Expression of p53 protein and tumor angiogenesis as prognostic factors in nasopharyngeal carcinoma patients

The objective of this study was to evaluate the possible prognostic significance of p53 protein overexpression and tumor angiogenesis (TA) in nasopharyngeal carcinoma (NPC) patients, together with other clinicopathological variables. Forty-two NPC patients were evaluated in relation to survival. Nuclear p53 overexpression in neoplastic and endothelial cells was detected by immunohistochemistry (IHC) with the monoclonal antibody DO-7 and the polyclonal antibody against factor VIII-related antigen, respectively. Thereafter, we evaluated p53 cases in order to determine their nuclear immunoreactivity from negative (-) to positive (+, ++, +++). In addition, microvessels were counted in the most active areas of tumor neovascularization or hotspots using an image computer analyzer (MicroImage). A Cox multiple regression survival analysis was used to determine the best prognostic indicators in NPC patients. As a result, tumor microvessel count, considered as a continuous variable, was the most important independent prognostic indicator in relation to survival (p = 0.0273), with a relative risk of death of 2,4399 [95% confidence interval = 1.1051 ; 5.3871] associated with the highest microvessel counts. Moreover, the only clinicopathological variable that demonstrated prognostic value in a Cox multiple regression survival analysis was histological type (p = 0.05). In addition, we did not observe any statistical association between intratumoral microvessel density (IMD), clinicopathological variables and p53 protein expression.     

Immunohistochemical study of nasopharyngeal carcinoma using monoclonal keratin antibodies

Nasopharyngeal carcinoma (NPC) provides a unique opportunity to evaluate distinctive epidemiologic features and a possible etiologic relationship with Epstein-Barr virus (EBV) in human malignancy. The lack of a uniformly accepted pathologic classification for NPC has limited the application of this data, although the World Health Organization (WHO) developed a classification that may solve this problem. Monoclonal keratin antibodies were used for staining of NPC for evaluation of its assistance in diagnosis and classification. In the present immunohistochemical study, monoclonal keratin antibodies, designated AE1, AE2, and AE3, and a polyclonal keratin antibody (RAK) were used for study of the presence of keratin in 121 cases of NPC obtained from China and the United States. AE1 monoclonal antibody, which recognizes keratin protein classes 56.5K, 50K, and 40K, was shown to be the most sensitive and specific for NPC tumor cells among the keratin antibodies studied. In addition, some different keratin expression patterns could be identified between different kinds of epithelium and different tumor groups, with possible relevance to the histogenesis of the histologic subtypes of NPC.     

A monoclonal antibody detecting the adenovirus type 5 E 1 b-58Kd tumor antigen: Characterization of the E 1 b-58Kd tumor antigen in adenovirus-infected and -transformed cells

A monoclonal antibody directed against the adenovirus type 5 Elb-58Kd tumor antigen has been isolated. Immune clearing experiments were employed to demonstrate that this monoclonal antibody detects the same Elb-58Kd antigen observed previously with polyclonal antisera from hamsters bearing adenovirus-induced tumors. Fluorescent antibody tests using the monoclonal antibodies directed against the Elb-58Kd antigen localized the viral protein predominantly in the nucleus of virus-infected and -transformed cells. The monoclonal and polyclonal tumor sera detected similar protein species in virusinfected and -transformed cells. In adenovirus productively infected human cells the monoclonal antibody and polyclonal tumor sera both detected a 25Kd protein in addition to the Elb-58Kd antigen. In transformed mouse and hamster cells this monoclonal and polyclonal antisera coimmunoprecipitated a 53Kd cellular protein along with the Elb58Kd antigen. This 53Kd cellular protein is similar to the p53 antigens detected in a variety of transformed cells.     

Sarcomatoid carcinoma of the breast: An immunohistochemical study of six cases

Summary Six cases of sarcomatoid carcinoma of the breast (SCB) were studied with a panel of anti-bodies directed against epithelial and sarcomatoid components. The monoclonal antibodies (MoAb) AE-1/3, CAM 5.2, and CEA were used to detect epithelial differentiation; polyclonal antibodies against S-100 protein and MoAb against the intermediate filaments desmin and vimentin were used to detect mesenchymal differentiation in the sarcomatoid component. Six cases of invasive duct carcinoma (IDC) and two cases of cystosarcoma phyllodes (CP) were compared to SCB using the same panel of antibodies. In all three groups studied, the epithelial component in the majority of cases stained with anti-cytokeratin antibodies. S-100 protein antibodies stained the epithelial and sarcomatoid components in four cases of SCB; vimentin MoAb stained the epithelium in two cases and the sarcomatoid component in four cases of SCB, while MoAb CEA failed to stain any component of SCB. In contrast, the epithelium in five of six cases of IDC stained with CEA MoAb and only one of six stained for S-100 protein. Possible reasons for the discrepant immunohistochemical staining patterns among SCB, IDC and CP are discussed, in addition to the limitations and pitfalls of immunohistochemistry in diagnostic surgical pathology.     

