Crosstalk between alternative splicing and inflammatory bowel disease: Basic mechanisms, biotechnological progresses and future perspectives

BACKGROUND

Alternative splicing (AS) is an omnipresent regulatory mechanism of gene expression that enables the generation of diverse splice isoforms from a single gene. Recently, AS events have gained considerable momentum in the pathogenesis of inflammatory bowel disease (IBD).

METHODS

Our review has summarized the complex process of RNA splicing, and firstly highlighted the potential involved molecules that target aberrant splicing events in IBD. The quantitative transcriptome analyses such as microarrays, next-generation sequencing (NGS) for AS events in IBD have been also discussed.

RESULTS

Available evidence suggests that some abnormal splicing RNAs can lead to multiple intestinal disorders during the onset of IBD as well as the progression to colitis-associated cancer (CAC), including gut microbiota perturbations, intestinal barrier dysfunctions, innate/adaptive immune dysregulations, pro-fibrosis activation and some other risk factors. Moreover, current data show that the advanced technologies, including microarrays and NGS, have been pioneeringly employed to screen the AS candidates and elucidate the potential regulatory mechanisms of IBD. Besides, other biotechnological progresses such as the applications of third-generation sequencing (TGS), single-cell RNA sequencing (scRNA-seq) and spatial transcriptomics (ST), will be desired with great expectations.

CONCLUSIONS

To our knowledge, the current review is the first one to evaluate the potential regulatory mechanisms of AS events in IBD. The expanding list of aberrantly spliced genes in IBD along with the developed technologies provide us new clues to how IBD develops, and how these important AS events can be explored for future treatment.

Long-read sequencing reveals the landscape of aberrant alternative splicing and novel therapeutic target in colorectal cancer

BACKGROUND

Alternative splicing complexity plays a vital role in carcinogenesis and cancer progression. Improved understanding of novel splicing events and the underlying regulatory mechanisms may contribute new insights into developing new therapeutic strategies for colorectal cancer (CRC).

METHODS

Here, we combined long-read sequencing technology with short-read RNA-seq methods to investigate the transcriptome complexity in CRC. By using experiment assays, we explored the function of newly identified splicing isoform TIMP1 Δ4-5. Moreover, a CRISPR/dCasRx-based strategy to induce the TIMP1 exon 4-5 exclusion was introduced to inhibit neoplasm growth.

RESULTS

A total of 90,703 transcripts were identified, of which > 62% were novel compared with current transcriptome annotations. These novel transcripts were more likely to be sample specific, expressed at relatively lower levels with more exons, and oncogenes displayed a characteristic to generate more transcripts in CRC. Clinical outcome data analysis showed that 1472 differentially expressed alternative splicing events (DEAS) were tightly associated with CRC patients' prognosis, and many novel isoforms were likely to be important determinants for patient survival. Among these, newly identified splicing isoform TIMP1 Δ4-5 was significantly downregulated in CRC. Further in vitro and in vivo assays demonstrated that ectopic expression of TIMP1 Δ4-5 significantly suppresses tumor cell growth and metastasis. Serine/arginine-rich splicing factor 1 (SRSF1) acts as a onco-splicing regulator through sustaining the inclusion of TIMP1 exon 4-5. Furthermore, CRISPR/dCasRx-based strategies designed to induce TIMP1 exon 4-5 exclusion have the potential to restrain the CRC growth.

CONCLUSIONS

This data provides a rich resource for deeper studies of gastrointestinal malignancies. Newly identified splicing isoform TIMP1 Δ4-5 plays an important role in mediating CRC progression and may be a potential therapy target in CRC.

Non-coding RNAs and colitis-associated cancer: Mechanisms and clinical applications

BACKGROUND

Colitis-associated cancer (CAC) is one of the most severe complications of inflammatory bowel disease (IBD), which has caused a worse survival rate in IBD patients. Although the exact aetiology and pathogenesis of CAC are not completely elucidated, evidence indicates that non-coding RNAs are closely involved and play a key role.

METHODS

This review aims to summarise the major findings of non-coding RNAs in the development of CAC and present the potential mechanistic links between non-coding RNAs and CAC pathogenesis. The results show that non-coding RNAs can hinder DNA mismatch repair proteins and obstruct chromosome passenger complexes to increase microsatellite instability and accumulate chromosomal instability, respectively. The data also suggest that DNA promoter methylation or RNA methylation modifications of non-coding RNA are the main mechanisms to regulate oncogene or tumour suppressor expression during the CAC progression. Other factors, including gut microbiota perturbations, immune dysregulation and barrier dysfunction, are also regulated and influenced by non-coding RNAs. Besides, non-coding RNAs as molecular managers are associated with multiple critical signalling pathways governing the initiation, progression and metastasis of CAC, including the janus kinase/signal transducer and activator of transcription (JAK/STAT), nuclear factor-kappa B (NF-κB), extracellular signal-regulated kinase (ERK), Toll-like receptor 4 (TLR4), Wnt/β-catenin and phosphatidylinositol 3-Kinase/Protein Kinase B (PI3K/AKT) pathways. In addition, non-coding RNAs can be detected in colon tissues or blood, and their aberrant expressions and diagnostic and prognostic roles are also discussed and confirmed in CAC patients.

CONCLUSIONS

It is believed that a deepening understanding of non-coding RNAs in CAC pathogenesis may prevent the progression to carcinogenesis, and will offer new effective therapies for CAC patients.

Identification and validation of crucial lnc-TRIM28-14 and hub genes promoting gastric cancer peritoneal metastasis

BACKGROUND

Gastric cancer peritoneal metastasis (GCPM) is an important cause of cancer-related deaths worldwide. Long non-coding RNAs (lncRNAs) play a key role in the regulation of GCPM, but the underlying mechanisms have not been elucidated.

METHODS

High-throughput RNA sequencing (RNA-seq) was performed on four groups of clinical specimens (non-metastatic gastric cancer primary tumor, adjacent normal gastric mucosal tissue, gastric cancer primary tumor with peritoneal metastasis and adjacent normal gastric mucosal tissue). After sequencing, many lncRNAs and mRNAs were screened for further Weighted Gene Co-expression Network Analysis (WGCNA). GCPM-related hub lncRNAs and genes were identified by cytoHubba and validated by Quantitative real-time PCR (qRT-PCR), Receiver operating characteristic curve (ROC) analysis and Kaplan-Meier survival analysis. GO, KEGG and GSEA showed GCPM-related pathways. Correlation analysis revealed the potential relationship between hub lncRNAs and genes.

RESULTS

By analyzing lncRNA expression data by WGCNA, we found that blue module was highly correlated with GCPM (r = 0.44, p = 0.04) and six lncRNAs involved in this module (DNM3OS, lnc-MFAP2-53, lnc-PPIAL4C-4, lnc-RFNG-1, lnc-TRIM28-14 and lnc-YARS2-4) were identified. We then performed qRT-PCR validation of gastric cancer specimens and found that the expression of lnc-RFNG-1 and lnc-TRIM28-14 was significantly increased in gastric cancer tissues with peritoneal metastasis. Kaplan-Meier survival analysis showed shorter overall survival time (OS) for gastric cancer patients with high expression of lnc-TRIM28-14. Receiver operating characteristic curve (ROC) analysis showed that lnc-TRIM28-14 could improve the sensitivity and specificity of GCPM diagnosis. In addition, we identified three key mRNAs (CD93, COL3A1 and COL4A1) associated with gastric cancer peritoneal metastasis through WGCNA analysis and clinical specimen validation. Moreover, there was a positive correlation between lnc-TRIM28-14 and the expression of CD93 and COL4A1 in gastric cancer peritoneal metastasis, suggesting a regulatory relationship between them. Subsequent GO, KEGG and GSEA analysis suggested that ECM-receptor interaction and focal adhesion were the hub pathways of GCPM.

CONCLUSION

In summary, lnc-RFNG-1, lnc-TRIM28-14, CD93, COL3A1 and COL4A1 could be novel tumor biomarkers and potential therapeutic targets for GCPM.

