Human serum and other body fluids are rich resources for the identification of novel biomarkers, which can be measured in routine clinical diagnosis. microRNAs are small non-coding RNA molecules, ...which have an important function in regulating RNA stability and gene expression. The deregulation of microRNAs has been linked to cancer development and tumor progression. Recently, it has been reported that serum and other body fluids contain sufficiently stable microRNA signatures. Thus, the profiles of circulating microRNAs have been explored in a variety of studies aiming at the identification of novel non-invasive biomarkers. In this review, we discuss recent findings indicating that circulating microRNAs are useful as non-invasive biomarkers for different tumor types. Additionally, we summarize the knowledge about the mechanism of microRNA release and the putative functional roles of circulating microRNAs. Although several challenges remain to be addressed, circulating microRNAs have the potential to be useful for the diagnosis and prognosis of cancer diseases.
Circulating miRNAs have recently been indicated as practicable and promising biomarkers for noninvasive diagnosis in various tumor entities. However, cell‐free miRNAs have not been found to correlate ...with clinicopathological variables in epithelial carcinomas. To learn more about the potential clinical relevance of circulating miRNAs in prostate cancer, we screened 667 miRNAs in serum samples from patients with metastatic (n = 7) and localized prostate cancer (n = 14). Various miRNAs were highly abundant in the sera of patients with metastatic disease, and five upregulated miRNAs (miRNA‐375, miRNA‐9*, miRNA‐141, miRNA‐200b and miRNA‐516a‐3p) were selected for further validation. In the first validation study (n = 45), selected miRNAs were analyzed in a prospectively collected serum set taken from different prostate cancer risk groups. Most of the selected miRNAs were significantly correlated with adverse risk factors when different clinicopathological variables were analyzed. Circulating miRNA‐375 and miRNA‐141 turned out to be the most pronounced markers for high‐risk tumors. Their levels also correlated with high Gleason score or lymph‐node positive status in a second independent validation study (n = 71). In addition, the expression levels of miRNA‐375 and miRNA‐141 were monitored in 72 prostate tissue samples (36 tumor vs. 36 benign). Both miRNAs were highly expressed in all samples and significantly upregulated in the tumors compared to normal tissues. Overall, our observations suggest that miRNA‐375 and miRNA‐141 expression is enhanced in prostate cancer specimens and their release into the blood is further associated with advanced cancer disease.
Abstract Objective Cancer cells in the body release soluble and membranous factors that manipulate the tumor environment to facilitate growth and survival. Recent years have provided evidence that ...small microvesicles that are termed exosomes may play a pivotal role in this process. Exosomes are membrane vesicles with a size of 40–100 nm that are released by both tumor and normal cells and can be found in various body fluids. Tumor-derived exosomes carry functional proteins, mRNAs, and miRNAs and could serve as novel platform for tumor diagnosis and prognosis. However, marker proteins that allow enrichment of tumor-derived exosomes over normal exosomes are less well defined. Methods We used Western blot analysis and antibody coupled magnetic beads to characterize CD24 and EpCAM as markers for exosomes. We investigated ovarian carcinoma ascites, pleural effusions and serum of breast carcinoma patients. As non-tumor derived control we used exosomes from ascites of liver cirrhosis patients. Results Exosomes could be isolated from all body fluids and contained marker proteins as well as miRNAs. We observed that CD24 and EpCAM were selectively present on ascites exosomes of tumor patients and copurified together on anti-EpCAM or anti-CD24 magnetic beads. In breast cancer patients CD24 was present but EpCAM was absent from serum exosomes. Instead, the intact EpCAM ectodomain was recovered in a soluble form. We provide evidence that EpCAM can be cleaved from exosomes via serum metalloproteinase(s). Conclusion Loss of EpCAM on serum exosomes may hamper enrichment by immune-affinity isolation. We suggest that CD24 could be an additional marker for the enrichment of tumor-derived exosomes from blood.
