Postoperative resveratrol administration improves prognosis of rat orthotopic glioblastomas.

BACKGROUND: Although our previous study revealed lumbar punctured resveratrol could remarkably prolong the survival of rats bearing orthotopic glioblastomas, it also suggested the administration did not completely suppress rapid tumour growth. These evidences led us to consider that the prognosis of tumour-bearing rats may be further improved if this treatment is used in combination with neurosurgery. Therefore, we investigated the effectiveness of the combined treatment on rat orthotopic glioblastomas. METHODS: Rat RG2 glioblastoma cells were inoculated into the brains of 36 rats. The rats were subjected to partial tumour removal after they showed symptoms of intracranial hypertension. There were 28 rats that survived the surgery, and these animals were randomly and equally divided into the control group without postoperative treatment and the LP group treated with 100 µl of 300 µM resveratrol via the LP route. Resveratrol was administered 24 h after tumour resection in 3-day intervals, and the animals received 7 treatments. The intracranial tumour sizes, average life span, cell apoptosis and STAT3 signalling were evaluated by multiple experimental approaches in the tumour tissues harvested from both groups. RESULTS: The results showed that 5 of the 14 (35.7%) rats in the LP group remained alive over 60 days without any sign of recurrence. The remaining nine animals had a longer mean postoperative survival time (11.0 ± 2.9 days) than that of the (7.3 + 1.3 days; p < 0.05) control group. The resveratrol-treated tumour tissues showed less Ki67 labelling, widely distributed apoptotic regions, upregulated PIAS3 expression and reduced p-STAT3 nuclear translocation. CONCLUSIONS: This study demonstrates that postoperative resveratrol administration efficiently improves the prognosis of rat advanced orthotopic glioblastoma via inhibition of growth, induction of apoptosis and inactivation of STAT3 signalling. Therefore, this therapeutic approach could be of potential practical value in the management of glioblastomas.

Correlation of Reactive Oxygen Species Levels with Resveratrol Sensitivities of Anaplastic Thyroid Cancer Cells.

Anaplastic thyroid carcinoma (ATC) is the most lethal thyroid malignancy without a reliable therapeutic agent. Resveratrol possesses cancer-suppressive effects, while its effect(s) on ATC cells remains unknown. Because oxidative damage caused by increased reactive oxygen species (ROS) is one of the therapeutic effects of anticancer drugs and oxidative stress-caused mitochondria swelling is observed in resveratrol-treated cancer cells, the oxidative statuses and their relevance with resveratrol sensitivities are elucidated using THJ-16T and THJ-11T ATC cells established from two human anaplastic thyroid carcinoma cases. The results revealed that resveratrol-treated THJ-16T rather than THJ-11T cells showed remarkable growth arrest and extensive apoptosis accompanied with the elevated ROS generation and the attenuated superoxide dismutase 2 (SOD2) and catalase (CAT) levels. Mitochondrial impairment and the enhanced caspase-9/caspase-3 activation are found only in resveratrol-sensitive THJ-16T cells. Treatment with the antioxidant N-acetylcysteine (NAC) partly attenuated resveratrol-induced ROS generation and apoptosis of THJ-16T cells. The levels of resveratrol metabolic enzymes (SULT1A1 and SULT1C2) in THJ-16T cells were lower than those in THJ-11T cells and therefore reversely related with resveratrol sensitivities of ATC cells. Our findings demonstrate the ability of resveratrol to increase ROS generation and oxidative-related cellular lesions in resveratrol-sensitive THJ-16T cells presumably through activating the ROS-mitochondrial signal pathway. The levels of SULTs and ROS may reflect the response manners of ATC cells to resveratrol.

Resveratrol Suppresses the Growth and Enhances Retinoic Acid Sensitivity of Anaplastic Thyroid Cancer Cells.

