Arecoline N-Oxide Upregulates Caspase-8 Expression in Oral Hyperplastic Lesions of Mice.

Areca nut is strongly associated with oral squamous cell carcinoma (OSCC) occurrence. Arecoline N-oxide (ANO), a metabolite of the areca alkaloid arecoline, exhibits an oral fibrotic effect in NOD/SCID mice. Caspase-8, a cysteine protease encoded by the CASP8 gene, is a central mediator in the extrinsic apoptotic pathway via death receptors. Deregulation of caspase-8 in OSCC has been reported. This study investigates the regulation of caspase-8 in ANO-induced oral squamous epithelial hyperplasia that represents the initial highly proliferative stage of oral carcinogenesis. CASP8 somatic mutations were identified from whole-exome sequencing of OSCC samples. Immunohistochemical staining showed upregulation of caspase-8 in ANO-induced hyperplasia of both NOD-SCID and C57BL/6 mice. Levels of expression of CASP8, APAF-1, BAX, and BAD increased in ANO-treated DOK cells. Co-localization of increased caspase-8 and PCNA levels was detected in ANO-induced hyperplastic lesions, whereas no co-localization among γ-H2A.X, caspase-3, and upregulated caspase-8 was observed. The findings indicate that upregulation of caspase-8 is involved in cell proliferation rather than apoptosis during the initial stage of ANO-mediated oral tumorigenesis.

Anti-inflammation performance of curcumin-loaded mesoporous calcium silicate cement.

BACKGROUND/PURPOSE: Calcium silicate (CS) cements have excellent bioactivity and can induce the bone-like apatite formation. They are good biomaterials for bone tissue engineering and bone regenerative medicine. However, they have degradability and the dissolved CS can cause the inflammatory response at the early post-implantation stage. The purpose of this study was to design and prepare the curcumin-loaded mesoporous CS (MesoCS/curcumin) cements as a strategy to reduce the inflammatory reaction after implantation. METHODS: The MesoCS/curcumin cements were designed and prepared. The characteristics of MesoCS/curcumin specimens were examined by transmission electron microscopy (TEM), X-ray diffraction (XRD) and scanning electron microscopy (SEM). Their physical properties, biocompatibility, and anti-inflammatory ability were also evaluated. RESULTS: The MesoCS/curcumin cements displayed excellent biocompatibility and physical properties. Their crystalline characterizations were very similar with MesoCS cements. After soaking in simulated body fluid, the bone-like apatite layer of the MesoCS/curcumin cements could be formed. In addition, it could inhibit the expression of tumor necrosis factor-α (TNF-α) and interleukin-1 (IL-1) after inflammation reaction induced by lipopolysaccharides and had good anti-inflammatory ability. CONCLUSION: Adding curcumin in MesoCS cements can reduce the inflammatory reaction, but does not affect the original biological activity and properties of MesoCS cements. It can provide a good strategy to inhibit the inflammatory reaction after implantation for bone tissue engineering and bone regenerative medicine.

Somatic Mutations and Genetic Variants of NOTCH1 in Head and Neck Squamous Cell Carcinoma Occurrence and Development.

A number of genetic variants have been associated with cancer occurrence, however it may be the acquired somatic mutations (SMs) that drive cancer development. This study investigates the potential SMs and related genetic variants associated with the occurrence and development of head and neck squamous cell carcinoma (HNSCC). We identified several SMs in NOTCH1 from whole-exome sequencing and validated them in a 13-year cohort of 128 HNSCC patients using a high-resolution melting analysis and resequencing. Patients who have NOTCH1 SMs show higher 5-year relapse-free recurrence (P = 0.0013) and lower survival proportion (P = 0.0447) when the risk-associated SMs were analysed by Cox proportional hazard models. Interestingly, the NOTCH1 gene rs139994842 that shares linkage with SMs is associated with HNSCC risk (OR = 3.46), increasing when SMs in NOTCH1 are involved (OR = 7.74), and furthermore when there are SMs in conjunction to betel quid chewing (OR = 32.11), which is a related independent environmental risk factor after adjusting for substances use (alcohol, betel quid, cigarettes) and age. The findings indicate that betel quid chewing is highly associated with NOTCH1 SMs (especially with changes in EGF-like domains), and that rs139994842 may potentially serve as an early predictive and prognostic biomarker for the occurrence and development of HNSCC.

