Chinese herbal medicine suppresses invasion-promoting capacity of cancer-associated fibroblasts in pancreatic cancer

Asperuloside inhibits the activation of pancreatic cancer-associated fibroblasts via activating transcription factor 6

BACKGROUND

Pancreatic cancer-associated fibroblasts (CAFs) play a crucial role in tumor progression and immune evasion. Asperuloside (ASP) is an iridoid glycoside with potential anti-tumor properties. This study aimed to explore the molecular mechanisms of ASP on CAFs, particularly focusing on its effects on activating transcription factor 6 (ATF6), a key regulator of endoplasmic reticulum stress.

METHOD

CAFs were treated with different concentrations of ASP (0, 1, 3, and 5 mM), and the role of ATF6 was investigated by over-expressing it in CAFs. Subsequently, western blot was used to detect ATF6, α-smooth muscle actin (α-SMA), fibroblast activating protein (FAP), and vimentin protein levels in CAFs. The collagen gel contraction assay and Transwell assay were applied to evaluate the contraction and migration ability of CAFs. In addition, the interleukin (IL)-6, C-C motif chemokine ligand (CCL)-2, and C-X-C motif chemokine ligand (CXCL)-10 levels were detected by reverse transcription-quantitative polymerase chain reaction (RT-qPCR).

RESULTS

CAFs had significantly higher expression levels of α-SMA, FAP, and vimentin compared to normal fibroblasts (NFs). ASP significantly inhibited the activation, contraction, and migration of CAFs in a concentration-dependent manner. ASP treatment also reduced the expression of cytokines (IL-6, CCL2, and CXCL10) and down-regulated ATF6 levels. Over-expression of ATF6 mitigated the inhibitory effects of ASP.

CONCLUSION

ASP exerts its anti-tumor effects by down-regulating ATF6, thereby inhibiting the activation and function of pancreatic CAFs. These findings suggest that ASP could be a promising therapeutic agent for pancreatic cancer by modulating the tumor microenvironment.

Potential Effects of Traditional Chinese Medicine in Anti-Aging and Aging-Related Diseases: Current Evidence and Perspectives

Aging and aging-related diseases present a global public health problem. Therefore, the development of efficient anti-aging drugs has become an important area of research. Traditional Chinese medicine is an important complementary and alternative branch of aging-related diseases therapy. Recently, a growing number of studies have revealed that traditional Chinese medicine has a certain delaying effect on the progression of aging and aging-related diseases. Here, we review the progress in research into using traditional Chinese medicine for aging and aging-related diseases (including neurodegenerative diseases, cardiovascular diseases, diabetes, and cancer). Furthermore, we summarize the potential mechanisms of action of traditional Chinese medicine and provide references for further studies on aging and aging-related diseases.

The Role of Traditional Chinese Medicine in Cancer Immunotherapy: Current Status and Future Directions

The tumor microenvironment (TME) plays an important role in the development of tumors. Immunoregulatory cells and cytokines facilitate cancer cells to avoid immune surveillance. Overexpression of immune checkpoint molecules such as CTLA-4 and PD-1/PD-L1 inhibits immune function and enables cancer cells to avoid clearance by the immune system. Thus, minimizing tumor immunosuppression could be an important strategy for cancer therapy. Currently, many immune checkpoint-targeted drugs, such as PD-1/PD-L1 inhibitors, have been approved for marketing and have shown unique advantages in the clinical treatment of cancers. The concept of "strengthening resistance to eliminate pathogenic factors" in traditional Chinese medicine (TCM) is consistent with the immunotherapy of cancer. According to previous studies, the role of TCM in tumor immunotherapy is mainly associated with the positive regulation of natural killer cells, CD8/CD4 T cells, dendritic cells, M2 macrophages, interleukin-2, tumor necrosis factor-[Formula: see text], and IFN-[Formula: see text], as well as with the negative regulation of Tregs, myeloid-derived suppressor cells, cancer-associated fibroblasts, PD-1/PD-L1, transforming growth factor-[Formula: see text], and tumor necrosis factor-[Formula: see text]. This paper summarizes the current research on the effect of TCM targeting the TME, and further introduces the research progress on studying the effects of TCM on immune checkpoints. Modern pharmacological studies have demonstrated that TCM can directly or indirectly affect the TME by inhibiting the overexpression of immune checkpoint molecules and enhancing the efficacy of tumor immunotherapy. TCM with immunomodulatory stimulation could be the key factor to achieve benefits from immunotherapy for patients with non-inflammatory, or "cold", tumors.

