Differential relieving effects of shikonin and its derivatives on inflammation and mucosal barrier damage caused by ulcerative colitis.

BACKGROUND: Ulcerative colitis (UC) is one of the most challenging human diseases. Natural shikonin (SK) and its derivatives (with have higher accumulation) isolated from the root of Lithospermum erythrorhizon have numerous beneficial effects, such as wound healing and anti-inflammatory activities. Some researchers have reported that hydroxynaphthoquinone mixture (HM) and SK attenuate the acute UC induced by dextran sulfate sodium (DSS). However, no existing study has systemically investigated the effectiveness of SK and other hydroxynaphthoquinone natural derivative monomers on UC. METHODS: In this study, mice were treated with SK and its derivatives (25 mg/kg) and mesalazine (200 mg/kg) after DSS administration daily for one week. Disease progression was monitored daily by observing the changes in clinical signs and body weight. RESULTS: Intragastric administration natural single naphthoquinone attenuated the malignant symptoms induced by DSS. SK or its derivatives remarkably suppressed the serum levels of pro-inflammatory cytokines while increasing the inflammatory cytokine interleukin (IL)-10 . Additionally, both SK and alkanin restrained the activities of cyclooxygenase-2 (COX-2), myeloperoxidase (MPO) and inducible nitric oxide synthase (iNOS) in serum and colonic tissues. SK and its derivatives inhibited the activation of nucleotide binding oligomerization domain-like receptors (NLRP3) inflammasome and NF-κB signaling pathway, thereby relieving the DSS-induced disruption of epithelial tight junction (TJ) in colonic tissues. CONCLUSIONS: Our findings shed more lights on the pharmacological efficacy of SK and its derivatives in UC against inflammation and mucosal barrier damage.

Shikonin and 4-hydroxytamoxifen synergistically inhibit the proliferation of breast cancer cells through activating apoptosis signaling pathway in vitro and in vivo.

BACKGROUND: Tamoxifen (TAM) is a cell type-specific anti-estrogen and is applied to improve the survival of patients with estrogen receptor positive (ER +) breast cancer. However, long-term TAM use can induce serious drug resistance, leading to breast cancer recurrence and death in patients. Further, it is almost useless among patients with estrogen receptor negative (ER -) breast cancer. Shikonin (SK) is a natural product broadly explored in cancer therapy. Some studies have demonstrated the combined treatment of SK and clinical anticancer drugs including TAM on various tumors. However, the combined effect of SK and 4-hydroxytamoxifen (4-OHT) on ER- breast cancer is not known. The current study aimed to assess the combination effects of SK and 4-OHT on human breast cancer cells, MCF-7 (ER +) and MDA-MB-435S (ER -), in vitro and in vivo and to investigate the underlying mechanisms. METHODS: CCK-8 assays and flow cytometry were conducted to determine the cell viability and apoptotic profiles of human breast cancer cell lines (MCF-7 and MDA-MB-435S) treated with SK, 4-OHT, and the combination. ROS and JC-1 assays were used to determine ROS level and mitochondrial membrane potential. Western blot analysis was performed to investigate proteins that are associated with apoptosis. Haematoxylin & Eosin (HE) staining was used to detect the tumor and kidney morphology of mice. TUNEL and immunohistochemical staining were performed to detect Ki67 expression level and cell apoptotic profile in tumor tissues. RESULTS: SK and 4-OHT synergistically inhibited MCF-7 and MDA-MB-435S cell proliferation and promoted apoptosis by reducing mitochondrial membrane potential and increasing the intracellular ROS level. The combination of SK and 4-OHT activated the mitochondrial-dependent apoptosis and the death receptor pathways, significantly regulating the PI3K/AKT/Caspase 9 signaling pathway. Compared with SK and 4-OHT alone, the combination of SK and 4-OHT could better inhibit tumor growth in mice. CONCLUSION: The combination of SK and 4-OHT shows highly efficient anticancer effects on breast cancer therapy. SK may be a promising candidate as an adjuvant to 4-OHT for breast cancer treatments, especially for ER- breast cancer.

Design, synthesis and biological evaluation of benzoylacrylic acid shikonin ester derivatives as irreversible dual inhibitors of tubulin and EGFR.