Anaplastic thyroid cancer (ATC) is a highly lethal undifferentiated malignancy without reliable therapies. Retinoic acid (RA) has been employed to promote redifferentiation of thyroid cancers by increasing their I131 uptake and radio-sensitivity, but its effect(s) on ATCs has not yet been ascertained. Likewise, resveratrol induces cancer redifferentiation but, also in this case, its effects on ATCs remain unknown. These issues have been addresses in the current study using three human ATC cell lines (THJ-11T, THJ-16T, and THJ-21T) through multiple experimental approaches. The results reveal that RA exerts a small inhibitory effect on these cell lines. In comparison with normally cultured cells, the total cell number in resveratrol-treated THJ-16T and THJ-21T cultures significantly decreased (p < 0.05), and this effect was accompanied by reduced Cyclin D1 immuno-labeling, increased apoptotic fractions, and distinct caspase-3 activation. Resveratrol failed to inhibit growth but enhanced RA sensitivity of THJ-11T cells, suppressed peroxisome proliferator-activated receptor-ß/δ (PPAR-ß/δ), and upregulated cellular retinoic acid-binding protein 2 (CRABP2) and retinoic acid receptor beta (RAR-ß) expression. Increased thyroglobulin (Tg) and E-cadherin levels and appearance of membranous E-cadherin were evidenced in resveratrol-treated THJ-11T cells. Our results demonstrate for the first time: (1) the therapeutic value of resveratrol by itself or in combination with RA in the management of ATCs, (2) the capacity of resveratrol to overcome RA resistance in ATC cells by reprogramming CRABP2/RAR- and fatty acid-binding protein 5 (FABP5)/PPAR-ß/δ-mediated RA signaling, and (3) the redifferentiating potential of resveratrol in ATC cells.

Preventive Potential of Resveratrol in Carcinogen-Induced Rat Thyroid Tumorigenesis.

Thyroid cancer (TC) is the most common endocrine malignancy without reliable preventive agent. Resveratrol possesses in vitro anti-TC activities; while its effect(s) on thyroid tumorigenesis remains unknown. This study aims to address this issue using DEN/MNU/DHPN-induced rat carcinogenesis model. 50 male Sprague-Dawley rats were separated into four groups as Group-1 (5 rats); normally fed; Group-2 (15 rats); DEN/MNU/DHPN treatment only; Group-3 (15 rats) and -4 (15 rats); DEN/MNU/DHPN treatment; followed by resveratrol intragastric (IG) injection and intraperitoneal (IP) injection; respectively; in two-day intervals for 30 weeks. The results revealed that the average resveratrol concentration in thyroid tissues was 1.278 ± 0.419 nmol/g in IG group and 1.752 ± 0.398 nmol/g in IP group. The final body weights of Group-3 and Group-4 were lighter than that (p > 0.05) of Group-1; but heavier than Group-2 (p < 0.05). TC-related lesions (hyperplasia and adenomas) were found in 53.3% of Group-2; 33.3% Group-3 and 26.7% Group-4. Lower serum carcino-embryonic antigen (CEA) and thyroglobulin (Tg) levels; down-regulated expression of IL-6 and cyclooxygenase-2 (COX-2); reduction of NF-κB/p65 nuclear translocation; and elevated IkBα expression were found in the thyroid tissues of Group-3 and Group-4 in comparison with that of Group-2. These results demonstrate that IG and IP administered resveratrol efficiently reduces the frequency and severity of DEN/MNU/DHPN-caused TC-related lesions and would be of values in thyroid tumor prevention.

Inversed Expression Patterns of S100A4 and E-Cadherin in Cervical Cancers: Implication in Epithelial-Mesenchymal Transition.

