Cancer-associated adipocyte-derived G-CSF promotes breast cancer malignancy via Stat3 signaling

Adipocyte is the most predominant cell type in the tumor microenvironment of breast cancer and plays a pivotal role in cancer progression,yet the underlying mechanisms and functional mediators remain elusive.We isolated primary preadipocytes from mammary fat pads of human breast cancer patients and generated mature adipocytes and cancer-associated adipocytes(CAAs)in vitro.The CAAs exhibited significantly different gene expression profiles as assessed by transcriptome sequencing.One of the highly expressed genes in CAAs is granulocyte colony-stimulating factor(G-CSF).Treatment with recombinant human G-CSF protein or stable expression of human G-CSF in triple-negative breast cancer(TNBC)cell lines enhanced epithelial–mesenchymal transition,migration,and invasion of cancer cells,by activating Stat3.Accordantly,targeting G-CSF/Stat3 signaling with G-CSF-neutralizing antibody,a chemical inhibitor,or siRNAs for Stat3 could all abrogate CAA-or G-CSF-induced migration and invasion of breast cancer cells.The pro-invasive genes MMP2 and MMP9 were identified as target genes of G-CSF in TNBC cells.Furthermore,in human breast cancer tissues,elevated G-CSF expression in adipocytes is well correlated with activated Stat3 signal in cancer cells.Together,our results suggest a novel strategy to intervene with invasive breast cancers by targeting CAA-derived G-CSF.

Lacticaseibacillus paracasei K56 inhibits lipid accumulation in adipocytes by promoting lipolysis

Probiotics crosstalk immunity to improve host glycolipid metabolism,which is a new strategy for obesity.This study aimed to explore the functions of Lacticaseibacillus paracasei K56(K56),in regulating the lipid metabolism of adipocytes and its immune regulation mechanisms.We co-cultured RAW264.7 macrophages with K56,and the K56-stimulated RAW264.7-conditioned medium(K56-CM)was collected and treated with 3T3-L1 pre-adipocytes.The expression of lipid metabolism-related markers of adipocytes,and the content of cytokines in CMs were detected.The results demonstrated that K56-CM promoted the expression of peroxisome proliferator-activated receptor-γ(PPAR-γ),CCAAT/enhancer binding proteinα(C/EBPα),and other adipogenesis-related markers,which resulted in the upregulation of lipolysis markers,such as hormone-sensitive lipase(HSL),adipose triglyceride lipase(ATGL).The activation of lipolysis enhanced the expression of fatty acidβ-oxidation-related and mitochondrial biogenesis-related markers and reduced lipid accumulation in adipocytes.The glycolipid metabolism pattern of K56 may be due to its immunomodulatory characteristics,which stimulated macrophages to secrete fewer TNF-α,thereby promoting the expression of lipolysis-related markers,and TNF-αsynergized with lipase to promote lipolysis.It has not been reported that L.paracasei modulated lipid metabolism via the lipolysis pathway,which suggested that K56 may regulate glycolipid metabolism of the host by maintaining immune homeostasis.

A cell transcriptomic profile p ovides insights into adipocytes of porcine mammary gland across development