Comparative analysis of the expression of the Epstein-Barr virus (EBV) anti-apoptotic gene BHRF1 in nasopharyngeal carcinoma and EBV-related lymphoid diseases

Epstein-Barr virus (EBV) has been identified in a wide range of neoplastic and non-neoplastic disorders. The EBV open reading frame BHRF1 encodes a protein with partial sequence and functional homology to the anti-apoptotic onco-protein Bcl-2 and may therefore have a role in the proliferation of EBV positive cells. We have developed a rat monoclonal antibody against pBHRF1, which can detect BHRF1 in paraffin sections. While a number of mutant versions of BHRF1 were recognised, the monoclonal did not detect the BHRF1 homologue encoded by Herpesvirus papio or two mutants with deletions in the BH2 region. This novel rat monoclonal antibody (6A9) was used to examine tissue sections from 39 cases of non-keratinising undifferentiated nasopharyngeal carcinoma (NPC), 6 cases of metastatic NPC, 7 cases of EBV-positive NPC with squamous differentiation from Chinese patients, 15 cases of EBV-positive post-transplant lymphoproliferative disorder (PTLD), 6 EBV-containing lymphoblastoid cell lines, and 2 cases of oral hairy leukoplakia (OHL). In 11 cases of undifferentiated NPC, RT-PCR data were available for comparison with the immunohistochemistry. Both cases of OHL and two cases of LCL were positive for BHRF1 but none of the PTLD showed positive staining. All cases of undifferentiated NPC were positive for Bcl-2 but only one BHRF1 positive cell was identified in 1 of 39 cases of primary undifferentiated NPC. The 6A9 antibody produced less background staining and no nuclear positivity compared with the commercially available mouse monoclonal 5B11. It is concluded that BHRF1 can not be detected by immunohistochemistry in NPC and therefore it appears not to play a significant anti-apoptotic role in the progression of this EBV-associated tumour. The 6A9 monoclonal appears to be superior to 5B11 for the detection of pBHRF1 in tissue sections.     

Diagnostic value of OCT3/4 for pre-invasive and invasive testicular germ cell tumours

Human testicular germ cell tumours of adolescents and adults (TGCTs), the seminomatous and non-seminomatous germ cell tumours, show morphological and biological similarities to normal embryonic development, presumably determined by their supposed cell of origin, the primordial germ cell/gonocyte. Based on this knowledge, OCT3/4, also known as POU5F1, was recently defined as a diagnostic marker for these tumour types. In the adult testis, positive immunohistochemistry for OCT3/4 is an absolute indicator for the presence of the TGCT precursor carcinoma in situ/intratubular germ cell neoplasia undifferentiated (CIS/ITGCNU), seminoma, and/or embryonal carcinoma. Several studies have confirmed this observation, using the same polyclonal antibody. The present study demonstrates the usefulness of OCT3/4 immunohistochemistry in a diagnostic setting of a consecutively collected series of more than 200 testicular tumours and over 80 testicular biopsies. Moreover, it is shown that a monoclonal antibody directed against OCT3/4 is as informative as the polyclonal antibody, both in immunohistochemistry and in western blot analysis. The antibodies are robust and applicable with different methods of pretreatment and storage of tissue. This allows routine application of this diagnostic marker.     

