMI inversely correlated with TT (r = −0.282; P < 0.0001). In patients with metastasis, this correlation was lost. In the overall study population, BMI (odds ratio [OR] = 1.268; P = 0.005) was the only independent clinical factor associated with the risk of multiple metastatic LNI compared to cases with one metastatic node. In the nonmetastatic group, TT was lower in patients with BMI >28 kg m⁻² (P < 0.0001). In patients with any LNI, this association was lost (P = 0.232). The median number of positive nodes was higher in patients with BMI >28 kg m⁻² (P = 0.048). In our study, overweight and obese patients had a higher risk of harboring multiple prostate cancer lymph node metastases and lower TT levels when compared to patients with normal BMI.

The FABP12/PPARγ pathway promotes metastatic transformation by inducing epithelial-to-mesenchymal transition and lipid-derived energy production in prostate cancer cells

Early stage localized prostate cancer (PCa) has an excellent prognosis; however, patient survival drops dramatically when PCa metastasizes. The molecular mechanisms underlying PCa metastasis are complex and remain unclear. Here, we examine the role of a new member of the fatty acid‐binding protein (FABP) family, FABP12, in PCa progression. FABP12 is preferentially amplified and/or overexpressed in metastatic compared to primary tumors from both PCa patients and xenograft animal models. We show that FABP12 concurrently triggers metastatic phenotypes (induced epithelial‐to‐mesenchymal transition (EMT) leading to increased cell motility and invasion) and lipid bioenergetics (increased fatty acid uptake and accumulation, increased ATP production from fatty acid β‐oxidation) in PCa cells, supporting increased reliance on fatty acids for energy production. Mechanistically, we show that FABP12 is a driver of PPARγ activation which, in turn, regulates FABP12's role in lipid metabolism and PCa progression. Our results point to a novel role for a FABP‐PPAR pathway in promoting PCa metastasis through induction of EMT and lipid bioenergetics.

Basal total testosterone serum levels predict biopsy and pathological ISUP grade group in a large cohort of Caucasian prostate cancer patients who underwent radical prostatectomy

Aims:

The study aimed to evaluate associations of preoperative total testosterone (TT) with the risk of aggressive prostate cancer (PCA).

Materials & methods:

From 2014 to 2018, basal TT levels were measured in 726 consecutive PCA patients. Patients were classified according to the International Society of Urologic Pathology (ISUP) system. Aggressive PCA was defined by the detection of ISUP > 2 in the surgical specimen. The logistic regression model evaluated the association of TT and other clinical factors with aggressive PCA.

Results:

On univariate analysis, there was a significant association of basal TT with the risk of aggressive PCA as well as age, prostate-specific antigen (PSA), percentage of biopsy positive cores (BPC), tumor clinical stage (cT), and biopsy ISUP grade groups. On multivariate analysis, two models were considered. The first (model I) excluded biopsy ISUP grading groups and the second (model II) included biopsy ISUP grade groups. Multivariate model I, revealed TT as well as all other variables, was an independent predictor of the risk of aggressive disease [odds ratio (OR) = 1.585; 95% confidence interval (CI): 1.113–2.256; p = 0.011]. Elevated basal PSA greater than 20 µg/dl was associated with the risk of aggressive PCA. Multivariate model II revealed that basal TT levels maintain a positive association between aggressive PCA, whereas age, BPC, and clinical stage cT3 lost significance. In the final adjusted model, the level of risk of TT did not change from univariate analysis (OR = 1.525; 95% CI: 1.035–2.245; p = 0.011).

Conclusion:

Elevated preoperative TT levels are associated with the risk of aggressive PCA in the surgical specimen. TT may identify patients who are at risk of aggressive PCA in the low and intermediate European Association of Urology (EAU) risk classes.

Endogenous testosterone mirrors prostate cancer aggressiveness: correlation between basal testosterone serum levels and prostate cancer European Urology Association clinical risk classes in a large cohort of Caucasian patients

OBJECTIVE

To evaluate the association between basal total testosterone (TT) levels with the European Association of Urology (EAU) risk classes at the time of diagnosis of prostate cancer (PCA).

