Expression of brain-derived neurotrophic factor and tyrosine kinase B receptor in pancreatic duct cancer and its clinical significance

Objective To determine the expression of brain-derived neurotrophic factor (BDNF) in pancreatic ductal adenocarcinoma and its clinical significance.Methods SP immunohistochemical staining method was used to detect the expression of BDNF in 46 cases of pancreatic ductal adenocarcinoma,38 cases of benign pancreatic diseases and 20 cases of normal pancreatic tissue.Real time PCR and Western blot was used to detect the protein and mRNA expression levels.The relationship between BDNF expression and clinicopathological parameters of pancreatic cancer was determined.Results The positive expression rate of BDNF was 52.2％ (24/46) in pancreatic ductal adenocarcinoma pancreatic ductal adenocarcinoma,7.8％ (3/38) in benign pancreatic diseases,and none of the normal pancreatic tissue was BDNF positive.The BDNF protein expression levels in pancreatic ductal adenocarcinoma,benign pancreatic diseases and normal pancreatic tissue were 0.38± 0.01,0.56± 0.01,0.97± 0.01,respectively,and the BDNF mRNA expression levels were 0.85 ± 0.14,1.67 ± 0.21,3.45 ± 0.67,respectively,and the expression levels in pancreatic ductal adenocarcinoma and benign pancreatic diseases were significantly higher than that in normal pancreatic tissue,while the expression level in pancreatic ductal adenocarcinoma was significantly higher than that in benign pancreatic diseases (P ＜0.05).Positive BDNF expression was correlated with nerve infiltration and lymph node metastasis of pancreatic ductal adenocarcinoma,but it was not related to age,sex,tumor size,location and differentiated degree (P ＞ 0.05).Conclusions BDNF is involved in the development and growth of pancreatic cancer,and it may be related with patient's prognosis. Key words: Pancreatic neoplasms; Brain-derived neurotrophic factor; Neoplasm metastasis; Gene expression

Desmoplasia of Pancreatic Ductal Adenocarcinoma

Nerve growth factor (NGF), the prototypic member of the neurotrophin family of growth factors, exerts both stimulatory and inhibitory effects on neuronal and certain non-neuronal tumors, depending on the type of tumor. It has been reported that two types of NGF receptors, high-affinity receptor, TrkA, and low-affinity receptor, p75NGFR, play important roles in this process. Moreover, it has also been detected that high levels of TrkA expression have a more favorable overall survival prognosis in breast cancer patients, but the relationships between the two receptors according to the prognosis in pancreatic cancer patients are unknown. We investigated the expression of NGF receptors (NGFRs: TrkA and p75NGFR) mRNA in 56 human primary pancreatic cancers, using real-time quantitative reverse transcription-PCR. Moreover, pancreatic cancer cell lines were used to validate if the effects of NGF on pancreatic cancer cell growth are dependent on the expression levels and the balance of TrkA and P75 receptors. NGFRs were found in all of the tumor specimens and cell lines. It appears that in pancreatic cancer cells the growth effects of NGF depend on the expression levels and the ratio of TrkA and p75NGFR. TrkA and p75NGFR negatively correlated and were both associated with abdominal or back pain and perineural invasion. Regarding this, high TrkA expression levels exhibited more frequent perineural invasion and a higher degree of pain, whereas the results of p75NGFR are on the contrary. For Cox univariate analyses in the OS study, high expression of p75NGFR was associated with longer overall survival yet TrkA exhibited opposite effects and included the effect of pain. HPG, tumor size, node involvement, and perineural invasion were not prognostic factors. In Cox multivariate analyses, TrkA and p75NGFR were both prognostic para-meters. In conclusion, our study found that the expression of TrkA in pancreatic cancer is a marker of tumor aggressiveness. Conversely, we also found that elevated p75NGFR expression is associated with a favorable prognosis; we demonstrated that NGF exerts both stimulatory and inhibitory effects on pancreatic cancers with the effect based on the expression levels and the ratio of TrkA and p75NGFR.