In this study, a series of shikonin derivatives combined with benzoylacrylic had been designed and synthesized, which showed an inhibitory effect on both tubulin and the epidermal growth factor receptor (EGFR). In vitro EGFR and cell growth inhibition assay demonstrated that compound PMMB-317 exhibited the most potent anti-EGFR (IC50 = 22.7 nM) and anti-proliferation activity (IC50 = 4.37 µM) against A549 cell line, which was comparable to that of Afatinib (EGFR, IC50 = 15.4 nM; A549, IC50 = 6.32 µM). Our results on mechanism research suggested that, PMMB-317 could induce the apoptosis of A549 cells in a dose- and time-dependent manner, along with decrease in mitochondrial membrane potential (MMP), production of ROS and alterations in apoptosis-related protein levels. Also, PMMB-317 could arrest cell cycle at G2/M phase to induce cell apoptosis, and inhibit the EGFR activity through blocking the signal transduction downstream of the mitogen-activated protein MAPK pathway and the anti-apoptotic kinase AKT pathway; typically, such results were comparable to those of afatinib. In addition, PMMB-317 could suppress A549 cell migration through the Wnt/ß-catenin signaling pathway in a dose-dependent manner. Additionally, molecular docking simulation revealed that, PMMB-317 could simultaneously combine with EGFR protein (5HG8) and tubulin (1SA0) through various forces. Moreover, 3D-QSAR study was also carried out, which could optimize our compound through the structure-activity relationship analysis. Furthermore, the in vitro and in vivo results had collectively confirmed that PMMB-317 might serve as a promising lead compound to further develop the potential therapeutic anticancer agents.

The evaluation of potent antitumor activities of shikonin coumarin-carboxylic acid, PMMB232 through HIF-1α-mediated apoptosis.

In current study, a series of shikonin derivatives were synthesized and its anticancer activity was evaluated. As a result, PMMB232 showed the best antiproliferation activity with an IC50 value of 3.25±0.35µM. Further, treatment of HeLa cells with a variety of concentrations of target drug resulted in dose-dependent event marked by apoptosis. What's more, the mitochondrial potential (Δym) analysis was consistent with the apoptosis result. In addition, PARP was involved in the progress of apoptosis revealed by western blotting. To identify the detailed role and mechanism of PMMB232 in the progression of human cervical cancer, we detected the expression of HIF-1α and E-cadherin in HeLa cells. Results showed that expression of HIF-1α was downregulated, while E-cadherin protein was upregulated. Meanwhile, glycolysis related protein PDK1 was decreased in HeLa cells. Conversely, the expression of PDH-E1α was upregulated. Docking simulation results further indicate that PMMB232 could be well bound to HIF-1α. Taken together, our data indicate that compound PMMB232 could be developed as a potential anticancer agent.

Design and characterization of α-lipoic acyl shikonin ester twin drugs as tubulin and PDK1 dual inhibitors.

Shikonin exhibits powerful anticancer activities for various cancer cells, but its poor solubility and strong toxicity hinder its development as clinical anticancer agent. We previously confirmed that shikonin and its derivatives can disturb mitosis through targeting tubulin. In this study, α-lipoic acid, the naturally-occurring co-factor of pyruvate dehydrogenase (PDH), was introduced into shikonin to design the twin drugs against both mitosis (tubulin) and glycolysis (PDK). 18 kinds of α-lipoic acid shikonin ester derivatives were achieved through three rounds of screening process performed by computer assistant drug design method, being designated as the outstanding compounds. Among them, 1c displayed the most potent cytotoxicity towards cervical cancer cells (HeLa) with an IC50 value of 3.14 ± 0.58 µM and inhibited xenotransplanted tumor growth in a dose-dependent manner. Further pharmacologic study demonstrated that 1c can cause cell cycle arrest in G2/M phase as tubulin polymerization inhibitor. Moreover, it also showed good PDK1 inhibitory activity, promoting PDH activity and forced HeLa cells to process more aerobic metabolism to undergo cell apoptosis. We reported here the first dual inhibitors of tubulin and PDK1 based on shikonin. It may form a basis for shikonin optimization through twin drug design framework for the discovery of new and potent shikonin derivatives in the study of targeted cancer therapy.

