Ingenuity pathway analysis of gingival epithelial cells stimulated with estradiol and progesterone.

OBJECTIVE: Periodontal disease is a risk factor for preterm delivery, and elevated female hormone levels during pregnancy promote hormone-dependent periodontopathogenic bacterial growth and gingivitis. Although the saliva of pregnant women contains female hormones at elevated levels, their effects on the gingiva are poorly understood. Therefore, in this study, we investigated the effects of estradiol and progesterone stimulation on gingival epithelial cells via ingenuity pathway analysis. METHODS: Human gingival epithelial progenitors were cultured in a CnT-Prime medium; 17ß-estradiol (E2) and progesterone (P4) were used as the reagents. Cells treated with dimethyl sulfoxide alone were used as the control group. Cells in the control and experimental groups were incubated for 12 h. RNA was extracted from the cultured cells, RNA-Seq was performed, and pathway analysis was conducted. RESULTS: Differentially expressed genes were detected for 699 (over 2-fold increase) and 348 (decrease) genes in group E2 and for 1448 (increase) and 924 (decrease) genes in group P4 compared with those in the control group (FDR <0.05, n = 4). The z-scores of the pathways suggest that E2 and P4 increased the activity of the wound healing signaling pathway. The activation of this pathway was higher in the E2 and P4 groups than that in the control group. CONCLUSIONS: The results of this study suggest that estradiol and progesterone may affect gingival homeostasis and wound healing.

Effects of prolonged stimulation with heated tobacco products (Ploom TECH+ ) on gingival epithelial cells.

OBJECTIVE AND BACKGROUND: Heated tobacco products have recently become commercially available. These products, as well as combustible cigarettes, produce aerosols; the risk of various diseases associated with heated tobacco products may be the same or higher than that with combustible cigarettes. In this study, we examined the effect of Ploom TECH+ extract on gingival epithelial cells. METHODS: Tobacco leaves from Ploom TECH+ tobacco capsules and water were mixed and heated; the supernatant subsequently collected was the heated tobacco product (HTP; control: HTP not added). Normal human gingival epithelial progenitors were cultured alternately with or without HTP for a total of 1 month. Subsequently, RNA, DNA, and proteins were isolated from these samples and comprehensively analyzed using RNA sequencing (RNA-seq), reduced representation bisulfite sequencing (RRBS), and western blotting, respectively. RESULTS: RNA-seq revealed that 284 genes showed a twofold increase and 145 genes showed a twofold decrease in gene expression. A heat map showed genetic differences between the control and HTP groups. A principal component analysis plot showed a clear genetic distribution between the control and HTP. Gene Ontology (GO) analysis showed that genes related to seven GO terms, including cornification and keratinization, were induced by long-term HTP stimulation. By contrast, GO pathways with a significant decrease in component expression were not detected. RRBS revealed that CpG island methylation increased more than twofold in 158 genes and decreased to less than twofold in 171 genes. Methylation of these CpG islands was not correlated with changes in gene expression levels. HTP treatment increased S100A7 expression. CONCLUSION: Long-term HTP stimulation affected epithelial differentiation and keratinization of gingival epithelial cells. Thus, habitual use of Ploom TECH+ may be a risk factor for tobacco-related oral mucosal diseases.

Down-regulating Effect of a Standardized Extract of Cultured Lentinula edodes mycelia on Cortactin in Prostate Cancer Cells Is Dependent on Malignant Potential.