Long non-coding RNA H19X promotes tumorigenesis and metastasis of colorectal cancer through regulating the miR-503-5p/KANK1 axis

BACKGROUND

It has been well established that the long non-coding RNAs (lncRNAs) plays a critical role in tumor progression. However, the function of these transcripts and mechanisms responsible for their deregulation in colorectal cancer (CRC) remain to be investigated.

OBJECTIVE

To explore the potential effect and regulation mechanism of lncRNA H19X in colorectal cancer.

METHODS

We predicted and validated long non-coding RNA H19X from microarray data of colorectal cancer tissues. In addition, the biological behaviors of H19X and miR-503-5p on CRC were examined in vitro and in vivo, including MTT, colony formation assay, Hoechst33342 and transwell assay. The mRNA and protein levels of KN Motif and Ankyrin Repeat Domains 1 (KANK1) were analyzed by Quantitative real-time PCR (qRT-PCR), western blotting (WB) assay. Moreover, bioinformatics tools and dual-luciferase reporter assay were applied to demonstrate the relationship between KANK1 and miR-503-5p.

RESULTS

H19X was remarkably up-regulated in CRC tissues. Its expression related to tumor size (p = 0.041), lymph node metastasis (p = 0.037), distal metastasis (p = 0.028), advanced TNM stage (p = 0.034) and poor survival in CRC. H19X acted as an oncogenic lncRNA that induced CRC cell proliferation, invasion and metastasis. Through a number of functional studies, we found that H19X silencing inhibited the malignance phenotype of cancer cells through loss of miR-503-5p. Further studies demonstrated that miR-503-5p was involved in the progression of CRC by directly regulating the downstream target KANK1.

CONCLUSION

Collectively, the findings of the present study indicate H19X/miR-503-5p/KANK1 axis has critical role in the progression of colorectal cancer, providing an effective prognostic indicator and promising target in treatment of colorectal cancer.

PRKAR2A‐derived circular RNAs promote the malignant transformation of colitis and distinguish patients with colitis‐associated colorectal cancer

Background

Methods

Results

Conclusions

TSHZ3 functions as a tumor suppressor by DNA methylation in colorectal cancer

OBJECTIVE

Teashirt zinc finger homeobox 3 (TSHZ3) is currently reported to be aberrantly expressed in several tumors, but the detailed functions and epigenetic mechanisms of TSHZ3 in colorectal cancer (CRC) remain unclear.

MATERIALS AND METHODS

In this study, the TSHZ3 expression in 118 CRC and normal adjacent tissues (NATs) was evaluated, and the methylation status of the TSZH3 promoter region in CRC tissues and cell lines was also analyzed.

RESULTS

The results of PCR analysis showed that TSHZ3 was significantly down-regulated in CRC tissues, and patients with low TSHZ3 levels had a poorer 5-year overall survival (OS) rate. Analyzing the promoter sequence (-1000∼0) by MethPrimer, TSHZ3 promoter was found to harbor abundant of CpG islands. The methylation specific PCR (MSP) analysis presented a relatively hypermethylated status of THSZ3 promoter in CRC samples. The data of MSP and bisulfite sequencing PCR (BSP) also confirmed that CpG sites of TSHZ3 promoter were methylated in CRC cells, and the DNA methyltransferase (DNMT) inhibitor 5-aza-2'-deoxycytidine (5-Aza) could effectively restored the TSHZ3 expression in vitro. Functionally, the proliferation, apoptosis and metastasis of CRC cells were regulated by TSZH3 over-expression, and the suppressing effects of TSHZ3 in CRC were also confirmed in a xenograft mouse model.

CONLUSIONS

Our results indicated that promoter methylation was one of the mechanisms contributing to the down-regulation of TSHZ3 in CRC, and TSZH3 might served as a potential tumor suppressor gene in the development and progression of CRC.

Evidence of nigericin as a potential therapeutic candidate for cancers: A review

Emerging studies have shown that nigericin, an H⁺, K⁺ and Pb²⁺ ionophore, has exhibited a promising anti-cancer activity in various cancers. However, its anti-cancer mechanisms have not been fully elucidated. In this review, the recent progresses on the use of nigericin in human cancers have been summarized. By exchanging H⁺ and K⁺ across cell membranes, nigericin shows promising anti-cancer activities in in vitro and in vivo as a single agent or in combination with other anti-cancer drugs through decreasing intracellular pH (pHi). The underlying mechanisms of nigericin also include the inactivation of Wnt/β-catenin signals, blockade of Androgen Receptor (AR) signaling, and activation of Stress-Activated Protein Kinase/c-Jun N-terminal Kinase (SAPK/JNK) signaling pathways. In many cancers, nigericin is proved to specifically target putative Cancer Stem Cells (CSCs), and its synergistic effects on photodynamic therapy are also reported. Other mechanisms of nigericin including influencing the mitochondrial membrane potentials, inducing an increase in drug accumulation and autophagy, controlling insulin accumulation in nuclei, and increasing the cytotoxic activity of liposome-entrapped drugs, are also discussed. Notably, the potential adverse effects such as teratogenic effects, insulin resistance and eryptosis shall not be ignored. Taken together, these reports suggest that treatment of cancer cells with nigericin may offer a novel therapeutic strategy and future potential of translation to clinics.

Circular RNA profiling identifies circ102049 as a key regulator of colorectal liver metastasis

Circular RNA (circRNA) plays an essential role in the development and progression of various cancers. However, the functions and mechanisms of circRNA in colorectal liver metastasis have not been fully elucidated. We performed circRNA microarray analysis to screen differentially expressed circRNA in the pathology of colorectal liver metastasis. Quantitative real-time PCR was used to detect the expression of hsa_circ_102049 (circ102049) in colorectal cancer (CRC) samples. CRC cells were transfected with circ102049 overexpression vector or small interfering (si)RNA to assess the effects of circ102049 in vitro. Bioinformatics analysis, fluorescence in situ hybridization, RNA immunoprecipitation, RNA pull-down and luciferase reporter assays were conducted to confirm the relationship of circ102049, miR-761, miR-192-3p and FRAS1. The mechanism by which circ102049 recruits and distributes DGCR8 protein in the cytoplasm was also investigated. We found that circ102049 was highly expressed in primary CRC tumors with liver metastasis and closely correlated with the prognosis of patients with CRC. Circ102049 significantly enhanced the adhesion, migration and invasion abilities of CRC cells, and promoted CRC progression via a micro (mi)R-761/miR-192-3p-FRAS1-dependent mechanism. Notably, due to the distribution of DGCR8 protein, circ102049 may also indirectly reduce the levels of mature miR-761 and miR-192-3p in the cytoplasm. In addition, the role of circ102049 in promoting colorectal liver metastasis was confirmed in vivo. Our findings provide new evidence that circ102049 may be a potential prognostic factor in CRC, and that the circ102049-miR-761/miR-192-3p-FRAS1 axis may be an anti-metastatic target for CRC patients.

Molecular Screening for Nigericin Treatment in Pancreatic Cancer by High-Throughput RNA Sequencing

Objectives: Nigericin, an antibiotic derived from Streptomyces hygroscopicus, has been proved to exhibit promising anti-cancer effects on a variety of cancers. Our previous study investigated the potential anti-cancer properties in pancreatic cancer (PC), and demonstrated that nigericin could inhibit the cell viabilities in concentration- and time-dependent manners via differentially expressed circular RNAs (circRNAs). However, the knowledge of nigericin associated with long non-coding RNA (lncRNA) and mRNA in pancreatic cancer (PC) has not been studied. This study is to elucidate the underlying mechanism from the perspective of lncRNA and mRNA.

Methods: The continuously varying molecules (lncRNAs and mRNAs) were comprehensively screened by high-throughput RNA sequencing.

Results: Our data showed that 76 lncRNAs and 172 mRNAs were common differentially expressed in the nigericin anti-cancer process. Subsequently, the bioinformatics analyses, including Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis, coding and non-coding co-expression network, cis- and trans-regulation predictions and protein-protein interaction (PPI) network, were applied to annotate the potential regulatory mechanisms among these coding and non-coding RNAs during the nigericin anti-cancer process.