Integrating network pharmacology and experimental models to investigate the efficacy of QYHJ on pancreatic cancer

ETHNOPHARMACOLOGICAL RELEVANCE

The Qingyihuaji decoction (QYHJ) is composed of seven herbs: Scutellaria barbata D.Don (Banzhilian, HSB), Gynostemma pentaphyllum (Thunb.) Makino (Jiaogulan, GP), Oldenlandia diffusa (Willd.) Roxb. (Baihuasheshecao, HDH), Ganoderma lucidum (Leyss. ex Fr.) Karst. (Lingzhi, GL), Myristica fragrans Houtt. (Doukou, AK), and Amorphophallus kiusianus (Makino) Makino (Sheliugu, RA), and Coix lacryma-jobi var. ma-yuen (Rom.Caill.) Stapf (Yiyiren, CL). QYHJ has been reported to exhibit clinical efficacy in the treatment of pancreatic adenocarcinoma (PAAD). However, the molecular mechanism remains unclear.

AIM OF THE STUDY

This study explores the therapeutic mechanism of QYHJ in the treatment of PAAD using network pharmacology to identify related targets and pathways in vivo and in vitro.

MATERIALS AND METHODS

The bioactive compounds of QYHJ were retrieved and screened using the ADME network pharmacology approach, followed by compound-target prediction and overlapping genes between PAAD oncogenes and QYHJ target genes. The compound-target-pathway network was established using The KEGG pathway, GO analysis, and the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway and Gene Ontology (GO) analysis to identify potential action pathways. The effects of QYHJ on PAAD were evaluated in vivo and in vitro, and the predicted targets and potential pathways related to QYHJ in PAAD treatment were evaluated using qRT-PCR and immunoblotting.

RESULTS

A total of 68 bioactive compounds of QYHJ fulfilled the ADME screening criterion, and their respective 242 target genes were retrieved. The compound-target-disease network identified 11 possible target genes. The KEGG pathway analysis showed significant enrichment of pathways in cancers, involving regulating cancer-related pathways of inflammation, oxidative stress, and apoptosis. Furthermore, QYHJ inhibited PAAD growth in vivo; suppressed cell proliferation, invasion, and migration of PAAD; and induced cellular apoptosis in vitro. The qRT-PCR results showed that QYHJ suppressed the mRNA expression of ICAM1, VCAM1, and Bcl2, and increased that of HMOX1 and NQO1. Immunoblotting revealed changes in the PI3K/AKT/mTOR, Keap1/Nrf2/HO-1/NQO1, and Bcl2/Bax pathways upon QYHJ treatment.

CONCLUSIONS

QYHJ can suppress PAAD growth and progression through various mechanisms, including anti-inflammation and apoptosis-induction.

A Mouse Model of Damp-Heat Syndrome in Traditional Chinese Medicine and Its Impact on Pancreatic Tumor Growth

Background

Damp-heat syndrome is one of the most important syndrome types in the traditional Chinese medicine (TCM) syndrome differentiation and treatment system, as well as the core pathogenesis of pancreatic cancer (PC) which remains a challenge to medical researchers due to its insidious onset and poor prognosis. Great attention has been given to the impact of damp-heat syndrome on tumorigenesis and progression, but less attention has been given to damp-heat modeling per se. Studying PC in a proper damp-heat syndrome animal model can recapitulate the actual pathological process and contribute to treatment strategy improvement.

Methods

Here, an optimized damp-heat syndrome mouse model was established based on our prior experience. The Fibonacci method was applied to determine the maximum tolerated dosage of alcohol for mice. Damp-heat syndrome modeling with the old and new methods was performed in parallel of comparative study about general appearance, food intake, water consumption and survival. Major organs, including the liver, kidneys, lungs, pancreas, spleen, intestines and testes, were collected for histological evaluation. Complete blood counts and biochemical tests were conducted to characterize changes in blood circulation. PC cells were subcutaneously inoculated into mice with damp-heat syndrome to explore the impact of damp-heat syndrome on PC growth. Hematoxylin-eosin staining, Masson staining and immunohistochemistry were performed for pathological evaluation. A chemokine microarray was applied to screen the cytokines mediating the proliferation-promoting effects of damp-heat syndrome, and quantitative polymerase chain reaction and Western blotting were conducted for results validation.

