Loss of copy numbers of retrotransposons (HERVK) on chromosome 7p11.2 impacts EGFR (Epidermal Growth Factor Receptor)-induced phenotypes for platinum sensitivity and long-term survival in ovarian cancer-A study from the OVCAD consortium.

We analyzed variations in the epidermal growth factor receptor (EGFR) gene and 5'-upstream region to identify potential molecular predictors of treatment response in primary epithelial ovarian cancer. Tumor tissues collected during debulking surgery from the prospective multicenter OVCAD study were investigated. Copy number variations in the human endogenous retrovirus sequence human endogenous retrovirus K9 (HERVK9) and EGFR Exons 7 and 9, as well as repeat length and loss of heterozygosity of polymorphic CA-SSR I and relative EGFR mRNA expression were determined quantitatively. At least one EGFR variation was observed in 94% of the patients. Among the 30 combinations of variations discovered, enhanced platinum sensitivity (n = 151) was found dominantly with HERVK9 haploidy and Exon 7 tetraploidy, overrepresented among patients with survival ≥120 months (24/29, p = .0212). EGFR overexpression (≥80 percentile) was significantly less likely in the responders (17% vs. 32%, p = .044). Multivariate Cox regression analysis, including age, FIGO stage, and grade, indicated that the patients' subgroup was prognostically significant for CA-SSR I repeat length <18 CA for both alleles (HR 0.276, 95% confidence interval 0.109-0.655, p = .001). Although EGFR variations occur in ovarian cancer, the mRNA levels remain low compared to other EGFR-mutated cancers. Notably, the inherited length of the CA-SSR I repeat, HERVK9 haploidy, and Exon 7 tetraploidy conferred three times higher odds ratio to survive for more than 10 years under therapy. This may add value in guiding therapies if determined during follow-up in circulating tumor cells or circulating tumor DNA and offers HERVK9 as a potential therapeutic target.

Low Tumor-to-Stroma Ratio Reflects Protective Role of Stroma against Prostate Cancer Progression.

Tumor-to-stroma ratio (TSR) is a prognostic factor that expresses the relative amounts of tumor and intratumoral stroma. In this study, its clinical and molecular relevance was evaluated in prostate cancer (PCa). The feasibility of automated quantification was tested in digital scans of tissue microarrays containing 128 primary tumors from 72 PCa patients stained immunohistochemically for epithelial cell adhesion molecule (EpCAM), followed by validation in a cohort of 310 primary tumors from 209 PCa patients. In order to investigate the gene expression differences between tumors with low and high TSR, we applied multigene expression analysis (nCounter® PanCancer Progression Panel, NanoString) of 42 tissue samples. TSR scores were categorized into low (<1 TSR) and high (≥1 TSR). In the pilot cohort, 31 patients (43.1%) were categorized as low and 41 (56.9%) as high TSR score, whereas 48 (23.0%) patients from the validation cohort were classified as low TSR and 161 (77.0%) as high. In both cohorts, high TSR appeared to indicate the shorter time to biochemical recurrence in PCa patients (Log-rank test, p = 0.04 and p = 0.01 for the pilot and validation cohort, respectively). Additionally, in the multivariate analysis of the validation cohort, TSR predicted BR independent of other factors, i.e., pT, pN, and age (p = 0.04, HR 2.75, 95%CI 1.07-7.03). Our data revealed that tumors categorized into low and high TSR score show differential expression of various genes; the genes upregulated in tumors with low TSR score were mostly associated with extracellular matrix and cell adhesion regulation. Taken together, this study shows that high stroma content can play a protective role in PCa. Automatic EpCAM-based quantification of TSR might improve prognostication in personalized medicine for PCa.

Longitudinal Analysis of Circulating Tumor Cells in Colorectal Cancer Patients by a Cytological and Molecular Approach: Feasibility and Clinical Application.

