Monoamine oxidase A suppresses hepatocellular carcinoma metastasis by inhibiting the adrenergic system and its transactivation of EGFR signaling

Decreased LKB1 predicts poor prognosis in Pancreatic Ductal Adenocarcinoma

Liver kinase B1 (LKB1) has been identified as a critical modulator involved in cell proliferation and polarity. The purpose of the current study was to characterize the expression pattern of LKB1 and assess the clinical significance of LKB1 expression in pancreatic ductal adenocarcinoma (PDAC) patients. LKB1 mRNA expression which was analyzed in 32 PDAC lesions and matched non-tumor tissues, was downregulated in 50% (16/32) of PDAC lesions. Similar results were also obtained by analyzing three independent datasets from Oncomine. Protein expression of LKB1 was significantly reduced in 6 PDAC cell lines and downregulated in 31.3% (10/32) of PDAC lesions compared to matched non-tumorous tissues, as determined by Western blot analysis. Additionally, tissue microarray containing 205 PDAC specimens was evaluated for LKB1 expression by IHC and demonstrated that reduced expression of LKB1 in 17.6% (36/205) of PDAC tissues was significantly correlated with clinical stage, T classification, N classification, liver metastasis and vascular invasion. Importantly, Kaplan-Meier survival and Cox regression analyses were executed to evaluate the prognosis of PDAC and found that LKB1 protein expression was one of the independent prognostic factors for overall survival of PDAC patients.

Silencing of MICAL-L2 suppresses malignancy of ovarian cancer by inducing mesenchymal-epithelial transition

Ovarian cancer remains the disease with the highest associated mortality rate of gynecologic malignancy due to cancer metastasis. Rearrangement of actin cytoskeleton by cytoskeleton protein plays a critical role in tumor cell metastasis. MICAL-L2, a member of MICAL family, can interact with actin-binding proteins, regulate actin cross-linking and coordinate the assembly of adherens junctions and tight junctions. However, the roles of MICAL-L2 in tumors and diseases have not been explored. In this study, we found that MICAL-L2 protein is significantly up-regulated in ovarian cancer tissues along with FIGO stage and associated with histologic subgroups of ovarian cancer. Silencing of MICAL-L2 suppressed ovarian cancer cell proliferation, migration and invasion ability. Moreover, silencing of MICAL-L2 prevented nuclear translocation of β-catenin, inhibited canonical wnt/β-catenin signaling and induced the mesenchymal-epithelial transition (MET). Taken together, our data indicated that MICAL-L2 may be an important regulator of epithelial-mesenchymal transition (EMT) in ovarian cancer cells and a new therapeutic target for interventions against ovarian cancer invasion and metastasis.

Trophoblast glycoprotein promotes pancreatic ductal adenocarcinoma cell metastasis through Wnt/planar cell polarity signaling

Trophoblast glycoprotein (TPBG), a 72 kDa glycoprotein was identified using a monoclonal antibody, which specifically binds human trophoblast. The expression of TPBG in normal tissues is limited; however, it is upregulated in numerous types of cancer. When TPBG is expressed at a high level, this usually indicates a poor clinical outcome. In the present study, it was demonstrated that TPBG was more commonly observed in human pancreatic ductal adenocarcinoma (PDAC) compared with normal pancreatic tissue. Immunohistochemical analysis of PDAC tissue microarrays indicated that the expression of TPBG in PDAC tissues was closely correlated with the tumor-node-metastasis stage of the tumor. Silencing of TPBG in PDAC cell lines resulted in a decreased ability of cancer cell migration and invasion. Further investigation demonstrated that the Wnt/planar cell polarity signaling pathway was suppressed, as the expression of Wnt5a and the activation of c-Jun N-terminal kinase was inhibited following TPBG knockdown. In conclusion, the present study provided evidence that TPBG is involved in PDAC metastasis, and that TPBG and its associated signaling pathways may be a suitable target for PDAC therapy.

Lysyl oxidase-like 4 (LOXL4) promotes proliferation and metastasis of gastric cancer via FAK/Src pathway

BACKGROUND

Lysyl oxidase-like 4 (LOXL4) has been found up-regulated in a variety of human malignancies, but its clinical significance and functional roles in gastric cancer (GC) remain unknown.

METHODS

Lysyl oxidase-like 4 (LOXL4) expression level in tumor tissues and human GC cell lines was evaluated by quantitative real-time polymerase chain reaction, Western blotting and immunohistochemical analyses. Its clinical significance was inferred from the analysis of 379 tissue samples of patients with GC using tissue microarray. The roles of LOXL4 in cell proliferation, migration and invasion in vitro were analyzed by gene over-expression, RNA interference and recombinant protein. Effects of LOXL4 on regulation of focal adhesion kinase/Src kinase (FAK/Src) pathway were examined by Western blotting.