BACKGROUND/AIM: The incidence and mortality rates of prostate cancer have been increasing worldwide. Although prostate cancer cells grow slowly in the local original site, once the cancer cells spread to distant organs they grow rapidly and show very aggressive features. Cortactin is a protein that regulates the actin cytoskeleton and plays crucial roles in cancer metastasis. Up-regulated cortactin is correlated with the metastatic capacity of prostate cancer cells. AHCC®, a standardized extract of cultured Lentinula edodes mycelia, has been previously reported to have cortactin-down-regulating effects on human pancreatic cancer cells. In the present study, the effects of AHCC® treatment on cortactin levels in prostate cancer cells was evaluated. MATERIALS AND METHODS: LNCaP.FGC, DU145, and PC-3 are human prostate cancer cell lines. LNCaP.FGC is well differentiated, androgen-dependent, and poorly metastatic. DU145 is less differentiated, androgen-independent, and moderate metastatic. PC-3 is less differentiated, androgen-independent, and highly metastatic. The effects of AHCC® treatment on cortactin levels in prostate cancer cells was evaluated by western blot. RESULTS: In vitro AHCC® treatment decreased cortactin levels in LNCaP.FGC and DU145 cells but did not change those in PC-3 cells. CONCLUSION: AHCC® treatment down-regulated cortactin expression in poor and moderate metastatic LNCaP.FGC and DU145 cells but showed no effect on cortactin expression in the highly metastatic PC-3 cells. Further studies are required to elucidate the mechanism of the resistance to AHCC® treatment in highly metastatic PC-3 cells.

A Standardized Extract of Cultured Lentinula edodes mycelia Up-regulates COX-2 in Inflammation-related Malignant Progressive Fibrosarcoma Cell Clone QRsP-11.

BACKGROUND/AIM: Cyclooxygenase is an enzyme that transforms arachidonic acid to prostaglandins. Cyclooxygenase-2 (COX-2) is an isoform of cyclooxygenase. There exist many reports on the expression levels of COX-2 in cancer tissues, and prognosis of cancer patients has been reported to be related to COX-2 up-regulation. In the present study we assessed the suppressive effect of AHCC® on the expression of COX-2 in QRsP-11cells. MATERIALS AND METHODS: QR-32 is a clone which was derived from murine fibrosarcoma BMT-11 cells by treatment with quercetin. These clone cells regress spontaneously after injection into C57BL/6 mice. QRsP-11 is a clone derived from QR-32, showing very aggressive tumorigenicity. AHCC® is a standardized extract of cultured Lentinula edodes mycelia and has been reported to exert suppressive effects on various tumor-associated proteins including HSP27. The protein levels of COX-2 in QR-32 and QRsP-11 cells were compared by using western blotting. Furthermore, the expression levels of COX-2 were assessed in QRsP-11 cells after AHCC®-treatment. RESULTS: Western blot analysis showed a significant up-regulation of COX-2 in QRsP-11 cells compared to QR-32 cells. In vitro AHCC®-treatment increased COX-2 expression levels in QRsP-11 cells contrary to expectations. CONCLUSION: When using AHCC® in cancer treatment, it might be important to decrease COX-2 expression by means of non-steroidal anti-inflammatory drugs (NSAIDs), such as aspirin. Further studies are required to clarify the mechanism of up-regulation of COX-2 through AHCC®-treatment.

Systemic Administration of Lipopolysaccharide from Porphyromonas gingivalis Decreases Neprilysin Expression in the Mouse Hippocampus.

BACKGROUND/AIM: Alzheimer's disease is the most common type of neurodegenerative disorder in elderly individuals worldwide. Increasing evidence suggests that periodontal diseases are involved in the pathogenesis of Alzheimer's disease, and an association between periodontitis and amyloid-ß deposition in elderly individuals has been demonstrated. The aim of the present study was to examine the effects of systemic administration of Porphyromonas gingivalis-derived lipopolysaccharide (PG-LPS) on neprilysin expression in the hippocampus of adult and senescence-accelerated mice. MATERIALS AND METHODS: PG-LPS diluted in saline was intraperitoneally administered to male C57BL/6J and senescence-accelerated mouse prone 8 (SAMP8) mice at a dose of 5 mg/kg every 3 days for 3 months. Both C57BL/6J and SAMP8 mice administered saline without PG-LPS comprised the control group. The mRNA expression levels of neprilysin and interleukin (IL)-10 were evaluated using the quantitative reverse transcriptase-polymerase chain reaction. The protein levels of neprilysin were assessed using western blotting. Sections of the brain tissues were immunohistochemically stained. RESULTS: The serum IL-10 concentration significantly increased in both mouse strains after stimulation with PG-LPS. Neprilysin expression at both mRNA and protein levels was significantly lower in the SAMP8 PG-LPS group than those in the SAMP8 control group; however, they did not differ in PG-LPS-treated or non-treated C57BL/6J mice. Additionally, the immunofluorescence intensity of neprilysin in the CA3 region of the hippocampus in PG-LPS-treated SAMP8 mice was significantly lower than that in control SAMP8 mice. CONCLUSION: Porphyromonas gingivalis may reduce the expression of neprilysin in elderly individuals and thus increase amyloid-ß deposition.

