Bone marrow-derived dendritic cells pulsed with tumor lysates induce anti-tumor immunity against gastric cancer ex vivo.

AIM: To investigate whether bone marrow-derived denritic cells pulsed with tumor lysates induce immunity against gastric cancer ex vivo. METHODS: c-kit(+) hematopoietic progenitor cells were magnetically isolated with a MiniMACS separator from BALB/c mice bone marrow cells. These cells were cultured with cytokines GM-CSF, IL-4, and TNFalpha to induce their maturation. They were analysed by morphological observation, phenotype analysis, and mixed lymphocyte reaction (MLR). Bone marrow-derived DCs (BM-DCs) were pulsed with tumor cell lysate obtained by rapid freezing and thawing at a 1:3 DC:tumor cell ratio. Finally, cytotoxic T lymphocyte (CTL) activity and interferon gamma (IFNgamma) secretion was evaluated ex vivo. RESULTS: c-kit(+) hematopoietic progenitor cells from mice bone marrow cells cultured with cytokines for 8 d showed the character of typical mature DCs. Morphologically, observed by light microscope, these cells were large with oval or irregularly shaped nuclei and with many small dendrites. Phenotypically, FACS analysis showed that they expressed high levels of Ia, DEC-205, CD11b, CD80 and CD86 antigen, moderate levels of CD40, and negative for F4/80. Functionally, these cells gained the capacity to stimulate allogeneic T cells in MLR assay. However, immature DCs cultured with cytokines for 5 d did not have typical DCs phenotypic markers and could not stimulate allogeneic T cells. Ex vivo primed T cells with SGC-7901 tumor cell lysate-pulsed (TP) DCs were able to induce effective CTL activity against SGC-7901 tumor cells (E:T = 100:1, 69.55% +/- 6.05% specific lysis), but not B16 tumor cells, and produced higher levels of IFNgamma when stimulated with SGC-7901 tumor cells but not when stimulated with B16 tumor cells (1575.31 +/- 60.25 pg/mL in SGC-7901 group vs 164.11 +/- 18.52 pg/mL in B16 group, P < 0.01). CONCLUSION: BM-derived DCs pulsed with tumor lysates can induce anti-tumor immunity specific to gastric cancer ex vivo.

Role of the duodenum in regulation of plasma ghrelin levels and body mass index after subtotal gastrectomy.

AIM: To investigate the role of the duodenum in the regulation of plasma ghrelin levels and body mass index (BMI), and the correlation between them after subtotal gastrectomy. METHODS: Forty-two patients with T0-1N0-1M0 gastric cancer were divided into two groups after gastrectomy according to digestive reconstruction pattern, Billroth I group (n = 23) and Billroth II group (n = 19). Ghrelin levels were determined with radioimmunoassay (RIA) before and on d 1, 7, 30 and 360 after gastrectomy, and BMI was also measured. RESULTS: The two groups had identical postoperative trends in ghrelin alterations during the early stage, both decreasing sharply to a nadir on d 1 (36.7% vs 35.7%), then markedly increasing on d 7 (51.0% vs 51.1%). On d 30, ghrelin levels in the Billroth I group were slightly higher than those in the Billroth II group. However, those of the Billroth I group recovered to 93.6% on d 360, which approached, although lower than, the preoperative levels, and no statistically significant difference was observed. Those of the Billroth II group recovered to only 81.6% and manifested significant discrepancy with preoperative levels (P = 0.033). Compared with preoperative levels, ghrelin levels of the two groups decreased by 6.9% and 18.4% and BMI fell by 3.3% and 6.4%, respectively. The linear regression correlations were revealed in both groups between decrease of ghrelin level and BMI (R1(2) = 0.297, P = 0.007; R2(2) = 0.559, P < 0.001). CONCLUSION: Anatomically and physiologically, the duodenum compensatively promotes ghrelin recovery and accordingly enhances BMI after gastrectomy. Regarding patients with insufficient ghrelin secretion, ghrelin is positively associated with BMI.

Detection of carcinoembryonic antigen mRNA in peritoneal washes from gastric cancer patients and its clinical significance.

AIM: To establish a more sensitive method for detection of free cancer cells in peritoneal washes from gastric cancer patients during surgery and to evaluate its clinical significance. METHODS: The carcinoembryonic antigen (CEA) mRNA levels in peritoneal washes from 65 cases of gastric cancer were detected by real-time RT-PCR. Peritoneal lavage cytology (PLC) was applied simultaneously to detection of free cancer cells.Negative controls included peritoneal washes from 5 cases of benign gastric disease and blood samples from 5 adult healthy volunteers. RESULTS: There was no CEA mRNA in peritoneal washes from benign gastric disease patients and in blood of adult healthy volunteers. The positive percentage of free cancer cells detected by real-time RT-PCR was 47.7% and only 12.3% by PLC. The positive rate of CEA mRNA was significantly related with serosa invasion between peritoneal metastasis and stage of gastric cancer. CONCLUSION: Real-time RT-PCR is a sensitive and rapid method for the detection of free cancer cells in peritoneal washes. The presence of free cancer cells in peritoneal washes is related to the pathologic stage of gastric cancer.

