ABSTRACT
Purpose@#Circular RNAs (circRNAs) are a new class of RNA molecules whose function is largely unknown. There is a growing evidence that circRNAs play an important regulatory role in the progression of a variety of human cancers. However, the exact roles and the mechanisms of circRNAs in gastric cancer are not clear. In this study, we aimed to elucidate the mechanism of hsa_circ_0005556. @*Materials and Methods@#Real-time quantitative polymerase chain reaction was used to detect the expression of hsa_circ_0005556, miR-4270, and matrix metalloproteinase-19 (MMP19) in gastric cancer tissues and cell lines. The expression of hsa_circ_0005556 in gastric cancer cells was silenced by lentivirus, and cell proliferation, invasion, migration, and tumorigenesis in nude mice were assessed to evaluate the function of hsa_circ_0005556 in gastric cancer. @*Results@#The expression of hsa_circ_0005556 in gastric cancer tissues and gastric cancer cell lines was higher compared to normal controls. In vitro, the downregulation of hsa_ circ_0005556 significantly inhibited proliferation, migration, and invasion of gastric cancer cells. In vivo, the downregulation of hsa_circ_0005556 suppressed tumor growth in nude mice. @*Conclusions@#Our study shows that the hsa_circ_0005556/miR-4270/MMP19 axis is involved in proliferation, migration, and invasion of gastric cancer cells through the competing endogenous RNA (ceRNA) mechanism.
ABSTRACT
Objective To explore the risk factors of liver metastasis from colorectal cancer. Methods The clinic data of 1341 patients with colorectal cancer who had been admitted to our department from January 1989 to December 2004 were analyzed retrospectively. Results The incidence of the liver metastasis from colorectal cancer was 11.56% (155/1341). Univariate analysis showed that sex, location and size of the primary tumor site, regional lymph node metastasis, infiltration depth of the bowel wall, involvement of the adjacent viscera, complications and peritoneal implantation were relevant to liver metastasis (X2=6.517, 10.208, 11.173, 42.160, 80.731,6.593, 3.887, 14.352, P < 0.05). Logistic regression analysis showed that sex, regional lymph node metastasis, infiltration depth of the bowel wall, complications and primary tumor site were correlated with liver metastasis ( b = 0.655, -0.488, 1.355, -0.752, 0.273, P <0.05). Conclusions Male patients, patients with regional lymph node metastasis or with involvement of tissues out of the serosa have higher chance of liver metastasis from coloreetal cancer. Patients with colon cancer are apt to develop liver metastasis than those with rectal cancer. The incidence of liver metastasis in colorectal cancer patients complicated with other diseases is low.