Advances in understanding the molecular mechanism of pancreatic cancer metastasis

BACKGROUND： Pancreatic cancer（PC） is usually diagnosed at the late-stage and therefore, has widespread metastasis and a very high mortality rate. The mechanisms underlying PC metastasis are not well understood. Recent advances in genomic sequencing have identified groups of gene mutations that affect PC metastasis, but studies elucidating their roles are lacking. The present review was to investigate the molecular mechanisms of PC metastasis.DATA SOURCES： Relevant articles on PC metastasis were searched in MEDLINE via Pub Med prior to April 2015. The search was limited in English publications.RESULTS： PC metastatic cascades are multi-factorial events including both intrinsic and extrinsic elements. This review highlights the most important genetic alterations and other mechanisms that account for PC invasion and metastasis, with particular regard to epithelial-mesenchymal transition, inflammation, stress response, and circulating tumor cells.CONCLUSIONS： Analyses of relevant gene functions and signaling pathways are needed to establish the gene regulatory network and to define the pivotal modulators. Another promising area of study is the genotyping and phenotyping of circulating tumor cells, which could lead to a new era of personalized therapy by identifying specific markers and targets.

A STUDY OF THE FORMATION OF LIVER METASTASIS AND ITS MECHANISM USING THE INTRASPLENIC INOCULATION OF CANCER CELLS

In order to establish an animal model with hepatic metastasis intrasplenic inoculation of carcinoma cells from murine uterine cervical carcinoma (U14) was employed. Results showed a high incidence of hepatic metastasis could be obtained through the intrasplenic inoculation of 1 × 106 carcinoma cells. Removal of the primary carcinoma through splenec-tomy at different intervals after intrasplenic inoculation proved that the hepatic metastatic mechanism was not due to mechanical pressure but occurred spontaneously. This experimental model provides a useful means for studying the mechanism and prevention of hepatic metastasis.

The cellular and molecular mechanism of laminin glycopeptides on anti -metastasis

To further study the anti metastasis mechanism of laminin glycopeptides on carcinoma cell proliferation, apoptosis and the secretion of matrix metalloproteinases Methods Human hepatocellular carcinoma cells in serum free medium were incubated on laminin coated substrate with or without laminin glycopeptides at a final concentration of 50?μg/ml The total number of surviving cells after incubating for the indicated time was assayed by MTT assay DNA synthesis of the incubated cells was detected by 3H TdR incorporation Cell cycle was analysed by FACS The mitotic index of Giemsa stained cells was assessed Cell apoptosis was detected by both FACS and an acridine orange staining method Matrix metalloproteinase secretion was analysed by gelatin zymography Results The total number of surviving cells incubated on laminin in the absence of laminin glycopeptides was significantly larger than that in the presence of laminin glycopeptides Laminin promoted 3H TdR incorporation of carcinoma cells, decreased the percentage of cells in G1 phase and increased the percentage of cells in S phase In contrast, laminin glycopeptides could inhibit the effect of laminin as shown by 3H TdR incorporation and cell cycle analysis The percentage of cells in G2+M phase and the mitotic index among various groups showed no significant difference Matrix metalloproteinases secretion from cells treated by laminin glycopeptides was much less compared to that without the treatment by laminin glycopeptides Conclusion Laminin may stimulate cell proliferation, while laminin glycopeptides could significantly inhibit the effect of laminin by inhibiting DNA synthesis and arresting the carcinoma cell cycle from G1 to S phase These effects may inhibit not only tumor growth of the primary carcinoma, but also the establishment of metastases at ectopic tissues Laminin glycopeptides could also inhibit the secretion of matrix metalloproteinases from carcinoma cells and this may contribute to their decreased invasive and metastatic phenotype This study further revealed the cellular and molecular mechanism of laminin glycopeptides on anti metastasis