Desmoglein 2 and desmocollin 2 depletions promote malignancy through distinct mechanisms in triple-negative and luminal breast cancer.

BACKGROUND: Aberrant expressions of desmoglein 2 (Dsg2) and desmocollin 2(Dsc2), the two most widely distributed desmosomal cadherins, have been found to play various roles in cancer in a context-dependent manner. Their specific roles on breast cancer (BC) and the potential mechanisms remain unclear. METHODS: The expressions of Dsg2 and Dsc2 in human BC tissues and cell lines were assessed by using bioinformatics analysis, immunohistochemistry and western blotting assays. Wound-healing and Transwell assays were performed to evaluate the cells' migration and invasion abilities. Plate colony-forming and MTT assays were used to examine the cells' capacity of proliferation. Mechanically, Dsg2 and Dsc2 knockdown-induced malignant behaviors were elucidated using western blotting assay as well as three inhibitors including MK2206 for AKT, PD98059 for ERK, and XAV-939 for ß-catenin. RESULTS: We found reduced expressions of Dsg2 and Dsc2 in human BC tissues and cell lines compared to normal counterparts. Furthermore, shRNA-mediated downregulation of Dsg2 and Dsc2 could significantly enhance cell proliferation, migration and invasion in triple-negative MDA-MB-231 and luminal MCF-7 BC cells. Mechanistically, EGFR activity was decreased but downstream AKT and ERK pathways were both activated maybe through other activated protein tyrosine kinases in shDsg2 and shDsc2 MDA-MB-231 cells since protein tyrosine kinases are key drivers of triple-negative BC survival. Additionally, AKT inhibitor treatment displayed much stronger capacity to abolish shDsg2 and shDsc2 induced progression compared to ERK inhibition, which was due to feedback activation of AKT pathway induced by ERK inhibition. In contrast, all of EGFR, AKT and ERK activities were attenuated, whereas ß-catenin was accumulated in shDsg2 and shDsc2 MCF-7 cells. These results indicate that EGFR-targeted therapy is not a good choice for BC patients with low Dsg2 or Dsc2 expression. Comparatively, AKT inhibitors may be more helpful to triple-negative BC patients with low Dsg2 or Dsc2 expression, while therapies targeting ß-catenin can be considered for luminal BC patients with low Dsg2 or Dsc2 expression. CONCLUSION: Our finding demonstrate that single knockdown of Dsg2 or Dsc2 could promote proliferation, motility and invasion in triple-negative MDA-MB-231 and luminal MCF-7 cells. Nevertheless, the underlying mechanisms were cellular context-specific and distinct.

Changes in microRNAs associated with Twist-1 and Bcl-2 overexpression identify signaling pathways.

Epithelial-mesenchymal transition (EMT) is regulated by multiple signal transduction pathways. Twist-1 is one of the most important transcription factors in these pathways. In a previous study, we found that Bcl-2 enhanced the role of Twist-1 in EMT. Coexpression of Twist-1 and Bcl-2 may play an import role in vasculogenic mimicry (VM) through regulation of EMT. Moreover, regulators of EMT and VM are known to be important targets for microRNAs (miRNAs). To better understand how these critical pathways are induced by coexpression of Twist-1 and Bcl-2, we performed a comprehensive comparative bioinformatics analysis using microarrays on HCCs that overexpressed Twist-1 and Bcl-2. Eleven miRNAs associated with coexpression of Twist-1 and Bcl-2 were selected from the comprehensive analysis of miRNA microarray and ChIP-seq analysis. Changes in miRNAs were associated with significant differences in the expression of genes involved in signal transduction pathways related to processes including tumor invasion, metastasis, angiogenesis, and tumor cell shape. We confirmed the role of Twist-1 and Bcl-2 coexpression in HCC cells using wound healing assays, invasion assays, and 3D Matrigel assays. Furthermore, the role of miR-27a as a crucial regulator of EMT and VM was confirmed in HCC cells by RT-PCR and western blot analysis. These findings provide evidence that Bcl-2 enhances the role of Twist-1 in VM and EMT through miRNAs.

