Discovery of the tryptanthrin-derived indoloquinazoline as an anti-breast cancer agent via ERK/JNK activation.

Tryptanthrin, an alkaloid applied in traditional Chinese medicine, exhibits a variety of pharmacological activities. This study aimed to investigate the anti-tumor activity of the tryptanthrin derivative (8-cyanoindolo[2,1-b]quinazoline-6,12-dione [CIQ]) in breast cancer cells. In both MDA-MB-231 and MCF-7 breast cancer cells, CIQ inhibited cell viability and promoted caspase-dependent apoptosis. At the concentration- and time-dependent ways, CIQ increased the levels of p-ERK, p-JNK, and p-p38 in breast cancer cells. We found that exposure to the JNK inhibitor or the ERK inhibitor partially reversed CIQ's viability. We also observed that CIQ increased reactive oxygen species (ROS) generation, and upregulated the phosphorylation and expression of H2AX. However, the pretreatment of the antioxidants did not protect the cells against CIQ's effects on cell viability and apoptosis, which suggested that ROS does not play a major role in the mechanism of action of CIQ. In addition, CIQ inhibited the invasion of MDA-MB-231 cells and decreased the expression of the prometastatic factors (MMP-2 and Snail). These findings demonstrated that the possibility of this compound to show promise in playing an important role against breast cancer.

Extract of Ficus septica modulates apoptosis and migration in human oral squamous cell carcinoma cells.

According to the alarming statistical analysis of global cancer, there are over 19 million new diagnoses and more than 10 million deaths each year. One such cancer is the oral squamous cell carcinoma (OSCC), which requires new therapeutic strategies. Ficus septica extract has been used in traditional medicine to treat infectious diseases. In this study, we examined the anti-proliferative effects of an extract of F. septica bark (FSB) in OSCC cells. Our results showed that FSB caused a concentration-dependent reduction in the viability of SCC2095 OSCC cells, as determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assays, and was less sensitive to fibroblasts. In addition, FSB induced apoptosis by activating caspases, accompanied by the modulation of Akt/mTOR/NF-κB and mitogen-activated protein kinase signaling. Moreover, FSB increased reactive oxygen species generation in a concentration-dependent manner in SCC2095 cells. Furthermore, FSB inhibited cell migration and modulated the levels of the cell adhesion molecules including E-cadherin, N-cadherin, and Snail in SCC2095 cells. Pinoresinol, a lignan isolated from FSB, showed antitumor effects in SCC2095 cells, implying that this compound might play an important role in FSB-induced OSCC cell death. Taken together, FSB is a potential anti-tumor agent against OSCC cells.

NOVEL-1st: an observational study to assess the safety and efficacy of nilotinib in newly diagnosed patients with Philadelphia chromosome-positive chronic myeloid leukemia in chronic phase in Taiwan.

Nilotinib has been approved for the treatment of Philadelphia chromosome-positive chronic myeloid leukemia in chronic phase (Ph+ CML-CP). However, the real-world evidence of nilotinib in newly diagnosed untreated Ph+ CML-CP is limited in Taiwan. The NOVEL-1st study was a non-interventional, multi-center study collecting long-term safety and effectiveness data in patients with newly diagnosed and untreated Ph+ CML-CP receiving nilotinib. We enrolled 129 patients from 11 hospitals. Overall, 1,466 adverse events (AEs) were reported; among these, 151 were serious and 524 were nilotinib-related. Common hematological AEs were thrombocytopenia (31.0%), anemia (20.9%), and leukopenia (14.0%); common nilotinib-related AEs were thrombocytopenia (29.5%), anemia (14.7%), and leukopenia (12.4%). Early molecular response, defined as BCR-ABL ≤ 10% at Month 3, was seen in 87.6% of patients. By 36 months, the cumulative rates of complete hematologic response, complete cytogenetic response, major molecular response, molecular response 4.0-log reduction, and molecular response 4.5-log reduction were 98.5, 92.5, 85.8, 65.0, and 45.0%, respectively. Nilotinib is effective and well-tolerated in patients with newly diagnosed Ph+ CML-CP in the real-world setting. Long-term holistic care and a highly tolerable AE profile may contribute to good treatment outcomes in Ph+ CML-CP under first-line treatment with nilotinib.

