Gastrointestinal stromal tumors: Fibrinogen levels are associated with prognosis of patients as blood-based biomarker.

Improved prediction of prognosis for primary gastrointestinal stromal tumors (GISTs) after curative resection is an important goal in clinical practice. Coagulation factor of fibrinogen may inform prognosis of tumor patients as blood-based biomarker. Here, we aimed to analyze the prognostic value of fibrinogen levels in patients with GIST and to explore potential threshold of fibrinogen on postoperative clinical outcome.A retrospective study was performed including data from 91 patients with newly diagnosed GISTs who underwent curative resection. Patients were followed-up for a median period of 2 years. Cox regression and competing risk analysis were applied to study the association between fibrinogen and risk of death or recurrence. Smoothing plot and threshold effect analysis were applied to learn the relationship further and explore potential threshold.High levels of fibrinogen are associated with decreased overall survival (OS) and recurrence free survival (RFS) in patients with GISTs. We discovered a nonlinear relationship between levels of fibrinogen and the risk of death or recurrence. Further, we detected a threshold for fibrinogen (3.7 g/L) on the prognosis of GISTs patients. When fibrinogen was above the inflection point, the increase in fibrinogen levels was strongly associated with increase in the risk of death or recurrence.Elevated fibrinogen can serve as an independent prognostic biomarker for a worse clinical outcome in GIST patients.

Laparoscopic Versus Open Resection of Gastric Gastrointestinal Stromal Tumors Larger Than 5 cm: A Single-Center, Retrospective Study.

BACKGROUND: The technical feasibility and oncological safety of laparoscopic surgery for gastric gastrointestinal stromal tumors (GISTs) larger than 5 cm has not been adequately studied. Therefore, we performed this retrospective study to investigate the clinical outcomes of gastric GIST patients treated with laparoscopic surgery compared with those who underwent open surgery. METHODS: We retrospectively evaluated the outcomes of 48 consecutive patients who underwent gastric resection for gastric GISTs larger than 5 cm. The patients were divided into 2 groups based on the surgery performed: the laparoscopic resection group (LAPG) and the open resection group (OG). We assessed all available patient data, including baseline information, tumor characteristics, surgical outcomes, pathological results, postoperative complications, and long-term patient survival. RESULTS: The 2 groups had similar baseline data. No differences were found in tumor size, location, mitotic count, and risk grade according to Fletcher's risk classification. The LAPG was superior to the OG in blood loss, time to first flatus, time to oral intake, and length of postoperative hospital stay. Perioperative complications, recurrence rate, and long-term survival, however, did not differ significantly between the groups. The mean operation time in the LAPG was 28 minutes longer than that in the OG. CONCLUSIONS: In patients with primary gastric GISTs larger than 5 cm, laparoscopic resection is a technically feasible and oncologically safe surgery when performed by experienced surgeons.

Role of Nampt and Visceral Adiposity in Esophagogastric Junction Adenocarcinoma.

Nampt including eNampt and iNampt may contribute to mediating obesity-associated cancers. This study investigated the role of Nampt in esophagogastric junction adenocarcinoma (EGA), a cancer strongly correlated with obesity. Visceral adiposity was defined by waist circumference or VFA. eNampt in sera were measured by enzyme-linked immunosorbent assay. iNampt expression in EGA was determined by PCR, western blot, and immunohistochemistry. Sera eNampt were significantly elevated in these overweight and obese patients, especially for viscerally obese patients, and positively correlated with BMI, waist circumference, VFA, and also primary tumor, regional lymph nodes, and TNM stage (P < 0.05). iNampt expression in both the mRNA and protein levels was upregulated in EGAs (P < 0.05). iNampt staining was found primarily in the cytoplasm and nuclei and significantly associated with tumor, lymph nodes, and TNM stage and also correlated positively with serum eNampt, BMI, total fat area, VFA, superficial fat area, and waist circumference (P < 0.05). iNampt, eNampt, tumor, lymph nodes, and TNM stage correlated to the survival of EGAs, and iNampt expression and TNM stage affected the prognosis independently (P < 0.05). This study highlighted the association of eNampt/iNampt with visceral obesity and a potential impact on the biology of EGA.

