Xing-Yu Liu

TRIM24 is upregulated in human gastric cancer and promotes gastric cancer cell growth and chemoresistance

The tripartite motif protein tripartite motif-containing 24 (TRIM24) is involved in human cancer progression. However, the expression pattern and biological roles of TRIM24 in human gastric cancer have not been studied. Here, we report that expression of TRIM24 protein was upregulated in 65 of 133 gastric cancer specimens. TRIM24 upregulation positively correlated with clinical stage, local invasion, and poor patient prognosis. We overexpressed TRIM24 by transfection in SGC-7901 cells and used an siRNA strategy to knock down TRIM24 in MKN-1 cells. MTT and colony formation assays showed that transfection of TRIM24 plasmid accelerated, while its depletion inhibited cell proliferation rate. TRIM24 overxpression also induced chemoresistance to 5-FU in gastric cancer cells. Further analysis showed that TRIM24 overexpression upregulated cyclin D1 and Akt phosphorylation. Akt inhibitor LY294002 reversed the role of TRIM24 on chemoresistance. In conclusion, our study shows that TRIM24 is overexpressed in human gastric cancer and accelerates cell growth as well as induce chemoresistance, possibly through the Akt pathway.

Milky spot macrophages remodeled by gastric cancer cells promote peritoneal mesothelial cell injury

Peritoneal dissemination (PD) is the most frequent metastatic pattern of advanced gastric cancer (GC) and the main cause of death in GC patients. Human peritoneal mesothelial cell (HPMC) injury induced by gastric cancer cells (GCCs) and GCC outgrowths supported by peritoneal milky spot macrophages (PMSMs) are the key events during gastric cancer peritoneal dissemination (GCPD). In this study, we investigated whether PMSMs remodeled by GCC can induce HPMC injury and create a favorable microenvironment for GCPD. We established a tumor-associated macrophage (TAM) model using in vitro cell coculture. Normal macrophages cocultured with GCCs down-regulated expression of antigen-presenting surface molecules CD80, CD86, and MHC-II, but, notably, they up-regulated expression of phagocytic scavenger receptor CD206, which is similar to the M2 macrophage phenotype. In further experiments, various experimental methods were applied to detect the injurious effect of TAMs on HPMCs in another TAM-HPMC coculture. Our results showed that GCCs can induce HPMC apoptosis by unregulated apoptosis associated with cleaved caspase3, cleaved caspase9, and p21 proteins. HPMC growth ceased, and both early- and late-stage apoptosis were observed. Additionally, GCCs can induce HPMC fibrosis via increased expression of epithelial cell marker E-cadherin and decreased expression of mesenchymal cell marker α-SMA. Our results demonstrate that, in the GCPD process, PMSMs were remodeled by GCCs, resulting in phenotypic and functional transformation. In turn, this transformation induced HPMC injury and provided a favorable microenvironment for GCC anchorage and growth. These results may provide new insight into the mechanisms of GCPD.

Transforming growth factor-beta1 signaling blockade attenuates gastric cancer cell-induced peritoneal mesothelial cell fibrosis and alleviates peritoneal dissemination both in vitro and in vivo

Peritoneal dissemination is the most frequent metastatic pattern of advanced gastric cancer and the main cause of death in gastric cancer patients. Transforming growth factor-beta1 (TGF- ß1), one of the most potent fibrotic stimuli for human peritoneal mesothelial cells, has been shown to play an important role in this process. In this study, we investigated the effect of TGF- ß1 signaling blockade in gastric cancer cell (GCC)-induced human peritoneal mesothelial cell (HPMC) fibrosis. HPMCs were cocultured with the high TGF- ß1 expressing GCC line SGC-7901 and various TGF- ß1 signaling inhibitors or SGC-7901 transfected with TGF-ß1-specific siRNA. HPMC fibrosis was monitored on the basis of morphology. Expression of the epithelial cell marker, E-cadherin, and the mesenchymal marker, α-smooth muscle actin (α-SMA), was evaluated by Western blotting and immunofluorescence confocal imaging. GCC adhesion to HPMC was also assayed. In nude mouse tumor model, the peritoneal fibrotic status was monitored by immunofluorescent confocal imaging and Masson’s trichrome staining; formation of metastatic nodular and ascites fluid was also evaluated. Our study demonstrated that GCC expressing high levels of TGF-ß1 induced HMPC fibrosis, which is characterized by both upregulation of E-cadherin and downregulation of α-SMA. Furthermore, HPMC monolayers fibrosis was reversed by TGF- ß1 signaling blockade. In vivo, the TGF- ß1 receptor inhibitor SB-431542 partially attenuated early-stage gastric cancer peritoneal dissemination (GCPD). In conclusion, our study confirms the significance of TGFß1 signaling blockade in attenuating GCPD and may provide a therapeutic target for clinical therapy.

