A synergistic antitumor effect of interleukin-2 addition with CD80 immunogene therapy for peritoneal metastasis of gastric carcinoma

Molecular biology and immunology of gastric cancer peritoneal metastasis

Peritoneal metastases occur in 55-60% of patients with gastric cancer (GC) and are associated with a 2% 5-year overall survival rate. There are limited treatment options for these patients, and no targeted therapy or immunotherapy is available. Rational therapeutic targets remain to be found. In this review, we present the published literature and our own recent experience in molecular biology to identify important molecules and signaling pathways as well as cellular immunity involved in the peritoneal metastasis of GC. We also suggest potential novel strategies for improving the outcomes of GC patients with peritoneal metastasis.

Genetic variants in gastric cancer: Risks and clinical implications

Cancer is a multifactorial disease that involves many molecular alterations. Gastric cancer (GC) is the third leading cause of cancer death worldwide. GC is a highly heterogeneous disease with different molecular and genetics features. Therefore, this review focuses on an overview of the genetic aspects of gastric cancer by highlighting the important impact and role of deletions and/or duplications of chromosomal segments, genomic variants, H. pylori infection and interleukin variants, as found in gene expression and newly proposed molecular classification studies. The challenge is to better understand the mechanisms and different pathways that lead to the development and progression of GC.

Correlation of βig-h3 expression in peritoneal mesothelial cells with pathological parameters and peritoneal metastasis in gastric cancer

AIM: To determine the expression of βig-h3 in peritoneal mesothelial cells in gastric cancer and to explore its relation to pathological parameters and peritoneal metastasis.

METHODS: Peritoneal tissue and peritoneal washing fluid samples were collected during operation from 75 patients with gastric cancer and 14 patients with benign gastric lesions. The expression of βig-h3 in peritoneal mesothelial cells was measured immunohistochemically. The mRNA levels of CEA in ascites and peritoneal washing fluid were measured by RT-PCR. Peritoneal lavage cytological (PLC) examination and pathological examination were also performed.

RESULTS: βig-h3 was positively expressed in the peritoneal tissue in 29 patients with gastric cancer and 1 with benign gastric lesions, and the positive rate was significantly different between the two groups (P = 0.030). In the gastric cancer group, 13 patients had evident peritoneal metastasis, 20 were positive for PLC, and 32 were positive for CEA mRNA. The positive rate of βig-h3 expression was significantly positively correlated with deep invasion (P = 0.016), serious serous type (P = 0.037), peritoneal metastasis (P = 0.002), PLC (+) (P = 0.005), and CEA mRNA (+) (P = 0.027).

CONCLUSION: βig-h3 expression in peritoneal mesothelial cells in gastric cancer patients is closely related with peritoneal metastasis, representing a marker of biological behavior of gastric cancer.

Gastric cancer cell supernatant causes apoptosis and fibrosis in the peritoneal tissues and results in an environment favorable to peritoneal metastases, in vitro and in vivo

Background

In this study, we examined effects of soluble factors released by gastric cancer cells on peritoneal mesothelial cells in vitro and in vivo.

Methods

HMrSV5, a human peritoneal mesothelial cell line, was incubated with supernatants from gastric cancer cells. Morphological changes of HMrSV5 cells were observed. Apoptosis of HMrSV5 cells was observed under a transmission electron microscope and quantitatively determined by MTT assay and flow cytometry. Expressions of apoptosis-related proteins (caspase-3, caspase-8, Bax, bcl-2) were immunochemically evaluated.

Results

Conspicuous morphological changes indicating apoptosis were observed in HMrSV5 cells 24 h after treatment with the supernatants of gastric cancer cells. In vivo, peritoneal tissues treated with gastric cancer cell supernatant were substantially thickened and contained extensive fibrosis.

Conclusions

These findings demonstrate that supernatants of gastric cancer cells can induce apoptosis and fibrosis in HMrSV5 human peritoneal mesothelial cells through supernatants in the early peritoneal metastasis, in a time-dependent manner, and indicate that soluble factors in the peritoneal cavity affect the morphology and function of mesothelial cells so that the resulting environment can become favorable to peritoneal metastases.

Advances in the treatment of peritoneal metastasis of gastric cancer

The clinical curative effect for patients suffering from peritoneal metastasis of gastric cancer is relatively poor. Early diagnosis and effective treatment are very important for improving the survival rate in these patients. In recent years, in the light of non-radical treatment of peritoneal metastasis, peritoneal resection has been adopted with a view to alleviating the tumor burden to the greatest extent, combined with intraperitoneal chemotherapy and whole-body intravenous chemotherapy during the entire surgical period. In the meantime, with the better understanding of the pathogenesis of peritoneal metastasis of gastric cancer, some experimental studies on immunotherapy and gene therapy have also provided new thoughts and methods for the treatment of this disease. In this paper, we review the recent advances in the treatment of peritoneal metastasis of gastric cancer.

Destruction of gastric cancer cells to mesothelial cells by apoptosis in the early peritoneal metastasis

This study examined the mechanism by which the gastric cancer cells lead to early peritoneal metastasis. HMrSV5 cells, a human peritoneal mesothelial cell line, were co-incubated with the supernatants of gastric cancer cells. Morphological changes of HMrSV5 cells were observed. The cell damage was quantitatively determined by MTT assay. The apoptosis of HMrSV5 cells was observed under transmission electron microscope. Acridine orange/ethidium bromide-stained condensed nuclei was detected by fluorescent microscopy and flow cytometry. The expressions of Bcl-2 and Bax was immunochemically evaluated. The results showed that conspicuous morphological changes of apoptosis were observed in HMrSV5 cells 24 h after treatment with the supernatants of gastric cancer cells. The supernatants could induce apoptosis of HMrSV5 cells in a time-dependent manner. The supernatants could up-regulate the expression of Bax and suppress that of Bcl-2 in HMrSV5 cells. These findings demonstrated that gastric cancer cells can induce the apoptosis of HPMCs through supernatants in the early peritoneal metastasis. The abnormal expressions of Bcl-2 and Bax may contribute to the apoptosis. Anti-apoptosis drugs promise to be adjuvant chemotherapeutic agents in the treatment of peritoneal metastasis of gastric cancer.