Identification of prognostic immunophenotypic features in cancer stromal cells of high-grade neuroendocrine carcinomas of the lung

Purpose

The immunophenotypes of cancer stromal cells have been recognized as prognostic factors of cancer. The purpose of this study was to analyze the prognostic markers of high-grade neuroendocrine carcinomas of the lung (HGNEC; both small cell carcinoma and large cell neuroendocrine carcinoma) by examining the immunophenotypes of cancer stromal cells.

Materials and methods

One hundred and fifteen patients who underwent a complete resection of HGNEC were included in this study. We examined the presence of CD204-positive tumor-associated macrophages (TAMs), Foxp3-positive regulatory T cells (Tregs), and podoplanin-positive cancer-associated fibroblasts (CAFs) to evaluate the prognostic values of these markers.

Results

The number of CD204-positive TAMs and Foxp3-positive Tregs did not influence the overall survival (OS) or the relapse-free survival (RFS) of the patients. However, patients with podoplanin-positive CAFs had a significantly better prognosis than those with podoplanin-negative CAFs [OS: p = 0.002, RFS: p = 0.002, 5-year overall survival (5YR): 74 vs. 45 %]. According to subgroup analyses, patients with podoplanin-positive CAFs displayed a better prognosis for both small cell carcinoma (OS: p = 0.046, 5YR: 74 vs. 46 %) and large cell neuroendocrine carcinoma (OS: p = 0.020, 5YR: 74 vs. 45 %). Moreover, in multivariate analyses, the podoplanin status of the CAFs was shown to be a statistically significant independent predictor of recurrence.

Conclusion

The presence of podoplanin-positive CAFs had a favorable prognostic value, suggesting that the evaluation of podoplanin expression by CAFs would lead to a novel risk classification of patients.     

Egr-1 Promotes Cell Proliferation and Invasion by Increasing β-Catenin Expression in Gastric Cancer

Background

Abnormal expression of early growth response gene 1 (Egr-1) and β-catenin may play a crucial role in the development and progression of human cancer. However, little is known about the expression and underlying molecular mechanisms in which Egr-1 and β-catenin are involved in the development and progression of gastric cancer.

Aims

The purpose of this study was to elucidate the potential relationship between Egr-1 and β-catenin expression in gastric cancer, which contributes to finding new molecular carcinogenesis as a potential therapeutic target for gastric cancer.

Methods

In a sample of 102 cases of human gastric cancer, the expression of Egr-1 and β-catenin was detected using immunohistochemistry. Egr-1 gene was transfected into gastric cancer SGC7901 cells and its role in proliferation and cell invasion was detected by MTT assay, flow cytometry, wound-healing and transwell invasion assay. Western blot analysis was used to study the expression of β-catenin and cyclin D1 proteins.

Results

Upregulated Egr-1 and β-catenin protein expression were strongly correlated with cancer progression and depth of invasion in gastric cancer. β-catenin, present mainly in cytoplasmic and nucleus of gastric cancer cells, was also positively correlated with Egr-1 expression in gastric cancer. Furthermore, the overexpression of Egr-1 upregulated β-catenin expression level, promoted cell proliferation, increased cell population in S-phase and enhanced gastric cancer cell migration and invasion in vitro.

Conclusions

Egr-1 might contribute to gastric cancer proliferation and invasion through activation of the β-catenin signaling pathway.     

Lentivirus-delivered ZEB-1 small interfering RNA inhibits lung adenocarcinoma cell growth in vitro and in vivo

Purpose

To explore the relationship between the expression of ZEB1 gene and the proliferation ability of lung adenocarcinoma cells.

Methods

Immunohistochemistry, Western blot and Real-time PCR were used to detect the expression of ZEB1 gene in lung adenocarcinoma tissue and cell lines compared with adjacent noncancerous region and the human lung fibroblast cell HLF cells. The lentivirus RNA interference technique was used to knock down the expression of ZEB1 in lung adenocarcinoma A549 and H1299 cell lines. Cell cycle and cell apoptosis were measured by FCM assay. In vivo, four groups of 4-week-old nude mice were subcutaneously injected with the stably transfected (ZEB-si, scr-si) cells at a single site to investigate the effect of ZEB1-siRNA in the nude mice tumor growth. In situ apoptosis was detection by TUNEL assay.

