Single nucleotide polymorphisms conferring susceptibility to leukemia and oral mucositis: a multi-center pilot study of patients prior to conditioning therapy for hematopoietic cell transplant

PURPOSE

Leukemias have been associated with oral manifestations, reflecting susceptibility to cancer therapy-induced oral mucositis. We sought to identify SNPs associated with both leukemia and oral mucositis (OM).

METHODS

Whole exome sequencing was performed on leukemia and non-cancer blood disorder (ncBD) patients' saliva samples (N = 50) prior to conditioning therapy. WHO OM grading scores were determined: moderate to severe (OM2-4) vs. none to mild (OM0-1). Reads were processed using Trim Galorev0.6.7, Bowtie2v2.4.1, Samtoolsv1.10, Genome Analysis Toolkit (GATK)v4.2.6.1, and DeepVariantv1.4.0. We utilized the following pipelines: P1 analysis with PLINK2v3.7, SNP2GENEv1.4.1 and MAGMAv1.07b, and P2 [leukemia (N = 42) vs. ncBDs (N = 8)] and P3 [leukemia + OM2-4 (N = 18) vs. leukemia + OM0-1 (N = 24)] with Z-tests of genotypes and protein-protein interaction determination. GeneCardsSuitev5.14 was used to identify phenotypes (P1 and P2, leukemia; P3, oral mucositis) and average disease-causing likelihood and DGIdb for drug interactions. P1 and P2 genes were analyzed with CytoScape plugin BiNGOv3.0.3 to retrieve overrepresented Gene Ontology (GO) terms and Ensembl's VEP for SNP outcomes.

RESULTS

In P1, 457 candidate SNPs (28 genes) were identified and 21,604 SNPs (1016 genes) by MAGMAv1.07b. Eighteen genes were associated with "leukemia" per VarElectv5.14 analysis and predicted to be deleterious. In P2 and P3, 353 and 174 SNPs were significant, respectively. STRINGv12.0 returned 77 and 32 genes (C.L. = 0.7) for P2 and P3, respectively. VarElectv5.14 determined 60 genes from P2 associated with "leukemia" and 11 with "oral mucositis" from P3. Overrepresented GO terms included "cellular process," "signaling," "hemopoiesis," and "regulation of immune response."

CONCLUSIONS

We identified candidate SNPs possibly conferring susceptibility to develop leukemia and oral mucositis.

Genetic Polymorphisms of XPC, XPD, XPG Genes and their Association with Radiotherapy Induced Toxicity among Head and Neck Cancer Patients: A Hospital Based Study from Maharashtra

BACKGROUND

The present study was planned to investigate possible association of single nucleotide polymorphisms (SNPs) of nucleotide excision repair (NER) genes such as XPC, XPD, XPG with acute radiation induced toxicities such as skin reactions and oral mucositis in normal tissue from head and neck cancer (HNC) patients receiving radiotherapy.  Methods: Two hundred and fifty HNC patients receiving radiotherapy were enrolled in this study and the acute toxicity reactions and radiation response were recorded. Association of SNPs rs2228001 of XPC, rs238406, rs13181 of XPD and rs17655 of XPG gene with normal tissue reactions in the form of dermatitis and mucositis were studied by PCR-RFLP and direct DNA sequencing.

RESULTS

The results of univariate analysis of SNPs of XPC, XPD and XPG showed that XPC polymorphism at codon 939 of exon 15 (A>C) was not associated with dermatitis (OR=0.30, 95% CI: 0.06-1.39; p=0.125), or oral mucositis (OR=1.14, 95% CI: 0.41-3.20; p=0.793). The XPD codon 156 of exon 6 (C>A) and codon 751 of exon-23 A>C) polymorphism showed no association with radiosensitivity in HNC patients (OR=1.50, 95% CI: 0.60-3.71; p=0.080) for dermatitis, (OR=1.54, 95% CI: 0.66-3.61; p=0.312) for oral mucositis. The 1104 Asp variant genotype or allele of XPG (OR=1.35 95% CI: 0.50-3.64; p=0.541) showed no association with degree of radiotherapy associated dermatitis or mucositis (OR=0.80, 95% CI: 0.32-2.03; p=0.648) in HNC patients. The variant C allele of 2920 A/C genotype of XPC gene at codon 939 of exon 15, found protective with developing skin reactions with grade >1 (OR=0.60, 95% CI: 0.36-0.97; p=0.039) in HNC patients treated with radiotherapy.

CONCLUSION

The results obtained in this study concluded that the SNPs rs2228001of XPC, rs238406, rs13181 SNPs of XPD and rs17655 SNP of XPG are not associated with normal tissue toxicity in HNC patients treated with radiotherapy. Radiotherapy with high radiation dose was significantly associated with oral mucositis in response to radiotherapy.

