Organ Preference Of Metastasis Research Articles

Organ Preference of Cancer Metastasis and Metastasis-Related Cell Adhesion Molecules Including Carbohydrates.

This review starts on one of our special interests, the organ preference of metastasis. We examined data on 1,117 autopsy cases and found that the organ distribution of metastasis of cancers of the lung, pancreas, stomach, colon, rectum, uterine cervix, liver, bile duct, and esophagus involved the lung, liver, adrenal gland, bone/bone marrow, lymph node, and pleura/peritoneum. Cancers of the kidney, thyroid, ovary, choriocarcinoma, and breast, however, manifested different metastatic patterns. The distribution of leukemia and lymphoma metastases was quite different from that of epithelial cancers. On the basis of experimental studies, we believe that the anatomical-mechanical hypothesis should be replaced by the microinjury hypothesis, which suggests that tissue microinjury induced by temporal tumor cell embolization is crucial for successful metastasis. This hypothesis may actually reflect the so-called inflammatory oncotaxis concept. To clarify the mechanisms underlying metastasis, we developed an experimental model system of a rat hepatoma AH7974 that embraced substrate adhesiveness. This model did not prove a relationship between substrate-adhesion potential and metastatic lung-colonizing potential of tumor cells, but metastatic potential was correlated with the expression of the laminin carbohydrate that was recognized by Griffonia (Bandeiraea) simplicifolia isolectin G4. Therefore, we investigated the relationship between carbohydrate expression profiles and metastasis and prognosis. We indeed found an intimate relationship between the carbohydrate expression of cancer cells and the progression of malignant tumors, organ preference of metastasis, metastatic potential of tumor cells, and prognosis of patients.

Clinical Implications of Microsomal Prostaglandin E Synthase-1 Overexpression in Human Non–Small-Cell Lung Cancer

Microsomal prostaglandin E synthase-1 (mPGES-1) has recently been found to overexpress in human cancers, including non-small-cell lung cancer (NSCLC). However, the clinical value is largely unknown. The aim of this study was to investigate the associations between mPGES-1 expression in NSCLC and the clinical characteristics and survival outcome. Between 2001 and 2003, paired fresh tumorous and nontumorous samples were prospectively procured from patients undergoing surgery for NSCLC. The expression of mPGES-1 was assessed by using Western blot in 93 subjects and reverse transcriptase-polymerase chain reaction in 35. Overexpression of mPGES-1 was defined as a more than 2-fold expression in the tumorous sample compared with the corresponding nontumorous one. Immunohistochemistry was used to confirm its localization to the tumor cells. In a subset of 30 cases, cyclooxygenase-2 (COX-2) was also analyzed to assess its association with mPGES-1. The protein and messenger RNA of mPGES-1 were both expressed at higher levels in the tumor samples (P < .001 and P = .006, respectively). The expressions of mPGES-1 and COX-2 were unrelated (P = .715). Overexpression of mPGES-1 protein was observed in 61 (65.6%) of 93 patients, but it was not significantly associated with the clinicopathologic characteristics or overall and disease-free survivals. However, mPGES-1 overexpression seemed to be associated with the likelihood of subsequent pulmonary metastases and a lower tendency for developing bony metastases (P = .001 and P = .006, respectively). Our results demonstrated that mPGES-1 was overexpressed in NSCLC, unassociated with COX-2. Overexpression of mPGES-1 per se was not a prognostic indicator, but it might be implicated in the organ preference of metastasis.

Endothelial Cell Adhesion Molecules and Their Role in Organ Preference of Metastasis.

Endothelial cell adhesion molecules expressed in distinct vascular branches of select organs are implicated in organ preference of metastasis. Two constitutively expressed adhesion molecules of the lung vasculature are described here. The first is the murine B 16 melanoma cell-binding endothelial cell adhesion molecule Lu-ECAM-1. The 90kDa Lu-ECAM-1 selectively promotes adhesion and lung metastasis of B 16 melanoma cells. Melanoma cell attachment to immobilized Lu-ECAM-1 is inhibited in a dose dependant manner by anti-Lu-ECAM-1 mAb 6D3, soluble Lu-ECAM-1, and lacto-N-fucopentose. In vivo blocking of Lu-ECAM-1 by its mAb 6D3 prevents lung colonization of B16-F10. However, Lu-ECAM-1 either binds nor affects metastasis of other lung colonizing tumor cells (e.g., KLN205 carcinoma cells), or tumor cell lines that metastasize to other organs than the lung (e.g., liver-metastatic B16-L8-F10, RAW117-H10), and does not bind lymphocytes and neutrophils. The second adhesion molecule is rat dipeptidyl peptidase IV(DPP IV). This sialoglycoprotein binds lung-metastatic rat prostate and breast carcinoma cells via fibronectin which is expressed in significantly higher amounts on the surface of metastatic than non-metastatic tumor cells. Increased fibronectin expression is associated with increases in tumor cell β1 and β3 integrins. DPP IV binding is mediated by a fibronectin sequence other than RGD and is independent of its peptidase domain. These constitutively expressed adhesion molecules are believed to be responsible for site-specific vascular arrest of blood-borne cancer cells and, through as yet unknown signaling events, may cause upregulation of other (transiently expressed) adhesion molecules to enhance tumor cell binding to endothelium and/or initiate gap junctional communication to promote extravasation and secondary tumor growth.