Cervical cancer/CC is the third commonest female malignancy worldwide. The aggressive growth and distal metastases are the leading causes of CC mortality, which is largely due to epithelial-mesenchymal transition/EMT. Fibroblast specific protein S100A4 promotes cancer metastasis and epithelial type cadherin/E-cadherin play pivotal roles in cell-cell and cell-extracellular matrix interaction. Therefore, the expression patterns of S100A4 and E-cadherin reflect statuses of EMT of carcinoma cells. However, S100A4 expression and its relevance with E-cadherin and HPV16 infection in cervical cancers remain unknown. This study aims to address the above issues using cervical cancer specimens. Immunohistochemistry reveals that the levels of mesenchymal marker S100A4 is upregulated (>++) in cervical adenocarcinomas/CACs (12/16; 75%) and squamous cell carcinomas/CSCCs (23/28; 82%) than that in noncancerous glandular epithelia/GE (0/12; 0%) and squamous epithelia/SE (0/12; 0%). Epithelial marker membranous E-cadherin is remarkably reduced on the surface of CAC and CSCC cells (P = 0.00; P = 0.00), especially those showing poorly differentiated phenotypes (P < 0.05) in comparison with their noncancerous counterparts. Correlative analyses revealed an inverse relationship between S100A4 and E-cadherin expression among the cervical cancer samples (P = 0.01, r = -0.38). S100A4 expression level in HPV16-infected group is higher than that in HPV16-free group (P = 0.02). These results suggest the close correlation of S100A4 upregulation with cervical cancer formation and HPV16 infection and E-cadherin reduction with the grades of CC dedifferentiation. The concurrent gain of S100A4 and loss of membrane E-cadherin suggest EMT tendency of CC cells and can be regarded as an unfavorable prognostic parameter of CC patients. Anat Rec, 300:2184-2191, 2017. © 2017 Wiley Periodicals, Inc.

Correlative analyses of the expression levels of PIAS3, p-SHP2, SOCS1 and SOCS3 with STAT3 activation in human astrocytomas.

The importance of signal transducer and activator of transcription 3 (STAT3) signaling in the growth and survival of glioblastoma cells has been well documented, while the reasons leading to STAT3 activation remains to be elucidated. Suppressors of cytokine signaling (SOCS) 1 and SOCS3, SH2 domain­containing phosphatase (SHP2) and protein inhibitors of activated STAT3 (PIAS3) are known to inhibit STAT3 signal transduction, while their expression statuses in the four grades of astrocytomas and relevance with STAT3 activation remain to be described. The present study aimed to address these issues by tissue microarray­based immunohistochemical profiling the expression levels of phosphorylated (p)­STAT3, SOCS1, SOCS3, PIAS3 and p­SHP2. The results revealed that p­STAT3 nuclear translocation was rarely observed in non­cancerous brain tissues and its frequencies were increased in a tumor grade­associated manner (65.2, 77.1, 81.8 and 85.7% for grade I­IV, respectively). PIAS3, p­SHP2, SOCS1 and SOCS3 were expressed in higher levels (++ and +++) in 63.6, 90, 87.5 and 81.8% of tumor surrounding brain tissues, which reduced to 13.1, 47.8, 33.3 and 50% in grade I, 11.4, 65.7, 58.3 and 77.1% in grade II, 9.1, 63.6, 38.1 and 31.8% in grade III and 7.1, 66.7, 30.8 and 7.1% in grade IV astrocytomas. The above results revealed that although the expression levels of SOCS1, SOCS3 and, in particular, p­SHP2, tend to decrease in the four types of astrocytomas, PIAS3 downregulation is more negatively correlated with STAT3 activation in the stepwise progress of astrocytomas and would indicate an unfavorable outcome.

SHP2, SOCS3 and PIAS3 Expression Patterns in Medulloblastomas: Relevance to STAT3 Activation and Resveratrol-Suppressed STAT3 Signaling.

