Cancer‐associated fibroblast promote transmigration through endothelial brain cells in three‐dimensional in vitro models

Brain metastases are associated with high morbidity as well as with poor prognosis and survival in breast cancer patients. Despite its clinical importance, metastasis of breast cancer cells through the blood‐brain barrier (BBB) is poorly understood. The objective of our study was to investigate whether cancer‐associated fibroblasts (CAFs) play crucial roles in breast cancer brain metastasis. Using a cell adhesion assays, in vitro BBB permeability and transmigration assays and soft agar colony formation assays, we investigated the physical roles of CAFs in breast cancer brain metastasis. We also performed immunofluorescence, flow cytometric analysis, Droplet Digital PCR and Simon? Simple Western System to confirm changes in expression levels. We established two novel three‐dimensional (3D) culture systems using a perpendicular slide chamber and applying 3D embedded culture method to reflect brain metastasis conditions. With a newly developed device, CAFs was proven to promote cell adhesion to human brain microvascular endothelial cells, in vitro BBB permeability and transmigration and colony formation of breast cancer cells. Furthermore, CAFs enhanced the invasive migration of breast cancer cells in two kinds of 3D cultures. These 3D models also reliably recapitulate the initial steps of BBB transmigration, micro‐metastasis and colonization. Expression of integrin α5β1 and αvβ3, c‐MET and α2,6‐siayltransferase was increased in breast cancer cells that migrated through the BBB. In conclusion, based on our in vitro BBB and co‐culture models, our data suggest that CAFs may play a role in breast cancer brain metastasis.     

Multiple uses of basement membrane-like matrix (BME/Matrigel) in vitro and in vivo with cancer cells

Significant advances in our understanding of cancer cell behavior, growth, and metastasis have been facilitated by studies using a basement membrane-like extracellular matrix extract, also known as Matrigel. The basement membrane is a thin extracellular matrix that is found in normal tissues and contacts epithelial and endothelial cells, smooth muscle, fat, Schwann cells, etc. It is composed of mainly laminin-111, collagen IV, heparan sulfate proteoglycan, entactin/nidogen, and various growth factors (fibroblast growth factor, transforming growth factor beta, epidermal growth factor, etc.). Most tumors of epithelial origin produce significant amounts of basement membrane matrix and interact with it particularly during metastasis. Cancer cells metastasize via degradation of the vessel basement membrane matrix to extravasate into the blood stream and colonize distant sites. This review will focus on the interaction of cancer cells and cancer stem cells with the basement membrane-like matrix and the various uses of this interaction to accelerate tumor growth in vivo and to develop in vitro assays for invasion, morphology, and dormancy. Such assays and methods have advanced our understanding of the process of cancer progression, the genes and pathways that are involved, the potential of various therapeutic agents, the effects of neighboring cells, and the role of stem cells.     

Cancer‐associated mesenchymal stroma fosters the stemness of osteosarcoma cells in response to intratumoral acidosis via NF‐κB activation

The role of mesenchymal stem cells (MSC) in osteosarcoma (OS), the most common primary tumor of bone, has not been extensively elucidated. We have recently shown that OS is characterized by interstitial acidosis, a microenvironmental condition that is similar to a wound setting, in which mesenchymal reactive cells are activated to release mitogenic and chemotactic factors. We therefore intended to test the hypothesis that, in OS, acid‐activated MSC influence tumor cell behavior. Conditioned media or co‐culture with normal MSC previously incubated with short‐term acidosis (pH 6.8 for 10 hr, H⁺‐MSC) enhanced OS clonogenicity and invasion. This effect was mediated by NF‐κB pathway activation. In fact, deep‐sequencing analysis, confirmed by Real‐Time PCR and ELISA, demonstrated that H⁺‐MSC differentially induced a tissue remodeling phenotype with increased expression of RelA, RelB and NF‐κB1, and downstream, of CSF2/GM‐CSF, CSF3/G‐CSF and BMP2 colony‐promoting factors, and of chemokines (CCL5, CXCL5 and CXCL1), and cytokines (IL6 and IL8), with an increased expression of CXCR4. An increased expression of IL6 and IL8 were found only in normal stromal cells, but not in OS cells, and this was confirmed in tumor‐associated stromal cells isolated from OS tissue. Finally, H⁺‐MSC conditioned medium differentially promoted OS stemness (sarcosphere number, stem‐associated gene expression), and chemoresistance also via IL6 secretion. Our data support the hypothesis that the acidic OS microenvironment is a key factor for MSC activation, in turn promoting the secretion of paracrine factors that influence tumor behavior, a mechanism that holds the potential for future therapeutic interventions aimed to target OS.     

