227 research outputs found
The role of Wnt-induced secreted proteins (WISPs) in gastric cancer
Introduction:
It has been recently shown that the WISP proteins(Wnt-inducted secreted proteins), a group of intra- and extra-cellular regulatory proteins, have been implicated in the initiation and progression of variety types of tumours including colorectal and breast cancer. However, the role of WISP proteins in gastric cancer (GC) cells and clinical implication in gastric cancer has not yet been fully
elucidated.
Materials and methods:
The expression of the WISP transcript and proteins in a cohort of GC patients was analysed using real-time quantitative PCR and immunohistochemistry, respectively. The expression of a panel of recognised EMT (epithelial-mesenchymal transition) markers were quantified (Q-PCR) in paired tumour and normal gastric tissues. WISP-2 knockdown sublines using anti-WISP-2 ribozyme transgenes were created in GC cell lines AGS and HGC27. Using the cell models and proteins extracted from gastric tissue samples, protein microarray was used to search for potential protein partners and signalling pathways involved with WISP-2. Subsequently, the biological functions, namely, cell growth, adhesion, migration and invasion, were studied. Potential mechanisms related with EMT, extracellular matrix and MMP (Matrix metalloproteinases) and signalling pathways
were investigated.
Results:
Expression of WISP-2 was frequently detected in GC tissues. Levels of WISP-2, not WISP-1 and WISP-3, was significantly correlated with early TNM staging and differentiation status. High levels of WISP-2 were associated with a favourable clinical outcome and survival of the patients. We also found that WISP-2 expression inversely correlated with Twist and Slug in the paired gastric samples. Knockdown of WISP-2 expression increased the rate of proliferation, migration and invasion of GC cells and influenced expression of EMT biomarkers including Twist, Slug and Ecadherin.Using an antibody based protein microarray, ERK, JNK as well as AKT proteins were
found to be co-precipiated with WISP-2 protein from human gastric tissue proteins. Furthermore, WISP-2 knockdown gastric cell lines also demonstrated a change in the ERK and JNK phophorylation. Mechanistically, WISP-2 suppressed GC cell metastasis through reversing epithelial-mesenchymal transition and suppressing the expression and activity of MMP-9 and MMP-2 via JNK and ERK. Cell motility analysis indicated that WISP-2 knockdown contributed to GC cellsā motility, an effect attenuated by PLC-Ī³ and JNK small inhibitors.
Conclusions:
WISP-2 transcript and protein expressions are inversely linked to disease progression and linked to the survival of patients with gastric cancer. WISP-2 has a profound influence on the migration and adhesion of gastric cancer cells and is a powerful factor to reverse the EMT process in these cells. These effects of WISP-2 are via its involvement in the ERK and JNK pathways, which in turn modulate the MMP activities. Together, WISP-2 is an important regulator of the cellular function and an important factor in the progression of gastric cancer. It acts as a potential tumour suppressor in gastric cancer
Association of Wnt1-inducible signaling pathway protein-1 with the proliferation, migration and invasion in gastric cancer cells
Wnt1-inducible signaling pathway protein-1 is a cysteine-rich protein that belongs to the CCN family, which has been implicated in mediating the occurrence and progression through distinct molecular mechanisms in several tumor types. However, the association of Wnt1-inducible signaling pathway protein-1 with gastric cancer and the related molecular mechanisms remain to be elucidated. Therefore, this study aimed to clarify the biological role of Wnt1-inducible signaling pathway protein-1 in the proliferation, migration, and invasion in gastric cancer cells and further investigated the associated molecular mechanism on these biological functions. We first detected the expression level of Wnt1-inducible signaling pathway protein-1 in gastric cancer, and the reverse transcription polymerase chain reaction have shown that Wnt1-inducible signaling pathway protein-1 expression levels were upregulated in gastric cancer tissues. The expression of Wnt1-inducible signaling pathway protein-1 in gastric cancer cell lines was also detected by quantitative real-time polymerase chain reaction and Western blotting. Furthermore, two gastric cancer cell lines with high expression of Wnt1-inducible signaling pathway protein-1 were selected to explore the biological function of Wnt1-inducible signaling pathway protein-1 in gastric cancer. Function assays indicated that knockdown of Wnt1-inducible signaling pathway protein-1 suppressed cell proliferation, migration, and invasion in BGC-823 and AGS gastric cancer cells. Further investigation of mechanisms suggested that cyclinD1 was identified as one of Wnt1-inducible signaling pathway protein-1 related genes to accelerate proliferation in gastric cancer cells. In addition, one pathway of Wnt1-inducible signaling pathway protein-1 induced migration and invasion was mainly through the enhancement of epithelial-to-mesenchymal transition progression. Taken together, our findings presented the first evidence that Wnt1-inducible signaling pathway protein-1 was upregulated in gastric cancer and acted as an oncogene by promoting proliferation, migration, and invasion in gastric cancer cells