The effect of Porphyromonas gingivalis on the gut microbiome of mice in relation to aging.

BACKGROUND AND OBJECTIVE: The translocation of oral bacteria, including Porphyromonas gingivalis, to the gut has been shown to alter gut microbiome. However, the effect of P. gingivalis on gut microbiome in relation to aging has not been demonstrated. We hypothesize that P. gingivalis has more detrimental effect on gut environment with increased age. The objective of this study is to investigate the effect of P. gingivalis on gut environment using aged mice. MATERIALS AND METHODS: C57BL/6J mice aged 4 weeks (young) or 76 weeks (old) were divided into four groups: control-young, control-old, P. gingivalis-administered young, and P. gingivalis-administered old. P. gingivalis was orally administered thrice weekly for 5 weeks. At 30 days after the last P. gingivalis administration, 16S rRNA sequencing was performed to study the gut microbiome. The mRNA and protein expression of intestinal junctional barrier molecules and the levels of the inflammatory cytokines IL-1ß and TNF-α in the serum were evaluated. RESULTS: Significant differences in the gut microbiomes between the groups, in terms of taxonomic abundance, bacterial diversity, and predicted metagenome function, were observed. A significant reduction in the alpha diversity and in the abundance of beneficial bacteria, such as Akkermansia and Clostridiaceae, in the P. gingivalis-administered old mice was observed. The mRNA and protein levels of Claudin-1 and Claudin-2 in the intestine were significantly elevated, while E-cadherin was significantly downregulated in the P. gingivalis-administered old mice, as were the serum levels of IL-1ß and TNF-α. CONCLUSION: The effect of P. gingivalis on the gut environment is more pronounced in old mice than in young mice.

AT-hook DNA-binding motif-containing protein one knockdown downregulates EWS-FLI1 transcriptional activity in Ewing's sarcoma cells.

Ewing's sarcoma is the second most common bone malignancy in children or young adults and is caused by an oncogenic transcription factor by a chromosomal translocation between the EWSR1 gene and the ETS transcription factor family. However, the transcriptional mechanism of EWS-ETS fusion proteins is still unclear. To identify the transcriptional complexes of EWS-ETS fusion transcription factors, we applied a proximal labeling system called BioID in Ewing's sarcoma cells. We identified AHDC1 as a proximal protein of EWS-ETS fusion proteins. AHDC1 knockdown showed a reduced cell growth and transcriptional activity of EWS-FLI1. AHDC1 knockdown also reduced BRD4 and BRG1 protein levels, both known as interacting proteins of EWS-FLI1. Our results suggest that AHDC1 supports cell growth through EWS-FLI1.

Induction of Periodontal Ligament-like Cells by Coculture of Dental Pulp Cells, Dedifferentiated Cells Generated from Epithelial Cell Rests of Malassez, and Umbilical Vein Endothelial Cells.