BACKGROUND: Activated STAT3 signaling is critical for human medulloblastoma cells. SHP2, SOCS3 and PIAS3 are known as the negative regulators of STAT3 signaling, while their relevance to frequent STAT3 activation in medulloblastomas remains unknown. METHODS: Tissue microarrays were constructed with 17 tumor-surrounding noncancerous brain tissues and 61 cases of the classic medulloblastomas, 44 the large-cell medulloblastomas, and 15 nodular medulloblastomas, which were used for immunohistochemical profiling of STAT3, SHP2, SOCS3 and PIAS3 expression patterns and the frequencies of STAT3 nuclear translocation. Three human medulloblastoma cell lines (Daoy, UW228-2 and UW228-3) were cultured with and without 100 µM resveratrol supplementation. The influences of resveratrol in SHP2, SOCS3 and PIAS3 expression and SOCS3 knockdown in STAT3 activation were analyzed using multiple experimental approaches. RESULTS: SHP2, SOCS3 and PIAS3 levels are reduced in medulloblastomas in vivo and in vitro, of which PIAS3 downregulation is more reversely correlated with STAT3 activation. In resveratrol-suppressed medulloblastoma cells with STAT3 downregulation and decreased incidence of STAT3 nuclear translocation, PIAS3 is upregulated, the SHP2 level remains unchanged and SOCS3 is downregulated. SOCS3 proteins are accumulated in the distal ends of axon-like processes of resveratrol-differentiated medulloblastoma cells. Knockdown of SOCS3 expression by siRNA neither influences cell proliferation nor STAT3 activation or resveratrol sensitivity but inhibits resveratrol-induced axon-like process formation. CONCLUSION: Our results suggest that (1) the overall reduction of SHP2, SOCS3 and PIAS3 in medulloblastoma tissues and cell lines; (2) the more inverse relevance of PIAS3 expression with STAT3 activation; (3) the favorable prognostic values of PIAS3 for medulloblastomas and (4) the involvement of SOCS3 in resveratrol-promoted axon regeneration of medulloblastoma cells.

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.

CRABP-II- and FABP5-independent responsiveness of human glioblastoma cells to all-trans retinoic acid.

Glioblastomas respond differently to all-trans retinoic acid (RA) for unknown reasons. Because CRABP-II and FABP5 mediate RA intracellular signaling respectively and lead to distinct biological consequences, their expression patterns in different grades of astrocytomas and the glioblastoma cells lines LN18, LN428 and U251 were examined to identify potential correlations with RA sensitivities. The response of glioblastoma cells to RA, decitabine or the FABP5 competitive inhibitor, BMS309403, was analyzed. CRABP-II and FABP5 were expressed to varying degrees by the 84-astrocytoma cases examined. Treatment of LN428, U251 and LN18 cells with RA failed to suppress their growth; however, U251 proliferation was inhibited by decitabine. The combination of decitabine and RA suppressed the growth of all three cell lines and induced significant apoptosis of LN428 and U251 cells. Both CRABP-II and FABP5 were transcribed in the three cell lines but FABP5 proteins were undetectable in U251 cells. The ratio of CRABP-II to FABP5 was not altered after RA, decitabine or RA and decitabine treatment and the resistance of cells to RA was not reversed by BMS309403 treatment. In conclusion, CRABP-II and FABP5 expression patterns are neither related to the tumor grades nor correlated with RA sensitivity. Additional molecular factors may be present that determines the sensitivity of glioblastoma cells to RA. Dicitabine may improve the sensitivity of glioblastoma cells to RA, however, its underlying mechanism and its in vivo feasibility need to be investigated.

Diffusion Efficiency and Bioavailability of Resveratrol Administered to Rat Brain by Different Routes: Therapeutic Implications.

Resveratrol possesses anti-tumor activities against central nervous system (CNS) tumors in vitro but has not yet been used clinically due to its low bioavailability, particularly in the CNS. This study thus aimed to elucidate brain bioavailability of trans-resveratrol by monitoring brain concentrations and dwell times following administration of resveratrol through intragastric, intraperitoneal, external carotid artery/ECA and intrathecal routes. In parallel, we evaluated the biological responses of rat RG2 glioblastoma cells as well as RG2-formed rat intracranial glioblastomas treated with resveratrol via intrathecal administration. The results revealed that resveratrol was detected in rat brains except when administered systemically. Intrathecal administration of reseveratrol led to abundant apoptotic foci and increased staining of the autophagy proteins, LC-3 and Beclin-1 and shrinkage of the intracranial tumors. In conclusion, the BBB penetrability of resveratrol is remarkably increased by intracthecal administration. Regular short-term resveratrol treatments suppress growth and enhance autophagic and apoptotic activities of rat RG2 glioblastoma cells in vitro and in vivo. Therefore, intrathecal administration of resveratrol could be an optimal intervention approach in the adjuvant management of brain malignancies.