Conclusions: These findings provided new insight into the molecular mechanism of nigericin toward cancer cells, and suggested a possible clinical application in PC.

Hsa_circ_101555 functions as a competing endogenous RNA of miR-597-5p to promote colorectal cancer progression

CircRNAs have been reported to exert momentous roles in regulating pathophysiological process and guiding clinical diagnosis and treatment in colorectal cancer (CRC). However, there are still a lot of circRNAs that need to be unearthed. In this study, we evaluated the expression profile of circRNAs in 10 CRC tissues and their corresponding normal-appearing tissues (NATs) by microarray, and identified that hsa_circ_101555 (circ101555) was significantly up-regulated in tumor tissues and closely related to the prognosis of CRC patients. A specific close loop structure of circ101555 was described, which was generated by back-splicing of the host gene CSNK1G1 and showed greater stability than the linear RNA. The results in vitro and in vivo showed that silencing circ101555 expression significantly suppressed cell proliferation, induced apoptosis and impaired the DNA repair capacity of CRC cells, while rescue experiments suggested that down-expression of miR-597-5p could significantly attenuate the biological effects of circ101555 knockdown on CRC cells. Subsequent experiments in vitro, including double fluorescence in situ hybridization (D-FISH) analysis, RIP analysis and biotin-coupled probe pull down assay, confirmed that miR-597-5p was effectively enriched by circ101555, and circ101555 might serve as a sponge of miR-597-5p. Moreover, two putative oncogenes (CDK6 and RPA3) were identified as the miR-597-5p potential targets. Taken together, our results proved that circ101555 might function as a competing endogenous RNA of miR-597-5p to up-regulate CDK6 and RPA3 expression in CRC. Circ101555 could be a useful prognostic indicator in patients with CRC, and silence of circ101555 provided a new attractive therapeutic measure for CRC.

FOXM1 promotes the growth and metastasis of colorectal cancer via activation of β-catenin signaling pathway

Purpose

Our previous study proved that FOXM1 regulates colorectal cancer (CRC) cell metastasis through epithelial–mesenchymal transition program. The aim of this study is to further explore the underlying mechanism of FOXM1 in CRC.

Materials and methods

In this study, we detected the mRNA and protein expressions of FOXM1 and β-catenin in CRC tissues and their corresponding normal-appearing tissues (NATs) by quantitative reverse transcription-PCR and western blot analysis, respectively. Then the potential link between FOXM1 and β-catenin in CRC tissues was analyzed. Furthermore, we systematically analyzed the biological functions of FOXM1 in CRC cells after reconstitution of FOXM1 expression in vitro. Moreover, the mechanism of FOXM1-promoted CRC progression by improving β-catenin nuclear translocation was also discussed.

Results

Our data demonstrated that FOXM1 and β-catenin were upregulated in CRC tissues compared with the corresponding NATs (P<0.05). Clinicopathologic analysis revealed that increased FOXM1 (or β-catenin) expression positively correlated with some clinicopathologic features, such as tumor size, TNM stage, lymphatic metastasis, and distant metastasis (P<0.05). Meanwhile, the possible relationships between FOXM1 and β-catenin in CRC samples were evaluated using SPSS software, and a significant positive correlation was found (P<0.05). In vitro data demonstrate that elevated FOXM1 expression exerted oncogenic effects on CRC via activation of β-catenin signaling pathway. The inhibition of β-catenin by siRNAs significantly attenuates FOXM1-induced malignant activities.

Conclusion

The data suggested that FOXM1/β-catenin is critical for malignancy of CRC, which may constitute a potential therapeutic strategy for CRC.

Values of applying white blood cell counts in the prognostic evaluation of resectable colorectal cancer

The count and classification of white blood cells (WBCs) may be used as prognostic markers in certain types of cancer. The present study investigated the prognostic potential of the counts of WBCs, including lymphocytes (LYs), monocytes (MOs), neutrophils (NEs), eosinophils (EOs) and basophils (BAs), in the prognosis of resectable colorectal cancer. The present study recruited 153 resectable colorectal cancer cases retrospectively, which were pathologically confirmed. All patients were divided into two groups, according to the median value of LY (low LY, ≤1.632x109/l or high LY, >1.632x109/l), MO (low MO, ≤0.330x109/l or high MO, >0.330x109/l), NE (low NE, ≤3.600x109/l or high NE, >3.600x109/l), EO (low EO, ≤0.085x109/l or high EO, >0.085x109/l), BA (low BA, ≤0.010x109/l or high BA, >0.010x109/l), or WBC (low WBC, ≤5.780x109/l or high WBC, >5.780x109/l). To evaluate the alterations in WBC counts following surgery and adjuvant chemotherapy; all samples received oxiplatin and capecitabine (XELOX) for 6‑8 cycles or 5‑fluorouracil, leucovorin and oxaliplatin (mFOLFOX6) for 10‑12 cycles. XELOX included oxaliplatin administered intravenously at a dose of 130 mg/m2 on day 1 and 850‑1,250 mg/m2 capecitabine twice daily for days 1‑14, repeated every 3 weeks. mFOLFOX6 included oxaliplatin administered intravenously at a dose of 85 mg/m2, 400 mg/m2 leucovorin and 400 mg/m2 5‑FU on day 1 followed by 1,200 mg/m2/days continuous infusion for 2 days (in total, 2,400 mg/m2 over 46‑48 h), repeated every 2 weeks. The present study investigated the post/pre‑treatment of LY, MO, NE, EO, BA and WBC ratios (≤1 indicated that LY, MO, NE, EO, BA and WBC counts were not increased following therapy; whereas, >1 suggested increased counts). Kaplan‑Meier curves were constructed to demonstrate overall survival (OS). A multivariate and univariate logistic regression analyses model was employed to identify the independent risk factors. Low pre‑treatment BA counts were associated with larger tumor size (>5 cm); pre‑treatment BA levels were positively associated with OS. Surgery significantly decreased the count of BAs and increased the count of EOs; whereas, no effect was observed on LYs, MOs, NEs or WBCs. Adjuvant chemotherapy markedly decreased the counts of LY, NE and WBC; whereas, no notable effects on MOs, EOs or BAs were observed. Whole course treatment (surgery combined with adjuvant chemotherapy) significantly decreased the values of LY, NE and WBC; however, increased the value of EO; no effects on the MO or BA counts were observed. An increased post‑/pre‑treatment NE ratio suggested poorer prognosis. Multivariate Cox regression analysis revealed that sex, tumor size, pre‑treatment BA count and the post‑/pre‑treatment NE ratio were independent prognostic factors affecting OS. The results of the present study suggested that the pre‑treatment BA count and post‑/pre‑treatment NE ratio may be potential prognostic factors for resectable colorectal cancer.

Prognostic evaluation of patients with resectable lung cancer using systemic inflammatory response parameters

Lung cancer is one of the leading causes of cancer-associated mortality. C-reactive protein (CRP), albumin (ALB), globulin (GLB), lactate dehydrogenase (LDH), neutrophil-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) have been identified as general parameters for systemic inflammatory response (SIR). Furthermore, these parameters are also associated with tumor development and metastasis. The present study aimed to investigate the predictive values of these SIR parameters in patients with resectable lung cancer. In total, 101 patients with resectable lung cancer were recruited in the present study. The patients were divided into two groups according to the median value of pre-treatment CRP, ALB, GLB, LDH, NLR or PLR values. The post-/pre-treatment ratios were defined as the ratio of pre-treatment blood parameter values and the corresponding values obtained following therapy. A ratio of ≤1.1 indicated that the values were not increased, while a ratio of >1.1 suggested that the values were increased following treatment. Patients with lower pre-treatment ALB levels had poorer overall survival (OS) rates, whereas GLB, LDH, CRP, NLR or PLR levels were not associated with outcomes. Whole course treatment (surgery combined with adjuvant chemotherapy) significantly increased the value of ALB, but decreased the value of NLR, whereas it had no effect on the values of LDH, CRP or PLR. Post-/pre-treatment LDH and PLR were associated with outcomes. Post-/pre-treatment ALB, GLB, CRP and NLR were not associated with outcomes. Multivariate analysis revealed that a low pre-treatment ALB level and increased post-/pre-treatment PLR were independent risk factors affecting OS. The receiver operating characteristic curve analysis demonstrated that an ALB value of 47.850 g/l was considered to be the optimal cut-off value for prognosis; the sensitivity was 28.8% and specificity was 95.9%. It was suggested that the pre-treatment ALB and post-/pre-treatment PLR may be potential prognostic factors in resectable lung cancer.

