There is overwhelming evidence that in vitro three-dimensional tumor cell cultures more accurately reflect the complex in vivo microenvironment than simple two-dimensional cell monolayers, not least ...with respect to gene expression profiles, signaling pathway activity and drug sensitivity. However, most currently available three-dimensional techniques are time consuming and/or lack reproducibility; thus standardized and rapid protocols are urgently needed.
To address this requirement, we have developed a versatile toolkit of reproducible three-dimensional tumor spheroid models for dynamic, automated, quantitative imaging and analysis that are compatible with routine high-throughput preclinical studies. Not only do these microplate methods measure three-dimensional tumor growth, but they have also been significantly enhanced to facilitate a range of functional assays exemplifying additional key hallmarks of cancer, namely cell motility and matrix invasion. Moreover, mutual tissue invasion and angiogenesis is accommodated by coculturing tumor spheroids with murine embryoid bodies within which angiogenic differentiation occurs. Highly malignant human tumor cells were selected to exemplify therapeutic effects of three specific molecularly-targeted agents: PI-103 (phosphatidylinositol-3-kinase (PI3K)-mammalian target of rapamycin (mTOR) inhibitor), 17-N-allylamino-17-demethoxygeldanamycin (17-AAG) (heat shock protein 90 (HSP90) inhibitor) and CCT130234 (in-house phospholipase C (PLC)γ inhibitor). Fully automated analysis using a Celigo cytometer was validated for tumor spheroid growth and invasion against standard image analysis techniques, with excellent reproducibility and significantly increased throughput. In addition, we discovered key differential sensitivities to targeted agents between two-dimensional and three-dimensional cultures, and also demonstrated enhanced potency of some agents against cell migration/invasion compared with proliferation, suggesting their preferential utility in metastatic disease.
We have established and validated a suite of highly reproducible tumor microplate three-dimensional functional assays to enhance the biological relevance of early preclinical cancer studies. We believe these assays will increase the translational predictive value of in vitro drug evaluation studies and reduce the need for in vivo studies by more effective triaging of compounds.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Epithelial-mesenchymal transition (EMT) is defined by the loss of epithelial characteristics and the acquisition of a mesenchymal phenotype. In carcinoma cells, EMT can be associated with increased ...aggressiveness, and invasive and metastatic potential. To assess the occurrence of EMT in human breast tumors, we conducted a tissue microarray-based immunohistochemical study in 479 invasive breast carcinomas and 12 carcinosarcomas using 28 different markers. Unsupervised hierarchical clustering of the tumors and statistical analysis showed that up-regulation of EMT markers (vimentin, smooth-muscle-actin, N-cadherin, and cadherin-11) and overexpression of proteins involved in extracellular matrix remodeling and invasion (SPARC, laminin, and fascin), together with reduction of characteristic epithelial markers (E-cadherin and cytokeratins), preferentially occur in breast tumors with the "basal-like phenotype." Moreover, most breast carcinosarcomas also had a basal-like phenotype and showed expression of mesenchymal markers in their sarcomatous and epithelial components. To assess whether basal-like cells have intrinsic phenotypic plasticity for mesenchymal transition, we performed in vitro studies with the MCF10A cell line. In response to low cell density, MCF10A cells suffer spontaneous morphologic and phenotypic EMT-like changes, including cytoskeleton reorganization, vimentin and Slug up-regulation, cadherin switching, and diffuse cytosolic relocalization of the catenins. Moreover, these phenotypic changes are associated with modifications in the global genetic differentiation program characteristic of the EMT process. In summary, our data indicate that in breast tumors, EMT likely occurs within a specific genetic context, the basal phenotype, and suggests that this proclivity to mesenchymal transition may be related to the high aggressiveness and the characteristic metastatic spread of these tumors.
Macrophage polarization is relevant for tumor biology. M2 polarized macrophages favor tumor growth and survival, while M1 macrophages support tumor destruction and antigen presentation. Markers ...identifying M1/M2 polarization are a subject of debate. We conducted a systematic review and meta-analysis to investigate the association of proposed macrophage markers with prognosis across epithelial tumors and melanoma. The Medline search engine was used and 195 articles were recovered for full review. Only articles which measured markers using immunohistochemistry or immunofluorescence and had overall survival (OS) as the primary endpoint were included. One hundred and thirteen articles were finally accepted for analysis. CD68 was associated with worse survival across tumors (hazard ratio (HR) = 1.24, 95% CI = 1.11-1.37). Tumor anatomical location influenced this association. Colorectal tumors showed an inverse association between CD68 and OS in contrast to the rest of cancer types (HR = 0.56 vs. 1.34). The approach taken to measure CD68 had an impact on prognosis; when macrophages were measured at the tumor invasion front prognosis was more favorable than when they were measured intratumorally (HR = 0.94 vs. 1.4). CD163, CD204, and CD206 showed a robust association with worse OS (HR = 1.63, 1.95, 1.65, respectively). Tumors arising in the lung and the liver showed a weaker association between CD163 and OS as compared with other locations (β = -0.5401 for the lung and -0.5940 for the liver compared with other anatomical locations). The counting strategy also had an impact on CD163 association with OS, with hot-spot counting having higher HRs compared with averaging macrophage counts across spots or absolute cell counting (β = -0.4678). In conclusion, proposed M2 markers are associated with worse survival across epithelial tumors and melanoma. The anatomical origin of tumors influences this association. The compartment where the macrophages were scored and counting strategy influenced the association with OS of CD68 and CD163, respectively.