Key nodes of a microRNA network associated with the integrated mesenchymal subtype of high-grade serous ovarian cancer.

Metastasis is the main cause of cancer mortality. One of the initiating events of cancer metastasis of epithelial tumors is epithelial-to-mesenchymal transition (EMT), during which cells dedifferentiate from a relatively rigid cell structure/morphology to a flexible and changeable structure/morphology often associated with mesenchymal cells. The presence of EMT in human epithelial tumors is reflected by the increased expression of genes and levels of proteins that are preferentially present in mesenchymal cells. The combined presence of these genes forms the basis of mesenchymal gene signatures, which are the foundation for classifying a mesenchymal subtype of tumors. Indeed, tumor classification schemes that use clustering analysis of large genomic characterizations, like The Cancer Genome Atlas (TCGA), have defined mesenchymal subtype in a number of cancer types, such as high-grade serous ovarian cancer and glioblastoma. However, recent analyses have shown that gene expression-based classifications of mesenchymal subtypes often do not associate with poor survival. This "paradox" can be ameliorated using integrated analysis that combines multiple data types. We recently found that integrating mRNA and microRNA (miRNA) data revealed an integrated mesenchymal subtype that is consistently associated with poor survival in multiple cohorts of patients with serous ovarian cancer. This network consists of 8 major miRNAs and 214 mRNAs. Among the 8 miRNAs, 4 are known to be regulators of EMT. This review provides a summary of these 8 miRNAs, which were associated with the integrated mesenchymal subtype of serous ovarian cancer.

[Protective effect of arctigenin in GK rats combined with hypertension macroangiopathy].

To study the protective effect of Arctigenin in goto-kakizaki (GK) rats combined with hypertension macroangiopathy. Six-week-old GK rats were divided randomly according to blood glucose level into four groups: the model group and low, middle and high dose arctigenin groups (12.5, 25, 50 mg x kg(-1)), with Wistar rats as the normal group. All of GK rats were given high-glucose and high-fat diet. After 16 weeks, GK rats were orally administrated with 10 mg x kg(-1) x d(-1) N-Ω-nitro-L-arginine methyl ester for eight weeks. During the modeling, all of arctigenin groups were orally administrated with different dose of arctigenin twice a day; The model group and the normal group were given solvents. At the beginning, mid-term and end of the experiment, blood glucose was measured. At the end of the experiment, efforts were made to detect blood pressure, collect abdominal aortic blood after anesthesia, fix thoracic aorta after bloodletting to make paraffin sections, observe morphological characteristics and detect the expression of VEGF by immunohistochemistry. According to the results, the blood glucose rose in all GK rats, with no significant difference between the drug group and the model group. At the end of the experiment, the blood pressure significantly increased in GK rats, indicating that Arctigenin could notably reduce the blood pressure in GK rats in a dose-dependent manner. The blood routine test showed increases in both the total white blood cell count and differential blood count, MPV and PDW, abnormal blood platelet parameters and decrease in PLT in GK rats, suggesting that Arctigenin could remarkably reduce the total white blood cell count and differential blood count, MPV and PDW. The thoracic aortic morphological observation revealed obvious endangium lesions in GK rats, demonstrating that Arctigenin could ameliorate the lesion extent. VEGF immumohistochemical staining showed a higher VEGF expression in the model group but lower expression in Arctigenin groups. In conclusion, Arctigenin had a protective effect on aorta in GK rats. Its mechanism may be related to blood pressure lowering, anti-inflammation, improvement in blood platelet function and reduction of VEGF expression.

Resistance to apoptosis should not be taken as a hallmark of cancer.

In the research community, resistance to apoptosis is often considered a hallmark of cancer. However, pathologists who diagnose cancer via microscope often see the opposite. Indeed, increased apoptosis and mitosis are usually observed simultaneously in cancerous lesions. Studies have shown that increased apoptosis is associated with cancer aggressiveness and poor clinical outcome. Furthermore, overexpression of Bcl-2, an antiapoptotic protein, is linked with better survival of cancer patients. Conversely, Bax, CD95, Caspase-3, and other apoptosis-inducing proteins have been found to promote carcinogenesis. This notion of the role of apoptosis in cancer is not new; cancer cells were found to be short-lived 88 years ago. Given these observations, resistance to apoptosis should not be considered a hallmark of cancer.

