Tianfu Wu

Correlation of ALDH1, CD44, OCT4 and SOX2 in tongue squamous cell carcinoma and their association with disease progression and prognosis.

BACKGROUND Recently, studies indicated that cancer stem cell plays a key role in cancer development and progression. However, the role of cancer stem cell has not been well elucidated in tongue squamous cell carcinoma (TSCC). The objective of this study was to investigate the relationships between the expressions of stem cell markers and the prognosis of TSCC. MATERIALS AND METHODS Immunohistochemistry was employed to analyse the protein expression levels of ALDH1, CD44, OCT4 and SOX2 in 66 TSCC tissue samples. The results were then evaluated semiquantitatively and compared with other clinicopathological variables. RESULTS Immunohistochemistry revealed that the ALDH1, CD44, OCT4 and SOX2 proteins were overexpressed in the 66 TSCC specimens used in this study. Spearmans correlation analysis showed that the expressions of ALDH1 and CD44 were significantly correlated with SOX2 except other proteins (P < 0.05) and that OCT4 and SOX2 were significantly related (P < 0.01). Kaplan-Meier analysis revealed that T category, node metastasis, TNM stage, differentiation and distant metastasis were associated with poor patient survival (P < 0.05). Multivariate Cox regression analysis demonstrated that SOX2, recurrence and distant metastasis were independent prognostic factors of overall survival in patients with TSCC. CONCLUSION Taken together, these data suggest that the stem cell markers ALDH1, CD44, OCT4 and SOX2 are closely related in TSCC, and the expression of SOX2 can be used as a prognostic indicator of TSCC.

Increased Expression of Lin28B Associates with Poor Prognosis in Patients with Oral Squamous Cell Carcinoma

Recent studies showed that incomplete cell reprogramming can transform cells into tumour-like cells. Lin28A is associated with fibroblast and sarcoma cell reprogramming, whereas its homologue Lin28B is associated with hematopoietic cell reprogramming. This study aimed to investigate the expression and prognostic difference between Lin28A and Lin28B in oral squamous cell carcinoma (OSCC). Expression level was assessed by immunohistochemistry and staining location was confirmed by immunofluorescence. Prognostic values were analysed and compared by the Kaplan–Meier analysis and uni and multivariate Cox regression models. Besides, in vitro cell assays and in vivo nude mice xenograft were used to demonstrate the influence of increased Lin28B expression in OSCC. Lin28A and Lin28B expression increased in OSCC, and co-expression of Lin28A and Lin28B showed no significant association with patient prognosis. Kaplan–Meier analysis showed that patients with high Lin28B but not Lin28A expression had lower overall survival (OS) rates than those with low Lin28B expression. Further Univariate analysis showed that patients with increased Lin28B expression had shorter disease-free survival (DFS) and shorter OS, while multivariate analysis showed Lin28B overexpression with TNM stage predicted poor prognosis in patients with OSCC. Besides, stable expressing Lin28B in oral cancer cells promoted cell migration, invasion, colony formation, in vivo proliferation and increased the expression of cancer suppressor miRNA let-7 targeted genes IL-6, HMGA2, the EMT markers Snail and Twist, the angiogenesis inducer VEGF, and the apoptosis inhibitor Survivin. These combined results indicate that Lin28B is a novel marker for predicting prognosis in patients with OSCC and may be a therapeutic target.

Dihydromyricetin promotes autophagy and apoptosis through ROS-STAT3 signaling in head and neck squamous cell carcinoma

