Sodium Danshensu Inhibits Oral Cancer Cell Migration and Invasion by Modulating p38 Signaling Pathway.

Background: Oral squamous cell carcinoma (OSCC) that comprises about 90% of all oral cancer cases is associated with poor prognosis due to its highly metastatic nature. The majority of OSCC treatment options are related detrimental side-effects. Hypothesis/Purpose: The present study aimed at deciphering the effects of a bioactive phytochemical, sodium danshensu, on human oral cancer cell metastasis. Methods and Results: The treatment of FaDu and Ca9-22 cells with different doses of sodium danshensu (25, 50, and 100 µM) caused a significant reduction in cellular motility, migration, and invasion, as compared to the untreated cells. This effect was associated with a reduced expression of MMP-2, vimentin and N-cadherin, together with an enhanced expression of E-cadherin and ZO-1. Further investigation on the molecular mechanism revealed that treatment with sodium danshensu caused significant reduction in p38 phosphorylation; however, phosphorylation of ERK1/2 significantly decreased only in FaDu cells, whereas p-JNK1/2 did not show any alteration. A combination of p38 and JNK1/2 inhibitors with sodium danshensu also reduced the migration in the FaDu and Ca9-22 cell lines. Conclusion: Collectively, the present study findings reveal that sodium danshensu execute anti-metastatic effect by suppressing p38 phosphorylation in human oral cancer. The study identifies sodium danshensu as a potential natural anticancer agent that can be used therapeutically to manage highly metastatic OSCC.

GLUT5-mediated fructose utilization drives lung cancer growth by stimulating fatty acid synthesis and AMPK/mTORC1 signaling.

Lung cancer (LC) is a leading cause of cancer-related deaths worldwide. Its rapid growth requires hyperactive catabolism of principal metabolic fuels. It is unclear whether fructose, an abundant sugar in current diets, is essential for LC. We demonstrated that, under the condition of coexistence of metabolic fuels in the body, fructose was readily used by LC cells in vivo as a glucose alternative via upregulating GLUT5, a major fructose transporter encoded by solute carrier family 2 member 5 (SLC2A5). Metabolomic profiling coupled with isotope tracing demonstrated that incorporated fructose was catabolized to fuel fatty acid synthesis and palmitoleic acid generation in particular to expedite LC growth in vivo. Both in vitro and in vivo supplement of palmitoleic acid could restore impaired LC propagation caused by SLC2A5 deletion. Furthermore, molecular mechanism investigation revealed that GLUT5-mediated fructose utilization was required to suppress AMPK and consequently activate mTORC1 activity to promote LC growth. As such, pharmacological blockade of in vivo fructose utilization using a GLUT5 inhibitor remarkably curtailed LC growth. Together, this study underscores the importance of in vivo fructose utilization mediated by GLUT5 in governing LC growth and highlights a promising strategy to treat LC by targeting GLUT5 to eliminate those fructose-addicted neoplastic cells.

Effects of diphyllin as a novel V-ATPase inhibitor on TE-1 and ECA-109 cells.

Diphyllin is a natural component of traditional Chinese medicine, which effectively inhibits V-ATPase activity and affects the progression of cancer. However, few studies have been conducted on esophageal cancer, and the mechanisms remain to be elucidated. The present study revealedthat diphyllin inhibited proliferation and induced S arrest in esophageal cancer cell lines TE-1 and ECA-109. Further experiments revealed that diphyllin inhibited V-ATPase activity and decreased the mRNA expression of mammalian target of rapamycin complex 1 (mTORC1), hypoxia-inducible factor-1α (HIF-1α), and vascular endothelial growth factor (VEGF). The present study also revealed that diphyllin inhibited proliferation and reduced the formation of new blood vessels. Diphyllin inhibited blood metastasis by regulating the mTORC1/HIF-1α-/VEGF pathway, therefore it could be considered as a new V-ATPase inhibitor to treat esophageal cancer.

Methionine Aminopeptidase 2 as a Potential Therapeutic Target for Human Non-Small-Cell Lung Cancers.

