Lizong Shen

Aquaporin 3 promotes epithelial-mesenchymal transition in gastric cancer

BackgroundGastric carcinoma (GC) is a common and lethal malignancy, and epithelial-mesenchymal transition (EMT) is believed to contribute to invasive and metastatic tumor growth. Aquaporin 3 (AQP3) is overexpressed in human GC tissues, while human epidermal growth factor (EGF) and hepatocyte growth factor, which can induce EMT, are able to up-regulate AQP3 expression, subsequently promoting GC cell migration and proliferation. The purpose of this study was to investigate the effects of AQP3 on EMT in human GC.MethodsAQP3 and EMT-related proteins were detected by immunohistochemistry in human GC specimens and their clinical significance evaluated. AQP3 knockdown was attempted using small interfering RNAs, while EGF was used to up-regulate AQP3 expression. Western blotting, real-time quantitative polymerase chain reaction assays and immunofluorescence were used to evaluate changes in expression of AQP3 and EMT-related proteins in the SGC7901 and MGC803 human GC cell lines.ResultsAQP3 up-expression was associated with EMT-related proteins in human GC specimens, which correlated with poor prognosis for GC. AQP3 modulated GC cell proliferation, migration and invasion in vitro, and induced E-cadherin repression. AQP3 also up-regulated the expression of vimentin and fibronectin in vitro. The PI3K/AKT/SNAIL signaling pathway was likely involved in the induction of EMT by AQP3 in GC.ConclusionsAQP3 promotes EMT in human cases of GC, allowing us to understand the mechanisms of AQP3 in GC progression, thus providing a potential strategy for its treatment.

Aquaporin-3 positively regulates matrix metalloproteinases via PI3K/AKT signal pathway in human gastric carcinoma SGC7901 cells

Backgroundmatrix metalloproteinases (MMPs) are produced by tumor cells, so they may be associated with tumor progression including invasion, migration, angiogenesis and metastasis. Aquaporin-3 (AQP3) also plays a critical role in gastric cancer cell migration and proliferation.MethodsIn this study, AQP3 was silenced or over-expressed in SGC7901 cells.ResultsWe found a significant decrease in MT1-MMP, MMP-2, and MMP-9 expression after AQP3 knockdown, and a significant increase in MT1-MMP, MMP-2, and MMP-9 expression after AQP3 over-expression in SGC7901 cells. We also found that AQP3 silence led to a significant decrease of phosphorylation of ser473 in AKT in SGC7901 cells.ConclusionOur findings showed that AQP3 might positively regulate MMPs proteins expression through PI3K/AKT signal pathway in human gastric carcinoma SGC7901 cells.

Aquaporin 3 promotes the stem-like properties of gastric cancer cells via Wnt/GSK-3β/β-catenin pathway

Cancer stem cells (CSCs) are believed to contribute to the tumor growth in gastric carcinoma (GC), a common lethal malignancy. This study investigated the effect of aquaporin 3 (AQP3) on stem-like properties of human GC cells. Elevated AQP3 expression was associated with CD44 expression in human GC specimens. Expression of AQP3 and that of CD44 positively correlated with Lauren classification, lymph node metastasis, and lymphovascular invasion. Altering the AQP3 expression had pronounced effects on the tumorigenic potential and self-renewal capacity of the gastric cancer cell lines SGC7901, MGC803, and AGS, both in vitro and in vivo. Overexpression of AQP3 induced CD44 expression and activation of the β-catenin signaling pathway, whereas silencing AQP3 expression using short hairpin RNA had the opposite effect. Furthermore, pharmacological inhibition of GSK-3β using LiCl impaired the effect of AQP3 knockdown in CSCs, whereas the inhibition of the Wnt/β-catenin pathway by XAV939 blocked the effect of AQP3 overexpression. These results demonstrate that AQP3 promotes stem-like properties of human GC cells by activating the Wnt/GSK-3β/β-catenin signaling pathway.