Differential expression of CCN family members CYR611, CTGF and NOV in gastric cancer and their association with disease progression
CCN is an acronym for cysteine-rich protein 61 (CYR61), connective tissue growth factor (CTGF) and nephroblastoma overexpressed (NOV). Aberrations of certain CCN members including CYR61, CTGF, Wnt1-inducible signalling pathway protein (WISP)-1 and -3 have been reported in gastric cancer. The present study aimed to examine the clinical relevance of NOV along with CYR61 and CTGF in gastric cancer by analysing their transcript levels. CYR61, CTGF and NOV transcript expression in 324 gastric cancer samples with paired adjacent normal gastric tissues were determined using real-time quantitative PCR and the results were statistically analysed against patient clinicopathological data using SPSS software. NOV mRNA levels in gastric cancer tissues were significantly elevated when compared with levels in their paired adjacent non-cancerous tissues. Local advanced tumours with invasive expansion (T3 and T4) expressed higher levels of NOV (p=0.013) compared with the less invasive tumours (T1 and T2). CYR61 transcript levels were also significantly increased in gastric cancers compared with levels in the adjacent non cancerous tissues. Kaplan-Meier survival curves revealed that patients with CYR61-low transcript levels had longer overall survival (OS) (p=0.018) and disease-free survival (DFS) (p=0.015). NOV overexpression promoted the in vitro proliferation of AGS cells while the knockdown resulted in a reduced proliferation of HGC27 cells. A similar effect was observed for the invasion of these two gastric cancer cell lines. NOV expression was increased in gastric cancer which was associated with local invasion and distant metastases. Taken together, the expression of NOV and CYR61 was increased in gastric cancer. The elevated expression of CYR61 was associated with poorer survival. NOV promoted proliferation and invasion of gastric cancer cells. Further investigations may highlight their predictive and therapeutic potential in gastric cancer.Cancer Research Wales; Chinese Medical Research Scholarship of Cardiff UniversitySCI(E)[email protected]; [email protected]
VGOS: Voxel Grid Optimization for View Synthesis from Sparse Inputs
Neural Radiance Fields (NeRF) has shown great success in novel view synthesis
due to its state-of-the-art quality and flexibility. However, NeRF requires
dense input views (tens to hundreds) and a long training time (hours to days)
for a single scene to generate high-fidelity images. Although using the voxel
grids to represent the radiance field can significantly accelerate the
optimization process, we observe that for sparse inputs, the voxel grids are
more prone to overfitting to the training views and will have holes and
floaters, which leads to artifacts. In this paper, we propose VGOS, an approach
for fast (3-5 minutes) radiance field reconstruction from sparse inputs (3-10
views) to address these issues. To improve the performance of voxel-based
radiance field in sparse input scenarios, we propose two methods: (a) We
introduce an incremental voxel training strategy, which prevents overfitting by
suppressing the optimization of peripheral voxels in the early stage of
reconstruction. (b) We use several regularization techniques to smooth the
voxels, which avoids degenerate solutions. Experiments demonstrate that VGOS
achieves state-of-the-art performance for sparse inputs with super-fast
convergence. Code will be available at https://github.com/SJoJoK/VGOS.Comment: IJCAI 2023 Accepted (Main Track
Increased expression of Gremlin1 promotes proliferation and epithelial mesenchymal transition in gastric cancer cells and correlates with poor prognosis of patients with gastric cancer
Background/Aim: Gremlin1 (GREM1) plays an important role in certain malignancies by antagonising bone morphogenetic proteins and regulating angiogenesis directly/indirectly. The present study aimed to investigate the role of Gremlin1 in the development and progression of gastric cancer (GC). Materials and Methods: Expression of GREM1 in GCs was examined using quantitative real time PCR and The Cancer Genomic Atlas (TCGA) data. Influence on cellular functions was determined in both Gremlin1 knockdown and overexpression cell line models. Results: GREM1 expression was up-regulated in GCs, which was correlated with poorer survival. Increased GREM1 expression was significantly correlated with tumour growth/invasion and lymphatic metastasis. Gremlin1 promoted proliferation and tumourigenic capacity of GC cells in vitro. GREM1 expression was associated with epithelial mesenchymal transition (EMT), angiogenesis and lymphangiogenesis in GC. Conclusion: Increased GREM1 expression in GCs is associated with disease progression and poor prognosis in which EMT, angiogenesis and lymphangiogenesis are likely involved
Methylation status of individual CpG sites within Alu elements in the human genome and Alu hypomethylation in gastric carcinomas