Pancreatic ductal adenocarcinoma (PDAC) is associated with significant morbidity and mortality. Morbidity in PDAC is partly due to the severe pain reported by patients with the disease. Tumor-nerve interactions including intrapancreatic perineural invasion, neurogenic inflammation, and neuritis are key features of pancreatic malignancies and are thought to play an important role in pancreatic cancer-related pain. Furthermore, neurotrophic factors such as nerve growth factor (NGF), glial cell line-derived neurotrophic factor (GDNF), GDNF family member artemin (Artn), and brain-derived neurotrophic factor (BDNF) have been implicated in the development of PDAC-related pain. These neurotrophic factors have been shown to produce hypersensitivity in sensory afferents and may drive the neuropathology underlying PDAC pain. Thus, we hypothesized that neurotrophic factors would be increased in the pancreas of PDAC mice as tumors develop, leading to altered pancreatic innervation and changes in pain-related behavior. Experiments were performed with transgenic mice that have pancreas-specific expression of a mutated Kras oncogene and heterozygous deletion of the p53 tumor suppressor gene (p48Cre; LSL-KRASG12D; p53lox/+). PDAC mice demonstrated a varied disease time course but generally developed multifocal pancreatic cancer by week 16 as evidenced by nodular-appearing pancreata. Obstruction of the biliary tree, tumor involvement throughout the mesentery, and metastases to the liver were also observed in some PDAC mice at more advanced stages of disease (> 25 weeks). Sex- and age-matched littermate transgenic controls were used for all experiments. Pancreas RNA was isolated from PDAC mice and controls at 16-30 weeks of age and levels of neurotrophic factor and neurotrophic factor receptor mRNA expression was measured using PCR and qRT-PCR. Indeed, expression of NGF, the NGF receptor TrkA, Artn, GDNF, the GDNF receptor GFRα1, BDNF, and the BDNF receptor TrkB were all increased in the pancreas of PDAC mice compared to controls. Immunohistochemical studies were performed to examine the density and distribution of nerve fibers in the pancreas of PDAC mice. Large nerve bundles that stained intensely with the pan-neuronal marker PGP 9.5, tyrosine hydroxylase (TH; NGF-responsive sympathetic fibers), calcitonin gene-related peptide (CGRP; sensory fibers), and growth-associated protein 43 (GAP-43; nerve sprouting) were observed in the pancreas of PDAC mice but not controls. Open-field, exploratory behavior was monitored in PDAC mice between 16 30 weeks of age. Specifically, animals were placed in Plexiglas boxes and their activity in both the horizontal plane and vertical plane was measured photoelectrically for a period of 15 minutes. PDAC mice spent less time moving horizontally and vertically, had a reduced number of reaching movements into the vertical plane, traveled less distance in the vertical plane, and made fewer movements in the vertical plane. These data indicate that significant changes in pancreatic innervation and neurotrophic factor expression occur in a transgenic mouse model of pancreatic cancer and these changes correlate with pain-related decreases in ambulatory and reaching activity. Thus, this animal model will enable us to systematically study the impact of neuroplastic changes in the PDAC microenvironment on the development of pancreatic cancer-related pain. This proffered talk is also presented as Poster A81. Citation Format: Rachelle E. Stopczynski, Kathryn M. Albers, Klaus Bielefeldt, Ronald A. DePinho, Haoqiang Ying, Brian M. Davis. Neuroplastic changes and pain-related behavior in a transgenic mouse model of pancreatic ductal adenocarcinoma (PDAC). [abstract]. In: Proceedings of the AACR Special Conference on Pancreatic Cancer: Progress and Challenges; Jun 18-21, 2012; Lake Tahoe, NV. Philadelphia (PA): AACR; Cancer Res 2012;72(12 Suppl):Abstract nr PR4.

