DC - SIGNR by influencing the lncRNA HNRNPKP2 upregulates the expression of CXCR4 in gastric cancer liver metastasis

A bibliometric analysis of gastric cancer liver metastases: advances in mechanisms of occurrence and treatment options

BACKGROUND

Gastric cancer (GC) is the fifth most commonly diagnosed cancer worldwide, and its poor prognosis is predominantly attributed to distant metastasis. Liver is the primary site of GC metastasis. However, there is no universally approved treatment regimen for liver metastasis in GC. The aim of this article is to review the current research status and trends of liver metastasis of gastric cancer worldwide.

METHODS

We utilized the Web of Science Core Collection database to identify articles on liver metastasis from GC published between 2000 and 2022. We used bibliometric methods to analyze authors, institutions, countries, journals, and references through CiteSpace and VOSviewer. A total of 1,003 articles were included in this study.

RESULTS

Japan published the most articles in the field, followed by China. Nagoya University is the leading institution in the field of liver metastases in GC. Yasuhiro Kodera from Japan has made significant achievements in this area. We identified Gastric Cancer to be the most influential journal in this field. Using cluster analysis, the keywords were divided into four major clusters:(1) the molecular mechanism of gastric cancer liver metastasis (2) prognosis (3) liver resection (4) chemotherapy.

CONCLUSION

Our study systematically summarizes the results of gastric cancer liver metastasis research from 2000 to 2022 and describes and predicts research hotspots and trends on a global scale. Research on the molecular mechanisms of gastric cancer liver metastasis will become a hot topic in the future, and the expansion of the surgical treatment scope and the advancement of translational therapy will benefit more patients.

The regulatory role of cancer stem cell marker gene CXCR4 in the growth and metastasis of gastric cancer

Single-cell RNA sequencing (scRNA-seq) and bulk RNA sequencing (bulk RNA-seq) are increasingly used for screening genes involved in carcinogenesis due to their capacity for dissecting cellular heterogeneity. This study aims to reveal the molecular mechanism of the cancer stem cells (CSCs) marker gene CXCR4 in gastric cancer (GC) growth and metastasis through scRNA-seq combined with bulk RNA-seq. GC-related scRNA-seq data were downloaded from the GEO database, followed by UMAP cluster analysis. Non-malignant cells were excluded by the K-means algorithm. Bulk RNA-seq data and clinical sample information were downloaded from the UCSC Xena database. GO and KEGG pathway analyses validated the correlation between genes and pathways. In vitro and in vivo functional assays were used to examine the effect of perturbed CXCR4 on malignant phenotypes, tumorigenesis, and liver metastasis. A large number of highly variable genes were identified in GC tissue samples. The top 20 principal components were selected, and the cells were clustered into 6 cell types. The C4 cell cluster from malignant epithelial cells might be CSCs. CXCR4 was singled out as a marker gene of CSCs. GC patients with high CXCR4 expression had poor survival. Knockdown of CXCR4 inhibited the malignant phenotypes of CSCs in vitro and curtailed tumorigenesis and liver metastasis in nude mice. CSC marker gene CXCR4 may be a key gene facilitating malignant phenotypes of CSCs, which thus promotes tumor growth and liver metastasis of GC.

Chebulagic acid suppresses gastric cancer by inhibiting the AURKA/β-catenin/Wnt pathway

Gastric cancer (GC) is a prevalent malignant neoplasm that poses a serious threat to human health. Overexpression of Aurora A (AURKA) is frequently associated with the self-renewal and tumorigenicity of various cancers. Chebulagic acid (CA) has been examined as a potential tumor suppressor based on its ability against numerous tumor biological activities. However, the possible mechanisms of CA inhibition of the progression of GC by mediating the AURKA/β-catenin/Wnt signaling pathway have not been investigated. The present study investigated the level of AURKA expression in GC. We further examined the effect of CA on cell proliferation, migration, and apoptosis in the MKN1 and NUGC3 GC cell lines, and its efficacy in suppressing tumor growth was assessed in tumor bearing mice model. We demonstrated that AURKA was highly expressed in GC and associated with poor prognosis. We demonstrated that treatment with CA significantly inhibited the proliferation and migration of GC cells and induced apoptosis. Compared to the vehicle group, CA treatment severely diminished the volume and weight and the metastasis of tumors. CA also inhibited the expression of AURKA and the AURKA/β-catenin/Wnt signaling pathway in vitro and in vivo. Collectively, the present results demonstrated that high expression of AURKA may be an independent factor of poor prognosis in patients with GC, and CA significantly suppressed the tumor biological functions of GC and inhibited the AURKA/β-catenin/Wnt pathway.

The XPA Protein-Life under Precise Control

Nucleotide excision repair (NER) is a central DNA repair pathway responsible for removing a wide variety of DNA-distorting lesions from the genome. The highly choreographed cascade of core NER reactions requires more than 30 polypeptides. The xeroderma pigmentosum group A (XPA) protein plays an essential role in the NER process. XPA interacts with almost all NER participants and organizes the correct NER repair complex. In the absence of XPA's scaffolding function, no repair process occurs. In this review, we briefly summarize our current knowledge about the XPA protein structure and analyze the formation of contact with its protein partners during NER complex assembling. We focus on different ways of regulation of the XPA protein's activity and expression and pay special attention to the network of post-translational modifications. We also discuss the data that is not in line with the currently accepted hypothesis about the functioning of the XPA protein.

Molecular mechanism and potential therapeutic targets of liver metastasis from gastric cancer

Gastric cancer (GC) is characterized by high invasion and poor prognosis. The occurrence of liver metastasis seriously affects advanced GC prognosis. In recent years, great progress has been made in the field of GC liver metastasis. The abnormal expression of related genes leads to the occurrence of GC liver metastasis through metastasis cascades. The changes in the liver microenvironment provide a pre-metastasis condition for GC cells to colonize and grow. The development of several potential therapeutic targets might provide new therapeutic strategies for its treatment. Therefore, we reviewed the regulatory mechanism of abnormal genes mediating liver metastasis, the effect of liver resident cells on liver metastasis, and potential therapeutic targets, hoping to provide a novel therapeutic option to improve the quality of life and prognosis of GC patients with liver metastasis.