Polymorphism but not methylation status in the vitamin D receptor gene contributes to oral mucositis in children

OBJECTIVE

To investigate the relationship between the polymorphisms rs1544410 (BsmI), rs2228570 (FokI) and rs731236 (TaqI) and DNA methylation status in the VDR gene (vitamin D receptor) with oral mucositis (OM) in oncopaediatric patients treated with methotrexate (MTX®).

METHODS

The population comprised healthy patients with haematological malignancies aged between 5 and 19 years. An evaluation of oral conditions was performed using the Oral Assessment Guide. Demographic, clinical, biochemical and haematological data were obtained from medical records. Genomic DNA from oral mucosal cells was used for the analysis of polymorphisms (n = 102) (PCR-restriction fragment length polymorphism) and DNA methylation (n = 81) (methylation-specific PCR).

RESULTS

Males predominated (57.8%), and the mean age was 10.3 years (±4.7). OM affected 84.3% of patients, of which 53.1% developed severe oral mucositis (SOM). Patients with OM had lower platelet and leukocyte counts (p < 0.05). The G allele of rs1544410 (p = 0.040) and the CT genotype of rs2228570 polymorphisms were associated with SOM (p = 0.038). A partially methylated status in the VDR promoter was found in all patients.

CONCLUSION

OM is associated with lower leukocyte and platelet counts. SOM is associated with the rs1544410 and rs2228570 polymorphisms. The methylation status of the VDR is not associated with inflammation or exposure to MTX®.

Transcriptomic signatures of feline chronic gingivostomatitis are influenced by upregulated IL6

Feline chronic gingivostomatitis (FCGS) is a relatively common and debilitating disease characterized by bilateral inflammation and ulceration of the caudal oral mucosa, alveolar and buccal mucosa, and varying degrees of periodontal disease. The etiopathogenesis of FCGS remains unresolved. In this study, we performed bulk RNA-seq molecular profiling of affected tissues derived from a cohort of client-owned cats with FCGS compared to tissues from unaffected animals, to identify candidate genes and pathways that can help guide future exploration of novel clinical solutions. We complemented transcriptomic findings with immunohistochemistry and in situ hybridization assays to better understand the biological significance of the results and performed RNA-seq validation of biologically relevant differentially expressed genes using qPCR assays to demonstrate technical reproducibility. Transcriptomic profiles of oral mucosal tissues in cats with FCGS are enriched with immune- and inflammation-related genes and pathways that appear to be largely influenced by IL6, and include NFKB, JAK/STAT, IL-17 and IFN type I and II signaling, offering new opportunities to develop novel clinical applications based on a more rational understanding of the disease.

Study of the Possible Alleviated Role of Atorvastatin on Irinotecan-Induced Lingual Mucosal Damage: Histological and Molecular Study

BACKGROUND

Oral mucositis is the most debilitating and troublesome adverse effect of irinotecan (CPT-11) treatment. It adversely affects the patient quality of life. The aim of this work was to study the histological, immunohistochemical, and molecular changes in the oral mucosa by CPT-11 and the possible alleviated role of atorvastatin.

METHODS

Rats were randomly divided into control, CPT-11-treated group, and CPT-11+ atorvastatin-treated group. At the end of the experiment, the anterior two-thirds of the tongue was dissected out and divided into two parts: one part for light microscopic examination and the second for molecular study.

RESULTS

CPT-11-treated group revealed loss of normal mucosal organization, areas of ulceration and inflammation, and loss of architecture of lingual papillae. A significant decrease in immunohistochemical and molecular gene expression of Ki-67 and antiapoptotic Bcl-2 levels was observed. A significant increase in NF-κB immunohistochemical and mRNA gene expression level and a nonsignificant increase in Nrf2 gene expression were detected. Coadministration of atorvastatin showed remarkable improvement in the histopathological picture with a significant increase in Ki-67 and Bcl-2, a significant decrease in NF-κB protein and gene expression, and a significant increase in Nrf2 gene expression.

CONCLUSION

Atorvastatin substantially attenuates CPT-11-induced oral mucositis through the initiation of the antiapoptotic gene, modulation of the inflammatory, and antioxidant gene expression.

Tissue Damage in Radiation-Induced Oral Mucositis Is Mitigated by IL-17 Receptor Signaling

Oral mucositis (OM) is a treatment-limiting adverse side effect of radiation and chemotherapy. Approximately 80% of patients undergoing radiotherapy (RT) for head and neck cancers (HNC) develop OM, representing a major unmet medical condition. Our understanding of the immunopathogenesis of OM is limited, due in part to the surprising paucity of information regarding healing mechanisms in the oral mucosa. RNAseq of oral tissue in a murine model that closely mimics human OM, showed elevated expression of IL-17 and related immune pathways in response to head and neck irradiation (HNI). Strikingly, mice lacking the IL-17 receptor (IL-17RA) exhibited markedly more severe OM. Restoration of the oral mucosa was compromised in Il17ra-/- mice and components associated with healing, including matrix metalloproteinase 3, 10 and IL-24 were diminished. IL-17 is typically associated with recruitment of neutrophils to mucosal sites following oral infections. Unexpectedly, in OM the absence of IL-17RA resulted in excessive neutrophil recruitment and immunopathology. Instead, neutrophil activation was IL-1R-driven in Il17ra-/- mice. Blockade of IL-1R and depletion of neutrophils lessened the severity of damage in these mice. Overall, we show IL-17 is protective in OM through multiple mechanisms including restoration of the damaged epithelia and control of the neutrophil response. We also present a clinically relevant murine model of human OM to improve mechanistic understanding and develop rational translational therapeutics.

