Recurrence and cancerization of ameloblastoma: multivariate analysis of 87 recurrent craniofacial ameloblastoma to assess risk factors associated with early recurrence and secondary ameloblastic carcinoma

Objective: The recurrence and progression of ameloblastoma are unpredictable. Therefore, we examined the influence of clinical factors on recurrence time and analyzed the clinical factors associated with early recurrence and cancerization. We then developed a staging system to predict early recurrence and cancerization. Methods: All of the primary craniofacial ameloblastoma patients treated in Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine were recorded. There were 87 recurrent cases used to create a staging system and tested in a Cox regression analysis for risk factors associated with early recurrence or cancerization following surgery. Results: There were 890 craniofacial ameloblastoma patients, and 72 cases had recurrence. There were also 15 cases with cancerous recurrence. The overall recurrence rate was 9.78%, and the cancer rate was 1.69%. The primary cases were classified into the following 3 stages based on clinicopathological features: stage I, the maximum tumor diameter <= 6 cm; stage II, the maximum diameter of tumor >6 cm or tumor invasion to the maxilla sinus/orbital floor/soft tissue; and stage III, tumor invasion of the skull base or metastasis into regional lymph nodes. When the method of surgery was controlled by partial correlation, the staging had significance with recurrence time (P=0.004). The Cox analysis showed the tumor stage was correlated with recurrence time (P=0.027) and cancerization time (P=0.002). However, the surgical method did not influence the recurrence time when adjusted for cofounding variables. Conclusions: Tumor larger than 6 cm and invasion to soft tissues or adjacent anatomical structures are associated with early recurrence. This staging system can be used to predict the risk factors of early recurrence and cancerization in ameloblastoma patients.

Globoside accelerates the differentiation of dental epithelial cells into ameloblasts

Tooth crown morphogenesis is tightly regulated by the proliferation and differentiation of dental epithelial cells. Globoside （Gb4）, a globo-series glycosphingolipid, is highly expressed during embryogenesis as well as organogenesis, including tooth development. We previously reported that Gb4 is dominantly expressed in the neutral lipid fraction of dental epithelial cells. However, because its functional role in tooth development remains unknown, we investigated the involvement of Gb4 in dental epithelial cell differentiation. The expression of Gb4 was detected in ameloblasts of postnatal mouse molars and incisors. A cell culture analysis using HAT-7 cells, a rat-derived dental epithelial cell line, revealed that Gb4 did not promote dental epithelial cell proliferation. Interestingly, exogenous administration of Gb4 enhanced the gene expression of enamel extracellular matrix proteins such as ameloblastin, amelogenin, and enamelin in dental epithelial cells as well as in developing tooth germs. Gb4 also induced the expression of TrkB, one of the key receptors required for ameloblast induction in dental epithelial cells. In contrast, Gb4 downregulated the expression of p75, a receptor for neurotrophins （including neurotrophin-4） and a marker of undifferentiated dental epithelial cells. In addition, we found that exogenous administration of Gb4 to dental epithelial cells stimulated the extracellular signal-regulated kinase and p38 mitogen-activated protein kinase signalling pathways. Furthermore, Gb4 induced the expression of epiprofin and Runx2, the positive regulators for ameloblastin gene transcription. Thus, our results suggest that Gb4 contributes to promoting the differentiation of dental epithelial cells into ameloblasts.

The similarity between human embryonic stem cell-derived epithelial cells and ameloblast-lineage cells

This study aimed to compare epithelial cells derived from human embryonic stem cells(hESCs) to human ameloblast-lineage cells (ALCs),as a way to determine their potential use as a cell source for ameloblast regeneration.Induced by various concentrations of bone morphogenetic protein 4(BMP4),retinoic acid(RA) and lithium chloride(LiCI) for 7 days,hESCs adopted cobble-stone epithelial phenotype(hESC-derived epithelial cells(ES-ECs)) and expressed cytokeratin 14.Compared with ALCs and oral epithelial cells(OE), ES-ECs expressed amelogenesis-associated genes similar to ALCs.ES-ECs were compared with human fetal skin epithelium,human fetal oral buccal mucosal epithelial cells and human ALCs for their expression pattern of cytokeratins as well.ALCs had relatively high expression levels of cytokeratin 76,which was also found to be upregulated in ES-ECs.Based on the present study,with the similarity of gene expression with ALCs,ES-ECs are a promising potential cell source for regeneration,which are not available in erupted human teeth for regeneration of enamel.