Aquaporin 3 facilitates chemoresistance in gastric cancer cells to cisplatin via autophagy

Cisplatin (cDDP) remains one of the first-line chemotherapeutic agents for gastric cancer (GC) treatment, and resistance to cDDP is the major limitation in its clinical application. Mechanisms of cDDP resistance have been shown to be varied and complicated. Aquaporin 3 (AQP3) has been demonstrated to be overexpressed in GC tissues and is thought to be involved in GC carcinogenesis and progression. However, the role of AQP3 in chemosensitivity of GC to cytotoxic agents remains unknown. In this study, we show that AQP3 overexpression induced resistance to cDDP in AGS cells (P<0.05), and AQP3 knockdown increased the chemosensitivity in MGC803 and SGC7901 cells (P<0.05). Moreover, cDDP treatment enhanced AQP3 expression in MGC803, SGC7901 and AGS cells. AQP3 overexpression promoted the conversion of LC3-I to LC3-II in AGS cells, whereas AQP3 knockdown inhibited this conversion in MGC803 and SGC7901 cells. AQP3 upregulation increased Atg5 and Beclin-1 expression, and inhibited P62 expression in AGS cells, whereas AQP3 knockdown showed the opposite results in MGC803 and SGC7901 cells. Chloroquine (CQ), an autophagy inhibitor, enhanced the cytotoxicity of cDDP in GC cells, and CQ reversed the chemoresistance to cDDP caused by AQP3 overexpression in GC cells. Together, our data demonstrate that AQP3 facilitates cisplatin resistance in gastric cancer cells via autophagy, and suggest that the development of AQP3-based tumor therapeutics could play a key role in future GC treatment strategies.

Preoperative serum CEA and CA19-9 in gastric cancer--a single tertiary hospital study of 1,075 cases.

To evaluate the clinical impact of preoperative serum CEA and CA19-9 on resectable gastric cancer (GC), a total of 1,075 consecutive cases with gastric adenocarcinoma were obtained retrospectively from January 2012 and December 2013 in a single tertiary hospital, and the relationships between serum CEA, CA19-9 and clinicopathologic features were investigated. Positive preoperative serum rates of CEA and CA19-9 were 22.4% and 12.3% respectively, levels significantly correlating with each other and depth of invasion, lymph node involvement, pTNM and stage. The CEA level also presented a remarkable association with lymphovascular invasion. Both CEA and CA19-9 positivity significantly and positively correlated with depth of invasion, nodal involvement, pTNM stage, lymphovascular invasion, tumor size and tumor location. Stratified analyses according to gender or tumor location showed preoperative CEA or CA19-9 had different associations with clinicopathologic features in different gender subgroups or location subgroups. Preoperative serum CA19-9 positivity may be more meaningful for tumor size rather than CEA. In conclusion, preoperative serum CEA and CA19-9 correlate with disease progression of GC, and may have applications in aiding more accurate estimation of tumor stage, decision of treatment choice and prognosis evaluation.

Potential role of aquaporin 3 in gastric intestinal metaplasia

Gastric intestinal metaplasia (GIM) is a pre-cancerous condition and a pivotal step in the formation of gastric cancer (GC). Aquaporin 3 (AQP3) has been found to be expressed in goblet cells rather than mucus-secreting glands. To investigate the characteristics of GIM in non-cancerous tissues adjacent to GC, as well as the expression and role of AQP3 in GIM tissues, 16 patients diagnosed with gastric adenocarcinoma of intestinal type located in the lesser curve of the antrum were consecutively enrolled in this study. A new pathological technology called “gastric mucosal sausage roll” was introduced. GIM was determined according to the updated Sydney system, and AQP3 expression in goblet cells was determined by immunohistochemistry. GIM was found in all stomach specimens, and its incidence increased with progression to GC (P < 0.001). GIM prevalence displayed remarkable association with the distance to GC in the anterior gastric wall tissues (P = 0.016) and tissues toward the cardia (P = 0.014), such that GIM was more common in the areas closer to GC (P < 0.001). AQP3 was found to be expressed in 67.71% of parts with GIM, and AQP3 immunoreactivity was identified more frequently in severe GIM areas (P < 0.001). In short, the incidence and severity of GIM correlated with the distance from GC, and AQP3 was differentially expressed in goblet cells, with most AQP3-positive goblet cells presenting in severe GIM. Together, this study suggests that AQP3 may play an important role in gastric carcinogenesis from GIM.