Chemotherapy is an effective weapon in the battle against cancer, but numerous cancer patients are either not sensitive to chemotherapy or develop drug resistance to current chemotherapy regimens. Therefore, an effective chemotherapy mechanism that enhances tumor sensitivity to chemotherapeutics is urgently needed. The aim of the present study was to determine the antitumor activity of dihydromyricetin (DHM) on head and neck squamous cell carcinoma (HNSCC) and its underlying mechanisms. We demonstrated that DHM can markedly induce apoptotic cell death and autophagy in HNSCC cells. Meanwhile, increased autophagy inhibited apoptosis. Pharmacological or genetic inhibition of autophagy further sensitized the HNSCC cells to DHM-induced apoptosis. Mechanistic analysis showed that the antitumor of DHM may be due to the activation phosphorylation of signal transducer and activator of transcription 3 (p-STAT3), which contributed to autophagy. Importantly, DHM triggered reactive oxygen species (ROS) generation in the HNSCC cells and the levels of ROS decreased with N-acetyl-cysteine (NAC), a ROS scavenger. Moreover, NAC abrogated the effects of DHM on STAT3-dependent autophagy. Overall, the following critical issues were observed: first, DHM increased the p-STAT3-dependent autophagy by generating ROS-signaling pathways in head and neck squamous cell carcinoma. Second, inhibiting autophagy could enhance DHM-induced apoptosis in head and neck squamous cell carcinoma.

Morphogenesis of rete ridges in human oral mucosa: a pioneering morphological and immunohistochemical study.

Objective: One of the major impediments in tissue-engineered oral mucosa (TEOM) is the lack of rete ridge (RR) structures that can weaken the connection between the epidermis and dermis. This study aimed to investigate the native morphology of RRs as well as the expression of extracellular signal-regulated kinase 1/2 (ERK1/2), Ki67, and keratin-19, which are related to cell mechanotransduction, proliferation, and stemness in the oral epidermis, respectively. Methods: RR characteristics, including type, density, length, and width, were analyzed in the masticatory mucosa (Mm) and lining mucosa (Lm) sites of 52 specimens. The expression of ERK1/2, Ki67, and keratin-19 was assessed by immunohistochemistry. ERK1/2 activation by masticatory stimuli was confirmed in vitro by loading pressure onto cultured keratinocytes isolated from the specimens. Results: Three types of RR were found. The RRs in the Mm and Lm differed. The length and percentage of ERK1/2-positive (%ERK1/2+) basal layer cells had a negative correlation (p = 0.004), whereas the length and %Ki67+ basal layer cells had a positive correlation (p = 0.013). The %ERK1/2+ basal layer cells and %keratin-19+ basal layer cells had a negative relationship (p = 0.011). ERK1/2 activation in the oral epithelium was induced by pressure and propagated in cultured keratinocytes. Conclusion: RRs are longer in the Mm, which may result from the topical basal cell proliferation and migration induced by masticatory pressure via ERK1/2 activation. Our findings preliminarily interpret RR histomorphology as influenced by oral masticatory pressure. Results may benefit future studies on RR development and reconstruction in TEOM models to enhance the epidermis-dermis connection.

Histological features of oral epithelium in seven animal species: As a reference for selecting animal models

Several animals have been used as models for basic and clinical research on oral mucosa. Few studies have focused on the selection of an appropriate animal model. This study aimed to provide histological references for selecting a potential model. Histological features were assessed by exploring 6 morphological characteristics and 2 immunohistochemical markers. The morphological characteristics included keratinization, basal membrane appearance, epithelial thickness, rete ridge length, adjacent rete ridge distance, and regional variation; the immunohistochemical markers included Ki67 (a proliferative marker) and Cytokeratin 19 (CK19; a stemness marker). The histological similarity of each species compared to humans was calculated according to the designated scoring criteria. The results showed that the buccal mucosae from dog and pig were non-keratinized, with similar rete ridge length and distance, compared to that of humans. The dog, rat, and cavy mucosae had analogous gross appearances in the basal membrane. The dog oral mucosae shared similar epithelial thickness with human oral mucosae. Compared to the human mucosa, the dog, pig, rat, and rabbit mucosae exhibited corresponding regional variations. The Ki67-positive cells in human and canine mucosae were predominantly localized in the suprabasal layers, whereas most of the proliferative cells were in the basal layer in other species. CK19 immunoreactivities were detected only in human and canine mucosae. The canine mucosae gained the highest point value (14), whereas the scores for the pig, rat, rabbit, cavy, sheep, and buffalo mucosae were 8, 6, 5, 5, 5, and 2, respectively. The histological variations in the oral epithelium of diverse animal species are considerable; the mucosae from dogs are most similar to human mucosae, implicating its histological basis as an animal model.