BACKGROUND: Methionine aminopeptidase 2 (MetAP2) is a bi-functional protein that plays a critical role in the regulation of post-translational processing and protein synthesis. OBJECTIVES: We studied whether MetAP2 is activated and expressed in human non-small-cell lung cancer (NSCLC) tissues and whether inactivation of MetAP2 activity, with its specific inhibitor fumagillin, potentially inhibits proliferation of NSCLC cells. MATERIAL AND METHODS: The expression and function of MetAP2 were evaluated in NSCLC tissues, primary cell cultures and cell lines using immunohistochemistry, RT-PCR, Western blot, aminopeptidase activity assay and flow cytometry. MetAP2 expression was also studied in relation to clinicopathological factors. RESULTS: MetAP2 expression in NSCLS, including adenocarcinoma (ADC) and squamous cell carcinoma (SCC), showed a moderate to strong positive reaction while normal appearing bronchial epithelium showed weak staining and normal alveolar epithelial cells were widely negative. A high MetAP2 mRNA and protein expression was found in NSCLC tissues. The aminopeptidase activity in NSCLC was 2-fold higher than that in normal lung tissues. In a series of 41 ADC patients, MetAP2 expression was significantly correlated with patient's outcome or survival time. Inhibition of MetAP2 by fumagillin in SCC cell lines revealed a significant increase in caspase-3 activity as compared to the control (p = 0.001). CONCLUSIONS: Our results indicate that MetAP2 is involved in NSCLC and is an important regulator of proliferative and apoptotic targets. Thus inhibition of MetAP2, such as by fumagillin, may be a potential therapeutic modality for prevention of tumor cell growth, development and progression in NSCLC patients.

Akt Signal Transduction Pathways and Nuclear Factor-kappa B (NF-κB) Transcription as a Molecular Target of Oral Tongue Squamous Cell Carcinoma (SP-C1) Using Papua's Anthill Plant ( Myrmecodia pendans ).

BACKGROUND AND OBJECTIVE: Squamous cell carcinoma is a malignant tumor derived from epithelial tissue with cell structure group, capable to infiltrate through the bloodstream and lymphatic tissue, spreading throughout the body. This study aim to complete theoretical foundation of flavonoid compound from anthill plant (Myrmecodia pendans) which contribute in growing cell line oral tongue squamous cell carcinoma through proliferation inhibition, inhibition mechanism transduction Akt signal and NF-κB in tongue cancer cell Supri's-clone (SP-C1). Application benefit to explore potential fractionation anthill plant use herbal ingredients for chemo protective therapy. MATERIALS AND METHODS: This whole study conducted with experiment laboratorium method utilized tongue cancer human cell SP-C1. This study consist 2 steps, first to determinate, extraction and fractionation anthill plant and carry out tonicity test to get flavonoid fraction from anthill plant which has anticancer potential against tongue cancer cell SP-C1. The second stage held with invasion inhibition test, proliferation and inhibition test against protein Akt expression and NF-κB in tongue cancer cell SP-C1. The barriers to proliferation through the test of MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] assay, barriers to invasion through Boyden chamber assay and the membrane polycarbonate, ELISA analysis and Western blotting analysis on the obstacle Akt signal transduction pathways and transcription factor of nuclear factor-kappa B (NF-κB). Data analysis conducted with 2 way ANOVA followed with LSD post hoc test with significance is set on 95%. Pearson correlation conduct to find strong relationship intervariable. RESULTS: This study showed that the average cell growth inhibition SP-C1 based on the time and concentration using the MTT [3-(4,5- dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] assay. The resistance of cancer cell in vitro SP-C1. On ELISA testing and Western blotting analysis, inhibiton of protein expression of Akt signal transduction and transcription factor of nuclear factor-kappa B (NF-κB) showed increased protein expression was significantly obstacles and prove that the ethyl acetate fraction flavonoid inhibits translocation and activation of transcription pathway NF-κB and growth factors that induces the phosphorylation of Akt signal transduction pathway. CONCLUSION: Ethyl acetate fraction flavonoid anthill has antitumor activity in multiple molecular targets transduction pathway including Akt and nuclear factor-kappa B (NF-κB) squamous cell carcinoma of the tongue.