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.

Restoration of S100A4 expression enhances invasive and metastatic potentials of COLO16 cutaneous squamous cancer cells.

BACKGROUND: S100A4 promotes cancer metastasis but is frequently silenced in human cutaneous squamous cell carcinomas/c-SCCs due to DNA methylation, which may explain the less metastasized property of c-SCCs. OBJECTIVE: This study aims to check 1) whether the metastatic potential of S100A4-negative human c-SCC cells could be enhanced when S100A4 expression is restored in COLO16 c-SCC cells with S100A4 methylation and 2) the correlation of S100A4 expression and the differentiation grades and invasiveness of human c-SCC tumors. METHODS: The motility and invasion of parent and transfected COLO16 cells are examined by the use of 24-well modified Boyden chambers, scratched wound healing assay and nude mouse transplantation tumor model. Meanwhile, the correlation of S100A4 expression with growth patterns and grade of differentiation of c-SCC surgical specimens are analyzed. RESULTS: S100A4 expression is successfully restored in COLO16 cells after plasmid lipofectamine transfection. Transwell and scratched wound healing assays shows that the invasion and migration activities of S100A4-expressing transfectants are higher than that of parent COLO16 cells. Subcutaneous and foot pad c-SCC models are established by injecting 5 × 10^{6}/100~l parental and S100A4-expressing COLO16 cells to BALB/c-nu/nude mice, respectively. Histological examination confirms the differences of invasiveness between the parent cells and the transfectants. Regional lymph node metastases are found only in the mice bearing S100A4-expressing tumors. S100A4 expression levels and frequencies are significantly different (P< 0.001) between the well and the poorly differentiated c-SCCs and closely correlated with tumor invasion (P< 0.05). CONCLUSIONS: S100A4 confers invasive and metastatic potentials on human c-SCCs. The low incidence of metastasis of c-SCCs, especially the well differentiated ones, might be due to the infrequent S100A4 expression. S100A4 can be regarded as a negative prognostic biomarker or a metastasis-risk factor of human c-SCCs.

Biological significance and therapeutic implication of resveratrol-inhibited Wnt, Notch and STAT3 signaling in cervical cancer cells.

Cervical cancers/CCs are one of the commonest malignancies and the second leading cause of cancer-related death in women. Resveratrol inhibits CC cell growth but its molecular target(s) remains unclear. Since the signaling pathways mediated by STAT3, Notch1 and Wnt2 play beneficial roles in CC formation and progression, the effects of resveratrol on them in cervical adenocarcinoma (HeLa) and squamous cell carcinoma (SiHa) cells were analyzed. The biological significances of the above signaling for HeLa and SiHa cells were evaluated by treating the cells with STAT3, Wnt or Notch selective inhibitors. The frequencies of STAT3, Notch and Wnt activations in 68 cases of CC specimens and 38 non-cancerous cervical epithelia were examined by tissue microarray-based immunohistochemical staining. The results revealed that HeLa and SiHa cells treated by 100µM resveratrol showed extensive apoptosis, accompanied with suppression of STAT3, Notch and Wnt activations. Growth inhibition and apoptosis were found in HeLa and SiHa populations treated by AG490, a STAT3/JAK3 inhibitor but not the ones treated by Notch inhibitor L-685,458 or by Wnt inhibitor XAV-939. Immunohistochemical staining performed on the tissue microarrays showed that the frequencies of Notch1, Notch2, Hes1, Wnt2, Wnt5a and p-STAT3 detection as well as ß-catenin nuclear translocation in CC samples were significantly higher than that of noncancerous group (p<0.01), while the expression rate of PIAS3 was remarkably low in cancer samples (p<0.01). Our results thus demonstrate that STAT3, Wnt and Notch signaling are frequently co-activated in human CC cells and specimens and resveratrol can concurrently inhibit those signaling activations and meanwhile lead cervical squamous cell carcinoma and adenocarcinoma cells to growth arrest and apoptosis. STAT3 signaling is more critical for CC cells and is the major target of resveratrol because selective inhibition of STAT3 rather than Wnt or Notch activation commits SiHa and HeLa cells to apoptosis.