METHODS

A retrospective review of prospectively collected data was carried out between November 2014 and March 2018. Preoperative basal TT levels and PSA were measured in 601 consecutive Caucasian patients who were not under androgen deprivation and undergoing surgery at a tertiary referral center. Patients were classified into low (reference group), intermediate- and high-risk/locally advanced classes. The multinomial logistic regression model evaluated associations of TT and other clinical factors with EAU risk classes.

RESULTS

One hundred twenty four patients (24%) were low risk, 316 (52.6%) were intermediate, 199 (16.5%) were high risk and 42 (7%) were locally advanced. Median circulating basal TT levels increased along EAU classes. TT, PSA, percentage of biopsy-positive cores and tumor clinical stage were independently associated with the high-risk class (odds ratio, OR = 1.002; p = 0.030) but were not associated with intermediate-risk or locally advanced PCA when compared to the low-risk class. TT above the median value was an independent predictor of high-risk class PCA.

CONCLUSIONS

Basal TT levels are positively associated with low, intermediate and high EAU risk classes. The association is significant for the high-risk class when compared to the low-risk group, but was lost in locally advanced risk class. In PCA patients, high TT serum levels are associated with high-risk disease. Endogenous TT should be considered as a biological marker for assessing EAU PCA risk classes.

Expression profiling of primary and metastatic ovarian tumors reveals differences indicative of aggressive disease

The behavior and genetics of serous epithelial ovarian cancer (EOC) metastasis, the form of the disease lethal to patients, is poorly understood. The unique properties of metastases are critical to understand to improve treatments of the disease that remains in patients after debulking surgery. We sought to identify the genetic and phenotypic landscape of metastatic progression of EOC to understand how metastases compare to primary tumors. DNA copy number and mRNA expression differences between matched primary human tumors and omental metastases, collected at the same time during debulking surgery before chemotherapy, were measured using microarrays. qPCR and immunohistochemistry validated findings. Pathway analysis of mRNA expression revealed metastatic cancer cells are more proliferative and less apoptotic than primary tumors, perhaps explaining the aggressive nature of these lesions. Most cases had copy number aberrations (CNAs) that differed between primary and metastatic tumors, but we did not detect CNAs that are recurrent across cases. A six gene expression signature distinguishes primary from metastatic tumors and predicts overall survival in independent datasets. The genetic differences between primary and metastatic tumors, yet common expression changes, suggest that the major clone in metastases is not the same as in primary tumors, but the cancer cells adapt to the omentum similarly. Together, these data highlight how ovarian tumors develop into a distinct, more aggressive metastatic state that should be considered for therapy development.

Biological resonance for cancer metastasis, a new hypothesis based on comparisons between primary cancers and metastases

Many hypotheses have been proposed to try to explain cancer metastasis. However, they seem to be contradictory and have some limitations. Comparisons of primary tumors and matched metastases provide new insight into metastasis. The results show high concordances and minor differences at multiple scales from organic level to molecular level. The concordances reflect the commonality between primary cancer and metastasis, and also mean that metastatic cancer cells derived from primary cancer are quite conservative in distant sites. The differences reflect variation that cancer cells must acquire new traits to adapt to foreign milieu during the course of evolving into a new tumor in second organs. These comparisons also provided new information on understanding mechanism of vascular metastasis, organ-specific metastasis, and tumor dormancy. The collective results suggest a new hypothesis, biological resonance (bio-resonance) model. The hypothesis has two aspects. One is that primary cancer and matched metastasis have a common progenitor. The other is that both ancestors of primary cancer cells and metastatic cancer cells are under similar microenvironments and receive similar or same signals. When their interactions reach a status similar to primary cancer, metastasis will occur. Compared with previous hypotheses, the bio-resonance hypothesis seems to be more applicable for cancer metastasis to explain how, when and where metastasis occurs. Thus, it has important implications for individual prediction, prevention and treatment of cancer metastasis.

