dorsomorphin and Ovarian-Neoplasms

Members of the transforming growth factor-β (TGF-β) superfamily transduce signals via SMAD proteins. SMAD2 and SMAD3 mediate TGF-β signaling, whereas SMAD1, SMAD5, and SMAD8/9 transduce bone morphogenetic protein (BMP) signals. We would like to identify the function of BMP/SMAD5 signaling in serous ovarian cancer. The protein levels of total SMAD5 and phosphorylated SMAD5 (pSMAD5) were examined by immunohistochemical analysis using clinical serous ovarian cancer samples. Following treatment with either recombinant BMP2 (rBMP2) or Dorsomorphin (DM), western blotting was performed to observe pSMAD5 protein in the cytoplasm and the nucleus, separately. Cell proliferation was detected in SMAD5 knockdown serous ovarian cancer cell lines cultured with DM or rBMP2. The impact of DM or rBMP2 on tumor growth was observed in a mouse model of serous ovarian cancer. An inverse correlation was observed between pSMAD5 levels in the nucleus and the prognosis of patients with serous ovarian cancer. The treatment of SK-OV-3 with rBMP2 stimulated pSMAD5 translocation from the cytoplasm to the nucleus, and the addition of DM inhibited this effect. The proliferation of ovarian cancer cell lines was enhanced by BMP2 and suppressed by DM via SMAD5 in vitro. In vitro and in vivo experiments clearly demonstrated BMP2-stimulated proliferation of serous ovarian cancer and inhibition of this effect by DM. Our data suggests that BMP/SMAD5 signaling plays an important role and, therefore, becomes a potential therapeutic target in serous ovarian cancer. © 2015 Wiley Periodicals, Inc.

Topics: Animals; Bone Morphogenetic Protein 2; Bone Morphogenetic Proteins; Cell Proliferation; Female; Humans; Mice; Ovarian Neoplasms; Ovary; Phosphorylation; Prognosis; Protein Kinase Inhibitors; Pyrazoles; Pyrimidines; Recombinant Proteins; Signal Transduction; Smad5 Protein; Transforming Growth Factor beta

Inherent or acquired drug resistance is a major contributor to epithelial ovarian cancer (EOC) mortality. Novel drugs or drug combinations that produce EOC cell death or resensitize drug resistant cells to standard chemotherapy may improve patient treatment. After conducting drug tolerability studies for the multikinase inhibitors dorsomorphin (DM) and it is structural analogue LDN-193189 (LDN), these drugs were tested in a mouse intraperitoneal xenograft model of EOC. DM significantly increased survival, whereas LDN showed a trend toward increased survival. In vitro experiments using cisplatin (CP)-resistant EOC cell lines, A2780-cp or SKOV3, we determined that pretreatment or cotreatment with DM or LDN resensitized cells to the killing effect of CP or carboplatin (CB). DM was capable of blocking EOC cell cycle and migration, whereas LDN produced a less pronounced effect on cell cycle and no effect on migration. Subsequent analyses using primary human EOC cell samples or additional established EOC cells lines showed that DM or LDN induced a dose-dependent autophagic or cell death response, respectively. DM induced a characteristic morphological change with the appearance of numerous LC3B-containing acidic vacuoles and an increase in LC3BII levels. This was coincident with a decrease in cell growth and the altered cell cycle consistent with DM-induced cytostasis. By contrast, LDN produced a caspase 3-independent, reactive oxygen species-dependent cell death. Overall, DM and LDN possess drug characteristics suitable for adjuvant agents used to treat chemotherapy-sensitive and -resistant EOC.

Topics: Adenocarcinoma; AMP-Activated Protein Kinases; Animals; Apoptosis; Blotting, Western; Carcinoma, Ovarian Epithelial; Cell Cycle; Cell Proliferation; Cystadenocarcinoma, Serous; Drug Resistance, Neoplasm; Female; Humans; Immunoenzyme Techniques; Mice; Neoplasm Grading; Neoplasms, Glandular and Epithelial; Ovarian Neoplasms; Pyrazoles; Pyrimidines; Tumor Cells, Cultured; Wound Healing; Xenograft Model Antitumor Assays

Metformin, a commonly used drug in the treatment of type II diabetes, may reduce cancer risk and improve cancer prognosis. We evaluated its effect on epithelial ovarian cancer cell lines.. The OVCAR-3 and OVCAR-4 cell lines were exposed to metformin with and without cisplatin. Cytotoxicity assays were performed in triplicates using the Alamar colorimetric assay. Levels of total and phosphorylated AMPK, p70S6K and S6K were evaluated by Western blotting following exposure to metformin.. Metformin induces dose- and time-dependent growth inhibition of OVCAR-3 and OVCAR-4 cell lines. Metformin potentiated the effect of cisplatin in vitro. Metformin growth inhibition was partly abolished by the AMPK inhibitor, compound C. Western blotting demonstrated that metformin at cytotoxic concentrations, induced AMPK phosphorylation and decreased p70S6K and S6K phosphorylation, suggesting the mechanism for its anti-proliferative action.. Metformin significantly inhibits the growth of ovarian cancer cell lines and potentiates cisplatin. Further pre-clinical studies are being conducted to determine the applicability of metformin in the treatment of ovarian cancer.

Topics: Adenylate Kinase; Antineoplastic Combined Chemotherapy Protocols; Blotting, Western; Cell Growth Processes; Cell Line, Tumor; Cisplatin; Dose-Response Relationship, Drug; Drug Screening Assays, Antitumor; Drug Synergism; Female; Humans; Metformin; Ovarian Neoplasms; Phosphorylation; Pyrazoles; Pyrimidines; Ribosomal Protein S6 Kinases; Ribosomal Protein S6 Kinases, 70-kDa