Angiogenesis and tumor proliferation/metastasis of human colorectal cancer cell line SW620 transfected with endocrine glands-derived-vascular endothelial growth factor, as a new angiogenic factor

Anti-Prokineticin1 Suppresses Liver Metastatic Tumors in a Mouse Model of Colorectal Cancer with Liver Metastasis

Multidisciplinary treatment for colorectal cancer (CRC) has undergone significant advances, and molecularly targeted drugs have substantially improved patient prognosis. However, one problem with current molecularly targeted therapeutics is that they must be used in combination with anticancer agents. New molecular targeted therapies that can be used alone are needed. We have previously identified prokineticin1 (PROK1) factor as a therapeutic potential target for CRC. PROK1 factor is involved in the angiogenesis of tissues surrounding CRC tumors. Additionally, PROK1 receptors 1 and 2 are expressed in CRC cell lines, playing roles in cell proliferation via an autocrine mechanism and in the signaling system. In this study, a liver metastasis mouse model was developed using human colorectal cancer cell lines, and mice were divided into anti-PROK1 antibody administration and control groups. Mice were treated intraperitoneally with antibodies or phosphate-buffered saline (control) every three days. The number, size, and cell proliferation ability of metastatic lesions were analyzed. Our results suggested that the number, size, and cancer cell proliferation ability of metastatic lesions decreased, and the survival time significantly increased in the antibody-treated group compared to those in the control group. Thus, the anti-PROK1 antibody therapy suppressed the cell proliferation ability of liver metastatic lesions in a CRC mouse model, suggesting its potential as a novel treatment strategy.

Angiogenic factors as prognostic markers in neuroendocrine neoplasms

PURPOSE

Angiogenic markers in neuroendocrine neoplasms (NENs) have recently received increasing attention, but their clinical role remains unclear. The aim of this study was to evaluate the role of angiogenic markers in NEN aggressiveness and prognosis.

METHODS

We performed a prospective observational study including 46 consecutive patients with proven NENs of pulmonary (45.65%) and gastro-entero-pancreatic (GEP) (54.35%) origin and 29 healthy controls. Circulating pro-angiogenic factors were measured by ELISA assay. ANG2 tissue expression was evaluated in a subgroup of ten patients by immunohistochemistry.

RESULTS

The study demonstrated a significantly higher level of ANG2, ANG1, sTIE2, and PROK2 in patients affected by NENs compared to controls. In the NENs' group we measured that: (i) ANG2 levels were higher in poorly vs well-differentiated NENs: 4.85 (2.75-7.42) vs 3.16 (1.66-6.36) ng/ml, p = 0.046 and in tumor stage 3-4 compared to stage 1-2: 4.24 (2.66-8.72) vs 2.73 (1.53-5.70), p = 0.044; (ii) ANG2 and PROK2 were significantly higher in patents with progressive disease compared to stable disease: ANG2 = 6.26 (3.98-10.99) vs 2.73 (1.65-4.36) pg/ml, p = 0.001; PROK2 = 29.19 (28.42-32.25) vs 28.37 (28.14-28.91) pg/ml, p = 0.035. Immunohistochemistry confirmed ANG2 expression in tumor specimens.

CONCLUSIONS

We documented higher levels of angiogenic markers in NENs, with an association between ANG2 serum levels and NENs morphology and staging. In both GEP and lung NENs, ANG2 and PROK2 are higher in case of tumor progression, suggesting a potential role as prognostic markers in NENs patients.

Prokineticin-1 induces normal lymphangiogenic activity and is involved in lymphangiogenesis and lymph node metastasis in colorectal cancer

Background: Prokineticin family correlates with important roles in several biological processes, including homeostasis. We discovered novel functions of prokineticin1 (PROK1) in lymphangiogenesis and lymphnode metastasis in colorectal cancer.

Materials and Methods: We examined changes in the number of lymphatic endothelial cells after PROK1 stimulation. PROK1 protein was stimulated with subcutaneously implanted in mice. Also a high-PROK1-expressing colorectal cancer cell line and anti-PROK1 antibody(Ab) were subcutaneously implanted in mice, and then examine lymphangiogenesis. PROK1 expression and the number of lymph vessels were examined in the primary lesion of 391 patients whose colorectal tumors had been resected.

Results: When PROK1 was used as a stimulus, the number of lymphatic cells increased compared to unstimulated cells. And the number of lymph vessels in the skin of mice increased compared to mice implanted without PROK1. The number of lymph vessels in the primary tumor tissue increased when PROK1 was highly expressed compared to cases with non-detectable PROK1 expression. When PROK1 was expressed in human colorectal tumors, the rate of lymphnode metastasis was significantly higher than that in cases with non-detectable PROK1 expression.

Conclusions: PROK1 is a lymphangiogenic factor involved in the formation of new lymph vessels and lymphnode metastasis in human colorectal cancer.

Angiogenesis-promoting factors in colorectal cancer

Colorectal cancer (CRC) is one of the common malignant tumors, accounting for about 10% and 9.4% of malignancies in males and females, respectively. The number of patients who die from CRC reaches 700000 each year. In addition, there are about 1.4 million new patients every year. Angiogenesis is involved in a variety of physiological and pathological processes and is an important pathological marker for many diseases such as tumor, ischemia, atherosclerosis, inflammation, wound healing, and tissue regeneration. Angiogenesis plays a crucial role in the occurrence, development, and metastasis of CRC. In this review, we summarize our current knowledge of tumor-associated angiogenesis, the factors that promote angiogenesis in CRC, and future directions in this field, with an aim to provide a theoretical basis for better understanding the role of angiogenesis in the pathogenesis of CRC.

VEGF, VEGF165b and EG-VEGF expression is specifically related with hormone profile in pituitary adenomas

Vascular endothelial growth factor (VEGF), its inhibitory splice variant, VEGF165b and Endocrine Gland derived VEGF (EG-VEGF) have a controversial role in pituitary gland. We aim to study VEGF, VEGF165b and EG-VEGF expression in pituitary adenomas. A significant correlation was found between growth hormone (GH) and VEGF secretion (P=0.024). For prolactinomas, VEGF and prolactin expression, had a P-value of 0.02 for Kendall coefficient and a P-value of 0.043 for the Spearman coefficient. VEGFmRNA amplification was detected in both tumor cells and folliculostellate cells. VEGF165b was positive in 16.66% of pituitary adenomas. EG-VEGF was significantly correlated with prolactin (P=0.025) and luteinizing hormone (P=0.028). Our data strongly support VEGF, VEGF165b and EG-VEGF as important players of pituitary adenomas tumorigenesis. Particular hormonal milieu heterogeneity, special vascular network with an unusual reactivity to tumor growth correlated with variability of VEGF, VEGF165b and EG-VEGF secretion may stratify pituitary adenomas in several molecular groups with a direct impact on therapy and prognosis.