Monoallelic expression of TMPRSS2/ERG in prostate cancer stem cells

While chromosomal translocations have a fundamental role in the development of several human leukaemias, their role in solid tumour development has been somewhat more controversial. Recently, it was shown that up to 80% of prostate tumours harbour at least one such gene fusion, and that the most common fusion event, between the prostate-specific TMPRSS2 gene and the ERG oncogene, is a critical, and probably early factor in prostate cancer development. Here we demonstrate the presence and expression of this significant chromosomal rearrangement in prostate cancer stem cells. Moreover, we show that in the prostate epithelial hierarchy from both normal and tumour tissues, TMPRSS2 transcription is subjected to tight monoallelic regulation, which is retained upon asymmetric division and relaxed during epithelial cell differentiation. The presence and expression of TMPRSS2/ERG in prostate stem cells would provide ERG-driven survival advantages, allowing maintenance of this mutated genotype.

Identification of ovarian cancer metastatic miRNAs

Serous epithelial ovarian cancer (EOC) patients often succumb to aggressive metastatic disease, yet little is known about the behavior and genetics of ovarian cancer metastasis. Here, we aim to understand how omental metastases differ from primary tumors and how these differences may influence chemotherapy. We analyzed the miRNA expression profiles of primary EOC tumors and their respective omental metastases from 9 patients using miRNA Taqman qPCR arrays. We find 17 miRNAs with differential expression in omental lesions compared to primary tumors. miR-21, miR-150, and miR-146a have low expression in most primary tumors with significantly increased expression in omental lesions, with concomitant decreased expression of predicted mRNA targets based on mRNA expression. We find that miR-150 and miR-146a mediate spheroid size. Both miR-146a and miR-150 increase the number of residual surviving cells by 2-4 fold when challenged with lethal cisplatin concentrations. These observations suggest that at least two of the miRNAs, miR-146a and miR-150, up-regulated in omental lesions, stimulate survival and increase drug tolerance. Our observations suggest that cancer cells in omental tumors express key miRNAs differently than primary tumors, and that at least some of these microRNAs may be critical regulators of the emergence of drug resistant disease.

KCTD9 contributes to liver injury through NK cell activation during hepatitis B virus-induced acute-on-chronic liver failure

We explored the expression of a newly identified potassium channel tetramerisation domain containing 9 (KCTD9) protein in 113 blood and 81 liver samples, from patients with mild chronic hepatitis B (CHB) or HBV-induced acute-on-chronic liver failure (HBV-ACLF). KCTD9 was highly expressed in peripheral and hepatic NK cells from HBV-ACLF patients compared with mild CHB patients, and this correlated positively with the severity of liver injury. The role of KCTD9 was further investigated in NK92 cells in vitro. KCTD9 overexpressed NK92 cells exhibited a marked increase in CD69 expression, cytotoxicity, IFN-γ secretion and a significant decrease in NKG2A receptor expression. Inhibition of KCTD9 by shRNA resulted in reduced cytotoxic function. These results suggest the involvement of KCTD9 in NK cell activation and provide additional insight into a potential therapeutic target for molecular manipulation for HBV-ACLF patients.

Challenges in identifying candidate amplification targets in human cancers: chromosome 8q21 as a case study

Detailed genomic characterization of cancer specimens is required to identify all genes whose dysregulation contributes to tumorigenesis and/or tumor progression. These include amplification target genes, whose oncogenic functions derive from their overexpression in response to increased gene copy number, and which increasingly serve as therapeutic targets and predictive markers. We propose that identifying novel amplification target genes is becoming more challenging, and may require the comparative analysis of multiple studies mapping gene copy number changes and/or defining associations between gene copy number and expression. We therefore reviewed the array comparative genomic hybridization and single nucleotide polymorphism profiling literature to identify copy number increases that were restricted to chromosome 8q21 in human cancers, which were reported most frequently in breast cancer. We determined the minimal regions of overlap between gained regions and then examined which chromosome 8q21 genes were most frequently overexpressed, or otherwise supported, in individual studies. As these combined approaches supported the previously proposed amplification targets TCEB1, TPD52, and WWP1, the comparison of multiple genomic studies may therefore effectively predict candidate gene amplification targets, and prioritize these for further study.