Results

ZEB-1 was highly expressed in lung adenocarcinoma tissue and cell lines compared with adjacent noncancerous region and the human lung fibroblast cell HLF cells. ZEB1-siRNA could decrease lung adenocarcinoma cell proliferation by delaying S-phase entry and induce cell apoptosis, which led to the inhibition of the tumorigenicity of A549 and H1299 cell lines. Further investigation showed that injecting the ZEB1-siRNA cells into the nude mice could significantly decrease the tumor growth.

Conclusion

Knockdown of ZEB-1 expression by lentivirus-delivered siRNA may provide a novel therapeutic target for the treatment of lung cancer.     

AEG-1 Is a Target of Perifosine and Is Over-Expressed in Gastric Dysplasia and Cancers

Background

Perifosine, an alkylphospholipid, is an Akt inhibitor which inhibits the growth of diverse cancer cells. We have reported its inhibitory effects on the growth of gastric cancer cells recently, but its molecular mechanisms are still largely unknown.

Aims

The purpose of this study was to investigate the effect and regulatory mechanism of perifosine in gastric cancer.

Methods

Cell viability was determined by sulforhodamine B assay after transiently transfected with AEG-1 specific siRNAs. qRT-PCR and western blot assay were used to determine the mRNA expression and proteins levels of cell signaling molecules examined. Immunohistochemistry was used to detect the AEG-1 expression in 87 gastric carcinomas, 60 dysplasia, and 47 normal gastric mucosa.

Results

Perifosine decreased AEG-1 gene expression along with inhibition of Akt/GSK3β/C-MYC signaling pathway. Knockdown of AEG-1 using siRNA led to significant down-regulation of cyclin D1 expression at both mRNA level and protein level, and inhibited the growth of gastric cancer cells. AEG-1 expression was elevated in gastric dysplasia and cancer tissues compared to normal gastric mucosa (P < 0.01). AEG-1 over-expression correlated with diffuse type of gastric cancer and advanced tumor stages.

Conclusions

Perifosine inhibits the growth of gastric cancer cells possibly through inhibition of the Akt/GSK3β/C-MYC signaling pathway—mediated down-regulation of AEG-1 that subsequently down-regulated cyclin D1. AEG-1 may play an important role in the carcinogenesis and progression of gastric cancer and could be a therapeutic target of perifosine.     

Delivery of the co-expression plasmid pEndo-Si-Stat3 by attenuated Salmonella serovar typhimurium for prostate cancer treatment

Objectives

To investigate the therapeutic utility of an attenuated bacterium carrying a plasmid that co-expresses Endostatin, an inhibitor of tumor neovasculogenesis, and a shRNA that targets Stat3 to suppress prostate cancer growth.

Methods

Plasmid pEndo-Si-Stat3 was constructed and introduced into an attenuated strain of Salmonella enterica serovar typhimurium. The resultant recombinant bacterium was used as a vector to deliver the plasmid to tumor cells growing in vivo. Tumor-associated gene and protein expression changes were measured by using RT-PCR and Western blot analyses. Expression of Endostatin in tumor tissue was detected by ELISA. The presence of vector bacteria in tissues was monitored and tumor destruction was assessed by using TUNEL and H&E staining assays.

Results

Bacterially delivered pEndo-Si-Stat3 decreased Stat3 levels and increased Endostatin expression in mouse tumors, resulting in a significant suppression of tumor growth (P < 0.01). Expression of Bcl-2 and PCNA was down-regulated and Caspase3 expression was up-regulated to promote apoptosis of tumor cells.

Conclusions

Successful delivery by attenuated Salmonella of the combination therapeutic plasmid simultaneously knocked down the expression of Stat3 and resulted in over-expression of Endostatin, which synergistically inhibited prostate cancer growth.     

Long-Term Cisplatin Exposure Promotes Methylation of the OCT1 Gene in Human Esophageal Cancer Cells

Background

Cisplatin-based chemotherapy is widely used for treatment of a variety of human malignant solid and metastatic tumors, including esophageal cancer. However, the clinical effect of this drug is limited because of intrinsic and acquired resistance to it. Organic cation transporters (OCTs) are important in the cellular uptake of cisplatin.