Results

The new modeling method has the advantages of mouse-friendly features, easily accessible materials, simple operation, and good stability. More importantly, a set of systematic indicators was proposed for model evaluation. The new modeling method verified the pancreatic tumor-promoting role of damp-heat syndrome. Damp-heat syndrome induced the proliferation of cancer-associated fibroblasts and promoted desmoplasia. In addition, circulating and tumor-located chemokine levels were altered by damp-heat syndrome, characterized by tumor promotion and immune suppression.

Conclusions

This study established a stable and reproducible murine model of damp-heat syndrome in TCM with systematic evaluation methods. Cancer associated fibroblast-mediated desmoplasia and chemokine production contribute to the tumor-promoting effect of damp-heat syndrome on PC.

Evaluating the efficacy of an innovative herbal formulation (HF6) on different human cancer cell lines

Cancer is reported to be the leading cause of death and illness worldwide. This research aims to evaluate the phytochemicals, antioxidant, cytotoxic, and apoptotic activities of the polyherbal formulation HF6. HF6 was prepared by blending equal quantities of plants powder, namely, Curcuma longa, Salvia officinalis, Cinnamomum zeylanicum, Capsicum annuum, Zingiber officinale, and Syzygium aromaticum, and later extracted using hexane (HF6H), chloroform (HF6C), ethyl acetate (HF6E), and methanol (HF6M) in Soxhlet apparatus. Among the four different extracts, only the hexane extract (HF6H) was significantly effective. The HF6H extract showed antioxidant and anticancer potentials against different cancer cell lines, and moderate cytotoxicity against non-cancer cells, rendering it a promising remedy. In addition, it exerted tremendous cytotoxic effects on MCF-7, Huh-7, HCT116, MDA-MB-231, LoVo, and HepG2 cells with IC50 values of 2.02, 4.5, 6.9, 11.4, 23.5, and 34.7 µg/mL, respectively. The morphological hallmarks of apoptosis such as the rounding of cells, loss of contact with neighboring cells, formation of cell membrane blebbing, and microspike protrusion were detected using several different techniques. DAPI staining revealed apoptotic nuclear morphology such as condensation and DNA fragmentation. The morphological changes of MCF7 cells were also analyzed by AO/EB fluorescence staining. MCF7-stained green cells were viable cells, whereas the treated cells showed fragmented green nuclei representing early apoptosis. The phytochemical screening of HF6H showed positive results regarding the presence of alkaloids, polyphenols, flavonoids, and sterols. The GC-MS (gas chromatography-mass spectrometry) analysis of the HF6H extract indicated the presence of 12 compounds, mainly trans-caryophyllene (21.55%), cis-isoeugenol (18.42%), acetyleugenol (17.53%), alpha farnesene (10.0%), and zingiberene (8.55%). However, further investigation could be carried out to examine the toxicity of the extract on animal models.

Single-cell analysis on stromal fibroblasts in the microenvironment of solid tumours

Besides malignant cells, the tumour microenvironment consists of various stromal cells such as cancer-associated fibroblasts (CAFs) and myofibroblasts. Accumulation of heterogeneous populations of stromal cells in solid tumours is associated with lower survival rates and cancer recurrence in patients. Certain limitations presented by conventional experimental designs and techniques in cancer research have led to poor understanding of the fundamental basis of cancer niche. Recent developments in single-cell techniques allow more in-depth studies of the tumour microenvironment. Analyses at the single-cell level enables the detection of rare cell types, characterization of intra-tumour cellular heterogeneity and analysis of the lineage output of malignant cells. This subsequently, provides valuable insights on better diagnostic methods and treatment avenues for cancer. This review explores the recent advancements and applications of single-cell technologies in cancer research pertaining to the study of stromal fibroblasts in the microenvironment of solid tumours.

