Breast Cancer Associated Fibroblasts Promote MCF-7 Invasion in vitro by Secretion of HGF

This study was aimed to explore the influence of breast cancer associated fibroblasts (CAFs) in migration and invasion of breast cancer cell line MCF-7,and investigate whether hepatocyte growth factor (HGF) is involved in this process.Primary breast CAFs and their corresponding normal breast fi-broblasts (NFs) were obtained by collagenase digestion.On the basis of the co-culture,the migration and invasion capacity of MCF-7 cells was compared between CAFs and NFs by Transwell.The differ-ence in the HGF expression between them was detected by ELISA.The secretion of HGF was knocked down by using RNA interference technology in CAFs.Then the changes of migration and invasion ca-pacity of MCF-7 cells were investigated by Transwell.Eventually,we isolated high-purity CAFs and NFs,and the CAFs had a stronger ability in promoting MCF-7 migration and invasion than the NFs.ELISA results demonstrated that CAFs secreted higher HGF,and the capacity of MCF-7 migration and invasion was declined after knocking down the secretion of HGF in CAFs by RNA interference.It is suggested that CAFs can promote MCF-7 migration and invasion through HGF in vitro.

Cancer-associated fibroblasts in hepatocellular carcinoma

The hepatic stellate cells in the liver are stimulated sustainably by chronic injury of the hepatocytes, activating myofibroblasts, which produce abundant collagen. Myofibroblasts are the major source of extracellular proteins during fibrogenesis, and may directly, or secreted products, contribute to carcinogenesis and tumor progression. Cancer-associated fibroblasts(CAFs) are one of the components of the tumor microenvironment that promote the proliferation and invasion of cancer cells by secreting various growth factors and cytokines. CAFs crosstalk with cancer cells stimulates tumor progression by creating a favorable microenvironment for progression, invasion, and metastasis through the epithelial-mesenchymal transition. Basic studies on CAFs have advanced, and the role of CAFs in tumors has been elucidated. In particular, for hepatocellular carcinoma, carcinogenesis from cirrhosis is a known fact, and participation of CAFs in carcinogenesis is supported. In this review, we discuss the current literature on the role of CAFs and CAF-related signaling in carcinogenesis, crosstalk with cancer cells, immunosuppressive effects, angiogenesis, therapeutic targets, and resistance to chemotherapy. The role of CAFs is important in cancer initiation and progression. CAF-targeted therapy may be effective for suppression not only of fibrosis but also cancer progression.

Tumor–stromal cross-talk modulating the therapeutic response in pancreatic cancer

Background: Pancreatic ductal adenocarcinoma(PDAC) is a highly malignant solid tumor with a dismal prognosis. The stroma component makes up to 90% of the tumor mass and is thought to be one of the main reasons for the tumor’s high chemoresistance. Cancer associated fibroblasts(CAFs) have previously been identified to be the key stromal players. This is the first time we provide detailed in vitro experiments investigating tumor–stromal interactions when exposed to three well-known chemotherapeutic agents. Methods: Monocultures, indirect and direct co-cultures of two PDAC cell lines(AsPC and Panc-1) and six primary patients derived CAFs were treated with gemcitabine, nab-paclitaxel and the γ-secretaseinhibitor(GSI) DAPT. The cell viability of each component was measured with XTT. Finally, IL-6 concentrations of the supernatants were analyzed. Results: On the contrary to PDAC cell lines, CAF monocultures hardly responded to any treatment which suggested that stroma(CAFs) itself is more resistant to standard chemo-treatments than the epithelial cancer cells. Moreover, only a weak chemotherapeutic response was observed in direct co-cultures of cancer cells with CAFs. A change in the morphology of direct co-cultures was accompanied with the chemoresistance. CAFs were observed to build cage-like structures around agglomerates of tumor cells. High levels of IL-6 were also associated with a reduced response to therapy. Indirect co-cultures make the tumor–stromal interaction more complex. Conclusions: CAFs are highly chemoresistant. Direct cell–cell contact and high levels of IL-6 correlate with a high chemoresistance.