The Niemann-Pick C1 protein in feline fibroblasts

Niemann-Pick type C (NPC) disease is a rare inherited metabolic disorder characterized by hepatosplenomegaly, progressive neurodegeneration, and storage of lipids such as cholesterol and glycosphingolipids in most tissues. The current study was conducted to characterize the Niemann-Pick C1 (NPC1) protein in feline fibroblasts. This was accomplished by generating rabbit polyclonal antibodies against a peptide corresponding to amino acids 1256-1275 of the feline NPC1 protein. The results obtained using immunoblot analysis identified two major proteins that migrated at approximately 140 and 180 kDa. These two proteins were absent when immunoblots were incubated in the presence of feline NPC1 antibody and immunizing peptide, or preimmune serum. Fluorescence microscopy of feline fibroblasts incubated with the feline NPC1 antibody revealed granular staining within the perinuclear region of the cell. This granular staining was diminished when feline fibroblasts were incubated in the presence of feline NPC1 antibody and immunizing peptide, or was completely absent when feline fibroblasts were incubated in the presence of preimmune serum. Additional studies using double-labeled fluorescence microscopy indicated that feline NPC1 partially colocalized with markers for late endosomes/lysosomes, endoplasmic reticulum, and microtubules, but not the trans-Golgi network. In summary, the results presented in this report demonstrate that the NPC1 protein in feline fibroblasts has a similar distribution as that previously described for human and murine fibroblasts.     

Detection of p53 overexpression in routinely paraffin-embedded tissue of human carcinomas using a novel target unmasking fluid.

With the aid of a newly developed target unmasking fluid (TUF), p53 overexpression was visualized by immunohistochemistry on recent and archival paraffin-embedded tissue samples of colon, stomach, and pancreas neoplasms. Using monoclonal anti-p53 antibody pAb1801 as well as polyclonal antiserum to p53 CM1, TUF-mediated immunohistochemistry was fully concordant for p53 overexpression in paraffin-embedded carcinoma samples compared with freshly frozen tissue from the same tumors. Thus, prognostic and diagnostic assessment of p53 overexpression in malignant tissue, routinely fixed in formalin and embedded in paraffin wax, by TUF-mediated immunohistochemistry with monoclonal and polyclonal antibodies may be adopted as a new tool in diagnostic and research histopathology.     

Association of Epstein-Barr virus infection with p53 protein accumulation but not bcl-2 protein in nasopharyngeal carcinoma

AIMS: The aim of this study was to investigate the association of Epstein-Barr virus (EBV) infection with status of p53 protein expression in nasopharyngeal carcinoma (NPC). The expression of EBV gene and gene product, p53 protein and bcl-2 protein in NPC was histopathologically studied. METHODS AND RESULTS: In-situ hybridization using oligonucleotide probe to EBV-encoded small RNAs (EBERs) and immunohistochemistry using monoclonal antibodies against EBV latent membrane protein 1 (LMP1), p53 protein and bcl-2 proteins were performed in 56 primary NPCs. EBERs were detected in 46 (82%) cases and LMP1 in 17 (30%) cases. While 30 of 32 (94%) cases in differentiated nonkeratinizing carcinoma (NKC, WHO type 2) and 16 of 17 (94%) cases in undifferentiated carcinoma (UC, WHO type 3) showed EBERs expression, neither five cases of keratinizing squamous cell carcinoma (KSCC, WHO type 1) nor two cases of adenocarcinoma showed EBERs. bcl-2 protein was detected in 50 (89%) cases, but its expression did not depend on expression of LMP1. p53 protein was detected in 31 (55%) cases, and there was a correlation between expression of EBERs and p53 protein (P < 0.05) but not between LMP1 and p53 protein. CONCLUSION: In this study, close association of NKC and UC but not KSCC with the latent infection with EBV was demonstrated. The induction of bcl-2 protein by LMP1, as shown in vitro, was not demonstrated. The association between overexpression of p53 protein and the presence of EBV suggests that some EBV-encoded protein, which may be different from LMP1, may play a role for nuclear accumulation of p53 protein.     

16层螺旋CT图像后处理技术在鼻咽部肿瘤诊断中的临床应用

目的探讨16层螺旋CT图像后处理技术在鼻咽部肿瘤诊断中的临床应用价值。方法对本院123例鼻咽部肿瘤患者行16层CT扫描后进行图像后处理，结合轴扫资料，与鼻咽纤维镜和活检病理所见对照分析。结果与轴扫资料对比，采用后处理图像提供病变细节，增加诊断信息43例；复杂部位病变准确定位15例；直观显示病变范围及其与周围组织关系60例；无明显增加诊断信息5例。结论鼻咽部16层螺旋cT图像后处理技术可有效增加和提高轴扫CT诊断信息及临床应用价值。     

