Maggot extract accelerates skin wound healing of diabetic rats via enhancing STAT3 signaling.

BACKGROUND: Diabetic skin wound is a complex problem due to the disruption of normal repairing program and lack of effective remedy. Lucilia sericata larvae (maggot) is a folk method to treat chronic skin wound, while its therapeutic effects on that caused by diabetic remains unknown. OBJECTIVE: This study aims to investigate the therapeutic effects of maggot extract (M.E.) on diabetic skin wound and its molecular mechanism by establishing the skin wound model of diabetic Sprague Dawley (SD) rats. METHODS: Diabetic model was established by injecting intraperitoneally streptozotocin in SD rats under specific pathogen-free (SPF) conditions. The rat fasting blood glucose values were ≧16.7 mmol/L 72 hours after intraperitoneal streptozotocin (60mg/kg body weight) injection. The rats were divided into five groups (n = 10/group): normal group: normal SD rats without any treatment, diabetic blank group: the diabetic rats without any treatment, Vaseline group: the diabetic rats dressed with Vaseline, recombinant human epidermal-growth-factor (rhEGF) group: the diabetic rats dressed with a mixture of Vaseline and 200 µg/g rhEGF, M.E. group: the diabetic rats dressed with a mixture of Vaseline and 150 µg/ml maggot extract. The round open wounds (1.0 cm in diameter) down to the muscle fascia were made on both sides of rat dorsa by removing the skin layer (epidermis and dermis) and were daily photographed for calculating their healing rates. Hematoxylin-eosin (HE) and Masson's trichrome staining were performed on skin wound sections to analyze re-epithelialization and granulation tissue formation. Immunohistochemical (IHC), immunofluorescent (IF) stainings and Western blotting were conducted to analyze the statuses of STAT3 signaling. RESULTS: The average wound healing rates on the 14th day were 91.7% in the normal, 79.6% in M.E., 71% in rhEGF, 55.1% in vaseline and 43.3% in the diabetes blank group. Morphological staining showed more active granulation tissue formation, re-epithelialization and neovascularization in M.E.-group than those in the blank and the vaseline-treated groups. Decreased p-STAT3 nuclear tranlocation and down-regulated Bcl-2, CyclinD1 and vascular endothelial growth factor (VEGF) expression were evidenced in the diabetic rats, which could be improved by rhEGF and especially M.E. CONCLUSION: Maggot extract would be an alternative and/or adjuvant candidate for the better management of diabetic skin wounds because of its activity in enhancing STAT3 activation.

Pyrimidine compounds BY4003 and BY4008 inhibit glioblastoma cells growth via modulating JAK3/STAT3 signaling pathway.

Glioblastoma (GBM) is a brain tumor characterized by its aggressive and invasive properties. It is found that STAT3 is abnormally activated in GBM, and inhibiting STAT3 signaling can effectively suppress tumor progression. In this study, novel pyrimidine compounds, BY4003 and BY4008, were synthesized to target the JAK3/STAT3 signaling pathway, and their therapeutic efficacy and mechanisms of action were evaluated and compared with Tofacitinib in U251, A172, LN428 and patient-derived glioblastoma cells. The ADP-Glo™ kinase assay was utilized to assessed the inhibitory effects of BY4003 and BY4008 on JAK3, a crucial member of the JAK family. The results showed that both compounds significantly inhibited JAK3 enzyme activity, with IC50 values in the nanomolar range. The antiproliferative effects of BY4003, BY4008, and Tofacitinib on GBM and patient-derived glioblastoma cells were evaluated by MTT and H&E assays. The impact of BY4003 and BY4008 on GBM cell migration and apoptosis induction was assessed through wound healing, transwell, and TUNEL assays. STAT3-regulated protein expression and relative mRNA levels were analyzed by western blotting, immunocytochemistry, immunofluorescence, and qRT-PCR. It was found that BY4003, BY4008 and Tofacitinib could inhibit U251, A172, LN428 and patient-derived glioblastoma cells growth and proliferation. Results showed decreased expression of STAT3-associated proteins, including p-STAT3, CyclinD1, and Bcl-2, and increased expression of Bax, a pro-apoptotic protein, as well as significant down-regulation of STAT3 and STAT3-related genes. These findings suggested that BY4003 and BY4008 could inhibit GBM growth by suppressing the JAK3/STAT3 signaling pathway, providing valuable insights into the therapeutic development of GBM.

