胃泌素释放肽受体与妇科肿瘤的诊断与治疗

胃泌素释放肽GRP(gastrin-releasing peptide,GRP)作为一种生长因子可以在许多肿瘤组织表达,GRP与肿瘤中的受体GRPR结合后,可启动一系列信号传导通路及基因调控机制,从而促进肿瘤细胞的增殖.GRPR在正常组织和肿瘤组织中的激活作用有重要的生长效应.且在恶性肿瘤中的表达比在正常的人体组织更为普遍.以GRPR作为靶向治疗已有一定的理论支持,但临床研究不多.本文着重要阐述的是关于GRPR与妇科肿瘤的诊断与治疗的关系并展望了其前景.     

The clinical effect study on malignant tumors with chronoradiotherapy

Like normal cells, tumor cells are also rhythmic. Chronochemotherapy has been proven to be effective in clinic, yet there are still some controversies about the efficacy and radiotherapy-related toxicity of chronoradiotherapy. This study was designed to investigate the therapy-related toxicity and short-term effect of four types of malignant tumor patients who were treated with radiotherapy at two different times. 121 cases of malignant tumor patients with radiotherapy indications were randomly divided into morning radiotherapy (MR) group and evening radiotherapy (ER) group, who received an identical procedure of radiotherapy at 9?am or 9 pm, respectively. The effects of radiotherapy were evaluated by short-term effect and therapy-related toxicity in this study. The efficacy rates of radiotherapy of lung cancer and nasopharyngeal carcinoma in ER groups were higher than those in MR groups, but the difference was not statistically significant (P > 0.05); the efficacy rates of radiotherapy of cervical and esophageal cancers in ER groups were significantly higher than those in MR groups (P < 0.05). The incidences of radiotherapy-related toxicity in these 4 types of malignant tumor patients were significantly lower in ER groups (P < 0.05), compared with MR groups. It suggests that irradiation in the evening could increase the efficacy in cervical and esophageal cancer patients and reduce the incidence of radiotherapy-related toxicity in these four malignant tumor patients.     

The diagnostic value of RNA oncomarkers in evaluation of malignant breast tumors

The levels of the RNA oncomarkers, telomerase (hTERT), cytokeratin-19 (CK-19), and mammaglobin (MAM) have been investigated in capillary blood of female patients with mammary ductal carcinoma. The study revealed overexpression of all three factors in patients with this pathology. This overexpression was not found in healthy donors and female patients with mammary fibroadenoma. Levels of the RNA oncomarkers return to the normal level within 10 days after successful tumor resection. These results have been used for the development of diagnostic kits, which may be applicable for differential diagnostics, screening and postoperation monitoring of patients with malignant breast tumors.     

Hemostatic mechanisms and malignant tumors

The mutual relationships between malignant tumours and mechanisms of blood coagulation are presented in a brief survey. In this connection, the mechanisms of a tumour cell entering the circulation through the vessel well and its leaving into the tissues are discussed, the theory of microtrauma being used for explaining these processes. Subsequently, the alterations to be found in the count and function of thrombocytes after contact with a malignant cell and the impact on this cell by blood platelets are represented. As a third factor the activation of blood coagulation which is exercised by substances with a procoagulatory effect produced by the malignant tissue and the frequently observed thrombosis in the course of neoplastic diseases are dealt with in connection with blood level changes of some coagulation factors. In a fourth section the significance of fibrinolysis, its activation and inhibition as well as the production of fibrinolytic activators by neoplasms are discussed.     

Diversification and progression of malignant tumors

Tumor-cell diversification mechanisms insure that malignant neoplasms contain diversified tumor-cell subpopulations. Because of the instability of tumor cell phenotypes, some malignant cells will evolve with the most favorable properties for their progression to highly metastatic cells. The rates of cellular phenotypic diversification vary greatly among different tumors, and they are probably modulated, in part, by genetic and chromosome defects and by epigenetic events that may vary widely depending upon the nature of the tumor cells and their microenvironments. As tumor diversification and selection proceed, the most malignant cell subpopulations may eventually become dominant and gradually lose their microenvironmental responsiveness. Tumor-cell diversification mechanisms may be similar or identical to normal, developmentally regulated diversification mechanisms that are used during embryonic cell diversification and differentiation.     

Chromosome changes and human malignant tumors

The data from home and foreign literature on chromosome changes in human tumours of different genesis and localization are analyzed. The role and significance of changes in the chromosome structure in malignant cells are discussed.     

Superoxide dismutases in malignant cells and human tumors

Reactive oxygen metabolites have multifactorial effects on the regulation of cell growth and the capacity of malignant cells to invade. Overexpression of the superoxide dismutases (SODs) in vitro increases cell differentiation, decreases cell growth and proliferation, and can reverse a malignant phenotype to a nonmalignant one. The situation in vivo is more complex due to multiple interactions of tumor cells with their environment. Numerous in vivo studies show that the superoxide dismutases can be highly expressed in aggressive human solid tumors. Furthermore, high SOD has occasionally been associated with a poor prognosis and with resistance to cytotoxic drugs and radiation. Most of the apparent conflicts between the above in vitro and in vivo observations can be reconciled by considering the net redox status of tumor cells in different environments. Administering high concentrations of SOD to cells in vitro is usually associated with a non- or less malignant phenotype, whereas secondary induction of SOD in tumors in vivo can be associated with an aggressive malignant transformation probably due to the altered (oxidative) redox state in the malignant cells. This concept suggests that for many types of tumors antioxidants could be used to diminish the invasive capability of malignant cells.