SOX5 induces lung adenocarcinoma angiogenesis by inducing the expression of VEGF through STAT3 signaling

Background and objectives

Angiogenesis is the main cause of lung adenocarcinoma (LAC) poor prognosis. This study aimed to investigate the effect of sex-determining region Y-box protein 5 (SOX5) expression on angiogenesis of LAC and explore its possible mechanism.

Patients and methods

The effect on angiogenesis was tested by tube formation assays using human umbilical vein endothelial cells cocultured with A549 cells. Lentivirus shRNA of SOX5 and lentivirus of SOX5 overexpression system were used to establish LAC cell lines, which expressed SOX5 of different levels. SOX5 downstream signaling targets were analyzed by real-time qPCR and Western blot. We collected 90 LAC cases and the tissues were examined by immunohistochemistry for SOX5 and vascular endothelial growth factor (VEGF).

Results

We found that SOX5 overexpression in A549 cells significantly promoted tube formation capacity of the cocultured human umbilical vein endothelial cells. SOX5 increased VEGF expression and signal transducer activator of transcription 3 phosphorylation; however, SOX5 had no effect on extracellular signal-regulated kinase and protein kinase B pathway. Furthermore, the expression of SOX5 and VEGF had a significantly positive correlation (r=0.399, P=0.001) according to the tissue microarray data.

Conclusion

These findings suggest that SOX5 induces angiogenesis by activating signal transducer activator of transcription 3/VEGF signaling and confer its candidacy as a potential therapeutic target in LAC.

A New Role for Helicobacter pylori Urease: Contributions to Angiogenesis

Helicobacter pylori is a pathogen involved in gastric diseases such as ulcers and carcinomas. H. pylori's urease is an important virulence factor produced in large amounts by this bacterium. In previous studies, we have shown that this protein is able to activate several cell types like neutrophils, monocytes, platelets, endothelial cells, and gastric epithelial cells. Angiogenesis is a physiological process implicated in growth, invasion and metastization of tumors. Here, we have analyzed the angiogenic potential of H. pylori urease (HPU) in gastric epithelial cells. No cytotoxicity was observed in AGS, Kato-III, and MKN28 gastric cell lines treated with 300 nM HPU, as evaluated by the 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. As we previously reported in neutrophils, treatment with 300 nM HPU also had an anti-apoptotic effect in gastric epithelial cells leading to a 2.2-fold increase in the levels of Bcl-X_L after 6 h, and a decrease of 80% in the content of BAD, after 48 h, two mitochondrial proteins involved in regulation of apoptosis. Within 10 min of exposure, HPU is rapidly internalized by gastric epithelial cells. Treatment of the gastric cells with methyl-β-cyclodextrin abolished HPU internalization suggesting a cholesterol-dependent process. HPU induces the expression of pro-angiogenic factors and the decrease of expression of anti-angiogenic factors by AGS cells. The angiogenic activity of HPU was analyzed using in vitro and in vivo models. HPU induced formation of tube-like structures by human umbilical vascular endothelial cells in a 9 h experiment. In the chicken embryo chorioallantoic membrane model, HPU induced intense neo-vascularization after 3 days. In conclusion, our results indicate that besides allowing bacterial colonization of the gastric mucosa, H. pylori's urease triggers processes that initiate pro-angiogenic responses in different cellular models. Thus, this bacterial urease, a major virulence factor, may also play a role in gastric carcinoma development.

Antagonism of EG-VEGF Receptors as Targeted Therapy for Choriocarcinoma Progression In Vitro and In Vivo

Purpose: Choriocarcinoma (CC) is the most malignant gestational trophoblastic disease that often develops from complete hydatidiform moles (CHM). Neither the mechanism of CC development nor its progression is yet characterized. We recently identified endocrine gland-derived vascular endothelial growth factor (EG-VEGF) as a novel key placental growth factor that controls trophoblast proliferation and invasion. EG-VEGF acts via two receptors, PROKR1 and PROKR2. Here, we demonstrate that EG-VEGF receptors can be targeted for CC therapy.Experimental Design: Three approaches were used: (i) a clinical investigation comparing circulating EG-VEGF in control (n = 20) and in distinctive CHM (n = 38) and CC (n = 9) cohorts, (ii) an in vitro study investigating EG-VEGF effects on the CC cell line JEG3, and (iii) an in vivo study including the development of a novel CC mouse model, through a direct injection of JEG3-luciferase into the placenta of gravid SCID-mice.Results: Both placental and circulating EG-VEGF levels were increased in CHM and CC (×5) patients. EG-VEGF increased JEG3 proliferation, migration, and invasion in two-dimensional (2D) and three-dimensional (3D) culture systems. JEG3 injection in the placenta caused CC development with large metastases compared with their injection into the uterine horn. Treatment of the animal model with EG-VEGF receptor's antagonists significantly reduced tumor development and progression and preserved pregnancy. Antibody-array and immunohistological analyses further deciphered the mechanism of the antagonist's actions.Conclusions: Our work describes a novel preclinical animal model of CC and presents evidence that EG-VEGF receptors can be targeted for CC therapy. This may provide safe and less toxic therapeutic options compared with the currently used multi-agent chemotherapies. Clin Cancer Res; 23(22); 7130-40. ©2017 AACR.

Endocrine Gland-Derived Vascular Endothelial Growth Factor/Prokineticin-1 in Cancer Development and Tumor Angiogenesis

A lot of data suggests endocrine gland-derived vascular endothelial growth factor (EG-VEGF) to be restricted to endocrine glands and to some endocrine-dependent organs. Many evidences show that EG-VEGF stimulates angiogenesis and cell proliferation, although it is not a member of the VEGF family. At the time, a lot of data regarding the role of this growth factor in normal development are available. However, controversial results have been published in the case of pathological conditions and particularly in malignant tumors. Thus, our present paper has been focused on the role of EG-VEGF in normal tissues and various malignant tumors and their angiogenic processes.

Expression of prokineticin-receptor2(PK-R2) is a new prognostic factor in human colorectal cancer

The increased invasiveness of colorectal cancer cells is important for progression and metastasis to the surrounding organs. According to recent molecular biological studies, signaling through transmembrane Prokineticin-Receptor2(PK-R2) is likely involved in the ability of tumor cell to invade. However, no studies have evaluated the relationship between PK-R2 expression, ability of cancer to invade/metastasize, and patient prognosis in cases of resected colorectal cancer. Accordingly, we have examined these factors in the present study.

Immunohistochemical staining was performed to detect PK-R2 in the primary lesion and adjacent normal large intestine mucosa of 324 colorectal cancer patients who underwent resection surgery at our department. Additionally, we conducted clinicopathologic examinations and analyzed patient prognoses with the Kaplan-Meier method. Further, multivariate analysis was conducted using a cox-proportional hazard model.