Background Studying the composition and developmental mechanisms in mammary gland is crucial for healthy growth of newborns. The mammary gland is inherently heterogeneous, and its physiological function dependents on the gene expression of multiple cell types. Most studies focused on epithelial cells, disregarding the role of neighboring adipocytes.Results Here, we constructed the largest transcriptomic dataset of porcine mammary gland cells thus far. The dataset captured 126,829 high-quality nuclei from physiological mammary glands across five developmental stages(d 90 of gestation, G90;d 0 after lactation, L0;d 20 after lactation, L20;2 d post natural involution, PI2;7 d post natural involution, PI7). Seven cell types were identified, including epithelial cells, adipocytes, endothelial cells, fibroblasts cells, immune cells, myoepithelial cells and precursor cells. Our data indicate that mammary glands at different developmental stages have distinct phenotypic and transcriptional signatures. During late gestation(G90), the differentiation and proliferation of adipocytes were inhibited. Meanwhile, partly epithelial cells were completely differentiated. Pseudo-time analysis showed that epithelial cells undergo three stages to achieve lactation, including cellular differentiation, hormone sensing, and metabolic activation. During lactation(L0 and L20), adipocytes area accounts for less than 0.5% of mammary glands. To maintain their own survival, the adipocyte exhibited a poorly differentiated state and a proliferative capacity. Epithelial cells initiate lactation upon hormonal stimulation. After fulfilling lactation mission, their undergo physiological death under high intensity lactation. Interestingly, the physiological dead cells seem to be actively cleared by immune cells via CCL21-ACKR4 pathway. This biological process may be an important mechanism for maintaining homeostasis of the mammary gland. During natural involution(PI2 and PI7), epithelial cell populations dedifferentiate into mesenchymal stem cells to maintain the lactation potential of mammary glands for the next lactation cycle.Conclusion The molecular mechanisms of dedifferentiation, proliferation and redifferentiation of adipocytes and epithelial cells were revealed from late pregnancy to natural involution. This cell transcriptomic profile constitutes an essential reference for future studies in the development and remodeling of the mammary gland at different stages.

CRABP2 regulates infiltration of cancer-associated fibroblasts and immune response in melanoma

Finding biomarkers for immunotherapy is an urgent issue in cancer treatment.Cellular retinoic acid-binding protein 2(CRABP2)is a controversial factor in the occurrence and development of human tumors.However,there is limited research on the relationship between CRABP2 and immunotherapy response.This study found that negative correlations of CRABP2 and immune checkpoint markers(PD-1,PD-L1,and CTLA-4)were observed in breast invasive carcinoma(BRCA),skin cutaneous melanoma(SKCM),stomach adenocarcinoma(STAD)and testicular germ cell tumors(TGCT).In particular,in SKCM patients who were treated with PD-1 inhibitors,high levels of CRABP2 predicted poor prognosis.Additionally,CRABP2 expression was elevated in cancer-associated fibroblasts(CAFs)at the single-cell level.The expression of CRABP2 was positively correlated with markers of CAFs,such as MFAP5,PDPN,ITGA11,PDGFRα/βand THY1 in SKCM.To validate the tumor-promoting effect of CRABP2 in vivo,SKCM xenograft mice models with CRABP2 overexpression have been constructed.These models showed an increase in tumor weight and volume.Enrichment analysis indicated that CRABP2 may be involved in immunerelated pathways of SKCM,such as extracellular matrix(ECM)receptor interaction and epithelial-mesenchymal transition(EMT).The study suggests that CRABP2 may regulate immunotherapy in SKCM patients by influencing infiltration of CAFs.In conclusion,this study provides new insights into the role of CRABP2 in immunotherapy response.The findings suggest that CRABP2 may be a promising biomarker for PD-1 inhibitors in SKCM patients.Further research is needed to confirm these findings and to explore the clinical implications of CRABP2 in immunotherapy.

Identification of porcine fast/slow myogenic exosomes and their regulatory effects on lipid accumulation in intramuscular adipocytes