Podocalyxin-like protein promotes gastric cancer progression through interacting with RUN and FYVE domain containing 1 protein

Podocalyxin‐like protein (PODXL), a transmembrane glycoprotein with anti‐adhesive properties, is associated with an aggressive tumor phenotype and poor prognosis of several cancers. To elucidate the biological significance of PODXL and its molecular mechanism in gastric cancer (GC), we investigated the expression of PODXL in GC samples and assessed its effects on biological behaviors and the related signaling pathways in vitro and in vivo. Moreover, the possible and closely interacted partners of PODXL were identified. Our data showed that the protein or mRNA level of PODXL was significantly upregulated in tissues or serum of GC patients compared with normal‐appearing tissues (NAT) or those of healthy volunteers. Overall survival (OS) curves showed that patients with high PODXL levels in tissues or serum had a worse 5‐year OS. In vitro, restoring PODXL expression promoted tumor progression by increasing cell proliferation, colony formation, wound healing, migration and invasion, as well as suppressing the apoptosis. Furthermore, the PI3K/AKT, NF‐κB and MAPK/ERK signaling pathways were activated. There was a significant positive correlation between PODXL and RUN and FYVE domain containing 1 (RUFY1) expression in tissues or serum. Subsequent mass spectrometry analysis, co‐immunoprecipitation assays and western blot analysis identified PODXL/RUFY1 complexes in GC cells, and silencing RUFY1 expression in GC cells significantly attenuated PODXL‐induced phenotypes and their underlying signaling pathways. Our results suggested that PODXL promoted GC progression via a RUFY1‐dependent signaling mechanism. New GC therapeutic opportunities through PODXL and targeting the PODXL/RUFY1 complex might improve cancer therapy.

FH535, a β-catenin pathway inhibitor, represses pancreatic cancer xenograft growth and angiogenesis

The WNT/β-catenin pathway plays an important role in pancreatic cancer carcinogenesis. We evaluated the correlation between aberrant β-catenin pathway activation and the prognosis pancreatic cancer, and the potential of applying the β-catenin pathway inhibitor FH535 to pancreatic cancer treatment. Meta-analysis and immunohistochemistry showed that abnormal β-catenin pathway activation was associated with unfavorable outcome. FH535 repressed pancreatic cancer xenograft growth in vivo. Gene Ontology (GO) analysis of microarray data indicated that target genes responding to FH535 participated in stemness maintenance. Real-time PCR and flow cytometry confirmed that FH535 downregulated CD24 and CD44, pancreatic cancer stem cell (CSC) markers, suggesting FH535 impairs pancreatic CSC stemness. GO analysis of β-catenin chromatin immunoprecipitation sequencing data identified angiogenesis-related gene regulation. Immunohistochemistry showed that higher microvessel density correlated with elevated nuclear β-catenin expression and unfavorable outcome. FH535 repressed the secretion of the proangiogenic cytokines vascular endothelial growth factor (VEGF), interleukin (IL)-6, IL-8, and tumor necrosis factor-α, and also inhibited angiogenesis in vitro and in vivo. Protein and mRNA microarrays revealed that FH535 downregulated the proangiogenic genes ANGPT2, VEGFR3, IFN-γ, PLAUR, THPO, TIMP1, and VEGF. FH535 not only represses pancreatic CSC stemness in vitro, but also remodels the tumor microenvironment by repressing angiogenesis, warranting further clinical investigation.

Nigericin Exerts Anticancer Effects on Human Colorectal Cancer Cells by Inhibiting Wnt/β-catenin Signaling Pathway

Nigericin, an antibiotic derived from Streptomyces hygroscopicus, which works by acting as an H⁺, K⁺, and Pb²⁺ ionophore, has exhibited promising anticancer activity. The main purpose of this study is to investigate its inhibitory effects on Wnt/β-catenin signaling pathway in colorectal cancer cells and clarify the underlying mechanism. We exposed two colorectal cancer lines (SW620 and KM12) to increasing concentrations of nigericin for different time periods and the 50% inhibiting concentration (IC₅₀) values were evaluated. Our data showed that nigericin treatment significantly reduced tumor cell proliferation in dose- and time-dependent manners in colorectal cancer cells. The subsequent experiments in vitro and in vivo implied that nigericin could significantly suppress the tumor growth, migration, and invasion, and induce the apoptosis of colorectal cancer cells. Our results of Western blot and immunofluorescence assay showed that nigericin could suppress the Wnt/β-catenin signaling pathway in colorectal cancer cells with dose-dependent increased expressions of downstream effectors and target proteins. To further elucidate the inhibitory effects of nigericin via a β-catenin-dependent signaling mechanism, we established the stably β-catenin overexpression colorectal cancer cells. Western blot, SuperTOPFlash luciferase reporter, and immunoprecipitation assays all confirmed β-catenin as a critical intermediary and player in Wnt/β-catenin pathway, and nigericin exerted anticancer effects on colorectal cancer cells by directly targeting the β-catenin destruction complex. These results suggested that Wnt/β-catenin signaling might have an essential role in colorectal cancer progression. Nigericin targeting Wnt/β-catenin signaling might provide new insight into the molecular mechanism of nigericin toward cancer cells, and suggest possible clinical application in colorectal cancer. Mol Cancer Ther; 17(5); 952-65. ©2018 AACR.

Ginsenoside Rg3 targets cancer stem cells and tumor angiogenesis to inhibit colorectal cancer progression in vivo

Anti-angiogenic therapy has been successfully applied to treat colorectal cancer (CRC). Ginsenoside Rg3, derived from the Chinese herb ginseng, has anti-vascularization effects and can inhibit tumor growth and metastasis, and can sensitize cancer cells to chemotherapy. Therefore, in the present study, we investigated whether Rg3 could be appropriate for CRC treatment. Growth of CRC cells was assessed by an MTT (methyl thiazolyl tetrazolium) assay in vitro and using orthotopic xenograft models in vivo. mRNA expression was evaluated using real-time PCR. Protein levels were tested by western blotting, flow cytometry and immunohistochemistry. Migration was determined using a wound-healing assay. Stemness was further confirmed using a plate clone formation assay. We found that Rg3 repressed the growth and stemness of CRC cells both in vitro and in vivo. Rg3 also impaired the migration of CRC cells in vitro. Rg3 downregulated the expressions of angiogenesis-related genes, and repressed the vascularization of CRC xenografts. In addition, Rg3 strengthened the cytotoxicity of 5-Fluorouracil and oxaliplatin against orthotopic xenografts in vivo. Moreover, Rg3 downregulated the expressions of B7-H1 and B7-H3, high expressions of which were associated with reduced overall survival (OS) of CRC patients. Hence, Rg3 not only repressed the growth and stemness of CRC cells, but could also remodel the tumor microenvironment through repressing angiogenesis and promoting antitumor immunity. Therefore, Rg3 could be a novel therapeutic for the CRC treatment.

Neutrophil/lymphocyte ratio is a more sensitive systemic inflammatory response biomarker than platelet/lymphocyte ratio in the prognosis evaluation of unresectable pancreatic cancer

Multiple cancers arise from sites of infection, chronic irritation, and inflammation. It has been widely accepted that pancreatic cancer is an inflammation-driven cancer. In this study, we investigated the application value of systemic inflammatory markers, neutrophil to lymphocyte ratio (NLR) and platelet to lymphocyte ratio (PLR), in the prediction of chemotherapy response and prognosis in patients with late pancreatic cancer. 122 patients with inoperable pancreatic cancers were included and separated into two groups according to median values of NLR or PLR (NLR low:<3.81 or NLR high:≥3.81, and PLR low:<142.14 or PLR high≥142.14, respectively). Baseline NLR and PLR levels were significantly higher in pancreatic cancer patients compared with the healthy subjects. Neither of the baseline NLR or PLR levels could predict outcomes. Patients with low baseline level of NLR, but not PLR, had better responses to chemotherapy. Changes in NLR, but not PLR levels, were associated with the therapeutic efficacy. Patients who stayed in or dropped into the low NLR level subgroup after first-line chemotherapy had better responses, comparing to those stayed in or jumped into the high NLR level group. No similar results could be observed when the PLR level was investigated. Therefore, NLR is a more sensitive biomarker than PLR in the prediction of chemotherapy response of patients.