Head and neck squamous cell carcinoma (HNSCC) represents 6% of all cancers. The overall 5-year survival rate for patients with this type of cancer is among the lowest of the major cancer types and ...has not improved dramatically during the last decade. The pathological staging, in particular the nodal stage, is the most important factor in HNSCC. The lack of progress in head and neck oncology emphasizes the importance of molecular genetic studies to define alterations that may correlate with tumor behavior. The molecular alterations observed in HNSCC are mainly due to oncogene activation and tumor suppressor gene inactivation, leading to deregulation of cell proliferation. These alterations include gene amplification and overexpression of oncogenes such as ras, myc, EGFR and cyclin D1, and mutations and deletions leading to p16 and TP53 tumor suppressor genes inactivation. This article reviews the molecular changes commonly observed in HNSCC. The biological function of these markers and the potential clinical application are discussed. Advances in the understanding of the molecular basis of HNSCC will help in the identification of new molecular markers that could be used for a more accurate diagnosis and assessment of prognosis and may open the way for novel approaches to treatment and prevention.
A recent study conducted in mice reported that liver-specific knockout of tumor suppressor Pten augments nuclear factor (erythroid-derived 2)-like 2 (NRF2) transcriptional activity. Here, we further ...investigated how phosphatase and tensin homolog deleted on chromosome 10 (PTEN) controls NRF2 and the relevance of this pathway in human carcin ogenesis.
Drug and genetic targeting to PTEN and phosphoproteomics approaches indicated that PTEN leads to glycogen synthase kinase-3 (GSK-3)-mediated phosphorylation of NRF2 at residues Ser(335) and Ser(338) and subsequent beta-transducin repeat containing protein (β-TrCP)-dependent but Kelch-like ECH-associated protein 1 (KEAP1)-independent degradation. Rescue experiments in PTEN-deficient cells and xerographs in athymic mice indicated that loss of PTEN leads to increased NRF2 signature which provides a proliferating and tumorigenic advantage. Tissue microarrays from endometrioid carcinomas showed that 80% of PTEN-negative tumors expressed high levels of NRF2 or its target heme oxygenase-1 (HO-1).
These results uncover a new mechanism of oncogenic activation of NRF2 by loss of its negative regulation by PTEN/GSK-3/β-TrCP that may be relevant to a large number of tumors, including endometrioid carcinomas.
Increased activity of NRF2 due to loss of PTEN is instrumental in human carcinogenesis and represents a novel therapeutic target.
Purpose: Basal-like phenotype tumors are frequently found among BRCA1 germ-line mutated breast carcinomas. They are biologically aggressive and have a tendency towards visceral metastasis when
...untreated. Nevertheless, it has been suggested that they respond to chemotherapy better than other types of tumors. Fascin
expression has been associated with lung metastasis in breast cancer. The aim of this study was to determine whether basal-like
phenotype and fascin were related in both sporadic and familial tumors and with prognosis in node-negative sporadic breast
cancers.
Experimental design: 230 nonfamilial and 28 hereditary node-negative invasive breast carcinomas were immunohistochemically analyzed using tissue
microarrays. Tumors that were estrogen receptor/HER2 negative and cytokeratin 5/6 and/or epidermal growth factor receptor
positive were considered to have a basal-like phenotype.
Results: A basal-like phenotype was found in 11.9% of sporadic cancers. Among patients not receiving adjuvant chemotherapy, a basal-like
phenotype was associated with poor prognosis ( P = 0.001, log-rank test) whereas no such association was found in patients receiving it. Tumors with a basal-like phenotype
showed local recurrence (17.4%) or visceral metastasis (13%) but not bone metastasis ( P = 0.001). Fascin expression was observed in 25.1% of sporadic invasive breast carcinomas and was associated with the basal-like
phenotype, but not with prognosis or recurrence pattern. Fascin was expressed in 83.3% and 16.7% BRCA1 - and BRCA2 -associated carcinomas, respectively ( P = 0.048).
Conclusions: Basal-like tumors had a tendency towards visceral metastasis and their prognosis was dependent on the use of postoperative
chemotherapy. Although fascin expression was associated with the basal-like phenotype, it was not associated with their metastatic
behavior. Fascin expression is frequent in BRCA1 -associated tumors.
