Human Epidermoid Carcinoma KB Cells Research Articles

Negative regulation of thyroid adenoma-associated protein (THADA) in the cardiac glycoside-induced anti-cancer effect

Cardiac glycosides, known as inhibitors of Na+,K+-ATPase, have anti-cancer effects such as suppression of cancer cell proliferation and induction of cancer cell death. Here, we examined the signaling pathway elicited by cardiac glycosides in the human hepatocellular carcinoma HepG2 cells and human epidermoid carcinoma KB cells. Three kinds of cardiac glycosides (ouabain, oleandrin, and digoxin) inhibited the cancer cell proliferation and decreased the expression level of thyroid adenoma-associated protein (THADA). Interestingly, the knockdown of THADA inhibited cancer cell proliferation, and the proliferation was significantly rescued by re-expression of THADA in the THADA-knockdown cells. In addition, the THADA-knockdown markedly decreased the expression level of L-type amino acid transporter LAT1. Cardiac glycosides also reduced the LAT1 expression. The LAT1 inhibitor, JPH203, significantly weakened the cancer cell proliferation. These results suggest that the binding of cardiac glycosides to Na+,K+-ATPase negatively regulates the THADA-LAT1 pathway, exerting the anti-proliferative effect in cancer cells.

Impaired actin filaments decrease cisplatin sensitivity via dysfunction of volume-sensitive Cl- channels in human epidermoid carcinoma cells.

Cisplatin is a widely used platinum-based anticancer drug in the chemotherapy of numerous human cancers. However, cancer cells acquire resistance to cisplatin. So far, functional loss of volume-sensitive outwardly rectifying (VSOR) Cl- channels has been reported to contribute to cisplatin resistance of cancer cells. Here, we analyzed protein expression patterns of human epidermoid carcinoma KB cells and its cisplatin-resistant KCP-4 cells. Intriguingly, KB cells exhibited higher β-actin expression and clearer actin filaments than KCP-4 cells. The β-actin knockdown in KB cells decreased VSOR Cl- currents and inhibited the regulatory volume decrease (RVD) process after cell swelling. Consistently, KB cells treated with cytochalasin D, which depolymerizes actin filaments, showed smaller VSOR Cl- currents and slower RVD. Cytochalasin D also inhibited cisplatin-triggered apoptosis in KB cells. These results suggest that the disruption of actin filaments cause the dysfunction of VSOR Cl- channels, which elicits resistance to cisplatin in human epidermoid carcinoma cells.

Cisplatin-loaded hollow gold nanoparticles for laser-triggered release

BackgroundHollow gold nanoparticles (HGNPs) exposed to near-infrared (NIR) light yield photothermal effects that can trigger a variety of biological effects for potential biomedical applications. However, the mechanism of laser-triggered drug release has not been studied before.MethodsA tripeptide Ac-Glu-Glu-Cys-NH2 (Ac-EEC) was directly linked to the surface of HGNPs. The EEC-HGNPs conjugate was then complexed with cisplatin Pt(II) to give Ac-EEC(Pt)-HGNPs. Folic acid was introduced to the gold surface of Ac-EEC-HGNPs through a thioctic acid-terminated polyethylene glycol linker (F-PEG-TA) followed by complexation with Pt(II) to give F-Ac-EEC(Pt)-HGNPs. Laser treatment was instituted with a 15-ns pulsed laser at a repetition rate of 10 Hz. The released Pt(II) was quantified by inductively coupled plasma mass spectroscopy, and the nature of the released Pt-containing species was characterized by liquid chromatography–mass spectroscopy. The cytotoxicity was studied using the MTT assay.ResultsPt(II) was released from Ac-EEC(Pt)-HGNPs via two modes: (1) sustained release through an inverse ligand exchange reaction with chloride ions and (2) rapid release through cleavage of the Au–S bond between the tripeptide linker and Au surface upon NIR laser irradiation. The folate (F) conjugate of the nanoconstruct, F-Ac-EEC(Pt)-HGNPs, in combination with laser treatment showed a significantly greater effect on cell mortality against folate-overexpressing human epidermoid carcinoma KB cells than F-Ac-ECC(Pt)-HGNPs alone after 24 h of incubation.ConclusionsThese results demonstrate that the photothermal property of HGNPs can be used for dual-modality photothermal therapy and NIR laser-triggered platinum-based chemotherapy.