Flubendazole elicits anti‐metastatic effects in triple‐negative breast cancer via STAT3 inhibition

Tumor metastasis remains the cause of 90% of cancer‐related deaths. Cancer stem cells (CSC) are thought to be responsible for the aggressive and metastatic nature of triple‐negative breast cancers (TNBC), and new therapeutic strategies are being devised to target them. Flubendazole (FLU) is a widely used anthelmintic agent that also exhibits anticancer activity in several cancer types. The aim of this study was to characterize the mechanism of action of FLU on breast cancer stem cell (BCSC)‐like properties and metastasis in TNBC. FLU treatment caused a significant induction of apoptosis, accompanied by G2/M phase accumulation, caspase‐3/‐7 activation and the dysregulation of STAT3 activation in TNBC cells. The latter phenomenon was associated with impairment of cancer stem‐like traits, concomitant with a reduction in the CD24^low/CD44^high, CD24^high/CD49f^high subpopulation, ALDH1 activity and mammosphere formation. The BCSC‐enriched populations exhibited enhanced metastasis with higher STAT3 activation, while FLU administration inhibited tumor growth, angiogenesis and lung and liver metastasis, coinciding with decreased MMP‐2 and MMP‐9 levels in circulating blood. FLU kills not only rapid proliferating tumor cells but also effectively eradicates BCSC‐like cells in vitro and in vivo. Our findings warrant further investigation of FLU as a treatment for metastatic TNBC.     

3D培养在神经胶质瘤研究中的应用

传统的肿瘤研究依赖于肿瘤细胞系构建肿瘤模型,并在细胞基础上测定肿瘤细胞的耐药性等,但在临床实验中大多数肿瘤药物以失败告终,其中最主要的原因是细胞系不能模拟肿瘤细胞在人体内微环境的特性,3D培养技术在肿瘤研究中的应用愈加广泛。本文主要从3D培养在神经胶质瘤研究中的应用进行综述。     

Use of a novel 3D culture model to elucidate the role of mesothelial cells, fibroblasts and extra-cellular matrices on adhesion and invasion of ovarian cancer cells to the omentum

The omentum is a major site of ovarian cancer metastasis. Our goal was to establish a three-dimensional (3D) model of the key components of the omental microenvironment (mesothelial cells, fibroblasts and extracellular matrices) to study ovarian cancer cell adhesion and invasion. The 3D model comprised of primary human fibroblasts extracted from normal human omentum, mixed with ECM and covered by a layer of primary human mesothelial cells, also from normal human omentum. After addition of ovarian cancer cells, the histological appearance of the 3D culture mimicked microscopic metastases to the omentum from patients with ovarian cancer. When ovarian cancer cells, SKOV3ip.1 and HeyA8, were applied to the 3D omental culture, 60% and 68% of all cells attached, respectively, but only 18% and 25% were able to invade. Ovarian cancer cells preferentially adhered to and invaded collagen I, followed by binding to collagen IV, fibronectin, vitronectin, laminin 10 and 1. Omental mesothelial cells significantly inhibited ovarian cancer cell adhesion and invasion, while omental fibroblasts induced adhesion and invasion. This effect is clearly mediated by direct cell-cell contact, since conditioned medium from mesothelial cells or fibroblasts has a minimal, or no, effect on ovarian cancer cell adhesion and invasion. In summary, we have established a 3D model to study the early steps of ovarian cancer metastasis to the human omentum, and found that omental mesothelial cells inhibit, while omental fibroblasts and the ECM enhance, the attachment and invasion of ovarian cancer cells.     

