Human lung cancer-derived microparticles enhanced angiogenesis and growth of hepatoma cells in rodent lung parenchyma.

This study tested the hypothesis that human lung cancer-derived microparticles (LcD-MPs) played an important role in tumor angiogenesis and growth. Fischer 344 rats (F344, n=18) were equally categorized into group 1 [Sham Control (3.0 mL normal saline intravenous injection (IV))], group 2 [hepatoma cell line (2.0 x 10(6) cells, IV)], and group 3 [hepatoma cell line + LcD-MPs (3.0 x 10(6), IV)]. Animals were euthanized by day 28 after hepatoma cells transfusion. Our result showed that the gross pathology confirmed growth of hepatoma cell line in lung parenchyma. The size and weight of the lungs were significantly increased in group 2 and further elevated in group 3 than in group 1 (all p<0.001). Histopathological analysis demonstrated that the lung crowded score and number of small vessel exhibited an identical pattern, whereas the number of alveolar sacs showed an opposite pattern compared to that of total lung weight among the three groups (all p<0.0001). The cellular expressions of CD34(+), CXCR4(+), c-Kit(+), CK19(+), VEGF(+) and vimentin+ cells in lung parenchyma exhibited an identical pattern compared to those of total lung weight among all groups (all p<0.001). The protein expressions of apoptotic (Bax, cleaved caspase-3 and c-PARP), fibrotic (Smad3, TGF-β), and tumor suppression (PTEN) biomarkers showed an identical pattern, whereas that of anti-apoptotic (Bcl-2) and anti-fibrotic (Smad1/5, BMP-2) biomarkers were displayed an opposite pattern compared to that of total lung weight among all groups (all p<0.001). The MPs could enhance angiogenesis and accelerated hepatoma cell growth in rodent lung parenchyma.