Ameloblastic carcinoma: Report of a rare case

Ameloblastic carcinoma is a rare odontogenic tumor exhibiting histological evidence of malignancy in the primary or recurrent tumor. It is characterized by rapid, painful expansion of the jaw, unlike conventional ameloblastomas. The tumor most frequently involves the mandible. The expanding lesion causes perforation of the buccal and lingual plates of the jaw and invades the surrounding soft tissue. Rapidly growing large tumor mass may cause tooth mobility. A mandibular tumor involving the mental nerve leads to paresthesia of the nerve. A maxillary tumor can produce a fistula in the palate and paresthesia of the infraorbital nerve. Most ameloblastic carcinomas are presumed to have arisen de novo with a few cases of malignant transformation of ameloblastomas. Although rare, these lesions have been known to metastasize, mostly to the regional lymph nodes or lungs. A case of ameloblastic carcinoma in a 60-year-old man is reported here and its clinical, radiological and histological features are discussed.

An Aggressive Ameloblastic Fibroma in Maxilla of a 5-Year-Old Child—Reconstruction of the Defect with Buccal Flap Advancement—A Conservative Approach

Ameloblastic fibroma (AF) is a rare tumour of mixed odontogenic origin that can occur either in mandible or maxilla but is most frequently found in the posterior region of mandible. Age of occurrence is generally between first and second decades of life. It is often mistaken for a den tigerous cyst due to presence of an impacted tooth. The diagnosis of AF usually occurs accidentally by routine radiographic examination for an impacted tooth. Histologically it consists of odontogenic ectomesenchyme resembling the dental papilla, epithelium resembling dental lamina and enamel organ without dental hard tissues. There is controversy in the literature as to whether the treatment should be conservative or a radical resection should be done. A conservative treatment strategy, such as enucleation and curettage, is usually sufficient. We describe a case of massive ameloblastic fibroma in a 5-year-old child with an unusual position in maxillary posterior region and without any impacted tooth. Surgical resection of the tumor through Weber Ferguson approach was done under GA with 2 years of follow-up without any recurrence.

高氟干预成釉细胞钙稳态差异表达基因的筛选及分析

背景:氟牙症是长期摄入大量氟所导致的牙釉质发育障碍,病因复杂,其发病机制有待深入研究。目的:通过转录组测序技术筛选高氟干预成釉细胞与钙稳态相关的差异表达基因,并进一步探索氟斑牙形成的分子机制。方法:分别用浓度为0,0.4,0.8,1.6,3.2,6.4 mmol/L的NaF处理成釉细胞LS824,48,72 h,检测细胞形态、细胞活性与细胞内钙离子浓度。分别用浓度为0,1.6,3.2 mmol/L的NaF处理成釉细胞LS824 h,通过转录组测序筛选差异表达基因,并对差异表达基因进行验证。结果与结论:①处理24 h后,NaF浓度0,0.4,0.8 mmol/L组细胞生长状态良好,细胞的数量增多,细胞轮廓清晰;当NaF浓度≥1.6 mmol/L,随着NaF浓度的增加,细胞体积逐渐皱缩变小、细胞数量减少。处理48,72 h后,NaF浓度0,0.4 mmol/L组细胞数量增加,0.8,1.6,3.2 mmol/L组细胞数量逐渐减少,细胞形态变圆、变小,6.4 mmol/L组细胞皱缩变圆悬浮于培养基中,几乎无细胞贴壁。当NaF浓度相同时,处理24 h后LS8细胞的生长状态最佳。CCK-8检测结果显示,当NaF浓度相同时,随着处理时间的延长,细胞活性减弱;当处理时间相同时,随着NaF浓度的增加,细胞活性减弱。处理24 h后,随着NaF浓度的增加,细胞内钙离子浓度增加。②转录组测序分析发现参与调控细胞钙稳态的基因:Hsp90b1、Canx、Calr、Hspa5的表达显著上调(P<0.05),Cacna1a的表达显著下调(P<0.05),该结果得到了RT-qPCR检测的验证。③结果显示,NaF对LS8细胞增殖的抑制作用可能与细胞内Ca2+浓度异常增加有关,其机制可能由蛋白质加工合成通路Hsp90b1、Canx、Calr、Hspa5表达上调和钙信号通路Cacna1a表达下调所导致。