Aim

Our objective was to test the hypothesis that cisplatin resistance is associated with alteration of expression of OCTs.

Methods

Levels of expression of OCTs in paired esophageal cancer and adjacent non-cancerous tissues were examined by use of immunohistochemistry.

Results

We found that OCT1 silencing impaired cisplatin-mediated apoptosis of esophageal cancer cells. The level of OCT1 mRNA in cisplatin-resistant cells was markedly reduced compared with parental cells. Promoter methylation of OCT1 was induced in cisplatin-resistant cells.

Conclusion

This study shows that long-term exposure to cisplatin promotes methylation of the OCT1 gene in human esophageal cancer cells, which in turn results in cisplatin resistance.     

Expression and clinical role of small glutamine-rich tetratricopeptide repeat (TPR)-containing protein alpha (SGTA) as a novel cell cycle protein in NSCLC

Purpose

A small glutamine-rich tetratricopeptide repeat-containing protein alpha (SGTA) is a 35 kDa protein involved in a number of biological processes. However, the role of SGTA in non-small-cell lung cancer (NSCLC) tumorigenesis has never been elucidated. The purpose of this study was to determine whether SGTA could serve as a biomarker for stratification and prediction of prognosis in NSCLC.

Methods

Small glutamine-rich tetratricopeptide repeat-containing protein alpha expression was evaluated by Western blot in 8 paired fresh lung cancer tissues and immunohistochemistry on 83 paraffin-embedded sections. The effect of SGTA was assessed by RNA interference in A549 cells. Serum starvation and refeeding, flow cytometry, CCK-8, and tunnel assays were performed.

Results

Small glutamine-rich tetratricopeptide repeat-containing protein alpha was highly expressed in NSCLC and significantly correlated with NSCLC histological differentiation, clinical stage, and Ki-67. Multivariate analysis indicated that SGTA was an independent prognostic factor for NSCLC patients’ survival. The present investigation demonstrated that suppression of SGTA expression resulted in a significant decline of proliferation in A549 cells. Besides, SGTA could abolish the toxicity of cisplatin in A549 cells.

Conclusions

These findings suggested that SGTA might play an important role in promoting the tumorigenesis of NSCLC, and thus be a promising therapeutic target to prevent NSCLC progression.     

Deguelin, an Akt Inhibitor, Down-Regulates NF-κB Signaling and Induces Apoptosis in Colon Cancer Cells and Inhibits Tumor Growth in Mice

Background

Deguelin, a naturally occurring rotenoid, is known to be an Akt inhibitor and to have an anti-tumor effect on several cancers.

Aims

This study was performed to elucidate the effect of deguelin on apoptotic pathways related to NF-κB signaling in colon cancer cells and on the anti-tumor effect in colon cancer xenograft mice.

Methods

We studied COLO 205 and HCT116 cells in the presence or absence of deguelin. NF-κB signaling was examined by real-time RT-PCR for interleukin (IL)-8, by Western blotting for IκB phosphorylation/degradation, and by the electrophoretic mobility shift assay. Cell death was determined by the MTT assay, and apoptosis by Annexin V-FITC staining and caspase-3 activity. We also assessed the expression of antiapoptotic and proapoptotic factors by use of RT-PCR. In colon cancer xenograft mice, we evaluated the effect of deguelin on inoculated tumor growth, and apoptotic index was measured by the in vivo TUNEL assay.

Results

Deguelin significantly inhibited IL-8 gene expression, IκB phosphorylation/degradation, and DNA binding activity of NF-κB in colon cancer cells. Deguelin induced cell death and apoptosis in colon cancer cells in a dose and time-dependent manner. Deguelin down-regulated expression of NF-κB-mediated antiapoptotic factors such as cFLIP, Bcl-2, and Bcl-X_L. In the colon cancer xenograft model, the volume of the tumor treated with deguelin was significantly lower than that of the control, and the apoptotic index for deguelin-treated mice was much higher.

Conclusion

Deguelin might be a potential therapeutic agent for treatment of colorectal cancer.     

Mina53, a novel c-Myc target gene, is frequently expressed in lung cancers and exerts oncogenic property in NIH/3T3 cells

Purpose

Mina53, whose expression is directly induced by c-Myc, is overexpressed in various cancers and plays an important role in cell growth. To clarify the involvement of Mina53 in lung cancers, we investigated its expression in human lung cancer tissues as well as in various lung cancer cell lines.

