Cytokeratin expression in initial oral mucositis of head and neck irradiated patients

A Tissue Engineered 3D Model of Cancer Cell Invasion for Human Head and Neck Squamous-Cell Carcinoma

Head and neck squamous-cell carcinoma (HNSCC) is associated with aggressive local invasiveness, being a main reason for its poor prognosis. The exact mechanisms underlying the strong invasive abilities of HNSCC remain to be elucidated. Therefore, there is a need for in vitro models to study the interplay between cancer cells and normal adjacent tissue at the invasive tumor front. To generate oral mucosa tissue models (OMM), primary keratinocytes and fibroblasts from human oral mucosa were isolated and seeded onto a biological scaffold derived from porcine small intestinal submucosa with preserved mucosa. Thereafter, we tested different methods (single tumor cells, tumor cell spots, spheroids) to integrate the human cancer cell line FaDu to generate an invasive three-dimensional model of HNSCC. All models were subjected to morphological analysis by histology and immunohistochemistry. We successfully built OMM tissue models with high in vivo-in vitro correlation. The integration of FaDu cell spots and spheroids into the OMM failed. However, with the integration of single FaDu cells into the OMM, invasive tumor cell clusters developed. Between segments of regular epithelial differentiation of the OMM, these clusters showed a basal membrane penetration and lamina propria infiltration. Primary human fibroblasts and keratinocytes seeded onto a porcine carrier structure are suitable to build an OMM. The HNSCC model with integrated FaDu cells could enable subsequent investigations into cancer cell invasiveness.

Does Photobiomodulation Affects CK10 and CK14 in Oral Mucositis Radioinduced Repair?

The mechanisms of action of photobiomodulation (PBM) in oral mucositis (OM) are not completely elucidated. To enlighten the role of PBM in the evolution of epithelial maturity in OM ulcers, the present study evaluated the effect of PBM with red (λ) wavelength of 660 nanometers (nm) and infrared of 780 nm in radio-induced OM wounds on the tongue of rats, eight and twenty days after irradiation with single dose of 20 Gy. The percentage area corresponding to positive staining for cytokeratin 10 (CK10) and 14 (CK14) proteins was evaluated in the epithelial area of the lesions, using an immunohistochemical technique (IHC), 8 and 20 days after the induction of lesions, and compared with an untreated control group. CK10 was significantly more expressed in the group treated with 660 nm PBM. CK14 did not show quantitative differences between the groups evaluated. However, whereas in the groups treated with PBM, CK14 was already restricted to the basal layer of the epithelium, as expected in healthy epithelia, in control group it was also expressed in upper layers of the epithelium. In this work, PBM was able to improve epithelial maturity of the repaired OM wound, especially in the 660 nm group.

Distribution of Cytokeratin 17 in the Parenchymal Elements of Rat's Submandibular Glands Subjected to Fractionated Radiotherapy

Objectives  The aim of this research was to study the intensity of cytokeratin 17 (CK17) in the parenchymal elements of rat’s submandibular salivary glands subjected to fractionated radiotherapy regimen that used for treatment of head and neck malignancy.

Materials and Methods  Twenty male albino rats were divided into two equal groups (normal and irradiated). The irradiated group received a radiation dose of 5 Grays daily for 5 days using therapeutic X-ray beam. Six months later, submandibular gland was dissected out and prepared for both histological and immunohistochemical studies.

Results  Submandibular gland of irradiated group showed two different types of histological alterations. The first alteration showed severe gland atrophy replaced by either fibrous or fatty tissues. In some sections, the gland exhibited proliferating activity in the form of profuse amounts of mitotic figures. Immunohistochemical examination of control glands displayed a mild cytoplasmic expression of CK17 of duct cells as well as serous acini. The staining pattern was either diffused or concentrated at the basal part of the cell with negative expression at its apical part.

Statistical Analysis  Expression of CK17 in submandibular gland of irradiated group displayed a highly significant differences (P < 0.001) in both intercalated and striated ducts. Many serous acini displayed a highly significant differences (P < 0.001) whereas, mucous acini were negatively stained.