BRAF V600E在成釉细胞瘤、成釉细胞癌和囊肿中的表达

目的:探讨BRAF V600E表达是否与成釉细胞瘤复发、恶变有关。方法:运用免疫组织化学和实时荧光定量PCR(qPCR)检测成釉细胞瘤、成釉细胞癌、囊肿中BRAF V600E的蛋白和基因表达水平。采用SPSS 26.0软件包对数据进行统计学分析。结果:BRAF V600E在原发性成釉细胞瘤和复发性成釉细胞瘤中的表达无显著差异,在囊肿和成釉细胞癌中的表达显著减少。免疫组织化学和RT-qPCR检测的阳性率一致。结论:成釉细胞瘤中BRAF V600E的蛋白表达与年龄、性别、部位、大小、组织学类型以及是否复发无关,BRAF V600E的表达对鉴别成釉细胞瘤、囊肿、成釉细胞癌有一定指导意义。使用免疫组织化学方法或许能初步检测成釉细胞瘤中是否存在BRAF突变。

Central Granular Cell Odontogenic Tumor: A Literature Review of Cases Reported in the Last 71 Years with a New Case Report

Central granular cell odontogenic tumors(CGCOTs)are rare,benign,slowly growing odontogenic neoplasms.Due to their uncertain histogenesis,CGCOTs are still not included as a distinct entity in the WHO classification(2017)of odontogenic tumors.We report a case of CGCOT involving the right side of maxillary anterior region of a 39-year-old white female.Immunohistochemical staining showed that granular cells positively expressed CD68 and vimentin,and negatively expressed S-100 protein.Meanwhile,we searched Pub Med,Google Scholar,and Scopus databases to summary the clinico-pathological features of 51 reported cases of CGCOT.The results showed that the granular cells of 28.6%cases were immunopositive for vimentin and CD68,and odontogenic epithelial cells were positive immunoreactivity for cytokeratin.These findings reinforced the mesenchymal origin of granular cells and the odontogenic nature of epithelium islands.

Sirt1调控上皮细胞衰老的研究进展

在牙釉质发育过程中,成釉细胞过早衰老和凋亡是遗传性牙釉质发育不全的重要原因。沉默信息调节因子2相关酶1(silent matingtype information regulator 2 homolog 1,Sirt1)是一种依赖烟酰胺腺苷二核苷酸(nico⁃tinamide adenine dinucleotide,NAD+)的脱乙酰酶,已被广泛报道参与调节细胞衰老。本文就Sirt1调控上皮细胞衰老研究进展作一综述,从Sirt1的结构特点入手,阐述Sirt1与衰老的关系。研究表明,当上皮细胞受到外界刺激时,Sirt1通过多种途径影响上皮细胞的衰老:Sirt1参与调节线粒体功能和代谢稳态,线粒体功能障碍会影响细胞衰老表型;端粒长度与衰老呈负相关,Sirt1调节端粒延伸所需的端粒逆转录酶的表达,从而正向调节端粒的稳态;DNA受损后会经历损伤修复,未修复的DNA损伤会引起细胞衰老,Sirt1/p53通路可通过减轻DNA损伤抑制上皮细胞衰老;衰老细胞是慢性炎症的来源,慢性炎症也可以多种方式促成衰老,Sirt1通过缓解炎症症状抑制上皮细胞衰老。未来可重点关注Sirt1对成釉细胞衰老的影响,探究其对成釉细胞的具体作用机制,以期在釉质发育不全病因及治疗中找到突破。