Efficacy and safety of intraperitoneal chemotherapy in patients with advanced gastric cancer: a cumulative meta-analysis of randomized controlled trials

Even when a curative gastrectomy is conducted, the majority of advanced gastric cancer patients with invasion die due to peritoneal recurrence. We performed electronic searches to identify randomized controlled trials published through April 2017 evaluating the effect of intraperitoneal chemotherapy (IPC) on survival rates. We included 23 trials reporting data on 2,767 patients with advanced gastric cancer. Overall, we noted that patients who received IPC had a significantly increased 1-year survival rate, and the treatment effect of IPC on 1-year survival was most prominent in studies conducted in Japan or those with a mean age of less than 60 years. IPC was also associated with an increased incidence of 2-year survival rate, but it was not seen to have this effect in studies conducted in China or Australia or with a mean age greater than 60 years. Similarly, IPC associated with a significantly increased 3-year survival rate, but this difference was not detected in studies conducted in Austria or with a mean age greater than 60 years. IPC has no significant effect on the 5-year survival rate. Finally, IPC was associated with a lower risk of recurrence in patients with advanced gastric cancer. The findings of this study suggest that gastric cancer patients who receive IPC associate with increased 1-year, 2-year, and 3-year survival rates, but this does not extend out to a 5-year survival rate. IPC is also shown to play a protective role against the risk of recurrence in patients with advanced gastric cancer.

Effect of neoadjuvant chemotherapy in patients with gastric cancer: a PRISMA-compliant systematic review and meta-analysis

BackgroundNeoadjuvant chemotherapy (NAC) is extensively used in the treatment of patients with gastric cancer (GC), particularly in high risk, advanced gastric cancer. Previous trials testing the efficacy of NAC have reported inconsistent results.MethodsThis study compares the combined use of NAC and surgery with surgery alone for GC by using a meta-analytic approach. We performed an electronic search of PubMed, EmBase, and the Cochrane Library to identify randomized controlled trials (RCTs) on NAC published before Oct 2015. The primary outcome of the studies was data on survival rates for patients with GC. The summary results were pooled using the random-effects model. We included 12 prospective RCTs reporting data on 1538 GC patients.ResultsPatients who received NAC were associated with significant improvement of OS (P = 0.001) and PFS (P < 0.001). Furthermore, NAC therapy significantly increased the incidence of 1-year survival rate (SR) (P = 0.020), 3-year SR (P = 0.011), and 4-year SR (P = 0.001). Similarly, NAC therapy was associated with a lower incidence of 1-year (P < 0.001), 2-year (P < 0.001), 3-year (P < 0.001), 4-year (P = 0.001), and 5-year recurrence rate (P = 0.002). Conversely, patients who received NAC also experienced a significantly increased risk of lymphocytopenia (P = 0.003), and hemoglobinopathy (P = 0.021).ConclusionsThe findings of this study suggested that NAC is associated with significant improvement in the outcomes of survival and disease progression for GC patients while also increasing some toxicity.

HCRP1 downregulation confers poor prognosis and induces chemoresistance through regulation of EGFR-AKT pathway in human gastric cancer.

The current study aims to investigate the biological roles and clinical significance of HCRP1 in human gastric cancer. The expression pattern of HCRP1 in gastric cancer tissue and adjacent non-cancerous tissue was detected by immunohistochemistry. HCRP1 downregulation was found in 57 of 137 human gastric cancer samples and correlated with advanced TNM stage, positive nodal status, and relapse. Log-rank test showed that HCRP1 downregulation also correlated with poor overall survival and reduced relapse-free survival. In addition, we found that HCRP1 overexpression inhibited proliferation, colony formation, and invasion in HGC-27 cells. On the other hand, HCRP1 depletion by small interfering RNA promoted proliferation, colony formation, and invasion in SGC-7901 cells. We also treated gastric cancer cells with cisplatin. MTT and Annexin V/PI analysis were carried out to examine change of chemoresistance. We found that HCRP1 overexpression sensitized HGC-27 cells to cisplatin while its depletion reduced sensitivity in SGC-7901 cells. Moreover, we found that HCRP1 overexpression negatively regulated cyclin D1, MMP-2, p-EGFR, p-ERK, and p-AKT. HCRP1 depletion showed the opposite effects. In conclusion, our results suggest that HCRP1 downregulation might serve as an indicator for poor prognosis in gastric cancer patients. HCRP1 reduces drug resistance through regulation of EGFR-AKT signaling.

Endoglin overexpression mediates gastric cancer peritoneal dissemination by inducing mesothelial cell senescence.