Short-term resveratrol exposure causes in vitro and in vivo growth inhibition and apoptosis of bladder cancer cells.

Conventional adjuvant chemotherapies for bladder transitional cell carcinomas (TCCs) may cause strong systemic toxicity and local irritation. Non-toxic resveratrol inhibits TCC cell growth but its feasibility in clinical management of TCCs remains obscure. This study aimed to evaluate the safety and anti-TCC efficacy of resveratrol, using the experimental models closer to the clinical treatment condition. Human TCC EJ cells were exposed to 100 µM, 150 µM and 200 µM resveratrol respectively for 1 hour and 2 hours to mimic intravesical drug instillation and the cell responses were analyzed by multiple experimental approaches. An orthotopic TCC nude mouse model was established by injecting EJ cells into the sub-urothelial layer and used for short-term intravesical resveratrol instillation. The safety of resveratrol instillation was evaluated and compared with that of MCC. The results revealed that 2 h 150 µM or 200 µM resveratrol treatment leaded to remarkable S phase arrest and apoptosis at 72 h time-point, accompanied with attenuated phosphorylation, nuclear translocation and transcription of STAT3, down-regulation of STAT3 downstream genes (survivin, cyclinD1, c-Myc and VEGF) and nuclear translocations of Sirt1 and p53. The importance of STAT3 signaling in cell growth was confirmed by treating EJ cells with JAK2 inhibitor tyrphostin AG490. The efficacy and safety of resveratrol instillation were proved by the findings from nude mouse orthotopic xenograft models, because this treatment caused growth suppression, distinctive apoptosis and STAT3 inactivation of the transplanted tumors without affecting normal urothelium. Our results thus suggest for the first time the practical values of resveratrol as a safe and effective agent in the post-operative treatment of TCCs.

Evaluation of resveratrol sensitivities and metabolic patterns in human and rat glioblastoma cells.

PURPOSE: To further elucidate the correlation of resveratrol sensitivities with biotransformation activities of human and rat glioblastoma cells for personalized anti-glioblastoma therapy. METHODS: Resveratrol sensitivity of human U251 and rat RG2 and C6 glioblastoma cells was evaluated by 3-[4,5-dimethylthiazol-2-yl]-2, 5-diphenyltetrazolium bromide/MTT, flow cytometry, and TUNEL assays. The metabolic patterns of those cell lines were analyzed by high-performance liquid chromatography/HPLC coupled with tandem mass spectrum/MS/MS, and high-resolution mass spectrometry/HRMS. Immunocytochemical staining and Western blotting were employed to check resveratrol metabolic enzyme expression. RESULTS: Both rat RG2 and C6 and human U251 glioblastoma cells are sensitive to 100 µM resveratrol in terms of growth arrest and increased apoptotic fraction. The main resveratrol metabolite in U251 cells is monosulfate biotransformed by sulfotransferases/SULTs and in RG2 and C6 cells is monoglucuronide generated by UDP-glucuronosyltransferase/UGT. Both metabolites show lesser therapeutic efficacy. Although brain-associated UGTs (UGT1A6, 2B7, and 8) and SULTs (SULT1A1, 1C2, and 4A1) are expressed in rat and human glioma cells, the overall level of UGTs is predominant in the rat and SULTs in human glioblastoma cells. In similar to SULT expression pattern, UGT1A6, 2B7, and 8 are frequently downregulated (84.6 %, 82/97; 90.7 %, 88/97; 80.4 %, 78/97) in human glioblastoma tissues. CONCLUSION: Our results suggest (1) the decreased resveratrol biotransforming activity in rat and human resveratrol-sensitive glioblastoma cells; (2) the discrepant resveratrol metabolic patterns between human and rat glioblastoma cells; (3) the more powerful anti-glioblastoma efficacy of trans-resveratrol rather than resveratrol monoglucuronide or monosulfate; and (4) the value of RG2 and C6 cells in establishing resveratrol-based rat in vivo therapeutic model.