<p>Abstract</p> <p>Background</p> <p><it>Alu </it>methylation is correlated with the overall level of DNA methylation and recombination activity of the genome. However, the maintenance and methylation status of each CpG site within <it>Alu </it>elements (<it>Alu</it>) and its methylation status have not well characterized. This information is useful for understanding natural status of <it>Alu </it>in the genome and helpful for developing an optimal assay to quantify <it>Alu </it>hypomethylation.</p> <p>Methods</p> <p>Bisulfite clone sequencing was carried out in 14 human gastric samples initially. A <it>Cac</it>8I COBRA-DHPLC assay was developed to detect methylated-<it>Alu </it>proportion in cell lines and 48 paired gastric carcinomas and 55 gastritis samples. DHPLC data were statistically interpreted using SPSS version 16.0.</p> <p>Results</p> <p>From the results of 427 <it>Alu </it>bisulfite clone sequences, we found that only 27.2% of CpG sites within <it>Alu </it>elements were preserved (4.6 of 17 analyzed CpGs, A ~ Q) and that 86.6% of remaining-CpGs were methylated. Deamination was the main reason for low preservation of methylation targets. A high correlation coefficient of methylation was observed between <it>Alu </it>clones and CpG site J (0.963), A (0.950), H (0.946), D (0.945). Comethylation of the sites H and J were used as an indicator of the proportion of methylated-<it>Alu </it>in a <it>Cac</it>8I COBRA-DHPLC assay. Validation studies showed that hypermethylation or hypomethylation of <it>Alu </it>elements in human cell lines could be detected sensitively by the assay after treatment with 5-aza-dC and M.<it>Sss</it>I, respectively. The proportion of methylated-<it>Alu </it>copies in gastric carcinomas (3.01%) was significantly lower than that in the corresponding normal samples (3.19%) and gastritis biopsies (3.23%).</p> <p>Conclusions</p> <p>Most <it>Alu </it>CpG sites are deaminated in the genome. 27% of <it>Alu </it>CpG sites represented in our amplification products. 87% of the remaining CpG sites are methylated. <it>Alu </it>hypomethylation in primary gastric carcinomas could be detected with the <it>Cac</it>8I COBRA-DHPLC assay quantitatively.</p
Inhibitory effects of Yangzheng Xiaoji on angiogenesis and the role of the focal adhesion kinase pathway
Angiogenesis is an essential event during the excessive growth and metastatic spread of solid tumours. Anti-angiogenic agents have become a new choice of therapy for patients with cancer. In the present study, we investigated the potential effect of Yangzheng Xiaoji, a traditional Chinese medicinal formula presently used in the treatment of several solid tumours including liver cancer and gastric cancer, on angiogenesis, in vitro. The human vascular endothelial cell line HECV was used. A Matrigel-based sandwich tubule formation assay was employed to assess in vitro angiogenesis, a colorimetric method for assessing in vitro cell growth. Electric cell-substrate impedance sensing (ECIS) was used to evaluate the adhesion and migration of endothelial cells. The effects on activation of focal adhesion kinase (FAK) were evaluated using western blotting and immunofluorescence methods. Yangzhen Xiaoji extract DME25 significantly inhibited tube formation (p=0.046 vs control). This was seen together with a concentration-dependent inhibition on cell-matrix adhesion and cellular migration. It was demonstrated that the focal adhesion kinase (FAK) inhibitor PF557328 had a significant synergistic effect on DME25-induced inhibition of cell adhesion, migration and tube formation. The study showed that DME25 inhibited the phosphorylation of FAK in endothelial cells. In conclusion, Yangzhen Xiaoji has a marked effect on angiogenesis, in vitro and that this effect is at least partly mediated by the focal adhesion kinase (FAK) pathway
Overall survival benefits of cancer drugs approved in China from 2005 to 2020
Importance: Of approximately 9 million patients with cancer in China in 2020, more than half were diagnosed with late-stage cancers. Recent regulatory reforms in China have focused on improving the availability of new cancer drugs. However, evidence on the clinical benefits of new cancer therapies authorized in China is not available. Objective: To characterize the clinical benefits of cancer drugs approved in China, as defined by the availability and magnitude of statistically significant overall survival (OS) results. Design, Setting, and Participants: This mixed-methods study comprising a systematic review and cross-sectional analysis identified antineoplastic agents approved in China between January 1, 2005, and December 31, 2020, using publicly available data and regulatory review documents issued by the National Medical Products Administration. The literature published up to June 30, 2021, was reviewed to collect results on end points used in pivotal trials supporting cancer drug approvals. Main Outcomes and Measures: The primary outcome measure was a documented statistically significant positive OS difference between a new cancer therapy and a comparator treatment. Secondary outcome measures were the magnitude of OS benefit and other