The role of oxysterol binding protein‐related protein 5 in pancreatic cancer

The expression of oxysterol binding protein‐related protein (ORP) 5 is related to invasion and a poor prognosis in pancreatic cancer patients. ORP5 induced the expression of sterol response element binding protein (SREBP) 2 and activated the downstream gene of sterol response element. ChIP using SREBP2 antibody revealed that histone deacetylase 5 (HDAC5) was one of the downstream genes of SREBP2. The effect of HMG‐CoA reductase inhibitors (statins) were analyzed according to the expression level of ORP5. The invasion rate and growth was suppressed in cells that strongly expressed ORP5 in a time‐ and dose‐dependent manner, but had less effect in cells weakly expressing ORP5, suggesting that when the potential of invasion and growth relies on the cholesterol synthesis pathway, it becomes sensitive to HMG‐CoA reductase inhibitor. Furthermore, HDAC inhibitor, tricostatin A, induced the expression of phosphatase and tensin homolog as well when ORP5 was suppressed or the cells were treated with statin. Treatment with both statin and tricostatin A showed a synergistic antitumor effect in cells that highly expressed ORP5. Therefore, in some pancreatic cancers, continuous ORP5 expression enhances the cholesterol synthesis pathway and this signal transduction regulates phosphatase and tensin homolog through HDAC5 expression. This is the first report to detail how the signal transduction of cholesterol synthesis is related to cancer invasion and why statins can suppress invasion and growth. (Cancer Sci 2010; 101: 898–905)     

Caveolin-1 is related to invasion,survival, and poor prognosis in hepatocellular cancer

Caveolin-1 is the principal components of caveolae membranes, implicated in oncogenesis and angiogenesis. Until now, its expression and functional significance in hepatocellular carcinoma (HCC) are still unclear. In the present study, we demonstrated that expression of caveolin-1 was markedly upregulated in HCC patients. In addition, increased caveolin-1 expression correlated positively with the histological differentiation, portal venous invasion, hepatic venous invasion, intrahepatic metastases, and recurrence, suggesting a role for caveolin-1 in the progression of HCC. HepG2 cell line was transfected with pcDNA3.1/caveolin-1 to observe the significance of the change in caveolin-1 expression. We showed that caveolin-1 overexpression could not only protect HepG2 cells from apoptosis but also enhance its migration and invasion by upregulating MMP-2, MMP-9, and VEGF expressions. Collectively, our clinical and in vitro data indicate that the status of caveolin-1 expression may be one of causative factors for the invasion and poor prognosis in HCC.     

Nuclear expression of Y‐box binding protein‐1 is associated with poor prognosis in patients with pancreatic cancer and its knockdown inhibits tumor growth and metastasis in mice tumor models

The objective of this study was to examine the implication of Y‐box‐binding protein‐1 (YB‐1) for the aggressive phenotypes, prognosis and therapeutic target in pancreatic ductal adenocarcinoma (PDAC). YB‐1 expression in PDAC, pancreatic intraepithelial neoplasia (PanIN) and normal pancreas specimens was evaluated by immunohistochemistry, and its correlation with clinicopathological features was assessed in patients with PDAC. The effects of YB‐1 on proliferation, invasion and expressions of cell cycle‐related proteins and matrix metalloproteinases (MMPs) were analyzed by WST‐8, cell cycle and Matrigel invasion assays, Western blotting and quantitative RT‐PCR in PDAC cells transfected with YB‐1‐siRNAs. To verify the significance of YB‐1 for tumor progression in vivo, the growth and metastasis were monitored after intrasplenic implantation of ex vivo YB‐1 siRNA‐transfected PDAC cells, and YB‐1‐targeting antisense oligonucleotides were intravenously administered in nude mice harboring subcutaneous tumor. The intensity of YB‐1 expression and positivity of nuclear YB‐1 expression were higher in PDAC than PanIN and normal pancreatic tissues. Nuclear YB‐1 expression was significantly associated with dedifferentiation, lymphatic/venous invasion and unfavorable prognosis. YB‐1 knockdown inhibited cell proliferation via cell cycle arrest by S‐phase kinase‐associated protein 2 downregulation and consequent p27 accumulation, and decreased the invasion due to downregulated membranous‐type 2 MMP expression in PDAC cells. Tumor growth and liver metastasis formation were significantly suppressed in nude mice after implantation of YB‐1‐silenced PDAC cells, and the YB‐1 targeting antisense oligonucleotide significantly inhibited the growth of subcutaneous tumors. In conclusion, YB‐1 may be involved in aggressive natures of PDAC and a promising therapeutic target.     

