Efficacy and safety of intraperitoneally administered resveratrol against rat orthotopic ovarian cancers.

BACKGROUND: Resveratrol (Res) inhibits ovarian cancer (OC) cell growth but its in vivo anti-OC effects are unclear due to the low bioavailability of systemically administered Res. Intraperitoneal administration may overcome this therapeutic dilemma because it makes Res directly affect the abdominal tumors. Ethanol and DMSO are common Res solvents, while their reliability and safety for long-term in vivo treatment remain unknown. METHODS: A rat orthotopic OC model was established using the rat NUTU-19 OC cell line. Res dissolved in 10% ethanol or 0.2% DMSO was injected intraperitoneally (20 mg/kg/day) into tumor-free and tumor-bearing rats for 2 weeks. The tumors were collected for gross, morphological and molecular examinations, and blood and ascitic samples were obtained for a CA125 ELISA. Res concentration in ovarian tissues was determined by high performance liquid chromatography (HPLC). RESULTS: The average tumor weight (0.187±0.065 g) of the Res-in-DMSO group was lower than that of untreated (0.426±0.091 g; P<0.01) and Res-in-ethanol (0.238±0.073 g; P<0.05) group. The average bloody ascitic volumes collected from untreated, Res-in-ethanol, and Res-in-DMSO groups were 5.65±0.27, 2.75±0.14, and 2.09±0.11 ml, respectively. Abundant TUNEL-positive cells, ARHI and PIAS3 upregulation, CA125 reduction, and decreased STAT3 nuclear translocation were found in the Res-in-ethanol and, especially, the Res-in-DMSO group. Widespread plaques of Res deposits were found on the abdominal serosa of the Res-in-ethanol group, but not in the Res-in-DMSO group. HPLC revealed a higher Res concentration in Res-in-DMSO-treated tumor tissues than in those treated by Res-in-ethanol (P<0.01). Fertility was maintained after long-term Res treatment. CONCLUSION: Intraperitoneal administration of Res effectively inhibited rat orthotopic ovarian cancer growth without affecting normal tissues. The Res-in-DMSO group had the highest drug bioavailability and therefore stronger tumor-suppressive effects on ovarian cancer tissues.

Correlation of ARHI upregulation with growth suppression and STAT3 inactivation in resveratrol-treated ovarian cancer cells.

BACKGROUND: Aplysia ras homology member I/ARHI is known as ovarian cancer suppressor gene and potential inhibitor of signal transducer and activator of transcription 3/STAT3 signaling. Resveratrol suppresses growth and STAT3 activation of ovarian cancer cells, while its influence in ARHI expression remains unknown. OBJECTIVE: The current study aims to elucidate the status of ARHI expression and its relevance with growth suppression and STAT3 inactivation of resveratrol-treated cells. METHODS: ARHI expression patterns of three ovarian cancer cell lines (human CAOV-3, OVCAR-3 and rat NUTU-19) without and with 100 µM resveratrol treatment were checked by immunocytochemical staining, Western blotting and RT-PCR. The involvement of ARHI in the growth inhibition and STAT3 inactivation of resveratrol-treated OVCAR-3 cells was investigated by transfection of ARHI-specific siRNA. RESULTS: ARHI is expressed in low levels in three ovarian cancer cell lines, which is upregulated upon resveratrol treatment accompanied with growth arrest, extensive apoptosis, increased autophagic activity and inactivated STAT3 signaling. Specific siRNA transfection efficiently knocked down ARHI expression in resveratrol-treated CAOV-3 and OVCAR-3 cells and increased the total cell number in limited extents (P> 0.05) in comparison with that of resveratrol-treated ovarian cancer cells without any transfection or transfected with mock oligonucleotides. ARHI knockdown failed to prevent resveratrol-caused STAT3 inactivation and cell crisis. CONCLUSION: ARHI upregulation is another molecular event caused by resveratrol and one of the elements related with resveratrol's anti-ovarian cancer efficacy. Resveratrol may inactivate STAT3 signaling of ovarian cancer cells in ARHI unrelated pattern(s).

Upregulation of BAG3 with apoptotic and autophagic activities in maggot extract­promoted rat skin wound healing.

Maggot extract (ME) accelerates rat skin wound healing, however its effect on cell maintenance in wound tissues remains unclear. B­cell lymphoma (Bcl) 2­associated athanogene (BAG)3 inhibits apoptosis and promotes autophagy by associating with Bcl­2 or Beclin 1. Bcl­2, the downstream effector of signal transducer and activator of transcription 3 signaling, is enhanced in ME­treated wound tissues, which may reinforce the Bcl­2 anti­apoptotic activity and/or cooperate with Beclin 1 to regulate autophagy during wound healing. The present study investigated expression levels of BAG3, Bcl­2, Beclin 1 and light chain (LC)3 levels in rat skin wound tissues in the presence and absence of ME treatment. The results revealed frequent TUNEL­negative cell death in the wound tissues in the early three days following injury, irrespective to ME treatment. TUNEL­positive cells appeared in the wound tissues following 4 days of injury and 150 µg/ml ME efficiently reduced apoptotic rate and enhanced BAG3 and Bcl­2 expression. Elevated Beclin 1 and LC3 levels and an increased LC3 II ratio were revealed in the ME­treated tissues during the wound healing. The results of the present study demonstrate the anti­apoptotic effects of BAG3 and Bcl­2 in ME­promoted wound healing. Beclin 1/LC3 mediated autophagy may be favorable in maintaining cell survival in the damaged tissues and ME­upregulated BAG3 may enhance its activity.