Promotion of tumor cell metastasis and vasculogenic mimicry by way of transcription coactivation by Bcl-2 and Twist1: a study of hepatocellular carcinoma.

UNLABELLED: The antiapoptotic protein Bcl-2 plays multiple roles in apoptosis, immunity, and autophagy. Its expression in tumors correlates with tumor grade and malignancy. The recapitulation of the normal developmental process of epithelial-mesenchymal transition (EMT) contributes to tumor cell plasticity. This process is also a characteristic of metastatic cells and vasculogenic mimicry. In the present study we report functional and structural interactions between Bcl-2 and the EMT-regulating transcription factor Twist1 and the relationship with metastasis and vascular mimicry. Bcl-2 and Twist1 are coexpressed under hypoxia conditions. The Bcl-2 can bind to Twist1 in vivo and in vitro. This interaction involves basic helix-loop-helix DNA binding domain within Twist1 and through two separate domains within Bcl-2 protein. Formation of the Bcl-2/Twist1 complex facilitates the nuclear transport of Twist1 and leads to transcriptional activation of wide ranges of genes that can increase the tumor cell plasticity, metastasis, and vasculogenic mimicry. Finally, nuclear expression of Bcl-2 and Twist1 is correlated with poor survival of these patients in a cohort of 97 cases of human hepatocellular carcinoma. CONCLUSION: The results describe a novel function of Bcl-2 in EMT induction, provide insight into tumor progression, and implicate the Bcl-2/Twist1 complex as a potential target for developing chemotherapeutics.

[Clinical features and outcome analyses of newly-diagnosed multiple myeloma with extramedullary involvements].

OBJECTIVE: To explore the clinical features and prognostic factors of newly-diagnosed multiple myeloma (MM) with extramedullary (EM) involvements. METHODS: The clinical features, efficacies, survival rates and prognostic factors were retrospectively analyzed in 46 MM patients with EM (group A) from January 2000 to October 2011. And another 53 MM patients without EM (group B) were selected as the controls. RESULTS: The median age of Group A was 58 years. Compared with group B, the incidence of EM was associated with a higher level of ß2-microglobulin (ß2-MG) and extensive bone disease. The most common location of EM was soft tissues. And the total effective rates of groups A and B were 58.5% (24/41) and 78.8% (41/52) respectively. The difference was statistically significant (P = 0.042). The median follow-up time was 28(2-88) months. The estimated overall survival (OS) of the patients with EM was significantly shorter than those without EM (42.6 vs 53.9 months, P = 0.009). Log-rank univariate analysis showed that the number of osteolytic lesions ≥ 3, ß2-MG ≥ 5.5 mg/L, hemoglobin ≤ 110 g/L and albumin ≤ 30 g/L were poor prognostic factors in MM patients with EM. Multivariate analysis with Cox model showed only the number of osteolytic lesions ≥ 3 (OR = 2.327, 95%CI: 1.282 - 4.224) and ß2-MG ≥ 5.5 mg/L (OR = 2.677, 95%CI: 1.092 - 6.566) were statistically significant. CONCLUSIONS: Multiple EM lesions may be involved in MM patients. For the patients with EM, the response to conventional chemotherapy is poor and the prognosis is unfavorable, especially for those with a high level of ß2-MG or the number of osteolytic lesions ≥ 3.

[Overexpression of the receptor tyrosine kinase EphA2 in choroidal melanoma: correlation with vesculogenic mimicry and prognosis].