Background Pork quality is affected by the type of muscle fibers, which is closely related to meat color, tenderness and juiciness. Exosomes are tiny vesicles with a diameter of approximately 30–150 nm that are secreted by cells and taken up by recipient cells to mediate communication. Exosome-mediated muscle-fat tissue crosstalk is a newly discovered mechanism that may have an important effect on intramuscular fat deposition and with that on meat quality. Various of adipose tissue-derived exosomes have been discovered and identified, but the identification and function of muscle exosomes, especially porcine fast/slow myotube exosomes, remain unclear. Here, we first isolated and identified exosomes secreted from porcine extensor digitorum longus(EDL) and soleus(SOL), which represent fast and slow muscle, respectively, and further explored their effects on lipid accumulation in longissimus dorsi adipocytes.Results Porcine SOL-derived exosomes(SOL-EXO) and EDL-derived exosomes(EDL-EXO) were first identified and their average particle sizes were approximately 84 nm with double-membrane disc-shapes as observed via transmission electron microscopy and scanning electron microscopy. Moreover, the intramuscular fat content of the SOL was greater than that of the EDL at 180 days of age, because SOL intramuscular adipocytes had a stronger lipid-accumulating capacity than those of the EDL. Raman spectral analysis revealed that SOL-EXO protein content was much greater than that of EDL-EXO. Proteomic sequencing identified 72 proteins that were significantly differentially expressed between SOL-EXO and EDL-EXO, 31 of which were downregulated and 41 of which were upregulated in SOL-EXO.Conclusions Our findings suggest that muscle-fat tissue interactions occur partly via SOL-EXO promoting adipogenic activity of intramuscular adipocytes.

Impact of STAT-signaling pathway on cancer-associated fibroblasts in colorectal cancer and its role in immunosuppression

Colorectal cancer(CRC)remains one of the most commonly diagnosed and deadliest types of cancer worldwide.CRC displays a desmoplastic reaction(DR)that has been inversely associated with poor prognosis;less DR is associated with a better prognosis.This reaction generates excessive connective tissue,in which cancer-associated fibroblasts(CAFs)are critical cells that form a part of the tumor microenvironment.CAFs are directly involved in tumorigenesis through different mechanisms.However,their role in immunosuppression in CRC is not well understood,and the precise role of signal transducers and activators of transcription(STATs)in mediating CAF activity in CRC remains unclear.Among the myriad chemical and biological factors that affect CAFs,different cytokines mediate their function by activating STAT signaling pathways.Thus,the harmful effects of CAFs in favoring tumor growth and invasion may be modulated using STAT inhibitors.Here,we analyze the impact of different STATs on CAF activity and their immunoregulatory role.

The flavonoid glycoside vaccarin inhibits adipogenesis and stimulates lipolysis via Hedgehog signaling in 3T3-L1 adipocytes

Vaccarin,a flavonoid glycoside isolated from Vaccaria segetalis,is non-toxic to 3T3-L1 cells up to concentrations of 200μM.Accordingly,we investigated the effects of this natural product on adipogenesis and lipolysis in 3T3-L1 adipocytes.Our results revealed that vaccarin significantly inhibited lipid accumulation by suppressing the adipogenesis-related transcription factors peroxisome proliferator-activated receptorγ(PPARγ)and the CCAAT/enhancer-binding proteinα(C/EBPα).Specifically,lipid accumulation decreased by up to 27.7±2.7%when 3T3-L1 adipocytes were treated with a 10μM concentration of vaccarin.Mechanistic studies showed that the compound inhibited adipogenesis through activation of the Hedgehog(Hh)signaling pathway and so restoring Smo and Gli1 expression at an early stage of differentiation.In mature 3T3-L1 cells,vaccarin significantly increased the secretion of glycerol into the surrounding medium and thus indicating that it accelerated the degradation of triglycerides.In addition,vaccarin,was shown to enhance lipolysis through stimulation of the transcription levels of lipoprotein lipase,monoglycerides lipase,adipose triacylglyceride lipase,hormone-sensitive lipase and adipose differentiated-related protein.All told,vaccarin suppressed lipid accumulation and enhanced lipolysis during adipocyte differentiation by restoring Hh signaling.As such,it is a phytochemical capable of halting adipocyte hyperplasia and,thereby,ameliorating the effects of obesity.