Physical forces make rete ridges in oral mucosa.

Rete ridge has important functions in the epidermis, but the current tissue engineered oral mucosa or skin equivalents are generally lack of this structure. To regenerate a rete ridge structure in the oral mucosa equivalents, we firstly attempted to make clear how rete ridge is formed in the oral mucosa and the preliminary study disclosed the mechanical stress evoked the morphogenesis of rete ridge. In this paper, we make a hypothesis that the morphogenesis of rete ridge is elicited by the physical forces and proceed with the internal pushing forces derived from the keratinocyte division, among these process, the activated ERK and PC cascades, accompanied with the MMPs liberated growth factors are working together to induce the keratinocyte proliferation, these cell divisions produced internal forces, which not only push the keratinocyte stem cells and progenitor cells to migrate in the contrary directions but also in turn to activate the ERK and PC cascades, meanwhile, the activated MMPs degrade the ECM of lamina propria, under these internal pushing forces and the remodeling of lamina propria, rete ridge is gradually formed. This hypothesis gives us the possibility to regenerate the rete ridge structure in the tissue engineered oral mucosa or skin equivalents through simulating the morphogenesis of rete ridge.

CD44 + cancer cell-induced metastasis: A feasible neck metastasis model

ABSTRACT Neck metastasis of oral squamous cell carcinoma (OSCC) indicates a poor prognosis. Few neck metastasis models are currently available for drug trials and clinical research on OSCC. This study constructed a feasible animal model of neck metastasis by using CD44 + stem cell‐like cancer cells. Real‐time PCR was used to determine the expression levels of several reported cancer stem cell (CSC) markers, including CD44, CD133, ALDH1 and OCT4, in three OSCC cell lines. Magnetic sorting and DiO/DiD labelling were used to isolate subpopulations of cells and monitor cancer cell migration. Sorted and labelled CSC‐like cells were injected into the tongue of nude mice. Tumour and metastatic lymph nodes were histologically examined through immunostaining and tracer staining. High rate of metastasis was observed in neck lymph nodes in CD44 + group. This phenomenon was confirmed in clinical OSCC patients, and CD44 expression levels were higher in tumours with lymph node metastasis than in carcinomas in situ. Therefore, we have successfully constructed a neck metastasis model by using CD44 + CSCs. This model can form tumour and show metastases within a short period of time compared with other models; additionally, this model may be used in short‐term pharmacological experiments involving animals and in basic clinical studies. Graphical abstract Figure. No Caption available.

Evaluation of the clinical photographs in the Journal of Oral and Maxillofacial Surgery: from readers' perspectives.

PURPOSE This study was designed to evaluate clinical photographs published in the Journal of Oral and Maxillofacial Surgery (JOMS) and understand the current status of oral and maxillofacial surgery. MATERIALS AND METHODS A total of 1,317 photographs from the JOMS Volume 69 were assessed. These photographs were scored from 1 to 10 for the following parameters: sharpness; depth of field; exposure; composition; color or grayscale; background; position; distortion; label consistency; and white balance. Then, the distributions of scores were analyzed. Each score was compared with the average score. The effects of different subjects; emergency or nonemergency situations; and intraoperative, preoperative, or postoperative conditions on the quality of photographs were analyzed by conducting a nonparametric Kruskal-Wallis test. RESULTS The total score of each photograph showed a left-skewed distribution, varying from 3 to 10, with an average score of 6.82. Four parameters, including sharpness, depth of field, exposure, and white balance, scored less than the average score. Photographs with an intraoral subject yielded the lowest score, with a significant difference (P < .05). The score of photographs taken during a nonemergency situation was significantly higher than that during an emergency situation (6.84 vs 6.03; P < .001). Photographs of an intraoperative condition yielded a score significantly lower than those of pre- and postoperative conditions (6.53 vs 7.11 and 6.75, respectively; P < .001). Approximately 45.5% of photographs (148 of 325) displayed uncovered eyes and 57.1% of specimens (40 of 70) did not appear with a plotting scale. CONCLUSIONS Sharpness, depth of field, exposure, and white balance should be considered to a greater extent than the other parameters when oral and maxillofacial photographs are taken, particularly for intraoral conditions, emergency situations, and intraoperative conditions. Enhanced parameters and protection of a patients identity may significantly improve the average level of photographic quality.