Update on the role of endothelial cells in trauma

PURPOSE

This review gives an overview of physiological processes, mainly regarding vascular endothelial cells and their important role in hemostasis, information processing, and communication during trauma. An insight is given into molecules and cells involved in the first innate immune response through to the behavior of endothelial cells in developing trauma. The goal of this review is to show the overlap of crucial factors related to the endothelium and the development of trauma.

METHODS

A systemic literature search was performed using Google scholar and PubMed.

RESULTS

The results of the literature search showed that the endothelium, especially the vascular endothelium, is involved in various cellular and subcellular pathways of activation, suppression, and transfer of information. A variety of molecules and cells are orchestrated, subsequently the endothelium gets in contact with a traumatizing event.

CONCLUSION

The endothelium is one of the first barriers that comes into contact with exo- and endogenous trauma-related signals and is a pivotal point in activating subsequent pathways and cascades by transfer of information.

The Role of Tumor Associated Macrophages in the Tumor Microenvironment: Mechanism and Functions

During tumor progression, several types of inflammatory cells are recruited into the tumor site, where they participate in tumor-associated inflammation, such as fibroblasts, granulocytes, lymphocytes and macrophages. Macrophages infiltrating into the tumor microenvironment are termed tumorassociated macrophages (TAMs). In response to multiple stimuli, macrophages undergo recruitment and polarization, and play an important role in further tumor development. In this article, we present a review of the mechanism of macrophage' recruitment, and the role that TAMs play in promoting immunosuppression, tumor progress and metastasis, as well as chemoresistance and future therapeutic strategies.

Clinical Significance of miR-1826 as a Novel Prognostic Biomarker in Colorectal Cancer

Several reports indicated that aberrant miR-1826 was involved in the initiation and progression of malignancies. However, the clinical significance of miR-1826 in human colorectal cancer (CRC) has not been addressed. The aim of this study was to evaluate the expression and clinical significance of miR-1826 in CRC. We detected miR-1826 expressions by quantitative real.time PCR (qRT-PCR) in 72 CRC tissues, adjacent non.tumor tissues (NATs) and five CRC cell lines, and found that miR-1826 expression in CRC tissues was higher than that in NATs (p<0.05). High miR-1826 expression was significantly associated with some clinicopathologic features such as regional lymph node metastasis (p=0.018), advanced TNM clinical stage (p=0.004), which led to a poor overall survival rate in CRC patients (p=0.032). Our further studies in vitro also demonstrated that miR-1826 inhibitor could effectively suppress the cell proliferation, promote apoptosis and induce G0/G1 cell cycle arrest in CRC cells (p<0.05). Meanwhile, the abilities of cell invasion and migration were effectively suppressed by miR-1826 inhibitor (p<0.05). These findings strongly suggested that miR-1826 played a critical role in the initiation and progression of CRC. Up-regulation of miR-1826 might serve as a novel prognostic marker of CRC and could be a potential target for CRC therapies.

Molecular Mechanisms of Anti-cancer Activities of &#946;-elemene: Targeting Hallmarks of Cancer

Increasing knowledge on the hallmark characteristics of cancer and tumor pharmacology has promoted the introduction of phytochemicals, such as traditional Chinese medicine (TCM) in cancer therapy, which modulate numerous molecular targets and exert anticancer activities. β-elemene, an active and non-toxic compound isolated from the Chinese medicinal herb Rhizoma Zedoariae, has been explored as a potent anti-cancer agent against multiple cancers in extensive clinical trials and experimental research in vivo and in vitro. β-elemene exerts therapeutic potential via modulation of core hallmark capabilities of cancer by suppressing proliferative signaling, such as MAPK and PI3K/Akt/mTOR pathway, inducing cell death, up-regulating growth suppressors, deactivating invasion and metastasis and interacting replicative immortality and attenuating angiogenesis. Recent studies have significantly improved our understanding of anti-cancer activities and underlying molecular mechanisms of this Chinese medicine. This review presents these novel findings regarding the unique properties of β-elemene as an agent for cancer treatment, with an emphasis on multi-targeting biological and molecular regulation.

Circulating miR-1826 in plasma correlates with circulating tumor cells and is a prognostic marker in colorectal cancer

Our previous study showed that miR-1826 was a newly identified oncogenic non-coding RNA in colorectal cancer. But the potential relationship between miR-1826 and tumor metastasis has not been fully elucidated. The purpose of this study was to evaluate the clinical significance of circulating miR-1826 and its possible associations with circulating tumor cells in colorectal cancer. Our results first found that serum miR-1826 was significantly upregulated in colorectal cancer patients, compared with that in healthy volunteers ( p = 0.003). Similar results were also found in colorectal cancer with distant metastasis ( p = 0.001) and advanced colorectal cancer ( p < 0.001) patients, respectively. Clinicopathological analysis implied that circulating miR-1826 was positively associated with pT stage ( p = 0.026), lymphatic metastasis ( p = 0.034), distant metastasis ( p = 0.012), and tumor-node-metastasis stage ( p = 0.020). Besides, our univariate and multivariate analyses demonstrated that high serum miR-1826 expression could act as a prognostic and independent factor for overall survival of colorectal cancer patients ( p < 0.05), which led to a poorer 5-year overall survival rate ( p = 0.025). The area under the curve value of circulating miR-1826 was up to 0.848 ± 0.043, which strongly suggested serum miR-1826 as an effective diagnostic biomarker in colorectal cancer patients ( p < 0.001). Our subsequent experiments demonstrated that patients with high level of circulating tumor cells showed a higher level of miR-1826 expression, compared with the circulating tumor cell-negative patients ( p = 0.011). Similar results also showed that the amount of circulating tumor cells in high miR-1826 group was significantly higher than that in low miR-1826 group ( p = 0.001). Furthermore, the relationship between serum miR-1826 and circulating tumor cells was analyzed using SPSS software and a significant logarithmic relationship was found, which meant that circulating miR-1826 closely correlated with the amount of circulating tumor cells in colorectal cancer patient serum ( r = 0.283, p < 0.01). Our findings strongly suggested that serum miR-1826 could serve as an effective and non-invasive biomarker for diagnosis and prognosis of colorectal cancer. Circulating miR-1826 may be an important target in colorectal cancer therapy.

Hypoxia Induces Multidrug Resistance via Enhancement of Epidermal Growth Factor-Like Domain 7 Expression in Non-Small Lung Cancer Cells

Chemotherapy is widely used in non-small cell lung cancer (NSCLC) treatment, yet multidrug resistance (MDR) is a major chemotherapeutic obstacle in both resectable and advanced NSCLC. Epidermal growth factor-like domain 7 (EGFL7), also known as vascular endothelial stain, is an endothelial cell-derived secreted factor that regulates vascular tube formulation. The aim of this study was to investigate the potential relationships between EGFL7 and MDR in NSCLC cells. We first obtained the CDDP-based MDR phenotype cell line A549/CDDP by repeated exposure to a proper concentration of CDDP (cisplatin) from original A549 cells. These A549/CDDP cells, which maintained relative high levels of EGFL7 and P-glycoprotein (P-gp), were resistant to other chemotherapy drugs, such as carboplatin (CBP), paclitaxel (TAX), and gemcitabine (GEM) (p < 0.05). We also found that hypoxia significantly reduced the chemosensitivity of NSCLC cells, and hypoxia-induced MDR was mediated by P-gp and EGFL7 (p < 0.05). EGFL7 was veryy relevant to NSCLC cell MDR, and downregulation of EGFL7 could significantly increase the chemosensitivity of NSCLC cells (p < 0.05). Thus, our findings first indicate that hypoxia induced NSCLC cell MDR at least partly by enhancing the expression of EGFL7 protein. EGFL7 might be a feasible target for reversing hypoxia-mediated MDR in NSCLC cells and a promising biomarker for predicting the development of MDR in NSCLC patients on chemotherapy.