Conclusions  The intensity and diffusion of CK17 expression in our results foretell the pathological effect of radiotherapy on the intermediate filaments of salivary gland parenchyma that interfered with production and/or secretion of saliva leading to xerostomia.

Modulation of radiation-induced oral mucositis (mouse) by dermatan sulfate: effects on differentiation processes

PURPOSE

During head and neck cancer radiotherapy, oral mucositis is the most frequent early side effect. Systemic dermatan sulfate (DS) administration has been shown to significantly decrease oral mucosal radiation reactions during daily fractionated irradiation (IR) in an established mouse model. The aim of this study was to investigate the mechanism of the oral epithelial differentiation process, during IR alone and in combination with DS treatment in the same mouse model.

METHODS

Fractionated IR 5 × 3 Gy/week was given to the snouts of mice over two weeks, either alone (IR) or in combination with daily DS treatment of 4 mg/kg (IR + DS). Groups of mice (n = 3) were sacrificed every second day over the course of 14 days in both experimental arms. Their tongue was excised and subjected to immunohistochemical processing.

RESULTS

In the p16 analysis as a proliferation marker, the difference between IR alone and IR + DS in the germinal (proliferation) layer was not significant, not stimulating the proliferation process. For the p21 analysis as a differentiation marker on the functional (differentiation) layer, the difference between IR alone and IR + DS arms was significant, indicating that DS inhibited the differentiation process. In the cytokeratin (CK) analysis as the indicator of cellular skeletal integrity, the percentage of antibody-positive cells was above the normal level in both experimental arms and significantly superior in the IR + DS arm.

CONCLUSION

The mucosal protective activity of DS, instead of stimulating proliferation, is based on prevention of cell loss by a combination of effects leading to the inhibition of cellular differentiation and an increase in the expression of epithelial mechanical strength between intercellular mechanical junctions.

Oral mucosa tissue gene expression profiling before, during, and after radiation therapy for tonsil squamous cell carcinoma

Background

Radiation-therapy (RT) induces mucositis, a clinically challenging condition with limited prophylactic interventions and no predictive tests. In this pilot study, we applied global gene-expression analysis on serial human oral mucosa tissue and blood cells from patients with tonsil squamous cell cancer (TSCC) to identify genes involved in mucositis pathogenesis.

Methods and findings

Eight patients with TSCC each provided consecutive buccal biopsies and blood cells before, after 7 days of RT treatment, and 20 days following RT. We monitored clinical mucositis and performed gene-expression analysis on tissue samples. We obtained control tissue from nine healthy individuals. After RT, expression was upregulated in apoptosis inducer and inhibitor genes, EDA2R and MDM2, and in POLH, a DNA-repair polymerase. Expression was downregulated in six members of the histone cluster family, e.g., HIST1H3B. Gene expression related to proliferation and differentiation was altered, including MKI67 (downregulated), which encodes the Ki-67-proliferation marker, and KRT16 (upregulated), which encodes keratin16. These alterations were not associated with the clinical mucositis grade. However, the expression of LY6G6C, which encodes a surface immunoregulatory protein, was upregulated before treatment in three cases of clinical none/mild mucositis, but not in four cases of ulcerative mucositis.

Conclusion

RT caused molecular changes related to apoptosis, DNA-damage, DNA-repair, and proliferation without a correlation to the severity of clinical mucositis. LY6G6C may be a potential protective biomarker for ulcerative mucositis. Based on these results, our study model of consecutive human biopsies will be useful in designing a prospective clinical validation trial to characterize molecular mucositis and identify predictive biomarkers.