ERG rearrangement for predicting subsequent cancer diagnosis in high-grade prostatic intraepithelial neoplasia and lymph node metastasis

PURPOSE

We aimed to analyze whether ERG rearrangement in biopsies could be used to assess subsequent cancer diagnosis in high-grade prostatic intraepithelial neoplasia (HGPIN) and the risk of lymph node metastasis in early prostate cancer.

EXPERIMENTAL DESIGN

Samples from 523 patients (361 with early prostate cancer and 162 with HGPIN) were collected prospectively. On the basis of the cutoff value established previously, the 162 patients with HGPIN were stratified to two groups: one with an ERG rearrangements rate ≥1.6% (n = 59) and the other with an ERG rearrangements rate <1.6% (n = 103). For the 361 prostate cancer cases undergoing radical prostatectomy, 143 had pelvic lymph node dissection (node-positive, n = 56 and node-negative, n = 87). All ERG rearrangement FISH data were validated with ERG immunohistochemistry.

RESULTS

A total of 56 (of 59, 94.9%) HGPIN cases with an ERG rearrangements rate ≥1.6% and 5 (of 103, 4.9%) HGPIN cases with an ERG rearrangements rate <1.6% were diagnosed with prostate cancer during repeat biopsy follow-ups (P < 0.001). There were significant differences in ERG rearrangement rates between lymph node-positive and -negative prostate cancer (P < 0.001). The optimal cutoff value to predict lymph node metastasis by ERG rearrangement was established, being 2.6% with a sensitivity at 80.4% [95% confidence interval (CI), 67.6-89.8] and a specificity at 85.1% (95% CI, 75.8-91.8). ERG protein expression by immunohistochemistry was highly concordant with ERG rearrangement by FISH.

CONCLUSIONS

The presence of ERG rearrangement in HGPIN lesions detected on initial biopsy warrants repeat biopsies and measuring ERG rearrangement could be used for assessing the risk of lymph node metastasis in early prostate cancer.

ERG rearrangement metastasis patterns in locally advanced prostate cancer

OBJECTIVES

To interrogate multifocal prostate cancer (PCa) to determine its predilection for metastasis, using ERG rearrangement as marker of clonality. A hallmark of PCa is that distinct tumor foci may arise independently, which has important biological and clinical implications. Recent studies characterizing ERG-rearranged PCa possessing intrafocal homogeneity but interfocal heterogeneity support this hypothesis.

METHODS

We studied 26 patients who underwent prostatectomy and lymphadenectomy with at least 2 distinct PCa foci and 1 lymph node (LN) metastasis. Each focus was assessed for size, Gleason score, ERG rearrangement, and TMPRSS2-ERG transcript.

RESULTS

Fifteen of 26 cases exhibited interfocal homogeneity with regard to ERG rearrangement (ie, presence vs absence of ERG rearrangement). ERG rearrangement was present in all foci for 6 and absent in all foci for 9 cases. Two cases revealed interfocal heterogeneity with regard to rearrangement mechanism (ie, rearrangement through insertion or deletion). Eight of 26 cases revealed interfocal heterogeneity with regard to rearrangement status. In all cases with at least 1 ERG rearranged focus, we found the corresponding LN metastasis harboring an ERG rearrangement. Interestingly, in a subset of cases the rearrangement status in the LN did not correspond to size or Gleason score. All but 2 ERG rearranged foci had detectable TMPRSS2-ERG transcript levels.

CONCLUSIONS

When multifocal PCa demonstrates both ERG-positive and ERG-negative foci, the positive foci have a greater predilection for metastasis. Larger studies are needed to confirm the potential additional risk an ERG rearranged focus confers on the likelihood of disease progression.