Peritoneal dissemination (PD), which is highly frequent in gastric cancer (GC) patients, is the main cause of death in advanced GC. Senescence of human peritoneal mesothelial cells (HPMC) may contribute to GC peritoneal dissemination (GCPD). In this study of 126 patients, we investigated the association between Endoglin expression in GC peritoneum and the clinicopathological features. The prognosis of patients was evaluated according to Endoglin and ID1 expression. In vitro, GC cell (GCC)-HPMC coculture was established. Endoglin and ID1 expression was evaluated by Western blot. Cell cycle and HPMC senescence were analyzed after harvesting HPMC from the coculture. GCC adhesion and invasion to HPMC were also assayed. Our results showed that positive staining of Endoglin (38%) was associated with a higher TNM stage and higher incidence of GCPD (both P < .05). Kaplan-Meier analysis showed that the patients who were Endoglin positive had a shorter survival time compared with Endoglin-negative patients (P = .02). Using the HPMC and GCC adherence and invasion assay, we demonstrated that transforming growth factor beta 1 (TGF-β)1-induced HPMC senescence was attenuated by silencing the Endoglin expression, which also prevented GCC attachment and invasion. Our study indicated a positive correlation between Endoglin overexpression and GCPD. Up-regulated Endoglin expression induced HPMC senescence via TGF-β1 pathway. The findings suggest that Endoglin-induced HPMC senescence may contribute to peritoneal dissemination of GCCs.

The efficacy and safety of targeted therapy with or without chemotherapy in advanced gastric cancer treatment: a network meta-analysis of well-designed randomized controlled trials

BackgroundAdvanced gastric cancer (AGC) is a severe malignant tumor associated with high mortality. Targeted therapy is an important approach for improving the therapeutic effects of AGC treatment. This study evaluates the efficacy and safety of targeted agents for AGC patients.MethodsPubMed, EmBase, and the Cochrane Library were searched for double-blind randomized controlled trials (RCTs) of AGC treatments published prior to July 2017. Progression-free survival (PFS), overall survival (OS), objective response rate (ORR), and severe adverse effects (AEs) were evaluated to determine the efficacy and safety of targeted agents. A network meta-analysis with a frequentist framework was performed to assess the effects of various targeted agents for AGC treatment.ResultsOur analysis included 16 articles involving 5371 patients and 11 types of agents. The network meta-analysis showed that apatinib (97.5%) was most likely to improve PFS, followed by regorafenib (86.3%) and rilotumumab (65.4%). Apatinib was similarly best for OS outcome, (95.5%) followed by rilotumumab (74.7%) and regorafenib (70%). Apatinib (89.6%) also had the best improvement on ORR, followed by rilotumumab (75.4%) and everolimus (68.4%). Bevacizumab (85.5%) was likely to get the lowest severe AEs, followed by sunitinib (63%).ConclusionsApatinib, regorafenib, and rilotumumab improved patient PFS and OS. When combined with chemotherapy, ramucirumab and rilotumumab had high efficacy but low tolerability, and bevacizumab had moderate efficacy and tolerability for PFS. Without chemotherapy, ramucirumab and regorafenib had relatively high therapeutic efficacy tolerability for PFS.

Association between alcohol consumption and the risk of gastric cancer: a meta-analysis of prospective cohort studies

Alcohol consumption is inconsistently associated with the risk of gastric cancer morbidity and mortality. The aim of this study was to systematically evaluate the association between alcohol consumption on gastric cancer risk. The PubMed, Embase, and Cochrane Library databases were searched from inception through April 2017. Prospective cohort studies evaluating the association between alcohol consumption and risk of gastric cancer which report its effect estimates with 95% confidence intervals (CIs) were included. The results summary was performed using the random-effect model. Twenty-two cohort studies involving 22,545 cases of gastric cancer and 5,820,431 participants were identified and included in our data analysis. Overall, drinking had little or no effect on gastric cancer as compared with non-drinkers. Furthermore, light and moderate alcohol consumption had no significant effect on gastric cancer risk when compared with non-drinkers. However, heavy alcohol consumption was associated with a greater risk of gastric cancer when compared with non-drinkers. The findings of the subgroup analyses indicated that light alcohol consumption was associated with a lower risk of gastric cancer in women, while heavy alcohol consumption was associated with an increased risk of gastric cancer regardless of country, gender, whether the study reported gastric cancer incidence, or whether the study adjusted for body mass index, educational attainment, or physical activity. The findings of this study suggest that light alcohol consumption might play a protective effect on gastric cancer in women, while heavy alcohol consumption is associated with a significantly increased risk of gastric cancer in all subgroups.

Tbx3 overexpression in human gastric cancer is correlated with advanced tumor stage and nodal status and promotes cancer cell growth and invasion

The objective of the current study was to investigate the expression pattern of Tbx3 and its clinicopathological significance in patients with gastric cancer. The expression pattern of Tbx3 in gastric cancer tissues and adjacent noncancerous surface epithelia and mucosal glands was detected by immunohistochemistry. Tbx3 was found to be overexpressed in 46 of 98 human gastric cancer samples, and this correlated with advanced clinical stage, tumor stage, and nodal status. In addition, in the SGC-7901 gastric cancer cell line, Tbx3 overexpression by plasmid transfection promoted growth and invasion. Conversely, depleting Tbx3 expression by small-interfering RNA inhibited proliferation and invasion in BGC-823 cell line. Moreover, Tbx3 accelerated cell cycle progression at the G1/S boundary. Tbx3 also regulated epithelial-to-mesenchymal transition (EMT) to promote cell invasion by repressing E-cadherin expression and increasing expression levels N-cadherin, vimentin. These results indicate that in gastric cancer, Tbx3 plays an important role and might be a useful therapy target.