PK-R2 expression was observed on the cellular membrane of the primary lesion in 147 of 324 cases (45.3%) of human colorectal cancer. PK-R2 expression was associated with a higher incidence of vascular invasion, lymph node metastasis, hepatic metastasis, and hematogenous metastasis. Further, prevalence of PK-R2 expression increased as tumor stage increased. In stage III curative resection cases, where recurrence is the most serious problem, cases that expressed PK-R2 had a significantly lower 5-year survival rate (82.1% versus 66.8%) and higher recurrence compared to those cases with no PK-R2 expression. In the multivariate analysis for prognosis, PK-R2 expression was found to be an independent factor(ratio2.621).

PK-R2 expression could be one of the new prognostic factors in human colorectal cancer.

Role of Endocrine Gland-Derived Vascular Endothelial Growth Factor (EG-VEGF) and Its Receptors in Adrenocortical Tumors

Angiogenesis is essential for tumor growth and metastasis. Endocrine gland-derived vascular endothelial growth factor (EG-VEGF) is an angiogenic factor predominantly expressed in steroidogenic organs like the adrenal gland, ovary, testes, and placenta. EG-VEGF has antiapoptotic, mitogenic, and chemoattractive properties mediated via the two G protein-coupled receptors prokineticin receptor 1 (PKR1) and prokineticin receptor 2 (PKR2). We investigated the expression of EG-VEGF and its receptors in a large number of normal adrenal glands (NAG), adrenocortical adenomas (ACA), and carcinomas (ACC) using real-time PCR (NAG, n = 12; ACA, n = 24; and ACC, n = 30) and immunohistochemistry (NAG, n = 9; ACA, n = 23; and ACC, n = 163) and evaluated its impact on patients’ survival. EG-VEGF, PKR1, and PKR2 mRNA and protein are expressed in NAG and the vast majority of ACA and ACC samples. The mean EG-VEGF mRNA expression was significantly lower in ACC (606.5 ± 77.1 copies) compared to NAG (4,043 ± 1,111) and cortisol-producing adenomas (CPA) (4,433 ± 2,378) (p < 0.01 and p < 0.05, respectively). However, cytoplasmic and nuclear EG-VEGF protein expression was either significantly higher or similar in ACC (H score 2.4 ± 0.05, p < 0.05 and 1.7 ± 0.08, n.s., respectively) compared to NAG (1.8 ± 0.14 and 1.7 ± 0.2). Nuclear protein expression of either EG-VEGF or PKR1 or both is predictive for a higher mortality compared to patients without nuclear expression (hazard ratio (HR) = 5.15; 95 % confidence interval (CI) = 1.24–21.36, n = 100, p = 0.02 independent of age, sex, and tumor stage). These findings suggest that EG-VEGF and its receptor PKR1 might play a role in the pathogenesis of adrenocortical tumors and could serve as prognostic markers for this rare malignant disease.

The prognosis was poorer in colorectal cancers that expressed both VEGF and PROK1 (No correlation coefficient between VEGF and PROK1)

The angiogenic proteins vascular endothelial growth factor (VEGF) and prokineticin1 (PROK1) proteins are considered important in colorectal cancer, the relationship between their simultaneous expression and prognosis was investigated in the present study.

VEGF and PROK1 expression in 620 primary human colorectal cancer lesions was confirmed via immunohistochemical staining with anti-VEGF and anti-PROK1 antibodies, and the correlation between the expression of these 2 proteins and recurrence/prognosis were investigated.

VEGF protein was expressed in 329 (53.1%) and PROK1 protein was expressed in 223 (36.0%). PROK1 and VEGF were simultaneously expressed in 116 (18.7%) of the 620 cases. The correlation coefficient between VEGF expression and PROK1 expression was r = 0.11, and therefore correlation was not observed. Clinical pathology revealed that substantially lymphnode matastasis, hematogenous metastasis, or TMN advanced-stageIV was significantly more prevalent in cases that expressed both VEGF and PROK1 than in the cases negative for both proteins or those positive for only 1 of the proteins.

Also the cases positive for both proteins exhibited the worst recurrence and prognosis. In the Cox proportional hazards model, VEGF and PROK1 expression was an independent prognostic factor.

The prognosis was poorer in colorectal cancers that expressed both PROK1 and VEGF relative to the cases that expressed only 1 protein, and the expression of both proteins was found to be an independent prognostic factor.

Prokineticin 2 (PROK2) is an important factor for angiogenesis in colorectal cancer

The Prokineticin 2 (PROK2) is correlated with indispensable in maintaining the homeostasis of healthy human tissues. Herein, we examined the role of PROK2 in human colorectal cancer.

After total RNA extraction from 6 colorectal cancer cell lines, we examined the expression of PROK2 mRNA. For investigating angiogenesis and tumor growth in mice, the PROK2 gene was transfected into colorectal cancer cell lines having low PROK2 mRNA expression. In addition, small interfering RNA (siRNA) was transfected into colorectal cancer cell lines having high PROK2 mRNA expression for investigation of angiogenesis and tumor growth in mice.

From 6 colorectal cancer cell lines studied, PROK2 mRNA expression was increased in 3 cell lines. When the PROK2 gene was transfected into the colorectal cancer cell line with low PROK2 mRNA expression, angiogenesis and tumor growth in mice increased significantly compared to the cell line with the control vector.

When PROK2 siRNA was transfected into colorectal cancer cell lines with high PROK2 mRNA expression, angiogenesis and tumor growth in mice were suppressed significantly compared to the cell line with siRNA (control).

This is the first report of the association of PROK2 as an angiogenic growth factor in colorectal cancer.

Iron induces cancer stem cells and aggressive phenotypes in human lung cancer cells

Evidence has accumulated in support of the critical impact of cancer stem cells (CSCs) behind the chemotherapeutic failure, cancer metastasis, and subsequent disease recurrence and relapse, but knowledge of how CSCs are regulated is still limited. Redox status of the cells has been shown to dramatically influence cell signaling and CSC-like aggressive behaviors. Here, we investigated how subtoxic concentrations of iron, which have been found to specifically induce cellular hydroxyl radical, affected CSC-like subpopulations of human non-small cell lung carcinoma (NSCLC). We reveal for the first time that subchronic iron exposure and higher levels of hydroxyl radical correlated well with increased CSC-like phenotypes. The iron-exposed NSCLC H460 and H292 cells exhibited a remarkable increase in propensities to form CSC spheroids and to proliferate, migrate, and invade in parallel with an increase in level of a well-known CSC marker, ABCG2. We further observed that such phenotypic changes induced by iron were not related to an epithelial-to-mesenchymal transition (EMT). Instead, the sex-determining region Y (SRY)-box 9 protein (SOX9) was substantially linked to iron treatment and hydroxyl radical level. Using gene manipulations, including ectopic SOX9 overexpression and SOX9 short hairpin RNA knockdown, we have verified that SOX9 is responsible for CSC enrichment mediated by iron. These findings indicate a novel role of iron via hydroxyl radical in CSC regulation and its importance in aggressive cancer behaviors and likely metastasis through SOX9 upregulation.