Distinction of white,beige and brown adipocytes derived from mesenchymal stem cells

Adipose tissue is a major metabolic organ, and it has been traditionally classified as either white adipose tissue(WAT) or brown adipose tissue(BAT). WAT and BAT are characterized by different anatomical locations, morphological structures, functions, and regulations. WAT and BAT are both involved in energy balance. WAT is mainly involved in the storage and mobilization of energy in the form of triglycerides, whereas BAT specializes in dissipating energy as heat during cold- or diet-induced thermogenesis. Recently, brownlike adipocytes were discovered in WAT. These brownlike adipocytes that appear in WAT are called beige or brite adipocytes. Interestingly, these beige/brite cells resemble white fat cells in the basal state, but they respond to thermogenic stimuli with increased levels of thermogenic genes and increased respiration rates. In addition, beige/brite cells have a gene expressionpattern distinct from that of either white or brown fat cells. The current epidemic of obesity has increased the interest in studying adipocyte formation(adipogenesis), especially in beige/brite cells. This review summarizes the developmental process of adipose tissues that originate from the mesenchymal stem cells and the features of these three different types of adipocytes.

Curcumin,a Potential Inhibitor of Up-regulation of TNF-alpha and IL-6 Induced by Palmitate in 3T3-L1 Adipocytes through NF-kappaB and JNK Pathway

Objective To investigate the attenuating effect of curcumin, an anti-inflammatory compound derived from dietary spice turmeric （Curcuma longa） on the pro-inflammatory insulin-resistant state in 3T3-L1 adipocytes. Methods Glucose uptake rate was determined with the [3H] 2-deoxyglucose uptake method. Expressions of tumor necrosis factor-α （TNF-α） and interleukin-6 （IL-6） were measured by quantitative RT-PCR analysis and ELISA. Nuclear transcription factor kappaB p65 （NF-r,B p65） and mitogen-activated protein kinase （MAPKs） were detected by Western blot assay. Results The basal glucose uptake was not altered, and curcumin increased the insulin-stimulated glucose uptake in 3T3-L1 cells. Curcumin suppressed the transcription and secretion of TNF-α and IL-6 induced by palmitate in a concentration-dependent manner. Palmitate induced nuclear translocation of NF-kB. The activities of Jun NH2-terminal kinase ONK）, extracellular signal-regulated kinasel/2 （ERKI/2） and p38MAPK decreased in the presence of curcumin. Moreover, pretreatment with SP600125 （inhibitor of JNK） instead of PD98059 or SB203580 （inhibitor of ERKI/2 or p38MAPK, respectively） decreased the up-regulation of TNF-α induced by palmitate. Conelusion Curcumin reverses palmitate-induced insulin resistance state in 3T3-L1 adipocytes through the NF-kB and JNK pathway.

Role of tissue microenvironment resident adipocytes in colon cancer

Colorectal cancer(CRC) is a multifactorial disease characterized by several genetic and epigenetic alterations occurring in epithelial cells. It is increasingly recognized that tumour progression is also regulated by tumour microenvironment(TME). The bidirectional cross-talk between tumour resident adipocytes and cancer cells within TME has been proposed as active contributor to carcinogenesis. Tumour resident adipocytes exhibit an activated phenotype characterized by increased secretion of pro-tumorigenic factors(angiogenic/inflammatory/immune) which contribute to cancer cell proliferation, invasion, neoangiogenesis, evasion of immune surveillance and therapy resistance. Furthermore, adipocytes represent a fuel rich source for increasing energy demand of rapidly proliferating tumour cells. Interestingly, a relationship between obesity and molecular variants in CRC has recently been identified. Whether adipose tissue promotes cancer progression in subsets of molecular phenotypes or whether local tissue adipocytes are involved in inactivation of tumour suppressor genes and/or activation of oncogenes still needs to be explored. This editorial highlights the major findings related to crosstalk between adipocytes and colon cancer cells and how local paracrine interactions may promote cancer progression. Furthermore, we provide future strategies in studying colonic TME which could provide insights in bidirectional cross-talk mechanisms between adipocytes and colonic epithelial cells. This could enable to decipher critical signalling pathways of both early colonic carcinogenesis and cancer progression.