DNA copy number aberrations in breast cancer by array comparative genomic hybridization

Array comparative genomic hybridization (CGH) has been popularly used for analyzing DNA copy number variations in diseases like cancer. In this study, we investigated 82 sporadic samples from 49 breast cancer patients using 1-Mb resolution bacterial artificial chromosome CGH arrays. A number of highly frequent genomic aberrations were discovered, which may act as “drivers” of tumor progression. Meanwhile, the genomic profiles of four “normal” breast tissue samples taken at least 2 cm away from the primary tumor sites were also found to have some genomic aberrations that recurred with high frequency in the primary tumors, which may have important implications for clinical therapy. Additionally, we performed class comparison and class prediction for various clinicopathological parameters, and a list of characteristic genomic aberrations associated with different clinicopathological phenotypes was compiled. Our study provides clues for further investigations of the underlying mechanisms of breast carcinogenesis.

Neoplasia: the second decade

This issue marks the end of the 10-year anniversary of Neoplasia where we have seen exciting growth in both number of submitted and published articles in Neoplasia. Neoplasia was first published in 1999. During the past 10 years, Neoplasia has dynamically adapted to the needs of the cancer research community as technologies have advanced. Neoplasia is currently providing access to articles through PubMed Central to continue to facilitate rapid broad-based dissemination of published findings to the scientific community through an Open Access model. This has in part helped Neoplasia to achieve an improved impact factor this past year, demonstrating that the manuscripts published by Neoplasia are of great interest to the overall cancer research community. This past year, Neoplasia received a record number of articles for review and has had a 21% increase in the number of published articles.

Homozygous deletions and recurrent amplifications implicate new genes involved in prostate cancer

Prostate cancer cell lines provide ideal in vitro systems for the identification and analysis of prostate tumor suppressors and oncogenes. A detailed characterization of the architecture of prostate cancer cell line genomes would facilitate the study of precise roles of various genes in prostate tumorigenesis in general. To contribute to such a characterization, we used the GeneChip 500K single nucleotide polymorphic (SNP) array for analysis of genotypes and relative DNA copy number changes across the genome of 11 cell lines derived from both normal and cancerous prostate tissues. For comparison purposes, we also examined the alterations observed in the cell lines in tumor/normal pairs of clinical samples from 72 patients. Along with genome-wide maps of DNA copy number changes and loss of heterozygosity for these cell lines, we report previously unreported homozygous deletions and recurrent amplifications in prostate cancers in this study. The homozygous deletions affected a number of biologically important genes, including PPP2R2A and BNIP3L identified in this study and CDKN2A/CDKN2B reported previously. Although most amplified genomic regions tended to be large, amplifications at 8q24.21 were of particular interest because the affected regions are relatively small, are found in multiple cell lines, are located near MYC, an oncogene strongly implicated in prostate tumorigenesis, and are known to harbor SNPs that are associated with inherited susceptibility for prostate cancer. The genomic alterations revealed in this study provide an important catalog of positional information relevant to efforts aimed at deciphering the molecular genetic basis of prostate cancer.

High resolution oligonucleotide CGH using DNA from archived prostate tissue

BACKGROUND

The current focus on biomarker discovery is a result of an improved understanding of the biological basis for carcinogenesis and advances in technology. Biomarkers can aid in diagnosis, prognosis, treatment selection, and drug development. There is an urgent need for high-resolution tools that perform well using archived tissue for biomarker discovery and tools that can translate into the clinic.

METHODS

Oligonucleotide array comparative genomic hybridization (oCGH) was compared to BAC-based aCGH using unamplified total genomic DNA from formalin fixed paraffin-embedded (FFPE) prostate tissue.

RESULTS

The copy number aberrations detected with the BAC and oligonucleotide arrays were highly correlated in cases where the arrays contained probes in similar genomic locations. The oligonucleotide array platform provided more precise mapping due to the higher density of oligonucleotide probes.

CONCLUSIONS

These results demonstrate the utility of high-resolution oligonucleotide arrays designed to use genomic DNA for CGH measurements using archived tissue samples for discovery and clinic based assays.