Demystifying the CXCR4 conundrum in cancer biology: Beyond the surface signaling paradigm

The oncogenic chemokine duo CXCR4-CXCL12/SDF-1 (C-X-C Receptor 4-C-X-C Ligand 12/ Stromal-derived factor 1) has been the topic of intense scientific disquisitions since Muller et al., in her ground-breaking research, described this axis as a critical determinant of organ-specific metastasis in breast cancer. Elevated CXCR4 levels correlate with distant metastases, poor prognosis, and unfavourable outcomes in most solid tumors. Therapeutic impediment of the axis in clinics with Food and Drug Administration (FDA) approved inhibitors like AMD3100 or Plerixafor yield dubious results, contrary to pre-clinical developments. Clinical trials entailing inhibition of CXCR7 (C-X-C Receptor 7), another convicted chemokine receptor that exhibits affinity for CXCL12, reveal outcomes analogous to that of CXCR4-CXCL12 axis blockade. Of note, the cellular CXCR4 knockout phenotype varies largely from that of inhibitor treatments. These shaky findings pique great curiosity to delve further into the realm of this infamous chemokine receptor to provide a probable explanation. A multitude of recent reports suggests the presence of an increased intracellular CXCR4 pool in various cancers, both cytoplasmic and nuclear. This intracellular CXCR4 protein reserve seems active as it correlates with vital tumor attributes, viz. prognosis, aggressiveness, metastasis, and disease-free survival. Diminishing this entire intracellular CXCR4 load apart from the surface signals looks encouraging from a therapeutic point of view. Transcending beyond the classically accepted concept of ligand-mediated surface signaling, this review sheds new light on plausible associations of intracellularly compartmentalised CXCR4 with various aspects of tumorigenesis. Besides, this review also puts forward a comprehensive account of CXCR4 regulation in different cancers.

Novel roles of LSECtin in gastric cancer cell adhesion, migration, invasion, and lymphatic metastasis

Liver and lymph node sinusoidal endothelial cell C-type lectin (LSECtin) plays an important regulatory role in a variety of diseases, including tumors. However, the underlying mechanism of LSECtin in gastric cancer (GC) remains largely unknown. In our research, LSECtin promoted the adhesion and invasion of GC cells, and was involved in lymphatic metastasis of GC cells. Mechanistically, LSECtin promoted the adhesion, proliferation and migration of GC cells by downregulating STAT1 expression. The circular RNA circFBXL4, which is regulated by LSECtin, sponges the microRNA miR-146a-5p to regulate STAT1 expression. The promotion of GC cell proliferation, migration and invasion mediated by LSECtin was largely inhibited by circFBXL4 overexpression or miR-146a-5p silencing. Moreover, in its role as a transcription factor, STAT1 modulated the expression of FN1 and CHD4. In conclusion, LSECtin might be involved in the lymphatic metastasis of GC by upregulating the expression of FN1 and CHD4 via the circFBXL4/miR-146a-5p/STAT1 axis, possibly indicating a newly discovered pathogenic mechanism.

Huaier Inhibits Gastric Cancer Growth and Hepatic Metastasis by Reducing Syntenin Expression and STAT3 Phosphorylation

Gastric cancer (GC) is a common malignant tumor worldwide and poses a serious threat to human health. As a traditional Chinese medicine, Huaier (Trametes robiniophila Murr.) has been used in the clinical treatment of GC. However, the mechanism underlying the anticancer effect of Huaier remains poorly understood. In this study, we used in vivo imaging technology to determine the anticancer effect of the Huaier n-butanol extract (HBE) on orthotopic and hepatic metastasis of GC mouse models. We found that HBE suppressed tumor growth and metastasis without causing apparent host toxicity. Proteomic analysis of GC cells before and after HBE intervention revealed syntenin to be one of the most significantly downregulated proteins after HBE intervention. We further demonstrated that HBE suppressed the growth and metastasis of GC by reducing the expression of syntenin and the phosphorylation of STAT3 at Y705 and reversing the epithelial-mesenchymal transition (EMT). In addition, we confirmed that syntenin was highly expressed in GC tissue and correlated with metastasis and poor prognosis. In conclusion, our results suggest that Huaier, a clinically used anticancer drug, may inhibit the growth and liver metastasis of GC by inhibiting the syntenin/STAT3 signaling pathway and reversing EMT.

Epigenetic Regulation of CXCR4 Signaling in Cancer Pathogenesis and Progression

Signaling involving chemokine receptor CXCR4 and its ligand SDF-1/CXL12 has been investigated for many years for its possible role in cancer progression and pathogenesis. Evidence emerging from clinical studies in recent years has further established diagnostic as well as prognostic importance of CXCR4 signaling. CXCR4 and SDF-1 are routinely reported to be elevated in tumors, distant metastases, which correlates with poor survival of patients. These findings have kindled interest in the mechanisms that regulate CXCR4/SDF-1 expression. Of note, there is a particular interest in the epigenetic regulation of CXCR4 signaling that may be responsible for upregulated CXCR4 in primary as well as metastatic cancers. This review first lists the clinical evidence supporting CXCR4 signaling as putative cancer diagnostic and/or prognostic biomarker, followed by a discussion on reported epigenetic mechanisms that affect CXCR4 expression. These mechanisms include regulation by non-coding RNAs, such as, microRNAs, long non-coding RNAs and circular RNAs. Additionally, we also discuss the regulation of CXCR4 expression through methylation and acetylation. Better understanding and appreciation of epigenetic regulation of CXCR4 signaling can invariably lead to identification of novel therapeutic targets as well as therapies to regulate this oncogenic signaling.