INTRODUCTION: Apart from the epithelial cell rests of Malassez (ERMs), dental pulp (DP) contains the same types of mesenchymal cells as the periodontal ligament (PDL). ERMs may affect the characteristics of the mesenchymal cells in the PDL. The aim of this study was to examine whether DP cells cultured with ERMs and human umbilical vein endothelial cells (HUVECs) could transform into PDL-like cells. METHODS: Progenitor-dedifferentiated into stem-like cells (Pro-DSLCs) were produced by the induction of ERMs with 5-Azacytidine and valproic acid. DP cells were cultured in mesenchymal stem cell medium for 1 week under the following conditions: DP cells alone (controls); PDL cells alone; coculture of DP cells and ERMs (DP + ERM) or Pro-DSLCs (DP + Pro-DSLC); and coculture of DP cells, HUVECs, and ERMs (DP + ERM + HUVEC) or Pro-DSLCs (DP + Pro-DSLC + HUVEC). Quantitative real-time reverse transcription polymerase chain reaction, quantitative methylation-specific polymerase chain reaction, and flow cytometry were performed. RESULTS: The expression levels of PDL-related markers Msx1, Msx2, Ncam1, Postn, and S100a4 and mesenchymal stem cell-positive markers Cd29, Cd90, and Cd105 were significantly higher in the PDL cells and DP + Pro-DSLC + HUVEC cultures than in the controls (P < .05). The DNA methylation levels of Msx1 and Cd29 in the PDL cells and the DP + Pro-DSLC + HUVEC culture were significantly lower than in the controls (P < .01). We found a significant increase in the number of cells stained with MSX1 (P < .05) and CD29 (P < .01) in the DP + Pro-DSLC + HUVEC culture than in the controls. CONCLUSIONS: Coculture of DP cells with Pro-DSLCs and HUVECs induced their transformation into PDL-like cells. This method may prove to be useful for periodontal regeneration via tissue engineering.

Gut flora alterations due to lipopolysaccharide derived from Porphyromonas gingivalis.

Gut dysbiosis induces 'leaky gut,' a condition associated with diabetes, NASH, and various auto-immune diseases. Porphyromonas gingivalis is a periodontopathic bacterium which causes periodontal tissue breakdown, and often enters the systemic blood flow. Oral administration of P. gingivalis induced gut dysbiosis in mice model, but no systemic administration of P. gingivalis has been reported thus far. In the present study, we investigated the effect of P. gingivalis-derived lipopolysaccharide (Pg-LPS) on the intestinal flora of our established mouse model. Eight-week-old C57BL/6J mice were intraperitoneally administered Pg-LPS. Three months later, DNA was extracted from stool, and RNA from the small and large intestines. After euthanizing the mice, pathological sections of the intestinal tract were prepared and stained with hematoxylin and eosin (H&E). Tumor necrosis factor alpha (TNF-α), interleukin (IL)-1ß, and IL-6 expression levels were evaluated using quantitative PCR. 16S rRNA gene PCR amplicon analysis data were acquired using NGS. Microbial diversity and composition were analyzed using Quantitative Insights into Microbial Ecology 2. Furthermore, alterations in microbial function were performed by PICRUSt2. No significant inflammatory changes were observed in the H&E. No significant differences in the mRNA levels of IL-1ß, IL-6, and TNF-α were observed between the groups. Pg-LPS administration decreased the abundance of Allobacterium in the gut. A predictive metagenomic analysis by PICRUSt2 and STAMP showed that 47 pathways increased and 17 pathways decreased after Pg-LPS administration. Systemic application of periodontal pathogens may cause changes in the intestinal flora which may affect the physiological functions of the intestinal tract.

Analysis of the cells isolated from epithelial cell rests of Malassez through single-cell limiting dilution.

The epithelial cell rests of Malassez (ERM) are essential in preventing ankylosis between the alveolar bone and the tooth (dentoalveolar ankylosis). Despite extensive research, the mechanism by which ERM cells suppress ankylosis remains uncertain; perhaps its varied population is to reason. Therefore, in this study, eighteen unique clones of ERM (CRUDE) were isolated using the single-cell limiting dilution and designated as ERM 1-18. qRT-PCR, ELISA, and western blot analyses revealed that ERM-2 and -3 had the highest and lowest amelogenin expression, respectively. Mineralization of human periodontal ligament fibroblasts (HPDLF) was reduced in vitro co-culture with CRUDE ERM, ERM-2, and -3 cells, but recovered when an anti-amelogenin antibody was introduced. Transplanted rat molars grown in ERM-2 cell supernatants produced substantially less bone than those cultured in other cell supernatants; inhibition was rescued when an anti-amelogenin antibody was added to the supernatants. Anti-Osterix antibody staining was used to confirm the development of new bones. In addition, next-generation sequencing (NGS) data were analysed to discover genes related to the distinct roles of CRUDE ERM, ERM-2, and ERM-3. According to this study, amelogenin produced by ERM cells helps to prevent dentoalveolar ankylosis and maintain periodontal ligament (PDL) space, depending on their clonal diversity.