RESULTS

Lysyl oxidase-like 4 (LOXL4) was up-regulated in GC tissues relative to paired non-tumor tissues, and this over-expression was significantly associated with tumor size, depth of tumor invasion, lymph node metastasis, tumor-node-metastasis (TNM) stages and poorer overall survival. Over-expression of LOXL4 has promotive effects on GC cell proliferation, migration and invasion in vitro, consistent with this, LOXL4 knockdown has inhibitive effects on GC cell proliferation, migration and invasion. Furthermore, recombinant human LOXL4 protein also promoted GC cell proliferation and migration. Subsequent mechanistic studies showed that LOXL4 could activate FAK/Src pathway to enhance cell-extracellular matrix adhesion.

CONCLUSIONS

Taken together, our data reveal that up-regulation of LOXL4 expression is a frequent event in GC progression, contributes to tumor cell proliferation and metastasis, and LOXL4 may be a potential independent prognostic marker and therapeutic target for GC.

Elevated autocrine EDIL3 protects hepatocellular carcinoma from anoikis through RGD-mediated integrin activation

BACKGROUND

A remolded microenvironment in hepatocellular carcinoma (HCC) caused by abnormally expressed matricellular proteins could promote HCC progression. The cell-matrix interactions mediated by integrins play an important role in tumor microenvironment. Epidermal Growth Factor-like repeats and Discoidin I-Like Domains 3 (EDIL3), an extracellular matrix (ECM) protein with angiogenic and anti-inflammatory effects, is abnormally highly expressed in HCC. Here we aim to analyze its expression in liver and HCC tissues, investigate the underlined mechanisms accounted for HCC progression.

METHODS

EDIL3 expression level is examined in normal liver, cirrhotic liver and HCC at both mRNA and protein level. The association between EDIL3 and clinical outcomes is analyzed. The pattern of EDIL3 expression and location is examined using Immunofluorescence and ELISA. Overexpression or knock-down of EDIL3 in a panel of cell lines are subjected to assays related to proliferation, invasion, and anoikis to investigate the mechanisms of this matrix protein in HCC progression. Recombinant EDIL3 treatment is applied to confirm the results.

RESULTS

Compared with normal liver and cirrhotic liver, EDIL3 is elevated in HCC. High level of EDIL3 protein is much more commonly in patients with larger tumor or portal vein tumor thrombus (PVTT) formation, associated with poor prognosis. EDIL3 is abundantly expressed in HCC cells and secreted by cancer cells. In vitro and in vivo studies indicate that EDIL3, probably in an autocrine manner, inhibits anoikis and promotes anchorage-independent growth of HCC cells. Further mechanistic studies suggest integrin ligation by EDIL3 and thus that the sustained activation of the FAK-Src-AKT signal is responsible for the anoikis resistance and anchorage independence. Both the administration of cilengitide, a RGD-containing integrin antagonist, and silencing of integrin αV, an important RGD-binding integrin, results in the blockade of anoikis-resistance induced by EDIL3.

CONCLUSION

Our study suggests that high levels of autocrine EDIL3 may contribute to a receptive microenvironment for the survival of detached HCC cells and may involve in cancer cell spreading. We also highlight the importance of interaction between EDIL3 and integrin αV and suggest disrupting the ligation of EDIL3 to integrins via RGD-blocking in selected patients may bear potential therapeutic value.

LRG1 is an independent prognostic factor for endometrial carcinoma

Endometrial cancer (EC) is one of the most common female malignancies. The patients with high-risk factors may have poor prognosis. Therefore, there is an urgent need to find a new molecule to more accurately predict survival of patients. Leucine-rich-alpha-2-glycoprotein1 (LRG1), one of leucine-rich repeat family, was closely associated with cancer metastasis and poor prognosis. The biological functions and the expression level of LRG1 remain obscure in EC. In this study, by immunohistochemical analysis of 242 EC patient tissues, we found that LRG1 expression was associated with stage and lymphatic metastasis in both test cohort (133 patients) and validation cohort (109 patients). Furthermore, to investigate the prognostic value of LRG1 in endometrial carcinoma, we analyzed the correlation between variables and overall survival with Cox proportional hazard regression. The result showed that LRG1 was an independent prognostic factor for overall survival of endometrial carcinoma patients. To further evaluate the prognostic efficiency of LRG1 in endometrial carcinoma, we compared the sensitivity and specificity of LRG1 in endometrial carcinoma prognosis by logistic regression. The result showed that LRG1 combining with other clinicopathological risk factors was a stronger prognostic model than clinicopathological risk factors alone or their combination. Thus, LRG1 potentially offered clinical value in directing personal treatment for endometrial carcinoma patients.