Fine structural studies of radiation-resistant human squamous cell carcinomas.

Squamous cell carcinomas of the oral cavity are relatively common lesions, and often can be controlled by radiation therapy. Recently, a series of these tumors has been encountered which did not respond positively to irradiation, necessitating subsequent extensive surgery. This report describes some fine structural changes which were observed in squamous cell carcinomas following exposure to x-irradiation. In addition to the common, keratin-forming differentiated cell, others which were observed were secretory-like, undifferentiated and phagocytic cells. Undifferentiated tumor cells occasionally became incorporated, at least temporarily, as a component of the blood vessel wall, perhaps reflecting metastatic potentiality. It is proposed that irradiation may either increase potential avenues of tumor cell differentiation or inactivate inhibitors thereof.     

Effects of incision and irradiation on regional lymph node metastasis in carcinoma of the hamster tongue

The effects of incision and irradiation on regional lymph node metastasis in DMBA-induced squamous cell carcinomas of the hamster tongue are reported. Metastasis to the submandibular lymph nodes was confirmed histologically in 48.0% of the animals. The incidence of lymph node metastasis was significantly increased (65.9%) after repeated incisions of tongue carcinomas. Three gray whole-body irradiation also increased the rate of metastasis from 31.0% to 46.3%. Higher incidences of lymphatic vessel invasion after incision and concomitant lymph node metastasis in the lymphatic invasion-positive group indicated a stepwise relationship leading to an increase in lymph node metastasis after incision. Because of the high incidence of metastases and close resemblance to human carcinomas in the tumor cell deposition and establishment of metastatic foci, DMBA-induced tongue carcinoma with invasion may serve as an experimental model of human oral carcinomas.     

The myoepithelial cell differentiation of mucoepidermoid carcinoma in a collagen gel-based coculture model

BACKGROUND: Mucoepidermoid carcinomas (MECs) are the most common malignant tumor of the salivary glands; however, the histogenesis of MECs has been still controversial. This study was undertaken to investigate the histogenesis of MECs by the examination of their collagen gel-based coculture tissue and transplanted tumors. METHODS: Two cell lines from a primary and a metastatic MECs were established and characterized by the mutational analysis of the p53 gene and in vivo tumorigenicity in athymic nude mice. Collagen gel-based organotypic cocultures were performed, and the ultrastructural and immunohistochemical findings were examined. RESULTS: Two cell lines demonstrated p53 point mutation at the same codon. A metastatic cell line of MEC showed in vivo tumorigenicity. Transplanted tumors and the collagen gel-based culture tissues showed poorly differentiated squamous cell carcinomas devoid of mucous cell differentiation; however, they disclosed the differentiation of myoepithelial cells. CONCLUSIONS: MECs appear to be centered on the squamous cell differentiation, and the specific differentiation of myoepithelial or mucous cells seems to be modulated by the property of microenvironment.     

Cortactin expression in a Norwegian cohort of human papilloma virus negative oral squamous cell carcinomas of the mobile tongue

Oral squamous cell carcinoma of the tongue (OTSCC) is the most common malignancy among oral squamous cell carcinomas and is frequently associated with an unfavorable prognosis. Local spread and distant metastasis are important causes of poor prognosis in OTSCC. Cortactin amplification and overexpression, a common molecular alteration in oral squamous cell carcinomas, have been linked to invasion and metastasis of tumor cells. However, the intra-tumor expression pattern and prognostic significance of cortactin in human papillomavirus (HPV) negative OTSCC is not fully investigated. Immunohistochemical analysis using tissue microarray consisting of formalin-fixed and paraffin-embedded HPV negative OTSCC (n = 123) specimens showed overexpression of cortactin at tissue cores from invading fronts as compared to the corresponding center cores. High overall cortactin expression was found to be associated with advanced (larger) tumor size and the occurrence of distance metastasis. Kaplan-Meier survival analysis showed that patients with high overall cortactin expression were associated with reduced 5-year survival. Multivariate Cox regression analysis identified high cortactin expression to be an independent prognostic factor in OTSCC. Additionally, siRNA-mediated silencing of cortactin was found to suppress the proliferative and invasive abilities of OTSCC cells in an organotypic co-culture model. Overexpression of cortactin is a promising prognostic marker in HPV-negative OTSCC.     