OBJECTIVE: To study the correlation of EphA2 protein expression with vesculogenic mimicry (VM), clinicopathological characteristics and prognosis in choroidal melanoma (CM). METHODS: It was a retrospective case series study. Between January 1992 and December 2005, 56 cases of human CM with clinicopathologic data from the Second Hospital of Tianjin Medical University were studied. HE stainings were performed to observe the microcirculation patterns in tumor tissue specimens. VM was found in 26 of the 56 cases using CD31/periodic acid-Schiff (PAS) double staining and transelectron microscopy. All cases were divided into two groups: VM-positive and VM-negative. Immunohistochemical staining was performed on paraffin sections of the 56 cases of CM specimens to investigate the expression of EphA2. According to tumor cells positive rate and staining intensity of the results of evaluation, the specimens were divided into low expression and high expression groups.χ(2)-test and t-test were used to analyzed the enumeration data and measurement data, respectively. Survival analysis was used to further elucidate its correlation with clinicopathological characteristics, VM and prognosis. Cox proportional hazard model was used to analyzed the influence factors of prognosis. RESULTS: VM channels were found in 26 of the 56 CM cases and VM-negative 30 cases. VM-positivity was related to cell type, tumor size and recurrence and metastasis, and the differences were statistically significant (χ(2) = 4.612, 5.346, 5.213; P = 0.036, 0.021, 0.027). The results showed that EphA2 was up-regulated in the VM-positive group compared with the group of VM-negative group. The positive rates of EphA2 expression in the VM-positive group and VM-negative group were 92.3% (25/26) and 70.0% (21/30), respectively, with a significant difference between the two groups (t = 2.247, P = 0.009). The EphA2 protein was expressed in epithelioid (10/12), mixed (11/15) and spindle (41.40%) cell types, with a significant difference among these histological types (χ(2) = 6.513, P = 0.010). The expression rate of EphA2 protein were significantly higher in large (54.55%, 18/33) than small (45.45%, 15/33) tumors, and the expression of EphA2 in metastatic and recurrence patients (10/11) were significantly higher compared with controls (31.11%, 14/45) (χ(2) = 4.556, 8.211;P = 0.016, 0.005). Kaplan-Meier survival analysis showed the presence of VM resulted in a poor prognosis (t = 9.263, P = 0.000). The Cox proportional hazards model indicated that the EphA2 overexpression and the presence of VM were independent predictors of a poor prognosis (χ(2) = 12.041, P = 0.001). Moreover, there was a significant positive correlation between them (r = 0.412, P < 0.05). CONCLUSION: The results of this study demonstrate that EphA2 may play a critical role in the formation process of VM in CM, implicating EphA2 as a valuable marker for the prediction of recurrence, metastasis and prognosis in CM patients.

Promoting melanoma growth and metastasis by enhancing VEGF expression.

Angiogenesis plays an essential role in tumor growth and metastasis and is a promising target for cancer therapy. Vascular endothelial growth factor (VEGF) is a key regulator of angiogenesis. The present study was designed to determine the role of VEGF in tumor growth and metastasis. The sequences for the VEGF gene were cloned into expression plasmids and then transfected into melanoma B16 cells. Overexpression of VEGF transfected with expression plasmids or given exogenous VEGF and epidermal growth factor (EGF) significantly enhanced tumor cell proliferation, migration, and invasion. Tumor growth and metastasis of melanoma B16 cells transfected with VEGF plasmid were significantly promoted compared with those of cells administered with exogenous VEGF or EGF. These results indicated that VEGF can be an effective antiangiogenic strategy for melanoma.

Promotion of hepatocellular carcinoma metastasis through matrix metalloproteinase activation by epithelial-mesenchymal transition regulator Twist1.