LINC00853 restrains T cell acute lymphoblastic leukemia invasion and infiltration by regulating CCR9/CCL25

BACKGROUND

Leukemia is a group of hematopoietic malignancies characterized by the accumulation and infiltration of abnormal hematopoietic stem cells or early progenitor cells. T cell acute lymphoblastic leukemia (T-ALL) is a hematologic malignancy occurring in 15 % of pediatric and 25 % of adult ALL cases. Infiltration and metastasis of leukemic cells to specific organs are consequences of disease relapse and dismal prognosis. Long non-coding RNAs (lncRNAs) have been identified to function in the migration, invasion and infiltration of tumors by regulating gene expression. Our previous studies showed that CC chemokine receptor 9 (CCR9), which specifically bind to CC chemokine ligand 25 (CCL25), promotes T-ALL infiltration.

METHODS

Bioinformatic methods were used to screen LINC00853 in gene expression omnibus (GEO) datasets. RT-qPCR, western bolt and flow cytometry were applied to detect the expression of LINC00853 and CCR9. Transwell and martrigel-transwell were employed to assess the cells migration and invasion abilities. Fluorescence microscope was applied to observed the green fluorescence protein positive (GFP⁺) cells. Lentivirus and adenovirus were packed to construct nc-blank, sh-LINC00853-blank and sh-LINC00853-rescue jurkat cell lines.

RESULTS

In this study, we found out the negative correlation of LINC00853 and CCR9 expression. LINC00853 was downregulated while CCR9 was upregulated in GEO datasets, T-ALL cell lines and clinical samples. Moreover, LINC00853 suppressed jurkat cells migration and invasion in vitro and restrained infiltration in liver, spleen, kidney, lung, brain, ovary of nonobese diabetic/severe combined immunodeficient (NOD/SCID) mice.

CONCLUSIONS

These findings indicate that LINC00853 restrains T-ALL cell invasion and infiltration by regulating CCR9/CCL25.

A five-lncRNA model predicting overall survival in gastric cancer compared with normal tissues

Aims: In cancer research, normal tissues adjacent to the tumor are usually defined as controls to compare with tumor samples, in order to screen out cancer-related genes. Although there is no obvious difference in pathology between normal tissues adjacent to the tumor and healthy tissues, there are significant changes at the molecular level. We aim to explore more potential tumor biomarkers using healthy tissues as controls rather than normal tissues adjacent to the tumor.

Methods: Here we combine the Genotype-Tissue Expression project and The Cancer Genome Atlas for differential gene analysis. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes analyses were applied in order to predict the biological effects of related lncRNAs.

Results: We established a 5-lncRNA prognosis model with an AUC value of 0.815. Pathway analysis indicated that 5-lncRNA mainly affected tissue carcinogenesis through PI3K-AKT signaling pathway, Focal adhesion, MAPK signaling pathway.

Conclusion: The 5-lncRNA prognostic model we set up is more conducive to assess the overall survival time of gastric cancer patients.

LINC00668 cooperated with HuR dependent upregulation of PKN2 to facilitate gastric cancer metastasis

In China, gastric cancer (GC) ranks first in the incidence of all malignant tumors. With high recurrence and distant metastasis, GC has caused considerable mortalities. LncRNA long intergenic non-protein-coding RNA 668 (LINC00668) has been reported to be upregulated in GC cells and predict poor prognosis of GC patients. However, the mechanism of LINC00668 has not been fully investigated in GC. This study aimed to investigate the role of LINC00668 in GC. We found that LINC00668 level was upregulated in GC tissue and cells and predicted poor prognosis. Functionally, LINC00668 knockdown suppressed GC cell migration and invasion. Additionally, LINC00668 knockdown inhibited epithelial to mesenchymal transition (EMT) process. PKN2 exerts similar effects with LINC00668 in GC cells. LINC00668 knockdown suppressed tumor growth and metastasis in vivo. Mechanistically, HuR was predicted to bind with LINC00668 and protein kinase N2 (PKN2). RNA pull-down assays validated the binding between HuR and LINC00668 (or PKN2). Moreover, either silencing of LINC00668 or HuR could decrease PKN2 mRNA stability or reduce PKN2 mRNA and protein levels. Furthermore, PKN2 expression was positively correlated with LINC00668 expression and HuR expression in GC tissues, and HuR expression was positively associated with LINC00668 expression in GC tissues. Finally, rescue assays confirmed that the suppressive effect of LINC00668 silencing on cell migration, invasion, and EMT process was reversed by PKN2 overexpression or HuR upregulation. In conclusion, LINC00668 cooperated with HuR-dependent upregulation of PKN2 to facilitate gastric cancer metastasis, which may provide a potential novel insight for GC treatment.

Dual relationship between long non-coding RNAs and STAT3 signaling in different cancers: New insight to proliferation and metastasis

Uncontrolled growth and metastasis of cancer cells is an increasing challenge for overcoming cancer, and improving survival of patients. Complicated signaling networks account for proliferation and invasion of cancer cells that need to be elucidated for providing effective cancer therapy, and minimizing their malignancy. Long non-coding RNAs (lncRNAs) are RNA molecules with a length of more than 200 nucleotides. They participate in cellular events, and their dysregulation in a common phenomenon in different cancers. Noteworthy, lncRNAs can regulate different molecular pathways, and signal transducer and activator of transcription 3 (STAT3) is one of them. STAT3 is a tumor-promoting factors in cancers due to its role in cancer proliferation (cell cycle progression and apoptosis inhibition) and metastasis (EMT induction). LncRNAs can function as upstream mediators of STAT3 pathway, reducing/enhancing its expression. This dual relationship is of importance in affecting proliferation and metastasis of cancer cells. The response of cancer cells to therapy such as chemotherapy and radiotherapy is regulated by lncRNA/STAT3 axis. Tumor-promoting lncRNAs including NEAT1, SNHG3 and H19 induces STAT3 expression, while tumor-suppressing lncRNAs such as MEG3, PTCSC3 and NKILA down-regulate STAT3 expression. Noteworthy, upstream mediators of STAT3 such as microRNAs can be regulated by lncRNAs. These complicated signaling networks are mechanistically described in the current review.