TNP-470作用于体外培养GNM细胞系的形态学研究

目的:观察TNP-470作用于体外培养的人口腔鳞癌颈淋巴结转移癌细胞系GNM后的形态学改变,探讨TNP- 470的作用机理。方法:利用体外培养技术,采用相差显微镜、扫描电镜、透射电镜观察法,观察TNP-470对GNM细胞形态及超微结构的影响。结果:TNP-470(2Lg/ml)作用于GNM细胞48 h,大量细胞变圆、细胞膜皱缩,并出现较多悬浮死亡细胞。作用72 h后,扫描电镜下可见细胞表面的微绒毛数量减少、长度变小、细胞一端有较大的球状突; 透射电镜下可见GNM细胞大量坏死、线粒体和内质网破坏。结论:TNP-470对GNM细胞具有明显杀伤作用;TNP- 470可使GNM细胞线粒体和内质网发生破坏,这可能是其具有直接癌细胞毒作用的机制之一;TNP-470可使GNM 细胞膜表面结构发生改变。     

Lactate dehydrogenase isoenzymes in squamous cell carcinomas of the oral cavity

Lactate dehydrogenase (LDH; EC 1.1.1.27) isoenzymes in human epithelial cells from squamous cell carcinomas and healthy tissues of the oral cavity of five patients were analyzed using isoelectric focussing. A new basic isoenzyme and high LDH-7 and LDH-9 activity were found in tumor cells in contrast to epithelial cells of adjoining nontumor tissue. These findings indicate that gradual changes in the percentage distribution of LDH isoenzymes may represent a useful parameter of disease activity in patients with squamous cell carcinomas.     

颌下三角区原发性恶性肿瘤

目的 :探讨颌下三角区原发性恶性肿瘤的诊断和治疗的特殊性 .方法 :回顾性分析我院 1984年 1月至 1993年 12月收治的 37例颌下三角区原发性恶性肿瘤患者的临床资料 ,其中腺样囊性癌 11例 ,低度恶性粘液表皮样癌 9例 ,中度恶性粘液表皮样癌 4例 ,恶性混合瘤 3例 ,鳞癌 4例 ,腺癌 2例 ,未分化癌 3例 ,颌下腺导管癌 1例 .所有患者均作手术切除 ,并根据其不同的组织病理特征选择其中 2 4例术后辅助放射治疗 .结果 :本组病例随访3年～ 5年 ,术后 3年生存率为 89.1% 33/ 37 ,5年为 81% 30 / 37 .结论 :颌下三角区原发性恶性肿瘤具有一定的临床特征 ,如 : 1 肿瘤生长较快 ; 2 可伴有局部疼痛 ; 3 可有同侧舌麻、舌痛现象 .治疗以手术切除为主 .根据肿瘤的不同组织病理学特征 ,术后辅助放射治疗 ,可提高疗效。     