An in vitro senescence model of gingival epithelial cell induced by hydrogen peroxide treatment.

Gingival tissue shows progressive changes with aging and an in vitro model of gingival tissue could be useful in understanding age-associated oral diseases. The present study aims to establish a hydrogen peroxide (H2O2) treatment model to induce aging in human gingival epithelial cells. In addition, fisetin, a flavonoid component studied for the anti-aging property is used to examine if it could reverse the induced senescence. Primary human gingival epithelial progenitor (HGEPp) cells were cultured and treated with different concentrations of H2O2. A cell vitality and morphology, senescence-associated beta-galactosidase (SA-ß-gal) staining, mRNA and protein expression analysis of known senescence markers p16, p21, and p53, and cell cycle assay were performed. The cells showed dose-dependent changes in vitality and morphology, SA-ß-gal staining, relative mRNA and protein expression, and cell cycle assay after H2O2 treatment. Based on these results, 400 µM H2O2 was considered as an optimal concentration to induce senescence. Treatment of senescence-induced cells with fisetin downregulated all the senescence markers used in this study. In conclusion, a senescence model of gingival epithelial cells induced by hydrogen peroxide treatment was established which could be employed to study age-related periodontal diseases.

Direct reprogramming of epithelial cell rests of malassez into mesenchymal-like cells by epigenetic agents.

The DNA demethylating agent, 5-Azacytidine (5Aza), and histone deacetylase inhibitor, valproic acid (Vpa), can improve the reprogramming efficiencies of pluripotent cells. This study aimed to examine the roles of 5Aza and Vpa in the dedifferentiation of epithelial cell rests of Malassez (ERM) into stem-like cells. Additionally, the ability of stem-like cells to differentiate into mesenchymal cells was evaluated. ERM was cultured in embryonic stem cell medium (ESCM) with 1 µM of 5Aza, or 2 mM of Vpa, or a combination of 5Aza and Vpa. The cells stimulated with both 5Aza and Vpa were named as progenitor-dedifferentiated into stem-like cells (Pro-DSLCs). The Pro-DSLCs cultured in ESCM alone for another week were named as DSLCs. The stem cell markers were significantly higher in the DSLCs than the controls (no additions). The mRNA and protein levels of the endothelial, mesenchymal stem, and osteogenic cell markers were significantly higher in the Pro-DSLCs and DSLCs than the controls. The combination of a demethylating agent and a deacetylated inhibitor induced the dedifferentiation of ERM into DSLCs. The Pro-DSLCs derived from ERM can be directly reprogrammed into mesenchymal-like cells without dedifferentiation into stem-like cells. Isolated ERM treated with epigenetic agents may be used for periodontal regeneration.

Aberrant expression of DUSP4 is a specific phenomenon in betel quid-related oral cancer.

Oral cancer due to betel quid chewing habit is very common in South Asian countries. We attempted to detect the presence of a novel gene in epithelial cells stimulated with arecoline, a main component of betel quid. Human gingival epithelial progenitors were cultured and treated with a 3-day alternating regimen with/without 50 µg/ml arecoline for 1 month. DNA microarray and methylation arrays were analyzed to identify the candidate genes. Immunohistochemical staining was performed in the tissue samples. Genome-wide analyses, quantitative reverse transcription PCR and quantitative methylation-specific PCR revealed DUSP4 as the most significant and promising gene. The methylation levels of DUSP4 were significantly higher in the betel quid-related oral squamous cell carcinoma (OSCC) than those in the non-related OSCC and controls (Mann-Whitney U test, p < 0.05). The number of DUSP4 immunopositive cells in betel quid-related OSCC was significantly higher than those from the non-chewing patients and the controls (p < 0.05). Hypermethylation of DUSP4 may be considered as a specific event in betel quid-related oral cancer.