Preclinical data suggest the combination of an anti-programmed death receptor 1 antibody plus dabrafenib and trametinib to have superior antitumor activity compared with dabrafenib plus trametinib ...alone. These observations are supported by translational evidence suggesting that immune checkpoint inhibitors plus targeted therapy may improve treatment outcomes in patients with
V600-mutant metastatic melanoma. COMBI-i is a phase III trial evaluating spartalizumab, an anti-programmed death receptor 1 antibody, in combination with dabrafenib and trametinib (sparta-DabTram), versus placebo plus dabrafenib and trametinib (placebo-DabTram) in patients with
V600-mutant unresectable or metastatic melanoma.
Patients received spartalizumab 400 mg intravenously every 4 weeks plus dabrafenib 150 mg orally twice daily and trametinib 2 mg orally once daily or placebo-DabTram. Participants were age ≥ 18 years with unresectable or metastatic
V600-mutant melanoma. The primary end point was investigator-assessed progression-free survival. Overall survival was a key secondary end point (ClinicalTrials.gov identifier: NCT02967692).
At data cutoff (July 1, 2020), the median progression-free survival was 16.2 months (95% CI, 12.7 to 23.9 months) in the sparta-DabTram arm versus 12.0 months (95% CI, 10.2 to 15.4 months) in the placebo-DabTram arm (hazard ratio, 0.82 95% CI, 0.66 to 1.03;
= .042 one-sided; nonsignificant). The objective response rates were 69% (183 of 267 patients) versus 64% (170 of 265 patients), respectively. Grade ≥ 3 treatment-related adverse events occurred in 55% (146 of 267) of patients in the sparta-DabTram arm and 33% (88 of 264) in the placebo-DabTram arm.
The study did not meet its primary end point; broad first-line use of sparta-DabTram is not supported by these results. Further biomarker-driven investigation may identify patient subpopulations who could benefit from checkpoint inhibitor plus targeted therapy combinations.
Modulation of immunologic interactions in cancer tissue is a promising therapeutic strategy. To investigate the immunogenicity of human epidermal growth factor receptor 2 (HER2) -positive and ...triple-negative (TN) breast cancers (BCs), we evaluated tumor-infiltrating lymphocytes (TILs) and immunologically relevant genes in the neoadjuvant GeparSixto trial.
GeparSixto investigated the effect of adding carboplatin (Cb) to an anthracycline-plus-taxane combination (PM) on pathologic complete response (pCR). A total of 580 tumors were evaluated before random assignment for stromal TILs and lymphocyte-predominant BC (LPBC). mRNA expression of immune-activating (CXCL9, CCL5, CD8A, CD80, CXCL13, IGKC, CD21) as well as immunosuppressive factors (IDO1, PD-1, PD-L1, CTLA4, FOXP3) was measured in 481 tumors.
Increased levels of stromal TILs predicted pCR in univariable (P < .001) and multivariable analyses (P < .001). pCR rate was 59.9% in LPBC and 33.8% for non-LPBC (P < .001). pCR rates ≥ 75% were observed in patients with LPBC tumors treated with PMCb, with a significant test for interaction with therapy in the complete (P = .002) and HER2-positive (P = .006), but not the TNBC, cohorts. Hierarchic clustering of mRNA markers revealed three immune subtypes with different pCR rates (P < .001). All 12 immune mRNA markers were predictive for increased pCR. The highest odds ratios (ORs) were observed for PD-L1 (OR, 1.57; 95% CI, 1.34 to 1.86; P < .001) and CCL5 (OR, 1.41; 95% CI, 1.23 to 1.62; P < .001).
Immunologic factors were highly significant predictors of therapy response in the GeparSixto trial, particularly in patients treated with Cb. After further standardization, they could be included in histopathologic assessment of BC.
About 50% of prostate cancers have TMPRSS2-ERG fusions with concurrent ERG overexpression. The aim of this study was to determine whether clinical differences exist between ERG-positive and ...ERG-negative cancers in surgically treated patients not exposed to antihormonal therapy. A secondary aim was to search for differences between these tumor classes.