The inflammation-reducing compatible solute ectoine does not impair the cytotoxic effect of ionizing radiation on head and neck cancer cells

Ectoine is a natural protectant expressed by halophile bacteria to resist challenges of their natural environments, such as drought, heat or high salt concentrations. As a compatible solute, ectoine does not interfere with the cell's metabolism even at high molar concentrations. External application of ectoine results in surface hydration and membrane stabilization. It can reduce inflammation processes and was recently tested in a pilot study for the prevention and treatment of chemotherapy-induced oral mucositis. Oral mucositis is especially frequent and severe in patients with head and neck squamous cell carcinoma (HNSCC), who receive radiotherapy or chemoradiation. It is extremely painful, can limit nutritional intake and may necessitate treatment interruptions, which can critically compromise outcome. As it was recently reported that in vitro ectoine has the ability to protect DNA against ionizing irradiation, it was the aim of this study to test whether ectoine may protect HNSCC cells from radiotherapy. Using HNSCC cell lines and primary human fibroblasts, we can show that in living cells ectoine does not impair DNA damage induction and cytotoxicity through ionizing radiation. We therefore conclude that testing the ectopic application of ectoine for its ability to alleviate early radiotherapy/chemoradiation-induced side effects is safe and feasible.

Prevalence of p53 dysregulations in feline oral squamous cell carcinoma and non-neoplastic oral mucosa

Squamous cell carcinoma is the most common malignant oral tumor in cats. The late presentation is one of the factors contributing to the detrimental prognosis of this disease. The immunohistochemical expression of the p53 tumor suppressor protein has been reported in 24% to 65% of feline oral squamous cell carcinomas, but no study has systematically evaluated in this tumor the presence of p53 encoding gene (TP53) mutations. The aim of this retrospective study was to determine whether p53 immunohistochemistry accurately reflects the mutational status of the TP53 gene in feline oral squamous cell carcinoma. Additionally, the prevalence of p53 dysregulation in feline oral squamous cell carcinoma was compared with that of feline non-neoplastic oral mucosa, in order to investigate the relevance of these dysregulations in cancer development. The association between p53 dysregulations and exposure to environmental tobacco smoke and tumor characteristics was further assessed. Twenty-six incisional biopsies of oral squamous cell carcinomas and 10 cases each of lingual eosinophilic granuloma, chronic gingivostomatitis and normal oral mucosa were included in the study. Eighteen squamous cell carcinomas (69%) expressed p53 and 18 had mutations in exons 5-8 of TP53. The agreement between immunohistochemistry and mutation analysis was 77%. None of non-neoplastic oral mucosa samples had a positive immunohistochemical staining, while one case each of eosinophilic granuloma and chronic gingivostomatitis harbored TP53 mutations. Unlike previously hypothesized, p53 dysregulations were not associated with exposure to environmental tobacco smoke. These results suggest an important role of p53 in feline oral tumorigenesis. Additionally, the immunohistochemical detection of p53 expression appears to reflect the presence of TP53 mutations in the majority of cases. It remains to be determined if the screening for p53 dysregulations, alone or in association with other markers, can eventually contribute to the early detection of this devastating disease.

Dose intensity and efficacy of the combination of everolimus and exemestane (EVE/EXE) in a real-world population of hormone receptor-positive (ER+/PgR+), HER2-negative advanced breast cancer (ABC) patients: a multicenter Italian experience

AIM

This retrospective analysis focused on the effect of treatment with EVE/EXE in a real-world population outside of clinical trials. We examined the efficacy of this combination in terms of PFS and RR related to dose intensity (5 mg daily versus 10 mg daily) and tolerability.

METHODS

163 HER2-negative ER+/PgR+ ABC patients, treated with EVE/EXE from May 2011 to March 2016, were included in the analysis. The primary endpoints were the correlation between the daily dose and RR and PFS, as well as an evaluation of the tolerability of the combination. Secondary endpoints were RR, PFS, and OS according to the line of treatment. Patients were classified into three different groups, each with a different dose intensity of everolimus (A, B, C).