Design and synthesis of piperazine acetate podophyllotoxin ester derivatives targeting tubulin depolymerization as new anticancer agents.

In this paper, a series of podophyllotoxin piperazine acetate ester derivatives were synthesized and investigated due to their antiproliferation activity on different human cancer cell lines. Among the congeners, C5 manifested prominent cytotoxicity towards the cancer cells, without causing damage on the non-cancer cells through inhibiting tubulin assembly and having high selectively causing damage on the human breast (MCF-7) cell line (IC50=2.78±0.15µM). Treatments of MCF-7 cells with C5 resulted in cell cycle arrest in G2/M phase and microtubule network disruption. Moreover, regarding the expression of cell cycle relative proteins CDK1, a protein required for mitotic initiation was up-regulated. Besides, Cyclin A, Cyclin B1 and Cyclin D1 proteins were down-regulated. Meanwhile, it seems that the effect of C5 on MCF-7 cells apoptosis inducing was observed to be not obvious enough. In addition, docking analysis demonstrated that the congeners occupy the colchicine binding pocket of tubulin.

Identification of New Shikonin Derivatives as Antitumor Agents Targeting STAT3 SH2 Domain.

Signal transducer and activator of transcription 3 (STAT3) is hyper-activated in diversiform human tumors and has been validated as an attractive therapeutic target. Current research showed that a natural product, shikonin, along with its synthetic analogues, is able to inhibit the activity of STAT3 potently. The potential space of shikonin in developing novel anti-cancer agents encouraged us to carry out the investigation of the probable binding mode with STAT3. From this foundation, we have designed new types of STAT3 SH2 inhibitors. Combined simulations were performed to filter for the lead compound, which was then substituted, synthesized and evaluated by a variety of bioassays. Among the entities, PMM-172 exhibited the best anti-proliferative activity against MDA-MB-231 cells with IC50 value 1.98 ± 0.49 µM. Besides, it was identified to decrease luciferase activity, induce cell apoptosis and reduce mitochondrial transmembrane potential in MDA-MB-231 cells. Also, PMM-172 inhibited constitutive/inducible STAT3 activation without affecting STAT1 and STAT5 in MDA-MB-231 cells, and had no effect in non-tumorigenic MCF-10A cells. Moreover, PMM-172 suppressed STAT3 nuclear localization and STAT3 downstream target genes expression. Overall, these results indicate that the antitumor activity of PMM-172 is at least partially due to inhibition of STAT3 in breast cancer cells.

Design, Synthesis, and Biological Evaluation of Chalcone-Containing Shikonin Derivatives as Inhibitors of Tubulin Polymerization.

The biological importance of microtubules in mitosis makes them an interesting target for the development of anticancer agents. In this study, a series of novel chalcone-containing shikonin derivatives was designed, synthesized, and evaluated for biological activities. Among them, derivative PMMB-259 [(R)-1-(5,8-dihydroxy-1,4-dioxo-1,4-dihydronaphthalen-2-yl)-4-methylpent-3-en-1-yl (E)-2-(4-(3-oxo-3-(3-(trifluoromethoxy)phenyl)prop-1-en-1-yl)phenoxy)acetate] was identified as a potent inhibitor of tubulin polymerization. Further investigation confirmed that PMMB-259 can induce MCF-7 cell apoptosis, reduce the mitochondrial transmembrane potential, and arrest the cell cycle at the G2 /M phase. Moreover, the morphological variation of treated cells was visualized by confocal microscopy. The results, along with docking simulations, further indicated that PMMB-259 can bind well to tubulin at the colchicine site. Overall, these studies may provide a new molecular scaffold for the further development of antitumor agents that target tubulin.

Design, synthesis, biological evaluation, and 3D-QSAR analysis of podophyllotoxin-dioxazole combination as tubulin targeting anticancer agents.