Ovarian cancer remains one of the leading causes of cancer deaths. Thus, new biomarkers predictive of response to the standard paclitaxel–carboplatin treatment are needed to improve chemotherapy ...strategies. MicroRNAs have the potential to modify drug outcomes. Based on this, we have demonstrated in this study that patients with a high expression of the miR-200 family show low levels of β-tubulin class III in ovarian carcinoma. In addition, we have established the clinical relevance of these microRNAs for ovarian cancer patients' treatment response and survival. In a well-characterized series of 72 ovarian carcinomas, the expressions of miR-141, miR-200a, miR-200b, miR-200c, and miR-429 were quantified by quantitative reverse transcription-PCR, and the protein content of β-tubulin isotypes I, II, and III was determined by immunohistochemistry. The relationship between these microRNAs, β-tubulin expression, response to paclitaxel-based treatment, progression-free survival (PFS) and overall survival was determined. While isotype I had constant high levels, protein expression of β-tubulins II and III was mutually exclusive. Low tumoral miR-200 expression was significantly associated with high β-tubulin III protein content (P values range, 0.047–<0.0001), and patients without complete response (CR) had lower miR-200c levels than patients with CR (hazard ratio (HR)=1.43, 95% confidence interval (CI)=1.02–1.99, P=0.037, multivariate analysis). Additionally, low miR-200 family expression had a trend toward poor PFS (HR>2.0, P values 0.051, 0.054, and 0.079 for miR-200c, miR-141, and miR-429 respectively, multivariate analysis). In conclusion, miR-200 family members affect the final β-tubulin III protein content of ovarian carcinomas. Furthermore, these microRNAs might constitute the biomarkers of response to paclitaxel-based treatments and relapse/progression of advanced stage ovarian carcinoma patients.
Approximately 20–30% of endometrial carcinomas (EC) are characterized by mismatch repair (MMR) deficiency (dMMR) or microsatellite instability (MSI), and their testing has become part of the routine ...diagnosis. The aim of this study was to establish and compare the MMR status using various approaches. Immunohistochemistry (IHC), PCR-based MSI, and the detection of defects in the four key MMR genes (MLH1, PMS2, MSH2, and MSH6) via methylation-specific multiplex ligation-dependent probe amplification (MLPA) and targeted next-generation sequencing (NGS) were performed. MSH3 expression was also evaluated. A set of 126 early-stage EC samples were analyzed, 53.2% of which were dMMR and 46.8% of which were proficient MMR (pMMR) as determined using IHC, whereas 69.3% were classified as microsatellite stable, while 8.8% and 21.9% were classified MSI-low (MSI-L) and MSI-high (MSI-H), respectively. In total, 44.3% of the samples showed genetic or epigenetic alterations in one or more genes; MLH1 promoter methylation was the most common event. Although acceptable concordance was observed, there were overall discrepancies between the three testing approaches, mainly associated with the dMMR group. IHC had a better correlation with MMR genomic status than the MSI status determined using PCR. Further studies are needed to establish solid conclusions regarding the best MMR assessment technique for EC.
Lysyl oxidase-like 2 (Loxl2) interacts with and stabilizes Snai1 transcription factor, promoting epithelial-mesenchymal transition. Either Loxl2 or Snai1 knock-down blocks tumor growth and induces ...differentiation, but the specific role of each factor in tumor progression is still unknown. Comparison of the gene expression profiles of the squamous cell carcinoma cell line HaCa4 after knocking-down Loxl2 or Snai1 revealed that a subset of epidermal differentiation genes was specifically up-regulated in Loxl2-silenced cells. In agreement, although both Loxl2- and Snai1-knockdown cells showed reduced in vivo invasion, only Loxl2-silenced cells exhibited a skin-like epidermal differentiation program. In addition, we show that expression of Loxl2 and Snai1 correlates with malignant progression in a two-stage mouse skin carcinogenesis model. Furthermore, we found that increased expression of both LOXL2 and SNAI1 correlates with local recurrence in a cohort of 256 human laryngeal squamous cell carcinomas. We describe for the first time that high levels of LOXL2 are associated with decreased overall and disease-free survival in laryngeal squamous cell carcinomas, lung squamous cell carcinoma, and lymph node-negative (N(0)) breast adenocarcinomas. Altogether, our results show that LOXL2 can be used as a new poor prognosis indicator in human squamous cell carcinomas promoting malignant transformation by both SNAI1-dependent and SNAI1-independent pathways.
Deregulation of Src kinases is associated with cancer. We previously showed that SrcDN conditional expression in MCF7 cells reduces tumorigenesis and causes tumor regression in mice. However, it ...remained unclear whether SrcDN affected breast cancer stem cell functionality or it reduced tumor mass. Here, we address this question by isolating an enriched population of Breast Cancer Stem Cells (BCSCs) from MCF7 cells with inducible expression of SrcDN. Induction of SrcDN inhibited self-renewal, and stem-cell marker expression (Nanog, Oct3-4, ALDH1, CD44). Quantitative proteomic analyses of mammospheres from MCF7-Tet-On-SrcDN cells (data are available via ProteomeXchange with identifier PXD017789, project DOI: 10.6019/PXD017789) and subsequent GSEA showed that SrcDN expression inhibited glycolysis. Indeed, induction of SrcDN inhibited expression and activity of hexokinase, pyruvate kinase and lactate dehydrogenase, resulting in diminished glucose consumption and lactate production, which restricted Warburg effect. Thus, c-Src functionality is important for breast cancer stem cell maintenance and renewal, and stem cell transcription factor expression, effects linked to glucose metabolism reduction.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
PDF