INTRODUCTION: Liquid biopsies allowing for individualized risk stratification of cancer patients have become of high significance in individualized cancer diagnostics and treatment. The detection of circulating tumor cells (CTC) has proven to be highly relevant in risk prediction, e.g., in colorectal cancer (CRC) patients. In this study, we investigate the clinical relevance of longitudinal CTC detection over a course of follow-up after surgical resection of the tumor and correlate these findings with clinico-pathological characteristics. METHODS: In total, 49 patients with histologically proven colorectal carcinoma were recruited for this prospective study. Blood samples were analyzed for CTC presence by two methods: first by marker-dependent immunofluorescence staining combined with automated microscopy with the NYONE® cell imager and additionally, indirectly, by semi-quantitative Cytokeratin-20 (CK20) RT-qPCR. CTC quantification data were compared and correlated with the clinico-pathological parameters. RESULTS: Detection of CTC over a post-operative time course was feasible with both applied methods. In patients who were pre-operatively negative for CTCs with the NYONE® method or below the cut-off for relative CK20 mRNA expression after analysis by PCR, a statistically significant rise in the immediate post-operative CTC detection could be demonstrated. Further, in the cohort analyzed by PCR, we detected a lower CTC load in patients who were adjuvantly treated with chemotherapy compared to patients in the follow-up subgroup. This finding was contrary to the same patient subset analyzed with the NYONE® for CTC detection. CONCLUSION: Our study investigates the occurrence of CTC in CRC patients after surgical resection of the primary tumor and during postoperative follow-up. The resection of the tumor has an impact on the CTC quantity and the longitudinal CTC analysis supports the significance of CTC as a prognostic biomarker. Future investigations with an even more extended follow-up period and larger patient cohorts will have to validate our results and may help to define an optimal longitudinal sampling scheme for liquid biopsies in the post-operative monitoring of cancer patients to enable tailored therapy concepts for precision medicine.

The Long-Term Prognostic Significance of Circulating Tumor Cells in Ovarian Cancer-A Study of the OVCAD Consortium.

INTRODUCTION: We previously reported the prognostic impact of circulating tumor cells (CTCs) in a multicenter study on minimal residual disease in primary ovarian cancer. With additional follow-up data, we evaluated the combined CTC approach (CTCscombo), in particular for the patients who had survived more than five years. MATERIAL AND METHODS: Blood samples taken at baseline and six months after adjuvant treatment (follow-up) were assessed by quantitative PCR (qPCR) measuring PPIC transcripts and immunofluorescent staining (IF). A positive result with either IF or qPCR was classified as CTCcombo-positive. Further, PPIC was assessed in the primary tumor tissue. RESULTS: The concordance of IF and qPCR was 65% at baseline and 83% after treatment. Results showed that 50.5% of the baseline and 29.5% of the follow-up samples were CTCcombo-positive. CTCscombo after treatment were associated with increased mortality after adjusting for FIGO stage (HR 2.574, 95% CI: 1.227-5.398, p = 0.012), a higher risk of recurrence after adjusting for peritoneal carcinosis (HR 4.068, 95% CI: 1.948-8.498, p < 0.001), and increased mortality after five survived years. DISCUSSION: The two-sided analytical approach revealed CTC subpopulations associated with ovarian cancer progression and may illuminate a potential treatment-related shift in molecular phenotypes. That approach can identify patients who have elevated risk of recurrence and death due to ovarian cancer and who may require risk-adapted treatment strategies.

Longitudinal Multi-omics Analyses Identify Responses of Megakaryocytes, Erythroid Cells, and Plasmablasts as Hallmarks of Severe COVID-19.