Anti-diabetic effects of Caulerpa lentillifera:stimulation of insulin secretion in pancreatic β-cells and enhancement of glucose uptake in adipocytes

Objective:To evaluate anti-diabetic effect of Caulrpa kntillifera(C.lentillifera).Methods:The inhibitory effect of C.lentillifera extract on dipeptidyl peptidase-IV and a-glucosidase enzyme was measured in a cell free system.Then,interleukin-1βand interferon-γinduced cell death and insulin secretion were measured in rat insulinoma(RIN)cells by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay and ELISA kit,respectively.Glucose uptake and glucose transporter expression were measured by fluorometry and western blotting,using 3T3-Ll adipocytes.Results:C.lentillifera extract significantly decreased dipeptidyl peptidase-IV and a-glucosidase enzyme activities,and effectively inhibited cell death and iNOS expression in interleukin-1βand interfcron-γinduced RIK cells.Furthermore,C.lntillifera extract significantly enhanced insulin secretion in RTN cells and glucose transporter expression and glucose uptake in 3T3-L1adipocytes.Conclusions:Thus,our results suggest that C.lentillifera could be used as a potential antidiabetic agenl.

Role of cancer-associated fibroblasts in invasion and metastasis of gastric cancer

Cancer-associated fibroblasts(CAFs) are important components of various types of tumors,including gastric cancer(GC).During tumorigenesis and progression,CAFs play critical roles in tumor invasion and metastasis via a series of functions including extracellular matrix deposition,angiogenesis,metabolism reprogramming and chemoresistance.However,the mechanism of the interaction between gastric cancer cells and CAFs remains largely unknown.Micro RNAs(mi RNAs) are a class of non-coding small RNA molecules,and their expression in CAFs not only regulates the expression of a number of target genes but also plays an essential role in the communication between tumor cells and CAFs.In this review,we provide an overview of recent studies on CAF mi RNAs in GC and the relevant signaling pathways in gastrointestinal tumors.Focusing the attention on these signaling pathways may help us better understand their role in tumor invasion and metastasis and identify new molecular targets for therapeutic strategies.

Characterization and Differentiation into Adipocytes and Myocytes of Porcine Bone Marrow Mesenchymal Stem Cells

Bone marrow mesenchymal stem cells （BMSCs） could differentiate into various cell types including adipocytes and myocytes, which had important scientific significance not only in the field of tissue regeneration, but also in the field of agricultural science. In an attempt to exhibit the characterization and differentiation into adipocytes and myocytes of porcine BMSCs, we isolated and purified porcine BMSCs by red blood cell lysis method and percoll gradient centrifugation. The purified cells presented a stretched fibroblast-like phenotype when adhered to the culture plate. The results of flow cytometry analysis and immunofluorescence staining demonstrated that the isolated cells were positive for mesenchymal surface markers CD29, CD44 and negative for hematopoietic markers CD45 and the adhesion molecules CD31. Cells were induced to differentiate into adipocytes with adipogenic medium containing insulin, dexamethasone, oleate and octanoate. Oil Red O staining demonstrated that the porcine BMSCs successfully differentiated to adipocytes. Moreover, the findings of real-time PCR and Western blotting indicated that the induced cells expressed adipogenic marker genes （PPAR-y, C/EBP-c~, perilipin, aP2） mRNA or proteins （PPAR-3,, perilipin, aP2）. On the other hand, porcine BMSCs were induced into myoctyes with myogenic medium supplemented with 5-azacytidine, basic fibroblast growth factor, chick embryo extract and horse serum. Morphological observation by hochest 33342 staining showed that the induced cells presented as multi-nucleus muscular tube structure. And myogenic marker genes （Myf5, desmin） mRNA or proteins （MyfS, MyoD, myogenin, desmin） were found in the induced cells. In addition, the results of immunofluorescence staining revealed that myogenic marker （Myf5, MyoD, myogenin, desmin, S-MyHC） proteins was positive in the induced cells. Above all, these results suggested that the isolated porcine BMSCs were not only consistent with the characterization of mesenchymal stem cells, but also exhibited the multipotential capacity to form adipocytes and myocytes, which provided the basis to investigate the regulation mechanism involved in the selective differentiation of porcine BMSCs.