MicroRNA-125b promotes invasion and metastasis of gastric cancer by targeting STARD13 and NEU1.

MicroRNAs have been documented playing key roles in cancer development and progression. Here, we investigate the role of miR-125b in gastric cancer metastasis. We found that the expression of miR-125b was up-regulated in gastric cancer tissue specimens compared with their corresponding nontumorous tissues, and the up-regulated miR-125b level was significantly associated with TNM stage and lymph node-metastasis. Overexpression of miR-125b promoted gastric cancer cell migration and invasion in vitro and metastasis in vivo. STARD13 and NEU1 were identified as direct target genes of miR-125b by luciferase assays, and they were involved in the cell migration and invasion regulated by miR-125b in gastric cancer. Taken together, miR-125b functions as an oncogene in gastric cancer and represents a new potential therapeutic target for gastric cancer.

Recovery of Urinary Functions After Laparoscopic Total Mesorectal Excision for T4 Rectal Cancer.

BACKGROUND: Postoperative urinary dysfunction after total mesorectal excision (TME) is lessened by preservation of the autonomic nerves, but in T4 rectal tumors such injury often cannot be prevented. This retrospective study evaluated the recovery of urinary function of patients with injury to a single pelvic autonomic nerve subsequent to laparoscopic TME, relative to patients without nerve damage. METHODS: Patients with T4 rectal cancer who underwent laparoscopic TME were divided according to the presence of a single pelvic autonomic nerve injury (37 cases) or no injury to autonomic nerves (54 cases; control). Urinary function was evaluated before surgery and at 1 and 6 months after surgery based on catheter indwelling time, urodynamics, International Prostate Symptom Score (IPSS; men only), and Urogenital Distress Inventory (UDI-6) score (women). RESULTS: One month after surgery in the injured and control groups, the postoperative catheter indwelling time was 6.2 ± 2.0 and 1.9 ± 1.2 days, respectively; the maximal urinary flow rates were 16.6 ± 5.8 and 19.7 ± 5.5 mL/s; the voided volumes were 181.6 ± 65.9 and 211.7 ± 63.2 mL; and the residual volumes were 15.0 ± 8.5 and 10.8 ± 8.0 mL. However, at the 6-month follow-up, all urodynamic parameters of the two groups were statistically similar and indicated recovery, and the IPSS and UDI-6 scores were also not statistically different. CONCLUSION: Damage to a single pelvic autonomic nerve during laparoscopic TME does not lead to long-term urinary dysfunction.

HOTTIP and HOXA13 are oncogenes associated with gastric cancer progression.

A long non-coding RNA named HOTTIP (HOXA transcript at the distal tip) coordinates the activation of various 5' HOXA genes which encode master regulators of development through targeting the WDR5/MLL complex. HOTTIP acts as an oncogene in several types of cancers, whereas its biological function in gastric cancer has never been studied. In the present study, we investigated the role of HOTTIP in gastric cancer. We found that HOTTIP was upregulated in gastric cancer cell lines. Knockdown of HOTTIP in gastric cancer cells inhibited cell proliferation, migration and invasion. Moreover, downregulation of HOTTIP led to decreased expression of homeobox protein Hox-A13 (HOXA13) in gastric cancer cell lines. HOXA13 was involved in HOTTIP­induced malignant phenotypes of gastric cancer cells. Our data showed that the levels of HOTTIP and HOXA13 were both markedly upregulated in gastric cancer tissues compared with their counterparts in non-tumorous tissues. Furthermore, the expression levels of HOTTIP and HOXA13 were both higher in gastric cancer which was poorly differentiated, at advanced TNM stages and exhibited lymph node-metastasis. Spearman analyses indicated that HOTTIP and HOXA13 had a highly positive correlation both in non-tumor mucosae and cancer lesions. Collectively, these findings suggest that HOTTIP and HOXA13 play important roles in gastric cancer progression and provide a new insight into therapeutic treatment for the disease.

The Prognostic Role of SIRT1-Autophagy Axis in Gastric Cancer.