CLEC4M overexpression inhibits progression and is associated with a favorable prognosis in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) remains the most common malignant cancer worldwide. Numerous studies have indicated that C-type lectin domain family 4 member M (CLEC4M) is associated with tumor progression; however, the biological functions of CLEC4M in HCC have not been investigated. In the present study, CLEC4M overexpression was observed to be associated with a favorable patient overall, relapse-free, progression-free and disease-specific survival by using the KMplot™ database. The present study then concentrated specifically on the functions of CLEC4M by performing cell counting kit-8 proliferation, 5-Ethynyl-2′-deoxyuridine and flow cytometric assays. CLEC4M overexpression inhibited proliferation and enhanced apoptosis in Huh7 and PLC/PRF/5 cells. Furthermore, the results demonstrated by using western blotting that CLEC4M overexpression inhibited the Janus kinase 1/signal transducer and activator of transcription 3 pathway, which is involved in various types of tumors including HCC. In conclusion, the present study reported that CLEC4M may be considered as a novel indicator of HCC and may provide a theoretical basis for improving the survival of patients with HCC.

LncRNA DRAIC inhibits proliferation and metastasis of gastric cancer cells through interfering with NFRKB deubiquitination mediated by UCHL5

Background

Long non-coding RNA (lncRNA) as a widespread and pivotal epigenetic molecule participates in the occurrence and progression of malignant tumors. DRAIC, a kind of lncRNA whose coding gene location is on 15q23 chromatin, has been found to be weakly expressed in a variety of malignant tumors and acts as a suppressor, but its characteristics and role in gastric cancer (GC) remain to be elucidated.

Methods

Sixty-seven primary GC tissues and paired paracancerous normal tissues were collected. Bioinformatics is used to predict the interaction molecules of DRAIC. DRAIC and NFRKB were overexpressed or interfered exogenously in GC cells by lentivirus or transient transfection. Quantitative real-time PCR (qPCR) and western blotting were used to evaluate the expression of DRAIC, UCHL5 and NFRKB. The combinations of DRAIC and NFRKB or UCHL5 and NFRKB were verified by RNA-IP and Co-IP assays. Ubiquitination-IP and the treatment of MG132 and CHX were used to detect the ubiquitylation level of NFRKB. The CCK-8 and transwell invasion and migration assays measured the proliferation, migration and invasion of GC cells.

Results

DRAIC is down-regulated in GC tissues and cell lines while its potential interacting molecules UCHL5 and NFRKB are up-regulated, and DRAIC is positively correlated with NFRKB protein instead of mRNA. Lower DRAIC and higher UCHL5 and NFRKB indicated advanced progression of GC patients. DRAIC could increase NFRKB protein significantly instead of NFRKB mRNA and UCHL5, and bind to UCHL5. DRAIC combined with UCHL5 and attenuated binding of UCHL5 and NFRKB, meanwhile promoting the degradation of NFRKB via ubiquitination, and then inhibited the proliferation and metastasis of GC cells, which can be rescued by oeNFRKB.

Conclusion

DRAIC suppresses GC proliferation and metastasis via interfering with the combination of UCHL5 and NFRKB and mediating ubiquitination degradation.

Ultrasound-guided secondary radiofrequency ablation combined with chemotherapy in gastric cancer with recurrent liver metastasis

Background

The incidence and mortality of gastric cancer are in the second and third place of malignant tumor in China, respectively. Liver metastasis is an important cause of death of these patients. This study is to explore whether the secondary radiofrequency ablation (RFA) treatment can prolong the survival period and improve the life quality of patients with gastric cancer and recurrent liver metastases.

Methods

A total of 87 patients with gastric cancer and recurrent liver metastases were retrospective analyzed, 46 cases were assigned into study group and 41 cases in control group. The efficacy of the two groups was observed, and the prognostic factors were analyzed.

Results

The median survival time in the study group was significantly longer than that in the control group (P<0.05). The survival rate of the study group was significantly higher than that of the control group (both P<0.05). The life quality scores of the study group were significantly higher than the control group (both P<0.05).

Conclusions

Ultrasound-mediated secondary RFA combined with chemotherapy is superior to chemotherapy alone in the treatment of gastric cancer with recurrent liver metastases.

XPA: DNA Repair Protein of Significant Clinical Importance

The nucleotide excision repair (NER) pathway is activated in response to a broad spectrum of DNA lesions, including bulky lesions induced by platinum-based chemotherapeutic agents. Expression levels of NER factors and resistance to chemotherapy has been examined with some suggestion that NER plays a role in tumour resistance; however, there is a great degree of variability in these studies. Nevertheless, recent clinical studies have suggested Xeroderma Pigmentosum group A (XPA) protein, a key regulator of the NER pathway that is essential for the repair of DNA damage induced by platinum-based chemotherapeutics, as a potential prognostic and predictive biomarker for response to treatment. XPA functions in damage verification step in NER, as well as a molecular scaffold to assemble other NER core factors around the DNA damage site, mediated by protein–protein interactions. In this review, we focus on the interacting partners and mechanisms of regulation of the XPA protein. We summarize clinical oncology data related to this DNA repair factor, particularly its relationship with treatment outcome, and examine the potential of XPA as a target for small molecule inhibitors.