Podocalyxin‐like protein,linked to poor prognosis of pancreatic cancers,promotes cell invasion by binding to gelsolin

The cell‐adhesion glycoprotein PODXL is associated with an aggressive tumor phenotype in several forms of cancer. Here, we report that high PODXL expression was an independent predictor of worse overall survival of pancreatic cancer patients, and that PODXL promoted pancreatic cancer cell motility and invasion by physically binding to the cytoskeletal protein gelsolin. Suppression of PODXL or gelsolin decreased membrane protrusions with abundant peripheral actin structures, and in turn inhibited cell motility and invasion. Transfection of a PODXL‐rescue construct renewed the expression of gelsolin bound to peripheral actin structures in cell protrusions, and abrogated the decreased cell protrusions caused by the knockdown of PODXL. Furthermore, transfection of a PODXL‐rescue construct into pancreatic cancer cells in which both PODXL and gelsolin were suppressed failed to increase the formation of the protrusions. Thus, PODXL enhances motility and invasiveness through an increase in gelsolin–actin interactions in cell protrusions.     

Increased FAT10 expression is related to poor prognosis in pancreatic ductal adenocarcinoma

It has been reported that FAT10 plays an important role in cell proliferation. Their activity is increased in malignant cells compared to benign cells. However, the clinical and functional significance of FAT10 expression has not been characterized previously in pancreatic ductal adenocarcinoma (PDAC). The purpose of this study was to assess FAT10 expression and to explore its contribution to PDAC. Real-time quantitative PCR was performed to examine FAT10 expression in 38 pairs of fresh frozen PDAC tissues and corresponding noncancerous tissues. Using immunohistochemistry, we performed a retrospective study of the FAT10 expression levels on 134 archival PDAC paraffin-embedded samples. The relationship between FAT10 mRNA expression and clinicopathological features was analyzed by appropriate statistics. Kaplan-Meier analysis and Cox proportional hazards regression models were used to investigate the correlation between FAT10 expression and prognosis of PDAC patients. The relative mRNA expression of FAT10 was significantly higher in PDAC tissues than in adjacent noncancerous tissues (P?<?0.001). By immunohistochemistry, the data revealed that high FAT10 expression was significantly correlated with clinical stage (P?<?0.001), histological differentiation (P?=?0.004), and lymph node metastasis (P?=?0.013). Consistent with these results, we found that high expression of FAT10 was significantly correlated with poor survival in PDAC patients (P?<?0.001). Furthermore, Cox regression analyses showed that FAT10 expression was an independent predictor of overall survival. In conclusion, this study confirmed the overexpression of FAT10 and its association with tumor progression in PDAC. It also provided the first evidence that FAT10 expression in PDAC was an independent prognostic factor of patients, which might be a potential diagnostic and therapeutic target of PDAC.     

Immune‐complex level of cofilin‐1 in sera is associated with cancer progression and poor prognosis in pancreatic cancer

Pancreatic ductal adenocarcinoma (PDAC) is one of the most lethal malignancies. To improve its outcome, reliable biomarkers are urgently needed. In this study, we aimed to elucidate the key molecules involved in PDAC progression using proteomics approaches. First, we undertook 2‐D electrophoresis to identify the proteins overexpressed in PDAC tissues. Following the analysis of agarose gel spots, cofilin‐1 was identified and verified as a candidate protein commonly upregulated in PDAC tissues. In immunohistochemistry, cofilin‐1 was strongly expressed in the cytoplasm of PDAC cells. Samples were divided into two groups based on the level of cofilin‐1 expression. The high expression group showed significantly higher incidence of hematogenous dissemination in relapsed patients than the low expression group (P = 0.0083). In in vitro experiments, knockdown of cofilin‐1 significantly decreased chemotaxis in PDAC cell lines. After we confirmed that cofilin‐1 was secreted from PDAC cells, we established a detection system for the immune‐complex of cofilin‐1 in sera. Using this system, we measured the IC levels of cofilin‐1 in sera and observed that the IC levels of cofilin‐1 in PDAC patients were higher than those in healthy volunteers and patients with pancreatitis (PDAC vs. healthy volunteers, P < 0.0001; PDAC vs. patients with pancreatitis, P < 0.026). Notably, the IC levels of cofilin‐1 showed a stepwise increase during PDAC progression (P = 0.0034), and high IC levels of cofilin‐1 indicated poor prognosis of patients after surgery (P = 0.039). These results suggest that the IC of cofilin‐1 in sera is a potentially attractive serum biomarker for the prognosis of PDAC.     