Helicobacter pylori infection promotes Aquaporin 3 expression via the ROS–HIF-1α–AQP3–ROS loop in stomach mucosa: a potential novel mechanism for cancer pathogenesis

Helicobacter pylori (H. pylori) is the major stomach carcinogen, but the molecular mechanism responsible for the pathogenesis of cancer development mediated by H. pylori infection is still unclear. Aquaporin 3 (AQP3), overexpressed in gastric carcinoma, has a crucial role in gastric carcinogenesis and progression. However, the triggers and precise regulations for AQP3 upregulation during gastric carcinogens also remain unknown. Here we report that H. pylori infection-mediated carcinogenesis may be mechanistically depended on the upregulation of AQP3 expression via reactive oxygen species (ROS) pathway activation in the stomach. The retrospective analyses of clinical samples from patients with gastric carcinoma and other different stages of gastric diseases indicated that AQP3 expression was positively associated with gastric mucosal disease progression and H. pylori infection status as well. Furthermore, H. pylori infection significantly upregulated AQP3 and HIF-1α expression and increased ROS amount in human gastric epithelial AGS and GES-1 cells. Blockage of ROS with inhibitors, NAC and DPI, markedly decreased the expression of AQP3 and HIF-1α in both AGS and GES-1 cells simultaneously. Furthermore, the increased AQP3 in cells was mechanistically due to the transcriptional regulation by HIF-1α. In addition, H. pylori infection exerted production of proinflammatory cytokines IL-6, IL-8, and TNF depending on AQP3 level. Importantly, these in vitro novel findings were further investigated in vivo in a mouse H. pylori infectious model. Our current studies identify the mechanistic link between H. pylori infection and AQP3 upregulation in the pathogenesis of gastric carcinoma, which involves the activation of the ROS–HIF-1α axis and the exacerbated ROS–HIF-1α–AQP3–ROS loop.

Application of enhanced recovery after gastric cancer surgery: An updated meta-analysis

AIM To provide an updated assessment of the safety and efficacy of enhanced recovery after surgery (ERAS) protocols in elective gastric cancer (GC) surgery. METHODS PubMed, Medline, EMBASE, World Health Organization International Trial Register, and Cochrane Library were searched up to June 2017 for all available randomized controlled trials (RCTs) comparing ERAS protocols and standard care (SC) in GC surgery. Thirteen RCTs, with a total of 1092 participants, were analyzed in this study, of whom 545 underwent ERAS protocols and 547 received SC treatment. RESULTS No significant difference was observed between ERAS and control groups regarding total complications (P = 0.88), mortality (P = 0.50) and reoperation (P = 0.49). The incidence of pulmonary infection was significantly reduced (P = 0.03) following gastrectomy. However, the readmission rate after GC surgery nearly tripled under ERAS (P = 0.009). ERAS protocols significantly decreased the length of postoperative hospital stay (P < 0.00001) and medical costs (P < 0.00001), and accelerated bowel function recovery, as measured by earlier time to the first flatus (P = 0.0004) and the first defecation (P < 0.0001). Moreover, ERAS protocols were associated with a lower level of serum inflammatory response, higher serum albumin, and superior short-term quality of life (QOL). CONCLUSION Collectively, ERAS results in accelerated convalescence, reduction of surgical stress and medical costs, improved nutritional status, and better QOL for GC patients. However, high-quality multicenter RCTs with large samples and long-term follow-up are needed to more precisely evaluate ERAS in radical gastrectomy.