A tissue microarray containing samples from more than 2,800 prostate cancers with clinical data was analyzed for ERG alterations by immunohistochemistry and FISH. Results were compared with tumor phenotype, biochemical recurrence, and molecular features considered important for prostate cancer. The effect of ERG on androgen receptor (AR)-dependent transcription was analyzed in cell lines.
ERG expression was found in 52.4% of 2,805 cancers with a 95% concordance between ERG expression and ERG gene rearrangement detected by FISH. ERG expression was unrelated to clinical outcome and tumor phenotype. Differences in AMACR, Annexin A3, Bcl2, CD10, ALCAM, chromogranin A, epidermal growth factor receptor, HER2, mTOR, p53, and synaptophysin status were significant but minimal in absolute numbers. The most striking difference was found for AR expression, which was markedly higher in ERG-positive cancers. In vitro studies showed ERG-dependent impairment of AR-mediated transcriptional activity.
The striking similarities between these two types of prostate cancers rules out a major impact of ERG on tumor aggressiveness in early, not hormonally treated cancer. The marked difference in AR levels between ERG-positive and -negative cancers supports a systematic difference in potential response to hormonal therapy as previously observed in clinical trials.
EndoPredict (EP) is an RNA-based multigene test that predicts the likelihood of distant recurrence in patients with estrogen receptor-positive (ER+), human epidermal growth factor receptor 2-negative ...(HER2-) breast cancer (BC) who are being treated with adjuvant endocrine therapy. Herein we report the prospective-retrospective clinical validation of EP in the node-positive, chemotherapy-treated, ER+/HER2- BC patients in the GEICAM 9906 trial.
The patients (N = 1,246) were treated either with six cycles of fluorouracil, epirubicin and cyclophosphamide (FEC) or with four cycles of FEC followed by eight weekly courses of paclitaxel (FEC-P), as well as with endocrine therapy if they had hormone receptor-positive disease. The patients were assigned to EP risk categories (low or high) according to prespecified cutoff levels. The primary endpoint in the clinical validation of EP was distant metastasis-free survival (MFS). Metastasis rates were estimated using the Kaplan-Meier method, and multivariate analysis was performed using Cox regression.
The molecular EP score and the combined molecular and clinical EPclin score were successfully determined in 555 ER+/HER2- tumors from the 800 available samples in the GEICAM 9906 trial. On the basis of the EP, 25% of patients (n = 141) were classified as low risk. MFS was 93% in the low-risk group and 70% in the high-risk group (absolute risk reduction = 23%, hazard ratio (HR) = 4.8, 95% confidence interval (CI) = 2.5 to 9.5; P < 0.0001). Multivariate analysis showed that, in this ER+/HER2- cohort, EP results are an independent prognostic parameter after adjustment for age, grade, lymph node status, tumor size, treatment arm, ER and progesterone receptor (PR) status and proliferation index (Ki67). Using the predefined EPclin score, 13% of patients (n = 74) were assigned to the low-risk group, who had excellent outcomes and no distant recurrence events (absolute risk reduction vs high-risk group = 28%; P < 0.0001). Furthermore, EP was prognostic in premenopausal patients (HR = 6.7, 95% CI = 2.4 to 18.3; P = 0.0002) and postmenopausal patients (HR = 3.3, 95% CI = 1.3 to 8.5; P = 0.0109). There were no statistically significant differences in MFS between treatment arms (FEC vs FEC-P) in either the high- or low-risk groups. The interaction test results between the chemotherapy arm and the EP score were not significant.
EP is an independent prognostic parameter in node-positive, ER+/HER2- BC patients treated with adjuvant chemotherapy followed by hormone therapy. EP did not predict a greater efficacy of FEC-P compared to FEC alone.