Methods

Mina53 expression was determined by real-time RT-PCR, western blotting, and immunohistochemistry using lung cancer cell lines, normal human bronchial epithelial cells, and lung cancer tissues. Biological effects of Mina53 were evaluated by soft agar colony formation assay and tumorigenicity in nude mice using Mina53-transfected NIH/3T3 cells. cDNA microarray analysis was performed to determine the gene alteration by Mina53 and confirmation was made using real-time RT-PCR with mina53 expression plasmid or mina53 shRNA-transfected NIH/3T3 cells.

Results

We observed that 62% of patients evidenced overexpression of Mina53 from the early clinical stages of lung cancer. Differences according to gender, smoking status, or histologic type were not statistically significant. Forced expression of Mina53 in NIH/3T3 cells induced cell transformation, and mina53-transfected NIH/3T3 clones produced tumors in nude mice, demonstrating that Mina53 has oncogenic potential. cDNA microarray revealed that 254 genes had altered expression in a mina53-transfected NIH/3T3 clone. Mina53 regulates several genes related to cell adhesion and metabolism, which have also been reported to be regulated by c-Myc. Genes regulated by Mina53, but not by c-Myc included cytokine/growth factor related genes such as EGFR, IL-6, and HGF.

Conclusion

Our results suggest that Mina53 plays an important role in carcinogenesis and may be a target for cancer prevention.     

Oxidative stress is closely associated with tumor angiogenesis of hepatocellular carcinoma

Background

Oxidative stress (OS) plays an important role in the progression of chronic liver disease and hepatocarcinogenesis. However, the role of OS in the progression of hepatocellular carcinoma (HCC) is unclear. The aim of this study was to assess whether OS promotes angiogenesis in HCC.

Methods

The expressions of vascular endothelial growth factor (VEGF), VEGF receptor2 (VEGFR2), and phosphorylated Akt were assessed, and microvessel density (MVD) and the cancer-associated fibroblast (CAF) population were examined by immunohistological staining in 55 HCC samples. The OS level in these tissues was assessed using 8-hydroxy-2??-deoxyguanosine (8-OHdG) and 4-hydroxy-2-nonenal (4-HNE) immunostaining, and an 8-OHdG enzyme-linked immunosorbent assay (ELISA). The expression and activation of angiogenic factors and the effect of growth stimulation of human umbilical vein endothelial cells (HUVECs) were also assessed in vitro, using HLE hepatoma-derived cells and conditioned medium with or without treatment with hydrogen peroxide (H₂O₂); a phosphoinositide 3-kinase (PI3K) inhibitor, wortmannin; and an anti-oxidative agent, N-acetyl-l-cysteine (NAC).

Results

A higher OS grade was significantly associated with higher MVD, VEGF expression, Akt activity, and OS grade of CAFs, but not with the percentage of the CAFpopulation in HCC tissues. Additionally, cancer cells constituted a major population of OS marker-positive cells in HCC tissues. In vitro, H₂O₂ treatment induced up-regulation of VEGF at both the mRNA and protein levels, activated Akt, and resulted in the proliferation of HUVECs; the addition of wortmannin and NAC counteracted the effects of OS.

Conclusions

OS enhances the malignant potential of HCC through the stimulation of angiogenesis by activation of the Akt-VEGF pathway.     

SEL1L, an UPR Response Protein, a Potential Marker of Colonic Cell Transformation

Background

SEL1L gene product is implicated in the endoplasmic reticulum (ER)-associated protein degradation and Unfolded Protein Response pathways. This gene and associated miRNAs have been indicated as predictive and prognostic markers of pancreatic cancer.

Aim

Explore the role of SEL1L in colorectal cancer (CRC) progression.

Methods

SEL1L expression was analysed immunohistochemically in 153 adenomas and 71 CRCs from African American and North Italian patients. The distribution of stained cells was determined by computing median and inter quartile range. The receiver operating characteristics plot was used as discriminate power of SEL1L expression, CRC diagnosis and the effects on patient survival.