Temporal resolution of cellular features associated with a severe COVID-19 disease trajectory is needed for understanding skewed immune responses and defining predictors of outcome. Here, we performed a longitudinal multi-omics study using a two-center cohort of 14 patients. We analyzed the bulk transcriptome, bulk DNA methylome, and single-cell transcriptome (>358,000 cells, including BCR profiles) of peripheral blood samples harvested from up to 5 time points. Validation was performed in two independent cohorts of COVID-19 patients. Severe COVID-19 was characterized by an increase of proliferating, metabolically hyperactive plasmablasts. Coinciding with critical illness, we also identified an expansion of interferon-activated circulating megakaryocytes and increased erythropoiesis with features of hypoxic signaling. Megakaryocyte- and erythroid-cell-derived co-expression modules were predictive of fatal disease outcome. The study demonstrates broad cellular effects of SARS-CoV-2 infection beyond adaptive immune cells and provides an entry point toward developing biomarkers and targeted treatments of patients with COVID-19.

Isolation and Enumeration of CTC in Colorectal Cancer Patients: Introduction of a Novel Cell Imaging Approach and Comparison to Cellular and Molecular Detection Techniques.

Circulating tumour cells (CTC) were proven to be prognostically relevant in cancer treatment, e.g., in colorectal cancer (CRC). This study validates a molecular detection technique through using a novel cell imaging approach for CTC detection and enumeration, in comparison to a size-based cellular and correlated the data to clinico-pathological characteristics. Overall, 57 CRC patients were recruited for this prospective study. Blood samples were analysed for CTCs by three methods: (1) Epithelial marker immunofluorescence staining combined with automated microscopy using the NYONE® cell imager; (2) isolation by size using membrane filtration with the ScreenCell® Cyto IS device and immunofluorescence staining; (3) detection by semi-quantitative Cytokeratin-20 RT-qPCR. Enumeration data were compared and correlated with clinic-pathological parameters. CTC were detected by either approach; however, with varying positivity rates: NYONE® 36.4%, ScreenCell® 100%, and PCR 80.5%. All methods revealed a positive correlation of CTC presence and higher tumour burden, which was most striking using the ScreenCell® device. Generally, no intercorrelation of CTC presence emerged amongst the applied techniques. Overall, enumeration of CTC after isolation by size demonstrated to be the most reliable strategy for the detection of CTC in CRC patients. Ongoing studies will have to unravel the prognostic value of this finding, and validate this approach in a larger cohort.

EGFR as a stable marker of prostate cancer dissemination to bones.

BACKGROUND: Prostate cancer (PCa) is among the most commonly diagnosed malignancies in men. Although 5-year survival in patients with localised disease reaches nearly 100%, metastatic disease still remains incurable. Therefore, there is a need for markers indicating metastatic dissemination. METHODS: EGFR overexpression (EGFRover) was tracked in 1039 primary tumours, circulating tumour cells from 39 d'Amico high-risk patients and metastatic samples from 21 castration-resistant PCa cases. EGFR status was compared to clinical parameters and multiple molecular factors were assessed using immunohistochemistry and gene ontology analysis. The functional aspect of EGFR was evaluated by plating PC-3 cells on soft and rigid matrices. RESULTS: EGFRover was found in 14% of primary tumours, where it was associated with shorter metastasis-free survival and was an independent indicator of worse overall survival. EGFRover correlated with a pro-migratory and pro-metastatic phenotype of tumour cells as well as rich collagen fibre content. All circulating tumour cells (detected in 13% of cases) were positive for EGFR, independent of their EMT-related phenotype. EGFRover was more prevalent in castration-resistant bone metastases (29% of patients) and supported growth of human PCa cells on rigid matrices mimicking bone stiffness. CONCLUSIONS: EGFRover is a stable, EMT-independent marker of PCa disseminating to rigid organs, preferentially bones.

Low Numbers of Vascular Vessels Correlate to Progression in Hormone-Naïve Prostate Carcinomas Undergoing Radical Prostatectomy.