Analysis of the effects of postoperative cluster nursing care on the incidence rate of postoperative complications and nutritional indicators in patients with primary laryngeal cancer.

OBJECTIVE: In this study, we investigated the effects of cluster nursing care on postoperative infection risk and nutritional indicators in patients with primary laryngeal cancer. METHODS: This study comprised 50 patients with primary laryngeal cancer diagnosed between March 2020 and December 2022. They were randomly divided into the test and control groups, with each group comprising 25 patients. The test group received cluster nursing care, while the control group received standard nursing care. Indicators for quantitative scoring, such as Patient Generated Subjective Global Assessment (PG-SGA), Zubrod Performance Status (ZPS), Karnofsky score, and Nutrition Risk Screening 2002 (NRS-2002), measurement indicators such as body mass index (BMI), body mass, hip circumference, calf circumference, grip strength, weight loss, and laboratory indicators, such as hemoglobin, albumin, and transaminase levels, were used to analyze change. RESULTS: Improvements were observed in the scores of PG-SGA, ZPS, and NRS-2002 in the test group following the implementation of nursing care for the test and control groups for 1 week, which were statistically significantly different from those at baseline (P < 0.05), and compared to the control group (P < 0.05). No statistically significant differences were observed in other indicators (P > 0.05). There was a statistically significant difference (P < 0.05) between the incidence rate of infections and complications in the test and control groups, which were 20.00% and 48.00%. CONCLUSION: The postoperative nutritional status of patients with primary laryngeal cancer improved in phases through specialized nursing care. It is also a factor closely related to postoperative complications.

Correlation between plasma lycopene levels in patients with laryngeal carcinoma and postoperative adverse complications of chemoradiotherapy and nutritional risks.

OBJECTIVE: In this study, we analyzed the correlation between the preoperative plasma lycopene levels, postoperative adverse complications of chemoradiotherapy, and nutritional risk scores in patients with laryngeal carcinoma. METHODS: A total of 114 patients with laryngeal carcinoma and 114 healthy respondents were enrolled in this study. The patients with laryngeal carcinoma were divided into two groups: 62 patients with laryngeal carcinoma, with an NRS2002 score higher than 3 points and whose diet contained lycopene, were enrolled in the observation group, and 52 patients with laryngeal carcinoma during the corresponding time period, whose diet did not contain lycopene, were enrolled in the reference group. The immune indexes (CD4 + , CD8 + , IGA, IGM, IGG), nutritional indexes (albumin, prealbumin, transferrin), and postoperative adverse complications of chemo-radiotherapy in the two groups were recorded. RESULTS: The lycopene levels were lower in patients with advanced tumor stage (III and IV). The diagnosis threshold of the plasma lycopene level for laryngeal carcinoma was 0.503 µmol/L. The area under the curve for plasma lycopene levels in cancer diagnosis was 0.96, with a clinical specificity of 0.943 and a sensitivity of 0.859. There was a significant negative correlation between the plasma lycopene levels and Nutrition Risk Screening (NRS) 2002 score (R2 = - 0.523, P < 0.001), which was related to the increase in NRS-2002 scores and nutritional hazards in patients with laryngeal carcinoma. The observation group showed a significant increase in nutritional and immune indices, as compared to the reference group, as well as a lower incidence of severe and serious adverse reactions to chemo-radiotherapy. Lycopene supplementation, tumor stage, NRS-2002 scores, nutritional and immune indices were all significant predictors of postoperative severe and serious adverse complications of chemoradiotherapy. CONCLUSION: Progression of laryngeal carcinoma and severity of the side effects of the adverse complications of chemo-radiotherapy are related to the levels of lycopene.

Resveratrol Enhances Temozolomide Efficacy in Glioblastoma Cells through Downregulated MGMT and Negative Regulators-Related STAT3 Inactivation.