TNF-α sensitizes chemotherapy and radiotherapy against breast cancer cells

Purpose

Despite new developments in cancer therapy, chemotherapy and radiotherapy remain the cornerstone of breast cancer treatment. Therefore, finding ways to reduce the toxicity and increase sensitivity is particularly important. Tumor necrosis factor alpha (TNF-α) exerts multiple functions in cell proliferation, differentiation and apoptosis. In the present study, we investigated whether TNF-α could enhance the effect of chemotherapy and radiotherapy against breast cancer cells.

Methods

Cell growth was determined by MTT assay in vitro, and by using nude mouse tumor xenograft model in vivo. Cell cycle and apoptosis/necrosis were evaluated by flow cytometry. DNA damage was visualized by phospho-Histone H2A.X staining. mRNA expression was assessed by using real-time PCR. Protein expression was tested by Western blot assay.

Results

TNF-α strengthened the cytotoxicity of docetaxel, 5-FU and cisplatin against breast cancer cells both in vitro and in vivo. TNF-α activated NF-κB pathway and dependently up-regulated expressions of CyclinD1, CyclinD2, CyclinE, CDK2, CDK4 and CDK6, the key regulators participating in G1→S phase transition. As a result, TNF-α drove cells out of quiescent G0/G1 phase, entering vulnerable proliferating phases. Treatment of TNF-α brought more DNA damage after Cs¹³⁷-irradiation and strengthened G2/M and S phase cell cycle arrest induced by docetaxel and cisplatin respectively. Moreover, the up-regulation of RIP3 (a necroptosis marker) by 5-FU, and the activation of RIP3 by TNF-α, synergistically triggered necroptosis (programmed necrosis). Knockdown of RIP3 attenuated the synergetic effect of TNF-α and 5-FU.

Conclusion

TNF-α presented radiotherapy- and chemotherapy-sensitizing effects against breast cancer cells.

Characterization of blunt chest trauma in a long-term porcine model of severe multiple trauma

Chest trauma has a significant relevance on outcome after severe trauma. Clinically, impaired lung function typically occurs within 72 hours after trauma. However, the underlying pathophysiological mechanisms are still not fully elucidated. Therefore, we aimed to establish an experimental long-term model to investigate physiological, morphologic and inflammatory changes, after severe trauma. Male pigs (sus scrofa) sustained severe trauma (including unilateral chest trauma, femur fracture, liver laceration and hemorrhagic shock). Additionally, non-injured animals served as sham controls. Chest trauma resulted in severe lung damage on both CT and histological analyses. Furthermore, severe inflammation with a systemic increase of IL-6 (p = 0.0305) and a local increase of IL-8 in BAL (p = 0.0009) was observed. The pO₂/FiO₂ ratio in trauma animals decreased over the observation period (p < 0.0001) but not in the sham group (p = 0.2967). Electrical Impedance Tomography (EIT) revealed differences between the traumatized and healthy lung (p < 0.0001). In conclusion, a clinically relevant, long-term model of blunt chest trauma with concomitant injuries has been developed. This reproducible model allows to examine local and systemic consequences of trauma and is valid for investigation of potential diagnostic or therapeutic options. In this context, EIT might represent a radiation-free method for bedside diagnostics.

Inflammatory stimuli promote growth and invasion of pancreatic cancer cells through NF-κB pathway dependent repression of PP2Ac

Previous studies have indicated that inflammatory stimulation represses protein phosphatase 2A (PP2A), a well-known tumor suppressor. However, whether PP2A repression participates in pancreatic cancer progression has not been verified. We used lipopolysaccharide (LPS) and macrophage-conditioned medium (MCM) to establish in vitro inflammation models, and investigated whether inflammatory stimuli affect pancreatic cancer cell growth and invasion PP2A catalytic subunit (PP2Ac)-dependently. Via nude mouse models of orthotopic tumor xenografts and dibutyltin dichloride (DBTC)-induced chronic pancreatitis, we evaluated the effect of an inflammatory microenvironment on PP2Ac expression in vivo. We cloned the PP2Acα and PP2Acβ isoform promoters to investigate the PP2Ac transcriptional regulation mechanisms. MCM accelerated pancreatic cancer cell growth; MCM and LPS promoted cell invasion. DBTC promoted xenograft growth and metastasis, induced tumor-associated macrophage infiltration, promoted angiogenesis, activated the nuclear factor-κB (NF-κB) pathway, and repressed PP2Ac expression. In vitro, LPS and MCM downregulated PP2Ac mRNA and protein. PP2Acα overexpression attenuated JNK, ERK, PKC, and IKK phosphorylation, and impaired LPS/MCM-stimulated cell invasion and MCM-promoted cell growth. LPS and MCM activated the NF-κB pathway in vitro. LPS and MCM induced IKK and IκB phosphorylation, leading to p65/RelA nuclear translocation and transcriptional activation. Overexpression of the dominant negative forms of IKKα attenuated LPS and MCM downregulation of PP2Ac, suggesting inflammatory stimuli repress PP2Ac expression NF-κB pathway-dependently. Luciferase reporter gene assay verified that LPS and MCM downregulated PP2Ac transcription through an NF-κB-dependent pathway. Our study presents a new mechanism in inflammation-driven cancer progression through NF-κB pathway-dependent PP2Ac repression.

SCYL1-BP1 affects cell cycle arrest in human hepatocellular carcinoma cells via Cyclin F and RRM2

The cell cycle is regulated via important biological mechanisms. Controlled expression of cell cycle regulatory proteins is crucial to maintain cell cycle progression. However, unbalanced protein expression leads to many diseases, such as cancer. Previous research suggests that SCYL1-BP1 function might be related to cell cycle progression and SCYL1-BP1 dysfunction to diseases through undefined mechanisms. In this research, an unbiased yeast two-hybrid screen was used to find protein(s) with potential biological relevance to SCYL1-BP1 function, and a novel interaction was recognized between SCYL1-BP1 and Cyclin F. This interaction was chosen as a paradigm to study SCYL1-BP1 function in cell cycle progression and its possible role in tumorigenesis. We found that SCYL1-BP1 binds to Cyclin F both in vivo and in vitro. SCYL1-BP1 overexpression promoted expression of the CCNF gene and simultaneously delayed Cyclin F protein degradation. SCYL1-BP1 knockdown reduced the expression of endogenous Cyclin F. It was also demonstrated in functional assays that SCYL1-BP1 overexpression induces G2/M arrest in cultured liver cells. Furthermore, SCYL1-BP1 sustained RRM2 protein expression by reducing its ubiquitination. Thus, we propose that SCYL1- BP1 affects the cell cycle through increasing steady state levels of Cyclin F and RRM2 proteins, thus constituting a dual regulatory circuit. This study provides a possible mechanism for SCYL1-BP1-mediated cell cycle regulation and related diseases.

miRNA-101 Suppresses Epithelial-to-Mesenchymal Transition by Targeting HMGA2 in Pancreatic Cancer Cells

miR-101 is an outstanding tumor suppressor in various cancers, while its role in pancreatic cancer (PC) is still unknown. The aim of this study was to investigate the role of miR-101 in epithelial-to-mesenchymal transition (EMT) and its clinical relevance in PC. Our data showed that the miR-101 expression was significantly decreased in human PC tissues, compared to non-tumor counterparts (p<0.05), which was reversely correlated to clinical characteristics, including lymph node metastasis, more venous infiltration, higher expression of CA19-9 and TNM stage (p<0.05). Low miR-101 expression was also confirmed to be associated with a poorer overall survival rate in PC patients (p<0.05). We identified high-mobility group AT-hook 2 (HMGA2) gene as a putative target of miR-101 in PC by bioinformatics analysis, dual luciferase activity and western blot assay, and found that miR-101 could specifically target the HMGA2 3'-untranslated region (3'-UTR) (p<0.05). Knockdown of HMGA2 reversed EMT resembling that of miR-101 over-expression. An inverse correlation between miR-101 and HMGA2 was observed in patients with PC (p<0.05). Taken together, our findings speculated that miR-101 might act as an inhibiting factor in EMT process in PC and up-regulation of miR-101 might be considered as a potentially key molecular treatment strategy for PC patients.