31例成釉细胞癌临床特点分析

目的探讨成釉细胞癌(AC)的临床特点、治疗及预后。方法回顾性分析2012年7月至2022年7月郑州大学第一附属医院收治的31例AC患者的临床资料,并采用Kaplan-Meier法进行生存分析。结果31例患者中,男19例,女12例,男女比例约为1.6∶1,发病年龄23~83岁,中位年龄58岁。下颌骨多见,肿胀与疼痛是常见的症状。患者均接受手术治疗,28例接受肿瘤扩大切除术,3例接受姑息性切除术。所有患者均获随访,随访时间1.0~116.0个月,平均(55.52±31.14)个月。8例局部复发,5例远处转移,11例死亡,生存分析显示本组病例5 a生存率为66.86%。结论AC临床表现不典型,明确诊断需依靠病理,治疗以手术为主,术后复发率高,预后一般。

1例猫牙龈棘皮瘤的诊治

牙龈棘皮瘤是一种比较常见的牙源性上皮良性肿瘤,会引起广泛的局部破坏,引起患畜进食困难,且有复发的可能。详细介绍了1例猫棘皮瘤的诊断与治疗方案,临床检查、实验室检查及病理检查确诊为良性肿瘤,经手术和药物治疗后康复出院,为猫牙龈棘皮瘤的诊断及手术治疗提供参考。

TGF-β1调控成釉细胞ODAM基因表达的研究

目的:探讨TGF-β1对ODAM基因表达的作用。方法:通过实时定量RT-PCR法观察TGF-β1对成釉细胞ODAM基因表达的影响;利用c-jun小RNA干扰(siRNA)技术,阻断转录因子c-jun基因表达,观察c-jun基因沉默对TGF-β1诱导ODAM基因表达的影响;利用双荧光素酶基因报告系统研究成釉细胞中TGF-β1对ODAM启动子转录活性的调控作用。结果:TGF-β1刺激成釉细胞后,ODAM基因表达显著增强;利用小RNA干扰技术使c-jun基因沉默,实时定量RT-PCR法研究显示,TGF-β1调控ODAM基因表达的作用减弱。将pGL3-ODAM转染成釉细胞后,用TGF-β1刺激成釉细胞一定时间,ODAM启动子的转录活性增强。c-jun基因沉默抑制了TGF-β1对ODAM启动子的激活作用。结论:在釉质发育过程中,TGF-β1通过转录因子c-jun调控成釉细胞ODAM基因表达。

Clinical management of primary odontogenic sarcoma in the mandible:a case report after WHO nomination

Ameloblastic fibro-odontosarcoma(AFOS)now designated as odontogenic sarcoma is an extremely rare odontogenic tumor,which histologically presents as a biphasic neoplasm with a malignant mesenchymal component plus ameloblastic epithelium.Here we report a 27-year-old Chinese female with the complaint of a painful swelling for half a month in the right mandible.A segmental mandibulectomy,with an immediate mandibular reconstruction using a free vascularized osteocutaneous fibular flap was performed using surgical guide models.Histological analysis revealed a primary odontogenic sarcoma.The postoperative period was uneventful,and no clinical indication of recurrence or metastasis was observed during the 3-year follow-up.No adjuvant therapy was proposed.This is the first odontogenic sarcoma case reported in China after the new World Health Organization classification of odontogenic lesions.

Mixed odontogenic tumors:A review of the clinicopathological and molecular features and changes in the WHO classification