Chemoresistance blunts the efficacy of temozolomide (TMZ) in the treatment of glioblastoma (GBM). Elevated levels of O6-methylguanine-DNA methyltransferase (MGMT) and activation of signal transducer and of transcription 3 (STAT3) have been reported to correlate with GBM resistance to alkylator chemotherapy. Resveratrol (Res) inhibits tumor growth and improves drug chemosensitivity by targeting STAT3 signaling. Whether the combined therapy of TMZ and Res could enhance chemosensitivity against GBM cells and the underlying molecular mechanism remains to be determined. In this study, Res was found to effectively improve chemosensitivities of different GBM cells to TMZ, which was evaluated by CCK-8, flow cytometry, and cell migration assay. The combined use of Res and TMZ downregulated STAT3 activity and STAT3-regulated gene products, thus inhibited cell proliferation and migration, as well as induced apoptosis, accompanied by increased levels of its negative regulators: PIAS3, SHP1, SHP2, and SOCS3. More importantly, a combination therapy of Res and TMZ reversed TMZ resistance of LN428 cells, which could be related to decreased MGMT and STAT3 levels. Furthermore, the JAK2-specific inhibitor AG490 was used to demonstrate that a reduced MGMT level was mediated by STAT3 inactivation. Taken together, Res inhibited STAT3 signaling through modulation of PIAS3, SHP1, SHP2, and SOCS3, thereby attenuating tumor growth and increasing sensitivity to TMZ. Therefore, Res is an ideal candidate to be used in TMZ combined chemotherapy for GBM.

Platelet-Rich Plasma Gel-Loaded Collagen/Chitosan Composite Film Accelerated Rat Sciatic Nerve Injury Repair.

Peripheral nerve injury (PNI) is a common clinical disease caused by severe limb trauma, congenital malformations, and tumor resection, which may lead to significant functional impairment and permanent disability. Nerve conduit as a method for treating peripheral nerve injury shows good application prospects. In this work, the COL/CS composite films with different mass ratios of 1:0, 1:1, and 1:3 were fabricated by combining physical doping. Physicochemical characterization results showed that the COL/CS composite films possessed good swelling properties, ideal mechanical properties, degradability and suitable hydrophilicity, which could meet the requirements of nerve tissue engineering. In vitro cell experiments showed that the loading of platelet-rich plasma (PRP) gel on the surface of COL/CS composite films could significantly improve the biocompatibility of films and promote the proliferation of Schwann cells. In addition, a rat model of sciatic nerve defect was constructed to evaluate the effect of COL/CS composite films on peripheral nerve repair and the results showed that COL/CS composite films loaded with PRP gel could promote nerve regeneration and functional recovery in rats with sciatic nerve injury, indicating that the combination of PRP gel with the COL/CS composite film would be a potential approach for the treatment of peripheral nerve injury.

Dual Inhibition of BRAF-MAPK and STAT3 Signaling Pathways in Resveratrol-Suppressed Anaplastic Thyroid Cancer Cells with BRAF Mutations.

Anaplastic thyroid cancer is an extremely lethal malignancy without reliable treatment. BRAFV600E point mutation is common in ATCs, which leads to MAPK signaling activation and is regarded as a therapeutic target. Resveratrol inhibits ATC cell growth, while its impact on BRAF-MAPK signaling remains unknown. This study aims to address this issue by elucidating the statuses of BRAF-MAPK and STAT3 signaling activities in resveratrol-treated THJ-11T, THJ-16T, and THJ-21T ATC cells and Nthyori 3-1 thyroid epithelial cells. RT-PCR and Sanger sequencing revealed MKRN1-BRAF fusion mutation in THJ-16T, BRAF V600E point mutation in THJ-21T, and wild-type BRAF genes in THJ-11T and Nthyori 3-1 cells. Western blotting and immunocytochemical staining showed elevated pBRAF, pMEK, and pERK levels in THJ-16T and THJ-21T, but not in THJ-11T or Nthyori 3-1 cells. Calcein/PI, EdU, and TUNEL assays showed that compared with docetaxel and doxorubicin and MAPK-targeting dabrafenib and trametinib, resveratrol exerted more powerful inhibitory effects on mutant BRAF-harboring THJ-16T and THJ-21T cells, accompanied by reduced levels of MAPK pathway-associated proteins and pSTAT3. Trametinib- and dabrafenib-enhanced STAT3 activation was efficiently suppressed by resveratrol. In conclusion, resveratrol acts as dual BRAF-MAPK and STAT3 signaling inhibitor and a promising agent against ATCs with BRAF mutation.