Prognostic value of cytosolyc cathepsin D content in resectable gastric cancer

BACKGROUND AND AIMS: Cathepsin D (Cath-D) is an aspartyl protease involved in protein catabolism and tissue remodelling. In the present article, we evaluate the tumor content of Cath-D in resectable gastric carcinomas and its relation with clinical and pathological parameters, as well as its prognostic significance. METHOD: This prospective study included a series of 60 patients with primary gastric adenocarcinoma, who first underwent a complete surgical resection of their tumors and then were evaluated for disease recurrence and survival status during a mean follow-up period of 41.5 months. Cath D was measured in cytosolic samples using an immune-radiometric assay which determined the total amount of Cath-D (52K, 48K, and 34K). RESULTS: The tumor content of Cath-D ranged from 4 to 247 pmol/mg protein and from 6.4 to 97.7 pmol/mg protein in adjacent non-neoplastic mucosa samples. Cytosolic Cath-D levels were significantly higher in neoplastic tissues (P < 0.001). Statistical analysis also demonstrated that younger patients showed lower Cath-D tumor levels than older ones. Likewise, patients with lower tumor levels of Cath-D had better survival than those with intermediate or high Cath-D tumor content (P = 0.002). This finding showed an independent prognostic value on survival (P = 0.02). CONCLUSIONS: The present study demonstrates the presence of higher Cath-D content in gastric carcinomas than in adjacent non-neoplastic mucosa, and that high intratumor Cath-D levels identify a subgroup of resectable gastric cancer patients with a high probability of relapse as well as worse survival.     

Identification of novel candidate biomarkers of epithelial ovarian cancer by profiling the secretomes of three‐dimensional genetic models of ovarian carcinogenesis

Epithelial ovarian cancer (EOC) is still considered the most lethal gynecological malignancy and improved early detection of ovarian cancer is crucial to improving patient prognoses. To address this need, we tested whether candidate EOC biomarkers can be identified using three‐dimensional (3D) in vitro models. We quantified changes in the abundance of secreted proteins in a 3D genetic model of early‐stage EOC, generated by expressing CMYC and KRAS^G12V in TERT‐immortalized normal ovarian epithelial cells. Cellular proteins were labeled in live cells using stable isotopic amino acid analogues, and secreted proteins identified and quantified using liquid chromatography‐tandem mass spectrometry. Thirty‐seven and 55 proteins were differentially expressed by CMYC and CMYC+KRAS^G12V expressing cells respectively (p < 0.05; >2‐fold). We evaluated expression of the top candidate biomarkers in ～210 primary EOCs: CHI3L1 and FKBP4 are both expressed by >96% of primary EOCs, and FASN and API5 are expressed by 86 and 75% of cases. High expression of CHI3L1 and FKBP4 was associated with worse patient survival (p = 0.042 and p = 0.002, respectively). Expression of LGALS3BP was positively associated with recurrence (p = 0.0001) and suboptimal debulking (p = 0.018) suggesting that these proteins may be novel prognostic biomarkers. Furthermore, within early stage tumours (I/II), high expression of API5, CHI3L1 and FASN was associated with high tumour grade (p = 3 × 10^?4, p = 0.016, p = 0.010, respectively). We show in vitro cell biology models of early‐stage cancer development can be used to identify novel candidate biomarkers for disease, and report the identification of proteins that represent novel potential candidate diagnostic and prognostic biomarkers for this highly lethal disease.     

Down‐regulation of KIAA1199/CEMIP by miR‐216a suppresses tumor invasion and metastasis in colorectal cancer

Colorectal cancer is one of the major causes of death from cancer. Metastasis is the leading cause of treatment failure, in which cancer stem cells and circulating tumor cells play crucial roles. Identifying the involved metastatic biomarkers and clarifying the regulation mechanisms are of great importance for targeting tumor metastasis. In the current research, we discovered that KIAA1199, a cell‐migration inducing protein, showed higher expression in CD44+ cancer cells from metastatic compared with the paired primary tissues, and was upregulated in colorectal cancer and positively correlated with numbers and mesenchymal phenotype of circulating tumor cells, and predicted shorter progress‐free survival. Moreover, we indicated that down‐regulation of KIAA1199 suppressed migration and invasion of colorectal cancer cells in vitro, and inhibited metastasis in vivo. Furthermore, we demonstrated that KIAA1199 was one of the direct and functional targets of miR‐216a, and miR‐216a overexpression led to decreased migration and invasion of colorectal cancer cells in vitro, and inhibited metastasis in vivo. Collectively, KIAA1199 plays a critical role in maintaining an aggressive phenotype of tumor cells, and suppression of KIAA1199‐related motilities of tumor cells contributes to reduced tumor metastasis in colorectal cancer.     

