Expression of HOXC8 is inversely related to the progression and metastasis of pancreatic ductal adenocarcinoma.

BACKGROUND: The transcription factor HOXC8 regulates many genes involved in tumour progression. This study was to investigate the role of HOXC8 in pancreatic ductal adenocarcinoma (PDAC) growth and metastasis. METHODS: The Hoxc8 expression was determined in 15 PDAC cell lines and human specimens by RT-polymerase chain reaction and/or immunohistochemistry. The effects of HOXC8 silencing by RNA interference were investigated by functional tests. RESULTS: The Hoxc8 mRNA expression in PDAC cell lines was negatively related to their growth in vivo. Except for Suit2-007 cells, only those with low Hoxc8 mRNA expression grew in nude rats. Successful down-regulation of HOXC8 expression caused increased proliferation, migration (P ≤ 0.05) and colony formation (P ≤ 0.05) in Suit2-007, Panc-1 and MIA PaCa-2 PDAC cells, respectively. The Hoxc8 mRNA levels in diseased human pancreas tissues were significantly increased over normal in PDAC and autoimmune chronic pancreatitis specimens (P<0.01, respectively), but negatively related to tumour stage (P=0.09). In primary and metastatic tumour samples, immunohistochemical staining for HOXC8 was stronger in surrounding than in neoplastic tissues. Furthermore, grading of primary carcinomas was negatively associated with HOXC8 staining (P=0.03). Liver metastases showed the lowest HOXC8 expression of all neoplastic lesions. CONCLUSION: These data indicate that HOXC8 expression is inversely related to PDAC progression and metastasis.

The Acute Effect of Humic Acid on Iron Accumulation in Rats.

Free iron leads to the formation of pro-oxidant reactive oxygen species (ROS). Humic acids (HAs) enhance permeability of cellular wall and act as a chelator through electron transferring. This study was designed to test chelator effect of HA on iron as well as its anti-oxidant effect against the iron-induced hepatotoxicity and cardiotoxicity. The rats used were randomly divided into four groups (n = 8/group): group I (the control group); group II (the HA group), humic acid (562 mg/kg) was given over 10 days by oral gavage; group III (the iron group), iron III hydroxide polymaltose (250 mg/kg) was given over 10 days by intraperitoneal route; and group IV (the HA plus iron group), received the iron (similar to group II) plus humic acid (similar to those in groups II and III) group. Blood and two tissue samples both from liver and heart were obtained for biochemical and histopathological evaluations. Iron deposition, the iron-induced hepatotoxicity, and cardiotoxicity were demonstrated by histopathological and biochemical manner. However, no significant differences were observed in the serum biochemical values and the histopathological results among the iron and the HA plus iron groups in the liver tissue but not in the heart tissue. The protective effects of humic acid against iron-induced cardiotoxicity were shown but not against hepatotoxicity in our study.

Influence of osteopontin expression on the metastatic growth of CC531 rat colorectal carcinoma cells in rat liver.

Development of hepatic metastasis is responsible for most of colorectal cancer-related deaths. Osteopontin (OPN) is a small integrin-binding N-linked glycoprotein, which plays a crucial role in the formation of hepatic metastasis. This study aimed to suppress Opn expression by an antisense-oligonucleotide (ASO(Opn)) to decrease liver metastasis in vivo. The effect of ASO(Opn) was investigated in vitro in CC531(lacZ) colorectal cancer cells in comparison to sense (SO) or nonsense (NSO) oligomers, by determining mRNA and protein expression levels, as well as cell survival. For in vivo treatment, CC531(lacZ) cells were intraportally inoculated into rats to compare the effects of ASO, SO and NSO oligomers, following prolonged subcutaneous administration by osmotic mini-pumps. The resulting CC531(lacZ) tumor cell load in the liver was measured by a ß-galactosidase assay. Proliferation of CC531(lacZ) cells in vitro was significantly decreased after ASO(Opn) and SO treatment (P<0.001). Liver metastasis development was reduced as long as ASO(Opn) was administered, but this effect was rapidly blunted following the end of the ASO(Opn) administration. In contrast, administration of the SO resulted in a tumor load reduction, which surprisingly surpassed the ASO(Opn) effect in vivo in terms of a long-lasting metastasis suppression, which was accompanied with increased survival of the animals. Administration of the ASO(Opn) in rats was effective in decreasing their liver metastasis. The short-lived effect might be extended by modifications suited to increase the ASOs' half-life. In addition, there was a superior anti-metastatic effect caused by the SO, which has not been reported previously.