Results

SEL1L was low in normal mucosa and confined to few scattered cells at the base crypt of the villi and in the foveolar glandular compartment. The highest levels were in Paneth cells within the lysosomes. The enterocytic progenitor cells and mature enterocytes showed less cytoplasmic staining. In CRCs, SEL1L expression significantly correlated with the progression from adenoma to carcinoma (P?=?0.0001) being stronger in well-to-moderately differentiated cancers. No correlation was found with other clinicopathological characteristics or ethnicity.

Conclusions

SEL1L expression is a potential CRC tissue biomarker since its expression is significantly higher in adenoma cells with respect to normal mucosa. The levels of expression decrease sensibly in undifferentiated CRC cancers. Interestingly, Paneth cells contain high levels of SEL1L protein that could indicate pre-neoplastic mucosa undergoing neoplastic transformation. Since SEL1L’s major function lies within ER stress and active ERAD response, it may identify CRCs with differentiated secretory phenotype and acute cellular stress.     

Expression and potential role of apolipoprotein D on the death–survival balance of human colorectal cancer cells under oxidative stress conditions

Purpose

Inverse correlations of apolipoprotein D (ApoD) expression with tumor growth have been shown, therefore proposing ApoD as a good prognostic marker for diverse cancer types, including colorectal cancer (CRC). Besides, ApoD expression is boosted upon oxidative stress (OS) in many pathological situations. This study aims at understanding the role of ApoD in the progression of human CRC.

Methods

Samples of CRC and distant normal tissue (n?=?51) were assayed for levels of lipid peroxidation, expression profile of OS-dependent genes, and protein expression. Three single-nucleotide polymorphisms in the ApoD gene were analyzed (n?=?139), with no significant associations found. Finally, we assayed the effect of ApoD in proliferation and apoptosis in the CRC HT-29 cell line.

Results

In CRC, lipid peroxides increase while ApoD messenger RNA and protein decrease through tumor progression, with a prominent decrease in stage I. In normal mucosa, ApoD protein is present in lamina propia and enteroendocrine cells. In CRC, ApoD expression is heterogeneous, with low expression in stromal cells commonly associated with high expression in the dysplastic epithelium. ApoD promoter is basally methylated in HT-29 cells but retains the ability to respond to OS. Exogenous addition of ApoD to HT-29 cells does not modify proliferation or apoptosis levels in control conditions, but it promotes apoptosis upon paraquat-induced OS.

Conclusion

Our results show ApoD as a gene responding to OS in the tumor microenvironment. Besides using ApoD as marker of initial stages of tumor progression, it can become a therapeutic tool promoting death of proliferating tumor cells suffering OS.     

Regenerating gene (REG) 1 alpha promotes pannus progression in patients with rheumatoid arthritis

Introduction

A protein analysis using mass spectrometry revealed the existence of serum proteins with significant quantitative changes after the administration of infliximab. Among these proteins, regenerating gene (REG) 1?? appears to be related to the pathogenesis of rheumatoid arthritis (RA). Therefore, the present study was conducted to examine the mechanism of REG1?? in RA disease progression.

Methods

Serum samples were collected from RA patients and normal healthy controls. REG1?? expression was evaluated by ELISA, RT-PCR, and indirect immunofluorescence microscopy. The functions of REG1?? on synovial fibroblasts with regard to apoptosis, receptor activator of NF-??B ligand (RANKL) expression, and cellar proliferation were evaluated using siRNA to inhibit the intrinsic REG1?? mRNA expression.

Results

The serum concentrations of REG1?? in RA patients were higher than in normal healthy controls. The high expression of REG1?? was also observed in the synovial tissue of RA patients compared to those of osteoarthropathy patients. In addition, tumor necrosis factor-?? (TNF-??) upregulated REG1?? expression in the synovial fibroblasts cell line (MH7A). Inhibition of REG1?? expression suppressed the induction of RANKL expression by TNF-??. Furthermore, exogenous recombinant REG1?? protein inhibited apoptosis and promoted cell proliferation in MH7A cells. These effects were abolished in the REG1??-siRNA MH7A cells.

Conclusion

The present data suggest that TNF-?? induces aberrant REG1?? expression and that REG1?? plays an important role in aberrant cell proliferation and RANKL expression of synovial fibroblasts, ultimately resulting in pannus formation. Restoration of normal physiological REG1?? expression may contribute to disease amelioration.     