Impaired aldehyde dehydrogenase 1 subfamily member 2A-dependent retinoic acid signaling is related with a mesenchymal-like phenotype and an unfavorable prognosis of head and neck squamous cell carcinoma.

BACKGROUND: An inverse correlation between expression of the aldehyde dehydrogenase 1 subfamily A2 (ALDH1A2) and gene promoter methylation has been identified as a common feature of oropharyngeal squamous cell carcinoma (OPSCC). Moreover, low ALDH1A2 expression was associated with an unfavorable prognosis of OPSCC patients, however the causal link between reduced ALDH1A2 function and treatment failure has not been addressed so far. METHODS: Serial sections from tissue microarrays of patients with primary OPSCC (n = 101) were stained by immunohistochemistry for key regulators of retinoic acid (RA) signaling, including ALDH1A2. Survival with respect to these regulators was investigated by univariate Kaplan-Meier analysis and multivariate Cox regression proportional hazard models. The impact of ALDH1A2-RAR signaling on tumor-relevant processes was addressed in established tumor cell lines and in an orthotopic mouse xenograft model. RESULTS: Immunohistochemical analysis showed an improved prognosis of ALDH1A2(high) OPSCC only in the presence of CRABP2, an intracellular RA transporter. Moreover, an ALDH1A2(high)CRABP2(high) staining pattern served as an independent predictor for progression-free (HR: 0.395, p = 0.007) and overall survival (HR: 0.303, p = 0.002), suggesting a critical impact of RA metabolism and signaling on clinical outcome. Functionally, ALDH1A2 expression and activity in tumor cell lines were related to RA levels. While administration of retinoids inhibited clonogenic growth and proliferation, the pharmacological inhibition of ALDH1A2-RAR signaling resulted in loss of cell-cell adhesion and a mesenchymal-like phenotype. Xenograft tumors derived from FaDu cells with stable silencing of ALDH1A2 and primary tumors from OPSCC patients with low ALDH1A2 expression exhibited a mesenchymal-like phenotype characterized by vimentin expression. CONCLUSIONS: This study has unraveled a critical role of ALDH1A2-RAR signaling in the pathogenesis of head and neck cancer and our data implicate that patients with ALDH1A2(low) tumors might benefit from adjuvant treatment with retinoids.

Anticancer Effect of Ursodeoxycholic Acid in Human Oral Squamous Carcinoma HSC-3 Cells through the Caspases.

Bear bile was used as a traditional medicine or tonic in East Asia, and ursodeoxycholic acid (UDCA) is the most important compound in bear bile. Further, synthetic UDCA is also used in modern medicine and nutrition; therefore, its further functional effects warrant research, in vitro methods could be used for the fundamental research of its anticancer effects. In this study, the apoptotic effects of UDCA in human oral squamous carcinoma HSC-3 cells through the activation of caspases were observed by the experimental methods of MTT (3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide) assay, DAPI (4',6-diamidino-2-phenylindole) staining, flow cytometry analysis, RT-PCR (reverse transcription-polymerase chain reaction) assay and Western blot assay after HSC-3 cells were treated by different concentrations of UDCA. With 0 to 400 µg/mL UDCA treatment, UDCA had strong growth inhibitory effects in HSC-3 cells, but had almost no effect in HOK normal oral cells. At concentrations of 100, 200 and 400 µg/mL, UDCA could induce apoptosis compared to untreated control HSC-3 cells. Treatment of 400 µg/mL UDCA could induce more apoptotic cancer cells than 100 and 200 µg/mL treatment; the sub-G1 DNA content of 400 µg/mL UDCA treated cancer cells was 41.3% versus 10.6% (100 µg/mL) and 22.4% (200 µg/mL). After different concentrations of UDCA treatment, the mRNA and protein expressions of caspase-3, caspase-8, caspase-9, Bax, Fas/FasL (Fas ligand), TRAIL (TNF-related apoptosis-inducing ligand), DR4 (death receptor 4) and DR5 (death receptor 5) were increased in HSC-3 cells, and mRNA and protein expressions of Bcl-2 (B-cell lymphoma 2), Bcl-xL (B-cell lymphoma-extra large), XIAP (X-linked inhibitor of apoptosis protein), cIAP-1 (cellular inhibitor of apoptosis 1), cIAP-2 (cellular inhibitor of apoptosis 2) and survival were decreased. Meanwhile, at the highest concentration of 400 µg/mL, caspase-3, caspase-8, caspase-9, Bax, Fas/FasL, TRAIL, DR4, DR5, and IκB-α expression levels were the highest, and Bcl-2, Bcl-xL, XIAP, cIAP-1, cIAP-2, survival, and NF-κB expression levels were the lowest. These results proved that UDCA could induce apoptosis of HSC-3 cancer cells through caspase activation, and the higher concentration of UDCA had stronger effects in vitro. UDCA might be a good nutrient for oral cancer prevention.