The advancement of cancer-fighting drugs has never been a simple linear process. Those drug design professionals begin to find inspiration from the nature after failing to find the ideal products by creative drug design and high-throughput screening. To obtain new molecules for inhibiting tubulin, podophyllotoxin was adopted as the leading compound and 1,3,4-oxadiazole was brought in to the C-4 site of podophyllotoxin in this research. A series of seventeen podophyllotoxin-derived esters have been achieved and then evaluated their antitumor activities against four different cancer cell lines: A549, MCF-7, HepG2, and HeLa. Among all the compounds, compound 7c showed the best antiproliferating properties with IC50  = 2.54 ± 0.82 µm against MCF-7 cancer cell line. It was obvious that the content of ROS grew significantly in MCF-7 in a way depending on the dosage. The time- and dose-dependent cell cycle assays revealed that compound 7c could apparently block cell cycle in the phase of G2/M along with the upregulation of cyclin A2 and CDK2 protein. According to further studies, confocal microscopy experiment has certified that compound 7c could restrain cancer from growing by blocking the polymerization of microtubule. Meanwhile, compound 7c could be ideally integrated with the colchicine site of tubulin. In future, it would be feasible to selectively design tubulin inhibitors with the help of 3D-QSAR. This means that it is hopeful to develop compound 7c as a potential agent against cancer due to its biological characteristics.

Design, synthesis and anti-cancer activity evaluation of podophyllotoxin-norcantharidin hybrid drugs.

In this study, we designed and synthesized eighteen podophyllotoxin-norcantharidin hybrid drugs which could exhibit more potent anti-cancer activity than the parent drugs. Through the anti-proliferation assay, the most potent anti-cancer agent was screened out, namely Q9 (IC50=0.88±0.18µM against MCF-7 cell line), and it showed lower cytotoxicity against non-cancer cells, human embryonic kidney cells (293T) (IC50=54.38±3.78µM). Additionally, based on the flow cytometry analysis result, it can cause a remarkable cell cycle arrest at G2/M phase and induce apoptosis in MCF-7 cells more significantly than podophyllotoxin or norcantharidin per se. Moreover, the expression of cell cycle relative protein CDK1 was up regulated while a protein required for mitotic initiation, Cyclin B1 was down regulated. Furthermore, according to the confocal microscopy observation results, it was shown that Q9 was a potent tubulin polymerization inhibitor and the effect is comparable to that of colchicine. For further investigation on the aforementioned mechanisms, we performed western blot experiments, thus finding the increase of the cleavage of PARP. Consistent with these new findings, molecular docking observations suggested that compound Q9 could be developed as a potential anticancer agent.

Intracranial meningioma surgery in the elderly (over 65 years): prognostic factors and outcome.

BACKGROUND: Meningiomas are more prevalent in elderly individuals; however, the surgical outcome and prognostic factors in this age group are unclear. This retrospective study aimed to identify the prognostic factors of elderly patients with intracranial meningiomas who underwent surgical resection. METHODS: Eighty-six patients (aged ≥ 65) diagnosed with an intracranial meningioma were surgically treated at our department. The clinical, radiological, and follow-up data were retrospectively reviewed. Univariate and multivariate logistic analyses were performed to identify relationships between factors [age, sex, neurological condition, concomitant disease, American Society of Anesthesiology (ASA) classification, preoperative Karnofsky Performance Scale (KPS) score, tumor location and size, peritumoral edema, and Simpson resection grade] and outcome. RESULTS: One patient (1.2 %) died within 30 days of surgery. The morbidity rate was 37.2 %. Postoperative morbidities occurred more frequently in the patients with preoperative neurological deficits than in those without (p = 0.049). Univariate analysis identified significant relationships between a low KPS score (≤ 70) at discharge and preoperative neurological deficits, low preoperative KPS score (≤ 70), and critical tumor location (p < 0.001, p < 0.001, and p = 0.04, respectively). In the multivariate logistic analysis, only the preoperative KPS score remained significant for the KPS score at discharge (p = 0.005); there was no significant association with the most recent KPS score. CONCLUSION: The outcome of intracranial meningioma resection in elderly individuals is favorable if the preoperative KPS score is >70 and no neurological deficits are present. Treatment decisions should be patient-specific, and additional factors should be considered when operations are performed in patients with a low preoperative KPS score or neurological deficits.