Objective To study tyrosine kinase B (TrkB) and brain-derived neurotrophic factor (BDNF) expression in cervical carcinoma tissue, paracancerous tissues and normal cervical tissue, analyze their relationship with clinical pathological characteristics of cervical cancer, and to investigate the relation between apoptosis signal pathway activation around cancer cells and tumor malignancy. Methods A total of 72 cases with cervical invasive carcinoma were selected, while 72 cases of normal cervical tissues were selected as control group. Tissue microarrays of cervical cancer tissues, adjacent tissues and normal cervical tissues were made and the expressions of TrkB and BDNF were detected and compared by immunohistochemistry method. Results A total of 6 tissue chips were constructed. Expression rates of TrkB and BDNF in cervical cancer were 70.80% and 91.70%, respectively, and were significantly higher than those in paracancerous tissue (25.00% and 48.60% ). There was almost no expression in normal cervical tissue, of which the positive rates were 4.20% and 1.40%. The positive rate of TrkB in cervical cancer was related to vascular invasion and lymph node metastasis (χ2=12.50 and 12.36, P 0.05). Meanwhile, the total positive rate of BDNF was high, and had no correlation with all factors above (P all>0.05). The expressions of TrkB and BDNF in cancer adjacent tissue were related to the tumor diameter, vascular invasion and lymph node metastasis (P<0.01 or P<0.05). Conclusions There are some TrkB and BDNF expressions in the cervical cancer adjacent tissues. The expression levels in paracancerous tissues are significantly correlated with tumor diameter, vascular invasion and lymph node metastasis, and show better reflection of the malignant degree than those in tumor tissues. The expressions of TrkB and BDNF in paracancerous tissues may be used as new biological markers for evaluating the prognosis of patients with cervical cancer. Key words: Uterine cervical neoplasms; Tyrosine kinase B; Brain-derived neurotrophic factor; Paracancerous tissues; Apoptosis

Cell Survival through Trk Neurotrophin Receptors Is Differentially Regulated by Ubiquitination

Plasma brain-derived neurotrophic factor in women after bariatric surgery: a pilot study

Krüppel-Like Factor 10 Expression as a Prognostic Indicator for Pancreatic Adenocarcinoma

Objective To investigate the effect of cancer drug sensitivity on the selection of chemotherapy for pancreatic cancer. Methods The cells from the cancer tissues of 156 pancreatic cancer patients were cultured with 6 kinds of chemotherapy drugs in vitro including gemcitabine (GEM), 5 fluorouracil (5-FU), Mitomycin C (MMC), Oxaliplatin (L-OHP) and irrinotecan (CPT-11), according to the in vitro standard of solitary tumor. More than 70% of inhibitory rate was highly sensitive, 50% ～ 70% was moderately sensitive, ＜ 50% was insensitive. The inhibitory rate of chemotherapy drugs were determined by MTT colorimetric assay. Results The pathological findings of the 156 cases of pancreatic cancer were pancreatic duct cancer in 135 cases, adenosquamous carcinoma in 13 cases, mucinous carcinoma in 8 cases.Pancreatic duct cancer was sensitive to all the 6 drugs; adenosquamous carcinoma and mucinous carcinoma was sensitive to all the drugs except for L-OHP and CPT-11, respectively. The inhibitory rate of GEM was higher than that of MMC, L-OHP and CPT-11 (P ＜ 0.05 ) , but there was no difference with 5-FU and DDP ( P ＞0.05 ). There was no difference among the other 5 drugs (P ＞ 0.05 ). However, the cells from different types of pancreatic cancers and the cells from different patients of the same type of pancreatic cancer have different sequence of sensitivity to the 6 kinds of chemotherapy drugs. For pancreatic duct cancer, the sequence of sensitivity was GEM ＞ DDP ＞ 5-FU ＞ CPT-11 ＞ MMC ＞ L-OHP; adenosquamous carcinoma was GEM, CPT-11 ＞ DDP, 5-FU, MMC ＞ L-OHP; mucinous carcinoma was L-OHP ＞ GEM ＞5-FU, MMC ＞ DDP ＞ CPT-11.Conclusions Cancer drug sensitivity test may help to select the fight chemotherapy and be of clinical value. Key words: Pancreatic neoplasms; Colorimetry; Drug monitoring; Chemotherapy