Fructus phyllanthi tannin fraction induces apoptosis and inhibits migration and invasion of human lung squamous carcinoma cells in vitro via MAPK/MMP pathways.

AIM: Fructus phyllanthi tannin fraction (PTF) from the traditional Tibetan medicine Fructus phyllanthi has been found to inhibit lung and liver carcinoma in mice. In this study we investigated the anticancer mechanisms of PTF in human lung squamous carcinoma cells in vitro. METHODS: Human lung squamous carcinoma cell line (NCI-H1703), human large-cell lung cancer cell line (NCI-H460), human lung adenocarcinoma cell line (A549) and human fibrosarcoma cell line (HT1080) were tested. Cell viability was detected with MTT assay. Cell migration and invasion were assessed using a wound healing assay and a transwell chemotaxis chambers assay, respectively. Cell apoptosis was analyzed with flow cytometric analysis. The levels of apoptosis-related and metastasis-related proteins were detected by Western blot and immunofluorescence. RESULTS: PTF dose-dependently inhibited the viability of the 3 human lung cancer cells. The IC50 values of PTF in inhibition of NCI-H1703, NCI-H460, and A549 cells were 33, 203, and 94 mg/L, respectively. PTF (15, 30, and 60 mg/L) dose-dependently induced apoptosis of NCI-H1703 cells. Treatment of NCI-H1703 and HT1080 cells with PTF significantly inhibited cell migration, and reduced the number of invasive cells through Matrigel. Furthermore, PTF dose-dependently down-regulated the expression of phosphor-ERK1/2, MMP-2 and MMP-9, up-regulated the expression of phosphor-JNK, but had no significant effect on the expression of ERK1/2 or JNK. CONCLUSION: PTF induces cell apoptosis and inhibits the migration and invasion of NCI-H1703 cells by decreasing MPPs expression through regulation of the MAPK pathway.

Riboflavin as adjuvant with cisplatin: study in mouse skin cancer model.

Cisplatin used in treatment of solid tumor induces oxidative stress which leads to hepatotoxicity and nephrotoxicity. New strategies are therefore needed to combat toxicity and optimize its therapeutic potential. Riboflavin (VitaminB2) under photoillumination works as an anti proliferative agent and induces apoptosis. These properties of riboflavin have been exploited to mitigate cisplatin induced toxicities. 9,10-dimethylbenz(a)anthracene /12-O-tetradecanoylphorbol-13-acetate  were used to induce skin tumor in Swiss albino mice. The tumor induced mice were treated with cisplatin, riboflavin as well as their combination under photo illumination. In comparison to tumor control group the cisplatin and riboflavin treated groups showed a compromised level of antioxidant enzymes, functional markers and a higher degree of lipid peroxidation. However these parameters tended towards normal in the combination treated group. The results from histopathology indicate that apoptosis was favored mode of cell death and that necrosis was reduced in combination treated groups. Our findings indicate that combination of cisplatin with riboflavin under photo illumination synergizes its anti cancer activity towards cancer cells and attenuates the cisplatin induced toxicities.

Down-regulation of Akt by methanol extracts of Impatiens balsamina L. promotes apoptosis in human oral squamous cell carcinoma cell lines.