primary efficacy measures in pivotal trials. Results: Between 2005 and 2020, 78 cancer drugs corresponding to 141 indications were authorized in China, including 20 drugs (25.6%) (for 30 indications) approved in China only. Of all indications, 26 (18.4%) were evaluated in single-arm or dose-optimization trials, most of which were authorized after 2017. By June 30, 2021, 34 drug indications (24.1%) had a documented lack of OS gain. For 68 indications (48.2%) that had documented evidence of OS benefit, the median magnitude of OS improvement was 4.1 (range, 1.0-35.0) months. After a median follow-up of 1.9 (range, 1.0-11.1) years from approval, OS data for 13 indications (9.2%) were either not reported or were still not mature. Fewer than one-third of cancer drug indications approved in China only had documented evidence of OS benefits (9 of 30 [30.0%]), whereas more than one-half of the cancer drug indications also available in the US or Europe had OS benefits (59 of 111 [53.1%]). Conclusions and Relevance: In this study, almost half of cancer drug indications approved in China had demonstrated OS gain. With the increase of cancer drug approvals based on single-arm trials or immature survival data in recent years, these findings highlight the need to routinely monitor the clinical benefits of new cancer therapies in Chin
Overexpression of EPHB4 Is associated with poor survival of patients with gastric cancer
Background: Increased expression of erythropoietin-producing human hepatoma (EPHB4) leads to enhanced cell migration, growth and adhesion in tumor cells. However, little is known regarding the effects of EPHB4 in gastric cancer. The present study aimed to examine the clinical relevance of EPHB4 and its association with the prognosis of gastric cancer. Materials and Methods: EPHB4 transcript expression in 324 gastric cancer samples with paired adjacent normal gastric tissues was determined using quantitative polymerase chain reaction and the results were statistically analyzed against patient clinicopathological data. AGS and HGC27 cell lines were transfected with EPHB4 siRNA and the effects examined by functional analysis. Results: EPHB4 mRNA levels in gastric cancer tissues were significantly elevated when compared to non-cancerous tissues (p=0.0110). Tissue samples from male patients exhibited lower expression than those from female patients (p=0.0110). Non-cardiac gastric tumors (fundus, corpus and pylorus) expressed a higher number of EPHB4 transcripts in comparison to cardiac gastric tumors (p<0.001). Increased expression of EPHB4 was significantly associated with poorer overall (p=0.0051) and progression-free (p=0.0262) survival. EPHB4 knockdown appeared to reduce post-wound migration of AGS cells (p=0.0057) and increase migration of HGC27 cells (p=0.0337). EPHB4 knockdown significantly increased adhesive ability in HGC27 (p<0.0001). Conclusion: The expression of EPHB4 was increased in gastric cancer and increased EPHB4 expression was correlated with poor survival. Knockdown of EPHB4 promoted adhesion and exerted diverse effects on migration of gastric cancer cells. Further investigations may highlight its predictive and therapeutic potential in gastric cancer
Psoriasin overexpression confers drug resistance to cisplatin by activating ERK in gastric cancer
Psoriasin, a member of the S100 multigenic family, which is aberrantly expressed in a variety of human tumors, is considered as an attractive molecular target for cancer treatment. The present study aimed to characterize the role of psoriasin in gastric cancer (GC), the associated pathways through which it contributes to cancer development and progression, and the effect of psoriasin on cellular response to pre-operative chemotherapy in patients with GC. Expression of psoriasin mRNA and protein were analyzed using quantitative polymerase chain reaction and immunohistochemistry of gastric cancer cohorts, respectively. Gastric cancer cell models with differential expression of psoriasin were generated using stable cell lines that overexpressed psoriasin. The in vitro biological functions of the cells in response to psoriasin overexpression and to chemotherapeutic agents were assessed using various cell-based assays. Psoriasin was overexpressed in patients with advanced GC, and high psoriasin levels led to poor clinical outcomes. Increasing psoriasin expression in GC cell lines promoted cell proliferation, migration and invasion in vitro. Furthermore, psoriasin overexpression caused alterations in the levels of epithelial-mesenchymal transition-associated proteins, and activated the extracellular signal-regulated kinase signaling pathway. Additionally, higher levels of psoriasin expression were significantly associated a lack of response to neoadjuvant chemotherapy in patients with GC. Psoriasin overexpression tended to decrease the sensitivity of GC cells to cisplatin, potentially by inhibiting apoptosis or increasing the S-phase population. Taken together, these results indicate that psoriasin may be a promising therapeutic target for GC treatment, and a potential molecular marker to predict patient response to pre-operative chemotherapy
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