Aim. Sirtuin 1 (SIRT1) can induce autophagy through deacetylation of Beclin-1 and other autophagy mediators. However, the relationship between SIRT1 and autophagy in GC has not been defined. Therefore, the aim of this study was to confirm the prognostic value of SIRT1 and Beclin-1 and their relationship in GC patients. Methods. Transmission electron microscopy (TEM) was performed to examine the autophagy in GC patients. Immunohistochemistry was used to examine the expression of SIRT1, Beclin-1 in GC, and adjacent nonneoplastic mucosa. Results. In 7 out of 8 GC patients' samples examined by TEM, more autophagic vesicles were observed in GC tissues compared to adjacent nonneoplastic mucosa tissue. A positive correlation between SIRT1 and Beclin-1 expression was observed. Furthermore, Beclin-1 or SIRT1 expression alone or their combined expression were significantly correlated with advanced clinicopathological parameters. High Beclin-1 and SIRT1 expression alone and their combined high expression predicted shorter overall survival and relapse-free survival. Both high Beclin-1 and SIRT1 expressions were independent prognostic factors for poor survival of GC. Conclusions. Based on our results we can conclude that SIRT1 and Beclin-1 expression alone or in combination can be used as prognostic indicator and may represent new therapeutic targets in GC.

ß-elemene enhances the radiosensitivity of gastric cancer cells by inhibiting Pak1 activation.

AIM: To explore the potential of ß-elemene as a radiosensitizer for gastric cancer cells and the underlying mechanisms. METHODS: SGC7901, MKN45, MKN28, N87, and AGS human gastric cancer cell lines were used to screen for radioresistant gastric cancer cell lines. A 3-(4,5-dimeth-ylthiazol-2-yl)-2,5-diphenyltetrazolium (MTT) assay was used to determine the effects of ß-elemene and IPA-3 on cell viability in MKN45 and SGC7901 gastric cancer cell lines. A clonogenic survival assay and annexin V-FITC/PI apoptosis detection assay were used to evaluate cellular radiosensitivity and radiation-induced cell death, respectively. A proteomic method, isobaric tags for relative and absolute quantitation (iTRAQ), was employed to screen the proteins regulated by ß-elemene pretreatment prior to ionizing radiation (IR) in SGC7901 gastric cancer cell line. IPA-3 was used as a specific small molecule inhibitor of p21-activated protein kinase 1 (Pak1) to target Pak1 signaling. Protein levels of PAK1IP1 (p21-activated protein kinase-interacting protein 1), total Pak1 (t-Pak1), phospho-Pak1 (T423), phospho-ERK1/2 (Thr202/Tyr204), and cleaved caspase-3 (17 kDa) were assessed by western blotting. RESULTS: MKN45 and SGC7901 gastric cancer cell lines were relatively more resistant to IR. ß-elemene pretreatment decreased clonogenic survival following IR in MKN45 and SGC7901 gastric cancer cell lines. Additionally, ß-elemene pretreatment prior to IR increased radiation-induced cell death compared with IR alone in MKN45 (10.4% ± 0.9% vs 34.8% ± 2.8%, P < 0.05) and SGC7901 (11.6% ± 0.9% vs 46.7% ± 5.2%, P < 0.05) human gastric cancer cell lines, respectively, consistent with the level of cleaved caspase-3 (17 kDa). Through iTRAQ analysis and western blot validation, we found that ß-elemene upregulated PAK1IP1 and downregulated phospho-Pak1 (T423) and phospho-ERK1/2 in SGC7901 gastric cancer cells. IR increased the level of phospho-Pak1 (T423). Pretreatment with ß-elemene decreased radiation-induced Pak1 and ERK1/2 phosphorylation. Inhibition of Pak1 using IPA-3 decreased clonogenic survival following IR. In addition, IPA-3 increased radiation-induced cell death in MKN45 (13.4% ± 0.3% vs 26.6% ± 1.0%, P < 0.05) and SGC7901 (16.0% ± 0.6% vs 37.3% ± 1.7%, P < 0.05) gastric cancer cell lines, respectively, consistent with the level of cleaved caspase-3 (17 kDa). Western blotting showed that IPA-3 decreased radiation-induced Pak1 and ERK1/2 phosphorylation. CONCLUSION: This is the first demonstration that ß-elemene enhances radiosensitivity of gastric cancer cells, and that the mechanism involves inhibition of Pak1 signaling.