The anti-tumor effect is enhanced by simultaneously targeting VEGF and PROK1 in colorectal cancer

Hematogenous metastasis, mainly hepatic metastasis, is a frequent metastatic mode in colorectal cancer involving angiogenic growth factors. Two angiogenic growth factors, in particular, Vascular endothelial growth factor (VEGF) and Prokineticin1(PROK1), are considered to have an important role in hematogenous metastasis of colorectal cancer. Accordingly, we report our findings on the importance of the anti-tumor efffect by inhibiting these two factors in human colorectal cancer.When the culture fluid of Colorectal cancer cell lines(DLD-1, HCT116, and LoVo) with high levels of VEGF/PROK1 expression was injected subcutaneously into mice, the culture fluid increased subcutaneous angiogenesis. But when both anti-PROK1 and anti-VEGF antibodies were present in the culture fluid, the length and size of the blood vessels were reduced compared with those seen in the fluid-only, anti-PROK1, and anti-VEGF controls. Also, tumor masses were produced in mice by subcutaneously embedding colorectal cancer cells with high levels VEGF/PROK1 expression. When both anti-PROK1 and anti-VEGF antibodies were simultaneously applied, tumor formation and peritumoral angiogenesis were strongly suppressed, compared with when either anti-PROK1 antibody or anti-VEGF antibody was applied alone.Simultaneous targeting of both angiogenic growth factors (VEGF/PROK1) may prove more useful in colorectal cancer.

Prokineticin 1 protein expression is a useful new prognostic factor for human sporadic colorectal cancer

BACKGROUND

Hematogenous metastasis, regarded as closely related to angiogenic growth factors, is associated with colorectal cancer prognosis. The angiogenic growth factor prokineticin 1 (PROK1) has been cloned from endocrine cells. However, its protein expression in human malignant tumors has not been studied. The current study established the anti-PROK1 monoclonal antibody (mAb) and examined the relationship between the expression of PROK1 protein and human colorectal cancer.

METHODS

The expression of PROK1 protein was assessed in 620 resected sporadic colorectal cancer tissue samples by immunohistochemical staining with in-house-developed human PROK1 mAb to investigate the relationship of PROK1 expression to clinicopathologic factors, recurrence, and survival rate and to evaluate its prognostic significance.

RESULTS

The expression of PROK1 protein was detected in 36 % (223/620) of human primary colorectal cancer lesions but no in the healthy mucosa adjacent to the colorectal cancer lesions. According to the clinicopathologic examinations, the frequency of positive PROK1 expression was significantly higher in cases with serosal invasion, lymphatic invasion, venous invasion, lymph node metastasis, liver metastasis, hematogenous metastasis, and higher stage disease. The recurrence rate and prognosis for patients with PROK1 expression-positive lesions were significantly worse. In the Cox proportional hazard model, PROK1 expression was an independent prognostic factor.

CONCLUSIONS

The expression of PROK1 protein was identified for the first time as a new prognostic factor in colorectal cancer.

Anti-prokineticin1 (PROK1) monoclonal antibody suppresses angiogenesis and tumor growth in colorectal cancer

BACKGROUND

The prokineticin1 (PROK1) gene has been cloned as an angiogenic growth factor from endocrine gland cells. However, we have not known about potentials of anti-PROK1 monoclonal antibody in human cancers. Here we investigated how the anti-PROK1 monoclonal antibody (mAb; established by our department) would affect the high-PROK1-expressing colorectal cancer (CRC) cells in vitro and vivo.

METHODS

We confirmed PROK1 protein expression in the CRC cells by performing immunohistochemical staining and measured the amount of soluble PROK1 protein. Next, we mixed the CRC cell culture fluid with the anti-PROK1mAb to examine angiogenic activity in vitro and in vivo. Additionally, we investigated whether the anti-PROK1mAb would affect the tumor-forming capability of high PROK1-expressing CRC cells implanted into mice.

RESULTS

PROK1 protein expression was confirmed in 3 CRC cell lines, and soluble PROK1 protein was also confirmed in the CRC cell culture fluid. The culture fluid increased angiogenesis in vitro and vivo, whereas the anti-PROK1mAb suppressed angiogenesis. Subcutaneous tumor formation and tumor angiogenesis in mice were suppressed by the anti-PROK1mAb treatment. The anti-PROK1mAb significantly suppressed the number of CD31 stained cells in mice.

CONCLUSIONS

The in vitro and vivo experimental system indicated that the anti-PROK1mAb could suppress angiogenesis and tumor growth in the CRC strains.

CD44variant exon 9 plays an important role in colon cancer initiating cells

Cancer stem cells(cancer initiating cells) have become increasingly important in the treatment of malignant tumors. CD44 in particular has been identified as a marker for stem cells in colon cancer, which is a high-morbidity tumor. However, many details remain unknown, including identification of the relevant exon. The elucidation of these details could lead to the development of new therapies and improvements in prognosis. We report our findings on the importance of CD44 variant exon 9(v9) of stem cells in colon cancer.

Using the anti-CD44 standard form(s) antibody, as well as antibodies for each of the CD44 variant exons, we studied colon cancer cell lines by examining stained images of stem cells in the crypt of normal colon mucosa. Using the anti-CD44v9 antibody that fits the normal colon mucosa stem cells, we screened cells using flow cytometry to examine colony formation, resistance to anticancer drugs, and tumor mass formation after subcutaneous implantation in mice.

The stem cell–containing region in the crypt of normal colon mucosa was negative for anti-Ki67 antibody staining; only the anti-CD44 v9 antibody stain was expressed. As for colony formation, resistance to anticancer drugs, and tumor mass formation, cells positive both for anti-CD44s and anti-CD44v9 antibody stains was significantly more frequent than those positive for anti-CD44s antibody stain and negative for anti-CD44v9 antibody stain and those negative both for anti-CD44s and anti-CD44v9 antibody stains.

CD44 variant exon 9 plays an important role in colon cancer stem cells.

