Calcipotriol abrogates cancer-associated fibroblast-derived IL-8-mediated oxaliplatin resistance in gastric cancer cells via blocking PI3K/Akt signaling.

Activation of vitamin D receptor (VDR) in cancer-associated fibroblasts (CAFs) has been implicated in hesitating tumor progression and chemoresistance of several human malignancies. Yet, the role of VDR in CAF-induced chemotherapy resistance of gastric cancer (GC) cells remains elusive. In this study we first conducted immunohistochemistry analysis on tissue microarrays including 88 pairs of GC and normal mucosa samples, and provided clinical evidence that VDR was mainly expressed in gastric mucous cells but almost invisible in CAFs, and VDR expression was negatively correlated with malignant clinical phenotype and advanced stages, low VDR expression confers to poor overall survival rate of patients with GC. In a co-culture system of primary CAFs and cancer cells, we showed that treatment of HGC-27 and AGS GC cells with VDR ligand calcipotriol (Cal, 500 nM) significantly inhibited CAF-induced oxaliplatin resistance. By using RNA-sequencing and Human Cytokine Antibody Array, we demonstrated that IL-8 secretion from CAFs induced oxaliplatin resistance via activating the PI3K/AKT pathway in GC, whereas Cal treatment greatly attenuated the tumor-supportive effect of CAF-derived IL-8 on GC cells. Taken together, this study verifies the specific localization of VDR in GC tissues and demonstrates that activation of VDR abrogates CAF-derived IL-8-mediated oxaliplatin resistance in GC via blocking PI3K/Akt signaling, suggesting vitamin D supplementation as a potential strategy of enhancing the anti-tumor effect of chemotherapy in GC.

Molecular signatures of tumor progression in pancreatic adenocarcinoma identified by energy metabolism characteristics.

BACKGROUND: In this study, we performed a molecular evaluation of primary pancreatic adenocarcinoma (PAAD) based on the comprehensive analysis of energy metabolism-related gene (EMRG) expression profiles. METHODS: Molecular subtypes were identified by nonnegative matrix clustering of 565 EMRGs. An overall survival (OS) predictive gene signature was developed and internally and externally validated based on three online PAAD datasets. Hub genes were identified in molecular subtypes by weighted gene correlation network analysis (WGCNA) coexpression algorithm analysis and considered as prognostic genes. LASSO cox regression was conducted to establish a robust prognostic gene model, a four-gene signature, which performed better in survival prediction than four previously reported models. In addition, a novel nomogram constructed by combining clinical features and the 4-gene signature showed high-confidence clinical utility. According to gene set enrichment analysis (GSEA), gene sets related to the high-risk group participate in the neuroactive ligand receptor interaction pathway. CONCLUSIONS: In summary, EMRG-based molecular subtypes and prognostic gene models may provide a novel research direction for patient stratification and trials of targeted therapies.

Pituitary tumor-transforming gene-1 serves as an independent prognostic biomarker for gastric cancer.

BACKGROUND: Pituitary tumor-transforming gene-1 (PTTG1) is a transcription factor that can affect transcriptional activity, angiogenesis, and cell senescence. We examined PTTG1 mRNA and protein expression in gastric cancer (GC) cell lines and tissues to determine its value as a biomarker for GC diagnosis and therapy. METHODS: PTTG1 mRNA expression from 78 GC cases and paired adjacent normal mucosa (PCR cohort) as well as from five gastric cell lines was assessed using qRT-PCR. Nuclear and cytoplasmic RNA were extracted from two gastric cell lines to determine PTTG1 mRNA localization. PTTG1 protein expression from 98 GC cases, their paired adjacent normal mucosa, and 23 gastric intraepithelial neoplasia (GIN) cases was examined using immunohistochemistry (IHC cohort). The correlation between PTTG1 mRNA and protein expression and GC clinicopathological parameters was analyzed. RESULTS: PTTG1 mRNA expression in GC tissues and cell lines was significantly increased compared with adjacent normal gastric mucosa and normal gastric mucous cell lines (p < 0.05). PTTG1 expression was nuclear and cytoplasmic, with higher cytoplasmic expression. PTTG1 immunostaining significantly differed in GC (95.66 ± 20.65), GIN (84.00 ± 34.16), and normal adjacent mucosa (28 ± 22.25) (p < 0.001). Multivariate Cox regression analysis revealed that PTTG1 mRNA and protein expression are independent prognostic factors for GC patient survival. CONCLUSION: Our results suggest that PTTG1 is a promising target for GC diagnosis and therapy.