Adipocyte activation of cancer stem cell signaling in breast cancer

Signaling within the tumor microenvironment has a critical role in cancer initiation and progression. Adipocytes, one of the major components of the breast microenvironment,have been shown to provide pro-tumorigenic signals that promote cancer cell proliferation and invasiveness in vitro and tumorigenicity in vivo. Adipocyte secreted factors such as leptin and interleukin-6(IL-6) have a paracrine effect on breast cancer cells. In adipocyte-adjacent breast cancer cells, the leptin and IL-6 signaling pathways activate janus kinase 2/signal transducer and activatorof transcription 5, promoting the epithelial-mesenchymal transition, and upregulating stemness regulators such as Notch, Wnt and the Sex determining region Y-box 2/octamer binding transcription factor 4/Nanog signaling axis. In this review we will summarize the major signaling pathways that regulate cancer stem cells in breast cancer and describe the effects that adipocyte secreted IL-6 and leptin have on breast cancer stem cell signaling. Finally we will introduce a new potential treatment paradigm of inhibiting the adipocyte-breast cancer cell signaling via targeting the IL-6 or leptin pathways.

Monascus pilosus-fermented black soybean inhibits lipid accumulation in adipocytes and in high-fat diet-induced obese mice

Objective:To explore the anti-obesity effects and the mechanism of action of Monascus pilosus(M.pilosus)-fermented black soybean(MFBS)extracts(MFBSE)and MFBS powders(MFBSP)in adipocytes and high-fat diet(HFD)-induced obese mice,respectively.Methods:Black soybean was fermented with M.pilosus,and the main constituents in MFBS were analyzed by HPLC analysis.In vitro,MFBSE were examined for anti-adipogenic effects using Oil-Red O staining.In vivo,mice were fed a normal-fat diet(NFD)control,HFD control or HFD containing 1 g/kg MFBSP for 12 weeks,and then body weight gain and tissues weight measured.Real-time PCR and western blot assay were used to determine the mechanism of anti-adipogenic effects.Results:MFBSE inhibited lipid accumulation in 3T3-L1 adipocytes without exerting cell cytotoxicity.MFBSP treatment in HFD-fed mice significantly decreased the body weight gain compared with the HFD control mice.MFBSE and MFBSP treatment resulted in significantly lower mRNA levels of adipogenesis-related genes,such as peroxisome proliferator-activated receptorγ(PPARγ),fatty acid-binding protein 4(FABP4),and fatty acid synthase(FAS),in adipocytes and in white adipose tissue(WAT)of HFD-induced obese mice.Conclusions:These results suggest that the anti-obesity effects of MFBS are elicited by regulating the expression of adipogenesis-related genes in adipocytes and WAT of HFDinduced obese mice.

Astragaloside Ⅳ inhibits pathological functions of gastric cancer-associated fibroblasts

