Role of the tumor microenvironment in pancreatic adenocarcinoma.

Pancreatic cancer is a devastating disease with proclivity for early metastasis, which accounts for its poor prognosis. The clinical problem of pancreatic cancer is its resistance to conventional therapies, such as chemotherapy or radiation. Based upon these challenges, the focus of research on pancreatic cancer has shifted gradually towards the tumor microenvironment. The cancer microenvironment consists of various components, including fibroblasts, endothelial cells, immune cells, and endocrine cells, that interact with each other, and with the cancer cells in a complex fashion. Evidence is accumulating that the cancer microenvironment plays an active role in disease progression, and efforts are being made to target this interplay between cancer cells and host cells, to improve the prognosis of the disease. In the present review, we describe the cellular microenvironment of pancreatic ductal adenocarcinoma (PDA), the major type of pancreatic cancer. Our hope is that a better understanding of the cellular microenvironment of PDA will eventually lead to better treatments for this disease.

MicroRNA-29a Promotes Pancreatic Cancer Growth by Inhibiting Tristetraprolin.

BACKGROUND/AIMS: The microRNA (miR) 29 family has been studied extensively for its involvement in several diseases, and aberrant expression of its members is associated with tumorigenesis and cancer progression. Here, we examined the role of miR-29a in pancreatic cancer and the involvement of tristetraprolin (TTP). METHODS: We monitored miR-29a and TTP expression in pancreatic cancer by qRT-PCR and western blotting. The effect of miR-29a on pancreatic cancer was determined through MTT assay and migration assay. The results were validated in the tumorigenesis model. RESULTS: We found that miR-29a was up regulated in pancreatic tumor tissues and cell lines and positively correlated with metastasis. Ectopic expression of miR-29a increased the expression of pro-inflammatory factors and epithelial-mesenchymal transition (EMT) markers, through down regulating TTP. TTP was down regulated in tumor tissues, and its ectopic expression decreased cell viability and migration in vitro, inhibited tumor growth and the EMT phenotype in vivo, and reversed the effect of miR-29a on tumor cell proliferation and invasion in vitro and in vivo. CONCLUSION: Our results suggest that miR-29a acts as an oncogene by down regulating TTP and provide the basis for further studies exploring the potential of miR-29a and TTP as biomarkers and targets for the treatment of pancreatic cancer.

Application of chemokine receptor antagonist with stents reduces local inflammation and suppresses cancer growth.

Severe pain and obstructive jaundice resulting from invasive cholangiocarcinoma or pancreatic carcinoma can be alleviated by implantation of biliary and duodenal stents. However, stents may cause local inflammation to have an adverse effect on the patients' condition and survival. So far, no efficient approaches have been applied to prevent the occurrence of stents-related inflammation. Here, we reported significantly higher levels of serum stromal cell-derived factor 1 (SDF-1) in the patients that developed stents-associated inflammation. A higher number of inflammatory cells have been detected in the cancer close to stent in the patients with high serum SDF-1. Since chemokine plays a pivotal role in the development of inflammation, we implanted an Alzet osmotic pump with the stents to gradually release AMD3100, a specific inhibitor binding of SDF-1 and its receptor C-X-C chemokine receptor 4 (CXCR4), at the site of stents in mice that had developed pancreatic cancer. We found that AMD3100 significantly reduced local inflammation and significantly inhibited cancer cell growth, resulting in improved survival of the mice that bore cancer. Moreover, the suppression of cancer growth may be conducted through modulation of CyclinD1, p21, and p27 in the cancer cells. Together, these data suggest that inhibition of chemokine signaling at the site of stents may substantially improve survival through suppression of stent-related inflammation and tumor growth.

Percutaneous needle decompression in treatment of malignant small bowel obstruction.

AIM: To investigate the efficacy and safety of percutaneous needle decompression in the treatment of malignant small bowel obstruction (MSBO). METHODS: A prospective analysis of the clinical data of 52 MSBO patients undergoing percutaneous needle decompression was performed. RESULTS: Percutaneous needle decompression was successful in all 52 patients. Statistically significant differences were observed in symptoms such as vomiting, abdominal distension and abdominal pain before and after treatment (81.6% vs 26.5%, 100% vs 8.2%, and 85.7% vs 46.9%, respectively; all P < 0.05). The overall significantly improved rate was 19.2% (11/52) and the response rate was 94.2% (49/52) using decompression combined with nasal tube placement, local arterial infusion of chemotherapy and nutritional support. During the one-month follow-up period, puncture-related complications were acceptable. CONCLUSION: Percutaneous needle intestinal decompression is a safe and effective palliative treatment for MSBO.