Reciprocal repression between TUSC7 and miR-23b in gastric cancer.

Recently, long noncoding RNAs (lncRNAs) were demonstrated to play important regulatory roles in biological processes and cancer biology. However, the overall pathophysiological contribution of lncRNAs to gastric cancer (GC) remains largely unknown. In this study, differentially expressed lncRNAs in GC and paired adjacent normal tissue samples were identified by microarray and were validated using quantitative real-time polymerase chain reaction (qRT-PCR). One particular lncRNA, tumour suppressor candidate 7 (TUSC7), was analyzed in sequential large cohorts, and the Kaplan-Meier method with the log-rank test for comparisons was used to analyse the survival data. The results indicated that TUSC7 was downregulated in GC samples and was an independent prognostic indicator of disease-free survival (DFS) and disease-specific survival (DSS) in GC patients. Applying loss-of-function and gain-of-function approaches, we determined that TUSC7 suppressed tumour cell growth in vitro and in vivo. Furthermore, we showed that TUSC7 was a direct transcriptional target of p53 via interaction of p53 with the putative p53-response element in the upstream region of TUSC7. Finally, we demonstrated reciprocal repression between TUSC7 and miR-23b; in contrast to TUSC7, miR-23b promoted cell growth. The results indicated that TUSC7 is a p53-regulated tumour suppressor that acts in part by repressing miR-23b and that TUSC7 may be a key regulatory hub in GC.

Circulating CUDR, LSINCT-5 and PTENP1 long noncoding RNAs in sera distinguish patients with gastric cancer from healthy controls.

The examination of circulating nucleic acids (CNAs) is an emerging noninvasive diagnostic technique. However, it is unclear if serum long noncoding RNAs (lncRNAs) represent a novel marker to detect gastric cancer (GC). In this study, we measured 39 candidate cancer-associated lncRNAs by reverse transcription and quantitative polymerase chain reaction (RT-qPCR) in sera from 110 patients with GC, 106 age- and sex-matched healthy subjects and 15 patients with gastric peptic ulcer, markers were validated and assessed by RT-qPCR. The correlation of the expression levels of the candidate serum lncRNAs with clinical parameters of GC patients was performed. A three-lncRNA signature, including CUDR, LSINCT-5 and PTENP1, was identified that may be potential diagnostic marker for GC. The areas under the receiver operating characteristic (ROC) curve for this serum three-lncRNA signature were 0.920 and 0.829 for the two sets of serum samples. Moreover, a risk model for the serum three-lncRNA signature demonstrated that healthy samples can be distinguished from early GC samples. Three-lncRNA signature in serum was identified as diagnostic marker for GC. This work may facilitate the detection of GC and serve as the basis for further studies of the clinical value of serum lncRNAs in maintaining surveillance and forecasting prognosis.

Down-regulation of ncRAN, a long non-coding RNA, contributes to colorectal cancer cell migration and invasion and predicts poor overall survival for colorectal cancer patients.

Accumulating evidence has indicated that long non-coding RNAs (lncRNAs) play critical roles in regulating cellular processes, such as cell growth and apoptosis, as well as cancer progression and metastasis. ncRAN (non-coding RNA expressed in aggressive neuroblastoma) was previously shown to be dramatically up-regulated and associated with poor prognosis in human neuroblastoma. This lncRNA also plays an important role in bladder cancer growth and invasion. Colorectal cancer (CRC) progression typically follows a complex cascade from primary malignancy to distant metastasis, but whether the aberrant expression of ncRAN in CRC is associated with malignancy, metastasis or prognosis remains unknown. In this study, we demonstrated that ncRAN expression is significantly down-regulated in tumor tissue and CRC cell lines compared with adjacent normal tissue and a normal intestinal mucous cell line. Reduced expression of ncRAN was detected in poorly differentiated or undifferentiated tumors and in tumors with liver metastases. Kaplan-Meier analysis indicated that patients with lower ncRAN expression have a worse overall survival. Moreover, multivariate analysis revealed that decreased expression of ncRAN is an independent predictor of overall survival. Our experimental data indicated that ncRAN mediates the in vitro migration and invasion of CRC cells. Together, these results suggest that ncRAN might represent a novel prognostic indicator, a biomarker for the early detection of metastasis and a target for gene therapy in CRC.