Involvement of Aryl Hydrocarbon Receptor and Aryl Hydrocarbon Receptor Repressor in Helicobacter Pylori-related Gastric Pathogenesis

Background: Persistent Helicobacter pylori (H. pylori) infection leads to various gastric diseases. Multiple studies have demonstrated that aryl hydrocarbon receptor (AHR) plays roles in the antibacterial response and aryl hydrocarbon receptor repressor (AHRR) is downregulated in stomach cancer. However, the role of AHR or AHRR in H. pylori-related gastric diseases remains unclear. Aims: To investigate whether AHR or AHRR is involved in H. pylori-related gastric diseases. Methods: Patients with gastritis or gastric adenocarcinoma were enrolled randomly, and gastric tissue specimens were diagnosed pathologically. AHR, AHRR, and H. pylori infection status in tissues were detected by immunohistochemistry. Human gastric cells were cocultured with H. pylori. siRNAs were used to silence AHR or AHRR, and a C57bl/6 mouse model colonized by H. pylori was established. Protein expression was determined by western blotting analysis, and TNF, IL-8 and IL-1β in cell supernatants were measured by ELISA. Results: AHR and AHRR were expressed in gastritis tissues and gastric cancer tissues without H. pylori infection, and principally located in the cytoplasm and nucleus. AHR expression was significantly correlated with AHRR expression in gastric tissues without H. pylori infection (P=0.008). However, their expressions were negatively correlated with H. pylori infection status. H. pylori coculture inhibited AHR and AHRR expression in stomach mucosa in vitro and in vivo. Gastric cells produced more TNF, IL-8 and IL-1β when AHR or AHRR was silenced. Conclusions: This preliminary study indicates that AHR and AHRR may be involved in H. pylori-related gastric pathogenesis, and helps toward understanding of inflammation-initiated carcinogenesis of gastric cancer.

Identification of AQP3 and CD24 as biomarkers for carcinogenesis of gastric intestinal metaplasia

Gastric intestinal metaplasia (GIM) is a precancerous gastric carcinoma (GC) lesion with pivotal roles in carcinogenesis. CD24, LGR5 and Ki67 are expressed in GIM; we previously demonstrated that aquaporin 3 (AQP3) is expressed in goblet cells and is positively correlated with GIM severity. However, the relationships of AQP3 with GIM classification and with other proteins, and their roles in the transition from GIM to gastric carcinoma (GC) remain unknown. Sixteen patients with intestinal-type GC were enrolled in this study. GIM was determined according to the updated Sydney system; GIM classification was determined via HID-AB staining, and AQP3, CD24, LGR5 and Ki67 expression were determined by immunohistochemistry. Type III GIM was more prevalent around the GC and displayed a positive association with GIM severity. CD24 was found in GIM, but LGR5 and Ki67 were found in tissues regardless of GIM. AQP3 expression showed significant correlation to type III GIM. CD24 expression was correlated with the marked GIM and incomplete GIM, while LGR5 expression decreased with GIM aggravation and did not have relationship with classification of GIM. However, Ki67 presented no association with GIM grade or classification. These observations identify AQP3 and CD24 as biomarkers for carcinogenesis of GIM, and may provide a precise strategy for screening at-risk candidates with GIM.Gastric intestinal metaplasia (GIM) is a precancerous gastric carcinoma (GC) lesion with pivotal roles in carcinogenesis. CD24, LGR5 and Ki67 are expressed in GIM; we previously demonstrated that aquaporin 3 (AQP3) is expressed in goblet cells and is positively correlated with GIM severity. However, the relationships of AQP3 with GIM classification and with other proteins, and their roles in the transition from GIM to gastric carcinoma (GC) remain unknown. Sixteen patients with intestinal-type GC were enrolled in this study. GIM was determined according to the updated Sydney system; GIM classification was determined via HID-AB staining, and AQP3, CD24, LGR5 and Ki67 expression were determined by immunohistochemistry. Type III GIM was more prevalent around the GC and displayed a positive association with GIM severity. CD24 was found in GIM, but LGR5 and Ki67 were found in tissues regardless of GIM. AQP3 expression showed significant correlation to type III GIM. CD24 expression was correlated with the marked GIM and incomplete GIM, while LGR5 expression decreased with GIM aggravation and did not have relationship with classification of GIM. However, Ki67 presented no association with GIM grade or classification. These observations identify AQP3 and CD24 as biomarkers for carcinogenesis of GIM, and may provide a precise strategy for screening at-risk candidates with GIM.