Cytotoxic Effect of Thymus caramanicus Jalas on Human Oral Epidermoid Carcinoma KB Cells.

Identifying new chemotherapeutic agents with fewer side effects is a major concern for scientists today. Thymus caramanicus Jalas (Lamiaceae family) is one of the species of Thymus that grows wild in different regions of Iran. Traditionally, leaves of this plant are used in the treatment of diabetes, arthritis and cancer. Here was investigated the cytotoxic property of Thymus caramanicus essential oil and extract in human oral epidermoid carcinoma KB cells. Cell viability was measured by MTT and neutral red assays. The cells were exposed to different concentrations of essential oil (0.05-1 µL/mL) and extract (25-150 µg/mL) for 24 h. Doxorubicin was used as anticancer control drug. The data showed that the essential oil (IC50=0.44 µL/mL) and extract (IC50=105 µg/mL) induce potent cytotoxic property. Surprisingly, cytotoxic effects of essential oil and extract of this plant on KB cancer cells were greater than those on normal gingival HGF1-PI1 cell line. In addition, Thymus caramanicus could potentiate the effect of doxorubicin in sub-effective concentrations. The results of the present study indicate that essential oils and extracts of Thymus caramanicus have potential anti-proliferative property on KB cells and can be used as pharmaceutical case study for oral cancer treatments.

Penifupyrone, a new cytotoxic funicone derivative from the endophytic fungus Penicillium sp. HSZ-43

Penifupyrone (1), a new funicone derivative, has been isolated from the endophytic fungus Penicillium sp. HSZ-43, along with three known analogues, funicone (2), deoxyfunicone (3) and 3-O-methylfunicone (4). These structures were identified by using spectroscopic methods, including UV, MS, 1D and 2D NMR experiments. The structure of 1 was confirmed by single-crystal X-ray diffraction analysis. All the isolated compounds were evaluated for cytotoxicity against human oral epidermoid carcinoma KB cells, and compound 1 exhibited moderate cytotoxic activity with IC50 value of 4.7 μM.

JNK signaling maintains the mesenchymal properties of multi-drug resistant human epidermoid carcinoma KB cells through snail and twist1

Background and methodsIn addition to possess cross drug resistance characteristic, emerging evidences have shown that multiple-drug resistance (MDR) cancer cells exhibit aberrant metastatic capacity when compared to parental cells. In this study, we explored the contribution of c-Jun N-terminal kinases (JNK) signaling to the mesenchymal phenotypes and the aberrant motile capacity of MDR cells utilizing a well characterized MDR cell line KB/VCR, which is established from KB human epidermoid carcinoma cells by vincristine (VCR), and its parental cell line KB.ResultsTaking advantage of experimental strategies including pharmacological tool and gene knockdown, we showed here that interference with JNK signaling pathway by targeting JNK1/2 or c-Jun reversed the mesenchymal properties of KB/VCR cells to epithelial phenotypes and suppressed the motile capacity of KB/VCR cells, such as migration and invasion. These observations support a critical role of JNK signaling in maintaining the mesenchymal properties of KB/VCR cells. Furthermore, we observed that JNK signaling may control the expression of both snail and twist1 in KB/VCR cells, indicating that both snail and twist1 are involved in controlling the mesenchymal characteristics of KB/VCR cells by JNK signaling.ConclusionJNK signaling is required for maintaining the mesenchymal phenotype of KB/VCR cells; and JNK signaling may maintain the mesenchymal characteristics of KB/VCR cells potentially through snail and twist1.