Increased brain uptake of pterostilbene loaded folate modified micellar delivery system.

Effective chemotherapy for clinical treatment of brain diseases is still lacking due to the poor penetration of the blood-brain barrier (BBB). The aim of this study was to construct a folate modified pterostilbene (Pt) loaded polymeric micellar delivery system (F-Pt/M) with mPEG-PCL as carrier material to aim at penetrating the BBB for brain tissue targeting via receptor-mediated endocytosis. In this study, F-Pt/M was prepared using thin-film hydration method and then optimized by response surface methodology (RSM) with the entrapment efficiency (EE), drug loading (DL) and hydrodynamic diameter (HD) as indexes. The average hydrodynamic diameter and zeta potential of optimal F-Pt/M were 133.2 nm and 24.6 mV, respectively. DL (18.3%) and EE (98.6%) made the solubility of Pt in water about 25 times higher than that of crude Pt. Results of DSC evaluation revealed that drugs were successfully encapsulated inside the polymeric micelles. TEM images showed that homogeneous spherical micellar structures with a narrow size distribution were developed. The release result in vitro showed that F-Pt/M presented sustained release behavior compared to control free Pt solution. Compared to non-targeted Pt/M, F-Pt/M had a significantly higher cytotoxicity against FR-overexpressing A172 cells. In vitro cellular uptake tests illustrated that the micellar delivery system could significantly improve the accumulation of drugs in target cells via receptor-mediated endocytosis. BBB penetration value (P) of F-Pt/M was about 4 folds higher than that of free Pt group. In addition, drug targeting index (DTI) was calculated to determine targeting of F-Pt/M to the brain which was found to be 4.89, implying improved brain targeting was achieved. Hence, the developed F-Pt/M exhibited great potential for delivering more drug molecules across the BBB for the treatment of brain diseases.

Frequently expressed glypican-3 as a promising novel therapeutic target for osteosarcomas.

Osteosarcoma (OS) is the most common bone malignancy without a reliable therapeutic target. Glypican-3 (GPC3) mutation and upregulation have been detected in multidrug resistant OS, and anti-GPC3 immunotherapy can effectively suppress the growth of organoids. Further profiling of GPC3 mutations and expression patterns in OS is of clinical significance. To address these issues, fresh OS specimens were collected from 24 patients for cancer-targeted next-generation sequencing (NGS) and three-dimensional patient-derived organoid (PDO) culture. A tumor microarray was prepared using 37 archived OS specimens. Immunohistochemical (IHC) staining was performed on OS specimens and microarrays to profile GPC3 and CD133 expression as well as intratumoral distribution patterns. RT-PCR was conducted to semiquantify GPC3 and CD133 expression levels in the OS tissues. Anti-GPC3 immunotherapy was performed on OS organoids with or without GPC3 expression and its efficacy was analyzed using multiple experimental approaches. No OS cases with GPC3 mutations were found, except for the positive control (OS-08). IHC staining revealed GPC3 expression in 73.77% (45/61) of OSs in weak (+; 29/45), moderate (++; 8/45), and strong (+++; 8/45) immunolabeling densities. The intratumoral distribution of GPC3-positive cells was variable in the focal (+; 10%-30%; 8/45), partial (++; 31%-70%; 22/45), and the most positive patterns (+++; >71%; 15/45), which coincided with CD133 immunolabeling (P = 9.89 × 10-10 ). The anti-GPC3 antibody efficiently inhibits Wnt/ß-catenin signaling and induces apoptosis in GPC3-positive PDOs and PDXs, as opposed to GPC3-negative PDOs and PDXs. The high frequency of GPC3 and CD133 co-expression and the effectiveness of anti-wild-type GPC3-Ab therapy in GPC3-positive OS models suggest that GPC3 is a novel prognostic parameter and a promising therapeutic target for osteosarcoma.

Higher efficacy of resveratrol against advanced breast cancer organoids: A comparison with that of clinically relevant drugs.