Rapid Decrease in KRT14 and TP53 mRNA Expression in the Buccal Mucosa of Patients Receiving Total-Body Irradiation for Allogeneic Stem Cell Transplantation

The only curative treatment option for relapsed patients with acute myeloid leukemia (AML) is allogeneic stem cell transplantation. Depletion of hematopoietic stem cells and leukemic blast cells is achieved through the systemic administration of DNA damaging agents, including total-body irradiation (TBI) prior to transplantation. Since other tissues are radiosensitive, the identification of biomarkers could facilitate the management of additional toxicities. Buccal keratinocytes are readily accessible and could provide a source of cells for RNA analysis. In this study, we obtained miRNAs and mRNAs from daily buccal swabs collected from patients undergoing allogeneic stem cell transplantation. Unexpectedly, there was no prominent p53-induced mRNA or miRNA response in these samples, despite the fact that the p53 pathway is a well-characterized radiation-inducible response. Instead, the expression of mRNAs encoding p53 and cytokeratin 14 (TP53 and KRT14, respectively) decreased precipitously within hours of the first radiation treatment. These patients went on to develop oral mucositis, however, it is unclear whether TP53 and/or KRT14 expression are predictive of this adverse event. Larger scale analysis of buccal epithelial samples from patients undergoing allogeneic stem cell transplantation appears to be warranted.

A systematic review of molecular responses to cancer therapy in normal human mucosa

OBJECTIVE

Cancer therapy-induced inflammation of oral and gastrointestinal mucosae affects patients nonuniformly. Preventive strategies are limited; no biomarker exists for pretreatment identification of patients likely to be severely affected. Animal models are preferred for studying molecular responses in mucosae during chemotherapy, but translation into clinical practice is difficult. We performed a systematic review to retrieve articles that described molecular changes in human mucosae during cancer therapy.

STUDY DESIGN

We searched MEDLINE and Ovid Embase searches for studies reported in the English language literature from January 1990 to November 2016 and studies referenced in selected articles, which analyzed mucosae from patients at risk of developing mucositis during cancer therapy. Two authors extracted data according to predefined data fields, including study quality indicators.

RESULTS

We identified 17 human studies on chemotherapy (n = 9) and radiotherapy (n = 8), but no studies on targeted therapy. Studies were heterogeneous with regard to patient cohorts, analysis methods, cancer treatments, biopsy timings, and correlations to clinical mucositis. Consequently, a meta-analysis was not feasible.

CONCLUSIONS

Few human studies described the molecular responses of the normal mucosa to cancer therapy. Studies were heterogeneous and had sparse correlations to clinical mucositis. We proposed a model for acquiring data on treatment- and disease-specific phenotypes and transcriptomes for predictive or preventive initiatives.

Carbon ions and X‑rays induce pro‑inflammatory effects in 3D oral mucosa models with and without PBMCs

Oral mucositis is a severe complication of radiotherapy. Hence, it may constitute a serious medical safety risk for astronauts during extended space flights, such as missions to Mars, during which they are exposed to heavy-ion irradiation. For risk assessment of developing radiation-induced mucositis, a three-dimensional (3D) organotypic oral mucosa model was irradiated with 12C heavy ions or X‑rays. The present study focused mainly on early radiation‑induced effects, such as the activation of nuclear factor κB (NFκB) and the expression or release of pro-inflammatory marker molecules. The 3D oral mucosa models with or without peripheral blood mononuclear cells (PBMCs) were irradiated with X‑rays or 12C heavy ions followed by snap freezing. Subsequently, cryosections were derived from the specimens, which were immunostained for analysis of compactness, DNA double strand breaks (DSB) and activation of NFκB. Radiation‑induced release of interleukin 6 (IL6) and interleukin 8 (IL8) was quantified by ELISA. Quantification of the DNA damage in irradiated mucosa models revealed distinctly more DSB after heavy-ion irradiation compared to X‑rays at definite time points, suggesting a higher gene toxicity of heavy ions. NFκB activation was observed after treatment with X‑rays or 12C particles. ELISA analyses showed significantly higher IL6 and IL8 levels after irradiation with X‑rays and 12C particles compared to non-irradiated controls, whereas co‑cultures including PBMCs released 2 to 3-fold higher interleukin concentrations compared to mucosa models without PBMCs. In this study, we demonstrated that several pro-inflammatory markers are induced by X‑rays and heavy-ion irradiation within an oral mucosa model. This suggests that oral mucositis indeed poses a risk for astronauts on extended space flights.