BACKGROUND: The apoptotic activity of methanol extracts of Impatiens balsamina L. (MEIB) and related mechanisms in human oral squamous cell carcinoma (OSCC) cells have been systematically investigated. METHODS: The effects of MEIB on human OSCC cell lines were investigated using trypan blue exclusion assay, MTS assay, Western blot, 4'-6-diamidino-2-phenylindole (DAPI) staining, Live/Dead assay, Immunohistochemistry, reverse transcription-polymerase chain reaction, and promoter assay. RESULTS: MEIB decreased cell viability and induced apoptosis in HSC-4 cells. Higher levels of p-Akt expression were observed in OSCC than in normal oral mucosa (NOM), and it correlated with poor survival of the patients. MEIB dephosphorylated p-Akt and decreased Akt expression through proteasome-dependent degradation. LY294002 (PI3K inhibitor) decreased p-Akt and Akt, resulting in enhancing MEIB-induced apoptosis. MEIB down-regulated the expression level of survivin protein at the transcriptional level and YM155 (survivin inhibitor) decreased survivin, which facilitated MEIB-induced apoptosis. MEIB and LY294002 significantly increased Bax, thereby inducing the conformational change, mitochondrial translocation, and oligomerization. In addition, MEIB-induced growth inhibition and apoptosis in OSC-20, another human OSCC cells were mediated by regulating Akt and it downstream targets, survivin and Bax. CONCLUSIONS: These results suggest that MEIB may serve as a potential drug candidate for the treatment of human OSCC.

Comprehensive evaluation of caspase-14 in vulvar neoplasia: an opportunity for treatment with black raspberry extract.

OBJECTIVE: The aim of this study is to determine the expression of caspase-14, a key protein in maturation of squamous epithelia, in archival malignant and premalignant vulvar squamous lesions and examine in-vitro effects of a black raspberry extract (BRB-E) on a vulvar squamous cell carcinoma (VSCC) cell line. METHODS: VSCC cell cultures were exposed to different BRB-E concentrations and used to create cell blocks. Immunohistochemistry for caspase-14 was performed on cell block sections, whole tissue sections, and a tissue microarray consisting of normal vulvar skin, lichen sclerosus (LS), classic and differentiated vulvar intraepithelial neoplasia (cVIN and dVIN respectively), and VSCC. RESULTS: LS demonstrated abnormal full thickness (5/11) or absent (1/11) caspase-14 staining. dVIN often showed markedly reduced expression (4/7), and cVIN occasionally demonstrated either absent or reduced caspase-14 (6/22). VSCC predominantly had absent or markedly reduced caspase-14 (26/28). VSCC cell cultures demonstrated a significant increase in caspase-14 (p=0.013) after BRB-E treatment: 7.3% (±2.0%) of untreated cells showed caspase-14 positivity, while 21.3% (±8.9%), 21.7% (±4.8%), and 22.6% (±5.3%) of cells were positive for caspase-14 after treatment with 200, 400, and 800 µg/mL BRB-E, respectively. Pair-wise comparisons between the treatment groups and the control demonstrated significant differences between no treatment with BRB-E and each of these treatment concentrations (Dunnett's adjusted p-values: 0.024, 0.021, and 0.014, respectively). CONCLUSIONS: Caspase-14 is frequently decreased in premalignant and malignant vulvar squamous lesions, and is upregulated in VSCC cell culture by BRB-E. BRB-E should be further explored and may ultimately be incorporated in topical preparations.

Anti-proliferative and apoptotic activities of constituents of chloroform extract of Juglans regia leaves.