CD146 protein in prostate cancer: revisited with two different antibodies

AIMS: CD146 is a potentially metastasis promoting cell adhesion molecule and its expression has been described in various solid tumours. We aimed to evaluate the expression of CD146 in prostate cancer by immunohistochemistry in a clinically characterised study cohort to evaluate its prognostic properties. METHODS: We evaluated the CD146 protein expression using a polyclonal and a monoclonal antibody on 169 clinico-pathologically characterised cases. Statistical analyses were applied to test for correlations and diagnostic and prognostic associations. RESULTS: CD146 detection with the polyclonal antibody revealed marked differential expression between tumour and normal tissue and was also a significant marker for shortened PSA relapse free survival. The monoclonal CD146 antibody demonstrated a weaker epithelial signal, which was significantly correlated with that of the polyclonal antibody, but revealed no prognostic value. However, the Western blot of the polyclonal antibody displayed a clearly reduced specificity. CONCLUSIONS: Evaluation of protein expression can be highly dependent on the primary antibody employed. A credible evaluation of antibody specificity is crucial to prove the validity of protein expression studies. The immunoreactivity of the polyclonal CD146 antibody (Abcam, ab28360) is prognostic of PSA-relapse in prostate cancer patients, although its immunoreactivity is possibly not restricted to CD146 associated epitopes.     

鼻咽癌细胞凋亡与细胞毒淋巴细胞和LMP—1表达之间的关系

目的 :探讨鼻咽癌细胞凋亡与肿瘤内细胞毒淋巴细胞和LMP 1表达之间的关系。方法 :收集未经治疗的鼻咽癌活检组织 38例 ,采用TUNEL法定量检测鼻咽癌细胞凋亡程度 ,用免疫组化法检测肿瘤细胞LMP 1表达情况和肿瘤内TIA 1+细胞毒淋巴细胞数。结果 :(1) 38例鼻咽癌组织学分为角化性鳞癌 7例 ,非角化性癌 8例 ,未分化癌 2 3例。平均凋亡指数分别为72 3、74 6和 30 7。角化性鳞癌和非角化性癌与未分化癌相比 ,差异有显著性 (P <0 0 5 ) ;(2 ) 38例中LMP 1阳性病例 19例 ,占 5 0 %。除外角化性鳞癌后 ,LMP 1阳性组平均凋亡指数为 5 1 7,高于LMP 1阴性组的 37 3,差异有显著性 (P <0 0 5 ) ;(3)每 10 0 0个癌细胞范围内浸润的TIA 1+细胞数为 3～ 75个 ;在角化性鳞癌中平均 12 ,低于非角化性癌和未分化癌 (平均2 1 4) ,差异有显著性 (P <0 0 5 ) ;除外角化性鳞癌后 ,TIA 1+细胞数多者凋亡指数较高 (r =0 40 47,P <0 0 5 )。结论∶(1)鼻咽癌细胞凋亡程度在不同组织学类型中差异有显著性 ;(2 )鼻咽癌组织内TIA 1+细胞数在不同的组织学类型中有差别 ;(3)非角化性鼻咽癌组织中 ,LMP 1阳性者凋亡指数高 ,TIA 1+细胞数多者凋亡指数高。说明细胞毒淋巴细胞和LMP 1的表达具有促进鼻咽癌细胞凋亡的作用。     

Toker cells are probably precursors of Paget cell carcinoma: a morphological and ultrastructural description

The present paper documents an investigation of the morphology, immunohistochemistry, and ultrastructure of Toker cells (TC), aiming for a better definition of these elements and better understanding of their histogenesis. We studied 12 nipples removed for nipple adenoma from twelve patients and a case of supernumerary nipple. In addition four cases of Paget's carcinoma (PC) restricted to the nipple without underlying tumor were studied for comparison. All cases were stained with hematoxylin and eosin (H&E), Alcian blue pH 2.5 and periodic acid-Schiff (PAS) preceded by diastase digestion and with immunohistochemistry using antisera anti cytokeratin 7, cytokeratin 20, protein S100, GCDFP-15, c-Erb-B2, CAM 5.2, and epithelial membrane antigen (EMA). Two cases from the nipple adenoma series were studied by electron microscopy. In seven cases within the series of 12 nipple adenomas as well as in the case of supernumerary nipple, keratin 7 antibody highlighted numerous cells located within the nipple epidermis which in three cases showed dendritic processes. These same elements were also positive with CAM 5.2. All these same elements were negative with Alcian Blue (AB), PAS and the other antisera employed. Ultrastructural examination demonstrated that these cells differed from keratinocytes while they presented the same features as the glandular cells seen in the related nipple adenoma. The cells constituting Paget's carcinoma showed more irregular nuclei and were more easily seen in the context of the epidermis. The immunocytochemical profile of the cancer cells was similar to that of TC, but in addition the neoplastic cells were c-Erb-B2 and EMA positive in all cases, and one case also displayed numerous cells immunoreactive with anti GCDFP-15 antibody. Keratin 7 highlighted dendritic cells in two cases and AB, PAS was negative in all patients. The immunocytochemical profile and the ultrastructural features of TC are similar to those of the glandular cells constituting the ducts and the adenoma. These findings together with the localization of TC near or around the openings of the lactiferous sinuses indicate that TC might be ductal cells with a dendritic aspect and migrate through the galactophorous ostia. PC cells not related to ductal carcinomas have a similar but not superimposable immunohistochemical profile to TC, and in two cases the neoplastic elements were also dendritic which suggests that these same cells are likely to be the neoplastic counterpart of TC.     