E-cadherin loss is a key biological mechanism in tumour invasion. As a main regulator of epithelial-mesenchymal transition (EMT) mechanism-mediated invasion and metastasis, Twist1 plays an important role through its regulation of E-cadherin expression. However, whether or not Twist2 has the same function in tumour metastasis remains unclear. The purpose of this study is to investigate the expressions and different roles of Twist1 and Twist2 in human hepatocellular carcinoma (HCC). The expressions of Twist1 and Twist2 in HCC tissue were evaluated by immunohistochemical staining. The role of Twist1 and Twist2 in invasiveness was also evaluated in vitro by using HCC cell lines. Twist1 nuclear overexpression is found to be correlated with HCC metastasis, and its expression is negatively correlated with E-cadherin expression in human tissue. Twist2, a Twist1 homology protein, only expresses in the cytoplasm and shows no significant correlation with HCC metastasis. By ectopic transfection of Twist1 and Twist2 into the HCC cells, HepG2 and PLC, Twist1 is able to down-regulate E-cadherin expression and promote matrix metalloproteinase (MMP) activation, specifically in MMP2 and MMP9. In functional assays, Twist1 is found to promote invasion in HepG2 and PLC cells, but the invasion ability of the groups is not affected Twist2. Our findings indicate that Twist1 induces HCC invasion via increased activity in MMPs, leading to poor clinical prognoses. The results of this study also demonstrate a novel cogitation in Twist2, which has no effect on HCC invasion and metastasis. Twist1 may contribute to HCC invasion and metastasis and may be used as a novel therapeutic target for the inhibition of HCC metastasis.

Expression and functional significance of Twist1 in hepatocellular carcinoma: its role in vasculogenic mimicry.

UNLABELLED: The up-regulation and nuclear relocation of epithelial-mesenchymal transition (EMT) regulator Twist1 have been implicated in the tumor invasion and metastasis of human hepatocellular carcinoma (HCC). The term vasculogenic mimicry (VM) refers to the unique capability of aggressive tumor cells to mimic the pattern of embryonic vasculogenic networks. However, the relationship between Twist1 and VM formation is not clear. In this study, we explored HCC as a VM and EMT model in order to investigate the role of Twist1 in VM formation. We first examined the expression of Twist1 in human HCC samples and cell lines and found that Twist1 was frequently overexpressed in the nuclear relocation occurring in VM-positive HCCs (13/18 [72%]). Twist1 nuclear expression was likewise significantly associated with VM formation. Clinicopathological analysis revealed that both VM and Twist1 nuclear expressions present shorter survival durations than those without expression. We consistently demonstrated that an overexpression of Twist1 significantly enhanced cell motility, invasiveness, and VM formation in an HepG2 cell. Conversely, a knockdown of Twist1 by the short hairpin RNA approach remarkably reduced Bel7402 cell migration, invasion, and VM formation. Using chromatin immunoprecipitation, we also showed that Twist1 binds to the vascular endothelial (VE)-cadherin promoter and enhances its activity in a transactivation assay. CONCLUSION: The results of this study indicate that Twist1 induces HCC cell plasticity in VM cells more through the suppression of E-cadherin expression and the induction of VE-cadherin up-regulation than through the VM pattern in vivo and in a three-dimensional in vitro system. Our findings also demonstrate a novel cogitation in cancer stem-like cell differentiation and that related molecular pathways may be used as novel therapeutic targets for the inhibition of HCC angiogenesis and metastasis.

[Significance of MUM-1/IRF4 protein expression in follicular lymphoma].

OBJECTIVE: To study the expression of MUM-1/IRF4 and its significance in follicular lymphoma. METHODS: Ninety-eight cases of follicular lymphoma were enrolled into the study. They were graded according to the 2008 WHO criteria. The expression of MUM-1/IRF4 protein and other markers (CD10, bcl-6, bcl-2 and Ki-67) was studied using tissue microarray and immunohistochemistry. RESULTS: Amongst the 98 cases studied, there were 24 grade 1 cases, 30 grade 2 cases, 26 grade 3A cases and 18 were grade 3B cases. The rates of expression of MUM-1/IRF4, CD10, bcl-6, bcl-2 and Ki-67 (≥ 25%) were 39.8% (39/98), 62.2% (61/98), 80.6% (79/98), 87.8% (86/98) and 50.0% (49/98), respectively. MUM-1/IRF4 predominantly expressed in high-grade follicular lymphoma and showed a significantly positive correlation with lymphoma grade (r = 0.628, P = 0.000) and Ki-67 index (r = 0.473, P = 0.000). MUM-1/IRF4 expression had a significantly negative correlation with CD10 expression (r = -0.597, P = 0.000), but no correlation with bcl-6 and bcl-2 expression. CONCLUSIONS: MUM-1/IRF4 expression is significantly higher in high-grade follicular lymphoma, indicating that these cases have a high proliferative activity, more aggressive behavior and poorer prognosis. MUM-1/IRF4, when strongly expressed, is another helpful marker for the diagnosis of high-grade follicular lymphoma.