PGC1α suppresses kidney cancer progression by inhibiting collagen-induced SNAIL expression

The transcriptional events that promote invasive and metastatic phenotypes in renal cell carcinoma (RCC) remain poorly understood. Here we report that the decreased expression of peroxisome proliferator-activated receptor gamma, coactivator 1 alpha (PGC1α) and the increased expression of several genes encoding collagen family members are associated with RCC tumor progression. PGC1α restoration attenuates invasive phenotypes and suppresses tumor progression in vivo. In contrast, collagens produced by RCC cells promote invasive and migratory phenotypes. PGC1α restoration suppresses the expression of collagens and tumor phenotypes via the induction of miR-29a. Furthermore, decreased collagens via the PGC1α/miR-29a axis suppresses collagen-mediated activation of discoidin domain receptor 1 (DDR1)/ERK signaling. In turn, the suppression of collagen/DDR1 signaling by PGC1α leads to decreased levels of the known EMT regulators SNAIL1 and 2. Collectively, our results demonstrate a novel role for PGC1α in the regulation of proinvasive SNAIL proteins.

Ocoxin Oral Solution Exerts an Antitumoral Effect in Pancreatic Cancer and Reduces the Stromal-Mediated Chemoresistance

OBJECTIVES

Pancreatic carcinoma is one of the most aggressive cancers overcoming chemoresistance. Thus, novel compounds to complement the current antitumor agents are in need. Ocoxin oral solution (OOS) has proven antioxidant, anti-inflammatory, and antistromagenic properties. The aim of this study was to analyze the effect of OOS in an experimental pancreatic cancer model and its implication in stroma-related chemoresistance to paclitaxel and gemcitabine.

METHODS

Murine pancreatic carcinoma 266-6 cells were treated with OOS to analyze cell cycle and to perform a mRNA comparative microarray study. Then the viability was assessed in combination with paclitaxel and/or gemcitabine. Chemoresistance induced by the medium taken from fibroblast cultures was also investigated on 6 human pancreatic carcinoma cell lines. Furthermore, an experimental model of pancreatic cancer was carried out to study the effect of OOS in vivo.

RESULTS

Ocoxin oral solution enhances the cytotoxic effect of paclitaxel and gemcitabine, while it ameliorates the chemoresistance induced by fibroblast-derived soluble factors in human pancreatic cancer cells. The OOS also promotes the regulation of the expression of genes that are altered in pancreatic carcinoma and slows down 266-6 cell pancreatic tumor development in vivo.

CONCLUSIONS

Ocoxin oral solution could be a potential complement to the chemotherapeutic drugs for pancreatic adenocarcinoma.

Cancer-Associated Fibroblasts in Pancreatic Cancer: Should They Be Deleted or Reeducated?

Pancreatic ductal adenocarcinoma is characterized by an extensive stromal response called desmoplasia. Within the tumor stroma, cancer-associated fibroblasts (CAFs) are the primary cell type. CAFs have been shown to play a role in pancreatic cancer progression; they secrete growth factors, inflammatory cytokines, and chemokines that stimulate signaling pathways in cancer cells and modulate the cancer biology toward increased aggressiveness. Therefore, targeting CAFs may serve as a powerful weapon against pancreatic cancer and improve therapeutic effects. However, a previous study aiming to deplete CAFs by inhibiting sonic Hedgehog signaling failed to show any benefit in survival time of pancreatic cancer patients. We reported that the natural product curcumin reeducated CAFs in pancreatic cancer treatment. A low concentration of curcumin reversed the activation of fibroblasts without exhibiting growth suppression effects. In addition, curcumin suppressed CAF-induced pancreatic cancer cell migration and invasion in vitro and lung metastasis in vivo. The results of our study suggest that active CAFs can be inactivated by certain natural products such as curcumin. Reeducation of CAFs back to their normal state, rather than their indiscriminate depletion, may broaden our view in the development of therapeutic options for the treatment of pancreatic cancer.

Functions of the CXC ligand family in the pancreatic tumor microenvironment

Therapeutic resistance is the major contributor to the poor prognosis of and low survival from pancreatic cancer (PC). Cancer progression is a complex process reliant on interactions between the tumor and the tumor microenvironment (TME). Members of the CXCL family of chemokines are present in the pancreatic TME and seem to play a vital role in regulating PC progression. As pancreatic tumors interact with the TME and with PC stem cells (CSCs), determining the roles of specific members of the CXCL family is vital to the development of improved therapies. This review highlights the roles of selected CXCLs in the interactions between pancreatic tumor and its stroma, and in CSC phenotypes, which can be used to identify potential treatment targets.