[Effects of ß-elemene on proliferation and apoptosis of SGC7901 gastric cancer cells in vitro and the underlying mechanisms].

OBJECTIVE: To investigate the effects of ß-elemene in suppressing the proliferation and apoptosis of SGC7901 gastric cancer cells in vitro and explore the underlying mechanisms. METHODS: Using MTT assay, flow cytometry, and clonogenic survival assay, we assessed the effects of ß-elemene on the viability, apoptosis, cell cycle distribution, and clonogenic survival of gastric cancer SGC7901 cells and gastric mucosal epithelial GES-1 cells. Western blotting was employed to determine the changes in the protein expression profiles in SGC7901 cells in response to ß-elemene treatment. RESULTS: ß-elemene significantly suppressed the cell viability and increased the apoptosis of SGC7901 cells, and these effects were less obvious in GES-1 cells. ß-elemene decreased clonogenic survival of SGC7901 cells, increased the proportion of G2/M phase cells, decreased the expression of Bcl-2, and increased the expression of Bax and cleaved caspase-3. ß-elemene did not obviously affect the expression of total p21-activated protein kinase 1 (Pak1) but decreased the level of phospho-Pak1 (Thr423) and phospho-ERK1/2 (Thr202/Tyr204) in SGC7901 cells. CONCLUSION: ß-elemene inhibits the proliferation and induces apoptosis of gastric cancer cells possibly by inhibiting Pak1/ERK signaling and regulating apoptosis-associated proteins such as Bcl-2 and Bax.

SIRT1 is a regulator of autophagy: Implications in gastric cancer progression and treatment.

Silent mating type information regulation 1 (SIRT1) is implicated in tumorigenesis through its effect on autophagy. In gastric cancer (GC), SIRT1 is a marker for prognosis and is involved in cell invasion, proliferation, epithelial-mesenchymal transition (EMT) and drug resistance. Autophagy can function as a cell-survival mechanism or lead to cell death during the genesis and treatment of GC. This functionality is determined by factors including the stage of the tumor, cellular context and stress levels. Interestingly, SIRT1 can regulate autophagy through the deacetylation of autophagy-related genes (ATGs) and mediators of autophagy. Taken together, these findings support the need for continued research efforts to understand the mechanisms mediating the development of gastric cancer and unveil new strategies to eradicate this disease.

[Down-expression of FOXA2 in gastric adenocarcinoma].

OBJECTIVE: To investigate the expression of FOXA2 in human gastric adenocarcinoma and its correlation with cell migration and invasion. METHODS: Fifty-six pairs of gastric adenocarcinoma and matched tumor-adjacent tissues were freshly collected. The expressions of FOXA2 and epithelial cadherin (E-cadherin) in the gastric specimens were detected using immunohistochemistry. Western blotting was performed to test FOXA2 and E-cadherin expressions in different gastric cancer cell lines. FOXA2 was over-expressed in MKN-45 cells. TranswellTM assays were performed to observe gastric cancer cell migration and invasion in vitro. Spearman rank correlation coefficient was used for correlation analysis. RESULTS: The expressions of FOXA2 and E-cadherin in gastric adenocarcinoma were significantly lower than those in matched tumor-adjacent noncancerous tissues. FOXA2 was positively correlated with E-cadherin expression in gastric adenocarcinoma tissues. Clinical analysis suggested that FOXA2 expression was prominently associated with tumor differentiation, infiltration depth, lymph node metastasis and TNM stage, respectively. The lowest expressions of FOXA2 and E-cadherin were found in highly invasive gastric cancer MKN-45 cell line; the highest expressions of FOXA2 and E-cadherin were observed in low metastatic gastric cancer N-87 cell line. Over-expression of FOXA2 significantly increased the expression of E-cadherin protein and obviously inhibited cell migration and invasion in MKN-45 cells. CONCLUSION: Expression of FOXA2 is reduced in gastric adenocarcinoma tissues and its low-expression is correlated with malignant clinical pathological features. Over-expression of FOXA2 in MKN-45 cells up-regulates E-cadherin expression and inhibits gastric cancer cell migration and invasion.

