Hongyong He

Objective Our previous studies have identified CXCL8 as the crucial chemokine responsible for gastric cancer metastasis mediated by loss of RACK1. However, the regulatory effect of CXCL8 on immune surveillance in gastric cancer remains obscure. Design Flow cytometry analyses were performed to examine major source of CXCL8 and phenotypes of immune cells in fresh tumour tissues from 76 patients with gastric cancer. Real-time PCR was performed to analyse CXCL8 mRNA level in gastric cancer tissues. For immunohistochemical analyses, a total of 420 patients with gastric cancer undergoing curative resection were enrolled. In vitro culture of fresh tumour tissue was performed to evaluate the potential therapeutic effect of blocking CXCL8 pathway in gastric cancer. Results Increased level of CXCL8 indicates poor clinical outcome and tumour progression in patients with gastric cancer. In gastric cancer tissues, CXCL8 is predominantly secreted by macrophages and colony stimulating factor 2 (CSF-2) facilitates macrophage-derived CXCL8 secretion. High level of CXCL8 is associated with decreased CD8 + T cells infiltration and Ki67 + CD8 + T cells proportion. Moreover, CXCL8 also inhibits CD8 + T cells function by inducing the expression of PD-L1 on macrophages. Finally, we show that a small-molecule CXCR2 inhibitor, reparixin, drives the decreased programmed death-ligand 1 (PD-L1 + ) macrophages and promotes antitumour immunity. Accordingly, high levels of CXCL8 + macrophages are positively correlated with poor prognosis in patients with gastric cancer. Conclusions CXCL8 is predominantly secreted by macrophages and contributes to the immunosuppressive microenvironment by inducing PD-L1 + macrophages in gastric cancer. CXCL8 inhibitors may drive antitumour response, providing potential therapeutic effects for patients with gastric cancer.

Importance: The safety of laparoscopic total gastrectomy (LTG) for the treatment of gastric cancer remains uncertain given the lack of high-level clinical evidence. Objective: To compare the safety of LTG for clinical stage I gastric cancer with that of conventional open total gastrectomy (OTG). Design, Setting, and Participants: The Chinese Laparoscopic Gastrointestinal Surgery Study (CLASS) Group CLASS02 study was a prospective, multicenter, open-label, noninferiority, randomized clinical trial that compared the safety of LTG vs OTG with lymphadenectomy for patients with clinical stage I gastric cancer. From January 2017 to September 2018, a total of 227 patients were enrolled. Final follow-up was in October 2018. Interventions: Eligible patients were randomized to LTG (n = 113) or OTG (n = 114) by an interactive web response system. Main Outcomes and Measures: The primary outcome was the morbidity and mortality within 30 days following surgeries between LTG and OTG with a noninferiority margin of 10%. The secondary outcomes were recovery courses and postoperative hospital stays. Results: A total of 214 patients were analyzed for morbidity and mortality (105 patients in the LTG group and 109 patients in the OTG group). The mean (SD) age was 59.8 (9.4) years in the LTG group and 59.4 (9.2) years in the OTG group, and most were male (LTG group, 75 of 105 [71.4%]; OTG group, 80 of 109 [73.4%]). The overall morbidity and mortality rates were not significantly different between the groups (rate difference, -1.1%; 95% CI, -11.8% to 9.6%). Intraoperative complications occurred in 3 patients (2.9%) in the LTG group and 4 patients (3.7%) in the OTG group (rate difference, -0.8%; 95% CI, -6.5% to 4.9%). In addition, there was no significant difference in the overall postoperative complication rate of 18.1% in the LTG group and 17.4% in the OTG group (rate difference, 0.7%; 95% CI, -9.6% to 11.0%). One patient in the LTG group died from intra-abdominal bleeding secondary to splenic artery hemorrhage. However, there was no significant difference in mortality between the LTG group and the OTG group (rate difference, 1.0%; 95% CI, -2.5% to 5.2%), and the distribution of complication severity was similar between the 2 groups. Conclusions and Relevance: The results of the CLASS02 trial showed that the safety of LTG with lymphadenectomy by experienced surgeons for clinical stage I gastric cancer was comparable to that of OTG. Trial Registration: ClinicalTrials.gov Identifier: NCT03007550.

OBJECTIVE: To investigate the clinical significance of IL-10+ tumor-associated macrophages (TAMs) in gastric cancer. BACKGROUND: Due to the plasticity and diversity of TAMs, it is necessary to phenotypically and functionally classify subsets of TAMs to better understand the critical role of TAMs in cancer progression. TAMs expressing interleukin-10 (IL-10) have been found to facilitate immune evasion in many malignancies, but the role of IL-10+ TAMs in gastric cancer remains obscure. METHODS: Four hundred and sixty-eight tumor tissue microarray specimens, 52 fresh tumor tissue samples of gastric cancer patients from Zhongshan Hospital, and data of 298 gastric cancer patients from the Cancer Genome Atlas (TCGA) were analyzed. IL-10+ TAM level and immune contexture were examined by CIBERSORT, immunohistochemistry, and flow cytometry. Clinical outcomes were analyzed by Kaplan-Meier curves and Cox model. RESULTS: Gastric cancer patients with high IL-10+ TAM infiltration exhibited poor prognosis and inferior therapeutic responsiveness to fluorouracil-based adjuvant chemotherapy. IL-10+ TAM infiltration yielded an immunoevasive tumor microenvironment featured by regulatory T cell infiltration and CD8+ T cell dysfunction. The combinational analysis of IL-10+ TAM and CD8+ T cell infiltration stratified patients into distinct risk groups with different clinical outcomes. Moreover, IL-10+ TAM infiltration was correlated with tumor-intrinsic characteristics including EBV status, PD-L1 expression, and genome stability in gastric cancer. CONCLUSIONS: This study revealed that IL-10+ TAMs might drive an immunoevasive microenvironment and determine poor prognosis and inferior therapeutic responsiveness to fluorouracil-based adjuvant chemotherapy, indicating IL-10+ TAMs could be applied as a potential target for immunotherapeutic approach in gastric cancer.

Digestion and detoxification are the two most important functions of the liver, and liver cells always keep a high metabolism level and active vesicular traffic. The malfunction of the vesicular traffic system might be a cause of the abnormal biological behavior of cancerous liver cells. The Ras superfamily is known to regulate various steps of vesicular traffic in eukaryotic cells. It would be significant to determine the change of vesicular transport molecules such as the members of Ras superfamily in carcinogenesis of liver cells. In the present study, we have cloned nine novel genes encoding human small GTPases: RAB1B, RAB4B, RAB10, RAB22A, RAB24, RAB25 ARL5, SARA1, and SARA2, among which the former six belong to the RAB family and the latter three belong to the ARF/SAR1 family. The identification of these new genes has greatly enlarged the pool of the Ras superfamily. It is interesting to find that they are upregulated in most of the 11 hepatocellular carcinoma and 1 cholangiohepatoma cases. Furthermore, the expression in 16 normal human adult tissues, the chromosome loci, and the gene structures of the nine genes are also described. The above findings could be valuable for understanding the vesicular transport system and elucidating the molecular basis of liver cancer carcinogenesis.