RESULTS

RR was 29.8% (A), 27.8% (B) (p = 0.953), and not evaluable (C). PFS was 9 months (95% CI 7-11) (A), 10 months (95% CI 9-11) (B), and 5 months (95% CI 2-8) (C), p = 0.956. OS was 38 months (95% CI 24-38) (A), median not reached (B), and 13 months (95% CI 10-25) (C), p = 0.002. Adverse events were stomatitis 57.7% (11.0% grade 3-4), asthenia 46.0% (6.1% grade 3-4), hypercholesterolemia 46.0% (0.6% grade 3-4), and hyperglycemia 35.6% (5.5% grade 3-4). The main reason for discontinuation/interruption was grade 2-3 stomatitis.

CONCLUSIONS

No correlation was found between dose intensity (5 vs. 10 mg labeled dose) and efficacy in terms of RR and PFS. The tolerability of the higher dose was poor in our experience, although this had no impact on efficacy.

Molecular Characteristics of High-Dose Melphalan Associated Oral Mucositis in Patients with Multiple Myeloma: A Gene Expression Study on Human Mucosa

Background

Toxicity of the oral and gastrointestinal mucosa induced by high-dose melphalan is a clinical challenge with no documented prophylactic interventions or predictive tests. The aim of this study was to describe molecular changes in human oral mucosa and to identify biomarkers correlated with the grade of clinical mucositis.

Methods and Findings

Ten patients with multiple myeloma (MM) were included. For each patient, we acquired three buccal biopsies, one before, one at 2 days, and one at 20 days after high-dose melphalan administration. We also acquired buccal biopsies from 10 healthy individuals that served as controls. We analyzed the biopsies for global gene expression and performed an immunohistochemical analysis to determine HLA-DRB5 expression. We evaluated associations between clinical mucositis and gene expression profiles. Compared to gene expression levels before and 20 days after therapy, at two days after melphalan treatment, we found gene regulation in the p53 and TNF pathways (MDM2, INPPD5, TIGAR), which favored anti-apoptotic defense, and upregulation of immunoregulatory genes (TREM2, LAMP3) in mucosal dendritic cells. This upregulation was independent of clinical mucositis. HLA-DRB1 and HLA-DRB5 (surface receptors on dendritic cells) were expressed at low levels in all patients with MM, in the subgroup of patients with ulcerative mucositis (UM), and in controls; in contrast, the subgroup with low-grade mucositis (NM) displayed 5–6 fold increases in HLA-DRB1 and HLA-DRB5 expression in the first two biopsies, independent of melphalan treatment. Moreover, different splice variants of HLA-DRB1 were expressed in the UM and NM subgroups.

Conclusions

Our results revealed that, among patients with MM, immunoregulatory genes and genes involved in defense against apoptosis were affected immediately after melphalan administration, independent of the presence of clinical mucositis. Furthermore, our results suggested that the expression levels of HLA-DRB1 and HLA-DRB5 may serve as potential predictive biomarkers for mucositis severity.

Comprehensive Assessment of Host Responses to 5-Fluorouracil-Induced Oral Mucositis through Transcriptomic Analysis

Background

Chemotherapy plays an important role in current cancer therapy; however, several problems remain unsolved on the issue of host-therapeutics interaction. The purpose of this study was to investigate the host responses after 5-flurouracil (5-FU) administration and to find the target genes and their relationship with other cytokines in the 5-FU-induced oral mucositis (OM) mouse model through transcriptomic analysis.

Materials and Methods

Thirty-six 6 to 8 week-old male BALB/c mice were randomly divided into the control group and 5-FU-treated group. In the 5-FU group, mice received 5-FU (100 mg/kg, intraperitoneally) on day 1, day 8, day 15, day 22, and day 29, respectively. We evaluated the oral mucosal change under macroanalysis and histological examination at indicated periods, and then applied transcriptomic analysis of gene expression profile and Immunohistochemical stain to identify the target molecules related to 5-FU-induced OM.

Results

The most prominent histological change in this model was observed in the fifth week. The gene expression of Bone gamma-carboxyglutamate protein, related sequence 1 (Bglap-rs1) (–12.69-fold) and Chitinase 3-like 4 (Chi3l4) (–6.35-fold) were significantly down-regulated in this phase. The quantitative real-time PCR results also revealed the expression levels were 0.62-fold in Bglap-rs1 and 0.13-fold in Chi3l4 compared with the control group. Immunohistochemical stain showed significant expression of cluster of differentiation 11b (p<0.01), interleukin-1β (p<0.001) and tumor necrosis factor-α (p<0.05), and down-regulation of Bglap-rs1 (p<0.01) compared with the control group. By Kyoto Encyclopedia of Genes and Genomes pathway analysis, there were twenty-three pathways significantly participated in this study (p<0.05).

Conclusions

Through comprehensively transcriptomic analysis and IHC stain, we discovered several valuable pathways, verified the main pro-inflammatory cytokines, and revealed two significantly down-regulated genes in the 5-FU-induced OM model. These findings highlighted the way of seeking effective therapeutic agents for chemotherapy-induced OM in future.