miR-203 suppresses the proliferation and metastasis of hepatocellular carcinoma by targeting oncogene ADAM9 and oncogenic long non-coding RNA HULC

MicroRNAs (miRNAs) have been integrated into tumorigenic programs by regulating genes at post-transcriptional level. Long non-coding RNAs (lncRNAs) are novel targets for miRNAs. Here, we reported that miR-203 down-regulation was closely linked to advanced clinical features and poor overall survival (OS) of patients with hepatocellular carcinoma. We also confirmed that miR-203 and oncogene ADAM9 (a disintegrin and metalloproteinase 9)/oncogenic long non-coding RNA HULC (highly up-regulated in liver cancer) were inversely expressed in hepatocellular carcinoma (HCC) tissues or cell lines. More intriguingly, up-regulation of miR-203 diminished the expression of ADAM9 and HULC in HCC cancer cells. Over-expression of miR-203 could markedly inhibit cell proliferation, invasion and induce cell apoptosis. Furthermore, we identified that miR-203 modulated ADAM9 and HULC in a novel post-transcriptional regulatory mechanism. Over-expression of HULC partly rescued the miR-203-mediated antitumor effects. These results suggested that miR-203 played tumor suppressive roles by downregulating ADAM9 and HULC and indicated its potential application in cancer treatment.

MicroRNA-183 Functions As an Oncogene by Regulating PDCD4 in Gastric Cancer

MicroRNA-183 (miR-183) has recently been identified to be implicated in a variety of critical processes in multiple human malignancies, and its fuction has been poorly characterized in gastric cancer (GC). Here we reported that miR-183 was markedly over-expressed in GC and its up-regulation was markedly associated with GC clinicopathologicalcharacters. Endogenous miR-183 was inhibited in GC cells, which dramatically attenuated cell proliferation, colony formation, migration, invasion and adhesion and enhancedGC cells apoptosis in vitro. Furthermore, in this study we demonstrated that the tumor suppressor gene PDCD4 was a target of miR-183 in GC. Collectively, these observations showed that miR-183 maybe function as an oncogene by regulating GC cell proliferation, apoptosis and metastasis and the oncogenic effect of miR-183 may relate the direct targeting PDCD4.

Prognostic Value and Clinicopathological Differences of Bmi1 in Gastric Cancer: A Meta-analysis

B cell-specific Moloney murine leukemia virus integration site 1 (Bmi1) was identified as a biomarker of cancer stem cells, and over-expression of Bmi1 might enhance tumor aggressive clinical behavior in gastric cancer (GC). Our aim of this meta-analysis is to investigate the prognostic role and clinicopathological differences of Bmi1 in GC patients. A total of 6 studies up to September 2014 were included in our study. Our results showed that there were no relationships between Bmi1 expression and the gender (pooled OR=0.87, 95%CI=0.66-1.14, P=0.319, fixed effect), age (pooled OR=1.22, 95%CI=0.95-1.59, P=0.126, fixed effect) and differentiation (pooled OR=1.15, 95%CI=0.71-1.86, P=0.582, random effect) in GC patients. But high Bmi1 expression was significantly correlated with the clinical stage (pooled OR=3.04, 95%CI=1.31-7.07, P=0.010, random effect), tumor size (pooled OR=2.01, 95%CI=1.14-3.55, P=0.016, random effect), T classification (pooled OR=2.79, 95%CI=1.94-4.03, P<0.001, fixed effect), lymph node metastasis (pooled OR=2.24, 95%CI=1.47-3.39, P<0.001, random effect) and distant metastasis (pooled OR=5.05, 95%CI=1.29-19.70, P=0.020, random effect), and led to a poor overall survival (OS) in GC patients (RR=3.38, 95%CI=2.43-4.69, P<0.001, fixed effect). These findings suggested that Bmi1 might serve as a novel and effective prognostic biomarker in GC, and could be a promising emerging molecular target in GC therapy.

Lapatinib resistance in HER2+ cancers: latest findings and new concepts on molecular mechanisms

In the era of new and mostly effective molecular targeted therapies, human epidermal growth factor receptor 2 positive (HER2+) cancers are still intractable diseases. Lapatinib, a dual epidermal growth factor receptor (EGFR) and HER2 tyrosine kinase inhibitor, has greatly improved breast cancer prognosis in recent years after the initial introduction of trastuzumab (Herceptin). However, clinical evidence indicates the existence of both primary unresponsiveness and secondary lapatinib resistance, which leads to the failure of this agent in HER2+ cancer patients. It remains a major clinical challenge to target the oncogenic pathways with drugs having low resistance. Multiple pathways are involved in the occurrence of lapatinib resistance, including the pathways of receptor tyrosine kinase, non-receptor tyrosine kinase, autophagy, apoptosis, microRNA, cancer stem cell, tumor metabolism, cell cycle, and heat shock protein. Moreover, understanding the relationship among these mechanisms may contribute to future tumor combination therapies. Therefore, it is of urgent necessity to elucidate the precise mechanisms of lapatinib resistance and improve the therapeutic use of this agent in clinic. The present review, in the hope of providing further scientific support for molecular targeted therapies in HER2+ cancers, discusses about the latest findings and new concepts on molecular mechanisms underlying lapatinib resistance.

Long noncoding RNA OR3A4 promotes metastasis and tumorigenicity in gastric cancer

The contribution of long noncoding RNAs (lncRNAs) to metastasis of gastric cancer remains largely unknown. We used microarray analysis to identify lncRNAs differentially expressed between normal gastric tissues and gastric cancer tissues and validated these differences in quantitative real-time (qRT)-PCR experiments. The expression levels of lncRNA olfactory receptor, family 3, subfamily A, member 4 (OR3A4) were significantly associated with lymphatic metastasis, the depth of cancer invasion, and distal metastasis in 130 paired gastric cancer tissues. The effects of OR3A4 were assessed by overexpressing and silencing OR3A4 in gastric cancer cells. OR3A4 promoted cancer cell growth, angiogenesis, metastasis, and tumorigenesis in vitro and in vivo. Global microarray analysis combined with RT-PCR, RNA immunoprecipitation, and RNA pull-down analyses after OR3A4 transfection demonstrated that OR3A4 influenced biologic functions in gastric cancer cells via regulating the activation of PDLIM2, MACC1, NTN4, and GNB2L1. Our results reveal OR3A4 as an oncogenic lncRNA that promotes tumor progression, Therefore, lncRNAs might function as key regulatory hubs in gastric cancer progression.

Epidermal growth factor-like domain 7 promotes cell invasion and angiogenesis in pancreatic carcinoma

Epidermal growth factor-like domain 7 (EGFL7), also known as vascular endothelial stain, was firstly identified as a modulator of smooth muscle cell migration. Though the expression of EGFL7 was reported to be up-regulated during tumorigenesis, the clinical and biological functions of EGFL7 in pancreatic carcinoma (PC) were still not fully elucidated. In this study, we found that the serum EGFL7 level in PC tissues was statistically higher than that in normal subjects (p<0.001), and its level in non-resectable patients was also higher than that in resectable ones (p=0.013). Among these resectable PC patients, the postoperative EGFL7 expression was significantly down-regulated when tumors were resected (p=0.018). Using the immunohistochemistry method, our results demonstrated that the positive expression of EGFL7 was significantly associated with the TNM stage (p=0.024), lymph node metastasis (p=0.003) and local invasion (p=0.022), and the EGFL7 expression closely correlated to the micro-vessel density (MVD) in PC tissues by Spearman analysis (r=0.941, p=0.000). In vitro, EGFL7 was silenced by the small interference RNA in PC cells, and our data indicated that down-regulation of EGFL7 did not influence the cycle progression, proliferation, colony formation and apoptosis of PC cells (p>0.05), whereas inhibition of EGFL7 expression could decrease PaCa-2 cell invasion (p<0.05). More interestingly, by tubular formation, Chick embryo chorioallantoic membrane (CAM) and ELISA assays, our results revealed that silencing EGFL7 expression represented a strong inhibiting effect on tubular formation of micro-vessels through down-regulating the protein levels of VEGF and Ang-2 (p<0.05). Our results raised the possibility of using EGFL7as a potential prognostic biomarker and therapy target of PC, and down-regulation of EGFL7 might be considered to be a potentially important molecular treatment strategy for patients with PC.