Cyclocommunol induces apoptosis in human oral squamous cell carcinoma partially through a Mcl-1-dependent mechanism.

BACKGROUND: Crude extract of breadfruit has been reported to have antitumor activity against various cancer cell lines with unknown mechanism. PURPOSE: This study aims to investigate the proapoptotic effect of cyclocommunol (CYC), a prenylflavonoid from breadfruit, in two oral squamous cell carcinoma (OSCC) cell lines, SCC2095 and Ca922. METHODS: The antiproliferative effects of CYC were assessed by MTT assays and PI/annexin V analysis. SCC2095 cells were transiently transfected with Mcl-1 plasmid in overexpression experiment. Other methods used to investigate the mechanism of CYC included Western blotting, acridine orange staining and confocal microscopic visualization. RESULTS: Our results showed that CYC suppressed the viability of SCC2095 and Ca922 with IC50 values at 48 h of 4.2 and 5.0 µM, respectively. This decrease in viability occurred in a caspase-dependent apoptotic manner. In addition, CYC down-regulated the phosphorylation/expression of Akt/mTOR and Mcl-1, accompanied by reactive oxygen species generation, and autophagy induction. Notably, overexpression of Mcl-1 using Mcl-1-tag-myc partially rescued CYC-mediated caspase-3 activation, PARP cleavage, and cytotoxicity. In summary, our study demonstrated the proapoptotic activity of CYC on OSCC, partially through down-regulation of Mcl-1. CONCLUSION: CYC from breadfruit has translational value as a proapoptotic agent for OSCC.

Identification of a Triterpenoid as a Novel PPARγ Activator Derived from Formosan Plants.

Peroxisome proliferator-activated receptor γ (PPARγ), one of the transcription factors that regulate lipid metabolism and energy use in tumor cells, is a viable target for cancer therapy. In our search for potential PPARγ activator, extracts from five Formosan plants were tested. Among them, Momordica charantia L. showed the highest ability to activate PPARγ, which led us to identify its potential constituents. Among the seven compounds isolated from M. charantia, a triterpenoid, 5ß,19-epoxy-19-methoxycucurbita-6,23-dien-3ß,25-diol (compound 1), was identified as a PPARγ activator with an IC50 of 10 µM in breast cancer MCF-7 cells. Flow cytometric analysis indicated that compound 1 induced G1 cell cycle arrest which might be attributable to the modulation of phosphorylation and expression of numerous key signaling effectors, including cyclin D1, CDK6, and p53. Notably, compound 1 downregulated the expression of histone deacetylase 1, leading to increased histone H3 acetylation. Taken together, these findings suggest that compound 1 may have therapeutic applications in cancer treatment through PPARγ activation. Copyright © 2017 John Wiley & Sons, Ltd.

A Flavone Constituent from Myoporum bontioides Induces M-Phase Cell Cycle Arrest of MCF-7 Breast Cancer Cells.

Myoporum bontioides is a traditional medicinal plant in Asia with various biological activities, including anti-inflammatory and anti-bacterial characteristics. To identify the bioactive constituents from M. bontioides, a newly-identified flavone, 3,4'-dimethoxy-3',5,7-trihydroxyflavone (compound 1), along with eight known compounds, were investigated in human MCF-7 breast cancer, SCC4 oral cancer, and THP-1 monocytic leukemia cells. Among these compounds, compound 1 exhibited the strongest antiproliferative activity with half-maximal inhibitory concentration (IC50) values ranging from 3.3 µM (MCF-7) to 8.6 µM (SCC4). Flow cytometric analysis indicated that compound 1 induced G2/M cell cycle arrest in MCF-7 cells. Mechanistic evidence suggests that the G2/M arrest could be attributable to compound 1's modulatory effects on the phosphorylation and expression of numerous key signaling effectors, including cell division cycle 2 (CDC2), CDC25C, and p53. Notably, compound 1 downregulated the expression of histone deacetylase 2 (HDAC2) and HDAC4, leading to increased histone H3 acetylation and p21 upregulation. Together, these findings suggest the translational potential of compound 1 as a breast cancer treatment.

A triterpenoid from wild bitter gourd inhibits breast cancer cells.