Vascularization influences tumor development by supporting the nutrition and dissemination of tumor cells. On the other hand, a low number of vascular vessels (VVlow) may induce hypoxia, accounting for selection of resistant clone(s) of tumor cells. This study aimed to evaluate the prognostic significance of vascular (VV) and lymphatic vessels (LV) in prostate cancer (PCa). Tumor samples from 400 PCa patients undergoing radical prostatectomy (RP) were prepared in duplex as tissue microarrays. Numbers of VV and LV were evaluated using immunohistochemistry detecting CD34 and podoplanin, respectively, and correlated to clinical data, biochemical recurrence (BR), and proteins analyzed in tumor cells. VVlow and LV were found in 32% and 43% of patients with informative PCa samples, respectively. VVlow correlated with a shorter time to BR 3, 5, and 10 years after RP in hormone-naïve patients (p = 0.028, p = 0.027 and p = 0.056, respectively). It was also shown to be an independent prognostic factor 5 years after surgery (multivariate analysis, p = 0.046). Tumors characterized by VVlow expressed the epithelial cell adhesion molecule, EpCAM, less frequently (p = 0.016) and revealed a borderline correlation to increased levels of tumor cell invasion marker Loxl-2 (p = 0.059). No correlations were found for LV. In summary, VVlow in hormone-naïve patients undergoing RP has prognostic potential and seems to be related to an aggressive phenotype of tumor cells.

Somatic aberrations of BRCA1 gene are associated with ALDH1, EGFR, and tumor progression in prostate cancer.

BRCA1 is a pivotal tumor suppressor. Its dysfunction is known to play a role in different tumors. Among others, BRCA1 germline mutations account for higher risk and more aggressive course of prostate cancer (PCa). In addition, somatic BRCA1 gene loss was demonstrated to be a signature of PCa dissemination to lymph nodes and peripheral blood, and indicate worse clinical outcome. In order to substantiate the data for BRCA1 gene loss in PCa and reveal its phenotypical background, BRCA1 gene status was assessed in a large cohort of PCa patients and compared to different molecular factors. BRCA1 gene dosage was assessed in 2398 tumor samples from 1,199 PCa patients using fluorescent in situ hybridization. It was compared to clinico-pathological parameters, patients' outcome as well as selected proteins (Ki-67, apoptosis marker, cytokeratins, vimentin, E- and N-cadherin, ALDH1 and EGFR) examined immunohistochemically. BRCA1 losses were found in 10%, whereas gains appeared in 7% of 603 informative PCa patients. BRCA1 losses correlated to higher T stage (p = 0.027), Gleason score (p = 0.039), shorter time to biochemical recurrence in patients with Gleason score > 7 independently of other factors (multivariate analysis, p = 0.005) as well as expression of proteins regulating stemness and epithelial-mesenchymal transition, that is, ALDH1 (p = 0.021) and EGFR (p = 0.011), respectively. BRCA1 gains correlated to shorter time to metastasis (p = 0.012) and expression of ALDH1 (p = 0.014). These results support the assumption that BRCA1 gene losses contribute to a progressive and stem cell-like phenotype of PCa. Furthermore, they reveal that also BRCA1 gain conceivably representing loss-of-function might mark more invasive tumors.

ALDH1-positive intratumoral stromal cells indicate differentiated epithelial-like phenotype and good prognosis in prostate cancer.

