Guanylate binding protein 5 accelerates gastric cancer progression via the JAK1-STAT1/GBP5/CXCL8 positive feedback loop.

Guanylate binding protein 5 (GBP5) is a member of the interferon (IFN)-inducible large guanosine triphosphate hydrolases (GTPase) family that regulates cell-autonomous immunity and malignant tumor transformation. However, its specific roles and underlying mechanisms GBP5 in gastric cancer (GC) remain unknown. In this study, we aimed to determine the role GBP5 and underlying mechanism of GBP5 in GC cell progression. Potential oncogenic roles of GBP5 in GC as well as its relationship with the tumor immune microenvironment (TIME) were comprehensively evaluated using bioinformatics analysis. Protein expression levels of GBP5 and their correlation with clinicopathological features of patients were assessed using immunohistochemistry. In addition, diverse in vitro functional experiments were performed to identify the functions of GBP5 in GC. Downstream targets of GBP5 were identified using RNA-sequencing analysis and verified using western blotting or quantitative polymerase chain reaction analysis in different cell lines. GBP5 expression is commonly upregulated and promotes the proliferation and migration of GC cells. Mechanistically, GBP5 was regulated by the IFNγ-Janus kinase (JAK1)-signal transducer and activator of transcription 1 (STAT1) axis and induced CXCL8 expression. Interestingly, GBP5-induced CXCL8 regulated the JAK1-STAT1 signaling pathway to form a positive feedback loop. Moreover, GBP5 is closely related to the TIME and may be used as a biomarker for predicting the efficacy of immunotherapy. Our findings revealed a new JAK1-STAT1/GBP5/CXCL8 pathway and highlighted the value of GBP5 as a predictive biomarker and novel target for GC intervention.

miR-635 targets KIFC1 to inhibit the progression of gastric cancer.

Accumulating studies have shown that the dysregulation of microRNAs is related to the carcinogenesis and development of gastric cancer (GC), and the role of miR-635 in GC remains largely unknown. miR-635 and Kinesin Family Member C1 (KIFC1) mRNA expression in GC tissues and paracancerous tissues and cells were detected by quantitative real-time PCR. KIFC1 protein expression in GC tissues and paracancerous normal tissues and cells was detected by immunohistochemistry and western blot. Cell proliferation was monitored by Cell Counting Kit-8 assay and 5-bromo-2'-deoxyuridine assay. Transwell assay was employed to detect the migration and invasion of GC cells. The dual-luciferase reporter gene assay was adopted to detect the targeting relationship between miR-635 and KIFC1. Compared with paracancerous tissues, miR-635 expression was remarkably decreased in GC tissues; conversely, KIFC1 expression was significantly increased. Compared with human normal gastric epithelial cell GSE-1, miR-635 expression was markedly decreased in GC cell lines. Meanwhile, KIFC1 expression was significantly increased, and the Kaplan-Meier Plotter database showed that its high expression was remarkably associated with poor prognosis. Additionally, miR-635 can negatively regulate KIFC1. miR-635 can target KIFC1 to inhibit proliferation, migration and invasion of GC cells. Collectively, miR-635 is lowly expressed in GC, and it inhibits proliferation, migration and invasion of GC cells via regulating KIFC1.

[Antitumour efficacy of a novel oncolytic adenovirus Ad-TD-RFP for human nasopharyngeal carcinoma].

OBJECTIVE: To evaluate the antitumor efficacy of Ad-TD-RFP for human nasopharyngeal carcinoma cells (C666-1) in vitro and in vivo. METHODS: The oncolytic effects of Ad-TD-RFP and control virus dl11520 on C666-1 cells were determined by cytotoxicity assay (MTS assay). Viral replication of Ad-TD-RFP and dl11520 was detected at different time points (24 h, 48 h, 72 h and 96 h) by tissue culture infective dose (TCID(50)) in C666-1 cells implanted subcutaneously into the flank in each of BALB/c nude mice. The xenografts were injected intratumorally with Ad-TD-RFP or dl1520 to investigate their effects on tumor growth. RESULTS: The concentration for 50% of maximal effect (EC(50)) values of Ad-TD-RFP and dl1520 were (107.6 ± 3.2) pt/cell and (174.1 ± 4.0) pt/cell, respectively (t = 22.6, P < 0.001). The Ad-TD-RFP replication was 3-14 folds more than dl1520 replication at four time points (24 h, 48 h, 72 h and 96 h) in C666-1 cells (t values were 33.6, 23.4, 20.8 and 17.3, respectively, P < 0.001). The average tumor volumes of PBS group, dl1520 group and Ad-TD-RFP group were (1765.5 ± 713.9) mm(3), (1036.9 ± 623.8) mm(3), and (420.8 ± 238.7) mm(3), respectively (F = 12.0, P < 0.05) on day 67 after treatment. CONCLUSIONS: The antitumour efficacy of the novel oncolytic adenovirus Ad-TD-RFP for human nasopharyngeal carcinoma C666-1 cells is superior to that of dl1520 in vitro and in vivo. The outcome of this study provides an experimental basis for the treatment of human nasopharyngeal carcinoma by viral gene therapy.

[Value of normalization window of tumor vasculature in neoadjuvant chemotherapy for patients with unresectable gastric cancer].

OBJECTIVE: To evaluate the value of normalization window of tumor vasculature (NWTV) in patients with unresectable gastric cancer undergoing neoadjuvant chemotherapy. METHODS: From October 2010 to March 2011, 93 patients with unresectable advanced or locally advanced gastric carcinoma were prospectively collected and randomly divided to Group A(n=30), Group B(n=29), and Group C(n=34). Group A received FOLFOX4 as conventional neoadjuvant chemotherapy. Group B received FOLFOX4 plus bevacizumab. The treatment was adjusted in Group C according to the hypothesis of NWTV with neoadjuvant chemotherapy delivered 5 days after bevacizumab treatment. The efficacy, drug toxicity and clinical outcome were assessed and compared between the three groups. RESULTS: There were no significant differences among the 3 groups in demographics(P>0.05). All the patients completed the neoadjuvant chemotherapy. Efficacy and toxicity between the three groups were comparable(P>0.05). The rates of tumor downstaging in the three groups were 56.7%(17/30), 72.4%(21/29), 85.3%(29/34), respectively, with a significantly lower downstaging rate in Group C as compared to Group A(P<0.05). R0 resection rates were 23.3%(7/30), 27.6%(8/29), 52.9% (18/34), respectively, with significantly higher R0 resection rate in Group C as compared to Group A and Group B(All P<0.05). There was no perioperative death in this cohort. Postoperative complications were comparable among the 3 groups(P>0.05). CONCLUSIONS: Anti-angiogenesis agent can improve the efficacy of neoadjuvant chemotherapy in unresectable gastric cancer. Furthermore, administration according to NWTV may achieve better outcomes.