The Effects Of Angiotensin-Ⅱ And Angiotensin-Ⅱ Type 1 Receptor Antagonist-Telmisartan On The Occurrence And Development Of Esophageal Squamous Cell Carcinoma

Esophageal carcinoma is one of the most common malignant neoplasms in China. Early esophageal carcinomas are often ignored due to absent symptoms. When the apparent symptoms appear, esophageal carcinomas often have developed to the late stage. Therefore, it is crucial to prevent and control the occurrence and development of esophageal carcinoma. Increasing studies have shown that many hormones are closely associated with the occurrence and development of carcinomas. Angiotensin- â…¡ (ANG- â…¡), a polypeptidic hormone, is the main effector in the renin-angiotensin system (RAS). Recently, activation of the local RAS was shown in certain tumor tissues, which resulted in the production of local ANG- â…¡. There are two major subtypes of ANG-â…¡ receptors, termed ANG-â…¡ type 1 receptor (AT₁R) and ANG-â…¡ type 2 receptor (AT2R) in human. It has been found that the expression of AT₁R was dramatically up-regulated in some malignant neoplasms, such as ovarian cancer, breast cancer, hepatic cancer, renal cancer, and so on. It is supposed that AT₁R might be involved in the occurrence and development of those carcinomas.Sartans are a kind of highly selective AT₁R antagonists, which can selectively block the effects of ANG- â…¡ mediated by AT₁R. It has been shown that candesartan strongly reduced the size and vascularization of syngeneic sarcomas and reduced the number of lung metastases of 3LL carcinoma cells in mice. Losartan also inhibited the production of several important vascular growth factors, including vascular endothelial growth factor (VEGF) and angiopoietin-2(Ang-2), and reduced the microvessel density(MVD) in tumors and delayed rat C6 glioma cell growth in vitro and in vivo. These results suggest that blockade of the AT₁R could be an effective...