口腔黏膜癌前病变癌变过程中端粒酶逆转录酶mRNA和增殖细胞核抗原的表达及其相关性

目的　探讨人端粒酶逆转录酶 (hTERT)mRNA和增殖细胞核抗原 (PCNA)在口腔黏膜癌前病变癌变发生发展中的作用 ,以及hTERTmRNA与PCNA蛋白表达之间的关系及意义。方法　应用原位杂交和免疫组化法对口腔黏膜单纯性增生 (HP)9例 ,轻度异常增生 (LD) 11例 ,中度异常增生 (MD) 10例 ,重度异常增生 (即原位癌 ,CIS) 9例 ,鳞癌 (SCC) 11例 ,进行hTERTmR NA及PCNA蛋白检测 ,结果应用计算机图像分析系统分析。结果　口腔黏膜上皮从HP、LD、MD到CIS、SCC ,hTERT、PCNA蛋白的阳性细胞面积指数及吸光度 (A)值均逐渐上升 ,鳞癌最高。在HP及LD ,hTERT、PCNA阳性细胞主要位于基底层 ,但随着细胞异常增生程度的加重 ,阳性表达细胞从基底层向角化层进展。在高分化鳞癌中 ,主要分布在癌巢周边 ,分化较差的鳞癌则散布于整个肿瘤组织中。PCNA与hTERTmRNA表达呈线性正相关。结论　hTERT与PCNA均参与口腔黏膜癌前病变癌变的发生发展过程 ;PCNA与hTERTmRNA表达的正相关 ,表明hTERT激活细胞多处于高增殖状态。     

Karyotypic abnormalities of squamous cell carcinoma of the oral cavity

The karyotypic abnormalities in 18 squamous cell carcinomas of the oral cavity were studied in unhanded chromosomes on direct preparations of the tumor material. The chromosome counts revealed a great variability in the number of chromosomes per cell of each tumor, the range being from 31 to 148 in all cases studied. The modal population of cells was diploid in five cases, triploid in eight cases, tetraploid and pentaploid in one case each. Reduction of the number of chromosomes was more consistently observed in groups A and B, frequently involving chromosome No 1 and increases in groups C, D, E, F and G. Markers were frequently present, the most common being an almost metacentric chromosome of the size of the chromosomes of Group C.     

Karyotypic abnormalities of squamous cell carcinoma of the oral cavity

The karyotypic abnormalities in 18 squamous cell carcinomas of the oral cavity were studied in unbanded chromosomes on direct preparations of the tumor material. The chromosome counts revealed a great variability in the number of chromosomes per cell of each tumor, the range being from 31 to 148 in all cases studied. The modal population of cells was diploid in five cases, triploid in eight cases, tetraploid and pentaploid in one case each. Reduction of the number of chromosomes was more consistently observed in groups A and B, frequently involving chromosome No 1 and increases in groups C, D, E, F and G. Markers were frequently present, the most common being an almost metacentric chromosome of the size of the chromosomes of Group C.     

Vimentin expression and the influence of Matrigel in cell lines of head and neck squamous cell carcinoma

Vimentin is a cytoeskeletal intermediate filament protein commonly observed in mesenchymal cells; however, it can also be found in malignant epithelial cells. It is demonstrated in several carcinomas, such as those of the cervix, breast and bladder, in which it is widely used as a marker of the epithelial to mesenchymal transition that takes place during embryogenesis and metastasis. Vimentin is associated with tumors that show a high degree of invasiveness, being detected in invasion front cells. Its expression seems to be influenced by the tumor microenvironment. The aim of this study was to evaluate vimentin expression in head and neck squamous cell carcinoma (HNSCC) cell lines, and to investigate the contribution of the microenvironment to its expression. HNSCC cell lines (HN6, HN30 and HN31) and an immortalized nontumorigenic cell line (HaCaT) were submitted to a three-dimensional assay with Matrigel. Cytoplasmatic staining of the HN6 cell line cultured without Matrigel and of the HN30 and HN31 cell lines cultured with Matrigel was demonstrated through immunohistochemistry. Western Blotting revealed a significant decrease in vimentin expression for the HN6 cell line and a significant increase for the HN30 and HN31 cell lines cultured with Matrigel. The results suggest that vimentin can be expressed in HNSCC cells and its presence is influenced by the microenvironment of a tumor.     