Aldehyde dehydrogenase 1 (ALDH1) characterizes tumor-initiating cells in solid tumors; however, little is known about its expression in intratumoral stromal cells. Herein, we aimed to dissect its potential dual relevance in prostate cancer (PCa). ALDH1 expression was evaluated immunohistochemically in tumor and stromal cells in primary PCa and metastases. It was correlated to clinico-pathologic parameters, patients' outcome, and selected proteins (CK5/6, CK14, CK8/18, CK19, EpCAM, Ki-67, E-cadherin, N-cadherin, and vimentin). ALDH1 protein was detected in tumor and stromal cells in 16% and 67% of 348 primary PCa, respectively. Tumor cell ALDH1 expression was associated with advanced T stage (P = 0.009), higher Gleason score (P = 0.016), shorter time to biochemical recurrence (TBR P = 0.010) and CK14 expression (P = 0.023). Stromal cell ALDH1 expression correlated to lower T stage (P = 0.008) and Gleason score (P = 0.016), N0 stage (P = 0.017), and longer TBR (P = 0.017). It occurred to be an independent predictor of good prognosis in the subgroup of d'Amico high-risk patients (multivariate analysis, P = 0.050). ALDH1-positive stromal cells were found in tumors characterized frequently by CK8/18 (P = 0.033) or EpCAM expression (P < 0.001) and rarely by epithelial-mesenchymal transition defined as CK8/18(-)vimentin(+) phenotype (P = 0.003). ALDH1-positive tumor and stromal cells were detected in 33% and 41% of hormone naive lymph node metastases (n = 63), 52% and 24% of castration resistant bone metastases, as well as 89% and 28% of castration resistant visceral metastases (n = 21), respectively. We have determined that contrary to tumor cell ALDH1, the presence of stromal ALDH1 is associated with epithelial phenotype of primary PCa, improved clinical outcome, and is less frequent in PCa metastases.

Circulating tumor cells: potential markers of minimal residual disease in ovarian cancer? a study of the OVCAD consortium.

PURPOSE: In 75% of ovarian cancer patients the tumor mass is completely eradicated by established surgical and cytotoxic treatment; however, the majority of the tumors recur within 24 months. Here we investigated the role of circulating tumor cells (CTCs) indicating occult tumor load, which remains inaccessible by established diagnostics. EXPERIMENTAL DESIGN: Blood was taken at diagnosis (baseline samples, n = 102) and six months after completion of adjuvant first-line chemotherapy (follow-up samples; n = 78). CTCs were enriched by density gradient centrifugation. A multi-marker immunostaining was established and further complemented by FISH on CTCs and tumor/metastasis tissues using probes for stem-cell like fusion genes MECOM and HHLA1. RESULTS: CTCs were observed in 26.5% baseline and 7.7% follow-up blood samples at a mean number of 12.4 and 2.8 CTCs per ml blood, respectively. Baseline CTCs indicated a higher risk of death in R0 patients with complete gross resection (univariate: HR 2.158, 95% CI 1.111-4.191, p = 0.023; multivariate: HR 2.720, 95% CI 1.340-5.522, p = 0.006). At follow-up, the presence of CTCs was associated with response to primary treatment as assessed using RECIST criteria. Chromosomal gains at MECOM and HHLA1 loci suggest that the observed cells were cancer cells and reflect pathophysiological decisive chromosomal aberrations of the primary and metastatic tumors. CONCLUSIONS: Our data suggest that CTCs detected by the multi-marker protein panel and/or MECOM/HHLA1 FISH represent minimal residual disease in optimally debulked ovarian cancer patients. The role of CTCs cells especially for clinical therapy stratification of the patients has to be validated in consecutive larger studies applying standardized treatment schemes.

Exploring prostate cancer genome reveals simultaneous losses of PTEN, FAS and PAPSS2 in patients with PSA recurrence after radical prostatectomy.

The multifocal nature of prostate cancer (PCa) creates a challenge to patients' outcome prediction and their clinical management. An approach that scrutinizes every cancer focus is needed in order to generate a comprehensive evaluation of the disease, and by correlating to patients' clinico-pathological information, specific prognostic biomarker can be identified. Our study utilized the Affymetrix SNP 6.0 Genome-wide assay to investigate forty-three fresh frozen PCa tissue foci from twenty-three patients. With a long clinical follow-up period that ranged from 2.0-9.7 (mean 5.4) years, copy number variation (CNV) data was evaluated for association with patients' PSA status during follow-up. From our results, the loss of unique genes on 10q23.31 and 10q23.2-10q23.31 were identified to be significantly associated to PSA recurrence (p < 0.05). The implication of PTEN and FAS loss (10q23.31) support previous reports due to their critical roles in prostate carcinogenesis. Furthermore, we hypothesize that the PAPSS2 gene (10q23.2-10q23.31) may be functionally relevant in post-operative PSA recurrence because of its reported role in androgen biosynthesis. It is suggestive that the loss of the susceptible region on chromosome 10q, which implicates PTEN, FAS and PAPSS2 may serve as genetic predictors of PSA recurrence after radical prostatectomy.