BACKGROUND Ameloblastic fibromas and ameloblastic fibrosarcomas are rare odontogenic tumors,and controversy exists in the classification of cases presenting hard-tissue production:Ameloblastic fibrodentinoma(AFD)and ameloblastic fibro-odontoma(AFO).These cases are currently considered“developing odontomas”(hamartomatous lesions).AIM To analyze the clinicopathologic features of these lesions and discuss the changes in the 2017 World Health Organization classification.METHODS An electronic literature search was performed in the PubMed/MEDLINE database.An electronic search of the English language literature was performed and last updated in September 2020 in the PubMed/MEDLINE database using the following terms:“ameloblastic fibroma”,“ameloblastic fibrodentinoma”,“ameloblastic fibro-odontoma”,“ameloblastic sarcoma”,“ameloblastic fibrosarcoma”,“ameloblastic fibrodentinosarcoma”,“ameloblastic fibroodontosarcoma”and“odontogenic carcinosarcoma”.The inclusion criteria were odontogenic tumor series,case reports and systematic reviews that provided sufficient clinical,radiological and microscopic documentation to confirm the diagnosis.RESULTS The database search strategy resulted in 947 papers.Articles focusing on other topics,articles that were not in English,duplicate articles,and articles without fulfilling the inclusion criteria were excluded.Finally,96 publications were included in this review to describe and discuss the main features of the searched entities.Several aspects of AFO and AFD,such as biological behavior,age of occurrence,amount of hard tissue,and potential for malignant transformation into odontogenic sarcomas,support the neoplastic nature in most of the reported cases.Considering the clinical,radiographic,histopathological and molecular characteristics of odontogenic lesions with hard tissue production,we suggest that these types of lesions should continue to be recognized as odontogenic tumors by maintaining the classically used terms.CONCLUSION This recommendation will be relevant for future clinical,microscopic,and molecular studies to better understand the biology of these interesting odontogenic tumors.

成釉细胞纤维瘤与成釉细胞纤维肉瘤

目的 :观察成釉细胞纤维瘤 (ameloblasticfibroma ,AF)及成釉细胞纤维肉瘤 (ameloblasticfibrosarcoma ,AFS)的间质成份 ,探讨其与临床生物学行为的关系。方法 :14例肿物 (AF 11例 ,AFS 3例 )切片经HE染色 ,光镜下观察 ,5例新鲜标本 (AF 3例 ,AFS 2例 )取材后电镜观察。结果 :11例AF中有 3例复发 ,复发率为 2 7 3% ,复发时间分别是术后半年、1年、10年。 3例AFS中 1例为原发 ,2例为AF恶变而来。组织病理学显示AF中成釉细胞上皮成分散布于富含纤维粘液样结缔组织中 ,间质成分主要为成纤维细胞 ,此外 ,可见组织样细胞和纤维组织样细胞及少量未分化间叶细胞。AFS中间质成纤维细胞密集增生 ,胞核浓染 ,核浆比例失调有明显异型性 ,其中 2例成釉细胞上皮成份明显减少或缺如。结论 :AF间质细胞具有一定的增殖活性 ,经各种刺激可恶变为AFS。AFS中的上皮减少和缺如可与间质细胞的过度增生恶变有关。AFS间质的细胞具有明显的恶性特征。

氟对大鼠成釉细胞GRP-78和caspase-12表达的影响

目的:研究GRP-78和caspase-12在氟致大鼠成釉细胞内质网应激和细胞凋亡中的作用,探讨氟所介导的内质网应激是否导致细胞凋亡。方法:应用CCK8和流式细胞术观察不同浓度的氟对成釉细胞活性及凋亡数量的影响,以实时定量PCR和Western印迹法检测氟对内质网伴侣分子GRP-78和caspase-12基因和蛋白表达的影响,应用SPSS13.0软件包对数据进行统计学分析。结果:随着氟浓度的不断增加,大鼠成釉细胞活性呈逐渐下降趋势,流式细胞术同样显示发生凋亡的细胞数量逐渐上升;实时定量RT-PCR和Western印迹结果显示,GRP-78和caspase-12的表达量随着氟浓度增加而增加。结论:过量氟介导了大鼠成釉细胞内质网应激,并且通过内质网应激,引起细胞凋亡。

氟对大鼠切牙成釉细胞内质网伴侣分子表达的影响

目的:研究不同浓度氟化物对大鼠切牙成釉细胞的影响,探讨内质网应激在氟斑牙形成中的作用。方法:30只Wistar大鼠随机分为3组,建立氟斑牙动物模型。观察大鼠切牙成釉细胞的形态学和GRP78、XBP-1、CRT和caspase-12表达的改变,采用MetaMorph显微图像分析软件和SPSS 13.0软件包对数据进行统计学分析。结果:随着饮水氟离子浓度的升高,切牙逐渐出现氟斑牙症状。免疫组化结果显示,CRT(F=11.72,P<0.05)、GRP78(F=27.42,P<0.05)、XBP-1(F=139.7,P<0.05)、caspase-12(F=43.91,P<0.05)表达随氟离子浓度的升高而升高,且各组间均具有显著性差异。结论:成釉细胞在一定浓度的氟化物作用下,其CRT、GRP78、XBP-1和caspase-12均过表达,表明成釉细胞处于内质网应激状态,且caspase-12是导致细胞凋亡的重要途径。