Pancreatic cancer stroma:understanding biology leads to new therapeutic strategies

Pancreatic ductal adenocarcinoma(PDA)is among the deadliest cancers in the United States and in the world.Late diagnosis,early metastasis and lack of effective therapy are among the reasons why only 6%of patients diagnosed with PDA survive past 5 years.Despite development of targeted therapy against other cancers,little progression has been made in the treatment of PDA.Therefore,there is an urgent need for the development of new treatments.However,in order to proceed with treatments,the complicated biology of PDA needs to be understood first.Interestingly,majority of the tumor volume is not made of malignant epithelial cells but of stroma.In recent years,it has become evident that there is an important interaction between the stromal compartment and the less prevalent malignant cells,leading to cancer progression.The stroma not only serves as a growth promoting source of signals but it is also a physical barrier to drug delivery.Understanding the tumor-stroma signaling leading to development of desmoplastic reaction and tumor progression can lead to the development of therapies to decrease stromal activity and improve drug delivery.In this review,we focus on how the current understanding of biology of the pancreatic tumor microenvironment can be translated into the development of targeted therapy.

Next-generation sequencing traces human induced pluripotent stem cell lines clonally generated from heterogeneous cancer tissue

AIM To investigate genotype variation among induced pluripotent stem cell(iPSC) lines that were clonally generated from heterogeneous colon cancer tissues using next-generation sequencing. METHODS Human iPSC lines were clonally established by selecting independent single colonies expanded from heterogeneous primary cells of S-shaped colon cancer tissues by retroviral gene transfer(OCT3/4, SOX2, and KLF4). The ten iPSC lines, their starting cancer tissues, and the matched adjacent non-cancerous tissues were analyzed using nextgeneration sequencing and bioinformatics analysis using the human reference genome hg19. Non-synonymous single-nucleotide variants(SNVs)(missense, nonsense,and read-through) were identified within the target region of 612 genes related to cancer and the human kinome. All SNVs were annotated using dbS NP135, CCDS, RefSeq, GENCODE, and 1000 Genomes. The SNVs of the iPSC lines were compared with the genotypes of the cancerous and non-cancerous tissues. The putative genotypes were validated using allelic depth and genotype quality. For final confirmation, mutated genotypes were manually curated using the Integrative Genomics Viewer. RESULTS In eight of the ten iPSC lines, one or two non-synonymous SNVs in EIF2AK2, TTN, ULK4, TSSK1 B, FLT4, STK19, STK31, TRRAP, WNK1, PLK1 or PIK3R5 were identified as novel SNVs and were not identical to the genotypes found in the cancer and non-cancerous tissues. This result suggests that the SNVs were de novo or pre-existing mutations that originated from minor populations, such as multifocal pre-cancer(stem) cells or pre-metastatic cancer cells from multiple, different clonal evolutions, present within the heterogeneous cancer tissue. The genotypes of all ten iPSC lines were different from the mutated ERBB2 and MKNK2 genotypes of the cancer tissues and were identical to those of the noncancerous tissues and that found in the human reference genome hg19. Furthermore, two of the ten iPSC lines did not have any confirmed mutated genotypes, despite being derived from cancerous tissue. These results suggest that the traceability and preference of the starting single cells being derived from pre-cancer(stem) cells, stroma cells such as cancer-associated fibroblasts, and immune cells that co-existed in the tissues along with the mature cancer cells.CONCLUSION The genotypes of iPSC lines derived from heterogeneous cancer tissues can provide information on the type of starting cell that the iPSC line was generated from.

Exposure of benzo[a]pyrene induces HCC exosome-circular RNA to activate lung fibroblasts and trigger organotropic metastasis