Polysaccharide K suppresses angiogenesis in colon cancer cells

The protein-bound polysaccharide K (PSK) is used as a non-specific immunotherapeutic agent for the treatment of colon cancer. Little research, however, has been conducted on its association with angiogenesis, which is a prognostic factor markedly correlated with hematogenous metastases. We therefore decided to investigate the action of PSK on angiogenic growth factors, angiogenesis inhibitors and angiogenesis in colon cancer cells. Reverse transcription-polymerase chain reaction (RT-PCR) was used to investigate changes in HIF-1α mRNA expression. PCR array was used to investigate changes in angiogenic growth factors and angiogenesis inhibitors, as well as the expression of related genes. Colon cancer cells were cultured with or without PSK for 48 h. The following day, cells were cultured for two days at 37°C in new complete media. The resulting culture medium was placed in the chamber of a tube formation system in order to investigate tube formation. Investigation of HIF-1α mRNA expression in colon cancer cell lines and in cells cultured under identical conditions with added PSK revealed a significant decrease in expression, as well as a decrease in angiogenic growth factors and related genes in PSK-treated colon cancer cell lines. By contrast, levels of angiogenesis inhibitors and related genes were higher in the PSK-treated colon cancer cell lines. Investigation of tube formation revealed that elongation was inhibited in the medium of the PSK-treated colon cancer cell lines in comparison to the medium of the non-treated colon cancer cell lines. PSK suppresses angiogenic growth factors and related genes, enhances angiogenesis inhibitors and related genes and ultimately suppresses angiogenesis in colon cancer cells.

Evidence of the importance of the first intracellular loop of prokineticin receptor 2 in receptor function

Prokineticin receptors (PROKR) are G protein-coupled receptors (GPCR) that regulate diverse biological processes, including olfactory bulb neurogenesis and GnRH neuronal migration. Mutations in PROKR2 have been described in patients with varying degrees of GnRH deficiency and are located in diverse functional domains of the receptor. Our goal was to determine whether variants in the first intracellular loop (ICL1) of PROKR2 (R80C, R85C, and R85H) identified in patients with hypogonadotropic hypogonadism interfere with receptor function and to elucidate the mechanisms of these effects. Because of structural homology among GPCR, clarification of the role of ICL1 in PROKR2 activity may contribute to a better understanding of this domain across other GPCR. The effects of the ICL1 PROKR2 mutations on activation of signal transduction pathways, ligand binding, and receptor expression were evaluated. Our results indicated that the R85C and R85H PROKR2 mutations interfere only modestly with receptor function, whereas the R80C PROKR2 mutation leads to a marked reduction in receptor activity. Cotransfection of wild-type (WT) and R80C PROKR2 showed that the R80C mutant could exert a dominant negative effect on WT PROKR2 in vitro by interfering with WT receptor expression. In summary, we have shown the importance of Arg80 in ICL1 for PROKR2 expression and demonstrate that R80C PROKR2 exerts a dominant negative effect on WT PROKR2.

Upregulation of endocrine gland-derived vascular endothelial growth factor in papillary thyroid cancers displaying infiltrative patterns, lymph node metastases, and BRAF mutation

BACKGROUND

Endocrine gland-derived vascular endothelial growth factor (Prok1) and prokineticin 2 (Prok2) are involved in the organ-specific regulation of angiogenesis, which is a crucial step toward cancer progression in most tumors, including those of thyroid gland. The oncogene BRAF V600E mutation is associated with poor clinical outcome of papillary thyroid cancer (PTC) and can independently predict its recurrence.

DESIGN

Our hypothesis was that Prok1 and Prok2 expression levels associated with BRAF mutations can be prognostic factors for PTC outcome. Prok1 and Prok2 were examined in PTC, a cell line derived from a human PTC (designated FB-2), euthyroid multinodular goiter (MNG), Graves' disease (GD), and contralateral normal thyroid (NT) tissues from PTC cases. We evaluated BRAF mutation and its relationship with Prok1 expression pattern in PTC.

METHODS

We studied Prok1 and Prok2 mRNAs by real-time polymerase chain reaction and BRAF mutation by mutant allele-specific polymerase chain reaction amplification. Formalin-fixed, paraffin-embedded blocks of PTC and NT were used for the immunohistochemical determination of Prok1 using anti-endocrine gland vascular endothelial growth factor primary antibody.

RESULTS

Prok1 and Prok2 transcripts were both present in thyroid tissues, and Prok1 was differentially expressed in PTC compared to MNG, GD, and NT. Prok1 mRNA levels were very low in NT and MNG and significantly higher in PTC, FB-2, and GD (p<0.05). Prok1 protein was almost undetectable in NT but was highly expressed in all PTC samples having an infiltrative pattern of growth and lymph node metastases ( p<0.05). Further, the expression of Prok1 in PTC was associated with 60% of the samples being positive for the BRAF mutation ( p<0.05).

CONCLUSIONS

We found that Prok1 is significantly increased in PTC, and its expression in PTC is related to BRAF mutation. These results suggest that Prok1 could be a new useful marker for thyroid cancer progression. Prok1 therefore could also be a potential target for novel therapeutic strategies, although the lack of functional data suggests caution against generalization of this assumption

Prokineticin-1/endocrine gland-derived vascular endothelial growth factor is a survival factor for human multiple myeloma cells

Prokineticin-1 (PK1) has been identified as a mitogen-specific protein for the endothelium of steroidogenic glands. Here we report a novel function of PK1 in the regulation of multiple myeloma (MM) cells. PK1 activates multiple signals including mitogen-activated protein kinase (MAPK), PI3K-AKT, and Jak-STAT3, sphingosine kinase-1 (SPK1) in MM cells. Treatment of MM cells with PK1 causes a time- and dose-dependent phosphorylation of MAPK, AKT and STAT3 and upregulation of SPK1 expression and cellular activity. We also show that PK1 upregulates Mcl-1 expression in a time- and dose-dependent manner in human MM cell lines and in the cells of patients with MM. Pertussis toxin, a pan-PK1 receptor inhibitor, can block PK1-induced upregulation of Mcl-1, indicating it relates to a G-protein-coupled receptor. We also show that PK1 protects MM cells against apoptosis induced by starvation for fetal calf serum (FBS), or for FBS and IL-6. Taken together, PK1 activates multiple signaling pathways and, upregulates Mcl-1 expression, leading to proliferation and survival of MM cells.

Prokineticin receptors in cardiovascular function: foe or friend?

Prokineticins are small secreted bioactive peptides, comprising two classes: prokineticin-1 and prokineticin-2. They exert their biological activity by binding to two G-protein-coupled receptors: prokineticin receptor (PKR) 1 and 2. Recent data have demonstrated that PKR1 induces postnatal neovasculogenesis by activating adult epicardial-derived progenitor cell differentiation, whereas myocardial PRK2 signaling confers detrimental actions on cardiomyocytes, leading to dilated cardiomyopathy and release of an unknown paracrine factor to induce capillary fenestration and vascular leakage. The knowledge gained from these studies leads to a model in which PKR1 and PKR2 signaling exert opposing actions in heart physiology and pathophysiology and facilitate the discovery of specific agonists and antagonists targeting PKR1 and PKR2 for possible use in treatment of cardiovascular diseases.