过量氟诱导成釉细胞钙超载及细胞凋亡的实验研究

目的研究过量氟对体外培养大鼠成釉细胞内钙超载及细胞凋亡的影响。方法取大鼠成釉细胞系HAT-7细胞,分别加入不同浓度(0、0.4、0.8、1.6、3.2、6.4 mmol·L-1)的氟化钠培养液,培养48 h后,采用Cell Counting Kit 8(CCK-8)试剂盒检测各组细胞的活性,流式细胞术分析氟对细胞凋亡的影响,激光扫描共聚焦显微镜、Western blot试验和实时荧光定量聚合酶链反应技术检测过量氟诱导大鼠成釉细胞内Ca2+浓度和钙网蛋白表达的变化。结果氟化钠浓度高于1.6 mmol·L-1时,可抑制成釉细胞的活性,成釉细胞内Ca2+浓度升高,钙网蛋白表达上调,细胞早期凋亡数量增加,并且随着浓度的增加,细胞凋亡的数量也随之增加。结论过量氟可引起成釉细胞内钙超载,诱导成釉细胞凋亡。

仔鼠成釉细胞氟中毒模型的建立及形态学观察

目的建立仔鼠成釉细胞氟中毒模型,为进一步研究氟牙症的发病机制提供实验基础。方法取体重为250g左右的雌、雄大鼠各3只,雌雄配对,每对同笼饲养,分别饲以含不同质量浓度氟化钠(0、50、100mg/L)的饮用水,至雌鼠受孕并产下仔鼠,分别在仔鼠出生第3天(成釉细胞分泌期)、第5天(成釉细胞成熟期)处死,用光学显微镜及透射电镜观察牙胚中成釉细胞的形态学变化及超微结构的改变。结果光镜观察可见:100mg/L组5d时仔鼠下颌骨牙胚中部分成釉细胞内空泡性变,部分成釉细胞与釉质基质间可见囊腔样损害。而0mg/L和50mg/L组牙胚成釉细胞中未见明显病变。透射电镜观察显示:100mg/L组和50mg/L组饲养3d和5d时仔鼠成釉细胞内均出现不同程度空泡状改变,内质网扩张、线粒体肿胀和细胞间间隙扩张,0mg/L组未见上述改变。结论通过给母鼠饮用不同浓度含氟饮水,可以使仔鼠成釉细胞中出现氟中毒样改变。

氟对体外培养大鼠成釉细胞HAT-7细胞活性和对细胞内Ca^(2+)浓度的影响

目的:观察氟对体外培养的大鼠成釉细胞HAT-7细胞活性及细胞内Ca2+浓度的影响。方法:取对数生长期的HAT-7细胞,分别加入不同浓度的Na F培养液,培养24、48、72 h后,用CCK-8检测细胞的活性;流式细胞术分析氟对细胞凋亡的影响;激光共聚焦显微镜检测细胞内钙离子的浓度。结果:Na F浓度为0.4、0.8 mmol/L时,促进成釉细胞增殖;当Na F浓度大于1.6 mmol/L时,促进成釉细胞凋亡,Na F浓度为1.6 mmol/L时,细胞早期凋亡数量增加,激光共聚焦显微镜检测证实,1.6mmol/L Na F可以诱导大鼠成釉细胞内Ca2+浓度升高,Na F对HAT-7细胞的上述作用与浓度和作用时间呈正相关。结论:低浓度氟促进HAT-7细胞增殖,高浓度则抑制其增殖。Na F浓度超过1.6 mmol/L时,可诱导成釉细胞凋亡,并诱导成釉细胞内Ca2+浓度增加。