[Influence of digestive tract reconstruction techniques on plasma ghrelin level and body mass index after subtotal gastrectomy].

OBJECTIVE: To study the impact of digestive tract reconstruction techniques on plasma ghrelin level and body mass index (BMI) after subtotal gastrectomy. METHODS: Eighty-one patients undergoing subtotal gastrectomy for T1-3N0M0 gastric cancer were divided into three groups according to digestive tract reconstruction techniques, which included Billroth I group (n=30), Billroth II group (n=25) and Roux-en-Y group(n=26). Plasma ghrelin level was determined by radioimmunoassay preoperatively and one day, one week, half a year, and one year after gastrectomy. BMI was similarly recorded. RESULTS: Plasma ghrelin levels of three groups decreased sharply to nadir one day after operation, which were (34.2±5.2)%, (37.7±4.7)% and (36.5±4.9)% respectively. A week after operation they were (52.6±6.5)%, (48.3±5.7)% and (48.1±6.0)%. There were no statistical difference between groups (P=0.075). Half a year postoperatively, they were (91.7±7.5)%, (80.4±8.1)% and (75.3±8.3)% and a year postoperatively(95.3±5.1)%, (84.5±6.3)% and (79.9±6.7)%, showing that Billroth I group was obviously higher than the other two groups (P<0.01) and Billroth II group was higher than Roux-en-Y group (P<0.05). BMI of three groups at a year after surgery descended by (2.1±1.1)%, (4.5±1.9)% and (5.7±1.8)% respectively, demonstrating statistical difference. Linear regression correlation existed in the three groups between decreasing amplitude of ghrelin and BMI (P<0.01). CONCLUSIONS: Billroth I digestive tract reconstruction takes on the normal anatomy and physiology and therefore promotes compensatory ghrelin secretion. Falling of ghrelin level greatly contributes to the weight loss after subtotal gastrectomy.

[Role of duodenum in regulation of plasma ghrelin level and body mass index after subtotal gastrectomy].

OBJECTIVE: To investigate the role of duodenum in regulation of ghrelin and body mass index (BMI) and the correlation between ghrelin and BMI after subtotal gastrectomy. METHODS: Forty-two patients with T(0-1)N(0-1)M(0) gastric cancer were divided into two groups after gastrectomy according to digestive reconstruction pattern, Billroth I group (n=23) and Billroth II group (n=19) respectively. Plasma ghrelin levels were determined by radioimmunoassay (RIA) before and at day 1, 7, 30 and 360 after gastrectomy,and BMIs were also measured. RESULTS: Two groups had identical postoperative trends in ghrelin alterations during the early stage, both dropping to nadir at day 1 (36.7% vs 35.7%), then markedly increasing at day 7 (51.0% vs 51.1%). At day 30, ghrelin level of Billroth I group was slightly higher than that of Billroth II group. At day 360, ghrelin level of Billroth I group recovered to 93.6%, approaching though lower than preoperative level and no significant difference was displayed, while ghrelin level of Billroth II group recovered only to 81.6% of preoperational level and significant difference existed (P=0.033). Compared with preoperative levels, ghrelin of two groups decreased by 6.9% and 18.4% while BMI by 3.3% and 6.4% respectively, liner regression correlations were revealed in both groups between decrease magnitudes(R(1)(2)=0.297,P=0.00;R(2)(2)=0.559,P<0.001). CONCLUSIONS: Anatomico-physiological duodenum compensatively promotes ghrelin recovery, accordingly enhances BMI after gastrectomy. Regarding patients with insufficient ghrelin secretion, ghrelin is positively correlated with BMI.

[Expression and clinical significance of costimulatory molecule B7-H3 mRNA and B7-H3 protein in gastric carcinoma].

OBJECTIVE: To study the expression of B7-H3 mRNA and B7-H3 protein in gastric carcinoma and their clinical significance. METHODS: The expression of B7-H3 mRNA and B7-H3 protein in gastric carcinoma and the nearby normal tissue of 38 patients was detected by real-time RT-PCR and immunohistochemical assay respectively. RESULTS: B7-H3 mRNA was expressed both in gastric carcinoma and nearby normal tissue, but the expression level in gastric carcinoma was much lower than that in nearby normal tissue. There were no significant differences of B7-H3 mRNA expression among gender, age, histological type, tumor size, lymph node metastasis and invasive depth (all P >0.05). The positive rate of B7-H3 protein expressed in gastric carcinoma was 39.5%. There were no significant differences of B7-H3 protein expression among gender, age, histological type, tumor size, lymph node metastasis and invasive depth (all P >0.05), but there were significant differences among groups of clinical stage (P=0.022) and pathological grade (P=0.039). Kaplan-Meier analysis revealed that disease-free survival or overall survival of the patients with positive B7-H3 expression were significantly longer than those with negative B7-H3 expression (P=0.009 and P=0.010 respectively). CONCLUSION: Detection of B7-H3 expression in gastric carcinoma will be beneficial to the judgment of the prognosis of gastric carcinoma and the choice of individualized treatment.