[Analysis of mitochondrial DNA D-loop region mutation and its significance in human oncocytoma].

OBJECTIVE: To investigate the mutation in mitochondrial DNA displacement-loop (mtDNA D-loop) region in oncocytoma and its relationship with tumorigenesis and tumor development. METHODS: The mtDNA D-Loop region of 20 thyroid or renal oncocytomas and the adjacent normal tissues were amplified by PCR, and then sequenced. Five human fetal renal tissues were collected as matched controls. RESULTS: Among the 20 oncocytomas, 21 mutations which focused on hypervariable region I (HVI) were found in 7 tumor tissues and 1 normal tissue with the mutation rates of 35% and 5%, respectively. At the same time, 191 polymorphisms were found in the 20 cases. CONCLUSION: mtDNA D-loop region, especially HV I, is the mutational hotspot of oncocytomas, which may be closely related with mtDNA duplicating rate and the function of mitochondria.

[Relationship between EGFR and K-ras mutations and clinicopathological characteristics and response to erlotinib treatment in 301 Chinese patients with non-small cell lung cancer].

OBJECTIVE: To investigate gene mutations of epidermal growth factor receptor (EGFR) and K-ras in Chinese patients with non-small cell lung cancer (NSCLC) and its clinicopathological significance, and to analyze the correlation between these mutations and tumor response to erlotinib treatment. METHODS: Mutations of exons 18, 19, 20 and 21 of the EGFR and codons 12, 13 of the K-ras in 301 cases of NSCLC were detected by PCR-amplification and gene sequencing. The relationship between the mutations and clinicopathological characteristics of the 301 patients was analyzed. RESULTS: EGFR mutations were present in 32.9% (99/301) of the samples: 3 mutation in exon 18, 59 in exon 19, 2 in exon 20, and 35 in exon 21. Mutations of K-ras were present in 4.7% (14/301) of the samples: 13 in codon 12 and 1 in codon 13. EGFR mutations were never found in tumors with K-ras mutations, suggesting a mutually exclusive relationship. EGFR mutations were more common in adenocarcinomas, non-smokers and females. Seven out of 10 erlotinib-treated patients with disease control carried EGFR mutation. CONCLUSION: The frequency of EGFR mutation in Chinese NSCLC patients is higher than that in Westerners, but the frequency of K-ras mutation is quite opposite. Combined detection of EGFR gene and K-ras gene mutation may help clinicians to choose patients who may gain benefit from EGFR tyrosine kinase inhibitor (EGFR-TKI) treatment, and to predict their response to erlotinib treatment and prognosis.

[Expression of SLP-2 protein in esophageal squamous cell carcinoma is associated with cancer invasion].

OBJECTIVE: To study the expression of stomatin-like protein-2 (SLP-2) in esophageal squamous cell carcinoma (ESCC), and analyze the correlation between SLP-2 expression and clinicopathological features. METHODS: The expression of SLP-2 protein in ESCC tissues (18 and 220 cases respectively) was detected by Western blot and IHC. The association between SLP-2 expression and clinicopathological features was analyzed. RESULTS: Compared with normal epithelium, 13 cases of ESCC tissues showed a higher expression of SLP-2 on the protein level (72.2%, 13/18). IHC analysis on tissue microarray revealed that the expression rate of SLP-2 protein in ESCC was 54.1% and in normal esophageal mucosa was 3.6%, showing a significant difference (P < 0.001). SLP-2 high-level expression correlates with the extent of ESCC invasion (P = 0.033), but not with other clinicopathologic characteristics (P > 0.05). CONCLUSION: SLP-2 as a novel cancer-related gene may play an important role in tumorigenesis of ESCC. The overexpression of SLP-2 may be closely associated with the invasion of esophageal cancer.