AKT3 regulates ErbB2, ErbB3 and estrogen receptor α expression and contributes to endocrine therapy resistance of ErbB2(+) breast tumor cells from Balb-neuT mice.

ErbB2(+) breast cancer is an aggressive breast cancer subtype generally associated with lower estrogen receptor alpha (ERα) expression and more aggressive tumor behavior compared to ERα(+)/ErbB2(-) breast cancer. The ErbB2(+) phenotype is associated with resistance to endocrine therapy, e.g. the selective estrogen receptor modulator Tamoxifen. However, the mechanisms underlying endocrine resistance are not fully understood. Here, we investigated the impact of AKT signaling and distinct functional roles of AKT isoforms in ErbB2(+) breast cancer from Balb-neuT mice. AKT isoform specific in vitro kinase assays revealed that AKT3 is activated in Balb-neuT breast tumors in comparison to normal murine breast tissue. Knock-down of AKT3, but not of AKT1 or AKT2, led to reduced expression and tyrosine-phosphorylation of ErbB2 and ErbB3 in Balb-neuT-derived mammary tumor cells. In contrast, expression of ERα was strongly up-regulated and phosphorylation of the AKT substrate Foxo3a which regulates ERα transcription was decreased in AKT3 knockdown cells. These data suggest that ERα expression is down regulated via AKT3/Foxo3a signaling in ErbB2(+) breast cancer cells. Furthermore, up-regulation of ERα after depletion of AKT3 resulted in a significant increase in Tamoxifen responsiveness of Balb-neuT-derived mammary tumor cells. In addition, Tamoxifen resistant human breast cancer cell lines showed increased AKT3 expression and activity in comparison to Tamoxifen responsive MCF-7 cells. Finally, by AKT isoform specific in vitro kinase assays of human breast cancer samples, AKT3 activity was detected in ErbB2(+) and triple negative tumors but not in ERα(+) breast cancer. Our data indicate that AKT3 regulates the expression of ErbB2, ErbB3 and ERα and demonstrate that down-regulation of activated AKT3 can sensitize ErbB2(+) breast cancer cells for treatment with Tamoxifen. Therefore, AKT3 targeting might be a new promising strategy for therapy of ErbB2(+)/ERα(-) breast cancer and might further increase the responsiveness to an endocrine therapy approach.

EGFR intron-1 CA repeat polymorphism is a predictor of relapse and survival in complete resected only surgically treated esophageal cancer.

Basal transcription regulation of the epidermal growth factor receptor is dependent upon a CA simple sequence repeat polymorphism in the intron-1 (CA-SSR-1). Here, we evaluate the role of CA-SSR-1 in complete resected esophageal cancer (EC) patients without neoadjuvant or adjuvant treatment. Genomic DNA was extracted from peripheral blood leukocytes of 241 patients. To determine the number of the CA repeats in the CA-SSR-1, DNA was amplified by polymerase chain reaction and sequenced. The results were correlated with clinicopathological parameters and clinical outcome. Three genotypes were defined based on cut-off points for short allele (S) with ≤18 and long allele (L) >18 CA repeats. A steadily increasing risk was evident between LL, SL, and SS genotype for larger tumor size, presence of lymph node metastases, and disseminated tumor cells in bone marrow as well as tumor recurrence (P < 0.001, chi-square test). A gradual decrease in disease-free and overall survival (OS) was present among LL, SL, and SS patients (P < 0.001, log-rank test). The different outcomes were also evident in nodal status and histological type adjusted subgroup analyses. CA-SSR-1 was identified as the strongest independent prognosticator of tumor recurrence and OS (P < 0.001, Cox regression analysis). CA-SSR-1 is a strong predictive factor for tumor recurrence and overall survival in patients with complete resected esophageal cancer without neoadjuvant or adjuvant therapy.