Changes in plasma müllerian-inhibiting substance and brain-derived neurotrophic factor after chemotherapy in premenopausal women

Other risk factors for pancreatic cancer: Hormonal aspects

Brain-derived neurotrophic factor is the ligands of tyrosine kinase receptor B,for the binding of brain-derived neurotrophic factor to tyrosine kinase receptor B receptor,signal transmitted to the nucleus,resulting in a variety of biological effects.Lots of researchs had found that brain-derived neurotrophic factor and tyrosine kinase receptor B expression in malignant tumors more than non-cancerous adjacent tissue and normal tissue,and their effect can promote tumor blood vessel formation,suppress of cell anoikis,promote tumor growth,differentiation and metastasis.The relationship of brain-derived neurotrophic factor and tyrosine kinase receptor B provide a new therapeutic strategy for clinical treatment.From the current basic and clinical research,this treatment strategy has great prospect. Key words: Brain-derived neurotrophic factor; Receptor,TrkB; Neoplasms; Therapy

Perineural invasion (PNI) is a typical feature of pancreatic ductal adenocarcinoma (PDAC), which occurs in most cases. The embryonic protein Nodal plays a critical role in embryonic neural development and is overexpressed in human pancreatic cancer. In this study, we explored the contribution of Nodal to pancreatic cancer PNI and progression. We evaluated the function of Nodal in PNI by coculturing rat dorsal root ganglia and pancreatic cancer cells in vitro and performing cellular and molecular biology assays. The results illustrate that Nodal upregulates NGF (nerve growth factor), BDNF (brain-derived neurotrophic factor), and GDNF (glial cell line-derived neurotrophic factor) expression in pancreatic cancer cells and promotes cancer cell migration/invasion. Furthermore, in the in vitro 3D PNI model, Nodal enhances nerve outgrowth to pancreatic cancer cell colonies. Our study indicates that Nodal participates in tumor invasion by mediating neural and tumor cell signaling interactions, and inhibiting the expression of Nodal represents a potential strategy for targeting PNI in pancreatic cancer therapy.

Trick or treat? Does cancer fool Schwann cells by mimicking axons to promote metastasis into nerves?

Objective To investigate the expressions of tyrosine kinase receptor (Trk)B and brain-derived neurotrophic factor (BDNF) protein in human gastric careinoma and compare them with those in epithelial cells of normal mucous, in order to evaluate their clinicopathological significance. Method The expressions of TrkB and BDNF protein in tumor tissues, matched with para-tumor mueosal tissues from 64 cases with gastric carcinoma and normal mucous of 20 cases were observed immunohistochemically and related to some of the clinicopathological parameters. Results The positive rates of TrkB and BDNF protein in tumor tissues were 60.9% and 59.4% respectively, but there was negative in matched para-tumor mueosal tissues and normal mucosal tissues. TrkB and BDNF protein expressions were related to invasive depth,lymph node metastasis and TNM stage of cancer, but not to sex, age and degrees of cancerous differentiation.The positive rates of TrkB and BDNF protein in cases with serosal infiltration, lymph node metastasis and TNM stage Ⅲ - Ⅳ were significantly higher than those in cases without serosal infiltration, lymph node metas-tasis, and TNM stage Ⅰ - Ⅱ (P 0.05 ). Conclusions The expressions of TrkB and BDNF protein are closely relatedto tumorigenesis and progression of gastric carcinoma. The increased expression of TrkB and BDNF may promote the occurrance of local invasion and metastasis of gastric carcinoma. Key words: Stomach neoplasms; Neoplasm metastasis; Immunohistochemistry; Receptor pro-tein-tyrosine kinases; Brain-derived neurotrophic factor