Effects of baicalein on pancreatic cancer stem cells via modulation of sonic Hedgehog pathway

Recent studies have suggested that sonic Hedgehog (Shh) signaling pathway is aberrantly activated in cancer stem cells (CSCs). A seven-herb Chinese medicinal formula composed of Amorphophallus rivieri Durieu, Oldenlandia diffusa (Wild) Roxb, Scutellaria barbata D. Don, Gynostemma pentaphyllum (Thunb.) Mak and Amomum cardamomum L, i.e. Qingyihuaji (QYHJ) formula, has been shown to inhibit proliferation of pancreatic CSCs by inhibiting Shh signaling pathway and thereby prolong the overall survival of pancreatic cancer patients. Mass spectrometry analysis revealed that baicalein is one of the major compounds of QYHJ formula. The objective of this study was to investigate the role of Shh pathway in pancreatic cancer and to examine the molecular mechanisms of baicalein involved in pancreatic cancer treatment. We examined the effects of baicalein on pancreatic CSCs both in vivo and in vitro. The results indicated that baicalein attenuated the pluripotency of pancreatic CSCs. Then, we investigated the underlying mechanism and found that nuclear transcription factors, such as Sox-2 and Oct-4 as well as members in Shh signaling pathway, e.g. SHH, SMO, and Gli-2, were downregulated after baicalein treatment. Furthermore, silencing Gli-2 expression by small interfering RNA decreased Sox-2 expression and blocked the inhibitory effects of baicalein, suggesting that the effects of baicalein may be mediated through inhibition of Shh pathway. Our results suggested that baicalein, an active compound in QYHJ formula, could suppress the self-renewal of pancreatic CSCs through inhibition of Shh signaling pathway.

Resistance a major hindrance to chemotherapy in hepatocellular carcinoma: an insight

Hepatocellular carcinoma (HCC) is one of the leading causes of cancer mortality, accounting for almost 90% of total liver cancer burden. Surgical resection followed by adjuvant and systemic chemotherapy are the most meticulously followed treatment procedures but the complex etiology and high metastatic potential of the disease renders surgical treatment futile in majority of the cases. Another hindrance to the scenario is the acquired resistance to drugs resulting in relapse of the disease. Hence, to provide insights into development of novel therapeutic targets and diagnostic biomarkers, this review focuses on the various molecular mechanisms underlying chemoresistance in HCC. We have provided a comprehensive summary of the various strategies adopted by HCC cells, extending from apoptosis evasion, autophagy activation, drug expulsion to epigenetic transformation as modes of therapy resistance. The role of stem cells in imparting chemoresistance is also discussed. Furthermore, the review also focuses on how this knowledge might be exploited for the development of an effective, prospective therapy against HCC.

Chinese medicine formula "Shenqi San" extract inhibits proliferation of human lung adenocarcinoma A549 cells via inducing apoptosis

The main purpose of this study was to investigate the active components of the Chinese medicine formula Shenqi San (SS) by high performance liquid chromatography with diode array detector and electrospray ionization-hybrid quadrupole time-of-flight mass spectrum (HPLC-DADESI- QTOF-MS), and demonstrate the anticancer mechanism of SS on human lung adenocarcinoma A549 cells by evaluating the cell proliferation and apoptosis induction. The chloroform extraction of SS (CE-SS) was extracted from SS, while HPLC-DAD-ESI-QTOF-MS assay was performed to identify components of CE-SS. MTT assay was used to quantify the proliferation of A549 cells with the treatment of CE-SS. Apoptosis analysis was carried out by detecting phosphatidylserine (PS) externalization using the Annexin V-FITC Apoptosis Detection Kit and the stained cells were analyzed with a flow cytometer. DAPI staining assay was carried out to observe morphological characteristics of apoptotic cells. Western blotting was used to detect the expression of important signaling proteins including caspase-3, -8, -9, p53, Bax and Bcl-2. Eight compounds were identified through HPLC-DAD-ESI-QTOF-MS analysis and 3-pyridine carboxylic acid, barbatin C, scutebarbatine F and barbatine D might be the main compounds responsible for the antitumor effect of CE-SS. CE-SS suppressed the proliferation of lung cancer A549 cells in a time- and dose-dependent manner. By Annexin V-FITC/PI double staining, we found that treatment with CE-SS induced apoptosis in A549 cells. After 24-h exposure to CE-SS, the expression of cleaved-caspase-9, cleaved-caspase-8 and cleaved-caspase-3 protein was activated, the expression of p53 protein increased while the ratio of Bax/Bcl-2 also increased. This study identified the eight compounds of CE-SS, and demonstrated their anticancer effect on human lung adenocarcinoma A549 cells via induction of apoptosis.