Genome-wide investigation of multifocal and unifocal prostate cancer-are they genetically different?

Prostate cancer is widely observed to be biologically heterogeneous. Its heterogeneity is manifested histologically as multifocal prostate cancer, which is observed more frequently than unifocal prostate cancer. The clinical and prognostic significance of either focal cancer type is not fully established. To investigate prostate cancer heterogeneity, the genetic profiles of multifocal and unifocal prostate cancers were compared. Here, we report observations deduced from tumor-tumor comparison of copy number alteration data of both focal categories. Forty-one fresh frozen prostate cancer foci from 14 multifocal prostate cancers and eight unifocal prostate cancers were subjected to copy number variation analysis with the Affymetrix SNP 6.0 microarray tool. With the investigated cases, tumors obtained from a single prostate exhibited different genetic profiles of variable degrees. Further comparison identified no distinct genetic pattern or signatures specific to multifocal or unifocal prostate cancer. Our findings suggest that samples obtained from multiple sites of a single unifocal prostate cancer show as much genetic heterogeneity and variability as separate tumors obtained from a single multifocal prostate cancer.

Frequent genetic alterations in EGFR- and HER2-driven pathways in breast cancer brain metastases.

Current standard systemic therapies for treating breast cancer patients with brain metastases are inefficient. Targeted therapies against human epidermal growth factor receptors are of clinical interest because of their alteration in a subset of breast cancers (BCs). We analyzed copy number, mutation status, and protein expression of epidermal growth factor receptor (EGFR), human epidermal growth factor 2 (HER2), phosphatase and tensin homologue (PTEN), and PI3K catalytic subunit (PIK3CA) in 110 ductal carcinoma in situ, primary tumor, and metastatic BC samples. Alterations in EGFR, HER2, and PTEN, alone or in combination, were found in a significantly larger fraction of breast cancer brain metastases tumor tissue compared with samples from primary tumors with good prognosis, bone relapse, or other distant metastases (all P < 0.05). Primary tumor patients with a subsequent brain relapse showed almost equally high frequencies of especially EGFR and PTEN alteration as the breast cancer brain metastases patients. PIK3CA was not associated with an increased risk of brain metastases. Genetic alterations in both EGFR and PTEN were especially common in triple-negative breast cancer patients and rarely were seen among HER2-positive patients. In conclusion, we identified two independent high-risk primary BC subgroups for developing brain metastases, represented by genetic alterations in either HER2 or EGFR/PTEN-driven pathways. In contrast, none of these pathways was associated with an increased risk of bone metastasis. These findings highlight the importance of both pathways as possible targets in the treatment of brain metastases in breast cancer.

Hybrid cells derived from breast epithelial cell/breast cancer cell fusion events show a differential RAF-AKT crosstalk.