Secreted frizzled‐related protein‐5 is epigenetically downregulated and functions as a tumor suppressor in kidney cancer

Secreted frizzled‐related protein‐5 (sFRP‐5) has been identified as 1 of the secreted antagonists that bind Wnt protein. However, the functional significance of sFRP‐5 in renal cell cancer (RCC) has not been reported. We hypothesized that sFRP‐5 may be epigenetically downregulated through DNA methylation and histone modification and function as a tumor suppressor gene in RCC. Using tissue microarray and real‐time RT‐PCR, we found that sFRP‐5 was significantly downregulated in kidney cancer tissues and cell lines, respectively. DNA bisulfite sequencing of the sFRP‐5 promoter region in RCC cell lines showed it to be densely methylated, whereas there was few promoter methylation in normal kidney. The sFRP‐5 expression was restored and the acetylation of H3 and H4 histones associated with the sFRP‐5 promoter region were significantly increased after treatment with demethylation agent (5‐Aza‐dc) and histone deacetylase inhibitor (TSA). When RCC cells were transfected with the sFRP‐5 gene, significant inhibition of anchorage independent colony formation and cell invasion were observed compared to controls. The sFRP‐5 transfection also significantly induced apoptosis in RCC cells. In conclusion, this is the first report documenting that the sFRP‐5 is downregulated by promoter methylation and histone acetylation and functions as a tumor suppressor gene by inducing apoptosis in RCC cells.     

Frailty is associated with poor prognosis after resection for pancreatic cancer

International Journal of Clinical Oncology - With population aging, the number of frail patients with pancreatic cancer has increased. The Clinical Frailty Scale (CFS) is a simple and validated...     

High expression of Krüppel‐like factor 5 is associated with poor prognosis in patients with colorectal cancer

Krüppel‐like factor 5 (KLF5) plays an oncogenic role and has diverse functions in cancer cells. However, correlation between KLF5 and clinical outcome has not been determined in patients with colorectal cancer and colorectal liver metastasis. Herein, we analyzed 65 patients with colorectal cancer who developed colorectal liver metastasis. Clinical effects were assessed through immunohistochemical analysis of primary colorectal cancer lesions and metastatic liver lesions. High expression of KLF5 in these tissues correlated with the presence of vascular invasion, elevated serum carbohydrate antigen 19‐9 levels, large diameters of metastatic liver tumors, and poor prognosis following surgery. Multivariate analyses revealed that high expression of KLF5 was an independent prognostic factor. Increased expression of KLF5 in both colorectal cancer primaries and colorectal liver metastasis was significantly associated with shorter overall survival time and time to surgical failure. Krüppel‐like factor 5 expression positively correlated with Ki‐67 and c‐Myc expression in colorectal cancer tissues. In vitro experiments with colon cancer cell lines showed that siRNA knockdown of KLF5 inhibited cell proliferation. Western blot analyses revealed that knockdown of KLF5 expression reduced cyclin D1 and c‐Myc expression. It also impaired the stem cell‐like properties of cancer cells in tumorsphere formation assays. Furthermore, anoikis assay indicated that KLF5 contributed to anoikis resistance. High KLF5 expression is associated with poor prognosis in patients with colorectal cancer and liver metastasis by promoting cell proliferation and cancer stem cell‐like properties.     

Cell cycle‐related and expression‐elevated protein in tumor overexpression is associated with proliferation behaviors and poor prognosis in non‐small‐cell lung cancer

The cell cycle‐related and expression‐elevated protein in tumor (CREPT) is overexpressed in several human malignancies. However, the clinical relevance of CREPT expression and its biological role in non‐small‐cell lung cancer (NSCLC) remains unclear. In this study, we detected the expression of CREPT in both NSCLC tissues and cell lines by immunohistochemistry, Western blot analysis, and RT‐PCR. The correlation between CREPT expression and clinicopathologic features was analyzed in 271 NSCLC patients. The prognostic value of CREPT expression was evaluated by Kaplan–Meier analysis and Cox regression analysis. CREPT was overexpressed in Calu‐1 cell lines by using plasmid vector and its biological function was explored both in vitro and in vivo. We found that CREPT was significantly overexpressed in NSCLC compared with paired adjacent non‐tumor tissues, and the expression level of CREPT was correlated with tumor differentiation, lymph node metastasis, and clinical stage. Kaplan–Meier analysis showed that the recurrence‐free survival and overall survival of high CREPT expression groups were significantly shorter than those of the low CREPT expression group. Multivariate analysis identified that CREPT might be an independent biomarker for the prediction of NSCLC prognosis. Overexpression of CREPT increased cell proliferation and enhanced the migration and invasion ability of Calu‐1 cells (a human NSCLC cell line with relative low CRPET expression) in vitro. Moreover, CREPT overexpression promoted tumor growth in a nude mice model. These results suggest that CREPT is closely relevant to the proliferation of NSCLC cells and it might be a potential prognostic marker in NSCLC patients.     