AIM To investigate the inhibitory effect of astragaloside IV on the pathological functions of cancer-associated fibroblasts,and to explore the underlying mechanism.METHODS Paired gastric normal fibroblast(GNF) and gastric cancer-associated fibroblast(GCAF) cultures were established from resected tissues. GCAFs were treated with vehicle control or different concentrations of astragaloside Ⅳ. Conditioned media were prepared from GNFs,GCAFs,control-treated GCAFs,and astragaloside Ⅳ-treated GCAFs,and used to culture BGC-823 human gastric cancer cells. Proliferation,migration and invasion capacities of BGC-823 cells were determined by MTT,wound healing,and Transwell invasion assays,respectively. The action mechanism of astragaloside Ⅳ was investigated by detecting the expression of micro RNAs and the expression and secretion of the oncogenic factor,macrophage colonystimulating factor(M-CSF),and the tumor suppressive factor,tissue inhibitor of metalloproteinase 2(TIMP2),in different groups of GCAFs. The expression of the oncogenic pluripotency factors SOX2 and NANOG in BGC-823 cells cultured with different conditioned media was also examined.RESULTS GCAFs displayed higher capacities to induce BGC-823 cell proliferation,migration,and invasion than GNFs(P < 0.01). Astragaloside Ⅳ treatment strongly inhibited the proliferation-,migration-and invasion-promoting capacities of GCAFs(P < 0.05 for 10 μmol/L,P < 0.01 for 20 μmol/L and 40 μmol/L). Compared with GNFs,GCAFs expressed a lower level of micro RNA-214(P < 0.01) and a higher level of micro RNA-301 a(P < 0.01). Astragaloside Ⅳ treatment significantly upregulated micro RNA-214 expression(P < 0.01) and down-regulated micro RNA-301 a expression(P < 0.01) in GCAFs. Reestablishing the micro RNA expression balance subsequently suppressed M-CSF production(P < 0.01) and secretion(P < 0.05),and elevated TIMP2 production(P < 0.01) and secretion(P < 0.05). Consequently,the ability of GCAFs to increase SOX2 and NANOG expression in BGC-823 cells was abolished by astragaloside Ⅳ.CONCLUSION Astragaloside Ⅳ can inhibit the pathological functions of GCAFs by correcting their dysregulation of micro RNA expression,and it is promisingly a potent therapeutic agent regulating tumor microenvironment.

Key players in pancreatic cancer-stroma interaction: cancer-associated fibroblasts, endothelial and inflammatory cells

Pancreatic cancer(PC) is the most aggressive type of common cancers, and in 2014, nearly 40000 patients died from the disease in the United States. Pancreatic ductal adenocarcinoma, which accounts for the majority of PC cases, is characterized by an intense stromal desmoplastic reaction surrounding the cancer cells. Cancer-associated fibroblasts(CAFs) are the main effector cells in the desmoplastic reaction, and pancreatic stellate cells are the most important source of CAFs. However, other important components of the PC stroma are inflammatory cells and endothelial cells. The aim of this review is to describe the complex interplay between PC cells and the cellular and noncellular components of the tumour stroma. Published data have indicated that the desmoplastic stroma protects PC cells against chemotherapy and radiation therapy and that it might promote the proliferation and migration of PC cells. However, in animal studies, experimental depletion of the desmoplastic stroma and CAFs has led to more aggressive cancers. Hence, the precise role of the tumour stroma in PC remains to be elucidated. However, it is likely that a contextdependent therapeutic modification, rather than pure depletion, of the PC stroma holds potential for the development of new treatment strategies for PC patients.

Roles of adipocyte derived hormone adiponectin and resistin in insulin resistance of type 2 diabetes

AIM： To detect plasma levels of new adipocyte derived hormone adiponectin and resistin in type 2 diabetes patients and to explore their potential roles in insulin resistance in type 2 diabetes. METHODS： According to the body mass index （BMI）, 60 type 2 diabetes patients were divided into two groups, one group was non-obese diabetes patients with BMI 〈 25Kg/M^2 （30 cases） and the other group was obese diabetes patients with BMI 〉25Kg/M^2 （30 cases）. There were 28 healthy persons in the control group. EUSA technique was employed to determine the plasma adiponectin and resistin concentrations. The fasting blood glucose, insulin and blood lipid were detected respectively by electrocheminescence immunoassay and immunoturbidimetric assay. Insulin resistance index and insulin sensitive index were calculated by the homeostasis model assessment （HOMO）. RESULTS： The levels of plasma adiponectin were decreased significantly in diabetes group compared to that in control group （non-obese： 8.58±0.86, obese： 6.22±1.34 vs 10.53±1.47 P〈0.05）; moreover, adiponectin concentration in obese diabetes group was significantly decreased compared to that in non-obese diabetes group （6.22±1.34 vs 8.58±0.86, P〈 0.05）. The levels of plasma resistin were increased significantly in diabetes group compared to that in control group （obese： 18.64 ± 4.65, non-obese： 24.05±9.07 vs 14.16±5.25, P〈0.05,P〈0.05）; furthermore, the levels of resistin in obese diabetes group were increased significantly compared to that in non-obese diabetes group （P〈 0.05）. Plasma adiponectin was correlated negatively with BMI, blood glucose, insulin resistance index and triglyceride （respectively, r=-0.55, P〈0.01; r=-0.51, P〈0.05; r=-0.52, P〈 0.05： r=-0.39, P〈 0.05）, while it was positively correlated with insulin sensitive index （r=0.45, P〈0.05）. Conversely, plasma resistin correlated positively with BMI, blood glucose, triglyceride and insulin resistance index （respectively, r=0.40, P〈 0.05; r= 0.52, P〈0.05; r= 0.46, P〈 0.01; r= 0.27, P〈 0.05）, and negatively correlated with insulin sensitive index （r=-0.32, P〈 0.05）. CONCLUSION： Plasma adiponectin and resistin are associatecl with the disorder of metabolism of glucose and lipid in diabetes. The relationship between these hormone and insulin sensitivity suggests that they may take part in the development of insulin resistance of type 2 diabetes.

