Pharyngeal Cancer Cells Research Articles

Significance of Interleukin-6 Signaling in the Resistance of Pharyngeal Cancer to Irradiation and the Epidermal Growth Factor Receptor Inhibitor

Tumor eradication by chemoradiotherapy for pharyngeal cancer has not been particularly successful. Targeting epithelial growth factor receptor (EGFR) could be a potential treatment strategy providing additional benefits, but only a subset of these tumors gives a clinically significant response to EGFR inhibitors. The aim has been to identify the role of interleukin-6 (IL-6) signaling and its predictive power in the treatment response of pharyngeal cancer. Human pharyngeal cancer cell lines, including the hypopharyngeal cancer cell line FaDu and its derived cell line FaDu-C225-R, were selected. Changes in tumor growth, response to treatment, and responsible signaling pathway were investigated in vitro. Furthermore, 95 pharyngeal cancer tissue specimens were analyzed by immunohistochemical staining, and correlations were made between levels of IL-6, IL-6 receptor (IL-6R), p-AKT, and p-STAT3 expression and the clinical outcome of patients. In vitro, either extrinsic IL-6 stimulation of cancer cells or intrinsically activated IL-6 signaling detected in FADu-C225-R cells results in resistance to irradiation and EGFR inhibitor. Blocking IL-6 signaling attenuated aggressive tumor behavior and sensitized the cells to treatments. The responsible mechanisms included decreased p-STAT3, less nuclear translocation of EGFR, and subsequently attenuated epithelial-mesenchymal transition. Regarding clinical data, staining of p-STAT3 and IL-6 was significantly linked with lower response rates to treatments and shorter survival in pharyngeal cancer patients. IL-6 and p-STAT3 may be significant predictors of pharyngeal carcinoma, and regulating IL-6 signaling can be considered a promising therapeutic approach.

Cellular Recognition of Functionalized with Folic acid Nanoparticles

We have prepared extremely small functionalized nanoparticles (NPs) and showed that they could be introduced into living cells without modification (e.g. cationic coating) to enhance endocytic internalization. However, the internalization depended on physical adsorption of the particles on the cell surfaces, and therefore the internalization process was nonselective. Here, we prepared NPs conjugated with folic acid and a coumarin fluorophore so that the NPs (d = 2.6 nm) would be recognized by folate receptors on the cell surface. The presence of the folic acid and coumarin on the surface of the NPs was confirmed by Fourier transform infrared spectroscopy. The modified NPs were internalized by human pharyngeal cancer cells (KB cells) after an incubation time that was short compared with the time required for internalization of NPs without folic acid. This result indicates that the folic acid receptor on the KB cell membrane recognized the folic acid-conjugated NPs. Cellular recognition of NPs may lead to the development of cell-specific delivery systems. [DOI: 10.1380/ejssnt.2007.23]

Multifunctional polymeric micelles with folate-mediated cancer cell targeting and pH-triggered drug releasing properties for active intracellular drug delivery

A new type of multifunctional polymeric micelle drug carrier for active intracellular drug delivery was prepared and characterized in this study. The micelle is a nano-supramolecular assembly with a spherical core-shell structure, and its surface and core were modified with piloting molecules for cancer cells and pH-sensitive drug binding linkers for controlled drug release, respectively. In order to prepare such micelles, self-assembling amphiphilic block copolymers, folate-poly(ethylene glycol)-poly(aspartate hydrazone adriamycin) [Fol-PEG-P(Asp-Hyd-ADR)], were specially designed and synthesized by installing a molecular promoter to enhance intracellular transport, folate (Fol), at the end of the shell-forming PEG chain and conjugating the anticancer drug, adriamycin (ADR), to the side chain of the core-forming PAsp segment through an acid-sensitive hydrazone bond. Because folate-binding proteins (FBP) are selectively overexpressed on the cancer cell membranes, the folate-bound micelles (FMA) can be guided to the cancer cells in the body, and after the micelles enter the cells, hydrazone bonds are cleaved by the intracellular acidic environment (pH 5-6) so that the drug release profile of the micelles is controlled pH-dependently. In this regard, FBP-binding selectivity of the prepared FMA was evaluated by surface plasmon resonance (SPR) measurements. The tetrazolium dye method (MTT assay) using human pharyngeal cancer cells (KB cell) revealed that FMA significantly improved cell growth inhibitory activity in spite of a short exposure time due to the selective and strong interaction between folate molecules and their receptors. Subsequent flow cytometric analysis showed that cellular uptake of FMA significantly increased. Consequently, these findings would provide one of the most effective approaches for cancer treatment using intracellular environment-targeting supramolecular drug carriers.

Immunohistochemical localization of interleukin-10 in human oral and pharyngeal carcinomas.

Interleukin-10 (IL-10) is an immunosuppressive cytokine with numerous, well-described effects on the human cellular and humoral immune response. The oncogenic potential of IL-10 has been previously investigated in bronchogenic carcinoma, nasopharyngeal carcinoma, Waldeyer's ring carcinoma, and serum supernatants of patients with squamous cell carcinoma of the head and neck (SCCHN). The purpose of the study was to determine the prevalence and cellular localization of IL-10 in human SC-CHN. Immunohistochemistry of archival tissues. Paraffin-embedded archival tissues were retrospectively obtained from 98 patients with oral and pharyngeal squamous cell carcinoma. Using a standard immunohistochemical technique, these specimens were stained with a polyclonal antibody to IL-10. Using these methods, we found specific localization of antigenic IL-10 to individual tumor cells in 65% of tumors studied. Intensity of staining was significantly, but inversely, related to tumor grade and N stage; there also existed a significant staining predisposition for oral cavity lesions when samples from this site were compared with tissues derived from elsewhere in the pharynx. Furthermore, IL-10 was not localized to normal epithelial keratinocytes or inflammatory cells at the level of sensitivity achieved by the immunohistochemical methods used in the study. The findings demonstrate that IL-10 can be specifically localized to human oral and pharyngeal cancer cells. These data also suggest an inverse association for both tumor grade and N stage with specific tumor marker staining. Future studies should investigate the role of this cytokine in the pathogenesis of human SCCHN.

Analysis of heat-shock related gene expression in head-and-neck cancer using cDNA arrays

Purpose : The aim of the present study was to identify genes regulated in the early response to heat-shock in human head-and-neck cancer cells using a cDNA array. Methods and Materials : IMC-3 cells were heat-shocked at 44°C for 30 min, then incubated for 6 h. After 6 h incubation, mRNAs were extracted. Early gene expressions in IMC-3 cells were analyzed using a cDNA array after heat-shock. In addition, reverse transcription-polymerase chain reaction (RT-PCR) was performed to identify the expressions of mRNA for confirming features by cDNA array analysis in several other cell lines (KB, T3M-1, SCC-TF) as well as in IMC-3 cells. Results : Twenty-eight genes were found to be induced or upregulated by heat-shock in IMC-3 cells. These included genes involved in the apoptosis (e.g., CC3, caspase10), tumor invasion (e.g., CC3, TIMP-3), cell cycle checkpoint control (e.g., DP-1, CDC25A), signal transduction (e.g., MEK1) as well as genes associated with heat stress (e.g., Hsp70B′, Hsp40). Gene expressions of CC3 and MEK1 were recognized to be induced by heat-shock in pharyngeal cancer cells (KB, T3M-1) and lingual cancer cells (SCC-TF). Conclusion : The observed alteration in gene expression may play a role in various biochemical pathways of cancer cells exposed to heat-shock.