Endocrine glands-derived vascular endothelial growth factor protects pancreatic cancer cells from apoptosis via upregulation of the myeloid cell leukemia-1 protein

Endocrine glands-derived vascular endothelial growth factor (EG-VEGF, also termed as Prok1)--a novel cytokine that selectively acts on the endothelial cells of endocrine glands--was recently reported to be involved in the regulation of tumor cell growth and survival. However, its roles in the regulation of pancreatic cancer progression remain unclear. In this report, we investigated the suppressive effects of EG-VEGF on pancreatic cancer cell apoptosis and the relevant mechanisms. By using reverse-transcriptase polymerase chain reaction (RT-PCR) we found that the Mia PaCa II cells of the pancreatic cancer cell line express the mRNAs of both EG-VEGF (Prok1) and its receptors. EG-VEGF protects pancreatic cancer cells from apoptosis through upregulation of myeloid cell leukemia-1 (Mcl-1), an anti-apoptotic protein of the bcl-2 family. Treatment of pancreatic cancer cells with EG-VEGF results in the rapid phosphorylation of mitogen-activated protein kinase (MAPK), STAT3, and AKT, which are involved in the upregulation of Mcl-1 expression. EG-VEGF (Prok1) protects Mia PaCa II cells from apoptosis through G protein-coupled receptor (GPR)-induced activation of multiple signal pathways, and hence can be a novel target for pancreatic cancer therapy.

Prokineticin 1 modulates IL-8 expression via the calcineurin/NFAT signaling pathway

Prokineticins and their receptors are expressed in various cellular compartments in human endometrium, with prokineticin 1 (PROK1) showing a dynamic pattern of expression across the menstrual cycle and during pregnancy. Previous studies suggest that PROK1 can play an important role in implantation and early pregnancy by inducing vascular remodeling and increasing vascular permeability. Here we demonstrate that PROK1 induces the expression of IL-8, a chemokine with angiogenic properties, in endometrial epithelial Ishikawa cells stably expressing prokineticin receptor 1 and in human first trimester decidua. We also show that IL-8 promoter activity is induced by PROK1 and that this requires the presence of AP1 and NFAT motifs. The role of calcineurin/NFAT signaling pathway is confirmed by the use of specific chemical inhibitors. Additionally, PROK1 induces the expression of the regulator of calcineurin 1 isoform 4 (RCAN1-4) via the calcineurin/NFAT pathway. A modulatory role for RCAN1-4 is demonstrated by RCAN1-4 overexpression which results in the inhibition of PROK1-induced IL-8 expression whereas reduction in RCAN1-4 endogenous expression results in an increase in PROK1-induced IL-8 production. Our findings show that in endometrial cells PROK1 can activate the calcineurin/NFAT pathway to induce IL-8 expression and that this is negatively modulated by the induction of expression of RCAN1-4.

Pancreatic islet and stellate cells are the main sources of endocrine gland-derived vascular endothelial growth factor/prokineticin-1 in pancreatic cancer

AIMS

Endocrine gland-derived vascular endothelial growth factor (EG-VEGF)/prokineticins have been identified as tissue-specific angiogenic factors. This study investigates the expression and localization of EG-VEGF and its receptors in pancreatic tissues and pancreatic stellate cells (PSCs).

METHODS

mRNA levels of EG-VEGF/prokineticin 1 (PK1), prokineticin 2 (PK2) and their receptors 1 (PKR1) and 2 (PKR2) were measured in pancreatic tissues, pancreatic cancer cell lines and PSCs by quantitative reverse-transcriptase polymerase chain reaction (QRT-PCR). Protein expression of PK1, PKR1 and PKR2 was assessed in pancreatic tissues by immunohistochemistry. Growth factor-induced secretion of EG-VEGF was measured by ELISA.

RESULTS

QRT-PCR analysis in bulk tissues of normal pancreas, chronic pancreatitis and pancreatic ductal adenocarcinoma showed no significant difference of PK1 mRNA levels, whereas PK2 mRNA was barely detectable. High PK1 mRNA levels were observed only in cultured PSCs and microdissected islet cells, but not in cancer cells, and PK1 protein was localized mainly in islets and cancer-associated stromal cells. PKR1 and PKR2 proteins were present in endothelial cells of small blood vessels. TGF-beta(1) and PDGF-BB specifically stimulated PK1 secretion in PSCs.

CONCLUSIONS

Islet and/or PSC-derived PK1 might act through its receptors on endothelial cells to increase angiogenesis in pancreatic diseases.

Dual function of pancreatic endoplasmic reticulum kinase in tumor cell growth arrest and survival

Pancreatic endoplasmic reticulum kinase (PERK)-eIF2 alpha signaling, a component of the endoplasmic reticulum (ER) stress response, has been proposed as a therapeutic target due to its importance to cell survival in hypoxic tumors. In this study, we show that in addition to promoting survival, PERK can also suppress tumor growth of advanced carcinomas. Our results show that in squamous carcinoma T-HEp3 cells, which display low PERK-eIF2 alpha signaling, inducible activation of an Fv2E-PERK fusion protein results in a strong G(0)-G(1) arrest in vitro. Most importantly, Fv2E-PERK activation, in addition to promoting survival in vitro, inhibits T-HEp3 and SW620 colon carcinoma growth in vivo. Increased PERK activation is linked to enhanced p-eIF2 alpha levels, translational repression, and a decrease in Ki67, pH 3, and cycD1/D3 levels, but not to changes in angiogenesis or apoptosis. Experimental reduction of PERK activity, or overexpression of GADD34 in a spontaneously arising in vivo quiescent variant of HEp3 cells that displays strong basal PERK-eIF2 alpha activation, reverts their quiescent phenotype. We conclude that the growth-inhibitory function of PERK is preserved in tumors and upon proper reactivation can severely inhibit tumor growth through induction of quiescence. This is an important consideration in the development of PERK-based therapies, as its inhibition may facilitate the proliferation of slow-cycling or dormant tumor cells.