LncRNA LOC285194 modulates gastric carcinoma progression through activating Wnt/β-catenin signaling pathway

Emerging evidences have revealed long noncoding RNAs (lncRNAs’) critical roles in diverse human carcinoma. Among these cancers, lncRNA LOC285194 has been extensively investigated in several types of carcinomas in the recent years. Nevertheless, the biological function, clinical relevance, and the influence of LOC285194 in gastric cancer (GC) are not fully understood. The present study aims to explore the biological function of LOC285194 in the progression and development of GC. First, LOC285194 expressions were detected in GC tissues and cell lines. The functional role of LOC285194 in GC was evaluated both in vitro and in vivo. Our data found that LOC285194 was lowly expressed both in human GC tissues and GC cell lines compared with corresponding normal controls. Moreover, LOC285194 was mitigated by transfection with LV‐LOC285194 in both HGC‐27 and MKN45 cell lines. Silencing of LOC285194 remarkably induced GC cell livability and cell proliferation. On the contrary, the LOC285194 overexpression suppressed MKN45 and HGC‐27 cell proliferation and promoted cell apoptosis. Additionally, silencing of LOC285194 increased the ability of colony formation, cell migration, and invasive capacities, together with blocking the apoptotic rates of GC cells. Correspondently, LOC285194 overexpression exerted the opposite effects. Mechanistically, silencing of LOC285194 promoted GC progression via inducing Wnt signaling activity. Moreover, in vivo xenografts nude mice model results showed that LOC285194 inhibited GC progression through targeting Wnt signaling. Taken together, LOC285194 is associated with GC progression by regulating the Wnt signaling transduction, potentiating LOC285194's promising role as a novel treatment biomarker in GC.

High expression levels of CLEC4M indicate poor prognosis in patients with hepatocellular carcinoma

The identification of novel and accurate biomarkers is important to improve the prognosis of patients with hepatocellular carcinoma (HCC). C-Type lectin domain family 4 member M (CLEC4M) is involved in the progression of numerous cancer types. However, the clinical significance of CLEC4M in HCC is yet to be elucidated. The aim of the present study is to evaluate the involvement of CLEC4M in HCC progression. The expression level of CLEC4M was determined in tumor, and their corresponding adjacent non-tumor tissues derived from 88 patients with HCC, using immunohistochemistry, western blot and reverse transcription-quantitative PCR. The correlation between CLEC4M expression and certain clinicopathological characteristics was retrospectively analyzed. The results suggested that CLEC4M was specifically labeled in sinusoidal endothelial cells, in both HCC and non-tumor tissues. Moreover, the expression of CLEC4M in tumor tissues was significantly lower than that in non-tumor tissues (P<0.0001), which indicated its potential as a biomarker of the development of HCC. Subsequently, correlation analysis suggested that the relatively higher CLEC4M expression in HCC tissues was significantly associated with increased microvascular invasion (P=0.008), larger tumor size (P=0.018), absence of tumor encapsulation (P<0.0001) and lower tumor differentiation (P=0.019). Notably, patients with high CLEC4M expression levels in their tumor tissues experienced more frequent recurrence and shorter overall survival (OS) times compared with the low-expression group. Furthermore, CLEC4M expression in tumor tissues was identified as an independent and significant risk factor for recurrence-free survival and OS. The results of the present study suggest that CLEC4M may be a valuable biomarker for the prognosis of the patients with HCC, postoperatively.

The Effects of Electroacupuncture in a Rat Model of Cerebral Ischemia-Reperfusion Injury Following Middle Cerebral Artery Occlusion Involves MicroRNA-223 and the PTEN Signaling Pathway

Background

In China, electroacupuncture (EA) is used to treat the symptoms of ischemic stroke. However, the mechanisms involved in the effects of EA in cerebral ischemia remain to be investigated. This study aimed to investigate the molecular mechanism underlying the effects of EA in a rat model of cerebral ischemia-reperfusion injury (CIRI) induced by middle cerebral artery occlusion (MCAO).

Material/Methods

Seventy-five male Sprague-Dawley rats were divided into five groups: the sham group (with sham surgery), the model group (the MCAO model), the EA group (treated with EA), the EA control group, and the EA+antagomir-223-3p group. Rats in the model of CIRI underwent MCAO for 90 minutes. EA was performed on the second postoperative day and was performed at the Waiguan (TE5) and Zusanli (ST36) acupoints. The rat brains were evaluated for structural and molecular markers.

Results

EA treatment significantly upregulated the expression of microRNA-223 (miR-223), NESTIN, and NOTCH1, and downregulated the expression of PTEN in the subventricular zone (SVZ) and hippocampus. The luciferase reporter assay supported that PTEN was a direct target of miR-223, and antagomiR-223-3p reversed the effects of EA and reduced the increase in NESTIN and inhibition of PTEN expression associated with EA treatment. There was a negative correlation between PTEN expression and the number of neural stem cells (NSCs).

Conclusions

In a rat model of CIRI following MCAO, EA activated the NOTCH pathway, promoted the expression of miR-223, increased the number of NSCs, and reduced the expression of PTEN.

DC-SIGN mediates gastric cancer progression by regulating the JAK2/STAT3 signaling pathway and affecting LncRNA RP11-181G12.2 expression

BACKGROUND

The molecular mechanisms of gastric cancer (GC) development are very complicated. Recent studies revealed that DC-specific intercellular adhesion molecule 3-grabbing nonintegrin (DC-SIGN)-related protein (DC-SIGNR) is involved in colon cancer and GC biological processes. However, the exact roles of DC-SIGN in GC remain unrevealed.

METHODS

DC-SIGN overexpression and knockdown experiments were performed by using DC-SIGN shRNA or DC-SIGN plasmid to investigate the biological roles of DC-SIGN in proliferation, cell cycle progression, migration and invasion of GC cells in vitro. Furthermore, the lncRNA profiles of SGC-7901 cells with control shRNA and DC-SIGN shRNA were generated by using microarray analysis. Mechanistically, the relationship between DC-SIGN, RP11-181G12.2 and the JAK2/STAT3 signaling pathway was then investigated using qRT-PCR and western blot assays. Additionally, we analyzed DC-SIGN and RP11-181G12.2 expression levels in GC specimens based on the Cancer Genome Atlas database.