Loss of cell cycle control is a prerequisite for cancer onset and progression. In prostate cancer, increased activity of cell cycle genes has been associated with prognostic parameters such as ...biochemical relapse and survival. The identification of novel oncogenic and druggable targets in patient subgroups with poor prognosis may help to develop targeted therapy approaches. We analyzed prostate cancer and corresponding benign tissues (
n
= 98) using microarrays. The comparison of high- and low-grade tumors (Gleason score ≥ 4 + 3 vs. ≤ 3 + 4) revealed 144 differentially expressed genes (
p
< 0.05). Out of these, 15 genes were involved in the cell cycle process. The gene maternal embryonic leucine zipper kinase (
MELK
) was identified to be highly correlated with cell cycle genes like
UBE2C
,
TOP2A
,
CCNB2
, and
AURKB
. Increased
MELK
gene expression in high-risk prostate cancer was validated by qPCR in an independent patient cohort (
p
< 0.005,
n
= 79). Immunohistochemistry analysis using a tissue microarray (
n
= 94) revealed increased MELK protein expression in prostate cancer tissues of high Gleason scores. RNAi-based inhibition of
MELK
in PC3 and LNCaP cells suggested putative function in chromatin modification, embryonic development and cell migration. The concerted inhibition of MELK and other cell cycle targets by the antibiotic siomycin A strongly impaired cell viability of prostate cancer cells, and may point to a novel therapy approach for a subset of high-risk prostate cancer patients.
Immune and targeted therapies achieve long-term survival in metastatic melanoma; however, new treatment strategies are needed to improve patients' outcomes
. We report on the efficacy, safety and ...biomarker analysis from the single-arm safety run-in (part 1; n = 9) and biomarker (part 2; n = 27) cohorts of the randomized, placebo-controlled, phase 3 COMBI-i trial (NCT02967692) of the anti-PD-1 antibody spartalizumab, in combination with the BRAF inhibitor dabrafenib and MEK inhibitor trametinib. Patients (n = 36) had previously untreated BRAF V600-mutant unresectable or metastatic melanoma. In part 1, the recommended phase 3 regimen was identified based on the incidence of dose-limiting toxicities (DLTs; primary endpoint): 400 mg of spartalizumab every 4 weeks plus 150 mg of dabrafenib twice daily plus 2 mg of trametinib once daily. Part 2 characterized changes in PD-L1 levels and CD8
cells following treatment (primary endpoint), and analyzed additional biomarkers. Assessments of efficacy and safety were key secondary endpoints (median follow-up, 24.3 months). Spartalizumab plus dabrafenib and trametinib led to an objective response rate (ORR) of 78%, including 44% complete responses (CRs). Grade ≥3 treatment-related adverse events (TRAEs) were experienced by 72% of patients. All patients had temporary dose modifications, and 17% permanently discontinued all three study drugs due to TRAEs. Early progression-free survival (PFS) events were associated with low tumor mutational burden/T cell-inflamed gene expression signature (GES) or high immunosuppressive tumor microenvironment (TME) GES levels at baseline; an immunosuppressive TME may also preclude CR. Overall, the efficacy, safety and on-treatment biomarker modulations associated with spartalizumab plus dabrafenib and trametinib are promising, and biomarkers that may predict long-term benefit were identified.
TMPRSS2-ERG gene fusions occur in about 50% of all prostate cancer cases and represent promising markers for molecular subtyping. Although TMPRSS2-ERG fusion seems to be a critical event in prostate ...cancer, the precise functional role in cancer development and progression is still unclear.
We studied large-scale gene expression profiles in 47 prostate tumor tissue samples and in 48 normal prostate tissue samples taken from the non-suspect area of clinical low-risk tumors using Affymetrix GeneChip Exon 1.0 ST microarrays.
Comparison of gene expression levels among TMPRSS2-ERG fusion-positive and negative tumors as well as benign samples demonstrated a distinct transcriptional program induced by the gene fusion event. Well-known biomarkers for prostate cancer detection like CRISP3 were found to be associated with the gene fusion status. WNT and TGF-β/BMP signaling pathways were significantly associated with genes upregulated in TMPRSS2-ERG fusion-positive tumors.
The TMPRSS2-ERG gene fusion results in the modulation of transcriptional patterns and cellular pathways with potential consequences for prostate cancer progression. Well-known biomarkers for prostate cancer detection were found to be associated with the gene fusion. Our results suggest that the fusion status should be considered in retrospective and future studies to assess biomarkers for prostate cancer detection, progression and targeted therapy.
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