RUNX3 is a prognostic marker and potential therapeutic target in human breast cancer

Purpose

To evaluate the role of RUNX3 in breast cancer pathogenesis, we examined the RUNX3 expression in breast cancer tissues and analyzed the correlation between RUNX3 expression and clinicopathologic variables and patients survival.

Methods

We evaluated the RUNX3 expression by immunohistochemistry using a tissue microarray containing 256 specimens of breast cancer patients. We also studied the role of RUNX3 in cell migration and invasion by performing cell migration and invasion assay. Differential expression of metastasis-related genes after RUNX3 restoration was analyzed using the Human Tumor Metastasis PCR Array.

Results

The RUNX3 expression was significantly correlated with breast cancer histology grade (P = 0.000), and low RUNX3 expression strongly correlated with worse 5-year overall and disease-specific survival rates (P = 0.000 and P = 0.001, respectively). Furthermore, we found that RUNX3 restoration suppressed breast cancer metastasis by controlling cell migration and invasion capacity. Finally, gene expression profiles of RUNX3-549 and Ctrl-549 cells showed matrix metalloproteinase-2 (MMP-2) was the most significant gene among the 84 metastasis-related genes influenced by RUNX3 reintroduction.

Conclusions

Reduced RUNX3 expression is significantly correlated with breast cancer progression and predicts worse survival. RUNX3 regulates breast cancer cell migration and invasion through the MMP-2 pathway.     

GDF3 inhibits the growth of breast cancer cells and promotes the apoptosis induced by Taxol

Purpose

The aim of this study is to investigate whether GDF3 is related to the progression of human breast cancer and the effects of GDF3 on breast cancer cells.

Methods

The expression of GDF3 in 24 breast cancer specimens paired with corresponding neighboring nontumorous tissue was studied by Western blot. Breast cancer cells were treated with different concentrations of recombinant human GDF3 protein. Using lentivirus containing sh-RNA, we knocked down the expression of GDF3. Soft agar assay was performed to explore the effects of GDF3 on colony formation. Different anti-tumor drugs dealt with MCF-7 cells stably expressing GDF3.

Results

We found that GDF3 expression level was significantly down-regulated in breast cancer tissues compared to the surrounding nontumorous tissues. GDF3 proteins could inhibit the proliferation of MCF-7 and T47D cells. We also found that the knockdown of GDF3 resulted in the promotion of colony formation and enhanced the ability of anchorage-independent cell growth in soft agar. Furthermore, overexpression of GDF3 could promote the apoptosis induced by Taxol.

Conclusions

Our data indicated that GDF3 expression is significantly decreased in human breast cancer tissues, and reconstitution of GDF3 in breast cancer may be a potential therapeutic approach to inhibit aggressive growth of breast cancer.     

miR-21 induces cell cycle at S phase and modulates cell proliferation by down-regulating hMSH2 in lung cancer

Purpose

MicroRNAs regulate critical genes associated with lung cancer. Human mutS homolog 2 (hMSH2), one of the core mismatch repair genes, is affected in lung cancer development. The aim of this study is to investigate the role of miR-21 in hMSH2 gene expression and the effect of miR-21 on cell proliferation and cell cycle in lung cancer.

Methods

The targets of miR-21 were predicted by a bioinformatics tool, and hMSH2 was validated as a direct target of miR-21 by luciferase activity assay. MiRNA mimics or inhibitors were used to stimulate or attenuate the effect of endogenous miR-21 on hMSH2 expression. MiR-21 and hMSH2 expressions were assessed with real-time RT-PCR and Western blotting. Cell cycle was determined by flow cytometry, and cell growth was analyzed by MTT assay and real-time cell analysis system.

Results

MiR-21 expression was inversely correlated with hMSH2 expression in human lung cancer cell lines. Further validation showed hMSH2 was directly regulated by miR-21. The up-regulation of miR-21 significantly promoted cell proliferation and revealed a higher proportion of cells at S phase. However, knockdown of miR-21 expression resulted in cell cycle arrest at G2/M phase and inhibited cell proliferation.

Conclusions

These data suggest miR-21 is a key regulator of hMSH2 and modulates cell cycle and proliferation by targeting hMSH2 in human lung cancer.