RESULTS

In this study, the results showed that DC-SIGN was highly expressed in GC cells and significantly correlated with advanced clinical stage and lymphatic metastasis. Downregulation of DC-SIGN significantly inhibited the proliferation, cell cycle progression, migration and invasion of GC cells in vitro. The reverse results could partly be seen with the upregulation of DC-SIGN. Mechanistically, knockdown of DC-SIGN inactivated the JAK2/STAT3 signaling pathway, and overexpression of DC-SIGN activated the JAK2/STAT3 signaling pathway. In addition, through LncPath microarray analysis, we identified a lncRNA, RP11-181G12.2, that was significantly upregulated after knockdown of DC-SIGN; this was also confirmed by qRT-PCR. Furthermore, RP11-181G12.2 knockdown enhanced DC-SIGN expression in GC cells, further activating the JAK2/STAT3 signaling pathway. In contrast, DC-SIGN overexpression suppressed RP11-181G12.2 expression.

CONCLUSIONS

Our study suggests that DC-SIGN might be involved in the progression of GC by regulating the JAK2/STAT3 signaling pathway and affecting lncRNA RP11-181G12.2 expression.

Decreased DC-SIGNR expression in hepatocellular carcinoma predicts poor patient prognosis

Dendritic cell-specific intercellular adhesion molecule-grabbing non-integrin-related protein (DC-SIGNR) is a transmembrane receptor primarily involved in pathogen recognition by the innate immune system, with particular importance for viral recognition. DC-SIGNR may also be associated with tumorigenesis. The aim of the present study was to investigate the association between DC-SIGNR expression, development of hepatocellular carcinoma (HCC), and clinicopathological features. Immunohistochemistry was used to assess DC-SIGNR protein expression in HCC and paired non-cancerous tissue samples. DC-SIGNR expression was lower in HCC tissues compared with adjacent non-tumor tissue samples. The expression of DC-SIGNR was associated with small tumor size, low Edmondson grade and high patient long term survival rates. Bioinformatics analyses were performed on several datasets to assess the potential function of DC-SIGNR and related genes; the data revealed that DC-SIGNR mRNA expression was lower in HCC tissues compared with non-cancerous controls, and analyses of ten-year survival rates indicated patients with low DC-SIGNR expression exhibited shorter average survival times. In conclusion, decreased DC-SIGNR expression in HCC tissues may be a relevant predictive biomarker of clinical prognosis, in addition to being a viable therapeutic target for HCC treatment.

Lysyl oxidase promotes liver metastasis of gastric cancer via facilitating the reciprocal interactions between tumor cells and cancer associated fibroblasts

Background

Liver is one of the most preferred destinations of distant metastasis in gastric cancer (GC). As effective treatment is still limited, the prognosis of GC patients bearing liver metastasis is poor. We filter out lysyl oxidase (LOX) to study its function in the tumor microenvironment (TME) and seek for potential therapeutic targets.

Methods

Transcription analysis on 6 cases of liver metastasis of GC patients with respective paired primary tumors and adjacent normal livers was performed. The filtration out of LOX was done using 5 datasets. 69 GC liver metastasis tissues were utilized to perform immunohistochemistry (IHC) and analyze prognosis. Computed Tomography (CT) combined 3D organ reconstruction bioluminescence imaging was performed to precisely evaluate the metastatic tumor burden on liver of intrasplenic injection mouse model. Human and mouse cancer associated fibroblasts (CAFs) in liver metastasis were separated to culture to study the interaction of LOX and TGF-β1. Patients-derived xenograft (PDX) model was established using liver metastasis of patients to evaluate the therapeutic value of LOX inhibitor β‐aminopropionitrile (BAPN).

Results

CAFs-derived LOX at liver metastatic niche of GC promotes niche formation and outgrowth thus predicts poor prognosis. Meanwhile tumor cells in niche secrete TGF-β1 to nourish CAFs and stimulate them to produce more LOX in turn. The mechanism involved in LOX-mediated proliferation facilitation is enhancement of Warburg effect. The inhibitor of LOX, BPAN could hamper the effect brought by LOX in vivo and in vitro.

Interpretation

Our study has unveiled a positive feedback loop between CAFs and tumor cells in liver metastasis niche of GC. The core molecule is LOX which facilitates Warburg effect. Targeting LOX with its inhibitor BAPN might serve as a potential therapeutic strategy.

Fund

This research was supported by the National Natural Science Foundation of China (31872740), the 100-member plan of the Shanghai Municipal Commission of Health and Family Planning (2017BR043), Shanghai Science and Technology Commission Project(17ZR1416800), Renji Hospital Training Fund (PYMDT-003, PYIII-17–015), National Natural Science Foundation of China (81672358), the Shanghai Municipal Education Commission—Gao feng Clinical MedicineGrant Support (20181708), Program of Shanghai Academic/Technology Research Leader(19XD1403400), Science and Technology Commission of Shanghai Municipality (18410721000), Shanghai Municipal Health Bureau (2018BR32), China Postdoctoral Science Foundation (2018M640403), National Natural Science Foundation of China (81701945) and Youth project of Shanghai Municipal Health Commission(20164Y0045).