Lgr5 Contributes to Intestinal Metaplasia During Gastric Carcinogenesis: A Meta analysis

Lgr5, which is a somatic stem cell biomarker, plays an important role during the carcinogenesis and tumor progression. But in gastric cancer, the functions of Lgr5 still remain controversial. Our meta-analysis is performed to evaluate the potential associations between Lgr5 and the outcome of patients with gastric cancer (GC). In our study, a total of 6 studies comprising 1092 patients were included. Our results demonstrated that high expression of Lgr5 was not associated to the depth of tumor invasion (pooled OR=1.395, CI95%=0.652-2.958, P=0.392, random-effect), gender of patients (pooled OR=1.264, 95%CI=0.933-1.713, P=0.13, fixed effect), tumor distance metastasis (pooled OR=1.1, 95%CI=0.734-3.754, P=0.772, random-effect), tumor size (pooled OR=0.977, 95%CI=0.705-1.353, P=0.887, random-effect), TNM stages (pooled OR=1.304, 95%CI=0.449-3.789, p=0.625, random-effect) and lymph node metastasis (pooled OR=1.507, 95%CI=0.829-2.738, P=0.178, random-effect). But interestingly, the expression of Lgr5 was associated with the age of GC patients (pooled OR=1.731, 95%CI=1.082-2.769, P=0.02) and Lauren type of GC (OR=2.284, 95%CI=1.611-3.238, P&lt;0.001). Our findings indicated that Lgr5 might contribute to the intestinal metaplasia during gastric carcinogenesis. This difference in pathological Lauren's classification is of practical significance for us to make about appropriate treatment options in gastric cancer.

LGR5, a relevant marker of cancer stem cells, indicates a poor prognosis in colorectal cancer patients: a meta-analysis

BACKGROUND

Leucine-rich repeat-containing G protein-coupled receptor 5 (Lgr5) has been identified as a putative intestinal stem cell marker. However, the clinical prognosis of Lgr5 is still controversial in colorectal cancer (CRC). To systematically summarize the clinical prognostic function of Lgr5 in colorectal cancer, we performed this meta-analysis.

METHODS

Published articles which assessed the clinical or prognostic role of Lgr5 was searched in Pubmed, Embase and Springer and collected until the publication month of February 2014. The association of Lgr5 expression with clinical outcomes was investigated by a meta- analysis.

RESULTS

A total of 8 studies have been up to the inclusion standard, comprised 2139 patients. Lgr5 showed no relationship with the gender of patients (OR=0.919, 95% CI=0.730-1.157, P=0.473) and the depth of invasion (OR=2.616, CI 95%=0.947-7.221, P=0.063). Lgr5 was significantly associated with lymph node metastasis (OR=2.248, 95%CI=1.205-4.192, P=0.011), tumor distance metastasis (OR=3.872, 95%CI=2.792-5.370, P<0.001) and classification of TNM (pooled OR=3.264, 95% CI=1.731-6.155, P<0.001). Overall, overexpression of Lgr5 was statistically related to the reduced overall survival (HR=6.130, 95% CI=2.845-13.210, P<0.001).

CONCLUSIONS

Lgr5 participates in the progression of CRC as a putative factor. Overexpression of Lgr5 was distinctly correlated with poor patient survival. These findings suggested that Lgr5 might serve as an efficient biomarker for prognostic indicator, and could be a new molecular target in colorectal cancer therapy.

Upregulated expression of miR-106a by DNA hypomethylation plays an oncogenic role in hepatocellular carcinoma

Aberrant microRNA (miRNA) expression has been widely recognized to play an extremely important role in several cancers, including hepatocellular carcinoma (HCC). According to the previous studies, abnormal miR-106a expression was closely related to various cancer occurrences. However, the miR-106a expression in HCC remains unclear. In our study, we firstly detected the miR-106a expression levels in 36 pairs of HCC tissues. The results showed that miR-106a expression in HCC tissues was apparently higher than the level in the adjacent tissues. Then, we used quantitative real-time PCR (qPCR) and BSP to analyze miR-106a expression and promoter methylation in HCC cell lines. There came to a conclusion that the methylation status of the miR-106a promoter region was inversely correlated with the expression of miR-106a. After prediction with online software, we further used dual-luciferase reporter gene assay to ensure that TP53INP1 and CDKN1A might be the direct targets of miR-106a. At last, we explored the functions of miR-106a in HCC cells in vitro. Our results manifested that high-miR-106a cell line had stronger invasiveness, faster cell cycle progression, and more resistance to apoptosis compared with the low-miR-106a cell line. Therefore, our study suggested that upregulated expression of miR-106a by its promoter hypomethylation might contribute to the progression of HCC, which might be considered as a potentially effective biomarker and therapeutic approach in the future.

Up-regulation of miR-592 correlates with tumor progression and poor prognosis in patients with colorectal cancer

miR-592, as a potential biomarker, has been linked to several cancers. However, the expression level and prognostic value of miR-592 in CRC have not been elucidated. In this study, we detected the miR-592 expression in CRC serum, tumor tissues, adjacent non-tumor tissues (NATs) and four colorectal cancer cell lines by RT-PCR. Our data proved that miR-592 expression was up-regulated in clinical CRC serum and tissues (P<0.05). Serum or tissue miR-592 in CRC metastatic patients also maintained a high level, compared to that in non-metastatic CRC patients (P<0.05). After radical surgery, postoperative serum miR-592 level in CRC patients significantly decreased (P<0.05). Our clinicopathological analysis revealed that high miR-592 was significant associated with the tumor size (P=0.008), TNM stage (P=0.026), distant metastasis (P=0.004) and preoperative CEA level (P=0.022), which led to a shorter overall survival rate in CRC patients (P=0.032). Furthermore, we designed and transfected miR-592 mimics or inhibitors into the corresponding CRC lines, and our experiments in vitro demonstrated that miR-592 could promote cell proliferation, wound healing and invasion ability of CRC cells (P<0.05), while miR-592 did not influence the CRC cell apoptosis (P>0.05). All these results suggested that miR-592 functioned as a novel and potential carcinogen-initiated and metastasis-related biomarker in CRC, and down-regulation of miR-592 might be considered as a potentially significant molecular treatment strategy for CRC patients.

A promising gene delivery system developed from PEGylated MoS2 nanosheets for gene therapy

A new class of two-dimensional (2D) nanomaterial, transition metal dichalcogenides (TMDCs) such as MoS2, MoSe2, WS2, and WSe2 which have fantastic physical and chemical properties, has drawn tremendous attention in different fields recently. Herein, we for the first time take advantage of the great potential of MoS2 with well-engineered surface as a novel type of 2D nanocarriers for gene delivery and therapy of cancer. In our system, positively charged MoS2-PEG-PEI is synthesized with lipoic acid-modified polyethylene glycol (LA-PEG) and branched polyethylenimine (PEI). The amino end of positively charged nanomaterials can bind to the negatively charged small interfering RNA (siRNA). After detection of physical and chemical characteristics of the nanomaterial, cell toxicity was evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Polo-like kinase 1 (PLK1) was investigated as a well-known oncogene, which was a critical regulator of cell cycle transmission at multiple levels. Through knockdown of PLK1 with siRNA carried by novel nanovector, qPCR and Western blot were used to measure the interfering efficiency; apoptosis assay was used to detect the transfection effect of PLK1. All results showed that the novel nanocarrier revealed good biocompatibility, reduced cytotoxicity, as well as high gene-carrying ability without serum interference, thus would have great potential for gene delivery and therapy.