OBJECTIVES: To evaluate anti-proliferative as well as apoptotic activities of compounds identified in chloroform extract of Juglans regia leaves, on human breast and oral cancer cell lines (MCF-7 and BHY). MATERIALS AND METHODS: Column chromatography, MTT assay, flowcytometry and western blotting have all been used in the study. RESULTS: Bioassay-guided fractionation of chloroform extract of J. regia afforded isolation of 5-hydroxy-3,7,4'-trimethoxyflavone [1], lupeol [2], daucosterol [3], 4-hydroxy-α-tetralone [4], ß-sitosterol [5], 5,7- dihydroxy-3,4'-dimethoxyflavone [6] and regiolone [7]. Structures of the compounds were established on the basis of spectroscopic analyses [Nuclear magnetic resonance (NMR) and mass]. All compounds inhibited proliferation of MCF-7 (human breast adenocarcinoma) and BHY (human oral squamous carcinoma) cells in a concentration-dependent manner. Compounds 6 and 7 had potent cytotoxic effects on both MCF-7 and BHY cells (IC50 21-51 µm), yet were not toxic to normal cells. MCF-7 growth inhibition was attributed to apoptosis; population of apoptotic cells increased from 1.12% in controls to 5.64 and 8.1% after 48-h treatment with compounds 6 and 7, indicating their potential at inducing early and late apoptosis. The caspase cascade was not activated, as indicated by only insignificant cleavage of caspase-3. CONCLUSIONS: Our results suggest that compounds 6 and 7 can induce apoptosis in MCF-7 cells through the caspase-3 independent pathway.

Increase of phosphatase and tensin homolog by silymarin to inhibit human pharynx squamous cancer.

Silymarin is an active principle from the seeds of the milk thistle plant and is widely used as a hepatoprotective gent due to its antioxidant-like activity. In the present study, we evaluated the potential efficacy of silymarin against oral cancer and investigated its possible mechanism of action. Cell viability assay and western blotting analyses were used to identify silymarin-induced apoptotic cell death in human pharynx squamous cell carcinoma (FaDu) cells. The short interfering RNA (siRNA) is used to confirm the role of phosphatase and tensin homolog (PTEN) in silymarin-induced apoptosis. Treatment of FaDu cells with silymarin resulted in a significant decrease in cell viability (up to 70%). Silymarin inhibited the phosphorylation of Akt (over 10-fold) with an increase in expression of PTEN (five to sixfold). Consequently, the level of Bcl-2 expression was decreased five to sixfold and caspase 3 activated to induce apoptosis. Treatment with siRNA specific to PTEN gene diminished the action of silymarin. The results suggest that silymarin inhibits the Akt signaling pathway by increasing PTEN expression in FaDu cells and directly affects Bcl-2 family members. Also, we demonstrated the inhibitory activity of silymarin for oral cancer is related to cell survival. These mechanisms may in part explain the actions of silymarin and provide a rationale for the development of silymarin as an anticancer agent.

Upregulation of Ying Yang 1 (YY1) suppresses esophageal squamous cell carcinoma development through heme oxygenase-1.

Esophageal squamous cell carcinoma (ESCC) is one of the deadliest malignancies worldwide. Ying Yang 1 (YY1), a ubiquitously expressed GLI-Krüppel zinc finger transcription factor, plays a regulatory role in a variety of fundamental biological processes, such as embryonic development, growth, apoptosis, differentiation and oncogenic transformation. The purpose of this study was to investigate the expression of YY1 in normal and cancerous esophageal tissues and its function in ESCC development. We found that the expression of YY1 mRNA was significantly increased in the tumor tissues, compared with the para-tissues or normal esophageal tissues. The increased expression of YY1 in tumor samples was further confirmed by immunohistochemistry. Furthermore, the overexpression of YY1 conferred radioresistance to the ESCC TE-1 cells and resulted in markedly reduced cell proliferation. Accordingly, the small interfering RNA-mediated silencing of YY1 expression in TE-1 cells resulted in increased proliferation by enhancing the binding of P21 to Cyclin D1 and CDK4, a protein complex known to mediate cell cycle progression. Moreover, besides P21, heme oxygenase-1 (HO-1) was identified as a YY1 downstream effector, as YY1 stimulated HO-1 expression in esophageal cancer cells. YY1 mediated biological function through transcription of HO-1. Forced expression of HO-1 could moderately suppress proliferation of TE-1 cells. The expression of YY1 significantly correlated with that of HO-1 in ESCC tissues. Taken together, we demonstrated overexpression of YY1 in esophageal carcinoma and identified HO-1 as its target.

Bidirectional regulation of manganese superoxide dismutase (MnSOD) on the radiosensitivity of esophageal cancer cells.