Alteration of oral flora in betel quid chewers in Sri Lanka.

BACKGROUND: Betel quid chewing is known as a crucial risk factor for oral diseases such as periodontal diseases, oral cancer, and precancerous lesions in Southeast Asian countries. Although abnormal oral bacterial flora may be linked to betel quid related-oral diseases such as oral cancer, precancerous lesions, and periodontal diseases, little information is available on alterations of their oral flora thus far. To identify these alterations, we analyzed the oral flora in betel quid chewers (BQC) and non-chewers (NC) in Sri Lanka. METHODS: Samples obtained from buccal swabs of BQC and NC were analyzed with a next generation sequencer. Data were processed and analyzed using the QIIME software package. Mann-Whitney U test and Permutational multivariate analysis of variance were used for statistical analyses. P values < 0.05 were considered to be statistically significant. RESULTS: In BQC, the proportion of periodontal pathogens including Actinomyces, Tannerella, and Prevotella was higher than that in NC (P < 0.05), while the proportion of cariogenic pathogens including Streptococcus, Lautropia, and Actinobacillus was lower than that in NC (P < 0.05). A statistically significant difference in Shannon index and PD Whole tree was observed between BQC and NC (P < 0.05). PCoA analysis detected different clusters in BQC and NC (P < 0.05). CONCLUSION: The results suggested that betel quid chewing significantly altered oral flora. Adequate oral health care may help prevent BQC from developing bacterial pathogen-related oral diseases.

Involvement of RNase 7 in the malignant potential of oral squamous cell carcinoma cells.

RNase 7 is involved in the innate immunity of the oral epithelium. Variations in the expression levels of RNase 7 have been reported in cutaneous squamous cell carcinoma, but not in oral squamous cell carcinoma (OSCC). The present study investigated the expression levels of RNase 7 in OSCC and its role in the malignant potential of these cells. The localization of RNase 7 in OSCC tissue sections was determined via immunohistochemistry. Positive staining for RNase 7 was observed around the epithelial pearls and spinous cells of the OSCC tissues. Four different types of OSCC cell lines (OSC­19, BSC­OF, SAS, and HSC­2) and a normal keratinocyte (HaCaT) were used. The mRNA and protein expression levels of RNase 7 were significantly higher in the OSCC cells compared to the HaCaT cells. Based on our hypothesis that high levels of RNase 7 expression may be involved in the malignant potential of OSCC cells, the effect of RNase 7 knockdown on both proliferation and invasion were evaluated by transfecting the cells with siRNA. Cell numbers, cell invasion, and MMP 9 expression levels were significantly higher in the siRNA­BSC­OF, ­SAS, and ­HSC­2 cells compared to the BSC­OF, SAS, and HSC­2 cells. The extent of differentiation of the siRNA­OSCC cells was examined using the differentiation and undifferentiation markers involucrin (INV) and K14, respectively. The expression level of K14 was significantly higher in the siRNA­OSCC cells compared to the OSCC cells. Alternatively, HSC­2 and SAS cells demonstrated higher expression levels of INV compared to the siRNA­HSC­2 and ­SAS cells. These findings indicate that RNase 7 may contribute to the suppression of the malignant potential of OSCC.

Chronic stress-induced elevation of IL-1ß in the saliva and submandibular glands of mice.

Psychological stress is involved in the development of various oral diseases. Alterations in the levels of cytokines in the saliva of patients with stress-related oral diseases have been reported. However, the inconsistencies in the results of these studies might be attributed to differences in the local and systemic factors in the oral cavities of the patients. We examined the effect of chronic stress on three major inflammatory cytokines Interleukin (IL)-1ß, IL-6, and tumor necrosis factor (TNF)-α in the saliva and salivary glands of chronically stressed mice. Six-week-old C57BL/6 J mice were randomly divided into a control and a stress group. The mice in stress group were exposed to 4 h of stress daily for 10 days and subsequently saliva, as well as the submandibular glands, were collected from both groups. The expression levels of cytokines in the saliva were examined by enzyme-linked immunosorbent assay. The submandibular glands were subjected to histopathological and mRNA expression analyses. IL-1ß was significantly elevated in saliva of the chronic stressed mice. Furthermore, the mRNA expression levels of both IL-1ß and IL-6 were significantly elevated in the submandibular gland of chronic stressed mice. IL-1ß may be a potential salivary biomarker in response to chronic stress in mice.