CLEC4M is associated with poor prognosis and promotes cisplatin resistance in NSCLC patients

Cisplatin-based chemotherapy is the foundation of treatment for major non-small cell lung cancer (NSCLC) patients. However, cisplatin resistance is still a challenging issue, and the molecular mechanisms underlying this resistance remain to be fully explored. CLEC4M, a Ca²⁺-dependent C-type lectin, has recently been found to correlate with tumourigenesis. This study mainly focused on whether CLEC4M impacts clinical prognosis and how CLEC4M contributes to cisplatin resistance in NSCLC. Our results found that CLEC4M was correlated with poor prognosis in patients with lung cancer. In addition, a positive association between CLEC4M expression and the IC50 values of cisplatin was found, which suggests that CLEC4M may impact cisplatin sensitivity. In vitro results from cultured A549 and H1299 cells confirmed that CLEC4M could enhance cisplatin resistance, while CLEC4M knockdown led to higher sensitivity to cisplatin in these cells. Further experiments showed that the underlying mechanisms included inhibition of cisplatin-induced cell apoptosis by CLEC4M and improved DNA repair capacity by upregulating XPA and ERCC1 expression. In addition, CLEC4M was able to promote cell migration with or without cisplatin treatment. Collectively, these findings suggest the potential clinical significance of CLEC4M inhibition in overcoming cisplatin resistance in NSCLC patients.

Non-coding RNAs in regulating gastric cancer metastasis

Gastric cancer is one of the leading causes of cancer-related deaths worldwide, and mortality remains high, especially in East Asia. At present, the main method to diagnose gastric cancer is pathological biopsy. At the time of diagnosis, most patients have been diagnosed with advanced cancer and metastasis. The treatment of gastric cancer patients is mainly radical surgical resection and chemoradiotherapy, while patients with metastatic tumor have great challenges to radical surgery and are prone to drug resistance. Metastasis is an important factor affecting tumor development. In addition, evidence accumulated in the literature indicates that non-coding RNA plays a key role in tumor metastasis. This article reviews the role of ncRNAs in gastric cancer metastasis and discusses the regulatory mechanism in the development and treatment of gastric cancer.

DC-SIGN-LEF1/TCF1-miR-185 feedback loop promotes colorectal cancer invasion and metastasis

DC-SIGN is previously focused on its physiologic and pathophysiologic roles in immune cells. Little is known about whether DC-SIGN is expressed in malignant epithelial cells and how DC-SIGN participates in tumor progression. Here we showed that DC-SIGN expression was increased in metastatic colorectal cancer (CRC) cell lines and patient tissues. The overall survival in CRC patients with positive DC-SIGN was remarkably reduced. Gain of DC-SIGN function facilitated the CRC metastases both in vitro and in vivo, and this effect was reversed by miR-185. DC-SIGN and Lyn interacted physically, and Lyn maintained the stability of DC-SIGN in cells. DC-SIGN activation recruited Lyn and p85 to form the DC-SIGN-Lyn-p85 complex, which promoted CRC metastasis by increasing PI3K/Akt/β-catenin signaling in tyrosine kinase Lyn-dependent manner. Furthermore, activation of DC-SIGN promoted the transcription of MMP-9 and VEGF by increasing PI3K/Akt/β-catenin signaling, and induced TCF1/LEF1-mediated suppression of miR-185. Our findings reveal the presence of the DC-SIGN–TCF1/LEF1–miR-185 loop in cancer cells with metastatic traits, implying that it may represent a new pathogenic mechanism of CRC metastasis. This character of the loop promises to provide new targets for blocking CRC invasive and metastatic activity.

LncRNAs with miRNAs in regulation of gastric, liver, and colorectal cancers: updates in recent years

Long noncoding RNA (lncRNA) is a kind of RNAi molecule composed of hundreds to thousands of nucleotides. There are several major types of functional lncRNAs which participate in some important cellular pathways. LncRNA-RNA interaction controls mRNA translation and degradation or serves as a microRNA (miRNA) sponge for silencing. LncRNA-protein interaction regulates protein activity in transcriptional activation and silencing. LncRNA guide, decoy, and scaffold regulate transcription regulators of enhancer or repressor region of the coding genes for alteration of expression. LncRNA plays a role in cellular responses including the following activities: regulation of chromatin structural modification and gene expression for epigenetic and cell function control, promotion of hematopoiesis and maturation of immunity, cell programming in stem cell and somatic cell development, modulation of pathogen infection, switching glycolysis and lipid metabolism, and initiation of autoimmune diseases. LncRNA, together with miRNA, are considered the critical elements in cancer development. It has been demonstrated that tumorigenesis could be driven by homeostatic imbalance of lncRNA/miRNA/cancer regulatory factors resulting in biochemical and physiological alterations inside the cells. Cancer-driven lncRNAs with other cellular RNAs, epigenetic modulators, or protein effectors may change gene expression level and affect the viability, immortality, and motility of the cells that facilitate cancer cell cycle rearrangement, angiogenesis, proliferation, and metastasis. Molecular medicine will be the future trend for development. LncRNA/miRNA could be one of the potential candidates in this category. Continuous studies in lncRNA functional discrepancy between cancer cells and normal cells and regional and rational genetic differences of lncRNA profiles are critical for clinical research which is beneficial for clinical practice.

MDM2 promotes epithelial-mesenchymal transition through activation of Smad2/3 signaling pathway in lung adenocarcinoma

Background

Mouse double minute 2 (MDM2) contributes to cancer metastasis and epithelial-mesenchymal transition (EMT). This study aimed to investigate small mothers against decapentaplegic (Smad) signaling in MDM2-mediated EMT in lung adenocarcinoma (LAC).

Materials and methods

Expression patterns of MDM2 in LAC tissues, adjacent tissues, and cell lines (BEAS-2B, PC9, H1975, and A549) were detected. We then overexpressed MDM2 in PC9 cells and knocked it down in H1975 cells. To explore whether MDM2 activates EMT through the Smad2/3 signaling pathway, Smad2 and Smad3 were also silenced by siRNA in H1975 cells. Male BALB/c nude mice were used in in vivo model to validate the effects of MDM2 on LAC cells.

Results

MDM2 was significantly upregulated in LAC tissues compared with adjacent tissues. The expression of MDM2 was relatively higher in PC9 cells and relatively lower in H1975 cells compared with A549 cells. Overexpression of MDM2 significantly increased cell proliferation, migration, and invasion in LAC cells, while inhibiting apoptosis in PC9 cells. On the contrary, silencing of MDM2 significantly inhibited the expression of EMT-related genes N-cadherin and vimentin, while promoting the expression of E-cadherin and β-catenin. In vivo, MDM2 knockdown inhibited tumor growth. In addition, the expression of Smad2/3 was correlated with MDM2 in H1975 cells transfected with Smad2 and Smad3 siRNAs, which inhibited EMT progress.