Quercetin Induces Apoptosis via the Mitochondrial Pathway in KB and KBv200 Cells

In this study, anticancer activities of six compounds of flavonoids were investigated in human epidermoid carcinoma KB and KBv200 cells. Among these compounds, quercetin and acacetin showed strong inhibition of cell growth in KB and KBv200 cells. IC50 values of quercetin against KB and KBv200 cells were 17.84 ± 4.14 and 18.94 ± 4.75 μM, respectively. The IC50 values of acacetin against KB and KBv200 cells were 41.33 ± 6.05 and 49.04 ± 3.64 μM. The IC50 values of apigenin, kaempferol, kaempferol 3-O-rhamnoside, and quercetin 3-O-rhamnoside were more than 100 μM. Furthermore, quercetin was found to induce apoptosis in KB and KBv200 cells via the mitochondrial pathway, including a decrease of the reactive oxygen species level, loss of mitochondrial membrane potential, release of cytochrome c, activation of caspase-9 and caspase-3, and cleavage of poly (ADP-ribose) polymerase. The apoptosis induced by quercetin was not related to the regulation of Bcl-2 or Bax in KB and KBv200 cells.

Thymidine phosphorylase enhances reactive oxygen species generation and interleukin-8 expression in human cancer cells

Thymidine phosphorylase (TP) is an angiogenic factor that plays a pivotal role in tumor angiogenesis. Various kinds of solid tumors express TP and high TP activity is correlated with microvessel density. We have previously reported that TP enhances interleukin-8 (IL-8) expression in KB human epidermoid carcinoma cells. In this study, TP was shown to be involved in enhanced expression of IL-8 in EJ human bladder cancer cells and Yumoto human cervical cancer cells as well as KB human epidermoid carcinoma cells. The enzymatic activity of TP was required for the enhanced expression of IL-8. A degradation product of thymidine was implicated in the enhanced expression of IL-8. TP augmented reactive oxygen species (ROS) generation in KB and Yumoto cells, and the enzymatic activity of TP was again required for the generation of ROS. An antioxidant, N-acetylcysteine (NAC), attenuated the generation of ROS and IL-8mRNA expression in KB and Yumoto cells, and H2O2 increased IL-8mRNA expression in Yumoto cells, suggesting that ROS generated by TP caused the increased expression of IL-8mRNA. Since TP also reduced cellular glutathione levels and transcription of γ-GCS in KB cells, the TP-induced augmentation of ROS may be partially attributed to the decreased glutathione. Our findings suggest that thymidine-derived sugars enhanced ROS generation and consequently increased IL-8 expression.

Novel Terpenoids from Calocedrus macrolepis var. formosana

Calocetriol (1), diacetylcalocediol (2), and ferrugimenthenol (3) were isolated from the bark of Calocedrus macrolepis var. formosana. Among them, 1 and 2 are secoabietane-type diterpenoids, and 3, with a novel C(20)-C(10) skeleton, is classified as a meroterpenoid. The structures of 1-3 were elucidated by spectroscopic analyses, and their biological activities were also evaluated. Compound 3 exhibited significant cytotoxic activity against human oral epidermoid carcinoma KB cells with an IC(50) value of 9.0±0.1 μM.

Cleistanone: A Triterpenoid from Cleistanthus indochinensis with a New Carbon Skeleton

AbstractCleistanone (1) was isolated from the leaves of Cleistanthus indochinensis and features a new type of triterpenoid carbon skeleton. Its structure was confirmed by X‐ray diffraction analysis. A plausible biosynthetic pathway was proposed for 1 and is thought to proceed through a Wagner–Meerwein rearrangement. Cleistanone (1) was found to show cytotoxic activity against human oral epidermoid carcinoma KB cells.

Abstract 1528: Activation of NRF2/ABCC1 axis confers resistance to topoisomerase II poisons in human oral malignancies