The antitumor activity of 3ß,7ß,25-trihydroxycucurbita-5,23(E)-dien-19-al (TCD), a triterpenoid isolated from wild bitter gourd, in breast cancer cells was investigated. TCD suppressed the proliferation of MCF-7 and MDA-MB-231 breast cancer cells with IC50 values at 72 h of 19 and 23 µM, respectively, via a PPARγ-independent manner. TCD induced cell apoptosis accompanied with pleiotrophic biological modulations including down-regulation of Akt-NF-κB signaling, up-regulation of p38 mitogen-activated protein kinase and p53, increased reactive oxygen species generation, inhibition of histone deacetylases protein expression, and cytoprotective autophagy. Together, these findings provided the translational value of TCD and wild bitter gourd as an antitumor agent for patients with breast cancer.

Anti-tumor activities of triterpenes from Syzygium kusukusense.

In this study, we report the isolation from the stem of Syzygium kusukusense of five triterpenes, 2α-hydroxybetulinic acid (1), betulinic acid (2), platanic acid (3), ursolic acid (4), and hyptatic acid A (5). All were identified for the first time from this indigenous plant of Taiwan. Assessment of the cytotoxic activities of these compounds against a panel of human tumor cell lines, including MCF-7 breast, PC-3 prostate, and SCC2095 oral squamous cell cancers, revealed the high potency of compounds 1 (IC50, 5.7 - 7.6 µM) and, especially, 4 (IC50, 1.7 - 3.7 µM) in suppressing cell viability, which warrants further mechanistic investigations.

Identification of kazinol Q, a natural product from Formosan plants, as an inhibitor of DNA methyltransferase.

DNA methylation plays a pivotal role in the epigenetic regulation of the transcription of a number of cancer-related genes, thereby representing an important target for cancer prevention and treatment. In our search for DNA methyltransferase (DNMT) inhibitors from Formosan plants, by screening against a library consisting of 12 structurally distinct natural products, we identified kazinol Q {4-[6-(1,1-dimethyl-allyl)-7-hydroxy-chroman-2-yl]-3,6-bis-(3-methyl-but-2-enyl)-benzene-1,2-diol} as an inhibitor of recombinant DNMT1 with IC50 of 7 µM. The effect of kazinol Q on DNMT inhibition was validated by its ability to reactivate the expression of a DNA methylation-silenced gene, E-cadherin, in MDA-MB-231 breast cancer cells. Moreover, kazinol Q suppressed the proliferation of MCF-7 breast and LNCaP prostate cancer cells, in part, through apoptosis induction. The role of DNMT1 inhibition in mediating kazinol Q's antiproliferative effect was supported by the protective effect of ectopic expression of DNMT1 on kazinol Q-induced cell death. Molecular modeling analysis suggests that kazinol Q inhibited DNMT activity by competing with cytosine binding, a mechanism similar to that described for (-)-epigallocatechin-3-gallate (EGCG). Relative to EGCG, kazinol Q exhibits several desirable features for drug development, including chemical stability and increased hydrophobicity, and might have therapeutic relevance to cancer treatment.

Cucurbitane Triterpenoid from Momordica charantia Induces Apoptosis and Autophagy in Breast Cancer Cells, in Part, through Peroxisome Proliferator-Activated Receptor γ Activation.

Although the antitumor activity of the crude extract of wild bitter gourd (Momordica charantia L.) has been reported, its bioactive constituents and the underlying mechanism remain undefined. Here, we report that 3 ß ,7 ß -dihydroxy-25-methoxycucurbita-5,23-diene-19-al (DMC), a cucurbitane-type triterpene isolated from wild bitter gourd, induced apoptotic death in breast cancer cells through peroxisome proliferator-activated receptor (PPAR) γ activation. Luciferase reporter assays indicated the ability of DMC to activate PPAR γ , and pharmacological inhibition of PPAR γ protected cells from DMC's antiproliferative effect. Western blot analysis indicated that DMC suppressed the expression of many PPAR γ -targeted signaling effectors, including cyclin D1, CDK6, Bcl-2, XIAP, cyclooxygenase-2, NF- κ B, and estrogen receptor α , and induced endoplasmic reticulum stress, as manifested by the induction of GADD153 and GRP78 expression. Moreover, DMC inhibited mTOR-p70S6K signaling through Akt downregulation and AMPK activation. The ability of DMC to activate AMPK in liver kinase (LK) B1-deficient MDA-MB-231 cells suggests that this activation was independent of LKB1-regulated cellular metabolic status. However, DMC induced a cytoprotective autophagy presumably through mTOR inhibition, which could be overcome by the cotreatment with the autophagy inhibitor chloroquine. Together, the ability of DMC to modulate multiple PPAR γ -targeted signaling pathways provides a mechanistic basis to account for the antitumor activity of wild bitter gourd.