The lack of reliable drugs is a therapeutic challenge of advanced breast cancers (ABCs). Resveratrol (Res) exerts inhibitory effects on breast cancer cell lines and animal models, while its efficacy against individual breast cancer cases remains unknown. This study aims to use ABC-derived organoids (ABCOs) as the ex vivo therapeutic platform to clarify the effectiveness of resveratrol against different ABC subtypes. Immunohistochemical staining confirmed that the ABCOs maintained their original tumors' ER, PR, HER2, and Ki67 expression patterns. ABCO proliferation and viability tests showed >50% cell death rates in 79.2% (19/24) of Res-treated, 28.6% (2/7) fulvestrant-treated, 66.7% (4/6) paclitaxel-treated, and 66.7% (6/9) gemcitabine-treated ABCOs. pSTAT3 nuclear translocation was more frequent in Res-sensitive (17/19; 89.47%) than that (1/5; 20%) of Res-insensitive ABCOs, which were suppressed upon Res treatment. Statistical analysis revealed a close correlation of STAT3 activation with the efficacy of Res, but not related to tumor receptor expression patterns (ER, PR, HER2) and pathological classification. We demonstrate for the first time the higher efficacy and broader spectrum of Res against different subtypes of ABCOs in comparison with that of conventional antibreast cancer drugs, providing an alternative approach for better management of ABCs.

Increased Reactive Oxygen Species and Distinct Oxidative Damage in Resveratrol-suppressed Glioblastoma Cells.

Background and Aim: Glioblastoma multiforme (GBM) is a highly aggressive brain malignancy that lacks reliable treatments. Resveratrol possesses anti-cancer effects, but its activity against glioblastoma cells is variable for unknown reasons. One mechanism through which anti-cancer drugs exert their effects is oxidative damage caused by increased reactive oxygen species (ROS) production. Thus, the present study examined the relationship between oxidative stress and sensitivity to resveratrol in glioblastoma cells. Methods: Two GBM cell lines (U251 and LN428) were exposed to 100 µM resveratrol for 48 h, and proliferation and apoptosis were assessed. ROS generation was evaluated using 2'-7'-dichlorodihydrofluorescein diacetate-based flow cytometry and fluorescent microscopy. Immunocytochemical staining and western blotting were conducted at regular intervals to profile the expression patterns of superoxide dismutase-2 (SOD2), catalase, caspase-9, caspase-3, and sulfotransferases (SULTs) in untreated and resveratrol-treated GBM cells. Results: Resveratrol-treated U251 cells, but not resveratrol-treated LN428 cells, exhibited remarkable growth arrest and extensive apoptosis accompanied by elevated intracellular ROS levels and attenuated SOD2 and catalase expression. Mitochondrial impairment and more distinct increases in the expression of activated caspase-9 and caspase-3 were detected in U251 cells following resveratrol treatment. The levels of resveratrol metabolic enzymes (SULT1A1 and SULT1C2) were lower in U251 cells than in LN428 cells. Conclusions: Resveratrol increased ROS generation and induced oxidation-related cellular lesions in U251 cells by activating an ROS-related mitochondrial signal pathway. The levels of SULTs and ROS may indicate the therapeutic outcomes of resveratrol treatment in GBM.

Synergistic Effects of Resveratrol and Temozolomide Against Glioblastoma Cells: Underlying Mechanism and Therapeutic Implications.