S-nitrosoglutathione accelerates recovery from 5-fluorouracil-induced oral mucositis

Introduction

Mucositis induced by anti-neoplastic drugs is an important, dose-limiting and costly side-effect of cancer therapy.

Aim

To evaluate the effect of the topical application of S-nitrosoglutathione (GSNO), a nitric oxide donor, on 5-fluorouracil (5-FU)-induced oral mucositis in hamsters.

Materials and Methods

Oral mucositis was induced in male hamsters by two intraperitoneal administrations of 5-FU on the first and second days of the experiment (60 and 40 mg/kg, respectively) followed by mechanical trauma on the fourth day. Animals received saline, HPMC or HPMC/GSNO (0.1, 0.5 or 2.0 mM) 1 h prior to the 5-FU injection and twice a day for 10 or 14 days. Samples of cheek pouches were harvested for: histopathological analysis, TNF-α and IL-1β levels, immunohistochemical staining for iNOS, TNF-α, IL-1β, Ki67 and TGF-β RII and a TUNEL assay. The presence and levels of 39 bacterial taxa were analyzed using the Checkerboard DNA-DNA hybridization method. The profiles of NO released from the HPMC/GSNO formulations were characterized using chemiluminescence.

Results

The HPMC/GSNO formulations were found to provide sustained release of NO for more than 4 h at concentration-dependent rates of 14 to 80 nmol/mL/h. Treatment with HPMC/GSNO (0.5 mM) significantly reduced mucosal damage, inflammatory alterations and cell death associated with 5-FU-induced oral mucositis on day 14 but not on day 10. HPMC/GSNO administration also reversed the inhibitory effect of 5-FU on cell proliferation on day 14. In addition, we observed that the chemotherapy significantly increased the levels and/or prevalence of several bacterial species.

Conclusion

Topical HPMC/GSNO accelerates mucosal recovery, reduces inflammatory parameters, speeds up re-epithelization and decreases levels of periodontopathic species in mucosal ulcers.

Hyperpolarization-activated cyclic nucleotide-gated 2 (HCN2) polymorphism is associated with chronic inflammatory periodontitis. A cross-sectional study

BACKGROUND

Chronic periodontitis (CP) and peri-implantitis (PI) are inflammatory diseases that affect supporting tissues of teeth or implants. The involvement of hyperpolarization-activated cyclic nucleotide-gated 2 (HCN2) in neuronal excitability, hyperalgesia, allodynia, spontaneous pain, synaptic plasticity, and rebound activity was previously determined. Recently, scientists found that HCN2 plays an important role in chronic inflammatory pain. This study aimed to evaluate the relationship between gene polymorphisms of HCN2 and CP/PI.

METHODS

A total of 74 patients with CP, 37 patients with PI, and 80 healthy controls presenting to the Periodontology Department of Shahid Beheshti University of Medical Sciences were enrolled. DNA was extracted from fresh blood samples of the arm vein of participants and transferred to KBioscience Institute (UK) for genotyping. χ2-test was performed with SPSS software v.19 for statistical analyses. A p value <0.05 was considered significant.

RESULTS

Both rs55687900 and rs148730222 had significant differences in genotype frequencies between CP and healthy groups (p=0.005 and 0.006, respectively). The allele frequencies also revealed significant frequencies (p=0.004 and 0.006, respectively). The comparison of genotype and allele frequencies between PI and healthy groups had no significant difference.

CONCLUSIONS

HCN2 polymorphism may play a role in CP but not in PI. Despite this approval, more studies with larger sample sizes in different populations are necessary.

Microarray analyses of oral punch biopsies from acute myeloid leukemia (AML) patients treated with chemotherapy

OBJECTIVE

Understanding the pathogenesis of chemotherapy-induced oral mucositis (CIOM) is vital to develop therapies for this common, dose-limiting side effect of cancer treatment. We investigated molecular events in CIOM from buccal mucosa tissue collected before and 2 days after chemotherapy from patients with acute myeloid leukemia (AML) and healthy controls by microarray analysis.

METHODS

Microarray analysis was performed using Human Genome U133 Plus 2.0 Array on buccal mucosa punch biopsies from patients with AML before (n = 4) or after chemotherapy (n = 4), and from healthy controls (n = 3). Following Robust Multichip Average (RMA) normalization, we applied Linear Models for Microarray data (LIMMA) and Significance Analysis of Microarrays (SAM) for data analysis using the TM4/TMeV v4.5.1 program.

RESULTS

LIMMA and SAM identified genes potentially affected by the presence of AML, including homeodomain-interacting protein kinase 1 (HIPK1), mex-3 homolog D (MEX3D), and genes potentially affected by chemotherapy, including argininosuccinate synthase 1 (ASS1), notch homolog 1 (NOTCH1), zinc transporter ZIP6 (SLC39A6), and TP53-regulated inhibitor of apoptosis 1 (TRIAP1). The expression of 2 genes with potential biological significance in oral mucositis, ASS1 and SLC39A6 (alias LIV-1), was confirmed by quantitative real-time reverse transcriptase-polymerase chain reaction (qRT-PCR).