CS-706, a novel cyclooxygenase-2 selective inhibitor, prolonged the survival of tumor-bearing mice when treated alone or in combination with anti-tumor chemotherapeutic agents

The potent chemopreventive activity of cyclooxygenase-2 (COX-2) inhibitors has been demonstrated in a number of preclinical studies, but their potency in antitumor activity is still in dispute. In this report, we demonstrate the potent antitumor activity of a novel COX-2 inhibitor, CS-706 in mouse colorectal adenocarcinoma colon 26 tumor-bearing mice treated with or without antitumor chemotherapeutic agents. Daily oral administration of CS-706 at doses of 3-100 mg/kg from the day of tumor inoculation (Day 0) inhibited tumor growth dose-dependently, and the maximal inhibition was 67% at a dose of 100 mg/kg. In contrast, celecoxib, a well-known COX-2 inhibitor, did not inhibit tumor growth at doses up to 100 mg/kg. Furthermore, CS-706 at a dose of 1 mg/kg or above markedly prolonged the survival time of tumor-bearing mice. Administration of 30 mg/kg CS-706 from Day 7 combined with a single intravenous treatment of 10 mg/kg cisplatin on Day 7 completely regressed the tumors in all tumor-bearing mice examined, whereas only in 1 of 10 mice tumor was regressed with cisplatin treatment. Similar combination effects were observed with 10 mg/kg CS-706 and 60 mg/kg 5-fluorouracil (5-FU). Moreover, 10 mg/kg CS-706 significantly inhibited angiogenesis induced by implanted chambers with colon 26 cells in a dorsal air sac assay in mice. Collectively, these results suggest that CS-706 is a potent antitumor agent, especially in combination with conventional chemotherapeutic agents, and that the anti-angiogenic activity of CS-706 may contribute at least in part to its marked antitumor activity.

Prokineticin 2/Bv8 is expressed in Kupffer cells in liver and is down regulated in human hepatocellular carcinoma

AIM: To study the implication of prokineticin 1 (PK1/EG-VEGF) and prokineticin 2 (PK2/Bv8) in hepatocellular carcinoma angiogenesis.

METHODS: The gene induction of PK1/EG-VEGF and PK2/Bv8 was investigated in 10 normal, 28 fibrotic and 28 tumoral livers by using real time PCR. Their expression was compared to the expression of VEGF (an angiogenesis marker), vWF (an endothelial cell marker) and to CD68 (a monocyte/macrophage marker). Furthermore, the mRNA levels of PK1/EG-VEGF, PK2/Bv8, prokineticin receptor 1 and 2 were evaluated by real time PCR in isolated liver cell populations. Finally, PK2/Bv8 protein was detected in normal liver paraffin sections and in isolated liver cells by immunohistochemistry and immunocytochemistry.

RESULTS: PK2/Bv8 mRNA but not PK1/EG-VEGF was expressed in all types of normal liver samples examined. In the context of liver tumor development, we reported that PK2/Bv8 correlates only with CD68 and showed a significant decrease in expression as the pathology evolves towards cancer. Whereas, VEGF and vWF mRNA were significantly upregulated in both fibrosis and HCC, as expected. In addition, out of all isolated liver cells examined, only Kupffer cells (liver resident macrophages) express significant levels of PK2/Bv8 and its receptors, prokineticin receptor 1 and 2.

CONCLUSION: In normal liver PK2/Bv8 and its receptors were specifically expressed by Kupffer cells. PK2/Bv8 expression decreased as the liver evolves towards cancer and did not correlate with HCC angiogenesis.

Endocrine gland-derived vascular endothelial growth factor (EG-VEGF) expression in colorectal cancer

BACKGROUND AND OBJECTIVES

Vascular endothelial growth factor (VEGF) is known as an important factor in the growth and metastasis of cancer cells. In 2001, a novel angiogenesis factor, endocrine gland-derived vascular endothelial growth factor (EG-VEGF), was cloned. In this study, we investigated the expression of EG-VEGF in colorectal cancer, the relationship between its expression and clinicopathological factors, and the in vitro activity of EG-VEGF transfectants.

METHODS

We determined expression levels of EG-VEGF in 113 advanced colorectal cancers resected in our hospital by quantitative PCR, and compared the expression levels and clinicopathological findings by multivariate analyses.

RESULTS

The expression of EG-VEGF mRNA was positive in 31 cancers and negative in 82 cancers. We found that compared with the negative expression of the EG-VEGF gene, its positive expression was more frequently associated with hematogenous metastasis, and was associated with a poorer survival rate. In addition, EG-VEGF transfectants showed a higher degree of in vitro tubular formation than control cells.

CONCLUSIONS

We speculate that, in colorectal cancers, the EG-VEGF gene functions as an important factor in angiogenesis in primary and metastatic lesions, and consider that it is useful as a novel prognostic factor. EG-VEGF molecule-targeted therapy has the potential for improving survival rates.

Bv8/Prokineticin proteins and their receptors

The Bv8/Prokineticins (PKs) are a new family of peptides identified in frog, fish, reptiles and mammals that signal through two highly homologous G-protein coupled receptors, PKR1 and PKR2. Bv8/PK proteins possess a unique structural motif comprising five disulfide bonds and a completely conserved N-terminal hexapeptide sequence that is essential for the peptide's biological activities. Over the past few years, several biological functions of Bv8/PK proteins have been elucidated. This review considers all the published data on the action and physiological role of this new biological system implicated in angiogenesis and neurogenesis, in reproduction and cancer and in regulating physiological functions that underly circadian rhythms, such as the sleep/wake cycle, hormone secretion and ingestive behaviors. The high expression level of human Bv8/PK2 in bone marrow, lymphoid organs and leukocytes suggested an involvement of these peptides in hematopoiesis and in inflammatory and immunomodulatory processes. Our review highlights the role of the Bv8/PK and their receptor system in setting the pain threshold under normal and pathological conditions.

Implications of endocrine gland-derived vascular endothelial growth factor/prokineticin-1 signaling in human neuroblastoma progression

PURPOSE

Neuroblastoma is a common pediatric tumor that is derived from improperly differentiated neural crest cells (NCC). We recently revealed that endocrine gland-derived vascular endothelial growth factor/prokineticin-1 (EG-VEGF/Prok-1) is a key factor mediating the growth and differentiation of enteric NCCs during development. In this report, we further elucidate its role in neuroblastoma progression.

EXPERIMENTAL DESIGN

We studied the expression and copy number of EG-VEGF/Prok-1 receptors (PK-R1 and PK-R2) in 26 neuroblastoma tumors by real-time reverse transcription-PCR and immunohistochemical analysis. Implication of EG-VEGF/Prok-1 signaling in neuroblastoma progression was further shown in a neuroblastoma cell line (SK-N-SH).

RESULTS

We found that all neuroblastoma samples from stages II to IV expressed both PK-R1 and PK-R2. Kruskall-Wallis signed rank tests revealed that the expression level of PK-R1 transcript is associated with the stages and metastasis of the neuroblastoma (P<0.05), and PK-R2 is persistently higher in advanced-stage neuroblastoma samples. About 38% of the neuroblastoma tumors (10:26) possessed MYCN amplification, whereas no PK-R1 and PK-R2 amplifications were detected, suggesting that the overexpression of the receptors was not due to gene amplification. Subsequent functional studies showed that EG-VEGF/Prok-1 activates the Akt pathway to induce the proliferation of neuroblastoma cells. Targeted down-regulation studies revealed that EG-VEGF/Prok-1-mediated proliferation requires the presence of these two receptors, and that PK-R2 is essential for inhibiting apoptosis. In vitro migration and invasion assays also indicated that EG-VEGF/Prok-1 significantly enhances the cell migration/invasion of SK-N-SH.

