Danshen improves survival of patients with advanced lung cancer and targeting the relationship between macrophages and lung cancer cells.

In traditional Chinese medicine, Salvia miltiorrhiza Bunge (danshen) is widely used in the treatment of numerous cancers. However, its clinical effort and mechanism in the treatment of advanced lung cancer are unclear. In our study, the in vivo protective effort of danshen in patients with advanced lung cancer were validated using data from the National Health Insurance Research Database in Taiwan. We observed in vitro that dihydroisotanshinone I (DT), a bioactive compound in danshen, exerts anticancer effects through many pathways. First, 10 µM DT substantially inhibited the migration ability of lung cancer cells in both macrophage and macrophage/lung cancer direct mixed coculture media. Second, 10 µM DT repressed the phosphorylation of signal transducer and activator of transcription 3 (STAT3), the protein expression of S-phase kinase associated protein-2 (Skp2), and the mRNA levels of STAT3-related genes, including chemokine (C-C motif) ligand 2 (CCL2). In addition, 10 µM DT suppressed the macrophage recruitment ability of lung cancer cells by reducing CCL2 secretion from both macrophages and lung cancer cells. Third, 20 µM DT induced apoptosis in lung cancer cells. Furthermore, DT treatment significantly inhibited the final tumor volume in a xenograft nude mouse model. In conclusion, danshen exerts protective efforts in patients with advanced lung cancer. These effects can be attributed to DT-mediated interruption of the cross talk between lung cancer cells and macrophages and blocking of lung cancer cell proliferation.

Anti-cancer effect of danshen and dihydroisotanshinone I on prostate cancer: targeting the crosstalk between macrophages and cancer cells via inhibition of the STAT3/CCL2 signaling pathway.

Danshen (Salvia miltiorrhiza Bunge) is widely used in traditional Chinese medicine. In our study, the in vivo protective effect of danshen in prostate cancer patients was validated through data from the National Health Insurance Research Database in Taiwan. In vitro, we discovered that dihydroisotanshinone I (DT), a bioactive compound present in danshen, can inhibit the migration of both androgen-dependent and androgen-independent prostate cancer cells. In addition, we noted that DT substantially inhibited the migratory ability of prostate cancer cells in both a macrophage-conditioned medium and macrophage/prostate cancer coculture medium. Mechanistically, DT both diminished the ability of prostate cancer cells to recruit macrophages and reduced the secretion of chemokine (C-C motif) ligand 2 (CCL2) from both macrophages and prostate cancer cells in a dose-dependent manner. Moreover, DT inhibited the protein expression of p-STAT3 and decreased the translocation of STAT3 into nuclear chromatin. DT also suppressed the expression of tumor epithelial-mesenchymal transition genes, including RhoA and SNAI1. In conclusion, danshen can prolong the survival rate of prostate cancer patients in Taiwan. Furthermore, DT can inhibit the migration of prostate cancer cells by interrupting the crosstalk between prostate cancer cells and macrophages via the inhibition of the CCL2/STAT3 axis. These results may provide the basis for a new therapeutic approach toward the treatment of prostate cancer progression.

Over-expression of SR-cyclophilin, an interaction partner of nuclear pinin, releases SR family splicing factors from nuclear speckles.

Pre-mRNA splicing takes place within a dynamic ribonucleoprotein particle called the spliceosome and occurs in an ordered pathway. Although it is known that spliceosome consists of five small nuclear RNAs and at least 50 proteins, little is known about how the interaction among the proteins changes during splicing. Here we identify that SR-cyp, a Moca family of nuclear cyclophilin, interacts and colocalizes with nuclear pinin (pnn), a SR-related protein involving in pre-mRNA splicing. Nuclear pnn interacts with SR-cyp via its C-terminal RS domain. Upon SR-cyp over-expression, however, the subnuclear distribution of nuclear pnn is altered, resulting in its redistribution from nuclear speckles to a diffuse nucleoplasmic form. The diffuse subnuclear distribution of nuclear pnn is not due to epitope masking, accelerated protein turnover or post-translational modification. Furthermore, we find that SR-cyp regulates the subnuclear distribution of other SR family proteins, including SC35 and SRm300, in a similar manner as it does on nuclear pnn. This result is significant because it suggests that SR-cyp plays a general role in modulating the distribution pattern of SR-like and SR proteins, similar to that of Clk (cdc2-like kinase)/STY on SR family splicing factors. SR-cyp might direct its effect via either alteration of protein folding/conformation or of protein-protein interaction and thus may add another control level of regulation of SR family proteins and modification of their functions.

Molecular characterization of a novel nucleolar protein, pNO40.

We report the discovery and characterization of a novel nucleolar protein. This protein, referred to as pNO40 based on its molecular weight on SDS-PAGE, was identified through yeast two hybrid interaction screen of a human kidney cDNA library using pinin (pnn) protein as the bait. The deduced amino acids of pNO40 derived from cDNA cloning of diverse species display high conservation; 95% identify between human and mouse and 57.3% identity for human and zebrafish. Several distinct domains are discernable in the ORF of pNO40, including a ribosomal protein S1 RNA binding region, a CCHC type zinc finger, and clusters of basic amino acid representing potential nucleolar targeting signal. Immunostaining of endogenous or transfected pNO40 indicated that it is localized to nucleoli of diverse cultured cells, with some concentration in the granular component of nucleoli. Northern blot analysis demonstrated that pNO40 message is expressed ubiquitously across all tissues examined. Characterization of human and mouse pNO40 gene revealed that mouse gene spans 44 kb in length and contains 8 exons, while that of human is 68 kb in length and displays two isoforms generated by alternative splicing of the 5(')-untranslated region and differential usage of translation start site. Based on sequence features and its subcellular location, we predict that pNO40 is a novel nucleolar protein with function related to ribosome maturation and/or biogenesis.