Inhibition of hedgehog signaling induces monocytic differentiation of HL-60 cells.

There is little evidence to demonstrate the importance of the Sonic hedgehog homolog (Shh) pathway to differentiation therapy in the treatment of hematological neoplasms. Here we characterize the changes in acute myelogenous leukemia (HL-60) cells after blocking the Shh pathway by an antagonist of Smoothened, cyclopamine. Cyclopamine induces apoptosis of HL-60 cells in a dose- and time-dependent manner with increased G0/G1 cycle fraction. Treatment with cyclopamine increases the expression of monocytic cell markers CD11b and CD14, but the expression of CD13, CD33 and CD38 is unchanged. The monocytic differentiation of HL-60 cells induced by cyclopamine is also evidenced by an increase in Egr-1 expression. Importantly, cyclopamine down-regulates the phosphorylation of Akt and ERK, but activates AMP-activated protein kinase (AMPK) signaling. Further investigations should determine the clinical application of modulating the Shh pathway in the treatment of hematological malignancies.

OSU-DY7, a novel D-tyrosinol derivative, mediates cytotoxicity in chronic lymphocytic leukaemia and Burkitt lymphoma through p38 mitogen-activated protein kinase pathway.

Drug resistance and associated immune deregulation limit use of current therapies in chronic lymphocytic leukaemia (CLL), thus warranting alternative therapy development. Herein we demonstrate that OSU-DY7, a novel D-tyrosinol derivative targeting p38 mitogen-activated protein kinase (MAPK), mediates cytotoxicity in lymphocytic cell lines representing CLL (MEC-1), acute lymphoblastic leukaemia (697 cells), Burkitt lymphoma (Raji and Ramos) and primary B cells from CLL patients in a dose- and time-dependent manner. The OSU-DY7-induced cytotoxicity is dependent on caspase activation, as evidenced by induction of caspase-3 activation and poly (ADP-ribose) polymerase (PARP) cleavage and rescue of cytotoxicity by Z-VAD-FMK. Interestingly, OSU-DY7-induced cytotoxicity is mediated through activation of p38 MAPK, as evidenced by increased phosphorylation of p38 MAPK and downstream target protein MAPKAPK2. Pretreatment of B-CLL cells with SB202190, a specific p38 MAPK inhibitor, results in decreased MAPKAPK2 protein level with concomitant rescue of the cells from OSU-DY7-mediated cytotoxicity. Furthermore, OSU-DY7-induced cytotoxicity is associated with down regulation of p38 MAPK target BIRC5, that is rescued at protein and mRNA levels by SB202190. This study provides evidence for a role of OSU-DY7 in p38 MAPK activation and BIRC5 down regulation associated with apoptosis in B lymphocytic cells, thus warranting development of this alternative therapy for lymphoid malignancies.

OSU-03012 sensitizes TIB-196 myeloma cells to imatinib mesylate via AMP-activated protein kinase and STAT3 pathways.

Although c-Kit is expressed on the surface of myeloma cells in one-third of myeloma patients, the efficacy of imatinib mesylate for patients with myeloma is still controversial. To investigate the combinatorial effect of OSU-03012 and imatinib mesylate, we treated a c-Kit-expressing myeloma cell line, TIB-196, with DMSO, OSU-03012 alone, imatinib mesylate alone and OSU-03012 plus imatinib mesylate. OSU-03012 sensitized TIB-196 cells to imatinib mesylate cytotoxicity. p-STAT3 (Tyr705), as well as down-stream cyclin D1 and Mcl-1, was down regulated. Additionally, there was markedly increased p-AMPK (Thr172) and down-regulation of p-p70S6K (Thr386) in the combination group. Combined treatments targeting c-Kit, AMPK and STAT3 may be a potential strategy for treating patients with myeloma.