Expression patterns and potential roles of SIRT1 in human medulloblastoma cells in vivo and in vitro.

Medulloblastoma is a primitive neuroectodermal tumor, which originates in the cerebellum, presumably due to the alterations of some neurogenetic elements. Sirtuin 1 (SIRT1), a class III histone deacetylase (HDAC), regulates differentiation of neuronal stem cells but its status in medulloblastomas remains largely unknown. The current study aimed to address this issue by checking SIRT1 expression in noncancerous cerebellar tissues, medulloblastoma tissues and established cell lines. The roles of SIRT1 in proliferation and survival of UW228-3 medulloblastoma cells were analyzed by SIRT1 small interfering RNA (siRNA) transfection and SIRT1 inhibitor nicotinamide treatment. The results revealed that the frequency of SIRT1 expression in medulloblastoma tissues was 64.17% (77/120), while only one out of seven tumor-surrounding noncancerous cerebellar tissues showed restricted SIRT1 expression in the cells within the granule layer. Of the three morphological subtypes, the rates of SIRT1 detection in the large cell/anaplastic cell (79.07%; 34/43) and the classic medulloblastomas (60.29%; 41/68) are higher than that (22.22%; 2/9) in nodular/desmoplastic medulloblastomas (P<0.01 and P<0.05, respectively). Heterogeneous SIRT1 expression was commonly observed in classic medulloblastoma. Inhibition of SIRT1 expression by siRNA arrested 64.96% of UW228-3 medulloblastoma cells in the gap 1 (G1) phase and induced 14.53% of cells to apoptosis at the 48-h time point. Similarly, inhibition of SIRT1 enzymatic activity with nicotinamide brought about G1 arrest and apoptosis in a dose-related fashion. Our data thus indicate: (i) that SIRT1 may act as a G1-phase promoter and a survival factor in medulloblastoma cells; and (ii) that SIRT1 expression is correlated with the formation and prognosis of human medulloblastomas. In this context, SIRT1 would be a potential therapeutic target of medulloblastomas.

[Detection of differentially expressed lumican gene mRNA level in scleral tissue in human eye].

OBJECTIVE: To identify differentially expressed lumican in scleral tissue of eyes with primary open-angle glaucoma (POAG) and high myopia (HM). METHODS: Total RNA was isolated from scleral tissue of cadaveric eyes derived from normal donors, patient's eyes with diagnosed glaucoma and high myopia who accepted trabeculectomy. RNA was amplified, RT-PCR was used to measure the levels of mRNA. The ratio of the electrophoresis strips'gray scale values of the ß-actin over the lumican gene was obtained for ANOVA analysis. RESULTS: ß-actin/LUM of normal eye was significantly higher than that of POAG and POAG + HM eyes (P < 0.01), but there was no significant difference between POAG and POAG + HM eyes (P > 0.05). CONCLUSIONS: Differentially expressed lumican between POAG and control groups identified in this study have not been previously investigated for their role in the pathogenesis of POAG and thus are novel factors for further study of the mechanism of the disease and for their possible use as diagnostic markers.

A cost-effective transparency-based digital imaging for efficient and accurate wound area measurement.

Wound measurement is an objective and direct way to trace the course of wound healing and to evaluate therapeutic efficacy. Nevertheless, the accuracy and efficiency of the current measurement methods need to be improved. Taking the advantages of reliability of transparency tracing and the accuracy of computer-aided digital imaging, a transparency-based digital imaging approach is established, by which data from 340 wound tracing were collected from 6 experimental groups (8 rats/group) at 8 experimental time points (Day 1, 3, 5, 7, 10, 12, 14 and 16) and orderly archived onto a transparency model sheet. This sheet was scanned and its image was saved in JPG form. Since a set of standard area units from 1 mm(2) to 1 cm(2) was integrated into the sheet, the tracing areas in JPG image were measured directly, using the "Magnetic lasso tool" in Adobe Photoshop program. The pixel values/PVs of individual outlined regions were obtained and recorded in an average speed of 27 second/region. All PV data were saved in an excel form and their corresponding areas were calculated simultaneously by the formula of Y (PV of the outlined region)/X (PV of standard area unit) × Z (area of standard unit). It took a researcher less than 3 hours to finish area calculation of 340 regions. In contrast, over 3 hours were expended by three skillful researchers to accomplish the above work with traditional transparency-based method. Moreover, unlike the results obtained traditionally, little variation was found among the data calculated by different persons and the standard area units in different sizes and shapes. Given its accurate, reproductive and efficient properties, this transparency-based digital imaging approach would be of significant values in basic wound healing research and clinical practice.