The mitochondrial antioxidant protein manganese superoxide dismutase (MnSOD) may represent a new type of tumor suppressor protein. Overexpression of the cDNA of this gene by plasmid or recombinant lentiviral transfection in various types of cancer leads to growth suppression both in vitro and in vivo. We previously determined that changes in MnSOD expression had bidirectional effects on adriamycin (ADR) when combined with nitric oxide (NO). Radiation induces free radicals in a manner similar to ADR, so we speculated that MnSOD combined with NO would also have a bidirectional effect on cellular radiosensitivity. To examine this hypothesis, TE-1 human esophageal squamous carcinoma cells were stably transfected using lipofectamine with a pLenti6-DEST plasmid containing human MnSOD cDNA at moderate to high overexpression levels or with no MnSOD insert. Blastidicin-resistant colonies were isolated, grown, and maintained in culture. We found that moderate overexpression of MnSOD decreased growth rates, plating efficiency, and increased apoptosis. However, high overexpression increased growth rates, plating efficiency, and decreased apoptosis. When combined with NO, moderate overexpression of MnSOD increased the radiosensitivity of esophageal cancer cells, whereas high MnSOD overexpression had the opposite effect. This finding suggests a potential new method to kill certain radioresistant tumors and to provide radioresistance to normal cells.

The root bark of Paeonia moutan is a potential anticancer agent in human oral squamous cell carcinoma cells.

Currently there is growing use of complementary and alternative anticancer medicines worldwide, and considerable interest in finding anticancer drugs among Chinese medicinal herbs. The aim of this study was to determine the antitumor activity of the root bark of Paeonia moutan (RBPM) in human squamous cell carcinoma (OSCC) cells. Cell lines derived from human oral squamous cell carcinoma (HSC2, 3, 4, SAS) were tested with different concentrations of RBPM (1-100 µg/ml) using a series of in vitro assay systems. RBPM at a concentration of 100 µg/ml inhibited monolayer and anchorage-independent growth, and interrupted coordinated migration. RBPM activated the phosphorylation of extracellular signal-regulated kinase (ERK) and serine/threonine kinase AKT in 30 min; then, at a later stage (after 6 hours) exhibited potent cytostatic, pro-apoptotic effects through the down-regulation of the expression of cyclin-dependent kinase 4 and its partner cyclin D1, and poly(ADP-ribose) polymerase cleavage. We found direct evidence that RBPM induces apoptotic cell death via DNA fragmentation. Taken together, the antitumor activity of RBPM was demonstrated through antiproliferative and apoptotic effects.

Selective apoptotic effect of Zelkova serrata twig extract on mouth epidermoid carcinoma through p53 activation.

Apoptosis or programmed cell death plays an essential role in chemotherapy-induced tumor cell killing, and inducers of apoptosis are commonly used in cancer therapy. Treatment with Zelkova serrata extracts was performed in human gingival fibroblast (HGF), mouth epidermoid carcinoma cell (KB), lower gingival squamous cancer cell (YD38) and tongue mucoepidermoid carcinoma cells (YD15). We observed that extract prepared from Zelkova serrata twig selectively inhibited proliferation of various oral cancer cells, but not normal gingival fibroblasts, in a dose-dependent manner. Caspase-8-mediated apoptosis was induced by treatment with the extract only in mouth epidermoid carcinoma and not in other types of cancer cells, including lower gingival squamous cell carcinoma. The selective apoptotic effect of Zelkova serrata twig extract in mouth epidermoid carcinoma was dependent on normal p53 status. Apoptosis was not remarkably induced by treatment with the extract in either lower gingival squamous or tongue mucoepidermoid carcinoma cells, both of which contain abnormalities of p53. Upon treatment with Zelkova serrata twig extract, mouth epidermoid carcinoma cells accumulated in S phase by activation of p21. These data indicate that Zelkova serrata twig extract exerted a cancer type-specific, p53-dependent apoptotic effect and disturbed the cell cycle, which suggests that herbal medicine could be a treatment for specific types of cancers.

Curcumin treatment suppresses IKKß kinase activity of salivary cells of patients with head and neck cancer: a pilot study.