MicroRNA-153 acts as a prognostic marker in gastric cancer and its role in cell migration and invasion.

MicroRNA (miRNA)-153 (miR-153) has been considered as a novel tumor-related miRNA and is found to be significantly deregulated in human cancers. In this study, we found that the expression levels of miR-153 were obviously lower in gastric cancer tissues than those in matched adjacent nontumor tissues. Otherwise, miR-153 was expressed at significantly lower levels in aggressive tumor tissues. Clinical association analysis indicated that low expression of miR-153 was prominently correlated with poor prognostic features in gastric cancer. Furthermore, we demonstrated that the low expression of miR-153 was correlated with short 5-year survival of gastric cancer patients. Multivariate Cox regression analysis indicated that miR-153 was an independent prognostic marker in gastric cancer. Our in vitro studies showed that upregulation of miR-153 reduced cell migration and invasion in MKN-45 cells. Meanwhile, downregulation of miR-153 promoted SGC-7901 cell migration and invasion. An inverse correlation between miR-153 and SNAI1 expression was observed in gastric cancer tissues. In addition, upregulation of miR-153 reduced SNAI1 expression and subsequently suppressed epithelial-mesenchymal transition (EMT) with elevated expression of E-cadherin and reduced expression of vimentin in MKN-45 cells. Furthermore, downregulation of miR-153 increased SNAI1 expression and promoted EMT in SGC-7901 cells. In conclusion, miR-153 is an independent prognostic marker for predicting survival of gastric cancer patients and may promote gastric cancer cell migration and invasion, by inhibiting SNAI1-induced EMT.

Anticancer effects of ß-elemene in gastric cancer cells and its potential underlying proteins: a proteomic study.

Gastric cancer is a common malignancy with a poor prognosis. ß-elemene is a broad-spectrum anticancer drug extracted from the traditional Chinese medicinal herb Curcuma wenyujin. In the present study, we investigated the anticancer effects of ß-elemene in gastric cancer cells and the potential proteins involved. Human SGC7901 and MKN45 gastric cancer cells were treated with different concentrations of ß-elemene. Cell viability, clonogenic survival and apoptotic cell death were assessed. ß-elemene inhibited viability and decreased clonogenic survival of gastric cancer cells in a dose-dependent manner. Apoptosis induction contributed to the anticancer effects. We then employed a proteomic method, isobaric tags for relative and absolute quantitation (iTRAQ), to detect the proteins altered by ß-elemene. In total, 147 upregulated proteins and 86 downregulated proteins were identified in response to ß-elemene treatment in SGC7901 gastric cancer cells. Among them, expression of p21-activated protein kinase­interacting protein 1 (PAK1IP1), Bcl-2-associated transcription factor 1 (BTF) and topoisomerase 2-α (TOPIIα) were validated by western blot analyses and the trends were consistent with iTRAQ results. Top pathways involved in ß-elemene treatment in SGC7901 gastric cancer cells included ribosome signaling, peroxisome proliferator-activated receptors (PPARs) signaling pathway, regulation of actin cytoskeleton, phagosome, biosynthesis and metabolism of some amino acids. Collectively, our results suggest a promising therapeutic role of ß-elemene in gastric cancer. The differentially expressed proteins provide further insight into the potential mechanisms involved in gastric cancer treatment using ß-elemene.

[Enhancement of gastric cancer MKN28 cell line radiosensitivity induced by ß-elemene].