Fibrogenic Lung Injury Induces Non-Cell-Autonomous Fibroblast Invasion

Pathologic accumulation of fibroblasts in pulmonary fibrosis appears to depend on their invasion through basement membranes and extracellular matrices. Fibroblasts from the fibrotic lungs of patients with idiopathic pulmonary fibrosis (IPF) have been demonstrated to acquire a phenotype characterized by increased cell-autonomous invasion. Here, we investigated whether fibroblast invasion is further stimulated by soluble mediators induced by lung injury. We found that bronchoalveolar lavage fluids from bleomycin-challenged mice or patients with IPF contain mediators that dramatically increase the matrix invasion of primary lung fibroblasts. Further characterization of this non-cell-autonomous fibroblast invasion suggested that the mediators driving this process are produced locally after lung injury and are preferentially produced by fibrogenic (e.g., bleomycin-induced) rather than nonfibrogenic (e.g., LPS-induced) lung injury. Comparison of invasion and migration induced by a series of fibroblast-active mediators indicated that these two forms of fibroblast movement are directed by distinct sets of stimuli. Finally, knockdown of multiple different membrane receptors, including platelet-derived growth factor receptor-β, lysophosphatidic acid 1, epidermal growth factor receptor, and fibroblast growth factor receptor 2, mitigated the non-cell-autonomous fibroblast invasion induced by bronchoalveolar lavage from bleomycin-injured mice, suggesting that multiple different mediators drive fibroblast invasion in pulmonary fibrosis. The magnitude of this mediator-driven fibroblast invasion suggests that its inhibition could be a novel therapeutic strategy for pulmonary fibrosis. Further elaboration of the molecular mechanisms that drive non-cell-autonomous fibroblast invasion consequently may provide a rich set of novel drug targets for the treatment of IPF and other fibrotic lung diseases.

Curcumin suppresses epithelial-to-mesenchymal transition and metastasis of pancreatic cancer cells by inhibiting cancer-associated fibroblasts

Pancreatic cancer is one of the most lethal malignancies and the fourth leading cause of cancer-related deaths worldwide, because of its aggressive and highly metastatic ability even in its early stages. Cancer-associated fibroblasts (CAFs) have been reported to be vital to pancreatic cancer progression via regulating tumorigenesis and metastasis. Studies have shown that CAFs also mediate epithelial-to-mesenchymal transition (EMT) in tumor cells. Curcumin has recently been reported to have anticancer effects by modulating pathways involved in cancer progression. Therefore, we hypothesized that curcumin might inhibit EMT by targeting CAFs in pancreatic cancer. In this study, we show that the CAF-mediated enhancement of pancreatic cancer cell migration and metastasis was blocked by curcumin. In conclusion, our data provide the first evidence that curcumin inhibits the migration and metastasis of pancreatic cancer cells by reducing the mesenchymal characteristics of CAFs, which reverses the EMT phenotypes of pancreatic cancer cells.

Ski modulate the characteristics of pancreatic cancer stem cells via regulating sonic hedgehog signaling pathway

Evidence from in vitro and in vivo studies shows that Ski may act as both a tumor proliferation-promoting factor and a metastatic suppressor in human pancreatic cancer and also may be a therapeutic target of integrative therapies. At present, pancreatic cancer stem cells (CSCs) are responsible for tumor recurrence accompanied by resistance to conventional therapies. Sonic hedgehog (Shh) signaling pathway is found to be aberrantly activated in CSCs. The objectives of this study were to investigate the role of Ski in modulating pancreatic CSCs and to examine the molecular mechanisms involved in pancreatic cancer treatment both in vivo and in vitro. In in vitro study, the results showed that enhanced Ski expression could increase the expression of pluripotency maintaining markers, such as CD24, CD44, Sox-2, and Oct-4, and also components of Shh signaling pathway, such as Shh, Ptch-1, Smo, Gli-1, and Gli-2, whereas depletion of Ski to the contrary. Then, we investigated the underlying mechanism and found that inhibiting Gli-2 expression by short interfering RNA (siRNA) can decrease the effects of Ski on the maintenance of pancreatic CSCs, indicating that Ski mediates the pluripotency of pancreatic CSCs mainly through Shh pathway. The conclusion is that Ski may be an important factor in maintaining the stemness of pancreatic CSCs through modulating Shh pathway.