PURPOSE: Temozolomide (TMZ) is a commonly used anti-glioblastoma (GBM) drug. However, glioblastoma cells frequently show primary and acquired resistance to TMZ. As a promising anti-GBM candidate, resveratrol (Res) faces the similar problem as TMZ. Although resveratrol combined with TMZ (Res/TMZ) has been reported to be used to treat GBMs, it remains unclear whether this combination is broad-spectrum for all glioma cells until now, especially for GBM cells/cases with dual drug resistance. The study aimed to evaluate the synergistic effects of resveratrol and TMZ against GBMs and identify the underlying mechanisms. MATERIALS AND METHODS: Drug sensitivities of rat RG-2, human LN-18 and LN-428 cell lines and effectiveness of Res/TMZ combinations were investigated via multiple experimental methods. O6-methylguanine-DNA methyltransferase (MGMT) was observed by Western blotting and immunocytochemistry (ICC). Transducer and activator of transcription 3 (STAT3) signaling pathway and expression changes of STAT3-related gene were detected to explore the possible synergistic mechanism. RESULTS: One hundred micromolar resveratrol and 500 µM TMZ inhibited the growth of RG-2 cells and the low-dose combination (25 µM/250 µM) showed similar suppressive effects. LN-18 and, especially, LN-428 cells were neither sensitive to 100 µM resveratrol nor to 500 µM TMZ, while their growth was suppressed by combination of 75 µM Res/750 µM TMZ with the suppressive rates of 62.5% and 28.6% and apoptosis rates of 11.9% and 7.4%, respectively. Resveratrol had regulatory effect on the expression of MGMT and it could significantly down-regulate MGMT overexpression caused by TMZ. In addition, STAT3/Bcl-2/survivin signaling pathway was also remarkably inhibited in Res/TMZ-treated GBM cells. CONCLUSION: Our results demonstrated synergistic effects of Res/TMZ on RG-2 cells and their bilaterally sensitizing effects to LN-18 and LN-428 cells. Frequent upregulation of MGMT and activation of STAT3 are the unfavorable factors for the treatment of GBMs and they may be the potential targets of Res/TMZ therapy.

Intra-articular delivery of flurbiprofen sustained release thermogel: improved therapeutic outcome of collagenase II-induced rat knee osteoarthritis.

Knee osteoarthritis (OA) is a common degenerative disease. Intra-articular administration of flurbiprofen is frequently employed in clinic to treat OA, while repeated injections are required because of the limited effective duration. To improve therapeutic outcome and prolong the treatment interval, a poly(ε-caprolactone-co-lactide)-b-poly(ethylene glycol)-b-poly(ε-caprolactone-co-lactide) (PCLA-PEG-PCLA) triblock copolymer based flurbiprofen thermosensitive gel for the sustained intra-articular drug delivery was designed in this study. The anti-OA effects of this flurbiprofen thermogel were investigated on collagenase II-induced rat knee OA model by multiple approaches and compared with that of conventional sodium hyaluronate and flurbiprofen injecta. In vitro drug release studies indicated that flurbiprofen was sustained released from the thermosensitive gel for more than three weeks. This sustained drug release system exerted comparable short-term analgesic effects and distinctly improved long-term analgesic efficacy in terms of the increased percentage of the total ipsilateral paw print intensity and the reduced Knee-Bend scores of OA rats. The inflammatory response was attenuated in the samples of flurbiprofen gel treated group by showing decreased IL-1, IL-6, and IL-11 levels in the joint fluid and down-regulated IL-1, IL-6, IL-11, COX-2, TNF-α, and NF-κB/p65 expression in the articular cartilages. The results suggest the suitability of thermosensitive copolymer PCLA-PEG-PCLA for sustained intra-articular effects of flurbiprofen and provide in vivo experimental evidence for potential clinical application of this flurbiprofen delivery system to better management of OA cases.

STAT3 signaling statuses determine the fate of resveratrol-treated anaplastic thyroid cancer cells.

BACKGROUNDS: Anaplastic thyroid cancer/ATC is highly lethal malignancy without reliable chemotherapeutic drug. Resveratrol possesses anti-ATC activities but encounters resistance in some cases due to certain unknown reason(s). OBJECTIVE: Because signal transducer and activator of transcription/STAT3 signaling is critical for ATC cell survival and the main molecular target of resveratrol, its roles in determining the fates of resveratrol-treated ATC cells were investigated here. METHODS: Human THJ-11T, THJ-16 and THJ-21T ATC cell lines were treated by 100 µM resveratrol and their growth, statuses of STAT3 signaling and STAT3-related gene expression were examined. The relevance of STAT3 activation with resveratrol resistance was elucidated using STAT selective inhibitor AG490. Leukemia inhibitory factor/LIF expression and phosphorylated-STAT3/p-STAT3 nuclear translocation in ATC tissues were immunohistochemically analyzed. RESULTS: Resveratrol inhibited proliferation, p-STAT3 nuclear translocation as well as LIF and STAT3 expression of THJ-16T and THJ-21T but not THJ-21T cells which showed LIF upregulation and more frequent p-STAT3 nuclear translocation. AG490 significantly prevent p-STAT3 nuclear translocation, and reversed the resveratrol tolerance of THJ-11T cells. Immonohistochemical staining revealed 14.3% (4/28) of LIF and 3.6% (1/28) of p-STAT3 detection in noncancerous ATC-surrounding tissues, which increased to 89.5% (17/19) and 52.6% (10/19) respectively among ATC specimens. The correlative analysis indicated the relevance of LIF expression and STAT3 activation (r= 0.825; P< 0.01). CONCLUSIONS: The status of STAT3 activation and LIF expression are closely correlated with the therapeutic effect of resveratrol on ATCs. Frequent LIF upregulation and STAT3 activation are the unfavorable factors of ATCs and the potential targets of anti-ATC therapy.