Side population of pancreatic cancer cells predominates in TGF‐β‐mediated epithelial to mesenchymal transition and invasion

We report here side population (SP) cells, a cancer stem cell enriched fraction from pancreatic cancer cell line, have enormous superior potential of the epithelial to mesenchymal transition (EMT), invasion, and metastasis. In an isolated SP cell culture, the cells rapidly expressed and up‐regulated E‐cadherin, an epithelial phenotypic marker, and the cells formed tightly contacted cell cluster, which is a representative epithelial phenotypic appearance. When the SP cells were incubated in the presence of TGF‐β, SP cells changed their shape into mesenchymal‐like appearance including spindle shaped assembly. This alteration was associated with significant reduction of E‐cadherin expression level. TGF‐β induced EMT‐associated gene alteration such as reduction of E‐cadherin mRNA and induction of Snail mRNA and matrixmetalloproteinase (MMP)‐2 mRNA. Finally, SP cells exerted notable matrigel invasion activity in response to TGF‐β treatment, whereas MP cells did not respond to TGF‐β‐mediated invasion. In conclusion, these results suggest that SP cells from pancreatic cancer cell line possess superior potentials of phenotypic switch, i.e., EMT/MET, micro‐invasion, and in vivo metastasis, as compared to MP cells. Because micro‐invasion and metastasis are key mechanisms of cancer malignant potential, SP cells would be the attractive target for preventing cancer progression. © 2008 UICC     

Inhibition of invasion and metastasis by glypican-3 in a syngeneic breast cancer model

Glypican-3 (GPC3), a proteoglycan bound to the cell membrane through a GPI anchor, is widely expressed in the embryo but down regulated in most adult tissues, with some exceptions as mammary cells. GPC3 is involved in the regulation of cell proliferation and survival in specific cell types. LM3, a murine mammary tumor cell line unable to express GPC3, was stably transfected with the rat GPC3 gene to analyze its role in tumor progression. Upon injection into syngeneic BALB/c mice LM3-GPC3 clones showed less local invasiveness and developed fewer spontaneous and experimental lung metastasis than controls. GPC3-expressing cells were more sensitive to apoptosis induced by serum depletion, exhibited a delay in the first steps of spreading and were less motile than controls. On the other hand, LM3-GPC3 cells were significantly more adherent to FN than control ones. We observed that GPC3 transfectants presented a higher expression of E-cadherin and -catenin, molecules whose down regulation has been associated with tumor progression. Exogenous TGF- increased MMP-9 activity in both control and GPC3-expressing cells, but did not modulate MMP-2. Contrarily, GPC3 expression prevented the increase of MMP-2 activity induced by IGF-II. Our results suggest that GPC3 has a protective role against mammary cancer progression.     

HPV‐avertable cancer risks in India: A pooled analysis of 9 observational studies

Recent advances in cancer stem cell biology have shown that cancer stem‐like cells with epithelial–mesenchymal transition (EMT) phenotypes are more aggressive and cause relapse; however, absence of a specific marker to isolate these EMT stem‐like cells hampers research in this direction. Cell surface markers have been identified for isolating cancer stem‐like cells, but none has been identified for isolating cancer stem‐like cells with EMT phenotype. Recently, we discovered that Vimentin, an intracellular EMT tumor cell marker, is present on the surface of colon metastatic tumor nodules in the liver. In our study, we examined the potential of targeting cell surface Vimentin (CSV) to isolate stem‐like cancer cells with EMT phenotype, by using a specific CSV‐binding antibody, 84‐1. Using this antibody, we purified the CSV‐positive, CD133‐negative (csVim⁺CD133⁻) cell population from primary liver tumor cell suspensions and characterized for stem cell properties. The results of sphere assays and staining for the stem cell markers Sox2 and Oct4A demonstrated that csVim⁺CD133⁻ cells have stem‐like properties similar to csVim⁻CD133⁺ population. Our investigation further revealed that the csVim⁺CD133⁻ cells had EMT phenotypes, as evidenced by the presence of Twist and Slug in the nucleus, the absence of EpCAM on the cell surface and basal level of expression of epithelial marker E‐cadherin. The csVimentin‐negative CD133‐positive stem cells do not have any EMT phenotypes. csVim⁺CD133⁻ cells exhibited more aggressively metastatic in livers than csVim⁻CD133⁺ cells. Our findings indicate that csVim⁺CD133⁻ cells are promising targets for treatment and prevention of metastatic hepatocellular carcinoma.     