Background:Benzo[a]pyrene(B[a]P),a carcinogen pollutant produced by combustion processes,is present in the western diet with grilled meats.Chronic exposure of B[a]P in hepatocellular carcinoma(HCC)cells promotes metastasis rather than primary proliferation,implying an unknown mechanism of B[a]P-induced malignancy.Given that exosomes carry bioactive molecules to distant sites,we investigated whether and how exosomes mediate cancer-stroma communications for a toxicologically associated microenvironment.Method:Exosomes were isolated from B[a]P stimulated BEL7404 HCC cells(7404-100Bap Exo)at an environmental relevant dose(100 nmol/L).Lung preeducation animal model was prepared via injection of exosomes and cytokines.The inflammatory genes of educated lungs were evaluated using quantitative reverse transcription PCR array.HCC LM3 cells transfected with firefly luciferase were next injected to monitor tumor burdens and organotropic metastasis.Profile of B[a]P-exposed exosomes were determined by ceRNA microarray.Interactions between circular RNA(circRNA)and microRNAs(miRNAs)were detected using RNA pull-down in target lung fibroblasts.Fluorescence in situ hybridization and RNA immunoprecipitation assay was used to evaluate the“on-off”interaction of circRNA-miRNA pairs.We further developed an adenoassociated virus inhalation model to examine mRNA expression specific in lung,thereby exploring the mRNA targets of B[a]P induced circRNA-miRNA cascade.Results:Lung fibroblasts exert activation phenotypes,including focal adhesion and motility were altered by 7404-100Bap Exo.In the exosome-educated in vivo model,fibrosis factors and pro-inflammatory molecules of are up-regulated when injected with exosomes.Compared to non-exposed 7404 cells,circ_0011496 was up-regulated following B[a]P treatment and wasmainly packaged into 7404-100Bap Exo.Exosomal circ_0011496 were delivered and competitively bound to miR-486-5p in recipient fibroblasts.The down-regulation of miR-486-5p converted fibroblast to cancer-associated fibroblast via regulating the downstream of Twinfilin-1(TWF1)and matrix metalloproteinase-9(MMP9)cascade.Additionally,increased TWF1,specifically in exosomal circ_0011496 educated lungs,could promote cancer-stroma crosstalk via activating vascular endothelial growth factor(VEGF).These modulated fibroblasts promoted endothelial cells angiogenesis and recruited primary HCC cells invasion,as a consequence of a pre-metastatic niche formation.Conclusion:We demonstrated that B[a]P-induced tumor exosomes can deliver circ_0011496 to activate miR-486-5p/TWF1/MMP9 cascade in the lung fibroblasts,generating a feedback loop that promoted HCC metastasis.

Microenvironment in the pathogenesis of gastric cancer metastasis

Tumor tissues contain cancer cells,other cellular and non-cellular comp onen ts.Tumor microe nvir onments consist of cancer cells and various types of stromal cells,can cer associated fibroblasts,bone marrow-derived cells,en dothelial cells,and hematopoietic cells,mainly tumor-associated macrophages and tumor-infiltrating lymphocytes.Increasing recent evidence has demonstrated that alteration of tumor microenvironments is deeply implicated in tumor progression and metastasis in gastric can cer(GC)patients.Recent in vestigati ons have provided in sights into the molecular mecha ni sms of the interaction between tumor cells and tumor microenvironments.Interactions between cancer cells and their microe nvir onment with cytok ines and microRNA in extracellular vesicles,such as the exosome,can have a substa ntial impact on tumor characteristics.Alterati ons in the tumor microe nvironment may play a crucial role in facilitating the progression of tumor cells and metastasis,as well as the activation of cell signaling pathways,which are associated with GC cell proliferati on and in vasi on by genetic or epigenetic alterations.In this review,significant molecular in sights into the tumor microenvironment,which consist of cancer associated fibroblasts,bone marrow-derived cells,tumor-associated macrophages and tumor-infiltrating lymphocytes;the interactions between cancer cells and their microenvironment;and the clinical impacts of alterations of GC microenvironments will be discussed.

Liquid biopsy:expanding the frontier of circulating biomarker discovery and validation in breast cancer

Liquid biopsies represent an attractive,minimally-invasive alternative to surgical sampling or complex imaging of breast cancer and breast cancer metastasis.Here we present a summary of the major biomarker components often evaluated in liquid biopsy samples from patients with breast cancer,including circulating tumor cells,circulating cell-free tumor DNA,and cancer-associated plasma proteins.We discuss recent advancements in methods of detection and use of these biomarkers in breast cancer.Finally,we highlight some of our own recent contributions to breast cancer liquid biopsy,including the identification and characterization of circulating Cancer Associated Fibroblasts.