Eliminating cancer stem cells (CSCs) has been suggested for prevention of tumor recurrence and metastasis. Honokiol, an active compound of Magnolia officinalis, had been proposed to be a potential candidate drug for cancer treatment. We explored its effects on the elimination of oral CSCs both in vitro and in vivo. By using the Hoechst side population (SP) technique, CSCs-like SP cells were isolated from human oral squamous cell carcinoma (OSCC) cell lines, SAS and OECM-1. Effects of honokiol on the apoptosis and signaling pathways of SP-derived spheres were examined by Annexin V/Propidium iodide staining and Western blotting, respectively. The in vivo effectiveness was examined by xenograft mouse model and immunohistochemical tissue staining. The SP cells possessed higher stemness marker expression (ABCG2, Ep-CAM, Oct-4 and Nestin), clonogenicity, sphere formation capacity as well as tumorigenicity when compared to the parental cells. Treatment of these SP-derived spheres with honokiol resulted in apoptosis induction via Bax/Bcl-2 and caspase-3-dependent pathway. This apoptosis induction was associated with marked suppression of JAK2/STAT3, Akt and Erk signaling pathways in honokiol-treated SAS spheres. Consistent with its effect on JAK2/STAT3 suppression, honokiol also markedly inhibited IL-6-mediated migration of SAS cells. Accordingly, honokiol dose-dependently inhibited the growth of SAS SP xenograft and markedly reduced the immunohistochemical staining of PCNA and endothelial marker CD31 in the xenograft tumor. Honokiol suppressed the sphere formation and xenograft growth of oral CSC-like cells in association with apoptosis induction and inhibition of survival/proliferation signaling pathways as well as angiogenesis. These results suggest its potential as an integrative medicine for combating oral cancer through targeting on CSCs.

Malignant glioma (MG) is a poor prognostic brain tumor with inevitable recurrence after multimodality treatment. Searching for more effective treatment is urgently needed. Differentiation induction via epigenetic modification has been proposed as a potential anticancer strategy. Natural products are known as fruitful sources of epigenetic modifiers with wide safety margins. We thus explored the effects of oligo-fucoidan (OF) from brown seaweed on this notion in MG cells including Grade III U87MG cells and Grade IV glioblastoma multiforme (GBM)8401 cells and compared to the immortalized astrocyte SVGp12 cells. The results showed that OF markedly suppress the proliferation of MG cells and only slightly affected that of SVGp12 cells. OF inhibited the protein expressions of DNA methyltransferases 1, 3A and 3B (DNMT1, 3A and 3B) accompanied with obvious mRNA induction of differentiation markers (MBP, OLIG2, S100β, GFAP, NeuN and MAP2) both in U87MG and GBM8401 cells. Accordingly, the methylation of p21, a DNMT3B target gene, was decreased by OF. In combination with the clinical DNMT inhibitor decitabine, OF could synergize the growth inhibition and MBP induction in U87MG cells. Appropriated clinical trials are warranted to evaluate this potential complementary approach for MG therapy after confirmation of the effects in vivo.

Non-small cell lung cancer (NSCLC)-carrying specific epidermal growth factor receptor (EGFR) mutations can be effectively treated by a tyrosine kinase inhibitor such as gefitinib. However, the inevitable development of acquired resistance leads to the eventual failure of therapy. In this study, we show the combination effect of omega-3 fatty acid-enriched fish oil (FO) and selenium (Se) on reversing the acquired gefitinib-resistance of HCC827 NSCLC cells. The gefitinib-resistant subline HCC827GR possesses lowered proapoptotic CHOP (CCAAT/enhancer-binding protein homologous protein) and elevated cytoprotective GRP78 (glucose regulated protein of a 78 kDa molecular weight) endoplasmic reticulum (ER) stress response elements, and it has elevated β-catenin and cyclooxygenase-2 (COX-2) levels. Combining FO and Se counteracts the above features of HCC827GR cells, accompanied by the suppression of their raised epithelial-to-mesenchymal transition (EMT) and cancer stem markers, such as vimentin, AXL, N-cadherin, CD133, CD44, and ABCG2. Accordingly, an FO and Se combination augments the gefitinib-mediated growth inhibition and apoptosis of HCC827GR cells, along with the enhanced activation of caspase -3, -9, and ER stress-related caspase-4. Intriguingly, gefitinib further increases the elevated ABCG2 and cancer stem-like side population in HCC827GR cells, which can also be diminished by the FO and Se combination. The results suggest the potential of combining FO and Se in relieving the acquired resistance of NSCLC patients to targeted therapy.