Clinicopathological significance of TUBB3 in upper tract urothelial carcinoma and possible application in urine cytology

βIII-Tubulin, encoded by the TUBB3 gene, is a microtubule protein. We previously reported that TUBB3 is overexpressed in renal cell carcinoma. We investigated the clinicopathological significance of TUBB3 in upper tract urothelial carcinoma (UTUC) by immunohistochemistry. In normal tissue, TUBB3 expression was weak or absent. In contrast, TUBB3 overexpression was observed in urothelial carcinoma (UC) tissues in 51 (49%) of 103 UTUC cases. TUBB3 overexpression was associated with nodular/flat morphology, high-grade disease, high T stage, and a poor prognosis. Similar results were obtained in The Cancer Genome Atlas bladder cancer cohort. TUBB3 expression was also associated with high Ki-67 labeling index, CD44v9, HER2, EGFR, and p53 expression in UTUC. Among representative cancer-related molecules, TUBB3 was an independent predictor of progression-free survival and high-grade UC. Finally, using urine cytology samples, we analyzed TUBB3 expression by immunocytochemistry. TUBB3 expression was more frequently found in UC cells than in nonneoplastic cells. The diagnostic accuracy of urine cytology was improved when combined with TUBB3 immunostaining. The findings suggest the importance of TUBB3 in tumor progression and its potential application as a biomarker for high-grade disease and the prognosis of UC. Moreover, combination with TUBB3 immunostaining might improve the diagnostic accuracy of urine cytology.     

Usefulness of Electron Microscopy in the Diagnosis of “Small” Round Cell Tumors of the Sinonasal Region

The sinonasal region is known to harbor several types of tumors that belong to the general category of “small” round cell tumors and offer considerable diagnostic challenges. This study evaluated 33 cases of such tumors by electron microscopy to characterize their ultrastructural features in conjunction with immunohistochemistry, in an attempt to define diagnostic criteria of various types. Electron microscopy was useful in the proper classification of tumors in 27 cases: esthesioneuroblastoma (EN), 12; undifferentiated carcinoma, 6; melanoma, 3; lymphoma, 3; melanotic neuroectodermal tumor, 1; rhabdomyosarcoma, 1; and pituitary adenoma, 1. In the remaining six cases, the ultrastructural features were those of poorly differentiated carcinomas. They usually exhibited some epithelial characteristics as well as neuroendocrine features by immunohistochemistry and electron microscopy. These tumors could be best described as poorly differentiated neuroendocrine carcinomas (malignant neuroepitheliomas). The most controversial diagnostic problems existed between the tumors categorized as esthesioneuroblastomas and neuroendocrine (NE) carcinomas. Esthesioneuroblastomas were characterized by uniform round nucleated cells with variable amounts of dendritic processes containing numerous dense core granules ranging from 150 to 350 nm in the perikarya and dendritic processes. Dendritic processes contained longitudinally arranged neural tubules and revealed an occasional synaptic junction. In three of the 12 cases of EN, cells with the appearance of sustentacular cells were recognized by electron microscopy. The NE carcinomas usually consisted of closely packed round cells with scanty cytoplasm that lacked any feature of neuroblastic cells. The tumor cells in this category often were epithelioid in appearance and exhibited a varying degree of cytokeratin positivity. Neuron-specific enolase was also positive in all cases, further suggesting their neuroepithelial nature. The greatest difference between EN and NE carcinomas was the absence of sustentacular cells in NE carcinomas. Immunohistochemical and electron microscopic studies are essential in the differential diagnosis of EN and NE carcinomas, because their microscopic appearance is very similar. The study indicates that EM is useful in the diagnostic categorization of sinonasal tumors of uncertain nature, particularly when it is used in conjunction with immunohistochemistry.     