A potent anticancer agent of shikonin derivative targeting tubulin.

In this study, a shikonin ester derivative, compound , was selected to evaluate its anticancer activities and we found that compound exhibited better antitubulin activities against the human HepG2 cell line with an IC50 value of 1.097 µM. Furthermore, the inhibition of tubulin polymerization results indicated that compound demonstrated the most potent antitubulin activity (IC50 = 13.88), which was compared with shikonin and colchicine as positive controls (IC50 = 25.28 µM and 22.56 µM), respectively. Compound was simulated to have good binding site with tubulin and arrested the cell cycle at G2/M phase, which also induces apoptosis in HepG2 cells, in which P53 and members of Bcl-2 protein family were both involved in the progress of apoptosis revealed by western blot. Confocal microscopy observations revealed compound targeted tubulin and altered its polymerization by interfering with microtubule organization. Based on these results, compound functions as a potent anticancer agent targeting tubulin.

[Expression and significance of JNK1, Raf-1 and Livin in the carcinogenesis of sporadic colorectal tubular adenoma].

OBJECTIVE: To study the possible role of JNK1, Raf-1 and Livin in the carcinogenesis of sporadic colorectal tubular adenoma. METHODS: Immunohistochemical staining was used to detect the expression of JNK1, Raf-1 and Livin proteins in 65 sporadic colorectal tubular adenomas with dysplasia of varying degrees and 22 colorectal tubular adenoma with cancerous area. RESULTS: In normal colorectal mucosa, colorectal tubular adenoma with dysplasia and colorectal tubular adenoma with cancerous area, the positive rate of JNK1, Raf-1 and Livin expression was increased gradually. The positive expression of JNK1, Raf-1 and Livin was all significantly higher in the cases of colorectal tubular adenoma with dysplasia or with cancerous area than that in normal colorectal mucosa (P < 0.05), and the positive expression of JNK1, Raf-1 and Livin was significantly higher in colorectal tubular adenoma with cancerous area than that in colorectal tubular adenoma with dysplasia of different degrees (P < 0.05). In the cases of colorectal tubular adenoma with dysplasia of varying degrees, the positive expression of Raf-1 was increased along with the increasing dysplasia degree of colorectal tubular adenoma (P < 0.05). Coexpression of JNK1, Raf-1 and Livin increased gradually in the carcinogenesis of sporadic colorectal tubular adenoma, while positive correlation was found among the expressions of JNK1, Raf-1 and Livin. CONCLUSION: JNK1, Raf-1 and Livin may be involved in the carcinogenesis of sporadic colorectal tubular adenoma.

[Expressions and significance of STAT3 and p38 in the carcinogenesis of sporadic colorectal tubular adenoma].

OBJECTIVE: To investigate the possible role of STAT3 and p38 in the carcinogenesis of sporadic colorectal tubular adenoma. METHODS: The expression of STAT3 and p38 at protein level was studied in 107 sporadic colorectal tubular adenomas with different dysplasia (SCTA-D) or with cancerous changes (SCTA-Ca) by immunohistochemical staining method, meanwhile the expression of STAT3 at mRNA level was detected by in situ hybridization. RESULTS: Immunohistochemical staining results showed that the positive expression rate of STAT3 and p38 was 12.0%, 59.0%, 91.7% and 8.0%, 47.0%, 91.7% in normal colorectal mucosa (NCM), SCTA-D and SCTA-Ca, respectively, with a statistically significant difference of STAT3 and p38 expression among the SCTA-D, SCTA-Ca and NCM (P < 0.05). The expression of STAT3 and p38 was positively correlated with the degree of dysplasia from mild to severe SCTA-D (P < 0.05). In situ hybridization results showed that the positive expression rate of STAT3 at mRNA level in NCM, SCTA-D and SCTA-Ca was 8.00%, 51.8% and 100.0%, respectively, with a statistically significant difference among these either (P < 0.05). The positive expression of STAT3 at mRNA level was not only positively correlated with the degree of dysplasia (P < 0.05), but also with the expression of p38 (P < 0.05). CONCLUSION: STAT3 and p38 may be involved in the carcinogenesis of sporadic colorectal tubular adenoma.