| Background Chordoma is a kind of low malignant,primarily bone tumor,and it arises from residue of the notochord.Chordoma mostly locates in the axis with nearly 50%in the sacrum,35%in the clivus.Chordoma has the character of biological behavior with slowly,infiltrating progression,and metastasis to lung in late cases. Conditions that occurs with spinal chordoma such as osteolysis of bone,collapse of vertebrae,instability of spine column and compression of spinal cord often lead to severe pain,neurofunctional impairment even plegia,then result in decrease of life quality of patients.Surgical treatment takes an irreplaceable role in the treatment of spinal chordoma with removing of lesions,decompression of cord,and reconstruction of spine.Because the complicated anatomic structure of the spine,tumors likely to be around by some vital nerv vasorum structure,which lead to the difficulty in the total excising the tumors.Also due to not sensitive to most radiotherapy and chemotherapy, chordoma has a high level of local recurrence rate and a poor prognosis after surgical treatments,even surgical treatment combined with radiotherapy and chemotherapy is adopted in clinical treatments.Patients may dead of the tumor with the recurrence again and again.According to some statistics report,patients with chordoma have a total mortality of 63%with survival rate of 50%in 5 years and 28%in 10 years. Reliable prediction is the key to determine suitable strategy for spinal chordomas. Because the total disease incidence is not high relatively,there are few study data reported of factors which affecting the prognosis of spinal chordoma.With the development of molecular biology,rapid progress was achieved in research of tumor-related genes.Many studies indicated close relationship between prognosis of tumor and mutation or abnormal expression of gene.Molecular biomarkers with prognostic value were identified in research of primary tumors such as breast cancer,lung cancer and liver cancer,and some of them even became new therapy target in subsequent research,while studies on chordoma were seldom and report about the correlation between the genes and tumors for the spinal chordoma is rare.The genesis and progression of tumor is regarded as a complicated course that multiple gene and multiple factor participates the process.Large sample and multiple genes research are needed to screen prognostic genes.Repetitive operation on multiple samples,large workload,long time and high costs were spent during a traditional method and the result could be affected by different experiment condition. The innovation of tissue chip provides a powerful tool with which high-throughput, large sample and rapid analyses on thousands of natural or pathologic tissue samples in three levels including gene,genetic transcription and biological function of expression product can be put into reality.It has been proved in many studies that tissue microarray is a reliable and stable method with the advantage of saving tissue and equal experiment condition.The value of tissue microarray technology in large sample and multiple gene analyses of prognostic research is enormous and it has been used in many studies on tumors.Cadherins and catenins play an important role in the course of adherence of cell to cell.Much research have indicate that the expression of the proteins as mentioned has a direct relationship to the invasiveness and metastasis of the tumors.As a new family member of the catenins,P120ctn became the key-point of research about molecule mechanism of tumors.But the expression and the correlating significance in chordomas had not been reported in the native or foreign literatures.Objective To construct tissue chip of spinal chordoma with normal fetal notochord as control,and detect the expression of E-cadherin and the catenins family members thatα-catenin,β-catenin,γ-catenin,P120-catenin in the tissue array of chordoma,then to detect the correlation of the exppresion of proteins and the recurrence of this tumor with the clinical and pathological data combination by statistic analyses.Methods A total of 40 cases of spinal chordoma underwent surgical treatment in Changzheng Hospital and the first affiliated hospital of WenZhou medical university from Jan.1997 to Jan.2007 with complete clinical and follow up data,as well as five specimens of normal fetal notochord ranged from 9 weeks to 25 weeks was included in this study A 9-row and 10-column tissue microarray consisting of 90 samples with 1.0mm diameter was built by a tissue microarrayer.Tissue chips of spinal chordoma were obtained from serial sections of tissue microarray.The expression of E-cad and catenins were detected on the tissue chips by immunohistochemistry to detect the abnormal expression of the proteins.The SPSS statistical software was used in analyses on different exppresion between chordoma tissue and normal notochord,relationship between each gene expression and biological behavior of spinal chordomas.The significance of different gene expression and clinical data,which correlates to prognosis of patients was determined by Kaplan Meier survival analyses and Log-Rank test.Cox model multivariate analyses were used to detect the correlation factors about tumor recurrence.Results 1.The tissue microarray built in this study is integrated well with a high availability of 97.3%,and 50 tissue chips were produced from it.2.For the five specimens of normal fetal notochord,the expression of proteins mainly appeared on the point of cell-cell conjunction,means cytomembrane,and no stain could be detected on the nucleus.For the 40 specimens of spinal chordoma,the spare or total loss of expression is the majority.Significance correlation were found in P120ctn and E-cad when comparing the result of chordomas with that of notochord(P＜0.05). Some of the specimens of chordoma presented with the manifest of"transposition into nucleus",including 14 specimens ofα-catenin,2 specimens ofβ-catenin,13 specimens ofγ-catenin,9 specimens of P120ctn,and 4 specimens of E-cad.3.Based on the result of statistics,there is significance correlation between abnormal expression of proteins,such asα-catenin andγ-catenin,E-cadherin and P120-catenin. 4.Mono-factor analysis revealed that significance difference occurred between factors,such asα-catenin and age,γ-catenin and pathological grading, P120-catenin and pathological grading,E-cadherin and vertebral quantity.The result of Logisitic Statistics revealed that the abnormal expression rate ofβ-catenin in females is higher than it in males,KPS score is the protect factor for the abnormal expression ofβ-catenin,age is the risk factor of the abnormal expression ofα-catenin,pathological grading is the risk factor of the abnormal expression of both r-catenin and P120-catenin.5.Kaplan-Meier analysis and Log Rank check revealed that significance difference occurred among factors about mean free survival time of patients,such as different expression ofγ-catenin,P120- catenin,E-cadherin and different levels of pathological grading.While,significance difference occurred among the different level of factors about total survival time of patients,such as P120-catenin and E-cadherin.COX model analysis revealed that P120-catenin and pathological grading were the independent pretest factors of the recurrence of the spinal chordoma.Conclusion 1.The applying of the technique of tissue microarray in the study of spinal chordoma was well preserved and stable.2.In the process of carcinogenesis and progression of spinal chordomas,abnormal expression of E-cadherin,α-catenin,β-catenin,γ-catenin,P120- catenin occurred in different degrees.Significance occurred between the abnormal expression ofγ-catenin and pathological grading,the abnormal expression of P120-catenin and pathological grading,and different level of pathological grading and vertebral quantity of involvement,which revealed that these factors may be correlating to the enhancement of dedifferentiation and invasiveness of spinal chordoma.3.Significant correlation occurred between the different levels ofγ-catenin,P120-catenin,E—cadherin and pathological grading and recurrence of the spinal chordoma,as well as between the different levels of E—cadherin,P120-catenin and survival time of patients.So these factors may be regarded as useful index in detecting the prognosis of spinal chordoma. P120-catenin and pathological grading were the independent pretest factors of the prognosis in spinal chordoma. |
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