PIAS3, SHP2 and SOCS3 Expression patterns in Cervical Cancers: Relevance with activation and resveratrol-caused inactivation of STAT3 signaling.

OBJECTIVE: Resveratrol inhibits cervical cancer (CC) cells by blocking STAT3 signaling. However, the mechanism of resveratrol-induced STAT3 inactivation remains largely unknown. SHP2, PIAS3, and SOCS3 are STAT3 negative regulators; therefore, their statuses in cervical adenocarcinoma (HeLa) and squamous cell carcinoma (SiHa and C33A) cell lines without and with resveratrol treatment and their correlation with STAT3 activation in CC specimens were investigated. METHODS: MTT and TUNEL assays were used to check the resveratrol sensitivity of CC cells, and immunocytochemical staining, Western blotting, and RT-PCR were used to analyze SHP2, PIAS3, and SOCS3 expression and the intracellular distribution of STAT3. Tissue microarray based immunohistochemical staining was performed to investigate potential correlations between SHP2, PIAS3, and SOCS3 expression and STAT3 activation. RESULTS: PIAS3 and SOCS3 were found to be weakly expressed in CC cells and upregulated by resveratrol; this was accompanied by inhibition of STAT3 signaling. The SHP2 level remained unchanged in all three cell lines after resveratrol treatment. STAT3 nuclear translocation was more frequent in adenocarcinomas and squamous cell carcinomas than that of their noncancerous counterparts. The SOCS3 level and detection rate were higher in noncancerous squamous cells (but not in glandular epithelia) compared with their cancerous counterparts. The phospho-SHP2 detection rate was similar in noncancerous and tumor tissues of squamous and glandular origins; however, PIAS3 levels were distinct. CONCLUSIONS: Of the three STAT3 negative regulators, PIAS3 correlated most negatively with STAT3 nuclear translocation and may inhibit STAT3 signaling in both histological CC subtypes. PIAS3 responsiveness may reflect greater resveratrol sensitivity and improved therapeutic outcome in CCs.

Inhibition of STAT3 signaling as critical molecular event in resveratrol-suppressed ovarian cancer cells.

BACKGROUND: Resveratrol exerts inhibitory effects on ovarian cancer cells, while its underlying mechanism and critical molecular target(s) have been lesser known. Activations of Wnt, Notch and STAT3 signaling are frequent in ovarian cancers/OCs and supposed to be important for OC formation and progression, while the impacts of resveratrol on these signaling pathways in OC cells remain obscure. METHODS: In this study, two human ovarian cancer cell lines, OVCAR-3 and CAOV-3, were treated by 120 µM resveratrol and their responses to the treatment and the statuses of Wnt, Notch and STAT3 signaling in them were analyzed by multiple experimental approaches. Selective inhibitors of Wnt, Notch or STAT3 signaling were employed to treat OVCAR-3 and CAOV-3 cells to elucidate the significance of individual signaling pathways for ovarian cancers. RESULTS: The results demonstrated distinct inhibitory effects of resveratrol on human ovarian cancer cells in terms of remarkable G1 phase accumulation, increased apoptosis fraction and concurrent suppression of Wnt, Notch and STAT3 signaling as well as their downstream cancer-related gene expression. Treatments with Wnt, Notch or STAT3 selective inhibitor revealed that only AG490, a JAK-specific inhibitor, inhibits OVCAR-3 and CAOV-3 cells in the extent as similar as that of resveratrol. CONCLUSION: Our results suggest the significance of STAT3 activation in the maintenance and survival of ovarian cancer cells. The activated STAT3 signaling is the critical molecular target of resveratrol. Resveratrol would be a promising candidate in the management of ovarian cancers, especially the ones with resistance to conventional therapeutic agents.

Molecular events underlying maggot extract promoted rat in vivo and human in vitro skin wound healing.

Maggot extracts promote wound healing, but their bioactive part(s) and molecular effects on the regenerating tissues/cells remain largely unclear. These issues are addressed here by treating rat skin wounds, human keratinocyte line/HaCat and fibroblasts with maggot secretion/excretion, and the extracts of maggots without and with secretion/excretion. The wound closure rates, cell proliferation activities, and statuses of wound healing-related signaling pathways (STAT3, Notch1, Wnt2, NF-κB, and TGF-beta/Smad3) and their downstream gene expression (c-Myc, cyclin D1, and VEGF) are evaluated by multiple approaches. The results reveal that the maggot extracts, especially the one from the maggots without secretion/excretion, show the best wound healing-promoting effects in terms of quicker wound closure rates and more rapid growth of keratinocytes and fibroblasts. Of the five signaling pathways checked, the ones mediated by TGF-beta/Smad3, and STAT3 are activated in the untreated wounds and become further enhanced by the maggot extracts, accompanied with c-Myc, VEGF, and cyclin D1 up-regulation. Our results thus show (1) that both body extract and secretion/excretion of maggots contain favorable wound healing elements and (2) that the enhancement of TGF-beta/Smad3 and STAT3 signaling activities may be the main molecular effects of maggot extracts on the wound tissues.