[Relationship between SLP-2 expression and prognosis in laryngeal squamous cell carcinoma and mammary invasive carcinoma].

OBJECTIVE: To study the expression of stomatin like protein-2 (SLP-2) at mRNA and protein levels in two kinds of malignant epithelial tumors, including laryngeal squamous cell carcinoma (LSCC) and invasive breast cancer, and to study the relations of SLP-2 expression and clinicopathologic parameters with the prognosis. METHODS: RT-PCR and Western blot were used to detect the expression of SLP-2 mRNA and protein in LSCC and their normal counterparts (46 and 10 pair, respectively). Immunohistochemistry was carried on tissue array constructed from LSCC (104 cases) and breast cancer (263 cases), respectively. The association between SLP-2 expression and clinicopathologic parameters was analyzed. RESULTS: LSCC showed a higher expression of SLP-2 than that of their normal counterparts (negative expression) at mRNA (83%, 38/46) and protein (7/10) level. Immunohistochemical analysis of LSCC showed that compared with negative expression in normal laryngeal epithelium (0/20), a higher SLP-2 expression was detected in LSCC (36/104, P=0.000) and associated with the advanced clinical stage (P<0.01) and lymph node metastasis (P=0.003). Immunohistochemical study of invasive breast cancer demonstrated that compared with negative expression in normal breast tissue (0/10), more than one half of the cases showed a high SLP-2 expression (52.5%, 138/263, P=0.000) in breast cancer, which correlated with the tumor size (P=0.020), lymph node metastasis (P<0.01), advanced clinical stage (P<0.01), distant metastasis (P=0.002) and HER2/neu protein expression (P=0.037). Survival analysis showed a shorter overall survival probability in patients with a high SLP-2 expression. It was considered that lymph node metastasis, positive HER2/neu expression, and high-level SLP-2 expression may act as the independent prognostic factors for those tumors. CONCLUSIONS: A high expression level of SLP-2 may be associating with the development of invasion and metastasis in LSCC and breast cancer, and SLP-2 is also considered working as an independent factor indicating a poor prognosis clinically in breast cancer.

[Correlation between expressions of matrix metalloproteinase-2 & 9 and vasculogenic mimicry in gastrointestinal stromal tumors].

OBJECTIVE: To study the correlation between the expression of matrix metalloproteinase (MMP)-2, MMP-9, vascular endothelial growth factor (VEGF) and vasculogenic mimicry (VM) in gastrointestinal stromal tumors (GIST). METHODS: The immunohistochemical staining indices (SI) of MMP-2, MMP-9, VEGF were assessed on specimens of 84 human cases with GIST (21 VM-positive cases). Gelatin zymography analysis of the activity of MMP-2 and MMP-9 activities were performed on another 42 human cases of GIST with fresh tissue (22 VM-positive cases). RESULTS: The staining indices (SI) of MMP-2 and MMP-9 were higher in the VM-positive group (4.10 +/- 2.05 and 3.43 +/- 1.89 respectively) than in the VM-negative group (2.98 +/- 1.97 and 2.38 +/- 1.84 respectively, both P < 0.05); there was no statistic difference in the SI of VEGF between VM-positive and VM-negative group. Gelatin zymography analysis showed that the activity of MMP-2 and MMP-9 were significantly higher in the VM-positive group (3.62 +/- 3.95 and 4.77 +/- 5.29 respectively) than in the VM-negative group (1.26 +/- 1.21 and 2.11 +/- 1.54 respectively, both P < 0.05). CONCLUSION: The expression of MMP-2 and MMP-9 correlates with VM formation in GIST.

[Pilot study of differentiation of bone marrow derived mesenchymal stem cells into endothelial cells induced by B16 melanoma cells in vitro].