CONCLUSIONS

Our study has shown for the first time that aberrant EG-VEGF/Prok-1 signaling favors neuroblastoma progression and could be a potential target for future neuroblastoma treatment.

The endocrine-gland-derived vascular endothelial growth factor (EG-VEGF)/prokineticin 1 and 2 and receptor expression in human prostate: Up-regulation of EG-VEGF/prokineticin 1 with malignancy

A new family of angiogenic factors named endocrine-gland-derived vascular endothelial growth factors (EG-VEGF)/prokineticins (PK) have been recently described as predominantly expressed in steroidogenic tissues. Whether the normal and malignant epithelial prostate cells and tissues express EG-VEGF/PK1 and PK2 and their receptors is still unknown. We studied the expression of EG-VEGF/PK1 and PK2 and their receptors (PK-R1 and PK-R2) in human prostate and their involvement in cancer. Using immunohistochemistry, Western blot, and RT-PCR, we determined the expression of EG-VEGF/PK1 in normal prostate (NP) and malignant prostate tissues (PCa), in epithelial cell primary cultures from normal prostate (NPEC) and malignant prostate (CPEC) and in a panel of prostate cell lines. In NPEC, CPEC, and in EPN, a nontransformed human prostate epithelial cell line, EG-VEGF/PK1, PK2, PK-R1, and PK-R2 mRNA levels were evaluated by quantitative RT-PCR. EG-VEGF/PK1 transcript was found in PCa, in CPEC, in EPN, and in LNCaP, whereas it was detected at low level in NP and in NPEC. EG-VEGF/PK1 was absent in androgen-independent PC3 and DU-145 cell lines. Immunochemistry confirmed that EG-VEGF/PK1 protein expression was restricted to hyperplastic and malignant prostate tissues, localized in the glandular epithelial cells, and progressively increased with the prostate cancer Gleason score advancement. EG-VEGF/PK1 and PK2 were weakly expressed in NPEC and EPN. On the other hand, their transcripts were highly detected in CPEC. PK-R1 and PK-R2 were found in NPEC, EPN, and CPEC. Interestingly, CPEC showed a significantly (P < 0.05) higher expression of EG-VEGF/PK1, PK2, PK-R1, and PK-R2 compared with NPEC and EPN. We demonstrated that PKs and their receptors are expressed in human prostate and that their levels increased with prostate malignancy. It may imply that EG-VEGF/PK1 could be involved in prostate carcinogenesis, probably regulating angiogenesis. Thus, the level of EG-VEGF/PK1 could be useful for prostate cancer outcome evaluation and as a target for prostate cancer treatment in the future.

The intratumoral microvessel density and expression of bFGF and nm23-H1 in colorectal cancer

It has previously been reported that intratumoral microvessel density (IMD), and the expression of bFGF and nm23-H1 are useful prognostic markers in colorectal cancer (CRC). In this study, a total of 100 CRCs were evaluated histopathologically, and IMD, bFGF and nm23-H1 expression were assessed by immunohistochemistry. IMD of patients increased with grade and stage, and this increase was statistically significant (p<0.05). A significantly higher incidence of high bFGF expression scores was also associated with increasing grade and stage (p<0.05). However, there was no significant difference between the grades in nm23-H1 expression (p=0.234). nm23-H1 expression occurred with lower incidence in stages C1, C2 and D than in stages B1 and B2 (p<0.05). Thus, a negative correlation was found between nm23-H1 expression and stage or lymph node metastasis (LNM) (p<0.05). IMD and bFGF expression were positively correlated with grade, stage, LNM, and lymphovascular invasion. Although positive correlation was found between IMD and bFGF, nm23-H1 expression negatively correlated with both of them. As a result, in clinical practice, increased IMD and bFGF expression and decreased nm23-H1 expression may provide valuable information in characterizing the malignant phenotype.

Endocrine gland-derived vascular endothelial growth factor is expressed in human peri-implantation endometrium, but not in endometrial carcinoma

Endocrine gland-derived vascular endothelial growth factor (EG-VEGF) is a newly identified angiogenic and permeability-enhancing factor, predominantly expressed in steroidogenic tissues. Recently, we found that EG-VEGF is also expressed in the normal peri-implantation endometrial samples from patients of reproductive ages (80%). Immunohistochemistry analysis showed that EG-VEGF is predominantly expressed in the glandular epithelial cells and its expression is dynamic during the menstrual cycle with a peak expression at the mid-luteal phase. We also found that EG-VEGF transcripts are up-regulated in all the peri-implantation endometrial samples from the patients after the ovulating dose of human chorionic gonadotropin in gonadotropin-stimulated cycles and patients receiving hormone replacement therapy. In in vitro endometrial cell culture, EG-VEGF mRNA was detected in endometrial cells only in the presence of steroids, suggesting that EG-VEGF expression is highly dependent on the steroid hormones. Subsequent expression analyses on the EG-VEGF receptors showed that hPK-R1 and hPK-R2 are differentially expressed in human endometrium, but show no significant correlation with the hormonal treatments. On the other hand, EG-VEGF transcript was rarely detected in the endometrial samples from the postmenopausal patients and patients with endometrial carcinoma. It may imply that EG-VEGF may only play a role in vascular function of peri-implantation endometrium, but is unlikely to be associated with the etiology of endometrial cancer development.

Impact of microarray technology in nutrition and food research

Microarrays have become standard tools for gene expression profiling as the mRNA levels of a large number of genes can be measured in a single assay. Many technical aspects concerning microarray production and laboratory usage have been addressed in great detail, but it remains still crucial to establish this technology in new research fields such as human nutrition and food-related areas. The correlation between diet and inter-individual variation in gene expression is an important and relatively unexplored issue in human nutrition. Therefore, nutritionists changed their research field dramatically from epidemiology and physiology towards the "omics" sciences. Nutrigenomics as a field of research is based on the complete knowledge of the human genome and refers to the entire spectrum of human genes that determine the interactions of nutrition with the organism. Nutrigenetics is based on the inter-individual, genetically determined differences in metabolism. Nutrigenomics and nutrigenetics carry the hope that individualized diet can improve human health and prevent nutrition-related diseases. In this article we give an overview of current DNA and protein microarray techniques (including fabrication, experimental procedure and data analysis), we describe their applications to nutrition and food research and point out the limitations, problems and pitfalls of microarray experiments.