Distinct sulfonation activities in resveratrol-sensitive and resveratrol-insensitive human glioblastoma cells.

Glioblastoma multiforme (GBM) cells show different responses to resveratrol, for unknown reasons. Our data from human medulloblastoma cells and primary cultures of rat brain cells revealed an inverse correlation of sulfonation activity with resveratrol sensitivities, providing a clue to the underlying mechanisms of the variable sensitivities of GBM cells to resveratrol. In this study, we found that U251 cells were sensitive and LN229 cells were insensitive to resveratrol. Thus, these two cell lines were taken as comparable models for elucidating the influence of sulfonation activities on resveratrol sensitivity. HPLC showed identical resveratrol metabolic patterns in both cell lines. LC/MS and high-resolution mass MS analyses further demonstrated that resveratrol monosulfate generated by sulfotransferases (SULTs) was the major metabolite of human GBM cells. The levels of brain-associated SULT (SULT1A1, SULT1C2, and SULT4A1) expression in U251 cells were lower than those in LN229 cells, suggesting the inverse relationship of SULT-mediated sulfonation activity with high intracellular resveratrol bioavailability and resveratrol sensitivity of human GBM cells. Furthermore, immunohistochemical staining revealed reductions in expression of the three brain-associated SULTs in 72.8%, 47.5% and 66.3% of astrocytomas, respectively. Therefore, the levels of brain-associated SULTs and sulfonation activity mediated by them could be important parameters for evaluating the potential response of human GBM cells to resveratrol, and may have value in the personalized treatment of GBMs with resveratrol.

CRABP-II- and FABP5-independent all-trans retinoic acid resistance in COLO 16 human cutaneous squamous cancer cells.

The effect of all-trans retinoic acid (ATRA) on cutaneous squamous cell carcinomas (c-SCC) has been poorly described. Because the imbalance of CRABP-II-mediated anticancer signalling and FABP5-mediated growth-promoting signalling was supposed to be related with ATRA sensitivities of cancer cells, COLO16 human c-SCC cell line was selected to check underlying mechanism leading to ATRA resistance by multiple experimental approaches. The results revealed that COLO 16 cells were resistant to 15 µm ATRA treatment. FABP5 as well as the elements related with CRABP-II signalling (CYP26A1, CYP26B1, CRABP-I, RARα/ß/γ and RXRα/ß/γ) and with FABP5 signalling (PPARß/δ) were expressed, but CRABP-II was undetectable in COLO 16 cells. 5-Aza treatment enhanced CRABP-II expression but further bisulfite sequencing PCR-DNA sequencing revealed no methylation in CRABP-II promoter region. Transfection of CRABP-II-expressing plasmids or FABP5 siRNA or both successfully manipulated the level(s) of target gene expression but failed to overcome ATRA resistance in the transfectants. In conclusion, CRABP-II and FABP5 expression were imbalanced in ATRA-resistant COLO 16 cells. 5-Aza-enhanced CRABP-II expression and unmethylation in CRABP-II promoter region suggest the methylation of certain CRABP-II regulatory gene(s) in COLO 16 cells. As neither restoration of CRABP-II expression nor the increased CRABP-II versus FABP5 ratio can overcome ATRA resistance of COLO 16 cells, additional ATRA-resistant mechanism(s) may present in human c-SCCs and COLO 16 cells would be of value in addressing this issue.