CONCLUSIONS

Our results suggest that AML-specific deregulated immune responses and inflammatory tissue damage to the oral mucosa caused by chemotherapy may not be overcome by the natural cellular repair processes and therefore contribute to CIOM.

Decreased expression of p63 in oral lichen planus and graft-vs.-host disease associated with oral inflammation

BACKGROUND

Oral lichen planus (OLP) and graft-vs.-host disease (GVHD) are conditions with increased risk of malignant transformation to squamous cell carcinoma of the head and neck (SCCHN). The p63 gene encodes six different proteins and is expressed at high levels in SCCHN.

METHODS

Biopsies from patients diagnosed with OLP and GVHD were analysed for p63 protein expression using antibodies distinguishing between the major isoforms expressed in normal epithelia, in parallel with biopsies from normal buccal mucosa and SCCHN.

RESULTS

In OLP and GVHD a decreased expression of all p63 isoforms was seen, while expression of p53 protein was upregulated, compared with normal mucosa. In SCCHN, p63 was abundantly expressed and some tumours showed strong p53 staining, suggestive of p53 mutation.

CONCLUSIONS

Decreased p63 and increased p53 expression in OLP and GVHD indicates a coordinated action of these two related proteins to protect the oral mucosae from the damaging effects of underlying inflammation. In SCCHN disruption of the TP53 gene and overrepresentation of certain p63 isoforms has been seen, indicating that this could lead to neoplastic transformation.

A biological approach to mucositis

Oral mucositis is a common toxicity associated with both antineoplastic head and neck radiation and chemotherapy. In addition to exacting a terrible symptomatic toll, mucositis is associated with a number of adverse health and economic outcomes. Furthermore, its presence may compromise the use of optimum agents, doses, or dosing schedules. The current lack of an approved, effective mucositis treatment has sparked interest in the development of interventions that are based on the biological mechanisms that lead to mucosal injury. While our understanding of the molecular and cellular pathways leading to mucositis is still evolving, it is now clear that the condition represents the culmination of a dynamic sequence of events that involve all cells and tissues in the mucosa. Five phases characterize the pathophysiologic progression that results in mucositis: initiation, upregulation and message generation, signaling and amplification, ulceration, and healing. Each phase offers a potential target for therapeutic intervention.

The gene expression sequence of radiated mucosa in an animal mucositis model

Oral mucositis is a common, dose-limiting, acute toxicity of radiation therapy administered for the treatment of cancers of the head and neck. Accumulating data would suggest that the pathogenesis of mucositis is complex and involves the sequential interaction of all cell types of the oral mucosa, as well as a number of cytokines and elements of the oral environment. While a number of studies have reported on gene expression of particular cell types in response to radiation, the overall response of irradiated mucosa has only been evaluated in a limited way. The present study was undertaken to evaluate the expression of a target group of genes using RNA quantification assays and, more broadly, to assess patterns of mucosal gene expression using DNA microarray hybridization. Our results demonstrate the sequential upregulation of a series of genes that, when taken collectively, suggest an intricate functional interaction.

Expression of the proto-oncogene eIF4E in inflammation of the oral cavity

OBJECTIVE

eIF4E (4E) is elevated in 100% of head and neck squamous cell carcinoma (HNSCC) and in premalignant lesions of the larynx. However, it is not elevated in normal mucosa. In this study, we hypothesize that 4E is not significantly elevated in inflammation unlike its expression in premalignant lesions of the oral cavity.

STUDY DESIGN

Biopsies from the oral cavity were divided into 5 groups: (1) normal mucosa, (2) chronic inflammation, (3) mild dysplasia from leukoplakic lesions, (4) mild dysplasia in surgical margins of patients with HNSCC, and (5) HNSCC. Immunohistochemical qualitative analysis was then performed.

RESULTS

None of the 15 specimens in group 1 and 100% of the 15 specimens in group 5 expressed 4E. Of the 29 specimens in group 2 only 4/29 (13%) overexpressed 4E compared with 10/31 (32%) in group 3 and 9/21 (42%) in group 4. There was a significant difference between groups 2 and 3 and groups 2 and 4 (P < 0.0001 and P < 0.003 respectively) but no significant difference between groups 1 and 2 (P = 0.13) and between groups 3 and 4 (P = 0.30).

CONCLUSION

4E is not significantly elevated in inflammation of the oral cavity thus fulfilling one of the criteria that biomarkers require to be useful in a clinical setting.