The RNA-binding protein Musashi2 governs osteoblast-adipocyte lineage commitment by suppressing PPARγsignaling

Osteoporosis caused by aging is characterized by reduced bone mass and accumulated adipocytes in the bone marrow cavity. How the balance between osteoblastogenesis and adipogenesis from bone marrow mesenchymal stem cells(BMSCs) is lost upon aging is still unclear. Here, we found that the RNA-binding protein Musashi2(Msi2) regulates BMSC lineage commitment. Msi2 is commonly enriched in stem cells and tumor cells. We found that its expression was downregulated during adipogenic differentiation and upregulated during osteogenic differentiation of BMSCs. Msi2 knockout mice exhibited decreased bone mass with substantial accumulation of marrow adipocytes, similar to aging-induced osteoporosis. Depletion of Msi2 in BMSCs led to increased adipocyte commitment. Transcriptional profiling analysis revealed that Msi2 deficiency led to increased PPARγ signaling.RNA-interacting protein immunoprecipitation assays demonstrated that Msi2 could inhibit the translation of the key adipogenic factor Cebpα, thereby inhibiting PPAR signaling. Furthermore, the expression of Msi2 decreased significantly during the aging process of mice, indicating that decreased Msi2 function during aging contributes to abnormal accumulation of adipocytes in bone marrow and osteoporosis. Thus, our results provide a putative biochemical mechanism for aging-related osteoporosis, suggesting that modulating Msi2 function may benefit the treatment of bone aging.

Cancer-associated fibroblasts in digestive tumors

The significant influence of tumor stroma on malignant cells has been extensively investigated in this era of targeted therapy. The tumor microenvironment, as a dynamic system, is orchestrated by various cells including tumor vascular composing cells, inflammatory cells and fibroblasts. As a major and important component in tumor stroma, increasing evidence has shown that spindle-shaped cancer-associated fibroblasts (CAFs) are a significant modifier of cancer evolution, and promote tumorigenesis, tumor invasion and metastasis by stimulating angiogenesis, malignant cell survival, epithelial-mesenchymal transition (EMT) and proliferation via direct cell-to-cell contact or secretion of soluble factors in most digestive solid tumors. CAFs are thought to be activated, characterized by the expression of &#x003b1;-smooth muscle actin, fibroblast activated protein, fibroblast specific protein, vimentin, fibronectin, etc. They are hypothesized to originate from normal or aged fibroblasts, bone marrow-derived mesenchymal cells, or vascular endothelial cells. EMT may also be an important process generating CAFs, and most probably, CAFs may originate from multiple cells. A close link exists between EMT, tumor stem cells, and chemo-resistance of tumor cells, which is largely orchestrated by CAFs. CAFs significantly induce immunosuppression, and may be a prognostic marker in various malignancies. Targeted therapy toward CAFs has displayed promising anticancer efficacy, which further reinforces the necessity to explore the relationship between CAFs and their hosts.