Expression and associations of TRAF1, BMI-1, ALDH1, and Lin28B in oral squamous cell carcinoma.

Tumor necrosis factor receptor–associated factor 1, an adaptor protein of tumor necrosis factor 2, is involved in classical nuclear factor (NF)-κB activation and lymphocyte recruitment. However, less is known about the expression and association of tumor necrosis factor receptor–associated factor 1 with cancer stem cell markers in oral squamous cell carcinoma. This study aimed to investigate the expression of tumor necrosis factor receptor–associated factor 1 and stem cell characteristic markers (lin28 homolog B, B cell-specific Moloney murine leukemia virus integration site 1, and aldehyde dehydrogenase 1) in oral squamous cell carcinoma and analyze their relations. Paraffin-embedded tissues of 78 oral squamous cell carcinomas, 39 normal oral mucosa, and 12 oral dysplasia tissues were employed in tissue microarrays, and the expression of tumor necrosis factor receptor–associated factor 1, B cell-specific Moloney murine leukemia virus integration site 1, aldehyde dehydrogenase 1, and lin28 homolog B was measured by immunohistostaining and digital pathological analysis. The expression of tumor necrosis factor receptor–associated factor 1 was higher in the oral squamous cell carcinoma group as compared with the expression in the oral mucosa (p < 0.01) and oral dysplasia (p < 0.001) groups. In addition, the expression of tumor necrosis factor receptor–associated factor 1 was associated with those of B cell-specific Moloney murine leukemia virus integration site 1, aldehyde dehydrogenase 1, and lin28 homolog B (p = 0.032, r2 = 0.109; p < 0.0001, r2 = 0.64; and p < 0.001, r2 = 0.16) in oral squamous cell carcinoma. The patient survival rate was lower in the highly expressed tumor necrosis factor receptor–associated factor 1 group, although the difference was not significant. The clustering analysis showed that tumor necrosis factor receptor–associated factor 1 was most related to aldehyde dehydrogenase 1. These findings suggest that tumor necrosis factor receptor–associated factor 1 has potential direct/indirect regulations with the cancer stem cell markers in oral squamous cell carcinoma, which may help in further analysis of the cancer stem cell characteristics.

Could wisdom tooth provide tooth germs for tooth regeneration

Introduction Regenerating a tooth completely in human oral cavity is not achieved by current studies yet. Here, we have conceived a man-induced method to construct a teeth germ which might be used to regenerate a tooth in vivo. This idea was generated by traits of the development of the compound odontoma, a benign tumour of tooth malformation. This is a kind of developmental tooth malformation, characterised by several small teeth inside the entity. Those scattered denticles/daughter teeth germs, formed in the early stage of odontoma morphogenesis, show similar layers as in a normal tooth, and could grow into tooth-like shapes. In consideration with recent report that mouse tooth germ constructed in vitro could develop into a fully functioned tooth in adult mouse jaws. We hope this hypothesis helps generate tooth germs for in vivo implantation. Hypothesis Tooth germ of wisdom tooth might be separated into small daughter germs by bone trabecular using tissue-engineering method, to provide more than one tooth germ for tooth regeneration. Evaluation of hypothesis By reconstruction existing dental tissues during tooth organgenesis in the jaw, this hypothesis shows advantage than generating tooth from single stem cell or artificial tooth graft. Conclusion Proving this hypothesis not only facilitates the acquirement of numerous homologous and immunological rejection-free teeth germs to treat tooth loss and deficit, but also helps afford an alternative lesson that merits attention in other human organ regeneration fields.