HIV nucleoside reverse transcriptase inhibitors efavirenz and tenofovir change the growth and differentiation of primary gingival epithelium

OBJECTIVES

An increasing number of HIV-infected patients are combating HIV infection through the use of antiretroviral drugs, including reverse transcriptase inhibitors. Oral complications associated with these drugs are becoming a mounting cause for concern. In our previous studies, both protease inhibitors and reverse transcriptase inhibitors have been shown to change the proliferation and differentiation state of oral tissues. This study examined the effect of a nonnucleoside and a nucleoside reverse transcriptase inhibitor on the growth and differentiation of gingival epithelium.

METHODS

Organotypic (raft) cultures of gingival keratinocytes were treated with a range of efavirenz and tenofovir concentrations. Raft cultures were immunohistochemically analysed to determine the effect of these drugs on the expression of key differentiation and proliferation markers, including cytokeratins and proliferating cell nuclear antigen (PCNA).

RESULTS

These drugs dramatically changed the proliferation and differentiation state of gingival tissues when they were present throughout the growth period of the raft tissue as well as when drugs were added to established tissue on day 8. Treatment with the drugs increased the expression of cytokeratin 10 and PCNA and, conversely, decreased expression of cytokeratin 5, involucrin and cytokeratin 6. Gingival tissue exhibited increased proliferation in the suprabasal layers, increased fragility, and an inability to heal itself.

CONCLUSIONS

Our results suggest that efavirenz and tenofovir treatments, even when applied in low concentrations for short periods of time, deregulated the cell cycle/proliferation and differentiation pathways, resulting in abnormal epithelial repair and proliferation. Our system could be developed as a potential model for studying the effects of HIV and highly active antiretroviral therapy (HAART) in vitro.

Effect of salivary stimulation therapies on salivary flow and chemotherapy-induced mucositis: a preliminary study

OBJECTIVE

The objective of this study was to evaluate the effect of salivary stimulation therapies on the salivary flow, oral mucositis, and salivary cytokine levels in patients receiving allogeneic hematopoietic stem cell transplantation.

STUDY DESIGN

Thirty-five eligible patients were randomized into 4 groups: control, mechanical sialogogue, transcutaneous electrical nerve stimulation (TENS) sialogogue, and combined mechanical/electrical sialogogue. Saliva was collected from patients before transplantation and at days 3, 7, and 14 after transplantation. The volume was measured and salivary cytokines were assessed using enzyme-linked immunosorbent assay.

RESULTS

By day 14, resting and stimulated salivary flow levels were diminished. Resting salivary flow rates decreased the most in the control and mechanical groups. In contrast, TENS alone or in combination with mechanical stimulatory therapy benefited the patients. TENS-treated patients showed increase in resting salivary flow. Also, the groups treated with TENS had fewer patients affected by grades 3 and 4 mucositis, and less mucositis was associated with better patient survival (P = .027).

CONCLUSIONS

TENS-associated salivary stimulation therapies minimized the reduction of salivary flow and prevented severe chemotherapy-induced oral mucositis.

Effect of the HIV nucleoside reverse transcriptase inhibitor zidovudine on the growth and differentiation of primary gingival epithelium

OBJECTIVES

Oral complications associated with HIV infection and with the antiretroviral drugs used to treat it are of increasing concern in HIV-infected patients. Protease inhibitors have been shown to change the proliferation and differentiation state of oral tissues but the effect of nucleoside reverse transcriptase inhibitors is currently unknown. This study examined the effect of zidovudine on the growth and differentiation of the gingival epithelium.

METHODS

Gingival keratinocyte organotypic (raft) cultures were established. The raft cultures were treated with a range of zidovudine concentrations. Haematoxylin and eosin staining was performed to examine the effect of zidovudine on gingival epithelium growth and stratification. Raft cultures were immunohistochemically analysed to determine the effect of this drug on the expression of key differentiation and proliferation markers, including cytokeratins and proliferating cell nuclear antigen (PCNA).