Abstract Etoposide (VP-16), a DNA topoisomerase II poison, is an important clinical used chemotherapeutic agent for human oral malignancies. An etoposide-resistant cell line, KB-7D, has been generated from human oral epidermoid carcinoma KB cells to investigate the mechanism of action of drug resistance in oral malignancies. Previous studies revealed that KB-7D cells were approximately 50-fold more resistant to etoposide as compared to parental KB cells. It also exhibited cross-resistant to chemotherapeutic agents such as doxorubicin. This multi-drug resistance may be caused by the over-expression of ABCC1, leading to the decrease in drug accumulation in KB-7D cells. Our current work continues the effort to investigate the mechanism of regulation of ABCC1 expression in the etoposide-derived drug resistant cells and subsequently find the molecular target that can be used to restore therapeutic efficacy in chemo-refratory cancers. Down-regulation of ABCC1 by RNA interference and a selective inhibitor, MK-571, significantly enhanced the chemosensitivity to etoposide and doxorubicin in KB and KB-7D cells. To further determine the possible transcriptional factors that regulate the ABCC1 transactivation, the promoter region of ABCC1 was examined. A NRF2 binding sequence, antioxidant responsive element (ARE), has been found locate in the ABCC1 promoter at -470 to -458 upstream from the transcription start site. Real-time RT-PCR and Western blot analyses showed that expression of NRF2 mRNA and protein in KB-7D cells was 1.4 to 1.8 folds higher than those expressed in the parental cells. In addition, Chromatin Immunoprecipitation (ChIP) analysis revealed that NRF2 directly targeted to the ARE sequence in the ABCC1 promoter region. Interestingly, down-regulation of NRF2 decreased the expression of ABCC1 and also increased the chemosensitivity of KB-7D cells against selected anti-cancer drugs. In addition, cells incubated with an NRF2 activator, tBHQ, induced nucleus accumulation of NRF2 and over-expression of ABCC1, resulting in the enhancement of drug-resistance against etoposide or doxorubcin in KB and KB-7D cells. In summary, constitutive activation of NRF2-dependent ABCC1 contributed to the causation of chemoresistance in etoposide-derived drug resistant cells. Blockage of ABCC1 expression by manipulation of the NRF2 signaling pathway enhanced the chemotherapeutic efficacy in cells. Therefore, targeting NRF2 may be able to reverse chemoresistance in chemo-refractory oral malignancies. In addition, development of NRF2 inhibitors may be a new strategy to overcome chemoresistance in human cancers. (The study was supported by grants of Department of Health DOH99-TD-C-111-004, Taiwan.) Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 1528. doi:10.1158/1538-7445.AM2011-1528

Effect of PG0839 gene of Porphyromonas gingivalis on inflammatory cytokine in human oral epidermoid carcinoma KB cell

To investigate the effect of PG0839 gene form Porphyromonas gingivalis (Pg) on inflammatory cytokine expression in human oral epidermoid carcinoma KB cell. A mutant in the PG0839 gene of Pg was created by insertional inactivation. Group 1 was chanllenged with PgW83 strain, group 2 with PG0839-defective mutant, and the control group with Dulbecco's modified Eagle's medium only. KB cells were co-cultured with presence of bacteria for 24 h. At the time point of 0.5, 2, 6, 12 and 24 h, cells were stored in Trizol. The mRNA expression of interleukin-1β (IL-1β) and Toll like recepector-4 (TLR-4) was examined by reverse transcription polymerase chain reaction. At 2 h and 6 h, IL-1β mRNA expression was lower in group 2 than in group 1 (2 h: 0.31 ± 0.11 versus 0.95 ± 0.48, P < 0.05; 6 h: 0.57 ± 0.20 versus 1.29 ± 0.55, P < 0.05). At 0.5 h and 6 h, TLR-4 mRNA expression was lower in group 2 than in group 1 (0.5 h: 0.20 ± 0.09 versus 0.58 ± 0.09, P < 0.05; 6 h: 0.34 ± 0.04 versus 0.71 ± 0.18, P < 0.05). PG0839 gene may play an important role in Pg-induced inflammatory effects of KB cell.

ChemInform Abstract: Labdanecaryophyllic Acid, a Novel Cytotoxic C35 Terpenoid from Calocedrus macrolepis var. formosana.

Abstract Chemical investigation of the bark of Calocedrus macrolepis var. formosana, an endemic tree in Taiwan, has led to the isolation of a novel terpenoid 1. Compound 1 with a rare C35 skeleton constructed by a diterpene and a sesquiterpene moieties. Its structure was elucidated by spectroscopic interpretations. The anti-proliferation activity of 1 against human oral epidermoid carcinoma KB cells was evaluated, and the IC50 value was determined to be 9.2 ± 0.4 μM.