Low expression of LOC285194 is associated with poor prognosis in colorectal cancer.

BACKGROUND: The long non-coding RNAs (lncRNAs) study has gradually become one of the hot topics in the field of RNA biology. One lncRNA which has attracted attention is LOC285194, a lncRNA demonstrated the potential tumor-suppressor role in osteosarcoma. The aim of this study was to examine the expression of LOC285194 in colorectal cancer (CRC) patients and to investigate the relationship between this lncRNA levels and existing clinicopathologic parameters and patient survival. METHODS: The expression of LOC285194 was detected by quantitative real-time polymerase chain reaction in pairs of tumorous and adjacent normal tissues of 81 colorectal cancer patients with a follow-up of 5 years, as well as in three colorectal cancer cell lines and normal intestinal mucous cell line. Then, we analyzed the potential relationship between this lncRNA levels in tumor tissues and existing clinicopathological features of CRC, and clinical outcome. RESULTS: The relative expression levels of LOC285194 was significantly lower in tumor tissues (p<0.001) and colorectal cancer cell lines compared with adjacent normal tissues and normal intestinal mucous cell line. In addition, low expression of LOC285194 was correlated with larger tumor size (p=0.015), higher tumor stage (p=0.034), and more distant metastasis (p=0.046). Kaplan-Meier analysis indicated that patients with low LOC285194 expression had a poor disease free survival (p=0.010). Moreover, multivariate analysis showed that decreased expression of LOC285194 was an independent predictor of disease-specific survival. CONCLUSION: Our data indicate that LOC285194 might be a novel prognostic indicator in colorectal cancer and may be a potential target for diagnosis and gene therapy.

Adult pancreatoblastoma: clinical features and Imaging findings.

The objective of this study was to illustrate the clinical, CT, MRI, and 18F-FDG PET/CT features of adult pancreatoblastoma, an extremely rare disease. In this study, the clinical and imaging features of seven adult patients with pathologically confirmed pancreatoblastoma were retrospectively analyzed. The following parameters were evaluated: size, location, shape, margination, solid-cystic ratio, CT attenuation values or signal intensity and contrast enhancement pattern. We also analyzed whether abnormal FDG uptake occurred during 18F-FDG PET/CT imaging. All seven patients were male (mean age 45 years; range 22-65 years). Six tumors were irregular in shape, exogenous, and grew outward from the pancreatic parenchyma, similar to branches growing from a tree trunk (85.7%). The tumor margins were clear in five patients (71.4%), and three tumors (42.9%) were encapsulated. Six tumors (71.4%) were solid, with homogeneous enhancement observed on contrast-enhanced CT and MRI. Dynamic-enhanced CT and MRI showed progressive enhancement for all tumors. On 18F-FDG PET/CT, one tumor exhibited abnormal FDG uptake, and two tumors exhibited no abnormal uptake (66.7%). In conclusion, adult pancreatoblastoma most commonly occurs in male patients, and it usually appears as an exophytic, irregular, and hypovascular mass with well-defined margins and progressive enhancement on CT and MRI. This type of tumor always grows out of the parenchyma of the pancreas, similar to branches growing outward from a tree trunk.

Hedgehog Interacting Protein 1 is a Prognostic Marker and Suppresses Cell Metastasis in Gastric Cancer.