Resveratrol Downregulates STAT3 Expression and Astrocyte Activation in Primary Astrocyte Cultures of Rat.

Astrocytes respond to all forms of central nervous system (CNS) insults by a process referred to as reactive astrogliosis. Inhibition of astrocyte growth and activation is an important strategy for promoting injured CNS repair. STAT3 (signal transducer and activator of transcription 3) is reported to be a critical regulator of astrogliosis, and resveratrol (RES, a dietary polyphenol) is considered to be a natural inhibitor of STAT3 expression and phosphorylation. In this study, we investigated the effects of RES on STAT3 expression and phosphorylation, and then on the proliferation and activation of astrocytes, a critical process in reactive astrogliosis, in rat primary cultured astrocytes and an in vitro scratch-wound model. RES downregulated the expression levels of STAT3, P-STAT3 and GFAP (glial fibrillary acidic protein) in cultured astrocytes. The positive index of Ki67 was apparently reduced in cultured astrocytes after RES treatment. Meanwhile, cultured astrocyte proliferation and activation were attenuated by RES. Moreover, in the established in vitro scratch-wound model the increased expression levels of STAT3, P-STAT3 and GFAP induced by scratching injury were also clearly inhibited by RES. In addition, the inhibitory effect of RES on cell proliferation was similar to that of AG490 (a selective inhibitor of STAT3 phosphorylation) and abrogated by Colivelin (a STAT3 activator) stimuli. Taken together, our data suggest that RES is able to inhibit reactive astrocyte proliferation and activation mainly via deactivating STAT3 pathway. So RES may have a therapeutic benefit for the treatment of the injured CNS.

Resveratrol Reverses Retinoic Acid Resistance of Anaplastic Thyroid Cancer Cells via Demethylating CRABP2 Gene.

Background: Cellular retinoic acid binding protein 2 (CRABP2) mediates retinoic acid/RA anti-cancer pathways. Resveratrol effectively reverses RA tolerance and upregulates CRABP2 expression of anaplastic thyroid cancer cell line THJ-11T. As DNA methylation is responsible for CRABP2 silencing, the CRABP2 methylation status of THJ-11T cells and the demethylating effect of resveratrol on this gene are elucidated. Materials and methods: The statuses of CRABP2 expression and methylation and the levels of DNA methyltransferases (DNMTs) DNMT1, DNMT3A, and DNMT3B of THJ-11T cells were examined before and after resveratrol treatment via multiple experimental methods. The human medulloblastoma UW228-2 cell line was cited as the control of CRABP2 methylation and gemcitabine as the demethylator control. Results: RT-PCR, immunocytochemical staining and Western blotting showed that resveratrol significantly increased the CRABP2 expression and RA sensitivity of THJ-11T and UW228-2 cells. Bisulfite sequencing showed five CpG methylation sites at the CRABP2 promoter region of both cell lines, which were partially (3/5) demethylated by resveratrol and totally (5/5) by gemcitabine. DNMT1, DNMT3A, and DNMT3B were reduced in UW228-2 cells and DNMT1 and DNMT3A were reduced in THJ-11T cells after resveratrol treatment in a time-related fashion. Conclusion: Resveratrol is able to erase CRABP2 methylation and can thereby increase the RA sensitivity of THJ-11T and UW228-2 cells. This study demonstrates the additional value of the natural polyphenolic compound resveratrol as a demethylator in cancer treatments.