Radiotherapy for treatment of hepatocellular carcinoma causes severe side effects, including acute hepatitis and chronic fibrosis. Complementary and alternative medicine (CAM) has emerged as an important part of integrative medicine in the management of diseases. Antrodia cinnamomea (AC), a valuable medicinal fungus originally found only in Taiwan, has been shown to possess anti-oxidation, vaso-relaxtation, anti-inflammation, anti-hepatitis, and anti-cancer effects. In this paper we evaluate the protective effects of ethanol extract of Antrodia cinnamomea (ACE) against radiotoxicity both in normal liver cell line CL48 and in tumor-bearing mice. In CL48, ACE protects cells by eliminating irradiation-induced reactive oxygen species (ROS) through the induction of Nrf2 and the downstream redox system enzymes. The protective effect of ACE was also demonstrated in tumor-bearing mice by alleviating irradiation-induced acute hepatitis. ACE could also protect mice from CCl₄-induced hepatitis. Since both radiation and CCl₄ cause free radicals, these results indicate that ACE likely contains active components that protect normal liver cells from free radical attack and can potentially benefit hepatocellular carcinoma (HCC) patients during radiotherapy.

The non-small cell lung cancer (NSCLC) is the leading cause of cancer death worldwide. In NSCLC, the oncogenic AKT-mTOR, ERK and STAT3 pathways are commonly dysregulated and have emerged as attractive targets for therapeutic developments. In a relatively limited subset of NSCLC, these pathways driven by mutant EGFR can be treated by the tyrosine kinase inhibitors (TKIs)-mediated targeted therapy. However, for the most NSCLC, more novel targeted agents are imperatively needed. Therefore, we investigated the inhibitory effects of the active fraction HS7 from Taiwanofungus camphoratus, a unique medicinal fungus in Taiwan, on these pathways in CL1-0 EGFR wild-type human NSCLC cells. The active fraction HS7 was prepared by n-hexane extraction of T. camphoratus followed by silica gel chromatography. Its effects on the cell viabilities were determined by sulforhodamine B colorimetric assay. Flow cytometry was used to analyze cell-cycle regulation and apoptosis induction. The changes in cellular protein levels were examined by Western blot. The active fraction HS7 vigorously inhibits AKT-mTOR, ERK and STAT3 signaling pathways in CL1-0 cells. At dose of 25 μg/mL, these signaling pathways were almost completely inhibited by HS7, accompanied with induction of cyclin-dependent kinase inhibitors such as p15, p21 and p27. Accordingly, the AKT-mTOR downstream targets p-p70S6K and HIF-1α were also suppressed as well. At this dose, the cell proliferation was profoundly suppressed to 23.4% of control and apoptosis induction was observed. The active fraction HS7 from n-hexane extract of T. camphoratus exerts multi-targeting activity on the suppression of AKT-mTOR, ERK and STAT3 pathways and induction of p15, p21 and p27 in EGFR wild-type NSCLC cells. This multi-targeting activity of HS7 suggests its potential as an alternative medicine for the treatment of EGFR TKIs resistant NSCLC.

Lung cancer is the leading cause of cancer death worldwide; the most common pathologic type is lung adenocarcinoma (LADC). In spite of the recent progress in targeted therapy, most LADC patients eventually expired due to the inevitable recurrence and drug resistance. New complementary agent with evidence‐based molecular mechanism is urgently needed. MiR‐34a is an important p53 downstream tumor suppressor, which regulates apoptosis, cell‐cycle, EMT (epithelial mesenchymal transition), and so forth. Its expression is deficient in many types of cancers including LADC. Here, we show that a Chinese herbal formula JP‐1 activates p53/miR‐34a axis in A549 human LADC cells (p53 wild‐type). Treatment with JP‐1 induces p53 and its downstream p21 and BAX proteins as well as the miR‐34a, resulting in growth inhibition, colony formation reduction, migration repression, and apoptosis induction. Accordingly, the decreases of miR‐34a downstream targets such as CDK6, SIRT1, c‐Myc, survivin, Snail, and AXL were observed. Moreover, JP‐1 activates AMPKα and reduces mTOR activity, implying its inhibitory effect on the energy‐sensitive protein synthesis and cell proliferation signaling. Our results show that JP‐1 activates p53/miR‐34a tumor suppressor axis and decreases proteins related to proliferation, apoptosis resistance, and metastasis, suggesting its potential as a complementary medicine for LADC treatment.