OBJECTIVE: Bone-marrow derived mesenchymal stem cells (BMSC) have the potential to differentiate into endothelial cells. The aim of the study was to investigate the induction process of BMSC by B16 melanoma cells in vitro and to analyze the role of VEGF-a in the process. METHODS: A co-culture system containing BMSC and B16 melanoma cells based on transwell indirect model was established, and the induction process of BMSC by B16 melanoma cells was studied in vitro. RESULTS: BMSC were isolated from the bone marrow of C57 mice. BMSC expressed CD105, CD90, CD73, CD44 and CD166, and acquired expressin of endothelial phenotype markers including VEGFR-1, VEGFR-2 and Factor VIII after co-culture with B16 melanoma cells for 48 hours. The expression level of VEGFR-2 would be double and Factor VIII threefold more by extending the co-culture time to 72 hours. In the co-culture system, B16 melanoma cells also up-regulated the expression of VEGF-a. CONCLUSIONS: VEGF-a plays a significant role in the differentiation of BMSC into cells of endothelial phenotype, therefore, is important to tumor angiogenesis.

[Correlation of vasculogenic mimicry with clinicopathologic features and prognosis of ovarian carcinoma].

OBJECTIVE: To explore the existence of vasculogenic mimicry (VM) in ovarian carcinoma and its correlationship with the clinicopathologic features and prognosis of the tumor. METHODS: A total of 84 ovarian carcinoma cases were collected with complete clinical and prognostic data. CD31 immunohistochemistry and PAS special stain were used to investigate VM in the tumor tissue. Immunohistochemical staining of VEGF, MMP-2, MMP-9, E-cadherin, beta-catenin, and Vimentin were used to explore the pathogenesis of VM. RESULTS: Totally 36 of 84 cases exhibited evidence of VM. FIGO classification, pathologic grades and histological types were significantly different between the VM and non-VM groups. Expression of VEGF, MMP-2, MMP-9, E-cadherin and beta-catenin were higher in the VM group than in the non-VM group. Kaplan-Meier survival curve analysis showed that cases of the VM group had a lower survival rate than that of the non-VM group (P = 0.04). CONCLUSIONS: Vasculogenic mimicry exists in ovarian carcinoma. Ovarian carcinomas with a high grade malignancy have a high incidence of VM formation, a higher incidence of metastases and a lower survival rate. High expression of MMP-2 and MMP-9 may contribute to the formation of VM in the ovarian cancer.

[The mechanisms of microenvironments influence on vasculogenic mimicry between intraocular and subcutaneous melanoma].

OBJECTIVE: To investigate the influence of different microenvironments on melanoma vasculogenic mimicry, invasiveness and metastasis behavior. METHODS: It was an experimental study. Sixty C57BL/6J mice were randomly divided into two groups with 30 mice per group. Melanoma B16 cells were injected into the subretinal space and groin area of mice synchronously. The number of each type of microcirculation pattern was counted. The invasion and metastasis were observed. EphA2, MMP-2 and MMP-9 expression and their mRNA levels were detected by immunohistochemical staining and real time RT-PCR and compared between two groups. RESULTS: Five invasions and six lung metastases were found in the subretinal group while no invasion and metastasis were found in the groin group. The number of VM channels was significantly higher in subretinal group (t = 4. 188, P = 0.000). However, no significant difference of mosaic vessel and endothelium-dependent vessel was observed between two groups (t = 1.473, 1.805; P = 0.146, 0.076, respectively). EphA2, MMP-2 and MMP-9 expression was significantly higher in the subretinal group (data not shown). The mRNA levels of EphA2, MMP-2 and MMP-9 were rather higher in the subretinal tumor (t = 3.642, 8.109, 9.357; P = 0.002, 0.001 and 0.001, respectively). There was a positive association in melanoma cells of the VM between expression of EphA2 (r = 0.412, P = 0.021) but no statistically significant correlation between VM and MMP-2 (P > 0.05), nor between VM and MMP-9. CONCLUSIONS: Different microenvironments affect invasiveness and blood supply patterns of melanoma. Melanoma cells in intraocular microenvironment increased EphA2 expression which induced the formation of VM channels. Moreover, the expression of MMP-2 and MMP-9 in tumor tissue increased to enhance the invasiveness and metastasis behavior.