Evaluation of myofibroblasts in oral epithelial dysplasia and squamous cell carcinoma

Background:  Carcinogenesis is accompanied by a number of changes in the adjacent stroma including the appearance of myofibroblasts. The purpose of this study was to evaluate and compare the presence of myofibroblasts in normal mucosa, oral epithelial dysplasia, and different grades of oral squamous cell carcinoma.
Methods:  The study sample consisted of three groups, including 40 oral squamous cell carcinomas, 15 dysplasias, and 15 sections of normal oral epithelium. Vimentin, desmin, and alpha-smooth muscle actin were used to identify myofibroblasts.
Results:  The percentage and intensity of alpha-smooth muscle actin were examined, and positive immunostaining was observed in the myofibroblasts of all squamous cell carcinomas; however these cells did not stain in the dysplasias or normal epithelium specimens. The presence of myofibroblasts was significantly higher in oral squamous cell carcinomas compared to both, dysplasias and normal mucosa cases ( P  < 0.001). A significant difference was not observed between the different grades of oral squamous cell carcinoma ( P  = 0.2).
Conclusions:  These findings show the presence of myofibroblasts in the stroma of oral squamous cell carcinoma but not dysplasia and normal mucosa, suggesting further investigation to clarify the role of myofibroblasts in the carcinogenesis of this tumor.     

Customized mold brachytherapy for oral carcinomas through use of high-dose-rate remote afterloading apparatus

OBJECTIVE: The aim of this study was to investigate the role of the combined use of customized molds and recently available remote afterloading brachytherapy apparatus with more flexible catheters in the treatment of superficial oral carcinomas. STUDY DESIGN: Four patients with oral squamous cell carcinoma who were treated through use of this combined technique were analyzed retrospectively. The molds were made from transparent acrylic resin through use of a dental technique. The combined approach was applied as a boost therapy after external irradiation. RESULTS: The 4 patients had had no recurrence of tumor or radiation injury by the end of the follow-up period. CONCLUSIONS: The combined technique could be an excellent method of treating superficial carcinomas of the oral cavity.     

Antioxidant enzyme levels in oral squamous cell carcinoma and normal human oral epithelium

BACKGROUND: The antioxidant enzymes (manganese- and copper-zinc-containing superoxide dismutases, catalase and glutathione peroxidase) limit cell injury induced by reactive oxygen species. The purpose of the study was to determine whether human oral squamous cell carcinomas have altered antioxidant enzyme levels. This study is the first to undertake this task in human oral mucosa and squamous cell carcinoma. METHODS: Semiquantitative immunohistochemistry was used to examine 26 archived oral squamous cell carcinoma biopsies. Fourteen well-differentiated and 12 poorly differentiated tumors were examined, as were 12 specimens of oral mucosa. All sections were reviewed by two oral and maxillofacial pathologists, and image analysis of the immunostained sections was performed using NIH Image. Antioxidant enzyme staining intensities were compared in the different groups by Duncan's multiple range test. RESULTS: In general, mucosal basal cells displayed lower antioxidant enzyme levels than spinous cells, and primary tumor cells displayed lower antioxidant enzyme staining intensities than did their normal cell counterparts. Moreover, poorly differentiated tumor cells showed lower antioxidant enzyme staining intensities than well-differentiated tumor cells. Manganese-containing superoxide dismutase staining intensities were, however, higher in well-differentiated oral squamous cell carcinomas than their normal cells of origin. CONCLUSIONS: Detection of antioxidant enzymes may be a useful future marker in the molecular diagnosis of the oral cancer. Moreover, it may be possible to not only monitor the effectiveness of chemopreventive and therapeutic strategies in oral cancer using these enzymes, but to monitor tumor recurrence.     

Cytoplasmic expression of p53 protein and its morphological features in salivary gland lesions

An immunohistochemical study of p53 protein was carried out on 45 salivary gland lesions using a monoclonal antibody, Bp53–12, raised to the intracellular domain of the p53 protein. p53 protein expression was found in 34.4% of 32 salivary gland carcinomas. Nuclear p53 expression was detected in tumor cells but not in non-neoplastic cells, except in one salivary duct carcinoma. The perinuclear cytoplasm of luminal duct cells was specifically positive for the antibody used here. Cytoplasmic p53 expression was observed mostly in non-neoplastic cells. There was a tendency for the Cytoplasmic staining of p53 protein to be observed in the normal cells adjacent to p53-positive carcinomas, but none of the normal cells were positive in the tissues surrounding p53-negative carcinomas. Cytoplasmic expression of p53 protein in salivary gland tissues seems to be correlated with tumorigenesis.     