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.

Negative regulators of STAT3 signaling pathway in cancers.

STAT3 is the most ubiquitous member of the STAT family and involved in many biological processes, such as cell proliferation, differentiation, and apoptosis. Mounting evidence has revealed that STAT3 is aberrantly activated in many malignant tumors and plays a critical role in cancer progression. STAT3 is usually regarded as an effective molecular target for cancer treatment, and abolishing the STAT3 activity may diminish tumor growth and metastasis. Recent studies have shown that negative regulators of STAT3 signaling such as PIAS, SOCS, and PTP, can effectively retard tumor progression. However, PIAS, SOCS, and PTP have also been reported to correlate with tumor malignancy, and their biological function in tumorigenesis and antitumor therapy are somewhat controversial. In this review, we summarize actual knowledge on the negative regulators of STAT3 in tumors, and focus on the potential role of PIAS, SOCS, and PTP in cancer treatment. Furthermore, we also outline the STAT3 inhibitors that have entered clinical trials. Targeting STAT3 seems to be a promising strategy in cancer therapy.

Differential Exosomic Proteomic Patterns and Their Influence in Resveratrol Sensitivities of Glioblastoma Cells.

Glioblastoma multiforme (GBM) is the commonest primary brain malignancy with extremely poor prognosis. Resveratrol posseses anti-cancer effects, while GBM cells respond differently to it due to certain unknown reason(s). Because the tumor-derived exosomes are supposed to influence chemosensitivity, the exosomic proteins released from resveratrol-sensitive U251 and resveratrol-resistant glioblastoma LN428 cells are profiled before (N/Exo) and after drug treatment (Res/Exo) by label-free liquid chromatography-mass spectrometry (LC-MS). The therapeutic implications of the proteomic findings are estimated by gene ontology enrichment analysis (GO) and the Kyoto Encyclopedia of Genes and Genomes (KEGG)-based bioinformatic analyses and further elucidated by exosome co-incubating. The results reveal that U251/N/Exo but not U251/Res/Exo enhances resveratrol sensitivity of resveratrol-resistant LN428 cells. The resveratrol sensitive properties of U251 cells are not altered by either LN428/N/Exo or LN428/Res/Exo. U251/N/Exo contains higher levels of chromatin silencing and epidermis development proteins, while U251/Res/Exo has more oxygen transport and G protein-coupled receptor. Both of LN428/N/Exo and LN428/Res/Exo are rich in the proteins related with nucleosome assembly, microtubule-based process and chromatin silencing. In conclusion, U251/N/Exo sensitizes LN428 cells to resveratrol via delivering drug sensitizing signals, suggesting the presence of additional factor(s) that may determine the resveratrol sensitivities of glioblastoma cells.

A panel of biomarkers for skin squamous cell carcinoma: various functional entities and differential responses to resveratrol.

In contrast to the highly malignant melanoma, skin squamous cell carcinoma (SCC) usually presents with lower morbidity. However, its incidence has been alarmingly rising worldwide and is a public health burden, let alone the current SCC cancer classification scheme is inadequate. Due to its features of progressing along different pathologic stages, early detection of precancerous lesions with accurate molecular markers would be desirable for cancer prevention and treatment. In the present study, using immunohistochemical staining of 85 clinical samples, we profiled the expression of a panel of ten proteins from five functional divisions implicated in SCC development, i.e. cytokeratins, intercellular molecules, chaperone proteins, transcription factors, and mitochondrial redox enzymes. The differential alterations of the proteins in SCC cell lines SCL12 and COLO16, upon resveratrol therapy, were also examined by immunocytochemistry (ICC). Our data reveal that, while all these proteins show significant correlation with cancer initiation and/or progression, a comprehensive panel encompassing a range of biologic functions, instead of a single marker, will provide prognostic value in SCC diagnosis and management. Additionally, the strong correlation among the proteins with cancer stages implies their distinct roles in SCC pathogenesis and contributions to the therapeutic effects of resveratrol, which is demonstrated in the resveratrol-sensitive COLO16 cells, but not in the resveratrol-resistant SCL12 cells.