Conclusion

MDM2 can activate the Smad2/3 signaling pathway, which promotes the proliferation and EMT progress of LAC cells.

Activated Wnt signaling promotes growth and progression of AFP-producing gastric cancer in preclinical models

Background

Characterized by elevated AFP levels in serum, AFP-producing gastric cancer (APGC) is a very special type of gastric cancer (GC) that is difficult to treat and has poor prognosis. However, little is known about the role of AFP in GC, which was investigated in this study with in vitro and in vivo experiments.

Methods

APGC cells were established with lentivirus infection and validated by PCR assay and ELISA in HCG27 and AGS cells. Cell growth, migration, and invasion were determined by CCK8, transwell assays, and animal experiments. RNA sequencing, Western blot, dual-luciferase-reporter assays, and RNA interference were employed to understand mechanisms underlying AFP activity, followed by therapeutic investigations for APGC.

Results

APGC cells featured significantly increased AFP levels in cellular supernatants. AFP potentiated growth and aggression in GC cell lines and their derived xenografts. Wnt-signaling activation was responsible for AFP function, indicated by decreased Axin 1 and pGSK3β, followed by cascade activation of β-catenin, downstream transcription factors TCF1/TCF7, and the target gene – c-Myc. Wnt-signaling blockade by Axin 1 rescue or pathway inhibitor XAV939 reversed AFP function, suggesting the potential therapeutic value of APGC.

Conclusion

AFP played a critical role in APGC through activating Wnt signaling, and targeting Wnt pathways might be a promising strategy against APGC.

Long non-coding antisense RNA GAS6-AS1 supports gastric cancer progression via increasing GAS6 expression

OBJECTIVE

As one broader class of non-coding RNAs (lncRNAs), non-coding antisense (AS) transcripts are functionally characterized to play pivotal roles in various pathophysiological processes, including tumor biology.

METHODS

In this study, the exact biological functions and regulation mechanisms of GAS6-AS1 in gastric cancer (GC) was examined.

RESULTS

The expression of GAS6-AS1 was markedly upregulated in GC tissues and is associated with advanced stage (III + IV) of GC patients. Gain-of-function and loss-of-function experiments showed that GAS6-AS1 promoted cell proliferation, migration, invasion ability in vitro and xenograft tumor growth in vivo by promoting entry into S-phase. The mechanistic investigations showed that GAS6-AS1 can control the expression of its cognate sense gene GAS6 at the transcriptional or translational levels by forming a RNA-RNA duplex, consequently inducing an increase of AXL level and driveling AXL signaling pathway activation.

CONCLUSIONS

Taken together, our studies indicate that GAS6-AS1 significantly driving the aggressive phenotype in GC through activating its cognate sense gene GAS6, and provides a more complete understanding of GAS6-AS1 as a potential therapeutic target for GC.

LncRNA LOC728196/miR-513c axis facilitates glioma carcinogenesis by targeting TCF7

Numerous long noncoding RNAs (lncRNAs) are reported to be dysregulated in glioma. However, how lncRNA participates in the process of glioma development and progression still remains elusive. Here, we identified a novel lncRNA LOC728196 highly expressed in glioma tissues. LOC728196 high expression predicts low survival rate in patients. Our data proved that LOC728196 knockdown repressed cellular growth, migration and invasion in vitro. Silencing LOC728196 led to impaired growth of glioma in vivo. Mechanistic studies further demonstrated that LOC728196 acts as the sponge for miR-513c to upregulate TCF7 expression. We observed a reciprocal inhibition between LOC728196 and miR-513c. Rescue assay showed that either inhibition of miR-513c or TCF7 overexpression restored the abilities of proliferation, migration and invasion in LOC728196-silenced glioma cells. Taken together, our study provides a comprehensive investigation on the role of LOC728196 in glioma progression and contributes to understanding the vital role of competing endogenous RNA (ceRNA).

Long non‑coding RNA HOTTIP promotes hepatocellular carcinoma tumorigenesis and development: A comprehensive investigation based on bioinformatics, qRT‑PCR and meta‑analysis of 393 cases

HOTTIP functions as an independent biomarker in multiple cancers. However, the role of HOTTIP in hepatocellular carcinoma (HCC) remains unclear. In this study, we sought to investigate the HOTTIP expression in HCC and normal liver. We combined quantitative reverse transcription-polymerase chain reactions (qRT-PCR), Gene Expression Omnibus (GEO) and The Cancer Genome Atlas (TCGA), Multi Experiment Matrix (MEM) and Oncomine database to assess the clinical role and the potential molecular mechanism of HOTTIP in HCC. Furthermore, a meta-analysis was performed to evaluate the relationship between HOTTIP and HCC tumorigenesis and development. Additionally, bioinformatics analysis, which contained Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG) and network analysis, were applied to investigate the underlying functions, pathways and networks of the potential genes. HOTTIP was obviously upregulated in HCC. A statistically significant higher expression of HOTTIP was found in TNM (III +IV), age (≥60), sex (male), race (white) and cirrhosis (no) compared to the control groups (P<0.05). Furthermore, the meta-analysis of 393 cases from multiple centers indicated that HOTTIP had high diagnostic value in HCC. Additionally, according to GO and KEGG analyses, we found that the most strongly enriched functional terms were gland development, transcription factor activity and extrinsic to membrane. Also, the HOTTIP co-expressed genes were significantly related to PPAR signaling pathway. We speculate that HOTTIP might play a vital part in HCC via regulating various pathways, especially PPAR signaling pathway. However, the detailed mechanism should be confirmed by functional experiments.