Radiation promotes epithelial-to-mesenchymal transition and invasion of pancreatic cancer cell by activating carcinoma-associated fibroblasts

The tumor microenvironment is of crucial importance affecting treatment and prognosis. High degree of carcinoma-associated fibroblast (CAF) infiltration occurs in pancreatic cancer, though its effect on radiotherapy remains unclear. In this study, we demonstrated that radiation enhanced the migration- and invasion-promoting capacity of CAFs both in vitro and in vivo in a lung metastasis model. Radiation exposure increased the expression of CXCL12 by CAFs. CAF-derived CXCL12 promoted tumor cell EMT and invasion directly, acting through CXCR4 on pancreatic cancer cells. In addition, we showed that CXCL12-CXCR4 signaling promoted pancreatic cancer cell EMT and invasion by activating the P38 pathway. Therefore, our study concluded that radiation promoted pancreatic cancer cell invasion and EMT by activating CAFs, while inhibiting the CXCL12/CXCR4 interaction between pancreatic cancer cells and CAFs could potentially attenuate tumor cell invasion induced by radiation, which provides an opportunity for the development of novel therapeutic targets to improve the prognosis for human pancreatic cancer treated with radiation therapy.

Cancer-Associated Fibroblasts: Their Characteristics and Their Roles in Tumor Growth

Cancer tissues are composed of cancer cells and the surrounding stromal cells (e.g., fibroblasts, vascular endothelial cells, and immune cells), in addition to the extracellular matrix. Most studies investigating carcinogenesis and the progression, invasion, metastasis, and angiogenesis of cancer have focused on alterations in cancer cells, including genetic and epigenetic changes. Recently, interactions between cancer cells and the stroma have attracted considerable attention, and increasing evidence has accumulated on this. Several researchers have gradually clarified the origins, features, and roles of cancer-associated fibroblasts (CAFs), a major component of the cancer stroma. CAFs function in a similar manner to myofibroblasts during wound healing. We previously reported the relationship between CAFs and angiogenesis. Interleukin-6 (IL-6), a multifunctional cytokine, plays a central role in regulating inflammatory and immune responses, and important roles in the progression, including proliferation, migration, and angiogenesis, of several cancers. We showed that CAFs are an important IL-6 source and that anti-IL-6 receptor antibody suppressed angiogenesis and inhibited tumor-stroma interactions. Furthermore, CAFs contribute to drug-resistance acquisition in cancer cells. The interaction between cancer cells and the stroma could be a potential target for anti-cancer therapy.

Fat, epigenome and pancreatic diseases. Interplay and common pathways from a toxic and obesogenic environment

The worldwide obesity epidemic is paralleled by a rise in the incidence of pancreatic disorders ranging from "fatty" pancreas to pancreatitis and cancer. Body fat accumulation and pancreatic dysfunctions have common pathways, mainly acting through insulin resistance and low-grade inflammation, frequently mediated by the epigenome. These mechanisms are affected by lifestyle and by the toxic effects of fat and pollutants. An early origin is common, starting in pediatric age or during the fetal life in response to nutritional factors, endocrine disruptor chemicals (EDCs) or parental exposure to toxics. A "fatty pancreas" is frequent in obese and is able to induce pancreatic damage. The fat is a target of EDCs and of the cytotoxic/mutagenic effects of heavy metals, and is the site of bioaccumulation of lipophilic and persistent pollutants related with insulin resistance and able to promote pancreatic cancer. Increased Body Mass Index (BMI) can act as independent risk factor for a more severe course of acute pancreatitis and obesity is also a well-known risk factor for pancreatic cancer, that is related with BMI, insulin resistance, and duration of exposure to the toxic effects of fat and/or of environmental pollutants. All these mechanisms involve gene-environment interactions through epigenetic factors, and might be manipulated by primary prevention measures. Further studies are needed, pointing to better assess the interplays of modifiable factors on both obesity and pancreatic diseases, and to verify the efficacy of primary prevention strategies involving lifestyle and environmental exposure to toxics.