PURPOSE: To determine whether curcumin would inhibit IκB kinase ß (IKKß) kinase activity and suppress expression of proinflammatory cytokines in head and neck squamous cell carcinoma cancer (HNSCC) patients. EXPERIMENTAL DESIGN: Saliva was collected before and after subjects chewed curcumin tablets. Protein was extracted and IKKß kinase activity measured. Interleukin (IL)-6 and IL-8 levels in the salivary supernatants were measured by ELISA. IL-6, IL-8, and other interleukin were also measured independently with ELISA to confirm the inhibitory effect of curcumin on expression and secretion of salivary cytokines. RESULTS: Curcumin treatment led to a reduction in IKKß kinase activity in the salivary cells of HNSCC patients (P < 0.05). Treatment of UM-SCC1 cells with curcumin as well as with post-curcumin salivary supernatant showed a reduction of IKKß kinase activity. Significant reduction of IL-8 levels (P < 0.05) was seen in post-curcumin samples from patients with dental caries. Although there was reduced IL-8 expression in 8 of 21 post-curcumin samples of HNSCC patients, the data did not reach statistical significance. Saliva samples from HNSCC patients were also analyzed in a blinded fashion for expression of cytokines. IL-10, IFN-γ, IL-12p70, and IL-2 clustered together, and granulocyte macrophage colony stimulating factor and TNF-α clustered together. Log10 ratio analysis showed decrease in expression of all nine cytokines in both the salivary supernatant and salivary cells of curcumin-treated samples. CONCLUSIONS: Curcumin inhibited IKKß kinase activity in the saliva of HNSCC patients, and this inhibition correlated with reduced expression of a number of cytokines. IKKß kinase could be a useful biomarker for detecting the effect of curcumin in head and neck cancer.

Chemopreventive potential of 18beta-glycyrrhetinic acid: an active constituent of liquorice, in 7,12-dimethylbenz(a)anthracene induced hamster buccal pouch carcinogenesis.

Chemoprevention, a useful and attractive approach in experimental oncology, helps to investigate the cancer preventive potential of natural products and synthetic entities. Present study evaluated the chemopreventive potential of glycyrrhetinic acid in 7,12-dimethylbenz(a)anthracene (DMBA) induced hamster buccal pouch carcinogenesis. Oral tumor was developed in the buccal pouch of golden Syrian hamsters by painting with DMBA three times a week for 14 weeks. The tumor incidence and the status of phase I and phase II detoxification enzymes were assessed in hamsters treated with DMBA alone and DMBA+glycyrrhetinic acid treated hamsters. One hundred percent tumor formations, which were histopathologically confirmed as well-differentiated squamous cell carcinoma, were observed in hamsters treated with DMBA alone. Also, the status of detoxification enzymes were markedly altered in the liver and buccal mucosa of hamsters treated with DMBA alone. Oral administration ofglycyrrhetinic acid at a dose of 45 mg kg(-1) body weight to hamsters treated with DMBA completely prevented the tumor formation as well as restored the status of detoxification enzymes. Present study thus demonstrated the chemopreventive potential of glycyrrhetinic acid in DMBA induced oral carcinogenesis.

Influence of an extremely low frequency magnetic field (ELF-EMF) on antioxidative vitamin E properties in AT478 murine squamous cell carcinoma culture in vitro.

This study examines the effects of vitamin E and an extremely low frequency electromagnetic field (ELF-EMF) and their combination in different time intervals of exposure of vitamin E (tocopherol) on the AT478 murine squamous cell carcinoma line. This study provides insight into the influence of correlations between ELF-EMF and vitamin E supplementation on antioxidant enzyme activity in malignant cells in vitro. Following vitamin E treatment, activity of the antioxidant enzymes is increased in an exposure-dependent manner compared with the untreated group. Application of ELF-EMF alone or with vitamin E increases both superoxide dismutase isoenzymes and glutathione peroxidase activities in comparison to the control group. The results suggest that ELF-EMF alters antioxidative activities of vitamin E in AT478 tumor cells. This study confirms the role of vitamin E in decreasing susceptibility to lipid peroxidation in AT478 tumor cells.