Labdanecaryophyllic acid, a novel cytotoxic C 35 terpenoid from Calocedrus macrolepis var. formosana

Chemical investigation of the bark of Calocedrus macrolepis var. formosana, an endemic tree in Taiwan, has led to the isolation of a novel terpenoid 1. Compound 1 with a rare C 35 skeleton constructed by a diterpene and a sesquiterpene moieties. Its structure was elucidated by spectroscopic interpretations. The anti-proliferation activity of 1 against human oral epidermoid carcinoma KB cells was evaluated, and the IC 50 value was determined to be 9.2 ± 0.4 μM.

Cytotoxic terpenoids from Calocedrus macrolepis var. formosana

Calocetriol (1), diacetylcalocediol (2), abeoabietalignol (3), labdanecaryophyllic acid (4), and ferrugimenthenol (5) were isolated from the bark of Calocedrus macrolepis var. formosana. Compounds 1 and 2 are secoabietane-type diterpenoids, and 3-5 with respective C30, C35, and C30 skeletons are novel meroterpenoids. Their structures were characterized by spectroscopic analysis. Of these compounds identified, 3-5 exhibited significant cytotoxic activities against human oral epidermoid carcinoma KB cells with IC50 values of 8.9±0.1, 9.2±0.4, and 9.0±0.1µM, respectively.

ChemInform Abstract: Novel Pyrrolo(2,3-d)pyrimidine Antifolates: Synthesis and Antitumor Activities.

New antifolates, characterized by a 6-5 fused ring system, a pyrrolo[2,3-d]pyrimidine ring, and a trimethylene bridge at position 5 (12a,b and 13a,b) were designed and efficiently synthesized. The synthetic method included (1) construction of the key intermediary acyclic skeleton, 5-[4-(tert-butoxycarbonyl)phenyl]- 2-(dicyanomethyl)pentanoates (6a,b), (2) cyclization with guanidine, followed by reduction to the pyrrolo[2,3-d]pyrimidine derivatives (8a,b and 9a,b), and (3) subsequent glutamate coupling and saponification. These antifolates were more growth-inhibitory by about 1 order of magnitude than methotrexate (MTX) against KB human epidermoid carcinoma cells and A549 human nonsmall cell lung carcinoma cells in in vitro culture. Growth inhibitory IC50 values for N-[4-[3-(2,4-diamino-7H-pyrrolo[2,3-d]pyrimidin-5- yl)propyl]benzoyl]-L-glutamic acid (12a) against KB and A549 were 0.27 and 4.5 ng/mL, while those for MTX were 5.0 and 35 ng/mL, respectively. Other members of this class of antifolates, 12b and 13a,b, showed good activities nearly equal to that of 12a.

The role of thymidine phosphorylase in the induction of early growth response protein-1 and thrombospondin-1 by 5-fluorouracil in human cancer carcinoma cells

Thymidine phosphorylase (TP) is an enzyme involved in reversible conversion of thymidine to thymine. TP is identical to an angiogenic factor, pletelet-derived endothelial cell growth factor (PD-ECGF) and the expression levels of TP in a variety of malignant tumors were higher than the adjacent non-neoplastic tissues. To investigate the molecular basis for the effect of TP on the metabolic process and the anticancer effect of 5-fluorouracil (5-FU), human gastric carcinoma AZ521 cells and epidermoid carcinoma KB cells were transfected with TP cDNA, and AZ521/TP and KB/TP were cloned. AZ521/TP and KB/TP cells overexpressed TP and were more sensitive to 5-FU than the counterpart parental cells. TPI, a newly synthesized inhibitor for TP (Ki=2.36 x 10(-9) M), decreased the sensitivity to 5-FU of the TP expressing cells but not of the parental cells. 5-Formyl-tetrahydrofolate (leucovorin; LV) stabilized the complex of thymidylate synthase (TS) and 5-fluoro-deoxyuridine-monophosphate (FdUMP), increased the sensitivity to 5-FU of TP expressing AZ521 cells, but not of the parental cells. The levels of FdUMP in TP expressing cells were significantly higher than in parental cells and TPI considerably decreased FdUMP to the level comparable to that in the parental cells. 5-FU increased the expression of early growth response protein-1 (Egr-1) and an angiogenesis inhibitor, thrombospondin-1 (TSP-1), in KB/TP cells but only slightly in KB/CV cells, if any. TPI attenuated the induction of Egr-1 and TSP-1 mRNA by 5-FU, while LV increased the expression of Egr-1 and TSP-1 mRNA in KB/TP cells. These findings demonstrate that the TP has a principal role in the production of FdUMP and the enhanced responses to 5-FU by leucovorin in TP-overexpressing KB and AZ521 cells, and FdUMP but not FUTP is implicated in the induction of Egr-1 and TSP-1 in KB cells.