OBJECTIVE: To study radiation-enhancing effects on human gastric cancer MKN28 cell line and underlying mechanisms of ß-elemene. METHODS: Inhibition of MKN28 cell proliferation at different concentrations of ß-elemene was assessed using the methyl thiazolyl blue colorimetric method (MTT method), with calculation of IC50 value and choice of 20% of the IC50 as the experimental drug concentration. Irradiation group and ß-elemene+irradiation group were established, and the cell survival fraction (SF) was calculated from flat panel colony forming analysis, and fitted by the 'multitarget click mathematical model'. Draw the survival curve and get the radiobiological parameters D0, Dq, SF2, N and SER. Flow cytometry (FCM) was used to detect changes in the cell cycle and cell apoptosis rates was detected by Annexin-V/PI assay. RESULTS: ß-elemene exerted inhibitory effects on proliferation of gastric cancer MKN28 cells, with an IC50 of 45.6 mg/L and we chose 8 mg/L as the experimental concentration. The cell survival fraction of MKN28 cells with irradiation decreased significantly after treated with ß-elemene; D0, Dq decreased, SER = 1.3. After combined treatment of ß-elemene+irradiation, the results of FCM showed that cells could be arrested in the G2/M phase and the cell apoptosis increased significantly. CONCLUSIONS: ß-elemene can enhance the radiosensitivity of gastric cancer MKN28 cell line. Mechanistically, ß-elemene mainly influences the cell cycle distribution of MKN28 cells by inducing G2/M phase arrest, inhibits the repair of sublethal damage and induces cell apoptosis to enhance the killing effects of radioactive rays.

Diet-induced obesity promotes murine gastric cancer growth through a nampt/sirt1/c-myc positive feedback loop.

Obesity increases the risk of gastric cancer and may promote its growth, as was recently demonstrated by our novel in vivo mouse model. However, the underlying mechanisms of this correlation remain unclear. The purpose of this study was to investigate the precise effects of obesity on gastric cancer growth and to elucidate the potential molecular mechanisms. Diet-induced obese mice were insulin-resistant, glucose-intolerant and had high serum visfatin concentration. In the subcutaneous mouse model, tumors were more aggressive in diet-induced obese mice compared with lean mice. Tumor weights showed a significant positive correlation with mouse body weights, as well as serum insulin and visfatin concentrations. Immunohistochemical staining showed that the expression levels of iNampt, Sirt1 and c-MYC proteins were upregulated in the subcutaneous tumors from obese mice compared to those from lean animals. Furthermore, obesity not only prompted significantly murine forestomach carcinoma cell migration, proliferation, but also affected cellular apoptosis and cell cycle by endocrine mechanisms. These were associated with increased expression of the pro-survival nampt/sirt1/c-myc positive feedback loop confirmed by RT-PCR and western blotting. These results suggested that diet-induced obesity could promote murine gastric cancer growth by upregulating the expression of the nampt, sirt1 and c-myc genes.

Diet-induced obesity potentiates the growth of gastric cancer in mice.

Obesity increases the risk of gastric cancer and may affect its development and progression, however, the mechanisms underlying this association are completely unknown. The purpose of the current study was to investigate the effect of obesity on gastric cancer growth by adopting a novel in vivo model. Diet-induced obese and lean mice were inoculated with murine forestomach carcinoma cells, and studied for 2 weeks. Tumor histology, cellular proliferation and apoptosis were evaluated. Serum glucose, insulin, visfatin levels and peripheral CD3(+), CD4(+/-), CD8(+/-) lymphocytes were assayed. All mice were alive and developed no metastasis, a greater number of obese mice developed palpable tumors than lean mice. The tumors from obese mice had a larger volume, greater intratumoral adipocyte mass, and exhibited a higher proliferation and reduced apoptosis rate compared to those of lean animals. Both serum insulin and visfatin concentrations correlated positively with tumor proliferation and negatively with tumor apoptosis. Obese mice had a significantly lower level of CD3(+), CD3(+)CD4(+) T lymphocytes, and a lower level of CD4(+)/CD8(+) in peripheral blood compared to these lymphocyte levels in the lean mice. In conclusion, the altered adipocytokine milieu and insulin resistance observed in obesity may lead directly to alterations in the tumor microenvironment and cell immunity for avoiding cancer, thereby, promoting gastric cancer survival and growth.