BACKGROUND: The biological phenomenon of cell fusion has been linked to several characteristics of tumour progression, including an enhanced metastatogenic capacity and an enhanced drug resistance of hybrid cells. We demonstrated recently that M13SV1-EGFP-Neo breast epithelial cells exhibiting stem cell characteristics spontaneously fused with MDA-MB-435-Hyg breast cancer cells, thereby giving rise to stable M13MDA435 hybrid cells, which are characterised by a unique gene expression profile and migratory behaviour. Here we investigated the involvement of the PLC-ß/γ1, PI3K/AKT and RAS-RAF-ERK signal transduction cascades in the EGF and SDF-1α induced migration of two M13MDA435 hybrid cell clones in comparison to their parental cells. RESULTS: Analysis of the migratory behaviour by using the three-dimensional collagen matrix migration assay showed that M13SV1-EGFP-Neo cells as well as M13MDA435 hybrid cells, but not the breast cancer cell line, responded to EGF stimulation with an increased locomotory activity. By contrast, SDF-1α solely stimulated the migration of M13SV1-EGFP-Neo cells, whereas the migratory activity of the other cell lines was blocked. Analysis of signal transduction cascades revealed a putative differential RAF-AKT crosstalk in M13MDA435-1 and -3 hybrid cell clones. The PI3K inhibitor Ly294002 effectively blocked the EGF induced migration of M13MDA435-3 hybrid cells, whereas the EGF induced locomotion of M13MDA435-1 hybrid cells was markedly increased. Analysis of RAF-1 S259 phosphorylation, being a major mediator of the negative regulation of RAF-1 by AKT, showed decreased pRAF-1 S259 levels in LY294002 treated M13MDA435-1 hybrid cells. By contrast, pRAF-1 S259 levels remained unaltered in the other cell lines. Inhibition of PI3K/AKT signalling by Ly294002 relieves the AKT mediated phosphorylation of RAF-1, thereby restoring MAPK signalling. CONCLUSIONS: Here we show that hybrid cells could evolve exhibiting a differential active RAF-AKT crosstalk. Because PI3K/AKT signalling has been chosen as a target for anti-cancer therapies our data might point to a possible severe side effect of AKT targeted cancer therapies. Inhibition of PI3K/AKT signalling in RAF-AKT crosstalk positive cancer (hybrid) cells could result in a progression of these cells. Thus, not only the receptor (activation) status, but also the activation of signal transduction molecules should be analysed thoroughly prior to therapy.

Pro-inflammatory wnt5a and anti-inflammatory sFRP5 are differentially regulated by nutritional factors in obese human subjects.

BACKGROUND: Obesity is associated with macrophage infiltration of adipose tissue. These inflammatory cells affect adipocytes not only by classical cytokines but also by the secreted glycopeptide wnt5a. Healthy adipocytes are able to release the wnt5a inhibitor sFRP5. This protective effect, however, was found to be diminished in obesity. The aim of the present study was to examine (1) whether obese human subjects exhibit increased serum concentrations of wnt5a and (2) whether wnt5a and/or sFRP5 serum concentrations in obese subjects can be influenced by caloric restriction. METHODOLOGY: 23 obese human subjects (BMI 44.1 ± 1.1 kg/m(2)) and 12 age- and sex-matched lean controls (BMI 22.3 ± 0.4 kg/m(2)) were included in the study. Obese subjects were treated with a very low-calorie diet (approximately 800 kcal/d) for 12 weeks. Body composition was assessed by impedance analysis, insulin sensitivity was estimated by HOMA-IR and the leptin-to-adiponectin ratio and wnt5a and sFRP5 serum concentrations were measured by ELISA. sFRP5 expression in human adipose tissue biopsies was further determined on protein level by immunohistology. PRINCIPAL FINDINGS: Pro-inflammatory wnt5a was not measurable in any serum sample of lean control subjects. In patients with obesity, however, wnt5a became significantly detectable consistent with low grade inflammation in such subjects. Caloric restriction resulted in a weight loss from 131.9 ± 4.0 to 112.3 ± 3.2 kg in the obese patients group. This was accompanied by a significant decrease of HOMA-IR and leptin-to-adiponectin ratio, indicating improved insulin sensitivity. Interestingly, these metabolic improvements were associated with a significant increase in serum concentrations of the anti-inflammatory factor and wnt5a-inhibitor sFRP5. CONCLUSIONS/SIGNIFICANCE: Obesity is associated with elevated serum levels of pro-inflammatory wnt5a in humans. Furthermore, caloric restriction beneficially affects serum concentrations of anti-inflammatory sFRP5 in such subjects. These findings suggest a novel regulatory system in low grade inflammation in obesity, which can be influenced by nutritional therapy.