Pharmacogenetics of methotrexate: toxicity among marrow transplantation patients varies with the methylenetetrahydrofolate reductase C677T polymorphism

This study investigated whether a polymorphism in the 5,10-methylenetetrahydrofolate reductase (MTHFR) gene (C677T) modifies responses to methotrexate (MTX) in patients undergoing bone marrow transplantation. About 10% to 12% of the population carry the MTHFR TT genotype (enzyme activity, 30% of wild type [CC]). Patients (n = 220) with chronic myelogenous leukemia underwent marrow allografts and were given a short course of MTX. MTX toxicity measures included the oral mucositis index (OMI), speed of engraftment (platelet and granulocyte counts), and bilirubin. Patients with lower MTHFR activity (TT genotype) had 36% higher mean OMI during days 1 to 18 (+5.7, P =.046) and 20% higher OMI between days 6 and 12 (+3.8, P =.27). Platelet counts recovered more slowly among patients with the TT genotype compared to wild type (24% slower recovery to 10 000 platelets/microL, P =.23; 34% slower to 20 000/microL, P =.08). Patients with decreased MTHFR activity appear at risk of higher MTX toxicity. Because of the high prevalence of the TT genotype, these results may have implications for MTX dosage.

Cytokine mRNA expression in lesions in cats with chronic gingivostomatitis

Semiquantitative reverse transcription-PCR assays were developed to measure feline interleukin-2 (IL-2), IL-4, IL-5, IL-6, IL-10, and IL-12 (p35 & p40); gamma interferon (IFN-gamma); and glyceraldehyde-3-phosphate dehydrogenase mRNA concentrations in biopsies of feline oral mucosa. Biopsies were collected from 30 cats with chronic gingivostomatitis (diseased) prior to each cat receiving one of four treatments. In 23 cases replicate biopsies were collected 3 months after treatment commenced. Biopsies were also analyzed from 11 cats without clinical disease (nondiseased). Expression of IL-2, IL-10, IL-12 (p35 and p40), and IFN-gamma was detected in most nondiseased biopsies, while IL-6 was detected in a minority, and IL-4 and IL-5 were both undetectable. Compared to nondiseased cats, the diseased population showed a significant increase in the relative mRNA expression of IL-2, IL-4, IL-6, IL-10, IL-12 (p35 and p40), and IFN-gamma. In contrast, IL-5 mRNA expression was unchanged and was only detected in one case. No significant relationship was demonstrable between the change in relative expression of specific cytokine mRNA and the change in clinical severity of the local mucosal lesions over the treatment period. The results demonstrate that the normal feline oral mucosa is biased towards a predominantly (Th) type 1 profile of cytokine expression and that during the development of lesions seen in feline chronic gingivostomatitis there is a shift in the cytokine profile from a type 1 to a mixed type 1 and type 2 response.

Inhibition of host RNA polymerase II-dependent transcription by vesicular stomatitis virus results from inactivation of TFIID

During infection with vesicular stomatitis virus (VSV), host-cell mRNA synthesis is inhibited due to shut off of host-cell transcription. The transcriptional activity of nuclear extracts prepared from VSV-infected cells was compared to the activity of nuclear extracts from uninfected cells. An exogenous DNA template was used which contained an adenovirus major late promoter (AdMLP) but lacked upstream activating sequences, so that only basal transcription activity was assayed in these experiments. AdMLP-initiated transcription was decreased by 75% in nuclear extracts from infected cells as early as 3 h p.i. and by >90% by 6 h p.i. Mixing nuclear extracts from uninfected and VSV-infected cells revealed that the inhibition was caused by lack of an active form of a host factor involved in basal transcription rather than by the presence of an excess of inhibitory factor. To determine which transcription factors were lacking from nuclear extracts of infected cells, host transcription initiation factors isolated from uninfected cells by ion-exchange chromatography were added separately to nuclear extracts inactivated by VSV infection. A phosphocellulose column fraction from uninfected cells eluted with 0. 8 M KCl, which contained transcription factor IID (TFIID), overcame the inhibition. The corresponding fraction from infected cells had no detectable activity in a TFIID-dependent in vitro transcription assay. TATA-binding protein (TBP) is the DNA-binding subunit of TFIID and has been shown previously to substitute for TFIID in basal transcription. Purified recombinant TBP also reconstituted the transcription activity of nuclear extracts from infected cells, supporting the idea that TFIID is the target of virus-induced inhibition. Western blot analysis showed that the level of TBP in nuclear extracts or in the 0.8 M KCl column fraction was not changed by VSV infection. These results indicated that VSV infection leads to an inhibition of host transcription by inactivation of TFIID rather than reduction in the level of TFIID.