Background: The gene Hedgehog interacting protein (HHIP) is a pivotal morphogen for multiple developmental processes. However, the expression and clinical correlation of HHIP in gastric cancer (GC) has not been fully investigated. Here, we aimed to explore the expression of HHIP in gastric cancer (GC) and evaluate its clinicopathological and functional correlations. Methods: The expression of HHIP mRNA was first determined in the Human Protein Atlas (HPA) and The Cancer Genome Atlas (TCGA) GC database and then validated by RT-qPCR (n = 41) and immunohistochemistry (IHC, n = 95) in a cohort of in-house GC patients and in 29 cases of gastric intraepithelial neoplasia (GIN). The clinicopathological and functional relationship of HHIP with GC were also analyzed. Results: We found that HHIP mRNA were significantly downregulated in GC in the TCGA and HPA databases, as well as in our in-house cohort (P < 0.05). HHIP mRNA is mainly located in the cell nucleus, while HHIP protein is mainly located in the cell cytoplasm. Moreover, the HHIP protein level in the GIN tissues was significantly higher than that in the GC tissues (P < 0.001) and significantly lower than that in adjacent normal controls (P < 0.001). In addition, low HHIP expression was correlated with lymphatic metastasis (P = 0.041), pTNM stage (P = 0.007) and nervous system invasion (P = 0.001). Furthermore, we observed strong positive correlations between HHIP protein expression and overall survival (P < 0.001) and disease-free survival (P = 0.027) in GC patients. HHIP protein expression was an independent prognostic factor for overall survival (P < 0.001). Functional experimental results showed that overexpression of HHIP attenuated the migration and invasion ability of GC cells (P < 0.01). Conclusion: HHIP may be a promising tumor metastatic-suppressor and prognostic biomarker for gastric cancer.

E2F1 induces LSINCT5 transcriptional activity and promotes gastric cancer progression by affecting the epithelial-mesenchymal transition.

BACKGROUND: Long noncoding RNAs (lncRNAs) have been shown to play important regulatory roles in human cancer. We previously verified that the lncRNA long stress-induced noncoding transcript 5 (LSINCT5) is overexpressed in gastric cancer (GC) cells and closely correlated with cell proliferation and patient prognosis. However, whether aberrant LSINCT5 expression has an important effect on GC progression is unclear, and the potential mechanisms remain unknown. In GC, E2F1 expression is also aberrant, but the biological functions of E2F1 are controversial, and the correlation between E2F1 and lncRNAs remains unknown. MATERIALS AND METHODS: Expression of LSINCT5 was analyzed in metastatic GC tissues compared with nonmetastatic tissues using quantitative real-time PCR (qRT-PCR) assays. Gain and loss of function approaches were used to investigate the biological role of LSINCT5 in GC cell migration and invasion. A computational screen of LSINCT5 promoter was conducted to search for transcription factor-binding sites. LSINCT5 promoter activities were examined by ChIP and luciferase reporter assays. qRT-PCR and western blotting assays were performed to detect the expression of multiple EMT markers in cells in which LSINCT5 was overexpressed or knocked down. RESULTS: An integrated quantitative analysis revealed that LSINCT5 was significantly over-expressed in metastatic GC tissues. Forced LSINCT5 expression promoted cell migration and invasion, whereas loss of LSINCT5 function decreased cell migration and invasion. Mechanistic investigations showed that LSINCT5 is a direct transcriptional target of E2F1. Moreover, LSINCT5 overexpression was found to play an important role in the epithelial-to-mesenchymal transition by regulating the expression of E-cadherin, N-cadherin, vimentin, and matrix metalloproteinase-2. CONCLUSION: These data suggest that E2F1-mediated activation of LSINCT5, a regulator of cell migration and invasion, constitute the mechanistic link between the E2F1-mediated pathway and lncRNA that regulates cell migration and invasion. Thus, LSINCT5 may be a target for new GC therapies.

A Positive Feedback Loop of lncRNA-PVT1 and FOXM1 Facilitates Gastric Cancer Growth and Invasion.

Purpose: The long, noncoding RNA (lncRNA) PVT1 is an important epigenetic regulator with a critical role in human tumors. Here, we aimed to investigate the clinical application and the potential molecular mechanisms of PVT1 in gastric cancer tumorigenesis and progression.Experimental Design: The expression level of PVT1 was determined by RT-qPCR analysis in 190 pairs of gastric cancer tissues and adjacent normal gastric mucosa tissues (ANT). The biologic functions of PVT1 were assessed by in vitro and in vivo functional experiments. RNA protein pull-down assays and LS/MS mass spectrometry analysis were performed to detect and identify the PVT1- interacting protein FOXM1. Protein-RNA immunoprecipitation assays were conducted to examine the interaction of FOXM1 and PVT1 Chromatin immunoprecipitation (ChIP) and luciferase analyses were utilized to identify the binding site of FOXM1 on the PVT1 promoter.Results: The lncRNA PVT1 was significantly upregulated in gastric cancer tissues compared with ANTs. High expression of PVT1 predicted poor prognosis in patients with gastric cancer. PVT1 enhanced gastric cancer cell proliferation and invasion in vitro and in vivoPVT1 directly bound FOXM1 protein and increased FOXM1 posttranslationally. Moreover, PVT1 is also a FOXM1-responsive lncRNA, and FOXM1 directly binds to the PVT1 promoter to activate its transcription. Finally, PVT1 fulfilled its oncogenic functions in a FOXM1-mediated manner.Conclusions: Our study suggests that PVT1 promotes tumor progression by interacting with FOXM1. PVT1 may be a valuable prognostic predictor for gastric cancer, and the positive feedback loop of PVT1-FOXM1 could be a therapeutic target in pharmacologic strategies. Clin Cancer Res; 23(8); 2071-80. ©2016 AACR.