RESULTS

Zidovudine dramatically changed the proliferation and differentiation state of gingival tissues both when it was present throughout the growth period of the tissue and when it was added to established tissue at day 8. Zidovudine treatment increased the expression of cytokeratin 10, PCNA and cyclin A. Conversely, cytokeratin 5, involucrin and cytokeratin 6 expression was decreased. The tissue exhibited characteristics of increased proliferation in the suprabasal layers as well as an increased fragility and an inability to heal itself.

CONCLUSIONS

Zidovudine treatment, even when applied at low concentrations for short periods of time, deregulated the cell cycle/proliferation and differentiation pathways, resulting in abnormal epithelial repair and proliferation. Our system could potentially be developed as a model for studying the effects of HIV and highly active antiretroviral therapy in vitro.

The HIV protease inhibitor lopinavir/ritonavir (Kaletra) alters the growth, differentiation and proliferation of primary gingival epithelium

OBJECTIVE

This study was designed to evaluate the effects of the HIV protease inhibitor lopinavir/ritonavir on gingival epithelium growth, integrity and differentiation.

METHODS

Organotypic (raft) cultures of gingival keratinocytes were established and treated with a range of lopinavir/ritonavir concentrations. To examine the effect of lopinavir/ritonavir on gingival epithelium growth and stratification, haematoxylin and eosin staining was performed. To investigate the effect of this drug on tissue integrity, transmission electron microscopy (TEM) was performed on untreated and drug-treated tissues. Further, immunohistochemical analysis of raft cultures was performed to assess the effect of lopinavir/ritonavir on the expression of key differentiation and proliferation markers including cytokeratins, proliferating cell nuclear antigen (PCNA) and cyclin A.

RESULTS

Lopinavir/ritonavir treatments drastically inhibited the growth of gingival epithelium when the drug was present throughout the growth period of the tissue. When the drug was added on day 8 of tissue growth, lopinavir/ritonavir treatments compromised tissue integrity over time and altered the proliferation and differentiation of gingival keratinocytes. Expression of cytokeratins 5, 14, 10 and 6, PCNA and cyclin A was induced, and their expression patterns were also altered over time in treated rafts.

CONCLUSIONS

The findings of our studies suggest that lopinavir/ritonavir treatments compromised tissue integrity over time and deregulated the cell cycle/proliferation and differentiation pathways, resulting in abnormal epithelial repair and proliferation. Our study provides a model of potential utility in studying the effects of antiretroviral drugs in vitro.

Effect of the HIV protease inhibitor amprenavir on the growth and differentiation of primary gingival epithelium

BACKGROUND

HIV-positive patients taking antiretroviral drugs, including protease inhibitors, have shown a significant increase in the development of oral complications; these complications are a major health issue for affected patients. The effect of these drugs on oral epithelium growth and differentiation is presently unknown. In this study, we explore for the first time the effect of the HIV protease inhibitor amprenavir on gingival epithelium growth and differentiation.

METHODS

Organotypic (raft) cultures of gingival keratinocytes were established and the raft cultures treated with a range of amprenavir concentrations. Haematoxylin and eosin staining was performed to examine the effect of amprenavir on gingival epithelium growth and stratification. The raft cultures were also immunohistochemically analysed to determine the effect of amprenavir on the expression of key differentiation and proliferation markers, including cytokeratins, proliferating cell nuclear antigen (PCNA) and cyclin A.

RESULTS

Amprenavir severely inhibited the growth of gingival epithelium when the drug was present throughout the growth period of the tissue. When the drug was added at day 8, amprenavir treatment altered the proliferation and differentiation of gingival keratinocytes. Expression of the cytokeratins 5, 14, 6 and 10, PCNA and cyclin A was increased; their expression pattern was also altered over time in treated rafts. Biochemically, the tissue exhibited characteristics of increased proliferation in the suprabasal layers of amprenavir-treated tissue.

CONCLUSIONS

Our results suggest that amprenavir treatment deregulates the cell cycle/proliferation and differentiation pathways, resulting in abnormal epithelial repair and proliferation. Our system could be developed as a potential model for studying the effects of highly active antiretroviral therapy in vitro.