AURKA Phe31Ile polymorphism interacted with use of alcohol, betel quid, and cigarettes at multiplicative risk of oral cancer occurrence.

OBJECTIVES: The expression levels of two DNA repair genes (CHAF1A and CHAF1B) and a chromosome segregation gene (AURKA) were susceptible to arecoline exposure, a major alkaloid of areca nut. We hypothesize that genetic variants of these genes might also be implicated in the risk of oral cancer and could be modified by substance use of betel quid or alcohol and cigarettes. MATERIAL AND METHODS: A case-control study, which included 507 patients with oral cancer and 717 matched controls, was performed in order to evaluate the cancer susceptibility by the tagging single-nucleotide polymorphisms (tagSNPs) in AURKA, CHAF1A, and CHAF1B using a genotyping assay and gene-environment interaction analysis. RESULTS: The Phe31Ile polymorphism (rs2273535, T91A) of AURKA was significantly associated with an increased risk of oral cancer (odds ratio (OR) = 2.1, 95% confidence interval (CI) 1.2-3.5). The gene dosage of the 91A allele also showed a significant trend in risk of oral cancer (P = 0.008). Furthermore, we found the AURKA 91AA homozygote was modifiable by substance use of alcohol, betel quid, and cigarettes (ABC), leading to increased risk of oral cancer in an additive or a multiplicative model (combined effect indexes = 1.2-4.0 and 1.5-2.2, respectively). However, no association was observed between the genetic variants of CHAF1A or CHAF1B and oral cancer risk in the study. CONCLUSION: These findings reveal the functional Phe31Ile polymorphism tagSNP of AURKA may be a strong susceptibility gene in ABC-related oral cancer occurrence. CLINICAL RELEVANCE: The results of this betel-related oral cancer study provide the evidence of environment-gene interaction for early prediction and molecular diagnosis.

Association between the polymorphisms in exon 12 of hypoxia-inducible factor-1alpha and the clinicopathological features of oral squamous cell carcinoma.

Oral squamous cell carcinoma (OSCC) is a common malignancy. The incidence of OSCC is particularly high in some Asian countries because of the popularity of the habit of chewing areca. Hypoxia-inducible factor-1alpha (HIF-1alpha) is up-regulated in the hypoxic microenvironment to enhance tumor survival. Five polymorphisms have been identified in exon 12 of HIF-1alpha including the C1772T polymorphism causing P582S, and the G1790A polymorphism causing A588T of the HIF-1alpha protein. This study investigated the relationship between these functional polymorphisms and the risk of progression of OSCC. PCR and direct sequencing were utilized to compare the genotypic polymorphism and allelic frequency of HIF-1alpha in 96 normal controls and 305 OSCC patients. No statistically significant difference in C1772T and G1790A genotypes and allelic frequency between control and OSCC patients was found. However, multivariate analysis indicated that the A carrier of HIF-1alpha G1790A in OSCC patients was significantly higher in larger tumors than in the contrasting group with an adjusted odds ratio of 2.92. The T carrier of HIF-1alpha C1772T in buccal cancer patients was significantly higher in the non-areca-chewing group with an adjusted odds ratio of 0.111. The buccal cancer patients with C1772T or G1790A had lower recurrence frequency with an odds ratio of 0.266. These findings may suggest a correlation between the HIF-1alpha C1772T and G1790A polymorphisms and the growth of OSCC, and the decrease of OSCC recurrence frequency.

Donor site morbidity after harvesting of proximal tibia bone.

BACKGROUND: Bone-grafting procedures are common in head and neck surgery. Donor site morbidity is an important factor in deciding the site for harvest of cancellous bone. The tibia has been recommended as a harvest site. Use of the proximal tibia as a donor site is associated with few complications. Our present study used proximal tibia bone grafts to reconstruct maxillofacial defects and augment bone volume for implantation. METHODS: A retrospective study was undertaken to analyze 40 proximal tibia bone grafts in maxillofacial reconstruction. Minimal follow-up was 6 months. RESULTS: There were no major complications during the follow-up period. Early minor complications (15%) included temporary sensory loss and ecchymosis. Late minor complication (2.5%) was gait disturbance for 2 months. Long-term minor complication (2.5%) was an unsightly scar. CONCLUSION: The procedure for proximal tibia bone graft is easy, has less operative risk, and results in a lower postoperative morbidity rate. Based on our findings, we believe the proximal tibia offers a reliable site for harvest of sufficient quantities of good-quality cancellous bone.