Objective tongue inspection on 142 liver cancer patients with damp-heat syndrome.

OBJECTIVE: To establish the diagnosis evidence of objective tongue inspection for liver cancer (LC) patients with damp-heat syndrome (DHS) by dynamically observing their tongue figures using modern tongue image analytic apparatus, and to explore the effect of intervention on the tongue figures. METHODS: Tongue figures were collected from 142 LC patients with DHS by tongue image analytic apparatus. Red (R), green (G) and blue (B) values were analyzed. The r and g values were calculated requesting r=R/(R+G+B), g=G/(R+G+B), and b=1-r-g, and scored in combination with Chinese medical symptoms scale. The tongue figure and correlated scores were collected from 59 of them 3 days after transcatheter arterial chemoembolization intervention. RESULTS: The range of objective tongue inspection of LC patients with DHS was as follows: as for tongue fur, 0.360

Traditional chinese medicine tongxinluo improves cardiac function of rats with dilated cardiomyopathy.

The study aimed at testing the hypothesis that tongxinluo capsule might exert its cardioprotective effect by preventing ventricular remodeling and improving coronary microvascular function in a rat model of doxorubicin-induced dilated cardiomyopathy (DCM). Rats that survived DCM induction were randomly divided into three groups to be given 1.5 g·kg(-1)·day(-1) (TXL-H, n = 9) or 0.15 g·kg(-1)·day(-1) (TXL-L, n = 10) of tongxinluo, or normal saline at the same volume (DCM-C, n = 10) intragastrically. Age matched normal rats treated with normal saline were used as normal controls (NOR-C, n = 9). After four weeks of treatment, the DCM-C, TXL-H, and TXL-L groups exhibited significant cardiac dysfunction, left ventricular remodeling, and coronary microvascular dysfunction, compared with the NOR-C rats. However, myocardial functional parameters were significantly improved and microvascular density (MVD) increased in the TXL-H group compared with the DCM-C group (all P < 0.01). Left ventricular remodeling was prevented. There were close linear relationships between CVF and LVEF (r = -0.683, P < 0.05), MVD and LVEF (r = 0.895, P < 0.05), and MVD and CVF (r = -0.798, P < 0.05). It was indicated that high-dose tongxinluo effectively improved cardiac function in rat model of DCM.

Combined radiochemotherapy in patients with locally advanced pancreatic cancer: a meta-analysis.

AIM: To compare the long-term clinical efficacy of chemotherapy plus radiotherapy (CRT) with that of radiotherapy alone (RT) or chemotherapy alone (CT) for locally advanced pancreatic carcinoma (LAPC). METHODS: Using manual and computer-aided methods, we searched the data through the databases, including PubMed/EmBase/CNKI/CQVIP/China Journals Full Text Database and websites and proceedings of major annual meetings such as ASCO and CSCO. The methodological quality of the included studies was assessed using the Jadad scoring system. Both English and Chinese publications were searched. We collected data from controlled clinical trials on CRT vs RT or CT for LAPC, and conducted a meta-analysis of 15 included studies. Meta-analysis was performed using RevMan4.2 Software according to the method recommended by Cochrane Collaboration. RESULTS: Fifteen eligible randomized controlled trials including a total of 1128 patients were screened. Jadad score was 2 in only one article, and 3-4 in the remaining 14 studies. The meta-analysis showed that CRT was superior in the 6- and 12-mo survivals to the RT alone group or CT alone group (P = 0.0001 and P = 0.02, respectively), whereas the 18-mo survival showed no significant difference (P = 0.23). Subgroup analysis showed that the 6-, 12-, and 18-mo survivals were not significantly different between the CRT group and CT group (P = 0.07, P = 0.23, and P = 0.91, respectively). Notably, the CRT group had significantly better 6-, 12-, and 18-mo survivals than the RT group (all P < 0.01). CRT group had significantly more grade 3-4 treatment-related hematologic and non-hematologic toxicities than the CT group or RT group (all P < 0.01). CONCLUSION: Compared with CT or RT, CRT can benefit the long-term survival of LAPC patients, although it may also increase treatment-related toxicities.

ShRNA-targeted MAP4K4 inhibits hepatocellular carcinoma growth.