A comparative study of cell proliferation markers in breast carcinomas

Aims—To investigate the tumour cell proliferative index obtained by immunostaining of paraffin wax sections of 30 cases of breast carcinoma with monoclonal antibodies MIB1, KiS1 and KiS5, and polyclonal Ki67 antisera to the Ki67 antigen and 19A2 and PC10 antibodies to proliferating cell nuclear antigen and the possible correlation between these indices and that of monoclonal Ki67 antibody in frozen sections of the same tumours.     

NPC2 expression in thyroid tumors and its possible diagnostic utility

Histopathologic diagnosis of thyroid lesions is sometimes difficult and may require the assistance of immunohistochemistry. Currently-used immunohistochemical biomarkers share the weakness of staining both papillary thyroid carcinoma and other non-papillary thyroid lesions. We examined NPC2 as an immunohistochemical marker in various thyroid lesions to determine the subcellular localization of the immunohistochemistry signal and evaluated the value of NPC2 as a diagnostic marker of papillary thyroid carcinoma. NPC2 immunostaining was performed on various thyroid tumors and tumor-like lesions. The immunostaining revealed significantly different patterns for papillary carcinomas and the other lesions. Papillary carcinomas exhibited moderate to strong granular cytoplasmic staining, often with basal membranous accentuation. In contrast, the other lesions showed mostly weak cytoplasmic staining, often with apical membranous accentuation. The subcellular localization of NPC2 provided insight into contrasting histopathologic morphology and reversed cellular polarity between the papillary patterns of papillary carcinomas and the follicular patterns of non-papillary carcinoma lesions. The diagnostic characteristics of NPC2 immunohistochemistry for non-follicular papillary carcinomas versus non-papillary carcinoma lesions were a sensitivity of 97.3%, specificity of 96.9%, positive predictive value of 94.7%, and negative predictive value of 98.4%. Significant differences were present between the two staining patterns in papillary carcinoma relative to mean age, nodal metastasis, and follicular and non-follicular variants (P = 0.02, P = 0.03, and P = 0.000, respectively). In conclusion, our evaluation of the subcellular localization of NPC2 using immunohistochemistry demonstrated possible value of NPC2 as a biomarker and provided insight into the morphologic characteristics of papillary carcinoma.     

鼻咽癌中上皮间充质改变现象观察

目的观察鼻咽癌中上皮间充质改变（EMT）现象，初步探讨上皮间充质改变在鼻咽癌侵袭转移中的作用。方法对58例鼻咽癌和29例鼻咽黏膜慢性炎免疫组化SP法检测Vimentin抗体，根据结果．Vimentin阳性病例再用相同的方法分别检测E-cadhefin、β-catenin和Snail的表达。结果58例鼻咽癌中8例边缘部位癌细胞Vimentin阳性表达，29例慢性炎上皮细胞均为阴性（P=0．037）。在8例阳性病例中，Vimentin阳性的区域癌细胞E-cadherin染色明显弱于Vimentin阴性部位，甚至呈阴性；Snail在肿瘤周边区的阳性细胞数量明显多于中央区，阳性强度也强于中央区；β-catenin在肿瘤中央区为细胞间连接部位膜阳性，周边区部分细胞，尤其是散在于间质中单个癌细胞呈现阳性表达向胞质胞核内移现象。结论鼻咽癌在侵袭和转移过程中存在EMT现象．EMT现象的发现为研究鼻咽癌转移机制提供了新的理论基础，为鼻咽癌的治疗提供了新途径。     

Expression of actin isoforms and intermediate filament proteins in childhood orbital rhabdomyosarcomas

The diagnosis of orbital rhabdomyosarcoma (RMS) in childhood gives rise to several clinical and anatomo-pathological problems. Antibodies recognizing structural proteins and cytoskeletal components have been shown to increase the diagnostic accuracy of different neoplastic lesions. In this study we examined anatomo-clinically and, where possible, by means of immunohistochemistry and electron microscopy, a series of 14 cases of orbital RMS in childhood. In the 12 cases studied by immunohistochemistry, desmin was always present, although showing variable patterns, and alpha-sarcomeric actin was found in 10 cases. alpha-Smooth muscle actin was always absent. The other markers tested (myoglobin, polyclonal actin, vimentin and enolase) proved unreliable for several reasons. We conclude that antibodies against desmin and alpha-sarcomeric actin are useful for the diagnostic definition of RMS. In addition, immunohistochemical analysis supplies data regarding the degree of tumor differentiation and may be applied to monitor radio- and chemotherapy.