Abortive transcript (AT) is a 2-19 nt long non-coding RNA that is produced in the abortive initiation stage. Abortive initiation was found to be closely related to RNA polymerase through in vitro experiments. Therefore, the distribution of AT length and the scale of abortive initiation are correlated to the promoter, discriminator, and transcription initiation sequence, and can be affected by transcription elongation factors. AT plays an important role in the occurrence and development of various diseases. Here we summarize the discovery of AT, the factors responsible for AT formation, the detection methods and biological functions of AT, to provide new clues for finding potential targets in the early diagnosis and treatment of cancers.

Tissue polypeptide antigen (TPA) and carcinoembryonic antigen (CEA) were determined in the sera of 36 control subjects, 30 patients with pancreatic cancer, 35 with chronic pancreatitis and 25 with non-pancreatic digestive disease to evaluate their role in detecting pancreatic malignancy. Abnormal values of TPA and CEA were found in 28 and 19 of 30 patients with pancreatic cancer, and in four and seven of 35 patients with chronic pancreatitis, respectively. Raised titres of TPA were observed more often than equivalent serum CEA in simulated pancreatic diseases. The receiver-operating (ROC) characteristic curves showed that TPA was more discriminating than CEA in detecting pancreatic cancer. Specificity was enhanced when both titres were abnormally high and sensitivity when one titre was raised, but the diagnostic accuracy of TPA alone has not improved, which satisfactorily discriminates pancreatic cancer from chronic pancreatitis.

Serum tissue polypeptide antigen, (TPA), carcinoembryonic antigen (CEA), calcitonin (CT) and thyroglobulin (Tg) have been measured by specific radioimmunoassays in 174 patients with various types of thyroid cancer previously submitted to thyroidectomy. Elevated serum TPA concentrations were found in 12 of 13 patients with local invasion or distant metastases from undifferentiated thyroid cancer or thyroid lymphosarcoma, while serum Tg and CEA values were normal or undetectable. In 123 patients with well differentiated thyroid cancer serum TPA was usually normal regardless of the presence or absence of functioning metastases. On the contrary, 14 of 15 patients with "dedifferentiated" metastases from previously differentiated thyroid cancer had elevated serum TPA values, while serum CEA was normal and serum Tg variable. Serum CT was confirmed as the most sensitive marker of metastatic medullary thyroid carcinoma, but elevated serum TPA values were also found in most of these cases. The present data indicate that serum TPA provides a new humoral marker in the follow-up of undifferentiated and "dedifferentiated" thyroid carcinoma and may also be usefully employed as an additional marker for medullary thyroid carcinoma.

The clinical significance of radioimmunological determination of Tissue Polypeptide Antigen (TPA) has been studied on patients with breast cancer (n = 376), on "normal subjects" (n = 92), on benign diseases of the breast as well as on patients with inflammatory diseases (n = 98). TPA levels were elevated (120 U/l or higher) in the group with inflammatory diseases in 68% and in the group with breast cancer (stage IV with progression of disease) in 85%. In all other groups (healthy controls, benign diseases of the breast, breast cancer before operation, breast cancer stage I (NED), breast cancer stage II and III (NED), and breast cancer stage IV (PR/CR), TPA was higher only in 5-22%. TPA determinations seem not to be very useful for diagnostic purposes in breast cancer, but it can be regarded as suitable for monitoring proliferative processes in advanced breast cancer. Limitations result from lack of tumor specificity of the proliferation marker TPA. So far, follow-up studies after mastectomy in breast cancer and in patients with advanced breast cancer under chemotherapy have shown that CEA and TPA are concordant. There is no cross reactivity between CEA and TPA. The main component of the labeled tracer has an isoelectric point of 4.4 but there is some impurity in the tracer as it was shown in chromatofocusing.