Long non-coding RNA LSINCT5 predicts negative prognosis and exhibits oncogenic activity in gastric cancer.

Long non-coding RNAs (lncRNAs) are recently discovered RNA transcripts that are aberrantly expressed in many tumor types. Numerous studies have suggested that lncRNAs can be utilized for cancer diagnosis and prognosis. LSINCT5 (long stress-induced non-coding transcript 5) is dramatically upregulated in breast and ovarian cancer and affects cellular proliferation. However, the expression pattern of LSINCT5 in gastrointestinal cancer and the association between aberrant expression of LSINCT5 in gastrointestinal cancer and malignancy, metastasis, or prognosis remain unknown. LSINCT5 expression was detected in gastrointestinal cancer and paired adjacent normal tissue samples or cell lines using reverse transcription quantitative PCR (RT-qPCR). We also investigated the potential relationship between tumor LSINCT5 levels and clinicopathological features of gastrointestinal cancer. Finally, we assessed whether LSINCT5 influences in vitro cell proliferation. The expression of LSINCT5 is significantly upregulated in gastrointestinal cancer tissues and cell lines relative to their normal counterparts. In addition, increased LSINCT5 expression was correlated with a larger tumor size, deeper tumor depth, and advanced clinical stage. Kaplan-Meier analysis indicated that gastric cancer (GC) and colorectal cancer (CRC) patients with higher LSINCT5 expression levels have worse disease-free survival (DFS) and disease-specific survival (DSS) rates. Moreover, multivariate analysis revealed that increased expression of LSINCT5 is an independent predictor of DFS and DSS rates in GC patients. The ectopic expression of LSINCT5 in gastrointestinal cancer cell lines resulted in an increase in cellular proliferation; conversely, knock down of LSINCT5 significantly inhibited proliferation. These results suggest that LSINCT5 may represent a novel prognostic indicator and a target for gene therapy in gastrointestinal cancer.

Licochalcone A inhibits growth of gastric cancer cells by arresting cell cycle progression and inducing apoptosis.

The aim of this study was to determine the anticancer effects of seven licorice compounds in MKN-28, AGS, and MKN-45 gastric cancer cells and human gastric epithelium immortalized cells. We also explored the mechanism of action of licochalcone A (LCA), the most cytotoxic licorice compound, by analyzing its influence on cell cycle progression and apoptosis. The results indicated that LCA was the most cytotoxic licorice compound of those tested, and it inhibited gastric cancer cells growth in a dose-dependent manner, with an IC50 value of approximately 40µM. LCA affected gastric cancer cell viability by blocking cell cycle progression at the G2/M transition and inducing apoptosis. LCA treatment increased the expression of Rb and decreased the expression of cyclin A, cyclin B and MDM2 in MKN-28, AGS and MKN-45 cell lines. In addition, LCA-induced apoptosis by its effects on the expression of PARP, caspase-3, Bcl-2 and Bax. These data provide evidence that LCA has the potential to be used in the treatment of gastric cancer.

Pathologic research update of colorectal neuroendocrine tumors.

Colorectal neuroendocrine tumors (NETs) originate from neuroendocrine cells in the intestinal tract, and represent a small area within oncology, but one which has provided increasing new data during the past years. Although the World Health Organization has determined clinical and histological features to predict prognosis for such tumors, they may not be valid on an individual basis. We aim to give an overview of the recent findings with regard to pathology, molecular genetics and diagnosis of NETs.