Overexpression of c-Src in areas of hyperproliferation in head and neck cancer, premalignant lesions and benign mucosal disorders

To examine which proteins are responsible for the elevated protein tyrosine kinase (PTK) activity in human head and neck squamous cell carcinoma (HNSCC) and adjacent histologically normal epithelium, paraffin embedded sections of these tissues were stained for PTK c-Src. Using double labeling techniques and antibodies against both the proliferation marker Ki-67 and PTK c-Src, we have shown that c-Src is overexpressed in areas of hyperproliferation in HNSCC, dysplastic epithelium, benign papillomas and inflamed normal tissue. Our data indicate that c-Src is (one of) the protein(s) responsible for the increased PTK activity in HNSCC. We could not demonstrate that c-Src expression is responsible for the increased PTK activity in normal epithelium adjacent to tumour tissue. We assume that c-Src plays a role in the increased proliferation seen in (pre)malignant and benign epithelial lesions as well as in reactive inflammatory epithelial hyperplasia.

Down-regulation of vesicular stomatitis virus transcription by the matrix protein of influenza virus

The matrix (M1) protein isolated from influenza A/WSN/33 virus, when reconstituted with ribonucleoprotein (RNP) cores of vesicular stomatitis virus (VSV), resulted in inhibition of VSV transcription in vitro. The presence of endogenous wild-type (wt) or mutant (tsO23) VSV matrix (M) protein on RNP cores did not prevent down-regulation of VSV transcription by reconstituted influenza virus M1 protein. In fact, endogenous VSV wt M protein augmented transcription inhibition by M1 protein reconstituted with RNP/M protein cores, whereas mutant tsO23 M protein endogenous to RNP cores had no effect on down-regulation of VSV transcription by M1 protein. These data suggest that VSV M protein and influenza virus M1 protein recognize two different sites on RNP cores responsible for down-regulation of VSV transcription. Monoclonal antibodies (MAbs) directed to epitope 2 of M1 protein had been previously shown to reverse transcription inhibition by M1 protein on influenza virus RNP cores, but the same epitope 2-specific MAb had little effect on transcription inhibition by M1 protein reconstituted with VSV RNP cores. VSV M protein bears a striking resemblance biologically and genetically to the M1 protein, including, as shown here, their capacity to bind viral RNA. However, the VSV wt M protein exhibited no capacity to down-regulate transcription by influenza virus RNP cores. The significance of these studies is the identification on VSV RNP templates of at least two separate sites for recognition of protein factors that repress VSV transcription.

Genetic analysis of resistance to lethal infections of vesicular stomatitis virus in Syrian hamsters

Vesicular stomatitis virus (VSV), Indiana serotype, causes a lethal disease in adult Syrian hamsters. Susceptibility to low doses of VSV (10 to 100 plaque-forming units) was shown to be genetically determined by examining six inbred strains. Three strains, LSH, MHA, and CB, were found to be extremely susceptible, with more than 70% of the animals dying within 72 h after intraperitoneal injection. Two strains, MIT and UT2, were intermediately susceptible, with approximately 60% of VSV-infected animals surviving. One strain, UT1, was found to be highly resistant; however, resistance was not acquired until the 4th or 5th week of age, and 100% of VSV-infected neonatal hamsters died. Analyses of F1 hybrid and segregant backcross populations derived from the LSH and UT1 strains suggested that at least three independent genetic loci contribute to phenotypic resistance. One locus resides on the X chromosome; the others reside on autosomes. No obvious linkage to the hamster major histocompatibility complex was detected. F1 hybrids of two highly susceptible strains, CB and MHA, were more resistant than either parental strain, suggesting that alleles of unlinked genes in the susceptible strains interact to produce a partially resistant phenotype. These alleles probably are the cause of the resistance phenotype found in the random-bred LVG strain which shares a common heritage with the CB and MHA strains.

[Naevus spongiosus albus mucosae. Review and personal observations]

White sponge nevus of the mucosa is a rare, mostly verifiable hereditary ectodermal dysplasia of the mucous membranes. Because associated symptoms of the skin are missing, it is classified as a distinctive disease among the congenital leukokeratoses. In the most cases the symptomless mucosal lesions are detected by dentological examination though they are present at birth or appear in the first years of life. On the basis of three own observations clinical appearance, histopathology, electronmicroscopy and differential diagnosis are discussed.

Cell-mediated immunity to vesicular stomatitis virus infections in mice

The T cell-mediated immune responses of mice against vesicular stomatitis virus (VSV) were assessed by measuring direct primary foot pad swelling after local VSV infection and cytotoxic activity in spleens. The cytolytic activity was mediated by T cells since it was anti-theta + complement sensitive, was restricted by the K and D region but not the I region of H-2 and rapidly increased after 4 days but decreased 8 days after systemic or local infection. Cytolytic activity was virus-specific as reciprocally tested with VSV and vaccina virus immune T cells. Measurable activity on day 7 depended on infectious virus dose, virus virulence, and non-H-2 genetic background of the host. More than half of the cytolytic activity wasblocked specifically by either immune anti-H2 or rabbit anti-VSV antisera. Analysis of the kinetics of appearance of antigenic changes using metabolic inhibitors, revealed that the changes that rendered target cells susceptible to lysis after infection, occurred within the first hour after infection.