Hydrogenative desulphurization of thienopyrrolizinones: An easy and selective access to ( Z)-phenethylidenepyrrolizinones with in vitro cytotoxic activity

Attempts in view to dearomatize some previously reported tripentones with potent antineoplastic activities led in thiophene series to an unexpected hydrogenative desulphurization reaction. The resulting ( Z)-phenethylidenepyrrolizinones were tested in vitro over human epidermoid carcinoma KB cell line. The results of this biological evaluation indicated that the tricyclic core of our model can be cleaved with a partial respect of the activity.

Effects of Panduratin A Isolated from Kaempferia pandurata ROXB. on the Expression of Matrix Metalloproteinase-9 by Porphyromonas gingivalis Supernatant-Induced KB Cells

Periodontitis is initiated by accumulation of microbial plaque and activation of gingival inflammation through overexpression of matrix metalloproteinases (MMPs), leading to tissue destruction. Natural MMP inhibitors may be developed as therapeutic agents against periodontitis. In this study, panduratin A, a natural bioactive compound isolated from Kaempferia pandurata ROXB., was used to test its in vitro inhibitory activity against MMP-9 secretion from Porphyromonas gingivalis supernatant-induced human oral epidermoid carcinoma KB cells. Gelatin zymography, Western blot and RT-PCR analyses were performed to evaluate MMP-9 expression. The gelatin zymograms revealed that the main gelatinase secreted by P. gingivalis supernatant-induced KB cells migrated at 92 kDa, representing MMP-9. MMP-9 protein and mRNA levels were significantly decreased after panduratin A treatment (p<0.05). In contrast, panduratin A had no effect on tissue inhibitor of metalloproteinases (TIMP)-1 and TIMP-2 mRNA. Panduratin A also suppressed urokinase type plasminogen activator (uPA) mRNA expression. These results suggest that panduratin A could potentially prevent periodontal inflammation by decreasing the levels of MMP-9 protein and mRNA.

Reversal effect of resveratrol on multidrug resistance in KBv200 cell line

A multidrug-resistant clone of human oral epidermoid carcinoma KB cells was isolated by stepwise selection on exposure to increasing doses of vincristine. The final clone, KBv200, obtained after ethylmethane sulfonate mutagenesis showed 156-fold higher resistance to vincristine than KB cells. The cells were also cross-resistant to paclitaxel and adriamycin. The aim of this study was to explore the reversal effect and potential mechanism of resveratrol on KBv200 cells. MTT assay was used to investigate the reversal index of resveratrol to vincristine, adriamycin and paclitaxel. Cell apoptosis was measured by flow cytometry. RT-PCR and western blot were used to detect mRNA and protein expression of multidrug-resistant gene MDR1 and apoptosis-suppressing gene Bcl-2. Resveratrol produced a synergistic effect combined with the chemotherapeutic agents and reversed the multidrug-resistant phenotype of KBv200 cells. Flow cytometry confirmed that the percentage of apoptotic cell increased when KBv200 cells were exposed to resveratrol. The results of gene detection showed that the expression levels of MDR1 and Bcl-2 were decreased upon resveratrol treatment. Resveratrol can efficiently reverse multidrug resistance in KBv200 cells. The potential mechanism may be via inhibiting the multidrug-resistant gene expressions and/or promoting cell apoptosis.