The effect of chemotherapeutic agents on human oral squamous cell carcinoma transplanted to nude mice: a histologic study

Clearly differentiated squamous cell carcinomas were transplanted to the backs of nude mice; tumor cells of a human tongue carcinoma cell line were used. Animals bearing tumors that measured at least 4 mm in diameter were treated with either methotrexate (MTX), cis-diamminedichloroplatinum II (CDDP) or bleomycin intraperitoneally for 5 days. Histologic evaluation of tumors obtained 24 hours after the last injection revealed degenerative and necrotic morphology in all treatment groups. The histologic alterations were observed prior to any clinical evidence of tumor shrinkage. The most impressive changes were found in CDDP-treated tumors, with creation of large pseudocysts containing necrotic material and cell debris. Pseudocyst formation was less obvious in MTX-treated animals and was absent in bleomycin-treated tumors. Drug treatment had no obvious influence on the keratinization in tumors. The findings suggest that the nude mouse model may be useful for the histologic determination of drug-induced effects on tumors in human beings.     

A qualitative and quantitative electronmicroscopic study of the structure of the adenoid cystic carcinoma of human minor salivary glands.

The fine structural characteristics of five adenoid cystic carcinomas of human minor salivary galnds and a quantitative assessment of the relative volumes occupied by morphologically defined cell types in these tumors are reported. We observed that the cyst-like spaces which give the characteristic cribriform pattern to the adenoid cystic carcinoma contain replicated basement membrane-like materail. Material comprisimg aggregates of fine tubules having a median diameter of 270 A, and rounded, electron dense bodies were noted within duct-like lumena of one tumor. In addition, dilatation of the intercellular spaces and squamous metaplasia were noted. From 500 electronmicrographs obtained by standardized techniques and used for the morphological part of the study, 175 were selected by a random sampling method and analyzed by the stereological technique of point counting. This method demonstrated that duct type cells occupied 75% by volume of the tumor in these glands; myoepithelial cells occupied 3%, acinar cells occupied 2%, and other tissues occupied 22% of the tumors. These proportions differ significantly (P less than 0.001) from our previously published figures for normal specimens of these glands.     

阿霉素磁性介孔氧化硅纳米颗粒对口腔鳞状细胞癌细胞的体外实验研究

目的:探讨阿霉素磁性介孔氧化硅纳米颗粒(Doxorubicin-loading Mesoporous Magnetic Silia Nanoparticles,DOX@M-MSNs)对口腔鳞状细胞癌细胞的体外靶向杀伤作用。方法:采用甲基噻唑基四唑(MTT)法,流式细胞仪及激光共聚焦显微镜检测DOX@M-MSNs对CAL-27的体外靶向抗肿瘤效果。结果:单纯磁性介孔氧化硅纳米颗粒表现出非常好的生物稳定性以及生物相容性,尽管浓度为100 mg/L时,细胞存活率仍超过80%。当浓度值有所提升及作用时间延长后,相较于单纯阿霉素原料组,DOX@M-MSNs对于肿瘤细胞的增殖抑制作用明显增强,差异有统计学意义(P<0.05)。流式细胞仪检测结果显示DOX@M-MSNs促进肿瘤细胞的凋亡率高于单纯阿霉素,随着药物作用时间延长,其对肿瘤细胞的抑制效果明显增强,凋亡率增高。激光共聚焦显微镜检测结果显示通过外加磁场,磁性区域的DOX@M-MSN释放的DOX于肿瘤细胞的聚集优于非磁性区域。结论:DOX@M-MSNs纳米颗粒能够选择性进入肿瘤细胞内,从而使得阿霉素对肿瘤细胞的毒性有所增强,进而使得其杀伤肿瘤细胞的效果显著提高,外加磁场可以显著地提升输送DOX@M-MSNs进到肿瘤细胞内的效率,进而提高肿瘤抑制效果。