PURPOSE: Mitogen-activated protein kinase kinase kinase kinase 4 (MAP4K4) is overexpressed in many types of cancer. Herein, we aimed to investigate its expression pattern, clinical significance, and biological function in hepatocellular carcinoma (HCC). EXPERIMENTAL DESIGN: MAP4K4 expression was examined in 20 fresh HCCs and corresponding nontumor liver tissues. Immunohistochemistry for MAP4K4 was performed on additional 400 HCCs, of which 305 (76%) were positive for hepatitis B surface antigens. The clinical significance of MAP4K4 expression was analyzed. MAP4K4 downregulation was performed in HCC cell lines HepG2 and Hep3B with high abundance of MAP4K4, and the effects of MAP4K4 silencing on cell proliferation in vitro and tumor growth in vivo were evaluated. Quantitative real-time PCR arrays were employed to identify the MAP4K4-regulated signaling pathways. RESULTS: MAP4K4 was aberrantly overexpressed in HCCs relative to adjacent nontumor liver tissues. This overexpression was significantly associated with larger tumor size, increased histologic grade, advanced tumor stage, and intrahepatic metastasis, as well as worse overall survival and higher early recurrence rate. Knockdown of the MAP4K4 expression reduced cell proliferation, blocked cell cycle at S phase, and increased apoptosis. The antitumor effects of MAP4K4 silencing were also observed in vivo, manifested as retarded tumor xenograft growth. Furthermore, multiple tumor progression-related signaling pathways including JNK, NFκB, and toll-like receptors were repressed by MAP4K4 downregulation. CONCLUSIONS: MAP4K4 overexpression is an independent predictor of poor prognosis of HCC patients, and inhibition of its expression might be of therapeutic significance.

Accumulation of phenanthrene by roots of intact wheat (Triticum acstivnm L.) seedlings: passive or active uptake?

BACKGROUND: Polycyclic aromatic hydrocarbons (PAHs) are of particular concern due to their hydrophobic, recalcitrant, persistent, potentially carcinogenic, mutagenic and toxic properties, and their ubiquitous occurrence in the environment. Most of the PAHs in the environment are present in surface soil. Plants grown in PAH-contaminated soils or water can become contaminated with PAHs because of their uptake. Therefore, they may threaten human and animal health. However, the mechanism for PAHs uptake by crop roots is little understood. It is important to understand exactly how PAHs are transported into the plant root system and into the human food chain, since it is beneficial in governing crop contamination by PAHs, remedying soils or waters polluted by PAHs with plants, and modeling potential uptake for risk assessment. RESULTS: The possibility that plant roots may take up phenanthrene (PHE), a representative of PAHs, via active process was investigated using intact wheat (Triticum acstivnm L.) seedlings in a series of hydroponic experiments. The time course for PHE uptake into wheat roots grown in Hoagland solution containing 5.62 microM PHE for 36 h could be separated into two periods: a fast uptake process during the initial 2 h and a slow uptake component thereafter. Concentration-dependent PHE uptake was characterized by a smooth, saturable curve with an apparent Km of 23.7 microM and a Vmax of 208 nmol g(-1) fresh weight h(-1), suggesting a carrier-mediated uptake system. Competition between PHE and naphthalene for their uptake by the roots further supported the carrier-mediated uptake system. Low temperature and 2,4-dinitrophenol (DNP) could inhibit PHE uptake equally, indicating that metabolism plays a role in PHE uptake. The inhibitions by low temperature and DNP were strengthened with increasing concentration of PHE in external solution within PHE water solubility (7.3 muM). The contribution of active uptake to total absorption was almost 40% within PHE water solubility. PHE uptake by wheat roots caused an increase in external solution pH, implying that wheat roots take up PHE via a PHE/nH+ symport system. CONCLUSION: It is concluded that an active, carrier-mediated and energy-consuming influx process is involved in the uptake of PHE by plant roots.

[Impact of dissolved organic matter on plant uptake of phenanthrene and its mechanisms].

Hydroponic assays were conducted to investigate the influence of dissolved organic matter on uptake of phenanthrene by wheat as well as its mechanisms. The results showed that, under hydroponic condition, phenanthrene impairment of plant growth occurred with wheat growth inhibited rate of 18.01%. The impairment would be greatly enhanced in the presence of dissolved organic matter (DOM) derived from pig manure, and the inhibited rate increased to 24.38%. Wheat could uptake and accumulate phenanthrene in the nutrient solution, which could be escalated by DOM, as indicated by wheat root bioconcentration factor being increased to 37.63 L x kg(-1) in the presence of DOM from 2.84 L x kg(-1) in the absence of DOM. At the same time, DOM could facilitate phenanthrene translocation from plant roots to the upper. As a result, the pH value of nutrient solution could increase by more than 1 unit when the co-existence of DOM and phenanthrene occurred in solution, suggesting that H+ -phenanthrene cotransport system is involved in the uptake of phenanthrene by plants. A synergism was also found between wheat uptakes of phenanthrene and inorganic nutrients, Moreover, DOM accelerated markedly the synergism. It is concluded that DOM affects the uptake of phenanthrene by plants and the environmental behaviors of phenanthrene.