Immunohistochemical Localization of RNase 7 in Normal and Inflamed Oral Epithelia and Salivary Glands.

RNase 7 is a skin-derived antimicrobial peptide expressed in various epithelial tissues. It is upregulated by stimulation with microbes and pro-inflammatory cytokines. Herein, we examined the expression levels of RNase 7 in tissues from normal and inflamed oral epithelia and salivary glands via immunohistochemistry. RNase 7 was expressed mainly in the surface layers of the parakeratinized and orthokeratinized oral epithelium. In addition, it was strongly and weakly expressed in oral lichen planus and radicular cysts, respectively. RNase 7 was constitutively expressed in salivary glands, particularly in the serous and duct cells. In the case of Sjogren's syndrome, RNase 7 was strongly expressed in serous, ductal, and mucous cells in areas with lymphocytic infiltration. The localization patterns of RNase 7 were similar to those of other epithelial antimicrobial peptides, including beta-defensins. Thus, epithelial antimicrobial peptides may act against microbial infections in a coordinated manner in oral epithelia and salivary glands.

Secretory Carcinoma of Minor Salivary Gland in Buccal Mucosa: A Case Report and Review of the Literature.

Secretory carcinoma (SC) of the salivary gland was recently added to the fourth edition of the World Health Organization classification of head and neck tumors. Some salivary tumors, including acinic cell carcinoma, have been reclassified as SC. Most of these tumors are located on the parotid gland with very few cases reported in the minor salivary glands of the buccal mucosa. Herein, we present a case of SC of buccal mucosa, which appeared clinically as a benign lesion in a 54-year-old Japanese female patient. Histopathologically, the tumor cells presented with an eosinophilic cytoplasm with microcytic structure along with eosinophilic secretory material and hemosiderin deposit. Immunohistochemical staining revealed strongly positive staining for S100, vimentin, and mammaglobin and negative staining for DOG-1. The tumor was finally diagnosed as secretory carcinoma of the buccal mucosa. We present a review of the medical literature of SC arising from minor salivary glands. We found only 15 cases of SC of buccal mucosa out of 63 cases of SC in the minor salivary glands. They showed good prognoses and only one case of SC in the buccal mucosa exhibited local recurrence and lymph node metastases.

Adenomatous ductal proliferation/hyperplasia in the parotid gland associated without any other pathological lesions; a report and survey of the literatures.

Adenomatous ductal proliferation/hyperplasia (ADP/H) is a rare hyperplastic condition of the salivary gland. It is mostly associated with other salivary gland pathologies such as tumors and inflammations, and is incidentally found in tissue sections during histopathological examinations of those diseases. Herein, we report a case of ADP/H in the parotid gland not associated with any other pathological lesions, and present a review of the literature on this condition. A 60-year-old Japanese female complained of swelling on the left side of parotid region. Clinical examination revealed a swelling on the lower lobe of the left parotid gland. The lesion was firm but non-tender and was not attached to adjacent structures. A clinical diagnosis of benign salivary gland tumor was reached, and surgical excision was performed under general anesthesia. Histopathological examination revealed an intact parotid gland capsule with isomorphic and basaloid cells within scanty cytoplasm. In addition, an admixture of hyperplasia and proliferation of the intercalated ducts, the presence of zymogen granules, the absence of solid nests, and a peripheral palisaded arrangement of the cells were observed. Based on these findings, a diagnosis of ADP/H was confirmed. ADP/H is a non-tumorous lesion; therefore, tumor involvement should be ruled out before the diagnosis is reached.