Pyrophosphatase overexpression is associated with cell migration, invasion, and poor prognosis in gastric cancer

Inorganic pyrophosphatase (PPase) catalyzes the hydrolysis of pyrophosphate to form orthophosphate. Pyrophosphate can substitute for ATP under certain circumstances. We previously conducted a proteomic analysis to investigate tumor-specific protein expression in gastric cancer, and PPase was identified as a potential gastric tumor-specific marker; it was therefore selected for further study. Clinicopathological analysis, using proteomic analysis and immunohistochemistry, was used to validate PPase as a prognostic marker in gastric cancers. Proteomic analysis showed that PPase was overexpressed in patients with lymph node (LN) metastases and high tumor node metastasis (TNM) stages (p?<?0.05). Based on immunohistochemistry, patients whose tumors overexpressed PPase had higher T stages, LN metastasis, a higher TNM stage, a higher cancer recurrence rate, and shorter survival times than patients whose tumors exhibited PPase underexpression (p?<?0.05). Gain-of-function and loss-of-function approaches were employed to examine the malignant phenotypes of PPase-overexpressing or PPase-depleted cells. A decrease in PPase expression caused a significant decrease in gastric cancer cell migration and invasion in vitro, whereas forced overexpression of PPase enhanced migration but not invasion. Our findings indicate that PPase is involved in gastric tumor progression and that PPase may be a useful marker for poor prognosis of human gastric cancers.     

Connexin26 expression is associated with lymphatic vessel invasion and poor prognosis in human breast cancer

Purpose Cx26, which is a constituent of the connexin family, has recently been shown to promote metastasis through enhancing the vascular invasion in mouse melanoma cells. In this study, we have investigated whether or not Cx26 expression is associated with vascular invasion and recurrences in human breast cancers. Experimental design Cx26 expression was studied in 152 invasive breast cancers by immunohistochemistry. In order to investigate the blood vessel invasion and lymphatic vessel invasion with precision, immunohistochemical staining of blood vessels and lymphatic vessels was carried out using anti-CD34 and anti-D2-40 antibodies, respectively. Results Cx26 was positive in 51.3% (78/152) of the breast tumors. A statistically significant association was observed between Cx26 expression and large tumor size (P = 0.013) or high histological grade (P = 0.043). Frequency of blood vessel invasion was higher in Cx26-positive tumors (5.1%, 4/78) than in Cx26-negative tumors (1.4%, 1/74) though not statistically significant (P = 0.210). Lymphatic vessel invasion was significantly (P = 0.001) more frequent in Cx26-positive tumors (39.7%) than in Cx26-negative tumors (14.9%). Patients with Cx26-positive tumors showed a significantly (P < 0.001) poorer prognosis than those with Cx26-negative tumors. Multivariate analysis showed that Cx26 (P < 0.05) expression was an independent prognostic factor. Conclusions Cx26 expression is associated with lymphatic vessel invasion, large tumor size, high histological grade, and poor prognosis in human breast cancers. Cx26 seems to enhance the metastasis probably through promoting the lymphatic vessel invasion. Cx26 might be clinically useful as a new prognostic factor.     

高表达DNAJA1促进乳腺癌细胞增殖及侵袭且与患者的不良预后及化疗抵抗密切相关

目的:分析DNAJ热休克蛋白40家族成员A1［DNAJ heat shock protein 40 family（Hsp40) member A1,DNAJA1］在人乳腺癌组织中的表达及其与患者临床病理特征的关系,探讨DNAJA1对乳腺癌细胞增殖及侵袭的影响,揭示其与乳腺癌患者预后及化疗抵抗的关系。方法:免疫组织化学检测169例乳腺癌患者配对石蜡组织及120例接受新辅助化疗前穿刺活检石蜡组织中DNAJA1的表达情况。CCK-8、平板克隆、Transwell侵袭及细胞划痕实验检测DNAJA1对乳腺癌细胞增殖和侵袭的影响。结果:DNAJA1在原发灶及转移灶的乳腺癌组织中的表达明显高于癌旁组织（P＜0.001,P＜0.001）。临床病理分析发现,DNAJA1的高表达与分子分型、p53的突变和肿瘤复发密切相关。DNAJA1高表达还与患者的较短生存时间相关（P=0.023）。另外,DNAJA1在接受新辅助化疗的Miller-Payne（MP) 5级组患者的癌组织中表达明显低于其他组（P=0.000 4）。体外实验证实,敲低DNAJA1能明显抑制乳腺癌细胞的增殖和侵袭。结论:DNAJA1能促进乳腺癌细胞的增殖和侵袭,且DNAJA1在乳腺癌组织中高表达与患者不良预后及化疗抵抗相关,可作为预测患者预后及新辅助化疗效果的一个新靶点。