Super-extended (D3) lymphadenectomy in advanced gastric cancer

Purpose

To analyze our experience with D3 lymphadenectomy in the treatment of advanced GC with specific reference to post-operative morbidity and mortality, incidence of para-aortic node (PAN) metastases, and long-term prognosis.

Methods

Short- and long-term results of D3 lymphadenectomy were analyzed in 286 patients with advanced GC.

Results

PAN metastases were demonstrated in 37 patients. PAN involvement was significantly higher in upper third tumours (29%) compared to middle and lower third (7%; P < 0.001). Eighty patients developed post-operative complications, being pulmonary disorders (6%), abdominal abscesses (4.5%) and pancreatic fistulas (3%) the most frequently observed. In-hospital mortality was 2%. Overall 5-year survival rate for R0 pT2-4 patients was 52%. When considering survival in relation to nodal involvement, both pN3 and non-regional lymph node metastases (M1a) patients showed a chance of long-term survival: 5-year survival was 31% for pN3 and 17% for M1a cases. Furthermore, the 5-year survival rate was remarkably high (about 60%) even in pN2 and pN3 subsets when no serosal invasion (pT2) was demonstrated.

Conclusions

D3 lymphadenectomy could be further explored in specialized centers for curative surgery of advanced GC, especially for upper third tumours, providing that an acceptable morbidity and no increase in mortality can be offered.     

卵巢癌肿瘤微环境的三维细胞培养模型研究进展

卵巢癌(Ovarian cancer,OC)是一种具有侵袭性和致命性的癌症。越来越多的研究表明,肿瘤微环境(Tumor microenvironment,TME)通过各种机制参与促进卵巢癌发生、发展、免疫抑制和炎性反应。TME包括肿瘤血管和淋巴管,以及肿瘤细胞、间质细胞、免疫细胞和细胞外基质(ECM)等。本文结合近年来的文献报道,综述了目前常用的卵巢癌TME三维细胞培养模型,以及总结了许多不包含原始基质细胞的三维模型,旨在总结和寻找卵巢癌治疗的新途径和新方法。     

Caspase‐3 regulates the migration,invasion and metastasis of colon cancer cells

Caspase‐3 (CASP3) is a major mediator of apoptosis activated during cellular exposure to cytotoxic drugs, radiotherapy or immunotherapy. It is often used as a marker for efficacy of cancer therapy. However, recent reports indicate that caspase‐3 has also non‐apoptotic roles such as promotion of tumor relapse and tumor angiogenesis. Therefore, the roles of caspase‐3 in tumor progression remain to be defined clearly. In our study, we established caspase‐3 knockout (KO) colon cancer cell lines by use of the CRISPR technology. In vitro, caspase‐3 knockout HCT116 cells were significantly less clonogenic in soft agar assays. They were also significantly less invasive and more sensitive to radiation and mitomycin C than control cells. In vivo, CASP3KO cells formed tumors at rates similar to control cells but were significantly more sensitive to radiotherapy. They were also less prone to pulmonary metastasis when inoculated either subcutaneously or intravenously. At the mechanistic level, caspase‐3 gene knockout appeared to cause reduced EMT phenotypes when compared to parental HCT116 cells. Indeed, they showed significantly increased E‐cadherin expression, reduced N‐cadherin, Snail, Slug and ZEB1 expression than control cells. Therefore, therapeutic targeting of caspase‐3 may not only increase the sensitivity of cancer cell to chemotherapy and radiotherapy, but also inhibit cancer cell invasion and metastasis.